JPH07314459A - Tire-molding die - Google Patents

Abstract

PURPOSE:To obtain a tire-molding die that can be easily and rapidly cleaned and assembled. CONSTITUTION:A segment 5 is formed by fitting a plurality of pieces 10 to a holder sector 20. Peripheral grooves 22 are formed in a holding surface 21 of the holder sector 20. A stopper 30 is provided in the peripheral groove 22 in position. A positioning pin is projected on the back surface of the piece 10. The piece 10 is positioned with respect to the holder sector 20 by abutting the positioning pin against the stopper provided in the peripheral groove 22 in position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire molding die, and more particularly to a tire molding die which can be easily and quickly cleaned and assembled.

[0002]

2. Description of the Related Art A conventional tire molding die is shown in FIG.
4 (a) vertical split mold, and FIG. 14 (b)
A mold of a radial division type as shown in is known, and in such a mold, gas such as air trapped between the mold and the unvulcanized rubber during tire vulcanization molding. A large number of small holes called vent holes were formed in order to discharge the powder to the outside of the mold. However, the work of providing a large number of such vent holes requires skill and the number of man-hours increases, so that the manufacturing efficiency of the mold is not sufficient, and due to the vent holes, hair-shaped hair called spews on the molded tire surface is formed. Since rubber is generated, it has to be removed, and even after the removal, traces are likely to remain, which causes a problem that the appearance of the tire is impaired and the initial running performance of the tire is impaired. Further, when tire molding is repeated using the mold as described above, the spew may be cut and remain in the vent hole, or the vent hole may be clogged due to accumulation of dirt such as rubber, Had to be cleaned regularly (every hundreds to thousands of moldings). This cleaning had to be performed manually for all the vent holes using a drill or the like, and maintenance of the mold was complicated.

To address such a problem, Japanese Patent Laid-Open No. 4-22
3108 and JP-A-5-220753,
In a segment type tire molding die as shown in FIG. 14 (b), a tread molding portion 1 for imparting a tread pattern to a tire is divided into a plurality of pieces and held by a holder 2, and each of them is used during a mold assembly. It is disclosed that the number of vent holes can be reduced or eliminated by appropriately controlling the adjacent distance between the pieces 1 and providing an air vent gap that prevents the rubber component from being discharged. It is also described that the division of the piece 1 to provide the air vent gap can be applied to a mold as shown in FIG. 14 (a).

[0004]

However, even in a mold in which the above-mentioned pieces are divided and adjacent to each other, if the tire is molded several hundred to several thousand times, as in a normal tire molding mold, the mold is Rubber components adhere to the surface, vent holes, and air bleeding gaps between pieces, impairing the appearance of the resulting tire and reducing the air bleeding effect, so the mold is washed regularly every few hundred to several thousand shots. There is a need to. Generally, when cleaning a tire molding die, glass beads,
Blasting is performed by blasting powder such as iron powder.In the above-mentioned piece division mold, in order to remove dirt such as rubber that has entered the air vent gap, each piece is removed from the holder and blasted. Had to do.

On the other hand, the tread pattern of a tire has a pattern pitch (a unit obtained by dividing the circumference of the tire at a predetermined interval) in order to prevent vibration and noise of the tire when the vehicle is running. It is often formed by making the patterns forming the patterns different in a similar state and arranging them in a desired order (generally,
In many cases, the circumference of the tire is divided at a pitch of 50 or more, and three or more types of pitch lengths are adopted and arranged. ). Therefore,
As the pieces of the tire molding die, those having different pattern pitches need to be arranged adjacent to each other in order, and careful attention must be paid to the die assembly after cleaning, which is a time-consuming problem. The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a tire-molding die that can be easily and quickly cleaned and assembled. It is in.

[0006]

Means for Solving the Problems As a result of earnest research to achieve the above object, the present inventor can achieve the above object by providing unevenness having selectivity on the back surface of the piece and the holding surface of the holder. The present invention has been completed and the present invention has been completed. Therefore, the tire molding die of the present invention is a tire molding provided with a plurality of annular pieces as a whole that impart a tread pattern to a product tire and a holder that can be mounted adjacent to each other in the circumferential direction. In the mold, the piece has a convex portion on its back surface, and the holding surface of the holder is provided with a circumferential groove for guiding the convex portion of the piece. It is characterized in that it comes into contact only with a stopper arranged at a predetermined position of the circumferential groove. Further, another tire molding die of the present invention,
In a tire molding die provided with a plurality of pieces having an annular shape as a whole for imparting a tread pattern to a product tire and a holder capable of mounting these pieces adjacent to each other in the circumferential direction, a back surface of the piece and a corresponding one. The holding surface of the holder in contact has a concave portion or a convex portion, and the concave portion or the convex portion on the back surface of any of the pieces is fitted only with the convex portion or the concave portion at a predetermined position on the holding surface of the holder. To do.

[0007]

In the tire molding die of the present invention, a convex portion is provided on the back surface of a plurality of pieces to which the tread pattern is applied, while a circumferential groove is provided on the holding surface of the holder that holds the pieces adjacent to each other. A stopper that comes into contact with the convex portion is provided at a predetermined position of the circumferential groove. Then, by making the protruding height of the convex portion and the height of the stopper different between the pieces or stoppers or by disposing the convex portion at different positions, the convex portion of the predetermined piece can only contact the stopper at the predetermined position. I chose Therefore, when assembling the tire molding die, the predetermined piece is positioned at the predetermined position of the holder.

Further, in another tire molding die of the present invention, a concave portion or a convex portion is provided on the back surface of the piece, and the convex portion or the concave portion fitted with the concave portion or the convex portion is provided at a predetermined position on the holding surface of the holder. Set up in. Furthermore, by changing the position and shape of the recess or protrusion between the types of pieces, and by disposing the position of the protrusion or recess to be fitted with this in the holder, the predetermined piece is placed at the predetermined position of the holder. It was positioned.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. (Embodiment 1) FIG. 1 is a perspective view partially showing an embodiment of a tire molding die of the present invention. FIG. 14 (b) is shown in FIG.
1 shows a part of a segment type mold, and a plurality of pieces 10 are attached to a holder sector 20 to form a segment 5. In this embodiment, while sliding the back surface 13 of the piece 10 and the holding surface 21 of the holder 20 (see FIG. 1), the piece 10 is moved in the circumferential direction indicated by an arrow A in the figure to be mounted on the holder sector 20. The fixing of the piece 10 to the holder sector 20 is
Although not particularly limited, as shown in FIGS. 3A to 3C, at both ends of the segment 5, the side surfaces of the piece 10 and the sector 20 are counterbored to form a bolt 50, a washer 51, and a seat 52. It can be carried out by fixing it using the like. When the seat 52 has elasticity, it can be more preferably fixed.

The piece 10 forms a tread pattern for the entire tire with all pieces, and a convex pattern for forming the tread pattern on the tire is formed on the molding surface 11 thereof (not shown). .). In addition, pieces having different pattern pitches are often arranged adjacent to each other in order to prevent vibration and noise of the tire during traveling. In this embodiment, eight pieces 10 having three kinds of pitches S, M, and L are provided. The rows (8 sheets) are arranged in two rows above and below (see FIG. 4). The numbers shown on the upper and lower edges of the holder sector 20 indicate the column numbers of the pieces 10. The pieces 10 are arranged adjacent to each other with their adjacent surfaces 12 contacting each other, but the air bleeding gap during tire vulcanization molding allows a part of the adjacent surface 12 to penetrate from the molding surface 11 to the back surface 13. Typically 0.02m
It can be provided by grinding about m. Alternatively, the air vent gap can be provided by inserting a spacer of about 0.02 mm between the pieces 10 (between a part of the adjacent surfaces 12). Also,
The ten-point average roughness Rz 3 to 50 for a part or the whole of the adjacent surface 12
It is also possible to impart an air bleeding effect by processing in a state having a processed surface roughness of about μm. In addition,
It is preferable that at least one such air bleeding gap is arranged in a portion forming a land area in a tread portion of a product tire. Further, although the appearance problem remains in the product tire, if a groove penetrating from the molding surface 11 to the back surface 13 is provided in the adjacent surface 12 and this through groove is applied as a substitute for the conventional vent hole, the through groove is adjacent. Since it exists on the surface 12, it is not necessary to clean with a drill or the like, and the cleaning efficiency can be improved.

Next, the positioning mechanism for the holder 20 of the piece 10 which characterizes the present invention will be described. First, on the holding surface 21 of the holder sector 20, three circumferential grooves 22 extending in the circumferential direction A are formed in upper and lower two stages, respectively.
A plate-shaped stopper 30 is provided at a predetermined position of these circumferential grooves 22. On the other hand, as shown in FIG. 2, on the back surface 13 of the piece 10, the pin holes 14 are aligned with the positions of the circumferential grooves 22.
Is formed, and a convex portion is formed by inserting a positioning pin 15 having a diameter slightly smaller than the width of the circumferential groove 22 into the pin hole 14.

When mounting the piece 10 on the sector 20, the positioning pin 15 of the piece 10 is moved in the circumferential direction while being guided by the circumferential groove 22, but the height H of the positioning pin 15 and the height of the stopper 30 are set. By adjusting the relationship with I as shown in FIGS. 5 (a) to 5 (c), the predetermined piece 10 (S, M, L) can be moved to the predetermined stopper of the circumferential groove 22. 30 and a predetermined position (1 to
8) (see FIG. 4. In FIG. 4, the symbols a, b, and c attached to the stopper and the pin correspond to the modes of FIGS. 5 (a), (b), and (c), respectively). It shall be.). That is, for example, in FIG. 4, the first to third rows of pieces S, S, and M are distinguished by which circumferential groove 22 guides the pin 15. Further, pieces having the same circumferential groove 22 to be guided, for example, the pieces in the first row, the fourth row, and the seventh row are distinguished by the relationship between H and I as shown in FIG.
Each piece will stop at a predetermined position. As described above, in the present embodiment, the number of the grooves 22, the groove depth G,
Various positioning patterns can be adopted by appropriately changing the height H of the stopper and the height I of the pin. As described above, in the present embodiment, since the positioning of the piece 10 with respect to the sector 20 is performed easily and accurately, the arrangement order of the pieces 10 to be mounted on the sector 20 is erroneously recognized when the mold is assembled after cleaning. Will disappear.

Next, a modified example of the piece 10 is shown in FIG. In the same figure, in this piece 10a, the back surfaces 13a, 13b and 13c are ground, and according to the present example, the portion where the piece and the sector 20 slide when the piece is mounted on the sector 20. It is possible to reduce the number, and it becomes easier to attach / detach the piece. Further, a groove 16 which is an example of a guide is provided on the back surface of the piece 10a. When the mold is released, the rail 40 is guided in the groove 16 and each piece 10a is moved to the rail 40 to connect the beads. In this state, it is convenient that the detached pieces 10a do not come apart. In this case, the cross-sectional shape of the groove 16 is
As shown in FIG. 7, it is preferable that the rail 40 be shaped so as to have an undercut so that the rail 40 does not come out of the groove 16. The guide is not necessarily a groove, but may be a hole. Further, if the rail 40 is made of a soft metal wire, for example, a copper rod, the rail 40 can be removed by blast cleaning the piece 10a as shown in FIG.
By bending the state shown in (a) to the state shown in FIG. 8 (b), the molding surface 11 and the adjacent surface 12 of the piece 10a can be exposed, and the cleaning efficiency can be improved. In addition, as another method, a method of preparing a wire 41 longer than the total length of the pieces 10a and connecting the pieces 10a to each other by the wires 41 can be exemplified (see FIG. 6).

(Embodiment 2) Another embodiment of the tire molding die of the present invention is shown in FIG. FIG. 9A is a perspective view of a segment similar to the segment 5 shown in the first embodiment.
(b) is a perspective view of the piece 10b used for this segment. In the following description, the same members as those described above will be designated by the same reference numerals, and the description thereof will be omitted. Although the mold shown in this embodiment is also the above-mentioned segment type mold, the holder plate 50, 50 is used to hold the piece 10b in the sector 20 from above and below to improve the mounting strength of the piece 10b. . The use of the holder plate 50 as described above is suitable when the pieces 10b are arranged in the upper and lower two stages, and the joining strength of the contact surfaces 19 above and below the piece 10b can be increased. By fitting the holder plate 50 into the stepped portion 11a of the piece 10b, the piece 10b can be pressed in the direction indicated by the arrow D in the figure, and the mounting strength of the piece 10b can be further improved. Further, in the mold of the present embodiment, the loading / unloading direction of the piece 10b is the radial direction shown by the arrow B in the figure. A convex portion 17 having a predetermined shape is provided at a predetermined position on the back surface 13 of the piece 10b, and a concave portion 24 having a predetermined shape is provided at a predetermined position on the holding surface 21 of the sector 20. Also,
The adjacent surface 12 of the piece 10b is processed into a curved surface.

As shown in FIG. 10, in this embodiment, the specific piece 10b is attached to the specific position of the sector 20 by changing the shape and position of the convex portion 17 and the shape and position of the concave portion 24. This is done with certainty. In the present embodiment, unlike the first embodiment, it is not necessary to sequentially arrange the pieces in the circumferential direction, and therefore it is not necessary to change the positioning pattern according to the arrangement order of the pieces. Therefore, it is sufficient to select the uneven shape and the position corresponding to the type of the pattern pitch of the piece,
In FIG. 10, for example, the pieces in the second row and the pieces in the seventh row can be exchanged. Further, in the present embodiment, in the state where the fixing as shown in FIG. 3 is not made,
Since all the pieces 10b in the segment can be attached and detached at the same time, the workability of releasing the mold can be improved. Furthermore, piece 10
By providing a groove on the back surface of b and inserting the rail into this groove, it is possible to prevent the pieces 10b from falling apart during attachment / detachment (see FIG. 6).

(Embodiment 3) FIG. 11 is a perspective view showing another embodiment of the tire molding die of the present invention.
Is a partial perspective view of a segment, and FIG. 11B is a perspective view of a piece 10c used for this segment. The mold shown in this embodiment is also a segment type mold, but the piece 10c
The attachment / detachment direction is the axial direction (vertical direction) indicated by the arrow C in the figure. For the positioning of the piece 10c and the sector 20, the height h and the width x of the vertical groove 18 provided on the back surface 13 of the piece 10c, and the convex portion 25 that is fitted (guided and locked) in the groove 18 are appropriately selected. It is done by selecting.

In the present embodiment, the piece 1 in the segment is in the unfixed state as shown in FIG.
Since all of 0c can be removed at the same time, the workability of releasing the mold can be improved. In addition, by inserting the rail 40 into the groove 16 of the piece 10c, it is possible to prevent the piece 10c from becoming disjointed during attachment / detachment. In addition, according to the present embodiment, the pieces 10c can be simultaneously and instantly detached by lifting both ends of the inserted rail 40, so that the detachability is better than that of the second embodiment. In addition, in the present embodiment, the adjacent surface 12 of the piece 10c is a flat surface, but can be a curved surface, and the piece 10c can be divided into upper and lower stages. When the piece 10c is divided into upper and lower parts, it is preferable to fix the piece 10c using the holder plates 50, 50 as in the second embodiment.

(Embodiment 4) FIG. 12 shows another embodiment of the tire molding die of the present invention. The mold shown in this embodiment is a vertically divided mold shown in FIG. 14 (a), FIG. 12 (a) is a perspective view showing a part of the mold, and FIG. 12 (b) is It is a perspective view showing piece 10d used for this metallic mold. The positioning mechanism of the mold of this embodiment is basically the same as that of the third embodiment. When the adjacent surface 12 of the piece 10d is curved, it is necessary to simultaneously remove and attach the pieces 10d for the entire circumference.
It is preferable to provide a draft on the back surface 13 of 1 and the piece 10d. However, if one of the adjacent surfaces of the pieces is a flat surface and the pieces are removed first, it is not necessary to remove and attach all the pieces at the same time. Further, as shown in FIG. 13, a grinding surface 13a is provided on the piece 10d, and the grinding surface 1
If the pieces 10d are connected to each other by the wire 41 using the wire 3a, the attachment / detachment can be performed more easily. In this case, it is preferable to connect them in units of about 10 pieces.

Next, the material and the like of the piece 10 and the sector 20 will be described. The piece 10 and the sector 20 are made of an iron-based alloy, an aluminum alloy, etc., and are cast, machined,
It can be produced by applying electrical discharge machining or the like alone or in combination. If the coefficient of thermal expansion between the materials of the piece 10 and the sector 20 is significantly different, a gap or the like must be provided in consideration of this in the mold assembly. Therefore, it is preferable to manufacture both of them with the same kind of material, especially the piece. Considering the dents and the like at the corners of the pieces due to the pieces coming into contact with each other during desorption, it is more preferable to use an iron-based alloy having a higher hardness than the aluminum alloy. Further, generally, when cleaning the mold, a blast treatment is performed by spraying a granular material such as glass beads onto the molding surface 11 of the piece 10, but when the piece 10 is made of an aluminum alloy, the hardness is low, Forming surface 11
The long side portion (see FIG. 1) may be plastically deformed outward in the circumferential direction and the radial direction to narrow or block the air venting gap provided between the pieces 10 to reduce the air venting effect. In this case, the corner formed by the long side (the corner corresponding to the long side among the corners formed by the molding surface 11 and the adjacent surface 12 continuous to the molding surface 11) is previously or ex-posted. Moreover, the air venting effect can be maintained or restored by chamfering about 0.1 mm so as not to impair the appearance of the tire and reducing the amount of plastic deformation of the long side portion. From this point of view, it is preferable to use an iron-based alloy having a hardness higher than that of an aluminum alloy as the material of the piece 10, and if the piece 10 is made of an iron-based alloy, the piece 10 will be placed on the sector 20 after the mold is washed. At the time of mounting, it is possible to avoid the trouble of adjusting the air bleeding gap, and the mold can be assembled more quickly.

The present invention has been described above with reference to the preferred embodiments, but the present invention is not limited to these embodiments.
Various modifications are possible within the scope of the present invention. For example, the molds shown in Examples 1 to 3 can be applied to a vertically divided type. Further, in the molds of Examples 1 and 2, the pieces are arranged in upper and lower two stages, but the pieces may be integrally formed in the upper and lower sides.

[0021]

As described above, according to the present invention,
Since the concave and convex portions having selectivity are provided on the back surface of the piece and the holding surface of the holder, it is possible to provide a tire molding die that can be easily and quickly washed and assembled.

[Brief description of drawings]

FIG. 1 is a perspective view partially showing an embodiment of a tire molding die of the present invention.

FIG. 2 is a perspective view of a piece used in the mold of FIG.

FIG. 3 is a perspective view and a partial sectional view showing a fixed state of a piece and a sector.

FIG. 4 is a schematic diagram showing a positioning relationship between a piece and a sector.

FIG. 5 is an explanatory side view showing the relationship between the height of the stopper and the height of the pin.

FIG. 6 is a perspective view showing a modified example of the piece.

FIG. 7 is a partial cross-sectional view showing the shape of a groove.

FIG. 8 is a schematic view showing a state where the pieces are connected in a beaded manner.

FIG. 9 is a partial perspective view showing another embodiment of the tire molding die of the present invention.

FIG. 10 is a schematic diagram showing a positioning relationship between a piece and a sector.

FIG. 11 is a partial perspective view showing another embodiment of the tire molding die of the present invention.

FIG. 12 is a partial cross-sectional view showing another embodiment of the tire molding die of the present invention.

13 is a perspective view showing a modified example of the piece used in the mold of FIG.

FIG. 14 is an exploded perspective view showing an example of a conventional tire molding die.

[Explanation of symbols]

5 segments, 10, 10a, 10b, 10c, 1
0d piece, 13 back, 15 positioning pins, 1
6 groove, 17 convex part, 18 vertical groove, 20 holder sector, 21 holding surface, 22 peripheral groove, 24 concave part,
25 convex parts, 30 stoppers, 40 rails, 4
1 wire

Claims (8)

[Claims] 1. A tire-molding die comprising a plurality of pieces, which are annular as a whole, for imparting a tread pattern to a product tire, and a holder to which these pieces can be mounted adjacently in the circumferential direction. The holder has a convex portion on its back surface, and the holding surface of the holder is provided with a circumferential groove for guiding the convex portion of the piece.The convex portion of any piece is arranged at a predetermined position of the circumferential groove. A tire-molding die, which is in contact with only a stopper provided. 2. The tire molding die according to claim 1, wherein the holder is divided into a plurality of sectors. 3. The tire molding die according to claim 1, wherein a guide is provided on the back surface of the piece, and the pieces are connected by using a wire guided by the guide. 4. A tire-molding die comprising a plurality of generally annular pieces for imparting a tread pattern to a product tire, and a holder to which these pieces can be mounted adjacently in the circumferential direction. The holding surface of the holder that abuts against the back surface has a concave portion or a convex portion, and the concave portion or the convex portion on the rear surface of any of the pieces fits only with the convex portion or the concave portion at a predetermined position on the holding surface of the holder. A mold for tire molding, characterized by the above. 5. The tire molding die according to claim 4, wherein the holder is divided into a plurality of sectors. 6. The tire molding die according to claim 4, wherein the piece is mounted on the holder in a radial direction. 7. The tire molding die according to claim 4, wherein the piece is axially attached to the holder. 8. A tire molding according to claim 6 or 7, characterized in that a guide is provided on the back surface of the piece and each piece is connected by using a wire guided by the guide. Mold.