Engine torque control system

• US 7,229,373 B2
• Filed: 02/25/2004
• Issued: 06/12/2007
• Est. Priority Date: 02/27/2003
• Status: Active Grant

• Current Assignee: Jatco Limited (Nissan Motor Co., Ltd.)
• Original Assignee: Jatco Limited (Nissan Motor Co., Ltd.)
• Inventors: Kodama, Yoshihisa, Yamamoto, Masahiro, Tanaka, Hiroyasu, Shimanaka, Shigeki
• Primary Examiner(s): Charles; Marcus
• Application Number:
  US10/787,012
• Publication Number:
  US 20040171444A1
• Time in Patent Office: 1,203 Days
• Field of Search: 474/18, 474/28, 477 43- 49, 701 34- 36, 701/54, 701/63, 701/95
• US Class Current: 474/28
• CPC Class Codes: F16H 2061/124 Limiting the input power, torque or speed
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: F16H 61/66272 characterised by means for controlling the torque transmitting capability of the gearing

Abstract

In case information such as an actual gear ratio is not stored in an EEPROM 28 due to a trouble of a backup power source 29 or like when an initialization operation of a step motor 27 is performed at the time of start of a vehicle or during stoppage of the vehicle, an output torque of an engine is limited before the initialization operation. Thereby, even if an accelerator is depressed during the initialization operation of the step motor 27 in which a sufficient primary pulley pressure cannot be ensured, the output torque of the engine is limited, so that torque inputted to a V-belt type continuously variable transmission is small and slippage does not occurs between the primary pulley and a secondary pulley.

Claims

1. A torque controlling system for use with a V-belt type continuously variable transmission for a vehicle in which a V-belt is wound between a primary pulley of an input side connected to an engine and a secondary pulley of an output side, a primary pulley pressure acting on the primary pulley and a secondary pulley pressure acting on the secondary pulley are generated respectively by using a line pressure as an original pressure, and a shift actuator is set to an operating position corresponding to a target gear ratio, whereby a differential pressure is generated between the primary pulley pressure and the secondary pulley pressure to change widths of V-shaped grooves of the primary pulley and the secondary pulley so that an actual gear ratio that is obtained from speed ratios of the primary pulley and the secondary pulley becomes equal to the target gear ratio, comprising:

a storing section for storing a pulley information immediately before the vehicle is stopped;

storage determining means for determining whether the pulley information is stored in the storing section, and

torque limiting means for performing a limitation of an input torque to the primary pulley,

wherein in case the storage determining means determines that the pulley information is not stored in the storing section before an initialization operation to set the shift actuator to a reference position is performed, the limitation of the input torque to the primary pulley is performed by the torque limiting means.

2. An engine torque controlling system according to claim 1, wherein the input torque to the primary pulley is equal to an output torque of the engine.

3. An engine torque controlling system according to claim 1 or 2, wherein the pulley information includes at least one of a gear ratio of the V-belt type continuously variable transmission and the operating position of the shift actuator.

4. An engine torque controlling system according to one of claims 1 or 2, wherein the initialization operation of the shift actuator is performed when the engine is started or when the vehicle is stopped.

5. An engine torque controlling system according to claim 3, wherein the initialization operation of the shift actuator is performed when the engine is started or when the vehicle is stopped.