CN119098577A - Casting machine and casting method - Google Patents

Abstract

The invention relates to a casting machine and a method for pouring a melt into a casting mold, wherein at least one casting mold (24) is accommodated on a support of the casting machine, wherein the melt (34) is filled into the casting mold by means of a crucible (25) of the casting machine, wherein the casting mold is moved by means of a pivoting device of the casting machine when the melt is filled into the casting mold and is tilted about an axis (32), wherein the crucible is moved by means of a robot of the casting machine when the melt is filled into the casting mold, wherein the movement of the casting mold when the melt is filled into the casting mold is detected by means of a sensor device of the casting machine, wherein the crucible is moved by the robot as a function of the movement of the casting mold.

Description

Casting machine and casting method

Technical Field

The invention relates to a casting machine and a method for pouring a melt into a casting mould, wherein at least one casting mould is accommodated on a support of the casting machine, wherein the melt is guided into the casting mould by a crucible of the casting machine, wherein the casting mould is moved by a pivoting device of the casting machine when the melt is filled into the casting mould and is tilted about an axis, wherein the crucible is moved by a robot of the casting machine when the melt is filled into the casting mould.

Background

Such casting machines and methods are well known in the art, wherein liquid metal is always filled into the mould during casting until the mould or the cavity of the mould is completely filled. After solidification of the melt, the subsequently formed component may be shaped or removed from the mold. The casting mold may be a permanent mold or a disposable mold, such as a permanent mold or a sand mold. Importantly, when the melt is filled into the mold (which can be accomplished by the crucible), the mold moves or tilts about the axis. For this purpose, the casting mould is arranged on a movable support of the casting machine. The support of the casting machine is designed such that the casting mould can be moved by a pivoting device or tilted about an axis. By tilting the mould when pouring the melt, the mould can be completely filled with metal, depending on the shape of the cavity in the mould, without cavitation, cold flow forming in the mould. Contaminants, and the like.

The melt is poured into the mold or gate of the mold by a robot that fills the melt into the crucible, positions it at or above the gate, and tilts the crucible in such a way that the melt flows into the gate in the desired amount. The robot may be, for example, a multi-axis robot having a robot arm with a crucible secured thereto. The robot may fill the crucible in the melt pool and move it to the mold. The robot is programmed here regularly such that the robot arm with the crucible follows the pivoting movement of the mold, so that even if the mold is tilted, the melt always fills the gate or can flow into it. Alternatively, an additional fixed crucible or melt reservoir may be provided on the casting mold, the melt reservoir being filled with liquid metal to the crucible by a robot. When the mold is tilted, the melt flows from a melt reservoir, which is firmly fastened to the mold, into the gate of the mold.

However, as already indicated, the melt must have a significantly higher temperature, because there is a temperature loss when the melt is decanted. In addition, the decanting step also extends the casting cycle. The formation of oxide layers on the surface of the melt and the introduction of oxides are promoted, so that the quality of the product produced by casting is deteriorated. Furthermore, the use of robots to position the crucible directly at the gate is difficult to achieve, since the movement of the crucible or robot must always be coordinated very precisely with the position of the crucible or gate firmly on the casting mold.

Disclosure of Invention

The object of the present invention is therefore to provide a method for pouring a melt into a casting mould and a casting machine which enable high-quality products to be cast in a cost-effective manner.

The object is achieved by a method having the features of claim 1 and a casting machine having the features of claim 13.

In the method according to the invention for pouring a melt into a casting mould, at least one casting mould is accommodated on a support of a casting machine, wherein the melt is filled into the casting mould by means of a crucible of the casting machine, wherein the casting mould is moved by means of a pivoting device of the casting machine when the melt is filled into the casting mould and is tilted about at least one axis, wherein the crucible is moved by means of a robot of the casting machine when the melt is filled into the casting mould, wherein the movement of the casting mould when the melt is filled into the casting mould is detected by means of a sensor device of the casting machine, wherein the crucible is moved by means of the robot in dependence on the movement of the casting mould.

In the method according to the invention, it is provided that the casting machine tilts or pivots the casting mould about at least one axis when pouring the melt into the casting mould, i.e. during the casting process. The metal or melt flowing into the mould can thereby continuously fill the mould without causing uncontrolled filling of the mould cavity in the mould, in which case. In order to prevent that the melt has to be transferred into the casting mould by means of a robot, which causes an increase in the melt due to turbulence, and that the melt has to be provided at a high temperature, the sensor device of the casting machine now detects the movement of the casting mould when the melt is poured into the casting mould according to the invention. This allows the crucible to be moved by the robot in accordance with the detected movement of the mould and thus relatively accurately track the tilting movement of the mould. In the simplest embodiment, the casting mould is inclined about at least one axis. The robot of the casting machine can then be designed such that the crucible can be moved by the robot in at least two degrees of freedom. The crucible can then be positioned directly at or over the gate of the mold, eliminating the need to transfer the melt into the crucible located on the mold. This eliminates the need to raise the temperature of the melt significantly and eliminates the transfer step that would otherwise lengthen the casting process. The key to performing this method is a sensor device that detects the movement of the mold so that the robot can position the crucible locally and accurately in accordance with the movement of the mold and follow the movement.

The crucible may be stationary relative to the mold as the mold is tilted about an axis, or the crucible may be tilted about another axis. For filling the melt into the mold or gate, a crucible containing the melt or liquid metal may be positioned at the gate in the mold. In a first embodiment of the method, it may be provided that the crucible is firmly fixed relative to the mold or that the crucible is moved with the movement of the mold by the robot in such a way that no relative movement of the mold and the crucible takes place. Due to the movement of the mold, the crucible moves with it, so that the melt can be poured into the gate by this movement. According to another embodiment, the crucible may be tilted about another axis. This means that during movement of the mold when pouring the melt into the gate, the crucible can be moved relative to the mold so that more or less melt can be poured into the gate than a stationary crucible. The melt flow rate or the melt volume flow rate can thus be adjusted, for example, as a function of the shape of the mold cavity. The casting process can better adapt to the shape of the product.

Tilting of the mould about the axis and/or movement of the robot may be controlled using the control means of the casting machine. The control means may comprise or be formed by means for data processing, for example a computer or a programmable logic controller. As part of the casting process, the control device may then manipulate, for example, a motor, actuator, or other implement, such that the casting mold tilts or pivots about at least one axis. Furthermore, the control device may also operate the robot such that the crucible is moved by the robot according to the movement of the mold. Sensor means may be used here to determine the movement or position of the casting mould.

The absolute position, the rotation angle and/or the rotation speed of the axis of the mould and/or of the movement of the crucible can be determined using the sensor means. The pivoting means may have sensor means and the sensor means may comprise, for example, a rotary encoder or other suitable sensor on the respective shaft. These sensors can then determine the actual position of the axis of the mould or the tilting angle of the mould and thus the position of the gate of the mould independently of the drive of the pivoting means for tilting the mould. It is also advantageous if the rotational speed of the casting mold can be determined by means of a sensor device, since this makes it possible to adapt the rotational speed of the crucible by means of the movement of the robot, and in particular the acceleration of the casting mold during tilting, by means of the control device.

During filling, the adjusting means of the control device can adjust the movement of the crucible as a reference variable depending on the absolute position, the rotation angle or the rotation speed of the casting mold. The adjusting device can be designed as an adjusting system in the control device for adjusting the drive of the robot such that the crucible is moved in the desired type and manner during the casting process. Furthermore, it can be provided that the adjusting device adjusts the inclination of the casting mold, for example, as a function of the rotational speed. The adjusting device may then have a further adjusting system.

By means of the sensor device, a touching contact between the mold and the crucible can be detected when the melt is poured into the mold. By detecting touching contact, movement of the mold can also be detected when the melt is poured into the mold. This allows the crucible to follow the movement of the casting mold particularly precisely. The sensor herein may be any suitable sensor for detecting touch contact.

The touching contact between the mold and the crucible may be made in a predetermined contact area, preferably adjacent to the gate of the mold. It may be provided that the crucible is moved by the robot to the mould such that a touching contact between the mould and the crucible occurs before the melt is poured into the mould. The contact areas may be formed such that specifically provided contact surfaces, protrusions, recesses, certain geometries corresponding to each other, etc. are formed on the casting mould and/or the crucible. If the contact area is formed at the gate or in an area immediately surrounding the gate, it is ensured that the crucible can be positioned at the correct position at the gate.

The sensor may detect force and/or torque during contact. To this end, the sensor may be positioned on the robot, crucible or mold. A sensor may be used to measure force or torque so that the crucible can track the mold by a robot based on the measured dimensions. Whereby a relatively precise adjustment of the movements of the robot is possible. Alternatively, a sensor may be used to measure the direction of force or torque.

Alternatively, the relative distance between the mould and the crucible can be detected by a sensor of the sensor device, whereby the crucible and the mould can be moved without contact during filling of the melt into the mould. This means that the crucible and the mould do not touch each other when pouring the melt and always form a relative distance, which is preferably always the same size. Thus, the sensor may be designed to detect the proximity of the crucible to the mold. During casting, the crucible may initially be moved to the mold by a robot until a desired relative distance is reached. When the mould is tilted, the robot can now track the movement of the crucible to the mould so that the relative distance is always the same. This has the advantage that there is no mechanical contact between the crucible and the mould, which prevents possible damage.

The adjustment means of the control means may adjust the movement of the crucible during filling in dependence on the relative distance, force and/or torque. The relative distance, force and/or torque may then be reference variables, according to which the adjusting device adjusts the movement of the robot or crucible. This ensures that the crucible is always in the desired position during casting.

The crucible may be releasably secured to the casting mould, wherein the casting mould may then be moved, whereby the movement caused on the robot can be detected by a sensor of the sensor arrangement, wherein the crucible is able to track the movement of the casting mould by the robot. The releasable fastening may be formed simply by a form-fitting connection between the crucible and the mould, for example by a robot hooking the crucible to the mould. However, the robot remains firmly connected to the crucible at all times, so that a subsequent movement of the casting mold also leads to a movement of the robot. In this case, the sensor of the sensor device is a component of the robot, by means of which the force on the robot or crucible caused by the movement of the casting mould is detected. Then, depending on the force exerted on the robot by the crucible, the robot's drive may move the robot so that the crucible follows the movement of the mold. The advantage here is that no particularly complex programming of the robot or the control device is required. Here, the robot with the crucible is only required to move to a point in space to connect it to the mold.

The control means may use sensor means to determine the volume of melt located in the crucible. In principle, the control device can also calculate the total melt volume in the casting mould in the respective time segment. Sensor means may initially be provided to measure the weight of the crucible. By reducing the weight during casting, the melt volume can be recalculated at any time. This is also particularly advantageous if the volume of the mould cavity is known. The control device may then also determine the point in time until the casting process is completed or the period of time for pouring the melt into the mold is completed. This may further speed up the casting process.

During filling, the casting mould can be tilted about a second axis by means of a pivoting device, wherein the axis is designed to extend transversely with respect to the second axis. It can thus be provided that the casting mould is tilted or rotated about an axis or a first axis and about a second axis when pouring the melt. Whereby the two axes may be designed or arranged to extend transversely with respect to each other, the mould may be moved in two planes, resulting in a movement in three dimensions during filling of the melt. This allows the movement of the mould to be adapted solely to the cavity formed in the mould during filling of the melt. Even products with complex geometries can be cast with high quality. When pouring the melt into the mould, the melt can be guided by moving the mould to a desired flow direction, which can be varied during the casting process or filling according to the shape of the product and which can be adapted to the shape of the product. Melt channels formed in the casting mold are also contemplated herein. The casting process can be designed such that the cavity of the casting mold is filled smoothly and completely, so that air inclusions and cold flow tendencies and contamination of the product by oxides are avoided. In addition, the placement of the cavity within the mold is no longer necessarily limited to the optimal location of the gate on the mold. Since the mould can be moved in two degrees of freedom, the arrangement of the mould cavity is more flexible. Depending on the shape of the product to be cast, the dimensions of the mould can be made smaller, since the arrangement of the cavities in the mould can be chosen in the most space-saving manner possible.

The casting machine according to the invention for pouring a melt into a casting mould comprises a holder on which at least one casting mould and a crucible are accommodated, wherein the casting mould can be filled with the melt by means of the crucible, wherein the casting machine comprises a pivoting device by means of which the casting mould can be moved and tilted about an axis when the melt is filled into the casting mould, wherein the casting machine comprises a robot by means of which the crucible can be moved during the filling of the melt into the casting mould, wherein the casting machine has a sensor device by means of which the movement of the casting mould can be detected during the filling of the melt into the casting mould, wherein the crucible can be moved by means of the robot in accordance with the movement of the casting mould. Regarding the advantageous effects of the casting machine according to the invention, reference is made to the description of the advantages of the method according to the invention.

The sensor device may comprise at least one sensor, in particular a force sensor, a displacement sensor, a rotation sensor, an image sensor, an induction sensor, a capacitance sensor, a near field sensor, an ultrasonic sensor, a radar sensor, a magnetic sensor. In principle, the sensor may be any sensor suitable for detecting movement of the casting mold during filling of the melt. Furthermore, the sensor device may comprise a plurality of sensors of the same or different types. The force sensor may be a strain gauge or a piezoelectric sensor. The displacement sensor may be an optical sensor or a rotary encoder. The image sensor may be constituted by, for example, an image capturing camera. The near field sensor may be formed by an inductive sensor or a capacitive sensor. An ultrasonic sensor or a radar sensor capable of easily measuring a distance may also be used. The magnetic sensor is also suitable for measuring proximity or touch contact.

The sensor may be located remote from the mould, on the crucible or on the robot, preferably adjacent to the gate or directly on the gate. It is advantageous if the sensor is not arranged directly on the mould, since the sensor is independent of the mould. The sensor may also be arranged and aligned on the stand of the casting machine such that it is positioned adjacent the runner, for example a camera with an optical detection range aimed at the runner. A camera may then be used to determine the relative distance between the gate and the crucible. Alternatively or additionally, the sensor may also be arranged directly on the casting mold or crucible. Contact of the crucible and the mold in the gate region can then be detected particularly easily.

The robot may be a multi-axis articulated arm robot. Such a robot, for example a robot with three degrees of freedom, is readily and relatively cheaply available on the market, so that it is not necessary to produce a robot that can be used exclusively for the casting machine.

Further advantageous embodiments of the casting machine result from the characterizing features of the dependent claims related to method claim 1.

Drawings

Preferred embodiments of the present invention are explained in more detail below with reference to the accompanying drawings.

In the accompanying drawings:

fig. 1 shows a perspective view of a crucible of a first embodiment;

FIG. 2 shows a schematic view of a possible movement of the crucible of FIG. 1;

fig. 3 shows a perspective view of a crucible of a second embodiment;

FIG. 4 shows a schematic view of a possible movement of the crucible of FIG. 3;

FIGS. 5a-5e show schematic views of a method sequence for filling a casting mold according to a first embodiment;

Fig. 6a-6e show a schematic diagram of a method sequence for filling a casting mould according to a second embodiment.

Detailed Description

Fig. 1 and 2 schematically illustrate a first embodiment of a crucible 10 of a casting machine (not shown here) and a method performed therewith. The crucible 10 is coupled by a receptacle 11 to a robot arm (not shown here) of the casting machine and can be pivoted about at least one axis 12 via the robot arm. As crucible 10 pivots about axis 12, melt located in receiving space 13 of crucible 10 may enter a gate (not shown here) of a mold via pouring collar 14. Furthermore, an abutment surface 15 is provided on the pouring collar 14 of the crucible 10, via which the crucible 10 can contact a casting mould 16, which is schematically shown in fig. 2. A gate (not shown here) is formed on the mold 16, and the crucible 10 is pivoted about the axis 12 by a robotic arm or robot to fill the melt into the gate of the mold 16. In the region of the contact surface 15, a sensor (not shown here), in particular a force sensor of a sensor device of the casting machine, is provided, with which contact between the crucible 10 and the casting mold 16 can be detected. By means of the control of the casting machine, the crucible 10 can be moved by the robot in accordance with touching contact or movement of the casting mould 16. This ensures that the crucible 10 is always in contact with the mold 16 and that the melt can be filled into the mold 16 in the desired manner during the casting process.

The outline of fig. 3 and 4 shows a crucible 17, which is connected to a robot arm (not shown here) via a receptacle 18. Crucible 17 can be tilted about axis 19 and forms a receiving space 20 for the melt. In contrast to the crucible shown in fig. 1 and 2, a sensor 21 is provided here for detecting a force. If the mould 22, which is now schematically shown in fig. 4, is in contact with the crucible 17, the sensor 21 will detect the force regardless of the exact position on the abutment surface 23 of the crucible 17. The force detected by the sensor device of the casting machine can also be used here to move the crucible 17 by the robotic arm in accordance with the movement of the casting mold 22.

The outline of fig. 5a to 5e shows a casting process, in which a casting mold 24 and a crucible 25 are schematically shown. The mold 24 is formed of an upper mold portion 26 and a lower mold portion 27. A gate 28 is also formed on the mold 24 with a melt channel 29 leading to a runner 30 of a cavity 31. The casting mold 24 is designed to be tiltable about at least one axis 52 by a pivoting device (not shown here) of the casting machine. Crucible 25 may also be designed to be tiltable about axis 33. To this end, the crucible may be moved while the melt 34 is poured into the mold 24 by a robot of the casting machine (not shown here). Movement of the crucible 25 may occur in at least two degrees of freedom.

Fig. 5a to 5e schematically show a casting mould 24 with a crucible 25 during different time sections according to an embodiment of the casting process. During casting, crucible 25 is always in contact with mold 24 at gate 28. Starting from the starting position shown in fig. 5a, the crucible 25 is aligned relative to the casting mold 24 by a robotic arm, not shown here, and positioned on the gate 28. The robot arm and/or crucible 25 is equipped with a sensor device, which is not shown in more detail and corresponds to the functional principle shown in fig. 4. By means of the sensor device, the force on the crucible 25, in particular the force of the melt 34 located in the crucible on the crucible 25 and the pressure on the casting mold 24, can be detected.

As shown in fig. 5b, mold 24 is now tilted about axis 32 such that melt 34 in crucible 25 flows toward gate 28 and continues to flow into cavity 31, as shown in fig. 5 c. Tilting movement of the mold 24 results in a spatial displacement of the gate 28, wherein the crucible 25 always follows the gate 28 by the robotic arm. At the same time, crucible 25 is tilted about axis 33. The fact that crucible 25 is resting on mold 24 can be determined by a sensor device. With the continued pivoting movement according to fig. 5d, the crucible 25 is subjected to a laterally acting force via the casting mold 24, which force is also detected via the sensor device. As shown in fig. 5e, mold 24 eventually fills completely with melt 34.

Fig. 6a to 6e schematically show a casting mold 35 with a crucible 36 according to another embodiment of the casting process during different time sections. In contrast to the illustrations in fig. 5a to 5e, the sensor arrangement here comprises a sensor 37 arranged directly on the crucible 36. This results in the construction of the mold 35 and crucible 36, as shown schematically in fig. 2. By means of the sensor 37, a direct touch contact between the casting mould 35 and the crucible 36 can be detected. Here, as can be seen from fig. 6a to 6c, the mold 35 is tilted about the axis 38 and the crucible 36 is tilted about the axis 39 simultaneously during the casting process. The crucible 36 here always tracks the casting mold 35. This is accomplished by a control device that moves the crucible 36 to maintain touch contact. This is also the case throughout the casting process until the melt 40 is finally poured into the mold 35.

Claims (16)

1. A method for pouring a melt into a casting mould, wherein at least one casting mould (16, 22, 24, 35) is accommodated on a support of a casting machine, wherein the melt (34, 40) is filled into the casting mould by means of a crucible (10, 17, 25, 36) of the casting machine, wherein the casting mould is moved by means of a pivoting device of the casting machine when the melt is filled into the casting mould and is tilted about an axis (32, 38), wherein the crucible is moved by means of a robot of the casting machine when the melt is filled into the casting mould,

The method is characterized in that the movement of the mold is detected by a sensor device of the casting machine when the melt is filled into the mold, wherein the crucible is moved by a robot in accordance with the movement of the mold.

2. The method according to claim 1, characterized in that the crucible (10, 17, 25, 36) is stationary with respect to the casting mould (16, 22, 24, 35) when the casting mould is tilted about an axis (32, 38) or the crucible is tilted about another axis (12, 19, 33, 39).

3. Method according to claim 1 or 2, characterized in that the tilting of the casting mould (16, 22, 24, 35) about the axis (32, 38) and/or the movement of the robot is controlled by the control device of the casting machine.

4. A method according to claim 3, characterized in that the absolute position, the rotation angle and/or the rotation speed are determined by sensor means for the movement of the axis (32, 38) of the casting mould (16, 22, 24, 35) and/or the crucible (10, 17, 25, 36).

5. Method according to claim 4, characterized in that the adjustment means of the control device adjust the movement of the crucible (10, 17, 25, 36) during filling in dependence on the absolute position, the rotation angle and/or the rotation speed of the casting mould (16, 22, 24, 35) as reference variables.

6. Method according to any of the preceding claims, characterized in that a touching contact between the mould (16, 22, 24, 35) and the crucible (10, 17, 25, 36) during filling of the melt (34, 40) into the mould is detected by a sensor (21, 37) of the sensor device.

7. Method according to claim 6, characterized in that the touching contact between the mould (16, 22, 24, 35) and the crucible (10, 17, 25, 36) is in a predetermined contact area (15, 23), preferably adjacent to the gate (28) of the mould.

8. Method according to claim 6 or 7, characterized in that the sensor (21, 37) detects force and/or torque during touch contact.

9. A method according to any one of claims 3-5, characterized in that the relative distance between the mould and the crucible is detected by means of a sensor of the sensor device, wherein the movement of the crucible and the mould takes place without contact during filling of the melt into the mould.

10. Method according to claim 8 or 9, characterized in that the adjustment means of the control means adjust the movement of the crucible during filling in accordance with the relative distance, force and/or torque.

11. A method according to any one of claims 3 to 5, characterized in that the crucible is releasably secured to the mould and the mould is subsequently moved, whereby the movement caused on the robot is detected by means of a sensor of the sensor device, wherein the movement of the mould is tracked by the robot.

12. A method according to any one of claims 3 to 11, characterized in that the control device determines the melt volume in the crucible (10, 17, 25, 36) by means of a sensor device.

13. A casting machine for pouring a melt into a casting mould, wherein the casting machine comprises a support on which at least one casting mould (16, 22, 24, 35) and a crucible (10, 17, 25, 36) are accommodated, wherein by means of the crucible the melt (34, 40) can be filled into the casting mould, wherein the casting machine comprises a pivoting device by means of which the casting mould is movable when filling the melt into the casting mould and tiltable about an axis (32, 38), wherein the casting machine comprises a robot by means of which the crucible is movable during filling of the melt into the casting mould,

The casting machine is characterized in that it has a sensor device by means of which the movement of the casting mold can be detected during the filling of the melt into the casting mold, wherein the crucible can be moved by means of a robot in accordance with the movement of the casting mold.

14. Casting machine according to claim 13, characterized in that the sensor means comprise at least one sensor (21, 37), in particular a force sensor, a displacement sensor, a rotation sensor, an image sensor, an induction sensor, a capacitance sensor, a near field sensor, an ultrasonic sensor, a radar sensor, a magnetic force sensor.

15. Casting machine according to claim 14, characterized in that the sensor (21, 37) is located remote from the casting mould (24), on the casting mould (35), on the crucible or on the robot, preferably adjacent to the gate or directly at the gate (28).

16. The casting machine of any one of claims 13 to 15, wherein the robot is a multi-axis articulated arm robot.