JP4391009B2 - Bellows hose manufacturing method and manufacturing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a bellows hose and a bellows hose manufactured by the manufacturing method.
[0002]
[Prior art]
The hose is for passing a fluid through the inside, and is usually connected to a mating member. Many hoses such as air systems, fuel / oil systems, and water systems are also used in automobiles. Conventionally, these hoses are mostly made of rubber or metal. However, recently, recycling, weight reduction, and cost reduction have been demanded, and the material is also being replaced by resin or resin and alloy of rubber and other members enabling this. .
[0003]
By the way, in a hose used for an automobile, there are many cases where a portion through which the hose passes is limited in terms of space, and there are few cases where the hose directly faces the counterpart member. In addition, vibration is constantly added. For this reason, a bent portion is formed to deal with the position difference, and the narrow portion is passed. In addition, a bellows portion is formed to provide flexibility and flexibility to cope with vibrations. In general, blow molding is used to manufacture a hose having a bellows portion with irregularities on the surface, using a resin or a resin alloy.
[0004]
[Problems to be solved by the invention]
Since blow molding does not use a core mold, the mold configuration is simple. However, since the outer shape is the reference, there is a drawback that it is difficult to obtain the accuracy of the inner diameter. Since most of the hoses are externally fitted to the mating member and connected, if the accuracy of the inner diameter is poor, the connection is incomplete or the seal is insufficient. For this reason, accuracy is obtained by machining or the like, but the cost increases. In addition, there is a problem that both ends of the molded product need to be cut and the cooling time becomes long.
[0005]
In this respect, the injection molding using the core mold and the outer mold has high accuracy for both the inner and outer diameters. However, if the bellows part is provided, it becomes difficult to extract the part from the core mold. For this reason, the bellows part and the connection part are formed by different molding methods, and these are integrated by bonding, welding or mechanical joining, but there is a problem that the cost is high and the function is insufficient. there were. The present invention solves such problems, and enables both injection molding and blow molding with the same mold apparatus.
[0006]
[Means for Solving the Problems]
Under the above-described problems, the present invention provides a method for manufacturing a bellows hose of resin or resin alloy having an A portion including a bellows portion and a B portion not including a bellows portion according to claim 1. Primary molding means for obtaining an intermediate product in which the A-part front shape and the B-part are not formed yet in the A-part by injection molding with the child mold, and the front shape obtained by molding the A-part pre-form in the outer mold By replacing the outer mold with the A part outer mold for forming the A part, and by secondary molding means for obtaining a finished product in which the A part front shape is formed at the A part by blow molding in which high pressure air is blown into the intermediate product. Among the outer molds, the front shape outer mold and the A-site outer mold are separated from the outer mold and configured to be movable with respect to the outer mold, and the front-shaped outer mold and the A-site outer mold are moved. Formed at different positions on the mold and moved after molding of the intermediate product Only mold is opened, thereby changing the moving type A site outer die before shape outer die, to provide a method of manufacturing a bellows hose, which comprises forming a complete a mobile and mold closing products.
[0007]
In the present invention, the primary molding means is based on injection molding, and the secondary molding means is based on blow molding. That is, in the primary molding means using the outer mold and the core mold, an intermediate product in which the A-part front shape and the B-part are not formed at the A-part yet is obtained, The finished product is formed by secondary molding means that replaces the outer shape of the former shape of the former part of A with the outer part of the A part and blows high-pressure air into the intermediate product to form the former shape of the A part at the A part. Is obtained. As a result, the intermediate product has a high dimensional accuracy because both the A part front shape and the B part are based on the inner diameter by injection molding. Further, since the bellows portion in the finished product is formed by blow molding, any bellows shape can be easily molded. In this case, the molding apparatus using the mold is sufficient, and it is not necessary to move the intermediate product in the process of obtaining the finished product from the intermediate product, which is very efficient.
[0008]
In this case, between the primary molding section and the second molding unit becomes a need for a means to change the pre-shaped outer die to the A site outer die, which, prior to shape outer die and A site outer die Are separated from the outer mold and can be moved with respect to the outer mold at different positions of the movable mold. After the primary molding means, only the movable mold is opened, and then the movable mold is moved to move the outer shape of the front mold. From the A part to the outer mold, and then the movable mold and the outer mold are moved to close the mold, the intermediate product obtained by the primary molding means is held by the core mold and the outer mold. Since it can be held in that position, it is not necessary to open and close the outer mold after the primary molding means, and the intermediate product can be held more securely, and the dimensional accuracy of the outer diameter of part B is also improved. high.
[0009]
Further, the present invention is an apparatus for manufacturing a bellows hose made of a resin or a resin alloy having an A portion including a bellows portion and a B portion not including a bellows portion according to claim 2 as an embodiment of the above manufacturing method. Of the outer shape for forming the outer shape of the B portion, the outer shape of the front shape and the A portion for forming the outer shape of the A portion before the shape where the bellows portion is not yet formed in the A portion. a mobile which is formed in different positions and an a site outer die to shape the outer, and to those having a core mold for molding the inner contour of the a-site pre-shaped and B sites, the outer mold, mobile pre-shaped outside Molding with the mold and core mold is injection molding, and molding with the movable part A part outer mold is blow molding , the outer mold and the movable mold are split molds that open, and the movable mold becomes the outer mold. The same direction as the direction different from the direction of mold opening To provide a manufacturing apparatus of bellows hose, characterized in that it is intended to move.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a bellows hose showing an example of the present invention. This bellows hose H is composed of an A portion 1 including a bellows portion and a B portion 2 not including a bellows portion made of resin or resin alloy. Become. Generally speaking, a hose is joined to other members at both ends and allows fluid to pass through. However, especially those used as automobile parts are connected regardless of the arrangement of other members while vibration is constantly applied. In order to provide flexibility and vibration absorption, the A portion 1 is formed.
[0011]
In this case, the A part 1 is usually formed at the center of the hose, and the B part 2 is usually formed at both ends. The bellows present in the A portion 1 may be one in which individual irregularities are continuous in a spiral shape or may be independent, but the shape is not particular to these shapes. In addition, there are various shapes of the B part 2 such as a cylindrical shape, a polygonal cylindrical shape, a straight shape, a taper shape, etc., but at least the shape of the connecting portion is a straight cylindrical shape for the purpose of being fitted and connected to the outer periphery of another member. Usually, it is formed.
[0012]
The present invention relates to a method for manufacturing such a bellows hose H, but in the present invention, this is indicated by the A-site front shape (hereinafter referred to as the front shape) in which the bellows portion shown in FIG. ) A first molding means for obtaining an intermediate product a having 1a and B part 2 by injection molding; and a second for obtaining a finished product b in which the front part 1a shown in FIG. It is comprised with the following shaping | molding means. In this case, both the front shape 1a and the B portion 2 are cylindrical.
[0013]
FIG. 2 is a longitudinal sectional view showing an example of a forming die used in this manufacturing method, and FIG. 3 is a transverse sectional view. The forming die of this example forms an outer shape 3 and an inner shape. A core type 4 is used. In addition, in this example, the outer shape 3 includes a front shape outer mold 5 for molding the front shape 1a, which is a stage before the bellows shape is formed, and an A portion outer mold 6 for molding the A portion 1 having the bellows shape. Independent movable mold 7 is formed. The outer mold 3 and the movable mold 7 are both split molds. In this example, the mold is moved in the left-right direction to open and close the mold.
[0014]
In addition, the front-shaped outer mold 5 and the A part outer mold 6 are formed in different positions in this, and the movable mold 7 can be moved up and down with respect to the outer mold 3 by the telescopic cylinder 8 or the like. In this case, the moving direction of the movable die 7 is set to a direction different from the left-right direction such as mold opening, and in this example, the moving die 7 moves in the up-down direction. Therefore, the front shape outer mold 5 and the A part outer mold 6 are formed at positions above and below the movable mold 7. In addition, a blow path 9 is formed inside the core mold 4 so as to correspond to the range of the movable mold 7 and communicates with the outer periphery thereof. The blow path 9 communicates with a blow mechanism (not shown). .
[0015]
If the outer mold 3, the movable mold 7 and the core mold 4 are set in the state shown in FIG. 2, the intermediate product a in which the resin is injected into the molding space formed by these and the front shape 1a and the B portion 2 are formed. The resulting primary shaping means is executed. FIG. 4 is a transverse cross-sectional view of the molding die in which the outer die 3 and the movable die 7 are retracted, and when the above primary molding means is completed, the intermediate product a obtained thereby is primarily cooled. After that, the outer mold 3 and the movable mold 7 are moved backward to open the mold. Next, the movable die 7 is lowered by the telescopic cylinder 8, the A-site outer die 6 is lowered to the position of the core die 4, and then the outer die 3 and the movable die 7 are advanced to close the die. During this time, the intermediate product a is held in that position by the core mold 4.
[0016]
FIG. 5 is a longitudinal sectional view of the molding die showing this state. After this state is reached, secondary molding means for blowing high-pressure air from the blow passage 9 formed in the core die 4 is executed. Then, the high-pressure air pressurizes between the intermediate product a and the core mold 4, and the front shape 1 a is formed at the A portion 1 having the bellows portion to become the finished product b. When the above operation is completed, the outer mold 3 and the movable mold 7 are opened again, and the finished product b inside may be taken out. In this case, the blow passage 9 is composed of a thick main pipe 9a at the center and a thin branch pipe 9b leading to the outer periphery. Of these, the branch pipe 9b is made of the material of the branch pipe 9b by injection molding of the primary molding means. It is structured so as not to enter. Specifically, the thickness is such that air can pass but the material cannot pass, or the blow passage 9 is pressurized during injection molding.
[0017]
Also, in order to secure the temperature of the front shape 1a portion of the intermediate product to be blow molded and improve the moldability, the mold involved, that is, the portion corresponding to the movable mold of the core mold is moved. Unlike the other molds, it is conceivable to control the temperature of the front-shaped outer mold 5 of the molds at a high temperature. Furthermore, in order to suppress the fluctuation of the wall thickness that is unavoidable when the bellows shape having irregularities is formed by blow molding, the thickness of the convex portion that becomes thin becomes thicker than the thickness of the other portion. The shape of the front shape outer mold 5 may be adjusted. In addition, it is of course possible to change the wall thickness between the front shape 1a and the B portion 2.
[0018]
6 to 8 are cross-sectional views of a molding die showing another manufacturing method. In this example, the moving die 7 is opened in the direction of opening the outer die 3 with the telescopic cylinder 10 or the like (this example). Left and right direction), and after the primary molding means, the outer mold 3 is left as it is, and only the movable mold 7 is opened, and then the movable mold 7 is lowered by the expansion / contraction cylinder 8 to move the front mold outer mold. 5 is changed to the A-site outer mold 6 (the movable mold 7 is then closed and blown in the same manner as in the above example). Since the outer mold 3 does not open after the intermediate product a is formed, the outer product 3 is held in the outer mold in addition to the core mold 4, and its placement effect is high, and the operation structure of the mold is simple. Thus, there is an advantage that the molding time can be shortened.
[0019]
FIG. 9 is a longitudinal sectional view of a main part of a mold showing still another manufacturing method. In this example, the mold of the present example is communicated with a suction mechanism (not shown) to the outer part A of the movable mold 7. Thus, a suction path 11 is formed which communicates with the inner periphery of the A part outer mold 6. While blow molding blows high-pressure air from the inside of the intermediate product a, this method is intended to suction the outside of the intermediate product a to form the finished product b. In this case, molding is difficult if the space between the core mold 4 and the intermediate product a is vacuum (or reduced pressure), but in reality, gas is generated from the material during injection molding, and this part is pressurized. And realization is possible. The suction molding may be performed in combination with blow molding or may be performed independently. According to the former, even if the A portion 1 has a complicated shape, the formation is more reliable. According to the latter, it is not necessary to form a blow path in the core mold 4 and the material is blown at the time of injection molding. There is no worry of going back to the road.
[0020]
【The invention's effect】
As described above, according to the present invention, in manufacturing a hose having a portion including a bellows portion and a portion not including the bellows portion, a primary shape that does not yet form the bellows portion is formed by the primary molding means by injection molding, and then the second shape is formed by blow molding. Since the bellows portion is formed by the secondary forming means, the inner diameter can be formed with high accuracy by the primary forming means, and an arbitrary bellows shape can be formed by the secondary forming means. During this time, after the primary molding, the outer mold that forms the outline of the B part is not opened, so there is no need to change the position of the molded product or the setup of the apparatus, which is efficient and the molding time is short. Furthermore, the dimensional accuracy of the outer diameter of the portion B is also high.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a bellows hose showing an example of the present invention.
FIG. 2 is a longitudinal sectional view of a forming die in the process of forming a bellows hose showing an example of the present invention.
FIG. 3 is a cross-sectional view of a forming die in the process of forming a bellows hose showing an example of the present invention.
FIG. 4 is a cross-sectional view of a forming die in the process of forming a bellows hose showing an example of the present invention.
FIG. 5 is a cross-sectional view of a forming die in the process of forming a bellows hose showing an example of the present invention.
FIG. 6 is a cross-sectional view of a forming die in the process of forming a bellows hose showing another example of the present invention.
FIG. 7 is a cross-sectional view of a forming die in the process of forming a bellows hose showing another example of the present invention.
FIG. 8 is a cross-sectional view of a forming die in the process of forming a bellows hose showing another example of the present invention.
FIG. 9 is a longitudinal sectional view of a main part of a forming die in a process of forming a bellows hose showing another example of the present invention.
[Explanation of symbols]
1 A part 2 B part 3 outer mold 4 core mold 5 front shape outer mold 6 bellows outer mold 7 moving mold 9 blow path 11 suction path a intermediate product b finished product

Claims (2)

A manufacturing method of a resin or resin alloy bellows hose having an A portion including a bellows portion and a B portion not including a bellows portion is not formed at the A portion by injection molding using an outer mold and a core mold. a primary forming means for obtaining an intermediate product obtained by forming the region before the shape and B site, the shape outer die before was molded a site prior shape in the outer mold was replaced with a-site outer die for molding the a site, the intermediate In the second molding means for obtaining a finished product in which the A-site front shape is formed at the A-site by blow molding in which high-pressure air is blown into the product, the front-shaped outer mold of the outer mold and the A-site outer mold Is separated from the outer mold and is configured as a movable mold that can move relative to the outer mold, and the front-shaped outer mold and the A-site outer mold are formed at different positions on the movable mold, and only the movable mold is formed after the intermediate product is molded. Open the mold and move the moving mold from the outer shape With change in the outer mold, bellows manufacturing method of a hose which is characterized by shaping the mobile a closed mold to the finished product. An apparatus for manufacturing a bellows hose of resin or resin alloy having an A part including a bellows part and a B part not including a bellows part is provided to be movable with respect to an outer mold for forming an outline of the B part and the outer mold A movable mold in which a front shape outer mold for forming the outer contour of the A site front shape in which the bellows part is not yet formed in the A site and a A site outer mold for modeling the outer shape of the A site are formed at different positions; And a core mold for shaping the inner part of the B part, and the molding by the outer mold, the movable front shape outer mold and the core mold is injection molding, and the molding by the movable A part outer mold is In the blow molding , the outer mold and the movable mold are split molds that open the mold, and the movable mold moves in the same direction as the direction different from the mold opening direction with respect to the outer mold. apparatus for manufacturing a bellows hose.

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