Hydraulic lifting cylinder

Abstract

The utility model relates to a hydraulic lifting cylinder, including cylinder, cylinder cover, piston and piston rod, cylinder cover is fixed on one end of cylinder and seals, the axial one end of piston is fixed in piston rod, and when piston rod drops to the bottom, piston and the inner bottom of cylinder abut, the axial other end of piston rod is located on cylinder cover, and the radial wall of piston and the radial wall of piston rod all are equipped with buffer hole unit, and when piston rod rises to the top, buffer hole unit is located in the inner wall side of cylinder cover and is covered by the inner wall of cylinder cover, the utility model discloses buffer hole unit is equipped on piston and piston rod, and when piston rod rises to the top, buffer hole unit is covered by the inner wall of cylinder cover, so that the lifting speed of piston rod has obtained the second deceleration, can reduce the impact, thereby reduce the vibration and the collision sound.

Description

Technical Field

[0001] This utility model belongs to the field of hydraulic cylinder technology, and in particular relates to a hydraulic lifting cylinder. Background Technology

[0002] A hydraulic lifting cylinder, also known as a hydraulic cylinder, is a device that converts hydraulic energy into mechanical energy. It typically consists of a piston, cylinder barrel, seals, and a hydraulic control valve. The working principle of a hydraulic lifting cylinder mainly relies on a hydraulic pump pressurizing hydraulic fluid. A solenoid valve opens the passage to the hydraulic cylinder and closes the return passage. The pressurized fluid drives the plunger in the hydraulic cylinder to rise. When descending, the solenoid valve closes the passage to the hydraulic cylinder and opens the return passage, allowing the fluid in the hydraulic cylinder to return to the oil tank, and the plunger retracts. In this process, the seals of the hydraulic cylinder play a crucial role in ensuring no fluid leakage, thus guaranteeing the normal operation of the hydraulic cylinder. However, existing hydraulic lifting cylinders, such as those with... Figure 1 , 2 As shown, the buffer hole is located on the radial wall of the piston. When the piston rod reaches the bottom of its upward stroke, the buffer hole 7 is not covered (there is a gap between the buffer hole 7 and the inner wall of the cylinder). This causes the cylinder to enter the buffer state, resulting in a sudden decrease in speed, significant vibration, and a knocking sound. In addition, to save costs, a pad 8 is installed at the bottom of the cylinder without changing the piston rod stroke, reducing the support length of the cylinder head. As a result, when the piston rod reaches the bottom of its upward stroke, the cylinder head's support length is insufficient, and the piston rod will experience slight axial bending under the action of lateral force. Furthermore, due to the reduced length of the cylinder head, the vent hole can only be located on the cylinder wall for overall hole arrangement considerations. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a hydraulic lifting cylinder that reduces vibration and collision noise and ensures that the piston does not bend axially.

[0004] The purpose of this utility model is achieved through the following technical solution: the hydraulic lifting cylinder includes a cylinder barrel, a cylinder head, a piston, and a piston rod; the cylinder head is fixed to one end of the cylinder barrel and sealed; the piston is fixed to one axial end of the piston rod, and when the piston rod descends to the bottom, the piston abuts against the inner bottom of the cylinder barrel; the other axial end of the piston rod is located on the cylinder head; buffer hole units are provided on both the radial wall of the piston and the radial wall of the piston rod; and when the piston rod rises to the top, the buffer hole units are located on the inner wall side of the cylinder head and are covered by the inner wall of the cylinder head.

[0005] The beneficial effects of this utility model are as follows: Compared with the prior art, by providing buffer hole units on the piston and piston rod, and when the piston rod rises to the top, the buffer hole units are covered by the inner wall of the cylinder head, which reduces the lifting speed of the piston rod for the second time, thereby reducing impact and vibration and collision noise; and when the piston rod descends to the bottom, the piston and the inner bottom of the cylinder directly abut against each other, which increases the support length of the cylinder head while ensuring that the piston rod stroke remains unchanged, and increases the contact surface between the piston rod and the cylinder head and cylinder, ensuring that the piston rod will not bend under the action of lateral force.

[0006] Preferably, the cylinder head has a vent hole on its radial wall. When the piston rod rises to the top, the vent hole contacts the outer circumferential wall of the piston rod. By setting the vent hole on the cylinder head, the length of the cylinder head is greatly increased compared with the prior art, while ensuring that the length of the entire hydraulic lifting cylinder remains unchanged. This increases the contact area between the piston rod and the cylinder head and cylinder barrel.

[0007] Preferably, the buffer hole unit includes a first buffer hole and a second buffer hole. The first buffer hole is disposed on the radial wall of the piston, and the second buffer hole is disposed on the radial wall of the piston rod. During the installation and fixing of the piston and the piston rod, the first buffer hole and the second buffer hole are aligned. The above structure not only facilitates the processing of the buffer hole, but also facilitates assembly and the effect of being covered by the inner wall of the cylinder head.

[0008] Preferably, the diameter of the second buffer hole is larger than that of the first buffer hole; this facilitates oil pressure buffering between the two buffer holes.

[0009] Preferably, both the first buffer hole and the second buffer hole have threaded holes on their walls, and the first buffer hole and the second buffer hole are fixed together by screws; this effectively fixes the two buffer holes together and further strengthens the fixation between the piston and the piston rod.

[0010] Preferably, the axial center of the screw pin is provided with a through hole, which is connected to both the first buffer hole and the second buffer hole. By providing the through hole, it is more conducive to the oil pressure buffer between the two buffer holes, and further reduces vibration and collision noise. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the existing hydraulic lifting cylinder main structure. Figure 1 .

[0012] Figure 2 This is a schematic diagram of the existing hydraulic lifting cylinder main structure. Figure 2 .

[0013] Figure 3 This is a schematic diagram of the main structure of the hydraulic lifting cylinder of this utility model. Figure 1 .

[0014] Figure 4 This is a schematic diagram of the main structure of the hydraulic lifting cylinder of this utility model. Figure 2 .

[0015] Figure 5 yes Figure 3 A magnified structural diagram at point A.

[0016] The labels in the attached diagram are as follows: 1. Cylinder; 2. Cylinder head; 3. Piston; 4. Piston rod; 5. Buffer hole unit; 6. Screw pin; 7. Buffer hole; 8. Spacer block; 21. Vent hole; 51. First buffer hole; 52. Second buffer hole; 61. Through hole. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings: as shown in the drawings Figures 3 to 5 As shown, this utility model includes a cylinder 1, a cylinder head 2, a piston 3, and a piston rod 4. The cylinder head 2 is fixed to one end of the cylinder 1 and sealed. The piston 3 is fixed to one axial end of the piston rod 4, and when the piston rod 4 descends to the bottom, the piston 3 abuts against the inner bottom of the cylinder 1. The other axial end of the piston rod 4 is located on the cylinder head 2. Buffer hole units 5 are provided on the radial walls of both the piston 3 and the piston rod 4. When the piston rod 4 rises to the top, the buffer hole units 5 are located on the inner wall side of the cylinder head 2 and are covered by the inner wall of the cylinder head 2. The specific process is as follows: During the rising process of the piston rod 4, the buffer hole units 5 achieve the first deceleration buffer between the piston 3 and the inner wall of the cylinder 1 when the piston rod 4 is almost at the bottom of its stroke. When the buffer hole units 5 enter the cylinder head 2, the buffer hole units 5 are covered, and the piston 3 achieves the second deceleration buffer. This reduces vibration and collision noise. Compared with the prior art, the existing hydraulic lifting cylinder can only achieve one deceleration buffer, and the speed will decrease sharply.

[0018] The cylinder head 2 has a vent hole 21 on its radial wall. When the piston rod 4 rises to the top, the vent hole 21 contacts the outer circumferential wall of the piston rod 4.

[0019] The buffer hole unit 5 includes a first buffer hole 51 and a second buffer hole 52. The first buffer hole 51 is disposed on the radial wall of the piston 3, and the second buffer hole 52 is disposed on the radial wall of the piston rod 4. During the installation and fixing of the piston 3 and the piston rod 4, the first buffer hole 51 and the second buffer hole 52 are aligned.

[0020] The diameter of the second buffer hole 52 is larger than the diameter of the first buffer hole 51.

[0021] Both the first buffer hole 51 and the second buffer hole 52 have threaded holes on their walls, and the first buffer hole 51 and the second buffer hole 52 are fixed together by screw pins 6.

[0022] The axial center of the screw pin 6 is provided with a through hole 61, which is connected to the first buffer hole 51 and the second buffer hole 52.

[0023] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A hydraulic lifting cylinder, comprising a cylinder barrel (1), a cylinder head (2), a piston (3), and a piston rod (4); characterized in that: The cylinder head (2) is fixed to one end of the cylinder (1) and sealed. The piston (3) is fixed to one axial end of the piston rod (4). When the piston rod (4) descends to the bottom, the piston (3) abuts against the inner bottom of the cylinder (1). The other axial end of the piston rod (4) is located on the cylinder head (2). Both the radial wall of the piston (3) and the radial wall of the piston rod (4) are provided with buffer hole units (5). When the piston rod (4) rises to the top, the buffer hole units (5) are located on the inner wall side of the cylinder head (2) and are covered by the inner wall of the cylinder head (2).

2. The hydraulic lifting cylinder according to claim 1, characterized in that: The cylinder head (2) has a vent hole (21) on its radial wall. When the piston rod (4) rises to the top, the vent hole (21) contacts the outer circumferential wall of the piston rod (4).

3. The hydraulic lifting cylinder according to claim 1, characterized in that: The buffer hole unit (5) includes a first buffer hole (51) and a second buffer hole (52). The first buffer hole (51) is disposed on the radial wall of the piston (3), and the second buffer hole (52) is disposed on the radial wall of the piston rod (4). During the installation and fixing of the piston (3) and the piston rod (4), the first buffer hole (51) and the second buffer hole (52) are aligned.

4. The hydraulic lifting cylinder according to claim 3, characterized in that: The diameter of the second buffer hole (52) is larger than the diameter of the first buffer hole (51).

5. The hydraulic lifting cylinder according to claim 3, characterized in that: Both the first buffer hole (51) and the second buffer hole (52) have threaded holes on their walls, and the first buffer hole (51) and the second buffer hole (52) are tightened and fixed together by a screw (6).

6. The hydraulic lifting cylinder according to claim 5, characterized in that: The screw pin (6) has a through hole (61) at its axial center, and the through hole (61) is connected to the first buffer hole (51) and the second buffer hole (52).

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