JP2000097360A - Passage cut-off device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a passage cut-off device constituted such that even when an opening signal is continuously generated, a distance by which a valve element is moved in an opening direction from a closed position is not increased to a value longer than a normal movement distance in an ordinary opening direction and in subsequent closing operation, the valve element is brought into a reliable contact with a valve seat to thereby eliminate generation of fluid leakage. SOLUTION: A drive circuit 1 is provided with a deciding part 7 to decide whether an opening signal is continuously inputted, and a control part 2 to control a stepping motor 4 so that opening operation is effected consequently to closing operation in a case of the deciding result being a continuous input. Or, a stopper is protruded from the valve element, and by bringing the stopper into contact with the base plate of the stepping motor, movement in the opening direction of the valve element by a distance exceeding a given value is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow path shut-off device for a gas meter, a water meter, or the like, which opens and closes a valve by a stepping motor.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing the configuration of a conventional flow path blocking device. A conventional valve opening / closing control operation will be described with reference to FIG. The control unit 2 of the drive circuit 1 receives an open signal and a close signal input from the outside, generates a pre-programmed motor drive sequence signal,
Output to the drive unit 3 in the drive circuit 1. The drive unit 3 receives the motor drive sequence signal and supplies power to the stepping motor 4. The stepping motor 4 rotates according to the motor drive sequence signal to move the valve element 5. The valve element 5 converts the rotational motion of the stepping motor 4 into a linear motion by a rotary motion / linear motion converter, and opens and closes the flow path.

[0003]

However, in the conventional flow path blocking device, when there is a continuous open signal from the outside, the valve element 5 is connected to the valve seat 6 as shown in FIG. Since the distance L moving in the opening direction from the contacted closing position is longer than the moving distance M in the normal opening direction as shown in FIG. The valve body 5 does not reach the position where it comes into contact with the valve seat 6, and a gap N is formed between the valve body 5 and the valve seat 6 in the subsequent closing operation as shown in FIG. There was a problem.

[0004] It is an object of the present invention that, even when there is a continuous open signal, the distance that the valve element moves in the opening direction from the closed position is not longer than the normal moving distance in the opening direction. An object of the present invention is to provide a flow path shut-off device in which a valve body surely comes into contact with a valve seat by a closing operation and does not cause fluid leakage.

[0005]

SUMMARY OF THE INVENTION The present invention has a valve element for opening and closing a flow path, a stepping motor for driving the valve element, and a drive circuit for controlling the stepping motor in response to an open signal and a close signal. In the flow path blocking device, the first mode achieves the above object by an electrical configuration, and the second mode achieves the above-mentioned object by a mechanical configuration.

That is, in the first mode, the driving circuit 1
Judgment unit 7 for judging whether or not the open signal has been continuously input
And a control unit 2 that controls the stepping motor 4 so as to perform the closing operation and then perform the opening operation when the determination result is a continuous input.

In the second embodiment, when the stepping motor 4 is driven by an open signal to move the valve body 5 from the closed position to a certain distance in the opening direction, further movement is restricted to cause the stepping motor 4 to step out. It is characterized by having a stopper 16. In this case, if the stopper 16 is protruded from the valve body 5 and the stopper 16 contacts the base plate 11 of the stepping motor 4, the movement of the valve body 5 in the opening direction by a predetermined amount or more is restricted. This can be dealt with simply by providing a stopper 16 on the valve body 5.

[0008]

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

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In this flow path cutoff device, a determination unit 7 for determining whether an open signal from the outside is continuously input is added to the drive circuit 1, and a control unit 2 of the drive circuit 1 is provided.
Is different from the related art in that when the determination result of the determination unit 7 is a continuous input, the stepping motor 4 is controlled by the drive unit 3 so as to perform the opening operation after performing the closing operation.

The control operation will be described with reference to the flowchart of FIG. When a signal is input to the drive circuit 1 from the outside, the motor drive sequence is divided depending on whether it is an open signal (step S1) or a close signal (step S2). A closing operation is performed (Step S3).

When the open signal is received, the determination section 7 of the drive circuit 1 determines that the operation is continuous if the previous operation is the open operation or if the previously input signal is the open signal (Y in step S4).
ES), and outputs a continuous open signal to the control unit 2. Conversely, if the previous operation is the closing operation, or if the previously input signal is the closing signal, it is determined that the operation is discontinuous (NO in step S4), and the discontinuous open signal is output.

When the controller 2 receives the continuous open signal, it outputs a motor drive sequence signal for closing the valve and then outputs a motor drive sequence signal for opening the valve. Thereby, after the valve element 5 has once closed (step S
5) An opening operation is performed (step S6). On the other hand, when the discontinuous opening signal is input, only the motor drive sequence signal for opening the valve is output, so that the valve element 5 performs only the opening operation (step S6).

Next, a second embodiment of the present invention will be described. In FIG. 3, a stepping motor 4 is a stepping motor generally called a PM type, and a male screw 9 is engraved on a shaft 8 thereof. The male screw 9 is screwed with a female screw 10 provided on the valve body 5, and a guide rod 12 projecting from a base plate 11 of the stepping motor 4 is provided with a rotation stopper 13 provided on the valve body 5. The rotation of the shaft 8 is converted into a linear motion of the valve body 5 because the rotation of the valve body 5 is regulated by slidably fitting with the valve body 5.

A sealing member 1 made of rubber is provided on the tip end surface of the valve body 5.
4 is attached, and this sealing member 1
As shown in FIG. 3, the flow path 15 is shut off when the valve 4 comes into contact with the valve seat 6.

The valve body 5 is provided with a cylindrical stopper 16 projecting from the center opposite to the seal member 14 so as to surround a part of the shaft 8. The stepping motor 4 can be moved only to a position where the stepping motor 4 comes into contact with the base plate 11.

FIG. 4 shows the operation of the second embodiment shown in FIG. FIG. 4A shows a closed state in which the seal member 14 of the valve body 5 is in contact with the valve seat 6. When the opening operation is performed from this closed state, the valve element 5 moves to the stepping motor 4 side and the seal member 14 separates from the valve seat 6, but when the opening operation is continuously performed, the operation proceeds to (b). As shown, the stopper 16 abuts against the base plate 11 of the stepping motor 4, further restricting the movement of the valve element 5, and the stepping motor 4 is out of step. When the closing operation is performed from this state, as shown in (c), the valve element 5 is moved to a closed position where the seal member 14 abuts on the valve seat 6.

[0017]

According to the first aspect of the present invention, when an open signal is continuously input from the outside, the closing operation is performed once and then the opening operation is performed, so that the open signal is continuously output from the outside. Even when the input is made, the opening amount of the valve does not exceed the preset valve closing operation amount, and there is no possibility of a disconnection failure.

According to the second aspect of the present invention, even when the open signal is continuously input from the outside or the operation amount is insufficient for some reason during the previous closing operation,
Since the opening amount of the valve that is equal to or greater than the predetermined amount is limited by the stopper, the opening amount of the valve does not exceed the preset valve closing operation amount, and there is no possibility of a disconnection failure.

According to the third aspect of the invention, the effect of the second aspect of the invention can be realized only by projecting the stopper on the valve body.

[Brief description of the drawings]

FIG. 1 is a block diagram of a configuration according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the first embodiment.

FIG. 3 is a sectional view showing a structure according to a second embodiment of the present invention.

FIGS. 4A and 4B show the operation of the second embodiment.
It is operation | movement explanatory drawing shown separately to (c).

FIG. 5 is a block diagram of a configuration of a conventional example.

FIG. 6 is an operation explanatory diagram showing the operation of the conventional example divided into (a), (b) and (c).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive circuit 2 Control part 3 Drive part 4 Stepping motor 5 Valve body 6 Valve seat 7 Judgment part 8 Shaft 9 Male screw 10 Female screw 11 Base plate 12 Guide rod 13 Rotation stop part 14 Seal member 15 Flow path 16 Stopper

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H062 AA02 AA12 BB05 BB09 CC02 DD03 EE06 FF10 HH02 HH03 HH07 HH10 5H580 AA10 BB05 BB09 CA02 FA13 HH39 JJ01

Claims (3)

[Claims] 1. A flow path shut-off device comprising a valve element for opening and closing a flow path, a stepping motor for driving the valve element, and a drive circuit for controlling the stepping motor in response to an open signal and a close signal. A determination unit for determining whether or not an open signal is continuously input to the drive circuit; and when the determination result is a continuous input, controlling the stepping motor to perform a close operation and then perform an open operation. And a control unit for controlling the flow path. 2. A flow path shut-off device comprising a valve element for opening and closing a flow path, a stepping motor for driving the valve element, and a drive circuit for controlling the stepping motor in response to an open signal and a close signal. When the stepping motor is driven by a signal to move the valve body in the opening direction from the closed position to a certain distance, a stopper is provided for restricting further movement and causing the stepping motor to lose synchronism. Road blocking device. 3. The valve according to claim 2, wherein the stopper protrudes from the valve body, and when the stopper comes into contact with a base plate of the stepping motor, movement of the valve body in the opening direction is restricted. Channel shutoff device.