JP2000350409A - Valve-driving actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an improved small-sized valve-driving actuator with an abnormal load detection mechanism which can be set easily. SOLUTION: An abnormal load detecting means has a rotating member 21 which is engaged with a worm shaft 5 and turned according to the movement of the worm shaft 5 in the axial direction, a gear 22 which is connected to the rotary member 21 and amplifies the rotation value of the rotary member 21, and a detection shaft 23 linked with the gear 22. The detecting means detects abnormal load according to the rotation value of the detection shaft 23 and is easily to set on a small-sized valve-driving actuator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve drive actuator, and more particularly to a valve drive actuator which is displaceable in the axial direction within a range of elastic deformation of a disc spring having a worm and arranged in the axial direction. A worm shaft rotatably provided, a drive motor for rotating the worm shaft, an output shaft connected to a worm wheel fitted with the worm, and the worm shaft for urging the disc spring. A valve drive actuator comprising: abnormal load detecting means for detecting an abnormal load applied to the output shaft based on the amount of movement of the worm shaft in the axial direction when the worm shaft moves in the axial direction. It is about.

[0002]

2. Description of the Related Art FIG. 4 shows a schematic configuration example of a valve driving actuator attached to a valve such as a butterfly valve for driving the valve. In FIG. 4, the output shaft 7 is connected to a valve such as a butterfly valve. In the valve driving actuator, the electric motor 1
Is transmitted to the output shaft 7 via the reduction unit D. The reduction portion D includes a worm gear including spur gears 2 to 4, a worm wheel 6a and a worm 6b. The spur gears 2 to 4 connect the electric motor 1 and the worm shaft 5 having the worm 6b. That is, when the electric motor 1 rotates, the rotation is controlled by the spur gears 2 to 4.
Is transmitted to the worm shaft 5 after being decelerated by
The worm shaft 5 also rotates. The worm wheel 6a is mounted on the output shaft 7, and when the worm shaft 5 rotates, the rotation is transmitted to the output shaft 7 after the worm gear performs deceleration and rotation shaft conversion. , The output shaft 7 rotates. Further, the rotation of the electric motor 1 is automatically stopped at a set opening degree such as, for example, full open or full close. The automatic stop of the electric motor 1 is performed by an automatic stop mechanism B including a limit cam 9, a dog 10, and a limit switch 11. The limit cam 9 is attached to a shaft 8 connected to the output shaft 7. When the output shaft 7 rotates, the shaft 8 also rotates. The limit cam 9 is provided with a groove in its circumferential direction, and the dog 10
Is removably secured. The position of the dog 10 on the groove is set by the user according to a desired opening degree such as full opening or full closing. When the shaft 8 rotates and the dog 10 attached to the limit cam 9 rotates, it contacts the limit switch 11. A signal from the limit switch 11 is output to the electric motor 1, and the electric motor 1 is stopped at a set angle set by a user, for example, fully open or fully closed. In the valve driving actuator, a manual handle is also connected to the worm shaft 5 via a clutch mechanism.
And manual drive using the above-mentioned manual handle can be switched. By the way, when the valve to which the valve driving actuator is attached is restrained, or when the switch in the closing direction of the limit switch 11 fails or the setting is shifted, an abnormality occurs in the automatic stop mechanism, and the valve stop position is set. In the case where the operation is continued beyond the above, an abnormal torque larger than the torque required for the actuator to normally drive the valve is applied to each part of the valve driving actuator. If the above constrained state continues, the windings of the electric motor will burn out, or a thermal switch to prevent burning will operate,
During the operation, the electric motor becomes inoperable.
For this reason, in the valve driving actuator described above,
It is desirable to have a function to detect an abnormal load due to a cause such as valve restriction. A valve driving actuator having a function of detecting such an abnormal load is described in, for example, Japanese Patent Publication No. Sho 58-44904. The valve driving actuator described in the above publication operates a driven portion via a rotation mechanism that is driven to rotate by a driving motor. The rotation mechanism includes a worm, a worm wheel, and a worm shaft, and the worm shaft is configured to be displaceable in the axial direction against a spring by a reaction of a load torque. When the amount of displacement of the worm shaft in the axial direction becomes a predetermined amount, the torque switch detects that an abnormal load has occurred, and the drive motor is stopped.

[0003]

If the valve driving actuator is provided with a function of detecting an abnormal load as in the technique described in the above-mentioned publication, the mechanism for detection becomes complicated, and the size of the mechanism becomes small. It was difficult to mount. Also,
The change in the detection amount was small, and there were some difficulties in setting. An object of the present invention is to provide a small-sized valve driving actuator having an abnormal load detecting mechanism that can be easily set by improving the valve driving actuator in order to solve the problems in the conventional technology. It is the purpose.

[0004]

In order to achieve the above object, the invention according to claim 1 is characterized in that it is displaceable in the axial direction within a range of elastic deformation of a disc spring provided with a worm and arranged in the axial direction. A worm shaft rotatably provided around the shaft center,
A drive motor for rotationally driving the worm shaft, an output shaft connected to a worm wheel fitted with the worm, and the worm shaft moved in the axial direction against the bias of the disc spring. An abnormal load detecting means for detecting an abnormal load applied to the output shaft based on an amount of movement of the worm shaft in the axial direction, wherein the abnormal load detecting means comprises: A rotating member that engages with the worm shaft and rotates in accordance with the amount of movement of the worm shaft in the axial direction; a speed reducing member connected to the rotating member to amplify the amount of rotation of the rotating member; And a detection shaft configured to detect an abnormal load applied to the output shaft based on the amount of rotation of the detection shaft. In the valve driving actuator according to the first aspect, when the worm shaft moves in the axial direction against the disc spring, the amount of movement of the worm shaft in the axial direction is increased by the rotating member engaged with the worm shaft. Converted to rotation amount.
The rotation amount of the rotating member is amplified by the speed reducing member.
The rotation amount amplified by the speed reduction member is detected by a detection shaft, and an abnormal load applied to the output shaft is detected based on the rotation amount detected by the detection shaft. According to the valve driving actuator according to the first aspect of the present invention, the amount of movement of the worm shaft is amplified by a simple configuration to detect an abnormal load. Can be provided.

A second aspect of the present invention is a worm shaft provided with a worm, which is displaceable in the axial direction within a range of elastic deformation of a disc spring arranged in the axial direction and is rotatable about the axis. A drive motor for rotationally driving the worm shaft, an output shaft connected to a worm wheel fitted with the worm, and the worm shaft moving in the axial direction against the bias of the disc spring. An abnormal load detecting means for detecting an abnormal load applied to the output shaft based on an amount of movement of the worm shaft in the axial direction when the worm shaft moves, wherein the abnormal load detecting means comprises: A magnetic member having magnetism attached to the worm shaft, and a guide groove provided along the axial direction of the worm shaft to generate a signal when facing the magnetic member. Comprising a signal generator, based on the signal output from the signal generator is configured as a valve driving actuator characterized by comprising detecting an abnormal load applied to the output shaft. According to a third aspect of the present invention, in the valve driving actuator according to the second aspect, a speed reduction unit in which the worm shaft is disposed;
The gist is that the detection unit in which the signal generator is arranged is separated by a partition. Claim 2 or 3 above
In the valve driving actuator described in (1), when the worm shaft moves in the axial direction against the disc spring and the magnetic member attached to the worm shaft reaches the position at the time of abnormal load, the signal generator Is detected by According to such a valve driving actuator according to claim 2 or 3,
Abnormal load is detected by a simple configuration using only a very small magnetic member and a signal generator, so that it is possible to reduce the size. In addition, it is only necessary to move the signal generator along the guide groove. The settings can be easily changed.

Furthermore, according to the valve driving actuator of the third aspect, the deceleration unit and the detection unit can be completely separated from each other. Both maintenance can be performed easily. According to a fourth aspect of the present invention, in the valve drive actuator according to any one of the first to third aspects, the abnormal load detecting means includes a predetermined valve shut-off torque in addition to the detection of the abnormal load. The gist of the present invention is that it also performs the detection. According to the valve driving actuator according to the fourth aspect, the valve driving actuator according to any one of the first to third aspects,
The security of the closed position of the valve can be increased. According to a fifth aspect of the present invention, in the valve driving actuator according to any one of the first to fourth aspects, when the abnormal load detecting means detects an abnormal load applied to the output shaft,
The gist of the present invention is to stop the drive motor and to output a signal indicating the occurrence of an abnormal load to the outside. According to the valve driving actuator according to the fifth aspect, in the valve driving actuator according to any one of the first to fourth aspects, when an abnormal load is detected,
Since the drive motor is stopped, burnout of the drive motor can be prevented, and the occurrence of an abnormal load is notified to the outside, so that the user can respond quickly.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention. The valve driving actuator according to one embodiment of the present invention is embodied as, for example, a configuration shown in FIG. 4 provided with a mechanism for detecting an abnormal load. FIG. 1 is a diagram showing a main configuration of a valve driving actuator according to an embodiment of the present invention. In FIG. 1, components common to those in FIG. 4 are denoted by the same reference numerals. As shown in FIGS. 1 and 4, the valve driving actuator A1 according to one embodiment of the present invention is displaced in the axial direction within a range of elastic deformation of the disc spring 20 provided with the worm 6b and arranged in the axial direction. A worm shaft 5 rotatably provided around the shaft center, a motor (corresponding to a drive motor) 1 for rotating the worm shaft 5, and a worm wheel 6a fitted with the worm 6b. Output shaft 7 and the worm shaft 5
And a gear connected to the rotating member 21 for amplifying the amount of rotation of the rotating member 21 (a gear of the reduction member). Example) 22, a detection shaft 23 connected to the gear 22, and a cam 24 attached to the detection shaft 23
And a torque switch 25 that contacts when the cam 24 rotates a predetermined amount. The abnormal load detecting means in the valve driving actuator A1 includes the rotating member 21, gear 22, detection shaft 23, cam 24, and torque switch 25.

Hereinafter, the details of the valve driving actuator A1 will be described. Actuator A for valve drive
1, the worm shaft 5 and the output shaft 7 are connected to the chamber 1
01. Further, the speed reduction member 22, the detection shaft 23, the cam 24, and the torque switch 25 are connected to the other chamber 102.
Housed within. The rotating member 21 is provided to penetrate a partition 103 between the chamber 101 and the chamber 102. However, since electrical members such as the torque switch 205 are also arranged in the chamber 102, the bearing of the rotating member 21 is sealed so that oil does not enter from the chamber 101. A large diameter portion 211 is provided at an end of the rotating member 21 on the chamber 101 side. The large diameter portion 21
A projection 212 is provided on the end face of the projection 1.
12 engages with the large diameter portion 501 of the worm shaft 5. A disc spring 20 is arranged in the axial direction of the worm shaft 5, and the worm shaft 5 can be displaced in the axial direction within a range of elastic deformation of the disc spring 20. On the other hand, an end 213 of the rotating member 21 on the chamber 102 side is attached to the chamber 10.
A telescopic spring 214 is mounted between the spring stat 1021 fixed to the second side, and the rotating member 21 is constantly urged in the direction of arrow X by the telescopic spring 214.
As long as the rotation member 21 does not rotate in the direction opposite to the arrow X direction against the bias of the expansion spring 214, the engagement between the protrusion 212 of the rotation member 21 and the large diameter portion 501 of the worm shaft 5 is performed. The matching state is maintained. A gear 22a (22) is provided on a portion of the rotating member 21 on the chamber 201 side.
Is attached using a set screw 221. Gear 2 above
2a is fitted with the gear 22b (22). Gear 22
b is attached to the detection shaft 23 by a set screw 222. A cam 24 is attached to the detection shaft 23 by a set screw 231. A protrusion 241 is formed in the circumferential direction of the cam 24. When the cam 24 rotates a predetermined amount, the lever 205 of the torque switch 205 is rotated.
Contact 1

The above-described valve driving actuator A1
At this time, when the motor 1 is rotating, for example, when the worm shaft 5 is rotating clockwise, the output shaft 7
Is restricted, a thrust force acts on the worm shaft 5 by the torque from the motor 1. When the thrust force acts, the worm shaft 5 moves in the axial direction (the direction of the arrow Y) against the bias of the disc spring 20. When the worm shaft 5 moves in the arrow Y direction, the large-diameter portion 501 of the worm shaft 5 also moves in the arrow Y direction.
The rotating member 21 having the protrusion 212 engaged with the large diameter portion 501 rotates. Thus, the worm shaft 5
Is converted into the amount of rotation of the rotating member 21. When the rotating member 21 rotates, the gear 22a attached to the rotating member 21 with a set screw 221 also rotates. The gear 22a is fitted with the gear 22b, and the rotation amount of the rotating member 21 is amplified. The rotation of the gear 22b is transmitted to the detection shaft 23, and the cam 24 attached to the detection shaft 23 is rotated in the arrow Z direction. When the cam 24 rotates by a predetermined amount, the protrusion 241 of the cam 24 comes into contact with the lever 2051 of the torque switch 205, and it is detected that an abnormal load is applied. The predetermined amount is arbitrarily set by the user according to the diameter of a valve to which the valve driving actuator is mounted. When the lever 205 of the torque switch 205 is operated by the cam 24, the electric output of the torque switch 205 is switched. This electric output is connected to the rotating circuit of the motor 1 so that the motor 1 is stopped and the winding of the motor 1 is prevented from burning. Further, by supplying the electric output to the external contact, it is possible to notify the user that the output shaft 7 is restrained by using an external device connected to the external contact, so that the user can quickly operate. Can be dealt with. Thus, according to the valve driving actuator A1,
Since the abnormal load is detected by amplifying the amount of movement of the worm shaft with a simple configuration, it is possible to provide a small-sized valve driving actuator that is easily set for detecting the abnormal load.

Next, a valve driving actuator according to another embodiment of the present invention will be described with reference to FIG. Here, FIG. 2 is a diagram showing a main configuration of a valve driving actuator A2 according to another embodiment of the present invention.
In FIG. 2, the same components as those in FIGS. 1 and 4 are denoted by the same reference numerals. As shown in FIGS. 2 and 4, a valve driving actuator A2 according to another embodiment of the present invention includes a worm 6b and a disc spring 20 disposed in the axial direction. A worm shaft 5 provided so as to be displaceable and rotatable about an axis, a motor 1 for driving the worm shaft 5 to rotate, and an output shaft 7 connected to a worm wheel 6a fitted with the worm 6b; It is the same as the above-described valve driving actuator A1 in that it has The valve driving actuator A2
Is different from the valve driving actuator A1 in that a magnetic member 3 having magnetism attached to the worm shaft 5 is used.
1 and a signal generator 33 attached to a guide groove 32 provided along the axial direction of the worm shaft 5 and generating a signal when facing the magnetic member 31. The abnormal load detecting means in the valve driving actuator A2 includes the magnetic member 31 and the signal generator 33.

In the valve driving actuator A2, the worm shaft 5 and the output shaft 7 are housed in the chamber 101 'similarly to the valve driving actuator A1. The magnetic member 31 is attached to the worm shaft 5 using a nut 311. A permanent magnet may be used for the magnetic member 31. The signal generator 33
Is housed in a chamber 102 'separated from the chamber 101' by a partition 103 '. Partition wall 10 of chamber 102 '
A mounting base 331 for mounting the signal generator 33 is detachably fixed to 3 '. The mounting table 33
1 shows the worm shaft 5 along the axis of the worm shaft 5 as shown in FIG.
As shown in (c), a guide groove 32 having a substantially C-shaped cross section is formed. In the example of FIG. 2, two guide grooves 33 are formed on the mounting base 331. The above signal generator 33
Has a cross section capable of slidingly contacting the guide groove 32. If the signal generator 33 is inserted into the guide groove 32 from the end of the guide groove 32, the position of the signal generator 33 can be easily adjusted along the axis of the worm shaft 5. it can. When the magnetic member 31 attached to the worm shaft 5 moves to a position facing the signal generator 33, the signal generator 33 generates a signal induced by a magnetic force. For example, a reed switch can be used. Since the magnetic coupling between the magnetic member 31 and the signal generator 33 is performed without any contact, the configuration is simplified.
Further, a partition 103 'completely separates the chamber 101' side (corresponding to a deceleration section) where oil is required from the chamber 102 'side (corresponding to a detecting section) in which electric members are accommodated. Can be. This facilitates maintenance of both the chamber 101 'and the chamber 102'. The position of the signal generator 33 is fixed, for example, by the signal generator 33.
This is performed by a set screw 332 fitted near the tip of the. The position where the signal generator 33 is fixed can be freely set by the user within the range of the guide groove 32.
The signal generator 33 is connected to the motor 1 via a connection line 333.
Is connected to the rotary circuit.

The above-described valve driving actuator A2
At this time, when the motor 1 is rotating, for example, when the worm shaft 5 is rotating clockwise, the output shaft 7
Is restrained, a thrust force acts on the worm shaft 5 by the torque from the motor 1. When the thrust force acts, the worm shaft 5 moves in the axial direction (the direction of the arrow Y) against the bias of the disc spring 20. The operation so far is the same as that of the valve driving actuator A1. When the magnetic member 31 reaches a position facing one of the signal generators 33 with the movement of the worm shaft 5 in the direction of the arrow Y, the motor 1 is connected to the motor 1 via the connection line 333 from the signal generator 33. Is output to the rotation circuit of. Therefore, if the position of the signal generator 33 in the guide groove 32 is adjusted, an abnormal load can be detected. When an abnormal load is detected, the motor 1 may be stopped, notified to the outside, or both may be performed simultaneously, similarly to the valve driving actuator. As described above, according to the valve driving actuator A2, since the abnormal load is detected by a simple configuration using only a very small magnetic member and a signal generator, the size can be reduced. The setting can be easily changed only by moving the signal generator along the guide groove. In addition, in the valve driving actuator A2, the deceleration unit and the detection unit can be completely separated from each other, so that the configuration is simplified in that sense, and maintenance of both the deceleration unit and the detection unit can be easily performed. .

The valve driving actuators A1, A
In No. 2, only the abnormal load was detected. However, in addition to the above-described abnormal load, detection is also performed at a predetermined torque.
That is, the detection may be performed in a plurality of stages. In this case, prepare multiple torque switches and signal generators,
What is necessary is just to provide in the position corresponding to it. For example, assuming that a switch that detects fully closed at the time of normal opening / closing fails, each switch and the motor when a switch is provided corresponding to two operations of operating at constant torque at normal opening / closing and operating at abnormal torque. FIG. 3 shows a connection circuit with the rotation circuit of FIG. In FIG. 3, the motor 1 and the power supply 40 are connected using terminals S2, S3, and S4. When the motor 1 and the power supply 40 are connected using the terminals S2 and S3, the motor 1 operates in the opening direction and the motor 1
When the motor 1 and the power supply 40 are connected using the terminals S2 and S4, the motor 1 operates in the closing direction. The OTLS in FIG. 3 is a switch that operates when an abnormal load occurs.
S is a switch that operates at a constant torque during normal opening and closing, SLS is a switch that operates at the fully closed position during normal opening and closing, and OLS is a switch that operates at the fully open position during normal opening and closing. Of the above four switches, switch SL
S and OLS correspond to the limit switch 11 in FIG. 4, and the switches OTLS and TLS correspond to the abnormal load detecting means in the present invention. In such a circuit configuration, the switch S
If the LS fails or the setting is not completely closed, the rotation of the valve is continued until the switch TLS detects that a certain shutoff torque has been reached.
Further, when the torque switch TSL fails, the switch OLS is activated and the rotation of the valve is stopped even if the operation continues until the switch SLS is turned off and the rotation continues further. As described above, by performing two-stage detection of a constant shut-off torque and an abnormal load in the valve closing direction, it is possible to increase the guarantee of the valve closing position.

[0014]

As described above, according to the valve driving actuator of the first aspect, the abnormal load is detected by amplifying the movement amount of the worm shaft with a simple configuration. It is possible to provide a small-sized valve driving actuator that can easily be set. Further, according to the valve driving actuator according to the second or third aspect, the abnormal load is detected by a simple configuration using only a very small magnetic member and a signal generator, so that downsizing can be achieved. The setting can be easily changed by simply moving the signal generator along the guide groove. Further, according to the valve driving actuator according to the third aspect, the deceleration unit and the detection unit can be completely separated from each other.
Maintenance of both the deceleration unit and the detection unit can be easily performed. Further, according to the valve driving actuator according to the fourth aspect, the valve driving actuator according to any one of the first to third aspects can enhance the guarantee of the valve closing position. Further, according to the valve driving actuator of the fifth aspect, the first aspect of the present invention provides the valve driving actuator.
In the valve driving actuator according to any one of the above-mentioned items, when an abnormal load is detected, the drive motor is stopped, so that the drive motor can be prevented from being burned out. , The user can respond quickly.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of a valve driving actuator A1 according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main configuration of a valve driving actuator A2 according to another embodiment of the present invention.

FIG. 3 is an electric circuit diagram for explaining an example in which two-stage torque detection is performed in a valve closing direction in a valve driving actuator.

FIG. 4 is a diagram showing a schematic configuration example of a valve driving actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motor 5 ... Worm shaft 6a ... Worm wheel 6b ... Worm 7 ... Output shaft 20 ... Disc spring 21 ... Rotating member 22 ... Gear 23 ... Detection shaft 24 ... Cam 31 ... Magnetic member 32 ... Guide groove 33 ... Signal generator 101 , 101 ', 102, 102' ... chamber 103, 103 '... partition wall 205 ... torque switch

Claims (5)

[Claims] 1. A worm shaft provided with a worm and displaceable in the axial direction within a range of elastic deformation of a disc spring arranged in the axial direction and rotatable around the axial center, and rotationally driving the worm shaft. A worm shaft, an output shaft connected to a worm wheel fitted with the worm, and the worm shaft when the worm shaft moves in the axial direction against the bias of the disc spring. An abnormal load detecting means for detecting an abnormal load applied to the output shaft based on the amount of movement of the worm shaft in the axial direction, wherein the abnormal load detecting means engages with the worm shaft. A rotating member that rotates in accordance with the amount of movement of the worm shaft in the axial direction, a speed reducing member connected to the rotating member to amplify the amount of rotation of the rotating member, and a detection shaft connected to the speed reducing member. Equip A valve drive actuator for detecting an abnormal load applied to the output shaft based on a rotation amount of the detection shaft. 2. A worm shaft provided with a worm and capable of being displaced in the axial direction and rotatable about the axial center within a range of elastic deformation of a disc spring disposed in the axial direction and rotating the worm shaft. A worm shaft, an output shaft connected to a worm wheel fitted with the worm, and the worm shaft when the worm shaft moves in the axial direction against the bias of the disc spring. An abnormal load detecting means for detecting an abnormal load applied to the output shaft based on the amount of movement of the worm shaft in the axial direction, wherein the abnormal load detecting means is attached to the worm shaft. A magnetic member having magnetism and a guide groove provided along the axial direction of the worm shaft;
A signal generator for generating a signal when facing the magnetic member, wherein an abnormal load applied to the output shaft is detected based on a signal output from the signal generator. Actuator for valve drive. 3. A deceleration unit in which the worm shaft is arranged,
3. The valve driving actuator according to claim 2, wherein the detection unit in which the signal generator is arranged is separated by a partition. 4. The valve driving actuator according to claim 1, wherein the abnormal load detecting means detects a predetermined valve shut-off torque in addition to detecting the abnormal load. 5. The apparatus according to claim 1, wherein when the abnormal load detecting means detects an abnormal load applied to the output shaft, the drive motor is stopped and a signal indicating occurrence of the abnormal load is output to the outside. 9. The valve driving actuator according to claim 1.