JP2017194276A - Magnet fitting structure for magnetic sensor of crank mechanism in diaphragm gas meter, and fitting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure capable of easily and surely fitting a magnet for magnetic sensor.SOLUTION: A magnet fitting structure for magnetic sensor of a crank mechanism in a diaphragm gas meter is subjected. The magnet fitting structure for magnetic sensor comprises: a crank mechanism 4 in which a metallic upper-stage crankpin 45 is fitted to an upper-stage crank arm 44; a magnet pedestal 5 fitted to the upper-stage crankpin 45; and a magnet for magnetic senor fitted to the magnet pedestal 5. A rotation speed of the rotating magnet is detected via a magnetic sensor, and a gas flow rate is measured. The magnet pedestal 5 includes a metal plate part 51 made of a metal and a resin plate part 55 made of a synthetic resin, and the upper-stage crankpin 45 is fitted while being inserted into a pin fitting hole 52 of the metal plate part 51. The magnet is fitted to the resin plate part 5 via magnet fitting means.SELECTED DRAWING: Figure 3A

Description

  The present invention relates to a magnet mounting structure and mounting method for a magnetic sensor of a crank mechanism in a membrane gas meter for mounting a magnet for a magnetic sensor to a crank mechanism in a magnetic sensor metering type film gas meter.

  In the membrane gas meter, a metering membrane that reciprocates when gas enters and exits is provided in the metering chamber. The reciprocating motion of the metering membrane is transmitted to the crank mechanism by the power transmission mechanism, and the crank mechanism rotates. The gas flow rate is measured based on the rotation speed of the crank mechanism.

  In a mechanical metering type membrane gas meter such as a microcomputer meter, the rotation of the crank mechanism is transmitted to a mechanical counter via a mechanical power transmission mechanism such as a gear or a rotating shaft, converted into a gas flow rate, and displayed. I have to.

  On the other hand, in a magnetic gas meter (MR sensor) metering type gas meter such as a smart meter, a pedestal (magnet pedestal) for attaching a magnet is provided in the crank mechanism so as to face a magnet attached to the magnet pedestal. An MR sensor is arranged. The rotational speed of the magnet rotating with the crank mechanism is detected by an MR sensor, and the gas flow rate is calculated based on the rotational speed.

  For example, in an MR sensor metering type membrane gas meter shown in Patent Document 1 below, a crank mechanism with a magnet pedestal in which a magnet pedestal is attached to the crank mechanism is formed of an integrally molded product of plastic. When a mechanical metering type gas meter is improved to an MR sensor metering type gas meter, the crank mechanism in the mechanical metering type gas meter is replaced with the crank mechanism with a magnet pedestal so that an MR sensor metering type gas meter is obtained. I am trying to change it.

JP2015-206656A

  However, in the membrane gas meter shown in the above-mentioned Patent Document 1, a plastic integrally molded product in which a magnet pedestal is integrally formed in the crank mechanism is used, so that the molding die and the molding process itself are used. Expenses were high and there was a risk of increasing costs. For example, a gas meter with a large production quantity, for example, a small gas meter for general households, has a sufficient merit to adopt the above-mentioned integrally molded product, but a model with a small production quantity, for example, a store or a factory. When dealing with large or medium-sized gas meters, the use of the above-mentioned integrally molded product will not be profitable and will be disadvantageous.

  Therefore, for example, in an existing mechanical metering type membrane gas meter, only a magnet pedestal is separately attached to the crank mechanism to change to the MR sensor metering method.

  However, in the existing mechanical metering type gas meter, the main components such as the crankshaft, crank arm, and crankpin constituting the crank mechanism are made of metal and connected to each other by caulking. It is common. For this reason, when attaching a magnet pedestal to a mechanical weighing type crank mechanism, naturally, it is necessary to use a metal pedestal and attach it to the crank mechanism by caulking or the like.

  However, when a metal magnet pedestal is used, the magnet cannot be easily and reliably attached to the magnet pedestal in a stable state, and there is a problem that it is difficult to change to the MR sensor measurement method.

  The present invention has been made in view of the above problems, and can easily and reliably attach a magnet for a magnetic sensor to a crank mechanism in a stable state. For example, an existing mechanical metering type membrane gas meter can be magnetically mounted. It is an object to provide a magnet mounting structure and mounting method for a magnetic sensor of a crank mechanism in a membrane gas meter that can be easily changed to a sensor metering membrane gas meter.

  In order to solve the above problems, the present invention comprises the following means.

[1] A crank mechanism in which a metal upper crankpin is attached to an upper crank arm, a magnet base attached to the upper crankpin, and a magnet for a magnetic sensor attached to the magnet base, and a gas The crank mechanism of the membrane gas meter is configured to measure the gas flow rate by detecting the rotational speed of the rotating magnet through a magnetic sensor as the crank mechanism, the magnet pedestal, and the magnet rotate as the gas enters and exits. In the magnet mounting structure for magnetic sensors,
A metal metal plate portion and a synthetic resin resin plate portion are provided on the magnet base,
Attached in a state where the upper crankpin is inserted into a pin attachment hole formed in the metal plate portion,
A magnet mounting structure for a magnetic sensor of a crank mechanism in a membrane gas meter, wherein the magnet is mounted on the resin plate portion through a magnet mounting means.

  [2] The above-mentioned item [1], wherein an elastic hook is formed on a peripheral edge of the attachment portion of the magnet in the resin plate portion of the magnet pedestal, and the magnet is attached to the resin plate portion via the elastic hook by a snap fit. Magnet mounting structure for magnetic sensor of crank mechanism in membrane gas meter.

  [3] The magnet mounting structure for the magnetic sensor of the crank mechanism in the membrane gas meter according to the above item 2, wherein the elastic hook is formed integrally with the resin plate portion.

  [4] The crank base in the membrane gas meter according to any one of the items 1 to 3, wherein the magnet base is configured by an insert molded product in which the metal plate portion and the resin plate portion are integrated. Magnet mounting structure for magnetic sensor.

  [5] In any one of the preceding items 1 to 4, wherein only the peripheral portion of the pin mounting hole in the magnet base is configured by the metal plate portion, and all the remaining portions are configured by the resin plate portion. Mounting structure for the magnetic sensor of the crank mechanism in the membrane type gas meter.

  [6] The membrane type according to any one of the preceding items 1 to 4, wherein only the magnet peripheral edge portion of the magnet pedestal is constituted by the resin plate portion, and all the remaining portions are constituted by the metal plate portion. Magnet mounting structure for a magnetic sensor of a crank mechanism in a gas meter.

  [7] The crank mechanism includes a crankshaft, a lower crankarm attached to the upper end of the crankshaft, and a lower crankpin attached to the upper surface of the lower crankarm, 7. A magnet mounting structure for a magnetic sensor of a crank mechanism in a membrane gas meter according to any one of 1 to 6 above, wherein an upper crank arm is mounted.

[8] A membrane gas meter for attaching a magnet for a magnetic sensor for detecting a gas flow rate to the crank mechanism in a membrane gas meter having a crank mechanism in which a metal upper crank pin is attached to an upper crank arm. A magnet mounting method for a magnetic sensor of a crank mechanism in
Prepare a magnet pedestal having a metal metal plate portion with pin mounting holes and a synthetic resin resin plate portion,
With the caulking process with the upper crankpin inserted in the pin mounting hole of the metal plate portion in the magnet base,
A magnet mounting method for a magnetic sensor of a crank mechanism in a membrane gas meter, wherein a magnet is mounted on a resin plate portion of the magnet base via a magnet mounting means.

  According to the magnet mounting structure for the magnetic sensor of the crank mechanism in the membrane gas meter of the invention [1], the metal plate portion is formed of the metal plate portion around the pin mounting hole of the magnet pedestal. It can be securely fixed to the upper crankpin in a stable state by caulking. Further, since the magnet is attached to the resin plate portion of the magnet base, the magnet can be easily attached in a stable state via the magnet attaching means. Moreover, since the magnet can be easily and reliably attached using the existing crank mechanism, the existing mechanical metering type membrane gas meter can be easily changed to the magnetic sensor metering type membrane gas meter.

  According to the magnet mounting structure for the magnetic sensor of the crank mechanism in the membrane gas meter of the invention [2], an elastic hook is formed on the resin plate portion, and the magnet is mounted by snap fitting via the elastic hook. The magnet can be attached more easily and smoothly.

  According to the magnet mounting structure for the magnetic sensor of the crank mechanism in the membrane gas meter of the invention [3], since the elastic hook is formed integrally with the resin plate portion of the magnet base, it is not necessary to separately form the elastic hook. Accordingly, the number of manufacturing steps can be reduced, and the manufacturing can be easily performed.

  According to the magnet mounting structure for the magnetic sensor of the crank mechanism in the membrane gas meter of the invention [4] to [7], the above-described effect can be obtained more reliably.

  According to the method for attaching the magnet for the magnetic sensor of the crank mechanism in the membrane gas meter of the invention [8], similarly to the above, the magnet for the magnetic sensor can be easily and reliably attached to the crank mechanism in a stable state. Furthermore, since the magnet can be easily and reliably attached using the existing crank mechanism, the existing mechanical metering type membrane gas meter can be easily changed to a magnetic sensor metering type membrane gas meter.

FIG. 1 is a side sectional view showing a membrane gas meter to which a magnet mounting structure for a magnetic sensor of a crank mechanism according to an embodiment of the present invention is applied. FIG. 2 is a horizontal sectional view of the upper case portion of the membrane gas meter according to the embodiment. FIG. 3A is a sectional view showing the periphery of the crank mechanism in the membrane gas meter of the embodiment. FIG. 3B is an enlarged cross-sectional view showing the periphery of the upper crankpin in FIG. 3A. FIG. 4 is a perspective view showing a crank mechanism with a magnet in the membrane gas meter of the embodiment. FIG. 5 is a perspective view showing a crank mechanism in the membrane gas meter of the embodiment. FIG. 6A is a plan view showing a magnet pedestal applied to the embodiment, and FIG. 6B is a plan view showing a magnet pedestal of a first modification of the present invention. FIG. 7 is a perspective view showing a crank mechanism to which a magnet base according to a second modification of the present invention is attached. FIG. 8 is a cross-sectional view showing the periphery of a crank mechanism in a gas meter employing a magnet base according to a third modification of the present invention. FIG. 9 is a plan view showing a magnet base of a third modification. FIG. 10 is a cross-sectional view showing the periphery of a crank mechanism in a conventional mechanical metering membrane gas meter.

  FIG. 1 is a side sectional view showing a smart meter as a membrane gas meter to which a magnet mounting structure for a magnetic sensor of a crank mechanism according to an embodiment of the present invention is applied, and FIG. 2 is a horizontal sectional view of an upper case portion in the gas meter. is there.

  As shown in both drawings, the casing 1 in the gas meter of the present embodiment includes an upper case 2 constituting the upper side of the casing 1 and a lower case 3 constituting the lower side of the casing 1.

  A measurement chamber 31 is provided in the lower case 3, and a measurement film 32 that reciprocates in the front-rear direction when gas enters and exits is disposed in the measurement chamber 31. Further, a blade shaft 33 that rotates alternately in one direction and the other direction within a certain angle range by a back-and-forth movement of the measurement film 32 is disposed in the measuring chamber 31, and the upper end of the blade shaft 33 is the upper case 2. Is placed inside.

  One end of the large elbow 21 is fixed to the upper end of the blade shaft 33, and one end of the small elbow 22 is rotatably connected to the other end of the large elbow 21. The other end of the small elbow 22 is connected to a crank mechanism 4 which will be described in detail later.

  An entrance / exit 35 leading to the measuring chamber 31 is formed at the end of the partition wall between the upper and lower cases 2 and 3. An opening / closing valve 36 is provided at the entrance / exit 35 so as to be freely opened and closed.

  3A is a sectional view showing the periphery of the crank mechanism in the gas meter, FIG. 4 is a perspective view showing the crank mechanism 4 with a magnet, and FIG. 5 is a perspective view showing the crank mechanism 4.

  As shown in FIGS. 1 to 5, the crank mechanism 4 includes a crankshaft 41, a lower crank arm 42, a lower crank pin 43, an upper crank arm 44, and an upper crank pin 45. These component parts 41-45 are each comprised by metal parts.

  The crankshaft 41 is rotatably attached to a partition wall between the upper and lower cases 1 and 2 through a bearing case 40 in a vertical state.

  The upper end of the crankshaft 41 is disposed through one end of the lower crank arm 42, and the crankshaft 41 is crimped (plastically deformed) in this state, whereby the lower crank arm 42 is fixed to the upper end of the crankshaft 41. ing.

  The lower crank pin 43 is fixed to the other end of the lower crank arm 42 by inserting the lower end of the lower crank pin 43 through the other end of the lower crank arm 42 and caulking the lower crank pin 43 in this state. ing.

  The upper end of the lower crankpin 43 is inserted into one end of the upper crank arm 44, and the lower crankpin 43 is crimped in this state, whereby the upper crank arm 44 is fixed to the upper end of the lower crankpin 43. .

  As shown in FIG. 3B, the upper crankpin 45 includes a small-diameter lower end connecting portion 46 provided at the lower end, a large-diameter placing portion 47 provided above the lower end connecting portion 46, A medium-diameter elbow coupling portion 48 provided on the upper side and a small-diameter upper end coupling portion 49 provided on the upper side of the small elbow metal coupling portion 48 are provided. The mounting portion 47 has the largest diameter, and the elbow metal connecting portion 48 is smaller in diameter than the mounting portion 47 and larger than the diameters of the lower end connecting portion 46 and the upper end connecting portion 49. Further, the lower end connecting portion 46 and the upper end connecting portion 49 are formed so that their radial dimensions are substantially equal.

  The mounting portion 47 of the upper crank pin 45 is mounted on the upper surface of the other end of the upper crank arm 44, and the lower end connecting portion 46 is disposed through the other end of the upper crank arm 44. In this state, the lower end connecting portion The upper crank pin 45 is fixed to the other end of the upper crank arm 44 by crimping 46.

  As shown in FIGS. 2 and 3A, the other end of the small elbow 22 is rotatably connected to the upper crankpin 45.

  Further, one end of the bubble lever 25 is rotatably connected to the lower crank pin 43, and the other end of the bubble lever 25 is rotatably connected to the opening / closing bubble 36.

  In this configuration, as described above, when the blade shaft 33 is alternately rotated in one direction and the other direction by the reciprocating motion of the measuring film 32, the large elbow metal 21 and the small elbow metal 22 are swung while rotating at both ends. By moving, the crank mechanism 4 rotates about its crankshaft 41 as a fulcrum.

  When the crank mechanism 4 further rotates, the bubble lever 25 swings while rotating with both ends as fulcrums, whereby the opening / closing valve 36 is operated to open and close the inlet / outlet 35, and gas passes through the inlet / outlet 35 at a predetermined timing. It enters and exits the inside of the measurement chamber 31.

  As shown in FIGS. 3A, 4, and 6 (a), a rectangular plate-shaped magnet base (magnet mounting plate) 5 is attached to the upper crankpin 45 of the crank mechanism 4. In the magnet base 5, the periphery of the connecting portion with respect to the upper crankpin 45 is constituted by the metal plate portion 51, and the remaining area is constituted by the resin plate portion 55. The metal plate portion 51 is made of a metal such as brass, and the resin plate portion 55 is made of a hard synthetic resin molded body such as polyacetal (POM). The metal plate portion 51 is formed in a ring shape, and the ring hole is configured as a pin mounting hole 52. In FIG. 6A, in order to facilitate understanding of the invention, the metal plate portion 51 is cross-hatched (the same applies to FIGS. 6B and 9 below).

  A magnet mounting portion 56 is provided on the upper surface (front surface) of the resin plate portion 55 in correspondence with the magnet 50 to be mounted, and an elastic hook 57 and a positioning projection 58 are provided on the upper surface side at the periphery of the magnet mounting portion 56. It is integrally formed so as to protrude.

  In the present embodiment, the magnet base 5 is manufactured by insert molding so that the metal plate portion 51 and the resin plate portion 55 are integrated. That is, the metal plate portion 51 and the resin plate portion 55 are injected by injecting a molding material (resin) into the molding die in a state where the ring-shaped metal plate constituting the metal plate portion 51 is disposed in the molding die as an insert. The magnet pedestal 5 is integrated.

  The upper crankpin 45 in the crank mechanism 4 is inserted and disposed in the pin mounting hole 52 of the magnet base 5, and the upper stage crankpin 45 is crimped in this state, so that the magnet base 5 is fixed to the upper stage crankpin 45. Has been. In this state, the peripheral edge portion of the pin mounting hole 52 in the magnet pedestal 5 is placed on the upper end of the elbow metal coupling portion 48 of the upper crankpin 45, so that there is a gap between the magnet pedestal 5 and the small elbow metal 22. Is formed so that the rotation of the small elbow 22 is not hindered.

  A rectangular permanent magnet 50 is attached to the magnet attachment portion 56 of the magnet base 5 via an elastic hook 57 by snap fit. That is, when the magnet 50 is opposed to the magnet mounting portion 56 and is strongly pushed into the magnet mounting portion 56 side, the magnet 50 is positioned with its outer peripheral edge being restricted by the positioning projection 58, and the elastic hook 57 is positioned at the outer peripheral edge of the magnet. Then, the elastic hook 57 returns to its original shape by its own elastic force, and the tip bent portion of the elastic hook 57 engages with the outer peripheral edge portion on the surface side of the magnet 50. In this way, the magnet 50 is attached to the magnet base 5 via the elastic hook 57.

  Thus, in this embodiment, since the magnet 50 can be attached with a snap fit by simply pressing the magnet base 5, the magnet 50 can be easily and reliably attached in a stable state.

  The magnet 50 attached to the magnet pedestal 5 is arranged corresponding to the crankshaft 41 of the crank mechanism 4, and when the crank mechanism 4 rotates as described above, the magnet 50 also rotates along with the rotation. It has become.

  In the present embodiment, the metal plate portion 51 of the magnet pedestal 5 is configured by a ring-shaped metal plate. However, in the present invention, the outer peripheral shape of the metal plate portion 51 is not particularly limited. For example, as shown in FIG. 6B, a square metal plate may be used as the metal plate portion 51.

  As shown in FIG. 1, the upper case 2 is vertically partitioned by a partition wall 26, and the magnet pedestal 5 is arranged below the partition wall 26.

  An MR sensor 6 as a magnetic sensor is disposed on the upper side of the partition wall 26 corresponding to the magnet 50. The MR sensor 6 detects the rotational motion of the magnet 50 and outputs an output signal corresponding to the amount of rotation. Further, the output signal from the MR sensor 6 is calculated by the control circuit board 27 to calculate the rotational speed of the magnet 50, that is, the gas flow rate, and is displayed on the liquid crystal display panel 28.

  The magnet mounting structure for the magnetic sensor of the crank mechanism in this embodiment is configured as described above. By using this mounting structure, an old (existing) membrane gas meter (old gas meter) called a microcomputer meter or the like is used. ) Can be changed to the latest type membrane gas meter (new gas meter) called a smart meter or the like as in this embodiment.

  That is, as shown in FIG. 10, the old gas meter transmits the rotation of the crankshaft 41 in the crank mechanism 4A to a mechanical counter (not shown) via a mechanical power transmission mechanism (not shown) including gears, a rotating shaft and the like. Therefore, the magnet for MR sensor, the magnet base for magnet attachment, etc. are not provided. The crank mechanism 4A of this embodiment is different from the crank mechanism 4A of this embodiment (new gas meter) in the crank mechanism 4 (see FIG. 3A) of the old gas meter. On the other hand, the crank mechanism 4a of the old casmeter does not exist, and the old and new models have different configurations of the upper crank pins 45 and 45a of the crank mechanisms 4 and 4a.

  Therefore, in order to change the crank mechanism 4a (see FIG. 10) of the old gas meter to the crank mechanism 4 with magnet of the new gas meter (see FIG. 3), most of the parts constituting the old crank mechanism 4a, that is, the crank The parts such as the shaft 41, the lower crank arm 42, the lower crank pin 43, and the upper crank arm 44 are used as they are, and the upper crank pin 45, the magnet pedestal 5 and the magnet 50 of the above embodiment are used as new parts. Similarly, a crank mechanism 4 with a magnet may be manufactured. And if this crank mechanism with a magnet is employ | adopted as an old type gas meter, the old type gas meter can be changed into the new type gas meter like the said embodiment.

  As described above, when the magnet mounting structure for a magnetic sensor according to the present embodiment is used, the old gas meter can be easily changed to the new gas meter simply by adding the magnet base 5 and the upper crank pin 45.

  Further, the magnet base 5 in the present embodiment is configured by the metal plate portion 51 made of brass or the like around the pin mounting hole 52 for fixing the metal upper crankpin 45 made of brass or the like. The metal plate part 51 of the magnet base 5 can be reliably fixed in a stable state by caulking.

  Further, in the magnet base 5 in the present embodiment, the magnet mounting portion 56 for mounting the magnet 5 is configured by the resin plate portion 55 made of a hard synthetic resin such as POM, and therefore, the elastic hook 57 and the like are attached to the resin plate portion 55. A magnet attachment piece can be formed reliably and the magnet 50 can be fixed reliably. In particular, in the present embodiment, since the elastic hook 57 is formed on the resin plate portion 55 and the magnet 50 is attached by snap fitting through the elastic hook 57, the magnet 50 can be easily and reliably attached with one touch. Can do.

  As described above, in the present embodiment, the magnet base 5 and the magnet 50 can be securely fixed, and it is possible to effectively prevent the occurrence of a mounting failure or the like. Therefore, the old gas meter should be reliably used as a new smart meter. Can do.

  In the present embodiment, since the elastic hook 57 is integrally formed with the resin plate portion 55 of the magnet pedestal 5, there is no need to separately form the elastic hook 57, and accordingly, the number of manufacturing steps can be reduced. Manufacture can be performed easily. However, in the present invention, the elastic hook 57 is not necessarily formed integrally with the resin plate portion 55, and may be formed separately.

  In the above embodiment, the elastic hook 57 is formed on the resin plate portion 55 of the magnet base 5 and the magnet 50 is attached by the elastic hook 57. However, in the present invention, the magnet 50 is attached to the resin plate portion 55. The magnet attaching means for attaching to is not limited to the elastic hook 57 alone. For example, as shown in FIG. 7, a cover 59 that covers the magnet 50 placed on the resin plate portion 55 of the magnet pedestal 5, and a screw 54 that fixes the magnet 50 to the resin plate portion 55 via the cover 59. The magnet mounting means may be configured as described above. In addition to these, as the magnet mounting means of the present invention, an adhesive, an adhesive, a tape, or the like may be used.

  FIG. 8 is a sectional view showing the periphery of a crank mechanism of a gas meter to which a magnet pedestal 5 which is a modification of the present invention is applied, and FIG. 9 is a plan view showing the magnet pedestal 5 of the modification. As shown in both figures, the magnet pedestal 5 is configured as a resin plate portion 55 made of a hard synthetic resin such as POM only in the periphery of the magnet mounting portion 56, and all the remaining portions are made of metal metal such as brass. The plate portion 51 is used. In this magnet base 5, a metal mold with a metal plate portion 51 and a metal plate with a hole in which a rectangular hole is formed in a portion corresponding to the resin plate portion 55 is used to cover the periphery of the rectangular hole. Thus, the metal plate portion 51 and the resin plate portion 55 are integrally formed by injection molding (insert molding). Other configurations are substantially the same as those of the magnet pedestal 5 of the embodiment shown in FIG. 3A, FIG. 6A, and the like.

  Also in the magnet pedestal 5 of this modified example, the portion where the pin mounting hole 52 is formed is configured by the metal plate portion 51 made of metal, so that the upper crankpin 45 of the crank mechanism 4 is caulked as in the above embodiment. It can be securely fixed by processing. Furthermore, the magnet 50 can be easily and reliably attached to the resin plate portion 55 via the elastic hook 57 by snap fitting.

  In the above embodiment, the metal plate portion and the resin plate portion of the magnet base are integrally formed by insert molding. However, the present invention is not limited thereto, and in the present invention, the metal plate portion and the resin plate portion May be formed by separate parts, and then the parts may be assembled to produce a magnet base.

  The magnet mounting structure for the magnetic sensor of the crank mechanism in the membrane gas meter of the present invention can be suitably employed in a gas meter called a smart meter.

4: Crank mechanism 41: Crank shaft 42: Lower crank arm 43: Lower crank pin 44: Upper crank arm 45: Upper crank pin 5: Magnet base 50: Magnet 51: Metal plate portion 52: Pin mounting hole 54: Screw (magnet Mounting means)
55: Resin plate portion 57: Elastic hook (magnet mounting means)
59: Cover (magnet mounting means)

Claims (8)

A crank mechanism in which an upper crank pin made of metal is attached to an upper crank arm, a magnet pedestal attached to the upper crank pin, and a magnet for a magnetic sensor attached to the magnet pedestal, allows gas to enter and exit. Along with the rotation of the crank mechanism, the magnet pedestal and the magnet, the rotational speed of the rotating magnet is detected via a magnetic sensor to measure the gas flow rate. In the magnet mounting structure,
A metal metal plate portion and a synthetic resin resin plate portion are provided on the magnet base,
Attached in a state where the upper crankpin is inserted into a pin attachment hole formed in the metal plate portion,
A magnet mounting structure for a magnetic sensor of a crank mechanism in a membrane gas meter, wherein the magnet is mounted on the resin plate portion through a magnet mounting means.   The membrane type according to claim 1, wherein an elastic hook is formed on a peripheral edge of the attachment portion of the magnet in the resin plate portion of the magnet base, and the magnet is attached to the resin plate portion via the elastic hook by a snap fit. Magnet mounting structure for a magnetic sensor of a crank mechanism in a gas meter.   The magnet mounting structure for a magnetic sensor of a crank mechanism in a membrane gas meter according to claim 2, wherein the elastic hook is formed integrally with the resin plate portion.   The magnetic sensor of the crank mechanism in the membrane gas meter according to any one of claims 1 to 3, wherein the magnet base is configured by an insert molded product in which the metal plate portion and the resin plate portion are integrated. Magnet mounting structure.   The film according to any one of claims 1 to 4, wherein only the peripheral portion of the pin mounting hole in the magnet pedestal is constituted by the metal plate portion, and all the remaining portions are constituted by the resin plate portion. Magnet mounting structure for a magnetic sensor of a crank mechanism in a gas type gas meter.   The membrane gas meter according to any one of claims 1 to 4, wherein only the magnet peripheral edge portion of the magnet base is constituted by the resin plate portion, and all the remaining portions are constituted by the metal plate portion. Magnet mounting structure for the magnetic sensor of the crank mechanism.   The crank mechanism includes a crank shaft, a lower crank arm attached to an upper end of the crank shaft, and a lower crank pin attached to an upper surface of the lower crank arm, and the upper crank arm is attached to an upper end of the lower crank pin. A magnet mounting structure for a magnetic sensor of a crank mechanism in a membrane gas meter according to any one of claims 1 to 6. Crank mechanism in a membrane gas meter for attaching a magnet for a magnetic sensor for detecting a gas flow rate to the crank mechanism in the membrane gas meter having a crank mechanism in which a metal upper crank pin is attached to an upper crank arm A magnet mounting method for a magnetic sensor,
Prepare a magnet pedestal having a metal plate part with a pin mounting hole and a resin plate part made of synthetic resin,
With the caulking process with the upper crankpin inserted in the pin mounting hole of the metal plate portion in the magnet base,
A magnet mounting method for a magnetic sensor of a crank mechanism in a membrane gas meter, wherein a magnet is mounted on a resin plate portion of the magnet base via a magnet mounting means.

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