DRIVE DEVICE FOR VEHICLE

• US 20120202648A1
• Filed: 01/31/2012
• Published: 08/09/2012
• Est. Priority Date: 02/04/2011
• Status: Active Grant

• Current Assignee: Subaru Corp.
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Yamazaki, Yoshinobu, Ito, Susumu, KIKURA, Takaharu, Kakihara, Yusuke, Kaneda, Kensuke
• Granted Patent: US 8,814,741 B2
• Time in Patent Office: Days
• US Class Current: 477/87
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/107 with endless flexible members
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 30/18054 at stand still, e.g. engine in idling state hill holding B60W30/18118
• CPC Class Codes: F16H 2061/6608 Control of clutches, or brakes for forward-reverse shift
• CPC Class Codes: F16H 2312/14 Going to, or coming from standby operation, e.g. for engine start-stop operation at traffic lights

Abstract

There is provided a drive device for a vehicle. A forward clutch that is engaged during forward driving is provided in a power transmission path between an engine and a drive wheel. A spring is incorporated in an engagement oil chamber of the forward clutch, thereby causing the forward clutch to be held in a slipping state or an engaged state through the spring force even during an idling stop that suffers from reduced control oil pressure. This arrangement can prevent the forward clutch from producing an engagement shock during an engine restart. In addition, an input clutch driven by an electric actuator is provided in the power transmission path. With this arrangement, neutral control can be performed by disengaging the input clutch even if the forward clutch which is to be held in a slipping state or an engaged state is provided.

Claims

1. A drive device for a vehicle provided with an engine that is automatically shut down under a predetermined shutdown condition and is automatically restarted under a predetermined restart condition, the drive device for a vehicle comprising:

a friction engagement mechanism that is provided in a power transmission path between the engine and a drive wheel and moves a hydraulic piston in an engagement direction to bring a friction plate into an engaged state and moves the hydraulic piston in a disengagement direction to cancel the engaged state of the friction plate;

an oil pump that is driven by the engine and delivers hydraulic oil to the friction engagement mechanism for moving the hydraulic piston in the engagement direction or the disengagement direction; and

an input clutch that is provided in the power transmission path and is switched to a disengaged state that disconnects the power transmission path or to an engaged state that connects the power transmission path on the basis of a shift operation performed by a driver,

wherein a biasing unit for biasing the hydraulic piston toward an engagement direction is provided in the friction engagement mechanism to hold the friction engagement mechanism in a slipping state or an engaged state during an engine shutdown that causes the oil pump to be deactivated, and

wherein the input clutch is switched to a disengaged state when a neutral position is selected, thereby disconnecting the engine from the drive wheel even during an engine shutdown that causes the friction engagement mechanism to be put into a slipping state or an engaged state.

2. The drive device for a vehicle according to claim 1, wherein the input clutch is a dog clutch.

3. The drive device for a vehicle according to claim 1, further comprising:

an input clutch mechanism that is disposed in the power transmission path and has an electromagnetic drive, and is switched to an engaged state in which the power transmission path is connected when the electromagnetic drive is energized and is switched to a disengaged state in which the power transmission path is disconnected when the electromagnetic drive is de-energized; and

an input clutch control unit that puts the electromagnetic drive into an energized state or a non-energized state on the basis of a shift operation performed by a driver,

wherein, if a neutral position is selected when a vehicle is in an activated state in which an activation switch is activated, the input clutch control means puts the electromagnetic drive into a de-energized state, thereby switching the input clutch mechanism to a disengaged state, and

wherein, if a vehicle is in a deactivated state in which the activation switch is deactivated, the deactivation of the activation switch causes the electromagnetic drive to be put into a de-energized state, thereby switching the input clutch mechanism to a disengaged state.

4. The drive device for a vehicle according to claim 2, further comprising:

a manual shift control that is shifted to a drive range when power is transmitted to a drive wheel and is shifted to a non-drive range when transmission of power to the drive wheel is cancelled,

wherein the dog clutch is connected to the manual shift control, and the engine and the drive wheel are separated from each other when the non-drive range is selected by a driver during an engine shutdown which causes the friction engagement mechanism to be put into a slipping state or an engaged state.

5. The drive device for a vehicle according to claim 4,

wherein the dog clutch has a drive mating member and a driven mating member that faces the drive mating member, and has a rod member that pushes the driven mating member into the drive mating member in conjunction with the manual shift control, and

wherein the rod member has a distal end member and a proximal end member that is disposed coaxially with the distal end member with a buffering member therebetween.

6. The drive device for a vehicle according to claim 5, wherein the rod member is pushed to a position at which the rod member comes into contact with the driven mating member when a forward drive range that is one type of the drive range is selected.

7. The drive device for a vehicle according to claim 6, wherein the dog clutch has the drive mating member and the driven mating member that faces the drive mating member, and an engagement oil chamber that urges the driven mating member toward the drive mating member is defined at a back side of the driven mating member.

8. The drive device for a vehicle according to claim 7, wherein hydraulic oil is delivered to the engagement oil chamber when a rearward drive range that is one type of the drive range is selected.

9. The drive device for a vehicle according to claim 8, wherein hydraulic oil is delivered to the engagement oil chamber when a forward drive range that is one type of the drive range is selected.

10. The drive device for a vehicle according to claim 9,

wherein the dog clutch has a drum member that is connected to a peripheral portion of the driven mating member with a spline connection therebetween,

wherein a pair of oil seals are provided at one end and the other end of the spline connection between the driven mating member and the drum member, and

wherein the engagement oil chamber is defined by the oil seals between the driven mating member and the drum member.

11. The drive device for a vehicle according to claim 4, further comprising a cam mechanism that is provided between the manual shift control and the dog clutch, and switches the dog clutch to a disengaged state when the manual shift control is shifted to a non-drive range and switches the dog clutch to an engaged state when the manual shift control is shifted to a drive range.

12. The drive device for a vehicle according to claim 11, wherein the cam mechanism has a cam that is rotated in conjunction with the manual shift control, and the cam has a plurality of projections on a profile of the cam.

13. The drive device for a vehicle according to claim 12,

wherein the dog clutch has a drive mating member and a driven mating member that faces the drive mating member, and has a rod member that pushes the driven mating member into the drive mating member, and

wherein the rod member is pushed by one of the projections when the manual shift control is shifted to a forward drive range that is one type of the drive range and the rod member is pushed by the other of the projections when the manual shift control is shifted to a rearward drive range that is one type of the drive range.

14. The drive device for a vehicle according to claim 13, wherein the rod member has a distal end member and a proximal end member that is disposed coaxially with the distal end member with a buffering member therebetween.

15. The drive device for a vehicle according to claim 14, wherein the dog clutch has the drive mating member and the driven mating member that faces the drive mating member, and the engagement oil chamber that urges the driven mating member toward the drive mating member is defined at a back side of the driven mating member.

16. The drive device for a vehicle according to claim 15, wherein hydraulic oil is delivered to the engagement oil chamber when the manual shift control is shifted to a forward drive range or a rearward drive range which are types of the drive range.

17. The drive device for a vehicle according to claim 16,

wherein the dog clutch has a drum member that is connected to a peripheral portion of the driven mating member with a spline connection therebetween,

wherein a pair of oil seals is provided at one end and the other end of the spline connection between the driven mating member and the drum member, and

wherein the engagement oil chamber is defined by the oil seals between the driven mating member and the drum member.

18. The drive device for a vehicle according to claim 17, further comprising:

an actuator connected to the cam mechanism,

wherein switching of the dog clutch to an engaged state is assisted by the power of the actuator.

19. The drive device for a vehicle according to claim 4, further comprising an electric actuator that is connected to the dog clutch, and switches the dog clutch to a disengaged state when the manual shift control is shifted to a non-drive range and switches the dog clutch to an engaged state when the manual shift control is shifted to a drive range.

20. The drive device for a vehicle according to claim 19,

wherein the dog clutch has a drive mating member and a driven mating member that faces to the drive mating member, and has a rod member that is connected to the electric actuator and pushes the driven mating member into the drive mating member, and

wherein the rod member has a distal end member and a proximal end member that is disposed coaxially with the distal end member with a buffering member therebetween.

21. The drive device for a vehicle according to claim 20, wherein the electric actuator pushes the rod member to a position at which the rod member comes into contact with the driven mating member when a drive range is selected.

22. The drive device for a vehicle according to claim 21, wherein the electric actuator switches the dog clutch to a disengaged state when not energized.

23. The drive device for a vehicle according to claim 22, wherein the dog clutch has the drive mating member and the driven mating member that faces the drive mating member, and an engagement oil chamber that urges the driven mating member toward the drive mating member is defined at a back side of the driven mating member.

24. The drive device for a vehicle according to claim 23, wherein hydraulic oil is delivered to the engagement oil chamber when a drive range is selected.

25. The drive device for a vehicle according to claim 24,

wherein the dog clutch has a drum member that is connected to a peripheral portion of the driven mating member with a spline connection therebetween,

wherein a pair of oil seals is provided at one end and the other end of the spline connection between the driven mating member and the drum member, and

wherein the engagement oil chamber is defined by the oil seals between the driven mating member and the drum member.