JP2001191339A - Mandrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate vulcanization and to enhance the production efficiency of a vulcanizing process. SOLUTION: An electric heater 10 is embedded in a mandrel 2 to raise the surface temperature of the mandrel 2 to vulcanizing temperature. Since the green rubber hose 1 applied to the surface of the mandrel 2 is directly heated from the inside in a close contact state, heat loss is reduced and a vulcanizing time is shortened to enhance production efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a mandrel used for manufacturing rubber hoses and the like.

[0002]

2. Description of the Prior Art In order to manufacture a rubber hose having a predetermined shape such as a three-dimensional curve, it is necessary to cover a mandrel provided in a predetermined shape with a raw material rubber hose before vulcanization. As the vulcanization method, there are a steam pot type shown in FIG. 3 and a hot stove type shown in FIG. In the steam cooker type, a plurality of mandrels 2 covered with a raw material rubber hose 1 are collectively attached to a carriage 3 prior to vulcanization, and the mandrels 2 are put into a vulcanizing furnace 4. The inside of the vulcanizing furnace 4 is filled with heated pressurized steam, and is vulcanized by heating in this environment for a predetermined time. Such vulcanization conditions are appropriately selected within a range of, for example, about 160 ° C., a pressure of about 5.5 kg / square centimeter to 200 ° C., and a pressure of about 20 kg / square centimeter, and usually require a vulcanization time of about 20 to 30 minutes. After vulcanization, the carriage 3 is taken out of the vulcanizing furnace 4 and cooled, and then the vulcanization hose is taken out of the mandrel 2 to obtain a product, and the mandrel 2 is turned to the next vulcanization cycle.

[0003] In the hot-air stove system shown in Fig. 4, a rotary line 6 is provided in a hot-air stove 5 filled with hot air of about 160 ° C, and the mandrel 2 is mounted on the rotary line 6 at an appropriate interval.
The raw material rubber hose 1 is put on the mandrel 2 and the hot air stove 5
By rotating the inside, after heating for about 30 minutes, it is partially taken out of the furnace, and vulcanized ones are sequentially taken out at a sampling station 7 provided here to form a product hose 8. Thereafter, the mandrel 2 from which the product hose 8 has been removed is covered with a new straight tubular raw material rubber hose 1 at the mounting station 9 and returned to the hot blast stove 5 again.

[0004]

By the way, in the case of the above-mentioned steam kettle method, the vulcanization step is a batch process, and cannot be made into a line, so that it becomes a bottom bottle of production efficiency, and it takes time to increase the steam pressure and Although the net vulcanization time for simply vulcanizing is relatively short, about 20 minutes at 160 ° C., because the time required for the mandrel to enter and exit from the steam kettle takes a long time, the molding cycle is It takes as long as 30 to 40 minutes. Therefore, if the net vulcanization time is to be shortened, the heating steam pressure must be greatly increased, and the production equipment becomes special, and in any case, it is difficult to further improve productivity. There's a problem.

[0005] In the case of a hot-air stove system, a line can be formed for batch processing of a steam pot system, but only about vulcanization requires about 30 minutes due to a small heat capacity. For this reason, although line production is possible, the production cycle cannot be shortened so much, a large installation space is required, complicated and expensive facilities are required, and the temperature rise in the hot blast stove 5 takes time. There is such a problem. Accordingly, an object of the present invention is to enable production on a line and to improve production efficiency to such an extent that it cannot be achieved by any of the steam cooker type and the hot stove type.

[0006]

In order to solve the above-mentioned problems, a mandrel according to the present invention is a mandrel which is inserted into the inside of a green rubber hose at the time of vulcanization of the green rubber hose. It is characterized by doing.

At this time, an electric heater can be built in as a heat source, or the inside can be hollow, and a heating fluid as a heat source can be put in the inside.

[0008]

The mandrel of the present invention generates heat by itself and can raise the surface temperature to about the vulcanization temperature. For this reason, the raw rubber hose on the mandrel is directly heated from the inside by the mandrel at a temperature near the vulcanization temperature. This heating is different from the conventional heating using steam or air as a medium, and can be performed in a close contact state, so that the vulcanization can be performed efficiently and quickly, and the vulcanization time can be shortened. The heat source of such a self-heating type mandrel can be easily controlled in temperature and can be heated in a short time. In addition, since the power source can be easily obtained from the line, it becomes extremely easy to use as a heat source.

Further, each mandrel can be provided on a production line, and instead of a conventional batch process, it is possible to perform a vulcanization process on a common line that is continuous with each of the preceding and subsequent mounting and extracting processes, and to perform a vulcanization process on the same line. Therefore, productivity is improved. In addition, this line is not isolated from the surroundings like a conventional hot stove, it can be installed in an open space, and the line can be shortened as much as the vulcanization time can be shortened, so it does not occupy a large installation space , The equipment is simple and cheap.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. It is to be noted that the same parts as those in the above-described embodiment use the common reference numerals. FIG. 1 shows a first embodiment using an electric heater. FIG. 1A shows a state at the start of vulcanization, and FIG. 1B shows a state after vulcanization is completed. In this figure, a mandrel 2 is a rod-shaped member that has been previously formed into a predetermined shape such as a three-dimensional curve, and is made of a suitable material such as a synthetic resin, metal, or ceramic. However, since the invention of the present application generates heat and heats the object covered with the heat, a metal made of metal having good thermal conductivity is preferable.

An electric heater 1 is provided inside the mandrel 2.
0 is built in, and an electric wire 13 extends from a base end portion 12 attached to the line 11 at one end in the longitudinal direction to the outside, and necessary electric power is supplied from a power source (not shown) via the electric wire 13 to heat the electric wire from the inside. By doing so, the surface temperature of the mandrel 2 is set to about the vulcanization temperature, for example, about 160 ° C. to 200 ° C.

The degree of heating can be appropriately adjusted by the composition of the raw rubber hose 1 to be vulcanized, and the temperature can be arbitrarily adjusted by a known external controller. The base 12 is fixed to a part of the line 11 by a nut 14.

As shown in FIG. 1A, when vulcanizing,
The raw material rubber hose 1 is put on the mandrel 2, and the electric heater 10 in the mandrel 2 is energized to generate heat. When the surface of the mandrel 2 reaches the vulcanization temperature, the raw material rubber hose 1 in close contact with the surface of the mandrel 2 is efficiently heated from the inside directly at a temperature close to the vulcanization temperature. For this reason, the vulcanization time can be significantly reduced as compared with the conventional case.

That is, since the raw material rubber hose 1 is in close contact with the surface of the mandrel 2, heat loss is small, and when the surface of the mandrel 2 is set to a general vulcanization temperature of about 160 ° C., the raw material rubber hose 1 Vulcanization can be performed in about 10 minutes if it is of the same order as the conventional example. 200 ° C
If it is raised to the extent, it can be vulcanized in about 5 to 7 minutes. That is, the vulcanization time can be reduced to about 1/3 to 1/6 of the conventional one, and as a result, the production cycle can be significantly reduced.

Incidentally, the general vulcanization temperature of about 160 ° C. can be extremely easily and quickly raised by the electric heater 10 built in the mandrel 2 of this embodiment. Also,
Although it is easy to raise the temperature to about 200 ° C., this temperature is of a level which is extremely difficult to raise in the conventional example.

The state after vulcanization is shown in FIG. 1B, and although there is little difference in appearance from FIG. 1A, the raw rubber hose mounted on the mandrel 2 has already been vulcanized and the product hose 8 It has become. Then, this is taken out, and then the raw material rubber hose is attached again and moved on the line.

The line 11 is, for example, an endless rotary type as shown in FIG. 4, and the steps of mounting, vulcanizing and extracting are continuously arranged on the line 11, and
As shown in (1), a mounting and extracting station is provided in a part of the line, where a raw rubber hose is mounted and a product hose after vulcanization is extracted. The product hose 8 after being extracted is sent to another line such as finishing.

As described above, while each mandrel 2 is individually attached to the line 11, the steps of mounting, vulcanizing and extracting can be continuously performed, and in particular, vulcanization is performed on the line. . For this reason, since continuous line work can be performed, production efficiency is remarkably improved.

This line 11 is different from the conventional hot stove,
An open space in a normal temperature environment that does not require any special isolation from the surroundings is sufficient, and the vulcanization time is significantly reduced, resulting in a significantly reduced line length. For this reason, it does not occupy much installation space, and can be installed at a low cost with a simple structure.

FIG. 2 shows a second embodiment in which the heat source is of a fluid type. The mandrel 2 has a fluid passage 2 having a hollow inside.
0, and the fluid passage 20 is opened at the base end portion 12, and the heating fluid is supplied from the external supply device as a heat source into the fluid passage 20 through the entrance 21.

This fluid is preferably a liquid, and heating oil, heating water or the like is appropriately used, and the temperature of the liquid can be adjusted by an external supply device. When the fluid is used as the heat source in this way, the heat generation temperature on the mandrel surface can be made uniform and stable, and furthermore, the running cost can be expected to be kept low.

The present invention is not limited to the above embodiments, but can be variously modified and applied. For example, it is not always necessary to eliminate external heating. A relatively high temperature can also be maintained. In this case, since heating or keeping the temperature can be performed from the outside in addition to the internal heating, the vulcanization can be made more efficient.
In addition, by maintaining the ambient temperature at a level that does not hinder the worker, the working environment can be significantly improved as compared with the conventional working environment.

[Brief description of the drawings]

FIG. 1 is a view showing a vulcanization step of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a view showing a conventional steam pot type vulcanization.

FIG. 4 is a view showing the same hot stove vulcanization.

[Explanation of symbols]

1: raw material rubber hose, 2: mandrel, 3: trolley, 8:
Product hose, 10: electric heater, 11: line, 20:
Fluid passage

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[Procedure amendment]

[Submission date] January 21, 2000 (2000.1.2
1)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B29L 23:00 B29L 23:00

Claims (3)

[Claims] 1. A mandrel to be inserted into the raw rubber hose when vulcanizing the raw rubber hose, wherein the mandrel self-heats the surface temperature to about the vulcanization temperature. 2. The mandrel according to claim 1, wherein an electric heater is incorporated as a heat source. 3. The mandrel according to claim 1, wherein the inside is hollow, and a heating fluid as a heat source is filled therein.