Electric actuator

Abstract

To provide an electric actuator that connects a rotating shaft to a shaft of a different type of a water supply control device.SOLUTION: An electric actuator 10 includes a rotating shaft 50 that is rotated by a motor via a transmission mechanism, and is attached to a water supply device 104. A rectangular column section 138 is formed at an upper end of a shaft 128 of the water supply device. A connector 300 includes a pair of legs that sandwich opposing side surfaces 140 of the rectangular column section with a clamping section, and a step section formed on each of inner surfaces of the legs above the clamping section, and the pair of legs are connected at an upper end by a connecting section. An upper part 308b of the connecting section fits into a slit at a lower end of the rotating shaft. By attaching the connecting section of the connector 300 to the lower end of the rotating shaft 50, the shaft 128 sandwiched by the clamping section is rotated by the rotating shaft 50. A nut 144 protruding at an upper end part of the shaft in a direction perpendicular to an axial direction of the shaft engages with the step section, preventing the water supply control device from coming off.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an electric actuator, and more particularly to an electric actuator that is attached to a water supply control device having a displacement mechanism that controls water supply by displacing a valve body or a partition body, for example, to operate the displacement mechanism of the water supply control device. [Background technology]

[0002] One example of this type of conventional electric actuator is disclosed in Patent Document 1. Patent Document 1 discloses an automatic opening and closing device that is attached to an existing water faucet or water supply weir and automatically opens and closes the water faucet or water supply weir.

[0003] Another example of this type of conventional electric actuator is disclosed in Patent Document 2. Patent Document 2 discloses a water supply device with an electric actuator already integrated therein.

[0004] In order to solve the problems of Patent Document 1 and Patent Document 2, the applicant of the present invention proposed an electric actuator shown in Patent Document 3. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-70716 [Patent Document 2] Japanese Patent Application Publication No. 8-275684 [Patent Document 3] JP 2017-192367 A Summary of the Invention [Problem to be solved by the invention]

[0006] The electric actuator of Patent Document 3 can be made smaller and less expensive, so it is desirable to utilize this advantage in as wide a range of applications as possible.

[0007] SUMMARY OF THE PRESENT EMBODIMENTS Therefore, a primary object of the present invention is to provide a novel electric actuator.

[0008] Another object of the present invention is to provide an electric actuator that can be attached to different types of water control devices. [Means for solving the problem]

[0009] The first invention is an electric actuator attached to a water supply control device having a displacement mechanism that controls water supply by displacement of a valve body or partition body linked to the rotation of a shaft, and operates the displacement mechanism, the electric actuator comprising: a main body case, a motor provided in the main body case, a transmission mechanism provided in the main body case and transmitting the drive of the motor, a rotating shaft rotated by the motor via the transmission mechanism and having a lower portion extending downwardly of the main body case, and a coupling device for connecting the rotating shaft to the shaft, the upper end of the shaft having at least one pair of opposing side surfaces, the coupling device having a pair of legs that clamp the opposing side surfaces of the upper end of the shaft with a clamping portion, stepped portions each formed on the inner surface of the legs above the clamping portions, and a connecting portion connecting the pair of legs at their respective upper ends, the connecting portion being connected to the lower end of the rotating shaft, so that the rotating shaft imparts rotation to the shaft via the coupling device, and the coupling device is prevented from coming off the shaft by engaging a protrusion integral with the shaft with the stepped portion.

[0010] In the first aspect of the present invention, an electric actuator (10: reference showing the part illustrated in the embodiment) The reference symbol (hereinafter the same applies).) is attached to a water supply control device having a displacement mechanism that controls water supply by the displacement of a valve body or a partition body that is linked to the rotation of the shaft, and operates the displacement mechanism. The electric actuator includes a main body case (20), a motor (38) provided within the main body case, a transmission mechanism (42, 40,) provided within the main body case and transmitting the drive of the motor, a rotating shaft (50) that is rotated by the motor via the transmission mechanism and has a lower portion extending below the main body case, and a connector (300) for connecting the rotating shaft to the shaft. The upper end of the shaft has at least one pair of opposing side surfaces. The connector (300) has a pair of legs (302) that sandwich opposing side surfaces of the upper end of the shaft with a clamping portion (304), a step portion (306) formed on the inner surface of each of the legs (302) above the clamping portion (304), and a connecting portion (308) that connects the pair of legs (302) at their upper ends. By connecting the connecting portion (308) to the lower end of the rotating shaft (50), the rotating shaft imparts rotation to the shaft via the connector, and by engaging a protrusion (e.g., nut 146) integral with the shaft with the step portion, the connector is prevented from coming off the shaft.

[0011] According to the first aspect of the present invention, the rotating shaft can be connected to the shaft by using a connector appropriate for the shaft, so that the electric actuator can be applied to various types of water supply control devices.

[0012] A second invention is dependent on the first invention, and is an electric actuator in which a male or female thread is formed on the upper end of the shaft, and the protrusion is formed by a nut that screws into the male thread or a bolt that screws into the female thread.

[0013] In the second invention, a male thread (144) or female thread is formed on the upper end of the shaft of the water supply control device, and in the case of a male thread, a nut (146) screwed onto the male thread serves as the protruding part, and in the case of a female thread, the head of a bolt screwed into the female thread serves as the protruding part.

[0014] According to the second aspect of the present invention, the projection is engaged with the step, thereby preventing the shaft of the water supply control device from coming off the connector.

[0015] A third invention is dependent on the second invention and is an electric actuator further comprising a countersunk hole formed in a lower surface of the connecting portion of the connector, the countersunk hole receiving the male screw at the upper end of the shaft.

[0016] In the third aspect of the invention, a countersunk hole (312) is formed in the lower surface of the connecting portion (308). This countersunk hole (312) receives the male thread (144) at the upper end of the shaft, and a nut (146) screwed onto the male thread is engaged with the stepped portion.

[0017] According to the third aspect of the present invention, when the upper end of the shaft of the water supply control device is male threaded and the protrusion is formed by a nut, the connecting portion of the connector does not get in the way. Effect of the Invention

[0018] According to this invention, since the rotating shaft can be connected to the shaft via the connector, the electric actuator can be applied to various types of water supply control devices.

[0019] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the embodiments with reference to the drawings. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing an electric actuator according to an embodiment of the present invention installed in a water supply device and a drainage device in a farm field; [Diagram 2] 1 is a diagram showing the appearance of an electric actuator according to an embodiment of the present invention; [Diagram 3] FIG. 3 is a diagram illustrating the internal structure of the electric actuator of FIG. 2. [Figure 4] FIG. 4 is a partially enlarged view showing the main gear periphery in FIG. 3. [Diagram 5] FIG. 2 is an illustrative view showing an example of a first adaptor. [Figure 6] FIG. 3 is a diagram showing a state in which the electric actuator of FIG. 2 is attached to a water supply valve. [Figure 7] FIG. 6 is an exploded perspective view showing a main part of the embodiment. [Figure 8] 8A and 8B are diagrams showing an example of a connector, in which FIG. 8A is a perspective view and FIG. 8B is a front view. [Figure 9] 5 is a diagram showing the electric actuator shown in Figures 2-4 attached to another water supply device using a connector. FIG. [Figure 10] FIG. 13 is an illustrative view showing an example of a second adaptor. [Figure 11] FIG. 13 is an illustrative view showing an example of a third adaptor. [Figure 12] 10 is an illustrative view showing one example of a procedure for connecting the rotating shaft of the electric actuator and the shaft of the water supply device via a second actuator in the embodiment shown in FIG. 9. [Figure 13] FIG. 9 is a perspective view showing a main part of the embodiment. [Figure 14] 14A and 14B are diagrams showing another example of a connector, in which FIG. 14A is a perspective view and FIG. 14B is a front view. [Figure 15] 15 is an illustrative view showing an example of a procedure for connecting the rotating shaft of the electric actuator and the shaft of the water supply device in the embodiment of FIG. 9 via the connector shown in FIG. 14. [Figure 16] FIG. 1 is a perspective view showing an example of a restraint device. [Figure 17] FIG. 11 is a perspective view showing another example of a connector. [Figure 18] 18 is a diagram showing the state in which the electric actuator shown in FIGS. 2-4 is attached to the water supply device of the embodiment in FIG. 9 using the connector shown in FIG. 17 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] 1, an electric actuator 10 (hereinafter simply referred to as "actuator 10") according to one embodiment of the present invention includes a motor 38, a main gear 40, a rotating shaft 50, etc., and is attached to a water supply control device such as a water supply valve to operate a displacement mechanism of the water supply control device. In this embodiment, the actuator 10 is used in a farm water supply and drainage system 100 (hereinafter simply referred to as "system 100"), and is attached to both a water supply device 104 and a drainage device 106, which are examples of a water supply control device. That is, the actuator 10 is used as both a first electric actuator that operates a first displacement mechanism included in the water supply device 104, and a second electric actuator that operates a second displacement mechanism included in the drainage device 106.

[0022] First, the system 100 will be described. As shown in Fig. 1, the system 100 is a field facility for managing water in a field 102 by remote control or automatic control based on a pre-stored program, and is applied to a field 102 such as a paddy field in which a water supply device 104 and a drainage device 106 are installed. The field 102 is divided into a plurality of cultivated areas by ridges, and the water supply device 104 and the drainage device 106 are installed for each cultivated area.

[0023] The water supply device 104 is a device for controlling the water supply to the cultivated area (field 102), and has a displacement mechanism (first displacement mechanism) including a valve body, a partition body, etc. In this embodiment, the water supply device 104 uses an alfalfa-type water supply valve of the generally widespread R&R type (a type in which the shaft moves up and down with the shaft rotation).

[0024] 1 and 6, the water supply device 104 includes a cylindrical valve box 120. The upper half of the valve box 120 is covered with a dome-shaped cap 122, and a plurality of water outlet windows 124 are formed in the upper part of the side wall of the valve box 120 so as to be aligned in the circumferential direction. In addition, a bearing 126 having a female thread formed on the inner peripheral surface is provided at the upper end of the valve box 120. A shaft (valve stem) 128 having a male thread formed on its outer periphery is screwed into 126 so as to penetrate cap 122. A disk-shaped valve body 130 having a water-stop rubber 130a on its underside is provided at the lower end of this shaft 128. A valve seat 132 having a water passage port 132a is provided in the approximate center of valve box 120. When a rotational force about the axis is applied to shaft 128, shaft 128 and valve body 130 are moved up and down by the feed screw mechanism, and water passage port 132a of valve seat 132 is opened and closed. That is, water supply device 104 of this embodiment is provided with a first displacement mechanism including valve body 130 that moves up and down with the rotation of shaft 128.

[0025] Such a water supply device 104 is disposed, for example, in a water supply manhole 108, and attached to the downstream end of a branch pipe 112 branching off from an irrigation water pipeline 110 or an irrigation water channel. An actuator 10 is attached to the water supply device 104 via a first adapter 60, which will be described later, and the displacement mechanism (shaft 128 and valve body 130) of the water supply device 104 is operated by this actuator 10.

[0026] On the other hand, the drainage device 106 is a device for controlling drainage from the farm field 102, and has a displacement mechanism including a valve body or a partition body that displaces in response to the rotation of the shaft. In this embodiment, a water outlet having a water level setting function is used as the drainage device 106. Such a drainage device 106 is disposed, for example, in a drainage basin 114, and attached to the upstream end of a drainage pipe 118 that extends to a drainage channel 116. An actuator 10 is also attached to the drainage device 106 as described below, and the displacement mechanism of the drainage device 106 can be operated by this actuator 10.

[0027] 1, the water supply device 104 is disposed at one end of the field 102 and the drainage device 106 is disposed at the opposite end, but the positions of the water supply device 104 and the drainage device 106 can be changed as appropriate. For example, the water supply device 104 and the drainage device 106 may be disposed in close proximity to each other.

[0028] The system 100 in this embodiment is a system including a plurality of cultivation areas, and in addition to the actuators 10 attached to the water supply devices 104 and the drainage devices 106 installed in each cultivation area, a parent unit that only performs communication is installed, and the remaining actuators 10 are child units. The parent unit is wirelessly connected to a remote control terminal owned by a user, such as a smartphone, tablet terminal, PDA, or PC, via a network such as the Internet. Meanwhile, the child actuators 10 are wirelessly connected to the parent unit directly or via other child units by a wireless communication method conforming to a specific low-power wireless standard, and are wirelessly connected to a remote control terminal owned by the user via the parent unit.

[0029] It is advisable to use cloud computing for this wireless communication. For example, information acquired by each actuator 10 (information on the state of the water supply device 104 or the drainage device 106, such as the opening and closing degree of the valve body, and sensor information such as the field water level and air temperature) is transmitted to a cloud server as needed and stored. A user can access the cloud server from a remote control terminal to check the information acquired by each actuator 10, and manage the water in the field 102 by remotely controlling each actuator 10 using the remote control terminal.

[0030] However, the system 100 does not necessarily have to be a system that spans multiple cultivated areas, and the field 102 to which the system 100 is applied may be a field in which at least one water supply device 104 and one drainage device 106 are installed.

[0031] Next, a specific description will be given of the configuration of the actuator 10. As shown in Fig. 2 to Fig. 4, the actuator 10 has a main body casing made of synthetic resin such as hard polyvinyl chloride. The main body case 20 includes a cylindrical side wall 22 and a top wall 24 that seals the upper end of the side wall 22. The lower end of the side wall 22 is tapered in diameter in a stepped manner, and this tapered portion becomes a fitting portion 26 that is fitted into an upper opening of a first adapter 60, which will be described later. The height dimension of the main body case 20 is, for example, 300 mm, and the outer diameter of the main body case 20 is, for example, 200 mm.

[0032] A solar cell panel 28 is attached to the upper surface of the top wall 24 of the main body case 20. The solar cell panel 28 is a rectangular package of multiple solar cells made of reinforced glass, a sealing material, etc., and is supported by a holder 30. The holder 30 is formed of metal, resin, or the like, and includes, for example, a rectangular frame 30a provided so as to cover the periphery of the solar cell panel 28, and a support plate 30b provided on the lower surface of the frame 30a and bent at a predetermined angle.

[0033] The main body case 20 accommodates a control panel 32, an antenna 34, a storage battery 36, a motor 38, a main gear 40, etc.

[0034] Although not shown, the control panel 32 is provided with a control section including a CPU and memory, a wireless communication section for wirelessly communicating with other devices, and a switch for the main power supply, etc. The CPU of the control section is responsible for the overall control of the actuator 10, and controls the driving of the motor 38, etc., based on a control program stored in the memory. The wireless communication section wirelessly communicates with external devices, such as a remote control terminal owned by the user and other actuators 10, via the antenna 34, as described above.

[0035] The storage battery 36 stores the power generated by the solar panel 28. The motor 38 is driven by the power stored in the storage battery 36, that is, the power generated by the solar panel 28. A small gear 42 is provided at the tip of an output shaft 38a of the motor 38, and the main gear 40 is connected to the small gear 42 to receive driving force from the motor 38 and rotate around its axis.

[0036] In this embodiment, a motor with an encoder is used as the motor 38. The encoder of the motor 38 outputs a pulse signal corresponding to the rotation direction and the number of revolutions of the output shaft 38a to the CPU of the control unit. The CPU of the control unit calculates the position of the valve body 130 of the water supply device 104 or the partition body 142 of the drainage device 106 based on the pulse signal input from the encoder, that is, the rotation direction and the number of revolutions of the output shaft 38a. That is, the encoder is used as a position detection unit that detects the position of the valve body 130 or the partition body 142. However, the encoder that functions as the position detection unit does not necessarily have to be provided in the motor 38, and the encoder can be provided in the main gear 40 to calculate the position of the valve body 130 or the partition body 142 based on the rotation direction and the number of revolutions of the main gear 40. Furthermore, the control panel 32 is provided with a current value detection unit such as a current sensor (current transformer) that detects the motor current value, and the detection data in the current value detection unit is input to the CPU of the control unit.

[0037] The main gear 40 is a double-boss type gear, and has a cylindrical shaft portion (boss portion) 40a extending in the vertical direction, and a disk-shaped gear portion 40b having gear teeth formed on the outer circumferential surface. A disk-shaped first bearing 44, which also serves as the bottom wall of the main body case 20, is provided at the lower end of the side wall 22 of the main body case 20, and a disk-shaped second bearing 48 supported by a plurality of support portions 46 is provided above the first bearing 44. Both ends of the shaft portion 40a of the main gear 40 are rotatably held by the first bearing 44 and the second bearing 48.

[0038] A substantially cylindrical rotating shaft 50 is inserted into the shaft portion 40a of the main gear 40. In other words, the rotating shaft 50 is provided so as to pass through the axial center of the main gear 40. The lower end of the rotating shaft 50 The portion is formed with a coupling portion 50a that is non-rotatably connected to the shaft 128 of the water supply device 104 or an upper end portion 308b (described later) of a connector 300 (described later).

[0039] Further, a key groove (first key groove) 40c extending along the axial direction is formed on the inner peripheral surface of the shaft portion 40a of the main gear 40, and a sliding key (first sliding key) 50b that fits into the key groove 40c is formed on the outer peripheral surface of the rotating shaft 50 so as to extend along the axial direction. Due to the sliding key structure consisting of such key groove 40c and sliding key 50b, the rotating shaft 50 rotates together with the rotation of the main gear 40, and is able to slide in the axial direction relative to the shaft portion 40a of the main gear 40.

[0040] Here, a spline structure or a serration structure may be used as a method for providing a rotating shaft that rotates with the gear and can slide in the axial direction of the gear. However, with a spline structure or a serration structure, it is necessary to cut multiple projections and recesses extending along the axial direction on the outer peripheral surface of the rotating shaft, and also to cut multiple projections and recesses on the inner peripheral surface of the gear shaft, which increases the manufacturing cost. Therefore, in this embodiment, the sliding key structure with the above-mentioned simple structure is adopted, because this allows the manufacturing cost to be significantly reduced.

[0041] However, since the rotating shaft 50 moves up and down while rotating, i.e., a torsional force acts on the rotating shaft 50, simply adopting a sliding key structure may result in the rotational balance of the rotating shaft 50 becoming poor, causing the rotating shaft 50 to malfunction.

[0042] Therefore, in this embodiment, a first thrust bearing 52 is provided between the lower surface of the gear portion 40b of the main gear 40 and the upper surface of the first bearing 44, and a second thrust bearing 54 is provided between the upper surface of the gear portion 40b of the main gear 40 and the lower surface of the second bearing 48. As the thrust bearings 52, 54, a known thrust ball bearing or the like may be used.

[0043] By providing the thrust bearings 52 and 54 in this way, a sliding key structure is adopted. This allows the rotating shaft 50 to move up and down while rotating in a well-balanced manner, thereby reducing the rotational torque during operation, i.e., the load on the motor 38. This is particularly effective when tightening (at the end of the closing operation) when the load is at its maximum. This allows the motor 38 to be made smaller and consume less power (electricity saving). Furthermore, the reduced rotational torque also improves the durability of the main gear 40, bearings 44, 48, and rotating shaft 50.

[0044] That is, by combining the sliding key structure with the thrust bearings 52, 54, This makes it possible to reduce manufacturing costs and to operate the rotating shaft 50 smoothly.

[0045] As described above, the driving force of the motor 38 is applied to the rotary shaft 50 via the small gear 42 and the main gear 40, and these gears 40, 42 constitute a transmission mechanism.

[0046] In addition, the efficiency of reducing the motor load of the actuator 10 of this embodiment is greatly increased, and the effect of reducing the motor load by the thrust bearings 52, 54 has already been confirmed by the inventors. Therefore, detailed description thereof will be omitted.

[0047] Although not shown, the field 102 is appropriately provided with sensors such as a water level sensor, such as an ultrasonic sensor, for detecting the field water level, a temperature sensor for detecting the air temperature, a pressure sensor for detecting the air pressure, a moisture sensor for detecting the soil moisture, etc. Sensor information, such as the field water level and air temperature, detected by each sensor is input to the control unit of the actuator 10.

[0048] Next, referring to FIG. 5, a first step for attaching the actuator 10 to the water supply device 104 will be described. An example of the adaptor 60 will be described. As shown in Fig. 6, the first adaptor 60 includes a cylindrical portion 62, a brim-shaped first connecting portion 64 that protrudes outward from the upper end of the cylindrical portion 62, and a ring-shaped second connecting portion 66 that protrudes inward from the lower end of the cylindrical portion 62 and has a through hole 66a in its center. The first connecting portion 64 is formed with a plurality of bolt holes (not shown) arranged in the circumferential direction. The second connecting portion 66 is also formed with a plurality of bolt holes (not shown) arranged in the circumferential direction. The bolt holes of the second connecting portion 66 may be elongated holes that are long in the circumferential direction.

[0049] As shown in FIG. 6, when the actuator 10 is attached to the water supply device 104 using the first adaptor 60, the fitting portion 26 of the main body case 20 is fitted into the cylindrical portion 62 of the first adaptor 60, and the first connection portion 64 of the first adaptor 60 is bolted to the bottom wall of the main body case 20 of the actuator 10. Also, the second connection portion 66 of the first adaptor 60 is bolted to the cap 122 and the bearing 126 of the water supply device 104. At this time, by making the bolt hole formed in the second connection portion 66 a long hole that is long in the circumferential direction, the first adaptor 60 and the actuator 10 can be adjusted in angle in the circumferential direction relative to the water supply device 104. Furthermore, the upper end portion of the shaft 128 of the water supply device 104 protrudes upward from a through hole 66a formed in the second connection portion 66 of the first adaptor 60, and is non-rotatably connected to the coupling portion 50a of the rotating shaft 50 of the actuator 10.

[0050] 7, a slit 70 constituting a coupling portion 50a is formed at the lower end of the rotating shaft 50. The slit 70 receives the shaft 128 of the water supply device 104. That is, at the upper end of the shaft 128, for example, by cutting out the sides of a cylinder, a pair of opposing side surfaces 134 fit into the slit 70, that is, an inner surface 72 defining the slit 70 sandwiches the side surfaces 134, thereby non-rotatably connecting the shaft 128 to the rotating shaft 50 of the actuator 10.

[0051] However, the upper end of the shaft 128 may be formed as a square prism having a pair of opposing side surfaces 134 that fit into the slits 70 of the rotating shaft 50 .

[0052] In the water supply device 104 to which the actuator 10 is attached in this manner, for example, when a user uses a remote control terminal to send an operation instruction (control signal) indicating full closure, full open, or an arbitrary opening degree to the actuator 10, the control unit (CPU) of the actuator 10 drives the motor 38 in response to the operation instruction. The driving force of the motor 38 is transmitted to the main gear 40 constituting the transmission mechanism, and the main gear 40 rotates and the rotating shaft 50 rotates. As a result, a rotational force is applied to the shaft 128 connected to the rotating shaft 50. The shaft 128 to which the rotational force is applied is moved up and down by a feed screw mechanism of the shaft 128 itself and the bearing 126, and the valve body 130 is moved to a fully open position, a fully closed position, or the like. In addition, the rotating shaft 50 moves up and down so as to penetrate the shaft portion 40a of the main gear 40 in accordance with the up and down movement of the shaft 128. As a result, the up and down movement of the shaft 128 is absorbed without requiring a large space in the up and down direction.

[0053] 7, a relatively deep countersunk hole 74 is formed above the slit 70 in the rotating shaft 50. This countersunk hole 74 receives a retaining bolt 136 attached to the upper end of a connector 300 in the embodiment shown in FIG. 9, which will be described later. Furthermore, at the position of this countersunk hole 74, the rotating shaft 50 is formed with female threads 76 at two different positions in the axial direction of the rotating shaft 50 so as to penetrate the peripheral side surface of the rotating shaft 50 which defines the countersunk hole 74.

[0054] Next, an example of a connector 300 for attaching the actuator 10 to a water supply device of another type will be described with reference to Fig. 8. It should be noted in advance that the dimensions, height, width, and spacing of each part described below are all examples and are not limiting. put.

[0055] Connector 300 is made of a metal such as steel, and is arch-shaped (gate-shaped) when viewed from the front (FIG. 8(B)), with an overall width W of 37 mm, height H1 of 55 mm, and thickness T1 of 17 mm. Connector 300 includes a pair of legs 302 that face each other at a distance. The lower ends of legs 302 are formed as clamping portions 304 for clamping opposing side surfaces 142 (similar to side surface 134 in FIG. 7) formed on square column portion 140 at the upper end of shaft 128 of water supply device 104, as described below. The distance G1 between opposing inner faces of clamping portion 304 is 14.0 mm, and height H2 of clamping portion 304 is 18 mm.

[0056] A step 306 is formed on the inner surface of each leg 302 above the clip 304. In this embodiment, the distance G2 between the opposing inner surfaces of the step 306 is 24 mm. The height H3 of the step 306 is 10 mm.

[0057] The upper ends of a pair of legs 302 of the connector 300 are connected to each other by a connecting portion 308. The connecting portion 308 is composed of a lower portion 308a, which has the same thickness as the legs, and an upper portion 308b, which is integrally formed thereon and has a thickness T2 (13 mm) thinner than the thickness T1 of the lower portion 308a, and has an overall height H4 of 17 mm. The height of the upper portion 308b alone is 13 mm. A female thread 310 is formed in the center of the width of the connecting portion 308, extending from the upper portion 308b to a part of the lower portion 308a. This female thread 310 is used to attach the above-mentioned retaining bolt 136.

[0058] Furthermore, a countersunk hole 312 is formed above the lower surface of the lower portion 308a at the center in the width direction of the connecting portion 308. This countersunk hole 312 is formed to a depth of 10 mm, and receives a male screw 144 formed at the upper end of the shaft 128, which will be described later.

[0059] Here, an embodiment in which the actuator 10 shown in FIGS. 2-4 is applied to a water supply device 104 of a type different from that of the embodiment in FIG. 6 using this connector 300 will be described with reference to FIGS.

[0060] First, in the embodiment of FIG. 9, a second adaptor 314 and a third adaptor 316 shown in FIGS. 10 and 11 are used.

[0061] Second adaptor 314 in Fig. 10 is made of a metal such as aluminum, and includes a disk portion 318 and a wall 320 rising from the upper surface of disk portion 318. An internal thread 321 is formed in wall 320. A through hole 322 is formed in the center of disk portion 318 for passing shaft 128 of water supply device 104 through. Although not clear in Fig. 10, disk portion 318 has a screw hole formed for attaching second adaptor 314 to water supply device 104 shown in Fig. 9.

[0062] 11 is also made of a metal such as aluminum, and has a similar configuration to the first adapter 60 shown in FIG. 5. That is, the third adapter 316 includes a cylindrical portion 324 and a flange-shaped connecting portion 326 that protrudes outward from the upper end of the cylindrical portion 324. Since the third adapter 316 is coupled to the second adapter 314 as described below, a hole 325 is formed in the cylindrical portion 324 at a position corresponding to the female thread 321. However, unlike the first adapter 60, the lower end of the cylindrical portion 324 does not have a bottom surface, but is open.

[0063] The second adapter 314 and the third adapter 316 are assembled as shown in FIG.

[0064] The water supply device 104 shown in FIG. 9 is of the type in which a valve is directly opened and closed by a handle (not shown). 6 embodiment, does not have a flat upper surface like the water supply device 104 in the embodiment in Fig. 6. Therefore, in this embodiment, when no water pressure is applied, the handle is removed, the screws (not shown) in the bearing lid part above the water supply valve are removed, and replaced with a specified hexagonal support 138. For example, if the bearing lid part has four screws, the first one is changed to a hexagonal support 138. For example, if the relevant screws have six screws, every other one, a total of three, are changed to hexagonal supports 138.

[0065] Since a female screw is formed on the upper end of each hexagonal support 138, a male screw is used to attach the disk part 318 of the second adaptor 314 shown in Fig. 10 to the upper end of the hexagonal support 138. In this state, the upper end of the shaft 128 shown in Fig. 9 passes through the through hole 322 of the disk part 318 of the second adaptor 314 and is exposed above the disk part 318, and the upper end of the water supply device 104 can be made flat.

[0066] In this state, next, as shown in FIG. 12(A), a connector 300 shown in FIG. 8 is attached to the upper end of the shaft 128.

[0067] The upper end of the shaft 128 is formed as a rectangular columnar portion 140, for example as shown in Fig. 12, and a pair of opposing side surfaces 142 are formed. However, the side surfaces 142 may be formed by cutting the side surfaces of a cylinder, similar to the side surfaces 134 shown in Fig. 7, and a male thread 144 is formed extending upward from the upper surface of the rectangular columnar portion 140. Then, a nut 1146 (a round nut in this embodiment, but a square nut may also be used) is screwed onto the upper end of the male thread 144, the nut 146 is received in the stepped portion 306 of the connector 300, and the pair of side surfaces 142 of the rectangular columnar portion 140 of the shaft 128 is disposed within the clamping portion 304 of the connector 300. However, this positioning work is performed by screwing the nut 146 onto the upper end of the male thread 144, and then from the side of the connector 300, i.e., from the front (FIG. 8(B)) or back side of the connector 300, placing the nut 146 on the step portion 306 and the pair of side surfaces 142 inside the clamping portion 304. This state is shown in FIG. 12(A). At this time, the tip of the male thread 144 has not yet entered the countersink 312, and the side surfaces 142 of the rectangular column portion 140 of the shaft 128 have not yet entirely fit inside the clamping portion 304.

[0068] Next, the nut 146 is turned to move it toward the base end of the male screw 144. Then, since the position of the nut 146 is restricted by the stepped portion 306 of the connector 300, the male screw 144 is relatively displaced upward as the nut 146 is turned, and the shaft 128 is also displaced upward, resulting in the state shown in FIG. 12(B). In this state, the tip of the male screw 144 enters the countersunk hole 312, and since the nut 146 is restricted by the stepped portion 306, the male screw 144 does not fall out of the countersunk hole 312. In addition, the side surface 142 of the rectangular column portion 140 of the shaft 128 is completely contained within the clamping portion 304.

[0069] 12(C), the retaining bolt 136 is attached to the female thread 310 formed in the upper portion 308b of the connecting portion 308 of the connector 300. The retaining bolt 136 has a male thread 136a at the bottom, and a small diameter portion 148 is formed thereon. The male thread 136a is screwed into the female thread 310, thereby attaching the retaining bolt 136 to the upper side of the connecting portion 308 (upper portion 308b) of the connector 300.

[0070] 12(D), the retaining bolt 136 is inserted into the countersunk hole 74 formed in the rotating shaft 50 of the actuator 10. At this time, the slit 70 (FIG. 7) formed in the lower end of the rotating shaft 50 covers the upper portion 308b of the connecting portion 308 of the connector 300, as shown in FIG. 12. In other words, the upper portion 308b of the connecting portion 308 of the connector 300 is sandwiched between the inner surface 72 (FIG. 7) of the slit 70, thereby connecting the connector 300 to the rotating shaft 50 of the actuator 10 so that it cannot rotate. In this state, a set screw 150 is screwed into one of the two female threads 76 formed on the side of the countersunk hole 74 of the rotating shaft 50, The small diameter portion 148 of the retaining bolt 136 is pressed down. In other words, the set screw 150 that engages with the small diameter portion 148 of the retaining bolt 136 constitutes an engagement portion. Therefore, the connector 300 will not fall off the rotating shaft 50.

[0071] On the other hand, as described above, the engagement between the nut 146 and the stepped portion 306 prevents the shaft 128 from falling off the connector 300. Furthermore, the side surface 142 of the rectangular column portion 140 of the shaft 128 is clamped by the clamping portion 304 of the connector 300, so that the shaft 128 is non-rotatably connected to the rotating shaft 50 via the connector 300.

[0072] Finally, as shown in Figure 9, the third adapter 316 is attached to the lower end of the actuator 10, and a bolt is screwed through a hole 325 provided in the cylindrical portion 324 of the third adapter 316 into the female thread 321 provided in the wall 320 of the second adapter 314, thereby joining it to the second adapter 314, thereby connecting the connecting parts between the actuator 10 and the water supply device 104, resulting in the state shown in Figure 9.

[0073] In this way, in the embodiment of Fig. 9 as well, the actuator 10 can be attached to the water supply device 104 and operated in the same manner as in the embodiment of Fig. 6. That is, in the water supply device 104 to which the actuator 10 is attached, for example, when a user uses a remote control terminal to send an operation instruction (control signal) indicating full close, full open, or an arbitrary opening degree to the actuator 10, the control unit (CPU) of the actuator 10 drives the motor 38 in response to the operation instruction. The driving force of this motor 38 is transmitted to the rotating shaft 50 via a transmission mechanism, causing the rotating shaft 50 to rotate. A rotational force is applied to the shaft 128 connected to the rotating shaft 50 via a connector 300.

[0074] In the above-described embodiment, in order to prevent shaft 128 from falling off connector 300 by engaging with stepped portion 306 of connector 300, an upwardly extending male thread 144 is formed on the upper end of shaft 128, and a nut 146 is screwed onto the male thread 144. Nut 146 protrudes in a direction perpendicular to the axial direction of shaft 128, thereby engaging with stepped portion 306.

[0075] However, the nut 146 may be replaced with a bolt head (not shown). In this case, a female thread (not shown) may be formed extending downward from the upper surface of the rectangular column portion 140 of the shaft 128, a bolt may be screwed into the female thread, and the bolt head may project in a direction perpendicular to the axial direction of the shaft 128 to engage with the stepped portion 306.

[0076] Connector 300 shown in Fig. 14 is a connector suitable for cases where high torque is required for actuator 10. In actuator 10 of the embodiment, slit 70 is provided at the lower end of rotating shaft 50, and shaft 128 of water supply device 104 or connector 300 is connected non-rotatably by slit 70 (inner surface 72 thereof), so that when the torque for rotating shaft 128 of water supply device 104 must be increased, there is a risk that rotating shaft 50 will tear at slit 70. For this reason, in the next embodiment, connector 300 capable of reinforcing the lower end of rotating shaft 50 is used.

[0077] The connector 300 in Fig. 14 differs from the connector 300 shown in Fig. 8 except for the following points. That is, the overall thickness T3 is thicker than the thickness T1 in Fig. 8, and is, for example, 24 mm. However, the thickness T2 of the upper part 308b of the connector 308 is set to be the same as the thickness T2 in Fig. 8. This is because the upper part 308b needs to fit into the slit 70 of the rotating shaft 50, similar to the embodiment in Fig. 9.

[0078] The reason for making the thickness T3 thicker is that the upper portion 308b is provided with stoppers on both sides separated by grooves 328. 15. That is, a groove 328 is formed by the stopper 326 on the outer side in the thickness direction of the upper portion 308b. The width in the thickness direction of the groove 328 is selected to be a width capable of receiving the maximum thickness from the inner surface 72 of the slit 70 of the rotating shaft 50 shown in FIG. 7 to the circumferential side surface of the rotating shaft 50, that is, a width capable of receiving the slit forming portion 78 shown in FIG.

[0079] FIG. 15 shows a procedure for connecting the rotating shaft 50 and the shaft 128 using the connector 300 shown in FIG.

[0080] The method of connecting the shaft 128 to the connector 300 shown in Figure 15(A) is as previously described with reference to Figure 12. The method of connecting the rotating shaft 50 to the connector 300 in this state is basically the same as the method described with reference to Figure 12.

[0081] The slit 70 of the rotating shaft 50 is placed over the upper part 308b of the connecting part 308 of the connecting tool 300, and at this time, as shown in FIG. 15(B), the slit forming part 78 of the rotating shaft 50 that defines the slit 70 is inserted into the groove 328 of the connecting tool 300. Therefore, this slit forming part 78 is sandwiched between the upper part 308b and the stopper 326. Therefore, the stopper 326 can restrain the slit forming part 78 that defines the slit 70 of the rotating shaft 50 from the outside. In other words, the stopper 326 constitutes a restraining means that restrains the rotating shaft 50 from the outside at the part of the slit 70. Thereby, even when a high torque is required to rotate the shaft 128 of a water supply control device such as the water supply device 104, the rotating shaft 50 can be prevented from breaking or being destroyed.

[0082] In the connector 300 shown in FIG. 14, the height of the stopper 326 (depth of the groove 328) may be a height (depth) that can hold the rotating shaft 50 from the outside in at least a part of the slit 70, but it is preferable that the height (depth) be a height (depth) that can restrain the rotating shaft 50 from the outside over the entire depth of the slit 70.

[0083] As another embodiment of the restraining means for restraining such a rotating shaft 50 from the outside at the slit 70, a restraining device 330 shown in Fig. 16 is used. This restraining device 330 is made of a metal such as steel, and has a hole 332 formed in the center. The diameter of this hole 332 is large enough to allow the rotating shaft 50 to pass through. However, the outer diameter, i.e., the thickness, of the restraining device 330 is arbitrary, but may be determined according to the strength required for the restraining device 330. The thickness (vertical direction) of the restraining device 330 may also be determined according to the strength required.

[0084] In order to use such a restraining device 330, the connecting device 300 is also modified as shown in Fig. 17. In Fig. 17, in the connecting device 300 of this embodiment, the width of the upper part 308b of the connecting portion 308 is narrower than that of the connecting device 300 of the example in Fig. 8. In other words, both sides of the upper part 308b as viewed from the front are cut out, and restraining device receivers 334 are formed on both sides of the front of the upper part 308b.

[0085] Figure 18 shows the state in which the actuator 10 and the water supply device 104 are connected using the connector 300 and the restraint 330. In this embodiment, first, as in the previous embodiment of Figure 9, the second adaptor 314 is attached to the top of the hexagonal support 138. Then, before screwing in the set screw 150, the rotating shaft 50 is passed through the restraint 330, and then the rotating shaft 50 and the shaft 128 are connected via the connector 300 using the procedure described with reference to Figure 11. However, the set screw 150 is not screwed in yet.

[0086] Thereafter, the restraining device 330 through which the rotating shaft 50 has been passed in advance is lowered until it contacts the restraining device receiver 334. Then, as shown in FIG. 18, the lower end of the rotating shaft 50 is surrounded by the restraining device 330. Then, as in the embodiment shown in FIG. 9, the retaining bolt 136 is finally engaged with the set screw 150. Then, as shown in Figure 18, a third adaptor 316 is attached to the lower end of the actuator 10 and a bolt is screwed into a female thread 321 on a wall 320 of the second adaptor 314 through a hole 325 on the cylindrical portion 324 of the third adaptor 316, thereby joining it to the second adaptor 314, thereby connecting the connecting parts between the actuator 10 and the water supply device 104 and resulting in the state shown in Figure 18.

[0087] 18, the restraining device 330 can also restrain the slit forming portion 78 (FIG. 15) that defines the slit 70 of the rotating shaft 50 from the outside. In other words, the restraining device 330 constitutes a restraining means that restrains the rotating shaft 50 from the outside at the portion of the slit 70. This makes it possible to prevent the rotating shaft 50 from breaking or being destroyed, even when a high torque is required to rotate the shaft 128 of a water supply control device such as the water supply device 104.

[0088] However, compared to using a restraining means (stopper 326) that is integrated with connector 300, using a restraining means (restraining device 330) separate from connector 300 has the drawback that it takes more time to attach and remove.

[0089] The restraining means separate from the connector 300 is not limited to the restraining device 330 shown in Figs. 16-18, but may also be, for example, a stainless steel band.

[0090] In the previous embodiment, the slit 70 of the rotating shaft 50 is fitted over the upper portion 308b of the connector 300 to connect the rotating shaft 50 and the connector 300, but the connection structure between the rotating shaft 50 and the connector 300 is not limited to this.

[0091] As another embodiment, for example, a recess may be formed in (the upper portion 308b) of the connecting portion 308 of the connector 300, and a protrusion that fits into the recess may be formed on the lower end surface of the rotating shaft 50, and the two may be screwed together with the protrusion fitted into the recess.

[0092] Furthermore, as another embodiment, for example, a method can be considered in which the connecting portion 308 (upper portion 308b) of the connector 300 is made cylindrical with the same diameter as the rotating shaft 50, and this cylindrical portion is connected to the lower end of the rotating shaft 50 with a commercially available coupling member.

[0093] The specific values ​​of dimensions and shapes given above are merely examples and can be changed as appropriate according to the needs of product specifications, etc. [Explanation of symbols]

[0094] 10... Electric actuator 20...Main body case 50 …Rotation axis 70 ... Slit 72 ...Inner 74 … Counterbore 76 … Female thread 78 ... Slit forming part 128 ... shaft 104 ... Water supply device (water supply control device) 106 ...Drainage device (water supply control device) 134 ... Side 136 ... Lock bolt 140 … Square column section 142 ... Side 144 ... Male thread 146 ... Nut 148 ... Small diameter 150 ... Set screw 300 ... Connector 302...legs 304 ... Clamping part 306 … Step 308…Connection part 308a…lower part 308b…upper part 310 … Female thread 312 … Counterbore

Claims

1. An electric actuator is attached to a water supply control device having a displacement mechanism that controls water supply by displacing a valve body or a partition body that is linked to rotation of a shaft, and operates the displacement mechanism, Main unit case, A motor provided in the main body case; a transmission mechanism provided in the main body case and configured to transmit the driving force of the motor; and a rotation shaft that is rotated by the motor via the transmission mechanism and has a lower portion extending downwardly from the main body case; and A connector for connecting the rotating shaft to the shaft, an upper end of the shaft having at least one pair of opposing side surfaces; The connector has a pair of legs that sandwich the opposing side surfaces of the upper end of the shaft with a clamping portion, a step portion formed on the inner surface of each of the legs above the clamping portion, and a connecting portion that connects the pair of legs at their respective upper ends, By connecting the connecting portion to the lower end of the rotating shaft, the rotating shaft imparts rotation to the shaft via the connecting tool, An electric actuator that prevents the connector from coming off the shaft by engaging a protrusion integral with the shaft with the step portion.

2. 2. The electric actuator according to claim 1, wherein a male thread or a female thread is formed on an upper end of the shaft, and the protrusion is formed of a nut that screws onto the male thread or a bolt that screws onto the female thread.

3. 3. The electric actuator of claim 2, further comprising a counterbore formed in a lower surface of the coupling portion of the coupling device, the counterbore receiving the male threads on the upper end of the shaft.

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