A wide base tire with small shoulder pad tread extrusion die assembly

Abstract

The wide-base tire small shoulder pad tread extrusion die assembly proposed by the present invention comprises a die plate and a pre-die plate, a full chamfer is provided at the rear opening of the tread rubber outlet of the upper plate, a plurality of downwardly protruding pointed corners are arranged on the end surface of the upper outlet of the upper plate, a plurality of arc-shaped opening surfaces are provided at the front opening of the lower plate, the arc-shaped opening surfaces are vertically opposite to the pointed corners of the upper plate, the pre-die plate comprises a left end mounting plate, a right end mounting plate, a parting surface, and a side plate, the rear opening of the die plate is correspondingly assembled with the front opening of the pre-die plate, and the height of the rear opening of the lower plate of the die plate is kept equal to the lower end edge of the tread crown rubber extrusion channel of the pre-die plate, the present invention solves the problem of grooves and wave patterns in the circumferential direction of the bottom of the tread by fully chamfering the rear opening of the die plate and by opening an arc-shaped opening surface at the front opening of the die plate; and solves the problem of wave patterns formed at the bottom of the tread along the radial direction of the tread by changing the height of the lower plate of the die plate to cooperate with the lower end edge of the pre-die plate.

Description

Technical Field

[0001] The invention relates to the technical field of tire preparation, in particular to an extrusion die assembly for a wide-base tire with a small shoulder pad tread. Background Art

[0002] The tread structure design of wide-base tires requires that the middle thickness is thinner and the width is wider. During the tread extrusion process, the middle thickness pressure is insufficient, resulting in waves at the bottom of the tread during the extrusion process. The quality of the film at the bottom of the tread is poor, making it difficult to use in the subsequent processes. In severe cases, bubbles will appear under the crown, and the shoulder will delaminate during the use of the tire. Fig.17 , 18 . Summary of the invention

[0003] It is necessary to propose a wide base tire small shoulder pad tread extrusion die component.

[0004] A wide-base tire with a small shoulder pad tread extrusion die assembly comprises a die plate and a pre-die plate, the die plate and the pre-die plate are correspondingly assembled in a die box, the die plate comprises an upper plate and a lower plate, the upper plate and the lower plate are separated by a partition surface, and the two are detachably connected, a tread rubber outlet is provided on the parting surface of the upper plate, a full chamfer is provided on the rear opening of the tread rubber outlet of the upper plate, a plurality of downwardly protruding pointed corners are provided on the end surface of the upper outlet of the upper plate, which are used for extruding and forming the bottom of the tread groove on the front side of the tread, a plurality of arc-shaped opening surfaces are provided on the front opening of the lower plate, the arc-shaped opening surfaces extend vertically to the bottom of the lower plate, and the thickness direction extends downward. The inner portion of the plate extends, and the arc-shaped opening surface is vertically opposite to the pointed corner of the upper plate. The pre-mouth mold plate includes a left-end mounting plate, a right-end mounting plate, a parting surface, and a side plate. The left-end mounting plate, the right-end mounting plate, and the side plate are used for assembly with the mouth box. A crown rubber extrusion channel is reserved between the parting surface and the side plate, and a wing rubber extrusion channel is formed between the parting surface and the side wall of the mouth box. The front opening of the crown rubber extrusion channel and the wing rubber extrusion channel is smaller than the rear opening. The rear opening of the mouth plate is assembled corresponding to the front opening of the pre-mouth mold plate, and the height of the rear opening of the lower plate of the mouth mold plate is kept equal to the lower end edge of the crown rubber extrusion channel of the pre-mouth mold plate.

[0005] Preferably, the upper opening of the upper plate is the tire wing rubber upper outlet, the composite outlet, and the tire crown rubber outlet from both sides to the middle, and the width direction of the fully chamfered width of the rear opening of the upper plate covers the composite outlet and the tire crown rubber outlet.

[0006] Preferably, the rear opening of the lower plate includes a left tire wing rubber lower outlet and a right tire wing rubber lower outlet, and the two are not connected.

[0007] Preferably, a tire wing rubber retaining boss is further provided on the side wall of the parting surface connected to the tire wing rubber extrusion channel.

[0008] Preferably, the tire wing rubber retaining boss is trapezoidal in shape.

[0009] Preferably, the tire wing rubber retaining boss is triangular in shape.

[0010] In the present invention, the problem of grooves and wave patterns in the circumferential direction of the bottom of the tread is solved by opening a full chamfer at the rear opening of the die plate and opening an arc-shaped opening surface at the front opening of the die plate; the problem of wave patterns formed along the radial direction of the tread at the bottom of the tread is solved by changing the matching relationship between the height Hkd of the rear opening of the lower plate of the die plate and the lower end edge Hyd of the crown rubber extrusion channel of the pre-die plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 , 2 This is a schematic diagram of the structure of the wide-base tire small shoulder pad tread extrusion die assembly.

[0012] Figure 3 , 4 Front and rear views of the die assembly for the wide-base tire with small shoulder pad tread.

[0013] Figure 5 , 6 Schematic diagram of the structure of the upper plate.

[0014] Figure 7 , 8 This is a schematic diagram of the structure of the lower plate.

[0015] Fig. 9 This is a schematic diagram of the structure of the wide-base tire small shoulder pad tread extrusion die assembly.

[0016] Fig.10 This is the front view of the wide-base tire small shoulder pad tread extrusion die assembly.

[0017] Fig.11 for Fig.10 Cross-sectional view of AA.

[0018] Fig.12 for Fig.11 A partial enlarged view of the .

[0019] Fig.13 It is a structural schematic diagram of the pre-mouth plate.

[0020] Fig.14 This is a bottom view of the pre-mouth plate.

[0021] Fig.15 A bottom view of another embodiment.

[0022] Fig.16 It is a cross-sectional view of the extruded tread rubber sheet of the present invention.

[0023] Fig.17This is a cross-sectional view of a tread rubber sheet extruded in the prior art, showing the wave pattern along the circumference of the tire.

[0024] Fig.18 This is a bottom view of a tread rubber sheet extruded in the prior art, showing the wavy lines along the radial direction.

[0025] In the figure: a die plate 10, an upper plate 11, a tread rubber outlet 111, a full chamfer 112, a wing rubber upper outlet 113, a composite outlet 114, a crown rubber outlet 115, a pointed corner 116, a lower plate 12, a left wing rubber lower outlet 121, a right wing rubber lower outlet 122, an arc-shaped open surface 123, a tread rubber sheet 100, a crown rubber 110, a wing rubber 120, a tread front 130, a tread bottom 140, a groove bottom 150, a pattern block 160, a wave pattern 170, a pre-die plate 20, a left end mounting plate 21, a right end mounting plate 22, a parting surface 23, a wing rubber retaining boss 231, a side plate 24, a crown rubber extrusion channel 25, and a wing rubber extrusion channel 26. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] See also Figure 1-15The embodiment of the present invention provides a wide-base tire small shoulder pad tread extrusion die assembly, including a die plate 10 and a pre-die plate 20, the die plate 10 and the pre-die plate 20 are correspondingly assembled in a die box, the die plate 10 includes an upper plate 11 and a lower plate 12, the upper plate 11 and the lower plate 12 are separated by a partition surface, and the two are detachably connected, a tread rubber outlet 111 is opened on the parting surface 23 of the upper plate 11, and a full-faced tread rubber outlet 111 is opened at the rear of the tread rubber outlet 111 of the upper plate 11 The chamfer 112 is used to increase the amount of the crown rubber 110 entering the die plate 10 from the pre-die plate 20, thereby increasing the pressure of the rubber when passing through the upper plate 11, and improving the problem of uneven bottom of the tread rubber by changing the pressure point. A plurality of pointed corners 116 protruding downward are provided on the end surface of the upper outlet of the upper plate 11, which are used to squeeze and form the groove bottom 150 of the tread front 130, and the tread between adjacent molding platforms forms a pattern block 160. The front opening of the lower plate 12 is provided with a plurality of arc-shaped opening surfaces 123, the arc-shaped opening surfaces 123 extend vertically to the bottom of the lower plate 12, and extend in the thickness direction to the inside of the lower plate 12, the arc-shaped opening surfaces 123 are vertically opposite to the pointed corners 116 of the upper plate 11, and the pre-mouth plate 20 includes a left end mounting plate 21, a right end mounting plate 22, a parting surface 23, and a side plate 24, which are used for assembly with the mouth box. A crown rubber extrusion channel 25 is reserved between the parting surface 23 and the side plate 24, and a wing rubber extrusion channel 26 is formed between the parting surface 23 and the side wall of the die box. The front openings of the crown rubber extrusion channel 25 and the wing rubber extrusion channel 26 are smaller than the rear openings. The rear opening of the die plate 10 is assembled corresponding to the front opening of the pre-die plate 20, and the height Hkd of the rear opening of the lower plate 12 of the die plate 10 is kept equal to the lower end edge Hyd of the crown rubber extrusion channel 25 of the pre-die plate 20.

[0028] See also Figure 1-9 In order to clearly express the components below, in the accompanying drawings, the surface where the rear port is located is the back side of the component, that is, the rubber inflow surface, represented by surface B, and the surface where the front port is located is the front side of the component, that is, the rubber outflow surface, represented by surface A.

[0029] See also Fig. 9The tread rubber sheet 100 formed by extruding from the die plate 10 includes a tread crown rubber 110 in the middle and tread wing rubbers 120 on both sides. The tread crown rubber 110 extruded from the upper outlet of the upper plate 11 is called the tread front 130, and the tread crown rubber 110 extruded from the lower outlet of the lower plate 12 is called the tread bottom 140. Usually, the tread front 130 forms the surface of the tire that directly contacts the ground, and its imperfect appearance will not affect the quality or quality of the tire, as well as the service life and safety. Then, if the tread bottom 140 is not flat, , cannot form a plane, which will directly affect the quality, service life and safety of the tire, because the bottom 140 of the tread will be bonded to other internal structures such as films in the subsequent process. During bonding, the bottom 140 of the tread is required to be level, without grooves or ripples 170. Because, if it is not flat, the subsequent film will be pasted, which will cause inaccurate bonding, trap air and form bubbles, which will form hidden dangers inside the tire and cause delamination of the tire during later use. Therefore, it is very important to control the flatness of the bottom 140 of the tread.

[0030] In the present solution, due to the requirement of wide-base tire models, an arc-shaped raised surface of a pattern block 160 is formed on the tread, so the upper outlet of the upper plate 11 is preset with a sharp corner 116. However, flatness is still required when the bottom 140 of the tread is extruded. In the original technology, the lower outlet is a flat outlet. When the rubber passes through the die plate 10, the rubber point S opposite the sharp corner 116 is subjected to a large pressure, so the rubber naturally flows to both sides, forming a pressure weak point here, with a small rubber pressure per unit area, and the pressure on the rubber is less than the pressure next to it. After the rubber is extruded out of the die plate 10, due to the properties of the rubber itself, it will expand when leaving the mold. Here, the rubber next to the S point is subjected to a large pressure, and the expansion rate is also large when leaving the mold, while the expansion rate of the S point is small, resulting in the appearance of wave patterns 170 or grooves at the bottom of the tread film 100 formed by extrusion.

[0031] Therefore, in this solution, an arc-shaped open surface 123 is provided at the front of the lower plate 12, so that the rubber material at point S expands earlier than the rubber material next to it when leaving the film, thereby compensating for the problem of smaller expansion capacity due to insufficient pressure.

[0032] The die expansion is defined as the outlet expansion effect caused by the cross-sectional dimensions of the extrudate being larger than the die size due to elastic recovery after the extrudate leaves the die during the extrusion process. The pressure drop along the flow direction is the cause of the die expansion.

[0033] See also Figure 16-18When the die plate 10 and the pre-die plate 20 are used together, the crown rubber 110 and the wing rubber 120 flow from the distal flow channel into the rear openings of the crown rubber extrusion channel 25 and the wing rubber extrusion channel 26 of the pre-die plate 20, and are then squeezed from the pre-die plate 20 to the tread rubber outlet 111 of the die plate 10, and are extruded by the die plate 10 to form a tread structure in a shape that meets the process requirements. The rubber passes through the lower end edges of the pre-die plate 20 and the die plate 10 to form the bottom of the tread rubber sheet 100. The tread bottom 140 is also bonded to the subsequent rubber sheet to form the internal structure of the tire. In order to ensure that there are no bubbles in the internal structure of the wheel, the bottom of the tire is required to be flat. There are at least two problems in the original design: First, since the tread of a wide-base tire needs to form a tread block 160 and a tread groove bottom 150, the existence of the pointed corner 116 of the upper plate 11 of the mouth plate 10 can easily cause grooves and wave patterns 170 in the circumferential direction of the bottom 140 of the tread; Second, due to the height difference caused by Hkd being lower than Hyd, the bottom 140 of the tread forms a wave pattern 170 along the radial direction of the tread.

[0034] Both of these situations will result in inaccurate lamination, air entrapment and bubble formation during subsequent lamination. Therefore, the present invention improves the mouth-shaped assembly from two aspects to solve the above two problems.

[0035] For the first problem, this patent solves the problem by providing a full chamfer 112 at the rear opening of the die plate 10 and providing an arc-shaped opening surface 123 at the front opening of the die plate 10. For the second problem, the problem is solved by changing the matching relationship between the height Hkd of the rear opening of the lower plate 12 of the die plate 10 and the lower edge Hyd of the crown rubber extrusion channel 25 of the pre-die plate 20. The two are set to the same height, so that there is no drop when the rubber material transitions from the pre-die plate 20 to the die plate 10, so that the rubber material transitions smoothly, thereby avoiding the generation of radial ripples 170.

[0036] Furthermore, the upper opening of the upper plate 11 is provided with the upper outlet 113 of the tire wing rubber, the composite outlet 114, and the tire crown rubber outlet 115 from both sides to the middle, and the width direction of the full chamfer 112 opened at the rear opening of the upper plate 11 covers the composite outlet 114 and the tire crown rubber outlet 115. Thus, by increasing the amount of tire wing rubber 120 and tire crown rubber 110 fed, the composite cross-linking degree between the tire wing rubber 120 and the tire crown rubber 110 is enhanced.

[0037] Furthermore, the rear opening of the lower plate 12 includes a left tire wing rubber lower outlet 121 and a right tire wing rubber lower outlet 122, which are not connected.

[0038] Furthermore, a tire wing rubber retaining boss 231 is provided on the side wall of the parting surface 23 connected to the tire wing rubber extrusion channel 26 .

[0039] The present invention is applicable to the production of two-composite tread die extrusion, that is, the tread crown rubber 110 and the tread wing rubber 120 are compounded in two layers, and the tread wing rubber 120 is formed into the left tread wing rubber 120 and the right tread wing rubber 120, which are not connected to each other. Therefore, after entering the die plate 10, it is extruded from the left tread wing rubber lower outlet 121 and the right tread wing rubber lower outlet 122 on both sides of the lower plate 12, and there is no channel for the tread wing rubber 120 to be extruded between the left tread wing rubber lower outlet 121 and the right tread wing rubber lower outlet 122, and then the tread wing rubber 120 in the corresponding pre-die plate 20 is connected and supplied, which causes the tread wing rubber 120 to pass through the pre-die plate 20, and the two sides are extruded from the left tread wing rubber lower outlet 121 of the die plate 10. The outlet 121 and the right tire wing rubber lower outlet 122 are squeezed out, while the middle cannot be squeezed out and is congested on the back side of the lower plate 12 between the left tire wing rubber lower outlet 121 and the right tire wing rubber lower outlet 122 of the die plate 10. After long-term use, the accumulated rubber will cause directional extrusion on the parting surface 23 of the pre-die plate 20, causing damage to the pre-die plate 20. Therefore, in the present scheme, a tire wing rubber retaining boss 231 is provided, so that when the tire wing rubber 120 flows into the pre-die plate 20 from the distal flow channel, it is guided by the tire wing rubber retaining boss 231 and divided into two left and right streams, corresponding to the left tire wing rubber lower outlet 121 and the right tire wing rubber lower outlet 122 entering the die plate 10, without congestion.

[0040] Furthermore, the tire wing rubber retaining boss 231 is in a trapezoidal shape.

[0041] Furthermore, the tire wing rubber retaining boss 231 is triangular in shape.

[0042] The tire wing rubber retention boss of the pre-mouth plate in this scheme is arranged on the channel for tire wing rubber extrusion to divert and divert the tire wing rubber, and the boss set in the pre-mouth in Patent No. 201611228639.0 is between two "crown side rubber flow channels 23", which is used for the production of three-composite treads. The two "crown side rubber flow channels 23" are arranged above the "crown rubber flow channel 21" to squeeze in the crown side rubber, rather than forming a channel for the circulation of tire wing rubber.

[0043] The modules or units in the device of the embodiment of the present invention may be combined, divided or deleted according to actual needs.

[0044] What is disclosed above is only the preferred embodiment of this patent document, and of course it cannot be used to limit the scope of rights of the present invention. Moreover, the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. A person of ordinary skill in the art can understand that the implementation of all or part of the processes of the above-mentioned embodiments and the equivalent changes made in accordance with the claims of the present invention still fall within the scope covered by the invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0045] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A wide-base tire with small shoulder pad tread extrusion die assembly, characterized in that: The invention comprises a die plate and a pre-die plate, which are correspondingly assembled in the die box, the die plate comprises an upper plate and a lower plate, the upper plate and the lower plate are separated by a dividing surface, and the two are detachably connected, a tread rubber outlet is provided on the parting surface of the upper plate, a full chamfer is provided on the rear opening of the tread rubber outlet of the upper plate, a plurality of downwardly protruding pointed corners are provided on the end surface of the upper outlet of the upper plate, which are used for extruding and forming the bottom of the tread groove on the front side of the tread, a plurality of arc-shaped opening surfaces are provided on the front edge of the lower plate, the arc-shaped opening surfaces are provided on the front edge of the lower plate in an oblique manner, the vertical direction of the arc-shaped opening surfaces extends to the bottom of the lower plate, and the thickness direction of the arc-shaped opening surfaces extends to the bottom of the lower plate The inner portion extends, and the arc-shaped opening surface is vertically opposite to the pointed corner of the upper plate to allow the rubber to smoothly transition from the mold. The pre-mouth mold plate includes a left-end mounting plate, a right-end mounting plate, a parting surface, and a side plate. The left-end mounting plate, the right-end mounting plate, and the side plate are used for assembly with the mouth box. A crown rubber extrusion channel is reserved between the parting surface and the side plate, and a wing rubber extrusion channel is formed between the parting surface and the side wall of the mouth box. The front opening of the crown rubber extrusion channel and the wing rubber extrusion channel is smaller than the rear opening. The rear opening of the mouth plate is assembled corresponding to the front opening of the pre-mouth mold plate, and the height of the rear opening of the lower plate of the mouth mold plate is kept equal to the lower end edge of the crown rubber extrusion channel of the pre-mouth mold plate.

2. The wide-base tire small shoulder pad tread extrusion die assembly according to claim 1, characterized in that: The upper opening of the upper plate is composed of the upper wing rubber outlet, the composite outlet, and the crown rubber outlet from both sides to the middle. The width direction of the fully chamfered corner of the rear opening of the upper plate covers the composite outlet and the crown rubber outlet.

3. The wide-base tire small shoulder pad tread extrusion die assembly according to claim 1, characterized in that: The rear opening of the lower plate includes a left tire wing rubber lower outlet and a right tire wing rubber lower outlet, and the two are not connected.

4. The wide-base tire small shoulder pad tread extrusion die assembly according to claim 1, characterized in that: A tire wing rubber retaining boss is also arranged on the side wall of the parting surface connected to the tire wing rubber extrusion channel.

5. The wide-base tire small shoulder pad tread extrusion die assembly according to claim 4, characterized in that: The tire wing rubber retaining boss is in a trapezoidal shape.

6. The wide-base tire small shoulder pad tread extrusion die assembly according to claim 4, characterized in that: The tire wing rubber retaining boss is in a triangular shape.

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