JP6730548B1 - Position detection sensor - Google Patents

Abstract

The position detection sensor 70 is moved by the rotation of the contact portion 80, and a rod-shaped contact portion 80 whose outer peripheral surface on the tip end side comes into contact with the object and which rotates with the displacement of the object around the base end side. The movable unit 73 and the magnetic switch 72 that detects the position of the object by detecting the presence of the movable unit 73 when the movable unit 73 approaches a predetermined distance due to the movement. The contact portion 80 has elasticity and is a cylindrical outer member 81 that constitutes the outer peripheral side of the contact portion 80, and a rod-shaped inner member 82 that is inserted inside the outer member 81 and has a greater elastic modulus than the outer member 81. And have.

Description

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

For example, as disclosed in Patent Document 1, a position detection sensor that detects the position of an object is known. In Patent Document 1, the position detection sensor is provided in the liquid pressure feeding device to detect the position of the float. In the liquid pumping device, the float rises and falls according to the liquid level of the liquid, the stored liquid is discharged when the float rises to a predetermined height, and a new liquid flows in and is stored when the float descends to a predetermined height. To be done.

The position detection sensor includes a magnetic switch that is a proximity switch, a movable portion (movable shaft) in which a permanent magnet is built, and a rod-shaped contact portion (coil spring) that contacts the float. In the position detection sensor, the tip side of the contact portion contacts the float and rotates as the float rises. With the rotation of the contact portion, the movable portion moves toward the magnetic switch. Then, when the float rises to a predetermined height 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. In this way, it is detected that the float has reached the predetermined position.

JP, 2013-24061, A

In the position detection sensor described above, for example, a coil spring is used as a member having elasticity capable of absorbing shock so that the contact part is not damaged by the shock when the float rises rapidly and contacts the contact part. There is. However, the coil spring may be displaced (slipped down) from the center of the spherical float due to deformation after coming into contact with the float, and in that case, the amount of rotation of the contact portion with respect to the rise of the float is reduced. Therefore, the position detection accuracy of the target object may be reduced.

The technique disclosed in the present application has been made in view of such circumstances, and an object thereof is to prevent damage to a contact portion due to an impact of an object while preventing a decrease in position detection accuracy.

The position detection sensor of the present application includes a rod-shaped contact portion, a movable portion, and a proximity switch. The contact portion has an outer peripheral surface on the distal end side contacting an object, and rotates around the base end side with displacement of the object. The movable part moves by the rotation of the contact part. The proximity switch detects the position of the target object by detecting the presence of the movable portion when the movable portion approaches a predetermined distance due to the movement. The contact portion has a tubular outer member and a rod-shaped inner member. The outer member has elasticity and constitutes the outer peripheral side of the contact portion. The inner member is inserted inside the outer member and has a larger elastic modulus than the outer member.

According to the position detection sensor of the present application, it is possible to prevent the contact portion from being damaged due to the impact of the object, and to prevent the position detection accuracy from being lowered.

FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid pumping device according to an embodiment. FIG. 2 is an enlarged cross-sectional view showing the schematic configurations of the air supply valve and the exhaust valve. FIG. 3 is a cross-sectional view showing a schematic configuration of the position detection sensor according to the embodiment. FIG. 4 is a cross-sectional view showing a schematic configuration of the contact portion according to the embodiment. FIG. 5 is a diagram for explaining the behavior of the contact portion.

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

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

In the casing 10, the main body 11 and the lid 12 are joined by bolts, and a storage space 13 in which a drain (liquid) flows and is stored is formed inside. The lid 12 has a liquid inlet 14 into which drain flows, a liquid outlet 15 from which drain drains, a gas inlet 16 into which steam (working gas) is introduced, and steam (working gas). And a gas discharge port 17 are provided. The liquid inlet 14 is provided near the top of the lid 12, and the liquid outlet 15 is provided below the lid 12. Both the gas inlet 16 and the gas outlet 17 are provided on the top of the lid 12. All of these liquid inflow ports 14 and the like communicate 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 causes the drain of the storage space 13 to be discharged from the liquid discharge port 15 by introducing steam into the storage space 13 from the gas introduction port 16. The exhaust valve 30 causes the steam introduced into the storage space 13 to be discharged 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 is formed in the middle of the valve case 21 so that the through hole communicates with the outside. The valve body 22 is formed in a spherical shape and is integrally provided on the upper end of the elevating rod 23. The lifting rod 23 is vertically movably inserted into the through hole of the valve case 21. In the air supply valve 20, when the elevating rod 23 rises, the valve body 22 separates from the valve seat 24 to open the gas inlet 16, and when the elevating rod 23 descends, the valve body 22 sits on the valve seat 24 and gas. 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 that communicates the through hole with the outside. The valve element 32 is formed in a substantially hemispherical shape, and is integrally provided on the upper end of the elevating rod 33. The elevating rod 33 is vertically movably inserted into the through hole of the valve case 31. In the exhaust valve 30, when the elevating rod 33 rises, the valve body 32 is seated on the valve seat 34 and the gas outlet 17 is closed, and when the elevating rod 33 descends, the valve body 32 separates 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 elevating rod 33 of the exhaust valve 30. That is, the elevating rod 33 of the exhaust valve 30 moves up and down as the valve operating rod 36 moves up and down. Further, the valve operating rod 36 is provided with a continuous plate 37 extending to a region below the elevating rod 23 of the air supply valve 20. The elevating rod 23 of the air supply valve 20 is pushed up by the connecting plate 37 when the valve operating rod 36 rises, and descends by its own weight because the connecting plate 37 also descends when the valve operating rod 36 descends. That is, when the valve operating rod 36 rises, the air supply valve 20 opens (opens), while the exhaust valve 30 closes (closes), and when the valve operating rod 36 descends, the air supply valve 20 closes (closes). 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 actuation mechanism 40 has 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 a bracket 44. The lever 42 is provided with a shaft 45 at the end portion on the side 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 a bracket 59. The brackets 44 and 59 are connected to each other by screws and attached to the lid 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 around 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 rotatably supported by a shaft 58 and a lower end provided with a shaft 57. The receiving member 54 is rotatably supported by the shaft 56 of the float arm 51, and the receiving member 55 is rotatably supported by the shaft 57 of the sub arm 52. A coil spring 53 in a compressed state is attached between the receiving members 54 and 55. Further, 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.

<Structure of position detection sensor>
The position detection sensor 70 is provided above the main body 11 of the casing 10, communicates with the storage space 13, and detects the position of the float 41 that is the object. The position detection sensor 70 constitutes a magnetic sensor.

As shown in FIG. 3, the position detection sensor 70 includes a case 71, a magnetic switch 72, a movable portion 73, and a contact portion 80.

The case 71 is formed in a substantially columnar shape extending in the front-rear direction. The case 71 has a front side (one end side in the column axis direction) located in the storage space 13 inside the casing 10, and a rear side (the other end side in the column axis direction) located outside the casing 10. In the case 71, the insertion portion 71a of the movable portion 73 is formed on the front side, and the housing portion 71b of the magnetic switch 72 is formed on the rear side.

That is, the insertion portion 71a and the housing portion 71b are formed in front of each other. The insertion portion 71 a is an insertion hole that extends 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 71b of the case 71. The magnetic switch 72 corresponds to the proximity switch according to the claims of the present application.

The movable portion 73 is a rod-shaped member extending in the front-rear direction (column axis direction of the case 71). The movable portion 73 is inserted in the insertion portion 71a of the case 71 so as to be movable (displaceable) in the front-rear direction. A magnet 74 is built in and attached to the movable portion 73 on the inner end side (rear end side). The magnet 74 is a permanent magnet.

A forked piece 71d is formed at the front end of the case 71, and a rotary plate 75 is provided on the forked piece 71d. The rotary plate 75 is formed in a circular shape and is rotatably attached to a central shaft 76 connected between the forked pieces 71d. That is, the rotating plate 75 is rotatably supported by the case 71 via the central shaft 76.

A forked piece 73a is formed at the outer end (front end) of the movable portion 73, and a connecting shaft 77 is connected between the forked piece 73a. The connecting shaft 77 is provided so as to penetrate the outer edge portion 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 portion 73 via the connecting shaft 77.

The contact portion 80 is formed in an elongated rod shape. The contact portion 80 has a base end side (an end portion on the left side in FIG. 3) fixed to the rotary plate 75, and a tip end side (an end portion on the right side in FIG. 3) extends above the float 41. The contact portion 80 is configured such that the outer peripheral surface on the distal end side comes into contact with the float 41 and rotates about the base end side as the float 41 is displaced. That is, the contact portion 80 contacts the float 41 and rotates together with the rotating plate 75 as the float 41 moves up and down.

The movable portion 73 moves in the front-rear direction by the rotation of the contact portion 80. That is, in the position detection sensor 70, the movable portion 73 indirectly contacts the float 41 and moves (towards) the magnetic switch 72 in accordance with the displacement of the float 41 or moves away from the magnetic switch 72. It is configured to move.

Then, the magnetic switch 72 is configured to detect the presence of the movable portion 73 and detect the position of the float 41 when the movable portion 73 moves to a predetermined distance that is set in advance. That is, the magnetic switch 72 detects the presence of the movable portion 73 by detecting the magnetism of the magnet 74 built in the movable portion 73.

As shown in FIG. 4, the contact portion 80 has an outer member 81, an inner member 82, and an annular member 83. Note that, in FIG. 3, the base end side of the contact portion 80 is schematically illustrated, and the illustration of the inner member 82 and the annular member 83 is omitted.

The outer member 81 is a tubular (specifically, substantially cylindrical) member that has elasticity and constitutes the outer peripheral side of the contact portion 80. That is, the outer member 81 is an elongated rod-shaped member, and the outer peripheral surface on the side of the tip 81b contacts the float 41. The outer member 81 is a metal coil spring, more specifically, a close contact coil spring.

The outer member 81 is configured to be elastically deformable when it contacts the float 41. The outer member 81 has elasticity capable of absorbing the shock so that the float 41 does not become damaged by the shock when the float 41 rapidly rises and comes into contact with the float 41. More specifically, the outer member 81 has elasticity such that the upper part and the lower part thereof are elastically deformed in the directions of thick arrows shown in FIG. In other words, the outer member 81 has elasticity allowing elastic deformation capable of absorbing the shock of the float 41. By elastically deforming the outer member 81 in this way, the outer member 81 absorbs the impact of the float 41. The deformation directions of the upper part and the lower part of the outer member 81 may be opposite to the directions shown in FIG.

The inner member 82 is a rod-shaped member that is inserted inside the outer member 81 and has a larger elastic modulus than the outer member 81. The inner member 82 is a circular rod-shaped member and is provided coaxially with the outer member 81. The inner member 82 is inserted over the entire length of the outer member 81 from the base end 81a to the tip 81b. More specifically, the inner member 82 has a base end 82a protruding from the base end 81a of the outer member 81, and a tip 82b flush with the tip 81b of the outer member 81.

Since the inner member 82 has a larger elastic modulus than the outer member 81, the inner member 82 is less flexible (harder to bend) than the outer member 81. After the contact portion 80 (outer member 81) contacts the float 41, the inner member 82 prevents the contact portion 80 (outer member 81) from being displaced from the center of the float 41 (sliding down) due to deformation. The elastic modulus is large enough to suppress the deformation (deflection) of the. In other words, the elastic modulus of the inner member 82 is such that the contact portion 80 (outer member 81) does not bend near the center of the float 41 so that the contact portion 80 (outer member 81) does not bend, for example, as shown by the chain double-dashed line in FIG. It has a size that can be suppressed. Note that FIG. 5 is a view as seen from above the float 41.

The inner member 82 is formed of, for example, a stainless steel wire for spring. As the spring stainless steel wire, for example, JIS G 4314 SUS304-WPB or SUS316-WPA is used.

The inner member 82 is inserted with a predetermined gap δ between the outer member 81 and ((inner diameter D of outer member 81-outer diameter d of inner member 82)/2) (see FIG. 4 ). By providing such a gap δ, it is possible to deform the outer member 81 described above (the upper and lower portions of the outer member 81 are displaced in the direction of the thick arrow shown in FIG. 4). The gap δ is set to a size that can secure the required amount of deformation of the outer member 81.

The annular member 83 is an annular plate member. The annular member 83 is provided coaxially with the outer member 81 on the end surface of the outer member 81 on the base end 81a side. The inner diameter of the annular member 83 is formed to be substantially the same as the outer diameter d of the inner member 82, and the proximal end 82a side of the inner member 82 penetrates.

A base end 82a of the inner member 82, which is located outside the annular member 83, is bent in an L shape. The inner member 82 is prevented from coming out of the outer member 81 by the bent base end 82a coming into contact with the annular member 83. The outer member 81 has its base end 81a side hooked on the projection 84 provided on the rotary plate 75, and thereby, it is prevented from coming out of the rotary plate 75.

<Operation of position detection sensor>
The valve actuating 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 device 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 of 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 drainage is generated in the steam system, the drainage flows in from the liquid inflow port 14 and is accumulated in the storage space 13. The float 41 rises as the drain accumulates in the storage space 13. In addition, in the storage space 13, steam is discharged from the gas discharge port 17 as the drain accumulates.

After the float 41 rises and comes into contact with the outer peripheral surface on the tip side of the contact portion 80, in the position detection sensor 70, the contact portion 80 rotates counterclockwise in FIG. 3 along with the rotation plate 75 as the float 41 rises. Here, when the float 41 rapidly rises and comes into contact with the contact portion 80, the outer member 81 is deformed in the direction of the thick arrow in FIG. 4 to absorb the shock of the float 41. Therefore, the contact portion 80 is prevented from being damaged by the impact of the float 41.

With the rotation of the rotary plate 75, the movable portion 73 moves backward and approaches the magnetic switch 72. Then, when the float 41 moves up to the second predetermined high position, the magnet 74 approaches the magnetic switch 72 by a predetermined distance, and the magnetic switch 72 detects the magnetism of the magnet 74 and turns on. As a result, it is detected that the float 41 has risen to the second predetermined high level. Here, since the inner member 82 has the above-mentioned predetermined elastic modulus, when the float 41 rises, the contact portion 80 bends and shifts from the center of the float 41 as shown by the chain double-dashed line in FIG. There is no. Therefore, after the float 41 contacts the contact portion 80, the contact portion 80 can be rotated as the float 41 moves up.

When the float 41 further rises and reaches the first predetermined high position (normal reversal high position), the snap mechanism 50 causes the valve operating rod 36 to move up. As a result, the air supply valve 20 is opened and the exhaust valve 30 is closed. When the air supply valve 20 opens, the steam (high-pressure steam) in the steam system flows in from the gas introduction port 16 and is introduced into the upper part of the storage space 13 (the space above 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 pressure-fed by the liquid pressure-feeding device 1 is supplied to the boiler and the waste heat utilization device. When the drain liquid level in the storage space 13 decreases due to drainage, the float 41 descends.

In the position detection sensor 70, as the float 41 descends, the contact portion 80 and the rotating plate 75 rotate clockwise in FIG. 3 due to the weight of the contact portion 80. With the rotation of the rotary plate 75, the movable portion 73 moves forward and moves away from the magnetic switch 72. When the float 41 descends below the second predetermined high position, the distance between the magnet 74 and the magnetic switch 72 becomes longer than the predetermined distance, and the magnetic switch 72 is turned off. As a result, it is detected that the float 41 has descended below the second predetermined high position.

Then, when the float 41 descends to a predetermined lower position (normally inversion lower position), the valve operating rod 36 descends by the snap mechanism 50, the air supply valve 20 closes, and the exhaust valve 30 opens. As a result, the drain flows from the liquid inflow port 14 and collects in the storage space 13, and the vapor in the storage space 13 is discharged from the gas discharge port 17. The above cycle is repeated. Then, by measuring the number of times the position detection sensor 70 is turned ON/OFF, the operating condition of the liquid pressure feeding device 1 can be grasped.

As described above, the position detection sensor 70 of the above embodiment includes the rod-shaped contact portion 80, the movable portion 73, and the magnetic switch 72 (proximity switch). The outer peripheral surface of the contact portion 80 on the tip side contacts the float 41 (object), and rotates with the displacement of the float 41 about the base end side. The movable portion 73 moves by the rotation of the contact portion 80. The magnetic switch 72 detects the presence of the movable portion 73 and detects the position of the object when the movable portion 73 moves to a predetermined distance. The contact portion 80 has a tubular outer member 81 and a rod-shaped inner member 82. The outer member 81 has elasticity and constitutes the outer peripheral side of the contact portion 80. The inner member 82 is inserted inside the outer member 81 and has a larger elastic modulus than the outer member 81.

According to the above configuration, when the float 41 suddenly contacts the contact portion 80, the outer member 81 is elastically deformed and the shock of the float 41 is absorbed. Therefore, it is possible to prevent the contact portion 80 from being damaged by the impact of the float 41 (object). Further, since the elastic modulus of the inner member 82 is larger than that of the outer member 81, after the contact portion 80 (outer member 81) comes into contact with the float 41, the contact portion 80 may be displaced (slipped down) from the center of the float 41 due to deformation. Can be stopped. Therefore, the contact portion 80 can be reliably rotated as the float 41 moves up. This can prevent a decrease in position detection accuracy. As described above, according to the above configuration, it is possible to prevent the contact portion 80 from being damaged by the impact of the target object, and at the same time, to prevent the position detection accuracy from decreasing.

In the position detection sensor 70 of the above embodiment, the inner member 82 is inserted with the outer member 81 with a predetermined gap δ. According to this configuration, the outer member 81 can be easily elastically deformed when the float 41 comes into contact, and a necessary amount of deformation can be easily secured. Therefore, it is possible to reliably prevent the contact portion 80 from being damaged by the impact of the object.

Further, in the position detection sensor 70 of the above embodiment, the outer member 81 is a metal coil spring. According to this, the durability of the outer member 81 can be improved as compared with the case where the outer member is made of rubber, for example. In particular, the position detection sensor 70 provided in the high temperature storage space 13 as in the above embodiment is effective.

Further, since the predetermined gap δ is provided between the outer member 81 and the inner member 82, when the float 41 contacts the outer peripheral surface of the coil spring (outer member 81), the coil spring is indicated by a thick arrow in FIG. Can be elastically deformed in any direction.

Further, in the position detection sensor 70 of the above-described embodiment, the contact portion 80 is provided coaxially with the outer member 81 on the end face of the outer member 81 on the base end 81a side, and the inner diameter is substantially the same as the outer diameter d of the inner member 82. And an annular member 83 formed on the base member 82a side of the inner member 82. With this configuration, the predetermined gap δ can be easily and reliably provided between the outer member 81 and the inner member 82.

In addition, in the position detection sensor 70 of the above-described embodiment, the inner member 82 has a base end 82a that is more outward than the annular member 83. According to this configuration, it is possible to prevent the inner member 82 from coming off the outer member 81 by the bent base end 82 a being caught by the annular member 83.

In addition, in the position detection sensor 70 of the above embodiment, the predetermined gap δ is provided between the outer member 81 and the inner member 82, but the position detection sensor of the present application, the outer member and the inner member. The gap may not be provided substantially. In that case, it is preferable to use a tubular rubber body or metal body having a predetermined elasticity other than the coil spring as the outer member.

Further, in the position detection sensor 70 of the above-described embodiment, the magnetic type switch (magnetic switch 72) is used as the proximity switch, but, for example, an inductive type, a capacitance type, an ultrasonic type, a photoelectric type proximity switch, You may use it.

Further, in the position detection sensor 70 of the above-described embodiment, the material of the inner member 82 is not limited to the above.

In the above embodiment, the position detection sensor 70 is used in the liquid pressure feeding device 1. However, the position detection sensor of the present application is not limited to this, and may be used in other devices or 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 technique disclosed in the present application is useful for a position detection sensor that detects the position of an object.

70 Position detection sensor 72 Magnetic switch (proximity switch)
73 movable part 80 contact part 81 outer member 81a base end 81b tip 82 inner member 82a base end 83 annular member δ gap

Claims (5)

A rod-shaped contact portion whose outer peripheral surface on the distal end side comes into contact with an object and rotates around the base end side with displacement of the object;
A movable part that moves by rotation of the contact part;
A proximity switch that detects the position of the object by detecting the presence of the movable portion when the movable portion approaches a predetermined distance due to movement,
The contact portion is
A cylindrical outer member having elasticity and constituting the outer peripheral side of the contact portion,
A position detection sensor having a rod-shaped inner member that is inserted inside the outer member and has a larger elastic modulus than the outer member. The position detection sensor according to claim 1,
The position detecting sensor, wherein the inner member is inserted with a predetermined gap from the outer member. The position detection sensor according to claim 2,
The position detecting sensor, wherein the outer member is a coil spring. The position detection sensor according to claim 2,
The contact portion is provided coaxially with the outer member on the end face on the base end side of the outer member, has an inner diameter substantially equal to the outer diameter of the inner member, and has an annular shape through which the base end side of the inner member passes. A position detection sensor having a member. The position detection sensor according to claim 4,
The position detection sensor, wherein the inner member has a base end that is bent outwardly of the annular member.

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