JP2005221359A - Gas meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and inexpensive gas meter with a waterproof structure. <P>SOLUTION: A vent channel with a labyrinth structure for carrying out ventilation between the outside and inside of a case 10 is made up of a front face of the case 10 which has an aperture 11b, and a rear face of a front cover 20 opposite to the front face. The labyrinth structure R is made up by engaging a recess 11d which is formed by a projection 11c disposed in the front face making up the vent channel, with a projection 27 disposed in the rear face of the front cover 20 opposite to the front face. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas meter incorporating a pressure sensor, for example.

  In recent years, in order to improve the safety of gas equipment, a gas meter has a built-in pressure sensor, and the built-in pressure sensor is used to measure the pressure of the passing gas. Some have the function of shutting off the supply. Since the pressure sensor detects the differential pressure between the passing gas pressure and the atmospheric pressure as the passing gas pressure, a gas meter with a built-in pressure sensor vents the atmospheric pressure to the atmospheric pressure side of the pressure sensor at any location. It is necessary to provide a road.

  By the way, since there are electrical components inside the meter in addition to the pressure sensor, it is necessary to provide a water-resistant structure so that water does not enter from the air passage. Therefore, conventionally, a water-resistant structure is formed by passing through a plurality of air passages, using a resin lid at the inlet, or using a special film that does not allow water to pass but allows air to pass. For this reason, the gas meter is increased in size, and additional parts such as a resin lid and a special film are required, which causes a problem in terms of cost.

  Therefore, the present invention pays attention to the above-described problems, and an object thereof is to provide a gas meter having a compact and inexpensive water-resistant structure.

  The invention according to claim 1 is a gas meter that accommodates a flow rate measurement unit and has a housing in which an opening is formed on a part of one surface and a cover that covers the one surface, and the opening of the housing is The gas meter is characterized in that an air passage having a labyrinth structure that ventilates the outside and the inside of the housing is formed by the provided one surface and the back surface of the cover facing the one surface.

  According to the first aspect of the present invention, the labyrinth air passage that ventilates the outside and the inside of the housing is formed by the one surface provided with the opening of the housing and the back surface of the cover facing the one surface. Therefore, by using a labyrinth structure for the air passage formed by the housing and the cover, water or the like can be prevented from entering the housing without using additional parts such as a resin film or a special film. .

  The invention according to claim 2 is the gas meter according to claim 1, wherein the gas meter is provided on any one of the one surface provided with the opening for forming the air passage and the back surface of the cover facing the one surface. A gas meter is characterized in that a concave portion formed by a convex portion and a convex portion provided on the other are fitted to form a labyrinth structure.

  According to the second aspect of the present invention, the concave portion formed by the convex portion provided on one of the one surface provided with the opening forming the air passage and the back surface of the cover facing the one surface, and the other The provided convex portion is fitted to form a labyrinth structure. Therefore, the labyrinth structure can be formed with a simple configuration in which a convex portion is formed on the one surface provided with the opening and the back surface of the cover.

  A third aspect of the present invention is the gas meter according to the second aspect, wherein the surface of the convex portion arranged vertically upward is inclined closer to the vertical lower side toward the end of the surface. It exists in the gas meter characterized by being provided.

  According to invention of Claim 3, the surface arrange | positioned toward the perpendicular | vertical upward direction of a convex part is attached | subjected the inclination which approaches a vertically lower side as it goes to the edge part of the surface. Therefore, by inclining the surface that is arranged vertically upward, the water flows down and drains vertically along the inclination toward the end, so that water flows into the inside of the ventilation path of the labyrinth structure. There is no accumulation.

  Invention of Claim 4 is the gas meter of Claim 2, Comprising: The surface arrange | positioned along the perpendicular direction of the said convex part or a recessed part faces the said convex part or recessed part as it goes to the perpendicular downward direction. The gas meter is characterized by being inclined away from the housing or the cover.

  According to a fourth aspect of the present invention, in the gas meter according to the second aspect, the surface of the convex portion or the concave portion that is arranged along the vertical direction faces the vertically downward direction, and the casing is opposed to the convex portion or the concave portion. Or it is tilted away from the cover. Therefore, by inclining the surface arranged along the vertical direction, gravity is applied in the direction away from the surface of the water drops attached to the surface arranged along the vertical direction. Since the water droplets are separated from the surface to be disposed and drained, water does not collect inside the labyrinth structure air passage.

  A fifth aspect of the present invention is the gas meter according to the second aspect, wherein the convex portion is provided to extend in a horizontal direction and a vertical direction when the surface on which the convex portion is provided is viewed from the front. It exists in the gas meter characterized by being.

  According to invention of Claim 5, the convex part is extended and provided in the horizontal direction and the vertical direction seeing the surface in which the convex part is provided from the front. Therefore, by providing the protrusions extending in the horizontal direction and the vertical direction, when viewed from the front of the cover, a gap with the housing is provided at both ends of the cover in the horizontal and vertical directions, and water enters. Even if there is a risk of coming, intrusion can be surely prevented.

  As described above, according to the first aspect of the present invention, the air passage formed by the casing and the cover has a labyrinth structure, so that an additional part such as a resin film or a special film is not used. Since intrusion of water or the like into the body can be prevented, a compact and inexpensive gas meter having a water-resistant structure can be obtained.

  According to the second aspect of the present invention, the labyrinth structure can be formed with a simple configuration in which the convex portion is formed on the one surface provided with the opening and the back surface of the cover. A gas meter having a water-resistant structure can be obtained.

  According to the third aspect of the present invention, since the water is caused to flow downward and drain toward the end along the inclination by inclining the surface arranged vertically upward, the labyrinth. Since water does not collect inside the air passage of the structure, a gas meter with high water resistance can be obtained.

  According to the fourth aspect of the present invention, the surface of the water disposed along the vertical direction is inclined so that the water droplets attached to the surface disposed along the vertical direction are separated from the surface by gravity. Therefore, since water droplets are separated from the surface arranged along the vertical direction and drained, water does not accumulate inside the ventilation path of the labyrinth structure, and thus a highly water-resistant gas meter can be obtained.

  According to the fifth aspect of the present invention, the convex portions are provided so as to extend in the horizontal direction and the vertical direction, so that when viewed from the front of the cover, the cover is attached to the ends of both the horizontal and vertical directions of the cover. Even if a gap is provided and water may intrude, the invasion can be surely prevented, so that a gas meter with higher water resistance can be obtained.

  The gas meter of the present invention will be described below with reference to the drawings. Fig.1 (a) is a rear view of the front cover which comprises the gas meter of this invention, FIG.1 (b) is a front view of the housing | casing which comprises the gas meter of this invention. 2 (a) is a front view of the gas meter shown in FIG. 1, FIG. 2 (b) is a side view of the gas meter shown in FIG. 1, and FIG. 2 (c) is a bottom view of the gas meter shown in FIG. FIG. 3 is a cross-sectional view of the gas meter shown in FIG. 2 taken along the line II-II.

  As shown in the figure, the gas meter of the present invention includes a housing 10 and a front cover 20 that covers the front surface Sf of the housing 10. The housing 10 includes a housing body 11 having a gas inlet / outlet port 11 a formed on the top surface and a bottom cover 12. Inside the housing 10, a flow rate measuring unit comprising a gas flow path (not shown) communicating with the above-described outflow / inlet port 11 a and a flow rate sensor (not shown) for measuring the flow rate of gas flowing through the gas flow path. Or the pressure sensor (not shown) which measures the pressure in the gas flow path mentioned above is accommodated.

  In addition, an opening 11b is formed in the front surface Sf of the housing body 11, and an electronic board (not shown) that accommodates electrical components such as a liquid crystal display that displays an integrated flow rate and a terminal block from the opening 11b. ) Is exposed. The front cover 20 is provided with the above-described opening 21 for the liquid crystal display and the opening 22 for the terminal block. The liquid crystal display accommodated in the housing 10 can be seen through the opening 21 for the liquid crystal display.

  Further, the terminal block provided on the electronic board is exposed to the outside through the terminal block opening 22. However, as shown in FIG. 2A, the terminal block opening 22 is covered with the terminal block cover 30 so that the terminal block is exposed from the opening 22 only when the terminal block cover 30 is removed. It has become. Reference numeral 23 denotes a screw hole for attaching the terminal block cover 30.

  On the back surface of the front cover 20, a convex peripheral edge portion 24 is formed in contact with a portion surrounding the opening 11 b in the front surface Sf. A vent hole 24a is formed in a part of the peripheral edge portion 24, and the air enters the inside of the opening 11b of the housing body 11 only through the vent hole 24a.

  Further, on the back surface of the front cover 20, the lower side of the vent hole 24a described above is concave, and a space is formed between the concave portion 25 and the front surface Sf of the housing 10 facing the concave portion 25. Yes. A convex peripheral edge 26 that is one step lower than the peripheral edge 24 described above is formed on the periphery of the front cover 20 below the vent hole 24a. By forming it one step lower in this way, a gap 26 a communicating with the space is formed between the lower side of the housing 10 and the front cover 20 as shown in FIG. Further, as shown in FIG. 2C, a gap 26 b communicating with the space is also formed between the bottom cover 12 and the front cover 20.

  With the above configuration, the air is introduced into the space formed by the concave portion 25 of the front cover 20 and the front surface Sf of the housing body 11 facing the concave portion 25 through the gaps 26a and 26b described above, and further the ventilation holes It will penetrate | invade in the housing | casing 10 through 24a. That is, the concave portion 25 of the front cover 20 and the front surface Sf of the housing body 11 facing the front portion 20 form a ventilation path that ventilates the outside and the inside of the housing 10. Further, the concave portion 11d formed by the convex portion 11c provided on the front surface Sf that forms the air passage and the convex portion 27 provided on the concave portion 25 on the back surface of the front cover 20 that similarly forms the air passage are fitted. Thus, as shown in FIG. 2A and FIG. 3, the labyrinth structure R is formed in the ventilation path.

  As described above, the air passage formed by the housing 10 and the front cover 20 has the labyrinth structure R, so that water can be introduced into the housing 10 without using additional parts such as a resin film or a special film. Can be prevented, and a compact and inexpensive water-resistant structure can be provided. Moreover, the labyrinth structure can be formed with a simple configuration in which the front surface Sf provided with the opening 11b and the convex portions 11c and 27 are formed on the back surface of the front cover 20.

  The labyrinth-structured air passage is provided on the front surface of the housing 10. For example, it is also conceivable to provide an opening on the top or bottom surface of the housing 10 and provide a labyrinth-structured air passage with the top or bottom surface of the housing 10 and a cover that covers the top or bottom surface. However, in this case, there is a possibility that water cannot be drained while water is accumulated in the concave portion formed between the plurality of convex portions. However, by providing a labyrinth-structured air passage on the side surface of the housing 10 as in this embodiment, water can be drained without accumulating in the recess.

  Moreover, as shown in the enlarged view of the convex portion 27 shown in FIG. 4A, the convex portion 27 is formed in a letter shape substantially in a front view. As a result, the surface S1 of the convex portion 27 arranged vertically upward is inclined so as to approach the vertical lower side Y1 toward the end T1 of the surface S1. By attaching such an inclination, the invading water flows down and drains vertically along the inclination toward the end portion T1 as shown by the arrow Y2, and is thus drained inside the air passage of the labyrinth structure R. There is no accumulation of water.

  Further, as shown in the enlarged sectional view of FIG. 4B, the convex portions 11c and 27 have a trapezoidal cross section. As a result, the surfaces S2 and S3 arranged vertically upward of the convex portions 11c and 27 are inclined so as to approach the vertical lower side Y1 toward the ends T2 and T3 of the surfaces S2 and S3. It becomes. By inclining in this way, similarly, the invading water flows down vertically toward the end portions T2 and T3 along this inclination, and is drained, so that water enters the inside of the ventilation path of the labyrinth structure. There is no accumulation.

  Further, as shown in the enlarged sectional view of FIG. 4B, the surface S4 arranged along the vertical direction of the concave portion formed by the convex portions 11c, 27 or the convex portions 11c, 27 is arranged on the vertical lower side Y1. Inclined away from the front cover 20 and the housing 10 facing each other. By giving such an inclination, as shown in FIG. 5, gravity G is applied in the direction Y2 separating the water droplets W attached to the surfaces S4 and S5 arranged along the vertical direction from the surface. Since water droplets are separated from S4 and S5 and drained, water does not collect inside the air passage of the labyrinth structure.

  In the above-described embodiment, the convex portions 11c and 27 whose horizontal direction is horizontal are provided. For example, as shown in FIG. 6, the convex portions 11c and 27 whose horizontal direction is horizontal and the longitudinal direction are vertical. It is also conceivable to provide the convex portions 11c and 27 in combination. If it does in this way, it will come to the vent hole 24a also through the labyrinth structure similar to the water which penetrate | invaded from the clearance gap 26b also with respect to the water which penetrate | invaded from the clearance gap 26a of the side.

(A) is a front view of the housing | casing 10 which comprises the gas meter of this invention, (b) is a rear view of the front cover 20 which comprises the gas meter of this invention. (A) is a front view of the gas meter shown in FIG. 1, (b) is a side view of the gas meter shown in FIG. 1, and (c) is a bottom view of the gas meter shown in FIG. It is the II-II sectional view taken on the line of the gas meter of FIG. (A) is an enlarged view of the convex part 27 which comprises the gas meter of FIG. 1, (b) is an expanded sectional view of the convex parts 11c and 27 which comprise the gas meter of FIG. It is a figure for demonstrating the gravity G applied when the water droplet W sticks to the surfaces S4 and S5 shown in FIG. (A) is a front view of the housing | casing 10 which comprises the gas meter in other embodiment, (b) is a rear view of the front cover 20 which comprises the gas meter in other embodiment, (c) is It is a front view which comprises the gas meter in other embodiment.

Explanation of symbols

Sf front (one side)
11b Opening 10 Housing 11c Convex 11d Concave 20 Front cover (cover)
27 Convex

Claims (5)

A gas meter that houses a flow rate measurement unit and has a housing in which an opening is formed on a part of one surface, and a cover that covers the one surface,
A gas meter characterized in that an air passage having a labyrinth structure that ventilates the outside and the inside of the housing is formed by the one surface provided with the opening of the housing and the back surface of the cover facing the one surface. The gas meter according to claim 1, wherein
A concave portion formed by a convex portion provided on one side of the one surface provided with the opening forming the ventilation path, a back surface of the cover facing the one surface, and a convex portion provided on the other side are fitted. A gas meter characterized by a labyrinth structure. The gas meter according to claim 2, wherein
The gas meter is characterized in that the surface of the convex portion arranged vertically upward is inclined so as to approach the vertically lower side toward the end of the surface. The gas meter according to claim 2, wherein
The gas meter is characterized in that the surface arranged along the vertical direction of the convex portion or the concave portion is inclined to move away from the casing or cover facing the convex portion or the concave portion as it goes vertically downward. . The gas meter according to claim 2, wherein
The said convex part is extended and provided in the horizontal direction and the vertical direction seeing the surface in which the said convex part is provided from the front, The gas meter characterized by the above-mentioned.

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