Press system and method

Abstract

A press apparatus and method for manufacturing a hot-formed structural member are provided. The apparatus includes a cooling tool, a press tool disposed downstream from the cooling tool, and a transport mechanism for transporting a blank from the cooling tool to the press tool. The cooling tool includes an upper gas-cooled tool connected to a movable upper body and a lower gas-cooled tool connected to a fixed lower body. The press apparatus includes an upper press die connected to the upper body and a lower press die connected to the lower body.

Description

[Technical field]

[0001] This application claims the benefit of priority from European Patent Application 19382899.3, filed on 14 October 2019. The present invention relates to a press system and method for producing hot-formed structural components. [Background technology]

[0002] In automotive structures, the development and implementation of lightweight materials or components is becoming increasingly important to meet the standards of lightweight construction. The demand for weight reduction is especially driven by the goal of reducing CO2 emissions. Increasing concerns for occupant safety, together with improved energy absorption, are driving the adoption of materials that improve the integrity of the vehicle in the event of a crash.

[0003] A process known as Hot Forming Die Quench (HFDQ) (also called hot stamping or press hardening) uses boron steel sheet to create stamped parts having ultra-high strength steel (UHSS) properties, for example, tensile strengths of up to 1500 MPa, 2000 MPa, or greater than 2000 MPa. Because of the increased strength compared to other materials, thinner gauge material can be used, resulting in weight savings compared to conventional cold stamped mild steel parts.

[0004] The steel sheet may be coated or uncoated, but a coating may be applied before, during or after the hot stamping process to improve corrosion protection. For example, aluminum-silicon coatings or zinc coatings are known.

[0005] Depending on the composition of the original steel, it may be necessary to quench (e.g., rapidly cool) it to obtain high tensile strength. Quenching means having a cooling rate greater than the critical cooling rate of the material being used (e.g., roughly 30°C / sec). Other steels may have relatively slow cooling rates. Examples of steels are known that can be air-cooled at room temperature and hardened at relatively slow cooling rates.

[0006] For example, the hot stamping process may be performed in such a manner that the hot worked blank is heated, for example, by a furnace system, to a predetermined temperature above the austenitizing temperature to reduce strength to facilitate the hot stamping process. The hot formed blank is formed by a press system and temperature control at a lower temperature (e.g., room temperature) compared to the blank. Thus, the forming process and heat treatment can be performed using a temperature difference.

[0007] It is known to use a multi-stage press system for producing hot-formed elements. The multi-stage press system may comprise a number of tools arranged to carry out different processes simultaneously on a blank. With such an arrangement, different production steps can be carried out simultaneously on a number of blanks, with the tools forming the multi-stage press system in each stroke. The use of such a multi-stage press system allows for a high production output.

[0008] The multi-stage pressing system may include a conveyor or transfer device that transfers the heated blank to a press tool configured to press the blank. Additionally, the tool may be included in the multi-stage pressing system and may be, for example, any of a punching tool, a calibrating tool, a cutting tool, a trimming tool, a second press tool, etc. Additionally, a furnace system may be included upstream from the multi-stage pressing system or device to heat and soften the blank to be hot formed.

[0009] Typically, such systems use an external pre-chilling tool to pre-chill the blanks that are to be hot formed. For example, zinc coated steel blanks typically need to be cooled prior to the hot forming process to minimize problems such as microcracking. Once the blanks have cooled, they are transferred from the external pre-chilling tool to a multi-stage press or system.

[0010] Patent Document 1 discloses a press system for manufacturing hot-formed structural members. The system comprises a fixed lower body, a movable upper body, and a mechanism for providing a pressing process in which the movable upper body moves upwards and downwards relative to the fixed lower body. The system further comprises a cooling tool configured to cool the preheated blank. The cooling tool comprises a pair of upper and lower dies, i.e. a lower die connected to the lower body with one or more lower biasing elements and / or an upper die connected to the upper body with one or more upper biasing elements. The system further comprises a press tool configured to stretch the blank, the press tool being arranged downstream from the cooling tool.

[0011] The system described in the patent document 1 speeds up the manufacturing process. To ensure this, the cooling tool is adapted to quickly and thoroughly cool the blank. The cooling tool is "closed" before the press tool is closed, due to a biasing element that applies a force to the upper and lower cooling dies that are in contact with the blank before the press tool closes. By integrating the tools in the same press, the transfer time from the cooling tool to the drawing tool can be reduced, thus optimizing the process and improving productivity while still providing satisfactory formability without cracking the blank. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] European Patent No. EP3067128 Summary of the Invention [Problem to be solved by the invention]

[0013] However, cooling tools with contact plates require strict maintenance and are moreover complicated to provide uniform and constant cooling during production, and it takes a relatively long time (with corresponding loss of product) before the desired cooling is stably achieved, especially when starting a new batch of products or when starting production after an interruption, such as at the start of a working day.

[0014] This disclosure seeks improvements in multi-step processes and systems. [Means for solving the problem]

[0015] In a first aspect, a press apparatus for manufacturing a hot-formed structural component is provided. The press apparatus comprises a fixed lower body, a moving upper body, and a mechanism configured to provide a pressing stroke in which the moving upper body moves upwards and downwards relative to the fixed lower body. The apparatus further comprises a cooling tool configured to cool an already heated blank, a press tool configured to stretch the blank and disposed downstream from the cooling tool, and a blank transport mechanism configured to transport the blank from the cooling tool to the press tool.

[0016] Here, the cooling tool comprises an upper gas-cooled tool connected to the moving upper body and / or a lower gas-cooled tool connected to the fixed lower body, and the press tool comprises an upper press die connected to the upper body and a lower press die connected to the lower body.

[0017] According to this embodiment, a multi-stage press is provided in which the cooling tool and the pressing tool are combined, which allows a speed-up of the production process and a higher output. The integration of the tools in the same press allows the transfer time from the cooling tool to the drawing tool to be reduced, thus optimizing the process and improving productivity while still providing a satisfactory formability of the blank without cracks, etc.

[0018] Gas cooling requires relatively little maintenance. It is relatively easy to achieve a consistent and uniform cooling process with gas cooling. For example, gas cooling does not suffer from the disadvantages associated with the use of contact plates.

[0019] Providing gas cooling in a multi-stage press also provides versatility. For example, for a relatively thin blank, only a lower gas cooling tool can be used. If the same process is performed on a thicker blank, an upper gas cooling tool can be added. In that case, cycle time can still be kept short. If desired, the cooling tools disclosed herein provide flexibility in terms of cooling parameters including cooling time, cooling gas temperature, cooling flow rate, etc.

[0020] In some cases, there is one cooling tool. For example, there can be only a lower cooling tool connected to the lower body. In this case, the press device is more reliable and more cost-effective. In other cases, there can be only an upper cooling tool connected to the moving upper body. In this case, the upper cooling tool can be connected to the moving upper body by means of a biasing element, which applies a force on the upper cooling tool towards the fixed lower body.

[0021] The biasing element allows the upper gas cooling tool to reach the correct position for the blank to be cooled before being stretched / pressed by the press tool, thus allowing the cooling cycle to be longer than the stretching cycle in one stroke in the same press apparatus.

[0022] In a further example, an upper gas cooling tool is connected to the moving upper body and a lower gas cooling tool is connected to the fixed lower body. In such a case, the moving upper body can be connected to the upper gas cooling tool by one or more biasing elements. The upper biasing elements can bias the upper gas cooling tool away from the moving upper body. The lower gas cooling tool can be connected to the fixed lower body with one or more lower biasing elements, which can bias the lower gas cooling tool away from the fixed lower body.

[0023] In one example, an upper gas cooling tool is positioned at a first predetermined distance relative to the blank and a lower gas cooling tool is positioned at a second predetermined distance relative to the blank at the bottom of the press cycle. Effective and most predictable gas cooling is achieved when air is blown onto the blank from a range of predetermined distances relative to the blank. A distance must be maintained between the cooling tool and the blank at the bottom of the press cycle.

[0024] The predetermined first distance may be equal to the predetermined second distance so as to provide substantially equal cooling to the upper and lower surfaces of the blank.

[0025] In one example, the cooling tool may include a stopper that maintains a minimum distance between the upper gas cooling tool and the blank (or a lower gas cooling tool that supports the blank).

[0026] In one example, the cooling tool can provide a stopper on the upper gas-cooled tool, which generates a force opposing the biasing element so that the stopper can contact the lower gas-cooled tool (or the fixed lower body). Such a force opposing the biasing element can ensure that the distance is maintained as the press stroke continues. As the moving upper body continues to move towards the fixed lower body, the biasing element is compressed, which can maintain the distance between the gas-cooled tool and the blank.

[0027] In one example, the stopper can be a rod or bar.

[0028] In some instances, the apparatus can be configured to initiate a cooling cycle when a minimum distance between the upper and lower gas cooling tools is reached. If the air flow from both sides is substantially equal and comes from the same distance, uniform cooling on both sides can be achieved. For example, enhanced cooling for relatively thick blanks can be achieved with upper and lower cooling tools. The cooling cycle in these instances can also be intermittent. Such intermittent cooling cycles can be used in instances where only a lower gas cooling tool or only an upper gas cooling tool is provided. Once the blank is positioned, the cooling cycle can be performed.

[0029] In other instances, cooling can be substantially continuous, for example the flow of cooling gas is constant so that cooling can begin as soon as the blank is delivered to the cooling tool, and this can be done with either one gas cooling tool or two gas cooling tools.

[0030] In one example, the biasing element can comprise one or more springs. In a further example, the biasing element can comprise a hydraulic or pneumatic actuator.

[0031] In some examples, the upper gas cooling tool and / or the lower gas cooling tool include a number of slots connected to a reservoir of compressed gas, and the system further includes a controller for controlling the flow of gas from the reservoir through the slots. The gas flow rate, gas temperature, and distance from the slots to the blank can control the cooling rate and temperature achieved. In some examples, the system can further include a temperature controller for the compressed gas in the reservoir.

[0032] In one example, the slots may be oriented substantially perpendicular to the blank.

[0033] In one example, the gas can be air and can be at substantially room temperature. This aspect can provide a cost-effective system.

[0034] In some instances, the upper press die and / or lower press die of the press tool include channels for directing cooling liquid or air. In some instances, the material of the blank and the desired microstructure of the resulting part may require or be desirable for a high cooling rate. The press tool may be temperature controlled to provide an appropriate high or low cooling rate. The cooling rate may be different in one portion of the blank than in another portion of the blank, thus allowing the resulting microstructure to be different in such different regions.

[0035] In one example, the temperature of the upper and / or lower press dies is controlled based on the temperature of the working surface of one of the dies. The press apparatus can include one or more thermometers on the working surface of one of the press tools.

[0036] In one example, the press device can be a mechanical press. In another example, the mechanical press can be a servo-mechanical press. In a further example, the press device can be a hydraulic press. The methods and systems disclosed herein can be implemented with a variety of press device types. Mechanical and servo-mechanical presses can provide high power output, while biasing elements within the device allow flexibility in adjusting the cooling cycle.

[0037] In one example, the press apparatus can further include a first post-processing tool configured to perform a first post-processing. The first post-processing tool is disposed downstream from the press tool and includes upper and lower first post-processing tool dies. The upper first post-processing tool die is connected to the upper body and the lower first post-processing tool die is connected to the lower body. Here, the blank transport device is further configured to transport the blank from the press apparatus to the first post-processing tool.

[0038] Multiple stages and processes can be added to the same press apparatus. Processes performed after stretching of the blank are referred to herein as "post-processing."

[0039] In some instances, the first post-processing includes trimming and / or cutting the blank, and the upper and / or lower first post-processing dies can include one or more cutting blades.

[0040] To control the temperature during processing, the upper and / or lower first post-processing tool dies can include one or more heaters or channels for conducting hot liquids. It is beneficial to maintain a minimum temperature of the blank to maintain deformability and to facilitate cutting, trimming or other machining operations. This can reduce wear on the post-processing tools.

[0041] To this effect, in one example, a heater or flow passages conducting hot liquid can be configured to maintain the blank at a temperature greater than 200° C. based on the temperature measured at the die of the first post-processing tool.

[0042] In some examples, the upper and / or lower first post processing mold can include channels for conducting a coolant, possibly water. In some examples, the temperature of the upper and / or lower first post processing mold can be controlled based on the temperature of the working surface of one mold. In some cases, a thermometer can be provided on the working surface of the first post processing tool mold.

[0043] In one example, the press apparatus can further include a second post-processing tool, the second post-processing tool being disposed downstream of the first post-processing tool. The blank transport mechanism can be configured to transport the blank from the first post-processing tool to the second post-processing tool, the upper second post-processing tool die being connected to the upper body and the lower second post-processing tool die being connected to the lower body.

[0044] In some examples, the second post-processing tool is configured to perform trimming and / or drilling.

[0045] In some examples, the second post processing tool can be configured to perform the calibration, hi such examples, the second post processing tool can include an adjustment device configured to adjust the distance between the upper and lower second post processing tool dies to deform the blank, the adjustment device being controlled based on a sensor system configured to detect a thickness of the blank.

[0046] The temperature control of the second post-treatment tool may be the same or similar to the temperature control of the first post-treatment tool.

[0047] In a further embodiment, a method of hot forming a blank can be provided. The method includes providing a press apparatus according to any of the examples described herein, and providing a blank made of zinc coated ultra high strength steel (UHSS). The method includes heating the blank, placing the blank in a cooling tool, and cooling the blank while applying a downward pressing stroke of the moving upper body against the fixed lower body. The method further includes applying an upward pressing stroke of the moving upper body against the fixed lower body, positioning the blank in the press tool, and elongating the blank by applying downward and upward pressing strokes of the moving upper body against the fixed lower body.

[0048] In some instances, the blank can be heated to a temperature above the austenitizing temperature of the UHSS. The blank can be heated to a temperature above an Ac1 temperature, and in some instances, the blank can be heated to a temperature above an Ac3 temperature.

[0049] In one example, the blank may be heated to a temperature between 860°C and 910°C.

[0050] In one example, the UHSS may include, by weight, 0.20-0.50% C, 0.75-1.5% Si, and 1.50-2.50% Mn. Preferably, the UHSS may include, by weight, 0.21-0.25% C, 1.05-1.33% Si, and 2.06-2.34% Mn. More preferably, a UHSS of such composition may be air-hardened. In some cases, the UHSS may further include Mn, Al, Ti, B, P, S, and N.

[0051] UHSS can be provided with a protective coating to improve protection against corrosion before, during and after the hot stamping process. This coating can be a zinc coating or an aluminum-silicon coating.

[0052] In one example, the blank can be cooled in a cooling tool to a temperature between 400° C. and 600° C. In zinc-coated UHSS, cooling to this temperature before drawing can prevent cracking. The temperature range is such that good formability is maintained in the subsequent drawing step.

[0053] When using UHSS blanks with an aluminum-silicon coating, there is no need to perform shot blasting to remove some or all of the zinc oxide layer after the hot stamping process. The overall improvement is achieved by using a multi-stage system.

[0054] In one example, the method can further include cooling the blank during drawing, hi one example, the blank can be cooled to a temperature between 320°C and 280°C during drawing.

[0055] In one example, the temperature of the blank may be maintained at greater than 200° C. in the first post-treatment tool and possibly also in the second post-treatment tool.

[0056] In one example, the blank can be formed of a UHSS, the UHSS including, by weight, 0.15-0.25% C, up to 0.5% Si, up to 2.5% Mn, 0.002-0.005% B, and up to 0.05% Cr. In one example, the UHSS can further include Al, Ti, P, and Mo.

[0057] In one example, the blank can be formed of UHSS, the UHSS including, by weight, 0.15-0.25% C, max 1% Si, max 2.5% Mn, 0.002-0.005% B, and 0.5-0.7% Cr. Preferably, the UHSS material includes, by weight, 0.15-0.25% C, max 0.5% Si, max 2.5% Mn, 0.002-0.005% B, and max 0.5% Cr. In one example, the UHSS can further include Al, Ti, P, and Mo.

[0058] In an alternative embodiment, the UHSS includes, by weight, 0.15-0.25% C, max 0.5% Si, max 2.5% Mn, 0.002-0.005% B, and max 0.5% Cr, preferably about 0.3% Cr. In one embodiment, the UHSS can further include Al, Ti, P, and Mo.

[0059] UHSS having the composition in the preceding paragraph is not configured for air hardening and instead requires higher cooling rates to achieve a martensitic microstructure.

[0060] In one example, the non-air hardened steel can be a 22MnB5 steel. Usibor® 1500P is an example of a 2MnB5 steel. The composition of Usibor® is summarized below by weight percent (the balance being iron (Fe) and unavoidable impurities):

[0061] (Table 1) TIFF0007678798000001.tif26144

[0062] After hot stamp die quenching, Usibor® 1500P can, for example, have a yield strength of 100 MPa and an ultimate tensile strength of 1500 MPa.

[0063] Usibor® 2000 is another boron steel with higher strength. After hot stamp die quenching, Usibor® 2000 can have a yield strength of over 1400 MPa and an ultimate tensile strength of 1800 MPa. The composition of Usibor® 2000 can include, by weight, 0.37% maximum carbon, 1.4% maximum manganese, 0.7% maximum silicon, and 0.005% maximum boron.

[0064] In non-air hardened UHSS, a first cooling of the blank prior to stretching of the blank can be performed from above the austenitizing temperature to a temperature between 600° C. and 800° C., possibly between 650° C. and 700° C. As a result, during forming, the temperature of the blank can be reduced to a temperature between 450° C. and 250° C., possibly between 320° C. and 280° C. [Brief description of the drawings]

[0065] [Figure 1] FIG. 1 is a schematic diagram of a multi-stage press system according to an embodiment of the present invention. [Figure 1A] 2A-2C are schematic diagrams illustrating a sequence of steps during the blank cooling and forming method using the multi-stage press system shown in FIG. [Figure 1B] 2A-2C are schematic diagrams illustrating a sequence of steps during the blank cooling and forming method using the multi-stage press system shown in FIG. [Figure 1C] 2A-2C are schematic diagrams illustrating a sequence of steps during the blank cooling and forming method using the multi-stage press system shown in FIG. [Figure 1D] 2A-2C are schematic diagrams illustrating a sequence of steps during the blank cooling and forming method using the multi-stage press system shown in FIG. [Figure 1E] 2A-2C are schematic diagrams illustrating a sequence of steps during the blank cooling and forming method using the multi-stage press system shown in FIG. [Figure 1F] 2A-2C are schematic diagrams illustrating a sequence of steps during the blank cooling and forming method using the multi-stage press system shown in FIG. [Figure 2a] FIG. 13 is a schematic diagram of another embodiment of a multi-stage press system. [Figure 2b] FIG. 2b is a schematic diagram of the upper gas cooling tool of the embodiment shown in FIG. 2a. [Figure 3A] 1A-1D are schematic diagrams showing a series of events occurring during the implementation of a blank cooling and forming method according to an embodiment; [Figure 3B] 1A-1D are schematic diagrams showing a series of events occurring during the implementation of a blank cooling and forming method according to an embodiment; [Figure 3C] 1A-1D are schematic diagrams showing a series of events occurring during the implementation of a blank cooling and forming method according to an embodiment; [Figure 3D] 1A-1D are schematic diagrams showing a series of events occurring during the implementation of a blank cooling and forming method according to an embodiment; [Figure 3E] 1A-1D are schematic diagrams showing a series of events occurring during the implementation of a blank cooling and forming method according to an embodiment; [Figure 3F] 1A-1D are schematic diagrams showing a series of events occurring during the implementation of a blank cooling and forming method according to an embodiment; [Figure 4] FIG. 13 is a schematic diagram illustrating a further embodiment of a multi-stage press system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0066] Non-limiting examples of the present disclosure are described below with reference to the drawings. Figure 1A shows a schematic diagram of an example of a multi-stage pressing system. The device 1 comprises a fixed lower body 2, a moving upper body 3, and a mechanism (not shown) configured to impart upward and downward pressing strokes of the moving upper body 3 against the fixed lower body 2.

[0067] The fixed lower body 2 can be a large block made of metal. In this particular example, the fixed lower body 2 can be a stationary member. In one example, the fixed lower body 2 can be provided with a mold cushion (not shown) integrated therein. The cushion can be configured to receive and control the force of the blank holder. The moving upper body 3 can also be a solid member made of metal. The moving upper body 3 can provide a stroke cycle (up and down movement).

[0068] The press system can be configured to perform approximately 30 strokes per minute. Thus, each stroke cycle can be approximately 2 seconds. The stroke cycle can vary in further examples.

[0069] The mechanism of the press can be mechanically, hydraulically or servo-driven. The stroke of the moving upper body 3 relative to the fixed lower body 2 is determined by this mechanism. In this particular example, the press can be a servo-driven press, so that a constant press force can be applied during the stroke. A servo-driven press can obtain a good range of press forces at any slide position, so that a large flexibility of the press can be realized. A servo-driven press can improve process conditions and productivity in metal forming. The press can have a press force of, for example, 2000 Tn.

[0070] In one example, the press is a mechanical press, so that the pressing force stroke towards the fixed lower body 2 can be by a drive and hinge system. A mechanical press can therefore achieve higher cycles per unit time. Alternatively, a hydraulic press can be used.

[0071] A cooling tool configured to cool a preheated blank 80 is shown in FIG. 1. The cooling tool 10 may include a lower gas cooling tool 12. The lower gas cooling tool may include an air knife. The lower gas cooling tool 12 may include a compressed air plenum including a series of holes or continuous slots through which compressed air flows, preferably in a laminar flow pattern.

[0072] The air exiting the slots or holes impinges on the heated blank 80, thus cooling the blank 80.

[0073] The lower gas cooling tool can include various control mechanisms, such as for example controlling the temperature of the gas in the compression plenum, and alternatively or additionally, can include one or more valves that control the flow of air towards the blank.

[0074] The advantage of using gas cooling is that the cooling profile (temperature vs. time) can be precisely controlled, and it is relatively easy to maintain uniform cooling throughout a production cycle, for example, over the course of a day.

[0075] For example, the cooling tool may be equipped with centering elements such as pins, blank holders 16 and / or guide devices.

[0076] The pin or holder 16 may always keep the blank 80 spaced a distance d1 from the lower gas cooled tool 12.

[0077] In this example, a press tool 20 configured to form or stretch a blank is provided and integrated into a multi-stage press system. The press tool 20 is located downstream from the cooling tool 10. The press tool 20 includes a pair of upper and lower dies 21 and 22. The term paired here means that the dies have complementary shapes such that as the upper die 21 moves towards the lower die 22, the blank disposed therebetween is deformed.

[0078] In this special case, a blank 70 is shown to undergo a forming or drawing step in the next press cycle, the blank 70 from the previous cycle obviously undergoing a cooling step in the cooling tool 10.

[0079] The upper tool 21 has an upper running surface 23 which, in use, faces a blank to be hot formed. The lower tool 22 has a lower running surface 24 which, in use, faces a blank to be hot formed. The side or part of the upper tool opposite the upper running surface 23 can be connected to the upper body 3 and the side or part of the lower tool opposite the lower running surface 22 can be connected to the lower body 2.

[0080] The pair of upper and lower dies 21 and 22 may have grooves through which cold fluids such as water and / or cold air flow. The circulation speed of the water flowing through the grooves may be increased so that evaporation of the water in the grooves can be avoided. A control system for controlling the temperature of the dies may also be provided.

[0081] In an embodiment, the press system 20 includes a blank holder 25 configured to hold a blank and position the blank over the lower die 22. The blank holder includes one or more biasing elements configured to bias the blank holder to a predetermined distance from the lower die 22.

[0082] A first post-processing tool 30 may be provided which is configured to perform a trimming and / or drilling operation. In this particular example, in the next stroke of the press, the blank 60 undergoes a trimming or cutting operation. It is clear that the blank 60 has already undergone a cooling operation by the cooling tool 10 and a forming operation by the pressing tool 20.

[0083] The first post processing tool 30 is located downstream of the press tool 20. The first post processing tool 30 may include an upper die 32 and a lower die 31. The upper die 32 may include an upper working surface 33 and the mating lower die 32 may include a lower working surface 34. In use, both working surfaces face the blank 60.

[0084] The side of the upper mold 32 opposite the upper running surface 33 can be attached to the upper body 3, and the side of the lower mold 31 opposite the lower running surface 34 can be attached to the lower body 2. The molds can include one or more knives or cutting blades (not shown) disposed on the running surfaces.

[0085] The first post-treatment tool 30 may include one or more electric heaters or channels for conducting hot fluid, and a temperature sensor for controlling the temperature of the mold. The sensor may be a thermocouple. In one example, it is preferred to maintain the temperature of the blank located between the upper and lower molds at or near a predetermined temperature, e.g., greater than 200°C, greater than 250°C, or greater than 300°C, during use.

[0086] In one example, the pair of upper and lower dies 32, 31 may have grooves through which a cold fluid, such as water and / or cold air, flows.

[0087] In an embodiment, the first post-processing tool 30 may include a blank holder (not shown) configured to hold a blank and position the blank over the lower die 31. The blank holder may include one or more biasing elements configured to bias the blank holder to a predetermined distance from the lower die.

[0088] In the embodiment shown in Figure 1, a second post processing tool 40 is provided. The second post processing tool 40 may also be configured to perform further trimming and / or drilling operations. The second post processing tool 40 is located downstream from the first post processing tool 30. The second post processing tool 40 may comprise an upper die 42 and a lower die 41. The mating upper die 42 may have an upper working surface 43 and the mating lower die 41 may have a lower working surface 44. In use, both working surfaces face the blank 60. The working surfaces are not smooth, e.g. having raised areas and recesses.

[0089] The side of the upper mould 42 opposite the running surface 43 can be connected to the upper body 3 and the side of the lower mould 41 opposite the running surface 44 can be connected to the lower body 2 .

[0090] The dies may include one or more knives or cutting blades disposed on the working surfaces. In some examples, an adjustment device (not shown) may be provided for adjusting the distance between the upper die 42 and the lower die 41. In this way, in use, the blank 50 located between the upper die 42 and the lower die 41 may be deformed along the working surfaces of the upper and lower dies, respectively.

[0091] Once the distance between the upper and lower dies 42, 41 for deformation has been adjusted (i.e., the blank has been calibrated), the tolerance of the hot formed blank is improved. In some instances, the hot formed blank has non-optimized areas, e.g., some parts of the blank have a greater thickness than other parts, i.e., the thickness needs to be optimized.

[0092] By providing a non-uniform running surface, the distance in selected regions of the running surface (e.g., near the radius of the blank) is adjusted at or near the region having a non-optimized thickness, i.e., a constant thickness along the blank can be achieved.

[0093] In an embodiment, the adjustment device may be controlled based on a sensor system configured to detect the thickness of the blank.

[0094] In one example, the second post-processing tool 40 can include a blank holder (not shown) configured to hold a blank and position the blank over the lower die 41. The blank holder includes one or more biasing elements configured to bias the blank holder to a predetermined distance from the lower die.

[0095] In further examples, other methods can be envisaged that are adapted to run the tool die at lower or higher temperatures.

[0096] Although the drawings depict the mold as being substantially square or rectangular in shape, it should be understood that the blocks may have other shapes and may also have a partially rounded shape.

[0097] For example, a number of industrial robots or automated transport devices (not shown), such as conveyors, may be provided in the tool and transport system. The tool may further comprise a cooling system, blank holders, etc.

[0098] In all instances, temperature sensors and control systems for controlling the temperature may be provided on any tool or on the transport system. The tool may be equipped with further cooling systems, blank holders etc.

[0099] 1A to 1F show diagrammatically the succession of steps which occur during the performance of a method for cooling and shaping a blank according to an embodiment, in which the same elements are given the same reference numbers.

[0100] For simplicity, reference angles for the press cycle are included in the description in connection with FIG. 1A (and further figures). The reference angles are used to indicate the approximate positions of the upper body relative to the lower body. Thus, for example, the reference angles indicate that when the upper body is at 0 degrees relative to the lower body, it is at its highest position relative to the lower body, when the upper body is at 180 degrees relative to the lower body, it is at its lowest position (full contact position) relative to the lower body, and when it is at 360 degrees, it is at its highest position again, indicating that the process cycle is complete.

[0101] In FIG. 1A, a hot formed blank 80 made of ultra high strength steel (UHSS) may have an Ac3 transformation point (austenite transformation point, hereinafter referred to as "Ac3 point") between 860 and 870°C. For the steel composition described above, the Ac3 point is approximately 867°C. The Ms transformation point (martensite start temperature, hereinafter referred to as "Ms point") may be between 380°C and 390°C. For the steel composition described above, the Ms point is 386°C. The Mf transformation point (martensite finish temperature, hereinafter referred to as "Ms point") is at or near 270°C.

[0102] Different steel compositions may be used. In particular, the steel compositions described in EP 2 735 620 A1 are considered suitable. Particular references are given in table 1 and in paragraphs 0016-0021 and the discussion in paragraphs 0067-0079 of EP 2 735 620.

[0103] The blank 80 can be heated to at least the austenitizing temperature. Heating is carried out in a heating device (not shown), such as for example a furnace. In this particular example, the maximum temperature to which the blank is heated can be determined by the coating. The melting point (i.e. evaporation temperature) of zinc is at or near 910°C, so the maximum temperature to which the blank 80 is heated in the heating device can be set to approximately below 910°C. The blank 80 can be heated to a temperature above the Ac3 temperature, but below the melting temperature of zinc at or near 910°C. Heating is therefore carried out to a temperature between 867°C and 910°C (for the steel composition described above), in particular to a temperature at or near 890°C. The duration of heating is approximately 6 minutes, but depends for example on the thickness of the blank.

[0104] Once the blank 80 has been heated to the desired temperature for a sufficient period of time, it can be transferred to the cooling tool 10. This transfer can be performed by an automated transfer device (not shown), such as, for example, an industrial robot or a conveyor. The transfer time of the blank between the furnace (not shown) and the cooling tool 10 can be between 2 and 3 seconds.

[0105] In some instances, a centering device, such as a pin and / or guide device, may be provided upstream from the cooling tool so that the blank is properly centered. The blank 80 may be placed on a pin or blank holder 16 that maintains a small distance between the lower gas cooling tool 12 and the blank 80.

[0106] The press upper body 3 can be positioned in an open position (0 degree position) and a blank 80 is placed on the gas cooled tool 11. In one example, the blank can be placed on a blank holder.

[0107] As mentioned above, the biasing device may comprise a spring, such as a mechanical spring or a gas spring, although other biasing elements may be used, such as a hydraulic mechanism, which may be a passive or active mechanism.

[0108] 1B, the lower pressing stroke of the moving upper body 1 is started against the fixed lower body 2. In this particular example, cooling has already begun, but in other examples the cooling cycle can be continuous, so that cooling can begin as soon as the blank 80 is positioned in the cooling tool.

[0109] A stream of pressurized cooling gas (which can be air) is applied to the blank. The gas flow can be controlled based on flow meter measurements. The gas pressure can be about 2 atmospheres. For example, the required gas flow, gas temperature and cooling time can be varied as a function of the thickness of the blank. A thicker blank will take longer to cool if lower gas temperatures and / or increased gas flow cannot be achieved.

[0110] The slots or holes through which gas flows towards the blank may be arranged substantially perpendicular to the plane of the blank.

[0111] In Figures 1C, 1E and 1G, deformation can be initiated in the press tool at temperatures between 130 and 180°C.

[0112] In Figure ID, after reaching the final desired position (180 degree position), the press mechanism performs an upward pressing stroke of the upper body. At the end of the cooling cycle, the upper body (i.e., the upper die) is at a position between 210 degrees and 270 degrees relative to the lower body.

[0113] As mentioned above, a cooling body can be used to cool the blank 80 in the press die while it is pressed. Zinc-coated ultra-high strength steel (UHSS) will develop microcracks if it is heated above 600° C. in the press tool. Thus, the blank can be cooled to a temperature below 600° C., in particular to a temperature between 500° C. and 600° C., preferably at or near 550° C., before being transferred to the press tool.

[0114] As already mentioned, the blank 80 can be preheated, for example by heating in a furnace, to around 890°C. The blank can be transferred to the cooling tool 100. During the transfer, the temperature can be reduced to between 850°C and 800°C, or between 850°C and 750°C. The blank is then cooled to a temperature of about 550°C.

[0115] With the cooling tool 100 integrated into the press system, the time for cooling the blank can be optimized since the extra movement of transporting the blank from the external cooling tool can be avoided, which also saves time. Moreover, the cooling rate can be easily controlled since the movement of the blank between the tools is limited.

[0116] In Fig. 1E, the blank 80 has already cooled and is therefore ready to be transferred from the cooling tool 10 to the press tool 20. Transfer can be performed, for example, by automated transfer devices such as industrial robots or conveyors. As mentioned above, the blank can be transferred at a temperature of or near 550°C. The transfer time allows the blank 80 to cool before reaching the forming tool.

[0117] While the above steps are being performed on blank 80, other steps can be performed on the other blanks 50, 60, 70. Post-processing of blanks 50 and 60 is performed while blank 70 is being stretched.

[0118] During forming, the final complete contact between the working surface of the upper die of the forming tool and the working surface of the blank (i.e., at the end of the drawing stroke) is between 180° and 210°. The final contact between the blank and the blank holder is, for example, between 210° and 270°.

[0119] During forming, the temperature of the blank 70 can be reduced to a temperature between 300° C. and 200° C., in particular 350° C.-370° C. The press tool can be equipped with a cooling system, which can be controlled by a controller, so that the temperature of the blank 70 can be reduced to and maintained at a desired temperature.

[0120] The blank 60, already stretched, is transported from the press tool 20 to the first post-processing tool 30 for punching or trimming. The transport can be performed by an automated transport device (not shown), such as a number of industrial robots or a conveyor. As mentioned above, the blank 60 can leave the press tool 20 at a temperature higher than 300°C, particularly 350-370°C. Depending on the transport time, the blank 60 may cool more or less. The blank 100 is placed on the lower die 31 and is arranged between the lower die 31 and the upper die 32.

[0121] The blank 60 is transported or placed onto the lower die 31 and the automated transport system is operated to feed the blank 200 to the press tool 20 and feed the blank 300 to the cooling tool 19. The cooling tool 10 can then be started to cool the blank 300, as described above. At the same time, the press tool 20 can be started to stretch and cool the blank 300, as described above.

[0122] In the first post-processing tool, when the final desired position (at or near the 180 degree position of the press cycle) is reached, the upper die 32 contacts only the blank 60 positioned between the press tool upper die 31 and the press tool lower die 31.

[0123] While the press is in contact with the blank 60, a punching step can be performed using a cutting blade or other cutting element. Once the punching step is completed, a trimming step can be performed. Alternatively, the trimming step can be performed first and the punching step can be performed after the trimming step is completed. The trimming and punching steps can also be performed substantially simultaneously.

[0124] While post-processing is being performed on blank 60, the blank may be heated using the heating device described above to maintain the blank above a minimum temperature to ensure deformation of the blank.

[0125] When the final desired position is reached (at or near the 180 degree position of the press cycle), the upper press stroke can be applied. Final complete contact between the working surface of the upper die 32 and the blank 100 (i.e., end of stroke) can be between 180 and 210 degrees. Final contact of the blank and blank holder (if provided in the post-operation tooling) can occur between 210 and 270 degrees of the press cycle.

[0126] Finally, in this particular example, the press includes a second post-processing tool, although in further examples, there may be no post-processing tool or three or more post-processing tools included in the press.

[0127] The second post-processing tool in this example can be used for drilling and / or trimming. Furthermore, a calibration step can be performed. Thus, the manufacturing tolerances of the blank can be improved. For this purpose, an adjustment device can be used to adjust the distance between the upper die 42 and the lower die 41. The adjustment device can be controlled based on a sensor system (not shown) arranged to detect the thickness of the blank 100. According to an example, the blank can be pressed with the upper die 42 and the lower die 41, so that a constant thickness of the blank can be maintained. As with the first post-processing tool, the die temperature (and therefore the blank temperature) can be controlled to ensure, inter alia, a minimum temperature of the blank.

[0128] Once the second post-processing tool step is complete, the blank can be transported and cured at room temperature.

[0129] In some instances, other steps such as further drawing, drilling and / or trimming may be performed depending on the desired shape of the final part. In further instances, the order of post-processing steps may be interchanged (e.g., cutting first, then calibration, etc.).

[0130] Another example of a multiple step pressing apparatus is shown in Figure 2a. In this example, a cooling tool 10 includes an upper cooling tool 11 and a lower cooling tool 12.

[0131] In a particular example, the upper gas cooling tool 11 is connected to the moving upper body 1 via one or more biasing elements. The biasing elements urge the upper gas cooling tool away from the moving upper body 1 and towards the fixed lower body 2. In this example, the biasing element can be a spring, such as a mechanical spring or a gas spring, although in other examples other biasing elements can be used. Such alternative biasing elements can include, for example, a hydraulic mechanism that urges the cooling tool towards an opposing cooling tool.

[0132] In another example, the lower gas cooling tool 12 can be connected to the fixed lower body 2 via one or more biasing elements. The working principle is similar to that of the upper gas cooling tool. In one example, both the upper gas cooling tool 11 and the lower gas cooling tool 12 can also be provided with biasing elements.

[0133] By inserting upper and / or lower biasing elements, the time for cooling can be adjusted and increased during the stroke cycle (up and down movement of the moving upper body 1 relative to the lower body 2). The biasing elements of the cooling tool allow the cooling to start before the contact of the pressing die of the forming tool (and further tools arranged downstream).

[0134] The upper gas-cooled tool is equipped with stoppers 14. They are shown in Fig. 2b. The stoppers 14 are rod-shaped and can come into contact with the lower gas-cooled tool 12 (or the fixed lower body) when the moving upper body 1 descends. The stoppers 14 ensure that the distance between the upper and lower gas-cooled tools is maintained. This means that the distance is maintained between the upper gas-cooled tool 11 and the blank 80.

[0135] The size and shape of the stopper can be determined so that during the part of the press cycle when cooling is taking place, the distance from the upper gas cooling tool 11 to the blank 80 (the distance between the lower gas cooling tool 12 and the blank 80) is maintained at distance d1.

[0136] With reference to Fig. 2b, an example of a possible arrangement of a number of stoppers 14 is shown. In this example, the stoppers 14 are generally straight rod-shaped. The tips 14A of the stoppers are flat and in this example may provide a contact surface with the lower gas cooling tool. As previously mentioned, the roles of the upper and lower cooling tools may be reversed. The rods 14 may be attached to the side 19 of the upper gas cooling tool 11. Fig. 1B shows a number of straight slots through which the compressed cooling gas flows towards the blank.

[0137] The upper biasing element 13 can be used to position the upper gas cooling tool 11 at a predetermined distance relative to the upper body 2 .

[0138] 3A-3F show a similar sequence of steps to those in Figures 1A-1F, but unlike the previous example, the cooling tool in this example includes both an upper gas-cooled tool 11 and a lower gas-cooled tool 12.

[0139] FIG. 3A shows the multiple step press apparatus of FIG. 2A before the pressing process begins, eg, the 0 degree position of the press cycle.

[0140] 3B shows the pressing apparatus starting the pressing process of moving the movable upper body 1 downward relative to the lower fixed body 2. Thus, the upper gas-cooled tool 11 moves towards the lower die 12 (and the blank 80 located on the lower tool 11).

[0141] The upper gas-cooled tool holds a stopper 14 that extends towards the lower gas-cooled tool 12. In FIG.

[0142] In Fig. 3C, 3E, 3G, for example, the stopper 14 contacts the lower cooling tool in the range between 90 degrees and 150 degrees of the press cycle. The blank 80 is then positioned at a predetermined distance from the upper gas cooling tool. The blank is also positioned at a predetermined distance relative to the lower gas cooling tool. The blank can be positioned at equal distances from the upper and lower gas cooling tools. With a well-defined distance from the blank to the upper and lower gas cooling tools, controlled cooling can be achieved.

[0143] As the pressing process continues, the biasing member remains compressed so as to maintain the distance between the upper and lower cooling tools and the distance between the cooling tool and the blank.

[0144] A stream of compressed cooling gas (which can be air) can be directed at the blank. The gas flow can be controlled based on flow meter measurements as described above. The gas pressure can be, for example, 2 atmospheres. The required gas flow rate and temperature can vary, for example, as a function of the thickness of the blank. If the gas temperature is not reduced and / or the gas flow rate increased, thicker blanks will take longer to cool. The use of upper and lower gas cooling tools ensures relatively short cooling cycles even for thick blanks.

[0145] In Fig. 3D, after reaching the final desired position (180 degree position), the pressing mechanism can provide an upward pressing step of the upper body. The end of the cooling cycle can be between 210 and 270 degrees of the upper body (i.e., the upper mold) relative to the lower body. The upper biasing element 13, which still appears partially compressed in the state of Fig. 3, can start to return to its initial position or configuration. With proper placement of the biasing element, the cooling period can be longer than the molding period, and the cooling cycle can last for a period between 0.33 and 1 second, for example.

[0146] 3E and 3F are generally similar to what is described in FIGS. 2E and 2F.

[0147] In the examples described herein, gas cooling is initiated when the blank is positioned at a specific, predetermined distance relative to the upper and lower cooling tools, although gas cooling may be initiated and continued prior to that, as is evident in other examples.

[0148] 4 shows a further example of a multi-stage pressing device, in which the cooling tool 10 does not have a lower cooling tool, but only an upper cooling tool 11. The upper gas cooling tool 11 can be connected to an upper moving body together with an upper biasing element 13.

[0149] The upper gas cooling tool may be provided with a stopper 14 as previously described. As in the previous example, the combination of biasing element 13 and stopper 14 allows the minimum distance between the cooling tool and the blank to be quickly reached and maintained, thus allowing the cooling cycle to be longer than the forming cycle.

[0150] For completeness, various aspects of the disclosure are disclosed in the following numbered sections:

[0151] Section 1: A press device for manufacturing hot-formed structural members, comprising a fixed lower body, a moving upper body, and a mechanism configured to provide a pressing process in which the moving upper body moves upwards and downwards relative to the fixed lower body, The press device is a cooling tool configured to cool the preheated blank; a press tool positioned downstream from the cooling tool and configured to elongate the blank; a blank conveying mechanism for conveying the blank from the cooling tool to the press tool; Equipped with The cooling tool includes an upper gas cooling tool connected to a moving upper body and / or a lower gas cooling tool connected to a fixed lower body; The press tool comprises an upper press die connected to an upper body and a lower press die connected to a lower body.

[0152] Clause 2: The press apparatus of clause 1, configured such that in the press cycle, the cooling time is longer than the stretching time.

[0153] Clause 3: The pressing apparatus of clauses 1 or 2, comprising a lower gas-cooled tool connected to the fixed lower body.

[0154] Clause 4: The pressing apparatus of clause 1 or 2, comprising an upper gas cooling tool connected to the moving upper body together with one or more upper biasing elements, the upper biasing elements biasing the upper gas cooling element away from the moving upper body.

[0155] Clause 5: The cooling tool comprises an upper gas cooling tool connected to the moving upper body and a lower gas cooling tool connected to the fixed lower body; 3. The press apparatus of claim 1 or 2, wherein an upper gas cooling tool is connected to the moving upper body along with one or more upper biasing elements that bias the upper gas cooling element away from the moving upper body, and / or a lower gas cooling tool is connected to the fixed lower body along with one or more lower biasing elements that bias the lower gas cooling element away from the fixed lower body.

[0156] Clause 6: The press apparatus of clauses 4 or 5, wherein at a lowest point in the press cycle, the upper gas cooled tool is positioned at a first predetermined distance relative to the blank and the lower gas cooled tool is positioned at a second predetermined distance relative to the blank.

[0157] Clause 7: The pressing apparatus of clause 6, wherein the predetermined first distance is equal to the predetermined second distance.

[0158] Clause 8: The press apparatus of any one of clauses 4 to 7, wherein the cooling tool is provided with a stopper that maintains a minimum distance between the upper gas cooling tool and the blank.

[0159] Clause 9: The pressing apparatus of clause 8, wherein a stopper is provided on the upper gas-cooled tool, the stopper contacting the lower gas-cooled tool such that a force opposite to the biasing element is generated.

[0160] Clause 10: The pressing device of clause 9, wherein the stopper is a rod or a bar.

[0161] Clause 11: The press apparatus of any of clauses 9-10, configured to initiate a cooling cycle when a minimum distance between the upper gas cooled tool and the blank is reached.

[0162] Clause 12: The pressing device of any of clauses 4 to 11, wherein the biasing element comprises one or more springs.

[0163] Clause 13: A press apparatus as described in any of clauses 1 to 12, wherein the upper gas-cooled tool and / or the lower gas-cooled tool have a plurality of slots connected to a reservoir of compressed gas, and the system includes a control unit for controlling the flow of gas from the reservoir through the slots.

[0164] Clause 14: The pressing apparatus of clause 13, wherein the slot is oriented substantially perpendicular to the blank.

[0165] Clause 15: The pressing apparatus of clause 14, wherein the gas is air at room temperature.

[0166] Clause 16: The press apparatus of any of clauses 13 to 15, further comprising a temperature control for the compressed gas in the reservoir.

[0167] Clause 17: A press apparatus according to any one of claims 1 to 16, wherein the upper press die and / or the lower press die of the press tool are provided with channels for conducting cooling liquid or cooling air.

[0168] Clause 18: The press apparatus of any one of clauses 1 to 16, wherein the temperature of the upper and / or lower press dies is controlled based on the temperature of a working surface of one die.

[0169] Clause 19: The press apparatus of clause 18, further comprising a thermometer on a working surface of one of the dies.

[0170] Clause 20: The press apparatus of any of clauses 1 to 19, which is a mechanical press.

[0171] Clause 21: The press apparatus of any of clauses 1 to 19, which is a servo mechanical press.

[0172] Clause 22: The pressing apparatus of any of clauses 1 to 19, which is a hydraulic press.

[0173] Clause 23: Further, a first post-processing tool for performing a first post-processing is provided, the first post-processing tool being disposed downstream of the press tool and including upper and lower first post-processing tool fittings; The upper first post-processing tool fitting is connected to the upper body, and the lower first post-processing tool fitting is connected to the lower body; 23. The press apparatus of any of clauses 1-22, wherein the blank transport device is further configured to transport the blank from the press tool to the first post-processing tool.

[0174] Clause 24: The press apparatus of clause 23, wherein the first post-processing step includes trimming and / or cutting the blank, and the upper and / or lower post-processing tools include one or more cutting blades.

[0175] Clause 25: The pressing apparatus of clause 23 or 24, wherein the upper and / or lower post-treatment tool comprises one or more heaters or channels for conducting hot liquid.

[0176] Clause 26: The press apparatus of clause 25, wherein the heater or hot liquid conducting flow passage is configured to maintain the temperature of the blank at approximately 250°C or 300°C based on a temperature measured at the die of the blank of the first post-treatment tool.

[0177] Clause 27: A press apparatus as claimed in any one of clauses 23 to 26, wherein the upper and / or lower post-treatment tool die is provided with channels for conducting a cooling fluid, optionally cooling water.

[0178] Clause 28: The press apparatus of any one of clauses 25 to 27, wherein the temperature of the upper and / or lower post-treatment tool dies is controlled based on the temperature of the working surface of one of the dies.

[0179] Clause 29: The press apparatus of clause 28, further comprising one or more thermometers on a working surface of one of the first post-treatment tool dies.

[0180] Section 30: Further comprising a second post-processing tool, the second post-processing tool being disposed downstream of the first post-processing tool, and the blank transport mechanism being configured to transport the blank from the first post-processing tool to the second post-processing tool; 30. The press apparatus according to any one of clauses 23 to 29, wherein the upper second post-processing tool die is connected to the upper body and the lower second post-processing tool die is connected to the lower body.

[0181] Clause 31: The pressing apparatus of clause 30, wherein the second post-processing tool is configured for trimming and / or drilling.

[0182] Clause 32: The second post-processing tool comprises an upper and / or lower second post-processing tool die; 32. The press apparatus of clause 31, wherein the upper and / or lower second post treatment tool die comprises one or more cutting blades.

[0183] Clause 33: A press apparatus as described in any one of clauses 30 to 32, wherein the second post-processing tool comprises an adjustment device configured to adjust the distance between the upper and lower second post-processing tool dies to deform the blank, and the adjustment device is controlled based on a sensor system configured to detect the thickness of the blank.

[0184] Clause 34: A press apparatus as described in any of clauses 30 to 33, wherein the temperature of the upper and / or lower first post-treatment tool dies is controlled based on the temperature of the working surface of one of the dies.

[0185] Clause 35: The press apparatus of clause 34, further comprising one or more thermometers on a working surface of one of the first post-treatment tool dies.

[0186] Section 36: A method for hot forming a blank, comprising the steps of: Providing a pressing apparatus according to any one of clauses 1 to 35; Providing a blank made of zinc coated ultra high strength steel (UHSS); Heating the blank; placing the blank in a cooling tool; cooling the blank while subjecting the moving upper body to a downward pressing stroke against the fixed lower body; performing an upward pressing process of the moving upper body against the fixed lower body; Positioning the blank in a press tool; - stretching the blank by performing downward and upward pressing of the moving upper body against the fixed lower body; A method comprising:

[0187] Clause 37: The method of clause 36, wherein the blank is heated to a temperature above the austenitizing temperature of the UHSS.

[0188] Clause 38: The method of clause 36 or 37, wherein the blank is heated to a temperature between 860°C and 910°C.

[0189] Clause 39: The method of any of clauses 36 to 38, wherein the UHSS comprises approximately 0.22% C, 1.2% Si, and 2.2% Mn.

[0190] Clause 40: The method of clause 39, wherein the UHSS further comprises Mn, Al, Ti, B, P, S, and N.

[0191] Clause 41: The method of any of clauses 36 to 40, wherein the blank is cooled in a cooling tool to a temperature between 500°C and 600°C.

[0192] Clause 42: The method of any of clauses 36 to 41, wherein the blank is cooled during drawing.

[0193] Clause 43: The method of clause 42, wherein the blank is cooled to a temperature between 400°C and 300°C during stretching.

[0194] Clause 44: The press device includes a first post-processing tool having upper and lower first post-processing tool dies having cutting blades; The upper first post-processing tool die is connected to the upper body, and the lower first post-processing tool die is connected to the lower body; The pressing apparatus according to any one of clauses 36 to 43, further comprising the steps of drilling and / or trimming the blank by transporting the blank from the pressing tool to a first post-processing tool, and performing downward and upward pressing strokes of the movable upper body against the fixed lower body.

[0195] Clause 45: The method according to clause 44, wherein the temperature of the blank located at the first post-treatment tool is maintained at a temperature higher than 200°C, in particular at a temperature higher than 300°C.

[0196] Clause 46: The press device includes a first post-processing tool having upper and lower second post-processing tool dies; The upper second post-processing tool mold is connected to the upper body, and the lower second post-processing tool mold is connected to the lower body; conveying the blank from the first post-processing tool to a second post-processing tool; 46. ​​The method of any one of clauses 44-45, further comprising the step of providing a downward and upward pressing stroke of the moving upper body against the fixed lower body.

[0197] While various examples have been disclosed herein, other alternatives, modifications, uses and / or equivalents are possible. Furthermore, any possible combination of the examples described is also covered. Thus, the scope of the disclosure is not limited to the specific examples, but is defined only by a fair reading of the claims that follow.

Claims

1. A press device for manufacturing hot-formed structural members, comprising a fixed lower body, a moving upper body, and a mechanism configured to provide a pressing process in which the moving upper body moves upwards and downwards relative to the fixed lower body, The press device is a cooling tool configured to cool the preheated blank; a press tool positioned downstream from the cooling tool and configured to elongate the blank; a blank conveying mechanism that conveys the blank from the cooling tool to the press tool; Equipped with the cooling tool comprises an upper gas cooling tool connected to the moving upper body and / or a lower gas cooling tool connected to the fixed lower body, the upper gas cooling tool and / or the lower gas cooling tool configured to provide compressed cooling gas to impinge on the blank; The press tool is a press apparatus comprising an upper press die connected to a movable upper body and a lower press die connected to a fixed lower body.

2. The press apparatus of claim 1 further comprising a lower gas cooled tool connected to the stationary lower body.

3. The pressing apparatus of claim 1 further comprising an upper gas cooling tool connected to the moving upper body with one or more upper biasing elements, the upper biasing elements biasing the upper gas cooling elements away from the moving upper body.

4. The cooling tool comprises an upper gas cooling tool connected to the moving upper body and a lower gas cooling tool connected to the fixed lower body; 2. The press apparatus of claim 1, wherein an upper gas cooling tool is connected to the moving upper body together with one or more upper biasing elements that bias the upper gas cooling element away from the moving upper body, and / or a lower gas cooling tool is connected to the fixed lower body together with one or more lower biasing elements that bias the lower gas cooling element away from the fixed lower body.

5. 5. The press apparatus of claim 3 or 4, wherein at a lowest point of the press cycle the upper gas cooled tool is positioned at a first predetermined distance relative to the blank and the lower gas cooled tool is positioned at a second predetermined distance relative to the blank, optionally the first predetermined distance being equal to the second predetermined distance.

6. 6. A pressing apparatus according to claim 3, wherein the cooling tool is provided with a stopper for maintaining a minimum distance between the upper gas cooling tool and the blank.

7. 7. The pressing apparatus of claim 6, wherein a stop is provided on the upper gas-cooled tool, the stop contacting the lower gas-cooled tool to generate a force opposite to the biasing element.

8. A pressing apparatus according to any one of claims 3 to 7, wherein the biasing element comprises one or more springs.

9. 9. The press apparatus according to claim 1, wherein the upper gas-cooled tool and / or the lower gas-cooled tool comprises a plurality of slots connected to a reservoir of compressed gas, and the system comprises a control unit for controlling the flow of gas from the reservoir through the slots.

10. 10. The pressing apparatus of claim 9, wherein the slot is oriented substantially perpendicular to the blank.

11. 11. The press device according to claim 1, wherein the upper press die and / or the lower press die of the press tool are provided with channels for conducting a cooling liquid or cooling air.

12. 12. A press apparatus according to any one of the preceding claims, which is a mechanical press or a servo-mechanical press.

13. The press tool further includes a first post-processing tool for performing a first post-processing, the first post-processing tool being disposed downstream of the press tool and including upper and lower first post-processing tool fittings; The upper first post-processing tool fitting is connected to the movable upper body, and the lower first post-processing tool fitting is connected to the fixed lower body; 13. The press apparatus of claim 1, wherein the blank transport device is further configured to transport the blank from the press tool to a first post-processing tool.

14. 1. A method for hot forming a blank, comprising the steps of: Providing a pressing apparatus according to any one of claims 1 to 13; Providing a blank made of zinc coated ultra high strength steel (UHSS); Heating the blank; placing the blank in a cooling tool; cooling the blank while subjecting the moving upper body to a downward pressing stroke against the fixed lower body; performing an upward pressing process of the moving upper body against the fixed lower body; Positioning the blank in a press tool; - stretching the blank by performing downward and upward pressing of the moving upper body against the fixed lower body; A method comprising:

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