Engine cooling system providing mixed or unmixed head and block cooling

Claim 1

For an internal combustion engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system, comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve.

Claim 40

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve, when said cooling system is filled with cooling fluid, comprising the processes, simultaneously performed, of: (n) operating said first pump and said second pump; and (o) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (p) and (q): (p) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (p1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (p2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid through said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (q) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then simultaneously: (q1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow cooling fluid to flow through said radiator; and (q2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket.

Claim 41

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve, when said cooling system is filled with cooling fluid, comprising the processes, simultaneously performed, of: (n) operating said first pump and said second pump; and (o) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (p) and (q): (p) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (p1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (p2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid through said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (q) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then simultaneously: (q1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow cooling fluid to flow through said radiator; and (q2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket.

Claim 48

A method for operating according to any one of claims 39, 43, 44, or 46, wherein during process (q) the opening amount of said second valve is controlled, by said block flow regulation signal, as to allow such an amount of cooling fluid to flow from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket, as to keep the sensed block output temperature signal produced by said block output fluid temperature sensor approximately at a level indicative of a second predetermined temperature.

Claim 53

A method for operating according to either one of claims 39 and 50, said cooling system further comprising a block input fluid temperature sensor for sensing the temperature of the cooling fluid which enters into said cylinder block inlet of said block cooling jacket, and for generating a sensed block input temperature signal representative of said temperature, said sensed block input temperature signal being supplied to said controller, wherein during process (q) the delivery rate of said second pump is so controlled as to keep the difference between the cooling fluid temperature indicated by said sensed block output temperature signal and the cooling fluid temperature indicated by said sensed block input temperature signal within a certain second range of a certain second predetermined temperature difference.

Claim 56

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve and a head output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder head outlet of said head cooling jacket, and for generating a sensed head output temperature signal representative of said temperature, said sensed head output temperature signal being supplied to said controller, when said cooling system is filled with cooling fluid, comprising the processes, simultaneously performed, of: (n) operating said first pump and said second pump; and (o) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (p) and (q); (p) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (p1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (p2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid through said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (q) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then simultaneously: (q1) selectively controlling said first control valve, by said radiator flow regulation signal from said controller, according to said sensed head output temperature signal received from said head output fluid temperature sensor by said controller, so as selectively to allow cooling fluid to flow through said radiator in such a way as to maintain the temperature indicated by said sensed head output temperature signal substantially at a third predetermined temperature value; and (q2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket.

Claim 57

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve and a head output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder head outlet of said head cooling jacket, and for generating a sensed head output temperature signal representative of said temperature, said sensed head output temperature signal being supplied to said controller, when said cooling system is filled with cooling fluid, comprising the processes, simultaneously performed, of: (n) operating said first pump and said second pump; and (o) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (p) and (q); (p) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (p1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (p2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid through said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (q) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then simultaneously: (q1) selectively controlling said first control valve, by said radiator flow regulation signal from said controller, according to said sensed head output temperature signal received from said head output fluid temperature sensor by said controller, so as selectively to allow cooling fluid to flow through said radiator in such a way as to maintain the temperature indicated by said sensed head output temperature signal substantially at a third predetermined temperature value; and (q2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket.

Claim 58

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve and a head output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder head outlet of said head cooling jacket, and for generating a sensed head output temperature signal representative of said temperature, said sensed head output temperature signal being supplied to said controller, when said cooling system is filled with cooling fluid, comprising the processes simultaneously performed, of: (n) operating said first pump and said second pump; and (o) if said sensed head output temperature signal from said head output fluid temperature sensor indicates a cooling fluid temperature at said cylinder head outlet of said head cooling jacket of less than a certain fourth predetermined temperature value, then simultaneously: (o1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (o2) controlling said second control valve, by said block flow regulation signal, so as substantially to interrupt flow of cooling fluid through said radiator bypass conduit system from said main recirculation conduit system to said cylinder block inlet of said block cooling jacket.

Claim 59

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve and a head output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder head outlet of said head cooling jacket, and for generating a sensed head output temperature signal representative of said temperature, said sensed head output temperature signal being supplied to said controller, when said cooling system is filled with cooling fluid, comprising the processes simultaneously performed, of: (n) operating said first pump and said second pump; and (o) if said sensed head output temperature signal from said head output fluid temperature sensor indicates a cooling fluid temperature at said cylinder head outlet of said head cooling jacket of less than a certain fourth predetermined temperature value, then simultaneously: (o1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (o2) controlling said second control valve, by said block flow regulation signal, so as substantially to interrupt flow of cooling fluid through said radiator bypass conduit system from said main recirculation conduit system to said cylinder block inlet of said block cooling jacket.

Claim 61

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve, (n) an engine rotational speed sensor for detecting the rotational speed of a component of said internal combustion engine and for producing an engine rotational speed sensor signal representative thereof, said engine rotational speed sensor signal being supplied to said controller, and (o) an engine load sensor for detecting the load on said internal combustion engine and for producing an engine load sensor signal representative thereof, said engine load sensor signal being supplied to said controller, said cooling system further comprising a head output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder head outlet of said head cooling jacket, and for generating a sensed head output temperature signal representative of said temperature and feeding said sensed head output temperature signal to said controller, said cooling system being filled with cooling fluid, comprising the processes, simultaneously performed, of: (p) operating said first pump and said second pump; and (q) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (r) and (s): (r) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (r1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (r2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid thorugh said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (s) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then: (s1) if said engine rotational speed sensor is producing an engine rotational speed sensor signal representative of high engine rotational speed and at the same time said engine load sensor is producing an engine load sensor signal indicative of high engine load, then simultaneously: (t1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow cooling fluid to flow through said radiator in the maximum amount; and (t2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket; (s2) and if said engine load sensor is producing an engine load sensor signal which is not indicative of high engine load, then simultaneously: (u1) selectively controlling said first control valve, by said radiator flow regulation signal from said controller, according to said sensed head output temperature signal, so as selectively to allow cooling fluid to flow through said radiator in an amount which is appropriate to maintain the temperature indicated by said sensed head output temperature signal from said head output fluid temperature sensor at approximately a sixth predetermined temperature; and (u2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket.

Claim 62

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve, (n) an engine rotational speed sensor for detecting the rotational speed of a component of said internal combustion engine and for producing an engine rotational speed sensor signal representative thereof, said engine rotational speed sensor signal being supplied to said controller, and (o) an engine load sensor for detecting the load on said internal combustion engine and for producing an engine load sensor signal representative thereof, said engine load sensor signal being supplied to said controller, said cooling system further comprising a head output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder head outlet of said head cooling jacket, and for generating a sensed head output temperature signal representative of said temperature and feeding said sensed head output temperature signal to said controller, said cooling system being filled with cooling fluid, comprising the processes, simultaneously performed, of: (p) operating said first pump and said second pump; and (q) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (r) and (s): (r) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (r1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (r2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid thorugh said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (s) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then: (s1) if said engine rotational speed sensor is producing an engine rotational speed sensor signal representative of high engine rotational speed and at the same time said engine load sensor is producing an engine load sensor signal indicative of high engine load, then simultaneously: (t1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow cooling fluid to flow through said radiator in the maximum amount; and (t2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket; (s2) and if said engine load sensor is producing an engine load sensor signal which is not indicative of high engine load, then simultaneously: (u1) selectively controlling said first control valve, by said radiator flow regulation signal from said controller, according to said sensed head output temperature signal, so as selectively to allow cooling fluid to flow through said radiator in an amount which is appropriate to maintain the temperature indicated by said sensed head output temperature signal from said head output fluid temperature sensor at approximately a sixth predetermined temperature; and (u2) controlling said second control valve, by said block flow regulation signal, so as to allow a controlled flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket.

Claim 64

A method for operating according to either one of claims 57 and 58, said cooling system further comprising an engine rotational speed sensor for detecting the rotational speed of a component of said internal combustion engine and for producing an engine rotational speed sensor signal representative thereof, said engine rotational speed sensor signal being supplied to said controller, further comprising the process, performed simultaneously with process (q), of controlling the delivery rate of said second pump, according to said engine load sensor signal, said engine rotational speed sensor signal, and said sensed block output temperature signal, so as to keep the difference between the cooling fluid temperature at said cylinder block outlet of said block cooling jacket and the cooling fluid temperature at said cylinder block inlet of said block cooling jacket below a certain second limit temperature difference.

Claim 65

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve, and an engine lubricating oil temperature sensor for detecting the temperature of lubricating oil contained within said cylinder block, and for producing a lubricating oil temperature signal representative thereof, said lubricating oil temperature signal being supplied to said controller, when said cooling system is filled with cooling fluid, comprising the processes, simultaneously performed, of: (n) operating said first pump and said second pump; and (o) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (p) and (q); (p) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (p1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (p2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid through said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (q) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then, depending upon said lubricating oil temperature signal from said engine lubricating oil temperature sensor, performing either one or the other but not both of the following two processes (q1) and (q2): (q1) if said lubricating oil temperature signal from said engine lubricating oil temperature sensor indicates an engine lubricating oil temperature of less than a second predetermined temperature value, then simultaneously: (r1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow such a flow of cooling fluid through said radiator as to keep the temperature indicated by said sensed block output temperature signal from said block output fluid temperature snesor substantially at said first predetermined temperature value; and (r2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid from a downstream part of said radiator bypass conduit system and from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket; (q2) if said lubricating oil temperature signal from said engine lubricating oil temperature sensor indicates an engine lubricating oil temperature of greater than said second predetermined temperature value, then simultaneously: (s1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow cooling fluid to flow through said radiator in substantially the maximum amount; and (s2) controlling said second control valve, by said block flow regulation system, so as to allow such a controlled amount of flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket, as to keep said temperature value indicated by said lubricating oil temperature signal from said engine lubricating oil temperature sensor at substantially a third predetermined temperature value which is substantially higher than said second temperature value.

Claim 66

A method for operating a cooling system for an internal combustion engine, said engine comprising: (a) a cylinder head formed with a head cooling jacket for cooling said cylinder head, said head cooling jacket being formed with a cylinder head inlet and a cylinder head outlet; (b) a cylinder block formed with a block cooling jacket for cooling said cylinder block, said block cooling jacket being formed with a cylinder block inlet and a cylinder block outlet; and (c) a radiator formed with an inlet and an outlet; a cooling system comprising: (d) a first pump for impelling cooling fluid through said head cooling jacket from said cylinder head inlet towards said cylinder head outlet; (e) a second pump for impelling cooling fluid through said block cooling jacket from said cylinder block inlet towards said cylinder block outlet; (f) a block output fluid temperature sensor for sensing the temperature of the cooling fluid which passes out through said cylinder block outlet of said block cooling jacket, and for generating a sensed block output temperature signal representative of said temperature; (g) a block recirculation conduit system of relatively high flow resistance, leading from said cylinder block outlet of said block cooling jacket so as to supply flow of cooling fluid to said cylinder block inlet thereof; (h) a main recirculation conduit system, an upstream part of which is communicated both to said cylinder head outlet of said head cooling jacket and also to said cylinder block outlet of said block cooling jacket, and a downstream part of which is communicated to said inlet of said radiator; (i) a radiator output conduit system, leading from said outlet of said radiator both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket; (j) a first control valve for controlling flow of cooling fluid through said radiator according to a radiator flow regulation signal; (k) a radiator bypass conduit system, of relatively high flow resistance, which leads from a downstream part of said main recirculation conduit system both to said cylinder head inlet of said head cooling jacket and also to said cylinder block inlet of said block cooling jacket, operation of said first control valve so as to cut off said flow of cooling fluid through said radiator not cutting off flow of cooling fluid through said radiator bypass conduit system; (l) a second control valve for controlling flow of cooling fluid from said radiator output conduit system and said radiator bypass conduit system to said cylinder block inlet of said block cooling jacket according to a block flow regulation signal; and (m) a controller, which receives said sensed block output temperature signal from said block output fluid temperature sensor, and which produces, based thereon, said radiator flow regulation signal which is sent to said first control valve, and also said block flow regulation signal which is sent to said second control valve, and an engine lubricating oil temperature sensor for detecting the temperature of lubricating oil contained within said cylinder block, and for producing a lubricating oil temperature signal representative thereof, said lubricating oil temperature signal being supplied to said controller, when said cooling system is filled with cooling fluid, comprising the processes, simultaneously performed, of: (n) operating said first pump and said second pump; and (o) depending upon said sensed block output temperature signal from said block output fluid temperature sensor, performing either one or the other but not both of the following two processes (p) and (q); (p) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of less than a certain first predetermined temperature value, then simultaneously: (p1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as substantially to interrupt flow of cooling fluid through said radiator; and (p2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid through said radiator bypass conduit system from a downstream part of said main recirculation conduit system to said cylinder block inlet of said block cooling jacket; (q) if said sensed block output temperature signal from said block output fluid temperature sensor indicates a cooling fluid temperature at said cylinder block outlet of said block cooling jacket of greater than said first predetermined temperature value, then, depending upon said lubricating oil temperature signal from said engine lubricating oil temperature sensor, performing either one or the other but not both of the following two processes (q1) and (q2): (q1) if said lubricating oil temperature signal from said engine lubricating oil temperature sensor indicates an engine lubricating oil temperature of less than a second predetermined temperature value, then simultaneously: (r1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow such a flow of cooling fluid through said radiator as to keep the temperature indicated by said sensed block output temperature signal from said block output fluid temperature snesor substantially at said first predetermined temperature value; and (r2) controlling said second control valve, by said block flow regulation signal, so as to allow a flow of cooling fluid from a downstream part of said radiator bypass conduit system and from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket; (q2) if said lubricating oil temperature signal from said engine lubricating oil temperature sensor indicates an engine lubricating oil temperature of greater than said second predetermined temperature value, then simultaneously: (s1) controlling said first control valve, by said radiator flow regulation signal from said controller, so as to allow cooling fluid to flow through said radiator in substantially the maximum amount; and (s2) controlling said second control valve, by said block flow regulation system, so as to allow such a controlled amount of flow of cooling fluid from said radiator and said radiator output conduit system to said cylinder block inlet of said block cooling jacket, as to keep said temperature value indicated by said lubricating oil temperature signal from said engine lubricating oil temperature sensor at substantially a third predetermined temperature value which is substantially higher than said second temperature value.