CN112756424B - Method for expanding and drawing metal pipe - Google Patents
Method for expanding and drawing metal pipe Download PDFInfo
- Publication number
- CN112756424B CN112756424B CN202011509562.0A CN202011509562A CN112756424B CN 112756424 B CN112756424 B CN 112756424B CN 202011509562 A CN202011509562 A CN 202011509562A CN 112756424 B CN112756424 B CN 112756424B
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- pipe
- expanding
- drying
- diameter
- expanding die
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- 238000000034 method Methods 0.000 title claims abstract description 24
- 239000002184 metal Substances 0.000 title claims abstract description 7
- 239000002253 acid Substances 0.000 claims abstract description 21
- 238000004140 cleaning Methods 0.000 claims abstract description 20
- 238000001035 drying Methods 0.000 claims abstract description 20
- 238000004513 sizing Methods 0.000 claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 14
- 238000005498 polishing Methods 0.000 claims abstract description 10
- 238000010438 heat treatment Methods 0.000 claims abstract description 5
- 230000001681 protective effect Effects 0.000 claims abstract description 3
- 150000002148 esters Chemical class 0.000 claims description 10
- 239000010687 lubricating oil Substances 0.000 claims description 10
- 239000003921 oil Substances 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- 238000005520 cutting process Methods 0.000 claims description 4
- 230000007547 defect Effects 0.000 claims description 4
- 230000001050 lubricating effect Effects 0.000 claims description 4
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims description 4
- UOCLXMDMGBRAIB-UHFFFAOYSA-N 1,1,1-trichloroethane Chemical compound CC(Cl)(Cl)Cl UOCLXMDMGBRAIB-UHFFFAOYSA-N 0.000 claims description 2
- 239000007921 spray Substances 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims 1
- 229910001220 stainless steel Inorganic materials 0.000 description 15
- 239000010935 stainless steel Substances 0.000 description 15
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000000243 solution Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C1/00—Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
- B21C1/16—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes
- B21C1/22—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes specially adapted for making tubular articles
- B21C1/24—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes specially adapted for making tubular articles by means of mandrels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C3/00—Profiling tools for metal drawing; Combinations of dies and mandrels
- B21C3/02—Dies; Selection of material therefor; Cleaning thereof
- B21C3/12—Die holders; Rotating dies
- B21C3/14—Die holders combined with devices for guiding the drawing material or combined with devices for cooling heating, or lubricating
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Metal Extraction Processes (AREA)
Abstract
The invention relates to a method for expanding and drawing metal pipes, which comprises the following steps: polishing the surface of the pipe, performing acid cleaning treatment by using a prepared mixed acid solution after polishing, performing water cleaning after acid cleaning to remove the residual mixed acid on the pipe, and drying after water cleaning; one end of a pipe to be expanded is subjected to heat treatment, and then the pipe is simply expanded in a hot state, so that the diameter of the pipe is larger than the maximum diameter of an expanding die, and the expanding die can smoothly enter the pipe; introducing tensile oil into the pipe, forming a protective oil film on the inner wall of the pipe, and reducing the friction between the expanding die and the inner wall; and (4) placing the pipe on a machine tool through the guide device and the sizing device.
Description
Technical Field
The invention relates to a forming method for expanding and drawing a metal pipe, belonging to the field of plastic processing and forming.
Background
Drawing is one of the important production methods of pipes and wires, and is a plastic forming method for forming parts by changing the cross section of pipes and wires. The product prepared by the drawing process has good surface quality and accurate size, can improve the mechanical property of the product, and has the advantages which are not available in other plastic forming.
The expanding drawing is a drawing method of drawing a small-diameter tube blank into a large-diameter tube blank. Expanding drawing is commonly used to produce thin walled tubing of smaller cross-section. In the traditional drawing process, the radius of the pipe is increased, the wall thickness is reduced, and the length of the pipe is shortened, wherein in the drawing process, the pipe is mainly expanded along the circumferential direction and shortened along the length direction of the pipe, so that the wall thickness is prevented from being reduced, and particularly when the thin-walled pipe is subjected to expanding drawing, the wall thickness is limited. Meanwhile, the traditional expanding and drawing method is low in production efficiency and high in cost.
Disclosure of Invention
The invention relates to the field of drawing plastic processing and forming, in particular to a diameter-expanding drawing forming method for a metal pipe.
The invention aims to provide a method for expanding and drawing metal pipes, which solves the problems of uneven wall thickness reduction, uneven deformation of inner and outer diameters, low dimensional precision of produced pipes, low production efficiency and the like in the drawing process of the traditional drawing mode.
By adopting the expanding and drawing method, the wall thickness of the pipe is uniformly reduced, the inner wall of the pipe is smoother, the defects are fewer, the quality of the produced pipe is high, and the production efficiency is improved.
In order to achieve the above objects and achieve the above technical effects, the present invention is realized by the following steps:
polishing the surface of the pipe, performing acid cleaning treatment by using a prepared mixed acid solution after polishing, performing water cleaning after acid cleaning to remove the residual mixed acid on the pipe, and drying after water cleaning;
one end of a pipe to be expanded is subjected to heat treatment, and then the pipe is simply expanded in a hot state, so that the diameter of the pipe is larger than the maximum diameter of an expanding die, and the expanding die can smoothly enter the pipe;
introducing tensile oil into the pipe, forming a protective oil film on the inner wall of the pipe, and reducing the friction between the expanding die and the inner wall;
the pipe is arranged on a machine tool after passing through a guide device and a sizing device;
the core rod penetrates through the pipe, and a detachable expanding die is arranged at the front end of the core rod; the rear end of the core rod is connected to the drawing machine;
one end of the pipe subjected to simple diameter expansion is connected to a movable small tractor, the tractor and the drawing machine are started simultaneously, the tractor and the drawing machine move slowly to two sides, and when the speed reaches the working speed range of 5 mm/min-15 mm/min, a uniform diameter expansion stage is started;
in the expanding process, a lubricating device on the expanding die continuously sprays lubricating oil to the inner wall of the pipe, so that the friction force between the expanding die and the inner wall of the pipe is further reduced;
the diameter-expanded part is pulled out by a tractor through a sizing device;
replacing a larger-diameter expanding die, and repeating the operation until the pipe is expanded to a target size;
taking down the processed pipe, and cutting off the simple diameter-expanding part;
cleaning the pipe by using deoiling ester to remove residual lubricating oil;
and (3) washing the formed pipe with clear water to ensure that the deoiled ester is cleaned and dried.
Preferably, the grinding of the pipe is performed by using a grinding machine.
Preferably, the prepared mixed acid solution is a mixed solution of sulfuric acid, hydrofluoric acid and chromic acid, and the pickling time is 1.5-2 hours.
Preferably, the first drying is completed in a drying furnace, the drying time is 30-60 min, and the temperature is 150-180 ℃ during drying.
Preferably, the angle of the expanding die is 10-20 degrees, and the angle is convenient for the expanding die to move in the pipe without excessive resistance in the expanding process; the length of the sizing device is 80-140 mm, and the sizing device is used for consolidating the expanded part and preventing the defects of rebound deformation and the like.
Preferably, the deoiled ester is formed by mixing trichloroethane and n-hexane.
Preferably, the second drying is performed by using a dryer, the drying time is 15min, and the drying temperature is 50 ℃.
Compared with the traditional drawing mode, the invention has the advantage that the diameter expanding drawing forming is carried out by adopting a mode of simultaneously drawing two ends. One end of the core rod is pulled, and the pipe is expanded by pulling the expanding die; the other end pulls the pipe, and the expanded part is fixed. Therefore, the uneven expansion of the outer wall of the pipe can be reduced, the inner wall of the pipe is smoother, and the forming quality and forming efficiency of the pipe can be improved. Meanwhile, stretching oil and lubricating oil are used before and during drawing, so that friction between the expanding die and the inner wall of the pipe can be well reduced, the forming quality and forming precision of the pipe are effectively improved, and the expanding die is favorable for expanding the pipe.
The invention has the beneficial effects that: the method is simple and easy to implement, can improve the production efficiency of pipe drawing, has wide application in the fields of aerospace, high-speed rail, vehicles, building and petrochemical industry and the like, and can obviously improve the production benefit; the invention has novel structure, can well ensure that the inner diameter and the outer diameter of the pipe are uniformly thinned, can ensure that the inner surface and the outer surface of the pipe have the defects as much as possible by simultaneously drawing the two ends, and has higher forming precision; and the two ends are simultaneously drawn, so that the forming efficiency of the pipe can be improved. The drawing oil and the lubricating oil are used before and during drawing, so that the friction between the expanding die and the inner wall of the pipe can be well reduced, the forming quality and the forming precision of the pipe are effectively improved, and the expanding die is favorable for expanding the pipe.
Drawings
FIG. 1 is a schematic view of expanding and drawing with both ends of the pipe simultaneously acting;
in the figure, 1 a tractor body, 2 a sizing device, 3 a fastening bolt, 4 an expanding die, 5 a guiding device, 6 a pipe material, 7 a core bar and 8 a drawbench body.
Detailed Description
The present invention is further illustrated in detail below with reference to specific examples. The following specific examples are intended to illustrate the invention and are not to be construed as limiting the invention.
Example 1:
polishing the surface of a stainless steel pipe, performing acid cleaning treatment by using a prepared mixed acid solution after polishing, performing water cleaning after acid cleaning, removing the residual mixed acid on the stainless steel pipe, and drying after water cleaning;
secondly, one end of the stainless steel pipe is subjected to heat treatment, and simple expanding is carried out in a hot state, so that the diameter of the stainless steel pipe is larger than the maximum diameter of the expanding die, and the expanding die can smoothly enter the stainless steel pipe;
step three, introducing stretching oil into the stainless steel pipe;
fourthly, the stainless steel pipe penetrates through the guide device and the sizing device and is placed on a machine tool;
fifthly, the core rod penetrates through the stainless steel pipe, a detachable expanding die is installed at the front end of the core rod, and the rear end of the core rod is connected to a drawing machine;
sixthly, connecting one end of the stainless steel pipe subjected to simple diameter expansion treatment to a movable small tractor;
seventhly, starting the traction machine and the drawing machine at the same time, enabling the traction machine and the drawing machine to move to two sides slowly, and entering a constant-speed diameter expansion stage when the speed reaches the working speed range of 5 mm/min-15 mm/min;
eighthly, continuously spraying lubricating oil to the inner wall of the stainless steel pipe by a lubricating device on the expanding die in the expanding process;
ninthly, pulling out the diameter-expanded part by a sizing device through a tractor after the diameter-expanded part is finished;
tenth, replacing the expanding die with larger diameter and repeating the seventh to ninth steps until the diameter of the stainless steel pipe is expanded to the target size;
eleventh, taking down the processed stainless steel tube, and cutting off the simple diameter-expanding part of the stainless steel tube;
step ten, cleaning the stainless steel tube by using deoiling ester to remove residual lubricating oil;
and step thirteen, washing the formed stainless steel tube with clear water to ensure that the deoiled ester is cleaned and dried.
Example 2:
firstly, polishing the surface of a GH4169 pipe, performing acid washing by using a prepared mixed acid solution after polishing, performing water washing after acid washing to remove the residual mixed acid on the GH4169 pipe, and drying after water washing;
secondly, one end of the GH4169 pipe is subjected to heat treatment and is simply expanded under a hot state, so that the diameter of the GH4169 pipe is larger than the maximum diameter of an expanding die, and the expanding die can smoothly enter the GH4169 pipe;
step three, introducing tensile oil into a GH4169 pipe;
fourthly, the GH4169 pipe passes through a guide device and a sizing device and is placed on a machine tool;
fifthly, the core rod penetrates through the GH4169 pipe, a detachable expanding die is installed at the front end of the core rod, and the rear end of the core rod is connected to a drawing machine;
sixthly, connecting one end of the GH4169 pipe subjected to the simple diameter expansion processing to a movable small tractor;
seventhly, starting the traction machine and the drawing machine at the same time, enabling the traction machine and the drawing machine to move to two sides slowly, and entering a constant-speed diameter expansion stage when the speed reaches the working speed range of 5 mm/min-15 mm/min;
eighthly, continuously spraying lubricating oil to the inner wall of the GH4169 pipe by a lubricating device on the expanding die in the expanding process;
ninthly, pulling out the diameter-expanded part by a sizing device through a tractor after the diameter-expanded part is finished;
step ten, replacing a larger-diameter expanding die, and repeating the seventh step to the ninth step until the diameter of the GH4169 pipe is expanded to a target size;
step eleven, taking down the GH4169 pipe after processing, and cutting off the GH4169 pipe by simple diameter expansion;
step ten, cleaning the GH4169 pipe by using deoiling ester to remove residual lubricating oil;
and step thirteen, washing the formed GH4169 tube with clear water to ensure that the deoiled ester is cleaned and dried.
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
Claims (4)
1. A method for expanding and drawing metal pipes is characterized by comprising the following steps:
step 1: polishing the surface of the pipe, performing acid cleaning treatment by using a prepared mixed acid solution after polishing, performing water cleaning after acid cleaning to remove the residual mixed acid on the pipe, and drying after water cleaning;
step 2: one end of a pipe to be expanded is subjected to heat treatment, and then the pipe is simply expanded in a hot state, so that the diameter of the pipe is larger than the maximum diameter of an expanding die, and the expanding die can smoothly enter the pipe;
and step 3: introducing tensile oil into the pipe, forming a protective oil film on the inner wall of the pipe, and reducing the friction between the expanding die and the inner wall;
and 4, step 4: the pipe is arranged on a machine tool after passing through a guide device and a sizing device;
and 5: the core rod penetrates through the pipe, and a detachable expanding die is arranged at the front end of the core rod;
step 6: the rear end of the core rod is connected to the drawing machine;
and 7: one end of the pipe subjected to simple diameter expansion is connected to a movable small-sized tractor, the movable small-sized tractor and a drawing machine are started at the same time, the movable small-sized tractor and the drawing machine slowly move towards two sides, and when the speed reaches the working speed range of 5-15 mm/min, a uniform diameter expansion stage is started;
and 8: in the expanding process, a lubricating device on the expanding die continuously sprays lubricating oil to the inner wall of the pipe, so that the friction force between the expanding die and the inner wall of the pipe is further reduced;
and step 9: the diameter-expanded part is pulled out by a tractor through a sizing device;
step 10: replacing the expanding die with larger diameter and repeating the steps 7-9 until the pipe is expanded to the target size;
step 11: taking down the processed pipe, and cutting off the simple diameter-expanding part;
step 12: cleaning the pipe by using deoiling ester to remove residual lubricating oil;
step 13: washing the formed pipe with clear water to ensure that the deoiled ester is washed clean and dried;
the drying in the step 1 is completed in a drying furnace, the drying time is 30-60 min, and the temperature is 150-180 ℃ during the drying.
2. The method according to claim 1, wherein the angle of the expanding die is 10 ° to 20 °, which facilitates the expanding die to move inside the pipe without excessive resistance during expanding; the length of the sizing device is 80-140 mm, and the sizing device is used for consolidating the expanded part and preventing the defect of rebound deformation.
3. The method of claim 1, wherein the deoiled ester is a mixture of trichloroethane and n-hexane.
4. The method of claim 1, wherein the drying in step 13 is drying with a dryer, the drying time is 15min, and the drying temperature is 50 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011509562.0A CN112756424B (en) | 2020-12-19 | 2020-12-19 | Method for expanding and drawing metal pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011509562.0A CN112756424B (en) | 2020-12-19 | 2020-12-19 | Method for expanding and drawing metal pipe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112756424A CN112756424A (en) | 2021-05-07 |
| CN112756424B true CN112756424B (en) | 2022-03-25 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202011509562.0A Active CN112756424B (en) | 2020-12-19 | 2020-12-19 | Method for expanding and drawing metal pipe |
Country Status (1)
| Country | Link |
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| CN (1) | CN112756424B (en) |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SU275037A1 (en) * | 1967-12-25 | 1979-11-05 | Savin G A | Method of tube expansion by drawing on stationary fixed mandrel |
| JPS589712A (en) * | 1981-07-08 | 1983-01-20 | Toshiba Corp | Formation of tubular body |
| CN2134242Y (en) * | 1991-08-10 | 1993-05-26 | 李晓琳 | Hydraulic automatic machine for drawing inequal wall thickness tube |
| CN101104191A (en) * | 2007-08-02 | 2008-01-16 | 高新张铜股份有限公司 | Super-long hollow metal tube diameter enlarging method |
| CN100528390C (en) * | 2007-11-14 | 2009-08-19 | 攀钢集团成都钢铁有限责任公司 | Limiting core rod cold drawn tube technique and equipment thereof |
| CN104708269B (en) * | 2013-12-11 | 2017-01-11 | 北京有色金属研究总院 | Method for machining large-diameter super-thin-walled tubular product made of high-deformation materials |
| CN208712694U (en) * | 2018-07-11 | 2019-04-09 | 沈阳天元特钢制品有限公司 | A kind of expander of steel pipe cold |
| CN110052545A (en) * | 2019-05-08 | 2019-07-26 | 重庆龙煜精密铜管有限公司 | A kind of large diameter copper pipe expansion drawing production technology |
| CN111069445B (en) * | 2019-11-27 | 2021-03-02 | 江阴和宏精工科技有限公司 | Wall thickness control method for expanding and drawing copper pipe |
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2020
- 2020-12-19 CN CN202011509562.0A patent/CN112756424B/en active Active
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| CN112756424A (en) | 2021-05-07 |
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