A mold for foamed PU tire

Abstract

The utility model relates to the technical field of tire manufacturing, and specifically to a mold for a foamed PU tire. In the solution of the present application, a plurality of exhaust ports are provided on the step, and a recessed portion is provided between adjacent exhaust ports to extend to the edge of the exhaust port. Since the space of the step is limited, the width of the foaming feed port is greatly increased by extending the recessed portion to the edge of the exhaust port. The wider the feed port, the lower the melt injection speed, and the smaller the impact force on the inner wall. A plurality of wide annular foaming feed ports are formed, so that the high-speed injected melt material is first decelerated and diffused before entering the foaming cavity, and the flow area is greatly increased, thereby greatly reducing the impact force on the inner cavity wall. This not only reduces defects such as rotational streaks, but also improves the quality of the inner surface.

Description

Technical Field

[0001] The utility model relates to the technical field of tire manufacturing, in particular to a mold for a foamed PU tire. Background Art

[0002] In the tire manufacturing industry, foamed PU (polyurethane) tires are widely used due to their wear resistance, anti-aging, tear resistance and other properties. However, in the traditional production process of foamed PU tires, we found that the mold design with a single middle feed port and three-path feeding through mold rotation has some significant defects.

[0003] Specifically, the surface of tires produced by this traditional design often has streaks, which seriously affects the appearance and quality of the products. The formation of such streaks is mainly due to the fact that the mold is rotating during rotation, such as Figure 1 As shown, the feed port 300 of this type of mold is designed to be narrow, and the material is easily hit against the inner wall of the mold when it is quickly injected, and then splashes back, thereby forming rotating streaks on the tire surface. In addition, after the material enters the mold, due to the high internal pressure, the impact force is strong, and the internal gas is difficult to be discharged in time, which also leads to the formation of streaks. These problems are particularly obvious when producing high-speed rotating tires. The rotating streaks on the product surface seriously affect the product's aesthetics and market acceptance. Utility Model Content

[0004] In order to solve the above problems, the utility model discloses a mold for a foamed PU tire.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions: a mold for a foamed PU tire, comprising a mold body, wherein the middle of the mold body has a central feed port, a circle of foaming cavities and a circle of steps are concentrically arranged around the central feed port in the mold body, the steps are located between the foaming cavity and the central feed port, and a plurality of exhaust ports are opened on the steps, recessed portions are arranged on the steps corresponding to adjacent exhaust ports, and the ends of the recessed portions extend to the edges of the exhaust ports, thereby forming a foaming feed port connecting the central feed port and the foaming cavity.

[0006] In the above solution, a circle of guiding inclined surfaces is provided on one side of the central feed opening close to the step, and one side edge of the guiding inclined surfaces extends to the step.

[0007] In addition, a partition strip is protrudingly provided on the edge of one side of the foaming feed port close to the foaming cavity.

[0008] A guiding slope is arranged on one side of the dividing strip facing the central feed opening.

[0009] Furthermore, the partition strips are arranged at intervals on the edge of the foaming feed opening, thereby forming a plurality of gaps at the edge of the foaming feed opening.

[0010] The solution of the embodiment of the present application is to open multiple exhaust ports on the step and provide a recessed portion between adjacent exhaust ports extending to the edge of the exhaust port. Due to the limited space of the step, the width of the foaming feed port is greatly increased by extending the recessed portion to the edge of the exhaust port. The wider the feed port, the lower the melt injection speed and the smaller the impact force on the inner wall. Multiple wide annular foaming feed ports are formed, so that the high-speed injected melt material is first decelerated and diffused before entering the foaming cavity, and the flow area is greatly increased, thereby greatly reducing the impact force on the inner cavity wall. This not only reduces defects such as rotation streaks, but also improves the quality of the inner surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the structure of a mold in an embodiment of the present application;

[0012] Figure 2 Schematic diagram of the overall structure of the foamed PU tire mold in Example 1 of the present application;

[0013] Figure 3 This is a schematic diagram of the position of the guide slope in the embodiment of the present application;

[0014] Figure 4 It is a cross-sectional view of the foamed PU tire mold in Example 1 of the present application;

[0015] Figure 5 for Figure 3 A partial enlarged view of the middle A;

[0016] Figure 6 Schematic diagram of the structure of the separator in the embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings.

[0018] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be used as limitations on the present invention. As used in the specification and appended claims of the present invention, the singular expressions "a", "an", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context.

[0019] References to "one embodiment" or "some embodiments" etc. described in this specification mean that one or more embodiments of the utility model include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0020] Example 1: Figure 2-4 As shown, a mold for a foamed PU tire includes a mold body 100, wherein the middle of the mold body 100 has a central feed port 101, wherein a circle of foaming cavities 102 and a circle of steps 103 are concentrically arranged around the central feed port 101 in the mold body 100, wherein the steps 103 are located between the foaming cavities 102 and the central feed port 101, and wherein a plurality of exhaust ports 131 are provided on the steps 103, wherein recessed portions are provided between adjacent exhaust ports 131 on the steps 103, and the ends of the recessed portions extend to the edges of the exhaust ports 131, thereby forming a foaming feed port 200 connecting the central feed port 101 and the foaming cavity 102.

[0021] A plurality of exhaust ports 131 are provided on the step 103, and a recessed portion is provided between adjacent exhaust ports and extends to the edge of the exhaust ports. A foaming feed port 200 is formed to connect the central feed port and the foaming cavity. The foaming feed port is distributed in an annular shape and has a large width (similar to the width of the foaming cavity). Figure 1 Compared with the feed port 300 shown in FIG, it helps the material to enter the foaming cavity evenly at a lower speed and a larger flow area.

[0022] The end of the foaming feed port 200 extends to the exhaust port 131, utilizing the limited step space and maximizing the feed port width. A larger feed port width means a lower injection speed and impact force.

[0023] Through the improvement of the foaming feed port 200, the high-speed ejected melt material is first decelerated and diffused and the flow area is increased before entering the foaming cavity, thereby greatly reducing the impact force of the material on the inner wall of the cavity. This not only reduces the generation of rotational patterns, but also helps to obtain good inner surface quality.

[0024] In a possible implementation, a circle of guiding bevels 111 is provided on one side of the central feed port 101 close to the step 103, and one side edge of the guiding bevel 111 extends to the step 103. The guiding bevel 111 guides the high-speed ejected material in the direction of the step 103, making the material streamline transition smoother and reducing the shear and turbulence generated when the material is turned.

[0025] One side edge of the guide slope 111 extends to the step 103, so that the material naturally transitions from the slope to the step 103, avoiding the formation of dead corners and blocking areas.

[0026] Example 2: Figure 2-6 As shown, a partition strip 121 is provided on the edge of the foaming feed port 200 near the foaming cavity 102. Since the material flow rate at the feed port is relatively low, some incompletely filled materials will remain there after molding. The provision of the partition strip 121 will cause the residual materials to form a partial depression at the edge, thereby facilitating separation from the tire body.

[0027] The side of the partition bar 121 facing the central feed inlet 101 is provided with a guiding slope 122. The side of the partition bar 121 facing the central feed inlet 101 is provided with a guiding slope 122. The slope structure can make the flowing material flow smoothly through the partition bar.

[0028] The partition strips 121 are arranged at intervals on the edge of the foaming feed opening 200, so as to form a plurality of gaps at the edge of the foaming feed opening 200, so as to reduce the blocking effect when feeding the material.

[0029] The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims

1. A mold for a foamed PU tire, comprising a mold body (100), wherein the middle of the mold body (100) is provided with a central feed port (101), wherein a circle of foaming cavities (102) and a circle of steps (103) are concentrically arranged around the central feed port (101) in the mold body (100), wherein the steps (103) are located between the foaming cavities (102) and the central feed port (101), and wherein a plurality of exhaust ports (131) are provided on the steps (103), wherein: A recessed portion is provided on the step (103) corresponding to adjacent exhaust ports (131), and an end of the recessed portion extends to the edge of the exhaust port (131), thereby forming a foaming feed port (200) connecting the central feed port (101) and the foaming cavity (102).

2. A mold for a foamed PU tire as claimed in claim 1, characterized in that: A circle of guiding inclined surfaces (111) is provided on one side of the central feed opening (101) close to the step (103), and one side edge of the guiding inclined surfaces (111) extends to the step (103).

3. A mold for a foamed PU tire as claimed in claim 1 or 2, characterized in that: A partition strip (121) is protrudingly provided on the edge of one side of the foaming feed port (200) close to the foaming cavity (102).

4. A mold for a foamed PU tire as claimed in claim 3, characterized in that: A guiding slope (122) is provided on one side of the dividing strip (121) facing the central feed opening (101).

5. A mold for a foamed PU tire as claimed in claim 3, characterized in that: The partition strips (121) are arranged at intervals on the edge of the foaming feed opening (200), thereby forming a plurality of gaps at the edge of the foaming feed opening (200).

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