A piston stroke limiting mechanism

Abstract

A piston stroke limit mechanism belongs to the technical field of stroke limit for piston overtravel of hydraulic fastening tools. The scheme is as follows: comprising: a plug A, a spring, a steel ball, a limit pin, and a limit module, wherein the plug A is arranged in the limit module, one end of the spring is connected to the plug A and the other end is connected to the steel ball, one end of the limit pin is connected to the steel ball and the other end is connected to the cylinder body. Beneficial effect: Since the piston stroke limit mechanism is externally arranged in the present invention, if the mechanism is damaged, it is only necessary to remove the mechanism and replace it with a new stroke limit mechanism, thereby avoiding disassembly of the cylinder. Save working time; since the piston stroke limit mechanism is externally arranged in the present invention, it will not have any impact on the seal, thereby ensuring the life of the seal.

Description

Technical Field

[0001] The present invention belongs to the technical field of stroke limit of the piston overstroke of hydraulic fastening tools, and particularly relates to a piston stroke limit mechanism. Background Art

[0002] Currently, the solutions for stroke limit of bolt stretchers used in hydraulic bolt fastening tools generally adopt several built-in solutions. Such stroke limits have the following problems:

[0003] The built-in piston stroke limit generally adds a stroke limit mechanism inside the cylinder block or slots the cylinder wall. Choosing to add a stroke limit inside the cylinder block requires repeated disassembly of the cylinder during debugging, which is rather cumbersome and may cause some unnecessary problems; choosing to slot the cylinder wall causes greater damage to the seal during long-term use, affecting the seal life. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention proposes a piston stroke limit mechanism. This mechanism externalizes the stroke limit mechanism, which is convenient for replacement, avoids cylinder disassembly, saves working time, and ensures the seal life.

[0005] The technical solution is as follows:

[0006] A piston stroke limit mechanism includes: plug A, spring, steel ball, limit pin, and limit module. The plug A is arranged in the limit module. One end of the spring is connected to the plug A, and the other end is connected to the steel ball. One end of the limit pin is connected to the steel ball, and the other end is connected to the cylinder block.

[0007] Furthermore, it also includes a plug B for sealing the oil passage, and the plug B is arranged below the limit module.

[0008] Furthermore, it also includes a combined gasket for sealing the connection between the limit module and the cylinder block, and the combined gasket is placed in the sealing groove of the limit module.

[0009] Furthermore, it also includes an internal hexagonal bolt, and the internal hexagonal bolt passes through the piston stroke limit mechanism and is fixed on the cylinder block.

[0010] Compared with the existing piston stroke limit, the piston stroke limit mechanism of the present invention has the following beneficial effects:

[0011] 1. Since the piston stroke limit mechanism of the present invention is externalized, if the mechanism is damaged, only this mechanism needs to be removed and a new stroke limit mechanism can be replaced, avoiding cylinder disassembly and saving working time.

[0012] 2. Since the piston stroke limiting mechanism of the present invention is externally placed, it will not have any impact on the seal and ensures the seal life. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of the internal structure of the present invention;

[0014] Figure 2 is an isometric view of the present invention;

[0015] The reference numerals in the drawings are as follows: 1 - plug, 2 - spring, 3 - steel ball, 4 - limit pin, 5 - limit module, 6 - plug, 7 - combined washer, 8 - hexagon socket head bolt, 9 - piston, 10 - cylinder block. DETAILED DESCRIPTION OF THE INVENTION

[0016] The following further describes the piston stroke limiting mechanism in conjunction with the attached Figure 1-2 drawings.

[0017] A piston stroke limiting mechanism includes: plug A1, spring 2, steel ball 3, limit pin 4, limit module 5. The plug A1 is arranged in the limit module 5. One end of the spring 2 is connected to the plug A1 and the other end is connected to the steel ball 3. One end of the limit pin 4 is connected to the steel ball 3 and the other end is connected to the piston 9.

[0018] Further, it also includes a plug B6 for sealing the oil passage, and the plug B6 is arranged below the limit module 5.

[0019] Further, it also includes a combined washer 7 for sealing the connection between the limit module and the cylinder block, and the combined washer 7 is placed in the sealing groove of the limit module 5.

[0020] Further, it also includes a hexagon socket head bolt 8, and the hexagon socket head bolt 8 passes through the piston stroke limiting mechanism and is fixed on the cylinder block 10.

[0021] The spring 2 in the limit module 5 makes the steel ball 3 fit with the conical surface. The conical surface refers to the surface on the side close to the cylinder block 10 in the hole where the spring 2 of the limit module 5 is located. The hydraulic oil in the oil cavity of the oil cylinder enters the limit module 5 through the oil passage. Under pressure, the steel ball 3 forms a seal with the conical surface. Both ends of the oil passage are sealed with plugs, and the connection between the limit module 5 and the cylinder block 10 is sealed with the combined washer 7, so that the whole piston stroke limiting mechanism forms a sealed state and does not affect the normal movement state of the piston.

[0022] When the piston moves beyond the predetermined stroke, the inclined surface on the surface of the piston 9 contacts the limit pin 4 in the piston stroke limiting mechanism and causes the limit pin 4 to continue moving to the left. When the limit pin 4 contacts the steel ball 3, the sealed state formed by the steel ball 3 and the conical surface is broken, and the hydraulic oil leaks from here. The oil pressure in the oil cavity drops instantly, warning that the piston 9 has reached the maximum stroke, avoiding cylinder explosion and seal damage due to excessive pressure beyond the stroke.

[0023] The assembly method of the present invention is as follows:

[0024] A. Place the steel ball 3 and the spring 2 in the hole of the limit module 5 in sequence. Use the plug A1 to compress the spring 2 so that the steel ball 3 fits with the conical surface. At the same time, the plug A1 seals the oil passage.

[0025] B. Seal the oil passage with the plug B6.

[0026] C. Place the combined washer 7 in the sealing groove of the limit module 5.

[0027] D. Place the limit pin 4 at the opening of the cylinder block.

[0028] E. Fix the piston stroke limiting mechanism on the cylinder block 10 with two socket head cap screws 8 (note that the limit pin 4 should be in the holes of the limit module 5 and the cylinder block 10 at the same time).

[0029] As mentioned above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A piston stroke limiting mechanism, characterized in that, Including: Plug A (1), spring (2), steel ball (3), limit pin (4), limit module (5). The plug A (1) is arranged in the limit module (5). One end of the spring (2) is connected to the plug A (1), and the other end is connected to the steel ball (3). One end of the limit pin (4) is connected to the steel ball (3), and the other end is connected to the cylinder block (10). It further includes a plug B (6) for sealing the oil passage, and the plug B (6) is arranged below the limit module (5). It also includes a combined washer (7) for sealing the connection between the limit module and the cylinder block, and the combined washer (7) is placed in the sealing groove of the limit module (5). It further includes an internal hexagon bolt (8), and the internal hexagon bolt (8) passes through the piston stroke limiting mechanism and is fixed on the cylinder block (10). The assembly steps are as follows: S1. Place the steel ball (3) and the spring (2) in the hole of the limit module (5) in sequence. Use the plug A (1) to compress the spring (2) so that the steel ball (3) fits with the conical surface. At the same time, the plug A (1) seals the oil passage. S2. Seal the oil passage with the plug B (6). S3. Place the combined washer (7) in the sealing groove of the limit module (5). S4. Place the limit pin (4) at the opening of the cylinder block. S5. Fix the piston stroke limiting mechanism on the cylinder block (10) with two internal hexagon bolts (8).

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