Piston applied to hydraulic system, control method of piston, hydraulic system and vehicle

Abstract

The invention provides a piston applied to a hydraulic system, a control method of the piston, the hydraulic system and a vehicle, and relates to the technical field of vehicle parts, the piston comprises a piston shell and a piston structure, and a piston cavity movably matched with the piston structure is formed in the piston shell; a groove is formed in the inner wall of the piston cavity, the side wall of the groove comprises a side wall first position part and a side wall second position part which face the same direction, and the side wall first position part and the side wall second position part are located at different axial positions and different circumferential positions of the piston shell; the piston structure comprises a piston body and a locking block, the locking block is connected to the peripheral face of the piston body and located in the groove, and the locking block is used for abutting against the side wall first position part or the side wall second position part in the axial direction of the piston body. According to the piston, self-locking of the piston structure at different axial positions in the piston cavity can be achieved, after the piston structure is self-locked, hydraulic force can be removed, energy is saved, consumption is reduced, and it is guaranteed that robustness of a hydraulic system is better.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle parts, and in particular to a piston used in a hydraulic system and a control method thereof, a hydraulic system, and a vehicle. Background Art

[0002] Automatic transmission plays an increasingly important role in the modern automobile industry, and the piston, as one of its core components, is crucial to the performance and reliability of the automatic transmission. The piston usually acts as an actuator in the hydraulic system of the automatic transmission. It is driven by hydraulic pressure and controls the operation of the terminal actuator such as the clutch. In other words, the role of the piston is to convert and transmit power in the hydraulic system of the automatic transmission. The position of the piston in the piston cavity can be changed by axial hydraulic thrust, thereby controlling the working state of the clutch and realizing the shifting process of the transmission. However, in traditional automatic transmissions, the position of the piston in the piston cavity generally requires continuous supply of axial hydraulic thrust, which consumes a lot of energy. Otherwise, the piston will directly reset to the original axial position along the axial direction; and if the hydraulic pipeline suddenly leaks or the hydraulic system fails, the piston will not be able to maintain the required position, and the robustness is poor. Summary of the invention

[0003] The present invention aims to solve at least one of the above technical problems.

[0004] In order to solve the above problems, the present invention provides a piston for use in a hydraulic system, comprising a piston housing and a piston structure, wherein a piston cavity is provided in the piston housing, and the piston structure is movably matched with the piston cavity;

[0005] The inner wall of the piston cavity is provided with a groove, the side wall of the groove comprises a first position side wall portion and a second position side wall portion facing the same direction, the first position side wall portion and the second position side wall portion are located at different axial positions of the piston housing, and the first position side wall portion and the second position side wall portion are located at different circumferential positions of the piston housing;

[0006] The piston structure includes a piston body and a locking block, wherein the locking block is connected to the outer peripheral surface of the piston body and is located in the groove, and the locking block is used to abut against the first position portion of the side wall or the second position portion of the side wall along the axial direction of the piston body.

[0007] The piston used in the hydraulic system provided by the present invention has a piston structure that is movably matched with the piston cavity of the piston housing, that is, the piston structure can move in any direction relative to the piston cavity (except radial movement). In addition, the side wall of the piston cavity is also provided with a groove, and the locking block of the piston structure is located in the groove, so the locking block can only move in the groove, and because the side wall of the groove includes a first position portion of the side wall and a second position portion of the side wall facing the same direction, and the locking block is used to abut against the first position portion of the side wall or the second position portion of the side wall along the axial direction of the piston body, that is, the first position portion of the side wall and the second position portion of the side wall are arranged axially toward the piston body, and are arranged toward the same end of the axial direction. In addition, the first position portion of the side wall and the second position portion of the side wall are not only at different positions in the circumferential direction of the piston housing, but also at different positions in the axial direction of the piston housing; in this way, when the locking block is in the axial direction of the piston housing, When the piston structure is in abutment with the first position portion of the side wall, the piston structure may be in a first position relative to the piston housing (the piston structure in this position is in a first axial position and a first circumferential position relative to the piston housing); when the axial position of the piston structure needs to be changed, the piston structure may be first axially moved to a target axial position (second axial position) by an axial hydraulic thrust, and the locking block moved to the second axial position is also separated from the first position portion of the side wall of the groove, and then the locking block in the second axial position may be circumferentially rotated to a second circumferential position by, for example, a circumferential hydraulic thrust or a mechanical rotation structure, so as to abut against the second position of the side wall of the groove, thereby achieving the second position of the piston structure relative to the piston housing.

[0008] In the present invention, when the piston structure is in the second position, the piston structure is in both the second axial position and the second circumferential position relative to the piston housing. At this time, the axial hydraulic thrust can be removed to achieve energy consumption reduction (the circumferential hydraulic thrust can also be removed at the same time). After the hydraulic thrust is removed, due to the limiting of the locking block by the second position portion of the side wall, the piston structure will not be reset to the first position along the axial direction; or, after the piston structure is in the second position, even if hydraulic leakage occurs, the piston structure will not be reset to the first position along the axial direction, but will remain in the second position, and the hydraulic system will have better robustness.

[0009] Furthermore, the piston applied to the hydraulic system also includes a return spring, which is used to provide an axial holding force to the piston structure so that the locking block is maintained in a state of abutting against the first position portion of the side wall or the second position portion of the side wall.

[0010] Furthermore, the two side walls of the groove spaced apart in the circumferential direction of the piston housing are respectively a first end wall and a second end wall, wherein the first position portion of the side wall and the second position portion of the side wall are located between the first end wall and the second end wall; a first flow channel and a second flow channel are provided in the side wall of the piston housing, one end of the first flow channel forms a first external liquid port on the surface of the piston housing, the other end of the first flow channel forms a first internal liquid port at the first end wall, one end of the second flow channel forms a second external liquid port on the surface of the piston housing, and the other end of the second oil channel forms a second internal liquid port at the second end wall.

[0011] Furthermore, the piston used in the hydraulic system has at least a first working state and a second working state; when in the first working state, the hydraulic system drives the liquid medium into the groove through the first flow channel, and recovers the liquid medium flowing out of the groove through the second flow channel; when in the second working state, the hydraulic system drives the liquid medium into the groove through the second flow channel, and recovers the liquid medium flowing out of the groove through the first flow channel.

[0012] Furthermore, a plane perpendicular to the axial direction of the piston housing is a setting plane, the first position portion of the side wall and the second position portion of the side wall are connected to form an inclined side wall, and the inclined side wall is arranged at an acute angle to the setting plane; the side wall of the locking block includes an inclined side surface arranged opposite to the inclined side wall, and the inclined side surface is parallel to the inclined side wall.

[0013] Furthermore, the angle between the inclined side wall and the setting surface is α, the static friction coefficient between the inclined side walls is μ, and μ≥cot(90°-α).

[0014] The present invention also provides a hydraulic system, comprising the piston and oil tank, a hydraulic power component and a three-position four-way reversing valve as described above, wherein the input end of the hydraulic power component is connected to the oil tank, the output end of the hydraulic power component is connected to a port of the three-position four-way reversing valve, the two-port of the three-position four-way reversing valve is connected to the first external liquid port, the three-port of the three-position four-way reversing valve is connected to the oil tank, and the four-port of the three-position four-way reversing valve is connected to the second external liquid port;

[0015] When the piston is in the first working state, one port of the three-position four-way reversing valve is connected to the second port, and the four-port of the three-position four-way reversing valve is connected to the three-port; when the piston is in the second working state, one port of the three-position four-way reversing valve is connected to the four-port, and the two-port of the three-position four-way reversing valve is connected to the three-port.

[0016] Furthermore, the hydraulic system further comprises a release bearing, one of an outer ring and an inner ring of the release bearing is connected to the piston structure, and the other of the outer ring and the inner ring is used to be connected to a clutch.

[0017] The present invention further provides a piston control method applied to a hydraulic system. Based on the piston applied to the hydraulic system as described above, the method comprises:

[0018] When the piston structure needs to move from the first position to the second position, the piston structure at the first circumferential position and the first axial position is controlled to move axially to the second axial position, and then the piston structure is controlled to rotate circumferentially to the second circumferential position, so that the locking block axially abuts against the second position portion of the side wall;

[0019] When the piston structure needs to move from the second position to the first position, the piston structure at the second circumferential position and the second axial position is controlled to rotate circumferentially to the first circumferential position, and then the piston structure is controlled to move axially to the first axial position so that the locking block axially abuts against the first position portion of the side wall.

[0020] Since the technical improvements and beneficial effects of the piston control method applied to the hydraulic system are at least the same as those of the piston applied to the hydraulic system, the piston control method applied to the hydraulic system will not be described in detail.

[0021] The present invention also provides a vehicle, comprising the piston applied to the hydraulic system as described above, or comprising the hydraulic system as described above.

[0022] Since the technical improvements and beneficial effects of the vehicle are at least the same as those of the piston applied to the hydraulic system or the hydraulic system, the vehicle will not be described in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the explosion structure of a piston applied to a hydraulic system according to an embodiment of the present invention;

[0024] Figure 2 It is a schematic cross-sectional structural diagram of a locking block in a first position according to an embodiment of the present invention;

[0025] Figure 3 It is a schematic cross-sectional structural diagram of a locking block according to an embodiment of the present invention when it is in a second axial position and a first circumferential position;

[0026] Figure 4 It is a schematic cross-sectional structural diagram of the locking block of the embodiment of the present invention when it is in the second position;

[0027] Figure 5 It is a schematic cross-sectional structure diagram of another piston housing according to an embodiment of the present invention;

[0028] Figure 6 It is a structural schematic diagram of a hydraulic system according to an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of force analysis when the locking block according to an embodiment of the present invention is in the second position;

[0030] Figure 8 The figure is a flow chart of a piston control method applied to a hydraulic system according to an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1. Piston housing; 11. Piston cavity; 12. Groove; 121. Inclined side wall; 1211. Side wall first position portion; 1212. Side wall second position portion; 122. First end wall; 123. Second end wall; 13. First flow channel; 14. Second flow channel; 2. Piston structure; 21. Piston body; 22. Lock block; 221. Inclined side; 31. Oil tank; 32. Hydraulic power component; 33. Three-position four-way reversing valve; 331. One-way port; 332. Two-way port; 333. Three-way port; 334. Four-way port; 34. First pipeline; 35. Second pipeline; 4. Release bearing. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] The Z axis in the accompanying drawings represents the vertical direction, that is, the up and down position, and the positive direction of the Z axis represents the top, and the reverse direction of the Z axis represents the bottom; the Y axis in the accompanying drawings represents the left and right positions, and the positive direction of the Y axis represents the left side, and the reverse direction of the Y axis represents the right side; the X axis in the accompanying drawings represents the longitudinal direction, that is, the front and back positions, and the positive direction of the X axis represents the front, and the reverse direction of the X axis represents the back. It should also be noted that the aforementioned Z axis, Y axis, and X axis are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0037] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0038] See also Figure 1-4 A piston used in a hydraulic system according to an embodiment of the present invention comprises a piston housing 1 and a piston structure 2, wherein a piston cavity 11 is provided in the piston housing 1, and the piston structure 2 is movably matched with the piston cavity 11;

[0039] The inner wall of the piston cavity 11 is provided with a groove 12, and the side wall of the groove 12 includes a first side wall portion 1211 and a second side wall portion 1212 facing the same direction, the first side wall portion 1211 and the second side wall portion 1212 are located at different axial positions of the piston housing 1, and the first side wall portion 1211 and the second side wall portion 1212 are located at different circumferential positions of the piston housing 1;

[0040] The piston structure 2 includes a piston body 21 and a locking block 22. The locking block 22 is connected to the outer peripheral surface of the piston body 21 and is located in the groove 12. The locking block 22 is used to abut against the first position portion 1211 or the second position portion 1212 of the side wall along the axial direction of the piston body 21.

[0041] The piston used in the hydraulic system provided in this embodiment has a piston structure 2 that is movably matched with the piston cavity 11 of the piston housing 1, that is, the piston structure 2 can move in any direction relative to the piston cavity 11 (except radial movement). In addition, the side wall of the piston cavity 11 is also provided with a groove 12, and the locking block 22 of the piston structure 2 is located in the groove 12, so the locking block 22 can only move in the groove 12, and since the side wall of the groove 12 includes a side wall first position portion 1211 and a side wall second position portion 1212 facing the same direction, and the locking block 22 is used to abut against the side wall first position portion 1211 or the side wall second position portion 1212 along the axial direction of the piston body 21, that is, the side wall first position portion 1211 and the side wall second position portion 1212 are facing the piston body. The piston structure 2 is axially arranged in the piston housing 1 and is arranged toward the same end in the axial direction. In addition, the side wall first position portion 1211 and the side wall second position portion 1212 are not only at different positions in the circumferential direction of the piston housing 1, but also at different positions in the axial direction of the piston housing 1; thus, when the locking block 22 is in contact with the side wall first position portion 1211 in the axial direction of the piston housing 1, the piston structure 2 can be in the first position relative to the piston housing 1 (the piston structure 2 in this position is in the first axial position and the first circumferential position relative to the piston housing 1, such as Figure 2 When the axial position of the piston structure 2 needs to be changed, the piston structure 2 can be first moved axially to the target axial position (the second axial position, such as Figure 3 The locking block 22 moved to the second axial position is also separated from the first position portion 1211 of the side wall of the groove 12. Then, the locking block 22 in the second axial position can be rotated circumferentially to the second circumferential position by, for example, circumferential hydraulic thrust or a mechanical rotation structure to abut against the second position of the side wall of the groove 12 (as shown in FIG. Figure 4 As shown), the piston structure 2 is thereby placed in a second position relative to the piston housing 1.

[0042] In this embodiment, when the piston structure 2 is in the second position, the piston structure 2 is in both the second axial position and the second circumferential position relative to the piston housing 1. At this time, the axial hydraulic thrust can be removed to achieve energy consumption reduction (the circumferential hydraulic thrust can also be removed at the same time). After the hydraulic thrust is removed, due to the limiting effect of the locking block 22 by the second position portion 1212 of the side wall, the piston structure 2 will not be reset to the first position along the axial direction; or, after the piston structure 2 is in the second position, even if hydraulic leakage occurs, the piston structure 2 will not be reset to the first position along the axial direction, but will remain in the second position, and the hydraulic system will have better robustness.

[0043] It should be noted that the side wall of the groove 12 includes a first side wall portion 1211 and a second side wall portion 1212 facing the same direction, wherein “facing the same direction” means that the first side wall portion 1211 and the second side wall portion 1212 are located on the same side of the groove. Figure 5 As shown, one side wall (front side wall) of the groove 12 along the axial direction of the piston housing 1 includes two parts perpendicular to the axial direction of the piston housing 1, namely, the first position part 1211 of the side wall and the second position part 1212 of the side wall; at this time, the extension directions of the first position part 1211 of the side wall and the second position part 1212 of the side wall can be parallel, and the orientation directions of the first position part 1211 of the side wall and the second position part 1212 of the side wall are both toward the other side wall (rear side wall) of the axial direction of the piston housing 1 of the groove 12, that is, the orientation directions of the first position part 1211 of the side wall and the second position part 1212 of the side wall are both toward the negative direction of the X-axis. For another example Figure 1-4 As shown, the extension directions of the first position portion 1211 of the side wall and the second position portion 1212 of the side wall are not only parallel, but also in the same extension direction, that is, the first position portion 1211 of the side wall and the second position portion 1212 of the side wall are connected to form an inclined side wall 121.

[0044] Optionally, the piston applied to the hydraulic system also includes a return spring (not shown in the figure), which is used to provide an axial retaining force to the piston structure 2 so that the locking block 22 remains in a state of abutting against the first position portion 1211 of the side wall or the second position portion 1212 of the side wall.

[0045] In this embodiment, the return spring always applies force to the piston structure 2 in the positive direction of the X-axis, that is, the return spring always applies force to the lock block 22 to move toward the front side wall of the groove 12, so as to ensure that the lock block 22 remains in contact with the first position portion 1211 of the side wall or the second position portion 1212 of the side wall, thereby preventing the lock block 22 from erroneously moving. The return spring can be installed in the piston cavity 11, one end of which is connected to a side wall of the piston cavity 11 away from the piston structure 2, and the other end is connected to the piston structure 2 (specifically, to the piston body). The return spring in this position is always in an elongated state, and is used to apply force to the piston structure 2 to move axially toward the first axial position.

[0046] Of course, even without the return spring, the piston structure 2 can remain locked in the second position under the friction force of the second position portion 1212 of the side wall, and will not be reset to the first position along the axial direction. The setting of the return spring can make the position locking of the piston structure 2 more stable and reliable. In addition, since the piston structure 2 of the piston is used to connect with the clutch, and the clutch generally includes a spring for clutch reset, even without the return spring of this embodiment, the spring for clutch reset in the clutch can make the position locking of the piston structure 2 more stable and reliable.

[0047] Specifically, when the locking block 22 abuts against the first position portion 1211 of the side wall (ie, when the locking block 22 is in the first position, Figure 2 As shown), under the action of the reset spring, the elastic force of the reset spring will keep the lock block 22 in the first position; when the axial position of the piston structure 2 needs to be changed, the piston structure 2 can be first axially moved to the second axial position (as shown) by the axial hydraulic thrust in the negative direction of the X-axis. Figure 3 As shown), the locking block 22 in the second axial position can then be rotated circumferentially to the second circumferential position by, for example, circumferential hydraulic thrust or a mechanical rotation structure to abut against the second position of the side wall of the groove 12 (as shown in FIG. Figure 4 As shown in FIG. 1 , under the elastic force of the return spring, the lock block 22 can be kept in a state of abutting against the second position portion 1212 of the side wall, that is, the lock block 22 can be kept in a state of abutting against the second position. After that, the axial hydraulic thrust and the circumferential hydraulic thrust can be removed to achieve energy saving and consumption reduction.

[0048] Alternatively, see Figure 1-5 The two side walls of the groove 12 spaced apart in the circumferential direction of the piston housing 1 are respectively a first end wall 122 and a second end wall 123, wherein the first position portion 1211 of the side wall and the second position portion 1212 of the side wall are located between the first end wall 122 and the second end wall 123; a first flow channel 13 and a second flow channel 14 are provided in the side wall of the piston housing 1, one end of the first flow channel 13 forms a first external liquid port on the surface of the piston housing 1, the other end of the first flow channel 13 forms a first internal liquid port at the first end wall 122, one end of the second flow channel 14 forms a second external liquid port on the surface of the piston housing 1, and the other end of the second oil channel forms a second internal liquid port at the second end wall 123.

[0049] In this embodiment, the two side walls of the groove 12 distributed along the circumference of the piston housing 1 are respectively the first end wall 122 and the second end wall 123, and the aforementioned side wall first position portion 1211 and the side wall second position portion 1212 are located between the first end and the second end wall 123. On this basis, the side walls of the piston housing 1 are respectively provided with a first flow channel 13 and a second flow channel 14, one end of the first flow channel 13 forms a first external liquid port on the surface of the piston housing 1, for example, a first external liquid port is formed on the front end face of the piston housing 1, the other end of the first flow channel 13 forms a first internal liquid port at the first end wall 122, one end of the second flow channel 14 forms a second external liquid port on the surface of the piston housing 1, for example, a second external liquid port is formed on the front end face of the piston housing 1, and the other end of the second oil channel forms a second internal liquid port at the second end wall 123.

[0050] Thus, when the piston structure 2 needs to be moved from the first position to the second position, the piston structure 2 can be first moved axially to the second axial position (such as Figure 3 As shown), the circumferentially rotating liquid medium can then be supplied into the groove 12 through the first flow channel 13. After the circumferentially rotating liquid medium enters the groove 12 from the first internal liquid port, it will push the locking block 22 at the second axial position to rotate circumferentially until the locking block 22 is in contact with the second position portion 1212 of the side wall, thereby finally realizing the movement of the piston structure 2 to the second position.

[0051] When it is necessary to move the piston structure 2 from the second position to the first position, the piston structure 2 can be kept in the second axial position by axial hydraulic thrust, and a circumferentially rotating liquid medium can be supplied into the groove 12 through the second flow channel 14. After the circumferentially rotating liquid medium enters the groove 12 from the second internal liquid port, it will push the locking block 22 in the second position to rotate circumferentially to the first circumferential position. Then the axial hydraulic thrust is removed, and under the action of the reset spring, the locking block 22 will move to the first position.

[0052] It should be noted that the locking block 22 has two side surfaces along the circumference of the piston body 21, namely, a first side surface and a second side surface, wherein the first side surface refers to a side surface close to the first end surface of the groove 12, and the second side surface refers to a side surface close to the second end surface of the groove 12. Figure 3 When the locking block 22 is in the position shown in the figure (i.e., the locking block 22 is in the first circumferential position and the second axial position), after the circumferentially rotating liquid medium is ejected from the first inner liquid port, since the first side surface of the locking block 22 is the force-bearing surface that bears the rotating hydraulic pressure, the locking block 22 will rotate toward the second inner liquid port until it is in the second position abutting against the second position portion 1212 of the side wall; similarly, when the locking block 22 is in the Figure 4In the second position shown in FIG. 1 , after the circumferentially rotating liquid medium is ejected from the second inner liquid port, the locking block 22 will rotate toward the first inner liquid port until it is in the second position. Figure 3 The position shown in the figure, the axial hydraulic thrust can be removed (of course, the circumferential rotary hydraulic pressure can also be removed at the same time), and under the action of the reset spring, the locking block 22 will be reset to the first position.

[0053] Optionally, the piston has at least a first working state and a second working state; when in the first working state, the hydraulic system drives the liquid medium into the groove 12 through the first flow channel 13, and recovers the liquid medium flowing out of the groove 12 through the second flow channel 14; when the system is in the second working state, the hydraulic system drives the liquid medium into the groove 12 through the second flow channel 14, and recovers the liquid medium flowing out of the groove 12 through the first flow channel 13.

[0054] In this embodiment, the circumferential hydraulic thrust for the rotation of the lock block 22 is provided by the hydraulic system. The piston, or the hydraulic system, has at least two working states, namely, at least a first working state and a second working state. When the piston or the hydraulic system is in the first working state, the hydraulic system allows the liquid medium to enter the groove 12 through the first flow channel 13, and flows out of the groove 12 through the second flow channel 14, thereby realizing the rotation of the lock block 22 in the direction of the second end wall 123; when the piston or the hydraulic system is in the second working state, the hydraulic system allows the liquid medium to enter the groove 12 through the second flow channel 14, and flows out of the groove 12 through the first flow channel 13, thereby realizing the rotation of the lock block 22 in the direction of the first end wall 122. Finally, the hydraulic system provides hydraulic pressure to drive the lock block 22 to rotate circumferentially. The liquid medium may be hydraulic oil.

[0055] See also Figure 6 Since the piston is applied to a hydraulic system, another embodiment of the present invention further provides a hydraulic system, which includes the aforementioned piston and an oil tank 31, a hydraulic power component 32 and a three-position four-way reversing valve 33, wherein the input end of the hydraulic power component 32 is connected to the oil tank 31, the output end of the hydraulic power component 32 is connected to a first port 331 of the three-position four-way reversing valve 33, the second port 332 of the three-position four-way reversing valve 33 is connected to the first external liquid port, the three-port 333 of the three-position four-way reversing valve 33 is connected to the oil tank 31, and the four-port 334 of the three-position four-way reversing valve 33 is connected to the second external liquid port;

[0056] When the piston is in the first working state, that is, the hydraulic system is in the first working state, the first port 331 of the three-position four-way reversing valve 33 is connected with the second port 332, and the four-port 334 of the three-position four-way reversing valve 33 is connected with the three-port 333; when the piston is in the second working state, that is, the hydraulic system is in the second working state, the first port 331 of the three-position four-way reversing valve 33 is connected with the four-port 334, and the two-port 332 of the three-position four-way reversing valve 33 is connected with the three-port 333.

[0057] In this embodiment, when the piston structure 2 needs to be moved from the first position to the second position, the piston structure 2 can be first moved axially to the second axial position (such as Figure 3 Then the piston or hydraulic system can be placed in the first working state, that is, the three-position four-way reversing valve 33 is in Figure 6 In the left position, at this time, the first port 331 is connected with the second port 332, the fourth port 334 is connected with the third port 333, and then the hydraulic power part 32, for example, the oil is supplied by the oil pump, and the hydraulic oil will enter the groove 12 through the first port 331, the second port 332, the first external liquid port and the first internal liquid port in sequence, and then return to the oil tank 31 through the second internal liquid port, the second external liquid port, the fourth port 334 and the third port 333 in sequence. In the process of the hydraulic oil flowing, the locking block 22 is moved by Figure 3 Push the rotation to the position Figure 4 The second position is shown.

[0058] When the piston structure 2 needs to be moved from the second position to the first position, the piston or the hydraulic system can be placed in the second working state, that is, the three-position four-way reversing valve 33 is placed in the second working state. Figure 6 In the right position, at this time, the first port 331 is connected with the four-way port 334, the second port 332 is connected with the three-way port 333, and then the oil is supplied by the oil pump, and the hydraulic oil will enter the groove 12 through the first port 331, the four-way port 334, the second external liquid port and the second internal liquid port in sequence, and then return to the oil tank 31 through the first internal liquid port, the first external liquid port, the second port 332 and the three-way port 333 in sequence. In the process of hydraulic oil flowing, the lock block 22 is Figure 4 Push the rotation to the position Figure 3 Position shown.

[0059] It should be noted that when the locking block 22 is required to rotate circumferentially, the locking block 22 can be kept in the second axial position by the axial hydraulic thrust to ensure that the locking block 22 will not be affected by the reset spring and move in the axial direction when the locking block 22 rotates circumferentially; when the locking block 22 has been rotated circumferentially to the required second circumferential position (which also means that the locking block 22 is in the second axial position), the axial hydraulic thrust can be removed; it can be understood that in the process of the locking block 22 being reset from the second position to the first position by the piston structure 2, when the locking block 22 is Figure 4 Rotate to Figure 3 After the position shown in the figure is reached, the axial hydraulic thrust is also removed, and then under the action of the return spring, the locking block 22 is reset to Figure 2 First position shown.

[0060] It can be understood that the three-position four-way reversing valve 33 has a left position (corresponding to the first working state of the piston or the hydraulic system) and a right position (corresponding to the second working state of the piston or the hydraulic system), and also has a middle position. Figure 6 The three-position four-way reversing valve 33 shown is in the middle position), the various ports are disconnected from each other, and the hydraulic oil does not pass through; therefore, the hydraulic pressure for circumferential rotation can be removed by placing the three-position four-way reversing valve 33 in the middle position.

[0061] The three-position four-way reversing valve 33 can be an electromagnetic reversing valve, which is convenient for adjusting its working position to the left, right or middle position. The hydraulic power part 32 can be an accumulator or other parts capable of generating or storing hydraulic energy in addition to an oil pump. Figure 6 As shown, the second port 332 of the three-position four-way reversing valve 33 can be connected to the first external liquid port of the first flow channel 13 through the first pipeline 34 , and the four-way port 334 can be connected to the second external liquid port of the second flow channel 14 through the second pipeline 35 .

[0062] It can be understood that when the piston structure 2 rotates circumferentially, the locking block 22 is directly subjected to force, while when the piston structure 2 moves axially, the piston body 21 is directly subjected to force.

[0063] Alternatively, see Figure 1-4 In this piston, the plane perpendicular to the axial direction of the piston housing 1 is the setting plane (YZ plane), the first position part 1211 of the side wall and the second position part 1212 of the side wall are connected to form an inclined side wall 121, and the inclined side wall 121 is set at an acute angle to the setting plane; the side wall of the locking block 22 includes an inclined side surface 221 opposite to the inclined side wall 121, and the inclined side surface 221 is parallel to the inclined side wall 121.

[0064] In this embodiment, it is preferred that Figure 1-4As shown, the extension directions of the first position portion 1211 of the side wall and the second position portion 1212 of the side wall are parallel and are located on the same extension plane, that is, the first position portion 1211 of the side wall and the second position portion 1212 of the side wall are connected to form an inclined side wall 121, and the extension plane where the inclined side wall 121 is located is set at an acute angle to the set plane.

[0065] Furthermore, since the inclined side surface 221 is parallel to the inclined side wall 121 of the locking block 22, when the locking block 22 is Figure 3 Rotate the position shown to Figure 4 During the process of moving the locking block 22 to the second position, the inclined side surface 221 of the locking block 22 will not contact or rub against the inclined side wall 121. When the inclined side surface 221 of the locking block 22 rotates to contact the inclined side wall 121 of the groove 12, the locking block 22 is moved to the second position. Figure 4 The second position shown is rotated to Figure 3 During the process of changing the position shown in the figure, at the moment when the lock block 22 rotates, the inclined side surface 221 of the lock block 22 will separate from the inclined side wall 121, so that there will be no friction. That is, as long as the lock block 22 is not in the first position or the second position, the movement of the lock block 22 will not contact and rub against the inclined side wall 121, which can reduce the friction loss between the lock block 22 and the piston housing 1 and reduce the size of the circumferential rotation hydraulic thrust required when the lock block 22 rotates circumferentially.

[0066] Moreover, since the inclined side surface 221 is parallel to the inclined side wall 121, the inclined side surface 221 of the locking block 22 can be completely in contact with the inclined side wall 121 when the locking block 22 is in the first position or the second position, ensuring that the force bearing area therebetween is sufficient, thereby ensuring the stability of the locking block 22 in the first position or the second position.

[0067] Alternatively, see Figure 7 In the piston, the angle between the inclined side wall 121 and the setting surface is α, and the static friction coefficient between the inclined side wall 121 and the inclined side surface 221 is μ, μ≥cot(90°-α).

[0068] In this embodiment, the angle between the inclined side wall 121 and the setting surface is α, that is, the angle between the inclined side wall 121 and the axial direction of the piston housing 1 is 90°-α, and (90°-α)=θ. Here, the relationship between μ and α is μ≥cot(90°-α), which is equivalent to μ≥cotθ, so as to ensure that when the locking block 22 is in the second position, the static friction between the inclined side surface 221 of the locking block 22 and the inclined side wall 121 of the groove 12 can ensure that the locking block 22 is self-locked in this position. The analysis is as follows: When the locking block 22 is in the second position, as Figure 7 As shown, the axial hydraulic thrust can be removed (i.e., F 轴=0), the force on the piston structure 2 in the axial direction is equal to the elastic force F of the return spring. 弹 For example, its direction is the axial direction of the piston housing 1, so F 弹 Two components of force are formed, namely, F along the extending direction of the inclined side wall 121 and 旋 and the positive pressure N=F perpendicular to the extending direction of the inclined side wall 121 弹 × sinθ, where N × μ = f (i.e. static friction), and F 旋 =F 弹 ×cosθ,N=F 弹 × sinθ, so f=F 弹 × sinθ×μ; In order to make the locking block 22 self-lock in the second position by the elastic force of the return spring, it is necessary to ensure that f≥F 旋 , so it is necessary to ensure μ ≥ cotθ.

[0069] Alternatively, see Figure 1 The hydraulic system with the piston further includes a release bearing 4, one of the outer ring and the inner ring of the release bearing 4 is connected to the piston structure 2, and the other of the outer ring and the inner ring is used to connect to a clutch (not shown in the figure).

[0070] In this embodiment, since the piston is connected to the clutch to drive the clutch to engage or disengage, the piston structure 2 can be connected to the clutch through the release bearing 4, thereby ensuring that the piston structure 2 only transmits axial force to the clutch, and the rotational movement of the piston structure 2 will not be restricted by the clutch. That is, the clutch is engaged or disengaged along the axial direction of the piston structure 2, and the movement of the piston structure 2 between the first position and the second position involves not only axial movement but also circumferential rotation. Therefore, the piston structure 2 is connected to the outer ring of the release bearing 4, for example, and the clutch can be connected to the inner ring of the release bearing 4. In this way, when the piston structure 2 changes its position in the axial direction, it will drive the clutch to make corresponding movements, and when the piston structure 2 rotates circumferentially, the piston structure 2 rotates with the outer ring of the release bearing 4, but the inner ring of the release bearing 4 and the clutch may not rotate.

[0071] Another embodiment of the present invention further provides a piston control method for a hydraulic system, based on the piston for a hydraulic system as described above. Figure 8 As shown, the method includes:

[0072] When the piston structure 2 needs to move from the first position to the second position, the piston structure 2 at the first circumferential position and the first axial position is controlled to move axially to the second axial position, and then the piston structure 2 is controlled to rotate circumferentially to the second circumferential position, so that the locking block 22 axially abuts against the second position portion 1212 of the side wall;

[0073] When the piston structure 2 needs to move from the second position to the first position, the piston structure 2 at the second circumferential position and the second axial position is controlled to rotate circumferentially to the first circumferential position, and then the piston structure 2 is controlled to move axially to the first axial position, so that the locking block 22 axially abuts against the first position portion 1211 of the side wall.

[0074] Since the piston control method applied to the hydraulic system is based on the aforementioned piston applied to the hydraulic system, the technical improvements and beneficial effects of the piston control method applied to the hydraulic system are at least the same as those of the aforementioned piston applied to the hydraulic system, and therefore the piston control method applied to the hydraulic system will not be described in detail.

[0075] Still another embodiment of the present invention provides a vehicle, comprising the piston applied to the hydraulic system as described above, or comprising the hydraulic system as described above.

[0076] Since the technical improvements and beneficial effects of the vehicle are at least the same as those of the piston applied to the hydraulic system or the hydraulic system, the vehicle will not be described in detail.

[0077] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one of the features.

[0078] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A piston used in a hydraulic system, characterized in that: It comprises a piston housing (1) and a piston structure (2), wherein a piston cavity (11) is provided in the piston housing (1), and the piston structure (2) is movably matched with the piston cavity (11); The inner wall of the piston cavity (11) is provided with a groove (12); the side wall of the groove (12) comprises a first side wall position portion (1211) and a second side wall position portion (1212) facing the same direction; the first side wall position portion (1211) and the second side wall position portion (1212) are located at different axial positions of the piston housing (1); and the first side wall position portion (1211) and the second side wall position portion (1212) are located at different circumferential positions of the piston housing (1); The piston structure (2) comprises a piston body (21) and a locking block (22), wherein the locking block (22) is connected to the outer peripheral surface of the piston body (21) and is located in the groove (12), and the locking block (22) is used to abut against the first position portion (1211) of the side wall or the second position portion (1212) of the side wall along the axial direction of the piston body (21).

2. The piston used in a hydraulic system according to claim 1, characterized in that: It also includes a return spring, which is used to provide an axial retaining force to the piston structure (2) so that the locking block (22) is maintained in a state of abutting against the first position portion (1211) of the side wall or the second position portion (1212) of the side wall.

3. The piston used in a hydraulic system according to claim 1, characterized in that: The two side walls of the groove (12) spaced apart in the circumferential direction of the piston housing (1) are respectively a first end wall (122) and a second end wall (123), wherein the first position portion (1211) of the side wall and the second position portion (1212) of the side wall are located between the first end wall (122) and the second end wall (123); a first flow channel (13) and a second flow channel (14) are arranged in the side wall of the piston housing (1), one end of the first flow channel (13) forms a first external liquid port on the surface of the piston housing (1), the other end of the first flow channel (13) forms a first internal liquid port at the first end wall (122), one end of the second flow channel (14) forms a second external liquid port on the surface of the piston housing (1), and the other end of the second oil channel forms a second internal liquid port at the second end wall (123).

4. The piston used in a hydraulic system according to claim 3, characterized in that: The hydraulic system has at least a first working state and a second working state; when in the first working state, the hydraulic system drives the liquid medium to enter the groove (12) through the first flow channel (13), and recovers the liquid medium flowing out of the groove (12) through the second flow channel (14); when in the second working state, the hydraulic system drives the liquid medium to enter the groove (12) through the second flow channel (14), and recovers the liquid medium flowing out of the groove (12) through the first flow channel (13).

5. The piston for use in a hydraulic system according to claim 1, characterized in that: A plane perpendicular to the axial direction of the piston housing (1) is a setting plane, the first position portion (1211) of the side wall and the second position portion (1212) of the side wall are connected to form an inclined side wall (121), and the inclined side wall (121) is arranged at an acute angle with the setting plane; the side wall of the locking block (22) includes an inclined side surface (221) arranged opposite to the inclined side wall (121), and the inclined side surface (221) is parallel to the inclined side wall (121).

6. The piston for use in a hydraulic system according to claim 5, characterized in that: The angle between the inclined side wall (121) and the setting surface is α, and the static friction coefficient between the inclined side wall (121) and the inclined side wall (121) is μ, where μ≥cot(90°-α).

7. A hydraulic system, characterized in that: The hydraulic system comprises a piston as claimed in any one of claims 1 to 6, as well as an oil tank (31), a hydraulic power component (32) and a three-position four-way reversing valve (33), wherein an input end of the hydraulic power component (32) is connected to the oil tank (31), an output end of the hydraulic power component (32) is connected to a first port (331) of the three-position four-way reversing valve (33), a second port (332) of the three-position four-way reversing valve (33) is connected to a first external liquid port of the piston, a three-port (333) of the three-position four-way reversing valve (33) is connected to the oil tank (31), and a four-port (334) of the three-position four-way reversing valve (33) is connected to a second external liquid port of the piston; When the piston is in the first working state, the first port (331) of the three-position four-way reversing valve (33) is connected to the second port (332), and the fourth port (334) of the three-position four-way reversing valve (33) is connected to the third port (333); when the piston is in the second working state, the first port (331) of the three-position four-way reversing valve (33) is connected to the fourth port (334), and the second port (332) of the three-position four-way reversing valve (33) is connected to the third port (333).

8. The hydraulic system according to claim 7, characterized in that: It also includes a release bearing (4), one of the outer ring and the inner ring of the release bearing (4) is connected to the piston structure (2), and the other of the outer ring and the inner ring is used to be connected to the clutch.

9. A piston control method for a hydraulic system, based on the piston for a hydraulic system according to any one of claims 1 to 6, characterized in that: include: When the piston structure (2) needs to move from the first position to the second position, the piston structure (2) at the first circumferential position and the first axial position is controlled to move axially to the second axial position, and then the piston structure (2) is controlled to rotate circumferentially to the second circumferential position, so that the locking block (22) is axially abutted against the second position portion (1212) of the side wall; When the piston structure (2) is required to move from the second position to the first position, the piston structure (2) at the second circumferential position and the second axial position is controlled to rotate circumferentially to the first circumferential position, and then the piston structure (2) is controlled to move axially to the first axial position, so that the locking block (22) is axially abutted against the first position portion (1211) of the side wall.

10. A vehicle, characterized in that: The invention comprises a piston applied to a hydraulic system as claimed in any one of claims 1 to 6, or comprises a hydraulic system as claimed in any one of claims 7 to 8.

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