Hydraulic oil cylinder

Abstract

The hydraulic oil cylinder comprises a cylinder barrel, the cylinder barrel comprises a first cylinder barrel part, a middle connecting barrel part and a second cylinder barrel part which are sequentially distributed in the axial direction, and the interiors of the first cylinder barrel part, the second cylinder barrel part and the middle connecting barrel part jointly form a mounting space; part of the piston assembly extends into the mounting space and can move in the length direction of the mounting space, and a containing cavity is formed in the piston assembly; the locking ball is arranged in the accommodating cavity; the floating piston assembly is arranged in the mounting space and can be matched with the piston assembly to push part of the locking balls into the locking grooves; wherein the locking groove is jointly formed by the inner side wall of the middle connecting cylinder part and the inner side wall of the second cylinder barrel part and can be communicated with the containing cavity, the hardness range of the middle connecting cylinder part and / or the hardness range of the second cylinder barrel part is 20 HRC to 70 HRC, and the hydraulic oil cylinder has the advantages of being long in service life and good in operation stability and reliability.

Description

Technical Field

[0001] The present application belongs to the technical field of mechanical equipment, and specifically relates to a hydraulic cylinder. Background Art

[0002] As one of the main actuators of the hydraulic system, the hydraulic cylinder is widely used in various fields. Generally, after the hydraulic cylinder is in place, it needs to withstand the thrust or pull of the external load, and needs to be locked under this working condition without displacement. In the existing cylinder locking technology, in order to keep the cylinder piston rod from displacement, a locking steel ball is used to lock the piston rod and the cylinder barrel. After the above-mentioned hydraulic cylinder is used too many times, the locking steel ball will scratch the groove wall of the locking groove during the process of frequently entering and exiting the locking groove, which will shorten the service life of the hydraulic cylinder and affect the stability and reliability of the hydraulic cylinder operation. Utility Model Content

[0003] The purpose of the present application is to provide a hydraulic cylinder having the advantages of long service life, good operating stability and reliability.

[0004] In order to achieve the above object, the present application provides a hydraulic cylinder, which includes:

[0005] The cylinder comprises a first cylinder portion, an intermediate connecting cylinder portion and a second cylinder portion which are sequentially distributed along the axial direction, wherein the first cylinder portion, the second cylinder portion and the intermediate connecting cylinder portion together form an installation space;

[0006] A piston assembly, part of which extends into the installation space and can move along the length direction of the installation space, and an accommodating cavity is formed on the piston assembly;

[0007] A locking ball is arranged in the accommodating cavity;

[0008] A floating piston assembly is disposed in the installation space and can cooperate with the piston assembly to push a portion of the locking ball into the locking groove;

[0009] Among them, the locking groove is formed by the inner side wall of the middle connecting barrel and the inner side wall of the second cylinder barrel and can be connected with the accommodating cavity. The hardness range of the middle connecting barrel and / or the hardness range of the second cylinder barrel is 20HRC-70HRC.

[0010] In the embodiment of the present application, the intermediate connecting cylinder is a quenched part.

[0011] In an embodiment of the present application, the cylinder further comprises a flange portion sleeved on the outer peripheral side of the middle connecting cylinder portion, one end of the flange portion is welded to the first cylinder portion, and the other end of the flange portion is welded to the second cylinder portion.

[0012] In an embodiment of the present application, the cylinder further comprises a flange portion sleeved on the outer peripheral side of the middle connecting cylinder portion, the first cylinder portion and the flange portion are detachably connected, and the second cylinder portion and the flange portion are detachably connected.

[0013] In an embodiment of the present application, the hydraulic cylinder further comprises:

[0014] A first sealing member, used for sealing a gap between the first cylinder portion and the flange portion;

[0015] The second sealing member is used to seal the gap between the second cylinder portion and the flange portion.

[0016] In an embodiment of the present application, a locking portion is formed on the floating piston assembly, and part of the locking ball can be pushed into the locking groove by the locking portion when the locking portion is laterally inserted into the accommodating cavity.

[0017] In an embodiment of the present application, the floating piston assembly comprises:

[0018] a floating piston shaft disposed in the installation space and connected to the second cylinder portion;

[0019] The floating piston is sleeved on the outer peripheral side of the floating piston shaft in an axially movable manner. The locking portion is formed on the floating piston and at one end of the floating piston close to the piston assembly.

[0020] In an embodiment of the present application, the floating piston further comprises a mounting portion movably sleeved on the floating piston shaft, and the locking portion is arranged at one end of the mounting portion close to the piston assembly and is detachably connected to the mounting portion.

[0021] In an embodiment of the present application, the piston assembly comprises:

[0022] A piston rod, part of which extends into the installation space and is movable along the length direction of the installation space;

[0023] The piston includes a locking section that can abut against the floating piston shaft and a connecting section connected to the piston rod. The locking section is arranged on a side of the connecting section away from the piston rod and includes a middle part and an outer ring part located on the outer peripheral side of the middle part. An insertion groove for lateral insertion of the lock head is formed between the middle part and the outer ring part. A radially penetrating locking ball limiting hole is formed on the outer ring part. The locking ball limiting hole and part of the insertion groove together form a accommodating cavity.

[0024] In an embodiment of the present application, the locking section also includes a connecting portion, the connecting section is arranged at a first end of the connecting portion, the middle portion and the outer ring portion are both arranged at a second end of the connecting portion, and the outer ring portion is detachably connected to the connecting portion.

[0025] It can be known from the above technical scheme that the hydraulic cylinder includes a cylinder, a piston assembly, a floating piston assembly and a locking ball. The cylinder includes a first cylinder portion, an intermediate connecting cylinder portion and a second cylinder portion which are sequentially distributed along the axial direction. The first cylinder portion, the second cylinder portion and the intermediate connecting cylinder portion together form an installation space; a portion of the piston assembly extends into the installation space and can move along the length direction of the installation space, and an accommodating cavity is formed on the piston assembly; the locking ball is arranged in the accommodating cavity; the floating piston assembly is arranged in the installation space and can cooperate with the piston assembly to push a portion of the locking ball into the locking groove; wherein the locking groove is formed by the intermediate connecting cylinder portion. The inner side wall and the inner side wall of the second cylinder portion are formed together and can be connected with the accommodating cavity. The hardness range of the intermediate connecting cylinder portion and / or the hardness range of the second cylinder portion is 20HRC-70HRC. The above-mentioned arrangement enables the intermediate connecting cylinder portion and / or the second cylinder portion to have sufficient hardness, that is, the position where the locking groove on the cylinder barrel is located has sufficient hardness. As the use time of the hydraulic cylinder continues to increase, some locking balls frequently enter or exit the locking groove and continuously contact the groove wall of the locking groove. The groove wall of the locking groove will not be scratched by the locking balls, which is beneficial to extending the service life of the hydraulic cylinder and allowing the hydraulic cylinder to operate stably and reliably.

[0026] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. In the drawings:

[0028] Figure 1 It is a cross-sectional schematic diagram of the hydraulic cylinder in the embodiment of the utility model (unlocked state);

[0029] Figure 2 It is a cross-sectional schematic diagram of the hydraulic cylinder in the embodiment of the utility model (mechanical self-locking state);

[0030] Figure 3 for Figure 2 A partial schematic diagram of .

[0031] Description of Reference Numerals

[0032] 1 Cylinder 101 First oil port

[0033] 102 Second oil port 103 Locking groove

[0034] 104 first cylinder part 105 middle connecting cylinder part

[0035] 106 Second cylinder portion 107 Flange portion

[0036] 2 Piston assembly 201 Accommodating chamber

[0037] 202 Piston rod 203 Piston

[0038] 204 locking section 205 connecting section

[0039] 206 middle part 207 outer ring part

[0040] 208 Insertion slot 209 Locking ball stop hole

[0041] 210 Head 3 with rod cavity

[0042] 4 Floating piston assembly 401 Lock head

[0043] 402 floating piston shaft 403 floating piston

[0044] 404 mounting portion 405 mounting seat

[0045] 406 elastic member installation cavity 407 elastic member

[0046] 408 Guide arc surface 5 Rodless cavity

[0047] 6 Locking ball 7 Stopper

[0048] 8 Support assembly 801 first support ring

[0049] 802 second support ring 9 third sealing element

[0050] 10 Fourth sealing member 11 Anti-lock sleeve

[0051] 12 Cylinder head 13 Guide sleeve DETAILED DESCRIPTION

[0052] The specific implementation of the present application is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present application, and is not used to limit the present application.

[0053] In an embodiment of the present application, a hydraulic cylinder is provided, such as Figure 1-3 As shown, the hydraulic cylinder includes:

[0054] The cylinder 1 comprises a first cylinder portion 104, an intermediate connecting cylinder portion 105 and a second cylinder portion 106 which are sequentially distributed along the axial direction, wherein the first cylinder portion 104, the second cylinder portion 106 and the intermediate connecting cylinder portion 105 together form an installation space;

[0055] A piston assembly 2, part of which extends into the installation space and can move along the length direction of the installation space, and an accommodating cavity 201 is formed on the piston assembly 2;

[0056] The locking ball 6 is arranged in the accommodating cavity 201;

[0057] A floating piston assembly 4 is disposed in the installation space and can cooperate with the piston assembly 2 to push a portion of the locking ball 6 into the locking groove 103;

[0058] Among them, the locking groove 103 is formed by the inner wall of the intermediate connecting cylinder 105 and the inner wall of the second cylinder part 106 and can be connected with the accommodating cavity 201. The hardness range of the intermediate connecting cylinder 105 and / or the hardness range of the second cylinder part 106 is 20HRC-70HRC.

[0059] Specifically, a first oil port 101 and a second oil port 102 are formed on the first cylinder portion 104. The hydraulic cylinder also includes a guide sleeve 13 and a guide sleeve fastening screw. The guide sleeve 13 is arranged at the first end of the installation space and forms a threaded connection with the first cylinder portion 104; the threaded end of the guide sleeve fastening screw passes through the peripheral wall of the first cylinder portion 104 and is threadedly connected to the guide sleeve 13, so as to strengthen the tightness of the connection between the first cylinder portion 104 and the guide sleeve 13. Part of the piston assembly 2 passes through the guide sleeve 13 and extends into the interior of the installation space, and a rod chamber 3 connected to the first oil port 101 is formed between the guide sleeve 13, the piston assembly 2 and the cylinder 1, and a rodless chamber 5 connected to the second oil port 102 is formed between the floating piston assembly 4, the piston assembly 2 and the cylinder 1; the locking ball 6 in this embodiment is a steel ball, and the accommodating chamber 201 is formed with a lateral opening on the side close to the cylinder 1, and part of the locking ball 6 can enter the locking groove 103 (the cross-section of the locking groove 103 in this embodiment is trapezoidal) through the lateral opening.

[0060] When the hydraulic cylinder is required to realize the mechanical self-locking function, hydraulic oil is input into the rod chamber 3 through the first oil port 101 (if there is hydraulic oil in the rodless chamber 5, the hydraulic oil can be discharged outward through the second oil port 102 at this time). Under the action of the hydraulic oil, the piston assembly 2 drives the locking ball 6 to move in the direction of the floating piston assembly 4. In the process of the piston assembly 2 gradually approaching the floating piston assembly 4, the accommodating chamber 201 gradually aligns with the locking groove 103. When the accommodating chamber 201 is completely aligned with the locking groove 103, the two are connected, and the floating piston assembly 4 cooperates with the piston assembly 2 to push part of the locking ball 6 into the locking groove 103. At this time, the locking ball 6 is restricted in the locking groove 103 and cannot move. The piston assembly 2 and the cylinder 1 are locked together by the locking ball 6, and the hydraulic cylinder is in a mechanical self-locking state.

[0061] When it is necessary to release the mechanical self-locking state of the hydraulic cylinder, hydraulic oil is input into the rodless chamber 5 through the second oil port 102, and the hydraulic oil in the rodless chamber 5 pushes the side end surface on the floating piston assembly 4 to separate the floating piston assembly 4 from the piston assembly 2. When the floating piston assembly 4 is completely separated from the piston assembly 2, part of the locking ball 6 withdraws from the locking groove 103. At this time, the piston assembly 2 and the locking ball 6 can move relative to the cylinder 1. The piston assembly 2 moves in the direction away from the floating piston assembly 4 under the action of the hydraulic oil in the rodless chamber 5 (at this time, the hydraulic oil in the rod chamber 3 can be discharged outward through the first oil port 101). At this point, the hydraulic cylinder releases the mechanical self-locking state.

[0062] In this embodiment, the hardness range of the intermediate connecting barrel portion 105 and / or the hardness range of the second cylinder portion 106 is 20HRC-70HRC. Furthermore, in this embodiment, the hardness range of the intermediate connecting barrel portion 105 and / or the hardness range of the second cylinder portion 106 is preferably 55HRC-60HRC. Therefore, the intermediate connecting barrel portion 105 and / or the second cylinder portion 106 have sufficient hardness, that is, the position where the locking groove 103 on the cylinder 1 is located has sufficient hardness. As the use time of the hydraulic cylinder continues to increase, part of the locking ball 6 frequently enters or exits the locking groove 103 and continuously contacts the groove wall of the locking groove 103. The groove wall of the locking groove 103 will not be scratched by the locking ball 6, which is beneficial to extending the service life of the hydraulic cylinder and allowing the hydraulic cylinder to operate stably and reliably.

[0063] In one embodiment of the present application, the intermediate connecting cylinder 105 is a quenched part. Specifically, the intermediate connecting cylinder 105 is made of 45# steel and its hardness range is preferably 55HRC-60HRC. When the locking ball 6 enters or exits the locking groove 103, the locking ball 6 will contact the groove wall of the locking groove 103 on the intermediate connecting cylinder 105 more. Therefore, after the intermediate connecting cylinder 105 is quenched, its hardness can reach the above hardness range, thereby effectively preventing the locking ball 6 from scratching the groove wall of the locking groove 103 during the locking or self-locking process of the hydraulic cylinder. Further, the ratio of the hardness of the locking ball 6 to the hardness of the intermediate connecting cylinder 105 is within a preset range (such as 1 to 1.5).

[0064] In one embodiment of the present application, the cylinder 1 further includes a flange portion 107 sleeved on the outer peripheral side of the middle connecting cylinder portion 105 , one end of the flange portion 107 is welded to the first cylinder portion 104 , and the other end of the flange portion 107 is welded to the second cylinder portion 106 .

[0065] Specifically, the inner diameter of the flange portion 107 is consistent with the outer diameter of the intermediate connecting cylinder portion 105, and the flange portion 107 and the intermediate connecting cylinder portion 105 are assembled together by interference fit to ensure the connection stability between the flange portion 107 and the intermediate connecting cylinder portion 105; the flange portion 107 is welded to the first cylinder portion 104 and the second cylinder portion 106. The above connection method is convenient for separate processing of the various components that make up the cylinder 1, and can also make the first cylinder portion 104, the second cylinder portion 106, the flange portion 107 and the intermediate connecting cylinder portion 105 stably connected together, thereby avoiding leakage of hydraulic oil inside the cylinder 1.

[0066] In another embodiment of the present application, the cylinder 1 further includes a flange portion 107 sleeved on the outer peripheral side of the intermediate connecting cylinder portion 105, the first cylinder portion 104 is detachably connected to the flange portion 107, and the second cylinder portion 106 is detachably connected to the flange portion 107. Specifically, a first external thread is formed on the first cylinder portion 104, and a first internal thread matching the first external thread is formed on one end of the flange portion 107 facing the first cylinder portion 104, thereby realizing the detachable connection between the first cylinder portion 104 and the flange portion 107; similarly, a second external thread is formed on the second cylinder portion 106, and a second internal thread matching the second external thread is formed on one end of the flange portion 107 facing the second cylinder portion 106, thereby realizing the detachable connection between the second cylinder portion 106 and the flange portion 107.

[0067] In one embodiment of the present application, the hydraulic cylinder further comprises:

[0068] A first sealing member, used to seal the gap between the first cylinder portion 104 and the flange portion 107;

[0069] The second sealing member is used to seal the gap between the second cylinder portion 106 and the flange portion 107 .

[0070] Specifically, when the first cylinder portion 104 and the flange portion 107 are detachably connected and the second cylinder portion 106 and the flange portion 107 are detachably connected, the first sealing member is a sealing ring arranged between the first cylinder portion 104 and the flange portion 107 to prevent the hydraulic oil from leaking out of the gap between the first cylinder portion 104 and the flange portion 107; similarly, the second sealing member is a sealing ring arranged between the second cylinder portion 106 and the flange portion 107 to prevent the hydraulic oil from leaking out of the gap between the second cylinder portion 106 and the flange portion 107.

[0071] In one embodiment of the present application, a locking portion 401 is formed on the floating piston assembly 4 , and part of the locking ball 6 can be pushed into the locking groove 103 by the locking portion 401 when the locking portion 401 is laterally inserted into the accommodating cavity 201 .

[0072] Specifically, when the hydraulic cylinder is required to realize the mechanical self-locking function, as the piston assembly 2 gradually approaches the floating piston assembly 4, the accommodating chamber 201 gradually aligns with the locking groove 103. At the same time, the locking head 401 can be laterally inserted into the accommodating chamber 201 and apply a radial thrust to the locking ball 6. When the accommodating chamber 201 is completely aligned with the locking groove 103, part of the locking ball 6 is pushed into the locking groove 103. At this time, the locking ball 6 is restricted in the locking groove 103 and cannot move. The piston assembly 2 and the cylinder 1 are locked together by the locking ball 6, and the hydraulic cylinder is in a mechanical self-locking state.

[0073] When it is necessary to release the mechanical self-locking state of the hydraulic cylinder, the hydraulic oil in the rodless chamber 5 pushes the side end surface on the floating piston assembly 4 to move the locking head 401 away from the piston assembly 2. When the locking head 401 completely withdraws from the accommodating chamber 201 under the action of the hydraulic oil, part of the locking ball 6 withdraws from the locking groove 103. At this time, the piston assembly 2 and the locking ball 6 can move relative to the cylinder 1. The piston assembly 2 moves away from the floating piston assembly 4 under the action of the hydraulic oil in the rodless chamber 5 (at this time, the hydraulic oil in the rod chamber 3 can be discharged outward through the first oil port 101). At this point, the hydraulic cylinder releases the mechanical self-locking state.

[0074] In one embodiment of the present application, the floating piston assembly 4 comprises:

[0075] A floating piston shaft 402, disposed in the installation space and connected to the second cylinder portion 106;

[0076] The floating piston 403 is axially movably sleeved on the outer peripheral side of the floating piston shaft 402 , and the locking portion 401 is formed on the floating piston 403 and at one end of the floating piston 403 close to the piston assembly 2 .

[0077] Specifically, the hydraulic cylinder also includes a cylinder head 12 arranged at an end of the second cylinder portion 106 away from the guide sleeve 13, and the floating piston shaft 402 is arranged inside the second cylinder portion 106 and welded to the cylinder head 12, that is, the floating piston shaft 402 is always in a fixed state, and the floating piston 403 can move axially along the floating piston shaft 402 so that the locking head 401 can extend into or out of the accommodating chamber 201, thereby realizing the mechanical self-locking of the hydraulic cylinder or releasing the mechanical self-locking of the hydraulic cylinder.

[0078] In one embodiment of the present application, the floating piston 403 also includes a mounting portion 404 that is movably mounted on the floating piston shaft 402, and the locking portion 401 is arranged at one end of the mounting portion 404 close to the piston assembly 2 and is detachably connected to the mounting portion 404. For example, an external thread is formed at one end of the locking portion 401 close to the mounting portion 404, and an installation cavity for inserting part of the locking portion 401 is formed at one end of the mounting portion 404 close to the locking portion 401, and an internal thread for thread matching with the external thread is formed in the installation cavity. The above-mentioned arrangement can realize the detachable connection between the locking portion 401 and the mounting portion 404, which is convenient for replacing the locking portion 401 after it is worn, which is beneficial to extending the overall service life of the hydraulic cylinder.

[0079] In another embodiment of the present application, the floating piston 403 also includes a mounting portion 404 that is movably mounted on the floating piston shaft 402, and the locking portion 401 is disposed at one end of the mounting portion 404 close to the piston assembly 2 and is integrally formed with the mounting portion 404, which helps to reduce the manufacturing difficulty and production cost of the floating piston 403.

[0080] In one embodiment of the present application, a guide arc surface 408 is formed at one end of the lock portion 401 facing the piston assembly 2. The setting of the guide arc surface 408 not only facilitates the insertion of the lock portion 401 into the accommodating cavity 201, but also facilitates the lock portion 401 to be subjected to more uniform force when in contact with the locking ball 6, thereby better protecting the locking ball 6.

[0081] In one embodiment of the present application, the floating piston assembly 4 further includes a stopper 7 which is disposed on the floating piston shaft 402 and is used to limit the moving distance of the floating piston 403 .

[0082] Specifically, an annular groove is formed on the outer peripheral wall of one end of the floating piston shaft 402 close to the piston assembly 2. The stop member 7 in this embodiment is a stop ring arranged in the annular groove. The stop ring limits the distance that the floating piston 403 moves toward the direction of the piston assembly 2, thereby preventing the floating piston 403 from detaching from the floating piston shaft 402.

[0083] In one embodiment of the present application, the floating piston assembly 4 further includes:

[0084] The mounting seat 405 is arranged at one end of the cylinder 1 away from the piston assembly 2 and sleeved on the floating piston shaft 402. An elastic member mounting cavity 406 is formed between the floating piston 403, the mounting seat 405 and the floating piston shaft 402;

[0085] The elastic member 407 is disposed in the elastic member installation cavity 406 , one end of the elastic member 407 abuts against the side end surface of the floating piston 403 , and the other end of the elastic member 407 abuts against the side end surface of the installation seat 405 .

[0086] Specifically, the floating piston shaft 402, the mounting seat 405 and the cylinder head 12 are welded together, the elastic member mounting cavity 406 is an annular mounting cavity, the elastic member 407 in this embodiment can be selected as a spring, and the floating piston 403 also includes a mounting portion 404 which is movably mounted on the floating piston shaft 402 and is distributed in a stepped manner, the mounting portion 404 includes a first annular segment and a second annular segment, the axial ends of the first annular segment are respectively connected to the locking portion 401 and the second annular segment, the spring is arranged in the elastic member mounting cavity 406 and is located on the outer peripheral side of the second annular segment, one end of the spring abuts against the side end face of the first annular segment, and the other end abuts against the side end face of the mounting seat 405. When the hydraulic cylinder is in a mechanical self-locking state, the spring is in a natural state (or a reset state, when the spring is not subjected to force), so that the locking head 401 is always in the accommodating chamber 201 and prevents part of the locking ball 6 from withdrawing from the locking chamber; when the mechanical self-locking state of the hydraulic cylinder is released, the spring can be compressed under the action of the hydraulic oil in the rodless chamber 5, so that the locking head 401 can be completely withdrawn from the accommodating chamber 201.

[0087] In one embodiment of the present application, the hydraulic cylinder also includes a third seal 9 arranged on the floating piston 403 and used to seal the gap between the floating piston 403 and the cylinder barrel 1. In this embodiment, the third seal 9 is a sealing ring arranged on the first annular segment of the floating piston 403, which can prevent the hydraulic oil in the rodless chamber 5 from flowing into the elastic member mounting chamber 406 through the gap between the floating piston 403 and the cylinder barrel 1 and affecting the extension or contraction of the elastic member 407, thereby avoiding the situation where it cannot be unlocked or locked.

[0088] In one embodiment of the present application, the hydraulic cylinder also includes a fourth seal 10 arranged on the floating piston 403 and used to seal the gap between the floating piston 403 and the floating piston shaft 402. In this embodiment, the fourth seal 10 is a sealing ring arranged on the first annular segment of the floating piston 403, which can prevent the hydraulic oil in the rodless chamber 5 from flowing into the elastic member mounting chamber 406 through the gap between the floating piston 403 and the floating piston shaft 402 and affecting the extension or contraction of the elastic member 407, thereby avoiding the situation where it cannot be unlocked or locked.

[0089] In one embodiment of the present application, the piston assembly 2 comprises:

[0090] A piston rod 202, a portion of which extends into the installation space and is movable along the length direction of the installation space;

[0091] The piston 203 includes a locking section 204 that can abut against the floating piston shaft 402 and a connecting section 205 connected to the piston rod 202. The locking section 204 is arranged on the side of the connecting section 205 away from the piston rod 202 and includes a middle portion 206 and an outer ring portion 207 located on the outer peripheral side of the middle portion 206. An insertion groove 208 for lateral insertion of the lock head portion 401 is formed between the middle portion 206 and the outer ring portion 207. A radially penetrating locking ball limiting hole 209 is formed on the outer ring portion 207. The locking ball limiting hole 209 and part of the insertion groove 208 together form a accommodating cavity 201.

[0092] Specifically, the piston assembly 2 also includes a rod head 210 arranged on the piston rod 202, and the end of the piston rod 202 away from the rod head 210 passes through the guide sleeve 13 and extends into the cylinder 1 and can move axially along the cylinder 1; the connecting section 205 is sleeved on the end of the piston rod 202 away from the rod head 210; in this embodiment, the insertion groove 208 and the locking head 401 are both annular, and the sizes of the two are adapted, and the insertion groove 208 is formed with an insertion opening at the end facing the locking head 401, so that the locking head 401 can be inserted into or withdrawn from the insertion groove 208 from the position of the insertion opening; the locking ball limiting hole 209 is formed on the radial outside of the insertion groove 208, and the aperture of the locking ball limiting hole 209 is consistent with the outer diameter of the locking ball 6, so that the locking ball 6 can be placed in the locking ball limiting hole 209 and can limit the locking ball 6 from moving arbitrarily; the middle part 206 can block the locking ball 6 to prevent the locking ball 6 from escaping from the accommodating cavity 201.

[0093] Furthermore, a columnar cavity communicating with the rodless cavity 5 is formed inside the middle portion 206, and a connecting channel communicating with the second oil port 102 and the columnar cavity is formed on the locking segment 204, and the hydraulic oil can enter the rodless cavity 5 through the second oil port 102, the connecting channel and the columnar cavity. In addition, the outer ring portion 207 protrudes laterally from the middle portion 206 on the side facing the floating piston assembly 4. In the mechanical self-locking state of the hydraulic cylinder, the side end surface of the middle portion 206 facing the floating piston assembly 4 abuts against the side end surface of the floating piston shaft 402 facing the piston assembly 2, and the side end surface of the outer ring portion 207 facing the floating piston assembly 4 abuts against the side end surface of the first annular segment facing the piston assembly 2.

[0094] In one embodiment of the present application, the hydraulic cylinder also includes an anti-locking sleeve 11 which is sleeved on the piston rod 202 and located between the rod head 210 and the cylinder barrel 1. During the assembly stage of the hydraulic cylinder, there is no hydraulic oil in the hydraulic cylinder, but when the piston rod 202 needs to be able to freely retract and extend, the anti-locking sleeve 11 can prevent the piston rod 202 from being completely retracted and locked.

[0095] In one embodiment of the present application, the locking segment 204 also includes a connecting portion, the connecting segment 205 is arranged at the first end of the connecting portion, the middle portion 206 and the outer ring portion 207 are both arranged at the second end of the connecting portion, and the outer ring portion 207 is detachably connected to the connecting portion.

[0096] Specifically, the connecting section 205 is connected to the first end of the connecting part, a connecting channel is formed on the connecting part, a locking ball limit hole 209 is also formed on the connecting part and on one side of the connecting channel, and the second end of the connecting part is formed with an annular groove located on the outer peripheral side of the middle part 206 and capable of allowing part of the outer ring part 207 to extend into, an internal thread is formed on the side wall of the annular groove, and an external thread matching the above-mentioned internal thread is formed on the outer side wall of the outer ring part 207 facing the annular groove, thereby realizing a detachable connection between the outer ring part 207 and the connecting part, which is convenient for replacing the outer ring part 207 when it is worn.

[0097] In the description of the present application, it should be understood that 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, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0098] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0100] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A hydraulic cylinder, characterized in that: The hydraulic cylinder comprises: The cylinder (1) comprises a first cylinder portion (104), an intermediate connecting cylinder portion (105) and a second cylinder portion (106) which are sequentially distributed along the axial direction, wherein the first cylinder portion (104), the second cylinder portion (106) and the intermediate connecting cylinder portion (105) together form an installation space inside; A piston assembly (2), wherein a portion of the piston assembly (2) extends into the installation space and is movable along the length direction of the installation space, and an accommodating cavity (201) is formed on the piston assembly (2); A locking ball (6) is arranged in the accommodating cavity (201); A floating piston assembly (4) is arranged in the installation space and can cooperate with the piston assembly (2) to push a portion of the locking ball (6) into the locking groove (103); Wherein, the locking groove (103) is formed by the inner side wall of the intermediate connecting barrel (105) and the inner side wall of the second cylinder barrel (106) and can be connected with the accommodating cavity (201), and the hardness range of the intermediate connecting barrel (105) and / or the hardness range of the second cylinder barrel (106) is 20HRC-70HRC.

2. The hydraulic cylinder according to claim 1, characterized in that: The intermediate connecting cylinder (105) is a quenched part.

3. The hydraulic cylinder according to claim 1, characterized in that: The cylinder (1) further comprises a flange portion (107) sleeved on the outer peripheral side of the intermediate connecting cylinder portion (105), one end of the flange portion (107) being welded to the first cylinder portion (104), and the other end of the flange portion (107) being welded to the second cylinder portion (106).

4. The hydraulic cylinder according to claim 1, characterized in that: The cylinder (1) further comprises a flange portion (107) sleeved on the outer peripheral side of the intermediate connecting cylinder portion (105); the first cylinder portion (104) and the flange portion (107) are detachably connected; and the second cylinder portion (106) and the flange portion (107) are detachably connected.

5. The hydraulic cylinder according to claim 4, characterized in that: The hydraulic cylinder also includes: a first sealing member, used for sealing a gap between the first cylinder portion (104) and the flange portion (107); The second sealing member is used to seal the gap between the second cylinder portion (106) and the flange portion (107).

6. The hydraulic cylinder according to claim 1, characterized in that: A locking portion (401) is formed on the floating piston assembly (4), and part of the locking ball (6) can be pushed into the locking groove (103) by the locking portion (401) when the locking portion (401) is laterally inserted into the accommodating cavity (201).

7. The hydraulic cylinder according to claim 6, characterized in that: The floating piston assembly (4) comprises: A floating piston shaft (402) is disposed in the installation space and connected to the second cylinder portion (106); The floating piston (403) is axially movably sleeved on the outer peripheral side of the floating piston shaft (402), and the locking portion (401) is formed on the floating piston (403) and is located at one end of the floating piston (403) close to the piston assembly (2).

8. The hydraulic cylinder according to claim 7, characterized in that: The floating piston (403) further comprises a mounting portion (404) movably sleeved on the floating piston shaft (402), and the locking portion (401) is arranged at one end of the mounting portion (404) close to the piston assembly (2) and is detachably connected to the mounting portion (404).

9. The hydraulic cylinder according to claim 7, characterized in that: The piston assembly (2) comprises: A piston rod (202), a portion of which extends into the installation space and is movable along the length direction of the installation space; The piston (203) comprises a locking section (204) capable of abutting against the floating piston shaft (402) and a connecting section (205) connected to the piston rod (202); the locking section (204) is arranged on a side of the connecting section (205) away from the piston rod (202) and comprises a middle portion (206) and an outer ring portion (207) located on the outer peripheral side of the middle portion (206); an insertion groove (208) for lateral insertion of the locking portion (401) is formed between the middle portion (206) and the outer ring portion (207); a radially through locking ball limiting hole (209) is formed on the outer ring portion (207); the locking ball limiting hole (209) and part of the insertion groove (208) together form the accommodating cavity (201).

10. The hydraulic cylinder according to claim 9, characterized in that: The locking section (204) further comprises a connecting portion, wherein the connecting section (205) is arranged at a first end of the connecting portion, the middle portion (206) and the outer ring portion (207) are both arranged at a second end of the connecting portion, and the outer ring portion (207) is detachably connected to the connecting portion.

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