JP7482915B2 - Liquid level detection unit for drainage equipment - Google Patents

Description

The present invention relates to a liquid level detection unit for drainage equipment.

In recent years, flooding has occurred in many places due to climate change. The occurrence of flooding is increasing year by year, and the scale of disasters is also growing. For example, when torrential rain suddenly occurs, large amounts of rainwater on the roads can flow into sewers, rivers, and roadside gutters. If more water than expected flows in, the water can overflow from sewers, rivers, roadside gutters, etc., causing damage such as the interruption of transportation networks and flooding of homes.

Detecting changes in the liquid level in drainage facilities such as stormwater manholes installed around houses is important in terms of knowing before a flood occurs. Stormwater manholes have a lattice-like cover like a grating. If more water than expected flows into the manhole through the grating, the liquid level will rise rapidly.

For example, a float switch (liquid level sensor) that is suspended via a cable is known as a sensor that detects the liquid level in a liquid tank such as a rainwater tank (see, for example, Patent Document 1). The float switch described in Patent Document 1 is mounted at a position away from a vertical support by an L-shaped metal arm attached to the support. In the description of Patent Document 1, the length between the arm into which the cable is inserted and the float switch can be adjusted as desired.

Utility Model Registration No. 3069471

However, a liquid level sensor installed in an outdoor rainwater tank is suspended within the tank via a cable and exposed to wind and rain within the tank, which can cause it to sway. For example, when strong winds or a large amount of rainwater enters the tank, the vibration of the cable blown by the wind and the swaying of the water surface can affect the liquid level sensor underwater. This can cause the liquid level sensor to tilt at a position unrelated to the target liquid level to be detected, and therefore there is room for improvement in the method of installing the liquid level sensor within the rainwater tank so that the liquid level sensor can stably detect the liquid level within the tank.

Therefore, the present invention was made in consideration of the above problems, and aims to provide a technology that reduces the adverse effects of rain and wind on liquid level sensors in drainage equipment.

In order to solve the above problems, the liquid level detection unit of the present invention is characterized by comprising: a float-type liquid level sensor that is suspended via a cable within a drainage facility and detects when the liquid level reaches a predetermined level; a support plate that supports the liquid level sensor within the drainage facility so that it can float; a cable guide member that is attached to the cable and has an introduction section where the cable is introduced and an outlet section that leads out the cable at a position where the extension direction of the introduced cable is changed; and a fixing member that fixes the cable guide member to the support plate so that the outlet section faces the side opposite to the support plate.

The present invention can reduce the adverse effects of rain and wind on liquid level sensors in drainage equipment.

1 is a perspective view showing a liquid level detection unit according to an embodiment of the present invention attached to a grating, as viewed from above. 1 is a perspective view showing a liquid level detection unit according to one embodiment of the present invention attached to a grating, viewed from below. FIG. 1 is a perspective view of a liquid level detection unit according to an embodiment of the present invention; 4 is a perspective view of a plate member of the liquid level detection unit according to the embodiment, as viewed from below. FIG. FIG. 2 is a perspective view for explaining the configuration of a liquid level detection switch. FIG. 2 is a front view of the liquid level detection switch. FIG. 4C is a cross-sectional view taken along the line C in FIG. 4B. FIG. 4 is a perspective view of the fixing plate as seen from the outside. FIG. 4 is a perspective view of the fixing plate as seen from the inside. FIG. 13A and 13B are views showing a state in which the fixing plate is engaged with the cable guide member. FIG. 13 is a diagram showing assumed contact points of a liquid level sensor. 13 is a perspective view of a liquid level detection unit provided with a fixed plate according to a modified example, as viewed from one side. FIG. 13 is a perspective view of the liquid level detection unit including the fixed plate according to the modified example, seen from the other side. FIG. FIG. 13 is a perspective view of a fixing plate according to a modified example. FIG. 13 is a perspective view of a fixing plate according to a modified example.

First, an overview of a representative embodiment of the present invention will be described. In the following description, as an example, reference symbols in the drawings that correspond to the components of the invention are given in parentheses.

[1] The liquid level detection unit (1, 1A, 1B) according to the present invention is characterized by comprising: a float-type liquid level sensor (30) suspended via a cable (40) in a drainage facility (100) for detecting when the liquid level has reached a predetermined level; a support plate (12) for supporting the liquid level sensor (30) so that it can float in the drainage facility (100); a cable guide member (50) attached to the cable (40) and having an introduction section (53) where the cable (40) is introduced and an outlet section (54) for guiding the cable (40) at a position where the extension direction of the introduced cable (40) is changed; and a fixing member (60, 60A) for fixing the cable guide member (50) to the support plate (12) so that the outlet section (54) faces the side opposite to the support plate (12).

[2] In a liquid level detection unit (1) according to one embodiment of the present invention, the fixing member includes a pair of fixing plates (60) attached to the support plate (12) in parallel with each other so as to sandwich the cable guide member (50), and each of the fixing plates (60) has at least two engagement portions (63) that engage with the cable guide member (54) on the side where the lead-out portion (54) is provided, and press the cable guide member (50) against the support plate (12).

[3] In the liquid level detection unit (1A) according to one embodiment of the present invention, the fixing member is a single fixing plate (60A) attached to the support plate (12), and the single fixing plate (60A) has at least two engagement portions (63A) that engage with the cable guide member (50) on the side where the lead-out portion (54) is provided and engage with the cable guide member (50) on the side opposite to the side with which the single fixing plate (60A) comes into contact, thereby pressing the cable guide member (50) against the support plate (12).

[4] In the liquid level detection unit (1, 1A, 1B) according to one aspect of the present invention, the engagement portion (63, 63A) is provided at different height positions in the hanging direction of the cable.

[5] In the liquid level detection unit (1, 1A, 1B) according to one aspect of the present invention, one of the engagement portions (63d, 63Ad) is provided between the outlet portion (54) and the support plate (12) in the vicinity of the inlet portion (53) and the outlet portion (54).

[6] In the liquid level detection unit (1, 1A, 1B) according to one embodiment of the present invention, the fixing member (60, 60A) has two fixing parts (62) that are attached to the support plate (12) at different height positions in the hanging direction of the cable (40).

[7] The liquid level detection unit (1B) according to one embodiment of the present invention further includes an extension member (90) attached to the lower end of the support plate (12) in the hanging direction, a float-type other liquid level sensor (30B) supported to be able to float on the extension member (90) via the other cable (40B) and detecting that the liquid level has reached a predetermined liquid level, another cable guide member (50B) attached to the other cable (40B) and having an introduction section (53) where the other cable (40B) is introduced and an introduction section (54) where the other cable (40B) is introduced at a position where the extension direction of the introduced other cable (40B) is changed, and another fixing member (60B) that fixes the other cable guide member (50B) to the extension member (90).

[8] In one embodiment of the liquid level detection unit (1, 1A, 1B) of the present invention, a mounting plate (11) is provided that is attached to the drainage equipment (100) at a substantially right angle to the support plate (12) and covers the liquid level sensor (30, 30B) from the side of the drainage equipment (100).

Below, embodiments of the present invention will be described with reference to the drawings. In the following description, components common to the embodiments will be given the same reference numerals, and repeated description will be omitted. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. There may also be parts in which the dimensional relationships and ratios differ between the drawings.

The liquid level detection unit 1 according to this embodiment is characterized by comprising a float-type liquid level sensor 30 suspended via a cable 40 in a rainwater basin 100 to detect when the liquid level has reached a predetermined level, a support plate 12 supporting the liquid level sensor 30 so that it can float within the rainwater basin 100, a cable guide member 50 attached to the cable 40 and having an introduction section 53 into which the cable 40 is introduced and an outlet section 54 from which the cable is led out at a position where the extension direction of the introduced cable 40 is changed, and a fixing plate 60 for fixing the cable guide member 50 to the support plate 12 so that the outlet section 54 faces the side opposite the support plate 12. The liquid level detection unit 1 according to this embodiment will be described in detail below.

The liquid level detection unit 1 according to this embodiment is attached to the grating 200 of a drainage facility, such as a rainwater manhole 100 provided in a gutter that drains rainwater. FIG. 1A is a perspective view from above of the liquid level detection unit 1 according to one embodiment of the present invention attached to the grating 200. FIG. 1B is a perspective view from below of the liquid level detection unit 1 according to one embodiment of the present invention attached to the grating 200.

The liquid level detection unit 1 detects when water exceeds the allowable amount and enters the drainage equipment, causing the water level (liquid level) in the rainwater manhole 100 to reach a predetermined liquid level (hereinafter also referred to as the "warning liquid level"). The liquid level detection unit 1 is applied to, for example, a known rainwater manhole 100, and the rainwater manhole 100 to which it is applied is not limited to a specific rainwater manhole 100. For example, the liquid level detection unit 1 according to this embodiment is attached to a lattice-shaped grating 200 provided in the rainwater manhole 100.

[Liquid level detection unit]
2 is a perspective view of the liquid level detection unit 1 according to this embodiment. The liquid level detection unit 1 is attached to the grating 200 of the rainwater tank 100 from the inside. The liquid level detection unit 1 is attached to the grating 200 via a stainless steel fastener (not shown). The liquid level detection unit 1 includes a plate member 10, a liquid level detection switch (liquid level sensor 30, cable 40, cable guide member 50) 20, a fixing plate (fixing member) 60, and a power supply unit 70.

(Plate member)
3 is a perspective view of the plate member 10 of the liquid level detection unit 1 according to this embodiment, as viewed from below. The plate member 10 is made of synthetic resin or metal, and has a mounting plate 11 and a support plate 12. The plate member 10 is a member in which the mounting plate 11 and the support plate 12 are connected to each other so as to form an L-shape or a substantially L-shape. The mounting plate 11 and the support plate 12 are formed integrally with each other.

The mounting plate 11 of the plate member 10 is a plate member that is rectangular in plan view, and can be supported on the grating 200 via a stainless steel fastener (not shown). The mounting plate 11 has multiple insertion holes 111. Fasteners are passed through the insertion holes 111 and the plate member 10 is attached to the grating 200. The mounting plate 11 covers the liquid level sensor 30 (described later) from above in the hanging direction.

The support plate 12 of the plate member 10 is a rectangular plate member in a plan view, and is provided at a right angle to the mounting plate 11. The support plate 12 is formed integrally with the mounting plate 11 so that one short side of the support plate 12 abuts against the short side of the mounting plate 11. When the plate member 10 is attached to the grating 200 (hereinafter also referred to as the "attached state"), the support plate 12 extends vertically or approximately vertically to the grating 200. The liquid level sensor 30 is supported on the support plate 12 via a cable guide member 50 and a fixing plate (fixing member) 60, which will be described later, and the power supply unit 70 is attached to the support plate 12, for example, by a fastener such as a screw.

The support plate 12 has a plurality of holes 121, 122, 123. They are arranged in two rows at a predetermined interval in the short direction of the support plate 12, and each row has four holes 121 in the longitudinal direction. In each row, the four holes 121 are arranged at a predetermined interval in the longitudinal direction of the support plate 12.

In each row, a fastener such as a screw is inserted into adjacent holes 121 in the longitudinal direction of the support plate 12, and a fixing plate 60 (described later) is attached. Depending on the position of the hole 121 to which the liquid level detection switch 20 is attached, the position of the liquid level detection switch 20 can be freely changed according to the warning liquid level to be detected. Note that the number of holes 121 in each row is not particularly limited to four.

The support plate 12 further has two rows of holes 122 arranged at a predetermined interval in the short direction of the support plate 12, and each row has three holes 122 arranged in the longitudinal direction. In each row, the three holes 122 are arranged between the holes 121. A fastener such as a screw is inserted into one hole 122 located at the same position in the longitudinal direction of each row, and the power supply unit 70 is attached to the support plate 12.

The support plate 12 further has two holes 123 in the center or approximately in the center in the short direction of the support plate 12. The holes 123 are provided at a predetermined interval along the longitudinal direction below one row of holes 121 on the center side in the short direction of the support plate 12.

(Liquid level detection switch)
Fig. 4A is a perspective view for explaining the configuration of the liquid level detection switch 20. Fig. 4B is a front view of the liquid level detection switch 20. Fig. 4C is a cross-sectional view of the liquid level detection switch 20 as viewed from the front. Fig. 4C is a cross-sectional view of the liquid level detection switch 20 as viewed from the arrow C in Fig. 4B. The liquid level detection switch 20 has a liquid level sensor 30, a cable 40, and a cable guide member 50. The liquid level sensor 30 is a float type sensor. The liquid level sensor 30 is connected to the tip of the cable 40 and is electrically connected. As the liquid level rises, the liquid level sensor 30 detects the warning liquid level by tilting so that the base end 32 on the opposite side to the cable 40 approaches the tip 31 to which the cable 40 is connected in the hanging direction along the vertical direction.

The liquid level sensor 30 has a reed switch (not shown) and a magnet (not shown) inside a resin housing. The liquid level sensor 30 functions as a float, changing its inclination in conjunction with the up and down movement of the liquid level, opening and closing the switch contacts. The liquid level sensor 30 is not particularly limited, and any known float-type sensor can be used.

The liquid level sensor 30 is attached to the side where the mounting plate 11 extends relative to the support plate 12. In other words, the liquid level sensor 30 is located below the mounting plate 11 and is covered by the mounting plate 11.

The cross-sectional shape of the liquid level sensor 30 along the axis 30x passing through the center of the liquid level sensor 30 is teardrop-shaped or approximately teardrop-shaped. The cross-sectional shape of the liquid level sensor 30 intersecting the axis 30x is circular or approximately circular. The diameter of the cross-sectional shape of the liquid level sensor 30 increases continuously from the tip 31 side to which the cable 40 is attached toward the base end 32 along the axis 30x, and then converges toward the base end 32. The liquid level sensor 30 is switched on when the axis 30x extending from the tip 31 through the center of the base end 32 on the opposite side to the tip 31 in the hanging direction approaches a horizontal state, for example.

The cable 40 is formed by covering a conductive core with an insulating outer sheath such as polyethylene. One end of the cable 40 is electrically connected to the tip 31 of the liquid level sensor 30. The other end of the cable 40 is connected to a power supply unit 70 provided behind the support plate 12.

The cable guide member 50 is a flat resin member that is circular or nearly circular in plan view, and has a guide function for guiding the cable 40 and a function as a weight. The cable guide member 50 is attached to the cable 40 on the side of the tip 31 of the liquid level sensor 30.

When the liquid level detection switch 20 is supported on the support plate 12 via the fixing plate 60 described below (hereinafter also referred to as the "supported state"), a pair of side surfaces 51a facing in a direction along the axis 50x passing through the center of the cable guide member 50 extend vertically or approximately vertically, and the peripheral surface 51b extending in the circumferential direction is at least partially, for example, in line contact with the support plate 12.

The cable guide member 50 has a cable guide passage 52 therein. The cable guide passage 52 is a through passage formed penetrating the inside of the cable guide member 50. In the supported state, the cable guide passage 52 guides the cable 40 from above to below. The cable guide passage 52 has, on the peripheral surface 51b, an inlet (inlet section) 53 which is the starting point where the cable 40 is introduced into the inside of the cable guide member 50, and an outlet (outlet section) 54 which is the ending point where the cable 40 is led out from the cable guide member 50 to the outside. The inlet 53 and the outlet 54 are each provided approximately in the center of the width 50W along the axis 50x of the cable guide member 50.

In the supported state, the cable guide path 52 extends linearly along the vertical or nearly vertical direction toward the axis 50x of the cable guide member 50, and then extends linearly from near the axis 50x in directions approaching and moving away from the support plate 12.

The inlet 53 of the cable guide path 52 is a portion that opens upward in a vertical or approximately vertical direction in the supported state. The outlet 54 of the cable guide path 52 is located on the opposite side (lower side) of the inlet 53 in the supported state. The outlet 54 is provided at a position that changes the extension direction of the cable 40 that is introduced from the inlet 53 and extends in a vertical or approximately vertical direction. Specifically, the outlet 54 is provided at a position that is shifted in the circumferential direction from the position of the cable guide member 50 that is radially opposite the inlet 53, and is provided on the side facing the support plate 12 and the side opposite the support plate 12 in the supported state. In this embodiment, the cable 40 is led out from the outlet 54 provided on the side opposite the support plate 12.

A support member 55 is provided concentrically with the outlet 54. The support member 55 is a cylindrical member formed of a material such as resin. The support member 55 guides the cable 40 radially outward so that the cable 40 led out from the outlet 54 does not come into contact with the edge of the outlet 54. The liquid level sensor 30 moves via the cable 40 when the liquid level changes, starting from the contact point between the cable 40 and the support member 55.

Figure 5A is an oblique view of the fixed plate 60 as viewed from the outside. Figure 5B is an oblique view of the fixed plate 60 as viewed from the inside. Figure 5C is a plan view of the fixed plate 60. The liquid level detection switch 20 includes two (a pair of) fixed plates 60 as fixing members. Each of the fixed plates 60 is fixed to the support plate 12 so as to sandwich the cable guide member 50 from the side surface 51a.

The fixing plates 60 are made of a material such as metal or resin. In a plan view, the fixing plates 60 have a shape that is a rounded rectangle cut in half. In the supported state, the fixing plates 60 almost cover the side surface 51a of the cable guide member 50, and each fixing plate 60 is fixed at a right angle or almost a right angle to the support plate 12.

Each fixing plate 60 has an abutment portion 61, two fixing portions 62, and two engagement portions 63. In the supported state, the abutment portion 61 is the portion that contacts the side surface 51a of the cable guide member 50. In the supported state, the tip edge 61b of the abutment portion 61 on the side opposite the support plate 12 is rounded, and two extension portions 61a are formed on the edge of the abutment portion 61 on the side facing the support plate 12. The two extension portions 61a are portions that protrude from the abutment portion 61, and in the supported state, are provided on the support plate 12 at a predetermined interval from each other in the height direction H.

The fixing portion 62 is a portion formed at a right angle or approximately a right angle to the extending portion 61a. In the supported state, the two fixing plates 60 are attached to the support plate 12 so that the fixing portions 62 extend in different directions. A hole 62a is formed in each fixing portion 62. The fixing plate 60 is fixed to the support plate 12 by aligning the hole 62a of each fixing portion 62 with the hole 121 of the support plate 12 and inserting a fastener such as a specified screw through both holes 62a, 121.

The two engaging portions 63 are provided on the side of the rounded leading edge 61b of the abutment portion 61. In the supported state, the two engaging portions 63 on each fixing plate 60 are provided at a predetermined distance from each other in the height direction H. Here, the "height direction H" coincides with the longitudinal direction of the support plate 12 in the supported state. The engaging portions 63 include an upper engaging portion 63u in the supported state and a lower engaging portion 63d in the supported state. In the following description, when there is no need to distinguish between the upper engaging portion 63u and the lower engaging portion 63d, they will simply be referred to as "engaging portions 63".

The engagement portion 63 has a protrusion 63a and a claw portion 63b. The protrusion 63a is a portion that protrudes outward from the abutment portion 61 on the same plane. The claw portion 63b is located on the tip side of the protrusion 63a and forms a right angle or a nearly right angle with the protrusion 63a. In the supported state, the claw portion 63b abuts (engages) so as to face the peripheral surface 51b of the cable guide member 50. In other words, in the supported state, the engagement portion 63 presses the cable guide member 50 at its peripheral surface 51b against the support plate 12 by the claw portion 63b.

Figure 6 shows the state in which the fixing plate 60 is engaged with the cable guide member 50. In the supported state, the relatively upper engagement portion 63u is engaged with the peripheral surface 51b of the cable guide member 50 near the inlet 53 on the side opposite the support plate 12 with respect to the inlet 53 (see Figure 2). Specifically, the engagement portion 63u is provided within an angle range θ1 of, for example, about 40° from a position about 35° upward in the supported state to the side of the support plate 12 based on the line of symmetry 60l and the axis 50x that are linearly symmetrical with the fixing plate 60.

In the supported state, the lower engaging portion 63d engages with the peripheral surface 51b of the cable guide member 50 near the outlet 54 on the side of the support plate 12 relative to the outlet 54 (see FIG. 2). Specifically, the engaging portion 63d is provided within an angle range θ2 of, for example, about 40° from a position about 35° downward in the supported state to the side of the support plate 12 based on the line of symmetry 60l and the axis 50x. Note that, in the supported state, the lower engaging portion 63d in this embodiment is located on the side of the support plate 12 relative to the outlet 54, but may be located on the opposite side of the support plate 12 relative to the outlet 54 as long as it is within the above-mentioned angle range θ2.

Figure 7 is a diagram showing the assumed locations of contact of the liquid level sensor 30. The two imaginary circles Vc1 and Vc2 in the figure are imaginary circles of a sphere based on the maximum diameter D of the liquid level sensor 30. The positions of the two imaginary circles Vc1 and Vc2 show two examples of positions where the liquid level sensor 30 does not overlap with the cable 40 and may come into contact with the cable guide member 50.

The imaginary circle Vc1 shows the state in which the liquid level sensor 30 has risen and is in contact with the mounting plate 11. The imaginary circle Vc1 of the liquid level sensor 30 is in contact with the mounting plate 11 and the peripheral surface 51b of the cable guide member 50 facing the mounting plate 11. In the supported state, the engagement portion 63u of the fixed plate 60 is in a position that is off the tangent (contact point) between the imaginary circle Vc1 and the peripheral surface 51b of the cable guide member 50. In this state, the imaginary circle Vc1 does not come into contact with the engagement portion 63u of the fixed plate 60.

On the other hand, the imaginary circle Vc2 shows the state in which the liquid level sensor 30 has risen and is in contact with the support plate 12. The imaginary circle Vc2 of the liquid level sensor 30 is in contact with the support plate 12 and the peripheral surface 51b of the cable guide member 50 facing the side opposite the mounting plate 11. In the supported state, the engagement portion 63d of the fixing plate 60 is in a position that is off the tangent (contact point) between the imaginary circle Vc2 and the peripheral surface 51b of the cable guide member 50. In this state, the imaginary circle Vc2 does not come into contact with the engagement portion 63d of the fixing plate 60.

When the upper engaging portion 63u and the lower engaging portion 63d of the fixed plate 60 are provided in a position that satisfies the relationship between the above-mentioned angle ranges θ1 and θ2 and in a position that is off the tangent line between the imaginary circles Vc1 and Vc2 and the cable guide member 50, the liquid level sensor 30 does not come into contact with the upper engaging portion 63u and the lower engaging portion 63d of the fixed plate 60 even if the liquid level sensor 30 moves up and down in response to changes in the liquid level.

(Power supply)
The power supply unit 70 is attached to the support plate 12 on the side opposite to the liquid level sensor 30. The cable 40 is electrically connected to the power supply unit 70. The power supply unit 70 supplies power to the liquid level sensor 30 via the cable 40. The power supply unit 70 has a connection portion 71 (see FIG. 2). The power supply unit 70 and the cable 40 are electrically connected at the connection portion 71.

(Fluid level sensor operation)
The warning liquid level detected by the liquid level sensor 30 is set arbitrarily at a position spaced a predetermined distance from the grating 200 along the hanging direction of the liquid level sensor 30. When the liquid level reaches the warning liquid level, it is an indication that there is a risk of water overflowing from the grating 200, for example.

For example, the liquid level sensor 30 is designed to detect the liquid level at a predetermined height from the base end 32. The hanging position of the liquid level sensor 30 can be changed appropriately by adjusting the position of the liquid level detection switch 20 attached to the support plate 12. This allows a predetermined height position from the base end 32 passing through the axis 30x to correspond to an arbitrarily set alert liquid level.

As the amount of rain flowing in through the grating 200 increases, the liquid level reaches the base end 32 of the liquid level sensor 30, causing the liquid level sensor 30 to float up. The liquid level sensor 30, together with the portion of the cable 40 extending from the outlet 54 of the cable guide member 50, tilts and floats up away from the support plate 12.

The mass of the liquid level sensor 30 is greater than the buoyancy. In the liquid level sensor 30, the center of buoyancy is on the base end 32 side, and the center of gravity of the liquid level sensor 30 is located on the tip end 31 side. Due to the misalignment between the center of buoyancy and the center of gravity, a rotational moment is generated in the liquid level sensor 30. Due to the generation of the rotational moment, as the liquid level rises, the tip 31 of the liquid level sensor 30 tilts, and the tip 31 and base end 32 of the liquid level sensor 30 approach each other in the hanging direction, and the axis 30x approaches horizontal or approximately horizontal.

For example, when the liquid level reaches the warning level and the axis 30x of the liquid level sensor 30 exceeds a predetermined angle, the reed switch turns on and the liquid level sensor 30 transmits a signal to an external device to warn that the liquid level in the rainwater manhole 100 has reached the warning level.

The liquid level detection unit 1 described above makes it possible to accurately detect the warning liquid level. If the cable guide member 50 is not provided, the liquid level sensor 30 may vibrate due to the vibration of the cable 40, causing the detection position to shift. In contrast, in the liquid level detection unit 1 according to this embodiment, the cable guide member 50 that guides the cable 40 is attached to the support plate 12 by the fixed plate 60. Therefore, even if the part of the cable 40 that is free on the upstream side of the cable guide member 50 is vibrated significantly, for example, by incoming wind or flowing water, the adverse effects of this vibration are not transmitted to the liquid level sensor 30 that is connected to the part of the cable 40 downstream of the cable guide member 50.

In addition, if the cable guide member 50 is fixed directly to the support plate 12, external disturbances such as strong winds will act on the cable guide member 50. In this case, a large load will also be placed on the fixed portion of the cable guide member 50 relative to the support plate 12, which may cause the fixed portion to be damaged. In contrast, in the liquid level detection unit 1 according to this embodiment, the cable guide member 50 is clamped between a pair of separate fixing plates 60 and fixed to the support plate 12, so that the cable guide member 50 can be fixed more stably to the support plate 12.

Furthermore, the cable guide member 50 is pressed against the support plate 12 at two points, one above and one below, in the hanging direction of the cable 40 by the engagement portion 63 of the fixing plate 60. The engagement portion 63 makes it possible to maintain the position of the cable guide member 50 relative to the support plate 12 even if at least one fastener in one of the fixing portions 62 of the fixing plate 60 becomes loose. Furthermore, the cable guide member 50 is stably held at three points, the two points by the engagement portion 63 and one contact point with the support plate 12, making it possible to accurately detect the alert liquid level.

Furthermore, since the engagement portions 63 are provided at different height positions in the hanging direction of the cable 40, the cable guide member 50 can be more stably fixed to the support plate 12 from above and below in the height direction H.

Furthermore, since the engaging portion 63 is provided near the outlet 53, for example, even if the liquid level sensor 30 is shaken, the liquid level sensor 30 can be prevented from colliding with the engaging portion 63, reducing the possibility of damage to the liquid level sensor 30. When the liquid level sensor 30 comes into contact with the abutment portion 61 of the fixed plate 60, the contact is on a surface, whereas when the liquid level sensor 30 comes into contact with a portion of the engaging portion 63, the liquid level sensor 30 may come into contact with an edge that follows the shape of the engaging portion 63. Therefore, it is important from the viewpoint of damage to the liquid level sensor 30 to provide the engaging portion 63 at a position where it will not come into contact even if the liquid level sensor 30 is shaken, thereby avoiding contact between the liquid level sensor 30 and the engaging portion 63.

Furthermore, when the mounting plate 11 is attached to the grating 200, it covers the liquid level sensor 30 from above. As a result, for example, when rainwater flows into the rainwater basin 100, the mounting plate 11 becomes a so-called roof, and the effect of the flowing rainwater on the detection of the liquid level by the liquid level sensor 30 can be minimized.

<Modifications of the Fixing Plate>
In the above embodiment, the fixing member includes a pair of fixing plates 60, but may be a single fixing plate 60A. Fig. 8A is a perspective view of a liquid level detection unit 1A including a fixing plate 60A according to a modified example, seen from one side. Fig. 8B is a perspective view of a liquid level detection unit 1A including a fixing plate 60A according to a modified example, seen from the other side. Below, the parts different from the fixing plate 60 will be mainly described, and the same parts as the fixing plate 60 will be denoted by the same reference numerals and description thereof will be omitted. The fixing plate 60A is provided only on one side surface 51a of the cable guide member 50, and is not provided on the other side surface 51a.

Figure 9 is a perspective view of a fixed plate 60A according to a modified example. The fixed plate 60A has an abutment portion 61, two fixing portions 62, and two engagement portions 63A. In the supported state, the abutment portion 61 is a portion that contacts one side surface 51a of the cable guide member 50. In the supported state, the edge of the abutment portion 61 on the side opposite the support plate 12 is rounded, and two extension portions 61a are formed on the edge of the abutment portion 61 on the side facing the support plate 12. In the supported state, the two extension portions 61a are each provided at a predetermined interval from each other in the height direction H.

The two engagement portions 63A are provided on the rounded tip edge 61b of the abutment portion 61. In the supported state, the two engagement portions 63A on the fixed plate 60A are provided at a predetermined distance from each other in the height direction H.

In the supported state, the engagement portion 63A includes an upper engagement portion 63Au and a lower engagement portion 63Ad. In the following description, when there is no need to distinguish between the upper engagement portion 63Au and the lower engagement portion 63Ad, they will simply be referred to as "engagement portion 63A."

The engagement portion 63A has a protrusion 63Aa, a claw portion 63Ab, and a folded portion 63Ac. The protrusion 63Aa is a portion that protrudes outward from the abutment portion 61 on the same plane. The claw portion 63Ab is located on the tip side of the protrusion 63Aa and forms a right angle or a nearly right angle with the protrusion 63Aa. In the supported state, the claw portion 63Ab abuts (engages) so as to face the peripheral surface 51b of the cable guide member 50. In other words, in the supported state, the engagement portion 63A presses the cable guide member 50 at its peripheral surface 51b toward the support plate 12 by the claw portion 63Ab.

The folded portion 63Ac is located at the tip side of the claw portion 63Ab on the side opposite the protruding portion 63Aa. The folded portion 63Ac extends in a direction facing the protruding portion 63Aa at a right angle or a nearly right angle to the claw portion 63Ab. In the supported state, the folded portion 63Ac abuts against the side surface 51a of the cable guide member 50 on the side that is not abutted by the fixed plate 60A. In other words, in the fixed plate 60A, it is sandwiched between the abutment portion 61 and the folded portion 63Ac.

The liquid level detection unit 1A equipped with the modified fixed plate 60A can also achieve the same effect as that achieved by the liquid level detection unit 1.

Second Embodiment
10 is a perspective view showing a liquid level detection unit 1B according to the second embodiment. Below, the following mainly describes the parts that are different from the liquid level detection unit 1 according to the first embodiment, and the same parts as those in the liquid level detection unit 1 are denoted by the same reference numerals and will not be described.

The liquid level detection unit 1B according to the second embodiment includes a plate member 10, two liquid level detection switches 20, 80, two sets of fixed plates (fixing members) 60, 60B, a power supply unit 70, and an extension frame 90. Of the two liquid level detection switches 20, 80, the first liquid level detection switch 20 is fixed to the support plate 12 of the plate member 10, and the other, the second liquid level detection switch 80, is provided below the first liquid level detection switch 20.

The liquid level detection switch 80 in the second embodiment has a liquid level sensor 30B, a cable 40B, and a cable guide member 50B. The liquid level sensor 30B, cable 40B, and cable guide member 50B of the second liquid level detection switch 80 have the same configurations as the liquid level sensor 30, cable 40, and cable guide member 50 of the first liquid level detection switch 20, respectively. In the second embodiment, the cable guide member 50B is attached to the mounting plate 91 by being sandwiched between a pair of fixing plates 60B.

The extension frame 90 is manufactured from, for example, a metal such as aluminum or a resin such as plastic. For example, the cross-sectional shape of the extension frame 90 perpendicular to the longitudinal direction is rectangular or approximately rectangular. On each side, the extension frame 90 has a T-slot. A pre-insertion nut (not shown) is inserted into the T-slot. At one end of the extension frame 90, the pre-insertion nut is aligned with a hole 123 formed on the lower end side of the support plate 12, and the extension frame 90 is connected by a fastener such as a screw.

A mounting plate 91 is provided at the other end of the extension frame 90. The mounting plate 91 can be attached at a position corresponding to the position of a pre-inserted nut (not shown) inserted into the T-slot of the extension frame 90. According to the liquid level detection unit 1B of the second embodiment, the mounting plate 91 can be freely attached to the extension frame 90 along its longitudinal direction. This allows the second liquid level detection switch 80 to set another liquid level to be detected below the first liquid level detection switch 20 attached to the support plate 12.

The liquid level detection unit 1B according to the second embodiment can achieve the same effects as the liquid level detection unit 1 according to the first embodiment. Furthermore, the second liquid level detection switch 80 can detect an increase in the liquid level early, for example, before the liquid level reaches the warning level detected by the first liquid level detection switch 20. The second liquid level detection switch 90 can set a preliminary warning level, so that a warning can be issued at an earlier stage in drainage equipment around facilities such as hospitals and nursing homes where evacuation takes time.

＜Other＞
Although the preferred embodiments and modifications of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments and modifications, and includes all aspects included in the concept of the present invention and the scope of the claims. In addition, each configuration may be appropriately and selectively combined so as to achieve at least a part of the above-mentioned problems and effects. In addition, for example, the shape, material, arrangement, size, etc. of each component in the above-mentioned embodiments and modifications may be appropriately changed depending on the specific usage mode of the present invention.

DESCRIPTION OF SYMBOLS 1, 1A, 1B: Liquid level detection unit 10: Plate member 11: Mounting plate, 12: Support plate 20, 80: Liquid level detection switch 30: Liquid level sensor, 40: Cable, 50: Cable guide member, 53: Inlet (inlet portion), 54: Outlet (inlet portion), 60, 60A: Fixing plate (fixing member), 63, 63A: Engagement portion 70: Power supply device 90: Extension frame (extension member)
100...Rainwater manhole (drainage facility)

Claims (7)

A float-type liquid level sensor that is suspended via a cable inside the drainage equipment and detects when the liquid level reaches a predetermined level;
a support plate that supports the liquid level sensor in the drainage facility so that the liquid level sensor can float;
a cable guide member attached to the cable, the cable guide member having an introduction portion into which the cable is introduced and an introduction portion that introduces the cable at a position where an extension direction of the introduced cable is changed;
a fixing member that fixes the cable guide member to the support plate such that the lead-out portion faces a side opposite to the support plate;
Equipped with
the fixing member includes a pair of fixing plates attached to the support plate in parallel to each other so as to sandwich the cable guide member therebetween,
Each of the fixing plates has at least two engaging portions that engage with the cable guide member on a side where the lead-out portion is provided, and press the cable guide member against the support plate.
A liquid level detection unit for drainage equipment. A float-type liquid level sensor that is suspended via a cable inside the drainage equipment and detects when the liquid level reaches a predetermined level;
a support plate that supports the liquid level sensor in the drainage facility so that the liquid level sensor can float;
a cable guide member attached to the cable, the cable guide member having an introduction portion into which the cable is introduced and an outlet portion that outlets the cable at a position where an extension direction of the introduced cable is changed;
a fixing member that fixes the cable guide member to the support plate such that the lead-out portion faces a side opposite to the support plate;
Equipped with
The fixing member is a fixing plate attached to the support plate,
The one fixing plate has at least two engaging portions which engage with the cable guide member on a side where the lead-out portion is provided and engage with the cable guide member on a side opposite to the side with which the one fixing plate comes into contact, thereby pressing the cable guide member against the support plate.
A liquid level detection unit for drainage equipment. 3. The liquid level detection unit for drainage equipment according to claim 1 , wherein the engagement portions are provided at different height positions in a hanging direction of the cable. The liquid level detection unit for drainage equipment according to any one of claims 1 to 3 , characterized in that one engagement portion is provided between the outlet portion and the support plate in the vicinity of the inlet portion and the outlet portion. The liquid level detection unit for drainage equipment according to any one of claims 1 to 4 , characterized in that the fixing member has fixing portions that are attached to the support plate at different height positions in the hanging direction of the cable. an extension member attached to a lower end of the support plate in a hanging direction;
Another float-type liquid level sensor is supported on the extension member via another cable so as to be able to float, and detects when the liquid level reaches a predetermined liquid level;
Another cable guide member is attached to the other cable, and has an introduction portion into which the other cable is introduced and an outlet portion from which the other cable is led out by changing an extension direction of the introduced other cable;
another fixing member that fixes the other cable guide member to the extension member;
The liquid level detection unit for use in drainage equipment according to any one of claims 1 to 5 , further comprising : A liquid level detection unit for a drainage equipment described in any one of claims 1 to 6 , characterized in that it is provided with a mounting plate that is arranged approximately perpendicular to the support plate so as to be attachable to the drainage equipment and covers the liquid level sensor from the side of the drainage equipment.

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