A transmission shift fork mechanism

Abstract

The present invention discloses a transmission shift fork mechanism, including a shift fork assembly and a synchronizer assembly. The shift fork assembly includes a shift fork shaft, a shift fork connecting sleeve and a shift fork. The shift fork of the shift fork assembly is fixedly connected to the shift fork shaft through the shift fork connecting sleeve. The end of the shift fork is provided with a web groove along the length direction of the shift fork. A boss-shaped single web protrudes from the middle of the outer ring side wall of the synchronizer sleeve of the synchronizer assembly; the single web of the synchronizer sleeve is inserted into the web groove of the shift fork. A drum-shaped friction surface is provided on the web groove, and the drum-shaped height is the maximum value of the swing of the synchronizer sleeve during operation. The single web on the synchronizer sleeve cooperates with the web groove on the shift fork, which reduces the axial space under a specific shaft system, avoids the functional problems of the transmission hitting teeth and disengaging due to the shift fork damage causing the synchronizer sleeve to shift in place, reduces the manual shaking of the whole vehicle, and improves the shifting quality of the transmission.

Description

Technical Field

[0001] The invention relates to the field of transmissions, and in particular to a transmission shift fork mechanism. Background Art

[0002] The prior art transmission shift fork mechanism Figures 1 to 3 As shown. The transmission shift fork mechanism includes: a shift fork assembly 1 and a synchronizer assembly 2. The shift fork assembly 1 is provided with a shift fork shaft 12, a shift fork connecting sleeve 13 and a shift fork 14. The shift fork assembly 1 is slidably connected to the shaft hole of the transmission case through the shift fork shaft upper end 122 and the shift fork shaft lower end 121 on the shift fork shaft 12. The shift fork 14 is fixedly connected to the shift fork shaft 12 through the shift fork connecting sleeve 13. The end of the shift fork 14 is provided with a plastic sleeve 0141. The outer ring of the synchronizer gear sleeve 21 of the synchronizer assembly 2 is circumferentially provided with a gear sleeve groove 0211. When shifting gears, the shift fork assembly 1 moves, driving the shift fork 14 to move, causing the plastic sleeve 0141 to contact the upper and lower surfaces of the sleeve groove 0211 on the synchronizer sleeve 21, pushing the synchronizer sleeve 21 to move and shift gears. Due to the high-speed rotation of the synchronizer sleeve 21, accompanied by the inevitable deflection of the synchronizer sleeve 21 around the center axis, the upper and lower surfaces of the sleeve groove 0211 will continuously knock and unbalance the upper and lower friction surfaces of the plastic sleeve 0141, eventually causing the plastic sleeve 0141 to crack, collapse, fall off, and excessive wear, thereby causing the synchronizer sleeve 21 to shift gears inadequately, resulting in functional problems such as gear knocking and gear disengagement of the transmission.

[0003] At the same time, since the gear sleeve groove 0211 on the synchronizer gear sleeve 21 has two upper and lower webs, the two webs interfere with the shaft system in a specific shaft system space, making it impossible to install. It can only be used by extending the axial space, which increases the overall weight of the transmission, that is, increases the manufacturing cost of the transmission and the fuel consumption of the whole vehicle. Summary of the invention

[0004] The purpose of the present invention is to provide a transmission shift fork mechanism to address the deficiencies in the prior art, which can improve the wear resistance and impact resistance of the shift fork, extend the service life of the shift fork, avoid functional problems such as tooth knocking and gear disengagement caused by shift fork wear, and at the same time reduce the transmission of vibration and improve the shifting quality of the transmission.

[0005] The present invention discloses a transmission shift fork mechanism, comprising a shift fork assembly and a synchronizer assembly, wherein the shift fork assembly comprises a shift fork shaft, a shift fork connecting sleeve and a shift fork, wherein the shift fork of the shift fork assembly is fixedly connected to the shift fork shaft through the shift fork connecting sleeve, and a web groove is formed at the end of the shift fork along the length direction of the shift fork;

[0006] A boss-shaped single web protrudes from the middle of the side wall of the outer ring of the synchronizer gear sleeve of the synchronizer assembly;

[0007] The single web of the synchronizer gear sleeve is clamped into the web groove notch of the shift fork.

[0008] Furthermore, the end of the web groove is a friction surface folded toward the single web side, the groove of the friction surface section is narrowed in a drum shape, and the drum height is the maximum value of the swing of the synchronizer gear sleeve during operation.

[0009] Furthermore, the shift fork assembly is used to be slidably connected to the shaft hole of the transmission case through the upper end of the fork shaft and the lower end of the fork shaft on the fork shaft.

[0010] Furthermore, the end of the fork is formed by stamping a plate.

[0011] The beneficial technical effects of the present invention are:

[0012] 1) When shifting gears, the shift fork assembly moves, driving the shift fork to move, so that the drum-shaped friction surface on the web groove contacts the upper and lower parts of the single web on the synchronizer sleeve, pushing the synchronizer sleeve to move and shift gears. Due to the high-speed rotation of the synchronizer sleeve, accompanied by the inevitable deflection of the synchronizer sleeve around the central axis, the upper and lower parts of the single web will continuously hit and unbalance the extrusion of the drum-shaped friction surface. Since the web groove is provided with a drum-shaped friction surface, and the drum-shaped height of the drum-shaped friction surface is the maximum value of the synchronizer sleeve when it is running, the synchronizer sleeve can swing around the drum-shaped friction surface when it is running, avoiding the sleeve swinging directly hitting the shift fork and reducing the transmission of vibration. At the same time, it solves the problems of cracking, crushing, falling off, and excessive wear of traditional plastic sleeves, avoids the functional problems of the transmission hitting and disengaging due to the failure of the synchronizer sleeve to shift due to the damage of the shift fork, and improves the shifting quality of the transmission.

[0013] 2) Since the gear sleeve has a single web, it can save axial space, reduce the weight of the transmission, and reduce fuel consumption. When forging or powder metallurgy is used to make the blank of the gear sleeve, it is easier to form than the traditional two-web structure, uses less blank material, and the forged product has a dense internal structure and good performance.

[0014] 3) Injection molding has low material utilization, pollutes the environment, and has low parts molding efficiency. The web groove fork structure with drum-shaped friction surface is formed by sheet metal stamping and local high-frequency heat treatment, which eliminates the injection molding process, has fast molding, high efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a transmission shift fork mechanism in the prior art;

[0016] Figure 2 It is a schematic diagram of the structure of a transmission shift fork assembly in the prior art;

[0017] Figure 3It is a schematic diagram of a transmission synchronizer assembly of the prior art;

[0018] Figure 4 It is a schematic diagram of the transmission shift fork mechanism of the present invention;

[0019] Figure 5 It is a schematic diagram of the shift fork assembly of the present invention;

[0020] Figure 6 It is a schematic diagram of the web groove of the present invention;

[0021] Figure 7 It is a schematic diagram of the synchronizer assembly of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] See also Figures 4 to 7 The present invention discloses a transmission shift fork mechanism, comprising a shift fork assembly 1 and a synchronizer assembly 2. The shift fork assembly 1 comprises a shift fork shaft 12, a shift fork connecting sleeve 13 and a shift fork 14. The shift fork 14 of the shift fork assembly 1 is fixedly connected to the shift fork shaft 12 through the shift fork connecting sleeve 13. The end of the shift fork 14 is provided with a web groove 141 along the length direction of the shift fork 14.

[0024] A boss-shaped single web 211 protrudes from the middle of the outer ring side wall of the synchronizer gear sleeve 21 of the synchronizer assembly 2 .

[0025] The end of the web groove 141 is a friction surface 1411 folded toward the single web 211 , the groove of the friction surface 1411 is narrowed in a drum shape, and the drum height 1412 is the maximum value of the swing of the synchronizer gear sleeve 21 during operation.

[0026] The single web of the synchronizer gear sleeve 21 is inserted into the notch of the web groove 141 of the shift fork 14 .

[0027] The shift fork assembly 1 is slidably connected to the shaft hole of the transmission case through the shift fork shaft upper end 15 and the shift fork shaft lower end 16 on the shift fork shaft 12 .

[0028] The end of the shift fork 14 is formed by stamping a plate.

[0029] During operation, when shifting gears in driving state, the shift fork assembly 1 moves, driving the shift fork 14 to move, so that the drum-shaped friction surface 1411 on the web groove 141 contacts the upper and lower surfaces of the single web 211 on the synchronizer gear sleeve 21, pushing the synchronizer gear sleeve 21 to move and shift gears.

[0030] Due to the high-speed rotation of the synchronizer sleeve 21, accompanied by the inevitable deflection of the synchronizer sleeve 21 around the central axis, the upper and lower surfaces of the single web 211 will continuously strike and unbalancedly squeeze the drum-shaped friction surface 1411. Since a drum-shaped friction surface 1411 is provided on the web groove 141, and the drum height 1412 of the drum-shaped friction surface 1411 is the maximum value of the swing of the synchronizer sleeve 21 during operation, the synchronizer sleeve 21 can swing around the drum-shaped friction surface 1411 when it is operating, thereby preventing the synchronizer sleeve 21 from swinging directly and hitting the shift fork 14, reducing the transmission of vibration, and solving the problems of cracking, crushing, falling off, and excessive wear of traditional plastic sleeves. It also avoids the functional problems of the transmission hitting teeth and shifting out caused by the synchronizer sleeve shifting stroke not being in place due to damage to the shift fork, thereby improving the shifting quality of the transmission.

[0031] In addition, since the synchronizer gear sleeve 21 has a single web 211, it can save axial space on a specific shaft system, reduce the weight of the transmission, and reduce fuel consumption. When the blank of the gear sleeve is forged or made by powder metallurgy, it is easier to form than the traditional two-web structure, the blank material is less, and the forged product has a denser internal structure and better performance.

[0032] The plastic sleeve injection molding on the traditional shift fork has low material utilization rate, pollutes the environment, and has low part molding efficiency. The web groove type shift fork structure with drum-shaped friction surface is formed by sheet metal stamping and local high-frequency heat treatment, which eliminates the injection molding process, has fast molding, high efficiency and low cost.

Claims

1. A transmission shift fork mechanism, comprising a shift fork assembly (1) and a synchronizer assembly (2), wherein the shift fork assembly (1) comprises a shift fork shaft (12), a shift fork connecting sleeve (13) and a shift fork (14), characterized in that: The shift fork (14) of the shift fork assembly (1) is fixedly connected to the shift fork shaft (12) via a shift fork connecting sleeve (13), and a web groove (141) is formed at the end of the shift fork (14) along the length direction of the shift fork (14); A boss-shaped single web (211) protrudes from the middle of the outer ring side wall of the synchronizer gear sleeve (21) of the synchronizer assembly (2); The single web of the synchronizer gear sleeve (21) is inserted into a notch of a web groove (141) of the shift fork (14); The end of the web groove (141) is a friction surface (1411) folded toward the side of the single web (211), the groove of the friction surface (1411) section is narrowed in a drum shape, and the drum height (1412) is the maximum value of the swing of the synchronizer gear sleeve (21) during operation.

2. A transmission shift fork mechanism according to claim 1, characterized in that: The shift fork assembly (1) is used to be slidably connected to the shaft hole of the transmission case through the shift fork shaft upper end (15) and the shift fork shaft lower end (16) on the shift fork shaft (12).

3. A transmission shift fork mechanism according to claim 2, characterized in that: The end of the shift fork (14) is formed by stamping a plate.

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