JP2591602Y2 - Vehicle parking device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parking device for applying a brake when an automobile stops.

[0002]

2. Description of the Related Art A conventional parking device is disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 60-139666, a parking gear attached to an output shaft, a parking pawl engaged with and disengaged from the parking gear, and a parking pawl. And an operating shaft provided with a cylindrical cam in a direction to engage with the parking gear.

[0003]

SUMMARY OF THE INVENTION In the above-mentioned conventional apparatus,
Especially, in the case of medium-sized and large vehicles, there is a problem in that the operation force for releasing the parking, which releases the contact of the cylindrical cam that is in pressure contact with the parking pawl, is heavy. When the shaft moves in the direction, the parking pole or the parking gear may be damaged.

[0004] An object of the present invention is to provide a vehicle parking device which solves the above-mentioned conventional problems.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above objects, the present invention is characterized by a parking gear mounted on an output shaft, a parking pawl engaged with and disengaged from the parking gear, and a parking pawl. A parking shaft for a vehicle, comprising a cam that operates in a direction that engages with the parking gear, and an operating shaft that moves forward and backward by a shift lever, wherein a piston fixed to the operating shaft;
A fluid pressure supply passage for supplying fluid to the pressure chamber so as to press the piston to urge the operating shaft in the parking releasing direction when parking is released, and to close the fluid supply passage during parking operation by axial movement of the operating shaft. A reaction pressure chamber for providing a fluid pressure cylinder having a built-in valve body that opens when parking is released on the operating shaft and supplying fluid pressure to a tip of the operating shaft to restrain axial movement of the operating shaft in the parking operation direction; And a control valve that leaks the fluid pressure of the reaction force chamber to the low pressure side and reduces the pressure as the traveling speed of the vehicle decreases.

[0006]

According to the above construction, the valve body closes the fluid supply passage by the axial movement of the operating shaft during the parking operation, the pressing force of the piston in the parking releasing direction is reduced to zero, and the parking operation is performed smoothly. The fluid supply passage is opened to press the piston in the parking release direction, and to provide an assisting action to the operating shaft to reduce the parking release operation force. In addition, during traveling with the parking released, fluid pressure is supplied to the reaction force chamber at the tip of the operating shaft, thereby restricting the axial movement of the operating shaft in the parking operation direction.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an output shaft of a transmission, to which a parking gear 2 is attached. 3
Reference numeral denotes a parking pawl which is engaged with and disengaged from the parking gear 2, and is pivotally supported on a casing (not shown) so as to be able to pivot vertically about a support shaft 4.

[0008] 5 is a operating shaft, it is connected via the shift lever 6 and the wire 7, in which in the figure by the operation of the shift lever 6 carries out an axial movement of the retraction of the forward and rightward leftward. A cam 8 for rotating the parking pawl 3 in the direction of the parking gear 2 is fixed to the operating shaft 5.

A hydraulic cylinder 9 is provided on the operating shaft 5. A piston 11 fixed to the operating shaft 5 is provided in the hydraulic cylinder 5. Fluid supply passage 2 that supplies fluid to pressure chamber 23 so as to urge valve 5 in the parking release direction.
1 and a valve element 14 that closes the fluid supply passage 21 during parking operation by axial movement of the operating shaft 5 and opens when parking is released.

The construction of the hydraulic cylinder 9 will be described in more detail. The pressure chamber 23 is formed by the piston 11 fixed to the operating shaft 5 as described above,
In order to supply the fluid pressure to the pressure chamber 3, an introduction port 18 connected to the fluid pressure tank 17 by a pipeline, an outlet port 19, and a fluid supply passage 21 communicating from the outlet port 19 to the supply port 20 of the pressure chamber 23 And a discharge port 22 for discharging the fluid pressure in the pressure chamber 23.

The valve structure which closes the fluid supply passage 21 at the time of the parking operation and opens at the time of parking release has a valve body 14 having a valve seat of a tapered hole 15 formed between the introduction port 18 and the exit port 19. Is slidably fitted to the operating shaft 5 with its retreating end regulated by a stopper 16, and a tapered shaft portion 13 that contacts the tapered hole 15 of the valve body 14 is formed on the operating shaft 5. Reference numeral 12 denotes a seal portion facing the front surface of the valve element 14.

A reaction chamber 30 is provided at the tip of the operating shaft 5,
The reaction chamber 30 is supplied with a constant fluid pressure by a first pump 31. The reaction force chamber 30 has a discharge passage 32 for leaking fluid pressure to the low pressure side. The discharge passage 32 leaks the fluid pressure of the reaction force chamber 30 to the low pressure side as the traveling speed of the vehicle decreases. A control valve 37 for reducing the pressure is provided.

The control valve 37 comprises a ball valve 33 which opens and closes the discharge passage 32, and a plunger 34 which retreats by a spring 35, moves forward by fluid pressure and presses the ball valve 33 in a closing direction. , A second pump 36 for applying a fluid pressure to the plunger 34.

The first pump 31 is operated by a crankshaft of the engine, and a fluid pressure is always supplied to the reaction force chamber 30 when the engine is rotating. The second pump 3
6 is operated by the output shaft of the transmission, the output pressure of which is lower than the output pressure of the first pump 31 by the spring 3.
5 is set higher by the amount of the compression action force.

The operation of the parking device having the above configuration will be described. In the parking operation, the operating shaft 5 is axially moved rightward in the figure by moving the shift lever 6 in the P direction, and the cam 8 pushes the parking pole 3 downward.
And engages with the parking gear 2 to restrict the rotation of the output shaft 1.

At this time, the tapered shaft portion 13 comes into close contact with the tapered hole 15 of the valve body 14 by the axial movement of the operating shaft 5 to the right, so that the passage between the inlet port 18 and the outlet port 19 is closed. The supply of the fluid pressure is shut off.

To release the parking operation, the shift lever 6 is moved in the R direction. When the shift lever 6 is slightly moved in the R direction, the tapered shaft 13 separates from the tapered hole 15 of the valve body 14 and a gap is formed between the tapered shaft portion 13 and the tapered hole 15. The ports 19 communicate with each other, and the fluid pressure in the fluid pressure tank 17 flows from the inlet port 18 to the outlet port 19.

The fluid pressure led out from the outlet port 19 is supplied to the pressure chamber 23 through the fluid pressure supply passage 21 and pushes the piston 11 leftward in the drawing, and this pushing force is assisted by the operating shaft 5, and Reduce the operating force of parking release.

[0019] The parking pawl 3 and the detaching cam 8 from the parking pawl 3 by the left-axis movement of the operating shaft 5 pivots upward direction by a return spring, to liberation engagement from the parking gear 2. At this time, the valve element 14 closes the inlet port 18 and the outlet port 19 on its outer diameter surface,
Also, the discharge port 2 closed by the piston 11
2 is opened to discharge the fluid pressure supplied into the pressure chamber 23.

A constant pressure fluid pressure is always supplied from the first pump 31 to the reaction chamber 30 at the tip of the operating shaft 5 when the engine is rotating, but the second pump 36 when the vehicle is stopped. Is not operated, the plunger 34 moves backward by the spring 35, and the ball valve 33 opens the discharge passage 32. Therefore, the fluid pressure supplied to the reaction force chamber 30 is released to the low pressure side, and does not restrict the axial movement of the operating shaft 5 in the parking operation direction.
Parking operation can be performed smoothly.

When the second pump 36 is operated by running of the vehicle, the plunger 34 is pushed forward by the output pressure thereof and moves forward, pushing the ball valve 33 in the closing direction to push the discharge passage 3.
2 is closed. As a result, the pressure inside the reaction force chamber 30 becomes a predetermined pressure, and restrains the axial movement of the operating shaft 5 that has been released in the parking operation direction. Accordingly, the shift lever 6 is prevented from being erroneously moved to the parking range during traveling, and the parking pole or the parking gear is prevented from being damaged.

[0022]

As described above, according to the present invention, a hydraulic cylinder is provided on an operating shaft which is provided with a cam which operates in a direction in which a parking pawl is engaged with a parking gear and which is moved forward and backward by a shift lever. In the cylinder, a piston fixed to the operating shaft, a fluid pressure supply passage for supplying fluid to the pressure chamber to press the piston at the time of parking release and urge the operating shaft in the parking release direction,
A valve body that closes the fluid supply passage during parking operation by axial movement of the operating shaft and opens when parking is released, and supplies fluid pressure to the tip of the operating shaft to move the operating shaft in the parking operation direction; Is provided with a control valve that reduces the fluid pressure of the reaction chamber to the low pressure side and reduces the pressure as the traveling speed of the vehicle decreases, and releases parking from the parking operation state. When the operating shaft moves, the valve body is opened and the hydraulic cylinder assists the operating shaft, reducing the operating force for parking release, and accidentally moving the shift lever to the parking range during traveling to park. This has the effect of preventing a problem such as damaging the pawl or the parking gear.

[Brief description of the drawings]

FIG. 1 is a sectional view of the present invention.

[Explanation of symbols]

 Reference Signs List 1 output shaft 2 parking gear 3 parking pole 5 operating shaft 6 shift lever 8 cam 9 fluid pressure cylinder 11 piston 13 taper shaft portion 14 valve body 15 taper hole 17 fluid pressure tank 18 introduction port 19 outlet port 20 supply port 21 fluid pressure supply Passage 22 Discharge port 23 Pressure chamber 30 Reaction chamber 31 First pump 32 Discharge passage 36 Second pump 37 Control valve

Claims (1)

(57) [Scope of request for utility model registration] A parking gear attached to an output shaft, a parking pawl engaged with and disengaged from the parking gear, and a cam that operates in a direction to engage the parking pawl with the parking gear; In a vehicle parking device comprising an operating shaft, a piston fixed to the operating shaft and a fluid supplied to a pressure chamber so as to urge the operating shaft in the parking releasing direction by pressing the piston when parking is released. A fluid pressure cylinder including a fluid pressure supply passage and a valve body that closes the fluid supply passage during parking operation by axial movement of the operation shaft and opens when parking is released is provided on the operation shaft, and a tip of the operation shaft is provided. A reaction force chamber for supplying fluid pressure to the shaft to restrict the axial movement of the operating shaft in the parking operation direction,
A parking device for a vehicle, comprising: a control valve that leaks fluid pressure in the reaction force chamber to a low pressure side and reduces the pressure as the traveling speed of the vehicle decreases.