Partition cold deformation method and device for complex forge piece

Abstract

The invention discloses a partitioned cold deformation method and device for a complex forge piece, and belongs to the technical field of material machining, the method comprises the following steps: a, the forge piece is partitioned, a first lug piece used for clamping the forge piece is arranged on one side of the forge piece, and a second lug piece used for clamping the forge piece is arranged on the other side of the forge piece; b, a forge piece is placed on a lower die, and a first lug piece and a second lug piece are pressed and fixed through a lower die pressing plate; and c, the lower die is moved, the to-be-cold-pressed area of the forge piece is moved to the area corresponding to the upper die, and subarea cold pressing is conducted in sequence. Through rigid fixing of the lug and dynamic displacement of the lower die, full-area accurate positioning of the complex forge piece under one-time clamping is achieved, the problems of unstable clamping of irregular shapes and repeated positioning errors are effectively solved, and efficient and uniform reduction of the residual stress of the complex forge piece is achieved through partitioned cold pressing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material processing, and in particular to a partitioned cold deformation method and device for complex forgings. BACKGROUND

[0002] The traditional method for reducing the quenching residual stress of aluminum alloy rib plate forgings is to use a mold to exert a downward longitudinal stress on the top of the rib, causing a small elastic or plastic deformation of the top of the rib, and the deformation is transmitted along the force direction to the high stress concentration area at the bottom of the rib, causing a small elastic or plastic deformation of the area, so that the initial high stress is reduced and redistributed. However, the effect of compressing the top of the rib to deform the bottom of the rib will decrease with the increase of the height of the rib, reducing the residual stress reduction effect; if the deformation amount of the mold on the rib top is increased, it is easy to cause excessive plastic deformation of the rib top, and the round corner at the connection between the rib and the web will be unstable, and the deformation will not only fail to be efficiently transmitted to the stress concentration area, but also new stress concentration will be generated at the bottom round corner.

[0003] A step-by-step cold pressing device for reducing the residual stress of free forgings and a cold pressing method thereof are disclosed in Chinese patent document CN118621112A, published on September 10, 2024, which includes a workbench, a cold pressing structure installed at the top end of the workbench, a heating assembly provided on one side of the cold pressing structure, the heating assembly including a heating box provided on one side of the cold pressing structure, the heating box being fixedly installed at the top end of the workbench, heating wires being installed on the inner wall of the heating box, baffles being provided on both sides of the heating box, the two baffles being slidably connected with the heating box through a moving assembly, a dust suction assembly being provided inside the heating box, and a transmission belt being provided at the bottom end of the heating box and installed inside the workbench.

[0004] The step-by-step cold pressing device for reducing the residual stress of free forgings and the cold pressing method thereof disclosed in the patent document can place the workpiece in the heating box before step-by-step cold pressing of the workpiece, heat it through the heating wires, reduce the deformation resistance of the material during cold pressing, reduce the generation of residual stress, and improve the quality and service life of the workpiece. However, there are still problems of local stress concentration and profile mutation, which are not suitable for cold pressing of complex forgings. SUMMARY

[0005] In order to overcome the defects of the prior art, the present application provides a partitioned cold deformation method and device for complex forgings, which realizes precise positioning of all areas under one-time clamping of complex forgings through rigid fixation of the ear piece and dynamic displacement of the lower mold, effectively solves the problems of unstable clamping and repeated positioning errors of irregular shapes, and realizes efficient and uniform reduction of residual stress of complex structure forgings through partitioned cold pressing.

[0006] The present application is realized through the following technical solutions: A partitioned cold deformation method of a complex forging piece, characterized in comprising the following steps: a. Partitioning the forging piece, a first lug for clamping the forging piece is arranged on one side of the forging piece, and a second lug for clamping the forging piece is arranged on the other side of the forging piece; b. Placing the forging piece on the lower die, and pressing and fixing the first lug and the second lug with the lower die pressing plate; c. Moving the lower die, moving the area to be cold-pressed of the forging piece to the area corresponding to the upper die, and sequentially performing partitioned cold pressing.

[0007] In the step a, the partitioning of the forging piece refers to dividing the forging piece into multiple cold-pressed areas.

[0008] In the step a, the width of the first lug and the second lug is greater than 100 mm.

[0009] In the step b, the pressing and fixing of the first lug and the second lug with the lower die pressing plate refers to placing the first lug and the second lug between the lower die pressing plate and the lower die, and fixing the lower die pressing plate and the lower die through the fixing screws.

[0010] In the step c, the cold-pressed deformation amount of the partitioned cold pressing is controlled within the range of 0.5-3.0%.

[0011] In the step c, when the partitioned cold pressing is performed, the adjacent cold-pressed areas have an overlapping area of 10-30%.

[0012] A partitioned cold deformation device of a complex forging piece, comprising an upper die and a lower die, characterized in further comprising a lower die pressing plate, the upper die comprises an upper die base and an upper die insert, the upper die insert is fixed on the upper die base, and the lower die pressing plate is fixed on the lower die.

[0013] The upper die is provided with a wedge-shaped groove.

[0014] The upper die insert is provided with a wedge-shaped boss matched with the wedge-shaped groove.

[0015] The wedge-shaped boss is two, one wedge-shaped boss is located on one side of the upper die insert, and the other wedge-shaped boss is located on the other side of the upper die insert, and the wedge-shaped boss is integrally formed with the upper die insert.

[0016] The beneficial effects of the present application mainly include the following aspects: Firstly, the present application realizes the accurate positioning of the whole area under the one-time clamping of the complex forging piece through the rigid fixation of the lug and the dynamic displacement of the lower die, effectively solves the problems of unstable clamping and repeated positioning errors of irregular shapes, and realizes the efficient and uniform reduction of residual stress of the complex structure forging piece through partitioned cold pressing.

[0017] Secondly, the forging is divided into multiple cold pressing areas, the deformation area is discretized, the single cold pressing load and the material stress concentration are significantly reduced, and the problem that the residual stress reduction rate is not enough due to the overall deformation of the large and complex forging caused by equipment overload can be avoided.

[0018] Thirdly, in step c, the cold pressing deformation amount of the partitioned cold pressing is controlled in the range of 0.5-3.0%, the internal residual stress of the material is greatly reduced while ensuring the initiation of effective plastic deformation to realize shape correction.

[0019] Fourthly, in step c, when the partitioned cold pressing is performed, the adjacent cold pressing areas have an overlapping area of 10-30%, the deformation of the adjacent cold pressing areas can be smoothly transitioned, the undeformed band and stress mutation can be eliminated, the overall deformation uniformity, shape contour accuracy and surface continuity of the forging are significantly improved, and the risk of residual stress concentration is reduced.

[0020] Fifthly, the upper die includes an upper die base and an upper die insert, the upper die insert is fixed on the upper die base, and the lower die pressing plate is fixed on the lower die, so that the equipment load requirement and cost are reduced, efficient and accurate multiple partitioned cold pressing is realized, the quenching residual stress is effectively reduced, and subsequent machining is facilitated.

[0021] Sixthly, the upper die insert is provided with a wedge-shaped boss matched with the wedge-shaped groove, the displacement or vibration of the upper die insert in the cold pressing process is completely eliminated through the rigid self-locking structure of the wedge-shaped boss and the wedge-shaped groove, and the stability of the forming accuracy under high load is ensured.

[0022] Seventhly, the wedge-shaped boss is two, one wedge-shaped boss is located on one side of the upper die insert, and the other wedge-shaped boss is located on the other side of the upper die insert, the wedge-shaped boss is integrally formed with the upper die insert, the reliability in the cold pressing process can be further ensured, and the forming accuracy under ultra-high load is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] The application will be further specifically described below in combination with the drawings in the specification and specific embodiments: Figure 1 A schematic view of the forging cold-pressed by the segmented cold deformation device of the application; Figure 2 A schematic view of the forging of the application; Marked in the figure: 1, forging, 2, first ear, 3, second ear, 4, lower die, 5, upper die, 6, lower die pressing plate, 7, upper die base, 8, upper die insert, 9, wedge-shaped boss. DETAILED DESCRIPTION

[0024] Example 1 See Figure 1 and Figure 2A partitioned cold deformation method of a complex forging piece, comprising the following steps: a. Partitioning the forging piece 1, a first lug 2 for clamping the forging piece 1 is arranged on one side of the forging piece 1, and a second lug 3 for clamping the forging piece 1 is arranged on the other side of the forging piece 1; b. Placing the forging piece 1 on the lower die 4, and pressing and fixing the first lug 2 and the second lug 3 with the lower die pressing plate 6; c. Moving the lower die 4, moving the area of the forging piece 1 to be cold-pressed to the area corresponding to the upper die 5, and sequentially performing partitioned cold pressing.

[0025] This embodiment is the most basic implementation, which realizes the accurate positioning of the whole area of the complex forging piece 1 under one-time clamping through the rigid fixation of the lug and the dynamic displacement of the lower die 4, effectively solves the problems of unstable clamping and repeated positioning errors of irregular shapes, and realizes the efficient and uniform reduction of residual stress of the complex structure forging piece 1 through partitioned cold pressing.

[0026] Embodiment 2 Referring to Figure 1 and Figure 2 A partitioned cold deformation method of a complex forging piece, comprising the following steps: a. Partitioning the forging piece 1, a first lug 2 for clamping the forging piece 1 is arranged on one side of the forging piece 1, and a second lug 3 for clamping the forging piece 1 is arranged on the other side of the forging piece 1; b. Placing the forging piece 1 on the lower die 4, and pressing and fixing the first lug 2 and the second lug 3 with the lower die pressing plate 6; c. Moving the lower die 4, moving the area of the forging piece 1 to be cold-pressed to the area corresponding to the upper die 5, and sequentially performing partitioned cold pressing.

[0027] Preferably, in the step a, the partitioning of the forging piece 1 refers to dividing the forging piece 1 into multiple cold-pressed areas.

[0028] In the step a, the width of the first lug 2 and the second lug 3 is 120 mm.

[0029] In the step b, the pressing and fixing of the first lug 2 and the second lug 3 with the lower die pressing plate 6 refers to placing the first lug 2 and the second lug 3 between the lower die pressing plate 6 and the lower die 4, and fixing the lower die pressing plate 6 and the lower die 4 through fixing screws.

[0030] In the step c, the cold deformation amount of the partitioned cold pressing is controlled at 0.5% of the material yield strength.

[0031] In the step c, when performing the partitioned cold pressing, the adjacent cold-pressed areas have an overlapping area of 10%.

[0032] The embodiment is a preferred embodiment, which divides the forging 1 into multiple cold pressing regions, significantly reduces the single cold pressing load and material stress concentration by discretizing the deformation region, and can avoid the problem that the residual stress reduction rate is not enough due to the overall deformation of the large and complex forging 1 caused by equipment overload.

[0033] Embodiment 3 Referring to Figure 1 and Figure 2 A partitioned cold deformation method of a complex forging, comprising the following steps: a. Partitioning the forging 1, a first ear 2 for clamping the forging 1 is arranged on one side of the forging 1, and a second ear 3 for clamping the forging 1 is arranged on the other side of the forging 1; b. Placing the forging 1 on the lower die 4, and pressing and fixing the first ear 2 and the second ear 3 with the lower die pressing plate 6; c. Moving the lower die 4 to move the region of the forging 1 to be cold pressed to the region corresponding to the upper die 5, and sequentially performing partitioned cold pressing.

[0034] In the step a, the partitioning of the forging 1 refers to dividing the forging 1 into multiple cold pressing regions.

[0035] In the step a, the width of the first ear 2 and the second ear 3 is greater than 130mm.

[0036] In the step b, the pressing and fixing of the first ear 2 and the second ear 3 with the lower die pressing plate 6 refers to placing the first ear 2 and the second ear 3 between the lower die pressing plate 6 and the lower die 4, and fixing the lower die pressing plate 6 and the lower die 4 through fixing screws.

[0037] In the step c, the cold pressing deformation amount of the partitioned cold pressing is controlled to be 3.0% of the material yield strength.

[0038] In the step c, when performing partitioned cold pressing, the adjacent cold pressing regions have an overlapping region of 30%.

[0039] The embodiment is another preferred embodiment, which ensures to initiate effective plastic deformation to realize shape correction, while significantly reducing the internal residual stress of the material. It can ensure smooth transition of deformation of adjacent cold pressing regions, eliminate un-deformed bands and stress mutations, thereby significantly improving the overall deformation uniformity, shape contour accuracy and surface continuity of the forging 1, and reducing the risk of residual stress concentration.

[0040] Embodiment 4 Referring to Figure 1 and Figure 2 A partitioned cold deformation device of a complex forging, comprising an upper die 5, a lower die 4 and a lower die pressing plate 6, the upper die 5 comprises an upper die base 7 and an upper die insert 8, the upper die insert 8 is fixed on the upper die base 7, and the lower die pressing plate 6 is fixed on the lower die 4.

[0041] This embodiment is another preferred implementation. The upper mold 5 includes an upper mold base 7 and an upper mold insert 8. The upper mold insert 8 is fixed on the upper mold base 7, and the lower mold pressure plate 6 is fixed on the lower mold 4. This not only reduces the equipment load requirements and costs, but also achieves efficient and precise multi-zone cold pressing, thereby effectively reducing quenching residual stress and facilitating subsequent machining.

[0042] Example 5 See Figure 1 and Figure 2 A partitioned cold deformation device for complex forgings includes an upper die 5, a lower die 4 and a lower die pressure plate 6. The upper die 5 includes an upper die base 7 and an upper die insert 8, with the upper die insert 8 fixed on the upper die base 7. The lower die pressure plate 6 is fixed on the lower die 4.

[0043] Preferably, the upper mold 5 has a wedge-shaped groove.

[0044] The upper mold insert 8 is provided with a wedge-shaped boss 9 that matches the wedge-shaped groove.

[0045] This embodiment is another preferred implementation. The upper mold insert 8 is provided with a wedge-shaped boss 9 that matches the wedge-shaped groove. Through the rigid self-locking structure of the wedge-shaped boss 9 and the wedge groove, the displacement or vibration of the upper mold insert 8 during the cold pressing process is completely eliminated, ensuring the stability of the forming accuracy under high load.

[0046] Example 6 See Figure 1 and Figure 2 A partitioned cold deformation device for complex forgings includes an upper die 5, a lower die 4 and a lower die pressure plate 6. The upper die 5 includes an upper die base 7 and an upper die insert 8, with the upper die insert 8 fixed on the upper die base 7. The lower die pressure plate 6 is fixed on the lower die 4.

[0047] The upper mold 5 has a wedge-shaped groove.

[0048] The upper mold insert 8 is provided with a wedge-shaped boss 9 that matches the wedge-shaped groove.

[0049] There are two wedge-shaped protrusions 9. One wedge-shaped protrusion 9 is located on one side of the upper mold insert 8, and the other wedge-shaped protrusion 9 is located on the other side of the upper mold insert 8. The wedge-shaped protrusions 9 and the upper mold insert 8 are integrally formed.

[0050] This embodiment is another preferred implementation. There are two wedge-shaped bosses 9. One wedge-shaped boss 9 is located on one side of the upper mold insert 8, and the other wedge-shaped boss 9 is located on the other side of the upper mold insert 8. The wedge-shaped bosses 9 and the upper mold insert 8 are integrally formed, which can further ensure the reliability of the cold pressing process and further improve the forming accuracy under ultra-high load.

[0051] The basic principle of this invention is as follows: Due to the irregular shape of complex forgings, traditional clamping methods are prone to loosening or uneven force distribution. By symmetrically designing the first lug 2 and the second lug 3 on both sides of the forging 1, and cooperating with the lower die plate 6, rigid clamping is achieved. Since the cold pressing of the parts requires repeated force application, the lug design can ensure the overall positioning stability and avoid displacement or vibration of the forging 1 during the cold pressing process. Furthermore, the overall cold pressing is decomposed into local sequential deformation. By moving the lower die 4, the area of ​​the forging 1 to be cold pressed is aligned with the upper die 5 segment by segment, which can reduce the amount of deformation per time, avoid material damage, adapt to the deformation requirements of complex curved surfaces, and solve the problem of difficulty in one-time forming of large or irregular forgings. By cold pressing adjacent areas with 10-30% overlap, abrupt changes in the joint can be eliminated, ensuring the continuity of deformation. By moving the lower die 4, rather than moving the forging 1 or the upper die 5, the forging 1 can always be locked on the lower die 4 by the lower die plate 6, avoiding repeated clamping errors. Moreover, by only moving the lower die 4 to adjust the position, the consistency of the force direction can be maintained, ensuring that the deformation of each segment is uniform and controllable.

[0052] The present invention can also provide upper mold guide pin holes on the upper mold 5 and lower mold guide pin holes on the lower mold 4. The upper mold guide pin holes and lower mold guide pin holes can be matched sequentially for positioning different partition modules. The upper mold guide pin holes and lower mold guide pin holes are numbered accordingly. Movable guide pins are provided on the upper mold 5. After the movable guide pins are inserted into the lower mold guide pin holes, they are fixed with pins. The movable guide pins are aligned with the upper mold guide pin holes with the same number, which can be used to accurately determine the mold position and achieve the centering of the upper mold 5 and the lower mold 4 without misalignment.

Claims

1. A method for zoned cold deformation of complex forgings, characterized in that, Includes the following steps: a. The forging (1) is divided into sections. A first ear piece (2) for clamping the forging (1) is provided on one side of the forging (1), and a second ear piece (3) for clamping the forging (1) is provided on the other side of the forging (1). b. Place the forging (1) on the lower die (4) and press and fix the first ear piece (2) and the second ear piece (3) with the lower die pressure plate (6); c. Move the lower die (4) to move the area of ​​the forging (1) to be cold-pressed to the area corresponding to the upper die (5), and perform cold pressing in sections in sequence.

2. The method for partitioned cold deformation of complex forgings according to claim 1, characterized in that: In step a, the forging (1) partitioning refers to dividing the forging (1) into multiple cold-pressed areas.

3. The method for partitioned cold deformation of complex forgings according to claim 1, characterized in that: In step a, the width of the first ear piece (2) and the second ear piece (3) is greater than 100mm.

4. The method for partitioned cold deformation of complex forgings according to claim 1, characterized in that: In step b, pressing and fixing the first ear piece (2) and the second ear piece (3) with the lower mold platen (6) means placing the first ear piece (2) and the second ear piece (3) between the lower mold platen (6) and the lower mold (4), and fixing the lower mold platen (6) and the lower mold (4) with fixing screws.

5. The method for partitioned cold deformation of complex forgings according to claim 1, characterized in that: In step c, the cold pressing deformation of the partitioned cold pressing is controlled within the range of 0.5-3.0%.

6. The method for partitioned cold deformation of complex forgings according to claim 1, characterized in that: In step c, when performing zoned cold pressing, adjacent cold pressing areas have a 10-30% overlap.

7. A partitioned cold deformation device for complex forgings, comprising an upper die (5) and a lower die (4), characterized in that: It also includes a lower mold platen (6), the upper mold (5) includes an upper mold base (7) and an upper mold insert (8), the upper mold insert (8) is fixed on the upper mold base (7), and the lower mold platen (6) is fixed on the lower mold (4).

8. The partitioned cold deformation device for complex forgings according to claim 7, characterized in that: The upper mold (5) has a wedge-shaped groove.

9. A partitioned cold deformation device for complex forgings according to claim 8, characterized in that: The upper mold insert (8) is provided with a wedge-shaped boss (9) that matches the wedge-shaped groove.

10. A partitioned cold deformation device for complex forgings according to claim 9, characterized in that: There are two wedge-shaped bosses (9). One wedge-shaped boss (9) is located on one side of the upper mold insert (8), and the other wedge-shaped boss (9) is located on the other side of the upper mold insert (8). The wedge-shaped boss (9) and the upper mold insert (8) are integrally formed.

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