JP3645225B2 - Valve drive actuator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric actuator for driving a valve such as a butterfly valve or a ball valve, and more particularly to an actuator provided with opening degree holding means for holding the valve opening degree of the valve while being fully opened or fully closed.
[0002]
[Prior art]
When a rotary valve for opening and closing a pipe line connected by rotating a valve body (valve) 90 degrees (quarter turn), such as a butterfly valve and a ball valve, is electrically driven, an electric actuator is widely used. Used.
The above-mentioned general electric actuator rotates about an axis within a range of approximately 90 degrees, and is connected via an output shaft that opens and closes a connected valve and a reduction mechanism configured by combining a plurality of spur gears and the like. And an electric motor that rotationally drives the output shaft.
As a result, the electric actuator can control the rotation angle of the output shaft by arbitrarily controlling the electric motor, and thus can arbitrarily control the opening and closing of the valve connected to the output shaft. .
Furthermore, by providing the speed reduction mechanism, the rotational driving force of the electric motor can be more efficiently transmitted to the output shaft, and effects such as miniaturization of the electric motor and suppression of power consumption can be achieved.
[0003]
[Problems to be solved by the invention]
However, in the above-described conventionally known electric actuator, when a drive voltage is not applied to the electric motor, when a fluid pressure fluctuation in the pipe line or some other action acts on the valve connected to the output shaft. As a result, the output shaft is rotated, and the valve opening of the valve cannot be kept fully open or fully closed.
Therefore, the conventionally known electric actuator includes an opening holding means for holding the valve opening of the valve connected to the output shaft fully open or fully closed even when there is no driving torque of the motor. What has been developed.
For example, an electromagnetic brake that restricts the rotation of the output shaft is provided, or a worm gear is provided as the speed reduction mechanism, and self-locking of the worm gear is used. Here, the self-locking is a structural feature of the worm gear. If the worm advance angle of the worm gear is set to a predetermined angle or less, the worm (input shaft) is input from the worm wheel (output shaft) side. The rotation of the side can be prevented.
In the above-described conventionally known electric actuator, such a mechanism is newly added to prevent unnecessary rotation of the output shaft even when a drive voltage is not applied to the electric motor, and the valve opening degree of the valve. Can be held fully open or fully closed.
However, in the former case, it is unavoidable that the control circuit is complicated by adding the electromagnetic brake, or that the size of the apparatus is increased and the manufacturing cost is increased. In addition, the electromagnetic brake generates a braking force by pressing a brake surface having a high frictional force against the output shaft. Therefore, in order to obtain an appropriate braking force, an operator having a special skill is required. Regular maintenance work is required. For example, if the maintenance work is neglected and the braking force is set excessively, the actuator driving torque will be insufficient, and if the electromagnetic brake is not released even after the driving voltage is applied to the motor, There is a risk of overheating or burning of the motor. In order to avoid such a situation, regular maintenance work is indispensable, and an increase in maintenance costs due to the maintenance work cannot be avoided.
In the latter case, there is a problem that the output efficiency of the worm gear is lowered (generally reduced to about 30 to 40%) due to the worm lead angle of the worm gear being set to a predetermined angle or less. In other words, in order to obtain a predetermined driving torque necessary for opening and closing the valve, a larger driving torque is used to compensate for the loss in the worm gear than in the case of using a reduction gear composed only of a spur gear. An electric motor that can be generated is required. As a result, an increase in manufacturing cost or power consumption and an increase in size of the apparatus cannot be avoided.
Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to open the valve so that the valve opening degree of the valve is maintained at a predetermined opening degree when no driving voltage is applied to the electric motor. An object of the present invention is to provide a valve driving actuator provided with an opening degree holding means which does not increase the cost or increase the size of the apparatus.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention comprises an output shaft that rotates in both directions around an axis within a range of approximately 90 degrees, opens and closes a connected valve, an electric motor that rotationally drives the output shaft in both directions , Even when there is no driving torque of the motor, the opening holding means for holding the valve opening of the valve connected to the output shaft in a fully open state or a fully closed state, and the valve opening degree in a fully open or fully closed state. A full open / close detection means for detecting each of the certain things, and the supply of drive power to the electric motor is cut off when the full open / close detection means detects that the valve opening is fully open or fully closed. and control means, a valve driving actuator comprising comprises a, the opening degree maintenance means is formed at an arbitrary position on the circumferential surface of the output shaft, the first engagement which rotates together with the output shaft And the part A second engaging portion provided immovably with respect to the output shaft, and the first engaging portion and the second engaging portion; When the valve opening of the valve is fully open, the first engaging portion is urged in the direction to open the valve, and when the valve opening of the valve is fully closed, the valve is closed. And an elastic member that urges the first engaging portion in a direction to be configured as a valve driving actuator.
With this configuration, the valve opening degree of the valve is held at a predetermined opening degree by the elastic force of the elastic member connected to the output shaft. Opening holding means can be realized, and compared to the case of newly adding an electromagnetic brake or worm gear, it is possible to avoid an increase in manufacturing cost and an increase in the size of the device, and no routine maintenance work is required. It becomes.
Furthermore, by eliminating the need for a worm gear, it is possible to avoid a reduction in transmission efficiency, which is an inevitable problem when a worm gear is added, and the capacity of the motor can be reduced compared to the case where a worm gear is added. Therefore, it can contribute to downsizing of the device and suppression of power consumption.
[0005]
Here, at a predetermined position within the rotation range of the first engaging portion, the elastic member that connects the first engaging portion and the second engaging portion exceeds the dead point. The second engagement portion may be provided.
As a result, the direction in which the elastic member urges the output shaft can be switched with the dead point as a boundary. That is, when the valve opening degree of the valve is fully opened by the elastic force of the elastic member, the first engagement portion is urged in the direction to open the valve, and the valve opening degree of the valve is reduced. When the valve is fully closed, the first engaging portion can be biased in the direction in which the valve is closed.
For example, as the position where the second engagement portion is provided, a predetermined position in the rotation range of the first engagement portion where the elastic member exceeds the dead point is a substantially central position in the rotation range. It is possible.
As a result, the urging force that urges the output shaft in the direction in which the valve opening degree of the valve is opened and the urging force that urges the output shaft in the direction in which the valve opening degree of the valve is closed are equal in the opposite direction. The valve opening degree can be maintained by a predetermined urging force regardless of whether the valve is fully opened or fully closed.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments and examples of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiments and examples are examples embodying the present invention, and are not of a nature that limits the technical scope of the present invention.
FIG. 1 is a diagram showing a schematic configuration of a valve drive actuator A according to an embodiment of the present invention, FIG. 2 is a plan view of the valve drive actuator A when the valve is fully closed, and FIG. FIG. 6 is a plan view of the valve drive actuator A when is fully open.
[0007]
As shown in FIG. 1, an actuator A for driving a valve according to an embodiment of the present invention rotates around an axis Z in a range of approximately 90 degrees and opens and closes a valve (not shown) to be connected. 6, a motor (provided as an example of an electric motor) 1 that applies a driving torque for rotating the output shaft 6 and includes a reduction gear head 2, and a motor gear 3 provided on a motor shaft 4 that is an output end of the motor 1. A spur gear 5 provided on the output shaft 6 so as to mesh with the motor gear 3, a dock 9a, 9b provided at a predetermined position of the output shaft 6 and rotating together with the output shaft, and the dock 9a, 9b. Limit switches 10a and 10b that are operated according to the rotational positions of the docks 9a and 9b and detect whether the valve is fully open or closed, and the output shaft 6 is connected to the radial direction of the output shaft 6 Formed into A holding pin (corresponding to an example of a first engaging portion) 12 provided near the end of the arm 11 and rotating together with the output shaft 6 and immovable with respect to the output shaft 6 on the side of the holding pin 12 And a biasing spring (corresponding to an example of an elastic member) 14 for connecting the holding pin 12 and the spring supporting stud 13 to each other. It is roughly composed. The opening degree holding means in the valve driving actuator A includes the holding pin 12, the spring support stat 13, and the biasing spring 14.
[0008]
Next, details of the operation of the valve driving actuator A will be described.
First, the driving torque of the motor 1 that is arbitrarily controlled by an external command is decelerated by the reduction gear head 2, and then the motor gear 3 provided on the motor shaft 4 is rotated. Next, the driving torque of the motor gear 3 is transmitted to a spur gear 5 provided so as to mesh with the motor gear 3, and the output shaft 6 provided with the spur gear 5 is provided so as to be rotatable around the axis Z. Rotate.
As a result, by controlling the rotation (drive torque) of the motor 1, the rotation angle of the valve connected to the output shaft 6 can be controlled, and the pipe line to which the valve is connected can be arbitrarily set. Can be opened and closed.
Here, if the output shaft 6 is rotated and rotated to a position corresponding to the fully open (fully closed) valve opening, a dock 9a (9b) provided on the output shaft 6 and rotating together with the output shaft 6 is provided. However, the limit switch 10a (10b) corresponding to full open (fully closed) is operated, and it is detected that the valve opening has been fully opened (fully closed). The dock 9a (9b) and the limit switch 10a (10b) are an example of a full open / close detection means.
Here, if each contact of the limit switch 10a or 10b is used as an input signal to a control circuit (an example of control means) ( not shown) for driving the motor 1, the valve opening degree is fully opened or fully closed. It is possible to configure a circuit that cuts off the drive voltage to the motor 1 on the condition that it has become such that it is possible to prevent an unnecessary voltage from being applied to the motor 1 and to reduce power consumption, or It is possible to prevent overload or overheating of the motor 1 in advance.
The operation or control method of the valve driving actuator of the rotary valve using the electric motor as described above is conventionally known.
[0009]
The valve drive actuator A according to the embodiment of the present invention further includes the holding pin 12, the spring support stat 13, and the biasing spring 14 as an example of the opening degree holding means. Let it be a point.
The details of the operation of each part of the rotation holding means will be described with reference to FIG.
(Fully closed)
First, consider the operation of fully closing the valve opening by the opening holding means. Here, FIG. 2 is a plan view of the valve driving actuator A that holds the valve opening degree in a fully closed state, and FIG. 2 shows a cross-section of the valve driving actuator A shown in FIG. I will explain.
Here, the holding pin 12 is provided in the vicinity of the end portion of the arm 11 formed in the radial direction of the output shaft 6 at an arbitrary position on the peripheral surface of the output shaft 6, and rotates together with the output shaft 6. Is possible.
The spring support stat 13 is provided on the side of the holding pin 12 and does not move with respect to the output shaft 6.
Therefore, the output shaft 6 closes the valve by connecting the holding pin 12 and the spring support stat 13 with the biasing spring 14 that generates a biasing force F1 (indicated by an arrow in the figure). Energized by an energizing torque Fc (indicated by an arrow in the figure) in the direction of
Thus, even when there is no voltage applied to the motor 1, the opening degree of the valve connected to the output shaft 6 can be kept fully closed by the biasing torque Fc.
(Fully open)
Next, consider the operation of keeping the valve opening fully open by the opening holding means.
Here, FIG. 3 is a plan view of the valve driving actuator A that keeps the valve opening degree fully opened, and FIG. 3 shows a cross-section of the valve driving actuator A shown in FIG. explain.
Here, FIG. 3 shows a state where the output shaft 6 is rotated approximately 90 degrees counterclockwise from the valve driving actuator A which was in the state of FIG.
That is, as in the case of the fully closed holding described above, the output shaft 6 is biased in the valve opening direction by the action of the biasing spring 14 that generates the biasing force F2 (indicated by an arrow in the drawing). Energized by energizing torque (indicated by arrow Fo in the figure).
Accordingly, even when there is no voltage applied to the motor 1, the opening degree of the valve connected to the output shaft 6 can be kept fully open by the biasing torque Fo.
Here, the position where the spring support stat 13 is provided is that when the holding pin 12 is rotated to a predetermined position (indicated by D in the drawing) on the arc B indicating the rotation trajectory of the holding pin 12. What is necessary is just to set it as the position which exceeds the dead point of the elastic member 14. FIG.
As a result, the direction in which the output shaft 6 is urged by the elastic member 14 can be switched with the dead point D as a boundary, and the output shaft 6 has a biasing torque when the valve is fully open. When the valve is biased in the direction of Fo and the valve is fully closed, the valve is biased in the direction of the biasing torque Fc, and the valve connected to the output shaft 6 is held fully open or fully closed. obtain.
In the valve driving actuator A, the position D at which the biasing spring 14 exceeds the dead point is set to a substantially central position on the arc B indicating the rotation locus of the holding pin 12.
As a result, the urging torques Fc and Fo generated by the urging force of the urging spring 14 can be made in the opposite directions and in the same amount, and a predetermined (same) urging can be performed regardless of whether the valve is fully open or fully closed. The valve opening degree can be maintained by the force torque (Fo = Fc).
On the other hand, if the urging torque required to hold the valve fully open is different from the urging torque required to hold the valve fully closed, the output shaft 6 is connected to the valve fully open. It is necessary to urge with different urging torques depending on the full closure.
In that case, the position where the spring support stat 13 is provided is changed, and the biasing torque Fo that biases the valve in the opening direction by arbitrarily adjusting the position D where the biasing spring 14 exceeds the dead point. And the biasing torque Fc that biases the valve in the closing direction can be adjusted arbitrarily, and the valve opening is maintained by a suitable biasing torque (Fo ≠ Fc) for each full opening and closing of the valve. can do.
The biasing torque required to keep the valve opening fully closed (fully open) is the drive torque required to open (close) the valve from the fully closed (fully open) state during normal use. Is known to be too small.
Therefore, in the valve driving actuator A, even when the valve opening degree is kept fully closed (fully opened) by the biasing torque Fc (Fo), the valve opening operation (closing operation) during normal use is performed. Will not be disturbed.
Here, as a method of adjusting the urging torque Fc (Fo), the urging force F1 (F2) of the urging spring 14 is changed, or the distance between the holding pin 12 and the spring support stat 13 is changed. It is possible to implement arbitrarily and easily by adjusting.
[0010]
【Example】
In the valve drive actuator A according to the embodiment of the present invention described above, the case where the biasing force generated by the biasing spring 14 is an attractive force is described.
However, the urging force generated by the urging spring 14 is not limited to attractive force, and may be a valve driving actuator having an elastic member 14 ′ that generates repulsive force.
In that case, it is understood that the same effect as that of the valve driving actuator A can be obtained by providing the spring support stat 13 at a position symmetrical with respect to the straight line X shown in FIG. Easy to.
[0011]
【The invention's effect】
As described above, the present invention includes an output shaft that rotates in both directions around an axis within a range of approximately 90 degrees, opens and closes a connected valve, an electric motor that rotationally drives the output shaft in both directions, Even when there is no driving torque of the electric motor, the opening holding means for holding the valve opening of the valve connected to the output shaft in a fully open or fully closed state, and the valve opening is in a fully open or fully closed state. Full open / close detection means for detecting each of the above, and control for cutting off the supply of drive power to the motor when the full open / close detection means detects that the valve opening is fully open or fully closed a valve driving actuator formed by and means, and the opening degree maintenance means is formed at an arbitrary position on the circumferential surface of the output shaft, a first engagement portion that rotates together with the output shaft And the first A second engaging portion provided immovably with respect to the output shaft, and the first engaging portion and the second engaging portion are connected to the side of the joint portion, and the valve of the valve When the opening is fully open, the first engaging portion is urged in the direction to open the valve, and when the valve opening of the valve is fully closed, the valve is closed. And an elastic member that biases the first engaging portion.
With this configuration, the valve opening degree of the valve is held at a predetermined opening degree by the elastic force of the elastic member connected to the output shaft. Opening holding means can be realized, and compared to the case of newly adding an electromagnetic brake or worm gear, it is possible to avoid an increase in manufacturing cost and an increase in the size of the device, and no routine maintenance work is required. It becomes.
Furthermore, by eliminating the need for a worm gear, it is possible to avoid a reduction in transmission efficiency, which is an inevitable problem when a worm gear is added, and the capacity of the motor can be reduced compared to the case where a worm gear is added. Therefore, it can contribute to downsizing of the device and suppression of power consumption.
[0012]
Here, at a predetermined position within the rotation range of the first engaging portion, the elastic member that connects the first engaging portion and the second engaging portion exceeds the dead point. The second engagement portion may be provided.
As a result, the direction in which the elastic member urges the output shaft can be switched with the dead point as a boundary. That is, when the valve opening degree of the valve is fully opened by the elastic force of the elastic member, the first engagement portion is urged in the direction to open the valve, and the valve opening degree of the valve is reduced. When the valve is fully closed, the first engaging portion can be biased in the direction in which the valve is closed.
For example, as the position where the second engagement portion is provided, a predetermined position in the rotation range of the first engagement portion where the elastic member exceeds the dead point is a substantially central position in the rotation range. It is possible.
As a result, the urging force that urges the output shaft in the direction in which the valve opening degree of the valve is opened and the urging force that urges the output shaft in the direction in which the valve opening degree of the valve is closed are equal in the opposite direction. The valve opening degree can be maintained by a predetermined urging force regardless of whether the valve is fully opened or fully closed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a valve driving actuator A according to an embodiment of the present invention.
FIG. 2 is a plan view of the valve drive actuator A when the valve is fully closed.
FIG. 3 is a plan view of the valve drive actuator A when the valve is fully open.
[Explanation of symbols]
A ... Valve driving actuator 1 ... Motor 2 ... Reduction gear head 3 ... Motor gear 4 ... Motor shaft 5 ... Spur gear 6 ... Output shaft 9a, b ... Dock 10a, b ... Limit switch 11 ... Arm 12 ... Holding pin 13 ... Spring Support stat 14 ... biasing spring

Claims (2)

Even when there is no output torque that rotates in both directions around the axis in the range of approximately 90 degrees, opens and closes the connected valve, and rotates the output shaft in both directions, and there is no driving torque of the motor, Opening holding means for holding the valve opening of the valve connected to the output shaft in a fully open or fully closed state, and a fully open / closed detection for detecting whether the valve opening is in a fully open or fully closed state. And a control means for cutting off the supply of drive power to the motor when the fully open / closed detecting means detects that the valve opening is fully open or fully closed. a use actuator,
A first engaging portion that is formed at an arbitrary position on the peripheral surface of the output shaft and rotates together with the output shaft;
A second engagement portion provided immovably with respect to the output shaft on a side of the first engagement portion;
The first engagement portion is connected to the second engagement portion, and when the valve opening degree of the valve is fully open, the first engagement portion is moved in the direction to open the valve. And when the valve opening of the valve is fully closed, an elastic member configured to urge the first engagement portion in a direction to close the valve;
An actuator for driving a valve, comprising: The elastic member that connects the first engaging portion and the second engaging portion at a substantially central position within the rotation range of the first engaging portion so as to exceed the dead point. The valve driving actuator according to claim 1, wherein two engaging portions are provided .

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