JPH081360U - Transmission shift fork support and operation structure - Google Patents

Abstract

(57) [Summary] [Object] To provide a shift fork support and operation structure capable of supporting a shift fork in a stable state. A base end portion 6d (6d ') of a shift fork 6 (6') is laterally positioned in a bulging portion 3X of a transmission cover 3 beyond a side wall 1A of a transmission case 1 and the base end portion 6d. (6d ') is provided with a pair of upper and lower holes 6b and 6c, respectively, and the shift fork 6 (6') is provided with the holes 6b and 6b.
6c, the upper and lower shift rails 7a and 7b which are parallel to each other and are positioned in the bulging portion 3X of the shift cover 3 and slidably supported on the shift cover side are inserted through the shift rail. Either one of 7a and 7b and the shift fork 6 (6 ') are fixed, and the shift lever 4 that is oriented vertically in the upward insertion portions 8a and 9a of the adapters 8 and 9 provided on the shift rails 7a and 7b. A transmission shift fork support structure in which a lower end 4a is inserted and engaged.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 According to the present invention, the tip end of a horizontally arranged shift fork is fitted to a plurality of transmission gears provided on a transmission, and the base end of the shift fork is slidably linked to a gear shift operation of a vertically oriented gear shift lever. The present invention relates to a supporting and operating structure of a lateral shift fork which is fixed to a shift rail and is configured to bring the shift gears into and out of mesh with each other as the shift rail slides.

[0002]

[Prior art]

 The transmission gear provided in the transmission case engages a plurality of driven gears provided on the drive shaft with a plurality of drive gears provided on the counter shaft corresponding to the driven gears by operating the transmission lever to set the first speed. , 2nd speed ... It can be arbitrarily selected and switched. That is, the shift rail, which is parallel to the drive shaft and slidably provided on the shift cover, is slid by the operation of the shift lever, and the shift rail is fixed to the shift rail via the adapter as the shift rail slides. The shifted fork is moved. Then, the sleeve of the driven gear is fitted in the open portion of the shift fork, and the driven gear slides on the drive shaft by the movement of the shift fork to come into contact with and separate from the drive gear, thereby performing a gear shift operation.

[0003]

[Problems to be solved by the device]

 By the way, since the shift fork of the transmission has a structure in which one shift rail is fitted into a hole provided in the shift fork and is fixed at an appropriate position of the shift rail via a bracket, particularly in a lateral direction. When supporting the shift fork, the shift fork pivots downwards by using the shift rail as a fulcrum when the transmission is assembled, and it takes extra time to assemble a complicated transmission. The shift rail that supports the sideways shift fork has a structure that is positioned inside the transmission case.To move the shift rail by inserting the shift lever from the side into the side wall opening of the transmission case. Requires the lower part of the gear shift lever to be formed diagonally, which not only complicates the structure, but also places most of the shift fork in the mission case as it is. However, there was a drawback that the restrictions on the installation position became strict and the degree of freedom in design was hindered. In addition, it is necessary to increase the contact area between the shift fork and the sleeve of the transmission gear in order to stabilize the shift fork during use, which makes it impossible to effectively use the limited space inside the transmission case. Was occurring. In view of the above situation, the present invention can support the shift fork in a stable state, thereby reducing the number of assembling steps, and hindering the flexibility of the structure of the shift lever and the arrangement of the shaft in the transmission case. It is an object of the present invention to provide a shift fork support and operation structure for a transmission, which has a small number of shift forks and can be set small.

[0004]

[Means for Solving the Problems]

 In order to achieve the object, the present invention provides an opening 1a on one side surface of a side wall 1A of a transmission case 1, and an opening 6a at the tip of a shift fork 6 (6 ') inserted laterally from the opening 1a is used for the transmission. A swelling portion 3X having an opening 3W communicating with the opening 1a and bulging outward and a vertical hole 3Z having an upper opening 3Y in a state of facing the inside of the case and covering the opening 1a. The transmission cover 3 having the above-mentioned structure is detachably provided on the side wall 1A of the transmission case 1, and the base end of the shift fork 6 (6 ') is provided in the bulging portion 3X of the transmission case 1 beyond the side wall 1A of the transmission case 1. The portion 6d (6d ') is laterally positioned, and the base end portion 6d (6d') is provided with a pair of upper and lower holes 6b, 6c, respectively, so that the shift fork 6 (6 ') is formed by the above-mentioned operation. The upper and lower shift rails 7a and 7b, which are parallel to the holes 6b and 6c and are located inside the bulging portion 3X of the speed change cover 3, are slidably supported on the speed change cover 3 side. Then, either one of the shift rails 7a and 7b and the shift fork 6 (6 ') are fixed, and the adapters 8 and 9 provided on the shift rails 7a and 7b are made to face the hole bottom of the vertical hole 3Z. Inserted from the upper opening 3Y of the vertical hole 3Z into the upward insertion portions 8a, 9a provided on the adapters 8, 9 and rotatably supported by the support boss 5 that closes the upper portion of the vertical hole 3Z and is oriented in the vertical direction. The gist is that the lower end 4a of the speed change lever 4 is inserted and engaged.

[0005]

[Action]

 After inserting the two parallel vertical shift rails perpendicularly to the lateral shift forks into the holes provided at the base end of the shift forks, shift to one of the vertical shift rails, for example, the upper shift rail. Secure the fork. In this state, the upper and lower shift rails are slidably supported in the bulging part of the transmission cover, and the open part at the tip of the shift fork is inserted from the opening on one side wall of the transmission case, so that the transmission cover is attached to the transmission case. Installing. Then, when the upper shift rail slides in the shift cover in conjunction with the operation of the shift lever, the shift fork fixed to the upper shift rail is stable without rotating downward with the lower shift rail as a guide. When the shift levers are moved in this state and the vertical shift lever is operated, the shift gears fitted to the shift forks move so that the corresponding shift gears mesh with each other and the shift operation can be performed.

[0006]

【Example】

 An embodiment of the shift fork support and operation structure of the present invention will be described with reference to the drawings. In the drawings, first, the outline of the present invention will be explained. An opening 1a is provided on one side surface of a side wall 1A of a transmission case 1 in a tractor or the like, and an opening 3W communicating with the opening 1a with the opening 1a being covered. A transmission cover 3 having a bulging portion 3X which is provided with a bulge and a bulging portion 3X which is bulged outward and a vertical hole 3Z which is provided with an upper opening portion 3Y is detachably fixed to a side wall 1A of a transmission case 1 via a bolt 2. Further, a gearshift lever 4 (main variable speed lever in the illustrated example) which is oriented in the vertical direction is rotatably supported by a vertical boss 3Z of the gearshift cover 3 via a support boss 5, and is attached to the lower end of the gearshift lever 4. Is a state in which the shift forks 6, 6 ′ are vertically shifted with the open portions 6 a of the shift forks 6, 6 ′ inserted through the openings 1 a provided in the side wall 1 A of the transmission case 1 facing sideways. And a horizontal shift fork type main shift, which is provided via the adapters 8 and 9, respectively. The base ends 6d and 6d ′ of the shift forks 6 and 6 ′ are located inside the bulging portion 3X of the transmission cover 3 beyond the side wall 1 of the transmission case 1 and outside the opening 1a. The gear shift lever 4 is rotatably supported by a support boss 5 that inserts a part of the lower portion thereof into the vertical hole 3Z of the gear shift cover 3 and closes the upper portion of the vertical hole 3Z through a holding spring 10 and a joint 11 and has a lower end. A ball joint 4a that engages with the adapters 8 and 9 is formed. Further, the support boss 5 used here integrally comprises a support portion 5a for supporting the speed change lever 4 and a mounting bracket 5b for the cartridge type oil filter 12 adjacent to the speed change cover 3, and the number of components is reduced. It is configured to reduce the occupied space.

The shift forks 6, 6 ′ are provided with an open portion 6 a near the tip thereof and are fitted with a sleeve S of a driven gear (not shown) that slides on the drive shaft D, and from the opening 1 a of the transmission case 1. A pair of upper and lower holes 6a and 6c are formed in the base end portion 6d located on the outer side, and two vertical shift rails 7a, which are perpendicular to the shift forks 6 and 6 ', are formed in the holes 6b and 6c, respectively. 7b is inserted. As shown in FIG. 2, the upper and lower shift rails 7a and 7b have a shift fork 6'fixed to the upper shift rail 7a via a bracket 13a, and a shift fork 6 mounted to the lower shift rail 7b with the bracket 13b. Is fixed through. Each of the vertical shift rails 7a and 7b has adapters 8 and 9 fixed to one end, the other end slidably supported by the insertion holes 3a and 3b of the speed change cover 3, and the middle portion of the speed change cover 3a. Is supported by the sliding fixed portion 3c.

As described above, the shift forks 6, 6 ′ are provided with the holes 6 b, 6 c vertically through which the two shift rails 7 a, 7 b pass, and the shift forks 6, 6 ′ are provided on one side of the holes 3 a or 3 b. By fixing to 7a and 7b and preventing rotation (falling down of the shift fork) due to its own weight by the other hole (3b or 3a), the assembly to the transmission case 1 is facilitated and Sliding friction with the gear due to the weight of the shift forks 6, 6'can be prevented. Further, since the base ends 6d of the shift forks 6, 6'and the vertical shift rails 7a, 7b are located in the bulging portion 3X on the side of the transmission cover 3, the transmission lever 4 is parallel to the side wall 1A of the transmission case 1. Not only can it be constructed as a linear lever, but the open portion 6a except the base end portions 6d, 6d 'of the shift forks 6, 6'can only be exposed inside the transmission case 1. There is an advantage that the degree of freedom in the arrangement configuration of the drive shaft in the transmission case 1 is not impeded.

Further, a plurality of grooves 14a, 14b, 14c and 15a, 15b, 15c are provided at the portions of the vertical shift rails 7a, 7b corresponding to the sliding fixing portion 3c. When each of the grooves 14a, 14b, 14c and 15a, 15b, 15c slides one of the vertical shift rails 7a, 7b by the operation of the shift lever 4, the sliding is stopped at a proper sliding position. It is provided for alignment and for holding the position after sliding. For example, the groove 14a provided on the upper shift rail 7a is for first speed, the groove 14b is neutral, and the groove 14c is for third speed. The groove 15a provided on the lower shift rail 7b is set for the second speed, the groove 15b is set for the neutral, and the groove 15c is set for the backward. The positioning and holding of the groove 15a are set as shown in FIG. This is done by engaging the balls 17, 17 of the poppet springs 16, 16 provided on the No. 3 and the pin 18 prevents the vertical shift rails 7a, 7b from sliding simultaneously.

The adapters 8 and 9 have an adapter 8 fixed to the shaft end of the upper shift rail 7a and an adapter 9 fixed to the shaft end of the lower shift rail 7b, respectively, so that the ball joint 4a of the shift lever 4 is inserted upward. The insertion portions 8a and 9a are formed to have a size such that at least the ball joint 4a of the speed change lever 4 can be completely set therein, and face the bottom of the vertical hole 3Z of the speed change cover 3.

FIG. 5 shows a second embodiment of the present invention, in which the opening portion 26a of the shift fork 26 is made smaller than the opening portion 6a of the shift fork 6 of the above embodiment (the contact area with the sleeve is set to be small. Since the shift fork 26 is supported by the upper and lower two shift forks 7a and 7b, the fitting force with the sleeve is not impaired even if the opening portion 26a of the shift fork 26 is set small. Can be used.

FIG. 6 shows a third embodiment of the present invention, in which the shift forks 6, 6 ′ are used for the transmission of the four speed shift (1st to 3rd gears and reverse) in the above embodiment. On the other hand, a shift fork 36, 36 ... Is used for a transmission of 6 speeds (1st to 5th speed and reverse), and three parallel shift rails 37a, 37b, 37c are provided with an adapter 38a, respectively. 38b and 38c are provided to be operated by the operation lever 34.

In FIG. 7, the upper and lower two shift rails 47a and 47b are fixed to a shift cover (not shown), and the shift fork 46 itself supported by the two shift rails 47a and 47b is mounted. The shift fork 46 and the shift lever 44 are connected to each other via a boss 48, and a poppet spring 48a is internally provided in the boss 48 so that one shift rail (the upper shift rail in the example shown in the figure). 47a) is provided with a shift fork 46 slidably, and the poppet spring 48a is engaged with the grooves 54a, 54b, 54c provided in the shift rail 47a by the operation of the shift lever 44.

Next, the operation of the present invention will be described with reference to FIGS. 2 to 4. For example, when gear shifting to the first speed, as shown in FIG. 4, the ball joint 4a of the shifting lever 4 is operated to the (a) side. Then, the ball joint 4a of the shift lever 4 is inserted into the insertion portion 8a of the adapter 8 fixed to the upper shift rail 7a. Further, when the speed change lever 4 is operated forward, the upper shift rail 7a slides, and at the same time, the shift fork 6'moves while sliding on the lower shift rail 7b and is fitted into the shift fork 6 '. The sleeve S slides on the drive shaft D, the ball 17 of the poppet spring 16 engages with the stopper groove 14a of the upper shift rail 7a, and the gear shift is completed in the first speed state. In the case of performing gear shifting to the second speed, the third speed, and the reverse, the first speed gear is returned to the neutral position, and then the speed change lever 4 is operated to the respective shift positions by the action in accordance with the above. .

[0015]

[Effect of device]

 As described above, according to the present invention, an opening is provided on one side surface of the side wall of the transmission case, and the opening of the tip of the shift fork inserted laterally from the opening faces the inside of the transmission case to cover the opening. In this state, an opening communicating with the opening is provided, and a transmission cover having a bulging portion bulging outward and a vertical hole having an upper opening is detachably provided on the side wall of the transmission case. The shift fork is laterally positioned in the bulging portion of the transmission cover over the side wall of the transmission case, and the base end is provided with a pair of upper and lower holes, respectively. The shift rails are positioned parallel to each other in the direction orthogonal to the holes and in the bulging portion of the shift cover, and the upper and lower shift rails slidably supported on the shift cover side are inserted to allow the shifter to move. Fix one of the rails and the shift fork, make the adapter provided on the shift rail face the bottom of the vertical hole, and insert it into the upward insertion part of the adapter from the upper opening of the vertical hole. Since the lower end of the vertically oriented gear shift lever, which is rotatably supported by the support boss that closes the top of the vertical hole, is inserted and engaged, the lateral shift fork can be stably supported on the gear shift cover side. When mounting, it becomes easy to assemble the shift fork with a complicated transmission. It is possible to make the structure of the gear shift lever simple in the vertical direction, and it is possible to reduce the freedom of the arrangement of the shafts in the mission case. Since the shift fork can be supported in a stable state by preventing downward rotation, the sliding surface of the shift fork can be reduced and sliding friction with the gear due to the fork's own weight is reduced. be able to. The structure is simplified and extremely useful practical effects are achieved.

[0016]

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a main part of a shift fork support structure according to the present invention, which is partially cross-sectional.

FIG. 2 is a side view showing a schematic configuration of a main part of a cross section of FIG.

FIG. 3 is a cross-sectional view showing a stopper structure of an up-down shift rail.

FIG. 4 is an enlarged front view showing the relationship between the adapter and the shift lever.

FIG. 5 is a front view of a shift fork showing another embodiment.

FIG. 6 is a front view of a shift fork showing still another embodiment.

FIG. 7 is a side view of the shift fork in which the shift fork itself is slid.

[Explanation of symbols]

 1 Transmission Case 1a Opening 3 Shift Cover 3W Opening 3X Expansion 3Y Upper Opening 3Z Vertical Hole 6 Shift Fork 6'Shift Fork 6a Opening 6b Hole 6c Hole 6d Base End 6d 'Base End 7a Shift Rail 7b Shift rail

Claims (1)

[Scope of utility model registration request] 1. An opening 1a is provided on one side surface of a side wall 1A of a transmission case 1, and an opening 6a at the tip of a shift fork 6 (6 ') inserted laterally from the opening 1a is made to face the inside of the transmission case. The opening 1
A bulging part 3X and an upper open part 3Y which are provided with an opening 3W communicating with the opening 1a and bulged outward while covering a.
A transmission cover 3 having a vertical hole 3Z provided with is provided on the side wall 1A of the transmission case 1 in a detachable manner, and the shift fork 6 is provided in the bulging portion 3X of the transmission cover 3 beyond the side wall 1A of the transmission case 1. 6 ') has a base end portion 6d (6d') positioned laterally, and a pair of upper and lower holes 6b, 6c are formed in the base end portion 6d (6d ') to form the shift fork 6 (6'). The holes 6b, 6
The shift rails 7a and 7b are slidably supported on the shift cover 3 side by being positioned parallel to the direction c and in the bulging portion 3X of the shift cover 3 so as to penetrate therethrough. By fixing either one of the shift rails 7a and 7b and the shift fork 6 (6 '),
The adapters 8 and 9 provided on the adapter 7b are made to face the hole bottom of the vertical hole 3Z, and the upward insertion portions 8a provided on the adapters 8 and 9,
Insert the vertical hole 3Z into the vertical hole 3Z from the upper opening 3Y of the vertical hole 3Z.
A shift fork support structure for a transmission, characterized in that a lower end 4a of a gearshift lever 4 which is rotatably supported by a support boss 5 which closes the upper part of the gearshift lever 4 and which is directed in the vertical direction is inserted and engaged.