JPS5949456B2 - pinch valve device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pinch valve mainly used as a channel opening/closing device.

Conventionally, pinch pulp has been used as a simple valve mainly for experimental and medical purposes.

The conventional type mentioned above is a rubber tube as shown in FIG.

A flexible tube such as a synthetic resin tube is clamped and the inner wall surfaces thereof are brought into pressure contact with each other to block a flow path.

However, when looking at the pinching part of this pinch valve in detail, the bending conditions at both ends of the bending parts 2, 2 are severe, and when this part is enlarged, there is a minute cavity 1 in the bending part as shown in FIG. is completed.

It is difficult to eliminate the void space with a light squeezing force, and a reliable flow path blocking state is achieved only when a squeezing force is applied to the extent that the void space 1 is crushed.

However, if this state is maintained for a long period of time, or if the clamping and releasing of the clamping portions, that is, the opening and closing operations are repeated for a long period of time, permanent deformation or cracks occur in the bent portions 2, 2.

In this respect, it has the disadvantage of lower durability than other lift valves.

Therefore, at present, this type of pinch valve is normally used only in applications where a small amount of leakage is allowed in a low-pressure flow path.

On the other hand, flexible tubes with a special cross-sectional shape,
For example, German Patent No. 88441 (Figures 3 and 4)
, a pinch valve in which a pair of ribs with a cross section matching the bent portions 2, 2 is provided parallel to the inner surface of the tube wall, for example, the one in German Patent No. 2220860 (FIG. 5), is known. Although the drawbacks have been alleviated to some extent, they have not basically been resolved, and in the process leading up to the state where the flow path is blocked, the flexible tube is pinched in such a way as to crush the void 1 that has been created. must be pressed.

The present invention is designed to prevent extreme deformation of the bent portion in the flow W15 cutoff state in this type of pinch pulp.
The objective is to ensure that a flow path is blocked even if a minute void is created in the bent portion.

The technical means of the present invention to solve the above-mentioned problems is to make a rib annularly protrude in the tube wall, so that the surface of the rib is oblique with respect to the center line of the flexible tube, and the rib cross section is The joint portion (root portion of the rib) with the tube wall is made into a thin wall portion, and the flexible tube is compressed from above and below the constituting surface of the rib.

According to the above technical means of the present invention, the following effects can be obtained.

The virtual surface formed by the annular rib protruding from the inner wall of the flexible tube obliquely blocks the flow path inside the flexible tube, and when the valve is open, the through hole formed by the inner peripheral edge of the annular rib obliquely blocks the flow path inside the flexible tube. serves as a distribution channel.

From this state, when the rib-arranged area of the flexible tube is compressed, the tube walls located above and below the annular rib come into close contact with the entire area of the rib.

At this time, the flow path formed within the flexible tube, that is, the through hole formed by the inner peripheral edge of the rib, is closed by the upper and lower tube walls, and the flow path within the flexible tube is reliably blocked.

In this state where the flow path is blocked, a certain amount of space is created above and below the base of the rib at the bending part, that is, above and below the joint between the rib and the pipe wall, as in the past, but these spaces are It is blocked by an annular rib and is not in communication state.

Therefore, the flow path within the flexible tube can be reliably blocked despite the occurrence of voids, and the wall of the flexible tube is less likely to be cracked or permanently deformed even after long-term use, improving durability.

The present invention has the following unique effects.

(2) Since a reliable state of blocking the flow path can be obtained even when a void is created, the clamping pressure can be reduced accordingly.

2) In particular, since the joint between the cross section of the rib and the pipe wall is a thin wall part, when the flexible pipe is compressed, the tip side of the rib may come into contact with the pipe wall near the rib. At this time, the size of the void formed on the outside of the contact area increases, and the bending resistance of the base of the rib, that is, the root of the rib at the bending part of the tube wall when the tube wall is bent, increases. Therefore, the pipe wall tends to bend in this area.

Therefore, the clamping force exerted by the clamping member at the time of blocking the flow path can be further reduced.

Furthermore, for the same reason, durability is further improved.

3) Since the ribs are provided diagonally to the direction of flow in the flexible tube, compared to conventional ones in which the ribs are provided at right angles to the direction of flow, as shown in Figures 3 and 4. The cross-sectional reduction rate due to the ribs is reduced, and the increase in passage resistance due to the ribs is suppressed to a low level.

On the other hand, since it is a flexible tube partially provided with ribs,
Compared to the conventional example shown in FIG. 5 in which ribs are provided over the entire area of the flexible tube in the direction of flow, the overall increase in passage resistance can be suppressed to a low level.

4) The opening (flow path) formed by the tip of the rib is doubly blocked by the upper and lower pipe walls, which further improves the sealing effect when the valve is closed, and prevents dirt from adhering to one side of the rib. No leakage occurs.

Hereinafter, details of embodiments of the present invention will be described based on the drawings.

The flexible tube 3 used in the pinch valve of this embodiment has a structure shown in FIGS. 6 and 7, and has ribs 4 on the inner wall surface of the flexible tube.
are integrally formed, and this rib has a closed annular shape as a whole.

Further, the cross section of the rib 4 consists of a round cross section 5 on the tip side and a thin wall section 6 connecting this with the tube wall, and furthermore, the temporary surface including the rib 4 in the cross section is 3 is cut off diagonally from top to bottom.

When the ribbed area of the flexible tube 3 is compressed from above and below by the pressing members 7, it is flattened into the state shown in FIGS. 8 and 9, and the flow path is blocked.

At this time, the pipe wall of the flexible tube 3 is pressed against the upper and lower sides of the round cross-sectional view 5 of the rib 4 due to the clamping pressure, and the flow path of the rib attached part, that is, the inner periphery of the round cross-sectional part 5. An opening 8 formed in the tube is closed from above and below by the tube wall, thereby blocking the opening.

At this time, voids 1, 1 are created on the outside of the round cross-section portion 5, that is, on the top and bottom 1 of the thin wall portion 6, but these voids are closed in plan and are voids that continue to the upstream channel 9. The space 1a wraps around the upper part of the thin wall part 6 of the rib 4 and returns to the upstream flow path, and the other space 1a
Similarly, b is in a state where it communicates only with the downstream flow path 10,
The flow path within the flexible tube will be doubly blocked.

In addition, as shown in FIG. 10, a projection 11. is provided at the center of the clamping portion of the flexible tube.
11, and on the other hand, if a recess into which the projection fits is formed in the center of the clamping members 7, 7, the relationship between the clamping members 7, 7 and the rib 4 will correspond accurately.

Rubber, soft synthetic resin, etc. are usually used as the constituent material of the flexible tube, but it is also possible to incorporate various fiber materials in order to increase the pressure resistance.

[Brief explanation of drawings]

Figures 1 and 2 are explanatory diagrams of the conventional example, and Figures 3 to 5 are explanatory diagrams of other conventional examples.
The figure is a cross-sectional view of a main part of a flexible tube used in an embodiment of the present invention.
8 is a sectional view of the flexible tube in a compressed state, FIG. 9 is a Y-X sectional view, and FIG. 10 is a perspective view of another embodiment. ...flexible tube, 4...rib, 5.
. . . Round cross section, 6. Thin wall portion, 7. Pressure member.

Claims (1)

[Claims] 1. A rib is annularly protruded from the inner wall surface of the flexible tube, and the constituting surface of the rib crosses the center line of the flexible tube obliquely, and the joint part with the tube wall in the cross section of the rib is A pinch valve device having a thin wall portion and pinching a flexible tube from above and below the rib-forming surface.