JP4968085B2 - Parking switching device - Google Patents

Description

  The present invention relates to a parking switching device mounted on an automatic transmission for a vehicle.

An automatic transmission for a vehicle is equipped with a shift range switching mechanism and a parking switching mechanism, and a driver manually switches the mechanism.
However, in recent years, as shown in FIG. 2, a shift range switching device (shift-by-wire: hereinafter referred to as SBW) that switches the shift range switching mechanism J1 and the parking switching mechanism 3 with a rotary actuator J2 equipped with an electric motor. (Refer to Patent Document 1, for example).

In the SBW, the manual actuator J3 for switching the shift range and the conical portion (cone) J4 for switching the parking range are driven and displaced by the rotary actuator J2.
Specifically, the SBW rotates and displaces a substantially fan-shaped detent plate J6 via a rod J5, and in conjunction with the detent plate J6, a manual valve J3 for switching the shift range and a conical portion J4 for switching the parking range. Are displaced in the axial direction.

On the other hand, as a near-future plan, means has been proposed in which a manual valve J3 for shift range switching is directly driven by an electromagnetic actuator or hydraulically switched by a pilot pressure or the like switched by an electromagnetic pilot valve.
Then, the drive mechanism of the shift range switching mechanism J1 is removed from the SBW, and the rotary actuator J2 drives only the parking switching mechanism 3.

  Here, the rotary actuator J2 has a structure in which the substantially fan-shaped detent plate J6 is rotated to displace the conical portion J4 in the axial direction, and the lock lever 2 is driven by a change in the outer peripheral surface of the conical portion J4. (I) The operation time from the lock (parking) to the unlock (parking release) becomes longer, and (ii) the operation time from the unlock to the lock becomes longer.

(Problem 1)
Since the parking release from the locked state to the unlocked state shown in (i) is surely executed at the driver's will, there is no problem in shortening the operation time.
On the other hand, when the operation time from unlocking to locking shown in (ii) is long, when the vehicle is parked in a place where the vehicle may move on its own such as a slope, the vehicle moves before the parking lock is applied, and the vehicle stops. The position may be shifted. Further, when the vehicle moves faster before parking lock is applied, such as when parking on a steep slope, the lock lever 2 is repelled by the rotation of the parking gear 1 in the automatic transmission, causing a problem that the parking lock cannot be performed. . For this reason, there exists a request | requirement which shortens the operation time from the unlocking of said (ii) to a lock | rock.
Therefore, it is conceivable to increase the responsiveness of the rotary actuator J2 and increase the moving speed of the conical portion J4. However, since the conventional structure reciprocates the conical portion J4 in the axial direction, it is locked from unlocking. It is difficult to switch from unlocking to locking in a short time.

(Problem 2)
Since the conventional SBW has a structure in which both the shift range switching mechanism J1 and the parking switching mechanism 3 are switched by a single rotary actuator J2 via a drive mechanism (rod J5, detent plate J6, etc.), the rotary actuator J2 There were great restrictions on the mounting position. That is, the mounting space for the rotary actuator J2 has many restrictions, and the mounting property is poor.
Specifically, it is necessary to mount the rotary actuator J2 outside the automatic transmission case, and it is difficult to mount the rotary actuator J2 inside the automatic transmission case.
JP 2004-052928 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a parking switching device capable of switching from unlocking to locking in a short time.

[Means of claim 1]
In the parking switching device employing the means of claim 1, when switching from unlocking to locking, the sliding contact position of the lock lever and the rotating cam is swirled from the maximum lift part of the spiral lift part via the release step part. The rotating cam is rotationally driven by the cam driving means so as to shift to the minimum lift portion of the shaped lift portion.
Thus, by driving the lock lever using the release step portion, switching from unlock to lock can be performed in a short time.
Specifically, by using the rotating cam release step when switching from unlocking to locking, the moving range (rotation angle) of the rotating cam required for switching from unlocking to locking can be reduced. Switching time from lock to lock can be shortened.

[Means of claim 2]
The cam driving means of the parking switching device employing the means of claim 2 is a rotary actuator using an electric motor. The rotary actuator is preferably a combination of an electric motor and a speed reducer that decelerates and outputs the rotation of the electric motor.
By driving the rotary cam with a dedicated rotary actuator, restrictions on the mounting position of the rotary actuator can be reduced, and the mountability of the rotary actuator can be improved. Further, since the mountability of the rotary actuator is enhanced, the rotary actuator can be mounted inside the automatic transmission case.

[Means of claim 3]
In the parking switching device employing the means of claim 3, the lock lever is driven by a cam surface provided on the rotating cam.
Specifically, on the outer peripheral surface of the rotating cam, the range of the spiral lift portion where the distance between the rotation center and the outer peripheral surface gradually increases toward a rotational direction in one direction starting from a predetermined rotation angle is 360 ° . It is provided over. In addition, the outer peripheral surface of the rotating cam has a rotation center between a maximum lift portion where the distance between the rotation center and the outer peripheral surface is maximum and a minimum lift portion where the distance between the rotation center and the outer peripheral surface is minimum. A release step portion is provided in which the distance from the outer peripheral surface is abruptly shortened. That is, the outer peripheral surface of the rotating cam is provided in the shape of a substantially cochlear shell as viewed from the axial direction.
On the other hand, the lock lever is provided at a rotation support portion that is rotatably supported by a fixing member (for example, an automatic transmission case), and a portion away from the rotation support portion, and is provided by a biasing force of a biasing means. A displacement drive unit that is pressed against the outer peripheral surface of the rotary cam. In addition, a convex part may be provided between a rotation support part and a displacement drive part, and a rotation support part may be provided between a convex part and a displacement drive part.
As the rotary cam rotates, the displacement driving portion of the lock lever is displaced along the outer peripheral surface of the rotary cam, so that the convex portion provided on the lock lever is displaced with respect to the parking gear.

A parking switching device of the best mode includes a parking gear provided on a drive shaft that always rotates in conjunction with a drive wheel of a vehicle, a lock lever having a convex portion that can be engaged with and disengaged from the parking gear, and the lock lever. And a parking switching mechanism for engaging and disengaging the convex portion with the parking gear.
The parking switching mechanism includes an urging unit that urges the lock lever toward a lock direction in which the convex portion meshes with the parking gear, a rotation cam that is rotationally driven in one direction and applies a displacement force to the lock lever, and the rotation cam. Cam drive means for rotationally driving the motor.
The rotating cam is driven to rotate in one direction by the cam driving means, so that the spiral lift portion that gradually separates the convex portion from the parking gear against the urging force and the convex portion is suddenly separated from the parking gear. And a release step portion to be released.
When switching from unlocking to locking, the sliding contact position of the lock lever and the rotating cam shifts from the maximum lift part of the spiral lift part to the minimum lift part of the spiral lift part via the release step part. As described above, the rotating cam is rotationally driven by the cam driving means.

An example of a parking switching device mounted on an automatic transmission for a vehicle will be described with reference to FIG.
An automatic transmission for a vehicle includes a hydraulic control circuit that performs shift control, and the hydraulic control circuit includes a manual valve that switches an oil passage according to a set state of a shift range. The manual valve of this embodiment is directly driven by a dedicated actuator (for example, a linear solenoid) or is hydraulically switched by a dedicated hydraulic pressure switching means (for example, a pilot hydraulic pressure controlled by an electromagnetic pilot valve).
That is, the manual valve of the hydraulic control circuit is independently driven by a drive means dedicated to the manual valve.

On the other hand, the automatic transmission is equipped with a parking switching device that locks or unlocks the drive shaft in the automatic transmission to lock and unlock the drive wheels of the vehicle.
This parking switching device includes a parking gear 1 provided on a driving shaft in an automatic transmission that always rotates in conjunction with a driving wheel of a vehicle, and a lock lever 2 having a convex portion 2a that can be engaged with and disengaged from the parking gear 1. And a parking switching mechanism 3 for driving the lock lever 2 to engage and disengage the convex portion 2a from the parking gear 1.
Here, as described above, the manual valve of the hydraulic control circuit is independently driven by the driving means dedicated to the manual valve. For this reason, the parking switching mechanism 3 is also independently driven by a driving means dedicated to the parking switching mechanism.

Specifically, the parking switching device includes a parking gear 1 provided on a drive shaft in an automatic transmission coupled to a drive shaft that always rotates in conjunction with a drive wheel of a vehicle, and a fixed member (such as an automatic transmission case). Is provided with a lock lever 2 rotatably supported within a predetermined rotation angle range, and the lock lever 2 is rotated by the parking switching mechanism 3 so that the recess 1a of the parking gear 1 and the protrusion of the lock lever 2 are The part 2a is engaged and disengaged, and the parking gear 1 is switched between locking and unlocking.
That is, the convex portion 2a of the lock lever 2 is engaged with the parking gear 1, so that the rotation of the parking gear 1 is restricted, and the drive wheels of the vehicle are locked via the drive shaft, the differential gear, etc. Is achieved. Conversely, when the convex portion 2a of the lock lever 2 is disengaged (disengaged) from the parking gear 1, the regulation of the rotation of the parking gear 1 is released, and the driving wheel of the vehicle is driven via the drive shaft, the differential gear, or the like. The lock is released and the parking release of the vehicle is achieved.
In this embodiment, the parking switching mechanism 3 drives the convex portion 2a of the lock lever 2 so as to approach and disengage in the radial direction of the parking gear 1, thereby switching between locking and unlocking. An example is shown.

  The parking switching mechanism 3 includes a biasing means 4 that biases the lock lever 2 toward the lock direction in which the convex portion 2a meshes with the parking gear 1, and a rotation that is driven to rotate in one direction and applies a displacement force to the lock lever 2. A cam 5 and a rotary actuator (an example of cam drive means, not shown) that rotationally drives the rotary cam 5 are provided.

  The urging means 4 is a spring that constantly urges the lock lever 2 toward the rotation center side of the parking gear 1 (the side where the convex portion 2 a meshes with the parking gear 1). Specifically, the spring is provided by a metal spring such as a torsion coil spring, a tension coil spring, or a compression coil spring. The urging means 4 shown in FIG. 1 uses a tension coil spring as an example. One end of the tension coil spring is locked to the lock lever 2, and the other end of the tension coil spring is connected to the parking gear 1 from the lock lever 2. The lock lever 2 is always urged toward the center side of the parking gear 1 by engaging with a fixing member (automatic transmission case or the like) on the side close to the rotation center.

On the outer periphery of the rotating cam 5, a cam surface that is slidably brought into direct contact with the lock lever 2 and applies a driving force to the lock lever 2 is provided over the entire periphery. That is, the outer peripheral surface of the rotating cam 5 is provided as a cam surface that gives a driving force to the lock lever 2.
Specifically, on the outer peripheral surface of the rotating cam 5, the distance between the rotation center X and the outer peripheral surface is gradually increased toward one rotation direction (right rotation direction in FIG. 1) starting from a predetermined rotation angle θ0. A spiral lift portion 5a is provided. The range of the spiral lift 5a is provided over 360 °. Further, on the outer peripheral surface of the rotating cam 5, between the maximum lift portion where the distance between the rotation center X and the outer peripheral surface is maximum and the minimum lift portion where the distance between the rotation center X and the outer peripheral surface is minimum, A release step portion 5b is provided in which the distance between the rotation center X and the outer peripheral surface is abruptly shortened.
In this embodiment, on the cam surface, the angle at which the distance between the rotation center X and the outer peripheral surface is maximum and the angle at which the distance is minimum are provided at the same angle.

  The lock lever 2 has a substantially rod shape or a substantially arc shape. On one end side of the lock lever 2, a rotation support portion 2b that is rotatably supported by a fixing member (such as an automatic transmission case) is provided. On the other end side of the lock lever 2, a displacement driving unit 2 c that is pressed against the outer peripheral surface of the rotating cam 5 by the urging force of the urging means 4 is provided. In addition, the convex part 2a in this Example is provided between the rotation support part 2b and the displacement drive part 2c.

  Here, when the rotating cam 5 is provided at the same axial position as the parking gear 1 and the parking gear 1 and the rotating cam 5 interfere with each other, the axial position of the rotating cam 5 becomes the axial position of the parking gear 1. It is provided at a position shifted from the position. In that case, the lock lever 2 is provided in a bent shape so that the convex portion 2 a can be engaged with and disengaged from the parking gear 1 and the displacement driving portion 2 c is always in contact with the outer peripheral surface of the rotating cam 5.

The rotary actuator that rotationally drives the rotary cam 5 is an actuator that uses an electric motor that generates rotational power when energized as a drive source.
Specifically, the rotary actuator of this embodiment includes an electric motor (for example, a well-known rotary motor such as a DC motor) that generates a unidirectional rotational force when energized from a battery, and the rotation generated by the electric motor. The urging force of the urging means 4 is a combination of a decelerator (eg, a decelerator that combines a plurality of gear trains, a known decelerator such as a cycloid decelerator) that decelerates the output and applies the rotation cam 5. Rotational torque that drives the lock lever 2 to the unlock side against the inclined load applied during parking is generated.

The energization state of the rotary actuator is controlled by an AT-ECU (electronic control unit for automatic transmission). That is, the electric motor in the rotary actuator is energized and controlled by the AT-ECU, and the parking switching device is switched between locking and unlocking.
The AT-ECU is a well-known configuration composed of a CPU that performs control processing and arithmetic processing, a storage device for storing various programs and data (memory such as ROM, SRAM or EEPROM, RAM), an input circuit, an output circuit, a power supply circuit, and the like. A microcomputer having a structure is mounted, and energization control of an electric actuator used for operation control of the automatic transmission is performed based on various sensor signals.

The AT-ECU is equipped with a parking switching program for performing energization control of the electric motor in the rotary actuator according to the setting state of the shift lever operated by the occupant.
This parking switching program changes the sliding contact position between the rotary cam 5 and the displacement drive unit 2c, that is, the rotation angle of the rotary cam 5, in accordance with the setting state of the shift lever. When the range is changed to another range (R range, N range, D range, etc .: hereinafter referred to as notP range), the sliding contact position between the rotary cam 5 and the displacement drive unit 2c becomes the maximum lift position. The rotating cam 5 is rotated in the direction of arrow A in FIG. When the shift lever is switched from the notP range to the P range, the rotary cam 5 is rotated in the direction of arrow A in FIG. 1 until the sliding contact position between the rotary cam 5 and the displacement driving unit 2c reaches the minimum lift position.
Note that the rotation angle control of the rotating cam 5 by the AT-ECU is performed by feedback control using a known angle sensor (for example, a potentiometer) or the like as an example.

(Operation of Example 1)
When the shift lever is set to the P range, the parking switching program sets the sliding contact position between the rotating cam 5 and the displacement driving unit 2c and the distance between the rotation center X and the outer peripheral surface on the outer peripheral surface of the rotating cam 5. Is set to the shortest side, that is, the minimum lift portion (see the solid line in FIG. 1).
Thereby, the convex part 2a of the lock lever 2 is engaged with the parking gear 1, and the vehicle is kept in the locked state (parking state).

When the shift lever is set from the P range to the notP range, the parking switching program energizes the electric motor to rotate the rotating cam 5 in one direction (direction of arrow A in the figure) slightly less than 360 °. And the sliding contact position between the rotary cam 5 and the displacement drive unit 2c is moved from the minimum lift part to the maximum lift part via the spiral lift part 5a (see the two-dot chain line in FIG. 1).
Due to the rotational displacement of the spiral lift portion 5a, the lock lever 2 is rotated away from the parking gear 1, the convex portion 2a of the lock lever 2 is detached from the parking gear 1, and the vehicle is unlocked ( Switch to parking released state.

When the shift lever is set from the notP range to the P range, the parking switching program energizes the electric motor to rotate the rotating cam 5 in one direction (arrow A direction in the figure) by a slight rotation angle, The sliding contact position between the rotary cam 5 and the displacement drive unit 2c is moved from the maximum lift part to the minimum lift part via the release step part 5b (see the solid line in FIG. 1).
As a result, by the action of the urging means 4, the lock lever 2 is rotated to the side closer to the parking gear 1, the convex portion 2a of the lock lever 2 is engaged with the parking gear 1, and the vehicle is locked from unlocking. Switch to (parking state).

(Effect of Example 1)
In the parking switching device of the first embodiment, as described above, when switching from unlocking to locking, the sliding contact position between the rotating cam 5 and the displacement driving unit 2c is changed from the maximum lift part of the spiral lift unit 5a. The rotary cam 5 is rotationally driven so as to shift to the minimum lift part of the spiral lift part 5a via the release step part 5b.
Thus, at the time of switching from unlocking to locking, by using the release step portion 5b, the rotation angle of the rotating cam 5 required for switching from unlocking to locking can be reduced (the unlocking → locking operation in FIG. 1). Switching time from unlock to lock can be shortened.
As a result, since the occupant sets the shift lever to the P range and immediately locks the drive wheels of the vehicle, safety and reliability at the time of setting the P range can be improved.

  In addition, since the rotary actuator that drives the rotary cam 5 is a drive source dedicated to the rotary cam using an electric motor, the restrictions on the mounting position of the rotary actuator can be reduced, and the mountability of the rotary actuator can be improved. it can. As a result, the rotary actuator can be mounted inside the automatic transmission case.

[Modification]
In the above embodiment, the parking switching mechanism 3 drives the convex portion 2a of the lock lever 2 so as to approach and separate in the radial direction of the parking gear 1, thereby switching between locking and unlocking. showed that. On the other hand, the parking switching mechanism 3 may be operated to drive the convex portion 2a of the lock lever 2 so as to approach and separate in the axial direction of the parking gear 1 to switch between locking and unlocking.
In the above-described embodiment, an example in which the release step portion 5b is provided along the diameter direction of the rotating cam 5 has been described. On the other hand, the release step 5b may have an inclination angle. Specifically, for example, a linear or arc-shaped inclined portion is provided on the entire release step portion 5b or on the inner diameter side of the release step portion 5b, and the displacement drive unit 2c is the minimum lift part when switching from unlock to lock. You may provide so that the force which collides with may be eased.

In the above embodiment, the cam surface is provided on the rotating cam 5, and the displacement driving portion 2c of the lock lever 2 is directly slidably contacted with the cam surface. On the other hand, a cam groove having a spiral lift portion 5a and a release step portion 5b may be provided in the rotating cam 5, and the displacement driving portion 2c of the lock lever 2 may be displaced along the cam groove. That is, the displacement driving portion 2 c of the lock lever 2 may be indirectly slidably contacted with the rotating cam 5.
In the above embodiment, an example of using a DC motor that rotates only in one direction when energized is shown as an example of the electric motor. However, other electric motors such as an electric motor that reverses the direction by switching the excitation direction, or a stepping motor may be used. It may be used.
In the above embodiment, the rotating cam 5 is driven only by a rotary actuator using an electric motor. However, the rotating cam 5 may be provided so as to be manually rotated, such as an emergency vehicle lock means. .

It is the schematic of a parking switching apparatus (Example 1). It is the schematic of SBW (conventional example).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Parking gear 2 Lock lever 2a Convex part 2b Rotation support part 2c Displacement drive part 3 Parking switching mechanism 4 Energizing means 5 Rotating cam 5a Spiral lift part 5b Release step part θ0 Predetermined rotation angle

Claims (3)

A parking gear provided on a drive shaft that always rotates in conjunction with a drive wheel of the vehicle;
A lock lever having a protrusion that can be engaged with and disengaged from the parking gear;
A parking switching mechanism for driving the lock lever to engage and disengage the protrusion from the parking gear;
In the parking switching device comprising:
The parking switching mechanism is
An urging means for urging the lock lever toward a lock direction in which the convex portion meshes with the parking gear;
A rotating cam that is rotationally driven in one direction and applies a displacement force to the lock lever;
Cam drive means for rotationally driving the rotary cam,
The rotating cam is rotationally driven in one direction by the cam driving means, so that a spiral lift portion that gradually separates the convex portion from the parking gear against the biasing force, and the convex portion is the parking portion. A release step portion that rapidly releases the gear from the gear, and when switching from unlock to lock, the sliding contact position between the lock lever and the rotating cam is from the maximum lift portion of the spiral lift portion. The parking switching device, wherein the rotary cam is rotationally driven by the cam driving means so as to shift to the minimum lift part of the spiral lift part via the release step part. The parking switching device according to claim 1, wherein
The parking switching device according to claim 1, wherein the cam driving means is a rotary actuator using an electric motor. In the parking switching device according to claim 1 or 2,
Wherein the outer peripheral surface of the rotating cam, the range of the spiral lifting unit distance is gradually increased between the rotation center and the outer peripheral surface toward the rotational direction of the one direction as a starting point a predetermined rotation angle over 3 60 ° Between the rotation center and the outer peripheral surface between the maximum lift portion where the distance between the rotation center and the outer peripheral surface is maximum and the minimum lift portion where the distance between the rotation center and the outer peripheral surface is minimum. The release step portion is provided, the distance of which decreases rapidly,
The lock lever is rotatably supported by a fixing member, and is provided at a portion away from the rotation support portion and pressed against the outer peripheral surface of the rotating cam by the urging force of the urging means. A displacement drive unit,
Parking switching characterized in that, as the rotary cam rotates, the displacement driving part of the lock lever is displaced along the outer peripheral surface of the rotary cam, whereby the convex part is displaced with respect to the parking gear. apparatus.

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