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

Abstract

The wide-base tire small shoulder pad tread extrusion mold plate proposed in the present invention comprises an upper plate and a lower plate, which are separated by a parting surface and are detachably connected, a tread rubber outlet is provided on the dividing surface of the upper plate, and a full chamfer is provided on the rear opening of the tread rubber outlet of the upper plate, a plurality of downwardly protruding arc-shaped platforms are provided on the end face of the upper outlet of the upper plate, which are used to extrude and form the bottom of the pattern 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 extend in thickness direction to the inside of the lower plate, the arc-shaped opening surfaces are directly opposite to the arc-shaped platforms of the upper plate up and down, and the scheme improves the upper and lower outlets of the mold plate to balance the pressure on the middle rubber material and the tire wing rubber material of the tread, so that the bottom of the tread rubber sheet formed by extrusion is flat, the tread groove bottom meets the process requirements, and the risk of residual bubbles inside the tire is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tire preparation, in particular to an extrusion die plate 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.10 . Summary of the invention

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

[0004] A tread extrusion die plate for a wide-base tire with a small shoulder pad comprises an upper plate and a lower plate, the upper plate and the lower plate are separated by a dividing surface and 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 for extruding and forming a groove bottom on the front side of the tread, a plurality of arcuate opening surfaces are provided on the front opening of the lower plate, the arcuate opening surfaces extend vertically to the bottom of the lower plate and extend inwardly of the lower plate in the thickness direction, and the arcuate opening surfaces are vertically opposite to the pointed corners of the upper 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] The invention improves the upper outlet and the lower outlet of the die plate to balance the pressure on the tread middle rubber material and the tire wing rubber material, so that the bottom of the tread rubber sheet formed by extrusion is flat and the tread groove bottom meets the process requirements, reducing the possibility of residual bubbles in the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 , 2 This is a schematic diagram of the structure of the wide-base tire with small shoulder pad tread extrusion die plate.

[0009] Figure 3 , 4 Front and rear views of the die plate for the wide-base tire with small shoulder pad tread.

[0010] Figure 5 , 6Schematic diagram of the structure of the upper plate.

[0011] Figure 7 , 8 This is a schematic diagram of the structure of the lower plate.

[0012] Fig. 9 It is a cross-sectional view of the extruded tread rubber sheet of the present invention.

[0013] Fig.10 It is a cross-sectional view of a tread rubber strip extruded in the prior art.

[0014] In the figure: a die plate 10, an upper plate 11, a tread rubber outlet 111, a full chamfer 112, a tread wing rubber upper outlet 113, a composite outlet 114, a tread crown rubber outlet 115, a pointed corner 116, a lower plate 12, a left tread wing rubber lower outlet 121, a right tread wing rubber lower outlet 122, an arc-shaped open surface 123, a tread rubber sheet 100, a tread crown rubber 110, a tread wing rubber 120, a tread front side 130, a tread bottom 140, a groove bottom 150, a pattern block 160, and a wave pattern 170. DETAILED DESCRIPTION

[0015] 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.

[0016] See also Figure 1-8 The embodiment of the present invention provides a wide-base tire small shoulder pad tread extrusion die plate 10, comprising an upper plate 11 and a lower plate 12, the upper plate 11 and the lower plate 12 are separated by a parting surface, and the two are detachably connected, a tread rubber outlet 111 is provided on the parting surface of the upper plate 11, and a full chamfer 112 is provided at the rear of the tread rubber outlet 111 of the upper plate 11, so as to increase the amount of rubber material of the crown rubber 110 entering the die plate 10 from the pre-die plate 10, thereby increasing the pressure of the rubber material when passing through the upper plate 11, and improving the tire pressure by changing the pressure point. To solve the problem of uneven bottom of the tread rubber, a plurality of downwardly protruding pointed corners 116 are arranged on the end face of the upper outlet 111 of the upper plate 11, which are used to extrude and form the groove bottom 150 of the tread front side 130, and the tread between adjacent molding platforms forms a pattern block 160. A plurality of arc-shaped open surfaces 123 are arranged at the front mouth of the lower plate 12, and the arc-shaped open surfaces 123 extend vertically to the bottom of the lower plate 12 and extend to the inside of the lower plate 12 in the thickness direction. The arc-shaped open surfaces 123 are directly opposite to the pointed corners 116 of the upper plate 11 up and down.

[0017] 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 as 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 as surface A.

[0018] See also Fig. 9 The 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 rubber surface of the tread crown rubber 110 extruded from the upper outlet 111 of the upper plate 11 is called the tread front surface 130, and the rubber surface of the tread crown rubber 110 extruded from the lower outlet 121 of the lower plate 12 is called the tread bottom 140. Usually, the tread front surface 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 the tread bottom 140 If it is not flat and cannot form a plane, it 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 subsequent processes. During bonding, the bottom 140 of the tread is required to be level, without grooves or ripples. If it is not flat, the subsequent film bonding will cause incomplete bonding, trapping air and forming bubbles, which will form hidden dangers inside the tire and cause tire delamination during later use. Therefore, it is very important to control the flatness of the extrusion of the bottom 140 of the tread.

[0019] 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 111 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 prior art, the lower outlet 121 is a flat mouth. 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 from 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.

[0020] 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.

[0021] 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.

[0022] Furthermore, the upper opening of the upper plate 11 is composed of the upper outlet 113 of the tire wing rubber, the composite outlet 114 (the tire wing rubber 120 and the tire crown rubber 110 are composited), 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 is to cover 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 entering, the composite cross-linking degree between the tire wing rubber 120 and the tire crown rubber 110 is enhanced.

[0023] 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 to form a small shoulder pad.

[0024] The modules or units in the device of the embodiment of the present invention may be combined, divided or deleted according to actual needs.

[0025] 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.

[0026] 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 plate, characterized in that: It comprises an upper plate and a lower plate, which are separated by a dividing surface and 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 arc-shaped platforms 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 extends to the inside of the lower plate, the arc-shaped opening surfaces are directly opposite to the arc-shaped platforms of the upper plate up and down, so that the rubber material can smoothly transition from the mold.

2. The wide-base tire small shoulder pad tread extrusion die plate 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 plate 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.

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