Ladle for scooping and casting liquid metal, and process thereof

Abstract

The invention relates to a casting ladle for scooping and casting liquid metal, comprising a scooping bowl and a stem connected to the scooping bowl, wherein the casting ladle has a measuring unit having at least one sensor for measuring at least one physical parameter.

Description

[0001] The invention relates to a ladle for scooping and pouring liquid metal and a method for casting a workpiece using such a ladle.

[0002] The feeding of liquid casting materials of high-melting materials in foundries takes place automatically, semi-automatically or manually via a scooping process followed by pouring into a casting mold.

[0003] Automatic or semi-automatic casting processes and devices are described, for example, in CN 108 480 606 A, WO 2014 / 024955 A1, DE 10 2010008 944 A1, DE 22 37 249 A1 and jP S54 1 67107 U.

[0004] In the majority of light metal foundries, especially those using technological gravity casting processes, the scooping and / or pouring is often still carried out manually by an employee. Thus, the employee plays a significant role in the process.

[0005] Essentially, the metal is melted in melting units and transported to holding furnaces via transport crucibles. In the manual process, the employee (founder) uses the traditional and proven ladle and pouring tool (hereinafter referred to simply as the pouring tool) to carry out the actual casting process. The founder dips the pouring tool into the molten metal of the holding furnace, lets it remain in the molten metal bath for a short time, scoops the required molten metal from the holding furnace, and then often waits a short while, for example, by placing the ladle again (at the edge of the holding furnace) and intuitively begins the mold filling process "at some point" based on his experience.

[0006] Irregularities can arise in the process, which can lead to different properties during pouring and ultimately in the product (casting). For example, it is currently not possible to detect the exact pouring conditions and the associated properties of the liquid material during pouring. This, in turn, makes it impossible to draw conclusions as to whether and to what extent a part-specific pouring process is the cause of product defects. Furthermore, there is currently no way to correlate everyday, potentially varying environmental conditions with the manufactured casting and gain corresponding quality-relevant insights.

[0007] The object of the invention is to improve the analysis and standardization of the casting process for cast parts. This object is achieved by a pouring ladle according to claim 1.

[0008] Thus, the pouring ladle according to the invention is configured to detect at least one physical parameter during the pouring process, namely at least the temperature. This parameter can be a parameter of the liquid material in the ladle or a sensor measuring an environmental parameter. Depending on the value, by comparing the parameter with quality parameters of the casting, conclusions can be drawn about the relationships between quality and the measured value. This is the prerequisite for defining and ultimately monitoring a uniform pouring process.

[0009] The advantage of the pouring ladle according to the invention is therefore primarily that it significantly increases the repeatability of the casting / mold-filling processes across the entire series production batch. Consistent quality can be guaranteed across all quantities. The scrap resulting from debatable active conditions can therefore be significantly reduced. This also offers the possibility of batch-specific, documentable temperature and process parameter monitoring of manual casting processes. This can be significantly improved, particularly at the time of mold filling. This leads to quality assurance and can thus become a decisive competitive advantage when winning orders. Due to the monitoring options, the pouring ladle according to the invention is also particularly well suited as a training tool and, in particular, as a tool for prototype production.During prototype production, the operator cannot necessarily rely on a high degree of intuition and experience, so monitoring the process parameters makes it much easier to find the best process. According to the invention, the ladle is a manual ladle.

[0010] According to the invention, the handle is elongated starting from the scoop as a handle, as in a conventional ladle.

[0011] In a preferred embodiment, a connection between the ladle and handle is designed to be movable and / or detachable. A movable connection has the particular advantage that the pouring process can be carried out by pivoting or tilting the ladle, for example, by releasing a locking mechanism, while the position of the handle remains unchanged. Furthermore, the modular design enabled by this means that, in the event of wear, only individual parts, particularly the more highly stressed ladle, need to be replaced, thus allowing the more sophisticated modules to be reused or reused.

[0012] The scoop is preferably designed as a regular hollow body with one open side. The regular hollow body has, for example, the basic shape of a hemisphere or a cylinder, with corners preferably rounded at least on one inner surface of the hollow body to prevent adhesion and contamination.

[0013] To facilitate a targeted and locally limited pouring process, the ladle preferably has a pouring section, for example in the form of a groove or a spout. The pouring section is preferably realized as a molded portion of a wall of the ladle in the area of the opening, i.e., the open side of the hollow body.

[0014] In a preferred embodiment of the invention, the at least one sensor is selected from the group consisting of an (air) pressure sensor, (air) humidity sensor, inclination sensor, position sensor and / or a tactile sensor. Measuring the temperature of the melt in the shell, in particular at regular intervals throughout the entire process, enables the detection of one of the most important parameters, since the temperature of the melt can provide important information about the state of the melt. The temperature of the melt is preferably detected, in particular during the pouring process of several processes, and evaluated with regard to the quality of the castings produced in the respective process. In this way, the ideal pouring time can be determined and ultimately controlled based on the temperature of the melt.

[0015] For this purpose, it is therefore provided that at least one temperature sensor with measuring contact with a surface of the ladle facing the ladle's scoop chamber, i.e., a surface that is in contact with the liquid metal during intended use, is arranged on the ladle. To uniformly determine the temperature for the entire melt in the ladle, the surface preferably has several, in particular evenly distributed, temperature sensors.

[0016] Alternatively or additionally, at least one sensor, for example in the form of a mandrel, penetrates the surface and thus has contact with the melt when used as intended.

[0017] Advantageously, the pouring ladle according to the invention therefore has, in particular in addition to the temperature sensor, a sensor that detects ladle movement and thus the pouring time. Such a sensor is, for example, an inclination sensor, a position sensor, or a tactile sensor.

[0018] Alternatively or additionally, a measuring or confirmation device can be provided, for example on the handle of the ladle, which detects a signal, for example in the form of pressing a button or key, which is actuated by the operator when working manually with the ladle.

[0019] In other words, it is preferred that the handle has a grip or holding section on which a confirmation unit assignable to the measuring unit is arranged for confirming a pouring process.

[0020] It has been shown that the ideal pouring time is not determined solely by the temperature of the melt, but rather influenced by other factors, particularly environmental factors. Therefore, it is advantageous if the ladle has an air pressure sensor and / or a humidity sensor, particularly on a surface of the ladle bowl and / or handle facing away from the melt.

[0021] In a preferred embodiment of the invention, the measuring unit has an evaluation unit (comprising a computing and / or microcontroller unit), a display unit and / or a memory unit, which is / are connected to the at least one sensor in a signal-conducting manner and is / are configured to store values measured by the at least one sensor in the memory unit continuously or at regular time intervals and / or to output them by means of the output unit. This enables the measured values to be processed within the ladle. Consequently, it is not necessary to provide a connection to an external control or memory unit during the entire process. In addition, an output unit enables the operator to monitor the process at precise times.Ultimately, depending on the design of the evaluation and output unit, this can be used to issue a warning when a predetermined critical value, in particular a predetermined temperature, is exceeded or undershot, as well as to control or regulate, in particular the pouring process.

[0022] The ladle according to the invention enables quality monitoring of the process and subsequent traceability of product defects in conjunction with process re-engineering. Furthermore, the measurement data can be archived.

[0023] Preferably, the evaluation, storage and / or display unit are arranged on the handle, in particular arranged away from the scoop, since this prevents or at least reduces the harmful effects of the high melting temperatures due to heat radiation.

[0024] Alternatively or additionally, the electrical components are preferably thermally shielded to prevent or at least reduce harmful influences.

[0025] The output unit is preferably configured to output a visual, haptic, and / or acoustic signal. For this purpose, a display, a vibration sensor, and / or a tone generator are provided, for example.

[0026] A particular advantage is that one position of the evaluation, storage, and / or output unit is freely movable. This allows for ergonomic positioning tailored to the individual operator.

[0027] The measuring unit is advantageously connected to an external storage unit and / or an external charging unit. This enables the collection and more complex evaluation of data from multiple processes. The connection is preferably detachable and is implemented or can be implemented, for example, in the form of an NFC (near field communication) interface and / or a plug-in connection such as a USB port. An induction unit can be provided for the charging unit as an alternative or in addition.

[0028] In particular, when combining the aforementioned embodiments and features, the pouring ladle according to the invention is particularly well suited to be integrated into an existing operational, in particular digital, infrastructure, wherein the pouring ladle according to the invention can also be used autonomously in the form of an island solution.

[0029] In a further preferred embodiment of the pouring ladle according to the invention, the ladle has full-surface insulation, particularly on a surface facing away from the interior of the ladle, i.e., on a side facing away from the liquid metal during intended use. This primarily ensures a homogeneous temperature distribution within the melt and slower and more even cooling of the melt. Furthermore, heat radiation into the environment and thus onto the operator and other parts of the measuring unit is reduced.

[0030] The insulation advantageously comprises a ceramic material, in particular a technical ceramic. Materials that comprise or consist of oxide or silicate ceramics, in particular calcium silicate, are preferred, for example the technical ceramic available as MonaLite®. Alternatively or additionally, the insulation comprises ceramic fibers. Suitable layer thicknesses for the insulation range from 5 to 40 mm, preferably 10 to 30 mm, more preferably 15 to 25 mm.

[0031] The material of the scoop requires high thermal stability, exhibits a high melting point, and is non-deformable. Suitable materials include cast iron, steel, and / or special plastics. In this case, a hybrid of cast iron and plastic has proven particularly suitable.

[0032] A further aspect of the invention is a method for producing a casting according to claim 8, in particular a metal casting, using a pouring ladle according to the invention at least according to claim 1. The method according to the invention comprises the following steps, which are carried out in the specified order.

[0033] First, the process involves scooping the material to be cast, i.e., filling the ladle with liquid metal or plastic by dipping the ladle into a molten mass. This is preferably located in a holding vessel.

[0034] The temperature of the melt in the ladle is repeatedly detected by a temperature sensor on the ladle.

[0035] The measured temperature is stored in a storage unit internal or external to the ladle and, in particular, also output. Preferably, the output is accurate to the second.

[0036] Advantageously, the pouring process is detected by actuating a confirmation unit or by a position and / or inclination sensor.

[0037] Alternatively or additionally, an acoustic, haptic and / or visual signal is emitted when a predetermined temperature (target temperature) of the molten metal in the scoop is reached and / or when such a temperature is exceeded or undershot.

[0038] The target temperature is determined, among other things, depending on ambient conditions such as air pressure and humidity determined by additional sensors, and the predetermined temperature is therefore re-determined when the ambient conditions vary.

[0039] The described embodiments can be advantageously combined with one another, unless otherwise stated in individual cases. The invention is described in more detail below using an exemplary figure. It shows: Figure 1 shows a schematic representation of a pouring ladle in a preferred embodiment of the invention.

[0040] Figure 1 shows a schematic representation of a pouring or scooping ladle 10 in a preferred embodiment of the invention. In the illustrated embodiment, the pouring ladle 10 is designed as an elongated, manually usable ladle 10. At one end, the pouring ladle 10 has a scoop 3. A handle 6 extends from this scoop 3.

[0041] In the embodiment shown, the scoop 3 has a hemispherical outer shape, which has a grooved spout on one edge. A plurality of temperature sensors 1 are arranged on a surface facing the interior of the half-shell, in this case, on the concave side of the scoop 3.

[0042] These temperature sensors are preferably evenly distributed. Depending on the type of sensor used, they are integrated into the surface in such a way that, when used as intended, they have direct or only indirect contact with the melt. In other words, the temperature of the melt is measured either by direct contact of the melt with the temperature sensors 1 or by over-measuring the temperature of the surface material on the concave side of the scoop 3. The scoop 3 also preferably has insulation 2 on a side facing away from the melt, i.e., on the convex outer side. The insulation 2 comprises a ceramic material, for example a ceramic oxide or a ceramic silicate, such as calcium silicate, which, due to its very low thermal conductivity, enables high thermal insulation even at high temperatures, such as those found in metallic melts.Alternatively or additionally, the insulation comprises two ceramic fibers and / or thermally insulating plastics. A mixture of calcium silicate and a thermally insulating plastic has proven particularly effective for use in light metal casting.

[0043] Depending on the material used, the insulation 2 is preferably applied as a coating over the entire surface of the scoop 3 with a layer thickness in the range of 5 to 40 mm, in particular 10-30 mm.

[0044] The scoop bowl 3 is preferably connected to the handle 6 via a detachable and / or rotatable or pivotable connection 9. For manual use, as is the case in the illustrated embodiment, the connection is detachable but fixed. In a movable version, the connection preferably has a locking mechanism.

[0045] The stem 6 and / or the connection 9 are preferably made of a material or at least coated with a material which has a low thermal conductivity.

[0046] The pouring ladle 10 has a measuring unit 4, which also includes the previously described temperature sensors 1. In addition to the temperature sensors, the measuring unit 4 preferably has further sensors, such as tactile sensors, inclination sensors for detecting ladle movement, and sensors for measuring environmental parameters, such as air pressure sensors and / or humidity sensors. These are arranged, for example, on the handle, i.e., at the other end of the stem 6 relative to the scoop 3. For storing and / or processing the measured values, the pouring ladle 10 can have an internal evaluation and storage unit 4, which is then preferably arranged in the stem 6. Alternatively, the measured parameters can be transferred directly to an external evaluation and storage unit.Such a transfer requires a signal-conducting connection, such as an electrical plug connection or a wireless connection 7, particularly based on NFC. The same applies to the electrical charging of the technological units of the measuring unit 4 and, in particular, to a storage unit 8. The storage unit 8 is preferably an external storage unit 8, as this enables the recording and, in particular, visual processing of the data backup.

[0047] In addition, the measuring unit 4 preferably includes an output unit, for example in the form of a display. Particularly during manual operation of the pouring ladle 10, the output unit is arranged directly on the pouring ladle 10 or in an area that is easily visually accessible to the operator, such as a monitor arranged at eye level or in AR glasses. List of reference symbols

[0048] 1Temperature sensors 2Insulation, insulating coating 3Ladle 4Measuring unit 4aDisplay / evaluation unit 5Confirmation unit / tactile sensor, push button 6Handle 7Signal-conducting connection, wireless connection, NFC connection 8External control unit 9Connection between ladle and handle 10Pouring or ladle

Claims

1. Ladle (10) for scooping and casting liquid metal, wherein the ladle (10) is a manual ladle (10), comprising a scoop bowl (3) and a handle (6) connected to the scoop bowl (3), which extends longitudinally from the scoop bowl (3) as a grip, wherein the scoop bowl (3) has a measuring unit (4) comprising at least one sensor for measuring at least one physical parameter, wherein at least one sensor is designed as a temperature sensor (1), characterized in that the temperature sensor (1) is arranged in contact for measuring to a surface of the scoop bowl (3) facing the scoop chamber of the scoop bowl (3).

2. Ladle according to claim 1, wherein the at least one sensor is to be selected from the group consisting of (air) pressure sensor, (air) humidity sensor, inclination sensor, position sensor and / or a tactile sensor.

3. Ladle according to one of the preceding claims, wherein the measuring unit (4) has an evaluation unit (4a), a display unit (4a) and / or a memory unit, which is or are connected to the at least one sensor in a signal-conducting manner and set up to save in the memory unit and / or to output by means of the display unit values measured by the at least one sensor continuously or at regular time intervals.

4. Ladle according to one of the preceding claims, in that the scoop bowl (3) has a plurality of, in particular evenly distributed, temperature sensors (1).

5. Ladle according to one of the preceding claims, wherein the scoop bowl (3) has an insulation (2) arranged over the entire surface, which is arranged, in particular on a surface facing towards or away from the interior of the scoop bowl (3).

6. Ladle according to one of the preceding claims, wherein the measuring unit (4) is connected or connectable to an external memory unit and / or an external charging unit, in particular via NFC (near field communication), induction and / or plug connection such as USB ports.

7. Ladle according to one of the preceding claims, wherein the handle (6) has a grip or holding section on which an actuation unit (5) assignable to the measuring unit (4) is arranged for confirming a casting process.

8. Method for producing a cast part using a ladle (10) at least according to claim 1, wherein the method comprises the following steps in the given order: a) filling the scoop bowl (3) with a liquid melting by dipping the scoop bowl (3) into a melting, b) repeatedly detecting the temperature of the melting in the scoop bowl (3) by means of the temperature sensor (1), c) saving the temperature in an internal or external memory unit in relation to the ladle (10).

9. Method according to claim 8, wherein the method comprises at least one of the steps: d1) detecting a casting process by actuating an actuation unit (5) or by a position and / or inclination sensor, d2) output of an acoustic, haptic and / or visual signal when a predetermined temperature of the melting in the scoop bowl (3) is reached.

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