JP3356861B2 - Pressure fluctuation generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure fluctuation generator for generating a fluctuation in the pressure of a gas such as a gas in order to test the performance of a gas meter with respect to a fluctuation in a gas pressure.

[0002]

2. Description of the Related Art The pressure of a gas passing through a gas meter slightly changes depending on the state of a nearby gas meter, a gas governor, a used gas appliance, and the like. A test of the performance of a gas meter or a gas appliance with respect to such a change in gas pressure has been conventionally performed. Conventionally, in order to perform this test, an electromagnetic valve is provided in the middle of the test line, and a fluctuation in gas pressure is generated by opening and closing the electromagnetic valve.

FIG. 9 is an explanatory view showing a conventional apparatus for generating a fluctuation in gas pressure. As shown in this figure, a gas governor 53, a gas meter 54, and a flow control valve 55 are interposed in a pipe 52 for supplying gas to a gas appliance 51 in order from the gas supply source side. According to the conventional method of generating a fluctuation in gas pressure, an electromagnetic valve 56 is provided in the middle of a pipe 52 between a gas governor 53 and a gas meter 54, and the electromagnetic valve 56 is opened and closed by an electromagnetic valve driving circuit 57 to reduce the fluctuation in gas pressure. Is occurring.

[0004]

However, in the conventional method as described above, the fluctuation of the gas pressure is caused by the opening and closing of the solenoid valve 56 provided on one gas passage from the gas supply source to the gas meter 54. However, there is a problem that a delicate pressure fluctuation cannot be generated. Further, there is a problem that it is difficult to adjust the frequency of the pressure fluctuation and the pressure fluctuation width. For example, if the frequency of the pressure fluctuation is changed, the pressure fluctuation width may also change.

[0005] In the configuration shown in FIG. 9, FIG.
When the solenoid valve 56 is opened and closed as shown in FIG. 10, the gas pressure after passing the solenoid valve 56 fluctuates as shown in FIG. 10 (b), causing a sudden pressure change when the solenoid valve 56 is opened and closed, as well as overshoot and undershoot. There is a problem that a shot is generated and the test is adversely affected.

The present invention has been made in view of such a problem, and a first object of the present invention is to not only generate a slight pressure fluctuation of gas, but also adjust the frequency of pressure fluctuation and the pressure fluctuation width. An object of the present invention is to provide an easy pressure fluctuation generating device.

It is a second object of the present invention to provide a pressure fluctuation generating apparatus which can generate a gradual pressure fluctuation in addition to the above first object.

[0008]

According to a first aspect of the present invention, there is provided a pressure fluctuation generating apparatus comprising: a first pipe connected to a device for changing a pressure of a gas; a gas supply source and an upstream side of the first pipe. A second pipe and a third pipe which form two gas passages in parallel between the second pipe and the end, and are provided in the middle of the second pipe;
First pressure setting means for setting the gas pressure to a predetermined supply pressure; second pressure setting means provided in the middle of the third pipe and setting the gas pressure to a pressure higher than the supply pressure; An opening / closing unit that is provided in the middle of the third pipe and downstream of the second pressure setting unit and that opens and closes the third pipe.

In this pressure fluctuation generator, the gas passing through the second pipe is set to a predetermined supply pressure by the first pressure setting means, and flows through the first pipe. On the other hand, the gas passing through the third pipe is set to a pressure higher than the supply pressure by the second pressure setting means, and flows into the first pipe when the third pipe is opened by the opening and closing means.
When the third pipe is closed by the opening / closing means, the first pipe is closed.
Does not flow into the piping. Therefore, by opening and closing the third pipe by the opening and closing means, the pressure of the gas flowing through the first pipe fluctuates. The frequency of the pressure fluctuation is set by the opening and closing frequency of the opening / closing means, and the pressure fluctuation width is set by adjusting the difference between the pressure of the second pipe and the pressure of the third pipe.

According to a second aspect of the present invention, there is provided the pressure fluctuation generating device according to the first aspect, further provided in a third pipe between the second pressure setting means and the opening / closing means. It has a buffer tank.

In this pressure fluctuation generating device, when the third pipe is closed by the opening / closing means, gas is stored by the buffer tank.

According to a third aspect of the present invention, there is provided the pressure fluctuation generating device according to the first aspect, wherein the opening / closing means is interposed in the gas passage and the gas passage, and selectively supplies the gas according to the rotational position. It has a ball valve including a sphere having a ventilation hole to be passed therethrough, and driving means for rotating the sphere of the ball valve.

In this pressure fluctuation generating device, the third pipe is opened and closed by rotating the sphere of the ball valve by the driving means.

According to a fourth aspect of the present invention, there is provided the pressure fluctuation generating device according to the first, second or third aspect, further comprising a buffer tank provided in the middle of the first pipe.

In this pressure fluctuation generating device, the waveform of the pressure fluctuation of the gas in the first pipe is smoothed by the buffer tank.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an explanatory view showing the structure of a pressure fluctuation generator according to a first embodiment of the present invention. As shown in this figure,
The pressure fluctuation generating device of the present embodiment includes a first pipe 11 connected to a gas appliance 10. This first pipe 11
Is provided with a buffer tank 13, a gas meter 14, and a flow control valve 15 in this order from the upstream side.

The pressure fluctuation generator of the present embodiment further includes a second pipe 22 and two gas passages, which form two gas passages in parallel between the gas supply source and the upstream end of the first pipe 11. A third pipe 23 is provided. In the middle of the second pipe 22, a first gas governor 24 is provided as first gas pressure setting means for setting a gas pressure to a predetermined gas supply pressure. Further, in the middle of the third pipe 23, a second gas governor 25 as second gas pressure setting means for setting the gas pressure to a pressure higher than the gas supply pressure in order from the upstream side, and a buffer tank 26 And an electromagnetic valve 27 as an opening / closing means for opening / closing the third pipe. The solenoid valve 27 is driven by a solenoid valve drive circuit 28.

The buffer tank 26 is for storing gas when the third pipe 23 is closed by the solenoid valve 27. The buffer tank 13 is provided with the first pipe 1
This is for smoothing the waveform of the fluctuation of the gas pressure in No. 1.

Next, the operation of the pressure fluctuation generator of the present embodiment will be described. A gas (or air at the time of a test) is supplied to the second pipe 22 and the third pipe 23 from a gas supply source. The gas passing through the second pipe 22 is set to a predetermined gas supply pressure by the first gas governor 24 and flows through the first pipe 11. On the other hand, the gas passing through the third pipe 23 is set to a predetermined pressure higher than the above-described gas supply pressure by the second gas governor 25, passes through the buffer tank 26, and is supplied to the third pipe 23 by the solenoid valve 27. When the third pipe 23 is closed by the solenoid valve 27, it does not flow to the first pipe when the is opened. Therefore, the solenoid valve 27
By opening and closing the third pipe 23 by the
The pressure of the gas flowing through the pipe 11 fluctuates near the gas supply pressure. The frequency of this pressure fluctuation is set by the frequency of opening and closing of the solenoid valve 27, and the pressure fluctuation width is set by adjusting the gas pressure of the third pipe 23 by the second gas governor 25.

The third pipe 23 is controlled by the solenoid valve 27.
Is closed, the gas is temporarily stored by the buffer tank 26.

The waveform of the fluctuation of the gas pressure in the first pipe 11 is smoothed by the buffer tank 13. FIG. 2 is a characteristic diagram showing the pressure fluctuation of the gas after passing through the buffer tank 13, where H represents the pressure fluctuation width.

A test of the performance of the gas meter 14 and the gas appliance 10 with respect to the fluctuation of the gas pressure is performed using the pressure fluctuation thus generated. Further, the type of the gas appliance can be determined using the pressure fluctuation. That is, when the gas pressure is varied, the gas governor is equipped with the gas governor, and the gas governor absorbs the fluctuation of the gas pressure, so that the gas flow rate is not affected, but the gas appliance without the gas governor has the gas pressure. By utilizing the fact that the gas flow rate fluctuates due to the fluctuation, the gas pressure and the gas flow rate before and after the gas pressure fluctuation can be detected, and the presence or absence of the gas governor can be determined from the relationship between the two.

As described above, according to the present embodiment, as a method of adjusting the difference between the pressure of the second pipe 22 and the pressure of the third pipe 23, for example, by adjusting the second gas governor 25, the method is subtle. It is possible to generate a large pressure fluctuation. The frequency of the pressure fluctuation can be easily and independently adjusted by adjusting the frequency of opening and closing of the electromagnetic valve 27 by the electromagnetic valve driving circuit 28, and the pressure fluctuation width can be easily and independently adjusted by adjusting the second gas governor 25. In this embodiment,
The frequency of the pressure fluctuation is, for example, in the range of 1.5 to 15 Hz,
Pressure fluctuation width is adjustable from example 1~15mmH ₂ O.

Further, in this embodiment, since the pressure fluctuation is generated by opening and closing the solenoid valve 27, the pressure fluctuation at a relatively low frequency can also be generated. Further, in this embodiment, by providing the buffer tank 26, gas can be temporarily stored when the third pipe 23 is closed by the electromagnetic valve 27, and the gas pressure in the third pipe 23 is reduced. It can be prevented from becoming too high. Further, when the electromagnetic valve 27 is opened, a decrease in the pressure in the third pipe 23 can be prevented. Further, the provision of the buffer tank 13 can generate a smooth pressure fluctuation with a waveform.

FIG. 3 is an explanatory view showing the configuration of a pressure fluctuation generating device according to a second embodiment of the present invention. As shown in this figure,
In the pressure fluctuation generator of the present embodiment, instead of the buffer tank 26 and the solenoid valve 27, in the middle of the third pipe 23 in the pressure fluctuation generator of the first embodiment shown in FIG.
A ball valve 30 is provided. The pressure fluctuation generating device of the present embodiment further includes a motor 41 for rotating the ball of the ball valve 30, an inverter 42 for supplying a drive current to the motor 41, a power supply circuit 43 for supplying power to the inverter 42, A microcomputer 44 for controlling the operation of the inverter 42. For example, a stepping motor is used as the motor 41. In this case,
The inverter 42 generates a pulse-like drive current of a predetermined frequency under the control of the microcomputer 44 and supplies it to the stepping motor. Further, the frequency of the drive current generated by the inverter 42 can be controlled by the microcomputer 44.

FIG. 4 is a sectional view showing the structure of the ball valve 30. As shown in FIG. The ball valve 30 has a tubular gas passage 3.
1 and a ball 32 made of, for example, brass, interposed in the gas passage 31. At both ends of the gas passage 31, connection portions 31a and 31b for connecting to a pipe (the third pipe 23 in FIG. 3) are provided. Further, a ball holding portion 31c that tightly and rotatably holds the ball 32 is formed in a central portion of the gas passage 31. The ball 32 held by the ball holding portion 31c is formed with a vent hole 32a through which the gas selectively passes according to the rotational position so as to penetrate the center portion thereof. A rotating shaft 33 extending in a direction perpendicular to the axial direction of the ventilation hole 32a is coupled to the ball 32. The rotating shaft 33 penetrates the side wall of the ball holding portion 31c and protrudes to the outside. A motor 41 is connected to an end of the rotating shaft 33, and is rotated by the motor 41. In addition,
FIG. 5 shows a side view of the ball 32 viewed from the direction of the vent hole 32a, and FIG.
2 shows a plan view of FIG.

In the ball valve 30, the ball 32 is rotated by the motor 41 via the rotating shaft 33, so that the opening of the ventilation hole 32a faces the passage side and allows gas to pass therethrough as shown in FIG. And a state in which the opening of the ventilation hole 32a is in contact with the side wall of the ball holding portion 31c and gas does not pass therethrough occurs alternately.

In this embodiment using such a ball valve 30 as opening / closing means for opening / closing the third pipe 23,
Since the third pipe 23 can be opened and closed at a higher frequency than in the first embodiment, the frequency range of the pressure fluctuation can be widened. In this embodiment, the frequency of the pressure fluctuation can be adjusted, for example, in the range of 1 to 20 Hz.

A vent hole 32a formed in the ball 32 of the ball valve 30 is adapted to rotate as the ball 32 rotates.
The gas pressure after passing through the ball valve 30 changes gradually since the fully-open state is changed to the fully opened state while gradually increasing the ventilation amount, and the fully-closed state is gradually reduced from the fully opened state. Therefore, when the ball valve 30 is opened and closed as shown in FIG.
The gas pressure after passing through the upper buffer tank 13 is shown in FIG.
It changes slowly as shown in FIG. Therefore, according to the present embodiment, a sudden change in pressure, overshoot, or undershoot does not adversely affect the test.

Since the ball valve 30 opens and closes the gas passage 31 by the rotation of the ball 32, the sound when opening and closing is considerably quieter than that of the solenoid valve.

In this embodiment, the ball valve 3
Four openings may be provided on the side of the 0 ball 32 at 90-degree intervals along the rotation direction, and a cross-shaped ventilation hole 32 a communicating the four openings may be provided inside the ball 32. . In this case, the rotating shaft 33 is provided with the cross-shaped ventilation hole 3.
2a is provided in a direction orthogonal to the two central axis directions. With such a configuration, when the ball 32 is rotated at the same rotation speed as compared with the configuration shown in FIGS.
The gas passage 31 can be opened and closed at twice the frequency.

Other structures, operations and effects are the same as those of the first embodiment.

[0034]

As described above, according to the pressure fluctuation generating device according to the first aspect, the upstream end of the first pipe connected to the device that changes the pressure of the gas, the gas supply source, A second pipe and a third pipe forming two gas passages in parallel are provided therebetween, and the pressure of the gas flowing through the first pipe is changed by opening and closing the third pipe by opening and closing means. At the same time, the frequency of the pressure fluctuation is set by the opening and closing frequency of the opening and closing means, and the pressure fluctuation width is set by the difference between the pressure of the second pipe and the pressure of the third pipe. This has the effect that fluctuation can be generated, and the frequency of pressure fluctuation and the pressure fluctuation width can be easily adjusted.

According to the pressure fluctuation generating device of the second aspect, the buffer tank is provided in the middle of the third pipe between the second pressure setting means and the opening / closing means. In addition, when the third pipe is closed by the opening / closing means, gas can be stored by the buffer tank, and the pressure of the gas in the third pipe can be prevented from becoming too high. .

According to the third aspect of the present invention, as the opening / closing means, a gas passage and a ventilation hole which is interposed in the gas passage and through which gas is selectively passed according to the rotational position are formed. Since the ball valve including the sphere and the driving means for rotating the sphere of the ball are used, there is an effect that, in addition to the above-described first effect, a gently changing pressure fluctuation can be generated.

According to the pressure fluctuation generating device of the fourth aspect, since the buffer tank is provided in the middle of the first pipe, in addition to the above-described effects, it is possible to generate a pressure fluctuation having a smooth waveform. This has the effect.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a pressure fluctuation generating device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing pressure fluctuation of gas after passing through a buffer tank on a first pipe in FIG. 1;

FIG. 3 is an explanatory diagram showing a configuration of a pressure fluctuation generating device according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of a ball valve in FIG. 3;

FIG. 5 is a side view of the ball of the ball valve shown in FIG. 4;

FIG. 6 is a plan view of a ball of the ball valve shown in FIG. 4;

FIG. 7 is a plan view showing a modification of the ball of the ball valve in FIG. 3;

FIG. 8 is a characteristic diagram showing an operation of a ball valve and a pressure fluctuation of gas after passing through a buffer tank on a first pipe in the pressure fluctuation generating device according to the second embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a configuration of a conventional device that generates a change in gas pressure.

10 is a characteristic diagram showing the operation of the solenoid valve in the device shown in FIG. 9 and the pressure fluctuation of gas after passing through the solenoid valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st piping 13 Buffer tank 14 Gas meter 22 2nd piping 23 3rd piping 24 1st gas governor 25 2nd gas governor 26 Buffer tank 27 Solenoid valve 28 Solenoid valve drive circuit

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-171569 (JP, A) Patent 3148056 (JP, B2) Patent 3137511 (JP, B2) Patent 3159846 (JP, B2) Patent 3224659 (JP, B2) (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01F 25/00

Claims (4)

(57) [Claims] 1. A first pipe connected to a device for giving a change in gas pressure, between a gas supply source and an upstream end of the first pipe.
A second pipe and a third pipe forming two gas passages in parallel;
A first pressure setting means provided in the middle of the second pipe and setting the gas pressure to a predetermined gas supply pressure; and a first pressure setting means provided in the middle of the third pipe and controlling the gas pressure. A second pressure setting means for setting a pressure higher than the gas supply pressure; and a middle of the third pipe, provided downstream of the second pressure setting means, for opening and closing the third pipe. A pressure fluctuation generating device, comprising: 2. The pressure fluctuation generator according to claim 1, further comprising a buffer tank provided in the middle of the third pipe between the second pressure setting means and the opening / closing means. . 3. A ball valve including a gas passage and a sphere provided in the gas passage and having a ventilation hole through which gas is selectively passed in accordance with a rotational position;
2. A pressure fluctuation generating device according to claim 1, further comprising a driving means for rotating said sphere of said ball valve. 4. The apparatus according to claim 1, further comprising a buffer tank provided in the middle of said first pipe.
4. The pressure fluctuation generator according to 2 or 3.