JP2000292239A - Gas meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the visibility of a liquid crystal display in a gas meter for a liquefied gas, which is provided with the liquid crystal display. SOLUTION: In this gas meter, a liquid crystal display device 26 which is used to display various operating states including a gas supply stop is provided at the front of a case 19. A backlight-type illumination device 52 or an illumination lamp is provided at the rear of the liquid crystal display device 26. When it is detected by a pressure that a liquefied gas container is empty, a shutoff valve 30 is closed, and its closure is displayed on the liquid crystal display device 26. At the same time, the backlight-type illumination device 52 is turned on.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas meter provided with a liquid crystal display for displaying various operation states including a stop of gas supply on a front surface thereof.

[0002]

2. Description of the Related Art In a supply system for propane gas or the like, a gas meter is provided in a gas supply system from a liquefied gas container (cylinder) to gas equipment. The basic function of a gas meter is to measure the amount of gas used, but recently, a microcomputer is provided in the gas meter so that various control functions can be incorporated. That is, a gas pressure sensor or a gas flow rate sensor is provided in the gas meter to detect an operation state factor in the gas supply system, and an operation state of the gas supply system is grasped from signals from these sensors, and abnormal gas is detected. When it is determined that the gas is used, the shutoff valve in the gas meter is closed to forcibly stop the gas supply. Further, a reset button is provided for returning from a forced gas supply stop state, and when it is determined that the supply of gas may be restarted, the shut-off valve may be opened by operating the reset button. I can do it.

On the other hand, a liquid crystal display device is provided on the front of the gas meter, and the liquid crystal display device displays the operation state of the gas supply system by characters and icons, so that the user can grasp the operation state from the characters and icons. it can.

[0004]

Basically, the user can completely understand the operation state of the gas supply system by using characters and icons on the liquid crystal display device provided on the front of the gas meter. However, since the visibility of the liquid crystal display device is poor, when the gas meter is installed in a dark place, the display contents cannot be grasped without assistance of a flashlight or the like. When gas shutoff occurs at night, the user goes to the location of the gas meter to check the display contents and resets if possible, and performs the operation. Need to be taken. However, there is a problem that an appropriate action cannot be taken immediately because the visibility of the liquid crystal display device is poor.

[0005] The present invention has been made in view of such problems of the prior art, and has as its object to enhance the visibility of a gas meter using a liquid crystal display.

[0006]

According to the present invention, there is provided a liquid crystal display device provided in a fuel gas supply path from a liquefied fuel gas container to a gas appliance and displaying various operating states including a stop of gas supply. In a gas meter, there is provided a gas meter including a lighting device for lighting a display device, wherein the lighting device illuminates the display device when gas supply is stopped.

When the gas supply is stopped, the liquid crystal display device is illuminated by the illumination device. Therefore, when the gas meter is installed in a dark place, even if the gas supply is stopped at night, the user can grasp the display content of the liquid crystal display device and take quick response.

It is preferable that the illumination device is a backlight device provided integrally with the liquid crystal display device in order to simplify the structure. As an alternative, the lighting device can be a light emitting device that illuminates the liquid crystal display from outside.

Further, the gas meter may include a reset member provided with a light emitting means at a front end, and the light emitting means may be turned on when gas supply is stopped. By using the lighting of the liquid crystal display device and the turning on of the reset member (button) when the gas supply is stopped, it is possible to prompt the user to perform more accurate operation when the gas meter is installed in a dark place.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, a gas meter 10 includes a gas pipe 1 extending from a liquefied gas container (cylinder) 12 to a gas appliance 14 (gas range, gas bath, etc.).
6. Reference numeral 18 denotes a regulator, which is installed at the outlet of the liquefied gas container 12.

FIG. 2 shows the gas meter 10, and a case 19 of the gas meter 10 has an inlet pipe 20 at its upper surface.
And an outlet pipe 22, which is connected to the gas pipe 16 as shown in FIG.

A counter (in this case, a mechanical counter) 24 for displaying the cumulative amount of gas used is provided on the front surface of the case 19 of the gas meter 10. Counter 24
The liquid crystal display device 26 is installed on the front of the case below the case. The liquid crystal display device 26 has a gas pressure display section 26A for displaying the gas pressure graphically, and an operation state display section 2 for displaying the operating state of the gas meter by a combination of alphanumeric characters.
6B, and a display unit such as an operation pattern setting display unit 26C for setting a gas meter operation pattern in accordance with the presence or absence of an ignition and the like. In addition, in order to make it easy to understand the important operation state for the end user, Japanese is included in the display, and the display is shown as "gas stop P" in the figure. "Gas stop
The state "P" indicates a state in which the pressure of the gas supply system has dropped below, for example, 60 millimeters (water column), that is, a state in which there is no gas. That is, by seeing this display, the end user can immediately take an action such as calling a trader.

In the gas meter, the counter 24 is replaced with a mechanical one and has a digital configuration.
6, the present invention is also applicable to such an all-digital gas meter.

The gas meter has a built-in microcomputer, and the display units 26A, 26B, 26C of the liquid crystal display 26 are controlled by a program stored in a ROM of the gas meter. However, the description is omitted for the sake of brevity.

The gas meter 10 has an internal passage 28 (FIG. 3) connecting the inlet pipe 20 and the outlet pipe 22 inside the case 19, and a shutoff valve 30 is provided on the internal passage 28.
Is provided. The shut-off valve 30 is open during normal operation of the gas supply system, and can supply gas from the container 12 (FIG. 1) to the gas appliance 14. The gas meter includes a microcomputer 32. The microcomputer 32 displays the use state of the gas meter on the liquid crystal display device 26 by an electric signal from a sensor (not shown) for detecting a gas pressure and a gas flow rate.
It is determined whether or not there is an operating state in which the supply of the predetermined gas is to be automatically stopped, and if it is determined that the operating state is to stop the supply of the gas, control is performed so that the shut-off valve 30 is closed. The automatic closing of the shut-off valve 30 is performed when the liquefied gas container 12 is emptied due to the gas pressure dropping below a predetermined value, or when the liquefied gas container 12 is used in a manner that does not occur in the normal use of gas. Is the time when the problem occurs. An abnormality is detected, for example, when the gas flow rate exceeds the maximum allowable value (indicating erroneous opening of the gas stopper or disconnection of the rubber hose) or when the gas flow rate suddenly increases beyond the set value. In the case (simulating the simultaneous use of a large-sized lubricator) or when gas exceeding the set gas usage is continuously used for more than a predetermined time (for a long time use or equipment due to forgetting to turn off the gas) In the case where there is a gas leak such as incomplete closure of the gas).

The fact that the microcomputer judges that the gas supply is abnormal and the gas supply is stopped by the shut-off valve 30 simulates the way of use that does not normally occur, as an abnormality.
In addition, settings are made to allow for safety measures. Therefore,
The automatic closing of the shut-off valve 30 may be executed even if the usage is not necessarily abnormal, or there may be some abnormalities but there is no problem with the immediate use of gas. In such a case, a reset mechanism is provided on the front surface of the case 10 to enable the use of gas by opening the shutoff valve 30. The reset mechanism will be described. The reset member 34 as a return button has a stepped rod shape, and the small diameter portion at the rear end of the reset member 34 is slidably fitted in an opening 19-1 in the front wall of the case 19 in the front-rear direction. At the same time, it protrudes slightly into the internal space of the case 19. The large-diameter portion 34-1 at the front end of the reset member 34 is located in a concave portion 36 opened on the front surface of the case. Spring 3
Numeral 8 is located between the bottom surface of the concave portion 36 and a shoulder connecting the small diameter portion of the reset member 34 to the large diameter portion, whereby the reset member 34 is urged in a direction to protrude outward from the front surface of the case. . Snap ring 40 as stopper
Is provided to define the projecting position of the reset member 34. Sealing member 41 formed of an elastic material (rubber or the like)
Is provided to seal the sliding portion while allowing the reset member 34 to move when pressed for the reset operation.

A pressure-sensitive switch 42 as a sensitive member is provided at the rear end of the reset member 34 projecting into the space inside the case 19.
The pressure-sensitive switch 42 detects that a reset operation has been performed by pressing the reset member 34, and a detection signal is sent to the microcomputer.

The front end enlarged portion 34-1 of the reset member 34 located in the front end concave portion 36 of the case has a blind hole formed in the front surface thereof, and a button type LED as a light emitting unit for displaying a reset state is formed in the blind hole. Alternatively, the rear end of the lamp 43 is inserted, and is fixed integrally with the reset member 34 by appropriate means (screw or adhesive). The sealing member 41 is formed of an elastic material, and an inner peripheral portion thereof is fixed to an outer periphery of the LED or the lamp 43 by an adhesive or the like.

The circular shielding plate 44 is formed of a plastic material, and is attached to the front of the case by screws 46 so as not to fall off. However, the fitting state between the screw 46 and the shield plate 44 is loose so as to allow the shield plate 44 to freely rotate with respect to the screw 46. The screw 46 is located vertically above the recess 36. Therefore, in a normal state, the shielding plate 44 is moved by its own weight as shown in FIG.
As shown in (a), the position for shielding the reset member 34 is taken. Thus, the reset operation of the reset member 34 cannot be performed as it is. When the reset member 34 is operated for reset operation, the reset member 34 is exposed by rotating the shielding plate 44 upward as shown by the arrow in FIG. Then, the operation can be started. The shielding plate 44 is formed of a transparent material, and the reset LED is provided even in the shielding position (a).
Alternatively, the lighting of the lamp 43 can be confirmed from outside.

As described above, when it is determined by the microcomputer that an abnormality has occurred, the supply of gas is temporarily stopped, and then whether or not the abnormality is truly determined is determined. Judge and reset member 3
By operating 4, the shut-off valve 30 is opened, and the gas supply can be returned. On the other hand, if there is no gas, the gas supply is not recoverable and the gas needs to be charged. Then, an indication of gas shortage is displayed on the liquid crystal display device 26 to prompt the user to fill the gas. In FIG. 2, the display of "gas stop" represents this display. However, the gas meter is installed outdoors, and it is difficult for the liquid crystal display device 26 to be visually recognized at night or the like. Therefore, in this embodiment, the liquid crystal display device is provided with a backlight, and the backlight is normally turned off but is turned on when the shut-off valve 30 is closed, so that the liquid crystal display device can be accurately viewed even in a dark place. Is made possible.

In FIG. 3, reference numeral 50 denotes a window portion provided on the front surface of the case 19 for the liquid crystal display device 26. The liquid crystal display device 26 is fixed behind the window 50. The liquid crystal display device 26 has a well-known backlight type lighting device 52 on the back surface thereof. Liquid crystal display device 2
Similarly to 6, the lighting device 52 is controlled by the microcomputer 32 and is normally turned off, but is turned on when the shut-off valve is closed, so as to enhance visibility in a dark place.

Next, the outline of the shut-off / return operation of the shut-off valve 30 by the microcomputer 32 will be described.
FIG. 5 is a flowchart illustrating this operation.
Step 60 indicates the start of the process, and may be executed at regular intervals, for example. In step 62, a measured value of the gas flow rate detected by a gas flow rate sensor (not shown, but installed in a gas passage in the gas meter) is input, and in step 64, a pressure sensor (not shown in the gas passage in the gas meter) is inputted. Is installed), the measured value of the gas pressure detected is input. In addition, if necessary, a parameter for determining the shutoff operation and the return operation of the shutoff valve 30 can be detected.

In step 66, it is determined whether or not the shutoff valve 30 is currently in a shutoff state. If the gas supply has been performed normally until then, the shut-off valve 30 is not closed, and the determination of NO is made, and the routine proceeds to step 68, where it is determined whether or not conditions for closing the shut-off valve 30 are satisfied. Will be When the shutoff valve 30 is closed, an abnormal operation or a lack of gas is detected based on factors such as a detected gas flow rate and pressure. Shut-off valve 30
Can be closed when the gas flow exceeds the maximum allowable value (indicating incorrect opening of the gas stopper or disconnection of the rubber hose) or when the gas flow suddenly increases beyond the set value. (Simulating the simultaneous use of a large lubricator) or when gas exceeding the set gas usage is continuously used for more than the specified time (for a long time due to forgetting to turn off the gas or It mimics a gas leak such as incomplete closure). Also, when the empty state of the gas container is detected because the gas pressure is lower than the predetermined value, the shut-off valve 3
Zero closure is performed. When it is determined that the operating state is not such that the shut-off valve 30 should be closed, that is, when it is determined as NO in step 68, the process bypasses the following steps 72 to 76, proceeds to step 70, and ends this routine.

When the determination in step 68 is YES, that is, when the gas flow rate exceeds the allowable maximum value, when the gas flow rate suddenly increases beyond the set value, or when the gas flow rate exceeds the set gas usage amount, If the use has been continuously performed for more than the predetermined time, or if the gas pressure is determined to be below the allowable lower limit and it is determined that there is no gas, the process proceeds to step 72, and the shut-off valve 30
, A gas supply signal to the gas equipment 14 is stopped. Next, the routine proceeds to step 74, where a liquid crystal display is performed.
This is a display command on the screen of the liquid crystal display device 26 indicating the cause of the interruption. When the container 12 is out of gas, alphanumeric characters B and C and "gas stop P" are displayed as shown in FIG. Next, in step 76, a lighting command is sent to the backlight type lighting device 52 integrated with the liquid crystal display device 26.
In step 77, the reset LED or lamp 4 is used.
3 is lit.

If the gas is forcibly stopped due to the closing of the shut-off valve 30, in the next execution of the routine of FIG.
It is determined whether or not the reset member 34 as the return button has been pressed. This determination can be made based on the state of the switch 42. That is, the pressure-sensitive switch 42 is turned on or off depending on whether the reset member 34 is pressed.
The state changes at F. When it is determined from the state of the pressure-sensitive switch 42 that the reset member 34 has not yet been pressed, the processing of the following 82 to 86 is bypassed, and the routine exits at step 70.

If it is determined in step 78 that the reset member 34 has been pressed, the process proceeds to step 80, where the shut-off valve 3
A determination is made as to whether 0 may be released. For this determination, a determination program (the description thereof is omitted) built in the microcomputer is started, and until the determination is completed, the determination is NO, and the following processing is bypassed. Opening of the shut-off valve 30 is naturally not permitted for a gas shortage. The reset is not performed even if the reset member 34 is operated, and the liquid crystal display device 2
Numeral 6 remains the display of gas shortage, which can prompt the user to take prompt action to fill the gas.

When it is determined in step 82 that the gas supply may be returned, the process proceeds to step 82, in which the shutoff valve 30 is opened and the gas supply is restarted. In step 84, the cut-off display on the liquid crystal display device 26 is released, and in step 86, the backlight-type lighting device 52 is turned off, and the backlight is turned off. In step 87, the LED or lamp 43 is turned off.

FIG. 6 shows a modified embodiment of the illuminating device, in which an independent lamp 90 is provided on one side of the liquid crystal display device 26, and the liquid crystal display is illuminated by the lamp 90 during the shut-off operation so that the liquid crystal display can be viewed in a dark place. It is intended to enhance the character.

In the above embodiment, the lighting of the liquid crystal display device and the lighting of the reset device at the time of the gas supply cutoff operation are performed simultaneously. However, the reset device is assumed to be a normal device (a simple device without the LED or lamp 43). Rod)
It is naturally possible to turn on only the liquid crystal display device when the gas supply is cut off.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a gas supply system.

FIG. 2 is a schematic front view of a gas meter.

FIG. 3 is an overall schematic diagram of an illumination system of a reset and liquid crystal display device.

FIGS. 4A and 4B are front views of the reset member, wherein FIG. 4A shows a closed state of the shield plate, and FIG. 4B shows a state in which the shield plate is opened for reset operation.

FIG. 5 is a schematic flowchart for explaining a shutoff valve closing operation by the microcomputer.

FIG. 6 is a schematic view showing a modified example of the illumination device of the liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Gas meter 12 ... Liquefied gas container 14 ... Gas appliance 18 ... Regulator 19 ... Case 20 ... Inlet pipe 22 ... Outlet pipe 24 ... Counter 26 ... Liquid crystal display device 26A ... Gas pressure display part 26B ... Operating state display part 26C ... Operation Pattern setting display section 28 ... Gas meter internal passage 30 ... Shutoff valve 32 ... Microcomputer 34 ... Reset member 40 ... Snap ring 41 ... Sealing member 42 ... Pressure sensitive switch 43 ... Button LED or lamp 44 ... Shielding plate 50 ... Window 52 ... Backlight type lighting system

Claims (4)

[Claims] 1. A gas meter provided in a fuel gas supply path from a liquefied fuel gas container to a gas appliance and provided with a liquid crystal display device for displaying various operation states including a stop of gas supply. A gas meter comprising an illumination device, wherein the illumination device illuminates the display device when the gas supply is stopped. 2. The gas meter according to claim 1, wherein the lighting device is a backlight device provided integrally with the liquid crystal display device. 3. The gas meter according to claim 1, wherein the lighting device is a light emitting device that illuminates the liquid crystal display device from outside. 4. The gas meter according to claim 1, wherein the gas meter includes a reset member provided with a light emitting unit at a front end, and the light emitting unit is turned on when gas supply is stopped.