JPS634645B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas meter with a shutoff mechanism that has a mechanism that shuts off gas when the gas flow rate deviates from a specified range or in an emergency.

For indoor gas piping, in the event of an earthquake, power outage, leak of unburned gas, or other emergencies, or when the gas flow rate is outside the specified range,
For safety reasons, an automatic gas shutoff device that automatically shuts off the gas has been proposed. As a means of this,
Generally, a solenoid valve is installed in the gas pipe near the gas meter, and the solenoid valve is activated by a cutoff signal from a gas leak detector, earthquake sensor, or gas usage status monitor. A method has also been proposed in which a shutoff valve is incorporated and operated by a shutoff signal. In the former case, solenoid valves are expensive, and it takes a lot of work to install them in the piping, especially in the case of existing piping, where there may be problems in installing them, and in the latter case, the installation of complicated gas meters is difficult. This method has disadvantages such as the need to further incorporate a shutoff valve device into the mechanism, making it more complicated, and the gas meter becoming larger.

In view of the above, the present invention provides a locking mechanism for blocking reciprocating or rotational movement by a cutoff signal and a double-return mechanism for releasing the locking mechanism in the gas meter, thereby simplifying the cutoff mechanism and, in particular, the return operation. The purpose of the present invention is to provide a mechanism that smooths out the return operation by eliminating the pressure difference between the measuring membranes of the gas meter and eliminating the impact movement during double return and reducing the return operation force.

The details of the present invention will be explained below based on Examples.

In Figures 1 and 2, 1 is the main body, 2 is a measuring membrane made of a rubber diaphragm etc. built into the measuring chamber 3 in the main body, and the measuring membrane 2 is the front and back of the measuring chamber 3 in Figure 2. The pressure difference of the gas entering the metering chamber 3 causes it to move back and forth, and this movement causes the blade shaft 5 to rotate back and forth through the movable blade 4, causing the large armrest 6 formed integrally with it to rotate. It is transmitted as a vibration. There is another metering chamber at the rear of the main body 1 in FIG. The rotational oscillation of is small elbow metal 7,
Each rotational direction is oscillated at a constant angle so that the rotational movement of the crank arm 8 is transmitted through the crankshaft 7'. The rotation of the crank arm 8 similarly becomes a rotational movement of the crank arm 8' about the axis 9, and the rotation of the shaft 9 is decelerated on one side through the worm gear box 10 and becomes the rotation of the metering transmission shaft 11, which is transmitted to the metering mechanism. A slide valve 1 controls the opening and closing of the gas that is transmitted and flows into and out of the metering chambers 3 and 3' (on the back side, not shown) via the connecting plates 13 and 13' by rotating the crankshaft 12 on the other hand.
4 and 14' are pivoted about shafts 15 and 15', 16 and 16' are the valve ports thereof, and 17 is the outlet of the gas body. That is, the membrane motion of the metering membrane is converted into rotational motion, and the rotational motion is transmitted to the metering mechanism and the slide valve section, which are integrally formed in the main body 1. Reference numeral 18 indicates the upper part of the main body 1, which serves as a case for the rotating mechanism section, etc., and the gas inlet 1.
9. A gas outlet 20 is provided, and a metering unit case 21 in which a metering mechanism is housed is integrally formed.

Next, 22 is a locking lever of a locking mechanism, one end is a locking part 23 that can stop the rotation of the crank arm 8', the other end is integrally provided with a permanent magnet 24, and the iron core of the electromagnet 25 is normally installed. It has a drive section 27 that is attracted to the drive section 26, and swings around the metering transmission shaft 11. Note that the electromagnet 25 is fixed to the upper body 18.
Reference numeral 28 denotes an operating shaft of a return mechanism that releases the state in which rotation of the crank arm 8' is blocked by the locking lever, and a return cam 2 that returns the locking lever 22.
9. It has a valve operating cam 31 that operates a valve opening lever 30 that opens a slide valve 14, which will be described later. 32 is the operating lever, and clockwise rotation in the figure is the return operating direction, and the operating shaft is not shown. It is always biased in the counterclockwise direction by a spring and locked by a stopper. 33 is the slide valve 14
The valve opening part of the valve opening lever 30 can open the valve opening by lifting the slide valve via a pin 34 provided on the side of the valve opening lever 30. The valve opening lever 30 is normally rotated clockwise by its own weight around the metering transmission shaft 11. The other end is locked with the valve operating cam 31 by its driving part 35.
It is in contact with the lower side of.

The present invention has the above configuration, and the operation will be explained below.
Figures 1 and 2, and enlarged figures 3 and 4 of the main parts.
This will be explained using figures. Under normal conditions, the gas flow enters the upper body 18 through the inlet 19 and passes through the valve ports 16 and 16'.
After entering the respective metering chambers 3 and 3', the metering membranes 2 and 2' (on the back side, not shown) move back and forth due to the pressure difference between the inlet pressure and the outlet 17, and the gas that has once entered the metering chambers is pushed out to the main body outlet 17 through the valve ports 16, 16' and the passages (not shown) formed on the valve sides of the slide valves 14, 14', and then to the outlet 20.
The gas is supplied to the indoor gas supply port. On the other hand, the movement of the metering membrane is as follows: wing shafts 5, 5', large elbows 6, 6', small elbows 7,
7' into rotational movement of the crank arm 8. One side of this rotation is transmitted to the metering mechanism through the shaft 9, the worm gear, and the metering transmission shaft 11, and the amount of gas used is displayed, and the other side is when the crankshaft 12 rotates around the shaft 9, and the connecting plates 13, 1
3', the slide valves 14, 14' are swung, and the valve ports 16, 16' slide open and close to move in and out of the gas metering chambers 3, 3', thereby continuing the operation. At this time, the electromagnet 25 and the non-energized 26 are simply iron cores, the permanent magnet 24 of the locking lever 22 is attracted to the iron core, and the locking portion 23 is attached to the crank arm 8'.
The crank arm 8' can rotate freely outside the rotation range of the crank arm 8'. That is, it is in the state shown by the solid line in FIG. Further, the valve opening lever 30 is locked in the clockwise rotation direction due to the balance of its own weight, and its valve opening 33 is also in a state separated from the pin 34, so that the operation of the slide valve is not hindered.

Next, when there is an abnormality, for example when the gas flow rate deviates from the specified range (detected by a sensor or microcomputer not shown), or in an emergency using a gas leak detector or earthquake sensor, it is necessary to shut off the gas. , a one-shot current flows through the electromagnet 25, a repulsive magnetic field of the permanent magnet 24 is generated in the magnetic circuit constituted by the iron core 26, the driving part 27 is instantly separated from the iron core 26, and the dead weight of the locking lever 22 in the driving part direction is The locking portion 23 rotates counterclockwise around the metering transmission shaft 11 and is locked at a position in the direction of the small diameter of the return cam 29. At this time, the locking portion 23 rotates counterclockwise and protrudes into the rotation range of the crank arm 8', and finally the crank arm 8' is rotated. This will stop the rotation of arm 8'. The dashed line in FIG. 4 shows this state. By stopping the crank arm 8', the operation of the cranks 13, 13' and the slide valves 14, 14' is stopped, the gas supply to each metering chamber is stopped, the operation of the metering membrane is also stopped, and the gas supply is stopped to the slide valve 14. , 14' and the valve ports 16, 16' to ensure safety. When safety is ensured and the return is to be made, the return cam 29 is also rotated clockwise by a half-turn to the right of the operating lever 32, pushing up the drive portion 27 of the locking lever 22, and the permanent magnet 24 is attracted to the iron core 26 again, causing the locking to take place. The stop part 23 escapes from the rotation range of the crank arm 8', and the stop part 23 escapes from the rotation range of the crank arm 8'.
3 and the crank arm 8' are released, the crank arm 8' becomes free to rotate, and the operation begins and the gas flow is resumed. At this time, that is, when returning the locking lever 22, A considerable force is required to overcome the locking force of the crank arm 8' acting on the stop portion 23 and release the engagement. The force that acts on the locking part is originally the force that stops the metering membrane, and the metering membrane is determined by the pressure difference between the gas inlet pressure and outlet pressure (almost zero) and the area of the membrane, and in the end, a force of several kilograms is applied to the metering membrane. It means that they are joining. In order to release the lock against this locking force, excessive force is required, and immediately after the lock is released, the operation is restarted with an impact movement.

Therefore, the characteristic operation of the present invention will be explained. First, in the rotation range of 0 to 90 degrees when the operating lever 32 is rotated, the large diameter direction of the return cam 29 is downward before the operation, and becomes horizontal to the left when rotated 90 degrees, so the locking lever 22 It has no relation to the return operation. The 90° rotation state is shown by the dashed line in Figure 4. On the other hand, the valve operating cam 31 related to the pressure relief device is in the state shown by the solid line in FIG.
The valve opening lever 30 rotates counterclockwise around the metering transmission shaft 11, and pushes up the pin 34 with the valve opening 33 at the other end of the slide valve 14.
is lifted from the valve seat of the valve port 16 to open the valve. When the valve is opened, the gas inlet pressure acts on the passage leading to the main body outlet 17, and the mutual chambers separated by the metering chamber metering membrane communicate with the main body outlet, and the other metering chamber also communicates with the outlet side. , the differential pressure across the other metering membrane disappears, and therefore the locking force of the crank arm 8' on the locking portion 23 no longer acts, and on the contrary, a slight reverse rotational force is generated. This state is shown by the dashed line in FIG. 3, and from this state, by rotating the operating lever 32 from 90° to 180°,
The valve operating cam 31 continues to act on the valve opening lever 30, and the slide valve continues to remain open.The return cam 29 rotates the locking lever 22 clockwise with a slight force, and the locking portion 23 rotates the crank arm 8'. The permanent magnet 24 escapes from the rotation range and easily returns to the state shown by the solid line in FIG.
2 is held in a manner that does not interfere with the operation of the meter, the crank arm 8' begins to rotate, and the operating lever 3
2 is returned to its original state by the reversal spring, and both cams are likewise returned to their pre-operation state.At the same time, the valve opening lever 30 is rotated clockwise, and the slide valve returns to its normal position, continuing normal operation. It turns out. As described above, in this embodiment, the valve opening lever 30 is added to the locking lever mechanism, and this is combined with a simple cam mechanism to open the slide valve. This is a simple and reliable method, and the return operation can be performed extremely smoothly. It is something that

As described above, the present invention provides a gas meter with a shut-off mechanism that can reliably shut off gas using a simple means in the event of an abnormality, and that can be easily reset after safety has been confirmed. It has the following effects.

1. Without changing the original structure of the gas meter, the shutoff/return mechanism is installed inside the meter using simple means, so there is no fear of failure and high reliability. Furthermore, during the return operation, which is a feature of the present invention, the force applied to the locking part is removed by an extremely simple means that eliminates the pressure difference acting on the metering membrane, and the return operation can be performed easily and smoothly. There is no return operation, and it has excellent safety, durability, and reliability.

2 Regarding the locking mechanism, the purpose can be achieved with a simple locking lever, and it provides a shutoff mechanism with reliable operation and simple structure.In addition, an external solenoid valve can be installed as an emergency shutoff device. It is also easy to install on existing piping.

3. Also, during the return operation, the pressure difference in the metering membrane of the gas meter can be quickly eliminated by slightly lifting the valve body of the slide valve part, and smooth return without impact movement can be achieved quickly with a small operating force.

Furthermore, no valve structure other than the slide valve part is required, and the structure is extremely simple.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of a gas meter with a shutoff mechanism of the present invention, FIG. 2 is a partial front view of the same gas meter, and FIG. 3 is a return mechanism section as viewed from the line A-A' in FIG. An enlarged view of Figure 4 is B- of Figure 1.
FIG. 3 is an enlarged view of the locking mechanism section as viewed from the arrow B'. 2...Metric membrane, 5...Blade shaft, 6, 6'...Large armrest, 7,7'...Small armrest, 8,8'...Crank arm, 11...Metric transmission shaft, 12... ...Crankshaft, 13,13'...Connecting plate, 14,14'...Slide valve, 16,16'...Valve port, 22...
Lock lever, 24...Permanent magnet, 25...Electromagnet, 26...Iron core, 28...Operation shaft, 29...Return cam, 30...Valve opening lever, 31...Valve operation cam, 32...Operation Lever, 34...pin.

Claims (1)

[Claims] 1. A mechanism that converts the membrane motion of a metering membrane that reciprocates due to a pressure difference into a rotational motion, a transmission mechanism that transmits the rotational motion to a metering mechanism and a slide valve section that opens and closes a valve port of a gas passage, and the transmission mechanism. A locking mechanism that abuts to block the flow of gas, a means for lifting the slide valve portion that seals the valve port so as to eliminate the pressure difference in the metering membrane upon return, and locking of the locking mechanism. A gas meter with a shutoff mechanism, which is equipped with a return mechanism having means for releasing the .