Three-layer co-extrusion die with pressure control system

Abstract

The invention relates to the technical field of wire and cable production and processing, in particular to a three-layer co-extrusion die with a pressure control system, which comprises a casing and a pressure control mechanism. Three mold cores are arranged in the machine shell and sequentially comprise the first mold core, the second mold core and the third mold core from the feeding direction to the discharging direction, a mold sleeve is arranged at the end, away from the second mold core, of the third mold core, and the axis of the first mold core, the axis of the second mold core, the axis of the third mold core and the axis of the mold sleeve are all located on the same straight line. Material injection channels are formed among the first mold core, the second mold core, the third mold core and the mold sleeve; the first mold core, the second mold core and the third mold core can move in the axis direction of the mold core, and the three sets of pressure control mechanisms are arranged and used for controlling the first mold core, the second mold core and the third mold core to move correspondingly. The function of adjusting the area of the cross section of the discharging end of the material injection channel is achieved, and the problem that three-layer co-extrusion glue seams affect the quality of an insulating layer is solved.

Description

Technical Field

[0001] The invention relates to the technical field of production and processing of electric wires and cables, and in particular to a three-layer co-extrusion die with a pressure control system. Background Art

[0002] Cables consist of conductors and multiple insulating layers wrapped around the conductors. In the production and processing of cables, the traditional technology usually extrude one layer first and then another. This extrusion process will result in the cross-section between layers not being tight and smooth, and there will be impurities or air gaps, which will affect the quality of the insulation layer.

[0003] To this end, a Chinese patent with authorization announcement number CN109910262B discloses a three-layer co-extrusion head for a two-color four-part insulated cable, which adopts a three-layer diverter, and arranges an inner mold core, a middle mold core and an inner layer core in the casing. The insulating material A feed flow channel and the insulating material B feed flow channel are used to feed and co-extrude to form an interval and crossed two-color insulation layer. In addition, the sheath feed flow channel is used to feed and co-extrude to form a sheath wrapped around the two-color insulation layer; in this way, the two-color four-part insulated wire core and the sheath can be formed in one time, which simplifies the processing technology and fills the technical gap of the integrated molding of the two-color insulation layer and the sheath in the cable field.

[0004] However, when this method is used to produce cables, "glue seam" defects may occasionally appear outside the insulation layer. This defect manifests itself as an obvious seam line outside the insulation shielding layer. In severe cases, this seam line can cause the surface of the insulation layer and the insulation shielding layer to be rough, and may even have depressions. These defects can cause an imbalance in the field strength of the insulation layer and uneven distribution. In actual life use, it is more likely to cause breakdown than normal cables, which greatly reduces the service life of the cable. Summary of the invention

[0005] In view of the above problems, a three-layer co-extrusion die with a pressure control system is provided, which solves the problem that the glue seam of the three-layer co-extrusion affects the quality of the insulation layer by adjusting the positions of the first mold core, the second mold core and the third mold core.

[0006] In order to solve the problems of the prior art, the present invention provides a three-layer co-extrusion mold with a pressure control system, including a casing and a pressure control mechanism; three mold cores are arranged in the casing, and the three mold cores are respectively a first mold core, a second mold core and a third mold core from a feeding direction to a discharging direction, and a mold sleeve is arranged at an end of the third mold core away from the second mold core, and the axes of the first mold core, the second mold core, the third mold core and the mold sleeve are all on the same straight line; injection channels are arranged between the first mold core, the second mold core, the third mold core and the mold sleeve, and a conductor shielding layer flow channel is arranged between the first mold core and the second mold core, an insulating layer flow channel is arranged between the second mold core and the third mold core, and an insulating shielding layer channel is arranged between the third mold core and the mold sleeve; the first mold core, the second mold core and the third mold core can move along their axial directions, and three groups of pressure control mechanisms are arranged, and the three groups of pressure control mechanisms are respectively used to control the movement of the first mold core, the second mold core and the third mold core.

[0007] Preferably, the injection channel is composed of an injection pipe, an injection port opened on the casing and a material guide groove opened on the mold core; the injection pipe is arranged on the casing, the injection pipe is connected with the material guide groove through the injection port, and the injection port is arranged between the feed end and the discharge end of the material guide groove.

[0008] Preferably, the pressure control mechanism includes an adjusting component, a driving component and a reduction transmission component; the adjusting components of the three groups of pressure control mechanisms are respectively connected to the first mold core, the second mold core and the third mold core; the driving component is connected to the adjusting component through the reduction transmission component.

[0009] Preferably, the adjustment component includes a control ring and an isolation layer; the control ring is rotatably connected to the mold core through a bearing; the isolation layer is connected to the casing, and a threaded section is provided on the outer surface of the isolation layer, and the control ring is threadedly connected to the threaded section of the isolation layer.

[0010] Preferably, the drive assembly includes a mounting seat, a bracket, a transmission shaft and a rotating handle; the mounting seat is arranged on the casing, and the bracket is connected to the mounting seat; the transmission shaft is rotatably arranged on the bracket, and the transmission shaft is transmission-connected to the control ring through a reduction transmission assembly; the rotating handle is connected to the transmission shaft.

[0011] Preferably, the reduction transmission assembly includes a bevel gear ring, a first rotating shaft and a first bevel gear; the bevel gear is sleeved on the control ring; the first rotating shaft is rotatably set on the housing, and the first rotating shaft is transmission connected to the transmission shaft; the first bevel gear is slidingly sleeved on the first rotating shaft, a support is provided on the control ring, the first bevel gear is rotationally connected to the support, and the first bevel gear is meshingly connected to the bevel gear ring.

[0012] Preferably, a second rotating shaft is provided on the mounting seat, and a second bevel gear is sleeved on the second rotating shaft and the transmission shaft, and the two second bevel gears are meshingly connected; a pulley is sleeved on the first rotating shaft and the second rotating shaft, and a transmission belt is sleeved on the pulley, and the two pulleys are connected by the transmission belt.

[0013] Preferably, a flange seat is provided on the mold sleeve, and a locking bolt is provided on the flange seat, and the locking bolt passes through the mold sleeve and is connected to the casing.

[0014] Preferably, at least three through holes are provided on the flange seat, each through hole is provided with an adjusting bolt, and the multiple adjusting bolts are distributed in a circular array about the axis of the mold sleeve; the inner wall of the through hole is provided with an internal thread, and the adjusting bolt is threadably matched with the internal thread of the through hole.

[0015] Preferably, a filter plate is provided in the injection port, a connecting seat is provided on the filter plate, and a pressure sensor is provided on the connecting seat, and the connecting seat is connected to the frame via the pressure sensor.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention adjusts the cross-sectional area of ​​the discharge end of the injection channel by adjusting the positions of the first mold core, the second mold core and the third mold core. When the cross-sectional area of ​​the discharge end is reduced while the extrusion speed remains unchanged, the extrusion pressure increases, thereby making the conductor shielding layer, the insulation layer and the insulation shielding layer more closely bonded, reducing or even avoiding the appearance of the glue seam. The problem of the glue seam of the three-layer co-extrusion affecting the quality of the insulation layer is solved.

[0017] 2. The present invention realizes the function of adjusting the positions of the first mold core, the second mold core and the third mold core through the adjustment component, the drive component and the reduction transmission component, thereby achieving the effect of adjusting the gap between the first mold core, the second mold core and the third mold core, and then respectively controlling the discharge pressure of the first tapered hole, the second tapered hole and the third tapered hole, and improving the adjustment accuracy through the transmission of the reduction transmission component, thereby improving the adjustment efficiency of the operator.

[0018] 3. The present invention realizes the function of pushing or pulling the mold core to move through the control ring and the isolation layer. The bearing is preferably a deep groove ball bearing. The friction and wear between the control ring and the mold core are reduced by setting the bearing. When adjusting the position of the mold core, the operator drives the control ring through the drive assembly, and the drive assembly drives the control ring to rotate through the reduction transmission assembly. The control ring is threadedly connected to the threaded section of the isolation layer. When the isolation layer remains fixed, the control ring will move along its axis when rotating, and then drive the mold core connected to it through the control ring to move, thereby adjusting the position of the mold core. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a three-dimensional schematic diagram of a three-layer co-extrusion die with a pressure control system according to the present invention.

[0020] Figure 2 It is a cross-sectional schematic diagram of a three-layer co-extrusion die with a pressure control system according to the present invention.

[0021] Figure 3 The present invention Figure 2A local enlarged schematic diagram of point A in the middle.

[0022] Figure 4 The present invention Figure 2 A local enlarged schematic diagram of point B in the middle.

[0023] Figure 5 The present invention is a three-dimensional cross-sectional schematic diagram of a pressure control mechanism in a three-layer co-extrusion die with a pressure control system.

[0024] Figure 6 It is a three-dimensional schematic diagram of a pressure control mechanism in a three-layer co-extrusion die with a pressure control system of the present invention.

[0025] Figure 7 It is a three-dimensional schematic diagram of the cooperation between a frame and a pressure control mechanism in a three-layer co-extrusion mold with a pressure control system of the present invention.

[0026] Figure 8 The utility model is a three-dimensional schematic diagram of the cooperation between a mold sleeve and a flange seat in a three-layer co-extrusion mold with a pressure control system of the present invention.

[0027] Fig. 9 The utility model is a three-dimensional exploded schematic diagram of the cooperation between a mold sleeve and a flange seat in a three-layer co-extrusion mold with a pressure control system of the present invention.

[0028] Fig.10 The present invention is a schematic cross-sectional view of a filter sheet in a three-layer co-extrusion die with a pressure control system.

[0029] The numbers in the figure are: 1, housing; 11, first mold core; 12, second mold core; 13, third mold core; 14, mold sleeve; 15, injection channel; 151, injection pipe; 152, injection port; 153, guide groove; 154, filter plate; 1541, connecting seat; 16, first tapered hole; 17, second tapered hole; 18, third tapered hole; 2, pressure control mechanism; 21, adjustment component; 211, control ring; 2111, bearing; 2112, support; 2 12. Isolation layer; 2121. Threaded section; 22. Drive assembly; 221. Mounting seat; 222. Bracket; 223. Transmission shaft; 224. Rotating handle; 23. Reduction transmission assembly; 231. Bevel gear ring; 232. First rotating shaft; 233. First bevel gear; 234. Second rotating shaft; 235. Second bevel gear; 236. Pulley; 237. Transmission belt; 3. Flange seat; 31. Sealing gasket; 32. Locking bolt; 33. Adjusting bolt. DETAILED DESCRIPTION

[0030] In order to further understand the features, technical means, specific objectives and functions of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] Reference Figure 1-Figure 3 A three-layer co-extrusion die with a pressure control system comprises a housing 1 and a pressure control mechanism 2; the housing 1 is provided with three mold cores, which are a first mold core 11, a second mold core 12 and a third mold core 13 in order from a feeding direction to a discharging direction; a mold sleeve 14 is provided at one end of the third mold core 13 away from the second mold core 12, and the axes of the first mold core 11, the second mold core 12, the third mold core 13 and the mold sleeve 14 are all on the same straight line; ... An injection channel 15 is provided between the sleeves 14, and a conductor shielding layer flow channel is provided between the first mold core 11 and the second mold core 12, an insulating layer flow channel is provided between the second mold core 12 and the third mold core 13, and an insulating shielding layer channel is provided between the third mold core 13 and the mold sleeve 14; the first mold core 11, the second mold core 12 and the third mold core 13 can move along their axial direction, and three groups of pressure control mechanisms 2 are provided, and the three groups of pressure control mechanisms 2 are respectively used to control the movement of the first mold core 11, the second mold core 12 and the third mold core 13.

[0032] The present invention realizes the function of adjusting the cross-sectional area of ​​the discharge end of the injection channel 15 by adjusting the positions of the first mold core 11, the second mold core 12 and the third mold core 13. When the cross-section of the discharge end is reduced under the condition of unchanged extrusion speed, the extrusion pressure is increased, thereby making the conductor shielding layer, the insulating layer and the insulating shielding layer more closely bonded, reducing or even avoiding the appearance of the glue seam. The problem of the three-layer co-extrusion glue seam affecting the quality of the insulating layer is solved. The discharge end of the injection channel 15 is a tapered hole, and the discharge ends of the three injection channels 15 are the first tapered hole 16, the second tapered hole 17 and the third tapered hole 18 respectively. The "glue seam" defect is manifested as an obvious seam line outside the insulating shielding layer. In severe cases, this line will cause the surface of the insulating layer and the insulating shielding layer to be rough, and may even be concave. These defects will cause the field strength of the insulating layer to be unbalanced and unevenly distributed. In actual life use, it is easier to cause breakdown than normal cables, resulting in a greatly reduced service life of the cable. The reason for the formation of this defect is that the pressure formed by the flow channel of the insulating shielding layer on the layer is not large enough, so that the insulating shielding layer and the insulating layer cannot be tightly bonded. To this end, a first mold core 11, a second mold core 12 and a third mold core 13 that can move along their axes are provided, and the positions of the first mold core 11, the second mold core 12 and the third mold core 13 are adjusted respectively by three sets of pressure control mechanisms 2, and the discharge ends of the three injection channels 15 are all tapered. When the operator controls the third mold core 13 to move toward the mold sleeve 14 through the pressure control mechanism 2, the distance between the third mold core 13 and the mold sleeve 14 is shortened, thereby reducing the cross-sectional area of ​​the discharge end of the insulating shielding layer channel, increasing the pressure, and increasing the extrusion pressure, so that the insulating layer and the insulating shielding layer are tightly combined, thereby avoiding the appearance of glue seams. Compared with the existing technical solutions, by increasing the discharge pressure of the discharge channel, it is less likely to have quality problems of glue seams, thereby improving the quality of the product, preventing product quality failures caused by glue seam defects, and avoiding cost losses.

[0033] Reference Figure 2 and Figure 4 The injection channel 15 is composed of an injection pipe 151, an injection port 152 opened on the casing 1 and a guide groove 153 opened on the mold core; the injection pipe 151 is arranged on the casing 1, the injection pipe 151 is connected with the guide groove 153 through the injection port 152, and the position of the injection port 152 is arranged between the feed end and the discharge end of the guide groove 153.

[0034] The present invention realizes the function of feeding the tapered hole at the head position through the injection pipe 151, the injection port 152 and the guide groove 153. The guide groove 153 is connected to the tapered hole. When the position of the mold core is adjusted, the position of the guide groove 153 moves accordingly. By extending the length of the guide groove 153, after the position of the mold core changes, the injection port 152 can still stably feed the guide groove 153, avoiding the situation of material breaking or blocking during the adjustment process.

[0035] Reference Figure 1 and Figure 2 : The pressure control mechanism 2 includes an adjusting component 21, a driving component 22 and a reduction transmission component 23; the adjusting components 21 of the three groups of pressure control mechanisms 2 are respectively connected to the first mold core 11, the second mold core 12 and the third mold core 13; the driving component 22 is connected to the adjusting component 21 through the reduction transmission component 23.

[0036] The present invention realizes the function of adjusting the positions of the first mold core 11, the second mold core 12 and the third mold core 13 through the adjustment component 21, the drive component 22 and the reduction transmission component 23, and achieves the effect of adjusting the gaps between the first mold core 11, the second mold core 12 and the third mold core 13, thereby respectively controlling the discharge pressures of the first tapered hole 16, the second tapered hole 17 and the third tapered hole 18, and improving the adjustment accuracy and the adjustment efficiency of the operator through the transmission of the reduction transmission component 23. Since the gaps between the first mold core 11, the second mold core 12 and the third mold core 13 are relatively small, it is necessary to control the adjustment speed during adjustment to avoid the situation where the extrusion pressure is too large or too small. The operator first drives the adjustment component 21 through the drive component 22, and controls the driving speed through the transmission of the reduction transmission component 23, and then drives the mold core connected thereto to move through the adjustment component 21, and after the adjustment is completed, it is necessary to adjust the mold core at the front end in sequence to avoid affecting the extrusion pressure of the tapered hole at the front end. For example, after the second mold core 12 is controlled to move toward the third mold core 13 by the pressure control mechanism 2, the distance between the first mold core 11 and the second mold core 12 will increase accordingly. It is necessary to control the first mold core 11 to move the same distance toward the third mold core 13, thereby stabilizing the extrusion pressure of the conductor shielding layer flow channel.

[0037] Reference Figure 2 , Figure 5 and Figure 6 : The adjustment component 21 includes a control ring 211 and an isolation layer 212; the control ring 211 is rotatably connected to the mold core through a bearing 2111; the isolation layer 212 is connected to the housing 1, and the outer surface of the isolation layer 212 is provided with a threaded section 2121, and the control ring 211 is threadedly connected to the threaded section 2121 of the isolation layer 212.

[0038] The present invention realizes the function of pushing or pulling the mold core to move through the control ring 211 and the isolation layer 212. The bearing 2111 is preferably a deep groove ball bearing. The friction and wear between the control ring 211 and the mold core are reduced by the setting of the bearing 2111. When adjusting the position of the mold core, the operator drives the control ring 211 through the drive assembly 22, and the drive assembly 22 drives the control ring 211 to rotate through the reduction transmission assembly 23. The control ring 211 is threadedly connected to the threaded section 2121 of the isolation layer 212. When the isolation layer 212 remains fixed, the control ring 211 will move along its axis when rotating, and then drive the mold core connected to it through the control ring 211 to move, so as to adjust the position of the mold core.

[0039] Reference Figure 2 , Figure 5-Figure 7 : The driving assembly 22 includes a mounting seat 221, a bracket 222, a transmission shaft 223 and a rotating handle 224; the mounting seat 221 is set on the housing 1, and the bracket 222 is connected to the mounting seat 221; the transmission shaft 223 is rotatably set on the bracket 222, and the transmission shaft 223 is transmission-connected to the control ring 211 through the reduction transmission assembly 23; the rotating handle 224 is sleeved on the transmission shaft 223.

[0040] The present invention realizes the function of driving the control ring 211 to rotate through the mounting seat 221, the bracket 222, the transmission shaft 223 and the rotating handle 224. The housing 1 is provided with a cavity for accommodating the pressure control mechanism 2, and two mounting seats 221 are provided. The two mounting seats 221 are respectively arranged at the two ends of the cavity, and the two ends of the bracket 222 are respectively connected to the two mounting seats 221. When adjusting the position of the mold core, the operator rotates the rotating handle 224, and the rotating handle 224 drives the transmission shaft 223 to rotate, and the transmission shaft 223 drives the control ring 211 to rotate through the reduction transmission assembly 23. When the control ring 211 rotates, it pushes or pulls the mold core to move to adjust the extrusion pressure.

[0041] Reference Figure 2 , Figure 5 and Figure 6 The reduction transmission assembly 23 includes a bevel gear ring 231, a first rotating shaft 232 and a first bevel gear 233; the bevel gear is sleeved on the control ring 211; the first rotating shaft 232 is rotatably set on the housing 1, and the first rotating shaft 232 is transmission-connected with the transmission shaft 223; the first bevel gear 233 is slidingly sleeved on the first rotating shaft 232, a support 2112 is provided on the control ring 211, the first bevel gear 233 is rotationally connected with the support 2112, and the first bevel gear 233 is meshingly connected with the bevel gear ring 231.

[0042] The present invention realizes the function of speed reduction transmission through the bevel gear ring 231, the first rotating shaft 232 and the first bevel gear 233. When the transmission shaft 223 rotates, the rotation speed of the control ring 211 is reduced by the transmission ratio of the first bevel gear 233 and the bevel gear ring 231, thereby relatively improving the adjustment accuracy of the core movement. When the operator rotates the rotating handle 224, the rotating handle 224 drives the transmission shaft 223 to rotate, and the transmission shaft 223 transmits the torque to the first rotating shaft 232 connected thereto, and the first rotating shaft 232 drives the first bevel gear 233 to rotate, and then the bevel gear ring 231 meshed with it is driven to rotate through the first bevel gear 233, and the bevel gear ring 231 drives the control ring 211 to rotate. After the control ring 211 moves, it drives the support 2112 to move, and then pulls the first bevel gear 233 to slide along the first rotating shaft 232 through the support 2112, and adjusts the position of the first bevel gear 233, so that the first bevel gear 233 is always meshed with the bevel gear ring 231.

[0043] Reference Figure 2 , Figure 5 and Figure 6 : A second rotating shaft 234 is provided on the mounting seat 221, and a second bevel gear 235 is sleeved on the second rotating shaft 234 and the transmission shaft 223, and the two second bevel gears 235 are meshingly connected; a pulley 236 is sleeved on the first rotating shaft 232 and the second rotating shaft 234, and a transmission belt 237 is sleeved on the pulley 236, and the two pulleys 236 are connected by the transmission belt 237.

[0044] The present invention realizes the function of extending the transmission distance through the second rotating shaft 234, the second bevel gear 235, the pulley 236 and the transmission belt 237, so that the operator can stabilize the effect of driving the control ring 211 to rotate by turning the rotating handle 224. When adjusting the core, it is necessary to adjust the multiple cores at the front end in turn. To this end, three sets of pressure control mechanisms 2 for adjustment need to be set at three cores. To this end, it is necessary to control the transmission distance of the transmission shaft 223 and the control ring 211. The use of the pulley 236 and the transmission belt 237 to replace the extension of the transmission shaft 223 can not only reduce costs, but also avoid the operator's alignment adjustment when installing the long shaft. With different transmission distances, the operator only needs to install transmission belts 237 of different lengths. And when performing maintenance, it is only necessary to replace the corresponding transmission belt 237, which significantly improves the maintenance portability. And the transmission belt 237 has good elasticity and can play a buffering role during the working process. The overload protection function of the transmission belt 237 can also avoid the situation of severe wear of the gear.

[0045] Reference Figure 8-Figure 10 : A flange seat 3 is arranged on the mold sleeve 14, and a locking bolt 32 is arranged on the flange seat 3. The locking bolt 32 passes through the mold sleeve 14 and is connected to the casing 1.

[0046] The die sleeve 14 is fixed to the housing 1 by the flange seat 3 and the locking bolts 32 to prevent the vibration generated during the extrusion process from affecting the position of the die sleeve 14. A sealing gasket 31 is provided between the flange seat 3 and the die sleeve 14. The flange seat 3 compresses the sealing gasket 31 by the pressure generated by the locking bolts 32 to improve the sealing performance of the extrusion system.

[0047] Reference Figure 8-Figure 10 At least three through holes are provided on the flange seat 3, each of which is provided with an adjusting bolt 33, and the multiple adjusting bolts 33 are distributed in a circular array about the axis of the mold sleeve 14; the inner wall of the through hole is provided with an internal thread, and the adjusting bolt 33 is threadedly matched with the internal thread of the through hole.

[0048] The present invention realizes the function of adjusting the position of the die sleeve 14 by adjusting the bolt 33. In order to ensure the fixing quality of the extrusion process, it is necessary to ensure the centering degree of the die sleeve 14. To this end, an adjusting bolt 33 is provided on the flange seat 3, and the installation depth of the adjusting bolt 33 is controlled by rotating the adjusting bolt 33, so that the adjusting bolt 33 abuts against the die sleeve 14, and then the adjusting bolt 33 provides pressure to the die sleeve 14, and the position of the die sleeve 14 is adjusted by adjusting the pressure on the die sleeve 14 in all directions.

[0049] Reference Fig.10 : A filter plate 154 is provided in the injection port 152, a connecting seat 1541 is provided on the filter plate 154, and a pressure sensor is provided on the connecting seat 1541, and the connecting seat 1541 is connected to the frame through the pressure sensor.

[0050] The present invention realizes the function of filtering the raw material through the filter 154, the connecting seat 1541 and the pressure sensor on the connecting seat 1541, and at the same time of filtering, the resistance of the raw material transmission is sensed by the pressure sensor on the connecting seat 1541. The pressure sensor is preferably a piezoelectric ceramic. After the operator adjusts the position of the core, the extrusion pressure changes accordingly. During the processing, if the extrusion pressure is too large for a long time, it may affect the circulation of the raw material. For this reason, a pressure sensor is installed on the filter 154 set at the injection port 152, and the pressure on the filter 154 is sensed by the pressure sensor. In the injection channel 15, the flow of the material follows the principle of pressure difference drive. According to the Bernoulli equation and the continuity equation, the extrusion pressure will produce a pressure drop when passing through the filter 154, and this pressure drop is related to factors such as the resistance characteristics of the filter 154 and the extrusion flow rate. The pressure on the filter 154 can be measured by a suitable pressure sensor, and can be used as an important basis for inferring the extrusion pressure. When the extrusion pressure is too high, the pressure on the filter 154 also increases, and then the signal fed back by the pressure sensor is used to determine whether the extrusion pressure is within a specified range.

[0051] The above embodiments only express one or several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A three-layer co-extrusion die with a pressure control system, characterized in that: It comprises a casing (1) and a pressure control mechanism (2); Three mold cores are arranged in the housing (1), and the three mold cores are a first mold core (11), a second mold core (12), and a third mold core (13) in order from the feeding direction to the discharging direction; a mold sleeve (14) is arranged at one end of the third mold core (13) away from the second mold core (12); and axes of the first mold core (11), the second mold core (12), the third mold core (13), and the mold sleeve (14) are all on the same straight line; Injection channels (15) are provided between the first mold core (11), the second mold core (12), the third mold core (13) and the mold sleeve (14); a conductor shielding layer flow channel is provided between the first mold core (11) and the second mold core (12); an insulating layer flow channel is provided between the second mold core (12) and the third mold core (13); and an insulating shielding layer channel is provided between the third mold core (13) and the mold sleeve (14); The first mold core (11), the second mold core (12) and the third mold core (13) are capable of moving along their axial directions. Three groups of pressure control mechanisms (2) are provided. The three groups of pressure control mechanisms (2) are used to control the movement of the first mold core (11), the second mold core (12) and the third mold core (13), respectively.

2. A three-layer co-extrusion die with a pressure control system according to claim 1, characterized in that: The injection channel (15) is composed of an injection pipe (151), an injection port (152) provided on the housing (1), and a guide groove (153) provided on the mold core; The injection pipe (151) is arranged on the casing (1), the injection pipe (151) is connected to the material guide groove (153) through the injection port (152), and the injection port (152) is arranged between the feeding end and the discharging end of the material guide groove (153).

3. A three-layer co-extrusion die with a pressure control system according to claim 1, characterized in that: The pressure control mechanism (2) comprises an adjustment component (21), a drive component (22) and a reduction transmission component (23); The adjustment components (21) of the three sets of pressure control mechanisms (2) are respectively connected to the first mold core (11), the second mold core (12) and the third mold core (13); The driving assembly (22) is transmission-connected to the adjusting assembly (21) via the reduction transmission assembly (23).

4. A three-layer co-extrusion die with a pressure control system according to claim 3, characterized in that: The regulating component (21) comprises a control ring (211) and an isolation layer (212); The control ring (211) is rotatably connected to the mold core via a bearing (2111); The isolation layer (212) is connected to the housing (1), and a threaded section (2121) is provided on the outer surface of the isolation layer (212), and the control ring (211) is threadedly connected to the threaded section (2121) of the isolation layer (212).

5. A three-layer co-extrusion die with a pressure control system according to claim 4, characterized in that: The driving assembly (22) comprises a mounting seat (221), a bracket (222), a transmission shaft (223) and a rotating handle (224); The mounting seat (221) is disposed on the housing (1), and the bracket (222) is connected to the mounting seat (221); The transmission shaft (223) is rotatably disposed on the bracket (222), and the transmission shaft (223) is transmission-connected to the control ring (211) via a reduction transmission assembly (23); The rotating handle (224) is sleeved on the transmission shaft (223).

6. A three-layer co-extrusion die with a pressure control system according to claim 5, characterized in that: The reduction transmission assembly (23) comprises a bevel gear ring (231), a first rotating shaft (232) and a first bevel gear (233); The bevel gear is sleeved on the control ring (211); The first rotating shaft (232) is rotatably disposed on the housing (1), and the first rotating shaft (232) is drivingly connected to the transmission shaft (223); The first bevel gear (233) is slidably sleeved on the first rotating shaft (232); a support (2112) is provided on the control ring (211); the first bevel gear (233) is rotationally connected to the support (2112); and the first bevel gear (233) is meshingly connected to the bevel gear ring (231).

7. A three-layer co-extrusion die with a pressure control system according to claim 6, characterized in that: A second rotating shaft (234) is provided on the mounting seat (221), and a second bevel gear (235) is sleeved on the second rotating shaft (234) and the transmission shaft (223), and the two second bevel gears (235) are meshingly connected; A pulley (236) is sleeved on each of the first rotating shaft (232) and the second rotating shaft (234); a transmission belt (237) is sleeved on the pulley (236); and the two pulleys (236) are connected via the transmission belt (237).

8. The three-layer co-extrusion die with a pressure control system according to claim 1, characterized in that: A flange seat (3) is provided on the mold sleeve (14), and a locking bolt (32) is provided on the flange seat (3). The locking bolt (32) passes through the mold sleeve (14) and is connected to the housing (1).

9. A three-layer co-extrusion die with a pressure control system according to claim 8, characterized in that: At least three through holes are formed on the flange seat (3), each through hole is provided with an adjusting bolt (33), and the plurality of adjusting bolts (33) are distributed in a circular array about the axis of the mold sleeve (14); An internal thread is formed on the inner wall of the through hole, and the adjusting bolt (33) is threadably matched with the internal thread of the through hole.

10. The three-layer co-extrusion die with a pressure control system according to claim 2, characterized in that: A filter sheet (154) is provided in the injection port (152), a connecting seat (1541) is provided on the filter sheet (154), a pressure sensor is provided on the connecting seat (1541), and the connecting seat (1541) is connected to the frame via the pressure sensor.

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