Hydraulic cylinder with built-in overflow function piston

Abstract

The utility model relates to a hydraulic cylinder with a built-in overflow function piston, and relates to the technical field of hydraulic cylinders. The hydraulic cylinder comprises a cylinder body, a piston connected with the cylinder body in a sliding mode, a piston rod connected with the piston, a guide sleeve connected with the cylinder body, an overflow assembly arranged in the piston, a first static seal arranged between the piston and the piston rod, and a second static seal arranged between the guide sleeve and the cylinder body. The first guide sealing mechanism is arranged between the piston and the cylinder body; the second guide sealing mechanism is arranged between the guide sleeve and the piston rod; the piston is provided with a valve hole and an overflow hole communicated with the valve hole, the end, away from the valve hole, of the overflow hole is an oil connector, and the overflow assembly is arranged in the valve hole. The hydraulic cylinder has the advantages that the pressure of the rod cavity is reduced, the phenomenon that the pressure of the rod cavity is too high is reduced, and therefore the service life of the hydraulic cylinder is prolonged.

Description

Technical Field

[0001] The present application relates to the field of hydraulic cylinder technology, and in particular to a hydraulic cylinder with a built-in overflow function piston. Background Art

[0002] The hydraulic cylinder is an actuator in the hydraulic system. It converts hydraulic energy into mechanical energy, usually performing linear reciprocating motion or swinging motion. It is also called an oil cylinder, which generally includes a cylinder body, a piston rod, a piston and a guide sleeve. The hydraulic cylinder has the advantages of simple structure, reliable operation, stable operation, long service life and low cost, so it is widely used in industries such as industry, metallurgy, engineering, civil and vehicles. Due to the wide application of hydraulic cylinders, the length of its service life has a great impact on the development of all walks of life. The most common failure forms of hydraulic cylinders include internal leakage, external leakage, piston shedding and guide sleeve shedding. The main cause of internal leakage is the failure of the seal at the piston part, the main cause of external leakage is the failure of the seal at the guide sleeve part, the main cause of piston shedding is the damage of the connection structure between the piston and the piston rod, and the main cause of guide sleeve shedding is the damage of the connection structure between the guide sleeve and the cylinder body.

[0003] Excessive rod chamber pressure may cause the cylinder diameter to expand, causing the gap between the cylinder and the piston seal to exceed the allowable seal gap and seal failure, or the dynamic seal or static seal of the piston to be subjected to pressure exceeding its design allowable value, resulting in seal failure. Excessive rod chamber pressure may also cause the cylinder diameter to expand, causing the gap between the cylinder and the guide sleeve static seal to exceed the allowable seal gap and seal failure, or the guide sleeve seal to be subjected to pressure exceeding its design allowable value, resulting in seal failure. Excessive rod chamber pressure may also cause the connection structure between the piston and the piston rod to loosen or even damage, or the connection structure between the guide sleeve and the cylinder to loosen or even damage. Since the effective area of ​​the rodless chamber is 1.5 times, 2 times or even more than ten times the effective area of ​​the rodless chamber, when the rodless chamber is pressurized, no matter what the reason for the blocked oil path in the rod chamber, the pressure in the rod chamber will increase sharply, thus exposing the hydraulic cylinder to the risk of failure.

[0004] With respect to the above-mentioned related technologies, the inventor believes that excessive pressure in the rod chamber may cause the hydraulic cylinder to fail, thereby reducing the service life of the hydraulic cylinder. Utility Model Content

[0005] In order to solve the above technical problems, the present application provides a hydraulic cylinder with a built-in overflow function piston.

[0006] The present application provides a hydraulic cylinder with a built-in overflow function piston, which adopts the following technical solution:

[0007] A hydraulic cylinder with a piston having an overflow function built in, comprising a cylinder body, a piston slidably connected to the cylinder body, a piston rod connected to the piston, a guide sleeve connected to the cylinder body, an overflow assembly arranged in the piston, a first static seal arranged between the piston and the piston rod, a second static seal arranged between the guide sleeve and the cylinder body, a first guide sealing mechanism arranged between the piston and the cylinder body, and a second guide sealing mechanism arranged between the guide sleeve and the piston rod; a valve hole and an overflow hole connected to the valve hole are provided on the piston, an end of the overflow hole away from the valve hole is an oil interface, and the overflow assembly is arranged in the valve hole.

[0008] By adopting the above technical solution, after the overflow assembly is assembled, a manual oil pump is connected to the oil interface to adjust the overflow pressure value of the overflow assembly. When the pressure value in the rod chamber is greater than the overflow pressure value, the overflow assembly is in an overflow state, and the oil in the rod chamber enters the rodless chamber through the overflow assembly, thereby achieving pressure relief in the rod chamber, thereby reducing the occurrence of hydraulic cylinder failure due to excessive pressure in the rod chamber, thereby increasing the service life of the hydraulic cylinder.

[0009] Preferably, the number of the valve holes is one or more, the number of the overflow assemblies is the same as the number of the valve holes, and the overflow assembly includes a valve plug, a spring and a valve core arranged in the valve hole, one end of the spring is connected to the valve plug, and the other end is connected to the valve core.

[0010] By adopting the above technical solution, the structure of the overflow component is simple, so that the assembly process of the overflow component is simple and convenient, and the processing cost is reduced.

[0011] Preferably, a first mounting groove is formed on the valve plug, a second mounting groove is formed on the valve core, one end of the spring is arranged in the first mounting groove, and the other end is arranged in the second mounting groove.

[0012] By adopting the above technical solution, the two ends of the spring are respectively located in the first installation groove and the second installation groove, which improves the connection stability between the spring and the valve plug and the valve core, and improves the stability of the spring expansion and contraction process, so that the overflow assembly operates stably and the pressure relief effect is good.

[0013] Preferably, a sealing cone is provided at one end of the valve core away from the spring, and the sealing cone is sealed with the overflow hole line.

[0014] By adopting the above technical solution, the sealing cone is sealed with the overflow hole line, so that the overflow component has good sealing performance and high sensitivity, thereby making the overflow component have a good overflow pressure relief effect.

[0015] Preferably, a first oil unloading hole is provided on the valve core, one end of the first oil unloading hole is communicated with the second mounting groove, and the other end is arranged on the inclined side surface of the blocking cone.

[0016] By adopting the above technical solution, after the valve core moves toward the valve plug, the oil in the rod chamber enters the second installation groove through the first oil unloading hole, thereby facilitating the oil in the rod chamber to enter the rodless chamber to complete pressure relief.

[0017] Preferably, the valve plug is threadably connected to the piston, a second oil unloading hole is provided on the valve plug, one end of the second oil unloading hole is communicated with the first mounting groove, and the other end is provided with a screwing portion.

[0018] By adopting the above technical solution, the position of the valve plug is adjusted by the screwing part, so as to adjust the overflow pressure value of the overflow component, thereby increasing the flexibility and adaptability of the overflow component.

[0019] Preferably, the first guide sealing mechanism comprises a hole guide ring and a hole main seal provided on the piston.

[0020] By adopting the above technical solution, the guide ring of the hole guides the movement of the piston, and the main seal of the hole improves the sealing between the piston and the cylinder body, so that the movement process of the piston is smooth and stable, thereby improving the stability of the working process of the hydraulic cylinder.

[0021] Preferably, the second guide sealing mechanism comprises a shaft guide ring, a shaft main seal, a dust seal and a buffer seal which are arranged on the guide sleeve.

[0022] By adopting the above technical solution, the shaft guide ring guides the movement of the piston rod, the shaft main seal increases the sealing between the piston rod and the guide sleeve, the buffer seal plays a buffering role, and the dust seal improves the dustproof effect of the hydraulic cylinder and thus increases the service life of the hydraulic cylinder.

[0023] In summary, this application has the following beneficial technical effects:

[0024] 1. The overflow assembly is used to relieve the pressure in the rod chamber, which reduces the occurrence of hydraulic cylinder failure caused by excessive pressure in the rod chamber, thereby increasing the service life of the hydraulic cylinder;

[0025] 2. The overflow assembly has a simple structure, which makes the assembly process of the overflow assembly simple and convenient and reduces the processing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a partial cross-sectional structure of a hydraulic cylinder with a built-in overflow function piston;

[0027] Figure 2 yes Figure 1 A magnified schematic diagram of part A;

[0028] Figure 3 yes Figure 1 A magnified schematic diagram of part B;

[0029] Figure 4 It is a schematic diagram of the cross-sectional structure of the second static seal and the second seal guide mechanism.

[0030] Description of reference numerals: 1, cylinder body; 11, first bushing; 12, first grease nipple; 13, rod chamber; 14, rodless chamber; 2, piston; 21, valve hole; 22, overflow hole; 23, oil interface; 3, piston rod; 31, second bushing; 32, second grease nipple; 4, guide sleeve; 5, overflow assembly; 51, valve plug; 511, first mounting groove; 512, second oil discharge hole; 513, screwing part; 52, spring; 53, valve core; 531 , second mounting groove; 532, sealing cone; 533, first oil unloading hole; 6, first static seal; 61, first O-ring; 62, first O-ring retaining ring; 7, second static seal; 71, second O-ring; 72, second O-ring retaining ring; 8, first guide sealing mechanism; 81, guide ring for hole; 82, main seal for hole; 9, second guide sealing mechanism; 91, guide ring for shaft; 92, main seal for shaft; 93, dust seal; 94, buffer seal. DETAILED DESCRIPTION

[0031] The following is combined with Figure 1-4 This application is described in further detail.

[0032] The embodiment of the present application discloses a hydraulic cylinder with a built-in overflow function piston.

[0033] Reference Figure 1 , Figure 2 and Figure 3 A hydraulic cylinder with a built-in overflow piston includes a cylinder body 1, a piston 2 slidably connected to the cylinder body 1, a piston rod 3 connected to the piston 2 through a set bolt, a guide sleeve 4 fixedly connected to the cylinder body 1, an overflow assembly 5 arranged in the piston 2, a first static seal 6 arranged between the piston 2 and the piston rod 3, a second static seal 7 arranged between the guide sleeve 4 and the cylinder body 1, a first guide sealing mechanism 8 arranged between the piston 2 and the cylinder body 1, and a second guide sealing mechanism 9 arranged between the guide sleeve 4 and the piston rod 3. The piston 2 is provided with a valve hole 21 and an overflow hole 22 connected to the valve hole 21, and the end of the overflow hole 22 away from the valve hole 21 is an oil interface 23, and the overflow assembly 5 is arranged in the valve hole 21.

[0034] A first bushing 11 and a first grease nipple 12 are fixedly provided on the cylinder body 1 , and a second bushing 31 and a second grease nipple 32 are fixedly provided on the end of the piston rod 3 away from the piston 2 .

[0035] There are two valve holes 21 , and the number of overflow assemblies 5 is the same as the number of valve holes 21 . The overflow assembly 5 includes a valve plug 51 , a spring 52 and a valve core 53 arranged in the valve hole 21 . One end of the spring 52 is fixedly connected to the valve plug 51 , and the other end is fixedly connected to the valve core 53 .

[0036] A first mounting groove 511 is defined on the valve plug 51 , a second mounting groove 531 is defined on the valve core 53 , one end of the spring 52 is disposed in the first mounting groove 511 , and the other end of the spring 52 is disposed in the second mounting groove 531 .

[0037] The end of the valve core 53 away from the spring 52 is provided with a blocking truncated cone 532, and the blocking truncated cone 532 is linearly sealed with the overflow hole 22. The angle of the inclined side surface of the blocking truncated cone 532 is 90°.

[0038] The valve core 53 is provided with a first oil unloading hole 533, one end of which is connected to the second mounting groove 531, and the other end is arranged on the inclined side of the blocking truncated cone 532. There are four first oil unloading holes 533, which are arranged in a circular array.

[0039] The valve plug 51 is threadedly connected to the piston 2 . A second oil unloading hole 512 is formed on the valve plug 51 . One end of the second oil unloading hole 512 is communicated with the first mounting groove 511 , and a screwing portion 513 is provided at the other end.

[0040] The first static seal 6 includes a first O-ring 61 and a first O-ring retainer 62. The first guide seal mechanism 8 includes a hole guide ring 81 and a hole main seal 82 provided on the piston 2.

[0041] Reference Figure 4 The second static seal 7 includes a second O-ring 71 and a second O-ring retaining ring 72. The second guide seal mechanism 9 includes a shaft guide ring 91, a shaft main seal 92, a dust seal 93 and a buffer seal 94 arranged on the guide sleeve 4.

[0042] The implementation principle of the hydraulic cylinder with a built-in overflow function piston in the embodiment of the present application is as follows: after the overflow component 5 is assembled, a manual pump is connected to each oil interface 23 in turn, and the overflow pressure value P of the overflow component 5 is adjusted by rotating the valve plug 51. 0 During the use of the hydraulic cylinder, the pressure value in the rodless chamber 14 is P 1 , the pressure value in the rod chamber 13 is P 2 , when the rod chamber 13 is in the oil passage unobstructed state, P 2 ≤P 0 , the overflow assembly 5 is in a non-overflow state, and the elastic force of the spring 52 causes the sealing cone 532 on the valve core 53 to be linearly sealed with the overflow hole 22 on the piston 2.2 >P 0 , the valve core 53 overcomes the elastic force of the spring 52 and moves toward the valve plug 51, and the oil in the rod chamber 13 flows into the rodless chamber 14 through the first oil unloading hole 533 on the valve core 53 and the second oil unloading hole 512 on the valve plug 51, so that the pressure value P in the rod chamber 13 is 2 Gradually decrease until the rod chamber 13 pressure P 2 ≤P 0 When the valve core 53 is moved away from the valve plug 51 by the elastic force of the spring 52 , the sealing cone 532 is linearly sealed with the overflow hole 22 .

[0043] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A hydraulic cylinder with a built-in overflow piston, characterized in that: The invention comprises a cylinder body (1), a piston (2) slidably connected to the cylinder body (1), a piston rod (3) connected to the piston (2), a guide sleeve (4) connected to the cylinder body (1), an overflow assembly (5) arranged in the piston (2), a first static seal (6) arranged between the piston (2) and the piston rod (3), a second static seal (7) arranged between the guide sleeve (4) and the cylinder body (1), a first guide sealing mechanism (8) arranged between the piston (2) and the cylinder body (1), and a second guide sealing mechanism (9) arranged between the guide sleeve (4) and the piston rod (3); the piston (2) is provided with a valve hole (21) and an overflow hole (22) connected to the valve hole (21); an end of the overflow hole (22) away from the valve hole (21) is an oil interface (23); and the overflow assembly (5) is arranged in the valve hole (21).

2. A hydraulic cylinder with a built-in overflow piston according to claim 1, characterized in that: The number of the valve holes (21) is one or more, the number of the overflow components (5) is the same as the number of the valve holes (21), the overflow component (5) comprises a valve plug (51) arranged in the valve hole (21), a spring (52) and a valve core (53), one end of the spring (52) is connected to the valve plug (51), and the other end is connected to the valve core (53).

3. A hydraulic cylinder with a built-in overflow piston according to claim 2, characterized in that: The valve plug (51) is provided with a first mounting groove (511), the valve core (53) is provided with a second mounting groove (531), one end of the spring (52) is arranged in the first mounting groove (511), and the other end is arranged in the second mounting groove (531).

4. The hydraulic cylinder with a built-in overflow piston according to claim 3, characterized in that: A sealing truncated cone (532) is provided at one end of the valve core (53) away from the spring (52), and the sealing truncated cone (532) is linearly sealed with the overflow hole (22).

5. The hydraulic cylinder with a built-in overflow piston according to claim 4, characterized in that: The valve core (53) is provided with a first oil unloading hole (533), one end of the first oil unloading hole (533) is communicated with the second mounting groove (531), and the other end is arranged on the inclined side surface of the blocking truncated cone (532).

6. The hydraulic cylinder with a built-in overflow piston according to claim 5, characterized in that: The valve plug (51) is threadedly connected to the piston (2); a second oil unloading hole (512) is provided on the valve plug (51); one end of the second oil unloading hole (512) is communicated with the first mounting groove (511); and the other end is provided with a screwing portion (513).

7. The hydraulic cylinder with a built-in overflow piston according to claim 6, characterized in that: The first guide sealing mechanism (8) comprises a hole guide ring (81) and a hole main seal (82) arranged on the piston (2).

8. The hydraulic cylinder with a built-in overflow piston according to claim 7, characterized in that: The second guide sealing mechanism (9) comprises a shaft guide ring (91) arranged on the guide sleeve (4), a shaft main seal (92), a dust seal (93) and a buffer seal (94).

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