Hydraulic shifting device, gearbox and vehicle

Abstract

This application provides a hydraulic shifting device, a transmission, and a vehicle. The hydraulic shifting device includes: a shift fork assembly, including a connected fork shaft and a shift fork; a hydraulic cylinder, including a cylinder body, a first piston, and a second piston, the first piston and the second piston being respectively disposed at the axial ends of the fork shaft, the first piston, the fork shaft, and the second piston being movably disposed inside the cylinder body along the axial direction of the fork shaft, and the interior of the cylinder body being divided into a first oil chamber, a fork shaft chamber, and a second oil chamber; and a gear locking mechanism, installed in the cylinder body, the gear locking mechanism being configured to be able to move radially along the fork shaft, thereby locking or releasing the fork shaft. With this configuration, when the fork shaft is locked by the gear locking mechanism, the fork shaft cannot move along its own axial direction, realizing the function of limiting gear position and preventing disengagement. Compared with using a reverse bevel gear meshing method between the synchronizer and the engagement gear, the tooth flank clearance between the synchronizer and the engagement gear is reduced, which helps to reduce knocking noise when in gear.

Description

Technical Field

[0001] This application relates to the field of transmission technology, and in particular to a hydraulic shifting device, transmission, and vehicle. Background Technology

[0002] In automobiles, the transmission typically contains a shift mechanism that allows for the engagement and disengagement of different gears. Currently, most mainstream transmissions use hydraulically driven shift mechanisms, which utilize hydraulic pressure to drive the shift fork shafts to perform the gear-shifting operation.

[0003] Currently, in order to prevent the transmission from automatically disengaging from a certain gear to neutral while the vehicle is in motion, resulting in a power interruption, the synchronizer and engagement gear are usually made to mesh with inverted bevel teeth. However, this structure results in a large backlash between the synchronizer and engagement gear, which can easily generate knocking noise when the transmission is in gear and the gearbox is dragging back and forth, affecting the vehicle's NVH performance. Summary of the Invention

[0004] In view of this, this application provides a hydraulic shifting device, a transmission, and a vehicle that can reduce noise while preventing gear slippage.

[0005] Specifically, the following technical solutions are included:

[0006] In a first aspect, embodiments of this application provide a hydraulic shifting device, comprising:

[0007] The shift fork assembly includes a connected fork shaft and a shift fork;

[0008] A hydraulic cylinder includes a cylinder body, a first piston, and a second piston. The first piston and the second piston are respectively disposed at the two ends of the axial direction of the fork shaft. The first piston, the fork shaft, and the second piston are movably disposed inside the cylinder body along the axial direction of the fork shaft, and the inside of the cylinder body is divided into a first oil chamber, a fork shaft chamber, and a second oil chamber.

[0009] A gear locking mechanism is installed in the cylinder body and is configured to move radially along the fork shaft to lock or release the fork shaft.

[0010] In an optional embodiment, the cylinder block has an oil passage and a socket, the socket being connected to the fork shaft cavity, and the gear locking mechanism includes a first elastic element and a locking pin connected together. The locking pin is movably inserted into the socket and divides the oil passage into a first segment and a second segment, the first segment being connected to the first oil cavity, and the second segment being connected to the second oil cavity.

[0011] In an optional embodiment, the hydraulic shifting device further includes a first limiting block, the first limiting block including a block body and a boss protruding from the block body, the block body being disposed on the fork shaft, the end of the boss being provided with a first groove, the boss having a first limiting surface and a second limiting surface that are opposite to each other, the first limiting surface and the second limiting surface being distributed at intervals along the axial direction of the fork shaft;

[0012] The hydraulic shifting device has a first gear, a second gear, and a third gear. In the first gear, the locking pin abuts against the first limiting surface; in the second gear, the locking pin is inserted into the first groove; and in the third gear, the locking pin abuts against the second limiting surface.

[0013] In an optional embodiment, the hydraulic shifting device further includes a first check valve and a second check valve;

[0014] The first check valve is disposed between the first oil chamber and the first segment, and the conduction direction of the first check valve is from the first oil chamber to the first segment;

[0015] The second check valve is disposed between the second oil chamber and the second section, and the conduction direction of the second check valve is from the second oil chamber to the second section.

[0016] In an alternative embodiment, the shape of the first groove is adapted to the shape of the end of the locking pin.

[0017] In an optional embodiment, the hydraulic shifting device further includes a limiting mechanism and a second limiting block;

[0018] The limiting mechanism is radially and retractably mounted on the cylinder body along the fork shaft;

[0019] The second limiting block is disposed on the fork shaft. The second limiting block and the first limiting block are spaced apart along the axial direction of the fork shaft, and the second limiting block and the first limiting block are offset in the circumferential direction of the fork shaft. The second limiting block has a second groove. In the second stop position, the limiting mechanism extends into the second groove.

[0020] In an optional embodiment, the limiting mechanism includes a second elastic member and a positioning member connected together, wherein, in the second stop position, at least a portion of the positioning member is accommodated in the second groove;

[0021] The second limiting block includes a first surface and a second surface, which are spaced apart along the axial direction of the fork shaft. The sidewalls of the second groove smoothly transition with the first surface and the second surface, respectively. The second groove is an arc-shaped groove.

[0022] In an optional embodiment, the extended surfaces of the first surface and the second surface form an angle.

[0023] In an optional embodiment, the positioning element is a rotatable rolling element capable of rolling relative to the second limiting block.

[0024] Secondly, embodiments of this application provide a gearbox, including the hydraulic shifting device provided in any of the embodiments of the first aspect.

[0025] Thirdly, embodiments of this application provide a vehicle including the gearbox provided in the second aspect embodiment.

[0026] The beneficial effects of the technical solution provided in this application embodiment include at least the following: by setting the gear locking mechanism to be able to move radially along the fork shaft, the gear locking mechanism can change its state by moving, thereby locking or releasing the fork shaft; when the fork shaft is locked by the gear locking mechanism, the fork shaft cannot move along its own axial direction, realizing the function of limiting gear position and preventing disengagement. Compared with the method of using reverse conical teeth to mesh the synchronizer and the engagement teeth, the tooth flank clearance between the synchronizer and the engagement teeth is reduced, which helps to reduce the knocking noise when in gear; when the fork shaft is released by the gear locking mechanism, the fork shaft can move along its own axial direction to shift gears, ensuring that shifting is carried out normally. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A perspective view of the hydraulic shifting device provided in the embodiments of this application;

[0029] Figure 2 An exploded view of the hydraulic shifting device provided in the embodiments of this application;

[0030] Figure 3 This is a schematic diagram of the cylinder block provided in an embodiment of this application;

[0031] Figure 4 This is a top view of the hydraulic shifting device provided in the embodiments of this application;

[0032] Figure 5 This is a right view of the hydraulic shifting device provided in an embodiment of this application;

[0033] Figure 6 for Figure 5 A cross-sectional view along the AA direction;

[0034] Figure 7 for Figure 5 Cross-sectional view along the BB direction;

[0035] Figure 8 This is a schematic diagram of the structure of the first limiting block and the second limiting block provided in the embodiments of this application.

[0036] The reference numerals in the figure are respectively:

[0037] 1-Shift fork assembly; 11-Fork shaft; 12-Shift fork;

[0038] 2-Hydraulic cylinder; 21-Cylinder body; 21a-First oil chamber; 21b-Second oil chamber; 21c-Fork shaft chamber; 22-First piston; 221-Seal; 23-Second piston; 24a-First section; 24b-Second section; 25-Insertion hole;

[0039] 3- Gear locking mechanism; 31- First elastic element; 32- Locking pin;

[0040] 4-First limiting block; 41-Block body; 42-Boss; 421-First groove; 422-First limiting surface; 423-Second limiting surface;

[0041] 51 - First check valve; 52 - Second check valve;

[0042] 6-Limiting mechanism; 61-Second elastic element; 62-Positioning element;

[0043] 7-Second limiting block; 71-Second groove; 72-First surface; 73-Second surface;

[0044] 8-Position sensor; 9-Magnetic block; 10-Limiting insert.

[0045] The accompanying drawings have illustrated specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to specific embodiments. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] In the embodiments of this application, directional terms such as "upper," "lower," and "side" are generally used in the following ways: Figure 1 The relative positions shown are based on the given information, and these directional terms are used only to more clearly describe the relationships between structures, not to describe absolute positions. Positions may change when the product is placed in different orientations; for example, "up" and "down" may be interchanged.

[0048] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by those skilled in the art. Some technical terms appearing in the embodiments of this application are described below.

[0049] To make the technical solutions and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0050] like Figures 1 to 8 As shown in the figure, this application embodiment provides a hydraulic shifting device applied to a gearbox.

[0051] like Figure 1 As shown, the hydraulic shifting device includes a shift fork assembly 1, a hydraulic cylinder 2, and a gear locking mechanism 3.

[0052] The shift fork assembly 1 includes a fork shaft 11 and a shift fork 12 connected together. The fork shaft 11 is generally cylindrical in shape. One end of the shift fork 12 is connected to the fork shaft 11, and the other end is used to push the synchronizer sleeve in the gearbox to move axially along the fork shaft 11 so that it engages with the engagement teeth to realize the gear shifting operation of the gearbox.

[0053] like Figure 6 and Figure 7 As shown, the hydraulic cylinder 2 includes a cylinder body 21, a first piston 22 and a second piston 23. The first piston 22 and the second piston 23 are respectively disposed at the two ends of the axial direction of the fork shaft 11. The first piston 22, the fork shaft 11 and the second piston 23 are movably disposed inside the cylinder body 21 along the axial direction of the fork shaft 11, and the inside of the cylinder body 21 is divided into a first oil chamber 21a, a fork shaft chamber 21c and a second oil chamber 21b.

[0054] For example, both the first piston 22 and the second piston 23 are provided with sealing elements 221 such as sealing rings to ensure the sealing between the first oil chamber 21a, the second oil chamber 21b, and the fork shaft chamber 21c. Optionally, such as Figure 4 As shown, sealing elements 221, such as sealing rings, are provided at both ends of the cylinder body 21.

[0055] like Figure 2 As shown, the fork shaft 11 extends in the horizontal direction, and the axial direction of the fork shaft 11 is parallel to the horizontal direction. The first piston 22 and the second piston 23 are fixed at the left and right ends of the fork shaft 11. The first piston 22 and the second piston 23 can move synchronously with the fork shaft 11 in the horizontal direction.

[0056] The fork shaft cavity 21c is used to accommodate the fork shaft 11, and the first oil cavity 21a and the second oil cavity 21b are both used to introduce fluids such as hydraulic oil. The first oil cavity 21a and the second oil cavity 21b are both provided with oil inlets. By introducing hydraulic oil into the first oil cavity 21a or the second oil cavity 21b, the hydraulic pressure can be used to push the first piston 22, the second piston 23 and the fork shaft 11 to move along the axial direction of the fork shaft 11, thereby driving the shift fork 12 to shift gears.

[0057] The gear locking mechanism 3 is installed in the cylinder 21 and is configured to move radially along the fork shaft 11, thereby locking or releasing the fork shaft 11.

[0058] Specifically, the gear locking mechanism 3 has a locked state and a released state, and the gear locking mechanism 3 can switch between the locked state and the released state.

[0059] In the locked state, the gear locking mechanism 3 is connected to the fork shaft 11. Under the restriction of the gear locking mechanism 3, the fork shaft 11 cannot move along its own axis, thus realizing gear limiting and preventing disengagement.

[0060] In the released state, the gear locking mechanism 3 is disengaged from the fork shaft 11, allowing the fork shaft 11 to move along its own axis, thereby performing a gear shifting operation.

[0061] For example, the gear locking mechanism 3 switches between the locking state and the releasing state through electrical signals, hydraulic pressure, etc.

[0062] For example, such as Figure 1 As shown, the hydraulic shifting device also includes a position sensor 8 and a magnetic block 9. The position sensor 8 is mounted on the cylinder body 21, and the magnetic block 9 is mounted on the fork shaft 11. The position sensor 8 detects gear changes by detecting the position of the magnetic block 9 and provides a shift position signal.

[0063] The hydraulic shifting device provided in this application embodiment allows the shift locking mechanism 3 to move radially along the fork shaft 11, thereby changing its state and locking or releasing the fork shaft 11. When the fork shaft 11 is locked by the shift locking mechanism 3, it cannot move axially, achieving in-gear limiting and anti-disengagement functions. Compared to using a reverse bevel gear meshing method between the synchronizer and the engagement gear, this reduces the tooth flank clearance between the synchronizer and the engagement gear, which helps reduce knocking noise when in gear. When the fork shaft 11 is released by the shift locking mechanism 3, it can move axially to shift gears, ensuring normal shifting.

[0064] In a further embodiment, the cylinder block 21 has oil passages and insertion holes 25. For example... Figure 3 As shown, the insertion hole 25 is connected to the fork shaft cavity 21c. Figure 6As shown, the gear locking mechanism 3 includes a first elastic member 31 and a locking pin 32 connected together. The locking pin 32 is movably inserted into the insertion hole 25 and divides the oil passage into a first section 24a and a second section 24b. The first section 24a is connected to the first oil chamber 21a, and the second section 24b is connected to the second oil chamber 21b.

[0065] In this embodiment, the gear locking mechanism 3 moves radially along the fork shaft 11 under the action of the first elastic member 31 and hydraulic oil, thereby switching between the locked state and the released state.

[0066] For example, the first elastic element 31 is a compression spring, which extends radially along the fork shaft 11 and is capable of elastic deformation along the radial direction of the fork shaft 11.

[0067] The insertion hole 25 extends radially along the fork shaft 11, and the locking pin 32 is sealed to the insertion hole 25. The locking pin 32 moves radially along the fork shaft 11 under the constraint of the insertion hole 25.

[0068] Specifically, under the elastic force of the first elastic element 31, the locking pin 32 passes through the insertion hole 25 and engages with the fork shaft 11, thereby locking the fork shaft 11.

[0069] When hydraulic oil is introduced into the first oil chamber 21a, the hydraulic oil flows to the first section 24a and pushes the locking pin 32, overcoming the elastic force of the first elastic element 31, causing the locking pin 32 to move away from the fork shaft 11, thereby disengaging the locking pin 32 from the fork shaft 11 and ensuring that the gear shifting operation is carried out normally.

[0070] When hydraulic oil is introduced into the second oil chamber 21b, the hydraulic oil flows to the second section 24b and pushes the locking pin 32, overcoming the elastic force of the first elastic element 31, causing the locking pin 32 to move away from the fork shaft 11, thereby disengaging the locking pin 32 from the fork shaft 11.

[0071] After the gear shift is completed, the hydraulic oil is depressurized, and the locking pin 32 moves towards the side closer to the fork shaft 11 under the elastic force of the first elastic element 31, and enters the locking state again to realize the anti-disengagement function.

[0072] In a further embodiment, the hydraulic shifting device also includes a first limiting block 4, such as Figure 8 As shown, the first limiting block 4 includes a block body 41 and a boss 42 protruding from the block body 41. The block body 41 is disposed on the fork shaft 11. The end of the boss 42 is provided with a first groove 421. The boss 42 has a first limiting surface 422 and a second limiting surface 423 that are opposite to each other. The first limiting surface 422 and the second limiting surface 423 are distributed at intervals along the axial direction of the fork shaft 11.

[0073] The hydraulic shifting device has a first gear, a second gear, and a third gear. In the first gear, the locking pin 32 abuts against the first limiting surface 422; in the second gear, the locking pin 32 is inserted into the first groove 421; and in the third gear, the locking pin 32 abuts against the second limiting surface 423.

[0074] In this embodiment, the locking pin 32 and the first limiting block 4 cooperate to achieve the gear locking mechanism 3 and the fork shaft 11 in the locked state, so that the gear locking mechanism 3 can lock the fork shaft 11 in the first gear, the second gear and the third gear.

[0075] like Figure 8 As shown, the first limiting surface 422 and the second limiting surface 423 are located on both sides of the boss 42 on the axial direction of the fork shaft 11. When the locking pin 32 abuts against the first limiting surface 422 or the locking pin 32 abuts against the second limiting surface 423, the first limiting block 4 and the fork shaft 11 are difficult to move along the axial direction of the fork shaft 11, and the hydraulic shifting device cannot disengage to other gears, thus realizing the in-gear locking function.

[0076] The first groove 421 is provided at the end of the boss 42 away from the block 41. The first groove 421 is used to accommodate the end of the locking pin 32, so that the locking pin 32 is inserted into the first groove 421 and it is difficult to move relative to the first limiting block 4. The hydraulic shifting device cannot disengage to other gears, thereby realizing the in-gear locking function.

[0077] When the locking pin 32 is no longer in contact with the first limiting block 4, the locking pin 32 switches to the released state, allowing the fork shaft 11 to move along its own axis and switch to other positions.

[0078] Optionally, in the first gear, the surface of the second piston 23 facing away from the fork shaft 11 abuts against the inner wall of the second oil chamber 21b, which serves as a gear shifting limit. Compared with the gear-limiting structure used in the prior art, this reduces the gear shifting impact noise. Furthermore, under the constraint of the locking pin 32 and the inner wall of the second oil chamber 21b, the in-gear locking effect of the fork shaft 11 is further enhanced. In the second gear, the surface of the first piston 22 facing away from the fork shaft 11 abuts against the inner wall of the first oil chamber 21a, which serves as a gear shifting limit. Furthermore, under the constraint of the locking pin 32 and the inner wall of the first oil chamber 21a, the in-gear locking effect of the fork shaft 11 is further enhanced.

[0079] Optionally, such as Figure 6 or Figure 7As shown, both the inner wall of the second oil chamber 21b and the inner wall of the first oil chamber 21a are provided with limiting inserts 10. In the first gear position, the surface of the second piston 23 away from the fork shaft 11 abuts against the limiting insert 10 in the second oil chamber 21b; in the second gear position, the surface of the first piston 22 away from the fork shaft 11 abuts against the limiting insert 10 in the first oil chamber 21a. The limiting insert 10 plays a role in limiting gear shifting.

[0080] For example, the limiting insert 10 is made of materials such as plastic and rubber, which has less hardness than the metal cylinder 21. This reduces the impact force of the first piston 22 and the second piston 23 on the cylinder 21, providing a certain buffering effect and also helping to reduce noise.

[0081] In a further embodiment, such as Figure 6 As shown, the hydraulic shifting device also includes a first check valve 51 and a second check valve 52.

[0082] The first check valve 51 is disposed between the first oil chamber 21a and the first section 24a, and the conduction direction of the first check valve 51 is from the first oil chamber 21a to the first section 24a.

[0083] The second check valve 52 is disposed between the second oil chamber 21b and the second section 24b, and the conduction direction of the second check valve 52 is from the second oil chamber 21b to the second section 24b.

[0084] In this embodiment, by setting a first check valve 51 and a second check valve 52, hydraulic oil backflow is prevented, thereby improving hydraulic pressure transmission efficiency.

[0085] In one embodiment, such as Figure 6 As shown, the shape of the first groove 421 is adapted to the shape of the end of the locking pin 32.

[0086] By setting the shape of the first groove 421 to match the shape of the end of the locking pin 32, the locking pin 32 and the first groove 421 are fully engaged in the second position, preventing the locking pin 32 from coming out of the first groove 421 along the axial direction of the fork shaft 11, thus improving the anti-disengagement effect. At the same time, the contact area between the end of the locking pin 32 and the first groove 421 is increased, dispersing the impact force generated when the locking pin 32 is inserted into the first groove 421.

[0087] For example, such as Figure 6 As shown, the end of the locking pin 32 that is away from the first elastic member 31 is arc-shaped, and the first groove 421 is an arc-shaped groove.

[0088] In one embodiment, the hydraulic shifting device further includes a limiting mechanism 6 and a second limiting block 7.

[0089] The limiting mechanism 6 is radially and retractably mounted on the cylinder body 21 along the fork shaft 11.

[0090] like Figure 4 , Figure 7 and Figure 8 As shown, the second limiting block 7 is disposed on the fork shaft 11. The second limiting block 7 and the first limiting block 4 are spaced apart along the axial direction of the fork shaft 11, and the second limiting block 7 and the first limiting block 4 are offset in the circumferential direction of the fork shaft 11. The second limiting block 7 has a second groove 71. In the second stop position, the limiting mechanism 6 extends into the second groove 71.

[0091] like Figure 4 As shown, the second limiting block 7 and the first limiting block 4 are offset in the circumferential direction of the fork shaft 11. The limiting mechanism 6 and the gear locking mechanism 3 are correspondingly offset in the circumferential direction of the fork shaft 11. The central axis of the limiting mechanism 6 and the central axis of the gear locking mechanism 3 are set at an angle, so that the limiting mechanism 6 avoids the oil passage.

[0092] Specifically, the limiting mechanism 6 can move radially along the fork shaft 11, thereby approaching or moving away from the second limiting block 7, and thus allowing the limiting mechanism 6 to extend into or disengage from the second groove 71.

[0093] The fork shaft 11 is located between two extreme positions on both sides of its own axis in the second gear position. By setting the limiting mechanism 6 and the second limiting block 7, the in-gear positioning function in the second gear position is realized. When the limiting mechanism 6 extends into the second groove 71, the position of the locking pin 32 corresponds to the position of the first groove 421. The locking pin 32 can be accurately inserted into the first groove 421, ensuring that the hydraulic shifting device shifts to the second gear position and realizes in-gear locking in the second gear position.

[0094] When the hydraulic shifting device needs to switch from the second gear to other gears, the limiting mechanism 6 can automatically or passively disengage from the second groove 71. After the locking pin 32 disengages from the first groove 421, the fork shaft 11 can move along its own axis under the push of hydraulic oil, thereby performing the shifting.

[0095] In a specific embodiment, such as Figure 7 As shown, the limiting mechanism 6 includes a second elastic member 61 and a positioning member 62 connected together. In the second stop position, at least part of the positioning member 62 is accommodated in the second groove 71.

[0096] like Figure 8 As shown, the second limiting block 7 includes a first surface 72 and a second surface 73. The first surface 72 and the second surface 73 are spaced apart along the axial direction of the fork shaft 11. The sidewall of the second groove 71 smoothly transitions with the first surface 72 and the second surface 73, respectively. The second groove 71 is an arc-shaped groove.

[0097] For example, the second elastic element 61 is a compression spring that extends radially along the fork shaft 11 and is capable of elastic deformation along the radial direction of the fork shaft 11.

[0098] The positioning member 62 is connected to one end of the second elastic member 61 near the second limiting block 7, and the positioning member 62 can extend into the second groove 71 under the elastic force of the second elastic member 61.

[0099] The sidewall of the second groove 71 is an arc-shaped surface, such as Figure 8 As shown, the first surface 72 and the second surface 73 are located on both sides of the second groove 71 in the axial direction of the fork shaft 11. The sidewalls of the second groove 71 are connected to the first surface 72 and the second surface 73 through arc surfaces, respectively, so as to achieve a smooth transition between the sidewalls of the second groove 71 and the first surface 72 and the second surface 73.

[0100] For example, when the hydraulic shifting device is in the first gear, the positioning member 62 abuts against the first surface 72; when the hydraulic shifting device is in the third gear, the positioning member 62 abuts against the second surface 73.

[0101] In this embodiment, when the hydraulic shifting device is in the second gear, the positioning member 62 is at least partially located in the second groove 71. If it is necessary to switch to the first gear or the third gear, the fork shaft 11 moves along its own axial direction. Under the guidance of the side wall of the second groove 71, the positioning member 62 moves relative to the second limiting block 7, thereby compressing the second elastic member 61 radially along the fork shaft 11, so that the positioning member 62 disengages from the second groove 71 along the arc surface, ensuring that the fork shaft 11 can smoothly perform axial movement and shifting.

[0102] Furthermore, when the hydraulic shifting device is in the first or third gear position, the positioning member 62 is not located in the second groove 71. If it is necessary to switch to the second gear position, the fork shaft 11 moves along its own axial direction, and the positioning member 62 moves relative to the second limiting block 7, thereby compressing the second elastic member 61 radially along the fork shaft 11, so that the positioning member 62 enters the second groove 71 along the arc surface, thus completing the shifting positioning of the second gear position.

[0103] In a further embodiment, the extended surfaces of the first surface 72 and the second surface 73 form an angle.

[0104] like Figure 8 As shown, the angle between the first surface 72 and the side wall of the fork shaft 11 is an obtuse angle, and the angle between the second surface 73 and the side wall of the fork shaft 11 is an obtuse angle. That is, both the first surface 72 and the second surface 73 are inclined surfaces that are inclined to the side wall of the fork shaft 11, and the extension surfaces of the first surface 72 and the second surface 73 have an angle between them.

[0105] By setting the extension surfaces of the first surface 72 and the second surface 73 to form an angle, when the hydraulic shifting device switches from the second gear to the first gear or the third gear, the positioning member 62 and the second limiting block 7 move relative to each other. Guided by the side wall and arc surface of the second groove 71, the positioning member 62 contacts the first surface 72 or the second surface 73 and gradually moves along the inclined surface, so that the positioning member 62 gradually moves away from the second groove 71, eliminating the step difference between the second limiting block 7 and the side wall of the fork shaft 11, which helps to reduce noise and ensures smooth shifting.

[0106] Furthermore, when the hydraulic shifting device is in the first or third gear, the positioning member 62 abuts against the first surface 72 or the second surface 73. The inclined surface makes the positioning member 62 need to overcome the elastic force of the second elastic member 61 to approach the second groove 71. Therefore, it hinders the hydraulic shifting device from disengaging to the second gear to a certain extent, thus playing a certain role in limiting the gear position.

[0107] In one specific embodiment, the positioning element 62 is a rotatable rolling body that can roll relative to the second limiting block 7.

[0108] For example, the positioning element 62 is a sphere or a cylinder.

[0109] In this embodiment, the positioning member 62 can roll on the surface of the second limiting block 7. The positioning member 62 and the second limiting block 7 have rolling friction. Compared with sliding friction, the energy loss and friction force are smaller, which helps to improve the shifting efficiency and ensure that the shifting is carried out normally.

[0110] This application also provides a gearbox, including the hydraulic shifting device that has been implemented in any of the above embodiments.

[0111] The gearbox provided in this application embodiment has a gear lock mechanism 3 that can move radially along the fork shaft 11, so that the gear lock mechanism 3 can change its state by moving, thereby locking or releasing the fork shaft 11; when the fork shaft 11 is locked by the gear lock mechanism 3, the fork shaft 11 cannot move along its own axis, thus realizing the functions of in-gear limit and anti-disengagement; when the fork shaft 11 is released by the gear lock mechanism 3, the fork shaft 11 can move along its own axis to shift gears.

[0112] This application also provides a vehicle including the gearbox provided in the above embodiments.

[0113] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0114] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only.

[0115] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A hydraulic shifting device, characterized in that, The hydraulic shifting device includes: The shift fork assembly (1) includes a connected fork shaft (11) and a shift fork (12); The hydraulic cylinder (2) includes a cylinder body (21), a first piston (22) and a second piston (23). The first piston (22) and the second piston (23) are respectively disposed at the two ends of the axial direction of the fork shaft (11). The first piston (22), the fork shaft (11) and the second piston (23) are movably disposed inside the cylinder body (21) along the axial direction of the fork shaft (11), and the inside of the cylinder body (21) is divided into a first oil chamber (21a), a fork shaft chamber (21c) and a second oil chamber (21b). A gear locking mechanism (3) is installed in the cylinder (21) and is configured to move radially along the fork shaft (11) to lock or release the fork shaft (11). The cylinder body (21) has an oil passage and a socket (25). The socket (25) is connected to the fork shaft cavity (21c). The gear locking mechanism (3) includes a first elastic element (31) and a locking pin (32) connected together. The locking pin (32) is movably inserted into the socket (25) and divides the oil passage into a first section (24a) and a second section (24b). The first section (24a) is connected to the first oil cavity (21a), and the second section (24b) is connected to the second oil cavity (21b). The hydraulic shifting device further includes a first limiting block (4), the first limiting block (4) includes a block body (41) and a boss (42) protruding from the block body (41). The block body (41) is disposed on the fork shaft (11). The end of the boss (42) is provided with a first groove (421). The boss (42) has a first limiting surface (422) and a second limiting surface (423) that are opposite to each other. The first limiting surface (422) and the second limiting surface (423) are distributed at intervals along the axial direction of the fork shaft (11). The hydraulic shifting device has a first gear, a second gear and a third gear. In the first gear, the locking pin (32) abuts against the first limiting surface (422); in the second gear, the locking pin (32) is inserted into the first groove (421); in the third gear, the locking pin (32) abuts against the second limiting surface (423). The hydraulic shifting device also includes a limiting mechanism (6) and a second limiting block (7); The limiting mechanism (6) is radially and retractably mounted on the cylinder body (21) along the fork shaft (11); The second limiting block (7) is disposed on the fork shaft (11). The second limiting block (7) and the first limiting block (4) are spaced apart along the axial direction of the fork shaft (11), and the second limiting block (7) and the first limiting block (4) are offset in the circumferential direction of the fork shaft (11). The second limiting block (7) has a second groove (71). In the second stop position, the limiting mechanism (6) extends into the second groove (71). The limiting mechanism (6) includes a second elastic member (61) and a positioning member (62) connected together. In the second stop position, at least part of the positioning member (62) is accommodated in the second groove (71). The second limiting block (7) includes a first surface (72) and a second surface (73). The first surface (72) and the second surface (73) are spaced apart along the axial direction of the fork shaft (11). The sidewall of the second groove (71) smoothly transitions with the first surface (72) and the second surface (73), respectively. The second groove (71) is an arc-shaped groove.

2. The hydraulic shifting device according to claim 1, characterized in that, The hydraulic shifting device also includes a first check valve (51) and a second check valve (52); The first check valve (51) is disposed between the first oil chamber (21a) and the first segment (24a), and the conduction direction of the first check valve (51) is from the first oil chamber (21a) to the first segment (24a); The second check valve (52) is disposed between the second oil chamber (21b) and the second section (24b), and the conduction direction of the second check valve (52) is from the second oil chamber (21b) to the second section (24b).

3. The hydraulic shifting device according to claim 1, characterized in that, The shape of the first groove (421) is adapted to the shape of the end of the locking pin (32).

4. The hydraulic shifting device according to claim 1, characterized in that, The extended surfaces of the first surface (72) and the second surface (73) form an angle.

5. The hydraulic shifting device according to claim 1, characterized in that, The positioning element (62) is a rotatable rolling body, and the positioning element (62) is able to roll relative to the second limiting block (7).

6. A gearbox, characterized in that, Includes the hydraulic shifting device as described in any one of claims 1 to 5.

7. A vehicle, characterized in that, Includes the gearbox as described in claim 6.

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