Extrusion die for double-pipe discharging

Abstract

The extrusion die comprises an upper die, a lower die and a die holder, a first mounting groove is formed in the center of the rear end face of the upper die, a die core is detachably connected into the first mounting groove, and a plurality of flow dividing holes are formed in the upper die; the mold core comprises a fixed disc fixedly nested in the first mounting groove, two flow guide columns are arranged on the fixed disc in the axial direction of the fixed disc, and each flow guide column is of a hyperbola cylinder structure; a welding chamber is arranged on the front end face of the lower die, second mounting grooves are formed in the positions, corresponding to the flow guide columns, in the welding chamber, and sizing rings are detachably connected into the second mounting grooves. A flow guide fillet is arranged at the front side end of the inner wall of the sizing ring, and a receding flaring is formed in the rear side end of the inner wall of the sizing ring. A profile outlet is formed in the rear end face of the lower die, and the head of the flow guide column extends into the sizing ring; the die has the advantages that extruded pipes are good in forming, produced pipes are high in quality, the die core can be independently detached, maintained and replaced, and the maintenance cost and the production cost of the die are reduced.

Description

Technical Field

[0001] This utility model relates to the field of pipe extrusion die technology, specifically a double-pipe extrusion die. Background Technology

[0002] Hot extrusion is the earliest extrusion forming technology among several extrusion processes. Currently, the extrusion dies used for producing pipes in China are basically single-extrusion dies. In order to improve production efficiency, a dual-extrusion dies are now being used. Patent publication number CN201271658Y discloses a hot extrusion die for aluminum alloy pipes with multiple exits. Specifically, the upper die has multiple die cores, and the lower die has multiple profile outlets that are adapted to the die cores. The billet in the welding chamber passes through the multiple die cores on the upper die and the multiple profile outlets on the lower die, realizing the processing of pipes with multiple exits. The working conditions of the extrusion die are harsh. During extrusion, the billet is in a near-closed state, so the die cores need to withstand very high pressure. This leads to the die cores being frequently damaged due to excessive force during the aluminum pipe extrusion process. Since the die cores and the upper die are an integral structure, the die cores cannot be disassembled and replaced separately, resulting in high die maintenance costs, poor pipe extrusion forming, and poor quality of extruded pipes. Utility Model Content

[0003] The technical problem this invention aims to solve is to overcome existing defects and provide a dual-tube extrusion die. The billet in the welding chamber flows smoothly along the guide column and sizing ring, resulting in well-formed and high-quality extruded pipes. The die core and sizing ring can be disassembled and replaced separately, reducing die maintenance costs. Different pipe shapes can be produced by replacing the die core and sizing ring, offering flexibility and convenience with low maintenance and replacement costs. The die base structure is simple and rationally designed. It reduces the use of liquid nitrogen, lowering production costs. This invention effectively solves the problems in the background technology.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a dual-tube discharge extrusion die, comprising an upper die, a lower die, and a die base that are sequentially and tightly fitted together. An installation groove is formed at the center of the rear end face of the upper die, and a die core is detachably connected within the installation groove. Multiple flow-diverting holes are formed around the circumference of the upper die located within the installation groove. The die core includes a fixed disk nested within the installation groove, and two guide columns are provided along its axial direction on the fixed disk. The guide columns are hyperbolic cylindrical structures, and the ends of the guide columns... The outer diameter of the mold is larger than the outer diameter of its head; the front end face of the lower mold is provided with a welding chamber, and each of the welding chambers is provided with a second mounting groove at the position of the corresponding guide column. A sizing ring is detachably connected in the second mounting groove; the sizing ring is a hollow stepped shaft structure, and the front end of the inner wall of the sizing ring is provided with a guide fillet, and the rear end of the inner wall of the sizing ring is provided with a relief flare; the rear end face of the lower mold is provided with a profile outlet at the position of the corresponding sizing ring, the profile outlet is connected to the welding chamber, and the head of the guide column extends into the sizing ring.

[0005] Furthermore, the end of the guide column is provided with a connecting root that matches its end face, and the connecting root is a cylindrical structure; the outer circumference of the fixed plate is provided with connecting holes at equal intervals, and bolt holes are provided in the mounting groove at the positions corresponding to the connecting holes. The mold core is fixedly connected to the upper mold by connecting bolts passing through the connecting holes and bolt holes.

[0006] Furthermore, a second connecting hole is provided on the shoulder of the sizing ring, and a second bolt hole is provided in the mounting groove at the position corresponding to the second connecting hole. The sizing ring is fixedly connected to the lower mold by connecting bolts passing through the second connecting hole and the second bolt hole.

[0007] Furthermore, the front end face of the mold base is provided with a cooling ring groove, which includes an outer ring groove and an inner ring groove coaxially formed on the front end face of the mold base, and a connecting groove is formed between the outer ring groove and the inner ring groove to enable them to communicate with each other; a liquid nitrogen inlet hole is formed on the outer circumferential wall of the mold base along its radial direction, and a liquid nitrogen outlet hole connected to the liquid nitrogen inlet hole is formed on the outer ring groove along its axial direction; a thinning surface is provided on the inner side of the front end face of the mold base in the inner ring groove, and a nitrogen purging cavity is formed between the thinning surface and the lower mold; a discharge hole is formed on the mold base at the position of the corresponding profile outlet.

[0008] Furthermore, the front end face of the mold base is provided with a sealing ring groove around the cooling ring groove, and the lower mold is provided with a sealing convex ring adapted to its structure at the position corresponding to the sealing ring groove. The sealing convex ring is a conical ring platform structure, the sealing ring groove is a conical ring groove structure, and a metal sealing ring is also provided in the sealing ring groove.

[0009] Furthermore, the liquid nitrogen inlet is connected to an adjustable liquid nitrogen flow electromagnetic switch valve, and a thermocouple for detecting the surface temperature of the lower mold is provided on the outer wall of the lower mold.

[0010] Furthermore, the upper mold, lower mold, and mold base are tightly fitted together by connecting bolts; the rear end face of the upper mold is provided with multiple positioning shafts, and the front end face of the lower mold is provided with positioning holes that are adapted to the positioning shafts.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: In this dual-tube extrusion die, the billet in the welding chamber flows along the guide column and sizing ring towards the profile outlet. The guide column has a hyperbolic cylindrical structure and is equipped with rounded corners, which facilitates the smooth flow of the billet in the welding chamber, resulting in well-formed and high-quality extruded pipes. The cooling ring groove on the front face of the die base cools the lower die and the pipe, and provides a protective atmosphere for the extruded pipe. The die base has a simple structure and a reasonable design. The temperature of the lower die is detected by a thermocouple, and the electromagnetic switch valve is adjusted to regulate the liquid nitrogen flow rate, thereby reducing the amount of liquid nitrogen used and lowering production costs. The die core and sizing ring can be disassembled, repaired, and replaced separately. Different pipe shapes can be produced by replacing the die core and sizing ring, making it flexible and convenient to use, with low maintenance and replacement costs. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 This is a side view of the upper mold of this utility model;

[0014] Figure 3 This is a side view of the upper mold with the mold core installed in this utility model;

[0015] Figure 4 This is a schematic diagram of the mold core structure of this utility model;

[0016] Figure 5 This is a schematic diagram of the lower mold structure of this utility model;

[0017] Figure 6 This is a schematic diagram of the sizing ring structure of this utility model;

[0018] Figure 7 This is a schematic diagram of the mold base structure of this utility model;

[0019] Figure 8 This is a side view of the mold base of this utility model;

[0020] Figure 9 for Figure 1 Enlarged view of a specific area.

[0021] In the diagram: 1. Upper mold; 11. Diverter hole; 12. Mounting groove one; 13. Bolt hole one; 14. Positioning shaft; 2. Lower mold; 21. Welding chamber; 22. Profile outlet; 23. Mounting groove two; 24. Sealing ring; 25. Positioning hole; 3. Mold core; 31. Fixing plate; 32. Guide column; 321. Connecting root; 33. Connecting hole one; 4. Sizing ring; 41. Guide radius; 42. Relief flare; 43. Connecting hole two; 5. Mold base; 51. Liquid nitrogen inlet hole; 52. Liquid nitrogen outlet hole; 53. Cooling ring groove; 531. Outer ring groove; 532. Inner ring groove; 533. Connecting groove; 54. Thinning surface; 55. Discharge hole; 56. Sealing ring groove; 6. Electromagnetic switch valve; 7. Thermocouple; 8. Metal sealing ring. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0023] Please see Figure 1-9 This utility model provides a technical solution: a double-tube extrusion die, including an upper die 1, a lower die 2 and a die base 5 that are tightly fitted together in sequence. An installation groove 12 is provided at the center of the rear end face of the upper die 1. A die core 3 is detachably connected in the installation groove 12. Multiple diversion holes 11 are provided on the outer periphery of the installation groove 12 of the upper die 1.

[0024] The mold core 3 includes a fixed disk 31 fixedly nested in the mounting groove 12. The fixed disk 31 has two guide columns 32 along its axial direction. The guide columns 32 are hyperbolic cylindrical structures, and the outer diameter of the end of the guide column 32 is larger than the outer diameter of its head. The fixed disk 31 has connecting holes 33 at equal intervals on its outer circumference. The mounting groove 12 has bolt holes 13 at the positions corresponding to the connecting holes 33. The mold core 3 is fixedly connected to the upper mold 1 by connecting bolts passing through the connecting holes 33 and the bolt holes 13.

[0025] The lower mold 2 has a welding chamber 21 on its front end face. Each welding chamber 21 has a mounting groove 23 at a position corresponding to the guide column 32. A sizing ring 4 is detachably connected within the mounting groove 23. The sizing ring 4 is a hollow stepped shaft structure, with a guide radius 41 at the front end of its inner wall and a relief flare 42 at the rear end. A connecting hole 43 is provided on the shoulder of the sizing ring 4. A bolt hole 2 is provided in the mounting groove 23 at a position corresponding to the connecting hole 43. The sizing ring 4 is fixedly connected to the lower mold 2 via connecting bolts passing through the connecting hole 43 and the bolt hole 2.

[0026] The rear end face of the lower mold 2 is provided with a profile outlet 22 at the position corresponding to the sizing ring 4. The profile outlet 22 is connected to the welding chamber 21, and the head of the guide column 32 extends into the sizing ring 4.

[0027] The front end face of the mold base 5 is provided with a cooling ring groove 53, which includes an outer ring groove 531 and an inner ring groove 532 coaxially formed on the front end face of the mold base 5, and a connecting groove 533 is formed between the outer ring groove 531 and the inner ring groove 532 to connect them. A liquid nitrogen inlet hole 51 is formed on the outer circumferential wall of the mold base 5 in the radial direction, and a liquid nitrogen outlet hole 52 connected to the liquid nitrogen inlet hole 51 is formed on the outer ring groove 531 in the axial direction. A thinning surface 54 is provided on the inner side of the inner ring groove 532 on the front end face of the mold base 5, and a nitrogen purging cavity is formed between the thinning surface 54 and the lower mold 2. A discharge hole 55 is formed on the mold base 5 at the position of the corresponding profile outlet 22. An electromagnetic switch valve 6 that can adjust the liquid nitrogen flow rate is connected to the inlet of the liquid nitrogen inlet hole 51, and a thermocouple 7 for detecting the surface temperature of the lower mold 2 is provided on the outer wall of the lower mold 2.

[0028] Working principle:

[0029] The extrusion die is fixed on the extruder. An external liquid nitrogen supply device is connected to the electromagnetic switch valve 6. The extruder heats and extrudes the billet. The billet is extruded through the diversion hole 11 on the upper die 1 into the welding chamber 21 of the lower die 2. The billet in the welding chamber 21 flows towards the profile outlet 22 along the guide column 32 and the guide radius 41. The guide column 32 has a hyperbolic cylindrical structure and is matched with the guide radius 41 to facilitate the smooth flow of the billet in the welding chamber 21. After passing through the forming cavity formed between the inner wall of the sizing ring 4 and the guide column 32, the billet is extruded from the profile outlet 22. At the same time, the electric valve is turned on. The magnetic switch valve 6 supplies liquid nitrogen to the liquid nitrogen inlet 51 through the liquid nitrogen outlet 52 and flows into the outer ring groove 531 of the cooling ring groove 53. The liquid nitrogen in the outer ring groove 531 cools the lower mold 2 and converts it into nitrogen gas. The nitrogen gas in the outer ring groove 531 flows into the inner ring groove 532 through the connecting groove 533. The nitrogen gas in the inner ring groove 532 flows into the nitrogen purging cavity to form a protective atmosphere, which purifies and cools the pipe. The temperature of the lower mold 2 is detected by the thermocouple 7, and the electromagnetic switch valve 6 is adjusted to adjust the liquid nitrogen flow rate, reduce the amount of liquid nitrogen used, and reduce production costs.

[0030] When the mold core 3 is damaged, it can be removed by unscrewing the connecting bolts on the fixing plate 31. The mold core 3 can be disassembled, repaired and replaced separately. When the sizing ring 4 is damaged, it can be removed by unscrewing the connecting bolts. The sizing ring 4 can be disassembled, repaired and replaced separately. Different pipe shapes can be produced by replacing the mold core 3 and the sizing ring 4. It is flexible and convenient to use, and the maintenance and replacement costs are low.

[0031] Furthermore, the end of the guide column 32 is provided with a connecting root 321 that is adapted to its end face. The connecting root 321 is a cylindrical structure. The structural strength between the guide column 32 and the fixed disk 31 is improved by the connecting root 321.

[0032] Furthermore, the front end face of the mold base 5 is provided with a sealing ring groove 56 around the cooling ring groove 53. The lower mold 2 is provided with a sealing convex ring 24 adapted to the structure of the sealing ring groove 56 at the position corresponding to the sealing ring groove 56. The sealing convex ring 24 is a conical ring structure, the sealing ring groove 56 is a conical ring groove structure, and a metal sealing ring 8 is also provided in the sealing ring groove 56. Through the cooperation between the sealing ring groove 56 and the sealing convex ring 24 and the metal sealing ring 8 provided in the sealing ring groove 56, the leakage of nitrogen in the cooling ring groove 53 can be prevented, further reducing the amount of liquid nitrogen used and reducing production costs.

[0033] Furthermore, the upper mold 1, the lower mold 2, and the mold base 5 are tightly fitted together by connecting bolts; the rear end face of the upper mold 1 is provided with multiple positioning shafts 14, and the front end face of the lower mold 2 is provided with positioning holes 25 that are adapted to the positioning shafts 14.

[0034] The dual-tube extrusion die disclosed in this embodiment allows the billet in the welding chamber 21 to flow along the guide column 32 and the guide radius 41 towards the profile outlet 22. The guide column 32 is a hyperbolic cylindrical structure, which, together with the guide radius 41, facilitates the smooth flow of the billet in the welding chamber 21, resulting in well-formed and high-quality extruded pipes. The cooling ring groove 53 on the front face of the die base 5 cools the lower die 2 and the pipe, and provides a protective atmosphere for the extruded pipe. The die base 5 has a simple structure and reasonable design. The temperature of the lower die 2 is detected by the thermocouple 7, and the liquid nitrogen flow rate is adjusted by the electromagnetic switch valve 6, thereby reducing the amount of liquid nitrogen used and lowering production costs. The die core 3 and the sizing ring 4 can be disassembled, repaired, and replaced separately. Different pipe shapes can be produced by replacing the die core 3 and the sizing ring 4, making it flexible and convenient to use, with low maintenance and replacement costs.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A twin tube dispensing extrusion die comprising an upper die, a lower die and a die holder which are fitted one after another in close contact, characterized in that: The center of the rear end face of the upper die is provided with a mounting groove one, and a die core is detachably connected in the mounting groove one. A plurality of shunt holes are provided on the outer periphery of the mounting groove one.

2. An extrusion die for twin tube dispensing according to claim 1, wherein: The rear end face of the lower die is provided with a welding chamber, and a mounting groove two is provided in the welding chamber at a position corresponding to the flow guide column. A fixed diameter ring is detachably connected in the mounting groove two. The fixed diameter ring is a hollow stepped shaft structure, and the front side of the inner wall of the fixed diameter ring is provided with a flow guide round corner, and the rear side of the inner wall of the fixed diameter ring is provided with a let-out flared portion. The rear end face of the lower die is provided with a profile outlet at a position corresponding to the fixed diameter ring. The profile outlet is in communication with the welding chamber, and the head of the flow guide column extends into the fixed diameter ring.

3. An extrusion die for twin tube dispensing according to claim 2, wherein: The end of the flow guide column is provided with a connecting root portion matched with the end face of the end. The connecting root portion is a cylindrical structure. The outer periphery of the fixed disc is provided with connecting holes one at equal intervals. The mounting groove one is provided with bolt holes one at positions corresponding to the connecting holes one. The die core is fixedly connected with the upper die through connecting bolts penetrating the connecting holes one and the bolt holes one.

4. An extrusion die for twin tube dispensing according to claim 1, wherein: The shoulder of the fixed diameter ring is provided with connecting holes two. The mounting groove two is provided with bolt holes two at positions corresponding to the connecting holes two. The fixed diameter ring is fixedly connected with the lower die through connecting bolts penetrating the connecting holes two and the bolt holes two.

5. The twin tube dispensing extrusion die of claim 1 wherein: The front end face of the die holder is provided with a cooling ring groove. The cooling ring groove includes an outer ring groove and an inner ring groove two coaxially provided on the front end face of the die holder, and a communication groove is provided between the outer ring groove and the inner ring groove two to communicate with each other. The outer wall of the die holder is provided with a liquid nitrogen inlet hole along the radial direction thereof. The die holder is provided with a liquid nitrogen outlet hole in communication with the liquid nitrogen inlet hole along the axial direction thereof in the outer ring groove.

6. An extrusion die for twin tube dispensing according to claim 4, wherein: The front end face of the die holder is provided with a sealing ring groove in the outer periphery of the cooling ring groove. The lower die is provided with a sealing convex ring matched with the structure thereof at a position corresponding to the sealing ring groove. The sealing convex ring is a conical ring structure, and the sealing ring groove is a conical ring groove structure. A metal sealing ring is further provided in the sealing ring groove.

7. The twin tube dispensing extrusion die of claim 1 wherein: The inlet of the liquid nitrogen inlet hole is connected with an electromagnetic switch valve capable of adjusting the flow of liquid nitrogen. The outer wall of the lower die is provided with a thermocouple for detecting the surface temperature of the lower die. The upper die, the lower die and the die holder are tightly fitted with each other through connecting bolts. The rear end face of the upper die is provided with a plurality of positioning shafts, and the front end face of the lower die is provided with positioning holes matched with the positioning shafts.

Images