Segmented mold for tire vulcanization

Abstract

The utility model discloses a segmented mold for tire vulcanization, which comprises a pattern block, and the pattern block is provided with a first parting surface overlapped with the arc-shaped surface of a tire blank; and the upper side plate or the lower side plate is provided with a second parting surface coinciding with the arc-shaped surface of the tire blank, the second parting surface, the first parting surface and the arc-shaped surface of the tire blank define a parting bulge, and the radial cross section of the parting bulge is a triangle defined by two arc lines and a straight line. According to the utility model, the pattern block is arranged, and the upper side plate or the lower side plate is respectively intersected with the tire blank to form the first parting surface and the second parting surface, so that air in the cavity can be gathered in a gap between the pattern block and the upper side plate or the lower side plate along the first parting surface and the second parting surface to be discharged; and meanwhile, the first parting surface, the second parting surface and the tire blank define a parting bulge, and the parting bulge can accommodate redundant rubber materials to avoid overflowing, so that the appearance quality of the tire is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to tire production technical field, concretely relates to a kind of for tire vulcanization to be moulded. BACKGROUND

[0002] Tire vulcanization is the key step in tire manufacturing, which makes rubber molecules crosslink by high temperature and high pressure, gives tire strength, elasticity and durability, it is to be unmoulded into tire vulcanization mould for vulcanization, tire vulcanization mould is the key tool in tire manufacturing, for unmoulded rubber tire blank is shaped under high temperature and high pressure and is given its final pattern, size and structure, it includes two half moulds, moulded and capsule mould, wherein moulded is composed of multiple radial movable pattern blocks, upper and lower side plates and guide rings.Pattern block, upper and lower side plate and the installation position of tire are as shown in Figure 3 Contact area of pattern block, side plate and tire surface forms parting surface, and tire forms protruding parting protrusion, so that more rubber compound in tire blank than the volume of internal cavity of vulcanization mould enters parting protrusion during vulcanization process, avoid rubber compound overflow through the gap between pattern block and side plate to cause tire flash, affect its appearance quality, and cavity internal air is discharged through mould gap, i.e. exhaust passage, to avoid air trapped in mould to form the quality of vulcanized tire.

[0003] The present inventor found that existing parting surface mainly includes two shapes as shown in Figure 4 And Figure 5 Wherein, parting surface without parting protrusion in the same plane design cannot accommodate excess rubber compound to cause overflow and further cause tire flash, and parting surface with stepped shape design has sudden spatial change, so that rubber compound cannot fill the parting protrusion, causing overflow, and the parting surface of this design lacks air flow channel, so that air in cavity flows poorly. CONTENT OF UTILITY MODEL

[0004] The utility model discloses a moulded for solving the problem that the parting surface of existing moulded influences tire blank vulcanization effect, and provides a kind of moulded for tire vulcanization, and specific technical solutions are as follows:

[0005] Moulded forms cavity for vulcanization tire blank, and moulded includes: pattern block, the pattern block has the first parting surface coinciding with the arc surface of tire blank;And upper side plate or lower side plate, the upper side plate or lower side plate has the second parting surface coinciding with the arc surface of tire blank, the second parting surface, first parting surface and the arc surface of tire blank enclose parting protrusion, and the radial section of parting protrusion is the triangle enclosed by two arcs and a straight line.

[0006] Further, the first parting surface is an arc-shaped surface protruding towards the tire blank, a radius R1 of the arc-shaped surface satisfies 2mm≦R1≦8mm, one end of the first parting surface is tangent to the arc-shaped surface of the tire blank, and the other end of the first parting surface intersects the second parting surface.

[0007] Preferably, the second parting surface is a plane, the plane intersects the first parting surface and the arc-shaped surface of the tire blank respectively, an included angle between a tangent at the intersection point of the tire blank and the second parting surface is α, 166°≦α≦176°, and an intersection position of the first parting surface and the second parting surface is a connecting position of the pattern block and the upper side plate or the lower side plate.

[0008] Preferably, a gap exists between the connecting surfaces of the pattern block and the upper side plate or the lower side plate opposite to each other, the gap is an exhaust passage, and the exhaust passage is in communication with the tire blank and the outside.

[0009] Preferably, a vertical distance of the intersection position of the first parting surface and the second parting surface to the tangent of the arc-shaped surface of the tire blank is H, and 0.5mm≦H≦1mm.

[0010] Preferably, the intersection position of the second parting surface and the arc-shaped surface of the tire blank forms a fillet, a radius R2 of the fillet satisfies 0.3mm≦R2≦0.8mm.

[0011] According to the technical scheme, the utility model has the following beneficial effects:

[0012] The utility model discloses a pattern block, upper side plate or lower side plate respectively with tire blank intersection forms first parting surface and second parting surface, so that the air in the cavity can gather in the gap between the pattern block and the upper side plate or the lower side plate along the first parting surface and the second parting surface and is discharged, and the first parting surface, the second parting surface and the tire blank form a parting protrusion, the parting protrusion can accommodate the excess rubber to avoid overflow, and the appearance quality of the tire is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is radial section view of the utility model embodiment two;

[0014] Figure 2 It is Figure 1 structure enlarged view of A of the utility model embodiment;

[0015] Figure 3 It is prior tire vulcanization flexible die schematic view;

[0016] Figure 4 It is a flexible die parting surface schematic view;

[0017] Figure 5 It is a flexible die parting surface schematic view.

[0018] In the figure: 1, tire blank; 2, pattern block; 3, upper side plate; 4, lower side plate; 5, parting protrusion; 6, exhaust passage. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be apparently and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all the other embodiments obtained by the ordinary skilled in the art without creative labor belong to the scope of protection of the utility model.

[0020] In the description of the embodiments of the utility model, it should be explained that the directions or position relations indicated by the terms "inner", "outer", "upper" and the like are based on the directions or position relations shown in the drawings or the directions or position relations of the utility model product in common use, which are only for the convenience of describing the utility model and simplifying the description, and thus cannot be understood as the limitation on the utility model that the indicated devices or elements must have the specific directions, be constructed and operated in the specific directions.

[0021] As shown in Figure 1 and Figure 3 , the embodiment forms a cavity for vulcanizing the tire blank, which is the key to ensure the final shape, pattern and performance of the tire. The embodiment includes pattern blocks uniformly installed on the radial surface of the tire blank in the circumferential direction, and the upper side plate and the lower side plate are respectively installed at both ends of the pattern blocks. In the figure, the upper side plate is installed on the left axial side of the tire blank, and the lower side plate is installed on the right axial side of the tire blank. The inner surfaces of the pattern blocks, the upper side plate and the lower side plate form a cavity for placing the tire blank. The tire blank will soften itself during the vulcanization process, flow in the cavity and fill the entire cavity to form a vulcanized tire. At the same time, the tire blank will extrude air to the gap between the pattern blocks and the upper side plate and the lower side plate during the flow process. At the same time, the air flow direction is also the self-flow direction, so that the contact area of the pattern blocks and the upper side plate and the lower side plate forms a parting surface.

[0022] As shown in Figure 1 and Figure 2 , the embodiment includes: a pattern block 2 having a first parting surface coinciding with the arc surface of the tire blank 1; and an upper side plate 3 or a lower side plate 4 having a second parting surface coinciding with the arc surface of the tire blank 1. The second parting surface, the first parting surface and the arc surface of the tire blank 1 form a parting protrusion 5, and the radial section of the parting protrusion 5 is a triangle surrounded by two arcs and a straight line.

[0023] Specifically, the upper part of the pattern block 2 is attached to the curved surface of the tire blank 1, the lower part is away from the curved surface of the tire blank 1, and the lower part close to the inner surface of the tire blank 1 is the first parting surface, Figure 2 The lower part of the upper side plate 3 in the above is attached to the curved surface of the tire blank 1, the upper part is away from the curved surface of the tire blank 1, and the upper part close to the inner surface of the tire blank 1 is the second parting surface. The first parting surface intersects the curved surface of the tire blank 1, the first parting surface intersects the second parting surface, the second parting surface intersects the curved surface of the tire blank 1, and the three intersections form a triangular parting protrusion 5. In the radial section of the parting protrusion 5, one of the arcs of the triangle is the radial section of the curved surface of the tire blank 1, the other arc and the straight line are the radial sections of the first parting surface and the second parting surface, respectively. Considering that the radius of curvature of the inner surface radial section of the pattern block 2 is smaller than that of the inner surface radial section of the upper side plate 3 during production, the first parting surface radial section is set as an arc, and the second parting surface radial section is a straight line, which reduces the stress concentration at the intersection position and avoids the stress concentration at the intersection position of the parting protrusion 5 and the tire blank 1 caused by setting the first parting surface radial section as a straight line, which is easy to cause cracking, affects the performance of the tire, and even affects the driving safety.

[0024] Secondly, the tire blank 1 is softened to form flowing rubber during vulcanization, and the tire blank 1 is continuously pressed to fit the cavity during vulcanization, so that the excess flowing rubber flows to the first parting surface and the second parting surface. The upper end curve of the parting protrusion 5 can smoothly flow to the gap along the flowing rubber, and the lower end straight line of the parting protrusion 5 can accommodate more rubber than the upper end curve, so that the excess rubber can be stored at the lower end of the parting protrusion 5, reducing the overflow caused by the parting protrusion 5 failing to accommodate excess rubber, which flows to the gap, forming the flash of the tire, and affecting the appearance quality.

[0025] Secondly, the intersection position of the first parting surface radial section and the second parting surface radial section is the vertex of the triangle, the air in the cavity can converge at the vertex along the radial sections of the two, and the vertex is located at the gap between the pattern block 2 and the upper side plate 3, so that the first parting surface and the second parting surface can guide the air in the cavity to flow out from the gap, avoiding the air being closed in the cavity by the tire blank 1 to cause the tire pores, affecting the quality of the tire, and at the same time, the smooth flowing path of the rubber is avoided; At the same time, the first parting surface and the second parting surface are both smooth surfaces, so that the pattern block 2 and the upper side plate 3 can be smoothly separated from the tire blank 1 during demolding, avoiding the increase of demolding difficulty caused by the non-smooth surface; Secondly, the parting protrusion 5 is a triangle, which has a regular shape and does not affect the appearance quality of the tire.

[0026] As shown in Figure 2 The first parting surface is an arc-shaped curved surface protruding towards the tire blank 1, the radius R1 of the arc-shaped curved surface satisfies 2mm≦R1≦8mm, one end of the first parting surface is tangent to the curved surface of the tire blank 1, and the other end of the first parting surface intersects the second parting surface.

[0027] Specifically, the center of the radial section of the first parting surface is away from the embryo 1, which forms a smooth path to guide the flow of rubber, and the upper end is tangent to the arc surface of the embryo 1, so that the flowing rubber formed by melting the embryo 1 can flow along the first parting surface to the parting protrusion 5, and the upper end face of the parting protrusion 5 is a smooth curved surface, reducing the stress concentration at the upper end of the parting protrusion 5, reducing the risk of cracks at this point, and improving the service life of the tire; wherein the radius of the radial section of the first parting surface is R1, when R1<2mm, the distance from the first parting surface to the gap between the pattern block 2 and the upper side plate 3 is too short, which increases the resistance of the rubber flowing along the first parting surface to the gap, so that the rubber flow is insufficient, causing the parting protrusion 5 to be short of rubber, affecting the appearance quality of the tire; when R1>8mm, the cross-sectional area of the upper half of the parting protrusion 5 is too large due to the large size of the cross-sectional radius of the first parting surface, which affects the appearance quality of the tire, and increases the wind resistance and rolling resistance of the tire.

[0028] Wherein the other end of the first parting surface intersects with the second parting surface at the gap, so that the rubber can flow along the smooth first parting surface to the gap, improving the vulcanization efficiency and molding quality of the embryo 1.

[0029] Further, the second parting surface is a plane, which intersects with the first parting surface and the arc surface of the embryo 1 respectively, and the included angle between the tangent line at the intersection point of the embryo 1 and the second parting surface is ɑ, 166°≦ɑ≦176°, and the intersection position of the first parting surface and the second parting surface is the connection position of the pattern block 2 and the upper side plate 3 or the lower side plate 4.

[0030] Specifically, the radial section of the second parting surface is a straight line, which intersects with the radial section of the first parting surface at the gap for exhaust, and the other end of the straight line intersects with the embryo 1, wherein the included angle between the tangent line at the intersection position of the embryo 1 and the straight line is ɑ, when ɑ<166°, the angle between the straight line and the tangent line is too small, which makes the change of the second parting surface compared to the arc surface of the embryo 1 too large, causing stress concentration of the parting protrusion 5 at the intersection position of the second parting surface and the embryo 1, so that the tire is prone to crack at this point; when ɑ>176°, the cross-sectional area of the lower end of the parting protrusion 5 is too large, which increases the wind resistance of the parting protrusion 5 and the rolling resistance of the tire, and at the same time, the excessive volume of the parting protrusion 5 makes it difficult to completely fill the excess rubber, causing the parting protrusion 5 to be short of rubber, reducing the appearance quality of the tire.

[0031] Further, there is a gap between the opposite connection surfaces of the pattern block 2 and the upper side plate 3 or the lower side plate 4, which is an exhaust passage 6, and the exhaust passage 6 communicates with the embryo 1 and the outside.

[0032] Specifically, the tire blank 1 forms flowing rubber during vulcanization, which extrudes air when flowing in the cavity, the flow path of the air is along the first parting surface and the second parting surface to the gap, the air flows to the outside through the exhaust channel 6, so that the cavity forms a vacuum environment, ensuring the quality of the tire after vulcanization.

[0033] Further, the perpendicular distance between the intersection position of the first parting surface and the second parting surface and the tangent of the arc surface of the tire blank 1 is H, 0.5mm≦H≦1mm.

[0034] Specifically, the first parting surface section and the second parting surface section intersect at the vertex of the parting protrusion 5, and the minimum distance from the vertex to the tire blank 1 is H. When H<0.5mm, the volume of the parting protrusion 5 is too small to accommodate the excess rubber formed during vulcanization of the tire blank 1, causing the excess rubber to flow to the gap and causing overflow, forming tire flash and affecting the appearance quality of the tire. When H>1mm, the volume of the parting protrusion 5 is too large, and its radial cross-sectional area is too large, increasing its wind resistance and increasing the rolling resistance of the tire.

[0035] Further, the intersection position of the second parting surface and the arc surface of the tire blank 1 forms a fillet, and the radius R2 of the fillet satisfies 0.3mm≦R2≦0.8mm.

[0036] Specifically, the radial section of the second parting surface is a straight line, and the fillet formed at the intersection position of the straight line and the arc surface of the tire blank 1 can reduce the stress concentration of the parting protrusion 5 at this position. When R2<0.3mm, the transition at the lower end intersection position of the parting protrusion 5 is too large, causing stress concentration at this position, which in turn causes the tire to be prone to cracking at this position. When R2>0.8mm, the length of the straight edge of the parting protrusion 5 is too small, causing the volume of the lower end of the parting protrusion 5 to be too small to accommodate excess rubber, causing the rubber to overflow from the gap and form tire flash, affecting the appearance quality of the tire.

[0037] Experimental verification

[0038] 200 pneumatic radial tires (size: 215 / 55R47) were manufactured by vulcanization using the ordinary parting surface split mold as a comparative example and the tire blank of the present embodiment, respectively, and the results are as follows:

[0039] Scheme Tire classification defect rate Comparative Example 10％ Example 1％

[0040] As shown in the above table, the parting defect rate of the tire manufactured by vulcanization using the present embodiment is reduced from 10% to 1%, greatly improving the appearance quality of the tire.

[0041] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

[0042] The technical, shape, and structure parts not described in detail in the present application are well-known technologies.

Claims

1. A movable mold for tire vulcanization, the movable mold forming a cavity for vulcanizing a tire blank (1), characterized in that, The movable mold includes: Pattern block (2), the pattern block (2) having a first parting surface that coincides with the arcuate surface of the embryo (1); and The upper side plate (3) or the lower side plate (4) has a second parting surface that coincides with the arcuate surface of the tire blank (1). The second parting surface, the first parting surface and the arcuate surface of the tire blank (1) form a parting protrusion (5). The radial cross section of the parting protrusion (5) is a triangle formed by two arcs and a straight line.

2. The movable mold according to claim 1, characterized in that: The first parting surface is an arc-shaped surface that protrudes towards the embryo (1). The radius R1 of the arc-shaped surface satisfies 2mm≦R1≦8mm. One end of the first parting surface is tangent to the arc-shaped surface of the embryo (1), and the other end of the first parting surface intersects with the second parting surface.

3. The movable mold according to claim 2, characterized in that: The second parting surface is a plane, which intersects the first parting surface and the arc surface of the embryo (1) respectively. The angle between the tangent of the intersection point of the embryo (1) and the second parting surface is α, 166°≦α≦176°. The intersection position of the first parting surface and the second parting surface is the connection position of the pattern block (2) and the upper side plate (3) or the lower side plate (4).

4. The movable mold according to claim 3, characterized in that: There is a gap between the patterned block (2) and the connecting surface opposite to the upper side plate (3) or the lower side plate (4). This gap is an exhaust channel (6), which is connected to the tire blank (1) and the outside world.

5. The movable mold according to claim 3, characterized in that: The perpendicular distance between the intersection of the first parting surface and the second parting surface and the tangent of the arc-shaped surface of the embryo (1) is H, 0.5mm≦H≦1mm.

6. The movable mold according to claim 3, characterized in that: The intersection of the second parting surface and the arc-shaped surface of the embryo (1) forms a rounded corner, and the radius of the rounded corner R2 satisfies 0.3mm≦R2≦0.8mm.

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