Piston rod oil inlet type hydraulic cylinder

Abstract

This utility model discloses a piston rod inlet hydraulic cylinder. The piston rod has an axially oriented oil passage for a rodless chamber and an oil passage for a rod chamber. A rotary joint is rotatably mounted on the extended end of the piston rod, and the rotary joint has an inlet and a return port that communicate with the external oil pipe. The inlet and return ports are connected to either the rodless or rod chamber oil passage. By adopting a piston rod inlet structure, this utility model places the rodless and rod chamber oil passages inside the piston rod, enabling convenient installation of the hydraulic cylinder in confined spaces and improving its adaptability in vehicle lifting operations. By setting a rotary joint at the piston rod connection and rotatably connecting it to the connection, relative rotation between the piston rod and the oil pipe is allowed, achieving a stable connection of the oil pipe, reducing the risk of failure, and improving the service life of the equipment.

Description

Technical Field

[0001] This utility model relates to a hydraulic cylinder, specifically a piston rod oil inlet type hydraulic cylinder. Background Technology

[0002] In vehicle lifting operations, hydraulic cylinders are often used to drive the wheel assembly to lift the vehicle off the ground, allowing the vehicle to be supported by outriggers to complete the relevant tasks. In this process, the hydraulic cylinder, as the core actuator, directly affects the safety and reliability of the operation.

[0003] However, the existing hydraulic cylinder design has significant limitations when applied in this field. Existing hydraulic cylinder ports are generally located on the cylinder barrel. However, because the hydraulic cylinder is located inside the vehicle body, the compact and complex internal space makes it difficult to directly connect the oil pipe to the port on the cylinder barrel. Furthermore, with prolonged vehicle movement, the oil pipe joints may loosen or experience fatigue fractures. Utility Model Content

[0004] The purpose of this invention is to provide a piston rod inlet hydraulic cylinder to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A piston rod inlet hydraulic cylinder, cylinder barrel; The piston assembly is slidably disposed inside the cylinder along a preset direction, and divides the internal cavity of the cylinder into a rodless chamber and a rod chamber; The piston rod includes a piston rod having an axially extending oil passage for a rodless chamber communicating with the rodless chamber and an oil passage for a rod chamber communicating with the rod chamber; and A rotary joint is rotatably mounted on the extended end of the piston rod and rotates along the axial direction of the piston rod. The rotary joint is provided with an oil inlet and an oil return port that communicate with the external oil pipe. The oil inlet and oil outlet are connected to the rodless chamber oil passage or the rod chamber oil passage. When the oil inlet is connected to one oil passage, the oil outlet is connected to the other oil passage. The piston rod has an extended state in which the oil inlet communicates with the oil passage of the rodless chamber, and a retracted state in which the oil inlet communicates with the oil passage of the rod chamber.

[0006] As a further embodiment of this utility model: the piston rod includes a rod body and a connecting part that are fixedly connected, and the rodless chamber oil passage and the rod chamber oil passage are opened in the rod body; A first oil groove and a second oil groove are provided on the outer peripheral surface of the connecting part; The first oil tank is connected to the oil passage of the rodless chamber; The second oil trough is connected to the oil passage of the rod chamber; When the piston rod is in the extended state, the oil inlet is connected to the first oil groove; When the piston rod is in the retracted state, the oil inlet is connected to the second oil groove.

[0007] As a further embodiment of this utility model: the oil inlet includes an oil port A and an oil port B, which are opened radially along the rotary joint. The oil port A is connected to the end of the rodless cavity oil passage away from the rodless cavity, and the oil port B is connected to the end of the rod cavity oil passage away from the rod cavity. When oil enters through one oil port, the other oil port can be used as an oil return port.

[0008] As a further embodiment of this utility model: the extended end of the piston rod is provided with a first oil groove and a second oil groove, both of which are annular grooves distributed at intervals along the axial direction of the piston rod. The first oil tank is connected to the A oil port and the rodless cavity oil passage respectively; The second oil tank is connected to the B oil port and the rod cavity oil passage, respectively.

[0009] As a further embodiment of this utility model: a rotary joint is sleeved on the outer periphery of the extended end of the piston rod and is rotatably connected by a locking member.

[0010] As a further embodiment of this utility model: the rod chamber oil passage includes an axial hole and a radial hole that are interconnected. The end of the axial hole away from the radial hole is connected to the oil inlet, and the end of the radial hole away from the axial hole is connected to the rod chamber. The axial hole extends along the axial direction of the piston rod, and the end of the axial hole near the rodless chamber is sealed by a plug.

[0011] As a further improvement of this utility model, a plurality of sealing elements are provided between the rotary joint and the extended end of the piston rod.

[0012] As a further embodiment of this utility model: the piston assembly further includes a piston, which is elastically sleeved on the embedded end of the piston rod. When the piston assembly moves telescopically, the piston divides the cavity of the cylinder into the rodless cavity and the rod cavity.

[0013] As a further improvement of this utility model: a piston sealing ring and / or a piston wear-resistant ring are installed at the mating point between the piston and the cylinder.

[0014] As a further embodiment of this utility model: the cylinder includes a cylinder body, an end cap, and a cylinder bottom. The two ends of the cylinder body are sealed together by the end cap and the cylinder bottom. Multiple sealing grooves are opened along the axial direction on the inner wall of the end cap. From the outside to the inside of the end cap, a dustproof ring, a guide sealing ring, an impact-resistant sealing ring, and a guide wear-resistant ring are installed in sequence in the multiple sealing grooves.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: A piston rod inlet hydraulic cylinder, by adopting a piston rod inlet structure, sets the rodless chamber oil passage and the rod chamber oil passage inside the piston rod, solving the problem that the oil port of the existing hydraulic cylinder is located on the cylinder barrel, making it difficult to connect the oil pipe in the compact space and complex structure of the vehicle body. This realizes the convenient installation of the hydraulic cylinder in the confined space and improves the adaptability in vehicle lifting operation scenarios. By setting a rotary joint at the piston rod connection part and rotatably connecting it to the connection part, relative rotation between the piston rod and the oil pipe is allowed, solving the problems of joint loosening and fatigue fracture caused by the synchronous rotation of the oil pipe with the wheel. This achieves stable connection of the oil pipe, reduces the risk of failure, and improves the service life of the equipment. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of a piston rod inlet hydraulic cylinder.

[0017] In the diagram: 1. Cylinder barrel; 2. End cap; 21. Dustproof ring; 22. Guide seal ring; 23. Impact-resistant seal ring; 24. Guide wear-resistant ring; 3. Cylinder bottom; 4. Piston assembly; 41. Piston seal ring; 411. Piston wear-resistant ring; 412. Piston rod; 42. Connecting part; 43. First oil groove; 431. Second oil groove; 432. Rodless chamber oil passage; 5. Rod chamber oil passage; 6. Locking element; 7. Rotary joint; 8. Oil port A; 81. Oil port B; 82. Seal; 9. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figure 1 In this embodiment of the utility model, a piston rod inlet hydraulic cylinder is used to communicate with an external oil pipe. It includes a cylinder barrel 1, and a piston assembly 4 is provided inside the cylinder barrel 1. The piston assembly 4 divides the hydraulic cylinder into two sealed spaces: a rodless chamber and a rod chamber. The piston assembly 4 is composed of a piston 41 and a piston rod 42. One end of the piston rod 42 passes through the end cover 2 and extends out of the cylinder barrel 1, and the other end is connected to the center of the piston 41.

[0020] The piston rod 42 has an axially formed oil passage 5 for the rodless chamber and an oil passage 6 for the rod chamber.

[0021] The extended end of the piston rod 42 is fitted with a rotary joint 8 that can rotate along the axis of the piston rod 42 via a locking member 7. The rotary joint 8 is sleeved on the outer periphery of the connecting part 43 and rotatably connected to it. The rotary joint 8 has an oil inlet and an oil return port that communicate with external pipelines. The oil inlet and oil return port are connected to the rodless chamber oil passage 5 or the rod chamber oil passage 6. When the oil inlet is connected to one oil passage, the oil return port is connected to the other oil passage. When the oil inlet is connected to the rodless chamber oil passage 5, hydraulic oil flows into the rodless chamber through the oil inlet, causing the piston assembly 4 to extend, and the hydraulic oil in the rod chamber flows out through the oil return port. When the oil inlet is connected to the rod chamber oil passage 6, hydraulic oil flows into the rod chamber through the oil inlet, causing the piston assembly 4 to retract, and the hydraulic oil in the rodless chamber flows out through the oil return port.

[0022] A connecting part 43 is provided on one side of the extended end of the piston rod 42. A first oil groove 431 and a second oil groove 432 are provided on the outer peripheral surface of the connecting part 43. The first oil groove 431 is connected to the oil passage 5 of the rodless chamber, and the second oil groove 432 is connected to the oil passage 6 of the rod chamber. When the piston rod is extended, the oil inlet is connected to the first oil groove 431, and when the piston rod is retracted, the oil inlet is connected to the second oil groove 432.

[0023] In an embodiment of this utility model, the oil inlet includes an A oil port 81 and a B oil port 82. The A oil port 81 and the B oil port 82 are opened radially along the rotary joint 8. The A oil port 81 is connected to the end of the rodless cavity oil passage 5 away from the rodless cavity, and the B oil port 82 is connected to the end of the rod cavity oil passage 6 away from the rod cavity. Since two separate A oil ports 81 and B oil ports 82 are provided to connect to the two oil passages respectively, the A oil ports 81 and B oil ports 82 not only have the function of oil inlet but also the function of oil return. Therefore, it is not necessary to set a separate oil return port. When oil is inlet at one oil port, the other oil port can be used as an oil return port.

[0024] The first oil groove 431 and the second oil groove 432 are annular grooves opened around the circumference of the connecting part 43. The two oil grooves are distributed at intervals along the axial direction of the connecting part 43. The first oil groove 431 is connected to the A oil port 81 and the rodless cavity oil passage 5 respectively. The second oil groove 432 is connected to the B oil port 82 and the rod cavity oil passage 6 respectively.

[0025] The rodless chamber oil passage 5 and the rod chamber oil passage 6 are axial holes opened from the bottom of the piston rod 42 upward along the axial direction. The end of the axial hole of the rodless chamber oil passage 5 away from the rodless chamber is connected to the first oil groove 431, and the end closer to the rodless chamber is directly connected to the rodless chamber. The rod chamber oil passage 6 is composed of an axial hole and a radial hole. The end of the axial hole away from the radial hole is connected to the second oil groove 432, and the end of the radial hole away from the axial hole is connected to the rod chamber. The axial hole runs through the piston rod 42 along the axial direction, and the end of the axial hole close to the rodless chamber is sealed by a welded plug.

[0026] Multiple seals 9 are provided between the rotary joint 8 and the connecting part 43. The seals 9 are embedded in the mating gap between the rotary joint 8 and the connecting part 43. The seals 9 are respectively set on both sides of the axial direction of the two oil grooves to isolate the hydraulic oil between the first oil groove 431 and the second oil groove 432, and at the same time prevent the oil from leaking out.

[0027] During operation, when high-pressure hydraulic oil enters the rodless chamber through port A 81, the first oil groove 431, and the rodless chamber oil passage 5, the hydraulic pressure acts on the end face of piston 41, generating thrust. Under the action of thrust, piston 41 will drive piston rod 42 to move towards the rod chamber side, realizing the extension action of piston rod 42. The hydraulic oil in the rod chamber returns through port B 82. Conversely, when high-pressure hydraulic oil enters the rod chamber through port B 82, the second oil groove 432, and the rod chamber oil passage 6, the pressure acts on the other side of piston 41, pushing piston 41 towards the rodless chamber side, causing piston rod to retract. The hydraulic oil in the rodless chamber returns through port A 81. Because of the piston rod oil inlet structure, the oil port is connected through the internal oil passage of the piston rod, which avoids the problem of the hydraulic cylinder being difficult to install in the vehicle body due to space constraints. At the same time, the rotary joint 8 allows the piston rod 42 to rotate relative to the oil pipe, which can prevent the oil pipe from rotating synchronously with the wheel, reduce the risk of joint loosening and fatigue fracture, and improve the service life of the equipment.

[0028] A piston seal ring 411 and a piston wear ring 412 are installed on the outer periphery of the piston 41. The piston seal ring 411 ensures that the piston 41 fits tightly against the inner wall of the cylinder 1, achieving oil isolation between the rodless chamber and the rod chamber. The piston wear ring 412 contacts the inner wall of the cylinder 1, reducing friction and wear when the piston 41 moves.

[0029] The cylinder barrel 1 includes a cylinder body, end caps 2, and a cylinder bottom 3. The cylinder body is the main load-bearing component of the hydraulic cylinder. The two ends of the cylinder body are sealed together by the end caps 2 and the cylinder bottom 3. Multiple sealing grooves are formed axially on the inner wall of the end caps 2. From the outside to the inside of the end caps 2, a dustproof ring 21, a guide sealing ring 22, an impact-resistant sealing ring 23, and a guide wear-resistant ring 24 are installed sequentially in the multiple sealing grooves. The dustproof ring 21 prevents external dust and impurities from entering the cylinder barrel 1; the guide sealing ring 22 prevents oil leakage in the rod cavity; the impact-resistant sealing ring 23 enhances the sealing reliability under impact loads; and the guide wear-resistant ring 24 reduces friction and wear with the piston rod 42, extending the service life of the components.

[0030] The working principle of this utility model is as follows: The hydraulic cylinder works based on the conversion of hydraulic energy and mechanical energy, and achieves stable operation through the coordinated operation of the piston rod's internal oil circuit and rotary joint. When high-pressure hydraulic oil enters the rodless chamber through port A 81 via the first oil groove 431 and the rodless chamber oil circuit channel 5, the oil pressure acts on the end face of piston 41, generating thrust. Under the action of thrust, piston 41 will drive piston rod 42 to move towards the rod chamber side, realizing the extension action of piston rod 42; conversely, when high-pressure hydraulic oil enters the rod chamber through port B 82 via the second oil groove 432 and the rod chamber oil circuit channel 6, the pressure acts on the other side of piston 41, pushing piston 41 towards the rodless chamber side, causing piston rod to retract. Because of the piston rod oil inlet structure, the oil port is connected through the internal oil passage of the piston rod, which avoids the problem of the hydraulic cylinder being difficult to install in the vehicle body due to space constraints. At the same time, the rotary joint 8 allows the piston rod 42 to rotate relative to the oil pipe, which can prevent the oil pipe from rotating synchronously with the wheel, reduce the risk of joint loosening and fatigue fracture, and improve the service life of the equipment.

[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A piston rod inlet hydraulic cylinder for connecting to an external oil pipe, characterized in that, include Cylinder (1); The piston assembly (4) is slidably disposed in the cylinder (1) along a preset direction and divides the internal cavity of the cylinder (1) into a rodless cavity and a rod cavity; Includes a piston rod (42), the piston rod (42) having an axially formed rodless chamber oil passage (5) communicating with the rodless chamber, and a rod chamber oil passage (6) communicating with the rod chamber; and A rotary joint (8) is rotatably mounted on the extended end of the piston rod (42) and rotates along the axial direction of the piston rod (42). The rotary joint (8) is provided with an oil inlet and an oil return port that communicate with the external oil pipe. The oil inlet and oil outlet are connected to the rodless chamber oil passage (5) or the rod chamber oil passage (6). When the oil inlet is connected to one oil passage, the oil outlet is connected to the other oil passage. The piston rod (42) has an extended state in which the oil inlet is connected to the rodless chamber oil passage (5), and a retracted state in which the oil inlet is connected to the rod chamber oil passage (6).

2. The piston rod inlet hydraulic cylinder according to claim 1, characterized in that, The piston rod (42) includes a rod body and a connecting part (43) that are fixedly connected. The rodless chamber oil passage (5) and the rod chamber oil passage (6) are opened in the rod body. A first oil groove (431) and a second oil groove (432) are provided on the outer peripheral surface of the connecting part (43); The first oil tank (431) is connected to the rodless cavity oil passage (5); The second oil trough (432) is connected to the rod chamber oil passage (6); When the piston rod (42) is in the extended state, the oil inlet is connected to the first oil groove (431); When the piston rod (42) is in the retracted state, the oil inlet is connected to the second oil groove (432).

3. A piston rod inlet hydraulic cylinder according to claim 1 or 2, characterized in that, The oil inlet includes an A port (81) and a B port (82). The A port (81) and the B port (82) are opened radially along the rotary joint (8). The A port (81) is connected to the end of the rodless cavity oil passage (5) away from the rodless cavity. The B port (82) is connected to the end of the rod cavity oil passage (6) away from the rod cavity. When oil enters through one port, the other port can be used as a return port.

4. A piston rod inlet hydraulic cylinder according to claim 3, characterized in that, The piston rod (42) has a first oil groove (431) and a second oil groove (432) at its extended end. The first oil groove (431) and the second oil groove (432) are both annular grooves that are spaced apart along the axial direction of the piston rod (42). The first oil tank (431) is connected to the A oil port (81) and the rodless cavity oil passage (5) respectively; The second oil tank (432) is connected to the B oil port (82) and the rod cavity oil passage (6) respectively.

5. A piston rod inlet hydraulic cylinder according to claim 1, characterized in that, The rotary joint (8) is sleeved on the outer periphery of the extended end of the piston rod (42) and is rotatably connected by the locking member (7).

6. A piston rod inlet hydraulic cylinder according to any one of claims 1, 2, and 5, characterized in that, The rod chamber oil passage (6) includes an axial hole and a radial hole that are interconnected. The end of the axial hole away from the radial hole is connected to the oil inlet, and the end of the radial hole away from the axial hole is connected to the rod chamber. The axial hole extends along the axial direction of the piston rod (42), and the end of the axial hole near the rodless chamber is sealed by a plug.

7. A piston rod inlet hydraulic cylinder according to any one of claims 1, 2, and 5, characterized in that, Multiple seals (9) are provided between the rotary joint (8) and the extended end of the piston rod (42).

8. A piston rod inlet hydraulic cylinder according to any one of claims 1, 2, and 5, characterized in that, The piston assembly (4) further includes a piston (41), which is elastically sleeved on the embedded end of the piston rod (42). When the piston assembly (4) moves in extension and retraction, the piston (41) divides the cavity of the cylinder into the rodless cavity and the rod cavity.

9. A piston rod inlet hydraulic cylinder according to claim 8, characterized in that, A piston seal ring (411) and / or a piston wear ring (412) are installed at the mating point between the piston (41) and the cylinder (1).

10. A piston rod inlet hydraulic cylinder according to claim 1, characterized in that, The cylinder (1) includes a cylinder body, an end cap (2) and a cylinder bottom (3). The two ends of the cylinder body are sealed together by the end cap (2) and the cylinder bottom (3). Multiple sealing grooves are opened along the axial direction on the inner wall of the end cap (2). From the outside to the inside of the end cap (2), a dustproof ring (21), a guide sealing ring (22), an impact-resistant sealing ring (23) and a guide wear-resistant ring (24) are installed in the multiple sealing grooves in sequence.

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