KR20120038908A - Parking mechnism for automatic transmission - Google Patents

Abstract

PURPOSE: A parking device of an auto transmission is provided to control elastic deformation by coupling or lifting a hooking part installed in a parking pole to a bearing of a parking gear and to improve strength reliability. CONSTITUTION: A hooking part(13) is coupled or lifted to a bearing of a parking gear. A parking pole(10) is contiguous to the hooking part. The parking pole establishes a projection part(14) which contacts to the bearing. The projection part is installed in both side of the hooking part. The distance of a gap between the projection part and the bearing is established based on elastic deformation amount of the parking pole. The gap between the projection part and the bearing is formed in the parking pole combination. The projection part executes high-frequency thermal treatment.

Description

Parking mechanism of automatic transmission {PARKING MECHNISM FOR AUTOMATIC TRANSMISSION}

The present invention relates to a parking mechanism of an automatic transmission for rotationally fixing a parking gear by engaging or releasing a hook portion provided on the parking pawl to a back portion of the parking gear.

Conventionally, the parking mechanism of the automatic transmission which engages and isolates the hook part of a parking pawl with respect to the parking gear provided in the output shaft of an automatic transmission, and performs rotation / stop of an output shaft is known (for example, refer patent document 1).

In this parking mechanism, the parking pawl is rotatably held by one of the rotating shafts provided on the transmission case, and the other end thereof is supported by the wedge for rotating the parking pawl so as to be detachably coupled.

Japanese Patent Application Publication No. 2009-236201

Usually, both the back portion and the hook portion in the parking mechanism are involute shapes. For this reason, when the force which tries to rotate a parking gear acts, the force (release force) which tries to cancel | park a perpendicular | vertical direction acts on the hook part of a parking pawl. As a result, when the driver selects and changes the parking range from the parking range to another range by the shift lever, the wedge moves in the direction of the parking pawl and the wedge axis, and the parking pawl must be released if the contact of the parking pawl is displaced. have.

However, in the parking mechanism of the conventional automatic transmission, the driver selects the parking range by the shift lever, and tries to rotate the parking gear by parking in the inclined state of the vehicle even if the output shaft of the automatic transmission cannot be rotated. Torque may act. At this time, since the vertical load acting on the hook portion acts as a bending load on the parking pole by the release force applied to the hook portion of the parking pawl vertically, the parking pole is elastically deformed with the wedge and the rotating shaft as the supporting points.

In addition, when the amount of elastic deformation increases due to the increase of the inclination angle of the vehicle or the like, there is a fear that the load of the parking pawl increases and the strength reliability decreases. In addition, in order to suppress the amount of elastic deformation, it is conceivable to increase the plate thickness of the parking pawl, but in this case, problems such as weight increase and cost increase will occur.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a parking mechanism of an automatic transmission that can suppress the elastic deformation of the parking pawl during the action of the releasing force and improve the strength reliability.

In order to achieve the above object, in the present invention, in the parking mechanism of the automatic transmission for rotationally fixing the parking gear by engaging or releasing the hook portion provided on the parking pawl to the back portion of the parking gear, the parking pawl is the hook portion. It is characterized by providing a protruding portion adjacent to and contacting the back part by elastic deformation of the parking pawl.

Therefore, in this invention, the protrusion which contacts the back part of a parking gear by the elastic deformation of this parking pawl is provided in the position adjacent to the hook part of a parking pawl. Therefore, the force acting in the vertical direction by the projections can be supported, and the elastic deformation of the hook portion can be suppressed.

In other words, the protruding portion provided adjacent to the hook portion contacts and supports the parking gear at a position closer to the inverted position of the force acting in the vertical direction than the position for supporting the parking pawl. Therefore, the distance from the release force input position to the release force support position can be shortened, and the bending moment and the warping amount of the parking pawl can be reduced.

As a result, the elastic deformation of the parking pawl at the time of the act of releasing force can be suppressed, and strength reliability can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the parking mechanism of the automatic transmission of 1st Example.
(A) is explanatory drawing which shows the parking gear and the parking pawl in the parking mechanism of the automatic transmission of 1st Example, (b) is the enlarged view of the A part in FIG.
3 is a perspective view illustrating a parking pawl;
4 is an explanatory diagram illustrating a waiting mechanism in the parking mechanism of the automatic transmission, in which (a) shows a locked state, and (b) shows a standby state.
5 is an explanatory diagram showing a parking gear and a parking pawl at the time of a climbing road parking lock;
Fig. 6 is an explanatory view illustrating the generation of the parking gear rotational force in the parking mechanism of the comparative example, (a) shows the parking lock state, (b) shows the release force generation, and (c) the parking pole deformation. (D) is a figure which shows the parking gear climb-out state.
The bending moment figure in the parking mechanism of a comparative example.
FIG. 8 is an explanatory view for explaining a parking gear rotational force generation time in the parking mechanism of the automatic transmission of the first embodiment, (a) shows a parking lock state, (b) shows a release force generation time, and (c ) Shows when the parking pole deformation occurs, and (d) shows the projection contact state.
9 is a bending moment diagram in a parking mechanism of the automatic transmission of the first embodiment.
10 is an enlarged view of an essential part showing a protrusion contact state in the parking mechanism of the automatic transmission of the first embodiment in the case of steel sheet.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the parking mechanism of the automatic transmission of this invention is demonstrated based on the 1st Example shown in drawing.

[First Embodiment]

First, the configuration will be described.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the parking mechanism of the automatic transmission of 1st Example. FIG. 2A is an explanatory diagram showing a parking gear and a parking pawl in the parking mechanism of the automatic transmission of the first embodiment, and FIG. 2B is an enlarged view of portion A in FIG. 2A. 3 is a perspective view illustrating a parking pawl.

The parking mechanism 1 of the automatic transmission shown in FIG. 1 is disposed in the transmission case 1a, and has a manual lever 2, a manual plate 3, a parking rod 4, a parking pawl 10, And a parking gear 20.

The manual lever 2 is pivotally mounted to the transmission case 1a and is connected to the shift lever 6 via the select rod 5. And it oscillates in conjunction with the operation of the shift lever 6 by a driver.

The manual plate 3 is connected to the manual lever 2 and moves integrally with the manual lever 2 to move the parking rod 4 in the axial direction.

One end of the parking rod 4 is connected to the manual plate 3, and the other end of the parking rod 4 is inserted into the wedge 7 so as to be slidable. This wedge 7 is urged to the parking rod tip 4a side by the spring 7a provided in the parking rod 4, and is prevented from falling out at the parking rod tip.

The parking pawl 10 is disposed at the outer circumferential position of the parking gear 20 as shown in FIG. 2 and extends in the circumferential direction along the outer circumferential surface of the parking gear 20. This parking pawl 10 is rotatably held at one end by a rotating shaft 11 fixed to the transmission case 1a. Moreover, the wedge accommodating part 12 which contacts the wedge 7 is formed in the other end part of the parking pawl 10, and is supported by the wedge 7. As shown in FIG. In addition, as shown in FIG. 3, a middle portion of the parking pawl 10 includes a hook portion 13 that engages and detachably engages with the back portion 21 of the parking gear 20, and the hook portion 13. A pair of projections 14 and 14 located on both sides are provided. The hook portion 13 and the pair of protrusions 14 and 14 protrude toward the parking gear 20. In addition, the hook portion 13 and the pair of protrusions 14 and 14 are subjected to high frequency heat treatment to increase the surface hardness.

The pair of protrusions 14 and 14 are formed adjacent to the hook portion 13. Each of the protrusions 14 is in contact with the teeth 21 of the parking gear 20 by the elastic deformation of the parking pawl 10 that occurs when a vertical load is applied to the hook 13. At this time, the protrusion 14 is in contact with the outer diameter of the tooth portion 21 engaged with the hook portion 13, that is, the tooth end surface 21a of the tooth portion 21 engaged with the hook portion 13. Here, the projection part 14 on the rotating shaft 11 side contacts the back part 21 when the parking pole is released from the climbing path, and the projection part 14 on the wedge receiving part 12 side is the parking pole in the steel plate furnace. It contacts the back part 21 at the time of release.

And the height of the projection part 14 is the height which the clearance gap S generate | occur | produces with the distal end surface 21a of the tooth part 21 at the time of parking pawl engagement (parking lock) ((b) of FIG. ) Reference]. The distance W1 between the gap S between the protrusions 14 and the teeth 21 generated during the parking pawl engagement is set based on the amount of elastic deformation of the parking pawl 20. In addition, the pressure angle θ2 of the protrusion 14 can be changed in accordance with the number of teeth of the parking gear 20.

The parking gear 20 is a gear fixed on the transmission output shaft 1b, and the hook portion 13 provided on the parking pawl 10 is fixed to rotation by being coupled to or released from the teeth 21.

Next, the operation will be described.

First, the "basic operation of the parking mechanism of the automatic transmission" and "technical problem of the parking mechanism of the comparative example" will be described, and then the "strain prevention action" in the parking mechanism of the automatic transmission of the first embodiment will be described. .

[Basic operation of the parking mechanism of the automatic transmission]

4 is an explanatory diagram illustrating a waiting mechanism in the parking mechanism of the automatic transmission, in which (a) shows a locked state and (b) shows a standby state. It is explanatory drawing which shows the parking gear and the parking pawl at the time of the climbing road parking lock.

In general, in the parking mechanism, when the shift lever selects the parking position (P range), the manual lever rotates to move the parking rod 30. As a result, as shown in FIG. 4A, the wedge 31 supports the support 38 provided at a position facing the wedge receiving portion 33 of the parking pawl 32 by the pressing force of the spring 39. Riding over, push up the wedge receiving portion (33). Thereby, the parking pawl 32 rotates about the rotation shaft 34, and the hook part 35 meshes with the back part 37 of the parking gear 36. As a result, the transmission output shaft is locked.

On the other hand, when the outer circumference of the hook portion 35 of the parking pawl 32 collides with the outer circumference of the back portion 37 of the parking gear 36, the parking pawl 32 cannot be rotated. As shown in the figure, the wedge 31 is fitted to the support 38 and the wedge receiving portion 33 and cannot move. Therefore, the spring 39 is pressed and compressed to be in a standby state. At this time, the wedge 31 is pressurized by the spring 39 to the rod tip 30a side, and the force which tries to park-lock always acts. And when the hook part 35 of the parking pawl 32 overlaps with the teeth of the parking gear 36, the wedge 31 pressed by the spring 39 passes over the support 38, and the parking pawl 32 Rotate the) to lock it. This is what is called a waiting mechanism.

In addition, as shown in FIG. 5, when the force F (alpha) which tries to rotate the parking gear 36 acts in the state which parks and locks a car in a climbing path, this force (F (alpha)) is a two-part ( 37 is delivered to the hook portion 35. At this time, since both the teeth portion 37 and the hook portion 35 are involute shapes having a pressure angle, the force Fα is a force F1 (hereinafter referred to as "release force") F1 and the parking which is intended to release the parking, It is divided by the force (F2) for inserting the pole (32).

Here, the release force F1 is a force acting in the vertical direction with respect to the hook portion 35 of the parking pawl 32, but the wedge 31 supports this release force F1. And when the wedge 31 shifts, the parking pawl 31 rotates around the rotating shaft 34 by the releasing force F1, and is shifted | deviated from the parking gear 36. As shown in FIG.

[Technical problem of parking mechanism of comparative example]

Fig. 6 is an explanatory view illustrating the generation of the parking gear rotational force in the parking mechanism of the comparative example, (a) shows the parking lock state, (b) shows the release force generation, and (c) the parking pole deformation. The occurrence time is shown, and (d) shows the parking gear up state. 7 is a bending moment diagram in the parking mechanism of the comparative example.

As shown in FIG. 6A, in the parking lock state, the hook portion 41 of the parking pawl 40 meshes with the back portion 43 of the parking gear 42, and the side surface of the hook portion 41. The side surface of the back part 43 is in contact.

On the other hand, when the force Fα for rotating the parking gear 42 acts, as shown in Fig. 6B, the release force F1 in the vertical direction from the tooth portion 43 to the hook portion 41 is shown. Works.

As a result, as shown in FIG. 6C, the parking pawl 40 is elastically deformed into a bow-shaped shape gradually with the wedge 44 and the rotation shaft 45 as the supporting points. The bending moment diagram when the releasing force F1 is acting on the parking pawl 40 is as shown in FIG.

In FIG. 7, the input position of the release force F1 is the contact position of the hook part 41 and the tooth part 43, and L is the support position by the rotating shaft 45 from the support position by the wedge accommodating part 44. In FIG. Distance. And L1 is the distance from the wedge receiving portion supporting position to the release force input position, L2 is the distance from the rotation shaft supporting position to the release force input position, Ra is the supporting force in the wedge receiving portion 44, and Rb is It is a bearing force in the rotating shaft 45. Thereby, the following formulas (1) to (4) are established.

Therefore, according to the equations (1) to (4), the bearing force Ra in the wedge accommodating portion 44 and the bearing force Rb in the rotation shaft 45 are expressed by the following equations (5) and (6). You can get it.

By the following equations (5) and (6), the bending moment M1 _max and the warpage amount δ1 acting on the parking pawl 40 are obtained by the following expressions (7) and (8), respectively.

Where E is the Young's modulus and I is the cross-sectional secondary moment.

When the elastic deformation amount, that is, the warp amount δ1 increases, the hook portion 41 of the parking pawl 40 shifts from the tooth portion 43 as shown in FIG. 6 (d). The back part 43 rides on the hook part 41. In this state, the load of the parking pawl 40 becomes large, the strength reliability falls, and stress concentration may generate | occur | produce in the vicinity of the base part of the hook part 41, and the parking pawl 40 may be damaged.

In addition, in order to suppress the elastic deformation amount of the parking pawl 40, it is thought that the plate | board thickness of the parking pawl 40 is increased, but in that case, since problems, such as weight increase and cost increase, arise, it is unpreferable.

[Anti-deformation action]

FIG. 8 is an explanatory view for explaining a parking gear rotational force generation time in the parking mechanism of the automatic transmission of the first embodiment, (a) shows a parking lock state, (b) shows a release force generation time, and (c ) Shows when the parking pole deformation occurs, and (d) shows the protrusion contact state. 9 is a bending moment diagram in the parking mechanism of the automatic transmission of the first embodiment.

When the parking lock is performed in the parking mechanism of the automatic transmission of the first embodiment, as shown in Fig. 8A, the hook portion 13 of the parking pawl 10 is coupled with the teeth 21 of the parking gear 20. The side surface of the hook part 13 and the side surface of the tooth part 21 contact | engage. At this time, the protrusion part 14 provided adjacent to the hook part 13 opposes with the clearance S in the state which provided the clearance S between the end surface 21a of the tooth part 21 which meshed with the hook part 13.

When the force Fα for rotating the parking gear 20 in the clockwise direction acts here, as shown in FIG. 8B, the release force F1 acts in a direction perpendicular to the hook portion 13. do. That is, a vertical load is applied to the hook portion 13 of the parking pawl 10 with the wedge 7 and the rotating shaft 11 as supporting points, and act as a bending load on the parking pawl 10.

As a result, as shown in FIG. 8C, the parking pawl 10 is elastically deformed into a bow-shaped shape gradually with the wedge 7 and the rotating shaft 11 as the supporting point. And when the elastic deformation amount of this parking pawl 10 becomes more than fixed, as shown in FIG.8 (d), the projection part 14 of the rotating shaft 11 side of the parking pawl 10 is a parking gear ( It contacts the tooth part 21 of 20. Here, although the protrusion part 14 contacts the tooth | tip end surface 12a of the tooth part 21 which meshed with the claw part 13, it contacts the outer part spaced apart from the claw part 13 of this tooth | tip end surface 21a. The bending moment diagram at this time is as shown in FIG.

In FIG. 9, the input position of the release force F1 is the contact position of the hook portion 13 and the tooth portion 21, and L ′ is supported by the protrusion 14 from the support position by the wedge receiving portion 7. The distance to the location. And L1 is the distance from the wedge receiving portion supporting position to the release force input position, L4 is the distance from the protrusion supporting position to the release force input position, Rc is the supporting force in the wedge receiving portion 7, and Rd is It is the bearing force in the projection part 14. Thereby, the following formulas (9) to (12) are established.

Therefore, according to the equations (9) to (12), the bearing force Rc in the wedge accommodating portion 7 and the bearing force Rd in the protrusion 14 are expressed by the following equations (13) and (14). You can get it.

By the following equations (13) and (14), the bending moment M2 _max and the amount of deflection δ2 acting on the parking pawl 10 are determined by the following equations (15) and (16), respectively.

Where E is the Young's modulus and I is the cross-sectional secondary moment.

In the parking mechanism 1 of the automatic transmission of the first embodiment, L2 > L4 compared with the parking mechanism of the comparative example, and the support point for supporting the release force F1 is more released than the case where the rotation point supports the rotation shaft. It is moving to a position close to the input position. Therefore, the release force support interval can be shortened than when the wedge and the rotating shaft are supported, and the following expressions (17) and (18) are established.

Thus, the projecting portion 14 is by contacting the chin 21, the bending moment (M2 _max) and a bending amount (δ2) acting on parking pawl 10 can be suppressed more than the case of the comparative example for supporting the wedge and the rotary shaft.

As a result, the elastic deformation of the parking pawl 10 when the release force F1 acts on the hook portion 13 can be suppressed, and the strength reliability of the parking pawl 10 can be improved.

Particularly, in the parking mechanism of the automatic transmission of the first embodiment, the protruding portion 14 is an outer portion spaced apart from the hooking portion 13 of the tip surface 21a which is the outer diameter of the toothing portion 21 engaged with the hooking portion 13. To contact. Therefore, the projection part 14 can contact the position closest to a release force input position. Thereby, the support interval can be made into the shortest part, and the elastic deformation of the parking pawl 10 can be suppressed more effectively.

Moreover, since the projection part 14 is provided in the both sides of the hook part 13, when parking-locking in the steel plate furnace, as shown in FIG. 10, the projection part 14 provided in the wedge accommodating part 12 side is shown. Can be in contact with the teeth 21 of the parking gear 20 to support the release force. Thereby, the elastic deformation of the parking pawl 10 can be suppressed in any of a climbing path and a steel plate.

And the space | interval W1 of the clearance gap S between the protrusion part 14 and the tooth part 21 which generate | occur | produces at the time of parking pawl engagement is set based on the elastic deformation amount of the parking pawl 10. For this reason, when the elastic deformation of a predetermined magnitude | size arises, the protrusion part 14 and the tooth part 21 can contact reliably, and the release force F1 can be supported by the protrusion part 14. That is, by adjusting the space | interval W1 of this clearance gap S, it becomes possible to adjust the elastic deformation amount of the parking pawl 10.

In addition, in the parking mechanism of the automatic transmission of the first embodiment, since the high frequency heat treatment is performed on the protruding portion 14, the surface hardness of the protruding portion 14 is improved, and wear due to contact with the tooth portion 21 can be prevented.

Next, the effect will be described.

In the parking mechanism of the automatic transmission of the first embodiment, the following effects can be obtained.

(1) The parking mechanism 1 of the automatic transmission for rotating and fixing the parking gear 20 by engaging or releasing the hook portion 13 provided on the parking pawl 10 to the back portion 21 of the parking gear 20. ), The parking pawl 10 is adjacent to the hook portion 13 and has a configuration in which a protrusion 14 is provided in contact with the back portion 21 by elastic deformation of the parking pawl 10. .

For this reason, elastic deformation of the parking pawl 10 at the time of the act of releasing force can be suppressed, and strength reliability can be improved.

(2) The protruding portion 14 was configured to be provided on both sides of the hook portion 13.

For this reason, any of the climbing paths can contact with a shortest part at the time of elastic deformation of the hook part 13 with a steel plate, and can make the support spacing of the parking pawl 10 the shortest part, and a parking pawl more effectively. The elastic deformation of (10) can be suppressed.

(3) The interval W1 between the protrusion S 14 and the gap S between the teeth 21 generated during parking pawl engagement is set based on the amount of elastic deformation of the parking pawl 10.

For this reason, the protrusion part 14 can be reliably contacted by the elastic deformation of a predetermined magnitude | size, and the amount of elastic deformation of the parking pawl 10 can be adjusted.

(4) The protrusions 14 were configured to perform high frequency heat treatment.

For this reason, the surface hardness of the protrusion part 14 improves, and the abrasion by contact with the tooth part 21 can be prevented.

As mentioned above, although the parking mechanism of the automatic transmission of this invention was demonstrated based on 1st Example, the specific structure is not limited to this 1st Example, The summary of invention regarding each claim of a claim is described. Changes or additions to the design are permitted unless otherwise deviated.

In the parking mechanism of the first embodiment, the hook portion 13 is provided in the middle portion of the parking pawl 10. For example, the hook portion 13 is rotatably held in the middle portion of the parking pole, and the hook portion is provided at the end. It may be. Even in this case, the elastic deformation of the parking pawl can be suppressed by providing projections contacting the back portions of the parking gear by elastic deformation of the parking pawls on both sides of the hook portion.

1: parking mechanism
2: manual lever
3: manual plate
4: parking rod
7: wedge
10: parking pole
11: axis of rotation
12: wedge receptacle
13: hook part
14: protrusion
20: parking gear
21: This part
21a: this end
Fα: force to rotate the parking gear
F1: Release Force

Claims (4)

In the parking mechanism of the automatic transmission for rotating and fixing the parking gear by engaging or releasing the hook portion provided on the parking pawl to the back of the parking gear,
The parking pawl is adjacent to the hook portion, and the parking mechanism of the automatic transmission, characterized in that a projection is provided in contact with the back part by elastic deformation of the parking pawl. The parking mechanism of the automatic transmission according to claim 1, wherein the projection is provided on both sides of the hook portion. The parking mechanism of the automatic transmission according to claim 1 or 2, wherein an interval between the protrusions and the gaps generated during the parking pawl engagement is set based on the amount of elastic deformation of the parking pawl. The parking mechanism of the automatic transmission according to claim 1 or 2, wherein the protrusion is subjected to a high frequency heat treatment.

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