WO2017067298A1

WO2017067298A1 - Wire and cable sheath extrusion method and positive displacement extruder

Info

Publication number: WO2017067298A1
Application number: PCT/CN2016/094601
Authority: WO
Inventors: 胡光南; 黄冬莲
Original assignee: 深圳市联嘉祥科技股份有限公司
Priority date: 2015-10-20
Filing date: 2016-08-11
Publication date: 2017-04-27
Also published as: CN106584802A; CN106584802B

Abstract

A wire and cable sheath extrusion method and a positive displacement extruder. The wire and cable sheath extrusion method comprises: using three geometric shaped members to create a closed space; using two continuously rotating members to continuously change the volume of the closed space; when the volume increases, feeding molten sheath plastic; and when the volume decreases, pressing, exhausting air, plasticizing and extruding the molten sheath plastic to wrap the periphery of a wire or cable to form a sheath. The positive displacement extruder comprises a feeding cylinder (1), an extrusion part (2), an injection nozzle (3) and an extrusion die (4) that are communicated sequentially. The extrusion part comprises a stator (21), and a drive rotor (22) and a driven rotor (23) arranged in the inner cavity of the stator (21) and engaged with each other. The stator (21) and the two rotors (22, 23) create a closed space. The two rotors (22, 23) rotate to continuously change the volume. The wire and cable sheath extrusion method and the positive displacement extruder can increase the density of the sheath, improve the strength and toughness thereof, and shorten the process of thermal mechanical action.

Description

Title of Invention: Extrusion Method of Wire and Cable Sheath and Volumetric Extrusion Machine

[0001] The present invention relates to the technical field of plastic sheath processing of wire and cable, and more particularly to an extrusion method of a wire and cable sheath and a volumetric extruder.

Background technique

[0002] Generally, the conductive wire core of the wire and cable has an insulating sheath for protection and insulation. The most commonly used sheath material is plastic. For cables that generally require high temperature resistance, rubber materials are used for sheathing. .

[0003] Taking a plastic material sheath as an example, the plastic material is coated outside the conductive core. The existing method is to use a screw extruder to heat and melt the plastic raw material and then extrude and wrap the outer circumference of the continuously moving conductive core. Then, it is cooled and solidified to form a strong insulating sheath on the outer circumference of the conductive core. The screw extruder comprises a barrel, a screw sleeve and a nozzle, the screw sleeve has a rotating screw built therein, and an electric heating device is arranged on the outer wall of the sleeve, and the plastic raw material entering from the barrel is melted and plasticized by the electric heating device, and is rotated by the rotating screw. Pressing, friction, towing, the same is transported from the outlet end of the sleeve to the nozzle, the melt (ie, the plastic after melt plasticization). The conveying force comes from the friction between the melt and the surface of the machine. The thermomechanical action is longer. It requires a large amount of mechanical energy to be consumed. Moreover, the frictional force of the melt surface is transmitted to the inside in the form of shear stress, which is not conducive to the discharge of gas introduced from the cylinder, and may even cause secondary voids, which may affect the compactness of the rubber compound. Sex, reduce the strength and toughness of the sheath. In particular, the special cable for charging piles of electric vehicles is required to have the characteristics of resistance to automobile rolling and frequent bending. Therefore, the strength and toughness of the cable sheath are higher, and the conventional extrusion equipment is difficult to meet the processing requirements.

[0004] In order to solve the above problems, the existing related patents (such as the method and equipment for plasticizing and transporting polymeric materials based on tensile rheology), patent number 200810026054.X), propose a new method. And equipment, by applying a normal stress to the material by changing the volume of the equipment, so that it is compacted, vented, and melt-plasticized during transportation, but the volumetric change device provided by the patent is a conventional vane pump, the blade thereof The geometry formed by the combination with the rotor is enthalpy change in rotation, and it cannot be "determined". If it is "determined", it must be fixed in the rotor groove, or it cannot rotate, or the volume will not Change, so the current solution is not volumetric extrusion. In addition, the vane pump is actually common in gas or low viscosity Liquids, such as water and oils, are not suitable for higher viscosity greases and molten plastics, especially at low speeds, because the change in volume is achieved by sliding the blades in the rotor slots. The sealing between adjacent chambers is achieved by the pressing and pressing between the blades and the inner wall of the stator. The pressing force is derived from the centrifugal force of the rotation of the blades. The pump flow rate of the conveying compound is usually small, and the rotation speed is very high. Low, the centrifugal force of rotation is very small, which is not enough to overcome the resistance of the viscous compound between the blade and the rotor slot and the stator wall, and it is impossible to form an effective seal, that is, the device is not practical.

technical problem

[0005] It can be seen that there are existing technologies in the prior art that the density, strength and toughness of the wire and cable sheath obtained by extrusion using the existing solution are insufficient to meet the technical requirements of the cable for electric vehicle charging piles.

Problem solution

Technical solution

[0006] In view of the technical problem that the density, strength and toughness of the wire and cable sheath obtained by extrusion using the existing solution existing in the prior art are insufficient to meet the cable requirements of the electric vehicle charging pile, a wire and cable sheath is provided. The extrusion method and the volumetric extruder realize true volumetric extrusion and conveying, shortening the thermo-mechanical action process, saving energy consumption, effectively increasing the density of the sheath, and improving the strength and toughness of the sheath. It is enough to meet the cable requirements for electric vehicle charging piles.

In one aspect, the present invention provides a method of extruding a wire and cable sheath, comprising the steps of:

[0008] enclosing a certain enclosed space by three members having a fixed geometry;

[0009] the volume of the enclosed space is constantly changed by the continuous rotation of two of the three members having a fixed geometry, when the volume is changed from small to large, into the molten sheath plastic, when The volume is changed from large to small, and the molten sheath plastic is applied with a normal stress, and the molten sheath plastic is extruded, vented, plasticized, and conveyed and wrapped around the outer circumference of the wire and cable to form a sheath.

[0010] In another aspect, the present invention also provides a volumetric extruder for implementing the above-described method for extruding a wire and cable sheath, comprising: a barrel that is sequentially connected, an extruded part, an injection nozzle, and an extrusion die;

[0011] the cartridge includes a hopper and a melt cylinder with an electric heating element; the extrusion member is of a volumetric type, comprising a stator and an active rotor and a driven rotor disposed in the inner cavity of the stator and intermeshing each other The inner cavity of the stator and the outer circumference of the active rotor and the driven rotor enclose a closed space, and the volume of the closed space is varied during the continuous rotation of the driven rotor by the active rotor Constantly changing Where the volume is increased, a side of the stator is provided with a feed port communicating with the melt cylinder for incorporating molten sheath plastic, where the volume is reduced, the stator An extrusion port communicating with the injection nozzle is disposed on the side wall for conveying and extruding the molten sheath plastic to the extrusion mold, so that the extrusion mold wraps the molten sheath plastic Forming a sheath on the outer circumference of the wire and cable; wherein, in the process of transporting from the portion where the volume is increased to the portion having the reduced volume, the molten sheath plastic is pressed, exhausted, and plasticized .

[0012] Optionally, the inner cavity of the stator is a cylindrical cavity enclosing the active rotor and the outer circumference of the driven rotor

[0013] Optionally, the active rotor and the driven rotor are a conjugate active waist rotor and a driven waist rotor, and the active waist rotor is driven by a pair of identical intermeshing gear pairs. The driven waist rotor rotates in the opposite direction at the same speed.

[0014] Optionally, the profile forming the active waist rotor and the driven waist rotor is composed of a plurality of segments of a smoothly connected curve, including a circular arc line, a tapered line, and a cycloid; The cavity is a cylindrical cavity enclosing the active waist rotor and the driven waist rotor profile, the cylindrical cavity being composed of two cylindrical faces larger than a semicircle.

[0015] Optionally, the active rotor and the driven rotor are a pair of intermeshing conjugated circular arc gears, including a driving gear and a driven gear driven by the driving gear to rotate in opposite directions.

[0016] Optionally, the stator is an oblong cylindrical stator, and the inner cavity of the stator is a cylindrical cavity enclosing the driving gear and the outer contour of the driven gear, and the cylindrical cavity Consists of two semi-cylindrical faces and two flat faces

The two sections of the plane are respectively connected between the two sections of semi-cylindrical surfaces.

Advantageous effects of the invention

Beneficial effect

[0017] One or more technical solutions provided in the present invention have at least the following technical effects or advantages:

[0018] Real volumetric extrusion and conveying are achieved by using simple methods and equipment, which shortens the thermomechanical process, saves energy consumption, effectively increases the density of the sheath, and improves the strength and toughness of the sheath.

, Providing advanced sheath processing equipment for the processing and manufacturing of electric vehicle charging cables, contributing to the popularization of new energy vehicles.

Brief description of the drawing DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings to be used in the embodiments or the prior art description will be briefly described below, and obviously, in the following description The drawings are merely examples of the invention, and those skilled in the art can also obtain other drawings based on the drawings provided without any inventive work.

1 is a schematic cross-sectional view of a volumetric extruder according to an embodiment of the present invention;

2 is a schematic structural view of a rotor and a gear pair of a volumetric extruder according to an embodiment of the present invention; [0022] FIG. 3 is a conjugate of a rotor of a volumetric extruder according to an embodiment of the present invention; Schematic diagram of the waist rotor;

4 is a schematic structural view of a circumscribed circular arc gear of a positive displacement extruder according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0024] Embodiments of the present invention provide a method for extruding a wire and cable sheath, which solves the problem that the density, strength and toughness of the wire and cable sheath obtained by extrusion using the existing solution existing in the prior art are insufficient to satisfy the electric vehicle. The technical problems required for charging pile cables realize true volumetric extrusion and conveying, shortening the thermo-mechanical action process, saving energy consumption, effectively increasing the density of the sheath, and improving the strength and toughness of the sheath. Meet the cable requirements for electric vehicle charging piles.

[0025] The technical solution of the embodiment of the present invention is to solve the above technical problem, and the general idea is as follows:

The present invention provides a method of extruding a wire and cable sheath, comprising the steps of: enclosing a certain enclosed space by three members having a fixed geometry; by means of the three members having a fixed geometry The two members continuously rotate to change the volume of the closed space. When the volume is changed from small to large, it is incorporated into the molten sheath plastic. When the volume is changed from large to small, the normal stress is applied to the molten sheath plastic. And extruding, venting, plasticizing, and conveying the molten sheath plastic to wrap around the outer circumference of the wire and cable to form a sheath. Further, a volumetric extruder is provided for carrying out the method, comprising: a barrel that is sequentially connected, an extrusion part, an injection nozzle, and an extrusion die; the barrel includes a hopper and a melting barrel with an electric heating element The extruded component is of a volumetric type comprising a stator and an active rotor and a driven rotor disposed in the inner cavity of the stator and intermeshing; the inner cavity of the stator and the active rotor and the driven rotor The outer periphery of the sub-environment encloses an enclosed space, and during the continuous rotation of the driven rotor, the volume of the closed space changes continuously; at the portion where the volume is increased, the stator The side wall is provided with a feed port communicating with the melt cylinder for incorporating the molten sheath plastic, and at the portion where the volume is reduced, the side wall of the stator is provided with the injection nozzle An extrusion port for conveying and extruding the molten sheath plastic to the extrusion mold, so that the extrusion mold wraps the molten sheath plastic around a periphery of the wire and cable to form a sheath; The molten sheath plastic is pressed, vented, and plasticized during transport from the portion where the volume is increased to the portion where the volume is reduced.

[0027] It can be seen that in the embodiment of the present invention, real volumetric extrusion and transportation are realized by adopting a simple method and device, the thermomechanical action flow is shortened, energy consumption is saved, and the density of the sheath is effectively increased. It has improved the strength and toughness of the sheath, and provided advanced sheath processing equipment for the processing and manufacturing of electric vehicle charging cables, contributing to the popularization of new energy vehicles.

[0028] In order to better understand the above technical solutions, the above technical solutions will be described in detail in conjunction with the drawings and specific embodiments. It should be understood that the specific features of the embodiments and embodiments of the present invention are the technical solutions of the present application. The detailed description, rather than the limitation of the technical solution of the present application, can be combined with each other in the embodiments of the present invention and the technical features in the embodiments without conflict.

[0029] As shown in FIG. 1, the present invention provides a volumetric extruder comprising: a barrel 1 in sequence, an extruded part 2, an injection nozzle 3, and an extrusion die 4;

[0030] The cartridge 1 comprises a hopper 11 and a melt cylinder 12 with an electric heating element 121; the extruded part 2 is of a volumetric type comprising a stator 21 and an active rotor 22 and a rotor disposed in the inner cavity of the stator 21 and intermeshing each other The inner rotor of the stator 2 and the outer circumference of the driven rotor 22 and the driven rotor 23 enclose a closed space. During the continuous rotation of the driven rotor 23 by the active rotor 22, the volume of the closed space follows. Constantly changing; at the portion where the volume is increased, the side wall of the stator 21 is provided with a feed port 211 communicating with the melt cylinder 12 for incorporating the molten sheath plastic, in the portion where the volume is reduced, The side wall of the stator 21 is provided with an extrusion port 212 communicating with the injection nozzle 3 for conveying and extruding the molten sheath plastic to the extrusion mold 4, so that the extrusion mold 4 will be the molten sheath plastic. Wrapped around the outer circumference of the wire cable to form a sheath; wherein, during transport from the portion where the volume is increased to the portion where the volume is reduced, the rotation of the two rotors 22, 23 is performed on the molten sheath plastic Extrusion, venting, plasticizing. [0031] Specifically, the inner cavity of the stator 21 is a cylindrical cavity enclosing the outer circumference of the active rotor 22 and the driven rotor 23.

[0032] In one embodiment of the present application, as shown in FIG. 1, the active rotor 22 and the driven rotor 23 are a conjugate active waist rotor 22a and a driven waist rotor 23a. Next, as shown in FIG. 2, which is a schematic cross-sectional view of the volumetric extruder shown in FIG. 1 taken along the AA direction, the active waist rotor 22a drives the driven waist rotor 23a through a pair of identical intermeshing gear pairs 24. Reverse rotation at the same speed. The volumetric extruder further includes an electric motor 25 coupled to the active waist rotor 22a and driving the rotation thereof. The gear pair 24 includes a first gear 241 coupled to the active waist rotor 22a and a first connection to the driven waist rotor 23a. The two gears 242, the motor 25 is also coupled to the first gear 241 and driven to rotate in synchronization with the active waist rotor 22a to cause the second gear 242 to interlock, thereby causing the driven waist rotor 23a to rotate. Specifically, the profile constituting the active waist rotor 22a and the driven waist rotor 23a is composed of a plurality of smoothly connected curves including a circular arc line, a progressive line, and/or a cycloid. As shown in FIG. 3, the inner cavity of the stator 21 is a cylindrical cavity enclosing the outer contour of the active waist rotor 22a and the driven waist rotor 23a, and the cylindrical cavity is composed of two cylindrical faces 21 which are larger than a semicircle. 1, 21-2 constitutes. The feed port 211 and the squeeze port 212 are disposed at the junction of the two cylindrical faces for optimum layout.

[0033] When the active rotor 22 and the driven rotor 23 are the conjugate active waist rotor 22a and the driven waist rotor 23a, the working principle of the volumetric extruder is: the active waist rotor 22a reverses the needle direction Rotating, the driven waist rotor 23 & the same direction of rotation in the direction of the needle, in the position shown in Figs. 1 and 3, that is, the maximum radius point of the upper end of the driven waist rotor 23a and the inner cavity surface of the stator 21 In contact, the stator 21, the active waist rotor 22a and the driven waist rotor 23a enclose a cavity c above the active waist rotor 22a, the volume of the cavity c being the smallest; with the active waist rotor 22a and the slave The continuous rotation of the moving waist rotor 23a, the volume of the cavity c is continuously increased, and the molten sheath plastic in the hopper 11 is sucked into the cavity c, and is transferred to the active waist shape as the two rotors 22a, 22b are continuously rotated. In the closed cavity d below the rotor 22a and the driven waist rotor 23a, when the volume of the cavity d is continuously reduced, the sheath plastic is subjected to compressive stress to be continuously compacted, and the bubbles therein are eliminated, and finally from the injection nozzle 3 Injection injection into the jacket 40 within the mold. The motor 25 is a servo motor, and the rotation speed can be adjusted as needed to control the flow rate of the injected plastic.

[0034] In another embodiment of the present application, as shown in FIG. 4, the driving rotor 22 and the driven rotor 23 are a pair of intermeshing conjugated arc gears including a driving gear 22b and a driving gear. 22b drives the counter-rotating driven gear 23b. The stator 21 is an oblong cylindrical stator, and the inner cavity of the stator 21 is a cylindrical cavity enclosing the driving gear 22b and the driven gear 23b. The cylindrical cavity is composed of two semi-cylindrical faces 21-3, 21 -4 and Two sections of planes 21-5, 21-6 are formed, and the two sections of planes 21-5, 21-6 are respectively connected to two sections of semi-cylindrical surfaces 21-

3. Between one side of 21-4. The structure of the embodiment shown in Fig. 1 differs from the structure of the two rotors described above only in the shape and structure of the two rotors, and the working principle is similar, and will not be described herein. Of course, in the specific implementation process, a pair of intermeshing conjugated arc gears as shown in Fig. 4 is used as the rotor. The rotor profile has good machining process, standard arc gears can be used, the process and equipment are mature, and the structure is simple. The selection cost is low, the accuracy is easy to guarantee, and good processing quality can be obtained.

[0035] Based on the same inventive concept, an embodiment of the present invention further provides a method for extruding a wire and cable sheath implemented on the above-described volumetric extruder, comprising the steps of: enclosing a certain component with three fixed geometries Enclosed space; the volume of the enclosed space is constantly changed by the continuous rotation of two of the three members having a fixed geometry, and when the volume is changed from small to large, the molten sheath plastic is incorporated into The volume is changed from large to small, and the molten sheath plastic is applied with a normal stress, and the molten sheath plastic is extruded, vented, plasticized, and conveyed and wrapped around the outer circumference of the wire and cable to form a sheath. Wherein, the three components having a fixed geometry, that is, the stator 21, the active rotor 22 and the driven rotor 23, the closed space includes a cavity c and a cavity d, specifically, when the volume of the cavity c is increased from small to large吋Incorporating the molten sheath plastic, when the volume of the cavity d is changed from large to small, the normal stress is applied to the molten sheath plastic, and the molten sheath plastic is extruded, exhausted, plasticized, and conveyed and extruded. A sheath is formed on the outer circumference of the wire and cable. In summary, the method is consistent with one or more embodiments of the above-described extruder, and will not be further described herein.

[0036] In summary, the extrusion method and the volumetric extruder of the wire and cable sheath embodying the present invention realize true volumetric extrusion and transportation by a simple method and equipment, and shorten the thermomechanical The action process saves energy consumption, effectively increases the density of the sheath, improves the strength and toughness of the sheath, and provides advanced sheath processing equipment for the processing and manufacturing of electric vehicle charging cables, in order to promote the popularization of new energy vehicles. Made a contribution.

[0037] While the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they are aware of the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

[0038] It will be apparent to those skilled in the art that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and the modifications of the invention

Claims

Claim

[Claim 1] A method for extruding a wire and cable sheath, comprising the steps of:

Enclosing a certain enclosed space by means of three members having a fixed geometry;

The volume of the enclosed space is constantly changed by the continuous rotation of two of the three members having a fixed geometry, when the volume is changed from small to large, into the molten sheath plastic, when the volume is large The reduced enthalpy applies a normal stress to the molten sheath plastic, and the molten sheath plastic is extruded, vented, plasticized, and conveyed and wrapped around the outer circumference of the wire and cable to form a sheath.

[Claim 2] A volumetric extruder for carrying out the method of extruding a wire and cable sheath according to claim 1, wherein the volumetric extruder comprises: a barrel that is sequentially connected, an extruded part, Injection nozzle and extrusion mold;

The cartridge includes a hopper and a melt cylinder with an electric heating element; the extrusion member is of a volumetric type, comprising a stator and an active rotor and a driven rotor disposed in the inner cavity of the stator and intermeshing; The inner cavity of the stator encloses a closed space with the outer circumferences of the active rotor and the driven rotor, and the volume of the closed space changes continuously during the continuous rotation of the driven rotor by the active rotor. At a portion where the volume is increased, a side wall of the stator is provided with a feed port communicating with the melt cylinder for incorporating a molten sheath plastic, where the volume is reduced. An extrusion port communicating with the injection nozzle is disposed on a side wall of the stator for conveying and extruding the molten sheath plastic to the extrusion mold, so that the extrusion mold will protect the molten mold The sleeve is wrapped around the outer circumference of the wire and cable to form a sheath; wherein, in the process of transporting from the portion where the volume is increased to the portion where the volume is reduced, the molten sheath plastic is squeezed, exhausted, Plastic treatment

[Claim 3] The volumetric extruder according to claim 2, wherein the inner cavity of the stator is a cylindrical cavity enclosing the active rotor and the outer periphery of the driven rotor.

[Claim 4] The volumetric extruder according to claim 3, wherein the active rotor and the driven rotor are conjugate active waist rotors and driven waist rotors, the active The waist rotor drives the driven waist rotor to rotate in reverse at the same speed by a pair of identical intermeshing gear pairs. The volumetric extruder according to claim 4, wherein the profile constituting the active waist rotor and the driven waist rotor is composed of a plurality of segments of a smoothly connected curve, including a circular arc, a progressive a line and/or a cycloid; the inner cavity of the stator is a cylindrical cavity enclosing the active waist rotor and the driven waist rotor outer circumference, the cylindrical cavity being larger than a semicircle by two segments Cylindrical surface.

The volumetric extruder according to claim 3, wherein said active rotor and said driven rotor are a pair of intermeshing conjugated arc gears including a drive gear and driven by said drive gear The driven gear that rotates in the opposite direction.

The volumetric extruder according to claim 6, wherein said stator is an oblong cylindrical stator, and said inner cavity of said stator is a column enclosing said driving gear and said driven gear outer contour The face cavity is composed of two semi-cylindrical faces and two sections of planes, and the two sections of planes are respectively connected between the two sections of semi-cylindrical faces.