JP2014088938A - Shutoff valve and valve device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shutoff valve capable of reducing a load of driving means at valve opening drive, and capable of being easily assembled.SOLUTION: A shutoff valve comprises: a valve sheet of a flexible body capable of contacting with a valve seat formed in a flow channel; a holding member 24 arranged on the rear surface of the valve sheet 23; a stepping motor 25 driving the holding member 24 in the coaxial direction of the valve seat 22; and a groove 26 provided on the valve seat side of the valve sheet 23 and/or on the holding member side. The valve sheet 23 bends and deforms with a groove 26 as an original point at valve opening operation, a small aperture 42 is formed between the valve seat 22 and the valve sheet 23, and thereby differential pressure can be reduced with small driving force.

Description

  The present invention is a safety valve that operates according to an external situation, a valve that uses a magnet as an operation means, and a valve that uses an electric motor as an operation means, and is particularly used as a shut-off mechanism of a gas shut-off device that prevents a gas accident. More specifically, an electromagnetic solenoid or motor that performs a shut-off return operation of the flow path by moving the valve body forward or backward relative to a valve seat formed in the flow path is mainly used as a power source. The present invention relates to a shut-off valve built in a gas meter or the like.

  Various safety devices have been used in the past to prevent gas accidents that are likely to be a catastrophe once they occur. Among them, gas flow is monitored by a flow sensor built in a gas meter and gas is detected by a microcomputer. If the use status of the sensor is judged abnormal, or if the status of sensors such as seismic sensors, gas pressure sensors, gas alarms, carbon monoxide sensors is monitored and judged dangerous, the shutoff valve built in the gas meter The gas meter with built-in microcomputer gas shut-off device (hereinafter abbreviated as “microcomputer meter”) using a battery power source that shuts off the gas due to safety, ease of gas piping, low price, etc. has been promoted in recent years. Almost all households have been popularized.

  In addition, the ratio of centralized monitoring micrometers that have a telemeter function that centrally monitors gas flow rate information measured by a flow sensor using a telephone line or wireless communication will increase, making it more convenient as an information terminal. Improvement is demanded.

  There are two types of shutoff valve devices for this microcomputer meter.

  One is a shut-off valve device for an isolated microcomputer meter, which is driven electrically only when shut-off (closed), and the return operation is performed mainly by applying an external load, such as manually, and the external operation is transmitted to the shut-off valve. (This type of shutoff valve is hereinafter abbreviated as a unidirectional shutoff valve. The unidirectional shutoff valve is driven mainly by a self-holding electromagnetic solenoid).

  This return mechanism is a return shaft that urges the valve seat of the shut-off valve away from the valve seat, and many of them have an outer diameter slightly smaller than the valve seat so that gas does not leak even when the return shaft is kept pressed. And a second valve seat called an inner cylinder that is movable in the axial direction in conjunction with the return shaft.

  Between the inner cylinder and the valve seat, there is a gentle airtightness by a seal member.

  On the other hand, in central monitoring type microcomputer meters, etc., gas can also be shut off by electric energy from the battery installed in the microcomputer meter so that gas can be shut off and restored by simple electric switch operation, telephone line, wireless communication, etc. There is a demand for a shut-off valve (hereinafter abbreviated as a bi-directional shut-off valve) that does not require energy for maintaining the open state and the closed state.

  A bidirectional shut-off valve that uses an electric motor such as a self-holding electromagnetic solenoid or a stepping motor as a driving means has been put into practical use.

  These shut-off valves are arranged so that the gas upstream / downstream differential pressure is applied in the valve closing direction when the valve is closed in order to ensure the valve closing reliability.

Therefore, it is necessary to raise the load corresponding to the pressure receiving area to which the upstream / downstream differential pressure is applied when the valve is opened. For example, when a differential pressure of 5 kPa is applied to a pressure receiving area with a diameter of 28 mm, it is necessary to drive a load of about 3N (hereinafter referred to as a differential pressure load).

  On the other hand, in recent years, the load that urges the valve body of this type of shut-off valve in the valve closing direction, that is, the valve closing force, has been reduced in weight in order to achieve a 10-year drive with a battery power source or to realize further power saving. In some cases, the valve closing force relative to the circumferential length of the valve seat, that is, the line seal load is less than 10 mN / mm.

  In the case of a shutoff valve with a valve seat diameter of 28 mm and a wire seal load of 10 mN / mm, the valve closing force is 0.86 N, and the above-mentioned differential pressure load is a load that is 3.5 times the valve closing force. Therefore, it is necessary to have a driving force that raises the load about 4.5 times the valve closing force when the valve is opened, i.e., energy close to 4.5 times the energy required for valve closing is required to eliminate the differential pressure load. Necessary.

  Therefore, reducing the differential pressure load leads to power saving of the shut-off valve, so conventionally, it is possible to open the small-diameter sub-valve first, use the differential pressure of the pilot valve, etc. Various devices such as deforming a part of the valve seat of the flexible body have been made.

  The conventional means for reducing the differential pressure load of the shut-off valve will be described below.

  First, FIG. 6 shows a cross-sectional view of the valve portion of the shut-off valve of the first conventional example (see, for example, Patent Document 1).

  The valve portion of the shut-off valve includes a valve body 1 having a flexible body, and a plate-like body 3 that is attached to the valve stem 2 and is arranged in a floating state in the cavity of the valve body 1. The lifting member 4 is formed of a protrusion at an eccentric position.

  The operation of the valve portion of the shut-off valve configured as described above will be described.

  FIG. 6A shows a closed state of the valve portion, and the lower surface of the valve body 1 is in contact with the tip circumferential portion of the valve seat 5 and maintains a state where no gas flows.

  At this time, the downstream side of the valve seat 5 may be at atmospheric pressure, and since gas pressure is applied upstream, a differential pressure load corresponding to the pressure receiving area to which normal gas pressure is applied is applied in the valve closing direction. .

  When the valve portion of the shut-off valve performs a return valve opening operation, a pulling force from a driving means (not shown) is applied to the valve stem 2.

  This lifting force is transmitted to the flange 6 of the valve body 1 through the lifting member 4 of the plate-like body 3. On the other hand, since the differential pressure load is applied to the pressure receiving portion of the valve body 1 (inside the inner diameter of the valve seat 5), the back surface of the lifting member 4 is partially bent in the valve body 1, and the valve body 1 Only the valve seat 5 is detached and the state shown in FIG.

  In this way, the gas passage is formed and the differential pressure with the downstream is eliminated or reduced, whereby the differential pressure load is reduced, and the valve body 1 can be opened with a smaller driving force.

  Next, FIG. 7 shows a sectional view of the valve portion of the shutoff valve of the second conventional example (see, for example, Patent Document 2).

The valve portion of the shut-off valve includes a valve body 11 that is flexible in the valve opening and closing direction, and a convex portion 14 that is attached to the valve stem 12 and is close to or abuts a point on the valve seat side near the valve seat 13 of the valve body 11. The push-up member 15 is formed so as to push a point in the vicinity of the valve seat of the valve body 11 when the valve rod 12 starts the valve opening operation.

  The valve body 11 is disposed so as to be fitted to the clasp 16 of the valve stem 12, and a rigid holding member 17 is disposed on the back surface of the valve body 11 so as to be freely movable with the clasp 16. A gap 18 is formed at the center of the member 17.

  The operation of the valve portion of the shut-off valve configured as described above will be described.

  FIG. 7A shows a closed state of the valve portion, and the lower surface of the valve body 11 is in contact with the circumferential portion of the tip of the valve seat 13 and maintains a state in which no gas flows.

  At this time, the downstream side of the valve seat 13 may be at atmospheric pressure, and since gas pressure is applied upstream, a differential pressure load corresponding to the pressure receiving area to which normal gas pressure is applied is applied in the valve closing direction. .

  When the valve portion of the shut-off valve performs a return opening operation, a pulling force from a driving means (not shown) is applied to the valve rod 12.

  FIG. 7B is a cross-sectional view showing the state of each part immediately after the valve stem 12 starts moving in the opening direction.

  Since the valve body 11 is urged in the valve closing direction by the differential pressure load, when the valve rod 12 starts to move, first, the central portion of the valve body is locally bent so that the gap 18 is reduced, and the push-up member 15 is moved. Approach the valve body 11.

  As a result, the pulling force of the valve stem 12 is concentrated on the convex portion 14 close to the valve seat 13 and opens a part of the seal between the valve body 11 and the valve seat 13. In this way, the gas passage is formed and the differential pressure with the downstream is eliminated or reduced, whereby the differential pressure load is reduced, and the valve element 11 can be opened with a smaller driving force.

JP-A-4-282079 Japanese Patent Laid-Open No. 4-185981

  However, the shut-off valve of the first conventional example has a problem that the valve body 1 must be mounted on the plate-like body 3 and complicated assembly is required on the production line.

  Further, the shut-off valve of the second conventional example has a problem that the number of parts increases and the structure becomes complicated.

  In order to solve the above-described conventional problems, a shut-off valve according to the present invention is arranged on a flexible valve seat that can contact a valve seat formed in a flow path, and on a back surface of the valve seat with respect to the valve seat. The holding member, drive means for driving the holding member in the coaxial direction of the valve seat, and a groove provided on the valve seat side and / or the holding member side of the valve seat are provided.

  As a result, the valve seat is bent and deformed from the groove when the valve is opened, and an opening is formed between the valve seat and the valve seat, so that the differential pressure can be eliminated or reduced with a weak negative pressure, and the shape is simple. Therefore, a shut-off valve that can be easily assembled can be realized.

  The shut-off valve of the present invention has a high differential pressure cancellation effect that can reduce the load of the driving means because the differential pressure that can be returned and opened is high, and can have high reliability, is simple in shape, and is easy to assemble. , Can have high production efficiency.

Sectional drawing of the valve opening state of the shutoff valve in Embodiment 1 of this invention Sectional view of the valve closed Cross section when the valve is opened Perspective view of valve seat and holding member of same shut-off valve Graph showing the torque of the stepping motor when driving the valve and the load required for the valve seat to disengage from the valve seat (A), (b) Cross-sectional view of a conventional shut-off valve (A), (b) Cross-sectional view of another conventional shutoff valve

  A first invention is a valve seat made of a flexible body capable of contacting a valve seat, a holding member disposed on the back surface of the valve seat of the valve seat, and the holding member in a coaxial direction with the valve seat. Drive means for driving, and a groove disposed in the valve seat, and the valve seat is bent and deformed from the groove when the valve is opened, and an opening is formed between the valve seat and the valve seat. The pressure difference can be eliminated or reduced, and since the shape is simple, a shut-off valve that can be easily assembled can be realized.

  In the second invention, in particular, in the first invention, the driving means is an electric motor, and the holding member has a linear mechanism for converting rotation into linear motion.

  According to a third aspect of the present invention, particularly in the second aspect of the invention, there is provided control means for increasing the drive torque of the electric motor at least until the valve seat bent at the groove is detached from the valve seat at the time of valve opening drive. , Efficient driving, such as switching by high torque control from the time when the valve seat starts to bend from the groove to a stroke slightly longer than the stroke at which the valve seat completely disengages from the valve seat, and the other is driven by low torque drive A valve device for performing the above can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing the configuration of a shut-off valve in the present embodiment. As shown in the figure, the shut-off valve is made of a nitrile butadiene rubber or the like that can come into contact with a valve seat 22 formed in a flow path 21. A flexible valve seat 23 made of synthetic rubber, a holding member 24 made of synthetic resin such as polyoxymethylene disposed on the back surface of the valve seat 22 of the valve seat 23, and driving the holding member 24, The valve seat 23 is configured to include a stepping motor 25 that is a driving unit that drives in a direction in which the valve seat 23 abuts on or separates from the valve seat 22.

A lead screw 30 is formed on the rotating shaft 29 of the stepping motor 25, a lead nut 31 is formed in the center hole of the holding member 24, and is screwed together, and the holding member 24 is axially moved toward the stepping motor 25. A skirt 33 having a slit 32 is formed, and an engaging claw 35 that can be engaged with the slit 32 is formed in a central hole of a flange 34 that is a mounting plate of the stepping motor 25. A linear mechanism that restricts the rotation and converts the rotation of the rotary shaft 29 into a linear motion in the axial direction of the valve seat 22 is constituted by the lead screw 30, the lead nut 31, the slit 32, and the engaging claw 35. Yes.

  Further, the stepping motor 25 is a thrust / radial joint that has a non-magnetic metal thin plate can 40 and a seal member 36, and the rotor 37 and the stator 38 are hermetically maintained, and the outlet side of the rotary shaft 29 has little friction loss. Rolling bearings 39 are arranged.

  FIG. 4 shows the shape and configuration of the valve seat 23 and the holding member 24. As shown in the figure, the valve seat 23 has two joint legs on the back surface with respect to the valve seat 22 at positions symmetrical to the center. 27 are integrally provided, and two grooves 26 parallel to a straight line connecting the two joint legs 27 are provided at positions symmetrical to the straight line. The two joining feet 27 are respectively inserted into the two joining holes 28 provided in the holding member 24 and attached to the holding member. In the present embodiment, the groove 26 has two parallel straight lines. However, the present invention is not limited to this, and it is sufficient that the valve seat is deformed when it is detached from the valve seat and an opening 42 (described later) for releasing pressure is formed. Also, it may be a curve.

  In the present embodiment, the groove 26 is provided on the back surface of the valve seat 22. However, when the valve seat is detached from the valve seat, the valve seat is deformed to form an opening 42 (described later) for releasing pressure. For example, you may provide on the surface or both surfaces.

  The operation and action of the shut-off valve configured as described above will be described below.

  First, in the valve open state shown in FIG. 1, the holding member 24 moves backward to the stepping motor 25 side, the valve seat 23 is detached from the valve seat 22, and the valve open state in which a fluid such as gas can pass is held. ing.

  The shaft center of the valve seat 23 and the holding member 24 is generally held by the fitting of the joining foot 27 and the joining hole 28, and the valve seat 23 is not deformed because there is no differential pressure.

  When a gas flow rate is abnormal, an earthquake occurs, or when a shut-off command is issued by communication or external means, a shut-off valve signal from a control means such as a microcomputer meter (not shown) is applied to the stepping motor 25, and the rotor 37 is turned on. It rotates and is converted into a linear motion in the axial direction of the valve seat 22 via the lead screw 30 and the lead nut 31, the holding member 24 moves to the valve seat 22 side, and the valve seat 23 and the valve seat 22 come into contact with each other and close. Then, the holding member 24 is further pushed into the valve seat 22 side, the valve seat 23 is bent and deformed, and the entire circumference of the valve seat abutting portion 23a abuts on the valve seat 22 to shut off fluid such as gas. At the end of the valve closing signal, the stepping motor 25 steps out and ends the shut-off valve closing operation.

  FIG. 2 shows a cross-sectional view of the valve closing state when the differential pressure P is generated in the upstream and downstream of the valve seat 23 after shutting off and closing in this way.

  In FIG. 2, the valve seat 23 is pressed against the valve seat by the biasing force of the differential pressure P.

  At the end of the shut-off valve closing operation, after the step-out operation, the rotor 37 is slightly reversed so that the stress between the valve seat 23 and the lead screw 30 and the lead nut 31 is removed and stabilized by the spring 41. A valve closing force can be applied, and there is little possibility of permanent deformation or the like, and a valve device with high long-term reliability can be realized.

  Next, the return valve opening operation will be described with reference to FIGS.

  When returning from the valve opening, it is necessary to raise the load corresponding to the pressure receiving area applied to the upstream and downstream pressure difference of the valve seat 23. For example, when a differential pressure of 5 kPa is applied to the pressure receiving area of 28 mm in diameter, a differential pressure load of about 3N is applied. Need to drive.

  On the other hand, reducing the differential pressure load leads to realizing power saving of the shut-off valve in order to target driving for 10 years with a battery power source or to realize further power saving.

  When a return valve opening signal from a control means such as a microcomputer meter (not shown) is applied to the stepping motor 25, the rotor 37 rotates in the reverse direction during the shut-off valve closing operation, via the lead screw 30 and the lead nut 31. Therefore, the holding member 24 moves in a direction away from the valve seat 22, and the valve seat 23 is bent and deformed starting from the groove 26, so that the valve seat 22 is displaced between the valve seat 22 and the valve seat 23. The opening 42 is formed and the state shown in FIG.

  In the return valve opening operation so far, since the valve seat 23 is bent and deformed so as to peel from the valve seat 22 starting from the groove 26, the opening 42 can be formed with a weaker load.

  When the opening 42 is formed between the valve seat 22 and the valve seat 23, a small amount of fluid can flow, and this flow causes the side of the valve seat 22 of the valve seat 23 to have a high pressure portion, and the back surface has a low pressure portion. As a result, the differential pressure upstream and downstream of the valve seat 23 decreases, the valve seat 23 cannot contact the valve seat 22, and finally the entire circumference of the valve seat abutting portion 23a of the valve seat 23 extends from the valve seat 22. After that, the pressure difference is rapidly eliminated, and the valve seat 23 moves to the stepping motor 25 side integrally with the holding member 24, and returns to the valve opening state shown in FIG.

  Even in the return valve opening operation, after the holding member 24 abuts on the stepping motor 25 and performs the step-out operation, the operation between the lead screw 30 and the lead nut 31 is performed by slightly rotating the rotor 37 reversely. It is possible to realize a valve device with high long-term reliability that is less likely to cause permanent deformation.

  Further, since the valve seat 23 and the groove 26 are integrally formed, no additional means is required for assembly.

  Thus, according to the first embodiment, since the differential pressure that can be returned and opened is high, the load on the driving means can be reduced, and a shut-off valve that does not require additional means for assembly can be realized.

  Furthermore, the valve device in the present embodiment is configured by control means capable of switching the driving torque generated by the stepping motor 25.

  FIG. 5 is a graph showing the relationship between the torque and the load required to raise the holding member and the position of the holding member during the return valve opening operation of the valve device.

  In FIG. 5, at the time of return opening, the control means switches from a position at which the valve seat 23 begins to bend at the groove 26 to a slightly longer stroke than a position at which the valve seat 23 separates from the valve seat 22 by high torque control.

  By driving in this way, the holding member 24 is driven with a high load until the differential pressure P is eliminated or reduced in the return valve opening operation of the shut-off valve, and the valve seat 23 is peeled off from the valve seat 22, and thereafter It is possible to realize a valve device that switches to low torque driving that can suppress electric power and performs efficient driving that can reduce power consumption.

  As described above, the shut-off valve and the valve device according to the present invention can reduce the load on the driving means because of the high differential pressure that can be restored and opened, and the shape is simple, so additional means are required for assembly. It has a high differential pressure canceling effect such as “No” and is highly reliable, and can be used for a fluid control valve having a shut-off valve function.

21 Flow path 22 Valve seat 23 Valve seat 24 Holding member 25 Stepping motor (drive means, electric motor)
26 Groove 29 Rotating shaft (Linear mechanism)
30 Lead screw (linear mechanism)
31 Lead nut (linear mechanism)

Claims (3)

A flexible valve seat capable of contacting a valve seat formed in the flow path;
A holding member disposed on the back surface of the valve seat with respect to the valve seat;
Driving means for driving the holding member in the coaxial direction of the valve seat, and a groove provided on the valve seat side and / or the holding member side of the valve seat;
Shut-off valve with The shut-off valve according to claim 1, wherein the driving means is an electric motor, and the holding member has a linear mechanism that converts rotation into linear motion. 3. A valve device comprising the shutoff valve according to claim 2 and comprising control means for increasing the drive torque of the electric motor at least until the valve seat bent at the groove is detached from the valve seat during valve opening drive.