JP4119132B2 - Mold for raw tube vulcanization for tires - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a mold for vulcanizing a raw tube for a tire that can efficiently vulcanize and mold a plurality of tire tubes at a time.
[0002]
[Background Art and Problems to be Solved by the Invention]
In recent years, the use of tubeless tires for automobiles has progressed, and tires with tubes are being used only for motorcycles and parts of large trucks. Therefore, the vulcanizing press for tire tubes is in an excessive state.
[0003]
However, among motorcycles, for example, small and lightweight motorcycles such as mopeds often use tires with tubes. Therefore, improvement in productivity of tubes used in this type of tire and cost reduction are strongly desired.
[0004]
A tire tube vulcanizing apparatus has a structure in which a pair of upper and lower split molds are attached to a vulcanizing press machine via a platen (hot plate). One cavity is provided. Therefore, since it is necessary to open and close the mold every time one tube is vulcanized, the productivity is poor, and furthermore, the release of heat energy accompanying the opening and closing of the mold and the driving energy of the vulcanizing press (for example, electric energy) ) Is increasing, leading to an increase in energy costs.
[0005]
In order to increase the production volume, it is necessary to add a vulcanizing press machine. This hinders effective use of the factory space and requires a mold for each additional vulcanizing press machine. There is also a problem that the cost of mold production increases.
[0006]
Therefore, the present invention forms a plurality of cavities for tube forming in one vulcanization mold, and applies an internal pressure to each raw tube attached to the plurality of cavities in the lower mold of the vulcanization mold. Based on the provision of the internal pressure supply means to supply, it is possible to efficiently vulcanize and mold a plurality of tire tubes at a time, improve the productivity of tire tubes while keeping energy costs low, The purpose is to provide a mold for vulcanizing raw tubes for tires that can reduce the number of expansions, effectively use factory space, and reduce the cost of mold production.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 of the present application is for vulcanizing a raw tube for a tire which vulcanizes a raw tube for a tire provided with an air valve on a donut-shaped tube body made of raw rubber. Mold,
An upper mold having a plurality of cavities for forming a tube formed by contacting the split surface, the lower mold having an upper mold that is movable toward and away from the slit, and a lower mold;
The lower mold is provided with an internal pressure supply means for supplying an internal pressure to each raw tube mounted in the plurality of cavities.
[0008]
In the first aspect of the invention, the internal pressure supply means is provided in advance in each raw tube at a distal end extending from the base hole extending from one internal pressure air supply port provided in the lower mold and extending from the base hole. Consisting of a branch path having a flexible hose with an adapter to be plugged into and connected to the air valve;
In the center position of the cavity, through the upper and lower molds, extending up and down, the working space to connect the adapter by inserting it into the air valve,
In addition, a valve insertion groove through which the air valve passes is formed in the wall surface of the notch portion in which the side wall of the void is cut out in a U-shape, and the tip of the air valve protrudes into the notch portion . .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a raw tube vulcanization mold (hereinafter referred to as a vulcanization mold) for a tire according to the present invention, FIG. 2 is a plan view showing a split surface of a lower mold, and FIG. It is a bottom view which shows the split surface of a type | mold.
[0010]
1 to 3, the vulcanizing mold 1 is provided with recesses 2U and 2L in the split surfaces SU and SL, which form a plurality of cavities 2 for tube forming by the split surfaces SU and SL coming into contact with each other. The upper mold 3U and the lower mold 3L, which are movable toward and away from each other, are provided, and a plurality of raw tubes W mounted in the cavities 2 are simultaneously vulcanized.
[0011]
Here, the raw tube W is provided with an air valve W2 protruding radially inward in a donut-shaped tube body W1 made of raw rubber, as schematically shown in FIG. For example, the raw tube W is obtained by cutting a long tube material extruded as a thin tubular body having a circular cross section into a predetermined length, attaching an air valve W2 at a predetermined position, and then joining both ends thereof. Is formed. The tube body W1 is usually formed with a rubber thickness of 0.8 to 1.8 mm.
[0012]
The upper mold 3U and the lower mold 3L are attached to a press machine (not shown) via upper and lower platen plates (hot plates) 4U and 4L so as to be movable up and down. A press machine having a well-known configuration can be used, and a press machine for forming a large-diameter tube that tends to be surplus in the tire industry can be suitably employed.
[0013]
Next, as shown in FIGS. 1 and 3, the upper mold 3 </ b> U has one concave portion 2 </ b> U for forming a plurality of cavities 2 formed in an annular shape on the split surface SU. The recess 2U is an annular groove having a semicircular cross section. In this example, in order to form three cavities 2, three recesses 2U are formed around the mold center C with an equiangular pitch. The case is illustrated.
[0014]
As shown in FIGS. 1 and 2, the lower mold 3L has the other concave portion 2L for forming the cavity 2 on the split surface SL, and the upper and lower concave portions 2U and 2L are combined to form a circle. A cavity 2 having a shape cross section is formed. A cavity 5 extending vertically through the upper and lower molds 3U, 3L is provided at the radially inner side of each cavity 2, in this example, at the radial center position of the cavity 2. The void 5 is formed as a working chamber for connecting the internal pressure supply means 7 to the air valve W2 of the raw tube W mounted in the cavity 2, but in addition, the heat capacity of the entire mold is reduced. It also has functions such as shortening the rise time of the vulcanization temperature and reducing the weight of the mold.
[0015]
The recess 2L includes a recess main body 10 formed of an annular groove having a semicircular cross section, and a valve insertion groove having a U-shaped cross section extending in a small length radially inward from the recess main body 10 and through which the air valve W2 passes. In this example, the valve insertion groove 11 opens at the wall surface of the notch 5A adjacent to the recess 2L by notching the side wall of the space 5 in a U-shape. Accordingly, the air valve W2 passing through the valve insertion groove 11 can project its tip into the notch 5A.
[0016]
In the vulcanization mold 1 of this embodiment, the lower mold 3L is provided with an internal pressure supply means 7 for supplying an internal pressure to each raw tube W mounted in the plurality of cavities 2.
[0017]
Here, the raw tube W is set in the recess 2L of the lower mold 3L in the mold open state, and the internal pressure supply means 7 is connected to the air valve W2. Thereafter, the upper mold 3U is lowered and the mold is closed, and an internal pressure is supplied to each raw tube W to perform vulcanization molding. However, since the raw tube W has a small rubber thickness, it is necessary to supply the internal pressure in the mold closed state within a short time (about 10 seconds or less) after being set in the lower mold 3L. Beyond this, the lower half of the set raw tube W is softened by heating with the lower mold 3L, so that when the internal pressure is supplied, the rubber extension of the lower half increases compared to the upper half, and vulcanization occurs. Product quality will be degraded, such as making the rubber thickness of the tube later uneven.
[0018]
Therefore, it is important to connect the internal pressure supply means 7 to each of the plurality of raw tubes W within a short time (about 10 seconds or less).
[0019]
For this purpose, the internal pressure supply means 7 is inserted into the air valve W2 by branching from the base hole 13 extending from one internal pressure air supply port 12 provided in the lower mold 3L and extending from the base hole 13 to the air valve W2. A branch path 16 having a flexible hose 15 having an adapter 14 to be connected is formed.
[0020]
Specifically, in this example, as shown in FIGS. 1 and 4, a branch is provided on the lower surface of the lower mold 3 </ b> L from the internal pressure air supply port 12 opened on the side surface of the lower mold 3 </ b> L at the mold center C. A main groove 21 for piping extending to the fitting housing chamber 20 and a branching groove 22 for piping branching from the branch fitting housing chamber 20 to each space 5 are recessed. The branch fitting housing chamber 20 is a through-hole penetrating the lower mold 3L up and down, and a branch fitting 23 is housed therein as conceptually shown in FIG. Note that the branch fitting housing chamber 20 can be formed at a free position away from the mold center C.
[0021]
The base hole 13 is a pipe 24 that passes through the main groove 21, and conducts between the internal pressure air supply port 12 and the branch fitting 23. Note that an internal pressure air supply source J such as steam or high-pressure air is connected to the pipe 24 through a joint provided in the internal pressure air supply port 12.
[0022]
Further, in this example, the branch path 16 is branched from the pipe 24 through the branch fitting 23 and is connected to the pipe 25 passing through the branch groove 22 and connected to the pipe 25 via a fitting. And a flexible hose 15 extending in the direction.
[0023]
The flexible hose 15 is a flexible hose body that can be freely bent. At the tip of the flexible hose 15, as shown in FIG. 5, the flexible hose 15 is connected to the air valve W2 by one-touch operation. Adapter 14 is provided. In this example, the adapter 14 has a tapered cone-shaped nozzle portion 14A inserted into the valve hole.
[0024]
Thus, since the internal pressure supply means 7 uses the flexible hose 15 and is provided with the adapter 14 that can be connected to the air valve W2 with one touch at the tip thereof, each of the plurality of raw tubes W is efficiently and quickly provided. The internal pressure supply means 7 can be connected to the main body, and the deterioration in quality which becomes a problem when vulcanizing and molding a plurality of raw tubes W at a time can be suppressed.
[0025]
Further, since a plurality of raw tubes W can be vulcanized and formed at a time, the productivity of the tubes can be improved while keeping the energy cost low. In addition, it is possible to suppress the increase in the number of vulcanizing press machines when increasing the production of tubes, and it is possible to achieve effective utilization of factory space and reduction of mold production costs.
[0026]
In this example, the branch path 16 is constituted by the pipe 25 and the flexible hose 15, but the branch path 16 may be configured only by the flexible hose 15 by directly connecting the flexible hose 15 to the branch fitting 23. it can.
[0027]
FIG. 8 schematically shows another embodiment of a vulcanizing mold 1 suitable for vulcanizing a plurality of raw tubes having different diameters. FIG. 8 is a plan view showing the lower mold 3L as a representative, and a small-diameter raw tube is vulcanized on the split surface SL inside the recess 2L2 for vulcanizing the large-diameter raw tube. For example, the case where the concave portion 2L1 is formed concentrically is illustrated.
[0028]
Even in such a case, the internal pressure supply means 7 is preferably formed by a base hole 13 extending from the internal pressure air supply port 12 and a branch path 16 having a flexible hose 15 extending from the base hole 13.
[0029]
As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.
[0030]
【The invention's effect】
As described above, the present invention provides a raw tube in which a plurality of cavities for tube forming are formed in one vulcanizing mold, and the lower mold of the vulcanizing mold is mounted in the plurality of cavities. Since the internal pressure supply means for supplying the internal pressure is provided, a plurality of tire tubes can be efficiently vulcanized and molded at a time, and the productivity of the tire tubes can be improved while keeping the energy cost low. It can also reduce the number of vulcanizing presses, effectively use factory space and reduce the cost of mold production.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a vulcanization mold according to the present invention.
FIG. 2 is a plan view showing a lower mold together with its split surface.
FIG. 3 is a bottom view showing an upper mold together with its split surface.
FIG. 4 is a cross-sectional view illustrating a cavity.
FIG. 5 is a cross-sectional view illustrating a flexible hose together with an adapter.
FIG. 6 is a perspective view illustrating a raw tube.
FIG. 7 is a diagram substantially holding the internal pressure supply means.
FIG. 8 is a plan view showing another embodiment of a vulcanizing mold.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vulcanization mold 2 Cavity 2U, 2L Recess 3U Upper mold 3L Lower mold 7 Internal pressure supply means 12 Internal pressure air supply port 13 Base hole 14 Adapter 15 Flexible hose 16 Branching path SU, SL Split surface W Raw tube W1 Tube Body W2 Air valve

Claims (1)

A vulcanization mold for a raw tube for a tire for vulcanizing a raw tube for a tire provided with an air valve on a donut-shaped tube body made of raw rubber to form a tube,
An upper mold having a plurality of cavities for forming a tube formed by contacting the split surface, the lower mold having an upper mold that is movable toward and away from the slit, and a lower mold;
The lower mold, with Keru set the pressure supply means for supplying pressure to the raw tube mounted on the plurality of cavities,
This internal pressure supply means is connected to a base hole extending from one internal pressure air supply port provided in the lower mold, and from the base hole to the air valve provided in advance in each raw tube at the tip. It consists of a branch path with a flexible hose with an adapter,
In the center position of the cavity, through the upper and lower molds, extending up and down, the working space to connect the adapter by inserting it into the air valve,
In addition, a valve insertion groove through which the air valve passes is formed on the wall surface of the notch portion in which the side wall of the void is notched in a U-shape, and the tip of the air valve protrudes into the notch portion. Mold for raw tube vulcanization for tires.

Images