JPH07171882A - Manufacture of flexible hose and flexible hose - Google Patents

Abstract

PURPOSE:To continuously and integrally mold bellows, the wall thickness of which is different from one another every predetermined length by a method wherein annular parison, the wall thickness of which is different from one another every predetermined length, is extruded with a continuous extrusion blow molder, on which mold units are connected to one another in the fashion of crawler belt, and then lead to the mold units for blow molding. CONSTITUTION:In a pair of molds 21 and 21' of a continuous extrusion blow molder used, mold units 22 facing each other are connected to one another in the fashion of crawler belt and circulated. At the mold unit 22, when necessary, mold units 22a and 22b, the shapes of which are different from each other, are connected as one set. Thus, annular parison 24 is continuously extruded from an annular die 23. At this time, extrusion speed is raised for thicker portion 25 such as the wall thickness of the internal hose of a washing machine or the like and lowered for thinner portion 26 such as the wall thickness of its external hose. In the extruded parison 24, gas is blasted from a blowing hole 27, resulting in pressing the parison 24 against the mold unit 22 so as to produce bellows 28.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a flexible hose which is mainly used in a washing machine and which continuously and integrally forms at least two types of bellows tubes having different configurations, and at least two types having different configurations. And a flexible hose in which the bellows tube is continuously and integrally formed.

[0002]

2. Description of the Related Art For example, in a washing machine, since drainage of laundry is discharged from a washing tub through a casing containing a power unit and a rotating unit to a drainage port outside the casing, a flexible hose of a bellows tube is used. It is installed as a drain hose.
Conventionally, this kind of flexible hose has been used by integrally molding the same material and shape as a whole. However, in general, the part used inside the casing (internal hose) is often installed in a bent state, and is subjected to severe vibration, so a high level of bending resistance, vibration resistance, and durability Must use a hose. For this purpose, it is necessary to use a high-quality material for the hose, or to increase the wall thickness of the tube and increase the unevenness forming the bellows. On the other hand, the portion used outside the casing (external hose) is not so required to have bending resistance and vibration resistance, and conversely, it is desirable that it is lightweight, has a small outer diameter, and is easy to handle. In particular, in a fully automatic washing machine, since the usage conditions inside the casing are severe, improvement in bending resistance and vibration resistance of the internal hose is desired.

[0003]

If the entire drainage hose that meets these demands is integrally manufactured with the same shape in accordance with the internal hose under severe operating conditions, not only is it inconvenient to handle the external hose, but also the cost is high. Become. Alternatively, the inner hose and the outer hose may be separately formed into shapes suitable for use conditions, and then the two may be joined together to be manufactured. However, hoses that are molded and joined separately have problems that the joints are easily dislodged during use, are difficult to handle, the joints are easily damaged and lack durability, and the manufacturing method is complicated and the manufacturing cost is high. . This problem is solved by integrally molding an inner hose and an outer hose having different performances using a crosshead blow extruder. However, for cost reduction,
Furthermore, it is necessary to complete a manufacturing method with high production efficiency. In order to meet such demands, the present inventor diligently researched and produced a flexible hose manufacturing method with high production efficiency and a flexible hose that can be used economically while withstanding harsh use conditions. As a result, the present invention could be completed.

[0004]

The above-mentioned problems are solved by the present invention,
That is, using a continuous extrusion blow molding machine in which the die unit is connected in the shape of a crawler belt, the extrusion speed is adjusted, and an annular parison of different wall thickness is extruded for each predetermined extrusion length, and the extruded parison is extruded. Manufacture of a flexible hose, characterized in that a flexible bellows tube having a different wall thickness for each predetermined length is guided and blown into the mold unit, and is repeatedly and integrally formed. It can be solved by using the method. Further, using a continuous co-extrusion blow molding machine in which the die units are connected in a crawler belt shape using at least two kinds of polymers and equipped with multiple annular die for extruding different polymers for each ring, For each extrusion length of, the extrusion speed from each annular die is adjusted to an arbitrary speed from zero to the maximum amount, and an annular parison consisting of a single layer or multiple layers is extruded, and the extruded parison is the above-mentioned die unit. It is also possible to solve the problem by guiding and blowing into the inside, and repeatedly and integrally forming a flexible bellows tube in which the configuration of the tube wall is different for each predetermined length.

Further, a die unit is connected in a crawler belt form, and a continuous co-extrusion blow molding machine equipped with a multi-annular die for extruding a different polymer for each ring is used for each predetermined extrusion length. By adjusting the extrusion speed from each annular die, an annular parison consisting of multiple layers is extruded, the extruded parison is guided into the mold unit and blown, and the thickness of each layer is different for each predetermined length. It is also possible to solve the problem by repeatedly molding a flexible multi-layered bellows tube into a continuous and integral body.

Further, in order to solve the above-mentioned problems, the present invention provides that at least two types of bellows tubes having a single wall and / or a multi-layer structure having different tube wall configurations are continuously and integrally molded. Provides a characteristic flexible hose. A multi-layer structure made of different polymers, and at least two kinds of bellows tubes, which are composed of tube walls having different thicknesses, are continuously and integrally molded.
A flexible hose and a flexible hose in which at least one bellows tube has a different shape among the bellows tubes constituting the flexible hose which is continuously and integrally molded are preferable.

For a more specific purpose, that is, in the drainage hose of a washing machine, a bellows-shaped inner hose mounted inside the casing of the washing machine and a bellows-shaped outer hose exposed to the outside of the casing are continuously and integrally formed. Although any of the above flexible hoses can be preferably used, further, the portion corresponding to the inner hose has a larger difference in diameter between the crest and the trough of the bellows than the portion corresponding to the outer hose. A sex hose is suitable for a washing machine. Here, the different polymers also include polymers composed of the same kind of polymer but having different compositions. Further, the different configuration of the tube wall means, for example, the thickness of each layer constituting the tube wall, the shape of the tube wall,
It means that the type of polymer, the composition ratio of the polymer, etc. are different. The thickness includes the case where the thickness is zero.

[0008]

Actions and Embodiments The present invention will be specifically described with reference to the drawings, taking a drainage hose for a washing machine as an example. 1 (a) to 1 (d) are schematic views showing an example of a tube wall cross section of a flexible hose according to the present invention, and FIG. 2 is an example of a main part of a continuous extrusion blow molding machine used for carrying out the present invention. It is a sectional view showing typically. First, the flexible hose of the present invention of a single layer integrated using a single polymer, but different in shape and thickness for each predetermined length corresponding to the inner hose and the outer hose, and a manufacturing method thereof. Will be described.
Usually, the opposing mold units 22 are connected in a crawler belt shape, and form a pair to form the molds 21 and 21 '.
A continuous extrusion blow molding machine is used.
First, the material forming the tube wall is extruded from the annular die 23 to continuously form the annular parison 24. For the parison corresponding to the portion 25 forming the inner hose, which is desired to be thick, the extrusion speed is increased, and for the parison of the portion 26 forming the outer hose, the extrusion is performed so as to be thin. Slow down. The parison is continuously extruded while repeatedly changing the extrusion speed. Each extrusion rate is determined in consideration of the shape of the flexible hose, the outer diameter, the desired wall thickness, and the like. For example, when the bellows has large irregularities, the pipe wall becomes thinner than when the bellows are small, and therefore the extrusion speed must be increased in order to make the pipe wall thicker.

The extruded parison 23 is pressed against the mold unit 22 by the gas blown from the blow hole 27 and is molded into a bellows tube. The molds 21 and 21 'are a set of a mold unit 22a for the internal hose and a mold unit 22b for the external hose having a different shape from each other, which are required to form a desired hose length. , This set of mold units is connected and circulated. When the shape of the inner hose and the shape of the outer hose are the same, common mold units can be connected. The molded bellows tube 28 is
Cool, take out continuously and cut the inner and outer hose parts together. The flexible hose manufactured by repeating this operation has desired wall thicknesses and inner and outer diameters in the inner hose portion and the outer hose portion, respectively, and both are integrally molded. The hose opening and the mounting portion to the casing can also be integrally formed by connecting a die unit for that, if necessary.

Next, the present invention provides mainly as a drainage hose for a washing machine in order to meet more severe requirements.
A flexible hose in which the inner hose portion and the outer hose portion are integrated and two or more different polymers are used and the tube wall structure is different for each portion, and a method for manufacturing the flexible hose will be described. In order to extrude two or more different polymers, in the present invention, the mold units are connected in a crawler belt shape, and each ring extrudes different polymers.
A continuous co-extrusion blow molding machine equipped with multiple annular ferrules is used. The extrusion speed of each extruder communicating with each annular die is adjusted to a predetermined speed based on the required thickness of each layer of the tube wall of the hose, and if necessary, the running speed of the mold is adjusted. , Set the thickness of each layer of the hose pipe wall and the total thickness. Then, a predetermined extrusion length, that is, for each length corresponding to the internal hose and the external hose, by changing the extrusion speed of each extruder and / or the running speed of the mold to a condition suitable for each part, Flexible hoses having different tube wall configurations for each predetermined length can be integrated and repeatedly and continuously manufactured.

For example, using the above-mentioned molding machine equipped with a two-layer annular die, one of which extrudes the polymer A and the other of which extrudes the polymer B, the thicknesses of the polymer A and the polymer B are different between the inner hose and the outer hose. And / or a multi-layered bellows tube having different tube wall thicknesses can be continuously and integrally molded. Furthermore, by adjusting the extruding amounts of both polymers alternately to zero, it is possible to continuously and integrally form a bellows tube having a single layer structure composed of the polymer A or the polymer B. If there is a problem in joining polymer A and polymer B, 3
It is also possible to insert the third polymer in a single layer or multiple layers into the joint portion using a molding machine equipped with a layered annular die and integrally manufacture the inner hose and the outer hose. Further, as in the case of using a single polymer, by using mold units having different shapes, it is possible to integrally manufacture flexible hoses having different tube wall shapes at predetermined lengths and continuously manufacture them. it can.

The present invention will be described in more detail by taking a drainage hose for a washing machine as an example. For example, when the polymer A is made of a material having excellent vibration resistance and bending resistance (for example, a thermoplastic elastomer) and the polymer B is made of an inexpensive general-purpose material (for example, polyethylene), when the portion forming the internal hose 11 is extruded. At a suitable rate, the polymer A is fed up to a predetermined extrusion rate, and at the same time, the extrusion rate of the polymer B is reduced to zero at an appropriate rate. The appropriate speed may be any speed at which the inner hose and the outer hose can be firmly and integrally joined, and depends on the type of polymer, the thickness of the tube wall, and the like. Further, dropping to zero means that the polymer A and the polymer B are substantially alternately extruded. In the outer hose portion 12, conversely, B is raised to a predetermined extrusion rate and supplied, and the extrusion rate of A is set to zero. In this way, a flexible hose with the required performance for each part can be provided at low cost. Further, for example, the inner hose portion 11 has a structure in which 80% of the wall thickness is polymer A and 20% is polymer B, and conversely, the outer hose portion 12 is the polymer B in which 80% of the wall thickness is 80%. The polymer A accounts for 20% of the thickness, and the cost can be reduced without lowering the practical performance of the hose.

Furthermore, in a state where each bellows tube is integrated,
It is preferable that each part of the hose has an appropriate shape that can withstand the stress applied to each part of the hose because the performance of the hose is further improved. For example, the internal hose of a fully automatic washing machine has a cycle of 1
It is not uncommon to receive vibration with an amplitude of about 30 mm at 000 times / minute. Therefore, the flexible hose of the present invention is suitable for the drainage hose. For example, the pipe wall of the flexible hose, in which the difference in diameter between the peak and the valley of the bellows tube in the portion corresponding to the inner hose is made larger than that in the portion corresponding to the outer hose, is And at least two types of polymers such as polyolefin. By increasing the unevenness in the inner hose having a thick thermoplastic elastomer layer and decreasing the unevenness in the outer hose having a thick polyolefin layer, the vibration resistance and bending resistance are further improved.

[0014]

EFFECTS OF THE INVENTION By using the method for manufacturing a flexible hose of the present invention, it is possible to adjust the extrusion speed of the polymer and the running speed of the mold for each predetermined extrusion length, and to use different mold units. It is possible to easily repeatedly mold at least two types of bellows tubes having different tube wall configurations such as wall thickness and shape by a simple operation. Also, by using a continuous co-extrusion blow molding machine equipped with multiple annular mouthpieces, by adjusting the extrusion speed of each multiple annular mouthpiece, flexible hoses with different tube wall configurations can be repeatedly and integrally formed. can do. Therefore, a hose having different performances in each part of the hose can be easily manufactured continuously and integrally at low cost. The flexible hose manufactured in this manner is suitable for a washing machine hose having different performances required in the casing and the exposed portion.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a tube wall cross section of a flexible hose according to the present invention. (A) A flexible hose in which bellows tubes having different wall thicknesses are continuously and integrally formed. (B) A flexible hose having a single-layer structure in which bellows tubes having different tube wall configurations are continuously and integrally formed. (C) A flexible hose having a single-layer structure and a multi-layer structure in which bellows tubes having different tube wall configurations are continuously and integrally formed. (D) A flexible hose having a multi-layer structure in which bellows tubes having different thicknesses are formed continuously and integrally.

FIG. 2 is a sectional view schematically showing an example of a main part of a continuous extrusion blow molding machine used for carrying out the present invention.

[Explanation of symbols]

11: Internal hose 12: External hose A: Material excellent in vibration resistance and bending resistance B: General-purpose material 21,21 ': Mold 22: Mold unit (subscript a: for internal hose b: for external hose) 23: Annular die (annular base) 24: Parison 25: Part forming internal hose 26: Part forming external hose 27: Blow hole 28: Bellows tube

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location // B29L 9:00 23:18 (72) Inventor Seiji Hattori Tigers 6 Awayo, Kakegawa, Shizuoka Prefecture Polymer Co., Ltd.Shizuoka Plant (72) Inventor Yoshiro Nakano 2150, Takanezawa-cho, Shioya-gun, Tochigi Pref. Tochigi factory

Claims (7)

[Claims] 1. A continuous extrusion blow molding machine in which a mold unit 22 is connected in a crawler belt shape is used to adjust an extrusion speed to extrude an annular parison 24 having a different wall thickness for each predetermined extrusion length. The extruded parison is guided into the mold unit and blown, and flexible bellows tubes 28 having different wall thicknesses at predetermined lengths are repeatedly and integrally formed. Manufacturing method of flexible hose. 2. A continuous co-extrusion blow molding machine, in which mold units are connected in a crawler belt form and equipped with multiple annular die for extruding different polymers for each ring, at a predetermined extrusion length. , The extrusion speed from each annular die 23 is adjusted to an arbitrary speed from zero to the maximum amount, an annular parison composed of a single layer or a plurality of layers is extruded, and the extruded parison is guided into the mold unit and blown. A method of manufacturing a flexible hose, characterized in that a flexible bellows tube having a different tube wall structure for each predetermined length is repeatedly and integrally formed. 3. A continuous co-extrusion blow molding machine, in which mold units are connected in a crawler belt form and equipped with multiple annular die for extruding different polymers for each ring, at a predetermined extrusion length. Adjusting the extrusion speed from each annular die, extruding an annular parison consisting of multiple layers, and guiding the extruded parison into the mold unit to blow,
A method for manufacturing a flexible hose, characterized in that a flexible bellows tube having different thicknesses for each predetermined length is repeatedly and integrally formed. 4. At least two types having different tube wall configurations,
A flexible hose characterized in that a bellows tube having a single-layer and / or a multi-layer structure is continuously and integrally molded. 5. A multi-layer structure made of different polymers, wherein at least two kinds of bellows tubes each having a different thickness of each layer are continuously and integrally molded. Flexible hose. 6. A flexible hose characterized in that at least one of the bellows tubes constituting the flexible hose according to claim 4 or 5 has a different shape. 7. The bellows-shaped inner hose mounted in the casing of a washing machine and the bellows-shaped outer hose exposed to the outside of the casing are continuously and integrally formed. A flexible hose for a washing machine, characterized in that the portion corresponding to the inner hose has a larger difference in diameter between the peak and the trough of the bellows than the portion corresponding to the outer hose. hose.