Rigid filling press bending forming device and method for magnesium alloy monolithic wallboard

Abstract

The present application relates to a kind of magnesium alloy whole wallboard rigid filling press bending forming device and method, device includes upper die plate and lower die plate, upper die plate lower surface is connected with male die backing plate, male die pressing plate, bending male die in order;Bending male die lower end passes through male die pressing plate and is opposite to bending female die;The lower end of bending male die is rigid filling boss, and bending male die is integral or split type structure;The side surface of each protruding boss of rigid filling boss is inclined surface;Lower die plate upper surface is fixed with female die fixed plate, and strip-shaped recess is provided in the top of female die fixed plate, and bending female die is embedded in strip-shaped recess;Along the width direction of the left-right symmetry surface in female die fixed plate, temperature measuring thermocouple insertion hole is formed;Multiple heating holes are formed on the two sides of temperature measuring thermocouple insertion hole.The present application reduces the occurrence of magnesium alloy grid whole wallboard skin surface concave defect, rib buckling defect, rib collapse defect, improves magnesium alloy grid whole wallboard component size precision.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnesium alloy integral wallboard processing, and particularly relates to a magnesium alloy integral wallboard rigid filling press bending forming device and method, which can process magnesium alloy integral wallboard components with high quality, high precision and large size. BACKGROUND

[0002] Integral wallboard is a very important large shell component on various aerospace vehicles. Currently, the commonly used integral wallboard materials mainly include titanium alloy and high-strength aluminum alloy. As the natural resources of light metal materials such as titanium and aluminum are decreasing year by year and the cost is increasing year by year, it is urgent to develop new materials to replace titanium alloy and high-strength aluminum alloy materials to meet the demand for large integral wallboard components in the aerospace field. The metal magnesium resources in China are very rich, far superior to titanium and aluminum. In addition, the density, strength, stiffness and some other physical performance indicators of magnesium alloy materials can meet the performance indicators of integral wallboard components in aerospace equipment. Therefore, in the field of aerospace, magnesium alloy materials will be an important substitute material for titanium alloy and high-strength aluminum alloy, and will be widely used.

[0003] The relevant literature discusses the effect and related technical features of aluminum alloy integral wallboard press bending forming, including a non-filling press bending forming method and a soft filling press bending forming method. When aluminum alloy wallboard is press bent or roll bent, the rubber filling press bending forming method effectively improves the size precision of the aluminum alloy wallboard. However, when magnesium alloy integral wallboard is press bent, the main defect forms of the magnesium alloy integral wallboard are skin surface concave defects, rib buckling instability deformation, and rib shoulder collapse defects. Controlling the generation of magnesium alloy wallboard defects is one of the important technical problems in magnesium alloy wallboard press bending forming. Since the plastic forming performance of magnesium alloy material is low, the magnesium alloy integral wallboard blank needs to be heated and the forming die needs to be preheated. Therefore, the filling materials used in the soft filling processing methods described in the literature cannot meet the performance requirements of the filling materials during magnesium alloy integral wallboard press bending forming, and the defect control effect on the magnesium alloy wallboard is not obvious. Therefore, the present application provides a rigid filling press bending forming device and method. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a magnesium alloy integral wallboard rigid filling press bending forming device and method to reduce the occurrence of magnesium alloy grid integral wallboard skin surface concave defects, rib buckling defects, and rib collapse defects, and improve the size precision of magnesium alloy grid integral wallboard components.

[0005] The device comprises an upper die and a lower die, the upper die comprises an upper die plate, the lower surface of the upper die plate is sequentially connected with a punch pad plate, a punch pressing plate and a bending punch, the punch pad plate is fixed on the upper die plate through fixed bolts II, the punch pressing plate fixes the bending punch on the punch pad plate through fixed bolts I, the lower end of the bending punch penetrates through the punch pressing plate and is opposite to a bending concave die of the lower die, the lower end of the bending punch is a rigid filling boss, which is an integral structure or a split structure with the bending punch, the side surface of each protruding boss in the rigid filling boss is an inclined surface with an inclination of 10-15°, the upper surface of the lower die plate is fixed with a concave die fixing plate, a strip-shaped groove is formed on the top of the concave die fixing plate, and a bending concave die is embedded in the strip-shaped groove, a temperature measuring thermocouple insertion hole is formed on the left-right symmetrical surface of the concave die fixing plate along the width direction, and a plurality of heating holes are formed on the two sides of the temperature measuring thermocouple insertion hole.

[0006] The rigid filling boss comprises a plurality of protruding bosses, which are force applying ends of the bending forming.

[0007] The plurality of protruding bosses are arranged side by side and correspond to the grid slots of the whole wall plate respectively.

[0008] The height of the boss is h1, which is equal to the height t2 of the rib, i.e. h1=t2, the root width of the boss is s2, which is equal to the rib spacing b0, i.e. s2=b0, and the boss spacing s3 is equal to the rib shoulder width b1, i.e. s3=b1.

[0009] A groove is formed on the punch pad plate, and the upper end of the bending punch is fixed in the groove; a rectangular counterbore is formed in the middle of the punch pressing plate, and the shaft shoulder of the upper end of the bending punch abuts against the stepped surface of the rectangular counterbore of the punch pressing plate.

[0010] The bending concave die is U-shaped, the internal height h of the bending concave die is the reduction height during the bending forming, the inner width s of the bending concave die is (2n-1)(b0+b1), n is a positive integer, n≥2, the larger the value of n is, the lower the machining precision is, and the higher the production efficiency is; the smaller the value of n is, the higher the machining precision is, and the lower the production efficiency is; by controlling the reduction height h and the inner width s of the bending concave die, magnesium alloy whole wall plates with different curvature radii can be processed; by replacing the bending concave dies with different inner width sizes, magnesium alloy wall plates with different grid sizes can be processed.

[0011] A magnesium alloy whole wall plate rigid filling bending forming method, which adopts the magnesium alloy whole wall plate rigid filling bending forming device, comprises the following steps:

[0012] Step one: install the electric heating rod in the heating hole, heat the electric heating rod to make the bending concave die reach a preheating temperature T1 and keep the temperature for 10 minutes; at the same time, install the temperature measuring thermocouple in the temperature measuring thermocouple insertion hole to monitor the real-time temperature of the bending concave die;

[0013] Step two: the magnesium alloy whole wallboard blank is heated to a forming temperature T in a heating furnace and kept for 10 minutes;

[0014] Step three: the heated magnesium alloy whole wallboard blank is placed on the bending die device to perform the first press bending forming;

[0015] Specifically, the heated magnesium alloy whole wallboard blank is placed on the bending concave die, the third row of grid slots on the right side of the wallboard blank is aligned with the boss of the press bending convex die, the wallboard blank is fixed on the plane of the bending concave die by hand, then the press machine is started, the press bending convex die starts the downward stroke according to the preset pressing speed V, after the boss of the convex die contacts the grid slots of the wallboard, the wallboard press bending forming process starts, until the pressing height h reaches the preset value, the press bending convex die stops the downward stroke, then the press machine is controlled to start the return stroke of the press bending convex die, until the boss of the convex die is separated from the grid slots of the wallboard, the first press bending forming is completed;

[0016] Step four: the magnesium alloy whole wallboard blank after the first press bending forming is moved along the horizontal direction to the right on the surface of the bending concave die, the moving distance is the progressive press bending forming feed amount Δu, the second press bending forming is performed according to the method and parameters of step three; the feed amount Δu = m(b0+b1), m is a positive integer, m≥1; the larger the value of m is, the lower the processing precision is and the higher the production efficiency is; the smaller the value of m is, the higher the processing precision is and the lower the production efficiency is; b0 is the rib spacing of the wallboard component, and b1 is the rib shoulder width of the wallboard component;

[0017] Step five: step four is repeated, the number of press bending M1 is determined according to the total number of grids M in the wallboard arc direction, the value of m in the progressive press bending forming feed amount Δu = m(b0+b1), and the value of n in the inside width s = (2n-1)(b0+b1) of the bending concave die, M1 = [M-2(n-1)] / m, M1, M, m, and n are all positive integers; after M1 times of press bending forming are completed, the magnesium alloy whole wallboard component is taken out, and the magnesium alloy whole wallboard component with large size and equal curvature shape is processed.

[0018] The preheating temperature T1 of the press bending concave die is 150-180℃.

[0019] The forming temperature T is 260-280℃.

[0020] The rigid filling boss at the lower end of the press bending convex die is fixed with the press bending convex die through the bolt IV when the press bending convex die and the press bending concave die are in a split structure.

[0021] The beneficial effects of the present application are:

[0022] 1. The rigid filling of the present application is realized by the rigid filling boss on the bending punch, convenient operation, simple structure;

[0023] 2. The rigid filling is realized by the rigid filling boss, and the control defect effect is good;

[0024] 3. After the integral wallboard bending forming is finished, the rigid filling boss on the punch directly separates from the integral wallboard part, avoiding the complex cleaning process of the filler in the wallboard grid slot, and improving the production efficiency;

[0025] The present application effectively controls the generation of magnesium alloy integral wallboard defects, significantly improves the product quality and size accuracy, and achieves good results. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the rigid filling bending forming process principle diagram for magnesium alloy integral wallboard; (wherein: s is the inside width of the bending die, h is the pressing height during the bending forming, and △u is the progressive bending forming feed amount);

[0027] Figure 2 It is the wallboard structure diagram and size definition;

[0028] Figure 3 It is the front view of the rigid filling bending forming device provided by the present application for magnesium alloy integral wallboard, (wherein: s is the inside width of the bending die, h is the pressing height during the bending forming, and △u is the progressive bending forming feed amount);

[0029] Figure 4 It is the side view of Figure 3 ;

[0030] Figure 5 It is the front view of the bending punch in the bending device provided by example 1 of the present application;

[0031] Figure 6 It is the side view of Figure 5 ;

[0032] Figure 7 It is the front view of the rigid filling boss structure in the present application; (wherein: h1 is the boss height, equal to the rib height, that is, h1=t2; s1 is the boss shoulder width; s2 is the boss root width, equal to the rib spacing, that is, s2=b0; the boss side slope is 10-15°);

[0033] Figure 8 It is the side view of Figure 7 ; (wherein: h1 is the boss height, equal to the rib height, that is, h1=t2; s1 is the boss shoulder width; s2 is the boss root width, equal to the rib spacing, that is, s2=b0; s3 is the boss spacing, equal to the rib shoulder width, that is, s3=b1).

[0034] Figure 9 The main view of the split rigid filling boss in the press bending device provided for the embodiment 1 of the present application;

[0035] Figure 10 The side view of Figure 9 ;

[0036] Figure 11 The main view of the magnesium alloy whole wall plate blank structure provided for the embodiment 1 of the present application;

[0037] Figure 12 The side view of Figure 11 ;

[0038] Figure 13 The plan view of Figure 11 ;

[0039] Figure 14 The structure diagram of the magnesium alloy whole wall plate structure;

[0040] Wherein,

[0041] 1 upper die plate, 2 punch pad, 3 fixed bolt I, 4 punch pressing plate, 5 press bending punch, 6 bending die, 7 die fixing plate, 8 heating hole, 9 temperature measuring thermocouple insertion hole, 10 lower die plate, 11 whole wall plate blank, 12 fixed bolt II, 13 fixed bolt III, 14 rigid filling boss, 15 split rigid filling boss, 16 fixed bolt IV. DETAILED DESCRIPTION

[0042] In order to better explain the present application, so as to be understood, the technical scheme and effect of the present application are described in detail by specific embodiments in combination with the accompanying drawings.

[0043] Embodiment 1

[0044] As Figure 3As shown, a rigid filling bending forming device for a magnesium alloy integral wall panel includes an upper mold and a lower mold. The upper mold includes an upper template 1, a punch pad 2, a punch pressure plate 4, and a bending punch 5. The lower mold includes a bending die 6, a die fixing plate 7, and a lower template 10. The punch pad 2, punch pressure plate 4, and bending punch 5 are sequentially connected below the upper template 1. The punch pad 2 is fixed to the upper template 1 by fixing bolts II12. The punch pressure plate 4 fixes the bending punch 5 to the punch pad 2 by fixing bolts I3. The lower end of the bending punch 5 passes through the punch pressure plate 4 and is opposite to the bending die 6. The lower end of the bending punch 5 is a rigid filling boss 14, which is an integral structure with the bending punch 5 and includes multiple protruding bosses as the bending forming force application end. The punch pad 2 has a groove, and the upper end of the bending punch 5 is fixed in the groove; the punch pressure plate 4 has a rectangular countersunk hole in the middle, and the shoulder of the upper end of the bending punch 5 abuts against the stepped surface of the rectangular countersunk hole on the punch pressure plate 4 to ensure accurate positioning of the bending punch 5.

[0045] The multiple protruding bosses are arranged side by side, each corresponding to a mesh groove in the overall wall panel, such as... Figure 4 As shown. The number of bosses is the same as the number of grid slots in the generatrix direction of the wall panel. Since there are four grid slots in the generatrix direction of the wall panel blank in this embodiment, the bending punch 5 is designed with four protruding bosses.

[0046] like Figures 5-8 As shown, in the rigid filling boss 14, the side of each protruding boss is a slope with an angle of 10°. Its function is to automatically align the rigid filling boss 14 on the bending die 5 with the overall wall panel's grid groove, and simultaneously facilitate demolding of the overall wall panel after bending. Figure 2 As shown, the boss height is h1, which is equal to the rib height t2, i.e., h1=t2; the boss shoulder width is s1; the boss root width is s2, which is equal to the rib spacing b0, i.e., s2=b0; the boss spacing is s3, which is equal to the rib shoulder width b1, i.e., s3=b1.

[0047] A die fixing plate 7 is fixed to the lower template 10 by fixing bolts III13. A strip-shaped groove is formed on the top of the die fixing plate 7, and a bending die 6 is embedded within the groove. The bending die 6 has a U-shaped structure, and its internal height h is the pressing height during bending. By controlling the pressing height h and the inner width s of the die, magnesium alloy integral wall panels with different radii of curvature can be processed. By replacing the bending die 6 with different inner width dimensions, magnesium alloy integral wall panels with different grid sizes can be processed.

[0048] During the bending forming of the magnesium alloy integral wall panel, the rigid filling boss 14 on the bending punch 5 contacts the grid groove of the integral wall panel. On the press, the bending forming process of the magnesium alloy integral wall panel is realized through the external force of the upper template 1, the punch pad 2, and the bending punch 5, thus producing a high-precision and high-quality magnesium alloy integral wall panel.

[0049] On the left and right symmetrical surfaces of the die fixing plate 7, there are thermocouple insertion holes 9 along its width direction for installing thermocouples to measure the preheating temperature of the bending die 6. Multiple heating holes 8 are provided on both sides of the thermocouple insertion holes 9 for installing electric heating rods to heat the bending die 6; in this embodiment, two heating holes 8 are provided on each side of the thermocouple insertion holes 9.

[0050] This embodiment provides an AZ31 magnesium alloy mesh-type integral wall panel blank 11, the structure and dimensions of which are as follows: Figures 11-13 As shown, the overall panel dimensions are 205mm × 105mm × 9mm, with an overall panel thickness (t0) of 9mm, a rib height (t2) of 5mm, an overall panel skin thickness (t1) of 4mm, a rib spacing (b0) of 20mm, and a rib shoulder width (b1) of 5mm. The progressive bending forming process parameters for the magnesium alloy mesh-type overall panel include a forming temperature T of 260℃, a die preheating temperature T1 of 180℃, a reduction height h of 3mm, and an inner die width s of 75mm. The progressive bending forming feed rate Δu is 25mm, and the reduction speed V is 2mm / s. The theoretical value of the overall panel curvature radius r provided in this embodiment is 235.88mm.

[0051] Combination Figure 1 The schematic diagram of the rigid filling bending forming process shows that the above-mentioned rigid filling bending forming device for magnesium alloy integral wall panels is used for bending forming, and the specific steps include:

[0052] Step 1: Install the electric heating rod in the heating hole 8, turn on the electric heating rod to heat the bending die 6 to the preheating temperature T1 = 180℃, and keep it at that temperature for 10 minutes; at the same time, install the temperature measuring thermocouple in the temperature measuring thermocouple socket 9 to monitor the real-time temperature of the bending die 6.

[0053] Step 2: Heat the magnesium alloy integral wall panel blank 11 in a heating furnace to the forming temperature T = 260℃ and hold it at that temperature for 10 minutes.

[0054] Step 3: Place the heated magnesium alloy integral wall panel blank 11 on the bending die device for the first bending forming, with a bending height of h = 3mm.

[0055] Specifically, the heated magnesium alloy overall wallboard blank 11 is placed on the bending die 6, the second row of grid slots on the right side of the overall wallboard blank 11 is aligned with the four bosses of the bending punch 5, the overall wallboard blank 11 is fixed on the plane of the bending die 6 by hand, then the press is started, the bending punch 5 starts to move downward at a preset pressing speed of 2 mm / s, after the rigid filling boss contacts the grid slot of the overall wallboard blank 11, the wallboard bending forming process starts, until the pressing height reaches 3 mm, the downward movement of the bending punch 5 is stopped, then the press is controlled to start the return movement of the bending punch 5, until the rigid filling boss is separated from the wallboard grid slot, and the first bending forming is completed.

[0056] Step four: the magnesium alloy overall wallboard blank 11 after the first bending forming is moved horizontally to the right on the surface of the bending die 6, the moving distance is the progressive bending feeding amount Δu = 25 mm, and the second bending forming is performed according to the method and parameters of step three;

[0057] Step five: step four is repeated, and the bending forming is performed for 6 times until the bending forming is completed, that is, the overall wallboard blank is completely bent, and no further bending forming is required; the magnesium alloy overall wallboard part is taken out, and a large-size magnesium alloy overall wallboard part with a constant curvature shape is processed, as shown in FIG. 6. Figure 14

[0058] The vernier caliper method is used to measure the curvature radius of the wallboard part after the bending forming, and the result is 236.23 mm, and the ruler method is used to measure the absolute concave deviation Δh of the wallboard skin surface, and the result is 0.04 mm, which meets the technical requirement of 0.08 mm.

[0059] Example 2

[0060] The difference between this example and example 1 is that some parameters are different, the AZ31 magnesium alloy grid overall wallboard blank provided in this example has the structure and size that the overall wallboard blank size is 205 mm x 105 mm x 9 mm, the overall wallboard thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wallboard skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive bending forming process parameters of the magnesium alloy grid overall wallboard include a forming temperature (T) of 260°C, a die preheating temperature (T1) of 180°C, a pressing height (h) of 5 mm, and an inner side width (s) of the die of 75 mm. The progressive bending forming feeding amount (Δu) is 25 mm, and the pressing speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wallboard provided in this example is 143.12 mm. The rest of the settings and methods are the same as those of example 1.

[0061] ​The curvature radius of the wall plate component after the press bending forming of the example is measured by the vernier caliper method to be 143.43 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by the ruler method to be 0.06 mm, which meets the technical requirement of 0.08 mm.

[0062] Example 3

[0063] The difference between the example and example 1 is that some parameters are different. The AZ31 magnesium alloy net format overall wall plate blank provided by the example has the structure and size that the overall wall plate size is 205 mm x 105 mm x 9 mm, the overall wall plate thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wall plate skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive press bending forming process parameters of the magnesium alloy net format overall wall plate include that the forming temperature (T) is 260 ℃, the die preheating temperature (T1) is 180 ℃, the press-down height (h) is 7 mm, and the concave mold inside width (s) is 75 mm. The progressive press bending feed amount (Δu) is 25 mm, and the press-down speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wall plate provided by the example is 103.95 mm. The rest of the settings and methods are the same as those of example 1.

[0064] The curvature radius of the wall plate component after the press bending forming of the example is measured by the vernier caliper method to be 104.22 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by the ruler method to be 0.07 mm, which meets the technical requirement of 0.08 mm.

[0065] Example 4

[0066] The difference between the example and example 1 is that some parameters are different. The AZ31 magnesium alloy net format overall wall plate blank provided by the example has the structure and size that the overall wall plate size is 205 mm x 105 mm x 9 mm, the overall wall plate thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wall plate skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive press bending forming process parameters of the magnesium alloy net format overall wall plate include that the forming temperature (T) is 260 ℃, the die preheating temperature (T1) is 180 ℃, the press-down height (h) is 9 mm, and the concave mold inside width (s) is 75 mm. The progressive press bending feed amount (Δu) is 25 mm, and the press-down speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wall plate provided by the example is 82.63 mm. The rest of the settings and methods are the same as those of example 1.

[0067] The curvature radius of the wall plate component after the press bending forming of the example is measured by the vernier caliper method to be 82.87 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by the ruler method to be 0.08 mm, which meets the technical requirement of 0.08 mm.

[0068] Example 5

[0069] The difference between the example and the example 1 is that some parameters are different. The AZ31 magnesium alloy net format overall wall plate blank provided by the example has the structure and size that the overall wall plate size is 205 mm x 105 mm x 9 mm, the overall wall plate thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wall plate skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive press bending forming process parameters of the magnesium alloy net format overall wall plate include that the forming temperature (T) is 270 ℃, the die preheating temperature (T1) is 150 ℃, the press-down height (h) is 3 mm, and the concave mold inside width (s) is 75 mm. The progressive press bending feed amount (Δu) is 25 mm, and the press-down speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wall plate provided by the example is 235.88 mm. The rest of the settings and methods are the same as those of the example 1.

[0070] The curvature radius of the wall plate component after the press bending forming of the example is measured by the vernier caliper method to be 236.21 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by the ruler method to be 0.03 mm, which meets the technical requirement of 0.08 mm.

[0071] Example 6

[0072] The difference between the example and the example 1 is that some parameters are different. The AZ31 magnesium alloy net format overall wall plate blank provided by the example has the structure and size that the overall wall plate size is 205 mm x 105 mm x 9 mm, the overall wall plate thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wall plate skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive press bending forming process parameters of the magnesium alloy net format overall wall plate include that the forming temperature (T) is 270 ℃, the die preheating temperature (T1) is 150 ℃, the press-down height (h) is 5 mm, and the concave mold inside width (s) is 75 mm. The progressive press bending feed amount (Δu) is 25 mm, and the press-down speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wall plate provided by the example is 143.12 mm. The rest of the settings and methods are the same as those of the example 1.

[0073] The curvature radius of the wall plate component after the press bending forming of the example is measured by the vernier caliper method to be 143.41 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by the ruler method to be 0.05 mm, which meets the technical requirement of 0.08 mm.

[0074] Example 7

[0075] The difference between the example and the example 1 is that some parameters are different. The AZ31 magnesium alloy net format overall wall plate blank provided by the example has the structure and size that the overall wall plate size is 205 mm x 105 mm x 9 mm, the overall wall plate thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wall plate skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive press bending forming process parameters of the magnesium alloy net format overall wall plate include that the forming temperature (T) is 280 ℃, the die preheating temperature (T1) is 160 ℃, the press-down height (h) is 7 mm, and the concave mold inside width (s) is 75 mm. The progressive press bending feeding amount (Δu) is 25 mm, and the press-down speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wall plate provided by the example is 103.95 mm. The rest of the settings and methods are the same as those of the example 1.

[0076] The curvature radius of the wall plate component after the press bending forming of the example is measured by the vernier caliper method to be 104.23 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by the ruler method to be 0.06 mm, which meets the technical requirement of 0.08 mm.

[0077] Example 8

[0078] The difference between the example and the example 1 is that some parameters are different. The AZ31 magnesium alloy net format overall wall plate blank provided by the example has the structure and size that the overall wall plate size is 205 mm x 105 mm x 9 mm, the overall wall plate thickness (t0) is 9 mm, the rib height (t2) is 5 mm, the overall wall plate skin thickness (t1) is 4 mm, the rib spacing (b0) is 20 mm, and the rib shoulder width (b1) is 5 mm. The progressive press bending forming process parameters of the magnesium alloy net format overall wall plate include that the forming temperature (T) is 280 ℃, the die preheating temperature (T1) is 170 ℃, the press-down height (h) is 9 mm, and the concave mold inside width (s) is 75 mm. The progressive press bending feeding amount (Δu) is 25 mm, and the press-down speed (V) is 2 mm / s. The theoretical value r of the curvature radius of the overall wall plate provided by the example is 82.63 mm. The rest of the settings and methods are the same as those of the example 1.

[0079] The curvature radius of the wall plate component after the press bending forming in the embodiment is measured by using the vernier caliper method to be 82.85 mm, and the absolute concave deviation Δh of the wall plate skin surface is measured by using the ruler method to be 0.07 mm, which meets the technical requirement of 0.08 mm.

[0080] In the present application, the rigid filling is realized by the rigid filling bosses 14 on the press bending punch 5, and the size of the bosses corresponds to the size of the overall wall plate grid slot. During the press bending forming of the magnesium alloy overall wall plate, the rigid filling bosses 14 on the press bending punch 5 are in contact with the overall wall plate grid slot, and the bosses play a role of rigid filling. The rigid filling bosses 14 exert a radial compressive stress on the inner surface of the overall wall plate skin in the overall wall plate grid slot, effectively control the inward deformation of the skin surface, and reduce the inward defect of the skin surface of the overall wall plate.

[0081] During the press bending forming of the magnesium alloy overall wall plate, the rigid filling bosses 14 on the press bending punch 5 are in contact with the side wall of the overall wall plate grid slot. Due to the role of rigid filling, a lateral compressive stress is generated on the side of the rib, and the lateral movement of the rib is constrained, effectively controlling the buckling deformation of the rib and reducing the buckling defect of the rib.

[0082] During the press bending forming of the magnesium alloy overall wall plate, the press bending forming force is realized by the joint action of the rib shoulder and the bottom of the overall wall plate grid slot to complete the press bending forming process of the overall wall plate. Due to the role of rigid filling, the rigid filling bosses 14 on the press bending punch 5 are in contact with the bottom of the overall wall plate grid slot, so that the surface of the rib shoulder and the inner surface of the overall wall plate skin are both stress surfaces, the distribution area of the press bending deformation force is increased, the force acting on the rib shoulder is reduced, and the collapse defect of the rib is avoided.

[0083] During the press bending forming of the magnesium alloy grid overall wall plate, due to the role of rigid filling, the size of the rigid filling boss 14 is the same as the initial size of the magnesium alloy grid overall wall plate blank, so that the size accuracy of the magnesium alloy grid overall wall plate component can be effectively improved.

[0084] Example 9

[0085] As shown in Figures 9-10 The difference between the embodiment and example 1 is that the rigid filling boss and the press bending punch 5 in the embodiment are in a split structure, that is, the rigid filling boss in the embodiment is a split rigid filling boss 15, which is connected and fixed with the press bending punch 5 through the fixing bolt IV 16, and the rest of the settings and parameters are the same as those in example 1. The split rigid filling boss has the advantages of convenient replacement and easy processing of wall plates with different grid sizes.

[0086] The curvature radius of the wall plate part after the press bending forming in the embodiment is measured by using the vernier caliper method to be 236.24 mm, and the absolute concave deviation △h of the wall plate skin surface is measured by using the ruler method to be 0.04 mm, which meets the technical requirement of 0.08 mm.

[0087] In order to prove that the rigid filling press bending forming method provided in the application improves the measurement accuracy, the implementation of the non-filling press bending forming method is also completed in Embodiments 1-4. The size accuracy of the wall plate obtained by using the rigid filling press bending forming method and the non-filling press bending forming method is compared, and the results are shown in Table 1.

[0088] Table 1 Measurement results of the absolute concave deviation (△h / mm) of the wall plate skin surface provided in Embodiments 1-4

[0089]

[0090] According to the measurement results shown in Table 1, when the rigid filling press bending forming method is used, the absolute concave deviation (△h) of the wall plate skin surface is in the range of 0.04 mm-0.08 mm; and when the non-filling press bending forming method is used, the absolute concave deviation (△h) of the wall plate skin surface is in the range of 0.18 mm-0.26 mm. Obviously, compared with the non-filling press bending forming method, the rigid filling press bending forming method improves the size accuracy of the wall plate by more than 2 times.

Claims

1. A magnesium alloy monocoque panel rigid fill press bending forming apparatus characterized by: The upper die and the lower die are included, the upper die includes an upper die plate, the upper die plate is sequentially connected with a male die backing plate, a male die pressing plate and a bending male die from bottom to top, the male die backing plate is fixed on the upper die plate through fixed bolts II, the male die pressing plate fixes the bending male die on the male die backing plate through fixed bolts I, the lower end of the bending male die penetrates through the male die pressing plate and is opposite to a bending female die of the lower die, the lower end of the bending male die is a rigid filling boss and is an integral structure or a split structure with the bending male die, the side surface of each protruding boss in the rigid filling boss is an inclined surface with an inclination of 10-15°, the upper surface of the lower die plate is fixed with a female die fixing plate, a strip-shaped groove is formed in the top of the female die fixing plate, and a bending female die is embedded in the strip-shaped groove, a temperature measuring thermocouple insertion hole is formed in the left-right symmetrical surface of the female die fixing plate along the width direction of the female die fixing plate, and a plurality of heating holes are formed on the two sides of the temperature measuring thermocouple insertion hole.

2. A rigidly filled press bending forming device for magnesium alloy monocoque wall panels according to claim 1, characterised in that: The rigid filling boss includes a plurality of protruding bosses and is used as a pressing and bending forming force applying end.

3. A rigidly filled press bending forming apparatus for magnesium alloy monocoque wall panels according to claim 2, wherein: The plurality of protruding bosses are arranged side by side and correspond to the whole wall plate grid slots respectively.

4. A rigidly filled press bending forming apparatus for magnesium alloy unit wall panels according to claim 3, characterized in that: The boss height h1 is equal to the rib height t2, i.e. h1=t2, the boss root width s2 is equal to the rib spacing b0, i.e. s2=b0, and the boss spacing s3 is equal to the rib shoulder width b1, i.e. s3=b1.

5. A rigidly filled press bending forming apparatus for magnesium alloy monocoque panels according to claim 1, wherein: A groove is formed in the male die backing plate, and the upper end of the bending male die is fixed in the groove; a rectangular counterbore is formed in the middle of the male die pressing plate, and the shaft shoulder of the upper end of the bending male die abuts against the stepped surface of the rectangular counterbore of the male die pressing plate.

6. A rigidly filled press bending forming apparatus for magnesium alloy unit wall panels according to claim 4, wherein: The bending female die is U-shaped, the inner height h of the bending female die is the pressing height during the pressing and bending forming, the inner width s of the bending female die is (2n-1)(b0+b1), n is a positive integer, n≥2, the larger the value of n is, the lower the machining precision is and the higher the production efficiency is, the smaller the value of n is, the higher the machining precision is and the lower the production efficiency is, different curvature radius magnesium alloy whole wall plates can be machined by controlling the pressing height h and the inner width s of the bending female die, and different grid size magnesium alloy wall plates can be machined by replacing the bending female die with different inner width sizes.

7. The rigidly filled press-bend forming apparatus for magnesium alloy monocoque panels of claim 1, wherein: When the rigid filling boss of the lower end of the bending male die is in a split structure with the bending male die, the rigid filling boss and the bending male die are fixed together through a bolt IV.

8. A rigid filler press bending method of a magnesium alloy integrated wall panel using the magnesium alloy integrated wall panel rigid filler press bending device according to claim 1, characterized in that, Specifically includes the following steps: Step one: install the electric heating rod in the heating hole, heat the electric heating rod to make the bending female die reach a preheating temperature T1 and keep the temperature for 10 minutes; at the same time, install the temperature measuring thermocouple in the temperature measuring thermocouple insertion hole to monitor the real-time temperature of the bending female die; Step two: heat the magnesium alloy whole wall plate blank in the heating furnace to a forming temperature T and keep the temperature for 10 minutes; Step three: place the heated magnesium alloy whole wall plate blank on the pressing and bending die device to perform the first pressing and bending forming; Specifically, the heated magnesium alloy whole wallboard blank is placed on the bending die, the third row of grid slots on the right side of the wallboard blank is aligned with the boss of the bending punch, the wallboard blank is fixed on the plane of the bending die by hand, then the press is started, the bending punch starts to move downward at the preset pressing speed V, the boss of the punch contacts the grid slots of the wallboard after the downward movement, and the wallboard bending forming process starts, until the pressing height h reaches the preset value, the downward movement of the bending punch is stopped, then the press is controlled to start the return movement of the bending punch, until the boss of the punch is separated from the grid slots of the wallboard, and the first bending forming is completed; Step four: the magnesium alloy whole wallboard blank after the first bending forming is moved horizontally to the right on the surface of the bending die, the moving distance is the progressive bending forming feed amount Δu, and the second bending forming is performed according to the method and parameters of step three; The feed amount Δu = m(b0 + b1), m is a positive integer, m ≥ 1; The larger the value of m is, the lower the machining precision is, and the higher the production efficiency is; The smaller the value of m is, the higher the machining precision is, and the lower the production efficiency is; b0 is the rib spacing of the wallboard part, and b1 is the rib shoulder width of the wallboard part; Step five: repeat step four, according to the total number of grids M in the arc direction of the wallboard, the value of m in the progressive bending forming feed amount Δu = m(b0 + b1), and the value of n in the width s = (2n-1)(b0 + b1) of the inner side of the bending die, the number of bending forming M1 is determined, M1 = [M-2(n-1)] / m, M1, M, m and n are all positive integers; after M1 times of bending forming, the magnesium alloy whole wallboard part is taken out, and the magnesium alloy whole wallboard part with large size and equal curvature shape is machined.

9. A method of rigid diaphragm press bending of a magnesium alloy monocoque panel according to claim 8, wherein: The preheating temperature T1 of the bending die is 150-180℃.

10. A method of rigid diaphragm press bending of a magnesium alloy monocoque panel according to claim 8, wherein: The forming temperature T is 260-280℃.

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