Tire molding die and method for manufacturing tires using the same

Abstract

To provide a tire-forming die that forms a pinch capable of facilitating resection and a tire-manufacturing method using the same.SOLUTION: A tire-forming die includes a first die and a second die that is mated with the first die. When a mating surface of the first die is designated as a first mating surface and a mating surface of the second die is designated as a second mating surface, the first mating surface is provided with a plurality of first recesses having rubber introduction openings in a tire-forming surface, and the first mating surface or the second mating surface is provided with a second recess coupled at least when the adjacent first recesses are mated.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a tire molding die and a method for manufacturing a tire using the same.

Background Art

[0002] Patent Document 1 discloses a tire molding die including a side mold forming a side surface of a tire and a plurality of sectors forming a tread surface of the tire, and a rubber introduction groove is provided on a fitting surface between the side mold and the sectors. A tire manufactured by the tire molding die forms an annular pinch (a rubber burr formed on the fitting surface) continuously connected to the tire by the rubber introduction groove.

[0003] It is assumed that the excision of the pinch is performed using a turntable to stabilize the cutting position. Specifically, the tire is placed on the turntable, the cutter is inserted into the pinch, and the pinch is excised by rotating the tire in the tire circumferential direction. Therefore, in order to excise the pinch, it is desired to facilitate the excision operation of the pinch because a turntable is required and the tire needs to be transported to the turntable.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present disclosure is to provide a tire molding die that forms a pinch that can be easily excised and a method for manufacturing a tire using the same.

Means for Solving the Problems

[0006] The tire molding die of this disclosure comprises a first mold and a second mold that fits with the first mold, wherein the fitting surface of the first mold is designated as the first fitting surface and the fitting surface of the second mold is designated as the second fitting surface, the first fitting surface is provided with a plurality of first recesses having rubber inlet openings on the tire forming surface, and the first fitting surface or the second fitting surface is provided with second recesses that connect when at least adjacent first recesses are fitted together.

[0007] The tire manufacturing method of the present disclosure includes the step of setting an unvulcanized tire in the tire molding die and performing vulcanization molding by heating and pressurizing the unvulcanized tire. [Brief explanation of the drawing]

[0008] [Figure 1] Side view of a pneumatic tire manufactured by the tire molding die according to Embodiment 1 [Figure 2] Longitudinal cross-sectional view of the tire molding die according to the same embodiment. [Figure 3] This figure shows the relationship between the first and second concave sections when viewing the first type from the direction of arrow III in Figure 2, omitting the second type. [Figure 4] Longitudinal cross-sectional view of the tire molding die according to Embodiment 2 [Figure 5] This figure shows the relationship between the first and second concave sections when viewing the first type from the direction V, as indicated by the arrow in Figure 4, while omitting the second type. [Figure 6] Sectional view along line VI-VI in Figure 4 [Figure 7] Cross-sectional view of the tire molding die according to Embodiment 3 [Figure 8] This figure shows the relationship between the first and second concave sections when viewing the first type from the direction of arrow VIII in Figure 7, omitting the second type. [Figure 9] Longitudinal cross-sectional view of the tire molding die according to Embodiment 4 [Figure 10] Enlarged view of region X in Figure 9 [Figure 11] Enlarged view of the main part of the first fitting surface showing the relationship between the first recess and the second recess in another embodiment. [Figure 12] Enlarged view of the main part of the first fitting surface showing the relationship between the first recess and the second recess in another embodiment. [Figure 13] Enlarged view of the main part of the first fitting surface showing the relationship between the first concave and the second concave in another embodiment

Mode for Carrying Out the Invention

[0009] [Embodiment 1] Hereinafter, Embodiment 1 in a tire mold will be described with reference to FIGS. 1 to 3. In each figure (similarly for FIGS. 4 to 13), the dimensional ratio in the drawing and the actual dimensional ratio do not necessarily match, and the dimensional ratios between the drawings do not necessarily match either.

[0010] In each figure, the first direction D1 is the tire axial direction D1 parallel to the tire rotation axis, the second direction D2 is the tire diameter direction D2 which is the diameter direction of the tire, and the third direction D3 is the tire circumferential direction D3 around the tire rotation axis.

[0011] In the tire axial direction D1, the inner side is the side close to the tire equatorial plane, and the outer side is the side far from the tire equatorial plane. Also, in the tire diameter direction D2, the inner side is the side close to the tire rotation axis, and the outer side is the side far from the tire rotation axis. The tire equatorial plane is a plane orthogonal to the tire rotation axis and located at the center of the tire in the tire axial direction D1.

[0012] Regarding the tire mold as well, the above directions D1 to D3 and the like will be used for explanation in a state where a tire not shown is set.[[ID=X]] [[ID=Y]]

[0013] [[ID=Z]] FIG. 1 is a side view of a pneumatic tire manufactured by the tire mold according to Embodiment 1. As shown in FIG. 1, a pneumatic tire (hereinafter, also simply referred to as "tire") 100 vulcanized and molded by the tire mold includes a pair of bead portions 101, a pair of sidewalls 102 extending outward in the tire diameter direction D2 from each bead portion 101, and a tread 103 continuous with the outer ends in the tire diameter direction D2 of the pair of sidewalls 102.

[0014] <X On the outer surface of the sidewall 102, a decorative area 104 extending along the tire circumferential direction D3 is provided. In the decorative area 104, a serration 105 having a constant width and extending along the tire circumferential direction D3, and marks (not shown) such as characters, figures, and symbols are provided. In the present embodiment, the serration 105 is formed in an annular region, but is not limited thereto.

[0015] The serration 105 includes a plurality of ridges 105a extending along the tire radial direction D2. The ridges 105a are protrusions protruding outward in the tire axial direction and are arranged in parallel in an annular shape along the tire circumferential direction D3. The ridges 105a may extend obliquely with respect to the tire radial direction D2. The ridges 105a extend to the split position 106 between the side mold 2 and the sector 3 in the tire molding die 1 (see FIG. 2) described later. In the present embodiment, the ridge 105a has a substantially triangular cross section, but is not limited thereto.

[0016] FIG. 2 is a longitudinal sectional view of the tire molding die 1 according to Embodiment 1. FIG. 3 is a view showing the relationship between the first recess 21 and the second recess 31 when the second mold (sector 3) is omitted and the first mold (side mold 2) is viewed from the direction of arrow III in FIG. 2.

[0017] As shown in FIG. 2, the tire molding die 1 includes a first mold and a second mold that fits with the first mold. In Embodiment 1, an example is shown in which the first mold is the side mold 2 and the second mold is the sector 3. In the present embodiment, the tire molding die 1 is a segmented mold, but is not limited thereto. For example, the tire molding die 1 may be a two-piece mold. The tire molding die 1 includes a tire forming surface 1b that contacts the outer surface of the set tire. The tire forming surface 1b includes the inner surface of the sector 3 and the inner surface of the side mold 2.

[0018] In the present embodiment, the tire molding die 1 includes a pair of first molds (side molds 2, 2) and a plurality of second molds (sectors 3). Note that it is not limited to the above, and the first mold may be a sector and the second mold may be a side mold.

[0019] A pair of side molds 2,2 are provided on the outside of an unvulcanized tire (not shown) in the tire axial direction D1. Multiple sectors 3 are provided on the sides of the side molds 2 and are arranged in parallel in an annular manner along the tire circumferential direction D3 of the unvulcanized tire. One side mold 2 is movable toward and toward the other side mold 2 in the tire axial direction D1, and the multiple sectors 3 are movable toward and toward the side molds 2 in the tire radial direction D2.

[0020] The side mold 2 is formed of a steel material such as general structural rolled steel (e.g., SS400). The sector 3 is formed of aluminum or an aluminum alloy (e.g., Al-Cu, Al-Mg, Al-Mn, or Al-Si alloys).

[0021] Of the mating surfaces between the side mold 2 and the sector 3, the mating surface of the side mold 2 is designated as the first mating surface 2a, and the mating surface of the sector 3 is designated as the second mating surface 3a. Of the tire forming surfaces 1b, the tire forming surface of the side mold 2 is designated as the first forming surface 2b, and the tire forming surface (tread forming surface) of the sector 3 is designated as the second forming surface 3b. In this embodiment, the first forming surface 2b is the tire forming surface that forms the sidewall 102 in Figure 1, and the second forming surface 3b is the tread forming surface that forms the tread 103 in Figure 1.

[0022] It is preferable that the edges formed by the first fitting surface 2a and the first forming surface 2b are chamfered. This suppresses the pinching of the unvulcanized tire rubber when the side mold 2 and sector 3 are fitted together. The same applies to the edges formed by the second fitting surface 3a and the second forming surface 3b.

[0023] The first mating surface 2a is provided with a plurality of first recesses 21 having rubber inlet openings 211 on the tire forming surface 1b (first forming surface 2b). The first recesses 21 are arranged in parallel along the tire circumferential direction D3. The first recesses 21 are provided intermittently along the tire circumferential direction D3. By providing the first recesses 21 intermittently, the edges between the second mating surface 3a and the second forming surface 3b are less prone to wear compared to when the first recesses 21 are provided continuously.

[0024] The first recess 21 is provided on at least one side of the pair of side molds 2,2. In this embodiment, the first recess 21 is provided on both sides of the pair of side molds 2,2.

[0025] The first recess 21 opens at one end to the first fitting surface 2a in the tire radial direction D2, and terminates at the other end on the first forming surface 2b. The first recess 21 is a groove that extends inward from the first fitting surface 2a in the tire radial direction D2. In this embodiment, the first recess 21 is a groove that forms the ridge 105a of the serration 105 in Figure 1. The first recess 21 is formed in a substantially triangular cross-section.

[0026] The outer end of the first recess 21 in the tire axial direction D1 is inclined outward in the tire axial direction D1 near the first fitting surface 2a. In this embodiment, the outer end of the first recess 21 in the tire axial direction D1 is curved when viewed in the tire circumferential direction D3. Note that the first recess 21 is not limited to the above.

[0027] The first mating surface 2a or the second mating surface 3a is provided with a second recess 31 that connects when at least two adjacent first recesses 21 are mated together. By providing the first recess 21 and the second recess 31, it is possible to form pinches that are intermittently connected to the tire 100 in Figure 1. This makes it easier to tear off the pinches compared to manually cutting off pinches that are continuously connected to the tire 100, thus simplifying the manual pinch cutting process. As a result, for example, pinches can be easily cut off without using a turntable.

[0028] In this embodiment, the second recess 31 is provided on the second fitting surface 3a. This makes it easier for the pinch to dislodge from the second recess 31 when the sector 3 is separated outward in the tire radial direction D2. As a result, it is possible to prevent the pinch from being torn off when the sector 3 is separated, and to prevent the pinch from remaining in the second recess 31.

[0029] The second recess 31 is provided on at least one side in the tire axial direction D1. In this embodiment, the second recess 31 is provided on the second fitting surfaces 3a on both sides in the tire axial direction D1. The pair of second recesses 31 are each formed symmetrically with respect to the tire equatorial plane S1. Note that one or both of the second recesses 31 may be provided on the first fitting surface 2a. Furthermore, the pair of second recesses 31 may each be formed asymmetrically.

[0030] The second recess 31 is a groove that extends continuously along the tire circumferential direction D3 (see Figure 3). One end of the second recess 31 opens to one side of the fitting surface of sector 3 in the tire circumferential direction, and the other end opens to the other side of the fitting surface of sector 3 in the tire circumferential direction. As a result, when multiple sectors 3 connected in the tire circumferential direction D3 are fitted together, an annular groove is formed by multiple second recesses 31. The fitting surface of sector 3 in the tire circumferential direction D3 is the fitting surface between sector 3 and other sectors.

[0031] The second recess 31 preferably has an angular cross-section. This makes it easier for the worker to grasp the pinch and facilitates the pinch cutting process. In this embodiment, the second recess 31 is formed in a trapezoidal cross-section, but is not limited to this. For example, the second recess 31 may be formed in a triangular or semicircular cross-section.

[0032] The second recess 31 is formed at a position away from the second forming surface 3b. Preferably, the second recess 31 is formed wider toward the second fitting surface 3a. This makes it easier for the pinch to come out of the second recess 31 and prevents the pinch from being torn off when the sector 3 is separated. The outer end of the second recess 31 in the tire axial direction D1 is located further outward in the tire axial direction D1 than the outer end of the first recess 21 in the tire axial direction D1.

[0033] The width W2 of the second recess 31 in the tire axial direction D1 is preferably 2 mm or more. This makes it easier for the worker to grasp the pinch and facilitates the pinch cutting process. Furthermore, the width W2 is preferably 10 mm or less. This prevents a shortage of rubber for forming the pinch in the second recess 31.

[0034] The depth H2 of the second recess 31 in the tire radial direction D2 is preferably 1 mm or more. This ensures the strength of the pinch and prevents it from being torn apart at any point other than the connection between the ridge 105a and the pinch in Figure 1 when the pinch is pulled. The depth H2 is preferably 10 mm or less. This prevents a shortage of rubber for forming the pinch in the second recess 31.

[0035] The width W2 of the second recess 31 is preferably greater than the depth H2 of the second recess 31. This makes it easier for the worker to grasp the pinch and facilitates the pinch cutting process.

[0036] The distance L1 from the second forming surface 3b to the outer end of the second recess 31 in the tire axial direction D1 is preferably 2.5 mm or more. This ensures that the width W2 of the second recess 31 is secured, making it easier for the worker to grasp the pinch and facilitating the pinch cutting operation. The distance L1 is preferably 20 mm or less. This prevents a shortage of rubber for forming the pinch in the second recess 31.

[0037] The width W2 of the second recess 31 is preferably 50% or more of the distance L1 to the outer edge of the second recess 31. This ensures that the width W2 of the second recess 31 is secured, making it easier for the worker to grasp the pinch and facilitating the pinch cutting operation. By setting the width W2 to 90% or less of the distance L1, it is possible to prevent a shortage of rubber for forming the pinch in the second recess 31.

[0038] As shown in Figure 3, the width W1 of the first recess 21 along the tire circumferential direction D3 is preferably 0.5 mm or more. This allows for good introduction of rubber into the second recess 31. It also prevents the ridge 105a in Figure 1 from being torn off when the side mold 2 separates or when the pinch formed by the second recess 31 is torn off. The width W1 is preferably 5 mm or less. This allows the serrations 105 to be provided in an appropriate size. The width W1 of the first recess 21 is substantially the same as the width of the rubber inlet 211.

[0039] The depth H1 of the first recess 21 in the tire axial direction D1 is preferably 0.3 mm or more. This allows the second recess 31 to be separated from the tire forming surface 1b, suppressing the pinch from continuously connecting to the outer surface of the tire. The depth H1 is preferably 3 mm or less. This allows for good introduction of rubber into the second recess 31.

[0040] The spacing P1 of the first recesses 21 is preferably 0.5 mm or more. This makes it easier to remove pinches. The spacing P1 is preferably 10 mm or less. This prevents pinches from forming in the gap between the first fitting surface 2a and the second fitting surface 3a (see Figure 2), where the first recesses 21 are not provided.

[0041] The width W1 of the first recess 21 is preferably 50% or more of the installation interval P1 of the first recess 21. This prevents the formation of pinches in the gap between the first fitting surface 2a and the second fitting surface 3a (see Figure 2), where the first recess 21 is not provided. The width W1 is preferably 90% or less of the installation interval P1. This makes it easier to remove pinches.

[0042] The width W3 of the connecting portion 4 (hatched portion in Figure 3) between the first recess 21 and the second recess 31, along the tire circumferential direction D3, is preferably 0.2 mm or more. This allows for good introduction of rubber into the second recess 31. It also prevents the pinch from being torn off when the sectors 3 separate. By setting the width W3 to 3 mm or less, an easily removable pinch can be formed, making the pinch removal work easier. In this embodiment, the width W3 of the connecting portion 4 is smaller than the width W1 of the first recess 21.

[0043] The thickness T1 of the connecting portion 4 in the tire axial direction D1 is preferably 0.1 mm or more. This prevents the pinch from being torn off when sector 3 separates. The thickness T1 is preferably 2 mm or less. This allows for the formation of a pinch that is easy to cut, making the pinch cutting operation easier.

[0044] The area of ​​the connecting part 4 is 0.01 mm². 2 It is preferable that the above conditions are met. This prevents the pinch from being torn off when sector 3 separates. The area of ​​the connecting portion 4 is 4 mm². 2 The following is preferable. This allows the pinch to be torn off by the worker's hand, making the pinch removal work easier. In this embodiment, the area of ​​the connecting portion 4 is smaller than the area of ​​the rubber inlet 211.

[0045] [Embodiment 2] Next, the tire molding die 1 according to Embodiment 2 will be described with reference to Figures 4 to 6. The tire molding die 1 according to Embodiment 2 differs from the tire molding die 1 according to Embodiment 1 in that pinches are formed in both the first recess 21 and the second recess 31. Embodiment 2 shows an example where the first mold is the side mold 2 and the second mold is the sector 3. The same configuration as in Embodiment 1 will not be described.

[0046] Figure 4 is a longitudinal cross-sectional view of the tire molding die 1 according to Embodiment 2. Figure 5 is a diagram showing the relationship between the first recess 21 and the second recess 31 when the side mold 2 is viewed from the direction V of the arrow in Figure 4, with sector 3 omitted. Figure 6 is a cross-sectional view taken along the line VI-VI in Figure 4.

[0047] As shown in Figure 4, the first recess 21 is a groove extending from the tire forming surface 1b (first forming surface 2b) along the tire axial direction D1. One end of the first recess 21 terminates on the first fitting surface 2a, and the other end opens onto the first forming surface 2b. The groove depth of the first recess 21 decreases toward the first forming surface 2b (towards the inside of the tire axial direction D1).

[0048] The second recess 31 is a groove extending from the tire forming surface 1b (second forming surface 3b) along the tire axial direction D1. The second recess 31 is provided with a rubber inlet 311 on the second forming surface 3b. One end of the second recess 31 terminates on the second fitting surface 3a, and the other end opens to the second forming surface 3b. The groove depth of the second recess 31 decreases toward the second forming surface 3b (towards the inside of the tire axial direction D1). In this embodiment, the second recess 31 is formed in the sector 3, but is not limited to this. The second recess 31 may also be formed in the side mold 2. The second recess 31 may have the same shape as the second recess 31 of Embodiment 1 (see Figures 2 and 3).

[0049] The depth H3 of the rubber inlet 211 of the first recess 21 in the tire radial direction D2 is preferably 0.2 mm or more. This allows for good introduction of rubber into the first recess 21. It also prevents the pinch from being torn off when the side mold 2 separates. The depth H3 is preferably 5 mm or less. This makes the pinch removal work easier. The same applies to the depth H4 of the rubber inlet 311 of the second recess 31 in the tire radial direction D2.

[0050] As shown in Figure 5, the first recess 21 is formed to be narrow toward the first forming surface 2b (towards the inside in the tire axial direction D1). The second recess 31 is formed to be narrow toward the second forming surface 3b (towards the inside in the tire axial direction D1). The second recess 31 is provided between adjacent first recesses 21, at least when fitted.

[0051] The connecting portion 4 of the first recess 21 and the second recess 31 is provided at a position away from the tire forming surface 1b. The first recess 21 and the second recess 31 are preferably angular in shape. This makes it easier for the worker to grasp the pinch and facilitates the pinch cutting process.

[0052] As shown in Figures 5 and 6, in this embodiment, the first recess 21 is formed in a substantially triangular pyramidal shape, that is, a triangular cross-section (isosceles triangular cross-section). The deepest part of the first recess 21 (the apex of the triangular pyramid) is located inward in the tire axis direction D1 from the end of the first recess 21. The end of the first recess 21 is substantially parallel to the first forming surface 2b when viewed in the tire radial direction D2. Note that the first recess 21 is not limited to the above, and may be formed in a scalene triangular cross-section or a substantially semicircular cross-section, for example.

[0053] In this embodiment, the second recess 31 is formed in a substantially triangular pyramidal shape, that is, a triangular cross-section (an isosceles triangular cross-section). The deepest part of the second recess 31 (the apex of the triangular pyramid) is located inward in the tire axis direction D1 from the end of the second recess 31. The end of the second recess 31 is substantially parallel to the second forming surface 3b (see Figure 4) when viewed in the tire radial direction D2. Note that the second recess 31 is not limited to the above, and may be formed in a scalene triangular cross-section or a substantially semicircular cross-section, for example.

[0054] As shown in Figure 5, it is preferable that the end of the second recess 31 is located further outward in the tire axial direction D1 than the end of the first recess 21. This prevents the area of ​​the connecting portion 4 between the first recess 21 and the second recess 31 from becoming smaller due to misalignment during fitting of the side mold 2 and sector 3, or manufacturing errors.

[0055] The width W4 of the rubber inlet 211 of the first recess 21 along the tire circumferential direction D3 is preferably 0.4 mm or more. This prevents the pinch from being torn off when the side mold 2 separates. The width W4 is preferably 10 mm or less. This allows for good introduction of rubber into the first recess 21. It also allows for the formation of a pinch that is easy to cut, making the pinch cutting work easier. The same applies to the width W5 of the rubber inlet 311 of the second recess 31 along the tire circumferential direction D3.

[0056] The area of ​​the rubber inlet 211 of the first recess 21 is 0.04 mm². 2 It is preferable that the area be greater than or equal to the area of ​​the rubber inlet 211. This allows for good introduction of the rubber into the first recess 21. It also prevents the pinch from being torn off when the side mold 2 separates. The area of ​​the rubber inlet 211 is 25 mm². 2 The following is preferable. This allows the pinch to be torn off by the worker's hand, making the pinch removal work easier. The same applies to the area of ​​the rubber inlet 311 of the second recess 31.

[0057] The area of ​​the connecting portion 4 is preferably larger than the area of ​​the rubber inlet 211 and the area of ​​the rubber inlet 311. This prevents the pinch from being torn off at any point other than the connection point with the tire when the pinch is pulled.

[0058] The spacing P2 of the first recess 21 is preferably 0.6 mm or more. This facilitates the pinch removal process. The spacing P2 is preferably 20 mm or less. This prevents the formation of pinches in the gap between the first fitting surface 2a and the second fitting surface 3a (see Figure 4), where the first recess 21 is not provided. The same applies to the spacing P3 of the second recess 31.

[0059] The width W4 of the rubber inlet 211 of the first recess 21 is preferably 30% or more of the installation interval P2 of the first recess 21. This allows for good introduction of rubber into the first recess 21. The width W4 is preferably 90% or less of the installation interval P2. This prevents the pinches from being torn off when the sectors 3 are separated. The same applies to the ratio of the width W5 of the rubber inlet 311 of the second recess 31 to the installation interval P3 of the second recess 31.

[0060] [Embodiment 3] Next, the tire molding die 1 according to Embodiment 3 will be described with reference to Figures 7 and 8. The tire molding die 1 according to Embodiment 3 differs from the tire molding die 1 according to Embodiment 1 in that both the first and second molds are sectors. Embodiment 3 shows an example in which the first mold is sector 6 and the second mold is sector 7. The description of a configuration similar to sector 3 in Embodiment 1 will be omitted.

[0061] Figure 7 is a cross-sectional view of the tire molding die 1 according to Embodiment 3. Figure 8 is a diagram showing the relationship between the first recess 61 and the second recess 71 when sector 6 is viewed from the direction of arrow VIII in Figure 7, omitting sector 7.

[0062] As shown in Figure 7, of the mating surfaces of sector 6 and sector 7, the mating surface of sector 6 is designated as the first mating surface 6a, and the mating surface of sector 7 is designated as the second mating surface 7a. Of the tire forming surfaces 1b, the tire forming surface (tread forming surface) of sector 6 is designated as the first forming surface 6b, and the tire forming surface (tread forming surface) of sector 7 is designated as the second forming surface 7b.

[0063] The first fitting surface 6a is provided with a plurality of first recesses 61 having rubber inlet openings 611 on the tire forming surface 1b (first forming surface 6b). The first recesses 61 are arranged in parallel along the tire axial direction D1 (see Figure 8). The first recesses 61 are provided intermittently along the tire axial direction D1. By providing the first recesses 61 intermittently, the edges between the second fitting surface 7a and the second forming surface 7b are less prone to wear compared to when the first recesses 61 are provided continuously.

[0064] The first recess 61 is a groove that extends along the tire circumferential direction D3. The first recess 61 opens at one end to the first fitting surface 6a and terminates at the other end on the first forming surface 6b.

[0065] The outer end of the first recess 61 in the tire radial direction D2 is inclined outward in the tire radial direction D2 toward the first mating surface 6a. The depth H5 of the first recess 61 in the tire radial direction D2 increases toward the first mating surface 6a.

[0066] The depth H5 of the first recess 61 is preferably 0.3 mm or more. This allows the second recess 71 to be separated from the tire forming surface 1b. The depth H5 is preferably 2 mm or less. This allows the protrusion formed on the tread surface by the first recess 61 to be reduced.

[0067] The first mating surface 6a or the second mating surface 7a is provided with a second recess 71 that connects when at least two adjacent first recesses 61 are mated together. By providing the first recess 61 and the second recess 71, pinches can be formed that are intermittently connected to the tire. This makes the manual removal of pinches easier compared to the case where pinches that are continuously connected to the tire are removed by hand. As a result, pinches can be easily removed without using a turntable.

[0068] In this embodiment, the second recess 71 is provided on the second fitting surface 7a. This makes it easier for the pinch to disengage from the second recess 71 when the sector 7 is separated from the sector 6 in the tire circumferential direction D3. As a result, it is possible to suppress the pinch from being torn off when the sector 7 is separated.

[0069] The second recess 71 is a groove that extends along the tire axial direction D1 (along the second forming surface 7b) (see Figure 8). The width W7 of the second recess 71 in the tire radial direction D2 is preferably 2 mm or more. This makes it easier for the worker to grasp the pinch and facilitates the pinch cutting work. The width W7 is preferably 10 mm or less. This prevents a shortage of rubber for forming the pinch in the second recess 71.

[0070] The depth H6 of the second recess 71 along the tire circumferential direction D3 is preferably 1 mm or more. This ensures the strength of the pinch and prevents it from being torn apart at any point other than the connection between the projection formed by the first recess 61 and the pinch when the pinch is pulled. The depth H6 is preferably 10 mm or less. This prevents a shortage of rubber in the second recess 71 for forming the pinch.

[0071] The width W7 of the second recess 71 is preferably greater than the depth H6 of the second recess 71. This makes it easier for the worker to grasp the pinch and facilitates the pinch cutting process.

[0072] The distance L2 from the second forming surface 7b to the outer edge of the second recess 71 in the tire radial direction D2 is preferably 2.5 mm or more. This ensures that the width W7 of the second recess 71 is secured, making it easier for the worker to grasp the pinch and facilitating the pinch cutting operation. The distance L2 is preferably 20 mm or less. This prevents a shortage of rubber for forming the pinch in the second recess 71.

[0073] The width W7 of the second recess 71 is preferably 50% or more of the distance L2 to the outer edge of the second recess 71. This ensures that the width W7 of the second recess 71 is secured, making it easier for the worker to grasp the pinch and facilitating the pinch cutting operation. The width W7 is preferably 90% or less of the distance L2. This prevents a shortage of rubber for forming the pinch in the second recess 71.

[0074] As shown in Figure 8, the first recess 61 is formed wider toward the first forming surface 6b. In this embodiment, the first recess 61 is formed in a substantially triangular cross-section. The first recess 61 is formed wider toward the first fitting surface 6a. In this embodiment, the first recess 61 is formed in a substantially triangular shape when viewed in the tire radial direction D2. Note that the first recess 61 is not limited to the above.

[0075] The width W6 of the first recess 61 along the tire axial direction D1 is preferably 0.5 mm or more. This allows for good introduction of rubber into the first recess 61. It also prevents the projection formed by the first recess 61 from being torn off when the sectors 6 separate or when the pinch formed by the second recess 71 is torn off. The width W6 is preferably 5 mm or less. This prevents a shortage of rubber for forming the pinch in the second recess 71.

[0076] The spacing P4 of the first recess 61 is preferably 0.5 mm or more. This facilitates the pinch removal process. The spacing P4 is preferably 10 mm or less. This prevents pinches from forming in the gap between the mating surfaces of sector 6 and sector 7 where the first recess 61 is not provided.

[0077] The width W6 of the first recess 61 is preferably 30% or more of the installation interval P4 of the first recess 61. This prevents the formation of pinches in the gap between the first fitting surface 6a and the second fitting surface 7a (see Figure 7), where the first recess 61 is not provided. The width W6 is preferably 90% or less of the installation interval P4. This makes it easier to remove pinches.

[0078] In this embodiment, two second recesses 71 are provided in pairs. The pair of second recesses 71, 71 are formed symmetrically with respect to the tire equatorial plane S1 and are discontinuous. However, the second recesses 71 are not limited to the above, and the second recess 71 may be a single groove that extends continuously.

[0079] The width W8 of the connecting portion 8 along the tire axial direction D1 is preferably 0.2 mm or more. This allows for good introduction of rubber into the second recess 71. It also prevents the pinch from being torn off when the sectors 7 separate. The width W8 is preferably 3 mm or less. This allows for the formation of a pinch that is easy to cut, making the pinch cutting operation easier.

[0080] The thickness T2 of the connecting portion 8 in the tire radial direction D2 is preferably 0.1 mm or more. This prevents the pinch from being torn off when the sectors 7 separate. The thickness T2 is preferably 2 mm or less. This allows for the formation of a pinch that is easy to cut, making the pinch cutting operation easier.

[0081] The area of ​​the connecting part 8 is 0.01 mm². 2It is preferable that the above conditions are met. This prevents the pinch from being torn off when sector 7 separates. The area of ​​the connecting portion 8 is 4 mm². 2 The following is preferable. This allows the pinch to be torn off by the worker's hand, making the pinch removal process easier.

[0082] [Embodiment 4] Next, the tire molding die 1 according to Embodiment 4 will be described with reference to Figures 9 and 10. The tire molding die 1 according to Embodiment 4 is a combination of the tire molding die 1 according to Embodiment 1 and the tire molding die 1 according to Embodiment 3. Embodiment 4 shows an example where the first mold is the side mold 2 and the second mold is the sector 3. The same configuration as in Embodiment 1 will not be described.

[0083] Figure 9 is a longitudinal cross-sectional view of the tire molding die 1 according to Embodiment 4. As shown in Figure 9, of the mating surfaces of the sectors 3, the mating surface on one side of the sector 3 in the tire circumferential direction D3 is designated as the third mating surface 3c, and the mating surface on the other side of the sector 3 in the tire circumferential direction D3 is designated as the fourth mating surface 3d. The third mating surface 3c corresponds to the first mating surface 6a of Embodiment 3 (see Figures 7 and 8), and the fourth mating surface 3d corresponds to the second mating surface 7a of Embodiment 3 (see Figure 7).

[0084] Figure 10 is an enlarged view of region X in Figure 9. As shown in Figures 9 and 10, the third fitting surface 3c is provided with a plurality of third recesses 32 having rubber inlets 321 on the tire forming surface 1b (second forming surface 3b). The third recesses 32 correspond to the first recess 61 (see Figure 7) in Embodiment 3.

[0085] The third mating surface 3c or the fourth mating surface 3d is provided with a fourth recess 33 that connects when at least two adjacent third recesses 32 are mated. In this embodiment, two fourth recesses 33 are provided on the fourth mating surface 3d, but this is not limited to this. The fourth recess 33 corresponds to the second recess 71 in Embodiment 3 (see Figure 7). The connecting portion 5 between the third recess 32 and the fourth recess 33 (hatched portion in Figure 10) corresponds to the connecting portion 8 in Embodiment 3 (see Figure 8).

[0086] The fourth recess 33 extends to the second recess 31 and connects with the second recess 31 on the fourth fitting surface 3d. This allows the pinches formed on the side surface of the tire and the pinches formed on the tread surface to be connected, making the pinch removal work easier. In this embodiment, the pair of fourth recesses 33, 33 are each connected to different second recesses 31, but this is not limited to this.

[0087] Preferably, the fourth recess 33 connected to one of the second recesses 31 in the tire axial direction D1 is discontinuous with the fourth recess 33 connected to the other second recess 31. This allows the pinches on one side of the tire axial direction D1 to be cut separately from the pinches on the other side. As a result, the pinch cutting operation can be made easier compared to the case where the pinches on both sides of the tire axial direction D1 are connected.

[0088] [Tire manufacturing method] Next, a tire manufacturing method using the tire molding die 1 described above will be explained.

[0089] First, an unvulcanized tire is placed in the tire molding mold 1 and the mold is clamped. Next, the bladder is inflated to press the outer surface of the tire tread against the tread forming surface of the sector, and the outer surface of the sidewall against the tire forming surface of the side mold, and vulcanization molding is performed by heating and pressurizing at a predetermined vulcanization temperature. During this vulcanization molding, excess rubber from the tire flows into the first and second recesses, forming pinches.

[0090] After vulcanization molding is complete, the mold is opened and the tire is demolded. Then, the pinches of the demolded tire are grasped and cut off. In the above embodiment, the pinches can be torn off the tire, making it easy to remove them. Alternatively, tools such as cutting tools may be used to remove the pinches. After the pinches have been removed, intermittent (perforated) pinch removal marks are formed on the tire.

[0091] [1] As described above, the tire molding die 1 according to this embodiment comprises a first mold and a second mold that fits with the first mold, wherein the fitting surface of the first mold is designated as the first fitting surface and the fitting surface of the second mold is designated as the second fitting surface, the first fitting surface is provided with a plurality of first recesses having rubber introduction openings on the tire forming surface 1b, and the first fitting surface or the second fitting surface is provided with second recesses that connect when at least adjacent first recesses are fitted together.

[0092] With this configuration, by providing the first and second recesses, pinches can be formed that are intermittently connected to the tire 100. This makes it easier to tear off the pinches compared to manually cutting off pinches that are continuously connected to the tire 100, thus facilitating the manual cutting of pinches.

[0093] [2] Furthermore, in the tire molding die 1 according to [1] above, it is preferable that the first mold is a side mold 2 that forms the side surface of the tire 100, the first recess 21 is a groove that forms the ridge 105a of the serration 105 on the side surface of the tire 100, the second mold is a sector 3 that forms the tread surface of the tire 100, and the second recess 31 extends along the tire circumferential direction D3.

[0094] With this configuration, by forming pinches on the serrations 105, the pinch marks caused by the removal of the pinches can be made less noticeable. Furthermore, by using the grooves that form the ridges 105a as the first recesses 21, the processing cost for forming the first recesses 21 can be reduced.

[0095] [3] Furthermore, in the tire molding die 1 according to [1] above, it is preferable that the first recess is formed to be narrow in width toward the tire forming surface 1b.

[0096] With this configuration, a pinch can be formed where the width of the connection part with the tire 100 is smaller than the width of other parts. This makes it possible to cut off the pinch at the connection part with the tire 100.

[0097] [4] Furthermore, in the tire molding die 1 according to [1] above, it is preferable that the first die and the second die are sectors 6 and 7 that form the tread surface of the tire 100, the first recess 61 extends along the tire circumferential direction D3, and the second recess 71 extends along the tire axial direction D1.

[0098] With this configuration, pinches formed on the tread surface of the tire 100 can be easily removed.

[0099] [5] Furthermore, in a tire molding die 1 relating to any one of the above [1] to [3], the first die is a side mold 2 that forms the side surface of the tire 100, and the second die is a sector 3 that forms the tread surface of the tire 100, and when one fitting surface of the second die (sector 3) in the tire circumferential direction D3 is designated as the third fitting surface 3c, and the other fitting surface of the second die (sector 3) in the tire circumferential direction D3 is designated as the fourth fitting surface 3d, the third fitting surface 3c is provided with a plurality of third recesses 32 having a rubber inlet 321 on the tread forming surface (second forming surface 3b), and the third fitting surface 3c or the fourth fitting surface 3d is provided with a fourth recess 33 that connects when at least adjacent third recesses 32 are fitted together, and the fourth recess 33 is connected to the second recess 31 when at least fitted together.

[0100] With this configuration, the pinches formed on the side surface of the tire 100 and the pinches formed on the tread surface can be connected. This makes it possible to cut off the pinches, for example, by tearing them off, and to cut off the pinches on both the side surface and the tread surface of the tire 100 simultaneously, thus facilitating the pinch removal process.

[0101] [6] Furthermore, a preferred method for manufacturing the tire 100 according to this embodiment includes a step of setting an unvulcanized tire in any one of the tire molds 1 described in [1] to [5] above, and then heating and pressurizing the unvulcanized tire to perform vulcanization molding.

[0102] This method allows for the formation of intermittently connected pinches on the tire 100. This makes the manual removal of pinches easier compared to the case where continuously connected pinches on the tire 100 are removed by hand.

[0103] Furthermore, the manufacturing method of the tire mold 1 and the tire 100 is not limited to the configurations and methods of the embodiments 1 to 4 described above, nor is it limited to the effects described above. Also, the manufacturing method of the tire mold 1 and the tire 100 can be modified in various ways without departing from the spirit of the present invention. For example, one or more configurations and methods from any of the embodiments 1 to 4 described above may be arbitrarily selected and adopted in the configurations and methods of the other embodiments 1 to 4. Also, one or more configurations and methods from the various modification examples described below may be arbitrarily selected and adopted in the configurations and methods of the embodiments 1 to 4 described above.

[0104] (A) In Embodiment 3, the first recess 61 is formed to be wider toward the first forming surface 6b, but the invention is not limited to this configuration. For example, the first recess 61 may be formed to be narrower toward the first forming surface 6b (narrower toward the inside of the tire axial direction D1), as shown in Figure 11. With such a configuration, the protrusion formed by the first recess 61 can be made into a pinch, and by cutting off the pinch, the formation of a protrusion on the tread surface can be suppressed.

[0105] In this configuration, the width, depth, and area of ​​the rubber inlet 611 of the first recess 61 are the same as those of the rubber inlet 211 of the first recess 21 in Embodiment 2 (see Figures 4 and 5). The area of ​​the first recess 61 is smaller than the area of ​​the connecting portion 8 between the first recess 61 and the second recess 71.

[0106] (B) In Embodiment 3, as shown in Figure 12, a first recess 61 may be provided on the projection 62 of sector 6 that forms the main groove on the tread surface, and a second recess 71 may be provided on the projection of sector 7 (see Figure 7) that forms the main groove on the tread surface. With such a configuration, pinches formed in the main groove of the tire can also be easily removed.

[0107] (C) In Embodiment 3, as shown in Figure 13, sector 6 may be provided with grooves 63 that form protrusions on the tread surface, sector 7 (see Figure 7) may be provided with grooves that form protrusions on the tread surface together with grooves 63, a first recess 61 may be provided around the grooves 63 of sector 6, and a second recess 71 may be provided around the grooves of sector 7. With such a configuration, pinches formed on the protrusions on the tread surface can be easily removed. [Explanation of Symbols]

[0108] 1...Tire molding die, 1b...Tire forming surface, 2...Side mold, 2a...First mating surface, 2b...First forming surface, 21...First recess, 211...Rubber inlet, 3,6,7...Sector, 3a,7a...Second mating surface, 3b,7b...Second forming surface, 3c...Third mating surface, 3d...Fourth mating surface, 31...Second recess, 311...Rubber inlet, 32...Third recess, 321...Rubber inlet, 33...Fourth recess, 6a...First mating surface, 6b...First forming surface, 61...First recess, 611...Rubber inlet, 71...Second recess, 4,5,8...Connecting part, 100...Tire, 101...Bead part, 102...Sidewall, 103...Tread, 104...Decorative area, 105...Serration, 105a...Ridge, 106...Split position

Claims

1. It comprises a first type and a second type that fits with the first type, When the mating surface of the first type is designated as the first mating surface and the mating surface of the second type is designated as the second mating surface, The first fitting surface is provided with a plurality of first recesses having rubber inlet openings on the tire forming surface. The first fitting surface or the second fitting surface is provided with a second recess that connects adjacent first recesses when they are fitted together. The first type is a side mold that forms the side surface of the tire, The second type is a sector that forms the tread surface of the tire, When the fitting surface on one side of the tire in the circumferential direction of the second type is designated as the third fitting surface, and the fitting surface on the other side of the tire in the circumferential direction of the second type is designated as the fourth fitting surface, The third fitting surface is provided with a plurality of third recesses having rubber inlet openings on the tread forming surface, The third fitting surface or the fourth fitting surface is provided with a fourth recess that connects adjacent third recesses when at least two of them are fitted together. The fourth recess connects with the second recess when fitted, in a tire molding die.

2. The first recess is a groove that forms a serrated ridge on the side surface of the tire, The tire molding die according to claim 1, wherein the second recess extends along the circumferential direction of the tire.

3. The tire molding die according to claim 1, wherein the first recess is formed to be narrow in width toward the tire forming surface.

4. A method for manufacturing a tire, comprising the step of setting an unvulcanized tire in a tire molding die according to any one of claims 1 to 3, and performing vulcanization molding by heating and pressurizing the unvulcanized tire.

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