High-precision coating mold

Abstract

The utility model discloses a high-precision cladding mould, which comprises a shrinkage mouth mould, a shrinkage core mould, a smoothing mouth mould, an inner support sleeve and a steel wire rope, the shrinkage core mould is arranged in the shrinkage mouth mould, an inner pipe penetrates through the center of the shrinkage mouth mould and the center of the shrinkage core mould, and the shrinkage core mould and the shrinkage mouth mould jointly form an outer layer material runner. The outer-layer material runner comprises a contraction runner and a straight runner; and the contraction runner is communicated with the straight runner. And a smoothing die is arranged at an outer layer material outlet of the smoothing runner. The inner supporting sleeve is arranged in the inner pipe, and a steel wire rope is connected to the inner supporting sleeve. A pressing plate is arranged at the rear end of the shrinkage mouth die, a circle of adjusting screws are arranged on the side face of the pressing plate, and the adjusting screws penetrate through the pressing plate to abut against the shrinkage mouth die. Through in-mold compounding, the problem that the compounding effect is poor due to small compounding pressure is solved, the low outer layer coating precision caused by the fact that the inner pipe is too thin or softened and deformed at high temperature is avoided, and the uneven outer layer wall thickness caused by the fact that the installation precision of a production line is insufficient is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of plastic pipe forming and extrusion, and particularly relates to a high-precision coating die. Background Art

[0002] When designing plastic pipes, some need to add a functional layer on the outer layer. Due to the large differences in material properties such as processing temperature, decomposition temperature, and fluidity of the functional layer, it is not suitable for co-extrusion molding. At this time, the common technical means is to coat or plate a layer after the inner pipe is cooled and shaped. However, there are often several problems in the existing technology: 1. The outer layer is adsorbed on the outer surface of the inner pipe by means of vacuum pumping, and the composite pressure is insufficient, resulting in limited composite effect. And the outer surface of the outer layer is generally not flat due to poor demolding and small composite pressure. 2. When using the pressure extrusion method, the outer layer material is compounded with the pipe before the extrusion pressure is released. However, due to the high material temperature and the thin wall of the inner pipe, the inner pipe is easily softened and deformed, and the effect is not good. Or due to the installation accuracy problem of the production line, the concentricity of the inner pipe and the die is insufficient, and the wall thickness uniformity cannot be adjusted well. At this time, recalibrating the production line accuracy not only requires a large amount of work, is time-consuming and laborious, but also considering the factor of the self-weight sag of the sample pipe, the effect may not be satisfactory when the accuracy requirement is extremely high. Patent CN107650352A discloses an HDPE ribbed pipe coating die and its ribbed pipe forming method, CN207256825U discloses a runner assembly of a coating extrusion die and a coating extrusion die, CN201530125U discloses a coating die for a pipe production line, and CN201291591Y discloses a double-pipe coating die, but none of them can completely solve the above problems. Summary of the Utility Model

[0003] Aiming at the above problems, the utility model aims to provide a high-precision coating die to solve the problems of small composite pressure during outer layer coating, easy softening and deformation of the inner layer resulting in low bonding strength, poor forming accuracy, and uneven outer surface.

[0004] The technical problems solved by the utility model can be realized by the following technical solutions: A high-precision coating die includes a shrinking die head, a shrinking core die, a smoothing die head, an inner support sleeve, and a steel wire rope. The shrinking core die is arranged inside the shrinking die head. The inner pipe passes through the centers of the shrinking die head and the shrinking core die. The shrinking core die and the shrinking die head together form an outer layer material flow channel. The outer layer material flow channel includes a shrinking flow channel and a straight flow channel. The shrinking flow channel gradually shrinks towards the outer surface of the inner pipe starting from the outer layer material inlet. The shrinking flow channel is communicated with the straight flow channel. A smoothing die head is arranged at the outer layer material outlet of the straight flow channel. The smoothing die head is fixedly installed on the shrinking die head. The inner support sleeve is arranged inside the inner pipe, and a steel wire rope is connected to the inner support sleeve.

[0005] An arc transition is arranged between the shrinking section and the straight section on the inner surface of the shrinking core die.

[0006] The smoothing die is fixedly connected to the shrinkage die by screws.

[0007] The inner surface of the smoothing die is plated with a non-stick material.

[0008] The main body of the inner support sleeve is of a cylindrical structure, and the outer diameter of the inner support sleeve is slightly smaller than the inner diameter of the inner tube.

[0009] The length of the inner support sleeve is greater than the sum of the straight sections of the smoothing die and the shrinkage die, and the length range during installation covers the outlet of the shrinkage core die to the outlet of the smoothing die.

[0010] A pressing plate is arranged at the rear end of the shrinkage die. A circle of adjusting screws is arranged on the side surface of the pressing plate, and the adjusting screws pass through the pressing plate and press against the outer surface of the rear end of the shrinkage die.

[0011] Compared with the prior art, the utility model has the following beneficial effects: through in-mold compounding, the utility model solves the problem of poor compounding effect caused by small compounding pressure, avoids the low outer layer coating accuracy caused by too thin inner tube or softening and deformation at high temperature, and avoids the uneven outer layer wall thickness caused by insufficient installation accuracy of the production line; the smoothing die ensures the smooth demolding of the outer layer material, keeps the outer surface of the pipeline smooth, and is convenient for disassembly and cleaning; the arc transition is arranged on the shrinkage core die to facilitate the entry of the inner tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic structural diagram of the utility model;

[0013] In the figure: 1-inner support sleeve, 2-inner tube, 3-smoothing die, 4-shrinkage die, 5-shrinkage core die, 6-outer layer material outlet, 7-outer layer material inlet, 8-steel wire rope, 9-pressing plate, 10-adjusting screw, 11-outer layer material flow channel, 12-arc transition, 13-advancing direction of the inner tube. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] In order to make the technical means, creative features, achieved purposes and functions of the utility model easy to understand, the utility model will be further described below with reference to specific drawings.

[0015] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "one end", "the other end", "outer side", "upper", "inner side", "horizontal", "coaxial", "central", "end portion", "length", "outer end", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0016] Combined with the attached Figure 1 As shown, this embodiment discloses a high-precision coating die, including a shrinkage die head 4, a shrinkage core die 5, a smoothing die head 3, an inner support sleeve 1 and a steel wire rope 8. The shrinkage core die 5 is arranged inside the shrinkage die head 4. The inner tube passes through the centers of the shrinkage die head 4 and the shrinkage core die 5. The shrinkage core die 5 and the shrinkage die head 4 together form an outer layer material flow channel 11. The outer layer material flow channel 11 includes a shrinkage flow channel and a straight flow channel. The shrinkage flow channel gradually shrinks from the outer layer material inlet 7 towards the outer surface of the inner tube 2. The shrinkage flow channel is connected to the straight flow channel. At the outer layer material outlet of the straight flow channel, there is a smoothing die head 3, and the smoothing die head 3 is installed and fixed on the shrinkage die head 4.

[0017] The shrinkage die head 4 and the shrinkage core die 5 are fixed on the inner tube extrusion die upstream. An arc transition 12 is arranged between the shrinkage section and the straight section on the inner surface of the shrinkage core die 5 to facilitate the entry of the inner tube 2. The inner diameter of the shrinkage core die 5 is basically the same as the inner diameter of the sizing sleeve upstream on the production line, ensuring that the outer diameter of the pipe is only slightly smaller than the inner diameter of the core die, so that the inner tube 2 can smoothly enter the inside of the core die and remain concentric with the core die.

[0018] The shrinkage section of the shrinkage die head 4 and the outer surface of the shrinkage core die 5 together form a shrinkage flow channel. The material gradually shrinks and approaches the outer surface of the inner tube 2 after entering from the outer layer material inlet 7. After passing through the shrinkage flow channel, the material is compounded with the outer surface of the inner tube 2 in the straight flow channel. At this time, the outer surface of the inner tube 2, the straight section of the shrinkage die head, and the inner surface of the smoothing die head together form a straight section flow channel, ensuring that the material is compounded under pressure and extruded smoothly at the same time.

[0019] The smoothing die head 3 is fixedly connected to the shrinkage die head 4 by screws. The inner surface of the smoothing die head 3 is plated with a material that does not stick to the outer layer material, such as Teflon, polyether ether ketone, etc., to ensure the smooth demolding of the outer layer material and keep the outer layer surface flat. The smoothing die head 3 is independent of the shrinkage die head 4, which avoids plating the entire die head with special materials to save costs. After long-term production, it is convenient to disassemble and clean the inner surface material and re-plate the special material after wear.

[0020] The inner support sleeve 1 is arranged inside the inner tube 2, and a steel wire rope 8 is connected to the inner support sleeve 1. The main body of the inner support sleeve 1 is a cylindrical structure, and the outer diameter of the inner support sleeve 1 is slightly smaller than the inner diameter of the inner tube 2. The length of the inner support sleeve 1 is greater than the sum of the straight sections of the smoothing die head 3 and the shrinkage die head 4. And when installed, the length range of the inner support sleeve 1 covers the outlet of the shrinkage core die 5 to the outlet of the smoothing die head 3, preventing the inner tube from being too thin or deforming due to heat softening, resulting in low composite strength and low dimensional accuracy after compounding. The inner support sleeve 1 is connected to the core die of the inner tube extrusion die upstream through the steel wire rope 8, which can pull the inner support sleeve 1, and the inner support sleeve 1 will not move downstream with the inner tube.

[0021] A pressing plate 9 is provided at the rear end of the shrinking die head 5. A circle of adjusting screws 10 is provided on the side surface of the pressing plate 9. The adjusting screws 10 pass through the pressing plate 9 and press against the outer surface of the rear end of the shrinking die head 4. The position of the shrinking die head 4 can be adjusted by the adjusting screws 10, and then the concentricity between the shrinking die head 4 and the shrinking core die 5 can be adjusted, so as to ensure that the gap of the outer layer material flow channel is uniform and the outer layer wall thickness is uniform, avoiding the requirement of ultra-high concentricity for the whole production line.

[0022] The utility model solves the problem of poor composite effect caused by small composite pressure through in-mold composite; avoids the low outer layer coating accuracy caused by too thin inner tube or softening and deformation at high temperature; avoids the uneven outer layer wall thickness caused by insufficient installation accuracy of the production line.

[0023] The above is only the preferred embodiment of the utility model, and does not impose any form of limitation on the utility model. Any simple modification, equivalent change or modification made to the above embodiments based on the technical principle of the utility model still falls within the scope of the technical solution of the utility model.

Claims

1. A high-precision coating mold, comprising a shrinking die (4), a shrinking core die (5), a smoothing die (3), an inner support sleeve (1) and a steel wire rope (8), characterized in that: The shrinking core mold (5) is arranged in the shrinking die (4), and the inner tube passes through the center of the shrinking die (4) and the shrinking core mold (5). The shrinking core mold (5) and the shrinking die (4) together constitute an outer material flow channel (11). The outer material flow channel (11) includes a shrinking flow channel and a straight flow channel. The shrinking flow channel gradually shrinks from the outer material inlet (7) to the outer surface of the inner tube (2). The shrinking flow channel and the straight flow channel are connected. A smoothing die (3) is arranged at the outer material outlet of the straight flow channel. The smoothing die (3) is installed and fixed on the shrinking die (4). The inner support sleeve (1) is arranged in the inner tube (2), and a steel wire rope (8) is connected to the inner support sleeve (1).

2. A high-precision coating mold according to claim 1, characterized in that: An arc transition (12) is provided between the contraction section and the straight section of the inner surface of the contraction core mold (5).

3. A high-precision coating mold according to claim 1, characterized in that: The smoothing die (3) is fixedly connected to the shrinking die (4) via screws.

4. The high-precision coating mold according to claim 1, characterized in that: The inner surface of the smoothing die (3) is coated with a non-stick material.

5. The high-precision coating mold according to claim 1, characterized in that: The main body of the inner support sleeve (1) is a cylindrical structure, and the outer diameter of the inner support sleeve (1) is slightly smaller than the inner diameter of the inner tube (2).

6. The high-precision coating mold according to claim 1, characterized in that: The length of the inner support sleeve (1) is greater than the sum of the straight sections of the smoothing die (3) and the shrinking die (4), and when installed, the length range of the inner support sleeve (1) covers the outlet of the shrinking core die (5) to the outlet of the smoothing die (3).

7. The high-precision coating mold according to claim 1, characterized in that: A pressure plate (9) is provided at the rear end of the shrinking die (4), and a circle of adjusting screws (10) is provided on the side of the pressure plate (9). The adjusting screws (10) pass through the pressure plate (9) to support the shrinking die (4).

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