Mould body and method for monitoring the mould body

Abstract

The invention relates to a mould body (1) comprising a sensor box (3) having the following features: a. The sensor box (3) has a length sensor system (18) for measuring a thickness of the mould body (1), wherein the length sensor system (18) has a plurality of conductor tracks arranged at a distance from one another in the thickness direction, wherein the sensor box (3) uses the number of conductor tracks present to determine a measured value which correlates with the thickness of the mould body (1), b. The sensor box (3) has an NFC antenna (10); c. The sensor box (3) has a control unit (9) and a battery (8); d. The control unit (9) has a processor, a flash memory, a RAM memory, at least one further sensor and a second antenna.

Description

[0001] Mould body and method for monitoring the mould body

[0002] The invention relates to a mold body and a method for monitoring the mold body

[0003] The mold bodies of continuous casting molds are subject to wear during use, which leads to changes in the surface of the casting side. The casting sides are reconditioned by the operator. Reconditioning is achieved by removing material. The process can be repeated several times. The usage data and the rework status are recorded for this purpose.

[0004] Casting process data, such as operating time, are usually only manually linked to mold data, such as plate thickness or rework status. Process data on the mold's rework status are generally recorded and documented manually. Regarding the state of the art, reference is made to DE 100 28 304 A1, which discloses a method for processing casting data from a continuous casting mold. It is proposed to arrange cooled fieldbus modules directly on the continuous casting mold and to feed the data to a control system of the continuous casting plant via a bus line.

[0005] EP 3 831 510 A1 discloses that a sleeve can be arranged in a recess on a mold wall of a continuous casting plant, in which sleeve an RFID transponder is fixed by means of adhesive in order to implement usage tracking.

[0006] US 2013 / 0 333 473 A1 describes a real-time monitoring method for mold plates in which the data is transmitted wirelessly.

[0007] The invention is based on the object of demonstrating a mold body and a method for monitoring it, whereby the casting process data can be recorded more easily in order to be able to use them better for reworking.

[0008] To solve this problem, a mold body according to patent claim 1 and a method for monitoring the mold body according to patent claim 7 are proposed.

[0009] The mold body according to the invention has at least one sensor box with the following features: The sensor box has a length sensor for measuring the thickness of the mold body, wherein the length sensor has a plurality of conductor tracks arranged at a distance from one another in the thickness direction of the mold body. The sensor box determines a measured value based on the number of conductor tracks present, which correlates with the thickness of the mold body. Furthermore, the sensor box has an NFC antenna, a battery, and a control unit. The control unit has a processor, a flash memory, a RAM memory, at least one further sensor, and a second antenna. The NFC antenna is equipped for near-field communication. It serves to wake up the sensor box's sensors using an external signal and enable subsequent data transfer for reading the sensor box. The battery ensures a power supply.The entire sensor system, especially the components of the control unit, is preferably optimized to achieve a service life of more than 5 years without replacing the battery or the sensor box of the mold plate.

[0010] Flash memory is a digital memory chip for non-volatile storage without maintenance power consumption. It is also known as flash EEPROM. In particular, flash memory stores a unique identifier (the mold body ID).

[0011] The control unit also contains at least one additional sensor. One of the at least one additional sensor serves to record oscillations of the mold body. The control unit contains a second antenna. The second antenna is preferably a Bluetooth Low Energy (BLE) antenna. This standard is specifically designed for sensors to transmit wireless data with the greatest possible energy efficiency. The data is read out contactlessly.

[0012] With the mold body according to the invention and the at least one sensor box arranged on it, casting process data can be recorded, such as the operating time and oscillation, as well as mold process data, e.g., the plate thickness. The sensor box automatically records the mold process data. The mold data also includes the maintenance history, which can be documented. By using multiple sensor boxes, i.e., by recording the oscillation at multiple points on a mold, it is possible to detect wobbling movements of the mold body. Wobbling movements can cause increased mold wear, product defects, or, in extreme cases, strand breakage.

[0013] With regard to the rework condition of the mold plate, it is considered particularly advantageous if the sensor box is connected to a length sensor for measuring the thickness of the mold body. The length sensor has several conductor tracks arranged at a distance from one another in the thickness direction. The conductor tracks have a defined spacing. The distance between the conductor tracks is, for example, 0.05 or 0.2 millimeters and defines a measuring increment. If the mold plates show signs of wear, they are reworked. During the process, the mold plate is milled off. Due to the positioning of the length sensor or the individual conductor tracks, the number of conductor tracks is reduced or individual conductor tracks are interrupted. The sensor box or the sensors arranged therein determine the number of existing orintact conductor tracks, which, due to the incremental arrangement, assumes a specific measured value, which in turn correlates with the thickness of the mold body. In this way, the rework status of the mold plate can be automatically recorded.

[0014] The sensor box has a housing and a lid, protecting the sensors. The sensor box is detachably connected to the mold body. Specifically, the sensor box is screwed to the mold body. Housing the sensors in a housing with a lid has the advantage that the sensor box can be removed during the rework step. The sensor box is preferably made of plastic, particularly Teflon, to enable reading of the sensors using NFC and the second antenna.

[0015] The sensor box is preferably positioned in a highly protected manner on the mold body. In particular, the mold body is a mold plate with a narrow end face into which the sensor box is inserted. The sensor box has a base body arranged at a distance from a casting side of the mold plate. The base body has, in particular, a flange that projects towards the casting side. The length sensor for measuring the thickness of the mold plate is preferably arranged, at least in part, on this flange projecting towards the casting side. The sensor box is preferably attached to the upper area of ​​an end face of a mold plate. The term "top" refers to the installation position, with "top" referring to the pouring end of the mold.

[0016] Overheating of the sensors is prevented in this position. There is no contact between the base body and the liquid melt. Furthermore, the sensors can be positioned so that the length sensors have direct contact with the hot side / casting surface of the mold plate being machined.

[0017] A method for monitoring the mold body is described in claim 7, according to which the at least one additional sensor detects an oscillation of the mold body during casting, with the time of the oscillation being stored. If an acceleration, i.e., an oscillation, is detected, a measurement is performed over a period of a few seconds, for example, 5 to 15 seconds, in particular 10 seconds. Using logic adapted to the continuous casting process, the control unit can automatically detect whether a casting process is taking place.

[0018] The frequency range of the mold body's oscillation is preferably between 1 Hz and 10 Hz. Furthermore, a sinusoidal motion must be present. Sinusoidal motion is detected using an FFT analysis.

[0019] If these conditions are met, the control unit records the start time of the acceleration event. A control measurement is automatically performed after a specified interval, for example, after 5 to 30 minutes. This measurement is compared with the previous measurement. If the measurement has similar parameters, e.g., a similar frequency range, the onset time and the center frequency in Hz are recorded for this measurement period. The onset time and the oscillation are recorded for as long as the oscillation or acceleration event, i.e., the casting sequence, lasts. All data is preferably encrypted.

[0020] An interface can be used to identify the mold body and establish a connection to the sensors, which transmit the sensor data to a readout unit and from there to an evaluation unit. This can be a mobile handheld device, particularly a smartphone. Modern smartphones have the necessary antennas and interfaces. Evaluation is carried out via an app on the smartphone or specially provided software on a mobile handheld device. The evaluation unit can transfer the data to a server-side database, which can be accessed by manufacturers and / or customers via specific interfaces. In particular, all sensors can only be read using a digital key that can be verified on the smartphone or the readout unit.

[0021] Before the sensors are installed in the mold body, it is essential that they are uniquely identified with the mold body ID. The total time, i.e. the sum of all individual sequences of mold body usage, is then calculated using the app on the smartphone or readout unit. The process data is displayed sequence by sequence in the app. The read-out data can be supplemented with photos and text generated directly on the smartphone, which is helpful for maintenance documentation. The app can be used to synchronize the data obtained with a server-based database. In addition to the casting process data, the database can also contain other information such as customer information, master data, product name, material, material batch number, order date, production date, coating, taper, drawing number and weight.In addition, documents such as dimensional reports, drawings, etc. can be included in the database. The database can also be accessed via a customer portal. The customer portal can display automated statistics regarding temperature load and operating times, which can be used to determine the performance of the mold plates.

[0022] In particular, the use of several sensors in a mold body makes it possible to determine harmful wobbling movements of the mold body.

[0023] Initially, a mold body can be provided with a unique identifier, such as a QR code. The QR code can be read by a camera on a smartphone, which correlates with the mold body ID stored in the sensor box. Once this data is linked, the QR code becomes unnecessary. All casting data and mold condition data can then be automatically assigned via the smartphone.

[0024] With the mold body according to the invention and the method for monitoring the mold body according to the invention, it is no longer necessary to manually link casting process data with mold data, especially the plate thickness. Process data on the mold's rework status no longer need to be manually recorded and documented. The mold's performance can be evaluated automatically. Furthermore, wobbling movements on the mold side can be detected to draw conclusions about increased mold wear. The invention is explained in more detail below using an exemplary embodiment illustrated in the drawings. They show:

[0025] Figure 1 is a perspective view of a mold body with an enlargement of a detail in its upper corner area;

[0026] Figure 2 shows a sensor box inserted into the mold body of Figure 1;

[0027] Figure 3 shows the sensor box of Figure 2 in a first side view;

[0028] Figure 4 shows the sensor box of Figure 2 in a view of its lid and

[0029] Figure 5 shows the overall system for monitoring the mold body.

[0030] Figure 1 shows a mold body 1 in the form of a mold plate with a view of its casting side 19. In the upper corner area of ​​the mold body 1, on an end face 2, there is a sensor box 3, which is shown somewhat larger in the detailed view. Figure 2 shows the sensor box 3 with further details. The sensor box 3 has roughly the shape of a mortise lock for a door, i.e. its housing 4 has a narrow, cuboid-shaped base body 15, on one end of which, at opposite upper and lower ends, fastening tabs 16, 17 are arranged. The fastening tabs 16, 17 protrude beyond the cuboid-shaped base body 15. The sensor box 3 is inserted into the end face 2 and does not protrude beyond the end face 2 of the mold body 1. The sensor box 3 is located in the upper outer area of ​​the mold plate or mold body 1 shown in order to prevent the sensors from overheating.The sensor box has a length sensor 18 for measuring the thickness of the mold body 1 .

[0031] The sensor box 3 has a cover 5 made of plastic, particularly Teflon. The base body 15 with the mounting tabs 16, 17 is recessed into a recess in the front face 2. The cover 5, which can be screwed to the front face 2 and the mounting tabs 16, 17 using screws 6, 7, is flush with the surface of the front face 2. This protects the sensor box 3 from mechanical damage.

[0032] The sensor box 3 contains a battery 8 and a control unit 9. The control unit 9 has a processor, a flash memory, a RAM memory, another sensor, which in this case is an acceleration sensor, and a second antenna. The second antenna is a BLE antenna. The NFC antenna 10 is located on the front of the sensor box 3, i.e., in the area of ​​the lid 5. The NFC antenna 10 is used to wake up the sensors and initiate the data exchange upon first contact with a reader (not shown in detail).

[0033] The housing 4 of the sensor box 3 has a flange 20 adjacent to the cover 5, which extends to the casting side 19 of the mold body 1 in the installed position according to Figure 1. The flange 20 is completely covered by the cover 5, so that the cover 5 is wider than the base body 15 between the end fastening tabs 16, 17. The flange 20 extends over the entire length of the base body 15, whereby the longitudinal direction, i.e. the length, refers to the casting direction in the installed position. A gap 21 is located between the cover 5 and the flange 20 (Figure 3). The length sensor 18 is arranged in the gap 21 (Figure 2). In the installation position according to Figure 1, the flange 20 and the cover 5 with the length sensor 21 located between them protrude up to the casting side 19. When the casting side 19 is reworked, ie milled, material of the flange 20, material of the length sensor 18 and also material of the cover 5 are removed at the edge at the same time.In the initial situation, the flange 20 and the cover 5, together with the length sensor 18 located between them, are each flush with the casting side 19 with their narrow edges (Figure 1). The cover 5 and the flange 20 hold the length sensor 18 and support it, particularly during material-removing machining.

[0034] The length sensor 18 has spaced-apart conductor tracks, the number of which decreases incrementally as material is removed. During reworking of the mold body 1, the thickness of the mold body 1 changes incrementally. These incremental changes are detected by the length sensor 18 and the sensor box 3 and allow conclusions to be drawn about the thickness of the mold body 1.

[0035] Figure 5 shows an overall system for monitoring the mold body 1. A reading unit 11 in the form of a smartphone can read a QR code 14 using a camera and is also in wireless contact with the sensor box 3 on the mold body 1. It evaluates the read data and transmits it to a server architecture 12 for further processing. A customer portal 13 can be provided via the server architecture 12 to provide customers with mold-specific data.

[0036] Reference symbol:

[0037] 1 - Mould body

[0038] 2 - Front side

[0039] 3 - Sensor box

[0040] 4 - Housing

[0041] 5 - Lid

[0042] 6 - Screw

[0043] 7 - Screw

[0044] 8 - Battery

[0045] 9 - Control unit

[0046] 10- N FC antenna

[0047] 11 - Reading unit

[0048] 12- Server architecture

[0049] 13- Customer portal

[0050] 14- QR code

[0051] 15 - Base body

[0052] 16- Mounting tab

[0053] 17- Mounting tab

[0054] 18- Length sensors

[0055] 19- Pouring side

[0056] 20 - Flange

[0057] 21 - Gap

Claims

Patent claims 1. A mold body (1) with a sensor box (3) having the following features: a. The sensor box (3) has a length sensor system (18) for measuring a thickness of the mold body (1), wherein the length sensor system (18) has a plurality of conductor tracks arranged at a distance from one another in the thickness direction, wherein the sensor box (3) determines a measured value based on the number of conductor tracks present, which correlates with the thickness of the mold body (1), b. The sensor box (3) has an NFC antenna (10); c. The sensor box (3) has a control unit (9) and a battery (8); d. The control unit (9) has a processor, a flash memory, a RAM memory, at least one further sensor and a second antenna.

2. Mould body (1) according to claim 1, characterized in that the second antenna is a Bluetooth Low Energy antenna.

3. Mould body (1) according to claim 1 or 2, characterized in that the sensor box (3) has a housing (4) and a cover (5).

4. Mould body (1) according to claim 3, characterized in that the housing (4) is made of Teflon.

5. Mould body (1) according to one of claims 1 to 4, characterized in that it is a mould plate which has an end face (2) into which a base body (15) of the sensor box (3) is inserted, so that it is arranged at a distance from a casting side (19) of the mould plate (1), and wherein the length sensor (18) for measuring the thickness of the mould plate is arranged on a flange (20) of the sensor box (3) projecting towards the casting side (19).

6. Mould body (1) according to one of claims 1 to 5, characterized in that it has several sensor boxes (3).

7. Method for monitoring the mold body (1) according to one of claims 1 to 5, characterized in that the at least one further sensor detects an oscillation of the mold body (1) during casting, the time of the oscillation being stored.

8. The method according to claim 7, characterized in that the NFC antenna (10) is activated by a readout unit (11), wherein the NFC antenna (10) activates the control unit (9), wherein the control unit (9) establishes a connection between the control unit (9) and the readout unit (11) via the second antenna, whereupon a data transfer to the readout unit (11) takes place.

9. Method according to claim 8, characterized in that the data transfer comprises the transfer of a mold body ID stored in the control unit (9), which is checked in an evaluation unit of the readout unit (11) and, after successful checking, enables a further data transfer to the readout unit (11).

10. Method according to one of claims 7 to 9, characterized in that a wobbling movement of the mold body (1) is determined via the read-out acceleration data of several sensor boxes (3) of a single mold body (1).

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