JP4555669B2 - Flow measuring device - Google Patents

Description

  The present invention relates to a gas flow path section that forms a gas flow path that connects a gas flow inlet and a gas flow outlet, and a measurement flow path that forms a measurement flow path that is housed in the gas flow path section and is provided with a flow velocity sensor. The present invention relates to a flow rate measuring device including a unit.

  In recent years, an electronic gas meter that uses a microcomputer to calculate a gas flow rate from a flow rate detected by a flow rate sensor has become widespread. As the electronic gas meter is further downsized, it is not possible to sufficiently secure the straight line portion of the flow path before and after the flow velocity sensor, and the flow velocity sensor is likely to be affected by the upstream gas supply pressure and the downstream gas usage status. The problem occurs.

  In addition, water heaters and gas heat pumps as gas consuming equipment are often driven intermittently, and therefore pressure fluctuations in the flow path, that is, pulsation may occur, and backflow may occur. In order to solve the above problem, an electronic gas meter in which a rectifying plate is attached to a flow path in a meter to which a flow rate sensor is attached has been proposed.

  FIG. 6 is a partial longitudinal sectional view showing a configuration example of a conventional electronic gas meter. As shown in the figure, the gas meter includes a gas flow channel portion 100 that forms a gas flow channel that connects a gas flow inlet and a gas flow outlet, and a multilayer unit 200 that is accommodated in the gas flow channel portion 100. It has. The multilayer unit 200 is provided with a plurality of rectifying plates 201 for partitioning the formed measurement flow path while forming a measurement flow path for measurement by the flow velocity sensor.

  In the electronic gas meter as described above, a gap is generated between the gas flow path unit 100 and the multilayer unit 200 in consideration of assembly. Due to this gap, the gas that should flow only in the multilayer unit 200 flows out of the multilayer unit 200 from this gap C. Since this outflow amount changes depending on the size of the gap C, if the size of the gap C varies among products, the characteristics as a gas meter may vary.

  7A is a cross-sectional view taken along line VI-VI of the electronic gas meter shown in FIG. 6, and FIG. 7B is a cross-sectional view taken along line VII-VII in FIG. As shown in the figure, the gaps Cl and Cr are generated not only in the vertical direction of the multilayer unit 200 as shown in FIG. 6 but also in the horizontal direction with respect to the flow direction Y1 of the multilayer unit 200. However, when the gas flow path unit 100 and the multi-layer unit 200 are formed so that the gaps Cl and Cr are generated between the gas flow path unit 100 and the multi-layer unit 200 in consideration of the assembly property as described above, FIG. As shown in (b), a deviation ΔP occurs with respect to the central position where the multilayer unit 200 should be originally disposed.

  Further, depending on the assembly, the deviation ΔP from the center position of the multilayer unit 200 varies from product to product, and this also causes variations in characteristics as a gas meter.

  Therefore, it is conceivable to increase the component accuracy of the gas flow path unit 100 and the multilayer unit 200 so that the gap C becomes the minimum gap and does not vary from product to product, but this limits the yield.

  It is also conceivable to correct the variation in the flow velocity measurement characteristics by rewriting internal information relating to the calculation for obtaining the gas flow rate from the flow velocity using a PC or the like. However, if the flow velocity measurement characteristics are different for each product, it is necessary to have a large number of correction parameters, leading to an increase in cost.

  Accordingly, the present invention pays attention to the above-described problems, and an object of the present invention is to provide a flow rate measuring device that can reduce the variation in flow rate measurement characteristics for each product at a low cost.

The invention of claim 1, wherein has been made to solve the above problems, a gas passage portion forming a gas passage for communicating the gas inlet and gas outlet are accommodated in the gas flow portion, gas Between a measurement flow path portion that forms a measurement flow path in which flow velocity measurement is performed by two ultrasonic sensors arranged apart from each other in the flow direction, and between the inner surface of the gas flow path section and the outer surface of the measurement flow path section And a clogging means for preventing gas that has passed through the gap from flowing to the gas outlet, wherein the clogging means includes two ultrasonic sensors. Of these, the flow path is provided on the upstream side of the ultrasonic sensor disposed on the upstream side in the gas flow direction and on the downstream side of the ultrasonic sensor disposed on the downstream side in the gas flow direction. It exists in a measuring device.

According to the first aspect of the present invention, the closing means closes the gap between the inner surface of the gas flow path section and the outer surface of the measurement flow path section, and prevents the gas passing through the gap from flowing to the gas outlet. . Accordingly, the gas does not flow out of the measurement flow path portion from the gap, and the flow velocity measurement characteristic does not vary depending on the size of the gap. Further, the blocking means is an upstream side of the ultrasonic sensor disposed upstream of the two ultrasonic sensors in the gas flow direction, and a downstream side of the ultrasonic sensor disposed on the downstream side of the gas flow direction, Are provided respectively. Therefore, the gas flowing in the gap does not affect the gas flow between the two ultrasonic sensors, and variation in flow velocity measurement characteristics due to the size of the gap can be further reduced.

According to a second aspect of the invention, a flow rate measuring device according to claim 1, wherein the measurement flow path, there is provided a flow rate measuring apparatus characterized by comprising a rectifying plate for dividing the measurement flow path .

According to the second aspect of the present invention, the gas flow does not flow out of the measurement flow path divided by the rectifying plate, and the flow velocity measurement characteristics do not vary depending on the size of the gap.

Wherein the invention according to claim 3, a flow path measuring device according to claim 1 or 2, wherein the busy means is an elastic band which is wound around the measurement flow path outer surface It exists in the flow-path measuring device.

According to the third aspect of the present invention, the closing means is constituted by an elastic band wound around the outer surface of the measurement flow path portion. Therefore, as compared with the case where the adhesive is filled in the gap, even if it is necessary to remove the measurement flow path portion from the gas flow path portion by recycling or the like, it can be easily removed.

Invention of Claim 4 is the flow-path measuring apparatus of Claim 1 or 2 , Comprising: The said block means is an elastic convex part formed in the said measurement flow-path part outer surface, It is characterized by the above-mentioned. It exists in the flow measurement device.

According to the fourth aspect of the present invention, the blocking means is an elastic convex portion formed on the outer surface of the measurement flow path portion. Therefore, compared with the case where the gap is filled with an adhesive, it is possible to easily remove the measurement flow path portion from the gas flow path portion by recycling or the like. In addition, if the measurement flow path portion is formed of an elastic member such as a resin, the convex portion that is the blocking means can be formed integrally with the measurement flow path portion.

Invention of Claim 5 is the flow-path measuring apparatus of Claim 3 , Comprising: The said measurement flow-path part is provided in the one surface which forms the said measurement flow-path, and said 2nd through the ultrasonic wave of the said ultrasonic sensor A pair of openings provided to exchange ultrasonic waves between the two ultrasonic sensors, and a pair of mesh holders that respectively close the openings, and the band is wound on the mesh holder It exists in the flow measuring device characterized by this.

According to invention of Claim 5 , the band is wound on the mesh holder. Therefore, it is possible to make it difficult for the mesh holder to be detached from the measurement flow path by using the band.

A sixth aspect of the present invention is the flow rate measuring device according to the first or second aspect , wherein the blocking means is a seal applied to a gap between the gas channel inner surface and the measurement channel portion outer surface. It exists in the flow measuring device characterized by being an agent.

According to invention of Claim 6 , the sealing agent is apply | coated to the clearance gap between a gas flow path inner surface and a measurement flow path part outer surface. Therefore, the gap can be easily closed using the sealant.

As described above, according to the first aspect of the present invention, the gas flow does not flow out of the measurement flow path portion, and the flow velocity measurement characteristics do not vary depending on the size of the gap. In addition, it is possible to obtain a flow rate measuring device in which variations in flow rate measurement characteristics for each product are reduced. In addition, a gas flow measuring device is obtained in which the gas flowing in the gap does not affect the gas flow between the two ultrasonic sensors, and variation in flow velocity measurement characteristics due to the size of the gap can be further reduced. Can do.

According to the second aspect of the present invention, the gas flow does not flow out of the measurement flow path divided by the rectifying plate, and the flow velocity measurement characteristics do not vary depending on the size of the gap. In addition, it is possible to obtain a flow rate measuring device in which variations in flow rate measurement characteristics for each product are reduced.

According to the invention of claim 3 , compared with the case where the gap is filled with an adhesive, even if it is necessary to remove the measurement flow path part from the gas flow path part by recycling or the like, it can be easily removed. It is possible to obtain a flow rate measuring device that reduces costs even when it is detached.

According to the invention described in claim 4, it is possible to easily remove the measurement flow path portion from the gas flow path portion by recycling or the like as compared with the case where the adhesive is filled in the gap. In addition, if the measurement channel part is made of an elastic member such as resin, the convex part, which is the clogging means, can be formed integrally with the disputed flow path part. Thus, a flow rate measuring device that achieves the above can be obtained.

According to the fifth aspect of the present invention, it is possible to obtain a flow rate measuring device that can divert the mesh holder from the measurement flow path part by using the band.

According to the sixth aspect of the present invention, it is possible to obtain a flow rate measuring device that can easily close the gap using the sealant.

First Embodiment Hereinafter, a flow rate measuring device of the present invention will be described with reference to the drawings. FIG. 1 is an exploded cross-sectional view of a gas meter incorporating the flow rate measuring apparatus of the present invention, and FIG. 2 is a perspective view of a multilayer unit constituting the gas meter of FIG.

  As shown in FIG. 1, the gas meter has a meter body 10 having a gas inlet 11 and a gas outlet 12 on the top surface and an opening 13 on the bottom surface, and a flow accommodated in the meter body 10. A path unit 20 (= gas flow path part) is provided. The channel unit 20 described above includes an inlet channel 21 that communicates with the gas inlet 11, an outlet channel 23 that communicates with the gas outlet 12, and an intermediate that communicates between the inlet channel 21 and the outlet channel 23. The gas flow path part 22 is comprised and the gas flow path which connects the gas inflow port 11 and the gas outflow port 12 is formed.

  The intermediate channel portion 22 described above is provided with openings 22a1 and 22a2 on the upper surface thereof, which communicate with the openings 21a and 23a provided on the bottom surfaces of the inlet channel portion 21 and the outlet channel portion 23, respectively. And the flange parts 21b and 23b provided in the periphery of opening part 21a and 23a, and the periphery of opening part 22a1 and 22a2 of the intermediate flow path part 22 are being fixed with the screw | thread D1. Thereby, fixation with the inlet flow path part 21 and the outlet flow path part 23, and the intermediate flow path part 22 can be performed, maintaining the gas tightness inside the flow path unit 20. FIG.

  Further, the intermediate flow path portion 22 is formed of an intermediate flow path body 22b provided on the bottom surface side and an upper lid 22c provided on the upper surface side while being formed separately from the intermediate flow path body 22b. Yes. In addition, a multilayer unit 24 (= measurement flow path portion) in which flow velocity measurement is performed by a flow velocity sensor is accommodated in the intermediate flow path portion 22. In the present embodiment, two ultrasonic sensors that are spaced apart from each other in the gas flow direction and arranged opposite to each other so as to form an angle with the flow direction are used as the flow velocity sensors.

  As shown in FIG. 2, the multilayer unit 24 includes a flow path forming portion 24a that forms a measurement flow path having a substantially square cross section, and a rectifying plate 24b that divides the measurement flow path formed by the flow path formation portion 24a. It is integrally formed of resin. In addition, the left and right side surfaces of the flow path forming portion 24a are each provided with two openings spaced apart in the gas flow direction, and the two openings are respectively closed by the mesh holder 24c. The mesh holder 24c holds the mesh 25 attached to the holder opening 24c1.

  The two ultrasonic sensors described above are respectively disposed on the back surfaces of the two mesh holders 24c, and ultrasonic waves are transmitted and received through the holder openings 24c1 of the mesh holders 24c. The mesh 25 is provided to prevent vortices generated in a space formed between the ultrasonic sensor and the holder opening 24c1. In addition, as a fixing method of the mesh holder 24c, for example, a method of providing a claw at the opening of the mesh holder 24c or the flow path forming portion 24a and fixing it can be considered.

  Further, two rubber bands 26 a and 26 b (= band, closing means) are wound around the outer surface of the multilayer unit 24. Specifically, on the mesh holder 24c described above, of the two mesh holders 24c, upstream from the holder opening 24c1 on the upstream side in the gas flow direction and downstream from the holder opening 24c1 on the downstream side in the gas flow direction. It is wrapped around

  If the multi-layer unit 24 having the above configuration is accommodated in the intermediate flow path portion 22 between the intermediate flow path body 22b and the upper lid 22c, the inner surface of the intermediate flow path portion 22 and the multi-layer unit as shown in FIG. The gap C between the outer surface 24 and the outer surface 24 can be closed by the rubber bands 26a and 26b, so that gas can be prevented from flowing to the gas outlet 12 through the gap C. As a result, no gas flows out of the multilayer unit 24 from the gap C, and all the gas passes through the measurement flow path divided by the rectifying plate 24b in the multilayer unit 24. Flow rate measurement characteristics will not vary.

  3A is a cross-sectional view taken along the line II of the electronic gas meter shown in FIG. 1, and FIG. 3B is a cross-sectional view taken along the line II-II of FIG. According to the gas meter described above, as shown in FIG. 3, the rubber bands 26a and 26b are formed with the gaps Cl and Cr formed in both the left inner surface 22d and the right inner surface 22e in the gas flow direction Y1 of the central flow path portion 22. Closes the gaps Cl and Cr. As a result, the multilayer unit 24 can be arranged in the center between the left inner surface 22d and the right inner surface 22e of the central flow path portion 22, and the arrangement position does not vary from product to product. Variations in flow velocity measurement characteristics can be reduced.

  As is clear from the above, the rubber bands 26a and 26b located on the left side surface of the multilayer unit 24 serve as a left plug means for closing the gap Cl between the left inner surface 22d of the central flow path portion 22 and the outer surface of the multilayer unit 24. It can be seen that the rubber bands 26 a and 26 b located on the right side surface of the multilayer unit 24 correspond to a right closing means for closing the gap Cr between the right inner surface 22 e of the central flow path portion 22 and the outer surface of the multilayer unit 24.

  Further, according to the gas meter described above, the rubber band 26a is provided on the downstream side of the two mesh holders 24c with respect to the holder opening 24c1 of the mesh holder 24c on the upstream side, and the rubber band 26b is disposed on the downstream side. The mesh holder 24c is provided downstream of the holder opening 24c1.

  That is, of the two ultrasonic sensors, the rubber band 26a closes the gap C on the upstream side of the ultrasonic sensor provided on the upstream side in the gas flow direction, and the rubber band 26b is provided on the downstream side in the gas flow direction. It is provided so as to close the gap C downstream of the ultrasonic sensor. With the above configuration, the gas flow between the two ultrasonic sensors is not affected by the gap C, and the variation in flow velocity measurement characteristics can be further reduced.

  Further, according to the gas meter described above, the gap C is closed by the rubber bands 26a and 26b. Thereby, compared with the case where the sealing agent is applied to the gap C, the multilayer unit 24 can be easily removed even if it is necessary to remove the multilayer unit 24 from the intermediate flow path portion 22 by recycling or the like.

  By the way, although the mesh holder 24c is fixed by a claw or the like, some force is applied to the mesh holder 24c during the assembly of the gas meter, and the claw may come off and the mesh holder 24c may fall off the multilayer unit 24. There is. Therefore, as described above, if the rubber bands 26 a and 26 b are wound on the mesh holder 24 c, the rubber bands 26 a and 26 b can be used to make the mesh holder 24 c more difficult to disengage from the multilayer unit 24.

Second Embodiment In the first embodiment described above, the rubber bands 26a and 26b are used as the blocking means. For example, as shown in FIG. 4, the elastic convex portion 24f provided on the outer surface of the multilayer unit 24 is used. , 24g can be used as the closing means, and the same effect as the rubber bands 26a and 26b can be obtained. As shown in FIG. 5, the convex portions 24 f may be provided only on the upper surface and the left and right side surfaces of the multilayer unit 24 as long as the lower surface of the multilayer unit 24 and the intermediate flow path portion 22 can be arranged without gaps.

  By providing the convex portions 24f on the left and right side surfaces of the multilayer unit 24, a clearance Cl is formed on both the left inner surface 22d and the right inner surface 22e of the central flow path portion 22 as in the case of the rubber bands 26a and 26b shown in FIG. In the state where Cu is made, the gap C is closed by the convex portion 24f.

  Also in this case, similarly to the rubber bands 26a and 26b, the convex portion 24f is provided on the downstream side of the holder opening 24c1 of the mesh holder 24c on the upstream side of the two mesh holders 24c, and the convex portion 24g Is provided on the downstream side of the holder opening 24c1 of the mesh holder 24c on the downstream side, the variation in flow velocity measurement characteristics can be further reduced.

  Further, if the convex portions 24f and 24g are formed of a resin that is the same material as the multilayer unit 24, the convex portions 24f and 24g can be integrally formed with the multilayer unit 24, and the cost can be reduced.

  Furthermore, in the first and second embodiments described above, the gap C is closed using the rubber bands 26a and 26b and the convex portions 24f and 24g. However, if it is not necessary to remove the multilayer unit 24 from the intermediate flow path portion 22 due to recycling or the like, for example, a sealing agent may be applied to the gap to close the gap. In this case, if a sealant is applied to both the left and right side surfaces of the multi-layer unit 24, the gaps Cl and Cr are formed in both the left inner surface 22d and the right inner surface 22e of the central flow path portion 22, and the The gaps Cl and Cr can be closed.

It is a disassembled sectional view of the gas meter which incorporated the flow measuring device of the present invention in a 1st embodiment. It is a perspective view of the multilayer unit 24 which comprises the gas meter of FIG. (A) is the II sectional view taken on the line of the gas meter shown in FIG. 1, (b) is the II-II sectional view taken on the line shown in (a). It is a perspective view of the multilayer unit 24 which comprises the gas meter in 2nd Embodiment. It is sectional drawing of the multilayer unit 24 accommodated in the intermediate flow path part 22 and this intermediate flow path part 22 which comprise the gas meter in 2nd Embodiment. It is a fragmentary sectional view showing an example of the conventional electronic gas meter. (A) is the VI-VI sectional view taken on the line of the gas meter shown in FIG. 1, (b) is the VII-VII sectional view taken on the line shown in (a).

Explanation of symbols

20 Channel unit (gas channel)
22d upper inner surface 22e lower inner surface 24 multilayer unit (measurement flow path)
24c Mesh holder 26a Rubber band (band, closing means, right closing means, left closing means)
26b Rubber band (band, closing means, right closing means, left closing means)
Cl gap Cr gap C gap

Claims (6)

A gas flow path portion that forms a gas flow path that connects the gas flow inlet and the gas flow outlet, and two ultrasonic sensors that are housed in the gas flow path portion and are spaced apart from each other in the gas flow direction. A measurement flow path portion that forms a measurement flow path in which flow velocity measurement is performed, and a gap between the inner surface of the gas flow path section and the outer surface of the measurement flow path section is closed, and the gas that has passed through the gap flows into the gas outlet A flow path measuring device comprising a blocking means for preventing flow of
The blocking means is an upstream side of an ultrasonic sensor arranged upstream of the two ultrasonic sensors in the gas flow direction, and a downstream side of an ultrasonic sensor arranged downstream of the gas flow direction, A flow path measuring device provided in each of the above. The flow rate measuring device according to claim 1,
The flow measurement device, wherein the measurement flow path includes a rectifying plate that divides the measurement flow path. The flow channel measuring device according to claim 1 or 2,
The flow path measuring device, wherein the blocking means is composed of an elastic band wound around the outer surface of the measurement flow path section. The flow channel measuring device according to claim 1 or 2 ,
The flow rate measuring device, wherein the blocking means is an elastic convex portion formed on the outer surface of the measurement flow path portion. The flow path measuring apparatus according to claim 3,
The measurement channel section is provided on one surface forming the measurement channel, and a pair of openings provided for transmitting and receiving ultrasonic waves between the two ultrasonic sensors through the ultrasonic waves of the ultrasonic sensor. A pair of mesh holders that respectively close the openings,
The band is wound on the mesh holder. The flow rate measuring device according to claim 1 or 2,
The flow rate measuring device, wherein the blocking means is a sealant applied to a gap between the gas channel inner surface and the measurement channel portion outer surface.

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