JP2000018426A - Cutoff valve driving and controlling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a waste of electric power in a device for driving a cutoff valve by rotating a motor on the basis of a driving pulse, by counting the electric signals obtained in accompany with the rotation of the motor, and judging a position of the cutoff valve on the basis of the counted number to control the stop of the motor. SOLUTION: When a valve opening signal is input in a state that a cutoff valve is closed, a motor 1 is rotated in the valve opening direction. A number of induced voltage pulses is counted from a start position when the motor 1 starts its rotation, thereby the moving distance of the cutoff valve is judged, and the output of the driving pulses from a motor driving portion 3 is stopped when the movement reaches a predetermined value as an opening position of the cutoff valve. When a cutoff signal is input in a state that the cutoff valve is located on the opening position, the motor 1 is rotated in the valve closing direction. The output of the driving pulses from the motor driving portion 3 is stopped, when the cutoff valve is contacted with a valve seat, the rotation of the motor 1 is restricted and the induced voltage pulse can not be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the drive of a shut-off valve in a gas meter that drives the shut-off valve by a motor.

[0002]

2. Description of the Related Art Conventionally, in a gas meter in which a shut-off valve is driven by a motor, if there is any cut-off request,
The motor is rotated in the direction in which the valve closes to shut off.
Also, when there is a request to open the valve, the motor is rotated in the direction in which the valve opens. When the valve is closed, the motor is rotated by a drive pulse at a speed of, for example, 250 PPS for 176 steps, and when the valve is opened, the motor is rotated at a speed of 150 PPS for 54 steps, and then reversely by 250 PPS for 96 steps. I have.

If a user inputs a signal from the outside in the direction to open the valve, the drive pulse as described above is supplied to the motor to open the valve regardless of the position of the valve at present. For example, if the user inputs a signal to open the valve repeatedly twice or three times from outside, the valve is opened by the first signal.

[0004] However, when the second and third signals are received, the motor rotates in the opening direction from the valve opening position. Because of this, the open position of the valve is mechanically regulated. When a signal to close the valve is input from the restricted open position, the motor is rotated by the number of steps until the valve is surely closed, as a matter of course.

[0005]

Conventionally, because of such a configuration, even if the shut-off valve is reliably opened, a drive pulse is supplied to the motor when a signal to open the valve is input. There is a problem that wasteful power is consumed.

Accordingly, an object of the present invention is to judge how much the shutoff valve has moved from an electric signal obtained with the rotation of the motor and stop the motor when the valve has moved to an appropriate open position, and conversely. An object of the present invention is to provide a shut-off valve drive control method capable of avoiding useless power consumption by stopping a motor even when a valve is closed.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a shut-off valve drive control method for driving a shut-off valve by rotating a motor based on a drive pulse. The stop of the motor is controlled by judging the position of the valve.

The position of the shut-off valve can be determined by detecting the induced voltage pulse obtained with the rotation of the motor and counting the induced voltage pulse.

The induced voltage pulse generated by the rotation of the motor can be taken out of the plurality of coils of the motor that are not used for driving.

In order to accurately determine the position of the shut-off valve even when the load of the motor fluctuates, the width of the drive pulse is automatically adjusted in accordance with the induced voltage pulse.

After the input of the signal for opening the shut-off valve, a position where it is detected that the width of the drive pulse has sharply shortened can be determined as a position where the shut-off valve is closed.

The position of the shutoff valve can be determined by counting the number of drive pulses.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of a motor control device. The motor control device includes a motor 1, a control unit 2 including a CPU, a motor drive unit 3 controlled by the control unit 2 to supply a drive pulse to the motor 1, and an electric signal obtained as the motor 1 rotates. And a detecting unit 4 for detecting.

FIG. 2 shows an example of a mechanical configuration of the motor 1 and the shut-off valve 5. Motor 1 has two sets of coils 6 each
The shut-off valve 5 is propelled or retracted toward a valve seat (not shown) by the forward or reverse rotation of the screw shaft 8 connected to the rotor 7 to close or open the valve 5. I do.

The detecting section 4 starts from the coils that are not currently used for driving the motor 1 out of the four coils 6,
Of the induced voltage pulse generated by the rotation of. This induced voltage pulse has a motor current consumption waveform as shown in FIG. 4 corresponding to the position of the rotor 7, and the rotation of the motor 1 is detected by detecting a protrusion in the waveform as indicated by the symbol A in the figure. it can. The control unit 2 adjusts the width of the drive pulse output from the motor drive unit 3 as the protrusion of the waveform is detected by the detection unit 4.

That is, when the load of the motor 1 is light,
Since the time until the protruding portion of the waveform is detected is short, the width of the driving pulse is short. When the load of the motor 1 is heavy, the time until the protruding portion of the waveform is detected becomes long. Increase the width. In this way, energy efficiency for driving the motor 1 is good.

The control unit 2 counts the induced voltage pulses detected by the detection unit 4 as described above.
Can determine the position of the shut-off valve 5 and store the position information in a memory to stop the valve 5 at an appropriate position.

The operation will be described first with the shut-off valve 5 closed. When a valve opening signal is input while the valve 5 is closed, the motor 1 rotates in a direction to open the valve 5. However, there may be cases where the valve 5 cannot be immediately moved due to the back pressure acting on the valve 5 initially. In that case,
The control unit 2 controls the valve 5 to operate reliably by increasing the drive pulse width.

The number of induced voltage pulses (the actual number of steps of the motor 1) is counted with the start position of the motor 1 as a start position, thereby determining how much the shutoff valve 5 has moved. When the movement reaches the value determined as the opening position of the valve 5, the motor driving unit 3
The output of the drive pulse from the CPU is stopped, and the drive pulse is not output any more.

Next, a case where a shut-off signal is input when the shut-off valve 5 is at the open position will be described. When the cutoff signal is input, the motor 1 rotates in a direction to close the valve 5. When the valve 5 comes into contact with the valve seat, the valve 5 cannot move any further, so that the rotation of the motor 1 is restricted. This state can be determined by the control unit 2 because the detection unit 4 cannot detect the induced voltage pulse.
Is stopped, and in this case as well, no further drive pulse is output.

Incidentally, the rotation of the motor 1 may be restricted due to some abnormality. Therefore, it is necessary to check whether the rotation of the motor 1 is restricted because the shutoff valve 5 is closed. As one of the determinations, a method of detecting whether or not gas is flowing can be considered.

Next, an example of the operation will be described with reference to the flowchart of FIG.

The valve position information N is set in the memory of the control unit 2 in advance, and the control unit 2 monitors whether there is a signal for opening and closing the shutoff valve 5 (step S).
1). When a signal for opening the valve 5 is input, a drive signal (drive pulse) for opening the valve 5 is output from the motor drive unit 3 (step S2). The presence or absence of rotation of the motor 1 is determined based on whether the detection unit 4 detects the induced voltage pulse (step 3).

If it is not rotating, the drive pulse width is increased and the output is continued (step S4). The presence or absence of rotation of the motor 1 is determined again (step 5). If the motor 1 is rotating, the process proceeds to step 6, and if not, it is determined that there is some abnormality, and an abnormality signal is output. For example, when there is an abnormal signal,
It is conceivable that a signal for opening the shutoff valve 5 is output several times to check whether or not the operation is normal, and then notify the user of the abnormality.

In step 6, it is assumed that the motor 1 has rotated one step, and N = N + 1. Next, N = N0 (N
It is determined whether or not 0 has reached the number of steps corresponding to the open position of the shut-off valve 5) (step 7). If it has not reached N0, the process returns to step 2 and the rotation of the motor 1 is repeated. N
= N0, the output of the drive signal from the motor drive unit 3 is stopped (step S8). Therefore, the present system can know the current position of the valve 5 from the value of N.

On the other hand, when a signal for closing the shutoff valve 5 is input in step S1, a drive signal (drive pulse) for closing the valve 5 is output from the motor drive unit 3 (step S11). The presence or absence of rotation of the motor 1 is determined based on whether the detection unit 4 detects the induced voltage pulse (step 12).

If it is not rotating, the drive pulse width is increased and its output is continued (step S13).
The presence or absence of rotation of the motor 1 is determined again (step 14),
If it is rotating, the process proceeds to step 15, and if it is not rotating, it is determined that there is some abnormality, and an abnormality signal is output.

In step 15, the motor 1 is set to 1 in the reverse direction.
It is assumed that N = N-1 assuming the step rotation. Next, N
= N1 (N1 is the number of steps corresponding to the shut-off position of the shut-off valve 5) is determined (step 16). If it is not N1, the process returns to step 11, and the rotation of the motor 1 is repeated. When N = N1, the output of the drive signal from the motor drive unit 3 is stopped (step S17).

Next, the flow of the gas is confirmed from the gas flow rate information of the gas meter (step S18). If no gas is flowing, it is determined that the shut-off valve 5 is closed. If the gas is flowing, the flow returns to step S11, and the operation up to step S18 is repeated. Here, due to an abnormality, the valve 5
Even if is closed, it is conceivable that gas flows, so in that case, a warning is issued to the user by appropriate means.

Next, a method of detecting a closed position serving as a reference of the shutoff valve 5 will be described. In the process of opening the valve 5 from the closed position, the valve 5 is initially held down by the spring force of the motor 1, and both sides of the valve 5 have the atmospheric pressure and the gas pressure as shown in FIG. Differential pressure from pressure is working.

When a signal to open the shut-off valve 5 is input, the screw shaft 8 of the motor 1 rotates, but because of the deflection of the spring, the rotor 7 first moves in the direction of the valve 5 while rotating, and the spring 7 rotates. Is loose. During this time, the load on the motor 1 is still small because the valve 5 itself remains closed.

When the rotor 7 slightly moves and comes into contact with the stopper, a screw shaft 8 exerts a force for retracting the shutoff valve 5 from the valve seat. Then, the load on the motor 1 rapidly increases, and at a certain stage, the valve 5 separates from the valve seat and gas flows out. At that time, the load on the motor 1 sharply decreases. This is shown in FIG.

Since the width of the drive pulse of the motor 1 becomes longer when the load is large and becomes shorter when the load is small, it can be seen from FIG. Shorten sharply the moment you leave the seat. Therefore, a position where the drive pulse width suddenly becomes short after the increase can be determined as a position where the valve 5 is closed.

As described above, the position of the shut-off valve 5 can be accurately measured by detecting the induced voltage pulse generated by the rotation of the motor 1 and counting the induced voltage pulse. Is performed, the position information of the valve 5 can be obtained even if the drive pulse itself is counted.

[0036]

As described above, according to the first to third aspects of the present invention, it is determined from the electric signal obtained with the rotation of the motor how much the shut-off valve has moved, and the valve is appropriately opened. By stopping the motor when it has moved to the position and conversely, also stopping the motor when the valve is closed, wasteful power consumption can be avoided.

According to the fourth aspect of the present invention, the width of the drive pulse is automatically adjusted according to the induced voltage pulse, so that the position of the shut-off valve can be accurately determined even if the load of the motor changes.

According to the fifth aspect of the present invention, the position where the shutoff valve closes can be easily known without using a special sensor.

According to the present invention, wasteful power consumption can be avoided without detecting the rotation of the motor.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a motor control device for implementing a method of the present invention.

FIG. 2 is a sectional view showing an example of a mechanical configuration of a motor and a shutoff valve.

FIG. 3 is a flowchart illustrating an example of an operation;

FIG. 4 is a diagram showing an induced voltage waveform corresponding to a position of a rotor.

FIG. 5 is a diagram showing a load change of a motor due to an opening / closing operation of a valve.

[Explanation of symbols]

 1 motor 2 control unit 3 motor drive unit 4 detection unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinji Sawada 2-13-13 Nishiki, Naka-ku, Nagoya City, Aichi Prefecture Inside Ricoh Elemex Co., Ltd. (72) Inventor Kazuhisa Toyama 2-Nishiki, Naka-ku, Nagoya City, Aichi Prefecture No. 13 Ricoh Elemex Co., Ltd. (72) Inventor Hiroshi Onda 2-2-1 Nishiki, Naka-ku, Nagoya City, Aichi Prefecture Inside Rico Elemex Co., Ltd. (72) Inventor Yukihiro Kito Nishiki, Naka-ku, Nagoya City, Aichi Prefecture Ricoh Elemex Co., Ltd. (72) Inventor Shoichi Kato 2-2-13-Nishiki, Naka-ku, Nagoya-shi, Aichi F-term (reference) 3H062 AA02 AA12 BB33 CC02 DD13 FF11 HH02 HH10 3H065 AA01 CA07 5H580 AA10 BB01 BB09 FA04 FA13 FA14 FA22 FA33 FB03 FD16 HH14 HH16 HH22 HH24 JJ09

Claims (6)

[Claims] In a shut-off valve drive control method for driving a shut-off valve by rotating a motor from a drive pulse, an electric signal obtained with the rotation of the motor is counted, and the position of the shut-off valve is determined based on the number. And controlling the stop of the motor by a control method. 2. Detecting an induced voltage pulse obtained with rotation of the motor, counting the induced voltage pulse,
2. The shut-off valve drive control method according to claim 1, wherein the position of the shut-off valve is determined based on the number. 3. The shut-off valve drive control method according to claim 2, wherein an induced voltage pulse of a coil not used for driving among the plurality of coils of the motor is detected. 4. The shut-off valve drive control method according to claim 2, wherein the width of the drive pulse is automatically adjusted in accordance with the induced voltage pulse. 5. The method according to claim 1, wherein after the input of the signal for opening the shut-off valve, a position where it is detected that the width of the drive pulse is sharply shortened is determined as a position where the shut-off valve is closed. 5. The shut-off valve drive control method according to 4. 6. A shut-off valve driving control method for driving a shut-off valve by rotating a motor based on a driving pulse, wherein the number of the driving pulses is counted, and the position of the shut-off valve is determined based on the number of the driving pulses to control the stop of the motor. And a shut-off valve drive control method.