CN220956255U - Leak detection structure of pneumatic-hydraulic cylinder - Google Patents

Abstract

The utility model discloses a leakage detection structure of a pneumatic-hydraulic cylinder, which comprises a cylinder body, wherein a piston is arranged in the cylinder body, a piston rod with the end part extending out of the cylinder body is connected to the piston, an air chamber and an oil chamber are correspondingly formed in the cylinder body at two sides of the piston respectively, an air seal piece is arranged between the piston and the cylinder body at one side close to the air chamber, an oil seal piece is arranged between the piston and the cylinder body at one side close to the oil chamber, a leakage detection cavity is arranged between the air seal piece and the oil seal piece, and a leakage detection opening communicated with the leakage detection cavity is formed in the piston rod. The advantages are that: the leakage detecting device has the advantages that the structure is simple and reasonable, the leakage detecting cavity is arranged between the air sealing piece and the oil sealing piece, and once the air sealing piece or the oil sealing piece fails, the fault condition can be conveniently observed from the leakage detecting port, so that the maintenance is timely carried out.

Description

A leak detection structure for a gas-liquid cylinder

Technical Field

The utility model relates to the technical field of gas-liquid cylinder manufacturing, in particular to a gas-liquid cylinder leakage detection structure.

Background technique

Air cylinders and hydraulic cylinders are both commonly used power components in mechanical equipment. Air cylinders convert air pressure energy into mechanical energy to guide the piston to make linear repetitive motion. Correspondingly, hydraulic cylinders convert hydraulic energy into mechanical energy to guide the piston to make linear repetitive motion. Air cylinders have the characteristics of fast response speed, but due to the compressibility of gas, their output pressure is lower than that of hydraulic cylinders; hydraulic cylinders can provide greater output pressure. Gas-liquid cylinders are a type of equipment that combines air cylinders and hydraulic cylinders.

There are air chambers and oil chambers in the gas-liquid cylinder. The air chamber needs to be sealed by an air seal, and the oil chamber needs to be sealed by an oil seal. Once the air seal or oil seal fails, it will cause the normal operation of the equipment. When there is a slight leak, the equipment can still work normally, but the equipment's work efficiency and work effect will decrease. When the leak is large, the equipment will not work normally. Because there are many reasons for the decline in the work efficiency and work effect of a piece of equipment, the decline in work efficiency and work effect does not clearly point to the leakage or failure of the air seal or oil seal. The operator needs to check the possible fault points one by one, which is troublesome and laborious. In addition, the air seal or oil seal is installed inside the equipment, and its assembly requirements are high, and disassembly is more troublesome. If the fault point can be found directly, it can greatly save manpower and material resources and improve production efficiency.

Utility Model Content

The purpose of the utility model is to make up for the above-mentioned deficiencies and disclose to the public a leak detection structure of a gas-liquid cylinder which has a simple and reasonable structure, is convenient for leak detection and can effectively detect leaks in a timely manner.

The technical solution of the utility model is achieved in this way:

A leak detection structure for a gas-liquid cylinder comprises a cylinder body, a piston is arranged in the cylinder body, a piston rod is connected to the piston and an end thereof extends out of the cylinder body, an air chamber and an oil chamber are formed in the cylinder body on both sides of the piston respectively, an air seal is arranged between the piston and the cylinder body on the side close to the air chamber, an oil seal is arranged between the piston and the cylinder body on the side close to the oil chamber, a leak detection cavity is arranged between the air seal and the oil seal, and a leak detection port communicating with the leak detection cavity is arranged on the piston rod.

The measures to further optimize this technical solution are:

As an improvement, the leak detection chamber is annular in structure. The leak detection chamber is annular in structure and is arranged on the outer wall of the piston, that is, the leak detection chamber is arranged in parallel with the gas seal and the oil seal. If any position of the gas seal or the oil seal fails, the corresponding gas or hydraulic oil can quickly enter the leak detection chamber and finally reach the leak detection port. Such an arrangement can improve the timeliness of leak detection.

As an improvement, a central cavity is provided in the middle of the piston, a first radial hole is provided on the piston, the outer end of the first radial hole is communicated with the leak detection cavity, and the inner end of the first radial hole is communicated with the central cavity. The leak detection cavity is communicated with the central cavity in the middle of the piston through the first radial hole provided on the piston. In other words, the gas and hydraulic oil entering the leak detection cavity will enter the central cavity through the first radial hole.

As an improvement, the center of the piston rod is provided with an axial hole, the head of the piston rod is provided with a second radial hole, the outer end of the second radial hole is communicated with the leak detection port, the inner end of the second radial hole is communicated with the axial hole, and the rear end of the axial hole extends to the end face of the piston rod and communicates with the central cavity of the piston. The central cavity is communicated with the leak detection port through the axial hole and the second radial hole. In other words, the gas and hydraulic oil entering the central cavity will pass through the axial hole and the second radial hole and finally flow to the leak detection port.

As an improvement, one end of the gas seal is provided with a gas seal expansion part, and the gas seal expansion part is arranged toward the air chamber. When the gas seal is fitted in the installation groove, the gas seal expansion part will extend out of the surface of the installation groove. When the piston is installed in the cylinder body, the gas seal expansion part is squeezed and enters the installation groove. Due to the elasticity of the gas seal expansion part itself, it has a tendency to expand outward, so that the gas seal is in close contact with the inner wall of the cylinder body to form a seal.

As an improvement, an oil seal expansion part is provided at one end of the oil seal, and the oil seal expansion part is arranged toward the oil chamber. Similarly, when the oil seal is fitted in the mounting groove, the oil seal expansion part will extend out of the surface of the mounting groove. When the piston is installed in the cylinder body, the oil seal expansion part is squeezed and enters the mounting groove. Due to the elasticity of the oil seal expansion part itself, it has a tendency to bulge outward, so that the oil seal is in close contact with the inner wall of the cylinder body to form a seal.

As an improvement, a guide ring is arranged between the piston and the cylinder body, between the gas seal and the oil seal. The arrangement of the guide ring can improve the flexibility and smoothness of the movement of the piston in the cylinder body.

As an improvement, the rear end of the piston rod is provided with a central boss, and the middle part of the piston is provided with an assembly cavity adapted to the central boss. By using the cooperation between the central boss and the assembly cavity, the piston rod and the piston can be pre-positioned before being fixed, and the coaxiality of the piston rod and the piston can be improved after being fixed.

As an improvement, a convex ring is fixed on the outer periphery of the piston near the oil chamber. The convex ring is arranged so that a cavity is formed inside the convex ring, and the cavity provides a front space for the hydraulic oil to be injected, so that the hydraulic oil can be injected smoothly.

As an improvement, the cylinder body comprises a cylinder body and a cylinder head fixed to each other, and a sealing ring is arranged between the cylinder body and the cylinder head. The arrangement of the sealing ring effectively improves the sealing performance between the cylinder body and the cylinder head.

The advantages of the utility model compared with the prior art are:

The utility model discloses a leak detection structure for a gas-liquid cylinder, which has a simple and reasonable structure. A leak detection cavity is arranged between the gas seal and the oil seal. Once the gas seal or the oil seal fails, the fault can be easily observed from the leak detection port, so that timely maintenance can be performed. Once the gas seal fails, the leak detection port will leak gas, and once the oil seal fails, the leak detection port will leak oil. By observing the leak or oil leakage at the leak detection port, it is very convenient to judge whether the gas seal or the oil seal fails, so that timely replacement can be performed, thereby ensuring the normal operation of the equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a partial cross-sectional perspective structural diagram of an embodiment of the utility model;

Fig. 2 is an enlarged view of part A in Fig. 1;

Fig. 3 is an enlarged view of part B in Fig. 1;

FIG4 is a cross-sectional view of an embodiment of the utility model;

FIG5 is an enlarged view of portion C in FIG4 ;

FIG. 6 is a three-dimensional structural diagram of the piston in FIG. 4 .

The names of the reference numerals in the accompanying drawings of the present utility model are:

Cylinder body 1, sealing ring 1a, air chamber 11, oil chamber 12, cylinder body 13, cylinder head 14, piston 2, leak detection chamber 2a, central chamber 2b, first radial hole 2c, assembly chamber 21, convex ring 22, piston rod 3, leak detection port 3a, axial hole 3b, second radial hole 3c, central boss 31, air seal 4, air seal expansion part 41, oil seal 5, oil seal expansion part 51, guide ring 6.

Detailed ways

The utility model is further described in detail below with reference to the accompanying drawings:

The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be used for other implementation schemes, variations, improvements, equivalent schemes, and other technical solutions that do not deviate from the spirit and scope of the utility model.

Those skilled in the art should understand that, in the disclosure of the present invention, the directions or positions indicated by the terms "longitudinal", "lateral", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, which are only simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the above terms should not be understood as limitations on the present invention.

It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

As shown in Figures 1 to 6, a leak detection structure of a gas-liquid cylinder includes a cylinder body 1, a piston 2 is arranged in the cylinder body 1, a piston rod 3 with an end extending out of the cylinder body 1 is connected to the piston 2, an air chamber 11 and an oil chamber 12 are formed on both sides of the piston 2 in the cylinder body 1 respectively, an air seal 4 is arranged between the piston 2 and the cylinder body 1 on the side close to the air chamber 11, an oil seal 5 is arranged between the piston 2 and the cylinder body 1 on the side close to the oil chamber 12, a leak detection cavity 2a is arranged between the air seal 4 and the oil seal 5, and a leak detection port 3a communicating with the leak detection cavity 2a is arranged on the piston rod 3.

The leak detection chamber 2a is an annular structure. The gas seal 4 and the oil seal 5 are annular structures. Here, the leak detection chamber 2a is an annular structure and is arranged on the outer wall of the piston 2. In other words, the leak detection chamber 2a is arranged in parallel with the gas seal 4 and the oil seal 5. With such an arrangement, as long as there is a leak at any point on the gas seal 4 and the oil seal 5, the corresponding gas and hydraulic oil will quickly enter the leak detection chamber 2a, and finally the connected cavity is reflected in the leak detection port 3a, which can effectively improve the timeliness of leak detection, so that the operator can find the leakage of the gas seal 4 or the oil seal 5 of the equipment as early as possible, so as to replace the gas seal 4 or the oil seal 5 in time.

As shown in FIG1 , a central cavity 2b is provided in the middle of the piston 2, and a first radial hole 2c is provided on the piston 2. The outer end of the first radial hole 2c is communicated with the leak detection cavity 2a, and the inner end of the first radial hole 2c is communicated with the central cavity 2b.

An axial hole 3b is provided at the center of the piston rod 3, and a second radial hole 3c is provided at the head of the piston rod 3. The outer end of the second radial hole 3c is communicated with the leak detection port 3a, and the inner end of the second radial hole 3c is communicated with the axial hole 3b. The rear end of the axial hole 3b extends to the end face of the piston rod 3 and is communicated with the central cavity 2b of the piston 2.

Here, a passage is established between the leak detection chamber 2a and the leak detection port 3a. The leak detection chamber 3a is connected to the central chamber 2b in the middle of the piston 2 through the first radial hole 2c provided on the piston 2, and the central chamber 2b is connected to the leak detection port 3a through the axial hole 3b and the second radial hole 3c. In other words, the gas and hydraulic oil entering the leak detection chamber 2a will enter the central chamber 2b through the first radial hole 2c, and then pass through the axial hole 3b and the second radial hole 3c, and finally flow to the leak detection port 3a. The leak detection port 3a is provided at the head of the piston rod 3 (except the end face of the cylinder head 14). During the reciprocating motion of the piston rod 3, the leak detection port 3a is always exposed to the outside, and the operator can easily observe the condition of the leak detection port 3a, thereby quickly judging whether the gas seal 4 and the oil seal 5 are leaking.

There is not only one way to establish a passage between the leak detection cavity 2a and the leak detection port 3a, as long as the leak detection cavity 2a and the leak detection port 3a can be connected.

As shown in FIG2 , one end of the gas seal 4 is provided with a gas seal expansion portion 41, and the gas seal expansion portion 41 is arranged toward the air chamber 11. In this embodiment, the cross section of the gas seal expansion portion 41 is a "human" shaped structure. In order to prevent the axial position of the gas seal 4 from moving during the reciprocating movement of the piston 2, an annular mounting groove is generally provided on the outer wall of the piston 2. The gas seal expansion portion 41 will extend out of the surface of the mounting groove when the gas seal 4 is embedded in the mounting groove. When the piston 2 is installed in the cylinder body 1, the gas seal expansion portion 41 is squeezed and enters the mounting groove. Due to the elasticity of the gas seal expansion portion 41 itself, it has a tendency to bulge outward, so that the gas seal 4 is in close contact with the inner wall of the cylinder body 1 to form a seal. Since the pressure on the air chamber side comes from the air pressure in the air chamber 11, the gas seal expansion portion 41 is arranged toward the air chamber 11. Of course, the gas seal expansion portion 41 can adopt other structures as long as the purpose of sealing can be achieved.

Since the pressure on the oil chamber side is relatively high, generally multiple oil seals 5 are provided on the piston 2. In this embodiment, two oil seals 5 are provided. As shown in FIG. 2 , an oil seal expansion portion 51 is provided at one end of the oil seal 5, and the oil seal expansion portion 51 is provided toward the oil chamber 12. In this embodiment, the cross section of the oil seal expansion portion 51 is also in a "human" shape. In order to prevent the axial position of the oil seal 5 from moving during the reciprocating movement of the piston 2, an annular mounting groove is also provided on the outer wall of the piston 2. When the oil seal 5 is embedded in the mounting groove, the oil seal expansion portion 51 will extend out of the surface of the mounting groove. When the piston 2 is installed in the cylinder body 1, the seal expansion portion 51 is squeezed and enters the mounting groove. Due to the elasticity of the oil seal expansion portion 51 itself, it has a tendency to bulge outward, so that the oil seal 5 is in close contact with the inner wall of the cylinder body 1 to form a seal. Since the pressure on the oil chamber side comes from the oil pressure in the oil chamber 12, the oil seal expansion portion 51 is provided toward the oil chamber 12. Of course, the oil seal expansion portion 51 may adopt other structures as long as the sealing purpose can be achieved.

A guide ring 6 is provided between the piston 2 and the cylinder body 1, between the gas seal 4 and the oil seal 5. The provision of the guide ring 6 can improve the flexibility and smoothness of the movement of the piston 2. As shown in FIG2 , in this embodiment, the guide ring 6 is provided between the gas seal 4 and the leak detection chamber 2a. With such a provision, the spatial layout is more reasonable, and the leak detection chamber 2a can be located in the middle of the piston 2. Of course, it is also possible to provide the guide ring 6 at other positions between the piston 2 and the cylinder body 1.

The rear end of the piston rod 3 is provided with a central boss 31, and the middle of the piston 2 is provided with an assembly cavity 21 adapted to the central boss 31. When the piston rod 3 and the piston 2 are assembled, the central boss 31 of the piston rod 3 is first inserted into the assembly cavity 21 of the piston 2, so that a pre-fixation can be formed, which facilitates the assembly between the two; then the two are fixed with bolts, and since the central boss 31 is plugged into the assembly cavity 21, the coaxiality between the piston rod 3 and the piston 2 can also be improved.

A convex ring 22 is fixed to the outer periphery of the piston 2 near the oil chamber 12. Due to the setting of the convex ring 22, a cavity is formed inside the convex ring 22, so that a gap is formed between the end face of the piston 2 and the oil inlet, which reserves space for the injection of hydraulic oil and allows the hydraulic oil to be injected smoothly. If this gap does not exist, due to the small diameter of the oil inlet, the hydraulic oil in the oil inlet directly acts on the end face of the piston 2, and a great pressure is required to push the piston 2 to move.

The cylinder body 1 includes a cylinder body 13 and a cylinder head 14 which are fixed to each other, and a sealing ring 1a is arranged between the cylinder body 13 and the cylinder head 14. The sealing ring 1a can improve the sealing performance between the cylinder body 13 and the cylinder head 14.

working principle:

Between the piston 2 and the cylinder body 1, an air seal 4 is arranged on the air chamber side to ensure the sealing of the air chamber side, and an oil seal 5 is arranged on the oil chamber side to ensure the sealing of the oil chamber side; on the piston 2, a leak detection cavity 2a is arranged between the air seal 4 and the oil seal 5.

Once the gas seal 4 fails, the gas in the air chamber 11 will enter the leak detection cavity 2a through the gas seal 4, and pass through the first radial hole 2c on the piston 2, the central cavity 2b of the piston 2, the axial hole 3b on the piston rod 3, and the second radial hole 3c on the piston rod 3, and finally flow to the leak detection port 3a. At this time, the operator can observe the leakage phenomenon at the leak detection port 3a. In other words, once the operator observes the leakage phenomenon at the leak detection port 3a, it means that the gas seal 4 has a leak and needs to be replaced.

Similarly, once the oil seal 5 fails, the hydraulic oil in the oil chamber 12 will enter the leak detection cavity 2a through the oil seal 5, and pass through the first radial hole 2c on the piston 2, the central cavity 2b of the piston 2, the axial hole 3b on the piston rod 3, and the second radial hole 3c on the piston rod 3, and finally flow to the leak detection port 3a. At this time, the operator can observe the oil leakage phenomenon at the leak detection port 3a. In other words, once the operator observes the oil leakage phenomenon at the leak detection port 3a, it means that the oil seal 5 has leaked and needs to be replaced.

In summary, the operator can easily determine whether the gas seal 4 or the oil seal 5 is ineffective by observing the gas leakage or oil leakage at the leak detection port 3a, so as to replace them in time to ensure the normal operation of the equipment.

Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments. Without departing from the principles, the embodiments of the present invention may be deformed or modified in any way.

Claims (10)

1. The utility model provides a leak hunting structure of pneumatic cylinder, including cylinder body (1), cylinder body (1) in be provided with piston (2), piston (2) on be connected with the tip and stretch out piston rod (3) of cylinder body (1), characterized by: the cylinder body (1) in be in both sides of piston (2) correspond respectively and be formed with air chamber (11) and grease chamber (12), piston (2) and cylinder body (1) between be provided with air seal (4) in being close to air chamber (11) one side, piston (2) and cylinder body (1) between be provided with oil blanket (5) in being close to grease chamber (12) one side, air seal (4) and oil blanket (5) between be provided with leak hunting chamber (2 a), piston rod (3) on be provided with leak hunting mouth (3 a) that leak hunting chamber (2 a) communicates with each other.

2. The leak detection structure of a pneumatic cylinder as defined in claim 1, wherein: the leak detection cavity (2 a) is of an annular structure.

3. The leak detection structure of a pneumatic cylinder as defined in claim 2, wherein: the middle part of piston (2) be provided with central chamber (2 b), piston (2) on be provided with first radial hole (2 c), the outer end of first radial hole (2 c) with leak hunting chamber (2 a) communicate with each other, the inner of first radial hole (2 c) with central chamber (2 b) communicate with each other.

4. A pneumatic-hydraulic cylinder leak detection structure as defined in claim 3, wherein: the center of the piston rod (3) is provided with an axial hole (3 b), the head of the piston rod (3) is provided with a second radial hole (3 c), the outer end of the second radial hole (3 c) is communicated with the leak detection port (3 a), the inner end of the second radial hole (3 c) is communicated with the axial hole (3 b), and the rear end of the axial hole (3 b) extends to the end face of the piston rod (3) and is communicated with the central cavity (2 b) of the piston (2).

5. The leak detection structure of a pneumatic cylinder as defined in claim 4, wherein: one end of the air seal (4) is provided with an air seal expansion part (41), and the air seal expansion part (41) is arranged towards the air chamber (11).

6. The leak detection structure of a pneumatic cylinder as defined in claim 4, wherein: one end of the oil seal (5) is provided with an oil seal expansion part (51), and the oil seal expansion part (51) is arranged towards the oil chamber (12).

7. A pneumatic cylinder leak detection structure as defined in claim 5 or 6, wherein: a guide ring (6) is arranged between the piston (2) and the cylinder body (1) and between the air sealing piece (4) and the oil sealing piece (5).

8. The leak detection structure of a pneumatic cylinder as defined in claim 7, wherein: the rear end of the piston rod (3) is provided with a central boss (31), and the middle part of the piston (2) is provided with an assembly cavity (21) matched with the central boss (31).

9. The leak detection structure of a pneumatic cylinder as defined in claim 8, wherein: a convex ring (22) is fixed on the periphery of one side, close to the oil chamber (12), of the piston (2).

10. The leak detection structure of a pneumatic cylinder as defined in claim 9, wherein: the cylinder body (1) comprises a cylinder body (13) and a cylinder cover (14) which are fixed mutually, and a sealing ring (1 a) is arranged between the cylinder body (13) and the cylinder cover (14).