JPH0125685B2 - - Google Patents

Description

Detailed Description of the Invention The present invention involves inserting a green tire into a pair of split molds, forming a sealed space containing the inside of the tire body by closing the split molds, and directly supplying a pressure medium into the space. The present invention relates to a device for vulcanizing a tire.

Conventionally, in tire vulcanization, a prepared green tire is inserted into a pair of upper and lower split molds, and a diaphragm made of a rubber composition called a bladder is provided inside the tire body, and this bladder is inflated during vulcanization. There is a method in which a pressure is generated that acts outward in the radial direction, the mold is firmly pressed against the heated mold surface, and vulcanization is performed after a predetermined period of time has elapsed.

However, heating only from the heated mold side as described above is inefficient because it takes a long time to transfer heat to the green tire.

To eliminate this drawback, a widely used method is to inject hot water or steam into the bladder to heat the tire from the inside, but even with this method, it is difficult to maintain the green tire at an appropriate vulcanization temperature. The presence of a bladder impairs heat transfer efficiency. Furthermore, the bladder deteriorates rapidly with repeated use and must be replaced after a predetermined number of bladders have been processed, which has the disadvantage of complicating operations.

Therefore, in recent years, a green tire is inserted into a split mold, the mold is closed, a sealed space containing the tire body is formed in the mold, and a pressure medium is directly fed into the space. A vulcanization method has been proposed in which a heat source is installed in a space to directly apply pressure and heat from the inside of the tire body to increase heat transfer efficiency and save energy.

In carrying out this vulcanization method, when the split mold is closed, the tire body is completely adhered to the mold surface to prevent pressure medium from leaking from the joints of the parts that make up the mold. In order to achieve this, a device is required that mechanically presses the bead portion of the tire body against the mold surface from the inside.

When the split mold is open, this bead holding device takes a position that does not prevent the tire body from being put in and taken out of the mold, in other words, the diameter of the entire bead is smaller than that of the bead, and when the mold is closed, the device expands to hold the bead. It is necessary to reach the top of the part and press it correctly from the inside under a predetermined pressure.

The present invention has been made in view of the above-mentioned points, and is a tire vulcanizing device that vulcanizes a green tire by directly applying a pressure medium to the tire body, and in which the tire body is moved in and out of the mold. We have developed a device that allows the bead of the tire body to be properly pressed against the mold surface during vulcanization without any interference, and that is linked to the closing movement of the mold, so that it can be done easily and rationally, and that has a simple structure. This is what we are trying to provide.

Embodiments of the present invention will be described below with reference to the drawings.

Reference numerals 1 and 2 designate a pair of upper and lower split molds, both of which have central body parts 1a and 2a and tread molds 1b and 2b connected to their outer peripheries. The mold 2 is connected to the lower mold 1 to an operating mechanism (not shown) so that it can be opened and closed.

Reference numerals 3 and 4 denote a pair of holding members disposed above the main body portion 1a of the lower mold 1 while being supported by the main pair portion 1a. A spring 6 is interposed between the lower holding member 3 and the lower mold to hold the holding members 3 and 4 in a floating state above the lower mold 1 under no pressure. A guide rod 7 protruding from the lower mold 1 is inserted into a guide hole 8 protruding from the main body 1a of the lower mold 1, so that the holding members 3 and 4 are immobilized and are only allowed to move up and down.

Reference numeral 9 denotes a number of actuating bodies mounted on the peripheral edges of the holding members 3 and 4 between the split molds 1 and 2 and the holding members 3 and 4 facing them so as to be movable forward and backward in the radial direction. A contact plate 10 that contacts the inner surface of the bead portion B of the tire body A is attached to the tip of the tire body A via a support rod 11 so as to be movable in the vertical direction.
A spring 12 is interposed between the actuating body 9 and the actuating body 9 to bias the contact plate 10.

The thickness of this plate 10 can be changed by approximately the equivalent thickness of the plate 10 by alternating the lengths of the support rods 11 between adjacent actuating bodies 9 so that the distance between them is different from the operating body 9 under no pressure. A high resistance difference is provided at the position of the contact plate 10.

13 is a block outer circumferential surface 9 protruding from the base end of each operating body.
This is an endless annular pullback coil spring which is connected and wound around a, and by the diameter reduction bias of this spring 13, all the actuating bodies 9 are retreated all at once, and are placed in the diameter reduction position as a whole.

14 is a block inner circumferential surface 9 protruding from the base end of each operating body.
This spring 14 is an extruded coil spring having an endless annular shape attached to the main bodies 1a and 2a of the upper and lower split molds 1 and 2 so as to face the outwardly expanding inclined surface 9c formed in b. Projections 1c and 2c protruding from the inner surface of the main body
The inclined surface 15 of the ring 15 from the inside on the surface.
When the mold is closed, the actuating body 9
The actuating body 9 slides downward on the inclined surface 9c of the block.
is advanced against the retraction coil spring 13.

Note that this extruded coil spring 14 is for moving all the actuating bodies 9 forward at once under the same conditions, and instead of this, it is designed to contact the inclined surface 9c of the actuating body 9 with reduced sliding friction. It is also possible to use an extruded member made of a combination of a series of ring bodies or a roller body.

In the figure, 16 is a heating means disposed between the upper and lower holding members 3 and 4, which consists of a heater 16a and a fan 16b.The heater 16a is connected to an external power source (not shown), and the fan 16b is connected to the lower metal It is connected to a motor 17 disposed at the bottom of the mold via a shaft 18 having a spline joint 18a.

In the above configuration, the operation will be explained next.

As shown in FIG. 2, when the upper mold 2 is open, the holding members 3 and 4 on the lower mold are in positions pushed up by the springs 6. All of the actuating bodies 9 are uniformly retracted by the pull-back coil springs 13, and are in a diameter-reduced position as a whole, which is smaller than the inner diameter of the bead portion of the tire body A. At this time again,
The contact plates 10 are placed next to each other and have heights at their positions so that there is no mutual interference.

In this state, after the green tire A is inserted into the upper and lower split molds 1 and 2 and preparation for vulcanization is completed, the upper mold 2 is lowered to close the tires. During this operation, the extruded coil spring 14 held on the protruding portions 1c and 2c of the upper and lower split molds 1 and 2 hits the block inclined surface 9c of the actuating body 9, and acts as a pressing force against the actuating body 9. This pressing force also moves the entire holding members 3 and 4 downward against the spring 6, while the spring 14 slides on the block inclined surface 9c, and the entire operating body 9 is moved by the pressing force at the time of its movement. advance in unison. In this way, when the extruded coil spring 14 slides down the block inclined surface 9c and reaches the vertical surface 9b, the actuating body 9 stops moving forward, and then the contact plate 10 moves toward the tire body A.
comes into contact with the inner surface of the bead portion, compresses the spring 12, and enters the pressing state, completing the closing of the upper and lower split molds 1 and 2.

In this way, a sealed space C containing the inside of the tire body is formed between the upper and lower split molds 1 and 2. A pressure medium is supplied to this space C through the pressure medium supply port 19, and the heating means 16 The planned vulcanization is carried out under appropriate heating. To take out the molded tire after vulcanization, the upper mold 2 is opened and the backing plate 1 which had been holding the bead part B from inside the tire body A is removed in the reverse order of the above operations.
0 is separated and pulled out from the tire body, allowing the tire to be taken out without difficulty.

As described above, according to the present invention, a pair of holding members are arranged in the space of the pair of upper and lower split molds,
An actuating body that moves forward and backward in the radial direction is mounted on the holding member, and a contact plate under the bias of a spring is attached to the tip of each of the actuating bodies to divide the forward and backward movement of all the actuating bodies. The opening and closing of the molds are performed simultaneously, and the entire bead of the tire body is elastically pressed down by the backing plate, which not only has a simple structure and can be provided at low cost. The operation of each part is rational, and there is no chance of local stress being applied.Also, the bead part is reliably pressed from its inner surface to the mold surface by a large number of contact plates, and the pressure is reduced. It is possible to completely prevent leakage of the medium to the outside, improve productivity, and obtain high quality and homogeneous products.

Furthermore, the height of the contact plates attached to each actuating body is different to prevent mutual interference between adjacent contact plates when the actuator is in the retracted position, so the horizontal length of each contact plate can be made as large as possible. It can be made longer, and when pressing the bead of the tire body during vulcanization, there is almost no gap between adjacent contact plates, which further enhances the leakage prevention effect of pressure medium, and also simplifies pressure medium supply control. There is an effect.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a partial sectional view of the device of the present invention, FIG. 2 is an explanatory diagram of the operation,
FIG. 3 is a front view of the plate, and FIG. 4 is a side view of the same. DESCRIPTION OF SYMBOLS 1...Lower split mold, 2...Upper split mold, 3...Lower holding member, 4...Upper holding member, 5...Joiner, 6...
... Spring, 7 ... Guide rod, 8 ... Guide hole, 9 ... Operating body, 10 ... Back plate, 11 ... Support rod, 12 ... Spring, 13, 14 ... Endless annular coil spring, 15 ...
...This ring, 16...Heating means, 17...Motor, 1
8...Shaft, 19...Pressure medium supply hole.

Claims (1)

[Claims] 1. Tire vulcanization in which a green tire is inserted into a pair of split molds to form a sealed space containing the tire body, and vulcanization is performed by directly applying a pressure medium to the space. In the apparatus, a holding member is disposed inside the split mold so as to be movable in the axial direction thereof, and a large number of actuating bodies are attached to the holding member so as to be movable forward and backward in the radial direction, and each actuating body is movable in the radial direction. At the same time, an endless annular retraction coil spring is wound around the outer surface of the block protruding from the base end of each actuating body, and is also formed on the inner surface of the block. An extrusion member is attached to the inner surface of the split mold so as to face the outward expanding slope, and when the split mold closes and closes, the extrusion member presses the block slope to move all the working bodies forward at the same time.
A tire body sealing device for a tire vulcanizer, characterized in that a bead portion is elastically pressed down by a contact plate. 2. The tire processing method according to claim 1, characterized in that the contact plates attached to the tip of the operating body are provided with alternating height differences between adjacent contact plates in a free state. Tire body sealing device in sulfurization equipment.