Liquid Level Gauge
The liquid level measuring meter addresses the issue of horizontal swinging in existing meters by using a guide mechanism with guide pins and a mechanical switch with a detection unit, achieving stable and accurate liquid level detection.
Patent Information
- Application Number
- JP2022027420
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-02-25
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2042-02-25
AI Technical Summary
Existing liquid level measuring meters using floats and actuation shafts face instability due to horizontal swinging of the operating shaft within the guide body, leading to inaccurate liquid level measurements.
The liquid level measuring meter incorporates a guide mechanism with pair of guide pins and guide holes, and a mechanical switch with a detection unit and biasing member, allowing the actuating member to move stably and accurately detect liquid levels by aligning the detection unit with recesses on the actuating member.
This configuration enables stable and accurate detection of both liquid drop and liquid rise levels, improving the reliability of liquid level measurements by minimizing horizontal movement of the operating shaft.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to a liquid level gauge that uses a float to measure the level of a liquid. [Background technology]
[0002] A known liquid level gauge uses a float that moves up and down with the level of the liquid contained in a liquid storage container (see, for example, Patent Document 1). In this liquid level gauge, an operating shaft is attached to the float, and the tip side of this operating shaft extends upward through an insertion hole of a measurement main body attached to the liquid storage container, and a pointer is attached to the tip. A guide body for guiding the operating shaft in the up and down direction is attached to this measurement main body, a guide rail is attached to this guide body, and proximity switches are attached to this guide rail so that their positions can be adjusted freely, and for example, a first proximity switch is arranged corresponding to a liquid lowering level where the liquid level has dropped, and for example, a second proximity switch is arranged corresponding to a liquid rising level where the liquid level has risen.
[0003] In this liquid level gauge, when the liquid level in the liquid container drops (or rises), the operating shaft and pointer drop (or rise) together with the float in accordance with the drop (or rise) of the liquid level, and by looking at this pointer, the position of the liquid level, in other words, the amount of liquid in the liquid container, can be known. Also, when the magnetic part of the operating shaft drops (or rises) to the first proximity switch (or the second proximity switch), the first proximity switch (or the second proximity switch) detects the magnetic part of the operating shaft, and it can be detected that the liquid level has dropped (or risen) to the liquid lowering level (or liquid rising level). [Prior art documents] [Patent documents]
[0004] [Patent Document 1] JP 2014-59195 A Summary of the Invention [Problem to be solved by the invention]
[0005] However, in this liquid level gauge, the operating shaft attached to the float is arranged inside a roughly cylindrical guide body, so that an annular space exists between the guide body and the operating shaft. Due to this environmental space, the operating shaft is prone to vibrating laterally as it moves up and down together with the float, making it difficult to stably and accurately measure the liquid level of the liquid in the liquid storage container.
[0006] An object of the present invention is to provide a liquid level gauge that can stably and accurately measure the liquid level of a liquid in a liquid storage container. [Means for solving the problem]
[0007] The present invention Liquid level gauge is a liquid level gauge comprising a liquid container for containing a liquid, a float that floats on the liquid contained in the liquid container and moves up and down with fluctuations in the liquid level, an operating member attached to the float, a guide mechanism that guides the operating member so as to be movable up and down, and a mechanical switch for detecting the liquid level of the liquid, the guide mechanism includes a guide member for guiding the operating member, the guide member having a pair of guide pins arranged at a distance from one another in the vertical direction, and the operating member having a guide hole extending in the vertical direction, the pair of guide pins being inserted into the guide hole so as to be freely movable; The mechanical switch includes a switch body attached to the guide member, a detection portion provided on the switch body so as to be movable between a detection position protruding toward the actuating member and a non-detection position retracted from the detection position, and a biasing member that elastically biases the detection portion toward the detection position, and the actuating member is provided with a recess corresponding to a predetermined liquid level to be measured, Further, the detection portion of the mechanical switch and one of the pair of guide pins are located at the same level in the vertical direction, and a biasing force from the detection portion of the mechanical switch acts on the one of the guide pins via the operating member, When the liquid level in the liquid container reaches the predetermined liquid level, the recess of the actuating member faces the detection portion of the mechanical switch, whereby the detection portion fits into the recess on the actuating member by the action of the biasing member, and is positioned at the detection position.
[0009] In such liquid level gauges, It is preferable to set a liquid drop level and a liquid rise level as the predetermined liquid level, attach a first mechanical switch to one side of the guide member corresponding to the liquid drop level, attach a second mechanical switch to the other side of the guide member corresponding to the liquid rise level, and further provide a first recess for detecting the liquid drop level on one side of the operating member and a second recess for detecting the liquid rise level on the other side. By configuring in this way, the liquid drop level at which the liquid level has dropped and the liquid rise level at which the liquid level has risen can be detected by the first and second mechanical switches. Also, since the biasing forces from the first and second mechanical switches act from both sides of the guide member that moves up and down, the operating member can be stably guided.
[0010] In addition, in such a liquid level gauge, it is preferable that the first detection portion of the first mechanical switch and one of the pair of guide pins are at the same level in the vertical direction, and that the second detection portion of the second mechanical switch and the other of the pair of guide pins are at the same level in the vertical direction.By configuring in this manner, the biasing force from the first detection portion of the first mechanical switch acts on one of the pair of guide pins via the operating member, and the biasing force from the second detection portion of the second mechanical switch acts on the other of the pair of guide pins via the operating member, thus allowing the biasing forces from the first and second mechanical switches to be stably and reliably supported by the pair of guide pins.
[0011] Furthermore, for the first mechanical switch, it is preferable that the first switch body is attached to one side of the guide member so that the first pressing arm of the first detection portion extends inward from one end side of the first switch body, and for the second mechanical switch, the second switch body is attached to the other side of the guide member so that the second elastic arm of the second detection portion extends inward from one end side of the second switch body, and the first mechanical switch and the second mechanical switch are arranged back-to-back in the vertical direction.
[0012] With this configuration, when the liquid level drops to the liquid-lowering level, the first acting portion of the first detection portion of the first mechanical switch faces the first recess of the actuating member, and the first acting portion fits into the first recess by the biasing action of the first biasing member, positioning the first detection actuating portion at the detection position, and when the liquid level rises to the liquid-rising level, the second acting portion of the second mechanical switch faces the second recess of the actuating member, and the second acting portion fits into the second recess by the biasing action of the second biasing member, positioning the second detection actuating portion at the detection position. Thus, the first and second mechanical switches can accurately and reliably detect the liquid-lowering level and the liquid-rising level. Effect of the Invention
[0013] According to the liquid level gauge described in claim 1 of the present invention, a pair of guide pins are arranged at intervals in the vertical direction on the guide member, a guide hole extending in the vertical direction is provided in the operating member, and the pair of guide pins are inserted into this guide hole so as to be able to move freely. Therefore, when the operating member moves up and down together with the float, the pair of guide pins move relatively along this guide hole, and thus the operating member can be moved stably to accurately detect the liquid level.
[0014] The mechanical switch also includes a detection part provided on the switch body so as to be movable between a detection position and a non-detection position retracted from the detection position, and a biasing member which elastically biases the detection part toward the detection position. The operating member is provided with a recess corresponding to a predetermined liquid level, so that when the liquid level reaches the predetermined liquid level, the recess of the operating member faces the detection part of the mechanical switch, and the biasing action of the biasing member causes the detection part of the mechanical switch to fit into the recess of the operating member and be positioned at the detection position, and thus the predetermined liquid level of the liquid can be detected by this mechanical switch. Furthermore, since the detection part of the mechanical switch and one of the pair of guide pins are at the same level in the vertical direction, the biasing force from the detection part of the mechanical switch acts on one of the guide pins via the operating member, and the biasing force due to the biasing member can be stably and reliably supported by the guide pin. [Brief description of the drawings]
[0015] [Figure 1] 1 is a cross-sectional view showing an embodiment of a liquid level gauge according to the present invention. [Diagram 2] 2 is a cross-sectional view partially showing a guide mechanism and an operating member of the liquid level gauge of FIG. 1, as well as configurations related thereto; [Diagram 3] 2 is a partial cross-sectional view showing the liquid level gauge of FIG. 1 in a state where the liquid level is at a standard level. [Figure 4] 2 is a partial cross-sectional view showing a state in which the liquid level has risen to a liquid rising level in the liquid level gauge of FIG. 1. [Diagram 5] 2 is a partial cross-sectional view showing a state in which the liquid level of the liquid has risen beyond the liquid rising level in the liquid level gauge of FIG. 1. [Figure 6] 2 is a partial cross-sectional view showing a state in which the liquid level has dropped to a liquid drop level in the liquid level gauge of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] An embodiment of a liquid level gauge according to the present invention will be described below with reference to the accompanying drawings. In Figures 1 and 2, the liquid level gauge 2 shown is used in a liquid storage container, for example, a liquid tank 4, that stores a liquid 3, such as hydraulic oil used for hydraulics, lubricating oil used for lubrication, or fuel oil used as fuel. The liquid tank 4 includes a tank body 6 that stores the liquid 3, and an insertion port 10 is provided in the approximate center of an upper wall 8 of the tank body 6.
[0017] The liquid level gauge 2 will be described. The liquid level gauge 2 comprises a float 12 that floats on the liquid 3, an actuating member 14 that moves up and down integrally with the float 12, and a guide mechanism 16 that movably guides the actuating member 14. The float 12 comprises, for example, a hollow cylindrical float body 18, to which the actuating member 14 is attached. In this embodiment, a connecting rod 20 is attached to the float body 18, and the actuating member 14 is attached to the tip of the connecting rod 20 that extends upward through the insertion port 10 of the tank body 6. It is to be noted that the connecting rod 20 may be omitted, and the actuating member 14 may be attached directly to the float 12.
[0018] With this configuration, when the liquid level 22 of the liquid 3 moves up and down, the float 12 (float body 18) moves up and down due to the up and down movement, and the connecting rod 20 and the operating member 14 move up and down integrally with the float 12.
[0019] Referring also to Figure 2, the operating member 14 is composed of an elongated plate-like member, and has an elongated guide hole 24 provided in the middle of its longitudinal direction. This guide hole 24 extends in the longitudinal direction of the operating member 14 (the up-down direction of the liquid level gauge 2).
[0020] The guide mechanism 16 also includes a gate-shaped guide member 25, which is composed of a pair of mounting plates 26, 28 and connection plates 30, 32 that connect the plates 26, 28. A flange member 34 is attached to the periphery of the insertion hole 10 in the upper wall 8 of the tank body 6, and the guide member 25 (the lower ends of the pair of mounting plates 26, 28) is fixed to the end face of an upper flange 36 of the flange member 34 by, for example, a fixing screw 38.
[0021] The pair of mounting plates 26, 28 extend upward from the upper flange 36 of the flange member 34, and a pair of connection plates 30, 32 are connected between the mounting plates 26, 28 at a distance in the vertical direction, and the operating member 14 is disposed on the front side of the pair of connection plates 30, 32. A flat head screw 39 (forming a guide pin) is screwed into each of the connection plates 30, 32 from the back side, and the head (not shown) of the flat head screw 39 is fixed to the connection plates 30, 32 by welding or the like. The shaft of the flat head screw 39 extends to the front side through the guide hole 24 of the operating member 14, and a nut 40 (so-called washer nut) with a washer welded to the back side and the front side of the operating member 14 is screwed thereto. It is preferable that the washer nut 40 is provided with a locking mechanism to prevent it from coming loose.
[0022] 2 and 3, a backside washer nut (not shown) is located on the backside of the operating member 14, and a washer nut 40 is also located on the front side thereof, so that the operating member 14 is sandwiched between the washers of the washer nut 40. A pair of flat head screws 39 (guide pins) are inserted into the guide hole 24 of the operating member 14. Therefore, the movement of the operating member 14 is restricted on the backside and frontside by the washers of the washer nut 40, and in the lateral direction by the pair of flat head screws 39 (guide pins). With this configuration, the operating member 14 is stably moved in the vertical direction (vertical direction in FIGS. 2 to 6) by the vertical movement of the float 18 accompanying the fluctuation of the liquid level 22, and during this vertical movement, the shafts of the pair of flat head screws 39 are moved relatively along the guide hole 24 of the operating member 14.
[0023] In this embodiment, one elongated guide hole 24 is provided in the operating member 14, and two flat head screws 39 (guide pins) are inserted through this guide hole 24. However, instead of this configuration, an elongated guide hole (not shown) may be provided corresponding to each flat head screw 39, and the flat head screws 39 may be inserted through each guide hole.
[0024] 3, in this embodiment, a first recess 42 for detecting a low liquid level (e.g., a liquid level indicating that the liquid has decreased and needs to be replenished) is provided on one side of the actuating member 14, and a first mechanical switch 44 is disposed corresponding to this first recess 42. The first recess 42 is constituted by a notch or the like that opens on one side of the actuating member 14, and has a first bottom 46 extending in the longitudinal direction and a first inclined portion 48 that extends at an angle from that one side surface toward the first bottom 46.
[0025] Further, a second recess 50 is provided on the other side of the actuating member 14 for detecting the rising liquid level of the liquid in the liquid tank 4 (for example, the liquid level when the liquid is sufficiently filled), and a second mechanical switch 52 is disposed corresponding to the second recess 50. The second recess 50 is constituted by a notch or the like that opens into the other side of the actuating member 14, and has a second bottom 54 extending in the longitudinal direction, and a second inclined portion 56 that extends at an angle from the other side surface toward the second bottom 54.
[0026] The first mechanical switch 44 and the second mechanical switch 50 may be, for example, a commercially available general-purpose basic switch (such as a switch called a roller short lever type switch). The first mechanical switch 44 (second mechanical switch 50) has a first switch body 58 (second switch body 60) and a first detection section 62 (second detection section 64) for detecting a lowered liquid level (rising liquid level), and this first switch body 58 (second switch body 60) is attached to one mounting plate 26 (the other mounting plate 28).
[0027] In this embodiment, a long and narrow first mounting hole 66 (second mounting hole 68) is provided at a predetermined position of one mounting plate 26 (the other mounting plate 28), and the first switch body 58 (second switch body 60) is attached to one mounting plate 26 (the other mounting plate 28) in a position-adjustable manner by screwing a mounting screw (not shown) into the first switch body 58 (second switch body 60) through this first mounting hole 66 (second mounting hole 68).
[0028] In addition, the first detection portion 62 (second detection portion 64) of the first mechanical switch 44 (second mechanical switch 52) includes a first pressing arm 70 (second pressing arm 72) attached to one end of the first switch body 58 (second switch body 60) so as to be freely swingable, a first action portion 74 (second action portion 76) provided at the tip of the first pressing arm 70 (second pressing arm 72), and a first detection operation portion 78 (second detection operation portion 80) pressed by the first pressing arm 70 (second pressing arm 72), and the first action portion 74 (second action portion 76) is composed of, for example, an action roller attached to the tip of the first pressing arm 70 (second pressing arm 72) so as to be freely rotatable.
[0029] Also, in this embodiment, the first detection operation portion 78 (second detection operation portion 80) of the first detection portion 62 (second detection portion 64) is mounted so as to be freely movable between a detection position (position shown in FIG. 2) in which it protrudes from the first switch body 58 (second switch body 60) and a non-detection position in which it retracts from this detection position and is stored in the first switch body 58 (second switch body 60), and a first biasing member (second biasing member) (not shown) is provided in association with this first detection operation portion 78 (second detection operation portion 80) for elastically biasing this first detection operation portion 78 (second detection operation portion 80) toward the detection position.
[0030] As configured in this manner, when the first acting portion 74 (second acting portion 76) of the first detection portion 62 (second detection portion 64) of the first mechanical switch 44 (second mechanical switch 52) is not pressed, the first detection operating portion 78 (second detection operating portion 80) is held in the detection position (see FIG. 2) by the action of the first biasing member (second biasing member) (not shown), whereby the first pressing arm 70 (second pressing arm 72) is swung in a direction away from the first switch body 58 (second switch body 60). Furthermore, when a pressing force acts on the first acting portion 74 (second acting portion 76) of this first detection portion 62 (second detection portion 64) and the first pressing arm 70 (second pressing arm 72) is swung in a direction approaching the first switch body 58 (second switch body 60), the first pressing arm 70 (second pressing arm 72) is pressed against it, and the first detection operation portion 78 (second detection operation portion 80) is stored in the first switch body 44 (second switch body 52) and held in the non-detection position (see FIG. 3).
[0031] In order to stably hold the operating member 14, the liquid level gauge 2 is further configured as follows. Mainly referring to Fig. 3, in this embodiment, the first mechanical switch 44 is disposed below the second mechanical switch 52, and the first action portion 74 (acting roller) (specifically, its rotation center) and the flat head screw 39 (guide pin) (specifically, its center) of the first mechanical switch 44 are configured to be at substantially the same level L1 in the vertical direction. Also, the second action portion 76 (acting roller) (specifically, its rotation center) and the flat head screw 39 (guide pin) (specifically, its center) of the second mechanical switch 52 are configured to be substantially the same level L2 in the vertical direction.
[0032] 3, when the first mechanical switch 44 is in the open state, the biasing force from the first biasing member (not shown) is transmitted to one side (the right side in FIG. 3) of the operating member 14 via the first detection operation portion 78, the first pressing arm 70, and the first action portion 74 (action roller), and acts toward the center of the flat head screw 39 (guide pin). Therefore, the biasing force F1 acting on the operating member 14 is supported by the flat head screw 39 (guide roller), and does not act to rotate the operating member 14 around the flat head screw 39 (guide pin), but stably guides and supports the lower side of the operating member 14.
[0033] Also, when the second mechanical switch 52 is in the open state, similarly to the first mechanical switch 44, the biasing force from the second biasing member (not shown) is transmitted to the other side (left side in FIG. 3) of the operating member 14 via the second detection operation portion 80, the second pressing arm 72, and the second acting portion 76 (acting roller), and acts toward the center of the flat head screw 39 (guide pin). Therefore, this biasing force F2 acting on the operating member 14 is supported by the flat head screw 39 (guide roller), and does not act to rotate the operating member 14 about the flat head screw 39 (guide pin), but stably guides and supports the upper side of the operating member 14.
[0034] 1 and 2, in this liquid level gauge 2, a hollow cylindrical tubular cover 92 is attached to the upper end surface of the upper flange 36 of the flange member 34, and a cap member 94 is removably attached to the upper end of this tubular cover 92. This tubular cover 92 is formed from a transparent resin material, such as acrylic resin, and by configuring it in this manner, the inside of the tubular cover 92, such as the operating member 14, the first mechanical switch 44, and the second mechanical switch 52, can be visually confirmed from the outside.
[0035] Furthermore, a mark (e.g., an arrow, etc.) for indicating the liquid level of the liquid 3 in the liquid tank 4 may be provided on the operating member 14, and an indication scale (not shown) may be provided on the upper surface of the upper flange 36 of the flange member 34 so that the liquid level can be read using this indication scale.By configuring in this manner, the liquid level 22 of the liquid 3 can be accurately measured.
[0036] This liquid level gauge 2 detects the level of the liquid 3 in the liquid tank 4 (liquid storage container) as follows: When the amount of the liquid 3 contained is the standard amount (in other words, the liquid level is at the standard level), the liquid level 22 in the liquid tank 4 is at the level shown by the solid line in Fig. 1, and in this standard state, the float 12 is in the state shown by the solid line in Fig. 1, and corresponding to the floating position of this float 12, the connecting rod 20 and the operating member 14 are in the state shown by the solid line in Fig. 1.
[0037] When the liquid level 22 of the liquid 3 is at a standard level, the actuating member 14, which moves due to the up and down movement of the float 12, is in the state shown in Fig. 3. Referring to Fig. 3, the first detection portion 62 (first action portion 74) of the first mechanical switch 44 is located below the first recess 42 of the actuating member 14, and when the first action portion 74 is pressed by one side of the actuating member 14, the first detection and operation portion 78 is accommodated in the first switch body 58 via the first pressing arm 70 and positioned in the non-detection position, whereby the first mechanical switch 44 is held in the non-detection state. In addition, the second detection portion 64 (second action portion 76) of the second mechanical switch 52 is located above the second recess 50 of the actuating member 14, and when the second action portion 76 is pressed by the other side of the actuating member 14, the second detection and operation portion 80 is accommodated in the second switch body 60 via the second pressing arm 72 and positioned in the non-detection position, whereby the second mechanical switch 52 is also held in the non-detection state. In this way, when the liquid level 22 of the liquid 3 is at a standard level, the first and second mechanical switches 44, 52 are held in an open state.
[0038] For example, when the liquid level 22 of the liquid 3 rises from the standard level to the liquid rising level shown by the two-dot chain line 22A in FIG. 1, as the liquid level 22 rises, the float 12 goes into the state shown by the two-dot chain line 12A in FIG. 1, and in response to this rise in the float 12, the operating member 14, via the connecting rod 20, goes into the state shown by the two-dot chain line 14A in FIG. 1.
[0039] When the liquid level 22 of the liquid 3 rises to the upper liquid level, the float 12 rises, and the operating member 14 is held in the state shown in Fig. 4. Referring to Fig. 4, in this state, the first detection portion 62 (first action portion 74) of the first mechanical switch 44 is pressed by one side surface of the operating member 14, the first detection action portion 78 is held in the non-detection position via the first pressing arm 70, and the first mechanical switch 44 is held in the non-detection state. Meanwhile, the second detection portion 64 (second action portion 76) of the second mechanical switch 52 faces the upper end of the second recess 50 of the operating member 14 that has moved upward, and the second action portion 76 is allowed to swing into the second recess 50. In this way, the second detection actuation portion 80 is positioned at a detection position protruding from the second switch body 60 by the action of the second biasing member (not shown), whereby the second pressing arm 72 and the second acting portion 76 are fitted into the second recess 50 of the actuating member 14, and the second mechanical switch 52 is held in a detection state. In this way, when the liquid level 22 of the liquid 3 rises to the liquid rising level, the second mechanical switch 52 is held in a closed state, and it is possible to detect that the liquid level 22 of the liquid 3 has reached the liquid rising level. The detection signal of this second mechanical switch 52 can be used, for example, as a signal to activate a liquid rising alarm lamp or a liquid rising alarm buzzer that notifies the liquid level rise, and can notify an operator, manager, etc. that the liquid 3 is sufficiently filled.
[0040] When the liquid level 22 of the liquid 3 rises further beyond the upper liquid level, the float 12 rises, causing the actuating member 14 to move further upward from the state shown in Fig. 4 to the state shown in Fig. 5. Referring to Fig. 5, while the float 12 rises in this manner, as can be seen from Fig. 5, the first detection portion 62 (first action portion 74) of the first mechanical switch 44 is maintained in a pressed state by one side surface of the actuating member 14, and the first mechanical switch 44 continues to be held in a non-detection state. On the other hand, the second detection portion 64 (second action portion 76) of the second mechanical switch 52 faces the second recess 50 of the actuating member 14, and is maintained in a detection position where the second detection action portion 80 protrudes from the second switch body 60 by the action of the second biasing member (not shown) (the second pressing arm 72 and the second action portion 76 are held in a state of being fitted into the second recess 50 of the actuating member 14), and the second mechanical switch 52 continues to be held in a detection state. During this time, the second mechanical switch 52 continues to detect the rise in the liquid level, and the detection signal of the second mechanical switch 52 is used to keep the liquid level rise warning lamp, liquid level rise warning buzzer, etc. operating.
[0041] Furthermore, for example, when the liquid level 22 of the liquid 3 falls from the standard level to the liquid drop level shown by the two-dot chain line 22B in FIG. 1, as the liquid level 22 falls, the float 12 reaches the state shown by the two-dot chain line 12B in FIG. 1, and in response to this fall of the float 12, the connecting rod 20 and the operating member 14 fall.
[0042] When the liquid level 22 of the liquid 3 drops to the lower liquid level, the float 12 descends, causing the operating member 14 to assume the state shown in Fig. 6. Referring to Fig. 6, in this state, the first detection portion 64 (second action portion 76) of the first mechanical switch 44 faces the lower end of the first recess 42 of the operating member 14 that has moved downward, and the first action portion 74 is allowed to swing into the first recess 42. Thus, the first biasing member (not shown) positions the first detection action portion 78 at a detection position where it protrudes from the first switch body 58, and as a result, the first pressing arm 70 and the first action portion 74 fit into the first recess 42 of the operating member 14, and the first mechanical switch 44 enters the detection state. On the other hand, the second detection portion 64 (second action portion 76) of the second mechanical switch 52 is held in a pressed state by the other side surface of the actuation member 14, the second detection actuation portion 80 is maintained in a non-detection position via the second pressing arm 72, and the second mechanical switch 52 continues to be held in a non-detection state. In this way, when the liquid level 22 of the liquid 3 drops to the liquid drop level, the first mechanical switch 44 is closed, and it is possible to detect that the liquid level 22 of the liquid 3 has dropped to the liquid drop level. The detection signal of this first mechanical switch 44 can be used, for example, as a signal to activate a low liquid level alarm lamp or low liquid level alarm buzzer that notifies the drop in the liquid level, and it is possible to notify an operator, manager, etc. that the liquid 3 is low.
[0043] Although one embodiment of the liquid level gauge according to the present invention has been described above, the present invention is not limited to this embodiment, and various changes and modifications can be made without departing from the scope of the present invention.
[0044] For example, in the above-described embodiment, the liquid drop level 22B of the liquid level 22 of the liquid 3 is detected by the first mechanical switch 44, and the liquid rise level 22A is detected by the second mechanical switch 52. However, for example, it is also possible to detect only the liquid drop level 22B, in which case the second mechanical switch 52 and the related configuration can be omitted, and it is also possible to detect only the liquid rise level 22A, in which case the first mechanical switch 44 and the related configuration can be omitted. [Explanation of symbols]
[0045] 2. Liquid level gauge 3 liquid 4 Liquid tank (liquid storage container) 12, 12A, 12B Float 14 Actuating member 16 Guide mechanism 22,22A,22B liquid level 25 Guide member 39 Flat head screw (guiding pin) 42 First recess 44 First Mechanical Switch 50 Second recess 52 Second mechanical switch 62 First detection section 64 Second detection section 78 First detection operation part 80 Second detection operation unit
Claims
1. A liquid level gauge comprising: a liquid container for containing a liquid; a float that floats on the liquid contained in the liquid container and moves up and down with fluctuations in the liquid level; an operating member attached to the float; a guide mechanism that guides the operating member so that it can move up and down; and a mechanical switch for detecting the liquid level, the guide mechanism includes a guide member for guiding the operating member, the guide member having a pair of guide pins arranged at a distance from one another in the vertical direction, and the operating member having a guide hole extending in the vertical direction, the pair of guide pins being inserted into the guide hole so as to be freely movable; The mechanical switch includes a switch body attached to the guide member, a detection portion provided on the switch body so as to be movable between a detection position protruding toward the actuating member and a non-detection position retracted from the detection position, and a biasing member that elastically biases the detection portion toward the detection position, and the actuating member is provided with a recess corresponding to a predetermined liquid level to be measured, Further, the detection portion of the mechanical switch and one of the pair of guide pins are located at the same level in the vertical direction, and a biasing force from the detection portion of the mechanical switch acts on the one of the guide pins via the operating member, A liquid level gauge characterized in that when the liquid level of the liquid in the liquid container reaches the predetermined liquid level, the recess of the operating member faces the detection portion of the mechanical switch, whereby the detection portion fits into the recess on the operating member by the action of the biasing member, and is positioned at the detection position.
2. the predetermined liquid level to be measured is a liquid drop level for detecting a drop in the liquid level and a liquid rise level for detecting a rise in the liquid level, the mechanical switch includes a first mechanical switch arranged corresponding to the liquid drop level and a second mechanical switch arranged corresponding to the liquid rise level, and the recess corresponding to the predetermined liquid level to be measured includes a first recess provided on one side of the operating member corresponding to the first mechanical switch attached to one side of the guide member, and a second recess provided on the other side of the operating member corresponding to the second mechanical switch attached to the other side of the guide member, The liquid level gauge described in claim 1, further characterized in that a first detection portion of the first mechanical switch and one of the pair of guide pins are located at the same level in the vertical direction, and a biasing force from the first detection portion of the first mechanical switch acts on the one guide pin via the operating member, and a second detection portion of the second mechanical switch and the other guide pin of the pair of guide pins are located at the same level in the vertical direction, and a biasing force from the second detection portion of the second mechanical switch acts on the other guide pin via the operating member.
3. The liquid level gauge described in claim 2, characterized in that the first mechanical switch comprises a first switch body attached to the one side of the guide member, the first detection unit of the first mechanical switch has a first pressing arm extending inward from one end side of the first switch body, a first acting unit provided at a tip portion of the first pressing arm, and a first detection operation unit pressed by the first pressing arm, and the second mechanical switch comprises a second switch body attached to the other side of the guide member, the second detection unit of the second mechanical switch has a second pressing arm extending inward from one end side of the second switch body, a second acting unit provided at a tip portion of the second pressing arm, and a second detection operation unit pressed by the second pressing arm, and the first mechanical switch and the second mechanical switch are arranged back-to-back in the vertical direction.
Citation Information
Patent Citations
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