JP4796349B2 - Membrane gas meter - Google Patents

Description

  The present invention provides at least a pair of measuring spaces partitioned by a film portion provided in a measuring chamber, a supply unit for supplying gas to the measuring space, or for supplying and discharging gas from the measuring space. And a valve portion capable of controlling the supply and discharge of gas to and from the metering space in cooperation with the distribution portion, and the membrane portion reciprocates in accordance with the supply and discharge of gas to and from the metering space. A membrane gas meter in which the relative posture between the valve provided in the valve portion and the valve seat portion provided in the distribution portion is changed according to the movement to control the supply and discharge of gas to and from the measurement space. The present invention relates to a sliding portion formed in a valve and a valve seat portion.

  The membrane gas meter is provided with a pair of measuring spaces with a membrane portion interposed therebetween, and supplies gas supplied to the meter to one of these measuring spaces, and in this supply state, the other measuring space is in that space. The amount of gas passing through the meter is measured by discharging the gas and detecting the reciprocating motion of the membrane part accompanying the supply / discharge of this gas.

  The supply / discharge of gas to / from each of the measuring spaces is performed by taking the reciprocating motion of the membrane portion as the oscillating blades and blade shafts connected to the membrane portion, and this oscillating motion via the link mechanism. The valve is operated by being transmitted to a valve provided in the section. According to this valve operation, the measurement space connected in communication with the gas supply port of the meter and the measurement space connected in communication with the gas discharge port of the meter are switched, so that the reciprocating motion of the membrane portion is caused by the gas flowing through the meter. Can be maintained well.

Now, as this type of membrane gas meter, a valve oscillating meter (Patent Documents 1 and 2) having a fan-shaped valve as a valve shape, and a valve rotation type meter having a dome-shaped valve (valve shape) ( Patent Document 3) is known.
In a valve swing meter, a fan-shaped valve swings around a predetermined axis with its lower surface in contact with the valve seat portion, and for a long period of time when the valve and valve seat portion slide relative to each other. used. On the sliding surface between the valve and the valve seat portion, a certain sealing property and sliding property are required to guide the gas to a predetermined measuring space.
Conventionally, a carbon-containing phenol resin has been adopted as a constituent material for the valve and the valve seat portion. The material of these parts has been able to ensure the sealing performance and sliding performance of the sliding surface over a predetermined lifetime. That is, material selection centering on life has been performed.

  In the valve swing type meter, the material of the valve and valve seat part is a carbon-containing phenol resin having a carbon content of 36% by mass in terms of mass ratio, and the surface roughness of the sliding surface (according to the present application). The surface roughness means the maximum height Rmax, and when the extracted portion is sandwiched by two straight lines parallel to the average line of the portion extracted from the sectional curve by the reference length, the interval between the two straight lines is defined as the vertical length of the sectional curve. The value was measured in the direction of magnification and the value was expressed in units of microns. The so-called peak-to-peak height) was 10 μm. The above-mentioned reference length is 2.5 mm when the surface roughness is over 6.3 and 25 μm or less, and is 0.8 mm when the surface roughness is over 0.8 and 6.3 μm or less. .

With regard to the above-described valve rotation type meter, the material and surface roughness of the valve and valve seat are in accordance with the standards of the swing type meter.
JP 2001-201383 A JP 2001-188019 A Japanese Utility Model Publication No. 33-23086

  Now, as a membrane gas meter, comparing the oscillating meter and the rotary meter, the latter has a smaller number of valves, so the rotary meter can reduce the area occupied by the peripheral mechanism of the valve. It is possible to reduce the volume of the meter body while maintaining the same pressure (maximum flow rate used) while keeping the specified pressure loss. However, when trying to meter the same amount of gas, the peripheral speed of the valve increases (for example, about 1.5 times), and wear of the sliding surface advances.

As described above, in the membrane gas meter, the reciprocating motion of the membrane part causes relative movement in the sliding state between the valve and the valve seat part, and controls the supply and discharge of gas to and from the measurement space. . The membrane part and the valve are configured so as to be linked via a blade, a blade shaft, and a link mechanism, and the sliding torque required for the rotation of the valve rises as the wear progresses to some extent after repeated sliding. . If this situation progresses excessively, in the worst case, the possibility that the sliding surface sticks and does not move cannot be denied.
On the other hand, as the sliding surface becomes rougher, the sliding torque increases as the number of sliding times increases.
In particular, in a membrane gas meter, the reciprocation of the membrane part involved in metering and the valve operation that controls the supply and discharge of gas to and from each metering space are closely related. When the sliding torque is increased, the pressure loss accompanying the passage of gas through the meter increases or becomes unstable, which is not preferable. Furthermore, it has been found that noise accompanying sliding may occur.

  An object of the present invention is to provide a membrane gas meter that can stabilize the metering performance and suppress the generation of noise even when used for a long period of time.

To achieve the above object, according to the present invention, at least a pair of measuring spaces partitioned by a membrane portion provided in a measuring chamber, supply of gas to the measuring space, or supply of gas for discharging from the measuring space A distribution unit having an exhaust path, and a valve unit capable of controlling gas supply / exhaust to the measurement space in cooperation with the distribution unit, and the membrane unit reciprocates according to gas supply / discharge to the measurement space. In the configuration to
According to the reciprocating motion of the membrane part, the relative posture between the valve provided in the valve part and the valve seat part provided in the distributing part and on which the valve slides is changed to supply and discharge gas to the measuring space. The first characteristic configuration of the membrane gas meter in which is controlled is
Fibrous at least one of the sliding surface of each of the valve and the valve seat portion, a phenol as the main material, the content of carbon fiber for the phenol is not more than 52 wt% or more 37 wt% in mass ratio Made of carbon- containing phenolic resin,
The surface roughness of the sliding surface is 1 μm or more and 8.5 μm or less.

The operation and effect obtained by providing the first characteristic configuration will be described with reference to FIGS.
FIG. 11 shows a torque increase value (a torque increase value from the initial stage after 1000 hours (N · cm): left axis) with respect to the carbon content with respect to the carbon-containing phenol resin, which is a constituent material of the valve or the bubble seat part, The noise level (dB: right axis) is shown.
FIG. 12 shows the torque increase value (torque increase value from the initial stage after 1000 hours (N · cm): left axis) with respect to the surface roughness (μm) of the sliding surface of the valve or bubble sheet portion. .

As can be seen from FIG. 11, the torque increase rate tends to decrease as the carbon content rate increases in relation to the carbon content rate, and the noise level tends to increase as the carbon content rate increases. Therefore, the carbon content can be determined according to these two evaluation criteria.
That is, the inventors set the standard of the rate of increase in torque (N · cm) from the beginning after 1000 hours to 0.09 N · cm and the standard of noise level to 40 dB. Here, the torque increase rate is a standard that can be derived based on the allowable value of the pressure loss increase at the time of gas passage, which is a critical condition in the membrane gas meter, and the noise level is, for example, quiet at night. At times, the noise level is such that a person in the vicinity of the meter does not care.

  As can be seen from FIG. 11, according to the above criteria, both the torque increase value and the noise level can be suppressed by setting the carbon content to 37 mass% or more and 52 mass% or less. Below this lower limit, an increase in torque occurs, leading to excessive pressure loss. Exceeding this upper limit is undesirable because noise increases.

  With respect to this carbon content, it is more preferable to set it to 40% by mass or more and 52% by mass or less. In this case, the lower limit value is increased, but the torque increase can be further suppressed, and stable meter operation can be secured.

As can be seen from FIG. 12, the surface roughness is related to the torque increase. That is, regarding the surface roughness of the sliding surface, the torque increase value converges to a constant value in a region where the surface roughness is small (for example, a region of 3 μm or less), while in the region where the surface roughness is higher than that, the surface As the roughness increases, the torque increase value increases monotonously.
Then, the upper limit of the torque increase value previously determined based on the pressure loss is exceeded. Therefore, the upper limit of the surface roughness is set to 8.5 μm. On the other hand, regarding the lower limit, it is considered that the effect of surface roughness on the torque increase is small, but if this surface roughness is less than 1 μm, the space between the valve and the valve seat becomes narrow, and condensation occurs due to capillary action. It becomes easy to do. Therefore, the lower limit is set to 1 μm.

  With respect to this surface roughness, if the lower limit value is 2 μm and the upper limit value is 6 μm, it is possible to suppress the increase in torque in a stable region with relatively rough machining accuracy. With respect to, the torque increase can be further suppressed, and stable meter operation can be secured.

Now, it is the form of carbon contained in the phenol resin, but if carbon is contained as this carbon, the strength of the resin itself can be increased and the wear resistance is improved. Can be made.

In the description so far, there has been nothing about the type of membrane gas meter (difference between swing type and rotary type), but the present application is a rotary type in which the valve rotates around the central axis. This is particularly preferable in the case of a membrane gas meter.
That is, when a membrane type gas meter having a ring-shaped sliding surface is provided with a rotary valve that rotates around the central axis in accordance with the reciprocation of the membrane part and controls supply and discharge of gas to and from the measurement space, As described above, even when the meter itself is small and the sliding relative speed increases, the pressure loss of the meter is set to a suitable predetermined value while suppressing the increase in torque and the generation of noise. Stable weighing can be performed while keeping within the range.

Embodiments of the present invention will be described with reference to the drawings.
1 is a partial cross-sectional front view of a membrane gas meter M according to the present application, FIG. 2 is a partial cross-sectional side view of the membrane gas meter M, and FIG. It is a perspective view.

As shown in FIG. 1, the membrane gas meter M is configured by connecting an upper casing UC to the upper side of the lower casing LC, and a gas supply port I and a gas discharge port O are provided at the upper left and right positions of the upper casing UC. It is configured with.
As shown in FIG. 2, both casings LC and UC are assembled, and the inside of the casing C becomes an airtight container with the front opening FO and the rear opening BO of the lower casing LC covered with a cover c. U is fixedly disposed on the inner upper portion of the lower casing LC so that the space above the distribution unit U in the upper casing UC serves as the supply chamber SS, and the lower side of the distribution unit U in the lower casing LC. Is a pair of weighing chambers S.

  A gas to be measured is supplied from the gas supply port I to the supply chamber SS. Further, in the example shown in FIG. 1, a gas discharge path forming member communicated with the gas discharge port O in a state separated from the space in which the gas to be measured is supplied in the supply chamber SS. 1 is disposed on the right side of FIG. 1, and the gas on the discharge side is led to the gas discharge port O from the gas discharge path sp <b> 2 provided in the distribution unit U.

  In the supply chamber SS, a counter unit CP is provided for counting the measured value of gas measured as the rotational speed of the rotary valve RV. As shown in FIGS. 1 and 2, the counter portion CP is configured such that the rotation of the rotary valve RV can be taken out by a worm w provided on the counter shaft Ca and a worm wheel wh meshing with the worm w. Is displayed on a counter provided on the front surface of the casing C. In addition, in the upper casing UC, an emergency shut-off valve ESV (see FIG. 1), a control unit CPU (see FIG. 2) for controlling the operation state of the entire membrane gas meter, and the like are arranged.

  With respect to the inside and the outer surface of the lower casing LC, the left side cross section in FIG. 1 is a cross section that clearly shows the arrangement of the blade axis f1 provided to the membrane part F and its support structure, and the right side view is the upper side. It is divided into three parts from the bottom to the bottom. The upper part is a diagram showing the configuration of the distribution unit U including the rotary valve RV, the middle part is a diagram showing the configuration of the membrane part F, and the lower part shows the state of the outer surface of the lower casing LC. ing.

  As can be seen from FIG. 2, the lower casing LC is formed with a circular front opening FO and a rear opening BO on the front side and the rear side thereof, and covers the openings FO and BO respectively. The structure covered with is adopted. Further, the inside of the lower casing LC is divided into a pair of front and rear weighing chambers S by a partition wall LC1 provided at a central portion in the front-rear direction. Each of the pair of measuring chambers S is provided with a film part F.

As shown in FIG. 2, the film portion F includes a film body f2, a circular film plate f3 held at the center of each of both surfaces of the film body f2, and a hinge stand f4 held at the center of the outer film plate f3. The film part F is sandwiched between the peripheral part of the film body f2 and the peripheral part of the hole of the film holding frame part LC2 by the frame-shaped film adjusting plate f5. It is assembled to the attachment base LC3.
Therefore, as schematically shown in FIG. 9, each weighing chamber S is formed with a pair of weighing spaces s before and after the membrane portion F, and a total of four weighing spaces s are provided.

  As shown in FIG. 1, an arm-like wing f6 extending in the left direction of the membrane gas meter M is connected to a hinge base f4 provided in the membrane portion F, and the base end of the wing f6 is connected to the blade axis f1. It is fixedly connected. Accordingly, as the film portion F reciprocates in the front-rear direction of the meter M, the blade axis f1 swings as shown by an arc-shaped arrow in FIG. As shown in FIG. 1, the blade shaft f1 is supported by a blade shaft support portion LC4 provided in the lower casing LC, and a configuration is adopted in which the upper end thereof enters the upper casing UC. As shown in the figure, a gas flow is not generated between the measuring chamber S and the supply chamber SS by a seal portion f7 through which the blade shaft f1 is rotatably inserted.

  Hereinafter, the configuration of the distribution unit U that partitions the supply chamber SS and the measurement chamber S will be described. The distribution unit U is connected to a predetermined portion in the lower casing LC, and divides the space in the casing into a supply chamber SS and a measuring chamber S. Further, the distribution unit U includes a distribution member sp1 having a valve portion VP in which the rotary valve RV is disposed, and a valve seat portion VS provided in sliding contact with the rotary valve RV so as to face the lower side thereof. A distribution unit SP configured as a main body is provided.

FIG. 3 shows an assembled state of the distribution member sp1, the rotary valve RV, and the link mechanism L connected to the rotary valve RV via a crank K, and FIG. 4 is a sectional view thereof. The rotary valve RV is supported so as to be rotatable around a central axis X that is pivotally supported by the distribution member sp1.
Further, FIG. 5 shows the state of the opening provided in the valve seat portion VS provided on the upper surface of the distribution member sp1, and FIG. 6 is a plan view of the rotary valve RV as viewed from above. These are the bottom views which looked at this rotary valve RV from the lower side.

  As will be understood from FIGS. 4, 6, and 7, the rotary valve RV is provided with a gas supply path rv <b> 1 that penetrates the valve RV in the vertical direction, and the metering space s from the valve seat portion VS located on the lower side. A gas discharge path rv2 is provided for receiving the gas in the interior, guiding it to the rotational center side of the rotary valve RV, and returning it to the valve seat part VS.

  On the other hand, as can be seen from FIGS. 4 and 5, the distribution member sp1 is provided with a gas discharge path sp2 leading from the rotation center side position of the rotary valve RV to the one end side in the right direction of the distribution member sp1. The downstream end of the gas discharge path sp2 is configured to open upward, and the gas outlet port sp3 is connected to the gas discharge port O provided in the upper casing UC on the lower discharge side, so that the measurement space The gas in S can be discharged out of the casing C.

  The distribution member sp1 has a square shape in plan view as shown in a perspective view in FIG. 3, and has a plurality of hanging portions sp1a extending downward as can be seen from FIG. The rotary valve RV is rotatably disposed around the central axis X on the upper side of the distribution member sp1, and the gas connected to the gas discharge port O is connected to the right end portion thereof. The outlet sp3 is provided. Further, as shown in FIG. 1, the distribution member sp1 is provided with a support portion sp4 for supporting the counter portion CP from the lower side as described above.

As shown in FIG. 5, inside the valve seat portion VS, there are four supply / discharge openings vs1 called by the inventors as an annular supply / discharge opening group, and the central axis X side from the annular supply / discharge opening group. A discharge opening vs2 is located.
As shown schematically in FIGS. 4 and 9, the supply / discharge opening vs1 is individually connected to four measurement spaces s through individual gas supply / discharge passages vs3. The four arcuate supply / discharge openings vs1 are provided so as to be arranged in an annular shape with their phases shifted by 90 °.
The discharge opening vs2 is open on the rotary valve RV side disposed on the upper side, and is discharged from the gas discharge path rv2 provided in the rotary valve RV to the gas discharge path sp2 provided in the distribution member sp1. This gas is received and connected to the gas outlet port O through a gas discharge path sp2 provided in the distribution member sp1.

Based on FIG. 4, the connection relationship between the gas supply path rv1 and the gas discharge path rv2 provided in the rotary valve RV and the supply / discharge opening vs1 and the discharge opening vs2 will be described below.
The lower opening of the gas supply path rv1 provided in the rotary valve RV is arranged so as to sequentially overlap the four supply / discharge openings vs1 as the rotary valve RV rotates. Therefore, in a state where this lower opening communicates with the specific gas supply / discharge path vs3, as shown in FIG. 9, the supply chamber SS communicates with the specific measurement space s, and the gas supplied from the gas supply port I is supplied to the supply chamber SS. The metric space s is supplied.

  On the other hand, as can be seen from FIGS. 4 and 7, the gas discharge path rv <b> 2 provided in the rotary valve RV is configured as a recess formed in the lower surface of the rotary valve RV, and is positioned facing the annular supply / discharge opening group. And an inner diameter side opening rv2b provided at a position facing the discharge opening sp2 of the distribution member sp1, and the openings rv2a and rv2b communicate with each other. ing. Therefore, the gas that has flowed into the outer diameter side opening rv2a can be guided to the inner diameter side opening rv2b, and can be guided into the gas discharge path sp2 in the distribution member sp1.

  The positional relationship between the lower opening of the gas supply path rv1 and the outer diameter side opening rv2a is a position facing each other across the central axis X, as can be seen from FIG.

  In the assembled state in which the rotary valve RV and the distribution member sp1 are integrated, the outer diameter side opening rv2a communicates with the specific supply / discharge opening vs1 in the environmental supply / discharge opening group. The metering space s communicated with the supply / discharge opening vs1 is communicated, gas is discharged from the metering space s, led to the inner diameter side through the gas discharge path rv2 in the rotary valve RV, and provided in the distribution member sp1. The gas is discharged into the gas discharge path sp2 and is led to the gas discharge port O provided on the lower side, and discharged out of the casing C.

  Here, since the positional relationship between the gas supply path rv1 and the outer diameter side opening rv2a is a facing relationship across the central axis X, the supply / exhaust opening where the gas supply path rv1 on the gas supply side overlaps. The supply / discharge opening vs1 at a position opposite to vs1 communicates with a gas discharge path sp2 provided in the distribution member sp1 for discharging gas. The communication connection relationship between the supply / discharge opening vs1 and each measurement space s is shown in FIG. 9 in the state where the gas is supplied to the measurement space s located on one side of one film part F. It is configured to be able to be connected alternately so that gas is discharged from the measuring space s located on the other side of the part F, and in accordance with the rotation of the rotary valve RV in the order shown in FIGS. Will operate. Regarding each figure, it can be seen that gas is supplied and discharged in the order of the left measuring chamber S, the right measuring chamber S, the left measuring chamber S, and the right measuring chamber S.

Hereinafter, the connection relationship using the link mechanism L between the rotary valve RV and the blade shaft f1 described above will be described with reference to FIGS.
The link mechanism L is for rotating the rotary valve RV by the swing of the blade shaft f1 that swings by the reciprocation of the pair of film portions F provided in the meter M. Is provided with two pairs of a large elbow L1 and a small elbow L2.
As shown in the figure, the base end side end of the large elbow L1 is connected to the upper end side portion of the blade axis f1, the ends of the two small elbows L2 are overlapped, and the overlapping portion is rotated by the connecting pin L3. The end portion of the crank K that rotates integrally with the valve RV is rotatably supported.
As a result, as shown in FIGS. 9 (a), (b), (c), and (d), in the state in which the film portion F reciprocates as the gas is supplied and discharged, this reciprocation is performed via the link mechanism L. It is transmitted to the valve RV and is operated as shown in FIGS. 10 (a), (b), (c) and (d) corresponding to FIGS. 9 (a), (b), (c) and (d).

  With the configuration described above, in a state in which gas is supplied from the supply chamber SS to the specific measurement space s, gas is discharged from the measurement space s that forms a pair with the measurement space s. With supply / discharge to S, the blade axis f1 swings, and the rotary valve RV rotates via the link mechanism L due to the swing. This rotation brings about a change in the gas supply / discharge path between the respective metering spaces s, so that the metering operation can be satisfactorily maintained. The rotation of the rotary valve RV is taken out by a counter portion CP provided in the upper casing UC, and the measured value can be confirmed from the outside by displaying the counter c1.

The above is the description of the measurement principle of the membrane gas meter M provided with the rotary valve RV. In the present application, the rotary valve RV and the valve seat portion VS on which the valve RV slides are pulled to determine the distribution member sp1. In addition to being made of a material unique to the present application, the surface roughness of the sliding surface is set to an appropriate level. FIG. 8 is an enlarged view showing the details of the state of the sliding surface.
That is, both members are molded from a carbon-containing phenol resin, and the carbon content is within a range of 37% by mass to 52% by mass. More specifically, the mass ratio was 44 to 50% by mass.
On the other hand, the surface roughness of the sliding surface that is in contact with the valve seat portion VS that is the lower end surface of the valve RV and the sliding surface that is the upper end surface of the valve seat portion VS is in the range of 1 μm to 8.5 μm. Yes. More specifically, the thickness was set to 2 to 4 μm.
By adopting such a configuration, the membrane gas meter M according to the present application can be a membrane gas meter having a low noise level without increasing torque.

Hereinafter, the sliding torque and noise test described above with reference to FIGS.
(Sliding torque test method)
The sliding torque test was performed according to the following procedure.
1 Measurement of torque required for initial valve rotation A weight (on the subject of this experiment, the area of the valve was 27 cm ² , so that a load corresponding to a pressure loss of 5 mmH ₂ O was applied to the valve was 13 The torque when the valve RV was rotated by the crank K of the link mechanism L was measured.
The valve rotation speed at the time of torque measurement was a valve rotation speed corresponding to a gas flow rate of 1000 L / h (the valve rotation speed at this time is 0.045 m / s).
2 Forced rotation The driving durability test was carried out under the following conditions by forcibly rotating the valve RV at a speed corresponding to twice the maximum flow rate (in this case, 12000 L / h). A weight (valve of the valve RV used in this experiment) is placed on the valve RV so that a load of pressure loss (in this case, 13 mmH ₂ O) is applied to the valve RV at the maximum gas use flow rate (in this case, 6000 L / h). Since the area was 27 cm ² , a weight of 35.1 g was used), and a load was applied to the valve RV, and the valve was forcibly continuously rotated by the crank K of the link mechanism L.
The forced continuous rotation speed was a valve rotation speed corresponding to twice the maximum gas flow rate (the valve rotation speed at this time was 0.54 m / s).
The continuous rotation time was 1000 hours.
3. Measurement of torque required for valve rotation after 1000 hours of continuous rotation After the valve was continuously rotated for 1000 hours at 0.54 m / s, the torque required for rotation of the valve was measured.
The measurement method was the same as in 1. The torque increase value after 1000 hours was calculated from the value of the torque after 1000 hours and the initial torque. The results were as shown by solid lines in FIGS.

(Noise test method)
Install a rotary valve in the gas meter, install a microphone for sound collection at a distance of 1m on the front side of the gas meter, and make a sound generated when air at the maximum flow rate (6000 L / h in this case) passes through the gas meter. It was measured. The result was as shown by a broken line in FIG.
[Another embodiment]
(1) In the above embodiment, the rotary type membrane gas meter provided with the rotary valve has been described. However, when the sliding speed is increased, the configuration of the present application is also adopted in the oscillation type membrane type gas meter. It is preferable to do.
(2) In the above embodiment, both the valve and the valve seat portion are made of the resin specified by the present application, and the surface roughness of the sliding surface is set within the range specified by the present application. Even if one of them is specified in the present application, it is possible to obtain a good result for the problem of the present application.
Furthermore, regarding the valve and the valve seat portion, the material and surface roughness constituting the sliding surface are those specified in the present application, and regarding the resin at a site away from the sliding surface, for example, any carbon content is low, etc. It is good also as a structure.

  Even when used over a long period of time, the metering performance was stable, and a membrane gas meter capable of suppressing the generation of noise could be obtained.

Partial sectional front view of a membrane gas meter according to the present application Partial sectional side view of a membrane gas meter according to the present application Perspective view of distribution unit as seen from above The figure which shows the state of the gas flow through a distribution unit The figure which shows the formation state of the supply / discharge opening and discharge opening in a valve seat part Plan view of rotary valve Bottom view of rotary valve Diagram showing the configuration near the lower end of the rotary valve The figure which shows the supply-exhaust state of the gas in the measurement space accompanying gas supply / exhaust Explanatory diagram of relationship between reciprocation of membrane and rotation of rotary valve Diagram showing the relationship between carbon content, torque increase rate and noise level Diagram showing the relationship between surface roughness and torque increase rate

Explanation of symbols

CP Counter part F Film part K Crank L Link mechanism LC1 Partition wall M Membrane gas meter S Metering chamber s Metering space SS Supply chamber RV Rotary valve rv1 Gas supply channel rv2 Gas discharge channel U Distribution unit SP Distribution unit sp1 Distribution member sp2 Gas discharge Road sp3 Gas outlet VS Valve seat part vs1 Supply / discharge opening vs2 Discharge opening vs3 Gas supply / discharge path VP Valve part

Claims (4)

At least a pair of measuring spaces partitioned by a membrane provided in a measuring chamber; a distributing unit having a supply / discharge path for supplying gas to the measuring space or discharging gas from the measuring space; and the distributing unit; A valve unit capable of controlling the supply and discharge of gas to and from the measurement space in cooperation with each other, and the film unit reciprocates according to the supply and discharge of gas to and from the measurement space
According to the reciprocating motion of the membrane part, the relative posture between the valve provided in the valve part and the valve seat part provided in the distributing part and on which the valve slides is changed to supply and discharge gas to the measuring space. Is a membrane gas meter controlled by
Fibrous at least one of the sliding surface of each of the valve and the valve seat portion, a phenol as the main material, the content of carbon fiber for the phenol is not more than 52 wt% or more 37 wt% in mass ratio Made of carbon- containing phenolic resin,
A membrane type gas meter in which the surface roughness of the sliding surface is 1 μm or more and 8.5 μm or less. The membrane gas meter according to claim 1, wherein a content ratio of the fibrous carbon to the phenol is 40 mass% or more and 52 mass% or less by mass ratio.   The membrane gas meter according to claim 1 or 2, wherein the sliding surface has a surface roughness of 2 µm to 6 µm. A rotary valve that rotates around the central axis in accordance with the reciprocating motion of the membrane portion and controls the supply and discharge of gas to and from the measurement space is provided as the valve.
The membrane gas meter according to any one of claims 1 to 3 , comprising the ring-shaped sliding surface.

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