Handling device for receiving a metal sample in a sample container

Abstract

Handling device (20) for receiving and aligning a sample (12) in a sample container (10), comprising a suction device (22) for drawing the sample (12) into the sample container (10), wherein the suction device is designed to be movable in at least one area; a gripping device (30), wherein the suction device (22) and the gripping device (30) are designed to be movable relative to each other; and a sensor device for detecting the negative pressure applied to the suction device (22).

Description

Field of invention

[0001] The invention relates to a handling device for receiving a metal sample in a sample container. State of the art

[0002] Metal samples in steel plants are taken from various locations within the plant and transported to the central laboratory via a pneumatic tube system. Upon arrival of the cylindrical tube container, the sample must be removed as quickly as possible so that it can be prepared for analysis. Sample preparation requires knowing the sample's position and orientation to ensure it can be securely placed and clamped in the milling cutter. This can be achieved, for example, using a rotary mechanism that aligns a hole or marker on the sample container with a light barrier. The aligned sample is then picked up by a gripper and, in a predefined movement, placed in the corresponding milling cutter in a predefined orientation.

[0003] The problem is that this requires the sample containers to be equipped with markers or holes, and the storage device that holds the sample container upon arrival must have a rotating mechanism and a light barrier or other sensor with which the sample container can be rotated and its orientation detected.

[0004] Furthermore, the duration of sample preparation plays a significant role for the steel producer. For certain samples, the molten steel must be kept at temperature until the analysis results are available, so that any necessary alloying can be carried out immediately. Maintaining this temperature requires large amounts of energy, which in turn is associated with high costs.

[0005] US2018 / 0207808 A1 discloses a holding device comprising a first suction cup capable of holding an object, a second suction cup capable of holding the object, wherein the second suction cup surrounds the first suction cup on a plane, and a movement mechanism that moves the first suction cup relative to the second suction cup in a first direction from the first suction cup to the object.

[0006] DE 10 2007 039 384 A1 discloses a handling device for multi-axis handling machines for handling different components with a carrier element to which at least one arm with at least one passive joint is attached, at the end of which a tool is arranged, wherein the at least one joint is assigned a clamping device for fixing it in a preselectable position and wherein in the unfixed state the at least one joint is freely movable. Description of the invention

[0007] One task is therefore to provide a handling device that can function with a rudimentary storage system, while simultaneously reliably detecting and managing the orientation of the sample container or at least the sample itself. This handling device should also ensure a reduction in sample handling time.

[0008] The problem is solved by a handling device according to claim 1 and a method according to claim 5. Further features that elaborate the invention are contained in the dependent claims.

[0009] A handling device according to the invention for receiving and aligning a metal sample in a sample container comprises a storage device for providing the sample container, a suction device for drawing the sample into the sample container, wherein the suction device is designed to be movable in a plane, and a sensor device for detecting the negative pressure applied to the suction device. With this handling device, the position of the metal sample can be easily detected without requiring a complex storage device. For example, light barriers and rotary devices are no longer necessary.

[0010] The handling device further comprises a gripping device, wherein the suction device and the gripping device are designed to be movable relative to each other. This extends the functionality of the handling device to the handling of other sample containers and samples without requiring additional kinematics.

[0011] The handling device preferably further comprises the sample container with the metal sample, wherein the sample container has a round, in particular circular, cross-section and the sample is arranged radially around the center of the sample container on a predetermined circumference. This arrangement of the sample in the sample container enables efficient detection of the sample orientation. Preferably, a longitudinal axis of the sample, in particular an axis through a projection on the sample edge, is aligned with the center of the sample container. This further facilitates the detection of the orientation.

[0012] The suction device is preferably rotatable, in particular about a longitudinal axis of a suction opening of the suction device. This allows the sample to be rotated into a desired position for the subsequent steps in sample preparation.

[0013] An inventive method for determining the position of a sample in a sample container comprises the steps a) moving a suction device to a first position in the sample container, b) applying a vacuum to the suction device and detecting the pressure with a sensor device, and c) evaluating the detected pressure to determine the position and orientation of the sample in the sample container. With this method, the position and, in particular, the orientation of the metal sample can be detected without additional elements such as a light barrier or push button.

[0014] Preferably, after evaluating the measured pressure, a second position is approached, and in particular further positions, and steps b) and c) are performed at the second position and any further positions. This increases the accuracy of the position and orientation determination. The positions approached are preferably located on a circular path, particularly on a circular path formed around the center of the sample container.

[0015] Preferably, in this method, the distance between the positions is reduced after a predetermined pressure has been detected in steps b) and c). In particular, the distance is reduced repeatedly. This allows the accuracy of the position determination to be increased as desired.

[0016] Preferably, a measured target pressure is achieved when the suction device rests on the edge of the sample, so that the suction device is neither blocked nor completely exposed. By positioning it at the sample edge, a clearly distinguishable position of the suction device and thus the orientation of the sample can be determined.

[0017] A longitudinal axis of the sample, in particular an axis through a projection at the sample edge, is preferably aligned with the center of the sample container. This further facilitates the positioning of the sample.

[0018] The aforementioned methods are preferably carried out using one of the aforementioned handling devices. Brief description of the characters Fig. Figure 1 shows a longitudinal section through a pneumatic tube system with sample containers; Fig. 2a shows a cross-section through a sample container; Fig. 2b shows one of the sample containers made of Fig. 2a corresponding sample; Fig. 3a shows a cross-section through a sample container; Fig. 3b shows one of the sample containers made of Fig. 3a corresponding sample; Fig. 4a shows a cross-section through a sample container; Fig. 4b shows one of the sample containers made of Fig. 4a corresponding sample; Fig. Figure 5a shows a side view of a handling device; Fig. Figure 5b shows a top view of the handling device made of Fig. 5a; Fig. Figure 6 shows a circular path with several, in particular initial, starting points; and Fig. Figure 7 shows a procedure in which the distances between the approach points are reduced. Description of preferred embodiments

[0019] Fig. Figure 1 shows a pneumatic tube system 6, which transports metal samples from a sampling point to the analysis device within a pneumatic tube system. The pneumatic tube system comprises a main body 8 and a sample container 10 in which the sample 12 is removably embedded. Furthermore, the pneumatic tube system 6 is equipped with a cover 7, which holds the sample 12 in the recess 14. The cover 7 acts as a stop, positioned at a distance in front of the recess 14 that is less than the width of the sample 12, thus preventing the sample 12 from falling out of the recess.

[0020] In Fig. Figure 2a shows a sample container 10 in a top view. A recess 14 is provided in the base 13 of the sample container 10, into which a metal sample is inserted for transport in the pneumatic tube system. The sample preferably has a slight amount of play, e.g., 0.1 mm - 0.5 mm, so that it is held securely in the sample container 10 in conjunction with the lid 7, as described, but can also be removed from the recess 14 without requiring much force. The sample is in Fig. 2b. The recess 14 is preferably designed such that the central axis of the recess passes through the center of the sample container 10, which is shown here as circular. The sample 12, which is inserted into the sample holder 10, essentially corresponds to the recess 14. It may have a small pin 11 at one end. The recess may also be adapted to this pin 11 and include a corresponding recess projection 15, which extends into the Fig. 3a and Fig. 4a is shown. Sample 12 is in Fig. 2 elongated and with circular ends and extends over most of the sample container bottom 13.

[0021] In Fig. Figure 3a also shows a sample container 10 in a top view, in the base 13 of which a recess 14 is provided, into which a metal sample is placed for transport in the pneumatic tube system. Essentially, the features are the same as those of the previously described sample container 10. Fig. 2a. The sample (see Fig. 3b) and accordingly, the recess also has a circular shape, with the central axis M of the recess 14 again preferably passing through the center of the sample container 10. Here, the recess 14 has a recess projection 15 adapted to the pin 11 of the sample 12. The recess 14 extends over approximately 2 / 3 of the diameter of the circular sample container 10.

[0022] The same applies to those in the Fig. 4a and Fig. 4b shown sample container 10 and sample 12, where sample 12 is an intermediate form between the elongated sample 12 made of Fig. 2 and the circular sample 12 from Fig. 3. Here too, the sample has a pin 11, which is also formed as a projection 15 in the recess 14.

[0023] Fig. Figure 5a shows a side view of the handling device 20. The handling device 20 is designed to be linearly movable in at least two degrees of freedom via a motion mechanism, so that every approach point in a plane is reachable (x and y axes). Preferably, the movement options can also include a third linear degree of freedom (z axis) and / or one to three rotations about the x, y, and z axes. This movement of the handling device 20 is preferably achieved via an arm 21, which is driven by a suitable motor. Preferably, this is a robot arm movable in all six degrees of freedom.

[0024] Fig. Figure 5b shows a side view of the handling device 20. The handling device 20 comprises a suction device 22 equipped with a suction nozzle 24. The suction nozzle 24 has an opening, preferably with a diameter between 15 mm and 25 mm. The suction device 22 is preferably connected via a hose 26 to a vacuum device, such as a pump, which generates the vacuum with which the suction device 22 can then draw in the samples. Furthermore, the handling device 20 comprises a sensor device that can measure the vacuum applied to the suction nozzle 24. The sensor device need not be integrated directly into the handling device 20, but can, for example, be provided on a control device that is also used to move the handling device 20, or on the aforementioned vacuum device.

[0025] The suction device 22 is rotatable, in particular about its own central axis of the suction nozzle 24. The rotation is generated by a stepper motor or a servo motor 28, which is connected to the suction device 22 via a belt 29. The suction device, or even just the suction nozzle, is rotatably mounted for this purpose. The motor 28, the suction device, and the other components of the handling device 20 are attached to a frame 25, which acts as a kind of housing. Finally, the handling device 20 also includes a gripping device 30, with which a pneumatic tube system 6 can be picked up and processed on the main body 8 in a conventional manner. The gripping device 30 is in Fig. Figure 5b shows the grippers in the open and closed positions. The grippers are driven by a motor 23, enabling the gripping movement to be performed.

[0026] The sample container 10 is positioned in a storage unit for handling by the handling device 20. The sample container 10 is oriented such that its open top surface is parallel to the plane in which the handling device 20 moves. This ensures that the suction nozzle 24 is perpendicular to the surface of the sample 12, allowing it to draw in and collect the sample.

[0027] The pneumatic tube system 6 is preferably positioned vertically in the storage unit, with the lid 7 on top. The lid is then removed, which is usually done automatically. This leaves the sample container 10 with its open side facing upwards, allowing the handling device 20 to move the suction device 22 over the open sample container 10. To pick up the sample, the suction device is lowered and a vacuum is applied to the suction nozzle. Lowering is preferably carried out by means of the arm 21, but it is also possible to design the suction device 22 to be movable relative to the rest of the handling device 20, so that the suction device can be lowered and raised independently. A sensor detects the vacuum and can use this detection to determine whether the suction nozzle 24 is on or next to the sample 12, thus allowing the position of the sample's edge to be determined.It is also possible to define different limit pressures in the sensor and thereby detect whether the suction nozzle 24 is located on the edge of the sample 12. If the suction nozzle is located on the edge of the sample 12, the precise position of the sample 12 can be tracked; that is, the suction nozzle 24 is moved onto the sample, suction is applied, and it is removed from the recess 14. The sample can then, if necessary, be rotated into a desired position using the suction device 22 and transferred to a sample preparation unit. The sensor assembly can be mounted directly on the frame 25 of the handling device 20 or at another location, for example, on the control unit or the motor of the arm 21.

[0028] To determine the position of sample 12, the handling device 20 follows a path adapted to the possible positions of sample 12 in the sample container 10 and suctions the sample 12 at predetermined points along this path. The path is shown by way of example in Fig. Figure 6 shows the possible positions P1-P5. Here, this path is a circular path because the sample 12 is placed in the sample container 10 on a circular path around the center of the sample.

[0029] In Fig. Figure 7 shows an example of how the method for determining the position and preferably also the orientation of the sample can be carried out. In this example, the sample is positioned with its central axis at approximately 288°. First, the suction device moves to points P1-P4 and attempts to draw in the sample 12. Due to the negative pressure conditions, the sensor device detects that no sample 12 is located at these positions. At point P5, the sample 12 is drawn in by the suction nozzle 24, and the opening is blocked. This confirms that the suction nozzle 24 is positioned above the sample 12. The sample 12 can then be removed from the recess 14 and placed in the sample preparation unit.

[0030] The goal is not only to find the approximate position of sample 12, but also its precise position and orientation. To achieve this, the distance between positions P4 and P5 is divided into further segments, thus determining additional positions to be approached: P4-1, P4-2, and P4-3. At position P4-3, it is again confirmed that sample 12 completely covers the suction nozzle. The segment between P4-2 and P4-3 is then divided into smaller segments, and the system approaches these new positions until, at one position—in this case, P4-2-1—the suction nozzle 24 is only partially obscured by sample 12, and the sensor detects a corresponding vacuum. This confirms that the suction nozzle 24 is located on the edge of sample 12.The geometry of the sample and the scanning direction of positions P also determine the orientation of the sample, especially when the central axis of the recess 14, and thus also of the sample 12, is directed towards a predefined point, in this case the center of the sample container. In this way, the edge of the sample can be precisely located by continuously reducing the search interval, with a localization accuracy of 4°–6°, and especially 4.5°, appearing optimal in terms of accuracy and effort.

[0031] After the position and orientation of sample 12 have been determined, the handling device 20 removes the sample 12 after centrally positioning the suction nozzle 24 above the sample 12. Preferably, it is then rotated by the previously determined angle and placed in the next sample preparation unit in this positioned and oriented manner. Reference symbol list 6 pneumatic tube system 10 sample containers 11 pen 12 Sample 13 Sample container bottom 14 recess 20 Handling device 21 Arm 22 Suction device 23 Engine 24 suction nozzle 25 frames 28 stepper motor 29 belts 30 Gripping device P positions M Central axis

Claims

Handling device (20) for receiving and aligning a sample (12) in a sample container (10), comprising a suction device (22) for drawing the sample (12) into the sample container (10), wherein the suction device is designed to be movable in at least one area; a gripping device (30), wherein the suction device (22) and the gripping device (30) are designed to be movable together; and a sensor device for detecting the negative pressure applied to the suction device (22). Handling device (20) according to one of the preceding claims, further comprising a storage device for providing the sample container (10) and the sample container (10) with sample, wherein the sample container (10) has a round cross-section and the sample is arranged radially around the center point of the sample container (10) on a predetermined circumference. Handling device (20) according to claim 2, wherein a longitudinal axis (M) of the sample (12), in particular an axis through a pin (11) at the sample edge, is aligned with the center point of the sample container (10). Handling device (20) according to one of the preceding claims, wherein the suction device (22) is rotatable, in particular rotatable about a longitudinal axis of a suction opening of the suction device (22). Method for determining the position of a sample in a sample container, comprising the steps: a) moving a suction device (22) to a first position (P1) in the sample container; b) applying a vacuum to the suction device (22) and detecting the pressure with a sensor device; characterized by c) evaluating the detected pressure to determine the position and orientation of the sample in the sample container, wherein, after evaluating the detected pressure, a second position (P2) is approached, and in particular further positions (P), and steps b) and c) are carried out at the second position and possible further positions. Method according to claim 5, wherein the positions lie on a circular path, which is formed in particular around the center of the sample container. Method according to claim 5 or 6, wherein the distance between the positions is reduced, in particular repeatedly reduced, after detecting a predetermined pressure in steps b) and c). Method according to one of claims 5 to 7, wherein a detected target pressure is achieved when the suction device rests on the edge of the sample, such that the suction device is neither blocked nor completely exposed. Method according to one of claims 5 to 8, wherein a longitudinal axis of the sample, in particular an axis through a projection at the sample edge, is aligned with the center of the sample container. Method according to any one of claims 5 to 9, carried out with a device according to claims 1 to 4.

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