JP4813173B2 - Membrane gas meter - Google Patents

Description

  The present invention relates to a membrane gas meter having a mechanism for converting a reciprocating motion of a measuring membrane in a measuring chamber into a rotational motion of a blade shaft, and in particular, a dropping prevention projection is formed between the reciprocating measuring membrane and a blade plate. Further, the present invention relates to a membrane gas meter that uses a vane plate on which a hinge frame and a drop-off prevention piece are formed, and is securely connected and has excellent assembly workability.

  A membrane gas meter is generally used as a gas meter for small and medium flow rates for city gas. The membrane gas meter is designed to discharge gas from both sides of the measuring membrane alternately to the outside of the main body case by the reciprocating motion of the measuring membrane built in the two measuring chambers inside the main body case. The mechanism is converted into a rotary motion using a mechanism, and a gas is distributed by driving a slide valve, and an integrated flow rate is displayed by driving a counter.

FIG. 8 is a partially broken front view showing a membrane gas meter, and FIG. 9 is a side sectional view of the same.
The casing of the membrane gas meter has a main body case constituting the lower part and an upper case constituting the upper part, and a gas inlet 12 and a gas outlet 15 are provided in the upper case. The lower space provided inside the main body case and the upper space provided inside the upper case are partitioned by a partition wall, and the lower space is partitioned into a front weighing chamber 1a and a rear weighing chamber 1b. ing. In the front weighing chamber 1a, first and second weighing chambers (a) and (b) are formed by the weighing membrane 7a, and in the rear weighing chamber 1b, the third and fourth weighing chambers (c) and (d) are formed by the weighing membrane 7b. ) Is formed. The reciprocating motion of the measuring membranes 7a and 7b is transmitted to the blade plate 3 via the hinge frame 5 attached by the membrane plates 8 and 8 attached to both surfaces of the measuring membrane, and the swinging of the blade plate 3 is further controlled by the blades. It is transmitted to the shaft 2 and the link mechanism 16 to drive the valve 13 and drive the flow rate integrating mechanism.

FIG. 10 is a diagram showing the operating principle of the membrane gas meter.
The gas flowing in from the gas inlet 12 passes through the valve 13 and the distribution chamber 14, and any one of the first to fourth measuring chambers (a), (b), (c), and (d) of the front and rear measuring chambers 1a and 1b. It flows into the crab. Here, as shown in FIG. 10 (A), suppose that gas flows into the first measuring chamber (a) of the front measuring chamber 1a, and the measuring membrane 7a moves by the pressure of the flowing gas at this time, The gas in the opposing second measuring chamber (A) partitioned by the membrane 7a is discharged. The discharged gas passes through the gas outlet 15 from the distribution chamber 14 and the valve 13 and is discharged out of the gas meter. Further, the movement of the measuring film 7a is converted into a swinging motion of the blade plate 3 and is transmitted to the link mechanism 16 via the blade shaft 2 to drive the flow rate integrating mechanism of the gas meter and to drive the valve 13.

  By rotating the valve 13 by a predetermined angle, the flow path between the valve 13 and the distribution chamber 14 is switched, and as shown in FIG. 10B, the gas flowing into the gas meter is in the fourth measuring chamber (E) in the rear measuring chamber 1b. ) And the gas in the third measuring chamber (c) is guided to the gas outlet 15 and discharged. As a result of the series of operations described above, as shown in FIGS. 10A to 10D, the measuring chamber through which the gas enters and exits is switched in the order of (A) → (E) → (I) → (C). 7a and 7b continue to reciprocate, and gas is metered. Thus, in order to convert the reciprocating motion of the measuring membranes 7 a and 7 b into the rotational motion of the blade shaft 2, the measuring membranes 7 a and 7 b are supported on the blade plate 3 by the membrane support structure using the hinge frame 5.

FIG. 11 is an exploded view of a conventional membrane support structure, and FIG. 12 is an assembled cross-sectional view.
In the conventional membrane gas meter, the supporting structure of the measuring membrane 7 and the blade plate 3 is such that a hinge frame 21 having a shaft through hole 17 is formed on a pair of membrane plates 8a and 8b sandwiching the measuring membrane 7 with screws or the like. The hinge frame 21 is disposed between a pair of opposed through holes 4 a and 4 b formed at one end of the blade plate 3, and is inserted into the through hole 17 of the hinge frame 21 and the through holes 4 a and 4 b of the blade plate 3. The measurement shaft 7 is supported by penetrating the hinge shaft 18. Further, the hinge frame 21 is integrally formed with a drop prevention protrusion 19, the hinge shaft 18 is formed with a concave shape 20, and the drop prevention protrusion 19 of the hinge frame 21 is fitted into the concave shape 20 of the hinge shaft 18. The hinge shaft 21 is prevented from falling off.

Further, as a conventional example in which the supporting structure of the measuring membrane and the blade plate is different, a measuring membrane bearing retaining structure described in Patent Document 1 is known. In this measuring membrane bearing retaining structure, in the bearing retaining structure in which the bearing is engaged with the shaft at the tip of the blade plate and the bearing is screwed to the center portion of the membrane plate sandwiching the measuring membrane from the front and rear, By providing anti-rotation means for restricting the rotation of the bearing around the center of the bearing and at least one of the membrane plates, it is possible to prevent loosening of the screw tightening that causes a measurement error.
JP-A-2005-227209

  In the conventional membrane gas meter as described above, the membrane support structure for attaching the measurement membrane to the blade plate is composed of three members, a hinge frame, a hinge shaft, and a blade plate, and the hinge frame is opposed to one end of the blade plate. Since the structure is such that the hinge shaft is inserted and assembled between the shaft through holes, the number of steps in assembling the meter is large, and the operation is not easy. Accordingly, an object of the present invention is to simplify the support structure for attaching the metering membrane to the wing plate, and to facilitate the assembly work of the membrane gas meter.

  Also, since the support structure of the metering membrane transmits the reciprocating motion of the metering membrane to the wing plate, play in the membrane support structure causes a metering error. In the conventional membrane gas meter membrane support structure, the measurement membrane support structure consists of three members: a hinge frame, a hinge shaft, and a wing plate. Since there are many members, there is a lot of play, and the reciprocating motion of the measurement membrane is accurate. It was not transmitted to the sensor, causing the measurement accuracy to decrease. Therefore, the present invention aims to reduce the play of the membrane support mechanism as much as possible, and aims to reduce the number of constituent members by integrating a plurality of constituent members and reduce the cost.

  The invention according to claim 1 is a membrane gas meter having a measuring chamber partitioned by a reciprocating measuring membrane and transmitting the reciprocating motion of the measuring membrane to a blade shaft through a hinge frame and a blade plate. Is substantially U-shaped, has a hinge shaft on each of the engagement pieces standing upright from the base attached to the measurement membrane, and has a drop-off preventing projection on the base facing one of the hinge shafts, The blade has a through-hole and a drop-off preventing piece around the through-hole, and when the meter is assembled to insert the hinge shaft of the hinge frame into the through-hole of the blade, the drop-off preventing protrusion and the drop-off are provided. The prevention pieces do not interfere with each other, and within the range in which the hinge frame reciprocates when the meter is used, the angle and width of the drop prevention pieces are formed so that the drop prevention protrusions interfere with the drop prevention pieces. It is characterized by.

  According to a second aspect of the present invention, in the membrane gas meter according to the first aspect, the hinge frame, the hinge shaft and the drop-off preventing protrusion are integrally formed.

  According to the present invention, when assembling the membrane gas meter, the hinge shaft of the hinge frame is inserted into the shaft through hole at one end of the blade plate, and the hinge frame is rotated to the range of the hinge frame reciprocating motion in the actual use state of the membrane gas meter. It is possible to prevent the hinge frame from coming out of the wing plate by simply making it, the assembly work is easy, and the measuring membrane can be securely supported and fixed to the wing plate. On the other hand, if the hinge frame is rotated until the membrane gas meter is assembled, the hinge frame can be easily removed from the blade.

  Further, according to the present invention, since the membrane support structure is composed of two members, the blade plate and the hinge frame, play of the support structure can be reduced, and the reciprocating motion of the measurement membrane can be accurately transmitted to the blade plate. Therefore, the metering accuracy of the meter can be improved. Moreover, since the number of members can be reduced, a membrane gas meter can be provided at low cost.

Hereinafter, a membrane gas meter of the present invention will be described based on the embodiment shown in FIGS.
FIG. 1 is a side sectional view showing a membrane support structure in a membrane gas meter of the present invention. The membrane support structure shown in FIG. 1 shows the membrane support structure in the front and rear measurement chambers 1a and 1b of the membrane gas meter shown in FIG. 8, but the front and rear measurement chambers 1a and 1b have the same structure. The front weighing chamber will be described.

  The front measuring chamber 1 (1a) of the membrane gas meter has a first measuring chamber (A) and a second measuring chamber (I) partitioned by a measuring membrane 7 (7a) before and after the meter body. A rotatable blade shaft 2 is inserted into the measuring chamber 1. One end of the blade plate 3 is fixed to the blade shaft 2, and hinge shafts 6 a and 6 b integrally formed with the hinge frame 5 are inserted into shaft through holes 4 a and 4 b (see FIG. 3) provided at the other end of the blade plate 3. Thus, it is supported rotatably. The hinge frame 5 is attached to a pair of membrane plates 8a and 8b sandwiching the measuring membrane 7 from both sides by screws or the like. The measuring film 7 can reciprocate in the measuring chamber 1. FIG. 1 shows that the gas is introduced into the first measuring chamber (A), the measuring membrane 7 indicated by the dotted line is bent toward the second measuring chamber (A) indicated by the solid line, and the inside of the second measuring chamber (A) is The state where the gas is discharged out of the meter body is shown.

FIG. 2 is a perspective view showing the appearance of the hinge frame.
The hinge frame 5 is attached to the measuring membrane 7 via a pair of membrane plates 8a and 8b sandwiching the measuring membrane 7 between the front and back surfaces, and is used to transmit the reciprocating motion of the measuring membrane 7 to the wing plate 3. It has a letter-like appearance, and its base and the membrane plates 8a and 8b are fixed using a fixing tool such as a screw. Further, engaging pieces 11a and 11b are provided opposite to both ends of the base portion of the hinge frame 5, and the hinge shafts 6a and 6b are integrally formed from the engaging pieces 11a and 11b in one direction parallel to the base portion. To do. Further, at the base of the hinge frame 5, a drop-off preventing projection 9 is integrally formed at a position facing the one hinge shaft 6b.

FIG. 3 is a perspective view showing an external appearance of a blade plate coupled to the blade shaft.
The wing plate 3 is for transmitting the reciprocating motion of the hinge frame 5 to the wing shaft 2, and one end is coupled to the wing shaft 2 and the other end is coupled to the hinge frame 5 to be freely rotatable. The rising pieces are bent at both side edges of the blade plate 3, and shaft through holes 4a and 4b are formed at the leading ends of the rising pieces. Around the portion where the shaft through holes 4a and 4b are formed, drop-off preventing pieces 10a and 10b are integrally formed to prevent the hinge frame 5 from falling off the blade plate 3 after the assembly of the membrane gas meter. Yes.

  The drop-off prevention protrusion 9 integrally formed on the base of the hinge frame 5 and the drop-off prevention pieces 10a and 10b integrally formed around the shaft through holes 4a and 4b of the blade plate 3 have the following angles and widths. Designed to. In other words, when the hinge shafts 6a and 6b of the hinge frame 5 are inserted into the shaft through holes 4a and 4b of the vane plate 3 in the assembling work of the membrane gas meter, the position of the drop prevention protrusion 9 and the drop prevention piece 10 is shifted. The hinge shafts 6a and 6b can be inserted without interfering with each other, and the drop-off preventing projection 9 and the drop-off preventing piece are provided in the reciprocating motion range of the hinge frame 5 in the actual use state after the membrane gas meter is assembled. 10 are overlapped and interfered so that the hinge frame 5 cannot come out of the blade plate 3 (A), the height of the drop-off prevention protrusion 9 (B), the height of the drop-off prevention piece 10 (B), the shaft through hole 4a, The angle (θ) at which the drop-off prevention piece 10 is formed with respect to 4b is set (see FIG. 5).

FIG. 4 is a cross-sectional view showing a reciprocating range of the measurement membrane in the actual use state of the membrane gas meter, and FIG. 5 is an enlarged view showing a portion A of FIG.
FIG. 4 shows that the gas is introduced into the first measuring chamber (A) in the state indicated by the dotted line, the measuring membrane 7 is bent toward the second measuring chamber (A) indicated by the solid line, and the second measuring chamber (A) The gas inside is discharged outside the meter body. Thus, in the actual use state of the membrane gas meter, the range in which the measurement membrane 7 reciprocates is from the state indicated by the dotted line to the state indicated by the solid line. On the other hand, at the time of assembling the membrane gas meter, the blade plate 3 is further rotated from the state indicated by the dotted line (see FIG. 6).

  A state indicated by a solid line filled with gas in the first measuring chamber (A), a state indicated by a dotted line filled with gas in the second measuring chamber (A), and a state indicated by a dotted line from the state indicated by the solid line In the hinge frame reciprocating motion range in the actual use state up to, as shown in FIG. Is done.

FIG. 6 is a cross-sectional view showing the positional relationship between the blades and the metering membrane when the meter is assembled, and FIG. 7 is an enlarged view showing a portion B of FIG.
At the time of assembling the meter, the measuring film 7 and the hinge frame 5 are pre-assembled with film plates 8a and 8b, screws, and the like. Further, as shown in FIG. 6, the blade shaft 2 and the blade plate 3 have a posture in which the blade plate 3 stands up around the blade shaft 2, and the central axes of the shaft through holes 4 a and 4 b formed in the blade plate 3. And the central axes of the hinge shafts 6a and 6b formed on the hinge frame 5 are made to coincide with each other, and then the hinge shafts 6a and 6b are inserted into the through-holes 4a and 4b together with the measuring membrane 7. At this time, when the hinge shafts 6a and 6b of the shaft through holes 4a and 4b are inserted, the drop prevention protrusion 9 and the drop prevention piece 10 do not interfere with each other, and the hinge shafts 6a and 6b are easily inserted into the shaft through holes 4a and 4b. can do.

It is a sectional side view which shows the film | membrane support structure in the film | membrane type gas meter of this invention. It is a perspective view which shows the external appearance of a hinge frame. It is a perspective view which shows the external appearance of the blade board couple | bonded with the blade axis | shaft. It is sectional drawing which shows the reciprocating range of the measurement film | membrane in the actual use condition of a membrane type gas meter. It is an enlarged view which shows the A section of FIG. It is sectional drawing which shows the positional relationship of the wing plate at the time of meter assembly, and a measurement film | membrane. It is an enlarged view which shows the B section of FIG. It is a partially broken front view showing a membrane gas meter. It is a sectional side view showing a membrane type gas meter. It is a figure which shows the operating principle of a membrane type gas meter. It is an exploded view of the conventional membrane support structure. It is assembly sectional drawing of the conventional film | membrane support structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Measurement chamber, 2 ... Blade shaft, 3 ... Blade plate, 4 ... Shaft through hole, 5 ... Hinge frame, 6 ... Hinge shaft, 7 ... Measurement film, 8 ... Membrane plate, 9 ... Drop-off prevention protrusion, 10 ... Drop-off Prevention piece, 12 ... gas inlet, 13 ... valve, 14 ... distribution chamber, 15 ... gas outlet, 16 ... link mechanism.

Claims (2)

In a membrane gas meter having a measuring chamber partitioned by a reciprocating measuring membrane, and transmitting the reciprocating motion of the measuring membrane to a blade shaft through a hinge frame and a blade plate,
The hinge frame has a substantially U-shape, each of the engaging pieces standing upright from the base attached to the measuring membrane has a hinge shaft, and a drop-off preventing projection is provided on the base opposite to one of the hinge shafts. And the vane plate has a through-hole and a drop-off preventing piece around the through-hole, and the drop-out prevention protrusion is inserted when the hinge shaft of the hinge frame is inserted into the through-hole of the vane plate. In the range where the hinge frame reciprocates when the meter is used, the angle and width of the drop-off prevention piece are formed so that the drop-off prevention protrusion and the drop-off prevention piece interfere with each other. A membrane-type gas meter characterized by The membrane gas meter according to claim 1, wherein
The membrane gas meter according to claim 1, wherein the hinge frame, the hinge shaft and the drop-off preventing projection are integrally formed.

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