CN110576088B - 90-degree bending forming method and device for large-diameter thin pipe - Google Patents
90-degree bending forming method and device for large-diameter thin pipe Download PDFInfo
- Publication number
- CN110576088B CN110576088B CN201910807482.4A CN201910807482A CN110576088B CN 110576088 B CN110576088 B CN 110576088B CN 201910807482 A CN201910807482 A CN 201910807482A CN 110576088 B CN110576088 B CN 110576088B
- Authority
- CN
- China
- Prior art keywords
- pipe fitting
- pipe
- bending
- bent
- male die
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D43/00—Feeding, positioning or storing devices combined with, or arranged in, or specially adapted for use in connection with, apparatus for working or processing sheet metal, metal tubes or metal profiles; Associations therewith of cutting devices
- B21D43/003—Positioning devices
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D9/00—Bending tubes using mandrels or the like
- B21D9/08—Bending tubes using mandrels or the like in press brakes or between rams and anvils or abutments; Pliers with forming dies
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D9/00—Bending tubes using mandrels or the like
- B21D9/16—Auxiliary equipment, e.g. machines for filling tubes with sand
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/30—Stress-relieving
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
Abstract
According to the press bending forming method and the press bending device for the large-caliber thin pipe, provided by the invention, the liquid-filled pipe fitting is placed into the cavity of the female die, and the liquid-filled press bending is carried out in stages through the three male dies with different bending radiuses, so that the bent pipe is finally obtained. The method has the advantages of simple process flow, few influence factors influencing the forming quality of the bent pipe, easy control of product quality, capability of improving the automation degree of product processing and product quality consistency. By implementing the method, a thin straight pipe with the diameter of more than 100cm can be bent into a bent pipe with the bending angle of 90 degrees, the forming process is simplified, and the bent pipe forming efficiency is improved.
Description
Technical Field
The invention belongs to the technical field of liquid-filled bending, and particularly relates to a bending forming method and a bending device for a large-caliber thin pipe.
Background
With the continuous development of pipe bending forming technology and the requirements of product structure design on the light weight and integration of parts, a large number of structural parts are produced by adopting thin-wall large-diameter pipe blanks, wherein ultrathin bending pipe fittings are widely applied in the fields of automobiles, aviation, aerospace and the like and are commonly used in automobile air inlet parts, automobile body structural parts and pipelines of various systems of aviation and aerospace. In the prior art, a straight pipe is usually pressed into a bent pipe by using a mould with an elbow, the method is suitable for pipe fittings with the diameter-thickness ratio (D/t) less than or equal to 50, but for pipe fittings with the diameter-thickness ratio more than 50 (particularly large-diameter thin walls), the conventional bending forming process method is not suitable any more, and the defects of wrinkling of the bent inner side pipe wall, thickness reduction of the bent outer side wall, even cracking and the like are more likely to occur in the bending forming of the ultrathin pipe fittings.
The problems of wrinkling and cracking can be effectively reduced by carrying out bending after liquid is filled in the pipe fitting, but the larger the diameter of the pipe fitting is, the thinner the pipe wall is, the higher the bending forming difficulty of the pipe fitting is, the liquid filling bending forming in the prior art is usually used for bending the pipe fitting with the diameter of less than 63mm by 30-70 degrees, while a large thin pipe with the diameter of more than 70cm, the diameter-thickness ratio of more than 60 and the bending angle of 90 degrees is often used in an aerospace system, and the thin pipe with the diameter of more than 150cm is difficult to bend to 90 degrees by adopting the existing liquid filling bending technology. For example, when a straight pipe having a diameter of 93cm and a wall thickness of 1.5cm is produced into a structural member having a diameter-thickness ratio of 63, a bending radius of 136.5mm, a relative bending radius of 1.46 and a bending angle of 90 °, a plate material is usually first drawn and formed into a half of the structural member by a drop hammer die, and then the two half structural members are welded to form a final structural member. The process method has complicated flow, a plurality of factors influencing the forming quality of the structural part, great difficulty in controlling the product quality and long processing period of the structural part; the drawing precision of the blanking die is not high, the forming quality is unstable, and large allowance removal and trimming work is required; in the production process, a special welding fixture is needed to position and weld two half of the structural parts, so that the production efficiency is low, the mechanical automation degree is low, and the product quality is unstable. Therefore, from the starting material to the completion of the production of the structural element, it is necessary to consume a considerable amount of time and economic costs, while it is not possible to ensure that the structural element finally obtained meets the design requirements, often by completing the task in a manner that preserves the quality.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a press bending method and a press bending apparatus for a large-diameter thin pipe.
In order to achieve the above purpose, the invention adopts the technical scheme that: a90-degree bending forming method for a large-caliber thin pipe comprises the following steps:
step 2, the primary bent pipe is filled with liquid and then placed on a female die, the first bending position of the pipe fitting is located at the opening of a cavity of the female die, a secondary male die is adopted for secondary bending, and then secondary annealing heat treatment is carried out on the pipe fitting to obtain a secondary bent pipe;
the ratio of the radius of the pipe fitting to be bent to the radii of the elbows of the three-time male die, the two-time male die and the one-time male die is 1: 1: (1.5-2): (3-4).
Because the smaller the bending radius, the more serious the pipe deformation, the larger the pressing amount, and the more likely the forming defect occurs, the invention carries out the liquid filling press bending on the pipe by three different male dies with sequentially reduced elbow radii in stages, in the steps 1 and 2, the primary male die and the secondary male die with larger elbow radii are adopted for carrying out the liquid filling press bending forming, the purpose is to adopt the male die with larger bending radii, the contact area between the pipe and the male die can be increased in the forming process of the pipe, the flow of the pipe material is controlled by utilizing the friction force between the die and the pipe, the wrinkling is reduced, the defect of the over-quick thinning of the wall thickness of the bending section is prevented, and the like; in the step 1, a bending part matched with a die head of a primary male die is formed on the pipe fitting, in the step 2, the bending part is extruded to be matched with an elbow of the secondary male die through the secondary male die, and finally, in the step 3, the bending part of the pipe fitting is directly bent and formed by adopting a tertiary male die with the same radius as the radius to be bent and pressed, in order to prevent the processing hardening in the forming process of each stage, annealing heat treatment is matched between the working procedures, and finally, the liquid-filled press bending forming of the thin-wall pipe fitting with a large bending angle is obtained. The method has the advantages of simple process flow, few influencing factors influencing the forming quality of the bent pipe, easy control of product quality, capability of improving the automation degree of product processing and product quality consistency.
Specifically, in the steps 1, 2 and 3, one end of the pipe fitting is sealed, the other end of the pipe fitting is connected with the hydraulic control system, the hydraulic control system is used for keeping the liquid pressure in the pipe fitting within a set range in the processes of liquid filling, liquid drawing and bending of the pipe fitting, the shape of the pipe fitting causes the volume of an inner cavity to change in the bending process, and the hydraulic system is used for controlling the liquid pressure in the pipe fitting to keep unchanged.
During annealing heat treatment, an applicable annealing temperature is selected according to the material of the pipe fitting, specifically, the pipe fitting is made of stainless steel, and the stress-relief annealing heat treatment is performed on the pipe fitting at 300-350 ℃ in the steps 1 and 2.
The invention also provides a bending device, which is applied to the 90-degree bending forming method of the large-caliber thin pipe and comprises a female die which is fixedly arranged, wherein the female die is provided with a cavity, a pipe fitting to be bent is arranged on the female die, the part of the pipe fitting to be bent is positioned at the opening of the cavity, the bending device also comprises a male die which is arranged at the upper part of the female die through a lifting mechanism, and a pressing block which is arranged between the female die and the male die, the lower end of the male die is provided with an elbow which corresponds to the cavity of the female die, and the pressing block is fixed at two ends of; the male die comprises a primary male die, a secondary male die and a tertiary male die which are respectively used for carrying out the first press bending, the second press bending and the third press bending in the steps 1, 2 and 3, and the ratio of the radius of the pipe fitting to be pressed and bent to the radii of the elbows of the tertiary male die, the secondary male die and the primary male die is 1: 1: (1.5-2): (3-4). The lifting mechanism in the device is used for driving the male die to descend or ascend, and the existing lifting mechanism is adopted, for example, an oil cylinder can be adopted.
Specifically, the briquetting lower part sets up and waits to bend the arc pressure mouth of pipe fitting shape adaptation, and the briquetting mainly used is fixed in the bed die with the pipe fitting on, when the formpiston pushes down, guarantees that the pipe fitting can not remove, pushes down pipe fitting upper portion through the arc pressure mouth of briquetting lower part, makes the pipe fitting more stable at the in-process that bends.
Specifically, the female die is formed by combining two parallel and fixedly arranged supporting blocks, the tops of the two supporting blocks are arc-shaped, and a gap between the two supporting blocks is used as a cavity.
Specifically, the bed die includes the base member, the arc recess that the radius adaptation of department of bending is treated with the pipe fitting to base member top setting size is as the die cavity, and the advantage of this kind of bed die is through the angle of bending that adopts the fixed bed die of die cavity size can be accurate control pipe fitting, and the shortcoming is when the angle of bending that needs change the pipe fitting, need change the bed die of different die cavity sizes, and this kind of bed die accuracy is high, but the flexibility is not strong.
The invention has the beneficial effects that:
according to the press bending forming method and the press bending device for the large-caliber thin pipe, provided by the invention, the liquid-filled pipe fitting is placed into the cavity of the female die, and the liquid-filled press bending is carried out in stages through the three male dies with different bending radiuses, so that the bent pipe is finally obtained. The method has the advantages of simple process flow, few influence factors influencing the forming quality of the bent pipe, easy control of product quality, capability of improving the automation degree of product processing and product quality consistency. By implementing the method, a thin straight pipe with the diameter of more than 100cm can be bent into a bent pipe with the bending angle of 90 degrees, the forming process is simplified, and the bent pipe forming efficiency is improved.
Drawings
FIG. 1 is a schematic view of a press bending step 1 in the example;
FIG. 2 is a schematic view of a press bending step 2 in the example;
FIG. 3 is a schematic view of a press bending step 3 in the embodiment;
wherein, 1 is a supporting block, 2 is a primary male die, 3 is a secondary male die, 4 is a tertiary male die, 5 is a pressing block, 6 is a hydraulic control system, and 7 is a pipe fitting.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
Examples
The embodiment provides a bending device, which comprises a fixed female die, a male die and a pressing block 5, wherein the male die is arranged on the upper part of the female die through a lifting mechanism; the female die is formed by combining two parallel and fixedly arranged supporting blocks 1, the tops of the two supporting blocks 1 are arc-shaped, and a gap between the two supporting blocks 1 serves as a die cavity; the lower end of the male die is provided with an elbow corresponding to the position of the cavity of the female die; the lower part of the pressing block 5 is provided with an arc-shaped pressing opening matched with the shape of the pipe fitting 7 to be bent; the male die comprises a primary male die 2, a secondary male die 3 and a tertiary male die 4, wherein the ratio of the radius to be bent of the pipe fitting 7 to the bend radii of the tertiary male die 4, the secondary male die 3 and the primary male die 2 is 1: 1: 1.6: 3.6.
the method for bending the large-caliber thin pipe by 90 degrees by adopting the bending device provided by the embodiment comprises the following steps:
step 2, detaching the primary male die 2 from the lifting mechanism, installing the secondary male die 3 on the lifting mechanism, as shown in fig. 2, placing a primary bent pipe (hereinafter referred to as a pipe fitting 7) on a female die, enabling a first bending position of the pipe fitting 7 to be located at an opening of a cavity of the female die, fixing two ends of the pipe fitting 7 through a pressing block 5, sealing one end of the pipe fitting 7, connecting the other end of the pipe fitting 7 with a hydraulic control system 6, filling liquid into the pipe fitting 7 through the hydraulic control system 6, starting the lifting mechanism to drive the secondary male die 3 to descend and press and bend the pipe fitting 7 for the second time, then pumping out the liquid in the pipe fitting 7 through the hydraulic control system 6, and carrying out secondary annealing heat treatment after taking off the pipe fitting 7 to obtain a secondary;
and 3, detaching the secondary male die 3 from the lifting mechanism, installing the tertiary male die 4 on the lifting mechanism, placing a secondary bent pipe (hereinafter referred to as a pipe fitting 7) on the female die as shown in fig. 3, enabling the second bending position of the pipe fitting 7 to be located at the opening of the cavity of the female die, fixing two ends of the pipe fitting 7 through a pressing block 5, sealing one end of the pipe fitting 7, connecting the other end of the pipe fitting 7 with a hydraulic control system 6, filling liquid into the pipe fitting 7 through the hydraulic control system 6, starting the lifting mechanism to drive the tertiary male die 4 to descend and press and bend the pipe fitting 7 for the third time, then pumping out the liquid in the pipe fitting 7 through the hydraulic control system 6, taking off the pipe fitting 7 and carrying out the third annealing heat treatment to obtain a bent pipe finished product with a bending angle.
The press bending apparatus and the press bending method provided in the present embodiment can press and bend a thin straight pipe having a diameter of 100cm or more into a bent pipe having a bending angle of 90 °, and the forming process is simple and the bent pipe forming efficiency is high.
The above examples of the present invention are merely illustrative of the present invention and are not intended to limit the embodiments of the present invention. Variations and modifications in other variations will occur to those skilled in the art upon reading the foregoing description. Not all embodiments are exhaustive. All obvious changes and modifications of the present invention are within the scope of the present invention.
Claims (7)
1. A90-degree bending forming method of a large-caliber thin pipe is characterized by comprising the following steps:
step 1, placing the pipe fitting on a female die, enabling the position, to be bent, of the pipe fitting to be located at an opening of a cavity of the female die, performing first bending by using a primary male die after filling liquid into the pipe fitting, and performing first annealing heat treatment on the pipe fitting to obtain a primary bent pipe;
step 2, the primary bent pipe is filled with liquid and then placed on a female die, the first bending position of the pipe fitting is located at the opening of a cavity of the female die, a secondary male die is adopted for secondary bending, and then secondary annealing heat treatment is carried out on the pipe fitting to obtain a secondary bent pipe;
step 3, the secondary bent pipe is filled with liquid and then placed on a female die, the second bending position of the pipe fitting is located at the opening of a cavity of the female die, third bending is carried out by adopting a third male die, and then third annealing heat treatment is carried out on the pipe fitting, so that the bent pipe with the bending angle of 90 degrees is obtained;
the ratio of the radius of the pipe fitting to be bent to the radii of the elbows of the three-time male die, the two-time male die and the one-time male die is 1: 1: (1.5-2): (3-4).
2. The 90 ° press bending method according to claim 1, wherein in steps 1, 2, and 3, one end of the pipe fitting is sealed, the other end of the pipe fitting is connected to a hydraulic control system, and the hydraulic pressure inside the pipe fitting is maintained within a set range during the processes of filling, drawing and press bending the pipe fitting by the hydraulic control system.
3. The 90 DEG press bending forming method for the large-caliber thin pipe according to claim 1, wherein the pipe fitting is made of stainless steel, and the stress relief annealing heat treatment at 300-350 ℃ is carried out on the pipe fitting in the steps 1 and 2.
4. A bending device is applied to the 90-degree bending forming method of the large-caliber thin pipe as claimed in any one of claims 1 to 3, and comprises a fixedly arranged female die, wherein the female die is provided with a cavity, a pipe to be bent is arranged on the female die, and the part of the pipe to be bent, which is to be bent, is positioned at the opening of the cavity; the male die comprises a primary male die, a secondary male die and a tertiary male die which are respectively used for carrying out the first press bending, the second press bending and the third press bending in the steps 1, 2 and 3, and the ratio of the radius of the pipe fitting to be pressed and bent to the radii of the elbows of the tertiary male die, the secondary male die and the primary male die is 1: 1: (1.5-2): (3-4).
5. A bending device according to claim 4, wherein the lower part of the press block is provided with an arc-shaped pressing opening matched with the shape of the pipe fitting to be bent.
6. The press bending device according to claim 4, wherein the female die is formed by combining two support blocks which are parallel and fixedly arranged, the tops of the two support blocks are arc-shaped, and a gap between the two support blocks is used as a cavity.
7. A press bending device according to claim 4, wherein the female die comprises a base body, and an arc-shaped groove with a size matched with the radius of a part to be bent of the pipe fitting is arranged at the top of the base body to be used as a cavity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910807482.4A CN110576088B (en) | 2019-08-29 | 2019-08-29 | 90-degree bending forming method and device for large-diameter thin pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910807482.4A CN110576088B (en) | 2019-08-29 | 2019-08-29 | 90-degree bending forming method and device for large-diameter thin pipe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110576088A CN110576088A (en) | 2019-12-17 |
| CN110576088B true CN110576088B (en) | 2021-01-26 |
Family
ID=68812467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910807482.4A Active CN110576088B (en) | 2019-08-29 | 2019-08-29 | 90-degree bending forming method and device for large-diameter thin pipe |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110576088B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112570517B (en) * | 2020-11-26 | 2022-02-08 | 燕山大学 | Large-scale pipe fitting forming accuracy control equipment |
| CN117483533A (en) * | 2024-01-03 | 2024-02-02 | 天津天锻航空科技有限公司 | Forming method of airplane oil transportation half pipe parts |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5471857A (en) * | 1994-03-07 | 1995-12-05 | Mascotech Tubular Products, Inc. | Process for hydroforming a vehicle manifold |
| CN101829716B (en) * | 2010-05-04 | 2011-07-27 | 吉林省昊宇石化电力设备制造有限公司 | Method for pressing nuclear power main pipeline |
| JP2014028382A (en) * | 2012-07-31 | 2014-02-13 | Nisshin Steel Co Ltd | Bending method of metal pipe |
| CN103658274A (en) * | 2012-09-11 | 2014-03-26 | 北京首宏钢重型装备技术有限公司 | Pipe fitting forming device |
| KR20140065072A (en) * | 2012-11-21 | 2014-05-29 | 한국기계연구원 | Vending apparatus for pipe |
| CN206676971U (en) * | 2017-03-09 | 2017-11-28 | 深圳市兰博三思材料检测有限公司 | A kind of steel pipe bends fixture |
| CN109158458B (en) * | 2018-09-29 | 2020-08-25 | 天津市天锻压力机有限公司 | Method for performing liquid-filled bending on pipe by using composite filling medium |
| CN109807567B (en) * | 2019-03-19 | 2019-11-08 | 南昌航空大学 | A method of improving 1D and following small-bend radius pipe bend straight end length |
-
2019
- 2019-08-29 CN CN201910807482.4A patent/CN110576088B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110576088A (en) | 2019-12-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3509217B2 (en) | Forming method and forming apparatus for deformed cross-section pipe | |
| CN110576088B (en) | 90-degree bending forming method and device for large-diameter thin pipe | |
| CN101537447B (en) | Pipe liquid filled shear bending and forming method | |
| CN110328278B (en) | Large thin-wall curved surface part forming device and method | |
| CN105013908B (en) | For the assembling die and manufacturing process of the shaping of flange pipe nipple | |
| CN108817194B (en) | Hydraulic preparation method of multi-elbow pipe | |
| CN104070129B (en) | Hot extrusion forging die for pipe with flange and deep blind taper hole shaft and forging technology thereof | |
| CN106424355A (en) | Annular thin-wall part molding die and molding method | |
| CN105598265A (en) | Overall forming method of small-relative-bending-radius and large-diameter-thickness-ratio thin-walled bent pipe fitting | |
| CN105268835A (en) | Three-segment type arc support swing-along-shape bend pipe lower die | |
| CN107442636B (en) | The corrugated removing method of curved surface member forming device, formed parts and system | |
| CN101693263B (en) | Method for preparing pipe bending part by adopting flexible extrusion forming | |
| JP4220562B2 (en) | Metal bellows tube forming method | |
| CN101693338B (en) | Preparation method of reducing breeches tee joint | |
| Wang et al. | State⁃ of⁃ the⁃ Art of Stamping⁃ Forging Process with Sheet Metal Blank | |
| CN110369549B (en) | Integral rolling method for transition step pipe with smaller pipe diameter ratio and conical surface | |
| CN103143611A (en) | Testing device and method of friction influence in plate hydraulic forming | |
| CN105149389A (en) | Bent pipe, bent pipe machining equipment, bent pipe machining method and control method | |
| CN213256517U (en) | Large-diameter thin-walled pipe liquid-filling bending forming device | |
| CN2863296Y (en) | Hydraulic forming cavity die with sliding support | |
| JP2005095983A (en) | Bellows pipe, manufacturing method therefor, and die | |
| CN110976672B (en) | Method and device for realizing connection of plate and pipe by utilizing plastic deformation of plate | |
| CN201534182U (en) | Extrusion forming die of reducing trouser-shaped tee | |
| CN113102598A (en) | Liquid-filling pressing forming device and method for special-shaped section pipe fitting | |
| CN201534198U (en) | Bending forming die for reducing trouser-shaped tee |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |