CN113883294A

CN113883294A - Gate valve

Info

Publication number: CN113883294A
Application number: CN202111286664.5A
Authority: CN
Inventors: 陆诗雨; 李晓慧; 郑志刚
Original assignee: Individual
Current assignee: Xifulong Valve Group Co Ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2022-01-04
Anticipated expiration: 2041-11-02
Also published as: CN113883294B

Abstract

The invention relates to a gate valve, comprising: the valve body, the valve gap, the valve rod, first valve plate, the second valve plate, switching components, can make first valve plate switch between a plurality of operating positions through rotatory valve rod, when first valve plate is in first operating position, the fluid pipeline can be blocked to the valve plate, the rotatory valve rod of forward, can make the valve plate rebound to second operating position, make the fluid passage intercommunication, continue the rotatory valve rod of forward, can make first valve plate continue rebound to third operating position, make first valve plate be connected with switching components, when first valve plate is in third operating position, it is rotatory through control switching components, can switch the position of first valve plate and second valve plate, thereby make the second valve plate be connected with the valve rod. The invention has the advantages that: through setting up first valve plate and second valve plate, wearing and tearing appear at first valve plate and make the gate valve produce the back of revealing, can replace first valve plate with the second valve plate that sets up in the gate valve in advance to the life of extension gate valve.

Description

Gate valve

Technical Field

The invention relates to the field of pipeline valves, in particular to a gate valve.

Background

The valve rod is promoted and the valve rod descends in the rotation of current gate valve depended on hand wheel drive valve-stem nut to open and close of practical gate valve, the wide application in industrial fields such as electric power, oil, chemical industry, metallurgy, mining, sewage treatment, current gate valve often appears following problem when using:

1. due to the structural characteristics of the gate valve, a valve plate and a valve seat of the gate valve need to be tightly matched, so that the valve plate and the valve seat generate large friction when the gate valve is opened and closed, the valve plate is easy to wear, and in the opening and closing processes of the gate valve, the speed of a medium flowing through the valve plate is high, the sealing surface of the valve plate is damaged by impact, the gate valve leaks, and the service life of the gate valve is influenced;

2. when the gate valve is maintained, the gate valve needs to be detached from a pipeline and then maintained by the existing maintenance method, so that the process is complicated, and the work of the whole system is influenced; a large amount of medium flows out of the pipeline, so that the working environment is polluted;

the present invention is designed to solve the above problems.

Disclosure of Invention

In view of the above, it is necessary to provide a gate valve in order to solve the above problems.

The invention discloses a gate valve, which comprises: a valve body having a fluid conduit and a central cavity, the central cavity communicating with the fluid conduit through a communication opening; the valve cover is arranged at the upper end of the valve body in a covering manner so as to seal the upper side of the middle cavity; the valve rod is connected with the valve cover in a threaded mode and extends into the middle cavity; a first valve plate rotatably connected to a lower end of the valve stem, the first valve plate being capable of extending into the fluid conduit through the communication opening to block the fluid conduit; a switching assembly disposed within the lumen; and a second valve plate connected to the switching assembly, wherein the first valve plate can be switched between a first operating position, a second operating position, and a third operating position by rotating the valve rod, wherein when the first valve plate is in the first operating position, the valve plate can block the fluid conduit, the valve rod is rotated in a forward direction, the valve plate can be moved upward to the second operating position, the fluid conduit is communicated, the valve rod is rotated in the forward direction, the first valve plate can be moved upward to the third operating position, the first valve plate is connected to the switching assembly, and when the first valve plate is in the third operating position, the switching assembly is rotated to switch positions of the first valve plate and the second valve plate, so that the second valve plate is connected to the valve rod.

In one embodiment, the switching component includes a shaft rod, a rotating sleeve, a clamping jaw, a first jaw arm, and a second jaw arm, the shaft rod is fixedly disposed in the middle cavity, a first flow passage is disposed in the middle of the shaft rod, the fluid pipeline is unidirectionally communicated with the first flow passage through a check valve, the middle cavity can be communicated with the first flow passage through a stop valve, a driving cavity is disposed in the valve cover, the driving cavity is semi-cylindrical, the rotating sleeve is sleeved on the shaft rod, a first torsion spring is disposed between the rotating sleeve and the shaft rod, a driving flap is disposed on the rotating sleeve, the driving flap is located in the driving cavity and divides the driving cavity into a first containing cavity and a second containing cavity, the first containing cavity is communicated with the first flow passage through a second flow passage, the clamping jaw is rotatably disposed on the shaft rod, a ratchet wheel is disposed on the rotating sleeve, the clamping jaw piece is provided with a pawl which is abutted to the ratchet wheel, so that the clamping jaw piece can rotate in one direction relative to the rotating sleeve, the first jaw arm and the second jaw arm are hinged to the clamping jaw piece, the first jaw arm can be matched with the clamping jaw piece to clamp the first valve plate, the second jaw arm can be matched with the clamping jaw piece to clamp the second valve plate, when the first valve plate moves to a third working position, the stop valve can be opened by the first valve plate, the first accommodating cavity is communicated with the middle cavity, and therefore the rotating sleeve rotates forwards for 180 degrees under the action of the first torsion spring, and the positions of the first valve plate and the second valve plate are switched.

In one embodiment, the one-way valve is composed of a first elastic member and a valve ball, so that liquid can enter the first cavity from the fluid pipeline in a one-way mode.

In one embodiment, the stop valve is composed of a valve core and a second elastic part, a first pushing inclined surface is arranged on the first valve plate, and when the first valve plate moves from the second working position to the third working position, the first pushing inclined surface can push the valve core to move so as to open the stop valve, so that liquid can enter the middle cavity from the first cavity.

In one embodiment, a second pushing inclined surface is arranged on the second valve plate and matched with the first pushing inclined surface to form an annular inclined surface.

In one embodiment, a T-shaped connecting protrusion is arranged at the lower end of the valve rod, a first T-shaped groove is formed in the first valve plate, the T-shaped connecting protrusion can extend into the first T-shaped groove, so that the valve rod is connected with the first valve plate, a second T-shaped groove is formed in the second valve plate, and when the first valve plate and the second valve plate are switched, the T-shaped connecting protrusion can extend into the second T-shaped groove, so that the valve rod is connected with the second valve plate.

In one embodiment, a first connecting block is fixedly arranged on the first valve plate, a second connecting block is fixedly arranged on the second valve plate, a first connecting groove and a second connecting groove are respectively formed in the clamping jaw piece in the vertical direction, the second connecting block is connected to the second connecting groove, and when the first valve plate moves to a third working position, the first connecting block can extend into the first connecting groove, so that when the rotating sleeve rotates, the first valve plate and the second valve plate can be driven to rotate simultaneously.

In one embodiment, a second torsion spring is arranged at the hinged position of the first claw arm and the claw piece, so that the first claw arm and the claw piece can clamp the first valve plate, and a third torsion spring is arranged at the hinged position of the second claw arm and the claw piece, so that the second claw arm and the claw piece can clamp the second valve plate.

In one embodiment, the first valve plate can divide the fluid pipeline into an inlet pipe and an outlet pipe, and the first flow passage is communicated with the inlet pipe.

In one embodiment, a side cover plate is arranged on the side wall of the middle cavity on the valve body.

The invention has the advantages that:

1. by arranging the first valve plate and the second valve plate, after the gate valve leaks due to abrasion of the first valve plate, the first valve plate can be replaced by the second valve plate which is arranged in the gate valve in advance, so that the service life of the gate valve is prolonged;

2. by arranging the side cover plate, after the second valve plate is replaced, the gate valve is closed, the side cover plate can be opened, the worn first valve plate is taken out, and a new valve plate is replaced for later use, so that the operation is simple and convenient;

3. the clamping jaw piece and the jaw arm are arranged to clamp the valve plate, so that the valve plate can be forcibly removed when the valve plate is replaced, and the operation is simple and convenient;

4. through the arrangement of the switching assembly, after the valve plate rises to the right position, the valve core is touched to enable the medium in the first containing cavity to enter the middle cavity, so that the rotary sleeve is driven to rotate under the action of the torsion spring to drive the clamping jaw piece to rotate, the position of the first valve plate and the position of the second valve plate are changed, after the second valve plate closes the fluid pipeline again, the medium enters the first containing cavity through the one-way valve to push the rotary sleeve to rotate, and the torsion spring stores the force again for next replacement; the replacement mode is simple and quick, can be completed only by rotating the valve rod, and is simple to operate.

Drawings

FIG. 1 is a sectional view of the gate valve of the present invention in a closed state;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1 in accordance with the present invention;

FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1 in accordance with the present invention;

FIG. 4 is a cross-sectional view of the present invention according to another operating condition of FIG. 3;

FIG. 5 is a cross-sectional view of the present invention with the valve flap replaced;

fig. 6 is a sectional view showing the gate valve of the present invention in an opened state.

FIG. 7 is a perspective view of the first valve plate of the present invention with the first connecting block hidden.

In the drawings, a valve body 1, a fluid pipe 11, a fluid inlet pipe 111, a fluid outlet pipe 112, a middle chamber 12, a communication opening 13, a side cover plate 14, a valve cover 2, a first containing cavity 211, a second containing cavity 212, a second flow passage 22, a valve rod 3, a T-shaped connecting protrusion 31, a first valve plate 4, a first pushing inclined surface 41, a first T-shaped groove 42, a first connecting block 43, a second valve plate 5, a second pushing inclined surface 51, a second T-shaped groove 52, a second connecting block 53, a shaft 61, a first flow passage 611, a rotating sleeve 62, a driving lobe 621, a ratchet 622, a clamping jaw member 63, a pawl 631, a first connecting groove 632, a second connecting groove 633, a first jaw arm 64, a second torsion spring 641, a second jaw arm 65, a third torsion spring 651, a first elastic member 661, a valve ball 662, a second elastic member 671, a valve core 672, and a first torsion spring 68 are shown.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "mounted on" another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1, the present invention discloses a gate valve, which comprises: the valve comprises a valve body 1, a valve cover 2, a valve rod 3, a first valve plate 4 and a switching assembly, wherein the valve body 1 is provided with a fluid pipeline 11 and a middle cavity 12, and the middle cavity 12 is communicated with the fluid pipeline 11 through a communication opening 13; the valve cover 2 is arranged at the upper end of the valve body 1 in a covering manner so as to seal the upper side of the middle cavity 12; the valve rod 3 is connected with the valve cover 2 in a threaded mode and extends into the middle cavity 12; a first valve plate 4 rotatably connected to a lower end of the valve stem 3, the first valve plate 4 being capable of protruding into the fluid conduit 11 through the communication opening 13 to block the fluid conduit 11; the switching assembly is disposed within the central cavity 12; the second valve plate 5 is connected to the switching assembly,

the first valve plate 4 can be switched between a first working position, a second working position, and a third working position by rotating the valve stem 3, as shown in figure 1, when the first valve plate 4 is in the first work position, it is able to block the fluid duct 11, as shown in fig. 5, the valve plate can be moved up to the second working position by rotating the valve stem 3 in the forward direction, the fluid passages are communicated, as shown in fig. 6, the first valve plate 4 can be moved upwards to the third working position by rotating the valve rod 3 in the forward direction, the first valve plate 4 is connected with the switching assembly, when the first valve plate 4 is in the third working position, the switching assembly can automatically rotate, so that the positions of the first valve plate 4 and the second valve plate 5 can be switched to connect the second valve plate 5 to the stem 3.

It is worth mentioning that the valve cover 2 is composed of a first cover body and a second cover body, the first cover body is covered on the valve body 1, the second cover body is fixedly connected with the first cover body, and the valve rod 3 is in threaded connection with the second cover body.

Preferably, the switching assembly includes a shaft 61, a rotating sleeve 62, a jaw member 63, a first jaw arm 64, and a second jaw arm 65, the shaft 61 is fixedly disposed in the middle cavity 12, as shown in fig. 2, a first flow channel 611 is disposed in the middle of the shaft 61, the first flow channel 611 is communicated with the fluid pipeline 11 through a one-way valve, the first flow channel 611 is communicated with the middle cavity 12 through a stop valve, a driving cavity is disposed in the valve cover 2, the driving cavity is semi-cylindrical, the rotating sleeve 62 is sleeved on the shaft 61, a first torsion spring 68 is disposed between the rotating sleeve 62 and the shaft 61, a driving flap 621 is disposed on the rotating sleeve 62, the driving flap 621 is disposed in the driving cavity and divides the driving cavity into a first cavity 211 and a second cavity 212, the first cavity 211 is communicated with the first flow channel 611 through a second flow channel 22, the jaw member 63 is rotatably disposed on the shaft 61, the rotating sleeve 62 has a ratchet 622, the jaw member 63 has a pawl 631 abutting against the ratchet 622, so that the jaw member 63 can rotate in one direction relative to the rotating sleeve 62, the first jaw arm 64 and the second jaw arm 65 are both hinged to the jaw member 63, the first jaw arm 64 and the jaw member 63 cooperate to clamp the first valve plate 4, the second jaw arm 65 and the jaw member 63 cooperate to clamp the second valve plate 5, and when the first valve plate 4 moves to the third working position, the first valve plate 4 can open the stop valve to communicate the first cavity 211 with the middle cavity 12, so that the rotating sleeve 62 rotates forward 180 degrees under the action of the first torsion spring 68 to switch the positions of the first valve plate 4 and the second valve plate 5.

Preferably, the first valve plate 4 can divide the fluid pipeline 11 into an inlet pipe 111 and an outlet pipe 112, and the first flow channel 611 is communicated with the inlet pipe 111.

Preferably, the check valve is composed of a first elastic member 661 and a valve ball 662 for allowing the liquid to flow from the fluid conduit 11 into the first receiving chamber 211 in one direction.

Preferably, the stop valve is composed of a valve core 672 and a second elastic member 671, and a first pushing inclined surface 41 is disposed on the first valve plate 4, and when the first valve plate 4 moves from the second working position to the third working position, the first pushing inclined surface 41 can push the valve core 672 to move so as to open the stop valve, so that liquid can enter the middle cavity 12 from the first accommodating cavity 211.

It should be mentioned that, when the first torsion spring 68 is in a deformation state, the stop valve is opened, the rotating sleeve 62 can rotate forward under the action of the first torsion spring 68, and when the stop valve is closed and the fluid pipeline 11 is in a stop state, the pressure of the medium in the fluid inlet pipe 111 is higher, and the medium can enter the first accommodating cavity 211 through the check valve to push the rotating sleeve 62 to rotate reversely, so that the first torsion spring 68 deforms.

Preferably, the second valve plate 5 is provided with a second pushing inclined surface 51, and the second pushing inclined surface and the first pushing inclined surface are matched to form an annular inclined surface.

Preferably, the first sliding ramp 41 and the second sliding ramp 51 form an annular ramp, so that the shut-off valve is always open during rotation of the rotary sleeve 62.

Preferably, the lower end of the valve rod 3 is provided with a T-shaped connecting protrusion 31, the first valve plate 4 is provided with a first T-shaped groove 42, the T-shaped connecting protrusion 31 can extend into the first T-shaped groove 42, so that the valve rod 3 is connected with the first valve plate 4, the second valve plate 5 is provided with a second T-shaped groove 52, and when the first valve plate 4 and the second valve plate 5 are exchanged, the T-shaped connecting protrusion 31 can extend into the second T-shaped groove 52, so that the valve rod 3 is connected with the second valve plate 5.

It should be noted that the T-shaped connecting protrusion 31 can rotate in the first T-shaped groove 42 and the second T-shaped groove 52.

Preferably, a first connecting block 43 is fixedly arranged on the first valve plate 4, a second connecting block 53 is fixedly arranged on the second valve plate 5, a first connecting groove 632 and a second connecting groove 633 are respectively arranged on the clamping jaw 63 along the vertical direction, the second connecting block 53 is connected to the second connecting groove 633, when the first valve plate 4 moves to the third working position, the first connecting block 43 can extend into the first connecting groove 632, so that when the rotating sleeve rotates, the first valve plate 4 and the second valve plate 5 can be simultaneously driven to rotate.

Preferably, a second torsion spring 641 is provided at a hinge between the first claw arm 64 and the claw member 63 so as to allow the first claw arm 64 and the claw member 63 to sandwich the first valve plate 4, and a third torsion spring 651 is provided at a hinge between the second claw arm 65 and the claw member 63 so as to allow the second claw arm 65 and the claw member 63 to sandwich the second valve plate 5.

Preferably, a side cover plate 14 is arranged on the side wall of the middle cavity 12 of the valve body 1.

The working mode of the invention is as follows: as shown in fig. 1, the first valve plate 4 is in the first working position, blocking the fluid conduit 11, so that the medium in the fluid inlet pipe 111 maintains a high pressure state, the check valve is opened through the first flow channel 611, and enters the first receiving cavity 211 through the second flow channel 22, and the driving flap 621 is pushed to rotate, so that the first torsion spring 68 is in a deformed state.

As shown in fig. 6, by rotating the valve stem 3 in the forward direction, the first valve plate 4 is moved up to the second operating position, so that the fluid conduit 11 can be fully opened.

When the first valve plate 4 needs to be replaced, the valve rod 3 continues to be rotated in the forward direction, so that the first valve plate 4 moves from the second working position to the third working position, as shown in fig. 5, at this time, the first connecting block 43 of the first valve plate 4 extends into the first connecting groove 632, and the first pushing inclined surface 41 of the first valve plate 4 pushes the valve core 672 of the stop valve when rising to the top, so as to open the stop valve, because the middle chamber 12 is communicated with the liquid outlet pipe 112 of the fluid pipeline 11 at this time, the medium in the first accommodating chamber 211 can enter the middle chamber 12 through the second flow passage 22 and the first flow passage 611, that is, as shown in fig. 4, the rotating sleeve 62 rotates in the forward direction under the action of the first torsion spring 68, and drives the clamping jaw 63 to rotate in the forward direction through the action of the ratchet 622 and the pawl 631, so that the first valve plate 4 and the second valve plate 5 can switch positions, it is worth mentioning that, during the rotating process, the T-shaped coupling protrusion 31 is separated from the first T-shaped groove 42 and then coupled to the second T-shaped groove 52. Then, the valve rod 3 is rotated reversely, so that the second valve plate 5 is lowered to the first working position, and since the fluid pipeline 11 is blocked, the pressure in the fluid inlet pipe 111 rises, and enters the first cavity 211 through the one-way valve, the first flow passage 611 and the second flow passage 22, the rotating sleeve 62 is pushed to rotate reversely, since the rotating sleeve 62 is connected with the pawl 631 through the ratchet 622, the pawl 63 is kept stationary while the rotating sleeve 62 rotates reversely, and thus the switching of the valve plates is completed.

By opening the side cover plate 14, the worn first valve plate 4 can be removed and replaced with a new one, ready for the next replacement.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A gate valve, said gate valve comprising:

a valve body having a fluid conduit and a central cavity, the central cavity communicating with the fluid conduit through a communication opening;

the valve cover is arranged at the upper end of the valve body in a covering manner so as to seal the upper side of the middle cavity;

the valve rod is connected with the valve cover in a threaded mode and extends into the middle cavity;

a first valve plate rotatably connected to a lower end of the valve stem, the first valve plate being capable of extending into the fluid conduit through the communication opening to block the fluid conduit;

a switching assembly disposed within the lumen;

a second valve plate connected to the switching assembly,

the valve rod is rotated to switch the first valve plate among a first working position, a second working position and a third working position, when the first valve plate is located at the first working position, the valve plate can block the fluid pipeline, the valve rod is rotated in a forward direction, the valve plate can be moved upwards to the second working position to enable the fluid pipeline to be communicated, the valve rod is rotated in the forward direction continuously, the first valve plate can be moved upwards to the third working position continuously, the first valve plate is connected with the switching assembly, when the first valve plate is located at the third working position, the switching assembly is rotated to switch the positions of the first valve plate and the second valve plate, and therefore the second valve plate is connected with the valve rod.

2. The gate valve of claim 1, wherein the switching assembly comprises a shaft, a rotating sleeve, a clamping jaw, a first clamping jaw, and a second clamping jaw, the shaft is fixedly disposed in the middle cavity, a first flow channel is disposed in the middle of the shaft, the fluid pipeline is unidirectionally communicated with the first flow channel through a check valve, the middle cavity can be communicated with the first flow channel through a stop valve, a driving cavity is disposed in the valve cover, the driving cavity is semi-cylindrical, the rotating sleeve is sleeved on the shaft, a first torsion spring is disposed between the rotating sleeve and the shaft, a driving flap is disposed on the rotating sleeve, the driving flap is disposed in the driving cavity and divides the driving cavity into a first containing cavity and a second containing cavity, the first containing cavity is communicated with the first flow channel through a second flow channel, and the clamping jaw is rotatably disposed on the shaft, the rotary sleeve is provided with a ratchet wheel, a pawl abutting against the ratchet wheel is arranged on the jaw piece, so that the jaw piece can rotate in one direction relative to the rotary sleeve, the first jaw arm and the second jaw arm are hinged to the jaw piece, the first jaw arm can be matched with the jaw piece to clamp the first valve plate, the second jaw arm can be matched with the jaw piece to clamp the second valve plate, when the first valve plate moves to a third working position, the stop valve can be opened by the first valve plate, the first accommodating cavity is communicated with the middle cavity, and therefore the rotary sleeve rotates forwards by 180 degrees under the action of the first torsion spring, and the positions of the first valve plate and the second valve plate are switched.

3. The gate valve of claim 2, wherein the one-way valve is comprised of a first resilient member and a valve ball to enable one-way entry of fluid from the fluid conduit into the first chamber.

4. The gate valve of claim 3, wherein the stop valve is composed of a valve core and a second elastic member, and the first valve plate is provided with a first pushing inclined surface, and when the first valve plate moves from the second working position to the third working position, the first pushing inclined surface can push the valve core to move so as to open the stop valve, so that liquid can enter the middle cavity from the first cavity.

5. The gate valve of claim 4, wherein the second valve plate is provided with a second pushing inclined surface, and the second pushing inclined surface and the first pushing inclined surface are matched to form an annular inclined surface.

6. The gate valve of claim 2, wherein a T-shaped connecting protrusion is disposed at a lower end of the valve stem, a first T-shaped groove is formed in the first valve plate, the T-shaped connecting protrusion can extend into the first T-shaped groove, so that the valve stem is connected with the first valve plate, a second T-shaped groove is formed in the second valve plate, and when the first valve plate and the second valve plate are shifted, the T-shaped connecting protrusion can extend into the second T-shaped groove, so that the valve stem is connected with the second valve plate.

7. The gate valve of claim 2, wherein the first valve plate is fixedly provided with a first connecting block, the second valve plate is fixedly provided with a second connecting block, the clamping jaw member is respectively provided with a first connecting groove and a second connecting groove along a vertical direction, the second connecting block is connected to the second connecting groove, and when the first valve plate moves to the third working position, the first connecting block can extend into the first connecting groove, so that the rotating sleeve can simultaneously drive the first valve plate and the second valve plate to rotate when rotating.

8. The gate valve of claim 2, wherein a second torsion spring is provided at a hinge joint of the first claw arm and the claw member to allow the first claw arm and the claw member to clamp the first valve plate, and a third torsion spring is provided at a hinge joint of the second claw arm and the claw member to allow the second claw arm and the claw member to clamp the second valve plate.

9. The gate valve of claim 2, wherein the first valve plate is capable of dividing the fluid conduit into an inlet conduit and an outlet conduit, the first flow passage being in communication with the inlet conduit.

10. The gate valve of claim 2, wherein a side cover plate is provided on the valve body on the sidewall of the central chamber.