JP2010019593A - Diaphragm type gas meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm type gas meter wherein a front case is made of a resin, preventing intrusion of water from the case including an opening part provided on the case. <P>SOLUTION: This diaphragm type gas meter 1 is loaded with an electronic control unit. The electronic control unit at least a part of which is provided on the lower side of a counter for displaying an integrated flow rate value, is disposed on the back side of the front case, and on the front side of a rear lower side case 40 and/or a rear upper side case 30. The front case is made of resin, and is constituted by including a front lower side case 20 and a front upper side case 10. The front lower side case 20 has the first fitting part having a projecting shape or a recessed shape extending along the uppermost part, on the front side of the uppermost part. The front upper side case 10 has an opening part capable of viewing a counter, and has the second fitting part having a recessed shape or a projecting shape extending along the lowermost part, on the back side of the lowermost part. The first fitting part and the second fitting part are fitted mutually in the state where the lowermost part is covered on the uppermost part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a membrane gas meter having a waterproof structure.

  Most membrane gas meters installed outdoors are equipped with an electronic control unit, and a waterproof structure is provided to protect the electronic control unit. If only the electronic control unit is protected and water intrusion is prevented, the electronic control unit case in which the electronic control unit is housed can be realized by attaching an elastic member such as rubber.

  In addition, a membrane gas meter installed outdoors is provided with a counter including a number wheel to display the measured flow rate integrated value, and this counter can be seen from an opening provided in the front case. It is installed. Since this counter requires airtightness, the casing is made of rigid aluminum die casting so that the airtightness is maintained only by the counter. Also, since at least a part of the electronic control unit is mounted below the counter, the front case is made of rigid aluminum die casting to prevent deformation of the opening and displacement of the position of the opening. Prevents intrusion of water from the section.

As a rainproof structure for an electronic device installed outdoors, Patent Document 1 describes a rainproof structure for connection terminals provided on an interphone installed outdoors. The technique described in Patent Document 1 is to install a terminal rainproof cover so that water drops on the transmission line are dropped in a direction away from the connection terminal. Further, the terminal rainproof lid is fixed to the lower case with a claw and can be easily removed from the lower case.
JP 2005-159892 A

  However, if the front case is made of rigid aluminum die casting like the conventional membrane meter, it becomes expensive. Therefore, it is preferable that the front case is made of an inexpensive resin. However, when a resin front case is adopted, the resin is not rigid and deforms, creating a gap in the opening, and is positioned below the opening. Water enters the electronic control unit. Thus, the resin-made front case has difficulty in airtightness and waterproofness. Although it is possible to prevent water from entering by making the electronic control unit itself airtight, such a structure is difficult to maintain.

  The present invention has been made in view of the actual situation as described above, and is a waterproof structure capable of preventing water from entering from a case including a front case made of resin and including an opening provided in the case. It is an object of the present invention to provide a membrane gas meter having

  In order to solve the above problems, a first technical means of the present invention includes a rear lower case constituting a measuring chamber for measuring a gas flow rate by reciprocating movement of a membrane, a pressure sensor, and a shut-off valve. A rear upper case disposed above the rear lower case, a counter disposed on a front surface of the rear upper case and displaying an integrated value of the gas flow rate measured in the measurement chamber, and at least a part thereof Is provided below the counter, and has an electronic control unit having a substrate, a front surface of the lower rear case, a front surface of the upper rear case, the counter, and a front surface disposed so as to cover the electronic control unit The front case is made of resin and includes a front lower case disposed on the lower side and a front upper case disposed on the upper side. Upper side And the front lower case has a convex or concave first fitting portion extending along the uppermost portion on the front surface side of the uppermost portion. The front upper case has a concave or convex second fitting portion extending along the lowermost portion on the back side of the lowermost portion, and the first fitting portion and the second fitting portion The parts are characterized in that the uppermost part of the lower front case is fitted with the lowermost part of the upper upper case.

  According to a second technical means, in the first technical means, a claw hooking portion is provided in any one of the rear upper case, the rear lower case, and the front lower case, and the front upper case includes the second upper case, A claw part for hooking and holding the claw hook part is provided in the vicinity of the fitting part.

  According to a third technical means, in the first or second technical means, a hole is provided in any one of the rear upper case, the rear lower case, and the front lower case. 2 In the vicinity of the left and right ends of the fitting portion, convex portions that fit into the hole portions are provided.

  According to the present invention, in the membrane gas meter, the front case is made of resin, and water can be prevented from entering from the case including the opening provided in the case.

  The membrane gas meter of the present invention and its waterproof structure will be described with reference to FIGS. FIG. 1 is an external view showing an example of a membrane gas meter of the present invention installed outdoors. 2 is an external view showing a state in which the counter case is removed in the membrane gas meter of FIG. 1 and the inside of the counter display unit is exposed, and FIG. 3 is an external view showing a structure on the back side of the counter case of FIG. 4 is an external view showing the structure of the front side of the electronic control unit case in the membrane gas meter of FIG. 5 and 6 are cross-sectional views showing a state where the back side of the counter case of FIG. 3 is locked to the front side of the electronic control unit case of FIG.

  As shown in FIG. 1, the membrane gas meter 1 of the present invention includes a measuring unit including a rear upper case 30 and a rear lower case 40, a counter display unit 10, and an electronic control unit 20. The rear lower case 40 is mainly provided with a measuring chamber for measuring the gas flow rate by reciprocating movement of the membrane, and the rear upper case 30 is mainly provided with a pressure sensor and a shut-off valve. The rear lower case 40 may be appropriately provided with parts other than the case main body and the measurement chamber as required. Similarly, in addition to the case main body, the pressure sensor, and the shut-off valve, the rear upper case 30 may be appropriately provided with parts as necessary. In addition, in this specification, it describes as the front, back, upper side, lower side, horizontal direction etc. on the basis of the time when the membrane gas meter 1 is installed at the normal position.

  The electronic control unit 20 includes a resin front lower case (electronic control unit case) 21 that can be manufactured at a lower cost than aluminum die casting and the like, and an electronic control unit (not shown) on which a substrate is mounted. . On the board, electronic components such as a microcomputer that performs processing calculation such as a flow rate value, and a liquid crystal display unit that displays various integrated values and warning information are mounted. Here, an electronic control unit is provided on the front surface of the rear lower case 40, and an electronic control unit case 21 is further provided so as to cover them.

  The arrangement of the electronic control unit in the front-rear direction is not limited to the illustrated example, and the rear lower case 40 on the rear side of the front case including the electronic control unit case 21 and the counter case 11 described later, It suffices to be disposed on the front side of the rear upper case 30. Moreover, as an arrangement | positioning of the electronic control unit of the up-down direction, it should just be arrange | positioned so that the part may be located below the below-mentioned counter housing | casing 12.

  In addition, a terminal block is connected to the electronic control unit described above, and this terminal block is covered with a terminal block cover 21a so as to be flat with the electronic control unit case 21, and the electronic control unit or the rear lower part is covered with screws 50b. It is attached to the side case 40. The waterproof processing of the joint between the terminal block cover 21a and the electronic control unit case 21 may be performed by an elastic member such as rubber.

  As shown in FIG. 2, the counter display unit 10 includes a counter housing 12, a glass 13, and a front upper case (counter case) 11. The counter housing 12 is made of rigid aluminum die casting and surrounds a counter cylinder provided inside. The counter cylinder is a number wheel that counts and displays the integrated value of the gas flow rate. Since the counter housing 12 is required to be airtight and to be able to visually recognize the integrated flow rate value indicated by the counter cylinder, an opening is provided in the front, and the opening is closed by adhering glass 13 to the opening. It is peeling off. The counter display unit 10 is provided with a counter case 11 having a portion formed by adhering the glass 13 to the counter casing 12 in the front surface of the rear upper case 30 and further having an opening 14 so as to cover them. And is attached to the rear upper case 30 with screws 50a.

  The counter case 11 is made of a resin that can be manufactured at a lower cost than aluminum die casting or the like, and the opening 14 is disposed at the position where the glass 13 is disposed so that the integrated flow rate can be visually recognized through the glass 13. It is provided to suit. When the counter case 11 is attached, as shown in FIG. 3, the female wall 17 a presses the packing 15 shown in FIG. 2 and the glass 13 bonded to the counter housing 12 is attached to the counter case 11. It is pressed by a packing 16 attached around the opening 14 to prevent the entry of water such as rain from the outside.

  As described above, when the membrane gas meter 1 uses a resin having difficulty in rigidity as a material for the front case, in order to reduce the influence on the waterproof property, like the counter case 11 and the electronic control unit case 21, The amount of deformation for each case is reduced by dividing the case provided on the front surface into two or more.

  In order to further improve waterproofness, the membrane gas meter 1 employs a waterproof structure as described below at the joint between the counter case 11 and the electronic control unit case 21.

  The waterproof structure of this joint will be described. As exemplified by the recess 23 in FIG. 4, the electronic control unit case 21 has a concave first fitting portion that extends along the uppermost portion on the front side of the uppermost portion. On the other hand, the counter case 11 has a convex second fitting portion extending along the lowermost portion on the back side of the lowermost portion, as exemplified by the convex portion 18 of FIG. And when attaching the counter case 11 to the back upper case 30 side, the convex part 18 (FIG. 3) formed in the counter case 11 in the state which covered the lowest part of the counter case 11 on the uppermost part of the electronic control part case 21. Are engaged with each other so as to enter between the recesses 23 (FIG. 4) formed in the electronic control unit case 21. FIG. 5 shows a cross section of such a state where the convex portion 18 and the concave portion 23 are engaged with each other. Since the structure in which the convex portion 18 and the concave portion 23 are fitted becomes a double wall structure, the water intrusion path can be lengthened. As a result, the gap between the counter case 11 and the electronic control unit case 21 can be increased. Infiltration of water can be prevented.

  Moreover, waterproofness may be further improved by providing a packing or the like between the convex portion 18 and the concave portion 23. Further, the waterproof effect can be further increased by narrowing the gap between the convex portion 18 and the concave portion 23 and further increasing the irregularities. Further, a concave portion may be provided on the counter case 11 side, and a convex portion may be provided on the electronic control unit case 21 side.

  As described above, according to the membrane gas meter of the present invention, the front case is made of resin, and water enters from the opening provided in the case or the gap between the counter case 11 and the electronic control unit case 21. Can be prevented.

  Further, as shown in FIG. 3, a claw portion 17c is provided on the back side of the counter case 11 and in the vicinity of the convex portion 18, and the claw hook portion 22c provided in the electronic control unit case 21 shown in FIG. It is preferable to hold the counter case 11 by hooking 17c. FIG. 5 shows a cross section of the engaging state between the claw portion 17c and the claw hooking portion 22c. By adopting such a structure, it is possible to eliminate the vertical lift due to deformation or the like, and the possibility of water intrusion due to the generation of a gap between the concave portion 23 and the convex portion 18 due to deformation of the counter case 11 or the like. Can be reduced. Moreover, you may provide a nail | claw hook part in a back upper case or a back lower case.

  Further, as shown in FIG. 3, two convex portions 17b are provided on the back side below the counter case 11 and in the vicinity of the left and right ends of the convex portion 18, and two are provided in the electronic control unit case 21 shown in FIG. It is preferable to insert and fit into the hole 22b. Although the convex part 17b is illustrated by the circular convex part, not only this but a projection part should just be sufficient, and the hole part 22b should just be a shape suitable for this. A horizontal section showing such a fitting state of the convex portion 17b and the hole portion 22b is as shown in FIG. By adopting such a structure, it is possible to eliminate lateral opening due to deformation or the like, and there is a possibility that a gap is generated between the concave portion 23 and the convex portion 18 due to deformation or the like of the counter case 11 and water enters. Can be reduced.

  Such a structure exemplified by the convex part 17b and the hole part 22b can be adopted regardless of whether the structure provided with the claw part 17c and the claw hooking part 22c is adopted. Further, the hole may be provided in the rear upper case or the rear lower case. Alternatively, the hole may be provided at the same position in both the front lower case and the rear upper case or the rear lower case, and the convex portion may be attached so as to penetrate both.

It is an external view which shows an example of the film | membrane type gas meter of this invention installed outdoors. It is an external view which shows a mode that the counter case was removed and the inside of the counter display part was exposed in the film | membrane type gas meter of FIG. It is an external view which shows the structure of the back side of the counter case of FIG. It is an external view which shows the structure of the front side of the electronic control part case in the film | membrane type gas meter of FIG. It is sectional drawing which shows a mode that the back side of the counter case of FIG. 3 was latched to the front side of the electronic control part case of FIG. It is sectional drawing which shows a mode that the back side of the counter case of FIG. 3 was latched to the front side of the electronic control part case of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Membrane gas meter, 10 ... Counter display part, 11 ... Counter case, 12 ... Counter housing, 13 ... Glass, 14 ... Opening part, 15, 16 ... Packing, 17a ... Female wall, 17b ... Projection part, 17c ... Claw part, 18 ... convex part, 20 ... electronic control part, 21 ... electronic control part case, 21a ... terminal block cover, 22b ... hole part, 22c ... claw hooking part, 23 ... concave part, 30 ... rear upper case, 40 ... rear lower case, 50a, 50b ... screws.

Claims (3)

A rear lower case constituting a measuring chamber for measuring gas flow rate by reciprocating movement of the membrane;
A rear upper case provided with a pressure sensor and a shut-off valve inside and disposed above the rear lower case;
A counter disposed on the front face of the upper rear case and displaying an integrated value of the gas flow rate measured in the measuring chamber;
An electronic control unit at least partially provided on the underside of the counter and having a substrate;
A front case disposed to cover the front surface of the rear lower case, the front surface of the rear upper case, the counter, and the electronic control unit, and a membrane gas meter,
The front case is made of resin, and includes a front lower case disposed on the lower side and a front upper case disposed on the upper side,
The front upper case has an opening that makes the counter visible.
The lower front case has a convex or concave first fitting portion extending along the uppermost portion on the front side of the uppermost portion,
The front upper case has a concave or convex second fitting portion extending along the lowermost portion on the back side of the lowermost portion,
The membrane gas meter, wherein the first fitting portion and the second fitting portion are fitted to each other in a state where the uppermost portion of the front lower case is covered with the lowermost portion of the front upper case.   A claw hooking portion is provided on any one of the rear upper case, the rear lower case, and the front lower case, and the front upper case is hooked on the claw hooking portion in the vicinity of the second fitting portion. 2. A membrane gas meter according to claim 1, further comprising a claw portion for holding it.   A hole is provided in any of the rear upper case, the rear lower case, and the front lower case, and the front upper case is fitted to the hole in the vicinity of the left and right ends of the second fitting portion. The membrane gas meter according to claim 1, wherein a convex portion is provided.

Images