Limit switch for valve position detection

Abstract

The invention relates to the technical field of valve position detection, in particular to a limit switch for valve position detection, which comprises an action unit, an overtravel unit, a reset unit, a shell and a microswitch, one end of the action unit is rotatably connected with the shell and is provided with a groove, one end of the overtravel unit is abutted against the groove, and the other end of the overtravel unit is abutted against the microswitch. The reset unit is connected to the other end of the overtravel unit in a sleeved mode, the microswitch is fixedly connected with the shell, and the other end of the overtravel unit abuts against or is separated from the microswitch. When the valve is opened or closed, the action unit is driven to move, so that the over-travel unit is triggered, the over-travel unit moves to trigger the microswitch, and then a displacement signal is converted into a switching value electric signal to be transmitted. By arranging the over-travel unit, when the moving distance of the over-travel unit exceeds the triggering travel of the microswitch, the over-travel unit can protect the microswitch, so that the service life of the limit switch is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of valve position detection, and in particular to a limit switch used for valve position detection. Background Art

[0002] With the advancement of globalization and the continuous development of industrialization, people's demand for energy is also increasing. The nuclear power industry is developing rapidly, and the requirements for the use of limit switches for nuclear power valve accessories are also increasing. During use, failure of the limit switch will affect the normal operation of the unit, and may even cause shutdown. Therefore, the performance stability and reliability of the limit switch are very important.

[0003] Since the research foundation of nuclear power valve accessories in China is relatively weak, most nuclear power plants currently use foreign products. The current limit switches cannot accurately determine the position of the valve due to small rotation stroke, short difference and stroke, wear of moving parts causing misalignment, poor repeatability, and the actuator needs to bear additional torque, which leads to product scrapping and equipment shutdown, affecting the normal operation of nuclear power plants. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a limit switch for valve position detection with a prolonged service life.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a limit switch for valve position detection, comprising an action unit, an overtravel unit, a reset unit, a shell and a micro switch, one end of the action unit is rotatably connected to the shell and has an arc surface, one end of the overtravel unit abuts the arc surface, the reset unit is sleeved on the other end of the overtravel unit, two ends of the reset unit abut against the shell and the overtravel unit respectively, the micro switch is fixedly connected to the shell, and the other end of the overtravel unit abuts against or separates from the micro switch.

[0006] The beneficial effects of the present invention are as follows: when the valve is opened or closed, the action unit is driven to move, thereby triggering the overtravel unit. The movement of the overtravel unit triggers the microswitch and compresses the reset unit at the same time. The microswitch converts the displacement signal into a switch electrical signal and transmits it. When the action unit is not subjected to force, the reset unit will reset under the action of the accumulated force and then push the overtravel unit and the action unit to reset. After the microswitch is triggered, since the movable part of the valve has a stroke, when the movable part of the valve continues to move, when the moving distance of the overtravel unit exceeds the triggering stroke of the microswitch, the overtravel unit will protect the microswitch, thereby increasing the service life of the limit switch.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Further, the overtravel unit includes a sliding tube, a center rod, a second spring and a washer, one end of the sliding tube abuts against the arc surface, the other end of the sliding tube has a countersunk hole, the second spring is located in the countersunk hole, the washer is fixedly connected to the other end of the sliding tube, the side wall of the center rod is provided with a step, the step abuts against the second spring, the step abuts against or separates from the washer, and one end of the center rod abuts against or separates from one end of the micro switch.

[0009] The beneficial effect of adopting the above further scheme is: by setting the slide tube, when the action unit is subjected to force, one end of the slide tube abuts against the arc surface, thereby driving the overtravel unit to move as a whole, and by setting the center rod and the washer, the center rod and the washer cooperate, the center rod is used to trigger the micro switch, and the washer further limits the movement of the center rod in the direction of the micro switch. With the setting of the second spring, after the micro switch is triggered, the shaft continues to push the slide tube to move, and when the movement distance of the overtravel unit exceeds the triggering stroke of the micro switch, the second spring is further compressed, so that the center rod moves relative to the slide tube in the direction away from the micro switch, thereby protecting the micro switch.

[0010] Furthermore, the step is located in the middle of the center rod, and the second set of springs is arranged at the other end of the center rod.

[0011] The beneficial effect of adopting the above further scheme is: by arranging the second spring sleeve on the other end of the center rod, the second spring guides the movement of the center rod, so that the center rod and the second spring cooperate with each other and smoothly drive the center rod and the micro switch to abut or move away.

[0012] Furthermore, the action unit includes a rocker arm assembly and a shaft assembly, one end of the rocker arm assembly is fixedly connected to one end of the shaft assembly, and the other end of the shaft assembly is rotatably connected to the housing and has the arc surface.

[0013] The beneficial effect of adopting the above further scheme is: by setting a rocker arm assembly, when the valve position changes, the rocker arm assembly is driven to rotate, the rocker arm assembly drives the shaft assembly to rotate, and then drives the overtravel unit to move in the direction of the micro switch, thereby triggering the micro switch.

[0014] Furthermore, the shaft assembly includes a shaft, a socket and a second locking component, a third through hole is provided at one end of the rocker arm assembly, a fourth through hole is provided on the socket, one end of the shaft passes through the fourth through hole and the third through hole, and is locked and fixed by the second locking component.

[0015] The beneficial effect of adopting the above further solution is that the setting of the clamping seat provides support and limit for one end of the rocker assembly, limiting the rocker assembly from rotating freely around the rotating shaft. The second locking component fixedly connects the rotating shaft and the rocker assembly, so that when the rocker assembly is subjected to force, it can smoothly drive the rotating shaft to rotate and then drive the overtravel unit to move, thereby triggering the micro switch.

[0016] Furthermore, a groove is formed at the other end of the rotating shaft, and a groove wall of the groove is the arc surface.

[0017] The beneficial effect of adopting the above further solution is: by providing a groove on the rotating shaft and setting the groove wall of the groove as an arc surface, the overtravel unit is driven to move when the rotating shaft rotates.

[0018] Furthermore, the rocker arm assembly includes a rocker arm and a roller, one end of the rocker arm is fixedly connected to one end of the rotating shaft assembly, and the roller is rotatably connected to the other end of the rocker arm.

[0019] The beneficial effect of adopting the above further solution is that when the valve switches between the open position and the closed position, the roller is driven to roll, thereby driving the rocker arm to rotate, and then driving the shaft assembly to rotate, and the rotation of the shaft assembly further drives the overtravel unit to move, thereby triggering the micro switch. The setting of the roller can also reduce the friction between the rocker arm unit and the valve parts, thereby improving the adaptability and service life of the limit switch.

[0020] Furthermore, the reset unit is spring one.

[0021] The beneficial effect of adopting the above further scheme is: when the valve is opened or closed, the action unit is driven to move, and the movement of the action unit in turn drives the overtravel unit to move. At this time, spring 1 generates accumulated force while the overtravel unit moves toward the direction of the micro switch, and when the action unit is not subjected to force, spring 1 resets under the action of the accumulated force, thereby driving the overtravel unit and the action unit to reset, and wait for the next force and action.

[0022] Further, the shell includes a first section shell and a second section shell, the second section shell is cylindrical, the first section shell includes a first straight section and a second straight section, one end of the first straight section is connected and communicated with one end of the second straight section, the axis of the first straight section and the axis of the second straight section have an angle, one end of the second section shell is fixedly connected to the other end of the second straight section, the action unit is rotatably installed in the first straight section, the overtravel unit is slidably installed in the second straight section, and the micro switch is fixed in the second section shell.

[0023] The beneficial effects of adopting the above further scheme are: the setting of the first section shell and the second section shell facilitates the assembly of its internal structure; the setting of the first section shell provides movement space for the action unit and the overtravel, and guides the activity, and the second section shell provides a placement space for the micro switch and protects it.

[0024] Furthermore, it also includes potting glue and a cable, one end of the cable is fixedly connected to the other end of the micro switch, and the potting glue is filled in the gap between the cable and the second section shell.

[0025] The beneficial effect of adopting the above further scheme is: by connecting the cable and the micro switch, the signal of valve opening or closing can be transmitted to the corresponding equipment through the cable; and the potting glue is filled in the other end of the second section shell for sealing, so as to prevent the contacts of the micro switch from being oxidized and causing damage to the micro switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A cross-sectional view of a limit switch for valve position detection according to the present invention; Figure 2 A schematic diagram of an overtravel unit of a limit switch for valve position detection according to the present invention; Figure 3 It is a schematic diagram of the rotating shaft structure of a limit switch for valve position detection according to the present invention; Figure 4 The figure is a schematic diagram of the overall structure of a limit switch for valve position detection according to the present invention.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 100, action unit; 110, rocker arm assembly; 111, rocker arm; 112, roller; 120, shaft assembly; 121, shaft; 122, holder; 123, first sealing groove; 124, first sealing ring; 200, overtravel unit; 210, slide tube; 220, center rod; 221, step; 230, spring 2; 240, gasket; 300, reset unit; 10, housing; 11, first section housing; 12, second section housing; 20, micro switch; 30, potting glue; 40, cable; 50, groove. DETAILED DESCRIPTION

[0028] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0029] like Figure 1-Figure 4As shown, this embodiment provides a limit switch for valve position detection, including an action unit 100, an overtravel unit 200, a reset unit 300, a shell 10 and a micro switch 20, one end of the action unit 100 is rotatably connected to the shell 10 and has a groove 50, one end of the overtravel unit 200 abuts against the groove 50, the reset unit 300 is sleeved on the other end of the overtravel unit 200, two ends of the reset unit 300 abut against the shell 10 and the overtravel unit 200 respectively, the micro switch 20 is fixedly connected to the shell 10, and the other end of the overtravel unit 200 abuts against or separates from the micro switch 20.

[0030] When the valve is opened or closed, the movable part of the valve applies force to the action unit, thereby driving the action unit 100 to move, and at the same time triggering the overtravel unit 200. The overtravel unit 200 moves to trigger the micro switch 20 and compress the reset unit 300. The micro switch 20 converts the displacement signal into a switch electrical signal and transmits it. When the action unit 100 is not subjected to force, the reset unit 300 resets under the action of the accumulated force and then pushes the overtravel unit 200 to move, thereby driving the overtravel unit 200 and the action unit 100 to reset. In the process of opening or closing the valve, after the micro switch 20 is triggered, since the movable part of the valve and the power unit 100 are in contact with each other for a certain stroke, when the movable part of the valve continues to move, when the moving distance of the overtravel unit 200 exceeds the triggering stroke of the micro switch 20, the overtravel unit 200 will protect the micro switch 20, thereby increasing the service life of the limit switch.

[0031] On the basis of any of the above schemes, the overtravel unit 200 includes a slide tube 210, a center rod 220, a spring 230 and a washer 240, one end of the slide tube 210 abuts against the groove 50, the other end of the slide tube 210 has a countersunk hole, the spring 230 is located in the countersunk hole, the washer 240 is fixedly connected to the other end of the slide tube 210, the side wall of the center rod 220 is provided with a step 221, the step 221 abuts against the spring 230, the step 221 abuts against or separates from the washer 240, and one end of the center rod 220 abuts against or separates from one end of the micro switch 20.

[0032] By setting the slide tube 210, when the action unit 100 is subjected to force, one end of the slide tube 210 abuts against the groove 50, thereby driving the overtravel unit 200 to move as a whole. By setting the center rod 220 and the washer 240, the center rod 220 and the washer 240 cooperate with each other, the center rod 220 is used to trigger the micro switch 20, and the washer 240 further limits the movement of the center rod 220 in the direction of the micro switch 20. The opening of the valve has a certain stroke. After the micro switch 20 is triggered, the movement of the action unit 100 will continue to push the slide tube 210 to move. When the moving distance of the overtravel unit 200 exceeds the triggering stroke of the micro switch 20, the spring 230 is further compressed, so that the center rod 220 moves relative to the slide tube 210 in the direction away from the micro switch 20, thereby protecting the micro switch 20.

[0033] Specifically, the washer 240 has a fifth through hole, and one end of the center rod 220 passes through the fifth through hole.

[0034] Specifically, the sliding tube 210 includes a sleeve section and an abutment section, the abutment section has a countersunk hole, the sleeve section has a sixth through hole, one end of the abutment section abuts against the groove 50, the other end of the abutment section is fixedly connected to one end of the sleeve section, the countersunk hole is connected to the sixth through hole, and the outer diameter of the abutment section is larger than the outer diameter of the sleeve section.

[0035] In one specific example, one end of the reset unit 300 abuts against the housing 10 , and the other end of the reset unit 300 abuts against the other end of the sleeve segment.

[0036] On the basis of any of the above solutions, the step 221 is located in the middle of the center rod 220 , and the second spring 230 is sleeved on the other end of the center rod 220 .

[0037] By sleeved the second spring 230 on the other end of the center rod 220, the second spring 230 guides the movement of the center rod 220, so that the center rod 220 and the second spring 230 cooperate with each other and smoothly drive the center rod 220 and the micro switch 20 to abut or move away.

[0038] Specifically, the two ends of the central rod 220 are two sections of cylinders.

[0039] Based on any of the above schemes, the action unit 100 includes a rocker arm assembly 110 and a shaft assembly 120, one end of the rocker arm assembly 110 is fixedly connected to one end of the shaft assembly 120, and the other end of the shaft assembly 120 is rotatably connected to the housing 10 and has the groove 50.

[0040] By setting the rocker arm assembly 110 , when the valve position changes, the rocker arm assembly 110 is driven to rotate, and the rocker arm assembly 110 drives the shaft assembly 120 to rotate, thereby driving the overtravel unit 200 to move toward the direction of the micro switch 20 to trigger the micro switch 20 .

[0041] Based on any of the above schemes, the shaft assembly 120 includes a shaft 121, a socket 122 and a second locking component, one end of the rocker arm assembly 110 is provided with a third through hole, the socket 122 is provided with a fourth through hole, one end of the shaft 121 passes through the fourth through hole and the third through hole, and is locked and fixed by the second locking component.

[0042] The socket 122 is configured to provide support and limit for one end of the rocker arm assembly 110, thereby limiting the rocker arm assembly 110 from rotating freely around the rotating shaft 121. The second locking component fixes the rotating shaft 121 and the rocker arm assembly 110 together, so that when the rocker arm assembly 110 is subjected to force, it can smoothly drive the rotating shaft 121 to rotate and then drive the overtravel unit 200 to move, thereby triggering the micro switch 20.

[0043] Specifically, the second locking component is a nut.

[0044] In a specific embodiment, one end of the rotating shaft 121 is provided with an external thread, and one end of the rotating shaft 121 passes through the fourth through hole and the third through hole and is locked and fixed with a nut. At the same time, a gasket is provided at one end of the nut and the rocker arm assembly 110, thereby increasing the contact area between the nut and the rocker arm assembly 110, reducing pressure, and protecting the rocker arm assembly 110 and the nut.

[0045] Specifically, a first sealing groove 123 is provided in the middle of the rotating shaft 121 , and a first sealing ring 124 is sleeved on the first sealing groove 123 .

[0046] The first sealing groove 123 is provided on the rotating shaft 121 , and the first sealing ring 124 is placed in the first sealing groove 123 , thereby protecting the rotating shaft 121 .

[0047] On the basis of any of the above solutions, a groove 50 is formed at the other end of the rotating shaft 121 , and the groove wall of the groove 50 is a plane.

[0048] The groove 50 is formed on the rotating shaft 121 , and the groove wall of the groove 50 is set to be a plane, so that when the rotating shaft 121 rotates, the over-travel unit 200 is driven to move.

[0049] Based on any of the above schemes, the rocker arm assembly 110 includes a rocker arm 111 and a roller 112 , one end of the rocker arm 111 is fixedly connected to one end of the shaft assembly 120 , and the roller 112 is rotatably connected to the other end of the rocker arm 111 .

[0050] By providing the roller 112, when the valve switches between the open position and the closed position, the roller 112 is driven to roll, thereby driving the rocker arm 111 to rotate, and then driving the shaft assembly 120 to rotate. The rotation of the shaft assembly 120 further drives the overtravel unit 200 to move, thereby triggering the micro switch 20. The provision of the roller 112 can also reduce the friction between the rocker arm assembly 110 and the movable part of the valve, thereby improving the adaptability and service life of the limit switch.

[0051] Specifically, one end of the rocker arm 111 is connected to one end of the rotating shaft assembly 120 via a first locking component. A first through hole is provided at the other end of the rocker arm 111, and a second through hole is provided at the axis of the roller 112. The first through hole and the second through hole are coaxially arranged, and the first locking component passes through the first through hole and the second through hole to connect the rocker arm 111 and the roller 112.

[0052] Optionally, the first locking component is a rivet or a locking bolt.

[0053] Based on any of the above solutions, the reset unit 300 is a spring 1.

[0054] When the valve is opened or closed, the action unit 100 is driven to move, and the movement of the action unit 100 further drives the overtravel unit 200 to move. At this time, the spring 1 generates stored force while the overtravel unit 200 moves toward the direction of the micro switch 20. When the action unit 100 is not subjected to force, the spring 1 is reset under the action of the stored force, thereby driving the overtravel unit 200 and the action unit 100 to reset and wait for the next force and action.

[0055] Alternatively, the reset unit 300 may be other elastic members.

[0056] On the basis of any of the above schemes, the shell 10 includes a first section shell 11 and a second section shell 12, the second section shell 12 is cylindrical, the first section shell 11 includes a first straight section and a second straight section, one end of the first straight section is connected and communicated with one end of the second straight section, the axis of the first straight section and the axis of the second straight section have an angle, one end of the second section shell 12 is fixedly connected to the other end of the second straight section, the action unit 100 is rotatably installed in the first straight section, the overtravel unit 200 is slidably installed in the second straight section, and the micro switch 20 is fixed in the second section shell 12.

[0057] The arrangement of the first shell 11 and the second shell 12 facilitates the assembly of the internal structure thereof; the arrangement of the first shell 11 provides a space for movement of the action unit 100 and the overtravel unit 200 and guides the movement, and the second shell 12 provides a placement space for the micro switch 20 and protects it.

[0058] Specifically, the first straight segment and the second straight segment are not coaxial.

[0059] Specifically, the first straight section is provided with a circular hole; the second straight section is provided with a circular hole or a square hole; the second section shell 12 is provided with a square hole or a circular hole.

[0060] Optionally, the first straight section has an outer shape of a cylinder, a prism or other shapes, the second straight section has an outer shape of a cylinder, a prism or other shapes, and the second section shell 12 has an outer shape of a cylinder, a prism or other shapes.

[0061] In one specific example, the axis of the first straight section is perpendicular to the axis of the second straight section, that is, the angle between the first straight section and the second straight section is 90 degrees. The first straight section and the second straight section are both cylindrical in shape, and are both provided with circular holes, and the rotating shaft 121 is located in the circular holes. The second section shell 12 is in the shape of a regular quadrangular prism, and the cavity of the second section shell 12 is a circular hole at one end and a square hole at the other end. A baffle is provided between the circular hole and the square hole, and a seventh through hole matching the contact of the micro switch 20 is provided in the middle of the baffle. The micro switch 20 is a rectangular parallelepiped, which is just snapped into the square cavity of the second section shell 12.

[0062] Specifically, a first threaded hole is provided at one end of the second straight segment, and the first threaded hole extends from one end to the other end of the second straight segment. A second threaded hole corresponding to the first threaded hole is provided at one end of the second segment shell 12, and the first threaded hole and the second threaded hole are coaxial and their axes are parallel to the axis of the second straight segment.

[0063] Specifically, there are at least two first threaded holes, and correspondingly, there are at least two second threaded holes.

[0064] By providing the first threaded hole and the second threaded hole, the first segment shell 11 and the second segment shell 12 can be fixedly connected by a locking bolt.

[0065] Specifically, a second sealing ring is provided at the connection between one end of the second segment shell 12 and the other end of the second straight segment.

[0066] The provision of the second sealing ring achieves a sealing effect and protects the internal structure of the housing 10 .

[0067] On the basis of any of the above schemes, it also includes a potting glue 30 and a cable 40, wherein the potting glue 30 and the cable 40 are at the other end of the second section shell 12, one end of the cable 40 and the other end of the micro switch 20 are fixedly connected, and the potting glue 30 is filled in the gap between the cable 40 and the second section shell 12.

[0068] By connecting the cable 40 and the micro switch 20, the valve opening or closing signal can be transmitted to the corresponding equipment through the cable 40; and the potting glue 30 is filled in the other end of the second section shell 12 for sealing, thereby avoiding oxidation of the contacts of the micro switch 20, further improving the service life of the limit switch.

[0069] In one of the specific embodiments, a threaded hole is provided on the side wall of the second shell 12, and the limit switch is installed on the action stroke of the valve action component by bolts and gaskets. When the valve is opened or closed, the roller 112 is forced to roll and drive the rocker 111 and the rotating shaft 121 to rotate, thereby driving the overtravel unit 200 to move, and then triggering the micro switch 20, so that the micro switch 20 converts the displacement signal of the valve opening or closing into a switch quantity electrical signal and transmits it to the corresponding device. Because when the valve is opened or closed, the movable part of the valve and the roller 112 have a certain stroke when they abut against each other, when the micro switch 20 is triggered, when the valve continues to move, the micro switch 20 will maintain the signal output, and the slide tube 210 will continue to move in the direction of the micro switch 20, and at the same time, the spring 1 is compressed and stored. When the moving distance of the overtravel unit 200 exceeds the triggering stroke of the micro switch 20, the spring 2 230 will be compressed, and the center rod 220 will remain stationary relative to the micro switch 20, thereby protecting the micro switch 20, thereby increasing the service life of the limit switch. When the roller 112 is not subjected to force, the spring 1 will reset under the action of the accumulated force, and at the same time push the overtravel unit 200 to reset, and then push the rotating shaft 121 and the rocker arm 111 to rotate to the initial state, waiting for the next opening or closing of the valve.

[0070] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "center", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0072] In the present invention, unless otherwise clearly defined and specified, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0074] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0075] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A limit switch for valve position detection, characterized in that: The invention comprises an action unit (100), an overtravel unit (200), a reset unit (300), a housing (10) and a micro switch (20); one end of the action unit (100) is rotatably connected to the housing (10) and has a groove (50); one end of the overtravel unit (200) abuts against the groove (50); the reset unit (300) is sleeved on the other end of the overtravel unit (200); two ends of the reset unit (300) abut against the housing (10) and the overtravel unit (200) respectively; the micro switch (20) is fixedly connected to the housing (10); and the other end of the overtravel unit (200) abuts against or is separated from the micro switch (20).

2. A limit switch for valve position detection according to claim 1, characterized in that: The overtravel unit (200) comprises a slide tube (210), a center rod (220), a second spring (230) and a washer (240); one end of the slide tube (210) abuts against the groove (50); the other end of the slide tube (210) has a countersunk hole; the second spring (230) is located in the countersunk hole; the washer (240) is fixedly connected to the other end of the slide tube (210); a step (221) is provided on the side wall of the center rod (220); the step (221) abuts against the second spring (230); the step (221) abuts against or separates from the washer (240); one end of the center rod (220) abuts against or separates from one end of the micro switch (20).

3. A limit switch for valve position detection according to claim 2, characterized in that: The step (221) is located in the middle of the center rod (220), and the second spring (230) is sleeved on the other end of the center rod (220).

4. A limit switch for valve position detection according to claim 1, characterized in that: The action unit (100) comprises a rocker arm assembly (110) and a rotating shaft assembly (120); one end of the rocker arm assembly (110) is fixedly connected to one end of the rotating shaft assembly (120); the other end of the rotating shaft assembly (120) is rotatably connected to the housing (10) and has the groove (50).

5. A limit switch for valve position detection according to claim 4, characterized in that: The rotating shaft assembly (120) comprises a rotating shaft (121), a clamping seat (122) and a second locking component; one end of the rocker arm assembly (110) is provided with a third through hole, the clamping seat (122) is provided with a fourth through hole, one end of the rotating shaft (121) passes through the fourth through hole and the third through hole, and is locked and fixed by the second locking component.

6. A limit switch for valve position detection according to claim 5, characterized in that: The other end of the rotating shaft (121) is provided with the groove (50), and the groove wall of the groove (50) is a plane.

7. A limit switch for valve position detection according to claim 4, characterized in that: The rocker arm assembly (110) comprises a rocker arm (111) and a roller (112); one end of the rocker arm (111) is fixedly connected to one end of the rotating shaft assembly (120); and the roller (112) is rotatably connected to the other end of the rocker arm (111).

8. A limit switch for valve position detection according to claim 1, characterized in that: The reset unit (300) is a spring.

9. A limit switch for valve position detection according to claim 1, characterized in that: The housing (10) comprises a first section housing (11) and a second section housing (12); the first section housing (11) comprises a first straight section and a second straight section; one end of the first straight section is connected and communicated with one end of the second straight section; an axis of the first straight section and an axis of the second straight section have an included angle; one end of the second section housing (12) is fixedly connected with the other end of the second straight section; the action unit (100) is rotatably installed in the first straight section; the overtravel unit (200) is slidably installed in the second straight section; and the micro switch (20) is fixed in the second section housing (12).

10. A limit switch for valve position detection according to claim 9, characterized in that: It also includes a potting glue (30) and a cable (40), one end of the cable (40) is fixedly connected to the other end of the micro switch (20), and the potting glue (30) is filled in the gap between the cable (40) and the second section shell (12).

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