Pipe extrusion shaping die

Abstract

The utility model discloses a pipe extrusion shaping die which comprises a mouth die and a core rod, the core rod penetrates through the mouth die, an extrusion channel and a forming channel are formed between the outer wall of the core rod and the inner wall of the mouth die, melt circulates in the extrusion channel and flows to the forming channel from the extrusion channel, a protruding part is arranged on the outer wall of the core rod, and the extrusion channel comprises a compression area. And the lug boss and the inner wall of the mouth mold form a compression area. The utility model provides a pipe extrusion shaping die which reduces screw threads and improves product quality.

Description

TECHNICAL FIELD

[0001] The utility model relates to pipe extrusion shaping equipment technical field more particularly, relate to a kind of pipe extrusion shaping mould. BACKGROUND

[0002] In the production process of pvc pipe, pvc resin is added with other additives, mixed uniformly by a mixer and heated, and then the clinker is added to an extruder. The material is changed from powder state to viscous flow state through the rotation and shearing of the conical twin-screw. Then the material is extruded through the distribution section, transition section, compression section and flat section of the die. Finally, a pvc-u pipe is obtained. The improvement of pvc-u pipe extrusion efficiency is related to many factors such as screw type, motor, die and formula. However, the most direct way is to increase the speed of the screw of the equipment. The increase of the speed of the equipment will increase the shearing and compression of the screw on the material, and the residence time in the die will be reduced. Small wrinkles will appear on the inner wall of the pipe, forming screw marks, which will affect the product quality. SUMMARY

[0003] The utility model aims at overcoming the defects of the prior art, providing a pipe extrusion shaping die, reducing screw marks and improving product quality.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a pipe extrusion shaping die, comprising a die head and a mandrel, the mandrel passes through the die head, and an extrusion channel and a forming channel are formed between the outer wall of the mandrel and the inner wall of the die head. Molten material flows through the extrusion channel, and the molten material flows from the extrusion channel to the forming channel. The outer wall of the mandrel is provided with a protruding part. The extrusion channel includes a compression zone, and the protruding part and the inner wall of the die head form the compression zone.

[0005] The utility model is further provided with a plurality of protruding parts which are arranged at intervals along the axial direction of the mandrel. The extrusion channel between the adjacent two protruding parts forms a second buffer compression zone, and the cross-sectional area of the second buffer compression zone is greater than that of the compression zone.

[0006] The utility model is further provided with a hole one, and the wall surface of the hole one and the outer wall of the mandrel form the extrusion channel.

[0007] The utility model is further provided with a hole one, and the wall surface of the hole one and the outer wall of the mandrel form the extrusion channel.

[0008] The utility model is further provided with a hole one, and the wall surface of the hole one and the outer wall of the mandrel form the extrusion channel.

[0009] The utility model is further provided with a hole one, and the wall surface of the hole one and the outer wall of the mandrel form the extrusion channel.

[0010] The present invention is further configured to include a flow divider cone, the flow divider cone including a flow divider cone support located on the radially outer side, the flow divider cone support being inserted into and fixed to the rear mold body, and the flow divider cone being fixedly connected to the mandrel.

[0011] The present invention is further configured such that a cavity is formed between the outer wall of the diversion cone and the rear mold body and the front mold body, the cavity is connected to the extrusion channel, and the side of the cavity away from the extrusion channel is the feeding end.

[0012] The present invention is further configured such that the flow divider cone also includes ribs, which are distributed at intervals along the circumference of the flow divider cone, and the ribs connect the flow divider cone and the flow divider cone support.

[0013] In summary, this utility model has the following beneficial effects:

[0014] 1. By recompressing and fusing the molten plastic material after it is extruded through the screw into the cavity, extrusion channel, and molding channel, the residence time of the molten plastic material in the molding die is increased, reducing the occurrence of screw marks on the inner wall of the pipe.

[0015] 2. The sudden compression in the compression zone causes the molten material to be re-fused. Since the protrusion is located inside the flowing melt, the inner wall of the melt is squeezed more, thus reducing the appearance of screw marks on the inner wall of the melt. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of an embodiment.

[0017] Reference numerals: Die 1, Channel 1 11, Channel 2 12, Mandrel 2, Protrusion 21, Straight section 22, Diverter cone 3, Diverter cone support 31, Rib 32, Rear mold body 4, Front mold body 5, Auxiliary frame 6, Cavity 7, Extrusion channel 71, Compression zone 72, Buffer compression zone 73, Forming channel 74. Detailed Implementation

[0018] 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.

[0019] like Figure 1As shown, this embodiment discloses a pipe extrusion forming die for forming plastic pipe fittings. The forming die includes a rear die body 4, and a front die body 5 is fixedly installed on the right end of the rear die body 4. A flow divider cone 3 is installed on the inner wall of the rear die body 4. Specifically, the flow divider cone 3 includes a flow divider cone support 31 located on the radially outer side. The flow divider cone support 31 is inserted into the rear die body 4, and the left end of the front die body 5 is inserted into the rear die body 4 and abuts against the right end of the flow divider cone support 31. After the rear die body 4 and the front die body 5 are connected by screws, the rear die body 4 and the front die body 5 press and fix the flow divider cone support 31. The flow divider cone 3 also includes ribs 32, which are distributed at intervals along the circumference of the flow divider cone 3. There are three or six ribs 32. The larger the size of the flow divider cone 3, the more ribs 32 are provided to provide sufficient strength support. The ribs 32 connect the flow divider cone 3 and the flow divider cone support 31.

[0020] A cavity 7 is formed between the outer wall of the diversion cone 3 and the rear mold body 4 and the front mold body 5. After the screw extruder extrudes the plastic melt into shape, it immediately enters the cavity 7. At this time, the temperature of the plastic melt is still relatively high, and it can be reshaped. Figure 1 In the middle, the left side of cavity 7 is the feeding end. After the plastic body enters cavity 7, it is cut open by rib 32, and then fused again in cavity 7.

[0021] The flow divider cone 3 is fixedly connected to the mandrel 2 via a connecting block, and the mandrel 2 is threadedly inserted into the connecting block for fixation. The outer wall of the mandrel 2 is provided with protrusions 21, multiple of which are spaced apart along the axial direction of the mandrel 2. The outer wall of the protrusions 21 is arc-shaped along the axial direction of the mandrel 2 to reduce flow resistance. The mandrel 2 also includes a straight section 22, located on one side of the mandrel 2 along the material flow direction.

[0022] The forming mold also includes an auxiliary frame 6, on which a die 1 is mounted, passing through the auxiliary frame 6. The die 1 is inserted into the front mold body 5, and the outer peripheral wall of the die 1 is tightly sealed to the inner peripheral wall of the die 1. The mandrel 2 passes through the die 1, which includes a first channel 11 and a second channel 12. The second channel 12 is located on the side of the first channel 11 along the material flow direction and is connected to the first channel 11. The first channel 11 is a conical hole. The mandrel 2 is inserted into the first channel 11, and the wall of the first channel 11 and the outer wall of the mandrel 2 form an extrusion channel 71, which is connected to the extrusion channel 71. The straight part 22 is inserted into the second channel 12, and a forming channel 74 is formed between the second channel 12 and the straight part 22. The molten material flows from the extrusion channel 71 to the forming channel 74. After the molten material is shaped in the forming channel 74, it flows out and cools to form the final shape.

[0023] The extrusion channel 71 includes a compression zone 72, which is formed by the protrusion 21 and the inner wall of the die 1. The extrusion channel 71 between two adjacent protrusions 21 forms a second buffer compression zone 73, the cross-sectional area of ​​which is larger than that of the compression zone 72. When the molten material flows within the extrusion channel 71, the sudden compression in the compression zone 72 causes the molten material to be re-fused. Because the protrusion 21 is located inside the flowing melt, the compression on the inner wall of the melt is greater, thus reducing the appearance of screw marks on the inner wall of the melt.

[0024] Along the direction of molten material flow, the minimum diameter difference between the protrusion 21 and the inner wall of the die 1 gradually decreases, causing the melt to be compressed layer by layer, reducing the appearance of screw marks.

[0025] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A pipe extrusion forming die, characterized in that, The device includes a die (1) and a mandrel (2). The mandrel (2) passes through the die (1). An extrusion channel (71) and a forming channel (74) are formed between the outer wall of the mandrel (2) and the inner wall of the die (1). Molten material flows through the extrusion channel (71) and from the extrusion channel (71) to the forming channel (74). The outer wall of the mandrel (2) is provided with a protrusion (21). The extrusion channel (71) includes a compression zone (72). The protrusion (21) and the inner wall of the die (1) form the compression zone (72).

2. The pipe extrusion forming die according to claim 1, characterized in that, The protrusions (21) are spaced apart along the axial direction of the mandrel (2), and the extrusion channel (71) between two adjacent protrusions (21) forms a second buffer compression zone (73). The cross-sectional area of ​​the second buffer compression zone (73) is larger than the cross-sectional area of ​​the compression zone (72).

3. The pipe extrusion forming die according to claim 1, characterized in that, The die (1) includes a channel (11), and the wall of the channel (11) and the outer wall of the mandrel (2) form the extrusion channel (71).

4. The pipe extrusion forming die according to claim 1, characterized in that, Along the direction of molten material flow, the minimum diameter difference between the protrusion (21) and the inner wall of the die (1) gradually decreases.

5. The pipe extrusion forming die according to claim 1, characterized in that, The mandrel (2) includes a straight portion (22), and the die (1) includes a second channel (12), forming the molding channel (74) between the second channel (12) and the straight portion (22).

6. The pipe extrusion forming die according to claim 1, characterized in that, It also includes a rear mold body (4), on which a front mold body (5) is installed, and the die (1) is inserted into the front mold body (5), with the outer peripheral wall of the die (1) and the inner peripheral wall of the die (1) being tightly sealed.

7. A pipe extrusion forming die according to claim 6, characterized in that, It also includes a flow divider cone (3), which includes a flow divider cone support (31) located on the radially outer side. The flow divider cone support (31) is inserted into and fixed to the rear mold body (4). The flow divider cone (3) is fixedly connected to the mandrel (2).

8. A pipe extrusion forming die according to claim 7, characterized in that, A cavity (7) is formed between the outer wall of the diversion cone (3) and the rear mold body (4) and the front mold body (5). The cavity (7) is connected to the extrusion channel (71), and the side of the cavity (7) away from the extrusion channel (71) is the feeding end.

9. A pipe extrusion forming die according to claim 7, characterized in that, The flow divider cone (3) further includes ribs (32), which are distributed circumferentially along the flow divider cone (3) and connect the flow divider cone (3) to the flow divider cone support (31).

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