Exhaust plug for tire mold

Abstract

This utility model discloses an venting plug for tire molds, belonging to the field of tire vulcanization mold technology. It includes a plug body with a venting channel, which comprises a gradient section, a throat, and an enlarged section connected sequentially. The gradient section includes two transition surfaces, the distance between which gradually decreases in the direction away from the mold cavity. The throat is the narrowest point of the two transition surfaces, forming a gap with a width approaching zero. The cross-sectional area of ​​the enlarged section gradually increases in the direction away from the mold cavity. The width of the gradient section gradually narrows in the direction away from the mold cavity, gradually increasing the resistance as the rubber material moves towards the throat, reducing rubber material overflow. When the rubber material overflows into the enlarged section, the pressure drops instantaneously, causing it to rapidly expand into an enlarged section. During demolding, the enlarged section breaks off from the throat and remains in the enlarged section, which can be easily removed during the cleaning cycle. This improves product yield, has a simple structure, is not easily damaged, and greatly reduces the difficulty of tire mold maintenance.

Description

Technical Field

[0001] This utility model relates to the field of tire vulcanization mold technology, specifically to a vent plug for tire molds. Background Technology

[0002] Vent plugs or vent sleeves are small venting components on tire molds, primarily used to expel air between the rubber or product surface and the mold. Traditional vent sleeves are tubular structures with an outer diameter of Φ2-4mm and an inner diameter of Φ0.6-1.6mm, relying on the diameter of the inner orifice for venting. A problem is that during venting, rubber material overflows and flows into the inner orifice, forming rubber fibers that affect the tire's appearance and waste raw materials. If these fibers break, they can remain inside the vent, clogging it and causing defects in subsequent vulcanization processes. One solution is to add a core inside the vent sleeve, containing a spring, forming an elastic component. During vulcanization, when the rubber material is not in contact with the core, the vent is open for venting. When the rubber material contacts and presses against the core, the core descends, closing the vent and achieving air permeability without leakage. However, this type of spring-loaded vent sleeve is small and delicate, making it prone to damage and posing significant challenges to maintenance.

[0003] Another type of poreless mold works by disassembling the tire mold cavity into many small units (commonly known as tread blocks), processing them, and then assembling them together. Air is released by utilizing the gaps between the units. A typical tire tread block mold cavity consists of 8-10 units (tread blocks), while a tread block mold has dozens to hundreds of units. It requires high precision and has high demands in processing, assembly, and maintenance. Furthermore, poreless molds are more expensive.

[0004] Traditional micropore or slit vent plugs utilize numerous tiny holes or slits for venting and employ their microstructure to prevent rubber material from overflowing. However, the molecular size of rubber material is far smaller than the maximum capabilities achievable by current machining processes. Even the smallest holes or slits will allow rubber material to seep in, leading to clogging problems. Furthermore, because the venting channels of micropore or slit vent plugs are extremely narrow, clogging them presents cleaning challenges. This limits the widespread application and adoption of existing microstructure vent plugs in tire molds.

[0005] Therefore, developing and designing an exhaust plug that is simple in structure, not easily damaged, greatly reduces the difficulty of maintenance, is inexpensive, and improves product yield is an urgent problem to be solved at this stage. Summary of the Invention

[0006] To address the problems existing in the prior art, this utility model provides a vent plug for tire molds. The width of the gradient section gradually narrows away from the cavity, causing the resistance to the rubber material in the cavity to gradually increase as it enters the gradient section and moves towards the throat, minimizing rubber material overflow. Furthermore, when the rubber material overflows from the throat and reaches the enlarged section, the pressure on the rubber material drops instantly, causing the rubber material in the enlarged section to rapidly expand and form an enlarged section. When the rubber product is demolded, the enlarged section breaks off at the throat and remains at the enlarged section, which can be easily and quickly removed during the cleaning cycle. Compared with traditional vent sleeves, this utility model improves product yield, leaves less rubber hair on the surface of the rubber product, enhances aesthetics, and reduces rubber waste. At the same time, the structure is simple, not easily damaged, greatly reducing the difficulty of tire mold maintenance, and is cost-effective.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a vent plug for a tire mold, wherein the tire mold has a cavity inside and a vent hole communicating with the cavity. The plug body is capable of being installed in the vent hole. The plug body is provided with a vent channel communicating with the cavity and the outside of the tire mold. Along the direction away from the cavity, the vent channel includes a gradient section, a throat, and an enlarged section connected in sequence. The gradient section includes two oppositely arranged transition surfaces, and the distance between the two transition surfaces gradually decreases along the direction away from the cavity. The throat is defined as a gap formed by the narrowest points of the two transition surfaces, and the width of the gap approaches zero. Along the direction away from the cavity, the cross-sectional area of ​​the enlarged portion gradually increases.

[0008] As a preferred technical solution, a number of ribs are provided between the two transition surfaces.

[0009] As a preferred technical solution, the thickness of the rib is no more than 1 mm; And / or, the surface of the rib is flush with the cavity surface.

[0010] As a preferred technical solution, the transition surface is textured.

[0011] As a preferred technical solution, the texture is provided as a plurality of spaced convex strips, the width of the convex strips is provided as 0.1-0.5mm, and a groove is formed between adjacent convex strips, the depth of the groove is provided as 0.02-0.1mm; the angle between the extending direction of the convex strips and the extending direction of the gap is provided as 15-90°. Alternatively, the texture may be formed through a texturing process.

[0012] As a preferred technical solution, the height of the gradient portion in the direction away from the cavity is no more than 2mm; And / or, the transition surface is set as a plane or an outwardly convex curved surface.

[0013] As a preferred technical solution, the end of the plug near the cavity is columnar, and the length of the gap is not less than one-quarter of the diameter of the plug.

[0014] As a preferred technical solution, the enlarged section includes two opposing slopes, and the distance between the two slopes gradually increases in the direction away from the cavity.

[0015] As a preferred technical solution, the end of the slope away from the cavity is connected to a cylindrical surface, and the angle between the slope and the cylindrical surface is not less than 120°; And / or, the slope is set as a plane or a curved surface.

[0016] As a preferred technical solution, the plug is manufactured using 3D printing technology; And / or, the plug is made of breathable steel.

[0017] The beneficial effects of this utility model are as follows: 1. The width of the gradient section of this utility model gradually narrows away from the cavity, so that the resistance of the rubber material in the cavity gradually increases as it enters the gradient section and moves towards the throat, minimizing the overflow of rubber material. Furthermore, when the rubber material overflows from the throat and reaches the enlarged section, the pressure on the rubber material drops instantly, and the rubber material overflowing into the enlarged section rapidly expands to form an enlarged section. When the rubber product is demolded, the enlarged section breaks off from the rubber product at the throat and remains at the enlarged section, which can be easily and quickly removed during the cleaning cycle. Compared with the traditional vent sleeve, this utility model improves the product yield, leaves less rubber hair on the surface of the rubber product, improves the aesthetics, and reduces rubber waste. At the same time, the structure is simple, not easily damaged, greatly reduces the difficulty of maintenance of tire molds, and is inexpensive.

[0018] 2. The ribs between the two transition surfaces of this utility model can prevent the adhesive from flowing into the gradient section, while also increasing the flow resistance of the adhesive in the cavity and reducing the amount of adhesive overflowing from the throat.

[0019] 3. The texture of the transition surface of this utility model can increase the friction and increase the resistance of the rubber material to movement on the surface of the plug facing the cavity, making it less likely for the rubber material to penetrate into the venting channel of the plug. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the overall structure of a first embodiment of the exhaust plug for a tire mold according to the present invention; Figure 2 for Figure 1 A sectional view; Figure 3 This is a cross-sectional view of a second embodiment of the exhaust plug for a tire mold according to the present invention; Figure 4 This is a schematic diagram of the overall structure of a third embodiment of the exhaust plug for a tire mold according to the present invention; Figure 5 This is a schematic diagram of the overall structure of the fourth embodiment of the exhaust plug for tire molds according to the present invention; Figure 6 for Figure 5 A schematic diagram of the texture structure in the image; Figure 7 for Figure 6 Sectional view along the AA direction.

[0021] In the diagram: 1-plug body, 2-gradient section, 21-transition surface, 3-gap, 4-enlarged section, 41-slope, 42-cylindrical surface, 5-rib, 6-texture, 61-protrusion, 62-groove. Detailed Implementation

[0022] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings. Example 1

[0023] Please refer to Figure 1 and Figure 2 This invention provides a first embodiment of an exhaust plug for a tire mold, wherein the tire mold has a cavity inside, the rubber material is vulcanized in the cavity to form a rubber product, the tire mold has an exhaust hole communicating with the cavity, and this invention is assembled in the exhaust hole to discharge the air in the cavity. This utility model includes a plug body 1, the shape of which matches the vent hole and can be installed inside the vent hole; the plug body 1 is provided with a venting channel that connects the cavity and the outside of the tire mold, and during the vulcanization process, the gas in the cavity is discharged to the outside of the tire mold through the venting channel. Specifically, the exhaust channel includes a gradient section 2, a throat, and an enlarged section 4, which are distributed and connected sequentially along the direction away from the cavity. The gradient section 2 is connected to the cavity and includes two opposing transition surfaces 21. The distance between the two transition surfaces 21 gradually decreases along the direction away from the cavity. The gradient section 2 is shaped like a "trumpet mouth," which gradually increases the resistance of the rubber material in the cavity as it enters the gradient section 2 and moves towards the throat, minimizing the overflow of the rubber material. The throat is a gap 3 formed at the narrowest point of the two transition surfaces 21. The gap 3 is elongated and its width is close to zero, ensuring that the gas in the cavity can pass through the gap 3 while minimizing the overflow of the rubber material. The cross-sectional area of ​​the enlarged section 4 gradually increases along the direction away from the cavity. When the rubber material overflows from the throat and reaches the enlarged section 4, the pressure on the rubber material drops instantly, and the rubber material overflowing into the enlarged section 4 expands rapidly to form an enlarged section. When the rubber product is demolded, the enlarged section breaks off from the rubber product at the throat, and can be easily and quickly removed during the cleaning cycle.

[0024] In other embodiments, the shape of the gap 3 may also be curved, so as to facilitate the smooth discharge of gas from the cavity and facilitate production and processing.

[0025] It should be noted that, under the existing processing conditions, the width of the gap 3 can be processed to 0.02mm; of course, if the width of the gap 3 is less than 0.02mm, it can achieve better technical results.

[0026] Specifically, please refer to Figure 1 and Figure 2 The transition surface 21 is designed as a convex curved surface, which makes the resistance increase faster and faster as the rubber material in the gradient section 2 moves towards the throat, resulting in a better blocking effect on the rubber material.

[0027] Further, please refer to Figure 2 The height w of the gradient section 2 along the direction away from the cavity is preferably not greater than 2mm, that is, the height difference between the widest and narrowest part of the flared gradient section 2 is not greater than 2mm. When the rubber product is demolded, too much rubber material remaining in the gradient section 2 is avoided, which affects the aesthetics of the surface of the rubber product.

[0028] In this embodiment, please refer to Figure 2 The enlarged section 4 includes two opposing slopes 41. The distance between the two slopes 41 gradually increases in the direction away from the cavity, so that the space of the enlarged section 4 increases rapidly in the direction away from the throat, thereby ensuring that the pressure on the material after it overflows from the throat is reduced instantly.

[0029] Further, please refer to Figure 2The end of the slope 41 away from the cavity is connected to the cylindrical surface 42. The included angle α between the slope 41 and the cylindrical surface 42 is not less than 120°. The rubber material overflowing from the throat can expand rapidly at the slope 41. Furthermore, the slope 41 can be processed into a flat or curved surface according to the actual situation, so as to ensure that the overflowing rubber material can expand rapidly into the enlarged part and facilitate production and processing.

[0030] In this embodiment, please refer to Figure 1 The end of the plug 1 near the cavity is columnar and matches the vent hole of the tire mold, making it easy to fix in the vent hole. The end face of the plug 1 near the cavity is flush with the cavity surface. In order to ensure the venting effect, the length of the gap 3 should not be greater than the diameter of the plug 1 and not less than one-quarter of the diameter of the plug 1.

[0031] It should be noted that, in order to facilitate production and ensure processing accuracy, the plug body 1 is preferably made by 3D printing process; in order to ensure the venting effect, the material of the plug body 1 is preferably made of breathable steel. Example 2

[0032] Please refer to Figure 3 The main difference between this embodiment and Embodiment 1 is that the transition surface 21 is a plane, which can also achieve the effect of preventing the rubber material in the gradient part 2 from moving towards the throat, and the processing method is simpler. Example 3

[0033] Please refer to Figure 4 The main difference between this embodiment and Embodiment 1 is that: a number of ribs 5 are provided between the two transition surfaces 21. The surface of the ribs 5 is flush with the cavity surface. The number of ribs 5 can increase the flow resistance of the adhesive in the cavity. At the same time, the number of ribs 5 can also prevent the adhesive from flowing into the gradient part 2, thereby reducing the amount of adhesive overflowing from the throat.

[0034] Specifically, please refer to Figure 4 The thickness of the rib 5 is preferably no more than 1 mm, so that it can block the rubber material without affecting the air venting effect. Example 4

[0035] Please refer to Figures 5-7 The main difference between this embodiment and Embodiment 1 is that the transition surface 21 is provided with texture 6, which can increase the friction between the adhesive and the transition surface 21, thereby increasing the resistance of the adhesive moving towards the throat, making it less likely for the adhesive to penetrate into the exhaust channel of the plug 1.

[0036] Specifically, please refer to Figures 5-7The texture 6 is provided as a plurality of spaced protrusions 61, the width b of which is preferably 0.1-0.5 mm, and the width of the groove 62 is the same as the width of the protrusions 61; a groove 62 is formed between adjacent protrusions 61, and the depth h of the groove 62 is preferably 0.02-0.1 mm; the angle β between the extension direction of the protrusions 61 and the extension direction of the gap 3 is preferably 15-90°, which can effectively improve the resistance to the adhesive; in other embodiments, the texture 6 on the transition surface 21 can also be formed by a roughening process, so as to increase the friction coefficient of the transition surface 21, increase the roughness of the gradient part 2, and prevent the adhesive from overflowing from the throat.

[0037] It should be noted that Embodiments 3 and 4 of this utility model can be used alone or in combination with each other, as long as they can effectively prevent the adhesive from flowing into the throat.

[0038] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vent plug for a tire mold, wherein the tire mold has a cavity formed inside, and the tire mold has a vent hole communicating with the cavity, characterized in that, Includes a plug (1), which can be installed in the vent hole; the plug (1) is provided with an vent channel that connects the cavity and the outside of the tire mold; Along the direction away from the cavity, the exhaust channel includes a gradient section (2), a throat and an enlarged section (4) connected in sequence. The gradient section (2) includes two oppositely arranged transition surfaces (21), and the distance between the two transition surfaces (21) gradually decreases in the direction away from the cavity; The throat is defined as a gap (3) formed by the narrowest points of the two transition surfaces (21), and the width of the gap (3) is close to zero; Along the direction away from the cavity, the cross-sectional area of ​​the enlarged part (4) gradually increases.

2. The vent plug for a tire mold according to claim 1, characterized in that, A number of ribs (5) are provided between the two transition surfaces (21).

3. The vent plug for a tire mold according to claim 2, characterized in that, The thickness of the rib (5) is no more than 1 mm; And / or, the surface of the rib (5) is flush with the cavity surface.

4. A vent plug for a tire mold according to claim 1 or 3, characterized in that, The transition surface (21) is provided with a texture (6).

5. A vent plug for a tire mold according to claim 4, characterized in that, The texture (6) is provided as a plurality of spaced protrusions (61), the width of the protrusions (61) is 0.1-0.5mm, and a groove (62) is formed between adjacent protrusions (61), the depth of the groove (62) is 0.02-0.1mm; the angle between the extension direction of the protrusions (61) and the extension direction of the gap (3) is 15-90°. Alternatively, the texture (6) may be formed by a texturing process.

6. A vent plug for a tire mold according to claim 1, characterized in that, The height of the gradient section (2) in the direction away from the cavity is no more than 2 mm; And / or, the transition surface (21) is set as a plane or an externally convex curved surface.

7. A vent plug for a tire mold according to claim 1, characterized in that, The plug (1) is columnar at one end near the cavity, and the length of the gap (3) is not less than one-quarter of the diameter of the plug (1).

8. A vent plug for a tire mold according to claim 1, characterized in that, The enlarged section (4) includes two oppositely arranged slopes (41), and the distance between the two slopes (41) gradually increases in the direction away from the cavity.

9. A vent plug for a tire mold according to claim 8, characterized in that, The end of the slope (41) away from the cavity is connected to a cylindrical surface (42), and the angle between the slope (41) and the cylindrical surface (42) is not less than 120°; And / or, the slope (41) is set as a plane or a curved surface.

10. A vent plug for a tire mold according to claim 1, characterized in that, The plug (1) is made using 3D printing technology; And / or, the material of the plug (1) is set to be breathable steel.

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