Heat treatment of components

Abstract

The invention relates to a device (1) for the heat treatment of a component (2), which can be arranged in the device (1) in a component plane (E) spanned by a first direction (x) and a second direction (y) perpendicular to the first direction, the device comprising: a heating section (3) having a heating device (5) for heating a first region (7) of the component (2), a cooling section (4) having a cooling device (6) for cooling a second region (8) of the component (2); wherein the cooling section (4) is located downstream of the heating section (3) in the second direction (y); wherein the cooling device (6) has a nozzle (9) for discharging a cooling fluid (10) onto the component (2); wherein the nozzle (9) is oriented so that it descends in the second direction (y); and wherein the nozzle (9) has a fluid channel (15) with a nozzle opening (16). By means of the device (1), components (2), more particularly steel components for motor vehicles, can be heat treated individually in different regions, wherein there can be a specifically defined demarcation between the regions (7, 8). For this purpose, the nozzle (9) is directed away from the heating section (3) and has a fluid channel (15) with a nozzle opening (16).

Description

[0001] The present invention relates to an apparatus for the heat treatment of components, more particularly steel components for motor vehicles.

[0002] In the automotive industry, it is known to selectively harden steel components by heat treatment. To this end, steel components (e.g., B-pillars) are heat treated in a region-specific manner. The resulting hardness varies depending on the region, which is beneficial for the crash performance of these components.

[0003] Various methods are known for treating steel components in a region-specific manner. All known methods have in common the inadequate demarcation between the individual temperature ranges. This makes it particularly difficult to simulate the behavior of components treated in this manner in the event of an accident.

[0004] Starting from the aforementioned prior art, the object of the present invention is to provide a device for the heat treatment of components, by means of which (multiple) regions of the component can be heat treated in a specifically defined manner in such a way that the regions of the component are separated from one another.

[0005] This object is achieved by a device according to the independent claim. Advantageous embodiments of the device are specified in the dependent claims. The features presented in the claims and the description can be combined with one another in any technically meaningful manner.

[0006] According to the present invention, an apparatus for heat treatment of components is provided. The components can be arranged in an assembly plane in the apparatus, the assembly plane being spanned by a first direction and a second direction perpendicular to the first direction.

[0007] Equipment includes:

[0008] a heating portion having heating means for heating the first region of the component,

[0009] - a cooling section having a cooling device for cooling a second area of ​​the component; wherein the cooling section is located downstream of the heating section in the second direction; wherein the cooling device has a nozzle for discharging a cooling fluid onto the component; wherein the nozzle is oriented so that it descends in the second direction; and wherein the nozzle has a fluid channel having a nozzle opening.

[0010] The device is described using a coordinate system having a first, second, and third perpendicular direction. The first and second directions together define a plane, referred to as the component plane. The device does not include a component but is intended and configured to receive a component. Therefore, a component can be inserted into the device such that it lies within the component plane. Extension of the component in the third direction is negligible.

[0011] This system is particularly suitable for heat treating steel components, particularly those used in motor vehicles. For example, a B-pillar could be such a component. This system can also be referred to as a temperature control station. Preferably, the components treated in the system are removed from the system and subsequently hardened. In this case, the system is part of an arrangement with a press located downstream of the system.

[0012] In an apparatus, components can be heat treated in a region-specific manner. To this end, the apparatus includes a heating section and a cooling section. In the second direction, the cooling section is located downstream of the heating section. Thus, when viewed along the second direction, the cooling section and the heating section are located behind each other. The second direction runs from the heating section to the cooling section. Preferably, the cooling section and the heating section are adjacent to each other.

[0013] A first region of the component can be heated in the heating section. A second region of the component can be cooled in the cooling section. This can occur simultaneously. The component can be inserted into the apparatus, preferably in a first direction or opposite to the first direction. The component can be heat treated in the apparatus. During the heat treatment, the component is preferably stationary. After the heat treatment, the component can be removed from the apparatus, preferably in the first direction or opposite to the first direction. However, it should be noted that the first direction is generally defined independently of the direction of movement of the component. If the component moves in the first direction, the direction of movement of the component is consistent with the first direction. However, the component can also optionally move in any other direction.

[0014] The first and second regions of the component are distinct from one another. Preferably, the component is divided into the first and second regions, i.e., has no further regions. However, the component may optionally have further regions in addition to the first and second regions. In each case, the first and second regions preferably, but not necessarily, form a continuous region. The first and second regions of the component are defined in the component plane.

[0015] Due to the different heat treatments, the first area becomes harder than the second during the subsequent hardening process. For example, this can be used to make the flange of the B-pillar (the second area) softer than the rest of the B-pillar (the first area). This not only allows for targeted adjustments to crash performance, but also facilitates B-pillar assembly. In particular, riveting and press-fitting are now possible. During welding, the risk of cracking in the heat-affected zone of the weld is reduced.

[0016] Cooling in the cooling section is preferably performed by applying a cooling fluid to the components in the second region, the cooling fluid being discharged from a nozzle. The cooling fluid is preferably gaseous. Compressed air or nitrogen is preferably used as the cooling fluid. The cooling fluid is preferably discharged at a pressure in the range of 2 to 4 bar. The nozzle preferably does not contact the components. Consequently, the device is particularly tolerant to positioning errors and deformations of the components due to temperature and / or inherent stresses.

[0017] Preferably, the nozzle is designed as a slit nozzle. Preferably, the nozzle opening, in particular the fluid channel upstream thereof, has a flow cross-section with an aspect ratio of at least 1 to 5. This means that the extension of the flow cross-section in one direction (preferably along the first direction) is at least 5 times greater than the extension of the flow cross-section perpendicular to this direction. Preferably, the nozzle is oriented so that the longer side of the nozzle opening is oriented parallel to the component plane. The slit nozzle allows for a particularly uniform flow of the cooling fluid. For this purpose, it is particularly preferred if the nozzle opening has sharp edges.

[0018] The nozzle is oriented so that it descends in the second direction. Thus, when viewed from the heating section toward the cooling section, the nozzle is tilted downward in the direction of the component plane. If the component is positioned within the apparatus, the nozzle is oriented obliquely in the second direction toward the component. The nozzle's orientation is related to the direction in which the cooling fluid is discharged from the nozzle. If discharged from the nozzle as a planar jet, the direction is defined by the center of gravity of the planar jet (i.e., along the axis of the planar jet).

[0019] Due to the orientation of the nozzle, the cooling fluid is discharged in a direction away from the component located in the device and away from the heating part. After the cooling fluid impacts the component, the cooling fluid flows along the component surface in a second direction. Therefore, the cooling fluid has momentum, and the momentum has a component pointing in the second direction and therefore away from the heating part. Therefore, the second area of ​​the component can be cooled, wherein particularly little cooling fluid enters the heating part. In this regard, a particularly defined delimitation of the thermal treatment of the first area and the second area can be achieved. Due to heat conduction within the component, the width of the transition zone can be reduced to an unavoidable minimum value. The embodiment can be referred to as an "aerodynamic seal" between the heating part and the cooling part.

[0020] Tests have shown that the delimitation between the first and second regions can be further strengthened by a nozzle having a fluid channel with a straight section upstream of the nozzle, which is therefore preferred. Therefore, the fluid channel is preferably formed as a straight line at least in the section adjacent to the nozzle opening. In this case, the cooling fluid flows along a straight flow path before exiting the nozzle opening. This achieves a particularly uniform jet formation. This means that particularly little cooling fluid reaches the heated part. Thus, a particularly defined delimitation of the (multiple) regions of the component can be achieved. In addition, the second region can be cooled particularly uniformly by the uniform jet formation. As an alternative to the straight section upstream of the nozzle opening, a curved section can also be arranged upstream of the nozzle opening. Depending on the component geometry, this may be a workaround.

[0021] It has been found that a particularly uniform jet formation is achieved in particular in preferred embodiments of the device in which the fluid channel has a straight section which is located upstream of the nozzle opening and has a length of at least 5 mm.

[0022] The length of the straight portion is measured along the fluid channel. Preferably, the length of the straight portion of the fluid channel is in the range of 5 mm and 40 mm, in particular in the range of 10 to 15 mm.

[0023] In another preferred embodiment of the device, the nozzle is at least partially lowered in the second direction facing the outer wall of the heating portion.

[0024] The cooling fluid has a very high exit velocity at the nozzle opening. Due to the laws of physics, a strong negative pressure is generated, which leads to the entrainment of large amounts of air from the surroundings of the nozzle opening. The total mass flow rate of the movement can be up to 100 times higher than the mass flow rate of the cooling fluid. This allows the component to be cooled particularly effectively. In the present embodiment, this is particularly true because the flow of the entrained air from the surroundings of the nozzle opening is directed in a targeted manner. To this end, the outer wall of the nozzle facing the heating part is used as a guide surface. The outer wall of the nozzle is at least partially descending in the second direction. Due to this descent, air is entrained from the surroundings of the nozzle opening, so that the entrained air flows onto the component and away from the heating part. As a result, the entrained air flow, like the cooling fluid itself, ensures that particularly little entrained air reaches the heating part. This also helps to define the component's region(s) in a particularly defined manner.

[0025] Preferably, the outer wall of the nozzle has no sharp edges. Therefore, the air can flow around the nozzle with as little resistance as possible, so that the air can reach the nozzle opening as unhindered as possible.

[0026] In another preferred embodiment, the apparatus further comprises a partition wall between the heating portion and the cooling portion, wherein an outer wall of the nozzle facing the heating portion is spaced apart from the partition wall in the second direction.

[0027] The dividing wall can also be referred to as a partition. It can be used to separate the first and second areas from each other in a specifically defined manner. Preferably, the dividing wall is oriented parallel to the outer wall of the nozzle facing the heating portion. Preferably, the dividing wall extends directly above the component, so that the remaining gap between the component and the dividing wall is as small as possible. To accommodate components of varying thickness within the system, the dividing wall is preferably designed so that the gap has an adjustable extension.

[0028] The outer wall of nozzle 9, facing the heating portion, is spaced apart from the partition wall in the second direction. Consequently, a gap is formed between the partition wall and the nozzle, through which air and cooling fluid entrained at the nozzle opening can flow. This air flow allows the cooling fluid at the nozzle opening to entrain a particularly large amount of air, thereby enabling particularly effective cooling of the second region of the component.

[0029] The partition wall is preferably part of a nozzle box, which includes a cover plate adjacent to the partition wall. In a preferred embodiment, the cover plate is included in the device and is arranged above the nozzles in the cooling section. Preferably, the partition wall and the cover plate abut each other and may even be formed integrally with each other.

[0030] Preferably, the nozzle box formed by the partition wall and the cover plate delimits at least part of the cooling section. The second area of ​​the component can be cooled particularly effectively by the nozzle box. In particular, the diffusion of the cooling fluid can be limited by the nozzle box, thereby keeping cooling fluid consumption low.

[0031] In another preferred embodiment, the apparatus further comprises a guide plate, which is arranged in the cooling section, on a side of the nozzle facing away from the heating section, and parallel to the assembly plane.

[0032] When viewed in the second direction, the sequence of this embodiment is as follows: a heating section, an optional partition wall, a cooling section having a nozzle and a guide plate in this order.

[0033] The guide plate is preferably arranged at a distance from the nozzle so that air can flow between the nozzle and the guide plate. The cooling fluid exiting the nozzle opening can entrain this air. This occurs in addition to the air flowing along the outer wall of the nozzle facing the heating portion and is also entrained by the cooling fluid exiting the nozzle opening.

[0034] The guide plate is oriented parallel to the plane of the assembly, i.e., it lies in a plane spanned by the first and second directions. In this plane, the guide plate preferably extends until it substantially completely covers the second region of the assembly. The guide plate preferably extends in the first direction in a range of 10 to 200 mm. The guide plate preferably extends in the second direction in a range of 50 to 250 mm.

[0035] The guide plate is arranged above the plane of the component in the third direction, that is, on the side of the component where the nozzle is also located. The guide plate and the component form a channel through which the cooling fluid and air entrained by the cooling fluid can flow through the component. This channel should be distinguished from the fluid channel within the nozzle. The guide plate prevents undesirable turbulence, which can occur particularly if the component has a large extension in the second direction. Therefore, the guide plate makes the device particularly suitable for large components.

[0036] In a further preferred embodiment of the device, the edge of the guide plate facing the nozzle is rounded.

[0037] Rounded edges can be obtained in particular by bending the edges of thin guide plates or by machining the edges of thick guide plates so that the initially sharp edges are broken.

[0038] The rounded edges of the guide plates improve the flow of the cooling fluid and the air entrained by it. In particular, turbulence that can occur around sharp edges can be reduced or even prevented. Furthermore, the rounded edges improve stability, particularly in the case of thin guide plates.

[0039] In a further preferred embodiment of the device, at least one spacing pin is arranged on the guide plate in order to hold the assembly at a distance from the guide plate.

[0040] In the channel formed by the guide plate and the component, the flow rate remains approximately constant. Consequently, negative pressure in the channel results in buoyancy. This allows thin and / or large components to be lifted. In this embodiment, this is limited by the spacer pins. Preferably, at least one spacer pin is oriented along a third direction. Preferably, at least one spacer pin extends from the guide plate in a direction opposite to the third direction, in particular to a position that, during normal operation, is just above the surface of the component.

[0041] In another preferred embodiment of the device, the fluid channel has a uniform width in the range of 0.1 to 3 mm perpendicular to the first direction in a straight portion upstream of the nozzle opening.

[0042] The width of the fluid channel perpendicular to the first direction is defined as the minimum distance between two opposing side walls of the fluid channel when viewed in a plane perpendicular to the first direction. In this embodiment, this width is constant throughout the entire straight portion and is in the range of 0.1 to 3 mm. The flow cross-section of the cooling fluid is determined by the width thus defined and the extension of the fluid channel along the first direction. Preferably, the fluid channel extends in the range of 10 to 300 mm, particularly 60 to 100 mm, along the first direction. This allows sufficient cooling fluid to be supplied to the second region to cool the second region.

[0043] If the width of the fluid channel is within the specified range, a sharply delimited flow of the cooling fluid over the component surface can be achieved. Furthermore, air from the area surrounding the nozzle opening can be entrained particularly effectively. Overall, the width of the fluid channel thus results in particularly effective cooling of the second region of the component.

[0044] In another preferred embodiment of the device, the nozzle is oriented at a first angle in the range of 15° to 60° to the component plane, and / or the outer wall of the nozzle facing the heating part at least partially encloses a second angle in the range of 15° to 60° to the component plane.

[0045] The first angle is defined between the component plane and the direction in which the cooling fluid is discharged from the nozzle. If this occurs in the form of a flat jet, the first angle is defined between the centerline of the flat jet (ie the axis of the flat jet) and the component plane.

[0046] Preferably, a planar portion of the outer wall of the nozzle facing the heating section encloses a second angle in the range of 15° to 60° with the component plane. Preferably, the planar portion extends to the nozzle opening. As a result of this embodiment, air entrained by the cooling fluid flows along a straight flow path before exiting the outer wall of the nozzle. This allows the air to reach the component surface in a particularly uniform manner. This makes it possible to prevent the cooling fluid and / or entrained air from entering the heating section. Furthermore, the second region can thus be cooled in a particularly uniform manner. To this end, it is particularly preferred that the outer wall of the nozzle facing the heating section is formed parallel to the fluid channel on the outside of the straight section of the fluid channel. This means that the straight section of the fluid channel is bounded by an outer wall of constant thickness on its side facing the heating section. Therefore, the cooling fluid in the fluid channel and the air entrained by the cooling fluid flow along the outer wall of the nozzle via mutually parallel straight flow paths before the cooling fluid and air exit the nozzle. This results in a particularly uniform flow.

[0047] Preferably, the nozzle is oriented at a first angle in the range of 15° to 60° with respect to the plane of the assembly, and an outer wall of the nozzle facing the heating portion at least partially encloses a second angle in the range of 15° to 60° with respect to the plane of the assembly. Particularly preferably, the first angle and the second angle are of equal magnitude. Preferably, the first angle and / or the second angle are both 45°.

[0048] The invention is explained in more detail below with reference to the accompanying drawings. The drawings show particularly preferred embodiments, but the invention is not limited thereto. The drawings and the proportions shown therein are merely schematic. In the drawings:

[0049] Figure 1 : shows a cross-sectional view of an apparatus for heat treatment of components according to the present invention,

[0050] Figure 2 : Shows Figure 1 An enlarged view of the nozzle of the device, and

[0051] Figure 3 : Shows Figure 1 The flow cross section of the nozzle of the device.

[0052] Figure 1 A device 1 for heat treating a component 2 is shown. The device 1 is described using a coordinate system having a first direction x, a second direction y, and a third direction z that are perpendicular to each other in pairs. The first direction x and the second direction y together define a plane, which is referred to as the component plane E. The component 2 lies in the component plane E (wherein the extension of the component 2 in the third direction z is not taken into account).

[0053] The device 1 comprises a heating section 3 having a heating device 5 for heating a first region 7 of the component 2 and a cooling section 4 having a cooling device 6 for cooling a second region 8 of the component 2. In the second direction y, the cooling section 4 is located downstream of the heating section 3, i.e., in the figure, the cooling section 4 is arranged to the right of the heating section 3.

[0054] The cooling device 6 has a nozzle 9 for discharging a cooling fluid 10 onto the component 2. The cooling fluid 10 is indicated by an arrow. The cooling fluid can be supplied to the nozzle 9 via a connection 18.

[0055] In the second direction y, the nozzle 9 is oriented so that it descends. This means that the nozzle 9 discharges the cooling fluid 10 to the Figure 1 The nozzle 9 has a fluid channel 15 with a nozzle opening 16 and a straight portion 17 upstream of the nozzle opening. Furthermore, the outer wall 11 of the nozzle 9, which faces the heating portion 3, also descends in the second direction y. In the embodiment shown, the outer wall 11 is formed parallel to the straight portion 17 of the fluid channel 15.

[0056] The apparatus 1 further comprises a nozzle box 22 having a partition wall 19 between the heating section 3 and the cooling section 4 and a cover plate 20 arranged in the cooling section 4 above the nozzle 9. The outer wall 11 of the nozzle 9 facing the heating section 3 is spaced apart from the partition wall 19 in the second direction y. The partition wall 19 is oriented parallel to the outer wall 11.

[0057] The device 1 further comprises a guide plate 12 arranged in the cooling section 4 on the side of the nozzle 9 facing away from the heating section 3 and parallel to the assembly plane E. The edge 13 of the guide plate 12 facing the nozzle 9 is rounded. Figure 1In the illustration of , it is the left edge of the guide plate 13. It is bent downwards and is therefore rounded. A plurality of spacing pins 14 are arranged on the guide plate 12 so as to keep the assembly 2 at a certain distance from the guide plate 12.

[0058] The apparatus 1 further comprises a thermal insulation 21 below the heating section 3 and above the nozzle box 22 .

[0059] Figure 2 Shown Figure 1 1 . The nozzle 9 is part of the cooling device 6. In particular, the straight section 17 of the fluid channel 15 can be seen. In addition, the outer wall 11 facing the heating part 3 (not shown here) can be seen. The length l of the straight section 17 of the fluid channel 15 is also shown. g . It is at least 5 mm. In addition, the width b of the fluid channel 15 perpendicular to the first direction x is shown g . It has a uniform value in the range of 0.1 to 3 mm. Furthermore, a first angle α is shown, at which the nozzle 9 is aligned with the assembly plane E. A second angle β is also shown, which encloses the outer wall 11 of the nozzle 9 facing the heating part 3 and the assembly plane E. In the embodiment shown, the first and second angles are equal and range from 15° to 60°.

[0060] Figure 3 Shown Figure 1 Flow cross section of the nozzle of the device of FIG. The nozzle opening 16 is shown, the width bg of which corresponds to the width of the straight section 17 of the fluid channel 15. In addition, the expansion a of the nozzle opening 16 in the first direction x is shown.

[0061] By means of the device 1, more specifically the component 2, steel components for motor vehicles can be individually heat treated in different zones, with a specifically defined demarcation between the zones 7 and 8. For this purpose, the nozzle 9 is directed away from the heating section 3 and has a fluid channel 15 with a nozzle opening 16.

[0062] Reference designator list

[0063] 1 Equipment

[0064] 2 Components

[0065] 3 Heating part

[0066] 4 Cooling section

[0067] 5 Heating device

[0068] 6 Cooling device

[0069] 7 First Area

[0070] 8 Second Area

[0071] 9 Nozzles

[0072] 10 Cooling fluid

[0073] 11 outer wall

[0074] 12 guide plate

[0075] 13 Edge

[0076] 14 Spacer pins

[0077] 15 fluid channels

[0078] 16 Nozzle opening

[0079] 17 Straight line

[0080] 18 Connectors

[0081] 19 partition wall

[0082] 20 Cover

[0083] 21 Thermal insulation

[0084] 22 nozzle box

[0085] x first direction

[0086] y Second direction

[0087] z third direction

[0088] E Component plane

[0089] l g Length of the straight part

[0090] b g Width of the straight line

[0091] a Expansion of the nozzle opening

[0092] α first angle

[0093] β Second angle

Claims

1. A device (1) for the heat treatment of a component (2), arranged in a component plane (E) in the device (1), the component plane being spanned by a first direction (x) and a second direction (y) perpendicular to the first direction, the device comprising a heating section (3) having a heating device (5) for heating a first region (7) of the component (2), a cooling section (4) having a cooling device (6) for cooling a second region (8) of the component (2), wherein the cooling section (4) is located downstream of the heating section (3) in the second direction (y), wherein the cooling device (6) has a nozzle (9) for discharging a cooling fluid (10) onto the component (2), wherein the nozzle (9) is oriented such that it descends in the second direction (y); and wherein the nozzle (9) has a fluid channel (15) with a nozzle opening (16), and - a partition wall (19) between the heating section (3) and the cooling section (4), wherein the outer wall (11) of the nozzle (9) facing the heating section (3) is spaced apart from the partition wall (19) in the second direction (y), wherein A gap is formed between the partition wall (19) and the nozzle (9), through which air entrained by the cooling fluid at the nozzle opening can flow.

2. The device (1) according to claim 1, characterized in that The fluid channel (15) has a straight portion (17) upstream of the nozzle opening (16) and having a length (l) of at least 5 mm. g ).

3. The device (1) according to 1 or 2, characterized in that An outer wall (11) of the nozzle (9) facing the heating portion (3) is at least partially lowered in the second direction (y).

4. The device (1) according to claim 3, characterized in that It also includes a cover plate (20), which is arranged in the cooling section (4) above the nozzle (9).

5. The device (1) according to claim 4, characterized in that It also comprises a guide plate (12), which is arranged in the cooling section (4) on the side of the nozzle (9) facing away from the heating section (3) and parallel to the assembly plane (E).

6. The device (1) according to claim 5, characterized in that The edge (13) of the guide plate (12) facing the nozzle (9) is rounded.

7. The device (1) according to claim 6, characterized in that At least one spacing pin (14) is arranged on the guide plate (12) in order to keep the assembly (2) at a distance from the guide plate (12).

8. The device (1) according to claim 7, characterized in that The fluid channel (15) has a uniform width (b) in the range of 0.1 to 3 mm perpendicular to the first direction (x) in a straight portion (17) upstream of the nozzle opening (16). g ).

9. The device (1) according to claim 8, characterized in that The nozzle (9) is oriented at a first angle (α) in the range of 15° to 60° to the component plane (E), and / or wherein, The outer wall (11) of the nozzle (9) facing the heating portion (3) at least partially encloses a second angle (β) in the range of 15° to 60° with the assembly plane (E).

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