JP2000074211A - Parking device for automatic transmission - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a parking device for an automatic transmission capable of performing range switching requiring a large force without giving a driver an uncomfortable feeling with a simple structure. When a shift-by-wire operation detects at least one of an operation of a shift lever to a parking position and an operation from a parking position, the motor drive power at the time of the switching is detected. By providing a motor control means which is larger than that at the time of switching which does not include the parking position, range switching including a parking range position requiring a large force can be performed without using a gear mechanism having a large reduction ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a parking device for an automatic transmission.

[0002]

2. Description of the Related Art In an automatic transmission mounted on a vehicle, a position of a shift lever is detected by a sensor, and a motor is controlled and driven in accordance with the detection signal to obtain "P (parking)" and "R (rebus)". , "N (neutral)", "D (drive)", and so on, so-called shift-by-wire is being promoted.

Incidentally, the automatic transmission is provided with a parking device for mechanically locking the drive wheels so that the vehicle does not move when the shift lever is operated to the parking range position.

[0004] In the shift-by-wire system, a parking pawl (lock mechanism) is driven by a motor or the like via a cam or the like to switch the range, and the parking pawl is disengaged from a parking gear connected to driving wheels. Used. When the convex portion of the parking pawl is fitted to the parking gear by driving the motor (forward rotation), the driving wheels are locked (rotation is restricted), and the driving of the motor (reverse rotation) causes the parking pawl fitted to the parking gear to rotate. When the projection is removed, the drive wheel is unlocked (rotation is permitted).

By the way, when the driving wheels are locked, the parking pawl is hardly disengaged from the parking gear due to the reaction force applied from the driving wheels. Particularly when the vehicle is parked on a slope or the like, the reaction force is large (because the vehicle weight is added).

For this reason, the parking device is required to have the ability to overcome this reaction force and to separate the parking pawl from the parking gear. Therefore, conventionally, Japanese Unexamined Patent Publication No.
As disclosed in JP-A-310820, a reduction mechanism having a pair of large and small gears having a large reduction ratio is provided on the output shaft of the motor, and the structure of this reduction mechanism is from a parking range position to a reverse range position. (When the parking pawl is disengaged from the parking gear by adopting a gear structure in which the pair of large and small gears mesh with each other only when switching from the reversing range position to the parking range position) a large torque to overcome the reaction force It has been proposed that the parking pawl be driven by the vehicle.

[0007]

Incidentally, the parking device is required to have a structure as simple as possible from the viewpoint of miniaturization and the like. However, the conventional structure described above
The parking device has a complicated structure because a dedicated gear mechanism having a large gear ratio is provided only to separate the parking pawl from the parking gear.

For this reason, the parking device tends to be large. In addition, the operating speed when switching from the parking range position to the reverse range position (the same applies from the reverse range position to the parking range position) is switched to another range position by being reduced at a large reduction ratio (the reverse range position and the neutral position). The operation speed is considerably slower than the operation speed at the time of switching between the range position and the switching between the neutral range position and the drive range position, so that the driver feels strange.

Therefore, there is a demand for an improvement in the parking device in such a point. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the simple structure, and furthermore, without causing a sense of incongruity to a driver, an automatic switching that requires a large force and enables a range switching. A parking device for a transmission is provided.

[0010]

According to a first aspect of the present invention, there is provided a parking device, wherein at least one of an operation of a shift lever to a parking position or an operation from a parking position is detected. A motor control means is provided for increasing the motor drive power at the time of the switching as compared with the switching not including the parking position.

As a result, the range can be switched from the parking range position requiring a large force without using a gear mechanism having a large reduction ratio. Therefore, the configuration of the parking device is simplified, and the device can be downsized. Moreover,
Since the power supplied to the motor is increased, the operating speed for switching from the parking range position to the reverse range position can be substantially the same as the operating speed when switching to another range position, and the operating speed between each range position is substantially constant. , So that the driver does not feel uncomfortable.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on one embodiment shown in FIGS. FIG. 1 shows a parking device incorporated in an operation drive system of a vehicular automatic transmission. In the figure, reference numeral 1 denotes a range switching motor. A control shaft 3 having a detent plate 2 is connected to an output shaft (not shown) of the motor 1. The detent plate 2 is connected with an advance / retreat shaft 4 connected to a manual valve in a hydraulic circuit (not shown) via a pin 4a, and operates the manual valve in accordance with the operation of the motor 1 to change the speed to "N (neutral). ), D (drive), etc. are performed.

On the upper edge of the detent plate 2,
The tip of the detent spring 5 is elastically pressed. The leading end of the detent spring 5 engages with a detent groove 6 for positioning the range formed in the upper edge of the detent plate 2, and each range of the automatic transmission, “P (parking)”, “R” (reverse)",
Each range position such as "N (neutral)" or "D (drive)" is positioned. Further, for example, the detent plate 2 is provided with a real position sensor 7 for detecting each range position.

A parking rod 9 is connected to the detent plate 2 and extends, for example, below a parking gear 8 (a gear directly connected to an output shaft of an automatic transmission, not shown) along the axial direction. The parking rod 9 has an L-shape so as to move forward and backward along the axial direction of the parking gear 8 by the movement of the detent plate 2. A parking lock cam 10 and a compression spring 11 for urging the lock cam 10 are attached to the parking rod 9. Above the parking lock cam 10, a parking pawl 12 which is driven vertically by the movement of the parking lock cam 10 is provided, and these constitute a lock mechanism A. The parking pawl 12 is rotatably supported on one side by a support shaft 13, and is pushed up by the movement of the parking lock cam 10, and the pushing up is released. On the upper portion of the parking pawl 12, a convex portion 14 is formed which can be inserted into a concave portion 8a between the teeth of the parking gear 8, and when the parking pawl 12 is pushed up by the parking lock cam 10, the parking pawl 12
The convex portion 14 is fitted in the concave portion 8a nearest to the parking gear 8, and when the push-up by the parking lock cam 10 is released, the convex portion 14 comes off from the concave portion.

Reference numeral 15 denotes a shift device having a shift lever 15a for switching each range (P, R, N, D). The shift device 15 is provided with a shift position detection sensor 16 (corresponding to position detection means) for detecting the shift position of the shift lever 15a.

Reference numeral 17 denotes a control unit (corresponding to control means) constituted by using, for example, a microcomputer. The control unit 17 receives the signal from the shift position detection sensor 16 and the signal from the actual position sensor 7 and controls the motor 1 so as to switch to the range operated by the shift lever 15a.

The control unit 17
In addition, when switching from the “P” range position to the “R” range position, or when switching from the “R” range position to the “P” range position, which is a main part of the present invention, a large torque that overcomes the reaction force is applied to the motor itself. The control to generate is performed.

That is, the control unit 17 supplies both the motor power for the normal range switching suitable for range switching which does not require a large power and the motor power suitable for the range switching requiring a large power, for example. The obtained motor power supply variable section 18 is built in. Specifically, the motor power supply variable unit 18 converts the voltage of the battery mounted on the vehicle, for example, to a motor power supply voltage for normal range switching that does not require large power, for example, a motor having a voltage value of 0.1 V. Two types of power supply voltages are obtained: a power supply voltage and a voltage value higher than the voltage value, that is, a motor power supply voltage that generates a motor torque that overcomes the reaction force, for example, a motor power supply voltage that uses a battery voltage value (12 V) as it is. It is like that.

Further, based on the detection results of the actual position sensor 7 and the shift position detection sensor 16, the control unit 17 performs range switching requiring a large force, for example, "P".
Switching from the range position to the “R” range position or switching from the “R” range position to the “P” range position is detected.
A function is set in which the motor 1 is driven by a power supply of 2 V and the motor 1 is driven by a power supply of 0.1 V when the range is changed in other ranges.

With this function, a large torque is generated in the motor 1 only at the time of range switching requiring a large torque. This control is shown in the flowchart of FIG.

Referring now to the flowchart, it is assumed that the shift lever 15a has been shifted from the "N" range position to the "R" range position. At this time, the control unit 17 reads from the real position sensor 7 that the real motor position is in the “N” range position in step S1. In the following step S2, it is read from the shift position detection sensor 16 that the shift lever 15a has been operated to the "R" range position, which is the instruction lever position of the shift destination.

Then, the process proceeds to step S3, where the control unit 17 determines whether this range switching is a range switching requiring a large force, that is, "P → R, R →
It is determined whether or not the range is changed to "P".

Here, the current range switching is "N → R range switching" which requires only a small operating force to operate the manual valve in the hydraulic circuit. Therefore, step S
Proceed to 4. Then, a low-voltage (0.1 V) power supply voltage suitable for normal range switching is supplied to the motor 1 to drive the motor 1. Thereby, the control shaft 3
Is rotated to rotate the detent plate 2 against the locking force of the detent spring 5.

With the rotation of the detent plate 2,
A manual valve (both not shown) of the hydraulic circuit is operated via the reciprocating shaft 4 to start shifting in the “R” range.

The rotational displacement of the motor 1 is determined in the following step S
The reciprocating shaft 4 moves until the pointing lever position monitored by the actual position sensor 7 and detected by the actual position sensor 7 reaches (or approaches) the designated "R" range position.

When the vehicle reaches the designated destination and the detent spring 5 is locked in the detent groove 6 corresponding to the "R" range, the process proceeds to step S6, where the motor 1 is stopped (set to 0 V), and the "R" is set. Finish shifting the range.

This corresponds to “R → N”, “N → D”, “D →
The same applies to the range switching of "N". On the other hand, it is assumed that switching is performed from the “R” range to the “P” range in which the vehicle weight acts such as parking on a slope or the like.

At this time, the control unit 17
Reads from the actual position sensor 7 that the actual motor position is in the "R" range position in step S1, and in step S2, the shift lever 15a from the shift position detection sensor 16 is the instruction lever position of the shift destination. P "
It reads that the lever is operated to the range position.

Then, proceeding to step S3, the control unit 17 determines whether or not this range switching is a range switching requiring a large force. Here, the range switching is “R → P range switching” that requires a large operation force in some cases as described above.

Therefore, the process proceeds to step S7. Then, a high voltage (12 V) power supply voltage suitable for range switching requiring a large torque is supplied to the motor 1 to drive the motor 1.

As a result, the detent plate 2 rotates as in the case described above. This detent plate 2
With the rotation of the parking lock cam 10, the parking pawl 12 is pushed up by the parking lock cam 10, and the convex portion 14 is fitted into the concave portion 8a formed in the parking gear 8 with a large force. Thereby, even if the concave portion 8a of the parking gear 8 is located in a direction in which it is difficult to fit, the convex portion 14 can be reliably engaged with the parking gear 8.

The rotational displacement of the motor 1 is determined in the following step S
The parking lock 10 moves until the pointing lever position, which is monitored at 8 and detected by the actual position sensor 7, reaches the "P" range position as the pointing destination.

When the vehicle reaches the designated destination and the detent spring 5 is locked in the detent groove 6 corresponding to the "P" range, the process proceeds to step S6, where the motor 1 is stopped (set to 0 V), and the "P" Finish shifting the range. That is, the parking gear 8 is locked, restricts the rotation of the drive wheels of the vehicle, and prevents the vehicle from moving.

Further, range switching from the parking state in which the parking pawl 12 is strongly pressed against the parking lock cam 10 (by receiving a reaction force from the parking gear 8), that is, switching from the "P" range to the "R" range. Is performed.

At this time, the control unit 17
Reads from the actual position sensor 7 that the actual motor position is in the "P" range position in step S1, and in step S2, the shift lever 15a from the shift position detection sensor 16 is the instruction lever position of the shift destination. R "
It reads that the lever is operated to the range position.

Next, proceeding to step S3, the control unit 17 determines whether or not this range switching is a range switching requiring a large force. Here, this range switching is “P → R range switching” in which the parking lock cam 10 is hard to move due to the reaction force from the parking gear 8 and requires a large operating force.

Therefore, the process proceeds to step S7. Then, a high-voltage (12 V) power supply voltage suitable for range switching requiring a large torque as described above is supplied to the motor 1 to drive the motor 1.

As a result, the detent plate 2 rotates as described above. This detent plate 2
With the rotation of the parking rod 9, the parking rod 9 moves backward, and the parking lock cam 10 moves the parking pawl 1 with a large driving force.
2 is driven in a direction away from 2. As a result, the parking lock cam 10 comes out from below the parking pawl 12.

Here, the rotational displacement of the motor 1 is monitored in step S8 as described above, and the pointing lever position detected from the actual position sensor 7 is the "R" range position as the pointing destination. , The parking lock cam 10 moves.

By driving the motor with the high electric power, even if the parking pawl 12 is hard to be disengaged by the reaction force, the parking pawl 12 is moved by the parking gear 8.
To get out of

When the vehicle reaches the designated destination, the detent spring 5 is inserted into the detent groove 6 corresponding to the "R" range.
Is locked, the process proceeds to step S6, and the motor 1 stops (0 V).

As described above, when the range is switched from the "P" range position or when the range is switched to the "P" range position, the motor 1 is driven with a larger electric power than when other ranges are switched.
Is driven, a gear mechanism having a large reduction ratio as in the prior art is not required, the configuration of the parking device can be simplified, and the size of the parking device can be reduced. Moreover, the power supply to the motor 1 is divided by the load,
Since this is an increasing technology, the operating speed when switching from the “P” range position or when switching to the “P” range position is substantially the same as the operating speed when switching to another range position. The operation speed of the vehicle can be made substantially constant, so that the driver does not feel uncomfortable.

In the embodiment, an example in which a high power supply voltage is supplied to the motor has been described. However, the present invention is not limited to this example. Alternatively, a large torque may be generated from the motor.

Further, in one embodiment, the motor 1 is driven with a large power in both the range switching from the “P” range position and the range switching to the “P” range position. May be supplied with high power to the motor only when the range is switched from the “P” range position where is high.

Further, the example in which the parking gear is locked (restricted) using the lock mechanism for operating the parking pawl with the parking lock cam has been described. However, the present invention is not limited to this, and a structure in which the parking pawl is operated by another structure may be used. Absent.

[0046]

As described above, according to the first aspect of the present invention, at the time of range switching requiring a large force, the motor itself generates a large torque necessary for the range switching, so that the reduction ratio is large. Range switching requiring a large force can be performed without using a gear mechanism.

Therefore, the configuration of the parking device is simplified, and the device can be downsized. Moreover,
Since the power supplied to the motor is increased, the operating speed can be made almost the same as the operating speed for switching between other range positions even in range switching that requires a large amount of power, and the operating speed between each range position is almost constant. There is no discomfort.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating the structure of a parking device for an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining control for varying power supply power of a motor in the parking device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motor 7 ... Actual position sensor 8 ... Parking gear 9 ... Parking rod 10 ... Parking rod cam 12 ... Parking pawl 13 ... Support shaft 15a ... Shift lever 16 ... Shift position detection sensor (position detection means) 17 ... Control unit (control) means).

Claims (1)

[Claims] 1. A parking gear connected to a rotating member of an automatic transmission, a lock mechanism engaged with or released from the parking gear, and a lever position detecting means for detecting a shift lever position of the automatic transmission. Switching the range position of the automatic transmission according to the shift lever position, and engaging the lock mechanism with the parking gear when the shift lever is operated to the parking position to restrain rotation of the rotating member. An electric motor driven to release the lock mechanism from the parking gear when the shift lever is operated from the parking position to allow rotation of the rotating member; and operating the shift lever to the parking position. Or, when at least one of the operations from the parking position is detected, the motor drive at the time of the switching is performed. Parking device for an automatic transmission for a motor control unit that larger than a force upon switching which does not contain a park position, comprising the.