JP4286117B2 - Emergency shut-off valve - Google Patents

Description

  The present invention relates to an emergency shut-off valve that shuts a flow path by itself when an earthquake or the like occurs.

  Conventionally, as an emergency shut-off valve of this type, for example, as shown in FIG. 15, a first weight 72 provided on a first swing arm 71 interlocked with a valve rod 70 urges a valve body 73 in a closing direction. A stopper 74 that holds the first weight 72 in a non-acting state against the urging force, a stopper action release mechanism 75 that releases the action of the stopper 74, and a flow velocity (dynamic pressure) in the valve box 76 There is a device provided with a detecting means 77 for detecting (see Patent Document 1).

  The first swing arm 71 is provided at one end of the valve rod 70. The stopper 74 includes a hip-fold link 78. The hip-fold link 78 is linked to a swingable arm 79 provided at the other end of the valve rod 70, and the hip-break is prevented in a substantially straight state. The first weight 72 is configured to be stretched and supported while being urged to rotate the valve body 73 in the closing direction by its own weight.

  Further, when the flow rate in the valve box 76 is abnormally increased, the detection unit 77 detects this abnormal flow rate, and based on this detection, the stopper action release mechanism 75 releases the tension of the waist folding link 78. Has been.

  The stopper action release mechanism 75 is provided at the free end of the second swing arm 81 swingable around the horizontal axis, and at the base end of the second swing arm 81 and is folded back. A pin 83 that comes into contact with the link 78 to release the tension, a locking rod 84 that is connected to the second swinging arm 81, and the second swinging arm 81 with the weight of the second weight 82 are used to remove the waist break link 78. A swingable locking member 85 that locks the locking rod 84 in a state of being biased to swing and displace toward the tension release side, and a sensor weight that biases the locking member 85 toward the locked state maintaining side. 86.

  The detection means 77 includes a pressure receiving portion 87 that receives the dynamic pressure in the valve box 76 and a detection arm 88 that swings by the pressure receiving portion 87. The detection arm 88 and the locking member 85 are interlocked and connected via a lever 89 and a connecting rod 90.

  According to this, when a part of the pipe line is broken due to an earthquake or the like, the flow velocity in the valve box 76 rises abnormally, the pressure receiving portion 87 is pushed and the detection arm 88 swings, and this detection arm 88 The locking member 85 swings in conjunction with the release of the locking rod 84 to release the locking. Accordingly, the second swing arm 81 swings from the standing posture (standby state) to the sideways posture by the own weight of the second weight 82, and the pin 83 comes into contact with the waist folding link 78 from below to release the tension. . As a result, the hip link 78 bends upward, and the first weight 72 causes the first swing arm 71 to swing from the standing posture to the sideways posture, and the valve body 73 rotates in the closing direction together with the valve rod 70. Then, the flow path in the valve box 76 is urgently blocked.

  However, in the above conventional type, in order to release the stopper action, it is necessary to swing the second weight 82 and release the tension of the hip-fold link 78, so that a large space for swinging the second weight 82 is required. There are problems such as that and the mechanism is complicated. Further, since the second weight 82 swings vigorously by its own weight, there is a problem that it is necessary to take safety measures such as providing a cover for preventing danger.

  In addition, after the second swing arm 81 swings from the standing posture to the sideways posture and the valve body 73 is urgently shut off, the operator goes to the site to return the valve body 73 from the closed position to the fully opened position. Furthermore, there is a problem that it is necessary to return the second swing arm 81 from the sideways posture to the standing posture which is a standby state, which takes time.

Furthermore, as the diameter of the emergency shut-off valve increases, the first weight 72 needs to be enlarged and the second weight 82 needs to be enlarged accordingly. There is a problem that the handling of the time is difficult, the cost increases, and the space required for installation increases.
JP 54-136419 A

  The present invention can eliminate the need for the second weight for releasing the stopper action, can simplify the mechanism, can easily perform the return work after the emergency shut-off, and can suppress the increase in size. The purpose is to provide an emergency shut-off valve.

In order to achieve the above object, according to the first aspect of the present invention, a weight provided on a swing arm interlocking with a valve rod urges the valve body in a closing direction, and the valve body is closed and opened. An emergency shut-off valve provided with holding means for swinging the swing arm between positions and holding the swing arm in an open position;
The holding means includes a first lever body that latches and holds the swing arm in the open position, and a second lever body that latches and holds the first lever body. A holding groove is formed, and the first lever body has a holding position for holding the first fixing pin provided in the swing arm in the holding groove, and the first fixing pin is detached from the holding groove outward. The second lever body can be pivoted to a first lever body that pivots from the holding position to the separation position via a locking pin. When the swing arm is held in the open position, the first fixing pin is fitted into the holding groove, and is eccentric with respect to the rotation center of the first lever body. A rotational moment from the holding position to the release position is applied to the body, and the second lever body is resisted against the rotational moment. A second fixing pin for fixing the movement is provided, and the second fixing pin is engaged with and locked to the second lever body, and is released from the second lever body to release the lock. It can be switched to the fixed release position.

  According to this, in a normal state, the second fixing pin is switched to the fixing position, the second lever body is fixed, and the first lever body is locked and held by the second lever body and fixed to the holding position. Has been. At this time, the first fixing pin is fitted and held in the holding groove, whereby the swing arm is held in the open position against the weight of the weight, and the valve body is kept in the open state. Since the first fixing pin fitted in the holding groove is eccentric with respect to the rotation center of the first lever body, the first lever body rotates from the holding position to the release position. A moment is generated, and the rotation of the first lever body is fixed against the rotational moment.

  At this time, the rotational force applied to the first lever body by the weight is the distance from the center of rotation of the first lever body to the first fixing pin and the distance from the center of rotation of the first lever body to the locking pin. The distance from the rotation center of the second lever body to the locking pin and the distance from the rotation center of the second lever body to the second fixing pin. It is reduced according to the ratio. Thus, the rotational force can be reduced in two stages by the first and second lever bodies, and the reduced rotational force acts on the second fixing pin at the fixed position. The fixing pin can be made thin.

  In addition, when an earthquake or the like occurs, the second fixing pin is switched from the fixing position to the fixing releasing position, and the second lever body is released from the fixing state so that it can freely rotate. As a result, the first lever body that has been fixed at the holding position is also unfixed and turned freely, and the first lever body is rotated from the holding position to the disengagement position by the rotational moment, and the first fixing is performed. The pin is disengaged outward from the holding groove, the swing arm swings from the open position to the closed position by the weight of the weight, the valve body closes, and the flow path is shut off urgently. At this time, the second lever body is also rotated in the same direction as the first lever body by being engaged with the first lever body that is rotated from the holding position to the release position by the rotational moment.

  As described above, when an earthquake or the like occurs, it is possible to cancel the holding action of the swing arm held in the open position without using the second weight as in the prior art. It can be made unnecessary.

  In addition, when the diameter of the emergency shut-off valve is increased and the weight is increased, the eccentricity of the first fixing pin with respect to the center of rotation of the first lever body is shortened to generate the first lever body. Rotational moment can be kept constant. As a result, the force received by the second fixing pin from the second lever body at the fixed position can be made constant, and the enlargement of the second fixing pin and the holding means can be avoided. Increase in size is suppressed.

  In the second aspect of the invention, the first lever body and the second lever body are configured to rotate with respect to each other via the interlocking connecting means, and the second fixing pin is biased toward the fixed position. An urging means is provided.

  According to this, when the valve body is urgently closed due to an earthquake, etc., and the valve body is returned from the closed state to the open state, the swinging arm is opened from the closed position against the weight of the weight. At this time, the first fixing pin of the swinging arm is fitted into the holding groove of the first lever body rotated to the disengagement position, and the first fixing pin in the holding groove changes to move the first fixing pin. The second lever body is rotated in the same direction as the first lever body in conjunction with the first lever body via the interlocking connecting means. The second fixing pin is switched to the fixing position by the urging means, and the second lever body is fixed.

Therefore, by returning the valve body from the closed state to the open state after the emergency shut-off, the holding means automatically returns to the normal standby state accordingly, so that the return operation is facilitated.
Further, according to the third aspect of the present invention, the interlocking connecting means includes a locking groove formed in the second lever body, and a locking provided in the first lever body and guided by engaging with the locking groove. It consists of pins.

  According to this, when the first lever body rotates, the locking pin moves along the locking groove while being guided by the locking groove, and the second lever body interlocks with the first lever body. Then rotate.

  According to the first aspect of the present invention, the rotational force applied to the first lever body by the weight can be reduced in two stages by the first and second lever bodies, and the reduced rotational force can be reduced at the fixed position. Since it acts on the two fixing pins, the second fixing pin can be made thin.

  Further, when an earthquake or the like occurs, the second weight is not necessary because the holding action of the swing arm held in the open position can be canceled without using the second weight as in the prior art. This eliminates the need for a large space for swinging the second weight, simplifies the mechanism, and eliminates the need for a danger prevention cover. Further, even when the diameter of the emergency shut-off valve is increased and the weight is increased, the second fixing pin and the holding means can be prevented from being enlarged, and the overall emergency shut-off valve is prevented from being enlarged. .

  According to the second aspect of the invention, after the emergency shut-off, by returning the valve body from the closed state to the open state, the holding means is automatically returned to the standby state at the normal time. become.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 3, reference numeral 1 denotes an emergency shut-off valve, and a rotatable valve rod 3 is horizontally inserted into the valve box 2, and a flow path 4 in the valve box 2 is inserted into the valve rod 3. A disc-like valve body 5 is provided for opening and closing.

On the outside of the valve box 2, a detection means 10 for detecting the flow velocity in the valve box 2 is provided. The detection means 10 is configured as follows.
That is, as shown in FIGS. 4 to 6, a pressure receiving portion 11 that receives the fluid flow pressure is projected into the valve box 2, and the pressure receiving portion 11 is formed by a paddle 12 that can swing back and forth along the flow direction A. It is provided at the lower end. The upper end portion of the paddle 12 is provided on a pivot shaft 13, and the pivot shaft 13 is inserted horizontally in a sealed cylinder 14 provided on the upper portion of the valve box 2 and is rotatably held. . A lever lever 15 that is long in the front-rear direction is fixed to an end portion of the pivot shaft 13 that protrudes from the sealed cylindrical body 14 to the outside, and an adjustment weight 16 is provided on the lever rod 15.

  As shown in FIGS. 1 to 3, the emergency shut-off valve 1 is provided with a weight 20 that urges the valve body 5 in the closing direction. That is, the weight 20 is provided at the free end of the swing arm 21, and the base end of the swing arm 21 is provided at one end of the valve rod 3 that protrudes outward from the valve box 2. The swing arm 21 swings between a closed position S (see the phantom line in FIG. 1) where the valve body 5 is closed and an open position O (see the solid line in FIG. 1) where the valve body 5 is fully opened. To do. The swing arm 21 is provided with a first fixing pin 22.

  Furthermore, the emergency shut-off valve 1 is provided with a holding means 25 that holds the swing arm 21 in the open position O. The holding means 25 includes a first lever body 26 that latches and holds the swing arm 21 at the open position O, and a second lever body 27 that latches and holds the first lever body 26. The first and second lever bodies 26 and 27 are rotatably provided on a mounting plate 28 fixed to one outer side of the valve box 2.

  As shown in FIG. 7, the first lever body 26 includes a disc portion 26 a and a projecting piece portion 26 b provided in a radial direction from the outer peripheral portion of the disc portion 26 a. A holding groove 29 is formed in the disk portion 26a. The first fixing pin 22 is detachable with respect to the holding groove 29, and the first lever body 26 has a holding position B for holding the first fixing pin 22 in the holding groove 29, and a first The fixing pin 22 is rotated to a separation position C (see FIG. 11) where the fixing pin 22 is detached from the holding groove 29 outward. Further, when the swing arm 21 is held at the open position O as shown by a solid line in FIG. 1, the first fixing pin 22 is fitted into the holding groove 29 as shown in FIG. The lever body 26 is decentered by a predetermined distance L1 with respect to the rotation center D of the lever body 26, so that a rotational moment M in the direction from the holding position B to the separation position C is applied to the first lever body 26. Yes.

  Further, the second lever body 27 is formed in a fan shape, and is interlocked and connected to the first lever body 26 via the interlocking connecting means 32, and rotates in conjunction with the first lever body 26. . In other words, the interlocking connecting means 32 includes a locking groove 33 and a locking pin 34 that is engaged and guided in the locking groove 33. The locking groove 33 is formed in the second lever body 27, and the locking pin 34 is provided at the tip of the protruding piece portion 26 b of the first lever body 26. As shown in FIG. 8, when the first lever body 26 is stopped at the holding position B, the locking pin 34 is only a predetermined distance L2 from the rotation center E of the second lever body 27. It is eccentric. A locking portion 35 is formed on the outer peripheral portion of the second lever body 27.

  As shown in FIG. 12, a second fixing pin 38 for fixing the rotation of the second lever body 27 is inserted into the cylindrical member 37 provided on the mounting plate 28. The second fixing pin 38 is locked to the locking portion 35 of the second lever body 27 to lock the second lever body 27, and the locking portion 35 is referred to as a solid line in FIG. It is configured to move out to and from a fixed release position H (see the phantom line in FIG. 12) that releases the lock and releases the lock.

  Further, an L-shaped switching lever 40 that is swingable about a longitudinal axis 39 is provided on the back side of the mounting plate 28, and a base end of the second fixing pin 38 is provided at one end of the switching lever 40. Are connected. Further, a spring 41 (an example of a biasing unit) that biases the second fixing pin 38 to protrude to the fixing position G is provided on the back side of the mounting plate 28.

  As shown in FIGS. 6 and 12, the detection means 10 and the second fixing pin 38 are linked via a wire 43 (an example of a transmission means). That is, one end of the wire 43 is connected to an arm 44 provided on the outer peripheral surface of the end of the pivot shaft 13 of the detecting means 10, and the other end of the wire 43 is connected to the other end of the switching lever 40. Yes.

  As shown in FIG. 1, the mounting plate 28 is provided with a relaxation device 45 that relaxes the swing speed of the swing arm 21 that swings from the open position O to the closed position S. A hydraulic cylinder is used. As shown in FIGS. 2 and 3, an operating device 46 is provided outside the valve box 2 to rotate the valve rod 3 by manual operation to return the valve body 5 from the closed state to the fully opened state. Yes. The operating device 46 is connected to the other end of the valve stem 3 and has a handle 47 and a speed reducer 48.

Hereinafter, the operation of the above configuration will be described.
Under normal conditions, the flow velocity in the valve box 2 does not rise abnormally, and the fluid pressure acting on the pressure receiving portion 11 of the detection means 10 is not more than the set value. As shown by the solid line in FIG. The normal position P1 is maintained. At this time, as shown by the solid lines in FIGS. 7 and 12, the second fixing pin 38 is pushed by the spring 41 and protrudes to the fixing position G and is locked to the locking portion 35. The rotation of the lever body 27 is fixed, and the first lever body 26 is fixed to the holding position B via the interlocking connection means 32.

  At this time, the first fixing pin 22 is fitted and held in the holding groove 29, so that the swing arm 21 is moved to the open position O against the weight of the weight 20 as shown by the solid line in FIG. The valve body 5 is held in a fully open state. As shown in FIG. 7, since the first fixing pin 22 fitted in the holding groove 29 is eccentric with respect to the rotation center D of the first lever body 26, the first lever body 26 is provided. A rotational moment M is generated in the first lever body 26 against the rotational moment M, and the rotation of the first lever body 26 is fixed.

  In this state, as shown in FIG. 8, the distance from the rotation center D of the first lever body 26 to the locking pin 34 is L3, and the second center from the rotation center E of the second lever body 27 is the second. The distance to the fixing pin 38 is L4, the force acting on the first lever body 26 from the first fixing pin 22 according to the weight of the weight 20 is F1, and the force acting on the locking pin 34 is F2. Of the force F2, the force component in the direction of rotating the second lever body 27 is F3, the force acting on the second fixing pin 38 from the second lever body 27 is F4, and the force F2 and the force F3 1 and α, the weight of the weight 20 is W, and the inclination angle of the swing arm 21 at the open position O is β, as shown in FIG. 1, from the center of rotation of the valve stem 3 to the center of gravity of the weight 20. The distance from the center of rotation of the valve stem 3 to the first is L5 If the distance to the center of the fixed pin 22 is L6, the following balance equation is established.

M = F1 * L1 = F2 * L3 (Formula 1)
F2 = F3 × cos α (Formula 2)
F3 × L2 = F4 × L4 (Formula 3)
F1 = W × sin β × (L5 / L6) (Formula 4)
The following (Expression 5) can be derived based on the above (Expression 1) to (Expression 4).

F4 = F1 × (1 / cos α) × (L1 / L3) × (L2 / L4)
= W × sin β × (L5 / L6) × (1 / cos α) × (L1 / L3)
× (L2 / L4) (Formula 5)
As shown in the above (Formula 5), the rotational force F1 applied to the first lever body 26 by the weight 20 is an eccentric distance L1 from the rotation center D of the first lever body 26 to the first fixing pin 22. And the distance L3 from the rotation center D to the locking pin 34, and the eccentric distance L2 from the rotation center E of the second lever body 27 to the locking pin 34 and the above-mentioned distance L3. It is reduced according to the ratio with the distance L4 from the rotation center E to the second fixing pin 38. Thus, the rotational force F1 can be reduced in two stages by the first and second lever bodies 26 and 27, and the reduced rotational force F4 is applied to the second fixing pin 38 at the fixed position G. In order to act, the 2nd fixing pin 38 can be made thin.

  In addition, a part of the pipeline is destroyed due to an earthquake disaster, the flow velocity in the valve box 2 rises abnormally, and the fluid pressure acting on the pressure receiving portion 11 of the detection means 10 also rises and exceeds the set value. In this case, as shown by the phantom line in FIG. 6, the pressure receiving portion 11 is pushed by the fluid pressure and changes to the downstream position P2. As a result, the paddle 12 swings downstream, the pivot shaft 13 rotates, the wire 43 is pulled in the direction of arrow A, and the switching lever 40 is moved to the spring 41 as shown by the phantom line in FIG. As a result, the second fixing pin 38 retreats from the fixing position G to the fixing releasing position H and is released from the locking portion 35, and the second lever body 27 is released from the fixing state. The first lever body 26 fixed to the holding position B is released from being fixed and can be rotated. As a result, the first lever body 26 is rotated from the holding position B (see FIG. 7) to the disengagement position C (see FIG. 11) by the rotational moment M, and the first fixing pin 22 is tilted downward from the holding groove 29. 1, the swing arm 21 swings from the open position O to the closed position S due to the weight of the weight 20, and the valve body 5 closes and the flow path in the valve box 2 is closed, as indicated by the phantom line in FIG. 1. Emergency shut off 4 At this time, as shown in FIGS. 7 to 11, the locking pin 34 is guided and shifted by the locking groove 33, and the second lever body 27 is interlocked with the first lever body 26 to change the first lever body 26. The lever body 26 rotates in the same direction. Further, the second fixing pin 38 is prevented from protruding to the fixing position G by the outer peripheral portion 27 a of the second lever body 27.

  As described above, when an earthquake disaster or the like occurs, the holding action of the swing arm 21 held at the open position O can be released without using the second weight as in the prior art. The weight can be made unnecessary, thereby eliminating the need for a large space for swinging the second weight, simplifying the mechanism, and eliminating a danger prevention cover or the like.

  Further, when the diameter of the emergency shut-off valve 1 is increased and the weight 20 is enlarged, the eccentric amount L1 of the first fixing pin 22 with respect to the rotation center D of the first lever body 26 as shown in FIG. Is shortened, the rotational moment M generated in the first lever body 26 can be kept constant. For example, when the weight W of the weight 20 is doubled, the rotational moment M is kept constant by reducing the eccentricity L1 to ½. Accordingly, the force F4 received by the second fixing pin 38 from the second lever body 27 at the fixing position G can be made constant, and the second fixing pin 38 and the holding means 25 can be prevented from being enlarged. The enlargement of the entire emergency shutoff valve 1 is suppressed.

  In addition, after the valve body 5 is closed due to an earthquake disaster or the like, as shown in FIG. 3, the operator turns the valve rod 3 by turning the handle 47 of the operating unit 46 to close the valve body 5. To fully open. As a result, the swing arm 21 swings from the closed position S to the open position O against the weight of the weight 20, and at this time, the first fixing pin 22 rotates to the disengagement position C (see FIG. 11). The first lever body 26 is fitted into the holding groove 29 of the first lever body 26, and the first lever body 26 is rotated from the disengagement position C to the holding position B (see FIG. 7) by the displacement of the first fixing pin 22 in the holding groove 29. Further, the locking pin 34 is guided and shifted by the locking groove 33, and the second lever body 27 rotates in the same direction as the first lever body 26 in conjunction with the first lever body 26. Then, the second fixing pin 38 is pushed by the spring 41 and protrudes from the fixing release position H to the fixing position G and is locked to the locking portion 35. As a result, the second lever body 27 is fixed, and the normal standby state is restored.

  Therefore, after the emergency shut-off, the operating unit 46 is operated to return the valve body 5 from the closed state to the fully open state. At the same time, the holding means 25 automatically returns to the normal standby state. It becomes easy. If the valve body 5 is returned to the fully open state as described above, the rotation of the valve body 5 in the closing direction is restricted by the operating device 46, and therefore the valve body 5 is returned to the fully open state. After that, the operating device 46 is reversely operated in a range of about 90 °, and the restriction of the rotation of the valve body 5 in the closing direction by the operating device 46 is canceled.

  In the first embodiment, as shown in FIGS. 6 and 12, as an example of the transmission means, the detection means 10 and the second fixing pin 38 are interlocked via a wire 43, but the wire It is not limited to 43, and instead of the wire 43, for example, a member that transmits force such as a connecting rod may be used.

  Further, in the second embodiment described below, as shown in FIGS. 13 and 14, the second fixing pin 38 is adsorbed using the solenoid 51 as the transmission means without using the wire 43. .

  That is, the solenoid 51 is provided on the back side of the mounting plate 28, and as shown by the phantom line in FIG. 13, the second fixing pin 38 is adsorbed against the urging force of the spring 41 when energized to fix the position. Retreat to H. Further, when the solenoid 51 is not energized, no attracting force of the solenoid 51 is generated, and the second fixing pin 38 protrudes to the fixing position G by the biasing force of the spring 41 as shown by the solid line in FIG. .

  As shown in FIG. 14, the detection means 10 is provided with a limit switch 52 that is switched from off to on when the pressure receiving portion 11 changes from the normal position P1 to the downstream position P2. That is, the limit switch 52 is installed on the outside of the sealed cylindrical body 14 and is turned on and off by the swing piece 53 provided at one end of the pivot shaft 13. A control unit 54 is provided to energize the solenoid 51 when the limit switch 52 is on and to de-energize the solenoid 51 when the limit switch 52 is off.

  According to this, as shown by the solid line in FIG. 14, the pressure receiving unit 11 is maintained at the normal position P <b> 1, so that the limit switch 52 is turned off and the control unit 54 deenergizes the solenoid 51. . Thereby, the suction force of the solenoid 51 is not generated, and as shown by the solid line in FIG. 13, the second fixing pin 38 is pushed by the spring 41 and protrudes to the fixing position G to be locked to the locking portion 35. The rotation of the second lever body 27 is fixed.

  In addition, when the earthquake or the like occurs and the flow pressure acting on the pressure receiving unit 11 abnormally increases and exceeds the set value, the pressure receiving unit 11 is located at the downstream position P2 as indicated by a virtual line in FIG. Therefore, the limit switch 52 is turned on, and the control unit 54 energizes the solenoid 51. As a result, an attracting force of the solenoid 51 is generated, and the second fixing pin 38 retreats to the fixing release position H against the urging force of the spring 41 as shown by the phantom line in FIG. The second lever body 27 is released from being released from 35.

In each of the above embodiments, the interlocking connecting means 32 is constituted by the locking groove 33 and the locking pin 34, but may be constituted by a gear or the like.
In each said embodiment, although the 1st and 2nd lever bodies 26 and 27 are formed in circular shape, it is not limited to circular shape.

It is a side view of the emergency cutoff valve in the 1st Embodiment of this invention. It is a top view of an emergency cutoff valve. It is a front view of an emergency cutoff valve. It is a side view of the detection means which detects the flow velocity in the valve box of an emergency cutoff valve. It is a XX arrow line view in FIG. It is a figure explaining the action | operation of the detection means of an emergency cutoff valve. It is a figure of the holding means of an emergency cutoff valve, and shows the state where the swing arm is held in the open position. It is a figure explaining the balance of the force of the holding means of an emergency cutoff valve. It is a figure which shows a mode that the 1st lever body of the holding means of an emergency cutoff valve is rotating toward the detachment position from a holding position. It is a figure which shows a mode that the 1st lever body of the holding means of an emergency cutoff valve is rotating toward the detachment position from a holding position. FIG. 6 is a view showing a state where the first lever body of the holding means of the emergency shut-off valve is rotated to the disengagement position and the first fixing pin is disengaged from the holding groove. It is a figure which shows the withdrawal mechanism of the 2nd fixing pin of an emergency cutoff valve. It is a figure which shows the withdrawal mechanism of the 2nd fixing pin of the emergency cutoff valve in the 2nd Embodiment of this invention. It is a figure explaining the action | operation of the detection means of an emergency cutoff valve. It is a side view of the conventional emergency shut-off valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Emergency shut-off valve 3 Valve stem 5 Valve body 20 Weight 21 Swing arm 22 First fixing pin 25 Holding means 26 First lever body 27 Second lever body 29 Holding groove 32 Interlocking connection means 33 Locking groove 34 Engagement Stop pin 38 Second fixing pin 41 Spring (biasing means)
B Holding position C Detaching position D Rotation center G of the first lever body Fixed position H Unfixed position M Rotating moment O Open position S Closed position

Claims (3)

A weight provided on a swing arm interlocking with the valve rod urges the valve body in the closing direction, and the swing arm swings between a closed position where the valve body is closed and an open position where the valve body is opened. An emergency shut-off valve provided with holding means for holding the swing arm in the open position,
The holding means includes a first lever body that latches and holds the swing arm in the open position, and a second lever body that latches and holds the first lever body. A holding groove is formed, and the first lever body has a holding position for holding the first fixing pin provided in the swing arm in the holding groove, and the first fixing pin is detached from the holding groove outward. The second lever body can be pivoted to a first lever body that pivots from the holding position to the separation position via a locking pin. When the swing arm is held in the open position, the first fixing pin is fitted into the holding groove, and is eccentric with respect to the rotation center of the first lever body. A rotational moment from the holding position to the release position is applied to the body, and the second lever body is resisted against the rotational moment. A second fixing pin for fixing the movement is provided, and the second fixing pin is engaged with and locked to the second lever body, and is released from the second lever body to release the lock. An emergency shut-off valve configured to be switchable to a fixed release position. The first lever body and the second lever body are configured to rotate with respect to each other via interlocking connection means, and biasing means for biasing the second fixing pin toward the fixed position side is provided. The emergency shut-off valve according to claim 1, wherein: The interlocking connecting means is composed of a locking groove formed in the second lever body and a locking pin provided in the first lever body and guided by engaging with the locking groove. The emergency shut-off valve according to claim 2,

Images