JPH0546474B2 - - 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 durability against repeated bending 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, , which had a structure in which they were joined at the folds and valleys, and there were no particular positional restrictions on the joining structure. Therefore, as shown in Figure 2, if the joints are reliably joined without any steps, there will be no problem with the life of the hose.However, as shown in Figure 6, there may be manufacturing process variations. When a step is formed in the folded valley, when the hose is repeatedly bent, it bends from the step, causing stress concentration due to the V-notch effect, resulting in a hose with extremely poor durability against repeated bending.

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, and the upper tube end surface of the joint portion is in contact with the slope line forming the chevron-shaped protrusion and the troughs. By joining the hose so that it lies on the fold line that forms the chevron-shaped protrusion above the bisector of the angle formed by the horizontal line, even if a joint failure occurs and a step is created at the joint, the hose can be repeatedly connected. Since bending stress is not concentrated on this part when bending, the structure is designed to always guarantee a long life of 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 bent repeatedly, there is no step between the tubes and the joints are securely connected. Since the hose is not bent concentrated in a few places, such as the hose, 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 bottom right side of the tube 1, which has a chevron-shaped protrusion as shown in FIG. When a joint failure occurs, when the hose is bent due to the V-notch effect of the stepped portion 5, bending stress is locally generated and concentrated in this portion, causing premature disconnection of the hose.
In contrast, tube 1 shown in FIG. 3 of the present invention
By lengthening the right bottom part 4 of the tube 1
When joining two pieces together at the folds and valleys, as shown in FIG. By configuring the structure so that the fold line forms the chevron-shaped protrusion above the segment line D, even if a pressure welding failure occurs at the joint and a step is created at the joint, the fold that is likely to bend when bending the hose can be avoided. Since there is no step near the middle of the trough and it is on the slope line side, the step 6 is less likely to act as a V-notch effect and concentration of bending stress does not occur, so it is always stable and has a long life of high quality. It is possible to provide a flexible hose for a vacuum cleaner having the following features.

Effects of the Invention As is clear from the above embodiments, the flexible hose for a vacuum cleaner of the present invention has the right bottom 4 of the tube 1 having a chevron-shaped protrusion elongated, so that the tube 1 can be wound around the tube 1 and the upper side when joined. The joint end of the tube is not near the middle of the fold, but on the slope line side, so even if a step occurs due to poor crimping at the joint, this high-quality vacuum cleaner always has a stable and long life. This makes it possible to produce hoses for general use.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] 1. A flexible hose formed by winding a tube with a chevron-shaped protrusion, and in a structure in which the tube-to-tube joint is performed at the trough of the hose, the end surface of the tube above the joint part has an inclined line forming the chevron-shaped protrusion. A flexible hose for a vacuum cleaner, which is arranged to lie on a fold line forming a chevron-shaped protrusion above a bisector of an angle formed by the horizontal line in contact with the fold valley part.