CN109175033B - Special-shaped hollow pipe bending forming method - Google Patents
Special-shaped hollow pipe bending forming method Download PDFInfo
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- CN109175033B CN109175033B CN201810960077.1A CN201810960077A CN109175033B CN 109175033 B CN109175033 B CN 109175033B CN 201810960077 A CN201810960077 A CN 201810960077A CN 109175033 B CN109175033 B CN 109175033B
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- hollow pipe
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- 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
Abstract
The invention discloses a special-shaped hollow pipe bending forming method, wherein the special-shaped hollow pipe bending forming method comprises the following steps: and (3) inflating: filling gas into the inner cavity of the hollow pipe before bending so that the pipe wall of the hollow pipe before bending is continuously subjected to pretension; one end of the hollow pipe is closed before bending, and the other end of the hollow pipe is opened; bending: and applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe is bent and formed. According to the special-shaped hollow pipe bending forming method provided by the invention, the pipe wall is continuously subjected to the pretension by filling the gas, and the pretension can reduce the damage of bending moment force to the stress surface of the hollow pipe and reduce the generated gravure when the hollow pipe is bent; and the gas does not need to be cleaned, so that the method is environment-friendly, meanwhile, the gas has good fluidity, and the pretension can be uniformly dispersed, so that the gravure is further reduced.
Description
Technical Field
The invention relates to the technical field of pipeline forming, in particular to a special-shaped hollow pipe bending forming method.
Background
In the process of forming the special-shaped hollow pipe by bending the straight hollow pipe, the stress surface of the hollow pipe is concave easily due to bending moment force generated by bending, and gravure is generated, and the following modes are generally adopted in the prior art for solving the technical problem:
1. sand filling: pouring fine steel sand into the hollow core pipe, pressing the hollow core pipe mechanically, bending the hollow core pipe, and separating the sand from the hollow core pipe in a vibration mode after the special-shaped hollow core pipe is bent and formed. This process is simple but inefficient.
2. Oil filling: high-pressure hydraulic oil is connected to a product, the hollow pipe generates pretension, the phenomenon of indent is generated when the pretension is used for overcoming bending moment, but the liquidity of liquid is poor, some gravure can be generated on the stress surface of the product, and the appearance is attractive. Compared with sand filling, the process is simple and high in efficiency, but the cleaning of hydraulic oil is troublesome, and the environment-friendly requirement is not met.
3. Emulsifying liquid: high-pressure emulsified liquid is injected into the hollow pipe, pretension is generated on the hollow pipe body, and the phenomenon of indent is generated when the pretension is used for overcoming bending moment. Compared with sand filling, the process is simple and high in efficiency, and compared with oil filling, the process is convenient to clean, but because the fluidity of the liquid is poor, the stress surface of the product still generates some gravure, the appearance is affected, and waste to a certain extent can be formed.
4. Internal core extraction body: the combined knuckle core is inserted into the tube body to support the bending moment force generated during bending. The method is simple, but is limited by space, the core is difficult to be drawn by the thin tube, and the subsequent cleaning is very troublesome.
It can be seen that the prior art is still in need of improvement and development.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a method for bending and forming a special-shaped hollow pipe, which can reduce the generation of intaglio on the stressed surface of the hollow pipe during bending of the hollow pipe, does not need to be cleaned afterwards, and is environment-friendly.
The technical scheme of the invention is as follows:
a method for bending and forming a special-shaped hollow pipe comprises the following steps:
and (3) inflating: filling gas into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension; one end of the hollow pipe is closed and the other end is opened before bending and forming;
bending: and applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe is bent and formed.
In a further preferred aspect, the inflation: filling gas into the inner cavity of the hollow pipe before bending forming, and before the pipe wall of the hollow pipe before bending forming continuously receives pretension, the method further comprises the following steps:
sealing: and sealing any end of the hollow pipe before bending and forming with openings at two ends.
In a further preferred scheme, the hollow tube is sealed before bending and forming by means of riveting, brazing, connecting sealed structural parts or injecting sealant.
In a further preferred aspect, the inflation: filling gas into the inner cavity of the hollow pipe before bending forming, and before the pipe wall of the hollow pipe before bending forming continuously receives pretension, the method further comprises the following steps:
connecting joints: and connecting any one end of the hollow pipe before bending and forming with openings at two ends with an air inlet joint, wherein the air inlet joint is used for connecting an inflating device, and the inflating device is used for inflating air into the inner cavity of the hollow pipe before bending and forming.
In a further preferred aspect, the inflation: filling gas into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming continuously bears pretension, specifically:
and (3) inflating: the inflation device fills gas with specified air pressure into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension within a preset range.
In a further preferable scheme, when the hollow tube is an aluminum alloy hollow flat tube with the wall thickness of less than or equal to 2mm, the air pressure of the gas filled into the inner cavity of the hollow tube by the inflating device before bending forming is between 0.5Mpa and 12 Mpa.
In a further preferable scheme, when the hollow tube is an aluminum alloy hollow flat tube with the wall thickness smaller than 0.5mm, the air pressure of air filled into the inner cavity of the hollow tube before bending forming by the air filling device is 0.8Mpa to 12 Mpa.
In a further preferable scheme, when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of 1mm to 1.5mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending forming by the air filling device is 1.5Mpa to 12 Mpa.
In a further preferable scheme, when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of 1.5mm to 2mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending forming by the air filling device is 1.5Mpa to 12 Mpa.
A special-shaped hollow pipe bending and forming system comprises: the gas filling device is used for filling gas into an inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension, one end of the hollow pipe before bending forming is closed, and the other end of the hollow pipe before bending forming is opened; the bending device is used for applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe is bent and formed.
Compared with the prior art, the special-shaped hollow pipe bending forming method provided by the invention adopts the following steps: and (3) inflating: filling gas into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension; one end of the hollow pipe is closed and the other end is opened before bending and forming; bending: and applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe is bent and formed. According to the special-shaped hollow pipe bending forming method provided by the invention, the pipe wall is continuously subjected to the pretension by filling the gas, and the pretension can reduce the damage of bending moment force to the stress surface of the hollow pipe and reduce the generated gravure when the hollow pipe is bent; and the gas does not need to be cleaned, so that the method is environment-friendly, meanwhile, the gas has good fluidity, and the pretension can be uniformly dispersed, so that the gravure is further reduced.
Drawings
Fig. 1 is a flowchart of a method for bending and forming a special-shaped hollow core tube according to a preferred embodiment of the present invention.
Fig. 2 is a schematic structural view of the special-shaped hollow pipe bent and formed by the special-shaped hollow pipe bending and forming method of the invention.
Detailed Description
The invention provides a method for bending and forming a special-shaped hollow pipe, which is further described in detail below by referring to the attached drawings and examples in order to make the purpose, technical scheme and effect of the invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 1 and 2, the invention discloses a method for bending and forming a special-shaped hollow core tube 100, which comprises the following steps: s100, inflating: and filling gas into the inner cavity of the hollow pipe before bending and forming, so that the pipe wall of the hollow pipe before bending and forming is continuously subjected to pretension.
In a preferred embodiment of the present invention, the method of continuously pre-tensioning the tube wall of the hollow tube before bending and forming is as follows: and continuously filling gas into the inner cavity of the hollow pipe before bending and forming through an inflating device. In the process, the sealing and air leakage of the rest positions of the pipe wall except the air inlet are ensured to be good, but it can be understood that the small reserved holes, the small-size gaps left due to insufficient sealing and the like do not greatly influence the pretension force on the pipe wall (the continuous air filling can compensate the air leakage caused by the gaps), and the purpose of reducing the gravure can also be achieved. That is, the hollow tube before bending forming has good sealing effect (the gas inlet is not counted), but the invention is not affected by serious gas leakage.
The port at one end of the hollow tube before the gas inlet is formed by bending is better, and the port is easily connected with the gas inlet joint 200, so that a better sealing environment is formed. However, it is conceivable that other positions besides the port may be used as gas inlets, but in comparison, the port is the simplest to intake, easy to operate and more efficient.
If one end of the hollow tube is open before bending and forming, the other end of the hollow tube should be sealed, and the hollow tube before bending and forming is usually a hollow tube with two open ends, therefore, before inflating, the method further comprises the following steps: sealing: and sealing any end of the hollow pipe before bending and forming with openings at two ends.
For the hollow tube before bending molding of other structures, for example, the hollow tube with both ends sealed (the hollow tube with both ends sealed before bending, or the hollow tube with both ends sealed in other cases) is processed differently, and the processing method may be: cutting any one of the sealed ports 110, perforating the tube wall, etc. For example, a hollow tube (or a hollow tube with a hole suitable for inflation) with one end open and the other end closed can be directly inflated without treatment.
For the hollow core tube before bending forming which needs sealing, the sealing modes which can be utilized are various: such as riveting, brazing, and connecting a sealing structure (the connection may be interference connection, threaded connection, etc., and the structure of the sealing structure may be various), and injecting a sealant.
The invention preferably connects the air charging device by connecting the air inlet joint 200 at the air inlet port, and specifically, the method comprises the following steps before air charging: connecting joints: and connecting any one end of the hollow pipe before bending and forming with openings at two ends with an air inlet connector 200, wherein the air inlet connector 200 is used for connecting an inflating device, and the inflating device is used for inflating air into the inner cavity of the hollow pipe before bending and forming.
In selecting the gas, the invention requires selecting the gas within a specified gas pressure range according to the wall thickness, material, size and the like of the hollow tube before bending forming. Therefore, the step of inflating is specifically: and (3) inflating: the inflation device fills gas with specified air pressure into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension within a preset range. Bending moment forces for bending are different according to different performances of the hollow pipe before bending forming, so that the effect achieved by the method can be optimized by controlling the pre-tension within a certain range, gravure is reduced as far as possible, and even the generation of gravure is completely avoided.
The invention exemplifies the corresponding relation between the air pressure of the filled gas and the wall thickness and the material of the hollow tube, and concretely comprises the following steps:
when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of less than or equal to 2mm, the air pressure of the gas filled into the inner cavity of the hollow pipe before the hollow pipe is bent and molded by the inflating device is between 0.5Mpa and 12 Mpa.
When the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness smaller than 0.5mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending and forming by the air filling device is 0.8MPa to 12 MPa.
When the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of 1mm to 1.5mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending forming by the air filling device is 1.5Mpa to 12 Mpa.
When the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of 1.5mm to 2mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending forming by the air filling device is 1.5Mpa to 12 Mpa.
S200, bending: and applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe 100 is bent and formed. The selection and use of bending devices, the control of bending moment forces, and the specific bending manner are known in the prior art, and the invention is not described herein in any greater detail.
After the bending step, whether the sealed end 110 needs to be subjected to post-treatment such as cutting and unsealing can be selected according to the function of the special-shaped hollow pipe 100, for example, when the special-shaped hollow pipe 100 is used subsequently, the structure needs to be sealed at one end and open at the other end, and no other treatment needs to be performed. If a special-shaped hollow tube 100 with two open ends is required, the cutting (e.g., brazing), unsealing (e.g., connecting sealed structural members), and the like may be performed according to the sealing manner of the sealing end 110.
Preferably, the present invention provides the sealing manner of the sealing end 110 before bending, i.e., according to the shaped hollow core tube 100 after forming, so as to simplify the process after forming.
The invention also provides a special-shaped hollow pipe bending and forming system, which comprises: the gas filling device is used for filling gas into an inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension, one end of the hollow pipe before bending forming is closed, and the other end of the hollow pipe before bending forming is opened; the bending device is used for applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe is bent and formed, and is specifically described in the embodiment of the method.
It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.
Claims (7)
1. A method for bending and forming a special-shaped hollow pipe is characterized by comprising the following steps:
and (3) inflating: filling gas into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming is continuously subjected to pretension; one end of the hollow pipe is closed and the other end is opened before bending and forming;
bending: applying bending moment force to the pipe wall of the hollow pipe until the special-shaped hollow pipe is bent and formed;
and (3) inflating: filling gas into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming continuously bears pretension, specifically: the inflation device continuously fills gas with specified air pressure into the inner cavity of the hollow pipe before bending forming, so that the pipe wall of the hollow pipe before bending forming continuously bears pretension within a preset range;
if the two ends of the hollow pipe are sealed before bending and forming, cutting any one sealing port or performing pipe wall punching treatment;
if the two ends of the hollow pipe are opened before bending and forming, any end of the hollow pipe which is opened at the two ends before bending and forming is sealed.
2. The method for bending and forming the special-shaped hollow pipe according to claim 1, wherein the hollow pipe is sealed before bending and forming by means of riveting, brazing, connecting sealed structural members or injecting sealant.
3. The profiled hollow pipe bending forming method according to claim 1, wherein the inflation: filling gas into the inner cavity of the hollow pipe before bending forming, and before the pipe wall of the hollow pipe before bending forming continuously receives pretension, the method further comprises the following steps:
connecting joints: and connecting any one end of the hollow pipe before bending and forming with openings at two ends with an air inlet joint, wherein the air inlet joint is used for connecting an inflating device, and the inflating device is used for inflating air into the inner cavity of the hollow pipe before bending and forming.
4. The method for bending and forming the special-shaped hollow pipe according to claim 1, wherein when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of less than or equal to 2mm, the air pressure of the air filled into the inner cavity of the hollow pipe by the air filling device before bending and forming is 0.5Mpa to 12 Mpa.
5. The method for bending and forming the special-shaped hollow pipe according to claim 1, wherein when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of less than 0.5mm, the air pressure of air filled into the inner cavity of the hollow pipe by the air filling device before bending and forming is 0.8Mpa to 12 Mpa.
6. The method for bending and forming the special-shaped hollow pipe according to claim 1, wherein when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of 1mm to 1.5mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending and forming is 1.5Mpa to 12Mpa by the air filling device.
7. The method for bending and forming the special-shaped hollow pipe according to claim 1, wherein when the hollow pipe is an aluminum alloy hollow flat pipe with the wall thickness of 1.5mm to 2mm, the air pressure of the air filled into the inner cavity of the hollow pipe before bending and forming is 1.5Mpa to 12Mpa by the air filling device.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810960077.1A CN109175033B (en) | 2018-08-22 | 2018-08-22 | Special-shaped hollow pipe bending forming method |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810960077.1A CN109175033B (en) | 2018-08-22 | 2018-08-22 | Special-shaped hollow pipe bending forming method |
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| CN109175033A CN109175033A (en) | 2019-01-11 |
| CN109175033B true CN109175033B (en) | 2020-05-19 |
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| CN101486055A (en) * | 2007-12-27 | 2009-07-22 | 李春江 | Method for producing winding pipe of refrigerating device refrigeration evaporator of refrigerator and winding pipe device |
| CN101214516A (en) * | 2007-12-27 | 2008-07-09 | 李春江 | Technique for producing refrigeration evaporator winding pipe of refrigerator refrigerating device |
| CN205599725U (en) * | 2016-05-04 | 2016-09-28 | 重庆港乾机械有限公司 | Gasbag formula bearing structure for double tube buckles |
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