A thin-walled multi-stage conical surface transition reducing pipe made of oxygen-free copper and a drawing method thereof

Abstract

The application relates to an oxygen-free copper thin-wall multi-stage conical surface transition variable-diameter pipe and a drawing processing method thereof, and relates to the technical field of plastic forming processing of oxygen-free copper thin-wall pipes. The application comprises an oxygen-free copper thin-wall multi-stage conical surface transition variable-diameter pipe and an oxygen-free copper thin-wall multi-stage conical surface transition variable-diameter pipe drawing processing method. The application has the advantages that a single conical surface transition section is separately drawn during processing, and each pipe is butt-welded and fixed through the conical surface transition section. Compared with integrated forming processing, the processing method does not need to design a complicated integrated forming die, does not need to control the synchronism of multi-stage sizes, is simpler in processing technology, effectively reduces processing difficulty and die cost, and meanwhile, during the drawing process, lubricating oil is poured into the sponge block through the oil injection pipe, the sponge block can uniformly wipe and lubricate the outer wall of the pipe during drawing, the friction between the pipe wall and the die is reduced, drawing scratches and drawing injuries and other defects during drawing are effectively avoided, and the surface quality of the pipe fitting is improved.

Description

Technical Field

[0001] This invention relates to the field of plastic forming technology for oxygen-free copper thin-walled tubes, and in particular to an oxygen-free copper thin-walled multi-stage conical transition variable diameter tube and its drawing process. Background Technology

[0002] Currently, oxygen-free copper thin-walled reducers are widely used in industrial applications such as heat exchange, connection, flow guidance and precision assembly due to their good thermal and electrical conductivity. These applications typically require the reducer to form multiple different outer diameter segments along the axial direction on the same tube body, and adjacent outer diameter segments need to form a stable and high-precision conical transition segment.

[0003] In view of the above-mentioned technologies, an oxygen-free copper thin-walled multi-stage tapered transition reducer tube and its drawing process are provided. Summary of the Invention

[0004] The purpose of this application is to provide an oxygen-free copper thin-walled multi-stage tapered transition tube and its drawing process, in order to solve the problem of forming multiple different outer diameter segments along the axial direction on the same tube body, and the need to form a tapered transition segment with stable morphology and high precision between adjacent outer diameter segments.

[0005] This application provides a technical solution for an oxygen-free copper thin-walled multi-stage tapered transition reducer tube: A thin-walled, oxygen-free copper multi-stage tapered transition reducer tube includes a multi-stage tapered tube, wherein the multi-stage tapered tube includes a main tube, a first outer diameter section and a second outer diameter section, and a tapered transition section is fixedly provided on one side of the main tube, the first outer diameter section and the second outer diameter section. The second outer diameter section is fixedly connected to the tapered transition section of the first outer diameter section, and the first outer diameter section is fixedly connected to the tapered transition section of the main tube. By adopting the above technical solution and using a conical transition structure, multiple different outer diameter sections can be formed along the axial direction on the same pipe fitting, which can meet the needs of multi-specification pipeline connection. The pipe fittings are smoothly transitioned through the conical transition section, reducing stress concentration caused by sudden changes in pipe diameter.

[0006] Preferably, the outer diameter of the conical transition section is consistent with the outer diameter of the connecting pipe to which it is fixedly connected; By adopting the above technical solution, the outer diameter of the conical transition section and the adjacent outer diameter section can be smoothly connected, which facilitates the alignment of the pipe fittings with the external pipeline and makes the assembly smoother.

[0007] A drawing process for an oxygen-free copper thin-walled multi-stage tapered transition reducer tube, applicable to the aforementioned oxygen-free copper thin-walled multi-stage tapered transition reducer tube, includes the following steps: S1: The front end of the mother tube is sharpened. During drawing, one end of the mother tube needs to pass through the inner hole formed after the lower and upper molds are fixed. The outer diameter of the tip of the mother tube needs to be made smaller than the inner hole so that one end of the mother tube can pass through the inner hole and meet the mold passing conditions. S2: Once one end of the mother tube is inserted into the inner hole, the pulling operation can be prepared. Place the core head inside the mother tube to be pulled, insert the tip of the mother tube into the inner hole, start the hydraulic cylinder, and the hydraulic cylinder pushes the mother tube forward through the push plate fixedly connected to the output end, so that the tip of the mother tube extends out of the inner hole, making it convenient for the traction device to clamp and pull the extended area. S3: During the drawing process, lubricating oil is poured into the sponge block located between the first and second annular blocks through the oil injection pipe. During the drawing process, the outer wall of the pipe can be wiped with lubricating oil to reduce the friction during the drawing process. S4: During the drawing process, under the action of traction force, the mother tube passes through the inner hole with the support of the mandrel. The tapered structure on one side of the inner hole, together with the mandrel, shrinks the outer diameter and forms a tapered transition section. The fixing of the upper and lower molds is removed, and the mother tube with the tapered transition section is taken out. The sponge block fitted on the outer wall of the mother tube is also removed. Through the tapered transition section, it can be connected to pipes with different outer diameter ends, so that multiple sections with different outer radii can be formed along the axial direction on the same pipe body. At the same time, the mandrel and the tapered inner hole are used to stabilize the outer diameter and wall thickness of the pipe after drawing. S5: Perform end trimming and cleaning on the drawn multi-stage reducing pipe; By adopting the above technical solution, this processing method differs from the method of forming multiple segments with different outer radii along the axial direction on the same integrally formed tube. Instead, it adopts individual processing. By using a tapered structure on one side of the inner hole of the mother tube to shrink the outer diameter and form a tapered transition section, the connection between the upper and lower molds is eliminated, and the first and second annular blocks are separated. The mother tube with the tapered transition section can be removed, and the sponge block fitted on the outer wall of the mother tube is removed. By using individual drawing to create a single tapered transition section during processing, the connecting pipes are welded and fixed together through the tapered transition section. Compared with integral forming, this processing method does not require the design of complex integral forming molds, nor does it require the control of multi-level dimensional synchronization. The processing technology is simpler, effectively reducing the processing difficulty and mold cost. At the same time, during the drawing process, lubricating oil is poured into the sponge block through the oil injection pipe. The sponge block can evenly wipe and lubricate the outer wall of the pipe during drawing, reducing the friction between the pipe wall and the mold, effectively avoiding defects such as scratches and pulls during drawing, and improving the surface quality of the pipe fittings.

[0008] Preferably, the lower mold has two locating pins nested inside the two locating holes, and the upper mold has mounting holes corresponding to the locating pins at the bottom. The lower mold and the upper mold are fixed together by four first bolts that pass through the upper mold, extend into the lower mold, and are threadedly connected to it. By adopting the above technical solution, the upper mold and the lower mold are positioned by a positioning pin and fastened by a first bolt. This assembly structure allows the upper mold and the lower mold to be separated, making it convenient to remove the drawn tube.

[0009] Preferably, a cap is fitted onto the outer wall of the end of the oil injection pipe that extends out of the upper mold; By adopting the above technical solution, the oil inlet of the oil injection pipe can be sealed before adding lubricant to prevent dust and impurities from entering the oil injection pipe, thus avoiding contamination of the lubricating oil and reducing the evaporation of the lubricating oil.

[0010] Preferably, the first annular block is fixed by a second bolt passing through the first annular block and being threadedly connected to the lower mold; By adopting the above technical solution, the first annular block can be disassembled, and the detachable structure facilitates the replacement and maintenance of the sponge block.

[0011] Preferably, the second annular block is fixed by two third bolts passing through the second annular block and threadedly connected to the upper mold; By adopting the above technical solution and cooperating with the first annular block, a stable lubrication cavity is formed.

[0012] Preferably, a fixing plate is fixedly provided at the end of the hydraulic cylinder away from the push plate, and the fixing plate is fixedly connected to the base; By adopting the above technical solution, the hydraulic cylinder is installed securely, the thrust output is stable, and the push plate smoothly pushes the main tube forward, ensuring stability during the die-cutting process. Beneficial effects

[0013] In summary, this application includes at least one of the following beneficial technical effects: This invention provides an oxygen-free copper thin-walled multi-stage conical transition reducer tube and its drawing process. By changing the processing method, this method differs from the method of forming multiple segments with different outer radii along the axial direction on a single integrally formed tube. Instead, it employs individual processing. The outer diameter of one end of the mother tube is reduced by a conical structure on one side of the inner hole, in conjunction with a mandrel, to form a conical transition segment. Then, the connection between the upper and lower molds is eliminated, and the first and second annular blocks are separated, allowing the mother tube with the conical transition segment to be removed. Finally, the sponge block fitted onto the outer wall of the mother tube is removed. During processing... A single conical transition section is fabricated by drawing each pipe individually, and then the pipes are welded together and fixed through the conical transition section. Compared with one-piece molding, this processing method does not require the design of a complex one-piece molding mold or the control of multi-level dimensional synchronization. The processing technology is simpler, effectively reducing the processing difficulty and mold cost. At the same time, during the drawing process, lubricating oil is poured into the sponge block through the oil injection pipe. The sponge block can evenly wipe and lubricate the outer wall of the pipe during the drawing process, reducing the friction between the pipe wall and the mold, effectively avoiding defects such as scratches and pulls during drawing, and improving the surface quality of the pipe fittings. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the multi-stage tapered tube connection structure of the present invention; Figure 2 This is a schematic diagram of the multi-stage tapered tube pull-out installation structure of the present invention; Figure 3 This is a cross-sectional view of the present invention; Figure 4 This is a schematic diagram of the exploded structure of the molding die of the present invention.

[0015] Among them, 1. Multi-stage conical tube; 101. Main tube; 102. First outer diameter section; 103. Second outer diameter section; 104. Conical transition section; 2. Lower mold; 3. Upper mold; 4. First bolt; 5. Second bolt; 6. First annular block; 7. Third bolt; 8. Second annular block; 9. Oil injection pipe; 10. Cap; 11. Positioning pin; 12. Sponge block; 13. Core head; 14. Fixing plate; 15. Hydraulic cylinder; 16. Push plate. Detailed Implementation

[0016] The following is in conjunction with the appendix Figure 1 - Appendix Figure 4 This application will be described in further detail below.

[0017] Example 1: A thin-walled, multi-stage tapered transition reducer tube made of oxygen-free copper, referring to... Figure 1The system includes a multi-stage conical pipe 1, which comprises a main pipe 101, a first outer diameter section 102, and a second outer diameter section 103. A conical transition section 104 is fixedly provided on one side of the main pipe 101, the first outer diameter section 102, and the second outer diameter section 103. The second outer diameter section 103 is fixedly connected to the conical transition section 104 of the first outer diameter section 102. The first outer diameter section 102 is also fixedly connected to the conical transition section 104 of the main pipe 101. This conical transition structure allows for the formation of multiple different outer diameter sections along the axial direction on the same pipe fitting, meeting the requirements for connecting multiple specifications of pipelines. The pipe fittings smoothly transition through the conical transition section 104, reducing stress concentration caused by sudden changes in pipe diameter. The outer diameter of the conical transition section 104 is consistent with the outer diameter of the connecting pipe to which it is fixedly connected, ensuring a smooth connection between the outer diameter of the conical transition section 104 and adjacent outer diameter sections. This facilitates alignment of the pipe fitting with external pipelines and makes assembly smoother.

[0018] Example 2: A drawing method for oxygen-free copper thin-walled multi-stage tapered transition tube, referring to... Figure 1 , Figure 2 , Figure 3 and Figure 4 The method applied to the aforementioned oxygen-free copper thin-walled multi-stage tapered transition reducer tube includes the following steps: S1: The front end of the mother tube 101 is sharpened. During the drawing process, one end of the mother tube 101 needs to pass through the inner hole formed after the lower mold 2 and the upper mold 3 are fixed. The outer diameter of the tip of the mother tube 101 needs to be made smaller than the inner hole so that one end of the mother tube 101 can pass through the inner hole and meet the mold passing conditions. S2: Once one end of the mother tube 101 is inserted into the inner hole, the pulling operation can be prepared. Place the core 13 inside the mother tube 101 to be pulled, insert the tip of the mother tube 101 into the inner hole, start the hydraulic cylinder 15, and the hydraulic cylinder 15 pushes the mother tube 101 forward through the push plate 16 fixedly connected to the output end, so that the tip of the mother tube 101 extends out of the inner hole, making it convenient for the traction device to clamp and pull the extended area. S3: During the drawing process, lubricating oil is poured into the sponge block 12 located between the first annular block 6 and the second annular block 8 through the oil injection pipe 9. During the drawing process, the outer wall of the pipe can be wiped with lubricating oil to reduce the friction during the drawing process. S4: During the drawing process, under the action of traction force, the mother tube 101 is supported by the mandrel 13 and passes through the inner hole. The tapered structure on one side of the inner hole cooperates with the mandrel 13 to shrink the outer diameter and form a tapered transition section 104. The fixing of the upper and lower molds is removed, and the mother tube 101 that has been drawn and formed into the tapered transition section 104 is taken out. The sponge block 12 fitted on the outer wall of the mother tube 101 is also removed. The tapered transition section 104 can be connected to pipes with different outer diameter ends, so that multiple different outer radius sections are formed along the axial direction on the same pipe body. At the same time, the mandrel 13 and the tapered inner hole are used to stabilize the outer diameter and wall thickness of the pipe after drawing. S5: Perform end trimming and cleaning on the multi-stage reducing pipe after drawing.

[0019] The lower mold 2 has two locating pins 11 nested inside two locating holes. The bottom of the upper mold 3 has mounting holes corresponding to the locating pins 11. The lower mold 2 and the upper mold 3 are fixed together by four first bolts 4 that pass through the upper mold 3, extend into the lower mold 2, and are threaded together. The upper mold 3 and the lower mold 2 are positioned by the locating pins 11 and secured by the first bolts 4. This assembly structure allows the upper mold 3 and the lower mold 2 to be disassembled for easy removal of the drawn tube. The end of the oil injection pipe 9 extending out of the upper mold 3 is fitted with a cap 10. Before adding lubricant, the oil injection port of the oil injection pipe 9 is sealed to prevent dust and impurities from entering the oil injection pipe 9 and to avoid contamination. The lubricating oil is applied to the mold, which also reduces the evaporation of the lubricating oil. The first annular block 6 is fixed by the second bolt 5 passing through the first annular block 6 and threadedly connected to the lower mold 2. The first annular block 6 can be disassembled, and the detachable structure facilitates replacement and maintenance of the sponge block 12. The second annular block 8 is fixed by the second bolt 7 passing through the second annular block 8 and threadedly connected to the upper mold 3. It cooperates with the first annular block 6 to form a stable lubrication cavity. A fixing plate 14 is fixedly installed at the end of the hydraulic cylinder 15 away from the push plate 16. The fixing plate 14 is fixedly connected to the base. The hydraulic cylinder 15 is installed firmly and the thrust output is stable, ensuring that the push plate 16 smoothly pushes the mother tube 101 forward and ensuring stability during the mold-passing process.

[0020] The beneficial effects described above are as follows: By changing the processing method, which differs from forming multiple segments with different outer radii along the axial direction on the same integrally molded tube, a separate processing method is adopted. By using a tapered structure on one side of the inner hole of the mother tube 101 to shrink the outer diameter and form a tapered transition section 104, the connection between the upper mold 3 and the lower mold 2 is removed, and the first annular block 6 and the second annular block 8 are separated. The mother tube 101 with the tapered transition section 104 can be taken out. Then, the sponge block 12 fitted on the outer wall of the mother tube 101 is removed. By using a separate processing method during processing, the mother tube 101 with the tapered transition section 104 can be removed. A single conical transition section 104 is drawn to form the pipe fittings. The pipe fittings are then welded together and fixed through the conical transition section 104. Compared with one-piece molding, this processing method does not require the design of a complex one-piece molding mold or the control of multi-level dimensional synchronization. The processing technology is simpler, effectively reducing the processing difficulty and mold cost. At the same time, during the drawing process, lubricating oil is poured into the sponge block 12 through the oil injection pipe 9. The sponge block 12 can evenly wipe and lubricate the outer wall of the pipe during the drawing process, reducing the friction between the pipe wall and the mold, effectively avoiding defects such as scratches and pulls during the drawing process, and improving the surface quality of the pipe fittings.

[0021] The implementation principle of this application embodiment is as follows: S1: The front end of the mother tube 101 is sharpened. When drawing, one end of the mother tube 101 needs to pass through the inner hole formed after the lower mold 2 and the upper mold 3 are fixed. The outer diameter of the tip of the mother tube 101 needs to be processed to be smaller than the inner hole so that one end of the mother tube 101 can pass through the inner hole and meet the mold passing conditions. S2: Once one end of the mother tube 101 is inserted into the inner hole, the pulling operation can be prepared. Place the core 13 inside the mother tube 101 to be pulled, insert the tip of the mother tube 101 into the inner hole, start the hydraulic cylinder 15, and the hydraulic cylinder 15 pushes the mother tube 101 forward through the push plate 16 fixedly connected to the output end, so that the tip of the mother tube 101 extends out of the inner hole, making it convenient for the traction device to clamp and pull the extended area. S3: During the drawing process, lubricating oil is poured into the sponge block 12 located between the first annular block 6 and the second annular block 8 through the oil injection pipe 9. During the drawing process, the outer wall of the pipe can be wiped with lubricating oil to reduce the friction during the drawing process. S4: During the drawing process, under the action of traction force, the mother tube 101 is supported by the mandrel 13 and passes through the inner hole. The tapered structure on one side of the inner hole cooperates with the mandrel 13 to shrink the outer diameter and form a tapered transition section 104. The fixing of the upper and lower molds is removed, and the mother tube 101 that has been drawn and formed into the tapered transition section 104 is taken out. The sponge block 12 fitted on the outer wall of the mother tube 101 is also removed. The tapered transition section 104 can be connected to pipes with different outer diameter ends, so that multiple different outer radius sections are formed along the axial direction on the same pipe body. At the same time, the mandrel 13 and the tapered inner hole are used to stabilize the outer diameter and wall thickness of the pipe after drawing. S5: Perform end trimming and cleaning on the drawn multi-stage reducing pipe; By changing the processing method, which differs from forming multiple segments with different outer radii along the axial direction on the same integrally molded tube, this method uses individual processing. The tail end of the mother tube 101 is contracted to form a conical transition section 104 by using a tapered structure on one side of the inner hole in conjunction with the core head 13. Then, the connection between the upper mold 3 and the lower mold 2 is removed, and the first annular block 6 and the second annular block 8 are separated. This allows the mother tube 101 with the conical transition section 104 to be removed. The sponge block 12 fitted onto the outer wall of the mother tube 101 is then removed. This process involves individually drawing the segments during processing. Each conical transition section 104 is used to weld and fix the connecting pipes together. Compared with one-piece molding, this processing method does not require the design of complex one-piece molding molds or the control of multi-level dimensional synchronization. The processing technology is simpler, effectively reducing the processing difficulty and mold cost. At the same time, during the drawing process, lubricating oil is poured into the sponge block 12 through the oil injection pipe 9. The sponge block 12 can evenly wipe and lubricate the outer wall of the pipe during the drawing process, reducing the friction between the pipe wall and the mold, effectively avoiding defects such as scratches and pulls during the drawing process, and improving the surface quality of the pipe fittings.

[0022] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A thin-walled, multi-stage tapered transition reducer tube made of oxygen-free copper, comprising a multi-stage tapered tube (1), characterized in that: The multi-stage conical tube (1) includes a main tube (101), a first outer diameter section (102), and a second outer diameter section (103). A conical transition section (104) is fixedly provided on one side of the main tube (101), the first outer diameter section (102), and the second outer diameter section (103). The second outer diameter section (103) is fixedly connected to the conical transition section (104) of the first outer diameter section (102), and the first outer diameter section (102) is fixedly connected to the conical transition section (104) of the main tube (101).

2. The oxygen-free copper thin-walled multi-stage conical transition reducer tube according to claim 1, characterized in that: The outer diameter of the conical transition section (104) is consistent with the outer diameter of the pipe that is fixedly connected to it.

3. A drawing process for an oxygen-free copper thin-walled multi-stage conical transition reducer tube, applied to the oxygen-free copper thin-walled multi-stage conical transition reducer tube as described in any one of claims 1-2, characterized in that: Includes the following steps: S1: The front end of the mother tube (101) is sharpened. When drawing, one end of the mother tube (101) needs to pass through the inner hole formed after the lower mold (2) and the upper mold (3) are fixed. The outer diameter of the tip of the mother tube (101) needs to be made smaller than the inner hole so that one end of the mother tube (101) can pass through the inner hole and meet the mold passing conditions. S2: Once one end of the mother tube (101) is inserted into the inner hole, the pulling operation can be prepared. Place the core (13) inside the mother tube (101) to be pulled, insert the tip of the mother tube (101) into the inner hole, start the hydraulic cylinder (15), and the hydraulic cylinder (15) pushes the mother tube (101) forward through the push plate (16) fixedly connected to the output end, so that the tip of the mother tube (101) extends out of the inner hole, making it convenient for the traction device to clamp and pull the extended area. S3: During the drawing process, lubricating oil is poured into the sponge block (12) located between the first annular block (6) and the second annular block (8) through the oil injection pipe (9). During the drawing process, the outer wall of the pipe can be wiped with lubricating oil to reduce the friction during the drawing process. S4: During the drawing process, under the action of traction force, the mother tube (101) passes through the inner hole with the support of the mandrel (13). The tapered structure on one side of the inner hole cooperates with the mandrel (13) to shrink the outer diameter and form a tapered transition section (104). The fixing of the upper and lower molds is removed, and the mother tube (101) that has been drawn and formed into a tapered transition section (104) is taken out. The sponge block (12) fitted on the outer wall of the mother tube (101) is also removed. Through the tapered transition section (104), it can be connected to pipes with different outer diameter ends, so that multiple different outer radius sections are formed along the axial direction on the same pipe body. At the same time, the mandrel (13) and the tapered inner hole are used to stabilize the outer diameter and wall thickness of the pipe after drawing. S5: Perform end trimming and cleaning on the multi-stage reducing pipe after drawing.

4. The drawing process of an oxygen-free copper thin-walled multi-stage conical transition reducer tube according to claim 3, characterized in that: The lower mold (2) has two positioning pins (11) nested inside the two positioning holes. The upper mold (3) has mounting holes at the bottom corresponding to the positioning pins (11). The lower mold (2) and the upper mold (3) are fixed by four first bolts (4) that pass through the upper mold (3) and extend into the lower mold (2) and are threadedly connected to it.

5. The drawing process of an oxygen-free copper thin-walled multi-stage conical transition reducer tube according to claim 3, characterized in that: The oil injection pipe (9) has a cap (10) fitted on the outer wall of the end that extends out of the upper mold (3).

6. The drawing process of an oxygen-free copper thin-walled multi-stage conical transition reducer tube according to claim 3, characterized in that: The first annular block (6) is fixed by passing through the first annular block (6) with the second bolt (5) and being threadedly connected to the lower mold (2).

7. The drawing process of an oxygen-free copper thin-walled multi-stage conical transition reducer tube according to claim 3, characterized in that: The second annular block (8) is fixed by passing through the second annular block (8) with two third bolts (7) and being threadedly connected to the upper mold (3).

8. The drawing process of an oxygen-free copper thin-walled multi-stage conical transition reducer tube according to claim 3, characterized in that: A fixing plate (14) is fixedly installed at the end of the hydraulic cylinder (15) away from the push plate (16), and the fixing plate (14) is fixedly connected to the base.

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