EP2293891B1 - Mould for casting metal - Google Patents

Description

The invention relates to a mold for casting metal with a plurality of temperature measuring devices, which are arranged in a wall in the mold for detecting the temperature distribution in the wall during the casting operation.

Such a mold having a plurality of temperature measuring devices is known in the art and, for example, in the international patent application WO 2004/082869 A1 disclosed. According to the technical teaching described therein, the temperature measuring devices are introduced in the form of thermocouples individually in each case provided for them individual holes in the mold. The individual thermocouples are pressed with a spring force against the bottom of the hole to ensure there the contact of their measuring points with the mold material. The thermocouples are inserted into the mold plate at different depths. This is particularly useful for determining the heat flux density in the mold plate.

The mentioned type of individual mounting of each individual thermocouple in the chill plate requires a high installation height. The connection of the thermocouples typically takes place via a separate Harting coupling. During installation, the coupling is often accidentally damaged, whereupon a complex reconstruction of the correct connection is made. The problem is the positioning of the thermocouples to each other. At a distance of, for example, only 10 mm, a deviation of the bore depth and thus the position of the measuring tips of the thermocouples in the depth direction of only 1 mm already leads to a ten percent deviation in the measurement result.

Based on this prior art, the invention has the object, a known mold for casting metal with a plurality of temperature measuring devices to the effect that the cost of installation of the plurality of temperature measuring devices is reduced, but at the same time a high reliability and validity of the knife is maintained.

This object is solved by the subject matter of patent claim 1. This is characterized in that the temperature measuring devices are arranged in a module fixed to each other positioned and together with the module form a structural unit and that the structural unit for detecting the temperature distribution is fixed in or on the wall of the mold.

The great advantage of the solution according to the invention is that the structural unit, that is, the module with the temperature measuring devices arranged therein, can be pre-assembled in a workshop in the workshop before the assembly of the entire mold in the workshop.

The pre-assembly of the temperature measuring devices in the module advantageously allows a free and accurate positioning of the temperature measuring devices to one another, ie at a desired correct distance from each other and at the correct depth; In particular, the distances are no longer necessarily by the distances of fastening bolts, with which the water tank is screwed to the mold and in which the temperature measuring devices, in particular in the form of thermocouples, were traditionally defined. Instead, the pre-assembly in the module allows such a short spacing of the temperature measuring devices or their measuring tips to each other, for example 10 mm, that a complete monitoring of the cooling and solidifying strand in the mold with respect to longitudinal cracking and breakthrough early detection over the entire width of the strand through Evaluation of the measured temperature distribution is possible. In general, the free positioning of the temperature measuring devices can Deviations of the measurement results are reduced to a minimum and thus the significance of the measurement can be significantly increased.

During the final assembly of the mold, the structural unit including the temperature measuring devices is then only to be fastened as a whole in or on the wall. The installation effort for the temperature measuring devices, especially in the final assembly of the mold is therefore limited to a minimum.

According to a first embodiment of the invention, the wall of the mold has a recess for receiving the structural unit. It should be noted that the best possible heat transfer between the structural unit and the material of the mold is guaranteed. On the one hand, it is important for the depth of the recess to be matched to the depth or height of the module and, in particular, for the best possible large area between the base or the wall of the recess in the mold and the surface of the module or the measuring tips of the measuring devices Contact is formed to ensure optimum heat transfer between the module and mold wall. The heat transfer can be improved, for example, by the use of a thermal grease, which, however, must withstand the high temperatures that occur in the mold during casting in the mold.

The structural unit is e.g. from the cold side into a wall of the mold or mounted on this: So that the structural unit does not affect the flow of coolant in the cooling channels of the mold wall, the structural unit is mounted in this case between two adjacent cooling channels.

Alternatively, the recess for the structural unit as a lateral, preferably horizontal, hole in the wall of the mold between the hot side and the bottom of the cooling channels is formed.

In order to disturb the heat flow in the wall of the mold as little as possible, the recess after installation of the structural unit is closed by a plate-shaped cover, preferably flush with the outer surface of the wall of the mold again. Then a heat flow through the cover is possible.

The module or the structural unit and the recess in the cold side of the mold are preferably in the thickness direction of the mold wall, i. transverse to the casting direction or from the cold to the hot side, stepped. The grading advantageously ensures a stabilization of the module or the structural unit in the mold against tilting.

Not only the cold side of the mold has, as described above, a recess, but also the module has in turn a recess, hereinafter called Temperaturmesseinrichtungs-recess, for receiving in each case a temperature measuring device. In this case, the temperature measuring device is arranged in the temperature measuring device recess such that its measuring tip or its measuring tips makes contact with the base or the wall of the recess.

The temperature measuring device may e.g. as a thermocouple or as a fiber optic. Temperature sensor may be formed, the latter allows a temperature measurement by means of the optical time domain reflectometry OTDR method or the Fiber Bragg Grating FBG method. The fiber optic temperature sensors are very thin; This has the advantage that many temperature measuring points can be arranged close to each other without their signals or measurement results mutually influencing and falsifying.

For the purpose of a reliable heat flow density measurement, the temperature measuring devices are arranged in pairs in the module, wherein the two temperature measuring devices, in particular thermocouples of a pair preferably protrude at different depths into the module or in the mold. The temperature gauge recesses in the module are accordingly formed differently deep.

The Temperaturmesseinrichtungs recesses in the module can be formed for example as a hole (stepped or not stepped) or as a groove on the edge of the module. The design as a groove has the advantage that in particular the measuring tip of the temperature measuring device are accessible when inserted into the module or in the groove and a contact of the measuring tip with the bottom of the Temperaturmesseinrichtungs-recess can be ensured. When using thermocouples whose measuring tips are advantageously soldered to the bottom of the grooves to guarantee optimum contact and heat transfer and precise positioning.

The temperature measuring devices are fixed in the temperature gauge recesses in the module. The fixation can be done by gluing or clamping the temperature measuring devices in the corresponding recesses. For gluing is advantageously high heat-resistant resin, eg. B. Strain gauge DMS resin used. Alternatively, the temperature measuring device can also be clamped in the temperature measuring device recess, in the case of thermocouples for example by means of an annular cone screw. Here, a thread with a conical spout is provided on the Temperaturmesseinrichtungs recess. The thermocouple is passed through the annular cone, preferably made of copper, with external thread. This cone or cone screw clamps the thermocouple then when screwing and pressed it by the screw at the same time to the bottom of the hole.

Advantageously, the module and its thermocouple recesses or holes is produced by erosion. The said quarter-shaped or stepped quartz-shaped form of the module is particularly suitable for this purpose. The manufacturing process "eroding offers the advantage that bore burrs and Bore cone can be avoided, while maintaining very precise compliance or realization of the desired hole depth. The one-time clamping of a component during erosion to produce a larger number of holes, the cost of erosion can be kept within limits.

To ensure optimal heat transfer, the module is preferably made of the same material as the mold itself.

To improve the clarity of the cable management, in particular with regard to the connection cables of the thermocouples on the module, we recommend the use of a central plug for the connection cables of the thermocouples on the module. Such a central plug can be designed as a pure multi-pin connector or as a multiplexer. Alternatively, the central plug can also be designed as a bus interface or bus module, for example a fieldbus module. Then the central plug would be able to convert the signals of the thermocouples into a bus format. At the same time, the bus interface or bus module should also be able to convert the conversion in the reverse direction, that is, from the bus format to a format for an actuator signal. When using a plurality of structural units, it may be useful to connect the central plug on the individual structural units with a parent central plug. In this circuit configuration, both the central plug and the parent central plug can be designed as bus interfaces.

About the central plug - possibly with the interposition of the parent central plug - the thermocouples can be connected to a suitable evaluation or a control device.

Figur 1

die Kaltseite einer Kokille mit der Ausnehmung bzw. mit der baulichen Einheit in a) einer Draufsicht, b) einer ersten Queransicht und c) einer zweiten Queransicht;

Figur 2

ein erstes Ausführungsbeispiel für die erfindungsgemäße bauliche Einheit in drei verschiedenen Perspektiven;

Figur 3

das erste Ausführungsbeispiel der erfindungsgemäßen baulichen Einheit in einer Variante mit Zentralstecker;

Figur 4

ein zweites Ausführungsbeispiel (gestuft) für die erfindungsgemäße bauliche Einheit;

Figur 5

eine Kokille für Rund, Rechteck und Quadrat; und

Figur 6

eine Kokille für Beam Blank

zeigt.The description is a total of 6 figures attached, wherein

FIG. 1

the cold side of a mold with the recess or with the structural unit in a) a top view, b) a first transverse view and c) a second transverse view;

FIG. 2

a first embodiment of the structural unit according to the invention in three different perspectives;

FIG. 3

the first embodiment of the structural unit according to the invention in a variant with central plug;

FIG. 4

a second embodiment (stepped) for the structural unit according to the invention;

FIG. 5

a mold for round, rectangle and square; and

FIG. 6

a mold for Beam Blank

shows.

The invention will be described in detail below with reference to the said figures in the form of embodiments. In all figures, the same elements are designated by the same reference numerals.

FIG. 1 a) shows the cold side of a mold, more precisely a (side) wall 100 of the mold in a plan view. There are vertically guided cooling channels 200 and between the cooling channels recesses 120, 120 'for the structural units 500 and 500' can be seen. The recesses 120 and thus also the structural units 500 or 500 ', if installed therein, are each arranged between two adjacent cooling channels. The modules 500 and 500 'are in FIG. 1 a) drawn differently long. This shows that the structural units with a different number of thermocouples can be provided in one and the same wall 100 of a mold.

FIG. 1 b) shows a section through the wall 100 of the mold according to Figure a) in the casting direction. It can be seen the recess 120 'for the structural unit and the cooling channel 200. The bottom of the recess 120 reaches very close to the hot side H of the mold wall 100 zoom. In this way, it is ensured that the thermocouples actually detect the temperature distribution in the vicinity of the hot side H of the mold in the most realistic manner possible.

FIG. 1c) shows a cross section through the wall 100 of the mold according to FIG. 1 a) transverse to the casting direction. This figure clearly shows the different cross-sections for the recesses 120 in the depth of the mold wall 100: strictly quarry-shaped, not stepped, according to a first embodiment 120 or stepped according to a second embodiment. In the gradation S, the width of the recess 120 'or the structural unit 500' tapers in the region of greater depths. Due to this grading a greater rigidity of the structural unit is achieved when installed in the recess.

FIG. 2 illustrates the first embodiment for the structural unit 500. It will be appreciated that the temperature gauge recesses 420 for the thermocouples 300 in the module 400 are exemplified in the form of grooves on the sidewalls of the module. The formation of the grooves on the side edges has the advantage that the thermocouples are accessible after insertion into the grooves; In particular, in this embodiment, the measuring tip 310 of the thermocouples 300 may be soldered to the bottom of the groove. In FIG. 2 It can also be seen that the thermocouples are arranged in pairs opposite one another. The thermocouples involved in such a pair protrude at different depths into the module; Compare the distances A and B respectively between the measuring tips 310 of the thermocouples and the hot-side boundaries H 'of the modules. These different distances A and B are required for a reliable calculation of the heat flux density in the mold wall.

The FIG. 3 shows the first embodiment of the module or the structural unit according to FIG. 2 supplemented with a central plug 600 on the module 400. To the central plug 600 all connection cables 330 of the thermocouples 300 can be connected to the module and bundled. It allows the transmission of the signals of all thermocouples via preferably only a single, but possibly multi-core output cable 700. For this purpose, the central connector may be formed, for example in the form of a multi-pin connector. Alternatively, the plug can also be designed as a multiplexer. In a further alternative, the central plug can also be designed as a bus interface and the cable 700 as a bus line. The bus interface, also called bus module, is then designed to convert the signals of the thermocouples into the format or protocol of the particular bus used.

FIG. 4 shows a second embodiment of the module according to the invention, here in the form of a stepped version. The stage is in FIG. 4 each partially traversed in the form of vertical lines, partially indicated by dashed lines in each case with the reference symbol S. Especially vivid is the level in FIG. 1 a) to recognize.

FIG. 5 shows a measuring arrangement of a mold for round, rectangle and square.

FIG. 6 shows a measuring arrangement of a mold for Beam Blank.

LIST OF REFERENCE NUMBERS

100

Wall of the mold

120

Recess for the structural unit 500

120 '

Recess for the structural unit 500 '

200

cooling channel

300

thermocouple

330

Connection cable thermocouple

400

module

420

Recess for thermocouple

500

Building unit according to the first embodiment

500 '

Building unit according to the second embodiment

600

central plug

700

output cable

A, B

distances

S

step

Claims (12)

1. Mould for the casting of metal, with a plurality of temperature measuring devices (300), which are arranged in a wall (100) of the mould, for detecting the temperature distribution in the wall during casting operation;
   wherein the temperature measuring devices (300) are arranged in a module (400) to be fixed in position relative to one another and form together with the module a constructional unit (500, 500');
   wherein the module (400, 400') comprises at least one temperature measuring device recess (420) in the form of a bore or groove for reception of a respective one of the temperature measuring devices; and
   wherein the constructional unit (500, 500') for detection of the temperature distribution is fastened in or to the wall (100) of the mould;
   characterised in that:

   the temperature measuring devices are constructed as fibre-optical temperature sensors which enable temperature measurement by means of the Optical Time Domain Reflectometry (OTDR) method or the Fibre Bragg Grating (FBG) method; and

   the temperature measuring device recesses (420) are so arranged in the module (400) and constructed that the fibre-optical temperature sensors are arranged in pairs and

   adjacently in the module and that the individual fibre-optical temperature sensors of a pair are arranged at different depths in or on the module.
2. Mould according to claim 1, characterised in that the wall (100) of the mould has a recess (120, 120') for reception of the constructional unit (500, 500').
3. Mould according to claim 2, characterised in that the recess (120) for the constructional unit (500, 500') is arranged on the cold side of the wall of the mould between the cooling channels (200) thereof.
4. Mould according to one of claims 2 and 3, characterised in that the module (400') and the recess (120') is formed to be stepped in the direction from the cold side to the hot side of the mould.
5. Mould according to claim 2, characterised in that the recess (120, 120') for the constructional unit (500, 500') is constructed as a lateral, preferably horizontal, bore in the wall of the mould between the hot side thereof and the base of the cooling channels.
6. Mould according to any one of claims 2 to 5, characterised in that the recess (120, 120') is closed by a plate-shaped cover, preferably flush with the outer surface of the wall of the mould, after installation of the constructional unit (500, 500').
7. Mould according to claim 1, characterised in that the temperature measuring device recess (420) is constructed to be stepped with different diameters as seen over the depth thereof.
8. Mould according to any one of the preceding claims, characterised in that the temperature measuring device (300) is so glued or releasably clamped in place in the temperature measuring device recess (420) that the measuring tip or measuring tips (310) of the temperature measuring device (300) contacts or respectively contact the base or the wall of the temperature measuring device recess (420).
9. Mould according to any one of the preceding claims, characterised in that the module and the temperature measuring device recesses thereof are produced at least in part by eroding.
10. Mould according to any one of the preceding claims, characterised in that the module and/or the cover for closing the recess (120) is or are made of the same material as the mould, for example of copper.
11. Mould according to any one of the preceding claims, characterised in that provided in or on the module is a central plug (600) for receiving and grouping the connection lines (330) of all temperature measuring devices (300) on the module (400).
12. Mould according to claim 11, characterised in that the central plug is constructed as a multiplexer or as a bus interface or bus module.

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