A device for extruding a pipe into a full circle
The core rod and ball combination design of the pipe extrusion rounding device, combined with the multi-stage cooling system and spray mechanism, solves the problem of ovality deviation during the pipe cooling process and realizes the production of high-roundness pipes.
Patent Information
- Application Number
- CN202510732933.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-04
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2045-06-04
AI Technical Summary
In the prior art, the ovality deviation of the pipe occurs due to the release of melt stress during the cooling process, making it difficult to produce highly round pipes.
The pipe extrusion and rounding device is used. Through the combined design of core rod and ball, the inner and outer diameters of the pipe are controlled with high precision. Combined with the multi-stage cooling system and spray mechanism, differential cooling of the inner and outer layers of the pipe and dynamic rounding are achieved.
The ovality of the tube is stably controlled within 0.03mm, high-roundness tubes are produced, the ovality deviation is reduced by more than 50%, and the inner and outer diameter accuracy and surface smoothness of the tube are ensured.
Smart Images
Figure CN120245369B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of pipe production, in particular to a pipe rounding extrusion device. Background Art
[0002] At present, when producing plastic pipes, a hot melt extruder is generally used to melt the raw materials, and then the pipe is extruded through an extrusion die head. The pipe is then cooled by a sizing sleeve and a cooling water trough to form a fixed shape of the pipe.
[0003] However, the sizing sleeve can only constrain the outer diameter of the pipe and cannot dynamically round the inner wall of the pipe. During the cooling process, the pipe is prone to ovality deviation due to the release of melt stress, making it difficult to produce a highly round pipe. Summary of the Invention
[0004] The purpose of the present invention is to provide a pipe extrusion rounding device, which can control the inner diameter and outer diameter of the pipe with high precision, reduce the ovality deviation of the pipe, and produce a high-roundness pipe.
[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:
[0006] The cam is connected to the outlet port of the extruder, and the cam is connected to the outlet port of the extruder by the cam. The cam is connected to the outlet port of the extruder by the cam. The cam is connected to the outlet port of the extruder by the cam.
[0007] Preferably, the pipe extrusion device further comprises a rotary joint, the connecting piece is connected to the rolling ball via the rotary joint, and the rolling ball can rotate relative to the connecting piece.
[0008] Preferably, the connecting member is a steel wire, a through hole is axially opened at the center of the mandrel, the steel wire passes through the through hole and is fixed in the through hole of the mandrel.
[0009] Preferably, the rolling ball is a Teflon rolling ball.
[0010] Preferably, the inner diameter of the tube is D, and the diameter of the ball is d, wherein 0.93≤d / D≤0.97.
[0011] Preferably, the pipe extrusion rounding device also includes a cooling water source, a plurality of cooling cavities are provided in the side wall of the cooling sizing sleeve along its axial direction, a plurality of water inlet interfaces and a plurality of water outlet interfaces are provided in the outer side of the cooling sizing sleeve along the axial direction, the plurality of water inlet interfaces are connected to the plurality of cooling cavities in a one-to-one correspondence, the plurality of water outlet interfaces are connected to the plurality of cooling cavities in a one-to-one correspondence, and the cooling water source is connected to the water inlet interface and the water outlet interface.
[0012] Preferably, the cooling and sizing sleeve comprises an outer sleeve and an inner sleeve, the inner sleeve is arranged in the outer sleeve, a plurality of cooling cavities are spaced apart along the axial direction of the cooling and sizing sleeve between the outer sleeve and the inner sleeve, the inner sleeve is provided with a water hole connecting the cooling cavity and the inner side of the inner sleeve, the upper end of the outer sleeve is provided with a plurality of water inlet interfaces along the axial direction thereof, and the lower end of the outer sleeve is provided with a plurality of water outlet interfaces along the axial direction thereof;
[0013] There are multiple cooling water sources, and the multiple cooling water sources are connected to the multiple cooling chambers in a one-to-one correspondence. There is a temperature difference in the cooling water in the multiple cooling water sources, and the temperature of the cooling water in the multiple cooling chambers in the cooling sizing sleeve decreases step by step from one end close to the die head to one end away from the die head.
[0014] Preferably, three cooling cavities are provided in the cooling and sizing sleeve, and the temperatures of the cooling water flowing into the three cooling cavities are 60° C., 40° C. and 20° C. respectively.
[0015] Preferably, the pipe extrusion and rounding device further comprises a cooling water trough and a spray mechanism, wherein the cooling water trough and the spray mechanism are both arranged opposite to and spaced apart from the end of the cooling and sizing sleeve away from the die head, and the spray mechanism is located above the cooling water trough;
[0016] Wherein, the temperature of the cooling water in the cooling water tank is 20-25°C, and the temperature of the cooling water in the spray mechanism is 10-15°C.
[0017] Preferably, the rolling ball is located in the area where the pipe is immersed in the cooling water tank.
[0018] Compared with the prior art, the pipe rounding device according to the embodiment of the present invention has the following advantages:
[0019] In the present invention, the extruder melts the raw material and injects it into the accommodating cavity of the die head, and then the raw material in the molten state flows to the extrusion hole of the die head. Since one end of the core rod is located at the extrusion hole, and the core rod is coaxially arranged with the extrusion hole, and the outer diameter of the core rod is smaller than the inner diameter of the extrusion hole, the molten raw material is extruded from the extrusion hole to form a tube. Then the tube enters the cooling and sizing sleeve. The cooling and sizing sleeve can control the outer diameter of the tube and cool and shape the tube at the same time. Then, the tube coming out of the cooling and sizing sleeve is provided with the rolling ball. Under the action of the rolling ball, the inside of the tube can be rounded to control the inner diameter of the tube. Therefore, the present invention realizes high-precision control of the inner and outer diameters of the tube by rounding the inside and outside of the tube, thereby stabilizing the ovality of the tube within 0.03 mm, making the ovality deviation of the produced tube low, and finally producing a high-roundness tube. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 1 is a schematic diagram of the overall structure of an embodiment of the present invention;
[0021] Figure 2 yes Figure 1 A magnified view of point A in the figure;
[0022] Figure 3 yes Figure 1 Enlarged view of point B in .
[0023] In the figure, 100, pipe; 1, die head; 2, cooling sizing sleeve; 3, rolling ball; 4, connecting piece; 5, cooling water tank; 6, spray mechanism. DETAILED DESCRIPTION
[0024] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.
[0025] In the description of the present invention, it should be understood that the term "comprising" as used in the present specification refers to the presence of the stated features, integers, steps, operations, parts and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, parts / components, components and / or groups thereof. It should be understood that when we refer to a part / component as being "connected" to another part / component, it can be directly connected to the other part / component, or there can be intermediate parts / components. The term "and / or" as used herein includes all or any one and all combinations of one or more of the associated listed items.
[0026] like Figures 1 to 3As shown, the present invention relates to a pipe extrusion rounding device, comprising an extruder, a die head 1, a mandrel, a cooling sizing sleeve 2, a rolling ball 3 and a connecting piece 4, wherein the die head 1 is provided with an accommodating cavity, one end of the die head 1 is connected to the output port of the extruder, and the other end of the die head 1 is provided with an extrusion hole connected to the accommodating cavity, the mandrel is located in the accommodating cavity, one end of the mandrel is connected to the die head 1, and the other end of the mandrel extends to the extrusion hole, and the mandrel and the extrusion hole are coaxially arranged. The cooling and sizing sleeve 2 is opposite to the extrusion hole and is arranged at intervals. The cooling and sizing sleeve 2 is used for the pipe 100 to enter so as to control the outer diameter of the pipe 100. The ball 3 is connected to the mandrel through the connector 4. One end of the connector 4 is connected to the ball 3. The other end of the connector 4 passes through the cooling and sizing sleeve 2 and is connected to the end of the mandrel close to the cooling and sizing sleeve 2. The ball 3 is used to enter the interior of the pipe 100 to control the inner diameter of the pipe 100.
[0027] In the present invention, the extruder melts the raw material and injects it into the accommodating cavity of the die head 1. Then, the raw material in the molten state flows to the extrusion hole of the die head 1. Since one end of the mandrel is located at the extrusion hole, and the mandrel is coaxially arranged with the extrusion hole, and the outer diameter of the mandrel is smaller than the inner diameter of the extrusion hole, the molten raw material is extruded from the extrusion hole to form a tube 100. Then, the tube 100 enters the cooling and sizing sleeve 2. The outer diameter of the tube 100 can be controlled by the cooling and sizing sleeve 2. The pipe 100 is cooled and shaped. Then, the ball 3 is provided inside the pipe 100 coming out of the cooling and sizing sleeve 2. Under the action of the ball 3, the inside of the pipe 100 can be rounded to control the inner diameter of the pipe 100. Therefore, the present invention achieves high-precision control of the inner and outer diameters of the pipe 100 by rounding the inside and outside of the pipe 100, thereby stabilizing the ovality of the pipe 100 within 0.03 mm, making the ovality deviation of the produced pipe 100 low, and finally producing a highly round pipe 100.
[0028] In this embodiment, the tube rounding device further includes a rotary joint, and the connecting member 4 is connected to the rolling ball 3 via the rotary joint, and the rolling ball 3 can rotate relative to the connecting member 4.
[0029] That is, through the setting of the rotary joint, the ball 3 can rotate freely, so that during the transportation of the pipe 100, the ball 3 continues to roll on the inner wall of the pipe 100, thereby dynamically correcting the ovality of the inner diameter of the pipe 100 and achieving high-precision control of the inner diameter of the pipe 100.
[0030] Preferably, the ball 3 is a Teflon ball 3 , the friction coefficient of the Teflon ball 3 is less than 0.05, the temperature resistance range is -200° C.-260° C., and it has self-lubricating and maintenance-free properties.
[0031] Therefore, the Teflon ball 3 has a low friction coefficient, so that the ball 3 will not scratch the inner wall of the tube 100 when rolling in the tube 100. Moreover, since the temperature of the tube 100 is relatively high after being extruded by the die head 1, the Teflon ball 3 has high temperature resistance to ensure the service life of the ball 3. In addition, the Teflon ball 3 has self-lubricating and maintenance-free characteristics, so that the inner diameter of the tube 100 can be controlled with high precision, maintenance is reduced, and high-precision production of the tube 100 is facilitated.
[0032] In this embodiment, grooves are evenly distributed on the surface of the ball 3 to enhance the rolling uniformity of the ball 3 and improve the full-circle effect.
[0033] In this embodiment, the connecting member 4 is a steel wire. A through hole is axially opened at the center of the core rod. The steel wire passes through the through hole and is fixed in the through hole of the core rod.
[0034] Since the connecting member 4 is a steel wire, it has strong structural strength and high temperature resistance, so it can stably pull the ball 3, ensuring that the ball 3 can be stably rounded on the inner side of the pipe 100.
[0035] Specifically, a mounting hole is provided inside the die head 1, the inner wall of the mounting hole is provided with an internal thread, and a clip is also provided in the mounting hole. The end of the mandrel away from the cooling and sizing sleeve 2 extends into the mounting hole and is threadedly connected to the mounting hole, thereby realizing a threaded connection between the mandrel and the die head 1. The steel wire passes through the through hole to the end of the mandrel away from the cooling and sizing sleeve 2, and is connected to the clip to fix the end of the steel wire away from the ball 3 to the clip.
[0036] In other embodiments, a threaded hole is opened on the outside of the core rod, and the threaded hole extends into the through hole of the core rod. A fixing bolt is threadedly connected to the threaded hole. When the fixing bolt is tightened, the fixing bolt presses against the steel wire in the through hole to fix the steel wire.
[0037] In this embodiment, the inner diameter of the tube 100 is D, and the diameter of the ball 3 is d, wherein 0.93≤d / D≤0.97, and the value of d / D can be 0.93, 0.94, 0.95, 0.94 or 0.97. Preferably, d / D=0.95.
[0038] That is, the diameter of the ball 3 is slightly smaller than the inner diameter of the tube 100 , so that the ball 3 can roll smoothly in the tube 100 , thereby rounding the inside of the tube 100 and accurately controlling the inner diameter of the tube 100 .
[0039] In this embodiment, the pipe extrusion rounding device also includes a cooling water source, and a plurality of cooling cavities are provided in the side wall of the cooling sizing sleeve 2 along its axial direction, and a plurality of water inlet interfaces and a plurality of water outlet interfaces are provided on the outer side of the cooling sizing sleeve 2 along the axial direction. The plurality of water inlet interfaces are connected to the plurality of cooling cavities in a one-to-one correspondence, and the plurality of water outlet interfaces are connected to the plurality of cooling cavities in a one-to-one correspondence, and the cooling water source is connected to the water inlet interface and the water outlet interface.
[0040] That is, the cooling water source is connected to the water inlet interface and the water outlet interface, so that the cooling water can circulate between the cooling water source and the cooling chamber, so that the temperature in the cooling chamber is constant, so as to achieve a cooling effect when the pipe 100 passes through the cooling sizing sleeve 2, thereby controlling the outer diameter of the pipe 100 and preliminarily shaping the outer side of the pipe 100.
[0041] Preferably, the cooling and sizing sleeve 2 includes an outer sleeve and an inner sleeve, the inner sleeve being arranged inside the outer sleeve, a plurality of cooling cavities being spaced apart along the axial direction of the cooling and sizing sleeve 2 between the outer sleeve and the inner sleeve, the inner sleeve being provided with water holes connecting the cooling cavities and the inner side of the inner sleeve, and the inner sleeve being provided with a plurality of water holes uniformly distributed along the circumference in the region corresponding to the cooling cavities, the upper end of the outer sleeve being provided with a plurality of water inlet interfaces along its axial direction, and the lower end of the outer sleeve being provided with a plurality of water outlet interfaces along its axial direction. There are a plurality of cooling water sources, and the plurality of cooling water sources are connected to the plurality of cooling cavities in a one-to-one correspondence. There is a temperature difference between the cooling water in the plurality of cooling water sources, and the temperature of the cooling water in the plurality of cooling cavities in the cooling and sizing sleeve 2 decreases step by step from the end close to the die head 1 to the end away from the die head 1.
[0042] Therefore, when multiple cooling water sources supply cooling water into multiple cooling cavities, the cooling water can also enter the inner side of the inner sleeve through the water hole to cool the pipe 100 entering the inner sleeve, and then the temperature of the multiple cooling waters decreases step by step, so the pipe 100 is also cooled step by step, thereby gradually reducing the internal stress of the pipe 100, preventing the pipe 100 from cracking and deformation, and ensuring the smooth production of the pipe 100.
[0043] Specifically, the cooling sizing sleeve 2 is provided with three cooling cavities along its axial direction, and the temperatures of the cooling water flowing into the three cooling cavities are 60°C, 40°C and 20°C respectively, thereby cooling the pipe 100 step by step to ensure the smooth production of the pipe 100.
[0044] It should be noted that the cooling and sizing sleeve 2 of the present invention can be a cooling and sizing sleeve currently available on the market, such as a sizing sleeve machine and sizing device disclosed in application number CN202310510473.5.
[0045] In this embodiment, the pipe extrusion and rounding device further includes a cooling water trough 5 and a spray mechanism 6. The cooling water trough 5 and the spray mechanism 6 are both arranged opposite and spaced apart from the end of the cooling and sizing sleeve 2 away from the die head 1, and the spray mechanism 6 is located above the cooling water trough 5. The temperature of the cooling water in the cooling water trough 5 is 20-25°C, and the temperature of the cooling water in the spray mechanism 6 is 10-15°C.
[0046] Specifically, after the pipe 100 is transferred out of the cooling and sizing sleeve 2, it moves toward the cooling water tank 5. Before the pipe 100 is immersed in the cooling water in the cooling water tank 5, since the spray mechanism 6 is arranged above the cooling water tank 5, the spray mechanism 6 is also located above the pipe 100. Then, when the spray mechanism 6 sprays cooling water with a temperature of 10-15°C downward, the cooling water of 10-15°C can flush the pipe downward, thereby quickly cooling and shaping the outer layer of the pipe 100. Then, after the pipe 100 is immersed in the cooling water in the cooling water tank 5, the constant temperature water of 20-25°C in the cooling water tank 5 can allow the inner layer of the pipe 100 to release thermal stress, so as to smoothly produce the pipe 100.
[0047] It should be emphasized that the present invention integrates the cooling and sizing sleeve 2, the cooling water tank 5 and the spray mechanism 6, and connects three cooling water sources through the cooling and sizing sleeve 2, so that the cooling and sizing sleeve 2 can realize segmented cooling of the pipe 100 from 60°C → 40°C → 20°C, and then combines the cooling water tank 5 and the spray mechanism 6 to realize dual-mode cooling of the pipe by spraying and immersion, thereby achieving differential cooling of the inner and outer layers of the pipe 100, thereby significantly reducing the ovality deviation of the pipe 100 caused by melt stress. Compared with traditional single cooling, the ovality deviation of the pipe 100 is reduced by more than 50%.
[0048] In some embodiments, the ball 3 is located in the area where the pipe 100 is immersed in the cooling water tank 5, so that during the process of the inner layer of the pipe 100 being shaped in the cooling water tank 5, the ball 3 rounds the inner layer of the pipe 100 to accurately control the inner diameter of the pipe 100.
[0049] It should be noted that the position of the ball 3 can be adjusted. Specifically, the position of the ball 3 can be adjusted by adjusting the length of the steel wire. The position of the ball 3 is adjusted according to the ovality and cooling degree of the pipe 100, so as to accurately control the inner diameter of the pipe 100.
[0050] In order to further illustrate the effect of the pipe extrusion device of the present invention, the present invention lists Example 1 and Example 2 for illustration.
[0051] Example 1:
[0052] It is suitable for producing PVC pipes with a diameter of 50 mm. The diameter of the ball 3 is 47.5 mm. The segmented temperatures of the cooling sizing sleeve 2 are 60° C., 40° C. and 20° C. respectively.
[0053] Finally, the produced tube 100 was tested and the ovality of the tube 100 was 0.03 mm, and the surface finish Ra of the tube 100 was ≤ 1 μm.
[0054] Example 2:
[0055] It is suitable for producing HDPE pipes with a diameter of 200 mm. The diameter of the rolling ball 3 is 190 mm, and the temperature of the cooling water in the cooling water tank 5 is 22°C ± 0.5°C.
[0056] Finally, after testing, the produced tube 100 has an ovality of 0.03 mm and an axial deviation of 0.1 mm or less.
[0057] Example 3:
[0058] It is suitable for producing PPR pipes with a diameter of 32 mm. The diameter of the ball 3 is 30.4 mm. The segmented temperatures of the cooling sizing sleeve 2 are 80°C → 50°C → 20°C in sequence to adapt to the higher melt temperature of PPR.
[0059] Finally, the produced tube 100 was tested and the ovality of the tube 100 was 0.025 mm, and the axial deviation of the tube 100 was less than or equal to 0.08 mm.
[0060] For Example 3, by adjusting the temperature gradient of the cooling sizing sleeve 2, the compatibility of the pipe extrusion rounding device with high-temperature materials (PPR melting temperature 260°C) was verified, which can highlight the flexibility of the cooling system design of the present invention.
[0061] Example 4:
[0062] It is suitable for producing PE-X pipes with a diameter of 16 mm. The diameter of the rolling ball 3 is 15.2 mm, and the water temperature in the cooling water tank 5 is 18°C.
[0063] Finally, the produced pipe 100 was tested and the surface finish of the pipe was Ra≤0.8 μm.
[0064] In Example 4, the high hardness of cross-linked PE-X pipes is exploited by utilizing the low-friction properties of Teflon balls 3 to prevent scratches on the inner wall of pipe 100, thus filling a technological gap in high-precision rounding of cross-linked pipes. Furthermore, this invention demonstrates the ability to round small-diameter pipes (<20mm), overcoming the limitations of conventional devices that are limited to medium- and large-diameter pipes.
[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.
Claims
1. A device for extruding a pipe into a round shape, characterized in that: The cam is connected to the extruder through a channel that is formed on the outer surface of the cam and the channel is connected to the channel inserting means. The cam is connected to the channel inserting means for extruding said cam and the channel inserting means for extruding said cam is used to connect the cam and the channel inserting means for extruding said cam. It also includes a rotary joint, the connecting member is connected to the rolling ball through the rotary joint, and the rolling ball can rotate relative to the connecting member; It also includes a cooling water source, a plurality of cooling cavities are provided in the side wall of the cooling sizing sleeve along the axial direction thereof, a plurality of water inlet interfaces and a plurality of water outlet interfaces are provided in the outer side of the cooling sizing sleeve along the axial direction thereof, the plurality of water inlet interfaces are connected to the plurality of cooling cavities in a one-to-one correspondence, the plurality of water outlet interfaces are connected to the plurality of cooling cavities in a one-to-one correspondence, and the cooling water source is connected to the water inlet interfaces and the water outlet interfaces; The cooling and sizing sleeve comprises an outer sleeve and an inner sleeve, the inner sleeve is arranged in the outer sleeve, a plurality of cooling cavities are spaced apart along the axial direction of the cooling and sizing sleeve between the outer sleeve and the inner sleeve, the inner sleeve is provided with a water hole connecting the cooling cavity and the inner side of the inner sleeve, the upper end of the outer sleeve is provided with a plurality of water inlet interfaces along the axial direction thereof, and the lower end of the outer sleeve is provided with a plurality of water outlet interfaces along the axial direction thereof; There are multiple cooling water sources, and the multiple cooling water sources are connected to the multiple cooling chambers in a one-to-one correspondence. There is a temperature difference in the cooling water in the multiple cooling water sources, and the temperature of the cooling water in the multiple cooling chambers in the cooling sizing sleeve decreases step by step from one end close to the die head to one end away from the die head.
2. The pipe extrusion rounding device according to claim 1, characterized in that: The connecting piece is a steel wire, a through hole is opened in the center of the core rod along the axial direction, the steel wire passes through the through hole and is fixed in the through hole of the core rod.
3. The pipe extrusion rounding device according to claim 1, characterized in that: The rolling ball is a Teflon rolling ball.
4. The pipe extrusion rounding device according to claim 1, characterized in that: The inner diameter of the tube is D, and the diameter of the ball is d, wherein 0.93≤d / D≤0.
97.
5. The pipe extrusion rounding device according to claim 1, characterized in that: The cooling and sizing sleeve is provided with three cooling cavities, and the temperatures of the cooling water flowing into the three cooling cavities are 60° C., 40° C. and 20° C. respectively.
6. The pipe extrusion rounding device according to claim 5, characterized in that: It also includes a cooling water trough and a spray mechanism, wherein the cooling water trough and the spray mechanism are both opposite to and spaced from the end of the cooling and sizing sleeve away from the die head, and the spray mechanism is located above the cooling water trough; Wherein, the temperature of the cooling water in the cooling water tank is 20-25°C, and the temperature of the cooling water in the spray mechanism is 10-15°C.
7. The pipe extrusion rounding device according to claim 6, characterized in that: The rolling ball is located in the area where the pipe is immersed in the cooling water tank.