JPH0538909Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> This invention relates to an extrusion coating head for high pressure rubber hoses.

<Conventional technology> The closest prior art to this idea is the
61-290011 ``Method of continuous vulcanization of hoses''. The drawing is cited as Figure 3. 1 is a rubber extruder, 2 is a braider, 3 is a rubber extruder, 4 is a resin extruder, 5 is a cooling tank, 7 is a vulcanization tank, 8 is a creasing machine for cutting the resin coating, 9 is a cooler, 10 is a resin peeling machine. In addition, A is a flexible core material shown in Fig. 4, B is a rubber tube, B' is a material with reinforcing fibers wrapped around it using a braider, C is a material with a rubber sheath attached thereon, and D is a material with a rubber jacket attached thereon. This shows a resin coating that suppresses the generation of bubbles during vulcanization. Finally, the flexible core material A is removed and the resin coating is peeled off to obtain a high pressure rubber hose.

In FIG. 3, the coating head 3a of the rubber extruder and the coating head 4a of the resin extruder 4 are directly related to this invention. FIG. 2 is an enlarged view of both heads 3a and 4a, showing their internal structure based on the conventional design.

The inside of each head 3a, 4a is evacuated so that air is not trapped between the inner tube B' wrapped with fibers and the rubber coating, and between the outer rubber tube C and the resin coating.
An air vent hole 11 and an outside air blocking seal 12 are provided.

<Problems to be solved by the invention> Tube C with rubber jacket coming out from rubber-covered head 3a
When entering the resin coated head 4a, the still soft outer covering rubber is deformed by the outside air barrier seal 12. Since the deformed rubber jacket is immediately covered with resin, the deformation is invisible to the operator. Therefore, the dimensional accuracy of the product after removing the resin coating is reduced.

When investigating the causes of the deformation of the outer cover rubber, it is found that there is a lack of installation accuracy of the external air barrier seal, dimensional accuracy of the seal itself, lack of uniformity of the seal, etc.

<Means for Solving the Problems> The extrusion coating head for high pressure rubber hose of this invention runs the inner tube of the high pressure rubber hose inside, coats the outside of the inner tube with outer rubber, and then coats the outer tube with rubber for vulcanization. In an extrusion covering head for a high-pressure rubber hose that covers a resin cover, between the rubber-covered head through which the inner pipe passes and the resin-covered head, the outer periphery of the outlet of the rubber-covered head and the outer periphery of the inlet of the resin-covered head are made airtight. It is characterized by the provision of a vacuum chamber for connection.

<Function> This idea connects the rubber-coated head and the resin-coated head with a vacuum chamber, and the outlet of the former and the inlet of the latter are opened into the vacuum chamber, so there is no need to pass the soft rubber coating through an outside air shield as in the conventional case. There is no need for the resin coating to be applied as is.

<Example> FIG. 1 shows an embodiment of this invention.

Inner tube B′ wrapped with reinforcing fiber is rubber-covered head 3
Figure 1 also shows that the outside air enters from the outside air blocking seal 12 at the inlet a and exits from the outlet of the resin-coated head 4a.
It is no different from the conventional one shown in Figure 2.

What has changed is that there is a vacuum chamber 1 between both heads 3a and 4a.
3 is provided, and this is the point where the outer circumference of the outlet of the head 3a and the outer circumference of the inlet of the head 4a are airtightly connected via an O-ring 14. In this example, a see-through window 15 made of glass or the like is provided on the side wall of the vacuum chamber 13,
Although monitoring and measurement are possible, the window 15 is not necessary if the amount of rubber press-fitted into the head 3a is properly controlled.

The inner tube B' that has entered the head 3a enters the vacuum chamber 13 surrounded by rubber that comes out from the outlet 16a from the extruder through the rubber press-in passage 16. and vacuum chamber 13
When it passes through the wide open inlet of the resin-coated head 4a and exits from the outlet, it becomes a resin-coated tube D surrounded by resin from the resin press-in passage 17 and the resin outlet 17a.

Since there are air vent holes 11 in both heads 3a and 4a, the one in the vacuum chamber 13 is omitted, or the O-ring 1
The shapes and dimensions of each part can be varied in various ways by changing the sealing material 4 to another sealing material, or by inserting the ends of each head into the vacuum chamber 13, etc., according to the well-known techniques of machine designers.

<Effects of the invention> This invention discovered a blind spot in the latest technology that prevents foaming during vulcanization by coating the outer periphery of the hose with resin in advance when manufacturing high-pressure rubber hoses, and demonstrated an effective and simple countermeasure.

The blind spot is that the outside air barrier seal at the inlet of the resin-coated head is immediately hidden by the resin coating even if the still soft rubber coating is deformed.

Even after grasping this problem, the first thing to consider is to either improve the precision of the external air barrier seal or to provide a cooling section between both heads. The former makes manufacturing difficult, and the latter makes the production line long and complicated.

This idea solved the problem in the simplest form, as it connected both heads with a vacuum chamber, eliminating the need for the soft rubber coating to pass through the seal.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of this invention, Fig. 2 is an explanatory diagram of the prior art, Fig. 3 is a plan view of a known example of high-pressure rubber hose manufacturing equipment including the part shown in Fig. This is an explanatory diagram showing the overlapping of the outer layers of a high-pressure rubber hose. In the figure, 3a is a rubber-coated head, 4a is a resin-coated head, and 13 is a vacuum chamber.

Claims (1)

[Scope of Claim for Utility Model Registration] In an extrusion covering head for a high-pressure rubber hose, which runs an inner pipe of the high-pressure rubber hose inside, covers the outer surface of the inner pipe with rubber, and then covers it with a resin cover for vulcanization. , A vacuum chamber is provided between the rubber-coated head and the resin-coated head through which the inner tube passes, which airtightly connects the outer circumference of the outlet of the rubber-coated head and the outer circumference of the inlet of the resin-coated head. Extrusion coated head for rubber hoses.