JPH1034687A - Mold for tire non-skid device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a molding material for a non-skid main body set on a net-molding channel of a mold of a tire non-skid device from moving itself own restoring force and forming the cause of generation of troubles at the time of vulcanization. SOLUTION: Respective small protrusions 20, 22a, 22b, 23a, 23b, 24a, 24b, 25a, 25b, 26a, 26b, 27a and 27b are formed on the bottom faces of net molding channels 12, 13a, 13b, 14a, 14b, 15a and 15b and their crossing sections of a mold 10, and a rubber material on the bottom side of a molding material for a non-skid main body is stuck into respective small protrusions and set on the molding channels. The free movement of the molding material set thereon is prevented by the arrangement to reduce the rate of generation of vulcanization troubles and eliminate the necessity of repairing work for defective sections of setting of the molding material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for press-forming a non-slip body of a net-type tire anti-slip device.

[0002]

2. Description of the Related Art Conventionally, as a non-slip body formed into a net shape, for example, the one shown in FIG. 4 is known. The non-slip body 1 has a flat hexagonal central mesh portion 2 formed in a line on a longitudinal center line, and a rhombic side having a common side of each adjacent central mesh portion 2 on both sides in the width direction. The side mesh portions 3a and 3b are formed, and on both sides in the width direction, triangular outer mesh portions 4a and 4b that share one side of each of the adjacent side mesh portions 3a and 3b with a deformed rhombus. The reticulated mesh portions 5a and 5b are formed alternately adjacent to each other, and linear joining portions 6 and 7 are formed at both ends in the longitudinal direction in the width direction. Further, on the tread portion of the non-slip body 1, spike pins 8a, 8b are provided at every other interval in the longitudinal direction at intersections on the inner side and outer side in the width direction of the central mesh portion 2 and the side mesh portions 3a, 3b. Each is provided in two rows.

[0003] A fastening rope (not shown) is fastened to a locking mesh portion 5a on one side edge in the longitudinal direction of the anti-slip body 1 via a hook, and a locking mesh portion 5b on the other side edge. A hook (both not shown) for hooking a fastener having a rubber band or the like is fixed by caulking. The non-slip body 1 attached to the tire has the side on which the fastening rope fastening hook is attached on the vehicle body side of the tire, and the joints 6, 7 of the non-slip body 1 are connected to each other by the fastening rope. Tied together on the lap,
The side to which the fastening tool hook is attached is arranged outside the tire, and the fastening tool is hooked to the hook and the joints 6 and 7.

[0004] The constituent material of the non-slip body 1 is a reinforcing core such as a synthetic fiber and a rubber material or a synthetic resin material covering the reinforcing core, and is press-formed using a mold. A mold (lower mold) for molding the non-slip body 1 is provided with a molding groove having the same shape and dimensions as the non-slip body 1. For example, an unvulcanized rubber material is provided around a reinforcing core such as a tire cord. Press molding is performed by using a molding material coated with a material and the like, and arranging the material in a net shape along the molding groove of the mold.

[0005]

In forming the above-mentioned non-slip body, when a molding material is directly arranged in a net shape in a molding groove of a press molding die, the molding set in the mesh molding groove is performed. The material has many bent parts, and during the setting operation in the molding groove of the mold, due to the restoring force of the molding material itself, it moves freely at various points of the molding groove and protrudes outside the molding groove, causing a defective setting part Will be.

[0006] When the molding material having a defective setting is formed by press molding as it is, the rubber material of the defective setting is cut off at the mating surface of the upper mold and the lower mold, and the slip after press molding is performed. The reinforcing core is exposed on the surface of the stopper body. For this reason, in many cases, the defective set portion of the molding material set in the mesh forming groove of the mold is reworked, and as a result, not only does the setting work time increase and the productivity is lowered, but also the reworking is performed. During the operation, the spike pin standing in the molding groove may shake and tilt, which may cause an unexpected situation in which a so-called out-of-focus failure is induced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the invention according to claim 1 is to fix a molding material of a non-slip body set in a mesh forming groove of a mold. It is an object of the present invention to provide a mold provided with small projections for preventing movement.

It is an object of the present invention to specify the shape of a small projection in a central mesh forming groove of a mold. It is an object of the present invention to specify the shape of the small projection at the intersection of the center mesh forming groove and the side mesh forming groove of the mold.

[0009]

In order to achieve the above object, each of the claims of the present invention employs the following configuration.

According to the first aspect of the present invention, there is provided a mold for a tire anti-skid device in which a forming groove having a shape and a size corresponding to each mesh portion of a net-shaped anti-slip body is formed. A small projection is provided on the bottom surface of the part forming groove so as to pierce the rubber material on the bottom side of the forming material of the non-slip body set in the forming groove.

According to a second aspect of the present invention, the small projection in the central mesh portion forming groove on the longitudinal center line of the mold is shaped as a kerf forming projection. According to a third aspect of the present invention, the small projections at the intersections between the central mesh forming groove of the mold and the lateral mesh forming grooves on both sides in the width direction are formed by intersecting the small protrusions in the longitudinal direction and the width direction of the mold. It is formed in a shape that is bent in a V-shape along the inner edge of the portion.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a mold according to the present invention, which is a mold (lower mold) for press-molding a mold having the same shape as the anti-slip body of FIG.

The mold 10 is provided with a forming groove 12 corresponding to the central mesh portion 2 of the non-slip body 1 on the center line in the longitudinal direction, and the lateral mesh portions 3a, 3a of the non-slip body 1 on both sides in the width direction. Molding grooves 13a, 13b corresponding to the outer mesh portions 4a, 4b and locking mesh portions 5a, 5b of the non-slip body 1 are provided on both sides in the width direction. 15a, 15b are provided, and the joining portions 6, 7 of the non-slip body 1 are provided at both ends in the longitudinal direction.
Are formed.

Of the forming grooves of the mold 10, small projections having different shapes are provided on the bottom surface of each mesh forming groove in accordance with the arrangement of the forming grooves. The small protrusion 20 provided on the bottom surface of the central mesh portion forming groove 12 orthogonal to the longitudinal center line of the mold 10 has a broken line planar shape, and has a central mesh portion forming groove 12 and a side mesh portion forming groove. The planar shapes of the small projections 22a and 22b at the common portion with the portions 13a and 13b and the small projections 23a and 23b at the common portion of the side mesh portion forming grooves 13a and 13b and the outer mesh portion forming grooves 14a and 14b are respectively groove lengths. Direction, and the planar shape of the small projections 24a, 24b of the outer mesh portion forming grooves 14a, 14b is a linear shape with a very short length in the groove length direction. Small projection 25 of locking mesh part forming groove 15a, 15b
The plane shapes of a and 25b are circular, and both are molded to have a small thickness or small diameter, and are provided at the center of each molding groove.

Also, two types of small projections 26a, 26b and small projections 27a, 27a, provided at the intersections of the central mesh forming groove 12 and the lateral mesh forming grooves 13a, 13b on both sides in the width direction.
27b, one of the small projections 26a, 26b is formed by arranging, in the longitudinal direction and the width direction, a planar shape bent in a letter shape along the inner edge of the intersection, and the other small projections 27a, 26b.
Reference numeral 27b denotes a linear flat shape having a short length in the groove length direction, which is radially arranged at an interval from the center of the intersection.

As a representative one of the above-mentioned small projections, a small projection 20 in the central mesh forming groove 12 is shown in FIG. 2, and a small projection 24a and the central mesh forming groove 12 in the outer mesh forming groove 14a are shown in FIG. FIG. 3 shows the small protrusion 26a at the intersection with the side mesh portion forming groove 13a.

As shown in FIGS. 2 (b), 3 (b) and 3 (c), the cross-sectional shape of these small projections 20, 24a and 26a is extremely low compared to the depth of the forming groove. The head has a mountain shape with a hemispherical surface. The same applies to other small projections other than the above.

FIGS. 2C and 3C show the small projections 20.
The center mesh forming groove 12 provided with the small projections 26a and the state where the non-slip body forming material 30 is set at the intersection of the center mesh forming groove 12 and the side mesh forming groove 13a. The rubber material 31 on the bottom side of the molding material 30 set in each molding groove is respectively attached to the small protrusion 20.
And the small projection 29. The molding material 30 fixed in this way is prevented from freely moving in the molding groove.

When the molding material 30 of the non-slip body is set in the molding groove of the mold 20 having the above-described structure, for example, the uncured rubber material 31 is coated around a string-shaped reinforcing core 32 as the molding material 30. The molding material 30 is repeatedly inserted into the molding groove at one end in the longitudinal direction of the mold 10 from the one end thereof and repeatedly stretched, during which the material 30 is provided at the center of the molding groove. The central portion of the rubber material 31 on the bottom side of the molding material 30 is pierced into the small projection (see FIG. 2C).
In particular, at the intersection of the molding grooves provided with the small projections 26a and 26b, the two widthwise portions of the rubber material 31 on the bottom side of the molding material 30 are respectively connected to the small projections 26a and 26b.
Pierce.

Since the net-shaped molding material 30 set in this way is fixed against the restoring force of itself, free movement in each molding groove is prevented, and the initially set material is set. Press molding is performed in a state where the proper position is securely held.

When setting the molding material 30 of the non-slip body, the spike pins 35a are previously set at predetermined positions at the intersections between the central mesh forming groove 12 and the side mesh forming grooves 13a, 13b of the mold 10. , 35b are erected, and the setting operation proceeds while the molding material 30 is pierced into the spike pins 35a, 35b.

On the tread portion of the non-slip body manufactured by using the above-described mold 10, a narrow groove or a small hole is formed by a group of small projections provided in the forming groove. The narrow grooves formed by the twelve small protrusions 20 have a sawtooth shape and have the same effect as a calf formed on the tire tread surface, so that the same effect as a studless tire is obtained, Therefore, the small projection 20 also has a function as a kerf molding projection. Also, the small projections 26a, 26b at the intersections of the central mesh portion forming groove 12 and the side mesh portion forming grooves 13a, 13b are arranged in a rectangular shape facing each other. The molding material 30 to be formed can be more securely fixed on both sides in the width direction. The molding material 30 of the non-slip body 1 is
The operation of setting the molding material 30 in the molding groove of the mold 10 is repeated instead of directly setting the molding material 30 as described above. Can also be set.

[0023]

EXAMPLE A comparison was made between the non-slip body manufactured using the mold of the present invention and the non-slip body manufactured using the conventional mold in the setting work time of the molding material and the failure rate of the product. The result shown in FIG. 1 was obtained.

The size of the manufactured non-slip body is 205 /
For 65R15 tires.

[0025]

[Table 1]

As shown by the indices in Table 1, when the mold of the present invention is used, it is not necessary to rework the defective setting portion of the molding material. 9% reduction in the setting work time of the molding material, and press molding without reworking the molding material in the part where the setting failure occurred when using the conventional mold,
It has been confirmed that, while the incidence of out-of-focus failure and the occurrence of a failure product in which the reinforcing core is exposed increases, the use of the mold of the present invention can reduce the failure occurrence rate of the product to 40% reduction. .

[0027]

As described above, according to the first aspect of the present invention, the material for forming the non-slip body is provided on the bottom surface of each mesh portion forming groove of the die on which the net-shaped non-slip body is press-molded. Because a small projection that pierces the rubber material at the bottom side of the is provided, the molding material set in the molding groove is strongly fixed in a state where free movement due to its own restoring force is prevented, so the conventional It is not necessary to rework defective parts such as molds, which not only shortens the setting work time and improves productivity, but also causes out-of-focus defects during reworking and reinforcement of the molding material after press forming. The effect that the failure in which the core body is exposed on the surface of the non-slip body is reduced and the production yield is improved.

According to the second aspect of the present invention, in addition to the above-described effects, a serrated narrow groove can be formed on the tread portion of the non-slip body, so that the slip having the same function as a studless tire can be obtained. A stop body can be manufactured.

Further, according to the third aspect of the present invention, the molding material which is set to be overlapped vertically before and after the intersection of the central mesh portion forming groove and the side mesh portion forming groove of the mold has a width direction. Since it is fixed by the small protrusions on both sides, the movement of the molding material at the intersection can be more firmly prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a mold according to the present invention.

FIG. 2 is an enlarged view (a) showing a dotted circular portion of the mold of FIG. 1, a sectional view taken along line AA in FIG. 1 (a), and a mold set in a molding groove of FIG. It is sectional drawing (c) which shows a molding material.

3 is an enlarged view (a) showing a dotted circular portion of the mold of FIG. 1, a sectional view taken along line BB in FIG. 3 (a), and a sectional view taken along line CC in FIG. It is sectional drawing (d) which shows c) and the shaping | molding raw material set in the shaping | molding groove | channel.

FIG. 4 is a plan view showing an example of a net-shaped non-slip body.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 mold 12 central mesh forming groove 13a, 13b side mesh forming groove 14a, 14b outer mesh forming groove 15a, 15b locking mesh forming groove 20 small projection of central mesh forming groove 22a, 22b central mesh Small projections 23a, 23b at common portion between forming groove and side mesh portion forming groove Small protrusions 24a, 24b at common portion between side mesh portion forming groove and outer mesh portion forming groove Small protrusions 25a at outer mesh portion forming groove , 25b Small protrusion 26a, 26b, 27a, 27b of the locking mesh forming groove Small protrusion at the intersection of the central mesh forming groove and the side mesh forming groove 30 Molding material of non-slip body 31 Rubber material of molding material

Claims (3)

[Claims] 1. A mold for a tire anti-skid device in which a forming groove having a shape and a size corresponding to each mesh portion of a net-shaped non-slip body is formed on a bottom surface of each mesh portion forming groove of the mold. A mold for a tire anti-skid device, wherein a small projection is provided to pierce the rubber material on the bottom side of the molding material of the anti-slip body set in the molding groove. 2. A mold for a tire anti-skid device according to claim 1, wherein the small projection in the central mesh portion forming groove on the longitudinal center line of the mold has a shape of a kerf forming projection. 3. Small projections at the intersections of the central mesh forming groove of the mold and the lateral mesh forming grooves on both sides in the width direction are formed at the inner edges of the respective intersections facing each other in the longitudinal direction and the width direction of the mold. The mold for a tire anti-skid device according to claim 1, wherein the mold has a shape that bends in a rectangular shape along the shape.