JPH05133482A - Directional control valve - Google Patents

Abstract

PURPOSE:To improve the extent of sealability by installing each of plural outflow ports, whose one end is projected into a valve box, radially in a valve box side with an inflow port, and setting up a passage, interconnecting a passage in the valve box and the outflow ports, in a rotary valve element coming into slidingly contact with the valve seat. CONSTITUTION:A controlled fluid 12 taken into a valve box 11 from an inflow port 13 passes through a valve element passage 20 of a rotary valve element 17 and then it is discharged to the outside of the valve box 11 from one of outflow ports 14. Another outflow port 14 is closed by the rotary valve element 1 7 coming into slidingly contact with a valve seat 15, and with rotation of the rotary valve element 17, an outlet side opening of the passage 20 is selected to the other outflow port 14 for directional control. Since a clearance between an inner surface wall of the valve box 11 and the rotary valve element 17 forms a part of a passage 19 in the valve box, the fluid 12 flows around those of rotary valve element 17, valve seat 15 and outflow ports 14, whereby each area coming into contact with the fluid 12 at the valve seat 15, the rotary valve element 17 and the outflow ports 14 is increased, thus each member is adapted to a temperature of the fluid 12 into uniformization. Therefore any thermal expansion difference is avoided and sealability is improvable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional control valve, and more particularly to a structure for reducing the influence of thermal strain when handling a high temperature fluid.

[0002]

2. Description of the Related Art As a conventional directional control valve, for example, FIG.
There is a 4-way 3-position switching valve as shown in FIG. In FIG. 3, the high temperature fluid 1 flows into the inside of the valve box 3 from the lower port 2 and flows out from any of the plurality of ports 5 provided on the side portion depending on the position of the rotary valve body 4. Therefore, the high temperature fluid 1 flowing in from the port 2 always flows out from any one of the ports 5.

[0003]

However, in the above-mentioned conventional structure, when the high temperature fluid 1 is flowing through the port 5, for example, the temperature of the valve seat 6 corresponding to the port 5 and the temperature of the valve box 3 in the vicinity thereof. Is increased, the temperature of the valve seat 3 in the closed valve seat 6 of the other port 5 and the vicinity thereof is decreased. Therefore, the vicinity of the port 5 in which the high temperature fluid 1 flows and the port 5 in which the high temperature fluid 1 does not flow
A problem that temperature nonuniformity becomes large between the vicinity and the valve seat 6 is deformed by thermal strain to impair the sealing performance in the closed port 5, and leakage from the closed port causes abnormal control. was there.

Further, since the valve housing 3 and the valve seat 6 are completely integrated, the valve seat 6 is directly affected by the distortion of the valve housing 3 due to the temperature difference. There was a problem. Further, the fact that the valve box 3 and the valve seat 6 are integrated is easily affected by the force transmitted from the outside such as piping, and the rotary valve body 4 and the valve seat 6 in the closed port 5 are easily affected.
There is a problem in that the sealing property with and is hindered or the operation is hindered.

The present invention solves the above problems, and suppresses the generation of thermal strain due to the non-uniformity of temperature to improve the sealing property between the valve body and the valve seat and smooth the operation. It is an object of the present invention to provide a designed directional control valve.

[0006]

In order to solve the above-mentioned problems, the directional control valve of the present invention is provided with a valve box having an inflow port for the fluid to be controlled on one side, and one end of the valve box has a side portion. A plurality of cylindrical outflow ports projecting into the valve box are radially provided, and a rotary valve body loosely fitted in the valve box is slidably contacted with a valve seat provided at the tip of the outflow port to be rotatable. The rotary valve body is provided with a valve body flow passage that connects the flow passage in the valve box and the outflow port.

Further, the rotary valve body is provided with a bypass flow passage for connecting the valve body flow passage and the flow passage in the valve box. In addition, a flexible portion that expands in the radial direction and that can expand and contract in the axial direction is formed in the middle of the outflow port.

[0008]

With the above structure, the controlled fluid that has flowed into the valve box from the inflow port flows out of the valve box through one outflow port through the valve body flow path of the rotary valve body. At this time, the other outflow port is closed by the outer peripheral surface of the rotary valve body that is in sliding contact with the valve seat, and the rotary valve body is rotated to switch the outlet side opening of the valve body flow path to the other outflow port. Direction control is performed.

Since the controlled fluid circulates around the rotary valve body and the outflow port in the valve box by providing an appropriate gap between the inner wall of the valve box and the rotary valve body, the valve box, The entire valve seat, rotary valve body and outflow port acclimate to the temperature of the controlled fluid. Therefore, even when a high-temperature fluid or the like is used as the controlled fluid, temperature non-uniformity does not occur in each part of the valve box, the rotary valve body, and the outflow port, and the influence of the strain due to the difference in thermal expansion is avoided. It is possible to always maintain a good sealability between the rotary valve body and the valve seat not only in the outflow port but also in the closed outflow port.

Further, the controlled fluid that circulates around the valve seat and the rotary valve body and around the outflow port in the valve box flows out to the valve body flow passage through the bypass flow passage provided in the rotary valve body. The controlled fluid is smoothly circulated in the valve box, and the metabolism of the controlled fluid in the valve box and the acclimation of the rotary valve element to the controlled fluid temperature are promoted. As a result, the sealability between the rotary valve body and the valve seat becomes better.

Further, when the valve box, the valve seat, and the outflow port are thermally expanded to generate a force pressing each other, the outflow port expands and contracts in the axial direction in the flexible portion to absorb the difference in thermal expansion between the respective members. Therefore, the influence of the strain due to the difference in thermal expansion is further avoided, and the sealability between the rotary valve body and the valve seat becomes better.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 2, an inflow port 13 for the controlled fluid 12 is formed at the bottom of the valve box 11.
A plurality of outflow ports 14 are radially provided on one side portion. The outflow port 14 is formed of a circular pipe, one end of which projects into the valve box 11, and one end side of each outflow port 14 is connected to integrally provide a tapered valve seat 15. .. For this reason, the valve seat 15 is located at a proper distance from the inner peripheral surface of the valve box 11.

The flexible portion 1 is provided in the middle of the outflow port 14.
6 is formed, and the flexible portion 16 has a shape that swells in the radial direction so that it can be expanded and contracted in the axial direction.

The rotary valve body 17 is provided inside the valve box 11.
Is provided so that its outer peripheral surface is in sliding contact with the valve seat 15 and is rotatable about the axis of the valve seat 15, and the rotary valve body 17 is connected and supported by the valve rod 18. Further, the rotary valve body 17 is formed with a valve body flow passage 20 that connects the flow passage 19 inside the valve box and the outflow port 14, and a plurality of flow passages that connect the flow passage 20 inside the valve box and the flow passage 19 inside the valve box. The bypass channel 21 is formed.

The operation of the above structure will be described below.
The controlled fluid 12 that has flowed into the valve box 11 from the inflow port 13 flows out of the valve box 11 from one outflow port 14 through the valve body flow path 20 of the rotary valve body 17. At this time, the other outflow port 14 is closed by the outer peripheral surface of the rotary valve body 17 that is in sliding contact with the valve seat 15, and the rotary valve body 17 is rotated by the rotational driving of the valve rod 18 to rotate the rotary valve body 17. Direction control is performed by switching the outlet side opening to another outflow port 14.

The inner wall of the valve box 11 and the rotary valve body 17
Since an appropriate gap formed between the two forms a part of the flow path 19 inside the valve box, the inside of the valve box 11 is covered around the rotary valve body 17, the valve seat 15, and the outflow port 14. Since the control fluid 12 circulates, the area of the valve box 11, the valve seat 15, the rotary valve body 17, and the outflow port 14 in contact with the controlled fluid 12 increases, so that the temperature of the controlled fluid 12 as a whole of each member is controlled. To homogenize. Therefore, even when a high temperature fluid or the like is used as the controlled fluid 12, temperature non-uniformity does not occur in each part of the valve box 11, the valve seat 15, the rotary valve body 17, and the outflow port 14, and a difference in thermal expansion is caused. The influence of distortion is avoided, and good sealing performance between the rotary valve body 17 and the valve seat 15 can be always maintained not only in the open outflow port 14 but also in the closed outflow port 14.

Further, inside the valve box 11, the rotary valve body 1
The controlled fluid 12 circulating around 7 and around the outflow port 14 flows out to the valve body passage 20 through the bypass passage 21 provided in the rotary valve body 17 to control the controlled fluid inside the valve box 11. The fluid 12 is smoothly circulated, and the valve box 1
The metabolism of the controlled fluid 12 inside 1 and the acclimation of the rotary valve body 17 to the controlled fluid temperature are promoted. For this reason, the temperature in the flow path 19 in the valve box is made uniform, and the sealability between the rotary valve body 17 and the valve seat 15 becomes better.

Further, when the valve box 11, the rotary valve body 17 and the outflow port 14 are thermally expanded and a force for pressing each other is generated, the outflow port 14 expands and contracts in the axial direction in the flexible portion 16 and the respective members of the members are expanded. Since the difference in thermal expansion is absorbed, the influence of strain due to the difference in thermal expansion is further avoided, and the sealing performance between the rotary valve body 17 and the valve seat 15 becomes better.

[0019]

As described above, according to the present invention, the controlled fluid circulates around the rotary valve body and the outflow port in the valve box, and each member is acclimated to the temperature of the controlled fluid. Therefore, temperature non-uniformity does not occur in each part of the valve box, rotary valve body and outflow port, and the effect of strain due to the difference in thermal expansion is avoided to maintain good sealing performance between the rotary valve body and valve seat. can do.

Further, since the controlled fluid passes through the bypass passage provided in the rotary valve body, the controlled fluid is smoothly circulated in the valve box, and the acclimation to the controlled fluid temperature is promoted to rotate the controlled fluid. The sealability between the valve body and the valve seat becomes better.

Further, since the outflow port expands and contracts in the axial direction in the flexible portion to absorb the difference in thermal expansion between the respective members, the influence of strain due to the difference in thermal expansion can be further avoided, and the rotary valve body and the valve seat can be prevented. Will have better sealing properties.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a directional control valve according to an embodiment of the present invention.

2 is a plan sectional view taken along the line AA in FIG.

FIG. 3 is a vertical cross-sectional view of a conventional directional control valve.

[Explanation of symbols]

 11 valve box 12 controlled fluid 14 outflow port 16 flexible part 19 valve box internal flow path 20 valve body flow path 21 bypass flow path

Front page continuation (72) Inventor Keiichi Yanase 1-1-1, Nakanomiya Oike, Hirakata City, Osaka Prefecture Kubota Hirakata Manufacturing Company

Claims (3)

[Claims] 1. A valve box having an inflow port for a controlled fluid is provided on one side, and a plurality of cylindrical outflow ports are radially provided at a side portion of the valve box, one end of which projects into the valve box. A rotary valve element that is loosely fitted in the valve box is rotatably provided in sliding contact with a valve seat provided at the tip of the outflow port, and a valve that connects the flow path in the valve box and the outflow port to this rotary valve element. A directional control valve having a body passage. 2. The rotary valve body is provided with a bypass flow passage that connects the valve body flow passage and the flow passage in the valve box.
Directional switching valve described. 3. The directional control valve according to claim 1, wherein a flexible portion swelling in a radial direction is formed in the middle of the outflow port to allow expansion and contraction in the axial direction.