A method for manufacturing an ultra-high strength steel profiled part with a through hole

Abstract

The application belongs to the field of preparation of special-shaped parts with through holes, and discloses a preparation method of super-high-strength steel special-shaped parts with through holes, which simplifies the process and improves the preparation efficiency. The preparation method comprises the following steps: placing a plate body on a lower convex die; the plate body is a steel plate in austenite state at high temperature; using a hot press forming process, lowering an upper die seat and an upper concave die, pressing the plate body on both sides by using the upper concave die, and manufacturing side flanges; lowering the upper die seat, using a push rod with a punch to manufacture a through hole with a lower flange on the body; opening a cooling system in the upper concave die and the lower convex die, quenching the plate body, and forming a martensite steel plate; raising the upper die seat, driving the push rod to rise, making the punch automatically fall off, then raising the upper concave die, and completing the preparation of the special-shaped part.

Description

Technical Field

[0001] This invention belongs to the field of fabrication of irregularly shaped parts with through holes, specifically, it relates to a method for fabricating an ultra-high strength steel irregularly shaped part with through holes. Background Technology

[0002] The integrated crossbeams and subframes of new energy vehicle chassis require high-strength impact resistance, while their surfaces need dense mounting holes for chassis suspension components, requiring direct tapping to withstand high torque. The hinges of the A-pillars and B-pillars, and the seatbelt fixing points, require an additional, extremely thick reinforcing plate welded on.

[0003] The current standard practice in factories is as follows: first, the part is stamped using a hot stamping die and then hardened; after demolding, ordinary flat holes are cut out using a laser; finally, it is sent to the welding station where an automatic welding gun forcibly welds a nut around the flat holes, which is used to connect with other parts. The disadvantage of this approach is that it involves many steps and requires expensive laser cutting equipment. If high-strength bushings could be manufactured directly, the process could be simplified and costs could be saved. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing ultra-high strength steel irregular parts with through holes, which simplifies the process and improves the preparation efficiency.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for preparing an ultra-high strength steel irregular part with through holes, the irregular part including a body and side flanges located on both sides of the body and connected to the body, the body having through holes with downward flanges; The method includes: Step 1: Place the plate on the lower punch; the plate is an austenitic steel plate at high temperature; the surface of the plate is coated with an aluminum-silicon coating; the upper die is connected to the upper die base; Step 2: Using the hot pressing forming process, lower the upper mold base and the upper die, and use the upper die to press down on both sides of the plate to form side flanges; the distance between the upper mold base and the upper die remains unchanged; Step 3: Lower the upper mold base and use the push rod with the punch to make a through hole with a downward flange on the body; Step 4: Activate the cooling system in the upper die and lower punch to quench the plate and form a martensitic steel plate; the martensitic steel plate is an ultra-high strength steel. Step 5: Raise the upper die base, which will drive the push rod to rise, causing the punch to fall off automatically. Then raise the upper die cavity to complete the preparation of the irregular part.

[0006] As a preferred embodiment, the punch includes a cylindrical punch body and a conical punch tip. The punch tip is fixedly connected to the bottom surface of the punch body, and the top diameter of the punch tip is equal to the outer diameter of the punch body. The top surface of the punch body is provided with an open slot, and the side wall of the open slot is provided with a positioning groove. The lower side of the push rod is provided with a cavity, and a snap-fit ​​assembly is provided in the cavity. The punch and the push rod are adapted to be connected through the snap-fit ​​assembly and the positioning groove.

[0007] As a preferred example, the snap-fit ​​assembly includes a spring and a positioning ball. One end of the spring is fixedly connected to the inner wall of the cavity, and the other end of the spring is fixedly connected to one end of the positioning ball. The other end of the positioning ball is adapted to the positioning groove.

[0008] As a preferred example, the lower outer diameter of the push rod is smaller than the outer diameter of the punch body, and the outer diameter of the punch body is equal to the diameter of the through hole; the push rod and the punch are coaxially arranged; the height of the punch body is greater than the height of the lower flange.

[0009] As a preferred example, in step 1, the high temperature is 700-950℃; in step 4, the ultra-high strength steel is steel with a tensile strength of 1500-2000MPa; step 3 specifically includes: lowering the push rod and the punch, using the tip of the punch to pierce the body, and using the outer surface of the punch body to stretch the pierced body to form a through hole and a lower flange connected below the through hole.

[0010] As a preferred example, in step 3, after the lower flange is formed, the push rod and punch continue to descend until the top surface of the punch body is below the first blocking member in the travel channel of the lower punch, the push rod stops descending, and the lower part of the push rod is opposite to the through hole and the lower flange; in step 5, the upper die base is raised, which drives the push rod to rise, and the first blocking member applies a downward force to the top surface of the punch body to compress the snap-fit ​​assembly, so that the punch body disengages from the push rod.

[0011] As a preferred example, the travel channel wall of the lower punch is provided with a mounting hole, and the first blocking member is disposed in the mounting hole; each first blocking member includes a first compression spring and a first stop block, one end of the first compression spring is connected to the wall of the mounting hole, the other end of the first compression spring is connected to one end of the first stop block, and the other end of the first stop block is located in the travel channel of the lower punch.

[0012] In a preferred embodiment, the upper mold base is provided with a first feeding channel, and the upper die cavity is provided with a second feeding channel. The first and second feeding channels are connected, and the bottom end of the second feeding channel is connected to the travel channel of the upper die cavity. The top surface of the upper die cavity is provided with a wedge-shaped block, one end of which is provided with a first inclined surface, and the other end with a second inclined surface. The first and second inclined surfaces are arranged opposite to each other and have opposite inclination directions. The bottom surface of the upper mold base is provided with a groove, which is connected to the first feeding channel. The groove is provided with a first limiting block, a second limiting block, a fixing block, a first elastic element, and a second elastic element. The fixing block is fixedly connected to the wall of the groove, and the first limiting block is connected to the fixing block through the first elastic element. The connection is as follows: the second limiting block is connected to the fixed block through the second elastic element; one end of the first limiting block and one end of the second limiting block can both be located in the first feeding channel of the upper mold base; one end face of the first limiting block is adapted to the first inclined surface, and one end face of the second limiting block is adapted to the second inclined surface; the wall of the traveling channel of the upper die is provided with a second mounting hole, which is located below the second feeding channel, and a second blocking element is installed in each second mounting hole; each second blocking element includes a second compression spring and a second stop block, one end of the second compression spring is connected to the wall of the second mounting hole, the other end of the second compression spring is connected to one end of the second stop block, and the other end of the second stop block is located in the traveling channel of the upper die.

[0013] As a preferred example, step 1 further includes: under the action of the first elastic member, the end of the first limiting block extends into the first feeding channel to prevent a new punch from falling; step 3 further includes: one end face of the second limiting block slides downward along the second inclined plane, and the end of the second limiting block facing the first feeding channel moves toward the first feeding channel to prevent the punch located above it from falling; one end face of the first limiting block slides downward along the first inclined plane, and the end of the first limiting block facing the first feeding channel moves away from the first feeding channel, so that a punch located between the first limiting block and the second limiting block falls from the first feeding channel into the second feeding channel of the upper die; step 5 further includes: after the push rod rises above the second feeding channel of the upper die, the punch located in the second feeding channel of the upper die falls onto the second blocking member.

[0014] As a preferred example, the method for preparing the ultra-high strength steel irregular part with through holes further includes step 6: returning to step 1, placing the new plate on the lower punch to prepare the next irregular part, and in step 3, lowering the upper die seat and push rod, and installing the punch located on the second blocking member at the bottom of the push rod.

[0015] Compared with existing technologies, the method for preparing ultra-high strength steel irregular parts with through holes in this invention simplifies the process and improves preparation efficiency. The preparation method of this invention involves placing a plate between a lower punch and an upper die; using a hot pressing process, lowering the upper die holder and the upper die, and using the upper die to press down on both sides of the plate to form side flanges; lowering the upper die holder, and using a push rod with a punch, forming through holes with downward flanges on the plate; activating the cooling system in the upper die and lower punch to quench the plate, forming a martensitic steel plate; raising the upper die holder, driving the push rod to rise, causing the punch to automatically detach, and then raising the upper die to complete the preparation of the irregular part. In existing technologies, a single step can only obtain a hot-pressed part without holes and with side flanges. However, using the technical solution of this invention, a hot-pressed part with side flanges and through holes with downward flanges can be obtained in a single step. The method of this invention forms flanged holes during the hot pressing process, eliminating the need for subsequent laser cutting and welding of upright flanges for tapping holes. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the irregularly shaped component in an embodiment of the present invention; Figure 2 This is a schematic diagram of step 1 in the method of this embodiment of the invention; Figure 3 yes Figure 2 Enlarged view of part A in the middle; Figure 4 yes Figure 2 Enlarged view of part B in the middle; Figure 5 yes Figure 2 Enlarged view of a section in the middle C; Figure 6 This is a schematic diagram of the punch structure in an embodiment of the present invention; Figure 7 This is an assembly diagram of the push rod and the punch in an embodiment of the present invention; Figure 8 This is a schematic diagram of step 2 in the method of this embodiment of the invention; Figure 9 This is a schematic diagram of the upper mold base descending in step 3 of the method of this embodiment of the invention; Figure 10 In step 3 of the method in this embodiment of the invention, the upper mold base is... Figure 9 A diagram illustrating a continued descent based on the existing foundation; Figure 11 In step 3 of the method in this embodiment of the invention, the upper mold base is... Figure 10 A diagram illustrating a continued descent based on the existing foundation; Figure 12 yes Figure 11 Enlarged view of a section in part D; Figure 13In step 3 of the method of this embodiment of the invention, the upper mold base is... Figure 11 A diagram illustrating a continued descent based on the existing foundation; Figure 14 This is a schematic diagram of the upper mold base descending to its lowest position in step 3 of the method of this embodiment of the invention; Figure 15 yes Figure 14 A magnified view of part E in the middle.

[0017] The diagram shows: body 1, side flange 2, lower flange 3, through hole 4, punch 5, punch body 51, punch tip 52, push rod 6, snap-fit ​​assembly 7, spring 71, positioning ball 72, first blocking component 8, first compression spring 81, first stop block 82, lower punch 9, upper die 10, second feeding channel 101, wedge block 102, first inclined surface 103, second inclined surface 104, upper die base 11, first feeding channel 111, first limiting block 112, second limiting block 113, fixing block 114, first elastic component 115, second elastic component 116, second blocking component 12, second compression spring 121, and second stop block 122. Detailed Implementation

[0018] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] like Figure 1 As shown, the irregularly shaped part prepared according to an embodiment of the present invention includes a body 1 and a side flange 2 connected to the body 1. The body 1 has a through hole 4 with a downward flange 3. The method of the present invention requires opening a through hole in the body 1, and the downward flange 3 is provided below the through hole. Preferably, the side flange 2 is L-shaped. Of course, depending on the product requirements, the side flange 2 can also be other shapes. Preferably, a side flange 2 is provided on each side of the body 1.

[0020] A method for preparing an ultra-high strength steel irregular part with through holes according to an embodiment of the present invention includes: Step 1, as follows Figure 2 As shown, the plate is placed on the lower punch 9; the plate is an austenitic steel plate in a high-temperature state. The surface of the plate is coated with an aluminum-silicon coating. The aluminum-silicon coating is used to prevent high-temperature oxidation and decarburization. The upper die 10 is connected to the upper die base 11. The tensile strength of the austenitic steel plate in a high-temperature state is 50-100 MPa. The austenitic steel plate has low tensile strength and is easy to form in a high-temperature environment.

[0021] Step 2, as follows Figure 8 As shown, using a hot pressing forming process, the upper mold base 11 and the upper die 10 are lowered, and the upper die 10 is used to press down on both sides of the plate body to form the side flange 2; the distance between the upper mold base 11 and the upper die 10 remains unchanged.

[0022] Step 3: Lower the upper mold base 11, and use the push rod 6 with punch 5 to create a through hole 4 with a downward flange 3 on the body 1; Figure 9 , Figure 10 , Figure 11 , Figure 13 and Figure 14 As shown, the upper die holder 11 gradually descends to its lowest position. The upper die holder 11 descends from its initial position. The initial position is the highest position of the upper die holder 11, at which point the push rod has not yet been fitted with a new punch.

[0023] Step 4: Activate the cooling systems in the upper die 10 and lower die 9 to quench the plate and form a martensitic steel plate; the martensitic steel plate is ultra-high strength steel. Ultra-high strength steel is steel with a tensile strength between 1500 and 2000 MPa at room temperature. Room temperature is 18 to 25°C.

[0024] Step 5: Raise the upper mold base 11, which will drive the push rod 6 to rise, causing the punch 5 to fall off automatically. Then raise the upper die 10 to complete the preparation of the irregular part.

[0025] In the above embodiment, the upper die 10 and the upper die base 11 are connected by a nitrogen spring. The punch 5 is detachably connected to the bottom end of the push rod 6. The push rod 6 and the upper die base 11 are fixedly connected. The upper die 10 and the lower punch 9 are respectively provided with interconnected, perpendicularly axial travel channels for the push rod 6 and the punch 5 to pass through. Throughout the entire operation, the position of the lower punch 9 is fixed.

[0026] In the above embodiment, step 1: the plate is placed above the lower punch 9, between the lower punch 9 and the upper die 10. Step 2: using a hot pressing forming process, the upper die base 11 and the upper die 10 are lowered, and the upper die 10 presses down on both sides of the plate to form side flanges 2; the body 1 is located between the side flanges 2. During this process, the upper die base 11 and the upper die 10 are lowered synchronously, and the distance between the upper die base 11 and the upper die 10 remains unchanged; the distance between the upper die 10 and the lower punch 9 gradually decreases until the upper die 10 presses down on both sides of the plate to form side flanges 2. Step 3: the upper die base 11 is lowered, and a through hole 4 with a downward flange 3 is formed on the body 1 using a push rod 6 with a punch 5. During this process, the upper die 10 is located on the plate and its position remains unchanged; the upper die base 11 is lowered, driving the push rod 6 to be lowered, and the punch 5 located at the bottom end of the push rod 6 is used to form a through hole 4 with a downward flange 3 on the body 1. At this point, the bottom end of push rod 6 and punch 5 descend into the travel channel of lower punch 9. Under high temperature conditions, some of the aluminum-silicon coating on the plate surface adheres to punch 5. Step 4: Activate the cooling systems in upper die 10 and lower punch 9 to quench the plate, forming a martensitic steel plate. The purpose of quenching is to transform the austenitic steel plate into a martensitic steel plate.

[0027] Step 5: Raise the upper die holder 11, causing the push rod 6 to rise, which automatically dislodges the punch 5. Then, raise the upper die 10 to complete the preparation of the irregular part. In this step, because the surface of the punch 5 is coated with an aluminum-silicon layer when it is made into a hole, it cannot be reused. Therefore, the punch 5 is disengaged from the push rod 6. At the same time, the outer diameter of the punch body 51 with the aluminum-silicon coating on its outer surface is larger than the inner diameter of the lower flange 3. If the punch 5 moves back to its original position with the push rod 6, it will inevitably damage the lower flange 3. Therefore, in step 5, the punch 5 is disengaged from the push rod 6 below the lower flange. Only when the push rod 6 rises will the punch 5 fall, thus protecting the prepared lower flange.

[0028] The irregularly shaped part prepared by the method of the above embodiment has a through hole 4 on the body 1, and a lower flange 3 is connected below the through hole 4. If the surface of the lower flange 3 can be tapped, then the lower flange is equivalent to a nut. The prepared irregularly shaped part does not require laser cutting or nut welding. If the height of the lower flange 3 is insufficient to tap, then the nut needs to be welded later, but the laser cutting process can be saved. From the perspective of the preparation process, the present invention saves steps and improves the preparation efficiency.

[0029] Preferred, such as Figure 6 As shown, the punch 5 includes a cylindrical punch body 51 and a conical punch tip 52. The punch tip 52 is fixedly connected to the bottom surface of the punch body 51, and the top diameter of the punch tip 52 is equal to the outer diameter of the punch body 51. The top surface of the punch body 51 is provided with an open groove, and the sidewall of the open groove is provided with a positioning groove. Figure 7 As shown, the lower side of the push rod 6 has a cavity, and the cavity has a snap-fit ​​assembly 7. The punch 5 and the push rod 6 are connected by the snap-fit ​​assembly 7 and the positioning groove.

[0030] In the preferred embodiment described above, the punch tip 52 of the punch 5 pierces the body 1, thereby creating a through hole 4 in the body 1. The punch body 51 stretches the material originally located at the through hole 4. An annular groove is provided at the upper part of the travel channel of the lower punch 9, allowing this portion of the material to flow in the annular groove. The diameter of the through hole 4 thus created is equal to the outer diameter of the punch body 51. Since a new punch 5 needs to be replaced each time the push rod 6 punches the plate, a detachable connection is used between the push rod 6 and the punch 5. An opening groove is provided on the top surface of the punch body 51, and a positioning groove is provided on the side wall of the opening groove. A cavity is provided on the lower side of the push rod 6, and a snap-fit ​​assembly 7 is provided in the cavity. The punch 5 and the push rod 6 are connected by the snap-fit ​​assembly 7 and the positioning groove. When the push rod 6 moves downward while the punch 5 remains stationary, the locking component 7 of the push rod 6 touches the opening slot of the punch body 51 and deforms. The push rod 6 then drives the locking component 7 to continue moving downward, so that the locking component 7 is located in the opening slot and matches the positioning slot, thus connecting the punch 5 and the push rod 6.

[0031] Preferred, such as Figure 7As shown, the locking assembly 7 includes a spring 71 and a positioning ball 72. One end of the spring 71 is fixedly connected to the inner wall of the cavity, and the other end of the spring 71 is fixedly connected to one end of the positioning ball 72. The other end of the positioning ball 72 is adapted to the positioning groove. Preferably, the free end of the positioning ball 72 facing outward is an arc-shaped surface. This facilitates the adaptation of the positioning ball 72 to the positioning groove, making it easy to slide into or out of the positioning groove. Two or three locking assemblies 7 can be provided. The position of the positioning ball 72 is changed by the deformation of the spring 71. When the locking assembly 7 of the push rod 6 touches the opening groove of the punch body 51, the push rod 6 drives the locking assembly 7 to continue to move downward, the spring 71 is compressed, and the positioning ball 72 moves inward. When the positioning ball 72 is opposite to the positioning groove, the spring 71 expands, so that one end of the positioning ball 72 abuts in the positioning groove, thereby realizing the connection between the punch 5 and the push rod 6. As the push rod 6 continues to move downward, the push rod 6 drives the punch 5 to move downward together.

[0032] Preferably, the lower outer diameter of the push rod 6 is smaller than the outer diameter of the punch body 51, and the outer diameter of the punch body 51 is equal to the diameter of the through hole 4; the push rod 6 and the punch 5 are coaxially arranged; the height of the punch body 51 is greater than the height of the lower flange 3. The punch body 51 is used to stretch the material to form the lower flange 3. The punch body 51 is in direct contact with the material. The lower outer diameter of the push rod 6 is smaller than the outer diameter of the punch body 51. Since the push rod 6 is located above the punch body 51, when it moves downward, the lower part of the push rod 6 will not directly contact the material of the body 1. The lower surface of the push rod 6 will not be coated with an aluminum-silicon coating. The push rod 6 and the punch 5 are coaxially arranged so that the lower part of the push rod 6 will not contact the material of the body 1. The height of the punch body 51 is greater than the height of the lower flange 3. This allows the punch body 51 to stretch the material and form the lower flange 3.

[0033] Preferably, in step 1, the high temperature is 700–950°C, for example, 800°C, 900°C, 920°C, or 950°C. Steps 1 to 3 require maintaining the temperature of the plate and keeping it in the austenitic state; after cooling and quenching in step 4, the plate transforms from an austenitic steel plate into a martensitic steel plate. Maintaining a plate temperature of 700–950°C ensures that the austenitic state of the plate is preserved during the forming process in steps 1 to 3, preventing it from transforming into a martensitic state and preserving the plate's good ductility and low strength. Austenitic steel plates at high temperatures have low tensile strength and are easy to form; martensitic steel plates have high hardness and high tensile strength, making them ultra-high-strength steels.

[0034] Step 3 specifically includes: lowering the push rod 6 and the punch 5, using the tip 52 of the punch to pierce the body 1, and using the outer surface of the punch body 51 to stretch the pierced body 1, forming a through hole 4 and a lower flange 3 connected below the through hole 4. During this process, the tip 52 of the punch contacts the body 1, piercing it. During the downward movement, the outer surface of the punch body 51 stretches the material of the pierced body 1, i.e., the material originally located at the through hole position, forming the through hole 4 and the lower flange 3. During this process, the push rod 6 does not directly contact the material. The push rod 6 is reusable.

[0035] During operation, the punch 5 is in direct contact with the material of the body 1, and its surface is coated with an aluminum-silicon layer, making the punch 5 unusable. Preferably, in step 3, after forming the lower flange 3, the push rod 6 and the punch 5 continue to descend until the top surface of the punch body 51 is below the first blocking member 8 in the travel channel of the lower punch 9. The push rod 6 stops descending, and its lower part is opposite to the through hole 4 and the lower flange 3. In step 5, the upper die holder 11 is raised, driving the push rod 6 to rise. The first blocking member 8 applies a downward force to the top surface of the punch body 51, compressing the locking assembly 7, causing the punch body 51 to disengage from the push rod 6. Once the through hole 4 and the lower flange 3 are formed, the function of the punch 5 is complete. The push rod 6 and the punch 5 continue to descend until the top surface of the punch body 51 is below the first blocking member 8 in the travel channel of the lower punch 9. The punch 5 is disengaged from the push rod 6 by the first blocking member 8, and the punch 5 falls in the travel channel of the lower punch 9. The push rod 6 returns to its initial position.

[0036] Preferred, such as Figure 5As shown, the lower punch 9 has mounting holes on its travel channel wall, and the first blocking member 8 is disposed in the mounting holes. Each first blocking member 8 includes a first compression spring 81 and a first stop block 82. One end of the first compression spring 81 is connected to the wall of the mounting hole, and the other end of the first compression spring 81 is connected to one end of the first stop block 82. The other end of the first stop block 82 is located in the travel channel of the lower punch 9. When the punch 5 moves downward and contacts the first blocking member 8, the first compression spring 81 is compressed under the downward pressure of the punch 5, and the first stop block 82 moves towards the mounting hole. When the punch 5 moves downward below the first blocking member 8, the first compression spring 81 extends a certain length, and under the action of lateral pressure, the first stop block 82 moves towards the push rod, so that the first stop block 82 is located above the punch body 51. At this time, the end of the first stop block 82 does not contact the push rod 6 to avoid the first stop block 82 scraping the push rod 6. When the push rod moves upward, the first stop 82 blocks the upward movement of the punch body 51 and applies a downward force to the punch body 51, causing the spring 71 of the snap-fit ​​assembly 7 on the push rod to contract, and the positioning ball 72 to move out of the positioning groove of the punch body 51, thereby disengaging the punch 5 from the push rod. In other words, after the punch 5 completes the opening of the through hole and the downward flange on the body, because the surface of the punch 5 is in contact with the material of the body, and because some material adheres to the surface of the punch 5, it cannot be reused, so it needs to be detached from the push rod. Preferably, one end face of the first stop 82 facing the travel channel of the lower punch 9 is inclined, and from bottom to top, this end face slopes from the center line of the travel channel near the lower punch 9 to the direction away from the center line of the travel channel of the lower punch 9. This facilitates the movement of the punch 5 below the first stop 82 and makes it difficult to move upward from below the first stop 82.

[0037] After the punch detaches from the push rod, to automatically install a new punch onto the push rod, preferably, as follows: Figure 2 As shown, the upper mold base 11 is provided with a first feeding channel 111, and the upper die 10 is provided with a second feeding channel 101. The first feeding channel 111 and the second feeding channel 101 are connected, and the bottom end of the second feeding channel 101 is connected to the travel channel of the upper die 10. The top surface of the upper die 10 is provided with a wedge block 102. One end of the wedge block 102 is provided with a first inclined surface 103, and the other end is provided with a second inclined surface 104; the first inclined surface 103 and the second inclined surface 104 are arranged opposite to each other and have opposite inclination directions. Figure 3As shown, the bottom surface of the upper mold base 11 is provided with a groove, which communicates with the first feeding channel 111; the groove is provided with a first limiting block 112, a second limiting block 113, a fixing block 114, a first elastic element 115, and a second elastic element 116. The fixing block 114 is fixedly connected to the wall of the groove. The first limiting block 112 is connected to the fixing block 114 through the first elastic element 115, and the second limiting block 113 is connected to the fixing block 114 through the second elastic element 116. One end of the first limiting block 112 and one end of the second limiting block 113 can both be located in the first feeding channel 111 of the upper mold base 11; one end face of the first limiting block 112 is adapted to the first inclined surface 103, and one end face of the second limiting block 113 is adapted to the second inclined surface 104. Figure 4 As shown, the upper die 10 has a second mounting hole on its travel channel wall, located below the second feeding channel 101. Each second mounting hole houses a second blocking member 12. Each second blocking member 12 includes a second compression spring 121 and a second stop 122. One end of the second compression spring 121 is connected to the wall of the second mounting hole, and the other end is connected to one end of the second stop 122. The other end of the second stop 122 is located in the travel channel of the upper die 10. Preferably, the end face of the second stop 122 facing the travel channel of the upper die 10 is inclined, and from bottom to top, this end face slopes from near the center line of the travel channel of the upper die 10 towards the direction away from the center line of the travel channel of the upper die 10. This facilitates the second stop 122 receiving new punches 5 and ensures that new punches 5 move smoothly from above the second stop 122 to below the second stop 122. Figure 3 As shown, the first limiting block 112 has two oblong holes and two positioning pins. The positioning pins are fixedly connected to the groove wall, with one oblong hole and one positioning pin fitting together. The axes of the first elastic member 115 and the oblong holes are both horizontal. Under the action of the first elastic member and the first inclined surface, the first limiting block 112 moves horizontally. Similarly, the second limiting block 113 has oblong holes and positioning pins, so that the second limiting block 113 moves horizontally under the action of the second elastic member and the second inclined surface.

[0038] In the preferred embodiment described above, the first feeding channel 111, the second feeding channel 101, and the travel channel of the upper die 10 are interconnected. A new punch is placed in the first feeding channel 111 of the upper die holder 11. Each time a non-shaped part is prepared, a new punch slides out from the first feeding channel 111, passes through the second feeding channel 101, and slides into the travel channel of the upper die 10 to achieve installation with the push rod.

[0039] In the preferred embodiment described above, the top surface of the upper die 10 is provided with a wedge-shaped block 102. One end of the wedge-shaped block 102 is provided with a first inclined surface 103, and the other end is provided with a second inclined surface 104. The second inclined surface 104 and the first inclined surface 103 are arranged opposite to each other and have opposite inclination directions.

[0040] In the preferred embodiment described above, the first limiting block 112 is connected to the fixed block 114 via the first elastic element 115, and the second limiting block 113 is connected to the fixed block 114 via the second elastic element 116. One end face of the first limiting block 112 is adapted to the first inclined surface 103, and one end face of the second limiting block 113 is adapted to the second inclined surface 104. When the upper mold base 11 moves up and down, the first limiting block 112 and the second limiting block 113 slide along the first inclined surface 103 and the second inclined surface 104, respectively. The first elastic element 115 and the second elastic element 116 are provided mainly for resetting the first limiting block 112 and the second limiting block 113. The first limiting block 112 and the second limiting block 113 move in opposite directions. When the first limiting block 112 moves towards the first feeding channel 111, the second limiting block 113 moves away from the first feeding channel 111. Depending on the moving position, one end of the first limiting block 112 can be located in the first feeding channel 111 of the upper mold base 11, and one end of the second limiting block 113 can also be located in the first feeding channel 111 of the upper mold base 11.

[0041] like Figure 10 As shown, if the upper die holder 11 does not move towards the upper die cavity 10, the wedge block 102 of the upper die cavity 10 and the first limiting block 112 and the second limiting block 113 of the upper die holder 11 are not in contact. At this time, under the action of the first elastic member 115, the end of the first limiting block 112 extends into the first feeding channel 111, preventing all punches 5 in the first feeding channel from falling. Under the action of the second elastic member 116, the second limiting block 113 is entirely located in the groove.

[0042] like Figures 11 to 15 As shown, if the upper die holder 11 moves downward, the first limiting block 112 moves downward along the first inclined surface 103, and the second limiting block 113 moves downward along the second inclined surface 104. Then, the length of the second elastic member 116 decreases, and the second limiting block 113 connected to the second elastic member 116 moves toward one end of the first feeding channel 111 into the first feeding channel 111, preventing the punch 5 located above it from falling. The length of the first elastic member 115 decreases, and the first limiting block 112 connected to the first elastic member 115 moves away from the first feeding channel 111 toward one end of the first feeding channel 111, thereby releasing a punch 5 located between the second limiting block 113 and the first limiting block 112. The punch 5 slides into the second feeding channel 101 of the upper die 10.

[0043] like Figure 2and Figure 3 As shown, if the upper die holder 11 moves upward and away from the upper die 10, the first limiting block 112 moves upward along the first inclined surface 103, and the second limiting block 113 moves upward along the second inclined surface 104. Then, the length of the second elastic member 116 increases, and the second limiting block 113, connected to the second elastic member 116, moves away from the first feeding channel 111 at one end, causing the punch above it to fall. The length of the first elastic member 115 also increases, and the first limiting block 112, connected to the first elastic member 115, moves towards the first feeding channel 111 at one end, preventing the punch above it from falling. During this process, before one end of the second limiting block 113 completely moves out of the first feeding channel 111, one end of the first limiting block 112 has already entered the first feeding channel 111. Thus, all punches are intercepted by the first limiting block 112.

[0044] In the preferred embodiment described above, the wall of the travel channel of the upper die 10 is provided with a second mounting hole, which is located below the second feeding channel 101. A second blocking member 12 is installed in each second mounting hole. Each second blocking member 12 includes a second compression spring 121 and a second stop 122. One end of the second compression spring 121 is connected to the wall of the second mounting hole, and the other end of the second compression spring 121 is connected to one end of the second stop 122. The other end of the second stop 122 is located in the travel channel of the upper die 10. The second blocking member 12 serves to support the punch that slides down from the second feeding channel 101 into the travel channel of the upper die 10. Meanwhile, as... Figure 8 and Figure 9 As shown, the connection between the push rod and the new punch is completed on the second blocking member 12. When no punch is located on the second blocking member 12, the second compression spring 121 connects to the second stop block 122, so that one end of the second stop block 122 is located in the travel channel of the upper die 10. The end of the second stop block 122 will not interfere with the position of the push rod, nor will it contact the push rod. When the punch slides down from the second feeding channel 101 into the travel channel of the upper die 10 and lands on the end of the second stop block 122, the end of the second stop block 122 abuts against the tip of the punch. When the push rod 6 moves downward, the locking component 7 of the push rod 6 touches the opening slot of the punch body 51 and deforms. The push rod 6 drives the locking component 7 to continue to move downward, so that the locking component 7 is located in the opening slot and matches the positioning slot of the punch 5, realizing the connection between the punch 5 and the push rod 6. After connection, the push rod 6 and the punch 5 move downward together. The downward-moving punch 5 applies a lateral force to the second stop 122, causing the second compression spring 121 to contract. The second stop 122 moves away from the travel channel of the upper die 10 until the punch 5 completely disengages from the second stop 12. Under the action of the second compression spring 121, the second stop 122 returns to its initial position to receive the next new punch.

[0045] Preferably, step 1 further includes: Figure 2 and Figure 3 As shown, under the action of the first elastic member 115, the end of the first limiting block 112 extends into the first feeding channel 111, preventing the new punch 5 from falling. Simultaneously with placing the plate in step 1, the pre-installation of the new punch is achieved. That is, the new punch is placed into the first feeding channel 111 of the upper die holder 11. Multiple new punches can be pre-placed in the first feeding channel 111. The first limiting block 112 retains the new punch in the first feeding channel 111 of the upper die holder 11, preventing it from sliding into the second feeding channel 101.

[0046] Preferably, step 3 further includes: Figure 11 , Figure 12 , Figure 13 , Figure 14 and Figure 15 As shown, one end face of the second limiting block 113 slides downward along the second inclined plane 104, and the end of the second limiting block 113 facing the first feeding channel 111 moves towards the first feeding channel 111, preventing the punch 5 located above it from falling; one end face of the first limiting block 112 slides downward along the first inclined plane 103, and the end of the first limiting block 112 facing the first feeding channel 111 moves away from the first feeding channel 111, causing a punch 5 located between the first limiting block 112 and the second limiting block 113 to fall from the first feeding channel 111 to the bottom end of the second feeding channel 101 of the upper die 10. During step 3, a new punch is positioned at the bottom end of the second feeding channel 101. In step 2, the upper die holder 11 and the upper die 10 are lowered, but the distance between the upper die holder 11 and the upper die 10 remains unchanged. The new punch is still trapped in the first feeding channel 111 of the upper die holder 11 by the first limiting block 112. Figure 11 and Figure 12 As shown, one end of the first limiting block 112 is located in the first feeding channel 111, and the second limiting block 113 is located in the groove. At this time, the second limiting block 113 contacts the second inclined surface 104 earlier than the first limiting block 112 contacts the first inclined surface 103. That is, the second limiting block 113 displaces before the first limiting block 112, so that before the end of the first limiting block 112 moves out of the first feeding channel 111, the end of the second limiting block 113 has already entered the first feeding channel 111, intercepting the punch located above the second limiting block 113. Figure 13 As shown, the end of the first limiting block 112 moves to the right, and the end of the second limiting block 113 moves to the left. Before the end of the first limiting block 112 moves out of the first feeding channel 111, the end of the second limiting block 113 has already entered the first feeding channel 111. Figure 14 and Figure 15As shown, the end of the first limiting block 112 moves to its rightmost position, and the end of the second limiting block 113 moves to its leftmost position. At this time, the end of the first limiting block 112 is completely removed from the first feeding channel 111, and the end of the second limiting block 113 is completely inserted into the first feeding channel 111. The new punch, which was originally located between the first limiting block 112 and the second limiting block 113, slides out of the first feeding channel 111 and falls into the second feeding channel 101.

[0047] Preferably, step 5 further includes: after the push rod 6 rises above the second feeding channel 101 of the upper die 10, the punch 5 located in the second feeding channel 101 of the upper die 10 falls onto the second blocking member 12. In step 5, the punch 5 automatically falls off, the push rod returns to its original position, and a new punch automatically falls onto the second blocking member 12 from the bottom end of the second feeding channel 101. The new punch is in a ready-to-install state. In step 5, as the upper die holder 11 rises and the upper die holder 11 disengages from the upper punch 10, the punches in the first feeding channel 111 generally descend by one punch position, from... Figure 14 The state becomes Figure 2 The state. Specifically, such as Figure 13 As shown, during this process, the first limiting block 112 moves to the left, and the second limiting block 113 moves to the right. When the first limiting block 112 reaches its left limit position, a portion of the end of the second limiting block 113 is still within the first feeding channel 111. This ensures that after the first limiting block 112 is in place, the punch placed on it is released through the second limiting block 113. As the upper die holder 11 continues to rise, the second limiting block 113 continues to move to the right until it reaches its right limit position, at which point the second limiting block 113 completely exits the first feeding channel 111. In this way, the new punch released by the second limiting block 113 lands on the first limiting block 112.

[0048] Preferably, the preparation method further includes step 6: returning to step 1, placing the new plate on the lower punch 9 to prepare the next irregular part, and in step 3, lowering the upper die holder 11 and the push rod 6, and installing the punch 5 located on the second blocking member 12 at the bottom of the push rod 6. After completing the preparation of one irregular part in step 5, returning to step 1 to prepare the next new irregular part, and so on, until the preparation is completed. A new punch is used each time a new irregular part is prepared. In step 3, before making the through hole 4 with the lower flange 3, the new punch 5 is first installed at the bottom of the push rod 6. Using the push rod 6 with the punch 5, the through hole 4 with the lower flange 3 is made on the body 1.

[0049] In step 5, the upper die holder 11 is first raised. After the upper die holder 11 rises to its initial distance from the upper die cavity 10, the upper die holder 11 and the upper die cavity 10 are raised simultaneously until the distance between the upper die cavity 10 and the lower punch 9 is the initial distance. During the raising of the upper die holder 11, a new punch located in the second feeding channel 101 of the upper die cavity 10 falls onto the second blocking member 12, and the first limiting block 112 intercepts the new punch in the first feeding channel 111.

[0050] After forming, automotive hot-formed steel undergoes rapid quenching and cooling, transforming from austenite to martensite. This process involves significant volume change, making the freshly flanged upright flange prone to jamming against the punch. During the punch's return stroke, it can easily interfere with and jam against the hole wall, leading not only to punch breakage but also damage to the newly formed flanged upright flange. In this embodiment of the invention, the push rod does not directly contact the body or the lower flanged flange connected below the through hole. Only the punch directly contacts the body material. The punch body 51 stretches the material originally located at the through hole position to form the lower flanged flange.

[0051] The surface of automotive hot-formed steel is generally coated with an anti-oxidation aluminum-silicon coating. At high temperatures, this coating softens and becomes extremely sticky, easily adhering to the surface of the flanging punch during continuous operation. Once hardened aluminum-silicon nodules form on the punch surface, the inner walls of the flanging holes produced subsequently will be severely scratched, leading to stripping. In this invention, only the punch is in direct contact with the body material. During the manufacturing process, the aluminum-silicon coating adheres to the surface of the punch. After manufacturing the irregular part, the punch is detached from the push rod; when manufacturing the next irregular part, a new punch is installed. This does not affect the next manufacturing of irregular parts.

[0052] Those skilled in the art should understand that the present invention is not limited to the specific embodiments described above, and the specific embodiments and description in the specification are merely for further illustrating the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing an ultra-high strength steel irregularly shaped part with through holes, characterized in that, The irregular part includes a body (1) and side flanges (2) located on both sides of the body (1) and connected to the body (1). The body (1) is provided with through holes (4) with lower flanges (3). The method includes: Step 1: Place the plate on the lower punch (9); the plate is a steel plate in the austenitic state at high temperature; the surface of the plate is an aluminum-silicon coating; the upper die (10) is connected to the upper die base (11); Step 2: Using hot pressing forming process, lower the upper mold base (11) and the upper die (10), and use the upper die (10) to press down on both sides of the plate body to form side flanges (2); the distance between the upper mold base (11) and the upper die (10) remains unchanged; Step 3: Lower the upper mold base (11) and use the push rod (6) with punch (5) to make a through hole (4) with a lower flange (3) on the body (1). Step 4: Activate the cooling system in the upper die (10) and lower punch (9) to quench the plate and form a martensitic steel plate; the martensitic steel plate is ultra-high strength steel; Step 5: Raise the upper mold base (11) to drive the push rod (6) to rise, so that the punch (5) will fall off automatically. Then raise the upper die (10) to complete the preparation of the irregular part.

2. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 1, characterized in that, The punch (5) includes a cylindrical punch body (51) and a conical punch tip (52). The punch tip (52) is fixedly connected to the bottom surface of the punch body (51). The top surface diameter of the punch tip (52) is equal to the outer diameter of the punch body (51). The top surface of the punch body (51) is provided with an opening groove, and the side wall of the opening groove is provided with a positioning groove. The lower side of the push rod (6) is provided with a cavity, and a snap-fit ​​assembly (7) is provided in the cavity. The punch (5) and the push rod (6) are connected by the snap-fit ​​assembly (7) and the positioning groove.

3. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 2, characterized in that, The snap-fit ​​assembly (7) includes a spring (71) and a positioning ball (72). One end of the spring (71) is fixedly connected to the inner wall of the cavity, and the other end of the spring (71) is fixedly connected to one end of the positioning ball (72). The other end of the positioning ball (72) is adapted to the positioning groove.

4. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 2, characterized in that, The lower outer diameter of the push rod (6) is smaller than the outer diameter of the punch body (51), and the outer diameter of the punch body (51) is equal to the diameter of the through hole (4); the push rod (6) and the punch (5) are coaxially arranged; the height of the punch body (51) is greater than the height of the lower flange (3).

5. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 4, characterized in that, In step 1, the high temperature is 700–950℃; in step 4, the ultra-high strength steel is steel with a tensile strength of 1500–2000 MPa. Step 3 specifically includes: lowering the push rod (6) and the punch (5), using the tip (52) of the punch to pierce the body (1), and using the outer surface of the punch body (51) to stretch the pierced body (1) to form a through hole (4) and a lower flange (3) connected below the through hole (4).

6. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 5, characterized in that, In step 3, after the lower flange (3) is formed, the push rod (6) and punch (5) continue to descend until the top surface of the punch body (51) is below the first blocking member (8) in the travel channel of the lower punch (9), the push rod (6) stops descending, and the lower part of the push rod (6) is opposite to the through hole (4) and the lower flange (3). In step 5, the upper mold base (11) is raised, which drives the push rod (6) to rise. The first blocking member (8) applies a downward force to the top surface of the punch body (51) to compress the snap-fit ​​assembly (7), so that the punch body (51) is disengaged from the push rod (6).

7. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 6, characterized in that, The lower punch (9) has a mounting hole on its travel channel wall, and the first blocking member (8) is installed in the mounting hole. Each first blocking member (8) includes a first compression spring (81) and a first stop block (82). One end of the first compression spring (81) is connected to the wall of the mounting hole, and the other end of the first compression spring (81) is connected to one end of the first stop block (82). The other end of the first stop block (82) is located in the travel channel of the lower punch (9).

8. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 6, characterized in that, The upper mold base (11) is provided with a first feeding channel (111), and the upper die (10) is provided with a second feeding channel (101). The first feeding channel (111) and the second feeding channel (101) are connected, and the bottom end of the second feeding channel (101) is connected to the travel channel of the upper die (10). The upper die (10) has a wedge-shaped block (102) on its top surface. One end of the wedge-shaped block (102) has a first inclined surface (103), and the other end has a second inclined surface (104). The first inclined surface (103) and the second inclined surface (104) are arranged opposite to each other and have opposite inclination directions. The bottom surface of the upper mold base (11) is provided with a groove, which is connected to the first feeding channel (111); the groove is provided with a first limiting block (112), a second limiting block (113), a fixing block (114), a first elastic element (115) and a second elastic element (116), the fixing block (114) and the groove wall are fixedly connected, the first limiting block (112) is connected to the fixing block (114) through the first elastic element (115), the second limiting block (113) is connected to the fixing block (114) through the second elastic element (116), one end of the first limiting block (112) and one end of the second limiting block (113) can be located in the first feeding channel (111) of the upper mold base (11); one end face of the first limiting block (112) is adapted to the first inclined surface (103), and one end face of the second limiting block (113) is adapted to the second inclined surface (104); The upper die (10) has a second mounting hole on the wall of its travel channel. The second mounting hole is located below the second feeding channel (101). A second blocking member (12) is installed in each second mounting hole. Each second blocking member (12) includes a second compression spring (121) and a second stop (122). One end of the second compression spring (121) is connected to the wall of the second mounting hole, and the other end of the second compression spring (121) is connected to one end of the second stop (122). The other end of the second stop (122) is located in the travel channel of the upper die (10).

9. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 8, characterized in that, Step 1 further includes: under the action of the first elastic member (115), the end of the first limiting block (112) extends into the first feeding channel (111) to prevent the new punch (5) from falling; Step 3 further includes: one end face of the second limiting block (113) slides down along the second inclined plane (104), and the end of the second limiting block (113) facing the first feeding channel (111) moves towards the first feeding channel (111) to prevent the punch (5) located above it from falling; one end face of the first limiting block (112) slides down along the first inclined plane (103), and the end of the first limiting block (112) facing the first feeding channel (111) moves away from the first feeding channel (111) so that a punch (5) located between the first limiting block (112) and the second limiting block (113) falls from the first feeding channel (111) into the second feeding channel (101) of the upper die (10); Step 5 further includes: after the push rod (6) rises above the second feeding channel (101) of the upper die (10), the punch (5) in the second feeding channel (101) of the upper die (10) falls on the second blocking member (12).

10. The method for preparing ultra-high strength steel irregular parts with through holes according to claim 9, characterized in that, It also includes step 6: return to step 1, place the new plate on the lower punch (9), prepare the next irregular part, and in step 3, lower the upper die seat (11) and push rod (6) to install the punch (5) located on the second stop (12) at the bottom of the push rod (6).

Images