JPH0374900B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a method for manufacturing a bellows-reinforced rubber hose.

Note that such bellows-reinforced rubber hoses are often used as intercooler hoses for turbochargers in automobile engines.

(b) Conventional technology Conventionally, such bellows-reinforced rubber hoses (a part of which is shaped like a bellows to improve vibration absorption, and the rubber material itself is made of cloth, thread, etc. mixed in to increase its strength) have been used. The manufacturing method was as follows.

That is, after a rubber raw tube reinforced with a certain amount of material as described above is fitted onto a molding mandrel having a bellows part on the outer periphery, a bandage is generally wrapped tightly around the outer periphery of this rubber raw tube. The tightening force was used to vulcanize and mold the material to follow the shape of the mandrel.

In this respect, it is different from a bellows rubber hose made entirely of rubber, which can be formed by simply placing the original tube over a mandrel and creating a negative pressure by sucking the air inside.

(c) Problems to be solved by the invention By the way, there are the following problems with this bandage wrapping operation.

First, in order to wrap a piece of bandage tightly around the entire rubber tube continuously, it requires a considerable amount of force from beginning to end. As a result, this sometimes became loose, often resulting in poorly formed parts.

Next, if the bandage is tightly wrapped in this way, it will leave marks on the rubber tube, damaging its appearance. In particular, if the bandage becomes twisted and the tightening force becomes too high locally, the bandage will look like it has been dug out and its strength will be reduced.

(d) Means for Solving the Problems Therefore, the present invention involves fitting a rubber raw tube reinforced with a certain amount of material onto a molding mandrel having a bellows part on the outer periphery, and tightening the outer periphery of this rubber raw tube. In the manufacturing method of a bellows-reinforced rubber hose, the hose is vulcanized and molded to follow the outer peripheral shape of the mandrel, in which a rubber-like elastic body having a diameter slightly smaller than the product diameter is fitted onto the outer periphery of the rubber raw tube, and the rubber raw material is The basic method is to form the tube by the tightening force of the rubber-like elastic body when the tube is softened before hardening. The above-mentioned problems can be solved by optionally using a system in which the shaped elastic body is integral as a whole.

(e) Effect By taking such a method, if the raw rubber tube is placed in a vulcanizing can and vulcanized, it will temporarily become extremely soft before being vulcanized (hardened), and at that time, the rubber-like elastic material The tightening force acts to force the rubber tube to conform to the bellows shape of the inner mandrel.

(F) Examples Examples of the present invention will be described below with reference to the drawings. Fig. 1 is a sectional view showing the manufacturing state (before vulcanization) of the bellows-reinforced rubber hose according to the invention, and Fig. 2 is a similar sectional view. FIG. 3 is a partial cross-sectional view of the completed bellows-reinforced rubber hose.

First, a rubber raw tube 2 with constant reinforcement is fitted onto a mandrel 1 (a cylindrical tube is formed by forming a predetermined layer of a suitable core material (cloth, thread, etc.) between and on the surface of the unvulcanized rubber. ) is created using a conventionally well-known method.

Next, this is fitted onto the outer periphery of the mandrel 1 from one side.
In order to form the rubber raw tube 2 into a predetermined bellows shape, there is a bellows part 3 in the center and straight parts 4 on both sides of the bellows part 3.
is formed (therefore, the rubber raw tube 2 is
The final product will be finished following this shape).

Furthermore, when this is completed, a rubber-like elastic body 5 is fitted onto the outer periphery of the rubber tube 2.

By the way, the diameter of this rubber-like elastic body 5 is set to be slightly smaller than the product diameter (usually about 5 to 10% smaller) so as to properly tighten the fitted rubber tube 2. In addition, it is divided into appropriate widths in consideration of these functional aspects and ease of fitting operation.

That is, the one shown in Fig. 1 is divided into a straight part 4 and individual bellows parts 3, but in addition to this, the straight part 4 and an appropriate number of bellows parts 3 are integrated. Various things can be considered, such as things, or things in which all parts are integrated.

After the above operations are completed, this is placed in a vulcanizing can or the like and vulcanized.

However, at this time, since the rubber tube 2 is reinforced to a certain degree, simply fitting the rubber-like elastic body 5 around the outer periphery of the rubber tube 2 will cause the rubber tube 2 to have the shape of the mandrel 1. (See Figure 1).

Therefore, Fig. 4 is a graph showing the relationship between viscosity and time during vulcanization of rubber. Since rubber has the property of becoming extremely soft before being vulcanized (hardened), the structure described above in the rubber tube 2 is If the rubber-like elastic body 5 is fitted, molding can be performed using its tightening force.

That is, during a certain period of time (t1 to t2 in FIG. 4) before hardening, the rubber tube 2 softens, and the tightening force of the rubber-like elastic body 5 overcomes its shape-retaining force, causing the mandrel 1 to tighten. Tighten to follow the outer circumference shape. After this action, the rubber tube 2 is hardened and molded into a predetermined shape (see FIG. 2).

(g) Effects of the invention Since this invention is as described above,
The following effects can be expected.

First, the tightening force applied to the outer periphery of the rubber tube 2 to form it is the tightening force of the rubber-like elastic body 5, so a uniform tightening force is applied to the entire outer periphery, and
This can be said to be the same for any product. Therefore, the quality of the product including its shape and appearance improves and remains constant. In this regard, as mentioned above, there are variations in quality of conventional bandages.

Next, this operation does not require any force, since the rubber-like elastic body 5 having the above-described structure can be successively fitted onto the outer periphery of the rubber tube 2. Therefore, even a weak person can perform the work, and the work is easy and quick.

Furthermore, these things lead to process rationalization, time reduction, and cost reduction.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the manufacturing state (before vulcanization) of the bellows-reinforced rubber hose according to the present invention, Fig. 2 is a sectional view of the same (after vulcanization), and Fig. 3 is a partial cross-section of the completed bellows-reinforced rubber hose. FIG. 4 is a graph showing the relationship between viscosity and time in the addition of rubber. (Symbol), 1...Mandrel, 2...Rubber tube,
3... Bellows part, 5... Rubber-like elastic body.

Claims (1)

[Scope of Claims] 1. A rubber raw tube 2 reinforced with a certain amount of material is fitted onto a molding mandrel 1 having a bellows portion 3 on the outer periphery,
In the method for manufacturing a bellows-reinforced rubber hose in which the outer periphery of the rubber raw tube 2 is tightened and vulcanized to follow the outer peripheral shape of the mandrel 1, a rubber-like elastic body 5 having a diameter slightly smaller than the product diameter is attached to the rubber raw material. A method for producing a bellows-reinforced rubber hose, which is fitted onto the outer periphery of a tube 2, and is shaped by the tightening force of the rubber-like elastic body 5 when the raw rubber tube 2 is softened before hardening. 2 Rubber-like elastic body 5 according to claim 1
A method for manufacturing a bellows-reinforced rubber hose, characterized in that the hose is appropriately divided. 3 Rubber-like elastic body 5 according to claim 1
A method for manufacturing a bellows-reinforced rubber hose, characterized in that the hose is integral as a whole.