Transmission mechanism for work machine, shift fork, and method of manufacturing shift fork

Abstract

To reduce manufacturing costs of a shift fork having a pair of arms.SOLUTION: A transmission mechanism 10 is provided with: a countershaft 32 and a shift shaft 56 that are parallel to one another; a first coupling sleeve 41 and a second coupling sleeve 42 that can be displaced along the countershaft 32; and a shift fork 50 comprising a sleeve 53 that can be displaced along the shift shaft 56, a first arm 51 that engages with the first coupling sleeve 41, and a second arm 52 that engages with the second coupling sleeve 42. The shift fork 50 is configured by joining a first member 50A and a second member 50B together. The first member 50A includes: a first sleeve 53A constituting one axial side of the sleeve 53, and the first arm 51 provided at the first sleeve 53A. The second member 50B includes a second sleeve 53B constituting the other axial side of the sleeve 53, and the second arm 52 provided at the second sleeve 53B.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a transmission mechanism of a working machine, a shift fork, and a method for manufacturing the shift fork.

Background Art

[0002] Conventionally, a transmission mechanism (transmission) for a working machine shown in Patent Document 1 has been known. The transmission mechanism includes a sub-transmission mechanism including a pair of coupling sleeves. The sub-transmission mechanism can select a gear stage corresponding to its displacement position by synchronously displacing the pair of coupling sleeves. The sub-transmission mechanism further includes a shift fork for displacing the pair of coupling sleeves. The shift fork includes a first arm engaged with one coupling sleeve, a second arm engaged with the other coupling sleeve, and a cylindrical sleeve connecting both arms. The shift fork having such a configuration can synchronously displace the pair of arms by displacing the sleeve. Note that the working machine shown in Patent Document 1 is a combine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When manufacturing the shift fork having a pair of arms by casting, it is necessary to use a complicated mold having two or more drawing directions. In other words, it is difficult to manufacture the shift fork using a simple mold having a single drawing direction. For this reason, it is difficult to suppress the cost of the shift fork having a pair of arms.

[0005] The present disclosure aims to suppress the manufacturing cost of a shift fork having a pair of arms.

Means for Solving the Problems

[0006] The transmission mechanism of the working machine of the present disclosure includes a first shaft and a second shaft parallel to each other, a first coupling sleeve and a second coupling sleeve displaceable along the first shaft, a sleeve displaceable along the second shaft, a first arm provided on the sleeve and engaging with the first coupling, and a shift fork having a second arm provided on the sleeve and engaging with the second coupling sleeve. The shift fork is configured by coupling a first member constituting one axial side and a second member constituting the other axial side. The first member includes a first sleeve constituting one axial side of the sleeve and the first arm provided on the first sleeve. The second member includes a second sleeve constituting the other axial side of the sleeve and the second arm provided on the second sleeve.

Advantages of the Invention

[0007] According to the present disclosure, the manufacturing cost of a shift fork having a pair of arms can be suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 4C

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0009] <Summary of Embodiments of the Present Disclosure> Hereinafter, a summary of embodiments of the invention of the present disclosure will be listed and described. (1) The transmission mechanism of the working machine of the present disclosure includes a first shaft and a second shaft parallel to each other, a first coupling sleeve and a second coupling sleeve displaceable along the first shaft, a sleeve displaceable along the second shaft, a first arm provided on the sleeve and engaging with the first coupling, and a shift fork having a second arm provided on the sleeve and engaging with the second coupling sleeve. The shift fork is configured by coupling a first member constituting one side in the axial direction and a second member constituting the other side in the axial direction. The first member includes a first sleeve constituting one side in the axial direction of the sleeve and the first arm provided on the first sleeve. The second member includes a second sleeve constituting the other side in the axial direction of the sleeve and the second arm provided on the second sleeve.

[0010] According to the above configuration, the first member and the second member can be manufactured using a simple mold with the extraction direction being one direction, and the shift fork can be manufactured using the first member and the second member. Thereby, the manufacturing cost of the shift fork having a pair of arms can be suppressed.

[0011] (2) In the transmission mechanism of the working machine according to the form of (1) above, the first sleeve has a first coupling portion for coupling the second member, and the second sleeve has a second coupling portion for coupling the first member. It is preferable that the first coupling portion and the second coupling portion are coupled to each other. According to the above configuration, the first member and the second member can be coupled without using a separate coupling member. Thereby, the manufacturing cost of the shift fork constituted by coupling the first member and the second member can be suppressed.

[0012] (3) In the transmission mechanism of the working machine according to the form of (1) or (2) above, the first coupling portion has a first convex portion that protrudes in the radial direction of the first sleeve, and a first concave portion that recesses in a direction opposite to the convex direction of the first convex portion. The second coupling portion preferably has a second convex portion that protrudes in the radial direction of the second sleeve and fits into the first concave portion, and a second concave portion that recesses in a direction opposite to the convex direction of the second convex portion and fits into the first convex portion. According to the above configuration, the force acting on one side and the other side in the axial direction can be reliably transmitted to the first coupling sleeve and the second coupling sleeve by the shift fork constituted by the first member and the second member. Thereby, it becomes possible to reliably displace the first coupling sleeve and the second coupling sleeve to one side and the other side in the axial direction.

[0013] (4) The transmission mechanism of the working machine according to the forms of (1) to (3) above further includes a shift mechanism for displacing the shift fork in the axial direction of the second shaft. The shift fork has an engaging portion that engages with the shift mechanism, and it is preferable that the engaging portion is provided on either one of the first member and the second member. According to the above configuration, in the shift fork constituted by the first member and the second member, the engaging portion can be easily provided.

[0014] (5) The transmission mechanism of the working machine according to any one of the forms (1) to (4) further includes a detent mechanism that holds the shift fork at a predetermined position in the axial direction of the second shaft. The detent mechanism includes a ball and an elastic member, and it is preferable that either one of the first member and the second member includes a housing portion that houses the ball and the elastic member. According to the above configuration, in the shift fork constituted by the first member and the second member, a detent mechanism can be easily provided.

[0015] (6) The shift fork of the present disclosure includes a sleeve through which a shaft is inserted, and a pair of arms provided on one axial side and the other axial side of the sleeve. The shift fork is configured by coupling a first member that constitutes one axial side and a second member that constitutes the other axial side. The first member includes a first sleeve that constitutes one axial side of the sleeve and the first arm provided on the first sleeve. The second member includes a second sleeve that constitutes the other axial side of the sleeve and the second arm provided on the second sleeve.

[0016] According to the above configuration, the shift fork can be manufactured using the first member and the second member that can be manufactured using a simple mold with the extraction direction being one direction. Thereby, the manufacturing cost of the shift fork having a pair of arms can be suppressed.

[0017] (7) In the shift fork according to the form (6), the first sleeve has a first coupling portion that couples the second member, the second sleeve has a second coupling portion that couples the first member, and it is preferable that the first coupling portion and the second coupling portion couple with each other. According to the above configuration, the first member and the second member can be coupled without using a separate coupling member. Thereby, the manufacturing cost of the shift fork constituted by coupling the first member and the second member can be suppressed.

[0018] (8) In the shift fork according to the form of the above (6) or (7), the first coupling portion is provided at the other end in the axial direction of the first sleeve, and has a first convex portion that protrudes in the radial direction of the first sleeve, and a first concave portion that is recessed in a direction opposite to the convex direction of the first convex portion. The second coupling portion is provided at one end in the axial direction of the second sleeve, and preferably has a second convex portion that protrudes in the radial direction of the second sleeve and fits with the first concave portion, and a second concave portion that is recessed in a direction opposite to the convex direction of the second convex portion and fits with the first convex portion. According to the above configuration, the first member and the second member can be reliably coupled with a simple configuration.

[0019] (9) In the shift fork according to any one of the above (6) to (8), the first coupling portion has a first surface that is the side surface on the other side in the axial direction of the first convex portion, a second surface that is the side surface on one side in the axial direction of the first convex portion and is also the side surface on the other side in the axial direction of the first concave portion, and a third surface that is the side surface on one side in the axial direction of the first concave portion. The second coupling portion has a fourth surface that is the side surface on one side in the axial direction of the second convex portion, a fifth surface that is the side surface on the other side in the axial direction of the second convex portion and is also the side surface on one side in the axial direction of the second concave portion, and a sixth surface that is the side surface on the other side in the axial direction of the second concave portion. It is preferable that the first surface and the sixth surface, the second surface and the fifth surface, and the third surface and the fourth surface face each other respectively. According to the above configuration, the force acting on one side and the other side in the axial direction can be reliably transmitted by the shift fork composed of the first member and the second member.

[0020] (10) In the shift fork according to any one of the above (6) to (9), it is preferable that the first member and the second member have the same shape. According to the above configuration, the number of parts of the shift fork formed by coupling the first member and the second member can be reduced, and thereby the manufacturing cost of the shift fork can be suppressed.

[0021] (11) The manufacturing method of the present disclosure is a manufacturing method of a shift fork including a sleeve through which a shaft is inserted and a pair of arms provided on one axial side and the other axial side of the sleeve. The manufacturing method of the shift fork of the present disclosure includes a first step of creating a common original member that serves as the basis for a first member constituting one axial side of the shift fork and a second member constituting the other axial side, and processing the original member to create the first member including a first sleeve constituting one axial side of the sleeve and the first arm provided on the first sleeve, and a second member including a second sleeve constituting the other axial side of the sleeve and the second arm provided on the second sleeve.

[0022] According to the above configuration, the first member and the second member can be created from an original member that can be manufactured using a simple mold with a single extraction direction, and the shift fork can be manufactured using these. Thereby, the manufacturing cost of the shift fork having a pair of arms can be suppressed.

[0023] (12) In the manufacturing method of the shift fork according to the form of (11) above, the first member has a first coupling portion for coupling the second member, the second member has a second coupling portion for coupling the first member, the original member has a portion to be processed that is processed into the first coupling portion or the second coupling portion, and the second step preferably includes a step of performing a first processing on the portion to be processed to create the first member and a step of performing a second processing on the portion to be processed to create the second member. According to the above configuration, only one type of simple mold with a single extraction direction is used to manufacture only one type of original member, and the first member is manufactured by performing a first processing on this original member, and the second member can be manufactured by performing a second processing. Thereby, the manufacturing cost of the shift fork having a pair of arms can be suppressed.

[0024] (13) In the method for manufacturing a shift fork according to the form of the above (11) or (12), the original member further has a second machined part that is machined on an engaging part that engages with a shift mechanism for axially displacing the sleeve, and it is preferable that either one of the first machining and the second machining includes machining for removing at least a part of the second machined part. According to the above configuration, in a shift fork manufactured from one type of original member, an engaging part can be easily provided.

[0025] (14) In the method for manufacturing a shift fork according to the form of the above (11) or (12), the first machining and the second machining are the same machining, and it is preferable that the first member and the second member have the same shape. According to the above configuration, an original member can be manufactured using a simple mold in which the drawing direction is one direction, and the first member and the second member can be manufactured from this original member. Thereby, the manufacturing cost of a shift fork having a pair of arms can be suppressed.

[0026] (15) In the method for manufacturing a shift fork according to any one of the above (11) to (14), it is preferable that the first step includes a step of creating the original member by casting. According to the above configuration, an original member can be manufactured using a simple mold in which the drawing direction is one direction, the first member can be manufactured by subjecting this original member to the first machining, and the second member can be manufactured by subjecting it to the second machining, thereby manufacturing a shift fork. Thereby, the manufacturing cost of a shift fork having a pair of arms can be suppressed.

[0027] <Details of Embodiments of the Invention of the Present Disclosure> Hereinafter, with reference to the drawings, the details of the embodiments of the present disclosure will be described. Note that at least a part of the embodiments described below may be arbitrarily combined.

[0028] 〔Overall Configuration of Transmission Mechanism〕 FIG. 1 is a skeleton diagram showing a transmission mechanism of a working machine according to an embodiment of the present disclosure. FIG. 2 is a partially enlarged view showing a sub-transmission mechanism. FIG. 1 shows a transmission mechanism 10 according to an embodiment of the transmission mechanism of the working machine of the present disclosure. The transmission mechanism 10 shown in the present embodiment is a transmission mechanism (transmission) for a combine, which is an example of a working machine. As shown in FIG. 1, the transmission mechanism 10 includes a main transmission mechanism 20, a sub-transmission mechanism 30, a clutch mechanism 60, a drive mechanism 70, and a shift mechanism 80. Note that the transmission mechanism of the working machine of the present disclosure may be a transmission mechanism for a working machine other than a combine.

[0029] [Main transmission mechanism] In the transmission mechanism 10 of the present embodiment, the main transmission mechanism 20 is constituted by a hydrostatic continuously variable transmission (HST). The main transmission mechanism 20 includes an input shaft 21 and an output shaft 22. The main transmission mechanism 20 adjusts the driving force (rotational force) input from a prime mover such as an engine via the input shaft 21 by a planetary gear mechanism (not shown) or the like, and outputs it from the output shaft 22 after adjusting the rotational speed, rotational direction, etc. Note that the main transmission mechanism in the transmission mechanism of the present disclosure is not limited to such a configuration.

[0030] [Sub-transmission mechanism] The sub-transmission mechanism 30 further shifts (adjusts the rotational speed) the driving force output from the main transmission mechanism 20. As shown in FIG. 2, the sub-transmission mechanism 30 is housed inside the transmission case 11. As shown in FIGS. 1 and 2, the sub-transmission mechanism 30 includes an input shaft 31 and a counter shaft 32. The input shaft 31 is coaxially connected to the output shaft 22 and rotates integrally with the output shaft 22. The input shaft 31 includes an input gear 33 including a low-speed gear 33a, a high-speed gear 33b, and a medium-speed gear 33c. The low-speed gear 33a, the high-speed gear 33b, and the medium-speed gear 33c are fixed on the axis of the input shaft 31. The low-speed gear 33a, the high-speed gear 33b, and the medium-speed gear 33c rotate integrally with the input shaft 31 (output shaft 22).

[0031] The auxiliary transmission mechanism 30 further includes a first coupling sleeve 41 and a second coupling sleeve 42. The first coupling sleeve 41 and the second coupling sleeve 42 are configured to be displaceable along the countershaft 32 (in other words, in the axial direction of the countershaft 32). The auxiliary transmission mechanism 30 selects a gear stage (any one of low speed, medium speed, high speed, and neutral) according to the displacements of the first coupling sleeve 41 and the second coupling sleeve 42. The first coupling sleeve 41 and the second coupling sleeve 42 are synchronously displaced along the countershaft 32 according to the displacement of a shift fork 50, which will be described later.

[0032] The countershaft 32 is arranged parallel to the input shaft 31. The countershaft 32 includes a first gear 34, a second gear 35, a third gear 36, a first coupling gear 37, a second coupling gear 38, and a counter gear 39.

[0033] The first gear 34 includes a first input-side gear 34a, a first output-side gear 34b, and a first gear shaft 34c. The first gear shaft 34c is cylindrical and rotatably supported on the countershaft 32. The first input-side gear 34a meshes with the low-speed gear 33a. The first output-side gear 34b is configured to be meshed with the first coupling sleeve 41.

[0034] The second gear 35 includes a second input-side gear 35a, a second output-side gear 35b, and a second gear shaft 35c. The second gear shaft 35c is cylindrical and rotatably supported on the countershaft 32. The second input-side gear 35a meshes with the high-speed gear 33b. The second output-side gear 35b is configured to be meshed with the first coupling sleeve 41.

[0035] The third gear 36 is composed of a third input-side gear 36a, a third output-side gear 36b, and a third gear shaft 36c. The third gear shaft 36c is cylindrical and is rotatably supported on the counter shaft 32. The third input-side gear 36a meshes with the medium-speed gear 33c. The third output-side gear 36b is configured to be meshed with the second coupling sleeve 42.

[0036] The first coupling gear 37, the second coupling gear 38, and the counter gear 39 are fixed on the axis of the counter shaft 32. The first coupling gear 37, the second coupling gear 38, and the counter gear 39 rotate integrally with the counter shaft 32.

[0037] The first coupling sleeve 41 is configured to be displaceable along the counter shaft 32 within the axial range where the first output-side gear 34b, the first coupling gear 37, and the second output-side gear 35b are located. The first coupling gear 37 is arranged adjacent to the first output-side gear 34b. The first coupling gear 37 and the first output-side gear 34b are configured to be meshed with the first coupling sleeve 41. When the first coupling sleeve 41 is displaced to a position straddling the first coupling gear 37 and the first output-side gear 34b, the first coupling gear 37 and the first output-side gear 34b are connected by the first coupling sleeve 41. At this time, the first gear 34 can rotate integrally with the counter gear 39, and the driving force transmitted from the low-speed gear 33a to the first gear 34 is transmitted to the counter shaft 32 via the first coupling gear 37. At this time, the auxiliary transmission mechanism 30 is in a state where "low speed" is selected. When the first coupling sleeve 41 is displaced to a position other than the position straddling the first coupling gear 37 and the first output-side gear 34b, the first coupling gear 37 and the first output-side gear 34b are disengaged. At this time, the first coupling gear 37 and the first output-side gear 34b are in a state where they are not involved in the transmission of the driving force.

[0038] The first coupling gear 37 is further arranged adjacent to the second output side gear 35b. The second output side gear 35b is configured to be meshed with the first coupling sleeve 41. When the first coupling sleeve 41 is displaced to a position straddling the first coupling gear 37 and the second output side gear 35b, the first coupling gear 37 and the second output side gear 35b are connected by the first coupling sleeve 41. At this time, the second gear 35 can rotate integrally with the counter gear 39, and the driving force transmitted from the high-speed gear 33b to the second gear 35 is transmitted to the counter shaft 32 via the first coupling gear 37. At this time, the auxiliary transmission mechanism 30 is in a state of selecting "high speed". When the first coupling sleeve 41 is displaced to a position other than the position straddling the first coupling gear 37 and the second output side gear 35b, the first coupling gear 37 and the second output side gear 35b are disengaged and are in a state not involved in the transmission of the driving force.

[0039] The second coupling sleeve 42 is configured to be displaceable along the counter shaft 32 within the axial range where the third output side gear 36b and the second coupling gear 38 are present. The second coupling gear 38 is arranged adjacent to the third output side gear 36b. The second coupling gear 38 and the third output side gear 36b are configured to be meshed with the second coupling sleeve 42. When the second coupling sleeve 42 is displaced to a position straddling the second coupling gear 38 and the third output side gear 36b, the second coupling gear 38 and the third output side gear 36b are connected by the second coupling sleeve 42. At this time, the third gear 36 can rotate integrally with the counter gear 39, and the driving force transmitted from the medium-speed gear 33c to the third gear 36 is transmitted to the counter shaft 32 via the second coupling gear 38. At this time, the auxiliary transmission mechanism 30 is in a state of selecting "medium speed". When the second coupling sleeve 42 is displaced to a position other than the position straddling the second coupling gear 38 and the third output side gear 36b, the second coupling gear 38 and the third output side gear 36b are disengaged and are in a state not involved in the transmission of the driving force.

[0040] The auxiliary transmission mechanism 30 thus shifts the driving force according to the positions of the first coupling sleeve 41 and the second coupling sleeve 42, and outputs it from the counter gear 39. When the first coupling sleeve 41 and the second coupling sleeve 42 are arranged at positions that do not straddle two gears, the auxiliary transmission mechanism 30 is in a state where "neutral" is selected. At this time, the auxiliary transmission mechanism 30 is in a state (so-called neutral state) where the driving force input to the input shaft 31 is not output from the counter shaft 32.

[0041] [Clutch mechanism] The clutch mechanism 60 is a mechanism that selectively transmits the driving force output from the auxiliary transmission device 30 to the left and right drive mechanisms 70. The clutch mechanism 60 includes an input gear 62 fixed on the input shaft 61, a pair of left and right side clutches 63 (a first side clutch 63a and a second side clutch 63b), and a pair of left and right side gears 64 (a first side gear 64a and a second side gear 64b). The left and right side clutches 63a and 63b are fixed on the input shaft 61. When the first side clutch 63a operates, the first side clutch 63a and the first side gear 64a are connected, and the driving force can be transmitted. At this time, the first side clutch 63a transmits the driving force to the drive mechanism 70 via the first side gear 64a. When the second side clutch 63b operates, the second side clutch 63b and the second side gear 64b are connected, and the driving force can be transmitted. At this time, the second side clutch 63b transmits the driving force to the drive mechanism 70 via the second side gear 64b.

[0042] [Drive mechanism] The drive mechanism 70 transmits the driving force transmitted from the clutch mechanism 60 to a traveling device (not shown) of the working machine. The transmission mechanism 10 of the present embodiment is for a combine, and the drive mechanism 70 drives the crawler-type traveling device. The drive mechanism 70 includes a pair of left and right drive shafts 71 (a first drive shaft 71a and a second drive shaft 71b), a pair of left and right drive gears 72 (a first drive gear 72a and a second drive gear 72b) fixed on the drive shafts 71, and a pair of left and right drive wheels (sprocket) 73 (a first drive wheel 73a and a second drive wheel 73b). The drive wheel 73 drives an endless crawler (not shown). Note that the drive mechanism 70 may further include a brake mechanism (not shown) for adjusting the driving forces of the left and right drive shafts 71 (the first drive shaft 71a and the second drive shaft 71b).

[0043] When the driving force is transmitted from the clutch mechanism 60 to the first drive gear 72a, the drive mechanism 70 drives the first drive wheel 73a via the first drive shaft 71a. When the driving force is transmitted from the clutch mechanism 60 to the second drive gear 72b, the drive mechanism 70 drives the second drive wheel 73b via the second drive shaft 71b.

[0044] When both the left and right side clutches 63a and 63b in the clutch mechanism 60 are in the engaged state, the transmission mechanism 10 can rotationally drive the pair of left and right traveling devices at the same speed. Thereby, the working machine (combine) can travel straight. Also, when only one of the first side clutch 63a and the second side clutch 63b is in the engaged state, the transmission mechanism 10 can change the direction of the working machine (combine) to either the left or the right direction.

[0045] [Shift mechanism] The shift mechanism 80 is a mechanism for selecting a gear stage in the auxiliary transmission mechanism 30. The shift mechanism 80 of the present embodiment includes a sub-shift lever 81. The sub-shift lever 81 is rotatably supported by a rotation shaft 82 and is disposed near the driver's seat of a work machine (not shown). The transmission mechanism 10 can select the gear stage of the auxiliary transmission mechanism 30 by a rotation operation of the sub-shift lever 81 by a user sitting on the driver's seat. The end portion 83 of the sub-shift lever 81 engages with the shift fork 50. The sub-shift lever 81 displaces the shift fork 50 along the shift shaft 56 (in the axial direction) by its rotation. The auxiliary transmission mechanism 30 is configured to be able to select a gear stage (any one of low speed, high speed, medium speed, and neutral) by displacing the shift fork 50 according to the rotation position of the sub-shift lever 81.

[0046] [Shift fork] As shown in FIGS. 1 and 2, the auxiliary transmission mechanism 30 includes a shift fork 50. As shown in FIGS. 1 and 2, the shift fork 50 includes a first arm 51, a second arm 52, and a sleeve 53. That is, the shift fork 50 in the transmission mechanism 10 of the present disclosure has a structure in which the first arm 51 and the second arm 52 are connected by the sleeve 53.

[0047] The sleeve 53 has a shaft hole 54. The shift shaft 56 is inserted into the shaft hole 54 of the shift fork 50. The shift shaft 56 is supported by the transmission case 11 in a posture parallel to the countershaft 32. The shift fork 50 includes an engaging portion 55. The engaging portion 55 has a groove portion 55a which is a portion where the end portion 83 of the sub-shift lever 81 is engaged. The shift fork 50 is configured to be displaceable along the shift shaft 56 (in the axial direction of the shift shaft 56). Note that the configuration of the shift fork 50 will be described in detail later.

[0048] [Detent mechanism] The sub-transmission mechanism 30 further includes a detent mechanism 59. The detent mechanism 59 is a mechanism that holds the shift fork 50 at a predetermined position in the axial direction of the shift shaft 56. The detent mechanism 59 includes a ball 59a, an elastic member 59b, a housing portion 59c formed in the sleeve 53, and a ring-shaped groove portion 56a formed on the outer peripheral surface of the shift shaft 56. The groove portion 56a is formed in accordance with the arrangement of each housing portion 59c when the sub-shift lever 81 is rotated to each position of low speed, high speed, medium speed, and neutral. For example, when the sub-shift lever 81 is rotated to the low-speed position, the detent mechanism 59 arranges the housing portion 59c (the ball 59a and the elastic member 59b) at the position corresponding to the low speed. At this time, the ball 59a fits into the groove portion 56a formed at the low-speed position, and the ball 59a is pressed by the elastic member 59b. In this way, the detent mechanism 59 holds the shift fork 50 at the low-speed position. The detent mechanism 59 operates in the same manner when the sub-shift lever 81 is rotated to a position other than the low speed. Note that the detent mechanism 59 allows displacement of the shift fork 50 in the axial direction when a force equal to or greater than a predetermined force acts on the shift fork 50 in the axial direction of the shift shaft 56.

[0049] [Details of the Shift Fork Configuration] Figures 3A and 3B are schematic views showing the shift fork. Figures 4A and 4B are exploded perspective views showing the first member and the second member before assembly. Figure 4C is a perspective view showing the shift fork (the first member and the second member after assembly). Figure 5 is a partially enlarged view showing the first coupling portion and the second coupling portion. Note that Figure 3A shows the shift fork 50 when viewed from the same direction as Figure 2, and Figure 3B shows the shift fork 50 when viewed from the opposite side of Figure 3A. The perspective views of Figures 4A and 4B have different viewing angles and viewpoints for the shift fork 50. Figure 4C shows the shift fork 50 viewed from the same angle and viewpoint as Figure 4A.

[0050] The shift fork 50 that constitutes the transmission mechanism 10 of the present disclosure is configured by coupling a first member 50A and a second member 50B. As shown in FIGS. 3A, B and FIGS. 4A to C, the first member 50A is a member that constitutes one axial side of the shift fork 50, and the second member 50B is a member that constitutes the other axial side of the shift fork 50.

[0051] The shift fork 50 that constitutes the transmission mechanism 10 of the present disclosure includes a first arm 51, a second arm 52, and a sleeve 53. The sleeve 53 is constituted by a first sleeve 53A that constitutes one axial side and a second sleeve 53B that constitutes the other axial side. The first sleeve 53A has a first coupling portion 57. The first coupling portion 57 is formed at an end portion on the other axial side of the first sleeve 53A. The second sleeve 53B has a second coupling portion 58. The second coupling portion 58 is formed at an end portion on one axial side of the second sleeve 53B.

[0052] The first member 50A includes the first sleeve 53A, the first arm 51 provided on the first sleeve 53A, and the first coupling portion 57. The second member 50B includes the second sleeve 53B, the second arm 52 provided on the second sleeve 53B, and the second coupling portion 58.

[0053] The first member 50A and the second member 50B are integrally configured by coupling the first coupling portion 57 and the second coupling portion 58 to each other. Thereby, the shift fork 50 is constituted by the first member 50A and the second member 50B.

[0054] The first arm 51 includes a pair of claw portions 51a and 51b, an arm portion 51c, and a pair of ribs 51d. The pair of claw portions 51a and 51b are portions that engage with a groove portion 41a (see FIG. 2) formed on the outer peripheral surface of the first coupling sleeve 41. The first arm 51 engages with the groove portion 41a at two locations in the circumferential direction (the pair of claw portions 51a and 51b). The arm portion 51c has a double-arm shape that surrounds half of the outer peripheral surface of the first coupling sleeve 41 and supports the pair of claw portions 51a and 51b from the first sleeve 53A. The rib 51d is a portion that connects between the first sleeve 53A and the arm portion 51c and reinforces the strength of the arm portion 51c.

[0055] The second arm 52 includes a pair of claw portions 52a and 52b, an arm portion 52c, and a pair of ribs 52d. The pair of claw portions 52a and 52b are portions that engage with a groove portion 42a (see FIG. 2) formed on the outer peripheral surface of the second coupling sleeve 42. The second arm 52 engages with the groove portion 42a at two locations in the circumferential direction (the pair of claw portions 52a and 52b). The arm portion 52c has a double-arm shape that surrounds half of the outer peripheral surface of the second coupling sleeve 42 and supports the pair of claw portions 52a and 52b from the second sleeve 53B. The rib 52d is a portion that connects between the second sleeve 53B and the arm portion 52c and reinforces the strength of the arm portion 52c. Note that the rib 52d contributes to securing a space (accommodation portion 59c) for accommodating the detent mechanism 59 inside the second member 50B.

[0056] As shown in FIG. 2, the shift fork 50 engages the first arm 51 with the first coupling sleeve 41 (groove portion 41a) and engages the second arm 52 with the second coupling sleeve 42 (groove portion 42a), and the shift shaft 56 is inserted through the shaft hole 54. The shift shaft 56 is a shaft parallel to the counter shaft 32. The shift fork 50 (sleeve 53) is configured to be displaceable in the axial direction along the shift shaft 56. Then, the first coupling sleeve 41 and the second coupling sleeve 42 are synchronously displaced as the shift fork 50 is displaced in the direction (axial direction) along the shift shaft 56.

[0057] As shown in FIG. 5, the first coupling portion 57 has a first convex portion 57a and a first concave portion 57b. The first convex portion 57a is a portion that protrudes in the radial direction of the first sleeve 53A, and the first concave portion 57b is a portion that recesses in a direction opposite to the convex direction of the first convex portion 57a. The first convex portion 57a fits with a second concave portion 58b, which will be described later, of the second coupling portion 58. The first concave portion 57b fits with a second convex portion 58a, which will be described later, of the second coupling portion 58.

[0058] The second coupling portion 58 has a second convex portion 58a and a second concave portion 58b. The second convex portion 58a is a portion that protrudes in the radial direction of the second sleeve 53B and fits with the first concave portion 57b. The second concave portion 58b is a portion that recesses in a direction opposite to the convex direction of the second convex portion 58a and fits with the first convex portion 57a.

[0059] The first coupling portion 57 and the second coupling portion 58 are coupled to each other by fitting the first convex portion 57a and the second concave portion 58b with each other and fitting the second convex portion 58a and the first concave portion 57b with each other.

[0060] Thus, according to the shift fork 50 of the present embodiment, the first member 50A and the second member 50B can be coupled without using a separate coupling member (in other words, without increasing the number of parts). Thereby, the manufacturing cost of the shift fork 50 configured by coupling the first member 50A and the second member 50B can be suppressed.

[0061] The first coupling portion 57 further includes a first surface 57c, a second surface 57d, and a third surface 57e. The first surface 57c is a side surface on the other axial side of the first convex portion 57a. The second surface 57d is a side surface on one axial side of the first convex portion 57a and also a side surface on the other axial side of the first concave portion 57b. The third surface 57e is a side surface on one axial side of the first concave portion 57b.

[0062] The second coupling portion 58 further includes a fourth surface 58c, a fifth surface 58d, and a sixth surface 58e. The fourth surface 58c is a side surface on one axial side of the second convex portion 58a. The fifth surface 58d is a side surface on the other axial side of the second convex portion 58a and is also a side surface on one axial side of the second concave portion 58b. The sixth surface 58e is a side surface on the other axial side of the second concave portion 58b.

[0063] In the shift fork 50, the first surface 57c and the sixth surface 58e, the second surface 57d and the fifth surface 58d, and the third surface 57e and the fourth surface 58c are respectively opposed to each other. When a force in one axial direction acts on the engaging portion 55 provided on the first member 50A in the shift fork 50 having such a configuration, the second surface 57d presses the fifth surface 58d, whereby a force in one axial direction is surely transmitted to the second member 50B. Further, when a force in the other axial direction acts on the engaging portion 55 provided on the first member 50A in the shift fork 50 having such a configuration, the first surface 57c presses the sixth surface 58e, and the third surface 57e presses the fourth surface 58c, whereby a force in the other axial direction is surely transmitted to the second member 50B. For this reason, although the shift fork 50 is configured to be divided into the first member 50A and the second member 50B in the axial direction, the first coupling sleeve 41 and the second coupling sleeve 42 can be surely displaced in one axial direction and the other axial direction.

[0064] [Regarding the manufacturing method of the shift fork] FIG. 6 is an explanatory diagram of the manufacturing method of the first member. FIG. 7 is an explanatory diagram of the manufacturing method of the second member. As shown in FIGS. 6 and 7, the first member 50A and the second member 50B constituting the shift fork 50 of the present disclosure are manufactured from a common original member 150.

[0065] As shown in FIGS. 6 and 7, the original member 150 includes an arm portion 151 that is the origin of the first arm 51 and the second arm 52, a sleeve portion 153 that is the origin of the first sleeve 53A and the second sleeve 53B, and a shaft hole portion 154 that is the origin of the shaft hole 54. The original member 150 further includes a first machined portion 160 and a second machined portion 170. Note that the original member 150 shown in FIGS. 6 and 7 is a common member with different viewing angles and has the same shape. The original member 150 is manufactured by casting.

[0066] The manufacturing method of the shift fork 50 (see FIG. 4C) of the present disclosure includes a step of manufacturing the original member 150 (hereinafter also referred to as the first step), and a step of processing the original member 150 to manufacture the first member 50A and the second member 50B (hereinafter also referred to as the second step).

[0067] [Regarding the first step] The original member 150 is manufactured using a simple mold in which the drawing direction is one direction. In the manufacturing method of the shift fork 50 of the present embodiment, the first step includes a step of manufacturing the original member 150 by casting.

[0068] [Regarding the second step] As shown in FIG. 6, the second step includes a step of manufacturing the first member 50A by performing first machining on the first machined portion 160 and the second machined portion 170.

[0069] The first machining includes machining for forming the first arm 51 from the arm portion 151, machining for forming the first sleeve 53A from the sleeve portion 153, and machining for forming the shaft hole 54 from the shaft hole portion 154. Specifically, the first machining forms the first arm 51, the first sleeve 53A, and the shaft hole 54 by machining (such as cutting, grinding, polishing, etc.).

[0070] The first machining includes machining for forming the first coupling portion 57 from the first workpiece portion 160. Specifically, the first machining includes machining for forming the first convex portion 57a, the first concave portion 57b, the first surface 57c, the second surface 57d, and the third surface 57e by machining (such as cutting, grinding, polishing, etc.).

[0071] Further, the first machining includes a process of forming the engaging portion 55 from the second workpiece portion 170. Specifically, the first machining includes machining for forming the groove portion 55a (engaging portion 55) in the second workpiece portion 170 by machining (such as cutting, grinding, polishing, etc.). Thereby, the engaging portion 55 is provided in the first member 50A. Note that the first machining may include surface treatments such as heat treatment and nitriding treatment for the first coupling portion 57 and the engaging portion 55.

[0072] Thus, in the shift fork 50 of the present embodiment, the engaging portion 55 is provided in either one of the first member 50A and the second member 50B (the first member 50A in the present embodiment). According to the shift fork 50 having such a configuration, in the shift fork 50 constituted by the first member 50A and the second member 50B, the engaging portion 55 can be easily provided.

[0073] As shown in FIG. 7, the second step includes a step of manufacturing the second member 50B by performing second machining on the first workpiece portion 160 and the second workpiece portion 170.

[0074] The second machining includes machining for forming the second arm 52 from the arm portion 151, machining for forming the second sleeve 53B from the sleeve portion 153, and machining for forming the shaft hole 54 from the shaft hole portion 154. Specifically, the second machining forms the second arm 52, the second sleeve 53B, and the shaft hole 54 by machining (such as cutting, grinding, polishing, etc.).

[0075] The second machining includes machining for forming the second joint portion 58 from the first workpiece portion 160. Specifically, the second machining includes machining for forming the second convex portion 58a, the second concave portion 58b, the fourth surface 58c, the fifth surface 58d, and the sixth surface 58e by machining (such as cutting, grinding, polishing, etc.). Note that the second machining may include surface treatments such as heat treatment and nitriding treatment for the second joint portion 58.

[0076] Also, the second machining includes machining for the second workpiece portion 170. Specifically, the second machining includes machining for removing at least a part of the second workpiece portion 170 by machining (such as cutting, grinding, polishing, etc.). The portion that was the second workpiece portion 170 in the original member 150 becomes a form that cannot be used as the joint portion 55 in the second member 50B after the second machining.

[0077] Furthermore, the second machining includes machining for the housing portion 59c of the second member 50B. Specifically, the second machining includes machining for the hole that becomes the housing portion 59c by machining (such as cutting, grinding, polishing, etc.). According to the manufacturing method of the shift fork 50 of the present disclosure, by machining a hole in the second member 50B, a detent mechanism 59 can be easily provided in the shift fork 50. Note that in the shift fork 50 of the present embodiment, the housing portion 59c is provided in the second member 50B, but the housing portion 59c may be provided in the first member 50A.

[0078] The manufacturing method of the shift fork 50 of the present embodiment can easily provide the engaging portion 55 by providing the engaging portion 55 machined from the second workpiece portion 170 in the first member 50A and removing at least a part of the second workpiece portion 170 in the second member 50B.

[0079] Conventionally, when manufacturing a shift fork having a pair of arms by casting, it is necessary to use a complicated mold with two or more drawing directions, which increases the manufacturing cost of the mold and also increases the time required for manufacturing. Such a shift fork has a high manufacturing cost due to the complicated configuration of the mold.

[0080] On the other hand, when manufacturing the original member 150 shown in FIGS. 6 and 7 by casting, a simple mold with the drawing direction being one direction can be used. The shift fork 50 of the present embodiment manufactures the first member 50A and the second member 50B from the original member 150 manufactured using a simple mold, and by combining these, the shift fork 50 having the first arm 51 and the second arm 52 can be manufactured. According to such a manufacturing method of the shift fork 50, by using a mold with a simple configuration, the manufacturing cost of the shift fork 50 can be suppressed.

[0081] [Regarding another embodiment of the shift fork] In the shift fork 50 illustrated in the above description, the shapes of the first coupling portion 57 and the second coupling portion 58 are different, and as a result, the shapes of the first member 50A and the second member 50B are different. However, the shift fork 50 of the present disclosure may be configured by coupling the first member 50A and the second member 50B having the same shape. In this case, the shapes of the first coupling portion 57 and the second coupling portion 58 are made the same shape, and the engaging portion 55 is configured by the first member 50A and the second member 50B. In this case, the first processing and the second processing become the same processing, and only one type of member obtained by bisecting the shift fork 50 in the axial direction from one type of original member 150 needs to be manufactured. In such a shift fork 50, the processing of the original member 150 is unified into one step, enabling the first member 50A and the second member 50B to be manufactured more efficiently, and also enabling a reduction in the number of parts. Therefore, when the shift fork 50 is configured by the first member 50A and the second member 50B having the same shape, it becomes possible to further suppress the manufacturing cost of the shift fork 50.

[0082] [Regarding the operation and effect of the present embodiment] (1) The transmission mechanism 10 of the above embodiment includes a countershaft 32 and a shift shaft 56 that are parallel to each other, a first coupling sleeve 41 and a second coupling sleeve 42 that are displaceable along the countershaft 32, a sleeve 53 that is displaceable along the shift shaft 56, a first arm 51 provided on the sleeve 53 and engaging with the first coupling sleeve 41, and a shift fork 50 having a second arm 52 provided on the sleeve 53 and engaging with the second coupling sleeve 42. The shift fork 50 is configured by coupling a first member 50A that constitutes one axial side and a second member 50B that constitutes the other axial side. The first member 50A includes a first sleeve 53A that constitutes one axial side of the sleeve 53 and a first arm 51 provided on the first sleeve 53A. The second member 50B includes a second sleeve 53B that constitutes the other axial side of the sleeve 53 and a second arm 52 provided on the second sleeve 53B.

[0083] The transmission mechanism 10 configured as described above can manufacture the shift fork 50 using the first member 50A and the second member 50B that can be manufactured using a simple mold with the extraction direction as one direction. Thereby, the manufacturing cost of the shift fork 50 having the pair of first arm 51 and second arm 52 can be suppressed.

[0084] (2) In the transmission mechanism 10 of the above embodiment, the first sleeve 53A has a first coupling portion 57 that couples the second member 50B, the second sleeve 53B has a second coupling portion 58 that couples the first member 50A, and the first coupling portion 57 and the second coupling portion 58 couple each other. According to the above configuration, the first member 50A and the second member 50B can be coupled without using a separate coupling member. Thereby, the manufacturing cost of the shift fork 50 configured by coupling the first member 50A and the second member 50B can be suppressed.

[0085] (3) In the transmission mechanism 10 of the above embodiment, the first coupling portion 57 has a first convex portion 57a that protrudes in the radial direction of the first sleeve 53A, and a first concave portion 57b that recesses in a direction opposite to the convex direction of the first convex portion 57a. The second coupling portion 58 has a second convex portion 58a that protrudes in the radial direction of the second sleeve 53B and fits into the first concave portion 57b, and a second concave portion 58b that recesses in a direction opposite to the convex direction of the second convex portion 58a and fits into the first convex portion 57a. According to the above configuration, the shift fork 50 composed of the first member 50A and the second member 50B can reliably transmit the forces acting on the one side and the other side in the axial direction to the first coupling sleeve 41 and the second coupling sleeve 42. Thereby, it becomes possible to reliably displace the first coupling sleeve 41 and the second coupling sleeve 42 to one side and the other side in the axial direction.

[0086] (4) The transmission mechanism 10 of the above embodiment further includes a shift mechanism 80 that displaces the shift fork 50 in the axial direction of the shift shaft 56. The shift fork 50 has an engaging portion 55 that engages with the shift mechanism 80, and the engaging portion 55 is provided on one of the first member 50A and the second member 50B (the first member 50A). According to the above configuration, in the shift fork 50 composed of the first member 50A and the second member 50B, the engaging portion 55 can be easily provided.

[0087] (5) The transmission mechanism 10 of the above embodiment further includes a detent mechanism 59 that holds the shift fork 50 at a predetermined position in the axial direction of the shift shaft 56. The detent mechanism 59 includes a ball 59a and an elastic member 59b, and either one of the first member 50A and the second member 50B (the second member 50B) is provided with a housing portion 59c that houses the ball 59a and the elastic member 59b. According to the above configuration, in the shift fork 50 composed of the first member 50A and the second member 50B, the detent mechanism 59 can be easily provided.

[0088] (6) The shift fork 50 of the above embodiment includes a sleeve 53 through which a shift shaft 56 is inserted, and a pair of first arms 51 and second arms 52 provided on one axial side and the other axial side of the sleeve 53. The shift fork 50 is configured by coupling a first member 50A that constitutes one axial side and a second member 50B that constitutes the other axial side. The first member 50A includes a first sleeve 53A that constitutes one axial side of the sleeve 53, and a first arm 51 provided on the first sleeve 53A. The second member 50B includes a second sleeve 53B that constitutes the other axial side of the sleeve 53, and a second arm 52 provided on the second sleeve 53B.

[0089] According to the above configuration, the shift fork 50 can be manufactured using the first member 50A and the second member 50B that can be manufactured using a simple mold with the extraction direction being one direction. Thereby, the manufacturing cost of the shift fork 50 having the pair of first arms 51 and second arms 52 can be suppressed.

[0090] (7) In the shift fork 50 of the above embodiment, the first sleeve 53A has a first coupling portion 57 for coupling the second member 50B, and the second sleeve 53B has a second coupling portion 58 for coupling the first member 50A. The first coupling portion 57 and the second coupling portion 58 are coupled to each other. According to the above configuration, the first member 50A and the second member 50B can be coupled without using a separate coupling member. Thereby, the manufacturing cost of the shift fork 50 configured by coupling the first member 50A and the second member 50B can be suppressed.

[0091] (8) In the shift fork 50 of the above embodiment, the first coupling portion 57 is provided at the end on the other axial side of the first sleeve 53A, and has a first convex portion 57a that protrudes in the radial direction of the first sleeve 53A, and a first concave portion 57b that is recessed in a direction opposite to the convex direction of the first convex portion 57a. The second coupling portion 58 is provided at the end on one axial side of the second sleeve 53B, and has a second convex portion 58a that protrudes in the radial direction of the second sleeve 53B and fits into the first concave portion 57b, and a second concave portion 58b that is recessed in a direction opposite to the convex direction of the second convex portion 58a and fits into the first convex portion 57a. According to the above configuration, the first member 50A and the second member 50B can be reliably coupled with a simple configuration.

[0092] (9) In the shift fork 50 of the above embodiment, the first coupling portion 57 has a first surface 57c that is the side surface on the other axial side of the first convex portion 57a, a second surface 57d that is the side surface on one axial side of the first convex portion 57a and is also the side surface on the other axial side of the first concave portion 57b, and a third surface 57e that is the side surface on one axial side of the first concave portion 57b. The second coupling portion 58 has a fourth surface 58c that is the side surface on one axial side of the second convex portion 58a, a fifth surface 58d that is the side surface on the other axial side of the second convex portion 58a and is also the side surface on one axial side of the second concave portion 58b, and a sixth surface 58e that is the side surface on the other axial side of the second concave portion 58b. The first surface 57c and the sixth surface 58e, the second surface 57d and the fifth surface 58d, and the third surface 57e and the fourth surface 58c are respectively opposed to each other. According to the above configuration, the shift fork 50 composed of the first member 50A and the second member 50B can reliably transmit the forces acting on one axial side and the other axial side.

[0093] (10) In the shift fork 50 of the above embodiment, the first member 50A and the second member 50B have the same shape. According to the above configuration, the number of parts of the shift fork 50 formed by coupling the first member 50A and the second member 50B can be reduced, and thereby the manufacturing cost of the shift fork 50 can be suppressed.

[0094] (11) The manufacturing method of the shift fork of the above embodiment is a manufacturing method of a shift fork 50 including a sleeve 53 through which a shift shaft 56 is inserted, and a pair of first arms 51 and second arms 52 provided on one axial side and the other axial side of the sleeve 53. The manufacturing method of the shift fork 50 of the above embodiment includes a first step of creating a common original member 150 that serves as the basis for a first member 50A constituting one axial side of the shift fork 50 and a second member 50B constituting the other axial side, and processing the original member 150 to form a first member 50A including a first sleeve 53A constituting one axial side of the sleeve 53 and a first arm 51 provided on the first sleeve 53A, and a second member 50B including a second sleeve 53B constituting the other axial side of the sleeve 53 and a second arm 52 provided on the second sleeve 53B.

[0095] According to the above configuration, the first member 50A and the second member 50B can be created from the original member 150 that can be manufactured using a simple mold with a single extraction direction, and the shift fork 50 can be manufactured using these. Thereby, the manufacturing cost of the shift fork 50 having the pair of first arms 51 and second arms 52 can be suppressed.

[0096] (12) In the manufacturing method of the shift fork 50 of the above embodiment, the first member 50A has a first coupling portion 57 for coupling the second member 50B, and the second member 50B has a second coupling portion 58 for coupling the first member 50A. The original member 150 has a first machined portion 160 to be machined into the first coupling portion 57 or the second coupling portion 58, and the second step includes a step of performing a first machining on the first machined portion 160 to create the first member 50A, and a step of performing a second machining on the first machined portion 160 to create the second member 50B. According to the above configuration, only one type of simple mold with the extraction direction being one direction is used to manufacture only one type of original member 150. The first member 50A can be manufactured by performing the first processing on the original member 150, and the second member 50B can be manufactured by performing the second processing. Thereby, the manufacturing cost of the shift fork 50 having the pair of first arm 51 and second arm 52 can be suppressed.

[0097] (13) In the manufacturing method of the shift fork 50 of the above embodiment, the original member 150 further has a second machined portion 170 that is machined on an engaging portion 55 that engages with a shift mechanism 80 that displaces the sleeve 53 in the axial direction. In the manufacturing method of the shift fork 50, the second processing includes processing for removing at least a part of the second machined portion 170. According to the above configuration, in the shift fork 50 manufactured from one type of original member 150, the engaging portion 55 can be easily provided.

[0098] (14) In the manufacturing method of the shift fork 50 of the above embodiment, the first processing and the second processing are the same processing, and the first member 50A and the second member 50B have the same shape. According to the above configuration, the number of parts of the shift fork 50 formed by combining the first member 50A and the second member 50B can be reduced, and thereby the manufacturing cost of the shift fork 50 can be suppressed.

[0099] (15) In the manufacturing method of the shift fork 50 of the above embodiment, the first step includes a step of creating the original member 150 by casting. According to the above configuration, the original member 150 is manufactured using a simple mold with the extraction direction being one direction. The first member 50A is manufactured by performing the first processing on the original member 150, and the second member 50B is manufactured by performing the second processing, thereby manufacturing the shift fork 50. Thereby, the manufacturing cost of the shift fork 50 having the pair of first arm 51 and second arm 52 can be suppressed.

[0100] The above embodiments are illustrative in all respects and not restrictive. The scope of the rights of the present invention is shown not by the above embodiments but by the scope of the claims, and includes all modifications within the scope equivalent to the configurations described in the claims.

Explanation of Signs

[0101] 10 Transmission mechanism 32 Countershaft (first shaft) 41 First coupling sleeve 42 Second coupling sleeve 50 Shift fork 50A First member 50B Second member 51 First arm (arm) 52 Second arm (arm) 53 Sleeve 55 Engaging portion 56 Shift shaft (second shaft) 57 First coupling portion 57a First convex portion 57b First concave portion 57c First surface 57d Second surface 57e Third surface 58 Second coupling portion 58a Second convex portion 58b Second concave portion 58c Fourth surface 58d Fifth surface 58e Sixth surface 59 Detent mechanism 59a Ball 59b Elastic member 59c Accommodating portion 80 Shift mechanism 150 Original member 160 First machined portion 170 Second machined portion

Claims

1. A first shaft and a second shaft parallel to each other, a first coupling sleeve and a second coupling sleeve displaceable along the first shaft, a sleeve displaceable along the second shaft, a first arm provided on the sleeve and engaging with the first coupling, and a shift fork having a second arm provided on the sleeve and engaging with the second coupling sleeve, A transmission mechanism of a working machine comprising: The shift fork is configured by connecting a first member constituting one axial side and a second member constituting the other axial side, The first member includes a first sleeve constituting one axial side of the sleeve and the first arm provided on the first sleeve, The second member includes a second sleeve constituting the other axial side of the sleeve and the second arm provided on the second sleeve, a transmission mechanism of a working machine.

2. The first sleeve has a first coupling portion for coupling the second member, The second sleeve has a second coupling portion for coupling the first member, The first coupling portion and the second coupling portion are coupled to each other, the transmission mechanism of the working machine according to claim 1.

3. The first coupling portion has a first convex portion convex in the radial direction of the first sleeve and a first concave portion recessed in a direction opposite to the convex direction of the first convex portion, The second coupling portion has a second convex portion convex in the radial direction of the second sleeve and fitting with the first concave portion, and a second concave portion recessed in a direction opposite to the convex direction of the second convex portion and fitting with the first convex portion, the transmission mechanism of the working machine according to claim 2.

4. Further comprising a shift mechanism for displacing the shift fork in the axial direction of the second shaft, The shift fork has an engaging portion for engaging with the shift mechanism, The engaging portion is provided on either one of the first member and the second member, the transmission mechanism of the working machine according to claim 1 or claim 2.

5. Further comprising a detent mechanism for holding the shift fork at a predetermined position in the axial direction of the second shaft, The detent mechanism includes a ball and an elastic member, Either one of the first member and the second member is provided with a housing portion for housing the ball and the elastic member, the transmission mechanism of the working machine according to claim 1 or claim 2.

6. A sleeve through which a shaft is inserted, A pair of arms provided on one axial side and the other axial side of the sleeve, A shift fork comprising: The shift fork is configured by coupling a first member that constitutes one axial side and a second member that constitutes the other axial side. The first member includes a first sleeve that constitutes one axial side of the sleeve, and the first arm provided on the first sleeve. The second member includes a second sleeve that constitutes the other axial side of the sleeve, and the second arm provided on the second sleeve, and is a shift fork.

7. The first sleeve has a first coupling portion that couples the second member. The second sleeve has a second coupling portion that couples the first member. The shift fork according to claim 6, wherein the first coupling portion and the second coupling portion couple each other.

8. The first coupling portion is provided at an end on the other axial side of the first sleeve, and has a first convex portion that protrudes in the radial direction of the first sleeve, and a first concave portion that recesses in a direction opposite to the convex direction of the first convex portion. The second coupling portion is provided at an end on one axial side of the second sleeve, and has a second convex portion that protrudes in the radial direction of the second sleeve and fits with the first concave portion, and a second concave portion that recesses in a direction opposite to the convex direction of the second convex portion and fits with the first convex portion. The shift fork according to claim 7.

9. The first coupling portion has a first surface that is a side surface on the other axial side of the first convex portion, a second surface that is a side surface on one axial side of the first convex portion and is also a side surface on the other axial side of the first concave portion, and a third surface that is a side surface on one axial side of the first concave portion. The second coupling portion has a fourth surface that is a side surface on one axial side of the second convex portion, a fifth surface that is a side surface on the other axial side of the second convex portion and is also a side surface on one axial side of the second concave portion, and a sixth surface that is a side surface on the other axial side of the second concave portion. The shift fork according to claim 8, wherein the first surface and the sixth surface, the second surface and the fifth surface, and the third surface and the fourth surface face each other.

10. The shift fork according to claim 6 or claim 7, wherein the first member and the second member have the same shape.

11. A sleeve through which a shaft is inserted, A pair of arms provided on one axial side and the other axial side of the sleeve, A method for manufacturing a shift fork including: A first step of creating a common original member that is the origin of a first member that constitutes one axial side of the shift fork and a second member that constitutes the other axial side. A second step of processing the original member to create the first member including the first sleeve that constitutes one axial side of the sleeve and the first arm provided on the first sleeve, and the second member including the second sleeve that constitutes the other axial side of the sleeve and the second arm provided on the second sleeve. A method for manufacturing a shift fork, including this step.

12. The first member has a first coupling portion for coupling the second member. The second member has a second coupling portion for coupling the first member. The original member has a first machined portion that is machined on the first coupling portion or the second coupling portion. The second step includes a step of performing a first machining on the first machined portion to create the first member, and a step of performing a second machining on the first machined portion to create the second member. The method for manufacturing a shift fork according to claim 11.

13. The original member further has a second machined portion that is machined on an engaging portion that engages with a shift mechanism for axially displacing the sleeve. Either one of the first machining and the second machining includes a machining for removing at least a part of the second machined portion. The method for manufacturing a shift fork according to claim 12.

14. The first machining and the second machining are the same machining. The first member and the second member have the same shape. The method for manufacturing a shift fork according to claim 12.

15. The first step includes a step of creating the original member by casting. The method for manufacturing a shift fork according to claim 11 or claim 12.

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