WO2017010272A1

WO2017010272A1 - Position detection sensor

Info

Publication number: WO2017010272A1
Application number: PCT/JP2016/068967
Authority: WO
Inventors: 西川嘉晃
Original assignee: 株式会社テイエルブイ
Priority date: 2015-07-10
Filing date: 2016-06-27
Publication date: 2017-01-19
Also published as: JP6392990B2; JPWO2017010272A1

Abstract

A position detection sensor 70, equipped with a magnetic switch 72 and a movable member 73 to which a first permanent magnet 74 is attached, the movable member 73 being in direct or indirect contact with a subject and moving towards the magnetic switch 72 in concert with the displacement of the subject. In the position detection sensor 70, when the first permanent magnet 74 is caused, by the movement of the movable member 73, to approach the magnetic switch 72 up to a prescribed distance set in advance, the magnetic switch 72 senses the magnetism of the first permanent magnet 74 and switches ON. The position detection sensor 70 is equipped with a second permanent magnet 80 provided to a region in which the second permanent magnet 80 and the first permanent magnet 74 are at all times attracted to or repelled from each other.

Description

Position detection sensor

The present application relates to a position detection sensor that has a magnetic switch and detects the position of an object.

For example, as disclosed in Patent Document 1, a position detection sensor (position detection switch) that has a magnetic switch and detects the position of an object is known. In this patent document 1, the position detection sensor is provided in the liquid pumping device to detect the position of the float. In the liquid pumping device, the float rises and falls according to the liquid level, and when the float rises to a predetermined height, the stored liquid is discharged, and when the float lowers to a predetermined height, new liquid flows in and stores. Is done.

The position detection sensor includes a magnetic switch, a movable member (movable shaft) containing a permanent magnet, and a contact member (coil spring) in contact with the float. In the position detection sensor, the contact member contacts the float and rotates as the float rises. As the contact member rotates, the movable member moves toward the magnetic switch. That is, as the float rises, the permanent magnet built in the movable member approaches the magnetic switch. When the float rises to a predetermined high level and the distance between the magnetic switch and the permanent magnet reaches a predetermined value, the magnetic switch detects the magnetism of the permanent magnet and turns on. Thus, it is detected that the float has reached the predetermined position. The contact member rotates in the opposite direction to the above as the float descends, and the movable member moves away from the magnetic switch as the contact member rotates. When the float falls below a predetermined high level, the distance between the magnetic switch and the permanent magnet becomes larger than a predetermined value, and the magnetic switch is turned off. That is, when the float is at a position lower than the predetermined high level, the magnetic switch is OFF.

JP 2013-24061 A

For example, when the above-described liquid pumping device is one in which high-temperature drain generated by vapor condensation flows in and is stored, the position detection sensor is exposed to high temperature. When the position detection sensor is used at a high temperature, the magnetic force (magnetism) of the permanent magnet gradually decreases. When the magnetic force of the permanent magnet decreases, the magnetic switch does not detect the magnetism of the permanent magnet even if the permanent magnet approaches the magnetic switch to a predetermined distance, and as a result, the position detection accuracy is impaired. there were.

The technology disclosed in the present application has been made in view of such circumstances, and its purpose is to suppress a decrease in position detection accuracy even when used at high temperatures in a position detection sensor using a magnetic switch. It is in.

In order to achieve the above object, the technology disclosed in the present application is provided with a permanent magnet in which a magnetic force acts on the permanent magnet separately from the permanent magnet detected by the magnetic switch.

Specifically, the position detection sensor of the present application includes a magnetic switch and a movable member. The movable member is attached with a first permanent magnet and directly or indirectly contacts an object, and moves toward the magnetic switch in accordance with the displacement of the object. The position detection sensor of the present application detects the magnetism of the first permanent magnet by detecting the magnetism of the first permanent magnet when the first permanent magnet approaches a predetermined distance set to the magnetic switch by the movement of the movable member. Detect the position of an object. Further, the position detection sensor of the present application includes a second permanent magnet provided in a region that always attracts or repels the first permanent magnet.

As described above, according to the position detection sensor of the present application, in addition to the first permanent magnet detected by the magnetic switch, the second permanent magnet that always attracts or repels the first permanent magnet is provided. That is, in the position detection sensor of the present application, the permanent magnet detected by the magnetic switch always forms a state of exerting a magnetic force with other magnets. Generally, a permanent magnet can maintain its own magnetic force by being in a state of exerting a magnetic force with other magnets. Therefore, even when the position detection sensor of the present application is used at a high temperature, it is possible to suppress the magnetic force (magnetism) of the first permanent magnet from being reduced, and it is possible to suppress a reduction in position detection accuracy. .

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a liquid pumping apparatus according to an embodiment. FIG. 2 is an enlarged cross-sectional view of the schematic configuration of the air supply valve and the exhaust valve. FIG. 3 is a cross-sectional view illustrating a schematic configuration of the position detection sensor according to the embodiment.

Hereinafter, embodiments of the present application will be described with reference to the drawings. Note that the following embodiments are essentially preferable examples, and are not intended to limit the scope of the technology disclosed in the present application, applications thereof, or uses thereof.

The liquid pumping apparatus 1 of this embodiment is provided in, for example, a steam system, and collects high-temperature drain (condensate) generated by steam condensation and pumps it to a boiler or a waste heat utilization apparatus. As shown in FIG. 1, the liquid pumping apparatus 1 includes a casing 10 that is a sealed container, an air supply valve 20 and an exhaust valve 30, a valve operating mechanism 40, and a position detection sensor 70 according to the claims of the present application. ing.

The casing 10 has a main body portion 11 and a lid portion 12 coupled by bolts, and a storage space 13 in which drain (liquid) flows and is stored is formed inside. A liquid inlet 14 through which drain flows, a liquid outlet 15 through which drain is discharged, a gas inlet 16 through which steam (working gas) is introduced, and steam (working gas) are discharged into the lid 12. Gas outlet 17 is provided. The liquid inflow port 14 is provided near the upper part of the lid part 12, and the liquid discharge port 15 is provided at the lower part of the lid part 12. Both the gas inlet 16 and the gas outlet 17 are provided in the upper part of the lid 12. These liquid inlets 14 and the like are all in communication with the storage space 13.

As shown in FIG. 2, the gas inlet 16 is provided with an air supply valve 20, and the gas outlet 17 is provided with an exhaust valve 30. The air supply valve 20 and the exhaust valve 30 open and close the gas inlet 16 and the gas outlet 17, respectively. The air supply valve 20 discharges the drain of the storage space 13 from the liquid discharge port 15 by introducing steam into the storage space 13 from the gas introduction port 16. The exhaust valve 30 discharges the steam introduced into the storage space 13 from the gas discharge port 17.

The air supply valve 20 has a valve case 21, a valve body 22, and a lifting rod 23. The valve case 21 has a through hole in the axial direction, and a valve seat 24 is formed above the through hole. An opening 25 through which the through hole communicates with the outside is formed in the middle portion of the valve case 21. The valve body 22 is formed in a spherical shape, and is integrally provided at the upper end of the lifting rod 23. The elevating rod 23 is inserted into the through hole of the valve case 21 so as to be movable up and down. When the elevating rod 23 is raised, the air supply valve 20 is separated from the valve seat 24 and the gas inlet 16 is opened. When the elevating rod 23 is lowered, the valve body 22 is seated on the valve seat 24 and gas is supplied. The inlet 16 is closed.

The exhaust valve 30 has a valve case 31, a valve body 32, and a lifting rod 33. The valve case 31 has a through hole in the axial direction, and a valve seat 34 is formed slightly above the through hole. The valve case 31 is formed with an opening 35 through which the through hole communicates with the outside. The valve body 32 is formed in a substantially hemispherical shape, and is provided integrally with the upper end of the elevating rod 33. The elevating rod 33 is inserted into the through hole of the valve case 31 so as to be movable up and down. When the elevating rod 33 is raised, the exhaust valve 30 is seated on the valve seat 34 and the gas discharge port 17 is closed. When the elevating rod 33 is lowered, the valve body 32 is separated from the valve seat 34 and the gas is exhausted. The outlet 17 is opened.

A valve operating rod 36 is connected to the lower end of the lifting rod 33 of the exhaust valve 30. That is, the raising / lowering rod 33 of the exhaust valve 30 moves up and down as the valve operation rod 36 moves up and down. The valve operating rod 36 is attached with a continuous plate 37 that extends to a region below the lifting rod 23 of the air supply valve 20. The raising / lowering rod 23 of the air supply valve 20 is pushed up by the connecting plate 37 when the valve operating rod 36 is raised, and rises. When the valve operating rod 36 is lowered, the connecting plate 37 is also lowered so that it is lowered by its own weight. That is, when the valve operating rod 36 is raised, the air supply valve 20 is opened (opens), while the exhaust valve 30 is closed (closed), and when the valve operating rod 36 is lowered, the air supply valve 20 is closed (closed). On the other hand, the exhaust valve 30 opens (opens).

The valve operating mechanism 40 is provided in the casing 10 and moves the valve operating rod 36 up and down to open and close the air supply valve 20 and the exhaust valve 30. The valve operating mechanism 40 includes a float 41 and a snap mechanism 50.

The float 41 is formed in a spherical shape and has a lever 42 attached thereto. The lever 42 is rotatably supported by a shaft 43 provided on the bracket 44. The lever 42 is provided with a shaft 45 at the end opposite to the float 41 side. The snap mechanism 50 includes a float arm 51, a sub arm 52, a coil spring 53, and two receiving members 54 and 55. One end of the float arm 51 is rotatably supported by a shaft 58 provided on the bracket 59. The

brackets

44 and 59 are coupled to each other by screws and attached to the lid portion 12. A groove 51a is formed at the other end of the float arm 51, and the shaft 45 of the lever 42 is fitted in the groove 51a. With this configuration, the float arm 51 swings about the shaft 58 as the float 41 moves up and down.

Further, the float arm 51 is provided with a shaft 56. The sub arm 52 has an upper end portion rotatably supported by a shaft 58 and a lower end portion provided with a shaft 57. The receiving member 54 is rotatably supported on the shaft 56 of the float arm 51, and the receiving member 55 is rotatably supported on the shaft 57 of the sub arm 52. A compressed coil spring 53 is attached between the receiving members 54 and 55. The sub arm 52 is provided with a shaft 61, and the lower end portion of the valve operating rod 36 is connected to the shaft 61.

The position detection sensor 70 is provided in the upper part of the main body 11 of the casing 10 and communicates with the storage space 13 to detect the position of the float 41 that is the object, and constitutes a magnetic sensor. As shown in FIG. 3, the position detection sensor 70 includes a case 71, a magnetic switch 72, a movable member 73, a contact member 78, and two permanent magnets 74 and 80 (a first permanent magnet 74 and a second permanent magnet). 80).

The case 71 is formed in a substantially columnar shape extending in the front-rear direction, the front side (one end side in the column axis direction) is located in the storage space 13 in the casing 10, and the rear side (the other end side in the column axis direction) is the casing 10. Located outside of. In the case 71, an insertion portion 71a of the movable member 73 is formed on the front side, and an accommodation portion 71b of the magnetic switch 72 is formed on the rear side. That is, the insertion part 71a and the accommodating part 71b are formed in the front and back. The insertion portion 71 a is an insertion hole extending rearward from the front end of the case 71 and is formed coaxially with the case 71. The insertion portion 71a and the accommodation portion 71b are partitioned by a partition wall 71c.

The magnetic switch 72 is fixed in the housing portion 71 b of the case 71. The movable member 73 is formed in a rod shape extending in the front-rear direction (the column axis direction of the case 71). The movable member 73 is inserted in the insertion part 71a of the case 71 so as to be movable (displaceable) in the front-rear direction. A first permanent magnet 74 is built in and attached to the movable member 73 on the inner end side (rear end side).

A forked piece 71d is formed at the front end of the case 71, and a rotating plate 75 is provided on the forked piece 71d. The rotating plate 75 is formed in a circular shape, and is rotatably attached to a central shaft 76 connected between the bifurcated pieces 71d. That is, the rotating plate 75 is rotatably supported by the case 71 via the central shaft 76. A bifurcated piece 73a is formed at the outer end (front end) of the movable member 73, and a connecting shaft 77 is connected between the bifurcated piece 73a. The connecting shaft 77 is provided through the outer edge of the rotating plate 75. That is, the rotating plate 75 is rotatably supported by the case 71 and the outer edge portion is connected to the movable member 73 via the connecting shaft 77.

The contact member 78 is a member that is formed in an elongated rod shape and is displaced in contact with the float 41. In the present embodiment, the contact member 78 is a coil spring. One end of the contact member 78 is fixed to the rotating plate 75 by press fitting, and the other end (tip) extends above the float 41. The contact member 78 is configured such that the tip is in contact with the float 41 and rotates (displaces) together with the rotating plate 75 as the float 41 moves up and down. As the rotating plate 75 rotates, the movable member 73 moves in the front-rear direction. That is, in the position detection sensor 70, the movable member 73 indirectly contacts the float 41 and moves in a direction approaching the magnetic switch 72 or moves away from the magnetic switch 72 as the float 41 is displaced. Is configured to do. When the first permanent magnet 74 approaches the magnetic switch 72 to a predetermined distance by the movement of the movable member 73, the position detection sensor 70 detects the magnetism of the first permanent magnet 74 and floats. The position 41 is configured to be detected.

Further, the position detection sensor 70 is provided with a second permanent magnet 80 different from the first permanent magnet 74. The second permanent magnet 80 is always provided in a region that attracts or repels the first permanent magnet 74. Specifically, the second permanent magnet 80 is attached to a lateral position of the first permanent magnet 74 on the outer peripheral surface of the case 71. In other words, in the position detection sensor 70, the first permanent magnet 74 detected by the magnetic switch 72 always forms a state in which the second permanent magnet 80 exerts a magnetic force. In addition, the second permanent magnet 80 is provided at a position where its own magnetism is not detected by the magnetic switch 72. That is, the second permanent magnet 80 is provided at a position where the magnetic force acts only on the first permanent magnet 74 among the magnetic switch 72 and the first permanent magnet 74.

<Operation of position detection sensor>
The valve operating mechanism 40 is displaced as the float 41 moves up and down, and moves the valve operating rod 36 up and down to open and close the air supply valve 20 and the exhaust valve 30. Specifically, in the liquid pumping apparatus 1, when the drain is not accumulated in the storage space 13, the float 41 is located at the bottom of the storage space 13 (state in FIG. 1). In this state, the valve operating rod 36 is lowered, the air supply valve 20 is closed, and the exhaust valve 30 is open. When drain is generated in the steam system, the drain flows from the liquid inlet 14 and accumulates in the storage space 13. As the drain accumulates in the storage space 13, the float 41 rises. In the storage space 13, the steam is discharged from the gas discharge port 17 as the drain accumulates.

After the float 41 rises and contacts the tip of the contact member 78, in the position detection sensor 70, the contact member 78 rotates counterclockwise in FIG. As the rotating plate 75 rotates, the movable member 73 moves rearward and approaches the magnetic switch 72. When the float 41 rises to the second predetermined high level, the first permanent magnet 74 approaches the magnetic switch 72 to a predetermined distance, and the magnetic switch 72 detects the magnetism of the first permanent magnet 74 and turns on. Thereby, it is detected that the float 41 has risen to the second predetermined high level. When the float 41 further rises and reaches the first predetermined high level (normally reverse high level), the valve operating rod 36 is raised by the snap mechanism 50. Thereby, the air supply valve 20 is opened and the exhaust valve 30 is closed.

When the air supply valve 20 is opened, steam (high-pressure steam) in the steam system flows from the gas inlet 16 and is introduced into the upper part of the storage space 13 (the upper space of the drain). Then, the drain accumulated in the storage space 13 is pushed downward by the pressure of the introduced steam and discharged from the liquid discharge port 15. That is, the drain of the storage space 13 is pumped. The drain pumped by the liquid pumping apparatus 1 is supplied to a boiler or a waste heat utilization apparatus. When the drain liquid level in the storage space 13 decreases due to the drainage, the float 41 descends. In the position detection sensor 70, as the float 41 descends, the contact member 78 and the rotating plate 75 rotate clockwise in FIG. 3 due to the weight of the contact member 78. As the rotating plate 75 rotates, the movable member 73 moves forward and moves away from the magnetic switch 72. When the float 41 descends below the second predetermined high level, the distance between the first permanent magnet 74 and the magnetic switch 72 becomes longer than the predetermined distance, and the magnetic switch 72 is turned off. Thereby, it is detected that the float 41 has fallen below the second predetermined high level.

Then, when the float 41 is lowered to a predetermined low level (normally reverse low level), the valve operating rod 36 is lowered by the snap mechanism 50, the air supply valve 20 is closed and the exhaust valve 30 is opened. As a result, drain flows from the liquid inlet 14 and accumulates in the storage space 13, and the vapor of the storage space 13 is discharged from the gas outlet 17. The above cycle is repeated. Then, by measuring the number of times the position detection sensor 70 is turned ON / OFF, the operating state of the liquid pressure feeding device 1 is grasped. Further, while the above cycle is repeated, in the position detection sensor 70, the first permanent magnet 74 and the second permanent magnet 80 are always in a state of exerting magnetic force with each other.

As described above, the position detection sensor 70 of the above embodiment includes the second permanent magnet 80 that always attracts or repels the first permanent magnet 74, in addition to the first permanent magnet 74 detected by the magnetic switch 72. I did it. That is, in the position detection sensor 70 of the above embodiment, the permanent magnet 74 detected by the magnetic switch 72 is always in a state of exerting a magnetic force with other magnets. Generally, a permanent magnet can maintain its own magnetic force by being in a state of exerting a magnetic force with other magnets. Therefore, the position detection sensor 70 of the above embodiment suppresses the magnetic force (magnetism) of the first permanent magnet 74 from being lowered even when the position detection sensor 70 is provided in the liquid pumping device 1 that stores high temperature drain and becomes high temperature. be able to. As a result, a decrease in position detection accuracy by the position detection sensor 70 can be suppressed.

Further, in the position detection sensor 70 of the above-described embodiment, the second permanent magnet 80 is provided at a side position of the first permanent magnet 74 on the outer peripheral surface of the case 71. As a result, it is possible to easily form a state in which the magnetic force (magnetism) of the second permanent magnet 80 does not affect the magnetic switch 72 but only the first permanent magnet 74. Therefore, it is possible to effectively suppress a decrease in position detection accuracy of the position detection sensor 70.

In addition, in the position detection sensor 70 of the said embodiment, you may make it provide the attachment position of the 2nd permanent magnet 80 in locations other than the position mentioned above. That is, the attachment position of the second permanent magnet 80 may be a position where the mutual magnetic force acts between the first permanent magnet 74 and the first permanent magnet 74 of the magnetic switch 72 and the first permanent magnet 74. It is more preferable that the position where the mutual magnetic force acts only between and.

In the position detection sensor 70 of the above-described embodiment, the movable member 73 is in contact with the object (float 41) indirectly. However, in the position detection sensor of the present application, the movable member is in direct contact with the object. It is good also as a structure which moves with a displacement.

In the above embodiment, the form in which the position detection sensor 70 is used in the liquid pumping apparatus 1 has been described. However, the position detection sensor of the present application is not limited to this, and may be used in other apparatuses and instruments. For example, the position detection sensor of the present application may be used for a drain tank in which the float rises and falls according to the drain water level.

The technology disclosed in the present application is useful for a position detection sensor that has a magnetic switch and detects the position of an object.

70 position detection sensor 71 case 72 magnetic switch 73 movable member 74 first permanent magnet 80 second permanent magnet

Claims

A magnetic switch;
A first permanent magnet is attached and is in direct or indirect contact with the object, and includes a movable member that moves toward the magnetic switch as the object is displaced;
A position where the magnetic switch detects the position of the object by detecting the magnetism of the first permanent magnet when the first permanent magnet approaches the magnetic switch to a predetermined distance by the movement of the movable member. A detection sensor,
A position detection sensor comprising a second permanent magnet provided in a region that always attracts or repels the first permanent magnet.
The position detection sensor according to claim 1,
It is formed in a substantially columnar shape and includes a case in which the magnetic switch is accommodated on one end side in the column axis direction and the movable member is inserted on the other end side in the column axis direction so as to be movable in the column axis direction.
The movable member is formed in a rod shape extending in the column axis direction of the case, and the first permanent magnet is built in the inner end side,
The position detection sensor, wherein the second permanent magnet is attached to a side position of the first permanent magnet on the outer peripheral surface of the case.