JPH0136408B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method and apparatus for pressure vulcanization of long rubber products such as rubber hoses.

Pressure vulcanization of long products such as rubber hoses and weather strip rubber has traditionally been an essential element in maintaining high quality such as vulcanization quality and dimensional accuracy. Therefore, it is necessary to compression mold the unvulcanized rubber material into the cavity shape of the mold by closing the split mold, and then finish the vulcanization while maintaining the pressure. Pressure molding of long products such as rubber hoses requires a mold that is longer than the length of the molded product.
In order to press this mold, it was necessary to use several compression presses lined up or a long compression press. For example, in the conventional pressurized vulcanization of a rubber hose, Fig. 1 shows the front view, and Fig. 2 shows the first
An apparatus shown in the AA cross-sectional view in the figure was used.
This device consists of five columnar split molds 101 having a cavity equal to the outer diameter of the rubber hose along the central axis.
It is pressed with a compression press 102 on a stand. In this way, five compression presses were required to pressure-cure one rubber hose, and it was necessary to maintain the pressure of the compression presses for the time required to vulcanize the rubber. This resulted in problems such as very expensive equipment and low productivity.

The present invention has been made in view of the above-mentioned problems, and a first object thereof is to provide a pressure vulcanization method and apparatus that do not require a special compression press. A second object of the present invention is to provide a pressure vulcanization method and apparatus that are highly productive and highly efficient.

In the present invention, the mold is columnar, and the inner wall surface of the cylindrical heating device presses the outer peripheral surface of the columnar mold to maintain the compression pressure of the pressurized rubber material in the cavity of the mold. The goal is to achieve the following.
That is, the pressure vulcanization method of rubber of the present invention includes a step of inserting an unvulcanized rubber material into a columnar mold having a tunnel-shaped cavity and divided into two or more parts parallel to the axis; A step of press-molding an unvulcanized rubber material by pressing each split mold from the outer periphery of the mold to close the mold, and inserting the mold into a cylindrical heating device; and an inner wall surface of the cylindrical heating device. The step of vulcanizing the unvulcanized rubber material of the mold by transmitting heat to the mold while holding each divided mold of the mold, the mold is taken out from the cylindrical heating device, and the mold is molded from its cavity. This method is characterized by comprising a step of taking out a vulcanized rubber molded product.

Further, the rubber pressure vulcanization apparatus of the present invention has a tunnel-shaped cavity, and includes a columnar mold that is divided into two or more parts parallel to the axis, and a tunnel-shaped mold that can be inserted when the mold is closed. A cylindrical heating device that has a vulcanization chamber and holds a mold on its inner wall surface, and a pressurizer that presses a split mold from the outer periphery of the mold provided near the open end of the vulcanization chamber to close the mold. The device is characterized by comprising a mold carrying-in/out device for carrying a closed mold into a vulcanization chamber of a cylindrical heating device and carrying it out.

The method and apparatus of the present invention do not require a conventional compression press because the mold is pressed with a cylindrical heating device. Therefore, the device becomes smaller and cheaper. Moreover, it becomes possible to combine a plurality of cylindrical heating devices, and the time required for vulcanization can be used effectively.

It should be noted that since the method and apparatus of the present invention belong to the same technology, hereinafter, unless otherwise specified, they will be collectively described as the present invention and will be described by way of examples.

The mold 1 used in the embodiment of the present invention has a columnar appearance as shown in FIGS. 3 to 5, and its cross section is divided into two along the central axis as shown in FIGS. 4 and 5. It consists of an upper mold 11 and a lower mold 12. The cavity 13 is formed at the center of the dividing surface of the upper mold 11 and the lower mold 12, and is a tunnel-like through hole with a circular cross section. Rubber stripping grooves 14, 14 are provided on the dividing surface of the lower mold 12 in parallel with the cavity 13 at a certain distance.
is provided. The upper surface of the upper mold 11 and the lower surface of the lower mold 12 are slightly shaved so that the planes 15 and 16 are parallel to each other.
It is becoming. Further, each end surface of the entire mold 1 in which the upper mold 11 and the lower mold 12 are stacked is protruded in a circular shape.

The cylindrical heating device 2 includes a pressurizing cylinder 21 made of a steel pipe, which is cylindrical and has a funnel-shaped opening on the inlet side, and a band heater 22 provided around the outer periphery of the pressurizing cylinder 21. A space formed by the inner wall surface of the pressurizing cylinder 21 becomes a vulcanization chamber 23. The diameter of the vulcanization chamber 23 is slightly larger than the maximum cross-sectional diameter of the mold 1, and the mold 1 is inserted into this vulcanization chamber 23 during vulcanization, and the inner wall of the pressurizing cylinder 21 presses the mold 1. Each upper mold 11 and lower mold 12 are maintained in a closed state, and heat is conducted to the mold 1.

The pressure device 3 is provided at the entrance of the cylindrical heating device 2, and includes a frame 31 and a pair of pressure rollers 32 and 33 provided opposite thereto. This pressurizing device 3 is connected to the upper mold 1 of the mold 1 as shown enlarged in FIG.
The upper mold 11 and the lower mold 12 are closed by sandwiching the flat surface 15 of the mold 1 and the flat surface 16 of the lower mold 12 with pressure rollers 32 and 33. The distance between the pressure rollers 32 and 33 is adjusted to the extent that the mold can be press-fitted into the vulcanization chamber 23 of the cylindrical heating device 2.

The mold loading/unloading device 4 includes hydraulic devices 41 and 4 disposed coaxially with the pressurizing tube 21 at each open end of the pressurizing tube 21.
Consists of 2. These hydraulic devices 41, 42 include hydraulic cylinders 411, 421 and pistons 412, 422.
It becomes more. At the other ends of the pistons 412 and 422, there is provided an abutment tool 41 having an inclined ring-shaped tip surface that expands toward the open end similar to the inner surface of the funnel.
3,423 are combined. The hydraulic device 41 on the left in FIG.
33 to be inserted into the pressurizing cylinder 21. Also, in Figure 3, the hydraulic system 4 on the right side
Reference numeral 2 denotes a carry-out device for pushing out the mold 1 inside the pressurizing cylinder 21.

The rubber pressure vulcanization apparatus of this embodiment has the above configuration.

In this device, the upper mold 15 of the mold 1 is opened, and the lower mold 1
A rubber hose material is placed in the cavity 13 of No.6. This rubber hose material is the same as the conventional one, with a mandrel made of rod rope covered with an inner rubber material.
Fibers are wrapped around it, and an outer rubber material is coated on top of it. The volume of this rubber hose material is set to be slightly larger than the volume of the cavity 13 of the mold 1. The relationship between the volume of this material and the volume of the cavity 13 is the same as the conventional one. Note that both ends of the cavity 13 in this embodiment are open, but this is also the same as in the conventional case, and although there are portions at both ends that are not pressurized slightly, there is no problem overall.

After placing the rubber hose material, the upper mold 15 is placed over the lower mold 16. Next, as shown in FIG. 3, this mold 1 is coaxially arranged on the inlet side of the pressurizing cylinder 21,
The mold 1 is press-fitted between the rollers 32 and 33 of the pressure device 3 by the hydraulic device 41 . As explained earlier, both ends of the mold 1 protrude with the same sloped ring-shaped surfaces as the outer surface of the rotunda, so the ends of the mold 1 easily fit between the rollers 32 and 33. , as shown in FIG.
The upper mold 11 and lower mold 12 are pressed in the direction in which they are brought together. Note that the contact tool 4 is also attached at the other end of the mold 1.
13 presses the upper mold 11 and the lower mold 12 in the closing direction. When the upper mold 11 and lower mold 12 of the mold 1 are pressed and moved in the closing direction, the rubber material in the cavity 13 is pressurized and compressed. While there is a considerable gap between the dividing surfaces of the upper mold 11 and the lower mold 12, the excess rubber material is removed from the lower mold 1 by the distance between the mating surfaces.
It is pushed out into the groove 14 of No. 2. When the upper mold 11 and the lower mold 12 are brought close enough to each other that the excess rubber material is extruded and a large pressure is required for the rubber material to pass through, there is a balance, the pressure acts on the rubber material, and the pressure is maintained. be done. The pressurizing device 3 presses the mold 1 to the extent that the above-described desired pressure is applied to the upper mold 11 and the lower mold 12. In this state, the mold is pushed by the hydraulic device 41 and sequentially passes through the pressurizing device 3 from one end thereof into the vulcanization chamber 23 of the pressurizing cylinder 21 of the cylindrical heating device 2 . Since the entrance of the vulcanization chamber 23 also has an enlarged funnel-shaped opening, the tip of the mold 1 enters the vulcanization chamber 23 relatively smoothly. Since the upper mold 11 and the lower mold 12 of the mold 1 are prevented from opening on the inner wall surface that partitions the vulcanization chamber 23, the pressure of the mold 1 is maintained, and the pressurization of the rubber hose material is also maintained. When the mold 1 is completely inserted into the vulcanization chamber 23, the piston 412 of the hydraulic device 41 is driven in the opposite direction. The mold 1 in the vulcanization chamber 23 receives heat from the band heater 22 of the cylindrical heating device 2 through the pressurizing cylinder 21 and is heated.
The heat is transferred to the rubber material and the rubber is vulcanized.
Note that the pressure inside the cavity 13 increases due to thermal expansion of the rubber hose material. When the vulcanization of the rubber is completed after a certain period of time has elapsed, the mold 1 is pushed in the opposite direction by the hydraulic device 42 for carrying out and is pushed out of the vulcanization chamber 23. Thereafter, the upper mold 11 is opened, and the molded and pressure-vulcanized rubber hose is taken out from the cavity 13. A rubber hose is thus obtained. A rubber hose material is again placed in the mold 1 and pressure vulcanized in the same manner.

In this embodiment, the apparatus is provided with one mold 1 and one pressurizing cylinder 21, but since the apparatus of the present invention does not require a compressor such as a hydraulic press, FIGS. As shown in the figure, a plurality of pressure cylinders 21 may be provided, or a plurality of molds 1 may be inserted into one pressure cylinder 21'.

The device shown in FIG. 7 uses a plurality of cylindrical heating devices 2 shown in FIG. 3, and is fixed to the side circumference of a rotary wheel 5 parallel to the axis at equal intervals. This rotary wheel 5 consists of a rotary shaft 52 driven by a motor 51 and a support frame 53 fixed to the rotary shaft 52.
A cylindrical heating device 2 is fixed to the outer periphery of the tube. Since this device requires a relatively long time to vulcanize the rubber, the rotary wheel 5 rotates once in synchronization with the vulcanization time, and one cylindrical heating device 2 is used for vulcanization. During this time, the product vulcanized in the mold in the other cylindrical heating device 2 is taken out and the materials are placed.

The apparatus shown in FIG. 8 is characterized by the use of a long cylindrical heating device 2' and by the use of a single hydraulic device 41 for carrying in and out of molds. This cylindrical heating device 2' has two molds 1a and 2a inserted at all times, and when the third mold 3a is inserted from the entrance, the first
The mold 1a is extruded from the outlet at the other end. A connecting tool 20 is interposed between the mold 1a and the mold 2a. This connecting tool 20 has a short cylindrical shape and has an inclined ring-shaped end surface with openings at both ends expanding like a funnel toward the outlet. Since the tips of the molds 1a and 2a are pushed into the open end of each of the connecting tools 20, the upper and lower molds of the molds 1a and 2a are compressed in the closing direction, and the molds are closed on the inner wall surface of the heating cylinder 21'. It is possible to reduce the pressing pressure by that amount. The upper mold of the mold extruded from the heating cylinder 21' is opened, and the rubber product 6 is taken out from the mold 1 and sent to the mold storage frame 7.

In the above-described embodiment, only a two-part mold consisting of an upper mold and a lower mold is shown as the mold 1, but the mold is not limited to a two-part mold, and a three-part mold or a four-part mold can be used.

As for the pressure device, although a roller is used in the embodiment, the pressure device is not limited to a roller.
For example, a wrapper-shaped guide may be formed at the opening end of the heating cylinder on the inlet side, and the mold may be inserted into the heating cylinder while the mold is closed by a hydraulic device. In this case, this guide and the hydraulic device constitute a pressurizing device.

[Brief explanation of drawings]

Figures 1 and 2 show a conventional pressure vulcanization apparatus for long objects, with Figure 1 being a front view thereof, Figure 2 being a sectional view taken along the line A-A in Figure 1, and Figures 3 to 3. FIG. 6 shows a pressure vulcanization apparatus according to an embodiment of the present invention, FIG. 3 is a longitudinal sectional view thereof, and FIG. 4 is an enlarged sectional view of a mold taken along the line B-B in FIG. 3. , FIG. 5 is an enlarged sectional view of the pressurizing device, which is a sectional view taken along line C-C in FIG. 3, and FIG. 6 is an enlarged sectional view of the cylindrical heating device, which is a sectional view taken along line DD in FIG. FIG. 7 is a sectional view of a rubber pressure vulcanization apparatus of another embodiment, and FIG. 8 is a sectional view of a rubber pressure vulcanization apparatus of still another embodiment. In the figure, numeral 1 is a mold, 2 is a cylindrical heating device, 3 is a pressurizing device, and 4 is a mold loading/unloading device.

Claims (1)

[Claims] 1. A step of inserting an unvulcanized rubber material into the cavity of a columnar mold having a tunnel-shaped cavity and divided into two or more parts parallel to the axis, each from the outer periphery of the mold. A step of press-molding an unvulcanized rubber material by pressing the divided mold to close the mold and inserting the mold into a cylindrical heating device, each division of the mold on the inner wall surface of the cylindrical heating device. A step of vulcanizing the unvulcanized rubber material in the mold by transmitting heat to the mold while holding the mold.The mold is removed from the cylindrical heating device, and the molded rubber product is molded and vulcanized from the cavity. A method of pressure vulcanization of rubber, characterized by comprising a step of taking out the rubber. 2. A column-shaped mold having a tunnel-shaped cavity and divided into two or more parts parallel to the axis, and a tunnel-shaped vulcanization chamber into which the mold can be inserted in a closed state, and the inner wall surface of the mold a cylindrical heating device for holding the vulcanization chamber; a pressure device installed at or near the open end of the vulcanization chamber for pressing each divided mold from the outer periphery of the mold to close the mold; Transport it to the vulcanization chamber of the heating device,
A heating vulcanizing device for rubber, comprising a mold loading/unloading device.