Actuator for flushing valve

Abstract

The utility model provides an actuator for a flushing valve, the actuator is installed at the opening of the side wall of a valve body, a control motor used for controlling a reduction gear to rotate is installed in a shell, and when the control motor is started, the reduction gear rotates to drive a valve rod to move forwards in the axial direction, a valve element is jacked open, and a flow channel is opened. The N pole of the magnet crosses the Hall switch in the direction close to the valve body, and the Hall switch is triggered to output an induction signal so as to control an external water source piece to supply water into the flow channel. The Hall switch is additionally arranged in the actuator shell, so that the Hall switch can sense movement of the magnet on the mounting frame at the tail end of the valve rod when the valve rod opens or closes the valve port, water supply is started synchronously when the flow channel is opened, and water supply is controlled to be stopped when the flow channel is closed; the operation of opening the flow channel and supplying water (or closing the flow channel and cutting off water), which can be completed in two steps by a traditional flushing valve, can be completed only through one-time movement of the valve rod, and the structure of the flushing valve is simplified.

Description

Technical Field

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

[0002] A flush valve is a device used to control water flow, which is used to regulate, distribute, limit or shut off water flow within the flow channel of the valve body.

[0003] The actuator of the flush valve is used to control the opening and closing of the flow channel. In order to realize the water supply function into the flow channel, an external water source component (such as an angle valve) needs to be installed at the water inlet end of the flow channel. Whether water flows in the flow channel or stops the water flow supply needs to be controlled by switching the angle valve. That is, the opening and closing of the flow channel and the supply and stop of water flow require two steps to be operated on two independent components separately to be realized, resulting in a complex structure of the flush valve and cumbersome steps in actual operation. Utility Model Content

[0004] The utility model provides an actuator for a flush valve, which can effectively solve the above problems.

[0005] The utility model is achieved in this way:

[0006] An actuator for a flush valve is mounted on an opening in a side wall of a valve body. The valve body has a flow channel inside, and a valve core for blocking the flow channel is mounted at a valve port of the valve body.

[0007] The actuator includes a housing, a reduction gear, and a valve stem. The reduction gear is rotatably mounted inside the housing. The valve stem is slidably engaged with the valve body opening, with the end of the valve stem positioned relative to the valve core. The valve stem is actuated by the reduction gear to slide axially, with the axial movement of the valve stem perpendicular to the axis of the reduction gear. A mounting bracket provided at the tail of the valve stem is embedded with a magnet. A Hall effect switch is mounted on the inner wall of the housing near the mounting bracket, which cooperates with the magnetic induction of the magnet to control the opening and closing of the water supply in the flow channel.

[0008] A control motor for controlling the rotation of the reduction gear is installed in the outer shell. When the control motor is started and the reduction gear rotates to drive the valve stem to move axially forward, push open the valve core and open the flow channel, the N pole of the magnet faces the direction close to the valve body and passes over the Hall switch. The Hall switch is triggered to output an induction signal to control the external water source component to supply water into the flow channel; when the reduction gear continues to rotate to drive the valve stem to move axially backward, the valve core re-blocks the valve port and closes the flow channel, the N pole of the magnet moves away from the valve body and away from the Hall switch. At this time, the Hall switch is not triggered and the water supply in the flow channel stops.

[0009] As a further improvement, a driving wheel is fixedly installed on the end face of the reduction gear and is in contact with the tail end of the mounting frame. The driving wheel includes a stop ring area and an action ring area which are connected along the rotation direction. The stop ring area is fixed coaxially with the reduction gear. The radius of the action ring area is larger than that of the stop ring area and the centers of the two circles are staggered. The connecting end of the stop ring area and the action ring area is defined as point B, the opposite end is point A, and the end of the action ring area away from point A is point C; during the contact from point A to point B of the mounting frame and the stop ring area, the end of the valve stem is separated from the valve core, the valve core blocks the valve port, and the flow channel is closed; during the contact from point B to point C of the mounting frame and the action ring area, the valve stem is actuated by the action ring area with an increased radius, moves forward axially, pushes open the valve core, and the flow channel is opened.

[0010] As a further improvement, the actuator also includes a first gear rotatably arranged inside the housing, a second gear meshing with the first gear, a third gear coaxially fixed on the end face of the second gear, a fourth gear meshing with the third gear, and a fifth gear coaxially fixed on the end face of the fourth gear and meshing with the reduction gear; the module of each gear is 0.5, the number of teeth of the first gear is 12, the number of teeth of the second gear is 56, the number of teeth of the third gear is 12, the number of teeth of the fourth gear is 56, the number of teeth of the fifth gear is 12, and the number of teeth of the reduction gear is 60. The transmission ratio of the above four-stage transmission is 109.05:23.35:5:1.

[0011] As a further improvement, a push rod is slidably connected to the rear side wall inside the shell for pushing the magnet on the mounting frame to slide back and forth; an assembly plate is fixedly arranged on the rear side wall inside the shell, and a sliding hole is provided on the assembly plate for the push rod to be slidably connected; a button is screwed to the tail end of the push rod, and an extension hole is provided on the rear side wall of the shell for the button to slide with, and the end face of the button has a limiting ring that abuts against the edge of the extension hole to limit the button from being separated from the extension hole; a return spring is set on the peripheral side of the push rod between the button and the assembly plate.

[0012] As a further improvement, the outer shell is concave relative to the opening position of the valve body to form an installation thread groove, and a connecting piece is threaded in the installation thread groove. The connecting piece has an integrally formed threaded portion, a convex portion and an embedded portion. A through hole is provided from the threaded portion to the convex portion and the embedded portion for the valve stem to slide with. A screw cover is sleeved on the outer side of the convex portion, and the rear end of the screw cover extends inward to form a rest ring which is sleeved into the embedded groove at the rear end of the convex portion. The inner wall surface of the screw cover has an internal thread, and a threaded ring column threaded on the inside of the screw cover is provided on the outside of the valve body interface, and the valve stem is inserted into the opening of the valve body by the threaded ring column.

[0013] As a further improvement, a reset spring is sleeved around the valve stem to provide the valve stem with a tendency to move backward; the threaded portion is threadedly engaged in the mounting threaded groove, an internal threaded hole is provided on the inner wall of the embedded portion, a locking sleeve is threaded in the internal threaded hole, and a accommodating groove for accommodating the reset spring is provided inside the locking sleeve. A contact ring is formed on the circumference of the valve stem near the mounting frame, and one force-bearing end of the reset spring contacts the bottom of the accommodating groove, and the other end contacts the contact ring.

[0014] As a further improvement, the front end of the embedded portion is provided with an insert ring which is tapered from front to back, and the outer side of the insert ring is sleeved with a sealing ring which is tightly fitted with the inner wall of the opening of the valve body.

[0015] As a further improvement, a PCB board is embedded in the top wall of the shell, the Hall switch is installed on the PCB board, the top wall of the shell has a detection area, and a touch sensing spring for controlling the start of the control motor is installed between the detection area of the shell and the PCB board.

[0016] The beneficial effects of the utility model are:

[0017] This application installs a Hall switch in the actuator housing so that it can sense the movement of the magnet on the mounting bracket at the tail end of the valve stem when the valve stem opens or closes the valve port. When the flow channel is opened, the water supply is synchronously turned on, and when the flow channel is closed, the water supply is controlled to be stopped. Only one movement of the valve stem is required to complete the operations of flow channel opening and water supply (or flow channel closing and water stop), which require two steps to complete in a traditional flush valve, thereby simplifying the structure of the flush valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0019] Figure 2 This is a cross-sectional schematic diagram of the internal structure of the actuator of the present invention;

[0020] Figure 3 This is a structural diagram of the utility model that reflects the matching relationship between each gear and the reduction gear;

[0021] Figure 4 This is a schematic diagram of the state in which the flow channel is opened when the valve stem of the utility model pushes the valve core;

[0022] Figure 5 This utility model Figure 4 The enlarged schematic diagram of point E in the middle;

[0023] Figure 6 This is a schematic diagram of the state in which the flow channel is closed when the valve stem and the valve core are separated;

[0024] Figure 7 This is a schematic diagram of the state of the valve stem of the utility model when it is in the initial state after axial backward movement;

[0025] Figure 8 It is a schematic diagram of the state of the utility model when the axial forward movement is in the triggering state.

[0026] The accompanying drawings are marked as follows:

[0027] 10. Valve body; 11. Flow channel; 12. Stop spring; 101. Valve port; 102. Opening; 14. Threaded ring; 20. Actuator; 21. Housing; 211. First gear; 212. Second gear; 213. Third gear; 214. Fourth gear; 215. Fifth gear; 22. Reduction gear; 23. Valve stem; 231. Mounting bracket; 232. Magnet; 233. Contact ring; 24. Hall switch; 25. Control motor; 210. Mounting thread groove; 26. Return spring; 27. Screw cap; 271. Shelf Ring; 28. Assembly plate; 281. Sliding hole; 29. Extending hole; 30. Driving wheel; 31. Stop ring area; 32. Action ring area; 40. Valve core; 41. Gland portion; 42. Rod portion; 43. Sealing gasket; 50. Push rod; 51. Button; 511. Limiting ring; 52. Return spring; 60. Connecting piece; 601. Through hole; 61. Threaded portion; 62. Flange portion; 63. Embedded portion; 631. Insert ring; 64. Locking sleeve; 641. Accommodating groove; 70. Sealing ring; 80. Touch-sensitive spring; 90. PCB board. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] like Figures 1 to 8 As shown, the flush valve includes a valve body 10 and an actuator 20 attached to an opening 102 on the side wall of the valve body 10. The valve body 10 has a flow channel 11, and a valve core 40 for blocking the flow channel 11 is installed at the valve port 101 of the valve body 10. The actuator 20 includes a housing 21, a reduction gear 22 and a valve stem 23. The reduction gear 22 is rotatably installed inside the housing 21. The valve stem 23 is slidably fitted at the opening 102 of the valve body 10, and the end of the valve stem 23 is relative to the valve core 40. The valve stem 23 is actuated by the reduction gear 22 to slide axially, and the axial movement direction of the valve stem 23 is perpendicular to the axial direction of the reduction gear 22; a mounting bracket 231 provided at the tail of the valve stem 23 is embedded with a magnet 232, and a Hall switch 24 is installed on the inner wall surface of the housing 21 near the mounting bracket 231 to cooperate with the magnet 232 to control the opening and closing of water supply in the flow channel 11.

[0030] like Figures 1 to 8As shown, a control motor 25 for controlling the rotation of the reduction gear 22 is installed in the housing 21. When the control motor 25 is started and the reduction gear 22 rotates to drive the valve stem 23 to move axially forward, push the valve core 40 and open the flow channel 11, the north pole of the magnet 232 passes over the Hall switch 24 in a direction close to the valve body 10. The Hall switch 24 is triggered to output a sensing signal to control the external water source component (not shown) to supply water into the flow channel 11. When the reduction gear 22 continues to rotate to drive the valve stem 23 to move axially backward, the valve core 40 re-blocks the valve port 101 and closes the flow channel 11, the north pole of the magnet 232 moves in a direction away from the valve body 10 and away from the Hall switch 24. At this time, the Hall switch 24 is not triggered, and the water supply in the flow channel 11 is stopped. Of course, in other embodiments, it can also be set that when the south pole of the magnet 232 passes over the Hall switch 24, the Hall switch 24 is triggered to output a sensing signal to control the external water source component to supply water into the flow channel 11. It should be noted here that the external water source component used in this application can be an angle valve or other water supply equipment.

[0031] The structures of the various components of the present invention are described below.

[0032] like Figures 2 to 6 As shown, the end face of the reduction gear 22 is fixed with a driving wheel 30 that contacts and cooperates with the tail end of the mounting bracket 231. The driving wheel 30 includes a stop ring area 31 and an action ring area 32 that are connected along the rotation direction. The stop ring area 31 is coaxially fixed with the reduction gear 22. The radius of the action ring area 32 is larger than the stop ring area 31 and the centers of the two circles are staggered. The connecting end of the stop ring area 31 and the action ring area 32 is defined as point B, the opposite end is point A, and the end of the action ring area 32 away from point A is point C; in the process of contact between the mounting bracket 231 and the stop ring area 31 from point A to point B, the end of the valve stem 23 is separated from the valve core 40, the valve core 40 blocks the valve port 101, and the flow channel 11 is closed; in the process of contact between the mounting bracket 231 and the action ring area 32 from point B to point C, the valve stem 23 is actuated by the action ring area 32 with an increased radius, moves axially forward, pushes open the valve core 40, and the flow channel 11 is opened.

[0033] It should be noted here that the direction of rotation of the driving wheel 30 is clockwise. When the reduction gear 22 drives the driving wheel 30 to rotate, the mounting bracket 231 first contacts the stop ring area 31 of the driving wheel 30. During the contact process from point A to point B between the mounting bracket 231 and the stop ring area 31, the valve stem 23 is not subjected to force and does not undergo axial displacement. The valve body 10 is in the initial state where the flow channel 11 is closed and no water flow is supplied. This process takes 0.5s. As the driving wheel 30 continues to rotate clockwise, the mounting bracket 231 transitions to contact with the action ring area 32 of the driving wheel 30. 2 from point B to point C, the action ring area 32 actuates the valve stem 23 to move axially forward, pushes open the valve core 40 and opens the flow channel 11. At this time, the Hall switch 24 is triggered to output a sensing signal, controlling the external water source to supply water to the flow channel 11. The valve body 10 is in a triggered state in which the flow channel 11 is open and water is supplied. This process takes 0.5s. If the driving wheel 30 continues to rotate clockwise at this time, the mounting bracket 231 quickly falls back from point C of the action ring area 32 to the initial state of contact with point A of the stop ring area 31, that is, at this time the flow channel 11 is quickly closed and there is no water supply in the valve body 10.

[0034] like Figure 4 and Figure 6 As shown, the valve core 40 includes an integrally formed pressure cover portion 41 for pressing and sealing the valve port 101 and a rod portion 42 extending downward from the middle of the lower end surface of the pressure cover portion 41. The water inlet end of the valve body 10 is provided with a flow-stop spring 12 that presses the pressure cover portion 41 downward to seal the valve core 40 and press the valve port 101. A sealing gasket 43 is interference-locked at the valve port 101; when the flow channel 11 is closed, the flow-stop spring 12 presses the pressure cover portion 41 downward and presses it at the valve port 101. At this time, the axis of the rod portion 42 is perpendicular to the axis of the valve stem 23. When the flow channel 11 is opened, the valve stem 23 slides forward and pushes the rod portion 50 42, causing its axis to deviate from the original axial position, driving one side of the pressure cover portion 41 to tilt up to open the valve port 101.

[0035] like Figure 3 As shown, the actuator 20 further includes a first gear 211 rotatably disposed within the housing 21, a second gear 212 meshing with the first gear 211, a third gear 213 coaxially fixed to the end face of the second gear 212, a fourth gear 214 meshing with the third gear 213, and a fifth gear 215 coaxially fixed to the end face of the fourth gear 214 and meshing with the reduction gear 22. Each gear has a module of 0.5. The first gear 211 has 12 teeth, the second gear 212 has 56 teeth, the third gear 213 has 12 teeth, the fourth gear 214 has 56 teeth, the fifth gear 215 has 12 teeth, and the reduction gear 22 has 60 teeth. The transmission ratio of the above four-stage transmission is 109.05:23.35:5:1.

[0036] It is worth noting that after multiple tests, the above-mentioned multi-stage gear transmission method is used to drive the axial displacement of the valve stem 23. When testing the flushing diaphragm under 0.55 MPa, the valve stem 23 can push open the valve core 40 within 1 second, that is, it has the advantage of quickly opening the flow channel 11 and realizing water supply to the flow channel 11.

[0037] like Figure 2 and Figure 7 、 Figure 8 As shown, the output shaft of the control motor 25 is fixedly connected to the first gear 211 to drive the first gear 211 to rotate; a push rod 50 is slidably connected to the rear side wall inside the housing 21 to push the magnet 232 on the mounting bracket 231 to slide back and forth; an assembly plate 28 is fixedly provided on the rear side wall inside the housing 21, and a sliding hole 281 for the push rod 50 to slide is provided on the assembly plate 28; a button 51 is screwed to the tail end of the push rod 50, and an extension hole 29 for the button 51 to slide with is provided on the rear side wall of the housing 21, and the end surface of the button 51 has A limiting ring 511 abuts against the edge of the extension hole 29 to limit the button 51 from being separated from the extension hole 29; a return spring 52 is provided between the button 51 and the assembly plate 28 and is connected to the circumference of the push rod 50; with this design, the user can choose to use the motor to control the rotation of the drive wheel 30 to actuate the axial sliding of the valve stem 23 according to the specific use environment, or to use the push rod 50 to synchronously actuate the magnet 232, the mounting bracket 231 and the valve stem 23 to slide axially. Compared with a single use method, the water control valve of the present application has a wider applicability.

[0038] like Figures 4 to 6 As shown, the housing 21 is concave relative to the opening 102 of the valve body 10 to form a mounting thread groove 210, and a connecting piece 60 is screwed into the mounting thread groove 210. The connecting piece 60 has an integrally formed screw portion 61, a convex portion 62 and an embedded portion 63. A through hole 601 for sliding cooperation of the valve stem 23 is opened from the screw portion 61 to the convex portion 62 and the embedded portion 63. A return spring 26 is sleeved on the circumference of the valve stem 23 to provide the valve stem 23 with a tendency to move backward; the screw portion 61 is screwed to the convex portion 62 and the embedded portion 63. The portion 61 is threadedly engaged in the mounting thread groove 210, and an internal threaded hole is provided on the inner wall of the embedded portion 63, in which a locking sleeve 64 is threaded, and an accommodating groove 641 for accommodating the reset spring 26 is provided inside the locking sleeve 64, and a contact ring 233 is formed on the circumference of the valve stem 23 near the mounting frame 231. One force-bearing end of the reset spring 26 contacts the bottom of the accommodating groove 641, and the other end contacts the contact ring 233, thereby providing the valve stem 23 with a tendency to move backward.

[0039] like Figures 4 to 6As shown, a screw cap 27 is sleeved on the outer side of the convex portion 62, and the rear end of the screw cap 27 extends inward to form a rest ring 271 that is sleeved into the embedded groove at the rear end of the convex portion 62. The inner wall surface of the screw cap 27 has an internal thread, and a threaded ring column 14 is provided on the outer side of the interface of the valve body 10, which is screwed to the inside of the screw cap 27. The valve stem 23 is inserted into the opening 102 of the valve body 10 through the threaded ring column 14. The screw cap 27 is tightened on the outer side of the threaded ring column 14, and the actuator 20 can be quickly assembled on the valve body 10; at the front end of the embedded portion 63, there is a plug ring 631 that is tapered from front to back, and a sealing ring 70 is sleeved on the outer side of the plug ring 631 and is tightly fitted with the inner wall of the opening 102 of the valve body 10; through the provision of the sealing ring 70, water can be prevented from flowing into the actuator 20 through the gap between the valve stem 23 and the opening 102, thereby improving the safety of the water control valve during use.

[0040] like Figure 7 and Figure 8 As shown, a PCB board 90 is embedded in the top wall of the housing 21, and the Hall switch 24 is installed on the PCB board 90. The top wall of the housing 21 has a detection area. A touch sensing spring 80 for controlling the start of the control motor 25 is installed between the detection area of the housing 21 and the PCB board 90. When the user applies force to the corresponding position of the top wall of the housing 21, due to the thin thickness of the detection area of the housing 21, the pressure applied by the hand indirectly acts on the touch sensing spring 80, and the PCB board 90 detects the electrical contact between the human hand and the touch sensing spring. The change in capacitance is converted into a corresponding electrical signal, which activates the control motor 25. The valve stem 23 moves axially forward, pushing open the valve core 40, and the north pole of the magnet 232 approaches the Hall switch 24, completing a valve opening action (i.e., the flow channel 11 is opened and water flow channel 11 is supplied). The valve stem 23 then moves axially backward, separating from the valve core 40, and the north pole of the magnet 232 moves away from the Hall switch 23, completing a valve closing action. At this time, the control motor 25 is turned off. When the user removes the external force, the capacitance between the touch-sensing spring 80 and the hand returns to its initial state. It should be noted that a single touch can only control one flush valve opening and closing action.

[0041] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. A person skilled in the art may make various modifications or changes without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention and be defined by the claims.

Claims

1. An actuator for a flush valve, the actuator (20) being mounted on an opening (102) on a side wall of a valve body (10), the valve body (10) having a flow channel (11) therein, and a valve core (40) for blocking the flow channel (11) being mounted on a valve port (101) of the valve body (10); characterized in that: The actuator (20) includes a housing (21), a reduction gear (22) and a valve stem (23). The reduction gear (22) is rotatably mounted inside the housing (21). The valve stem (23) is slidably engaged with the opening (102) of the valve body (10) and the end of the valve stem (23) is positioned relative to the valve core (40). The valve stem (23) is actuated by the reduction gear (22) to slide axially. The axial movement direction of the valve stem (23) is perpendicular to the axial direction of the reduction gear (22). A magnet (232) is embedded in a mounting bracket (231) provided at the tail of the valve stem (23). A Hall switch (24) is mounted on the inner wall surface of the housing (21) near the mounting bracket (231) to cooperate with the magnet (232) in magnetic induction to control the opening and closing of water supply in the flow channel (11). A control motor (25) for controlling the rotation of the reduction gear (22) is installed in the housing (21). When the control motor (25) is started and the reduction gear (22) is rotated to drive the valve stem (23) to move axially forward, push open the valve core (40) and open the flow channel (11), the N pole of the magnet (232) moves toward the direction close to the valve body (10) and passes over the Hall switch (24). The Hall switch (24) is triggered to output a sensing signal to control the external water source component to supply water to the flow channel (11); when the reduction gear (22) continues to rotate to drive the valve stem (23) to move axially backward, the valve core (40) re-blocks the valve port (101) and closes the flow channel (11), the N pole of the magnet (232) moves toward the direction away from the valve body (10) and away from the Hall switch (24). At this time, the Hall switch (24) is not triggered and the water supply in the flow channel (11) stops.

2. The flush valve actuator according to claim 1, wherein: The end face of the reduction gear (22) is fixed with a driving wheel (30) that contacts and matches the tail end of the mounting frame (231). The driving wheel (30) includes a stop ring area (31) and an action ring area (32) that are connected along the rotation direction. The stop ring area (31) and the reduction gear (22) are fixed coaxially. The radius of the action ring area (32) is larger than that of the stop ring area (31) and the centers of the two circles are staggered. The stop ring area (31) and the action ring area (32) are connected at one end as point B and the opposite end as point A. The end of (32) away from point A is point C; during the contact process between the mounting frame (231) and the stop ring area (31) from point A to point B, the end of the valve stem (23) is separated from the valve core (40), the valve core (40) blocks the valve port (101), and the flow channel (11) is closed; during the contact process between the mounting frame (231) and the action ring area (32) from point B to point C, the valve stem (23) is actuated by the action ring area (32) with an increased radius, moves axially forward, pushes open the valve core (40), and the flow channel (11) is opened.

3. The flush valve actuator according to claim 1, wherein: The actuator (20) further includes a first gear (211) rotatably arranged inside the housing (21), a second gear (212) meshing with the first gear (211), a third gear (213) coaxially fixed on the end face of the second gear (212), a fourth gear (214) meshing with the third gear (213), and a fifth gear (215) coaxially fixed on the end face of the fourth gear (214) and meshing with the reduction gear (22); the module of each gear is 0.5, the number of teeth of the first gear (211) is 12, the number of teeth of the second gear (212) is 56, the number of teeth of the third gear (213) is 12, the number of teeth of the fourth gear (214) is 56, the number of teeth of the fifth gear (215) is 12, and the number of teeth of the reduction gear (22) is 60. The transmission ratio of the above four-stage transmission is 109.05: 23.35: 5:

1.

4. The flush valve actuator according to claim 1, wherein: A push rod (50) is slidably connected to the rear side wall inside the housing (21) for pushing the magnet (232) on the mounting frame (231) to slide back and forth; an assembly plate (28) is fixedly arranged on the rear side wall inside the housing (21), and a sliding hole (281) for sliding connection of the push rod (50) is opened on the assembly plate (28); a button (51) is screwed to the tail end of the push rod (50), and an extension hole (29) for sliding engagement with the button (51) is opened on the rear side wall of the housing (21), and the end surface of the button (51) has a limiting ring (511) that abuts against the edge of the extension hole (29) to limit the button (51) from being separated from the extension hole (29); a return spring (52) is provided between the button (51) and the assembly plate (28) and is sleeved on the circumference of the push rod (50).

5. The flush valve actuator according to claim 1, wherein: The housing (21) is concave relative to the opening (102) of the valve body (10) to form a mounting thread groove (210), and a connecting piece (60) is screwed into the mounting thread groove (210). The connecting piece (60) has an integrally formed screw connection portion (61), a convex portion (62) and an embedded portion (63). A through hole (60) for sliding engagement of the valve stem (23) is provided from the screw connection portion (61) to the convex portion (62) and the embedded portion (63). 1), a screw cap (27) is sleeved on the outer side of the convex portion (62), and the rear end of the screw cap (27) extends inward to form a shelf ring (271) that is sleeved into the recess of the rear end of the convex portion (62). The inner wall surface of the screw cap (27) has an internal thread, and a threaded ring column (14) is provided on the outer side of the interface of the valve body (10) and is screwed to the inside of the screw cap (27). The valve stem (23) is inserted into the opening (102) of the valve body (10) by the threaded ring column (14).

6. The flush valve actuator according to claim 5, wherein: A return spring (26) is sleeved on the circumferential side of the valve stem (23) to provide the valve stem (23) with a tendency to move backward; the threaded portion (61) is threadedly engaged in the mounting thread groove (210); an internal threaded hole is provided on the inner wall of the embedded portion (63); a locking sleeve (64) is threaded in the internal threaded hole; a receiving groove (641) for receiving the return spring (26) is provided inside the locking sleeve (64); a contact ring (233) is formed on the circumferential side of the valve stem (23) near the mounting frame (231); one force-bearing end of the return spring (26) contacts the bottom of the receiving groove (641), and the other end contacts the contact ring (233).

7. The flush valve actuator according to claim 5, wherein: A plug ring (631) is provided at the front end of the embedded portion (63), which is tapered from front to back. A sealing ring (70) is sleeved on the outside of the plug ring (631) and is tightly fitted with the inner wall of the opening (102) of the valve body (10).

8. The flush valve actuator according to claim 1, wherein: A PCB board (90) is embedded on the top wall of the housing (21), a Hall switch (24) is mounted on the PCB board (90), the top wall of the housing (21) has a detection area, and a touch sensing spring (80) for controlling the start of the control motor (25) is installed between the detection area of the housing (21) and the PCB board (90).

Images