Circulation diaphragm valve

Abstract

The utility model discloses a circulation diaphragm valve which comprises a main body, a first channel, a second channel, a valve port, a diaphragm and an opening and closing driving mechanism, the first channel, the second channel, the valve port, the diaphragm and the opening and closing driving mechanism are arranged on the main body, the first channel and the second channel are communicated through the valve port, a containing cavity is formed in the position, opposite to the valve port, of the main body, the diaphragm comprises a core part and a deformation part, and the opening and closing driving mechanism is connected with the core part. The opening and closing driving mechanism is used for driving the core part to move in the axial direction of the containing cavity so as to open and close the valve port, the deformation part is connected with the core part and the side wall of the containing cavity and comprises a first deformation section and a second deformation section which alternately arch towards the interior of the containing cavity when the core part opens and closes the valve port, and an annular gradual change face is formed between the core part and the opening and closing driving mechanism. The circulation diaphragm valve has the advantages that the weight, the size and the occupied space of the opening and closing driving mechanism can be reduced, and the like.

Description

Technical Field

[0001] This utility model relates to the field of food and pharmaceutical packaging machinery and equipment technology, specifically to a circulating diaphragm valve. Background Technology

[0002] Chinese patent document CN202323409170.9 discloses a diaphragm valve device, specifically comprising a main body and a first channel, a second channel, and a valve port disposed on the main body. The first channel and the second channel are connected through the valve port. The main body has a diaphragm for opening and closing the valve port and an opening / closing drive mechanism for driving the diaphragm to open and close. The opening / closing drive mechanism includes a push-pull rod, a lever, and an opening / closing drive assembly disposed on the main body. One end of the lever is oscillatingly connected to the main body, the other end is oscillatingly connected to the drive end of the opening / closing drive assembly, and the middle is connected to the diaphragm through the push-pull rod. When closed, the opening / closing drive assembly drives the lever to swing forward, causing the push-pull rod to move towards the valve port, so that the diaphragm adheres to the outer end face of the valve port, thereby cutting off the first channel and the second channel from each other, achieving closure. When open, the opening / closing drive assembly drives the lever to swing in the opposite direction, causing the push-pull rod to move away from the valve port, so that the diaphragm separates from the outer end face of the valve port, thereby connecting the first channel and the second channel to each other, achieving opening. The diaphragm valve device has the following shortcomings: when the diaphragm closes the valve port, most of it is still in a suspended state in the second channel. During the downward pressing process of the drive mechanism, the diaphragm is subjected to a large counter-push force from the second channel, so a drive mechanism with a large downward thrust needs to be selected. Correspondingly, the weight and volume of the drive mechanism also need to be made larger, that is, it occupies a large space and is heavy. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a circulating diaphragm valve that can reduce the weight, volume and space occupied by the opening and closing drive mechanism.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] A circulating diaphragm valve includes a main body and a first channel, a second channel, a valve port, a diaphragm, and an opening / closing drive mechanism disposed on the main body. The first channel and the second channel are connected through the valve port. The main body has a receiving cavity at a position relative to the valve port. The diaphragm includes a core and a deformable portion. The opening / closing drive mechanism is connected to the core and is used to drive the core to move axially along the receiving cavity to open and close the valve port. The deformable portion connects the core and the side wall of the receiving cavity. The deformable portion includes a first deformable section and a second deformable section that alternately arch into the receiving cavity when the core opens and closes the valve port. An annular gradient surface is formed between the core and the opening / closing drive mechanism.

[0006] As a further improvement to the above technical solution:

[0007] The annular gradient surface is formed on the outer periphery of the core and is arranged axially with the deformable part in the receiving cavity. The annular gradient surface and the deformable part form a deformable cavity that communicates with the second channel.

[0008] The annular gradient surface is a conical surface that is smaller at the top and larger at the bottom.

[0009] The core is smaller than the cavity.

[0010] The core, the receiving cavity, and the valve port are coaxial, and the inner surface of the receiving cavity is a cylindrical surface.

[0011] The outer periphery of the deformable part is provided with a peripheral portion, which is fitted and connected to the outer end face of the receiving cavity.

[0012] The core, deformable part, and peripheral part are integrally formed.

[0013] The opening and closing drive mechanism includes a push-pull rod and an opening and closing drive assembly disposed on the main body. One end of the push-pull rod is connected to the core through a connector, and the other end is connected to the opening and closing drive assembly.

[0014] The connector is coaxially connected to the core, and the outer diameter of the connector is smaller than that of the core.

[0015] The push-pull rod is slidably mounted on the main body and is coaxial with the receiving cavity.

[0016] Compared with the prior art, the advantages of this utility model are:

[0017] In this invention, when the diaphragm core closes the valve port under the driving action of the opening and closing drive mechanism, only the first deformed section or the portion with an additional second deformed section that arches into the receiving cavity is in a suspended state in the second channel. At this time (when the core closes the valve port), the air pressure in the second channel acts in both directions along the driving direction of the opening and closing drive mechanism on the first deformed section and the annular gradient surface. That is, the first deformed section and the annular gradient surface can offset part or all of the pressure (air pressure and / or hydraulic pressure) in the second channel against the counter-thrust force of the opening and closing drive mechanism, thereby reducing the thrust of the opening and closing drive mechanism on the core. Furthermore, during the process of the drive core of the opening and closing drive mechanism moving from the open valve position to the closed valve position, only the arched portion of the deformable part or the connection portion between the external deformable part and the edge of the arched portion is in a suspended state in the second channel. Similarly, the air pressure in the second channel acts in both directions along the driving direction of the opening and closing drive mechanism on the arched portion of the deformable part and the annular gradient surface. That is, the arched portion of the deformable part and the annular gradient surface can offset part or all of the counter-thrust force of the pressure in the second channel on the opening and closing drive mechanism, thereby reducing the driving force of the opening and closing drive mechanism on the core. In other words, the counter-thrust force of the pressure in the second channel on the opening and closing drive mechanism is reduced during the process of driving the core to close the valve and in the state of closing the valve. Accordingly, a lower power opening and closing drive mechanism can be selected, which can reduce the weight, volume and space occupied by the opening and closing drive mechanism.

[0018] In the circulating diaphragm valve of this invention, when the valve port is open, the core can be located in the receiving cavity. At this time, the core has a partial blocking effect on the opening end of the receiving cavity facing the valve port, which can be regarded as closing the deformable part in the receiving cavity, reducing the impact of the liquid flow between the first channel and the second channel on the deformable part, thereby helping to improve the service life of the diaphragm. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the circulating diaphragm valve of this utility model when the valve port is open.

[0020] Figure 2 This is a schematic diagram of the circulating diaphragm valve of this utility model when the valve port is closed.

[0021] Figure 3 This is a schematic diagram of another embodiment of the circulating diaphragm valve of this utility model when the valve port is open.

[0022] Figure 4 This is a schematic diagram of another embodiment of the circulating diaphragm valve of this utility model when the valve port is closed.

[0023] The labels in the diagram represent:

[0024] 1. Main body; 2. First channel; 3. Second channel; 4. Valve port; 5. Diaphragm; 51. Core; 52. Deformable part; 521. First deformable section; 522. Second deformable section; 53. Peripheral part; 6. Opening and closing drive mechanism; 61. Push-pull rod; 62. Opening and closing drive assembly; 63. Connector; 621. Cylinder; 622. Piston; 623. Elastic element; 7. Receiving cavity; 71. Outer end face; 8. Annular gradient surface; 9. Deformable cavity. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] Example 1:

[0030] Figure 1 and Figure 2An embodiment of the circulating diaphragm valve of this utility model is shown. The circulating diaphragm valve of this embodiment includes a main body 1 and a first channel 2, a second channel 3, a valve port 4, a diaphragm 5 and an opening and closing drive mechanism 6 disposed on the main body 1. The first channel 2 and the second channel 3 are connected through the valve port 4. A receiving cavity 7 is provided on the main body 1 at a position relative to the valve port 4. The diaphragm 5 includes a core 51 and a deformable part 52. The opening and closing drive mechanism 6 is connected to the core 51 and is used to drive the core 51 to move axially along the receiving cavity 7 to open and close the valve port 4. The deformable part 52 connects the core 51 and the side wall of the receiving cavity 7. The deformable part 52 includes a first deformable section 521 and a second deformable section 522 that alternately arch into the receiving cavity 7 when the core 51 opens and closes the valve port 4. An annular gradient surface 8 is formed between the core 51 and the opening and closing drive mechanism 6.

[0031] In this circulating diaphragm valve, when the core 51 of the diaphragm 5 closes the valve port 4 under the driving action of the opening and closing drive mechanism 6, as... Figure 1 As shown, only the first deformed section 521 or the portion of the second deformed section 522 that arches into the receiving cavity 7 is in a suspended state within the second channel 3. At this time (when the core 51 closes the valve port 4), the air pressure within the second channel 3 acts in both directions along the driving direction of the opening and closing drive mechanism 6 on the first deformed section 521 and the annular gradient surface 8. That is, the first deformed section 521 and the annular gradient surface 8 can offset part of the counter-thrust force of the pressure (air pressure and / or hydraulic pressure) within the second channel 3 on the opening and closing drive mechanism 6, thereby reducing the thrust of the opening and closing drive mechanism 6 on the core 51. Furthermore, the drive core 51 of the opening and closing drive mechanism 6 moves from the position where the valve port 4 is open (e.g., Figure 2 During the process of moving from the deformable part 52 to the closed valve port 4 position, only the arched portion of the deformable part 52 or the connection portion between the external deformable part 52 and the edge of the arched portion is in a suspended state in the second channel 3. Similarly, the air pressure in the second channel 3 acts in both directions along the driving direction of the opening and closing drive mechanism 6 on the arched portion of the deformable part 52 and the annular gradient surface 8. That is, the arched portion of the deformable part 52 and the annular gradient surface 8 can offset part of the counter-thrust force of the pressure in the second channel 3 on the opening and closing drive mechanism 6, thereby reducing the driving force of the opening and closing drive mechanism 6 on the core 51. In other words, the counter-thrust force of the pressure in the second channel 3 on the opening and closing drive mechanism 6 is reduced during the process of driving the core 51 to close the valve port 4 and in the state of closing the valve port 4. Accordingly, a lower power opening and closing drive mechanism 6 can be selected, which can reduce the weight, volume and space occupied by the opening and closing drive mechanism 6.

[0032] Furthermore, firstly, with the core 51 closed at valve port 4, the opening / closing drive mechanism 6 experiences a small reaction force within the second channel 3, resulting in high stability during closure. Secondly, since the deformable portion 52 arches along the driving direction of the opening / closing drive mechanism 6, the reaction force from the second channel 3 on the arched portion is either the same as or opposite to the driving direction of the opening / closing drive mechanism 6, thus improving the stability of the opening / closing drive mechanism 6 in driving and closing the valve. Thirdly, the deformable portion 52 can be designed to experience a greater pressure from the second channel 3 along the driving direction of the opening / closing drive mechanism 6 than the pressure from the annular gradient surface 8 along the same driving direction of the opening / closing drive mechanism 6, ensuring that when the pressure within the second channel 3 exceeds a set value, the deformable portion 52 pushes the core 51 to open valve port 4, achieving a pressure relief protection effect. Fourthly, the size of the arched portion of the deformable portion 52 and the size of the annular gradient surface 8 can be selected according to different working conditions to meet different requirements and improve adaptability.

[0033] Furthermore, in this embodiment, an annular gradient surface 8 is formed on the outer periphery of the core 51 and is arranged axially opposite to the deformable portion 52 in the receiving cavity 7. A deformable cavity 9 communicating with the second channel 3 is formed between the annular gradient surface 8 and the deformable portion 52. Thus, the pressure in the second channel 3 acts in both directions on the arched portion of the deformable portion 52 and the annular gradient surface 8 in the driving direction of the opening and closing drive mechanism 6. Specifically, the axial direction of the receiving cavity 7 is the same as the driving direction of the opening and closing drive mechanism 6. Preferably, the axial direction of the receiving cavity 7 is vertical.

[0034] Furthermore, in this embodiment, the annular gradient surface 8 is a conical surface that is smaller at the top and larger at the bottom. On the one hand, it is easy to process, and on the other hand, the pressure inside the second channel 3 has a good thrusting effect on the conical surface.

[0035] Furthermore, in this embodiment, the core 51 is smaller than the receiving cavity 7. Thus, when the valve port 4 is open, the core 51 can be located within the receiving cavity 7. At this time, the core 51 partially blocks the opening of the receiving cavity 7 towards the valve port 4, effectively closing the deformable part 52 within the receiving cavity 7. This reduces the impact of the fluid flow between the first channel 2 and the second channel 3 on the deformable part 52, thereby improving the service life of the diaphragm 5. Preferably, the outer diameter of the core 51 is close to the inner diameter of the receiving cavity 7. Even when the core 51 is located within the receiving cavity 7, there is a small gap between its outer wall and the inner wall of the receiving cavity 7, improving the protective effect of the core 51 on the deformable part 52.

[0036] Furthermore, in this embodiment, the core 51, the receiving cavity 7, and the valve port 4 are coaxial, and the inner surface of the receiving cavity 7 is a cylindrical surface.

[0037] Furthermore, in this embodiment, the outer periphery of the deformable portion 52 is provided with a peripheral portion 53, which is fitted and connected to the outer end face 71 of the receiving cavity 7. Under the constraint of the outer end face 71 of the receiving cavity 7, the peripheral portion 53 is less affected by the air pressure and / or hydraulic pressure of the first channel 2 and the second channel 3. Moreover, the fitted connection between the peripheral portion 53 and the outer end face 71 of the receiving cavity 7 can improve the connection strength between the diaphragm 5 and the sidewall of the receiving cavity 7.

[0038] Furthermore, in this embodiment, the core 51, the deformable part 52, and the peripheral part 53 are integrally formed, which is relatively separate. The pressure resistance and bending strength of the integrally formed diaphragm 5 are generally better.

[0039] Furthermore, in this embodiment, the opening and closing drive mechanism 6 includes a push-pull rod 61 and an opening and closing drive assembly 62 disposed on the main body 1. One end of the push-pull rod 61 is connected to the core 51 through a connector 63, and the other end is connected to the opening and closing drive assembly 62. The opening and closing drive assembly 62 drives the core 51 to open and close the valve port 4 through the connector 63.

[0040] Furthermore, in this embodiment, the connector 63 is coaxially connected to the core 51, and the outer diameter of the connector 63 is smaller than that of the core 51. Preferably, the connector 63 is fitted to the upper surface of the core 51. The smaller outer diameter of the connector 63 compared to the core 51 ensures that the annular gradient surface 8 is located on the outer periphery of the connector 63. Preferably, the outer periphery of the connector 63 includes a cylindrical surface, such that when the valve port 4 of the core 51 is closed, the second deformed segment 522 is pressed against this cylindrical surface. The difference between the inner diameter of the receiving cavity 7 and the outer diameter of the connector 63 satisfies the width requirement of the arched portion of the deformed part 52.

[0041] Furthermore, in this embodiment, the push-pull rod 61 is slidably mounted on the main body 1 and is coaxial with the receiving cavity 7.

[0042] Furthermore, in this embodiment, during the movement of the drive core 51 of the opening and closing drive mechanism 6 between the open valve port 4 position and the closed valve port 4 position, the deformable part 52 changes its arched position as the core 51 moves. Preferably, the arched part of the deformable part 52 is always located within the receiving cavity 7. The opening and closing drive mechanism 6 can adopt an existing telescopic drive mechanism.

[0043] The deformable portion 52 includes a first deformable segment 521 and a second deformable segment 522 that alternately arch into the receiving cavity 7 when the core portion 51 opens and closes the valve port 4. This can be understood as the second deformable segment 522 of the deformable portion 52 arching into the receiving cavity 7 when the core portion 51 opens the valve port 4, and the first deformable segment 521 of the deformable portion 52 arching into the receiving cavity 7 when the core portion 51 closes the valve port 4.

[0044] Preferably, in this embodiment, during the movement of the core 51 with the opening and closing drive mechanism 6, the shape of the arched portion of the deformable portion 52 remains basically unchanged.

[0045] Preferably, the opening and closing drive mechanism 6 is a linear drive mechanism such as a linear drive cylinder or hydraulic cylinder.

[0046] Another understandable advantage is that the first deformable section 521 and the second deformable section 522 alternately arch into the receiving cavity 7 when the valve port 4 is opened and closed in the core 51, thereby changing the arch position and improving service life compared to arching in one place. Preferably, the arch shape of the deformable section 52 is such that its reaction force direction towards the second channel 3 (generally vertically upward in actual use) is the same as the driving direction of the drive mechanism 6, such as the deformable section 52 arching in an arc shape.

[0047] Example 2:

[0048] Figure 3 and Figure 4 Another embodiment of the circulating diaphragm valve of this utility model is shown. The structure of this embodiment is basically the same as that of Embodiment 1, except that the opening and closing drive assembly 62 includes a cylinder 621, a piston 622, and an elastic element 623. The cylinder 621 is disposed on the main body 1, the piston 622 is disposed inside the cylinder 621 and connected to the core 51 (specifically, the piston 622 is connected to the push-pull rod 61), and the elastic element 623 is disposed between the piston 622 and the cylinder 621, so that the piston 622 has the force to extend outward and drive the core 51 to close the valve port 4. When the cylinder 621 is inflated, the piston 622 has the force to drive the core 51 to open the valve port 4 under the elastic force of the elastic element 623. Conversely, when the cylinder 621 is deflated, the force of the air pressure in the cylinder on the piston 622 is removed, thereby restoring the state in which the core 51 closes the valve port 4 under the elastic force of the elastic element 623.

[0049] In this circulating diaphragm valve, when the core 51 of the diaphragm 5 closes the valve port 4 under the elastic force of the elastic element 623, as... Figure 3 As shown, only the first deformed section 521 or the portion of the second deformed section 522 that arches into the receiving cavity 7 is in a suspended state within the second channel 3. At this time (when the core 51 closes the valve port 4), the air pressure within the second channel 3 acts in both directions along the movement direction of the piston 622 on the first deformed section 521 and the annular gradient surface 8. That is, the first deformed section 521 and the annular gradient surface 8 can partially offset the counterforce of the pressure (air pressure and / or hydraulic pressure) within the second channel 3 on the piston 622, thereby reducing the thrust of the opening / closing drive mechanism 6 on the core 51. Furthermore, the drive core 51 of the opening / closing drive mechanism 6 moves from the position where the valve port 4 is open (e.g., ...). Figure 4During the process of moving from the deformable part 52 to the closed valve port 4 position, only the arched portion of the deformable part 52 or the connection portion between the external deformable part 52 and the edge of the arched portion is in a suspended state in the second channel 3. Similarly, the air pressure in the second channel 3 acts in both directions along the moving direction of the piston 622 on the arched portion of the deformable part 52 and the annular gradient surface 8. That is, the arched portion of the deformable part 52 and the annular gradient surface 8 can offset part of the counter-thrust force of the pressure in the second channel 3 on the piston 622, thereby reducing the pushing force of the opening and closing drive mechanism 6 on the core 51. In other words, the counter-thrust force of the pressure in the second channel 3 on the opening and closing drive mechanism 6 is reduced during the process of driving the core 51 to close the valve port 4 and in the state of closing the valve port 4. Accordingly, a lower power opening and closing drive mechanism 6 can be selected, which can reduce the weight, volume and space occupied by the opening and closing drive mechanism 6.

[0050] Obviously, firstly, with the core 51 closing the valve port 4, the piston 622 experiences a small reaction force within the second channel 3, resulting in high stability during closure. Secondly, since the deformable part 52 arches along the direction of piston 622's movement, the reaction force from the second channel 3 on the arched part is either in the same direction as or opposite to the direction of piston 622's movement, improving the stability of the opening / closing drive mechanism 6 in driving and closing the valve. Thirdly, the deformable part 52 can be designed to experience a greater pressure from the second channel 3 along the direction of piston 622 than the pressure from the annular gradient surface 8 along the same direction of piston 622, ensuring that when the pressure within the second channel 3 exceeds a set value, the deformable part 52 pushes the core 51 to open the valve port 4, achieving pressure relief protection. Fourthly, the size of the arched part of the deformable part 52 and the size of the annular gradient surface 8 can be selected according to different working conditions to meet different requirements and improve adaptability.

[0051] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the present invention, or modify it into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, should fall within the protection scope of the present invention.

Claims

1. A circulating diaphragm valve, comprising a body (1) and a first channel (2), a second channel (3), a valve port (4), a diaphragm (5), and an opening / closing drive mechanism (6) disposed on the body (1), wherein the first channel (2) and the second channel (3) are connected through the valve port (4), characterized in that: The main body (1) is provided with a receiving cavity (7) at the position relative to the valve port (4). The diaphragm (5) includes a core (51) and a deformable part (52). The opening and closing drive mechanism (6) is connected to the core (51) and is used to drive the core (51) to move along the axial direction of the receiving cavity (7) to open and close the valve port (4). The deformable part (52) connects the core (51) and the side wall of the receiving cavity (7). The deformable part (52) includes a first deformable section (521) and a second deformable section (522) that alternately arch into the receiving cavity (7) when the core (51) opens and closes the valve port (4). An annular gradient surface (8) is formed between the core (51) and the opening and closing drive mechanism (6).

2. The circulating diaphragm valve according to claim 1, characterized in that: The annular gradient surface (8) is formed on the outer periphery of the core (51) and is arranged axially with the deformable part (52) in the receiving cavity (7). A deformable cavity (9) communicating with the second channel (3) is formed between the annular gradient surface (8) and the deformable part (52).

3. The circulating diaphragm valve according to claim 1, characterized in that: The annular gradient surface (8) is a conical surface that is smaller at the top and larger at the bottom.

4. The circulating diaphragm valve according to claim 2, characterized in that: The core (51) is smaller than the receiving cavity (7).

5. The circulating diaphragm valve according to claim 1, characterized in that: The core (51), the receiving cavity (7) and the valve port (4) are coaxial, and the inner surface of the receiving cavity (7) is a cylindrical surface.

6. The circulating diaphragm valve according to claim 1, characterized in that: The outer periphery of the deformable part (52) is provided with a peripheral part (53), and the peripheral part (53) is fitted and connected to the outer end face (71) of the receiving cavity (7).

7. The circulating diaphragm valve according to claim 6, characterized in that: The core (51), the deformable part (52), and the peripheral part (53) are integrally formed.

8. The circulating diaphragm valve according to any one of claims 1 to 7, characterized in that: The opening and closing drive mechanism (6) includes a push-pull rod (61) and an opening and closing drive assembly (62) disposed on the main body (1). One end of the push-pull rod (61) is connected to the core (51) through a connector (63), and the other end is connected to the opening and closing drive assembly (62).

9. The circulating diaphragm valve according to claim 8, characterized in that: The connector (63) is coaxially connected to the core (51), and the outer diameter of the connector (63) is smaller than that of the core (51).

10. The circulating diaphragm valve according to claim 8, characterized in that: The push-pull rod (61) is slidably mounted on the main body (1) and is coaxial with the receiving cavity (7).

Images