Shift mechanism

Abstract

To provide a shift mechanism that can be miniaturized without impairing manufacturability.SOLUTION: A shift mechanism includes a shift fork, a shift fork shaft, and a cam follower. The cam follower includes a large diameter part and a small diameter part. The cam follower and the shift fork are interference fitted and fixed at the large diameter part. The cam follower and the shift fork are loosely fitted and fixed at the small diameter part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a shifting mechanism. [Background technology]

[0002] Patent Document 1 discloses a shift mechanism in which a shift fork is fixed to a shift fork shaft, and the shift fork and cam follower are integrally formed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-054736 Summary of the Invention [Problem to be solved by the invention]

[0004] The shift mechanism disclosed in Patent Document 1 has a problem with manufacturability because the shift fork and cam follower are integrally formed. Furthermore, if the shift fork and cam follower are not integrally formed, it would be necessary to fix the cam follower and shift fork together at two locations on the shift fork shaft, for example, and to fix the shift fork and shift fork shaft together. This would increase the space occupied and the size of the shift mechanism.

[0005] The present disclosure has been made in view of the above, and has an object to provide a shift mechanism that can be made smaller without compromising manufacturability. [Means for solving the problem]

[0006] A shift mechanism according to the present disclosure includes a shift fork, a shift fork shaft, and a cam follower, wherein the cam follower has a large diameter portion and a small diameter portion, the cam follower and the shift fork are fixed together by an interference fit at the large diameter portion, and the cam follower and the shift fork shaft are fixed together by a clearance fit at the small diameter portion. [Effects of the Invention]

[0007] According to the present disclosure, miniaturization can be achieved without impairing manufacturability. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing the configuration of a shift mechanism according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of the shift mechanism according to the embodiment, and is an enlarged view of the periphery of the cam follower in FIG. [Figure 3] FIG. 3 is a cross-sectional view showing the configuration of a modified example of the shift mechanism according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view showing the configuration of a conventional shift mechanism. [Figure 5] FIG. 5 is a cross-sectional view showing the configuration of a conventional shift mechanism, and is an enlarged view of the periphery of the cam follower in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] A shift mechanism according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical.

[0010] The shift mechanism according to the embodiment is a mechanism used in a transmission of a vehicle. The shift mechanism 1 includes a shift fork 11, a shift fork shaft 12, and a cam follower 13, as shown in FIG.

[0011] The shift fork 11 is provided with holes 11a and 11b. The hole 11a is provided in a direction perpendicular to the axial direction of the shift fork 11. A shift fork shaft 12 is inserted into the hole 11a. The hole 11b is provided in a direction parallel to the axial direction of the shift fork 11. A cam follower 13 is inserted into the hole 11b. The hole 11b has a larger diameter than the hole 12a of the shift fork shaft 12. The center of the hole 11b is positioned to coincide with the center of the hole 12a.

[0012] A hole 12a is formed in the shift fork shaft 12. The hole 12a is formed in a direction perpendicular to the axial direction of the shift fork shaft 12. A cam follower 13 is inserted into this hole 12a. The hole 12a is formed to have a smaller diameter than the hole 11b of the shift fork 11.

[0013] Cam follower (cam follower pin) 13 is a member that receives a load due to the driving force of the vehicle. Cam follower 13 is formed in a pin shape with a step. Cam follower 13 is inserted into hole 11b of shift fork 11 and hole 12a of shift fork shaft 12. Cam follower 13 has a large diameter portion 131 and a small diameter portion 132, as shown in FIG. 2 .

[0014] Large diameter portion 131 of cam follower 13 is formed to have a diameter larger than hole portion 11b of shift fork 11. Large diameter portion 131 is inserted into hole portion 11b. That is, cam follower 13 and shift fork 11 are fixed to each other by interference fit at large diameter portion 131.

[0015] The small diameter portion 132 of the cam follower 13 is formed to have a smaller diameter than the hole portion 12a of the shift fork shaft 12. The small diameter portion 132 is inserted into the hole portion 12a. That is, the cam follower 13 and the shift fork shaft 12 are fixed to each other at the small diameter portion 132 by clearance fit.

[0016] 4 and 5. The shift mechanism 101 includes a shift fork 111, a shift fork shaft 112, a cam follower 113, and a fixing pin 114.

[0017] The shift fork 111 is provided with holes 111a, 111b, and 111c. A shift fork shaft 112 is inserted into the hole 111a. A cam follower 113 is inserted into the hole 111b. A fixing pin 114 is inserted into the hole 111c. The shift fork shaft 112 is provided with a hole 112a. The fixing pin 114 is inserted into the hole 112a.

[0018] In shift mechanism 101 having such a configuration, "fixing of cam follower 113 to shift fork 111" and "fixing of shift fork 111 to shift fork shaft 112" are performed at two locations on the axis of shift fork shaft 112. This increases the space occupied, and the size of shift mechanism 101 increases.

[0019] Therefore, in the shift mechanism according to this embodiment, as shown in Fig. 2, the large diameter portion 131 of the cam follower 13 is inserted into the hole portion 11b of the shift fork 11 and fixed by an interference fit. Also, the small diameter portion 132 of the cam follower 13 is inserted into the hole portion 12a of the shift fork shaft 12 and fixed by a clearance fit. This allows the "fixing of the cam follower 13 to the shift fork 11" and the "fixing of the shift fork 11 to the shift fork shaft 12" to be performed at one location on the axis of the shift fork shaft 12. As a result, an increase in the occupied space and an increase in the size of the shift mechanism 101 can be suppressed.

[0020] Note that the force from cam follower 13 is transmitted to large diameter portion 131 of cam follower 13, which is an interference fit, and it is sufficient for small diameter portion 132 to bear a load equivalent to only the inertial mass of shift fork shaft 12. Therefore, the above structure is also valid for small cam follower 13.

[0021] Here, the method of fixing the shift fork 11, the shift fork shaft 12, and the cam follower 13 is not limited to the method shown in Figures 1 and 2. For example, as shown in Figure 3, the cam follower 13 and the shift fork 11 may be fixed by clearance fit at the large diameter portion 131, and the cam follower 13 and the shift fork shaft 12 may be fixed by screw fastening at the small diameter portion 132.

[0022] In this case, the diameter of large diameter portion 131 of cam follower 13 is formed to be smaller than the diameter of hole 11b of shift fork 11. In addition, the diameter of small diameter portion 132 of cam follower 13 is formed to be the same size as the diameter of hole 12a of shift fork shaft 12, and threads are provided on the outer periphery of small diameter portion 132 and the inner periphery of hole 12a. Force is transmitted from cam follower 13 to small diameter portion 132 of cam follower 13, which is fastened by screws.

[0023] In the configuration shown in FIG. 3 , the “fixing of the cam follower 13 to the shift fork 11” and the “fixing of the shift fork 11 to the shift fork shaft 12” can be performed at one location on the axis of the shift fork shaft 12.

[0024] In the shift mechanism according to the embodiment described above, the cam follower 13 is formed with a large diameter portion 131 and a small diameter portion 132, which are engaged with both the shift fork 11 and the shift fork shaft 12, thereby eliminating the need for a conventional fixing pin (fixing pin 114 in FIG. 4). This makes it possible to reduce the size of the entire shift mechanism without compromising manufacturability. In other words, it is possible to achieve a shift fork 11 that is smaller than the conventional one (see FIG. 4).

[0025] In the shift mechanism according to the embodiment, cam follower 13 is extended with a stepped structure, and hole 12a is formed in shift fork shaft 12. Cam follower 13 and shift fork 11 are fixed together by an interference fit, and cam follower 13 and shift fork shaft 12 are fixed together by a clearance fit, thereby also serving to fix shift fork 11 and shift fork shaft 12 together.

[0026] This makes it possible to transmit force from cam follower 13 to shift fork 11 and fix shift fork 11 and shift fork shaft 12 in a limited space on the axis of shift fork shaft 12.

[0027] Further advantages and modifications will readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0028] 1,101 Shift mechanism 11,111 Shift fork 11a,11b,111a,111b,111c Hole 12,112 Shift fork shaft 12a hole 13,113 Cam Follower 114 Fixing pin 131 Large diameter section 132 Small diameter section

Claims

[Claim 1] Shift forks and A shift fork shaft, Cam followers and Equipped with the cam follower has a large diameter portion and a small diameter portion, The cam follower and the shift fork are fixed to each other by interference fit at the large diameter portion, The cam follower and the shift fork shaft are fixed to each other by clearance fit at the small diameter portion. Shift mechanism.

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