Double-acting hydraulic stretcher

Abstract

The utility model discloses a double-acting hydraulic stretcher which comprises a hydraulic oil cylinder, a piston, a stretching oil inlet and outlet block and a resetting oil inlet and outlet block, wherein the piston is arranged in the hydraulic oil cylinder in a sliding manner; the stretching oil inlet and outlet block and the resetting oil inlet and outlet block are arranged on the hydraulic oil cylinder; the hydraulic cylinder is characterized in that a plurality of limiting holes are symmetrically formed in the piston; a limiting rod for limiting the piston is mounted in the limiting hole; and an auxiliary rod is movably mounted on the limiting rod. According to the utility model, one end of the limiting rod is inserted into the limiting hole of the piston to limit the piston, so that the piston is prevented from sliding downwards when oil leaks due to aging of a sealing element to damage the hydraulic stretcher, and the service life is prolonged; by means of the auxiliary rod, a worker can pull the limiting rod out of the limiting hole of the piston from the distance, and therefore the use safety of the worker is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic tensioners for bolt preloading, and specifically refers to a double-acting hydraulic tensioner. Background Art

[0002] A hydraulic tensioner is a special bolt preloading tool. The bolt preloading force can be simply understood as the clamping force exerted by the bolt on the connected parts along the axial direction of the bolt. The bolt preloading force is generated by stretching the screw rod within the elastic range. In the existing technology, after long-term use of the hydraulic tensioner, the sealing ring between the hydraulic cylinder body and the piston is prone to aging, resulting in oil leakage. The hydraulic oil in the cavity below the piston may flow into the cavity above the piston, reducing the pressure in the cavity below the piston and causing the piston to slide downward, which is likely to damage the hydraulic tensioner itself and reduce its service life. Therefore, a double-acting hydraulic tensioner is proposed to improve the use safety. Summary of the Invention

[0003] The purpose of the utility model is to propose a double-acting hydraulic tensioner to solve the above problems.

[0004] To achieve the above purpose, the utility model provides the following technical solution: A double-acting hydraulic tensioner, comprising a hydraulic cylinder, a piston slidably installed in the hydraulic cylinder, and a stretching oil inlet / outlet block and a reset oil inlet / outlet block installed on the hydraulic cylinder; characterized in that a number of limiting holes are symmetrically arranged on the piston; limiting rods for piston limiting are installed in the limiting holes; and auxiliary rods are movably installed on the limiting rods.

[0005] Preferably, the hydraulic cylinder comprises a cylinder body and a cylinder head installed on the cylinder body.

[0006] Preferably, the cylinder body is provided with positioning grooves for installing and positioning the stretching oil inlet / outlet block and the reset oil inlet / outlet block, and docking grooves for docking with the stretching oil inlet / outlet block and the reset oil inlet / outlet block.

[0007] Preferably, the stretching oil inlet / outlet block and the reset oil inlet / outlet block are provided with positioning bosses adapted to the positioning grooves and docking bosses adapted to the docking grooves.

[0008] Preferably, the docking bosses are further provided with docking oil grooves; and docking oil holes are provided in the docking grooves.

[0009] Preferably, sealing rings for sealing between the stretching oil inlet / outlet block and the reset oil inlet / outlet block and the cylinder body are installed in both the docking oil grooves and the docking grooves.

[0010] Preferably, both the stretching oil inlet / outlet block and the reset oil inlet / outlet block are provided with oil inlet / outlet channels and oil inlet / outlet connectors communicating with the oil inlet / outlet channels.

[0011] Preferably, sealing rings are also installed on both the cylinder head and the piston.

[0012] Advantages of the present utility model: One end of the limiting rod is inserted into the limiting hole of the piston to limit the piston, preventing the piston from sliding down when oil leakage occurs due to the aging of the sealing member, thus protecting the hydraulic tensioner from damage and increasing its service life.

[0013] By using the auxiliary rod, the staff can pull out the limiting rod from the limiting hole of the piston at a distance, thereby improving the safety of the staff during use. Description of the Drawings

[0014] Figure 1 is a schematic structural view of the present utility model.

[0015] Figure 2 is the present utility model Figure 1 is a partial enlarged view of part A in the present utility model.

[0016] Figure 3 is the present utility model Figure 1 is a partial enlarged view of part B in the present utility model.

[0017] Legend: 1, hydraulic cylinder; 101, cylinder block; 102, cylinder head; 103, positioning groove; 104, docking groove; 105, docking oil hole; 2, piston; 201, limiting hole; 3, stretching oil inlet and outlet block; 301, positioning boss; 302, docking boss; 303, docking oil groove; 304, oil inlet and outlet joint; 305, oil inlet and outlet channel; 4, reset oil inlet and outlet block; 5, limiting rod; 501, auxiliary rod; 6, sealing ring. Detailed Embodiments

[0018] Next, we will further explain a double-acting hydraulic tensioner of the present utility model with reference to the accompanying drawings.

[0019] It should be noted that all directional indications such as up, down, left, right, front, back... in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture as shown in the drawings. If this specific posture changes, the directional indications will also change accordingly.

[0020] Refer to the attached Figures 1-3As shown in the figure, a double-acting hydraulic tensioner in this embodiment includes a hydraulic cylinder 1, a piston 2 slidably installed in the hydraulic cylinder 1, and a stretching oil inlet / outlet block 3 and a reset oil inlet / outlet block 4 installed on the hydraulic cylinder 1. It is characterized in that a number of limiting holes 201 are symmetrically arranged on the piston 2; a limiting rod 5 for limiting the piston 2 is installed in the limiting holes 201; an auxiliary rod 501 is movably installed on the limiting rod 5. The piston 2 is limited by inserting one end of the limiting rod 5 into the limiting hole 201 of the piston 2, preventing the piston 2 from sliding down when the sealant ages and leaks oil, and causing damage to the hydraulic tensioner, thereby improving the service life. By using the auxiliary rod 501, the staff can pull out the limiting rod 5 from the limiting hole 201 of the piston 2 from a distance, thereby improving the safety of the staff during use.

[0021] Refer to the appendix Figures 1-3 As shown in the figure, the hydraulic cylinder 1 includes a cylinder block 101 and a cylinder head 102 installed on the cylinder block 101; sealing rings 6 are also installed on both the cylinder head 102 and the piston 2. The piston 2 and the cylinder block 101, and between the cylinder head 102 and the cylinder block 101 and the piston 2 are sealed by using the sealing rings 6.

[0022] Refer to the appendix Figures 1-3 As shown in the figure, the cylinder block 101 is provided with a positioning groove 103 for installing and positioning the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4, and a docking groove 104 for docking with the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4; the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 are provided with positioning bosses 301 adapted to the positioning groove 103 and docking bosses 302 adapted to the docking groove 104; a docking oil groove 303 is further provided on the docking boss 302; a docking oil hole 105 is provided in the docking groove 104; sealing rings 6 for sealing between the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 and the cylinder block 101 are installed in both the docking oil groove 303 and the docking groove 104; both the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 are provided with oil inlet / outlet channels 305 and oil inlet / outlet connectors 304 communicated with the oil inlet / outlet channels 305. The stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 are positioned and installed on the cylinder block 101 by installing the positioning bosses 301 and the docking bosses 302 on the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 into the positioning groove 103 and the docking groove 104 on the cylinder block 101, so as to facilitate the positioning and installation of the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4; the sealing rings 6 are installed in both the docking oil groove 303 and the docking groove 104 to double-seal between the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 and the cylinder block 101, thereby improving the sealing performance between the stretching oil inlet / outlet block 3 and the reset oil inlet / outlet block 4 and the cylinder block 101.

[0023] In the present utility model, when the sealing ring 6 between the piston 2 and the cylinder block 101 ages and causes oil leakage, the limiting rod 5 is inserted into the limiting holes 201 on both sides of the piston 2 to limit the piston 2, preventing the piston 2 from sliding downward due to the decrease in oil pressure below. When it can be used normally, the staff directly takes one end of the auxiliary rod 501 and pulls the auxiliary rod 501 outward. The auxiliary rod 501 drives the limiting rod 5 to move outward, canceling the limit on the piston 2 and improving the safety of the staff during use.

[0024] The above embodiments are illustrative of the present utility model and not restrictive thereof. Any scheme obtained by simply transforming the present utility model falls within the protection scope of the present utility model.

Claims

1. A double-acting hydraulic tensioner, comprising a hydraulic cylinder (1), a piston (2) slidably mounted in the hydraulic cylinder (1), and a stretching inlet and outlet oil block (3) and a reset inlet and outlet oil block (4) mounted on the hydraulic cylinder (1); wherein: A plurality of limiting holes (201) are symmetrically arranged on the piston (2); a limiting rod (5) for limiting the position of the piston (2) is installed in the limiting hole (201); and an auxiliary rod (501) is movably installed on the limiting rod (5).

2. A double-acting hydraulic tensioner according to claim 1, characterized in that: The hydraulic cylinder (1) comprises a cylinder body (101) and a cylinder head (102) mounted on the cylinder body (101).

3. A double-acting hydraulic tensioner according to claim 2, characterized in that: The cylinder body (101) is provided with a positioning groove (103) for installing and positioning the stretching oil inlet and outlet block (3) and the resetting oil inlet and outlet block (4), and a docking groove (104) for docking with the stretching oil inlet and outlet block (3) and the resetting oil inlet and outlet block (4).

4. A double-acting hydraulic tensioner according to claim 3, characterized in that: The stretching oil inlet and outlet block (3) and the resetting oil inlet and outlet block (4) are provided with a positioning boss (301) adapted to the positioning groove (103) and a docking boss (302) adapted to the docking groove (104).

5. A double-acting hydraulic tensioner according to claim 4, characterized in that: A docking oil groove (303) is also provided on the docking boss (302); and a docking oil hole (105) is provided in the docking groove (104).

6. A double-acting hydraulic tensioner according to claim 5, characterized in that: The docking oil groove (303) and the docking groove (104) are both provided with sealing rings (6) for sealing between the stretching inlet and outlet oil block (3) and the resetting inlet and outlet oil block (4) and the cylinder body (101).

7. A double-acting hydraulic tensioner according to claim 6, characterized in that: The stretching oil inlet and outlet block (3) and the resetting oil inlet and outlet block (4) are both provided with an oil inlet and outlet channel (305) and an oil inlet and outlet joint (304) communicating with the oil inlet and outlet channel (305).

8. A double-acting hydraulic tensioner according to claim 2, characterized in that: The cylinder cover (102) and the piston (2) are also both equipped with sealing rings (6).

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