JP2020020475A - Shut-off valve - Google Patents

Abstract

To provide a shut-off valve of which part configuration is simplified and which has preferable sealability and safety.SOLUTION: A shut-off valve includes a valve body 6 and a valve element 1. The valve element 1 is fixedly connected to a male screw rod extending to the valve body 6, and relays and connects a female screw bushing 4 that is screwed with the male screw rod on the valve body 6. The female screw bushing 4 is restricted in the position thereof in an axial direction relative to the valve body 6, and drives and moves the valve element 1 while being rotated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to the field of valve technology, and more particularly to a closure valve.

  The valve plays an important role of shutting off and adjusting the medium in the conduit where it is located, but the shutoff valve is a very important shutoff type valve, and the opening and closing member of the shutoff valve is a valve body, It is mainly applied to shut off the medium in an ultra-low temperature environment. Currently, commercially available closing valves have a complicated component structure, and a driving mechanism for driving a valve body is generally connected to a valve stem by using a handwheel, but the production cost of the product is high, Moreover, the assembly is complicated.

  Accordingly, there is a need to provide a shut-off valve having a simple component configuration and low production costs.

  According to the present invention, in a closing valve including a valve body and a valve body, a male screw rod extending from the valve body is fixedly connected to the valve body, and a female screw bush that is screwed with the male screw rod rotates on the valve body. Connected, the female threaded bush provides a closing valve that drives and moves the valve element in a rotationally limited and axially limited position in the valve body.

  Further, a fluid passage and a valve seat surrounding the fluid passage are provided inside the valve body, and the valve body has a seal taper surface that abuts on the valve seat to close the fluid passage.

  Further, the valve body has a closed state in which the valve body comes into contact with the valve seat to close the fluid passage, and an open state in which the valve body is separated from the valve seat to open the fluid passage. Toggle open state.

  Further, the valve body has a first opening and a second opening communicating with the fluid passage, and the connection pipe is attached to at least one opening.

  Further, the valve seat and the valve body have an integral or separate structure.

  Further, the valve seat is fixed to the inner wall of the second opening, and the valve body is further provided with a third opening arranged opposite to the second opening, and the male screw rod of the valve body is provided with a third opening. Extending the valve body through the opening.

  Further, between the valve body and the valve seat, there is provided a position limiting mechanism which is fitted to each other and limits the relative position of the valve seat.

  Further, the position limiting mechanism includes a reduced diameter structure provided in the valve body, and a position limiting step located on the outer periphery of the valve seat and abutting on the reduced diameter structure.

  Further, the valve seat has a cylindrical shape, and the valve seat includes a sealing step portion that is fitted to the valve body toward one end of the third opening.

  Furthermore, one end of the valve seat facing away from the third opening is aligned with the edge of the second opening.

  Further, a connecting pipe is inserted and fixed to one end of the valve seat facing away from the third opening.

  Further, a mounting flange is fixed to the outer wall of the valve body.

  Further, the mounting flange is located on the outer periphery of the second opening portion.

  Further, the valve body and the externally threaded rod have an integral structure.

  Further, an axial position limiting step is provided on the inner wall of the valve body, and one end of the female screw bush is inserted into the valve body and fitted to the axial position limiting step.

  Further, an annular positioning seat is fixed in the valve body, the male screw rod extends from the valve body via the positioning seat, and the step for limiting the axial position is provided by the positioning seat.

  Further, the positioning seat is fixed near the third opening portion of the valve body and near the inner wall of the valve body.

  Further, the axial position limiting step is located on the axial end surface of the positioning seat or is annularly arranged on the inner wall of the positioning seat.

  Furthermore, an end portion of the female screw bush inserted into the valve body is provided with an outer jaw, and the axial position limiting step portion presses the outer jaw to restrict the female screw bush from being detached from the valve body. .

  Further, an operation member is fixedly connected to a portion of the female screw bush located outside the valve body.

  Further, the operating member and the positioning seat abut each other along the axial direction of the female screw bush.

  Further, the operation member is fixed so as to surround the outer periphery of the female screw bush.

  Further, the valve body is provided with a first positioning step which is fitted to the female screw bush and limits the limit position in the open state of the valve body.

  Further, the first positioning step portion is adjacent to a connecting portion between the valve body and the male screw rod.

  Further, the first positioning step portion is fitted by abutting on the axial end surface of the female screw bush, or is fitted by abutting on a second positioning step portion provided on the inner wall of the female screw bush. You.

  Further, a seal sleeve for blocking a gap between the male screw rod and the female screw bush is further provided in the valve body.

  Further, an annular positioning seat is fixed in the valve body, the male screw rod extends to the valve body through the positioning seat, and the seal sleeve is fitted to the valve body in the axial direction of the seal sleeve. It has a first seal end and a second seal end fitted to the positioning seat.

  Further, the sealing sleeve is a bellows tube.

  Further, the first seal sleeve hermetically covers the outer periphery of the valve body.

  Further, an annular convex portion is provided on the outer periphery of the valve body, and the first seal end portion hermetically covers the outer peripheral surface of the annular convex portion.

  Further, the second sealing end hermetically covers the outer periphery of the positioning seat.

  Furthermore, the second sealing end is fixed in a radial gap between the positioning seat and the valve body.

  The present invention provides a shut-off valve that has a simple component configuration, low production cost, and is easy to assemble, and that is used to shut off a refrigerant medium at a very low temperature in a fluid passage. Also, one end of the bellows tube is fixed to the positioning seat, and the other end is fixed to the valve body. One closed space is formed by sealing the positioning seat, the bellows tube, and the valve body, and the valve body reciprocates up and down. Thus, a dynamic seal is formed, and the sealing performance of the gap between the valve body and the positioning seat is improved. The closing valve provided by the present invention is low in cost, has good sealing properties, is used in an air conditioning area, can prevent refrigerant leakage at an extremely low temperature, and has reliable reliability.

FIG. 2 is a schematic view illustrating a structure of a closing valve according to an embodiment of the present invention in which a valve is fully opened. FIG. 2 is a schematic view of a structure in which a valve of the closing valve in FIG. 1 is fully closed. FIG. 3 is a schematic perspective view of the shut-off valve of FIG. 2. FIG. 2 is a schematic diagram of a valve body structure of the closing valve in FIG. 1. FIG. 2 is a schematic view of a valve seat structure of the closing valve in FIG. 1. FIG. 2 is a structural schematic view of a valve body part of the closing valve of FIG. 1. It is a structure schematic diagram of the valve body of FIG. FIG. 7 is a structural schematic diagram of the bellows tube of FIG. 6. FIG. 7 is a schematic structural view of a positioning seat in FIG. 6. FIG. 7 is a schematic structural diagram of a female screw bush and a rotary nut of FIG. 6. It is a top view of FIG.

  In the following embodiments, the present invention will be further described with reference to the above-mentioned drawings.

  In the embodiments of the present invention, the terms indicating the directions, that is, upper, lower, left, and right are defined based on the drawings in the drawings attached to the specification, but are merely for easy understanding and description. This is not intended to limit the scope of protection of the present application, and the same applies to the following contents, and thus will not be described repeatedly.

  Referring to FIGS. 1 to 11, an embodiment of the present invention is directed to a closing valve including a valve body 6 and a valve body 1, wherein a male screw rod 101 extending the valve body 6 is fixedly connected to the valve body 1. A female screw bush 4 screwed with the male screw rod 101 is rotatably connected to the valve body 6, and the female screw bush 4 drives the valve body 1 in a state where the position thereof is limited in the axial direction of the valve body 6 and the female screw bush 4 rotates. To provide a closing valve to exercise.

  It is understood that the valve body 1 moves within the valve body 6, and the direction of movement of the valve body 1 may be up and down movement, left and right movement or movement at a certain angle, depending on the position of the valve body 6. It will not be described again. The valve element 1 and the male screw rod 101 may be separate structures or may be integrated structures, but it is sufficient that the valve element 1 can achieve driving by the driving mechanism. In the present embodiment, an example in which the valve element 1 moves up and down along the valve body 6 will be described. However, the valve element 1 and the male screw rod 101 adopt an integral structure. It is fixedly connected to form an integral valve body and has a simple structure. The drive mechanism is a female screw bush 4, the female screw bush 4 and the valve body 6 are rotationally connected, the female screw bush 4 rotates with respect to the valve body 6, and the female screw bush 4 is axially restricted in the valve body 6. Therefore, the female screw bush 4 cannot move along the axial direction of the valve body 6. The valve body 1 of the present embodiment moves up and down in the valve body 6 under the driving action of the female screw bush 4, thereby blocking the fluid passage 65 formed in the valve body 6, so that the overall structure is reduced. The fluid medium flowing in the fluid passage 65 is simple and easy to assemble, and may be a liquid or a gas. In this embodiment, the fluid medium is used for flowing the refrigerant at an extremely low temperature.

  In the present embodiment, a fluid passage 65 and a valve seat 7 surrounding the fluid passage 65 are provided inside the valve body 6, and the valve body 1 has a seal tapered surface 106 that abuts on the valve seat 7 and closes the fluid passage 65. Have. The valve seat 7 is located at the bottom end of the valve body 6 and is provided so as to surround the fluid passage 65, the valve body 1 moves downward, and the seal taper surface 106 of the valve body 1 comes into contact with the valve seat 7. Thus, the fluid passage 65 formed in the valve body 6 is shut off, and the sealing effect is enhanced.

  Specifically, the valve body 1 has a closed state in which the valve body 1 is in contact with the valve seat 7 to close the fluid passage 65, and an open state in which the valve body 1 is separated from the valve seat 7 to open the fluid passage 65. The female screw bush 4 is driven to switch between the closed state and the open state.

  The position of the valve body 1 is adjusted so that the valve body 1 moves up and down internally along the valve body 6 by driving the female screw bush 4 and a closed state of the fluid passage 65 and an open state of the fluid passage 65 are formed. It can be understood that switching is performed at any time. When the valve element 1 moves downward along the valve body 6, the valve element 1 comes into contact with the valve seat 7, shuts off the fluid passage 65, and a closed state in which the fluid passage 65 is closed is formed. On the other hand, when the valve element 1 moves upward along the valve body 6, the valve element 1 is separated from the valve seat 7 to open the fluid passage 65, so that fluid can flow in the fluid passage 65, An open state of the passage 65 is formed.

  Specifically, the valve body 6 has a first opening 61 and a second opening 63 that communicate with the fluid passage 65, and a connection pipe is attached to at least one of the openings. It can be seen that the valve body 6 changes the flow direction of the fluid through the passage of the fluid medium formed by the installation of the opening to achieve the flow of the fluid in the opening. A connection pipe is connected to the opening so that a new fluid medium passage can be formed. Whether or not the connection pipe is attached depends on the situation, but the connection pipe is connected to the first opening 61 as required for installation. Alternatively, a connecting pipe may be connected to the second opening 63, or a connecting pipe may be connected to both openings. When the valve element 1 moves downward, the fluid medium passage formed between the first opening 61 and the second opening 63 is shut off.

  Specifically, the first opening 61 is provided on a side wall of the valve body 6, the second opening 63 is a bottom of the valve body 6, and connects the first connection pipe 8 to the first opening 61. Alternatively, the second connection pipe 9 may be connected to the second opening 63, and when the valve body 1 moves downward, the seal taper surface 106 of the valve body 1 and the valve seat 7 are closed. , The passage through which the fluid medium flows between the second opening 63 and the valve body 6 is shut off, in other words, the passage of the second connecting pipe 9 and the first opening 61, the second connecting pipe 9 and the second The passage for the fluid medium formed between the first connection pipe 8 and the connection pipe 8 is blocked.

  Specifically, the valve seat 7 and the valve body 6 have an integral or separate structure. When the valve seat 7 and the valve body 6 are integral, the components of the closing valve are simple and can be fixed without further installation of a fixing device between the valve seat 7 and the valve body 6. When the valve seat 7 and the valve body 6 are separate bodies, replacement of parts is easy, and the position of the valve seat 7 can be set as needed.

  Specifically, the valve seat 7 is fixed to the inner wall of the second opening 63, and the valve body 6 is further provided with a third opening 64 arranged opposite to the second opening 63. One male threaded rod 101 extends the valve body 6 through the third opening 64.

  The valve seat 7 may be fixed to the inner wall of the second opening 63 by conventional means such as welding, and the second opening 63 is located at the bottom end of the valve body 6. It can be seen that a third opening 64 is located at the top end, and the female screw bush 4 is provided in the third opening 64.

  In the present embodiment, between the valve body 6 and the valve seat 7, a position limiting mechanism that couples with each other and limits the relative position of the valve seat 7 is provided. The position limiting mechanism limits the relative position of the valve seat 7 so that the valve seat 7 can easily enter the valve body 6, and when welding and fixing to the valve body 6, the position of the valve seat 7 is accurately determined, 7 is prevented from being difficult to fix in the valve body 6.

  Specifically, the position limiting mechanism includes a reduced diameter portion 62 structure provided on the valve body 6 and a position limiting step which is located on the outer periphery of the valve seat 7 and is fitted in contact with the reduced diameter portion 62 structure. A part 72 is included. It can be appreciated that the position limiting mechanism may be other conventional means, such as by means of a locating pin.

  Specifically, the valve seat 7 has a cylindrical shape, and the valve seat 7 includes a sealing step 71 that is fitted to the valve body 1 toward one end of the third opening 64. The sealing step 71 abuts the sealing tapered surface 106 of the valve body 1 to enhance the sealing effect.

  In the present embodiment, a connection pipe is inserted and fixed to one end of the valve seat 7 facing away from the third opening 64. That is, when the second connection pipe 9 is inserted into the position of the second opening 63 to extend the fluid passage, and the valve body 1 moves downward in the flow passage, the second connection pipe 9 is connected to the second connection pipe 9. The fluid passage with the first opening 61 is shut off.

  Specifically, one end of the valve seat 7 facing the third opening 64 is aligned with the edge of the second opening 63. The valve seat 7 is aligned with the second opening 63 so that the parts are aligned flat and the connection of the second connection pipe 9 is facilitated.

  In this embodiment, a mounting flange 10 is fixed to an outer wall of the valve body 6 to facilitate connection between the valve body 6 and other members.

  Specifically, the mounting flange 10 is located on the outer periphery of the second opening 63. The valve body 6 is fixed to the second connection pipe 9 by the mounting flange 10, and the flange can improve the sealing performance and the fastening performance between the second connection pipe 9 and the valve body 6.

  Specifically, the valve body 1 and the male screw rod 101 have an integral structure. It can be understood that the male screw rod 101 is a portion of the valve body 1 where the screw is provided, and the valve body 1 and the male screw rod 101 have an integral structure, have a simple component structure, and are easy to mount.

  In this embodiment, an axial position limiting step 31 is provided on the inner wall of the valve body 6, and one end of the female screw bush 4 is inserted into the valve body 6 and fits into the axial position limiting step 31. Are combined. The position of the female screw bush 4 in the axial direction is fixed by the axial position limiting step 31 so that the female screw bush 4 does not move up and down along the valve body 6. It can be understood that the axial position limiting step 31 may be provided on the valve body 6 or may be provided by another component provided separately on the valve body 6.

  In this embodiment, an annular positioning seat 3 is fixed in the valve body 6, the male screw rod 101 extends from the valve body 6 via the positioning seat 3, and the axial position limiting step 31 is It is provided by a positioning seat 3. The positioning seat 3 and the valve body 6 are fixedly connected, the positioning seat 3 includes a through hole, the female screw bush 4 is placed in the positioning seat 3, and the female screw bush 4 is provided with an axial position limiting step 31 of the positioning seat 3. It can be understood that the externally threaded rod 101 is driven to extend the valve body 6 through the positioning seat 3 by being connected to the valve body 6.

  Specifically, the positioning seat 3 is fixed to the third opening 64 of the valve body 6 in close contact with the inner wall thereof. The positioning seat 3 can be fixedly connected to the inner wall of the valve body 6 by using a method such as welding, and the positioning seat 3 can be fixedly connected to the third opening 64 of the valve body 6, that is, the valve. Close to the upper end portion of the body 6, the female screw bush 4 facilitates driving and moving the valve body 1 by fixing the positioning seat 3.

  Specifically, the axial position limiting step 31 is located on the axial end surface of the positioning seat 3 or is annularly arranged on the inner wall of the positioning seat 3 so that the female screw bush 4 can be connected thereto. Since the axial position limiting step 31 is located on the axial end face of the positioning seat 3, it is easy to assemble the female screw bush 4 integrally. The position where the female screw bush 4 and the positioning seat 3 are rotationally connected may be the top end, the middle, or the bottom end of the positioning seat 3 as long as the rotational connection can be achieved.

  Specifically, one end portion of the female screw bush 4 inserted into the valve body 6 is provided with an outer jaw 41, and an axial position limiting step portion presses the outer jaw 41 to press the valve body of the female screw bush 4. Limit exit from 6.

  In this embodiment, an operation member 5 is fixedly connected to a portion of the female screw bush 4 located outside the valve body 6. Since the operating member 5 provides one good force applying point to the outside, by applying an external force to the operating member 5, the female screw bush 4 is driven to rotate, and the valve element 1 is moved in the axial direction of the screw bush 4. It can be understood that the valve element 1 is driven so as to make a linear reciprocating motion along the axis. The operation member 5 may be a rotating nut, a fixed plate, a fixed rod, or the like. The operation member 5 is fixedly connected to the female screw bush 4.

  Specifically, the operation member 5 and the positioning seat 3 abut each other along the axial direction of the female screw bush 4. The operation member 5 contacts the upper end of the positioning seat 3 and is rotatable with respect to the positioning seat 3.

  Specifically, the operation member 5 is fixed so as to surround the outer periphery of the female screw bush 4. The operating member 5 employs a rotating nut, and the rotating nut is fixedly connected to the female screw bush 4. However, the operating member 5 may be a rotating nut or another force plate or a force rod. . The fixed connection can employ welding or other fixed connection schemes conceivable to those skilled in the art. The rotating nut may be a polygonal nut, for example a hexagonal nut or an octagonal nut, but it will be understood that a hexagonal nut which is advantageous for operation and rotation is preferred.

  One end of the female screw bush 4 is connected to the rotating nut, and the other end is connected to the positioning seat 3. It is sufficient that this connection condition is satisfied within the range of the height of the female screw bush 4. The height of the female screw bush 4 is the same as the sum of the height of the positioning seat 3 and the height of the rotating nut, so that the space can be more rationally distributed.

  In the present embodiment, the valve element 1 is provided with a first positioning step 105 that is fitted to the female screw bush 4 and limits the limit position of the valve element 1 in the open state. When the valve element 1 moves toward the third opening 64, the first positioning step 105 abuts on the female screw bush 4 to limit the limit position of the valve element 1 in the open state. The first positioning step 105 prevents the valve element 1 from rotating and detaching from the female screw bush 4.

  Specifically, the first positioning step 105 is adjacent to a portion where the valve body 1 and the male screw rod 101 are connected.

  Specifically, the first positioning step 105 is fitted in contact with the axial end surface of the female screw bush 4 or the second positioning step 42 provided on the inner wall of the female screw bush 4. Abuts and is fitted. It can be understood that the first positioning step 105 is fitted in contact with the axial end surface of the female screw bush 4 to limit the limit position in the open state of the valve body 1. In order to achieve a better fitting operation, a second positioning step 42 is provided on the inner wall of the female screw bush 4, and the second positioning step 42 is formed by the first positioning step 105. To limit the limit position of the valve element 1 in the open state.

  In the present embodiment, a seal sleeve 2 that blocks a gap between the male screw rod 101 and the female screw bush 4 is further provided in the valve body 6. The seal sleeve 2 can increase the sealing effect and prevent the fluid medium in the fluid passage 65 from flowing into the gap between the male screw rod 101 and the female screw bush 4. It can be understood that the sealing sleeve 2 is an elastic sleeve and can change in the size of the space according to the movement of the valve body 1.

  Specifically, an annular positioning seat 3 is fixed in the valve body 6, and the male screw rod 101 extends from the valve body 6 through the positioning seat 3, and the seal sleeve 2 extends in the axial direction of the seal sleeve 2. 2 has a first seal end 21 fitted to the valve body 1 and a second seal end 22 fitted to the positioning seat 3. An outer jaw 41 is provided at one end of the female screw bush 4 to be inserted into the valve body, and the axial position limiting step 31 of the positioning seat 3 presses the outer jaw 41 so that the female screw bush is separated from the valve body 6. Limit withdrawal. One sealed space is formed by the sealing of the positioning seat 3, the seal sleeve 2, and the valve body 1, and a dynamic seal is formed in the vertical reciprocating process of the valve body 1, and a gap between the valve body 1 and the positioning seat 3 is formed. Improve the sealing performance of

  Specifically, the seal sleeve 2 is a bellows tube. It can be seen that the bellows tube 2 forms a dynamic seal during the movement of the valve body. The bellows tube 2 is provided with an elastic bellows, which can expand and contract vertically.

  Specifically, the first seal end 21 hermetically covers the outer periphery of the valve body 1. An annular convex portion 103 is provided on the outer periphery of the valve body 1, the first seal end 21 hermetically covers the outer peripheral surface of the annular convex portion 103, and the annular convex portion 103 is This is advantageous for a tight connection between the sealing sleeve 2 and the sealing sleeve 2.

  The second seal end 22 hermetically covers the outer periphery of the positioning seat 3. The second seal end 22 is fixed in a radial gap between the positioning seat 3 and the valve body 6. The second sealing end 22 is connected to the positioning seat 3, on one side of which the sealing sleeve 2 can be fixed by means of the positioning seat 3, and on the other hand the sealing of the gap between the valve element 1 and the positioning seat 3. Can be improved.

  The valve body 6 is formed integrally, and the valve body 6 is made of thin stainless steel, so that the production cost is low and the performance is good. The valve element 1 is a cylindrical multi-boss (original notation: multi-convex base), and has good structural stability.

  In this embodiment, the closing valve has a simple component structure, is easy to assemble, and has good sealing properties. At the same time, the closing valve employing a bellows tube is more sealed than the commercially available O type, and can effectively improve the sealing performance of the closing valve, and is a closing valve used in the market, which is a closing valve made entirely of brass. As compared with the above, the production cost is high, and the thin-walled stainless steel employed in the embodiment of the present invention has good safety, the production cost is low, and when used in an air-conditioning area, the refrigerant leakage in an ultra-low temperature environment is reduced. It can be effectively prevented and its safety is reliable.

The specific achievement process of this embodiment is as follows.
The process of fully opening the valve body 1: rotating the rotation nut clockwise, the rotation nut rotates the female screw bush 4 in conjunction with it, and the female screw bush 4 moves the valve body 1 in conjunction with the screw to move upward. , The bellows tube 2 is contracted. When the seal taper surface 106 of the valve body 1 comes into contact with the second positioning step 42 at the bottom of the female screw bush 4, the valve body is fully opened. The bellows pipe 2, the valve body 1 and the positioning seat 3 form a closed cavity, which prevents refrigerant from leaking.

  The process of fully closing the valve body 1: rotating the rotating nut counterclockwise, the rotating nut rotates the female screw bush 4 in conjunction with it, and the female screw bush 4 links the valve body 1 with a screw and moves downward. Move, the bellows tube 2 is extended. When the seal taper surface 106 at the bottom of the valve body 1 comes into contact with the sealing step 71 of the valve seat 7, the valve body 1 is fully closed, the valve body 1 and the valve seat 7 form a seal, Prevent leaks.

  Although the technical features of the above-described embodiments can be arbitrarily combined, for the sake of simplicity, not all combinations of the technical features of the above-described embodiments are described. Unless there is a contradiction in the combination of these technical features, all are considered to be within the scope described in this specification.

  The examples described above merely represent some embodiments of the present invention, the description of which is more specific and detailed, but is understood to limit the scope of the patent. should not be done. It should be noted that those skilled in the art may make some modifications and improvements without departing from the spirit of the present invention, all of which fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be based on the appended claims.

Valve 1
Male thread rod 101
Annular convex part 103
First positioning step 105
Seal taper surface 106
Seal sleeve 2
First seal end 21
Second seal end 22
Positioning seat 3
Axial position limiting step 31
Internal thread bush 4
Outer jaw 41
Second positioning step 42
Operation member 5
Valve body 6
First opening 61
Reduced diameter part 62
Second opening 63
Third opening 64
Fluid passage 65
Valve seat 7
Step 71 for seal
Position Limit Step 72
First connection pipe 8
Second connecting pipe 9
Mounting flange 10

Claims (10)

  A closing valve including a valve body and a valve body, wherein a male screw rod extending from the valve body is fixedly connected to the valve body, and a female screw bush that is screwed with the male screw rod rotates on the valve body. A closing valve which is connected and drives and moves the valve body in a state in which the internal thread bush is axially restricted and rotated in the valve body.   2. The valve body according to claim 1, further comprising a fluid passage and a valve seat surrounding the fluid passage inside the valve body, wherein the valve body has a seal tapered surface that abuts the valve seat to close the fluid passage. 3. Closing valve.   The valve body has a closed state in which the valve body comes into contact with the valve seat to close the fluid passage, and an open state in which the valve body is separated from the valve seat to open the fluid passage.The valve body is brought into a closed state by driving a female screw bush. 3. The closing valve according to claim 2, wherein the opening state is switched.   An axial position limiting step is provided on the inner wall of the valve body, and one end of the female screw bush is inserted into the valve body and fitted to the axial position limiting step. The closure valve according to claim 1.   An annular positioning seat is fixed in the valve body, the male screw rod extends from the valve body through the positioning seat, and the axial position limiting step is provided by the positioning seat. The closing valve according to claim 4, wherein:   One end of the female screw bush inserted into the valve body has an outer jaw, and the axial position limiting step portion presses the outer jaw to restrict the female screw bush from coming off the valve body. The closing valve according to claim 4, wherein the closing valve is operated.   The closing valve according to claim 1, wherein an operation member is fixedly connected to a portion of the female screw bush located outside the valve body.   The closure valve according to claim 1, further comprising a seal sleeve in the valve body, the seal sleeve blocking a gap between the male screw rod and the female screw bush.   An annular positioning seat is fixed in the valve body, the male threaded rod extends from the valve body through the positioning seat, and in the axial direction of the seal sleeve, the seal sleeve is fitted to the valve body. 9. A closure valve according to claim 8, having a first sealed end that fits and a second sealed end that fits into the positioning seat. The closure valve according to claim 9, wherein the seal sleeve is a bellows tube.