Heating mold and application of hot forming process of heating mold

Abstract

The invention discloses a heating mold and application of a hot forming process thereof.The mold comprises a workbench, a water cooling plate, a lower mold assembly and an upper mold assembly, the workbench is arranged on a machining equipment platform, the lower mold assembly is arranged on the machining equipment platform, and the upper mold assembly is arranged on the lower mold assembly; the water cooling plate is arranged on the upper die assembly, and the top of the water cooling plate is connected with a machining equipment sliding block. The die is suitable for common press equipment, complex transformation and addition of a water cooling system are not needed, the common press equipment and the hot forming die are isolated, and the equipment is prevented from being damaged by high temperature. The mold adopts the mica plate for heat preservation and heat insulation, rapid loss of temperature is avoided, the temperature stability of the mold can be guaranteed, and then the machining effect is guaranteed. Temperature field finite element analysis can be carried out according to ANSYS, repeated iteration adjustment is carried out, the temperature of a temperature control area is determined, and it is guaranteed that the temperature of all molded surfaces meets the process requirement.

Description

Technical Field

[0001] The invention belongs to the technical field of sheet metal forming, and in particular relates to an application of a heating mold and a hot forming process thereof. Background Art

[0002] Titanium alloy materials have high strength at room temperature, poor plasticity, and large springback, making them difficult to use in sheet metal forming. At the same time, the forming performance of titanium alloys is extremely sensitive to temperature, so isothermal hot forming processes are generally used to form molds and parts in a relatively stable temperature environment to ensure precise control of the forming temperature. The isothermal hot forming process of titanium alloys requires special hot forming production equipment, the part production cycle is extremely long, the production cost is extremely high, and the production equipment is limited. Therefore, a heating mold and a corresponding forming process are needed to reduce production costs, improve the versatility of molds with existing equipment, and improve the production qualification rate of products.

[0003] The patent document with announcement number CN115945590A discloses a hot forming mold for aviation titanium alloy sheet metal parts. Electric heating plates are fixedly connected on both sides of the outer wall of the upper mold, but the mold is heated on one side. At the same time, the overall structure of the electric heating plate is difficult to control the temperature in different areas. The entire electric heating plate has a single heating temperature, which has the disadvantage of high energy consumption. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an application of a heating mold and a thermoforming process thereof.

[0005] The present invention is achieved through the following technical solutions.

[0006] A heating mold provided by the present invention comprises a workbench, a water-cooling plate, a lower mold assembly and an upper mold assembly, wherein the workbench is arranged on a processing equipment platform, the lower mold assembly is arranged on the processing equipment platform, the upper mold assembly is arranged on the lower mold assembly, the water-cooling plate is arranged on the upper mold assembly, and the top of the water-cooling plate is connected to a slider of the processing equipment.

[0007] Preferably, the lower die assembly comprises a lower die plate, a lower die pad, a lower die and a edge pressing assembly, the lower die plate is arranged on a workbench, the lower die pad is arranged on the lower die plate, and the lower die and the edge pressing assembly are arranged on the lower die pad.

[0008] Preferably, the edge holding assembly comprises an edge holding pad and an edge holding, the lower die passes through the edge holding pad and the edge holding, the edge holding pad is arranged on the lower die pad, and the edge holding is arranged on the edge holding pad.

[0009] Preferably, heat insulation plates are arranged on both sides of the edge pressing, a first processing groove is arranged on the top of the edge pressing, a first processing tooth is arranged in the processing groove, the edge pressing comprises an edge pressing body and a first processing part, one end of the edge pressing body is connected to the first processing part, and the other end of the edge pressing body is connected to the edge pressing pad.

[0010] Preferably, heating tubes are respectively provided on the edge pressing body and the first processing part.

[0011] Preferably, the upper mold assembly includes an upper mold and an upper mold plate, a heat insulation plate is arranged between the upper mold and the upper mold plate, and the upper mold is connected to the lower mold assembly.

[0012] Preferably, a second processing groove is provided on the upper mold, a second processing tooth is provided in the second processing groove, the upper mold plate is connected to the water-cooling plate through a heat insulation plate, the upper mold includes an upper mold body and a second processing part, one end of the upper mold body is connected to the second processing part, and the other end of the upper mold body is connected to the heat insulation plate.

[0013] Preferably, heating tubes are provided on the upper mold body and the second processing part.

[0014] An application of a heated mold thermoforming process comprises the following steps:

[0015] 1) The edge holding pad is lifted up by the top rod of the processing equipment, and the edge holding pad drives the edge holding pad to move upward, so that the bottom surface height of the edge holding pad and the edge holding pad is greater than the bottom surface height of the lower die;

[0016] 2) Preheating the mold;

[0017] 3) placing the preformed part on the edge holding portion through the positioning of the first processing groove;

[0018] 4) Preheat the parts;

[0019] 5) The processing equipment slider drives the upper mold assembly downward to close the mold with the edge clamp;

[0020] 6) The upper die and the edge clamp are pressed down to the limit position;

[0021] 7) Open the mold;

[0022] 8) The parts are stepped on the mold in sequence, and steps 2) to 7) are repeated until the hot forming process of the parts is completed.

[0023] Preferably, in step 2), the mold is preheated to 680-720°C; in step 4), the part is preheated for 5-15 minutes; in step 5), the blank holding force is 10-30 tons; in step 6), the processing equipment has a downward speed of 5 mm / s and a mold clamping tonnage of 80-120 tons.

[0024] The beneficial effects of the present invention are:

[0025] (1) The mold of the present invention is suitable for ordinary press equipment, and there is no need to carry out complex modifications. A water cooling system is added to isolate the ordinary press equipment and the hot forming mold to avoid high temperature damage to the equipment.

[0026] (2) The mold of the present invention uses mica board for heat insulation to avoid rapid temperature loss, thereby ensuring the stability of the mold temperature and further ensuring the processing effect.

[0027] (3) The present invention can perform finite element analysis of the temperature field based on ANSYS, perform repeated iterative adjustments, and determine the temperature of the temperature control zone to ensure that the temperature of all molding surfaces meets the process requirements. The heating tubes are evenly distributed to ensure uniform heating of the mold and the heating effect on the parts.

[0028] (4) The present invention can perform finite element analysis of the force and temperature coupling field through ANSYS, predict mold deformation and perform pre-compensation; ensure mold gap through repeated iterative compensation of the mold; and realize multi-point zone temperature control through the SCR (semiconductor controlled rectifier) ​​temperature control system. The temperature control table is matched with SCR linear heating. When starting at room temperature, it heats according to the set heating rate. When approaching the target temperature, the output power of the heating tube will be reduced. When the temperature is constant, the power required for compensation is calculated according to the heat loss rate to maintain the proportional output of the heating tube. Compared with the on-off temperature control of SSR (solid-state relay), it is more accurate, has better energy-saving effect, and is conducive to extending the life of the heating tube. The control accuracy of SCR is ±3℃. For example, if it is set to 700℃, the temperature will fluctuate within the range of 697~703℃, and the temperature control can be precise. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the structure of the present invention;

[0030] Figure 2 It is a side structural schematic diagram of the present invention;

[0031] Figure 3 is a schematic structural diagram of Embodiment 1 of the present invention;

[0032] Figure 4 is a schematic structural diagram of Embodiment 2 of the present invention;

[0033] Figure 5 is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0034] Figure 6 It is a schematic structural diagram of Comparative Example 1 of the present invention;

[0035] Figure 7 It is a schematic diagram of the structure of the parts prepared by the present invention;

[0036] Figure 8It is a schematic diagram of the forming process of the part of the present invention;

[0037] In the figure: 1-workbench, 2-water cooling plate, 3-lower template, 4-lower mold pad, 5-lower mold, 61-edge holding pad, 62-edge holding, 621-edge holding body, 622-first processing part, 63-processing groove, 7-insulation board, 81-upper mold, 811-upper mold body, 812-second processing part, 82-upper template, 83-second processing groove, 9-heating tube, 101-processing equipment platform, 102-processing equipment slider, 103-processing equipment ejector, 201-parts, A-first temperature control zone, B-second temperature control zone, C-third temperature control zone, D-fourth temperature control zone, E-fifth temperature control zone, F-sixth temperature control zone, G-seventh temperature control zone, H-eighth temperature control zone. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0039] Embodiment 1:

[0040] like Figure 1 , 2 As shown in Figures 3, 7 and 8, a heating mold comprises a workbench 1, a water-cooling plate 2, a lower mold assembly and an upper mold assembly. The workbench 1 is arranged on a processing equipment platform 101, the lower mold assembly is arranged on the processing equipment platform 101, the upper mold assembly is arranged on the lower mold assembly, the water-cooling plate 2 is arranged on the upper mold assembly, and the top of the water-cooling plate 2 is connected to a processing equipment slider 102. The processing equipment is a hydraulic pad double-acting hydraulic press, and the processing equipment push rod 103 passes through the processing equipment platform 101, the workbench 1, the lower mold plate 3, the lower mold pad 4 from bottom to top in sequence and then is connected to the edge pressure pad 61. A water inlet and a water outlet are arranged on the water-cooling plate 2, and water can be filled inside the water-cooling plate 2 for cooling, and the water inside the water-cooling plate 2 is connected to a water pump through the water inlet and the water outlet, respectively. The arrangement of the water-cooling plate 2 can reduce the heat conducted to the processing equipment and avoid overheating and damage to the processing equipment.

[0041] The lower die assembly includes a lower die plate 3, a lower die pad 4, a lower die 5 and a pressure edge assembly. The lower die plate 3 is arranged on the workbench 1, the lower die pad 4 is arranged on the lower die plate 3, and the lower die 5 and the pressure edge assembly are arranged on the lower die pad 4.

[0042] The edge clamping assembly includes an edge clamping pad 61 and an edge clamping 62. The lower mold 5 passes through the edge clamping pad 61 and the edge clamping 62. The edge clamping pad 61 is arranged on the lower mold pad 4, and the edge clamping 62 is arranged on the edge clamping pad 61. The top of the edge clamping 62 is in contact and connected with the upper mold assembly.

[0043] Insulation plates 7 are arranged on both sides of the edge clamp 62, a first processing groove 63 is arranged on the top of the edge clamp 62, a first processing tooth is arranged in the processing groove 63, the edge clamp 62 includes an edge clamp body 621 and a first processing part 622, one end of the edge clamp body 621 is connected to the first processing part 622, and the other end of the edge clamp body 621 is connected to the edge clamp pad 61.

[0044] The first processing parts 622 are respectively provided with heating tubes 9 , and the heating tubes 9 are vertically arranged to the pressing edge 62 .

[0045] The upper mold assembly includes an upper mold 81 and an upper mold plate 82, between which a heat insulation board 7 is arranged, and the upper mold 81 is in contact with the pressing edge 62 of the lower mold assembly. The heat insulation board 7 is a mica board to prevent the rapid loss of mold temperature.

[0046] A second processing groove 83 is provided on the upper mold 81, and a second processing tooth is provided in the second processing groove 83. The second processing tooth is meshed with the first processing tooth. The upper mold plate 82 is connected to the water-cooled plate 2 through the insulation plate 7. The upper mold 81 includes an upper mold body 811 and a second processing part 812. One end of the upper mold body 811 is connected to the second processing part 812, and the other end of the upper mold body 811 is connected to the insulation plate 7.

[0047] A heating tube 9 is disposed on the second processing portion 812 , and the heating tube 9 is vertically disposed to the upper mold 81 .

[0048] The first processing part 622 and the second processing part 812 are arranged in an arc shape to adapt to the shape of the part 201. A number of heating tubes 9 are evenly arranged on the edge clamp 62 and the upper mold 81, and the mold and the part 201 are heated by the heating tubes 9. The SCR (semiconductor controlled rectifier) ​​temperature control system can realize multi-point zone temperature control, and determine the number and position of the heating tubes 9. The temperature field finite element analysis is performed according to ANSYS and after fine-tuning of the trial mold, the zone temperature control temperature is determined. The force and temperature coupling field finite element analysis is performed by ANSYS to predict the mold deformation and pre-compensate. The mold gap is ensured by the mold iterative compensation method.

[0049] An application of a heated mold thermoforming process comprises the following steps:

[0050] 1) The edge holding pad 61 is lifted up by the processing equipment push rod 103, and the edge holding pad 61 drives the edge holding 62 to move upward, so that the bottom surface heights of the edge holding pad 61 and the edge holding 62 are both greater than the bottom surface height of the lower mold 5;

[0051] 2) Preheat the mold to 680°C;

[0052] 3) placing the preformed part 201 on the edge holding part 62 through the positioning of the first processing groove 63;

[0053] 4) Preheat part 201 for 5 minutes;

[0054] 5) The processing equipment slider 102 drives the upper mold assembly downward to close the mold with the edge clamp 62, and the edge clamp force is 10t;

[0055] 6) The upper mold 81 and the edge clamp 62 are clamped and pressed downward to the limit position, the downward speed of the processing equipment is 5mm / s, and the clamping tonnage is 80t;

[0056] 7) Open the mold;

[0057] 8) The part 201 is sequentially stepped on the mold, and the actions of steps 2) to 7) are repeated until the hot forming process of the part 201 is completed.

[0058] The heating tube 9 of the first processing part 622 and the second processing part 812 is the first temperature control zone A. The heating tubes 9 in the temperature control zone are uniformly temperature controlled, and the temperature of the heating tubes 9 is set to 700°C. The temperature control results show that because the area of ​​the first temperature control zone A is too small relative to the mold, heat is transferred inside the mold, and the temperature of the mold surface increases slowly; and the heat is unevenly transferred inside the mold, resulting in a large temperature difference on the surface.

[0059] Example 2

[0060] like Figure 4 As shown, the application of a heating mold and its thermoforming process is basically the same as that of Example 1, except that heating tubes 9 are respectively provided on the edge pressing body 621 and the first processing part 622, and the heating tubes 9 are vertically arranged to the edge pressing 62.

[0061] A heating tube 9 is disposed on the upper mold body 811 and the second processing portion 812 , and the heating tube 9 is disposed vertically to the upper mold 81 .

[0062] The heating tubes 9 of the first processing part 622 and the second processing part 812 are in the second temperature control zone B, the heating tubes 9 of the edge pressing body 621 are in the third temperature control zone C, and the upper mold body 811 is in the fourth temperature control zone D; the heating tubes 9 in each temperature control zone are uniformly controlled. The second temperature control zone B, the third temperature control zone C and the fourth temperature control zone D are all set to 700℃; the temperature control results show that the mold surface can quickly reach the forming temperature of 700℃; under the joint action of the third temperature control zone C and the fourth temperature control zone D, the top mold surface of the upper mold 81 can be stabilized at the forming temperature of 700 degrees Celsius, and the mold surface temperature at both ends of the upper mold 81 cannot reach the forming temperature of 700℃.; Under the joint action of the second temperature control zone B and the fourth temperature control zone D, the mold surface temperature of the lower mold 5 and the edge pressing 62 greatly exceeds the forming temperature of 700℃, and the mold surface temperature of the lower mold 5 and the edge pressing 62 at both ends cannot reach the forming temperature of 700℃.

[0063] In an application of a heated mold thermoforming process, in step 2), the mold is preheated to 720°C; in step 4), the part is preheated for 15 minutes; in step 5), the blank holding force is 30 tons; in step 6), the processing equipment has a downward speed of 5 mm / s and a mold clamping tonnage of 120 tons.

[0064] Example 3

[0065] like Figure 5 As shown, the application of a heating mold and its thermoforming process is basically the same as that of Example 1, except that heating tubes 9 are respectively provided on the edge pressing body 621 and the first processing part 622, and the heating tubes 9 are vertically arranged to the edge pressing 62.

[0066] A heating tube 9 is disposed on the upper mold body 811 and the second processing portion 812 , and the heating tube 9 is disposed vertically to the upper mold 81 .

[0067] The heating tubes 9 in the middle of the first processing part 622 and the second processing part 812 are the fifth temperature control zone E, the heating tubes 9 on both sides of the first processing part 622 and the second processing part 812 are the sixth temperature control zone F, the heating tubes 9 of the edge pressing body 621 are the seventh temperature control zone G, and the upper mold body 811 is the eighth temperature control zone H; the heating tubes 9 in each temperature control zone are uniformly controlled. The fifth temperature control zone E is set at 700°C, the sixth temperature control zone F is set at 735°C, the seventh temperature control zone G is set at 585°C, and the eighth temperature control zone H is set at 700°C; the temperature control results show that the mold surface can quickly reach the forming temperature of 700°C; and the relative temperature is uniform, ensuring that the temperature of all mold surfaces is 700°C.

[0068] In an application of a heated mold hot forming process, in step 2), the mold is preheated to 700°C; in step 4), the part is preheated for 8 minutes; in step 5), the blank holding force is 20 tons; in step 6), the processing equipment has a downward speed of 5 mm / s and a mold clamping tonnage of 100 tons.

[0069] Comparative Example 1

[0070] like Figure 6 As shown, the application of a heating mold and its thermoforming process is basically the same as that of Example 1, except that the heating tube 9 is not provided.

[0071] The specifications of the processed parts 201 in Examples 1-3 and Comparative Example 1 are: material TA15, material thickness 0.5 mm, bending diameter Φ376 mm, bending angle of about 130°, and the hot forming process in Examples 1-3 forms a plurality of parallel serrated groove structures on the sheet metal of the parts 201. The molds and methods of Examples 1-3 and Comparative Example 1 are used to perform hot forming process on 200 parts 201, and the results are shown in the following table.

[0072]

[0073] It can be seen from the above table that adding a heating tube 9 can improve the part processing qualification rate. Adding heating tubes 9 to both the edge holding body 621 and the upper mold body 811, and dividing the heating tubes 9 of the first processing part 622 and the second processing part 812 into two temperature control zones can better improve the finished product qualification rate.

Claims

1. A heating mold, characterized in that: The invention comprises a workbench (1), a water-cooling plate (2), a lower mold assembly and an upper mold assembly, wherein the workbench (1) is arranged on a processing equipment platform (101), the lower mold assembly is arranged on the processing equipment platform (101), the upper mold assembly is arranged on the lower mold assembly, the water-cooling plate (2) is arranged on the upper mold assembly, and the top of the water-cooling plate (2) is connected to a processing equipment slider (102).

2. A heating mold according to claim 1, characterized in that: The lower die assembly comprises a lower die plate (3), a lower die pad (4), a lower die (5) and a pressure edge assembly; the lower die plate (3) is arranged on a workbench (1); the lower die pad (4) is arranged on the lower die plate (3); and the lower die (5) and the pressure edge assembly are arranged on the lower die pad (4).

3. A heating mold according to claim 2, characterized in that: The edge holding assembly comprises an edge holding pad (61) and an edge holding pad (62); the lower die (5) passes through the edge holding pad (61) and the edge holding pad (62); the edge holding pad (61) is arranged on the lower die pad (4); and the edge holding pad (62) is arranged on the edge holding pad (61).

4. A heating mold according to claim 3, characterized in that: Heat insulation plates (7) are arranged on both sides of the edge pressing (62), a first processing groove (63) is arranged on the top of the edge pressing (62), a first processing tooth is arranged in the processing groove (63), the edge pressing (62) comprises an edge pressing body (621) and a first processing part (622), one end of the edge pressing body (621) is connected to the first processing part (622), and the other end of the edge pressing body (621) is connected to the edge pressing pad (61).

5. A heating mold according to claim 4, characterized in that: Heating tubes (9) are respectively arranged on the edge pressing body (621) and the first processing portion (622).

6. A heating mold according to claim 1, characterized in that: The upper mold assembly comprises an upper mold (81) and an upper mold plate (82), a heat insulation plate (7) is arranged between the upper mold (81) and the upper mold plate (82), and the upper mold (81) is connected to the lower mold assembly.

7. A heating mold according to claim 6, characterized in that: A second processing groove (83) is arranged on the upper mold (81), and a second processing tooth is arranged in the second processing groove (83). The upper mold plate (82) is connected to the water-cooled plate (2) via a heat insulation plate (7). The upper mold (81) comprises an upper mold body (811) and a second processing portion (812), one end of the upper mold body (811) is connected to the second processing portion (812), and the other end of the upper mold body (811) is connected to the heat insulation plate (7).

8. A heating mold according to claim 7, characterized in that: A heating tube (9) is provided on the upper mold body (811) and the second processing portion (812).

9. An application of the heated die thermoforming process according to any one of claims 1 to 8, characterized in that: The following steps are involved: 1) The edge holding pad (61) is lifted up by a processing equipment push rod (103), and the edge holding pad (61) drives the edge holding (62) to move upward, so that the bottom surface heights of the edge holding pad (61) and the edge holding (62) are both greater than the bottom surface height of the lower mold (5); 2) Preheating the mold; 3) placing the preformed part (201) on the edge pressing (62) through the positioning of the first processing groove (63); 4) preheating the part (201); 5) The processing equipment slide block (102) drives the upper mold assembly downward to close the mold with the edge clamp (62); 6) The upper die (81) and the edge holder (62) are clamped together and pressed downward until they reach the limit position; 7) Open the mold; 8) The part (201) is sequentially stepped on the mold, and the actions of steps 2) to 7) are repeated until the thermoforming process of the part (201) is completed.

10. Application of a heated mold thermoforming process as claimed in claim 9, characterized in that: In the step 2), the mold is preheated to 680-720° C.; in the step 4), the part (201) is preheated for 5-15 minutes; in the step 5), the blank holding force is 10-30 tons; in the step 6), the downward speed of the processing equipment is not greater than 5 mm / s, and the mold clamping tonnage is 80-120 tons.

Images