CN210069104U - Self-locking valve and system - Google Patents

Abstract

The utility model relates to the technical field of valves, a self-locking valve is disclosed, including the valve rod, drive valve rod pivoted fastener, its characterized in that are connected at the valve rod top: the valve rod and the clamping piece are provided with self-locking mechanisms, each self-locking mechanism comprises an opening and closing stroke slot hole formed in the clamping piece, a pushing block fixed on the valve rod and capable of moving relatively in the opening and closing stroke slot hole, and clamping grooves which are formed in the clamping piece and the valve rod respectively and matched with each other; the clamping piece is connected with the valve rod in a rotating fit mode. This self-locking valve can realize the valve self-locking function when the closed condition, can not directly open the valve once more after the auto-lock. The valve can be prevented from being opened by mistake due to misoperation, so that accidents are avoided. The safety operation of the valve is improved, and the personal safety of workers is guaranteed.

Description

Self-locking valve and system

Technical Field

The utility model relates to the technical field of valves, especially, relate to a self-locking valve and system.

Background

Valves are plumbing accessories used to open and close a pipe, control flow direction, regulate and control parameters of the transport medium (temperature, pressure and flow). The valve is a control part in a fluid conveying system and has the functions of stopping, adjusting, guiding, preventing counter flow, stabilizing pressure, shunting or overflowing and relieving pressure and the like. Valves used in fluid control systems range in variety and size from the simplest shut-off valves to the variety of valves used in extremely complex autonomous systems.

The valves are distributed in all corners of urban pipeline construction, such as tap water pipelines, natural gas pipelines, heat supply pipelines and the like, and are closely related to the living and living environment safety of people. In addition, the valve is also widely applied to the fields of chemical engineering, pharmacy and the like to control process equipment or production flow. When the valve works and the pipeline is maintained or emergency occurs, the valve needs to be turned off emergently, and the medium in the pipeline is prevented from being continuously conveyed to cause damage to the downstream. However, in the existing valve, anyone can open or close the valve when in use, and the random operability has great potential safety hazard and management loophole. In view of the above problems in the use of valves, there is a need for a valve that is self-locking, safe and effective. In the (possible) emergency or accident situation when the pipeline normally conveys the medium, anyone can close the cut-off valve, so as to avoid accidents or safety accidents or reduce the damage degree caused by the accidents as much as possible. And, the lock is died immediately after the valve is closed, and anyone can not open the valve again directly. The opening of the valve requires a key to open the closed valve by a professional manager or an authorized operator. The valve is prevented from being opened mistakenly again under the condition that the emergency is not processed, so that accidents are prevented.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a self-locking valve and system to solve the above-mentioned technical problem among the prior art.

The utility model adopts the technical proposal that:

a self-locking valve comprises a valve rod, wherein the top of the valve rod is connected with a clamping piece driving the valve rod to rotate, self-locking mechanisms are arranged on the valve rod and the clamping piece, each self-locking mechanism comprises an opening and closing stroke slot hole formed in the clamping piece, a push block fixed on the valve rod and capable of moving relatively in the opening and closing stroke slot hole, and clamping grooves which are respectively formed in the clamping piece and the valve rod and are matched with each other; the clamping piece is connected with the valve rod in a rotating fit mode.

According to the self-locking valve provided by the utility model, the self-locking mechanism is a closed position self-locking mechanism, when the valve rod is in an open position state, the push block is at the starting end of the opening and closing stroke slot hole; the opening and closing stroke slot hole is arc-shaped and coaxial with the valve rod.

According to the self-locking valve provided by the utility model, the self-locking mechanism is an open position self-locking mechanism, and when the valve rod is in a closed position, the push block is at the tail end of the opening and closing stroke slot hole; the opening and closing stroke slot hole is arc-shaped and coaxial with the valve rod.

According to the utility model provides a self-locking valve, fixedly connected with handle on the fastener.

According to the utility model provides a self-locking valve, the draw-in groove prolongs fastener and valve rod axial setting respectively on the rotation face.

According to the utility model provides a self-locking valve, the outside cover of valve rod is equipped with the valve rod sealing joint of coaxial setting, is provided with stop gear on valve rod sealing joint and the fastener.

According to the utility model provides a self-locking valve, stop gear includes the locking portion that the valve rod sealing joint top takes shape and the block portion that fastener bottom takes shape.

According to the self-locking valve provided by the utility model, the locking part and the clamping part are respectively provided with two step surfaces with different heights, and are mutually clamped and matched; the distance between the two steps of the locking part is matched with the opening and closing stroke of the clamping piece, and a blocking piece which limits the movement between the two steps of the locking part is fixed on the valve rod.

According to the utility model provides a self-locking valve, fixedly connected with fastener locking subassembly can be dismantled on the top of valve rod, and fastener locking subassembly includes the screw, and supports the fastener and press the clamp plate on valve rod top.

The utility model discloses another technical scheme do:

a self-locking valve system comprises the self-locking valve in any one of the technical schemes, and is characterized by further comprising an unlocking key, wherein the unlocking key is clamped with the clamping groove.

The utility model has the advantages that:

this self-locking valve can realize the valve self-locking function when the closed condition, can not directly open the valve once more after the auto-lock. The valve can be prevented from being opened by mistake due to misoperation, so that accidents are avoided. The safety operation of the valve is improved, and the personal safety of workers is guaranteed.

This self-locking valve can also realize the valve self-locking function when the open mode, can not directly close the valve once more after the auto-lock. The valve can be prevented from being closed by mistake in misoperation, and the material conveying is interrupted.

Drawings

Fig. 1 is a schematic structural view (exploded view) of a preferred embodiment of the present invention;

in order to show the structure clearly, a partial enlarged view of the locking part and a multi-view of the handle and the clamping part are also shown in fig. 1;

FIG. 2 is a schematic top view of FIG. 1 (with the engagement portion and handle omitted);

fig. 3 is a schematic structural view (semi-sectional view) of a preferred embodiment of the present invention;

FIG. 4 is a schematic structural view (full section) of a preferred embodiment of the present invention;

FIG. 5 is a schematic illustration of the operation of the preferred embodiment of the present invention;

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but 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, and thus, it should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; of course, mechanical connection and electrical connection are also possible; alternatively, they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Example one

As shown in fig. 1-5, the present invention provides a self-locking valve, which comprises a valve rod 8, a fastener for driving the valve rod to rotate is connected to the top of the valve rod 8, a self-locking mechanism is provided on the valve rod 8 and the fastener, the self-locking mechanism comprises a switching stroke slot 16 formed on the fastener, a push block 11 fixed on the valve rod 8 and capable of moving relatively in the switching stroke slot 16, and a slot groove formed on the fastener and the valve rod 8 respectively and matched with each other; the clamping piece is connected with the valve rod 8 in a rotating fit mode.

The self-locking mechanism is an off-position self-locking mechanism, and when the valve rod 8 is in an on-position state, the push block 11 is positioned at the starting end of the opening and closing stroke slotted hole 16; the opening and closing stroke slot hole 16 is arc-shaped and coaxial with the valve rod 8.

The outside cover of valve rod 8 is equipped with the valve rod sealing joint of coaxial setting, is provided with stop gear on valve rod sealing joint and the fastener.

The limiting mechanism comprises a locking part 5 formed at the top of the valve rod sealing joint and a clamping part 19 formed at the bottom of a clamping piece,

the locking part 5 and the clamping part 19 are respectively provided with two step surfaces with different heights and are mutually clamped and matched; the distance between the two steps of the locking part 5 is matched with the opening and closing stroke of the clamping piece, and a blocking piece 7 which limits the movement between the two steps of the locking part 5 is fixed on the valve rod 8.

Specifically, the locking part 5 is formed with a first step 13 and a second step 12, a gap is formed between the first step 13 and the second step 12, and the first step 13 is higher than the second step 12; the blocking piece 7 extends outwards from the radius direction of the cylindrical surface of the valve rod 8 and is limited in the gap; the push block 11 is arranged above the blocking piece 7.

The blocking piece 7 is a blocking column, a blocking pin and a blocking block.

The push block 11 is provided with a key, a key groove is correspondingly formed in the cylindrical surface of the valve rod 8, and the key is fixedly embedded in the key groove.

The two blocking members 7 are symmetrically distributed on two sides of the valve rod 8. Since the blocking member 7 is disposed in the gap, the blocking member 7 is restricted by the first step 13 and the second step 12 when rotating with the valve stem 8, and cannot be separated from the gap.

The first step 13 and the second step 12 are generally oppositely disposed. The first step 13 and the second step 12 are arc-shaped plates, and are integrally formed with the locking part 5 and the valve rod sealing joint.

The clamping part 19 is annular, and a through hole in the center of the clamping part is used for inserting and fixing the valve rod 8; the inner arc surface of the opening and closing stroke slot hole 16 is penetrated through the through hole; the push block 11 penetrates through and is limited in the opening and closing stroke slot hole 16, and the starting end of the opening and closing stroke slot hole 16 can push the push block 11 to drive the valve rod 8 to rotate; a third step 18 is formed on the bottom surface of the clamping part 19, and the third step 18 is matched with the first step 13 and the second step 12; the third step 18 is in surface contact with the second step 12, and the third step 18 is limited by the first step 13 when rotating with the handle 17.

In addition, the self-locking valve also comprises a valve body which mainly comprises a shell and a ball body 2, wherein the ball body 2 is arranged in the shell and is in sealing connection; the upper part of the shell is provided with a valve rod sealing joint; the top of the sphere 2 is fixedly connected with a valve rod 8, and the valve rod 8 penetrates through a valve rod sealing joint to extend outwards and is connected with the valve rod sealing joint in a sealing manner; the clamping part 19 is matched with and clamped and connected with the locking part 5; the push block 11 and the blocking piece 7 are fixed on the valve rod 8, specifically on the outer circular surface thereof; applying a torque M to a handle 17 (the handle 17 is fixedly connected to the clamping part 19), driving the valve rod 8 by the push block 11 under the action of the handle 17 so as to drive the ball 2 to rotate, wherein the ball is pushed by the starting end of the opening and closing stroke slot hole 16, meanwhile, the clamping part 19 rotates on the locking part 5 and drives the blocking piece 7 to be locked at the first position, and the ball 2 and the shell form a closed-circuit closed valve; the handle 17 (the handle 17 is fixedly connected to the clamping part 19) is applied with reverse torque T, the push block 11 is fixed, the clamping part 19 reversely idles on the locking part 5 and is locked in a buckling mode at the second position, at the moment, the push block 11 changes from the starting end to the tail end of the opening and closing stroke slot hole 16, and the valve rod 8 and the ball body 2 keep the original position and do not rotate.

Regarding the valve body, its technical scheme belongs to prior art. The valve cover 4 with (hard) sealing function is arranged in the spherical shell, and the two ends of the spherical shell are fixedly connected with the valve cover 4 connected with the pipeline.

The valve rod sealing joint is cylindrical or round table-shaped, the center of the valve rod sealing joint is provided with an avoiding hole for the valve rod 8 to penetrate through, and a sealing element is arranged between the through hole wall and the valve rod 8.

It is also known in the art to provide a sealing connection (seal) between the valve stem 8 and the valve stem sealing joint. For example: a plurality of seals, specifically O-shaped sealing rings, are arranged between the valve rod 8 and the flange, an outer ring 6 is further embedded outside the valve rod 8 above the O-shaped sealing ring on the uppermost layer, the outer ring 6 compresses the O-shaped sealing ring downwards, and the O-shaped sealing ring deforms to block a gap between the valve rod 8 and the flange to play a sealing role.

The clamping part 19 is fixedly connected with a handle 17, and an operator can manually pull the handle 17 to rotate the clamping part 19 to drive the valve rod 8 to rotate. Of course, the engaging portion 19 may be provided with a pneumatic or electric automatic valve opening actuator for automatically opening and closing the valve.

The top end of the valve rod 8 is detachably and fixedly connected with a clamping piece locking assembly, the clamping piece locking assembly comprises a screw 10, and the screw 10 is screwed into the end part of the valve rod 8 and presses the clamping piece against a pressing plate 10 at the top end of the valve rod 8.

The embodiment of the utility model provides a theory of operation is:

all parts of the valve are mutually matched according to the design principle, the assembly relation and the connection relation. When the valve is in the normal open position (i.e., the valve is open and open (see fig. 5-1)), the handle 17 can be directly operated to rotate the valve clockwise (according to industry regulations, and normally closed clockwise) to close the valve (see fig. 5-2). If the handle 17 is operated again to open the valve (the handle 17 is rotated counterclockwise), at this time, the handle 17 can only rotate reversely for a certain angle (the specific angle depends on the clearance and is 90 degrees in the figure), and the valve is still in the off-position state (i.e. the valve is closed and closed (see fig. 5-3)), so that the valve off-position locking state is achieved, i.e. the valve can only be closed and can not be opened, and the valve can not be directly opened again when being in the off-position. The self-locking valve is also called as a closed position self-locking valve.

Specific analysis:

see the following working principle of the second embodiment of the present invention.

Example two

As shown in fig. 1-5, the utility model provides a self-locking valve system, including the self-locking valve of embodiment one among the above-mentioned technical scheme, still include unlocking key 20, unlocking key 20 and draw-in groove block. The unlocking key is inserted into the clamping groove and is in inner meshing connection; when the valve is opened, the reverse torque T drives the clamping part 19 to rotate, the valve rod 8 is driven to rotate reversely through the unlocking key, the idle state of the clamping part 19 is broken, the clamping part 19 drives the blocking piece 7 to be locked at the second position, and the ball body 2 and the shell form an open circuit to open the valve.

The clamping grooves respectively extend the clamping pieces and the valve rod 8 to be axially arranged on the rotating surface. Specifically, the card slot is divided into a first groove 14 and a second groove 15. The first groove 14 is vertically formed on the cylindrical surface of the valve rod 8; the second groove 15 is vertically formed in the wall of the through hole, and the second groove 15 and the first groove 14 can be matched to form a clamping groove which is a lock hole.

In addition, a notch avoiding the lock hole is formed on the pressing plate 9 of the clamping piece locking assembly, so that the lock hole is exposed.

The embodiment of the utility model provides a second theory of operation is:

all parts of the valve are mutually matched according to the design principle, the assembly relation and the connection relation. When the valve is in the normal open position (i.e., the valve is open and open (see fig. 5-1)), the handle 17 can be directly operated to rotate the valve clockwise (according to industry regulations, and normally closed clockwise) to close the valve (see fig. 5-2). If the handle 17 is operated again to open the valve (the handle 17 is rotated counterclockwise), at this time, the handle 17 can only rotate reversely for a certain angle (the specific angle depends on the clearance, which is 90 degrees in the figure), and the valve is still in the off-position state (i.e. the valve is closed and closed (see fig. 5-3)), so that the valve off-position locking state is achieved, that is, the valve can only be closed and can not be opened. If the valve needs to be opened again, an operator needs to insert a special unlocking key 20 into a lock hole formed by matching the clamping part 19 of the handle 17 and the valve rod 8 (in a valve closed state (see fig. 5-4)), and then the handle 17 is rotated anticlockwise, so that the valve can be normally opened); after the valve access in place is opened (see fig. 5-5), the unlocking key 20 is taken down, the valve is restored to the normal working state, the valve can be directly closed, and the valve cannot be directly opened after being closed.

Specific analysis:

as shown in fig. 1, the a surface and the B surface are the top surfaces of the first step 13 and the second step 12 on the locking portion 5, respectively, and the B surface is lower than the a surface. The two side surfaces of the first step 13 and the second step 12 are respectively related to position limiting surfaces Q2 and Q1 and position limiting surfaces S1 and S2 (for the open position and the closed position, see the explanation above). I.e. when the stop 7 is restrained against the face Q2 and/or Q1, the valve is closed; when the stop 7 is restrained against the faces S1 and/or S2, the valve is now open. K3 and Q4 are both end faces of the engaging portion 19 for opening and closing the stroke slot 16. K1, K2 are the both sides of the key, and K1 is the driving plane, and the key cooperates and blocks in opening and closing the stroke slotted hole 16, can drive its valve stem 8 to rotate by the K3 face of opening and closing the stroke slotted hole 16 on the clamping part 19. The P surface is the outer circle surface of the limiting column or the limiting pin. E. The surface F is the top surface of the third step 18 on the engaging portion 19, the side surface S3 of the third step 18 is the off-position stopper surface of the engaging portion 19, and Q3 is the on-position stopper surface of the engaging portion 19. The surface E of the engaging portion 19 is in surface contact with the surface B of the lock portion 5, the surface F is in surface contact with the surface A, and the engaging portion 19 is meshed with the lock portion 5.

The valve is normally open as shown in fig. 5-1, and when bending moment M is applied (usually, the handle 17 is rotated 90 degrees clockwise), the valve is closed as shown in fig. 5-2. In the process of rotating the clockwise operating handle 17, the K3 surface of the opening and closing stroke slot 16 on the engaging portion 19 is always abutted against the K1 surface of the key on the valve rod 8, so as to drive the valve rod 8 and the ball 2 to rotate clockwise until the P surface of the valve rod 8 simultaneously touches the S1 surface of the first step 13 and/or the S2 surface of the second step 12 and then is limited and can not rotate continuously (the position where the parts are matched is the first position at this time), and the valve can be closed, as shown in fig. 5-2. The ball 2 always makes synchronous rotary motion when the valve rod 8 rotates.

As shown in fig. 5-2, the valve is in a closed and self-locking state. 1. When the handle 17 continues to apply the bending moment M, the handle 17 rotates clockwise, and the Q3 surface of the third step 18 on the engaging portion 19 just collides with the Q2 surface of the first step 13 on the locking portion 5, so that the handle 17 cannot rotate clockwise any more, and the valve rod 8 cannot rotate (at this time, the position where the components are engaged is the first position). The valve is always in the closed state. 2. At this time, when a reverse bending moment T is applied (usually, the counterclockwise operating handle 17 is reversely rotated by 90 degrees), the engaging portion 19 is merely idle, and cannot drive the valve rod 8 to synchronously rotate. In the process of reversely rotating the counterclockwise operating handle 17, the key on the valve rod 8 only idles in the opening and closing stroke slot 16, namely, the K1 surface and the K2 surface idle in the opening and closing stroke slot 16, and the K3 surface and the Q4 surface cannot push the K1 surface and the K2 surface to drive the valve rod 8 to rotate. The valve is now in a closed state. As shown in fig. 5-2, when the handle 17 continues to rotate counterclockwise, the handle 17 cannot rotate any further (the position where the parts are engaged is the second position) because the S3 surface on the engaging portion 19 just hits the S1 surface of the first step 13 on the locking portion 5 and is limited by the stop. In the process, the handle 17 rotates anticlockwise and cannot drive the valve rod 8 to rotate synchronously to open the valve, and the valve is always in a closed state, namely the valve cannot be opened by self-locking, as shown in fig. 5-3.

As shown in fig. 5-4, the valve can be opened and closed normally only when the unlocking key 20 is inserted. In the valve off state, the handle 17 is rotated, and the handle 17 idles, so that the second groove 15 and the first groove 14 are matched to form a lock hole, and the unlocking key 20 is inserted into the lock hole. The unlocking part of the unlocking key 20 is used for clamping and fastening the second groove 15 and the first groove 14 together, so that the valve rod 8 and the clamping part 19 can be linked. A new transmission chain is formed between the clamping part 19 (the handle 17) and the valve rod 8, the operating handle 17 rotates anticlockwise, the valve rod 8 and the ball body 2 synchronously rotate, and then the valve can be opened and is in a passage state, as shown in figures 5-5. If the unlocking key 20 is pulled out, the operating handle 17 rotates clockwise to close the valve, and the valve cannot be opened directly after being closed, and the principle is not repeated.

EXAMPLE III

The technical scheme of the self-locking valve can also be applied to the state that the pipeline is normally not closed. For example, to supply refrigerant to the equipment for cooling the equipment. When the refrigerant is interrupted to be conveyed, the equipment cannot be fully radiated and burnt out. At this moment, the self-locking valve is an open-position self-locking valve, and the specific application is as follows: the valve is closed and is in a closed position, and the pipeline is closed at the moment; when the refrigerant needs to be conveyed, the valve and the pipeline passage are opened by the operating handle 17, and the refrigerant starts to be conveyed; in the refrigerant conveying process, the valve is in an open position, the valve cannot be directly closed again, and the valve is in an open position locking state; namely, the valve can only be opened but not closed, and the valve can not be directly closed again when the valve is opened.

When the valve needs to be closed, the unlocking key 20 is used for clamping with the clamping groove; the valve can be closed at this time.

The specific technical scheme is as follows:

a self-locking valve comprises a valve rod 8, wherein the top of the valve rod 8 is connected with a clamping piece driving the valve rod to rotate, self-locking mechanisms are arranged on the valve rod 8 and the clamping piece, each self-locking mechanism comprises an opening and closing stroke slot hole 16 formed in the clamping piece, a push block 11 which is fixed on the valve rod 8 and can relatively move in the opening and closing stroke slot hole 16, and clamping grooves which are respectively formed in the clamping piece and the valve rod 8 and are matched with each other; the clamping piece is connected with the valve rod 8 in a rotating fit mode.

The self-locking mechanism is an open-position self-locking mechanism, and when the valve rod 8 is in an off-position state, the push block 11 is positioned at the tail end of the opening and closing stroke slotted hole 16; the opening and closing stroke slot hole 16 is arc-shaped and coaxial with the valve rod 8.

When the opening and closing stroke slot 16 rotates counterclockwise along with the handle 17 and the clamping part 19, the tail end of the opening and closing stroke slot can push the push block 11 to drive the valve rod 8 and the ball 2 connected with the valve rod to rotate counterclockwise, and the valve is opened. Thereafter, when the handle 17 and the engaging portion 19 rotate clockwise, the push block 11 changes from the end of the opening/closing stroke slot 16 to the starting end (the push block 11 "idles" in the opening/closing stroke slot 16, and actually the push block 11 does not rotate, and the idling phenomenon is relative rotation caused by the rotation of the engaging portion 19), while the valve rod 8 and the ball 2 keep the original position and do not rotate, and the valve is no longer closed, and is in the open position self-locking state.

The specific working principle of the open position self-locking valve refers to the working principle of the closed position self-locking valve in the second comparative example, which is not difficult to understand and is not repeated.

Finally, it should be noted that: the above embodiments are only preferred embodiments of the present invention to illustrate the technical solution of the present invention, but not to limit the technical solution, and the patent scope of the present invention is not limited; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; in addition, will the technical scheme of the utility model direct or indirect application is in other relevant technical field, all including on the same reason the utility model discloses an in the patent protection scope.

The names of the parts denoted by the reference numerals above are as follows:

the valve comprises a valve body 1, a ball body 2, a valve seat 3, a valve cover 4, a locking part 5, an outer pressure ring 6, a blocking piece 7, a valve rod 8, a pressing plate 9, a screw 10, a push block 11, a second step 12, a first step 13, a first groove 14, a second groove 15, an opening and closing stroke slot hole 16, a handle 17, a third step 18, a clamping part 19 and an unlocking key 20.

Claims (10)

1. The utility model provides a self-locking valve, includes the valve rod, and the driven valve rod pivoted fastener is connected at the valve rod top, its characterized in that: the valve rod and the clamping piece are provided with self-locking mechanisms, each self-locking mechanism comprises an opening and closing stroke slot hole formed in the clamping piece, a pushing block fixed on the valve rod and capable of moving relatively in the opening and closing stroke slot hole, and clamping grooves which are formed in the clamping piece and the valve rod respectively and matched with each other; the clamping piece is connected with the valve rod in a rotating fit mode.

2. The self-locking valve of claim 1, wherein: the self-locking mechanism is an off-position self-locking mechanism, and when the valve rod is in an on-position state, the push block is positioned at the starting end of the opening and closing stroke slotted hole; the opening and closing stroke slot hole is arc-shaped and coaxial with the valve rod.

3. The self-locking valve of claim 1, wherein: the self-locking mechanism is an open-position self-locking mechanism, and when the valve rod is in an off-position state, the push block is positioned at the tail end of the opening and closing stroke slotted hole; the opening and closing stroke slot hole is arc-shaped and coaxial with the valve rod.

4. The self-locking valve of claim 1, wherein: and the clamping piece is fixedly connected with a handle.

5. The self-locking valve of claim 1, wherein: the clamping groove respectively extends the clamping piece and the valve rod to be axially arranged on the rotating surface.

6. The self-locking valve of claim 1, wherein: the outer cover of valve rod is equipped with the valve rod sealing joint of coaxial setting, is provided with stop gear on valve rod sealing joint and the fastener.

7. The self-locking valve of claim 6, wherein: the limiting mechanism comprises a locking part formed at the top of the valve rod sealing joint and a clamping part formed at the bottom of the clamping piece.

8. The self-locking valve of claim 7, wherein: the locking part and the clamping part are respectively provided with two step surfaces with different heights and are mutually clamped and matched; the distance between the two steps of the locking part is matched with the opening and closing stroke of the clamping piece, and a blocking piece which limits the movement between the two steps of the locking part is fixed on the valve rod.

9. The self-locking valve of claim 1, wherein: the top of valve rod can be dismantled fixedly connected with fastener and lock the subassembly, and fastener locks the subassembly and includes the screw, and supports the clamp plate that presses at the valve rod top with the fastener.

10. A self-locking valve system comprising the self-locking valve of any one of claims 1 to 9, further comprising an unlocking key, the unlocking key engaging with the latching groove.

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