JPH03153317A - Vulcanizing method and its device for rubber hose - Google Patents

Abstract

PURPOSE:To enable vulcanization with normal-pressure hot air without generating bubbles in a rubber layer or a reinforcement layer, by a method wherein vulcanization by the hot air of normal pressure is divided into at least the first half and the latter half heating zones and heating is performed at a low temperature in the first half and at a high temperature in the latter half. CONSTITUTION:A vulcanizing furnace 1 is formed into sealable structure and hot air of the normal pressure is circulated by providing an electric heater on the inside. Heating devices 10 obtained by combining a heater and circulation fan are constituted so that the heating devices 10 are provided respectively on a heating zone of the upper row and a heating zone of the lower row and they are made controllable individually by providing a temperature sensor. The heating zone is divided into the first half and latter half, a lower row furnace 11 is made into the first half heating zone, an upper row furnace 12 is made into the latter half heating zone and a temperature of the first half heating zone is set up higher than that of the latter half. Unvulcanized rubber hose 13 fitted to a mandrel 5 is heated at first by hot air whose temperature is lower than the vulcanizing temperature during transfer within the vulcanizing furnace 1, a rubber layer or a reinforcing fiber layer is free from generation of bubbles and then heated by the hot air having the vulcanizing temperature. At temperature of the above-mentioned rubber layer is raised by drawing a temperature raising curve almost coincident with a rubber vulcanizing curve and vulcanization can be performed in a short time.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method and apparatus for vulcanizing a rubber hose.

(Prior art) Conventionally, unvulcanized rubber hoses are often vulcanized by placing them in a vulcanizing can and introducing pressurized steam, but such methods are batch-type and have poor workability. It has the drawback that it is not very good, and it is expensive when producing small lots. Continuous vulcanization using hot air at normal pressure has also been proposed, but it has been difficult to employ such a method, especially in the case of rubber hoses having a reinforcing fiber layer.

In other words, in the case of the above hose, the temperature of the hot air at normal pressure is
When the required vulcanization temperature is set, vulcanization begins from the surface side, and the air contained in the reinforcing fiber layer and various substances contained in the rubber layer gasify into bubbles, causing a foaming phenomenon. The product will be defective. It is also conceivable to treat the hot air at a temperature lower than the gasification temperature over a long period of time, but such a method would increase the size of the apparatus and is not practical.

(Problems to be Solved by the Invention) In view of the above-mentioned circumstances, an object of the present invention is to make a natural rubber, synthetic rubber, or other rubber hose having reinforcement M under normal pressure without generating bubbles in the rubber layer or reinforcing layer. An object of the present invention is to provide a vulcanization method and apparatus that enable vulcanization using hot air.

(Means for Solving the Problems) According to the present invention, the above object is achieved by inserting an unvulcanized rubber hose into a T-mandrel and transferring it in hot air at normal pressure, and changing the heating zone through which the mandrel passes to at least the front stage and the rear stage. Separate,
This can be achieved by a vulcanization method in which the latter heating zone is vulcanized at a higher temperature than the preceding heating zone.

The temperature difference between the heating zones is set to an optimal condition depending on each type of rubber, but good results are obtained when the temperature is set at 30° C. or higher.

(Function) While the unvulcanized rubber hose attached to the mandrel is being transported through the vulcanization furnace, it is heated by hot air at a temperature lower than the vulcanization temperature, and air bubbles from the rubber layer and reinforcing fiber layer are removed. There is no generation, and it is then heated by hot air at the vulcanization temperature. The temperature of the rubber layer increases along a temperature rise curve that substantially matches the vulcanization curve of the rubber, and can be vulcanized in a short time.

(Example) This will be explained below along with examples.

FIG. 1 shows a perspective view of the device, and FIG. 2 shows an explanatory view.

In the figure, a vulcanizing furnace (1) is formed to have a hermetically sealed structure, and is equipped with an electric heater inside to circulate hot air at normal pressure. The inside of the vulcanization furnace (1) is divided into upper and lower heating zones, with a partition wall (2) in the middle, and an upper furnace heat-insulating shutter (3) that moves up and down, and a shutter that opens and closes on the left and right. A lower furnace heat shielding shutter (4) is provided. These shunters are actuated by hydraulic cylinders, pneumatic cylinders, motors, or other suitable means, and are opened when the mandrel (5) passes through the opening, and are normally moved to a closed position to seal the inside of the furnace. There is.

The heating means provided in the heating zone is an electric heater (6)
It has a circulation fan (7) that circulates the heat generated from the heater as hot air, and a guide plate (8) and a rectifier plate (9) are fully formed so that the hot air circulates in the direction of the arrow in FIG.

Since the temperature distribution inside the furnace changes depending on the inclination angle of the current plate (9), it is necessary to set it to a desired state.

In the figure, a heating means OQ that combines the above-mentioned heater and a circulation fan is provided at 7 locations each in the upper heating zone and the lower heating zone, and a total of 7 locations are provided in the furnace corresponding to each heating means. Temperature sensors (shown in the diagram) are installed in each section to enable individual control. By providing the plurality of heating means described above, it is possible to create a temperature difference in the hot air generated by each heating means. Can be divided into multiple zones. In the figure, the heating zone is divided into front and rear stages, the lower furnace α1) is the front heating zone, the upper furnace □□□ is the latter heating zone, and the latter is set at a higher temperature than the first stage. By adjusting the heating means mentioned above, it is possible to provide a heating zone with an intermediate temperature, or to heat the heating means near the opening to a higher temperature than the heating means adjacent to the inside so that the heat inside the furnace does not dissipate. It is possible to provide zones and various configurations. Further, an air curtain or a shutter interlocking with the shutters (3) and (4) may be provided between the heating zones (not shown).

The mandrel (5) to which the unvulcanized rubber hose □□□ is attached is.

The rubber hose is bent into various shapes so that it can be vulcanized into a desired shape, and is fixed in multiple rows upright on the side of a mounting base A4 made of angle iron or the like as shown in the figure. L-shaped mounting pieces (towards) are fixed to both ends of the α-piece.

The transport means for holding and transporting the mandrel uses a transport chain belt, but a robot or other suitable transport means may also be used.

The chain belt (2) is provided on both sides of the vulcanizing furnace, and is stretched between the sprocket (Lη) located inside the furnace and the sprocket (Lη) located outside the furnace, and is driven by a motor or other intermittent drive device (not shown). It moves intermittently at an appropriate tact.The running chain is supported by rails or other guiding means so that it does not sag, and the chain is attached to the stay a'a1 between the chains on both sides (Figure 1). A bracket (7) protruding from the side of the link of the belt (to) is fixed with a holder having an insertion groove, into which the mounting piece cL91/r of the mounting base is inserted, It is removably attached with bolts or other fastening means.0 Figure 5 shows a clamp (
b) is shown. The clamp (A) forms a flat frame (C) on the base (2) which is inserted into the insertion groove of the holder (2), and a presser bolt is attached to the tip of the frame (C). (c) Hold the presser foot link ■ with the pivot.

A connecting link (goods) was pivotally attached to the middle part of the presser link (c) (Figs. 6 and 7), and the other end of the connecting link (e) was pivotally attached to the above example frame. It is pivoted to the handle 01) by C33. When the handle 6υ is in the upright position (Fig. '6), the presser bolt (2) at the tip of the presser link (C) tightens the mounting piece a5 and the mounting base Q-
9 is held so that it does not fall off. As shown in the seventh factor, when the handle G1) is overturned, the holding bolt (2) is moved upward, the mounting piece (G) is released, and the mounting base Q4 can be taken out. in this way,
When the clamp (a) is used, the mounting stand αΦ can be attached to and removed from the transfer means very easily and in a short time, resulting in good workability.

The opening of the vulcanization furnace (1) is provided with a work stage (to) for approaching the mandrel that has come out of the vulcanization furnace by the transfer means (Figure 1, Figure R). The stage (to) is provided so that an operator can easily remove a vulcanized rubber hose or insert an unvulcanized rubber hose. During insertion work, silicone oil or other lubricant is applied or dripped onto the mandrel, and a receiving groove for this purpose is formed at the top and an inclined plate is formed at the front. The work stage (to) has a fixed part (to) and a movable part Gη, and the movable part C3? )
A bearing (to) is provided below, and the bearing (to) is connected to rail C3.
1 so that it slides on top. A hydraulic cylinder 0Q is provided in the fixed part (to), and the hydraulic cylinder GiI
The rod 1''@1) is connected to the movable part.Then, when the movable part or the mandrel (5) moves, the hydraulic cylinder (40) separates it from the vulcanizing furnace (1). When the mandrel drive is stopped, the vulcanization furnace (
It is moving forward and backward so that it approaches 1). By providing the work stage so that it can move forward and backward in this manner, it is easy for the operator to work, and the movement of the mandrel is not hindered.In addition, the rubber hose can also be attached and detached by a robot.

The vulcanization temperature of the heating zone is set depending on the type of rubber material to be vulcanized, the structure of the product, etc.
In an embodiment using a rubber material such as, the heating zone of the lower furnace aυ is set to about /30°C, the heating zone of the upper furnace side is set to about /70°C, and the temperature difference between the two heating zones is f30°C or more, preferably po℃
After making the above adjustments, a rubber hose with a reinforcing fiber layer provided between the inner rubber layer and the outer rubber layer was inserted into the mandrel and circulated through the vulcanization furnace using a transfer means, resulting in foaming from the rubber layer and the reinforcing layer. Vulcanization was completed in about IA 0 minutes without any problems.

When the temperature difference was less than 30°C, foaming occurred.

In the above-mentioned products, the heating zone of the lower furnace αη is approximately /
It was confirmed that vulcanization could be achieved without foaming if the heating zone on the upper furnace side was set at about 0°C±10°C.

The above transfer means is a mounting base α on which many mandrels are attached.
Since the mandrels 4 are supported and circulated, mounts with various mandrel shapes can be attached to the transfer means and vulcanization can be performed at the same time. Providing a post-process following the above-mentioned work stage simplifies the flow and shortens processing lead time.

In the figure, the vulcanization furnace is divided into two stages, upper and lower, and the mandrel enters from the lower stage of the opening, passes through the upper stage, and returns to the opening, but it can be divided into three or more stages. The vulcanizing furnace can be circulated separately, or the mandrel can be configured to have openings at both ends so that it enters at one end and exits at the other end, or the mandrel can be circulated horizontally, and at least the heating sections of the front and rear stages can be circulated in between. band? (Effects of the Invention) The present invention is configured as described above, and vulcanization using unpressurized hot air is divided into at least a first stage and a second stage heating zone, and the first half is low temperature, The second half of the vulcanization is carried out at a high temperature, making the total vulcanization time longer than in the case of steam vulcanization and the temperature of the rubber layer. Since the temperature can be raised with a temperature rise curve that almost matches the vulcanization curve of the rubber, there is no risk of foaming even in rubber hoses that have a reinforcing fiber layer between the inner and outer rubber layers, and the inside of the hose The difference in vulcanization density on the surface can be reduced, resulting in a product with excellent physical properties, adhesive strength, and breaking strength. In addition, even in high-mix, low-volume production, the mandrel circulating in the vulcanization furnace can be replaced, so production can be done at the same cost as in large-lot production.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a perspective view, Fig. 2 is an explanatory drawing, the following is an enlarged view, Fig. 3 is a longitudinal sectional view, and Fig. 3 is a perspective view of a portion of the holder of the transfer means. , FIG. 5 is a perspective view of the clamp, FIG. 6 is a side view of the clamp in a tightened state, FIG. 7 is a side view of the handle in an inverted state, and FIG. R is a sectional view mainly of the working stage. 1... Vulcanizing furnace, 3... Upper furnace heat shielding shutter 4...
・Lower furnace shield i-shutter 5...Mandrel 6...
Electric heater, 7... Circulation fan 10... Heating means, 11... Lower furnace, 12... Upper furnace 21°゛° holder 22... Clamp 33... Work stage

Claims (1)

[Claims] 1. Insert an unvulcanized rubber hose into a mandrel, transfer the mandrel into hot air at normal pressure, and divide the heating zone through which the mandrel passes during transfer into at least a front stage and a rear stage, A method of vulcanizing a rubber hose, characterized in that vulcanization is performed in a later heating zone at a higher temperature than in a preceding heating zone. 2. The temperature difference between the front heating zone and the rear heating zone is 30℃.
The method of vulcanizing a rubber hose according to claim 1, wherein the method is as follows. 3. It has a vulcanization furnace that circulates hot air, has a transfer means for holding and transferring a mandrel to which an unvulcanized rubber hose is attached in the vulcanization furnace, and has a plurality of heating means each having a heater. A vulcanizing apparatus characterized in that a temperature difference is provided in the hot air generated by the heating means. 4. The vulcanizing apparatus according to claim 3, wherein the heating means located after the transfer is set at a higher temperature than the heating means located before the transfer. 5. The vulcanizing apparatus according to claim 3 or 4, wherein the vulcanizing furnace is divided into upper and lower heating zones, and the transfer means circulates between the upper and lower heating zones. 6. A working stage is provided at the opening of the vulcanizing furnace to approach the mandrel that has come out of the vulcanizing furnace by the transfer means, and when the mandrel is moved through the working stage, it is separated from the vulcanizing furnace and the mandrel is moved away from the vulcanizing furnace. Claim 3 characterized in that it is provided so that it can advance and retreat so as to approach when the movement is stopped.
Or the vulcanization device according to 4. 7. The vulcanizing apparatus according to claim 3, wherein the transfer means for holding the mandrel has a holder, and the mounting base of the mandrel is inserted into the holder and removably fastened with a clamp.