Low-temperature extrusion die for cable insulating layer

Abstract

The invention relates to the technical field of cable insulating layer extrusion equipment, provides a low-temperature extrusion die for a cable insulating layer, and solves the technical problem of influence on material flow due to accumulation of impurities and residues on the surfaces of parts in the die during low-temperature extrusion of the existing cable insulating layer. The low-temperature extrusion die for the cable insulating layer comprises an outer die, a die core and a die sleeve, the die core is inserted into the outer die, the die sleeve is fixed at the front end of the outer die, and a cavity is formed among the outer die, the die core and the die sleeve. An inner sleeve and a middle pipe which are coaxially arranged are inserted into the mold core from inside to outside, the front end of the inner sleeve extends out of the mold core and is arranged at an interval with an extrusion opening of the mold sleeve, the middle pipe is driven by a rotation driving unit to rotate around the inner sleeve, and a spiral blade is arranged at the front end of the middle pipe; one end of the spiral blade is accommodated in the mold core, and the other end of the spiral blade extends out of the mold core and is spaced from the opening in the front end of the inner sleeve.

Description

Technical Field

[0001] The present invention relates to the technical field of wire and cable insulation layer extrusion equipment, and particularly relates to a low-temperature extrusion die for wire and cable insulation layers. Background Art

[0002] Existing wire and cable insulation layer extrusion dies mostly adopt semi-extrusion tube dies. The semi-extrusion tube die is generally the same as the extrusion tube die. A die nozzle extending towards the extrusion outlet and set for sizing is provided at the end of the die core. Only the length of the die nozzle is shorter than that of the extrusion tube die. The die nozzle is received in the die sleeve and is spaced from the extrusion outlet. The insulation layers of some types of wires and cables need to be extruded at low temperature. Low-temperature extrusion can avoid the high-temperature decomposition of thermosensitive materials, maintain their chemical stability and insulation performance, and can also reduce the difference in material cooling shrinkage, enhancing the flexibility and anti-cracking ability of the insulation layer. However, there are the following problems: the temperature in the die fluctuates, resulting in fluctuations in material flow and shear rate, affecting the surface quality and wrapping performance of the insulation layer. For this reason, the applicant designed a fixed die nozzle - movable die core structure. By horizontally moving the die core, the gap of the tapered cavity between the die core and the die sleeve is adjusted to improve the above problems. However, it was unexpectedly found that there are the following problems during actual use. For some products that need to be extruded and formed at low temperature, when the machine is turned on for 8 hours or 12 hours every day and continuously produced for multiple days, especially for more than half a month, for the wires and cables produced later, the surface quality and wrapping performance of their insulation layers become worse. After removing the die, it is found that refractory impurities and residues will accumulate at the annular pores between the die nozzle and the die core. The horizontal movement of the die core or the flow of the material cannot completely push the impurities and residues away from the die nozzle. During the repeated horizontal movement of the die core, the impurities and residues will accumulate on the surface of the die nozzle far from the die core, increasing in thickness and affecting the material flow.

[0003] For this reason, we propose a low-temperature extrusion die for wire and cable insulation layers. Summary of the Invention

[0004] (1) Technical Problems to be Solved

[0005] The present invention provides a low-temperature extrusion die for wire and cable insulation layers, which solves the technical problem that the accumulation of impurities and residues on the surfaces of internal parts of the existing low-temperature extrusion of wire and cable insulation layers affects the material flow.

[0006] (2) Technical Solutions

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] A low-temperature extrusion die for cable insulation layer, comprising an outer die, a die core and a die sleeve. The die core is inserted into the outer die, and the die sleeve is fixed to the front end of the outer die. A cavity is formed between the outer die and the die core and the die sleeve. It is characterized in that: the die core is driven by a transverse driving unit to translate axially along the die sleeve. An inner sleeve and an intermediate tube are coaxially inserted into the die core from the inside out. The front end of the inner sleeve extends out of the die core and is spaced from the extrusion outlet of the die sleeve. The intermediate tube is driven by a rotation driving unit to rotate around the inner sleeve. A spiral blade is provided at the front end of the intermediate tube. One end of the spiral blade is received in the die core, and the other end extends out of the die core and is spaced from the front end opening of the inner sleeve.

[0009] Further, the die core is coaxially fixed to the end of an outer sleeve tube, and the outer sleeve tube is coaxially supported in the outer die. The inner sleeve includes a first thin tube section and a first thick tube section connected coaxially. The intermediate tube includes a second thin tube section and a second thick tube section arranged coaxially. A first thin tube section and a second thin tube section are coaxially inserted into the die core from the inside out. A first thick tube section and a second thick tube section are coaxially inserted into the outer sleeve tube from the inside out. The first thick tube section is fixedly connected to the outer die through a support frame. The second thick tube section is rotationally matched with the first thick tube section through a bearing and is driven by a rotation driving unit to rotate around the first thick tube section. The outer sleeve tube is driven by a transverse driving unit to translate axially along the die sleeve.

[0010] Even further, the support frame includes a support sleeve and a support plate. Support plates are respectively fixed at both ends of the support sleeve. The support sleeve is sleeved outside the first thick tube section and is threadedly connected with a second locking bolt. The second locking bolt presses and fixes the first thick tube section. A pair of screw rods are connected to the outer die. Both ends of the support plate are penetrated by the screw rods and are clamped and fixed by a pair of first locking nuts.

[0011] Further, the end of the outer sleeve tube exposed outside the outer die is connected to a transverse driving unit, and the transverse driving unit is specifically an electric push rod.

[0012] Further, the end of the second thick tube section exposed outside the outer sleeve tube is connected to a driven gear, and the driven gear meshes with the driving gear at the output end of the rotation driving unit. The rotation driving unit is specifically a servo motor.

[0013] Further, the end of the first thick tube section close to the first thin tube section is rotationally matched with the second thick tube section through a first bearing. The other end of the first thick tube section is rotationally matched with an adapter ring through a second bearing. The adapter ring is coaxially fixed to the second thick tube.

[0014] Further, a guide sleeve is inserted between the outer sleeve tube and the outer die. The guide sleeve and the outer sleeve tube are slidably matched through splines and spline grooves.

[0015] Further, a flange is formed at the end of the guide sleeve, and the flange is fixedly connected to the outer mold through bolts. The lateral driving unit and the rotational driving unit are fixedly supported on the flange.

[0016] (III) Advantageous Effects

[0017] The present invention provides a low-temperature extrusion die for a cable insulating layer, which has the following advantageous effects: Under the action of the rotational driving unit, the intermediate pipe drives the spiral blade to rotate around the inner sleeve, thereby pushing the material and the insoluble substances in the material forward, reducing the accumulation at the front end of the inner sleeve. On the one hand, it reduces the influence on the fluidity of the material, and on the other hand, it reduces the frequency of stopping the machine to clean the die, improving the production quality. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the first perspective of the present invention;

[0019] Figure 2 is a sectional schematic diagram of the second perspective of the present invention;

[0020] Figure 3 is Figure 2 the enlarged partial structural diagram at A in

[0021] Figure 4 is Figure 2 the enlarged partial structural diagram at B in

[0022] Figure 5 is Figure 2 the enlarged partial structural diagram at C in

[0023] Figure 6 is a schematic structural diagram of the third perspective of the present invention;

[0024] Figure 7 is Figure 6 the sectional schematic diagram in the D-D direction of

[0025] Figure 8 is Figure 6 the sectional schematic diagram in the E-E direction of

[0026] In the figure:

[0027] 1. Outer mold;

[0028] 1a. Outer mold body;

[0029] 1b. Gate collar;

[0030] 2. Die core;

[0031] 3. Die sleeve;

[0032] 3a. Extrusion port;

[0033] 4. Inner pressure ring;

[0034] 5. Outer pressure ring;

[0035] 6. Outer sleeve;

[0036] 6a. Spline teeth;

[0037] 7. Inner sleeve;

[0038] 7a. First thin pipe section;

[0039] 7a-1. Front end;

[0040] 7b. First thick pipe section;

[0041] 8. Intermediate pipe;

[0042] 8a. Second thin pipe section;

[0043] 8b. Second thick pipe section;

[0044] 9. First bearing;

[0045] 10. Guide sleeve;

[0046] 11. Connecting collar;

[0047] 12. Second bearing;

[0048] 13. Second locking nut;

[0049] 14. Driven gear;

[0050] 15. Screw;

[0051] 16 Support frame;

[0052] 16a. Support sleeve;

[0053] 16b. Support plate;

[0054] 17. First locking nut;

[0055] 18. First locking bolt;

[0056] 19. Second locking bolt;

[0057] 20. Servo motor;

[0058] 21. Driving gear;

[0059] 22. Electric push rod;

[0060] 23. Helical blade. Detailed implementation method

[0061] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0062] Referring to the attached Figure 1-8 , a low-temperature extrusion die for a cable insulating layer, comprising an outer die 1, a die core 2 and a die sleeve 3. Similar to the existing extrusion die for a cable insulating layer, the outer die 1 includes an outer die body 1a and a gate collar 1b connected coaxially. The outer die 1 is provided with a perforation penetrating through both ends along the axial direction. The die core 2 is threadedly connected to the end of an outer sleeve 6. The outer sleeve 6 and the die core 2 are inserted into the perforation of the outer die. The tapered portion at the front end of the die core 2 extends out of the perforation. The die sleeve 3 is fixedly installed at the front end of the outer die by a retaining ring. A sizing cavity one is formed between the cylindrical main body portion of the die core 2 and the perforation, and a tapered cavity two is formed between the tapered portion at its front end and the die sleeve 3. The cavity one and the cavity two communicate with each other. Among them, the retaining ring includes an outer retaining ring 5 and an inner retaining ring 4. The front end of the inner retaining ring 4 and the front end of the die sleeve 3 are limited and matched through an inner convex stop and an inner concave stop. The rear end of the inner retaining ring 4 and the rear end of the outer retaining ring 5 are limited and matched through an outer convex stop and an outer concave stop. A group of long bolts distributed at intervals in a ring shape sequentially pass through the outer retaining ring 5 and the gate collar 1b and are then threadedly connected to the outer die body 1a to lock and fix the outer retaining ring 5, the gate collar 1b and the outer die body 1a. 3-4 first locking bolts 18 distributed in a ring shape penetrate through the outer retaining ring 5 in the radial direction to press the inner retaining ring 4 tightly.

[0063] In this embodiment, the die core 2 is driven by a transverse driving unit to translate axially along the die sleeve 3. An inner sleeve 7 and an intermediate tube 8 are coaxially inserted into the die core 2 from inside to outside. The front end portion 7a-1 of the inner sleeve 7 extends out of the die core 2 and is spaced from the extrusion port 3a of the die sleeve 3 to form a die nozzle structure of a semi-extrusion tube die. The intermediate tube 8 is driven by a rotation driving unit to rotate around the inner sleeve 7. A belt-shaped spiral blade 23 is fixedly connected to the front end of the intermediate tube 8. The spiral blade 23 is arranged around the front end portion 7a-1 of the inner sleeve 7. One end of the spiral blade 23 is received in the die core 2, and the other end extends out of the die core 2 and is spaced from the opening of the front end of the inner sleeve 7, and it is ensured that when the die core 2 is horizontally adjusted, the spiral blade 23 always maintains the above state. A chamfer is provided at the outer edge of the opening of the front end portion 7a-1 of the inner sleeve 7. By horizontally moving the die core 2, the gap of the cavity two can be adjusted, the fluctuation of the material flow rate can be controlled, the outlet shear speed can be stabilized, the surface roughness of the insulating layer can be improved, and the wrapping quality of the insulating layer can be enhanced.

[0064] Specifically, the inner sleeve 7 includes a first thin pipe section 7a and a first thick pipe section 7b that are coaxially connected. The inner sides of the pipe bodies of the first thin pipe section 7a and the first thick pipe section 7b are transitioned through a conical surface to facilitate the insertion of the wire core of the cable. The intermediate pipe 8 includes a second thin pipe section 8a and a second thick pipe section 8b that are coaxially arranged. The first thin pipe section 7a and the second thin pipe section 8a are coaxially inserted into the die core 2 from the inside out. The first thick pipe section 7b and the second thick pipe section 8b are coaxially inserted into the outer sleeve 6 from the inside out. The first thick pipe section 7b is fixedly connected to the outer die through a support frame. The second thick pipe section 8b is rotationally matched with the first thick pipe section 7b through a bearing and is driven by a rotational drive unit to rotate around the first thick pipe section 7b. The outer sleeve 6 is driven by a lateral drive unit to translate axially along the die sleeve 3.

[0065] Among them, the support frame includes a support sleeve 16a and a support plate 16b. The two ends of the support sleeve 16a are respectively fixed with a support plate 16b. The support sleeve 16a is sleeved outside the first thick pipe section 7b and is threadedly connected with a second locking bolt 19. The second locking bolt 19 tightly fixes the first thick pipe section 7b. A pair of screw rods 15 are connected to the outer die. The two ends of the support plate 16b are penetrated by the screw rods 15 and are clamped and fixed by a pair of first locking nuts 17.

[0066] Among them, a guide sleeve 10 is inserted between the outer sleeve 6 and the outer die. The guide sleeve 10 is slidably matched with the outer sleeve 6 through spline teeth 6a and spline grooves.

[0067] The lateral drive unit is an electric push rod 22. The output end of the electric push rod 22 is connected to the end of the outer sleeve 6 exposed outside the outer die through a connecting rod.

[0068] The rotational drive unit is specifically a servo motor 20. The output end of the servo motor 20 can be equipped with a speed reducer according to requirements. The output end of the speed reducer is connected to a driving gear 21. The end of the second thick pipe section 8b exposed outside the outer sleeve 6 is connected to a driven gear 14. The driven gear 14 meshes with the driving gear 21.

[0069] The electric push rod 22 and the servo motor 20 are relatively fixed to the outer die. The electric push rod 22 and the servo motor 20 can be fixedly supported on the outer die or can be additionally equipped with corresponding supports. For example, a flange is formed at the end of the guide sleeve 10. The flange is attached to the end face of the outer die and is locked and fixed by bolts. The lateral drive unit and the rotational drive unit can be fixedly supported on the flange.

[0070] Wherein, the end of the first thick pipe section 7b close to the first thin pipe section 7a is rotationally matched with the second thick pipe section 8b through a first bearing 9, and the other end of the first thick pipe section 7b is rotationally matched with an adapter ring 11 through a second bearing 12. The adapter ring 11 is coaxially and fixedly connected to the second thick pipe. The adapter ring 11 has a structure similar to that of the inner sleeve 7 and the intermediate pipe 8, including a third thin pipe section and a third thick pipe section connected coaxially. The third thin pipe section is fixedly connected to the second thick pipe section 8b, and the outer diameter of the third thick pipe section is larger than that of the second thick pipe section 8b to provide an installation space for the second bearing 12. In the figure, a second locking nut 13 is threadedly connected to the first thick pipe section 7b to press against the second bearing 12.

[0071] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or sequence between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-temperature extrusion die for cable insulation layer, comprising an outer die, a die core and a die sleeve. The die core is inserted into the outer die, the die sleeve is fixed at the front end of the outer die, and a cavity is formed between the outer die and the die core and the die sleeve. It is characterized in that: The core is driven by a lateral driving unit to translate axially along the die sleeve. An inner sleeve and an intermediate tube are coaxially inserted into the core from the inside out. The front end of the inner sleeve extends out of the core and is spaced from the extrusion port of the die sleeve. The intermediate tube is driven by a rotational driving unit to rotate around the inner sleeve. A spiral blade is provided at the front end of the intermediate tube. One end of the spiral blade is received in the core, and the other end extends out of the core and is spaced from the opening at the front end of the inner sleeve.

2. The low-temperature extrusion die for a cable insulating layer according to claim 1, characterized in that: The core is coaxially fixed to the end of an outer sleeve. The outer sleeve is coaxially supported in an outer die. The inner sleeve includes a first thin tube section and a first thick tube section connected coaxially. The intermediate tube includes a second thin tube section and a second thick tube section arranged coaxially. The first thin tube section and the second thin tube section are coaxially inserted into the core from the inside out. The first thick tube section and the second thick tube section are coaxially inserted into the outer sleeve from the inside out. The first thick tube section is fixedly connected to the outer die through a support frame. The second thick tube section is rotationally matched with the first thick tube section through a bearing and is driven by a rotational driving unit to rotate around the first thick tube section. The outer sleeve is driven by a lateral driving unit to translate axially along the die sleeve.

3. The low-temperature extrusion die for a cable insulating layer according to claim 2, characterized in that: The support frame includes a support sleeve and a support plate. Support plates are respectively fixed at both ends of the support sleeve. The support sleeve is sleeved outside the first thick tube section and is threadedly connected with a second locking bolt. The second locking bolt presses and fixes the first thick tube section. A pair of screw rods are connected to the outer die. Both ends of the support plate are penetrated by the screw rods and are clamped and fixed by a pair of first locking nuts.

4. The low-temperature extrusion die for a cable insulating layer according to claim 3, wherein: The end of the outer sleeve exposed outside the outer die is connected to a lateral driving unit, and the lateral driving unit is specifically an electric push rod.

5. The low-temperature extrusion die for a cable insulating layer according to claim 4, characterized in that: The end of the second thick tube section exposed outside the outer sleeve is connected to a driven gear, and the driven gear meshes with the driving gear at the output end of the rotational driving unit. The rotational driving unit is specifically a servo motor.

6. The low-temperature extrusion die for a cable insulating layer according to claim 5, characterized in that: The end of the first thick tube section close to the first thin tube section is rotationally matched with the second thick tube section through a first bearing. The other end of the first thick tube section is rotationally matched with an adapter ring through a second bearing. The adapter ring is coaxially fixed to the second thick tube.

7. The low-temperature extrusion die for a cable insulating layer according to claim 6, characterized in that: A guide sleeve is inserted between the outer sleeve and the outer die. The guide sleeve and the outer sleeve are slidably matched through splines and spline grooves.

8. The low-temperature extrusion die for a cable insulating layer according to claim 7, characterized in that: A flange is formed at the end of the guide sleeve. The flange is fixedly connected to the outer die through bolts. The lateral driving unit and the rotational driving unit are fixedly supported on the flange.

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