JP4295642B2 - Manufacturing method of laminated mold - Google Patents

Description

  The present invention relates to a tire vulcanization mold and a method for producing the same, and more particularly to a method for producing a laminated mold formed by laminating a plurality of plates.

Conventionally, when a tire is molded, a plurality of segments 53 each having a crown part mold 51 having a cross-sectional shape of a tire crown part attached to a holder 52 as shown in FIGS. 5 (a) and 5 (b) are annularly formed. Using the connected vulcanization mold 50, pressure is applied to the inside of the molded green tire so that the outer surface of the green tire is pressed against the heated inner wall of the vulcanization mold 50, and the raw rubber is heated and pressurized. A method of vulcanization is performed.
The crown part mold 51 is usually realized by casting. However, such a casting mold not only takes time to manufacture the mold but also has a high material cost. Therefore, in recent years, for the purpose of low cost and short delivery time. In place of the crown part mold 51, which is a casting mold, a segment 63 in which a crown part mold 61 made of a laminated thin plate formed by laminating thin plates 61a as shown in FIG. A multi-layered mold in which a plurality of tread pattern forming portions are arranged by arranging a plurality of the molds is used.
The thin plate 61a is generally processed by laser processing using 2DCAM from the viewpoint of automation and speed-up. Then, a crown part mold 61 in which these thin plates 61a are laminated is attached to a holder 62 to constitute a segment 63 in which the laminated thin plate is a crown part mold. By the way, since the thin plate 61a is a rectangular thin plate in which both end portions are cut by irradiating a laser beam at right angles to the thin plate material, a step corresponding to the thickness of the rectangular thin plate 61a is formed on the tire tread surface. As a result, not only the appearance of the vulcanized tire deteriorates, but the performance is also lower than that of the tire vulcanized using the current casting mold. . In addition, there are concerns that durability and the like deteriorate when the tire tread has a large number of acute angle portions. Therefore, a method of smoothly processing the stepped portion by milling using a tool such as an end mill or electrode processing using a discharge electrode is performed.

However, when using the processing method as described above when processing the stepped portion of the laminated thin plate, processing burrs and burrs are likely to occur, and this processing burrs and burrs block the gaps between the thin plates. There was a problem that air could not be removed from between the thin plates.
Moreover, since the said processing method requires many processing time, it is disadvantageous with respect to the short delivery date which is the merit of a laminated mold.

  The present invention has been made in view of the conventional problems, and an object of the present invention is to provide a method capable of processing the shape of the tire tread surface side of the laminated mold into a state close to the original tire profile in a short time. And

According to a first aspect of the present gun is a plurality of thin plates, after laminating by processing the state which attached the excess thickness than shape corresponding the side in contact with the tire tread to the shape of the tire crown portion, the excess In the manufacturing method of a laminated mold in which meat is removed by blast grinding , after laminating the thin plate with a shim sandwiched between the thin plates, the laminated thin plate is subjected to blast grinding, and then the shim material is removed. it is characterized in that it has to be.
The invention according to claim 2 is characterized in that, in the method for producing a laminated mold according to claim 1, the laminated thin plate is subjected to blast grinding using a fine-grained projection material made of a ceramic material. Is.
According to a third aspect of the present invention, in the method for producing a laminated mold according to the second aspect, the particle size of the projection material is 80 to 200 μm.

  Further, the invention according to claim 4 is the method for producing a laminated mold according to any one of claims 1 to 3, wherein the projection material is made in accordance with the size of the step between the laminated thin plates. Blast grinding is performed while changing any one or more of the injection pressure, the injection distance, the projection time, and the projection direction.

According to a fifth aspect of the present invention, in the method for manufacturing a multilayer mold according to any one of the first to fourth aspects, after the blast grinding process, the multilayer is once disassembled to remove burrs or burrs generated on the thin plate. After the removal, the thin plate is laminated again to build up a laminated mold .

According to the present invention, each thin plate constituting the laminated sheet of the tire vulcanization mold is laminated by processing the side in contact with the tire tread so that a surplus is attached to the shape corresponding to the shape of the tire crown portion. after, in the manufacturing method of a multilayer mold is removed by blanking last grinding the excess meat, after laminating the thin plate sandwich the shim between the thin plate, blast grinding a laminate plate which is the laminated, thereafter, Since the shim material is removed , the tire contour can be processed into a state close to the original tire profile in a short time. In addition, since the step portion can be reduced by sandwiching the shim material, the boundary portion of the thin plate is ground more smoothly and the shim material covers the gap between the thin plates. Intrusion of ground thin plate fragments can be prevented.
At this time, if the projection conditions such as the injection pressure, the projection distance, the projection time, or the projection direction of the projection material are changed according to the shape of the tire tread, and the blast grinding is performed while controlling the step grinding amount, The side in contact with the tire tread surface can be made closer to the shape corresponding to the shape of the tire crown portion.
In addition, once the stack is disassembled to remove protrusions such as burrs and burrs generated on the thin plate, and then the thin plate is stacked again, the air is more reliably vented from the gap between the thin plates. it is possible.

Hereinafter, the best mode of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a method for processing a laminated sheet used in a laminated plate type tire vulcanization mold (laminated mold) according to this best. In this example, blast grinding is performed for each laminated sheet in each segment. I do. In the figure, 11 is a laminated thin plate formed by laminating a plurality of thin plates 12, and 20 is a projection material that pumps a projection material 22 accommodated in a projection material supply means 21 by mixing it with compressed air fed from a compressor 23. The supply device 30 includes a rotation / movement means 32 provided on a base 31 and an injection nozzle 34 mounted on a nozzle holding means 33 attached to the rotation / movement means 32, and the projection material supply device described above. 20 is a projection material injection device for injecting the projection material 22 pumped from 20 through the injection nozzle 34 and blast grinding the tire tread surface side of the laminated thin plate 11, and 40 controls the projection material injection device 20 to perform the injection. While controlling the injection pressure and the projection time of the projection material 22 from the nozzle 34, the rotation / movement means 32 is driven to control the position of the injection nozzle 34, and the projection of the projection material 22 is controlled. A control device for controlling the distance and projection direction. The laminated mold is produced by assembling the segment 10 by assembling the laminated thin plate 11 whose side contacting the tire tread surface is blast-polished to the holder 13 and connecting the plurality of segments 10 in a ring shape.
In this example, ceramic particles such as alumina and silicon carbide are used as the projection material 22. As the size of the particles, it is desirable to use a particle having a particle size of about 80 to 200 μm, which is selected with a sieve of # 80 to # 120. That is, when the particle diameter exceeds 200 μm, the grinding efficiency is improved, but surface roughness occurs, which adversely affects the surface condition of the tire. On the other hand, when the particle diameter is less than 80 μm, the grinding efficiency is lowered, so that it is difficult to perform the blast polishing process in a short time.

Next, a method for manufacturing the segment 10 will be described.
First, as shown in FIG. 2 (a), each thin plate 12 is in a state where the side in contact with the tire tread surface has a surplus from the shape (tire profile) of the tire crown as shown by the line L in FIG. After the processed and laminated laminated thin plate 11 is attached to the jig 41, the projection material 22 is projected from the injection nozzle 34 onto the laminated thin plate 11 to remove the surplus as shown in FIG. Thus, as shown in FIG. 2B, the profile of the surface 12S in contact with the tire tread is processed into substantially the same shape as the original tire profile, which is substantially close to the line L. As described above, the laminated thin plate 11 may be directly attached to the holder 13 for blast grinding without using the jig 41.
Incidentally, since the side of the laminated thin plate 11 that contacts the tire tread is a free-form surface, the size of the step amount between the thin plates 12 and 12 of the laminated thin plate 11 is not constant. Therefore, in this example, the control device 40 controls the projection direction of the projection material 22 from the ejection nozzle 34 according to the size of the stepped portion, and the ejection pressure or projection time of the projection material 22 or The projection material 22 is projected onto the laminated thin plate 11 while controlling the projection distance. For example, the projection direction of the projection material 22 is inclined so as to be substantially perpendicular to the line L, and the projection time is increased in a portion with a large step such as a portion corresponding to the tire shoulder portion of the segment 10 to increase the grinding amount. On the contrary, the profile of the surface 12S in contact with the tire tread is almost equal to the line L by controlling the projection time to be short and reducing the grinding amount at a small step near the center tread of the tire. Process to a close shape. Note that the amount of grinding can be increased by increasing the injection pressure or decreasing the projection distance. Further, the amount of grinding may be controlled by combining the projection time, the injection pressure, and the projection distance, or by using all of these parameters.

In this example, as described above, since the projection material 22 made of ceramic particles such as alumina and silicon carbide having a particle diameter of about 80 to 200 μm is used, it is compared with conventional machining such as milling. As a result, there are few processing burrs and burrs. In addition, even if processing burrs or burrs are generated, they adhere in a porous state, so that the gap between the thin plates 12 and 12 is not blocked by processing burrs or burrs, etc. Although it can be discharged, in order to remove air from between the thin plates 12 and 12 more reliably, after the blast polishing, the laminate is once disassembled to remove the processing burrs and burrs generated on the thin plate 12. However, after that, it is desirable to laminate the thin plate 12 again. In this way, by removing the burrs and burrs generated by blast grinding of the thin plate 12 and then laminating, the gap between the thin plates 12 and 12 can be reliably opened to the side in contact with the raw tire. Therefore, the air can be vented from between the thin plates 12 and 12 more reliably.
Note that even when removing the above-described processing burrs, burrs, etc., it is not always necessary to perform all of the thin plates 12, and the thin plates 12 where air stagnation easily occurs or the thin plates 12 where the grinding amount per unit time is large. It is enough to do only about.

  Thus, according to this best mode, when manufacturing the laminated mold, the side contacting the tire tread surface of the thin plate 12 constituting the laminated thin plate 11 is provided with a surplus than the shape corresponding to the shape of the tire crown portion. After being processed into a stacked state and laminated, the projecting material 22 made of ceramic particles pumped from the projecting material supply device 20 from the spray nozzle 34 of the projecting material ejecting device 30 is projected onto the laminated thin plate 11, and According to the size of the stepped portion between the thin plates 12, 12, the excess material is removed while controlling the projection direction, the injection pressure, the projection time, or the projection distance of the projection material 22. The profile of the surface of the thin plate 11 in contact with the tire tread surface can be processed into substantially the same shape as the original tire profile. Further, after the blast polishing, once the lamination is disassembled to remove the processing burrs and burrs generated on the thin plate 12, and then the thin plate 12 is laminated again, the air is removed from between the thin plates 12 and 12. Can be performed more reliably.

In the best mode, the thin plate 12 is laminated again after removing the processing burrs, burrs and the like of the thin plate 12 in order to perform air venting more reliably, but as shown in FIG. By using a spray 14 or the like in the valleys of the thin plates 12 and 12, masking 15 with releasable vinyl chloride or the like, and then performing blast grinding, processing burrs that are likely to occur at the boundary between the thin plates 12 and 12 While it is possible to suppress burrs and prevent the projection material 22 and the fragments of the ground thin plate 12 from entering the gap between the thin plates 12 and 12, air can be removed with certainty. Moreover, since the boundary part with the thin plates 12 and 12 is more smoothly ground by the masking 15, the processing accuracy can be further improved. The masking 15 is removed after blast grinding.
Further, in place of the masking 15, as shown in FIG. 4, the same effect can be obtained by laminating the shim material 16 between the thin plates 12 and 12, and then blast grinding. That is, since the shim material 16 reduces the stepped portion and covers the opening between the thin plates 12 and 12, the boundary portion between the thin plates 12 and 12 is more smoothly ground, and the projection material 22 into the gap is used. Further, it is possible to prevent the fragments of the thin plate 12 that has been ground from entering. The shim 16 is also removed after blast grinding.

A tire vulcanization mold (lamination) for a tire for a passenger car having a tire size of 265 / 35R18, using a laminated sheet obtained by processing a metal sheet having a thickness of 0.5 mm by laser cutting and laminating these sheets. Mold). The blast grinding process was performed for each segment.
Further, alumina having a particle size of # 100 was used as the projecting material, and this was projected onto the laminated thin plate at a spray pressure of 0.5 MPa from a position about 100 mm away from the surface of the laminated thin plate. At this time, the grinding time was increased at a portion with a large step such as a tire shoulder portion and decreased at a portion having a relatively small step such as a tire center portion. Specifically, the grinding time was changed by moving the injection nozzle in the tire circumferential direction with a pendulum movement having a period of 15 to 30 seconds and increasing or decreasing the number of reciprocations of the nozzle. As a result, a step amount of 0.5 mm or more can be processed smoothly to 0.01 mm or less, a target shape can be obtained, and a tire can be actually manufactured by using a laminated mold produced using a laminated thin plate. As a result of vulcanization, it was confirmed that a tire with no generation of bares could be obtained, and that the air was surely removed.
Also, after decomposing the laminated thin plate once, deburring the thin plate at the location where the air pools, and using a laminated mold that was assembled again, and actually vulcanizing the tire, further generation of bears and the like It was confirmed that it can be suppressed.

  As described above, according to the present invention, the shape of the laminated thin film on the side in contact with the tire surface can be processed to a state close to the original tire profile in a short time, so that the processing time of the laminated mold is greatly shortened. be able to. Therefore, it is possible to easily realize low cost and short delivery time of the laminated mold.

It is a schematic diagram which shows the blast grinding method of the lamination thin plate used for the lamination mold which concerns on the best form of this invention. It is a figure which shows the state before and behind the blast grinding process of a laminated thin plate. It is a figure which shows the other example of the blast grinding method by this invention. It is a figure which shows the other example of the blast grinding method by this invention. It is a figure which shows the outline | summary of the conventional vulcanization die. It is a figure which shows the outline | summary of the conventional laminated mold.

Explanation of symbols

10 segments, 11 laminated sheets, 12 sheets, 13 holders,
20 Projection material supply device, 21 Projection material supply means, 22 Projection material, 23 Compressor,
30 projectile injection device, 31 base, 32 rotation / movement means, 33 nozzle holding means,
34 injection nozzle, 40 control device, 41 jig.

Claims (5)

Manufacturing a laminated mold in which a plurality of thin plates are processed and laminated with a surplus on the side in contact with the tire tread than the shape corresponding to the shape of the tire crown, and then the surplus is removed by blast grinding. In the method, a laminate mold characterized in that a shim material is sandwiched between the thin plates, the thin plates are laminated, the laminated thin plates are subjected to blast grinding, and then the shim material is removed . Production method.   The method for producing a laminated mold according to claim 1, wherein the laminated thin plate is subjected to blast grinding using a fine projection material made of a ceramic material.   The method for producing a laminated mold according to claim 2, wherein the particle size of the projection material is 80 to 200 μm.   According to the size of the step between the laminated thin plates, blast grinding is performed while changing any one or more of the injection pressure, the injection distance, the projection time, and the projection direction of the projection material. The method for producing a laminated mold according to any one of claims 1 to 3. After the blast grinding process, the laminate is once disassembled to remove burrs or burrs generated on the thin plate, and then the thin plate is laminated again to assemble a laminated mold. Item 5. A method for producing a multilayer mold according to any one of Items 4 to 5 .

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