CN112873801A - Extrusion molding die for cable sheath forming - Google Patents

Abstract

The invention relates to an extrusion molding die for cable sheath forming, which comprises a die sleeve and a die core. A first installation cavity is arranged in the die sleeve. The central axis of the first installation cavity is coincident with the central axis of the die sleeve. The mold core is arranged in the first mounting cavity in a penetrating mode and is connected through the first thread pair. The first thread pair is composed of a first internal thread and a first external thread which are mutually matched, wherein the first internal thread is arranged on the inner side wall of the first mounting cavity and formed by extending the left end of the first internal thread rightwards; the first external thread is arranged around the outer side wall of the mold core. Therefore, on one hand, the good concentricity between the die sleeve and the die core is ensured, and the wall thickness consistency of the sheath on the periphery of the formed cable is ensured; on the other hand, before the sheath forming process is executed, the die sleeve and the die core are connected into a whole in advance, so that the requirement of on-line concentricity adjustment is eliminated, the safety of workers is ensured, and the PE material is prevented from being blocked.

Description

Extrusion molding die for cable sheath forming

Technical Field

The invention relates to the technical field of cable manufacturing, in particular to an extrusion molding die for cable sheath molding.

Background

Generally, a jacket must be wrapped around the periphery of the cable to provide better protection to the optical fibers. The jacket must have excellent mechanical, environmental and chemical resistance to withstand the effects of the various particular and complex external environments.

In the process of manufacturing and forming the optical cable, the sheath needs to be formed by an extrusion molding die. As shown in fig. 1, in the prior art, an extrusion die is composed of a die case and a core which are separated from each other. In the formal execution process of the sheath forming procedure, operators need to manually adjust the concentricity between the die sleeve and the die core so as to ensure the uniformity of the wall thickness of the sheath after the optical cable is extruded. However, in the actual production process, the operating skills and psychological states of operators are different, and the concentricity adjustment is not easy to retest, so that the phenomenon of over-tolerance of concentricity is easily caused, and the wall thickness of the optical cable is not uniform. The optical cable is easy to crack in the subsequent actual use process, and the service life of the optical cable is seriously reduced; in addition, there is a certain operational risk in adjusting the concentricity between the die sleeve and the die core on line, and the PE material in a partial area is easily blocked, thereby affecting the continuity of the sheath molding, and thus, a skilled person is urgently needed to solve the above problems.

Disclosure of Invention

Therefore, in view of the above-mentioned problems and drawbacks, the present inventor has collected relevant information, evaluated and considered in many ways, and made continuous experiments and modifications by technicians engaged in the industry through years of research and development experience, which finally resulted in the appearance of the extrusion mold for cable sheath formation.

In order to solve the technical problem, the invention relates to an extrusion molding die for cable sheath forming, which comprises a die sleeve and a die core. A first installation cavity is arranged in the die sleeve. The central axis of the first installation cavity is coincident with the central axis of the die sleeve. The mold core is arranged in the first mounting cavity in a penetrating mode and is connected through the first thread pair. The first thread pair is composed of a first internal thread and a first external thread which are mutually matched, wherein the first internal thread is arranged on the inner side wall of the first mounting cavity and formed by extending the left end of the first internal thread rightwards; the first external thread is arranged around the outer side wall of the mold core.

As a further improvement of the technical scheme of the invention, the first thread pair is preferably a fine triangular thread pair.

As a further improvement of the technical scheme of the invention, the extrusion molding die for forming the cable sheath also comprises a first anti-loosening gasket. The first anti-loosening gasket is arranged in the first installation cavity and is elastically pressed between the die sleeve and the die core.

As a further improvement of the technical scheme of the invention, the mould core is provided with a PE runner hole. The PE runner holes are arranged in a plurality of numbers, are uniformly distributed around the central axis of the mold core and are communicated with the first installation cavity all the time.

As a further improvement of the technical scheme of the invention, the mold core comprises a first mold core part and a second mold core part. And a second installation cavity is arranged in the first mold core component. The central axis of the second installation cavity is coincident with the central axis of the first mold core component. The second mold core parts penetrate through the second installation cavity and are connected by means of the second thread pair. The PE runner hole is formed in the first mold core part. The second thread pair is composed of a second internal thread and a second external thread which are mutually matched, wherein the second internal thread is arranged on the inner side wall of the second mounting cavity and formed by extending the left end of the second internal thread rightwards; the second external threads are formed around the outer side wall of the second mold core component.

As a further improvement of the technical scheme of the invention, the second thread pair is preferably a fine triangular thread pair.

As a further improvement of the technical scheme of the invention, the mold core also comprises a second anti-loosening gasket. The second anti-loosening gasket is arranged in the second installation cavity and is elastically pressed between the first mold core component and the second mold core component.

Compared with the extrusion molding die for cable sheath molding with the traditional design structure, in the technical scheme disclosed by the invention, the die sleeve and the die core are sleeved with each other and are detachably connected by virtue of the thread pair. Therefore, on one hand, the good concentricity between the die sleeve and the die core is ensured, and the wall thickness consistency of the sheath on the periphery of the formed cable is ensured; on the other hand, before the sheath forming process is executed, the die sleeve and the die core are connected into a whole in advance, so that the requirement of on-line concentricity adjustment is eliminated, the safety of workers is ensured, and the PE material is prevented from being blocked.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is an exploded view of a prior art extrusion die for cable jacket formation.

Fig. 2 is an exploded view of a first embodiment of the extrusion die for cable jacket formation of the present invention.

Fig. 3 is an exploded view of a second embodiment of the extrusion die for cable jacket formation of the present invention.

1-die sleeve; 11-a first mounting cavity; 111-a first internal thread; 2, a mold core; 21-a first core part; 211 — a first external thread; 212-a second mounting cavity; 2121-a second internal thread; 213-PE flow channel holes; 22-a second core part; 221-second external thread; 23-a second anti-loose gasket; 3-first anti-loose gasket.

Detailed Description

In the description of the present invention, it is to be understood that the terms "left", "right", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

The present invention will be described in further detail with reference to the following specific examples, and fig. 2 shows an exploded view of a first embodiment of an extrusion mold for cable sheath molding according to the present invention, which is mainly composed of a mold sleeve 1, a mold core 2, and the like. Wherein, a first installation cavity 11 is arranged in the die sleeve 1 for penetrating the die core 2. In order to ensure the reliability of the connection between the core 2 and the die case 1 and to ensure a good concentricity therebetween, the central axis of the first mounting cavity 11 and the central axis of the die case 1 are completely coincident, and the core 2 and the die case 1 are coupled by means of a first thread pair. The specific proposal is recommended as follows: a first internal thread 111 forming a first thread pair is arranged on the inner side wall of the first mounting cavity 11 and formed by extending the left end of the first internal thread rightwards; a first external thread 211 adapted to the first internal thread 111 is provided around the outer side wall of the mold core 2. Therefore, on one hand, the good concentricity between the die sleeve 1 and the die core 2 is ensured, and the wall thickness consistency of the sheath on the periphery of the formed cable is ensured; on the other hand, before the sheath forming procedure is executed, the die sleeve 1 and the die core 2 are connected into a whole in advance, so that the requirement of on-line concentricity adjustment is eliminated, and the safety of workers is ensured; on the other hand, the smoothness of the PE material flow channel is ensured, and the phenomenon that the PE material is blocked is further avoided.

As a further optimization of the structure of the extrusion mold for cable sheath molding, the first internal thread 111 and the first external thread 211 are preferably fine triangular threads. The fine triangular thread has the following characteristics: 1) the helix angle is smaller, and the number of the screwed-in teeth is larger on the same thread length, so that the self-locking of the thread is facilitated, and the phenomenon that the mold core 2 is loosened relative to the mold sleeve 1 in the actual extrusion molding process is prevented; 2) the smaller pitch is advantageous for ensuring concentricity between the die sleeve 1 and the die core 2 by fine adjustment.

In the conventional design, the mold core 2 is sleeved in the mold sleeve 1, and an annular gap is formed between the mold core and the mold sleeve for PE material to flow through. However, in the actual forming process, the flow rate of the PE material flowing in the annular space is extremely unstable and difficult to control, thereby affecting the surface smoothness of the formed sheath. In view of this, as a preferable design, a PE runner hole 213 may be further formed on the mold core 2. The number of the PE runner holes 213 is set to be plural, and the PE runner holes are uniformly distributed around the central axis of the mold core 2 and are always communicated with the first mounting cavity 11 (as shown in fig. 2). The PE flow channel hole 213 can effectively divide the PE material, and subsequently, the size and the relative position of the PE flow channel hole 213 are changed to ensure the stability and consistency of the flow speed of the PE material, and the balance of the internal pressure of the PE material is ensured.

In the actual forming process of the sheath, the mold core 2 is a wearing part, and needs to be replaced when the abrasion amount is out of tolerance so as to ensure the forming quality of the sheath. However, the cost required to replace the core 2 as a whole is high. In view of this, as can also be seen from fig. 2, the mold core 2 may also be designed as a split structure, as follows: the mold core 2 is formed essentially from a first mold core part 21, a second mold core part 22 and the like. A second mounting space 212 is provided in the first core part 21. The central axis of the second mounting cavity 212 coincides with the central axis of the first core segment 21. The second core part 22 is inserted into the second mounting cavity 212 and is coupled by means of a second thread pair. The PE flow passage hole 213 is opened in the first core segment 21. A second internal thread 2121 constituting a second thread pair is formed by extending rightward from the left end of the second internal thread on the inner side wall of the second mounting cavity 212; the second external thread 221 opens around the outer side wall of the second core part 22. After the first mold core component 21 and the second mold core component 22 are respectively and independently processed and molded, the first mold core component and the second mold core component are detachably connected into a whole in a screwing mode. In this way, when the core 2 is worn or damaged and normal use is affected, the first core part 21 or the second core part 22 can be replaced independently, so that the later maintenance cost of the extrusion mold is greatly reduced.

Of course, similar to the design of the first external thread 211 and the first internal thread 111, the second internal thread 2121 and the second external thread 221 may also be both preferably fine triangular threads.

Fig. 3 shows an exploded view of a second embodiment of the extrusion die for cable sheath formation according to the invention, which differs from the first embodiment described above in that: 1) a first locking gasket 3 is additionally arranged in the extrusion molding die for cable sheath forming. The first anti-loosening gasket 3 is arranged in the first mounting cavity 11 and is elastically pressed between the die sleeve 1 and the die core 2, so that the phenomenon that the die core 2 is loosened relative to the die sleeve 1 is effectively avoided, and the concentricity of the die core and the die sleeve is further ensured; 2) a second anti-loosening gasket 23 is additionally arranged in the split-type mold core 2. The second anti-loosening gasket 23 is arranged in the second mounting cavity 212 and is elastically pressed between the first mold core part 21 and the second mold core part 22, so that the phenomenon that the second mold core part 22 is loosened relative to the first mold core part 21 is effectively avoided, and the integral concentricity of the extrusion molding mold is further ensured.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. An extrusion molding die for cable sheath molding is characterized by comprising a die sleeve and a die core; a first mounting cavity is arranged in the die sleeve; the central axis of the first mounting cavity is coincident with the central axis of the die sleeve; the mold core is arranged in the first mounting cavity in a penetrating mode and is connected by means of a first thread pair; the first thread pair is composed of a first internal thread and a first external thread which are mutually matched, wherein the first internal thread is arranged on the inner side wall of the first mounting cavity and formed by extending the left end of the first internal thread rightwards; the first external thread is arranged around the outer side wall of the mold core.

2. The extrusion die for cable sheathing formation according to claim 1, wherein the first thread pair is a fine triangular thread pair.

3. The extrusion die for cable sheath molding of claim 1, further comprising a first anti-loosening spacer; the first anti-loosening gasket is arranged in the first installation cavity and is elastically pressed between the die sleeve and the die core.

4. The extrusion molding die for cable sheath molding according to any one of claims 1 to 3, wherein a PE flow passage hole is opened on the core; the PE runner hole's quantity sets up to a plurality ofly, centers on the central axis of mold core carries out the equipartition, and communicate with all the time first installation cavity mutually.

5. The extrusion die for cable jacket molding of claim 4, wherein said core comprises a first core segment and a second core segment; a second installation cavity is formed in the first mold core component; the central axis of the second mounting cavity is coincident with the central axis of the first mold core component; the second mold core parts are arranged in the second mounting cavity in a penetrating mode and are connected through a second thread pair; the PE runner hole is formed in the first mold core part; the second thread pair is composed of a second internal thread and a second external thread which are mutually matched, wherein the second internal thread is arranged on the inner side wall of the second mounting cavity and formed by extending the left end of the second internal thread rightwards; the second external threads are formed around the outer side wall of the second mold core component.

6. An extrusion die for cable sheathing according to claim 5, wherein said second thread pair is a fine triangular thread pair.

7. The extrusion die for cable sheath molding of claim 6, wherein the mold core further comprises a second anti-loose spacer; the second anti-loosening gasket is arranged in the second installation cavity and is elastically pressed between the first mold core component and the second mold core component.

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