Lid unit

Abstract

To provide a lid unit that maintains the intended structural strength as a lid while stably outputting radio signals from inside an existing housing to the outside of the housing without interference. [Solution] The lid unit 10 is attached to the opening 2a of the existing housing 2 and consists of a metal lid periphery portion 20 that extends in a planar manner to cover the opening 2a of the housing 2 and forms part of a lid having a substantially circular opening 21, and a lid radio wave transparent portion 50 that is placed on the opening 21 of the lid periphery portion 20, has radio wave transparency and forms the remaining part of the lid which is substantially circular in shape when viewed from above. This allows it to withstand the load of a vehicle or the like, and to stably output radio waves from inside the existing housing to the outside of the housing without interference.

Description

Technical Field

[0001] The present invention relates to a lid unit attached to an opening of a housing that houses a water meter or the like.

Background Art

[0002] Conventionally, as a method for water meter reading, a method using a smart meter that can transmit usage data measured by a water meter called a waterway meter to a water utility company by wireless communication has been devised.

[0003] A water meter generally consists of a housing device including a housing and a lid placed on a lid placement portion formed at the upper surface opening of the housing, or a housing device including a housing, a lid placement frame integrally fixed to the upper surface opening of the housing, and a lid placed on the lid placement frame. Therefore, when performing meter reading using a smart meter, it is necessary to install a wireless communication unit for transmitting usage data by wireless signal inside the housing device. However, for example, when the lid is made of metal, the radio waves output from the wireless communication unit are reflected by the metal lid, resulting in interference with wireless communication.

[0004] Therefore, in place of the conventional metal lid, a proposal has been made to place a resin lid having radio wave permeability on an existing housing so that radio waves can pass through the lid (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the case of the cover described in Patent Document 1, although it transmits radio wave signals, the cover is roughly rectangular in shape to conform to the plan view shape of the existing housing, so there was a risk of radio wave interference occurring at the four corners. Also, since the entire cover is made of resin, it needs to be thick enough to maintain strength to withstand the load of a vehicle, etc., which affected the storage space inside the housing.

[0007] This invention addresses these problems and aims to provide a lid unit that can stably output radio waves from inside an existing housing to the outside of the housing without interference, while maintaining the intended structural strength of the lid. [Means for solving the problem]

[0008] To solve the above problems, the lid unit of the present invention is A metal periphery of the lid is attached to the opening of an existing housing, extends in a planar manner to cover the opening of the housing, and forms part of a lid having a substantially circular opening, The lid radio wave transparent portion, which is placed on the opening in the periphery of the lid, has radio wave transparency, and forms the remaining part of the lid that is formed in a substantially circular shape in plan view, It is characterized by being composed of [this]. This feature allows the lid to withstand the load of vehicles, etc., by forming a metal perimeter as part of the lid, and by using a radio wave-transmitting lid portion as the remaining part of the lid, radio wave signals output from inside the existing casing can be stably output to the outside of the casing without interference. In particular, because the radio wave-transmitting lid portion is circular in shape, radio wave signals can be output without bias, and internal stress caused by the load of vehicles, etc., can be widely distributed without localized concentration.

[0009] The area of ​​the periphery of the lid in a plan view is larger than the area of ​​the radio wave-transmitting portion of the lid in a plan view. This feature means that the area around the metal lid is larger than the area of ​​the lid that transmits radio waves, thus increasing the overall structural strength of the lid.

[0010] The lid is characterized by having a retaining portion at the lower part of the periphery that can move forward and backward toward the inner surface of the housing. This feature allows the periphery of the lid to be held in place by the housing, and also allows the periphery of the lid to be removed.

[0011] The retaining portion is characterized by being provided near the opening in the periphery of the lid. This feature allows the retaining part to be easily moved forward and backward while the lid is attached to the housing.

[0012] The radio wave-transmitting portion of the cover is characterized in that it is supported around the cover via a sealing member. This feature ensures that the space between the radio wave-transmitting portion of the cover and the surrounding area of ​​the cover is sealed, preventing the intrusion of rainwater and other liquids.

[0013] The aforementioned radio wave-transmitting portion of the cover is characterized in that it is detachably mounted approximately vertically above the surrounding portion of the cover. This feature makes it easy to remove the radio wave-transmitting portion of the cover.

[0014] The lower surface of the periphery of the lid is characterized by having a substantially annular mounting portion on which the radio wave-transmitting portion of the lid can be mounted, protruding along the periphery of the opening. This feature allows the mounting portion to protrude downward from the periphery of the opening, thereby increasing the structural strength of the area around the lid.

[0015] The inner surface of the mounting portion is characterized by having a straight surface extending downward and a tapered surface extending downward from the straight surface in the direction of expanding diameter. This feature allows the sealing member to be properly press-fitted, making it less likely for the radio wave-transmitting part of the lid, which is placed on the opening around the lid, to come off, thus improving the airtightness.

[0016] The holding part is characterized by consisting of bolts that are screwed in and out in the lower part of the peripheral part of the lid body. According to this feature, not only can the holding operation of the peripheral part of the lid body be easily performed, but bolts with high versatility can also be easily procured.

Brief Description of the Drawings

[0017] [Figure 1] It is a cross-sectional view showing the state where the water measuring box is buried in the ground. [Figure 2] (a) is a perspective view showing the upper surface of the peripheral part of the lid body as viewed obliquely from the front upper side, and (b) is a perspective view showing the lower surface of the peripheral part of the lid body as viewed obliquely from the front upper side. [Figure 3] (a) is a cross-sectional view taken along the line A-A of FIG. 2(a), and (b) is an enlarged cross-sectional view of the main part of FIG. 3(a). [Figure 4] It is a bottom view with a partial break showing the relationship between the peripheral part of the lid body and the housing. [Figure 5] (a) is a plan view showing the radio wave transmission part of the lid body, (b) is a cross-sectional view taken along the line B-B of FIG. 5(a), and (c) is a bottom view showing the radio wave transmission part of the lid body. [Figure 6] It is a plan view showing the lid body unit. [Figure 7] It is a cross-sectional view taken along the line C-C of FIG. 6. [Figure 8] (a) is a cross-sectional view showing the state where the radio wave transmission part of the lid body is removed from the opening of the peripheral part of the lid body, and (b) is a cross-sectional view showing the state where the peripheral part of the lid body and the radio wave transmission part of the lid body are removed from the housing.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the lid body unit according to the present invention will be described below based on examples.

Examples

[0019] The lid unit of this embodiment will be described with reference to Figures 1 to 8. Hereinafter, when viewing Figure 1 from the front, the left and right sides will be the left and right sides of the lid unit and housing, the front side will be the front side of the lid unit and housing, and the back side will be the rear side of the lid unit and housing.

[0020] As shown in Figure 1, for example, a water meter box 1 (also called a meter box) is buried underground in a residential plot, and inside the water meter box 1, a part of a water pipe 11, a water meter 12 (also called a water meter) connected to the water pipe 11, and a stopcock 13 connected to the water meter 12 are buried.

[0021] The water meter box 1 comprises a bottomed box-shaped housing 2 with an opening 2a that is roughly rectangular in plan view formed at its upper end, a cast iron lid mounting frame 3 integrally fixed to the opening 2a of the housing 2 via adhesive or the like, and a lid unit 10, which will be described later. The housing 2 and the lid mounting frame 3 integrated with the housing 2 constitute the housing of the present invention. The housing 2 is formed in a bottomed box shape from concrete material with side walls and a bottom wall, and water pipes 11 are inserted through openings 2b, 2b formed in the left and right side walls.

[0022] The water meter 12 is capable of measuring water usage, and a wireless communication unit 15 housed inside the casing 2 is connected to it by wiring C. The usage data measured by the water meter 12 is transmitted to the wireless communication unit 15, which then transmits the data to a base station, for example, via wireless communication, and from the base station, etc., it is transmitted to a data management server of a water utility company, etc., via a communication line. Alternatively, the usage data measured by the water meter 12 may be transmitted to the wireless communication unit 15 via wireless communication, or a reading device (not shown) that reads usage data from the meter of the water meter 12 may be attached to the water meter 12, and the reading device may transmit the read usage data to the wireless communication unit 15.

[0023] [Lid unit] As shown in Figure 1, the lid unit 10 is placed on a lid mounting frame 3 fixed to the opening 2a of the existing housing 2 and consists of a cast iron lid peripheral portion 20 that forms part of the lid and a lid radio wave transparent portion 50 that is radio wave transparent, is formed in a substantially circular shape in plan view and forms the remaining part of the lid.

[0024] As shown in Figures 2(a), (b) and 3(a), (b), the periphery portion 20 of the lid is formed in a roughly rectangular shape in plan view, substantially the same shape as the upper end surface of the housing 2, with a circular opening 21 extending vertically through the center. Multiple protrusions 22 extending in the front-rear direction are formed on the upper surface 20a at predetermined intervals in the left-right direction.

[0025] A lid mounting portion 23, which forms a roughly annular shape in plan view, is projected downward from the periphery of the opening 21 on the lower surface 20b of the lid periphery portion 20. The inner circumferential surface 21a of the opening 21 hangs vertically downward and extends to a position below the lower surface 20b of the lid periphery portion 20.

[0026] The inner surface of the cover mounting portion 23 has a mounting surface 23a that extends substantially horizontally in the inner diameter direction from the lower end of the inner circumferential surface 21a of the opening 21, a vertical surface 23b formed at a position lower and on the inner diameter side than the mounting surface 23a, and a tapered surface 23c that gradually slopes outward from the lower end of the vertical surface 23b. The opening 21 is closed by the cover radio wave transparent portion 50 when the circumferential end of the cover radio wave transparent portion 50 is placed on the mounting surface 23a.

[0027] As shown in Figures 3(a), (b) and 4, a plurality of retaining bodies 24 (four in this example) are provided protruding from the opening 21 on the lower surface 20b of the lid perimeter 20 for fixing the lid perimeter 20 to the housing 2. Each retaining body 24 is roughly rectangular in shape and mainly consists of a base portion 25 arranged radially outward from the left and right sides of the front and rear of the lid mounting portion 23, a through hole 26 formed through the base portion 25 in the longitudinal direction, a fixing bolt 27 inserted into the through hole 26 from the outer diameter end so as to be rotatable around the axis, a nut housing portion 28 formed on the lower surface of the base portion 25 and communicating with the through hole 26, and a nut 29 that is housed in the nut housing portion 28 and screwed onto the fixing bolt 27 inserted into the through hole 26.

[0028] Furthermore, the nut housing section 28 has internal restricting means (not shown) for restricting the rotation of the housing nut 29 around its axis, and its bottom surface is open, allowing the nut 29 to be removed by detaching it from the fixing bolt 27, thus enabling the fixing bolt 27 and nut 29 to be replaced.

[0029] The fixing bolts 27 inserted into each through-hole 26 are positioned substantially parallel to the periphery 20 of the lid and inclined with respect to the front edge 20c and rear edge 20d of the periphery 20 of the lid. Furthermore, the inner end face 27a of the fixing bolt 27 has a square hole (not shown) into which a tool such as a square wrench (not shown) can be inserted, and the bolt can be moved axially by inserting the square wrench (not shown) into the square hole (not shown) and rotating it. Note that the fixing bolts 27 may be rotated with other tools such as a screwdriver instead of a square wrench, or by hand.

[0030] As shown in Figures 2(b) and 3(a), protrusions 30, 30 extending in the front-rear direction are provided on the left and right sides of the lower surface 20b of the lid perimeter 20. The protrusions 30, 30 are positioned inward from the left edge 20e and right edge 20f of the lid perimeter 20, and are positioned inward from the left and right side walls when placed on the upper surface of the lid mounting frame 3, which is the upper end surface of the housing, thereby restricting the lateral movement of the lid perimeter 20.

[0031] When fixing the lid perimeter 20 to the opening 2a at the top of the housing 2, first, rotate each fixing bolt 27 so that its outer end surface 27b (see Figure 4) is positioned inside the front edge 20c and rear edge 20d of the lid perimeter 20 (see the position of the fixing bolts 27 shown by the dashed lines in Figure 4). Next, as shown in Figure 4, place the lid perimeter 20 so as to close the opening 2a at the top of the housing 2 and adjust its installation position relative to the housing 2. Once the installation position is determined, insert a square wrench (not shown) into the opening 21 that is open from above the lid perimeter 20, insert it into the square hole (not shown) formed in the inner end surface 27a of each fixing bolt 27, and rotate it to move the fixing bolt 27 outwards (in the direction indicated by the arrows in Figure 4).

[0032] Then, the outer end faces 27b of each fixing bolt 27 are brought into contact with the inner surfaces of the front and rear walls of the housing 2, and while adjusting the position of the lid perimeter 20 relative to the upper end surface of the housing 2, the outer end faces 27b of each fixing bolt 27 are pressed against the inner surfaces of the front and rear walls of the housing 2. Since the fixing bolts 27 are arranged radially, not only is the movement of the lid perimeter 20 relative to the housing 2 restricted in the front-to-back direction, but its movement in the left-to-right and upward directions is also restricted, preventing the lid perimeter 20 from unexpectedly coming off the housing 2.

[0033] Furthermore, when placing the periphery portion 20 of the lid onto the lid mounting frame 3 of the housing 2, a waterproofing material such as caulking material may be provided between the periphery portion 20 of the lid and the lid mounting frame 3 of the housing 2 to seal and prevent the intrusion of rainwater, etc.

[0034] Next, the radio wave transparent portion 50 of the lid will be described based on Figures 5(a) to 5(c). In this embodiment, the radio wave transparent portion 50 of the lid is made of polyvinyl chloride resin and is formed in a plate shape that is slightly smaller than the opening 21 of the lid's peripheral portion 20 and has a roughly circular shape in plan view. In addition, reinforcing ribs 52 are provided protruding from the lower surface 50b, and an annular sealing member 53 made of polyethylene resin in this embodiment is provided on the outer circumference of the ribs 52.

[0035] The sealing member 53 is composed of an attachment portion 53a that is attached to the outer circumference of the rib 52 and faces vertically, and a sealing portion 53b that is formed to fold upward from the lower end of the attachment portion 53a and widen toward the outer diameter, and is formed in a roughly L-shape in cross-section. In other words, the sealing member 53 is formed so that the sealing portion 53b on the outer diameter side can be elastically deformed toward the inner diameter side.

[0036] Multiple recesses 54 (for example, three) are formed at predetermined intervals on the outer circumferential surface of the radio wave-transmitting portion 50 of the lid. By inserting a tool (not shown) into the recesses 54 and manipulating the tool in a lever manner, the radio wave-transmitting portion 50 of the lid can be easily removed, thereby opening the opening 21 of the periphery portion 20 of the lid.

[0037] The rib 52 is composed of an outer rib 52a formed in an annular shape near the outer circumference of the radio wave transparent portion 50 of the cover, an inner rib 52b formed in an annular shape on the inner diameter side of the outer rib 52a, and a plurality of connecting ribs 52c that connect the outer rib 52a and the inner rib 52b, and a sealing member 53 is fitted around the outer circumferential surface of the outer rib 52a.

[0038] As shown in Figures 6 and 7, when the radio wave-transmitting part 50 of the lid is placed on the opening 21 formed in the lid periphery 20, the opening 21 is closed. More specifically, since the mounting surface 23a of the lid mounting part 23 is formed at a position lower than the upper surface 20a of the lid periphery 20 by the thickness of the radio wave-transmitting part 50 of the lid, when the radio wave-transmitting part 50 of the lid is fitted into the opening 21 from above the lid periphery 20, the peripheral edge of the lower surface 20b of the lid periphery 20 is placed on the mounting surface 23a of the lid mounting part 23, so that the upper surface 50a of the radio wave-transmitting part 50 and the upper surface 20a of the lid periphery 20 are supported in a position where they are substantially flush.

[0039] Furthermore, when the lid's radio wave-transmitting portion 50 is fitted into the opening 21, the sealing portion 53b of the sealing member 53 is guided downward by the vertical surface 23b of the lid mounting portion 23 and deforms (reduces in diameter) toward the inner diameter. Subsequently, when it slides against the tapered surface 23c below the vertical surface 23b, it expands in diameter due to elastic restorative force while moving downward. Then, with the peripheral edge of the lower surface 20b of the lid's peripheral portion 20 placed on the mounting surface 23a of the lid mounting portion 23, the upper part of the sealing portion 53b is pressed against the tapered surface 23c of the lid mounting portion 23 in the circumferential direction. As a result, the space between the inner surface of the opening 21 of the lid's peripheral portion 20 and the lid's radio wave-transmitting portion 50 is sealed, preventing the intrusion of rainwater, etc., thus preventing the wireless communication unit 15 from being submerged by rainwater flowing into the housing 2. In addition, since the sealing member 53 is formed in an annular shape and does not have any bent parts, it has high sealing performance.

[0040] Furthermore, the vertical surface 23b of the lid mounting portion 23 allows the sealing portion 53b to be properly press-fitted, and the tapered surface 23c below it inclines upward toward the inner diameter, i.e., shrinks in diameter, while the sealing portion 53b inclines upward toward the outer diameter, i.e., expands in diameter. This makes it difficult for the lid radio wave transparent portion 50 placed on the opening 21 to come off, thereby improving the sealing performance.

[0041] Furthermore, the lid unit 10 is composed of a cast iron lid periphery 20 and a polyvinyl chloride resin lid radio wave transparent portion 50. As shown in Figures 6 and 7, the lid periphery 20 has a rectangular frame-shaped frame region E1 (shaded area in Figure 6) that is placed on the upper surface of the lid mounting frame 3 when attached to the upper end of the peripheral wall of the housing 2, and a planar region E2 (shaded area in Figure 6) that extends inward from the frame region E1 so as to cover the opening 2a of the housing 2.

[0042] The area ratio of the lid perimeter 20 and the lid radio wave transparent section 50 in a plan view is approximately 3:1, meaning that the area of ​​the lid perimeter 20 in a plan view is larger than the area of ​​the lid radio wave transparent section 50 in a plan view. In other words, approximately 3 / 4 of the total area of ​​the lid unit 10 is composed of the lid perimeter 20 made of cast iron with high structural strength, and the remaining approximately 1 / 4 is composed of the lid radio wave transparent section 50 made of polyvinyl chloride resin with radio wave transparency. This allows the structural strength of the entire lid unit 10 to withstand loads such as vehicles, while stably outputting radio signals from the wireless communication unit 15 installed inside the housing 2 to the outside through the polyvinyl chloride resin lid radio wave transparent section 50, which is constructed to the minimum necessary size.

[0043] Furthermore, because the radio wave-transmitting section 50 of the lid is circular in shape, radio waves can be output without bias regardless of the installation position of the wireless communication unit 15 inside the housing 2, and internal stress caused by the load of a vehicle or the like can be widely distributed without being concentrated locally.

[0044] Furthermore, when installing the lid unit 10 on the upper end surface of the housing 2, as shown in Figure 8(a), the lid periphery 20 is positioned in the opening 2a of the housing 2, the lid radio wave transparent portion 50 is removed upward from the opening 21, and the internal fixing bolts 27 are rotated from the opening 21 to press against the housing 2, thereby fixing the lid periphery 20 to the housing 2.

[0045] Since the water usage data measured by the water meter 12 is transmitted wirelessly from the wireless communication unit 15 to an external base station or the like, there is no need to visually check the meter of the water meter 12 to measure the usage data. Therefore, the radio wave transparent section 50 of the lid only needs to be large enough to allow a tool to be inserted when installing the periphery 20 of the lid into the opening 2a of the housing 2, and thus can be made as small as possible.

[0046] Furthermore, if inspection, repair, or replacement of the water meter 12, wireless communication unit 15, etc. inside the housing 2 becomes necessary due to long-term use, the radio wave transparent section 50 of the lid can be removed upward from the opening 21, and the internal fixing bolts 27 can be rotated from the opening 21 to separate them from the housing 2. Then, as shown in Figure 8(b), the radio wave transparent section 50 of the lid and the surrounding section 20 of the lid can be removed upward from the opening 2a to widely open the entire opening 2a, making inspection, repair, and replacement work easy.

[0047] [Effects and Effects] As described above, the lid unit 10 as an embodiment of the present invention consists of a metal lid periphery portion 20 that is attached to the opening 2a of an existing housing 2, extends in a planar manner to cover the opening 2a of the housing 2, and forms a part of the lid having a substantially circular opening 21, and a lid radio wave transparent portion 50 that is placed on the opening 21 of the lid periphery portion 20, has radio wave transparency, and forms the remaining part of the lid that is formed in a substantially circular shape when viewed from above.

[0048] According to this, by forming a metal periphery portion 20 as part of the lid, it can withstand the load of a vehicle, etc., and by using a radio wave transparent lid portion 50 as the remaining part of the lid, radio wave signals output from inside the existing housing 2 can be stably output to the outside of the housing 2 without interference. In particular, because the radio wave transparent lid portion 50 is circular in shape, radio wave signals can be output without bias, and internal stress caused by the load of a vehicle, etc., can be widely distributed without localized concentration.

[0049] Furthermore, the area of ​​the lid perimeter 20 in plan view is larger than the area of ​​the lid radio wave transparent portion 50 in plan view. Since the area of ​​the metal lid perimeter 20 is larger than that of the lid radio wave transparent portion 50, the overall structural strength of the lid unit 10 can be increased. On the other hand, the resin lid radio wave transparent portion 50 is circular and smaller than the lid perimeter 20, so structural strength can be ensured without forming it to be thick.

[0050] Furthermore, a fixing bolt 27 is provided at the lower part of the lid perimeter 20, which serves as a retaining part that can move back and forth toward the inner surface of the housing 2. This allows the lid perimeter 20 to be held in place by the housing 2, and also allows the lid perimeter 20 to be removed from the housing 2.

[0051] Furthermore, since the fixing bolts 27, which serve as retaining parts, are provided near the opening 21 of the lid periphery 20, the fixing bolts 27 can be easily moved forward and backward while the lid periphery 20 is attached to the housing 2.

[0052] Furthermore, by forming the base portion 25 that holds the fixing bolt 27 near the opening 21 of the lid periphery 20, the structural strength of the lid periphery 20 near the opening 21 can be increased.

[0053] Furthermore, the radio wave-transmitting portion 50 of the lid is supported by the surrounding portion 20 of the lid via a sealing member 53, thereby sealing the space between the radio wave-transmitting portion 50 and the surrounding portion 20 of the lid, preventing the intrusion of rainwater and the like. In this embodiment, the space between the radio wave-transmitting portion 50 of the lid and the surrounding portion 20 of the lid was sealed via a sealing member 53, but it is not necessarily required to be sealed by a sealing member 53.

[0054] Furthermore, the radio wave-transmitting section 50 of the lid is detachably mounted approximately vertically above the surrounding section 20 of the lid, making it easy to remove the radio wave-transmitting section 50 of the lid.

[0055] Furthermore, a substantially annular lid mounting portion 23, on which the lid radio wave transparent portion 50 can be placed, is provided projecting along the periphery of the opening 21 on the lower surface 20b of the lid periphery portion 20, thereby increasing the structural strength of the lid periphery portion 20. In addition, the mounting surface 23a, which extends substantially horizontally, can support the load applied to the upper surface of the lid radio wave transparent portion 50.

[0056] Furthermore, the inner surface of the lid mounting portion 23 has a vertical surface 23b as a straight surface extending downward and a tapered surface 23c extending downward in the radially expanding direction from the vertical surface 23b. This allows the sealing member 53 to be properly press-fitted, making it less likely for the lid radio wave transparent portion 50 placed on the opening 21 of the lid peripheral portion 20 to come off, thereby improving the sealing performance.

[0057] Furthermore, since the holding portion consists of a fixing bolt 27 that is screwed into the lower part of the periphery of the lid so as to be able to move back and forth, not only is the holding operation of the periphery of the lid 20 made easy, but a highly versatile bolt can also be easily procured.

[0058] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0059] For example, in the above embodiment, the housing 2 was shown to be made of concrete, but the present invention is not limited to this, and may be made of other materials such as metal. Also, although a metal lid mounting frame 3 was integrally fixed to the opening 2a of the housing 2, the lid mounting frame 3 may be made of a material other than metal, or it is not necessarily required to have a lid mounting frame 3. Furthermore, a lid mounting portion may be pre-formed at the upper end of the housing 2. In other words, the housing of the present invention may consist only of the housing 2, or it may include a lid mounting frame 3, a lid mounting portion, etc. Also, although the opening 2a of the housing 2 was formed in a substantially rectangular shape in plan view, it is not limited to a rectangular shape, and may be formed in a square shape, polygonal shape, or circular shape.

[0060] Furthermore, although the above embodiment illustrates a configuration in which an opening 21 is formed in the center of the periphery 20 of the lid, the present invention is not limited thereto, and an opening may be formed in a region other than the center of the periphery 20 of the lid. Moreover, although one opening 21 was formed in the periphery 20 of the lid, multiple openings may be formed, and a radio wave transmitting portion of the lid may be placed in each opening.

[0061] Furthermore, in the above embodiment, the opening 21 was formed to a size that allowed a tool to be inserted into the square hole of the fixing bolt 27. However, the outer diameter of the opening 21 is arbitrary and may be changed according to the frequency band and wavelength of the radio waves transmitted by the wireless device such as the wireless communication unit 15. It may even be smaller than the outer diameter of the opening 21 as long as radio wave transparency can be ensured.

[0062] Furthermore, in the above embodiment, a configuration was illustrated in which the area of ​​the lid periphery 20 in plan view is larger than the area of ​​the lid radio wave transparent portion 50 in plan view. However, the present invention is not limited thereto. As long as radio waves from inside the housing 2 can be output to the outside through the lid radio wave transparent portion, the area of ​​the lid periphery 20 in plan view may be approximately the same as or smaller than the area of ​​the lid radio wave transparent portion 50 in plan view. Note that the area ratio of the lid periphery 20 and the lid radio wave transparent portion 50 in plan view is not limited to approximately 3:1 and can be changed as desired.

[0063] Furthermore, although the above embodiment illustrates a form in which the opening 21 is formed in a circular shape in plan view, the present invention is not limited thereto, and as long as it is substantially circular in plan view, it may be formed in a polygonal shape, and the shape can be changed in various ways.

[0064] Furthermore, although the above embodiment illustrates a form in which the lid radio wave transparent portion 50 is made of polyvinyl chloride resin, the present invention is not limited thereto, and any material that has radio wave transparency may be used, such as synthetic resins other than polyvinyl chloride resin or materials other than synthetic resins. Also, the sealing member 53 does not have to be polyethylene resin, and may be made of other synthetic resins or materials other than synthetic resins.

[0065] Furthermore, in the above embodiment, a fixed bolt 27, which serves as a retaining part that can move back and forth toward the inner surface of the housing 2, is provided near the opening 21 at the lower part of the lid perimeter 20. However, the present invention is not limited to this, and the retaining part for holding the lid perimeter 20 to the housing 2 may be provided at a position away from the opening 21. Or, it may not necessarily be provided at all.

[0066] Furthermore, although the above embodiment illustrates a configuration in which the wireless communication unit 15 is located on the inner bottom surface of the housing 2, the present invention is not limited thereto. A support portion for supporting the wireless communication unit 15 may be provided on the periphery 20 of the lid, and the wireless communication unit 15 may be supported by the support portion at a position above the bottom surface of the housing 2.

[0067] Although several embodiments and modifications thereof of the present invention have been described, it is also possible to combine each embodiment and each modification as appropriate without departing from the spirit of the present invention. For example, the housing may house devices other than a water meter. [Explanation of Symbols]

[0068] 1. Water meter box 2 cabinets 2a Opening (opening in the housing) 2b opening 3. Lid mounting frame (housing) 10 Lid Unit 11 Water pipes 12 Water meter 15 Wireless communication unit 20 Peripheral part of the lid 21 Opening 23 Lid mounting section (mounting section) 23a Mounting surface 23b Vertical surface (straight surface) 23c tapered surface 24 Holding body 25 Base section 27 Fixing bolt (holding part) 29 nuts 50 Cover radio wave transmitting part 52 Ribs 53 Sealing member 53a Mounting part 53b Seal section E1 Border Area E2 Planar area

Claims

1. A metal periphery of the lid is attached to the opening of an existing housing, extends in a planar manner to cover the opening of the housing, and forms part of a lid having a substantially circular opening, The lid radio wave transparent portion, which is placed on the opening in the periphery of the lid, has radio wave transparency, and forms the remaining part of the lid that is formed in a substantially circular shape in plan view, A lid unit characterized by being made of the following:

2. The lid unit according to claim 1, characterized in that the area of ​​the periphery of the lid in a plan view is larger than the area of ​​the radio wave transparent portion of the lid in a plan view.

3. The lid unit according to claim 1, characterized in that a retaining portion that can move forward and backward toward the inner surface of the housing is provided at the lower part of the periphery of the lid.

4. The lid unit according to claim 3, characterized in that the retaining portion is provided near the opening in the periphery of the lid.

5. The lid unit according to claim 1, characterized in that the radio wave transmitting portion of the lid is supported around the lid via a sealing member.

6. The lid unit according to any one of claims 1 to 5, characterized in that the radio wave transmitting portion of the lid is detachably mounted substantially vertically above the surrounding portion of the lid.

Images