Low-capacitance coaxial line with a lotus root structure and an extrusion molding device thereof

Abstract

The present application relates to the technical fields of low-capacitance coaxial line, in particular to a lotus root structure low-capacitance coaxial line and its extrusion forming device, which comprises a wire and a lotus root core shielding layer covering the wire; the lotus root core shielding layer comprises an inner shielding layer and an outer shielding layer, the outer wall of the inner shielding layer and the inner wall of the outer shielding layer are connected through a discontinuously arranged connecting part, and the cross section of the connecting part is arranged in a non-linear shape; when the coaxial line is pressed or bent, adaptive deformation can be generated, the bending resistance is reduced, the lotus root core shielding layer is more easily bent synchronously with the wire, the rigid connection of the whole shielding layer is broken, the overall rigidity of the cable is further reduced, and the flexibility is improved.

Description

Technical Field

[0001] This invention relates to the field of low-capacitance coaxial cable technology, and more specifically to a lotus root-shaped low-capacitance coaxial cable and its extrusion molding apparatus. Background Technology

[0002] In the structural design of coaxial cables, the shielding layer is a key component determining the electromagnetic shielding effect. The core-shaped shielding layer, due to its advantages of lightweight and low capacitance, is gradually becoming the preferred solution for demanding applications. Currently, mass production of core-shaped shielding layers has been achieved through a specific mold core structure. This mold can form an inner shielding layer, an outer shielding layer, and a continuous connecting part between the two, forming an integral core structure, which has certain advantages in terms of shielding performance and production efficiency.

[0003] However, significant drawbacks exist in practical applications: in its formed core-shaped shielding layer, the connection between the inner and outer shielding layers is a continuous structure, and the rigidity of the connection is consistent with that of the inner and outer shielding layers. This structure results in excessive overall rigidity of the coaxial cable and poor bending performance. When the coaxial cable needs to adapt to curved wiring scenarios, not only is the operation difficult, but the concentrated bending stress can also cause the shielding layer to crack and the connection to break, thereby compromising the integrity of electromagnetic shielding and causing problems such as signal transmission attenuation and reduced anti-interference capability. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a lotus root-shaped low-capacitance coaxial cable and its extrusion molding device.

[0005] To achieve the above objectives, the specific solution of the present invention is as follows:

[0006] The present invention provides a low-capacitance coaxial cable with a lotus root structure, including a conductor and a core shielding layer covering the outside of the conductor; the core shielding layer includes an inner shielding layer and an outer shielding layer, the outer wall of the inner shielding layer and the inner wall of the outer shielding layer are connected by a discontinuous connecting part, and the cross-section of the connecting part is non-linear.

[0007] Furthermore, the present invention provides multiple sets of connecting portions between the inner shielding layer and the outer shielding layer along the axis of the conductor, and each set of connecting portions consists of multiple connecting portions evenly distributed around the axis of the conductor in the circumferential direction.

[0008] Furthermore, the cross-sectional shape of the connecting portion is S-shaped.

[0009] Furthermore, the thickness of the connecting portion is less than the thickness of the outer shielding portion and the thickness of the inner shielding portion.

[0010] The present invention also provides an extrusion molding apparatus for manufacturing the above-described lotus root-shaped low-capacitance coaxial line, comprising an extrusion seat; the extrusion end of the extrusion seat is provided with a first die core, a second die core and a third die core arranged coaxially;

[0011] The first die core has a plurality of extrusion molding parts extending axially and distributed around the axis at one end facing away from the extrusion seat; a connecting channel is formed between two adjacent extrusion molding parts, the cross-sectional shape of which is adapted to the cross-sectional shape of the connecting part;

[0012] The second mold core is located at the end of the first mold core facing away from the extrusion seat; the end of the second mold core facing away from the first mold core is provided with an extrusion sleeve portion; the extrusion sleeve portion is sleeved on the outside of the extrusion molding portion; an outer molding cavity is formed between the inner wall of the extrusion sleeve portion and the outer wall of the extrusion molding portion; an inner molding cavity is formed between the inner wall of the extrusion molding portion and the outer wall of the wire; the connecting channel connects the outer molding cavity and the inner molding cavity;

[0013] One end of the third die core is movably disposed in the shaft hole of the extrusion seat, and the other end extends movably into the shaft hole of the first die core; the end face of the other end of the third die core is provided with a plurality of isolation parts extending axially and distributed around the axis; the cross-sectional shape of the isolation parts is adapted to the cross-sectional shape of the connecting channel; the isolation parts are inserted into the connecting channel one by one, thereby controlling the effective length of the connecting channel in the axial direction.

[0014] Furthermore, the first mold core is provided with at least one first channel; the first mold core is also provided with at least one second channel; one end of the at least one second channel is connected to the first channel, and the other end is connected to the outer molding cavity and the inner molding cavity; corresponding to each first channel in the first mold core, a valve core is provided at the end of the first channel near the second channel, which is perpendicular to the first channel and is used to control the opening and closing of the first channel and the second channel; the first mold core is also provided with at least one third channel connected to the end of the first channel away from the second channel;

[0015] The third mold core is provided with a fourth channel corresponding to each isolation part; the fourth channel penetrates the isolation part along the length direction of the corresponding isolation part; the outer wall of the third mold core is also provided with an annular groove that communicates with each fourth channel; when the third mold core moves to the position where the annular groove corresponds to the third channel, the annular groove communicates with the first channel through the third channel.

[0016] Furthermore, in this invention, the number of the first channel, the number of the second channel, and the number of the third channel all correspond one-to-one with the number of the fourth channel.

[0017] Furthermore, a return spring is connected between the valve core and the first mold core; the valve core has a through hole extending through it radially; under the elastic force of the return spring, the valve core extends into the shaft hole of the first mold core, so that the through hole on the valve core is misaligned with the first channel.

[0018] Furthermore, the cross-sectional shape of the extrusion molding part, the connecting channel, and the isolation part are all S-shaped.

[0019] Furthermore, the third mold core has a pin protruding from one end of its outer wall; the extrusion seat has a clearance strip hole for the pin to pass through the extrusion seat.

[0020] The extrusion seat is also provided with a drive mechanism for driving the third die core to reciprocate axial linear motion via a pin.

[0021] The beneficial effects of the present invention are as follows: The low capacitance coaxial cable with a lotus root structure of the present invention sets the connection part between the inner shielding layer and the outer shielding layer to be non-linear. This structure can produce adaptive deformation when the coaxial cable is compressed or bent, reducing bending resistance and making it easier for the core shielding layer to bend synchronously with the conductor. Furthermore, the connection parts are distributed at intervals along the conductor axis, breaking the rigid connection of the shielding layer as a whole, further reducing the overall rigidity of the cable and improving its flexibility.

[0022] Figure 1 This is a cross-sectional schematic diagram of the low-capacitance coaxial line with a lotus root structure provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the extrusion molding apparatus provided in an embodiment of the present invention;

[0024] Figure 3 This is a cross-sectional schematic diagram of the extrusion molding apparatus provided in this embodiment of the invention when the third die core is moved to the rear stop position;

[0025] Figure 4 This is a cross-sectional schematic diagram of the extrusion molding apparatus provided in this embodiment of the invention when the third die core moves forward to the front stop position;

[0026] Figure 5 This is a cross-sectional schematic diagram of the first mold core, the second mold core, and the third mold core provided in an embodiment of the present invention.

[0027] Figure 6 This is a cross-sectional schematic diagram of the first mold core and valve core mating according to an embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram of the structure of the first mold core provided in an embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the structure of the third mold core provided in an embodiment of the present invention;

[0030] Figure 9 This is a cross-sectional schematic diagram of the cooperation between the drive mechanism and the adjustment mechanism provided in an embodiment of the present invention;

[0031] Explanation of reference numerals in the attached drawings: 1. Wire; 2. Coupling core shielding layer; 21. Inner shielding layer; 22. Outer shielding layer; 23. Connecting part; 10. Extrusion seat; 20. First die core; 201. Extrusion molding part; 202. Connecting channel; 203. First channel; 204. Second channel; 205. Third channel; 30. Second die core; 301. Extrusion sleeve part; 40. Third die core; 401. Isolation part; 402. Fourth channel; 403, Annular groove; 404, Pin; 50, Outer forming cavity; 60, Inner forming cavity; 70, Valve core; 701, Return spring; 702, Through hole; 801, Drive seat; 802, Motor; 803, Drive slider; 8031, Drive bar hole; 804, Eccentric wheel; 901, Adjusting seat; 902, Adjusting slide; 903, First slider; 904, Second slider; 905, Tension spring; 906, Bolt. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this is not to limit the scope of the invention to this.

[0033] like Figures 1 to 9 As shown, the low-capacitance coaxial cable with a lotus root structure described in this embodiment includes a conductor 1 and a core shielding layer 2 covering the outside of the conductor 1. The core shielding layer 2 includes an inner shielding layer 21 and an outer shielding layer 22. The outer wall of the inner shielding layer 21 and the inner wall of the outer shielding layer 22 are connected by a discontinuously arranged connecting portion 23, and the cross-section of the connecting portion 23 is non-linear. Preferably, as shown... Figure 1 As shown, the cross-sectional shape of the connecting part 23 is S-shaped. Compared with other non-linear shapes such as arc and broken line, the S-shaped cross-section has better deformation margin. When bending, the crest and trough of the S-shape can generate tensile and compressive deformation respectively, avoiding the connection part 23 from breaking due to stress concentration, and reducing the pulling on the inner shielding layer 21 and the outer shielding layer 22.

[0034] Specifically, the low-capacitance coaxial cable with a lotus root structure in this embodiment sets the connection portion 23 between the inner shielding layer 21 and the outer shielding layer 22 to be non-linear. This structure can produce adaptive deformation when the coaxial cable is compressed or bent, reducing bending resistance and making it easier for the core shielding layer 2 to bend synchronously with the conductor 1. Furthermore, the connection portion 23 is distributed at intervals along the axial direction of the conductor 1, breaking the rigid connection of the shielding layer as a whole, further reducing the overall rigidity of the cable and improving its flexibility.

[0035] like Figure 1As shown, in this embodiment, the low-capacitance coaxial cable with a lotus-shaped structure has multiple sets of connecting portions 23 arranged between the inner shielding layer 21 and the outer shielding layer 22 along the axis of the conductor 1. Each set of connecting portions 23 consists of multiple connecting portions 23 evenly distributed around the axis of the conductor 1 in the circumferential direction. For example, each set has six connecting portions 23, distributed at 60° intervals along the circumference. Through the above arrangement, this embodiment ensures the structural stability and uniformity of the lotus core shielding layer 2.

[0036] In this embodiment, the low-capacitance coaxial cable with a lotus root structure has a connecting portion 23 with a thickness less than that of the outer shielding portion and the inner shielding portion. This embodiment further optimizes bending performance through the above-mentioned design. This design makes the connecting portion 23 a "flexible weak area" in the core shielding layer 2, preferentially deforming during bending. This avoids rigid resistance from the inner shielding layer 21 and the outer shielding layer 22 due to their larger thickness, while ensuring that the shielding performance of the inner shielding layer 21 and the outer shielding layer 22 is not affected.

[0037] like Figures 2 to 9 As shown, this embodiment of the invention also provides an extrusion molding device for manufacturing the above-mentioned lotus root structure low capacitance coaxial line, which achieves integrated molding of the lotus root shielding layer 2 through the coordinated cooperation of multiple die cores, specifically including an extrusion seat 10; the extrusion end of the extrusion seat 10 is provided with a first die core 20, a second die core 30 and a third die core 40 arranged coaxially.

[0038] The first mold core 20 has multiple axially extending and distributed extrusion molding portions 201 at one end facing away from the extrusion seat 10; a connecting channel 202 is formed between two adjacent extrusion molding portions 201, the cross-sectional shape of which is adapted to the cross-sectional shape of the connecting portion 23; the second mold core 30 is located at one end of the first mold core 20 facing away from the extrusion seat 10; the second mold core 30 has an extrusion sleeve portion 301 at one end facing away from the first mold core 20; the extrusion sleeve portion 301 is sleeved on the outside of the extrusion molding portion 201; an outer molding cavity 50 is formed between the inner wall of the extrusion sleeve portion 301 and the outer wall of the extrusion molding portion 201; an inner molding cavity 60 is formed between the inner wall of the extrusion molding portion 201 and the outer wall of the wire 1; the connecting channel 202 connects the outer molding cavity 50 and the inner molding cavity 60; one end of the third mold core 40 is movably provided with The third mold core 40 has a shaft hole in the extrusion seat 10 and a shaft hole in the first mold core 20. The other end of the third mold core 40 has a plurality of axially extending and distributed isolation parts 401 on its end face. The cross-sectional shape of the isolation parts 401 is adapted to the cross-sectional shape of the connecting channel 202. The isolation parts 401 are inserted into the connecting channel 202 one by one to control the effective length of the connecting channel 202 in the axial direction. When the isolation parts 401 are inserted into the connecting channel 202, they can block the flow of shielding material between the inner forming cavity 60 and the outer forming cavity 50, thereby stopping the forming of the connecting part 23. When the isolation parts 401 are partially pulled out, the length of the exposed connecting channel 202 is the forming length of the connecting part 23. The spacing and length of the connecting part 23 can be precisely controlled by adjusting the insertion depth.

[0039] Specifically, in actual use, the extrusion molding apparatus of this embodiment, such as Figure 3 and Figure 4 As shown, the lead wire 1 is sequentially passed through the extruder 10, the third die core 40, the first die core 20, and the second die core 30 along the axis of the extruder 10. The front end of the lead wire 1 can be pulled by a winding and traction device. When the third die core 40 drives each isolation part 401 to move forward to the front stop position, as shown... Figure 4 As shown, at this time, each isolation part 401 fills the connection channel 202, and the isolation part 401 blocks the corresponding connection channel 202, so that the shielding material entering the outer molding cavity 50 and the inner molding cavity 60 cannot communicate with each other through the connection channel 202. At this time, the shielding material entering the outer molding cavity 50 is formed into the outer shielding layer 22, and the shielding material entering the inner molding cavity 60 is formed into the inner shielding layer 21. Since the connection channel 202 is blocked by the isolation part 401, there is no connection part 23 between the outer shielding layer 22 and the inner shielding layer 21.

[0040] When the third mold core 40 drives each isolation part 401 to move to the rear stop position, such as Figure 3As shown, at this time, the blocking of the connection channel 202 is released in each isolation part 401. At this time, shielding material is injected into the connection channel 202, thereby forming the connection part 23 in the connection channel 202, and fixing the formed outer shielding layer 22 and inner shielding layer 21 together. Thus, through the reciprocating motion of the third mold core 40, a non-continuous connection part 23 with a non-linear cross section is formed between the inner shielding layer 21 and the outer shielding layer 22.

[0041] In this embodiment, an outer forming cavity 50 is formed between multiple extrusion molding sections 201 and the second die core 30, an inner forming cavity 60 is formed between the extrusion molding section 201 and the outer wall of the conductor 1, and a connecting channel 202 is formed between two adjacent extrusion molding sections 201. The opening and closing of the connecting channel 202 is controlled by the isolation section 401 on the third die core 40, thereby forming a connecting section 23 between the formed outer shielding layer 22 and the inner shielding layer 21. This achieves the integral molding of the lotus-shaped low-capacitance coaxial cable. The fabricated lotus-shaped low-capacitance coaxial cable can undergo adaptive deformation under pressure or bending, reducing bending resistance and making it easier for the core shielding layer 2 to bend synchronously with the conductor 1, breaking the rigid connection of the shielding layer as a whole, further reducing the overall rigidity of the cable and improving flexibility. Thus, by controlling the opening and closing length of the connecting channel 202, the molding length and spacing of the connecting section 23 can be controlled to meet different molding process requirements.

[0042] like Figures 6 to 8As shown, in this embodiment of the extrusion molding apparatus, the first die core 20 is provided with at least one first channel 203; the first die core 20 is also provided with at least one second channel 204; one end of the at least one second channel 204 is connected to the first channel 203, and the other end is connected to the outer molding cavity 50 and the inner molding cavity 60, for distributing the material conveyed by the first channel 203 into the outer molding cavity 50 and the inner molding cavity 60; corresponding to each first channel 203, the first die core 20 has a vertically penetrating first channel 203 at one end of the first channel 203 near the second channel 204, which is used to control the connection between the first channel 203 and the second channel. The valve core 70 is open and closed; the first mold core 20 is also provided with at least one third channel 205 that is connected to the end of the first channel 203 away from the second channel 204; the third mold core 40 is provided with a fourth channel 402 corresponding to each isolation part 401; the fourth channel 402 passes through the isolation part 401 along the length direction of the corresponding isolation part 401; the outer wall of the third mold core 40 is also provided with an annular groove 403 that is connected to each of the fourth channels 402; when the third mold core 40 moves to the position where the annular groove 403 corresponds to the third channel 205, the annular groove 403 is connected to the first channel 203 through the third channel 205. In this embodiment of the extrusion molding apparatus, the number of first channels 203, second channels 204, and third channels 205 are all one-to-one with the number of fourth channels 402. For example, for the third mold core 40 corresponding to the six isolation sections 401, six fourth channels 402 need to be set. At the same time, the first mold core 20 needs to be equipped with six first channels 203, six second channels 204, and six third channels 205 to ensure that the connecting channel 202 corresponding to each isolation section 401 can independently achieve material delivery and pressure balance, thereby improving molding stability.

[0043] Specifically, the first channel 203 serves as the main feeding channel, and its inner diameter can be designed according to the material conveying volume; the second channel 204 adopts a branch design, with each second channel 204 connecting the corresponding areas of the outer forming cavity 50 and the inner forming cavity 60 respectively, ensuring uniform material distribution; the valve core 70 adopts a cylindrical structure with a diameter that matches the inner diameter of the first channel 203, and achieves on / off control through vertical movement to avoid material leakage or poor flow.

[0044] It should be noted that the width of the annular groove 403 needs to cover the opening range of the third channel 205 to ensure stable connection during movement; when the annular groove 403 is aligned with the third channel 205, the material of the first channel 203 can enter the fourth channel 402 through the third channel 205 and the annular groove 403, and finally flow out from the end of the isolation part 401, thereby forming the connecting part 23 in the connecting channel 202.

[0045] Specifically, the extruder 10 is provided with a feeding channel (not shown in the figure) communicating with each of the first channels 203, through which shielding material is fed into each of the first channels 203. Initially, the valve core 70 closes the first channel 203, preventing the shielding material in the first channel 203 from entering the second channel 204; when the third mold core 40 moves forward to the front stop position, the valve core 70 opens the second channel 204, and the third channel 205 is offset from the annular groove 403 and blocked by the outer wall of the third mold core 40, so that the shielding material in the first channel 203 enters the outer forming cavity 50 and the inner forming cavity 60 through the second channel 204 respectively, to form the outer shielding layer 22 and the inner shielding layer 21; when the third mold core 40 moves backward to the rear stop position, the shielding material in the first channel 203 enters the outer forming cavity 50 and the inner forming cavity 60 respectively through the second channel 204, to form the outer shielding layer 22 and the inner shielding layer 21. At the stop position, the valve core 70 closes the first channel 203. At this time, the annular groove 403 corresponds to the position of the third channel 205, and the first channel 203 is connected to the fourth channel 402. At this time, the shielding material in the first channel 203 enters the annular groove 403 through the third channel 205, enters each of the fourth channels 402 through the annular groove 403, and then flows out from the end of the isolation part 401 to the connecting channel 202, thereby forming the connecting part 23 in the connecting channel 202. This operation is repeated to continuously produce the lotus root structure low capacitance coaxial cable.

[0046] like Figure 6 As shown, in the extrusion molding apparatus of this embodiment, a return spring 701 is connected between the valve core 70 and the first die core 20; the valve core 70 is provided with a through hole 702 extending through it radially. Preferably, the diameter of the through hole 702 is the same as the diameter of the first channel, so that the shielding material can pass through the through hole 702 and pass through the valve core 70; under the elastic force of the return spring 701, the valve core 70 extends into the shaft hole of the first die core 20, so that the through hole 702 on the valve core 70 is misaligned with the first channel 203, thereby preventing the shielding material in the first channel 203 from entering the second channel 204 through the first channel 203. In this embodiment, through the above-described configuration, the return spring 701 initially causes the through hole 702 on the valve core 70 to be misaligned with the first channel 203, thereby closing the first channel 203 and preventing the shielding material in the first channel 203 from entering the second channel 204. When the third mold core 40 moves forward to the front stop position, the outer wall of the third mold core 40 presses against the valve core 70, and the return spring 701 is compressed, causing the through hole 702 of the valve core 70 to align with the position of the first channel 203. At this time, the valve core 70 opens the first channel 203, allowing the shielding material in the first channel 203 to enter the second channel 204, thereby forming the outer shielding layer 22 and the inner shielding layer 21.

[0047] like Figures 5 to 8As shown, in this embodiment, the extrusion molding apparatus has an S-shaped cross-section for the extrusion molding section 201, the connecting channel 202, and the isolation section 401. Through this configuration, an S-shaped connecting section 23 is formed within the connecting channel 202. Compared to other non-linear shapes such as arcs and polygonal lines, the S-shaped cross-section has a better deformation allowance. During bending, the crests and troughs of the S-shape can generate tensile and compressive deformations respectively, preventing the connecting section 23 from breaking due to stress concentration, and reducing the pulling on the inner shielding layer 21 and the outer shielding layer 22.

[0048] like Figures 2 to 5 ,as well as Figure 8 and Figure 9 As shown, in this embodiment of the extrusion molding apparatus, a pin 404 protrudes from the outer wall of one end of the third die core 40; the extrusion seat 10 has a clearance strip hole for the pin 404 to pass through; the extrusion seat 10 also has a drive mechanism for driving the third die core 40 to reciprocate axial linear motion via the pin 404. Preferably, the pin 404 has a cylindrical structure, the diameter of which is adapted to the width of the clearance strip hole, and the length of the clearance strip hole must be greater than or equal to the maximum travel of the third die core 40 to provide sufficient travel space for the pin 404 and ensure that the third die core 40 can achieve full-stroke reciprocating motion. Figure 3 , Figure 4 as well as Figure 9 As shown, in this embodiment of the extrusion molding apparatus, specifically, the driving mechanism includes a driving slider 803; one end of the driving slider 803 is provided with a driving strip hole 8031; a pin 404 passes through the driving strip hole 8031; by cooperating with the driving strip hole 8031, the dwell time of the third mold core 40 at the front stop and rear stop positions is increased, so that sufficient shielding material can be injected into the outer molding cavity 50, the inner molding cavity 60, and the connecting channel 202 for molding. When the driving slider 803 reciprocates, the driving strip hole 8031 ​​drives the pin 404 to move synchronously, thereby realizing the axial movement of the third mold core 40. Figure 9 As shown, in this embodiment of the extrusion molding apparatus, the driving mechanism further includes a driving base 801 installed on the extrusion base 10 and a motor 802 located on the top of the driving base 801; the driving slider 803 is slidably connected to the bottom of the driving base 801; the other end of the driving slider 803 is provided with a driving groove; the driving groove is provided with an eccentric wheel 804 connected to the output end of the motor 802; the motor 802 drives the eccentric wheel 804 to rotate, so that the eccentric wheel 804 drives the driving slider 803 to reciprocate.

[0049] For example, the motor 802 can be a stepper motor 802 or a servo motor 802, which can precisely control the speed and thus adjust the rotation frequency of the eccentric wheel 804, thereby adjusting the reciprocating speed of the driven slider 803. It should be noted that the eccentricity of the eccentric wheel 804 determines the travel of the driven slider 803. Different eccentricity eccentric wheels 804 can be replaced according to the interval requirements of the connecting part 23 to improve the versatility of the device.

[0050] The working process of the extrusion molding device in this embodiment is as follows: The wire 1 is passed through the shaft holes of the extrusion seat 10, the third die core 40, the first die core 20, and the second die core 30, and connected to the winding traction device; shielding material (such as metallized plastic granules) is added to the extruder and conveyed to the first channel 203 of the first die core 20; the motor 802 of the drive mechanism is started, driving the eccentric wheel 804 to rotate. When the end of the drive bar hole 8031 ​​contacts the pin 404, the drive slider 803 drives the third die core 40 to move axially forward, further inserting the isolation part 401 into the connection. Inside channel 202, when the end of the third mold core 40 contacts the valve core 70, the third mold core 40 compresses the valve core 70, causing the return spring 701 to be compressed. This aligns the position of the through hole 702 with the position of the first channel 203, thus opening the first channel 203. Simultaneously, the third mold core 40 blocks the third channel 205, meaning the third channel 205 is misaligned with the annular groove 403. At this time, the shielding material inside the first channel 203 enters the outer forming cavity 50 and the inner forming cavity 60 through the second channel 204 to form the outer shielding layer 22 and the inner shielding layer 21. As the eccentric wheel 804 rotates, it causes the drive slider 803 to slide in the opposite direction. When the other end of the drive bar hole 8031 ​​contacts the pin 404, the drive slider 803 drives the third mold core 40 to move axially backward. When the third mold core 40 releases its pressure on the valve core 70, the return spring 701 pushes the valve core 70 to reset. The through hole 702 on the valve core 70 is misaligned with the first channel 203, and the first channel 203 is closed again. When the third mold core 40 moves backward to connect with the annular groove 403 and the third channel 205, the shield in the first channel 203... The material enters the annular groove 403 through the third channel 205, and then enters the connecting channel 202 from the end of each isolation part 401 through each fourth channel 402, thereby forming the connecting part 23 in the connecting channel 202, and fixing the formed outer shielding layer 22 and inner shielding layer 21 together; as the eccentric wheel 804 rotates continuously, the core shielding layer 2 covering the outside of the conductor 1 is continuously formed, and multiple sets of connecting parts 23 with S-shaped cross sections are formed at intervals between the inner shielding layer 21 and the outer shielding layer 22, thereby producing a lotus root-shaped low capacitance coaxial cable.

[0051] The lotus root-like structure produced in this way can produce adaptive deformation when the low capacitance coaxial cable is compressed or bent, reducing bending resistance and making it easier for the core shielding layer 2 to bend synchronously with the conductor 1, breaking the rigid connection of the shielding layer as a whole, further reducing the overall rigidity of the cable and improving flexibility.

[0052] like Figure 3 , Figure 4 as well as Figure 9 As shown, in the extrusion molding apparatus of this embodiment, an adjustment mechanism is further provided at the other end of the drive slider 803 corresponding to the position of the drive bar hole 8031; the adjustment mechanism includes an adjustment seat 901 fixedly installed on the drive slider 803; an adjustment slide 902 is provided above the drive bar hole 8031 ​​and raised and lowered; a first slider 903 is horizontally slidably provided at one end of the adjustment slide 902, and a second slider 904 is slidably provided at the other end; the first slider 903 and the second slider 904 are arranged opposite to each other, and a tension spring 905 is connected between them; a first inclined surface is provided on the side of the second slider 904 facing away from the first slider 903, and a second inclined surface is provided on the side of the drive bar hole 8031 ​​corresponding to the second slider 904, which cooperates with the first inclined surface; the first inclined surface is kept in contact with the second inclined surface under the elastic force of the tension spring 905; a pin 404 is located between the first slider 903 and the second slider 904.

[0053] Specifically, the adjustment of the slide 902 can be achieved by the bolt 906. Rotating the bolt 906 will drive the adjustment slide 902 to move up and down. When the adjustment slide 902 moves down, the first inclined surface and the second inclined surface cooperate to push the second slider 904 closer to the first slider 903, reducing the distance between them, thereby reducing the dwell time of the third mold core 40 at the front stop and rear stop positions, and increasing the stroke of the third mold core 40. Conversely, when the adjustment slide 902 moves up, the tension spring 905 pushes the second slider 904 to reset, increasing the distance, thereby reducing the dwell time of the third mold core 40 at the front stop and rear stop positions, and reducing the stroke of the third mold core 40. In this way, the time when the valve core 70 is lifted can be adjusted, thereby controlling the amount of shielding material entering the outer molding cavity 50 and the inner molding cavity 60. In this way, by controlling the forward movement distance of the inner shielding layer 21 and the outer shielding layer 22 after molding, a low-capacitance coaxial line with a lotus root structure of multiple sets of different spacings can be obtained.

[0054] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made to the structure, features and principles described in the claims of this patent application are included within the protection scope of this patent application.

Claims

1. An extrusion molding apparatus for fabricating a lotus root-like structure low-capacitance coaxial cable, characterized in that, The lotus root-shaped low-capacitance coaxial cable includes a conductor and a core shielding layer covering the outside of the conductor; the core shielding layer includes an inner shielding layer and an outer shielding layer, and the outer wall of the inner shielding layer and the inner wall of the outer shielding layer are connected by a discontinuously arranged connecting part, and the cross-section of the connecting part is non-linear. The extrusion molding apparatus includes an extrusion seat; the extrusion end of the extrusion seat is provided with a first die core, a second die core, and a third die core arranged coaxially. The first die core has a plurality of extrusion molding parts extending axially and distributed around the axis at one end facing away from the extrusion seat; a connecting channel is formed between two adjacent extrusion molding parts, the cross-sectional shape of which is adapted to the cross-sectional shape of the connecting part; The second mold core is located at the end of the first mold core facing away from the extrusion seat; the end of the second mold core facing away from the first mold core is provided with an extrusion sleeve portion; the extrusion sleeve portion is sleeved on the outside of the extrusion molding portion; an outer molding cavity is formed between the inner wall of the extrusion sleeve portion and the outer wall of the extrusion molding portion; an inner molding cavity is formed between the inner wall of the extrusion molding portion and the outer wall of the wire; the connecting channel connects the outer molding cavity and the inner molding cavity; One end of the third die core is movably disposed in the shaft hole of the extrusion seat, and the other end extends movably into the shaft hole of the first die core; the end face of the other end of the third die core is provided with a plurality of isolation parts extending axially and distributed around the axis; the cross-sectional shape of the isolation parts is adapted to the cross-sectional shape of the connecting channel; the isolation parts are inserted into the connecting channel one by one, thereby controlling the effective length of the connecting channel in the axial direction.

2. The extrusion molding apparatus according to claim 1, characterized in that, Multiple sets of connecting parts are provided between the inner shielding layer and the outer shielding layer along the axis of the conductor. Each set of connecting parts consists of multiple connecting parts evenly distributed around the axis of the conductor in the circumferential direction.

3. The extrusion molding apparatus according to claim 1, characterized in that, The cross-sectional shape of the connecting part is S-shaped.

4. The extrusion molding apparatus according to claim 1, characterized in that, The thickness of the connecting part is less than the thickness of the outer shielding part and the thickness of the inner shielding part.

5. The extrusion molding apparatus according to claim 1, characterized in that, The first mold core is provided with at least one first channel; the first mold core is also provided with at least one second channel; one end of the at least one second channel is connected to the first channel, and the other end is connected to the outer molding cavity and the inner molding cavity; for each first channel in the first mold core, a valve core is provided at the end of the first channel near the second channel, which is perpendicular to the first channel and is used to control the opening and closing of the first channel and the second channel; the first mold core is also provided with at least one third channel connected to the end of the first channel away from the second channel; The third mold core is provided with a fourth channel corresponding to each isolation part; the fourth channel penetrates the isolation part along the length direction of the corresponding isolation part; the outer wall of the third mold core is also provided with an annular groove that communicates with each fourth channel; when the third mold core moves to the position where the annular groove corresponds to the third channel, the annular groove communicates with the first channel through the third channel.

6. The extrusion molding apparatus according to claim 5, characterized in that, The number of the first channel, the number of the second channel, and the number of the third channel all correspond one-to-one with the number of the fourth channel.

7. The extrusion molding apparatus according to claim 5, characterized in that, A return spring is connected between the valve core and the first mold core; the valve core has a through hole extending through it radially; under the elastic force of the return spring, the valve core extends into the shaft hole of the first mold core, so that the through hole on the valve core is misaligned with the first channel.

8. The extrusion molding apparatus according to claim 1, characterized in that, The cross-sectional shape of the extrusion molding section, the connecting channel, and the isolation section are all S-shaped.

9. The extrusion molding apparatus according to claim 1, characterized in that, The outer wall of one end of the third mold core is provided with a pin; the extrusion seat is provided with a clearance strip hole for the pin to pass through the extrusion seat; The extrusion seat is also provided with a drive mechanism for driving the third die core to reciprocate axial linear motion via a pin.

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