Float for water level detection

Abstract

To provide a float for water level detection that relatively reduces a contact face of the float with an inner wall surface of a breakwater pipe to reduce the resistance against displacement in the vertical direction of the float.SOLUTION: A float 1 for water level detection is accommodated such that a gap S is formed over the entire circumference between a side face 2a of a main body 2 and an inner wall surface 5a of a breakwater pipe 5. The float for water level detection has contact parts 7, at an end on one side and an end on the other side in an axial direction of the main body 2, which can be brought into contact with the inner wall surface 5a of the breakwater pipe 5 so as to be displaced inside the breakwater pipe 5 while maintaining the gap S over the entire circumference between the side face 2a of the main body 2 and the inner wall surface 5a of the breakwater pipe 5. The contact parts 7 are a plurality of projections 8 arranged side by side along the circumferential direction of the main body 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a structure of a float for water level detection housed in a breakwater pipe, which is used, for example, in a water level difference meter used for operations such as starting a dust collector or a water level meter for detecting the water level on the upstream side of a dam.

Background Art

[0002] For example, in a dust collector for removing dust and the like in a water channel, as shown in Patent Document 1, a water level difference meter for detecting the water level difference between the upstream side and the downstream side with respect to a screen for blocking dust installed in the water channel by the difference between the positions of the upstream float and the downstream float is arranged. When dust accumulates on the upstream side of the screen and the water level difference between the upstream side and the downstream side of the screen is detected, the dust collector may be started to remove the dust on the upstream side of the screen in the water channel.

[0003] And, in order to eliminate the influence of waves on the water surface, the two floats of the water level difference meter may be respectively housed in breakwater pipes and used. Each float may have a disk-like shape, for example, as shown in Patent Document 2, and it is sufficient that there is a gap between its side surface and the inner wall surface of the breakwater pipe. However, due to the relationship of the installation space of the water level difference meter, etc., as shown in Patent Document 1, it may be a relatively elongated float and may be configured to be housed in a relatively elongated breakwater pipe.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when a relatively elongated float is housed in a relatively elongated breakwater pipe, the annular gap between the float's side and the inner wall of the breakwater pipe is narrow. Due to the surface tension of the water between the float's side and the inner wall of the breakwater pipe, the float's side may adhere to the inner wall of the breakwater pipe, potentially slowing down the float's vertical displacement. As a result, even though the water level difference between the upstream and downstream sides of the screen has been eliminated, the water level meter may detect a water level difference, causing the debris remover to start or continue operating, potentially leading to a malfunction of the debris remover.

[0006] This problem, where the side of the float adheres to the inner wall of the breakwater pipe, slowing down the float's vertical displacement, is problematic even in water level gauges equipped with a single float to detect the water level upstream of a dam, as it leads to inaccurate water level detection results.

[0007] In this regard, Figure 1 of Patent Document 1 shows protrusions extending radially from both the upper and lower ends in the longitudinal direction of the float housed in the breakwater pipe. However, the aforementioned protrusions of the float in Patent Document 1 are only located at two symmetrical locations in the radial direction of the float. Moreover, in Figure 2(c) of Patent Document 1, the lower part of the breakwater pipe is open, and the lower part of the float is exposed to the water outside the breakwater pipe. As a result, at least in the state shown in Figure 2(c) of Patent Document 1, even if the float has protrusions at its upper and lower ends in the longitudinal direction, the surface tension of the water may cause the side surface of the float to come into contact with the inner wall surface of the breakwater pipe. Therefore, Patent Document 1 does not provide motivation for the present invention.

[0008] In view of the above problems, the present invention primarily aims to provide a water level detection float that can reduce resistance to vertical displacement of the float by relatively reducing the contact surface between the float and the inner wall surface of the breakwater pipe. [Means for solving the problem]

[0009] To achieve the above objectives, the water level detection float of the present invention is A water level detection float having an axially elongated cylindrical body, housed within an erected cylindrical breakwater pipe, and displacing within the breakwater pipe in response to changes in water level to detect the water level, wherein the body is housed such that a gap is formed around its entire circumference between the side surface of the body and the inner wall surface of the breakwater pipe, and the body has at least two contact portions at its axial location that can contact the inner wall surface of the breakwater pipe while maintaining the gap around its entire circumference between the side surface of the body and the inner wall surface of the breakwater pipe, and the contact portions are a plurality of rotating bodies arranged along the circumferential direction of the body and rotating in the direction of displacement, the rotating bodies having a biconical shape with two conical portions joined at their bases, and having an axle rod passing through the vertices of the two conical portions as a mechanism for rotating the rotating bodies, the axle rod being rotatably supported between two vertical wall portions erected from the side surface of the body of the float. and It is characterized by the following (Claim 1). The two locations in the axial direction of the main body are, for example, one end and the other end in the axial direction of the main body, but either or both of the rotating body may be located towards the center in the axial direction of the main body.

[0010] Thus, in the water level detection float of the present invention, As the float displaces within the breakwater pipe due to changes in water level, the contact portion, which consists of multiple rotating bodies aligned along the circumferential direction of the main body and rotating in the direction of the float's displacement, comes into contact with the inner wall surface of the breakwater pipe, thus reducing the relatively small contact surface with the inner wall surface of the breakwater pipe.

[0011] Furthermore, the float for detecting the water level of the present invention is A water level detection float having an axially elongated cylindrical body, housed in an upright cylindrical breakwater pipe, and displacing within the breakwater pipe in response to changes in water level to detect the water level, wherein the float is housed such that a gap is formed around its entire circumference between the side surface of the body and the inner wall surface of the breakwater pipe, and has a contact portion that can abut against the inner wall surface of the breakwater pipe so as to displace within the breakwater pipe while maintaining the gap around its entire circumference along the axial direction of the body, the contact portion being a plurality of linear members having a wave-like portion with repeating peak-like and valley-like portions, wherein the peak-like portions abut against the inner wall surface of the breakwater pipe and the valley-like portions abut against the side surface of the float (Claim 2). The linear members are, for example, wire. Along the axial direction of the body means, for example, from one end of the body in the axial direction to the other end.

[0012] Thus, in the water level detection float of the present invention, when it is displaced inside the breakwater pipe due to a change in water level, the contact portion, which consists of multiple linear members having wave-like portions with repeating peak-like and valley-like sections, has the peak-like portions in contact with the inner wall surface of the breakwater pipe, so that the contact surface with the inner wall surface of the breakwater pipe becomes relatively small.

[0013] A float for detecting water levels has an axially elongated cylindrical body and is housed in an upright cylindrical breakwater pipe. The float detects water levels by displacing within the breakwater pipe in response to changes in water level. The float is housed such that a gap is formed around its entire circumference between the side surface of the body and the inner wall surface of the breakwater pipe. The body has contact portions at least two locations in its axial direction that can contact the inner wall surface of the breakwater pipe, allowing it to displace within the breakwater pipe while maintaining the gap around its entire circumference between the side surface of the body and the inner wall surface of the breakwater pipe. These contact portions may be a plurality of protrusions arranged along the circumferential direction of the body.

[0014] In this water level detection float, when it displaces inside the breakwater pipe due to changes in water level, the contact portion, which consists of multiple protrusions arranged along the circumference of the main body, comes into contact with the inner wall surface of the breakwater pipe, thus making the contact surface with the inner wall surface of the breakwater pipe relatively small. [Effects of the Invention]

[0015] As described above, in the water level detection float of the present invention, when the float is displaced inside the breakwater pipe due to a change in water level, the part that comes into contact with the inner wall surface of the breakwater pipe is not the side surface of the float body, but a contact portion provided on the float body. Therefore, the contact surface with the inner wall surface of the breakwater pipe becomes relatively smaller, and it becomes possible to reduce the resistance of the float body to displacement inside the breakwater pipe. [Brief explanation of the drawing]

[0016] [Figure 1] This is an explanatory diagram showing a first example of an embodiment of the water level detection float of the present invention, where (a) is a side view of the water level detection float and (b) is a top view of the water level detection float. [Figure 2] This is an explanatory diagram illustrating the schematic of a water level difference meter for a dust removal machine using a float for water level detection as shown in Figure 1, and further shows a state where there is no water level difference between the upstream and downstream sides of the screen. [Figure 3]FIG. 0 is an explanatory view showing an outline of a water level differential meter for a dust collector using the float for water level detection in FIG. 1, similar to FIG. 2, and further shows a state where a water level difference occurs between the upstream side and the downstream side of the screen. [Figure 4] FIG. 3 is an explanatory view showing a second example among the embodiments of the float for water level detection of the present invention, where (a) is a side view of the float for water level detection, and (b) is a plan view of the float for water level detection. [Figure 5] FIG. 6 is an explanatory view showing a third example among the embodiments of the float for water level detection of the present invention, where (a) is a side view of the float for water level detection, and (b) is a plan view of the float for water level detection.

MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0018] (First Example) In FIGS. 1 to 3, a first example of an embodiment of a float 1 for water level detection to which this invention is applied (hereinafter, simply abbreviated as float 1) is shown. The float 1 is configured to have a main body 2 and a suspension fitting 3 for suspending the main body 2. For the suspension fitting 3, for example, an eye nut or an eye bolt is used.

[0019] The float 1 is also referred to as a buoy. The main body 2 is formed of a material that can float in water, has an axially long cylindrical shape, and is hollow. As shown by the imaginary line in FIG. 1(b) and FIGS. 2 and 3, the float 1 is housed in a surge pipe 5 described later and is used in a state where at least the lower part of the main body 2 floats on the water surface. When the float 1 is housed in the surge pipe 5, as shown by the imaginary line in FIG. 1(b), it can be housed so that an annular gap S is formed over the entire circumference between the side surface 2a of the main body 2 and the inner wall surface 5a of the surge pipe 5. In the first example, the dimension of the gap S is less than about 5 mm.

[0020] Furthermore, the float 1 has contact portions 7 at two locations in the axial direction of the main body 2 that can contact the inner wall surface 5a of the breakwater pipe 5 in order to displace inside the breakwater pipe 5 while maintaining a gap S around its entire circumference between the side surface 2a of the main body 2 and the inner wall surface 5a of the breakwater pipe 5. In the first example, the contact portions 7 are a number of projections 8 (five on each side, totaling 10) arranged along the circumferential direction of the main body 2, at one end (upper end) and the other end (lower end) in the axial direction of the main body 2, as shown in Figure 1. The projections 8 are, for example, roughly hemispherical in shape, with only the top surface contacting the inner wall surface 5a of the breakwater pipe 5. Note that the number of projections 8 shown in Figure 1 is just an example; any number of projections 8 that function as contact portions 7 as described above is acceptable. For example, there could also be four or six projections arranged at one end and the other end in the axial direction of the main body 2. Furthermore, when the projections 8 are provided at the upper and lower ends of the main body 2, the float 1 and the breakwater pipe 5 are configured such that even when the main body 2 is at its lowest point due to changes in water level, the side surface 2a of the float 1 at the lower end of the main body 2 faces the inner wall surface 5a of the breakwater pipe 5. The projections 8 can be located at two (or more) points along the axial direction of the main body 2, and the float 1 can be positioned at points where the side surface 2a of the main body 2 of the float 2 abuts against the inner wall surface 5a of the breakwater pipe 5.

[0021] Furthermore, in the first example of this embodiment, a fastener 81 having a head 82 with a larger outer diameter than the threaded shaft portion (not shown) is attached to the side surface 2a of the main body 2, and the substantially hemispherical head 82 constitutes the projection 8. For example, screws or bolts (Phillips screws) are used for the fastener 81. Furthermore, the fastener 81 is made of a material that is resistant to rust in water, for example, stainless steel. Note that something other than the head 82 of the fastener 81 may be used to constitute the projection 8. In the first example, the projection 8 protrudes less than 5 mm from the side surface 2a of the main body 2, corresponding to the dimension of the gap S described above. That is, the five projections 8 arranged in a line along the circumferential direction on the side surface 2a of the main body 2 and the inner wall surface 5a may not only be in constant contact, but there may also be a slight gap so that when the float 1 is displaced inside the breakwater pipe 5, one of the five projections 8 contacts the inner wall surface 5a before the side surface 2a of the main body 2 contacts the inner wall surface 5a.

[0022] Next, an example of a measuring device in which the float 1 described above is used is a water level difference meter 100 as shown in Figures 2 and 3. In Figures 2 and 3, the water level difference meter 100 detects the difference in water level between the upstream and downstream sides of a screen 200 installed in a waterway WW to block debris, and sends the detected signal to a debris remover (not shown) to start the debris remover or to keep the debris remover running.

[0023] An example of the configuration of the water level difference meter 100 will be outlined using Figures 2 and 3. In Figures 2 and 3, a float 1 for detecting the water level upstream of the screen 200 (hereinafter referred to as the upstream float 1) is positioned upstream of the screen 200, and a float 1 for detecting the water level downstream of the screen 200 (hereinafter referred to as the downstream float 1) is positioned downstream of the screen 200. In Figures 2 and 3, the upstream float 1 and the downstream float 1 are housed in vertically erected cylindrical breakwater pipes 5. The gap S between the side surface 2a of the body 2 of these floats 1 and the inner wall surface 5a of the breakwater pipe 5, and the projection 8 as the contact part 7 are as described above.

[0024] Furthermore, in Figures 2 and 3, a water intake 51 is formed at the bottom of the breakwater pipe 5 so that the water level in the upstream breakwater pipe 5 is the same as the water level upstream of the screen 200, and the water level in the downstream breakwater pipe 5 is the same as the water level downstream of the screen 200. However, although not shown in the figures, for example, a pair of breakwater pipes 5, 5 could be placed close together on either side of the screen 200 without being separated, and water upstream of the screen 200 could be introduced into one breakwater pipe 5 by a water intake pipe, and water downstream of the screen 200 could be introduced into the other breakwater pipe 5 by a water intake pipe so that the water level in one breakwater pipe 5 is the same as the water level upstream of the screen 200, and the water level in the other breakwater pipe 5 is the same as the water level downstream of the screen 200.

[0025] The upstream float 1 has a wire 101 attached to a suspension fitting 3. The wire 101 is guided above the base 103 by a pulley 104 located below the base 103, which is mounted on the housing 102, and a pulley 105 located above the base 103. Furthermore, beyond the pulley 105, a weight 106 is connected to the wire, guiding it downwards. Due to the displacement of the upstream float 1, the weight 106 moves up and down to move closer to the pulley 105. A limit switch 107 is provided on a predetermined part of the surface of the weight 106 that will be described later, on the side of the weight 112.

[0026] The downstream float 1 has a wire 110 attached to a suspension fitting 3. The wire 110 is guided above the base 103 by a pulley 111 located above the base 103, and further guided downwards by a weight 112 connected beyond the pulley 111. Due to the displacement of the downstream float 1, the weight 112 moves up and down to move closer to the pulley 111.

[0027] As a result, when the water level is the same upstream and downstream of the screen 200, as shown in Figure 2, and then, as shown in Figure 3, the water level downstream of the screen 200 drops while the water level upstream of the screen 200 remains unchanged, the downstream float 1 is displaced downward inside the breakwater pipe 5, and the weight 112 is displaced upward so that it approaches the pulley 111, i.e., the limit switch 107 of the weight 106. Consequently, as shown in Figure 3, when the weight 112 approaches the limit switch 107 of the weight 106 to a predetermined distance, the limit switch 107 is activated, sending a signal to a dust removal machine (not shown), which starts the dust removal machine, and debris is removed from the upstream side of the screen 200 by the rake and other devices of the dust removal machine. If the weight 112 remains close to the limit switch 107, the signal to the dust removal machine will continue to be sent, and the dust removal machine will continue to operate.

[0028] For these reasons, smooth vertical displacement of the float 1 within the breakwater pipe 5 is required. In this invention, when the float 1 is displaced vertically within the breakwater pipe 5 due to changes in water level, the part that contacts the inner wall surface 5a of the breakwater pipe 5 is not the side surface 2a of the body 2 of the float 1, but rather the projection 8, which is a contact part 7 provided on the body 2. As a result, the contact surface between the float 1 and the inner wall surface 5a of the breakwater pipe 5 becomes relatively smaller, and the resistance to the vertical displacement of the float 1 is reduced. Thus, the side surface 2a of the body 2 of the float 1 is prevented from adhering to the inner wall surface 5a of the breakwater pipe 5 due to water, which would slow down the vertical displacement of the float 1. In other words, the risk of the debris removal machine malfunctioning due to the water level difference between the upstream and downstream sides of the screen 200 being incorrectly transmitted to the debris removal machine is avoided.

[0029] Although Figures 2 and 3 show a water level difference meter 100 using a pair of floats 1, 1 as an example of a measuring device in which float 1 is used, the present invention is not limited to such a water level difference meter 100. Although not shown, the present invention is also applicable to water level meters that use a single float 1, such as a water level meter for detecting the water level of a dam pond, if the float 1 has an axially elongated cylindrical body 2, is housed in an erected cylindrical breakwater pipe 5, and the gap between the side surface 2a of the body 2 and the inner wall surface 5a of the breakwater pipe 5 is narrow enough for adhesion by water to occur.

[0030] (Second example) Figure 4 shows a second example of an embodiment of the float 1 to which this invention is applied. The float 1 shown in Figure 4 has multiple rotating bodies 9 (five at one end of the float 1 and five at the other end, for a total of 10) as contact portions 7 provided at two locations in the axial direction of the main body 2, instead of the projection 8 shown in the first example in Figure 1. The number of rotating bodies 9 shown in Figure 4 is just one example; they only need to have the function of contact portions 7 as described above in the first example. For example, arrangements with four or six rotating bodies at one end and six at the other end of the main body 2 in the axial direction are also acceptable.

[0031] The rotating body 9 has a shape resembling two cones (frustums of a cone) joined at their bases (like the beads on an abacus, a biconical shape). The mechanism for rotating the rotating body 9 includes a shaft 10 that passes through the vertices of the two cones. This shaft 10 is rotatably supported between two vertical walls 11, 11 that rise from the side surface 2a of the main body 2. These rotating body 9, shaft 10, and vertical walls 11 are made of a material resistant to rust from water, such as stainless steel. As a result, when the float 1 is displaced vertically within the breakwater pipe 5 due to changes in water level, the contact point with the inner wall surface 5a of the breakwater pipe 5 is not the side surface 2a of the main body 2 of the float 1, but rather the rotating body 9, specifically the joint between the bases of the two cones (frustums of a cone), which is the contact point 7 provided on the main body 2. Therefore, the contact surface between the float 1 and the inner wall surface 5a of the wave-breaking pipe 5 becomes relatively small, and furthermore, because the rotating body 9 rotates on the inner wall surface 5a, it becomes possible to reduce the resistance to vertical displacement of the float 1.

[0032] The positional relationship between the side surface 2a and the inner wall surface 5a of the breakwater pipe 5 when the rotating body 9 is provided at the upper and lower ends of the main body 2, and the position of the rotating body 9, is the same as in the first example, as long as it is in a location where the side surface 2a of the main body 2 of the float 2 abuts against the inner wall surface 5a. Furthermore, the five rotating bodies 9 arranged in a line along the circumferential direction on the side surface 2a of the main body 2 and the inner wall surface 5a may not only be in constant contact, but there may also be a slight gap so that when the float 1 is displaced inside the breakwater pipe 5, one of the five rotating bodies 9 abuts against the inner wall surface 5a before the side surface 2a of the main body 2 abuts against the inner wall surface 5a, also the same as in the first example. The rotating bodies 9 can also be located in three places in the axial direction of the main body 2 of the float 1, for example, at the upper end, the middle part, and the lower end.

[0033] (Third example) Figure 5 shows a third example of an embodiment of the float 1 to which this invention is applied. The float 1 shown in Figure 5 has multiple linear members 13 (five in Figure 5) as contact parts 7 provided along the axial direction of the main body, instead of the projection 8 of the first example shown in Figure 1 and the rotating body 9 of the second example shown in Figure 4. The number of linear members 13 shown in Figure 5 is just one example; they only need to have the function of contact parts 7 as described above in the first example. For example, four or six members can be arranged at one end and the other end of the main body 2 in the axial direction.

[0034] In Figure 5, the linear member 13 is provided from one end to the other end in the axial direction of the main body and is shown as a wire consisting of straight sections on both sides and a wavy section between these straight sections that repeats peak-like and valley-like shapes. The peak-like sections of the linear member 13 are shown in both Figures 5(a) and (b), and the straight sections are shown in Figure 5(b). However, the valley-like sections are hidden by the band 14 used to fix the linear member 13 to the side surface 2a of the main body 2 of the float 1, so the peak-like section 13a and the straight section 13b are indicated by reference numerals in Figure 5. The linear member 13 is made of a material that is resistant to rust caused by water, such as stainless steel. The band 14 is also made of a material that is resistant to deterioration and corrosion caused by water. As a result, when the float 1 is displaced vertically within the breakwater pipe 5 due to changes in water level, the part that contacts the inner wall surface 5a of the breakwater pipe 5 is not the side surface 2a of the main body 2 of the float 1, but rather the mountain-shaped portion 13a of the linear member 13, which is the contact portion 7 provided on the main body 2. Therefore, the contact surface between the float 1 and the inner wall surface 5a of the breakwater pipe 5 becomes relatively smaller, making it possible to reduce the resistance to vertical displacement of the float 1.

[0035] Similar to the first and second examples, the mountain-shaped portions 13a of the five linear members 13 and the inner wall surface 5a may not only be in constant contact, but may also be slightly separated so that when the float 1 is displaced inside the breakwater pipe 5, one of the mountain-shaped portions 13a of the five linear members 13 contacts the inner wall surface 5a before the side surface 2a of the main body 2 contacts the inner wall surface 5a. [Explanation of symbols]

[0036] 1. Float (float for detecting water level) 2 Main unit 2a side 5 Breakwater tube 5a Inner wall surface 7 Contact part 8 Protrusion 81 Fixtures 82 Head 9. Solids of revolution 13 Linear members 13a Mountain part S gap

Claims

1. A water level detection float having an axially elongated cylindrical body, housed within an erected cylindrical breakwater pipe, and displacing within the breakwater pipe in response to changes in water level to detect the water level, The main body is housed such that a gap is formed around its entire circumference between the side surface of the main body and the inner wall surface of the wave-breaking pipe. The main body has at least two contact portions in the axial direction that are capable of contacting the inner wall surface of the breakwater pipe so as to be displaced inside the breakwater pipe while maintaining a gap around the entire circumference between the side surface of the main body and the inner wall surface of the breakwater pipe, The aforementioned contact portion is a plurality of rotating bodies arranged along the circumferential direction of the main body and rotating in the direction of displacement, The rotating body has a biconical shape formed by joining two conical parts at their bases, and a mechanism for rotating the rotating body has a shaft that passes through the vertices of the two conical parts, the shaft being rotatably supported between two vertical walls erected from the side surface of the float body, and is a float for detecting water levels.

2. A water level detection float having an axially elongated cylindrical body, housed within an erected cylindrical breakwater pipe, and displacing within the breakwater pipe in response to changes in water level to detect the water level, The main body is housed such that a gap is formed around its entire circumference between the side surface of the main body and the inner wall surface of the wave-breaking pipe. The main body has a contact portion that can abut against the inner wall surface of the breakwater pipe, so as to be displaced along the axial direction of the main body while maintaining a gap around the entire circumference between the side surface of the main body and the inner wall surface of the breakwater pipe, The abutment portion is a plurality of linear members having a wave-like shape with repeating peak-like and valley-like sections, wherein the peak-like sections abut against the inner wall surface of the breakwater pipe and the valley-like sections abut against the side surface of the float, characterized in that the float is a water level detection float.

Images