JP6031432B2 - Sensor switch, filter device, sensor switch adjustment method and program - Google Patents

Description

  The present invention relates to a sensor switch that switches between ON and OFF according to a change amount of a sensor target, a filter device including the sensor switch, a sensor switch adjustment method, and a program.

  As a sensor switch that switches between ON and OFF in accordance with a change amount of a sensor target, a sensor switch that includes a sensor element, a magnet provided in the sensor element, and a reed switch is known. These output ON or OFF signals according to the positional relationship between the reed switch and a magnet that is displaced according to changes in the shape and position of the sensor element.

  For example, as a sensor element, a pressure element such as a diaphragm or a piston whose shape and position changes depending on pressure is used. When a magnet provided in the pressure element comes close to the reed switch, ON is output, and OFF when separated. There is a differential pressure switch that outputs (for example, Patent Document 1). This differential pressure switch is used, for example, in a filter device that allows fluid to pass through a filter, in order to detect clogging of the filter, in order to detect pressure reduction in the flow path.

  The differential pressure switch described in Patent Document 1 is a switch that switches between ON and OFF in accordance with the differential pressure between one chamber and the other chamber, and includes a magnet that operates in conjunction with a piston that partitions one chamber from the other chamber, The reed switch operates in response to the magnet when the piston moves by a predetermined amount due to the low pressure in one chamber.

JP 2003-139636 A

  Such sensor switches have variations in the characteristics of parts such as permanent magnets and reed switches. Therefore, in order to ensure that the reed switch switches when the change amount of the sensor target reaches the set value, It is necessary to finely adjust the distance between the switch and the permanent magnet.

  The differential pressure switch of Patent Document 1 explains that since the position of the reed switch is finely adjusted by the position adjusting means, the reed switch can be switched reliably when the differential pressure reaches a set value.

  Specifically, the reed switch holder is provided with a female thread, the guide cylinder that guides the vertical movement of the piston is provided with a male thread, the female screw and the male thread are screwed, and the reed switch holder moves spirally around the guide cylinder Thus, the positional relationship between the reed switch and the magnet provided on the piston in the guide tube portion is finely adjusted.

  At this time, in order to avoid the force applied to the lead wire of the reed switch due to the rotation of the reed switch holder, it is constituted by a collar provided at the end of the lead wire or an insertion port having a counterbore for locking the collar. It was necessary to provide lead wire locking means.

  As described above, the conventional sensor switch requires a large number of parts to finely adjust the positional relationship between the reed switch and the permanent magnet, and thus has a complicated configuration. Therefore, the manufacturing process increases and the cost also increases. There was a problem.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a sensor switch or the like that operates reliably at a set value with a simple configuration.

In order to achieve the above object, a sensor switch according to the first aspect of the present invention provides:
A sensor switch that is turned off when the pressure in the variable pressure chamber is below a set value;
A diaphragm separating the fixed pressure chamber adjacent to the variable pressure chamber and the variable pressure chamber;
A lid-like body that is rotatably provided with respect to the diaphragm, forms the fixed pressure chamber with the diaphragm, and has a plurality of protrusions on a surface facing the diaphragm;
A reed switch that is provided inside the lid-like body and is turned on when two opposing ferromagnetic leads are brought into contact with each other at a contact portion, and turned off when separated;
An intermediate point between the north and south poles is located at the center of the diaphragm and moves on a first straight line passing through the contact portion of the reed switch and in a direction substantially perpendicular to the extending direction of the ferromagnetic lead. a, and a permanent magnet having a magnetic pole direction substantially on a plane perpendicular to the first straight line including the midpoint,
The lid changes the angle formed by the rotation direction of the ferromagnetic lead and the magnetic pole direction of the permanent magnet by rotation, and the intermediate point of the permanent magnet corresponds to the set value of the sensor target When the position of the point on the first straight line is closer to the reed switch, the reed switch is changed and fixed so that the reed switch is turned on,
The diaphragm comes into contact with the protrusion when the pressure in the variable pressure chamber is greater than a predetermined value equal to or greater than the set value.
It is characterized by that.

  You may make it further provide the spring which urges | biases the said diaphragm to the direction of the said reed switch.

Moreover, the filter device according to the second aspect of the present invention provides:
Comprising a sensor switch according to a first aspect;
A filter device having a filter at the inlet of the variable pressure chamber, wherein the fluid passes through the filter by sucking the fluid from the outlet of the variable pressure chamber;
A clogging determination unit that outputs a determination result indicating that the filter is clogged based on the reed switch being turned off when the pressure of the variable pressure chamber becomes equal to or lower than the set value;
It is characterized by that.

Moreover, the sensor switch adjustment method according to the third aspect of the present invention includes:
A diaphragm separating the fixed pressure chamber adjacent to the variable pressure chamber and the variable pressure chamber;
A lid-like body that is rotatably provided with respect to the diaphragm, forms the fixed pressure chamber with the diaphragm, and has a plurality of protrusions on a surface facing the diaphragm;
A reed switch that is provided inside the lid-like body and is turned on when two opposing ferromagnetic leads are brought into contact with each other at a contact portion, and turned off when separated;
An intermediate point between the north and south poles is located at the center of the diaphragm and moves on a first straight line passing through the contact portion of the reed switch and in a direction substantially perpendicular to the extending direction of the ferromagnetic lead. And a permanent magnet having a magnetic pole direction on a surface that includes the intermediate point and is substantially perpendicular to the first straight line, and a sensor switch adjustment method comprising:
By rotating the lid, the angle formed by the extending direction of the ferromagnetic lead and the magnetic pole direction of the permanent magnet is changed, and the intermediate point of the permanent magnet becomes the set value of the sensor target. when the position point on the corresponding first linear closer to the reed switch, an angle determining step of determining the angle that the reed switch is oN,
Change to the angle determined in the previous SL angle determination step includes an angle fixing step of fixing the lid-like body to the angle, and
The diaphragm comes into contact with the protrusion when the pressure in the variable pressure chamber is greater than a predetermined value equal to or greater than the set value.
It is characterized by that.

A program according to the fourth aspect of the present invention is:
A diaphragm separating the fixed pressure chamber adjacent to the variable pressure chamber and the variable pressure chamber;
A lid-like body that is rotatably provided with respect to the diaphragm, forms the fixed pressure chamber with the diaphragm, and has a plurality of protrusions on a surface facing the diaphragm;
A reed switch that is provided inside the lid-like body and is turned on when two opposing ferromagnetic leads are brought into contact with each other at a contact portion, and turned off when separated;
An intermediate point between the north and south poles is located at the center of the diaphragm and moves on a first straight line passing through the contact portion of the reed switch and in a direction substantially perpendicular to the extending direction of the ferromagnetic lead. has, a computer for controlling the sensor switch and a permanent magnet having a magnetic pole direction substantially on a plane perpendicular to the first straight line including the midpoint,
By rotating the lid, the angle formed by the extending direction of the ferromagnetic lead and the magnetic pole direction of the permanent magnet is changed, and the intermediate point of the permanent magnet becomes the set value of the sensor target. when the position point on the corresponding first linear closer to the reed switch, the angle determination unit configured to determine the angle that the reed switch is oN,
To function as,
The diaphragm comes into contact with the protrusion when the pressure in the variable pressure chamber is greater than a predetermined value equal to or greater than the set value.
It is characterized by that.

  According to the present invention, it is possible to reliably operate the sensor switch at the set value with a simple configuration.

It is a partial sectional view of a filter device concerning an embodiment. It is a side view of a reed switch holding part. It is sectional drawing of a part of filter apparatus when the pressure of the variable pressure chamber of a filter apparatus falls. It is a figure for demonstrating rotation operation of a reed switch holding | maintenance part. The angle between the extending direction of the ferromagnetic lead of the reed switch and the extending direction of the permanent magnet is (a) 20 °, (b) 30 °, and (c) 10 °. It is a figure which shows the relationship between the rotation angle of a reed switch holding | maintenance part, and the reaction value of a pressure. It is a flowchart which shows an angle determination process.

(Embodiment)
Embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, the right direction on the paper is the X direction, the upper direction on the paper is the Z direction, and the direction perpendicular to the paper is the Y direction.

  As shown in FIG. 1, the filter device 1 according to the present embodiment includes a case 10 in which a filter is provided at the inlet and fluid that has passed through the filter flows inside, a diaphragm 12 that seals an opening of the case 10, and leads A reed switch holding unit 16 that holds the switch 14 is provided. FIG. 1 is a view as seen in the Y direction from a cross section on the XZ plane having the contact point A of the reed switch 14 as an origin.

  The case 10 includes a spring 101 that biases the back surface of the diaphragm 12. A prismatic permanent magnet 18 is provided on the back surface of the diaphragm 12. In a space formed between the case 10 and the diaphragm 12, a variable pressure chamber 102 in which the pressure changes according to the flow of the fluid is formed.

  The reed switch holding portion 16 has a shape of a lid having a cavity inside, and is rotatably fitted to the opening of the case 10 by a locking projection 161 provided on the edge of the lid. A fixed pressure chamber 162 having a constant pressure is formed in a space formed between the reed switch holding portion 16 and the diaphragm 12 in the fitted state. The fixed pressure chamber 162 may be at atmospheric pressure by providing the reed switch holding part 16 with a vent hole. In addition, the reed switch holding part 16 has a protrusion 163 for avoiding the diaphragm 12 sticking to the reed switch holding part 16.

  The reed switch 14 is a switch that is turned on when two opposing ferromagnetic leads 141 are magnetized by a magnetic field applied from the outside and the opposite free ends are attracted to each other so that they contact each other at the contact portion A. It is. The reed switch 14 is fixed to the reed switch holding part 16, and the contact part A of the reed switch 14 is located at the center of the fixed pressure chamber 162 of the reed switch holding part 16 when viewed from the side as shown in FIG. To position. As shown in FIG. 1, one of the lead wires extending from the ferromagnetic lead 141 of the reed switch 14 is folded, and the two lead wires extend in the −Z direction.

  The permanent magnet 18 is fixed to the diaphragm 12 so that the intermediate point is located on a first straight line C that passes through the contact point A of the reed switch 14 and is substantially perpendicular to the extending direction B of the ferromagnetic lead 141. . At this time, the magnetic pole direction D of the permanent magnet 18 is on a plane substantially perpendicular to the first straight line C including the intermediate point.

  The variable pressure chamber 102 is provided with an inlet 103 provided with a filter and an outlet (not shown). By sucking fluid from the outlet, the fluid that has passed through the filter flows into the variable pressure chamber 102. Here, when the fluid can be sufficiently passed without clogging the filter, since the pressure above the fixed pressure chamber 102 is maintained at a certain level, the diaphragm 12 is protruded by the tension of the spring 101. It is in the state which contacted the part 163 (FIG. 1). At this time, since the permanent magnet 18 is sufficiently close to the reed switch 14, the reed switch 14 is ON.

  On the other hand, when the fluid cannot sufficiently pass due to clogging of the filter, the pressure in the variable pressure chamber 102 is reduced by the suction force from the outlet. As the pressure decreases, the central portion of the diaphragm 12 moves away from the protrusion 163 and the permanent magnet 18 moves away from the reed switch 14 as shown in FIG. The reed switch 14 is turned off when the pressure becomes a set value or less and the distance between the intermediate point of the permanent magnet 18 and the contact point A of the reed switch 14 becomes a predetermined value or more. Here, the position of the intermediate point of the permanent magnet 18 when the reed switch 14 is OFF is the point position on the first straight line C corresponding to the set value of pressure.

  Here, since there are individual differences in the performance of the permanent magnet 18 and the reed switch 14, the positional relationship between the reed switch 14 and the permanent magnet 18 when the reed switch 14 is switched ON and OFF may differ depending on the parts used. is there. That is, there is a possibility that a difference occurs in the pressure of the variable pressure chamber 102 when the reed switch 14 is switched ON and OFF. Therefore, it is necessary to finely adjust the positional relationship between the reed switch 14 and the permanent magnet 18 so that the reed switch 14 is switched ON and OFF reliably at a predetermined pressure.

  In the present embodiment, the reed switch holding portion 16 is fitted to the case 10, and the positional relationship in the X direction is unchanged. On the other hand, since the reed switch holding part 16 is rotatable with respect to the case 10, the extending direction B of the ferromagnetic lead 141 of the reed switch 14 and the magnetic pole direction D of the permanent magnet 18 are shown in FIG. The angle formed can be changed and fixed at an appropriate angle. That is, in the present embodiment, the reed switch holding unit 16 functions as an angle fixing unit.

  By finely adjusting the angle formed by the direction B and the direction D, the reed switch 14 is switched on and off at a predetermined pressure. As a specific procedure, an angle at which the reed switch 14 is switched between ON and OFF at a predetermined pressure is determined, and the reed switch holding unit 16 is positioned at a position where the angle formed by the direction B and the direction D is the determined angle. Is fixed to the case 10. Hereinafter, the relationship between the angle formed by the direction B and the direction D and the pressure will be described in detail.

  When the same permanent magnet 18 and reed switch 14 are used, the angle between the direction B and the direction D is (a) 20 °, (b) 30 °, and (c) 10 ° as shown in FIG. The reed switch holding part 16 is fixed to the case 10. At each angle, the pressure at which the reed switch 14 was switched from ON to OFF when the pressure was lowered was measured. (A) With reference to the time of 20 °, the pressure switched from ON to OFF was +0.3 kPa at (b) 30 °, and (c) −0.2 kPa at 10 °. It was.

  The relationship between the angle formed by the direction B and the direction D and the pressure (reaction value) at which the reed switch 14 is switched from ON to OFF continuously changes as shown in FIG.

  By utilizing this property, the angle at which the reed switch 14 is switched from ON to OFF with a predetermined pressure can be determined for each of the filter devices using different reed switches 14 and permanent magnets 18.

An angle determination process for determining an angle formed by the direction B and the direction D will be described with reference to the flowchart of FIG. This process is executed by a control computer having a function of controlling the pressure of the variable pressure chamber 102 and a function of detecting ON / OFF of the reed switch 14. The control computer is a memory that stores various parameters such as a pressure set value Pa used in the angle determination process, angles θ _{1 to} θ _nh formed by the directions B and D, and pressures P _{1 to} θ _mk of the variable pressure chamber 102. Have

First, the pressure set value Pa is acquired (step S101). The set value Pa is a value stored in advance in the memory or a value input by the user. Next, the angle formed by the extending direction B of the ferromagnetic lead 141 of the reed switch 14 and the magnetic pole direction D of the permanent magnet 18 is sequentially changed. Specifically, in the n = 1 (step S102), the angle of the direction B and direction D to theta _n (step S103). Here, the angle formed by the direction B and the direction D may be changed by using an angle changing device that automatically changes the angle, and the case 10 or the reed switch holding unit 16 is provided with a scale indicating the angle. The angle may be changed manually.

Next, in the m = 1 (step S104) to set the pressure of the variable pressure chamber 102 to _{P m} (Step S105). At this time, it is determined whether the reed switch 14 is OFF (step S106). If reed switch 14 was turned OFF (step S106; Yes), stores the pressure _{P m} at that time in the memory (step S107). If the read switch 14 is not turned OFF (step S106; No), m is incremented by 1 if (step S108), m is equal to or less than _{m k} (step S109; No), the flow returns to step S105. Then repeat steps S105 to S109, gradually reducing the pressure, and stores the pressure _{P m} when the reed switch is turned OFF in the memory (step S107).

When m exceeds _{m k} at step S109 (step S109; Yes) n is incremented by 1 if (step S110), n is less than or equal to _{n h} (step S111; No), the flow returns to step S103. Then, a step S103～S111, repeatedly executes a different angle from theta ₁ to theta _nh. With these processes, the pressure P _m when the reed switch is turned off when the pressure is reduced is stored in the memory for each angle θ _n (step S107). if n exceeds _{n h} (step S111; Yes), the process proceeds to step S112.

By reed switch in each angle to obtain a pressure P _m when switched to OFF, it is possible to obtain the pressure relationship when the angle and reed switch formed by the direction B and direction D is turned OFF. Based on the relationship between the angle and the pressure, an angle at which the reed switch 14 is turned OFF when the pressure set value Pa is obtained in step S101 is obtained, and the angle is stored in the memory (step S112). And the angle which the direction B and the direction D make is set to the angle calculated | required by step S112.

  By the above processing, the angle can be set such that the reed switch 14 is reliably switched from ON to OFF with a predetermined pressure as a boundary.

  As described above, in the present embodiment, the filter device 1 passes through the reed switch 14 and the contact portion A of the reed switch 14, and the first straight line C in the direction substantially perpendicular to the lead extending direction of the reed switch 14. A permanent magnet 18 is provided so as to have an intermediate point between the N pole and the S pole at a point moving upward, and to have a magnetic pole direction on a plane that includes the intermediate point and is substantially perpendicular to the first straight line C. Then, the angle formed by the extending direction B of the ferromagnetic lead 141 of the reed switch 14 and the magnetic pole direction D of the permanent magnet 18 is changed so that the pressure in the variable pressure chamber 102 becomes equal to or lower than a predetermined pressure. The angle is fixed so that the reed switch 14 sometimes switches from ON to OFF. As a result, even if there are variations in the performance of components such as the reed switch 14 and the permanent magnet 18, the reed switch 14 can be reliably operated at a preset pressure setting value with a simple configuration.

  In this embodiment, the pressure sensor switch has been described in which the position of the permanent magnet 18 is changed due to a change in pressure, and thereby the ON / OFF of the reed switch 14 is switched. However, the reed switch 14 of the present embodiment The configuration of changing the angle formed by the extending direction B of the ferromagnetic lead 141 and the magnetic pole direction D of the permanent magnet 18 can be applied to other sensors. For example, the present invention can be applied to a position sensor, a liquid level sensor, a proximity sensor, an open / close sensor, and the like. These are sensors that detect that the amount of change in the sensor target is greater than or less than a preset set value, and the position of the permanent magnet 18 changes according to the amount of change in the sensor target. As in the present embodiment, the extending direction B of the ferromagnetic lead 141 of the reed switch 14 and the permanent magnet 18 are ensured so that the reed switch 14 can be reliably operated at a predetermined change amount set value. The angle formed by the magnetic pole direction D is determined.

  As described above, according to the present invention, the reed switch that is turned on when two opposing ferromagnetic leads come into contact with each other at the contact portion and turned off when separated from each other, and the extending direction of the ferromagnetic lead through the contact portion. A permanent magnet having an intermediate point between the N pole and the S pole at a point moving on the first straight line in the vertical direction and having a magnetic pole direction on a plane that includes the intermediate point and is substantially perpendicular to the first straight line. In the sensor switch, the ferromagnetic lead is extended so that the reed switch is turned on when the intermediate point of the permanent magnet is close to the reed switch by the point position on the first straight line corresponding to the set value of the sensor object. The angle formed by the direction and the magnetic pole direction of the permanent magnet is determined and fixed at that angle. As a result, the reed switch can be reliably operated at the set value with a simple configuration.

  In addition, this invention is not limited to the said embodiment, Of course, the various change in the range which does not deviate from the summary of this invention is possible.

  For example, the above embodiment relates to a pressure sensor switch in which the reed switch 14 is switched from ON to OFF when the permanent magnet 18 provided in the diaphragm 12 moves away from the reed switch 14 when the pressure in the variable pressure chamber 102 decreases. However, it may be a sensor switch in which the reed switch 14 is switched from OFF to ON when the permanent magnet 18 approaches the reed switch 14. For example, in the case of a filter device that includes a filter at the outlet instead of the inlet 103 of the variable pressure chamber 102 and allows the filter to pass through by flowing fluid from the inlet 103, the pressure in the variable pressure chamber 102 is low during normal operation, and the filter is clogged. When this occurs, the pressure in the variable pressure chamber 102 increases. When the pressure in the variable pressure chamber 102 increases, the permanent magnet 18 provided in the diaphragm 12 approaches the reed switch 14, so that the reed switch 14 is switched from OFF to ON. In such a configuration, the angle formed between the extending direction B of the ferromagnetic lead 141 of the reed switch 14 and the magnetic pole direction D of the permanent magnet 18 is changed, and the pressure in the variable pressure chamber 102 is set to a predetermined pressure. At this time, the reed switch 14 is fixed at an angle that switches from OFF to ON.

  The angle determination processing program may be distributed by any distribution method. For example, it may be stored in a computer-readable recording medium such as a CD-ROM (Compact Disk Read-Only Memory), a DVD (Digital Versatile Disk), an MO (Magneto Optical Disk), a memory card, etc., or distributed over the Internet. You may distribute via a communication network.

DESCRIPTION OF SYMBOLS 1 ... Filter apparatus 10 ... Case 101 ... Spring 102 ... Variable pressure chamber 103 ... Inlet 12 ... Diaphragm 14 ... Reed switch 141 ... Ferromagnetic lead 16 ... Reed switch holding part 161 ... Locking protrusion 162 ... Fixed pressure chamber 163 ... Projection Part 18 ... Permanent magnet

Claims (5)

A sensor switch that is turned off when the pressure in the variable pressure chamber is below a set value;
A diaphragm separating the fixed pressure chamber adjacent to the variable pressure chamber and the variable pressure chamber;
A lid-like body that is rotatably provided with respect to the diaphragm, forms the fixed pressure chamber with the diaphragm, and has a plurality of protrusions on a surface facing the diaphragm;
A reed switch that is provided inside the lid-like body and is turned on when two opposing ferromagnetic leads are brought into contact with each other at a contact portion, and turned off when separated;
An intermediate point between the north and south poles is located at the center of the diaphragm and moves on a first straight line passing through the contact portion of the reed switch and in a direction substantially perpendicular to the extending direction of the ferromagnetic lead. a, and a permanent magnet having a magnetic pole direction substantially on a plane perpendicular to the first straight line including the midpoint,
The lid changes the angle formed by the rotation direction of the ferromagnetic lead and the magnetic pole direction of the permanent magnet by rotation, and the intermediate point of the permanent magnet corresponds to the set value of the sensor target When the position of the point on the first straight line is closer to the reed switch, the reed switch is changed and fixed so that the reed switch is turned on,
The diaphragm comes into contact with the protrusion when the pressure in the variable pressure chamber is greater than a predetermined value equal to or greater than the set value.
A sensor switch characterized by that. A spring for urging the diaphragm toward the reed switch;
The sensor switch according to claim 1 . A sensor switch according to claim 1 or 2 ,
A filter device having a filter at the inlet of the variable pressure chamber, wherein the fluid passes through the filter by sucking the fluid from the outlet of the variable pressure chamber;
A clogging determination unit that outputs a determination result indicating that the filter is clogged based on the reed switch being turned off when the pressure of the variable pressure chamber becomes equal to or lower than the set value;
And a filter device. A diaphragm separating the fixed pressure chamber adjacent to the variable pressure chamber and the variable pressure chamber;
A lid-like body that is rotatably provided with respect to the diaphragm, forms the fixed pressure chamber with the diaphragm, and has a plurality of protrusions on a surface facing the diaphragm;
A reed switch that is provided inside the lid-like body and is turned on when two opposing ferromagnetic leads are brought into contact with each other at a contact portion, and turned off when separated;
An intermediate point between the north and south poles is located at the center of the diaphragm and moves on a first straight line passing through the contact portion of the reed switch and in a direction substantially perpendicular to the extending direction of the ferromagnetic lead. And a permanent magnet having a magnetic pole direction on a surface that includes the intermediate point and is substantially perpendicular to the first straight line, and a sensor switch adjustment method comprising:
By rotating the lid, the angle formed by the extending direction of the ferromagnetic lead and the magnetic pole direction of the permanent magnet is changed, and the intermediate point of the permanent magnet becomes the set value of the sensor target. when the position point on the corresponding first linear closer to the reed switch, an angle determining step of determining the angle that the reed switch is oN,
Change to the angle determined in the previous SL angle determination step includes an angle fixing step of fixing the lid-like body to the angle, and
The diaphragm comes into contact with the protrusion when the pressure in the variable pressure chamber is greater than a predetermined value equal to or greater than the set value.
A method for adjusting a sensor switch. A diaphragm separating the fixed pressure chamber adjacent to the variable pressure chamber and the variable pressure chamber;
A lid-like body that is rotatably provided with respect to the diaphragm, forms the fixed pressure chamber with the diaphragm, and has a plurality of protrusions on a surface facing the diaphragm;
A reed switch that is provided inside the lid-like body and is turned on when two opposing ferromagnetic leads are brought into contact with each other at a contact portion, and turned off when separated;
An intermediate point between the north and south poles is located at the center of the diaphragm and moves on a first straight line passing through the contact portion of the reed switch and in a direction substantially perpendicular to the extending direction of the ferromagnetic lead. has, a computer for controlling the sensor switch and a permanent magnet having a magnetic pole direction substantially on a plane perpendicular to the first straight line including the midpoint,
By rotating the lid, the angle formed by the extending direction of the ferromagnetic lead and the magnetic pole direction of the permanent magnet is changed, and the intermediate point of the permanent magnet becomes the set value of the sensor target. when the position point on the corresponding first linear closer to the reed switch, the angle determination unit configured to determine the angle that the reed switch is oN,
To function as,
The diaphragm comes into contact with the protrusion when the pressure in the variable pressure chamber is greater than a predetermined value equal to or greater than the set value.
A program characterized by that .

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