Springback compensation forming die for high-strength steel stamping part of automobile

Abstract

The utility model discloses a kind of automobile high-strength steel stamping part springback compensation forming die, it is related to automobile stamping die technical field, including lower die seat and upper die seat, the upper end of lower die seat is equipped with female die, the lower end of upper die seat is equipped with male die, the outer wall of female die four half-round angle place is equipped with limit seat, the inner wall of female die four half-round angle place is all through and is equipped with long hole with being opened.The utility model, springback compensation precision is significantly improved: the combination design of using "four groups of independent compensation mechanism+servo accurate drive+laser real-time detection", the automation closed-loop regulation and control of cooperation control module, the dynamic accurate adjustment of compensation amount is realized;The elastic buffer structure of buffer spring and buffer rod absorbs stamping impact and guarantees inlay block adjustment stability, effectively offsets the springback deformation of high-strength steel, solves the pain point of low compensation precision of traditional mould.

Description

Technical Field

[0001] This utility model relates to the field of automotive stamping die technology, and in particular to a springback compensation forming die for high-strength steel stamping parts for automobiles. Background Technology

[0002] As the automotive industry moves towards lightweight and high-strength materials, high-strength steel, with its excellent mechanical properties, is increasingly widely used in automotive body structural components, safety components, and other fields. However, during the stamping process, high-strength steel is prone to springback after stamping due to its high yield strength and relatively low elastic modulus. This leads to a decrease in the surface accuracy of the stamped parts, making them unable to meet assembly requirements.

[0003] However, in the existing technology, most high-strength steel stamping dies for automobiles adopt an integral structure design. When springback occurs, the entire die needs to be ground and corrected, which is not only costly to rectify, but also has a long debugging cycle. At the same time, the existing dies lack a targeted springback compensation mechanism. Adjusting process parameters based solely on experience is not enough to accurately offset the amount of springback, especially for stamping parts with complex shapes, where the springback control effect is poor. Utility Model Content

[0004] The purpose of this utility model is to solve the problems existing in the prior art by proposing a springback compensation forming mold for high-strength steel stamping parts for automobiles.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a springback compensation forming mold for high-strength steel stamping parts for automobiles, comprising a lower mold base and an upper mold base. A die cavity is installed at the upper end of the lower mold base, and a punch is installed at the lower end of the upper mold base. Limit seats are installed at four semi-circular angles on the outer wall of the die cavity. Elongated holes are opened through at four semi-circular angles on the inner wall of the die cavity. Inserts are slidably installed inside the four sets of elongated holes. Circular support frames are slidably installed inside the four sets of elongated holes. Fine-tuning cylinders are installed through at one end of each of the four sets of limit seats. Buffer springs are installed inside each of the four sets of circular support frames. Multiple buffer rods are slidably installed through at one end of each of the four sets of circular support frames. Circular plates are slidably installed inside each of the four sets of circular support frames.

[0006] Preferably, the extended ends of the four sets of fine-tuning cylinders are respectively fixed to the other ends of the four sets of circular support frames, and one end of the multiple sets of buffer rods is respectively fixed to one end of the four sets of inserts.

[0007] Preferably, the other end of the multiple sets of buffer rods is fixed to one end of the four sets of circular plates, and the other end of the four sets of buffer springs is in contact with the other end of the four sets of circular plates.

[0008] Preferably, the interior of the four sets of elongated holes is provided with two sets of guide grooves, and the interior of each of the eight sets of guide grooves is slidably installed with guide blocks. One end of each pair of guide blocks is fixed to the outer wall of a set of circular support frames.

[0009] Preferably, a pressure ring is slidably sleeved on the outer wall of the punch, and multiple sets of nitrogen springs are installed through the upper end of the upper die base, with the movable ends of the multiple sets of nitrogen springs fixed to the upper end of the pressure ring.

[0010] Preferably, the upper mold base is located above the lower mold base, a portion of the punch is disposed inside the die, a cooling mechanism is installed at one end of the lower mold base, a portion of the cooling mechanism is disposed inside the lower mold base, and guide posts are slidably installed through the upper end of the upper mold base, with the lower ends of the four sets of guide posts fixed to the upper end of the lower mold base.

[0011] Preferably, it also includes a control module, a displacement sensor is installed on the upper end of the pressure ring, the displacement sensor is connected to the control module, and all four sets of fine-tuning cylinders are connected to the control module.

[0012] Compared with the prior art, the advantages and positive effects of this utility model are as follows: 1. In this utility model, the springback compensation accuracy is significantly improved: the combination design of "four independent compensation mechanisms + servo precision drive + laser real-time detection" is adopted, and the automatic closed-loop control of the control module is used to realize the dynamic and precise adjustment of the compensation amount; the elastic buffer structure of the buffer spring and buffer rod absorbs the impact of stamping and ensures the stability of the insert adjustment, effectively offsetting the springback deformation of high-strength steel and solving the pain point of low compensation accuracy of traditional molds.

[0013] 2. In this utility model, the ease of operation and environmental adaptability are enhanced: the control module integrates a touch screen operation interface, supports parameter preset, data storage and fault alarm functions, and operators can get started after simple training; each key component adopts IP and above protection level design, which can adapt to the harsh working environment of stamping workshop such as dust, oil, and vibration, reduce equipment failure rate and ensure continuous and stable production. Attached Figure Description

[0014] Figure 1 A three-dimensional structural schematic diagram of a springback compensation forming mold for high-strength steel stamping parts for automobiles is provided for this utility model. Figure 2 This utility model provides a schematic diagram of the concave die structure for a springback compensation forming mold for high-strength steel stamping parts for automobiles. Figure 3 This utility model provides a structural diagram of the limiting seat, circular support frame, and insert of a springback compensation forming mold for high-strength steel stamping parts for automobiles. Figure 4This utility model provides a bottom view of the upper die base of a springback compensation forming mold for high-strength steel stamping parts for automobiles.

[0015] Legend: 1. Lower mold base; 2. Upper mold base; 3. Die; 4. Punch; 5. Cooling mechanism; 6. Guide post; 7. Limiting seat; 8. Elongated hole; 9. Insert; 10. Guide groove; 11. Guide block; 12. Round support frame; 13. Fine adjustment cylinder; 14. Buffer spring; 15. Buffer rod; 16. Round plate; 17. Pressure ring; 18. Nitrogen spring; 19. Displacement sensor. Detailed Implementation

[0016] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0017] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0018] Example 1: As Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, this utility model provides a springback compensation forming mold for high-strength steel stamping parts for automobiles, including a lower mold base 1 and an upper mold base 2. A die 3 is installed at the upper end of the lower mold base 1, and a punch 4 is installed at the lower end of the upper mold base 2. Limit seats 7 are installed at four semi-circular angles on the outer wall of the die 3. Elongated holes 8 are opened through at four semi-circular angles on the inner wall of the die 3. Inserts 9 are slidably installed inside the four sets of elongated holes 8. Circular support frames 12 are slidably installed inside the four sets of elongated holes 8. Fine-tuning cylinders 13 are installed through at one end of each of the four sets of limit seats 7. Buffer springs 14 are installed inside each of the four sets of circular support frames 12. Multiple sets of buffer rods 15 are dynamically installed. Circular plates 16 are slidably installed inside each of the four sets of circular support frames 12. The extended ends of the four sets of fine-tuning cylinders 13 are fixed to the other ends of the four sets of circular support frames 12. One end of each set of buffer rods 15 is fixed to one end of each of the four sets of inserts 9. The other end of each set of buffer rods 15 is fixed to one end of each of the four sets of circular plates 16. The other ends of the four sets of buffer springs 14 are in contact with the other ends of the four sets of circular plates 16. Two sets of guide grooves 10 are opened inside each of the four sets of elongated holes 8. Guide blocks 11 are slidably installed inside each of the eight sets of guide grooves 10. One end of each pair of guide blocks 11 is fixed to the outer wall of one set of circular support frames 12. The upper mold base 2 is located above the lower mold base 1. A part of the punch 4 is located inside the die 3. A cooling mechanism 5 is installed at one end of the lower mold base 1, and a part of the cooling mechanism 5 is located inside the lower mold base 1. Guide pillars 6 are slidably installed through the upper end of the upper mold base 2. The lower ends of the four sets of guide pillars 6 are fixed to the upper end of the lower mold base 1. The upper mold base 2 also includes a control module. A displacement sensor 19 is installed at the upper end of the pressure ring 17. The displacement sensor 19 is connected to the control module. The four sets of fine-tuning cylinders 13 are all connected to the control module.

[0019] The specific settings and functions of this embodiment are described below. The main body of the mold adopts a symmetrical frame structure, including a lower mold base 1 and an upper mold base 2. Both are made of high-strength gray cast iron HT300 material and are subjected to aging treatment to eliminate internal stress and ensure support stability. The top of the lower mold base 1 is reserved with a connection interface for the slider of the stamping equipment, and a T-slot structure is used to achieve quick clamping and fixing. The upper end of the lower mold base 1 is fixedly installed with a die 3 by high-strength internal hexagon bolts. The die 3 is made of Cr12MoV cold work die steel and is quenched and tempered at low temperature, with a working surface hardness of HRC58-62, which effectively improves wear resistance. The lower end of the upper mold base 2 corresponds to the position of the die 3 and is fixedly installed with a punch 4 by bolts of the same specification. The punch 4 is made of the same material Cr12MoV and its profile is precision ground. After assembly, part of the punch 4 extends into the interior of the die 3. The gap between the punch 4 and the die 3 is designed to be adapted to the thickness of the part to be stamped to ensure forming accuracy.

[0020] The springback compensation component is a core functional unit of the mold. It is designed for the springback-sensitive area of ​​the four semi-circular angles on the inner wall of the die 3. It has four independent compensation mechanisms. Each group includes a limit seat 7, an insert 9, a circular support 12, a fine-tuning cylinder 13, a buffer spring 14, a buffer rod 15, a circular plate 16, and a guide and positioning structure. The specific details are as follows: Limit seats and fine-tuning drive unit: Limit seats 7 are fixedly installed at the four semi-circular angles of the outer wall of the die 3 by welding. The limit seats 7 adopt a U-shaped cast steel structure with internal reinforcing ribs to withstand the lateral force of the fine-tuning cylinder 13 during operation. A fine-tuning cylinder 13 is installed through one end of each of the four limit seats 7. A servo fine-tuning cylinder is selected to achieve precise control of the compensation amount. A sealing flange is provided between the cylinder body of the fine-tuning cylinder 13 and the limit seat 7. The flange is equipped with a lip seal ring (material NBR) to adapt to the dusty and oily environment of the stamping workshop. Insert 9 and support transmission unit: Long holes 8 are opened through the four semi-circular angles of the inner wall of the die 3. Insert 9 is slidably installed inside the four sets of long holes 8. The material of insert 9 is hot work die steel H13. After quenching and tempering, the hardness reaches HRC48-52. Its forming surface is flush with the inner wall of the die 3. The reverse compensation surface is optimized and designed according to the preset springback amount (3°-8°) of the stamping part by Autoform simulation software. Circular support frame 12 is also slidably installed inside the four sets of long holes 8. It is a cylindrical shell structure with one open end. It is made of No. 45 steel and has been quenched and tempered. The inner wall is provided with guide steps. Elastic buffer unit: Each of the four sets of circular support frames 12 has a buffer spring 14 fixedly installed inside by a snap ring. Precision cylindrical helical springs with constant stiffness are selected to ensure stable buffering force. Each of the four sets of circular support frames 12 has eight sets of buffer rods 15 slidably installed through one end. The buffer rods 15 are evenly distributed in a ring along the axis of the circular support frame 12. Each of the four sets of circular support frames 12 has a circular plate 16 slidably installed inside the circular support frame 12. The circular plate 16 is made of 45 steel to ensure smooth sliding. Connection and guiding positioning: The extended ends of the four sets of fine-tuning cylinders 13 are fixedly connected to the other ends of the four sets of circular support frames 12 by threads. One end of the multiple sets of buffer rods 15 is fixed to one end of the four sets of inserts 9 by internal hex bolts, and the other end is fixed to one end of the four sets of circular plates 16 by welding. The other ends of the four sets of buffer springs 14 are respectively in contact with the other ends of the four sets of circular plates 16, forming a closed-loop structure of "cylinder drive - elastic buffer - insert 9 transmission". In order to prevent the circular support frame 12 from shifting laterally, two sets of symmetrical guide grooves 10 are opened inside the four sets of elongated holes 8. Guide blocks 11 are slidably installed inside the eight sets of guide grooves 10. One end of each pair of guide blocks 11 is fixed to the outer wall of a set of circular support frames 12 by welding.

[0021] A cooling mechanism 5 is installed at one end of the lower die base 1 via a bracket, which is adapted to the temperature control requirements of hot stamping scenarios. The cooling mechanism 5 includes a cooling water tank, a circulating water pump, cooling pipes and a temperature controller, which are embedded inside the die 3 and the lower die base 1 to ensure uniform cooling. The temperature controller is selected from the OMRONE5CC series and is connected to the PT100 temperature sensor in the cooling pipe.

[0022] The guide assembly ensures mold closing accuracy and includes four sets of guide pillars 6. The guide pillars 6 are made of SUJ2 bearing steel. Guide sleeves are slidably installed through the upper end of the upper mold base 2 at corresponding positions. Polyurethane elastomer buffer sleeves are fitted on the outer sides of the guide pillars 6 to effectively absorb the impact of mold closing. The lower ends of the four sets of guide pillars 6 are all fixedly connected to the upper end of the lower mold base 1 by threads, forming a four-point guide structure.

[0023] The mold is equipped with an intelligent detection and control system, including a control module, a displacement sensor 19, and a signal transmission unit. The upper end of the pressure ring 17 is equipped with a displacement sensor 19 via an aluminum alloy bracket. A laser displacement sensor (model KEYENCEGT2 series) is selected, with the detection end facing the mold closing area of ​​the punch 4 and the die 3, which can capture the springback contour of the stamped part in real time. The displacement sensor 19 is covered with a waterproof and dustproof cover. The control module adopts a PLC controller (model Siemens S7-1200) with an integrated touch screen operation interface. The displacement sensor 19 is connected to the control module via an RS485 bus. Four sets of fine-tuning cylinders 13 are connected to the control module via servo drivers to realize automated closed-loop control of detection data acquisition, compensation calculation, and actuator regulation.

[0024] Example 2: Figure 1 and Figure 4 As shown, a pressure ring 17 is slidably sleeved on the outer wall of the punch 4, and multiple sets of nitrogen springs 18 are installed through the upper end of the upper die base 2. The movable ends of the multiple sets of nitrogen springs 18 are all fixed to the upper end of the pressure ring 17.

[0025] The overall effect of this embodiment is that the blank holder mechanism is used to control the material flow during the stamping process and prevent wrinkling. It includes a blank holder ring 17 and a nitrogen spring 18. The blank holder ring 17 is slidably sleeved on the outer wall of the punch 4. The blank holder ring 17 is made of Q235 steel plate and welded. The inner wall is coated with a molybdenum disulfide lubricating coating to reduce the sliding friction coefficient. Six sets of nitrogen springs 18 are evenly distributed and installed around the upper end of the upper die base 2. The selected model is KALLERX series. Each nitrogen spring 18 has a spring force of 80kN. The movable ends of the multiple sets of nitrogen springs 18 are fixedly connected to the upper end of the blank holder ring 17 by bolts to ensure that the blank holder ring 17 is subjected to balanced force. The blank holder force can be adjusted according to the material thickness.

[0026] The usage and working principle of this device are as follows: Preliminary preparation: Install the upper die holder 2 onto the power equipment and the lower die holder 1 onto the frame. Based on the material parameters of the high-strength steel to be stamped and the structure of the stamped part, simulate the stamping process using Autoform simulation software to determine the springback amount at the four semi-circular angles of the inner wall of the die 3. Machin the reverse compensation curved surface of the forming surface of the insert 9 and install it into the elongated hole 8. Input the stamping process parameters such as blank holder force, cooling temperature, and initial compensation amount through the control module to control the fine-tuning cylinder 13 to push the circular support frame 12 to slide along the guide groove 10, thereby moving the insert 9 to the initial compensation position. At this time, the buffer spring 14 is in a pre-compressed state. Material loading and mold closing: Place the high-strength steel plate on the positioning table of the die 3, start the stamping equipment, the upper die seat 2 drives the punch 4 to move down along the guide column 6, and at the same time the nitrogen spring 18 pushes the blank holder 17 to move down synchronously. The blank holder 17 first contacts the plate and applies a preset blank holder force to achieve material pre-constraint. Stamping and buffering: The upper die holder 2 continues to descend, and the punch 4 extends into the die 3 to stamp the sheet metal. The impact load generated during the stamping process is transmitted to the buffer rod 15 through the insert 9. The buffer rod 15 pushes the circular plate 16 to compress the buffer spring 14. The spring deformation absorbs the impact energy and avoids rigid impact damage to the parts. In the hot stamping scenario, the cooling mechanism 5 is activated, and coolant is delivered to the cooling pipe through the circulating water pump to quickly and evenly cool the die 3 and the formed parts. The temperature controller adjusts the cooling rate in real time. Springback detection and dynamic compensation: After forming, the upper die holder 2 drives the punch 4 to move upward, the pressure ring 17 resets after a delay, and the displacement sensor 19 detects the springback profile of the stamped part in real time and transmits the detection data to the control module. The control module compares the detection data with the preset standard value. If the springback exceeds the tolerance, it immediately calculates the compensation amount and sends a command to the corresponding fine-tuning cylinder 13. The fine-tuning cylinder 13 pushes the round support frame 12 and the insert 9 to make fine adjustments until the accuracy requirements are met. Material feeding and cycle: After compensation is completed, the pressure ring 17 is reset, the formed stamped part is taken out, and the next stamping cycle begins.

[0027] The above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from the technical solution of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A springback compensation forming die for high-strength steel stamping parts for automobiles, comprising a lower die base (1) and an upper die base (2), characterized in that: The upper end of the lower mold base (1) is equipped with a concave mold (3), the lower end of the upper mold base (2) is equipped with a convex mold (4), the concave mold (3) is equipped with a limit seat (7) at each of the four semi-circular angles of the outer wall, the concave mold (3) is provided with a long hole (8) at each of the four semi-circular angles of the inner wall, the four sets of long holes (8) are slidably equipped with inserts (9), the four sets of long holes (8) are slidably equipped with round support frames (12), the four sets of limit seats (7) are all provided with a fine-tuning cylinder (13) at one end, the four sets of round support frames (12) are all provided with a buffer spring (14), the four sets of round support frames (12) are all provided with a buffer rod (15) at one end, and the four sets of round support frames (12) are all provided with a round plate (16).

2. The springback compensation forming die for high-strength steel stamping parts for automobiles according to claim 1, characterized in that: The extended ends of the four sets of fine-tuning cylinders (13) are respectively fixed to the other ends of the four sets of circular support frames (12), and one end of the multiple sets of buffer rods (15) is respectively fixed to one end of the four sets of inserts (9).

3. The springback compensation forming die for high-strength steel stamping parts for automobiles according to claim 2, characterized in that: The other end of the multiple sets of buffer rods (15) is fixed to one end of the four sets of circular plates (16), and the other end of the four sets of buffer springs (14) is in contact with the other end of the four sets of circular plates (16).

4. The springback compensation forming die for high-strength steel stamping parts for automobiles according to claim 1, characterized in that: The four sets of elongated holes (8) have two sets of guide grooves (10) inside. The eight sets of guide grooves (10) are all slidably installed with guide blocks (11). One end of each pair of guide blocks (11) is fixed to the outer wall of a set of circular support frames (12).

5. The springback compensation forming die for high-strength steel stamping parts for automobiles according to claim 1, characterized in that: The outer wall of the punch (4) is slidably fitted with a pressure ring (17), and multiple sets of nitrogen springs (18) are installed through the upper end of the upper die base (2). The movable ends of the multiple sets of nitrogen springs (18) are fixed to the upper end of the pressure ring (17).

6. The springback compensation forming die for high-strength steel stamping parts for automobiles according to claim 1, characterized in that: The upper mold base (2) is located above the lower mold base (1). A part of the punch (4) is disposed inside the die (3). A cooling mechanism (5) is installed at one end of the lower mold base (1). A part of the cooling mechanism (5) is disposed inside the lower mold base (1). Guide pillars (6) are slidably installed through the upper end of the upper mold base (2). The lower ends of the four sets of guide pillars (6) are fixed to the upper end of the lower mold base (1).

7. The springback compensation forming die for high-strength steel stamping parts for automobiles according to claim 5, characterized in that: It also includes a control module. A displacement sensor (19) is installed on the upper end of the pressure ring (17). The displacement sensor (19) is connected to the control module. All four sets of fine-tuning cylinders (13) are connected to the control module.

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