JPH01275127A - Method and device for manufacturing fiber-reinforced rubber hose - Google Patents

Abstract

PURPOSE:To improve the appearance of the surface of a hose and productivity in a manufacturing method in which an internal-surface rubber layer, a fiber-reinforced layer, the external- surface rubber layer and the resin coated layer is formed on the outer circumference of a mandrel in succession and the resin coated layer is removed after vulcanization by executing in the extrusion molding of the external-surface rubber layer and the resin coated layer in a reduced pressure. CONSTITUTION:An unvulcanized internal-surface rubber layer 31 is extrusion-molded on the outer circumference of a mandrel 30, and a fiber-reinforced layer 32 is formed on the outer circumference of the layer 31 by a braider, and wound on a drum. The wound layer 32 is forwarded from a feeder 1, and an unvulcanized external-surface rubber layer 33 is extrusion- molded on the outer circumference of the layer 32 by as rubber extruder crosshead 3 decompressed by a suction port 20. The extrusion-molded layer 33 is passed through a manifold 13 decompressed by a suction port 24, and sent to a resin extruded crosshead 7 under the state of the same decompression, and a resin coated layer 34 is formed on the outer circumference of the external-surface rubber layer 33. The hose is passed through a cooling water tank 8 and wound by a winding machine 10, and vulcanized by a vulcanizer. Lastly, the resin coated layer 34 is removed by a resin peeling machine, and the mandrel 30 is drawn out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a rubber hose having a fiber reinforced layer and an apparatus for manufacturing the same.

[Prior art] As a method for manufacturing an am reinforced rubber hose, Japanese Patent Application Laid-Open No. 52-1
:! As described in Japanese Patent No. 8978, an inner rubber layer is extruded around the outer periphery of a mandrel made of metal wire, plastic rod, etc., and a fiber reinforced layer made of nylon or the like is formed around the outer periphery of the inner rubber layer. There is a known method in which an outer rubber layer is extruded around the outer periphery of the rubber, a resin coating layer of a plastic such as polysulfone is extruded around the outer periphery of the outer rubber layer, the resin coating layer is vulcanized as it is, and then the resin coating layer is removed.

According to this method, the inner and outer circumferential surfaces of the rubber hose are restrained by the mandrel and the resin coating layer, respectively, without using the expensive and complicated leaded vulcanization method, so that the cross section of the hose can be made circular and shaped. This method has the advantage that a fiber-reinforced rubber hose with an excellent appearance and a uniform wall thickness can be maintained.

However, if you extrude the resin coating layer immediately after extruding the outer rubber layer, the outer rubber layer will enter the crosshead of the resin extruder while remaining very soft, so the vacuum backing at the inlet of the crosshead of the resin extruder will There were problems such as rubbing and damaging the outer rubber layer and clogging with the vacuum backing.

Conventionally, in order to eliminate scratches on the outer rubber layer, the outer rubber layer surface was naturally cooled or forcedly cooled until it became hard. However, since natural cooling at room temperature takes about 24 hours to harden the surface of the outer rubber layer, a method of forced cooling as shown in FIG. 4 is usually used. That is,
A hose with an inner rubber layer formed on the outer periphery of the mandrel and a fiber reinforced layer formed on the outer periphery of the inner rubber layer is sent from the hose feeder 1 to the rubber extruder Jj9.2, and is vacuumed from the suction port 11 at the rubber extruder crosshead 3. While pulling, an outer rubber layer is extruded around the outer periphery of the fiber reinforcing layer, and the rubber layer is forcibly cooled in a cooling water tank 4 as it is. Next, the cooled and hardened hose is transferred to a take-up machine 5.
is supplied to the resin extruder 6 through the resin extruder cross, and a resin coating layer is extruded on the outer periphery of the outer rubber layer while vacuuming from the suction r:I l 2 with the resin extruder cross rad 7, and the resin coating layer is forcedly cooled in the cooling water tank 8. After that, it passes through a take-up machine 9 and is wound up on a wind-up machine IO. However, even with this forced cooling, a lead time of about 6 hours was required from the formation of the outer rubber layer to the formation of the resin coating layer, and productivity was still poor.

Another way to eliminate scratches on the outer rubber layer is to make the inner diameter of the vacuum backing provided on the cross hose of the resin extruder 6 larger than the outer diameter of the outer rubber layer. The vacuum in the machine cross rad 7 is insufficient and air bubbles are generated between the outer rubber layer and the resin coating layer, resulting in a product that does not have a good appearance.Also, the two extrusion ports for resin and rubber are almost at the same position and concentric. It is possible to use a double-tube extruder with a double-opening opening, but if you simultaneously extrude rubber from the inner extrusion port and resin from the outer extrusion port, the extrusion pressures for each will be different, and the extrusion temperature of the resin will be different. is 240-34
Due to the high temperature of 0°C, the rubber burns or foams, making molding impossible.

[Problems to be Solved by the Invention] In view of the above-mentioned conventional circumstances, an object of the present invention is to provide a method and a manufacturing apparatus for manufacturing a fiber-reinforced rubber hose with good productivity while restraining the outer peripheral surface and having a good surface appearance. shall be.

[Means for Solving the Problems] In order to achieve this object, in the present invention, an inner rubber layer is formed on the outer periphery of the mandrel, a fiber reinforced layer is formed on the outer periphery of the inner rubber layer, and an outer surface is formed on the outer periphery of the tRM1 reinforcing layer. In a method for manufacturing a GI fiber reinforced rubber hose, in which a rubber layer is extruded, a resin coating layer is extruded around the outer periphery of the outer rubber layer, and the resin coating layer is removed after vulcanization, the outer rubber layer is extruded. The 4Iy feature is that the steps from 1 to 1 until extrusion molding of the resin coating layer are continuously carried out in a reduced pressure atmosphere.

A. The degree of pressure reduction in the invention direction is the same as usual <200~6
00a+mHg Yes.

The apparatus for manufacturing a fiber-reinforced rubber hose of the present invention also includes a rubber extruder crosshead attached to a rubber extruder that extrudes an outer rubber layer on the outer periphery of a fiber-reinforced layer applied to the outer periphery of the inner rubber layer; A resin extruder crosshead is attached to a resin extruder for extrusion molding a resin coating layer around the outer periphery of the resin extruder and has an inlet with a diameter larger than the outer rubber layer, and an outlet of the rubber extruder crosshead and an inlet of the resin extruder crosshead J in between?
It is characterized by comprising a cylindrical connecting pipe having a diameter larger than that of the outer rubber layer connected to the outer rubber layer, and a suction port provided in the connecting pipe and communicating with the inside of the connecting pipe and the hose passage of the crosshead of the resin extruder.

The formation and vulcanization of the inner rubber layer and the fiber reinforced layer, as well as the subsequent peeling off of the resin coating layer and pulling out of the mandrel, can be carried out using the same apparatus and method as conventional ones.

[Function] In the present invention, the extrusion molding of the outer rubber layer and the extrusion molding of the resin coating layer can be carried out under reduced pressure while evacuating each crosshead, as well as connecting the two crossheads with a vacuum. Connect with a pipe and move the rubber hose under reduced pressure, therefore.

Since the connecting pipe and the resin extruder crosshead can be communicated in a continuous reduced pressure atmosphere, there is no need to provide a vacuum backing at the inlet of the resin extruder crosshead, and the surface of the freshly extruded soft outer rubber layer can be directly connected to the resin extruder crosshead. It won't get scratched or clogged when entering the room.

If a viewing window is provided in the connecting pipe, it is possible to optically measure the outer diameter of the hose (the outer diameter of the outer rubber layer) from the outside.

Also, since the resin extruder crosshead reaches a high temperature of 240 to 340°C, a cooling device is installed between the two to suppress heat transfer to the connecting pipe. It is preferable to provide one.

[Example] Figure 1 shows a specific example of a fiber-reinforced rubber hose manufacturing device.
As can be seen from FIG. 2, which shows the main parts thereof, the rubber extruder cross rad 3 and the resin extruder cross rad 7 are connected through a connecting pipe 13 to form a connecting crosshead.

That is, as usual in the rubber extruder cross rad 11,
Crosshead body! Hose passage 1 is connected by a spindle holder 15 in 4 and a spindle 16 screwed to the tip of the spindle holder 15.
7 is configured horizontally.

A vacuum backing 19 is provided at the inlet 18 of the hose passage 17, and the inner diameter of the vacuum backing 19 and the outlet of the spindle 16 are made approximately equal to the outer diameter of the fiber reinforced layer of the hose, so that the hose passage 17 is connected from the suction port 20. It can be vacuumed. Further, a rubber supply path 21 for raw rubber supplied from the rubber extruder 2 is formed in the crosshead body 14, and a die 22 for extruding the outer rubber layer is fixed to the crosshead body 14 at the outlet thereof, and a spindle It opens concentrically with the exit of No. 16.

On the exit side of the rubber extruder cross rad 3, resin extruder cross rads 7 are provided at intervals, and a hose passage 1 consisting of a spindle holder 15' and a spindle 16° is provided.
The 7° center line is aligned with the center line of the hose passage 17 of the rad 3 to the rubber extruder cross. A resin supply path 23 is formed in the crosshead main body 14° of the resin extruder cross rad 7, and its outlet is concentrically opened at the outlet of the spindle 16' by a die 22°. Further, a heater for heating the hose to be supplied may be provided around the inlet side of the spindle holder 15'.

The inlet of RAD 7 to the resin extruder cross has an inner diameter larger than the outer diameter of the outer rubber layer and is not equipped with a vacuum backing, and is connected to the rubber extruder cross]・To the exit of RAD 3 and the resin extruder cross Between the inlets of the rad 7, there is a cylindrical tube with a diameter larger than the outer rubber layer of the hose (outer diameter 100~300a11,
A connecting pipe 13 having a length of 300 to 900 + a+) is connected, and the inside thereof communicates with a hose passage 17' of the rad 7 to the resin extruder cross.

The connecting pipe 13 is provided with a suction port 24, and the inside thereof and the hose passage 17' of the resin extruder crosshead 7 communicating therewith can be evacuated. Further, the connecting pipe 21 is provided with a see-through window, so that the outer diameter of the outer rubber layer of the hose passing through the interior can be optically measured.

Furthermore, a cooling bag (¥125) is provided between the connecting pipe 13 and the resin extruder cloth to the rad 7, which dissipates the heat from the rad 7 to the resin extruder cross which becomes hot, thereby preventing the connecting pipe 13 from heating. It looks like this.

Next, using this equipment, the rubber hose shown in FIG. 3 was manufactured as follows. Namely, 1. As usual, an unvulcanized inner rubber layer 31 was continuously extruded around the outer periphery of a mandrel 30, a fiber reinforced layer 32 was formed around the outer periphery of the inner rubber layer 31 using a braiding machine, and the material was once wound around a drum. Next, this hose is sent out from the feeder 1 as shown in FIG. The vulcanized outer rubber layer 33 was extruded. This hose passes through the connecting pipe 13 whose pressure is reduced to 200 to 400 rxHg at the suction port 24, and is sent to the resin extruder crosshead 18 which is under the same reduced pressure. The resin-covered Vn layer 34 was formed by extrusion molding at ~280°C. After that, this hose has 4P cooling water! It was wound up with a winding filO through 8 and vulcanized at 160° C. for 60 minutes in a vulcanizer. By vulcanization, a portion of the inner rubber layer 31 bulged into the outer rubber layer 33 to form a hardened bulging convex portion 35, and both layers were firmly adhered. Finally, the resin coating layer 34 was removed using a resin peeling machine, and the mandrel 30 was extracted by applying water pressure.

Table 1 below summarizes the materials, quality, and outer diameter from the inner rubber layer to the resin coating layer.

Inner rubber layer Fu7 base rubber (11,0) N B R
(17,2) m fiber reinforced layer hini on (12,0)
PET (19,5) outer rubber layer hydrish rubber (1
3,7) E P D M (22,5)
muti covered)! Polymethylpentene (1
7,7) Polymethylpentene (28,5) For each sample obtained, the adhesive force between the fiber reinforced layer and the outer rubber layer was measured, and the appearance of the outer rubber layer was observed. For comparison, J1! f! under the same conditions except that a conventional device that does not use a tube is used! The adhesive strength of the A-built rubber hose made of the same material was also measured and the appearance was observed. The obtained results are shown in Table tS2 along with the lead time from the formation of the outer rubber layer to the formation of the resin-covered Yn layer.

From this result, it can be seen that although there is no difference in adhesive strength, the hose of the present invention is superior in terms of hose appearance and leave time.

In addition, it is also possible to carry out the entire process from mandrel feeding to vulcanization in a continuous line.

It goes without saying that the vulcanization can be carried out using UHF or the like alone or in combination in addition to the vulcanizer.

[Effects of the Invention] According to the present invention, a fiber-reinforced rubber hose that is vulcanized while its inner peripheral surface and outer peripheral surface are restrained by a mandrel and a resin coating layer, respectively, can be produced in an excellent appearance with no scratches on the surface. Moreover, it can be manufactured with high productivity.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing a specific example of the device of the present invention, and FIG. 2 is a sectional view of the main parts thereof. FIG. 3 is a partial sectional view of a fiber-reinforced rubber hose manufactured by the method of the present invention, and FIG. 34 is a schematic side view of a conventional device. ■...Feeding machine 2...Rubber extruder 3...Rubber extruder cross head 4.8...Cooling water tank 6...Resin extruder 7...Resin extruder cross head 1o...・Rewinder 11.12.
20.24...Suction port 13...Connecting pipe 14,l 4'...Crosshead body 15.15'...Spindle holder 16.16
'... Spindle 17... Port passage 19...
Vacuum backing 21...Rubber supply path 22.22'.
...Dice 23...Resin supply path 25...Cooling device 3o...Mandrel 31...Inner rubber layer 32.
...Fiber reinforcement layer 33...Outer rubber layer 34...Resin coating layer 35...Bulging convex portion

Claims (3)

[Claims] (1) An inner rubber layer is formed on the outer periphery of the mandrel, a fiber reinforced layer is formed on the outer periphery of the inner rubber layer, an outer rubber layer is extruded on the outer periphery of the fiber reinforced layer, and then the outer periphery of the outer rubber layer is coated with resin. In a method for manufacturing a rubber hose in which the resin coating layer is removed after extrusion molding and vulcanization, the steps from extrusion molding of the outer rubber layer to extrusion molding of the resin coating layer are continuously carried out in a reduced pressure atmosphere. A method for producing a characteristic fiber-reinforced rubber hose. (2) A rubber extruder crosshead attached to a rubber extruder extrudes an outer rubber layer around the outer periphery of the fiber reinforced layer applied to the outer periphery of the inner rubber layer, and a resin coating layer is extruded around the outer periphery of the outer rubber layer. A resin extruder crosshead attached to the resin extruder and equipped with an inlet having a diameter larger than the outer rubber layer, and a resin extruder crosshead having a diameter larger than the outer rubber layer connecting between the outlet of the rubber extruder crosshead and the inlet of the resin extruder crosshead. A manufacturing device for a fiber-reinforced rubber hose, comprising a cylindrical connecting pipe and a suction port provided in the connecting pipe and communicating with the inside of the connecting pipe and the hose passage of a crosshead of a resin extruder. (3) The apparatus for manufacturing a fiber-reinforced rubber hose according to claim (2), further comprising a cooling device between the connecting pipe and the crosshead of the resin extruder.