JPH08285749A - External hydraulic test equipment for flexible synthetic resin tube - Google Patents

Abstract

PURPOSE: To obtain an equipment for carrying out external hydraulic test of a flexible synthetic resin tube under a state similar to the state applied with earth pressure by fixing the recessed outer circumferential surface of the resin tube closely to the recessed upper inner wall face of a container body. CONSTITUTION: A flexible synthetic resin tube 2 fixed, at the opposite ends thereof, with synthetic resin tubes 5 is contained in a container body 1. When the fixed end part 3 inserted with the resin tube 5 and each flange at the end 12 of the container body are secured hermetically, the recessed outer circumferential surface 21 of the flexible tube 2 being bent are fixed closely to the recessed inner wall face 13 of the body 1. It is the fixed to an external hydraulic pressure test equipment and an air vent valve 7 is opened by injecting 6 water. After the body 1 is filled with water, the valve 7 is closed and external hydraulic pressure test is carried out while applying a predetermined hydraulic pressure. The flexible tube 2 begins to deform hydraulically but since the outer circumferential surface 21 is fixed closely to the inner wall face 13, the deformation is blocked and the external hydraulic pressure test is carried out while sustaining a predetermined radius of curvature. Consequently, the test can be carried out under a state similar to the state where the flexible tube 2 is buried in the earth while being bent and applied with earth pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external water pressure test device for a synthetic resin flexible tube, and more particularly to an external water pressure test device suitable for performing an external water pressure test in a bent synthetic resin flexible tube. Regarding

[0002]

2. Description of the Related Art Conventionally, as a flexible tube made of synthetic resin, for example, it is known and described in Japanese Utility Model Publication No. 6-32540.
In this synthetic resin flexible tube, a plate-shaped body having an irregular cross section is spirally wound, and a convex portion provided on one side surface of the plate-shaped body and a concave portion provided on the other side surface thereof are fitted to each other. Are joined together to form a tubular body. The synthetic resin flexible tube exhibits flexibility due to the configuration of the fitting portion, and is used, for example, as a cable protection tube for protecting a power transmission cable.

Since the synthetic resin flexible tube used as the cable protection tube is used by being buried in the ground, earth pressure is applied to the outer peripheral surface of the synthetic resin flexible tube to be deformed. On this occasion,
Since there is a possibility that water will leak due to a gap being formed in the joint portion of the spirally wound plate-like body, it is tested beforehand by an external water pressure tester as a substitute test for earth pressure. At this time, the synthetic resin flexible tube is tested in a bent state with a constant radius of curvature so as to be the same as the actual use state.

Conventionally, in the external water pressure test of the above-mentioned synthetic resin flexible tube, a cylindrical container body having a bend, both ends of the synthetic resin flexible tube housed in the container body, and both ends of the container body. There is used an external water pressure testing device including a fixed end portion for sealing a gap between the fixed end portion and a pressurized water introduction port provided on a side wall of the container body between the fixed end portions. In the conventional external water pressure testing device, the synthetic resin flexible tube is bent and accommodated in a substantially central portion of the container body cross section, both ends of the synthetic resin flexible tube are sealed, and pressurized water is introduced from the pressurized water inlet. Then, water pressure is applied to the outer peripheral surface of the synthetic resin flexible tube for testing.

[0005]

However, when the above-mentioned conventional external water pressure testing device for a synthetic resin flexible tube is accommodated, for example, by bending the synthetic resin flexible tube horizontally to a predetermined curvature, the synthetic resin flexible tube is bent. The outside radius of curvature of the tube that is bent and convex is larger than the inside radius of curvature that is concave, so
The outer half of the synthetic resin flexible tube has a larger surface area than the inner half. Therefore, the flexible tube is deformed by being pushed by the water pressure in the direction from the outer side to the inner side of the flexible tube of the synthetic resin, so that the predetermined curvature cannot be maintained. Therefore, due to the local water pressure, the fitting portion of the convex outer peripheral surface is deformed, causing water leakage from the portion.

On the other hand, when it is buried in soil and subjected to earth pressure, unlike water, the soil does not have the property of freely flowing and deforming. Even if an extra force is applied by the difference, the curvature before burying does not change due to being blocked by the soil around the synthetic resin flexible tube. Therefore, there is a problem that an accurate test cannot be performed because the behavior is different between the case where the earth pressure is applied and the case where the outside water pressure is applied. The present invention has been made to solve the above problems,
An object of the present invention is to provide an external water pressure test device for a synthetic resin flexible tube, which is capable of performing an external water pressure test in a state similar to a state where it is buried in soil and subjected to earth pressure.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has a cylindrical container body having a bend and a synthetic resin flexible tube housed in the container body. Outside of the flexible tube made of synthetic resin, which comprises a fixed end portion for sealing a gap between both end portions of the container body and both end portions of the container body, and a pressurized water inlet provided on a side wall of the container body between the fixed end portions. A hydraulic testing device, characterized in that when a synthetic resin flexible tube is bent and accommodated in the container body, a concave outer peripheral surface of the synthetic resin flexible tube is attached in proximity to a concave inner wall surface of the container body. It is an external water pressure testing device for a synthetic resin flexible tube.

The synthetic resin flexible tube used in the present invention is a helix manufactured by spirally winding a plate-shaped body having an irregular cross section as described and known in Japanese Utility Model Publication No. 32540/1994. A pipe, or a spiral pipe manufactured by spirally winding a plate-shaped body made of steel plate coated with a synthetic resin, or a flexible pipe in which a pipe wall is bent in a bellows shape,
There is no particular limitation as long as it is a synthetic resin tube that can be easily bent.

[0009]

The external water pressure testing device for the synthetic resin flexible tube of the present invention is
When a synthetic resin flexible tube is bent and housed in a container body having a bend, the curved outer radius of curvature of the synthetic resin flexible tube is larger than the inner radius of curvature of the concave, so that The convex outer half of the resin flexible tube has a larger surface area than the concave inner half.

As a result, the synthetic resin flexible tube tends to be deformed by being pushed by the water pressure in the direction from the outside to the inside by the difference in surface area. The concave outer peripheral surface of the synthetic resin flexible tube is the concave inner wall surface of the container body. Since it is mounted in close proximity to, it is possible to perform external water pressure test while preventing deformation and maintaining a predetermined radius of curvature, and therefore, in a state similar to the state where it is buried in the soil and the soil pressure is applied. External water pressure test is possible.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is an embodiment of the external water pressure test apparatus of the present invention, in which (a) is a plan sectional view and (b) is a partially cutaway side view.

An embodiment of the present invention will be described with reference to FIG. Reference numeral 1 is a container body, 2 is a synthetic resin flexible tube, 3 is a fixed end portion, 4 is a pipe joint, 5 is a synthetic resin tube, and 6 is a pressurized water introducing port. The external water pressure testing device includes a container body 1, both fixed end portions 3 and 3, and a pressurized water introduction port 6.

The container body 1 comprises a container body central portion 11
And container body end portions 12, 12 provided at both ends of the container body central portion 11. Center part of container body 1
1 is a size 250 A stainless steel pipe (inner diameter 259.
4 mm) is bent at a radius of curvature of 1100 mm and a bend angle of 60 °. The container body end 12 is a stainless steel pipe having the same size as the container body center 11, and is eccentrically connected to both ends of the container body center 11.

At both ends of the container body 1, cylindrical fixed ends 3 and 3 are connected by flanges and attached, and ring-shaped grooves are provided in the inner peripheral surface of the fixed end 3. The sealing material 31 is fitted. A synthetic resin flexible tube 2 is housed in the container body 1. This synthetic resin flexible tube 2 is made of a hard vinyl chloride resin, and a plate-shaped body having an irregular cross section is spirally wound around the convex portion provided on one side surface of the plate-shaped body and the other side surface. The provided recesses are fitted and joined to each other to form a tubular body. The synthetic resin flexible tube 2 has a size of 150 A, and synthetic resin tubes 5 and 5 made of hard vinyl chloride are connected to both ends of the synthetic resin flexible tube 2 via joints 4 and 4. There is.

The synthetic resin pipes 5 and 5 are inserted and attached to the cylindrical fixed ends 3 and 3, and the gap between the fixed end 3 and the synthetic resin pipe 5 is sealed by the sealing material 31. There is. A pressurized water inlet 6 is provided below the side wall of the container body 1 and an openable / closable air vent valve 7 is provided above.

The synthetic resin flexible tube 2 to which the synthetic resin tubes 5 and 5 are connected is housed in the container body 1, and the synthetic resin tube 5 and
When 5 is inserted and fixed in the fixed ends 3 and 3, the synthetic resin flexible tube 2 is bent, and the concave outer peripheral surface 21 of the bent synthetic resin flexible tube 2 becomes the concave inner wall surface 13 of the container body 1. It is designed to be installed in close proximity. The container body 1 is attached to a pedestal 9 by legs 8 as shown in FIG.

Next, a method of using the external water pressure testing apparatus for the synthetic resin flexible tube 2 having the above-described structure will be described. First, one end of the synthetic resin flexible tube 2 is inserted into one end of the joint 4, and the gap between the outer peripheral surface of the end of the synthetic resin flexible tube 2 and the inner peripheral surface of the joint 4 is filled with a bonding agent. Install. Next, the synthetic resin pipe 5 coated with the bonding agent is inserted and attached to the other end of the joint 4. Similarly to the above, the joint 4 and the synthetic resin pipe 5 are attached to the other end of the synthetic resin flexible pipe 2.

As described above, the synthetic resin pipes 5 are provided at both ends.
The synthetic resin flexible tube 2 to which 5 is attached is housed in the container body 1, the synthetic resin tubes 5 and 5 are inserted into the fixed ends 3 and 3, and the flanges of the fixed ends 3 and 3 are attached to the container body end. Tighten with 12 flanges. Since the seal members 31, 31 are provided on the inner peripheral surfaces of the fixed ends 3, 3, the gap between the both ends of the synthetic resin flexible tube 2 and the both ends of the container body 1 is sealed. There is. When the synthetic resin flexible tube 2 is attached to the external water pressure testing device as described above, the pressurized water inlet 6
Water from the container, open the air vent valve 7 to remove air, fill the container body 1 with water, close the air vent valve 7 and maintain a predetermined water pressure for a predetermined number of days to perform an external water pressure test. To do.

(Operation of Embodiment) The synthetic resin flexible tube 2 of this embodiment is bent and accommodated in the container body 1. Since the outer radius of curvature of the synthetic resin flexible tube 2 that is bent and convex is larger than the inner radius of curvature that is concave, the convex outer half of the synthetic resin flexible tube 2 is more than the concave inner half. The surface area is large.

As a result, the synthetic resin flexible tube 2 tends to be deformed by being pushed by the hydraulic pressure in the direction from the convex outer side to the concave inner side due to the difference in surface area. Since it is mounted close to the concave inner wall surface 13 of the container body 1, the deformation can be prevented, and the external water pressure test can be performed in a state where a predetermined radius of curvature is maintained. Therefore, the external water pressure testing apparatus of the present embodiment is capable of performing an external water pressure test in a state similar to a state in which the synthetic resin flexible tube is bent and embedded in the soil, and earth pressure is applied.

[0021]

According to the external water pressure testing apparatus for a synthetic resin flexible tube of the present invention, since the concave outer peripheral surface of the synthetic resin flexible tube is close to the concave inner wall surface of the container main body, a predetermined pressure is always maintained during the water pressure test. Bending can be maintained, the performance of the synthetic resin flexible tube can be accurately evaluated, and external water pressure test data can be obtained in a state similar to the actual usage condition under earth pressure, which is highly reliable. .

In addition, the external water pressure testing apparatus for a synthetic resin flexible tube of the present invention does not require a special jig or the like to be attached in order to maintain the synthetic resin flexible tube as a test body in a predetermined bending state. However, since it is only necessary to insert it and store it, the operation becomes simple and the number of steps required for the test can be reduced.

[Brief description of drawings]

FIG. 1 is an example of an external water pressure test apparatus according to the present invention,
(A) is a plan sectional view, and (B) is a partially cutaway side view.

[Explanation of reference numerals] 1 container body 13 concave inner wall surface of container body 2 synthetic resin flexible tube 21 concave outer peripheral surface of synthetic resin flexible tube 3 fixed end 6 pressurized water inlet

Claims (1)

[Claims] 1. A tubular container body having a bend, and fixed ends for sealing a gap between both ends of a synthetic resin flexible tube housed in the container body and both ends of the container body. An external water pressure test device for a synthetic resin flexible tube consisting of a pressurized water inlet provided on the side wall of the container body between the fixed ends,
When the synthetic resin flexible tube is bent and accommodated in the container body,
An external water pressure testing device for a synthetic resin flexible tube, wherein the concave outer peripheral surface of the synthetic resin flexible tube is attached in proximity to the concave inner wall surface of the container body.