Laser-assisted rolling forming method and device for reducing springback of high-strength metal part

Abstract

The invention provides a laser-assisted rolling forming method and device for reducing springback of a high-strength metal part, and the method comprises the steps that the motion trail of a rolling tool head is designed according to the shape of a target part, and the rolling tool head rolls a to-be-machined part according to the motion trail until the target part is formed; a laser head is fixedly installed on one side of the rolling tool head, during rolling forming, the local bending area of the to-be-machined part is heated, the material forming performance is improved, and meanwhile the forming load is reduced so as to reduce springback. According to the laser-assisted rolling forming method and device for reducing resilience of the high-strength metal part, the laser head emits the laser to preheat the to-be-machined part, the to-be-machined part is subjected to rolling forming in cooperation with the rolling tool head, the to-be-formed local area is softened, and the resilience of the high-strength metal part is reduced. And the forming load is reduced, so that the high-strength metal part with smaller resilience and higher geometric accuracy is obtained, the operation is convenient, and the machining and forming effect is good.

Description

Technical Field

[0001] The present invention relates to the technical field of part processing, and particularly to a laser-assisted roll forming method and device for reducing springback of high-strength metal parts. Background Art

[0002] Due to their excellent properties, high-strength metal materials are gradually being applied in the automotive industry. Due to their high strength and low plasticity characteristics, traditional roll forming processes are generally used for the forming of high-strength metal bent parts. The roll forming process is a product processing method that uses metal sheets, strips or coils as raw materials, and bends the blank through a forming machine equipped with multiple sets of rollers with a certain number but different cross-sectional shapes to obtain a product with a uniform cross-section. Since the roll forming process is relatively complex and the manufacturing cost is high, it is suitable for mass production. For some personalized and small-batch parts with variable cross-sections, the traditional roll bending process can no longer meet the production requirements.

[0003] The roll forming process is a new sheet metal bending process developed from the roll forming process. It uses non-specialized forming tools to perform multi-pass progressive forming on the sheet metal, and can meet the manufacturing requirements of personalized customized parts. However, when the roll forming process is used to bend the sheet metal at room temperature, the target part often forms a large springback after unloading, and as the strength of the processed sheet metal increases, the springback amount will increase accordingly. This springback defect reduces the geometric accuracy of the part and limits the application of this process in the field of sheet metal forming. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a laser-assisted roll forming method and device for reducing springback of high-strength metal parts, which is used to solve the problem of low forming accuracy in the existing roll forming process.

[0005] To achieve the above purpose and other related purposes, the present invention provides a laser-assisted roll forming method for reducing springback of high-strength metal parts, including designing the movement trajectory of the roll forming tool head according to the shape of the target part, and the roll forming tool head rolling the part to be processed according to the movement trajectory until the target part is formed; fixedly installing a laser head on one side of the roll forming tool head, and heating the local bending area of the part to be processed during the roll forming process to improve the material forming performance while reducing the forming load to reduce springback.

[0006] A laser-assisted roll forming device for reducing springback of high-strength metal parts includes: A fixture for clamping the part to be processed; the part to be processed is high-strength steel or titanium alloy or aluminum alloy or magnesium alloy with a tensile strength exceeding 1000 MPa; A rolling tool head for rolling a part to be processed to form a target part; A laser head installed on one side of the rolling tool head, which moves synchronously with the rolling tool head; the laser head is configured such that the spot it emits is located at a preset distance in front of the moving direction of the rolling tool head, and is used to heat a local bending area of the part to be processed during the rolling process; the preset distance is less than 30 mm.

[0007] Preferably, a fixing component is further provided; the fixing component is used to adjust the relative position of the spot of the laser head and the end of the rolling tool head, so that when the rolling tool head and the laser head move synchronously, the spot is always at a preset distance in front of the moving direction of the rolling tool head.

[0008] Preferably, the number of the rolling tool heads is two, and the two rolling tool heads form the fixture; the laser head is installed on one side of one of the rolling tool heads.

[0009] Preferably, the fixture is a clamping fixture; the rolling tool head rolls above the fixture; the laser power of the laser head is between 600 W and 1500 W.

[0010] A laser-assisted rolling forming method for reducing the springback of high-strength metal parts, which is implemented by using the laser-assisted rolling forming device as described above, includes: Clamping the part to be processed by a fixture; Designing the movement trajectory of the rolling tool head according to the shape of the target part, and controlling the rolling tool head to perform rolling forming on the part to be processed according to the movement trajectory until the target part is formed; During the rolling forming process, heating a local bending area of the part to be processed by the laser head to reduce the springback after the part is bent and formed.

[0011] Preferably, the shape and size of the spot of the laser head are set according to the size of the bending area of the part to be processed, and are matched by adjusting the integrating mirror and the defocus amount; the spot of the laser is rectangular or circular; Preferably, the rolling rate is the same as the laser scanning rate, and the recommended value is 0.03 m / s.

[0012] As described above, the laser-assisted rolling forming method and device for reducing the springback of high-strength metal parts of the present invention preheat the part to be processed by emitting laser through the laser head, soften the local area to be formed, reduce the forming load and thereby obtain parts with smaller springback and higher geometric accuracy.

[0013] With reference to the following description and the accompanying drawings, specific embodiments of the present invention are disclosed in detail, indicating the ways in which the principles of the present invention can be employed. It should be understood that the embodiments of the present invention are not limited in scope thereby.

[0014] Features described and / or illustrated for one embodiment can be used in the same or similar way in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0015] It should be emphasized that the term "comprising / including" when used herein refers to the presence of features, wholes, steps or components, but does not exclude the presence or addition of one or more other features, wholes, steps or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 Flowchart of the laser-assisted roll forming method for reducing springback of high-strength metal parts in one embodiment of the invention; Figure 2 Relationship diagram of laser power - tool head load in one embodiment of the laser-assisted roll forming method for reducing springback of high-strength metal parts of the present invention; Figure 3 Schematic diagram of the springback angle of the part in one embodiment of the laser-assisted roll forming method for reducing springback of high-strength metal parts of the present invention; Figure 4 Composition schematic diagram of the laser-assisted roll forming device for reducing springback of high-strength metal parts in one embodiment of the present invention; Figure 5 Installation schematic diagram of the fixing component in one embodiment of the laser-assisted roll forming device for reducing springback of high-strength metal parts of the present invention; Figure 6 Composition schematic diagram of the laser-assisted roll forming device for reducing springback of high-strength metal parts of the present invention in another embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0019] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be another element in the middle. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be another element in the middle at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific implementation manners and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0021] Please refer to Figure 1 , in an embodiment of the present invention, taking an L-shaped part as an example, a laser-assisted roll forming method for reducing the springback of high-strength metal parts is provided, which includes the following steps: Step S11: Design the motion trajectory of the rolling tool head according to the shape of the target part, clamp the part to be processed through a fixture for processing operations, and use the rolling tool head to perform roll forming on the part to be processed according to the motion trajectory until the target part is formed; Specifically, according to the shape of the target part, the motion trajectory of the rolling tool head is set so that the rolling tool head can perform roll forming on the part to be processed according to the set motion trajectory. In this embodiment, a 90° bending process is completed in six passes to obtain the L-shaped target part.

[0022] Furthermore, the material of the part to be processed is a metal material with severe springback. Preferably, the material of the processed part can be a material with relatively high strength such as high-strength steel, titanium alloy, etc. or a material with relatively poor plasticity such as aluminum alloy, magnesium alloy, etc. Among them, the high-strength steel can be an ultra-high-strength steel with a tensile strength of "1180" MPa.

[0023] Step S12: Fix and install a laser head on one side of the rolling tool head. During the rolling process, heat the local bending area of the part to be processed, and reduce the forming load by means of the material softening effect at high temperature, thereby reducing the springback after bending forming.

[0024] Specifically, when processing the L-shaped target part, six bending operations are required for the part to be processed. Before each rolling pass, a laser with a certain power locally heats the area to be bent to soften the material, thereby reducing the forming load to reduce the springback of the part. The laser head is fixedly installed on one side of the rolling tool head to achieve synchronous movement, so that during the processing of the part to be processed, the auxiliary processing area is uniformly heated, the deformation resistance is reduced, and the dimensional accuracy after forming is ensured.

[0025] Further, according to the size of the target part, first adjust the integrating mirror to make the laser spot a rectangular spot, and then adjust the defocus amount to "0" mm, so as to obtain a rectangular spot with a size of "4x2" mm for processing, reducing the springback at the bending part of the L-shaped target part. Preferably, the shape of the spot can also be circular or other shapes.

[0026] Specifically, the rolling speed and the laser scanning speed can be set to a constant value of "0.03" m / s, and the laser powers are "0" W, "600" W, and "1200" W respectively, to match the processing process and obtain the forming loads under different laser powers and the corresponding L-shaped target parts. Further, as the power of the laser head increases, the load on the rolling tool head gradually decreases.

[0027] Specifically, as Figure 2 shown, it shows the relationship diagram of laser power - tool head load during the laser head assisted forming process. It can be seen from the figure that the load on the rolling tool head is the largest at room temperature, and as the laser power increases, the load on the tool head gradually decreases.

[0028] Further, different laser powers are selected, and the springback effects of the corresponding processed target parts are also different. As Figure 3 shown, at room temperature, that is, when the laser power is "0" W, there is a large springback in the target part obtained by using the laser head assisted rolling forming, and the accuracy of the target part is low. As the laser power increases to "600" W, the springback defect of the target part is significantly reduced. When the laser power increases to "1200" W, the accuracy of the target part has been significantly improved, and the springback defect is very small.

[0029] Further, the fixture for fixing the part to be processed and the clamping method need to be designed according to the shape of the target part. Specifically, for the L-shaped target part in this embodiment, a corresponding clamping fixture is set. The clamping fixture has two opposite clamping plates, and the part to be processed is fixed by the two clamping plates for processing.

[0030] Please refer to Figure 4 , in this embodiment, to realize laser-assisted roll forming to reduce springback, this embodiment provides a laser-assisted roll forming device 40 for reducing springback of high-strength metal parts, including: a roll forming tool head 41, a fixture 42, and a laser head 43. Among them, the roll forming tool head 41 is used to roll the part to be processed until it forms a target part; the fixture 42 is used to clamp the part to be processed to fix it for processing operations; the laser head 43 is used to heat the local bending area of the part to be processed during roll forming to reduce springback. Among them, the direction indicated by the dotted arrow in the figure is the moving direction of the roll forming tool head 41.

[0031] The laser-assisted roll forming device for reducing springback of parts further includes a fixing component 44. The laser head 43 is installed on one side of the roll forming tool head 41 through the fixing component 44 so that the laser head 43 moves synchronously with the roll forming tool head 41. The fixing component 44 is used to adjust the relative position of the light spot of the laser head 43 and the end of the roll forming tool head 41, so that when the roll forming tool head 41 and the laser head 43 move synchronously, the light spot is always at a preset distance in front of the moving direction of the roll forming tool head.

[0032] Specifically, as Figure 5 shown, the fixing component 44 includes a fixing rod with a clamping end. The laser head 43 is rotatably and fixedly installed on one side of the roll forming tool head 41 through the fixing component 44. One clamping end of the fixing component 44 clamps the laser head 43, and the other fixing end is fixedly installed on the roll forming tool head 41 through bolts, so that the laser head moves synchronously with the roll forming tool head. By loosening the bolts, the position of the laser head 43 can be adjusted, and after adjusting to the desired position, the bolts are tightened to fix the position of the laser head 43.

[0033] In this embodiment, the preset distance between the light spot and the roll forming tool head 41 must be as small as possible to avoid excessive heat dissipation when the roll forming tool head 41 processes the heating area.

[0034] Specifically, since the laser head 43 is fixedly installed on one side of the rolling tool head 41, the two move synchronously. Adjust the relative position between the light spot and the end of the rolling tool head 41, i.e., the processing end, so that the light spot is always "25" mm in front of the moving direction of the rolling tool head 41 to preheat and soften the area to be processed in advance.

[0035] In another embodiment as Figure 6 shown, two rolling tool heads 41 can also be used for bending processing. The laser head 43 is installed on one side of one of the rolling tool heads 41 for laser-assisted roll forming, and the other rolling tool head 41 is used to support the back of the part to be processed instead of the clamping plate to achieve the forming of small and medium batch customized and variable cross-section profile parts. The direction indicated by the dashed arrow in the figure is the moving direction of the rolling tool head 41.

[0036] In summary, the present invention uses a laser head to emit laser to preheat the sheet material, soften the local area to be formed, reduce the forming load and obtain parts with small springback and high geometric accuracy. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0037] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and many applications other than the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but should be determined by reference to the appended claims and the full scope of equivalents to which these claims are entitled. For the sake of completeness, all articles and references, including patent applications and published announcements, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to abandon such subject matter, nor should it be considered that the inventor did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A laser-assisted roll forming device for reducing springback of high-strength metal parts, characterized in that, Comprising: A fixture for clamping the part to be machined; The part to be machined is a high-strength steel or titanium alloy or aluminum alloy or magnesium alloy with a tensile strength exceeding 1000 MPa; A rolling tool head for rolling the part to be machined to form a target part; A laser head mounted on one side of the rolling tool head, which moves synchronously with the rolling tool head; the laser head is configured such that the emitted light spot is located at a preset distance in front of the moving direction of the rolling tool head, and is used to heat a local bending area of the part to be machined during the rolling forming process; the preset distance is less than 30 mm.

2. The laser-assisted rolling forming device according to claim 1, wherein A fixing component is further provided; the fixing component is used to adjust the relative position between the light spot of the laser head and the end of the rolling tool head, so that when the rolling tool head and the laser head move synchronously, the light spot is always at a preset distance in front of the moving direction of the rolling tool head.

3. The laser-assisted rolling forming device according to claim 1, characterized in that, The number of the rolling tool heads is two, and the two rolling tool heads form the fixture; the laser head is mounted on one side of one of the rolling tool heads.

4. The laser-assisted rolling forming device according to claim 1, characterized in that The fixture is a clamping fixture; the rolling tool head rolls above the fixture; the laser power of the laser head is between 600 W and 1500 W.

5. A laser-assisted roll forming method for reducing springback of high-strength metal parts, which is implemented by using the laser-assisted roll forming device according to any one of claims 1 to 4, characterized in that, Comprising: Clamping the part to be machined by a fixture; Designing the movement trajectory of the rolling tool head according to the shape of the target part, and controlling the rolling tool head to perform rolling forming on the part to be machined according to the movement trajectory until the target part is formed; During the rolling forming process, heating a local bending area of the part to be machined by a laser head to reduce the springback after the part is bent and formed.

6. The laser-assisted roll forming method according to claim 5, characterized in that, The shape and size of the light spot of the laser head are set according to the size of the bending area of the part to be machined, and are matched by adjusting the integrating mirror and the defocus amount; the light spot of the laser is rectangular or circular.

7. The laser-assisted roll forming method according to claim 5, characterized in that, The rolling rate is the same as the laser scanning rate, both being 0.03 m / s.

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