Shifting fork mechanism of electronic gear shifting multi-gear transmission

Abstract

A shifting fork mechanism of an electronic gear shifting multi-gear transmission comprises a shifting fork and is characterized in that the shifting fork is in sliding fit with a shifting fork supporting shaft through a shaft hole formed in the tail of the shifting fork, the shifting fork supporting shaft is a fixed shaft and is in sliding fit with a U-shaped support, the U-shaped support is in sliding fit with the shifting fork supporting shaft through shaft holes formed in two side arms, and the U-shaped support is in sliding fit with the shifting fork supporting shaft. The fork tail of the shifting fork is located in an opening of the U-shaped support and is in sliding fit with the shifting fork supporting shaft through a shaft hole, a guide pin is arranged on a connecting portion between two side arms of the U-shaped support, and the guide pin is in clearance fit in a cam groove formed in a gear shifting cam, so that the gear shifting cam drives the shifting fork to axially move along the shifting fork supporting shaft through the U-shaped support to achieve gear shifting. The gear shifting cam is fixed on a rotating shaft, a speed reduction driven gear is arranged on the rotating shaft, the speed reduction driven gear is meshed with an output gear of a gear shifting motor to transmit electric gear shifting power, and the gear shifting motor is connected with a gear switch through a gear controller.

Description

Technical Field

[0001] The invention relates to the field of vehicle transmissions, and in particular to a shift fork mechanism of an electronically shifted multi-speed transmission. Background Art

[0002] The transmission is a very important component in cars and motorcycles. The transmission is usually set with different gears to output different transmission ratios. It is mainly used for switching between high and low gears or forward and reverse gears. During the shifting process, the shift fork mechanism drives the shift mechanism to engage with the gear gear, driving the gear gear to rotate and realize the switching of different gears.

[0003] The existing transmission shift fork mechanism is divided into manual control or automatic control; the manually controlled shift fork mechanism is usually arranged on the shift fork supporting shaft, which is a rotating shaft or a sliding shaft. The shift fork supporting shaft is connected to a manual control mechanism such as a control cable, and the manual control mechanism is operated to make the shift fork supporting shaft rotate circumferentially and move axially, so that the shift fork mechanism drives the shift mechanism to engage with the gear gear to complete the gear switching; the automatically controlled shift fork mechanism is similar to the manually controlled shift fork mechanism, except that the manual control mechanism is replaced by an automatic drive mechanism such as a motor, a hydraulic cylinder, or a cylinder, and the automatic drive mechanism makes the shift fork supporting shaft rotate circumferentially and move axially, so that the shift fork mechanism drives the shift mechanism to engage with the gear gear to complete the gear switching.

[0004] For example, CN215596385U discloses a fork assembly for an electric vehicle transmission: Figure 6 As shown, the utility model includes a fork shaft and a fork body, a first limit seat is provided in the middle of the fork shaft, second limit seats are provided on both sides of the first limit seat, a fork body is provided between the first limit seat and the second limit seat, and a spring is provided between the fork body and the first limit seat or between the fork body and the second limit seat; the fork shaft described in the utility model is a sliding shaft, and the shift fork is driven axially by the fork shaft to engage the shift mechanism with the gear gear to complete the gear switching.

[0005] CN215596385U Example 1: "A spring 7 is provided between the first fork body, the second fork body and the second limit seat 5. Under the action of the spring 7, the sleeves 6 on the first fork body and the second fork body are tightly attached to the first limit seat 4. In the initial state, the two shift wheels 13 are combined with the second gear 11 to achieve the second gear output; when the fork shaft 1 moves toward the first gear 10, the first fork body is driven to move toward the first gear 10 through the first limit seat 4, and the shift wheel 13 is combined with the first gear 10, thereby achieving the first gear output; similarly, when the fork shaft 1 moves toward the third gear 12, the second fork body is driven to move toward the third gear 12 through the first limit seat 4, and the shift wheel 13 is combined with the third gear 12, thereby achieving the third gear output; when the fork shaft 1 drives the first fork body or the second fork body to separate from the second gear 11 through the first limit seat 4, and is not combined with the first gear 10 and the third gear 12, That is, a neutral gear is formed. " (See paragraphs 0019 and 0021 of CN215596385U); Example 2: "A spring 7 is provided between the fork body and the first limit seat 4. Under the action of the spring 7, the sleeve 6 and the second limit seat 5 are tightly attached together. When assembled, the first fork body and the second fork body are located between the two gears and are respectively forked on a shift wheel 13. In the initial state, the two shift wheels 13 are separated from the gears and are in a neutral state; when the fork body is ... in a neutral state. When the fork shaft 1 moves toward the first fork body, the first fork body drives the shift wheel 13 to contact the gear, and under the action of the spring 7, the shift wheel 13 is combined with the gear to achieve shifting; similarly, when the fork shaft 1 moves toward the second fork body, the second fork body drives the shift wheel 13 to contact the gear, and under the action of the spring 7, the shift wheel 13 is combined with the gear to achieve shifting. " (see paragraph 0023 of CN215596385U).

[0006] Although the shift fork assembly of CN215596385U can avoid gear collision during gear shifting, it has the following disadvantages: 1. As described in Example 1, the shaft sleeves 6 on the first fork body and the second fork body are both in close contact with the first limit seat 4; with this installation method, the transmission is in the second gear in the initial state. The initial state of a common transmission is neutral. If the initial state is the second gear, the transmission may be in the gear when the vehicle is ignited, or the user's learning cost is increased, and the production cost of the corresponding software and hardware development is increased.

[0007] 2. As described in Example 2, a spring 7 is provided between the fork body and the first limit seat 4. Under the action of the spring 7, the sleeve 6 and the second limit seat 5 are tightly attached together. Although this installation method can achieve the initial state of neutral, when the fork shaft 1 moves toward the second fork body 2, the second fork body 2, under the action of the spring 7, makes the shift wheel 13 mesh with the third gear 12. At this time, the first fork body 3 makes the shift wheel 13 mesh with the second gear 11, and the shifting described in Example 2 of the utility model cannot be achieved.

[0008] 3. The first fork body 3 and the second fork body 2 are only axially limited on the fork shaft 1. The gear shaft 9 is a rotating shaft. The shift wheel 13 will drive the first fork body 3 and the second fork body 2 to rotate circumferentially along the fork shaft 1. Relative rotation occurs between the first fork body 3, the second fork body 2, the fork shaft 1, the spring 7, and the limit seat. The friction generated affects the life of the fork assembly.

[0009] 4. If the fork shaft 1 realizes axial movement under the action of an automatic control mechanism such as a cylinder or a linear motor, the volume of the transmission will increase, especially the size of the transmission along the axial direction of the fork shaft 1 will increase. Summary of the invention

[0010] The purpose of the present invention is to provide a shift fork mechanism to solve the problems existing in the prior art. The shift fork mechanism is controlled by a shift motor to rotate a shift cam, and the U-shaped bracket moves axially along the shift fork support shaft through the rotation of the shift cam. The shift fork is arranged in the U-shaped bracket and is driven by the U-shaped bracket to move axially. The shift mechanism connected to the shift fork meshes with gears of different gears to complete the gear switching.

[0011] The technical solution of the present invention is achieved in this way: The fork tail of the shift fork is located in the opening of the U-shaped bracket and slides with the shift fork supporting shaft through the shaft holes provided on the two side arms of the U-shaped bracket. A guide pin is provided on the connecting part between the two side arms of the U-shaped bracket. The guide pin clearance fits in a cam groove provided on a shift cam, so that the shift cam drives the shift fork to move axially along the shift fork supporting shaft to realize gear shifting through the U-shaped bracket. The shift cam is fixed on a rotating shaft. A reduction driven gear is provided on the rotating shaft. The reduction driven gear is meshed with an output gear of a shift motor to transmit electric shifting power. The shift motor is connected to a gear switch through a gear controller.

[0012] Preferably, the fork support shaft is provided with an axially extending circumferential limit cutting plane, and the two side arms of the U-shaped bracket and the axial hole of the fork are matched with the cross-sectional shape of the fork support shaft, so that the U-shaped bracket and the circumferential limit of the fork can be axially movable and slidably fitted on the fork support shaft.

[0013] Preferably, an adjustment spring is provided between the side arm of the U-shaped bracket and the shift fork, and the adjustment spring is sleeved on the shift fork support shaft.

[0014] Preferably, a strip hole is provided on the connecting portion of the U-shaped bracket, the long axis of the strip hole is parallel to the fork support shaft, a radially extending positioning pin is provided at the fork tail of the fork, the positioning pin is inserted into the strip hole and slidingly cooperates to form an axially movable circumferential positioning, and an adjustment spring is provided on the shaft section of the fork support shaft between the side arm of the U-shaped bracket and the fork.

[0015] Preferably, a sliding baffle is provided between the adjusting spring and the shift fork, and the adjusting baffle is slidably matched with a guide slot and a shift fork supporting shaft provided on the U-shaped bracket.

[0016] Preferably, it further comprises a gear locking mechanism, which comprises a positioning structure arranged on the rotating shaft and an elastic locking device arranged on the housing, and the elastic locking device cooperates with the positioning structure to lock the gear.

[0017] Preferably, the positioning structure is a plurality of positioning grooves arranged circumferentially on the rotating shaft, and the elastic locking device is composed of a limiting steel ball, a compression spring, and a locking screw. The limiting steel ball and the compression spring are sequentially assembled in the holes on the shell wall, the limiting steel ball cooperates with the positioning groove for positioning, and the locking screw thread cooperates in the hole to resist the compression spring.

[0018] Preferably, the positioning structure is a positioning plate with a plurality of positioning grooves arranged on the circumference, the positioning plate is fixedly connected to the rotating shaft, the elastic locking device is composed of a limit pin, a compression spring, and a locking screw, the limit pin and the compression spring are sequentially assembled in the holes on the shell wall, the limit pin cooperates with the positioning groove on the positioning plate for positioning, and the locking screw thread cooperates in the hole to resist the compression spring.

[0019] Preferably, the axial direction of the shift motor is arranged parallel to the axial direction of the rotating shaft, and the output gear and the reduction driven gear are spur gears.

[0020] Preferably, the axial direction of the shift motor is arranged perpendicular to the axial direction of the rotating shaft, the output gear is a worm, and the driven gear is a worm wheel.

[0021] With the above scheme, the driver presses the gear button on the gear switch to output the gear electrical signal to the motor controller, and the gear controller controls the shift cam to rotate to a specific position. The cam groove extending circumferentially on the shift cam is clearance-matched with the guide pin provided at the top of the U-shaped bracket, so that the U-shaped bracket moves axially along the shift fork support shaft to a specific position. The shift cam may be provided with multiple cam grooves, and the shift cam drives multiple U-shaped brackets to move axially to achieve multi-gear shifting. The shift fork support shaft is a fixed axis, and the axial length along the shift fork support shaft is shortened compared to the sliding shaft type shift fork support shaft. The adjusting spring provided in the shift fork bracket positions the shift fork axially, so that the shift mechanism connected to the shift fork is flexibly combined with the gear gear, thereby avoiding direct collision and extending the service life of the entire transmission. In addition, the use of an automatic control mechanism to control the rotation of the shift cam can achieve automatic shifting, reducing the user's learning cost.

[0022] Therefore, the present invention realizes electric shifting by controlling the gear controller to rotate the shift cam to a specific position by pressing the gear switch, thereby reducing the learning cost and driving difficulty of the user; the shift fork support shaft is fixed, and compared with the sliding shaft, the size of the transmission along the axial direction of the shift fork support shaft is reduced; the shift fork is indirectly connected to the shift cam by a U-shaped bracket, so that the shift fork and other components are prevented from generating relative rotation and friction under the rotation of the shift mechanism, thereby increasing the service life of the shift fork mechanism; an adjusting spring is arranged in the shift fork bracket, and the adjusting spring adjusts the shift mechanism and the shift fork support shaft. The gear gears are flexibly combined to prevent collision caused by the gear driving gear and the gear driven gear aligning during gear shifting, thereby increasing the service life of the shift fork mechanism; a locking mechanism is provided to lock the gear to compensate for the insufficient locking force when only the shift motor is used to lock the gear; an adjusting baffle is provided between the adjusting spring and the shift fork to compensate for the small contact area when the adjusting spring and the shift fork are in direct contact, resulting in direct relative friction between the two components; the shift cam can be provided with multiple cam grooves to connect multiple sets of shift fork brackets and shift forks, control the movement of multiple shift mechanisms, and realize multi-gear electronic shifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is a schematic diagram of the assembly of the shift fork of the present invention; Figure 3 is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 4 is a schematic diagram of the structure of Embodiment 3 of the present invention; Figure 5 is a schematic structural diagram of Embodiment 5 of the present invention; Figure 6 It is a structural schematic diagram of the prior art. DETAILED DESCRIPTION

[0024] Example 1: See Figure 1 , Figure 3 A shift fork mechanism of an electronically shifted multi-speed transmission includes a shift fork 108, wherein the shift fork 108 is slidably fitted on a shift fork support shaft 107 through an axial hole provided at the fork tail, wherein the shift fork support shaft 107 is a fixed shaft, and a U-shaped bracket 106 is slidably fitted on the shift fork support shaft 107.

[0025] The U-shaped bracket (106) is slidably matched with the fork support shaft (107) through the shaft holes provided on the two side arms (127). An adjustment spring 130 is provided in the opening of the U-shaped bracket 106. The adjustment spring 130 is sleeved on the fork support shaft 107 and is located between the side arms of the U-shaped bracket 106 and the fork 108. There is one adjustment spring 130, which is provided on one side of the fork 108, or there are two adjustment springs 130, which are respectively provided on both sides of the fork. An adjustment baffle 112 is provided between the adjustment spring 130 and the fork 108 to increase the contact area between the adjustment spring 130 and the fork 108 and to prevent direct friction between the adjustment spring 130 and the fork 108. The adjustment baffle 112 is slidably matched with the guide groove 132 provided on the U-shaped bracket 106 and the fork support shaft 107.

[0026] A guide pin 115 is provided on the U-shaped bracket 106, and the guide pin 114 is clearance-fitted in a cam groove 116 provided on a shift cam 105. The cam groove 116 can be provided in a plurality, so that the shift cam 105 drives the shift fork 108 to move axially along the shift fork supporting shaft 107 through the U-shaped bracket 106 to achieve shifting. The shift cam 105 is fixed on a rotating shaft 104, and a reduction driven gear 103 is provided on the rotating shaft 104. The reduction driven gear 103 is meshed with an output gear 102 of a shift motor 101 to transmit electric shifting power. The axial direction of the shift motor 101 is arranged parallel to the axial direction of the rotating shaft 104, and the output gear 102 and the reduction driven gear 103 are spur gears.

[0027] The shift motor 101 is controlled to rotate by a gear controller 109, and the gear controller 109 is controlled by a gear switch 110. The gear switch 110 is provided with a gear button corresponding to the variable gear of the reducer. When the gear button is pressed, the gear controller 109 identifies the gear position of the gear switch 110 and controls the output gear 102 of the shift motor 101 to rotate. The gear switch 110 can be provided on an instrument console or a steering control device of a locomotive.

[0028] The gear positions are circumferentially distributed along the contour of the cam groove 116 set on the shift cam 105, and each cam groove 116 controls 1 to 2 gears respectively. The shift is completed when the shift cam 105 rotates to the corresponding gear position. The gear position is neutral. The shift cam 105 rotates in the same direction to complete the shifting of different gears.

[0029] Example 2: See Figure 3 On the basis of Example 1, it also includes a gear locking mechanism, which includes a positioning structure 120 arranged on the rotating shaft 104 and an elastic locking device 121 arranged on the shell, and the elastic locking device 121 cooperates with the positioning structure 120 to lock the gear; the positioning structure 120 is a plurality of positioning grooves 133 circumferentially arranged on the large diameter end of the rotating shaft 104; the elastic locking device 121 includes a limiting steel ball 122, a compression spring 123, and a locking screw 124, the limiting steel ball 122 cooperates with the positioning groove 133 for positioning, and the limiting steel ball 122 is connected to the locking screw 124 fixed to the reducer shell through the compression spring 123.

[0030] Example 3: See Figure 4 On the basis of Example 1, it also includes a gear locking mechanism, which includes a positioning structure 120 arranged on the rotating shaft 104 and an elastic locking device 121 arranged on the shell, and the elastic locking device 121 cooperates with the positioning structure 120 to lock the gear; the positioning structure 120 is a positioning plate 125 arranged on the rotating shaft 104, and a plurality of positioning grooves 134 are arranged on the outer circumference of the positioning plate 125; the elastic locking device 121 includes a limiting nail 126, a compression spring 123, and a locking screw 124, and the limiting nail 126 cooperates with the positioning groove 134 on the positioning plate 125 for positioning, and the limiting nail 126 is connected to the locking screw 124 fixed to the reducer shell through the compression spring 123.

[0031] Example 4: See Figure 2 A strip hole 117 is provided on the connecting portion 128 of the U-shaped bracket 106, and the long axis of the strip hole 117 is parallel to the fork supporting shaft 107. A radially extending positioning pin 114 is provided at the fork tail of the fork 108. The positioning pin 114 is inserted into the strip hole 117 and slides to form an axially movable circumferential positioning. An adjusting spring 130 is provided on the shaft section of the fork supporting shaft 107 between the side arm 127 of the U-shaped bracket 106 and the fork 108.

[0032] Example 5: See Figure 5 The fork support shaft 107 is provided with an axially extending cutting plane, and the axial holes of the two side arms 127 of the U-shaped bracket 106 are slidably matched with the fork support shaft 107 to form an axially movable circumferential positioning; the axial direction of the shift motor 101 is perpendicularly arranged to the axial direction of the rotating shaft 104, the output gear 102 is a worm, and the driven gear 103 is a worm wheel.

[0033] During operation, the shift motor is connected to the shift switch through the shift controller, identifies the gear set by the shift switch 110, controls the operation of the shift motor 101, and drives the reduction driven gear 103 set on the rotating shaft 104 to rotate through the output gear 102 of the shift motor 101, so that the shift cam 105 rotates to a specific position, and the guide pin 114 is loosely fitted in the cam groove 116 set on the shift cam 105. The shift cam 105 drives the shift fork 108 to move axially along the shift fork support shaft 107 through the U-shaped bracket 106 to achieve shifting. When there are multiple cam grooves 116, in conjunction with multiple shift fork brackets 106 and shift forks 108, multiple shift mechanisms are driven to move to achieve multi-gear shifting.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A shift fork mechanism of an electronically shifted multi-speed transmission, comprising a shift fork (108), characterized in that: The shift fork (108) is slidably engaged with a shift fork support shaft (107) through an axial hole provided at the fork tail; the shift fork support shaft (107) is a fixed shaft; the shift fork support shaft (107) is slidably engaged with a U-shaped bracket (106); the U-shaped bracket (106) is slidably engaged with the shift fork support shaft (107) through axial holes provided on two side arms (127); the fork tail of the shift fork (108) is located in an opening of the U-shaped bracket (106) and is slidably engaged with the shift fork support shaft (107) through the axial hole; a guide pin (115) is provided on the connecting portion (128) between the two side arms (127) of the U-shaped bracket (106); the guide pin (115) is provided on the connecting portion (128) between the two side arms (127) of the U-shaped bracket (106); The pin (114) is loosely fitted in a cam groove (116) provided on a shift cam (105), so that the shift cam (105) drives the shift fork (108) to move axially along the shift fork support shaft (107) through the U-shaped bracket (106) to achieve shifting. The shift cam (105) is fixed on a rotating shaft (104). A reduction driven gear (103) is provided on the rotating shaft (104). The reduction driven gear (103) is meshed with an output gear (102) of a shift motor (101) to transmit electric shifting power. The shift motor (101) is connected to a shift switch (110) via a shift controller (109).

2. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 1, characterized in that: The shift fork support shaft (107) is provided with an axially extending circumferential limit cutting plane, and the axial holes of the two side arms (127) of the U-shaped bracket (106) and the shift fork (108) are matched with the cross-sectional shape of the shift fork support shaft (107), so that the U-shaped bracket (106) and the shift fork (108) are circumferentially limited and axially movable and slidingly fitted on the shift fork support shaft (107).

3. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 1 or 2, characterized in that: An adjustment spring (130) is provided between the side arm (127) of the U-shaped bracket (106) and the shift fork (108), and the adjustment spring (130) is sleeved on the shift fork support shaft (107).

4. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 1, characterized in that: A strip hole (117) is provided on the connecting portion (128) of the U-shaped bracket (106), the long axis of the strip hole (117) being parallel to the shift fork support shaft (107), a radially extending positioning pin (114) is provided at the fork tail of the shift fork (108), the positioning pin (114) being inserted into the strip hole (117) to slide and fit to form axially movable circumferential positioning, and an adjustment spring (130) is provided on the shaft section of the shift fork support shaft (107) between the side arm (127) of the U-shaped bracket (106) and the shift fork (108).

5. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 3 or 4, characterized in that: A sliding baffle (112) is provided between the adjusting spring (130) and the shift fork (108), and the adjusting baffle (112) is slidably matched with a guide slot (132) provided on the U-shaped bracket (106) and a shift fork support shaft (107).

6. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 1, characterized in that: It also includes a gear locking mechanism, which includes a positioning structure (120) arranged on the rotating shaft (104) and an elastic locking device (121) arranged on the housing, and the elastic locking device (121) cooperates with the positioning structure (120) to lock the gear.

7. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 6, characterized in that: The positioning structure (120) is a plurality of positioning grooves (133) arranged along the circumference of the rotating shaft (104). The elastic locking device (121) is composed of a limiting steel ball (122), a compression spring (123), and a locking screw (124). The limiting steel ball (122) and the compression spring (123) are sequentially assembled in the hole on the shell wall. The limiting steel ball (122) cooperates with the positioning groove (133) for positioning. The locking screw (124) is threadedly engaged in the hole to resist the compression spring (123).

8. The shift fork mechanism of the electronically shifted multi-speed transmission as claimed in claim 6, characterized in that: The positioning structure (120) is a positioning plate (125) having a plurality of positioning grooves (134) on its circumference. The positioning plate (125) is fixedly connected to the rotating shaft (104). The elastic locking device (121) is composed of a limiting pin (126), a compression spring (123), and a locking screw (124). The limiting pin (126) and the compression spring (123) are sequentially assembled in holes on the shell wall. The limiting pin (126) cooperates with the positioning grooves (134) on the positioning plate (125) for positioning. The locking screw (124) is threadedly engaged in the hole to resist the compression spring (123).

9. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 1, characterized in that: The axial direction of the gear-shifting motor (101) is arranged parallel to the axial direction of the rotating shaft (104); the output gear (102) and the speed-reducing driven gear (103) are spur gears.

10. The shift fork mechanism of the electronically shifted multi-speed transmission according to claim 1, characterized in that: The axial direction of the gear-shifting motor (101) is perpendicularly staggered with the axial direction of the rotating shaft (104); the output gear (102) is a worm, and the driven gear (103) is a worm wheel.

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