Novel oil cylinder built-in buffer mechanism

Abstract

A novel oil cylinder built-in buffer mechanism belongs to the technical field of hydraulic oil cylinders. Which comprises a cylinder barrel and a piston rod, and is characterized by further comprising a guide sleeve, and the guide sleeve is fixed to a port of the inner cavity wall of the cylinder barrel and arranged outside the piston rod in a sleeving mode; the piston rod is of a hollow structure, and a plurality of sets of oil through holes are formed in the side wall of the piston rod, distributed in the axial direction of the piston rod at intervals and located at the tail section of the stroke of the piston rod. When the oil cylinder stretches out to the tail section of the stroke, the multiple sets of oil through holes in the oil cylinder piston rod are sequentially shielded by the guide sleeve of the cylinder barrel, the oil through area is reduced, and the speed reducing and buffering effects are achieved. According to the utility model, the arrangement structure can be simplified, additional hydraulic valves are not added, and the conventional arrangement space of the oil cylinder is not occupied.

Description

Technical Field

[0001] This utility model relates to a novel built-in buffer mechanism for hydraulic cylinders, belonging to the field of hydraulic cylinder technology. Background Technology

[0002] The buffer mechanism is an important functional device in hydraulic cylinders. Currently, there are two main types of buffer mechanisms for hydraulic cylinders: external and internal. External buffering involves adding a buffer circuit to the hydraulic circuit, which increases the complexity of the system and also significantly raises the cost. Internal buffering generally uses a built-in buffer valve, which also suffers from high cost. Furthermore, built-in buffer valves have disadvantages such as unstable operation and limited installation space. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of the prior art by providing a novel built-in buffer mechanism for hydraulic cylinders, which simplifies the layout, eliminates the need for additional hydraulic valves, and does not occupy the conventional layout space of hydraulic cylinders.

[0004] The technical solution of this utility model is as follows:

[0005] A novel hydraulic cylinder built-in buffer mechanism includes a cylinder barrel and a piston rod. The mechanism is characterized by the addition of a guide sleeve, which is fixed to the port position of the inner wall of the cylinder barrel and sleeved on the outside of the piston rod. The piston rod has a hollow structure, and the side wall of the piston rod is provided with several sets of oil passage holes, which are distributed at intervals along the axial direction of the piston rod and located at the end of the piston rod's stroke.

[0006] In the above scheme, the piston rod is hollow inside, and multiple sets of oil passage holes (at least two sets) are arranged on the end of the piston rod stroke. When the oil cylinder extends to the end of the stroke, several sets of oil passage holes on the piston rod are blocked by the guide sleeve on the inner wall of the cylinder in turn, reducing the oil passage area and achieving the effect of speed reduction and buffering.

[0007] Furthermore, the oil passage is composed of several sets of buffer oil passages and a set of anti-jamming oil passages, with the anti-jamming oil passage located on the outermost side and close to the tail of the piston rod; the inner wall of the guide sleeve has an annular groove on one end face near the tail of the piston rod.

[0008] In the above scheme, the spacing of several sets of buffer oil passage holes changes with the extension of the piston rod, i.e., the relative position of the guide sleeve and the piston rod changes, which can control the opening and closing relationship of the oil passage holes on the piston rod. When the piston rod extends close to its limit position, only the last set of oil passage holes, i.e., the anti-jamming oil passage holes, can communicate with the rod chamber of the oil cylinder through the annular groove at the guide sleeve port, ensuring sufficient oil return and avoiding jamming and the oil cylinder not being able to fully extend or retract to its full position.

[0009] Furthermore, by adjusting the size, number, and spacing of the oil passage holes, the buffer response speed can be adjusted to meet the system design requirements. The opening form of the oil passage holes is not limited to circular holes, and their arrangement is also unrestricted. Preferably, each group of oil passage holes consists of several through holes distributed radially around the piston rod, transforming the oil passage holes into an ordered arrangement of holes to achieve controllable changes in the oil passage area.

[0010] Furthermore, the inner wall of the guide sleeve is provided with a wear-resistant guide ring that slides with the piston rod. In addition to conventional seals and dust rings, the guide sleeve has a wear-resistant guide ring arranged on the cylinder side near the port. The wear-resistant guide ring can be made of nylon or other materials with good wear resistance and deformation resistance.

[0011] Furthermore, a rear cover is provided; the inner wall of the cylinder is provided with an inner stop, and the outer wall of the guide sleeve is provided with a stepped surface that matches the inner stop; the rear cover is threadedly connected to the inner wall of the cylinder and presses tightly against the end face of the guide sleeve, so that the stepped surface of the outer wall of the guide sleeve and the inner stop mutually limit and fit each other, thus fixing the guide sleeve inside the cylinder for easy disassembly and assembly.

[0012] Furthermore, the piston rod head is provided with a first oil port and a second oil port. The first oil port, the piston rod cavity, the oil passage, and the rod chamber form an oil passage. A sealed core tube is built into the piston rod cavity. The second oil port, the sealed core tube, and the rodless chamber form an oil passage. Oil enters the piston rod cavity through the first oil port on the piston rod head, and then enters the rod chamber of the cylinder through the oil passage at the end of the piston rod. The oil path in and out of the rodless chamber of the cylinder is from the second oil port on the piston rod head to the sealed core tube built into the piston rod, directly connecting to the rodless chamber of the cylinder.

[0013] This utility model has a simple structure and does not require additional hydraulic valves; the buffer structure does not occupy the conventional layout space of the oil cylinder and does not affect the conventional layout of the oil cylinder, and the cylinder diameter, rod diameter, and stroke are not affected; the process is simple, with oil holes drilled on the piston rod, resulting in low processing cost, low processing accuracy requirements, no stringent clearance fit requirements, and good product consistency; during the development and verification stage, the oil holes of the piston rod can be adjusted without replacement or scrapping, resulting in a short adjustment cycle and low cost. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model (the hydraulic cylinder is in its fully retracted state).

[0015] Figure 2 This is a partial enlarged view of the present invention (the hydraulic cylinder is in the extended state);

[0016] Figure 3 This is a partial enlarged view of the present invention (piston rod extended to near its limit position).

[0017] In the diagram: 1. Gland, 2. Cylinder, 3. Guide sleeve, 4. Wear-resistant guide ring, 5. Piston rod, 6. Buffer oil passage, 7. Buffer oil passage, 8. Anti-jamming oil passage, 9. First oil port, 10. Second oil port, 11. Annular groove, 12. Sealed core tube. Detailed Implementation

[0018] A novel hydraulic cylinder built-in buffer mechanism includes a pressure cap 1, a cylinder barrel 2, a guide sleeve 3, a wear-resistant guide ring 4, and a piston rod 5. Figure 1 As shown, the gland 1 and cylinder 2 are connected by threads (the gland 1 is annular, fitted over the piston rod, and has external threads; the inner wall of the cylinder has internal threads). The guide sleeve 3 is pressed and fixed by the inner stop of the gland 1 and the inner wall of the cylinder. The piston rod is a hollow structure, and its side wall has several sets of oil passage holes. These oil passage holes are spaced apart along the piston rod axial direction and located at the end of the piston rod's stroke.

[0019] like Figure 1 As shown, the piston rod head is provided with a first oil port 9 and a second oil port 10. Oil enters the piston rod cavity through the first oil port on the piston rod head, and then enters the rod chamber of the cylinder through the oil passage at the end of the piston rod. The piston rod cavity contains a sealed core tube 12. The oil path in and out of the rodless chamber of the cylinder is from the second oil port on the piston rod head to the sealed core tube inside the piston rod, directly connecting to the rodless chamber of the cylinder.

[0020] In one embodiment of this utility model, such as Figure 1 , Figure 2 As shown, the oil passage consists of a first set of buffer oil passages 6, a second set of buffer oil passages 7, and a set of anti-jamming oil passages 8. The anti-jamming oil passages 8 are located on the outermost side and are close to the tail of the piston rod. Figure 1 In the fully retracted state of the hydraulic cylinder, when the cylinder extends to the end of its stroke, the first set of buffer oil passage holes 6 and the second set of buffer oil passage holes 7 on the cylinder piston rod are successively blocked by the guide sleeve of the cylinder barrel, reducing the oil passage area and slowing down the flow (e.g., Figure 2 (As shown).

[0021] In one embodiment of this utility model, the inner cavity wall of the guide sleeve has an annular groove 11 on one end face near the tail of the piston rod. For example... Figure 3 As shown, when the piston rod extends to near its limit position, only the last set of anti-jamming oil passages 8 can communicate with the rod chamber of the cylinder through the annular groove 11 of the guide sleeve port.

[0022] In one embodiment of this utility model, each group of oil passage holes consists of several through holes distributed radially around the piston rod, transforming the oil passage holes into an ordered arrangement of holes to achieve the purpose of controllable change in oil passage area.

[0023] In one embodiment of this utility model, the inner cavity wall of the guide sleeve is provided with a wear-resistant guide ring 4 that slides with the piston rod, and the wear-resistant guide ring is made of nylon.

Claims

1. A novel hydraulic cylinder built-in buffer mechanism, comprising a cylinder barrel and a piston rod, characterized in that, A guide sleeve is also provided, which is fixed to the port position of the inner wall of the cylinder and sleeved on the outside of the piston rod; the piston rod is a hollow structure, and the side wall of the piston rod is provided with several sets of oil passage holes, which are distributed at intervals along the piston rod axis and located at the end of the piston rod stroke.

2. The novel hydraulic cylinder built-in buffer mechanism according to claim 1, characterized in that, The oil passage consists of several sets of buffer oil passages and one set of anti-jamming oil passages. The anti-jamming oil passage is located on the outermost side and close to the tail of the piston rod.

3. A novel hydraulic cylinder built-in buffer mechanism according to claim 1 or 2, characterized in that, Each set of oil passages consists of several through holes distributed radially around the piston rod.

4. The novel hydraulic cylinder built-in buffer mechanism according to claim 1, characterized in that, The inner wall of the guide sleeve is provided with a wear-resistant guide ring that slides with the piston rod.

5. A novel hydraulic cylinder built-in buffer mechanism according to claim 3, characterized in that, The inner wall of the guide sleeve has an annular groove on one end face near the tail of the piston rod.

6. A novel hydraulic cylinder built-in buffer mechanism according to claim 5, characterized in that, It is also provided with a rear cover; the inner wall of the cylinder is provided with an inner stop, and the outer wall of the guide sleeve is provided with a stepped surface that matches the inner stop; the rear cover is threadedly connected to the inner wall of the cylinder and presses tightly against the end face of the guide sleeve.

7. The novel hydraulic cylinder built-in buffer mechanism according to claim 1, characterized in that, The piston rod has a first oil port at its rod head, and the first oil port, piston rod cavity, oil passage, and rod cavity form an oil passage.

8. The novel hydraulic cylinder built-in buffer mechanism according to claim 1, characterized in that, The piston rod has a second oil port at its rod head, and a sealed core tube is built into the cavity of the piston rod. The second oil port, the sealed core tube, and the rodless cavity form an oil passage.

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