Thermal forming process

Abstract

The invention discloses a thermal forming process which comprises the following steps: S1, counting part design data and final modeling data of produced parts with the same part modeling and same manufacturing process parameters; setting shrinkage amount and manufacturing tolerance dimension; s2, the initial tolerance size of the part to be machined is modified, and the final tolerance size is obtained; s3, modifying the initial part data of the to-be-processed part to obtain final part data; s4, designing a tolerance zone; s5, the blank is punched and blanked based on the tolerance zone, and a to-be-machined part is obtained; and S6, the to-be-machined part is fed into the thermal forming die through a feeding device to be subjected to stamping machining, and a stamping part is obtained. According to the invention, the tolerance of the to-be-processed part after stamping and blanking can be ensured to be within the tolerance zone range, the flowing stability of the to-be-processed part in the thermal forming process is ensured, and the tolerance of a stamping part obtained after thermal forming cannot exceed the tolerance zone range, so that the stamping part does not need to be subjected to side line cutting, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoforming, and more particularly to a thermoforming process. Background Art

[0002] At present, general hot-formed parts in the automotive industry need to be cold-stamped and trimmed after hot stamping, and then the excess waste is cut off. However, the strength of hot-stamped parts after quenching is as high as 1350Mpa-1500Mpa. If cold-stamping is used for trimming, the trimming edge of the mold will be severely worn. After a shift of stamping, maintenance is required, and a large number of spare parts are required. The edge of the trimming blade is weak and chipping often occurs. High-strength sheet metal has high requirements for the punching force of the press. Complex parts require multiple processes to complete the trimming of the parts, which is costly and the burrs of the product are also large. If laser cutting is used, the cost is high.

[0003] Therefore, a thermoforming process is required to eliminate the trimming of parts after thermoforming, thereby reducing the production cost of parts. Summary of the invention

[0004] Another object of the present invention is to provide a hot forming process which does not require edge cutting of stamping parts, thereby reducing production costs.

[0005] In order to achieve these objects and other advantages according to the present invention, a thermoforming process is provided, comprising the following steps: S1. Count the part design data and final modeling data of the parts that have been produced with the same part modeling and manufacturing process parameters; analyze the part design data and final modeling data, and set the shrinkage amount and manufacturing tolerance size; S2. Obtaining the initial tolerance size of the part to be processed, and modifying the initial tolerance size based on the manufacturing tolerance size to obtain the final tolerance size; S3, obtaining initial part data of the part to be processed, and modifying the initial part data based on the designed shrinkage and final tolerance size to obtain final part data; S4. Design the tolerance zone based on the final tolerance size, final part data and set shrinkage; S5, punching and blanking the blank based on the tolerance zone to obtain a part to be processed, wherein both ends of the part to be processed are punched with positioning holes during the punching and blanking process; S6. Feed the parts to be processed into the hot forming mold through the feeding device for stamping to obtain stamped parts.

[0006] Preferably, the thermoforming mold comprises: An upper base and a lower base are arranged opposite to each other, the upper base and the lower base are connected as a whole through a guide column, an upper template is slidably connected to the guide column, the upper template is located between the upper base and the lower base, an upper shearing die is installed on the bottom surface of the upper template, and a stretching head is accommodated in the inner cavity of the upper shearing die; A hydraulic cylinder, whose fixed end is fixed to the top surface of the upper base, and whose free end vertically passes through the bottom surface of the upper base and is connected to the fixed end of the cylinder. The fixed end of the cylinder is fixedly arranged on the top surface of the upper template, and the free end of the cylinder passes through the bottom surface of the upper template and is connected to the stretching head; A lower shearing die is arranged on the top surface of the lower base, and a forming die is arranged inside the lower shearing die; In S6, during stamping processing, the feeding device feeds the parts to be processed to the top surface of the lower shear die, drives the free end of the hydraulic cylinder to extend, and the upper mold plate slides downward under the drive of the hydraulic cylinder to the upper and lower shear dies to close the mold, pressing the parts to be processed against the top surface of the upper shear die, and drives the free end of the cylinder to extend to drive the stretching head to move downward, and cooperates with the forming die to perform stamping processing on the parts to be processed.

[0007] Preferably, a limiting member is provided on the thermoforming die, and the part to be processed is located in the stamping area of ​​the thermoforming die after being fixed on the limiting member through the positioning hole.

[0008] Preferably, the limiting member comprises a plurality of first limiting members arranged on the top surface of the lower shearing die, and a plurality of second limiting members arranged on the bottom surface of the upper shearing die, and the plurality of first limiting members, the plurality of second limiting members and the plurality of positioning holes on the sheet are arranged in one-to-one correspondence; The first limiting member comprises: An arc-shaped groove is provided on the top surface of the lower shearing die, a limiting column is arranged in the arc-shaped groove, a spring is fixedly connected between the limiting column and the inner bottom surface of the arc-shaped groove, a positioning column is installed on the top of the limiting column, the diameter of the limiting column is larger than the diameter of the positioning hole, the diameter of the positioning column is smaller than the diameter of the positioning hole, and the top surface of the limiting column extends out of the top surface of the lower shearing die; The second limiting member is a limiting groove provided on the bottom surface of the upper shearing die; During stamping processing, the parts to be processed are limited in the stamping area of ​​the hot forming mold by the positioning columns. The upper shearing die is driven by the hydraulic cylinder to move downward until the limiting groove thereon is plugged into the positioning column and pressure is applied to the limiting column. The limiting column compresses the spring downward until the top surface of the limiting column and the top surface of the upper shearing die are on the same horizontal plane, and the upper shearing die and the lower shearing die are closed.

[0009] Preferably, the inner side wall of the arc-shaped groove does not contact the limiting column, and the lower shearing die is provided with a first air vent hole, which connects the arc-shaped groove and the outside of the lower shearing die; the upper shearing die is provided with a second air vent hole, which connects the limiting groove and the inner cavity of the upper shearing die, and the diameter of the limiting groove is larger than the diameter of the positioning column and the limiting column; the limiting column is provided with an air duct connected with the arc-shaped groove and the limiting groove.

[0010] Preferably, a plurality of limiting plates are arranged at intervals on the outer periphery of the limiting column, one end of any limiting plate is hinged to the outer side wall of the top surface of the limiting column, and the other end is abutted against the inner side wall of the arc-shaped groove; During stamping, the limit column compresses the spring downward, driving the limit plate to slide along the inner wall of the arc groove to a horizontal state, and the top surface of the limit plate and the top surface of the upper shear die are located in the same horizontal plane.

[0011] The present invention includes at least the following beneficial effects: before the hot forming process, the present invention analyzes, modifies and determines the relevant data of the parts to be processed and then designs the tolerance band. Since the stamping and blanking process is controllable, stamping and blanking are performed based on the tolerance band to ensure that the tolerance of the parts to be processed after stamping and blanking is within the tolerance band. The tolerance is controllable, and positioning holes are punched on the parts to be processed during stamping and blanking. The positioning holes are used to give the parts to be processed a shrinkage allowance during hot forming, so that the parts to be processed can shrink or expand within the range of the positioning holes. At the same time, the tolerance band will also allow the parts to be processed to have sufficient shrinkage allowance during the hot forming process, ensuring the stability of the flow of the parts to be processed during the hot forming process, and ultimately making the tolerance of the stamped parts obtained after the hot forming process not exceed the tolerance band, so that there is no need to cut the edges of the stamped parts, thereby reducing production costs.

[0012] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front view structural schematic diagram of a thermoforming mold in which an upper shearing mold and a lower shearing mold are separated from each other according to one embodiment of the present invention; Figure 2 It is a front view structural schematic diagram of the upper shearing die and the lower shearing die in the above embodiment in the mold closing state; Figure 3 for Figure 2 A is a schematic diagram of the enlarged structure of the middle part; Description of the Figures in the Specification: 1. Upper base, 2. Lower base, 3. Guide column, 4. Upper template, 5. Upper shearing die, 6. Stretching head, 7. Hydraulic cylinder, 8. Cylinder, 9. Lower shearing die, 10. Forming die, 11. Arc groove, 12. Limit column, 13. Spring, 14. Positioning column, 15. Limit groove, 16. Limit plate, 17. First vent hole, 18. Second vent hole, 19. Inner cavity of upper shearing die. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0015] It should be noted that, in the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0016] like Figure 1-3 As shown, the present invention provides a thermoforming process, comprising the following steps: S1. Count the part design data and final modeling data of the parts that have been produced with the same part modeling and manufacturing process parameters; analyze the part design data and final modeling data, and set the shrinkage amount and manufacturing tolerance size; S2. Obtaining the initial tolerance size of the part to be processed, and modifying the initial tolerance size based on the manufacturing tolerance size to obtain the final tolerance size; S3, obtaining initial part data of the part to be processed, and modifying the initial part data based on the designed shrinkage and final tolerance size to obtain final part data; S4. Design the tolerance zone based on the final tolerance size, final part data and set shrinkage; S5, punching and blanking the blank based on the tolerance zone to obtain a part to be processed, wherein both ends of the part to be processed are punched with positioning holes during the punching and blanking process; S6. Feed the parts to be processed into the hot forming mold through the feeding device for stamping to obtain stamped parts.

[0017] In the above technical scheme, a hot forming process provided by the present application is suitable for bidirectional stamping and stretching of parts to be processed. First, based on the parts that have been produced, the part design data and the final modeling data are obtained, and the data are analyzed to set the shrinkage amount of the parts to be processed due to hot forming shrinkage during the hot forming process and the manufacturing tolerance size generated during the process manufacturing process. Based on the manufacturing tolerance size, the initial tolerance size of the parts to be processed is modified to make the tolerance size of the parts to be processed adapt to the current manufacturing process. Then, according to the modified final tolerance size and shrinkage, the initial part data of the parts to be processed is modified to obtain the final part data. The final part data is the preset part after the parts to be processed are completed. Data, based on the preset final part data and the final tolerance size and shrinkage, the tolerance zone is designed. Since the stamping and blanking process is controllable, stamping and blanking based on the tolerance zone can ensure that the tolerance of the parts to be processed after stamping and blanking is within the tolerance zone. The tolerance is controllable, and the locating holes are used to give the parts to be processed a shrinkage allowance during hot forming, so that the parts to be processed can shrink or expand within the range of the locating holes. At the same time, the tolerance zone will also allow the parts to be processed to have sufficient shrinkage allowance during the hot forming process, ensuring the stability of the flow of the parts to be processed during the hot forming process. Ultimately, the tolerance of the stamped parts obtained after hot forming will not exceed the tolerance zone, so there is no need to cut the edges of the stamped parts, reducing production costs.

[0018] In another technical solution, Figure 1 , Figure 2 As shown, the thermoforming mold comprises: An upper base 1 and a lower base 2 are arranged opposite to each other, the upper base 1 and the lower base 2 are connected as a whole through a guide column 3, an upper template 4 is slidably connected to the guide column 3, the upper template 4 is located between the upper base 1 and the lower base 2, an upper shearing die 5 is installed on the bottom surface of the upper template 4, and a stretching head 6 is accommodated in the inner cavity 19 of the upper shearing die; A hydraulic cylinder 7, whose fixed end is fixed to the top surface of the upper base 1, and whose free end vertically passes through the bottom surface of the upper base 1 and is connected to the fixed end of a cylinder 8, whose fixed end is fixedly arranged on the top surface of the upper template 4, and whose free end passes through the bottom surface of the upper template 4 and is connected to the stretching head 6; A lower shearing die 9 is arranged on the top surface of the lower base 2, and a forming die 10 is arranged inside the lower shearing die 9; In S6, during stamping processing, the feeding device feeds the parts to be processed to the top surface of the lower shearing die 9, drives the free end of the hydraulic cylinder 7 to extend, and the upper mold plate 4 slides downward under the drive of the hydraulic cylinder 7 to the upper shearing die 5 and the lower shearing die 9 to close the mold, presses the parts to be processed against the top surface of the upper shearing die 5, drives the free end of the cylinder 8 to extend, drives the stretching head 6 to move downward, and cooperates with the forming die 10 to perform stamping processing on the parts to be processed.

[0019] In another technical solution, a limiting member is provided on the thermoforming die, and the part to be processed is located in the stamping area of ​​the thermoforming die after being fixed on the limiting member through the positioning hole.

[0020] In the present technical solution, the parts to be processed are limited in the stamping area by the limiting member during the hot forming process, which can ensure the stability of the shrinkage of the parts to be processed during the hot forming process, thereby further ensuring the stability of the flow of the parts to be processed.

[0021] In another technical solution, the stopper includes a plurality of first stoppers arranged on the top surface of the lower shearing die 9, and a plurality of second stoppers arranged on the bottom surface of the upper shearing die 5, and the plurality of first stoppers, the plurality of second stoppers and the plurality of positioning holes on the sheet are arranged in one-to-one correspondence; The first limiting member comprises: An arc groove 11 is provided on the top surface of the lower shearing die 9, a limiting column 12 is arranged in the arc groove 11, a spring 13 is fixedly connected between the limiting column 12 and the inner bottom surface of the arc groove 11, a positioning column 14 is installed on the top of the limiting column 12, the diameter of the limiting column 12 is larger than the diameter of the positioning hole, the diameter of the positioning column 14 is smaller than the diameter of the positioning hole, and the top surface of the limiting column 12 extends out of the top surface of the lower shearing die 9; The second limiting member is a limiting groove 15 provided on the bottom surface of the upper shearing die 5; During stamping processing, the parts to be processed are limited in the stamping area of ​​the hot forming mold by the positioning column 14. The upper shearing die 5 is driven by the hydraulic cylinder 7 to move downward to the limiting groove 15 thereon and connect with the positioning column 14 to apply pressure to the limiting column 12. The limiting column 12 compresses the spring 13 downward until the top surface of the limiting column 12 is on the same horizontal plane as the top surface of the upper shearing die 5, and the upper shearing die 5 and the lower shearing die 9 are closed.

[0022] In this technical solution, if Figure 3As shown, the arc groove 11 is used to accommodate the limiting column 12 and the spring 13, and the positioning column 14 is used to connect with the positioning hole on the part to be processed. In the initial state, the upper shearing die 5 and the lower shearing die 9 are separated from each other, and the top surface of the limiting column 12 extends out of the top surface of the lower shearing die 9. During the stamping process, the positioning hole on the part to be processed is firstly penetrated on the positioning column 14, and the part to be processed is limited to the stamping area by the positioning column 14. Then, the hydraulic cylinder 7 is driven to drive the upper shearing die 5 to move down to the limiting groove 15 and the positioning column 14. After that, the upper shearing die 5 continues to move downward to squeeze the spring 13 to drive the limiting column 12 to move down and be located at the same horizontal plane with the top surface of the upper shearing die 5. At this time, the upper The shearing die 5 and the lower shearing die 9 are closed, and then the stretching head 6 is driven downward to perform stamping on the parts to be processed. After the stamping is completed, the upper shearing die 5 is driven upward to separate from the lower shearing die 9, and the spring 13 is reset to push the limit column 12 out of the top surface of the lower shearing die 9, thereby ejecting the stamping part located on the positioning column 14 to prevent the stamping part from being stuck in the forming die 10, which is convenient for demoulding; the size of the positioning column 14 is smaller than the size of the positioning hole. While the positioning hole realizes the positioning function of the parts to be processed, it can also provide sufficient shrinkage margin for the parts to be processed, so that the parts to be processed can move within a small range, ensuring shrinkage stability and flow stability.

[0023] In another technical solution, the inner side wall of the arc groove 11 does not contact the limiting column 12, and a first air vent 17 is provided on the lower shearing die 9, which connects the arc groove 11 and the outside of the lower shearing die 9; a second air vent 18 is provided on the upper shearing die 5, which connects the limiting groove 15 and the inner cavity 19 of the upper shearing die, and the diameter of the limiting groove 15 is larger than the diameter of the positioning column 14 and the limiting column 12; and an air duct connected with the arc groove 11 and the limiting groove 15 is provided on the limiting column 12.

[0024] In the present technical solution, when the upper shearing die 5 and the lower shearing die 9 are closed, the air inside the forming die 10 is difficult to be discharged. When the stretching head 6 moves downward to punch the part to be processed, the surface of the stamped part after forming is easily affected by the compressed air, and quality problems such as pores are likely to appear. Therefore, if Figure 3As shown, the present application provides a second vent hole 18 on the upper shearing die 5, a first vent hole 17 on the lower shearing die 9, and an air passage connected to the arc groove 11 and the limiting groove 15 on the limiting column 12, wherein the air passage is connected to the arc groove 11 through the gap between the positioning column 14 and the positioning hole; when the upper shearing die 5 and the lower shearing die 9 are closed, the stretching head 6 moves downward, which will squeeze the air in the forming die 10, and the air will enter the upper shearing die cavity 19 from the gap between the forming die 10 and the stretching head 6, and then be discharged through the second vent hole 18, the gap between the limiting groove 15 and the positioning column 14, the gap between the positioning column 14 and the positioning hole, the air passage, the gap between the diameter of the arc groove 11 and the limiting column 12, and the first vent hole 17 in turn, thereby avoiding the appearance of pores on the surface of the stamping parts after forming, and ensuring the quality of the finished product.

[0025] In another technical solution, a plurality of limiting plates 16 are arranged at intervals on the outer periphery of the limiting column 12, one end of any limiting plate 16 is hinged to the outer side wall of the top surface of the limiting column 12, and the other end is abutted against the inner side wall of the arc groove 11; During stamping, the limit column 12 compresses the spring 13 downward, driving the limit plate 16 to slide along the inner wall of the arc groove 12 to a horizontal state, and the top surface of the limit plate 16 and the top surface of the upper shear die 5 are located in the same horizontal plane.

[0026] In the present technical solution, during the stamping process, the upper shear die 5 and the lower shear die 9 are closed at a very fast speed, and the limit column 12 is installed in the arc groove 11 through the spring 13, and the limit column 12 does not contact the inner wall of the arc groove 11. Under the impact of high speed and high pressure, the limit column 12 is prone to displacement during the compression of the spring 13. Therefore, the present application arranges a limit plate 16 at the outer peripheral interval of the limit column 12. The limit plate 16 is used to vertically guide and laterally limit the limit column 12, so that the limit column 12 vertically compresses the spring 13 during the stamping process.

[0027] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A thermoforming process, characterized in that: The following steps are involved: S1. Count the part design data and final modeling data of the parts that have been produced with the same part modeling and manufacturing process parameters; Analyze part design data and final modeling data, set shrinkage and manufacturing tolerance dimensions; S2. Obtaining the initial tolerance size of the part to be processed, and modifying the initial tolerance size based on the manufacturing tolerance size to obtain the final tolerance size; S3, obtaining initial part data of the part to be processed, and modifying the initial part data based on the designed shrinkage and final tolerance size to obtain final part data; S4. Design the tolerance zone based on the final tolerance size, final part data and set shrinkage; S5, punching and blanking the blank based on the tolerance zone to obtain a part to be processed, wherein both ends of the part to be processed are punched with positioning holes during the punching and blanking process; S6. Feed the parts to be processed into the hot forming mold through the feeding device for stamping to obtain stamped parts.

2. The thermoforming process according to claim 1, characterized in that The thermoforming mold comprises: An upper base and a lower base are arranged opposite to each other, the upper base and the lower base are connected as a whole through a guide column, an upper template is slidably connected to the guide column, the upper template is located between the upper base and the lower base, an upper shearing die is installed on the bottom surface of the upper template, and a stretching head is accommodated in the inner cavity of the upper shearing die; A hydraulic cylinder, whose fixed end is fixed to the top surface of the upper base, and whose free end vertically passes through the bottom surface of the upper base and is connected to the fixed end of the cylinder. The fixed end of the cylinder is fixedly arranged on the top surface of the upper template, and the free end of the cylinder passes through the bottom surface of the upper template and is connected to the stretching head; A lower shearing die is arranged on the top surface of the lower base, and a forming die is arranged inside the lower shearing die; In S6, during stamping processing, the feeding device feeds the parts to be processed to the top surface of the lower shear die, drives the free end of the hydraulic cylinder to extend, and the upper mold plate slides downward under the drive of the hydraulic cylinder to the upper and lower shear dies to close the mold, pressing the parts to be processed against the top surface of the upper shear die, and drives the free end of the cylinder to extend to drive the stretching head to move downward, and cooperates with the forming die to perform stamping processing on the parts to be processed.

3. The thermoforming process according to claim 2, characterized in that: A limiting piece is arranged on the thermoforming die, and the part to be processed is located in the stamping area of ​​the thermoforming die after being fixed on the limiting piece through the positioning hole.

4. The thermoforming process according to claim 3, characterized in that The limiting members include a plurality of first limiting members arranged on the top surface of the lower shearing die, and a plurality of second limiting members arranged on the bottom surface of the upper shearing die, and the plurality of first limiting members, the plurality of second limiting members and the plurality of positioning holes on the sheet are arranged in one-to-one correspondence; The first limiting member comprises: An arc-shaped groove is provided on the top surface of the lower shearing die, a limiting column is arranged in the arc-shaped groove, a spring is fixedly connected between the limiting column and the inner bottom surface of the arc-shaped groove, a positioning column is installed on the top of the limiting column, the diameter of the limiting column is larger than the diameter of the positioning hole, the diameter of the positioning column is smaller than the diameter of the positioning hole, and the top surface of the limiting column extends out of the top surface of the lower shearing die; The second limiting member is a limiting groove provided on the bottom surface of the upper shearing die; During stamping processing, the parts to be processed are limited in the stamping area of ​​the hot forming mold by the positioning columns. The upper shearing die is driven by the hydraulic cylinder to move downward until the limiting groove thereon is plugged into the positioning column and pressure is applied to the limiting column. The limiting column compresses the spring downward until the top surface of the limiting column and the top surface of the upper shearing die are on the same horizontal plane, and the upper shearing die and the lower shearing die are closed.

5. The thermoforming process according to claim 4, characterized in that The inner side wall of the arc-shaped groove does not contact the limiting column, and the lower shearing die is provided with a first air vent hole, which connects the arc-shaped groove and the outside of the lower shearing die; the upper shearing die is provided with a second air vent hole, which connects the limiting groove and the inner cavity of the upper shearing die, and the diameter of the limiting groove is larger than the diameter of the positioning column and the limiting column; the limiting column is provided with an air duct connected with the arc-shaped groove and the limiting groove.

6. The thermoforming process according to claim 4, characterized in that A plurality of limiting plates are arranged at intervals on the outer periphery of the limiting column, one end of each limiting plate is hinged to the outer side wall of the top surface of the limiting column, and the other end is abutted against the inner side wall of the arc groove; During stamping, the limit column compresses the spring downward, driving the limit plate to slide along the inner wall of the arc groove to a horizontal state, and the top surface of the limit plate and the top surface of the upper shear die are located in the same horizontal plane.

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