Mold and device for hot forming

Abstract

FIELD: hot forming mold.SUBSTANCE: hot forming mold comprises an upper mold part and a lower mold part. Between the upper part of the mold and the lower part of the mold, a profiled cavity is formed to accommodate the workpiece. Each of the upper part of the mold and the lower part of the mold has a cavity inside and contains hollow sections at given positions on one side of it. The hollow sections communicate with the cavity, allowing the injection of the working medium from the cavity onto the workpiece through the hollow sections. Several injection elements are installed in the cavity of the upper part of the mold and / or the cavity of the lower part of the mold. There are several working medium pipelines located in the cavity. The working medium pipelines are designed to supply the working medium to the injection elements, and the pressure in each of the working medium pipelines is adjustable.EFFECT: accuracy and efficiency of workpiece forming is increased.8 cl, 9 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

[0001] The present invention relates to the field of hot forming technology, and in particular to a hot forming mold and a hot forming device.

[0002] This application claims priority to Chinese Patent Application No. 202510123329.5, "HOT-FORMING MOLD AND APPARATUS", filed on January 24, 2025, in the National Intellectual Property Administration of China, the contents of which are incorporated herein by reference in their entirety.BACKGROUND OF THE INVENTION

[0003] Amid strict energy consumption controls in the automotive industry and the rapid development of new energy vehicles, safety and lightweight design requirements have become increasingly important. Hot-forming steel, due to its exceptionally high strength and relatively easy processing, is widely used in automotive structural components. The primary production process for hot-forming steel involves heating the steel sheet to a temperature above Ac3 to fully austenitize the microstructure, followed by rapid cooling. This process comprehensively increases the strength of the steel sheet, allowing yield strengths exceeding 1000 MPa. At the same time, there is currently a significant increase in demand for blanks with separate hot and cold forming zones, particularly for battery protection.The same component requires high structural strength and guaranteed welding characteristics.

[0004] In prior technology, the conventional quenching method involves providing channels for circulating water within the mold. This design utilizes indirect heat transfer for quenching. Quenching time and temperature are controlled by the water channels and the water flow rate and temperature in the mold, with thermal energy indirectly transferred to the quenched workpiece. However, this approach results in long quenching times and a large contact area with the workpiece being quenched. This can cause damage to the zinc coating layer on the workpiece surface, thereby affecting the performance of components with distinct hot and cold zones. For some hot-formed components with arbitrary angles and complex shapes, the manufacturing technology and placement of water channels present complex challenges, resulting in high processing costs. Furthermore, it is difficult to ensure uniform cooling.The mold has a large overall weight, and manufacturing costs are relatively high. However, prior technology uses a different approach to processing the workpiece, dividing it into hot and cold forming zones. However, this approach results in a complex mold design. Once the mold is created, adjusting the positions of the hot and cold forming zones is difficult, requiring different transition zones, creating design and development challenges. Furthermore, this approach requires large-volume production, high production costs, high maintenance and repair costs, and long delivery times, necessitating significant investment.

[0005] Therefore, how to improve the accuracy and efficiency of a hot mold is currently a technical problem that needs to be solved by specialists in this field of technology. ESSENCE OF THE INVENTION

[0006] The object of the present application is to provide a hot forming mold and a hot forming device that can effectively increase the cooling rate of a workpiece, achieve uniform and controllable temperature reduction of the workpiece, and have a wide range of applications.

[0007] In order to achieve the above-mentioned object, the following technical solutions are proposed according to the present application.

[0008] The hot mold includes: a mold upper part and a mold lower part, several injection parts and several working medium pipelines.

[0009] A profiled cavity is formed between the upper and lower mold sections to accommodate the workpiece. Each upper and lower mold section has a cavity inside and contains hollow sections at predetermined positions on one side, close to the profiled cavity. The hollow sections communicate with the cavity, allowing the injection of the working fluid from the cavity onto the workpiece through the hollow sections.

[0010] Multiple injection elements are installed in the upper mold cavity and / or the lower mold cavity.

[0011] Several working fluid pipelines are located within the cavity and are configured to supply the working fluid to the injection elements. The pressure in each working fluid pipeline is adjustable.

[0012] In another aspect, the pressures in at least two of the working fluid pipelines differ from each other. Alternatively, the temperatures of the working fluid in at least two of the working fluid pipelines differ from each other. Alternatively, the types of working fluid in at least two of the working fluid pipelines differ from each other.

[0013] In another aspect, the hot mold further includes an upper mold connecting plate and a lower mold connecting plate. The upper mold is mounted on the upper mold connecting plate and moves together with the upper mold connecting plate, and the lower mold is mounted on the lower mold connecting plate and moves together with the lower mold connecting plate.

[0014] In another aspect, the hollow portions are arranged at positions corresponding to solid areas of the workpiece, and the injection elements are installed at positions aligned with the hollow portions.

[0015] In another aspect, hollow sections are located between every two adjacent support contact sections. The support contact sections and hollow sections are arranged alternately. Each of the support contact sections has the shape of an elastic beam.

[0016] In another aspect, each of the support contact sections has a width varying from 3 mm to 50 mm, and each of the hollow sections has a width varying from 3 mm to 90 mm. Alternatively, the distance between the injection element and the workpiece varies from 120 mm to 660 mm. The injection element has a conical injection shape with an apex angle less than or equal to 125 degrees.

[0017] In another aspect, the support contact sections are made of stainless steel.

[0018] In another aspect, the hot forming mold further includes connecting members for installing working medium pipelines in the cavity, and the positions of the connecting members are adjustable to change the positions and angles of the working medium pipelines in the cavity.

[0019] In another aspect, the hot forming mold further includes multiple pressure devices and a controller.

[0020] The number of working medium pipelines is the same as the number of pressure devices, and the pressure devices are in one-to-one correspondence with the working medium pipelines.

[0021] The controller is connected to pressure devices. The controller is configured to obtain the positions of the soft and hard zones of workpiece 4 and determine the target pressure required for each of the working fluid pipelines based on the positions of the soft and hard zones of the workpiece. The controller is further configured to control the operation of the pressure device based on the target pressure.

[0022] Further provided is a hot forming apparatus according to the present application, including a hot forming mold described in any of the above aspects.

[0023] A hot mold according to the present application includes: an upper mold portion and a lower mold portion, multiple injection elements, and multiple working fluid pipelines. A profiled cavity for receiving a workpiece is formed between the upper mold portion and the lower mold portion. Each of the upper mold portion and the lower mold portion has a cavity inside, and each of the upper mold portion and the lower mold portion contains hollow sections at predetermined positions on one side thereof, near the profiled cavity. The hollow sections communicate with the cavity, allowing the working fluid to be injected from the cavity onto the workpiece through the hollow sections. Multiple injection elements are installed in the cavity of the upper mold portion and / or the lower mold portion. Multiple working fluid pipelines are located in the cavity and are configured to supply the working fluid to the injection elements. The pressure in each of the working fluid pipelines is adjustable.According to the hot forming mold 1 proposed in this application, a blank with a special shape and dimensions is formed by a profiled cavity between the upper part of the mold and the lower part of the mold. To meet the requirements for dividing the blank into soft and hard zones, each of the upper part of the mold and the lower part of the mold has a cavity inside in accordance with this application, and each of the upper part of the mold and the lower part of the mold contains hollow sections at predetermined positions on one side thereof, near the profiled cavity. The hollow sections must be located at predetermined positions on the upper part of the mold and the lower part of the mold, and said predetermined positions are determined based on the soft and hard zones of the blank. Specifically, the cooling rate corresponding to the hard zone of the blank is relatively high, and the hollow sections can be located at the corresponding positions.When the working fluid lines are located in a cavity with multiple injection elements, namely, nozzles positioned along the working fluid lines, the working fluid present in the working fluid lines is injected onto the workpiece by the injection elements, ensuring an increased cooling rate of the workpiece's hard zone. Conversely, for the soft zone of the workpiece, it is not necessary to place hollow sections, thereby reducing the workpiece's cooling rate. Specifically, in positions corresponding to the hard zones of the workpiece, the number and size of the hollow sections can be correspondingly increased to increase the contact area between the working fluid and the workpiece, thereby increasing the workpiece's cooling rate in this zone. Furthermore, the direction of the working fluid lines is adapted to the shape of the workpiece. The working fluid pressure in similar working fluid lines can be similar.For example, the pressure in the working fluid line corresponding to the hard zone of the workpiece may be higher than the pressure in the working fluid line corresponding to the soft zone of the workpiece. Alternatively, different temperature control for the soft and hard zones can be achieved by selecting different working fluid types or varying the working fluid temperature in different working fluid lines. This improves the accuracy and efficiency of workpiece forming, effectively eliminates quenching-induced workpiece deformation, and ensures excellent welding properties of the quenched workpiece with minimal surface oxidation.

[0024] In one embodiment, the hot forming mold further includes multiple pressure devices and a controller. The number of working medium pipelines coincides with the number of pressure devices, and the working medium pipelines are in a one-to-one correspondence with the pressure devices. The controller is connected to the pressure devices. The controller is configured to receive the positions of the soft and hard zones of the workpiece 4 and determine the target pressure required for each of the working medium pipelines, based on the positions of the soft and hard zones of the workpiece. The controller is further configured to control the operation of the pressure device based on the target pressure. When using the above configurations, the pressure device is controlled by the controller to adjust the pressure in the working medium pipeline, thereby ensuring the injection pressure in the injection elements on the working medium pipelines.Since the working medium pipelines are in one-to-one correspondence with the pressure devices, it is only necessary to obtain the placement positions of the soft and hard zones in the workpiece to accordingly adjust the pressure generated by the pressure device, which can achieve automatic control, while increasing the degree of automation, reducing operator intervention, maximizing the accuracy and efficiency of the hot forming process of the workpiece, and improving the product quality.

[0025] The hot-forming apparatus according to the present application includes a hot-forming mold. Since the hot-forming mold achieves the above-described technical effects, the hot-forming apparatus including the hot-forming mold should also achieve the corresponding ones. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly explain the technical solutions in the embodiments of the present application or in the prior art, the following briefly provides the drawings necessary for describing the embodiments or prior art. Obviously, the drawings in the following description only show some embodiments of the present application. Based on these drawings, those of ordinary skill in the art can derive other drawings without creative efforts.

[0027] Fig. 1 is a schematic diagram of the structure of a hot forming mold proposed in accordance with a specific embodiment of the present invention;

[0028] Fig. 2 is a schematic diagram of the structure showing the support contact portions and the hollow portions in the upper part of the mold and the lower part of the mold shown in Fig. 1;

[0029] Fig. 3 is a sectional view of the injection element and the working medium pipeline shown in Fig. 1;

[0030] Fig. 4 is a schematic diagram of the structure of the upper mold part and the lower mold part in the hot mold shown in Fig. 1, in a closed position;

[0031] Fig. 5 is one embodiment of the hot-cold forming zone division in the hot forming mold proposed in accordance with the present application;

[0032] Fig. 6 - another embodiment of the breakdown into hot-cold forming zones in a hot forming mold proposed in accordance with the present application;

[0033] Fig. 7 is a schematic diagram of the structure of a hot forming device proposed in accordance with a specific embodiment of the present application;

[0034] Fig. 8 is a schematic representation of the power transmission control mechanism of the hot forming device shown in Fig. 1;

[0035] Fig. 9 is an illustration of the structure of the water circulation system of the hot molding device shown in Fig. 1.

[0036] Reference numbers on drawings: DETAILED DESCRIPTION OF IMPLEMENTATION OPTIONS

[0037] The essence of the present application is to provide a hot forming mold and a hot forming device that can be adapted to various workpieces, with low production costs, a small installation area and a positive forming effect.

[0038] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the accompanying drawings. It is obvious that the described embodiments are only some, not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of legal protection of the present application.

[0039] Hot forming technology refers to the process of heating a steel sheet at high temperatures to completely austenitize its microstructure, then rapidly cooling it. This process comprehensively improves the strength of the steel sheet, allowing the steel to achieve yield strengths exceeding 1000 MPa. For example, when used in automobile body components, this material can reduce the weight of the car body and increase its strength, thereby achieving improved collision safety. Therefore, hot forming technology has been widely applied in the automotive industry.

[0040] In the hot forming process of prior technology, in-mold quenching is a critical step for achieving final performance, and mold shape is a key factor in controlling the cooling process. The preliminary design of a hot forming mold with indirect heat transfer involves calculating the energy released by the hot workpiece per unit time based on the thermal conductivity parameters of the water channel and the material, and determining the cooling rate to determine the required workpiece strength. However, in-mold quenching presents the following problems. First, it is difficult to accurately fit the heated steel workpiece into the mold cavities, increasing the difficulty of process control. Second, the heated steel workpiece usually has a non-planar shape. If structures such as corners exist, the cooling rate may be unstable, resulting in uneven internal hardness and uncontrolled strength of the workpiece.Third, the water channel in the mold does not have direct contact with the steel workpiece, resulting in a slower cooling rate and reduced cooling efficiency. Fourth, a quenching mold for hot forming is expensive and unaffordable for conventional companies, significantly limiting the widespread use of hot forming with indirect heat transfer.

[0041] In this embodiment, as shown in Fig. 1-6, the hot mold 1 includes an upper mold portion 11 and a lower mold portion 12, a plurality of injection members 14 and a plurality of working medium pipelines 15.

[0042] A profiled cavity for receiving the workpiece 4 is formed between the upper mold portion 11 and the lower mold portion 12. Each of the upper mold portion 11 and the lower mold portion 12 has a cavity inside, and each of the upper mold portion 11 and the lower mold portion 12 has hollow sections 13 at predetermined positions on one side thereof, close to the profiled cavity. The hollow sections 13 communicate with the cavity, allowing the injection of the working medium from the cavity onto the workpiece 4 through the hollow sections 13.

[0043] Several injection elements 14 are installed in the cavity of the upper part 11 of the mold and / or the cavity of the lower part 12 of the mold.

[0044] Multiple working medium pipelines 15 are located in the cavity and are configured to supply the working medium to the injection elements 14. The pressure in each of the working medium pipelines 15 is adjustable.

[0045] In particular, the hot forming mold 1 is applicable to most hot forming materials in the automobile industry, and the hot forming process uses high corrosion-resistant steel sheets with a single-layer metal coating or composite coatings such as hot-dip galvanizing, hot-dip galvanizing in the presence of nickel, hot-dip galvanizing to form an iron-zinc alloy, electrolytic galvanizing, electrolytic galvanizing in the presence of nickel, hot-dip galvanizing to form an aluminum-zinc alloy, and hot-dip galvanizing in the presence of silicon.The products manufactured using the mold have very high mechanical properties and corrosion resistance during use, and are applicable to components of conventional fuel vehicles and new energy vehicles, including front and rear bumpers, longitudinal support beams, upper side beams, door panel stiffeners, cross support beams, floor channels, suspension bracket, front / middle pillars, door sill protective structures, battery housing, etc.

[0046] Based on the hot forming mold 1 proposed in accordance with the present application, a blank 4 with a special shape and size is formed by a profiled cavity between the upper mold portion 11 and the lower mold portion 12. In order to meet the requirements of dividing the blank 4 into soft and hard zones, in the present application, each of the upper mold portion 11 and the lower mold portion 12 has a cavity inside, and each of the upper mold portion 11 and the lower mold portion 12 has hollow portions 13 at predetermined positions on one side thereof, close to the profiled cavity. The hollow portions 13 must be located at predetermined positions on the upper mold portion 11 and the lower mold portion 12, and said predetermined positions are set based on the soft and hard zones of the blank 4. Namely, the cooling rate corresponding to the hard zone of the blank 4 is relatively high, and the hollow portions 13 can be arranged at the corresponding positions.When the working medium pipelines 15 are arranged in a cavity with several injection elements 14, namely nozzles arranged on the working medium pipelines 15, the working medium present in the working medium pipelines 15 is injected onto the workpiece 4 by the injection elements 14, providing an increased cooling rate for the hard zone of the workpiece 4. On the contrary, for the soft zone of the workpiece 4 it is not necessary to arrange the hollow sections 13, which as a result reduce the cooling rate of the workpiece 4. More specifically, in the positions corresponding to the hard zones of the workpiece 4, the number and dimensions of the hollow sections 13 can be adjusted, if necessary, to change the contact area between the working medium and the workpiece 4, thereby increasing the cooling rate of the workpiece 4 in the said position. In addition, the direction of arrangement of the working medium pipelines 15 is adapted to the shape of the workpiece 4. The pressure of the working medium in a similar working medium pipeline 15 can be similar.For example, the pressure in the working medium pipeline 15 corresponding to the hard zone of the workpiece 4 may be higher than the pressure in the working medium pipeline 15 corresponding to the soft zone of the workpiece 4. Alternatively, different temperature control for the soft and hard zones can be achieved by selecting different types of working medium or changing the temperature of the working medium in different working medium pipelines 15, which improves the forming accuracy and efficiency of the workpiece 4, effectively eliminates the deformation of the workpiece 4 caused by quenching and ensures high welding characteristics of the quenched workpiece and minimal oxidation of the surface of the workpiece 4. The hot forming mold can meet the requirements for hot forming processing of the soft and hard zones or the maximum hardness zones of the workpiece 4.In addition, the hot forming mold provides the ability to achieve precise forming, very high welding characteristics, effective elimination of quenching-induced deformation, and minimal oxidation of the workpiece surface 4.

[0047] In some embodiments, the pressures in at least two of the working fluid lines 15 differ from each other. Higher pressures result in an increased cooling rate of the workpiece 4. Different pressures are set for the soft and hard zones to meet different requirements. Of course, the pressures in individual working fluid lines 15 may be the same.

[0048] In some embodiments, the temperatures of the working medium in at least two of the working medium lines 15 differ from each other. A lower temperature results in a reduced cooling rate of the workpiece 4. Different requirements can be met by setting different temperatures for the soft and hard zones. Of course, the temperatures in individual working medium lines 15 can also be the same.

[0049] In some embodiments, the types of working fluid in at least two of the working fluid lines 15 differ from each other. For example, liquid water, compressed air, or a gas-liquid mixture can be selected. To meet different cooling requirements, different types of working fluids can be supplied to the working fluid lines 15. Of course, the types of working fluid in individual working fluid lines 15 can be the same.

[0050] Specifically, when using the above-described configurations, cold and hot forming zones can be obtained by setting different pressures in individual working medium pipelines 15, or by adding a heating rod to adjust the temperatures of the working medium in individual working medium pipelines 15, or by supplying different working medium to the working medium pipelines 15 to control the division into cold-hot forming zones.

[0051] In some embodiments, the hot mold 1 further includes a connecting plate 16 of the upper part of the mold and a connecting plate 17 of the lower part of the mold. The upper part 11 of the mold is mounted on the connecting plate 16 of the upper part of the mold and moves together with the connecting plate 16 of the upper part of the mold, and the lower part 12 of the mold is mounted on the connecting plate 17 of the lower part of the mold and moves together with the connecting plate 17 of the lower part of the mold. In addition, the connecting plate 16 of the upper part of the mold and the connecting plate 17 of the lower part of the mold are mounted, respectively, on the upper slider 22 and the lower slider 23 of the hot molding device 2.When the upper slider 22 and the lower slider 23 move closer to or further from each other, the connecting plate 16 of the upper part of the mold and the connecting plate 17 of the lower part of the mold respectively converge closer to or diverge from each other, thereby ensuring the closing and opening of the upper part 11 of the mold and the lower part 12 of the mold.

[0052] In some embodiments, the hollow sections 13 are located in positions corresponding to the hard zones of the workpiece 4. The working medium in the hollow sections 13 is in direct contact with the workpiece 4, and therefore the workpiece 4 can be quickly cooled by the working medium in the hollow sections 13, thereby increasing the hardness of the workpiece 4 in said positions. In addition, in order to enhance the effect of the injection element 14 on the workpiece 4, the injection elements 14 are installed in positions aligned with the hollow sections 13. Of course, the positions of the injection elements 14 can be adjusted if necessary or taking into account the size and shape of the cavity. The cooling rate of the workpiece 4 is mainly controlled by the positions and sizes of the hollow sections 13, as well as the pressure, temperature and type of the working medium.

[0053] In some embodiments, the hollow sections 13 are located between adjacent support contact sections 110, wherein the support contact sections 110 and the hollow sections 13 are arranged alternately. Such an alternate arrangement of the support contact sections 110 and the hollow sections 13 can facilitate processing and optimize the positional constraint of the workpiece 4. At the same time, the arrangement density of the hollow sections 13 can be appropriately increased in the position corresponding to the solid zone of the workpiece 4.

[0054] Each support contact portion 110 has the shape of an elastic bar. Specifically, by adopting a bar-shaped structure for the support contact portion 110 and leaving a certain amount of elastic deflection for the support contact portion 110, it is possible to combine the workpiece 4 with a complete hardening process by heating it to a temperature above Ac3 and cooling it to 180°C. Due to the significant deformation of the workpiece 4 during the complete hardening process, the bar-shaped structure effectively limits the change in the shape of the workpiece 4, facilitating the hot forming of the workpiece 4 and improving the forming accuracy of the workpiece 4.

[0055] In some embodiments, each support contact portion 110 has a width ranging from 3 mm to 50 mm. The width of the support contact portion 110 should not be too small to provide sufficient support for the workpiece 4, and should not be too large, since this will weaken the cooling effect. Each hollow portion 13 has a width ranging from 3 mm to 90 mm. The width of the hollow portion 13 should not be too small to ensure effective cooling, and should not be too large, since this will affect the width of the support contact portion 110, and therefore will not provide sufficient support for the workpiece 4. Alternatively or additionally, the distance between the injection element 14 and the workpiece 4 is in the range of 120 mm to 660 mm.The distance between the injection element 14 and the workpiece 4 refers to the gap between the injection element 14 and the workpiece 4 after the upper mold portion 11 and the lower mold portion 12 are closed. The distance between the injection element 14 and the workpiece 4 can affect the injection speed and the flow rate of the working medium and can be adjusted as necessary. The injection element 14 has a conical injection shape with an apex angle less than or equal to 125 degrees. Using this design, the working medium can be optimally injected onto the workpiece 4, thereby increasing the cooling rate of the workpiece 4. In addition, the transition zone between the soft and hard zones has a width ranging from 3 mm to 60 mm, ensuring wide applicability.

[0056] In some embodiments, the support contact section 110 is made of stainless steel to extend its service life. In particular, to improve the wear resistance of the support contact section 110, the thickness of the support contact section 110 can be increased, or a wear-resistant coating can be applied to the surface of the support contact section 110.

[0057] In some embodiments, the hot mold 1 further includes connecting elements for installing the working medium pipelines 15 in the cavity, and the positions of the connecting elements are adjustable to change the positions and angles of the working medium pipelines 15 in the cavity. In particular, each connecting element includes an upper connecting element 18 and a lower connecting element 19, each of which is two. The working medium pipeline 15 in the upper part 11 of the mold is fixed between two upper connecting elements 18, and the working medium pipeline 15 in the lower part 12 of the mold is fixed between two lower connecting elements 19.The installation height of the pipeline 15 of the working medium in the upper part 11 of the mold can be adjusted by means of the upper connecting elements 18, and the installation height of the pipeline 15 of the working medium in the lower part 12 of the mold can be adjusted by means of the lower connecting elements, thereby changing the distance between the injection element 14 and the workpiece 4.

[0058] In some embodiments, the hot forming mold 1 further includes multiple pressure devices and a controller.

[0059] The number of working medium pipelines 15 is the same as the number of pressure devices, and the working medium pipelines 15 are in one-to-one correspondence with the pressure devices.

[0060] The controller is connected to pressure devices. The controller is configured to obtain the positions of the soft and hard zones of the workpiece 4 and determine the target pressure required for each of the working medium pipelines 15 based on the positions of the soft and hard zones of the workpiece 4. The controller is further configured to control the operation of the pressure devices based on the target pressures.

[0061] In the above-described structure, the controller controls the pressure devices to adjust the pressure in the working medium lines 15 to meet the injection pressure requirements of the injection element 14 in each of the working medium lines 15. Since the working medium lines 15 are in a one-to-one correspondence with the pressure devices, the pressure generated by the pressure devices can be adjusted accordingly simply by obtaining the placement positions of the soft and hard zones in the workpiece 4, which can achieve automatic control, thereby increasing the degree of automation, reducing operator intervention, maximizing the accuracy and efficiency of the hot forming process of the workpiece 4, and improving product quality.

[0062] In particular, in the embodiment, the hot mold 1 is a hot mold 1 with soft and hard zones or maximum hard zones. During the hot molding process, the hollow sections 13 come into direct contact with the blank 4 or the hot-formed component, which has been heated to a temperature above Ac3. The working medium pipelines 15 are configured to accumulate and supply a cooling working medium, and the working medium pipelines 15 are connected to the upper part 11 of the mold or the lower part 12 of the mold by means of connecting elements at both their ends. There are several injection elements 14, which are mechanically and hermetically connected to the connecting holes on the working medium pipeline 15. The connecting support plate of the upper part of the mold and the connecting support plate of the lower part of the mold are connected, respectively, to the upper part 11 of the mold or the lower part 12 of the mold by means of mechanical connecting elements.The upper surface of the connecting support plate of the upper part of the mold and the lower surface of the connecting support plate of the lower part of the mold are connected, respectively, to the upper slider 22 and the lower slider 23 of the press. When the pressure in the pipeline 15 of the working medium reaches the threshold pressure range of 0.3-3 MPa, the working medium is supplied to several injection elements 14 through the pipelines 15 of the working medium, and the injection elements 14 on the pipelines 15 of the working medium inject the cooling working medium under different pressures for quenching. The excess injected cooling working medium is returned to the repeated cycle for secondary use through a special pipeline. Each pipeline 15 of the working medium is equipped with a pressure device, and the pressure in the pipeline 15 of the working medium is in the range from 0.3 MPa to 3 MPa. The pressure device performs the functions of automatic start-stop and provides an adjustable and controlled pressure.Several injection elements 14 are arranged taking into account the shape of the workpiece 4, each of the atomized particles from each injection element 14 has a size in the range from 90 micrometers to 400 micrometers, and the flow rate is from 80 ml per minute to 1000 ml per minute. The installation distance between the injection elements 14 on different pipelines 15 of the working medium and the workpiece 4 varies, and the distance from the initial injection point to the workpiece 4 is in the range from 120 mm to 660 mm. Each of the injection elements 14 provides an injection angle within 135 degrees, and each of the injection elements 14 injects the working medium in the form of a solid cone or a hollow cone. The support contact section 110 can be made of steel with a surface coating or made entirely of stainless steel.The injection elements 14 may be used in a top-bottom arrangement, i.e., the working medium pipelines 15 and the injection elements 14 are located both in the upper mold portion 11 and in the lower mold portion 12. Alternatively, the injection elements 14 may be located only in the upper mold portion 11 or only in the lower mold portion 12.

[0063] Specifically, the hot forming process includes the following steps.

[0064] At step S1, a blank is punched from a galvanized steel sheet. The steel is processed into coils or sheets and cut to the required dimensions. Alternatively, a blank can be punched from a steel sheet with an aluminum-silicon coating. Of course, pure thick sheet steel without any coating can also be used.

[0065] In step S2, cold forming is performed. A mold is used to perform cold forming to form steel blank 4.

[0066] In step S3, heating is performed. The steel workpiece 4 is heated to a temperature above Ac3. If there is no coating on the surface of the steel in step S1, then in step S3, the steel workpiece 4 is first heated to a temperature above 700°C at a rate of 12~28°C / s, then heated to a temperature above Ac3 at a rate of 1~5°C / s and held at this temperature for 28 s to 55 s. If the steel in step S1 has been subjected to surface treatment by any method such as galvanizing, aluminizing, Al-Si coating, or high-temperature oxidation, then in step S3, the steel workpiece 4 is heated at a rate of 8~15°C / s when the temperature is below 500°C. After this, the steel workpiece 4 is heated to a temperature of 560°C to 980°C at a rate of 15~30°C / s, and then heated to a temperature above Ac3 at a rate of 1~5°C / s and held at this temperature for 28 s to 55 s.

[0067] At step S4, the blank 4 is transferred to the hot forming press.

[0068] In step S5, the upper mold assembly 11 is moved in the X direction to close the mold, gradually coming into contact with the blank 4 and being compressed with the lower mold assembly 12.

[0069] In step S6, the pressure device is turned on to supply water to the working medium pipeline 15, and, at a certain pressure, the plurality of injection elements 14 start to inject the working medium onto the workpiece 4 for quenching during hot forming.

[0070] In step S7, the pressure device is turned off after the quenching process is completed.

[0071] In step S8, the mold upper portion assembly 11 is moved in a direction opposite to the X direction until the mold is completely opened.

[0072] In the above process, the upper part 11 of the mold moves downward in the X direction and, together with the lower part 12 of the mold, compresses the blank 4 to ensure the compression and forming of the hot-formed blank. The pressure device is turned on after the compression operation is completed, allowing several injection elements 14 to perform quenching and injection. Moreover, the mold is opened before the pressure device is turned off. This process can improve the controllability of steel quenching and simplify the production stages of the hot-forming process. In the first stage, through the injection and injection of a fluid, the fluid cooling working medium comes into direct contact with the surface of the steel blank 4, which has been heated to a temperature higher than Ac3, as a result of which the blank 4 is cooled to a temperature of 250°C to 450°C within a control time of 2 s to 10 s.In the second stage, the cooling working medium comes into direct contact with the surface of the steel blank 4, by supplying it under pressure and injecting the fluid medium, as a result of which the blank 4 is cooled to a temperature below 100°C during a control time ranging from 2 s to 10 s, thereby achieving the working characteristics of the blank 4. Of course, it is permissible for the surface of the steel blank 4 to be continuously cooled during one stage, for example, to a temperature below 100°C during a control time ranging from 2 s to 30 s. Such a process simplifies the structural design of the mold, increases the cooling rate of the steel blank 4 and ensures a more uniform and controlled cooling of the steel blank 4.This approach effectively addresses the problems of prior art technology, in which the division of cold-hot forming zones is achieved primarily by embedding different functional modules into the zoning mold, which complicates zoning in a relatively small area. The mold design with both cold and hot forming zones is relatively complex, and the combined presence of water channels and a heating element in a single mold creates potential safety hazards. In this application, the layout of the cold-hot forming zones and the modification of the zoning are simple, enabling modular design and mold weight reduction. The degree of adaptability and reconfiguration is high in terms of changes in the product design and the positions of the cold and hot forming zones.

[0073] In addition to the hot forming mold 1, a hot forming device 2 according to the present application is further provided, including the above-described hot forming mold 1.

[0074] In this embodiment, as shown in Fig. 7-9, the hot forming device 2 includes:

[0075] frame 21 of the device, upper slider 22 and lower slider 23, transfer unit 24 and controller.

[0076] Both the upper slider 22 and the lower slider 23 are mounted on the frame 21 of the device. The upper slider 22 is configured to drive the upper part 11 of the mold, and the lower slider 23 is configured to drive the lower part 12 of the mold.

[0077] A transmission unit 24 is installed on the frame 21 of the device. The transmission unit 24 includes: a drive component 24-1, a power conversion component 24-2 connected to the drive component 24-1, a torque transmission mechanism 24-3 connected to the power conversion component 24-2, and a feedback signal encoder 24-4 for obtaining the rotation angle of the torque transmission mechanism 24-3. Each of the power conversion component 24-2 and the torque transmission mechanism 24-3 has the shape of a gear. The torque transmission mechanism 24-3 is configured to drive the upper slider 22 in a direction closer to the lower slider 23 or further from it.

[0078] Both the driving component 24-1 and the feedback signal encoder 24-4 are connected to the controller, and the controller is configured to control the operation of the driving component 24-1 based on the rotation angle of the torque transmission mechanism 24-3 received by the feedback signal encoder 24-4.

[0079] Specifically, the rotation of the torque transmission mechanism 24-3 causes the upper slider 22 to move up and down, thereby ensuring the mold opening and closing operations of the entire device. The drive component 24-1 provides power support for pressing down, positioning, and lifting the upper slider 22. The drive component 24-1 can adjust the torque of the device based on the actual requirements of the device and then control the pressure applied by the device, with its force controlled and adjustable in the range of 1 ton to 600 tons. The drive component 24-1 can interact with the torque transmission mechanism 24-3 and provide a feedback signal to the torque transmission mechanism 24-3, forming a closed-loop control of the power transmission position to accurately control the positioning, and the repeatable positioning accuracy can reach +0.03 mm.When replacing the power conversion component 24-2 and the torque transmission mechanism 24-3 with different technical characteristics, the transmission ratio between the power conversion component 24-2 and the torque transmission mechanism 24-3 can be in the range of 1-100 to meet various usage requirements.

[0080] In the hot molding device 2, a gear transmission is used between the drive component 24-1, the power conversion component 24-2 and the torque transmission mechanism 24-3 to improve the movement accuracy of the upper slider 22, thereby improving the positioning accuracy of the upper mold portion 11 relative to the lower mold portion 12 during mold closing and further improving the processing accuracy of the workpiece 4. In addition, when the encoder 24-4 provides a feedback signal, the rotation angle of the torque transmission mechanism 24-3 is obtained by the encoder 24-4 of the feedback signal and transmitted back to the controller, and therefore the position of the slider can be transmitted back more accurately, which improves the positioning accuracy of the upper mold portion 11 relative to the lower mold portion 12 during mold closing and further improves the processing accuracy of the workpiece 4.

[0081] In some embodiments, the transmission unit 24 further includes a braking transmission component 24-5, which is configured to transmit power from the drive component 24-1 to the power conversion component 24-2. The braking transmission component 24-5 is connected between the drive component 24-1 and the power conversion component 24-2, and the braking transmission component 24-5 is connected to the controller. The controller is further configured to control the braking transmission component to stop as soon as the upper slider 22 is moved to a predetermined position. The braking transmission component 24-5 is similarly a gear transmission. The braking transmission component 24-5 is connected to the drive component 24-1 and is in engagement with the power conversion component 24-2 to transmit power from the drive component 24-1 to the power conversion component 24-2.The brake transmission component 24-5 can serve as a protection for the drive component 24-1, improve the positioning accuracy of the device, and ensure the positioning stability of the entire device.

[0082] In some embodiments, the transmission unit 24 further includes a rotary coupling component 24-6. One end of the rotary coupling component 24-6 is pivotally connected to the torque transmission mechanism 24-3, and the other end of the rotary coupling component 24-6 is pivotally connected to the upper slider 22. The torque transmission mechanism 24-3 drives the upper slider 22 in an up and down motion by means of the rotary coupling component 24-6, ensuring smooth and stable movement of the upper slider 22 in the vertical direction. The transmission unit 24 serves both as a source of force for the device and as a mechanical section for closed-loop control of the position of the device as a whole.

[0083] In some embodiments, there are at least two power converter components 24-2, at least two torque transmission mechanisms 24-3, and at least two rotary coupling components 24-6, symmetrically located, respectively, on the left side and right side of the brake transmission component 24-5. At least one of the rotary coupling components 24-6 is connected to each of the left side and right side of the upper slider 22, respectively. Thus, the left side and right side of the upper slider 22 can move synchronously, which results in improved positioning accuracy.

[0084] In some embodiments, the transfer unit 24 further includes a balancing pneumatic cylinder 24-7, which is configured to balance the physical weights of the upper slider 22 and the upper part 11 of the mold to reduce the torque and power from the drive component 24-1, thereby saving energy. The speed of opening and closing the mold of the device can reach a maximum of 2 m / m. The speed of opening and closing the mold of the device can also be in the range of 0.1 m / s to 2 m / s, with the possibility of adjusting this speed. The upper part 11 of the mold can have a stroke in the range of 0 m to 4 m, and the mold opening distance can be in the range of 0 m to 3 m, which allows for adjustment. Due to the high control precision of the device, the working surface of the lower module can be made in the size of 3500 mm x 5000 mm, which meets the requirements of low-force processing for the device and large-sized workpiece 4.

[0085] In some embodiments, the working surface is located on the upper portion of the lower slider 23, and the working surface is provided with a plurality of positioning grooves for positioning the lower part 12 of the mold and a plurality of fixing grooves for fixing the lower part 12 of the mold. The positioning grooves and the fixing grooves are respectively arranged in a specific order. Specifically, the working surface of the lower slider 23 is provided with cross-shaped positioning grooves, which are designed for mold replacement and precise positioning during mold installation. That is, when installing the same model of hot molding mold 1, the installation blocks can be installed in the positioning grooves without re-positioning, which improves the efficiency of mold installation.In addition, the fixing grooves are T-shaped grooves, and the lower part 12 of the mold from the hot molding mold 1 is attached and fixed to the T-shaped grooves, ensuring stable positioning of the lower part 12 of the mold.

[0086] In some embodiments, the hot molding device 2 further includes a mounting adapter 25 for supplying water to the upper portion of the mold.

[0087] The mounting adapter 25 for supplying water to the upper part of the mold is configured to be connected to an external pipeline. The mounting adapter 25 for supplying water to the upper part of the mold is mounted on the frame 21 of the device, and the upper part 11 of the mold has a quick-release connector that is removably connected to the mounting adapter 25 for supplying water to the upper part of the mold. The quick-release connector communicates with the pipeline 15 of the working medium. In particular, the mounting adapter 25 for supplying water to the upper part of the mold can be directly included in the frame 21 of the device or connected to the frame 21 of the device by means of bolts. The external pipeline supplies the cooling working medium to the mounting adapter 25 for supplying water to the upper part of the mold through a flexible or rigid connecting element. The upper part 11 of the mold from the mold 1 for hot molding has a quick-release connector, and a flexible or rigid pipe for supplying the cooling working medium can be connected between them.Of course, the hot-forming device 2 may further include a mounting adapter for supplying water to the lower portion of the mold, configured to be connected to an external pipeline. The mounting adapter for supplying water to the lower portion of the mold is mounted on the device frame 21, and the lower portion 12 of the mold has a quick-release connector that is removably connected to the mounting adapter for supplying water to the lower portion of the mold. The quick-release connector communicates with the working fluid pipeline 15. In particular, the mounting adapter for supplying water to the lower portion of the mold may be directly included in the device frame 21 or attached to the device frame 21 by means of bolts. The external pipeline supplies the cooling working fluid to the mounting adapter for supplying water to the lower portion of the mold via a flexible or rigid connecting element.The lower mold section 12 of the hot-forming mold 1 has a quick-change connector, and a flexible or rigid tube for supplying a cooling working medium can be connected between them. Furthermore, the mounting adapter 25 for supplying water to the upper mold section and the mounting adapter for supplying water to the lower mold section are compatible with both high and low pressures, specifically in the range of 0.1 MPa to 30 MPa, to meet the requirements of various operating modes.

[0088] In some embodiments, the hot molding device 2 further includes an upper water channel nozzle 26 and a lower water channel nozzle 27. The upper water channel nozzle 26 is fixed to the upper slider 22, and the lower water channel nozzle 27 is fixed to the lower slider 23. The upper water channel nozzle 26 communicates with a quick-release connector and is connected to the mounting adapter 25 for supplying water to the upper part of the mold via a flexible or rigid pipe in such a way that the working medium is supplied to the upper part 11 of the mold, thereby facilitating the hardening process.

[0089] In some embodiments, the hot forming device 2 further includes an exhaust gas collection component 28 and a water circulation system 29.

[0090] The exhaust gas collecting component 28 is configured to collect exhaust gas during the quenching process and is installed on the top of the frame 21 of the device.

[0091] The water circulation system 29 is configured to collect the working medium and return it to a repeated cycle. The water circulation system 29 includes a collection chamber 29-1 for circulating water, a water return component 29-2, a water storage tank 29-3, a water supply component 29-4, a secondary cleaning filter 29-5 and / or a tertiary cleaning filter 29-6 and a high-pressure water pump 29-7. The collection chamber 29-1 for circulating water is configured to accumulate the cooling water returned from the hot mold 1 and to perform preliminary filtration of the cooling water. The water return component 29-2 is configured to take the cooling water from the hot mold 1 and supply the cooling water to the collection chamber 29-1 for circulating water, and the water return component 29-2 is connected to the collection chamber 29-1 for circulating water.The water storage tank 29-3 is configured to store the circulating water pre-filtered in the collecting chamber 29-1 for circulating water, and the water storage tank 29-3 can stabilize the water pressure and the water volume so that the water supply process of the quenching device is more stable and smooth. The water supply component 29-4 is configured to receive the circulating water pre-filtered in the collecting chamber 29-1 for circulating water and supply it to the water storage tank 29-3, and the water supply pipe is connected to the water storage tank 29-3 for supplying cooling water to the mold 1 for hot molding. A secondary cleaning filter 29-5 and / or a tertiary cleaning filter 29-6 are installed on the water supply pipe for secondary and / or tertiary filtration of the cooling water in the water supply pipe.Secondary filter 29-5 filters water in the water supply pipe, and tertiary filter 29-6 filters water further in the water supply pipe, ensuring the purity of the water used in the device. High-pressure water pump 29-7 is mounted on water supply pipe 29-8 and is capable of regulating water pressure in the water supply pipe, with a pressure adjustment range of 0-3 MPa.

[0092] In some embodiments, the hot molding device 2 further includes a guide mechanism 210 installed in the device frame 21, and the upper slider 22 is slidably connected to the guide mechanism 210. The lower slider 23 is slidably mounted in the device frame 21, and the lower slider 23 can be slid from the inside to the outside of the device frame 21, which facilitates the mold change. In the above-described structure, the guide mechanism 210 can be a guide rail, for example, a steel guide rail. By arranging the guide mechanism 210, the smoothness of the vertical movement of the upper slider 22 can be improved, thereby increasing the positional accuracy of the upper slider 22 during movement and further improving the positioning accuracy of the upper part 11 of the mold. In addition, the lower slider 23 can be slid from the inside to the outside of the device frame 21.That is, the lower slider 23 serves as a movable work table, which can be pulled out from the frame 21 of the device in the left and right direction to change the shape, thus increasing the convenience and efficiency of changing the shape.

[0093] In some embodiments, a device base is further located at the bottom of the device frame 21, and the device frame 21 is mounted on the device base, which can provide more reliable support for the device frame 21 and ensure the stability of the device frame 21, thereby ensuring smooth movements of the upper part 11 of the mold and the lower part 12 of the mold.

[0094] In some embodiments, a protective cover 211 of a quenching device 211 is installed on the device frame 21 to protect against splashing of the working medium during the quenching process. In addition, a mold fixing portion 212 is additionally installed on the device frame 21, and the hot mold 1 can be installed and replaced using the mold mounting portion 212.

[0095] In a specific embodiment, the hot-forming device 2 includes a device frame 21 and a device base. The device frame 21 includes two sections, wherein one of the two sections is installed on the device base, and the other of the two sections serves as a support for the transmission unit 24. The two sections of the device frame and the device base constitute the supporting structure of the device, which functions as a support base for installing all mechanisms, serves as a support for the mechanisms, and provides installation parts for standard components. The drive component 24-1 forms a power system for vertical movement and positioning of the device. The brake transmission component 24-5 is configured to transmit power from the drive component 24-1 and brake when positioning is required.The power conversion component 24-2 is configured to expand the space for the power transmission system, ensuring uniform force distribution across the entire working surface. The torque transmission mechanism 24-3 is configured to expand the force-bearing space of the device and increase the downward clamping force of the device. The guide mechanism 210 is configured to smoothly move the upper slider 22 in the vertical direction, wherein the upper slider 22 has mounting grooves and a mounting plate for mounting the upper part 11 of the mold. The hot-forming mold 1 is a hot-forming mold 1 divided into hot and cold forming zones, which is configured to harden the hot-formed components.The lower slider 23 has mounting slots and a mounting plate, which serve as mounting parts for the lower mold portion 12 and are configured to secure the lower mold portion to the hot-forming mold 1. The compensating pneumatic cylinder 24-7 is configured to balance the physical weights of the mounting slots and mounting plate on the upper slider 22, as well as the upper mold portion 11, thereby reducing the torque and power of the power system and achieving energy savings. The exhaust gas collection device is configured to collect exhaust gas generated during the quenching process during hot-forming for centralized return and cleaning, while allowing for air regeneration within the device every 10 seconds.The upper branch pipe 26 of the water channel is configured to be connected to the upper part 11 of the hot-forming mold 1, divided into soft-hard zones, to supply the upper part 11 of the hot-forming mold 1 with a working medium for the quenching operation. The lower branch pipe 27 of the water channel is configured to be connected to the lower part 12 of the hot-forming mold 1, divided into soft-hard zones, to supply the lower part 12 of the mold with a working medium for the quenching operation. When using the above-described configurations, the power consumption of the device is reduced, the efficiency of the device is increased, and the installation area of ​​the device is reduced.

[0096] The embodiments in the present description are described in a step-by-step manner, and each embodiment focuses on a difference from other embodiments. Identical or similar portions in each embodiment may be cross-referenced with each other.

[0097] The hot-forming mold proposed in accordance with the present application is described above in detail. The principle and implementation of the present application are explained herein using specific embodiments. The above descriptions of the embodiments serve only to facilitate the understanding of the method and the main idea of ​​the present application. It should be noted that those skilled in the art can make a number of improvements and modifications to this application without departing from the principle of the present application, and these improvements and modifications are within the scope of protection of the present application.

Claims

1. A hot forming mold comprising: an upper part (11) of the mold and a lower part (12) of the mold, wherein between the upper part (11) of the mold and the lower part (12) of the mold a profiled cavity is formed for placing the workpiece (4), each of the upper part (11) of the mold and the lower part (12) of the mold has a cavity inside and contains hollow sections (13) in predetermined positions on one side thereof in the direction of the profiled cavity, and the hollow sections (13) communicate with the cavity, allowing the injection of the working medium from the cavity onto the workpiece (4) through the hollow sections (13); a plurality of injection elements (14) which are installed in the cavity of the upper part (11) of the mold and / or the cavity of the lower part (12) of the mold; and a plurality of pipelines (15) for the working medium located in the said cavity, wherein the plurality of pipelines (15) for the working medium are configured to supply the working medium to the injection elements (14), wherein the pressure in each of the plurality of pipelines (15) for the working medium is adjustable, wherein the hollow sections (13) are located between each two adjacent support contact sections (110), and the support contact sections (110) and the hollow sections (13) are located alternately; and each of the supporting contact sections (110) has the shape of an elastic beam, wherein each of the support contact sections (110) has a width in the range from 3 mm to 50 mm, and each of the hollow sections (13) has a width in the range from 3 mm to 90 mm; and / or the distance between the injection element (14) and the workpiece (4) is in the range from 120 mm to 660 mm; and / or the injection element (14) has a conical injection shape with an apex angle less than or equal to 125 degrees.

2. A hot forming mould according to claim 1, wherein the pressures in at least two of the plurality of working medium pipelines (15) differ from each other; or the temperatures of the working medium in at least two of the plurality of pipelines (15) of the working medium differ from each other; or the types of working medium in at least two of the plurality of working medium pipelines (15) differ from each other.

3. A hot-forming mold according to claim 1, further comprising a connecting plate (16) of the upper part of the mold and a connecting plate (17) of the lower part of the mold, wherein the upper part (11) of the mold is mounted on the connecting plate (16) of the upper part of the mold and moves together with the connecting plate (16) of the upper part of the mold, and the lower part (12) of the mold is mounted on the connecting plate (17) of the lower part of the mold and moves together with the connecting plate (17) of the lower part of the mold.

4. A hot forming mould according to claim 1, wherein the hollow sections (13) are located in positions corresponding to the solid zones of the blank (4), and the injection elements (14) are installed in positions aligned with the hollow sections (13).

5. A hot forming mould according to claim 1, wherein the support contact sections (110) are made of stainless steel.

6. A hot forming mould according to any one of claims 1-5, further comprising connecting elements for installing a plurality of working medium pipelines (15) in the cavity, wherein the positions of the connecting elements are adjustable to change the positions and angles of the plurality of working medium pipelines (15) in the cavity.

7. A hot forming mold according to any one of paragraphs 1-5, further comprising: a plurality of pressure devices, wherein the number of the plurality of pipelines (15) of the working medium coincides with the number of the plurality of pressure devices, and the plurality of pressure devices is in one-to-one correspondence with the plurality of pipelines (15) of the working medium; and a controller connected to pressure devices, wherein the controller is configured to obtain the positions of the soft and hard zones of the workpiece (4) and to determine the target pressures required for individual pipelines (15) of the working medium, based on the positions of the soft and hard zones of the workpiece (4), and the controller is further configured to control the operation of the pressure devices based on the target pressures.

8. A hot-forming device comprising a hot-forming mould (1) according to any one of claims 1 to 7.

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