EP3187599B1 - Temperature control station. - Google Patents

Description

The present invention relates to a tempering station having the features in the preamble of claim 1.

From the prior art, hot forming and press hardening technology is known. Here, boards are at least partially, in particular completely heated to a temperature above Austenitisierungstemperatur. Depending on the steel alloy used, these temperatures are around 700 ° C, usually 900 ° C or higher.

After heating, the board is thermoformed and then cured by rapid cooling.

From the prior art, various methods are known for heating such a board. Often, continuous ovens are used.

Recently, however, increasingly tempering stations with contact heating have become known. For this purpose, at least one side of a contact plate on the heated area of the board or applied to the entire board and the heat of the contact plate discharged by heat conduction to the board. As a result of the heating, the board expands in particular in the direction parallel to the surface of the contact plate. Due to the plant contact with the contact plate, this thermal expansion in mass production leads to a plastic deformation of the contact plate. Furthermore, voltages are introduced at least in the region of the surface of the board to be heated. From the pre-registered, but post-published WO 2017/020888 A1 a contact head is known, which rests for heating with a contact pressure between 100 kPa and 10 MPa at a portion of a component to be heated.

Furthermore, from the DE 10 2013 021 264 A1 as well as the EP 2 439 289 A1 a method and apparatus for heating of boards known in which contact heating is used.

Object of the present invention is therefore to improve the possibilities of contact heating of a board.

The above object is achieved with a tempering for contact heating of a board with the features in claim 1.

Advantageous embodiments of the invention are described in the dependent claims.

The temperature control station for contact heating of a circuit board is used to heat it to a temperature above room temperature. In particular, the target temperature of the board is more than 500 ° C, most preferably more than Austenitisierungstemperatur thus more than 700 ° C, in particular more than 900 ° C. The board can be partially heated, but preferably also completely.

For this purpose, the temperature control station has an upper tool and a lower tool, wherein a contact plate for contact heating is provided at least on the upper tool and / or on the lower tool. After inserting the board, upper tool and lower tool are closed, so that a contact pressure is exerted on the board to be tempered or to be heated when the temperature control station is closed. According to the invention this is closed Temperierstation exerted contact pressure now adjustable or controllable. This makes it possible according to the invention that the static friction between board to be heated and contact plate can be optimized or minimized by the regulation or control such that a length or width change of the board occurring as a result of the contact heating does not lead to a change in length or irreversible Growth of the contact plate leads.

Consequently, the heating board can slide past due to low friction on the contact plate, but at the same time the contact pressure is adjusted or controlled so that a sufficient heat conduction from contact plate to board. As a benefit according to the invention, a circuit board which has been heated free of stress can be heated in a short cycle time in a process-economical manner, whereby the wear of the contact plate as a result of thermal expansion of the circuit board is simultaneously minimized in mass production.

The at least one contact plate is preferably formed as an elongated contact plate. This means for the purposes of the invention that this has at least one length which corresponds to twice the width. However, it is also possible, for example, to arrange a plurality of contact plates next to one another on a tool, preferably two or three elongate contact plates are arranged parallel next to one another.

In the context of the invention, the contact pressure exerted on the board to be tempered with the tempering station closed is determined in particular as a function of the contact area between the contact plate and the board and / or the cross-sectional area of the contact plate and / or the yield strength Rp _0.2 (from the contact plate) and / or Actual temperature (the contact plate) and / or the coefficient of adhesion (coefficient of friction) between contact plate and board regulated or controlled. Particularly preferably, the contact pressure is regulated or controlled as a function of the following formula: $$p<\frac{R{p}_{0.2}\left(T\right)*A{Q}_{\mathit{plate}}}{A{K}_{\mathit{circuit\; board}}*\mathrm{\mu }}$$

However, the contact pressure can also be calculated and then the tempering be adjusted so that the calculated contact pressure is applied. However, sensors may also be provided in the temperature control station and then the previously calculated contact pressure during the heating process are controlled. The contact pressure is preferably greater than zero.

Thus, it is possible to temper uncoated boards, in particular from a steel alloy, for example a boron-manganese steel. Tempering means for the purposes of this invention significantly heating. However, it is also possible for areas to be cooled simultaneously or kept at a temperature, whereas adjacent areas are heated. However, it is also possible with the invention to temper coated circuit boards, for example with an anti-corrosion coating, in particular an aluminum-silicon coating.

The heating of the at least one contact plate takes place in particular with one of the following heating sources. As inductive heating, so that by using an inductor, the contact plate is inductively heated and then in turn heated by heat conduction of the board. Also, the contact plate can be heated by means of a burner heating. Thus, on the side facing away from the board, the contact plate is heated by a burner and thus heats the board by heat conduction. It is also possible to carry out the heating as resistance heating. For this purpose, it is either provided that the contact plate itself is designed as an electrical resistance and heats itself when exposed to a voltage. However, an indirect or indirect resistance heating can be carried out so that heating conductors or heating cartridges are heated due to their electrical resistance and these heat the contact plate. The heating of the board is again by heat conduction from the contact plate to the board.

The contact plate itself is coupled via at least one movable bearing with the upper tool. In the case of a contact plate which is coupled to the lower tool, this is also coupled via at least one movable bearing with the lower tool. An expansion of the contact plate as a result of heating this itself can thus be compensated by the floating bearing. A curvature of the contact plate is thereby avoided.

In order that the contact pressure exerted on the board to be heated when the temperature control station is closed can then be changed in the course of regulation or control, this can be done in two preferred ways.

Either the main drive of the temperature control is used only to carry out the closing movement or opening movement of the temperature control. It can also be changed in the closed state of the pressure exerted on the board contact pressure on the main drive. In addition or as an alternative, additional actuators or control units can be provided which change the contact pressure exerted on the circuit board when the temperature control station is closed. Thus, the temperature control is initially closed with inserted board. The setting as well as the regulation and / or control of the contact pressure then takes place via the actuators. These can be operated in particular pneumatically, electrically or hydraulically.

In a further preferred embodiment variant of the invention, the contact pressure in two at least locally adjacent regions is adjustable differently from one another. Thus, the contact pressure is preferably different regions controllable or controllable. If, for example, a board is not heated at certain areas or at a lower temperature than an adjacent area of the board, the contact pressure can preferably be set differently from one another in both areas that are different from one another. In particular, different contact plates are then provided from each other, so that preferably for each contact plate individually the contact pressure can be controlled or controlled. Thus, the contact pressure on a contact plate can be partially set different from each other, or it can be used a plurality of contact plates, which are adapted to a different contact pressure.

Figur 1

die erfindungsgemäße Temperierstation im geöffneten Zustand in Seitenansicht,

Figur 2

die Temperierstation in geschlossener Ansicht aus Figur 1,

Figur 3a bis d

die Kontaktplatten mit aufliegender zu erwärmender Platine in Draufsicht,

Figur 4

zwei parallel nebeneinander liegende längliche Kontaktplatten in Draufsicht,

Figur 5

eine Kontaktplatte mit Fest- und Loslager in Seitenansicht und

Figur 6

eine Darstellung der Formelzeichen.

Further advantages, features, characteristics and aspects of the present invention are part of the following description. Preferred embodiments are shown in the schematic figures. These are for easy understanding of the invention. Show it:

FIG. 1

the tempering station according to the invention in the open state in side view,

FIG. 2

the temperature control station in closed view FIG. 1 .

FIG. 3a to d

the contact plates with overlying board to be heated in plan view,

FIG. 4

two parallel adjacent elongate contact plates in plan view,

FIG. 5

a contact plate with fixed and floating bearing in side view and

FIG. 6

a representation of the formula symbols.

In the figures, the same reference numerals are used for the same or similar components, even if a repeated description is omitted for reasons of simplicity.

FIG. 1 Further, a contact plate 4 is provided on the upper tool 2 and shown here in the lower tool 3 an insulating 5. It can, however, both the upper tool 2 and the lower tool 3 contact plates 4 to be arranged or on the lower tool 3, a contact plate 4 and on an upper tool 2 an insulating plate. 5

Furthermore, upper tool 2 and lower tool 3 each still have a base plate 6, wherein the contact plate 4 and insulating plate 5 is fixed to the base plate 6. In particular, the contact plates 4 or insulating plates 5 can be exchangeably coupled, in particular releasably coupled, so that an easy conversion to different board sizes to be heated is possible. Inserted in between is a board to be heated. 7

According to FIG. 2 is that out FIG. 1 shown tempering 1 closed. The closing movement is carried out by the lower tool 3. Here, actuators 8 are provided, which raise the base plate 6 and the insulating plate 5 in this case. The board 7 is thus substantially full surface with its top 9 on the contact plate 4 and with its bottom 10 on the insulating plate 5 at. there is applied between the contact surface 11 of the contact plate 4 and the contact surface 12 of the insulating plate 5 and the respective top 9 and the bottom 10 of the board 7, a contact pressure p. In the example shown here, the contact pressure p is the same everywhere. The contact pressure p, however, can be different in regions, in particular in the case of two contact plates 4 and / or insulating plates 5, which are separate from one another and are arranged next to one another in the vertical direction. According to the invention, the contact pressure p is regulated or controlled in the closed state via the actuators 8, so that an optimum contact pressure p is applied depending on the temperature, and in particular a lengthwise extension of the circuit board 7 in the longitudinal direction L does not cause a longitudinal expansion of the contact plate 4 and / or Insulating plate 5 leads. The board 7 can thus perform a relative movement to the contact plate 4 due to thermal expansion in the longitudinal direction L.

FIG. 3a to d show four different design variants of contact plates 4, 4a, 4b. FIGS. A, b and c each show a board 7 as a board blank, so that the area A7 of the board 7 is smaller than the area A4 of the contact plate 4, 4a, 4b. The design variant according to FIG. 3a shows a contact plate 4, which has a corresponding area A4 of the contact plate 4. In particular, the length L4 of the contact plate 4 is greater than the width B4 of the contact plate. According to FIG. 3b two contact plates 4a and 4b are provided. These each also have an area A4a or A4b. According to Figure 3c are also two contact plates 4a and 4b provided. A respective length extension of the board 7 in the longitudinal direction L is compensated according to the invention such that it performs a relative movement in the longitudinal direction L to the contact plate 4 / the contact plates 4a, 4b. Also, in all embodiments mentioned in this document, a relative movement in the transverse direction Q take place.

According to the embodiment variant of 3d figure a contact plate 4 is shown, on which two boards 7a and 7b rest simultaneously. These have an area A7a and A7b. Such boards 7a, 7b are used in particular for the production of door impact beams. Thus, two boards 7a, 7b can be tempered simultaneously in the tempering station according to the invention.

According to FIG. 4 is the example 3d figure shown again. The contact plate is formed of two contact plates 4a and 4b as resistance heating, so that a voltage can be applied via the connection of electrical poles 13, so that the contact plates 4a, 4b heat themselves. An electrical connection 14 ensures a flow of current through the contact plates 4a, 4b. Are placed two boards 7a, 7b.

FIG. 5 shows the contact plate 4 in side view. The storage takes place on one side with a fixed bearing 15 and on the opposite side with a floating bearing 16, so that due to the Festloslagerverbunds a longitudinal extension of the contact plate 4 is also made possible in the longitudinal direction L as a result of thermal heating.

FIG. 6 shows a contact _plate 4 with an attached board 7. Good to see here is the cross-sectional area AQ _plate and the surface AK _board . Between the board 7 and the contact plate 4 is then a coefficient μ. Illustrated by way of example is the contact pressure p, which according to the invention by pressing the contact plate 4 to another contact plate 4, not shown, or an insulating plate 5, in particular under integration of the board 7, is formed.

Reference numerals:

1 -

heating station

2 -

upper tool

3 -

lower tool

4 -

contact plate

4a -

contact plate

4b -

contact plate

5 -

insulation

6 -

baseplate

7 -

circuit board

7a -

circuit board

7b -

circuit board

8th -

actuator

9 -

Top to 7

10 -

Bottom to 7

11 -

Contact area to 4

12 -

Contact area to 5

13 -

electric pole

14 -

electrical connection

15 -

fixed bearing

16 -

movable bearing

A4 -

Area to 4

A4a -

Surface to 4a

A4b -

Area to 4b

A7 -

Area to 7

A7a -

Area to 7

A7b -

Area to 7

B4 -

Width to 4

L -

longitudinal direction

L4 -

Length to 4

p -

contact pressure

Q -

transversely

AK _board -

Area to 7

AQ _plate -

Cross-sectional area to 4, 4a, 4b

μ -

Haftbeiwert between 4 and 7

Claims (6)

1. Temperature adjustment station (1) for the contact heating of a blank (7), in particular for the at least partial austenitisation of a blank (7), having an upper die (2) and a lower die (3), with at least one contact plate (4, 4a, 4b), wherein the contact pressure (p) exerted on the blank (7), the temperature of which is to be adjusted, can be regulated or can be controlled when the temperature adjustment station (1) is closed, characterised in that a contact plate (4, 4a, 4b) is coupled to the upper die (2) via at least one movable bearing (16) and/or that a contact plate (4, 4a, 4b) is coupled to the lower die (3) via at least one movable bearing (16) and that the change in the contact pressure as a result of the regulation or control is performed by the main drive of the temperature adjustment station (1) and/or that actuators (8) are provided for this.
2. Temperature adjustment station according to claim 1, characterised in that the contact plate (4, 4a, 4b) is designed as an elongate contact plate, in particular the contact plate (4, 4a, 4b) has a length L which corresponds at least to 1.2 to 2 times the width (B4).
3. Temperature adjustment station according to claim 1 or 2, characterised in that the contact pressure (p) is regulated or controlled depending on the contact surface and/or the cross-sectional area of the contact plate (4, 4a, 4b) and/or the yield strength of the contact plate (4, 4a, 4b) and/or the coefficient of adhesion (µ) and/or the actual temperature.
4. Temperature adjustment station according to any one of claims 1 to 3, characterised in that at least one of the following heating sources: inductive heating, burner heating or resistance heating, is provided for heating the at least one contact plate (4, 4a, 4b).
5. Temperature adjustment station according to the preceding claim, characterised in that, in the case of resistance heating, the contact plate (4, 4a, 4b) as electrical resistor heats itself or that the contact plate (4, 4a, 4b) can be heated via heat conductors or heating cartridges.
6. Temperature adjustment station according to any one of claims 1 to 5, characterised in that the contact pressure (p) can be set differently in at least two locally adjacent regions.

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