Plastic pipe forming mold

Abstract

The utility model discloses an air cooling structure of a plastic pipe and a forming mold, and belongs to the technical field of plastic pipe forming. The heat dissipation device comprises a flow guide part which is arranged in an inner cavity of the pipe, a first flow guide channel is formed between the flow guide part and the inner wall of the pipe, the first flow guide channel is connected with an external exhaust fan through an air draft channel, and heat in the pipe is exhausted outwards sequentially through the first flow guide channel and the air draft channel through the external exhaust fan. When the air cooling structure is applied to the forming die, the air draft channel is formed in the core position of the die body, and the flow guide piece is installed at the outlet end of the die body. In the air draft process, normal-temperature air flows close to the inner wall area of the pipe, the inner wall of the pipe can be rapidly and evenly cooled, on one hand, cooling and shaping of the pipe are accelerated through air cooling, cooling pressure is reduced for a follow-up cooling device, and on the other hand, pipe sagging is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of plastic pipe molding, and in particular relates to a plastic pipe molding die. Background Art

[0002] In the pipe forming process, the molten material is extruded from the extruder and then enters the mold for extrusion forming and then extruded outward. The extruded pipe is still in a high temperature state and needs to be cooled and shaped as soon as possible to avoid the problem of drooping.

[0003] Among them, after the pipe is formed and extruded from the mold, it is vacuum-formed by the cooperation of a sizing sleeve and a vacuum forming machine. At the same time, an air cooling structure can be equipped to cool the inner wall of the pipe. However, the current air cooling structure generally directly draws air into the inner cavity of the pipe, but this structure has the problems of low heat exchange efficiency and uneven cooling of the inner wall of the pipe. Summary of the invention

[0004] The utility model aims at solving the above problems in the prior art and proposes a plastic pipe forming die which can evenly cool the inner wall of the pipe.

[0005] The utility model can be realized through the following technical solutions:

[0006] A plastic pipe air cooling structure, comprising:

[0007] A flow guide is arranged in the inner cavity of the pipe, and a first flow guide channel is formed between the flow guide and the inner wall of the pipe. The first flow guide channel is connected to an external exhaust fan through an exhaust channel, and the heat in the pipe is extracted outward through the first flow guide channel and the exhaust channel in sequence by the external exhaust fan.

[0008] As a further improvement of the present invention, the guide member and the pipe are located on the same axis, and the outer circumferential wall of the guide member is parallel to the inner wall of the pipe, so that the first guide channel forms an annular channel.

[0009] As a further improvement of the present invention, a front guide cone is provided on the front end surface of the guide member, and air flows through the front guide cone and enters the first guide channel.

[0010] As a further improvement of the present invention, a rear end surface of the guide member is provided with a rear guide surface, and the air in the first guide channel flows along the rear guide surface and enters the exhaust channel.

[0011] As a further improvement of the present invention, the guide member has a cavity inside, and a plurality of air inlets are provided on the circumferential wall of the guide member, and the air flowing into the first guide channel can enter the cavity of the guide member through each of the air inlets.

[0012] As a further improvement of the present invention, the rear end of the guide member is connected to the air exhaust channel, and the air entering the cavity thereof is exhausted outward through the air exhaust channel.

[0013] As a further improvement of the present invention, the number and density of the air inlets gradually increase from the front end to the rear end of the circumferential wall of the guide member.

[0014] A forming die for a plastic pipe is also provided, which has the above-mentioned air cooling structure for the plastic pipe, including:

[0015] A die body, which extrudes the molten material into a tube and extrude it outward;

[0016] The exhaust channel is opened at the core position of the mold body, and the flow guide is installed at the outlet end of the mold body.

[0017] As a further improvement of the utility model, it also includes a sizing sleeve and a vacuum forming machine. The sizing sleeve is close to the outlet end of the mold body. The pipe passes through the sizing sleeve after being extruded from the mold body. The vacuum forming machine is located outside the sizing sleeve and can vacuum form the pipe in the sizing sleeve.

[0018] As a further improvement of the utility model, the mold body includes an inner mold core and an outer mold plate, and a melt flow channel for the melt material to flow is formed between the inner mold core and the outer mold plate, wherein:

[0019] The outer mold plate includes a fixed plate and an adjusting plate. The adjusting plate is movably abutted against the fixed plate. The movement of the adjusting plate changes the space of the melt flow channel to adjust the wall thickness of the pipe.

[0020] Compared with the prior art, the utility model has the following beneficial effects:

[0021] 1. The guide piece and the pipe are on the same axis, and the outer wall of the guide piece is parallel to the inner wall of the pipe. At this time, the first guide channel forms a circular channel, so that during the ventilation process, the flow of normal temperature air is close to the inner wall area of ​​the pipe, which can quickly and evenly cool the inner wall of the pipe. On the one hand, the cooling and shaping of the pipe is accelerated by air cooling, and the cooling pressure for the subsequent cooling device is reduced. On the other hand, it also avoids the occurrence of pipe sag;

[0022] 2. A plurality of air inlets may be provided on the circumferential wall of the guide member, and the number and density of the air inlets gradually increase from the front end to the rear end of the circumferential wall of the guide member. When the air enters the first guide channel, it will not all flow into the cavity of the guide member from the air inlet at the front end, but will continuously flow along the first guide channel and continuously enter the cavity of the guide member from each air inlet, thereby achieving the purpose of uniform and rapid cooling of the inner wall of the pipe;

[0023] 3. The front end of the guide member is provided with a guide cone surface. During the air extraction process, the guide cone surface can divert and guide the air extracted from the inner cavity of the pipe. The air enters the first guide channel along the guide cone surface, and then passes through the second guide channel and the air extraction channel in sequence before being extracted outwards.

[0024] 4. The guide piece passes through the inner cavity of the sizing sleeve. While the vacuum setting machine is vacuum cooling and setting the pipe in the sizing sleeve, the air cooling structure is used to cool the inner wall of the pipe synchronously, thereby increasing the cooling speed of the pipe and reducing the working pressure for the subsequent cooling process.

[0025] 5. An annular abutting oblique cylindrical surface is formed between the adjusting plate and the fixed plate, and the adjusting plate also has a guide cone surface. Due to the setting of the annular abutting oblique cylindrical surface and the guide cone surface, there is no area between the adjusting plate and the fixed plate that hinders the flow of the molten material during the process of adjusting the wall thickness of the pipe, thereby ensuring the smoothness of the flow of the molten material and further ensuring the stability of the pipe extrusion;

[0026] 6. The angle between the inclined cylindrical surface of the adjusting part and the guide cone surface is set to an acute angle. In this case, no matter whether the adjusting plate moves outward or inward, the angle between the guide cone surface of the adjusting part and the inner wall of the fixed plate is always an obtuse angle, so as to improve the smoothness of the melt material flow;

[0027] 7. An adjusting screw and a locking screw are provided between the adjusting part and the fixed plate. The adjusting screw is used to move the adjusting part. When the adjusting plate is adjusted to a preset position, the locking screw is used to lock the adjusting part, thereby achieving the purpose of adjusting the wall thickness of the pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a cross-sectional view of the air cooling structure and the mold body in the first embodiment of the utility model;

[0029] Figure 2 The utility model Figure 1 A partial enlarged view of the middle A;

[0030] Figure 3 It is a cross-sectional view of the air cooling structure and the mold body in the second embodiment of the present utility model.

[0031] In the figure, 100, guide member; 110, first guide channel; 120, exhaust channel; 130, air inlet; 140, bracket; 141, connector; 150, second guide channel; 160, sizing sleeve; 170, vacuum setting machine; 200, inner mold core; 300, outer mold plate; 310, fixing plate; 320, adjusting plate; 321, adjusting part; 322, matching part; 3221, annular abutting inclined cylindrical surface; 3222, guide cone surface; 330, adjusting screw; 340, locking screw; 341, locking block; 350, through hole; 351, avoidance groove; 400, melt flow channel. DETAILED DESCRIPTION

[0032] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical method of the present invention, but the present invention is not limited to these embodiments.

[0033] Embodiment 1

[0034] like Figure 1-2 As shown, the utility model provides an air cooling structure for plastic pipes, comprising:

[0035] The guide member 100 is arranged in the inner cavity of the pipe, and a first guide channel 110 is formed between the guide member 100 and the inner wall of the pipe. The first guide channel 110 is connected to an external exhaust fan (not shown in the figure) through an exhaust channel 120. The heat in the pipe is extracted outward through the first guide channel 110 and the exhaust channel 120 in sequence through the external exhaust fan.

[0036] Among them, the guide member 100 and the pipe are on the same axis, and the outer wall of the guide member 100 is parallel to the inner wall of the pipe. At this time, the first guide channel 110 forms a circular channel, thereby achieving a rapid and uniform cooling effect on the inner wall of the pipe during the exhaust process. On the one hand, air cooling accelerates the cooling and shaping of the pipe, reducing the cooling pressure for the subsequent cooling device, and on the other hand, it also avoids the occurrence of pipe sagging.

[0037] Preferably, the front end surface of the guide member 100 is set as a front guide cone surface. During the air extraction process, the front guide cone surface can divide and guide the air extracted from the inner cavity of the tube and evenly disperse it into the first guide channel 110;

[0038] Furthermore, a rear guide surface is provided on the rear end surface of the guide member 100 , and the air in the first guide channel 110 flows along the rear guide surface and enters the exhaust channel 120 , and then is exhausted outward along the exhaust channel 120 .

[0039] Embodiment 2

[0040] like Figure 3As shown, the difference between Example 2 and Example 1 is that, in Example 1, the air enters the first guide channel 110 after being diverted by the front guide cone, and then directly enters the exhaust channel 120 through the first guide channel 110 and is drawn out. In comparison, in Example 2, the air enters the first guide channel 110 after being diverted by the front guide cone, and then re-enters the exhaust channel 120 from the inside of the guide member 100 and is drawn out.

[0041] Specifically, in the second embodiment, the guide member 100 has a cavity inside, and a plurality of air inlets 130 are provided on the circumferential wall of the guide member 100 . The air flowing into the first guide channel 110 enters the cavity of the guide member 100 through the air inlets 130 .

[0042] The rear end of the guide member 100 is connected to the exhaust passage 120 , so that the air entering the cavity of the guide member 100 can be exhausted outward through the exhaust passage 120 .

[0043] That is to say, Embodiment 1 and Embodiment 2 provide two different air cooling structures, but both can achieve the purpose of rapid and uniform cooling of the inner wall of the pipe, reduce the cooling pressure for the subsequent cooling device, and on the other hand, avoid the occurrence of pipe sagging.

[0044] Preferably, the number and density of the air inlets 130 gradually increase from the front end to the rear end of the circumferential wall of the guide member 100. Therefore, when the air enters the first guide channel 110, not all of the air will flow into the cavity of the guide member 100 from the front air inlet 130, but will flow continuously along the first guide channel 110 and continuously enter the cavity of the guide member 100 from each air inlet 130, thereby achieving the purpose of uniform and rapid cooling of the inner wall of the tube.

[0045] In addition, it should be noted that the two air cooling structures provided in the first embodiment and the second embodiment can be used separately for cooling the inner wall of the pipe.

[0046] like Figure 1-3 As shown, the present application also provides a plastic pipe forming die, which has the air cooling structure of the plastic pipe in the above embodiment 1 or the air cooling structure of the plastic pipe in the above embodiment 2, wherein the forming die includes:

[0047] A die body, which extrudes the molten material into a tube and extrude it outward;

[0048] The exhaust channel 120 is opened at the core of the mold body, and the flow guide 100 is installed at the outlet end of the mold body.

[0049] Preferably, when the air cooling structure is set as the structure in the first embodiment, a bracket 140 needs to be installed at the air inlet end of the exhaust channel 120, and the bracket 140 is connected to the inner wall of the mold body. At the same time, the outlet end of the mold body and the bracket 140 are connected by a connecting plate to form an annular guide surface;

[0050] At the same time, the rear end of the guide member 100 is connected to the bracket 140 through the connecting member 141, and the guide member 100 is also connected and fixed to the connecting plate through a number of fasteners (not shown in the figure), wherein the rear guide surface of the guide member 100 cooperates with the annular guide surface to form a second guide channel 150, and the first guide channel 110 is connected to the exhaust channel 120 through the second guide channel 150.

[0051] When the air cooling structure is set as the structure in the second embodiment, it is only necessary to connect the rear end of the air guide member 100 to the air exhaust channel 120 .

[0052] Preferably, a sizing sleeve 160 is further included, which is close to the outlet end of the mold body. The pipe is extruded from the mold body and passes through the sizing sleeve 160. At the same time, the outside of the sizing sleeve 160 is also connected to a vacuum molding machine 170. The air in the sizing sleeve 160 is extracted by the vacuum molding machine 170, and the sizing sleeve 160 is placed in a vacuum state. At this time, the high-temperature pipe expands to abut against the inner wall of the sizing sleeve 160, and then the pipe is molded by cooling.

[0053] Preferably, the guide member 100 passes through the inner cavity of the sizing sleeve 160. While the vacuum shaping machine 170 performs vacuum cooling and shaping on the pipe in the sizing sleeve 160, the air cooling structure is used to synchronously cool the inner wall of the pipe to increase the cooling speed of the pipe, thereby reducing the working pressure for the subsequent cooling process.

[0054] Preferably, the mold body includes an inner mold core 200 and an outer mold plate 300, and a melt flow channel 400 for the molten material to flow is formed between the inner mold core 200 and the outer mold plate 300. During the process of the molten material flowing along the melt flow channel 400, it is continuously extruded and formed, and finally a high-temperature pipe is formed and extruded outward from the outlet end of the mold body.

[0055] Preferably, the outer mold plate 300 includes a fixed plate 310 and an adjusting plate 320 . The adjusting plate 320 is movably abutted against the fixed plate 310 . The movement of the adjusting plate 320 changes the space of the melt flow channel 400 to adjust the wall thickness of the pipe.

[0056] Specifically, the adjustment plate 320 in this embodiment includes an adjustment portion 321 and a matching portion 322 connected to each other. The matching portion 322 extends toward the direction of the fixed plate 310 and has an inclined cylindrical surface and a guide cone surface, wherein:

[0057] The inclined cylindrical surface of the matching part 322 cooperates with the adjustment plate 320 to form an annular abutting inclined cylindrical surface 3221, and the guide cone surface of the matching part 322 forms a guide cone surface 3222 of the molten material. The movement of the adjustment part 321 drives the matching part 322 to move along the annular abutting inclined cylindrical surface 3221, thereby changing the distance between the entire adjustment plate 320 and the inner mold core 200, thereby achieving the purpose of adjusting the wall thickness of the pipe.

[0058] It is worth mentioning here that, due to the setting of the annular abutting inclined cylindrical surface 3221 and the guide cone surface 3222, during the process of adjusting the wall thickness, there will be no area between the adjustment plate 320 and the fixed plate 310 that hinders the flow of the molten material, thereby ensuring the smoothness of the flow of the molten material and further ensuring the stability of the pipe extrusion.

[0059] In addition, the angle between the inclined cylindrical surface of the adjusting portion 321 and the guide cone surface is set to an acute angle. In this case, no matter whether the adjusting plate 320 moves outward or inward, the angle between the guide cone surface of the adjusting portion 321 and the inner wall of the fixed plate 310 is always an obtuse angle, so as to improve the smoothness of the flow of the melt material.

[0060] Preferably, an adjusting screw 330 and a locking screw 340 are provided between the adjusting portion 321 and the fixing plate 310 , and the adjusting portion 321 is moved by the adjusting screw 330 . When the adjusting plate 320 is adjusted to a preset position, the adjusting portion 321 is locked by the locking screw 340 .

[0061] Specifically, the adjusting screw 330 passes through the adjusting portion 321 and the two are connected by a thread. At the same time, the end of the adjusting screw 330 is always in contact with the fixing plate 310, and the fixing plate 310 is always in a fixed position. Therefore, by turning the adjusting screw 330, the adjusting portion 321 can be driven to move back and forth along the annular abutting inclined cylindrical surface 3221, thereby achieving the purpose of adjusting the wall thickness of the pipe.

[0062] Preferably, the adjusting portion 321 is provided with a through hole 350 , and an escape groove 351 is reserved at one end of the through hole 350 away from the fixing plate 310 .

[0063] Preferably, a locking block 341 is further included, and the locking screw 340 passes through the locking block 341 and the through hole 350 in sequence and is threadedly connected to the fixing plate 310, wherein the locking block 341 is located in the avoidance groove 351 and can press the adjustment plate 320, and as the adjustment plate 320 moves, the space of the avoidance groove 351 changes accordingly, and within the adjustment range of the adjustment plate 320, a gap is always left between the locking block 341 and the avoidance groove 351, ensuring that the locking block 341 can extend into the avoidance groove 351 and lock the adjustment part 321.

[0064] The technical means disclosed in the scheme of the utility model are not limited to the technical means disclosed by the above technical means, but also include technical solutions composed of any combination of the above technical features. The above is a specific implementation method of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

[0065] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0066] In addition, in the present invention, the descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A plastic pipe forming mold with an air cooling structure, characterized in that: The air cooling structure comprises: a flow guide, which is arranged in the inner cavity of the pipe, and a first flow guide channel is formed between the flow guide and the inner wall of the pipe, and the first flow guide channel is connected to an external exhaust fan through an exhaust channel, and the heat in the pipe is sequentially extracted out through the first flow guide channel and the exhaust channel by the external exhaust fan; Also included is a die body, which extrudes the molten material into a tube and extrude it outward; The exhaust channel is opened at the core of the mold body, and the guide member is installed at the outlet end of the mold body; The mold body includes an inner mold core and an outer mold plate, and a melt flow channel for the melt material to flow is formed between the inner mold core and the outer mold plate, wherein: The outer mold plate includes a fixed plate and an adjusting plate. The adjusting plate is movably abutted against the fixed plate. The movement of the adjusting plate changes the space of the melt flow channel to adjust the wall thickness of the pipe.

2. A plastic pipe forming mold according to claim 1, characterized in that: The guide member and the pipe are located on the same axis, and the outer circumferential wall of the guide member is parallel to the inner wall of the pipe, so that the first guide channel forms an annular channel.

3. A plastic pipe forming mold according to claim 2, characterized in that: The front end surface of the guide member is provided with a front guide cone surface, and the air flows through the front guide cone surface and enters the first guide channel.

4. A plastic pipe forming mold according to claim 3, characterized in that: The rear end surface of the guide member is provided with a rear guide surface, and the air in the first guide channel flows along the rear guide surface and enters the air exhaust channel.

5. A plastic pipe forming mold according to claim 3, characterized in that: The guide member has a cavity inside, and a plurality of air inlets are provided on the circumferential wall of the guide member. The air flowing into the first guide channel can enter the cavity of the guide member through each of the air inlets.

6. A plastic pipe forming mold according to claim 5, characterized in that: The rear end of the guide member is connected to the air extraction channel, and the air entering the cavity thereof is extracted outwards through the air extraction channel.

7. A plastic pipe forming mold according to claim 5, characterized in that: The number and density of the air inlets gradually increase from the front end to the rear end of the circumferential wall of the guide member.

8. A plastic pipe forming mold according to claim 1, characterized in that: It also includes a sizing sleeve and a vacuum shaping machine. The sizing sleeve is close to the outlet end of the mold body. The pipe passes through the sizing sleeve after being extruded from the mold body. The vacuum shaping machine is located outside the sizing sleeve and can perform vacuum shaping on the pipe in the sizing sleeve.

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