WO2019159698A1

WO2019159698A1 - Fluid control valve

Info

Publication number: WO2019159698A1
Application number: PCT/JP2019/003294
Authority: WO
Inventors: 富田　英夫; 杉山　正樹; 永沼　直人; 博昭片瀬
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2018-02-16
Filing date: 2019-01-31
Publication date: 2019-08-22
Also published as: JP2019143649A

Abstract

This fluid control valve comprises a valve body (13) that opens and closes a flow channel, a magnet (23) secured to the valve body (13) so that an S pole (24) and an N pole (25) are positioned forward and rearward with respect to the movement direction of the valve body (13), a two-pole detection Hall IC (30) having an S pole and N pole to the side of the magnet (23) relative to the movement direction, and an actuator that drives the valve body (13). The two-pole detection Hall IC (30), in which a magnetosensitive part is disposed along a direction in which magnetic flux density directed toward the center axis of the magnet (23) is applied, detects the magnetic flux density of a first pole, which is one of the S pole (24) and the N pole (25), at or above an operative magnetic flux density when the valve body (13) is closed, and detects the magnetic flux density of a second pole, which is the other of the S pole (24) and the N pole (25), at or above an operative magnetic flux density when the valve body (13) is open, whereby the position of the valve body (13) is assessed.

Description

Fluid control valve

The present invention relates to a fluid control valve. More specifically, the present invention relates to a fluid control valve capable of detecting the position of a valve body.

A conventional fluid control valve will be described. A conventional fluid control valve includes a stepping motor that is an electric motor, a conversion unit that is locked to a rotation shaft of the stepping motor and converts rotation of the rotation shaft to linear motion, and a valve body that is locked to the conversion unit and opens and closes a flow path And a valve body position detector. As a position detection unit of a valve body used in a conventional fluid control valve, a magnet provided at one end of the valve body and an open magnetic detection element for detecting the open state of the valve body arranged on the outer surface of the flow path And the structure which provides the magnetic detection element for closing which detects the closed state of a valve body is disclosed (for example, refer patent document 1).

JP 2001-141094 A

However, in the conventional configuration, the valve body moves and opens and closes the flow path by the conversion unit that converts the rotation of the rotation shaft of the stepping motor into a linear motion. At that time, in order to detect the magnet when the valve element is in the open state and the magnet when the valve element is in the closed state, a dedicated opening magnetic detecting element and a closing magnetic detecting element are required. Further, the orientations of the N and S poles of the magnet, their arrangement, the characteristics of the opening magnetic detection element and the closing magnetic detection element, and specific examples thereof are not disclosed.

The present invention provides a fluid control valve that provides one S pole and N pole detection type Hall IC on the side of the moving direction of the magnet to detect the open state and the closed state of the valve element.

The fluid control valve according to the present invention includes a valve body that opens and closes a flow path, a magnet that is fixed to the valve body so that the S pole and the N pole are positioned forward and backward with respect to the moving direction of the valve body, and the movement of the magnet S pole and N pole detection type Hall IC located on the side of the direction, and an actuator for driving the valve body. In the bipolar detection type Hall IC in which the magnetic sensing portion is arranged in the direction of applying the magnetic flux density toward the central axis of the magnet, the magnetic flux density of one of the S pole and the N pole is the operating magnetic flux density when the valve body is closed. When the valve body is opened, the position of the valve body is determined by detecting that the magnetic flux density of the other second pole of the S pole and the N pole is equal to or higher than the operating magnetic flux density.

With this configuration, when the actuator is driven to move the valve body and the magnet to the closed state, the bipolar detection type Hall IC detects that the magnetic flux density toward the central axis of the first pole is greater than or equal to the operating magnetic flux density It can be determined that the valve body is closed. On the other hand, when the actuator is driven to move the valve body and the magnet to the open state and the bipolar detection type Hall IC detects that the magnetic flux density toward the central axis of the second pole is equal to or higher than the operating magnetic flux density, It can be determined that the valve body is open.

As described above, according to the fluid control valve of the present invention, it is possible to detect the open state and the closed state of the valve by providing one bipolar detection type Hall IC on the side of the moving direction of the magnet.

FIG. 1 is a cross-sectional view showing an open state of the schematic configuration of the fluid control valve in the first embodiment. FIG. 2 is a cross-sectional view showing a closed state of the fluid control valve in the first embodiment. FIG. 3 is a perspective view of the fluid control valve according to the first embodiment. FIG. 4A is a perspective view of an actuator and a fluid control unit of the fluid control valve in the first embodiment. FIG. 4B is a perspective view of the valve body excluding the valve rubber of the fluid control valve in the first embodiment. FIG. 5 is a diagram illustrating a measurement result of magnetic flux density due to magnet movement of the fluid control valve in the first embodiment. FIG. 6 is a perspective view of the substrate on which the bipolar detection type Hall IC of the fluid control valve according to the first embodiment is attached. FIG. 7 is an enlarged cross-sectional view of a main part of the fluid control valve in the first embodiment.

(First embodiment)
FIG. 1 is a cross-sectional view showing an open state of a fluid control valve in the present embodiment. FIG. 2 is a cross-sectional view showing a closed state of the fluid control valve in the present embodiment. FIG. 3 is a perspective view of the fluid control valve in the present embodiment. FIG. 4A is a perspective view of the actuator and fluid control unit of the fluid control valve in the present embodiment. FIG. 4B is a perspective view of the valve body excluding the valve rubber of the fluid control valve in the present embodiment.

Hereinafter, the fluid control valve in the present embodiment will be described with reference to FIGS.

In addition, as a general rule, directions in the explanation shall follow the description of directions in each figure. Further, the fluid control valve in the present embodiment is controlled by a control unit (not shown).

1 to 4A and 4B, the fluid control valve 1 includes an actuator 2, a fluid control unit 3, and a flow path 4. The actuator 2 is a stepping motor that is an electric motor, and includes a stator 6 having a coil 5, a rotor 7 that rotates by excitation by energization of the coil 5, and a base 8 that supports the stator 6 and the rotor 7. The rotor 7 has a cylindrical shape, and includes an outer magnet 9, an inner rotary shaft 10, and a resin bush 11 that integrally molds the magnet 9 and the rotary shaft 10. The base 8 forms four comb-like upper rotation suppression plates 12 protruding downward.

The fluid control unit 3 includes a valve body 13 made of polyacetal resin (POM) and a conversion unit 14 that converts the rotation of the rotary shaft 10 of the actuator 2 into a linear motion. The valve body 13 includes a valve rubber receiver 15, a valve rubber 16, and a spring 17. Further, the valve body 13 is moved between an open state of the valve and a closed state of the valve by the actuator 2. In this embodiment, the moving path is set to 6 mm.

The valve rubber receiver 15 forms a cylindrical portion 20 in which a short female screw 19 having a screw pitch of 1 to 2 locked to a male screw 18 formed at the tip of the rotary shaft 10 is formed. A cylindrical aperture may be used instead of the female screw 19. Further, the valve rubber receiver 15 has a disk 21 for attaching the valve rubber 16 on the lower surface, and four comb-like lower rotation suppression plates 22 protruding from the disk 21 toward the base 8 (upward).

Further, a magnet 23 serving as a marker is fixed to the upper surface of the disk 21 by a resin spring (adhesion, press-fitting, etc.) so as to contact the outer peripheral edge of the disk 21 (see FIG. 4B). In the present embodiment, the magnet 23 is a cylinder Φ4.0 × t1.5, and the material is neodymium. Magnetization of the magnet 23 is in the thickness direction. As shown in FIG. 4B, the S pole 24 is positioned on the upper side, which is the side away from the disk 21, and the N pole 25 is positioned on the lower side, which is on the disk 21 side.

The spring 17 is slidably provided in a compressible direction between the base 8 and the valve rubber receiver 15 and biases the valve rubber receiver 15 and the valve rubber 16 toward the valve seat 27. The conversion unit 14 is configured by fitting the upper rotation suppression plate 12 and the lower rotation suppression plate 22.

The flow path 4 is made of resin and has an L-shaped cylinder as shown in FIG. 3 and has an inlet 26, a valve seat 27, an outlet 28, and an actuator insertion port 29 opened. The actuator 2 is disposed in the actuator insertion port 29.

The S-pole and N-pole bipolar detection type Hall IC 30 is arranged on the side of the 6 mm moving path of the magnet 23 so as to be in direct contact with the outer surface of the flow path 4. The bipolar detection type Hall IC 30 performs ON / OFF operation with respect to the strength of the magnetic field of the S or N pole of the magnet.

As a specific example, as the bipolar detection type Hall IC 30, for example, EM-1791 (W2.1 × D2.1 × H0.55) manufactured by Asahi Kasei Electronics Co., Ltd. is used. The applied magnetic flux density of the EM-1791 is a direction penetrating the magnetic sensing part (Hall element), and two S poles or N poles are output depending on this direction. The operating magnetic flux density (absolute value) is 3.2 mT, the return magnetic flux density is 1.4 mT (absolute value), and the design (manufacturer recommended) operating magnetic flux density is around 6 mT. In addition to EM-1791, the bipolar detection type Hall IC 30 includes AN48836B manufactured by Panasonic Corporation.

The operating magnetic flux density is a threshold at which the bipolar detection type Hall IC 30 is turned on, and the return magnetic flux density is a threshold at which the bipolar detection type Hall IC 30 is turned off. On the other hand, in an AMR sensor (Anisotropic Magneto Resistive sensor: magnetoresistive effect element) which is one of the magnetic sensors, the applied magnetic flux density is in a direction across the surface of the magnetic sensitive part and is different from the Hall IC.

FIG. 5 shows a radius direction (toward the central axis of the magnet 23) when the magnet 23 is moved up and down about 10 mm with reference to a magnetic sensing portion (not shown) arranged parallel to the upper surface inside the bipolar detection type Hall IC 30. The result of having measured the magnetic flux density of this, the magnetic flux density of the axial (thickness) direction, and the magnetic flux density of the circumferential direction with the gauss meter is shown. The gauss meter is at the same position as the magnetic sensing part of the bipolar detection type Hall IC 30 and at a position 6 mm away from the cylindrical central axis of the magnet 23.

In the bipolar detection type Hall IC 30, when the magnet 23 moves along the central axis of the magnet 23 itself, the direction is opposite, but a radial magnetic flux density showing two large peaks is applied. More specifically, a position where the magnet 23 has moved about 3 mm upward and about 3 mm downward along the central axis of the magnet 23 from the magnetic sensing part of the bipolar detection type Hall IC 30 becomes a peak of the magnetic flux density in the radial direction. . Note that the magnetic flux density in the circumferential direction cannot be used because there is little change.

Also, the magnetic flux density in the axial (thickness) direction shows one large peak, but two Hall ICs are required for opening and closing, and cannot be used for the applied magnetic flux density. When the distance between the central axis of the magnet 23 and the magnetic sensing part of the bipolar detection type Hall IC 30 is shortened, the peak magnetic flux density position in the radial direction tends to be slightly separated.

Generally, as shown in FIG. 6, since the bipolar detection type Hall IC 30 is small, it is wired to the substrate 31. Four positioning holes 32 opened at the four corners of the substrate 31 and four positioning pins protruding from the outer surface of the flow path 4 so that the magnetic sensing part of the bipolar detection type Hall IC 30 is located in the middle of the 6 mm moving path of the magnet 23. Position at 33 (see FIG. 3).

The positioning pin 33 has a positioning hole 32 so that the upper surface 30a of the bipolar detection type Hall IC 30 is in contact with the outer surface of the flow path 4 so that the magnetic sensing part of the bipolar detection type Hall IC 30 can apply a magnetic flux density in the radial direction. Insert. On the other hand, in the case of the AMR sensor in this arrangement, the magnetic flux density in the axial (thickness) direction is applied to the magnetic sensitive part of the AMR sensor.

The operation and action of the fluid control valve 1 configured as described above will be described below.

First, as shown in FIG. 1, when the valve body 13 is in an open state, gas (white arrow) enters the flow path 4 from the inlet 26 (see FIG. 3) and passes through the valve seat 27 from the valve body 13 side. , Has flowed out of the outlet 28. The open state of the valve body 13 will be described with reference to FIG. Note that an elliptical arrow A shown in FIGS. 7A and 7B indicates lines of magnetic force directed from the N pole 25 to the S pole 24. As shown in FIG. 7A, since the magnet 23 is located 3 mm above the bipolar detection type Hall IC 30, the magnetic lines of force going out from the inside of the flow path 4 penetrate the magnetic sensing part of the bipolar detection type Hall IC 30. To do. That is, the magnetic flux density in the radial direction of the N pole 25 magnetic field is applied to the magnetic sensing part of the bipolar detection type Hall IC 30.

Specifically, as shown in FIG. 5, a magnetic flux density of about 7 mT, which is equal to or higher than the operating magnetic flux density, is applied to the magnetic sensing part (N pole) of the bipolar detection type Hall IC 30. Naturally, the magnetic flux density in the radial direction of the magnetic field of the S pole 24 is not applied to the magnetic sensing part (S pole) of the bipolar detection type Hall IC 30. Therefore, in order to confirm the position of the valve body 13, when a control unit (not shown) issues an instruction and power is supplied to the bipolar detection type Hall IC 30, the output for the N pole of the bipolar detection type Hall IC 30 is turned ON, S The pole output is OFF. From this, it can be determined that the valve body 13 is in the open state.

On the other hand, the closed state of the valve body 13 of FIG. 2 in which the gas is blocked by the valve rubber 16 will be described with reference to FIG. As shown in FIG. 7B, since the magnet 23 is located 3 mm below the bipolar detection type Hall IC 30, the magnetic field lines going from the outside to the inside of the flow path 4 penetrate the magnetic sensing part of the bipolar detection type Hall IC 30. To do. That is, the magnetic flux density in the radial direction of the S pole 24 magnetic field is applied to the magnetic sensitive part of the bipolar detection type Hall IC 30.

Specifically, as shown in FIG. 5, a magnetic flux density of about −7 mT, which is equal to or higher than the operating magnetic flux density, is applied to the magnetic sensing part (S pole) of the bipolar detection type Hall IC 30. Naturally, the magnetic flux density in the radial direction of the N pole 25 magnetic field is not applied to the magnetic sensing part (N pole) of the bipolar detection type Hall IC 30. Therefore, in order to confirm the position of the valve body 13, when the control unit gives an instruction and power is supplied to the bipolar detection type Hall IC 30, the output for the N pole of the bipolar detection type Hall IC 30 is OFF and the output for the S pole is ON. Is output. From this, it can be determined that the valve body 13 is closed. In the fluid control valve 1, the bipolar detection type Hall IC 30 can detect and confirm the position of the valve body 13 in this manner.

In FIG. 7B, the valve rubber 16 is omitted, so that the valve rubber 16 appears open. However, when the valve rubber 16 is mounted on the disc 21 of the valve body 13, the valve rubber 16 is attached to the valve seat 27. Closed contact.

Thereafter, power supply to devices (not shown) such as flow velocity measurement is stopped until the actuator 2 is driven or the bipolar detection type Hall IC 30 determines that the valve body 13 is in an open state. That is, since no gas is flowing, it is not necessary to supply power to other devices such as flow velocity measurement, and energy saving can be achieved.

Note that if the N pole 25 is arranged on the magnet 23 and the bottom (the disk 21 side) is arranged on the S pole 24, the output is reversed, so care must be taken. Similarly, if the bipolar detection type Hall IC 30 is mounted upside down, the output is reversed, so care must be taken.

Further, as shown in FIG. 5 and FIG. 7, in the opened state and the closed state of the valve body 13, the lines of magnetic force penetrating the magnetic sensing part of the bipolar detection type Hall IC 30 are in opposite directions, but the magnetic flux density in the radial direction is The absolute value is almost the same. Therefore, the magnet 23 is required to hold at least a magnetic force that provides an operating magnetic flux density that can be detected by the bipolar detection type Hall IC 30. In other words, it is not necessary to select a strong magnet 23 having an extra magnetic force (surface magnetic flux density) in consideration of the radial magnetic flux density difference between the opened state of the valve body 13 and the closed state of the valve body 13. That is, the large-sized and high-quality magnet 23 is not necessary.

By the way, in order to confirm the position of the valve body 13, when the control unit issues an instruction and power is supplied to the bipolar detection type Hall IC 30, both the N pole output and the S pole output of the bipolar detection type Hall IC 30 are ON or both. When OFF is output, it can be determined that the fluid control valve 1 is out of order, and then an alarm can be given to the effect that the fluid control valve 1 is out of order by display, sound, or the like.

As a result, it is possible to determine the open state and the closed state of the valve body 13 and the failure of the fluid control valve 1 by one bipolar detection type Hall IC 30.

Further, as shown in FIG. 5, the peak magnetic flux density in the radial direction is located at a 3 mm position where the moving distance of the magnet 23 with reference to the magnetically sensitive portion of the bipolar detection type Hall IC 30 is about twice the thickness of the magnet 23 itself. There is. In other words, the thickness of the magnet 23 is optimally 20% to 30% of the 6 mm moving path of the magnet 23.

For example, when the thickness of the magnet 23 is reduced to 15% of the moving path of 6 mm, the magnetic force of the magnet 23 naturally becomes weak and the position of the peak magnetic flux density in the radial direction approaches, so that the magnetic sensing part of the bipolar detection type Hall IC 30 A small magnetic flux density exceeding the peak magnetic flux density in the radial direction is applied to. In addition, the magnetic force (surface magnetic flux density) naturally decreases because the magnet 23 is thin. In order to compensate for this decrease in magnetic flux density, it is necessary to improve the magnetic force of the magnet by using a high-cost high-grade material. On the contrary, when the thickness of the magnet 23 is increased to 35% of the moving path of 6 mm, the position of the peak magnetic flux density in the radial direction is separated, so that the bipolar detection type Hall IC 30 applies the magnetic flux density before the peak magnetic flux density in the radial direction. Is done. However, since the magnet 23 is thicker, the magnetic force (surface magnetic flux density) is increased, so that an operating magnetic flux density or higher is applied to the bipolar detection type Hall IC 30, so that the position of the valve body 13 can be detected. However, the magnet 23 becomes unnecessarily large, and fixing to the valve body 13 becomes difficult.

Next, when the control unit drives the actuator 2, the rotating shaft 10 rotates and the rotational force is transmitted to the valve body 13 through the male screw 18 and the female screw 19. Next, due to the contact between the upper rotation suppression plate 12 and the lower rotation suppression plate 22, the valve body 13 is restrained from rotating, and moves straight 6 mm to the open state or the closed state. In the magnetic sensing part of the bipolar detection type Hall IC 30, when the valve element 13 moves about 2 mm, the applied magnetic flux density becomes less than the return magnetic flux density, and when the valve body 13 moves further 2 mm, the applied magnetic flux density exceeds the operating magnetic flux density of the opposite polarity. Become.

That is, the magnetic flux density applied to the magnetic sensing part of the bipolar detection type Hall IC 30 changes rapidly while the actuator 2 is driven, and is affected by the magnetic field, noise, and the like generated by the actuator 2. That is, while the actuator 2 is being driven, there is no point in using the bipolar detection type Hall IC 30 itself, so the position detection of the valve body 13 is stopped. That is, the bipolar detection type Hall IC 30 confirms whether the valve body 13 is in an open state or a closed state.

In this embodiment, a cylindrical neodymium magnet is used as the magnet 23. However, if the distance between the magnetic sensing part of the bipolar detection type Hall IC 30 and the central axis of the magnet is short, even a Samacoba magnet or a ferrite magnet having a weak magnetic force may be used. Good. That is, the material and shape of the magnet 23 are not limited as long as the magnetic sensing part of the bipolar detection type Hall IC 30 exceeds the operating magnetic flux density (the thickness of the magnet 23 is 20 to 30% of the moving path length of the magnet 23). ).

In addition, information regarding the magnetic flux density in the radial direction detected by the bipolar detection type Hall IC 30 is sent to and processed by some control unit, but the subject that performs this processing is not particularly limited. For example, when a control unit that controls the actuator 2 is provided, the control unit may have a function of processing such information. Alternatively, a controller for detecting the position of the valve body 13 may be provided separately from the controller. Further, the fluid control valve 1 of the present embodiment does not necessarily include a control unit.

The above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention. In particular, the fluid control valve can be mounted in any direction other than vertical, such as horizontal, diagonal, and mounting directions.

As described above, the first invention includes a valve body that opens and closes the flow path, and a magnet that is fixed to the valve body so that the S pole and the N pole are positioned forward and backward with respect to the moving direction of the valve body. And an S pole and N pole detection type Hall IC located on the side of the moving direction of the magnet, and an actuator for driving the valve body. The bipolar detection type Hall IC in which the magnetic sensing portion is arranged in the direction of applying the magnetic flux density toward the central axis of the magnet uses the magnetic flux density of one of the S pole and the N pole as the operating magnetic flux density when the valve body is closed. When the valve body is opened, the position of the valve body is determined by detecting that the magnetic flux density of the other second pole of the S pole and the N pole is equal to or higher than the operating magnetic flux density.

With this configuration, when the actuator is driven to move the valve body to the closed state, the magnet also moves with the valve body. Next, when the magnetic sensing part of the pole detection type Hall IC detects that the magnetic flux density toward the central axis of the magnet of the first pole of one of the S pole and the N pole is equal to or higher than the operating magnetic flux density, the valve body is closed. It can be judged and confirmed. The magnetic flux density toward the central axis of the first pole magnet is detected to be equal to or higher than the operating magnetic flux density, and at the same time, the magnetic flux density toward the central axis of the other second pole of the S pole and N pole is equal to or lower than the operating magnetic flux density. Can be determined and confirmed more reliably that the valve body is in the closed state.

Further, when the actuator is driven to move the valve body to the open state, when the magnetic sensing part of the bipolar detection type Hall IC detects that the magnetic flux density toward the central axis of the second pole is equal to or higher than the operating magnetic flux density, You can judge and confirm that your body is open. It is more reliable if the magnetic flux density toward the central axis of the second pole magnet is detected to be equal to or higher than the operating magnetic flux density and at the same time the magnetic flux density toward the central axis of the first pole magnet is detected to be equal to or lower than the operating magnetic flux density. It can be determined and confirmed that the valve body is open.

According to a second aspect of the present invention, in the first aspect of the invention, the bipolar detection type Hall IC is located in the middle of the moving path of the magnet that moves between the position of the magnet when the valve body is closed and the position of the magnet when the valve body is opened. May be arranged.

With this configuration, the magnetic flux density toward the central axis of the first pole magnet detected by the magnetic sensing part of the bipolar detection type Hall IC when the valve body is closed, and the central axis of the second pole magnet when the valve body is opened Although the direction is opposite to the magnetic flux density toward, the absolute value is almost the same. Therefore, the magnet should keep at least the magnetic force (surface magnetic flux density) that can be detected by the magnetic sensing part of the bipolar detection type Hall IC in consideration of variations such as the distance between the magnet and the bipolar detection type Hall IC. That's fine. That is, it is not necessary to select a strong magnet that retains an extra magnetic force in consideration of the magnetic flux density difference between the open state of the valve body and the closed state of the valve body. Therefore, a large, high-quality magnet is not necessary.

In the third invention, particularly in the second invention, the thickness of the magnet may be 20% or more and 30% or less of the length of the path along which the magnet moves between when the valve body is closed and when the valve body is opened.

The magnetic sensing part of the bipolar detection type Hall IC detects a substantially peak magnetic flux density. That is, since the magnetic flux density toward the central axis of the magnet peaks from the magnetic sensing part of the bipolar detection type Hall IC at a position about twice the thickness of the magnet, when the valve body is closed and when opened, If the length of the path along which the magnet moves is determined, the optimum magnet thickness is determined to be 20% to 30% of the length of the path.

In the fourth invention, particularly in any one of the first to third inventions, the position detection of the valve body by the bipolar detection type Hall IC may be stopped while the actuator is driven.

The bipolar detection type Hall IC can detect the magnetic flux density when the valve body is opened or closed. That is, during the movement of the magnet, the magnetic flux density toward the central axis of the magnet applied to the magnetic sensing part of the bipolar detection type Hall IC changes significantly, and at the same time, the magnetic field generated by the actuator moving the valve body, noise, etc. Therefore, it is meaningless to use a bipolar detection type Hall IC. In other words, the bipolar detection type Hall IC determines and confirms whether the valve body is in an open state or a closed state.

In the fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, when the bipolar detection type Hall IC cannot detect the operating magnetic flux density or more, the fluid control valve may be determined to be in failure.

With this configuration, the bipolar detection type Hall IC can determine the three states of the valve body in the closed state, the open state, and the failure.

The fluid control valve of the present invention is useful as a fluid control valve capable of detecting the position of the valve body with one bipolar detection type Hall IC.

2 Actuator 4 Flow path 13 Valve element 23 Magnet 24 S pole 25 N pole 30 Bipolar detection type Hall IC

Claims

A valve body for opening and closing the flow path;
A magnet fixed to the valve body such that the S pole and the N pole are positioned forward and backward with respect to the moving direction of the valve body;
S pole and N pole detection Hall IC on the side of the moving direction of the magnet,
An actuator for driving the valve body,
The bipolar detection type Hall IC in which the magnetic sensing portion is arranged in a direction in which the magnetic flux density toward the central axis of the magnet is applied has the magnetic flux density of one of the S pole and N pole when the valve body is closed. A fluid control valve that detects an operating magnetic flux density or more and detects the position of the valve body by detecting the magnetic flux density of the other second pole of the S pole and the N pole when the valve body is opened as the operating magnetic flux density or more. .
The bipolar detection type Hall IC is arranged in the middle of a moving path of the magnet that moves between a position of the magnet when the valve body is closed and a position of the magnet when the valve body is opened. The fluid control valve described in 1.
The fluid control valve according to claim 2, wherein a thickness of the magnet is 20% or more and 30% or less of a length of the moving path of the magnet.
The fluid control valve according to any one of claims 1 to 3, wherein detection of the position of the valve body by the bipolar detection type Hall IC is stopped while the actuator is driven.
The fluid control valve according to any one of claims 1 to 4, wherein when the bipolar detection type Hall IC cannot detect a magnetic flux density equal to or higher than an operating magnetic flux density, the fluid control valve is determined to be in failure.