JPH0477215A - Continuously vulcanizing method of rubber hose - Google Patents

Abstract

PURPOSE:To remove the deformation or the foaming of the outer peripheral surface of a covering outer tube due to the swelling of reinforcing yarn by vulcanizing simultaneously the inside of an unvulcanized hollow tube and the outside of a covering outer tube under pressure in vulcanizing process. CONSTITUTION:Rubber material is continuously extruded into tubular shape from a first extruding machine 1 in first extruding process, and a hollow inner tube 11 if formed. A reinforcing yarn 121 is wound on the outer peripheral surface of the hollow inner tube 11 in yarn-winding process successively, and a yarn-wound layer 12 is formed. Then is second extruding process, rubber material is continuously extruded on the outer periphery of the yarn-wound layer 12 from a second extruding machine 3, and a covering outer tube 13 is formed. In vulcanization process, the inside of the hollow inner tube 11 and the outside of the covering outer tube 13 are simultaneously vulcanized under pressure. Thus, since the inside of the hollow inner tube 11 and the outside of the covering outer tube 13 are simultaneously pressurized, the yarn- wound layer 12 is pressurized from its outside, whereby the expansion of the air contained in the reinforcing yarn 121 of the yarn-wound layer 12 is suppressed, and the swelling or the peeling of the reinforcing yarn 121 is removed, and further the deformation or the foaming of the outer peripheral surface of the covering outer tube is removed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a continuous vulcanization method for rubber hoses.

[Prior Art] As shown in FIG. 4, a conventional continuous vulcanization method for a rubber hose includes a first extrusion process in which a rubber material is continuously extruded into a tube shape from a first extruder 1a to form a hollow inner tube 11a. A reinforcing thread 120a is provided on the outer peripheral surface 110a of the hollow inner tube 11a.
a thread-winding step of forming a thread-wound layer 12a;
a second extrusion step in which the coated outer tube 13a is continuously extruded from a, and the hollow inner tube 11a and the coated outer tube 13a are heated in a heating furnace 5.
A method of performing a vulcanization step of vulcanizing by a is known.

[Problems to be Solved by the Invention] According to the conventional continuous vulcanization method for rubber hoses, in the vulcanization process, the air contained in the thread-wound layer 12a serving as the reinforcing layer expands due to heat, causing swelling or reinforcing. In some cases, a problem may occur in which the thread 120a separates from the outer peripheral surface 110a of the hollow inner tube 11a.

In order to eliminate such problems, a protective coating layer such as lead or horse chestnut resin is coated and formed on the outer periphery of the thread-wound layer 12a and the sheathed outer tube 13a, thereby preventing the thread-wound layer 12a from peeling off, Swelling and reinforcing thread 120
This suppresses swelling and foaming of the outer sheathed tube 13a caused by peeling etc.
(See Publication No. 1).

In the case of the conventional continuous vulcanization method for rubber hoses, prior to vulcanization of the rubber hose, there is a step of coating the outside of the outer tube 13a with a protective coating layer, and a step of removing the protective coating layer after vulcanization. This required a large amount of man-hours and reduced productivity.

An object of the present invention is to provide a continuous vulcanization method for a rubber hose that solves the above-mentioned conventional problems.

[Means for Solving the Problems] The continuous vulcanization method for a rubber hose of the present invention provides a first method for vulcanizing a rubber material.
a first extrusion step in which a hollow inner tube is continuously extruded into a tube shape from an extruder; a thread winding step in which a reinforcing thread is wound on the outer peripheral surface of the hollow inner tube to form a thread-wound layer; a second extrusion step in which a rubber material is continuously extruded from a second extruder to form a coated outer tube; and a curing step in which the hollow inner tube and the coated outer tube are vulcanized; The process is characterized in that the inside of the unvulcanized hollow inner tube and the outside of the covered outer tube are simultaneously pressurized and vulcanized.

In the continuous vulcanization method for a rubber hose of the present invention, the first extrusion step, the thread winding step, and the second extrusion step can in principle be the same as conventional methods.

The characteristics of the present invention reside in the thread winding process and the vulcanization process.

In the thread winding process, when winding the reinforcing thread around the outer circumferential surface of the hollow inner tube,
The thread-wound layer can be formed while applying a constant gas pressure inside the hollow inner tube. In this case, since the hollow inner tube that is continuously extruded into a tube shape in the first extrusion step is soft, it can be prevented from deforming toward the center due to the tightening pressure when the thread is wound around its outer circumferential surface.

In the vulcanization process, when vulcanizing the hollow inner tube and outer jacket tube,
It is possible to vulcanize the inside of the hollow inner tube and the outside of the outer jacket tube while simultaneously applying pressure.

The pressure of the pressurization, that is, the pressure value of the internal pressure applied to the inside of the hollow inner tube and the external pressure applied to the outside of the sheathed tube, may be the same internal pressure and external pressure, or one in which one of them is increased. It is also possible to control the internal and external pressures as necessary.

The pressure value of the pressurization can be set variously depending on the purpose.

[Operations and Effects of the Invention] In the continuous vulcanization method for a rubber hose of the present invention, in the first extrusion step, the rubber material is continuously extruded from the first extruder into a tube shape to form a hollow inner tube. In the subsequent thread winding process, a reinforcing thread is wound on the outer peripheral surface of the hollow inner tube to form a thread-wound layer. Thereafter, in a second extrusion step, a coated outer tube is formed by continuously extruding the rubber material from a second extruder around the outer periphery of the thread-wound layer.

In the vulcanization step, the inside of the hollow inner tube and the outside of the jacketed outer tube are simultaneously pressurized and vulcanized.

The rubber hose obtained by the above process is simultaneously pressurized inside the hollow inner tube and outside the coated outer tube during vulcanization. Therefore, by applying pressure from the outside, the thread-wound layer can suppress the thermal expansion of the air contained in the reinforcing threads, preventing the reinforcing threads from swelling or peeling, and can also prevent the reinforcing threads from swelling and peeling. Deformation and foaming of the outer circumferential surface of the outer tube can be prevented. In addition, if pressure is applied only from the outside of the jacketed outer tube, the pressure is simultaneously applied from the inside of the hollow inner tube, which is easily touched by the rubber hose, so that the above-mentioned collapse can be prevented.

Furthermore, according to the method of the present invention, there is no need to use a mandrel inside the hose during vulcanization after forming the hollow inner tube.
In addition, there is no need to vulcanize the outer peripheral surface of the outer tube of the rubber hose with some kind of expansion-preventing cylindrical body, which saves time and labor costs during the vulcanization process. It becomes possible to reduce the

"Example" The continuous vulcanization method for a rubber hose of the present invention is shown in Figs. 1 and 2.
This will be explained based on FIG.

In the continuous vulcanization method of a rubber hose of this embodiment, the rubber hose shown in FIGS. 2 and 3 is formed using the apparatus shown in FIG. The rubber hose 10 formed by this continuous vulcanization method consists of a hollow inner tube 11, a thread wound layer 12 formed on the outer periphery of the hollow inner tube 11, and a covered outer tube 13 formed on the outer periphery of the thread wound layer 12. It has a layered structure.

The continuous vulcanization method of the rubber hose of the embodiment includes a first extrusion step, a thread winding step, a second extrusion step, and a vulcanization step.

In the first step, the rubber material of the enclosure is continuously extruded from the extrusion head section 14 of the first extruder 1 into a tube shape to form the hollow inner tube 11 . The conditions in the first extrusion step are:
Extrusion pressure 200-350, 076 extrusion speed 5-1
The speed is set to 0m/min.

In the thread winding process, two reinforcing threads 121 are alternately wound around the outer circumferential surface 110 of the hollow inner tube 11 using two blender devices 2 to form a mesh thread-wound layer 12. In the thread winding process, the reinforcing thread 121 in the thread 1 has a thickness of 1000 to 2000 b.
, the winding speed is 5 to 10 m/min.

In the second extrusion step, the outer peripheral surface 120 of the thread-wound layer 12 is continuously extruded from the extrusion head 34 of the second extruder 3 to form the outer tube 13. The conditions in the second extrusion step are an extrusion pressure of 200 to 350
kCl/cri, extrusion speed 5-10 m/min.

After completing the second extrusion process, the hollow inner tube 11 and the thread-wound layer 1 are
2. Unvulcanized rubber hose 1 consisting of three layers of jacketed tube 13
0A is formed.

Prior to the subsequent vulcanization process, this rubber hose 10A is transferred into the pressurizing cylinder section 4 having the first pressurizer 40, and
From one end side of the hollow inner tube 11 extruded from the extrusion head 14 of the extruder 1, a pressure of 2 to 5 is applied from the second pressurizing machine 41 to the inside thereof.
Atmospheric pressure air is introduced, and at the same time, the first pressurizer 40 is inserted into the pressurizing cylinder part 4 with the outer peripheral surface of the distal end of the jacketed tube 13 and the end of the pressurizing cylinder part 4 sealed by the seal part 43. 2-5 more
Air pressure at a pressure of kg/Cl7i is introduced. The unvulcanized rubber hose IOA is housed in the cylindrical heating furnace 5 together with the pressurized cylinder part 4, and the hollow inner tube 11
While simultaneously pressurizing the inner circumferential surface 111 of the outer circumferential surface 111 and the outer circumferential surface 130 of the jacketed tube 13 with a gas pressure of 2 to 5 kg/cm, the heating temperature was 1.
Vulcanization is performed under the conditions of 70° C. and heating time of 15 minutes while moving at a speed of 5 to 10 m/min, and the tip of the rubber hose 10 that has been vulcanized is moved to a take-off device 6 having a pair of take-off rollers 60, 60. The film is taken up by the winding device 7, deformed into a shape suitable for winding, and then wound up to a certain size by the winding device 7.

As described above, according to the continuous vulcanization method of the rubber hose of the present embodiment, the inner circumferential surface 111 of the hollow inner tube 11 and the outer circumferential surface 130 of the sheathed outer tube 13 are The hollow inner tube 11 of the reinforcing thread 120 is formed by thermal expansion of the air mixed and contained in the thread wound layer 12 which becomes the reinforcing layer.
Partial peeling from the outer circumferential surface 110 of the rubber and foaming of the rubber due to the influence of heat can be physically prevented by the force exerted by pressurization. As a result, vulcanized rubber hoses 10 of good quality can be continuously produced using a simple device. Furthermore, since there is no need to use the mandrel used to prevent the unvulcanized rubber hose 10A from collapsing during vulcanization, the work step of inserting the mandrel into the unvulcanized rubber hose 10A can be omitted, reducing work costs. can be lowered.

[Brief explanation of the drawing]

1 to 3 are explanatory diagrams for explaining the continuous vulcanization method for rubber hoses of this embodiment, and FIG. 1 is a schematic diagram of the entire apparatus for carrying out the continuous vulcanization method for rubber hoses. Figure 2 shows
FIG. 2 is a side view showing a cross section of a part of the rubber hose manufactured in this example. FIG. 3 is a cross-sectional view showing a cross-section of a rubber hose also manufactured in this example. FIG. 4 is an explanatory diagram illustrating a conventional continuous vulcanization method for rubber phosphorus. 1... First extruder 2... Blader device 3...
・Second extruder 4...Pressure local part 5...Heating furnace
10... Rubber hose 11... Hollow inner tube 10A unvulcanized rubber hose 12... Thread wound layer 13... Covered outer tube Patent applicant Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] (1) A first extrusion step in which a rubber material is continuously extruded into a tube shape from a first extruder to form a hollow inner tube; and a thread winding step in which a reinforcing thread is wound on the outer peripheral surface of the hollow inner tube to form a thread-wound layer. a second extrusion step of continuously extruding a rubber material from a second extruder to the outer periphery of the thread-wound layer to form a coated outer tube; a vulcanization step of vulcanizing the hollow inner tube and the coated outer tube;
A continuous vulcanization method for a rubber hose, characterized in that at least in the vulcanization step, the inside of the unvulcanized hollow inner tube and the outside of the unvulcanized outer tube are vulcanized while pressurizing simultaneously.