JPH0717523U - Tire molding vulcanization mold - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a mold that does not form spews. [Structure] A tire molding vulcanization mold 1 configured by joining a plurality of segments 2, wherein each of the above-mentioned segments 2 has a depth dimension which is different from that of a joining surface 3 to which adjacent segments 2 are joined. It is characterized by having a plurality of uniform gaps 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a tire for effectively exhausting gas trapped between the die-molded surface of the tire-molding and vulcanizing mold and the unvulcanized tire mounted on the tire-molding and vulcanizing mold. The present invention relates to a mold for vulcanization.

[0002]

[Prior art and its problems]

 In a well-known tire molding apparatus, an unvulcanized tire is loaded into a tire-molding vulcanization mold (hereinafter simply referred to as a mold), heated and pressurized from inside and outside of the mold, and vulcanized. Molded. At this time, in order to effectively exhaust the gas trapped between the mold surface of the mold and the unvulcanized tire, the mold has a diameter of 0. Innumerable vent holes from 6 mm to 1.8 mm are drilled. However, while the ventilation small holes help release the gas during vulcanization, a part of the rubber material of the unvulcanized tire is also extruded through the ventilation small holes, and a myriad of vulcanized tire surfaces are formed. Form elongated protrusions called spews. Such small protrusions must be cut in the final step of tire manufacturing in order to improve the appearance of the tire. Therefore, the conventional mold has a problem that a device for cutting the small protrusions is required. The present invention has been made to solve such problems, and an object thereof is to provide a mold that does not form the small protrusions.

[0003]

[Means for Solving the Problems]

 The present invention is a tire-molding vulcanization mold, which is constructed entirely by abutting a plurality of segments. Each of the above-mentioned segments is an abutting surface that abuts between adjacent segments. The tire has a contact surface on which a plurality of irregularities having non-uniform depth dimensions are formed, and when the above contact surfaces are brought into contact with each other to combine the respective segments, the tire is molded from the inside of the vulcanization mold. It is characterized in that a ventilation hole communicating with the outside of the mold for vulcanization is formed.

The unevenness may be formed by blasting with metal beads, and the depth dimension of the unevenness is 0.02 mm to 0.06 mm, and the depth of each groove is The formation pitch may be 0.3 mm to 0.5 mm.

[0005]

[Action]

 With this configuration, the contact surface having a plurality of concavities and convexities can be formed at the position where the recesses face each other by contacting the contact surfaces with each other in each segment. Form a space. Since a plurality of the above-mentioned unevenness is formed at any place on the contact surface, the number of the above-mentioned gaps communicating from the inside of the tire molding and vulcanizing mold to the outside is limited, and the route of the above-mentioned gaps is curved. Moreover, the depth dimension of the unevenness is set to the above-mentioned dimension. Therefore, the abutting surface on which the above-mentioned unevenness is formed serves to effectively exhaust the gas trapped between the die-molded surface and the above-mentioned unvulcanized tire, while preventing the formation of small protrusions on the tire surface. To do.

[0006]

【Example】

 An embodiment of the mold of the present invention will be described below with reference to the drawings. The mold 1 in this embodiment is a mold for molding the tread portion of the tire as shown in FIGS. 1 and 2, and the tread portion is generally a complicated pattern, so the material is cast. It is an aluminum alloy, for example, an AC-4 material specified in JIS, and is die cast. The mold 1 has an annular shape as a whole and is cut along a plurality of cutting lines including the center line of the mold 1 to be divided into a plurality of segments 2. Therefore, each segment 2 has a fan-shaped planar shape. The mold 1 for one tire is divided into about 50 segments 2. Thus, the mold 1 is divided into a plurality of segments 2, so that the contact surface of each segment 2 can be utilized as follows.

The contact surfaces 3 on both sides of each segment 2, which is a cut surface that divides the die 1, are subjected to a blast treatment as described below. The segment 2 is fixed on the table, and a steel ball having a diameter of 1.0 mm to 1.2 mm made of, for example, soft iron and having a Vickers hardness of 830 Hv collides with the contact surface 3 at a right angle. The blasting gun is used to blast the entire contact surface 3 for 30 to 60 seconds. As a result of this blasting process, a plurality of concave portions 4 and convex portions 5 are formed on the contact surfaces 2 on both sides of the segment 2 as shown in FIG. 3, and from the top 5a of the convex portion 5 to the valley 4a of the concave portion 4. The depth dimension which is the dimension of 0.02 mm to 0.06 mm is, for example, the pitch which is the dimension between the peaks of the adjacent convex portions 5 is 0. It becomes 3 mm to 0.5 mm.

The above-mentioned annular mold 1 is formed by bringing the respective contact surfaces 3 into contact with the respective segments 2 whose contact surfaces 3 have been blasted. When the mold 1 is formed in this manner, the concave portions 4 and the convex portions 5 on the contact surface 3 of each of the segments 2 that are randomly formed are recessed on the contact surface 3 between the adjacent segments 2 that contact each other. 4 and the convex portion 5 contact each other, or the concave portion 4 and the concave portion 4 face each other, or the convex portion 5 and the convex portion 5 contact each other. Therefore, as shown in FIG. 4, when the convex portions 5 come into contact with each other, the dimension between the contact surfaces 3 of the adjacent segments 2 is 0.04 mm to 0.12 mm. A gap 6 is formed. Further, by performing the blasting treatment under the above-mentioned conditions, the direct connection ratio of the gap 6 becomes 20% to 30%. Further, since the concave portions 4 and the convex portions 5 are formed at random, the path of the gap 6 becomes curved. The above-mentioned direct connection ratio means the ratio of the above-mentioned gap 6 which can communicate from the inner surface 2a of the mold to the outer surface 2b in the section L shown in Fig. 1 in all the gaps 6 formed on the contact surface 3. . Further, the above direct connection rate can be measured as follows. The two segments 2 having the gap 6 formed therebetween are brought into contact with each other at the contact surface 3, and along the joining line on the inner surface 2a of the two segments 2, water mixed with acetone or alcohol is used as a dropper in the above L section. Run away. Then, when the joining of the two segments 2 is released, it is obtained from the area of the liquid adhering to the contact surface 3. For example, if the area of the liquid adhering to the contact surface 3 is 70% to 80% of the total area of the contact surface 3, the direct coupling rate can be determined to be 20% to 30%.

The operation of the mold 1 in which the gap 6 is formed in this way will be described below. Each segment 2 is combined with a mold for forming a sidewall of a tire in the same manner as a normal mold for molding a tread portion to form a mold 1, and a tire is vulcanized by a known technique. The process is performed. When performing this vulcanization process, the gas trapped in the tire tread portion passes through the gap 6 formed in the contacting contact surface 3 of each adjacent segment 2 from the inner peripheral side of the annular mold 1 to the mold. Exhausted to the outside. As described above, the size of the gap 6 is 0.12 mm at the maximum, and the direct connection ratio of the gap 6 is 20% to 30%. Furthermore, the gap 6 is bent, and the gas flows along the bent path. No spew is formed as it is exhausted.

[0010]

[Effect of device]

 As described in detail above, the present invention according to claims 1 to 3 has the following effects. By contacting the contact surfaces with each other in each segment to form a mold, a gap is formed in a portion of the unevenness formed on the contact surface where the recesses face each other. Since the unevenness is formed in plural at arbitrary positions on the contact surface, the number of the gaps communicating from the inside to the outside of the tire molding vulcanization mold is limited, and the route of the gaps is bent, Furthermore, by setting the depth dimension of the unevenness to the above-mentioned dimension, the clearance dimension is as small as 0.04 mm to 0.12 mm, so the gas in the tire tread portion is exhausted to the outside of the mold through the above clearance, The rubber material of the tire never enters the gap. Therefore, it is possible to prevent the formation of small protrusions on the tire surface by using a mold having a contact surface with the above-mentioned unevenness, and to eliminate the trouble and equipment for cutting the small protrusions in the final step. You can

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a segment constituting a tire-molding vulcanizing mold of the present invention.

FIG. 2 is a perspective view showing a part of the tire-molding vulcanizing mold, in which a plurality of the segments shown in FIG. 1 are arranged in contact with each other.

FIG. 3 is a cross-sectional view showing a contact surface of the segment shown in FIG.

FIG. 4 is a cross-sectional view of adjacent contact surfaces of the segments.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal mold | die for tire molding vulcanization, 2 ... Segment, 3 ... Contact surface, 4 ... Recessed part, 5 ... Convex part, 6 ... Clearance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B29L 30:00

Claims (4)

[Scope of utility model registration request] 1. A tire-molding vulcanization mold, which is constructed as a whole by abutting a plurality of segments, wherein each of the above-mentioned segments is an abutting surface abutting between adjacent segments. Has a contact surface on which a plurality of irregularities having a non-uniform depth dimension are formed, and when the segments are combined by contacting the contact surface, A tire molding and vulcanization mold characterized in that a vent hole is formed to communicate with the outside of the tire molding and vulcanization mold. 2. The tire-molding vulcanizing mold according to claim 1, wherein the irregularities are formed by blasting with metal beads. 3. The tire molding according to claim 1, wherein a depth dimension of the unevenness is 0.02 mm to 0.06 mm, and a forming pitch of each groove is 0.3 mm to 0.5 mm. Mold for vulcanization. 4. The direct connection rate of the ventilation holes is 20% to 30.
The mold for vulcanization of tire according to claim 1, wherein the mold is vulcanization.