JPH01195163A - Parking device of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To automatically enable parking lock even at the time of N-range operation by providing a pole adapted to engage with a cam of an operating lever of an automatic transmission to lock a parking gear, which can be freely urged to the parking gear side through a hydraulic pressing portion. CONSTITUTION:A cam 1 provided on a manual operating lever of an automatic transmission is capable of moving in a slide cylinder 2. At the time of P-range operation, the cam is engaged with the lower surface of a pole 3 to be moved upward, and engaged with a parking gear 4 to lock. A hydraulic pressing portion 10 is disposed at the lower position of the center of the pole 3. At the time of N-range operation, oil pressure from a pump 5 is supplied to an oil path L2 through a manual operating lever 30, and when governor pressure Pg is not input (at the time of stop), a selector valve 20 is moved upward to supply oil pressure to the hydraulic pressing portion 10, and the pole 3 is urged upward to lock. Thus, parking lock can be automatically done at the time of N-range operation as well as P-range operation. Further, during running of a vehicle, a valve for cutting off oil pressure to a servo mechanism is fitted so as to completely eliminate the risk of causing parking brake during running.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a parking device for an automatic transmission for a vehicle, and more particularly to a parking device that operates automatically even in a neutral range.

(Prior Art) There are two conventional parking devices for automatic transmissions for vehicles, such as those described in Japanese Patent Application Laid-Open No. 184021/1983. This conventional parking device has a structure as shown in FIG. 5, in which a cam 1 is connected to a manual lever on the driver's seat.

When this manual lever is shifted to the parking range, the cam 1 moves forward inside the cylinder 2 (towards the front in the drawing), engages with the lower end of the pawl 3, and lifts the pawl 3 upward. The pawl 3a was designed to mesh with the parking gear 4.

(Problem to be solved by the invention) However, in the conventional parking device as described above, the cam 1
and pawl 3 were designed to engage only in the parking range of the manual lever.1 For example, when the vehicle is stopped on a slope and the manual lever is set to neutral, the foot brake is applied to prevent the vehicle from moving forward or backward. or have to use the handbrake,
The operation was complicated, and this situation was also dangerous.

This invention has been made in order to eliminate the drawbacks of conventional parking devices as described above. That is, an object of the present invention is to provide a parking device for an automatic transmission for a vehicle that can automatically lock a parking gear not only when the manual lever is in the parking range but also when it is in neutral. Furthermore, in addition to the above object, it is an object of the present invention to provide a parking device in which there is no risk of the parking gear being accidentally locked even if the shift lever is placed in neutral while the vehicle is running.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a parking gear that rotates integrally with the output shaft and a pole rotatably supported at one end by rotating the pole. In a parking device for a vehicle automatic transmission that engages and locks a parking gear, a servo mechanism is attached to the pawl that is operated by hydraulic pressure to rotate the pawl in a direction in which it engages with the parking gear, and this servo mechanism has a neutral The vehicle is characterized in that it is connected to a manual valve of an automatic transmission that operates the servo mechanism in the direction of meshing the pawl and the parking gear when in this state.

Here, when the manual valve is in the neutral state, it is possible to output hydraulic pressure to the servo mechanism to operate the servo mechanism in a direction to engage the pawl and the parking gear. At this time, it is preferable to connect a valve between the servo mechanism and the manual valve that shuts off hydraulic pressure from the manual valve when the vehicle speed is higher than a predetermined speed.

Further, the servo mechanism has two hydraulic chambers into which hydraulic pressure is introduced and each hydraulic pressure acts in opposite directions, and when the manual valve is in the neutral state, the hydraulic pressure in one hydraulic chamber of the servo mechanism is discharged, and the servo mechanism can be operated in the direction of meshing the pole and the parking gear. In this case, it is preferable to connect the servo mechanism with a valve that shuts off the hydraulic pressure to the hydraulic chamber that urges the servo mechanism in a direction to engage the pawl and the parking gear when the vehicle speed is higher than a predetermined speed.

(Function) When the manual lever of the automatic transmission is shifted to the parking range, the parking device of the automatic transmission for a vehicle is configured to shift the parking range by a cam mechanism mechanically or electrically connected to the manual lever. is rotated and engaged with the parking gear, but also when the manual lever of the automatic transmission is placed in neutral, that is, when the manual valve of the automatic transmission is in the neutral state, the hydraulic pressure by this manual valve is A servo mechanism is operated by the control, and the pole is rotated and engaged with the parking gear.

For example, by outputting hydraulic pressure to a servo mechanism when a manual valve is in the neutral state.

A servo mechanism is operated in a direction to engage the pole with the parking gear. At this time, if a valve is connected between the servo mechanism and the manual valve that cuts off hydraulic pressure from the manual valve when the vehicle speed is higher than a predetermined speed, the manual valve will be in neutral when the vehicle is running. Even in this state, the servo mechanism does not operate and the pole and parking gear do not mesh.

Also, for example, if the servo mechanism has two hydraulic chambers each receiving hydraulic pressure and each hydraulic pressure acting in opposite directions, when the manual valve is in the neutral state, the hydraulic pressure in one hydraulic chamber of the servo mechanism is discharged. As a result, the servo mechanism is operated by the hydraulic pressure in the other hydraulic chamber in a direction to engage the pawl and the parking gear. At this time, if the servo mechanism is connected to a valve that shuts off the hydraulic pressure to the hydraulic chamber that biases the servo mechanism in the direction of meshing the pole and the parking gear when the vehicle speed is higher than a predetermined speed. When the vehicle is running, the servo mechanism does not operate even if the manual valve is in the neutral state, and the pole and parking gear do not engage.

(Example) This invention will be described in more detail below based on an example shown in nine drawings.

In FIGS. 1 and 2, a servo mechanism 10 for biasing the pawl 3 to rotate in the direction of the parking gear 4 is installed at a lower position approximately at the center of the pawl 3.

This servo mechanism lO has a piston 12 in a cylinder l.
can be inserted and slid freely.

A rod 1 integrally installed in the center of this piston 12
The tip of the pole 3 passes through the upper end wall of the cylinder 11.
is in contact with the bottom of the A spring 14 is interposed between the piston 12 and the upper end wall of the cylinder in the cylinder 11, and urges the piston 12 and rod 13 in a direction away from the parking gear 4. Note that an O-ring 12a is attached to the outer circumferential portion of the piston 12 to maintain airtightness between the piston 12 and the inner circumferential wall of the cylinder 11.

The lower end wall of the cylinder 11 is constructed by fitting a plate lla and fixing the outer side with a snap ring llb, and the snap ring tic attached to the outer periphery of the plate lla provides an airtight seal with the inner circumferential wall of the cylinder. gender is preserved.

A hydraulic chamber 10A formed between the piston 12 and the lower end wall (plate 1la) of the cylinder 11
There is a port lid formed on the outer peripheral wall of the cylinder 11.
One end of the oil passage Ll is connected through the oil passage L.
The other end of 1 is the servo connection port 20a of the switching valve 20
It is connected to the.

This switching valve 20 is configured such that a governor pressure Pg is introduced into a chamber 20B formed at the upper end side of the spool 20A in the drawing through a port 20b, and the governor pressure Pg is
When g is low and the spool 20A is biased by the spring 20C and is in the upper position (left side position in the drawing), the servo connection port 20a.

The input port 20c is connected to the servo port 30a of the manual valve 30 via the oil passage L2. Also, governor pressure Pg from port 20b
becomes higher and the spool 20A is slid to the lower position (right side position in the drawing) against the spring 20C.
Communication between the servo connection port 20a and the human power port 20C is cut off by the land 20D, and the servo connection port 20a is connected to the drain port 20d instead.

The servo port 30a of the manual valve 30 is.

When the manual valve 30 is in the neutral position, it is communicated with the line pressure input port 30d via port 30b, oil path L3, and port aOC. Also, when the manual valve 30 is located at a position other than the neutral position, the servo port 30a is connected to the spool 30.
Communication with the port 30b is cut off by the land 30B or 30C of A, and communication is communicated with the drain port 30e. In addition, 5 is a boil pump,
6 is a strainer, and 7 is an oil pan.

In the above parking device, when the manual lever on the driver's seat is shifted to the parking range, the manual shaft 8 connected to the manual lever via a link is activated.
is rotated, and the detent lever 9 is accordingly rotated from the position shown in FIG. 1 to the parking position. As a result, the cam 1 moves forward while being guided within the cylinder 2 and engages with the lower part of the pawl 3.As the cam 1 moves forward, the pawl 3 rotates in the direction of the parking gear 4, and the pawl 3a moves toward the parking gear. 4 and locks the parking gear 4. In addition, when the manual lever is in a position other than the parking range, cam 1 will move to pole 3.
located at a distance from

When the manual lever is shifted to the neutral position, the spool 30A of the manual valve 30 connected to the manual lever is positioned at the position shown in FIG.
The line pressure PL introduced into d is the boat 30c-oil line L3.
- Boat 30b - Output to oil path L2 via servo port 30a.

Line pressure PL output from this manual valve 30
is input from the oil path L2 to the input port 20c of the switching valve 2o, but when the vehicle is running and the governor pressure Pg is input to the boat 20b from the governor valve (not shown), the spool 20A resists the spring 20C. (As shown on the right side of the figure, the input port 20c and the servo connection boat 20a are cut off by the land 20D. Therefore, the line pressure PL is not output from the servo connection port 20a, and the servo mechanism 10 does not operate. .At this time, the servo connection port 20a is connected to the drain boat 2.
It communicates with 0d.

However, the vehicle was stopped and the switching valve 2o was switched to boat 2.
When the governor pressure Pg is not input to 0b, the spool 2OA is in the raised position (the state on the left side of the drawing) by the spring 20C, and the input port 20c and the servo connection port 20a are in communication.

Therefore, the line pressure Pt introduced into the input port 20c.

is servo connection port 20a-oil line Ll-boat lid
is introduced into the hydraulic chamber 10A of the servo mechanism 10 through the piston 12, and pushes up the piston 12. As a result, the rod 13 protrudes from the upper end wall of the cylinder 11, presses the lower part of the pawl 3, rotates it in the direction of the parking gear 4, engages the pawl 3a of the pawl 3 with the parking gear 4, and causes the pawl 3 to rotate toward the parking gear 4.
lock.

When the manual lever 3o is shifted from the neutral position to another range from this state, the manual valve 3o
The spool 30A of No. 0 is slid from the state shown in FIG.
will be communicated to. As a result, the oil pressure in the hydraulic chamber 10A of the servo mechanism IO is changed from the boat 1id to the oil passage Ll to the servo connection port 20a of the switching valve 2o to the human power port 20c.
- Oil path L2 - Servo boat 3 of manual valve 30
The piston I2 and the rod 13 descend to the parking gear 4.
The engagement between the pawl 3 and the pawl 3a is released.

FIG. 3 shows another embodiment of the present invention, in which a solenoid valve 40 is connected between the manual valve 30 and the servo machine 6110 instead of the switching valve 2o of the previous embodiment. And this solenoid valve 40 is
The vehicle speed sensor 41 is turned on and off by a signal from the CPU 42 connected to it, and when the vehicle speed sensor 41 detects that the vehicle is running at a predetermined speed or higher.

The CPU 42 turns on and opens the solenoid valve 40,
The hydraulic pressure in the oil passage L2 is discharged. Therefore, even if the manual valve 80 is in the neutral position and the line pressure Pt is output from the servo boat 30a to the oil path L2, this line pressure PL is discharged from the solenoid valve 40, so the servo mechanism 10 cannot operate. There isn't.

Furthermore, when the vehicle is stopped and the vehicle speed is not detected by the vehicle speed sensor 41, the solenoid valve 40 is closed in an OFF state, and the line pressure P is output from the manual valve 30 in the neutral position to the oil path L1.
L is connected to the hydraulic chamber 10 via the oil passage L1 and port 11a.
A, and as a result, the servo mechanism 10 is activated and the parking gear 4 is locked, as in the previous embodiment.

FIG. 4 shows still another embodiment of the present invention, in which the first hydraulic chamber 100A formed between the piston 120 of the servo mechanism 100 and the lower end wall of the cylinder 110 is It is connected to the pump 5 via the port 110a and the oil path LIO.

Further, the second hydraulic chamber 100B formed between the piston 120 and the upper end wall of the cylinder 110 is connected to the drive port 130a and reverse port 130b of the manual valve 130 via the oil passage Lll and the check valve 200.
It is connected to the. The drive port 130a and the reverse port 130b are connected to the manual valve 130.
drain port 130c and drain port 130d, respectively, when the spool 130A is in the neutral position.
It is designed to be communicated with.

In this embodiment, when the manual valve 130 is in a range other than neutral, the line pressure Pt introduced into the manual valve 130 from the pump 5 via the oil path L12 and the port 130e is applied to the drive port 130a or the reverse port. 130b, check valve 200 - oil path L11 - port 11
0b into the second hydraulic chamber 100B. Therefore, the oil pressure in the second hydraulic chamber 100B is from the pump 5 to the oil path L10.
- In order to balance the hydraulic pressure introduced into the first hydraulic chamber 100A via the boat 110a, the piston 120 is pushed down by the spring 140, and the parking gear 4 is not locked by the pawl 3.

When the manual valve 130 is in the neutral state, the drive port 130a communicates with the drain port 130c, the reverse port 130b communicates with the drain port 130d, and the hydraulic pressure in the second hydraulic chamber 100B is transferred from the port 110b to the oil passage Lll to the check valve. 200-
Drive port 130a or reverse port 130b
- drained via drain port 130c or 130d; As a result, the piston 1 of the servo mechanism 100
20 is lifted by the hydraulic pressure in the first hydraulic chamber 100A, the rod 130 protrudes, and the pawl 3a of the pawl 3 is engaged with the parking gear 4. Note that when the manual valve 130 is shifted from this neutral state to another range, the drive port 130a or reverse port 1
Line pressure Pt is again introduced from 30b into the second hydraulic chamber 100B of the servo mechanism 100, the piston 120 is pushed down, and the parking gear 4 is unlocked.

In the embodiment shown in FIG. 4 above, the oil passage LIO connecting the pump 5 and the first hydraulic chamber 100A of the servo mechanism
A switching valve that is switched by the governor pressure Pg similar to the embodiment shown in FIG. 2 or a solenoid valve that is controlled on and off based on a signal from a vehicle speed sensor similar to the embodiment shown in FIG. 3 is connected to the switching valve. As a result, when the vehicle is running at a predetermined speed or higher, as in each of the embodiments described above, the servo mechanism 100 is not activated and the parking gear 4 is not locked even if the manual valve 130 becomes neutral. You can do it like this.

In addition, in each of the embodiments described so far, the servo mechanism has been arranged at approximately the center of the pole, but as shown by the broken line in FIG. You can also do it. This makes the stroke of the piston longer than when the servo mechanism is placed in the center of the pole, but the pole can be rotated with a small amount of hydraulic pressure.

(Effects of the Invention) As described above, in the present invention, the parking brake operates not only when the automatic transmission is shifted to the parking range but also when the automatic transmission is in the neutral state. Safety is improved by eliminating the need for a foot brake or handbrake even in situations such as

It was also considered to attach a hydraulic brake to the output shaft that operates when the vehicle is in neutral, but in this case there was a risk that the brake would be applied when the vehicle entered neutral while driving. In the present invention, while the vehicle is running, the rotation speed of the parking gear is faster than the speed at which the pole enters the trough of the parking gear, so the pole cannot be caught in the parking gear and is repelled, so that the pole cannot be set in neutral while the vehicle is running. Even if this happens, there is no risk of a braking phenomenon occurring.

Furthermore, by installing a valve that shuts off hydraulic pressure to the servo mechanism while the vehicle is running, there is no risk of the parking brake being applied while the vehicle is running.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the present invention, FIG. 2 is a sectional view showing the same embodiment together with a hydraulic circuit, and FIG. 3 is a sectional view showing another embodiment of the present invention together with a hydraulic circuit. FIG. 4 is a sectional view showing still another embodiment of the present invention, and FIG. 5 is a sectional view showing a conventional example. 3...Paul. 4...Parking gear. 5...Oil pump. to, tto...servo mechanism. 20...Switching valve. 30, 130...Manual valve. 40...Solenoid valve. 41...Vehicle speed sensor. 100 A...1st hydraulic chamber. 100 B...Second hydraulic chamber.

Claims (5)

[Claims] 1. A parking device for an automatic transmission for a vehicle in which a parking gear that rotates integrally with an output shaft and a pole rotatably supported at one end are engaged with each other by rotating the pole to lock the parking gear. A servo mechanism is attached to the servo mechanism that is operated by hydraulic pressure to rotate the pawl in the direction of meshing with the parking gear, and the servo mechanism is equipped with an automatic transmission that operates the servo mechanism in the direction of meshing the pawl and the parking gear when the servo mechanism is in a neutral state. A parking device for an automatic transmission for a vehicle, characterized in that it is connected to a manual valve for the vehicle. 2. When the manual valve is in the neutral state,
2. The parking device for an automatic transmission for a vehicle according to claim 1, wherein a hydraulic pressure is outputted to the servo mechanism to operate the servo mechanism in a direction to engage the pawl and the parking gear. 3. 3. A parking device for an automatic transmission for a vehicle according to claim 2, further comprising a valve connected between the servo mechanism and the manual valve to shut off hydraulic pressure from the manual valve when the vehicle speed is higher than a predetermined speed. 4. The servo mechanism has two hydraulic chambers into which hydraulic pressure is introduced and each hydraulic pressure acts in opposite directions, and when the manual valve is in the neutral state, the hydraulic pressure in one hydraulic chamber of the servo mechanism is discharged to pole the servo mechanism. 2. The parking device for an automatic transmission for a vehicle according to claim 1, wherein the parking device is operated in a direction in which the parking gear and the parking gear are engaged with each other. 5. 5. The automatic transmission for a vehicle according to claim 4, wherein the servo mechanism is connected to a valve that shuts off hydraulic pressure to the hydraulic chamber that urges the servo mechanism in a direction to engage the pawl and the parking gear when the vehicle speed is higher than a predetermined speed. Machine parking device.