JP4741207B2 - Gas meter - Google Patents

Description

  The present invention relates to a gas meter. Specifically, the present invention relates to an ultrasonic gas meter including a rectifying plate that adjusts the flow of gas.

As a conventional example of the above-mentioned gas meter, there is one in which a rectifying plate is assembled in a measurement channel through which a gas flows (see Patent Document 1). The current plate is a flat plate member, and is bridged and fixed to the inner wall surface of the measurement channel. A groove for fitting the rectifying plate is formed on the inner wall surface of the measurement channel.
The operation of assembling the current plate is generally performed using a predetermined jig. That is, in a state where the current plate is fixed to the jig, the groove portions are brought close to parallel to the current plate and are fitted to each other.
Japanese Patent Laid-Open No. 2003-202254

However, the above-described configuration has a problem that it takes a little time to assemble. In other words, when the groove portion is brought relatively close to the current plate, it cannot be fitted unless the relative positional relationship between them is appropriate. For this reason, if the groove portion is inclined with respect to the current plate or the relative position between the two is shifted, the fitting cannot be performed well and the assembly work has to be performed again.
However, if the opening dimension of the groove is set larger than the thickness of the current plate, the current plate can be inserted into the groove even if the current plate is slightly inclined. However, a gap is generated between the rectifying plate and the groove in the attached state. For this reason, another problem that the rectifying plate is rattled by the gas flowing through the measurement flow path at the time of gas flow measurement occurs.
The present invention has been devised in view of the above points. In other words, the problem to be solved by the present invention is to suppress the play of the rectifying plate as usual and to facilitate the fitting operation of the rectifying plate by storing the rectifying plate in a predetermined position while guiding it.

In order to solve the above problems, each invention of the present invention takes the following means.
A gas meter according to a first aspect of the present invention is a gas meter that measures the flow rate of a gas flowing in a measurement flow path using ultrasonic waves, and the measurement flow path has a quadrangular cross section perpendicular to the gas flow direction. The measurement channel is a cylindrical body, and includes a rectifying plate that is bridged and arranged between two opposing inner wall surfaces of the four inner wall surfaces, and the rectifying plate is a plate member that is long in the gas flow direction A groove portion into which the rectifying plate is inserted from a direction perpendicular to the inner wall surface is formed on the two inner wall surfaces facing each other, and the rectifying plate is stored and fixed at the tip in the depth direction of the groove portion. The opening formed on the inner wall surface side of the groove has an opening dimension larger than the plate thickness dimension of the rectifying plate when viewed in a cross section perpendicular to the gas flow direction, and the storage height of the storage section The thickness dimension has the same size as the plate thickness dimension of the current plate when viewed in the same cross section, and the groove portion is Viewed in cross-section, the opening size toward the housing section from the opening is formed so as to gradually decrease.

In the first invention, the groove portion includes an opening portion and a storage portion. The storage part is formed at the tip in the depth direction of the groove part rather than the opening part. The opening size of the opening is larger than the thickness of the current plate. From this opening, the current plate is inserted into the groove. And the storage height dimension of a storage part has a magnitude | size equivalent to the plate | board thickness of a baffle plate. A current plate is stored in the storage portion. The housed rectifying plate is in contact with and supported by the inner wall surface of the housing part from the thickness direction of the rectifying plate.
Further, a portion of the groove portion (hereinafter referred to as a guide portion) extending from the opening portion to the storage portion is formed in a shape in which the opening size gradually decreases. That is, the guide portion is formed with an inclined surface extending from the opening portion to the storage portion. When the rectifying plate at the time of the insertion operation comes into contact with the guide portion, the rectifying plate is guided to the tip in the groove depth direction along this inclined surface. The rectifying plate guided to the front end in the same direction is stored in the storage portion located at the front end in the same direction as described above.

The gas meter according to the first invention, the groove portion, a plurality of holes which are further formed in the depth direction the tip of the groove than accommodating portion is formed, both ends of the long sides of the rectifying plate, A pair of first protrusions to be inserted into the holes are formed, and the long sides of the rectifying plate are formed at positions different from the holes into which the pair of first protrusions are inserted. A second protrusion to be inserted into the formed hole is formed.

In the first invention, a pair of first protrusions are formed at both ends of the long side of the current plate. The pair of first protrusions are respectively inserted into holes formed at corresponding positions of the groove. The rectifying plate is positioned by the pair of inserted first protrusions. At this time, the portion of the rectifying plate in which the first protrusion is formed has a greater degree of accommodation in the groove than the other portion by the portion inserted into the hole. When the degree of accommodation of the rectifying plate is increased, the area (hereinafter referred to as a supporting area) for contacting and supporting the rectifying plate in the accommodated state is increased accordingly. When this support area is increased, the support force for contacting and supporting the current plate is increased.
A second protrusion is formed on the same side of the current plate. The 2nd projection part is formed in the position of the current plate different from the 1st projection part. The portion of the rectifying plate on which the second protrusion is formed has a support area equivalent to the portion of the rectifying plate on which the first protrusion is formed.

Next, a gas meter according to a second invention is the gas meter according to the first invention, wherein the first protrusion and the second protrusion are formed by chamfering the ridge corner at the tip that faces the groove during insertion. ing.
In the second invention, each protrusion is chamfered.

According to the present invention described above, the following effects can be obtained.
First, according to the first invention, since the rectifying plate is guided to the storage portion by the guide portion, the rectifying plate and the storage portion at the time of the insertion operation are inclined (or misaligned) within the range of the opening size of the opening portion. The operation of inserting the current plate can be continued. For this reason, the freedom degree of the positional relationship of the baffle plate and storage part at the time of insertion spreads. As the degree of freedom of the positional relationship between the two increases, the operation of fitting the current plate becomes easier.
Further, since the storage portion contacts and supports the rectifying plate in the stored state, it is possible to prevent or reduce the backlash of the rectifying plate as usual.

According to a first aspect of the present invention have equivalent support area and part of the rectifying plate portion and a second projecting portion of the current plate first protrusion of the positioning object is formed is formed. That is, both parts have the same supporting force. As a result, it is possible to prevent or reduce the rattling of the middle portion of the current plate, which has a weaker supporting force than both ends of the current plate, due to gas. That is, the rectifying plate can be fixed in a state where the groove portion is more stable.
Next, according to 2nd invention, since each projection site | part of the baffle plate is chamfered, a baffle plate can be smoothly moved to a storage part.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an external view of a gas meter, FIG. 2 is an internal structure diagram of the gas meter, and FIGS. 3 to 9 are diagrams of components of the gas meter.
The gas meter 1 according to the present embodiment is a device for measuring a gas flow rate using ultrasonic waves. The gas meter 1 measures the flow rate of a gas flowing in a measurement tube 30 (see FIG. 3) described later disposed therein. A rectifying plate 70 which will be described later is bridged and fixed to the opposing inner wall surface of the measuring tube 30.
The gas meter 1 according to the present embodiment has a configuration that facilitates the assembly work of the current plate 70.

[Gas meter appearance]
The gas meter 1 of FIG. 1 is a substantially rectangular box. As shown in the figure, a gas supply source inlet 3 and a gas facility outlet 5 are provided above the gas meter 1.
A gas supplied from a gas company or the like as a gas supply destination flows into the gas meter 1 from the gas supply source inlet 3. The gas whose gas flow rate is measured in the gas meter 1 flows out from the gas facility outlet 5 and is supplied to facilities and facilities that use the gas.

Display means 7 for displaying the integrated value of the gas flow rate and the like is provided on the front of the gas meter 1. The display content of the display means 7 can be changed as appropriate with a switching switch (not shown).
A communication terminal (not shown) is disposed inside the portion covered with the terminal cover 9. By connecting a communication device (not shown) to the communication terminal, the gas meter 1 can be operated by a signal sent from the communication device.

[Inside gas meter]
A first gas flow path 10, a gas flow rate measurement flow path 20, and a second gas flow path 15 are formed inside the gas meter 1 of FIG. 2. Each flow path communicates within the gas meter 1, and a passage through which gas passes is formed in a substantially U shape as viewed in the figure.
The gas that has flowed into the gas meter 1 from the gas supply source inlet 3 passes through the first gas flow path 10 and flows into the gas flow rate measurement flow path 20. The flow rate of the gas flowing into the gas flow rate measurement channel 20 is measured using ultrasonic waves. The gas whose flow rate is measured flows out of the gas facility outlet 5 through the second gas flow path 15 to the outside.

  The pressure of the gas flowing into the gas meter 1 is measured by a pressure sensor 15 a provided in the second gas flow path 15. The first gas passage 10 is provided with a shutoff valve 10a. When an abnormality is detected by the pressure sensor 15a, the cutoff valve 10a moves in the left direction as viewed in FIG. As an abnormality detected, for example, the gas pressure may exceed a preset pressure range.

[Gas flow measurement channel]
The gas flow measurement channel 20 of FIG. 3 includes a main body case 21 and a measurement tube 30.
The main body case 21 includes an upper lid member 21a and a bottom lid member 21b.
The upper lid member 21 a is a box that forms the outer shape of the main body case 21. In the upper part of the upper lid member 21a, communication ports 22 and 23 for communicating the inside of the main body case 21 and each gas flow path are formed. Two sensor storage portions 25 for assembling two ultrasonic transmission / reception sensors (not shown) are formed on both side surfaces of the upper lid member 21a. The two sensor storage portions 25, 25 are opposed to each other with a predetermined angle θ with respect to the gas flow direction (the direction indicated by the arrow in the figure).
By fitting a flat bottom cover member 21b into the upper cover member 21a, a body case 21 having a hollow interior is formed. A measuring tube 30 is accommodated in the main body case 21.

[Measurement tube]
The measuring tube 30 in FIG. 3 is a tube member having a substantially rectangular cross section including four sides of a first side wall portion 30l, a second side wall portion 30r, an upper surface portion 30u, and a bottom surface portion 30d.
As shown in FIG. 4, the measurement tube 30 includes a first measurement tube member 40, a second measurement tube member 50, a turbulent flow suppression member 60, and a rectifying plate 70.
The outer portion of the measurement tube 30 is composed of a first measurement tube member 40 and a second measurement tube member 50. A turbulent flow suppressing member 60 and a rectifying plate 70 are disposed at a predetermined position inside the measuring tube 30.

[First measuring tube member, second measuring tube member]
The first measurement tube member 40 and the second measurement tube member 50 in FIG. 4 are long plate members having a substantially L-shaped cross section. The measuring tube members 40 and 50 are assembled to each other by inserting a plurality of protruding members 90 formed on one side into an insertion hole 80 formed on the other side.
The first measuring tube member 40 constitutes two sides of the first side wall portion 30l and the bottom surface portion 30d described above (see FIG. 3). The second measuring tube member 50 constitutes two sides of the second side wall portion 30r and the upper surface portion 30u (see FIG. 3).
A sensor hole 41 is formed in the first side wall 30l, and a sensor hole 51 is formed in the second side wall 30r.
A plurality of groove portions 82 are respectively formed on the inner wall surface of the first side wall portion 30l and the inner wall surface of the second side wall portion 30r.

  From the sensor holes 41 and 51, the above-described ultrasonic transceiver faces the inside of the measuring tube 30. A concave mounting portion 45 is formed around each of the sensor holes 41 and 51. The mounting portion 45 is covered with a turbulent flow suppressing member 60 fitted therein. A mounting hole 62 is formed in the turbulent flow suppressing member 60. The turbulent flow suppressing member 60 is positioned and fixed to the mounting portion 45 by inserting the above-described protruding member 90 into the mounting hole 62.

[Groove]
The groove part 82 shown in FIG. 7 is a groove | channel which runs in parallel with respect to the bottom face part 30d. Three groove portions 82 are formed in the first side wall portion 30l. The groove 82 is formed across the sensor hole 41. Similarly, three groove portions 82 are formed in the second side wall portion 30r (see FIG. 4).
First hole portions 87 and 87 are formed at both end portions of the groove portion 82. The first hole portion 87 is a through-hole formed so as to penetrate the first side wall portion 30l in the thickness direction as well shown in FIG. A first protrusion 72 of a rectifying plate 70 described later is inserted into the first hole 87. A second hole 89 that is a through hole is also formed in the central portion of the long side of the groove 82. A second protrusion 73 of a rectifying plate 70 described later is inserted into the second hole 89.

Next, as shown in FIG. 8, an opening 83 is formed on each side wall portion 30 l (30 r) side of the groove portion 82. The opening 83 is formed such that its vertical dimension tk (opening dimension tk) is larger than the plate thickness of the rectifying plate 70 as viewed in FIG. The plate | board thickness of the baffle plate 70 shown in a present Example is 0.3 mm. The opening dimension tk is 0.5 mm.
A storage portion 86 for storing the rectifying plate 70 is formed at the left rear of the groove portion 82 in the figure. The storage portion 86 is a substantially rectangular hollow portion as viewed in FIG. The vertical dimension ts (storage height dimension ts) of the storage portion 86 as viewed in the figure is set to be approximately equal to the plate thickness dimension of the rectifying plate 70.
A guide portion 84 whose opening size gradually narrows is formed at a portion from the opening 83 to the storage portion 86 of the groove portion 82. That is, the guide portion 84 has a tapered shape in which the upper and lower inclined surfaces 84 a and 84 b approach each other from the opening 83 to the storage portion 86 as viewed in the figure.

[rectifier]
The rectifying plate 70 in FIG. 5 is a substantially flat plate member. The shape of the rectifying plate 70 is rectangular when viewed from above. And the length of the side (long side) positioned up and down as viewed in the same figure of the current plate 70 is set to be substantially the same as the length of the groove 82 described above (see FIG. 4). The long side of the current plate 70 is chamfered at the ridge angle.
Further, at the four corners of the rectifying plate 70, first protrusions 72 protruding upward (or downward) as viewed in the figure are formed. Further, a second protrusion 73 that protrudes upward (or downward) is formed at a substantially central portion of the long side of the current plate 70.

Both the first protrusion 72 and the second protrusion 73 are substantially rectangular protrusions when viewed from the front of FIG. Each of the protrusions 72 and 73 is formed in a shape and size that can be accommodated in the first hole 87 and the second hole 89 formed in the groove 82 described above.
In addition, as shown in FIGS. 5 and 6, the protrusions 72 and 73 have chamfered ridge angles that face the groove 82 when the rectifying plate 70 is inserted.

[Assembly method of current plate]
A method for assembling the current plate 70 will be described with reference to FIGS. 4, 8, and 9. FIG. 8 is a schematic diagram of a section taken along line VIII-VIII in FIG. FIG. 9 is a schematic diagram of a cross section taken along line IX-IX in FIG.
First, the current plate 70 is fixed at a position shown in FIG. 4 using a jig (not shown). Then, the second side wall 30r is brought closer to the first side wall 30l from the direction of the arrow in FIG.
At this time, the relative positional relationship between the current plate 70 and the groove 82 may be shifted. That is, the rectifying plate 70 may be displaced in the vertical direction as seen in FIG. At this time, the rectifying plate 70 first comes into contact with the guide portion 84 formed in the groove portion 82. The rectifying plate 70 in contact with the guide portion 84 is guided toward the storage portion 86 along the tapered inclined surface 84a (or 84b) provided in the guide portion 84. As a result, as shown in FIG. 8, the other side of the current plate 70 is stored in the storage portion 86. As a result, the current plate 70 is bridged and fixed between the first side wall part 30l and the second side wall part 30r.
At this time, as shown in FIG. 9, the first protrusion 72 is inserted into the first hole 87. The second protrusion 73 is inserted into the second hole 89.

[Action / Effect]
First, since the rectifying plate 70 is guided to the storage portion 86 by the guide portion 84, the rectifying plate 70 and the storage portion 86 during the insertion operation are displaced (or inclined) within the range of the opening dimension tk of the opening 83. The insertion operation of the current plate 70 can be continued. For this reason, the freedom degree of the positional relationship of the baffle plate 70 and the accommodating part 86 at the time of insertion expands. As the degree of freedom increases, the operation of fitting the current plate 70 becomes easier.
Further, since the storage portion 86 contacts and supports the rectifying plate 70 in the stored state, the backlash of the rectifying plate 70 can be prevented or reduced as usual.

Next, the portion of the current plate where the first protrusion 72 for positioning is formed and the portion of the current plate 70 where the second protrusion 73 is formed have an equivalent support area. That is, both parts have the same supporting force. As a result, it is possible to prevent or reduce the rattling of the middle portion of the rectifying plate having a weaker supporting force than both ends of the rectifying plate 70 due to gas.
Next, since each protrusion part 72 and 73 of the baffle plate 70 is chamfered, the baffle plate 70 can be moved to the accommodating part 86 smoothly.

[Other embodiments]
The gas meter 1 according to the present invention is not limited to the above-described embodiment, and can take other various embodiments.
First, a plurality of second protrusions 73 may be formed on the current plate 70. For example, if two pieces are formed at equal intervals on the long side of the current plate 70, the backlash of the current plate 70 can be further suppressed. Further, the first protrusion 72 and the second protrusion 73 need not have the same shape. For example, the second protrusion 73 may be formed longer in the gas flow direction than the first protrusion 72.
Moreover, the formation position of the 2nd projection part 73 can also be changed suitably.
Next may be one or two of the rectifying plate 70 are arranged in the measurement tube 30, three pieces or more of the rectifying plate 70 may be arranged in the measurement tube 30. The groove part 82 is formed according to the number of the baffle plates 70 arrange | positioned at this time. Further, the groove portions 82 may be formed more than the number of rectifying plates 70 arranged. In this case, the number and arrangement positions of the rectifying plates 70 can be appropriately changed depending on the flow rate of the flowing gas.

Next, the opening dimension tk of the opening 83 formed in the groove part 82 may be larger than the thickness dimension of the rectifying plate 70. For example, when the rectifying plate 70 is likely to be displaced upward in FIG. 8, the opening dimension tk is increased in the upward direction in FIG. Similarly, when the rectifying plate 70 is easily displaced downward, the opening dimension tk is increased downward.
The inclined surfaces 84a and 84b of the guide portion 84 may have any shape as long as the rectifying plate 70 can be guided to the storage portion 86. For example, the shape may be such that the central portions of the inclined surfaces 84a and 84b in FIG. Or it may have a shape inclined face 84a, a central portion of 84b of FIG is curved away from each other. The inclined surfaces 84a and 84b do not have to have a corresponding shape. That is, one may have a linear inclination as shown in FIG. 8, and the other may have a curved shape as described above.
Further, the first hole 87 and the second hole 89 do not have to penetrate the first side wall part 30l (or the second side wall part 30r). Moreover, you may form through only each hole 87,89 formed in either one side wall part 30l (30r).

Next, the current plate 70 and the protrusions 72 and 73 may not be chamfered. Further, only the projections 72 and 73 may be chamfered. In addition, chamfering may be performed only at one of the ridge angles of the protrusions 72 and 73 shown in FIGS.
Further, the ridge angles of the projections 72 and 73 may be rounded. For example, the first protrusion 72 located at the left end of the current plate 70 as viewed in FIG. 6 may be semicircular. Further, the first protrusion 72 may be triangular when viewed in the same figure. The shape of the second protrusion 73 can also be appropriately changed to the same shape as the first protrusion 72.

It is an external view of a gas meter. It is an internal structure figure of a gas meter. It is an exploded view of a gas flow measurement channel. It is an exploded view of a measuring tube. It is a front view of a baffle plate. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is a front view of a measurement pipe member. It is a schematic diagram of the VIII-VIII line cross section of FIG. It is a schematic diagram of the IX-IX line cross section of FIG.

DESCRIPTION OF SYMBOLS 1 Gas meter 3 Gas supply source inlet 5 Gas equipment outlet 7 Display means 9 Terminal cover 10 First gas flow path 10a Shut-off valve 15 Second gas flow path 15a Pressure sensor 20 Gas flow measurement flow path 21 Main body case 21a Top cover Member 21b Bottom cover member 22, 23 Communication port 25 Sensor housing part 30 Measurement tube 30l First side wall part 30r Second side wall part 30u Top face part 30d Bottom face part 40 First measurement pipe member 41, 51 Sensor hole 45 Attachment part 50 Second measurement tube member 60 Turbulence suppression member 62 Mounting hole 70 Current plate 72 First projection 73 Second projection 80 Insertion hole 82 Groove 83 Opening 84 Guide portions 84a, 84b Inclined surface 86 Storage 87 First hole 89 Second hole 90 Projection member

Claims (2)

A gas meter that measures the flow rate of gas flowing through a measurement channel using ultrasonic waves,
The measurement channel is a cylinder having a quadrangular cross section perpendicular to the gas flow direction,
The measurement flow path includes a rectifying plate arranged to be bridged between two inner wall surfaces facing each other among the four inner wall surfaces,
The rectifying plate is a plate member elongated in the direction in which the gas flows,
The two opposing inner wall surfaces are formed with grooves into which the current plate is inserted from a direction perpendicular to the inner wall surfaces,
A storage portion for storing and fixing the rectifying plate is formed at the depth direction tip of the groove portion,
The opening portion opened to the inner wall surface side of the groove portion has an opening dimension larger than a plate thickness dimension of the rectifying plate as seen in a cross section perpendicular to the gas flow direction,
The storage height dimension of the storage portion has a size equivalent to the plate thickness dimension of the rectifying plate, as viewed in the same cross section,
The groove part is formed so that the opening size thereof gradually decreases from the opening part toward the storage part when viewed in the same cross section ,
The groove portion is formed with a plurality of holes formed at the distal end in the depth direction of the groove portion further than the storage portion,
At both ends of the long side of the rectifying plate, a pair of first protrusions that are inserted into the holes to position the rectifying plate are formed, and
A long side of the current plate is formed with a second protrusion that is inserted into a hole formed at a position different from the hole into which the pair of first protrusions are inserted. A gas meter characterized by that. The gas meter according to claim 1,
The gas meter according to claim 1, wherein the first projecting portion and the second projecting portion are formed by chamfering a ridge corner portion at a tip that faces the groove portion at the time of insertion .

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