Shift fork assembly

Abstract

A shift fork assembly is provided, which includes a shift fork shaft, a shift fork and a sleeve, wherein the shift fork shaft and the shift fork are formed in one piece, the sleeve is sleeved on the end of the shift fork shaft so as to be connected to the shift fork shaft, and the shift fork assembly is configured to be supported via the sleeve. The shift fork assembly has an integrally formed shift fork shaft and a shift fork, can bear a large shift force, and has a simple assembly method in which the sleeve is sleeved on the shift fork shaft.

Description

Technical Field

[0001] The invention relates to the technical field of vehicle parts, and in particular to a shift fork assembly. Background Art

[0002] like Figure 3 As shown, the existing shift fork assembly includes a shift fork shaft 1 and a shift fork 3 . The shift fork shaft 1 is made entirely of steel. The shift fork shaft 1 and the shift fork 3 are mounted together via a pin 5 .

[0003] The shift fork 3 has a fork mounting hole, the fork shaft 1 has a fork shaft mounting hole, and the pin 5 is inserted into the fork mounting hole and the fork shaft mounting hole, so that the fork shaft 1 and the shift fork 3 are relatively fixed in the axial direction and the circumferential direction of the fork shaft 1.

[0004] Such a shift fork assembly has the following disadvantages:

[0005] First, the shift fork shaft 1 is made of all steel, which is relatively expensive. In addition, the all-steel shift fork shaft 1 has a large mass, resulting in a large shift inertia and a low shift efficiency.

[0006] Second, the all-steel shift fork shaft 1 must usually be a round shaft, so it has poor adaptability in space.

[0007] Third, there is generally a gap between the fork shaft 1 and the shift fork 3, and the stability of the shift fork assembly is poor.

[0008] Fourth, the shifting force is transmitted through the pin 5, and the reliability of the shift fork assembly is poor.

[0009] Fifth, during the assembly of the shift fork assembly, it is necessary to ensure that the fork shaft mounting hole and the fork mounting hole are aligned, which places high demands on the assembly tooling, as well as the machining accuracy of the fork shaft mounting hole and the fork mounting hole. Summary of the invention

[0010] The present invention is made in view of the above-mentioned state of the prior art. The object of the present invention is to provide a shift fork assembly which is easy to assemble and has a large bearing capacity and can stably and reliably transmit the shift force.

[0011] The present disclosure provides a shift fork assembly, which includes a shift fork shaft, a shift fork and a shaft sleeve. The shift fork shaft and the shift fork are formed integrally, the shaft sleeve is sleeved on an end of the shift fork shaft to be connected to the shift fork shaft, and the shift fork assembly is configured to be supported via the shaft sleeve.

[0012] In at least one embodiment, at least a partial section of the sleeve is interference fit with the fork shaft.

[0013] In at least one embodiment, the shaft sleeve has an assembly section that is interference fitted with the fork shaft, and portions of the shaft sleeve on both axial sides of the assembly section are clearance fitted with the fork shaft.

[0014] In at least one embodiment, the shift fork assembly further includes a support bearing, wherein the support bearing is supported by a portion of the sleeve that is interference-fitted with the shift fork shaft.

[0015] In at least one embodiment, the sleeve includes a first section and a second section, the second section is closer to the axial end surface of the fork shaft than the first section, the first section and the second section are cylindrical, and the inner diameter of the first section is larger than the inner diameter of the second section.

[0016] In at least one embodiment, the end of the fork shaft has an inner section and an outer section, the outer diameter of the inner section is larger than the outer diameter of the outer section, and when the sleeve is assembled with the fork shaft, the first section is assembled correspondingly with a part of the inner section, the part of the second section close to the first section is interference fitted with the other part of the inner section, and the other part of the second section is assembled correspondingly with the outer section.

[0017] In at least one embodiment, the sleeve comprises:

[0018] A sleeve body, the sleeve body extending along the axial direction of the fork shaft and being connected to the fork shaft in a torsionally fixed manner;

[0019] an inner flange, the inner flange extending radially inwardly of the sleeve at one end of the sleeve body, the inner flange being capable of abutting against an end surface of the fork shaft in the axial direction; and

[0020] An outer flange extends radially outward from the other end of the sleeve body.

[0021] In at least one embodiment, the sleeve is interference fitted with the fork shaft, the sleeve includes a first section and a second section, the second section is closer to the axial end face of the fork shaft than the first section, and the interference between the first section and the fork shaft is smaller than the interference between the second section and the fork shaft.

[0022] In at least one embodiment, a pressure relief groove is provided at the end of the fork shaft, and the pressure relief groove is located on the outer wall of the fork shaft and is recessed toward the radial inner side of the fork shaft.

[0023] In at least one embodiment, the end of the fork shaft has a plurality of the pressure relief grooves.

[0024] In at least one embodiment, the shift fork shaft includes a middle portion directly connected to the shift fork and two end portions located on both axial sides of the middle portion, and one sleeve is interference-fitted on each of the two end portions.

[0025] In at least one embodiment, the fork shaft is made of aluminum.

[0026] In at least one embodiment, the sleeve is made of steel.

[0027] The shift fork assembly provided by the present disclosure has at least the following beneficial effects:

[0028] The shift fork assembly has an integrally formed shift fork shaft and a shift fork, thereby having a large bearing capacity, being able to stably and reliably transmit a large shift force, and having a simple assembly method of a shaft sleeve and a shift fork shaft set. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1a It is a schematic three-dimensional structural diagram of a first embodiment of a shift fork assembly provided by the present disclosure.

[0030] Figure 1b for Figure 1a A schematic diagram of the overall three-dimensional structure formed by the shift fork and the fork shaft of the shift fork assembly.

[0031] Figure 1c for Figure 1a An axial cross-section of the shaft sleeve of the shift fork assembly in FIG.

[0032] Figure 2a It is a schematic three-dimensional structural diagram of a second embodiment of the shift fork assembly provided by the present disclosure.

[0033] Figure 2b for Figure 2a The exploded view of the shift fork assembly in FIG. 1 shows the installation correspondence between the bushing and the fork shaft.

[0034] Figure 2c for Figure 2a Axial cutaway view of the shift fork assembly in FIG.

[0035] Figure 3 The present invention is a schematic diagram of the three-dimensional structure of an existing shift fork assembly.

[0036] Description of reference numerals:

[0037] 1 shift fork shaft, 3 shift fork, 5 pin;

[0038] 10 fork shaft, 11 end, 110 pressure relief groove, 111 inner section, 112 outer section, 113 blind hole, 12 middle section, 20 sleeve, 21 sleeve body, 211 first section, 212 second section, 2120 assembly section, 210 transition step, 22 outer flange, 23 inner flange, 30 shift fork. DETAILED DESCRIPTION

[0039] The exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not intended to exhaust all possible modes of the present invention, nor to limit the scope of the present invention.

[0040] like Figures 1a to 2c As shown, the present disclosure provides a shift fork assembly, which includes a shift fork 30, a fork shaft 10 and a sleeve 20. The shift fork 30 and the fork shaft 10 are formed in one piece, and the sleeve 20 is sleeved on the two ends 11 of the fork shaft 10 on the outside of the fork shaft 10, so that the sleeve 20 is connected to the fork shaft 10, for example, it can be connected in a torsion-proof manner.

[0041] It should be understood that the extension direction of the fork shaft 10 is the same as the extension direction of the sleeve 20, that is, the axial direction of the fork shaft 10 is the same as the axial direction of the sleeve 20, and the "axial direction" mentioned below refers to the axial direction of the fork shaft 10 and the axial direction of the sleeve 20.

[0042] The shift fork 30 and the fork shaft 10 are integrally formed, and specifically, can be made of aluminum material through a die-casting process. The aluminum material can include a cast aluminum material with a certain strength, such as an aluminum alloy.

[0043] The aluminum shift fork 30 and the fork shaft 10 have a small mass, which is conducive to reducing the mass of the shift fork assembly. In addition, the cross section of the aluminum fork shaft 10 can be formed into various shapes not limited to a circle, which improves the adaptability of the shift fork assembly in space.

[0044] It should be understood that the shift fork 30 and the fork shaft 10 may also be made of other light metals.

[0045] The fork shaft 10 includes a middle portion 12 and two end portions 11 arranged along the axial direction. The shift fork 30 is formed integrally with the middle portion 12 of the fork shaft 10 , and the sleeve 20 is connected to the end portions 11 of the fork shaft 10 .

[0046] The fork shaft 10 may be a substantially round shaft, the outer contour of the cross section of the two ends 11 of the fork shaft 10 may be circular, and the sleeve 20 may be substantially cylindrical, so that the fork shaft 10 and the sleeve 20 can be conveniently and quickly aligned along the axial direction, thereby improving assembly efficiency.

[0047] Of course, the end portion 11 of the fork shaft 10 and the shaft sleeve 20 may be in other shapes, as long as the shapes of the end portion 11 of the fork shaft 10 and the shaft sleeve 20 match so as to be assembled together in the axial direction.

[0048] In order to prevent casting defects and reduce material weight, the cross-sectional shape of the middle section of the fork shaft 10 may be irregular.

[0049] The shaft sleeve 20 and the end 11 of the fork shaft 10 can be connected together in a rotationally fixed manner by interference fitting, thereby achieving a stable and firm connection between the fork shaft 10 and the shaft sleeve 20 .

[0050] like Figure 2c As shown, the end of the fork shaft 10 may also have a blind hole 113, and the blind hole 113 is recessed from the end surface along the axial direction of the fork shaft 10 toward the inside of the fork shaft 10, and the fork shaft 10 may form a blind hole 113 at each of the two ends. When the shift fork assembly is actuated, the oil applies oil pressure to the shift fork assembly in the axial direction, and the oil acts on the end surface of the fork shaft 10 and the bottom of the blind hole 113 (located inside the fork shaft 10) in the axial direction, thereby actuating the shift fork assembly in the axial direction. By providing the blind hole 113, the aluminum fork shaft 10 can be further reduced in weight by reducing the material.

[0051] Figure 1c An axial section through a bushing 20 in a first embodiment is shown. Figure 2b The mounting correspondence between the shaft sleeve 20 and the fork shaft 10 in the second embodiment is shown.

[0052] In two specific embodiments of the present disclosure, the sleeve 20 is cylindrical, and includes a sleeve body 21, an inner flange 23, and an outer flange 22. The inner flange 23 can extend radially inwardly of the sleeve 20 at one end of the sleeve body 21 (close to the end surface of the fork shaft 10), and the outer flange 22 can extend radially outwardly of the sleeve 20 at the other end of the sleeve body 21 (close to the shift fork 30). The inner flange and the outer flange can both be formed in a ring shape in planes parallel to each other.

[0053] When the sleeve 20 and the fork shaft 10 are assembled, the inner flange 23 can abut against the end face of the fork shaft 10 in the axial direction. Specifically, the inner flange 23 is in surface contact with the end face of the fork shaft 10 in the axial direction. The inner flange 23 serves to limit the sleeve 20 and the fork shaft 10 in the axial direction.

[0054] The shaft sleeve 20 may be made of steel, so that the shaft sleeve 20 has good wear resistance and high bearing capacity.

[0055] The sleeve 20 can be processed by heat treatment process, so that the sleeve 20 has higher strength. In the process of heat treatment of the sleeve 20, the inner flange 23 and the outer flange 22 play a role in preventing the two ends of the sleeve 20 from being deformed.

[0056] The sleeve body 21 may have a first section 211 and a second section 212 arranged axially. The second section 212 is closer to the inner flange 23 than the first section 211, that is, when the sleeve 20 and the fork shaft 10 are assembled, the second section 212 is closer to the end surface of the fork shaft 10.

[0057] The cross section of the sleeve body 21 may be circular, and a transition step 210 may be provided between the first section 211 and the second section 212 so that the inner diameter of the first section 211 is larger than the inner diameter of the second section 212. The first section 211 is assembled to the fork shaft 10 before the second section 212, which makes the initial assembly easier.

[0058] The outer wall of the sleeve body 21 may have a consistent radial dimension along the axial direction, that is, the outer diameters of the first section 211 and the second section 212 are equal, and the wall thickness of the first section 211 may be smaller than the wall thickness of the second section 212 .

[0059] Figure 1b The fork shaft 10 is shown in a first embodiment.

[0060] In this embodiment, there is a first interference between the first section 211 and the fork shaft 10 , and there is a second interference between the second section 212 and the fork shaft 10 . The first interference may be smaller than the second interference.

[0061] The first section 211 is assembled to the fork shaft 10 before the second section 212, and the interference between the first section 211 and the fork shaft 10 is smaller, which makes the initial assembly easier. The second section 212 is assembled to the fork shaft 10 after the first section 211, and the interference between the second section 212 and the fork shaft 10 is larger, so that the sleeve 20 is more firmly connected to the fork shaft 10 through the second section 212.

[0062] like Figure 1b As shown, the fork shaft 10 may have a decompression groove 110 at both ends 11, and the decompression groove 110 may be formed around the outer wall of the fork shaft 10. The decompression groove 110 is located on the outer wall of the fork shaft 10 and is recessed radially (perpendicular to the axial direction of the fork shaft 10) toward the inner side of the fork shaft 10. The number of the decompression grooves 110 may be multiple, and the multiple decompression grooves 110 may be arranged along the axial direction.

[0063] Since the inner wall of the sleeve 20 does not contact the fork shaft 10 at the notch of the decompression groove 110, the presence of the decompression groove 110 reduces the contact area between the fork shaft 10 and the sleeve 20, avoiding an excessively large press-fit area between the sleeve 20 and the fork shaft 10, thereby avoiding damage to the sleeve 20 and the fork shaft 10.

[0064] Figure 2bThe fork shaft 10 and the sleeve 20 in the second embodiment are shown.

[0065] like Figure 2b As shown, the sleeve 20 may have an assembly section 2120 that is interference-fitted with the fork shaft 10. For example, the assembly section 2120 may be located in the axial middle portion of the sleeve 20, and the portions of the sleeve 20 on both axial sides of the assembly section 2120 may be clearance-fitted with the end 11 of the fork shaft 10. This further ensures that the sleeve 20 and the fork shaft 10 are interference-fitted only at a local section (assembly section 2120) of the sleeve 20.

[0066] Of course, in other embodiments, the portions of the sleeve 20 on both axial sides of the assembly section 2120 can be transitionally matched with the end 11 of the fork shaft 10, or assembled with an interference fit smaller than the interference fit between the assembly section 2120 and the end 11.

[0067] The end 11 of the fork shaft 10 may have an inner section 111 and an outer section 112 with different outer diameters, and the outer section 112 is closer to the axial end surface of the fork shaft 10 than the inner section 111. The outer diameter of the inner section 111 may be larger than the outer diameter of the outer section 112. The length of the outer section 112 is smaller than the length of the second section 212, and the length of the inner section 111 is larger than the length of the first section 211.

[0068] The assembly section 2120 can be located at a position of the second section 212 close to the first section 211 , the inner section 111 is assembled with the first section 211 of the sleeve 20 and the assembly section 2120 , and the outer section 112 is assembled with the other parts of the second section 212 of the sleeve 20 except the assembly section 2120 .

[0069] Such a structure can easily form an assembly pattern of clearance fit (transition fit, or smaller interference fit), interference fit, and clearance fit (transition fit or smaller interference fit) between the fork shaft 10 and the sleeve 20 from outside to inside.

[0070] Referring to the second embodiment, taking the position where the assembly section 2120 is located in the second section 212 close to the first section 211 as an example, the assembly process of the fork shaft 10 and the sleeve 20 is described:

[0071] The other end of the sleeve 20 (the end where the outer flange 22 is located) is aligned with the fork shaft 10 in the axial direction and approaches the fork shaft 10 in the axial direction from the outside of the fork shaft 10;

[0072] After the outer flange 22 passes over the end surface of the fork shaft 10 , a first gap is formed between the inner wall of the first section 211 and the end 11 of the fork shaft 10 ;

[0073] When the entire first section 211 is just mounted on the fork shaft 10 , the transition step 210 is aligned with the end surface of the fork shaft 10 in the axial direction;

[0074] When the entire second section 212 is sleeved on the fork shaft 10, a second gap is formed between the second section 212 except the assembly section 2120 and the fork shaft 10, the inner flange 23 abuts against the end surface of the fork shaft 10 in the axial direction, and the sleeve 20 and the fork shaft 10 are assembled.

[0075] In other embodiments, the assembly segment 2120 may also be located at other parts of the second segment 212 , such as a portion of the second segment 212 between the assembly segment 2120 and the first segment 211 .

[0076] In other embodiments, a plurality of assembly segments 2120 may be included, and the plurality of assembly segments 2120 may be spaced apart in the axial direction.

[0077] The shift fork assembly may further include a support bearing. When the shift fork is mounted on the external structure, the support bearing may be mounted on the sleeve 20, so that the sleeve 20 is directly supported by the support bearing, and the fork shaft 10 and the shift fork 30 are indirectly supported.

[0078] The support bearing can be supported on the portion of the sleeve 20 that is interference fitted with the fork shaft 10, such as the above-mentioned assembly section 2120. Since the assembly section 2120 is interference fitted with the fork shaft 10, the support bearing can obtain better supporting rigidity.

[0079] Support bearings include bushings, rolling bearings, etc.

[0080] In other embodiments, the support bearing may also be supported at a position of the sleeve 20 that is not interference fitted with the fork shaft 10 , such as a position that is clearance fitted with the fork shaft 10 , such as an end of the sleeve 20 .

[0081] In the first embodiment or the second embodiment, the sleeve 20 can be partially interference fitted with the end 11 of the fork shaft 10, so that the sleeve 20 and the end 11 of the fork shaft 10 have a smaller interference contact surface and the press-fitting force therebetween is smaller.

[0082] When the shift fork assembly is installed on the external structure, a sealing ring for sealing the installation space of the shift fork assembly may also be installed on the sleeve 20. The steel sleeve 20 and the sealing ring are combined to obtain a good sealing effect.

[0083] The above describes two specific embodiments provided by the present disclosure. In other specific embodiments, the following variations may also be provided:

[0084] (1) The inner flange 23 and the outer flange 22 may not be formed into a ring shape in a plane perpendicular to the axial direction. For example, the inner flange 23 and the outer flange 22 extend in a plane inclined relative to the axial direction, that is, the inner flange 23 and the outer flange 22 are formed into a trumpet shape, or the inner flange 23 and the outer flange 22 extend in a wave shape in a direction perpendicular to the axial direction, etc., so that a part of the inner flange 23 can be against the end face of the fork shaft 10.

[0085] (2) It is also possible to make different sections of the sleeve 20 along the axial direction have different assembly states with the fork shaft 10 by other means. For example, the sleeve body 21 has a uniform wall thickness, and different sections have different outer diameters and different inner diameters, that is, the sleeve body 21 has a step on the outer wall; or the sleeve body 21 has a uniform inner diameter, and different sections of the fork shaft 10 have different outer diameters.

[0086] (3) The length of the assembly section 2120 can be set according to the magnitude of the shifting force. For example, when the shift fork assembly is used in a situation where the shifting force is large, the length of the assembly section 2120 is set to be large so that the shift fork assembly can be assembled more firmly. On the contrary, when the shift fork assembly is used in a situation where the shifting force is small, the length of the assembly section 2120 is set to be small so that the shift fork assembly can be assembled more easily.

[0087] It should be understood that the above embodiments are only exemplary and are not intended to limit the present invention. Those skilled in the art may make various modifications and changes to the above embodiments under the guidance of the present invention without departing from the scope of the present invention.

Claims

1. A shift fork assembly, characterized in that: The shift fork assembly comprises a shift fork shaft (10), a shift fork (30) and a shaft sleeve (20); the shift fork shaft (10) and the shift fork (30) are formed integrally; the shaft sleeve (20) is sleeved on an end portion (11) of the shift fork shaft (10) so as to be connected to the shift fork shaft (10); the shift fork assembly is configured to be supported via the shaft sleeve (20); at least a partial section of the shaft sleeve (20) is interference-fitted with the shift fork shaft (10) so as to be connected together in a torsionally rigid manner; the shaft sleeve (20) comprises a first section (211) and a second section (212); the second section (212) is closer to an axial end face of the shift fork shaft (10) than the first section (211); the first section (211) and the second section (212) are The second section (212) is cylindrical, the inner diameter of the first section (211) is larger than the inner diameter of the second section (212), the end (11) of the fork shaft (10) comprises an inner section (111) and an outer section (112), the outer diameter of the inner section (111) is larger than the outer diameter of the outer section (112), when the bushing (20) is assembled with the fork shaft (10), the first section (211) is assembled with a part of the inner section (111), a part of the second section (212) close to the first section (211) is interference-fitted with other parts of the inner section (111), and other parts of the second section (212) are assembled with the outer section (112).

2. The shift fork assembly according to claim 1, characterized in that: The shaft sleeve (20) has an assembly section (2120) which is interference fitted with the shift fork shaft (10), and portions of the shaft sleeve (20) on both axial sides of the assembly section (2120) are clearance fitted with the shift fork shaft (10).

3. The shift fork assembly according to claim 1, characterized in that: The shift fork assembly further comprises a support bearing, the support bearing being supported on a portion of the shaft sleeve (20) that is interference-fitted with the shift fork shaft (10).

4. The shift fork assembly according to any one of claims 1 to 3, characterized in that: The shaft sleeve (20) comprises: A shaft sleeve body (21), the shaft sleeve body (21) extending along the axial direction of the shift fork shaft (10) and being connected to the shift fork shaft (10) in a rotationally fixed manner; an inner flange (23), the inner flange (23) extending radially inwardly of the shaft sleeve (20) at one end of the shaft sleeve body (21), the inner flange (23) being capable of abutting against an end surface of the fork shaft (10) in the axial direction; and An outer flange (22), the outer flange (22) extending radially outward from the other end of the shaft sleeve body (21) toward the shaft sleeve (20).

5. The shift fork assembly according to any one of claims 1 to 3, characterized in that: The end (11) of the fork shaft (10) is provided with a decompression groove (110), and the decompression groove (110) is located on the outer wall of the fork shaft (10) and is recessed toward the radial inner side of the fork shaft (10).

6. The shift fork assembly according to claim 5, characterized in that: The end (11) of the fork shaft (10) has a plurality of pressure relief grooves (110).

7. The shift fork assembly according to any one of claims 1 to 3, characterized in that: The shift fork shaft (10) comprises a middle portion (12) directly connected to the shift fork (30) and two end portions (11) located on both axial sides of the middle portion (12), and a shaft sleeve (20) is interference-fitted on each of the two end portions (11).

8. The shift fork assembly according to any one of claims 1 to 3, characterized in that: The shift fork shaft (10) is made of aluminum.

9. The shift fork assembly according to any one of claims 1 to 3, characterized in that: The shaft sleeve (20) is made of steel.

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