JP2018039584A - Stacker crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stacker crane capable of easily obtaining a vibration control effect.SOLUTION: A stacker crane includes: a travel base that travels along a travel base; a plurality of masts that rise perpendicularly from the travel base; a connection part for connecting the tips of the masts; and transfer units that are horizontally supported in an ascendable/descendable manner among the plurality of masts. A weight mounted on the connection part in such a manner as to be movable along the traveling direction of the travel base, and an operation part for putting the weight into linear motion in the opposite direction of the acceleration direction or deceleration direction of the travel base are provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to vibration control of a stacker crane.

  The dimensions of the stacker crane differ depending on the size of the storage rack to be transferred, but when used for a relatively large storage rack, the ratio of the height to the width of the stacker crane is large, and at high speed. A moving stacker crane is used. This type of stacker crane is liable to generate vibrations when stopped.

  Conventionally, measures such as providing a stopper with an absorber at a stop position in the traveling direction have been taken. In addition, a damper that uses an electrorheological fluid is provided on a guide roller that is in rolling contact with a guide rail provided on the ceiling, and a method of controlling vibration of the guide roller is adopted (Patent Document 1, etc.). In addition, the natural frequency (frequency) of the stacker crane is obtained, the speed pattern that amplifies the vibration and the speed pattern that does not become the acceleration are specified from the natural frequency, and the vibration is controlled to control the traveling by the speed pattern. Methods have been adopted (Patent Documents 2 to 4).

JP-A-9-208090 JP 2007-269450 A JP 2009-023769 A JP 2010-030728 A

  However, a stopper with an absorber is required for each stop position, and a damper using an electrorheological fluid is required to have high controllability of viscosity and accuracy of installation of the damper. Furthermore, even in the control using the speed pattern according to the natural frequency, it may be complicated such that it is necessary to specify the speed pattern every time the condition changes.

  This invention is made | formed in view of such a situation, and it aims at providing the stacker crane which can acquire the damping effect easily.

  A stacker crane according to the present disclosure includes a traveling platform that travels along a traveling rail, a plurality of masts that stand upright from the traveling platform, a connecting portion that connects tips of the masts, and a horizontal mount that can be raised and lowered between the plurality of masts. In a stacker crane including a supported transfer unit, a weight attached to the connecting portion so as to be movable along the traveling direction of the platform, and the weight in a direction opposite to the acceleration direction or the deceleration direction of the platform. And an actuating part that linearly moves the weight.

  In the stacker crane according to the present disclosure, the actuating unit starts the movement of the weight in the direction opposite to the deceleration direction of the traveling platform, together with the start of braking of the traveling platform.

  In the stacker crane according to the present disclosure, the operating unit starts the movement of the weight in the direction opposite to the traveling direction of the traveling table as the traveling table starts.

  In the stacker crane according to the present disclosure, the operation unit decelerates and stops the weight more slowly than the acceleration at the start of the movement of the weight.

  In the present disclosure, a reaction force that counteracts inertia is generated by the movement of the weight attached to the connecting portion that connects the ends of the plurality of masts constituting the stacker crane in the direction opposite to the acceleration direction or the deceleration direction. Vibration is suppressed.

  In the present disclosure, the operation unit moves the weight in the same direction as the traveling direction, that is, in the direction opposite to the deceleration direction, together with the start of braking of the stacker crane. As a result, the reaction force acts to cancel the inertial force in the traveling direction that is generated when the stacker crane is braked. For this purpose, it is only necessary to branch a signal for instructing the start of braking into an operation signal to the operation unit, and vibration can be realized by a simple method.

  In the present disclosure, the operation unit moves the weight in the direction opposite to the traveling direction, that is, in the direction opposite to the acceleration direction even when the stacker crane starts to travel. Thereby, the reaction force acts so as to cancel the inertial force in the direction opposite to the traveling direction generated when the stacker crane starts traveling. For this purpose, it is only necessary to divide a signal instructing the start of traveling into an operation signal to the operation unit, and vibration suppression can be realized by a simple method.

  In the present disclosure, when the weight returns to a stationary state after starting the motion, the weight is decelerated more slowly than the acceleration at the start of the motion. Thereby, the vibration by the operation of the weight when returning to the stationary state is prevented.

  In the case of the stacker crane according to the present disclosure, vibration can be controlled by a simple method in which a weight attached so as to be able to move in the traveling direction is moved in the traveling direction.

It is a model perspective view of the stacker crane in this Embodiment. It is a front view of a stacker crane. It is a side view of a stacker crane. It is a model expansion perspective view of the attachment part of a damping part. It is a block diagram which shows the structure of a control mechanism. It is a graph which shows an example of the speed change of a weight. It is explanatory drawing which shows typically about the vibration at the time of the travel start of a traveling stand. It is explanatory drawing typically shown about the vibration at the time of braking of a traveling stand.

  The present invention will be specifically described with reference to the drawings showing the embodiments thereof.

  FIG. 1 is a schematic perspective view of a stacker crane 1 in the present embodiment. FIG. 2 is a front view of the stacker crane 1, and FIG. 3 is a side view of the stacker crane 1.

  In the following description, the top and bottom, left and right, and front and rear indicated by arrows in FIG. 1 are used. The stacker crane 1 in the present embodiment is a floor-type stacker crane that travels on a traveling rail 11 laid on the floor of a facility.

  The stacker crane 1 includes a traveling platform 12 that is supported on a traveling rail 11 via drive wheels and travels along the traveling rail 11. The traveling platform 12 has an elongated shape along the traveling rail 11 and has the drive wheels at the lower portions of both ends thereof. Further, the traveling platform 12 includes a guide frame 13 including a plurality of (for example, two) rectangular tube-shaped masts 31 standing upright at the upper portions of both ends thereof, and a rectangular tube-shaped connecting portion 32 for connecting the masts 31 at the upper portion. Is fixed. The transfer unit 14 is supported horizontally between the masts 31 of the guide frame 13. The transfer unit 14 includes guide wheels that rotate in the vertical direction, and is in rolling contact with each of the masts 31 by the guide wheels. The transfer unit 14 is connected to one end of an elevating belt (chain) 15. The lifting belt 15 extends upward from the transfer unit 14, is folded back at the top of the guide frame 13 and extends downward, and the other end is again transferred via the feed mechanism 151 provided on the traveling platform 12. It is connected to. The transfer unit 14 moves up and down along the mast 31 when the lifting belt 15 is fed by the feeding mechanism 151.

  The stacker crane 1 further includes a frame 16. The frame 16 is fixed at a predetermined distance from the traveling rail 11 on the floor on the rear side and fixed to a corresponding position on the rear side of the front column and a plurality of front columns fixed side by side in the left-right direction. It is composed of a plurality of rear struts and beams connecting the struts. The beam connects the upper part of the front strut in the left-right direction, the back struts in the left-right direction, and a plurality of vertical beams between the front strut and the rear strut corresponding to the front and rear. And longitudinal beams connected across the steps.

  The vertical beam at the top of the frame 16 extends forward for an appropriate length. A traveling guide 17 is installed in the left-right direction so as to correspond to the entire length of the traveling rail 11 at the extended portion of the uppermost vertical beam. A guide wheel provided behind the connecting portion 32 at the upper part of the guide frame 13 rolls into contact with the travel guide 17. As a result, the upper portion of the guide frame 13 is supported by the travel guide 17.

  A power distribution unit 18 is installed in the left-right direction along the traveling guide 17 on the rear side of the traveling guide 17 on the extended portion of the uppermost vertical beam of the frame 16. The length of the power distribution unit 18 also extends over the entire length of the traveling rail 11. The power distribution unit 18 accommodates a cable for supplying power and signals to the mounted devices such as the above-described feed mechanism 151 installed on the traveling platform 12. The guide frame 13 is provided with cables for supplying power and signals to each mounted device on the traveling platform 12. The cable disposed in the guide frame 13 can be connected to the power distribution section regardless of the position of the traveling platform 12 on the traveling rail 11 by the connecting portion provided at a position behind the guide wheel from the connecting portion 32. 18 in electrical contact.

  The stacker crane 1 in the present embodiment further includes a vibration control unit 2. The vibration damping unit 2 is attached to the connecting portion 32 at the top of the guide frame 13. FIG. 4 is a schematic enlarged perspective view of a mounting portion of the vibration damping unit 2. The vibration control unit 2 includes a weight 21 and a cylinder 22. The cylinder 22 is an electric cylinder, and is fixed so that the longitudinal direction thereof follows the connecting portion 32, that is, along the traveling direction. The cylinder 22 has an output end protruding upward, and a weight 21 is attached to the output end. The weight 21 can move in the traveling direction by the stroke length of the cylinder 22.

  The stacker crane 1 includes a control unit 10 on a traveling platform 12. FIG. 5 is a block diagram illustrating a configuration of the control unit 10 of the stacker crane 1. The control unit 10 controls and outputs a signal based on a predetermined control logic using a storage unit such as a PLC (Programmable Logic Controller) and a flash memory. For example, the control unit 10 outputs a signal for controlling traveling and raising / lowering to each of a traveling motor that rotates a driving wheel of the traveling platform 12 and a lifting motor included in a feed mechanism 151 that sends the lifting belt 15. The control unit 10 performs control while specifying the travel position and height based on the output pulses from the rotary encoders attached to the output shafts of the travel motor and the lifting motor. Further, the control unit 10 can control acceleration / deceleration in a plurality of stages when controlling running and raising / lowering. The control unit 10 also outputs a control signal that instructs the vibration control unit 2 to operate.

  The traveling control of the stacker crane 1 in the present embodiment will be described. In the stacker crane 1, the control unit 10 sets a predetermined position (for example, the left end or the right end) on the traveling rail 11 as the initial position of the traveling platform 12, and controls the traveling of the traveling platform 12 based on the initial position. Basically, when starting the travel from the initial position, the control unit 10 travels at a low speed up to a predetermined travel distance (output pulse), travels at a medium speed after reaching the travel distance, and exceeds a predetermined distant travel distance. When it becomes, it will switch the traveling stand 12 to high-speed driving | running | working. When stopping at any one of a plurality of travel stop positions stored in advance in the storage unit, the control unit 10 decelerates the vehicle so that the vehicle travels at a medium speed when a predetermined distance is exceeded before the travel stop position. Further, after the vehicle is decelerated so that the vehicle travels at a low speed when it reaches a predetermined position immediately before the travel stop position, a braking signal for instructing braking is output to the travel motor before the travel stop position.

  The operation of the vibration control unit 2 during the travel control of the stacker crane 1 will be described. When the traveling platform 12 starts traveling from the initial position, the control unit 10 controls the vibration control unit 2 in advance, and places the weight 21 at the end near the traveling direction. That is, when the initial position is the left end of the traveling rail 11, the control unit 10 keeps the weight 21 at the right end on the cylinder 22 every time the traveling platform 12 returns to the initial position. When the traveling platform 12 is present at a stop position other than the initial position, the control unit 10 identifies whether the traveling direction to the next traveling stop position is left or right, and ends the direction closer to the traveling direction before starting traveling. The weight 21 may be moved to the part.

  When the control unit 10 outputs the travel start signal to the travel motor, the travel start signal is branched and output to the vibration control unit 2. Immediately after receiving the travel start signal, the vibration control unit 2 receives this as an ON signal and operates the cylinder 22. The cylinder 22 moves the weight 21 located at one end to the other end. The initial acceleration when moving at this time is, for example, the maximum design acceleration of the cylinder 22. The cylinder 22 thereafter moves the weight 21 at a constant speed (when reaching a predetermined speed), and decelerates the weight 21 before reaching the other end. The acceleration at this time is set to, for example, -0.5 G, and the speed is gradually reduced. This is because an extra force is applied to the guide frame 1 due to the acceleration when the weight 21 is stopped, and vibration as described later is not generated. FIG. 6 is a graph showing an example of the speed change of the weight 21. Simultaneously with the start of traveling of the traveling platform 12, the weight 21 is accelerated at the maximum acceleration, and thereafter moves at a constant speed, and is decelerated so as to stop gently at the other end.

  When the control unit 10 outputs a braking signal, the braking signal is branched and output to the vibration control unit 2. Immediately after receiving the braking signal, the damping unit 2 receives this as an ON signal and operates the cylinder 22. The cylinder 22 moves the weight 21 located at one end to the other end. At this time, the weight 21 is moved from the end near the traveling direction to the direction opposite to the traveling direction and is located at the opposite end at the start of traveling. In other words, when the traveling direction is rightward, the weight 21 that is at the right end on the cylinder 22 at the initial position of the traveling platform 12 is positioned at the left end of the cylinder 22 during traveling. Even during braking, the initial acceleration when moving the weight 21 is, for example, the maximum design acceleration of the cylinder 22. Thereafter, the cylinder 22 moves the weight 21 at a constant speed (when it reaches a predetermined speed), and decelerates the weight 21 before reaching the other end (FIG. 6). Simultaneously with the start of braking of the carriage 12, the weight 21 is accelerated at the maximum acceleration, and thereafter moves at a constant speed, and is decelerated so as to stop gently at the other end.

  The effect by operation | movement of the damping part 2 is demonstrated. FIG. 7 is an explanatory diagram schematically showing vibration at the start of traveling of the traveling platform 12. FIGS. 7A to 7C sequentially show the force applied to the stacker crane 1, particularly the guide frame 13 in order from FIG.

  FIG. 7A schematically shows the state of the guide frame 13 at the stop before the start of traveling, and FIG. 7B schematically shows the state of the guide frame 13 at the start of traveling. The broken line indicates the state of the guide frame 13 when the vibration damping unit 2 in the present embodiment is not operated. When the vehicle starts running from the stop state, inertia force F1 is applied to the guide frame 13 as shown in FIG. However, at this time, the cylinder 22 is actuated to give a large acceleration in the direction opposite to the traveling direction (acceleration direction) of the weight 21, and the connecting portion 32 of the guide frame 13 to which the cylinder 22 of the vibration damping portion 2 is fixed. Is applied with a reaction force F2 in the traveling direction. Thereby, inertial force F1 and reaction force F2 cancel each other, and bending is suppressed as shown by the solid line in FIG. 7B. Since the bending is suppressed, when the damping unit 2 is not operated, the reaction as shown by the broken line is also suppressed and the vibration is settled earlier and converges as shown in FIG.

  Next, the effect at the time of braking of the damping unit 2 will be described. FIG. 8 is an explanatory diagram schematically showing vibration during braking of the traveling platform 12. FIGS. 8A to 8F sequentially show the force applied to the stacker crane 1, particularly the guide frame 13 in order from FIG.

  FIG. 8A schematically shows the state of the guide frame 13 when traveling in the right direction in the figure at high speed. At this time, the traveling platform 12 and the guide frame 13 are integrally traveling at a constant speed.

  FIG. 8B schematically shows the state of the guide frame 13 when the vehicle is decelerated from high speed traveling to medium speed traveling or low speed traveling. When the vehicle is decelerated as shown in FIG. 7B, the upper portion of the guide frame 13 is bent more greatly in the traveling direction due to the inertial force.

  FIG.8 (c) has shown the reaction which returns the bending of the guide frame 13 at the time of deceleration. Due to the deceleration of the carriage 12, vibrations as shown in FIGS. 8B and 8C are generated.

  FIG. 8D schematically shows the state of the guide frame 13 at the start of braking of the carriage 12. Also in FIG. 8, the broken line shows the state of the guide frame 13 when the vibration damping unit 2 in the present embodiment is not operated. There is a possibility that the inertial force F3 of the guide frame 13 is maximized due to the start of braking for stopping from low speed running. As a result, as shown by the broken line, the guide frame 13 generates the maximum deflection. However, in the stacker crane 1 according to the present embodiment, the damping unit 2 operates as shown in FIG. 6 at the start of braking, and the cylinder 21 is actuated to move the weight 21 in the direction of travel (opposite to the deceleration direction). Is given a big acceleration. By this acceleration, a reaction force F4 in the direction opposite to the traveling direction is applied to the connecting portion 32 of the guide frame 13 to which the cylinder 22 of the vibration damping portion 2 is fixed. Thereby, inertial force F3 and reaction force F4 cancel each other, and bending is suppressed as shown by the solid line in FIG.

  FIG. 8E shows a reaction that returns the deflection of the guide frame 13 after the start of braking. The broken line indicates the state of the guide frame 13 when the vibration damping unit 2 in the present embodiment is not operated. When the maximum bending occurs due to braking, the reaction of the bending increases as shown by the broken line, and it takes time until the vibration due to the bending and the swinging back is settled even after the traveling platform 12 stops. However, in the stacker crane 1 according to the present embodiment, the vibration control unit 2 suppresses the bending as shown in FIG. 8D, so that the reaction is also suppressed as shown in FIG. The vibration is settled and converges to a stationary state in a short time as shown in FIG.

  After that, when returning from the travel stop state (FIG. 8 (f)) to another position, for example, the initial position, the control unit 10 moves the weight 21 closer to the initial position on the cylinder 22 in the same manner. Move it to the end. Even at the start of advancement to the initial position, the control unit 10 moves the damping unit 2 by maximum acceleration in the direction opposite to the direction of travel, and gently stops at the end opposite to the direction of travel. Similarly, when stopping at the initial position, the control unit 10 moves the damping unit 2 toward the traveling direction by maximum acceleration at the start of braking, and gently stops it. Thereby, also when returning to an initial position, generation | occurrence | production of the vibration by the bending and reaction of the guide frame 13 is suppressed.

  The inventors have a case where the transfer unit 14 is positioned above the guide frame 13 and a position below the guide frame 13 under the condition that the traveling platform 12 and the guide frame 13 are about 1 t in total and the transfer unit 14 is 250 kg. In some cases, an experiment was performed in which the vibration control unit 2 was operated. At this time, the stroke length of the cylinder 22 was 50 cm, for example, and the weight 21 was 6 kg. Further, in this experiment, for the purpose of comparison, traveling stop was performed when the vibration control unit 2 was not operated and when the vibration control unit 2 was operated for a predetermined time before or after a predetermined time. As a result, in both the case where the transfer unit 14 is located at the upper part and the case where the transfer unit 14 is located at the lower part, the vibration of the guide frame 13 after the start of braking most occurs when the damping unit 2 is operated at the start of braking. Was small. When the vibration control unit 2 is operated before and after the braking start time, the amplitude may be greater than when the vibration control unit 2 is not operated depending on the case where the transfer unit 14 is positioned at the upper part and the lower part. There was a time when became bigger. That is, the effect of the operation of the damping unit 2 is increased by operating the damping unit 2 simultaneously with the start of braking. Therefore, since a higher effect can be obtained with a simple configuration in which a braking signal to the traveling platform 12 is branched and given to the vibration control unit 2 as an ON signal, the practicality is high.

  The weight of the weight 21, the stroke length of the cylinder 22, the acceleration of the weight 21 at the start of the operation, and the acceleration for decelerating the weight 21 are preferably designed as appropriate. Furthermore, by setting the vibration control unit 2 to be capable of switching to a plurality of stages of acceleration, the same vibration control unit 2 is used for stacker cranes of different dimensions, and settings are made for each different stacker crane. There is a possibility that the steps to be performed can be omitted.

  In this Embodiment, it was set as the structure which operates the damping part 2 both at the time of the driving | running | working start of the platform 12 and at the time of braking. However, the damping unit 2 may be operated only when the traveling platform 12 is braked. At the start of traveling, the vibration tends to settle early due to the inertial force thereafter, but at the time of stopping, it tends to take time for the vibration to converge, and damping at the stop position is important in the stacker crane. When the vibration control unit 2 is operated only during braking, the control unit 10 places the weight 21 on the end opposite to the next traveling direction on the cylinder 22 before starting traveling. That is, when the initial position is the left end on the traveling rail 11, the control unit 10 keeps the weight 21 at the left end on the cylinder 22 every time the traveling platform 12 returns to the initial position. When the traveling platform 12 is present at a stop position other than the initial position, the control unit 10 identifies whether the traveling direction to the next traveling stop position is left or right and starts traveling or starts traveling. It is advisable to move the weight 21 to the end on the opposite side before starting.

  In the present embodiment, the floor type stacker crane has been described as an example, but the present invention can also be applied to other types of stacker cranes. For example, a suspension type or an overhead crane type may be used. In this case, the vibration control unit 2 is attached to the lower part.

  In the stacker crane 1 shown in FIG. 1, the plurality of front support columns are not connected in the left-right direction, and the support posts of these frames 13 are one of the frames of the shelf on which the load to be transferred is placed. It may be used as a part.

  It should be understood that the embodiment disclosed above is illustrative in all respects and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Stacker crane 11 Traveling rail 12 Traveling stand 13 Guide frame 31 Mast 32 Connection part 14 Transfer unit 10 Control part 2 Damping part 21 Weight 22 Cylinder (operation part)

Claims (4)

A traveling platform that travels along the traveling rail, a plurality of masts that stand upright from the traveling platform, a connecting portion that connects tips of the masts, and a transfer unit that is horizontally supported so as to be movable up and down between the plurality of masts. In stacker cranes,
A weight attached to the connecting portion so as to be movable along the traveling direction of the platform;
A stacker crane, comprising: an operating unit that linearly moves the weight in a direction opposite to an acceleration direction or a deceleration direction of the platform. 2. The stacker crane according to claim 1, wherein the actuating unit starts a movement of the weight opposite to a deceleration direction of the traveling platform along with the braking of the traveling platform. 3. The stacker crane according to claim 1, wherein the operation unit starts a movement of the weight opposite to a traveling direction of the traveling table as the traveling table starts. 3. The stacker crane according to any one of claims 1 to 3, wherein the operating unit decelerates and stops the weight more slowly than an acceleration at the start of the movement of the weight.

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