CN220700339U

CN220700339U - Mould for extruding cable plastic insulation or sheath

Info

Publication number: CN220700339U
Application number: CN202321897049.2U
Authority: CN
Inventors: 胡朝东; 宋涛; 胡爱斌
Original assignee: SHANGHAI FEIHANG ELECTRIC WIRE AND CABLE CO Ltd
Current assignee: SHANGHAI FEIHANG ELECTRIC WIRE AND CABLE CO Ltd
Priority date: 2023-07-19
Filing date: 2023-07-19
Publication date: 2024-04-02
Anticipated expiration: 2033-07-19

Abstract

The utility model discloses a die for extruding cable plastic insulation or a sheath, which belongs to the technical field of cable manufacturing equipment, and comprises a die sleeve and a die core, wherein the die core comprises a tubular bearing part, the tubular bearing part is a part of the die core, the tubular bearing part is provided with a pipe hole, and the inner diameter of the pipe hole is D1, and the die is characterized in that: the cable core extrusion device comprises an inner die, wherein the inner die is fixed on a die core through a pin hole, the inner die is provided with a die hole, the die hole is coaxial with the pipe hole, an extruded cable core passes through the die hole and the pipe hole in sequence, and the inner diameter D3 of the die hole is smaller than D1. The die can avoid the cable core from shifting in the extrusion process, avoid the cable insulation or the surface of the sheath from breaking or producing convex and concave, and improve the cable quality.

Description

Mould for extruding cable plastic insulation or sheath

Technical Field

The utility model belongs to the technical field of cable manufacturing equipment, and particularly relates to a die for extruding plastic insulation or a sheath of a cable.

Background

The quality of the plastic wire product is related to various factors such as the quality of the plastic itself, the performance of the extruder, the extrusion temperature, the tension and speed of the winding and unwinding wires, the preheating of the core wire, the cooling after the extrusion of the plastic, the design of a machine head mould and the like, wherein the most important is a final shaping device-mould in the extrusion process of the plastic wire. The geometric shape, the design and the size of the mechanism, the temperature, the pressure and the like of the die directly determine the success or failure of wire processing. Therefore, the design, the selection and the heat preservation measures of the mold of any plastic wire product are highly valued.

The extrusion pipe type die for the cable plastic insulation and the sheath comprises a die sleeve and a die core, wherein the extrusion end of the die core forms a tubular bearing part, the cable core penetrates through the tubular bearing part, a space for plastic extrusion is formed between the die sleeve and the die core, plastic is not directly pressed on a wire core but moves forwards along the tubular bearing part due to the existence of the tubular bearing part of the die core, the tubular plastic is firstly formed and then is coated on the wire core of the wire through stretching, the extrusion pipe type die is convenient to match, the operation is simple, the eccentric adjustment is easy, and the eccentricity is not caused greatly. However, when extruding some large cables, especially metal armoured cables, the temperature of the tubular bearing part of the mould core at one side, which is deviated by the centre of the cable core, is reduced, so that the surface of the produced cable insulation or sheath is broken or convex-concave due to the sudden cooling of plastic, and the mould is seriously damaged. In order to solve the problems, the wire inlet position is often adjusted by using a guide wheel with lifting and left-right adjusting functions before the cable core enters the die in production, so that the phenomenon is avoided, but the method has certain uncontrollability in adjustment, accidents are often caused in the production process, and the product quality is affected.

Disclosure of Invention

Aiming at the problems existing in the prior art, the utility model provides a die for extruding cable plastic insulation or sheath, which solves the problems of cable insulation or sheath surface fracture, convex-concave phenomenon and die damage which possibly occur in the extrusion process of a traditional cable extrusion tube type die package.

The utility model is realized in such a way, a mould for extruding cable plastic insulation or sheath comprises a mould sleeve and a mould core, wherein the mould core comprises a tubular bearing part, the tubular bearing part is a part of the mould core, the tubular bearing part is provided with a pipe hole, and the inner diameter of the pipe hole is D1, and the mould is characterized in that: the cable core extrusion molding device comprises an inner mold, wherein the inner mold is fixed on a mold core through a pin hole, the inner mold is provided with a mold hole, the mold hole is coaxial with the pipe hole, an extruded cable core passes through the mold hole and the pipe hole in sequence, and the inner diameter D3 of the mold hole is smaller than D1.

In the above technical solution, preferably, the inner mold is detachably mounted to the mold core.

In the above technical scheme, preferably, the die core is provided with a front end for the cable core to enter in the extrusion processing process and a rear end for the cable core to extend out in the extrusion processing process, the tubular bearing portion is arranged at the front end of the die core, the rear end of the die core is provided with a threaded hole, and the inner die is assembled in the threaded hole through threads.

In the above technical solution, preferably, D1-d3=4-6 mm.

In the above technical solution, preferably, the edge of the hole of the die is in a rounded structure.

The utility model has the technical effects and advantages that:

1. the novel extrusion die comprises a die sleeve and a die core, wherein an inner die for radially limiting a cable core is arranged in the die core, and therefore the cable core is prevented from being deviated in the extrusion process.

2. The inner die is used for radially limiting the cable core in the die core, so that the phenomenon that the cable core is deviated to cause cable insulation or sheath surface breakage or convex-concave phenomenon is effectively prevented, and the quality and consistency of cable products are improved.

3. The novel die is designed to enable the cable core to be more stable in the extrusion process, and the cable core deviation problem possibly occurring in the traditional die package is avoided, so that the problems of cable insulation or sheath surface fracture or convex-concave phenomenon and die damage caused by cable core deviation are thoroughly solved.

4. The die is simple and convenient to operate, realizes accurate radial limiting of the cable core through the use of the inner die, reduces uncontrollability in the production process, and improves production efficiency and product quality. Meanwhile, the die is suitable for extruding large cables, particularly metal armored cables, solves the problem of cable core deflection possibly occurring in the extrusion process of the traditional die package, and has higher practical application value.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

Detailed Description

The present utility model will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

In order to solve the problems of cable insulation or sheath surface breakage, convex-concave phenomenon and mold damage which possibly occur in the extrusion process of the traditional cable extrusion pipe type mold package, the utility model particularly provides a mold for cable plastic insulation or sheath extrusion, which can prevent a cable core from shifting in the extrusion process, avoid the cable insulation or sheath surface breakage or convex-concave generation and improve the cable quality. For further explanation of the structure of the present utility model, the detailed description is as follows in connection with the accompanying drawings:

referring to fig. 1, a die for extruding a plastic insulation or sheath of a cable comprises a die sleeve 1 and a die core 2. The mould core comprises a tubular bearing part 2-1, the tubular bearing part is a part of the mould core, the tubular bearing part is provided with a pipe hole, and the inner diameter of the pipe hole is D1. The mold core material is selected based on the basic principles of resource, cost and service life requirements, has good heat resistance, wear resistance and corrosion resistance, and is easy to cut, weld, rust and the like. For the structural characteristics of the extrusion pipe type mold core, the long nozzle sizing region is a thin-wall circular pipe, heat treatment is not easy to perform generally, the wear resistance requirement is strict, and the mold core is particularly used for insulating extrusion and is made of multipurpose wear-resistant alloy steel (such as 30 CrMoAl). The wear resistance requirements of the die sleeve material can be reduced, and the machining precision must be improved, and the die sleeve is often made of 45 steel. The inner surfaces of the mold core and the mold sleeve are required to be polished by chrome plating to be equal to V0.05.

The cable core extrusion device comprises an inner die 3, wherein the inner die is fixed on a die core through a pin hole, the inner die is provided with a die hole 3-1, the die hole is coaxial with a pipe hole, an extruded cable core sequentially passes through the die hole and the pipe hole, the inner diameter D3 of the die hole is smaller than D1, and in the embodiment, D1-D3=4-6 mm.

The internal mold is detachably arranged on the mold core. In this embodiment, specifically, the mold core is equipped with the front end that the cable core got into in extrusion processing process and the rear end that the cable core stretches out in extrusion processing process, and the front end of mold core is located to tubular bearing footpath, and the rear end of mold core is equipped with the screw hole, and the centre form passes through the screw thread and joins in marriage and adorns in the screw hole.

The edge of the die hole is in a rounded corner structure.

After the materials are determined, the dimensions of each part are properly designed according to the process rationality and the processing possibility, and are as follows:

1) Angle of taper outside the mold core +.a: according to the design of the machine head structure and the plastic flow characteristic, the cone angle is controlled below 45 degrees, the smaller the angle is, the smoother the flow passage is, the smaller the mutation is, and the plastic layer structure is beneficial.

2) Maximum diameter D5 of core outer cone: the size is determined by the size of the mold core holder (or mold core seat), strict anastomosis is required, a 'front stage' cannot appear, a 'back stage' cannot appear, otherwise, a glue storage dead angle is caused, and the plastic layer tissue and the surface quality are directly affected.

3) Maximum diameter D6 of core cone: the dimension is mainly determined by the processing conditions and the wall thickness of the mold core stud, and on the premise of guaranteeing the screw thread strength and the wall thickness, the larger D6 is, the better the D6 is, so that threading is facilitated.

4) Mold core inner diameter D1: the structure size with the greatest influence on extrusion quality is designed according to the structure characteristics of the wire core and the size thereof. The general design is as follows:

taking d1=d regularly with smaller cable core size _{Cable core} +(0.05~2mm)

Taking d1=d for larger and irregular cable core size _{Cable core} +(3~6mm)

Usually, the processing is convenient, and the size of the die core aperture is serialized, so that the multi-die core aperture d is an integer.

5) Minimum diameter D2 of core outer cone: d2 is actually the size of the outlet port thickness of the mould core, the port thickness delta 1 cannot be too thin, otherwise the service life is affected; the plastic melt flow channel is not too thick, otherwise, the plastic melt flow channel is suddenly changed, a vortex area is formed, fluctuation of extrusion pressure is caused, dead angles are easily formed, the quality of a plastic layer is affected, and the wall thickness of an outlet port of a general mold core is preferably controlled to be 0.5-1.5 mm.

6) Mould core sizing area length L2: l2 determines the stability of the core passing through the core, but cannot be designed too long, otherwise, it will cause processing difficulty, the necessity in the process is not large, generally l2= (0.5-1.5) D1, and the lower limit is selected when the core aperture D1 is large, otherwise, the D1 value is small to take the upper limit, the lower limit is taken by the core for extruding the sheath, and the upper limit is taken when extruding the insulation.

7) Die sleeve sizing area length L1: the size is usually determined according to the molding characteristics of plastic and the length L2 of the outer cylinder of the sizing area of the mold core, and is generally designed to be L1=L2- (2-6) mm, and the lower limit (namely the upper limit of the subtraction value) of the thickness of the extrusion insulation (sheath) is taken when the thickness is small; otherwise, the other way round.

8) The angle b of the inner taper of the die sleeve is extremely important, and the existence of the angle difference b-a can be the gradual shrinkage of the section of the plastic flow passage, and the gradual increase of the pressure during extrusion leads to compact plastic layer tissue and compact combination of the plastic and the wire core. The angle difference is small, the pressure is small, and the resistance is also small; the larger the angle difference is, the larger the pressure is, the tighter the plastic and the wire core are wrapped, but the resistance is also large, the glue yield is reduced, and the productivity is reduced. The angle b of the extrusion pipe type die is smaller, the extrusion pipe is formed, and the sheath can be loosened. The angle b=20-45 degrees is generally smaller than the corresponding angle a outside the mold core, the angle a=10-30 degrees is also smaller, and the value of the angle b-a is smaller, so that the resistance of forward flow of the material flow is small, the plastic flow and the pipe forming are facilitated, and the productivity is also improved.

9) The inner die is made of alloy steel 30CrMoAl, the surface polishing is 6, the length of L6 can be 8 mm-20 mm according to the size of the die, the upper limit is taken when D1 is large, and the lower limit is taken otherwise; the depth L5 of the inner die seat is 2mm, the wall thickness delta 3 of the inner die is determined according to D1, and the D1-D3= (4-6) mm is ensured; the inlet and outlet of the internal mold need to be in arc transition, so that the cable core is prevented from being scratched; the depth delta 2 of the pin hole of the fixed internal mold is 2.0 mm, and the width is 2.0 mm;

10 D4, D5, D6, D7 are determined by the dimensions of the handpiece itself and are not described herein.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The utility model provides a cable plastics is insulating or mould for sheath extrusion, includes die sleeve and mold core, wherein, the mold core includes the tubulose and holds footpath portion, the tubulose holds footpath portion and is a part of mold core, and the tubulose is held footpath portion and is equipped with the tube hole, and tube hole internal diameter is D1, its characterized in that: the cable core extrusion molding device comprises an inner mold, wherein the inner mold is fixed on a mold core through a pin hole, the inner mold is provided with a mold hole, the mold hole is coaxial with the pipe hole, an extruded cable core passes through the mold hole and the pipe hole in sequence, and the inner diameter D3 of the mold hole is smaller than D1.

2. The die for extrusion of cable plastic insulation or jackets as set forth in claim 1, wherein: the inner die is detachably mounted on the die core.

3. The die for extrusion of cable plastic insulation or jackets as set forth in claim 2, wherein: the die core is provided with a front end for a cable core to enter in the extrusion processing process and a rear end for the cable core to stretch out in the extrusion processing process, the tubular bearing part is arranged at the front end of the die core, the rear end of the die core is provided with a threaded hole, and the inner die is assembled in the threaded hole through threads.

4. A cable plastics insulation or sheath extrusion die according to claim 3, wherein: d1-d3=4-6 mm.

5. A cable plastics insulation or sheath extrusion die according to claim 3, wherein: the edge of the die hole is in a rounded corner structure.