Motor vehicle equipped with turbocharger

Claim 2

A motor vehicle having an engine body formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combusion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; vehicle speed sensing means for sensing a vehicle cruising speed of a predetermined level or higher to produce an electric signal; and means, responsive to said vehicle speed sensing means, for decreasing the pressure of air passing through said intake passageway downstream of said compressor wheel on receiving said electrical signal from said vehicle speed sensing means.

Claim 3

A motor vehicle as claimed in claim 1, in which the pressure decreasing means comprises means defining a intake air by-pass passage having first and second ends which are connected to said intake passageway, said first and second ends being connected to upstream and downstream sides of the compressor wheel of said turbocharger, respectively, and a valve operatively disposed in said intake air by-pass passage, said valve being opened to provide communication between the upstream and downstream sides of the compressor wheel when actuated on receiving said electric signal from said vehicle speed sensing means.

Claim 4

A motor vehicle as claimed in claim 2, in which said vehicle speed sensing means comprises a speedometer for measuring vehicle cruising speed, and switching means for producing said electric signal when said speedometer indicates that the vehicle cruising speed reaches the predetermined level or higher.

Claim 5

A motor vehicle as claimed in claim 3, in which the pressure decreasing means further comprises an actuating means for actuating the valve on receiving said electric signal from said switching means.

Claim 6

A motor vehicle as claimed in claim 4, further comprising fuel injectors constituting part of an electronically controlled fuel injection system, said fuel injectors being disposed at the branch runners of said intake passageway, respectively, a throttle valve operatively disposed in said intake passageway upstream of said fuel injectors to control the flow amount of air inducted into the combustion chambers; an air flow meter operatively disposed in said intake passageway upstream of the compressor wheel of said turbocharger to measure the flow amount of air passing through said intake passageway in order to provide a control signal to said electronically controlled fuel injection system.

Claim 7

A motor vehicle as claimed in claim 5, in which said intake air by-pass passage is located such that the first end thereof is connected to said intake passageway downstream of said air flow meter, and said second end thereof is connected to said intake passageway upstream of said throttle valve.

Claim 8

A motor vehicle as claimed in claim 4, in which said valve is a solenoid valve having a moveable valve head which is normally biased to close said intake air by-pass passage, the moveable valve head being attracted to the solenoid coil of said solenoid valve to open said intake air by-pass passage when the solenoid coil is energized.

Claim 9

A motor vehicle as claimed in claim 7, in which said actuating means includes a relay switch electrically connected to the solenoid coil of said solenoid valve, said relay switch energizing the solenoid valve then closed.

Claim 10

A motor vehicle as claimed in claim 8, in which said switching means is a vehicle speed switch operatively connected to said speedometer, said vehicle speed switch causing said relay switch to close on receiving from said speedometer an information signal indicating that the vehicle cruising speed reaches the predetermined level or higher.

Claim 11

A motor vehicle as claimed in claim 1, further comprising means defining an exhaust gas passageway through which the combustion chambers are communicable with atmospheric air, the turbine wheel of said turbocharger being rotatably disposed in said exhaust gas passageway.

Claim 12

A motor vehicle as claimed in claim 10, in which the pressure decreasing means comprises means defining an exhaust gas by-pass passage having first and second ends which are connected to said exhaust gas passageway, said first and second ends being connected to the upstream and downstream sides of the turbine wheel of said turbocharger, respectively, and a valve operatively disposed in said exhaust gas by-pass passage, said valve being opened to provide communication between the upstream and downstream sides of the compressor wheel when actuated on receiving said electric signal from said vehicle speed sensing means.

Claim 13

A motor vehicle as claimed in claim 11, further comprising a catalytic converter means for oxidizing carbon monoxide and hydrocarbons and reducing nitrogen oxides, said catalytic converter means being operatively disposed in said exhaust gas passageway downstream of the second end of said second by-pass passage.

Claim 14

A motor vehicle having an engine body formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combustion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; a speedometer for measuring the cruising speed of the vehicle; switching means operatively connected to said speedometer to produce an electric signal when said speedometer indicates that the vehicle cruising speed reaches a predetermined level or higher; and means for decreasing the pressure of air passing through said intake passageway downstream of said compressor wheel on receiving said electric signal from said switching means.

Claim 15

A motor vehicle having an engine body formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combustion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; a speedometer for measuring the cruising speed of the vehicle; switching means operatively connected to said speedometer to produce an electric signal when said speedometer indicates that the vehicle cruising speed reaches a predetermined level or higher; and means for decreasing the pressure of air passing through said intake passageway downstream of said compressor wheel on receiving said electric signal from said switching means.

Claim 16

A motor vehicle having an engine body formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combustion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; means defining an intake air by-pass passage having first and second ends which are connected to said intake passageway, said first and second ends being connected to upstream and downstream sides of the compressor wheel of said turbocharger, respectively; a speedometer for measuring the cruising speed of the vehicle; switching means operatively connected to said speedometer to produce an electric signal when said speedometer indicates that the vehicle speed reaches a predetermined high level or higher; and a valve operatively disposed in said intake air by-pass passage, said valve being opened to provide communication between the upstream and downstream sides of the compressor wheel when actuated on receiving said electric signal from said switching means.

Claim 17

A motor vehicle having an engine body formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combustion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; means defining an intake air by-pass passage having first and second ends which are connected to said intake passageway, said first and second ends being connected to upstream and downstream sides of the compressor wheel of said turbocharger, respectively; a speedometer for measuring the cruising speed of the vehicle; switching means operatively connected to said speedometer to produce an electric signal when said speedometer indicates that the vehicle speed reaches a predetermined high level or higher; and a valve operatively disposed in said intake air by-pass passage, said valve being opened to provide communication between the upstream and downstream sides of the compressor wheel when actuated on receiving said electric signal from said switching means.

Claim 18

A motor vehicle having an engine formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combustion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; means defining an exhaust gas passageway through which the combustion chambers are communicable with atmospheric air, the turbine wheel of said turbocharger being rotatably disposed in said exhaust gas passageway; means defining an exhaust gas by-pass passage having first and second ends which are connected to said exhaust gas passageway, said first and second ends being connected to the upstream and downstream sides of the turbine wheel of said turbocharger, respectively; a speedometer for measuring the cruising speed of the vehicle; switching means operatively connected to said speedometer to produce an electric signal when said speedometer indicates that the vehicle cruising speed reaches a predetermined level or higher; and a valve operatively disposed in said exhaust gas by-pass passageway, said valve being opened to provide communication between the upstream and downstream sides of the turbine wheel when actuated on receiving said electric signal from said switching means.

Claim 19

A motor vehicle having an engine formed with combustion chambers, comprising: means defining an intake passageway through which the combustion chambers are communicable with atmospheric air to supply the combustion chambers with air; a turbocharger having a compressor wheel rotatably disposed in said intake passageway to pressurize air passing through said intake passageway, said turbocharger being driven by the pressure of exhaust gases discharged from the combustion chambers; means defining an exhaust gas passageway through which the combustion chambers are communicable with atmospheric air, the turbine wheel of said turbocharger being rotatably disposed in said exhaust gas passageway; means defining an exhaust gas by-pass passage having first and second ends which are connected to said exhaust gas passageway, said first and second ends being connected to the upstream and downstream sides of the turbine wheel of said turbocharger, respectively; a speedometer for measuring the cruising speed of the vehicle; switching means operatively connected to said speedometer to produce an electric signal when said speedometer indicates that the vehicle cruising speed reaches a predetermined level or higher; and a valve operatively disposed in said exhaust gas by-pass passageway, said valve being opened to provide communication between the upstream and downstream sides of the turbine wheel when actuated on receiving said electric signal from said switching means.