Line pressure arrangement for automotive power train including traction company

• US 5,150,761 A
• Filed: 08/14/1990
• Issued: 09/29/1992
• Est. Priority Date: 08/23/1989
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Shimanaka, Shigeki, Kato, Yuji
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): BOEHLER, ANNE MARIE M
• Application Number:
  US07/566,690
• Time in Patent Office: 777 Days
• Field of Search: 180/197, 364/424.1, 364/426.02, 364/426.03
• US Class Current: 180/197
• CPC Class Codes: B60K 28/165 acting on elements of the vehicle drive train other than the propulsion unit and brakes, e.g. transmission, clutch, differential acting on brakes B60T8/17
• CPC Class Codes: F16H 2059/506 Wheel slip
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 61/0021 Generation or control of line pressure

Abstract

The opening degrees of a manually operable engine throttle valve and a traction control controlled throttle valve are compared and the opening degree of the one which is closed the most is used to control the level of line pressure in an automatic transmission.

Claims

1. An automotive power train, comprising:

an internal combustion engine, said internal combustion engine having an induction passage in which first and second serially arranged throttle valves are disposed, the first throttle valve being responsive to the amount of displacement of a manually operable member, the second throttle valve being operatively connected to a servo device;

traction control means for controlling the operation of said servo device in accordance with selected operational parameters which are indicative of traction loss and the presence of wheel slip to adjust the amount of torque being generated by the engine, to thereby improve vehicle traction;

a transmission operatively connected with said internal combustion engine, said transmission including a source of selectively variable line pressure, the variable line pressure source being arranged to be responsive to an input indicative of the engine torque whereby selective application of the line pressure allows selection from four forward and one reverse gear ratios;

a transmission control unit, operatively connected with said traction control means and a sensor which detects the opening degree of the first throttle valve; and

total throttle sensing means for determining which of said first and second throttle valves is closed the most and for supplying an input indicative of engine torque to said line pressure source in accordance with the opening degree of the throttle valve which is closed the most, said total throttle opening sensing means being included in said transmission control unit.

2. An automotive power train, comprising:

an internal combustion engine;

an induction conduit which leads to said engine;

a manually controlled first throttle valve disposed in said induction conduit;

a servo controlled second throttle valve disposed in said induction conduit at a location downstream of said first throttle valve;

traction control means for adjusting an amount of torque generated by the engine to thereby improve vehicle traction, including wheel speed sensors for producing signals from which the presence of wheel slip can be determined, said traction control means being arranged to control a servo device with which said second throttle valve is controlled;

an automatic transmission, including a controllable source of variable line pressure;

a transmission control unit, comprising line pressure control means for determining a required level of line pressure which should be produced by the source of variable line pressure based on an input indicative of engine load to determine which one of four available forward speeds to utilize; and

total throttle sensing means, responsive to the operation of said traction control means and a sensor which senses the opening degree of said first throttle valve, for determining which of the first and second throttle valves is closed the most and for supplying an input indicative of engine load to the line pressure control means based on the opening degree of the throttle valve which is closed the most.