JP2018192722A - Mold for tire vulcanization - Google Patents

Abstract

To more effectively reduce rubber biting between a tread mold and a side mold when the molds are closed.SOLUTION: A first abutting surface 2S of a side mold 2 and a second abutting surface 5S of a segment 5 include inclined surfaces 6 and 7 inclining to the inner side in the radial direction towards the inner side in the tire axis direction. The side mold 2 has the first abutting surface 2S and has a movable mold part 15 retained by a mold body 16 such as to be relatively movable inwardly and outwardly in the tire axis direction between a reference position P0 and a first position Pa in the inner side in the tire axis direction than the reference position P0.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tire vulcanization mold for suppressing rubber biting of a raw tire between a tread mold and a side mold when the mold is closed.

  Patent Document 1 below proposes a tire vulcanization mold that suppresses rubber biting of a green tire between a tread mold and a side mold when the mold is closed.

  In the proposed tire vulcanizing mold, when the diameter of the tread mold is reduced, the inclined surface of the piece provided on the side mold and the inclined surface of the segment slide while abutting each other. For this reason, the gap formed between the segment and the piece is reduced, and the rubber of the raw tire that is to be caught in the gap is pushed back inward of the mold by the sliding of the piece.

  However, since the piece is positioned on the outer side in the tire axial direction, the inner surface of the mold becomes concave at the piece. Therefore, there is a tendency that a little rubber is left between the segment and the piece to form a rubber bite, and further examination is desired.

JP2015-193201A

  An object of the present invention is to provide a tire vulcanization mold that can more effectively suppress rubber biting between a tread mold and a side mold when the mold is closed.

The first invention of the present application is a pair of side molds for forming sidewalls arranged on both sides in the tire axial direction,
A tread mold for forming a tread which is composed of a plurality of segments arranged in an annular shape and can be expanded and contracted, and
Vulcanization molding is performed in a mold closed state in which the first butting surfaces at the radially outer ends of the side molds and the second butting surfaces at both ends in the tire axial direction and radially inner ends of the segments are butted against each other. A tire vulcanization mold to be performed,
Each of the first and second butting surfaces includes an inclined surface portion inclined inward in the radial direction toward the inner side in the tire axial direction,
The side mold is
An annular movable mold portion having the first butting surface;
The movable mold portion can be relatively moved in and out of the tire axial direction between a reference position P0 in the mold closed state and a first position Pa in the mold open state that is inward in the tire axial direction from the reference position P0. Mold body to hold on,
And a first spring means for urging the movable mold portion inward in the tire axial direction.

  In the tire vulcanization mold according to the present invention, the distance L1 in the tire axial direction between the reference position P0 and the first position Pa is preferably 3 to 7 mm.

In the tire vulcanization mold according to the present invention, the segment is
A movable segment portion having said second abutting surface;
The movable segment portion can be relatively moved in and out of the tire axial direction between a reference position Q0 in the mold closed state and a second position Qa in the mold open state that is outside the reference axial position Q0 in the tire axial direction. To hold the segment body,
And a second spring means for urging the movable segment portion outward in the tire axial direction.

  In the tire vulcanization mold according to the present invention, a distance L2 in the tire axial direction between the reference position Q0 and the second position Qa is preferably 3 to 7 mm.

The second invention of the present application is a pair of side molds for forming sidewalls arranged on both sides in the tire axial direction,
A tread mold for forming a tread which is composed of a plurality of segments arranged in an annular shape and can be expanded and contracted, and
Vulcanization molding is performed in a mold closed state in which the first butting surfaces at the radially outer ends of the side molds and the second butting surfaces at both sides in the tire axial direction and the radially inner ends of the segments are butted against each other. A tire vulcanization mold,
Each of the first and second abutting surfaces includes an inclined surface portion inclined inward in the radial direction toward the inner side in the tire axial direction,
The segment is
A movable segment portion having said second abutting surface;
The movable segment portion can be relatively moved in and out of the tire axial direction between a reference position Q0 in the mold closed state and a second position Qa in the mold open state that is outside the reference axial position Q0 in the tire axial direction. To hold the segment body,
And a second spring means for urging the movable segment portion outward in the tire axial direction.

  In the tire vulcanization mold according to the present invention, a distance L2 in the tire axial direction between the reference position Q0 and the second position Qa is preferably 3 to 7 mm.

  In the first invention, the gap between the first butted surface and the second butted surface is gradually reduced by reducing the diameter of the tread mold. In synchronization with this, the inclined surface portion of the first abutting surface slides along the inclined surface portion of the second abutting surface, and the movable mold portion gradually approaches the reference position P0.

  At this time, the movable mold portion is located on the inner side in the tire axial direction from the reference position P0 until the mold is closed. Therefore, the rubber of the green tire to be caught between the first and second butting surfaces is inward of the mold by the movable mold part until the first and second butting surfaces are completely closed. It is suppressed. Thereby, rubber engagement between the first and second butted surfaces, that is, rubber engagement between the tread mold and the side mold can be effectively suppressed.

  In the second aspect of the invention, the inclined surface portion of the second abutting surface is in contact with the first abutting in synchronization with the gradual decrease in the gap between the first abutting surface and the second abutting surface. Sliding along the inclined surface portion of the surface, the movable segment portion gradually approaches the reference position Q.

  At this time, the rubber of the raw tire that is about to be caught between the first and second butted surfaces is pushed back inward of the mold by the movement of the movable segment portion inward in the tire axial direction. Thereby, rubber biting between the first and second butted surfaces can be effectively suppressed.

It is sectional drawing which shows notionally 1st Embodiment of the metal mold | die for tire vulcanization | cure of 1st invention. It is sectional drawing which shows notionally the mold open state of the metal mold | die for tire vulcanization | cure of 1st Embodiment. (A), (B) is a fragmentary sectional view explaining operation | movement with the movable mold part and movable segment in 1st Embodiment. (A), (B) is a fragmentary sectional view explaining the effect of rubber biting suppression in a 1st embodiment. It is sectional drawing which shows notionally 2nd Embodiment of the metal mold | die for tire vulcanization | cure of 1st invention. (A), (B) is a fragmentary sectional view explaining the effect of rubber biting suppression in a 2nd embodiment. It is sectional drawing which shows notionally the metal mold | die for tire vulcanization | cure of 2nd invention. (A), (B) is a fragmentary sectional view explaining the effect of the rubber biting suppression.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 conceptually shows an embodiment of a tire vulcanizing mold 1 (hereinafter sometimes simply referred to as “mold 1”) in the mold closed state Y1. As shown in FIG. 1, the mold 1 includes a pair of side molds 2 for forming sidewalls disposed on both sides in the tire axial direction, and a tread mold 3 for forming treads.

  The side mold 2 is supported by a vulcanizer (not shown) so that at least one side mold 2 can move relative to the other side mold 2 in the tire axial direction. As a result, the side molds 2 and 2 can move close to and away from each other in the tire axial direction.

  The tread mold 3 includes a plurality of segments 5 arranged in an annular shape. Each segment 5 is supported by a vulcanizer (not shown) so as to be movable inward and outward in the radial direction, whereby the tread mold 3 can be expanded and contracted.

  The side mold 2 includes a first butting surface 2S at the radially outer end. Each segment 5 includes a second butting surface 5S on both sides in the tire axial direction and on the radially inner end.

  Then, the raw tire T is vulcanized in the mold closed state Y1 where the first butted surface 2S and the second butted surface 5S are butted against each other.

  The first and second butted surfaces 2S and 5S include inclined surface portions 6 and 7 that are inclined inward in the radial direction toward the inner side in the tire axial direction, respectively.

  As shown in FIG. 2, in this example, the first butting surface 2S includes a small-diameter surface portion 8 on the inner side in the tire axial direction, a large-diameter surface portion 9 on the outer side in the tire axial direction, and the small-diameter surface portion 8 and the large-diameter surface portion 9. The inclined surface part 6 which connects between is provided. Further, in this example, the second butting surface 5S includes the small-diameter surface portion 10 on the inner side in the tire axial direction, the large-diameter surface portion 11 on the outer side in the tire axial direction, and the inclined surface portion that connects between the small-diameter surface portion 10 and the large-diameter surface portion 11. 7 is included.

  The first butting surface 2S and the second butting surface 5S have the same shape. In the mold closed state Y1, the small diameter surface portions 8 and 10 are butted, and the large diameter surface portions 9 and 11 are butted. The inclined surface parts 6 and 7 are abutted.

  In the mold 1A of the first invention, each side mold 2 includes an annular movable mold portion 15, a mold main body 16, and a first spring means 17.

  The movable mold portion 15 is a radially outer end portion of the side mold 2 and has the first butting surface 2S.

  The mold body 16 is the remaining part of the side mold 2 and is adjacent to the movable mold part 15 on the inner side in the radial direction. The mold body 16 holds the movable mold portion 15 so as to be relatively movable in and out of the tire axial direction between the reference position P0 and the first position Pa. The boundary surface 18 between the movable mold portion 15 and the mold main body 16 is a cylindrical surface concentric with the tire shaft, so that the movable mold portion 15 can move relative to the mold main body 16 in and out of the tire axial direction. .

  The reference position P0 is a position of the movable mold portion 15 in the mold closed state Y1, and is a position where the cavity surface of the movable mold portion 15 and the cavity surface of the mold body 16 form a tire forming surface. is there. The first position Pa is the position of the movable mold portion 15 in the mold open state Y2, and protrudes from the reference position P0 by a distance L1 to the inner side in the tire axial direction. The distance L1 is preferably in the range of 3 to 7 mm.

  The first spring means 17 biases the movable mold portion 15 inward in the tire axial direction. In this example, the first spring means 17 is a compression coil spring, and is disposed in, for example, a spring accommodating portion 20 that is recessed in the boundary surface 18 and the mold body 16. In this example, the side mold 2 includes stopper pieces 31 and 32. For example, the stopper piece 31 protrudes from the movable mold portion 15, and the stopper piece 31 comes into contact with the inner surface in the tire axial direction of the spring accommodating portion 20 to stop the movable mold portion 15 at the first position Pa. For example, the stopper piece 32 protrudes from the mold body 16, and the stopper piece 32 comes into contact with the outer end surface in the tire axial direction of the movable mold portion 15, thereby stopping the movable mold portion 15 at the reference position P <b> 0.

  In this example, each segment 5 includes an annular movable segment portion 23, a segment body 24, and second spring means 25.

  The movable segment portion 23 is an outer end portion in the tire axial direction and a radially inner end portion of the segment 5 and has the second butting surface 5S.

  The segment body 24 is the remainder of the segment 5 and is adjacent to the movable segment portion 23 on the radially outer side. The segment body 24 holds the movable segment portion 23 so as to be relatively movable inward and outward in the tire axial direction between the reference position Q0 and the second position Qa. The boundary surface 26 between the movable segment portion 23 and the segment main body 24 is a cylindrical surface concentric with the tire shaft, so that the movable segment portion 23 can move relative to the segment main body 24 in the tire axial direction. .

  The reference position Q0 is a position of the movable segment portion 23 in the mold closed state Y1, and is a position where the cavity surface of the movable segment portion 23 and the cavity surface of the segment body 24 form a tire forming surface. is there. The second position Qa is the position of the movable segment portion 23 in the mold open state Y2, and is retracted by a distance L2 outside the reference position Q0 in the tire axial direction. The distance L2 is preferably in the range of 3 to 7 mm. The distance L2 and the distance L1 are the same.

  The second spring means 25 biases the movable segment portion 23 outward in the tire axial direction. In this example, the second spring means 25 is a compression coil spring, and is disposed in, for example, a spring accommodating portion 27 that is recessed in the boundary surface 26 and the segment body 24. In this example, the segment 5 includes a stopper piece 33. For example, the stopper piece 33 protrudes from the movable segment portion 23, and the stopper piece 33 comes into contact with the outer surface in the tire axial direction of the spring accommodating portion 27, thereby stopping the movable segment portion 23 at the second position Qa. The movable segment portion 23 can stop at the reference position Q0 by interlocking with the movable mold portion 15.

  In the mold 1A of the present example, as shown in FIG. 2, when the tread mold 3 is reduced in diameter, the gap D between the first butted surface 2S and the second butted surface 5S gradually increases. Decrease.

  As shown in FIGS. 3A and 3B, after the inclined surface portion 6 of the first abutting surface 2S and the inclined surface portion 7 of the second abutting surface 5S come into contact with each other, the reduced diameter is linked. Then, the inclined surface portion 6 slides along the inclined surface portion 7. Thereby, the movable mold portion 15 gradually approaches the reference position P0. Similarly, the inclined surface portion 7 slides along the inclined surface portion 6, and the movable segment portion 23 gradually approaches the reference position Q0. At the same time as the gap D becomes 0, the movable mold portion 15 and the movable segment portion 23 reach the reference positions P0 and Q0, respectively, and the mold is closed Y1.

  As described above, the movable mold portion 15 is located on the inner side in the tire axial direction from the reference position P0 until the mold closed state Y1 is reached. Therefore, as shown in FIGS. 4 (A) and 4 (B), the rubber G of the green tire T to be bitten between the first and second butted surfaces 2S and 5S is the first and second butted surfaces. The movable mold portion 15 is held inward of the mold 1 until the space between 2S and 5S is completely closed. Thereby, rubber biting can be effectively suppressed.

  Particularly in this example, the segment 5 has a movable segment portion 23, and this movable segment portion 23 is located on the outer side in the tire axial direction from the reference position Q0 until the mold closed state Y1 is reached. Therefore, even when the rubber G gets over the movable mold portion 15 outward in the tire axial direction, the rubber G can be pushed back to the inside of the mold 1 by the movable segment portion 23. Thereby, rubber biting can be more effectively suppressed.

  The movable segment portion 23 is preferably made of the same material as that of the segment body 24. In particular, aluminum is more preferably used from the viewpoint of thermal conductivity and ease of processing.

  FIG. 5 shows a second embodiment of the mold 1A of the first invention. In the second embodiment, the segment 5 does not include the movable segment portion 23 and the second spring means 25, and the segment body 24 itself forms the segment 5. Other than that, it is the same structure as 1st Embodiment.

  In this case as well, as shown in FIGS. 6A and 6B, as in the first embodiment, the rubber G is movable until the first and second butted surfaces 2S and 5S are completely closed. The portion 15 is held inside the mold 1. Therefore, rubber biting can be effectively suppressed.

  FIG. 7 shows a mold 1B of the second invention. In the mold 1B of the second invention, the segment 5 includes the movable segment portion 23, the segment main body 24, and the second spring means 25 as in the first embodiment. However, the side mold 2 does not include the movable mold portion 15 and the first spring means 17, and the mold body 16 itself forms the side mold 2. Other than that, it is the same structure as 1st Embodiment.

  In this case, as shown in FIGS. 8A and 8B, the movable segment portion 23 is located on the outer side in the tire axial direction from the reference position Q0 until the mold closed state Y1 is reached. Therefore, even when the rubber G gets over the side mold 2 outward in the tire axial direction, the rubber G can be pushed back to the inside of the mold 1 by the movable segment portion 23. Thereby, rubber biting can be effectively suppressed.

  In the case of Prior Art 1, the side mold piece is positioned on the outer side in the tire axial direction from the reference position until the side mold piece is in the mold closed state. Therefore, it is presumed that the rubber easily comes into contact with the second abutting surface, and the effect of suppressing the rubber biting becomes insufficient.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

 A tire vulcanization mold having the basic structure shown in FIGS. And after putting the green tire for forming a pneumatic tire (195 / 60R16) into the mold for tire vulcanization, the mold is closed and closed. Next, the mold was opened without vulcanization, and the state of the rubber bite generated between the tread mold and the side mold was visually observed. When there was a rubber bite, the maximum protrusion amount (rubber bite amount) of the rubber bite tire was measured.

  As shown in the table, it can be confirmed that the tire vulcanization mold of the example can effectively suppress the rubber biting generated between the tread mold and the side mold.

DESCRIPTION OF SYMBOLS 1 Tire vulcanizing mold 2 Side mold 2S First abutting surface 3 Tread mold 5 Segment 5S Second abutting surface 6 Inclined surface portion 7 Inclined surface portion 15 Movable mold portion 16 Mold body 17 First spring means 23 Movable segment portion 24 Segment body 25 Second spring means Y1 Mold closed state Y2 Mold open state

Claims (6)

A pair of side molds for forming sidewalls disposed on both sides in the tire axial direction;
A tread mold for forming a tread which is composed of a plurality of segments arranged in an annular shape and can be expanded and contracted, and
Vulcanization molding is performed in a mold closed state in which the first butting surfaces at the radially outer ends of the side molds and the second butting surfaces at both ends in the tire axial direction and radially inner ends of the segments are butted against each other. A tire vulcanization mold to be performed,
Each of the first and second butting surfaces includes an inclined surface portion inclined inward in the radial direction toward the inner side in the tire axial direction,
The side mold is
An annular movable mold portion having the first butting surface;
The movable mold portion can be relatively moved in and out of the tire axial direction between a reference position P0 in the mold closed state and a first position Pa in the mold open state that is inward in the tire axial direction from the reference position P0. Mold body to hold on,
And a mold for tire vulcanization comprising first spring means for urging the movable mold portion inward in the tire axial direction.   The tire vulcanization mold according to claim 1, wherein a distance L1 in the tire axial direction between the reference position P0 and the first position Pa is 3 to 7 mm. The segment is
A movable segment portion having said second abutting surface;
The movable segment portion can be relatively moved in and out of the tire axial direction between a reference position Q0 in the mold closed state and a second position Qa in the mold open state that is outside the reference axial position Q0 in the tire axial direction. To hold the segment body,
The tire vulcanization mold according to claim 1 or 2, further comprising second spring means for urging the movable segment portion outward in the tire axial direction.   The tire vulcanization mold according to claim 3, wherein a distance L2 in the tire axial direction between the reference position Q0 and the second position Qa is 3 to 7 mm. A pair of side molds for forming sidewalls disposed on both sides in the tire axial direction;
A tread mold for forming a tread which is composed of a plurality of segments arranged in an annular shape and can be expanded and contracted, and
Vulcanization molding is performed in a mold closed state in which the first butting surfaces at the radially outer ends of the side molds and the second butting surfaces at both sides in the tire axial direction and the radially inner ends of the segments are butted against each other. A tire vulcanization mold,
Each of the first and second butting surfaces includes an inclined surface portion inclined inward in the radial direction toward the inner side in the tire axial direction,
The segment is
A movable segment portion having said second abutting surface;
The movable segment portion can be relatively moved in and out of the tire axial direction between a reference position Q0 in the mold closed state and a second position Qa in the mold open state that is outside the reference axial position Q0 in the tire axial direction. To hold the segment body,
And a tire vulcanization mold comprising second spring means for urging the movable segment portion outward in the tire axial direction.   The tire vulcanization mold according to claim 5, wherein a distance L2 in the tire axial direction between the reference position Q0 and the second position Qa is 3 to 7 mm.

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