JP6651078B1 - Float type level meter - Google Patents

Abstract

An object of the present invention is to provide a float type level meter which is easy to maintain. A tubular guide member, a support member provided inside the guide member and extending in the axial direction of the guide member, a floating member movable in the axial direction of the guide member, and a floating member. A switch 6 which is operated by the magnetic force of an opening / closing magnet 10b provided on the liquid crystal 10; the floating member 10 moves with the displacement of the liquid level, and the level of the liquid level is detected by operating the switch 6; In total, the switch 6 is provided at a detection switch 6a connected to a position where the floating member 10 of the support member 5 operates when the floating member 10 moves, and at a position where the switch 6 does not operate even when the floating member 10 moves. And a backup switch 6b. [Selection diagram] Fig. 1

Description

  The present invention relates to a float type level meter.

  Conventionally, as a means for detecting the internal volume of a fluid stored in a tank, a float type level meter using a float has been used. The float type level meter adopts a structure in which the float moves up and down with the displacement of the liquid surface of the fluid, and a switch is operated by the magnetic force of a magnet provided on the float to detect the position of the liquid surface. As such a float type level meter, Patent Document 1 discloses a liquid level sensor including a tubular member, a float having a magnet, a reed switch (switch), and a printed circuit board to which the reed switch is connected. (Float type level meter) is disclosed.

JP-A-2002-81988

  In a float type level meter, the contact of a switch opens and closes as the float moves up and down, and detects the position of the liquid level. For this reason, in the float type level meter, a failure occurs at the contact portion of the switch due to aging. In the case of a float type level meter having a plurality of switches, the frequency of occurrence of a switch failure increases. Therefore, in the float type level meter, a switch in which a fault has occurred or a switch whose expiration date has passed has been replaced with a new switch. Maintenance occurs regularly. In the float type level meter, switches having different wiring lengths according to the measurement range are used. For this reason, when using a plurality of float level meters having different measurement ranges, the administrator needs to store switches having various wiring lengths for each wiring length. In addition, float level meters require the use of tools to remove and insert the switch. For this reason, the switch replacement work may be complicated because a switch having a wiring length suitable for the measurement range is selected and the switch is attached and detached using a tool.

  The present invention has been made in view of the above situation, and has as its object to provide a float type level meter that is easy to maintain.

  That is, the first invention is a tubular guide member, a support member provided inside the guide member and extending in the axial direction of the guide member, a floating member movable in the axial direction of the guide member, A self-holding switch that is operated by the magnetic force of a magnet provided on the floating member, wherein the floating member moves with the displacement of the liquid surface, and the switch is operated to detect the position of the liquid surface. A float type level meter, wherein the switch is provided at a position where the floating member of the support member is operated by the movement of the floating member, and a switch for detection is provided at a position where the floating member does not operate even if the floating member moves. And a spare switch provided.

  According to a second aspect of the invention, there is provided a connection member including a connection portion connected to the support member and a holding portion for holding the switch.

  In a third aspect, the connection member is configured such that the support member is detachably attached to the connection portion in a state where the switch is held by the holding portion.

  In a fourth aspect, the connection member is configured such that the switch can be attached to and detached from the holding portion in a state where the support member is connected to the connection portion.

  According to a fifth aspect of the present invention, the connection member has a connection portion protruding from one end and the other end than both ends of the switch in the axial direction of the support member, and the connection portion and the support member are detachable. What is connected.

  In a sixth aspect, the switch has a switch main body and a wiring, and a part of the wiring and the switch main body are molded with resin.

  In a seventh aspect, the guide member and the support member each have an extending portion extending to at least one of one side and the other side of the movement range of the floating member. It is connected to the extension of the support member.

  An eighth invention is a tubular guide member, a support member provided inside the guide member and extending in the axial direction of the guide member, a floating member movable in the axial direction of the guide member, and the floating member A self-holding switch that operates when receiving a magnetic force equal to or more than a predetermined value from a magnet provided in the floating member, wherein the floating member moves with the displacement of the liquid level, and the switch operates. A float-type level meter that detects the position of the liquid level at the switch, wherein the switch is connected to the support member and operates as a detection switch that operates when the floating member moves, and a magnetic force equal to or greater than the predetermined value. And a spare switch covered with a shielding material for blocking.

  The present invention has the following effects.

  In the first invention, there is no need to separately store a spare switch according to the size of the float type level meter. In addition, since the spare switch does not operate even if the floating member moves, the contact does not open and close even when the float type level meter is used. Therefore, when the detection switch breaks down, the float type level meter can use the spare switch as an unused switch. Therefore, the float type level meter does not require a step of preparing a replacement switch, and facilitates maintenance.

  In the second invention, the switch is connected to the support member via the connection member. As a result, the float type level meter does not need to directly attach the switch to the support member, so that maintenance becomes easy. In addition, the connection member may be detached from the switch while being attached to the support member, or may be detached from the support member while being attached to the switch. This allows the float type level meter to easily attach and detach the failed detection switch in a manner according to the situation, thereby facilitating maintenance.

  In the third invention, the switch is provided with a connection member for connecting to the support member in advance. For this reason, the float type level meter does not require a step of attaching a connection member to the switch, and thus facilitates maintenance.

  In the fourth invention, a connection member for connecting the detection switch is provided at a predetermined position of the support member. Accordingly, even when the faulty detection switch is removed, the float-type level meter has a clear position where the spare switch is to be attached, thereby facilitating maintenance.

  In the fifth invention, the switch is fixed to the support member at a position shifted from the switch main body in the axial direction of the support member. Thus, the float type level meter can easily maintain the switch because the switch can be directly connected to the support member.

  In the sixth aspect, the switch is prevented from being deteriorated due to oxidation of the switch main body and the wiring, so that the durability of the contact portion of the switch is improved. Thereby, in the float type level meter, the frequency of failure of the detection switch and the spare switch is suppressed, so that maintenance becomes easy.

  In the seventh invention, the spare switch is arranged at a position of the support member that does not open and close due to the magnetic force of the floating member. Therefore, the float type level meter can replace a failed switch with a spare switch having the same durability as an unused switch, thereby facilitating maintenance.

  In the eighth invention, the spare switch is covered with a shielding material so as not to receive a magnetic force. Therefore, in the float type level meter, the spare switch does not operate even if the float passes through the spare switch. Therefore, in the float type level meter, any number of spare switches having the same durability as unused switches can be arranged at an arbitrary position in the guide member including the float moving range. Thereby, in the float type level meter, the spare switch can be arranged in the vicinity of each switch, so that the replacement work of the switch becomes easy and the maintenance becomes easy.

It is a schematic diagram showing the composition of one embodiment of a level meter. FIG. 3 is a diagram illustrating a schematic configuration of a switch. FIG. 3 is a diagram illustrating an arrangement of a backup switch according to the first embodiment. FIG. 4 shows an operation mode of the self-holding type switch. (A) shows a switch in an open state, (B) shows a switch in a closed state by an open / close magnet, (C) shows a switch in which a closed state is maintained, and (D) shows a switch from a closed state to an open state. The switch that has become. FIG. 2A is a side view illustrating a connection structure between a switch and a support member according to the first embodiment. (B) is an arrow A view of (A). (A) is a side view which shows the connection structure of the switch and support member which concerns on the modification 1 of Embodiment 1. FIG. (B) is an arrow A view of (A). FIG. 9 is a diagram illustrating a state in which a switch according to a first modification of the first embodiment is attached to and detached from a support member. (A) is the figure seen from the side. (B) is a diagram viewed from above. (A) is a side view which shows the connection structure of the switch and the support member which concerns on the modification 2 of Embodiment 1. FIG. (B) is an arrow A view of (A). FIG. 9 is a diagram illustrating a state in which a switch according to a second modification of the first embodiment is attached to and detached from a support member. (A) is the figure seen from the side. (B) is a diagram viewed from above. (A) is a side view which shows the connection structure of the switch and support member which concerns on the other modification of Embodiment 1. FIG. (B) is an arrow A view of (A). FIG. 9 is a diagram illustrating an example of an arrangement of a backup switch according to a second embodiment. (A) is a longitudinal sectional view. (B) is a view on arrow A of (A). FIG. 9 is a diagram illustrating a schematic configuration of a backup switch according to a third embodiment. FIG. 13 is a diagram illustrating an example of an arrangement of a backup switch according to a third embodiment.

(Embodiment 1)
(overall structure)
First, a level meter 1 which is a float type level meter according to a first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the level meter 1 is configured to detect the lowermost position, the lowermost position, the uppermost position, and the uppermost position in order from the lower side as the detection position.

  As shown in FIG. 1, the level meter 1 is a device that detects a liquid level position of a fluid L (a liquid or a mixture of a liquid and a gas) stored in a container C. The level meter 1 is provided on an upper pedestal Ca of a container C in which a fluid L is stored. The level meter 1 includes a guide member 2, a terminal block 3, a support member 5, a switch 6, a fixing member 9, a floating member 10, and a detection device 11.

  The guide member 2 is a member that guides the floating member 10. The guide member 2 is formed of a metal having high corrosion resistance such as stainless steel. The guide member 2 is formed from a hollow tubular member. The guide member 2 has one end opened and the other end closed. At one end (opening side) of the guide member 2, a mounting flange 2a is provided. The guide member 2 is fixed to the upper gantry Ca of the container C via a flange. The guide member 2 is arranged so as to extend toward the inside of the container C. That is, the guide member 2 is disposed so as to be immersed in the fluid L stored in the container C. The guide member 2 is formed to have a length corresponding to the liquid level detection position. At the other end (closed side) of the guide member 2, a retaining member 2b is provided so that the floating member 10 does not move to the closed side from the lowermost position. In the present embodiment, the guide member 2 has a length that extends a predetermined length toward the closed side of the guide member 2 from the lowermost position.

  The terminal block 3 is a table that connects the input side wiring and the output side wiring. The terminal block 3 is fixed to a mounting flange 2 a of the guide member 2. The terminal block 3 is provided with conductive input-side terminals and output-side terminals on a base made of an insulating material such as ceramic. The wiring 62 of the switch 6 is detachably connected to the input terminal. A wiring 11a from the detection device 11 is detachably connected to the output side terminal.

  The input-side terminal includes a plurality of input-side terminals 3a to which wirings 62 from a plurality of detection switches 6 (detection switches 6a) for detecting the liquid level are connected, and at least one at least one that does not detect the liquid level. An input terminal 3b to which a wiring 62 from the standby switch 6 (standby switch 6b) is connected is provided. The plurality of input terminals 3a to which the wiring 62 from the detection switch 6a is connected are electrically connected to the output terminals to which the wiring 11a from the detection device 11 is connected. The input terminal 3b to which the wiring 62 from the spare switch 6b is connected is not electrically connected to the output terminal. The spare switch 6b may be configured so as not to detect the liquid level, and may be configured to be electrically connected to the wiring 11a.

  The support member 5 is a member that supports the switch 6. The support member 5 is composed of a rod-shaped member made of metal such as stainless steel or resin. The support member 5 has the same length as the guide member 2. The support member 5 is provided inside the guide member 2 and extends in the axial direction of the guide member 2. Therefore, like the guide member 2, the support member 5 extends a predetermined length toward the closed side of the guide member 2 from the lowermost position where the floating member 10 moves. A portion extending from the lowermost position toward the closing side of the guide member 2 is referred to as an extension 5a.

  The support member 5 is located inside the guide member 2 and is fixed by a fixing member 9.

  As shown in FIG. 2, the switch 6 is a self-holding type reed switch that opens and closes with a magnetic force. The switch 6 has a switch main body 61, a wiring 62, a glass tube 63, and a molded part 64.

  The switch body 61 has lead pieces 61a and 61b and a bias magnet 61c. The switch 6 allows the contact 61d of one lead 61a and the contact 61e of the other lead 61b to contact or separate from each other by the magnetic force of the bias magnet 61c and the opening / closing magnet 10b (magnet) of the floating member 10 described later. To open and close (turn on and off). The detailed operation principle of the switch 6 will be described later.

  Wiring 62 is connected to each of the lead pieces 61a and 61b. The tip of the wiring 62 is detachably connected to the input terminal of the terminal block 3.

  The switch body 61 and a part of the wiring 62 are provided inside the glass tube 63. That is, the switch body 61 is configured such that the lead pieces 61a and 61b open and close in the internal space of the glass tube 63. Further, the switch body 61, a part of the wiring 62, and the glass tube 63 are molded with silicone resin. The switch 6 is formed in a column shape extending in the axial direction of the support member 5 as a whole. By molding the switch body 61, a part of the wiring 62, and the glass tube 63 with resin, entry of moisture such as moisture and oxygen from the opening of the glass tube 63 is prevented. Thus, the switch 6 can suppress the deterioration of the switch body 61 and the wiring 62 due to oxidation. The switch 6 improves the durability of the contacts 61d and 61e, so that the frequency at which the switch 6 breaks down can be suppressed. Hereinafter, the part for molding the switch body 61, a part of the wiring 62, and the glass tube 63 will be referred to as a molded part 64 for description.

  As shown in FIG. 1, the switch 6 includes a detection switch 6a for detecting a lowermost position, a lower limit position, an upper limit position, and an uppermost position of the liquid surface, and at least one spare switch which can be replaced with the detection switch. Switch 6b. In the present embodiment, four detection switches 6 a are connected to the support member 5. The four detection switches 6a are installed at the lowermost position, lower limit position, upper limit position, and uppermost position of the liquid surface of the fluid L in order from the lower side. Detect the position.

  As shown in FIG. 3, in the present embodiment, the spare switch 6 b is connected to the extension 5 a of the support member 5. That is, in the present embodiment, the spare switch 6b is arranged at a position where it does not operate due to the magnetic force from the floating member 10 even when the floating member 10 moves to the lowermost position. In FIG. 3, the magnetic flux of the opening and closing magnet 10b is indicated by a broken line. As shown in FIG. 3, the magnetic force from the opening / closing magnet 10b reaches the detection switch 6a provided at the position of the support member 5 within the movement range of the floating member 10. On the other hand, the magnetic force from the opening / closing magnet 10b does not reach the spare switch 6b provided on the extending portion 5a of the support member 5 outside the moving range of the floating member 10. Therefore, the spare switch 6b provided in the extension portion 5a does not operate even if the floating member 10 moves.

  As described above, the level meter 1 includes, in addition to the plurality of detection switches 6a, the spare switch 6b that can be replaced with the detection switch 6a of the level meter 1. Therefore, in the level meter 1, there is no need to separately store the spare switch 6b for maintenance of the detection switch. Further, since the spare switch 6b is disposed in the extension portion 5a where the magnetic force does not act even when the floating member 10 is located at any position in the movable range, deterioration due to opening and closing of the contacts 61d and 61e does not occur. Therefore, when the detection switch 6a fails or the like, the level meter 1 can use the spare switch 6b as an unused switch.

  The detection switch 6a and the spare switch 6b have the same structure. Therefore, hereinafter, when it is necessary to distinguish the detection switch 6a and the spare switch 6b, they are referred to as the detection switch 6a and the spare switch 6b, but when there is no need to distinguish them, they are simply referred to as the switch 6. .

  The switch 6 and the support member 5 are connected via a connection member. The connection member is fixed to one of the switch 6 and the support member 5, and is connected to the other in such a manner that it can be easily attached and detached and can maintain its position with respect to the support member 5 in the axial direction. That is, the connection member is detached from the support member 5 while the switch 6 is detached from the connection member while being connected to the support member 5. The details of the connection structure between the switch 6 and the support member 5 will be described later.

  The fixing member 9 is a member that fixes the support member 5 to the guide member 2. The fixing member 9 is formed in a shape that can be pressed into the guide member 2 from one end side (opening side). The fixing member 9 is formed with a mounting hole into which the support member 5 can be pressed and a wiring hole through which the wiring 62 from the switch 6 passes. The support member 5 is press-fitted into the mounting hole of the fixing member 9. That is, the fixing member 9 is attached to the support member 5. The wiring 62 of the switch 6 is passed through the wiring hole of the fixing member 9.

  The floating member 10 is a member that moves the opening / closing magnet 10b according to the position of the liquid surface. The floating member 10 is formed of a material having a density lower than the density of the fluid L so as to float on or in the liquid surface of the fluid L, or is formed in a hollow shape in which buoyancy is generated with respect to the fluid L. The floating member 10 is formed with a guide hole 10a into which the guide member 2 can be inserted and is movable. In the floating member 10, the guide member 2 is inserted into the guide hole 10a. Thereby, the floating member 10 is configured to be movable in the axial direction of the guide member 2 along the guide member 2.

  The floating member 10 is provided with an opening and closing magnet 10 b for opening and closing the switch 6. When the opening / closing magnet 10b enters the impressed area of the switch 6, the switch 6 in the open state is switched to the closed state and the switch 6 in the closed state is switched to the open state in accordance with the entering direction. Thus, the floating member 10 is configured to open and close the switch 6 by the magnetic force of the opening / closing magnet 10b when the level of the fluid L is in the sensitive region of the switch 6.

  The detection device 11 is a device that detects the open / closed state of the switch 6. In the detection device 11, a wiring 11 a configured to be independent for each detection switch 6 a is connected to the terminal block 3. The detection device 11 is configured to independently apply a voltage to the wiring 11a for each detection switch 6a. That is, in the detection device 11, an independent detection circuit is configured for each detection switch 6a. The detection device 11 monitors whether a current is flowing for each detection circuit. When the detection device 11 does not detect the current flow in the detection circuit, the detection device 11 determines that the switch 6 connected to the circuit is in an open state. Further, when the detection device 11 detects a current flow in a circuit, the detection device 11 determines that the switch 6 connected to the circuit has been closed.

  In the level meter 1 configured as described above, a spare switch 6 b corresponding to the size of the level meter 1 is provided inside the guide member 2. In the level meter 1, the switch 6 and the support member 5 are connected so that they can be easily attached and detached. In the level meter 1, the wiring 62 from the spare switch 6 b is connected to the input terminal 3 b of the terminal block 3.

  Thus, when a failure occurs in the detection switch 6a, the level meter 1 can easily remove the detection switch 6a from the support member 5 and replace the spare switch 6b with the detection switch 6a having the failure. Can be easily mounted in position. Further, the wiring 62 from the spare switch 6b connected to the input terminal 3b of the terminal block 3 can be easily connected to the input terminal 3a to which the wiring 62 from the detection switch 6a is connected. Therefore, the step of preparing the replacement switch 6 becomes unnecessary, and the number of steps for replacing the switch 6 is reduced, so that the level meter 1 that can be easily maintained can be provided.

  Next, the operation principle of the switch 6 will be described with reference to FIG.

  As shown in FIG. 4A, the switch 6 is arranged such that one lead piece 61a and the other lead piece 61b face each other at a predetermined interval. A bias magnet 61c for maintaining a closed state in which the leads are in contact with each other is provided on one of the lead pieces 61a. At this time, due to the magnetic force of the bias magnet 61c, the contact 61d of one of the lead pieces 61a has an S pole, and the contact 61e of the other lead piece 61b has an N pole.

  The minimum magnetic force required for the switch 6 to change from the open state to the closed state (hereinafter, simply referred to as “closed magnetic force”) is the maximum magnetic force at which the switch 6 is changed from the closed state to the open state (hereinafter, simply referred to as “open magnetic force”). Greater than. The magnetic force of the bias magnet 61c is weaker than the closed magnetic force and larger than the open magnetic force. That is, the switch 6 does not change from the open state to the closed state due to only the magnetic force of the bias magnet 61c, and does not change from the closed state to the open state (maintains the closed state). The magnetic force of the opening / closing magnet 10b is larger than the difference between the closing magnetic force of the switch 6 and the magnetic force of the bias magnet 61c, and is larger than the difference between the magnetic force of the bias magnet 61c and the opening magnetic force of the switch 6. That is, the switch 6 is switched from the open state to the closed state when the magnetic force of the bias magnet 61c is increased by the magnetic force of the opening / closing magnet 10b, and the magnetic force of the bias magnet 61c is weakened (canceled) by the magnetic force of the opening / closing magnet 10b. This changes the state from the closed state to the open state.

  As shown in FIG. 4B, when the opening / closing magnet 10b of the floating member 10 is at a position facing the one lead piece 61a side having the bias magnet 61c, the contact 61d of the one lead piece 61a has an S pole. In this state, a magnetic force larger than the closed magnetic force is generated, and a contact point 61e of the other lead piece 61b generates a magnetic force larger than the closed magnetic force in the N-pole state. Accordingly, the switch 6 in the open state is closed by the magnetic force of the bias magnet 61c being increased by the magnetic force of the opening / closing magnet 10b.

  As shown in FIG. 4C, when the opening / closing magnet 10b moves away from the bias magnet 61c on the one lead piece 61a side (see the black arrow), the switch 6 contacts the one lead piece 61a. At 61d, a magnetic force larger than the open magnetic force is generated in the state of the S pole, and the contact 61e of the other lead piece 61b generates a magnetic force larger than the open magnetic force in the state of the N pole. As a result, the switch 6 in the closed state maintains the closed state by the magnetic force of the bias magnet 61c.

  As shown in FIG. 4D, when the opening / closing magnet 10b is at a position facing the other lead piece 61b having no bias magnet 61c, the magnetic pole of the contact on the other lead piece 61b is reversed. At this time, a magnetic force smaller than the open magnetic force is generated at the contact 61d of one lead piece 61a in the state of the N pole, and the contact 61e of the other lead piece 61b is smaller than the open magnetic force in the state of the S pole. Magnetic force is generated. That is, the switch 6 in the closed state is opened by the magnetic force of the bias magnet 61c being weakened by the magnetic force of the opening / closing magnet 10b. The switch 6 does not close (maintains an open state) due to the magnetic force of the bias magnet 61c even if the opening / closing magnet 10b moves in the direction away from the bias magnet 61c (see the white arrow) on the other lead piece 61b side. . As described above, the switch 6 is opened and closed by the magnetic force of the bias magnet 61c and the magnetic force of the opening / closing magnet 10b, and is kept closed by the bias magnet 61c, so that power such as electric power is not required.

  The level meter 1 configured as described above is fixed to the upper gantry Ca of the container C via the mounting flange 2a of the guide member 2, so that the moving direction of the floating member 10 is regulated in the vertical direction by the guide member 2. (See FIG. 1). In the level meter 1, the floating member 10 moves along the guide member 2 according to the liquid level position of the fluid L in the container C. In the level meter 1, when the floating member 10 reaches the position of the bias magnet 61c of the switch 6, the switch 6 at each position is closed. Thus, the level meter 1 can detect that the liquid level has reached the position where the switch 6 is attached. Since the closed state of the level meter 1 is maintained by the self-holding switch 6, there is no need to provide the floating member 10 for each switch 6. That is, the level meter 1 can detect whether each switch 6 is located in the fluid L by the single floating member 10.

  Next, the connection structure between the switch 6 and the support member 5 in the level meter 1 will be described in detail.

  First, a connection structure between the switch 6 and the support member 5 according to the present embodiment will be described with reference to FIG. As shown in FIG. 5, in the present embodiment, the switch 6 and the support member 5 are connected via a connection member 7.

  The connection member 7 has a connection portion 71 and a holding portion 72. The connecting portion 71 is a rod-shaped member longer than the axial length of the switch 6. The connection portion 71 is formed of a metal such as stainless steel or a resin. The connecting portion 71 is connected to the switch 6 by a holding portion 72 so as to protrude to one and the other from both ends in the axial direction of the switch 6.

  The holding portion 72 is formed of a heat-shrinkable tube made of vinyl chloride, silicon rubber, a fluorine-based polymer, or the like, which shrinks when subjected to heat processing. The holding portion 72 is contracted by being heated while the switch 6 and the connection portion 71 are housed inside the tube, and holds the switch 6 and the connection portion 71 in close contact with each other. Thereby, the connection member 7 is fixed to the switch 6 so as not to be detachable. In the present embodiment, it is sufficient that the connection member 7 can be fixed to the switch 6 so as to protrude from one end and the other end than both ends in the axial direction of the switch 6, and the switch 6 and the connection member 7 are integrally formed. It may be. For example, the configuration may be such that the molded portion 64 of the switch 6 is formed so as to protrude in the axial direction from the switch main body portion 61 in one and the other direction, and the protruding portion functions as the connection portion 71.

  The switch 6 is detachably connected to the support member 5 at two locations at the connection portion 71 protruding from one end and the other from both ends in the axial direction of the switch 6. Specifically, the switch 6 is attached to the support member 5 with a string (for example, made of hollow silicon) made of a material capable of holding a position with respect to the support member 5 as the attachment member 8. In addition, the attachment member 8 is not limited to the one made of the silicon string, and may be any configuration that can be detachably attached to the support member 5, such as a clip that grips the connection portion 71 and the support member 5.

  In this way, the switch 6 is connected to the support member 5 by the attachment member 8 via the connection member 7 at a position that does not overlap the switch 6 in the axial direction of the support member 5. Therefore, in the level meter 1, the switch 6 can be easily attached to and detached from the support member 5 by the attachment member 8. Further, since the switch 6 is connected to the support member 5 by being attached to the support member 5, the switch 6 can be easily removed from the support member 5 by releasing the attachment member 8.

(Modification 1 of Embodiment 1)
Next, a connection structure between the support member 5 and the switch 6 according to the first modification of the first embodiment will be described with reference to FIGS. 6 and 7. As shown in FIG. 6, in this embodiment, the switch 6 and the support member 5 are connected by a connection member 107.

  The connection member 107 is formed by processing a single strip-shaped metal piece having high corrosion resistance, such as stainless steel, to have a holding portion 172 holding the switch 6 and a connection portion 171 connected to the support member 5. ing.

  The holding portion 172 is formed in an arc shape such that the longitudinal direction of the metal piece is the circumferential direction and is curved in the thickness direction. The holding portion 172 has a shape in which a part of the ring is opened. The switch 6 is inserted and held inside the ring of the holding portion 172. The inner diameter of the ring of the holding portion 172 is formed to be smaller than the outer diameter of the switch 6. Thus, when the switch 6 is fitted, the holding portion 172 exerts a gripping force on the switch 6 that tightens in the axial direction of the switch 6. Therefore, the holding unit 172 holds the switch 6 immovably.

  The connecting portion 171 has arcuate claws formed continuously from both ends of the opening of the ring of the holding portion 172. One side of the connection part 171 is formed integrally with the holding part 172. The other side of the connection part 171 is open. The connection portion 171 is connected to the support member 5 by fitting the support member 5 from the opening. In the connection portion 171, the inner peripheral surface of each of the claws forms a part of a ring. The inner diameter of the ring formed by the connection portion 171 is formed to be smaller than the outer diameter of the support member 5. Thus, when the support member 5 is fitted, a gripping force is applied to the connection portion 171 in the axial direction of the support member 5. Therefore, the connection portion 171 is immovably connected to the support member 5.

  As shown in FIG. 7, the two connecting members 107 are configured such that the support member 5 can be fitted to the connecting portion 171 in a state where the switch 6 is immovably held by the holding portion 172. That is, the connection member 7 is detachably connected to the support member 5 while holding the switch 6. Thus, in the level meter 1, by using the connection member 107, the switch 6 can be repeatedly attached to the support member 5 or removed from the support member 5.

(Modification 2 of Embodiment 1)
Next, a connection structure between the support member 5 and the switch 6 according to the second modification of the first embodiment will be described with reference to FIGS. 8 and 9.

  As shown in FIG. 8, in the present embodiment, the switch 6 and the support member 5 are connected by a connection member 207. The connection member 207 has a connection portion 271 to which the support member 5 is connected and a holding portion 272 to which the switch 6 is connected. The shape of the connection member 207 is similar to that of the connection member 107, and is formed by processing one strip-shaped metal piece. The connection member 207 has the same configuration as that of the connection member 107 except that an opening is formed on the holding portion 272 side, and thus a detailed description is omitted.

  As shown in FIG. 9, the connection member 207 is configured such that the switch 6 can be fitted to the holding portion 272 in a state where the connection portion 271 is immovably connected to the support member 5. That is, the connection member 207 detachably holds the switch 6 while being connected to the support member 5.

  By using the connection member 207, the level meter 1 can repeatedly attach and detach the switch 6 to and from the connection member 207 connected to the support member 5. Further, in this embodiment, the switch 6 can be replaced while the connection member 207 is attached to the support member 5. Therefore, even if the switch 6 is removed, the position where the switch 6 to be replaced is attached is clear, and the switch 6 can be easily replaced. In the above-described embodiment, two connecting members 107 and 207 are provided for the switch 6, but the present invention is not limited to this. One of the connecting members 107 and 207 may hold the switch 6, or the plurality of connecting members 107 and 207 may hold the switch 6.

(Other Modifications of Embodiment 1)
In the first modification of the first embodiment, the connection member 107 is fixed to the switch 6. However, the molded part 64 of the switch 6 and the connection member may be configured integrally.

  As shown in FIG. 10, a connection member 307 is formed integrally with the switch 6, for example. In the switch 6, the molded portion 64 holds the switch main body 61 as the holding portion 372 of the connection member 307. Further, the switch 6 has a connection portion 371 formed of a recess in which the support member 5 can be fitted in a part of the mold portion 64. The switch 6 is detachably connected to the support member 5 by fitting the support member 5 to the connection portion 371.

(Embodiment 2)
Next, a level meter 1 which is a float type level meter according to a second embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 11, in the present embodiment, the spare switch 6b is connected to the support member 5 within the range of movement of the floating member 10. Further, in the present embodiment, the level meter 1 has the rotation stopper 12 of the floating member 10. Further, in the present embodiment, the configuration of the floating member 10 is different from the configuration of the floating member of the first embodiment. The other configuration is the same as that of the first embodiment, and thus the same reference numerals are given and the detailed description is omitted.

  The rotation stopper 12 is a rod-shaped member formed of a metal having high corrosion resistance such as stainless steel. The rotation stopper 12 is provided on the outer peripheral side at a predetermined distance from the guide member 2 so as to extend along the direction in which the guide member 2 extends. Note that the rotation stopper 12 may be formed integrally with the surface of the guide member 2. For example, the rotation stopper 12 may be a protrusion or a recess extending in the axial direction of the guide member 2.

  In this embodiment, the floating member 10 is provided with the opening and closing magnet 10b only in a part. Further, the floating member 10 is provided with a hole penetrating in the axial direction of the guide member. The rotation stopper 12 is inserted through the hole. As a result, the floating member 10 does not rotate in the circumferential direction with respect to the guide member 2. The detection switch 6a is connected to the support member 5 within a range where the magnetic force of the opening / closing magnet 10b reaches. The spare switch 6b is connected to the support member 5 in a range where the magnetic force of the opening / closing magnet 10b does not reach. The detection switch 6a is fixed to the support member 5 so as to face the opening / closing magnet 10b. With this configuration, in the level meter 1, even if the floating member 10 moves, the spare switch 6 b does not operate, so that the spare switch 6 b can be arranged at an arbitrary position of the support member 5. Thus, in the level meter 1, since the spare switch 6b can be arranged near the detection switch 6a, the switch can be easily replaced when the detection switch 6a breaks down.

(Embodiment 3)
Next, a level meter 1 which is a float type level meter according to a third embodiment of the present invention will be described with reference to FIGS.

  As shown in FIGS. 12 and 13, in the present embodiment, the spare switch 6 b is covered with a shield material 65. The other configuration is the same as that of the first embodiment, and thus the same reference numerals are given and the detailed description is omitted.

  The spare switch 6b is covered with a shield member 65 that cuts off the magnetic force from the opening / closing magnet 10b and makes the magnetic force less than the minimum operating magnetic force. The shield material 65 is made of a container made of iron, permalloy, sendust, silicon steel, or the like, a sheet containing these materials, or the like. The spare switch 6b is covered with, for example, a shield member 65 while being connected to the support member 5 via the connection member 7. Thus, the spare switch 6b does not operate even in a range where the magnetic force from the opening / closing magnet 10b reaches. That is, the spare switch 6b does not operate by the magnetic force even if it is connected to the support member 5 within the movement range of the floating member 10. With this configuration, in the level meter 1, even if the floating member 10 moves, the spare switch 6 b does not operate, so that the spare switch 6 b can be arranged at an arbitrary position of the support member 5. Thus, in the level meter 1, when the detection switch 6a fails, the switch can be easily replaced.

  The above-described embodiment merely shows a typical form, and can be variously modified and implemented without departing from the gist of the embodiment. Needless to say, the present invention can be embodied in various forms, and the scope of the present invention is indicated by the description of the claims, and furthermore, has the equivalent meaning described in the claims, and all the claims within the scope. Including changes.

1 Level meter (float type level meter)
2 Guide Member 5 Support Member 5a Extension 6 Switch 6a Detection Switch 6b Spare Switch 7, 107, 207, 307, 407 Connection Member 9 Fixed Member 10 Floating Member

Claims (8)

A tubular guide member, a support member provided inside the guide member and extending in the axial direction of the guide member, a floating member movable in the axial direction of the guide member, and a magnet provided in the floating member. A self-holding type switch operated by magnetic force, wherein the floating member moves with the displacement of the liquid level, and the switch is operated to detect the position of the liquid level. ,
The switch includes a detection switch connected to a position of the support member that operates when the floating member moves, and a spare switch that is provided at a position that does not operate even when the floating member moves.
Float type level meter. It is a float type level meter of Claim 1, Comprising:
A connection member including a connection portion connected to the support member and a holding portion holding the switch,
Float type level meter. It is a float type level meter of Claim 2, Comprising:
The connection member is configured such that the support member is detachably attached to the connection portion in a state where the switch is held by the holding portion.
Float type level meter. It is a float type level meter of Claim 2, Comprising:
The connection member is configured such that the switch is detachably attached to the holding unit in a state where the support member is connected to the connection unit.
Float type level meter. The float type level meter according to claim 2 or 3, wherein
The connection member has a connection portion protruding to one and the other than both ends of the switch in the axial direction of the support member,
The connection portion and the support member are detachably connected,
Float type level meter. A float-type level meter according to any one of claims 1 to 5,
The switch has a switch main body and wiring,
A part of the wiring and the switch body are molded with resin;
Float type level meter. It is a float type level meter according to any one of claims 1 to 6,
The guide member and the support member each have an extending portion that extends to at least one of one side and the other side than the movement range of the floating member,
The spare switch is connected to an extension of the support member,
Float type level meter. A tubular guide member, a support member provided inside the guide member and extending in the axial direction of the guide member, a floating member movable in the axial direction of the guide member, and a magnet provided on the floating member. A self-holding switch that operates when receiving a magnetic force equal to or more than a predetermined value, wherein the floating member moves with the displacement of the liquid level, and the switch operates to change the position of the liquid level. A float type level meter for detection,
The switch includes a detection switch that is connected to the support member and operates when the floating member moves, and a spare switch that is covered with a shield material that blocks a magnetic force equal to or greater than the predetermined value.
Float type level meter.

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