Extrusion molding die for ppr pipe

Abstract

The utility model relates to an extrusion molding die for a ppr pipe, which comprises a cylindrical outer die holder, a cylindrical flow guide cavity is formed on the front end surface of the outer die holder, a conical liquid inlet cavity penetrating through the rear end surface of the outer die holder is formed on the bottom surface of the flow guide cavity, and a ceramic support disc is inserted into the flow guide cavity of the outer die holder. The rear end face of the outer ring of the supporting disc abuts against the bottom face of the flow guide cavity, the front end face of the outer ring of the supporting disc abuts against a flow guide sleeve with the conical inner wall, the front end face of the flow guide sleeve abuts against a cylindrical annular extrusion die, a check ring is formed on the outer wall of the rear end of the extrusion die, and an outer cooling sleeve is inserted in the portion, on the front side of the check ring, of the extrusion die. An annular positioning boss is formed on the rear end face of the outer cooling sleeve, and the positioning boss is inserted into the flow guide cavity of the outer die base and abuts against the front end of the check ring in a pressing mode. The extrusion molding die is simple and compact in structure, is provided with an inner cooling structure and an outer cooling structure, and can realize uniform cooling during molding of the ppr pipe, so that the smoothness of the inner pipe wall and the outer pipe wall of the ppr pipe can be improved.

Description

Technical field:

[0001] The utility model relates to the technical field of plastic pipe forming machines, and more specifically to an extrusion forming die for PPR pipes. Background technology:

[0002] Tripropylene (PP) pipe, also known as PP-R pipe, random copolymer polypropylene pipe, or PPR pipe, is a pipe made from random copolymer polypropylene. Compared to traditional pipes like cast iron, galvanized steel, and cement pipe, PPR pipe offers advantages such as energy and material conservation, environmental friendliness, lightweight and high strength, corrosion resistance, a smooth, scale-free interior, ease of construction and maintenance, and a long service life. It is widely used in construction, municipal administration, industry, and agriculture, including building water supply and drainage, urban and rural water supply and drainage, city gas, electricity, fiber optic cable sheathing, industrial fluid transportation, and agricultural irrigation. At present, ppr pipes are generally made by extrusion molding by a molding machine. The molding machine is provided with an extrusion molding die. The die generally adopts multiple cooling pipes to cool the outer layer of the ppr melt in the die, and then gradually cools it to the inner layer of the ppr melt. After the ppr melt is cooled, it is formed into a ppr pipe and extruded from the die under the push of the subsequent ppr melt. However, this cooling method is that the ppr pipe is gradually cooled from the outside to the inside, and the cooling is uneven, resulting in the inner wall of the ppr pipe not being smooth. Therefore, the die needs to be optimized to improve the smoothness of the inner wall of the pipe by uniformly cooling the ppr melt. Utility model content:

[0003] The purpose of the utility model is to address the deficiencies of the existing technology and provide an extrusion molding die for a PPR pipe. The extrusion molding die has a simple and compact structure and is provided with internal and external cooling structures, which can achieve uniform cooling during the molding of the PPR pipe, thereby improving the smoothness of the inner and outer pipe walls of the PPR pipe.

[0004] The cam is provided with a cylindrical outer mold base, the front end surface of the outer mold base is provided with a cylindrical flow guide cavity, the bottom surface of the flow guide cavity is provided with a conical liquid inlet cavity which passes through the rear end surface of the outer mold base, a ceramic support plate is inserted in the flow guide cavity of the outer mold base, a plurality of through holes connecting the liquid inlet cavity and the flow guide cavity are formed on the ceramic support plate, the rear end surface of the outer ring of the support plate abuts against the bottom surface of the flow guide cavity, the front end surface abuts against a flow guide sleeve with a conical inner wall, the front end surface of the flow guide sleeve abuts against a cylindrical annular extrusion die, a retaining ring is formed on the outer wall of the rear end of the extrusion die, an outer cooling sleeve is inserted on the extrusion die on the front side of the retaining ring, an annular positioning boss is formed on the rear end surface of the outer cooling sleeve, the positioning boss is inserted in the flow guide cavity of the outer mold base and pressed against the front end of the retaining ring; a flange is formed on the outer wall of the rear end of the outer cooling sleeve, a plurality of fastening bolts are inserted on the flange, and the fastening bolts are screwed on the front end surface of the outer mold base;

[0005] The inner wall of the outer cooling sleeve is pressed against the outer wall of the extrusion die to form a spiral outer cooling channel, and the upper and lower ends of the front end surface of the outer cooling sleeve are respectively formed with a cooling outlet hole and a cooling inlet hole connected to the external cooling channel; a plurality of positioning bolts are screwed on the outer wall of the front end of the outer die base, and the ends of the positioning bolts are pressed against the outer wall of the retaining ring;

[0006] A cylindrical annular core mold is inserted into the extrusion die, and an annular molding cavity is formed between the core mold and the extrusion die. The rear end of the core mold is inserted into the guide sleeve and formed with an internal threaded connecting sleeve. The rear end of the internal threaded connecting sleeve is pressed against the ceramic support disk. A conical guide head is inserted into the liquid inlet cavity on the rear side of the ceramic support disk. The front end surface of the guide head is against the ceramic support disk and is formed with an external threaded joint. The external threaded joint passes through the ceramic support disk and is screwed and fixed in the internal threaded connecting sleeve.

[0007] An inner cooling interface is formed on the outer wall of one side of the outer mold base, and an insulating guide tube is fixed in the inner cooling interface. The insulating guide tube passes through the ceramic support plate and is inserted into the external threaded joint. A cooling channel connecting the inner hole of the core mold and the insulating guide tube is formed in the center of the external threaded joint.

[0008] Preferably, the central axis of the outer mold base, the central axis of the ceramic support plate, the central axis of the guide sleeve, the central axis of the extrusion mold, the central axis of the outer cooling sleeve, the central axis of the core mold and the central axis of the guide head are all on the same straight line.

[0009] Preferably, at least three of the fastening bolts and positioning bolts are provided, and the fastening bolts and positioning bolts are evenly distributed in a ring shape around the central axis of the extrusion die, and the fastening bolts are distributed between the positioning bolts.

[0010] Preferably, the ceramic support plate is provided with at least five through holes, which are evenly distributed in a ring shape around the central axis of the ceramic support plate; and the thermal insulation flow guide pipe is provided between adjacent through holes.

[0011] Preferably, the inner wall diameter of the front end of the guide sleeve is smaller than the inner wall diameter of the rear end, and the inner wall diameter of the front end of the guide sleeve is equal to the inner aperture of the extrusion die;

[0012] The diameter of the outer wall of the positioning boss on the outer cooling sleeve, the diameter of the outer wall of the guide sleeve and the inner aperture of the guide cavity on the outer mold base are consistent.

[0013] Preferably, a concave platform communicating with the guide cavity is formed on the rear end surface of the outer mold base, and a filter plate is inserted and fixed in the concave platform.

[0014] Preferably, a high-temperature resistant sealing gasket is clamped between the end of the thermal insulation guide tube and the external threaded joint.

[0015] Preferably, the cooling outlet hole on the outer cooling sleeve is connected to the rear end of the outer cooling channel, and the cooling inlet hole is connected to the front end of the outer cooling channel.

[0016] The beneficial effects of the present invention are:

[0017] The extrusion die has a simple and compact structure and is provided with internal and external cooling structures, which can achieve uniform cooling during the forming of the PPR pipe, thereby improving the smoothness of the inner and outer pipe walls of the PPR pipe. Description of the drawings:

[0018] Figure 1 This is a schematic structural diagram of the utility model;

[0019] Figure 2 It is a schematic diagram of the half-section structure of the utility model from the side.

[0020] In the figure: 1. Outer mold base; 11. Liquid inlet cavity; 12. Guide cavity; 13. Concave platform; 14. Internal cooling interface; 2. Support plate; 21. Through hole; 3. Guide sleeve; 4. Guide sleeve; 5. Core mold; 51. Internal threaded connecting sleeve; 6. Guide head; 61. External threaded joint; 7. External cooling sleeve; 71. Positioning boss; 72. Flange; 73. External cooling channel; 74. Cooling inlet hole; 75. Cooling outlet hole; 8. Thermal insulation guide tube; 9. High temperature resistant sealing gasket; 10. Filter plate; 20. Positioning bolt; 30. Fastening bolt. Specific implementation method:

[0021] Example: See Figure 1 、 2 As shown, a PPR pipe extrusion molding die comprises a cylindrical outer die base 1, a cylindrical guide cavity 12 is formed on the front end surface of the outer die base 1, a conical liquid inlet cavity 11 is formed on the bottom surface of the guide cavity 12 and passes through the rear end surface of the outer die base 1, a ceramic support plate 2 is inserted into the guide cavity 12 of the outer die base 1, and a plurality of through holes 21 are formed on the ceramic support plate 2 to connect the liquid inlet cavity 11 and the guide cavity 12, the rear end surface of the outer ring of the support plate 2 abuts against the bottom surface of the guide cavity 12, the front end surface abuts against a guide sleeve 3 with a conical inner wall, the front end surface of the guide sleeve 3 abuts against a cylindrical ring-shaped extrusion die 4, and the rear end of the extrusion die 4 A retaining ring 41 is formed on the outer wall of the outer cooling sleeve 7, and an outer cooling sleeve 7 is inserted on the extrusion die 4 on the front side of the retaining ring 41. An annular positioning boss 71 is formed on the rear end surface of the outer cooling sleeve 7. The positioning boss 71 is inserted into the guide cavity 12 of the outer die base 1 and pressed against the front end of the retaining ring 41; a flange 72 is formed on the outer wall of the rear end of the outer cooling sleeve 7, and a plurality of fastening bolts 30 are inserted on the flange 72. The fastening bolts 30 are screwed on the front end surface of the outer die base 1; the fastening bolts 30 can assemble and fix the above-mentioned parts together, with a compact structure and convenient installation and disassembly, which is convenient for cleaning and dredging when the extrusion molding die is blocked;

[0022] The inner wall of the outer cooling sleeve 7 is against the outer wall of the extrusion die 4 to form a spiral outer cooling channel 73, and the upper and lower ends of the front end surface of the outer cooling sleeve 7 are respectively formed with a cooling outlet hole 75 and a cooling inlet hole 74 connected to the outer cooling channel 73; a plurality of positioning bolts 20 are screwed on the outer wall of the front end of the outer die base 1, and the ends of the positioning bolts 20 are against the outer wall of the retaining ring 41. Due to processing errors, the position of the extrusion die 4 can be adjusted by the positioning bolts 20 to ensure that the extrusion die 4 and the core die 5 are concentric;

[0023] A cylindrical annular core mold 5 is inserted into the extrusion die 4, and an annular molding cavity a is formed between the core mold 5 and the extrusion die 4. The rear end of the core mold 5 is inserted into the guide sleeve 3 and formed with an internal threaded connecting sleeve 51. The rear end of the internal threaded connecting sleeve 51 is pressed against the ceramic support disk 2. A conical guide head 6 is inserted into the liquid inlet cavity 11 on the rear side of the ceramic support disk 2. The front end surface of the guide head 6 is against the ceramic support disk 2 and is formed with an external threaded joint 61. The external threaded joint 61 passes through the ceramic support disk 2 and is screwed and fixed in the internal threaded connecting sleeve 51.

[0024] An inner cooling interface 14 is formed on the outer wall of one side of the outer mold base 1, and an insulating guide tube 8 is inserted and fixed in the inner cooling interface 14. The insulating guide tube 8 passes through the ceramic support plate 2 and is inserted into the external threaded joint 61. A cooling channel 62 connecting the inner hole of the core mold 5 and the insulating guide tube 8 is formed in the center of the external threaded joint 61.

[0025] The central axis of the outer mold base 1, the central axis of the ceramic support plate 2, the central axis of the guide sleeve 3, the central axis of the extrusion mold 4, the central axis of the outer cooling sleeve 7, the central axis of the core mold 5 and the central axis of the guide head 6 are all on the same straight line.

[0026] There are at least three fastening bolts 30 and positioning bolts 20, which are evenly distributed in a circular shape around the central axis of the extrusion die 4. The fastening bolts 30 are distributed between the positioning bolts 20, so that there will be no interference with the mounting holes on the outer die base 1.

[0027] There are at least five through holes 21 on the ceramic support plate 2, and the through holes 21 are evenly distributed in a ring shape around the central axis of the ceramic support plate 2; the thermal insulation guide tube 8 is arranged between adjacent through holes 21 to prevent the cooling water in the thermal insulation guide tube 8 from affecting the PPR melt entering the outer mold base 1.

[0028] The inner wall diameter of the front end of the guide sleeve 3 is smaller than the inner wall diameter of the rear end, and the inner wall diameter of the front end of the guide sleeve 3 is equal to the inner aperture of the extrusion die 4;

[0029] The diameter of the outer wall of the positioning boss 71 on the outer cooling sleeve 7 , the diameter of the outer wall of the flow guide sleeve 3 and the inner diameter of the flow guide cavity 12 on the outer mold base 1 are consistent.

[0030] A concave platform 13 communicating with the guide cavity 12 is formed on the rear end surface of the outer mold base 1, and a filter plate 10 is inserted and fixed in the concave platform 13. The filter plate 10 can filter impurities in the PPR melt entering the outer mold base 1 and buffer the PPR melt.

[0031] A high temperature resistant sealing gasket 9 is clamped between the end of the heat-insulating flow guide pipe 8 and the external threaded joint 61 , and the high temperature resistant sealing gasket 9 can be a glass fiber sealing ring.

[0032] The cooling outlet hole 75 on the outer cooling sleeve 7 is connected to the rear end of the outer cooling channel 73, and the cooling inlet hole 74 is connected to the front end of the outer cooling channel 73. Both the cooling outlet hole 75 and the cooling inlet hole 74 can be installed with elbow quick pipe joints; thus, the cooling temperature at the front end of the extrusion die 4 is lower than the cooling temperature at the rear end, which is more conducive to uniform cooling and molding of the PPR pipe.

[0033] Working principle: This structure is an extrusion molding die for ppr pipes. The technical point of the extrusion molding die is that the structure is simple and compact. It has few components, but has an external cooling channel composed of an external cooling sleeve 7 and an extrusion die 4, and an internal cooling channel composed of an insulating guide tube 8, a cooling channel 62 and a core die 5. Cooling water flows through the internal cooling channel and the external cooling channel respectively, which can uniformly cool the ppr melt in the molding cavity a.

[0034] The embodiments are intended to illustrate the present invention and are not intended to limit the present invention. Any person skilled in the art may modify the embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be as set forth in the claims of the present invention.

Claims

1. A PPR pipe extrusion die, comprising a cylindrical outer die base (1), a cylindrical flow guide cavity (12) formed on the front end surface of the outer die base (1), a conical liquid inlet cavity (11) formed on the bottom surface of the flow guide cavity (12) and penetrating the rear end surface of the outer die base (1), characterized in that: A ceramic support plate (2) is inserted into the flow guide cavity (12) of the outer die seat (1), and a plurality of through holes (21) are formed on the ceramic support plate (2) to connect the liquid inlet cavity (11) and the flow guide cavity (12). The rear end face of the outer ring of the support plate (2) abuts against the bottom surface of the flow guide cavity (12), and the front end face abuts against a flow guide sleeve (3) with a conical inner wall. The front end face of the flow guide sleeve (3) abuts against a cylindrical ring-shaped extrusion die (4), and a retaining ring (41) is formed on the outer wall of the rear end of the extrusion die (4). (41) An outer cooling sleeve (7) is inserted on the extrusion die (4) on the front side, and a circular positioning boss (71) is formed on the rear end face of the outer cooling sleeve (7), and the positioning boss (71) is inserted into the guide cavity (12) of the outer die base (1) and pressed against the front end of the retaining ring (41); a flange (72) is formed on the outer wall of the rear end of the outer cooling sleeve (7), and a plurality of fastening bolts (30) are inserted on the flange (72), and the fastening bolts (30) are screwed on the front end face of the outer die base (1); The inner wall of the outer cooling sleeve (7) is pressed against the outer wall of the extrusion die (4) to form a spiral outer cooling channel (73), and the upper and lower ends of the front end surface of the outer cooling sleeve (7) are respectively formed with a cooling outlet hole (75) and a cooling inlet hole (74) connected to the outer cooling channel (73); a plurality of positioning bolts (20) are screwed on the outer wall of the front end of the outer die base (1), and the ends of the positioning bolts (20) are pressed against the outer wall of the retaining ring (41); A cylindrical annular core mold (5) is inserted into the extrusion mold (4), and an annular molding cavity (a) is formed between the core mold (5) and the extrusion mold (4). The rear end of the core mold (5) is inserted into the guide sleeve (3) and formed with an internal thread connection sleeve (51). The rear end of the internal thread connection sleeve (51) is pressed against the ceramic support disk (2). A conical guide head (6) is inserted into the liquid inlet cavity (11) on the rear side of the ceramic support disk (2). The front end surface of the guide head (6) is pressed against the ceramic support disk (2) and is formed with an external thread joint (61). The external thread joint (61) passes through the ceramic support disk (2) and is screwed and fixed in the internal thread connection sleeve (51). An inner cooling interface (14) is formed on the outer wall of one side of the outer mold base (1), a heat-insulating flow guide tube (8) is inserted and fixed in the inner cooling interface (14), the heat-insulating flow guide tube (8) passes through the ceramic support plate (2) and is inserted into the external threaded joint (61), and a cooling channel (62) is formed in the center of the external threaded joint (61) for connecting the inner hole of the core mold (5) and the heat-insulating flow guide tube (8).

2. The extrusion die for a PPR pipe according to claim 1, characterized in that: The central axis of the outer die base (1), the central axis of the ceramic support plate (2), the central axis of the flow guide sleeve (3), the central axis of the extrusion die (4), the central axis of the outer cooling sleeve (7), the central axis of the core die (5) and the central axis of the flow guide head (6) are all on the same straight line.

3. The extrusion die for a PPR pipe according to claim 2, characterized in that: There are at least three fastening bolts (30) and positioning bolts (20), and the fastening bolts (30) and positioning bolts (20) are evenly distributed in a circular shape around the central axis of the extrusion die (4), and the fastening bolts (30) are distributed between the positioning bolts (20).

4. The extrusion die for a PPR pipe according to claim 2, characterized in that: There are at least five through holes (21) on the ceramic support plate (2), and the through holes (21) are evenly distributed in a ring shape around the central axis of the ceramic support plate (2); the heat-insulating flow guide tube (8) is arranged between adjacent through holes (21).

5. The extrusion die for a PPR pipe according to claim 2, characterized in that: The inner wall diameter of the front end of the guide sleeve (3) is smaller than the inner wall diameter of the rear end, and the inner wall diameter of the front end of the guide sleeve (3) is equal to the inner aperture of the extrusion die (4); The diameter of the outer wall of the positioning boss (71) on the outer cooling sleeve (7), the diameter of the outer wall of the guide sleeve (3) and the inner diameter of the guide cavity (12) on the outer mold base (1) are consistent.

6. The extrusion die for a PPR pipe according to claim 2, characterized in that: A concave platform (13) communicating with the flow guide cavity (12) is formed on the rear end surface of the outer mold base (1), and a filter plate (10) is inserted and fixed in the concave platform (13).

7. The extrusion die for a PPR pipe according to claim 2, characterized in that: A high-temperature resistant sealing gasket (9) is clamped between the end of the heat-insulating flow-guiding pipe (8) and the external threaded joint (61).

8. The extrusion die for a PPR pipe according to claim 2, characterized in that: The cooling outlet hole (75) on the outer cooling sleeve (7) is connected to the rear end of the outer cooling channel (73), and the cooling inlet hole (74) is connected to the front end of the outer cooling channel (73).

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