Method for using a quick clamping device of an upper die

Abstract

The application discloses a use method of an upper die fast clamping device, which comprises an upper die body, and the upper die body is prepared from the following components and in the following mass percentage: 0.17-0.52 parts of C, 0.17-0.31 parts of Si, 5.44-8.15 parts of Mn, 7.13-11.58 parts of Cr, 4.15-6.55 parts of Ni, ≤0.02 parts of P, ≤0.02 parts of S, 0.021-0.038 parts of Nb, 0.012-0.017 parts of Y, 0.07-0.23 parts of Ti, 0.08-0.14 parts of B, and the balance of Fe and impurities. The alloy material has improved toughness, forging process performance, wear resistance and grain densification distribution.

Description

Technical Field

[0001] This invention relates to the technical field of bending dies, and more particularly to a method of using a quick clamping device for the upper die. Background Technology

[0002] The existing production method uses a conventional bending machine. The upper die is mounted on the bending machine's slide, and the lower die is fixed to the bending machine's worktable. The upper and lower dies must be used as a set. The bending machine processes workpieces with different dimensions by changing dies of different shapes and specifications. Generally, once the shape and size of the die are determined, it can only process workpieces of one shape and size, and only one workpiece can be processed at a time. However, in actual work, many workpieces have only very small dimensional variations. Therefore, changing dies wastes production time and incurs significant costs for die production. Mass production is difficult, and precision control is challenging. The current method of processing one workpiece at a time is inefficient.

[0003] A search of CN114540699A, "A Method for Preparing a High-Performance Hot Work Die Steel," revealed that, based on the composition of H13 steel, the alloy composition was optimized using a low-C, low-Si, high-Mo composition with Ni microalloying. The chemical composition by mass percentage is as follows: C 0.34%–0.39%, Mn 0.35%–0.55%, Si 0.20%–0.35%, S ≤0.001%, P ≤0.008%, Cr 4.90%–5.10%, Mo 2.3%–2.6%, V… The steel composition is 0.50%–0.70%, Ni 0.25%–0.35%, Cu ≤0.08%, with the remainder being Fe. The residual gas content is H ≤1.5ppm, O ≤13ppm, and N ≤90ppm. Strict control is maintained throughout the production process, which includes: electric furnace smelting, ladle refining, vacuum refining, inert gas-protected electrode billet casting, constant-melting-rate electroslag remelting under protective atmosphere, high-temperature homogenization, multi-directional forging, post-forging pretreatment, and ultra-fine finishing. This invention also relates to a high-performance hot-work die steel. The annealed microstructure is uniform, with good spheroidized structure and fine, uniform grain distribution. The quenched and tempered microstructure is uniform, and the fine precipitates of Mo, Cr, and V carbides play a dispersive strengthening role during use. Simultaneously, an appropriate amount of Ni increases hardenability and refines the grains, thereby increasing the steel's toughness and fatigue resistance.

[0004] However, this overlooks the need for the module to be disassembled and reassembled according to changes in workpiece type and size. Furthermore, the aforementioned solution requires ensuring the module possesses a certain degree of wear resistance. Secondly, the process necessitates ultra-high temperature and prolonged high-temperature diffusion, which can easily oxidize readily oxidizable metal elements, generating oxides. These oxides contain numerous micropores and cracks, increasing the unreliability of the mold steel's performance, leading to a porous structure, and disrupting the continuity of the mold steel material's properties. This is particularly problematic during forging, as it can negatively impact the forging's process performance. Therefore, a rapid clamping device for the upper die capable of tens of thousands of forming cycles and its usage method are needed. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art, and therefore a quick clamping device for an upper mold and its usage method are proposed.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A quick clamping device for an upper mold includes an upper mold body, wherein the components and their mass percentages of the upper mold body are as follows: 0.17–0.52 parts of C, 0.17–0.31 parts of Si, 5.44–8.15 parts of Mn, 7.13–11.58 parts of Cr, 4.15–6.55 parts of Ni, ≤0.02 parts of P, ≤0.02 parts of S, 0.021–0.038 parts of Nb, 0.012–0.017 parts of Y, 0.07–0.23 parts of Ti, 0.08–0.14 parts of B, with the balance being Fe and impurities;

[0008] Where: Ti = 0.21(Nb+Y) + 0.34(C+S);

[0009] Where: Si = 0.21B + 0.015(Ni + Cr).

[0010] By adopting the above scheme: through reasonable quantification of Si, Si melts into the alloy matrix, exerting a solid solution strengthening effect; B is used to form hard metal compounds with Ni and / or Cr, resulting in a dispersed distribution in the alloy, thus playing a dispersion strengthening role and improving the hardness and wear resistance of the cemented carbide. The addition of Cr enhances the solid solution strengthening effect of Ni and improves its passivation ability. It can also form hard intermetallic compound phases with B and Si, playing a dispersion strengthening role and improving wear resistance. The addition of B and Si results in a wider overall solid-liquid phase temperature range for the upper mold steel, exhibiting excellent fluidity and wettability, leading to better processing performance. Lightweight, low-viscosity, and highly fluid salts form on the surface of the molten steel, floating to the surface and protecting the alloy from oxidation and porosity formation.

[0011] A reasonable amount of Ti (0.21(Nb+Y)+0.34(C+S)) during TiC formation allows Nb and Y to refine the primary TiC dendrites, increase the dendrite spacing, and increase the amount of elongated eutectic titanium carbide, resulting in ultrafine-grained TiC. The ultrafine-grained TiC, purified at the Nb and Y interface, increases interfacial wettability, allowing it to disperse uniformly in the alloy matrix with high density. When microcracks and residual stresses occur around the ultrafine-grained TiC, it can pin the cracks, dissipating fracture energy and thus improving the toughness of the alloy material and the machinability of forgings. Ti precipitates in steel, such as TiN, TiC, and Ti(C, N), can prevent austenite grain growth during heating and forging, while inhibiting the recovery and recrystallization of deformed austenite grains. Furthermore, the deformation bands and unrecovered substructure boundaries in austenite can further promote ferrite grain refinement, thus refining the microstructure and grain size, thereby improving the strength and impact toughness of the steel. Ti has a stronger affinity for S than Mn. As Ti content increases, the amount of Ti4C2S2 compounds in the steel gradually increases and replaces MnS inclusions. In other words, the addition of Ti removes S from MnS, forming a more stable Ti4C2S2 compound, which reduces MnS precipitation. The formation of elongated MnS inclusions in the steel is reduced due to the formation of Ti4C2S2. Spherical Ti4C2S2 compounds have high hardness and do not deform during high-temperature forging, thus improving the impact toughness of the steel.

[0012] Ti, Y, and Al will also form a binary or ternary eutectic liquid phase at a relatively low temperature during the cooling process of molten steel. The appearance of the liquid phase is conducive to the flow of grains in the initial formation of molten steel, thereby promoting the densification of grain distribution.

[0013] The above embodiments are improved as follows: the components and their mass percentages of the upper mold body are as follows: 0.19-0.50 parts of C, 0.21-0.28 parts of Si, 5.87-7.65 parts of Mn, 8.15-9.54 parts of Cr, 4.65-6.15 parts of Ni, ≤0.02 parts of P, ≤0.02 parts of S, 0.025-0.037 parts of Nb, 0.014-0.016 parts of Y, 0.09-0.20 parts of Ti, 0.08-0.14 parts of B, with the balance being Fe and impurities.

[0014] The above embodiments are improved as follows: the upper mold body further includes 0.013-0.023 parts of alloy steel modifier, which includes 32-45 parts of Al2O3, 26-31 parts of Al, 16-28 parts of CaF2, 5-15 parts of MgO, and 2-5 parts of LaNi5. By adding the above components during tapping, the top ladle slag can be deoxidized and modified, improving the desulfurization rate of the molten steel. Diffusion deoxidation is achieved by adding calcium carbide and aluminum particles, promoting rapid melting and uniform deoxidation of the top slag. Three-phase alloys with good thermal stability, such as Mg2NiLa, Mg2Ni, and MgNi2, are easily obtained. Given the extremely reactive chemical properties of Ti, which readily reacts with O and N in the molten steel, Ti microalloying is chosen before tapping the molten steel to stabilize the Ti yield.

[0015] The above embodiments are improved as follows: an upper mold base is provided, the upper mold base is provided with an installation slot for installing the upper mold body, an adjustment slot is provided on the side wall of the installation slot, a pressure structure for adjusting the state of the upper mold body is installed inside the adjustment slot, a limiting slot is provided on the upper mold base, and a limiting body adapted to the limiting slot is provided on the upper mold body.

[0016] In the above embodiments, the following improvements are made: the pressure-applying structure includes an adjustment member disposed inside the adjustment groove. The material of the adjustment member is the same as that of the upper mold body. The upper mold base is provided with a set screw, the end of which extends to the inner wall of the adjustment groove and abuts against the side of the adjustment member facing away from the upper mold body. The upper mold base is also provided with a countersunk hole, in which a spring is disposed and a bolt passing through the spring and connected to the adjustment member is disposed.

[0017] In the above embodiments, the following improvements are made: the upper mold body is provided with an inwardly recessed positioning area, and the adjusting member is provided with an outwardly protruding pushing area on the side opposite to the upper mold body that is adapted to the positioning area.

[0018] In the above embodiments, the following improvements are made: the cross-sections of the positioning area and the outward convex pushing area are arranged in an arc shape, a cone shape, or a rectangle.

[0019] A method for machining an upper die quick clamping device, the machining steps are as follows:

[0020] (1) Smelting

[0021] Using the material smelting method of claim 1, 0.013 to 0.023 parts of alloy steel modifier are added during steel tapping to obtain forging blanks of upper mold body and adjustment parts materials;

[0022] (2) Stress-relieving annealing treatment of forgings and forgings

[0023] The forging blank is heated to 1250-1450℃ for forging, and the final forging temperature is 950-970℃ to obtain the forging. The obtained forging is annealed in an annealing furnace at a temperature of 680-750℃ for 4-5 hours. It is then cooled to 200-300℃ in the annealing furnace, held at that temperature for 0.6-1.2 hours, and then air-cooled to room temperature.

[0024] (3) Preliminary machining and heat treatment of forgings

[0025] The forging is machined into the primary shape of the mold on a machine tool, with a 1.5mm allowance on each side. The machined mold is first heated to 530-550℃ and held for 3-4 hours, then heated to 750-800℃ and held for 1-2 hours, then heated to 940-960℃ and held for 30-45 minutes, then quenched, oil quenched, cooled and then subjected to deep cryogenic treatment at -220℃ to -230℃ for 1-2 hours. It is then restored to room temperature in air and tempered once at 130-140℃. After cooling to room temperature, it is placed for 1-1.5 hours and then tempered a second time at 150-170℃.

[0026] (4) Deep machining and machining center processing of the upper mold body and adjusting parts.

[0027] Remove the oxide layer from the surface of the mold after processing, and assemble it onto a grinding machine for grinding. Leave a margin of 0.7-1mm on each side. After letting it sit for at least one day, grind the other sides, except for the curved surface, to the required dimensions. Place the workpiece obtained from deep processing into a machining center and use a milling cutter to mill the curved surface of the mold, removing a margin of 0.7-1mm.

[0028] A method for using a quick clamping device for an upper mold is as follows: First, the upper mold body is installed horizontally along the limit body and limit groove. After installation, the adjustment part can be moved to the side closer to the upper mold body by adjusting the stroke of the set screw from a quarter turn to half a turn, thereby completing the clamping work of the upper mold body. During this process, the spring will be further compressed.

[0029] When it is necessary to remove the press-fit state for replacement, rotate the adjusting screw in the opposite direction to adjust the stroke to within a quarter to half a turn. During this process, the spring compression will gradually recover, causing the adjusting part to move away from the upper mold body. At this time, simply remove the upper mold body horizontally from the inside of the mounting slot, reinstall the new upper mold body, and readjust the adjusting screw to press the upper mold body with the adjusting part. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0031] Figure 2This is a cross-sectional view of the countersunk hole in the present invention;

[0032] Figure 3 This is a cross-sectional view of the set screw in this invention;

[0033] Figure 4 This is a side view of the upper mold base of the present invention;

[0034] Figure 5 This is a front view of the upper mold body of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the adjusting component of the present invention.

[0036] In the diagram: 10, upper mold base; 20, upper mold body; 30, mounting slot; 40, adjustment slot; 50, limiting slot; 60, limiting body; 70, ejector screw; 80, adjusting part; 90, spring; 100, countersunk hole; 110, positioning area; 120, outward convex pushing area; 130, bolt. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Example 1

[0040] A quick clamping device for an upper mold includes an upper mold body, the components and their mass percentages of which are: 0.17 parts C, 0.186 parts Si, 5.44 parts Mn, 7.13 parts Cr, 4.15 parts Ni, ≤0.02 parts P, ≤0.02 parts S, 0.021 parts Nb, 0.012 parts Y, 0.072 parts Ti, 0.08 parts B, with the balance being Fe and impurities;

[0041] Where: Ti=0.21*(Nb+Y)+0.34*(C+S)=0.21*(0.021+0.012)+0.34*(0.17+0.02)=0.072;

[0042] Where: Si = 0.21 * B + 0.015 * (Ni + Cr) = 0.21 * 0.08 + 0.015 *

[0043] (4.15+7.13)=0.186.

[0044] Example 2

[0045] A quick clamping device for an upper mold includes an upper mold body, the components and their mass percentages of which are: 0.19 parts C, 0.22 parts Si, 5.87 parts Mn, 8.15 parts Cr, 5.15 parts Ni, ≤0.02 parts P, ≤0.02 parts S, 0.028 parts Nb, 0.016 parts Y, 0.081 parts Ti, 0.08 parts B, with the balance being Fe and impurities;

[0046] Where: Ti=0.21*(Nb+Y)+0.34*(C+S)=0.21*(0.028+0.016)+0.34*(0.19+0.02)=0.081;

[0047] Where: Si = 0.21 * B + 0.015 * (Ni + Cr) = 0.21 * 0.08 + 0.015 *

[0048] (5.15+8.15)=0.22.

[0049] Example 3

[0050] A quick clamping device for an upper mold includes an upper mold body, the components and their mass percentages of which are: 0.32 parts C, 0.265 parts Si, 7.65 parts Mn, 9.54 parts Cr, 6.15 parts Ni, ≤0.02 parts P, ≤0.02 parts S, 0.037 parts Nb, 0.016 parts Y, 0.127 parts Ti, 0.14 parts B, with the balance being Fe and impurities;

[0051] Where: Ti=0.21*(Nb+Y)+0.34*(C+S)=0.21*(0.037+0.016)+0.34*(0.32+0.02)=0.127;

[0052] Where: Si = 0.21 * B + 0.015 * (Ni + Cr) = 0.21 * 0.14 + 0.015 *

[0053] (6.15+9.54)=0.265.

[0054] The molds produced using the same process in the three embodiments described above have hardnesses of HRC59, HRC61, and HRC58, respectively, and no cracks were found after magnetic particle testing. The molds remained functional after 18,700, 19,100, and 18,500 cycles of processing and use, respectively.

[0055] By adopting the above scheme: through reasonable quantification of Si, Si melts into the alloy matrix, exerting a solid solution strengthening effect; B is used to form hard metal compounds with Ni and / or Cr, resulting in a dispersed distribution in the alloy, thus playing a dispersion strengthening role and improving the hardness and wear resistance of the cemented carbide. The addition of Cr enhances the solid solution strengthening effect of Ni and improves its passivation ability. It can also form hard intermetallic compound phases with B and Si, playing a dispersion strengthening role and improving wear resistance. The addition of B and Si results in a wider overall solid-liquid phase temperature range for the upper mold steel, providing excellent fluidity and wettability, leading to better processing performance. Lightweight, low-viscosity, and highly fluid salts form on the surface of the molten steel, floating to the surface and protecting the weld alloy from oxidation and porosity.

[0056] A reasonable amount of Ti (0.21(Nb+Y)+0.34(C+S)) during TiC formation allows Nb and Y to refine the primary TiC dendrites, increase the dendrite spacing, and increase the amount of elongated eutectic titanium carbide, resulting in ultrafine-grained TiC. The ultrafine-grained TiC, purified at the Nb and Y interface, increases interfacial wettability, allowing it to disperse uniformly in the alloy matrix with high density. When microcracks and residual stresses occur around the ultrafine-grained TiC, it can pin the cracks, dissipate fracture energy, and thus improve the toughness of the alloy material. Ti precipitates in steel, such as TiN, TiC, and Ti(C, N), can prevent austenite grain growth during heating and forging, while inhibiting the recovery and recrystallization of deformed austenite grains. Furthermore, the deformation bands and unrecovered substructure boundaries in austenite can further promote ferrite grain refinement, thus refining the microstructure and grain size, thereby improving the strength and impact toughness of the steel. Ti has a stronger affinity for S than Mn. As Ti content increases, the amount of Ti4C2S2 compounds in the steel gradually increases and replaces MnS inclusions. In other words, the addition of Ti removes S from MnS, forming a more stable Ti4C2S2 compound, which reduces MnS precipitation. The formation of elongated MnS inclusions in the steel is reduced due to the formation of Ti4C2S2. Spherical Ti4C2S2 compounds have high hardness and do not deform during high-temperature forging, thus improving the impact toughness of the steel.

[0057] Ti, Y, and Al will also form a binary or ternary eutectic liquid phase at a relatively low temperature during the cooling process of molten steel. The appearance of the liquid phase is conducive to the flow of grains in the initial formation of molten steel, thereby promoting the densification of grain distribution.

[0058] In the above embodiments, the following improvements are made: the components of the upper mold body further include 0.015 parts of alloy steel modifier, which includes 45 parts of Al2O3, 26 parts of Al, 16 parts of CaF2, 10 parts of MgO and 3 parts of LaNi5.

[0059] In the above embodiments, the following improvements are made: the components of the upper mold body further include 0.018 parts of alloy steel modifier, which includes 32 parts of Al2O3, 31 parts of Al, 19 parts of CaF2, 13 parts of MgO and 5 parts of LaNi5.

[0060] By adding the above components during tapping, the top ladle slag can be deoxidized and modified, improving the desulfurization rate of the molten steel. Diffusion deoxidation is achieved by adding calcium carbide and aluminum particles, promoting rapid melting and uniform deoxidation of the top slag. Three-phase alloys with good thermal stability, such as Mg2NiLa, Mg2Ni, and MgNi2, are readily obtained. Given the extremely reactive chemical properties of Ti, which readily reacts with O and N in the molten steel, Ti microalloying is chosen before tapping to stabilize the Ti yield.

[0061] Example 4:

[0062] The following improvements are made based on the above embodiments: The upper mold base 10 and the upper mold body 20 are included. The upper mold base 10 is provided with a mounting slot 30 for mounting the upper mold body 20. An adjustment slot 40 is provided on the side wall of the mounting slot 30. A pressure-applying structure for adjusting the state of the upper mold body 20 is installed inside the adjustment slot 40. The pressure-applying structure includes an adjustment member 80 disposed inside the adjustment slot 40. A set screw 70 is provided on the upper mold base 10, and the end of the set screw 70 extends to the inner wall of the adjustment slot 40 and abuts against the side of the adjustment member 80 facing away from the upper mold body 20. Through the ultra-fine stroke adjustment of the set screw 70, the adjustment member 80 can be loosened or tightened on the handle of the upper mold body 20, allowing for subsequent disassembly and assembly. The operation is simple, the structure is relatively simple, practical, and reliable.

[0063] The upper mold base 10 is provided with a limiting groove 50, and the upper mold body 20 is provided with a limiting body 60 that is adapted to the limiting groove 50. Through the matching installation of the limiting body 60 and the limiting groove 50, the upper mold body 20 can be linearly fed and disassembled along the depth direction of the installation groove, without the need for continuous installation in the vertical direction. This solution can significantly reduce labor intensity.

[0064] The upper mold base 10 is also provided with a countersunk hole 100, in which a spring 90 is provided and a bolt 130 passes through the spring 90 and is connected to the adjusting member 80. The bolt 130 passes through the spring 90 and is connected to the adjusting member 80. When used with the set screw 70, the upper mold body 20 can be disassembled and assembled in a very fine distance.

[0065] In use, first, the upper mold body 20 is installed horizontally along the limit body 60 and the limit groove 50. After installation, the travel of the ejector screw 70 is controlled to about 5 microns (or adjusted within a quarter to half a turn) to move the adjusting part 80 closer to the upper mold body 20, thereby completing the clamping work of the upper mold body 20. During this process, the spring 90 will be further compressed. When it is necessary to release the clamping state for replacement, rotate the ejector screw 70 in the opposite direction to adjust the travel to about 5 microns (or adjusted within a quarter to half a turn). During this process, the compression of the spring 90 will gradually recover, causing the adjusting part 80 to move away from the upper mold body 20. At this time, it is only necessary to remove the upper mold body 20 horizontally from the inside of the mounting slot 30, reinstall the new upper mold body 20, and readjust the ejector screw 70 to clamp the upper mold body 20 with the adjusting part 80.

[0066] Based on the above embodiments, the following improvements are made: The upper mold body 20 is provided with an inwardly recessed positioning area 110, and the adjusting member 80 has an outwardly convex pushing area 120 adapted to the positioning area 110 on one side opposite to the upper mold body 20. The positioning area 110 and the outwardly convex pushing area 120 have a circular arc, conical, or rectangular cross-section. Preferably, the positioning area 110 and the outwardly convex pushing area 120 are conical in shape. Since the conical structure has an automatic correction effect, and the precision of the limiting groove 50 and the limiting body 60 cannot be precisely manufactured, if it were too precise, it would be difficult for the upper mold body 20 to enter the mounting groove. This design is based on the traditional method of attaching the mold handle by matching bolts and grooves. The precision of the groove cannot be guaranteed precisely; if it were too precise, the bolts would not be able to smoothly enter the groove to achieve the effect of inserting and installing the mold handle. This design ensures smooth entry into the corresponding position before pressing the mold body to achieve rough precision. High-precision installation is achieved through the corrective effect of the adjusting component 80 and the positioning area 110. High-precision installation guarantees the accuracy of the downward stroke of the upper mold body 20; higher downward stroke accuracy results in a more precise bending angle. Traditional quick-change upper mold devices cannot achieve high-precision control of the downward stroke. This embodiment easily solves this problem and features a simple structure and high practicality.

[0067] A method for machining an upper die quick clamping device, the machining steps are as follows:

[0068] (1) Smelting

[0069] Using the material smelting method of claim 1, 0.013 to 0.023 parts of alloy steel modifier are added during steel tapping to obtain forging blanks of upper mold body and adjustment parts materials;

[0070] (2) Stress-relieving annealing treatment of forgings and forgings

[0071] The forging blank is heated to 1250-1450℃ for forging, and the final forging temperature is 950-970℃ to obtain the forging. The obtained forging is annealed in an annealing furnace at a temperature of 680-750℃ for 4-5 hours. It is then cooled to 200-300℃ in the annealing furnace, held at that temperature for 0.6-1.2 hours, and then air-cooled to room temperature.

[0072] (3) Preliminary machining and heat treatment of forgings

[0073] The forging is machined into the primary shape of the mold on a machine tool, with a 1.5mm allowance on each side. The machined mold is first heated to 530-550℃ and held for 3-4 hours, then heated to 750-800℃ and held for 1-2 hours, then heated to 940-960℃ and held for 30-45 minutes, then quenched, oil quenched, cooled and then subjected to deep cryogenic treatment at -220℃ to -230℃ for 1-2 hours. It is then restored to room temperature in air and tempered once at 130-140℃. After cooling to room temperature, it is placed for 1-1.5 hours and then tempered a second time at 150-170℃.

[0074] (4) Deep machining and machining center processing of the upper mold body and adjusting parts.

[0075] Remove the oxide layer from the surface of the mold after processing, and assemble it onto a grinding machine for grinding. Leave a margin of 0.7-1mm on each side. After letting it sit for at least one day, grind the other sides, except for the curved surface, to the required dimensions. Place the workpiece obtained from deep processing into a machining center and use a milling cutter to mill the curved surface of the mold, removing a margin of 0.7-1mm.

[0076] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made to the technical solutions and inventive concepts of the present invention should all be covered within the scope of protection of the present invention.

Claims

1. A quick clamping device for an upper mold, comprising an upper mold body, wherein the components and their mass percentages of the upper mold body are: 0.17~0.52 parts of C, 0.17~0.31 parts of Si, 5.44~8.15 parts of Mn, 7.13~11.58 parts of Cr, 4.15~6.55 parts of Ni, ≤0.02 parts of P, ≤0.02 parts of S, 0.021~0.038 parts of Nb, 0.012~0.017 parts of Y, 0.07~0.23 parts of Ti, 0.08~0.14 parts of B, with the balance being Fe and impurities; wherein: Ti=0.21(Nb+Y)+0.34(C+S); Where: Si = 0.21B + 0.015(Ni + Cr).

2. A quick clamping device for an upper die according to claim 1, wherein The components and their mass percentages of the upper mold body are as follows: 0.19~0.50 parts of C, 0.21~0.28 parts of Si, 5.87~7.65 parts of Mn, 8.15~9.54 parts of Cr, 4.65~6.15 parts of Ni, ≤0.02 parts of P, ≤0.02 parts of S, 0.025~0.037 parts of Nb, 0.014~0.016 parts of Y, 0.09~0.20 parts of Ti, 0.08~0.14 parts of B, with the balance being Fe and impurities.

3. The upper mold quick clamping device according to claim 1, characterized in that, It also includes an upper mold base (10), on which an installation slot (30) for installing an upper mold body (20) is provided. An adjustment slot (40) is provided on the side wall of the installation slot (30). A pressure structure for adjusting the state of the upper mold body (20) is installed inside the adjustment slot (40). A limiting slot (50) is provided on the upper mold base (10), and a limiting body (60) adapted to the limiting slot (50) is provided on the upper mold body (20).

4. The upper mold quick clamping device according to claim 3, characterized in that, The pressure-applying structure includes an adjustment component (80) disposed inside the adjustment groove (40). The material of the adjustment component (80) is the same as that of the upper mold body. The upper mold base (10) is provided with a set screw (70), and the end of the set screw (70) extends to the inner wall of the adjustment groove (40) and abuts against the side of the adjustment component (80) facing away from the upper mold body (20). The upper mold base (10) is also provided with a countersunk hole (100). A spring (90) and a bolt (130) passing through the spring (90) and connected to the adjustment component (80) are disposed in the countersunk hole (100).

5. The quick clamping device of the upper die according to claim 3, wherein The upper mold body (20) is provided with an inwardly recessed positioning area (110), and the adjusting member (80) is provided with an outwardly protruding pushing area (120) on the side opposite to the upper mold body (20) that is adapted to the positioning area (110).

6. A quick clamping device for an upper die according to claim 5, wherein The cross-sections of the positioning area (110) and the convex pushing area (120) are arranged in a circular arc, conical or rectangular structure.

7. A method of machining a quick clamping device of an upper die, characterized in that, The processing steps are as follows: (1) Smelting The material composition and mass percentage of claim 1 are used for smelting, and 0.013 to 0.023 parts of alloy steel modifier are added during tapping to obtain forging blanks for the upper die body and adjusting parts, wherein the alloy steel modifier comprises 32 to 45 parts of... 26-31 parts of A1, 16-28 parts of 5-15 parts of MgO and 2-5 parts of ; (2) Stress-relieving annealing treatment of forgings and forgings The forging blank is heated to 1250~1450℃ for forging, and the final forging temperature is 950~970℃ to obtain the forging. The obtained forging is annealed in an annealing furnace at a temperature of 680~750℃ for 4~5 hours. It is then cooled to 200~300℃ in the annealing furnace, held for 0.6~1.2 hours, and then air-cooled to room temperature. (3) Preliminary machining and heat treatment of forgings The forging is machined into the primary shape of the mold on a machine tool, with a 1.5 mm allowance on each side. The machined mold is first heated to 530~550℃ and held for 3~4 h, then heated to 750~800℃ and held for 1~2 h, then heated to 940~960℃ and held for 30~45 min, then quenched, oil quenched, cooled and then subjected to deep cryogenic treatment at -220℃ to -230℃ for 1~2 h, then restored to room temperature in air, and then tempered once at 130~140℃. After cooling to room temperature, it is placed for 1~1.5 h and then tempered a second time at 150~170℃. (4) Deep machining and machining center processing of the upper mold body and adjustment parts After removing the oxide layer from the surface of the mold, it is mounted on a grinding machine for grinding. Each surface retains a margin of 0.7-1 mm. After resting for at least one day, the other surfaces, except for the curved surfaces, are ground again to the required dimensions. The workpiece obtained from the deep processing is placed in a machining center, and the curved surfaces of the mold are milled with a milling cutter to remove a margin of 0.7-1 mm.

8. A method of using the upper mold quick clamping device as described in claim 4, characterized in that, The steps are as follows: First, the upper mold body (20) is installed horizontally by means of the limiting body (60) and the limiting groove (50). After installation, the travel of the ejector screw (70) is adjusted from a quarter turn to half a turn. The adjusting part (80) can then be moved to the side closer to the upper mold body (20) to complete the tightening of the upper mold body (20). During this process, the spring (90) will be further compressed. When it is necessary to remove the press-fit state for replacement, rotate the adjusting screw (70) in the opposite direction to adjust the stroke to within a quarter turn to half a turn. During this process, the compression degree of the spring (90) will gradually recover, causing the adjusting part (80) to move away from the upper mold body (20). At this time, it is only necessary to remove the upper mold body (20) horizontally from the inside of the mounting slot (30), reinstall the new upper mold body (20), and readjust the adjusting screw (70) to press the upper mold body (20) through the adjusting part (80).

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