Fast valve actuation system for an automatic transmission

Patent metadata

Field	Value
Publication number	US-9784366-B2
Application number	US-201414508772-A
Country	US
Kind code	B2
Filing date	Oct 7, 2014
Priority date	Dec 16, 2009
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A fast valve actuation system for an automatic vehicle transmission includes a pair of spring-biased shift valves. Solenoids control the application of pressurized hydraulic fluid to the head of each of the shift valves. Each shift valve has at least one port that is coupled to a fluid chamber of a torque transferring mechanism of an automatic transmission. The position of each of the shift valves determines whether its ports are connected with fluid pressure. Fluid passages connect the head of each shift valve to the spring pocket of the other shift valve.

First claim

What is claimed is:

1. A system for a transmission, the system comprising:
a variable-ratio unit,
a hydraulic circuit fluidly coupled to the variable-ratio unit, the hydraulic circuit including
a first fluid chamber pressurizable to apply a first torque transmitting mechanism of the variable-ratio unit,
a second fluid chamber pressurizable to apply a second torque transmitting mechanism of the variable-ratio unit,
a first shift valve fluidly coupled to the first fluid chamber to selectively direct fluid pressure to the first fluid chamber, the first shift valve having a first valve head and a first spring chamber axially spaced from the first valve head,
a first electro-hydraulic actuator fluidly coupled to the first valve head of the first shift valve and actuatable by electrical signals to output fluid pressure thereto,
a second shift valve fluidly coupled to the second fluid chamber to selectively direct fluid pressure to the second fluid chamber, the second shift valve including a second valve head and a second spring chamber axially spaced from the second valve head, and
a first fluid passage that fluidly couples the first valve head of the first shift valve directly to the second spring chamber of the second shift valve,
wherein the first electro-hydraulic actuator is selectively coupled to the second spring chamber through the first valve head and the first fluid passage, and

an electronic control unit coupled to the hydraulic circuit, the electronic control unit including computer circuitry configured to (i) detect a change in torque direction and (ii) actuate the first electro-hydraulic actuator to output fluid pressure to the first valve head to stroke the first shift valve and destroke the second shift valve in rapid succession in response to the detected change in torque direction so that the second fluid chamber is connected to fluid pressure and the first fluid chamber is disconnected from fluid pressure in rapid succession.

2. The system of claim 1 , wherein the hydraulic circuit includes (i) a second electro-hydraulic actuator fluidly coupled to the second valve head of the second shift valve and actuatable by electrical signals to output fluid pressure thereto, and (ii) a second fluid passage separate from the first fluid passage that fluidly couples the second valve head of the second shift valve directly to the first spring chamber of the first shift valve.

3. The system of claim 2 , wherein the second electro-hydraulic actuator is selectively coupled to the first spring chamber through the second valve head and the second fluid passage.

4. The system of claim 2 , wherein the first and second fluid passages do not intersect with each other.

5. The system of claim 1 , wherein the computer circuitry is configured to direct the first electro-hydraulic actuator to substantially simultaneously output fluid pressure to the first valve head of the first shift valve and the first fluid passage.

6. The system of claim 1 , wherein the first and second torque transmitting mechanisms are variator disk actuators.

7. The system of claim 1 , wherein the first and second torque transmitting mechanisms are clutches.

8. The system of claim 1 , wherein (i) the transmission is operable in at least three different forward operating modes, and (ii) the computer circuitry is configured to detect the change in torque direction in one of the forward operating modes.

9. The system of claim 1 , wherein (i) the transmission is operable in at least three different forward operating modes, and (ii) the computer circuitry is configured to detect the change in torque direction during a transition from one of the forward operating modes to another of the forward operating modes.

10. A system for a transmission, the system comprising:
a variable-ratio unit including a first torque transmitting mechanism and a second torque transmitting mechanism,
a valve assembly actuatable to selectively connect a first fluid chamber coupled to the first torque transmitting mechanism to fluid pressure and disconnect a second fluid chamber coupled to the second torque transmitting mechanism from fluid pressure in rapid succession, the valve assembly including
a first shift valve having a first valve head and a first spring chamber axially spaced from the first valve head,
a first electro-hydraulic actuator fluidly coupled to the first valve head of the first shift valve and actuatable by electrical signals to output fluid pressure thereto,
a second shift valve having a second valve head and a second spring chamber axially spaced from the second valve head, and
a second electro-hydraulic actuator fluidly coupled to the second valve head of the second shift valve and actuatable by electrical signals to output fluid pressure thereto, and

an electronic control unit coupled to the valve assembly, the electronic control unit including computer circuitry configured to (i) de-actuate the first electro-hydraulic actuator so that fluid pressure is directed through the first shift valve to the first fluid chamber to apply the first torque transmitting mechanism and actuate the second electro-hydraulic actuator to apply fluid pressure to the second valve head and connect the second electro-hydraulic actuator to the first spring chamber of the first shift valve through the second valve head, (ii) detect a change in torque direction, and (iii) stroke the first shift valve and destroke the second shift valve in rapid succession in response to the detected change in torque direction.

11. The system of claim 10 , wherein (i) the computer circuitry is configured to actuate the first electro-hydraulic actuator to apply fluid pressure to the first valve head of the first shaft valve, connect the first electro-hydraulic actuator to the second spring chamber of the second shift valve through the first valve head, and disconnect the first fluid chamber from fluid pressure to stroke the first shift valve, and (ii) the computer circuitry is configured to de-actuate the second electro-hydraulic actuator to remove fluid pressure from the second valve head of the second shift valve, disconnect the second electro-hydraulic actuator from the first spring chamber of the first shift valve, and direct fluid pressure through the second shift valve to the second fluid chamber to apply the second torque transmitting mechanism to destroke the second shift valve.

12. The system of claim 11 , wherein the computer circuitry is configured to de-actuate the first electro-hydraulic actuator to couple a first pressure control valve to the first fluid chamber.

13. The system of claim 12 , wherein the computer circuitry is configured to de-actuate the second electro-hydraulic actuator to couple a second pressure control valve to the second fluid chamber.

14. The system of claim 13 , wherein the computer circuitry is configured to actuate the second electro-hydraulic actuator to couple the second fluid chamber to a third pressure control valve.

15. The system of claim 10 , wherein the computer circuitry is configured to stroke the first shift valve and destroke the second shift valve in rapid succession in response to the detected change in torque direction in less than about 0.08 seconds.

16. The system of claim 10 , wherein the first and second torque transmitting mechanisms are variator disk actuators.

17. The system of claim 10 , wherein (i) the transmission is operable in at least three different forward operating modes, and (ii) the computer circuitry is configured to detect the change in torque direction in one of the forward operating mod

Assignees

• Allison Transm Inc

Inventors

• Long Charles F
• Weber Darren J

Classifications

• F16H61/0206

  Layout of electro-hydraulic control circuits, e.g. arrangement of valves · CPC title

• F16H61/0276 Primary

  Elements specially adapted for hydraulic control units, e.g. valves · CPC title

• Y10T74/20024

  Fluid actuator · CPC title

• F16K11/14

  operated by one actuating member, e.g. a handle (with one plug turning in another F16K11/12) · CPC title

• F16H61/38

  Control of exclusively fluid gearing · CPC title