JP5417493B2 - Mold for tire - Google Patents

Description

  The present invention relates to a mold used in a tire vulcanization process.

  In the tire vulcanization process, a mold is used. A split mold and a two-piece mold can be used for this vulcanization process. In the vulcanization process, a preformed raw cover is put into a mold. The raw cover is heated while being pressurized in a cavity surrounded by the mold and the bladder. The rubber composition of the raw cover flows in the cavity by pressurization and heating. The rubber causes a crosslinking reaction by heating, and a tire is obtained. When air is left between the cavity surface of the mold and the raw cover during pressurization, a bear is formed on the surface of the tire. Bears reduce tire quality. A general mold has a vent hole. Air is discharged through the vent hole.

  The split mold includes arc-shaped tread segments (hereinafter simply referred to as segments). A ring-shaped cavity surface is formed by arranging a large number of segments. The segments are obtained by gravity casting or low pressure casting using a mold. A segment may be obtained by precision casting (so-called die casting) using a metal mold.

  As an example of such a tire mold, a mold disclosed in JP 2009-269245 A is known. The mold segment includes a block. The block has a cavity surface. This cavity surface is formed by direct engraving. The block includes a base and a core integrated in the base. The core is composed of a number of pieces. Each piece has a bolt hole. The large number of pieces are arranged in parallel, and bolts are passed through and fixed to the bolt holes. By doing so, the large number of pieces are integrated to form a core.

  Integration of the core into the base is performed by casting. That is, the core is inserted into the cavity of the mold. Molten metal is poured into the gap. The molten metal is solidified to form a base, and a block including a base and a core cast into the base is formed. This block is cut to form a cavity surface on the surface.

  The integration of the core into the base by casting is a lot of man-hours for the casting itself. Since the core is covered and fixed by the casting, it becomes impossible to disassemble the block after manufacturing. Therefore, special heat treatment is required to remove the dirt accumulated in the gaps between the pieces.

JP 2009-269245 A

  The present invention has been made in order to solve such a problem. The object of the present invention is to provide a tire that can be disassembled after production without requiring a complicated casting process while the core is firmly fixed. The present invention provides a mold for a tire and a method for manufacturing the mold for a tire.

  The tire mold according to the present invention is a tire mold in which a cavity surface is formed on the inner surface, a block having a plurality of parallel plate-like pieces, and a holder having a recess into which the block can be fitted, A fixing member that removably fixes the block fitted in the recess to the recess is provided.

  Such a configuration eliminates the need for a casting process, and the mold can be disassembled after the mold is completed and after its use.

A second slit extending in the axial direction is formed between two adjacent pieces,
The second slit extends from the cavity surface to the clearance on the back surface,
The block is provided with a plurality of units in parallel in the axial direction, between the two units adjacent third slit extending in the circumferential direction is formed.

A second shim sandwiched between two adjacent pieces, and a third shim sandwiched between two adjacent units, wherein the second slit is formed by the second shim, third slits that are formed by the third shim.

A method for manufacturing a tire mold according to the present invention includes:
A step of fixing a plurality of plate-like piece base materials in a parallel state to form a block base material;
Forming a recess for fitting the block base material to the holder base material by cutting;
A step of fitting the block base material into the recess of the holder base material;
A step of forming a segment base material by removably fixing the block base material fitted in the recess to the recess by a fixing member;
A segment forming step of forming a cavity surface by cutting the segment base material; and
A step of connecting a plurality of the segments to form a mold is included.

  In the step of forming the block base material, it is preferable to form a slit by disposing shims between adjacent piece base materials, and to expose the slit on the cavity surface in the segment forming step.

The tire manufacturing method according to the present invention includes:
A process of obtaining a raw cover by preforming;
A step in which the raw cover is put into a mold having a cavity surface formed on the inner surface;
The raw cover includes a step of pressing and heating in the mold,
The mold has a block having a plurality of plate-shaped pieces arranged in parallel, a holder having a recess into which the block can be fitted, and a block fitted in the recess so that the block can be attached to and detached from the recess. It is a mold provided with the fixing member to fix.

  From the viewpoint of suppressing bear by discharging air, it is preferable that a shim is interposed between the plate-like pieces.

  In the mold according to the present invention, the block is firmly held without requiring a casting process, and the mold can be disassembled even after use, so that the holder and the block can be cleaned.

FIG. 1 is a plan view showing a part of a tire mold according to one reference embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a perspective view showing a segment of the mold of FIG. 4A is a plan view showing a block of the segment of FIG. 3, and FIG. 4B is a partially cutaway front view thereof. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. FIG. 7 is a cross-sectional view taken along the line VII-VII of the segment of FIG. 8 is a cross-sectional view taken along line VIII-VIII of the segment of FIG. FIG. 9 is an enlarged cross-sectional view taken along line IX-IX in FIG. FIG. 10 is a perspective view of the segment base material of FIG. 3 before assembly. FIG. 11 is a perspective view after the base material of FIG. 10 is assembled. 12 is a cross-sectional view showing each state before and after cutting the base material of FIG. FIG. 13 is a plan view showing a segment of a mold according to another reference embodiment. 14 is a cross-sectional view taken along line XIV-XIV in FIG. FIG. 15 is a cross-sectional view corresponding to FIG. 14 showing a segment of a mold according to still another reference embodiment of the present invention. FIG. 16 is a perspective view showing a segment of a mold according to an embodiment of the present invention. 17 is a cross-sectional view taken along line XVII-XVII in FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. FIG. 19 is a perspective view showing a block of the segment of FIG. 20 is a perspective view of the segment base material of FIG. 16 before assembly. 21 is a perspective view after the base material of FIG. 20 is assembled.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

FIG. 1 is a plan view showing a part of a tire mold (hereinafter simply referred to as a mold) 1 according to one embodiment of the present invention. FIG. 2 is an enlarged sectional view taken along line II-II in FIG. The mold 1 includes a number of segments 2, a pair of upper and lower side plates 3, and a pair of upper and lower bead rings 4. The planar shape of the segment 2 is substantially arcuate. A number of segments 2 are connected in a ring shape. The number of segments 2 is usually 3 or more and 20 or less. The side plate 3 and the bead ring 4 are substantially ring-shaped. This mold 1 is a so-called “split mold”. In FIG. 2, the symbol R indicates a raw cover.

  FIG. 3 is a perspective view showing the segment 2 of the mold 1 of FIG. In FIG. 3, the arrow X indicates the radial direction, the arrow Y indicates the axial direction, and the arrow Z indicates the circumferential direction. The same applies to other drawings. The segment 2 includes a holder 5 and a block 6. The holder 5 is made of steel or aluminum alloy. The block 6 is attached to the holder 5. A plurality of blocks 6 arranged in parallel in the circumferential direction Z may be attached to the holder 5.

  The block 6 has a cavity surface 7. The cavity surface 7 includes a convex portion 8 and a concave portion 9. The convex portion 8 corresponds to the groove of the tire tread. The recess 9 corresponds to a tread block of the tire. A tread pattern is formed on the tire by the convex portions 8 and the concave portions 9. The shape of the convex part 8 and the recessed part 9 is suitably determined according to a tread pattern. In addition, in FIG. 2, illustration of the convex part 8 and the recessed part 9 is abbreviate | omitted.

  4A is a plan view showing the block 6 of the segment 2 in FIG. 3, and FIG. 4B is a front view thereof. FIG. 5 is an enlarged cross-sectional view along the line VV in FIG. FIG. 6 is an enlarged cross-sectional view taken along the line VI-VI in FIG. The block 6 has a back surface 10, two divided surfaces 11, and upper and lower end surfaces 29 together with the cavity surface 7. The back surface 10 faces the cavity surface 7.

The block 6 has two end pieces 13 and a plurality of intermediate pieces 14 arranged between the end pieces 13. Each piece 13 and 14 is plate-shaped. Each piece 14 is made of an aluminum alloy. All pieces 13 and 14 are juxtaposed in the axial direction Y. Bolt holes 15 are formed in the respective pieces 13 and 14 at positions corresponding to each other. Bolts 16 are inserted into the bolt holes 15. Nuts 17 are screwed to both ends of each bolt 16. A counterbore 18 for accommodating the nut 17 is formed in the bolt hole 15 of the end piece 13. For this reason, neither the bolt 16 nor the nut 17 protrudes from the end surface 29 of the end piece 13. In this reference form, all pieces 13 and 14 are fastened by four bolts 16 and nuts 17.

A fixing pin hole 19 is formed on the end face 29 of the end piece 13 at a position avoiding the bolt hole 15 and the counterbore 18. As will be described later, the pin hole 19 is used to fix the block 6 to the holder 5 by the fixing pin 20 (FIG. 7). In this reference form, three pin holes 19 are formed in each end piece 13. However, the number is not limited.

  As apparent from FIGS. 7 and 8, the holder 5 is formed with a recess 21 into which the block 6 can be closely fitted by cutting. The recess 21 is defined by a bottom surface 22 and inner surfaces of a pair of opposing side walls 23, and has a channel shape with a substantially rectangular cross section. The recess 21 has a shape complementary to the outer shape of the block 6. The bottom surface 22 of the recess 21 covers the back surface 10 of the block 6, and the side wall 23 of the recess 21 covers the upper and lower end surfaces (end surfaces of the end piece 13) 29 of the block 6. The dividing surface 11 of the block 6 is exposed (FIG. 3). The bottom surface 22 of the recess 21 is in contact with the back surface 10 of the block 6 fitted in the recess 21 while forming a slight clearance 30. The inner surface of the side wall 23 of the recess 21 is in contact with the upper and lower end surfaces of the fitted block 6 while forming a slight clearance 30. These clearances 30 can be formed, for example, by forming ridges on the inner surface of the recess 21 and / or the outer surface of the block 6.

  As shown in FIG. 7, a screw hole 24 passes through a portion of the side wall 23 that coincides with the pin hole 19 of the end piece 13. The fixing pin 20 is screwed into the screw hole 24. A male screw is formed on the outer peripheral surface of the fixing pin 20 except for a predetermined length at the tip. A pin portion 25 having a valley diameter of the male screw or an outer diameter smaller than that is formed at a predetermined length portion at the tip of the fixing pin 20. When the fixing pin 20 is screwed into the screw hole 24, the pin portion 25 is engaged with the pin hole 19 of the end piece 13. Thereby, the block 6 is fixed to the recess 21. When the fixing pin 20 is screwed into the screw hole 24, the rear end thereof is submerged in the screw hole 24. An engagement groove 26 is formed at the rear end of the fixing pin 20 for rotating operation by a driver. The block 6 can be taken out from the recess 21 by the fixing pin 20 being loosened or pulled out. As described above, the fixing pin 20 constitutes a fixing member that detachably fixes the block 6 to the recess 21 by the screw hole 24 and the pin hole 19. As shown in FIG. 8, a screw hole 34 for screwing a holding eyebolt or the like and a pin hole 35 for positioning are formed on the back surface of the holder 5. These holes 34 and 35 do not penetrate into the recess 21.

  As shown in FIGS. 5 and 6, a first shim 27 is sandwiched between adjacent pieces 13 and 14 in the block 6. When the nut 17 is tightened, the pieces 13 and 14 clamp the first shim 27. The first shim 27 forms a first slit 28 between adjacent pieces 13 and 14. The first slit 28 extends in the radial direction X and the circumferential direction Z. The first slit 28 extends from the cavity surface 7 to the back surface 10. Accordingly, the first slit 28 communicates with the clearance 30. The first shim 27 is made of a metal such as stainless steel. The first shim 27 has a thin plate shape. As shown in FIG. 9, the planar shape of the first shim 27 is substantially rectangular. The first shim 27 that is rectangular can be easily manufactured.

  FIG. 9 is an enlarged cross-sectional view taken along line IX-IX in FIG. FIG. 9 shows the intermediate piece 14, the bolt 16, and three first shims 27. The first shim 27 is arranged avoiding the bolt hole 15. In other words, the bolt 16 does not penetrate the first shim 27. Since the first shim 27 does not need to have a hole for the bolt 16, the first shim 27 can be easily manufactured. In FIG. 9, the tread pattern protrusions 8 and recesses 9 are not shown.

  The manufacturing method of the segment 2 is outlined with reference to FIGS. First, a base material (referred to as a holder base material) 31 of the holder 5, a base material (referred to as an end piece base material) 32 of the end piece 13, and a base material (referred to as an intermediate piece base material) 33 of the intermediate piece 14. Prepared. As shown in FIG. 10, the holder base material 31 is preferably formed in a rectangular parallelepiped shape from a forged aluminum alloy, and then the recess 21 is formed by cutting. The bottom surface 22 of the recess 21 has a partial cylindrical shape. A pair of side walls 23 facing each other with the bottom surface 22 interposed therebetween are erected. In the side wall 23, the screw hole 24 is formed so as to penetrate the recess 21 from the outside of the side wall 23.

  The piece base materials 32 and 33 are plate-like, and the planar shape thereof is a shape in which one side of the rectangle is formed in an arc shape. The radius of curvature of this arc coincides with the radius of curvature of the bottom surface of the recess 21. Bolt holes 15 are formed in the end piece base material 32 and the intermediate piece base material 33, and counterbore 18 and pin holes 19 are further formed in the end piece base material 32. These 15, 18, and 19 have already been described. As shown in FIG. 10, two end piece base materials 32, an intermediate piece base material 33 disposed between the end piece base materials 32, and a first disposed between the piece base materials 32 and 33. The shim 27 is laminated. Bolts 16 are inserted into the bolt holes 15 and nuts 17 are tightened. Thereby, all the piece base materials 32 and 33 are fastened, and the block base material 36 is comprised. The block base material 36 has a shape in which one surface of a rectangular parallelepiped is a partial columnar shape.

  As shown in FIG. 11, the block base material 36 is fitted into the recess 21 of the holder base material 31. The fixing pin 20 is screwed into the screw hole 24 of the holder base material 31, and the pin portion 25 at the tip of the fixing pin 20 is inserted into the pin hole 19 of the block base material 36. Thereby, the block base material 36 and the holder base material 31 are fixed to form the segment base material 37. In FIG. 11, the illustration of the male screw of the fixing pin 20 is omitted. Both end surfaces of the segment base material 37 are cut so as to be inclined as indicated by a two-dot chain line.

  As shown in FIG. 12, only the hatched portion is deleted by cutting the segment base material 37 to form the segment (white background portion in the figure) 2. The fixing pin 20 is screwed into the screw hole 24 of the holder base material 31 and the rear end thereof has a length that is not located in the excision range indicated by hatching.

  A large number of piece base materials 32 and 33 and a large number of first shims 27 are alternately stacked (the first shim 27 is not shown in FIG. 12). The piece base materials 32 and 33 and the first shim 27 are integrated by a bolt 16 and a nut 17. The cavity surface 7 provided with the concavo-convex pattern is formed by the cutting process. In this method, the concavo-convex pattern is directly carved. A typical cutting process is cutting with a tool. Cutting may be performed by high energy density processing. Specific examples of the high energy density machining include electrolytic machining, electric discharge machining, wire cut electric discharge machining, laser machining, and electron beam machining. Since the concavo-convex pattern is directly carved, the degree of freedom of the shape of the concavo-convex pattern is high. This uneven pattern has high dimensional accuracy. The segment 2 is obtained by the above cutting process.

  In the tire manufacturing method using this mold 1, a raw cover is obtained by preforming. This raw cover is put into the mold 1 with the mold 1 open and the bladder contracted. At this stage, the rubber composition of the raw cover is in an uncrosslinked state. The mold 1 is tightened and the bladder expands. The raw cover is pressed against the cavity surface 7 of the mold 1 by a bladder and pressurized. The raw cover R in this state is shown in FIG. At the same time, the raw cover is heated. The rubber composition flows by pressurization and heating. The rubber causes a crosslinking reaction by heating, and a tire is obtained. The process in which the raw cover is pressurized and heated is referred to as a vulcanization process.

  As described above, since the first slit 28 is exposed to the cavity surface 7 (FIGS. 5 to 7), the air between the raw cover and the cavity surface 7 moves through the first slit 28 in the vulcanization process. The air reaches the dividing surface 11 and is discharged. Even air in a region away from the dividing surface 11 can move to the dividing surface 11 through the first slit 28. Air can also be discharged through the first slit 28 and the bolt hole 15. Bear is prevented by the movement and discharge of air. In the mold 1, air can be sufficiently discharged even if a vent hole is not provided. A tire without spew is obtained by the mold 1 having no vent hole. This tire is excellent in appearance and initial grip performance. A small number of vent holes may be provided together with the first slit 28.

  Another segment 41 is shown in FIGS. The segment 41 differs from the segment 2 shown in FIG. 3 in that the segment 41 is formed with a channel 42 for air circulation that penetrates both side walls 23 of the holder 5 and all the pieces 13 and 14. Is a point. Furthermore, a groove-like vent line 45 communicating with the channel 42 is formed on the upper surface 43 and the lower surface 44 of the segment 41 (the outer surface of the side wall 23). Since the other constituent members of the segment 41 are substantially the same as the constituent members of the segment 2 in FIG. 3, the same reference numerals as those of the constituent members of the segment 2 in FIG. The description is omitted.

  The channel 42 extends in the axial direction Y of the segment 41. The channel 42 is separated from the bolt hole 15 and the pin hole 19. The channel 42 opens on each of the upper surface 43 and the lower surface 44 of the segment 41. The channel 42 passes through the segment 41 but does not pass through the first shim 27. That is, the channel 42 communicates with the first slit 28. As described above, since the first slit 28 communicates with the clearance 30, the channel 42 also communicates with the clearance 30. The channel 42 communicates the first slit 28 and the clearance 30 with the outside. Both the channel 42 and the vent line 45 can circulate air. The vent line 45 communicates with the opening of the channel 42. As shown in FIG. 13, each vent line 45 extends radially outward X from the opening of the channel 42. Therefore, even if the upper and lower surfaces 43 and 44 of the segment 41 are covered with members constituting a sector shoe (not shown), air can be discharged. The mold using the segment 41 is excellent in air discharge performance, and bears can be effectively prevented.

  As shown in FIG. 13, four channels 42 are provided in one segment 41. The number of channels 42 provided in one segment 41 is determined as appropriate. These channels 42 are arranged on the same circumference at intervals. Note that the plurality of channels 42 provided in the segment 41 may be concentrically arranged in a plurality of rows. These channels 42 may be randomly arranged.

  FIG. 15 shows still another segment 51. This segment 51 also includes a channel 52 and a vent line 45. The segment 51 is different from the segment 41 shown in FIG. 13 in that the channel 52 in the segment 51 has a bottom and is a non-through hole. The constituent members other than the channel 52 of the segment 51 are substantially the same as the constituent members of the segment 41 in FIG. 13, so that these constituent members have the same reference numerals as the constituent members of the segment 41 in FIG. 13. The description is omitted.

  In the segment 51, a channel 52 opened on the upper surface 53 of the segment 51 and a channel 52 opened on the lower surface 54 are formed. Each channel 52 extends in the axial direction Y of the segment 51. The channels 52 are arranged at intervals on the same circumference. Note that the plurality of channels 52 provided in the segment 51 may be concentrically arranged in a plurality of rows. These channels 52 may be arranged randomly.

  The channel 52 reaches the clearance 30 and communicates the clearance 30 with the outside. A part of the air moving through the clearance 30 is discharged to the outside through the channel 52. The air moving through the first slit 28 is also discharged outside through the clearance 30 and the channel 52. This channel 52 can contribute to the discharge of air. The mold using the segment 51 is excellent in air discharge performance, and bear can be effectively prevented. The channel 52 may be configured to directly communicate with the first slit 28 and the outside by adjusting the length of the channel 52.

  Since the manufacturing method of this segment 41 is substantially the same as the manufacturing method of the segment 1 described with reference to FIGS. 10-12, description is abbreviate | omitted.

FIG. 16 shows a segment 61 according to an embodiment of the present invention . This segment 61 also includes a holder 62 and a block 63. In the block 63, the end piece 64 and the intermediate piece 65 are arranged in parallel in the circumferential direction Z, not in the axial direction Y. The block 63 has a rectangular parallelepiped outer shape. The block 63 is fitted in the recess 81 of the holder 62. The block 63 includes two units 66 arranged in parallel in the axial direction Y. The number of units is not limited to two and may be three or more.

  FIG. 17 is a cross-sectional view taken along line XVII-XVII in FIG. In FIG. 17, the tread pattern protrusions 8 and recesses 9 are not shown. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. FIG. 19 is a perspective view showing the block 64 in the segment 61 of FIG. As shown in FIGS. 17 and 19, all pieces 64 and 65 are fastened by bolts 67 and nuts 68 for each unit 66. A counterbore 69 for accommodating the nut 68 is formed on the end face of the end piece 64. Neither bolt 67 nor nut 68 protrudes from the end face of end piece 64.

  As shown in FIG. 17, a second shim 70 is sandwiched between the pieces 65. When the nut 68 is tightened, the pieces 64 and 65 clamp the second shim 70. The second shim 70 is arranged avoiding the bolt 67. In other words, the bolt 67 does not penetrate the second shim 70. The second shim 70 has a configuration equivalent to that of the first shim 27 shown in FIGS. 5 and 6. The second shim 70 forms a second slit 71 between the adjacent pieces 64 and 65. The second slit 71 extends in the radial direction X and the axial direction Y. The second slit 71 extends from the cavity surface 72 of the block 63 to the back surface 73.

  As shown in FIGS. 18 and 19, the two units 66 are fastened by a bolt 74 and nuts (not shown) screwed to both ends of the bolt 74. Specifically, a bolt hole 76 is formed in the axial direction Y in the end piece 64 of each unit 66. A counterbore 77 for accommodating a nut is formed on the side end surface of the end piece 64 of each unit 66. Neither the bolt 74 nor the nut protrudes from the side end surface of the end piece 64.

  As shown in FIG. 18, a third shim 78 is sandwiched between the two units 66. The third shim 78 is arranged avoiding the bolt 74. In other words, the bolt 74 does not penetrate the third shim 78. A third slit 79 is formed between the two units 66 by the third shim 78. The third slit 79 extends in the radial direction X and the circumferential direction Z. The third slit 79 extends from the cavity surface 72 of the block 63 to the back surface 73.

  As shown in FIGS. 18 and 19, pin holes 80 for fixing in the axial direction Y are formed on the side end surfaces of the plurality of intermediate pieces 65 of each unit 66. The pin hole 80 is used to fix the block 63 to the holder 62 with a fixing pin, as will be described later. In this embodiment, pin holes 80 are formed in three intermediate pieces 65 spaced from each other for each unit 66. Of course, the number of intermediate pieces 65 in which the pin holes 80 are formed is not limited to three. Two or four or more may be sufficient.

  As shown in FIGS. 16 and 18, the block 63 is closely fitted in the recess 81 of the holder 62 and is fixed by a fixing pin 20 (not shown in FIG. 16). The recess 81 is formed by cutting. The recess 81 is defined by a bottom surface 82 and inner surfaces of a pair of opposing side walls 83, and has a channel shape with a substantially rectangular cross section. The recess 81 has a shape complementary to the outer shape of the block 63. The bottom surface 82 of the recess 81 covers the back surface 73 of the block 63, and the side wall 83 of the recess 81 covers the upper and lower end surfaces (side end surfaces of all pieces 64, 65) 84 of the block 63. The dividing surface 85 of the block 63 is exposed (FIG. 16). The bottom surface 82 of the recess 81 is in contact with the back surface 73 of the block 63 fitted in the recess 81 while forming a slight clearance 86. The inner surface of the side wall 83 of the recess 81 is in contact with the upper and lower end surfaces 84 of the fitted block 63 while forming a slight clearance 86. These clearances 86 can be formed, for example, by forming ridges on the inner surface of the recess 81 and / or the outer surface of the block 63.

  As shown in FIG. 18, a screw hole 87 passes through a portion of the side wall 83 of the holder 62 that coincides with the pin hole 80 of the three intermediate pieces 65. The fixing pin 20 is screwed into the screw hole 87. Since this fixing pin 20 has the same configuration as that of the fixing pin 20 shown in FIG. 7, the description thereof is omitted here. When the fixing pin 20 is screwed into the screw hole 87 of the holder 62, the pin portion 25 at the tip is engaged with the pin hole 80 of the intermediate piece 65. Thereby, the block 63 is fixed to the recess 81. When the fixing pin 20 is screwed into the screw hole 87, the rear end thereof is submerged in the screw hole 87. The block 63 can be taken out from the recess 81 by loosening or pulling out the fixing pin.

  The manufacturing method of the segment 61 will be outlined with reference to FIGS. First, a base material (referred to as a holder base material) 91 of the holder 62, a base material (referred to as an end piece base material) 92 of the end piece 64, and a base material (referred to as an intermediate piece base material) 93 of the intermediate piece 65 are provided. Prepared. As shown in FIG. 20, the holder base material 91 is formed in a rectangular parallelepiped shape from a forged aluminum alloy, and then a recess 81 is formed by cutting. A pair of side walls 83 facing each other with the bottom surface 82 interposed therebetween are erected. The side wall 83 is formed with the screw hole 87 so as to penetrate the recess 81 from the outside of the side wall 83. A screw hole 94 for screwing a holding eyebolt or the like and a pin hole 95 for positioning are formed on the back surface of the holder 62 (FIGS. 17 and 18). These holes 94 and 95 do not penetrate into the recess 81.

  The piece base materials 92 and 93 are plate-shaped. Bolt holes, counterbore 69 and pin hole 80 are formed in piece base materials 92 and 93, which have already been described. As shown in FIG. 20, two end piece base materials 92, a plurality of intermediate piece base materials 93 disposed between the end piece base materials 92, and the piece base materials 92, 93 are disposed. The second shim 70 is laminated. The bolt 67 is inserted into the bolt hole, and the nut 68 is tightened. Thereby, all the piece base materials 92 and 93 are fastened and the base material of each unit is comprised. Two unit base materials and a third shim 78 disposed between the unit base materials are laminated. Bolts 74 are inserted into the bolt holes 76 of each unit base material, and nuts are tightened. Thereby, two unit base materials are integrated and the block base material 96 is comprised. The block base material 96 has a rectangular parallelepiped shape.

  As shown in FIG. 21, the block base material 96 is fitted into the recess 81 of the holder base material 91. The fixing pin 20 is screwed into the screw hole 87 of the holder base material 91, and the pin portion 25 of the fixing pin 20 is inserted into the pin hole 80 of the block base material 96. Thereby, the block base material 96 and the holder base material 91 are fixed to form the segment base material 97. Both end surfaces of the segment base material 97 are cut so as to be inclined as indicated by a two-dot chain line. With respect to this segment base material 97, the cavity surface and the like are processed by further cutting, and the segment 61 shown in FIG. 16 is completed.

  An uneven pattern may not be formed on the cavity surface 7. A slick tire and a plain tire can be obtained by the mold 1 having no uneven pattern. Spew is also suppressed in this slick tire and plain tire. The surface of the plain tire is cut to form an uneven pattern. Since there is little spew, it is easy to cut this plain tire.

  When the mold 1 is used repeatedly, deposits adhere to the cavity surface 7. This deposit impairs the tire quality. The deposit needs to be removed. For removal, after the fixing pin 20 has been loosened or extracted, the blocks 6, 63 are removed from the recesses 21, 81 of the holders 5, 62. Next, the bolts 16 are extracted from the block 6 and disassembled into pieces 13 and 14. In the case of the block 63 composed of a plurality of units 66, first, the bolts 74 are extracted from the block 63, thereby being disassembled into a plurality of units 66. Next, the bolt 67 is removed from each unit 66 and disassembled into pieces 64 and 65. After each part is cleaned, the segments 2, 41, 51, 61 are assembled in the reverse procedure.

In the embodiment and the reference embodiment described above, each slit 28, 71, 79 is formed by interposing shims 27, 70, 78 between pieces 13, 14, 64, 65 or between units 66. ing. However, it is not limited to such a configuration. For example, the slits can also be formed by forming protrusions on the outer surfaces of the pieces 13, 14, 64, 65 and the outer surface of the unit 66.

  The mold according to the present invention is suitable for manufacturing various tires.

1 ... Mold (for tire) 2, 41,
51, 61 ... Segment 5, 62 ... Holder 6, 63 ... Block 7, 72 ... Cavity surface 10, 73 ... Back surface 11, 85 ... Dividing surface 13, 64 ... End piece 14, 65 ... Intermediate piece 16, 67 ... (for piece fastening) Bolt 17, 68 ... (for piece fastening) Nut 20 ... Fixing pin 21, 81 ... Recess 27 ... 1st shim 28 ... 1st slit 30, 86 ... Clearance 31, 91 ... Holder base material 32, 92 ... End piece base material 33, 93 ... Intermediate piece base material 36, 96 ... Block base material 37, 97 ... Segment base material 42, 52 ... Channel 45 ... Vent line 66 ... Unit 70 ... Second shim 71 ... Second slit 74 ... (for unit fastening) Ruto 78 ... Third shim 79 ... Third slit

Claims (8)

A tire mold having a cavity surface formed on the inner surface,
A block having a plurality of plate-like pieces arranged in parallel;
A holder having a recess into which the block can be fitted;
A fixing member that removably fixes the block fitted in the recess to the recess;
A clearance is formed between the block and the holder,
A second slit extending in the axial direction is formed between two adjacent pieces,
The second slit extends from the cavity surface to the clearance on the back surface,
The block includes a plurality of units arranged in the axial direction,
All pieces are fastened for each unit,
A tire mold in which a third slit extending in the circumferential direction is formed between two adjacent units.   The fixing member is engaged with the pin hole formed in the end surface of the unit, the screw hole formed in the portion corresponding to the pin hole in the holder, and the tip is engaged with the pin hole by being screwed into the screw hole. The tire mold according to claim 1, further comprising a fixing pin that can be combined. The unit has a pair of end pieces and a plurality of intermediate pieces stacked between the end pieces, and the end pieces and the intermediate piece are fastened together,
The tire mold according to claim 1 or 2, wherein the plurality of units are integrally fastened by connecting the end pieces facing each other. A second shim sandwiched between two adjacent pieces and a third shim sandwiched between two adjacent units;
The tire mold according to any one of claims 1 to 3, wherein the second slit is formed by the second shim, and the third slit is formed by the third shim. A step of forming a block base material by arranging a plurality of plate-shaped piece base materials in parallel;
Forming a recess for fitting the block base material to the holder base material by cutting;
Fitting the block base material into the recess of the holder base material so that a clearance is formed between the block base material and the holder base material ;
A step of forming a segment base material by removably fixing the block base material fitted in the recess to the recess by a fixing member;
A segment forming step of forming a cavity surface by cutting the segment base material; and
A mold forming step of connecting a plurality of the segments,
In the step of forming the block base material, a second slit extending in the axial direction is formed between two adjacent piece base materials , and the block base material is composed of a plurality of units arranged in parallel in the axial direction. The whole piece base material is fastened for each unit, and a third slit extending in the circumferential direction is formed between two adjacent units.
A method for manufacturing a tire mold, wherein the second slit extends from the cavity surface to the clearance on the back surface. In the step of forming the block base material, a slit is formed by arranging shims between adjacent piece base materials,
The method for manufacturing a tire mold according to claim 5, wherein, in the segment forming step, the slit is exposed on the cavity surface. A process of obtaining a raw cover by preforming;
A step in which the raw cover is put into a mold having a cavity surface formed on the inner surface;
The raw cover includes a step of pressing and heating in the mold,
The mold has a block having a plurality of plate-shaped pieces arranged in parallel, a holder having a recess into which the block can be fitted, and a block fitted in the recess so that the block can be attached to and detached from the recess. A mold having a fixing member to be fixed;
A clearance is formed between the block and the holder,
A second slit extending in the axial direction is formed between two adjacent pieces,
The second slit extends from the cavity surface to the clearance on the back surface,
The block includes a plurality of units arranged in the axial direction,
All pieces are fastened for each unit,
A tire manufacturing method in which a third slit extending in the circumferential direction is formed between two adjacent units.   The tire manufacturing method according to claim 7, wherein a shim is interposed between the plate-like pieces.

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