Pipe extrusion die with cooling device

Abstract

The utility model discloses a pipe extrusion die with a cooling device, the pipe extrusion die is provided with one or more feeding interfaces, the feeding interfaces are connected with the cooling device, the cooling device comprises a main machine connector and a cooling body connected with the main machine connector through a feeding flow channel, and the cooling body is connected with the main machine connector through a discharging flow channel. The downstream of the cooling body is communicated with a feeding connector of the extrusion die through a discharging flow channel, a first material flow channel is formed in the cooling body, and the cooling body comprises a cooling inner sleeve and an outer die sleeve arranged on the peripheral side of the cooling inner sleeve in a sleeving mode. At least part of the first material flow channel is limited by the cooling inner sleeve, and a cooling flow channel is formed in the peripheral face of the cooling inner sleeve.

Description

Technical Field

[0001] The present application relates to the technical field of plastic molding, and in particular to a pipe extrusion die with a cooling device. Background Art

[0002] Traditional large-diameter solid-wall pipe single-layer molds typically use a single extruder to provide the required output. In actual production, a single extruder provides the required output. Due to the large-diameter pipe, the material generates a lot of heat inside the main machine. The internal heating of the mold and the shearing effect of the material cause even greater heat to be generated at the exit die and mandrel. As a result, during the production of the finished product, when the blank passes through the vacuum chamber for cooling, the heat inside the blank dissipates, the outer surface cools, and the inner core is still in a molten state. The latter part may collapse or deviate from the wall, causing the pipe to not form, affecting the quality and appearance of the product. Summary of the Invention

[0003] The purpose of the present application is to solve the problem of internal collapse of pipes in the prior art. The present application provides a pipe extrusion die with a cooling device.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solution: a pipe extrusion die with a cooling device, the pipe extrusion die has one or more feed interfaces, the feed interface is connected to a cooling device, the cooling device includes a main connector, a cooling body connected to the main connector through an inlet channel, the downstream of the cooling body is connected to the feed joint of the extrusion die through a discharge channel, a first material flow channel is provided in the cooling body, the cooling body includes a cooling inner sleeve and an outer mold sleeve arranged on the outer peripheral side of the cooling inner sleeve, at least part of the first material flow channel is defined by the cooling inner sleeve, and a cooling flow channel is provided on the outer peripheral surface of the cooling inner sleeve.

[0005] In a possible implementation, the outer mold sleeve has a coolant inlet and a coolant outlet respectively connected to the head and tail ends of the cooling channel.

[0006] In a possible implementation, the cooling body includes a diverter cone, a tail mold sleeve and the cooling inner sleeve respectively enveloping the outer side of the diverter cone.

[0007] In one possible implementation, the diverter cone has a rear cone portion located upstream of the first material flow channel and a front cone portion located downstream of the first material flow channel, the cone surface of the front cone portion has adjacent protrusions and depressions, the protrusions are located upstream of the depressions, and the cross-section of the first material flow channel narrows at the protrusions and widens at the depressions.

[0008] In a possible implementation, the conical surface of the front cone portion has a first slope upstream of the protrusion and a second slope downstream of the recess, and the second slope is greater than the first slope.

[0009] In a possible implementation, the cooling body further includes a diverter bracket located between the tail mold sleeve and the cooling inner sleeve.

[0010] In a possible implementation, a heating and cooling device is further provided inside the diverter cone.

[0011] In a possible implementation, the pipe extrusion die has two feed interfaces, and each feed interface is connected to one cooling device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a cross-sectional schematic diagram of a pipe extrusion die in the prior art.

[0013] Figure 2 This is a top view of the pipe extrusion die provided in an embodiment of the present application.

[0014] Figure 3 for Figure 2 Cross-section along AA.

[0015] Figure 4 This is a schematic cross-sectional view of the cooling channel provided in an embodiment of the present application.

[0016] Figure 5 This is a left view of the cooling channel provided in an embodiment of the present application.

[0017] Figure 6 for Figure 5 Cross-section along the middle BB.

[0018] Wherein: 100, cooling device; 1, main engine connector; 2, elbow; 3, inlet flow channel; 4, tail mold sleeve; 5, diverter bracket; 6, diverter cone; 61, rear cone; 62, front cone; 63, depression; 64, protrusion; 7, outer mold sleeve; 71, coolant inlet; 72, coolant outlet; 8, cooling inner sleeve; 9, heating and cooling device; 10, mold core; 11, discharge flow channel; 12, first material flow channel;

[0019] 200, extrusion die; 21, feed connector;

[0020] 300. Existing extrusion die; 31. Feed interface; 32. First outer die sleeve; 33. Transition sleeve; 34. Second material flow channel; 35. Mouth die; 36. Core die; 37. Spiral; 38. Water cooling jacket. DETAILED DESCRIPTION

[0021] In order to describe the technical content, structural features, achieved purposes and effects of the invention in detail, the technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. In the following description, for the purpose of explanation, many specific details are set forth to provide a detailed description of various exemplary embodiments or implementations of the invention. However, various exemplary embodiments may also be implemented without these specific details or in the presence of one or more equivalent arrangements. In addition, various exemplary embodiments may be different, but are not necessarily exclusive. For example, without departing from the inventive concept, the specific shape, structure and characteristics of the exemplary embodiment may be used or implemented in another exemplary embodiment.

[0022] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0023] In this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0024] like Figure 1 The figure shows the structure of a conventional extrusion die 300, which typically comprises a feed port 31, a spiral 37, a core die 36, a first outer die sleeve 32 sleeved around the spiral 37, a die 35 sleeved around the core die 36, and a second material flow channel 34 for molten material to flow between the core die 36 and the die 35. The feed port 31 is typically connected to the barrel of a screw extruder, thereby feeding the molten material into the extrusion die. After being extruded and mixed by the spiral 37, the material is extruded through the second material flow channel 34.

[0025] and Figure 2As shown, a pipe extrusion die with a cooling device is provided as an embodiment of the present application. The pipe extrusion die 200 has two feed interfaces 21, and the internal structure of the extrusion die 200 can adopt the structure of an existing pipe extrusion die. The two feed interfaces 21 are respectively connected to the two cooling devices 100, and the upstream of the two cooling devices are respectively connected to the two screw extruders. Using two screw extruders for feeding can reduce the output of each screw extruder. By extruding at a low speed and low temperature, the plasticization degree of the blank can be greatly improved, and the overall temperature of the material can also be reduced, which is convenient for the subsequent forming of the pipe and is also conducive to improving the quality and appearance of the pipe.

[0026] See also Figure 3-4 As shown, the arrow indicates the direction of fluid flow. The cooling device 100 comprises a main body connector 1 for connecting to the barrel of a screw extruder, and a cooling element. The upstream portion of the cooling element is connected to the main body connector 1 via an inlet channel 3, while the downstream portion of the cooling element is connected to the feed connector 21 of the extrusion die 200 via an outlet channel 11.

[0027] The cooling body includes a diverter cone 6 and a tail die sleeve 4, a diverter bracket 5, and a cooling inner sleeve 8, which are respectively enclosed on the outside of the diverter cone 6. A first material flow channel 12 is formed between the outer surface of the diverter cone 6 and the inner surfaces of the tail die sleeve 4 and the inner surface of the cooling inner sleeve 8. The upstream of the first material flow channel 12 is connected to the feed flow channel 3, and the downstream of the first material flow channel 12 is connected to the discharge flow channel 11. When the molten material enters the feed flow channel 3 through the main body connector 1, it is diverted by the diverter cone 6 in the cooling body into the first material flow channel 12. After being cooled by the cooling body, it is then delivered to the extrusion die 200 through the discharge flow channel 11.

[0028] In order to cool the material entering the cooling device 100, a spirally extending cooling channel is provided on the outer circumference of the cooling inner sleeve 8, such as Figure 4-6 As shown, an outer mold sleeve 7 is provided around the outer periphery of the cooling inner sleeve 8. The outer mold sleeve 7 has a coolant inlet 71 and a coolant outlet 72, respectively connected to the front and rear ends of the cooling channel. Cooling inner sleeve 8 can be rapidly cooled by injecting cold water into the liquid inlet 71. Since the cooling inner sleeve 8 directly forms part of the sidewall of the first material flow channel 12, the material can be quickly cooled.

[0029] The diverter cone 6 includes a rear cone portion 61 located upstream of the first material flow channel 12 and a front cone portion 62 located downstream of the first material flow channel 12. The front cone portion 62 has adjacent protrusions 64 and depressions 63 on its surface. The protrusions 64 are located upstream of the depressions 63. The cross-section of the first material flow channel 12 narrows at the protrusions 64 and widens at the depressions 63. The protrusions 64 and depressions 63 serve to compact the material.

[0030] Specifically, the conical surface of the front conical portion 62 has a first slope upstream of the protrusion 64 and a second slope downstream of the recess 63 , and the second slope is greater than the first slope.

[0031] The interior of the diverter cone 6 is also provided with a heating and cooling device 9, which can both heat and cool the diverter cone. The heating and cooling device 9 can heat the diverter cone before starting the machine to facilitate the flow of materials. During normal production, the heating and cooling device 9 can be switched from heating to cooling to cool the materials, effectively reducing the temperature inside the melt of the materials.

[0032] In this embodiment, the heating and cooling device 9 includes a metal mold core 10 installed inside the diverter cone and a heat exchanger installed outside the cooling body. A refrigerant channel is opened on the mold core 10, and the refrigerant channel is connected to the external refrigerant loop through the guide flow channel on the diverter bracket 5. The refrigerant loop adjusts the refrigerant temperature through the heat exchanger.

[0033] In some other embodiments, the heating and cooling device may also use an electric heating wire and a refrigerant channel to heat or cool the diverter cone respectively.

[0034] In order to further reduce the temperature of the extruded pipe and prevent deformation, a water cooling jacket 38 capable of cooling the core mold is provided at the core mold 36 of the pipe extrusion die.

[0035] The technical problem to be solved by the present invention is to provide a pipe extrusion die with a cooling device. Therefore, a cooling device is installed between the extrusion die and the screw extruder. The preform from the screw extruder is evenly distributed through a diverter cone. The surface temperature of the material is removed through several spiral cooling channels between the inner and outer cooling sleeves. The heating and cooling device cools the internal temperature of the material, thereby reducing the temperature of the inner and outer surfaces of the material.

[0036] Since the present application adopts two screw extruders for extrusion output, the output of each main machine can be reduced, and the output per unit speed can be reduced, which can greatly improve the plasticization of the main machine. At the same time, the heating temperature required by the main machine can also be kept at a relatively low temperature, which can greatly reduce the extrusion temperature of the extrusion die blank, thereby effectively controlling the sag of the pipe, reducing the cooling pressure of the subsequent vacuum box, and effectively improving the quality and appearance of the pipe.

[0037] The basic principles, main features and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims, the description and their equivalents.

Claims

1. A pipe extrusion die with a cooling device, the pipe extrusion die having one or more feed ports (21), characterized in that: The feed interface (21) is connected to a cooling device (100), the cooling device (100) comprises a main machine connector (1), a cooling body connected to the main machine connector (1) via an inlet flow channel (3), the downstream of the cooling body is connected to the feed interface (21) of the extrusion die (200) via a discharge flow channel (11), a first material flow channel (12) is provided in the cooling body, the cooling body comprises a cooling inner sleeve (8) and an outer mold sleeve (7) provided on the outer peripheral side of the cooling inner sleeve (8), at least part of the first material flow channel (12) is defined by the cooling inner sleeve (8), and a cooling flow channel is provided on the outer peripheral surface of the cooling inner sleeve (8).

2. The pipe extrusion die with a cooling device according to claim 1, characterized in that: The outer mold sleeve (7) has a cooling liquid injection port (71) and a cooling liquid discharge port (72) respectively connected to the head and tail ends of the cooling channel.

3. The pipe extrusion die with a cooling device according to claim 1, characterized in that: The cooling body comprises a diverter cone (6), a tail mold sleeve (4) and a cooling inner sleeve (8) respectively enveloping the outside of the diverter cone (6).

4. The pipe extrusion die with a cooling device according to claim 3, characterized in that: The diverter cone (6) has a rear cone (61) located upstream of the first material flow channel (12) and a front cone (62) located downstream of the first material flow channel (12). The cone surface of the front cone (62) has adjacent protrusions (64) and depressions (63). The protrusion (64) is located upstream of the depression (63). The cross-section of the first material flow channel (12) narrows at the protrusion (64) and widens at the depression (63).

5. The pipe extrusion die with a cooling device according to claim 4, characterized in that: The conical surface of the front cone (62) has a first slope upstream of the protrusion (64) and a second slope downstream of the recess (63), and the second slope is greater than the first slope.

6. The pipe extrusion die with a cooling device according to claim 3, characterized in that: The cooling body further comprises a diversion bracket (5) located between the tail mold sleeve (4) and the cooling inner sleeve (8).

7. The pipe extrusion die with a cooling device according to claim 3, characterized in that: A heating and cooling device (9) is also provided inside the diverter cone (6).

8. The pipe extrusion die with a cooling device according to claim 1, characterized in that: The pipe extrusion die has two feed interfaces (21), and each feed interface (21) is connected to one cooling device (100).

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