JP2549085Y2 - Switching valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching valve, and more particularly, to a switching valve configured to simplify pipe connection.

[0002]

2. Description of the Related Art For example, in a hydraulic control unit for driving a control rod used in a nuclear power plant or the like, a cooling feed pipe for cooling a seal portion of a control rod driving mechanism separately from a pipe for operating a scrum. And a drive water supply pipe for supplying a predetermined amount of water for forcibly driving the control rod at the time of periodic inspection.

[0003] An opening / closing valve is provided in the driving water supply pipe, and is usually closed. On the other hand, the cooling water supply pipe is provided independently of the drive water supply pipe in a bypass manner, and a fixed orifice is provided on the way to supply a small amount of cooling water to the seal portion. It has become. This is because the control rod drive mechanism includes a piston and a cylinder, and heat from the nuclear reactor is transmitted to a seal member adhered to the outer periphery of the piston.

That is, when the seal member expands, the piston becomes inoperable. Therefore, a small amount of water is usually supplied to the cylinder to cool the seal member. The water supplied into the cylinder circulates between the cylinder and the seal. The on-off valve is opened at the time of periodic inspection. Confirm that the piston for driving the control rod operates by supplying a large amount of water to the cylinder by opening the on-off valve.

[0005] This type of on-off valve is operated by the operation of the valve element.
The outlet of the inflow passage and the entrance of the outflow passage that open to one side of the room
It opens and closes at the same time.
The outlet of the inflow path and the entrance of the outflow path immediately communicate with each other and are fully open
Control rod drive mechanism that can instantly supply a large amount of water
Of the cylinder.

[0006]

However, in the case of the conventional technique described above, since the cooling water supply pipe and the driving water supply pipe must be provided independently in the on-off valve, the piping path becomes complicated and the piping connection becomes troublesome. In addition, there is a problem that a fixed orifice must be provided in the middle of the cooling water supply pipe, and the processing at that time is troublesome.

When the fixed orifice is provided in the cooling water supply pipe, the flow rate to the cooling water supply pipe is determined by the upstream pressure, and the flow rate is adjusted so that an arbitrary flow rate according to the installation location flows. There is also a problem that it cannot be done. Then, this invention aims at providing the switching valve which solved the said subject.

[0008]

According to the present invention, there is provided an inflow passage through which a fluid flows into a valve body, an outflow passage through which the fluid flows, and an inflow passage.
And a valve body chamber communicating with the outflow passage, wherein the valve body chamber has
An opening on one side of the valve body chamber by the operation of the provided valve body
A switching valve that opens and closes an outlet of an inflow passage and an inlet of an outflow passage, wherein the valve body is interposed between the inflow passage and the outflow passage.
The valve body is provided with a bypass flow path that communicates with the valve body, and the bypass flow path is provided with flow rate adjusting means for adjusting a flow rate flowing through the bypass flow path.

[0009]

According to the present invention, since the bypass passage is provided for communicating the inflow passage and the outflow passage without passing through the valve body chamber ,
When the valve element closes the valve seat of the valve body, the fluid is supplied to the outflow path through the bypass flow path, and the flow rate of the bypass flow path can be adjusted to a desired flow rate by the flow rate adjusting means. In addition, the flow rate flowing in the bypass
Is adjusted so that the primary pressure of the inflow channel is
The primary pressure is introduced into the valve chamber where the valve slides.
Not to be entered. Therefore, the fluid in the inflow channel
Even if oil flows through the bypass channel to the outflow channel, the valve
Has no effect.

[0010]

1 and 2 show an embodiment of a switching valve according to the present invention. In both figures, a switching valve 1 is provided, for example, in the middle of a driving water supply pipe for supplying driving water to a cylinder (not shown) of a control rod driving mechanism for driving a control rod in nuclear power generation and checking the movement of a piston. This is an electromagnetic switching valve provided.

The switching valve 1 includes a valve body 2, a valve body 3 inserted into a sliding hole 2 a of the valve body 2, a solenoid assembly 4 mounted on an upper portion of the valve body 2, and a flow control valve. 8 The valve body 2 has a valve seat 2b at the back of the sliding hole 2a, an inflow passage 2c communicating the bottom with the sliding hole 2a, and an outflow passage 2d communicating the bottom with the valve seat 2b. The switching valve 1 is
One side of the sliding hole 2a as a valve chamber due to the operation of the valve 3
The outlet of the inlet 2c and the inlet of the outlet 2d are
The valve body 3 opens and closes when the valve body 3 opens.
The outlet of the inflow channel 2c and the inlet of the outflow channel 2d immediately communicate with each other.
Te can be fully opened, instantly control a large amount of water rod
It can be supplied to the cylinder of the drive mechanism.
ing.

The valve body 2 is fixed to, for example, a bracket 6 (shown by a dashed line in FIG. 1) of a water pressure control unit (not shown) by bolts 5, and the driving water is supplied to the inflow passage 2c
From the valve seat 2b to the outflow passage 2d.
Flows out to a driving water supply pipe (not shown) through The valve body 2 has an inflow passage 2c as a valve body chamber without passing through the sliding hole 2a.
And a bypass passage 7 communicating the outlet passage 2d with the outlet passage 2d. This bypass passage 7 has a bypass passage 7
There is provided a flow control valve (flow control means) 8 for adjusting the flow rate flowing through. That is, a small-diameter orifice hole 7a is provided on the inflow path 2c side of the bypass flow path 7, and the distal end 9a of the valve shaft 9 is inserted into the outflow path 2d side of the bypass flow path 7.

The valve shaft 9 extends into the bypass flow passage 7 from the screw portion 9b screwed into a hole 26 formed in the side surface of the valve body 2 and from the screw portion 9b across the outflow passage 2d. It has a rod 9c and an engaging portion 9d protruding on the side surface of the valve body 2. Therefore, the valve shaft 9 moves in the X direction by rotating the engaging portion 9d by a tool, and changes the flow rate flowing through the bypass flow path 7. Then, the bypass flow is controlled by the flow control valve 8.
By adjusting the flow rate flowing through the passage 7, the inflow passage 2c
Is introduced into the outflow passage 2d, but the valve body 3 slides.
The primary pressure is not introduced into the sliding hole 2a.
ing. Therefore, the fluid in the inflow channel 2c is
Flow to the outflow passage 2d via the valve will affect the operation of the valve body 3.
I can't get it.

An O-ring 27 for sealing between the valve shaft 9 and the hole 26 is mounted on the outer periphery of the end of the screw portion 9b. Further, the valve shaft 9 is fixed by tightening a lock nut 28 screwed into the screw portion 9b. Since the distal end portion 9a is formed in a tapered shape, the distal end portion 9a is inserted into the orifice hole 7a of the bypass flow passage 7, and the opening area of the orifice hole 7a is adjusted by turning the valve shaft 9 to thereby reduce the bypass flow. The degree of narrowing of the road 7 is changed. Further, the rod 9c has a small diameter so as not to obstruct the flow of the outflow passage 2d as much as possible.

As will be described later, when the valve element 3 closes the valve seat 2b, part of the driving water is used as cooling water as bypass water.
Flows through the gap between the orifice hole 7a and the tip 9a into the outflow passage 2d, and circulates through a driving water supply pipe (not shown). Therefore, there is no need to separately install a cooling water supply pipe having a fixed orifice unlike the conventional switching valve, and the number of parts is reduced and the mounting operation is facilitated.

As shown in FIG. 3, the valve body 3 has a valve seat 2 at the bottom.
b, and has a seat surface 3b at the upper portion that contacts the plunger 12 of the solenoid assembly 4. A first pilot hole 3c penetrating the center of the valve body 3 is opened at the bottom of the valve body 3 and at the center of the seat surface 3b. Is provided with a second pilot hole 3d. Also, valve element 3
O-ring 3e for sealing between the sliding hole 2a and the outer periphery
Is installed.

The solenoid assembly 4 includes a solenoid 10 around which a coil is wound, and a cover 11 that covers the solenoid 10.
And a plunger 12 slidably provided in the solenoid 10, and a cylindrical sleeve 13 screwed to the valve body 2 to guide the plunger 12. The plunger 12 has a central hole 12a into which a coil spring 14 fits,
A seat member (made of, for example, rubber, synthetic resin, or the like) 15 that is in contact with the seat surface 3b of the valve body 3 is embedded in the lower portion.

Reference numeral 16 denotes a coil spring provided between the valve body 3 and the plunger 12, the upper end of which is locked by a constricted portion at the lower end of the plunger 12, and the lower end of which is locked by a locking groove of the valve body 3. I have. The lower end surface of the sleeve 13 compresses the O-ring 17, and the annular stopper 18 is pressed and held by the step 2 e of the main body 2 via the O-ring 17. As shown in FIG. 2, the flow rate adjusting mechanism 20 for adjusting the flow rate of the outflow passage 2d is attached to the side surface of the main body 2, and reduces the flow rate by reducing the flow area of the outflow passage 2d downstream of the valve seat 2b. adjust. That is, the flow regulating mechanism 20 is provided with a throttle valve element 21 slidably inserted into a throttle hole 2f intersecting with the outflow passage 2d.
, A holder 22 into which the valve body 21 is screwed, an O-ring 23 for sealing between the valve body 21 and the hole 2 e, a lock nut 24 to be screwed into a screw portion of the valve body 21, and a screw of the holder 22. And a cap 25 which is screwed into the portion.

Therefore, when adjusting the flow rate, the cap 2
After the nut 5 is removed and the lock nut 24 is loosened, the end of the valve body 21 is turned with a tool such as a spanner. Here, the switching operation of the switching valve 1 configured as described above will be described. The switching valve 1 is normally closed, and is opened at the time of periodic inspection described later.
However, since the seal member (not shown) of the piston of the control rod drive mechanism is heated, water as cooling water is supplied to the inflow passage 2.
c, flows into the bypass flow path 7, reaches the outflow path 2d, and is supplied to the cylinder (not shown) of the control rod drive mechanism via the driving water supply pipe (not shown). At this time, the flow rate of the supplied cooling water is adjusted by the flow passage area of the orifice hole 7a of the bypass flow passage 7 in the switching valve 1. Bypass channel 7
Since the flow rate varies depending on the magnitude of the fluid pressure on the inflow side 2c, for example, merely providing a fixed orifice in the bypass flow path 7 varies the fluid pressure depending on the location where the switching valve 1 is mounted. There is a disadvantage that the flow rate of the passage 7 increases and the flow rate of the bypass flow path 7 decreases in a place where the pressure is low.

In this embodiment, however, by turning the valve shaft 9 of the flow control valve 8 shown in FIG.
Can be adjusted so that the flow rate of the bypass flow path 7a becomes a desired flow rate. Therefore, the water as the cooling water circulates through the drive water supply pipe through the bypass channel 7. As shown in FIG. 1, the seat member 3a of the valve body 3
Is in contact with the valve seat 2b and closes the valve seat 2b, the pressure of the water supplied from the inflow passage 2c is
Acts on the pilot chamber 19 above the valve body 3 via d.
Further, the plunger 12 is moved downward by the pressing force of the coil spring 14, and the seat member 15 is in contact with the seat surface 3 b above the valve body 3. Therefore, when the valve is closed, the valve body 3 is pressed by the valve seat 2b by the pressure of the water and the pressing force of the spring 14, and is held at the valve closing position.

Here, when periodic inspection of the control rod drive mechanism is performed, a drive current is supplied to the solenoid 10. That is, as shown in FIG. 3, when the solenoid 10 is energized, the plunger 12 is moved upward by its electromagnetic force. As a result, since the sheet member 15 of the plunger 12 is separated from the seat surface 3b, the pressure in the pilot chamber 19 is supplied to the outflow passage 2d through the first pilot hole 3c. Therefore, the pressing force pressing the valve body 3 against the valve seat 2b is weakened, and the valve body 3
Moves upward by the pressure of the driving water supplied from the inflow passage 2c and the tensile force of the spring 16. As shown in FIG. 4, the valve body 3 moves upward to a position where it comes into contact with the stopper 18 and separates from the valve seat 2b.

Thus, the cooling water flowing into the sliding hole 2a from the inflow passage 2c flows out from the valve seat 2b to the outflow passage 2d. Due to the valve opening operation of the valve element 3, a part of the driving water from the inflow path 2c flows through the bypass flow path 7 to the outflow path 2d as described above, but most of the driving water flows through the valve seat 2b to the outflow path 2d. The water is further supplied to the driving water supply pipe. Therefore, a large amount of drive water is supplied to the cylinder of the control rod drive mechanism, and the piston operates.

The closing operation of the switching valve 1 is performed by the solenoid 1
This is performed by turning off the current supply to zero. That is, as shown in FIG. 5, when the solenoid 10 is demagnetized, the plunger 12
Is moved downward by the pressing force of the spring 14, and the seat member 15 contacts the seat surface 3b of the valve body 3. Therefore, the first pilot hole 3c of the valve body 3 is shut off. As a result, the pressure in the pilot chamber 19 above the valve body 3 rises through the second pilot hole 3d, and the valve body 3
And the pressing force of the springs 14 and 16 moves down in the sliding hole 2a and sits on the valve seat 2b. Therefore, the valve element 3 returns to the valve closed state shown in FIG.

FIG. 6 shows a modification of the present invention. In the figure, the valve shaft 9 has first and second tapered portions 29 and 30 at the distal end. The first tapered portion 29 is inserted into the orifice hole 7a and has a shape having a small diameter at the tip end, and the second tapered portion 30 extends across the outflow passage 2d and has a taper opposite to the first tapered portion 29. The shape is such that the base end has a small diameter.

[0025] Therefore, when the valve stem 9 is moved in the X ₁ direction, the first tapered portion 29 is inserted into the orifice 7a, the large diameter portion part of the second tapered portion 30 is bypassed from the outlet passage 2d Displaced in the flow path 7. As a result, the flow rate of the bypass flow path 7 decreases, and the flow rate of the outflow path 2d increases. Further, the valve shaft 9 is moved in the X ₂ direction, the with the first tapered portion 29 is spaced apart from the orifice 7a 2
Is displaced into the outflow passage 2d.
Therefore, the flow rate of the bypass flow path 7 increases, and the flow rate of the outflow path 2d decreases.

Therefore, by turning the valve shaft 9, the flow rate of the bypass flow path 7 and the flow rate of the outflow path 2d can be adjusted so as to be simultaneously increased and decreased, and the flow rate adjusting mechanism 20 of the outflow path 2d can be eliminated. . FIG. 7 shows another modification of the present invention. In the figure, the valve shaft 9 has a first tapered portion 31 at the tip, and a second tapered portion 3 is provided between the screw portion 9b and the rod 9c.
2 The first tapered portion 31 has a tapered shape with a small diameter on the tip end side, and is inserted into the orifice hole 7a.
The second tapered portion 32 also has a tapered shape in which the distal end has a small diameter.

[0027] Therefore, when the valve stem 9 is moved in the X ₁ direction, the first tapered portion 31 is inserted into the orifice 7a, the large diameter portion of the second tapered portion 32 is displaced into the outlet passage 2d I do. As a result, the flow rates of the bypass channel 7 and the outflow channel 2d decrease. Further, the valve shaft 9 when moving in direction X _2, together with the first tapered portion 31 is spaced apart from the orifice 7a is smaller diameter portion of the second tapered portion 32 is displaced into outlet passage 2d. Therefore, the flow rates of the bypass channel 7 and the outflow channel 2d increase. In this case, by turning the valve shaft 9, the flow rate of the bypass flow path 7 and the flow rate of the outflow path 2d can be adjusted so as to decrease or increase at the same time, and the flow rate adjusting mechanism 20 of the outflow path 2d is unnecessary.

In the above embodiment, the control rod drive mechanism of the water pressure control unit is described as being periodically inspected and cooled. However, only an example is given here. Of course, 1 may be provided. Although the switching operation is performed by the electromagnetic force of the solenoid 10 in the above-described embodiment, the present invention is not limited to this, and the valve body may be driven using another type, for example, pneumatic or hydraulic pressure.

[0029]

As described above, the switching valve according to the present invention is a valve
Since the valve body has a bypass passage communicating the inflow passage and the outflow passage without passing through the body chamber , for example, in a water pressure control unit, driving water and cooling water for cooling the seal portion of the piston for periodic inspection are provided. The feed can be performed by one pipe route, the pipe route can be simplified, and the pipe connection work can be easily performed. In addition, since there is no need to provide a fixed orifice in the middle of another pipe and only a bypass is provided in the valve body, the number of parts is reduced, the mounting space is smaller, and a large number of devices are densely provided. Can also be attached.

The flow regulating valve flows through the bypass passage.
The primary pressure in the inflow channel is adjusted by adjusting the
It is introduced into the outflow passage, but the primary
No pressure is introduced. Therefore, inflow
Even if the fluid in the channel flows through the bypass channel to the outlet channel, the valve
It does not affect the operation of. In addition, since the flow rate adjusting means is provided in the bypass flow path, even if the pressure on the inflow side fluctuates, the flow rate flowing to the outflow side via the bypass flow path is adjusted, and a desired flow rate characteristic is obtained regardless of the conditions on the inflow side. It has such features that it can secure

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a switching valve according to the present invention.

FIG. 2 is a partial cross-sectional view showing a flow rate adjusting mechanism of an outflow passage.

FIG. 3 is an enlarged longitudinal sectional view of a main part for explaining a valve opening operation.

FIG. 4 is an enlarged vertical sectional view of a main part for explaining a valve opening operation of a valve body.

FIG. 5 is an enlarged vertical sectional view of a main part for explaining a valve opening operation of a valve body.

FIG. 6 is a longitudinal sectional view for explaining a modification of the present invention.

FIG. 7 is a longitudinal sectional view for explaining another modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switching valve 2 Valve body 2c Inflow path 2d Outflow path 3 Valve 4 Solenoid assembly 7 Bypass flow path 8 Flow control valve 9 Valve shaft 29,31 First taper part 30,32 Second taper part

Claims (1)

(57) [Scope of request for utility model registration] An inflow passage into which fluid flows into a valve body, an outflow passage through which the fluid flows, and a valve body communicating with the inflow passage and the outflow passage.
And a valve body provided in the valve body chamber.
Of the inflow passage opening to one side of the valve body chamber and outflow
In a switching valve that opens and closes an inlet of a passage, a bypass passage that communicates between the inflow passage and the outflow passage without passing through the valve body chamber is provided in the valve body, and the bypass passage flows through the bypass passage. A switching valve provided with flow rate adjusting means for adjusting a flow rate.