CN112474951B - Method for forming petal-shaped corrugated pipe - Google Patents
Method for forming petal-shaped corrugated pipe Download PDFInfo
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- CN112474951B CN112474951B CN202011593851.3A CN202011593851A CN112474951B CN 112474951 B CN112474951 B CN 112474951B CN 202011593851 A CN202011593851 A CN 202011593851A CN 112474951 B CN112474951 B CN 112474951B
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- lower die
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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
- B21D15/00—Corrugating tubes
- B21D15/04—Corrugating tubes transversely, e.g. helically
Abstract
The invention discloses a forming method of a petal-shaped corrugated pipe, and belongs to the technical field of metal plastic forming. The petal-shaped corrugated pipe forming method comprises the following steps: n brake lines are arranged on the unfolding material, the distance between every two adjacent brake lines in the n brake lines is matched with the half-wave unfolding length of the corrugated pipe, and n is a positive integer; placing the spread material on two lower die mandrels of a lower die forming die, and supporting the spread material through two lower die mandrel shafts, wherein the mth brake cable in n brake cables is aligned with the axis of one lower die mandrel in the two lower die mandrels, and m is an odd number larger than 1; and operating the upper die forming die to move between the two lower die mandrels, and performing brake pressing on the unfolded material until all the corrugations on the unfolded material are formed to obtain the part. The method for forming the petal-shaped corrugated pipe can form different types of petal-shaped corrugated pipes, and has the advantages of good processing flexibility, low cost, simple and reliable operation and good product size consistency.
Description
Technical Field
The invention relates to the technical field of metal plastic forming, in particular to a forming method of a petal-shaped corrugated pipe.
Background
The corrugated pipe is a pipe shell type part with flexibility, thin walls and transverse corrugations, allows large deformation under the action of axial force, transverse force and bending moment during working, and has the characteristics of large strength and flexibility. The corrugated pipe has the advantages of complex shape, high precision requirement and high surface quality requirement, the surface of the corrugated pipe is not allowed to be scratched in the forming process, the corrugated pipe is seriously scratched on the surface of the corrugated pipe after being formed by adopting a common forming die forming processing method, and the form and position tolerance hardly meets the requirement of a design drawing.
Common forming methods for corrugated tubing include hydroforming and stamping. However, the petal-shaped corrugated pipe is prepared by adopting hydraulic bulging, and the hydraulic bulging forming tool is complex in design and high in cost. The petal-shaped corrugated pipe is prepared by stamping a forming die, and materials and the die are extruded and rubbed, so that scratches are easily formed on the surface of the corrugated pipe, and the use performance of the corrugated pipe is influenced.
Disclosure of Invention
The invention provides a method for forming a petal-shaped corrugated pipe, which solves or partially solves the technical problems that in the prior art, a tool for preparing the petal-shaped corrugated pipe is complex in design, high in cost and easy to scratch the surface of the corrugated pipe, and the use performance of the corrugated pipe is influenced.
In order to solve the technical problem, the invention provides a method for forming a petal-shaped corrugated pipe, which comprises the following steps: obtaining a spread material; arranging n brake lines on the unfolding material, wherein the distance between every two adjacent brake lines in the n brake lines is matched with the half-wave unfolding length of the corrugated pipe, and n is a positive integer; placing the unfolded material on two lower die mandrels of a lower die forming die, and supporting the unfolded material through the two lower die mandrels, wherein the mth brake cable in the n brake cables is aligned with the axis of one lower die mandrel in the two lower die mandrels, and m is an odd number larger than 1; operating an upper die forming die to move between the two lower die mandrels, and performing brake pressing on the expanded material until all corrugations on the expanded material are formed to obtain a part; and connecting the parts end to obtain the petal-shaped corrugated pipe.
Further, the obtaining the spread material comprises: obtaining a petal-shaped corrugated pipe blank; and cutting the blank to obtain a spread material.
Further, the length of the spread L =2 × L1 × D + L2; the L1 is the half wave expansion length of the corrugated pipe; d is the wave number of the corrugated pipe; the L2 is the amount of overlap of the bellows.
Further, the distance between the first gate line of the n gate lines and the first side edge of the spread material is 1/2L 2; the distance between the nth gate line of the n gate lines and the second side edge of the unfolding material is 1/2L 2.
Further, the diameters of the two lower die mandrels are the same as the large-wave inner diameter of the petal-shaped corrugated pipe; the cross section of the upper die forming die is the same as the wave-shaped inner molded surface of the petal-shaped corrugated pipe.
Furthermore, the two lower die mandrels are arranged on the base; a stop block is arranged between the two lower die mandrels; and two handles are fixedly arranged at two ends of the lower die core shaft.
Further, the operating the upper die forming die to move between the two lower die mandrels includes: when an upper die forming die moves towards the position between the two lower die mandrels, stabilizing the first side of the expanded material, wherein the second side of the expanded material is in a free feeding state, the first side of the expanded material is close to the mth brake line, and the second side of the expanded material is close to the m-2 th brake line; when the upper die forming die is jointed with the two lower die mandrels, corrugations are formed.
Further, when the corrugations are formed, the corrugations are attached to a shape correction die, the attachment gap between the corrugations and the shape correction die is checked in a non-force-applying state, bench work shape correction is carried out on the gap out-of-tolerance position, and the part springback amount is eliminated; the shape correcting die is cylindrical, and the diameter of the shape correcting die is the same as the inner diameter of the petal-shaped corrugated pipe wave.
Further, the end-to-end connection of parts, the obtaining petal-shaped corrugated pipe includes: connecting the parts end to end in the length direction to form an annular workpiece; welding the head-tail joint of the parts in the length direction to obtain a petal-shaped corrugated pipe; wherein, resistance spot welding is adopted for welding, staggered spot welding is adopted for welding, and the distance between a welding point and the edge of the part is more than 1 mm.
Further, before welding the head-tail joint of the part in the length direction, the surface of the part is cleaned by adopting a chemical pickling method.
One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:
because the unfolding material is obtained, n brake pressing lines are arranged on the unfolding material, the distance between every two adjacent brake pressing lines in the n brake pressing lines is matched with the half-wave unfolding length of the corrugated pipe, n is a positive integer, the unfolding material is placed on two lower die mandrels of a lower die forming die, the unfolding material is supported by two lower die mandrel shafts, the mth brake pressing line in the n brake pressing lines is aligned with the axis of one lower die mandrel in the two lower die mandrels, m is an odd number larger than 1, the upper die forming die is operated to move towards the two lower die mandrels, the unfolding material is pressed until all corrugations on the unfolding material are formed, a part is obtained, the head and the tail of the part are connected, the petal-shaped corrugated pipe is obtained, therefore, the petal-shaped corrugated pipe is formed by the brake pressing, the surface damage in the forming process of the part can be effectively reduced, the petal-shaped corrugated pipes of different types can be formed, and the processing flexibility is good, the cost is low, the operation is simple and reliable, and the size consistency of products is good.
Drawings
Fig. 1 is a schematic structural diagram of a petal-shaped corrugated pipe forming method provided in an embodiment of the present invention;
FIG. 2 is a schematic diagram of the expanded material and the brake line of the petal-shaped corrugated pipe in the petal-shaped corrugated pipe forming method in FIG. 1;
FIG. 3 is a schematic cross-sectional view of the petal-shaped bellows spread material forming process of the petal-shaped bellows forming method of FIG. 1;
fig. 4 is a schematic view of a cross-sectional structure of the petal-shaped corrugated pipe in the height direction of the petal-shaped corrugated pipe in the forming method of the petal-shaped corrugated pipe in fig. 1;
FIG. 5 is a schematic view of a lower mold structure of a petal-shaped bellows gate pressing mold of the petal-shaped bellows forming method;
fig. 6 is a schematic structural view of an upper mold of a gate forming mold of the petal-shaped corrugated pipe in the petal-shaped corrugated pipe forming method in fig. 1;
fig. 7 is a schematic diagram of distribution of resistance welding spots of the petal-shaped metal corrugated pipe in the petal-shaped corrugated pipe forming method in fig. 1.
Detailed Description
Referring to fig. 1 to 4, a method for forming a petal-shaped corrugated pipe according to an embodiment of the present invention includes:
a spread material 1 was obtained.
Set up n floodgate lines 2 on the material that opens up, the interval between every two adjacent floodgate lines in n floodgate lines 2 matches with the half-wave expansion length of bellows, and n is the positive integer.
The unfolding material 1 is placed on two lower die mandrels 3-1 of a lower die forming die 3, and the unfolding material is supported by the two lower die mandrels 3-1, wherein the mth brake cable of n brake cables 2 is aligned with the axis of one lower die mandrel of the two lower die mandrels, and m is an odd number larger than 1.
And operating the upper die forming die 4 to move between the two lower die mandrels 3-1, and performing brake pressing on the expanded material 1 until all the corrugations 5 on the expanded material 1 are formed to obtain the part.
And connecting the parts end to obtain the petal-shaped corrugated pipe 6.
In the embodiment of the application, as the unfolding material 1 is obtained, n brake pressing lines 2 are arranged on the unfolding material, the distance between every two adjacent brake pressing lines in the n brake pressing lines 2 is matched with the half-wave unfolding length of the corrugated pipe, n is a positive integer, the unfolding material 1 is placed on two lower die mandrels 3-1 of a lower die forming die 3, the unfolding material is supported by the two lower die mandrels 3-1, wherein the mth brake pressing line in the n brake pressing lines 2 is aligned with the axis of one lower die mandrel in the two lower die mandrels, m is an odd number larger than 1, the upper die forming die 4 is operated to move towards the two lower die mandrels 3-1, the material 1 is unfolded by brake pressing until all corrugations 5 on the unfolding material 1 are formed, a part is obtained, the head and the tail of the part are connected to obtain the petal-shaped corrugated pipe 6, therefore, the petal-shaped corrugated pipe can effectively reduce the surface damage in the part forming process by brake pressing, the forming machine can form different types of petal-shaped corrugated pipes, and has the advantages of good processing flexibility, low cost, simple and reliable operation and good product size consistency.
The petal-shaped corrugated pipe 6 is made of metal, and the lower die forming die 3 and the upper die forming die 4 are installed on a brake press.
Specifically, the acquisition of the spread material 1 includes:
and (5) obtaining a petal-shaped corrugated pipe blank.
Cutting is performed on the blank to obtain a spread 1.
In the present embodiment, the spread material 1 can be obtained by cutting the blank material by laser cutting or cutting by a bench worker. Since the laser cutting is high in dimensional accuracy, laser cutting is preferable when the spread material 1 is prepared.
Length L =2 × L1 × D + L2 of the spread 1; l1 is the half wave expansion length of the bellows; d is the wave number of the corrugated pipe; l2 is the overlap margin of bellows, guarantees that the size of expansion material 1 satisfies the dimensional requirement of petal bellows 6. Wherein L2 is more than or equal to 10mm and less than or equal to 30mm, and the welding is convenient when the parts are connected end to end.
Specifically, the distance between the first gate line of the n gate lines 2 and the first side edge of the spreading material is 1/2L 2; the distance of the nth brake cable in the n brake cables and the second side edge of the unfolding material is 1/2L2, and when the parts are connected end to end, the welding is facilitated.
Referring to fig. 5-6, the diameter of the two lower die mandrels 3-1 is the same as the large-wave inner diameter of the petal-shaped corrugated pipe 6; the cross section of the upper die forming die 4 is the same as the inner profile of the petal-shaped corrugated pipe wave 6, and the corrugation 5 obtained by gate pressing meets the size requirement of the petal-shaped corrugated pipe 6.
The two lower die mandrels 3-1 are arranged on the base 7, and the two lower die mandrels 3-1 are supported by the base 7.
The two check blocks 8 are arranged between the two lower die mandrels 3-1, the number of the check blocks 8 is two, the two check blocks 8 are respectively arranged at two ends of the two lower die mandrels 3-1, and the spread material 1 is limited through the two check blocks 8.
Specifically, operating the upper die forming die to move between the two lower die mandrels includes:
when the upper die forming die 4 acts between the two lower die mandrels 3-1, the first side of the expanded material 1 is stabilized, the second side of the expanded material 1 is in a free feeding state, wherein the first side of the expanded material 1 is close to the mth brake line, and the second side of the expanded material is close to the m-2 th brake line.
Wherein, to set up the first side of exhibition material 1 steady, be about to the first side centre gripping of exhibition material 1, avoid the first side action of the material 1 of will expanding, when ripple 5 formed, whether the axis of the mth brake-pressing line in the n brake-pressing lines 2 and one of two lower mould dabbers down the mould dabber aligns, if align, ripple 5 that the surperficial brake-pressing obtained meets the requirements, if do not align, indicate ripple 5 that the brake-pressing obtained does not meet the requirements, need take the exhibition material 1 away by two lower mould dabbers 3-1, more renew the exhibition material.
When the upper die forming die 4 is attached to the two lower die mandrels 2-1, the corrugations 5 are formed, and when the brake press drives the upper die forming die 4 to move towards the space between the two lower die mandrels 3-1, the upper die forming die 4 presses the spreading material 1 downwards until the upper die forming die 4 is attached to the two lower die mandrels 2-1, and the corrugations 5 are formed.
When the corrugation 5 is formed, the corrugation 5 is attached to the shape correction die, the attachment gap between the corrugation and the shape correction die is checked in a non-force-applying state, the gap out-of-tolerance position is subjected to bench work shape correction, and the part springback amount is eliminated.
The shape correcting die is cylindrical, and the diameter of the shape correcting die is the same as the inner diameter of the petal-shaped corrugated pipe wave 6. The shape correcting die can be made of steel.
The obtained petal-shaped corrugated pipe waves 6 are ensured to meet the requirements through a combined forming method of gate pressing forming and shape correction.
Referring to fig. 7, in particular, joining the parts end to end, the resulting petaloid bellows 6 comprises:
and connecting the parts end to end in the length direction to form an annular workpiece.
And welding the head-tail joint of the parts in the length direction to obtain the petal-shaped corrugated pipe 6.
Wherein, the welding adopts resistance spot welding, and the welding adopts crisscross spot welding, and the welding spot is more than 1mm from the part edge, guarantees the structural strength of petal bellows 6.
Specifically, before welding the head-tail joint of the parts in the length direction, the surfaces of the parts are cleaned by a chemical pickling method, and the surfaces of the parts after cleaning are not allowed to have red rusty spots, unwashed white cleaning agent traces and over-corrosion phenomena. Wherein, the chemical acid cleaning agent can be hydrochloric acid, nitric acid and the like.
Specifically, the allowance in the height direction of the petal-shaped corrugated pipe 6 is physically removed, and the petal-shaped corrugated pipe 6 is further ensured to meet the size requirement by generally adopting processing methods such as bench work grinding or linear cutting.
In order to more clearly describe the embodiments of the present invention, the following description is made in terms of the method of using the embodiments of the present invention.
The petal-shaped corrugated pipe 6 has the following structural parameters: crest radius R1=31.5mm, trough radius R2=5mm, wall thickness t1=0.5mm, number of corrugations =16, bellows height 423 mm.
The half-wave expansion length L1=50.01mm of the petal-shaped corrugated pipe 6, the total length L of the expanded material 1 is 1620.32mm, and the length of the gate line 2 is L1=50.01 mm. Carrying out laser cutting blanking on the petal-shaped corrugated pipe blank to obtain an unfolded material 1, and scribing brake pressing lines on the unfolded material 1.
Installing a lower die forming die 3 and an upper die forming die 4 on a brake press, placing a spreading material 1 on two lower die mandrels 3-1 of the lower die forming die 3, and supporting the spreading material through the two lower die mandrels 3-1, wherein the mth brake press line in n brake press lines 2 is aligned with the axis of one lower die mandrel in the two lower die mandrels, and m is an odd number larger than 1. The first side of the expanded material 1 is stabilized, and the second side of the expanded material 1 is in a free feeding state.
And starting a brake press, enabling an upper die forming die 4 to act between two lower die mandrels 3-1, carrying out brake pressing on the expanded material 1 until all corrugations 5 on the expanded material 1 are formed, separating the upper die forming die 4 and the upper die forming die 3, and taking out the part.
And (3) fitting the part with a shape correcting mould, wherein the shape correcting mould is in a steel pipe shape, and the diameter size of the shape correcting mould is the same as the waveform inner diameter of the petal-shaped corrugated pipe 6. During shape correction, the shape correction die is attached to the petal-shaped corrugated pipe 6, the attaching gap between the petal-shaped corrugated pipe 6 and the shape correction die is checked in a non-force-applying state, and the gap out-of-tolerance position is corrected by bench workers to eliminate the part springback amount.
The method comprises the steps of connecting parts in the length direction end to end into a tubular part, adopting resistance spot welding for welding, wherein the welding scrap amount is 20mm, the welding spot needs to control the interval, adopting staggered spot welding, and the distance between the welding spot and the edge of the part needs to be more than 1 mm.
Finally, it should be noted that the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.
Claims (7)
1. A method of forming a petal-shaped corrugated tube, comprising:
obtaining a spread material;
arranging n brake lines on the unfolding material, wherein the distance between every two adjacent brake lines in the n brake lines is matched with the half-wave unfolding length of the corrugated pipe, and n is a positive integer;
placing the unfolded material on two lower die mandrels of a lower die forming die, and supporting the unfolded material through the two lower die mandrels, wherein the mth brake cable in the n brake cables is aligned with the axis of one lower die mandrel in the two lower die mandrels, and m is an odd number larger than 1;
operating an upper die forming die to move between the two lower die mandrels, and performing brake pressing on the expanded material until all corrugations on the expanded material are formed to obtain a part;
connecting the parts end to obtain a petal-shaped corrugated pipe;
the diameters of the two lower die mandrels are the same as the large-wave inner diameter of the petal-shaped corrugated pipe;
the cross section of the upper die forming die is the same as the waveform inner molded surface of the petal-shaped corrugated pipe;
the operation of the upper die forming die to act between the two lower die mandrels comprises the following steps:
when an upper die forming die moves towards the position between the two lower die mandrels, stabilizing the first side of the expanded material, wherein the second side of the expanded material is in a free feeding state, the first side of the expanded material is close to the mth brake line, and the second side of the expanded material is close to the m-2 th brake line;
When the upper die forming die is attached to the two lower die mandrels, corrugations are formed;
when the corrugations are formed, the corrugations are attached to a shape correction die, the attachment gaps between the corrugations and the shape correction die are checked in a non-force-applying state, the gap out-of-tolerance position is subjected to bench work shape correction, and the part springback amount is eliminated;
the correction mould is cylindrical, and the diameter size of the correction mould is the same as the inner diameter of the petal-shaped corrugated pipe wave.
2. The method of forming petaloid corrugated tube according to claim 1, wherein the obtaining the spread comprises:
obtaining a petal-shaped corrugated pipe blank;
and cutting the blank to obtain a spread material.
3. The method of forming a petal-shaped bellows according to claim 2, wherein:
the length of the spread L =2 x L1 x D + L2;
the L1 is the half wave expansion length of the corrugated pipe;
d is the wave number of the corrugated pipe;
the L2 is the amount of overlap of the bellows.
4. The method of forming a petal-shaped bellows according to claim 3, wherein:
the distance between the first gate line of the n gate lines and the first side edge of the unfolded material is 1/2L 2;
the distance between the nth gate line of the n gate lines and the second side edge of the unfolding material is 1/2L 2.
5. The method of forming a petal-shaped bellows according to claim 1, wherein:
the two lower die mandrels are arranged on the base;
a stop block is arranged between the two lower die mandrels;
and two handles are fixedly arranged at two ends of the lower die core shaft.
6. The method of claim 1, wherein the joining the parts end-to-end to obtain a petal-shaped corrugated tube comprises:
connecting the parts end to end in the length direction to form an annular workpiece;
welding the head-tail joint of the parts in the length direction to obtain a petal-shaped corrugated pipe;
wherein, resistance spot welding is adopted for welding, staggered spot welding is adopted for welding, and the distance between a welding point and the edge of the part is more than 1 mm.
7. The method of forming a petal-shaped bellows according to claim 6, wherein:
before welding the head-tail joint of the part in the length direction, cleaning the surface of the part by adopting a chemical pickling method.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011593851.3A CN112474951B (en) | 2020-12-29 | 2020-12-29 | Method for forming petal-shaped corrugated pipe |
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| CN202011593851.3A CN112474951B (en) | 2020-12-29 | 2020-12-29 | Method for forming petal-shaped corrugated pipe |
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| CN112474951B true CN112474951B (en) | 2022-07-29 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1117408A (en) * | 1994-12-17 | 1996-02-28 | 奚生林 | Method and equipment for mfg. metallic spiral corrugated pipe |
| CN109284539B (en) * | 2018-08-30 | 2022-11-04 | 沈阳云仿科技有限公司 | Method for optimizing size and technological parameters of hydraulic or pneumatic forming die of U-shaped corrugated pipe |
| CN109013813B (en) * | 2018-09-03 | 2023-09-05 | 西安飞机工业（集团）有限责任公司 | Adjustable eccentric reducing taper pipe gate press forming die and forming method |
| CN109108129B (en) * | 2018-10-15 | 2019-09-24 | 西北工业大学 | A kind of pipe axis pressing formation method of bellows |
| CN109570920B (en) * | 2018-11-20 | 2020-07-03 | 四川航天中天动力装备有限责任公司 | Machining method for base body of wave-lobe diffuser |
| CN110523833B (en) * | 2019-07-18 | 2020-12-01 | 燕山大学 | One-way extension compensation Y-shaped corrugated pipe, forming device and forming method |
| CN111438223B (en) * | 2020-04-03 | 2022-06-03 | 西安石油大学 | Integral forming method for rectangular metal corrugated pipe |
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