Lock-up control system for lock-up type automatic transmission

Claim 2

A lock-up type automatic transmission for use with an engine in an automotive vehicle, said lock-up type automatic transmission being shiftable between a plurality of gear ratios including a first gear ratio, a second gear ratio and a third gear ratio and comprising: a torque converter having a pump impeller adapted to be driven by said engine and a turbine runner; a lock-up clutch having a clutch piston drivingly connected to said turbine runner, said lock-up clutch being selectively engageable with said pump impeller; gear ratio determining means operatively connected to said lock-up type automatic transmission for determining which of said plurality of gear ratios said lock-up type automatic transmission is operating in and generating a corresponding gear ratio indicative signal; vehicle speed sensor means for detecting a vehicle speed of the automotive vehicle and generating a vehicle speed indicative signal; means, coupled to said gear ratio determining means and to said vehicle speed sensor means, for generating a lock-up signal according to a predetermined pattern, wherein said lock-up signal is generated when said vehicle speed indicative signal is higher than a predetermined first lock-up vehicle speed value under a condition wherein a first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined second lock-up vehicle speed value under a condition wherein a second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined third lock-up vehicle speed value under a condition wherein a third gear ratio indicative signal is present; control means, coupled to said generating means, for engaging said lock-up clutch in response to said lock-up signal; temperature sensor means operatively connected to said engine for detecting a temperature of said engine and for generating a low temperature signal when the temperature of said engine is lower than a predetermined temperature value; means responsive to said low temperature signal for preventing said lock-up signal from being coupled to said control means in said predetermined pattern.

Claim 3

The lock-up type automatic transmission of claim 1, wherein said preventing means includes means responsive to said low temperature signal for increasing each of said predetermined first, second and third lock-up vehicle speed values.

Claim 4

The lock-up type automatic transmission of claim 1, further including means for detecting a load on said engine and generating a load indicative signal, wherein said preventing means includes means responsive to said low temperature signal and said load indicative signal for increasing said predetermined first, second and third lock-up vehicle speed values.

Claim 5

The lock-up type automatic transmission of claim 1, further including means for detecting a load on said engine and generating a load indicative signal and wherein said preventing means includes means responsive to said load indicative signal for increasing said predetermined first, second and third lock-up vehicle speed values, said preventing means further comprising means for preventing transmission of said lock-up signal to said control means, thereby preventing engagement of said lock-up clutch when said low temperature signal is present.

Claim 6

The lock-up type automatic transmission of claim 1, wherein said preventing means includes means responsive to said low temperature signal for preventing transmission of said lock-up signal to said control means, thereby preventing engagement of said lock-up clutch when said low temperature signal is present.

Claim 7

The lock-up type automatic transmission of claim 1, further comprising means for detecting when said automatic transmission is shifting between any of said plurality of gears and for generating a gear shift signal of predetermined duration whenever gear shifting is detected, and a gate means responsive to said gear shift signal to prevent said lock-up signal from being transmitted to said control means whenever said gear shift signal is present.

Claim 8

A lock-up type automatic transmission for use with an engine, said lock-up automatic transmission being shiftable between a plurality of gear ratios including a first gear ratio, a second gear ratio and a third gear ratio and comprising: a torque converter having a pump impeller adapted to be driven by said engine and a turbine runner; a lock-up clutch having a clutch piston drivingly connected to said turbine runner and being selectively engageable with said pump impeller; gear ratio determining means operatively connected with said lock-up type automatic transmission for determining which of said plurality of gear ratios said lock-up type automatic transmission is in and generating a corresponding gear ratio indicative signal; vehicle speed sensor means for detecting a vehicle speed of the automotive vehicle and generating a vehicle speed indicative signal; first comparator and gate means coupled to said gear ratio determining means and said vehicle speed sensor means for generating a lock-up signal when said vehicle speed indicative signal is higher than a predetermined relatively high first lock-up vehicle speed value under a condition wherein a first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively high second lock-up vehicle speed value under a condition wherein a second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively high third lock-up vehicle speed value under a condition wherein a third gear ratio indicative signal is present; second comparator and gate means coupled with said gear ratio determining means and said vehicle speed sensor means for generating a lock-up signal when said vehicle speed indicative signal is higher than a predetermined relatively low first lock-up vehicle speed value under a condition wherein said first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively low second lock-up vehicle speed value under a condition wherein said second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively low third lock-up vehicle speed value under a condition wherein said third gear ratio indicative signal is present, each of said predetermined relatively high lock-up vehicle speed values being higher than a corresponding predetermined relatively low lock-up vehicle speed value; selector means for detecting an operating condition of said engine and selectively disabling one of said first or second comparator and gate means in response to said detected condition; control means, coupled to said first and second comparator and gate means for engaging said lock-up clutch in response to said lock-up signal.

Claim 9

A lock-up type automatic transmission for use with an engine, said lock-up automatic transmission being shiftable between a plurality of gear ratios including a first gear ratio, a second gear ratio and a third gear ratio and comprising: a torque converter having a pump impeller adapted to be driven by said engine and a turbine runner; a lock-up clutch having a clutch piston drivingly connected to said turbine runner and being selectively engageable with said pump impeller; gear ratio determining means operatively connected with said lock-up type automatic transmission for determining which of said plurality of gear ratios said lock-up type automatic transmission is in and generating a corresponding gear ratio indicative signal; vehicle speed sensor means for detecting a vehicle speed of the automotive vehicle and generating a vehicle speed indicative signal; first comparator and gate means coupled to said gear ratio determining means and said vehicle speed sensor means for generating a lock-up signal when said vehicle speed indicative signal is higher than a predetermined relatively high first lock-up vehicle speed value under a condition wherein a first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively high second lock-up vehicle speed value under a condition wherein a second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively high third lock-up vehicle speed value under a condition wherein a third gear ratio indicative signal is present; second comparator and gate means coupled with said gear ratio determining means and said vehicle speed sensor means for generating a lock-up signal when said vehicle speed indicative signal is higher than a predetermined relatively low first lock-up vehicle speed value under a condition wherein said first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively low second lock-up vehicle speed value under a condition wherein said second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined relatively low third lock-up vehicle speed value under a condition wherein said third gear ratio indicative signal is present, each of said predetermined relatively high lock-up vehicle speed values being higher than a corresponding predetermined relatively low lock-up vehicle speed value; selector means for detecting an operating condition of said engine and selectively disabling one of said first or second comparator and gate means in response to said detected condition; control means, coupled to said first and second comparator and gate means for engaging said lock-up clutch in response to said lock-up signal.

Claim 10

The lock-up type automatic transmission of claim 1, wherein said selector means includes a temperature sensor means for detecting a temperature of said engine and generating a low temperature signal when the engine temperature is lower than a predetermined temperature value, said selector means being operable to disable said second comparator and gate means in response to the presence of said low temperature signal.

Claim 11

The lock-up type automatic transmission of claim 1, wherein said selector means further includes load sensor means for detecting a load on said engine and generating a load indicative signal when the engine load is lower than a predetermined value, said selector means being operable to disable said second comparator and gate means in response to the absence of said load indicative signal.

Claim 12

The lock-up type automatic transmission of claim 1, further including temperature sensor means for detecting a temperature of said engine and generating a low temperature signal when the engine temperature is lower than a predetermined temperature value and means for preventing transmission of said lock-up signal to said control means in response to the presence of said low temperature signal.

Claim 13

The lock-up type automatic transmission of claim 7, further comprising means for detecting when said automatic transmission is shifting between any of said plurality of gears and for generating a gear shift signal of predetermined duration whenever gear shifting is detected, and a gate means responsive to said gear shift signal to prevent said lock-up signal from being transmitted to said control means whenever said gear shift signal is present.

Claim 14

In an automotive vehicle: an engine; a lock-up type automatic transmission shiftable between a plurality of gear ratios including a first gear ratio, a second gear ratio and a third gear ratio and including a torque converter having a pump impeller driven by said engine and a turbine runner; a lock-up clutch having a clutch piston drivingly connected to said turbine runner and being selectively engageable with said pump impeller; a gear ratio determining means operatively connected to said lock-up type automatic transmission for determining which of said plurality of gear ratios said lock-up type automatic transmission is in and generating a corresponding gear ratio indicative signal; vehicle speed sensor means for detecting a vehicle speed of the automotive vehicle and generating a vehicle speed indicative signal; comparator and gate means coupled to said gear ratio determining means and said vehicle speed sensor means for generating a lock-up signal when said vehicle speed indicative signal is higher than a predetermined first lock-up vehicle speed value under a condition wherein a first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined second lock-up vehicle speed value under a condition wherein a second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined third lock-up vehicle speed value under a condition wherein a third gear ratio indicative signal is present; control means, coupled to said comparator and gate means, for engaging said lock-up clutch in response to said lock-up signal; means for detecting a temperature of said engine and generating a temperature indicative signal; means for preventing the transmission of said lock-up signal to said control means in response to said temperature indicative signal.

Claim 15

In an automotive vehicle: an engine; a lock-up type automatic transmission shiftable between a plurality of gear ratios including a first gear ratio, a second gear ratio and a third gear ratio and including a torque converter having a pump impeller driven by said engine and a turbine runner; a lock-up clutch having a clutch piston drivingly connected to said turbine runner and being selectively engageable with said pump impeller; a gear ratio determining means operatively connected to said lock-up type automatic transmission for determining which of said plurality of gear ratios said lock-up type automatic transmission is in and generating a corresponding gear ratio indicative signal; vehicle speed sensor means for detecting a vehicle speed of the automotive vehicle and generating a vehicle speed indicative signal; comparator and gate means coupled to said gear ratio determining means and said vehicle speed sensor means for generating a lock-up signal when said vehicle speed indicative signal is higher than a predetermined first lock-up vehicle speed value under a condition wherein a first gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined second lock-up vehicle speed value under a condition wherein a second gear ratio indicative signal is present or when said vehicle speed indicative signal is higher than a predetermined third lock-up vehicle speed value under a condition wherein a third gear ratio indicative signal is present; control means, coupled to said comparator and gate means, for engaging said lock-up clutch in response to said lock-up signal; means for detecting a temperature of said engine and generating a temperature indicative signal; means for preventing the transmission of said lock-up signal to said control means in response to said temperature indicative signal.

Claim 16

The lock-up type automatic transmission of claim 12, further comprising means for detecting when said automatic transmission is shifting between any of said plurality of gears and for generating a gear shift signal of predetermined duration whenever gear shifting is detected, and a gate means responsive to said gear shift signal to prevent said lock-up signal from being transmitted to said control means whenever said gear shift signal is present.