Hydraulic cylinder

Abstract

The invention provides a hydraulic cylinder, and belongs to the technical field of hydraulic driving. The hydraulic cylinder comprises a cylinder body, a piston assembly and a pressure control assembly. The piston assembly is movably located in the cylinder body, the piston assembly and the cylinder body define a first sealing cavity, a second sealing cavity and a third sealing cavity, the pressure control assembly is located outside the cylinder body and connected with the cylinder body, the pressure control assembly is communicated with the third sealing cavity, and the first sealing cavity is communicated with the second sealing cavity. The pressure control assembly is configured in the mode that when the piston assembly stretches out and draws back, acting force is applied to the piston assembly through the third sealing cavity when the piston assembly stretches out and draws back, and the acting force is counter-acting force of water pressure borne by the piston assembly when the piston assembly stretches out and draws back. The control precision of the deep sea equipment can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic drive, and in particular relates to a hydraulic cylinder. Background Art

[0002] As human beings continue to explore the deep sea, their requirements for deep sea equipment are becoming increasingly stringent. Deep sea equipment not only needs to operate stably in an environment with high pressure, low temperature and rich corrosive media, but also needs to be able to perform complex actions.

[0003] In the related art, various parts of the deep-sea equipment are connected to piston rods of different hydraulic cylinders. By controlling the extension and contraction of different hydraulic cylinders, the parts of the deep-sea equipment connected to the hydraulic cylinders can be controlled so that the deep-sea equipment performs different actions.

[0004] However, when the hydraulic cylinder is extended and retracted underwater, the piston rod of the hydraulic cylinder will be affected by the seawater pressure. In particular, the water pressure changes caused by the change of seawater depth will seriously affect the actual output power and control accuracy of the hydraulic cylinder, and thus affect the control accuracy of deep-sea equipment. Summary of the invention

[0005] The disclosed embodiment provides a hydraulic cylinder that can automatically adapt to changes in seawater depth. The actual output power and control accuracy of the hydraulic cylinder will not be affected by the seawater depth, thereby improving the control accuracy of deep-sea equipment. The technical solution is as follows:

[0006] The disclosed embodiment provides a hydraulic cylinder, which includes a cylinder body, a piston assembly and a pressure control assembly; the piston assembly is movably located in the cylinder body, and the piston assembly and the cylinder body define a first sealed chamber, a second sealed chamber and a third sealed chamber, and when the pressure in the first sealed chamber is greater than the pressure in the second sealed chamber, the piston assembly moves toward the inside of the cylinder body, and when the pressure in the first sealed chamber is less than the pressure in the second sealed chamber, the piston assembly extends from the cylinder body; the pressure control assembly is located outside the cylinder body and connected to the cylinder body, and the pressure control assembly is connected to the third sealed chamber, and the pressure control assembly is configured to: when the piston assembly is extended or retracted, a force is applied to the piston assembly through the third sealed chamber when the piston assembly is extended or retracted, and the force is a reaction force of the water pressure to which the piston assembly is subjected when it is extended or retracted.

[0007] In another embodiment of the present disclosure, the cylinder body includes an outer cylinder sleeve and an inner center sleeve, the inner center sleeve is located inside the outer cylinder sleeve, and the first end of the inner center sleeve is connected to the first end of the outer cylinder sleeve, and an annulus is formed between the inner center sleeve and the outer cylinder sleeve; the piston assembly includes an outer sleeve and a piston, the outer sleeve is coaxially sleeved outside the piston, and the first end of the outer sleeve is sealingly connected to the piston, the second end of the outer sleeve is movably located in the annulus, and is sealingly connected to the inner wall of the outer cylinder sleeve and the outer wall of the inner center sleeve respectively; the first sealing chamber is defined between the second end of the outer sleeve, the outer wall of the outer sleeve and the inner wall of the outer cylinder sleeve, the second sealing chamber is defined between the inner wall of the outer sleeve, the piston and the inner wall of the inner center sleeve, and the third sealing chamber is defined between the second end of the outer sleeve, the inner wall of the outer cylinder sleeve and the outer wall of the inner center sleeve.

[0008] In yet another implementation of the present disclosure, the end surface area of ​​the second end of the outer sleeve is equal to the sum of the end surface area of ​​the first end of the outer sleeve and the end surface area of ​​the first end of the piston.

[0009] In another implementation of the present disclosure, the outer sleeve includes an outer cylinder and a sealing ring, the sealing ring is sealed outside the first end of the outer cylinder and connected to the outer cylinder, the first end of the outer cylinder is movably located in the annulus, and the second end of the outer cylinder is located outside the cylinder body.

[0010] In another embodiment of the present disclosure, the piston assembly further includes a piston rod, a first end of which is connected to the piston, the piston rod is coaxially located in the outer cylinder, and a second end of the piston rod is movably located in the inner center sleeve; the interior of the piston rod has an installation space for installing a displacement sensor.

[0011] In yet another implementation of the present disclosure, the difference between the cross-sectional area of ​​the piston and the cross-sectional area of ​​the piston rod is equal to the end surface area of ​​the sealing ring platform.

[0012] In another implementation of the present disclosure, the hydraulic cylinder also includes a protective cover, which is located outside the outer cylinder sleeve and connected to one end of the outer cylinder sleeve, a sealed space is formed between the protective cover and the end surface of the outer cylinder sleeve, the sealed space is connected to the installation space, and the displacement sensor is located in the sealed space and the installation space.

[0013] In another embodiment of the present disclosure, the pressure control assembly includes a flexible container filled with oil. The flexible container can be deformed under the action of water pressure and can drive the oil inside into the third sealing chamber after deformation.

[0014] In yet another implementation of the present disclosure, the flexible container is an annular structure, and the flexible container is sleeved outside the cylinder body.

[0015] In another embodiment of the present disclosure, the outer cylinder sleeve includes a cylinder head, a cylinder barrel and a cylinder bottom, the cylinder head is connected to the first end of the cylinder barrel and is sleeved outside the outer sleeve; the cylinder bottom is connected to the second end of the cylinder barrel and is connected to the inner center sleeve.

[0016] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0017] Since the hydraulic cylinder further includes a pressure control component, and the pressure control component is connected to the third sealed chamber, the pressure control component is configured to apply a force to the piston component through the third sealed chamber when the piston component is extended or retracted, and the force is the reaction force of the water pressure on the piston component when it is extended or retracted. In this way, the piston component will not be affected by the water pressure when moving, the output power is stabilized, and the control accuracy of the deep-sea equipment is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a schematic diagram of the appearance structure of a hydraulic cylinder provided in an embodiment of the present disclosure;

[0020] Figure 2 is a schematic diagram of an axial cross-sectional structure of a hydraulic cylinder provided in an embodiment of the present disclosure;

[0021] Figure 3 is a structural schematic diagram of a hydraulic cylinder provided by an embodiment of the present disclosure when the extension displacement is the maximum;

[0022] Figure 4 is a structural schematic diagram of a hydraulic cylinder in a retracted state provided by an embodiment of the present disclosure;

[0023] Figure 5 is a partially cutaway structural schematic diagram of a piston assembly provided by an embodiment of the present disclosure;

[0024] Figure 6 is a schematic diagram of a half-section structure of a piston assembly provided by an embodiment of the present disclosure;

[0025] Figure 7It is a structural schematic diagram of a hydraulic cylinder connected to a reversing valve provided in an embodiment of the present disclosure.

[0026] The symbols in the figure mean the following:

[0027] 1. Cylinder body; 11. Outer cylinder sleeve; 12. Inner center sleeve; 120. Annulus; 111. Cylinder head; 1111. Insertion section; 1112. Limiting flange; 112. Cylinder barrel; 113. Cylinder bottom; 1131. Connecting section; 1132. Positioning convex ring; 101. First oil port; 102. Second oil port; 103. Third oil port; 14. Connecting arm;

[0028] 2. Piston assembly; 201. First sealing chamber; 2011. First annular surface; 202. Second sealing chamber; 2021. Second annular surface; 203. Third sealing chamber; 2031. Third annular surface; 21. Outer sleeve; 22. Piston; 211. Outer cylinder; 212. Sealing ring stage; 23. Piston rod; 230. Installation space; 24. Displacement sensor; 241. Fixed head; 242. Detection rod; 243. Magnetic ring; 26. Connector;

[0029] 3. Pressure control assembly; 31. Flexible container;

[0030] 4. Protective cover; 40. Sealed space; 41. Watertight plug;

[0031] 100. Directional valve. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0033] The present disclosure provides a hydraulic cylinder, such as Figure 1 As shown, the hydraulic cylinder includes a cylinder body 1, a piston assembly 2 and a pressure control assembly 3.

[0034] Figure 2 is a schematic diagram of an axial cross-sectional structure of a hydraulic cylinder provided in an embodiment of the present disclosure, combined with Figure 2 , the piston assembly 2 is movably located in the cylinder body 1, and the piston assembly 2 and the cylinder body 1 define a first sealed chamber 201, a second sealed chamber 202, and a third sealed chamber 203. When the pressure of the first sealed chamber 201 acting on the piston assembly 2 is greater than the pressure of the second sealed chamber 202 acting on the piston assembly 2, the piston assembly 2 moves toward the inside of the cylinder body 1. When the pressure of the first sealed chamber 201 acting on the piston assembly 2 is less than the pressure of the second sealed chamber 202 acting on the piston assembly 2, the piston assembly 2 extends from the cylinder body 1.

[0035] The pressure control component 3 is located outside the cylinder body 1 and is connected to the cylinder body 1. The pressure control component 3 is connected to the third sealed chamber 203. The pressure control component 3 is configured as follows: when the piston assembly 2 is extended or retracted, a force is applied to the piston assembly 2 through the third sealed chamber 203 when the piston assembly 2 is extended or retracted. The force is the reaction force of the water pressure to which the piston assembly 2 is subjected when it is extended or retracted.

[0036] When the hydraulic cylinder provided by the embodiment of the present disclosure is placed in underwater operation, for example, when it is placed in seawater to drive deep-sea equipment to move, since the hydraulic cylinder includes a cylinder body 1 and a piston assembly 2, the cylinder body 1 can provide a mounting base for the piston assembly 2. At the same time, the piston assembly 2 is movably located in the cylinder body 1, and the piston assembly 2 and the cylinder body 1 define a first sealed cavity 201 and a second sealed cavity 202. When the pressure of the first sealed cavity 201 acting on the piston assembly 2 is greater than the pressure of the second sealed cavity 202 acting on the piston assembly 2, the piston assembly 2 moves toward the inside of the cylinder body 1. When the pressure of the first sealed cavity 201 acting on the piston assembly 2 is less than the pressure of the second sealed cavity 202 acting on the piston assembly 2, the piston assembly 2 extends from the cylinder body 1. In this way, the piston assembly 2 can be extended and retracted by filling oil into the first sealed cavity 201 or the second sealed cavity 202, thereby driving the deep-sea equipment to move.

[0037] Since the hydraulic cylinder further includes a pressure control component 3, and the pressure control component 3 is connected to the third sealed chamber 203, the pressure control component 3 is configured to apply a force to the piston component 2 through the third sealed chamber 203 when the piston component 2 is extended or retracted, and the force is the reaction force of the water pressure applied to the piston component 2 when the piston component 2 is extended or retracted. In this way, the piston component 2 will not be affected by the water pressure when moving, the output power is stabilized, and the control accuracy of the deep-sea equipment is improved.

[0038] Optionally, the cylinder body 1 includes an outer cylinder sleeve 11 and an inner center sleeve 12, the inner center sleeve 12 is located inside the outer cylinder sleeve 11, and the first end of the inner center sleeve 12 is connected to the first end of the outer cylinder sleeve 11, and an annulus 120 is formed between the inner center sleeve 12 and the outer cylinder sleeve 11. The piston assembly 2 includes an outer sleeve 21 and a piston 22, the outer sleeve 21 is coaxially sleeved outside the piston 22, and the first end of the outer sleeve 21 is sealed and connected to the piston 22, and the second end of the outer sleeve 21 is movably located in the annulus 120, and is sealed and connected to the inner wall of the outer cylinder sleeve 11 and the outer wall of the inner center sleeve 12, respectively. A first sealing chamber 201 is defined between the second end of the outer sleeve 21, the outer wall of the outer sleeve 21 and the inner wall of the outer cylinder sleeve 11; a second sealing chamber 202 is defined between the inner wall of the outer sleeve 21, the piston 22 and the inner wall of the inner center sleeve 12; a third sealing chamber 203 is defined between the second end of the outer sleeve 21, the inner wall of the outer cylinder sleeve 11 and the outer wall of the inner center sleeve 12.

[0039] In the above implementation, the piston assembly 2 is configured as a structure of an outer sleeve 21 and a piston 22, and the cylinder body 1 is configured as a structure of an outer cylinder sleeve 11 and an inner center sleeve 12, so that the piston assembly 2 can be configured as a double-layer structure, and the cylinder body 1 can be configured as a double-layer structure, thereby forming a first sealed chamber 201 between the outer sleeve 21 and the outer cylinder sleeve 11, a third sealed chamber 203 between the outer sleeve 21, the inner center sleeve 12 and the outer cylinder sleeve 11, and a second sealed chamber 202 between the outer sleeve 21, the piston 22 and the inner center sleeve 12. In other words, the above structure can simply define the first sealed chamber 201, the second sealed chamber 202 and the third sealed chamber 203.

[0040] Optionally, the end surface area of ​​the second end of the outer sleeve 21 is equal to the sum of the end surface area of ​​the first end of the outer sleeve 21 and the end surface area of ​​the first end of the piston 22 .

[0041] In the above implementation, since the third sealing cavity 203 is defined by the second end of the outer sleeve 21, the inner wall of the outer cylinder sleeve 11 and the outer wall of the inner center sleeve 12, the effective area of ​​the third sealing cavity 203 on the outer sleeve 21 is actually the end surface area of ​​the second end of the outer sleeve 21 (that is, Figure 1 After the piston assembly 2 is extended, the area of ​​the water pressure acting on the piston assembly 2 is the sum of the end surface area of ​​the first end of the outer sleeve 21 and the end surface area of ​​the first end of the piston 22 (that is, Figure 1 S4).

[0042] When the end surface area S3 of the second end of the outer sleeve 21 is equal to the sum S4 of the end surface area of ​​the first end of the outer sleeve 21 and the end surface area of ​​the first end of the piston 22, in order to make the force applied by the third sealing chamber 203 to the piston assembly 2 when the piston assembly 2 is extended and retracted equal to the force applied by the water pressure on the piston assembly 2, it is sufficient to ensure that the oil pressure in the third sealing chamber 203 is equal to the water pressure. It can be seen from this that the above arrangement can make the third sealing chamber 203 apply a force to the piston assembly 2 when the piston assembly 2 is extended and retracted, which is the reaction force of the water pressure to which the piston assembly 2 is subjected when it is extended and retracted, as long as the oil pressure in the third sealing chamber 203 is equal to the water pressure.

[0043] Optionally, the outer sleeve 21 includes an outer cylinder 211 and a sealing ring 212 , wherein the sealing ring 212 is sealingly sleeved outside a first end of the outer cylinder 211 and connected to the outer cylinder 211 .

[0044] The first end of the outer cylinder 211 is movably located in the annulus 120, and the first end of the outer cylinder 211 is located outside the cylinder 1. Along the moving direction of the piston 22, the first sealing chamber 201 and the third sealing chamber 203 are located on opposite sides of the sealing ring stage 212 respectively.

[0045] In the above implementation, the outer sleeve 21 is configured in the form of an outer cylinder body 211 and a sealing ring 212, so that the outer sleeve 21 can be sealed and connected with the inner wall of the outer cylinder sleeve 11 and the outer wall of the inner center sleeve 12 through the sealing ring 212. At the same time, the second sealing chamber 202 is isolated and separated from the first sealing chamber 201 by the outer cylinder body 211.

[0046] In this embodiment, the outer cylinder 211 and the sealing ring 212 are an integral structure, which is easy to manufacture and also convenient to realize the sealing connection between the outer cylinder 211 and the sealing ring 212.

[0047] Figure 3 is a schematic diagram of a structure of a hydraulic cylinder in a state of maximum extension displacement provided by an embodiment of the present disclosure, combined with Figure 3 When in use, when the pressure of the second sealing chamber 202 acting on the piston assembly 2 is greater than the pressure of the first sealing chamber 201 acting on the piston assembly 2, the oil in the second sealing chamber 202 can push the piston 22, so that the piston 22 extends from the cylinder body 1 together with the outer cylinder body 211, thereby realizing the extension of the piston assembly 2.

[0048] Figure 4 is a schematic diagram of a structure of a hydraulic cylinder in a contracted state provided by an embodiment of the present disclosure, combined with Figure 4 When the pressure of the first sealing chamber 201 on the piston assembly 2 is greater than the pressure of the second sealing chamber 202 on the piston assembly 2, the oil in the first sealing chamber 201 can push the sealing ring 212, so that the sealing ring 212 moves toward the inside of the cylinder body 1 with the outer cylinder body 211 and gradually retracts into the cylinder body 1.

[0049] Combination Figures 2 to 4 Since the third sealing chamber 203 and the first sealing chamber 201 are located on opposite sides of the sealing ring stage 212, when the piston assembly 2 extends out of the cylinder body 1, the piston assembly 2 will be subject to the resistance of water pressure. At this time, the third sealing chamber 203 can provide a direction to the sealing ring stage 212. Figure 1 When the piston assembly 2 moves toward the inside of the cylinder body 1 and retracts into the cylinder body 1, the part of the piston assembly 2 extending out of the cylinder body 1 will be pushed by the water pressure to help it retract into the cylinder body 1. At this time, the third sealing chamber 203 can provide a force to the sealing ring 212 to hinder the movement of the sealing ring 212, thereby offsetting the water pressure.

[0050] In this embodiment, in order to achieve the sealing connection between the sealing ring stage 212 and the inner center sleeve 12 and the outer cylinder sleeve 11, the inner wall of the outer cylinder body 211 has a plurality of sealing ring grooves spaced apart along the axis of the outer cylinder body 211. The outer wall of the sealing ring stage 212 has a plurality of sealing ring grooves spaced apart along the axis of the sealing ring stage 212. A sealing ring is correspondingly installed in each sealing ring groove.

[0051] Optionally, the piston assembly 2 further comprises a piston rod 23, the first end of which is connected to the piston 22, the piston rod 23 is coaxially located in the outer cylinder 211, and the second end of the piston rod 23 is movably located in the inner center sleeve 12. The interior of the piston rod 23 has an installation space 230 for installing a displacement sensor.

[0052] In the above implementation, the piston rod 23 is used to install a displacement sensor so that the telescopic stroke of the piston assembly 2 can be detected in real time through the displacement sensor.

[0053] Optionally, the hydraulic cylinder also includes a protective cover 4, which is located outside the outer cylinder sleeve 11 and connected to one end of the outer cylinder sleeve 11. A sealed space 40 is formed between the protective cover 4 and the end surface of the outer cylinder sleeve 11. The sealed space 40 is connected to the installation space 230, and the displacement sensor is located in the sealed space 40 and the installation space 230.

[0054] In the above implementation, the protective cover 4 can protect the displacement sensor so that the displacement sensor is isolated from the seawater, thereby preventing the displacement sensor from being affected by the seawater.

[0055] It is understandable that a watertight plug 41 may also be inserted into the protective cover 4 . The watertight plug 41 is mounted and fixed on the side wall of the protective cover 4 . The watertight plug 41 is used to be electrically connected to the cable terminal of the displacement sensor 24 .

[0056] In this embodiment, the installation space 230 is in the shape of a strip hole, and the extension direction of the installation space 230 is the axial direction of the piston rod 23. The displacement sensor 24 is a magnetostrictive sensor. The displacement sensor 24 includes a fixed head 241, a detection rod 242 and a magnetic ring 243. Among them, the fixed head 241 is located in the sealed space 40 and is connected to the end of the outer cylinder sleeve 11. The detection rod 242 is located in the coaxial installation space 230. The magnetic ring 243 is located in the piston rod 23 and is coaxially connected to the piston rod 23. The magnetic ring 243 is sleeved outside the detection rod 242 and is non-contact with the detection rod 242. In this way, the displacement sensor 24 can be placed through the sealed space 40 and the installation space 230. The magnetic ring 243 moves with the piston rod 23. The detection rod 242 detects the position of the magnetic ring 243, so that the position of the piston rod 23 can be monitored in real time, and then the displacement of the piston 22 can be obtained.

[0057] Combination Figures 1 to 4In this embodiment, the cross-sections of the piston 22 and the piston rod 23 are both circular structures, and the annular surface corresponding to the cross-section of the piston 22 minus the cross-section of the piston rod 23 is the second annular surface 2021 ( Figure 1 The end surface area S1 of the sealing ring platform 212 is equal to the area S2 of the second annular surface 2021.

[0058] In the above implementation, the difference S2 between the cross-sectional area of ​​the piston 22 and the cross-sectional area of ​​the piston rod 23 is equal to the annular surface area S1 of the sealing ring stage 212, so that the action area of ​​the first sealing chamber 201 on the piston assembly 2 can be the same as the action area of ​​the second sealing chamber 202 on the piston assembly 2. Therefore, when the oil of the same oil pressure is input into one of the first sealing chamber 201 and the second sealing chamber 202, the piston assembly 2 is subjected to the same force when extending and retracting, thereby making the extension speed and retraction speed of the piston assembly 2 the same, which facilitates the control of the piston assembly 2.

[0059] Figure 5 is a partially cutaway structural schematic diagram of a piston assembly provided by an embodiment of the present disclosure, Figure 6 is a schematic diagram of a half-section structure of a piston assembly provided by an embodiment of the present disclosure, combined with Figure 5 and Figure 6 The piston assembly 2 further includes a joint 26, which is located outside the cylinder body 1 and connected to an end of the piston 22 away from the piston rod 23. The joint 26 is provided with a connecting hole, and the joint 26 is used to connect with the deep-sea equipment through the connecting hole to drive the deep-sea equipment to move.

[0060] Combination Figure 1 and Figure 2 Optionally, the pressure control component 3 includes a flexible container 31, the flexible container 31 is filled with oil, the flexible container 31 can be deformed under the action of water pressure, and after deformation, the oil inside can be driven into the third sealed cavity 203.

[0061] In the above implementation, since the flexible container 31 is filled with oil, when the flexible container 31 is placed in seawater, the water pressure of the seawater will squeeze the flexible container 31, so that the flexible container 31 is deformed and the oil in the flexible container 31 is driven out and flows into the third sealed cavity 203. That is, the pressure on the oil in the flexible container 31 is the seawater pressure. After the flexible container 31 is connected to the third sealed cavity 203, the oil pressure in the third sealed cavity 203 is the seawater pressure. In this way, the oil pressure in the third sealed cavity 203 can be simply controlled to be the seawater pressure.

[0062] Optionally, the flexible container 31 is an annular structure, and the flexible container 31 is sleeved outside the cylinder body 1 .

[0063] In the above implementation, the flexible container 31 is an annular structure, which can increase the contact area between the flexible container and seawater, so that the flexible container can be quickly deformed under the seawater pressure and transfer the oil into the third sealing cavity 203.

[0064] In other examples, the flexible container 31 may also be in other structures, such as circular, oval, etc.

[0065] In this embodiment, the flexible container 31 is a capsule or a bladder, so that the oil pressure of the oil entering the third sealed cavity 203 can be the seawater pressure.

[0066] Continue to see Figure 2 Optionally, the outer cylinder sleeve 11 includes a cylinder head 111, a cylinder barrel 112 and a cylinder bottom 113. The cylinder head 111 is located outside the first end of the cylinder barrel 112, and the sealing sleeve is outside the outer sleeve 21, and the cylinder head 111 is sealed and connected to the cylinder barrel 112. The cylinder bottom 113 is located outside the second end of the cylinder barrel 112, and is sealed and connected to the inner center sleeve 12 and the cylinder barrel 112 respectively.

[0067] In the above implementation, the outer cylinder sleeve 11 is configured as the above structure, so that the outer cylinder sleeve 11 can be a detachable structure, thereby facilitating the assembly of the piston assembly 2 and the like.

[0068] In this embodiment, the cylinder head 111 is an annular structure, and the cylinder head 111 includes an insertion section 1111 and a limiting flange 1112, and the limiting flange 1112 is connected to the outer wall of the insertion section 1111. When the cylinder head 111 is connected to the cylinder barrel 112, the insertion section 1111 is located between the outer cylinder body 211 and the cylinder barrel 112. One side of the limiting flange 1112 abuts against the end surface of the cylinder barrel 112. The limiting flange 1112 and the cylinder barrel 112 are fastened together by a plurality of bolts or the like. A first oil port 101 is provided on the outer wall of the cylinder barrel 112 at one end close to the cylinder head 111, and the first oil port 101 is located on the side of the limiting flange 1112 facing the cylinder bottom 113. The first oil port 101 is communicated with the first sealing chamber 201.

[0069] In order to improve the sealing performance of the first sealing cavity 201, the inner wall of the insert section 1111 is provided with a plurality of sealing grooves arranged at intervals along the axis of the cylinder barrel 112, each of which is provided with a sealing ring. The outer wall of the insert section 1111 is also provided with a sealing groove, each of which is provided with a sealing ring.

[0070] The cylinder bottom 113 is also an annular structure, and includes a connecting section 1131 and a positioning convex ring 1132, wherein the positioning convex ring 1132 is connected to the outer wall of the connecting section 1131. When the cylinder bottom 113 is connected to the cylinder barrel 112, the connecting section 1131 is located inside the cylinder barrel 112. One side of the positioning convex ring 1132 abuts against the other end surface of the cylinder barrel 112. The positioning convex ring 1132 and the cylinder barrel 112 are fastened together by a plurality of bolts or the like.

[0071] In order to improve the sealing performance of the third sealed cavity 203, a sealing groove is provided on the outer wall of the connecting section 1131, and a sealing ring is also installed in the sealing groove.

[0072] A second oil port 102 is provided on the end surface of the connecting section 1131, and the second oil port 102 is communicated with the second sealed cavity 202. A third oil port 103 is provided on the outer wall of one end of the cylinder barrel 112 close to the positioning protruding ring 1132, and the third oil port 103 is located on the side of the positioning protruding ring 1132 facing the cylinder head 111. The third oil port 103 is communicated with the third sealed cavity 203. In this way, high-pressure oil can be introduced into the first sealed cavity 201 through the first oil port 101, and high-pressure oil can also be introduced into the second sealed cavity 202 through the second oil port 102. At the same time, the oil can flow between the flexible container 31 and the third sealed cavity 203 through the third oil port 103.

[0073] In this embodiment, the cylinder cover 111 and the cylinder bottom 113 are both annular plate structures. In order to facilitate processing, the cylinder bottom 113 and the inner center sleeve 12 are an integral structure.

[0074] In addition, in order to facilitate the connection between the cylinder bottom 113 and other structures, the cylinder body 1 further includes two connecting arms 14, which are located outside the outer cylinder sleeve 11 and arranged opposite to each other, one end of each connecting arm 14 is connected to a side of the cylinder bottom 113 away from the cylinder cover 111, and the other end of the connecting arm 14 is arranged away from the piston rod 23. A connecting hole is provided at the other end of each connecting arm 14. The protective cover 4 is located between the two connecting arms 14.

[0075] The following briefly introduces the working process of the hydraulic cylinder provided in the embodiment of the present disclosure:

[0076] When in use, the first sealed chamber 201 and the second sealed chamber 202 of the hydraulic cylinder are respectively connected to the two working oil ports of the reversing valve in a one-to-one correspondence. By controlling the valve core position of the reversing valve, the hydraulic cylinder is extended and retracted.

[0077] Figure 7 is a structural diagram of a hydraulic cylinder connected to a reversing valve according to an embodiment of the present disclosure, Figure 7When the reversing valve 100 is in the middle position, the second working oil port b and the first working oil port a of the reversing valve 100 are connected to the oil return port t. At this time, the first sealed chamber 201 and the second sealed chamber 202 of the hydraulic cylinder are both connected to the oil tank, and there is no oil pressure in the first sealed chamber 201 and the second sealed chamber 202. In addition, because the oil in the flexible container 31 is transferred to the third sealed chamber 203 of the hydraulic cylinder under the action of water pressure, the oil pressure of the third sealed chamber 203 is the same as the external water pressure, and because the area of ​​the third annular surface 2031 is equal to the area of ​​the extended cross section of the piston 22, the force of the piston 22 is balanced and it will not move.

[0078] The reversing valve 100 is energized in the left position, at which time the oil inlet p of the reversing valve 100 is connected to the second working oil port b, and the first working oil port a is connected to the oil return port t. At this time, the second oil port 102 of the hydraulic cylinder enters oil, and the first oil port 101 discharges oil, and the inlet and outlet oil flow rates are the same. Under the action of water pressure, the oil in the flexible container 31 flows to the third sealed chamber 203 of the hydraulic cylinder through the third oil port 103, and is balanced with the external water pressure on the piston rod 23. The piston rod 23 is only affected by the pressure of the oil source, pushing the piston rod 23 to extend.

[0079] The reversing valve 100 is energized in the right position, and the oil inlet p of the reversing valve 100 is connected to the first working oil port a, and the second working oil port b is connected to the oil return port t. At this time, the first oil port 101 of the hydraulic cylinder enters oil, and the second oil port 102 exits oil, and the inlet and outlet oil flow rates are the same. The oil in the third sealed chamber 203 of the hydraulic cylinder flows to the flexible container 31, and the external water pressure on the piston rod 23 remains balanced. The piston rod 23 is only subjected to the pressure of the oil source, which pushes the piston rod 23 to extend.

[0080] With the hydraulic cylinder provided by the embodiment of the present disclosure, the third annular surface 2031 of the hydraulic cylinder is equal to the area S4 of the extended cross section of the piston rod, and because the oil pressure and water pressure of the third sealed chamber 203 are the same, the external water pressure to which the piston rod of the hydraulic cylinder is subjected during movement is always balanced with the oil pressure in the third sealed chamber 203 and will not be affected by the water depth. At the same time, the areas of the first annular surface 2011 and the second annular surface 2021 of the hydraulic cylinder are equal, ensuring that the flow rate of the oil is the same when the hydraulic cylinder is extended and retracted, thereby improving the output power and control accuracy of the hydraulic cylinder.

[0081] The hydraulic cylinder provided by the present invention has a simple structure and is easy to maintain, and can safely and reliably realize servo control of the actuator cylinder, and is particularly suitable for some small ships or special working conditions without magnetism or electricity.

[0082] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A hydraulic cylinder, characterized in that: The hydraulic cylinder comprises a cylinder body (1), a piston assembly (2) and a pressure control assembly (3); The piston assembly (2) is movably located in the cylinder body (1); the piston assembly (2) and the cylinder body (1) define a first sealed chamber (201), a second sealed chamber (202), and a third sealed chamber (203); when the pressure of the first sealed chamber (201) is greater than the pressure of the second sealed chamber (202), the piston assembly (2) moves toward the inside of the cylinder body (1); when the pressure of the first sealed chamber (201) is less than the pressure of the second sealed chamber (202), the piston assembly (2) extends from the cylinder body (1); The pressure control component (3) is located outside the cylinder body (1) and is connected to the cylinder body (1). The pressure control component (3) is connected to the third sealed chamber (203). The pressure control component (3) is configured to apply a force to the piston assembly (2) through the third sealed chamber (203) when the piston assembly (2) is extended or retracted, and the force is a reaction force of the water pressure to which the piston assembly (2) is subjected when it is extended or retracted.

2. The hydraulic cylinder according to claim 1, characterized in that: The cylinder body (1) comprises an outer cylinder sleeve (11) and an inner center sleeve (12), wherein the inner center sleeve (12) is located inside the outer cylinder sleeve (11), and a first end of the inner center sleeve (12) is connected to a first end of the outer cylinder sleeve (11), and an annulus (120) is formed between the inner center sleeve (12) and the outer cylinder sleeve (11); The piston assembly (2) comprises an outer sleeve (21) and a piston (22), wherein the outer sleeve (21) is coaxially sleeved outside the piston (22), and a first end of the outer sleeve (21) is sealingly connected to the piston (22), and a second end of the outer sleeve (21) is movably located in the annulus (120) and is sealingly connected to an inner wall of the outer cylinder sleeve (11) and an outer wall of the inner center sleeve (12), respectively; The first sealing chamber (201) is defined between the second end of the outer sleeve (21), the outer wall of the outer sleeve (21) and the inner wall of the outer cylinder sleeve (11); the second sealing chamber (202) is defined between the inner wall of the outer sleeve (21), the piston (22) and the inner wall of the inner center sleeve (12); and the third sealing chamber (203) is defined between the second end of the outer sleeve (21), the inner wall of the outer cylinder sleeve (11) and the outer wall of the inner center sleeve (12).

3. The hydraulic cylinder according to claim 2, characterized in that: The end surface area of ​​the second end of the outer sleeve (21) is equal to the sum of the end surface area of ​​the first end of the outer sleeve (21) and the end surface area of ​​the first end of the piston (22).

4. The hydraulic cylinder according to claim 2, characterized in that: The outer sleeve (21) comprises an outer cylinder (211) and a sealing ring (212). The sealing ring (212) is sealingly sleeved outside a first end of the outer cylinder (211) and is connected to the outer cylinder (211). The first end of the outer cylinder (211) is movably located in the annulus (120), and the second end of the outer cylinder (211) is located outside the cylinder (1).

5. The hydraulic cylinder according to claim 4, characterized in that: The piston assembly (2) further comprises a piston rod (23), a first end of the piston rod (23) being connected to the piston (22), the piston rod (23) being coaxially located in the outer cylinder (211), and a second end of the piston rod (23) being movably located in the inner center sleeve (12); The piston rod (23) has an installation space (230) inside for installing a displacement sensor.

6. The hydraulic cylinder according to claim 5, characterized in that: The difference between the cross-sectional area of ​​the piston (22) and the cross-sectional area of ​​the piston rod (23) is equal to the end surface area of ​​the sealing ring platform (212).

7. The hydraulic cylinder according to claim 5, characterized in that: The hydraulic cylinder further comprises a protective cover (4), the protective cover (4) being located outside the outer cylinder sleeve (11) and connected to one end of the outer cylinder sleeve (11), a sealed space (40) being formed between the protective cover (4) and an end surface of the outer cylinder sleeve (11), the sealed space (40) being in communication with the installation space (230), and the displacement sensor being located in the sealed space (40) and the installation space (230).

8. The hydraulic cylinder according to any one of claims 1 to 7, characterized in that: The pressure control component (3) comprises a flexible container (31), the flexible container (31) is filled with oil, and the flexible container (31) can be deformed under the action of water pressure, and after deformation, the oil inside can be driven into the third sealed cavity (203).

9. The hydraulic cylinder according to claim 8, characterized in that: The flexible container (31) is an annular structure, and the flexible container (31) is sleeved outside the cylinder body (1).

10. The hydraulic cylinder according to claim 2, characterized in that: The outer cylinder sleeve (11) comprises a cylinder head (111), a cylinder barrel (112) and a cylinder bottom (113). The cylinder cover (111) is connected to the first end of the cylinder barrel (112) and is sleeved outside the outer sleeve (21); The cylinder bottom (113) is connected to the second end of the cylinder barrel (112) and is also connected to the inner center sleeve (12).

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