Control system for an automatic transmission clutch in an engine starting operation

• US 5,876,306 A
• Filed: 02/27/1997
• Issued: 03/02/1999
• Est. Priority Date: 02/29/1996
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Murata, Kiyohito
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Parekh, Ankur
• Application Number:
  US08/807,631
• Time in Patent Office: 733 Days
• Field of Search: 477/70, 477/71, 477/74, 477/97, 477/166, 477/170, 477/171, 477/172, 477/174, 477/175, 477/167, 477/67, 192/103 F, 192/103 FA, 192/105 F, 701/54, 701/66, 701/67, 701/68
• US Class Current: 477/175
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: F16F 15/22 Compensation of inertia forces suppression of vibrations of rotating systems by favourable grouping or relative arrangements of the moving members of the system or systems F16F15/20, counterweights F16F15/28; correcting-weights for balancing rotating bodies F16F15/32
• CPC Class Codes: F16H 2057/0012 for reducing drive line oscillations
• CPC Class Codes: F16H 59/36 Inputs being a function of speed
• CPC Class Codes: F16H 61/66254 controlling of shifting being influenced by a signal derived from the engine and the main coupling

Abstract

In the control system of an automatic transmission for a motor vehicle wherein power delivered from an engine is transmitted to a gear shift mechanism through a damper and then transmitted from the gear shift mechanism to driving wheels through a starting clutch, when an engine speed detected by engine speed sensor (in FIG. 1) is not higher than a predetermined value in the engine starting operation, an engageable element (in FIG. 1) constituting the gear shift mechanism is released, and when the engine speed is higher than the predetermined value, the engageable element is brought into engagement, thereby to alter the resonance point of a rotary system including the damper and to prevent the damper from resonating, so that a vibration of large amplitude does not occur in the engine starting operation.

Claims

1. A control system of an automatic transmission wherein power delivered from an engine is transmitted to a gear shift mechanism through a damper, and the power is transmitted from the gear shift mechanism to driving wheels through a starting clutch, comprising:

an engine speed sensor for detecting an engine speed; and

a control unit for controlling an engagement state of an engageable element of said gear shift mechanism on the basis of the engine speed in an engine starting operation, thereby to alter an inertial mass downstream of said damper in dependence on said engine speed;

said control unit releasing the engageable element of said gear shift mechanism when said engine speed is not higher than a predetermined value, and bringing said engageable element of said gear shift mechanism into engagement when said engine speed is higher than the predetermined value, so as to suppress occurrence of resonance of said damper.

2. A control system of an automatic transmission as defined in claim 1, wherein said engageable element of said gear shift mechanism is a clutch for a forward movement of an motor vehicle.

3. A control system of an automatic transmission as defined in claim 1, wherein said engageable element of said gear shift mechanism is a brake for a reverse movement of an motor vehicle.