JP2018205129A - Film-type gas meter - Google Patents

Abstract

To provide a gas meter with a crank mechanism that is not easily broken by external impact and can manage the size of a manufactured part.SOLUTION: A crank shaft 20 with an elastic engagement nail 21 is fit into a crank shaft hole in a crank board 17, and the engagement nail 21 is moved until he nail protrudes from a crank shaft hole lower port 19b so that the engagement nail engagement part 21a is snap-fit engaged to a crank board lower end part 17b. This is how the crank is fit to the crank board 17.SELECTED DRAWING: Figure 6

Description

According to the present invention, a crank is rotated from a spindle via a hinge based on a reciprocating motion of a measuring membrane, a permanent magnet is attached to the crank, and the permanent magnet is rotated by a magnetic sensor attached at a position facing the permanent magnet. The present invention relates to a membrane gas meter that detects and outputs a flow rate signal, and more particularly to a shape of a crankshaft for attaching the crank to a crank base assembled to a gas meter body.

Conventionally, the rotational movement of the blade shaft that rotates at a fixed angle by the reciprocating movement of the measurement membrane in the lower case of the gas meter body is transmitted to the crank mechanism via the large elbow and small elbow in the upper case. In the membrane gas meter that controls the gas entering and exiting the measuring chamber by transmitting the rotational movement of the crank mechanism to the valve of the measuring chamber, the crank mechanism is a crank base receiving shaft that protrudes from the lower case side to the upper case side. The crankshaft hole and the crankshaft formed in the crank base with the upper opening and the lower end fitted together are engaged at the lower end of the crank base with a snap-fit ring system in which the convex ring and the concave ring groove are engaged. It is attached.

However, the conventional membrane gas meter described above has the following problems.

1. When the meter receives an impact from the outside, the snap fit ring method in which the concave and convex fitting is performed has a small fitting force, so that the crank mechanism can be easily detached from the crank table, resulting in malfunction and failure.

2. In the snap fit ring method with concave and convex mating, precise dimension management is required for both the ridge ring and the concave ring groove, so even if there is a difference in fine dimensions, the fitting is tight during assembly or it is easy to come off after assembly. As a result, the production of the gas meter is delayed and the productivity is lowered.
Further, if it is attempted to carry out precise dimensional management with time and effort, the manufacturing cost will increase accordingly.

JP 2006-075712 A

An object of the present invention is to provide a gas meter that employs a crank mechanism and that is less likely to fail even when subjected to an impact from the outside, and that allows easy management of the dimensions of manufactured parts.

In order to achieve the above object, according to the first aspect of the present invention, a pair of metering membranes are incorporated in a metering chamber formed in the lower case of the gas meter body, and the rotary motion of the spindle that rotates by a fixed angle by the reciprocating motion of the metering membrane Is transmitted to the crank via a large elbow and a small elbow in the upper case, and the permanent magnet is rotated by rotation of the crank and the flow rate signal is output by detecting the rotation of the permanent magnet by a magnetic sensor. In the gas meter, the upper case is partitioned into an electronic chamber and a lower stage is divided into a machine room by a partition plate, and a substantially hollow cylindrical crank base receiving shaft is projected from the lower case side into the machine room. The lower end of the crank base is fitted to the upper opening of the receiving shaft, and the crank base is assembled vertically, and the lower end of the crank shaft of the crank is provided with an elastic openable / closable engaging claw. When the crankshaft is inserted into a crankshaft hole formed in the crank base and the engaging claw moves to a position protruding from the lower opening of the crankshaft hole, the engaging claw engaging portion is moved to the crank base at that position. A snap-fit engagement with the lower end and the crank is detachably attached to the crank base. A permanent magnet that rotates coaxially with the rotation of the crankshaft of the crank mechanism is provided on the top surface of the crank mechanism. Attaching the attached permanent magnet mounting plate, providing a magnetic sensor in the electronic chamber facing the permanent magnet, detecting the rotation of the permanent magnet by the magnetic sensor, and outputting a flow rate signal. Is.

According to the present invention, by using the snap fit fitting with the engaging claw as the means for fixing the crank and the crank base, it is possible to increase the resistance to impact and prevent the gas meter from being broken.

Further, since the dimensions of the assembly parts can be easily managed, the productivity of the product can be improved.

It is a longitudinal cross-sectional view of a membrane type gas meter. It is AA 'sectional drawing. It is explanatory drawing which shows the internal structure of a membrane type gas meter. It is explanatory drawing of a crank, (a) is a front view of a crank, (b) is a side view of a crank, (c) is a top view of a crank. It is explanatory drawing of a crank base, (a) is a front view of a crank base, (b) is a side view of a crank base, (c) is a top view of a crank base. (A) is explanatory drawing which shows the state which attached the crankshaft to the crank base. (B) is an enlarged view of a portion where the crankshaft is snap-fit engaged with the crank base. It is explanatory drawing which shows the state which attached the crank base and the crank to the crank base receiving shaft.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the drawings, reference numeral 1 denotes a gas meter main body, 3 denotes a measuring chamber formed in a lower case 2 of the gas meter main body 1, and two measuring films 4 in the measuring chamber 3 reciprocate by gas pressure. Thus, the gas flow rate is measured.

Reference numeral 6 denotes a spindle which is mounted in a longitudinal direction for rotating the reciprocating motion of the measuring membrane 4 through a lever 5 by a predetermined angle. The spindle 6 is moved from the measuring chamber 3 to the machine chamber 7 at its upper end 6a. And the reciprocating motion of the metering membrane 4 is transmitted to the projecting portion via the large elbow 8 and the small elbow 9 to the crank 10 to convert the crank 10 into a rotational motion.

The rotational movement of the crank 10 is transmitted to the valves 11 and 12 by the valve drive lever 25 to open and close the valves 11 and 12, and the gas entering the measuring chamber 3 and the metered gas outlet 27 are discharged from the gas inlet 26. Control the gas.

The upper case 13 is partitioned into an electronic chamber 14, a machine chamber 7, and a distribution chamber 15 by a partition plate. A substantially hollow cylindrical crank base receiving shaft 16 projects from the lower case 2 side into the machine chamber 7. The lower end 17a of the crank base 17 is fitted into the upper opening 16a of the crank base receiving shaft 16, and the crank base 17 is fixed to the upper surface 15a of the distribution chamber 15 with screws 18.

A crankshaft hole 19 is formed in the crank base 17, and a crankshaft 20 provided with an openable / closable engagement claw 21 having elasticity from the upper opening 19 a to the lower end of the crankshaft hole 19. When the engagement portion 21a of the engagement claw 21 moves to a position protruding from the lower opening 19b of the crankshaft hole 19, the engagement that has been bent radially inward of the crankshaft 20 within the crankshaft hole 19 is inserted. The joint claw 21 bends outward in the radial direction of the crankshaft 20, and the engagement portion 21a of the engagement claw 21 is detachably snap-fit engaged with the lower end portion 17b of the crank base 17 at this position.

The snap fit by the engaging claw 21 has a large area where the engaging portion 21a is in contact with the lower end portion 17b of the crank base 17 and the crankshaft 20 unless the engaging claw 21 is bent inward in the radial direction of the crankshaft 20. Does not move in the axial direction, and therefore, a sufficient resistance against the pulling force in the upward direction is particularly ensured.

The present invention can prevent the crank from being detached from the crank table even when the gas meter receives an impact from the outside due to this resistance force.

The shape of the engaging claw is not limited to two, and may be three or more.

As shown in FIG. 4, the crank 10 includes a lower crank plate 10a, a pin 10b, a middle crank plate 10c, an elbow engaging pin 10d, and a permanent magnet mounting plate 10e attached to the crankshaft 20. By rotating the spindle 6 which is rotated by the reciprocating motion 4, the spindle 6 rotates about the crankshaft 20 via the large elbow 8 and the small elbow 9.

The permanent magnet mounting plate 9e is provided with a claw piece 23 for fixing the permanent magnet 22, and the permanent magnet 22 is fixed to the permanent magnet mounting plate 10e by fixing the two sides with the claw piece 23. The permanent magnet 22 is positioned on the vertical line of the crankshaft 20 and is set to rotate in accordance with the rotation of the crank 10 around the vertical line.

A magnetic sensor 24 that outputs a flow rate pulse signal and a power source 28 are installed in the electronic chamber 14 at a position facing the permanent magnet 22. When the permanent magnet 23 rotates, the magnetic sensor 24 detects this rotational movement. Then, a flow rate signal is output, and a flow rate calculation circuit (not shown) is driven to measure the gas flow rate.

1 Gas meter body 2 Lower case 3 Measuring chamber 4 Measuring membrane 5 Lever 6 Spindle 7 Machine room 8 Large elbow 9 Small elbow 10 Crank 10a Lower crank plate 10b Pin 10c Middle crank plate 10d Elbow engaging pin 10e Permanent magnet mounting plate 11 Valve 12 Valve 13 Upper case 14 Electronic chamber 15 Distribution chamber 16 Crank base receiving shaft 16a Crank base receiving shaft upper port 17 Crank base 17a Crank base lower end portion 17b Crank base lower end portion 18 Screw 19 Crank shaft hole 19a Crank shaft hole upper port 19b Crankshaft hole lower opening 20 Crankshaft 21 Engaging claw 21a Engaging claw engaging portion 22 Permanent magnet 23 Claw piece 24 Magnetic sensor 25 Valve drive lever 26 Gas inlet 27 Metered gas outlet 28 Power supply

Claims (1)

A pair of measuring membranes are installed in the measuring chamber formed in the lower case of the main body of the gas meter. In the membrane gas meter that transmits to the crank, rotates the permanent magnet by the rotation of the crank and detects the rotation of the permanent magnet by a magnetic sensor and outputs a flow rate signal,
The upper case is partitioned into an electronic chamber and a lower stage into a machine room by a partition plate, and a substantially hollow cylindrical crank base receiving shaft projects from the lower case side into the machine chamber. Fitting the lower end of the crank base to the upper opening and assembling the crank base vertically,
An elastic openable / closable engaging claw is provided at the lower end of the crankshaft of the crank, and the crankshaft is fitted into a crankshaft hole formed in the crank table so that the engaging claw is in the crankshaft hole. When moving to the position protruding from the lower mouth, the engaging portion of the engaging claw snap-engaged with the lower end of the crank base at that position, and the crank was detachably attached to the crank base,
At the uppermost stage of the crank mechanism, a permanent magnet mounting plate having a permanent magnet mounted on the upper surface rotating coaxially with the rotation of the crank shaft of the crank mechanism is attached.
Providing a magnetic sensor in the electronic chamber facing the permanent magnet, and detecting a rotation of the permanent magnet by the magnetic sensor and outputting a flow rate signal;
A membrane gas meter.

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