JPH0151325B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tire molding mold and a method for manufacturing the same, and particularly to a mold body having an inner peripheral surface corresponding to at least the outer shape including the tread of the tire to be molded;
In the tire molding mold and the manufacturing method thereof, the mold body has a joint surface that contacts the inner circumferential surface and a rib portion that has a concave portion forming surface portion for forming a concave portion of the tire to be molded. For example, if it is possible to update the design without updating the mold body by manufacturing the bone portion and the bone portion separately and configuring the bone portion to be attached to the inner circumferential surface of the mold body. and the concave portion of the tire makes a right angle or an acute angle from the tread surface of the tire so that the hem portion constituting the concave forming surface portion of the bone portion and the joint surface of the bone portion are connected at an acute angle including a right angle. The present invention relates to a tire molding mold which is partitioned by ridge lines and further has a ventilation gap formed at the joint portion between the bone portion and the inner circumferential surface of the mold body, and a method for manufacturing the same.

In general, tire molding molds have a design on the inner surface of the mold corresponding to the outer shape of the tire to be molded, as shown in FIG. A corresponding bone portion 2 is formed and configured, and the tread portion 1
It is well known that the design and dimensional accuracy formed by the bone portion 2 affect the tire's characteristics such as handling stability, running performance, ground contact performance, and noise prevention.

Conventionally, the above-mentioned tire molding molds have been produced by manufacturing methods such as plaster molding, sand casting, ceramic casting, metal mold casting, other precision casting, engraving, and electrical discharge machining. It is manufactured by integrally molding the tread portion 1 and the bone portion 2, or by welding the bone portion 2 to the inner circumferential surface of the tread portion 1 in advance. Therefore, every time the design of the tire is updated in order to improve the various characteristics of the tire described above, it is necessary to renew the entire mold. Ventilation means such as gas vent holes were also fabricated separately. Furthermore, it has been impossible to manufacture a tire mold with high precision such as coaxiality and roundness within 0.1 mm. Or, in order to ensure that the recesses on the tread of a molded tire are separated by ridge lines at right angles or acute angles from the tread of the tire, a huge number of man-hours are required to finish the tire. Ta. Therefore, there are problems such as not only an increase in the cost of manufacturing the mold, but also a significantly longer manufacturing period.

It has also been proposed to divide the bone portion 2 into individual pieces and fit the pieces into grooves on the tread portion 1 (Japanese Patent Application No. 51-65431). However, in this case, there is a problem in that rubber gets into the gap between the groove and the piece during tire molding, and undesirable protrusions (burrs) are likely to occur on the tire tread.

The present invention aims to solve the above-mentioned problems, and includes a mold body having an inner peripheral surface corresponding to at least the outer shape including the tread of the tire to be molded, and a bone portion for molding the concave portion of the tire. are manufactured separately, so to speak, and the bone portion is attached to the perfectly circular inner circumferential surface of the mold body in a so-called pasting manner, and the bone portion and the inner circumferential surface of the mold body are By forming the ventilation gap using the joining gap, the accuracy of coaxiality, roundness, etc. is extremely high, and the manufacturing cost is reduced and the manufacturing period is shortened. It is an object of the present invention to provide a tire molding mold that prevents the formation of undesired burrs on a molded tire and provides good ventilation such as degassing, and a method for manufacturing the same. This will be explained below with reference to the drawings.

FIG. 2 is an explanatory diagram for explaining the present invention, in which FIG. 2A is a sectional view of one embodiment of the present invention, and FIG. 2B is a developed plane of the mold surface in the embodiment illustrated in FIG. 2A. 3 is an explanatory diagram of one embodiment of the bone attachment means of the present invention, FIG. 4 is an explanatory diagram of another embodiment of the bone attachment means of the present invention, and FIG. 5 is an explanatory diagram of another embodiment of the bone attachment means of the present invention. FIG. 5A is a cross-sectional view, and FIG. 5B is a developed plan view. Reference numerals 2-1 to 2-4 in the figure are bone parts corresponding to the bone part 2 shown in FIG. What constitutes the illustrated tread portion 1, 5-1 to 5-4 are the joint surfaces of the bone portions 2-1 to 2-4, and are inner peripheral surfaces at the installation positions of the bone portions 2-1 to 2-4. Those formed corresponding to 4, 6 is a bone part attachment vault, 7
8- is a gas venting slit constituting a ventilation gap;
1 to 8-3 are protrusions, and 9-1 to 9-3 are fitting grooves, which are formed on the inner circumferential surface 4 of the mold body 1 so that the bone protrusions 8 are fitted as necessary. 10 is a vault through hole, 11-
Reference numerals 1 to 11-3 represent concave grooves formed on the bone side as necessary. In addition, in FIG. 2A, FIG. 2B, FIG. 3, FIG. 4, FIG. 5A, FIG. 2-4 are indicated, but the mountain-shaped surfaces where the leader lines 2-1 to 2-4 are located are referred to as recess forming surface portions in this specification. There is.

The tire molding mold of the present invention will be explained with reference to FIGS. 2A and 2B. Note that FIG. 2A shows a sectional view taken along arrow A-A' in FIG. 2B. As shown in FIGS. 2A and 2B, the tire molding mold of the present invention has a mold body 3 and a bone portion (FIGS. 2A and 2B).
The rib portions 2-1 to 2-4 are provided with attachment means (a third
For example, a protrusion provided on the bone portion is fitted into a fitting groove on the inner circumferential surface 4 and is removably attached. The material of the mold body 3 is mainly iron or aluminum, and the inner peripheral surface 4 of the mold body 3 is machined to correspond to the curved surface including the tread of the tire to be molded. . The bone parts 2-1 to 2-4 are mainly made of iron or aluminum, and are formed into concave portions of the tire to be molded by precision casting methods such as lost wax method, ceramic mold method, and plaster mold method. The joint surface 5-1 to 5-4 is manufactured to have a shape corresponding to the shape and to have joint surfaces 5-1 to 5-4 corresponding to the inner circumferential surface 4 at the installation position of the bone parts 2-1 to 2-4. At this time, the joint surface is connected to the concave-forming surface portion having a shape corresponding to the concave portion of the tire, but when making the connection, a right angle or an acute angle is made to the hem of the concave-forming surface portion. It is made to be connected with each other.
As a result, on the tread of the molded tire, the recesses on the tread are defined by ridge lines at right angles or acute angles from the tread of the tire, making the tread of the molded tire look beautiful. become. In addition, as illustrated in FIG. 6, when an inner circumferential surface corresponding to the outer shape including the tire tread surface is freely formed together with the above-mentioned concave-forming surface, the inner circumferential surface and the above-mentioned concave-forming surface are formed. A so-called radius occurs at the connecting portion with the hem, which spoils the aesthetic appearance of the tire tread. In FIG. 6, 2 represents a bone portion, 4 represents an inner circumferential surface, and 12 represents a recess forming surface portion.

Next, the bone portions 2-1 to 2 in the present invention
An embodiment of the attachment means of -4 is shown in Figs. 3 and 4.
Explanation will be made in conjunction with the figure. In addition, Figures 3 and 4
The illustrated embodiments are all shown in FIG.
A cross-sectional view at B' is shown.

In the embodiment shown in FIG. 3, the bone portion 2-1 is
It is arranged at a predetermined position on the inner circumferential surface 4 of the body and fixed by a bone attachment vault 6.
The embodiment shown in FIG. 4 is similar to the embodiment shown in FIG. 3 in that the bone part 2-1 is fixed by the bone part attachment vault 6, but
-1 is provided with a protrusion 8, and a fitting groove 9 into which the protrusion 8 is fitted is also provided on the inner circumferential surface 4 of the mold body 3. Therefore, the embodiment illustrated in FIG.
Since the bone portion 2-1 is fixed after the protrusion 8 is fitted into the fitting groove 9, the bone portion 2-1 can be easily positioned. In addition, if the protrusion 8 is not provided due to the shape of the bone, the joint 5-1 may extend over the entire inner peripheral surface 4 of the mold body 3 (around the entire circumference). ) may be in contact with each other. In addition, the above third
The illustrated embodiment in FIG. 4 and FIG. -1 may be fixed. It goes without saying that the bone portion 2-1 is also removable in the attachment means using the taper pin.

Next, the degassing mode in the tire molding mold of the present invention will be explained. In manufacturing the bone part (for example, the bone part 2-1 shown in FIGS. 3 and 4) in the present invention, at least a part of the joint surface 5-
The surface roughness of the protrusions 1 and 8 is about 20 to 80 microns and is finished by polishing, shot-plasting, knurling, etc. If the projection 8 cannot be formed due to the shape of the bone 2, a groove 11 may be formed along the center of the joint surface 5 of the bone 2, as in the embodiment shown in FIGS. 5A and 5B. You can also do it. the result,
A ventilation gap is formed at the joint between the bone part 2-1 and the mold body 3, and gas generated during tire molding is transmitted through the ventilation gap, the fitting groove 9 or the groove 11, and the bone part attachment vault 6. It will be expelled to the outside through the through hole 10. In addition, as the ventilation gap, as shown in FIG. 3, the joint surface 5-1
A gas venting slit 7 may be specially provided to reach the through hole 10. Furthermore, a gas vent hole (not shown) is provided that penetrates the mold body 3 and reaches the joint surface 5-1, so that the gas vent hole and the joint surface 5-1 (or the gas vent slit 7) A gas venting passage may be formed. In this case, the gas generated between the bone parts may pass through the joint surface of one bone part, reach between the adjacent bone parts, and be discharged through an appropriate gas vent hole.

The tire molding die and the manufacturing method thereof of the present invention have been described above, but the bone parts 2-1 to 2-4 in the embodiments shown in FIGS. 2 to 4 are as follows:
At least a large portion of the recess-forming surface portion is previously subjected to finishing processing. Alternatively, the bone parts 2-1 to 2-4 may be manufactured by dividing them into a plurality of pieces (for example, as shown in FIG. 2B).

As explained above, according to the present invention, since the bone part is installed in a removable manner, for example, when updating a tire design, it is possible to replace only the bone part while leaving the mold body as it is. By making this possible, it is possible to significantly reduce the manufacturing cost of the mold and shorten the manufacturing period. In addition, the existence of gas vent holes almost eliminates the occurrence of undesired burrs on the molded tire, which saves the effort of removing burrs and leaves no traces of burr removal on the tire surface. Therefore, it is possible to improve the image of the tire product appearance.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a general example of a tire molding mold, FIGS. 2A and B are explanatory diagrams for explaining the tire molding mold of the present invention, and FIGS. 3 and 4 are diagrams of the present invention. FIGS. 5A and 5B are explanatory views of each embodiment regarding attachment of bone parts in FIG.
The figure shows an example of a bone portion having a recess-forming surface portion and an inner circumferential surface. In the figure, numerals 2-1 to 2-4 are bone parts, 3 is a mold body, 4 is an inner circumferential surface, 5-1 to 5-4 are joint surfaces, 6 is a bone part attachment vault, and 7 is a ventilation gap. 8 is a protrusion, 9 is a fitting groove, 10 is a vault through hole, and 11 is a concave groove.

Claims (1)

[Scope of Claims] 1. A mold for molding a tire, comprising: a mold body having an inner circumferential surface corresponding to at least the outer shape of the tire to be molded, including the tread; and a joint surface that abuts the inner circumferential surface; a bone part having a concave part forming surface part forming a concave part of the tire to be molded; The mold body is connected at an acute angle, including a right angle, to the joint surface of the mold body, and at least a part of the joint surface is joined to and supported by the inner circumferential surface of the mold body with a ventilation gap formed therein. A mold for molding tires. 2. A tire molding mold having a mold body having an inner circumferential surface corresponding to at least the outer shape including the tread of the tire to be molded, and a rib portion having a concave part forming surface part forming a concave part of the tire to be molded. In the mold manufacturing method, the inner circumferential surface of the mold body is processed to correspond to at least the outer shape of the tire to be molded, including the tread, and the recess is formed to have a shape corresponding to the recess of the tire to be molded. A joint surface that has a processed surface and corresponds to the inner circumferential surface at a predetermined position of the mold body, and that is connected at an acute angle including a right angle to the bottom portion constituting the recess forming surface. A bone part processed to have a shape is manufactured, and the joint surface of the bone part is joined to the inner peripheral surface of the mold body at a predetermined position, and at least a part of the joint surface is connected to the inner peripheral surface of the mold body. 1. A method for manufacturing a tire molding die, characterized in that the mold is manufactured so as to form a ventilation gap between the mold and the surface.