JP2003021249A - Fluid control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid control valve capable of surely stopping the flow when a pump is stopped, by utilizing the pressure difference even in the case when the upstream pressure is higher than the downstream pressure, and further in the case the pressure difference is variable, and to surely open the valve when the pump is driven. SOLUTION: A blocking wall having a hole on the way of a channel and a float are mounted as the valve, and a mechanism for closing the valve by the upstream pressure is mounted. The sealability as the valve is improved while efficiently receiving the pressure, and further the float has the conical shape having a small area at its upstream side to obtain the effect to easily open the valve, and a thin film is formed on an outer peripheral part of the bottom face of the cone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the flow of a fluid such as liquid or gas, and particularly when the pressure on the upstream side is positive with respect to the pressure on the downstream side. The present invention relates to a fluid control device that shuts off by using side pressure.

[0002]

2. Description of the Related Art At present, a so-called diaphragm structure in which a part of a silicon wafer is thinned, a driving element such as a piezoelectric element is attached to this diaphragm, and the diaphragm is deformed as a unimorph to form a capacitance in a part of a channel. There has been proposed a flow sending device that sends a fluid by causing a change.

In such a liquid feeding device, a check valve is usually provided in a part of a flow passage as shown in FIG. 6 in order to feed a non-directional change in the shape of a fluid in one direction. Met.
This check valve closes due to the pressure difference when the pressure on the downstream side becomes larger than the pressure on the upstream side and a reverse flow of fluid occurs.

[0004]

However, in the above liquid sending apparatus, since the check valve is a passive valve for preventing backflow, it is always opened when the pressure on the upstream side is higher than the pressure on the downstream side. However, it has a problem that it does not function as a valve. In order to solve this problem, a normally closed valve was devised (Reference Masayoshi Esashi, Shuichi Shoji and Akira Naka).
no, “NORMALLY CLOSEVALVE AND MICROPUMP FABRICATED
ON A SILOCON WAFER ”; Proceedings of the IEEE Mi
cro Electro Mechanical Systems Workshop (MEMS'8
9), pp29-34 (1989)). This valve tries to stop the flow against the pressure on the upstream side by a spring element, but due to the force relationship between the pressure on the upstream side, the drag force of the valve spring, and the pumping force of the pump, Whether it is done or not is decided. That is, when the pressure difference between the upstream side and the downstream side is Pd, the flow force of the pump is Pp, and the spring force of the valve is Pv, the condition for the flow is that the relationship between these three forces is expressed by equation (1). In the state of Expression (2), the flow does not occur and the valve is in the closed state.

Pd + Pp> Pv ·· (1) Pd + Pp <Pv ·· (2) Of these three forces, the operation of the pump, that is, by changing the value of Pp, equations (1) and (2) The basic control method is to intentionally create a state and send the flow. However, unless Pd is provided with a mechanism for applying a certain pressure to a tank or the like, it changes with the flow of the air. If it is too strong, there is a problem that the valve cannot be released due to the force of pumping. There is a method of always operating the actuator of the valve part as a method of surely stopping the flow, but in the case of a compact and portable flow mechanism where low power consumption is an important factor, that mechanism should be used. Not available.

The present invention has been made in order to solve the above problems, and when the pressure on the upstream side is larger than the pressure on the downstream side, and when the pressure difference changes, the pressure difference is also reduced. An object of the present invention is to obtain a fluid control valve that can reliably stop the flow of water when the pump is stopped and can reliably open the valve when the pump is driven.

[0007]

In order to achieve the above-mentioned object, a fluid control valve according to the present invention has a shutoff wall with a hole and a floating element disposed in the middle of a flow passage as a valve, and the pressure on the upstream side is It is equipped with a mechanism to close the valve. Further, in order to improve the airtightness of the valve while efficiently receiving pressure and to make it easier to open the valve, the shape of the floating element is a conical shape with a small upstream area. A thin film is provided on the outer peripheral portion of the bottom surface. Further, in order to prevent the floating element from separating from the valve portion, a stopper larger than the flow path hole is arranged on the downstream side of the blocking wall, and is connected to the floating element by a connecting rod that passes through the flow path hole. In this case, on the blocking wall side of the stopper,
Notches are provided so that the stopper does not interfere with the flow even if it comes into close contact with the blocking wall. As another means for preventing the floating element from separating from the flow path hole, there is also a method of providing a floating stopper for restricting the movement by the contact of the side surface of the cone.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a structure, a manufacturing method and a driving method of a fluid control valve according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to this embodiment.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
FIG. 6 is a perspective view showing a floating element of the fluid control valve according to the embodiment of FIG. 2 is a sectional view of the fluid control valve of the present invention. Further, FIG. 3 is a diagram showing an operating state of the floating element of the present invention.

The floating element 101 comprises a main pillar portion 102, a thin film umbrella portion 2, a connecting rod 105 and a stopper 106. Here, the floating element is the flow path hole 3 formed in the blocking wall 2.
The main pole 102 and the stopper 106 sandwich the blocking wall 2 by means of the connecting rod 105 that is passed through.

The fluid control valve comprises a floating element 101, a diaphragm 4, an actuator 5, a blocking wall 2 and a port 6. When the pressure on the upstream side of the floating element is high,
As shown in (a), the pressure is applied to the floating element to push the main column bottom 103 and the thin film umbrella 104 against the blocking wall, and the valve is closed. In this case, the higher the pressure on the upstream side, the stronger the force for pressing the floating element, and the extremely high back pressure resistance can be achieved. Further, when the actuator is operated to push up the connecting rod 105, FIG.
As shown in (b), the thin film umbrella portion 104 and the main pillar bottom portion 10
3 breaks away from the barrier and the flow path is open, ie
The valve is open. Here, the actuator pushes up the connecting rod and thus the floating element to the upstream side, but since the main column portion of the floating element has a conical shape, the influence of the pressure on the upstream side is alleviated. Also, the thin film umbrella portion 2 has a cantilever structure. When the floating element is pushed up, it bends downward and the influence of the upstream pressure is mitigated. Due to these two effects, the force for the actuator to push the floating element to the upstream side is small.

Next, when the operation of the actuator is stopped,
The floating element is pressed against the blocking wall again by the pressure and the flow on the upstream side, and the valve is closed.

(Embodiment 2) FIG. 3 (a) shows a state in which the floating element is pushed up and the valve is pressed, but the pressure on the upstream side largely drops and the force of the actuator is relatively increased. If it becomes larger, the floating element is further pushed up and the stopper 106 is pressed against the blocking wall, so that the valve may be closed.
Therefore, when the stopper is pressed against the blocking wall,
The stopper 106 is provided with the cutout groove 7 for ensuring the flow passage. FIG. 4 shows a perspective view of the stopper. Here, the shape of the stopper is not limited to this, and may be any shape that can secure the flow path when the stopper is pressed against the blocking wall.

(Third Embodiment) FIG. 5 is a sectional view showing the structure of a fluid control valve according to a third embodiment of the present invention. If the stopper 106 is not attached to the float in consideration of the ease of assembly, the connecting rod 105 of the float may come out of the flow path hole when the valve is opened and closed. Therefore, in order to prevent the float 101 from falling out of the flow path hole 3, the float stopper 8 is provided on the inner wall of the tube on the upstream side of the float. The shape of the stray stop was made by inserting a tube with the same outer diameter as the inner diameter of the port 6 as shown in Fig. 5, but it can also be stopped by packing a filter at a predetermined position inside the port. You can also do it. Further, by using an electromagnet for the floating stopper 8 and using a permanent magnet as a material of the floating element, it is possible to move the floating element by the force of the electromagnet and release the valve. In this case, the actuator on the downstream side is moved. It can be omitted.

[0015]

As described above, according to the present invention, in the flow sending mechanism in which the pressure on the upstream side is higher than the pressure on the downstream side, the floating element is provided on the upstream side of the flow passage hole of the blocking wall, and the upstream side is provided. Since the fluid is dammed by the pressure of 1, the fluid can be controlled without leakage even if the pressure on the upstream side changes. Further, since the seed core of the float has a conical shape, the actuator can push up the float with a slight force.

[Brief description of drawings]

FIG. 1 is a perspective view of a fluid control valve floating element according to the present invention.

FIG. 2 is a sectional view of a fluid control valve of the present invention.

FIG. 3 is a diagram showing an operating state of the floating element of the present invention.

FIG. 4 is a perspective view of the stopper of the present invention.

FIG. 5 is a sectional view when a stopper is formed on the inner wall of the pipe of the present invention.

FIG. 6 is a schematic diagram showing the structure of a conventional check valve.

[Explanation of symbols]

101 floating child 102 Main pillar 103 Main pillar bottom 104 Thin film umbrella 105 connecting rod 106 stopper 2 barrier 3 channel holes 4 diaphragm 5 actuators 6 ports 7 Notch groove 8 Stoppers (stoppers)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masayuki Suda             1-8 Nakase, Nakase, Mihama-ku, Chiba City, Chiba Prefecture             Ico Instruments Co., Ltd. F-term (reference) 3H052 AA01 BA02 BA25 CA01 CA15                       DA01                 3H060 AA04 BB08 CC04 CC15 CC22                       DA01 DA15 DC09 DD02 DD12                       DD13 HH02 HH05                 3H062 AA02 AA15 BB28 BB30 CC08                       EE06 HH02 HH03                 3H106 DA03 DC02 DD02 EE23 EE34                       EE39 GB06                 3J071 AA01 AA11 BB14 CC12 DD36

Claims (7)

[Claims] 1. A flow sending device having a mechanism for sending a fluid such as a liquid or a gas, wherein a blocking wall blocking a part of a flow channel, a flow channel hole formed in the blocking wall, and pressure from an upstream side are used. A fluid control valve having a floating element for closing the flow path hole and a mechanism for pushing the floating element back to the upstream side against the pressure on the upstream side. 2. The barrier wall is made of glass bonded to a silicon wafer, has a diaphragm type bimorph downstream of the flow passage hole, and passes through the flow passage hole when the bimorph is driven. The fluid control valve according to claim 1, wherein a part of the floating element contacts the bimorph and pushes back the floating element. 3. The floating element has a structure in which a conical main pillar portion and a thin film umbrella portion having an area larger than the bottom surface of the main pillar portion are added to the bottom surface of the main pillar portion. The fluid control valve according to. 4. The fluid control valve according to claim 1, wherein the thin film umbrella portion of the floating valve is divided into a plurality of parts. 5. The fluid control valve according to claim 1, further comprising a mechanism for restricting a movement of the floating valve in a flow path upstream of the floating element. 6. The method according to claim 1, wherein the contact portion of the floating element with the diaphragm has a larger area than the flow path hole, and has a notch in a part of the surface in contact with the glass. Fluid control valve. 7. The fluid control valve according to claim 1, wherein the floating element is made of a magnetic material, and is driven by an electromagnet installed on the upstream side of the flow path.