System with storage and retrieval machine and brake fin and method for monitoring a system

Abstract

System with storage and retrieval machine and brake fin, wherein the storage and retrieval machine can be moved along a route, wherein a permanent magnet arrangement is arranged on the storage and retrieval machine, wherein the brake fin is arranged to be movable on a first track section via a rotary joint arrangement, wherein the permanent magnet arrangement can cause a movement of the brake fin.

Description

[0001] The invention relates to a system with a storage and retrieval machine and a brake fin and a method for monitoring a system.

[0002] It is generally known that a storage and retrieval machine is designed to transport objects, whereby the objects can be transported along a travel path on the one hand and in a vertical direction on the other.

[0003] From DE 20 2013 011 458 U1, a gravity accumulating conveyor is known as the closest state of the art.

[0004] The invention is therefore based on the object of developing a device and a method, wherein the braking force of a movably arranged brake fin is more easily overcome when extending.

[0005] According to the invention, the object is achieved in the system according to the features specified in claim 1 or 2.

[0006] Important features of the invention in the system with storage and retrieval machine and brake fin according to claim 1 are that the storage and retrieval machine can be moved along a route, in particular a rail route, wherein a permanent magnet arrangement is arranged on the storage and retrieval machine, in particular wherein the brake fin is substantially flat and made of metal, wherein the brake fin is arranged to be movable on a first section of the route, in particular in a positively guided manner, in particular via a rotary joint arrangement, in particular via a parallel joint arm, that when the storage and retrieval machine enters the first section of the route, in particular at a minimum speed, the brake fin is inserted into a longitudinal slot of the permanent magnet arrangement extending in the direction of travel, to an increasing depth both in the direction of travel and perpendicular to the direction of travel, such that the magnetic flux flowing through the brake fin increases disproportionately to the distance travelled in the first section of the route, in particular, the minimum speed during retraction is so high that the force acting on the brake fin generated by eddy currents overcomes gravity.

[0007] The advantage here is that the brake fin is arranged so that it can move, so that when retracted, the braking force drives a positively guided movement of the brake fin. This movement is designed in such a way that the brake fin is raised during deceleration and thus plunges ever deeper into the longitudinal slot, namely parallel to the ground plane, i.e., in the horizontal direction, and parallel to the stroke axis, i.e., in the vertical direction. Due to the progressive increase in the area permeated by the magnetic flux associated with the plunge, the braking force increases accordingly and increasingly accelerates the brake fin as it moves.

[0008] The advantage of this movable brake fin arrangement is that during retraction, the brake fin is pulled along by the storage and retrieval machine up to a stop, and then retracted again during extension. During extension, the brake fin emerges from the longitudinal slot, particularly vertically, and the area permeated by the magnetic flux progressively decreases, as does the braking force generated during extension. Therefore, only a small torque is required from the traction motor during extension. This is because the braking force generated by the eddy-current brake decreases progressively during extension, thus even enabling accelerated exit from the first section of the track.

[0009] In contrast, a fixed brake fin would be difficult to overcome when extending.

[0010] The brake fin according to the invention is virtually self-switching, because when retracting the brake becomes increasingly stronger and when extending the brake is essentially switched off.

[0011] Important features of the system according to claim 2 are that the system is provided with a storage and retrieval machine and brake fin, wherein the storage and retrieval machine is movable along a route, in particular a rail route, wherein a permanent magnet arrangement is arranged on the storage and retrieval machine, wherein the brake fin is arranged to be movable on a first section of the route via a rotary joint arrangement, in particular via a parallel joint arm, wherein a movement of the brake fin, in particular a movement of the brake fin which is forcibly guided by the rotary joint arrangement, can be effected by the permanent magnet arrangement.

[0012] The advantage here is that, thanks to the swivel joint arrangement, the eddy current brake is switched on when retracting and essentially switched off after a very short time when extending.

[0013] Another advantage is that the brake fin is arranged so that it can move, so that when retracted, the braking force drives a positively guided movement of the brake fin. This movement is designed such that the brake fin is raised during deceleration and thus plunges ever deeper into the longitudinal slot, namely parallel to the ground plane, i.e., in the horizontal direction, and parallel to the stroke axis, i.e., in the vertical direction. Due to the progressive increase in the area permeated by the magnetic flux associated with the plunge, the braking force increases accordingly and increasingly accelerates the brake fin as it moves.

[0014] The advantage of this movable brake fin arrangement is that during retraction, the brake fin is pulled along by the storage and retrieval machine up to a stop, and then retracted again during extension. During extension, the brake fin emerges from the longitudinal slot, particularly vertically, and the area permeated by the magnetic flux progressively decreases, as does the braking force generated during extension. Therefore, only a small torque is required from the traction motor during extension. This is because the braking force generated by the eddy-current brake decreases progressively during extension, thus even enabling accelerated exit from the first section of the track.

[0015] In contrast, a fixed brake fin would be difficult to overcome when extending.

[0016] In an advantageous embodiment, the track is arranged on the floor of the system, in particular on a flat surface. This is advantageous because stable driving behavior can be achieved.

[0017] In an advantageous embodiment, the main magnetic flux in the longitudinal slot of the permanent magnet arrangement is aligned parallel to the normal direction of the plane accommodating the brake fin, which is preferably designed as a flat sheet. This is advantageous in that the strongest possible braking force can be generated.

[0018] In an advantageous embodiment, the main magnetic flux in the longitudinal slot of the permanent magnet arrangement is oriented perpendicular to the direction of travel and parallel to the floor plane of the system. This has the advantage of utilizing the magnetic field as efficiently as possible to generate braking force.

[0019] In an advantageous embodiment, during the movement of the brake fin, the center of gravity, in particular each point, of the brake fin is movable along a circular arc section. The advantage here is that as a result of the force acting on the brake fin generated by the eddy currents, the brake fin is moved along the circular arc section. When the storage and retrieval machine enters and exits the first travel section, the brake fin is carried along, in particular along the trajectory curve along which the brake fin is movable. When entering, however, the brake fin plunges deeper into the longitudinal slot, in particular transversely to the direction of travel of the storage and retrieval machine, so that the generated braking force increases progressively. When exiting the first travel section, the brake fin leaves the longitudinal slot very quickly, so that no significant counterforce slows the storage and retrieval machine down when it starts moving.

[0020] In an advantageous embodiment, the permanent magnet arrangement has a longitudinal slot through which the magnetic flux of the permanent magnet arrangement flows, wherein, when the storage and retrieval machine, in particular the permanent magnet arrangement, enters the first travel section, the brake fin penetrates into the longitudinal slot of the permanent magnet arrangement, in particular transversely to the direction of travel of the storage and retrieval machine, in particular increasingly deeper, so that in particular the distance to the ground or to a rail increases increasingly, In particular, when the storage and retrieval machine enters, a braking force directed and directed in such a way as to drive the movement of the brake fin is generated. The advantage here is that the eddy current brake is essentially activated when entering the first section of the track and deactivated when exiting.

[0021] In an advantageous embodiment, when the storage and retrieval machine, in particular the permanent magnet arrangement, exits the first travel section, the brake fin emerges from the longitudinal slot of the permanent magnet arrangement, in particular transversely to the direction of travel of the storage and retrieval machine, in particular increasingly, so that in particular the distance of the brake fin to the floor of the system or to a rail increasingly decreases. The advantage here is that the area of ​​the brake fin through which the magnetic flux flows is essentially the same as the area of ​​the brake fin immersed in the longitudinal slot. As a result of the circular movement, i.e. not just horizontal movement, but combined horizontal movement with vertical movement, the area through which the flow flows does not increase or decrease proportionally to the distance covered in the first travel section, but disproportionately, in particular according to an exponential relationship, in particular with an exponent greater than 1.

[0022] In an advantageous embodiment, it is important that when the storage and retrieval machine exits the first travel section, especially at the minimum speed, the brake fin emerges from the longitudinal slot in such a way that the magnetic flux flowing through the brake fin decreases disproportionately to the distance traveled in the first travel section. This is advantageous because the brake fin is pushed out of the longitudinal slot very quickly, allowing the storage and retrieval machine to accelerate very quickly.

[0023] In an advantageous embodiment, the system has a stationary A stop section that limits the movement of the brake fin. The advantage of this is that when the storage and retrieval machine enters the first section of the route, the brake fin is moved to the stop section and then limited, so that the brake fin can no longer deflect due to the braking force, thus applying the full braking force to the storage and retrieval machine.

[0024] In an advantageous embodiment, the brake fin is held by rotary levers that are aligned parallel to one another and, in particular, are identical to one another, In particular, each of the rotary levers is connected to a first rotary joint at its respective first end region and to a second rotary joint at its respective second end region. The advantage here is that the brake fin maintains its alignment during movement, i.e., it always remains parallel to the floor surface and / or to the rails laid on the floor.

[0025] In an advantageous embodiment, support buffers are arranged on the brake fin, particularly on the underside of the brake fin, to space the brake fin from the floor of the system. This is advantageous because a well-defined distance can be maintained. Furthermore, the support buffers can be made of an elastic material, such as plastic, for damping purposes.

[0026] In an advantageous embodiment, the brake fin is designed as a flat sheet metal part, in particular an aluminum sheet metal part. It is advantageous that the plane accommodating the flat sheet metal part extends in the direction of travel and perpendicular to it, in particular in the vertical direction.

[0027] In an advantageous design, rails are laid on the floor of the system, and the stacker crane is a rail vehicle. The advantage here is that the brake fin can be arranged parallel to the rail track, thus moving the stacker crane along the intended route.

[0028] Important features of the method for monitoring a system are that the line position of the storage and retrieval machine is recorded and a target speed is specified depending on the recorded line position, in particular by regulating the temporal progression of the recorded line positions to a temporal progression of specified target positions by specifying the temporal progression of the target speed, wherein the target speed decreases monotonically, in particular strictly monotonically, with the distance covered in the first route section after entering the first route section, wherein the traction drive of the storage and retrieval machine is operated in speed control, so that the detected speed of the storage and retrieval machine is regulated to the target speed by specifying a target torque or a target motor current as a control variable to the traction drive, in particular the electric motor of the traction drive, wherein the value of the manipulated variable is monitored for an amount exceeding a threshold value, in particular so that a warning is displayed and / or reported depending on whether the threshold value is exceeded.

[0029] The advantage here is that the drive is operated in closed-loop control mode, and the manipulated variable value determined by the drive controller indicates whether the eddy-current brake is functioning as intended or whether a defect exists. This allows the brake test to be performed without any special effort.

[0030] In an advantageous embodiment, the target speed decreases in the first section of the route proportionally to the distance traveled in the first section. The advantage here is that monitoring can be carried out in a simple manner.

[0031] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0032] The invention will now be explained in more detail using schematic illustrations: In the Fig. 1 shows a schematic diagram of a system according to the invention with a storage and retrieval machine and brake fin 1. In the Fig. 2 to 5 schematically show the entry of the storage and retrieval machine into the area of ​​the brake fin 1. In the Fig. 2 shows a schematic representation of the state of the system before the effective connection between the storage and retrieval machine and the brake fin 1 is established. In the Fig. 3 shows a schematic representation of the state of the system when the active connection between the storage and retrieval machine and the brake fin 1 occurs. In the Fig. 4 schematically shows the folding up of the brake fin 1 when the storage and retrieval machine is moving in. In the Fig. Figure 5 shows a schematic representation of the state of the system when the storage and retrieval machine has moved into the brake fin 1 and has come to rest. In the Fig. 6 to 8, the extension of the storage and retrieval machine into the area of ​​the brake fin 1 is schematically sketched. In the Fig. Figure 6 shows a schematic representation of the system’s status before the stacker crane is extended. In the Fig. Figure 7 shows a schematic illustration of the folding down of the brake fin 1 when the stacker crane is extended. In the Fig. Figure 8 shows a schematic representation of the state of the system after the stacker crane has been extended.

[0033] As shown in the figures, the system comprises a storage and retrieval machine with a traction drive 3 that drives at least one wheel of the storage and retrieval machine. A further drive is a lifting drive, which enables a load picked up by the storage and retrieval machine to be moved vertically and thus loaded and unloaded at different heights.

[0034] Preferably, the storage and retrieval machine is designed as a rail vehicle and can be moved along the rail line 2.

[0035] On the underside of the storage and retrieval machine, in particular on the underside of the frame of the storage and retrieval machine, a permanent magnet arrangement 4 is arranged as the active part. The permanent magnet arrangement generates a magnetic field that traverses the longitudinal slot, thus in particular being oriented in the longitudinal slot substantially perpendicular to the direction of extension of the longitudinal slot.

[0036] In one section of the track, a brake fin is arranged as a sword-shaped reactive part, so that it protrudes into the longitudinal slot when the storage and retrieval machine approaches the brake fin 1. As long as the storage and retrieval machine is moving, eddy currents are induced in the brake fin 1 by the permanent magnet arrangement. In this way, the braking effect is achieved according to the principle of the eddy current brake.

[0037] The brake fin 1 is movable via rotary levers 20, with the rotary levers 20 being attached at their first end portion to the floor of the system via a rotary joint, to which the rails of the track 2 are also placed and secured. At the other end portion of the rotary lever 20, another rotary joint is provided, which is attached to the brake fin 1. The brake fin 1 can thus be pivoted while maintaining a parallel alignment.

[0038] In particular, the rotary levers 20 form a parallel articulated arm for the brake fin 1. Thus, during the rotary movement of the rotary lever 20, the brake fin 1 remains parallel to the rails, but is raised during the rotary movement in the vertical direction, i.e., in the conveying direction of the lifting gear of the storage and retrieval machine, and is also displaced in the direction of the rails. Each point of the brake fin 1 moves along a circular path.

[0039] If now, as in Fig. 3, the storage and retrieval machine with its permanent magnet arrangement moves towards the brake fin 1 and the brake fin 1 projects further and further into the longitudinal slot of the permanent magnet arrangement 4, the brake fin is lifted as a result of the resulting braking force, in particular resulting force 30, during pivoting and simultaneously displaced in the rail direction until a stationary stop part 21 stops the brake fin 1 and this thus rests against the stop part 21, as in Fig. 3. The stop part 21 is attached directly or indirectly to the floor of the system.

[0040] Support buffers 22 are preferably arranged on the underside of the brake fin 1, by means of which the brake fin 1 remains spaced from the ground, in particular when it is lowered.

[0041] As in the Fig. 6 to 8, when the permanent magnet arrangement 4 is pulled out, a resulting force 70 is generated which causes the brake fin to lower; after leaving the permanent magnet arrangement 4, the brake fin 1 rests on the ground via the support buffers 22.

[0042] It is also important that when the brake fin 1 emerges from the longitudinal slot of the permanent magnet arrangement 4, the magnetic flux flowing through the brake fin 1 decreases disproportionately to the distance covered in the first section of the route, since the brake fin 1 not only emerges parallel to the direction of travel, but is also pushed out in the transverse direction, in particular towards the ground.

[0043] As in Fig. 9, a brake test can be carried out.

[0044] In Fig. 9 shows the time course 90 of the speed and the time course of the torque 91 when the permanent magnet arrangement 4 is retracted into the brake fin 1, in particular in the case of the Fig. 2 to 5 step-by-step schematic representation of the process.

[0045] Before retraction, the traction drive generates a torque M, which is supplied to the drive wheel, and the storage and retrieval machine has a speed v in the rail direction. After the permanent magnet arrangement 4 has entered the area of ​​the brake fin 1, a braking torque is generated by the eddy current brake formed by the permanent magnet arrangement 4 in operative connection with the brake fin 1, so that the traction drive does not have to generate any torque to reduce the speed of the storage and retrieval machine in the intended manner, in particular according to Fig. 9 proportional to the time.

[0046] The eddy current brake is therefore considered to be functioning properly when the torque required by the traction drive during deceleration disappears or remains below a threshold value 92. To monitor the torque, this is recorded, in particular by forming a model value for the torque of the traction drive in a control unit of an inverter or converter feeding the traction drive and monitoring it, in particular as an actual value 93, for the amount of the threshold value 92 being exceeded. The course of the actual value 93 is shown in Fig. 9 shown.

[0047] In Fig. 9 shows the mathematically determined curve 94 of the torque, in particular the target torque, during the braking process.

[0048] In further embodiments of the invention, instead of the torque, the motor current is monitored for whether its magnitude exceeds a threshold value 92 for motor current. Since the motor current can be measured inexpensively using a commercially available sensor, this monitoring is simple and cost-effective to implement. List of reference symbols 1 brake fin, in particular sword-shaped reactive part 2 rail lines 3 Traction drive 4 permanent magnet arrangement 5 Lifting drive 6 Brake fin, in particular sword-shaped reactive part 20 rotary levers 21 Stop part 22 support buffers 30 resulting force 70 resulting force 90 temporal course of speed 91 Time course of torque 92 Threshold 93 Course of the actual torque 94 Course of the target torque

Claims

[1] System with storage and retrieval machine and brake fin (1), wherein the storage and retrieval machine can be moved along a route, wherein a permanent magnet arrangement (4) is arranged on the storage and retrieval machine, characterized by , that the brake fin (1) is arranged on a first section of the route so as to be movable via a parallel articulated arm, that when the storage and retrieval machine enters the first travel section, the brake fin (1) dips increasingly deeper into a longitudinal slot of the permanent magnet arrangement (4) extending in the direction of travel, both in the direction of travel and perpendicular to the direction of travel, such that the magnetic flux flowing through the brake fin (1) increases disproportionately to the distance covered in the first travel section. [2] System with storage and retrieval machine and brake fin (1), wherein the storage and retrieval machine can be moved along a route, wherein a permanent magnet arrangement (4) is arranged on the storage and retrieval machine, characterized by , that the brake fin (1) is arranged to be movable on a first section of the route via a rotary joint arrangement, wherein the permanent magnet arrangement (4) can cause a movement of the brake fin (1). [3] Plant according to claim 1 or 2, characterized by that the track is located on the floor of the system. [4] Plant according to one of the preceding claims, characterized by , that the main magnetic flux in the longitudinal slot of the permanent magnet arrangement (4) is aligned parallel to the normal direction of the plane receiving the brake fin (1) and / or that the main magnetic flux in the longitudinal slot of the permanent magnet arrangement (4) is aligned perpendicular to the direction of travel and parallel to the floor plane of the system. [5] Plant according to one of the preceding claims, characterized bythat when the brake fin (1) moves, the center of gravity of the brake fin (1) can be moved along a circular arc section. [6] Plant according to one of the preceding claims, characterized by , that the permanent magnet arrangement (4) has a longitudinal slot through which the magnetic flux of the permanent magnet arrangement (4) flows, wherein when the storage and retrieval machine enters the first travel section, the brake fin (1) penetrates into the longitudinal slot of the permanent magnet arrangement (4). [7] Plant according to one of the preceding claims, characterized by , that when the storage and retrieval machine leaves the first section of the route, the brake fin (1) emerges from the longitudinal slot of the permanent magnet arrangement (4), and / or that that when the storage and retrieval machine moves out of the first travel section, the brake fin (1) emerges from the longitudinal slot increasingly both in the direction of travel and perpendicular to the direction of travel, such that the magnetic flux flowing through the brake fin (1) decreases disproportionately to the distance traveled in the first travel section. [8] Plant according to one of the preceding claims, characterized by that the system has a stationary stop part (21) which limits the movement of the brake fin (1). [9] Plant according to one of the preceding claims, characterized by , that the brake fin (1) is held by rotary levers (20) aligned parallel to each other, wherein each of the rotary levers (20) is connected at its respective first end region to a respective first rotary joint and is connected at its respective second end region to a respective second rotary joint. [10] Plant according to one of the preceding claims, characterized by that support buffers (22) are arranged on the brake fin (1) to space the brake fin (1) from the floor of the system. [11] Plant according to one of the preceding claims, characterized by that the brake fin (1) is designed as a flat sheet metal part, in particular an aluminum sheet metal part. [12] Plant according to one of the preceding claims, characterized by that there are rails on the floor of the system and that the stacker crane is a rail vehicle. [13] Method for monitoring a system according to one of the preceding claims, characterized by , that the line position of the storage and retrieval machine is recorded and a target speed is specified depending on the recorded line position, where the target speed decreases monotonically with the distance covered in the first section of the route after entering this first section of the route, wherein the traction drive (3) of the storage and retrieval machine is operated in speed control, so that the detected speed of the storage and retrieval machine is regulated to the target speed by specifying a target torque or a target motor current to the traction drive (3) as a control variable, wherein the value of the manipulated variable is monitored for exceeding a threshold value (92). [14] Method according to one of the preceding claims, characterized by that in the first section of the route the target speed decreases proportionally to the distance covered in the first section of the route.

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