Device for regulating the rate of flow of recycled exhaust gases in an internal combustion engine

Claim 2

An internal combustion engine provided with an intake duct, an exhaust duct and an auxiliary piping connected to said exhaust duct to draw a portion of the gases flowing therethrough to discharge them into said intake duct, the improvement including first means sensitive to a pressure drop undergone by the gases which flow through at least a portion of the exhaust duct, second means operably related to the first means and sensitive to a predetermined pressure drop undergone by the gases when flowing through a portion of said auxiliary piping and a member for throttling in a variable manner said auxiliary piping, said member being driven by said first and said second means in the sense of keeping proportional the respectively sensed pressure drops.

Claim 3

The internal combustion engine according to claim 1, in which said first means are sensitive to the gas pressure in a point of the exhaust duct which is downstream of the connection of the auxiliary piping to said duct, and are sensitive, to the gas pressure at a point of said auxiliary piping which is upstream of said member, and drive said member to throttle said auxiliary piping so as to maintain the sensed pressure proportional to each other.

Claim 4

An internal combustion engine provided with an intake duct, an exhaust duct and an auxiliary piping connected to said exhaust duct to draw a portion of the gases flowing therethrough to discharge them into said intake duct, the improvement including first means sensitive to a pressure drop undergone by the gases which flow through at least a portion of the exhaust duct, second means operably related to the first means and sensitive to a predetermined pressure drop undergone by the gases when flowing through a portion of said auxiliary piping and a member for throttling in a variable manner the auxiliary piping, said member being driven by said first and said second means in the sense of keeping proportional the respectively sensed pressure drops, said first means being sensitive to the gas pressure in a point of the exhaust duct which is downstream of the connection of the auxiliary piping to said exhaust duct and sensitive to the gas pressure at a point of said auxiliary piping which is upstream of said member, and drive said member to throttle said auxiliary piping so as to maintain the sensed pressure proportional to each other, said first means consisting of a deformable diaphragm for separating two chambers, the first chamber being maintained in communication with a point of said exhaust duct which is downstream of the connection thereto of the auxiliary piping, the second chamber being maintained in communication with a point of said auxiliary piping, said diaphragm being operatively connected with said throttling member. in the sense of diminishing the flow cross-secTion of said auxiliary piping when the pressure in said first chamber is greater than the pressure in said second chamber and of increasing the flow-cross-section when the pressure of the second chamber exceeds that of the first chamber.

Claim 5

An internal combustion engine provided with an intake duct, an exhaust duct and an auxiliary piping connected to said exhaust duct to draw a portion of the gases flowing therethrough to discharge them into said intake duct, the improvement including first means sensitive to a pressure drop undergone by the gases which flow through at least a portion of the exhaust duct, second means operably related to the first means and sensitive to a predetermined pressure drop undergone by the gases when flowing through a portion of said auxiliary piping and a member for throttling in a variable manner the auxiliary piping, said member being driven by said first and said second means in the sense of keeping proportional the respectively sensed pressure drops, said first means being sensitive to the gas pressure in a point of the exhaust duct which is downstream of the connection of the auxiliary piping to said exhaust duct and sensitive to the gas pressure at a point of said auxiliary piping which is upstream of said member, and drive said member to throttle said auxiliary piping so as to maintain the sensed pressure proportional to each other, said first means consisting of a deformable diaphragm for separating two chambers, the first chamber being maintained in communication with a point of said exhaust duct which is downstream of the connection thereto of the auxiliary piping, the second chamber being maintained in communication with a point of said auxiliary piping, said diaphragm being operatively connected with said throttling member. in the sense of diminishing the flow cross-secTion of said auxiliary piping when the pressure in said first chamber is greater than the pressure in said second chamber and of increasing the flow-cross-section when the pressure of the second chamber exceeds that of the first chamber.

Claim 6

The internal combustion engine according to claim 1, characterized in that said exhaust duct opens into the atmosphere and said means are sensitive to the pressure at a point of said auxiliary piping and control said throttling means to maintain the sensed pressure in a constant proportion with respect to the atmospherical pressure.

Claim 7

An internal combustion engine provided with an intake duct, an exhaust duct, and an auxiliary piping connected to said exhaust duct to draw a portion of the gases flowing therethrough to discharge them into said intake duct, the improvement including first means sensitive to a pressure drop undergone by the gases which flow through at least a portion of the exhaust duct, second means operably related to the first means and sensitive to a predetermined pressure drop undergone by the gases when flowing through a portion of said auxiliary piping and a member for throttling in a variable manner said auxiliary piping, said member being driven by said first and second means in the sense of keeping proportional the respectively sensed pressure drops, said exhaust duct opening into the atmosphere and said means being sensitive to the pressure at a point of said auxiliary piping and controlling said throttling means to maintain the sensed pressure in a constant proportion with respect to the atmospherical pressure, said means comprising a chamber having a wall consisting of a deformable diaphragm and in communication with a point of said auxiliary piping upstream of said member, the latter being operatively connected to said diaphragm so as to diminish the cross-section of said piping when the pressure in said chamber is subatmospherical and increasing it when the pressure exceeds the atmospherical pressure.

Claim 8

An internal combustion engine provided with an intake duct, an exhaust duct, and an auxiliary piping connected to said exhaust duct to draw a portion of the gases flowing therethrough to discharge them into said intake duct, the improvement including first means sensitive to a pressure drop undergone by the gases which flow through at least a portion of the exhaust duct, second means operably related to the first means and sensitive to a predetermined pressure drop undergone by the gases when flowing through a portion of said auxiliary piping and a member for throttling in a variable manner said auxiliary piping, said member being driven by said first and second means in the sense of keeping proportional the respectively sensed pressure drops, said exhaust duct opening into the atmosphere and said means being sensitive to the pressure at a point of said auxiliary piping and controlling said throttling means to maintain the sensed pressure in a constant proportion with respect to the atmospherical pressure, said means comprising a chamber having a wall consisting of a deformable diaphragm and in communication with a point of said auxiliary piping upstream of said member, the latter being operatively connected to said diaphragm so as to diminish the cross-section of said piping when the pressure in said chamber is subatmospherical and increasing it when the pressure exceeds the atmospherical pressure.

Claim 9

The internal combustion engine according to claim 1, characterized in that in said auxiliary piping there is arranged a member for varying the resistance to gas flow in said piping.

Claim 10

An internal combustion engine according to claim 6, characterized in that said member is driven to vary said resistance by a sensing member of the power delivered by the engine in the sense of diminishing the resistance as the power is increased and vice versa.