JPH0546475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a flexible hose for use in vacuum cleaners that has excellent repeated bending durability and has a long life.

Structure of conventional example and its problems Conventionally, in this type of flexible hose, while winding a tube having a chevron-shaped protrusion as shown in Fig. 3, It has a structure in which the joints are joined at the folds, and there were no particular positional restrictions on the joint structure.

Therefore, as shown in Figure 2, if the joints are connected securely with no steps between each other, there will be no problem with the life of the hose, but as shown in Figure 6, differences in steps may occur due to manufacturing process variations. If a crease is formed in the valley, when the hose is repeatedly bent, it will bend from this stepped part, stress concentration will occur due to the V-notch effect, and early tearing will occur from this part, causing a hose with extremely poor durability against repeated bending. It was becoming.

OBJECTS OF THE INVENTION An object of the present invention is to eliminate such conventional drawbacks and to manufacture and provide a flexible hose that is always stable, has a long life, and has repeated bending durability.

Structure of the Invention The flexible hose of the present invention has a structure in which the tubes are joined at the troughs of the hose.
The end surface of the lower tube to be joined is configured such that the inclined line forming the chevron-shaped protrusion extends downward, and is located to the left of the intersection with the inner wall of the hose fold trough. Even if a joint failure occurs and a step is created at the joint, the bending stress will not be concentrated on this part when the hose is bent repeatedly, so the structure is designed to always guarantee a long life for the hose.

DESCRIPTION OF EMBODIMENTS The embodiments will be described below with reference to the accompanying drawings.
FIG. 2 is a cross-sectional view of a tube 1 having a chevron-shaped protrusion 2, which is wound around the tube, and the tube-to-tube joint 3 is securely bonded without any step at the hose fold trough. In this case, even if the hose is repeatedly bent, the tubes are reliably joined without any steps, so even if the hose is repeatedly bent and bending occurs at the troughs of the hose, there will be no gaps between the tubes and the tubes. Since the hose is not bent concentrated at certain points, there is no risk of premature disconnection of the hose. However, due to process variations, tube 1
At the joint between the tube 1 and the tube 1, the length of the left side bottom 4 of the tube 1, which has a chevron-shaped protrusion as shown in FIG. If a bonding failure with 5 occurs,
When the stepped portion 5 bends the hose due to the V-notch effect, bending stress is localized and concentrated in this portion, causing premature disconnection of the hose.

On the other hand, by increasing the length of the left bottom portion 4 of the tube 1 shown in FIG. 3 of the present invention, when the tubes 1 are joined together at the fold valley, the end surface of the tube at the lower part of the joint as shown in FIG. 6 extends the inclined line A forming the chevron-shaped protrusion downward and is configured to be on the left side of the intersection point C with the inner wall B of the hose fold valley. Even if there is a step at the joint, there is no step near the middle of the pleat valley, where the hose is easily bent when the hose is bent, and it is on the left side of the slope forming the hose pleat, so the step 5 does not act as a V-notch effect. Since it is difficult to work and concentration of bending stress does not occur, it is possible to provide a flexible hose for a vacuum cleaner that is always stable, has a long life, and has high quality.

Effects of the Invention As is clear from the above-mentioned embodiments, the flexible hose for a vacuum cleaner of the present invention is designed such that the left side bottom 4 of the tube 1 having the chevron-shaped protrusion is lengthened, so that when the tube 1 is wound and joined, the lower side The joint end of the tube is not near the middle of the fold valley but on the outside of the slope that forms the fold, so even if a step occurs due to poor crimping at the joint, the high quality product has a stable and long life. This makes it possible to produce hoses for vacuum cleaners.

[Brief explanation of drawings]

Fig. 1 is a plan view of the hose of the present invention with a cross section, Fig. 2 is an enlarged view of the sectional view, Fig. 3 is an enlarged sectional view of the tube having the chevron-shaped protrusion of the present invention, and Fig. 4 is an enlarged cross-sectional view of the part where this tube is wound and joined, FIG. 5 is an enlarged cross-sectional view of a tube with a chevron-shaped protrusion at the time of defective molding, and FIG. 6 is an enlarged cross-sectional view of the part where this tube is wound and joined. . 1...tube, 2...flexible hose.

Claims (1)

[Claims] 1. In a flexible hose formed by winding a tube with a chevron-shaped protrusion, in a structure in which the tube-to-tube joint is performed at the trough of the hose, the end surface of the tube on the lower side of the joint is formed by an inclined line forming the chevron-shaped protrusion. A flexible hose for a vacuum cleaner, which extends downward and is located to the left of the intersection with the inner wall of the hose fold.