Detent plunger assembly and control method

• US 6,324,928 B1
• Filed: 04/27/2000
• Issued: 12/04/2001
• Est. Priority Date: 04/27/2000
• Status: Expired due to Term

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Hughes, Douglas A.
• Primary Examiner(s): Estremsky, Sherry
• Assistant Examiner(s): PANG, ROGER L
• Application Number:
  US09/559,570
• Time in Patent Office: 586 Days
• Field of Search: 477/109, 477/110, 477/124, 477/125, 743/35, 743/39, 744/732.1, 744/732.5
• US Class Current: 74/335
• CPC Class Codes: F16H 2059/462 Detecting synchronisation, i.e. speed difference is approaching zero
• CPC Class Codes: F16H 61/702 using electric or electrohydraulic control means
• CPC Class Codes: F16H 63/34 Locking or disabling mechanisms
• CPC Class Codes: Y10T 74/19251 Control mechanism

Abstract

A detent plunger assembly (48) for selectively inhibiting shift lever (42) movement in a controller-assisted, manually shifted transmission system (10). The assembly includes a differential area piston (86) and a light biasing spring (110) for causing said plunger to apply a light inhibiting force when system air (S) is not available, such as at vehicle startup.

Claims

1. A detent plunger assembly (48) for selectively controlling movement of a manually operated shift lever (42) in a controller-assisted, manually shifted vehicular transmission system (10), said shift lever movable in a predetermined shift pattern to move a shift member (70) from a neutral position to at least one engaged position for engaging a selected gear ratio, said system including a system controller for receiving input signals indicative of system operating conditions and processing same according to logic rules to issue command output signals to system actuators, including a detent plunger actuator (108), said plunger assembly comprising:

a detent plunger (82) movable in a first direction to inhibit movement of said shift member and in a second, opposite direction for not inhibiting movement of said shift member;

a differential area piston (86) associated with said plunger for imparting movement thereto, said piston having a first piston surface (104) defining a first chamber (106) and a second piston surface (100) defining a second chamber (102), said first piston surface having an area greater than the area of said second piston surface, pressurization of said first chamber urging said plunger to move in said first direction and pressurization of said second chamber urging said plunger to move in said second direction;

a first conduit (106A) connecting said first chamber to a a selected one of common source of pressurized fluid (S) and an exhaust (EXH), a second conduit (102A) constantly connecting said second chamber to said common source of pressurized fluid; and

a spring (110) biasing said plunger in said first direction, said spring applying a force less than the force of pressurized fluid from said common source acting on said second piston surface.

2. The assembly of claim 1 wherein said plunger (82) is provided with a tapered tip (80) for engaging a tapered groove (76) in said shift

member in said shift member when said plunger is displaced in said first direction.

3. The plunger assembly of claim 1 wherein said common source of pressurized fluid is a vehicle onboard pressurized air system.

4. The plunger assembly of claim 2 wherein said common source of pressurized fluid is a vehicle onboard pressurized air system.

5. The plunger assembly of claim 1 wherein said actuator (108) includes a solenoid-controlled valve for selectively pressurizing and exhausting said first conduit.

6. The assembly of claim 5 wherein said solenoid-controlled valve is controlled by a pulse width-modulated command signal (PWM) from said system controller (52).

7. The plunger assembly of claim 2 wherein said actuator (108) includes a solenoid-controlled valve for selectively pressurizing and exhausting said first conduit.

8. The assembly of claim 7 wherein said solenoid-controlled valve is controlled by a pulse width-modulated command signal (PWM) from said system controller (52).

9. The plunger assembly of claim 3 wherein said actuator (108) includes a solenoid-controlled valve for selectively pressurizing and exhausting said first conduit.

10. The assembly of claim 9 wherein said solenoid-controlled valve is controlled by a pulse width-modulated command signal (PWM from said system controller (52).

11. The assembly of claim 1 wherein said system controller includes logic rules for:

sensing a position of said shift member;

if (a) said shift member is in a neutral position and (b) one of (i) there is an absence of conditions indicative of an intention to engage a selected gear ratio, and (ii) there is a presence of conditions indicative of an intention to engage said selected gear ratio but substantially synchronous conditions for engaging said selected gear ratio do not exist, then automatically causing said first conduit to be pressurized; and

if (a) said shift member is in the neutral position, (b) there is a presence of conditions indicative of an intention to engage said selected gear ratio, and (c) substantially synchronous conditions for engaging said gear ratio exist, automatically causing said first conduit to be exhausted.

12. The assembly of claim 2 wherein said system controller includes logic rules for:

sensing a position of said shift member;

if (a) said shift member is in a neutral position and (b) one of (i) there is an absence of conditions indicative of an intention to engage a selected gear ratio, and (ii) there is a presence of conditions indicative of an intention to engage said selected gear ratio but substantially synchronous conditions for engaging said selected gear ratio do not exist, then automatically causing said first conduit to be pressurized; and

if (a) said shift member is in the neutral position, (b) there is a presence of conditions indicative of an intention to engage said selected gear ratio, and (c) substantially synchronous conditions for engaging said gear ratio exist, automatically causing said first conduit to be exhausted.

13. The assembly of claim 3 wherein said system controller includes logic rules for:

sensing a position of said shift member;

if (a) said shift member is in a neutral position and (b) one of (i) there is an absence of conditions indicative of an intention to engage a selected gear ratio, and (ii) there is a presence of conditions indicative of an intention to engage said selected gear ratio but substantially synchronous conditions for engaging said selected gear ratio do not exist, then automatically causing said first conduit to be pressurized; and

if (a) said shift member is in the neutral position, (b) there is a presence of conditions indicative of an intention to engage said selected gear ratio, and (c) substantially synchronous conditions for engaging said gear ratio exist, automatically causing said first conduit to be exhausted.

14. The assembly of claim 7 wherein said system controller includes logic rules for:

sensing a position of said shift member;

if (a) said shift member is in a neutral position and (b) one of (i) there is an absence of conditions indicative of an intention to engage a selected gear ratio, and (ii) there is a presence of conditions indicative of an intention to engage said selected gear ratio but substantially synchronous conditions for engaging said selected gear ratio do not exist, then automatically causing said first conduit to be pressurized; and

if (a) said shift member is in the neutral position, (b) there is a presence of conditions indicative of an intention to engage said selected gear ratio, and (c) substantially synchronous conditions for engaging said gear ratio exist, automatically causing said first conduit to be exhausted.

15. The assembly of claim 1 wherein said system controller includes logic rules for:

sensing the position of said shift member;

if said shift member is in an engaged position, sensing a presence or absence of conditions indicative of an intent to disengage an engaged gear ratio; and

if (a) said shift member is in the engaged position and (b) there is an absence of conditions indicative of an intent to disengage said engaged gear ratio, then automatically causing said first conduit to be pressurized.

16. The assembly of claim 2 wherein said system controller includes logic rules for:

sensing the position of said shift member;

if said shift member is in an engaged position, sensing a presence or absence of conditions indicative of an intent to disengage an engaged gear ratio; and

if (a) said shift member is in the engaged position and (b) there is an absence of conditions indicative of an intent to disengage said engaged gear ratio, then automatically causing said first conduit to be pressurized.

17. The assembly of claim 3 wherein said system controller includes logic rules for:

sensing the position of said shift member;

if said shift member is in an engaged position, sensing a presence or absence of conditions indicative of an intent to disengage an engaged gear ratio; and

if (a) said shift member is in the engaged position and (b) there is an absence of conditions indicative of an intent to disengage said engaged gear ratio, then automatically causing said first conduit to be pressurized.

18. The assembly of claim 7 wherein said system controller includes logic rules for:

sensing the position of said shift member;

if said shift member is in an engaged position, sensing a presence or absence of conditions indicative of an intent to disengage an engaged gear ratio; and

if (a) said shift member is in the engaged position and (b) there is an absence of conditions indicative of an intent to disengage said engaged gear ratio, then automatically causing said first conduit to be pressurized.