EP2014777B1 - Method and device for thermal treatment of metal sheet - Google Patents

Description

The invention relates to a method for the thermal treatment of at least one metal body according to the preamble of claim 1.

As state of the art for the thermal treatment of metal bodies, heat ovens are known. In this case, the metal body is heated in a heating furnace, wherein the thermal treatment takes place. In such methods, the desired parameter changes in the material can be controlled and controlled only conditionally, since the temporal and thermal conditions can not be precisely defined and reproduced safely. This can lead to uncontrollable changes in the properties of the sheet material.

As a further prior art, the inductive heating and the heating by laser are known. Both methods allow a local thermal treatment on a defined partial surface of a metal body. Due to the rapid local heating of the material, disadvantages such as distortion of the metal body arise and thus dimensional deviations after heating, difficult control and control of the temperature in the heating field due to uneven warpage due to distortion between heat source and sheet, uneven temperature distribution on the heating zone, the inhomogeneous material properties causes and metal bodies with a zinc layer partial or total destruction of the zinc layer evaporation.

DE 10 2005 045340 A1 describes a burn-in heat treatment for an aluminum sheet, wherein a first contact plate is brought into contact with a first surface portion of a metal body and a second contact plate with a second surface portion of the metal body. In this case, the contact plates are formed according to the contour of the surface portions of the metal body and extend in the state of contacting with the metal body parallel to each other. In this case, the contact plates have a higher temperature relative to the metal body during the contacting of the metal body. The method described therein thus allows heating of a metal body to a certain heat treatment temperature. Further influence or control of the temperature of the metal body after it has been brought to the heat treatment temperature does not occur.

WO 2007/013279 A describes a method for heating a metal body, wherein a metal part between two contact plates is inserted and heated.

DE 103 41 867 A1 describes a method and apparatus for producing a hardened sheet metal profile, wherein the sheet metal profile is heated in an oven to Austenitisierungstemperatur, and then transferred to a cooled tool, wherein a thermal contact between the tool and sheet metal profile.

The invention has for its object to provide a comparison with the prior art improved, in particular a low distortion and / or improved in terms of temperature control process for the thermal treatment of metal bodies.

This object is achieved by a method having the features of patent claim 1. Advantageous embodiments of the method are realized in the dependent claims 2-11.

The temperature of the metal body compensates during contacting the temperature of the contact plate. This leads to a thermal treatment of the metal body. It is thus possible both heating and cooling of the metal body by contact plates. In addition, the temperature-induced distortion is minimized by the uniform temperature change and the surface pressure through the contact plates.

By means of the method according to the invention, it is possible to introduce a precisely defined temperature into the regions of the metal body which are in contact with the contact surfaces. As a result, the material properties which arise as a result of the thermal treatment can be adjusted very precisely and homogeneously.

The method according to the invention can be used variably. In particular, the temperature which the contact plate has or on which the metal body is brought, as well as the period of time for which the contact between contact plates and metal body, can be chosen almost arbitrarily. It is thus possible to variably adapt the method according to the invention to the desired parameters of the thermal treatment and to the material to be treated. In particular, both thermal treatments are possible, which lead to a softening of the material as well as thermal treatments that lead to a solidification.

The contact between metal body and contact plates may be formed such that the contact plates and the metal body touch directly. However, it may also be an intermediate layer, such as a contact agent, which improves the temperature balance between the contact plate and metal body, be present.

It can be detected simultaneously between the contact plates both only a metal body and a plurality of metal body.

The surface portions communicating with the contact plates may extend over or cover completely large portions of the metal body as well as forming only small, localized areas of the metal body. If only locally limited areas are connected to the contact plates, a local thermal treatment of the metal body can be carried out.

In an advantageous embodiment, the metal body is formed as a sheet metal or sheet metal part and the at least one first surface portion is located on the upper side of the sheet metal and the at least one second surface portion is located on the underside of the sheet metal. Such a method leads to a very homogeneous temperature distribution over the entire thickness range of the metal body. This has the advantage that can be set by the thermal treatment very defined material properties that are present homogeneously over the entire surface section.

According to a particularly advantageous embodiment, as a metal body is at least partially with a zinc layer provided sheet metal or sheet metal parts used. In particular, high-strength, galvanized sheets and sheet metal parts can be used from the body shop. In such metal bodies with a zinc layer, the contact between metal body and contact plate prevents the damage or destruction of the zinc layer.

In a further advantageous embodiment, a metal body is used, which is formed in a later step, and the at least one first and second surface portion are in or near the area to be reformed later. This makes it possible to perform the thermal treatment locally in the area that affects the feasibility of a forming process. It can be generated by the thermal treatment locally material properties that favor the subsequent forming process. In particular, such a local softening of this region of the metal body is possible.

According to a further embodiment, the contact plates are pressed onto the metal body. This has the advantage that a contact between contact plates and metal body is ensured particularly secure. In addition, thereby minimizing the delays is particularly effective possible.

In a further embodiment, the temperature of the at least one contact plate with elevated or lowered temperature before and / or during the contacting of the metal body with the contact plates is controlled by a temperature control device. Thus, it is possible the temperature of the contact plate and thus also the temperature of the metal body during the entire thermal treatment control or regulate. In particular, such a control device both preheat prior to contacting the contact plates, heat the contact plates during contact, keep a desired temperature during contacting constant or provide for a controlled lowering of the temperature in the course of contacting. However, the control device can also provide for a defined cooling of the contact plates.

According to a further embodiment, in a further method step, after the desired temperature has been applied to the metal body for the thermal treatment, at least one contact plate is removed. If all the contact plates removed, this leads to a free alignment of the temperature of the metal body to the ambient temperature. If a contact plate is removed, this leads to a partial free alignment of the temperature of the metal body. In areas of the metal body, which are still associated with a contact plate, the temperature of the metal body, however, is influenced by the contact plate. This makes it possible to influence the formation of the temperature profile of the metal body by removing one or more contact plates.

In a further embodiment, the first contact plates and / or the second contact plates are interconnected with a flexible transition element. This allows the individual contact plates to adapt flexibly to different geometries of the basic body.

According to the invention, the metal body is heated in a first method step and brought into contact with at least one contact plate in a subsequent method step. In this case, the contact plate has a relation to the metal body lower temperature. Due to the lower temperature of the contact plates, the metal body is cooled after heating. This cooling is well controlled due to the contact plates in terms of temperature control.

The heating of the metal body takes place by contact with contact plates, which have a higher temperature than the metal body done.

The same contact plates are brought in the subsequent process step to a temperature lower than that of the metal body and thus serve for cooling. But it can also be used for heating other contact plates than for cooling.

Furthermore, the metal body is brought into contact with at least one contact plates in a first method step. In this case, the contact plate has a relation to the metal body higher temperature. Due to the higher temperature of the contact plates, the metal body is heated. This heating due to the contact plates in terms of temperature control is well controlled. In addition, will minimized due to the contacting of the warp caused by warpage.

In this case, the at least one contact plate, which has an elevated temperature relative to the metal body, is preferably heated to this temperature by an energy source. This can be done, for example, inductively or conductively.

The heating can take place either before the contact with the metal body or during the contacting.

It can be heated both only one contact plate as well as several contact plates.

The contact plates can also be brought into mutual contact with one another before the contact with the metal body. It can then be heated a contact plate. The heat then transfers to the others with these contact plates in contact. Subsequently, the contact plates can be separated from each other and brought into contact with the metal body.

The contact plates can both be made of the same material as well as of different materials. Preferably, contact plates that are heated, made of a metallic material, such as steel.

Contact plates that are not heated may preferably be made of both metallic and non-metallic materials. In a particularly advantageous manner, contact plates, the not heated, made of an insulating material. This has the advantage that the heat loss is reduced.

The contact plates may have an insulating layer. Also, the heat loss can be reduced thereby.

In a further embodiment, in particular in a further method step, at least one contact plate is cooled. By actively cooling the contact plates, the temperature of the metal body can be precisely controlled. In particular, the cooling rate of the metal body can thereby be set precisely. For example, solidification of the material in the area of the cooled contact plates is possible.

The cooled contact plates may also have cooling channels. This allows the passage of liquid or gaseous coolants through the contact plates, which leads to a particularly accurate cooling.

Fig.1 1

eine schematische Schnittdarstellung einer Ausführungsform des erfindungsgemäßen Verfahrens,

Fig. 2

eine schematische Schnittdarstellung einer weiteren Ausführungsform des erfindungsgemäßen Verfahrens,

Fig. 3a

eine schematische Schnittdarstellung eines ersten Verfahrensschrittes zu einer Temperierung der Kontaktplatten,

Fig. 3b

eine schematische Schnittdarstellung eines zweiten Verfahrensschrittes zu einer Anwendung der Kontaktplatten,

Fig. 3c

eine schematische Schnittdarstellung eines dritten Verfahrensschrittes zu einer Anwendung der Kontaktplatten,

Fig. 4

eine schematische Schnittdarstellung einer weiteren Ausführungsform des erfindungsgemäßen Verfahrens sowie

Fig. 5

eine schematische Schnittdarstellung eines weiteren Verfahrensschrittes des erfindungsgemäßen Verfahrens.

Fig. 6

eine schematische Schnittdarstellung einer weiteren Ausführungsform des erfindungsgemäßen Verfahrens

Fig. 7

eine schematische Schnittdarstellung einer weiteren Ausführungsform des erfindungsgemäßen Verfahrens

Fig. 8

eine schematische Schnittdarstellung einer weiteren Ausführungsform des erfindungsgemäßen Verfahrens

The invention is further explained by means of embodiments in the drawing figures. Show it:

Fig.1 1

a schematic sectional view of an embodiment of the method according to the invention,

Fig. 2

a schematic sectional view of another embodiment of the method according to the invention,

Fig. 3a

1 is a schematic sectional view of a first method step for tempering the contact plates;

Fig. 3b

FIG. 2 is a schematic sectional view of a second method step for using the contact plates. FIG.

Fig. 3c

1 is a schematic sectional view of a third method step for an application of the contact plates;

Fig. 4

a schematic sectional view of another embodiment of the method according to the invention and

Fig. 5

a schematic sectional view of a further process step of the method according to the invention.

Fig. 6

a schematic sectional view of another embodiment of the method according to the invention

Fig. 7

a schematic sectional view of another embodiment of the method according to the invention

Fig. 8

a schematic sectional view of another embodiment of the method according to the invention

Fig. 1 shows a schematic sectional view of an embodiment of the method according to the invention. The metal body 1 has been brought by the displacement of the first contact plate 2 in the direction 4 with this in contact. A first surface portion 6 of the metal body 1 communicates with the first contact plate 2.

In addition, the metal body 1 has been brought into contact with the second contact plate 3. A second surface portion 7 is in communication with the second contact plate 3.

In this case, the contact plates 2, 3 are formed flat in accordance with the contour of the surface sections 6, 7 of the metal body 1 and are arranged running parallel to one another in the state of contacting with the metal body 1.

For contacting the contact plates 2, 3 with the metal body 1, either only one contact plate or a plurality of contact plates can be displaceable.

The contact can be designed such that the first contact plate 2 and the second contact plate 3 simultaneously with the Metal body 1 are brought into contact. However, it is also possible first to bring a contact plate 2 into contact with the metal body 1 and to add a second contact plate 3 only later in time.

The second contact plate 3 is or was brought by an energy source 5 to a relative to the metal body 1 increased or decreased temperature. Energy source 5 is understood below to mean any device that can be used for cooling or heating objects.

The contact plates 2, 3 are arranged running parallel to one another. The second contact plate 3 has an insulation layer 8. By this insulating layer 8, the heat or cooling loss can be reduced.

During the contacting of the contact plates 2, 3 with the metal body 1, the temperature of the metal body 1 can be kept constant. However, it is also possible to vary the temperature of the metal body in the course of contacting by the defined change in the temperatures of the contact plates. Thus, a very variable adaptation of the temperature-time curve is possible.

The temperature profile along a contact plate 2, 3 can be designed such that an almost constant temperature is established over the entire contact plate 2, 3. However, the contact plate 2, 3 can also be heated or cooled in such a way that regions with different temperatures form within the contact plate 2, 3. Thus, it becomes possible in different Regions of the metal body 1 different temperature-ZeitVerläufe to realize and thus to achieve a selective and individually adapted to the application temperature application of individual portions of the surface portions 6 and 7 of the metal body.

The first surface portion 6 brought into contact with the contact plates 2, 3 and the second surface portion 7 of the metal body 1 may be the same size. However, they can also have different sizes (not shown).

On the metal body 1, a sensor element 9 may be attached. Preferably, the sensor element 9 is a temperature sensor element. This allows the measurement of the temperature of the metal body. The temperature measured in this way can serve, for example, as an input variable for a temperature control device that controls or regulates the temperature-time profile of the thermal treatment.

The method can also be configured such that a plurality of metal bodies are simultaneously brought into contact with at least one first and / or one at least one second contact plate simultaneously.

Fig. 2 shows a schematic sectional view of another embodiment of the method according to the invention. The metal body 1 was brought into contact by moving the first contact plate 2 with this and a second contact plate 3. The contact plates are arranged to run parallel to each other. The first contact plate 2 is or was replaced by a Power source 5 is brought to a relative to the metal body increased or decreased temperature. The second contact plate 3 is or was brought by a further energy source 5 to a relative to the metal body increased or decreased temperature. In this case, the first contact plate 2 and the second contact plate 3 can be brought by the energy sources both at the same temperature and at different temperatures.

Fig. 3a shows a schematic sectional view of a first process step to a temperature of the contact plates. The first contact plate 2 and the second contact plate 3 are brought into mutual contact with each other before contacting with the metal body. Subsequently, the second contact plate 3 is heated or cooled by the power source 5. The temperature is subsequently transferred to the first contact plate 2 which is in contact with the second contact plate 3.

Fig. 3b shows a schematic sectional view of a second method step to an application of the contact plates, which conform to the in Fig. 3a followed by the process step. The first contact plate 2 and the second contact plate 3 are separated from each other. The metal body 1 is inserted between the separate contact plates.

Fig. 3c shows a schematic sectional view of a third process step to an application of the contact plates, which conform to the in Fig. 3b followed by the process step. The first contact plate 2 and the second contact plate 3 were brought into contact with the metal body 1. It owns both the first Contact plate 2 and the second contact plate 2 a relative to the metal body 1 increased or decreased temperature.

Fig. 4 shows a schematic sectional view of another embodiment of the method according to the invention. In this case, the metal body 1 was brought into contact with a first contact plate 2 and a second contact plate 3. In this case, the first contact plate 2 is in contact with a plurality of first surface portions 6 of the metal body 1. The second contact plate 3 is in contact with a plurality of second surface portions 7 of the metal body 1. The contact plates are formed flat according to the contour of the surface portions of the metal body and in the state of contacting with the metal body substantially parallel to each other, ie they extend at a constant distance from each other, arranged.

If the metal body is to be subjected to a cooling treatment, the first contact plate 2 and third contact plate 3 may be formed so that they can be cooled. As a result, the metal body can be cooled exactly in the course of the thermal treatment.

This cooling can be carried out so that, for example, a solidification of the material occurs. Preferably, cooling channels (not shown) may be present in the first contact plate 2 and / or in the second contact plate 3. Through these cooling channels liquid or gaseous coolant can be introduced.

If both a heating and a cooling treatment are provided during the thermal treatment, the same contact plates 2, 3 can be used for both partial treatments. However, the cooling can also be done by contact elements that differ from the contact plate 2.3 for heating.

Fig. 5 shows a schematic sectional view of a further process step of the method according to the invention, in which, after the desired temperature for the thermal treatment has been applied to the metal body, at least one contact plate has been removed. The metal body 1 is only in contact with a first contact plate 2. This makes it possible to influence the formation of the temperature profile of the metal body 1.

Fig. 6 shows a schematic sectional view of another embodiment of the method according to the invention. In this case, first contact plates 2 and a plurality of second contact plates 3 were brought into contact with a metal body 1. In each case a contact plate pair of a first contact plate 2 and a second contact plate 3 are arranged parallel to each other. The individual contact plate pairs are interconnected by flexible transition elements 10. As a result, a particularly flexible contacting of the contact plates 2, 3 with the metal body 1 is achieved. Due to the flexible transition elements 10, it is possible to easily adapt the contact plates 2, 3 to differently shaped metal bodies 1.

Fig. 7 shows a schematic sectional view of another embodiment of the method according to the invention. In this case, first contact plates 2 and a plurality of second contact plates 3 were brought into contact with a metal body 1. In each case a contact plate pair of a first contact plate 2 and a second contact plate 3 are arranged parallel to each other.

Fig. 8 shows a schematic sectional view of another embodiment of the method according to the invention. In this case, first contact plates 2 and a plurality of second contact plates 3 were brought into contact with a metal body 1. The contact plates 2, 3 can both be arranged in such a way that the contact plates 2, 3 belonging to a contact plate pair have the same size. However, they can also have different sizes. Also, each contact plate 2, 3 may have only one surface that contacts the metal body 1. However, it is also possible for a plurality of surfaces of a contact plate 2, 3 to come into contact with the metal body 1.

REFERENCE NUMBERS

1

metal body

2

First contact plate

3

Second contact plate

4

direction

5

energy

6

First surface section

7

Second surface section

8th

insulation layer

9

sensor element

10

Flexible transition element

Claims (11)

1. Method for the thermal treatment of at least one metal body (1),
   wherein

   - the metal body (1) is fixed in position,

   - in a first method step:

   - at least one first contact plate (2) is moved into contact with at least one first surface-area portion (6) of the metal body (1),

   - at least one second contact plate (3) is moved into contact with at least one second surface-area portion (7) of the metal body (1),

   - the contact plates (2, 3) have an areal form substantially or completely corresponding to the contour of the surface-area portions (6, 7) of the metal body (1) and, when they make contact with the metal body (1), are arranged so as to run substantially parallel to one another, and

   - at least one contact plate (2, 3) is at a higher temperature than the metal body (1) during contact with the metal body (1),

   characterized in that, in a subsequent method step:

   - at least one first contact plate (2) is moved into contact with at least the first surface-area portion (6) of the metal body (1),

   - at least one second contact plate (3) is moved into contact with at least the second surface-area portion (7) of the metal body (1),

   - the contact plates (2, 3) have an areal form substantially or completely corresponding to the contour of the surface-area portions (6, 7) of the metal body (1) and, when they make contact with the metal body (1), are arranged so as to run substantially parallel to one another, and

   - at least one contact plate (2, 3) is at a lower temperature than the metal body (1) during contact with the metal body (1).
2. Method according to Claim 1,
   wherein

   - the metal body (1) is a metal sheet or a shaped sheet metal part, and

   - the at least one first surface-area portion (6) is located on the top side of the metal sheet and the at least one second surface-area portion (7) is located on the bottom side of the metal sheet.
3. Method according to Claim 2,
   wherein the metal sheet or shaped sheet metal part is provided at least in parts with a zinc layer.
4. Method according to one of the preceding claims,
   wherein the metal body (1) is shaped in a subsequent working step and the at least one first surface-area portion (6) and second surface-area portion (7) lie in or in the vicinity of the region which is subsequently to be shaped.
5. Method according to one of the preceding claims,
   wherein the contact plates (2, 3) are pressed onto the metal body.
6. Method according to one of the preceding claims,
   wherein the temperature of the at least one contact plate (2, 3) is regulated at a higher or lower temperature before and/or during the contact between the metal body (1) and the contact plates (2, 3) by a temperature regulating device.
7. Method according to one of the preceding claims,
   wherein the temperature in at least one partial region of the at least one contact plate (2, 3) is regulated at a higher or lower temperature before and/or during the contact between the metal body (1) and the contact plates (2, 3) by a temperature regulating device.
8. Method according to one of the preceding claims,
   wherein at least one contact plate (2, 3) is removed in a further method step.
9. Method according to one of the preceding claims,
   wherein the first contact plates (2) and/or the second contact plates (3) are connected to one another with a flexible transition element (10).
10. Method according to one of the preceding claims,
    wherein different contact plates (2, 3) are used for the heating than for the cooling.
11. Method according to one of the preceding claims,
    wherein at least one contact plate (2, 3) is cooled in particular in one method step.

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