Cold deformation drawing die for T-shaped slender arc-shaped aluminum alloy forgings

Abstract

The invention relates to the field of manufacturing of aluminum alloy forgings, in particular to a cold deformation drawing die for T-shaped slender arc-shaped aluminum alloy forgings. Comprising an upper die and a lower die, sliding rods are arranged at the two ends of the upper die, and an inclination angle of 10-20 degrees is formed between the axial direction of each sliding rod and the pressing direction; the lower die is provided with an outwards-protruding arc surface used in cooperation with the lower surface of a forge piece, the arc surface is provided with an avoiding groove used for containing a reinforcing rib in the circumferential direction of the arc surface, guide grooves are formed in the two ends of the upper surface of the lower die, first guide pieces are arranged on the two side walls of the guide grooves, and the extending direction of the first guide pieces is consistent with the extending direction of the arc surface. The guide grooves are internally provided with sliding blocks, the sliding blocks are provided with second guide pieces used in cooperation with the first guide pieces, the sliding blocks are provided with sliding holes used in cooperation with the sliding rods, and the opposite faces of the two sliding blocks are each provided with an L-shaped buckle. Uniform plastic deformation of the forge piece is generated in the length direction through stretching, uniform deformation of the forge piece in the length direction is achieved, and the residual stress reduction effect is remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of aluminum alloy forging manufacturing, in particular to a cold deformation stretching die for a T-shaped elongated arc-shaped aluminum alloy forging. Background Art

[0002] 7 series aluminum alloys are widely used in aircraft structural parts due to their high strength and good corrosion resistance. In the production process of 7050 die forgings, quenching is an essential process. After quenching, residual stress will be generated inside the 7050 aluminum alloy die forgings. In the subsequent parts processing, the release and redistribution of residual stress inside the forgings will cause parts processing deformation. Therefore, 7050 aluminum alloy die forgings for aviation usually use cold deformation process to reduce residual stress.

[0003] for Figure 1 The T-shaped slender arc aluminum alloy die forging shown in the figure includes an arc plate, and the center of the lower surface of the arc plate has a reinforcing rib arranged along the length of the arc plate. Due to its poor structural rigidity, the residual stress is more sensitive to the processing of the part. Due to the limitations of the forging shape and pressing tonnage, the poor uniformity of the cold deformation of the forging leads to uneven residual stress reduction. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a T-shaped slender arc-shaped aluminum alloy forging cold deformation stretching die for eliminating the residual stress of the forging.

[0005] The technical solution adopted by the present invention to solve the technical problem is a T-shaped elongated arc aluminum alloy forging cold deformation stretching die, comprising an upper die and a lower die, wherein sliding rods are provided at both ends of the upper die, and the axial direction of the sliding rod forms an inclination angle of 10° to 20° with the pressing direction;

[0006] The lower die is provided with an outwardly convex arc surface used in conjunction with the lower surface of the forging, and the arc surface is provided with avoidance grooves for placing reinforcing ribs along its circumference. Guide grooves are provided at both ends of the upper surface of the lower die, and first guide members are provided on the two side walls of the guide groove. The extension direction of the first guide member is consistent with the extension direction of the arc surface. A slider is provided in the guide groove, and a second guide member used in conjunction with the first guide member is provided on the slider. A sliding hole used in conjunction with the slide rod is provided on the slider, and L-shaped buckles are provided on the opposite surfaces of the two sliders.

[0007] Furthermore, grooves are arranged radially along the arc surface on both sides of the top end of the arc surface, and the depth of the grooves is 20-50 mm.

[0008] Furthermore, the first guide member is a dovetail block, and the second guide member is a dovetail groove.

[0009] Furthermore, an avoidance hole is provided at the bottom of the guide groove, and the slide rod can move up and down in the avoidance hole.

[0010] Furthermore, the inner side of the buckle is provided with anti-skid tooth patterns, the tooth pitch of the anti-skid tooth patterns is 2 to 5 mm, and the tooth depth is 0.5 to 1 mm.

[0011] Furthermore, the cross section of the slide rod is square or circular, and the ratio of the cross section size to the cross section thickness of the forging is 1:1.2-1.5.

[0012] Furthermore, the contact point between the sliding rod and the upper die is rounded, and the radius of the fillet is R20 to R50 mm.

[0013] The beneficial effects of the present invention are as follows: by arranging slide bars at both ends of the upper die, the slide bars are designed with an inclination angle of 10° to 20°. During the vertical pressing process of the press machine, the inclination angle of the slide bars decomposes the vertical pressing force into a horizontal tensile force, forcing the slide bars on both sides to slide outward synchronously along the guide groove of the lower die. The L-shaped buckles of the slide bars are tightly buckled with the two ends of the forging, ensuring that the tensile force is evenly transmitted to the entire length of the forging. The present invention causes the forging to produce uniform plastic deformation along the length direction through axial stretching, realizes uniform deformation in the length direction of the forging, and significantly improves the residual stress reduction effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic diagram of a forging;

[0015] Figure 2 It is a schematic diagram of the structure of the present invention;

[0016] Figure 3 It is a schematic diagram of the connection between the slide bar and the slider;

[0017] Figure 4 It is a schematic diagram of the present invention when used.

[0018] Figure numerals: 1-upper die; 2-lower die; 3-slide rod; 4-arc surface; 5-avoidance groove; 6-guide groove; 7-first guide member; 8-slider; 9-sliding hole; 10-clip; 11-groove; 12-avoidance hole; 13-forging; 14-boss. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0020] like Figure 2-Figure 4As shown, the present invention is a T-shaped slender arc-shaped aluminum alloy forging cold deformation stretching die, including an upper die 1 and a lower die 2, wherein slide bars 3 are provided at both ends of the upper die 1, and the axial direction of the slide bar 3 forms an inclination angle of 10° to 20° with the pressing direction; wherein the slide bar 3 and the upper die 1 are both made of steel, and the slide bar 3 can be integrally formed with the upper die 1 or welded, and the slide bar 3 is located on the lower surface of the upper die 1, and the distance from the upper end of the slide bar 3 to the center line of the upper die 1 is smaller than the distance from the upper end of the slide bar 3 to the center line of the upper die 1, thereby ensuring that the axial direction of the slide bar 3 forms an inclination angle of 10° to 20° with the pressing direction.

[0021] The lower die 2 is provided with an outwardly convex arc surface 4 used in conjunction with the lower surface of the forging 13, and the arc surface 4 is provided with an avoidance groove 5 for placing reinforcing ribs along its circumference. Guide grooves 6 are provided at both ends of the upper surface of the lower die 2, and first guide members 7 are provided on the two side walls of the guide groove 6. The extension direction of the first guide member 7 is consistent with the extension direction of the arc surface 4. A slider 8 is provided in the guide groove 6, and a second guide member used in conjunction with the first guide member 7 is provided on the slider 8. A sliding hole 9 used in conjunction with the slide rod 3 is provided on the slider 8, and L-shaped buckles 10 are provided on the opposite surfaces of the two sliders 8. During use, the lower surface of the forging 13 is fitted with the arc surface 4, and the reinforcing ribs are placed in the avoidance groove 5; the cross-section of the guide groove 6 is rectangular, and the bottom surface of the guide groove 6 has the same curvature as the arc surface 4. The two side walls of the guide groove 6 are provided with first guide members 7, which can be T-shaped blocks connected to the side walls of the guide groove 6 by welding. The extension direction of the first guide member 7 is consistent with the extension direction of the arc surface 4, so that the moving direction of the slider 8 is consistent with the stretching direction of the forging 13, ensuring the quality of subsequent forming of the forging 13; the cross-section of the slider 8 is rectangular, and the second guide member is a T-shaped slot that cooperates with the first guide member 7. The slider 8 is arranged in this way so that it can move along the arrangement direction of the first guide member 7. The slider 8 is provided with a sliding hole 9 used in conjunction with the slide rod 3. The axis of the sliding hole 9 is parallel to the axis of the slide rod 3. The inclination angle of the slide rod 3 decomposes the vertical pressing force into a tensile force along the direction of the first guide member 7, thereby forcing the forging 13 to extend; L-shaped buckles 10 are provided on the opposite surfaces of the two sliders 8. In actual use, a rectangular boss 14 is provided on the upper surface of the forging 13, and the boss 14 is placed inside the buckle 10 so that the buckle 10 clamps the boss 14, so that the forging 13 can be driven to stretch when the slider 8 moves.

[0022] In order to reduce the friction between the arc surface 4 and the lower surface of the forging 13, further, grooves 11 are arranged radially along the arc surface 4 on both sides of the top of the arc surface 4, and the depth of the grooves 11 is 20-50mm. In this way, only the two ends and the middle area contact the lower surface of the forging 13, reducing the contact area to reduce the friction resistance, so that the forging 13 can be better stretched.

[0023] As a preferred embodiment, further, see Figure 3 The first guide member 7 is a dovetail block, and the second guide member is a dovetail groove.

[0024] In order to achieve a longer stretching distance, see Figure 3 The bottom of the guide groove 6 is provided with an avoidance hole 12, and the slide bar 3 can move up and down in the avoidance hole 12. The cross section of the avoidance hole 12 is rectangular or circular, and the length of the slide bar 3 is greater than the length of the sliding hole 9, so that when the top end of the slide bar 3 slides out of the sliding hole 9, the slide bar 3 can continue to move downward, thereby driving the slider 8 to move and increasing the stretching length of the forging 13.

[0025] In order to prevent the forging 13 from moving relative to the buckle 10 during the stretching process, the buckle 10 is further provided with anti-skid teeth on the inner side, and the anti-skid teeth have a tooth pitch of 2 to 5 mm and a tooth depth of 0.5 to 1 mm.

[0026] In order to ensure the strength of the slide bar 3, the cross section of the slide bar 3 is further square or circular, and the ratio of the cross section size to the cross section thickness of the forging 13 is 1:1.2-1.5. For example, the thickness of the forging 13 is 50 mm, and the square or circular cross section size (side length or diameter) of the slide bar 3 is 60-75 mm. The ratio of 1:1.2-1.5 can ensure that the slide bar 3 has sufficient impact resistance and prevent the slide bar 3 from breaking early.

[0027] In order to reduce stress concentration at the connection between the slide bar 3 and the upper die 1, further, the contact between the slide bar 3 and the upper die 1 is rounded, and the fillet radius is R20 to R50 mm.

[0028] The specific operation process of the present invention is as follows: the quenched 7050 aluminum alloy forging 13 is placed on the arc surface 4 of the lower die 2, and lubricating oil is applied to the arc surface 4 and the guide groove 6, and the buckle 10 clamps the boss 14 on the forging 13. The slide bar 3 is inserted into the sliding hole 9 on the slider 8, the press is started, the upper die 1 is pressed down at a constant speed, and the slide bar 3) pushes the slider 8 to slide outward along the extension direction of the first guide 7, and the forging 13 is stretched until the forging 13 is stretched to the target deformation amount. The press stops working, the upper die 1 is kept for 10 to 30 seconds and then unloaded, and the forging 13 is taken out.

[0029] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die, comprising an upper die (1) and a lower die (2), characterized in that: Slide bars (3) are provided at both ends of the upper die (1), and the axial direction of the slide bar (3) forms an inclination angle of 10° to 20° with the pressing direction; The lower die (2) is provided with an outwardly convex arc surface (4) for use with the lower surface of the forging, and the arc surface (4) is provided with an avoidance groove (5) for placing reinforcing ribs along its circumference. The upper surface of the lower die (2) is provided with guide grooves (6) at both ends, and the two side walls of the guide groove (6) are provided with a first guide member (7), and the extension direction of the first guide member (7) is consistent with the extension direction of the arc surface (4). A slider (8) is provided in the guide groove (6), and a second guide member (7) for use with the first guide member (7) is provided on the slider (8). The slider (8) is provided with a sliding hole (9) for use with the slide rod (3), and L-shaped buckles (10) are provided on the opposite surfaces of the two sliders (8).

2. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die as claimed in claim 1, characterized in that: Grooves (11) are arranged radially along the arc surface (4) on both sides of the top end of the arc surface (4), and the depth of the grooves (11) is 20-50 mm.

3. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die as claimed in claim 1, characterized in that: The first guide member (7) is a dovetail block, and the second guide member is a dovetail groove.

4. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die as claimed in claim 3, characterized in that: The bottom of the guide groove (6) is provided with an avoidance hole (12), and the slide bar (3) can move up and down in the avoidance hole (12).

5. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die as claimed in claim 1, characterized in that: The buckle (10) is provided with anti-skid tooth patterns on the inner side, the anti-skid tooth patterns have a tooth pitch of 2 to 5 mm and a tooth depth of 0.5 to 1 mm.

6. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die as claimed in claim 1, characterized in that: The cross section of the sliding rod (3) is square or circular, and the ratio of the cross section size to the cross section thickness of the forging is 1:1.2-1.

5.

7. A T-shaped elongated arc aluminum alloy forging cold deformation stretching die as claimed in claim 6, characterized in that: The contact point between the slide bar (3) and the upper die (1) is rounded, and the radius of the rounded corner is R20 to R50 mm.

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