JPS6119314A - Mold for tyre with side protector - Google Patents

Abstract

PURPOSE:To enable a squeeze out part to be cut easily at finishing process when a tyre is taken out of a mold after vulcanizing, though the squeeze out is difficult to be cut easily when it is being taken out of the mold by using such a sectional shape that 0.1-3mm. clearance is provided in between the parallel part of a groove and an insert member at the parallel part, and no clearance is substantially provided in between the groove side surface and the insert member at the inclined part. CONSTITUTION:At the annular insert members 5 or 6 embedded in a groove 4, their surfaces are caused to be suitably female shapes to the shape of a tyre side wall, for instance, the left is the shape corresponding to the annular insert member 5, and the right is the shape corresponding to the annular member 6. The part corresponding to the parallel part (a) of the groove 4 is caused to be the part (a') of the insert member parallel to said parallel part (a) at both sides, and 0.1-3mm. clearance (c) is kept therebetween. Simultaneously at the inner part following said parallel part, the inclined part (b') of the insert member corresponding to the inclined part (b) of the groove is provided, but in between both inclined parts (b), (b'), clearance is not substantially provided. Consequently, while embedding and fixing these annular members 5, 6 in the groove 4, when a tyre is under vulcanization, the squeeze out part with necessary thickness corresponding to the clearance (c) is molded in said clearance. But the material flow between both inclined parts (b) and (b') hardly occurs. Even if it occurs, its root part is of the necessary thickness when the tyre is demolded.

Description

[Detailed description of the invention] [Industrial application field]

The present invention is directed to a mold for vulcanization molding a tire having a raised side protector on a part of the tire sidewall, such as a tire for a construction vehicle. LvE Techniques i) Construction tires are used in areas with many sharp rocks, so to prevent damage to the sidewalls of the tires, one or both sides of the tire sidewalls may be partially covered. A raised side protector is installed all around the circumference, and as this side protector naturally becomes thicker, it is inevitable that the temperature will rise and the resistance to separation etc. will decrease, so it is not necessary. is preferred. However, it is unavoidably necessary in the above-mentioned places, and its formation is indispensable. However, since tires for construction military use that require side protectors are large in size, the molds used to vulcanize and mold them must also be large in size, which can cost tens of millions of yen per side. be. However, although there are many types of tires for construction vehicles, the number of tires produced is extremely small, and the tires belong to a typical small number of different types, and the preparation of special molds for such tires is a burden in terms of cost. For this reason, attempts have been made to vulcanize both types of tires, one with a side protector and one without, using a tun mold. A depression is formed, and an annular body is removably fixed in this depression by bolting.For vulcanization molding of tires without normal side protectors, an M-shaped body is fixed, and in the case of tires with side protectors, an annular body is fixed. A method for vulcanization molding by removing the
It was disclosed in Japanese Patent No. 745. However, it has been found that the use of the mold as described above has the following problems in vulcanization molding. That is, when the annular body is bolted and vulcanized - 3rd
As shown in the figure, since the gap (Cγ) between the wall surface of the mold (10J) and the annular body (12) is essentially zero, it is assumed that the rubber flows during vulcanization molding and protrudes into the gap. , the protruding spill is extremely thin and easy to cut when taken out from the mold after vulcanization, and if it remains on the tire sidewall surface, it is too thin and will be cut during the subsequent cutting and finishing process. O

[Problems to be solved by the invention]

Thus, the present invention addresses the above-mentioned problems, and the protrusion is difficult to cut off when removed from the mold after vulcanization, but
However, in the finishing process after taking out, we aimed to make the mold easy to cut, so we focused on the shape of the recess or groove of the mold and the shape of the annular insert that is embedded and fixed in it, and This aims to solve the problem by considering the degree of fit.

[Means to solve the problem]

However, the feature of the present invention that meets the above-mentioned problems is that in a mold for vulcanization molding a good tire, the side protector is raised on at least one sidewall. The area within the range from 1 to 15 is a parallel part parallel to the tire rotation axis, but inside it is a groove with side surfaces that gradually narrow at an angle and become a continuous slope part, and the groove is buried in the part. The shape of the annular insert to be fixed is such that the surface has a female shape with respect to the shape of the side of the tire, and there is a gap of 1 to 3 gates between the parallel part of the groove and the parallel part of the groove. However, the sloped portion has a cross-sectional shape with substantially no gap between it and the side surface of the groove. Here, it is important to actively create a gap of 0.1 to 3 mm between the parallel part of the front groove and the corresponding annular insert, so that when the tire is removed from the mold after vulcanization molding. Excessive parts are difficult to cut, but are easy to cut in the finishing process after removing the paper.

This is an essential condition for forming [spiu]. If the amount is less than this, the protrusion will become thinner and it will be easier to cut when taking it out from the mold, and if it remains uncut, the cutting mr in the finishing process will be required. It becomes difficult. On the other hand, after the third season, the tongue suffers from the following problems. f
For f1J, the shape of the protrusion is usually made by bending a rectangular halftone plate along the longitudinal direction, cutting out one end of the ridge line created by the bending, and using a 71-core knife with a Z-V shaped blade. The opening of the blade is applied in the circumferential direction of the tire, sandwiching the protrusion, and the blade is propelled forward to cut it.In order to cut even a thin protrusion, the opening of the blade is made small and the blade is sharpened. It is. Therefore, if there is more than 3cm of protrusion, it will fit into the above opening. Also, the blade becomes unable to cut prematurely. Therefore, the above-mentioned gap range is valid. Note that the sloped portion inside the groove is for making it easier to remove the tire from the mold. In addition, the surface shape of the annular insert is female-shaped relative to the sidewall shape of the tire to be vulcanized, but this is due to the vulcanization molding of a tire without a side protector, the shape,
This is to accommodate the vulcanization molding of tires with side protectors of various sizes, and therefore, the annular insert is not limited to one type, but includes those of various shapes.

[effect] When vulcanizing and molding a tire using the above-mentioned mold by force and combing, if the tire does not have a side protector, insert an annular insert with a corresponding surface shape into the groove on the side of the mold. Although not shown, it is fixed by bolts or the like and vulcanization molding is performed by a known method. On the other hand, in the production of tires with side protectors, an annular insert with a surface shape corresponding to the shape and size of the side protector is fixed with bolts, etc., as described above, or an annular insert is fixed in a groove on the side of the mold. Vulcanization and molding are carried out according to known techniques without any embedding and fixing in the mold. In the above case, when an annular insert is used, a portion of the rubber that makes up the tire flows into the gap formed between the groove, the ring, and each parallel part of the insert, causing the rubber to protrude to an appropriate thickness. create. Thereafter, when the tire is taken out from the mold, it does not cause any breakage, and is easily cut off in the subsequent finishing process, so that the aesthetic appearance of the tire is not impaired in any way. 【Example】

Hereinafter, embodiments of the present invention will be described with further reference to the accompanying drawings. FIG. 1 is an enlarged view of the main parts of the mold of the invention X, and FIG. 2 is an explanatory cross-sectional view showing the state of use of the mold of the invention. In each of these figures, (1) is the mold, 12 is the lower mold, (3
] is an upper mold, which usually extends in an annular shape, and a groove (4) is provided in a part of the side portion of the lower mold (2) over the entire circumference. Also%+51. f81 is an M-shaped insert embedded in the groove (41) shown in each cross section, -+51 is an annular insert for a general tire type I without a side protector, and (6) is a side protector when an annular insert is not used. Tires with chikukoo
Stylishly different shaped, large side protectors (fm
L An annular insert for molding a tire - These annular inserts are embedded and fixed in the groove (4) by appropriate means such as bolts or the like that can be easily removed. (4) and the annular insert +51. The inner surface of the groove (4) provided in the mold, especially the lower mold (21), should have a depth from the mold surface (parallel a (aJ and Inside, the parallel part (the inclined part (1) that slopes continuously in the direction of gradually narrowing the width with respect to aJ) is formed. Annular insert (5) or (6)
For example, the left side of the figure corresponds to the annular insert (51) in FIG. 2, and the right side corresponds to the annular insert (51) in FIG. 6], but some of them are still similar to the old parallel part (a
The part facing J is a part (a) parallel to the parallel part (a)
', and a gap (0) of 0.1 to 3 m is maintained between them, and in the interior that is continuous with the parallel part above, the inclined part (corresponding to bJ) of the groove (4) sloped part (
There is substantially no gap between the slopes (b) and (b)'. These annular inserts 151. +61 is buried and fixed in a (4) and when the vulcanized bottom mold is made, a protrusion of the required thickness is made in the curve @ (C), but both inclined parts Cb
) (There is almost no flow in bJ', and even if there is, when the tire is taken out, the root will protrude while maintaining the required thickness.Thus, the protrusion should have an appropriate thickness for cutting. It is easy to cut in the cutting and finishing process after cutting and cutting, and tires with a good finished surface can be manufactured. ◎ The illustrated example shows grooves (4) formed on the side of the lower mold or side When protectors are provided on both sides, a similar configuration may be provided on the upper mold, and the present invention includes both cases. [Effects of the Invention] X: The invention provides a tire with side protectors as described above. In the mold for vulcanization molding of
Within the range of ymn, a gap of 0.1 to 3 m is provided between the two as parallel to the tire axis, and the inside is an inclined part with virtually no gap between the two. Because of this, the protrusion of the vulcanized molded tire is made relatively thicker than the previous case where there was no gap at all, and when the tire is taken out from the mold, it is possible to remove it smoothly without cutting it. ``In addition, in the finishing process after taking out, it is easy to cut, which makes the finishing work easy and the finished surface is good.Furthermore, the sloped part is easy to remove when removed from the mold, and the sloped part can be easily removed from the mold. Even if there is an overhang due to force, it will be cut at the same time by an overhang with a thickness of 1 to 15"r 0.1 to 3 mm from the mold surface, and only a thin extrusion as before. This eliminates the difficulty of cutting using a single mold, making it extremely useful as a molding mold for producing multiple types of tires using a single mold.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view of the main part of the invention mold, showing different annular inserts on the left and right sides. Figure 2 is a cross-sectional schematic diagram showing how the great invention mold is used;
The figure is an enlarged view corresponding to FIG. 1 showing the conventional manner in which the groove and the annular insert are embedded. 11J..., mold, +2+...lower mold, f3)...
・Upper mold 1+41...In addition, , +51161 river annular insert. (aJ...Groove parallel error, (bJ...Groove inclination'a error. (aJ'...Annular insert parallel error. The gap between parallel and evil.

Claims (1)

[Claims] 1. In a mold for vulcanization molding a tire having a side protector formed by protruding a part of the tire sidewall over the entire circumference on at least one side, the side of the mold forming the side protector. Over the entire circumference of the part, within a range of 1 to 15 mm from the surface, there is a parallel part that is parallel to the axis of rotation of the tire, and the inside part has a groove with side surfaces consisting of a continuous gradually narrowing part at an angle with respect to the axis of rotation. and the surface within the groove is female-shaped relative to the shape of the sidewall of the tire, and the parallel portions of the groove are spaced by 0.1 mm between the parallel portions of the groove.
1. A mold for a tire with a side protector, characterized in that an annular insert having a cross-sectional shape with a gap of ~3 mm and substantially no gap in the inclined part is embedded and fixed by means that can be easily attached and detached. 2. The mold for a tire with a side protector according to claim 1, wherein the surface of the annular insert has a female shape corresponding to the shape of the sidewall of a tire without a side protector. 3. The mold for a tire with a side protector according to claim 1, wherein the surface of the annular push-in body has a raised shape and a female shape corresponding to the shape of the side protector of different sizes.