JPH1190993A - Manufacture of bent hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mold an end inner surface of a hose in a desired shape and size accuracy in a method for manufacturing a bent hose having the steps of setting to engage an unvulcanized rubber hose with a molding groove of an outer mold formed in a predetermined bent shape, and vulcanizing it. SOLUTION: In the method for manufacturing a bent hose comprising the steps of setting to engage an unvulcanized rubber hose 12 along a molding grove 14 of an outer mold 10 for holding the hose 12 in a predetermined bent shape, and vulcanzing it in the state, mouth molds 18, 20 for partly molding end inner surface by engaging the end inner surface of the hose 12 into contact with an end of the hose 12 over a predetermined axial length are mounted in engaged state, and the hose 12 is held in a bent shape by using the mold 10 in the state, and vulcanized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a curved hose, and more particularly to a method of vulcanizing an unvulcanized rubber hose (which may have a reinforcing layer or a resin layer, but is particularly based on rubber). The present invention relates to a manufacturing method using an outer mold whose shape is restrained from the side.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a curved hose having a predetermined bent portion, a completely unvulcanized rubber hose (hereinafter referred to as a completely unvulcanized rubber hose or a semi-vulcanized rubber hose formed into a straight tube by extrusion molding or the like) is used. Is generically referred to as an unvulcanized rubber hose) by inserting a mandrel deformed into a round shape of iron and having a predetermined bent shape into the hollow inside of the hollow, and deforming the unvulcanized rubber hose into a shape following the mandrel, and In general, a method of heating and vulcanizing an unvulcanized rubber hose while holding the rubber hose in a state of being held is used.

FIG. 5 shows this concretely.
In the figure, reference numeral 200 denotes a mandrel which has been deformed into a predetermined bent shape. In this method, a release agent is generally applied to the surface of the mandrel 200 (I),
The mandrel 200 is inserted into the straight tubular unvulcanized rubber hose 202 while bending and deforming the hose (II). In this state, the unvulcanized rubber hose 202 and the mandrel 200 are both heated to vulcanize the unvulcanized rubber hose 202. (III).
Thereafter, the mandrel 200 is removed from the vulcanized hose 204 after vulcanization (IV), and the release agent remaining on the inner surface of the mandrel 200 and the product hose (curved hose) 204 is washed and removed ((V), (VI)). ).

However, in the case of the conventional manufacturing method using such a mandrel 200, the frictional force between the mandrel 200 and the unvulcanized rubber hose 202 or the curved hose 204 after vulcanization, particularly a large resistance force at the bent portion. Therefore, when the mandrel 200 is inserted into the unvulcanized rubber hose 202 and when the mandrel 200 is removed from the curved hose 204 after vulcanization, the mandrel 200 must be performed with a strong force. It was a difficult task.

In recent years, as shown in FIG. 6, an outer mold 208 having a molding groove 206 having a predetermined curved shape is used, and a straight tubular unvulcanized rubber hose 202 is formed along the molding groove 206 of the outer mold 208. A method has been considered in which the hose is set in a radial direction and vulcanized in that state to obtain a curved hose.

According to this manufacturing method, the straight tubular unvulcanized rubber hose 202 can be fitted and set in the outer mold 208 with a relatively small force, and the curved hose can be taken out of the outer mold 208 even after vulcanization. There is an advantage that work can be performed easily.

In addition, in the case of this manufacturing method, since a mandrel is not used, it is not particularly necessary to apply a release agent. Therefore, not only the step of washing and removing the release agent after vulcanization can be made unnecessary, but also the release The advantage is obtained that it is possible to avoid the problem that the agent and the detergent for removing the agent enter the waste liquid and the water treatment for improving the water quality becomes difficult.

[0008]

However, in the case of vulcanization using only the outer mold 208 without using the above-mentioned mandrel, the vulcanization is performed in a state where the inner surface is not regulated. It is inevitable that the shape and dimensional accuracy of the inner surface of a shaped hose product will deteriorate.

Generally, a curved hose of this kind is used as an automotive hose. In this case, the curved hose is often used in a state where a mating pipe is usually fitted into an inner surface of an end portion. At this time, if the shape and dimensional accuracy of the inner surface of the end portion are poor, it is difficult to satisfactorily insert the mating pipe into the end portion of the hose, and the sealability at the fitting assembly portion is impaired. Occurs.

[0010]

The invention of the present application has been made to solve such a problem. According to a first aspect of the present invention, there is provided a method for manufacturing a curved hose, wherein the unvulcanized rubber hose is fitted along the formed groove of an outer mold having a formed groove for holding the unvulcanized rubber hose in a predetermined bent shape. In a method of manufacturing a curved hose by vulcanizing in that state, at least one end of the unvulcanized rubber hose is contact-fitted to the inner surface of the end over a predetermined axial length. A mouth forming die for partially forming the inner surface of the same end is fitted in a fitting shape, and the unvulcanized rubber is vulcanized while being held in a bent shape using the outer die. .

According to a second aspect of the present invention, in the method for manufacturing a curved hose according to the first aspect, the mouth forming die is attached to only one end of the unvulcanized rubber hose and the other end is open to the outside. In this state, the unvulcanized rubber hose is vulcanized with a steam can.

According to a third aspect of the present invention, in the method for manufacturing a curved hose according to the first aspect, each of the mouth forming dies corresponding to each of the unvulcanized rubber hoses is attached to both ends thereof, and at least one of the mouth forming dies is provided. And a through-hole for communicating the inside and the outside of the unvulcanized rubber hose, and the unvulcanized rubber hose is vulcanized in a steam can.

[0013]

As described above, according to the manufacturing method of claim 1, when the unvulcanized rubber hose is vulcanized into a predetermined bent shape using the outer mold, at least one end of the unvulcanized rubber hose is used. The vulcanization treatment is performed by fitting a mouth forming die into a fitting shape. According to this method, the inner surface of at least one end of the curved hose can be formed into a desired shape and dimensional accuracy.

Therefore, when one end of the fitting is fitted to the mating pipe and assembled, the fitting and assembling work can be performed smoothly, and good sealing performance at the fitted and assembled portion is ensured. be able to.

In the production method of the present invention, various means can be used as a vulcanizing means. In general, steam vulcanization, that is, a method in which an unvulcanized rubber hose is housed in a steam can together with an outer mold, and Is sealed and a predetermined pressure (for example, 3 to 4 k
gf / cm ² ) is used. At this time, if both ends of the unvulcanized rubber hose are in a closed state, it becomes impossible to guide steam to the inside of the unvulcanized rubber hose and heat and vulcanize it from the inner surface side.

Here, in the method of claim 2, the mouth forming die is attached to only one end of an unvulcanized rubber hose,
The other end is subjected to steam can vulcanization with the open state, so that it is possible to prevent the occurrence of a pressure difference between the inside and outside of the unvulcanized rubber hose by introducing steam having the above pressure into the inside of the unvulcanized rubber hose. At the same time, the unvulcanized rubber hose can be favorably heated and vulcanized from the inside.

On the other hand, according to a third aspect of the present invention, a corresponding die is attached to each end of the unvulcanized rubber hose, and at least one of the unmolded rubber hoses communicates the inside and the outside of the unvulcanized rubber hose. According to this method, the inner surfaces of both ends of the curved hose can be finished to a desired shape and dimensional accuracy, and the inside of the unvulcanized rubber hose can be vulcanized. The steam can be guided through the through hole of the mouth forming die, and the unvulcanized rubber hose can be heated and vulcanized from the inner surface side.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; In FIG. 1, reference numeral 10 denotes an outer mold for holding and restraining an unvulcanized rubber hose 12 formed into a straight tube by extrusion or the like and cut to a predetermined size in a predetermined bending shape from the outer surface side. Are provided with a plurality of bent groove portions 14 corresponding to the shape of.

Here, each molding groove portion 14 is formed to have a certain length longer than the length of the unvulcanized rubber hose 12 or the curved hose 30 (see FIG. 2), and as shown in FIG. A gap 16 is formed between the second mouth forming die 20 and the end face of the groove when the mouth forming die 20 is mounted. The gap 16 is provided so that a finger can be inserted when the curved hose 30 is taken out after vulcanization, so that the curved hose 30 can be easily taken out.

Reference numeral 18 denotes a first mouth forming die for constraining the inner surface of one end of the unvulcanized rubber hose 12 over a predetermined axial length. The first mouth forming die is formed by welding, screwing, or the like. Are previously fixed to the outer mold 10 by the fixing means. As shown in FIG. 3, the first mouth forming die 18 includes a shaft portion 22 as a die body and a large-diameter head 23, and the head 23 is fixed to the outer die 10. .

The shaft portion 22 has a circular cross section, and is in contact with the inner surface of one end of the unvulcanized rubber hose 12 over a predetermined axial length to restrict the shape of the inner surface of the end. The first die 18 has a solid internal structure as shown in FIG. The large diameter head 23 has an outer diameter substantially equal to the outer diameter of the unvulcanized rubber hose 12.

Reference numeral 20 denotes a second mouth forming die for constraining the inner surface of the other end of the unvulcanized rubber hose 12 over a predetermined axial length, and the second mouth forming die 20 is also a mold body. And a large-diameter head 25. However, the second die 20 is not fixed to the outer die 10.

The shaft portion 24 has a circular cross-section, and its outer diameter is selected so that it fits in contact with the inner surface of the other end of the unvulcanized rubber hose 12 to restrain the inner surface of the end. I have. On the other hand, the large-diameter head 25 has substantially the same outer diameter as the outer diameter of the unvulcanized rubber hose 12, similarly to the head 23 of the first mouth forming die 18. A through-hole 26 is formed at the center of the second opening mold 20 so as to penetrate the same in the axial direction, and the inside and the outside of the unvulcanized rubber hose 12 communicate with each other through the through-hole 26. It is to be.

FIG. 2 shows the outer die 10 and the first mouth forming die 18.
2 shows a method of manufacturing a curved hose 30 using a second mouth forming die 20. As shown in the drawing, in the manufacturing method of the present embodiment, a second mouth forming mold 20 is previously mounted on an end of a straight tubular unvulcanized rubber hose 12, and the remaining end of the unvulcanized rubber hose 12 is attached to the outer mold 10. Then, the unvulcanized rubber hose 12 is fitted and set along the forming groove 14 of the outer mold 10 while bending and deforming the unvulcanized rubber hose 12 in this state.

In this state, the outer mold 10 is inserted into the steam vulcan 28 together with the plurality of unvulcanized rubber hoses 12 fitted and set in the respective molding grooves 14 as shown in FIG. Steam vulcanization is performed for a predetermined time. At this time, the steam in the pressurized state in the steam vulcanizing can 28 is guided into the unvulcanized rubber hose 12 through the through hole 26 of the second mouth mold 20. Therefore, the pressure difference between the inside and the outside of the unvulcanized rubber hose 12 does not occur, and the unvulcanized rubber hose 12 is moved from the inner surface side thereof without the disadvantage that the unvulcanized rubber hose 12 is crushed by the differential pressure. Is also heated and vulcanized, so that the whole is evenly vulcanized.

When the vulcanization treatment has been performed for a predetermined time, the outer mold 10 is taken out from the steam vulcanization can 28 and the vulcanized curved hose 30 is removed as shown in FIG. It is extracted from each forming groove 14 of the mold 10. Here, a curved hose 30 having the desired bent shape and the inner surface of the end formed into the desired shape and dimensional accuracy is obtained.

As described above, the manufacturing method of the present embodiment employs the outer mold 10
When the unvulcanized rubber hose 12 is vulcanized into a predetermined bent shape by using the first and second mouth forming dies 18 and 20 at both ends thereof, the vulcanizing process is performed. According to this method, the inner surfaces of both ends of the curved hose 30 can be formed into a desired shape and dimensional accuracy. Therefore, when assembling the both ends to the mating pipe in the fitted state, the fitting and assembling work can be performed smoothly, and good sealing performance at the fitted and assembled portion can be ensured.

In the method of this embodiment, the unvulcanized rubber hose 12 is vulcanized by steam.
0 has a through-hole 26 formed therein, and the unvulcanized rubber hose 1
2 is in communication with the outside, it is possible to introduce steam into the unvulcanized rubber hose 12 during steam vulcanization, and thus the unvulcanized rubber hose 12 is formed by the steam pressure in the steam vulcanizer. The unvulcanized rubber hose 12 can be satisfactorily vulcanized with steam from the inner surface without being crushed.

The above is an example of the case where the vulcanization treatment is performed in a state where the first mouth forming die 18 and the second mouth forming die 20 are attached to both ends of the unvulcanized rubber hose 12. As shown in FIG. 4, it is also possible to mount the mouth forming die 18 on only one end of the unvulcanized rubber hose 12 and vulcanize it with the other end open. Also in this case, the inner surface of at least one end of the curved hose 30 can be finished to a desired shape and dimensional accuracy.

In this case, as the mouth forming die 18, one having no through hole 26 and having a solid inside can be used, but one having the through hole 26 can also be used.

Although the embodiment of the present invention has been described in detail, this is merely an example. For example, in the above-described embodiment, both ends of the curved hose 30 have a straight shape over a predetermined axial length, and accordingly, each shaft portion in the first mouth forming die 18 and the second mouth forming die 20. 22 and 24 are examples in which both are straight in the axial direction and the outer peripheral surface is also a straight surface in the axial direction. However, when the shape of the end of the curved hose 30 is formed into another shape, The present invention is also applicable.

Further, the present invention is applicable not only to a hose made of rubber alone, but also to a rubber hose in which a resin is partially compounded, and various vulcanization methods can be adopted as the vulcanization method. The present invention can be practiced in variously modified forms without departing from the spirit thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an outer mold used in a method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the method of the embodiment.

FIG. 3 is a cross-sectional view of a main part in a state where an unvulcanized rubber hose and a mouth forming die are set on the outer die of FIG. 1;

FIG. 4 is a view corresponding to FIG. 3 in a method according to another embodiment of the present invention.

FIG. 5 is a view showing an example of a conventional method for manufacturing a curved hose.

FIG. 6 is a view showing an example of a conventional method of manufacturing a curved hose different from FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Outer die 12 Unvulcanized rubber hose 14 Molding groove part 18 First mouth mold 20 Second mouth mold 26 Through hole 28 Steam vulcanized can 30 Curved hose

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 21:00 105: 24 B29L 23:00

Claims (3)

[Claims] 1. An unvulcanized rubber hose is fitted and set along the molding groove of an outer mold having a molding groove for holding the unvulcanized rubber hose in a predetermined bent shape. In the method for manufacturing a curved hose by performing a predetermined axial length on at least one end of the unvulcanized rubber hose, the inner surface of the end is partially fitted to the inner surface of the unvulcanized rubber hose. A method for manufacturing a curved hose, comprising: mounting a mouth forming die in a fitting shape; and vulcanizing the unvulcanized rubber while maintaining the unvulcanized rubber in a bent shape using the outer die. 2. The unvulcanized rubber hose according to claim 1, wherein the mouth mold is attached to only one end of the unvulcanized rubber hose and the other end is open to the outside. A method for producing a curved hose, comprising vulcanizing with a steam can. 3. The unvulcanized rubber hose according to claim 1, wherein the corresponding mouth forming dies are attached to both ends of the unvulcanized rubber hose, and at least one of the mouth forming dies is provided inside and outside the unvulcanized rubber hose. And vulcanizing the unvulcanized rubber hose with a steam can.