Pipe forming device and process thereof

Abstract

The invention provides a pipe forming device and a process thereof, and relates to the field of pipe forming, the pipe forming device comprises an extruder and a cooling setting machine, a feed port of the cooling setting machine corresponds to a machine head of the extruder, the extruder comprises a body, a core rod and a mouth mold, the core rod is mounted at the machine head of the body, the mouth mold is sleeved on the core rod, and a pipe can be extruded between the mouth mold and the core rod; the cooling setting machine comprises a shell and a setting mold, the setting mold is installed in the shell, a cooling cavity and a vacuum cavity are formed between the setting mold and the shell, and a plurality of vacuum openings communicated with the interior of the setting mold are formed in the positions, corresponding to the vacuum cavity, of the setting mold. The shell is provided with a vacuum pipe for vacuumizing the vacuum cavity and a cooling pipe for introducing cooling water into the cooling cavity; an air channel is formed in the core rod and is used for ventilating the stock mold; a plunger is arranged at the end, away from the core rod, in the shaping mold. According to the invention, the pipeline sizing requirements of high-difficulty processing materials with low melt strength and low crystallization rate can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pipe forming processing, in particular to a pipe forming device and a pipe forming process thereof. BACKGROUND

[0002] In pipe extrusion forming, sizing and cooling process are the core links to ensure processing precision, which directly determine the surface roughness and dimensional accuracy of the pipe. The outer diameter sizing is achieved by making the pipe blank tightly contact with the inner wall of the sizing sleeve, and the mainstream method is vacuum adsorption sizing method (vacuum suction on the outer wall). Among them, the vacuum adsorption sizing method becomes the mainstream in the plastic pipe industry because of its wide applicability; the pipe blank is attached to the inner wall of the sizing sleeve by vacuum suction on the outer wall of the pipe, which is suitable for general materials such as PVC, PE and PP.

[0003] However, for polyester special materials such as PET, the melt viscosity of PET after melting is low, the strength is weak, and the crystallization rate is slow. If the mainstream vacuum adsorption sizing method is used, the pipe blank is prone to "sag" and "collapse" after extrusion, and this problem is more prominent for large-diameter and thin-wall pipes. Therefore, the existing sizing technology cannot meet the pipe sizing needs of high-difficulty processing materials with low melt strength and slow crystallization rate (such as PET). SUMMARY

[0004] Therefore, in order to solve the problem that the existing sizing technology cannot meet the pipe sizing needs of high-difficulty processing materials with low melt strength and slow crystallization rate, the present application provides a pipe forming device, and the specific technical scheme is as follows: A pipe forming device, comprising an extruder and a cooling and sizing machine, the feeding port of the cooling and sizing machine corresponds to the head of the extruder, the extruder comprises a body, a mandrel and a die, the mandrel is installed at the head of the body, the die is sleeved on the mandrel, and the die and the mandrel are provided for pipe extrusion; the cooling and sizing machine comprises a shell and a sizing die, the sizing die is installed in the shell, a cooling cavity and a vacuum cavity are formed between the sizing die and the shell, a plurality of vacuum ports are formed in the sizing die corresponding to the position of the vacuum cavity and are in communication with the sizing die, the shell is provided with a vacuum pipe for vacuumizing the vacuum cavity and a cooling pipe for passing cooling water into the cooling cavity; the mandrel is provided with an air channel, the air channel is used for passing air into the sizing die; and the sizing die is provided with a plunger at an end away from the mandrel.

[0005] By adopting the technical scheme, after the pipe blank is extruded, the pipe blank enters into the sizing die, vacuum is drawn in the vacuum cavity, the outer wall of the pipe blank is tightly attached to the inner wall of the sizing die, and compressed gas is introduced into the pipe blank through the air passage, so that positive air pressure is applied to the inside of the pipe blank, and the inner wall of the pipe blank is supported; therefore, after cooling water is introduced into the cooling cavity, the pipe blank can be fully cooled, the pipe blank material is quickly crystallized and formed, and the pipe blank is prevented from sagging and collapsing after being extruded; and the pressure intensity of the compressed air can be controlled to adjust the wall thickness of the pipe, and higher quality pipe can be produced.

[0006] Further, the sizing die is connected with a connecting rod, one end of the connecting rod is fixedly connected with the core rod, and the other end of the connecting rod is fixedly connected with the plunger.

[0007] Further, the connecting rod is hollow, a plurality of air passages are uniformly arranged on the connecting rod in the circumferential direction, and the connecting rod is in communication with the air passage.

[0008] Further, the cooling cavity is provided in pairs, and the vacuum cavity is located between the two cooling cavities.

[0009] Further, the device further comprises a raw material hopper, an elevator and a feeding mechanism, the raw material hopper is arranged on one side of the extruder, the feeding inlet of the elevator is located at the bottom of the raw material hopper, and the discharging outlet of the elevator is located directly above the feeding inlet of the extruder; the feeding mechanism is used for adding raw materials in a raw material bag into the raw material hopper.

[0010] Further, the feeding mechanism comprises a pair of conveying belts, a cutter and a bag hanging assembly, the two conveying belts are arranged horizontally opposite to each other, the two conveying belts are arranged obliquely downward from the sides away from each other to the sides close to each other, and the conveying belts are arranged above the raw material hopper at the positions close to the discharging ends; the cutter is arranged between the two conveying belts, the cutter is located at a position corresponding to the raw material hopper, and the cutting edge of the cutter is arranged vertically upward; the bag hanging assembly is arranged at a position corresponding to the cutter, and the bag hanging assembly is used for limiting the raw material bag on the conveying belt.

[0011] Further, the bag hanging assembly comprises a mounting frame, a rotating seat, a hook and a first driving member, the mounting frame is located on one side of the raw material hopper, the rotating seat is mounted on the mounting frame, one end of the hook is rotatably mounted on the rotating seat, the other end of the hook is provided with a hook body, and one side of the hook body downward is in the shape of a cutting edge; the first driving member is used for driving the hook to rotate; the mounting frame is provided with a second driving member for driving the rotating seat to move towards the conveying belt, and a third driving member for driving the rotating seat to move vertically.

[0012] Further, a plurality of prongs are arranged on the conveying belt at intervals in the conveying direction and located on the top of the conveying belt, and the prongs extend upwardly and obliquely from the conveying belt.

[0013] Further, a support is fixedly installed on the bottom of the two conveying belts, and a plug-in rod is fixedly installed on the bottom of the cutter, a plug-in slot is formed in the support, and the plug-in rod is plugged into the plug-in slot.

[0014] The present application provides a pipe forming process, and the specific technical scheme is as follows: A pipe forming process based on the pipe forming device, and the forming process comprises the following steps: Step one: after the pipe blank is extruded from the position between the die and the mandrel, the pipe blank enters the sizing die; Step two: vacuum is drawn in the vacuum cavity through the vacuum pipe, so that the outer wall of the pipe blank is tightly attached to the inner wall of the sizing die; at the same time, cooling water is supplied to the cooling cavity through the cooling pipe; Step three: compressed air is supplied into the pipe blank through the air duct, so that a closed positive pressure air atmosphere is formed in the pipe blank, and the inner diameter is sized. BRIEF DESCRIPTION OF DRAWINGS

[0015] The present application can be further understood from the following description in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but the emphasis is placed on showing the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0016] Figure 1 is a schematic view of the overall structure of an embodiment of the present application; Figure 2 is a sectional view of the internal structure of the cooling and sizing machine of an embodiment of the present application; Figure 3 is a schematic view of the feeding mechanism structure of an embodiment of the present application; Figure 4 is a schematic view of the feeding mechanism structure of an embodiment of the present application from another perspective; Figure 5 is Figure 4 is a partial enlarged view of A in FIG.

[0017] Explanation of reference numerals: 1, extruder; 11, body; 12, mandrel; 121, air inlet; 122, air outlet; 13, die; 14, plunger; 15, connecting rod; 2, cooling and shaping machine; 21, shell; 22, shaping die; 23, cooling cavity; 24, vacuum cavity; 25, water inlet pipe; 26, water outlet pipe; 27, vacuum pipe; 3, raw material hopper; 4, elevator; 5, feeding mechanism; 51, conveying belt; 511, piercing rod; 512, support; 513, insertion slot; 514, mounting slot; 52, cutter; 521, insertion rod; 53, mounting frame; 54, rotating seat; 55, hook; 56, first driving member; 57, second driving member; 58, third driving member; 59, collection box; 6, limiting assembly; 61, rack; 62, gear; 63, elastic member. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments thereof. It should be understood that the specific embodiments described herein are merely intended to explain the present application and not to limit the protection scope of the present application.

[0019] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements can also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be limiting.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0021] The terms "first", "second", etc. in the present application do not represent a specific number and order, but are only used for distinguishing names.

[0022] As Figure 1 and Figure 2As shown, the pipe forming device in an embodiment of the present application comprises an extruder 1 and a cooling and shaping machine 2, the feeding port of the cooling and shaping machine 2 corresponds to the head of the extruder 1, the extruder 1 comprises a body 11, a mandrel 12 and a die 13, the mandrel 12 is installed at the head of the body 11, the die 13 is sleeved on the mandrel 12, and the die 13 and the mandrel 12 are provided for pipe extrusion; the cooling and shaping machine 2 comprises an outer shell 21 and a shaping die 22, the shaping die 22 is installed in the outer shell 21, a cooling cavity 23 and a vacuum cavity 24 are formed between the shaping die 22 and the outer shell 21, the cooling cavity 23 is provided in a pair, and the vacuum cavity 24 is located between the two cooling cavities 23; the shaping die 22 is provided with a plurality of vacuum ports corresponding to the position of the vacuum cavity 24 and communicating with the inside of the shaping die 22, so that the outer wall of the pipe blank can be tightly attached to the inner wall of the shaping die 22; the outer shell 21 is provided with a vacuum pipe 27 for vacuumizing the vacuum cavity 24 and a cooling pipe for passing cooling water into the cooling cavity 23, the cooling pipes are provided on both sides of the outer shell 21, the cooling pipe on one side is the water inlet pipe 25, and the cooling pipe on the other side is the water outlet pipe 26, so that cooling water can be passed into the water inlet pipe 25 and the cooling cavity 23, and the pipe blank can be cooled and shaped.

[0023] The mandrel 12 is provided with an air channel, the air channel is used for passing air into the shaping die 22, that is, passing air into the pipe blank in the shaping die, the air channel comprises an air inlet 121 and an air outlet 122, and the air inlet 121 and the air outlet 122 are installed on the body 11; the shaping die 22 is provided with a plunger 14 at the end away from the mandrel 12; so that the positive air pressure can be applied to the inside of the pipe blank, the inside wall of the pipe blank is supported, the material is quickly crystallized and formed, and the "sagging" and "collapse" of the pipe blank after extrusion are prevented.

[0024] Specifically, as shown in Figure 1 and Figure 2 , the shaping die 22 is connected with a connecting rod 15, one end of the connecting rod 15 is fixedly connected with the mandrel 12, and the other end is fixedly connected with the plunger 14; the connecting rod 15 is hollow, a plurality of air ports are uniformly arranged on the connecting rod 15 in the circumferential direction, and the connecting rod 15 is in communication with the air inlet 121; so that the plunger 14 can be installed, and the gas passed into the pipe blank is more uniform, and the support effect of the inside wall of the pipe blank is improved.

[0025] Specifically, as shown in Figure 1 , Figure 3 and Figure 4As shown, the pipe forming device further comprises a raw material hopper 3, an elevator 4 and a feeding mechanism 5, the raw material hopper 3 is arranged at one side of the extruder 1; the elevator 4 is a spiral conveying elevator 4, the feeding inlet of the elevator 4 is located at the bottom of the raw material hopper 3, and the discharging outlet of the elevator 4 is located directly above the feeding inlet of the extruder 1; the feeding mechanism 5 is used for adding raw materials in the raw material bag into the raw material hopper 3; so that the raw materials can be added into the raw material hopper 3 through the feeding mechanism 5, and then the raw materials in the raw material hopper 3 are conveyed into the feeding inlet of the extruder 1 through the elevator 4.

[0026] The feeding mechanism 5 comprises a pair of conveying belts 51, a cutter 52 and a bag hanging assembly, the two conveying belts 51 are arranged horizontally opposite to each other, and are arranged obliquely downward from the sides far away from each other to the sides close to each other, and the conveying belts 51 are arranged at the positions directly above the raw material hopper 3 at the positions close to the discharging end; so that the workers can place the raw materials at the feeding end positions of the two conveying belts 51, and the raw materials are conveyed to the positions directly above the raw material hopper 3 through the two conveying belts 51; the cutter 52 is arranged at the position between the two conveying belts 51, the cutter 52 is located at the position corresponding to the raw material hopper 3, and the cutting edge of the cutter 52 is arranged vertically upward; so that when the raw materials are conveyed to the positions directly above the raw material hopper 3, the raw material bag can be cut open through the cutter 52.

[0027] As shown in the drawings, Figure 3 , Figure 4 and Figure 5As shown, the bag hanging assembly is arranged at the position corresponding to the cutter 52, and is used to restrict the raw material bag on the conveying belt 51; the bag hanging assembly comprises a mounting frame 53, a rotating seat 54, a hook 55 and a first driving member 56, the mounting frame 53 is located at one side of the raw material hopper 3, and the rotating seat 54 is mounted on the mounting frame 53; the hook 55 is arranged in a pair, one end of the two hooks 55 is rotatably mounted on the rotating seat 54, and the other end is provided with a hook body, and the downward side of the hook body is in the shape of a blade; the first driving member 56 is used to drive the hook 55 to rotate, and the first driving member 56 is a motor, and the output shaft of the first driving member 56 is fixedly connected with the rotating shaft of the hook 55; the mounting frame 53 is provided with a second driving member 57 used to drive the rotating seat 54 to move towards the conveying belt 51 or away from the conveying belt 51, and a third driving member 58 used to drive the rotating seat 54 to move in the vertical direction, the second driving member 57 is a screw rod motor module, and the rotating seat 54 is fixedly mounted on the moving seat of the driving assembly; the third driving member 58 is a pneumatic cylinder, and the third driving member 58 is fixedly mounted on the mounting frame 53, and the piston rod of the third driving member 58 is fixedly connected with the second driving member 57; so that when the raw material bag is conveyed to the position directly above the raw material hopper 3, the cutter 52 cuts the bottom of the raw material bag, at this time, the cutter 52 is still at the cutting position, and therefore the raw material cannot slide out of the raw material bag, at this time, the first driving member 56 is used to drive the hook 55 to rotate, so that the hook body is hooked into the top of the raw material bag, then the second driving member 57 is used to drive the hook body to move back, and the third driving member 58 is used to drive the hook body to move vertically upwards, so that the raw material bag is lifted upwards, and the cutter 52 leaves the raw material bag, at this time, the raw material in the raw material bag can fall into the raw material hopper 3, and the automatic feeding is completed.

[0028] A plurality of spike rods 511 are arranged on the conveying belt 51 away from the raw material hopper 3 and are spaced apart along the conveying direction, the spike rods 511 are located at the top of the conveying belt 51, and the spike rods 511 extend obliquely upwards from the conveying belt 51; a collection box 59 is placed directly below the tail end of the conveying belt 51; so that when the raw material bag is empty, the second driving member 57 is used to drive the hook 55 to move back at the same time, and the raw material bag is moved together until the raw material bag is hooked on the spike rod 511, and is conveyed together with the conveying belt 51 until the raw material bag is conveyed to the position directly above the collection box 59, and then the raw material bag can fall into the collection box 59 for collection.

[0029] As Figure 3 , Figure 4 and Figure 5As shown, the bottom of the rack of the two conveyors 51 is fixedly provided with a support 512, the bottom of the cutter 52 is fixedly provided with a plug-in rod 521, the support 512 is provided with a plug-in slot 513, the plug-in rod 521 is plugged into the plug-in slot 513, the support 512 is provided with a limiting assembly 6 for limiting the plug-in rod 521 in the plug-in slot 513, the limiting assembly 6 comprises a pair of racks 61, a gear 62 and an elastic member 63, the support 512 is provided with a mounting slot 514, the gear 62 is vertically arranged and rotatably mounted in the mounting slot 514, the two racks 61 are slidably mounted on the two sides of the gear 62, and the two racks 61 are in engagement with the gear 62; one end of one rack 61 is inserted into the plug-in slot 513 and plugged into the plug-in rod 521, and the other rack 61 extends out of the support 512 and is opposite to the position of the rotating seat 54; the elastic member 63 is a spring, and the elastic member 63 is fixedly mounted on the end of the rack 61; so that the rotating seat 54 is driven to move towards the support 512 until the rack 61 is pushed, the gear 62 is linked to drive the other rack 61 to move away from the plug-in rod 521, and the cutter 52 is unlocked, so that the worker only needs to take the cutter 52 away from above the conveyor 51, thereby reducing the complexity of replacing the cutter 52 and improving the safety.

[0030] The working principle of the pipe forming device is that the worker can place the raw material at the feeding end position of the two conveyors 51, and the raw material is conveyed to the position directly above the raw material hopper 3 through the two conveyors 51; when the raw material is conveyed to the position directly above the raw material hopper 3, the raw material bag can be cut open by the cutter 52; the hook body is hooked into the top of the raw material bag by rotating the hook 55 driven by the first driving member 56, and the raw material bag is lifted upwards by the cooperation of the second driving member 57 and the third driving member 58, so that the cutter 52 moves away from the raw material bag, at this time, the raw material in the raw material bag falls into the raw material hopper 3, and the automatic feeding is completed; then the hook 55 is continuously driven to move back while driving the raw material bag to move together, until the raw material bag is hooked on the stab rod 511, and is conveyed together with the conveyor 51, until it is conveyed to the position directly above the collection box 59, and the raw material bag falls into the collection box 59 for collection.

[0031] The pipe forming process also discloses a pipe forming process, which comprises the following steps: S10: the pipe blank is extruded from the position between the die and the mandrel and then enters the sizing die; S20: vacuum is drawn in the vacuum cavity through the vacuum pipe, so that the outer wall of the pipe blank closely adheres to the inner wall of the sizing die; at the same time, cooling water is supplied to the cooling cavity through the cooling pipe; S30: compressed air is supplied into the pipe blank through the air passage, so that a closed positive pressure air atmosphere is formed in the pipe blank, and the inner diameter is sized.

[0032] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, as long as the combination of the technical features does not exist in contradiction, it shall be considered within the scope of the present disclosure.

[0033] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the patent scope of the present application. It shall be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A pipe forming apparatus, characterized in that, The device includes an extruder and a cooling and shaping machine. The feed inlet of the cooling and shaping machine corresponds to the die head of the extruder. The extruder includes a body, a mandrel, and a die. The mandrel is installed at the die head of the body, and the die is fitted onto the mandrel, allowing for the extrusion of tubing between the die and the mandrel. The cooling and shaping machine includes a housing and a shaping die. The shaping die is installed inside the housing, forming a cooling chamber and a vacuum chamber between the shaping die and the housing. The shaping die has several vacuum ports corresponding to the vacuum chamber, communicating with the inside of the shaping die. The housing has a vacuum pipe for evacuating the vacuum chamber and a cooling pipe for circulating cooling water through the cooling chamber. The mandrel has an air passage for venting air into the shaping die. A plunger is provided at the end of the shaping die away from the mandrel.

2. The pipe forming apparatus according to claim 1, characterized in that, A connecting rod is connected inside the molding die, with one end of the connecting rod fixedly connected to the mandrel and the other end fixedly connected to the plunger.

3. The pipe forming apparatus according to claim 2, characterized in that, The connecting rod is hollow and has several vents evenly arranged around its circumference. The interior of the connecting rod is connected to the air passage.

4. The pipe forming apparatus according to claim 1, characterized in that, The cooling chambers are provided in pairs, and the vacuum chamber is located between the two cooling chambers.

5. A pipe forming apparatus according to claim 1, characterized in that, It also includes a raw material hopper, an elevator, and a feeding mechanism. The raw material hopper is located on one side of the extruder, the feed inlet of the elevator is located at the bottom of the raw material hopper, and the discharge outlet of the elevator is located directly above the feed inlet of the extruder. The feeding mechanism is used to add the raw material from the raw material bag into the raw material hopper.

6. A pipe forming apparatus according to claim 2, characterized in that, The feeding mechanism includes a pair of conveyor belts, a cutter, and a bag-hanging assembly. The two conveyor belts are arranged horizontally opposite each other, and are inclined downwards from the side furthest from each other towards the side closest to each other. The conveyor belts are positioned directly above the raw material hopper near the discharge end. The cutter is positioned between the two conveyor belts, corresponding to the position of the raw material hopper, with its blade pointing vertically upwards. The bag-hanging assembly is positioned corresponding to the cutter and is used to hold the raw material bags on the conveyor belts.

7. A pipe forming apparatus according to claim 6, characterized in that, The bag hanging assembly includes a mounting frame, a rotating seat, a hook, and a first driving component. The mounting frame is located on one side of the raw material hopper. The rotating seat is mounted on the mounting frame. One end of the hook is rotatably mounted on the rotating seat, and the other end is provided with a hook body, the downward-facing side of which is blade-shaped. The first driving component is used to drive the hook to rotate. The mounting frame is equipped with a second driving component for driving the rotating seat to move closer to or away from the conveyor belt, and a third driving component for driving the rotating seat to move vertically.

8. A pipe forming apparatus according to claim 7, characterized in that, A number of spikes are spaced apart along the conveying direction on the conveyor belt located on the side away from the raw material hopper. The spikes are all located at the top of the conveyor belt and extend obliquely upward from the conveyor belt. A collection box is placed directly below the tail end of the conveyor belt.

9. A pipe forming apparatus according to claim 7, characterized in that, The bottom of the two conveyor belts is fixedly equipped with a bracket, and the bottom of the cutter is fixedly equipped with a plug rod. The bracket is provided with a plug groove, and the plug rod is inserted into the plug groove. The bracket is equipped with a limiting component for limiting the plug rod in the plug groove.

10. A pipe forming process, based on the pipe forming apparatus according to claim 1, characterized in that, The molding process includes the following steps: Step 1: The tube blank is extruded from the position between the die and the mandrel and then enters the shaping mold; Step 2: Evacuate the vacuum chamber through the vacuum tube, so that the outer wall of the tube blank is tightly attached to the inner wall of the forming mold; at the same time, cool water is supplied to the cooling chamber through the cooling tube. Step 3: Compressed air is introduced into the tube blank through the air passage to form a closed positive pressure air atmosphere inside the tube blank, thereby achieving inner diameter sizing.

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