Piston for a hydraulic system, method for controlling a piston, hydraulic system, vehicle

Abstract

The application provides a piston applied to a hydraulic system, a control method of the piston, the hydraulic system and a vehicle, relates to the technical field of vehicle parts, and the piston comprises a piston shell and a piston structure, and a piston cavity in movable cooperation with the piston structure is arranged in the piston shell; an inner wall of the piston cavity is provided with a groove, a side wall of the groove comprises a side wall first position part and a side wall second position part which are directed to 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 lock block, the lock block is connected to an outer circumferential surface of the piston body and located in the groove, and the lock 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. The piston can realize self-locking of the piston structure at different axial positions in the piston cavity, after the piston structure is self-locked, the hydraulic pressure can be removed, energy consumption is reduced, and the robustness of the hydraulic system is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle parts, in particular to a piston applied to a hydraulic system, a control method of the piston, a hydraulic system and a vehicle. BACKGROUND

[0002] Automatic transmissions play an increasingly important role in the modern automotive industry, and as one of the core components, the piston is crucial to the performance and reliability of the automatic transmission. The piston usually plays the role of an actuator in the hydraulic system of the automatic transmission, which is driven by hydraulic pressure to control the working state of the end actuator such as the clutch, that is, the piston functions 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 the axial hydraulic thrust, thereby controlling the working state of the clutch to realize the gear shifting process of the transmission. However, in the conventional automatic transmission, the position of the piston in the piston cavity is maintained, which generally requires continuous supply of axial hydraulic thrust, resulting in high energy consumption, otherwise the piston will be directly reset to the original axial position along the axial direction. Moreover, 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

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

[0004] To solve the above problems, the present application provides a piston applied to a hydraulic system, comprising a piston shell and a piston structure, wherein the piston shell is provided with a piston cavity, and the piston structure is movably fitted in the piston cavity.

[0005] The inner wall of the piston cavity is provided with a groove, and the side wall of the groove comprises a side wall first position part and a side wall second position part which are directed to the same side wall. The side wall first position part and the side wall second position part are located at different axial positions of the piston shell, and the side wall first position part and the side wall second position part are located at different circumferential positions of the piston shell.

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

[0007] The application provides a piston applied to a hydraulic system, wherein the piston structure is movably matched with a piston cavity of a piston shell, that is, the piston structure can move in any direction (except radial movement) relative to the piston cavity; and a side wall of the piston cavity is provided with a groove, and a locking block of the piston structure is located in the groove, so that the locking block can only move in the groove; and the side wall of the groove comprises a side wall first position part and a side wall second position part which are towards the same side wall, and the locking block is used to abut against the side wall first position part or the side wall second position part along the axial direction of the piston body, that is, the side wall first position part and the side wall second position part are arranged towards the axial direction of the piston body and are arranged towards the same end of the axial direction, and in addition, the side wall first position part and the side wall second position part are not only located at different positions in the circumferential direction of the piston shell, but also are located at different positions in the axial direction of the piston shell; in this way, when the locking block abuts against the side wall first position part in the axial direction of the piston shell, the piston structure can be located at a first position relative to the piston shell (in this position, the piston structure is located at a first axial position and a first circumferential position relative to the piston shell); when it is required to change the axial position of the piston structure, the piston structure can be axially moved to a target axial position (a second axial position) by an axial hydraulic thrust, the locking block moved to the second axial position is separated from the side wall first position part of the groove, and then the locking block in the second axial position can be circumferentially rotated to a second circumferential position by a circumferential hydraulic thrust or a mechanical rotating structure, so as to abut against the side wall second position of the groove, thereby realizing that the piston structure is located at a second position relative to the piston shell.

[0008] In the application, when the piston structure is located at the second position, the piston structure is located at both a second axial position relative to the piston shell and a second circumferential position relative to the piston shell, at this time, the axial hydraulic thrust can be removed to realize energy saving (the circumferential hydraulic thrust can also be removed at the same time), and after the hydraulic thrust is removed, the piston structure cannot be reset to the first position along the axial direction due to the limitation of the side wall second position part on the locking block; or, after the piston structure is located at the second position, even if hydraulic leakage occurs, the piston structure cannot be reset to the first position along the axial direction, but is kept at the second position, so that the robustness of the hydraulic system is better.

[0009] Further, the piston applied to the hydraulic system further comprises a reset spring which is used to give an axial keeping force to the piston structure, so that the locking block is kept in the state of abutting against the side wall first position part or the side wall second position part.

[0010] Further, the two side walls of the groove are a first end wall and a second end wall, respectively, and the first position part and the second position part are located between the first end wall and the second end wall; the first flow channel and the second flow channel are arranged 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 flow channel forms a second internal liquid port at the second end wall.

[0011] Further, the piston applied to 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 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 to enter the groove through the second flow channel and recovers the liquid medium flowing out of the groove through the first flow channel.

[0012] Further, the plane perpendicular to the axial direction of the piston housing is a setting plane, the first position part and the second position part are connected to form an inclined side wall, and the inclined side wall is arranged at an acute angle with the setting plane; the side wall of the lock 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] Further, the angle between the inclined side wall and the setting plane is α, and the static friction coefficient between the inclined side wall and the inclined side wall is μ, μ≥cot(90°-α).

[0014] The application further provides a hydraulic system including the piston and an oil tank, a hydraulic power component and a three-position four-way directional valve, the input end of the hydraulic power component is connected with the oil tank, the output end of the hydraulic power component is connected with one port of the three-position four-way directional valve, the second port of the three-position four-way directional valve is connected with the first external liquid port, the third port of the three-position four-way directional valve is connected with the oil tank, and the fourth port of the three-position four-way directional valve is connected with the second external liquid port.

[0015] When the piston is in the first working state, one port of the three-position four-way directional valve is in communication with the second port, and the fourth port of the three-position four-way directional valve is in communication with the third port; when the piston is in the second working state, one port of the three-position four-way directional valve is in communication with the fourth port, and the second port of the three-position four-way directional valve is in communication with the third port.

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

[0017] The application 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 in 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 lock block axially abuts against the second position part of the side wall;

[0019] When the piston structure needs to move from the second position to the first position, the piston structure in 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 lock block axially abuts against the first position part of the side wall.

[0020] Since the technical improvement and beneficial effect 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 again.

[0021] The application further 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 improvement and beneficial effect 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 again. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is an exploded structural schematic view of the piston applied to the hydraulic system in the embodiment of the application;

[0024] Figure 2 It is a sectional structural schematic view of the lock block in the first position;

[0025] Figure 3 It is a sectional structural schematic view of the lock block in the second axial position and the first circumferential position;

[0026] Figure 4 It is a sectional structural schematic view of the lock block in the second position;

[0027] Figure 5 It is a sectional structural schematic view of another piston shell in the embodiment of the application;

[0028] Figure 6 Fig. 1 is a structural schematic diagram of a hydraulic system according to an embodiment of the present application;

[0029] Figure 7 Fig. 2 is a force analysis schematic diagram of a lock block in a second position according to an embodiment of the present application;

[0030] Figure 8 Fig. 3 is a flow schematic diagram of a piston control method applied to a hydraulic system according to an embodiment of the present application.

[0031] Legend of reference signs:

[0032] 1, piston housing; 11, piston cavity; 12, groove; 121, inclined side wall; 1211, first position part of side wall; 1212, second position part of side wall; 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 face; 31, oil tank; 32, hydraulic power element; 33, three-position four-way directional valve; 331, one-way port; 332, two-way port; 333, three-way port; 334, four-way port; 34, first pipeline; 35, second pipeline; 4, separation bearing. DETAILED DESCRIPTION

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

[0034] In the description of the present application, it should be understood that the terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0035] The Z-axis in the drawings represents the vertical direction, i.e. the up-down position, and the positive direction of the Z-axis represents the upper side, and the negative direction of the Z-axis represents the lower side; the Y-axis in the drawings represents the left-right position, and the positive direction of the Y-axis represents the left side, and the negative direction of the Y-axis represents the right side; the X-axis in the drawings represents the longitudinal direction, i.e. the front-rear position, and the positive direction of the X-axis represents the front side, and the negative direction of the X-axis represents the rear side. It should be noted that the meanings of the aforementioned Z-axis, Y-axis and X-axis are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0036] The term "include," and derivations thereof, is an open term that means "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 additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optional" means "optional in at least one embodiment". Related definitions are given throughout the description. It is to be noted that the terms "first", "second", and the like, used in the description and in the claims, are used to differentiate between different apparatuses, modules, or units, and do not imply a sequence or order of performing the functions of these apparatuses, modules, or units.

[0037] It is to be noted that the terms "one", "multiple", mentioned in the present application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, it should be understood as "one or more".

[0038] Referring to Figures 1-4 An application of a piston applied to a hydraulic system in an embodiment of the present application, comprising a piston shell 1 and a piston structure 2, wherein a piston cavity 11 is arranged in the piston shell 1, and the piston structure 2 is movably fitted in the piston cavity 11.

[0039] An inner wall of the piston cavity 11 is provided with a groove 12, wherein a side wall of the groove 12 comprises a side wall first position part 1211 and a side wall second position part 1212 which are towards the same side wall, the side wall first position part 1211 and the side wall second position part 1212 are at different axial positions of the piston shell 1, and the side wall first position part 1211 and the side wall second position part 1212 are at different circumferential positions of the piston shell 1.

[0040] The piston structure 2 comprises a piston body 21 and a lock block 22, wherein the lock block 22 is connected to an outer circumferential surface of the piston body 21 and is located in the groove 12, and the lock block 22 is used to abut against the side wall first position part 1211 or the side wall second position part 1212 along the axial direction of the piston body 21.

[0041] The piston provided by the embodiment is applied to a hydraulic system, the piston structure 2 is movably fitted in the piston cavity 11 of the piston shell 1, that is, the piston structure 2 can move in any direction (except radial movement) relative to the piston cavity 11. In addition, the side wall of the piston cavity 11 is provided with a groove 12, and the locking block 22 of the piston structure 2 is located in the groove 12, so that the locking block 22 can only move in the groove 12. In addition, the side wall of the groove 12 comprises a side wall first position part 1211 and a side wall second position part 1212 which are arranged towards the same side wall, and the locking block 22 is arranged to abut against the side wall first position part 1211 or the side wall second position part 1212 along the axial direction of the piston body 21, that is, the side wall first position part 1211 and the side wall second position part 1212 are arranged towards the axial direction of the piston body 21 and are arranged towards the same end of the axial direction. In addition, the side wall first position part 1211 and the side wall second position part 1212 are not only located at different positions in the circumferential direction of the piston shell 1, but also are located at different positions in the axial direction of the piston shell 1. Thus, when the locking block 22 abuts against the side wall first position part 1211 in the axial direction of the piston shell 1, the piston structure 2 can be located at a first position relative to the piston shell 1 (the piston structure 2 at this position is located at a first axial position and a first circumferential position relative to the piston shell 1, as shown in Figure 2 When it is necessary to change the axial position of the piston structure 2, the piston structure 2 can be axially moved to a target axial position (a second axial position, as shown in Figure 3 for example) by an axial hydraulic thrust, and then the locking block 22 at the second axial position is separated from the side wall first position part 1211 of the groove 12. Then, the locking block 22 at the second axial position can be circumferentially rotated to a second circumferential position by a circumferential hydraulic thrust or a mechanical rotating structure, so as to abut against the side wall second position part 1212 of the groove 12 (as shown in Figure 4 ), so as to realize that the piston structure 2 is located at a second position relative to the piston shell 1.

[0042] In the embodiment, when the piston structure 2 is located at the second position, the piston structure 2 is located at both a second axial position relative to the piston shell 1 and a second circumferential position relative to the piston shell 1. At this time, the axial hydraulic thrust can be removed to realize energy saving (the circumferential hydraulic thrust can also be removed at the same time). After the hydraulic thrust is removed, the piston structure 2 cannot be reset to the first position along the axial direction due to the limitation of the side wall second position part 1212 on the locking block 22. Alternatively, after the piston structure 2 is located at the second position, the piston structure 2 cannot be reset to the first position along the axial direction even if hydraulic leakage occurs, but is kept at the second position. Thus, the robustness of the hydraulic system is better.

[0043] It should be noted that the side wall of the groove 12 includes a side wall first position part 1211 and a side wall second position part 1212 which are towards the same side wall, where "towards the same side wall" means that the side wall first position part 1211 and the side wall second position part 1212 are located on the wall of the same side of the groove. For example Figure 5 As shown, the groove 12 along the one side wall (front side wall) of the piston housing 1 in the axial direction includes two parts which are perpendicular to the axial direction of the piston housing 1, i.e., the side wall first position part 1211 and the side wall second position part 1212 respectively; at this time, the extending directions of the side wall first position part 1211 and the side wall second position part 1212 can be parallel, and the directions of the side wall first position part 1211 and the side wall second position part 1212 are both towards the other side wall (rear side wall) of the piston housing 1 in the axial direction, i.e., the directions of the side wall first position part 1211 and the side wall second position part 1212 are both towards the negative direction of the X axis. For another example Figures 1-4 As shown, the extending directions of the side wall first position part 1211 and the side wall second position part 1212 are not only parallel, but also the same, i.e., the side wall first position part 1211 and the side wall second position part 1212 are connected and constitute an inclined side wall 121.

[0044] Optionally, the piston applied to the hydraulic system further includes a reset spring (not shown in the figure), which is used to give the piston structure 2 an axial retaining force to keep the lock block 22 in the state of abutting against the side wall first position part 1211 or the side wall second position part 1212.

[0045] In this embodiment, the reset spring always gives the piston structure 2 a force towards the positive direction of the X axis, i.e., the reset spring always gives the lock block 22 a force to move towards the front side wall of the groove 12, so as to ensure that the lock block 22 is kept in the state of abutting against the side wall first position part 1211 or the side wall second position part 1212, thereby preventing the lock block 22 from moving by mistake. Wherein, the reset spring can be installed in the piston cavity 11, one end of which is connected with the side wall of the piston cavity 11 away from the piston structure 2, and the other end is connected with the piston structure 2 (specifically with the piston body), and the reset spring at this position is always in a stretched state, and is used to give the piston structure 2 a force to move in the axial direction towards the first axial position.

[0046] Of course, even without the reset spring, the piston structure 2 can also be locked in the second position under the action of the friction of the side wall second position portion 1212, and will not be reset to the first position along the axial direction. The reset 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 also includes a spring for clutch reset inside, even without the reset spring of the present embodiment, the spring for clutch reset inside the clutch can also make the position locking of the piston structure 2 more stable and reliable.

[0047] Specifically, when the lock block 22 abuts against the side wall first position portion 1211 (i.e., when the lock block 22 is in the first position, as shown in Figure 2 ), under the action of the reset spring, the elastic force of the reset spring can 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 moved to the second axial position (as shown in Figure 3 ) by the axial hydraulic thrust in the negative direction of the X axis, and then the lock block 22 in the second axial position can be rotated to the second circumferential position by, for example, a circumferential hydraulic thrust or a mechanical rotating structure, so as to abut against the side wall second position portion 1212 of the groove 12 (as shown in Figure 4 ), and under the elastic force of the reset spring, the lock block 22 can be kept in the state of abutting against the side wall second position portion 1212, i.e., the lock block 22 can be kept in the state of abutting against the second position. Thereafter, the axial hydraulic thrust and the circumferential hydraulic thrust can be removed to achieve energy saving and consumption reduction.

[0048] Optionally, referring to Figures 1-5 , the two side walls of the groove 12 spaced apart in the circumferential direction of the piston housing 1 are a first end wall 122 and a second end wall 123, wherein the side wall first position portion 1211 and the side wall second position portion 1212 are located between the first end wall 122 and the second end wall 123; the first flow channel 13 and the 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 outer liquid port on the surface of the piston housing 1, the other end of the first flow channel 13 forms a first inner liquid port at the first end wall 122, one end of the second flow channel 14 forms a second outer liquid port on the surface of the piston housing 1, and the other end of the second flow channel forms a second inner 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 a first end wall 122 and a second end wall 123, while the aforementioned sidewall first position portion 1211 and sidewall second position portion 1212 are located between the first end portion and the second end wall 123. On this basis, a first flow channel 13 and a second flow channel 14 are respectively provided in the side wall of the piston housing 1. One end of the first flow channel 13 forms a first external liquid inlet on the surface of the piston housing 1, for example, forming a first external liquid inlet on the front end surface of the piston housing 1. The other end of the first flow channel 13 forms a first internal liquid inlet on the first end wall 122. One end of the second flow channel 14 forms a second external liquid inlet on the surface of the piston housing 1, for example, forming a second external liquid inlet on the front end surface of the piston housing 1. The other end of the second oil channel forms a second internal liquid inlet on 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 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 inner 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, and finally the piston structure 2 is moved to the second position.

[0051] When the piston structure 2 needs to be moved from the second position to the first position, the piston structure 2 can be maintained 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 FIG. 1 (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 4When the second position is shown, after the circumferential rotation liquid medium is sprayed from the second inner liquid port, the second side of the lock block 22 is the force receiving surface of the rotation hydraulic pressure, so the lock block 22 rotates towards the direction of the first inner liquid port until it is in the Figure 3 The position is shown, at this time, the axial hydraulic thrust can be removed (of course, the circumferential rotation hydraulic pressure can also be removed at the same time), under the action of the reset spring, the lock block 22 is 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 to enter the recess 12 through the first flow channel 13 and recovers the liquid medium flowing out of the recess 12 through the second flow channel 14; when the system is in the second working state, the hydraulic system drives the liquid medium to enter the recess 12 through the second flow channel 14 and recovers the liquid medium flowing out of the recess 12 through the first flow channel 13.

[0054] In this embodiment, the circumferential hydraulic thrust for rotating the lock block 22 is provided by the hydraulic system, the piston, or the hydraulic system has at least two working states, that is, 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 drives the liquid medium to enter the recess 12 through the first flow channel 13 and flow out of the recess 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 drives the liquid medium to enter the recess 12 through the second flow channel 14 and flow out of the recess 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 circumferential rotation of the lock block 22. The liquid medium can be hydraulic oil.

[0055] Referring to Figure 6 Since the piston is applied to the hydraulic system, another embodiment of the present application further provides a hydraulic system, which comprises the aforementioned piston and an oil tank 31, a hydraulic power element 32 and a three-position four-way reversing valve 33, the input end of the hydraulic power element 32 is connected with the oil tank 31, the output end of the hydraulic power element 32 is connected with a port 331 of the three-position four-way reversing valve 33, a port 332 of the three-position four-way reversing valve 33 is connected with the first outer liquid port, a port 333 of the three-position four-way reversing valve 33 is connected with the oil tank 31, and a port 334 of the three-position four-way reversing valve 33 is connected with the second outer liquid port.

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

[0057] In the embodiment, when it is needed to move the piston structure 2 from the first position to the second position, the piston structure 2 can be first axially moved to the second axial position (as shown in Figure 3 ) in the negative direction of the X axis through the axial hydraulic thrust; then the piston or the hydraulic system can be in the first working state, i.e. the three-position four-way reversing valve 33 is in the left position in Figure 6 , at this time, the one port 331 is in communication with the two-way port 332, and the four-way port 334 is in communication with the three-way port 333, then through the hydraulic power member 32, for example through the oil pump to supply oil, the hydraulic oil will sequentially pass through the one port 331, the two-way port 332, the first outer liquid port and the first inner liquid port into the recess 12, and then sequentially pass through the second inner liquid port, the second outer liquid port, the four-way port 334 and the three-way port 333 back to the oil tank 31, in the process of the hydraulic oil flowing, the locking block 22 is pushed and rotated from the position shown in Figure 3 to the second position shown in Figure 4 .

[0058] When it is needed to move the piston structure 2 from the second position to the first position, the piston or the hydraulic system can be in the second working state, i.e. the three-position four-way reversing valve 33 is in the right position in Figure 6 , at this time, the one port 331 is in communication with the four-way port 334, and the two-way port 332 is in communication with the three-way port 333, then through the oil pump to supply oil, the hydraulic oil will sequentially pass through the one port 331, the four-way port 334, the second outer liquid port and the second inner liquid port into the recess 12, and then sequentially pass through the first inner liquid port, the first outer liquid port, the two-way port 332 and the three-way port 333 back to the oil tank 31, in the process of the hydraulic oil flowing, the locking block 22 is pushed and rotated from the position shown in Figure 4 to the position shown in Figure 3 .

[0059] It should be noted that when the lock block 22 needs to rotate circumferentially, the axial hydraulic thrust can be used to keep the lock block 22 in the second axial position, so that the lock block 22 will not move axially due to the influence of the reset spring when it rotates circumferentially; when the lock block 22 needs to rotate circumferentially to the second circumferential position required (also indicating that the lock block 22 is in the second axial position), the axial hydraulic thrust can be removed; it can be understood that during the process of resetting the lock block 22 from the second position to the first position by the piston structure 2, when the lock block 22 is rotated from the position shown in Figure 4 to the position shown in Figure 3 , the axial hydraulic thrust is also removed, and then the lock block 22 is reset to the first position shown in Figure 2 under the action of the reset spring.

[0060] It can be understood that the three-position four-way directional 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. When the three-position four-way directional valve 33 is in the middle position (as shown in Figure 6 , the three-position four-way directional valve 33 is in the middle position), the 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 directional valve 33 in the middle position.

[0061] Among them, the three-position four-way directional valve 33 can be an electromagnetic directional valve, which is convenient for adjusting its working position to be the left position or the right position or the middle position. The hydraulic power component 32 can be an oil pump, and can also be an accumulator or other components with the function of generating or storing hydraulic energy. As shown in Figure 6 , the two-way port 332 of the three-position four-way directional valve 33 can be connected with the first outer hydraulic port of the first flow channel 13 through the first pipeline 34, and the four-way port 334 can be connected with the second outer hydraulic 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 lock block 22 is directly stressed, and when the piston structure 2 moves axially, the piston body 21 is directly stressed.

[0063] Optionally, as shown in Figures 1-4 , in the 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 arranged at an acute angle with the setting plane; the side wall of the lock 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.

[0064] In this embodiment, it is preferred that, as shown in Figures 1-4As shown, the extending directions of the side wall first position part 1211 and the side wall second position part 1212 are parallel and are located on the same plane, that is, the side wall first position part 1211 and the side wall second position part 1212 are connected and form an inclined side wall 121, and the plane of the inclined side wall 121 is arranged at an acute angle with the setting plane.

[0065] Moreover, since the inclined side surface 221 is parallel to the inclined side wall 121 of the lock block 22, when the lock block 22 is rotated from the position shown in Figure 3 to the second position shown in Figure 4 , the inclined side surface 221 of the lock block 22 is not in contact with the inclined side wall 121, and when the inclined side surface 221 of the lock block 22 is rotated to be in contact with the inclined side wall 121 of the groove 12, the purpose of moving the lock block 22 to the second position is achieved. Similarly, when the lock block 22 is rotated from the second position shown in Figure 4 to the position shown in Figure 3 , at the moment when the lock block 22 is rotated, the inclined side surface 221 of the lock block 22 is separated from the inclined side wall 121, so as not to be in contact. 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 be in contact with the inclined side wall 121, which can reduce the friction loss between the lock block 22 and the piston shell 1, and can reduce the size of the circumferential rotation hydraulic pressure required when the lock block 22 rotates circumferentially.

[0066] Moreover, since the inclined side surface 221 is parallel to the inclined side wall 121, it is ensured that the inclined side surface 221 of the lock block 22 can be in contact with the inclined side wall 121 when the lock block 22 is in the first position or in the second position, so as to ensure that the force area between them is sufficient, and the stability of the lock block 22 in the first position or the second position can be ensured.

[0067] Optionally, referring to Figure 7 , in the piston, the angle between the inclined side wall 121 and the setting plane 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 plane is α, that is, the angle between the inclined side wall 121 and the axial direction of the piston shell 1 is 90°-α, and (90°-α) is denoted as θ. Here, the relationship between μ and α is μ≥cot(90°-α), which is equivalent to μ≥cotθ, so as to ensure that the static friction force between the inclined side surface 221 of the lock block 22 and the inclined side wall 121 of the groove 12 can ensure that the lock block 22 is locked in the second position. The analysis is as follows: when the lock block 22 is in the second position, as shown in Figure 7 , the axial hydraulic pressure can be removed (that is, F 轴is equal to the elastic force F of the return spring 弹 For example, the direction is the axial direction of the piston housing 1, and thus F 弹 will form two components, one is F 旋 extending along the inclined side wall 121, and the other is normal pressure N = F 弹 sin θ, where N x μ = f (i.e. static friction), and F 旋 = F 弹 cos θ, N = F 弹 sin θ, and thus f = F 弹 sin θ x μ; to make the locking block 22 self-locked in the second position by the elastic force of the return spring, it is required that f ≥ F 旋 , and thus it is required that μ ≥ cot θ.

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

[0070] In the embodiment, since the piston is connected with the clutch to drive the clutch to engage or disengage, the piston structure 2 can be connected with the clutch through the release bearing 4, and thus it is ensured that the piston structure 2 only transmits axial force to the clutch, and the rotational movement of the piston structure 2 will not be limited 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 not only involves axial movement, but also involves circumferential rotational movement, and thus the piston structure 2 is connected with the outer ring of the release bearing 4, and the clutch can be connected with the inner ring of the release bearing 4, so that when the piston structure 2 changes the position in the axial direction, the clutch will make corresponding action, and when the piston structure 2 rotates circumferentially, the piston structure 2 rotates together with the outer ring of the release bearing 4, but the inner ring of the release bearing 4 and the clutch can not rotate.

[0071] Another embodiment of the present application further provides a piston control method applied to a hydraulic system, based on the piston applied to the hydraulic system as described above, as shown in Figure 8 , the method comprises:

[0072] When the piston structure 2 needs to move from the first position to the second position, the piston structure 2 in 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 part 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 in 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 lock block 22 axially abuts against the first position portion 1211 of the side wall.

[0074] 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 again.

[0075] Another embodiment of the present application further 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 again.

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

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

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 fitted in the piston cavity (11); 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 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) or the second position portion (1212) of the side wall along the axial direction of the piston body (21); 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 flow channel (14) forms a second internal liquid port at the second end wall (123).

2. The piston for use in a hydraulic system according to claim 1, characterized in that: It also includes a return spring, which is used to give the piston structure (2) an axial retaining force so that the locking block (22) is kept 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 for use in a hydraulic system according to claim 1, characterized in that: The invention 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).

4. 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 surface, 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 to the setting surface; 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).

5. The piston for use in a hydraulic system according to claim 4, characterized in that: The angle between the inclined side wall (121) and the setting surface is α, the static friction coefficient between the inclined side wall (121) and the inclined side wall (121) is μ, .

6. A hydraulic system, characterized in that: The hydraulic system comprises a piston as claimed in any one of claims 1 to 5, 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 third port (333) of the three-position four-way reversing valve (33) is connected to the oil tank (31), and a fourth 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 in communication with the second port (332), and the fourth port (334) of the three-position four-way reversing valve (33) is in communication with 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 in communication with the fourth port (334), and the second port (332) of the three-position four-way reversing valve (33) is in communication with the third port (333).

7. The hydraulic system according to claim 6, characterized in that The invention also comprises 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.

8. A piston control method for a hydraulic system, based on the piston for a hydraulic system according to any one of claims 1 to 5, 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) axially abuts 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.

9. A vehicle, characterized in that: The invention comprises a piston applied to a hydraulic system according to any one of claims 1 to 5, or comprises a hydraulic system according to any one of claims 6 to 7.

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