CN114893612A

CN114893612A - Stainless steel nuclear-grade straight-stroke piston type pneumatic actuator

Info

Publication number: CN114893612A
Application number: CN202210399263.9A
Authority: CN
Inventors: 苏仕平; 席陆军; 张莉; 闫兵
Original assignee: Shanghai NoFive Valve Factory Co ltd
Current assignee: Shanghai NoFive Valve Factory Co ltd
Priority date: 2022-04-15
Filing date: 2022-04-15
Publication date: 2022-08-12

Abstract

The invention discloses a stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism which comprises a cylinder body, an upper cylinder cover, a lower cylinder cover, a piston rod, a split nut device, a hand wheel and a position indicating device, wherein the upper cylinder cover is in mortise-tenon connection with a first end of the cylinder body, the lower cylinder cover is in mortise-tenon connection with a second end of the cylinder body, the piston rod penetrates through the upper cylinder cover, the piston and the lower cylinder cover, the split nut device is circumferentially arranged on the part, close to the upper cylinder cover, of the piston rod, the part, close to the upper cylinder cover, of the piston rod is circumferentially arranged, the end, far away from the upper cylinder cover, of the split nut device is circumferentially connected with the hand wheel, and the end, close to the upper cylinder cover, of the piston rod is also connected with the position indicating device. The invention solves the problem of stress deformation under the working conditions of high temperature and earthquake, avoids the problem that the screw cannot be disassembled due to thread seizure, and saves the arrangement space.

Description

Stainless steel nuclear-grade straight-stroke piston type pneumatic actuator

Technical Field

The invention relates to the technical field of valve actuating mechanisms, in particular to a stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism.

Background

In pneumatic systems, the transmission that converts the energy of compressed air into mechanical energy to achieve linear, rotational or oscillatory motion is referred to as a pneumatic actuator. The pneumatic actuator mainly comprises three forms of a film type, a cylinder type and a swing type, and has the advantages of simple structure, low manufacturing cost, convenient maintenance, low working pressure, high movement speed and convenient adjustment of output force and speed.

In recent years, pneumatic technology has been developed extremely rapidly, combining the many advantages of electronic technology, hydraulic, mechanical, and electrical transmissions. With the rapid development of modern industrial automation, the automatic control of instrument automation equipment is widely applied in pipeline control systems. In case of emergency such as short-term power failure on the pipeline site, a pneumatic actuating mechanism for manual and pneumatic switching is selected, so that the operating handle can be conveniently rotated when the power failure or the power failure of the electromagnetic valve and the control circuit thereof occurs on the site, the switching from the pneumatic operation mode to the manual operation mode can be rapidly carried out, the normal operation of a line is ensured, and accidents are avoided.

Nuclear grade valves used in nuclear power systems require that all parts be stainless steel due to the need for pneumatic actuators to operate under conditions of certain radioactivity levels and corrosive environments, while requiring that rapid maintenance, replacement and disassembly be met to reduce the exposure dose to maintenance personnel in view of the above-mentioned special environments. But the cylinder structure on the existing market is mainly for the cylinder body with go up the lower cylinder cap pull rod and be connected, when pull rod and nut all are stainless steel, the condition that the pull rod was stung with the nut appears easily.

Therefore, those skilled in the art are devoted to provide a stainless steel nuclear-grade straight-stroke piston type pneumatic actuator, which realizes manual switching through clutch type manual operation and a pull-rod-free open-loop mortise-tenon structure, and can prevent misoperation during manual operation.

Disclosure of Invention

In view of the defects in the prior art, the technical problem to be solved by the present invention is how to provide a pneumatic actuator capable of quickly realizing manual switching and preventing manual misoperation.

In order to achieve the purpose, the invention provides a stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism which comprises a cylinder body, an upper cylinder cover, a lower cylinder cover, a piston rod, a split nut device, a hand wheel and a position indicating device, wherein the upper cylinder cover is in mortise-tenon connection with a first end of the cylinder body, the lower cylinder cover is in mortise-tenon connection with a second end of the cylinder body, the piston is positioned in the cylinder body, the piston rod penetrates through the upper cylinder cover, the piston and the lower cylinder cover, the piston is fixedly connected with the piston rod, the part of the piston rod, which is positioned outside the cylinder body and close to the upper cylinder cover, is provided with an external thread, the part of the piston rod, which is positioned outside the cylinder body and close to the upper cylinder cover, is circumferentially provided with the split nut device, the end part of the split nut device, which is far away from the upper cylinder cover, is circumferentially connected with the hand wheel, and the split nut device is configured to be capable of being meshed with or separated from the external thread of the piston rod, the end part of the piston rod, which is close to the upper cylinder cover, is also connected with the position indicating device, and the position indicating device is configured to indicate the stroke position of the piston rod.

Furthermore, the split nut device comprises a thrust needle bearing, a transmission sleeve, a locking rod, a spring seat, a spring, a split rod, a split disc, a split nut and four split rings, wherein the transmission sleeve is connected with the upper cylinder cover through the thrust needle bearing, the locking rod is arranged at two ends of the circumferential direction of the piston rod, the spring seat is arranged at one end of the locking rod, the transmission sleeve is provided with a locking rod hole for accommodating the spring seat, the spring seat is arranged between the spring seat and the split disc, the split disc is connected with the split nut, the four split rings are arranged at the end part of the split disc, and the hand wheel is sleeved on the four split rings.

The piston rod is sleeved with the upper bushing, and the upper bushing is embedded into the upper cylinder cover and the transmission sleeve.

Further, position indication device includes indicator rod, indicator, closes and indicates piece, opens and indicates piece, safety cover, the indicator rod is fixed the tip of piston rod, the indicator is established on the indicator rod, the safety cover is established the outside of indicator rod, close indicate the piece with it establishes to open the indicator block on the safety cover.

Further, a saddle clamp quick-release anti-rotation member is connected to the end, close to the lower cylinder cover, of the piston rod, and the other end of the saddle clamp quick-release anti-rotation member is configured to be connected with a valve rod.

Further, the piston rod is rotatably connected with the saddle clamp quick-release anti-rotation component, and the valve rod is fixedly connected with the saddle clamp quick-release anti-rotation component.

Further, a support is arranged on the outer side of the saddle clamp anti-rotating component, and the valve rod penetrates through the support.

Further, the piston rod is located be equipped with the nut between the piston with the lower cylinder cap, the nut with the piston laminating.

Further, sealing rings are respectively arranged between the piston and the inner wall of the cylinder body, between the upper cylinder cover and the inner wall of the cylinder body, and between the lower cylinder cover and the inner wall of the cylinder body.

Furthermore, open rings are arranged in the mortise and tenon structures of the upper cylinder cover and the cylinder body and the mortise and tenon structures of the lower cylinder cover and the cylinder body.

The invention has at least the following beneficial technical effects:

1. according to the stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism provided by the invention, the cylinder body and the cylinder cover are connected by adopting the tenon-and-mortise structure, compared with a pull rod connecting mechanism, the problem of stress deformation under high-temperature conditions, earthquake working conditions and other occasions is solved, the problem that the pull rod cannot be disassembled due to thread seizure is avoided, and meanwhile, the safety accident caused by corrosion and fracture of the pull rod in a corrosion environment is also avoided. The mortise and tenon connection enables the device to be more compact, and the arrangement space is saved.

2. According to the stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism, pneumatic and manual switching is achieved through the split nut device, opening and closing are achieved in the radial direction of the piston rod, the height of the pneumatic actuating mechanism is reduced, and manual switching is safe and convenient.

3. According to the stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism, the position indicating device can adjust and indicate according to the formation of different equipment, errors in the assembling and production processes can be finely adjusted, and the problem of inaccurate indication is solved.

4. The stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism provided by the invention adopts an integrated piston rod design, ensures the accuracy of an output force value and the formation of a piston, can detach the components in the cylinder at one time, is convenient for replacing a sealing element and overhauling the components in the cylinder, and saves the maintenance time.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a schematic structural diagram of a stainless steel nuclear-grade straight-stroke piston type pneumatic actuator provided by an embodiment of the invention;

FIG. 2 is a three-dimensional schematic diagram of a stainless steel nuclear-grade straight-stroke piston type pneumatic actuator provided by the embodiment of the invention;

fig. 3 is a schematic view of the overall structure of a split nut device according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a switching process of the split nut device according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a position indicating device according to an embodiment of the present invention.

In the figure, the position of the upper end of the main shaft,

1-cylinder body, 2-piston, 31-upper cylinder cover, 32-lower cylinder cover, 4-open ring, 5-open-close nut, 6-open-close nut operating mechanism, 62-open-close rod, 63-spring, 64-spring seat, 65-locking rod, 7-hand wheel, 8-four open ring, 9-indicator, 10-position indicating device, 101-open indicating block, 102-close indicating block, 103-screw, 104-indicating rod, 105-protective cover, 11-support, 12-saddle clamp quick-release anti-rotation component, 13-piston rod, 14-transmission sleeve, 15-adjusting sleeve, 16-open-close disk, 17-end cover, 18-thrust needle bearing, 19-upper bush, 20-pressure spring and 21-nut.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

The invention provides a stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism, which comprises a cylinder body 1, a piston 2, an upper cylinder cover 31, a lower cylinder cover 32, a piston rod 13, a hand wheel 7, saddle clamp quick-release anti-rotation components 12, a split nut device and a position indicating device 10, and is shown in figures 1 and 2. The cylinder body 1, the upper cylinder cover 31 and the lower cylinder cover 32 are connected to form a closed cylinder, the piston 2 is located in the cylinder body 1, the piston rod 13 sequentially penetrates through the upper cylinder cover 31, the piston 2 and the lower cylinder cover 32, and the piston 2 is fixed on the piston rod 13, so that the piston 2 moves up and down along with the piston rod 13.

In the invention, the upper cylinder cover 31 and the cylinder body 1 and the lower cylinder cover 32 and the cylinder body 1 are in mortise and tenon connection, so that the structure of the cylinder is compact, the occupied space is reduced, the deformation in the vibration process is reduced under the anti-seismic working condition, the seizure phenomenon existing in threaded connection is avoided, and the disassembly and the maintenance are easy. Specifically, as shown in detail drawing I in fig. 1, a diameter-variable structure matched with the inner wall of the cylinder body 1 is arranged at a position near the middle of the upper cylinder cover 31 and the lower cylinder cover 32 in the circumferential direction, so that the upper cylinder cover 31 and the lower cylinder cover 32 are attached to the cylinder body 1; as shown in detail fig. ii, the open ring 4 is provided at the end portions of the upper cylinder head 31 and the lower cylinder head 32 away from the piston 2, notches are formed in the inner wall of the cylinder 1 and the edges of the upper cylinder head 31 and the lower cylinder head 32, the open ring 4 is provided in the notches, the upper cylinder head 31 and the cylinder 1 are engaged with each other, and the upper cylinder head 31 and the lower cylinder head 32 are detached from the cylinder 1 by removing the open ring 4. As shown in detail fig. ii, a bead is further disposed on the outer side of the open ring 4 to realize the encapsulation of the split portion.

In order to improve the sealing effect, sealing rings are respectively arranged between the upper cylinder cover 31 and the inner wall of the cylinder body 1, between the lower cylinder cover 32 and the inner wall of the cylinder body 1, and between the piston 2 and the inner wall of the cylinder body 1, so that the driving of the piston 2 by gas is ensured.

The piston rod 13 may be provided with an external thread in sections as required for connection with a nut. In the embodiment, the part of the piston rod 13, which is positioned between the piston 2 and the lower cylinder cover 32, is provided with the external thread, the nut 21 is meshed on the external thread, the nut 21 is attached to the piston 2, and the piston 2 can be limited by the nut 21, so that the damage to the cylinder caused by the large moving distance of the piston 2 is avoided; when the valve is disassembled, the piston 2 can be prevented from sliding off the piston rod 13.

The end part of the piston rod 13 close to the lower cylinder cover 32 is connected with a saddle-shaped clamp quick-release anti-rotation component 12, the other side of the saddle-shaped clamp quick-release anti-rotation component 12 is connected with a valve rod of the valve, and the piston rod 13 is connected with the valve rod through the saddle-shaped clamp quick-release anti-rotation component 12. A support 11 is arranged on the outer side of the saddle clamp quick-release anti-rotation component 12, the saddle clamp quick-release anti-rotation component 12 is protected through the support 11, and the valve rod penetrates through the support 11.

In this embodiment, the saddle clamp quick-release anti-rotation member 12 is a U-shaped structure, one of two sides of the U-shaped structure is rotatably connected to the end of the piston rod 13, specifically, a hole may be formed in the side, and a groove and a boss are circumferentially disposed on the piston rod 13 to match the groove with the hole, so that the piston rod 13 can rotate relative to the side and the axial movement of the piston rod 13 relative to the side is restricted. The valve rod is fixedly connected with the other side edge of the U shape, and specifically can be in bolt connection, so that the valve rod can be prevented from rotating and can be quickly disassembled and assembled through the saddle clamp quick-release anti-rotation component 12.

The split nut device is used for realizing the switching between manual operation and pneumatic operation of the pneumatic actuating mechanism, the split nut device is arranged on one side of the piston rod 13, which is positioned outside the upper cylinder cover 31, and the corresponding piston rod 13 is provided with external threads. The main components of the split nut device are a split nut operating mechanism 6, a split nut 5 and a split disc 16, when the split nut 5 is meshed with the thread of the piston rod 13, manual operation on the actuating mechanism can be achieved, and when the split nut 5 is separated from the thread of the piston rod 13, pneumatic control is carried out on the actuating mechanism.

Specifically, as shown in fig. 3 and 4, the split nut device is composed of a thrust needle bearing 18, a transmission sleeve 14, a locking rod 65, a spring seat 64, a spring 63, a split rod 62, a split disc 16, a split nut 5 and a four-open ring 8. The driving sleeve 14 and the upper cylinder cover 31 are connected by a needle thrust bearing 18 to reduce the friction force between the driving sleeve 14 and the upper cylinder cover 31. The locking rod 65 and the opening and closing rod 62 are arranged at two circumferential ends of the piston rod 13, a spring seat 64 is arranged at one end of the locking rod 65, and a locking rod hole is formed in the transmission sleeve 14 to accommodate the spring seat 64. A spring 63 is arranged between the spring seat 64 and the opening and closing disc 16, and the opening and closing disc 16 is connected with the opening and closing nut 5. When the spring seat 64 is positioned in the locking rod hole, the opening and closing rod 62 is rotated anticlockwise for a certain angle to drive the opening and closing disc 16 to enable the opening and closing nut 5 to be disengaged from the piston rod 13, and then the actuating mechanism is switched to pneumatic operation; when the spring seat 64 is separated from the locking rod hole, the opening and closing rod 62 is rotated clockwise by the same angle to drive the opening and closing disc 16 to enable the opening and closing nut 5 to be meshed with the piston rod 13, and then the actuating mechanism is switched to manual operation.

The end of the opening and closing disc 16 is also provided with a four-open ring 8 which can limit the axial movement of the opening and closing disc 16 along the piston rod 13. The hand wheel 7 is sleeved on the four-open ring 8, and the piston rod 13 can be lifted and descended by operating the hand wheel 7 in a manual operation mode.

As shown in fig. 2, an adjusting sleeve 15 is further arranged on the outer side of the transmission sleeve 14, an end cover 17 is further arranged on the outer side of the four-open ring 8, and the adjusting sleeve 15 and the end cover 17 encapsulate the whole split nut device, so that compact connection of the device is realized.

When the actuating mechanism is switched to manual operation, the hand wheel 7 is rotated to drive the split nut device to integrally rotate, the split nut 5 rotates relative to the piston rod 13, and the piston rod 13 is driven by the split nut 5 to lift.

In order to facilitate the lifting of the piston rod 13, the pneumatic actuator of the present invention is further provided with an upper bushing 19, wherein the upper bushing 19 is sleeved on the piston rod 13 and is embedded into the upper cylinder cover 31 and the transmission sleeve 14. To seal the cylinder, a seal ring is also provided between the upper liner 19 and the upper cylinder head 31.

As shown in fig. 5, the position indicating device 10 is used for indicating the stroke of the piston rod 13, and specifically comprises an indicating rod 104, an indicator 9, a closing indicating block 102, an opening indicating block 101, and a protective cover 105, wherein the indicating rod 104 is fixed at the end of the piston rod 13, the indicator 9 is arranged on the indicating rod 104, the protective cover 105 is arranged outside the indicating rod 104, the closing indicating block 102 and the opening indicating block 101 are arranged on the protective cover 105, and the closing indicating block 102 and the opening indicating block 101 are fixed with the protective cover 105 through screws 103. The position indicating device 10 is an adjustable mechanism, the indicating height can be adjusted through the adjusting indicator 9, the stroke range of the equipment can be adjusted through the opening indicating block 101 and the closing indicating block 102, errors in the assembling and production processes are finely adjusted, the movement caused by external vibration is prevented through the screw 103, and the problem of inaccurate indication is solved.

The straight stroke piston type pneumatic actuating mechanism can be a single-action actuating mechanism or a double-action actuating mechanism. When the actuator is a single-action actuator, the actuator is divided into a normally closed type and a normally open type; as shown in fig. 1, the piston rod 13 between the piston 2 and the upper cylinder cover 31 is covered with a compression spring 20; when the piston is in a normally open type, a pressure spring 20 is sleeved on the piston rod 13 between the piston 2 and the lower cylinder cover 32; when the piston 2 moves up and down along with the piston rod 13, the pressure spring 20 can provide restoring force for the piston 2; accordingly, an intake or exhaust port is provided in the lower cylinder head 32 and the upper cylinder head 31. When the double-acting actuating mechanism is adopted, springs are not needed on two sides of the piston 2, correspondingly, air inlets are formed in the upper cylinder cover 31 and the lower cylinder cover 32, the upper cylinder cover and the lower cylinder cover alternately advance and exhaust to achieve up-and-down movement of the piston 2, and the air inlets can also be used for exhausting.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection determined by the claims.

Claims

1. A stainless steel nuclear-grade straight-stroke piston type pneumatic actuating mechanism is characterized by comprising a cylinder body, an upper cylinder cover, a lower cylinder cover, a piston rod, a split nut device, a hand wheel and a position indicating device, wherein the upper cylinder cover is in mortise-tenon connection with a first end of the cylinder body, the lower cylinder cover is in mortise-tenon connection with a second end of the cylinder body, the piston is located in the cylinder body, the piston rod penetrates through the upper cylinder cover, the piston and the lower cylinder cover, the piston is fixedly connected with the piston rod, the part, close to the upper cylinder cover, of the piston rod is located outside the cylinder body is provided with external threads, the split nut device is circumferentially arranged on the part, close to the upper cylinder cover, of the piston rod, the end part, far away from the upper cylinder cover, of the split nut device is circumferentially connected with the hand wheel, and the split nut device is configured to be capable of being meshed with or separated from the external threads of the piston rod, the end part of the piston rod, which is close to the upper cylinder cover, is also connected with the position indicating device, and the position indicating device is configured to indicate the stroke position of the piston rod.

2. The stainless steel nuclear-grade straight-stroke piston type pneumatic actuator as claimed in claim 1, wherein the split nut device comprises a thrust needle bearing, a transmission sleeve, a locking rod, a spring seat, a spring, a split rod, a split disc, a split nut and four open rings, the transmission sleeve is connected with the upper cylinder cover through the thrust needle bearing, the locking rod and the split rod are arranged at two circumferential ends of the piston rod, the spring seat is arranged at one end of the locking rod, the transmission sleeve is provided with a locking rod hole for accommodating the spring seat, the spring is arranged between the spring seat and the split disc, the split disc is connected with the split nut, the four open rings are further arranged at the end parts of the split disc, and the hand wheel is sleeved on the four open rings.

3. The stainless steel nuclear grade straight stroke piston pneumatic actuator of claim 2 further comprising an upper bushing, said upper bushing sleeved on said piston rod and embedded in said upper cylinder head and said drive sleeve.

4. The stainless steel nuclear grade straight stroke piston type pneumatic actuator as claimed in claim 1, wherein said position indicating means includes an indicating rod fixed to an end of said piston rod, an indicator provided on said indicating rod, a close indicating block, an open indicating block, and a protective cover provided on an outer side of said indicating rod, said close indicating block and said open indicating block being provided on said protective cover.

5. The stainless steel nuclear grade straight piston pneumatic actuator of claim 1 wherein the end of the piston rod near the lower cylinder head has a saddle quick release anti-rotation member attached to it, the other end of the saddle quick release anti-rotation member being configured to attach to a valve stem.

6. The stainless steel nuclear grade straight piston pneumatic actuator of claim 5 wherein said piston rod is rotatably connected to said saddle quick release anti-rotation member and said valve stem is fixedly connected to said saddle quick release anti-rotation member.

7. The stainless steel nuclear grade straight stroke piston pneumatic actuator of claim 5 wherein said saddle anti-rotation member is further provided with a bracket on the outside thereof through which said valve stem passes.

8. The stainless steel nuclear grade straight piston pneumatic actuator of claim 1 wherein a nut is provided on said piston rod between said piston and said lower cylinder head, said nut engaging said piston.

9. The stainless steel nuclear grade straight stroke piston type pneumatic actuator as claimed in claim 1, wherein sealing rings are respectively provided between the piston and the inner wall of the cylinder body, between the upper cylinder cover and the inner wall of the cylinder body, and between the lower cylinder cover and the inner wall of the cylinder body.

10. The stainless steel nuclear grade straight stroke piston type pneumatic actuator as claimed in claim 1, wherein the mortise and tenon structures of the upper cylinder cover and the cylinder body and the mortise and tenon structures of the lower cylinder cover and the cylinder body are provided with open rings.