Mounting structure of return spring

Abstract

To provide a mounting structure of a return spring capable of improving workability of assembly work of the return spring.SOLUTION: A mounting structure of a return spring 5 has the return spring 5 which is provided in a transmission case 2 and energizes a parking pole 4 in a direction of disengagement from a parking gear 3. The return spring 5 has: a winding part 5A into which a support shaft 7 is inserted; a first arm part 5B which extends outward from a winding starting terminal of the winding part 5A and of which a distal end portion is engaged with the parking pole 4; and a second arm part 5C which extends outward from a winding ending terminal of the winding part 5A and of which a distal end portion is engaged with a stopper part 7A. The support shaft 7 has a shaft part 7B which is inserted into the winding part 5A of the return spring 5 and the stopper part 7A which protrudes from the shaft part 7B in a radial direction and to which the distal end portion of the second arm part 5C is engaged, and the support shaft 7 is inserted into a hole part 2a, which is formed in the transmission case 2, in a freely rotatable manner.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a mounting structure for a return spring. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a parking mechanism for an automatic transmission described in Patent Document 1 is known as a parking mechanism having a spring for disengaging a parking pole from a parking gear.

[0003] The parking mechanism of this automatic transmission has a claw pole having a claw that engages with the parking gear, which is rotatably connected to a pole shaft, and a support plate fixed to the case by a bolt is provided near the tip of the claw pole.

[0004] The torsion spring, which generates a biasing force to separate the pawl from the parking gear, has a wound portion (the center portion of the torsion spring) into which a bolt and a spacer are inserted, and the bolt is inserted into the wound portion.

[0005] One end of the torsion spring is fixed to the support plate, and the other end of the torsion spring engages with the engagement surface of the claw pole, so that the torsion spring biases the claw of the claw pole in a direction to disengage from the parking lock. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 1-41534 Summary of the Invention [Problem to be solved by the invention]

[0007] In conventional automatic transmission parking mechanisms, when assembling a torsion spring to a case, it is necessary to elastically deform the torsion spring while screwing a bolt into the winding portion so that one end and the other end of the torsion spring engage with the engagement surfaces of a support plate and a claw pole, respectively.

[0008] This means that the work of assembling the torsion spring is delicate work that requires careful attention, and force is also required to elastically deform the torsion spring, which causes a problem that the workability of the work of assembling the torsion spring is deteriorated.

[0009] The present invention has been made in view of the above-mentioned circumstances, and has an object to provide a mounting structure for a return spring that can improve the workability of assembling the return spring. [Means for solving the problem]

[0010] The present invention provides an attachment structure for a return spring that is provided in a transmission case and biases the parking pole in a direction away from the parking gear, the return spring having a spirally wound winding portion into which a support shaft is inserted, a first arm portion that extends outward from the winding start end of the winding portion and has a tip portion that engages with the parking pole, and a second arm portion that extends outward from the winding end end of the winding portion and has a tip portion that engages with a stopper portion of the support shaft, the support shaft having a shaft portion that is inserted into the winding portion of the return spring and the stopper portion that protrudes radially from the shaft portion and engages with the tip portion of the second arm portion, and the support shaft is rotatably inserted into a hole formed in the transmission case. Effect of the Invention

[0011] As described above, according to the present invention, the workability of assembling the return spring can be improved. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a view of a portion of a transmission equipped with a mounting structure for a return spring according to one embodiment of the present invention, as viewed from the axial direction of a support shaft. [Diagram 2] FIG. 2 is a perspective view of a portion of a transmission equipped with a return spring mounting structure according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a perspective view of a support shaft and a return spring of a mounting structure for a return spring according to one embodiment of the present invention. [Figure 4] FIG. 4 is a view of a part of a transmission equipped with a mounting structure for a return spring of another shape according to one embodiment of the present invention, viewed from the axial direction of the support shaft, showing a protrusion that restricts the rotation of the stopper portion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A mounting structure for a return spring according to one embodiment of the present invention is a mounting structure for a return spring that is provided on a transmission case and urges a parking pole in a direction to disengage from the parking gear, the return spring being wound spirally and having a winding portion into which a support shaft is inserted, a first arm portion extending outward from the winding start end of the winding portion and having a tip portion which engages with the parking pole, and a second arm portion extending outward from the winding end end of the winding portion and having a tip portion which engages with a stopper portion of the support shaft, the support shaft having a shaft portion inserted into the winding portion of the return spring and a stopper portion protruding radially from the shaft portion and with which the tip portion of the second arm portion engages, and the support shaft is rotatably inserted into a hole formed in the transmission case.

[0014] As a result, the return spring mounting structure according to the embodiment of the present invention can improve the workability of the return spring assembly work. EXAMPLES

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mounting structure for a return spring according to an embodiment of the present invention will now be described with reference to the drawings.

[0016] 1 to 4 are diagrams showing a mounting structure for a return spring according to one embodiment of the present invention. 1 to 4, for convenience of explanation, the up-down, front-rear, left-right directions are based on the case where the axial direction of the support shaft of the return spring is set vertically, the vertical direction is the up-down direction, and the direction in which the stopper part of the support shaft is arranged is the up direction. The direction of an imaginary line that is perpendicular to the up-down direction and connects the support shaft and the parking pole shaft when viewed from the axial direction is the front-rear direction, and the direction perpendicular to the front-rear direction in the horizontal plane is the left-right direction.

[0017] First, the configuration will be described. In FIG. 1, a transmission 1 changes the power (rotation speed) of an internal combustion engine (not shown), and transmits the changed power from a differential device (not shown) to left and right drive wheels via left and right drive shafts.

[0018] The transmission 1 includes a transmission case 2, and a parking gear 3, a parking pole 4, and a return spring 5 that constitute a parking lock mechanism are provided in the transmission case 2. The transmission 1 of this embodiment constitutes a transmission for a vehicle.

[0019] The parking gear 3 is provided on a rotating shaft 11. The rotating shaft 11 is a shaft located on a power transmission path that transmits the power input from the engine to the differential device, and the parking gear 3 rotates integrally with the rotating shaft 11.

[0020] The parking pole 4 is rotatably supported on the partition wall 2A of the transmission case 2 via a parking pole shaft 6. The parking pole 4 is formed with a claw portion 4a.

[0021] When the parking pole 4 rotates right (clockwise) in FIG. 1 around the parking pole shaft 6 as the rotation center, the claw portion 4 a formed on the parking pole 4 meshes with the teeth portion 3 a of the parking gear 3 .

[0022] When the parking pole 4 rotates left (counterclockwise) in FIG. 1 around the parking pole shaft 6, the engagement between the claw portion 4a and the teeth portion 3a is released.

[0023] In this manner, the parking pole 4 rotates (swings about the parking pole shaft 6) between an engagement position where the claw portion 4a engages with the teeth portion 3a and a disengagement position where the claw portion 4a disengages from the teeth portion 3a.

[0024] When the claw portion 4a meshes with the tooth portion 3a, the rotation of the parking gear 3 is restricted, and the rotation of the rotary shaft 11 is restricted.

[0025] Since the rotating shaft 11 is linked to the drive wheels in the power transmission path, restricting the rotation of the parking gear 3 restricts the rotation of a final driven gear (not shown) of the differential device to which power is transmitted from the rotating shaft 11. As a result, the rotation of the drive wheels via the drive shaft is restricted, and the vehicle is maintained in a stopped state.

[0026] The return spring 5 biases the parking pole 4 counterclockwise in FIG. 1 so that the claw portion 4a of the parking pole 4 disengages from the teeth portion 3a of the parking gear 3.

[0027] The parking pole 4 has a pole body 4A extending linearly from the support position of the parking pole shaft 6, and the claw portion 4a protrudes in a direction approximately perpendicular to the extension direction of the pole body 4A toward the side where the parking gear 3 is positioned.

[0028] The parking pole 4 has an engagement portion 4B for engaging with the return spring 5. The engagement portion 4B extends in a direction substantially perpendicular to the extension direction of the pole body 4A and in the opposite direction to the claw portion 4a. The engagement portion 4B has an engagement surface 4b that a first bent portion 5b of the return spring 5, which will be described later, abuts against and engages with. The engagement surface 4b is formed on a surface in the left-right direction.

[0029] As shown in FIGS. 1 and 2, the return spring 5 has a wound portion 5A, a first arm portion 5B, and a second arm portion 5C.

[0030] The winding portion 5A is wound in a right-handed spiral shape, and a space is formed inside the winding portion 5A. The first arm portion 5B extends in a tangential direction continuing from the winding start end of the winding portion 5A (the upper end of the winding portion 5A) to the winding portion 5A, and the second arm portion 5C extends in a tangential direction continuing from the winding end of the winding portion 5A (the lower end of the winding portion 5A) to the winding portion 5A.

[0031] The second arm portion 5C may extend outward from the winding start end of the wound portion 5A, and the first arm portion 5B may extend outward from the winding end end of the wound portion 5A.

[0032] A first bent portion 5b is formed at the tip of the first arm portion 5B, and the first bent portion 5b is bent downward from the tip of the first arm portion 5B.

[0033] In other words, the first bent portion 5b has its end extending downward from top to bottom along the axial direction of the winding portion 5A (the axial direction of the parking pole shaft 6), and is positioned at the same axial position as the winding portion 5A.

[0034] A second bent portion 5c is formed at the tip of the second arm portion 5C, and the second bent portion 5c is bent upward from the tip of the second arm portion 5C.

[0035] In other words, the second folded portion 5c has its end extending upward from bottom to top along the axial direction of the winding portion 5A (the axial direction of the parking pole shaft 6), and is positioned at the same axial position as the winding portion 5A.

[0036] For this reason, the first bent portion 5b and the second bent portion 5c are positioned in the same axial position as the winding portion 5A, but the connection positions with the first arm portion 5B and the second arm portion 5C are different above and below, and the first bent portion 5b and the second arm portion 5C are bent in opposite directions from the first arm portion 5B and the second arm portion 5C.

[0037] Furthermore, the first arm portion 5B is longer than the second arm portion 5C, and the return spring 5 can be compressed with a relatively small force by applying a force to the first bent portion 5b.

[0038] A shaft portion 7B of a support shaft 7 is inserted into the wound portion 5A of the return spring 5. One end of the shaft portion 7B of the support shaft 7 is inserted into a cylindrical hole portion 2a formed in the partition wall 2A. The support shaft 7 is rotatably supported in the hole portion 2a of the partition wall 2A.

[0039] A stopper portion 7A is provided at the other end (upper end) of the support shaft 7. The stopper portion 7A extends in a direction (horizontal direction) perpendicular to the axial direction (vertical direction) of the support shaft 7 and is formed in a plate shape that is wide in the vertical direction. This wide surface is the surface with which the second bent portion 5c of the return spring 5 abuts and engages.

[0040] The first bent portion 5b engages with the engagement surface 4b of the parking pole 4, and the second bent portion 5c engages with the stopper portion 7A.

[0041] When first arm portion 5B and second arm portion 5C are pressed in a direction decreasing the included angle, winding portion 5A elastically deforms, and the spring force of winding portion 5A generates a spring force (repulsive force) in a direction moving them away from each other.

[0042] When the return spring 5 is attached to the transmission 1, the wound portion 5A is elastically deformed, and the spring force of the wound portion 5A generates a spring force in the directions in which the wound portions move away from each other.

[0043] The parking lock mechanism is provided with a parking rod 8 and a parking cam 9. The parking rod 8 is provided so as to be movable in the axial direction in response to the operation of an operating lever (not shown), and the parking cam 9 is provided at the tip of the parking rod 8.

[0044] The parking pole 4 is pushed by the parking cam 9, so that the claw portion 4a rotates from the disengaged position to the engaged position. At this time, the first arm portion 5B moves in a direction approaching the second arm portion 5C (moves so as to reduce the included angle).

[0045] In this state, the spring force of the winding portion 5A biases the first arm portion 5B in a direction away from the second arm portion 5C.

[0046] Since the first arm portion 5B is biased away from the second arm portion 5C in this manner, when the pressure applied by the parking cam 9 to the parking pole 4 is released, the force of the first bent portion 5b pressing against the engagement surface 4b causes the parking pole 4 to rotate so that the claw portion 4a disengages from the tooth portion 3a.

[0047] A stopper member 10 is provided on the partition wall 2A, and when the parking pole 4 is rotated to the release position, the parking pole 4 comes into contact with the stopper member 10 to restrict the rotation. In other words, the spring force of the winding portion 5A acts on the parking pole 4 via the first arm portion 5B, and presses the pole body 4A of the parking pole 4 against the stopper member 10.

[0048] An inclined surface 2b is formed on the side wall 2B of the transmission case 2, and the inclined surface 2b inclines rearward as it goes from right to left. The tip 7a of the stopper portion 7A abuts against the inclined surface 2b. In other words, in the state shown in FIG. 1, the counterclockwise rotation of the support shaft 7 is restricted by the stopper portion 7A abutting against the inclined surface 2b.

[0049] Since the first arm portion 5B and the second arm portion 5C are biased in directions away from each other, the tip 7a of the stopper portion 7A is pressed against the inclined surface 2b by the force from the second arm portion 5C, which is a reaction force of the spring force of the winding portion 5A pressing the stopper portion 7A against the inclined surface 2b. This restricts the support shaft 7 from rotating counterclockwise. In this embodiment, the side wall 2B constitutes a wall portion, and the inclined surface 2b constitutes a rotation restricting portion.

[0050] Next, a procedure for attaching the return spring 5 of this embodiment will be described. The support shaft 7 is inserted into the wound portion 5A of the return spring 5, and the second bent portion 5c of the return spring 5 is brought into contact with the stopper portion 7A. Then, a force is applied to the first bent portion 5b to compress the return spring 5.

[0051] The reaction force at this time can be received by the stopper portion 7A extending toward the outer diameter side of the support shaft 7 beyond the second bent portion 5c, and the return spring 5 can be easily compressed and deformed (elastically deformed) without hurting the operator's fingers.

[0052] With the return spring 5 in a compressed (elastically deformed) state, one end of the support shaft 7 is inserted into the hole 2a of the partition wall 2A. At this time, the first bent portion 5b is inserted between the engagement portion 4B and the parking gear 3 so that it is on the parking gear 3 side of the engagement surface 4b of the parking pole 4.

[0053] After inserting the support shaft 7 into the hole 2a, when the hand that had been compressing and deforming it is released, the return spring 5 expands in an attempt to restore its original shape, and the first bent portion 5b engages with the engagement surface 4b of the parking pole 4, pressing the pole body 4A against the stopper member 10, and the stopper portion 7A, which receives force from the second bent portion 5c, is pressed against the inclined surface 2b, completing the installation of the return spring 5.

[0054] Next, the effect of the mounting structure of the return spring 5 according to this embodiment will be described. In order to assemble the parking lock mechanism including the parking pole 4, the return spring 5, etc., to the transmission case 2, the transmission case 2 is placed so that the axial direction of the support shaft 7 is in the vertical direction.

[0055] The mounting structure of the return spring 5 in this embodiment is provided on the transmission case 2 and has a return spring 5 that biases the parking pole 4 in a direction away from the parking gear 3.

[0056] The return spring 5 is wound spirally and has a winding portion 5A into which the support shaft 7 is inserted, a first arm portion 5B extending outward from the winding start end of the winding portion 5A and having a tip portion which engages with the parking pole 4, and a second arm portion 5C extending outward from the winding end end of the winding portion 5A and having a tip portion which engages with a stopper portion 7A of the support shaft 7.

[0057] The support shaft 7 has an axis portion 7B that is inserted into the wound portion 5A of the return spring 5, and a stopper portion 7A that protrudes radially from the axis portion 7B and engages with the tip portion of the second arm portion 5C, and the support shaft 7 is inserted rotatably into a hole portion 2a formed in the transmission case 2.

[0058] This allows the stopper portion 7A to support the second arm portion 5C, which is one side of the return spring 5. Therefore, the worker can hold the first arm portion 5B, which is the other side of the return spring 5, and insert the support shaft 7 from above into the hole portion 2a while engaging the first bent portion 5b with the engagement surface 4b of the parking pole 4.

[0059] In other words, by inserting the support shaft 7 into the hole 2a and engaging the first bent portion 5b with the engagement surface 4b of the parking pole 4, it is not necessary to compressively elastically deform the return spring 5 by, for example, strongly pushing the second bent portion 5c, but by rotating the support shaft 7 to move the stopper portion 7A, the return spring 5 can be compressed and elastically deformed. As a result, the workability of assembling the return spring 5 can be improved.

[0060] In addition, since the support shaft 7 is inserted into the hole portion 2a so as to be freely rotatable, by rotating the support shaft 7 relative to the hole portion 2a, the stopper portion 7A can be easily moved, and the return spring 5 can be easily compressed and elastically deformed.

[0061] Furthermore, the first bent portion 5b of the return spring 5 is bent downward from the first arm portion 5B, and the second bent portion 5c is bent upward from the second arm portion 5C.

[0062] This allows the tip of the second bent portion 5c to be positioned above the fixed point side (stopper portion 7A side) of the return spring 5, and the tip of the first bent portion 5b to be positioned below the tip of the second bent portion 5c on the load point side (parking pole 4 side) of the return spring 5.

[0063] Therefore, the second bent portion 5c, which receives a force from the stopper portion 7A located above the winding portion 5A, causes the second arm portion 5C to twist (elastically deform) by receiving the force at its upper end.

[0064] Since the second arm portion 5C is torsionally deformed, the second bent portion 5c is inclined obliquely, and a vertical component force is generated from the restoring force (horizontal force) of the return spring 5. This component force becomes a reaction force F1 (see FIG. 3) that directs the return spring 5 downward from the stopper portion 7A, and urges the return spring 5 toward the partition wall 2A.

[0065] The first bent portion 5b, which receives a reaction force from the parking pole 4, abuts against the engagement surface 4b relatively entirely, and therefore does not cause torsional deformation in the first arm portion 5B and maintains its posture relatively without tilting, so that the reaction force F2 (see Figure 3) directed upward from the parking pole 4 can be kept relatively small.

[0066] This makes it possible to cancel out the axial forces of the support shaft 7 received from the load point and fixed point of the return spring 5, thereby preventing the return spring 5 from moving up and down relative to the support shaft 7 and preventing the return spring 5 from coming off the support shaft 7. As a result, the workability of assembling the return spring 5 can be more effectively improved.

[0067] Furthermore, according to the mounting structure of the return spring 5 of this embodiment, the side wall 2B of the transmission case 2 has the inclined surface 2b, and the rotation of the support shaft 7 is restricted by the stopper portion 7A abutting against the inclined surface 2b.

[0068] This makes it possible to restrict the rotation of the support shaft 7 with a simple structure, making it possible to easily adjust the amount of compressive elastic deformation of the return spring 5, and more effectively improving the efficiency of assembling the return spring 5.

[0069] The rotation restricting portion may be formed of a protrusion 2c instead of the inclined surface 2b. Specifically, as shown in Fig. 4, a protrusion 2c protruding from the side wall 2B of the transmission case 2 toward the support shaft 7 may be formed on the side wall 2B, and the stopper portion 7A may be brought into contact with the protrusion 2c to restrict the rotation of the support shaft 7. In this way, the stopper portion 7A can be positioned accurately as designed.

[0070] In addition, a bulge portion (not shown) that bulges out from the side wall 2B of the transmission case 2 may be provided on the side wall 2B, and the bulge portion may be positioned above the stopper portion 7A when the stopper portion 7A abuts against the inclined surface 2b or the convex portion 2c.

[0071] In this way, when the support shaft 7 attempts to come out of the hole portion 2a, the stopper portion 7A of the support shaft 7 abuts the bulge portion to prevent the support shaft 7 from moving further, thereby preventing the support shaft 7 from coming out.

[0072] When the transmission 1 is mounted on a vehicle, the axis of the support shaft 7 extends in the left-right direction, and the return spring 5 is located above the parking pole 4.

[0073] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made therein without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0074] 1. Transmission (vehicle transmission) 2 Transmission case 2a hole 2b Inclined surface (rotation restriction part) 2c Convex part (rotation restriction part) 3 Parking Gear 4 Parking Pole 5 Return spring 5A Winding section 5B First arm 5C Second arm 7 Support shaft 7A Stopper part 7B Shaft

Claims

1. A mounting structure for a return spring provided in a transmission case and biasing a parking pole in a direction to disengage from a parking gear, the return spring is wound in a spiral shape and has a winding portion into which a support shaft is inserted, a first arm portion that extends outward from a winding start end of the winding portion and has a tip portion that engages with the parking pole, and a second arm portion that extends outward from a winding end end of the winding portion and has a tip portion that engages with a stopper portion of the support shaft, the support shaft has a shaft portion that is inserted into the wound portion of the return spring, and the stopper portion that protrudes radially from the shaft portion and is engaged with a tip end portion of the second arm portion, The return spring mounting structure is characterized in that the support shaft is rotatably inserted into a hole formed in the transmission case.

2. The transmission case has a rotation restricting portion, 2. The mounting structure of the return spring according to claim 1, wherein the rotation of the support shaft is restricted by the stopper portion coming into contact with the rotation restricting portion.

3. The rotation restricting portion has a protrusion protruding from a wall portion of the transmission case, 3. The mounting structure for a return spring according to claim 2, wherein the stopper portion abuts against the protrusion, thereby restricting rotation of the support shaft.

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