Valve actuating mechanism

Abstract

The utility model provides a valve actuating mechanism which comprises a shell, a valve rod, a transmission mechanism, a driving device and at least three sets of photoelectric switches. The valve rod is rotationally installed on the shell, one end of the valve rod penetrates out of the shell to be connected with an external valve element, and the valve rod is provided with an induction rod in the radial direction. The transmission mechanism is respectively connected with the valve rod and the driving device; the driving device is mounted on the shell; the at least three sets of optoelectronic switches are arranged around the circumference of the valve rod and used for sensing the position of the sensing rod. The sensing rod is arranged on the valve rod in the radial direction, the transmission mechanism is driven by the driving device to drive the valve rod to rotate, the at least three sets of photoelectric switches are arranged around the circumference of the valve rod and used for sensing the position of the sensing rod, the specific position of the valve rod in the middle can be accurately sensed, and the control precision is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, in particular to a valve actuator. Background Art

[0002] Valves are commonly used products in people's daily lives. They are connected to water or gas supply pipelines to control the switch of the pipeline or adjust the flow in the pipeline. Currently, the more commonly used valves are often to manually turn the handle to rotate the valve core inside the valve, thereby changing the opening of the valve. As people's requirements for intelligence and automation become higher and higher, electric valves have appeared in the valve field and gradually become popular. They use controllers, operation panels or sensors to cooperate with motors to automatically drive the valve stem movement of the valve, and then drive the valve core movement, which is more convenient to use. However, existing electric valves are often directly controlled by the controller to control the motor to adjust the opening of the valve. The specific position of the valve stem movement cannot be determined, and there is a problem of low control accuracy.

[0003] In the prior art, the position of the valve stem is generally sensed by a contact sensor, but the valve stem can only move between two contact sensors. The contact sensor can only sense the valve stem in two positions at most and cannot accurately sense the specific position of the valve stem in the middle position, resulting in low control accuracy. Utility Model Content

[0004] In view of this, the utility model proposes a valve actuator to solve the technical problem that the contact sensor proposed in the above background technology can only sense the valve stem at two positions at most, cannot accurately sense the specific position of the valve stem when it is in the middle position, and has low control accuracy.

[0005] The technical solution of the utility model is achieved in this way:

[0006] The utility model provides a valve actuator, comprising a housing, a valve stem, a transmission mechanism, a driving device and at least three groups of photoelectric switches, wherein:

[0007] The valve stem is rotatably mounted on the housing, and one end of the valve stem passes through the housing and is connected to an external valve core, and a sensing rod is provided along the radial direction of the valve stem;

[0008] The transmission mechanism is connected to the valve stem and the driving device respectively;

[0009] The driving device is mounted on the housing;

[0010] At least three groups of photoelectric switches are arranged around the axis of the valve stem and are used to sense the position of the sensing rod.

[0011] On the basis of the above technical solution, preferably, two sensing parts are arranged on the sensing rod, two photoelectric switches are arranged in each group, and the two photoelectric switches are arranged at intervals along the radial direction of the valve stem.

[0012] On the basis of the above technical solution, preferably, the transmission mechanism includes a worm wheel and a worm, the worm wheel is fixedly connected to the valve stem, and the worm is connected to the driving device and meshes with the worm wheel.

[0013] On the basis of the above technical solution, preferably, the worm is a single-start worm.

[0014] On the basis of the above technical solution, preferably, the helix angle of the worm wheel is smaller than the friction angle of contact between the worm wheel and the worm.

[0015] On the basis of the above technical solution, preferably, the transmission ratio between the worm and the worm wheel is 1:20.

[0016] On the basis of the above technical solution, preferably, it further comprises a mounting plate, wherein the mounting plate is connected to the housing, and at least three groups of the photoelectric switches are mounted on the mounting plate.

[0017] On the basis of the above technical solution, preferably, at least three groups of the photoelectric switches are evenly arranged on a circle with the axis of the valve stem as the center line.

[0018] On the basis of the above technical solution, preferably, the driving device includes a driving motor and a reducer, and the reducer is connected to the driving motor and the worm respectively.

[0019] On the basis of the above technical solution, preferably, a switching socket is further provided on the housing, one end of the switching socket is electrically connected to the photoelectric switch, and the other end is used for plugging an external signal line.

[0020] The valve actuator of the utility model has the following beneficial effects compared with the prior art:

[0021] (1) The valve stem is provided with a sensing rod in the radial direction, and the transmission mechanism drives the valve stem to rotate under the drive of the driving device. At least three groups of photoelectric switches are arranged around the circumference of the valve stem to sense the position of the sensing rod. The specific position of the valve stem in the middle position can be accurately sensed, thereby improving the control accuracy;

[0022] (2) By providing two sensing parts on the sensing rod, each group of the photoelectric switches is provided with two photoelectric switches, one for use and one for backup. When one of the photoelectric switches in a group fails, the other photoelectric switch can be used for sensing, thereby improving the reliability of the device;

[0023] (3) The worm adopts a single-head worm, and the worm rotates one circle, and the worm wheel rotates one tooth, so that the transmission between the worm wheel and the worm is more stable. The single-head worm wheel has the advantages of simple structure, low manufacturing cost, small size, light weight, space saving, stable transmission, low noise, and convenient for flexible arrangement of worm wheels. The size of the valve actuator can be made smaller and the cost is lower.

[0024] (4) The helix angle of the worm wheel is smaller than the friction angle between the worm wheel and the worm, so that the transmission mechanism has a self-locking ability, that is, the worm wheel can only be driven by the worm, and the worm cannot be rotated when the worm wheel reverses to drive the worm, thereby improving the reliability of the device and the stability of the valve opening control;

[0025] (5) The transmission ratio between the worm and the worm wheel is 1:20, which can further improve the self-locking ability of the transmission mechanism and further improve the reliability and stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a cross-sectional view of the valve actuator of the utility model;

[0028] Figure 2 It is a three-dimensional diagram of the valve actuator of the utility model;

[0029] Figure 3 A three-dimensional diagram of the valve actuator of the utility model without the housing;

[0030] Figure 4 It is a structural schematic diagram of the photoelectric switch, mounting plate and valve stem of the utility model;

[0031] Figure 5 It is a three-dimensional diagram of the shell of the utility model.

[0032] Description of reference numerals: 1-housing, 2-valve stem, 3-transmission mechanism, 4-driving device, 5-photoelectric switch, 6-mounting plate, 7-first bearing, 8-second bearing;

[0033] 11-ear seat, 12-adapter socket;

[0034] 21-sensing rod, 211-sensing part;

[0035] 31-worm wheel, 32-worm, 33-transmission shaft;

[0036] 41-driving motor, 42-reducing gear;

[0037] 51-sensing slot;

[0038] 61-Mounting holes. DETAILED DESCRIPTION

[0039] The following will be combined with the implementation of the utility model to clearly and completely describe the technical solutions in the implementation of the utility model. Obviously, the described implementation is only a part of the implementation of the utility model, not all of the implementations. Based on the implementation of the utility model, all other implementations obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] Reference Figure 1-Figure 5 As shown, the embodiment of the utility model proposes a valve actuator, including a housing 1, a valve stem 2, a transmission mechanism 3, a drive device 4 and at least three groups of photoelectric switches 5, wherein:

[0041] The valve stem 2 is rotatably mounted on the housing 1, and one end of the valve stem 2 passes through the housing 1 and is connected to an external valve core. The valve stem 2 is provided with a sensing rod 21 along the radial direction; one end of the valve stem 2 is connected to the housing 1 through a first bearing 7, so that the valve stem 2 can rotate;

[0042] The transmission mechanism 3 is connected to the valve stem 2 and the driving device 4 respectively, and is used to drive the valve stem 2 to rotate under the drive of the driving device 4;

[0043] The driving device 4 is mounted on the housing 1;

[0044] At least three groups of photoelectric switches 5 are arranged around the axis of the valve stem 2 to sense the position of the sensing rod 21. At least three groups of photoelectric switches 5 are arranged around the circumference of the valve stem 2 to sense the two end positions and the middle position between the two end positions, and can provide more feedback on the specific position of the valve opening, with higher control accuracy. The number of groups of photoelectric switches 5 can be set according to the sensitivity requirements of the sensing.

[0045] It should be noted that the commonly used photoelectric switch 5 uses the principle of reflection of near-infrared light beams by objects, and the synchronous circuit senses the intensity of the reflected light to detect the existence of the object to achieve its function. The photoelectric sensor first sends an infrared light beam to reach or pass through the object or mirror to reflect the infrared light beam, and the photoelectric sensor receives the reflected light beam and determines the existence of the object according to the intensity of the light beam. The above are all the sensing principles of the photoelectric switch used in the prior art, and the utility model does not involve improvements in the circuit or program of the photoelectric switch 5.

[0046] The valve actuator provided in this embodiment is provided with a sensing rod 21 in the radial direction through the valve stem 2. The transmission mechanism 3 drives the valve stem 2 to rotate under the drive of the driving device 4. At least three groups of photoelectric switches 5 are arranged around the circumference of the valve stem 2 to sense the position of the sensing rod 21. The specific position of the valve stem 2 in the middle position can be accurately sensed, thereby improving the control accuracy.

[0047] In some embodiments, the sensing rod 21 is provided with two sensing parts 211, and each group of the photoelectric switches 5 is provided with two. The two photoelectric switches 5 are arranged at intervals along the radial direction of the valve stem 2, and the sensing switch matches the sensing part 211. By providing two sensing parts 211 on the sensing rod 21, and each group of the photoelectric switches 5 is provided with two, the two photoelectric switches 5 are used and one is reserved. When one of the photoelectric switches 5 in a group of photoelectric switches 5 fails, the other photoelectric switch 5 can be sensed, thereby improving the reliability of the device. The sensing part 211 is a protrusion of the sensing rod 21 facing the photoelectric switch 5. The photoelectric switch 5 is provided with a sensing slot 51. When the sensing part 211 passes through the sensing slot 51, the signal is blocked, so that the sensing rod 21 is sensed to rotate to this position, so as to know the rotation angle of the valve stem 2 and the opening of the valve.

[0048] In some embodiments, the transmission mechanism 3 includes a worm wheel 31 and a worm 32, wherein the worm wheel 31 is fixedly connected to the valve stem 2, and the worm 32 is connected to the driving device 4 and meshed with the worm wheel 31. The transmission mechanism 3 is also provided with a transmission shaft 33, one end of which is connected to the housing 1 through a second bearing 8, and the other end is fixedly connected to the valve stem 2, the worm wheel 31 is mounted on the transmission shaft 33, and the worm wheel 31 and the transmission shaft 33 are fixed by a key connection, the worm 32 is connected to the driving device 4 and meshed with the worm wheel 31, and the driving device 4 drives the worm 32 to rotate, thereby driving the worm wheel 31 to rotate, so as to drive the valve stem 2 to rotate together, thereby realizing the adjustment of the valve opening.

[0049] In some embodiments, the worm 32 is a single-head worm. When the worm 32 is a single-head worm, the worm 32 rotates one circle, and the worm wheel 31 rotates one tooth, so that the transmission between the worm wheel 31 and the worm 32 is more stable. The single-head worm wheel 31 has the advantages of simple structure, low manufacturing cost, small size, light weight, space saving, stable transmission, and low noise. It is convenient to flexibly arrange the worm wheel 31, and the size of the valve actuator can be made smaller and the cost is lower. Therefore, the worm wheel 31 is preferably a single-head worm wheel 31.

[0050] In some embodiments, the helix angle of the worm wheel 31 is smaller than the friction angle of the worm wheel 31 and the worm 32. The helix angle of the worm wheel 31 is smaller than the friction angle of the worm wheel 31 and the worm 32, so that the transmission mechanism 3 has a self-locking ability, that is, the worm wheel 31 can only be driven to rotate by the worm 32, and the worm wheel 31 cannot rotate when the worm 32 is reversed to drive the worm 32, thereby improving the reliability of the device and the stability of the valve opening control.

[0051] In some embodiments, the transmission ratio of the worm 32 to the worm wheel 31 is 1:20. By setting the transmission ratio of the worm 32 to the worm wheel 31 to 1:20, the self-locking ability of the transmission mechanism 3 can be further improved, and the reliability and stability of the device can be further improved.

[0052] In some embodiments, the valve actuator further includes a mounting plate 6, the mounting plate 6 is connected to the housing 1, and at least three groups of the photoelectric switches 5 are mounted on the mounting plate 6. The mounting plate 6 is located inside the housing 1, and a mounting hole 61 is provided on the mounting plate 6. The housing 1 is provided with an ear seat 11, and the mounting plate 6 is connected to the housing 1 by a bolt passing through the mounting hole 61 and connected with the threaded hole of the ear seat 11, so as to realize the connection between the mounting plate 6 and the housing 1, and the plane where the mounting plate 6 is located is parallel to the radial direction of the valve stem 2, and the photoelectric switch 5 is arranged on the side of the mounting plate 6 away from the worm gear 31, so as to avoid the light generated by the meshing of the worm gear 31 and the worm 32 from interfering with the photoelectric switch 5, thereby improving the reliability and stability of the device.

[0053] In some embodiments, at least three groups of photoelectric switches 5 are evenly arranged around the axis of the valve stem 2. Figure 4 As shown, three groups of photoelectric switches 5 are evenly arranged around the circumference of the valve stem 2, and the angular interval between two adjacent groups of photoelectric switches 5 is 120 degrees. Through the evenly arranged photoelectric switches 5, the situation where the valve stem 2 rotates to different positions in the circumferential direction can be well detected. According to the sensitivity requirements, more groups of photoelectric switches 5 can be set to detect more positions and improve the control accuracy.

[0054] In some embodiments, the driving device 4 includes a driving motor 41 and a reducer 42, and the reducer 42 is respectively connected to the driving motor 41 and the worm 32. The driving motor 41 drives the reducer 42 to move, and the reducer 42 transmits the driving force to the worm 32 after deceleration, so that the speed of the worm 32 is not too fast, thereby improving the stability of the valve switch.

[0055] In some embodiments, the housing 1 is further provided with a transfer socket 12, one end of which is electrically connected to the photoelectric switch 5, and the other end is used to plug in an external signal line. By electrically connecting one end of the transfer socket 12 to the photoelectric switch 5 and the other end to plug in an external signal line, the wiring of the photoelectric switch 5 is facilitated, and the convenience and efficiency of assembly are improved.

[0056] The working principle of the valve actuator is: the driving device 4 drives the worm 32 to rotate, thereby driving the worm wheel 31 to rotate, so as to drive the valve stem 2 to rotate together, so as to adjust the valve opening; during the rotation of the valve stem 2, the sensing rod 21 rotates together, and when the sensing part 211 passes through the sensing slot 51 of the photoelectric switch 5, the signal is blocked, so that the sensing rod 21 is sensed to rotate to this position, thereby knowing the rotation angle of the valve stem 2, and the valve opening can be monitored to improve the control accuracy of the valve opening.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A valve actuator, characterized in that: It includes a housing, a valve stem, a transmission mechanism, a drive device and at least three sets of photoelectric switches, wherein: The valve stem is rotatably mounted on the housing, and one end of the valve stem passes through the housing and is connected to an external valve core, and a sensing rod is provided along the radial direction of the valve stem; The transmission mechanism is connected to the valve stem and the driving device respectively; The driving device is mounted on the housing; At least three groups of photoelectric switches are arranged around the axis of the valve stem and are used to sense the position of the sensing rod.

2. The valve actuator according to claim 1, characterized in that: The sensing rod is provided with two sensing parts, each group of the photoelectric switches is provided with two, and the two photoelectric switches are spaced apart along the radial direction of the valve stem.

3. The valve actuator according to claim 1, characterized in that: The transmission mechanism comprises a worm wheel and a worm, wherein the worm wheel is fixedly connected to the valve stem, and the worm is connected to the driving device and meshes with the worm wheel.

4. The valve actuator according to claim 3, characterized in that: The worm is a single-start worm.

5. The valve actuator according to claim 4, characterized in that: The helix angle of the worm wheel is smaller than the friction angle of the worm wheel in contact with the worm.

6. The valve actuator according to claim 5, characterized in that: The transmission ratio between the worm and the worm wheel is 1:

20.

7. The valve actuator according to claim 6, characterized in that: It also includes a mounting plate, which is connected to the housing, and at least three groups of photoelectric switches are mounted on the mounting plate.

8. The valve actuator according to claim 7, characterized in that: At least three groups of photoelectric switches are evenly arranged around the circumference of the valve stem with the axis of the valve stem as the center line.

9. The valve actuator according to any one of claims 3 to 8, characterized in that: The driving device comprises a driving motor and a reducer, and the reducer is connected to the driving motor and the worm respectively.

10. The valve actuator according to any one of claims 1 to 8, characterized in that: The housing is also provided with a transfer socket, one end of which is electrically connected to the photoelectric switch, and the other end of which is used for plugging in an external signal line.

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