JPH11211524A - Flow velocity detecting mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the size of a product and to make over flow velocity that starts the rotation of a flow sensor, finely controllable by constituting a flow velocity detecting mechanism of a spring to energize a flow sensor against the interference of a passing fluid and of a spring force regulating mechanism which can regulate the spring force of the spring steplessly. SOLUTION: When a piping on the downstream side from an emergency shutdown valve is damaged, for example, due to such as the occurrence of an earthquake and the flow velocity of passing water flow exceeds a set value, a flow sensor 11 is rotated to a location indicated by a virtual line, and a sensor lever 14 is supported with its right side up as indicated by a virtual line. By this, the rod 21 of an engaging and disengaging mechanism 20 is pulled up, and a latch lever 22 is rotated clockwise to the second location indicated by a virtual line to remove an engaging nail 22d from the nail part of a latch 31 in a rotating mechanism 30. By releasing the engagement between the engaging nail 22d of the latch lever 22 and the nail part of the latch 31, it is possible to open a valve element and to block water flow automatically. The spring force of a spring 60 is regulated by rotating the nut 21 of a spring force regulating mechanism. By this, it is possible to perform stepless fine control over flow velocity that starts the rotation of the flow sensor 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow velocity detecting mechanism attached to an emergency shutoff valve for urgently shutting off a pipeline when, for example, an earthquake occurs.

[0002]

2. Description of the Related Art Conventionally, in the event of an emergency when a water distribution pipe functioning as a fluid passage is damaged by an earthquake, an emergency shutoff valve has been devised so as to automatically shut off the flow of water through the fluid passage. The emergency shutoff valve shown in FIG. 3 is known. In this figure, 1 is a valve box, 2 is a valve body,
Reference numeral 3 denotes a valve stem, and pipes 4A and 4B are provided at both ends of the valve box 1.
When the valve body 2 is opened as shown in the figure, water passes in the direction from the pipe 4A to the pipe 4B as indicated by the arrow W. On the other hand, the closed state of the fluid passage can be obtained by rotating the valve body 2 fixed to the valve rod 3 together with the valve rod 3 about 90 degrees about its axis and closing the valve. This type of emergency shutoff valve includes a flow velocity detection mechanism 10, an engagement / disengagement mechanism 20, a rotation mechanism 30, a torque generation source 40, and a link mechanism 50.

[0003] The flow velocity detecting mechanism 10 is configured to detect the flow velocity of the passing water flow W and to operate when the flow velocity reaches a set value. That is, as shown in FIGS. 3 to 6, a flow sensor 11 protruding into the valve box 1, a sensor horizontally and rotatably supported in a hood 12 mounted on the valve box 1 in a watertight manner. A sensor lever 14 having a fulcrum fixed to an end of the sensor shaft 13 outside the shaft 13 and the hood 12, a balance weight 15 fixed to one end of the fulcrum of the sensor lever 14, and a fulcrum of the sensor lever 14 A sensor weight 16 is provided on the other side and attached to a sensor lever 14 so as to be slidable and positionable in the direction of arrow X. The upper end of the flow sensor 11 is fixed to a sensor shaft 13.

As shown in FIGS. 3 to 6, the engagement / disengagement mechanism 20 includes a vertical rod 21 and a bell-crank-shaped latch lever connected to and linked to a lower end of the rod 21.
22. The upper end of the rod 21 is swingably connected to the other side of the fulcrum of the sensor lever 14 via a pin 23, and the lower end is connected to the tip of the one-side extension 22A of the latch lever 22. Latch lever-22
Is rotatably supported by a pin 22B, and an engagement claw 22d is provided at a tip end of the other side extension 22D.

The rotation mechanism 30 is shown in FIGS. 3, 4, 7, and 8.
As shown in FIG. 9, the latch 31, the weight 32,
A striker 33 is provided. The latch 31 is fixed to one end of a shaft 34, and the shaft 34 is horizontally and rotatably supported by bearings 6, 6 provided on an upper portion of the cylinder base 5. Thereby, when the latch 31 rotates together with the shaft 34, the tip claw portion 31A has an
The latch lever 22 is detachably engaged with the engaging claw 22d. The weight 32 is fixed to the other end of the shaft 34 via a lever 35 extending obliquely upward. The striker 33 includes a pair of left and right arm portions 33A, 33A extending diagonally downward and facing each other, and a horizontal striking pin 33B connecting the lower ends of these arm portions 33A, 33A to each other. The upper ends of the arm portions 33A, 33A are fixed to the shaft 34 between the bearings 6, 6.

[0006] As shown in FIG.
It is constituted by a weight 42 attached to one end of the valve stem 3 via a lever 41. The link mechanism 50 is
As shown in FIGS. 3, 7, 9, and 10, a first link 51, a second link 52, and a lever 53 are provided. The distal end of the first link 51 is rotatably supported by a fixing member 55 via a horizontal pin 54, and the rear end is articulated to the distal end of the second link 52 via a horizontal pin 56. The rear end of the second link 52 is rotatably connected to the upper end of the lever 53 via a horizontal pin 57. Further, a positioning member 58 made of a bolt and a nut is attached so as to penetrate the first link 51 in the vertical direction, and a lower end of the positioning member 58 is
8A, the idea C of the link mechanism 50 is obtained.
The operation to the lower side (one side) is restricted within the limit. The lever 53 is fixed to the other end of the valve stem 3, and the lower end of the lever 53 is connected to the hydraulic cylinder 7 via a horizontal pin 59.
Are connected to each other. Further, a projection 53A is protruded from the lower end of the lever 53, and an opening pointer 53B is provided behind the projection 53A. The hydraulic cylinder 7 is connected to a cylinder base 5 through a horizontal trunnion 8 as shown in FIG.
The cylinder base 5 is swingably supported by a trunnion cover 5A which removably closes one opening of the cylinder base 5. In FIG. 4, reference numeral 17 denotes an upper stopper, 1
Reference numeral 8 denotes a lower stopper, each of which is a sensor lever-14.
Are provided corresponding to the vicinity of the balance weight 14. In FIG. 7, 9A and 9B indicate limit switches, 9C indicates an opening scale plate, and 9D indicates a stopper.
When the lever 53 rotates together with the valve stem 3, the limit switches 9A and 9B are used to move the elephant rotation locus R of the projection 53A.
The opening scale plate 9C is provided correspondingly to the
B is provided.

In the emergency shut-off valve configured as described above, in the region where the flow velocity of the passing water flow W shown in FIG. 4 is less than the set value, the weight ratio and the lever ratio of the balance weight 15 and the sensor weight 16 of the flow velocity detecting mechanism 10 are determined. As a result, the sensor lever 14 is held in the downward-rightward position shown by the solid line in contact with the upper stopper 17, and the flow sensor 11 is at the position shown by the solid line. Therefore, the latch lever 22 of the engagement / disengagement mechanism 20 is also held at the first position shown by the solid line, and the engagement claw 22d is the claw 31 of the latch 31 of the rotation mechanism 30.
A, and holds the valve body 2 of FIG. 3 in the valve open state in a substantially horizontal posture.

For example, when the downstream pipe 4B of the emergency shutoff valve is damaged due to the occurrence of an earthquake or the like and the flow rate of the passing water flow W shown in FIG. 4 exceeds a set value, the flow sensor 11 turns to the position indicated by the phantom line. As a result, the sensor lever 14 is held in a posture of rising to the right in contact with the lower stopper 18 as shown by a virtual line. As a result, the rod 21 of the engagement / disengagement mechanism 20 is pulled up, and the latch lever 22 is rotated clockwise to the second position indicated by the imaginary line, so that the engagement claw 22 d is rotated.
0 is retracted from the claw 31A of the latch 31. Engagement claw 22d of latch lever 22 and claw 31 of latch 31
When the engagement with A is released, the lever 35 and the shaft 34 (see FIG. 8) are indicated by phantom lines due to the weight of the weight 32 of the rotating mechanism 30 held at the position shown by the solid line in FIG. While rotating to the position shown, the striker 33 also rotates from the position shown by the broken line to the position shown by the virtual line.

[0009] By rotating the striker 33, FIG.
The striking pin 33B shown in (1) collides with the lower surface of the joint portion between the rear end of the first link 51 and the front end of the second link 52 in the link mechanism 50 and pushes up. As a result, the pin 56 moves upward (the other side) beyond the idea point C of the link mechanism 50. At that moment, the lever 41 and the valve rod 3 are rotated in the direction of arrow B by the closing torque of the weight 42 of the torque generating source 40 shown in FIG.
The valve 2 is rotated in the valve closing direction. When the valve element 2 starts to rotate in the valve closing direction, the dynamic pressure of the passing water flow W is applied to the valve element 2 to generate hydraulic torque in the valve closing direction. On the other hand, in a state before the lever 53 is rotated by its own weight of the weight 42, that is, in a position shown by a solid line in FIG. 7 and in a state where the projection 53A is in contact with the limit switch 9A, the hydraulic cylinder 7
The high-pressure oil in the front chamber is returned to an oil tank (not shown) through a return passage (not shown). Therefore,
With the rotation of the lever 53, the piston rod 7A of the hydraulic cylinder 7 advances, and the hydraulic cylinder 7
7 is tilted upward (forward) in FIG. 7 around the trunnion shaft 8 in FIG. By the operation of the hydraulic cylinder 7, the closing torque of the weight 42 due to its own weight,
Valve body 2 of FIG. 3 by hydraulic torque due to dynamic pressure of passing water flow W
The valve closing speed of the valve is adjusted to prevent the occurrence of the water hammer phenomenon, and the valve body 2 is closed in a substantially vertical posture so that water flows from the upstream pipe 4A to the downstream pipe 4B. Cut off. In this valve closed state, the lever 53 together with the valve stem 3
Is held by rotating and stopping from the position shown by the solid line to the position shown by the imaginary line abutting on the stopper 9D. When the lever 53 rotates to the position shown by the imaginary line in contact with the stopper 9D and stops, the protrusion 53
A contacts the limit switch 9B and the hydraulic cylinder 7
The high-pressure oil in the rear chamber is returned to an oil tank (not shown) through a return passage (not shown).

As described above, the conventional emergency shutoff valve can automatically shut off water flow in an emergency when the pipe 4B is damaged by an earthquake. On the other hand, the rotation start flow velocity at which the flow sensor 11 is rotated toward the position shown by the imaginary line in FIG. 4 can be set by the weight ratio and the lever ratio of the balance weight 15 and the sensor weight 16 of the flow velocity detection mechanism 10. It has become. That is, the rotation start flow velocity setting means is constituted by the sensor weight 16 of the flow velocity detection mechanism 10, and the rotation start flow velocity of the flow sensor 11 is set by the weight ratio and the lever ratio of the balance weight 15 and the sensor weight 16. By changing the lever ratio, the set value of the rotation start flow velocity of the flow sensor 11 can be changed stepwise.

[0011]

However, in the conventional flow velocity detecting mechanism, the sensor lever-1 can be slid and positioned.
Since the rotation start flow velocity setting means is constituted by the sensor weight 16 attached to the sensor weight 4, a long sensor lever is provided.
14 is required, and the product size increases. Further, the set value of the rotation start flow velocity of the flow sensor 11 can be changed only in steps, and there is a disadvantage that fine adjustment of the set value by stepless change is impossible. Therefore, the present invention
It is an object of the present invention to provide a flow rate detecting mechanism capable of finely adjusting the product size while keeping the product size small and changing the flow start flow rate of the flow sensor steplessly.

[0012]

In order to achieve the above object, a flow rate detecting mechanism according to the present invention comprises a flow sensor which projects inside a fluid passage and interferes with a passing fluid, and
A sensor shaft having a sensor fixed to the outside of the fluid passage and rotatably supported, a sensor lever having a fulcrum fixed to the sensor shaft, and a rotation start flow rate of the flow sensor. A rotation start flow rate setting means provided on the sensor lever, and a rod that moves following the rotation of the sensor lever is attached to the sensor lever, and operates following the movement of the rod. In the flow rate detecting mechanism having an engaging / disengaging mechanism connected to the rod, the rotation start flow rate setting means prevents the flow sensor from interfering with the passing fluid via the rod, the sensor lever, and the sensor shaft. And a spring force adjusting mechanism capable of steplessly adjusting the spring force of the spring.

According to the present invention, a long sensor lever is not required. In addition, the stepless adjustment of the spring force of the spring by the spring force adjusting mechanism enables fine adjustment of the set value of the flow start flow rate of the flow sensor.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a partial cross section of an embodiment of the present invention, and FIG. 2 is an enlarged cross sectional view taken along the line AA of FIG. The same or corresponding parts as those of the conventional emergency shutoff valve and the flow velocity detecting mechanism are denoted by the same reference numerals, and detailed description of the structure is omitted. 1 and 2, a flow rate detecting mechanism 10 includes a flow sensor 11 protruding into a valve box 1, a sensor shaft 13 horizontally and rotatably supported in a hood 12, and an outside of a hood 12. Sensor axis 1
3 has a fulcrum fixed to one end of the sensor lever 14 and a balance weight 15 fixed to one end of the fulcrum of the sensor lever 14, and the upper end of the flow sensor 11 is fixed to the sensor shaft 13. Have been. The other side of the fulcrum in the sensor lever 14 is formed to be short.

The rod 21 includes a connecting portion 21A, a lower portion 21B integrally provided below the connecting portion 21A, and an upper portion 21C integrally provided above the connecting portion 21A. 21 is a sensor lever-1 via a pin 23
4 is rotatably connected near the other end of the fulcrum, and the lower end of the lower body 21B is connected to the tip of one extension 22A of the latch lever 22. An external thread 21D is provided at the axial center of the upper body 21C, and a nut 21E is screwed to the external thread 21D. The upper end of the upper body portion 21C is supported by the support plate 12A so as to vertically move freely through the through hole 12a of the support plate 12A fixed to the hood 12, and a nut is provided between the support plate 12A and the nut 21E. A spring 60 is provided to urge the other end of the fulcrum of the rod 21 and the sensor lever 14 downward through the 21E.

That is, the rod 21 and the sensor lever 14
And a spring 60 that urges the flow sensor 11 against the interference of the passing water flow (passing fluid) W via the sensor shaft 13, a male screw portion 21D capable of continuously adjusting the spring force of the spring 60, and With a spring force adjusting mechanism composed of a nut 21E screwed into the male screw portion 21D,
The rotation start flow speed setting means of the flow sensor 11 is constituted.

With such a configuration, when the downstream pipe 4B of the emergency shut-off valve is damaged due to, for example, occurrence of an earthquake or the like, and the flow rate of the passing water flow W exceeds a set value, the flow sensor 11 is turned on as shown in FIG. The sensor lever 14 is rotated to the position indicated by the imaginary line, and the sensor lever 14 is held in an upward right position as indicated by the imaginary line. As a result, the rod 21 of the engagement / disengagement mechanism 20 is pulled up, and the latch lever 22 is rotated clockwise to the second position indicated by the imaginary line, and the engagement claw 22d is moved to the claw portion 31A of the latch 31 in the rotation mechanism 30. Evacuate from. When the engagement between the engagement claw 22d of the latch lever 22 and the claw portion 31A of the latch 31 is released, the valve body 2 of FIG. Can be shut off.

On the other hand, the rotation start flow rate at which the flow sensor 11 is rotated toward the position shown by the imaginary line in FIG. 1 is determined by rotating the nut 21 of the spring force adjusting mechanism and rotating the nut 21E and the support plate 12A. Steplessly changing the spring force of the spring 60 by increasing the interval to reduce the spring force of the spring 60, or reducing the interval between the nut 21E and the support plate 12A to increase the spring force of the spring 60. And fine-tuning is possible. In addition, since the long sensor lever 14 is not required, the product size can be significantly reduced.

[0019]

As described above, the present invention provides a spring that urges a flow sensor against the interference of a passing fluid through a rod, a sensor lever, and a sensor shaft, and a spring force of the spring. Since the rotation start flow velocity setting means is constituted by a spring force adjustment mechanism capable of stepless adjustment,
Long sensor levers are not required, and product dimensions can be significantly reduced. In addition, the flow start flow rate of the flow sensor can be changed steplessly and fine adjustment thereof is possible.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention in a partial cross section.

FIG. 2 is an enlarged sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view of an emergency shutoff valve.

FIG. 4 is an enlarged longitudinal side view showing a relationship between a flow velocity detection mechanism, an engagement / disengagement mechanism, and a rotation mechanism.

FIG. 5 is a sectional view taken along the line II in FIG. 4;

FIG. 6 is a cross-sectional view taken along the line wo in FIG. 4;

FIG. 7 is an enlarged side view showing the relationship between the rotation mechanism and the link mechanism.

FIG. 8 is a sectional view taken along the line AA of FIG. 7;

FIG. 9 is a longitudinal sectional side view showing the link mechanism in an enlarged manner.

FIG. 10 is a sectional view taken along the line O-O of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve case (fluid passage) 4A piping (fluid passage) 4B piping (fluid passage) 10 Flow velocity detecting mechanism 11 Flow sensor 13 Sensor shaft 14 Sensor lever 20 Disengagement mechanism 21 Rod 21D Male screw part 21E Nut W Passing water flow (passing fluid)

Claims (1)

[Claims] A flow sensor which projects inside the fluid passage and interferes with the passing fluid; a sensor shaft which is fixed to the outside of the fluid passage and is rotatably supported; A sensor lever having a fulcrum fixed to the sensor shaft,
A rotation start flow velocity setting means provided on the sensor lever for setting a flow start flow velocity of the flow sensor, and a rod that moves following the rotation of the sensor lever is attached to the sensor lever. The rotation start flow velocity setting means is provided via the rod, a sensor lever, and a sensor shaft. And a spring for urging the flow sensor against the interference of the passing fluid, and a spring force adjusting mechanism capable of steplessly adjusting the spring force of the spring.