Automatic mechanical transmission start control system

• US 5,097,724 A
• Filed: 10/22/1990
• Issued: 03/24/1992
• Est. Priority Date: 04/14/1989
• Status: Expired due to Term

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Braun, Eugene R.
• Primary Examiner(s): Braun, Leslie A.
• Assistant Examiner(s): Levi, Benjamin
• Application Number:
  US07/600,657
• Time in Patent Office: 519 Days
• Field of Search: 74/846, 74/857, 74/859, 74/860, 74/866, 74/873, 74/875, 74/874, 192/0.072, 192/0.076, 192/0.094, 192/4 A, 192/13 R
• US Class Current: 477/73
• CPC Class Codes: B60T 13/662 characterised by specified functions of the control system components
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/104 Output speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/021 Clutch engagement state
• CPC Class Codes: B60W 2710/18 Braking system
• CPC Class Codes: B60W 30/18027 Drive off, accelerating from standstill
• CPC Class Codes: F16H 2312/02 Driving off

Abstract

Preferred embodiments of a mechanical transmission start control system are provided which employ a central processing unit (10) operative to process signals indicative of throttle foot pedal position (26); engine speed (20); transmission input speed (14); and transmission output speed (16), and to control either or both the degree of clutch or friction coupling and brake engagement in a manner predetermined to provide smooth start-up when vehicle speed is less than a predetermined value "K".

Claims

1. An automatic mechanical transmission start control system for vehicles having brakes and a throttle controlled engine, said transmission having a plurality of gear ratio combinations selectively engageable between a transmission output shaft and a transmission input shaft operatively connected to the engine by means of a selectively engageable and disengageable friction coupling, said system including an automatic friction coupling actuating member, a throttle control member, an automatic vehicle brake actuating member, an operator positional change gear selector member, including a neutral position and positions in which said gear ratio combinations are selectively engaged, and an information processing unit having means for receiving a plurality of signals including:

(1) an input signal indicative of the position of said throttle control member or of the amount of fuel supplied to the engine;

(2) an input signal indicative of vehicle speed;

(3) an input signal indicating when the transmission is in neutral, said processing unit including means for processing said input signals and providing an output signal therefrom such that, when the vehicle speed signal is less than a predetermined value, said start control system is operative such that, (i) when the transmission is in neutral and the throttle is at idle the output signal is effective to instruct the coupling actuating member to cause the friction coupling to assume a disengaged condition and (ii) when the transmission is not in neutral and the throttle is at idle the output signal is effective to instruct the brake actuating member to cause the brakes to assume a predetermined partially engaged condition and (iii) when the throttle is at idle and the transmission is not in neutral, the output signal is effective to instruct the friction coupling actuating member to cause the friction coupling to assume a partially engaged condition.

2. The control system of claim 1 wherein the output signal is further effective to instruct the throttle control member to adjust the fuel as necessary to hold the engine at a predetermined idle speed.

3. The control system of claim 1 such that, when the throttle is at idle and the transmission is not in neutral, the output signal is further effective to instruct the friction coupling actuating member to cause the friction member to assume an engaged condition operative to decrease the engine speed a predetermined amount.

4. The control system of claim 3 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to stop engagement.

5. The control system of claim 4 wherein the output signal is further effective to instruct the throttle control member to adjust the fuel as necessary to hold the engine at a predetermined idle speed.

6. The control system of claims 2, 3, 4 or 5 further operative such that, when the throttle is not at idle and the transmission is not in neutral, the output signal is effective to instruct the brake actuating member to cause the brakes to disengage at a predetermined rate.

7. The control system of claim 6 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to assume a fully engaged condition.

8. An automatic mechanical transmission start control system for vehicles having brakes and a throttle controlled engine, said transmission having a plurality of gear ratio combinations selectively engageable between a transmission output shaft and a transmission input shaft operatively connected to the engine by means of a selectively engageable or disengageable friction coupling, said system including an automatic friction coupling actuating member, a throttle control member, an automatic vehicle brake actuating member, an operator positional change gear selector member, including a neutral position and positions in which said gear ratio combinations are selectively engaged, and an information processing unit having means for receiving a plurality of signals including:

(1) an input signal indicative of the position of said throttle control member or of the amount of fuel supplied to the engine;

(2) an input signal indicative of vehicle speed;

(3) an input signal indicating when the transmission is in neutral, said processing unit including means for processing said input signals and providing an output signal therefrom such that, when the vehicle speed signal is less than a predetermined value, said start control system is operative such that, (i) when the transmission is in neutral and the throttle is at idle the output signal is effective to instruct the coupling actuating member to cause the friction coupling to assume a disengaged condition and (ii) when the transmission is not in neutral and the throttle is at idle the output signal is effective to instruct the friction coupling actuating member to cause the friction coupling to assume a predetermined partially engaged condition, such that when the throttle is at idle and the transmission is not in neutral and the brakes are in an engaged condition, the output signal is further effective to instruct the brake actuating member to cause the brakes to assume a predetermined partially engaged condition.

9. The control system of claim 8 further operative such that, when the throttle is not at idler and the transmission is not in neutral, the output signal is effective to instruct the brakes actuating member to cause the brakes to disengage at a predetermined rate.

10. The control system of claim 9 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to assume a fully engaged condition.

11. An automatic mechanical transmission start control system for vehicles having brakes and a throttle controlled engine, said transmission having a plurality of gear ratio combinations selectively engageable between a transmission input shaft operatively connected to the engine by means of a selectively engageable and disengageable friction coupling actuating member, an automatic vehicle brake actuating member, a throttle control member, an operator positional change gear selector member, including a neutral position and positions in which said gear ratio combinations are selectively engaged, and an information processing unit having means for receiving a plurality of signals including:

(1) an input signal indicative of the position of said throttle control member or of the amount of fuel supplied to the engine;

(2) an input signal indicative of vehicle speed;

(3) an input signal indicating when the transmission is in neutral, said processing unit including means for processing said input signals and providing an output signal therefrom such that, when the vehicle speed signal is less than a predetermined value, said start control system is operative such that, (i) when the transmission is in neutral and the throttle is at idle the output signal is effective to instruct the coupling actuating member to cause a friction coupling to assume a disengaged condition and (ii) when the transmission is not in neutral and the throttle is at idle and the brakes are in an engaged condition, the output signal is effective to instruct the brake actuating member to cause the friction coupling to assume a predetermined partially engaged condition.

12. The control system of claim 11 such that, when the throttle is at idle and the transmission is not in neutral and the brakes are in either the engaged or disengaged condition, the output signal is further effective to instruct the throttle control member to adjust the fuel as necessary to hold the engine at a predetermined idle speed.

13. The control system of claim 12 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to stop engagement at a predetermined decrease in engine speed.

14. The control system of claim 12 or 13 such that, when the throttle is not at idler and the transmission is not in neutral, the output signal is effective to instruct the brake actuating member to cause the brakes to disengage at a predetermined rate.

15. The control system of claim 14 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to assume a fully engaged condition.

16. An automatic mechanical transmission start control system for vehicles having brakes and a throttle controlled engine, said transmission having a plurality of gear ratio combinations selectively engageable between a transmission output shaft and a transmission input shaft operatively connected to the engine by means of a selectively engageable and disengageable friction coupling actuating member, an automatic vehicle brake actuating member, a throttle control member, an operator positional change gear selector member, including a neutral position and positions in which said gear ratio combinations are selectively engaged, and an information processing unit having means for receiving a plurality of signals including:

(1) an input signal indicative of the position of said throttle control member or of the amount of fuel supplied to the engine;

(2) an input signal indicative of vehicle speed;

(3) an input signal indicating when the transmission is in neutral, said processing unit including means for processing said input signals and providing an output signal therefrom such that, when the vehicle speed signal is less than a predetermined value, said start control system is operative such that, (i) when the transmission is in neutral and the throttle is at idle the output signal is effective to instruct the coupling actuating member to cause a friction coupling to assume a disengaged condition and (ii) when the transmission is not in neutral and the throttle is at idle and the brakes are in an engaged condition, the output signal is effective to instruct the brake actuating member to cause the brakes to assume a predetermined partially engaged condition.

17. The control system of claim 16 such that, when the throttle is not at idle and the transmission is not in an engaged condition, the output signal is effective to instruct the friction coupling actuating member to cause the friction coupling to assume a predetermined partially engaged condition.

18. The control system of claim 17 wherein the output signal is further effective to instruct the throttle control member to adjust fuel as necessary to hold the engine at a predetermined idle speed.

19. The control system of claim 18 wherein the output signal is further effective to instruct the throttle member to increase the amount of fuel supplied to the engine by a predetermined amount.

20. The control system of claim 19 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to assume a disengaged condition.

21. The control system of claim 20 wherein the output signal is further effective to instruct the brake actuating member to cause the brakes to disengage at a predetermined rate.

22. The control system of claim 21 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to assume a fully engaged condition.

23. The control system of claim 16 such that, when the throttle is at idler and the transmission is not in neutral and the brakes are in either the engaged or disengaged condition, the output signal is effective to instruct the friction coupling actuating member to cause the friction coupling to maintain an engaged condition until the engine speed stops.

24. The control system of claim 23 wherein the output signal is further effective to instruct the throttle control member to adjust fuel as necessary to hold the engine at a predetermined idler speed.

25. The control system of claim 24 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to stop engagement.

26. The control system of claim 23, 24, or 25 such that, when the throttle is not at idler and the transmission is not in neutral, the output signal is effective to instruct the brake actuating member to disengage the brakes at a predetermined rate.

27. The control system of claim 26 wherein the output signal is further effective to instruct the friction coupling actuating member to cause the friction coupling to assume a fully engaged condition.