CN113977817A

CN113977817A - Die set

Info

Publication number: CN113977817A
Application number: CN202110736447.5A
Authority: CN
Inventors: 新川耕司; 山田吉博
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2020-07-27
Filing date: 2021-06-30
Publication date: 2022-01-28
Also published as: JP7468222B2; JP2022023379A

Abstract

Provided is a mold which can suppress positional deviation in the circumferential direction. The mold (2) comprises: a plurality of sectors (8) which shape the tread of the tyre; a first side plate (10) for molding one of the outer surfaces of a pair of sidewalls of a tire; a first engaging piece (14) fixed to the sector (8); and a second engaging piece (16) that is fixed to the first side plate (10), has a hardness (H2) that is less than the hardness (H1) of the first engaging piece (14), and can engage with the first engaging piece (14).

Description

Die set

Technical Field

The present invention relates to a tire mold.

Background

In a tire manufacturing method, a green tire is put into a tire mold, and the green tire is pressurized and heated to obtain a tire from the green tire. As one of such molds, there is a mold in which: the mold has sectors for molding the tread and a pair of side plates for molding the outer surfaces of the sidewalls, respectively.

In this mold, the segment and the side plate may be displaced in the circumferential direction. This circumferential positional deviation causes positional deviation between the tread and the outer surface of the sidewall of the tire. In particular, in a tire having a pattern of grooves or blocks or the like across the outer surfaces of the tread and sidewalls, the appearance thereof is impaired.

Patent document 1 discloses a mold in which an engaging pin protruding from a sector is engaged with a groove of a side plate, thereby positioning the sector and the side plate in the circumferential direction. In this mold, the occurrence of positional displacement of the sector and the side plate in the circumferential direction is suppressed.

Patent document 1: japanese patent laid-open publication No. 2007-269005

In this mold, when the sector and the side plate are positionally displaced, a large force acts on the engaging pin. The large external force may deform the engagement pin to break it. Further, the fan-shaped piece from which the engaging pin protrudes may be deformed by the large external force. Such deformation may cause the sector and the side plate to be displaced in the circumferential direction.

Disclosure of Invention

The invention aims to provide a die capable of inhibiting circumferential position deviation.

The mold of the present invention comprises: a plurality of sectors that shape the tread of the tire; a first side plate for molding one of outer surfaces of a pair of sidewalls of the tire; a first engaging piece fixed to any of the fan-shaped pieces; and a second engaging piece that is fixed to the first side plate, has a hardness H2 that is lower than the hardness H1 of the first engaging piece, and is engageable with the first engaging piece.

Preferably, the hardness of the sector to which the first engaging piece is fixed is smaller than the hardness of the first side plate.

Preferably, the first engaging member has a concave portion. The second engaging member has a projection that engages with the recess.

Preferably, the plurality of segments are arranged in an axial direction as a vertical direction, and the first side plate is arranged below the plurality of segments. The recess is open on the lower surface of the first engaging member.

Preferably, the second engaging piece is detachably attached to the first side plate.

Preferably, the difference H1-H2 between the hardness H1 and the hardness H2 is 350HBW or more and 450HBW or less.

Preferably, the first engaging member is made of alloy tool steel.

Preferably, the second engaging member is made of chromium molybdenum steel.

Preferably, the mold has: a second side plate for molding the other of the outer surfaces of the pair of sidewalls; a third engaging member fixed to any of the segments; and a fourth engaging member fixed to the second side plate, having a hardness H4 smaller than a hardness H3 of the third engaging member, and engageable with the third engaging member.

The method for manufacturing a tire according to the present invention includes the steps of:

preparing a mold having: a plurality of sectors that shape the tread of the tire; a first side plate for molding one of outer surfaces of a pair of sidewalls of the tire; a first engaging piece fixed to any of the fan-shaped pieces; and a second engaging piece fixed to the first side plate, having a hardness H2 smaller than a hardness H1 of the first engaging piece, and engageable with the first engaging piece; preparing a green tire; feeding the green tire into the mold; and pressurizing and heating the green tire.

The method for manufacturing a mold according to the present invention includes the steps of: fixing the raw material of the fan-shaped piece to a processing jig; processing a cavity surface of a sector obtained from the sector raw material and a positioning part of a first clamping piece fixed to the sector in a state that the sector raw material is fixed to the processing jig; fixing the first engaging piece to the sector; preparing a first side plate for molding one of a pair of outer surfaces of sidewalls of a tire; and fixing a second engaging piece to the first side plate, the second engaging piece having a hardness H2 smaller than a hardness H1 of the first engaging piece and being engageable with the first engaging piece.

In the mold of the present invention, the second engaging piece fixed to the side plate has a hardness H2 smaller than a hardness H1 of the first engaging piece fixed to the sector. The second engaging member is more likely to be deformed or worn than the first engaging member. In this mold, by replacing the second engaging piece that has been deformed or worn, it is possible to suppress positional deviation in the circumferential direction. In this mold, replacement of the first engaging piece fixed to the sector is suppressed.

Drawings

Fig. 1 is a sectional view showing a mold according to an embodiment of the present invention.

Fig. 2 is a bottom view of the mold of fig. 1.

Fig. 3 is a perspective view of a second engaging member of the mold of fig. 1.

Fig. 4 is a perspective view showing a part of the side plate to which the second engaging piece of fig. 3 is fixed.

Fig. 5 is a perspective view of a first engaging member of the mold of fig. 1.

FIG. 6 is an exploded view of the sector showing the first catch removed from the sector.

Fig. 7 is an explanatory view showing a sector to which the first engaging piece of fig. 5 is fixed.

Fig. 8 is an explanatory view showing a part of the cavity surface of the mold of fig. 1.

Description of the reference symbols

2: a mold; 4: a green tire; 8: a sector; 8B: a lower surface; 10: a side plate; 14: a first engaging member; 14B: a lower surface; 16: a second engaging member; 18: a groove (recess); 22: a protrusion; 24: a screw; 26: an internal thread; 28: an opening part; 30: a mounting recess; 30B: a pin hole.

Detailed Description

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

A mould 2 is shown in fig. 1 and 2. Fig. 1 shows a cross section along the line I-I of fig. 2. In fig. 2 the bottom surface of the mould 2 is shown. Fig. 1 shows a green tire 4 set in a mold 2 and a part of an air bag 6 included in a vulcanizing device. The green tire 4 is pressurized and heated in a cavity formed by the mold 2 and the bladder 6, and a tire is obtained from the green tire 4.

As shown in fig. 2, the mold 2 has a ring shape. The double arrow a of fig. 2 indicates the circumferential direction of the die 2. The vertical direction in fig. 1 is the axial direction of the die 2, the horizontal direction in fig. 1 is the radial direction of the die 2, and the direction perpendicular to the drawing sheet is the circumferential direction of the die 2.

As shown in fig. 1 and 2, the mold 2 includes a plurality of segments 8, a pair of side plates 10, a pair of bead rings 12, a first engaging piece 14, and a second engaging piece 16.

In fig. 2, 9 segments 8 are arranged in the circumferential direction and formed in a ring shape. As shown in fig. 1, an inner peripheral surface 8A of the ring-shaped segment 8 abuts against an outer peripheral surface 10A of the side plate 10. The inner peripheral surface of the side plate 10 abuts against the outer peripheral surface of the bead ring 12.

A plurality of sectors 8 arranged in a ring shape shapes the tread of the tyre. A tread pattern including a plurality of grooves and land portions is formed on the tread. Although not shown in fig. 1, a plurality of irregularities for forming grooves and land portions are formed on the cavity surface 8C of the sector 8 for molding the tread pattern.

Such a sector 8 is preferably made of a material having excellent workability. The segment 8 obtained by casting from this material is preferably made of a material having excellent castability. Further, since the mold 2 is used, the segment 8 is preferably made of a material having high thermal conductivity, and is preferably made of a lightweight material. The material of the segment 8 is not particularly limited, but an aluminum alloy can be exemplified.

As shown in fig. 2, each side plate 10 has a ring shape. The side plate 10 is disposed radially inward of the plurality of segments 8. As shown in fig. 1, one side plate 10 in the axial direction is disposed on the lower side, and the other side plate 10 is disposed on the upper side. The pair of side plates 10 molds the outer surface of the sidewall of the tire. From the viewpoint of durability, the side plate 10 is preferably a material harder than the material of the sector 8. The material of the side plate 10 is not particularly limited, but an iron alloy such as alloy tool steel may be exemplified.

Each bead ring 12 has a ring shape. The bead ring 12 is disposed radially inward of the side plate 10. One of the bead rings 12 in the axial direction is disposed on the lower side, and the other bead ring 12 is disposed on the upper side. A pair of bead rings 12 shape the outer surface of the bead portion of the tire. The material of the bead ring 12 is not particularly limited, but the same material as that of the side plate 10 is used.

As shown in fig. 1, the first engaging piece 14 is attached and fixed to the sector 8. The first engaging piece 14 has a groove 18 as a concave portion. The groove 18 opens on the inner peripheral surface 14A and the lower surface 14B of the first engaging member 14. In this sector 8, the grooves 18 also open on the inner peripheral surface 8A and the lower surface 8B of the sector 8.

The second engaging piece 16 is attached and fixed to the lower side plate 10 as the first side plate. The second engaging piece 16 includes: a fixing portion 20 fixed to the side plate 10; and a protrusion 22 protruding from the outer peripheral surface 10A of the side plate 10. In the second engaging piece 16, the fixing portion 20 is attached to the side plate 10 by a screw 24. The second engaging piece 16 may be detachably fixed to the side plate 10 while being positioned and fixed. The mounting structure of the second engaging piece 16 is exemplified, and is not particularly limited.

The projection 22 of the second catch 16 is inserted into the slot 18 of the first catch 14. The second engaging member 16 engages with the first engaging member 14. By this engagement, the sector 8 to which the first engaging piece 14 is fixed is positioned in the circumferential direction with respect to the side plate 10. Each segment 8 abuts against other segments 8 adjacent in the circumferential direction. Thereby, the plurality of segments 8 are positioned in the circumferential direction with respect to the side plate 10.

The second catch 16 is shown in fig. 3. A female screw 26 for detachable attachment is formed in the fixing portion 20 of the second engaging piece 16. The width of the front end portion of the projection 22 of the second engaging member 16 gradually decreases toward the front end thereof.

The second engaging member 16 engages with the first engaging member 14. From the viewpoint of maintaining the positioning accuracy, it is preferable to use a material having hardness and excellent wear resistance as the material of the second engaging piece 16. The second engaging member 16 is constituted by an SCM 435. The material of the second engaging piece 16 is not particularly limited, but chromium molybdenum steel is exemplified as the material.

Fig. 4 shows a part of the side plate 10 to which the second engaging piece 16 is attached. In the second engaging piece 16, the side surface 20A of the fixing portion 20 abuts against the inner wall of the insertion hole 10B of the side plate 10 to perform positioning in the circumferential direction. The projection 22 of the second engaging piece 16 projects radially outward from the outer peripheral surface 10A of the side plate 10. The circumferential width of the projection 22 is gradually reduced toward the front end thereof. From the viewpoint of suppressing damage and deformation of the side plate 10, it is preferable to use a material softer than the material of the side plate 10 for the second engaging piece 16.

The first catch member 14 is shown in fig. 5. The groove 18 of the first engaging piece 14 opens to the inner peripheral surface 14A. The groove 18 is also open at the lower surface 14B. The width of the groove 18 is constant except for the opening 28 opened in the inner peripheral surface 14A. In the opening 28, the width of the groove 18 gradually increases toward the inner peripheral surface 14A as it goes toward the inside in the radial direction. The first engaging piece 14 has a pair of screw holes 14C and a pair of pin holes 14D.

The first engaging member 14 engages with the second engaging member 16. From the viewpoint of maintaining the positioning accuracy, it is preferable to use a material having hardness and excellent wear resistance as the material of the first engaging piece 14. The first engaging member 14 is constituted by SKD 11. The material of the first engaging piece 14 is not particularly limited, but an alloy tool steel can be exemplified as the material.

As shown in fig. 6, the sector 8 is formed with a mounting recess 30 that is open at the inner circumferential surface 8A and the lower surface 8B. The mounting recess 30 is formed with a pair of female screws 30A and a pair of pin holes 30B. The first engaging piece 14 is disposed in the mounting recess 30. The pair of male screws 32 are screwed into the female screws 30A through the screw holes 14C, respectively. A pair of fixing pins 34 are inserted into the pin holes 14D and the pin holes 30B, respectively. Thus, the first engaging piece 14 is attached and fixed to the sector 8.

In the mold 2, the fixing pins 34 are inserted into the pair of pin holes 30B to position the first engaging piece 14. The pair of pin holes 30B function as positioning portions of the first engaging piece 14 in the sector 8. The positioning portion is not particularly limited as long as the first engaging piece 14 can be positioned in the sector 8. For example, the wall surface 30C of the attachment recess 30 may position the first engaging piece 14.

Fig. 7 shows the segment 8 and the first detent 14 fixed to the segment 8. The groove 18 of the first engaging piece 14 opens to the inner peripheral surface 14A. The groove 18 also opens at the lower surface 14B. In other words, the groove 18 opens at the inner peripheral surface 8A and at the lower surface 8B of the sector 8.

Fig. 8 shows a part of the cavity surface 8C of the sector 8 and the cavity surface 10C of the side plate 10 in the mold 2 of fig. 1. In the mold 2, the inner peripheral surface 8A of the segment 8 abuts against the outer peripheral surface 10A of the side plate 10.

The cavity surface 8C has a surface 36 and a plurality of recesses 38 recessed from the surface 36. The grooves and land portions of the tread pattern are shaped by the surface 36 and the recesses 38. In the mold 2, the cavity surface 10C of the side plate 10 also has a surface 40 and a recess 42 recessed from the surface 40. In the mold 2, a concave-convex shape continuous with a land portion or a groove formed in a tread is also formed on the outer surface of the sidewall of the tire.

A method of manufacturing a tire using the mold 2 will be described. The mold 2 is prepared (step 1). The mold 2 is mounted on a vulcanizing device not shown. A green tire 4 is prepared (step 2). The vulcanizing device separates the pair of side plates 10 in the vertical direction. The vulcanizing device moves each sector 8 radially outward. The individual sectors 8 are separated from each other. Thus, the mold 2 is opened (step 3).

A green tire 4 is put into the opened mold 2 (step 4). The vulcanizing device brings a pair of side plates 10 close. The vulcanizing device moves each sector 8 radially inward. The first engaging piece 14 attached to the sector 8 engages with the second engaging piece 16 of the side plate 10. Each sector 8 abuts against other circumferentially adjacent sectors 8. Thus, as shown in fig. 1, the mold 2 is closed (step 5). The green tire 4 is pressurized and heated in the mold 2 (step 6). Thus, a tire is obtained from the green tire 4.

Here, a method of manufacturing the sector 8 will be explained. Although not shown, a sector raw material is prepared (step 1'). And (2) mounting and fixing the fan-shaped raw material on the processing jig (step 2'). In a state of being fixed to the machining jig, the cavity surface 8C of the sector 8 and the mounting recess 30 are cut out of the sector raw material (step 3'). In this step (step 3'), the pair of pin holes 30B (see fig. 6) as the positioning portions of the first engaging piece 14 are machined together with the cavity surface 8C by cutting or the like. The sector material is processed to obtain sectors 8 (step 4'). The first engaging member 14 is attached and fixed to the sector 8 (step 5').

Similarly, a method of manufacturing the side plate 10 will be explained. Although not shown, a side plate material is prepared (step 1 "). The side plate material is mounted and fixed to the processing jig (step 2 "). In the side plate material, the insertion hole 10B as the positioning portion is machined by cutting or the like together with the cavity surface 10C in a state of being fixed to the machining jig (step 3 "). The side plate material is processed to obtain the side plate 10 (step 4 "). The second engaging piece 16 is attached to and fixed to the side plate 10 (step 5 ").

The mold 2 has a first engaging piece 14 fixed to at least 1 of the plurality of segments 8 and a second engaging piece 16 fixed to the side plate 10. The second engaging piece 16 can engage with the first engaging piece 14. By this engagement, the segment 8 is positioned in the circumferential direction with respect to the side plate 10.

The second engaging member 16 has a hardness H2 that is less than the hardness H1 of the first engaging member 14. In the mold 2, the second engaging piece 16 is more likely to be worn and damaged than the first engaging piece 14. In this mold 2, abrasion and damage of the first engaging piece 14 are suppressed. In the mold 2, replacement of the first engaging piece 14 fixed to the sector 8 can be suppressed.

The hardness in the present invention was compared with a value measured under a test force of 29.4(kN) using an indenter of 10mm in diameter of cemented carbide, based on "Brinell hardness test-test method" of JIS Z2243.

In the mold 2, the hardness of the segment 8 is smaller than that of the side plate 10. Replacement of the first engaging piece 14 fixed to the sector 8 as described above is liable to impair the positional accuracy of the first engaging piece 14. The second catch 16 having a hardness H2 that is less than the hardness H1 of the first catch 14 fits into the mold 2 having such a sector 8.

In the mold 2, the first engaging piece 14 has a groove 18 as a concave portion. The second engaging member 16 has a projection 22 that engages with the groove 18. The second engaging piece 16 having the protrusion 22 protruding from the side plate 10 is likely to receive an external force. The first engaging piece 14 can be fixed so as not to protrude from the sector 8. The first engaging piece 14 is less likely to receive an external force than the second engaging piece 16. In the mold 2, replacement of the first engaging piece 14 can be further suppressed.

In the mold 2, the groove 18 is formed in the first engaging piece 14 fixed to the sector 8, but the present invention is not limited thereto. The groove 18 may be formed in the second engaging piece 16 fixed to the side plate 10, and the protrusion 22 may be formed in the first engaging piece 14.

In particular, in the mold 2 in which the hardness of the sector 8 is smaller than that of the side plate 10, the positional accuracy of the first engaging piece 14 is easily impaired by the replacement of the first engaging piece 14. In such a mold 2, it is preferable that the first engaging piece 14 has a groove 18 as a concave portion, and the second engaging piece 16 has a protrusion 22 that engages with the groove 18.

In the mold 2, the plurality of segments 8 are arranged with the axial direction being the vertical direction, and one side plate 10 is arranged below the plurality of segments 8. The groove 18 of the first click member 14 opens at the lower surface 14B. In this mold 2, foreign matter is less likely to remain in the groove 18. When the green tire 4 is put into the mold 2 and the tire is taken out from the mold 2, foreign matter is not easily left in the groove 18. In the mold 2, the occurrence of positional deviation of the sector 8 and the side plate 10 due to the remaining of foreign matter is suppressed.

In the mold 2, the second engaging piece 16 is detachably attached to the side plate 10. By replacing the second engaging piece 16, the positional deviation can be suppressed. In particular, in the mold 2 in which the hardness of the segment 8 is smaller than that of the side plate 10, the replacement of the first engaging piece 14 of the segment 8 can be suppressed by replacing the second engaging piece 16. The mold 2 can suppress positional deviation of the segment 8 and the side plate 10 for a long period of time.

From the viewpoint of suppressing abrasion or damage of the first engaging member 14, the brinell hardness H1 is preferably 600HBW or more, more preferably 620HBW or more, and particularly preferably 640HBW or more. The hardness H1 has no preferable upper limit, but is, for example, 660HBW or less. The material of the first engaging member 14 is preferably alloy tool steel.

From the viewpoint of suppressing abrasion or damage of the second engaging member 16, the brinell hardness H2 is preferably 200HBW or more, more preferably 220HBW or more, and particularly preferably 240HBW or more. On the other hand, the hardness H2 is preferably 300HBW or less, more preferably 280HBW or less, and particularly preferably 260HBW or less, from the viewpoint of suppressing abrasion and damage of the engaged first engaging piece 14. The material of the second engaging member 16 is preferably chrome molybdenum steel.

From the viewpoint of suppressing wear and damage of the first engaging piece 14, the difference H1-H2 between the hardness H1 and the hardness H2 is preferably 350HBW or more, more preferably 370HBW or more, and particularly preferably 390HBW or more. On the other hand, the second engaging piece 16 having a large difference in hardness is easily worn or damaged. From the viewpoint of suppressing such abrasion or damage, the difference H1-H2 is preferably 450HBW or less, more preferably 430HBW or less, and particularly preferably 410HBW or less.

As shown in fig. 8, in the mold 2, the concave portion 42 of the cavity surface 10C of the side plate 10 is formed so as to be continuous with the concave portion 38 of the cavity surface 8C of the sector 8. In the mold 2, a concave-convex shape continuous with a land portion or a groove formed in a tread of a tire is formed on an outer surface of a sidewall. In such a tire, the positional deviation of the sectors 8 from the side plates 10 in the circumferential direction impairs the appearance of the tire. The mold 2 is suitable for the manufacture of such a tire.

Although not shown, the mold 2 may have a third engaging element fixed to any one of the plurality of segments 8 and a fourth engaging element fixed to the other side plate 10 positioned above. The fourth engaging member has a hardness H4 less than the hardness H3 of the third engaging member. By having the third engaging piece and the fourth engaging piece, the positional deviation in the circumferential direction between the sector 8 and the upper side plate 10 as the second side plate can be suppressed.

For example, a third engaging piece similar to the first engaging piece 14 is attached and fixed to the upper surface of the sector piece 8 and the upper inner peripheral surface 8A so as to be opened. A fourth engaging piece similar to the second engaging piece 16 is attached and fixed to the other side plate 10.

The third engaging element may be fixed to the sector 8 to which the first engaging element 14 is fixed, or may be fixed to another sector 8. For example, the third engaging member may be fixed to the sector 8 that is farthest in the circumferential direction from the sector 8 to which the first engaging member 14 is fixed. Further, the first engaging piece 14 or the third engaging piece may be fixed to each of the plurality of segments 8, and further, to each of all the segments 8. A plurality of second engaging elements 16 and a plurality of fourth engaging elements that engage with the plurality of first engaging elements 14 or the third engaging elements may be fixed to the side plate 10.

In the manufacturing method of the mold 2, the cavity surface 8C and the pair of pin holes 30B are preferably machined in a state where the sector material is fixed to the sector machining jig, from the viewpoint of easily improving the positional accuracy of the first engaging piece 14. Similarly, from the viewpoint of easily improving the positional accuracy of the second engaging piece 16, it is preferable that the cavity surface 10C and the insertion hole 10B as the positioning portion are processed in a state where the side plate material is fixed to the side plate processing jig.

[ examples ] A method for producing a compound

The effects of the present invention will be clarified by the following examples, but the present invention should not be construed as being limited to the descriptions of the examples.

[ examples ]

The mold of fig. 1 was prepared. The mold had 9 segments. A first engaging piece is fixed to the lower side of the 1 st segment arranged in the circumferential direction. Further, a third engaging piece similar to the first engaging piece is fixed to the upper side of the 5 th segment arranged in the circumferential direction. A second engaging member that engages with the first engaging member is fixed to one (lower side plate) of the pair of side plates. A fourth engaging member similar to the second engaging member and engaged with the third engaging member is fixed to the other side (upper side plate). The rest is the same as the existing mold. 1400 tires were manufactured using the mold.

[ examples ]

1400 tires were manufactured in the same manner as in the examples, except that the existing mold was used.

[ evaluation of positional deviation ]

15 tires were randomly drawn out of every 100 tires of the manufactured examples. In these tires, the circumferential positional deviation was measured at the boundary between the portion molded from the segment and the portion molded from the side plate. Similarly, the tire of the comparative example was measured for the positional deviation in the circumferential direction. The results are shown in Table 1. In table 1, the maximum value, the minimum value, and the average value in the examples and comparative examples are expressed by an index in which the amount of positional deviation in the comparative example is 100. The smaller the index, the smaller the positional deviation amount.

TABLE 1 evaluation results

As shown in table 1, the evaluation was higher in the manufacturing method using the mold of the example than in the manufacturing method of the comparative example. The superiority of the present invention is apparent from the evaluation results.

Industrial applicability

The method described above can be widely applied to the manufacture of tires using molds having annular segments and a pair of side plates.

Claims

1. A mold, comprising:

a plurality of sectors that shape the tread of the tire;

a first side plate for molding one of outer surfaces of a pair of sidewalls of the tire;

a first engaging piece fixed to any of the fan-shaped pieces; and

and a second engaging piece that is fixed to the first side plate, has a hardness H2 that is lower than the hardness H1 of the first engaging piece, and is capable of engaging with the first engaging piece.

2. The mold of claim 1,

the hardness of the sector to which the first engaging piece is fixed is smaller than the hardness of the first side plate.

3. The mold according to claim 1 or 2,

the first engaging member has a concave portion, and the second engaging member has a protrusion that engages with the concave portion.

4. The mold of claim 3,

the plurality of segments are arranged in the vertical direction in the axial direction,

the first side plate is disposed on a lower side of the plurality of segments,

the recess is open on the lower surface of the first engaging member.

5. The mold according to any one of claims 1 to 4,

the second engaging piece is detachably attached to the first side plate.

6. The mold according to any one of claims 1 to 5,

the difference H1-H2 between the hardness H1 and the hardness H2 is 350HBW or more and 450HBW or less.

7. The mold according to any one of claims 1 to 6,

the first clamping piece is made of alloy tool steel.

8. The mold according to any one of claims 1 to 7,

the second clamping piece is made of chromium molybdenum steel.

9. The mold according to any one of claims 1 to 8,

the mold has:

a second side plate for molding the other of the outer surfaces of the pair of sidewalls;

a third engaging member fixed to any of the segments; and

and a fourth engaging piece fixed to the second side plate, having a hardness H4 smaller than a hardness H3 of the third engaging piece, and capable of engaging with the third engaging piece.

10. A method for manufacturing a tire, the method comprising the steps of:

preparing a mold having: a plurality of sectors that shape the tread of the tire; a first side plate for molding one of outer surfaces of a pair of sidewalls of the tire; a first engaging piece fixed to any of the fan-shaped pieces; and a second engaging piece fixed to the first side plate, having a hardness H2 smaller than a hardness H1 of the first engaging piece, and engageable with the first engaging piece;

preparing a green tire;

feeding the green tire into the mold; and

pressurizing and heating the green tire.

11. A method for manufacturing a mold, comprising the steps of:

fixing the raw material of the fan-shaped piece to a processing jig;

processing a cavity surface of a sector obtained from the sector raw material and a positioning part of a first clamping piece fixed to the sector in a state that the sector raw material is fixed to the processing jig;

fixing the first engaging piece to the sector;

preparing a first side plate for molding one of a pair of outer surfaces of sidewalls of a tire; and

a second engaging piece is fixed to the first side plate, the second engaging piece having a hardness H2 smaller than a hardness H1 of the first engaging piece and being engageable with the first engaging piece.