The present invention relates to a valve device.
In the field of valve devices as well, an electronic device such as a pressure sensor or a wireless module is mounted to increase the functionality of the device (refer to Patent Documents 1, 2, and 3). As means for supplying electric power used in these electronic devices, a method for driving various sensors using a button battery is disclosed in Patent Document 2. Further, in Patent Document 3, a system is disclosed in which a controller transmits to an electromagnetic valve a high frequency waves superimposed on a control input signal, and the valve extracts the high frequency component from the input control signal to receive a power.
Patent Document 1: JP 2011-513832 A
Patent Document 2: JP 2016-513228 A
Patent Document 3: JP 2017-020530 A
Even with an air-driven type valve device using air pressure, that is used in a semiconductor manufacturing system, there is a demand to have a power source for operating the various electronic devices.
As one means, it is conceivable to introduce a wiring for a power source from the outside to the valve device. However, in a fluid control system in which a large number of valves are installed, the wiring is not only complicated but, requires careful design and arrangement of the wiring to attend explosion-proof problems.
Further, as one means, a battery is used as a power source to solve problems involving wiring. However, this requires a primary battery with a capacity sufficient to meet the service life of the valve device, or the task of regular battery replacement.
The high-frequency superimposed power transmission to the electromagnetic valve in Patent Document 3 cannot be applied to a valve device that is an air-driven type.
A valve device used in a semiconductor manufacturing system is, for example, installed near a vibration source such as a vacuum pump, for example. Thus, while the semiconductor manufacturing system is in operation, the valve device is constantly subjected to external environmental vibrations. When the valve device is subjected to environmental vibrations, the valve element is also subjected to vibrations, which may affect the flow rate. In order to enable more precise flow rate control, the influence of environmental vibrations cannot be ignored.
An object of the present invention is to provide a valve device that can mount various electronic devices, includes a power generation function to solve problems involving wiring or battery replacement, and can suppress the influence of environmental vibrations.
A valve device according to the present invention comprises an actuator including a housing part, and a movable part housed in the housing part and driven by a driving fluid to move a valve element in a closing direction or an opening direction, a spring member that presses the movable part in a direction against a driving force of the driving fluid, and a power-generating and vibration-damping unit that uses a piezoelectric effect of a piezoelectric element to exercise a power generation function of converting a vibration generated in a vibration system by an activation of the actuator into electric power, and a vibration-damping function of suppressing a vibration applied to a device.
Preferably, a configuration can be adopted in which the valve device further includes an adjusting circuit formed so that dynamic characteristics of the vibration system can be controlled in accordance with a vibration applied from the outside of the device.
According to the present invention, a power-generating and vibration-damping unit can generate electricity by converting a vibration of a vibration system into electric power, making it possible to obtain a valve device that solves problems involving wiring or battery replacement. In addition, the power-generating and vibration-damping unit can suppress vibrations such as environmental vibrations applied from the outside of the valve device by the vibration-damping function.
Embodiments of the present invention are described below with reference to the drawings. It should be noted that, in this specification and the drawings, components having substantially the same function are denoted using the same reference numeral, and duplicate descriptions thereof are omitted.
A valve device 1 includes an actuator part 7 and a valve body 20. A pipe 5 with a pipe joint 3 connected to one end portion is introduced into an interior of the actuator part 7. Through the pipe 5, a driving fluid is supplied to the interior of the actuator part 7 or an air released from the actuator part 7 is discharged to the outside. As the driving fluid, for example, compressed air is used.
The actuator part 7 includes an actuator cap 10 having a cylindrical shape with an upper end part thereof closed, an actuator case 11 having a cylindrical shape, an actuator body 12, a piston member 13, a diaphragm presser 15, a coil spring 30, and a power-generating and vibration-damping unit 100.
The actuator cap 10 has a lower end part fixed to a spring receiving member 8 formed into an annular shape, and is provided with a circuit housing part 40 in the internal space. In
The actuator case 11 supports the spring receiving member 8 on an upper end side thereof, and is screwed and fixed to the actuator body 12 on a lower end side thereof.
The actuator body 12, as illustrated in
The piston member 13 includes a flow channel 13a communicating to the cylinder chamber 12c in a central portion. The flow channel 13a communicates with a pipeline 5a of a pipe 5. The flange part 13b and a tip end shaft part 13c of the piston member 13 freely moves through the cylinder chamber 12c and the through hole 12b in the upward and downward directions A1, A2 via the O-ring OR. A member 9 having a cylindrical shape is provided to an upper end part of the piston member 13, and restricts the movement of the O-ring OR that seals an area between the member 9 and the pipeline 5a of the pipe 5.
The diaphragm presser 15 is movable in the upward and downward directions A1, A2 by the guide hole 12a of the actuator body 12.
The valve body 20 is screwed with a lower side of the actuator body 12 at an upper side, and defines flow paths 21, 22 of a gas or the like that include openings 21a, 22a on bottom surfaces thereof. The flow paths 21, 22 are connected with other flow path members via a seal member (not illustrated).
A valve seat 16 is provided around the flow path 21 of the valve body 20. The valve seat 16 is formed from a resin such as a perfluoroalkoxyalkane (PFA) or a polytetrafluoroethylene (PTFE) in an elastically deformable manner.
A diaphragm 17 functions as a valve element, has a larger diameter than the valve seat 16, and is formed in an elastically deformable manner into a spherical shell shape of a metal such as stainless steel or an NiCo-based alloy, or a fluorine-based resin. The diaphragm 17 is supported by the valve body 20 so as to allow contact with and separation from the valve seat 16 by being pressed toward the valve body 20 by a lower end surface of the actuator body 12 via a pressing adapter 18. In
The coil spring 30 is provided around a cylindrical portion 8a provided at a center of the spring receiving member 8, is interposed between a spring receiving part 8b of the spring receiving member 8 and the flange part 13b of the piston member 13, and continually presses the piston member 13 in the downward direction A2 by a restoring force. As a result, an upper end surface of the diaphragm presser 15 is pressed in the downward direction A2 by the piston member 13, and the diaphragm 17 is pressed toward the valve seat 16.
The power-generating and vibration-damping unit 100 is fixed to an inner peripheral surface of the actuator case 11 via a support member 110.
Here,
The power-generating and vibration-damping unit 100 includes a piezoelectric bimorph 102 formed into an arc shape so as to fit in a space between an outer periphery of the coil spring 30 and the inner peripheral surface of the actuator case 11, the support member 110 that supports a base end part 102b of the piezoelectric bimorph 102 on the flange part 13b, and a mass part 120 provided at a tip end part 102a of the piezoelectric bimorph 102. The base end part 102b of the piezoelectric bimorph 102 is formed with an attaching hole 102h and is fixed to an upper surface of the support member 110 by a screw member, the tip end part 102a of the piezoelectric bimorph 102 is a free end, and the piezoelectric bimorph 102 constitutes an elastic deformation part having a cantilevered shape.
The piezoelectric bimorph 102 includes a metal plate 104 that is thin and is for maintaining mechanical strength, and piezoelectric elements 103A, 103B that are sheet-like members and provided on a front and a back of the metal plate 104. The piezoelectric elements 103A, 103B are electrically connected to a load circuit 600 described later. When the piezoelectric bimorph 102 is bent, the piezoelectric elements 103A, 103B are compressed or expanded and an electromotive force corresponding to the amount of this deformation is generated. Electric power can be differentially extracted from the piezoelectric elements 103A, 103B by the load circuit 600 described later.
Due to a structure such as one described above, the power-generating and vibration-damping unit 100 forms a vibration system that continues vibration-damping to generate electricity for a while when an impact is applied by a vertical movement of the piston member 13. Specifically, the piston member 13 is raised in the upward direction A1 by the supply of compressed air, which is a driving fluid, and an impact is produced when movement is restricted at a predetermined position. Further, when the compressed air is released, an impact is produced when the diaphragm presser 15 collides with the valve seat 16 via the diaphragm 17 due to the restoring force of the coil spring 30. Furthermore, even when the piston member 13 stops between fully opened and fully closed for use in an intermediate open state, or when the piston member 13 starts to move for opening and closing operations, a small impact is produced. Due to these impacts, vibration is generated in the power-generating and vibration-damping unit 100. Accordingly, in order to absorb the vibration in an operation direction of the piston member 13, a surface of the piezoelectric bimorph 102 is attached so as to be substantially perpendicular to an axis of the piston member 13.
In order to secure the amount of power generation, it is preferable that the area of the power-generating and vibration-damping unit 100 is as large as possible. In this embodiment, the power-generating and vibration-damping unit 100 is formed into an arc shape, and is housed in a space between the outer periphery of the coil spring 30 and the inner peripheral surface of the actuator case 11, enabling an arrangement in which the power-generating and vibration-damping unit 100 increases area while being incorporated into the valve device 1 and deviation of a center of gravity of the piston member 13 is reduced to the extent possible. It should be noted that the shape of the power-generating and vibration-damping unit 100 is not necessarily limited to an arc shape, and may be formed into, for example, an annular shape. The same cantilever structure can be obtained by fixing any point of the annular shape to the support member 110 as one end portion, and providing a mass part 120 on an opposite side of the annulus. Further, a rigidity of the piezoelectric bimorph 102 and a size of the mass part 120 can be set according to a desired natural frequency.
The load circuit 600 includes a rectifier circuit 601, a power supply integrated circuit (IC) 602, a microcontroller 603, various sensors 604 such as a pressure sensor, a temperature sensor, and an acceleration sensor, a wireless part 605 capable of transmitting data detected by the various sensors 604 to the outside, a secondary battery 606, a circuit control part 607, and an adjusting part 608 controlled by this circuit control part 607.
The rectifier circuit 601 converts an alternating current generated in the power-generating and vibration-damping unit 100 into a direct current through the adjusting part 608.
The power supply IC 602 functions as a power management IC that regulates electric power transmitted to a power supply destination such as the microcontroller 603, the various sensors 604, or the wireless part 605, while converting and storing the voltage of the electric power from the power-generating and vibration-damping unit 100 in the secondary battery 606. For example, as the power supply IC 602, a power supply IC commonly available for energy harvesting can be adopted.
The secondary battery 606 stores direct current power supplied from the power supply IC 602. A capacitor having a relatively large capacity can also be used in place of the secondary battery.
The circuit control part 607 outputs a control signal for controlling the adjusting part 608.
The adjusting part 608 selectively switches between the power generation function and the vibration-damping function of the power-generating and vibration-damping unit 100 in accordance with a control signal from the circuit control part 607.
Components other than the various sensors are housed in the circuit housing part 40, and the various sensors are disposed near the flow path or the like of the valve device 1 to detect pressure, temperature, and vibration, and are electrically connected by wiring with the power supply IC 602 and the microcontroller 603.
As described above, the power-generating and vibration-damping unit 100 can differentially extract voltage by generating voltage by the deformation of the piezoelectric elements 103A, 103B. That is, a power generation function is provided.
In addition, when voltage is appropriately applied to the piezoelectric elements 103A, 103B, the power-generating and vibration-damping unit 100 can apply a bending force to the piezoelectric bimorph 102. That is, the piezoelectric elements 103A, 103B are actuators, and apply voltage to the piezoelectric elements 103A, 103B through the adjusting part 608, making it possible to control the vibration of the piezoelectric bimorph 102.
As illustrated in
Further, for example, when an environmental vibration from the outside is applied to the valve device 1, the environmental vibration can be detected by the acceleration sensor of the sensors 604, and the piezoelectric elements 103A, 103B can be subjected to feedback control (active vibration-damping) so as to eliminate the environmental vibration. When the power-generating and vibration-damping unit 100 exhibits the vibration-damping function, a necessary low vibration environment can be formed.
By incorporation of the power-generating and vibration-damping unit 100 having such power-generating and vibration-damping functions into the valve device 1, the functions of the valve device 1 can be enhanced. It should be noted that the timing at which the vibration-damping function is exhibited is arbitrary and not necessarily limited to when an environmental vibration is applied such as described above. It is also possible to activate vibration-damping control during piston activation to significantly alleviate the impact, and generate power using environmental vibrations from the outside and applied when the valve is released. Further, needless to say, as a specific method of vibration-damping control, a known method can be adopted as appropriate. Furthermore, a configuration may be adopted in which only the power generation function or only the vibration-damping function of the power-generating and vibration-damping unit 100 is used.
While a so-called normally closed valve is given as an example in the above-described embodiment, the present invention is not necessarily limited thereto and can be applied to a so-called normally opened valve as well.
While a case where the valve device 1 is driven by compressed air is given as an example in the above-described embodiment, a gas other than air can also be used.
While a diaphragm-type valve is given as an example in the above-described embodiment, the present invention is not necessarily limited thereto and can be applied to other types of valves as well.
While a case where a bimorph-type power-generating and vibration-damping unit is used is described in the above-described embodiment, the present invention is not limited thereto, and a monomorph type can also be adopted. Further, the power-generating and vibration-damping unit can also be configured by combining multilayered-type piezoelectric elements, springs, and masses.
While a case where the piezoelectric bimorph serving as the power-generating and vibration-damping unit is only a single piezoelectric bimorph is given as an example in the above-described embodiment, a configuration can also be adopted in which a plurality of piezoelectric bimorphs are attached to different locations.
Number | Date | Country | Kind |
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2017-129016 | Jun 2017 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2018/022440 | 6/12/2018 | WO | 00 |