JP4788254B2 - Tire vulcanization mold - Google Patents

Description

  The present invention relates to a tire vulcanization molding die, and more specifically, a tire vulcanization molding that can be stably taken out without damaging or deforming the tire when the molded tire is taken out from the die. It relates to molds.

  As tire vulcanization molds, two-part molds and sectional molds are widely used. The two-divided mold includes a pair of mold bodies divided in the tire axial direction and a tread ring for forming a tire tread portion, and the tread ring is embedded in the mold body. . On the other hand, a sectional type mold includes a pair of side plates for forming tire side portions and a plurality of sectors for forming tire tread portions, and these side plates and sectors are containers that are ancillary equipment of a vulcanizer. It is used by incorporating it into

  Although the above-described two-part mold is inexpensive, the groove-forming convex part on the inner surface of the mold rubs against the tire tread part when releasing the vulcanized tire, so that the tread part has a rubber chip or a tire deformation. There is a drawback that product failure is likely to occur. On the other hand, since the sector type mold can move the sector for forming the tire tread part in the tire radial direction, the tread part has a rubber chipping or tire tread like the two-part type mold. Although there is a low possibility of causing a product failure such as deformation, there is a drawback that the operation mechanism and structure of the vulcanizing apparatus become complicated and the vulcanizing apparatus itself becomes expensive.

  Then, the simple sectional type metal mold | die provided with the function which enables a sector to move to a tire radial direction similarly to a sectional type metal mold | die without requiring expensive equipment is proposed (for example, patent documents) 1).

  As shown in FIGS. 4A, 4B, and 4C, this simple sectional type tire vulcanization molding die 20 has a pair of two halves having a direction dividing surface perpendicular to the tire axial direction. The mold main bodies (upper mold, lower mold) 21 and 22 and a plurality of sectors 23 arranged in the portions responsible for forming the tire tread portions of the mold main bodies 21 and 22 are provided. Sliding surfaces that are inclined with respect to the tire axial direction are formed on the portions of the mold bodies 21 and 22 where the sectors 23 are incorporated. The sectors 23 slide along the sliding surfaces of the mold bodies 21 and 22. By doing so, it is movable in the tire radial direction and the tire axial direction. In addition, the mold main bodies 21 and 22 incorporate a plurality of springs 24 for projecting the sectors 23 out of the mold main bodies 21 and 22.

  As shown in FIG. 4 (a), the simple sectional type mold configured as described above has the spring 24 compressed and the sector 23 retracted into the mold bodies 21 and 22, respectively, as shown in FIG. It becomes a state and forms a predetermined tire molding space.

  On the other hand, in the open mold state, as shown in FIGS. 4B and 4C, the sector 23 projects out of the mold bodies 21 and 22 by the urging force of the spring 24, whereby the sector 23 is tire diameter. Move outward in the direction. As described above, the simple sectional type mold moves the sector 23 in the tire radial direction based on the biasing force of the spring 24, so that the product failure such as the lack of rubber in the tread portion or the deformation of the tire can be achieved while having a simple device configuration. Can be prevented.

  However, when the above-mentioned simple sectional type mold is attached to the BOM vulcanizer, the mold body (upper mold, lower mold) 21 and 22 is separated from the mold body (upper mold) 21 → mold. The order of the mold body (lower mold) 22 is basic.

  Further, when the tire W is taken out from the mold main bodies (upper mold, lower mold) 21 and 22 after vulcanization molding, the mold releasing operation is performed simultaneously with the mold main bodies (upper mold and lower mold) 21 and 22. Therefore, as shown in FIG. 4 (c), if the releasability of some sectors 23 is worse than that of other sectors 23, the tire W will be in an unstable state, and the tire tread portion may have a lack of rubber, There was a possibility of inducing product failure such as deformation.

  Furthermore, when the mold release property on the mold main body (upper mold) 21 side is extremely worse than the mold main body (lower mold) 22 side, the tire W tends to be attached to the mold main body (upper mold) 21. There is a problem that the tire W cannot be taken out.

And since the conventional simple sectional type mold has low durability, it is not suitable for production of general tires with a large production volume.
Japanese Patent Laid-Open No. 9-239735

  This invention pays attention to such conventional problems, and provides a tire vulcanization molding die that can be taken out in a stable state without damaging or deforming the tire when the molded tire is taken out from the die. It is intended to do.

In order to achieve the above object, the present invention is configured so that the stroke length in the tire radial direction of each sector attached to each of the two divided mold bodies is different by the projecting means , and the tire after vulcanization molding is formed. When taking out from the mold body, the stroke length in the tire radial direction of each sector of the divided mold body is set to the sector stroke length on the side to be released first (L1), and the sector stroke length to be released later on ( L2) When (G) is the maximum tire groove depth formed in the sector, (L1)>(G)> (L2)
The gist is that the relationship between (L2) and (G) is set to be as follows.
(0.8G) ≧ (L2) ≧ (0.4G)

Here, in the tire vulcanization mold, a ring-shaped plate is inserted between the sector and the projecting means so as to straddle all sectors aligned in the tire circumferential direction, and the sector is indirectly connected through this plate. It is comprised so that it may urge.

The relationship between (L2) and (G) is set to be as follows.
(0.8G) ≧ (L2) ≧ (0.4G)

Further, the projecting means of said sectors, Ru coil spring or fluid cylinders der.

  By configuring the present invention as described above, when the molded tire is taken out from the mold, the tire can be taken out in a stable state without being damaged or deformed.

According to the present invention, the stroke length in the tire radial direction of each sector attached to the mold body divided into two as described above is configured to be different by the protruding means , and the tire after vulcanization molding is formed into a mold. When removing from the main body, the stroke length in the tire radial direction of each sector of the divided mold main body is the sector stroke length on the side to be released first (L1), the sector stroke length to be released later (L2) When the maximum tire groove depth formed in the sector is (G), (L1)>(G)> (L2)
And the relationship between (L2) and (G) is set so that (0.8G) ≧ (L2) ≧ (0.4G). When removing the tire from the mold body, the side to be released from the tip of the divided mold body can be surely released from the tire, so that the tire can be in a stable state without being damaged or deformed There is an effect that can be taken out.

  As a result, the sliding parts that support the sector are less likely to loosen or be damaged, and the durability can be improved. In addition, the improved durability produces a simple sectional mold that is inexpensive and has few product failures. It can be applied to the production of general tires with a large amount.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional front view of a simple sectional type tire vulcanization molding die embodying the present invention, and FIG. 2 is a sectional view of a die body (lower mold) of the tire vulcanization molding die. The type of tire vulcanization mold includes a pair of bifurcated mold main bodies 1 and 2 (upper mold and lower mold) having divided surfaces in a direction orthogonal to the tire axial direction XX, and these molds. And a plurality of sectors 3 arranged in a portion responsible for forming the tire tread portion Wa of the main bodies 1 and 2. The plurality of sectors 3 are divided into a plurality in the tire circumferential direction, and are configured in a ring shape in a combined state.

  Sliding surfaces that are inclined with respect to the tire axial direction XX are formed in the portion of the mold body (upper mold, lower mold) 1 and 2 where the sector 3 is incorporated. By sliding along the sliding surfaces 1a and 2a, the tire W is movable in the radial direction YY and the tire axial direction XX.

  A guide 5 extending in the tire axial direction XX is formed on the sliding surface 3a of the mold main bodies 1 and 2, and the sliding surface of the sector 3 contacting the mold main bodies 1 and 2 is engaged with the guide 5. A mating groove 6 is formed. The guide 5 and the groove 6 have cross-sectional shapes that mesh with each other, and restrict the detachment of the sector 3 from the sliding surfaces of the mold bodies 1 and 2.

  The mold bodies 1 and 2 are provided with projecting means 4 for projecting the sectors 3 to the outside of the mold bodies 1 and 2, respectively. As the projecting means 4, in this embodiment, a coil spring is used. Although used, it is also possible to use fluid cylinders such as air cylinders or hydraulic cylinders.

  In the embodiment of the present invention, as will be described later, the sector stroke length is adjusted by adjusting the protruding pressure of the protruding means 4 provided on each of the two divided mold bodies 1 and 2.

  In the tire vulcanization mold, a ring-shaped plate 7 is inserted between the sector 3 and the protruding means 4 so as to straddle all the sectors 3 arranged in the tire circumferential direction as shown in FIG. Has been. The plate 7 can move in the tire axial direction together with the sector 3. That is, the protruding means 4 does not directly bias the sector 3 but indirectly biases the sector 3 via the plate 7.

In this invention, when the tire W after vulcanization molding is taken out from the mold bodies 1 and 2, the stroke length in the tire radial direction YY of each sector 3 of the divided mold bodies 1 and 2 is separated first. When the sector stroke length on the side to be molded is (L1), the sector stroke length to be released later is (L2), and the maximum groove depth formed in the sector 3 is (G),
(L1)>(G)> (L2)
It is comprised so that it may become the relationship of these.

  The relationship between (L2) and (G) is set such that (0.8G) ≧ (L2) ≧ (0.4G).

  As described above, by setting the relationship between (L2) and (G) to be (0.8G) ≧ (L2) ≧ (0.4G), the influence of the sector of the mold main body (upper mold) 1 can be reduced. Without receiving, the tire W can be reliably left on the mold body (lower mold) 2 side. Further, by setting (L2) ≧ (0.4G), the tire W at the time of releasing from the mold main body (lower mold) 2 is surely prevented from being damaged by rubbing with the groove forming convex portion on the inner surface of the mold. Can escape.

  In the embodiment of the present invention, the side to be released first is the mold body (upper mold) 1 and the mold body (lower mold) 2 on the side to be released later is not limited to this embodiment. The mold body (lower mold) 2 may be the side to be released first, and the mold body (upper mold) 1 to be released later.

  In this embodiment, the adjustment of the sector stroke length is performed by adjusting the protrusion pressure of the protrusion means 4 provided on each of the two divided mold bodies 1 and 2. Specifically, when a coil spring is used, the spring pressure of the protruding means 4 provided on the mold bodies 1 and 2 is adjusted, and when a fluid cylinder such as an air cylinder or a hydraulic cylinder is used, This is done by adjusting the discharge pressure of the cylinder.

  Next, the operation of the above-described simple sectional type tire vulcanization mold will be described with reference to FIGS.

  In the closed state of the tire vulcanization mold, as shown in FIG. 3A, the spring 4 is compressed and the sector 3 is retracted into the mold bodies 1 and 2, respectively. A tire forming space is formed.

  On the other hand, in the open mold state after vulcanization molding, as shown in FIGS. 3A and 3B, the stroke length is set in advance, and the sector stroke length on the side to be released first is set to (L1) and sector 3. The projecting means 4 is formed so that the relationship (L1)> (G)> (L2) is established, where (G) is the maximum tire groove depth to be formed, and (L2) is the sector stroke length to be released later. Since the spring pressure is adjusted, the sector 3 of the mold body 1 (upper mold) projects out of the mold body 1 due to the spring pressure of the projecting means 4 simultaneously with the start of mold opening. As a result of moving outward in the direction, the groove-forming convex portion on the inner surface of the mold is released from the tire tread portion Wa when the vulcanized tire W is released (see FIG. 3B).

  Then, until the sector 3 of the mold body 1 (upper mold) is completely released, the groove forming convex portion of the sector 3 of the mold body 2 (lower mold) is a tire as shown in FIG. Since the tire W is engaged with the tread portion Wa, the tire W may be caught and tilted or unstable, as in the conventional case, leading to a product failure such as a lack of rubber in the tire tread portion or deformation of the tire W. Can be prevented and the tire W can be easily taken out.

  That is, by configuring as described above, it is possible to increase the mold release resistance of the sector that has been released later, and the mold release that has been released first can be performed reliably. . As a result, it is possible to prevent the occurrence of a vulcanization failure such as a sipe cut at the time of mold release on the side that has been released later.

〔Example〕
Using the 145 / 70R12 STL pattern, change the size of L2 / G and perform vulcanization molding for each 100 pieces in a BOM vulcanizer, and investigate the number of unstable states and the number of damaged tires. did. The results of this investigation are shown in Table 1 below.

  As a result of the above investigation, if L2 is within the range of (0.8G) ≧ (L2) ≧ (0.4G), the tire will not fall into an unstable state during the mold release, and damage may occur. It is shown that there is no occurrence of.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional front view of a simple sectional type tire vulcanization molding die embodying the present invention. It is sectional drawing of the metal mold body (lower mold) of a tire vulcanization mold. (A)-(c) is explanatory drawing which shows the tire mold release operation | movement in the simple sectional type tire vulcanization molding metal mold | die of this invention. (A)-(c) is explanatory drawing which shows the tire mold release operation | movement in the conventional simple sectional type tire vulcanization molding metal mold | die.

Explanation of symbols

1 Mold body (upper mold) 2 Mold body (lower mold)
3 Sector 3a Sliding surface 4 Protruding means 5 Guide 6 Groove 7 Plate W Tire Wa Tire tread portion XX Tire axial direction YY Tire radial direction 20 Tire vulcanization mold 21 Mold body (upper mold) 22 Mold body (lower mold)
23 Sector 24 Spring

Claims (3)

A pair of two mold main bodies having a split surface in a direction perpendicular to the tire axial direction, and a plurality of mold main bodies arranged at a portion responsible for forming a tire tread portion of the mold main body, and a plurality in the tire circumferential direction A plurality of divided sectors, each of which is slidably accommodated in the tire radial direction and the tire axial direction with respect to the mold body, and a protrusion for projecting each sector to the outside of the mold body In the tire vulcanization mold provided with means,
Stroke lengths in the tire radial direction of each sector respectively attached to the two-divided mold main bodies are configured to be different from each other by the protruding means, and are divided when the vulcanized tire is taken out from the mold main body. The tire radial stroke length of each sector of the mold body is set to the sector stroke length on the side to be released first (L1), the sector stroke length to be released later (L2), and the maximum tire to be formed in the sector When the groove depth is (G),
(L1)>(G)> (L2)
And a tire vulcanization mold in which the relationship between (L2) and (G) is set as follows.
(0.8G) ≧ (L2) ≧ (0.4G)   In the tire vulcanization mold, a ring-shaped plate is inserted between the sector and the projecting means so as to straddle all sectors aligned in the tire circumferential direction, and the sector is indirectly biased through this plate. The tire vulcanization molding die according to claim 1 configured to do so.   The tire vulcanization mold according to claim 1 or 2, wherein the projecting means of the sector is a coil spring or a fluid cylinder.

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