Double-layer co-extrusion die feeding structure capable of balancing pressure and die

Abstract

The utility model relates to the technical field of extrusion dies, in particular to a double-layer co-extrusion die feeding structure capable of balancing pressure and a die, the double-layer co-extrusion die feeding structure capable of balancing pressure comprises an outer flow divider, a flow divider outer sleeve and an adjusting sleeve, the flow divider outer sleeve is provided with a feeding port, the flow divider outer sleeve is fixedly connected with the adjusting sleeve, and the outer flow divider is installed in an inner cavity of the flow divider outer sleeve. The outer flow divider further extends into the inner cavity of the adjusting sleeve, an eccentric section is arranged on the outer flow divider and located in the inner cavity of the flow divider outer sleeve, the distance from the top of the eccentric section to the top of the inner cavity of the flow divider outer sleeve is smaller than that from the bottom of the eccentric section to the bottom of the inner cavity of the flow divider outer sleeve, and the length of the top of the eccentric section is larger than that of the bottom of the eccentric section. According to the double-layer co-extrusion die feeding structure capable of balancing the pressure, due to the arrangement of the eccentric section, the problem that the advancing speeds of outer-layer materials are different due to different pressures on the tops and the bottoms of the materials when the outer-layer materials advance along the die after entering the die can be solved, so that the outer-layer wall thickness of double-layer pipes produced by the die is uniform.

Description

Technical Field

[0001] The utility model relates to the technical field of extrusion dies, and more particularly to a double-layer co-extrusion die feeding structure with balanced pressure and a die. Background Art

[0002] Double-layer pipes are widely used in building drainage pipes, electrical wiring sheaths, and agricultural irrigation due to their corrosion resistance, high temperature resistance, and pressure resistance. In particular, conventional irrigation pipes are susceptible to moss growth when exposed to sunlight, which not only affects irrigation effectiveness but also can pollute crops, impacting the quality and yield of agricultural products. To prevent moss growth in irrigation pipes, existing technologies typically coat the outer wall of PVC pipes with a PP-R (polypropylene tripolymer) plastic layer, which reduces the likelihood of moss growth.

[0003] When using a mold to produce the above-mentioned double-layer tube, since the axis of the outer layer feed port of the mold does not coincide with the axis of the outer layer flow channel, the feed pressure of the mold is constant. During the feeding process, the movement direction of the outer layer material of the tube in the outer layer feed port is inconsistent with the movement direction in the outer layer flow channel. After the outer layer material of the tube enters the outer layer flow channel of the mold, the material at the bottom of the inner cavity of the outer layer flow channel moves a longer distance than the material at the top of the inner cavity of the outer layer flow channel. This causes the pressure on the material at the bottom of the inner cavity of the outer layer flow channel to be smaller than the pressure on the material at the top of the inner cavity of the outer layer flow channel when it moves forward. The forward speed of the material at the top of the inner cavity of the outer layer flow channel is greater than the forward speed of the material at the bottom of the inner cavity of the outer layer flow channel, which makes the thickness of the outer top of the double-layer tube produced by the mold greater than the thickness of the outer bottom, resulting in uneven tube wall thickness. Utility Model Content

[0004] The purpose of the present utility model is to overcome the shortcomings of the prior art in that the wall thickness of the produced molded pipes is uneven due to the different material forward speed and pressure at the top of the outer layer flow channel and the material forward speed and pressure at the bottom of the outer layer flow channel, and to provide a double-layer co-extrusion mold feeding structure and mold with balanced pressure. The mold feeding structure in the utility model can balance the pressure and forward speed of the material in the inner cavity of the outer layer flow channel, so that the wall thickness of the molded pipes produced by the mold is uniform.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] The application provides a pressure-balancing double-layer co-extrusion die feeding structure, which comprises an outer distributor, a distributor sleeve and an adjusting sleeve, the distributor sleeve is provided with a feeding port, the distributor sleeve is fixedly connected with the adjusting sleeve, the outer distributor is arranged in the inner cavity of the distributor sleeve and extends into the inner cavity of the adjusting sleeve, the inner cavity of the outer distributor is used for feeding inner-layer material, the outer distributor is provided with an eccentric section, the eccentric section is arranged in the inner cavity of the distributor sleeve, the distance E1 from the top of the eccentric section to the top of the inner cavity of the distributor sleeve is smaller than the distance E2 from the bottom of the eccentric section to the bottom of the inner cavity of the distributor sleeve, and the length L1 of the top of the eccentric section is larger than the length L2 of the bottom of the eccentric section.

[0007] During feeding, the inner-layer material is directly fed through the inner cavity of the outer distributor, the outer-layer material is fed into the gap between the outer distributor and the distributor sleeve through the feeding port, and then continuously advances in the gap between the outer distributor and the distributor sleeve until the gap between the adjusting sleeve and the outer distributor. However, when the material between the outer distributor and the distributor sleeve passes through the eccentric section, the pressure of the material is consumed by the gap between the eccentric section and the distributor sleeve, and the pressure consumption of the material in the top of the inner cavity of the gap is greater than that of the material in the bottom of the inner cavity of the gap, so that the pressure of the material in the top of the inner cavity of the gap is equal to that of the material in the bottom of the inner cavity of the gap, and the advancing speed of the material in the top of the inner cavity of the gap is equal to that of the material in the bottom of the inner cavity of the gap.

[0008] The pressure-balancing double-layer co-extrusion die feeding structure can solve the problem that the advancing speed of the material is different due to the different pressures of the top and bottom of the material when the outer-layer material advances in the die, and the wall thickness of the outer layer of the double-layer pipe produced by the die is uniform.

[0009] Furthermore, the distance E2 from the bottom of the eccentric segment to the bottom of the inner cavity of the diverter jacket is 2-3 times the distance E1 from the top of the eccentric segment to the top of the inner cavity of the diverter jacket, and the length L1 of the top of the eccentric segment is 2.5-3.5 times the length L2 of the bottom of the eccentric segment. Experimental measurements have shown that when the distance E2 from the bottom of the eccentric segment to the bottom of the inner cavity of the diverter jacket is 2-3 times the distance E1 from the top of the eccentric segment to the top of the inner cavity of the diverter jacket, and the length L1 of the top of the eccentric segment is 2.5-3.5 times the length L2 of the bottom of the eccentric segment, the pressure balancing effect of the outer layer material is better. The specific values ​​can be further adjusted according to the injection pressure and the material forward speed.

[0010] Furthermore, the external diverter is provided with a guide trough connected to the feed port, the guide trough is inclined and coiled on the external diverter, the bottom of the guide trough is closer to the adjustment sleeve than the top of the guide trough, the depth S2 of the bottom of the guide trough is less than the depth S1 of the top of the guide trough, the width B1 of the top of the guide trough is greater than the width B2 of the bottom of the guide trough, the top of the guide trough is connected to the feed port, and the width B1 of the top of the guide trough is the same as the width of the feed port. After the inclined eccentric guide trough is provided on the external diverter, the material flowing from the feed port into the surface of the external diverter can be balanced in pressure and velocity for the first time through the guide trough. The principle of pressure balance is the same as that of the eccentric section, which can further improve the pressure balance effect of the feed structure on the outer layer material.

[0011] Furthermore, the depth S1 of the top of the guide trough is 1-2 times the depth S2 of the bottom of the guide trough; and the width B1 of the top of the guide trough is 1.5-3 times the width B2 of the bottom of the guide trough. Experimental measurements have shown that when the depth S1 of the top of the guide trough is 1-2 times the depth S2 of the bottom of the guide trough, and the width B1 of the top of the guide trough is 1.5-3 times the width B2 of the bottom of the guide trough, the guide trough has a better pressure balancing effect on the outer layer material. The specific values ​​can be further adjusted according to the injection pressure and material advance speed.

[0012] Furthermore, a sidewall of the guide trough, near one end of the eccentric segment, is provided with a rounded corner connected to the eccentric segment, and the radius of the rounded corner at the top of the guide trough is greater than the radius of the rounded corner at the bottom of the guide trough. Providing the rounded corner on the sidewall of the guide trough, which is connected to the eccentric segment, enables material in the guide trough to flow smoothly into the gap between the eccentric segment and the diverter jacket.

[0013] Furthermore, the outer diverter is provided with a pressure-equalizing groove for equalizing material pressure. The pressure-equalizing groove and the material guide groove are located on either side of the eccentric section. The pressure-equalizing groove can accommodate material flowing out of the gap between the eccentric section and the diverter jacket. After entering the pressure-equalizing groove, the material will briefly stay there. The pressure of the material flowing out of the pressure-equalizing groove is more uniform, further improving the pressure-equalizing effect of the feed structure on the outer material.

[0014] Furthermore, an outer adjustment ring is installed on the side of the inner cavity of the adjustment sleeve close to the outer diverter. The outer adjustment ring is located in the mounting groove of the adjustment sleeve. The end of the outer adjustment ring close to the outer shell of the diverter is aligned with the pressure equalizing groove. The adjustment sleeve is provided with an adjustment bolt that can change the position of the outer adjustment ring in the mounting groove. The adjustment bolt is threadedly connected to the adjustment sleeve. The bottom of the adjustment bolt extends into the mounting groove and abuts against the outer side wall of the outer adjustment ring. The eccentricity of the outer adjustment ring in the mounting groove can be changed by adjusting the bolt. When the pressures received by different positions of the material flowing out of the pressure equalizing groove are still different, the eccentricity of the outer adjustment ring can be changed by rotating the adjustment bolt to further balance the pressure of the outer layer material.

[0015] Furthermore, the axis of the feed port is parallel to the inclination direction of the material guide trough. The device further includes an outer joint capable of communicating with an outer injection molding machine, the outer joint being mounted on the manifold housing. The outer joint is provided with a material guide hole capable of communicating with the outer injection molding machine, the axis of the material guide hole being parallel to the vertical direction, the bottom of the material guide hole being connected to the feed port, and a conical gasket being provided between the material guide hole and the feed port. The inner sidewall of the top of the conical gasket is aligned with the material guide hole, and the inner sidewall of the bottom of the conical gasket is aligned with the feed port. The axis of the feed port is parallel to the inclination direction of the material guide trough, allowing material in the feed port to more smoothly enter the material guide trough and continue to move along the material guide trough. After the outer layer joint is set, the material of the outer layer injection molding machine passes through the guide hole and the conical gasket in turn into the feed port. The setting of the vertical guide hole on the outer layer joint makes it easier for the feeding structure to be connected with the outer layer injection molding machine, and the setting of the conical gasket makes it easier for the material to enter the feed port from the guide hole.

[0016] A pressure-balanced double-layer co-extrusion mold comprises a feeding structure, an inner and outer layer diverter bracket, a converging core, a compression plate, a fixed core seat, a die, a core and a conical diverter. The feeding structure is the above-mentioned pressure-balanced double-layer co-extrusion mold feeding structure, the inner and outer layer diverter bracket is provided with an outer flow channel gap for allowing the outer layer material to pass through, the adjustment sleeve, the inner and outer layer diverter bracket, the compression plate and the die are fixedly connected in sequence, wherein the die is mounted on the compression plate through a clamping flange; the converging core is mounted on the inner and outer layer diverter bracket and extends into the inner cavity of the compression plate; the conical diverter, the fixed core seat and the core are connected in sequence, the conical diverter is mounted on the inner and outer layer diverter bracket and its conical section extends into the inner cavity of the outer diverter, the fixed core seat is located in the inner cavity of the converging core, and the core is mounted on the fixed core seat and extends into the inner cavity of the die. The outer flow channel includes the gap between the outer diverter and the diverter outer sleeve, the outer flow channel gap, and the gap between the confluence core and the compression plate; the inner flow channel includes the inner cavity of the outer diverter, the gap between the outer diverter and the conical diverter, the gap between the conical diverter and the inner and outer layer diverter brackets, and the gap between the fixed core seat and the compression plate; the main flow channel includes the gap between the die and the core; the outer flow channel and the inner flow channel merge at the entrance of the main flow channel.

[0017] When the mold is working, the inner layer material enters the inner flow channel through the inner cavity of the external diverter, and the outer layer material enters the outer flow channel through the feed port. The materials in the inner and outer flow channels advance to the inlet of the main flow channel and merge. The merged materials continue to advance along the main flow channel until they are extruded and formed to form a double-layer pipe.

[0018] The utility model provides a pressure-balanced double-layer co-extrusion die that can balance the pressure on the material entering the outer flow channel, so that after the pipe is extruded, the outer side of the double-layer pipe can be evenly distributed and the outer wall thickness of the double-layer pipe is uniform.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] The double-layer co-extrusion die feeding structure with balanced pressure of the present invention can solve the problem of different material advancing speeds caused by different pressures on the top and bottom of the outer layer material when it advances along the die after entering the die through the setting of the eccentric section, so that the outer wall thickness of the double-layer pipe produced by the die is uniform.

[0021] The double-layer co-extrusion die feeding structure with balanced pressure of the present invention can further balance the pressure of the outer layer material through the arrangement of the material guide groove, the pressure equalizing groove and the outer adjustment ring, so as to achieve the purpose of uniform outer wall thickness of the double-layer pipe produced by the die.

[0022] The utility model provides a pressure-balanced double-layer co-extrusion die that can balance the pressure on the material entering the outer flow channel, so that after the pipe is extruded, the outer side of the double-layer pipe can be evenly distributed and the outer wall thickness of the double-layer pipe is uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a double-layer co-extrusion die feeding structure with balanced pressure;

[0024] Figure 2 It is a double-layer co-extrusion die feeding structure with balanced pressure. Figure 1 A magnified view of part A in FIG;

[0025] Figure 3 It is a double-layer co-extrusion die feeding structure with balanced pressure. Figure 1 A magnified view of part B in FIG;

[0026] Figure 4 It is a double-layer co-extrusion die feeding structure with balanced pressure. Figure 1 Enlarged view of part C in ;

[0027] Figure 5 This is a structural diagram of a double-layer co-extrusion die with balanced pressure.

[0028] In the accompanying drawings: 1. External diverter; 2. Diverter outer sleeve; 3. Adjustment sleeve; 201. Feed port; 101. Eccentric section; 102. Material guide trough; 103. Pressure equalizing trough; 4. External adjustment ring; 301. Adjustment bolt; 5. Outer joint; 501. Material guide hole; 6. Conical gasket; 7. Inner and outer diverter bracket; 8. Converging core; 9. Compression plate; 10. Fixed core seat; 11. Clamping flange; 12. Mould; 13. Core; 14. Conical diverter; 15. Outer flow channel; 16. Inner flow channel; 17. Main flow channel. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific embodiments. The accompanying drawings are for illustrative purposes only and are schematic, not actual, representations. They should not be construed as limiting this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted from the drawings.

[0030] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right" and so on indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0031] Example 1

[0032] This embodiment is the first embodiment of a double-layer co-extrusion die feeding structure with balanced pressure. Figure 1 As shown, it includes an outer diverter 1, a diverter jacket 2 and an adjustment sleeve 3. The diverter jacket 2 is provided with a feed port 201. The diverter jacket 2 is fixedly connected to the adjustment sleeve 3. The outer diverter 1 is installed in the inner cavity of the diverter jacket 2. The outer diverter 1 also extends into the inner cavity of the adjustment sleeve 3. The inner cavity of the outer diverter 1 is used for the inner layer material to pass through. The outer diverter 1 is provided with an eccentric section 101, as shown Figure 2 and Figure 3 As shown, the eccentric segment 101 is located in the inner cavity of the diverter sleeve 2, the distance E1 from the top of the eccentric segment 101 to the top of the inner cavity of the diverter sleeve 2 is smaller than the distance E2 from the bottom of the eccentric segment 101 to the bottom of the inner cavity of the diverter sleeve 2, and the length L1 of the top of the eccentric segment 101 is greater than the length L2 of the bottom of the eccentric segment 101.

[0033] The working principle or working process of this embodiment is as follows:

[0034] During the feeding process, the inner layer of material is fed directly through the inner cavity of the outer diverter 1, and the outer layer of material enters the gap between the outer diverter 1 and the diverter jacket 2 through the feed port 201, and then continues to advance in the gap between the outer diverter 1 and the diverter jacket 2 until it enters between the adjustment sleeve 3 and the outer diverter 1. Normally, under constant feed pressure, the material at the bottom of the gap between the outer diverter and the diverter jacket is subjected to less pressure as it advances along the gap than the material at the top of the gap, and the material at the top of the gap advances faster than the material at the bottom of the gap. However, after the material passes through the eccentric section 101, since the distance E1 between the top of the eccentric section 101 and the top of the inner cavity of the diverter jacket 2 is smaller than the distance E2 between the bottom of the eccentric section 101 and the bottom of the inner cavity of the diverter jacket 2 and the length L1 of the top of the eccentric section 101 is larger than the length L2 of the bottom of the eccentric section 101, when the material between the external diverter 1 and the diverter jacket 2 passes through the eccentric section 101, the pressure on the material will be consumed by the gap between the eccentric section 101 and the diverter jacket 2 and the pressure consumption of the material at the top of the gap inner cavity is greater than the pressure consumption of the material at the bottom of the gap inner cavity, so as to achieve the purpose of making the pressure of the material at the top of the gap inner cavity the same as the pressure of the material at the bottom of the gap inner cavity, and then making the forward speed of the material at the top of the gap inner cavity the same as the forward speed of the material at the bottom of the gap inner cavity. At this time, the outer layer thickness of the double-layer pipe extruded from the mold can be evenly distributed.

[0035] The beneficial effects of this embodiment are as follows:

[0036] The balanced pressure double-layer co-extrusion die feeding structure in this scheme can solve the problem of different material advancing speeds caused by different pressures on the top and bottom of the outer layer material when it moves along the die after entering the die through the setting of the eccentric section 101, so that the outer wall thickness of the double-layer pipe produced by the die is uniform.

[0037] Example 2

[0038] This embodiment is a second embodiment of a double-layer co-extrusion die feeding structure with balanced pressure. Based on the first embodiment, this embodiment further defines the specific structure of the feeding structure.

[0039] Specifically, such as Figure 2 and Figure 3 As shown, the distance E2 from the bottom of the eccentric segment 101 to the bottom of the inner cavity of the diverter jacket 2 is 2-3 times the distance E1 from the top of the eccentric segment 101 to the top of the inner cavity of the diverter jacket 2, and the length L1 of the top of the eccentric segment 101 is 2.5-3.5 times the length L2 of the bottom of the eccentric segment 101.

[0040] Specifically, such as Figure 1As shown, the outer diverter 1 is provided with a guide trough 102 connected to the feed port 201. The guide trough 102 is tilted and coiled on the outer diverter 1. Its shape is as follows: Figure 1 As shown by the dotted line in FIG, the bottom of the guide groove 102 is closer to the adjustment sleeve 3 than the top of the guide groove 102. Figure 2 and Figure 4 As shown, the depth S2 of the bottom of the guide trough 102 is less than the depth S1 of the top of the guide trough 102, and the width B1 of the top of the guide trough 102 is greater than the width B2 of the bottom of the guide trough 102. The top of the guide trough 102 is connected to the feed inlet 201, and the width B1 of the top of the guide trough 102 is the same as the width of the feed inlet 201. The depth S1 of the top of the guide trough 102 is 1-2 times the depth S2 of the bottom of the guide trough 102; the width B1 of the top of the guide trough 102 is 1.5-3 times the width B2 of the bottom of the guide trough 102.

[0041] Specifically, such as Figure 1 As shown, the side wall of the guide trough 102 close to one end of the eccentric section 101 is provided with a chamfer connected to the eccentric section 101 , and the chamfer radius of the top of the guide trough 102 is larger than the chamfer radius of the bottom of the guide trough 102 .

[0042] Specifically, such as Figure 1 As shown, the external diverter 1 is also provided with a pressure-equalizing groove 103 for equalizing material pressure. The pressure-equalizing groove 103 and the material guide groove 102 are respectively located on either side of the eccentric section 101. An outer adjustment ring 4 is mounted on the side of the inner cavity of the adjustment sleeve 3 near the external diverter 1. The outer adjustment ring 4 is located in the mounting groove of the adjustment sleeve 3. The end of the outer adjustment ring 4 near the diverter outer sleeve 2 is aligned with the top of the pressure-equalizing groove 103. The adjustment sleeve 3 is provided with an adjusting bolt 301 for changing the position of the outer adjustment ring 4 in the mounting groove. The adjusting bolt 301 is threadedly connected to the adjustment sleeve 3. The bottom of the adjusting bolt 301 extends into the mounting groove and abuts against the outer side wall of the outer adjustment ring 4.

[0043] Specifically, such as Figure 1 As shown, the axis of the feed port 201 is parallel to the inclination direction of the guide trough 102. It also includes an outer joint 5 that can be connected to the outer injection molding machine. The outer joint 5 is installed on the diverter jacket 2 and is provided with a guide hole 501 that can be connected to the outer injection molding machine. The axis of the guide hole 501 is parallel to the vertical direction. The bottom of the guide hole 501 is connected to the feed port 201. A conical gasket 6 is provided between the guide hole 501 and the feed port 201. The inner sidewall of the top of the conical gasket 6 is aligned with the guide hole 501, and the inner sidewall of the bottom of the conical gasket 6 is aligned with the feed port 201.

[0044] The beneficial effects of this embodiment are as follows:

[0045] When the distance E2 from the bottom of the eccentric section 101 to the bottom of the inner cavity of the diverter jacket 2 is 2-3 times the distance E1 from the top of the eccentric section 101 to the top of the inner cavity of the diverter jacket 2, and the length L1 of the top of the eccentric section 101 is 2.5-3.5 times the length L2 of the bottom of the eccentric section 101, the pressure balancing effect of the outer layer material is better.

[0046] After the inclined eccentric guide trough 102 is provided on the outer diverter 1, the material flowing into the surface of the outer diverter 1 from the feed port 201 can be initially balanced in pressure and velocity through the guide trough 102, further improving the pressure balancing effect of the feed structure on the outer material. When the depth S1 of the top of the guide trough 102 is 1-2 times the depth S2 of the bottom of the guide trough 102; and the width B1 of the top of the guide trough 102 is 1.5-3 times the width B2 of the bottom of the guide trough 102, the guide trough 102 has a better pressure balancing effect on the outer material.

[0047] A chamfered corner connected to the eccentric section 101 is provided on the side wall of the guide trough 102 , so that the material in the guide trough 102 can flow smoothly into the gap between the eccentric section 101 and the diverter housing 2 .

[0048] The pressure-equalizing groove 103 is designed to accommodate material flowing out of the gap between the eccentric section 101 and the diverter jacket 2. After entering the pressure-equalizing groove 103, the material will briefly remain there. The pressure of the material flowing out of the pressure-equalizing groove 103 will be more uniform, further improving the pressure-equalizing effect of the feed structure on the outer material. The eccentricity of the outer adjustment ring 4 within the mounting groove can be varied by adjusting the bolt 301. If the pressures received by the material flowing out of the pressure-equalizing groove 103 at various locations remain different, the eccentricity of the outer adjustment ring 4 can be varied by rotating the adjusting bolt 301 to further equalize the pressure of the outer material.

[0049] The axis of the feed port 201 is parallel to the inclination direction of the guide trough 102, allowing the material in the feed port 201 to enter the guide trough 102 more smoothly and continue to move along the guide trough 102. After the outer layer joint 5 is installed, the material of the outer layer injection molding machine passes through the guide hole 501 and the conical gasket 6 in sequence to enter the feed port 201. The vertical guide hole 501 on the outer layer joint 5 makes it easier for the feed structure to communicate with the outer layer injection molding machine, and the conical gasket 6 makes it easier for the material to enter the feed port 201 from the guide hole 501.

[0050] Example 3

[0051] This embodiment is an embodiment of a pressure-balanced double-layer co-extrusion die. Figure 5As shown, including the feed structure, inner and outer layer diverter support 7, converging core 8, compression plate 9, fixed mold core seat 10, die 12, mold core 13 and tapered diverter 14, the feed structure is a pressure equalizing double-layer co-extrusion mold feed structure described in embodiment two, the inner and outer layer diverter support 7 is provided with an outer flow channel 15 gap for the outer layer material to pass through, the adjusting sleeve 3, the inner and outer layer diverter support 7, the compression plate 9 and the die 12 are sequentially fixedly connected, wherein the die 12 is installed on the compression plate 9 through the compression flange 11; the converging core 8 is installed on the inner and outer layer diverter support 7 and extends into the inner cavity of the compression plate 9; the tapered diverter 14, the fixed mold core seat 10 and the mold core 13 are sequentially connected, the tapered diverter 14 is installed on the inner and outer layer diverter support 7 and the tapered section thereof extends into the inner cavity of the outer diverter 1, the fixed mold core seat 10 is located in the inner cavity of the converging core 8, and the mold core 13 is installed on the fixed mold core seat 10 and extends into the inner cavity of the die 12. The outer flow channel 15 includes the gap between the outer diverter 1 and the diverter sleeve 2, the gap of the outer flow channel 15. The gap between the converging core 8 and the compression plate 9; the inner flow channel 16 includes the inner cavity of the outer diverter 1, the gap between the outer diverter 1 and the tapered diverter 14, the gap between the tapered diverter 14 and the inner and outer layer diverter support 7. The gap between the fixed mold core seat 10 and the compression plate 9; the total flow channel 17 includes the gap between the die 12 and the mold core 13; the outer flow channel 15 and the inner flow channel 16 converge at the inlet of the total flow channel 17.

[0052] The working principle of the embodiment is as follows:

[0053] When the mold is working, the inner layer material enters the inner flow channel 16 through the inner cavity of the outer diverter 1, and the outer layer material enters the outer flow channel 15 through the feed port 201. The materials in the inner flow channel 16 and the outer flow channel 15 converge after advancing to the inlet of the total flow channel 17, and the converged materials continue to advance along the total flow channel 17 until they are extruded and formed into a double-layer pipe.

[0054] The beneficial effects of the embodiment are as follows:

[0055] The pressure equalizing double-layer co-extrusion mold can balance the pressure of the material entering the outer flow channel 15, so that the outer side of the double-layer pipe can be uniformly distributed after the pipe is extruded, and the outer wall thickness of the double-layer pipe is uniform.

[0056] In the specific content of the above specific embodiments, any non-contradictory combination of technical features can be made, and in order to make the description simple, not all possible combinations of the above technical features are described, but as long as the combination of these technical features does not exist Contradiction, it should be considered as the scope recorded in this specification.

[0057] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art will be able to make other variations or modifications based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A double-layer co-extrusion die feeding structure with balanced pressure, characterized in that: The invention comprises an external diverter (1), a diverter outer sleeve (2) and an adjustment sleeve (3), wherein the diverter outer sleeve (2) is provided with a feed port (201), the diverter outer sleeve (2) is fixedly connected to the adjustment sleeve (3), the external diverter (1) is installed in the inner cavity of the diverter outer sleeve (2), and the external diverter (1) also extends into the inner cavity of the adjustment sleeve (3). The inner cavity of the outer diverter (1) is used for allowing the inner layer material to pass through. The outer diverter (1) is provided with an eccentric section (101). The eccentric section (101) is located in the inner cavity of the diverter outer shell (2). The distance E1 from the top of the eccentric section (101) to the top of the inner cavity of the diverter outer shell (2) is smaller than the distance E2 from the bottom of the eccentric section (101) to the bottom of the inner cavity of the diverter outer shell (2). The length L1 of the top of the eccentric section (101) is larger than the length L2 of the bottom of the eccentric section (101).

2. A double-layer co-extrusion die feeding structure with balanced pressure according to claim 1, characterized in that: The distance E2 from the bottom of the eccentric segment (101) to the bottom of the inner cavity of the diverter jacket (2) is 2-3 times the distance E1 from the top of the eccentric segment (101) to the top of the inner cavity of the diverter jacket (2), and the length L1 of the top of the eccentric segment (101) is 2.5-3.5 times the length L2 of the bottom of the eccentric segment (101).

3. The double-layer co-extrusion die feeding structure with balanced pressure according to claim 1, characterized in that: The external diverter (1) is provided with a guide trough (102) connected to the feed port (201), the guide trough (102) is inclined and coiled on the external diverter (1), the bottom of the guide trough (102) is closer to the adjustment sleeve (3) than the top of the guide trough (102), the depth S2 of the bottom of the guide trough (102) is less than the depth S1 of the top of the guide trough (102), the width B1 of the top of the guide trough (102) is greater than the width B2 of the bottom of the guide trough (102), the top of the guide trough (102) is connected to the feed port (201), and the width B1 of the top of the guide trough (102) is the same as the width of the feed port (201).

4. A double-layer co-extrusion die feeding structure with balanced pressure according to claim 3, characterized in that: The depth S1 of the top of the guide trough (102) is 1-2 times the depth S2 of the bottom of the guide trough (102); the width B1 of the top of the guide trough (102) is 1.5-3 times the width B2 of the bottom of the guide trough (102).

5. The double-layer co-extrusion die feeding structure with balanced pressure according to claim 3, characterized in that: A side wall of the guide trough (102) close to one end of the eccentric section (101) is provided with a rounded corner connected to the eccentric section (101), and the rounded corner radius of the top of the guide trough (102) is larger than the rounded corner radius of the bottom of the guide trough (102).

6. A double-layer co-extrusion die feeding structure with balanced pressure according to claim 3, characterized in that: The external diverter (1) is further provided with a pressure equalizing groove (103) for equalizing the material pressure. The pressure equalizing groove (103) and the material guide groove (102) are respectively located on both sides of the eccentric section (101).

7. A double-layer co-extrusion die feeding structure with balanced pressure according to claim 6, characterized in that: An outer adjustment ring (4) is installed on a side of the inner cavity of the adjustment sleeve (3) close to the outer diverter (1), and the outer adjustment ring (4) is located in the installation groove on the adjustment sleeve (3). One end of the outer adjustment ring (4) close to the diverter outer sleeve (2) is aligned with the pressure equalizing groove (103). The adjustment sleeve (3) is provided with an adjustment bolt (301) that can change the position of the outer adjustment ring (4) in the installation groove. The adjustment bolt (301) is threadedly connected to the adjustment sleeve (3), and the bottom of the adjustment bolt (301) extends into the installation groove and abuts against the outer side wall of the outer adjustment ring (4).

8. The double-layer co-extrusion die feeding structure with balanced pressure according to claim 3, characterized in that: The axis of the feed port (201) is parallel to the inclination direction of the guide trough (102).

9. A double-layer co-extrusion die feeding structure with balanced pressure according to claim 8, characterized in that: It also includes an outer layer joint (5) that can be connected to an outer layer injection molding machine, the outer layer joint (5) is installed on the diverter jacket (2), and the outer layer joint (5) is provided with a material guide hole (501) that can be connected to the outer layer injection molding machine, the axis of the material guide hole (501) is parallel to the vertical direction, the bottom of the material guide hole (501) is connected to the feed port (201), and a conical gasket (6) is provided between the material guide hole (501) and the feed port (201), the inner side wall of the top of the conical gasket (6) is aligned with the material guide hole (501), and the inner side wall of the bottom of the conical gasket (6) is aligned with the feed port (201).

10. A pressure-balanced double-layer co-extrusion die, characterized in that: The invention comprises a feeding structure, an inner and outer layer diverter bracket (7), a confluence core (8), a compression plate (9), a fixed core seat (10), a die (12), a die core (13) and a conical diverter (14), wherein the feeding structure is a double-layer co-extrusion die feeding structure with balanced pressure as described in any one of claims 1 to 9, the inner and outer layer diverter bracket (7) is provided with an outer flow channel gap for allowing the outer layer material to pass through, the adjustment sleeve (3), the inner and outer layer diverter bracket (7), the compression plate (9) and the die (12) are fixedly connected in sequence, wherein the die (12) is fixedly connected to the inner and outer layer diverter bracket (7), the compression plate (9) and the die (12) by a clamping flange (1 1) is installed on the compression plate (9); the converging core (8) is installed on the inner and outer layer diverter bracket (7) and extends into the inner cavity of the compression plate (9); the conical diverter (14), the fixed core seat (10) and the core (13) are connected in sequence, the conical diverter (14) is installed on the inner and outer layer diverter bracket (7) and its conical section extends into the inner cavity of the outer diverter (1), the fixed core seat (10) is located in the inner cavity of the converging core (8), and the core (13) is installed on the fixed core seat (10) and extends into the inner cavity of the die (12); The outer flow channel (15) includes the gap between the outer diverter (1) and the diverter jacket (2), the outer flow channel gap, and the gap between the converging core (8) and the compression plate (9); the inner flow channel (16) includes the inner cavity of the outer diverter (1), the gap between the outer diverter (1) and the conical diverter (14), the gap between the conical diverter (14) and the inner and outer diverter brackets (7), and the gap between the fixed core seat (10) and the converging core (8); the main flow channel (17) includes the gap between the die (12) and the die core (13); the outer flow channel (15) and the inner flow channel (16) merge at the entrance of the main flow channel (17).

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