JPH1148269A - Manufacture of hose with coating layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a manufacturing efficiency by eliminating a complicated operation for filling beads in an inner hole of an elastic cylinder. SOLUTION: The method for manufacturing a hose with a coating layer comprises the steps of inserting an inner die into an inner hole 21a of an elastic cylinder 21 for constituting the hose 20, and integrally molding a foam sound absorbing layer 22 with an outer periphery of the cylinder 21. In this case, as the die, a coiled spring 12 having flexibility in a lengthwise direction and cylindrical shape retaining characteristics in a radial direction or cornice-like cylinder is adopted. Thus, insertion of the die into the hole 21a of the cylinder 21 and removal of the die from the hole 21a are facilitated, complicated filling operation of beads is eliminated, and hence its manufacturing efficiency is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a hose with a coating layer.

[0002]

2. Description of the Related Art As one type of a hose having a coating layer, there is a hose formed of an elastic cylinder made of rubber or the like and a foamed sound absorbing layer made of polyurethane or the like covering the outer periphery of the elastic cylinder. In such a hose with a coating layer, after setting an elastic cylinder at a predetermined portion in a mold, an unfoamed sound absorbing material is supplied to the outer periphery of the set elastic cylinder, and the same material is sealed and sealed. Is formed simultaneously with foaming at room temperature or in a heated state, and a foamed sound absorbing layer is integrally formed on the outer periphery of the elastic cylindrical body.

Further, in such a manufacturing method, a considerable high pressure is generated in a mold during foam molding of an unfoamed sound absorbing material.
Since the inner hole of the elastic cylinder is crushed and the hollow shape is greatly deformed, a large number of beads are filled in the inner hole of the elastic cylinder in advance and the openings at both ends thereof are closed. Means of setting in the mold is adopted.

[0004]

For this reason, in the method of manufacturing a hose with a coating layer of this type, the operation of filling a large number of beads into the inner hole of the elastic cylinder is indispensable, and the troublesome filling of beads is required. Due to the work involved, manufacturing efficiency cannot be said to be high. Therefore, an object of the present invention is to improve the production efficiency of a hose with a coating layer by eliminating troublesome work of filling beads.

[0005]

According to the present invention, there is provided an elastic cylindrical body,
A method for manufacturing a hose with a coating layer comprising a foamed sound absorbing layer covering the outer periphery of an elastic cylinder, wherein a foamed sound absorbing layer is integrally formed on the outer periphery of the elastic cylinder with a middle mold inserted into an inner hole of the elastic cylinder. In the method for producing a hose with a coating layer formed in the above, a middle mold having flexibility in the longitudinal direction and circular holding properties in the radial direction is used as the middle mold.

In the manufacturing method according to the present invention, the elastic tubular body is made of rubber, the covering layer is a foamed sound absorbing layer, specifically, a foamed layer of polyurethane, and the medium size is a coiled tubular body, or It is preferably a bellows-like cylinder.
Further, in the manufacturing method according to the present invention, after inserting the above-described middle mold into the inner hole of the elastic cylinder, a second cylindrical mold having a cylindrical shape along the inner diameter is fitted to each end of the elastic cylinder. It is preferable to combine them.

[0007]

According to the manufacturing method of the present invention,
As a middle mold to be inserted into the inner hole of the elastic cylindrical body, a middle mold having flexibility in the longitudinal direction and circular holding properties in the radial direction is employed. For this reason, the bending shape of the hose can be dealt with by the flexibility in the longitudinal direction of the middle mold, and the medium retains the circular shape in the radial direction against the high pressure generated in the mold during molding. Can be dealt with.

Therefore, by employing the above-mentioned medium size, a hose with a coating layer having a predetermined bent shape and a predetermined hole shape can be accurately manufactured, and the outer diameter of the medium size is made equal to the inner diameter of the elastic cylindrical body. By appropriately setting the relationship, it is possible to easily insert the medium-sized elastic cylindrical body into the inner hole and remove the medium from the inner hole. Therefore, troublesome work of filling beads can be eliminated, and the production efficiency of the hose with the coating layer can be increased.

In the manufacturing method according to the present invention, by adopting a coiled cylindrical body and a bellows-shaped cylindrical body as the medium-sized body, it is possible to insert the medium-sized elastic cylindrical body into the inner hole and to remove it from the inner hole. It can be easier.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A manufacturing method according to the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which the upper mold of the mold has been removed after the production method according to the present invention has been completed. FIG. 1 shows a lower mold 11 constituting the mold and a hose 20 with a coating layer. It is shown. Hose with coating layer 20
The hose 20 (hereinafter, may be simply referred to as a hose 20) includes a rubber elastic cylinder 21 and a foamed sound absorbing layer 22 integrally formed on the outer periphery of the elastic cylinder 21. Almost the entire outer periphery of the body 21 is covered. A metal coil spring 12 of a predetermined length, which is a first medium size, is inserted into the inner hole 21 a of the elastic cylinder 21, and a second medium size is provided at each open end of the elastic cylinder 21. Rubber stopper 13,
14 are fitted.

The lower mold 11 has rubber stoppers 13 and 1 at its center.
4 is provided with an accommodating recess 11a for accommodating the elastic tubular body 21 in a state of being fitted to each opening end.
An annular cavity 11b is provided on the outer periphery of 1a. The upper mold (not shown) also has a cavity and a cavity corresponding to the cavity 11a and the cavity 11b of the lower mold 11.

FIG. 2 shows a state before the elastic cylinder 21 is accommodated in the accommodation recess 11 a of the lower mold 11. The coil spring 12 is inserted into the inner hole 21 a of the elastic cylinder 21. Then, cylindrical rubber plugs 13 and 14 are fitted to each open end of the elastic cylindrical body 21 to close each open end. In this state, the coil spring 12 is deformed in accordance with the bent shape of the elastic cylinder 21, is located along the inner peripheral surface of the inner hole 21 a of the elastic cylinder 21, and the inner hole 21 a is closed.

FIG. 3 shows a coil spring 12 which is a first medium-sized coil. The coil spring 12 has flexibility in the longitudinal direction, has circular holding properties in the radial direction, and has elasticity. The outer dimensions are such that they can be inserted into and withdrawn from the inside of the inner hole 21a of the cylindrical body 21 with the outer periphery lightly in contact with the inner peripheral surface of the inner hole 21a. In this manufacturing method, the elastic cylindrical body 21 in this state is housed in the housing recess 11a of the lower mold 11, and the upper mold (not shown) is mounted on the upper joining surface 11c of the lower mold 11 and fixed. The unfoamed sound absorbing material is supplied to the cavity 11b of the lower mold 11 and the cavity of the upper mold in the mold, and the sound absorbing material is foamed.

As a result, the foamed sound absorbing layer 22 is integrally formed on the outer periphery of the elastic cylindrical body 21 to manufacture a hose with a covering layer. After the manufacture, if the upper mold of the mold is removed, the hose 20 in the lower mold 11 can be easily taken out. As described above, in the manufacturing method, the coil spring 12 having flexibility in the longitudinal direction and circular holding properties in the radial direction is used as the middle mold to be inserted into the inner hole 21a of the elastic cylindrical body 21. Therefore, it is possible to cope with the bending shape of the elastic cylindrical body 21 by the flexibility in the longitudinal direction, and to maintain the circular shape in the radial direction against the high pressure generated in the mold at the time of molding. Can be dealt with.

Therefore, according to the manufacturing method, by using the coil spring 12 as the middle size, the hose 20 with the coating layer having a predetermined bent shape and a predetermined hole shape can be obtained.
Can be accurately manufactured. By appropriately setting the outer diameter of the coil spring 12 in relation to the inner diameter of the elastic cylinder 21, the elastic cylinder 2 of the coil spring 12
1 can be easily inserted into the inner hole 21a and removed from the inner hole 21a, and the troublesome filling operation of beads as in the conventional manufacturing method can be eliminated, thereby increasing the efficiency of increasing the production of the piece 20. it can.

In the manufacturing method according to the present invention,
A bellows-like cylindrical body 15 shown in FIG. Further, the medium-sized coil spring 12 and bellows-like cylindrical body 15 are not limited to being made of metal, and may be made of various synthetic resins.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view of a hose with a coating layer manufactured by a manufacturing method according to the present invention and housed in a lower mold.

FIG. 2 is a cross-sectional plan view showing a state in which a first middle mold is inserted into an inner hole of an elastic cylinder and a second middle mold is fitted to an open end of the elastic cylinder.

FIG. 3 is a side view of a coil spring, which is an example of a first middle mold employed in the manufacturing method.

FIG. 4 is a cross-sectional view of a bellows-like cylindrical body which is another example of the first middle size employed in the manufacturing method.

[Explanation of symbols]

11 lower mold, 11a accommodation recess, 11b cavity,
11c: upper joining surface, 12: coil spring, 13,
14 ... rubber stopper, 15 ... bellows-like cylinder, 20 ... hose with coating layer, 21 ... elastic cylinder, 21 a ... inner hole, 22 ... foam sound absorbing layer.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 04 621: 00 B29L 23:00

Claims (6)

[Claims] 1. A method of manufacturing a hose with a coating layer, wherein a coating layer is integrally formed on an outer periphery of the elastic cylinder with an intermediate mold inserted into an inner hole of the elastic cylinder. A method for producing a hose with a coating layer, characterized in that a medium-sized hose having flexibility and radial holding ability in a radial direction is adopted. 2. The elastic cylinder is a rubber hose.
3. The method for producing a polish with a coating layer according to item 1. 3. The method according to claim 1, wherein the coating layer is a polyurethane foam layer. 4. The method for producing a hose with a coating layer according to claim 1, wherein the middle die is a coil-shaped cylinder. 5. The method according to claim 1, wherein the middle size is a bellows-shaped cylinder. 6. The method for manufacturing a hose with a coating layer according to claim 1, wherein a second cylindrical mold having a cylindrical shape along the inner diameter of the elastic cylinder is fitted to each end of the elastic cylinder in the inner hole. .