JP4395490B2 - Rod spring adhesion prevention structure in parking structure - Google Patents

Description

  The present invention relates to a parking structure for an automatic transmission, and more particularly to a structure for preventing sticking of a rod spring.

  The automatic transmission is provided with a parking structure that mechanically locks the output shaft of the transmission and prevents the vehicle from moving when the driver operates the select lever to the P range (stop position). .

  FIG. 7 shows a parking structure disclosed in Patent Document 1. When the driver operates the select lever to the P range, the lever 51 rotates to an angular position corresponding to the P range, and a base end portion 64 is rotatably connected to the parking lever 53 via the support hole 52. The joint portion 54 that is slidably supported moves in the right direction in the figure together with the parking rod 53 while being pressed against the joint receiving portion 65 by the rod spring 56.

  At this time, the cam portion 57 formed at the distal end portion of the parking rod 53 comes into contact with the inclined surface 59 formed inside the fixed shaft 58, and the enlarged diameter portion 60 sinks below the base end of the parking pole 61 and parks. Lift the proximal end of the pole 61. As a result, the parking pawl 61 rotates in the engaging direction (counterclockwise in the figure), and the engaging pawl 62 formed on the lower surface of the front end of the parking pawl 61 has the parking gear 63 fixed to the output shaft of the transmission. Engage with the tooth gap and lock the output shaft so that it cannot rotate (parking lock).

  When the engaging claw 62 collides with the tooth tip of the parking gear 63 and cannot be engaged, the parking pole 61 is returned in the releasing direction (clockwise in the figure) and the parking rod 53 is pushed back in the releasing direction (left in the figure). The rod spring 56 is compressed. The urging force of the rod spring 56 urges the parking pole 61 in the engaging direction via the parking rod 53, so that the parking pawl 61 presses the engaging claw 62 against the tooth tip surface of the parking gear 63. Wait (waiting operation).

After that, when the vehicle moves and the parking gear 63 rotates, the engaging claw 62 slides on the tooth tip surface of the parking gear 63 and the tooth groove of the parking gear 63 rotates to a position corresponding to the engaging claw 62. Then, the parking pole 61 rotates again in the engaging direction, the engaging claw 62 engages with the tooth groove, and parking locking is performed.
JP 2001-30883 A

  However, if the vehicle speed is not sufficiently reduced during the waiting operation, even if the tooth gap of the parking gear 63 rotates to the position corresponding to the engagement claw 62, the next tooth that the engagement claw 62 rotates is rotated. The parking pole 61 is flipped up in the release direction.

  When such jumping occurs, the parking rod 53 is returned to the releasing direction, and the rod spring 56 is compressed. At this time, the engagement claw 62 slides on the tooth tip surface of the parking gear 63. Therefore, the rod spring 56 may be in close contact (adjacent coils contact each other). When the rod spring 56 is in close contact, a large stress is generated inside the rod spring 56, which causes the durability of the rod spring 56 to be reduced.

  In order to avoid the close contact of the rod spring 56, the rod spring 56 may be extended in the axial direction. However, in this case, the parking rod 53 becomes long, and it becomes difficult to arrange in the transmission in terms of layout. Although it is conceivable to increase the spring constant of the rod spring 56, in this case, the rod spring 56 is less likely to contract during the waiting operation, and a smooth waiting operation becomes difficult.

  Further, the configuration described in Patent Document 1 is a configuration in which the rod spring 56 is centered by the parking rod 53, and thus there is a problem that the degree of freedom in design of the rod spring 56 is low. That is, even if it is attempted to change the spring constant by increasing the diameter of the rod spring 56, the gap between the rod spring 56 and the parking rod 53 is increased, and the amount of play and compression is increased. There was a limit to increasing the diameter.

  An object of the present invention is made in view of such a technical problem, and is to prevent the rod spring from contracting to the contact height without changing the axial length of the rod spring. Another object of the present invention is to improve the design flexibility of the rod spring.

In one aspect of the present invention, a spacer longer than the contact height of the rod spring is interposed between both seating surfaces of the rod spring , and this spacer has an outer diameter smaller than the inner diameter of the rod spring, and is attached to the parking rod. A cylindrical member to be externally fitted is formed, and a flange portion that forms one seating surface of the rod spring and has a recess formed on the back surface of the seating surface is formed on the base end side of the spacer, and the parking rod is radially formed. A pin that penetrates and regulates the axial displacement of the spacer and the flange portion is set in the recess.

  According to an aspect of the present invention, when the engaging pawl collides with the tooth tip of the parking gear and the parking pole is lifted up and the rod spring is greatly compressed, the spacer hits the seat surface and the maximum compression amount is reduced. Since the regulation is performed, the rod spring can be prevented from shrinking to the contact height.

Further, by changing the outer diameter of the spacer to fit the inner diameter of Rod spring, the rod spring backlash, it is possible to suppress the bending during compression, thereby improving the design freedom of the rod spring. In addition, the pin is housed in a counterbore formed on the back surface of the flange, and both end faces of the pin are opposed to the inner peripheral surface of the counterbore, so that the inner peripheral surface of the counterbore is the axis of the pin It functions as a stopper that regulates the directional displacement and reliably prevents the pin from falling off the parking rod.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 3 show a parking structure according to the present invention. FIG. 1 is a partial sectional view of a portion where the parking structure is provided, FIG. 2 is a sectional view taken along line XX of FIG. It is YY sectional drawing of FIG.

  The parking structure includes a parking gear 2 provided on the output shaft 1 of the transmission, a parking pole 4 having an engaging claw 3 that engages with the parking gear 2, a parking rod 5 that extends substantially perpendicular to the parking pole 4, A joint portion 6 fitted outside the rod 5 and a rod plate 7 that supports the joint portion 6 in a tiltable and rotatable manner are provided. In the figure, 8 is an input shaft of the transmission, and an output shaft of the engine is connected via a torque converter (not shown).

  The parking pole 4 is rotatably supported by a support shaft 9 extending parallel to the output shaft 1 at a position separated from the output shaft 1, and a torsion spring 10 is wound around the outer periphery of the support shaft 9. In a compressed state, the torsion spring 10 has one end locked to the inner wall of the recess 11 formed in the transmission case, and the other end locked to the upper edge of the parking pole 4. 4 is urged in the release direction (clockwise direction in FIG. 1).

  A substantially rectangular engagement claw 3 extending toward the parking gear 2 is formed on the lower surface of the front end of the parking pole 4. When the parking pole 4 rotates in the engagement direction (counterclockwise direction in FIG. 1) against the urging force of the torsion spring 10, and the engagement claw 3 engages with the tooth groove of the parking gear 2, the output shaft 1 is mechanically locked (parking lock).

  Further, a support member 12 having a support concave surface in the center facing the lower surface of the base end is fixed to the transmission case below the base end of the parking pole 4. A parking rod 5 is disposed between the bottom surface of the base end of the parking pole 4 and the concave support surface of the support member 12 with the tip portion inserted.

  As shown in FIGS. 2 and 3, a cam portion 13 having a diameter gradually increasing from a position adjacent to the support member 12 toward the rod distal end side is formed at the distal end portion of the parking rod 5. An enlarged-diameter portion 14 is formed. The cam portion 13 functions as a cam surface that lifts the base end of the parking pole 4 by contacting the bottom surface of the parking pole 4 and the support concave surface of the support member 12 when performing parking lock. It functions as a support member that supports the base end of the pole 4.

  On the other hand, the base end side of the parking rod 5 is a base end side shaft portion 15 having a diameter smaller than the diameter of the center of the rod, and the parking rod 5 has the base end side shaft portion 15 as a support hole of the joint portion 6. 16 is supported so as to be slidable in the axial direction.

  Further, the rod base end of the joint portion 6 is formed with the end surface on the rod base end side of the joint portion 6 as one seating surface and the flange portion 35 fixed to the base end portion of the parking rod 5 with the pin 20 as the other seating surface. The rod spring 21 is interposed between the end face on the side and the flange portion 35 in a compressed state, and the joint portion 6 is a joint receiver formed midway in the axial direction of the parking rod 5 by the urging force of the rod spring 21. It is pressed against the part 30. Here, the joint receiving portion 30 is formed by forming a step portion in the axial direction of the parking rod 5 by utilizing the difference between the diameter of the center of the rod and the diameter of the proximal end side shaft portion 15. You may form by fixing an annular receiving member to the outer periphery of the rod 5 with caulking etc.

  The base portion 23 extending downward from the joint portion 6 is supported so as to be tiltable and rotatable with respect to the rod plate 7. A projecting portion 24 extending laterally from the base end portion 23 is integrally formed at the lower end of the base portion 23 so that the joint portion 6 does not come out of the rod plate 7.

  As shown in FIG. 2, the rod plate 7 is fixed to a rotating shaft 25 that rotates in response to a driver's select lever operation. When the rotary shaft 25 rotates in response to the driver's operation of the select lever, the rod plate 7 rotates to an angular position corresponding to the position of the select lever (each range of L, D, N, R, and P). A plurality of valleys 26 are formed on the outer edge of the rod plate 7 corresponding to the position of the select lever, and when the holding pins 28 urged by the detent springs 27 are fitted into the valleys 26, the rod plate 7 is It is held at an angular position corresponding to the position of the select lever.

  FIG. 4 is a partial cross-sectional view showing the support structure of the rod spring 21.

  As shown in this figure, the proximal end side shaft portion 15 of the parking rod 5 has a cylindrical spacer 32 (tubular member) shown in FIG. 5 and a flange having a larger diameter than the spacer 32 provided on the proximal end side thereof. The portion 35 is externally fitted so as to be in close contact with the outer periphery of the proximal end side shaft portion 15. Further, on the base end side, the pin 20 passes through the parking rod 5 in the radial direction to restrict the displacement of the spacer 32 and the flange portion 35 toward the base end side.

  A tapered surface 33 is formed at the tip of the spacer 32, and the rod spring 21 is sheathed on the outer periphery of the spacer 32. The spacer 32 has an inner diameter that is approximately equal to the outer diameter of the proximal end side shaft portion 15 of the parking rod 5 and an outer diameter that is smaller than the inner diameter of the rod spring 21, preferably so that the rod spring 21 is in sliding contact with the outer peripheral surface of the spacer 32. The outer diameter of the rod spring 21 is substantially equal to the inner diameter of the rod spring 21, and the axial length is longer than the contact height of the rod spring 21. The contact height is the axial length of the rod spring 21 when the rod spring 21 is compressed and adjacent coils come into contact with each other.

  Further, on the back surface of the flange portion 35, that is, the back surface of the other seating surface of the rod spring 21, a seat having a depth substantially equal to the diameter of the pin 20 and an inner diameter substantially equal to the length of the pin 20. A counterbore (indentation) 37 is defined, and the counterbore 37 accommodates the pin 20. The flange portion 35 is pressed against the side surface of the pin 20 by the urging force of the rod spring 21, whereby the spacer 32 and the flange portion 35 are held at predetermined positions in the axial direction of the parking rod 5.

  Next, the operation of the parking structure will be described.

  When the driver operates the select lever from a range other than the P range to the P range (stop position), the rod plate 7 rotates clockwise in FIG. 2 about the rotation shaft 25 and corresponds to the P range by the detent spring 27. Held at the angular position. At this time, the joint portion 6 moves upward in FIG. 2 together with the parking rod 5 while being pressed against the joint receiving portion 30.

  As a result, the cam portion 13 provided at the distal end of the parking rod 5 enters between the lower surface on the proximal end side of the parking pole 4 and the support concave surface of the support member 12 and lifts the proximal end of the parking pole 4. The parking pole 4 rotates in the engaging direction (counterclockwise in FIG. 1) against the biasing force of the torsion spring 10, and engages the engaging claw 3 formed at the tip with the tooth groove of the parking gear 2. The output shaft 1 is locked so as not to rotate. When the engaging claw 3 hits the tip of the parking gear 2 and cannot be engaged, the parking pawl 4 is returned in the releasing direction (clockwise in FIG. 1) and waits until it can be engaged (waiting operation). ).

  In this waiting operation, in response to an input from the parking pole 4, the parking rod 5 is pushed back in the releasing direction (downward in the drawing in FIG. 2, leftward in the drawing in FIG. 3). The rod spring 21 is compressed away from. The biasing force of the rod spring 21 at this time biases the parking pole 4 in the engaging direction via the parking rod 5, and the parking pole 4 presses the engaging claw 3 against the tooth tip surface of the parking gear 2. Wait at.

  Thereafter, when the vehicle moves and the parking gear 2 rotates, the engaging claw 3 slides on the tooth tip surface of the parking gear 2, and the tooth gap of the parking gear 2 corresponds to the engaging claw 3 of the parking pole 4. When the parking rod 5 is rotated to the position, the parking rod 5 is moved in the engaging direction and the parking pawl 4 is rotated again in the engaging direction, and the engaging pawl 3 of the parking pawl 4 is engaged with the tooth gap of the parking gear 2. Lock is performed.

  When the vehicle speed is not sufficiently reduced, the engaging pawl 3 of the parking pole 4 collides with the tooth tip of the rotating tooth of the parking gear 2, and the parking pole 4 is flipped up in the releasing direction, so that the vehicle speed is sufficient. This operation (ratchet operation) is repeated until it drops to. At this time, the parking rod 5 is largely returned in the releasing direction, and the rod spring 21 is greatly compressed as compared with the case where the engaging claw 3 slides on the tooth tip surface of the parking gear 2.

  However, in the parking structure according to the present invention, even when the rod spring 21 is greatly compressed in this way, as shown in FIG. The end surface of the rod 6 comes into contact with the end surface of the joint portion 6 on the rod base end side, and the maximum compression amount of the rod spring 21 is restricted, so that the rod spring 21 is reliably prevented from coming into close contact.

  Further, in the above configuration, the pin 20 is housed in a spot facing portion 37 formed on the back surface of the flange portion 35, and both end faces of the pin 20 face the inner peripheral surface 37 s (inner wall) of the spot facing portion 37. Therefore, the inner peripheral surface of the spot facing portion 37 functions as a stopper that restricts the axial displacement of the pin 20, and reliably prevents the pin 20 from falling off the parking rod 5.

  Further, if the outer diameter (diameter thickness) of the spacer 32 is changed in accordance with the inner diameter of the rod spring 21, the play of the rod spring 21 and the bending at the time of compression can be suppressed. Can be improved. For example, when it is desired to increase the inner diameter of the rod spring 21, the outer diameter of the spacer 32 may be increased correspondingly.

  As mentioned above, although embodiment of this invention was described, the said embodiment only showed an example of the structure to which this invention was applied, and is not the meaning which limits the application range of this invention to the said structure. The above configuration can be modified without departing from the gist of the present invention, and these modified examples are of course included in the technical scope of the present invention.

  For example, the rod spring support structure can be widely applied to a parking structure having a waiting mechanism using a rod spring. The parking structure is a so-called “pull type” in which the cam portion is pulled from the opposite side to the parking pole side with the parking pole interposed therebetween, and is pulled up to the lower side of the base end of the parking pole to lift the parking pole. As disclosed in Japanese Patent Laid-Open No. 7-205773, a so-called “push type” in which the cam portion is pushed from the same side to the parking pole side with respect to the parking pole and is pushed to the lower side of the parking pole to lift the parking pole. It can also be applied to the rod spring support structure of the parking structure.

It is a fragmentary sectional view of an automatic transmission provided with the parking structure concerning the present invention. It is sectional drawing which shows the XX cross section of FIG. It is sectional drawing which shows the YY cross section of FIG. It is a fragmentary sectional view which shows the support structure of a rod spring. It is sectional drawing of a spacer and a flange part. It is a figure for demonstrating the effect of this invention. It is a schematic block diagram for demonstrating the conventional parking structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Output shaft 2 Parking gear 3 Engagement claw 4 Parking pole 5 Parking rod 6 Joint part 13 Cam part 21 Rod spring 32 Spacer (tubular member)
35 Flange part 37 Counterbore part (recessed part)

Claims (1)

A parking gear provided on the output shaft of the automatic transmission;
A parking pawl having an engaging claw that engages with a tooth groove of the parking gear and rotatably supported by a support shaft that is disposed apart from the output shaft;
A parking rod having a cam portion for rotating the parking pawl in a direction in contact with the parking pawl and engaging the engaging claw with a tooth groove of the parking gear;
A rod spring fitted around the parking rod;
A parking lock that engages the engaging claw with the tooth gap of the parking gear by operating the select lever to the stop position, and the engaging claw abuts against the tooth tip of the parking gear and engages with the tooth groove. In the parking structure for an automatic transmission configured to perform a waiting operation in a state in which the rod spring is compressed and the engaging claw is pressed against the tooth tip surface of the parking gear when it is not possible,
A spacer longer than the contact height of the rod spring is interposed between both seating surfaces of the rod spring ,
The spacer is a cylindrical member having an outer diameter smaller than an inner diameter of the rod spring, and is fitted on the parking rod.
On the base end side of the spacer, a flange portion is formed which constitutes one seating surface of the rod spring and a recess is formed on the back surface of the seating surface, and penetrates the parking rod in the radial direction. A parking structure for an automatic transmission, wherein a pin for restricting axial displacement of the spacer and the flange portion is accommodated in the recess .

Images