JP5426905B2 - Work pickup system - Google Patents

Description

  The present invention relates to a workpiece pick-up system that lifts a plurality of gripping means by attracting them to a workpiece.

  In a workpiece pickup system, a technique is known in which a vacuum cup as a gripping means is lifted and lowered by a servo mechanism, and the vacuum cup lifting speed is switched from a high speed to a low speed before the vacuum cup reaches the work (for example, a patent) Reference 1).

  According to Patent Document 1, since the size of the workpiece is not taken into consideration, the number of vacuum cups is not a problem, and the workpiece is picked up by a single vacuum cup.

JP-A-4-274732

  However, when the size of the workpiece is large, it is necessary to provide a plurality of vacuum cups, and in order to prevent double blanking (two pieces of workpieces), the plurality of vacuum cups may be raised at different timings. .

  In this case, after waiting for completion of transfer by the transfer means, if a plurality of vacuum cups are lowered at the same time and adsorbed to the workpiece at the same time, the vacuum cup that rises last is raised after waiting for the vacuum cup to rise first Therefore, a wasteful waiting time is generated in the last rising vacuum cup, and the cycle time is long.

  An object of this invention is to provide the workpiece pick-up system which can shorten the cycle time of a workpiece conveyance, preventing a double blank.

(1) A work pick-up system for picking up and lifting a plurality of gripping means on a work, a transport means for transporting the work in a transport direction, a plurality of gripping means provided in the transport direction, and a work by the transport means A lowering means for sequentially lowering the workpiece from the standby position toward the workpiece from the gripping means positioned at the extreme end opposite to the conveying direction, and a gripping that lowers at least first and next by the lowering means The first lifting means that raises at least the first lowering gripping means by a predetermined distance and the last lowering gripping means before the gripping means that descends last after the means sucks on the work attracts the work. A second raising means for raising all of the plurality of gripping means toward the standby position immediately after being attracted to
Work pickup system with

  According to the configuration of (1), the workpiece pick-up system has at least the first lowering grip before the first lowering gripping means attracts the work and the last lowering gripping means attracts the work. The means is raised by a predetermined distance, and immediately after the last descending gripping means is attracted to the workpiece, all of the plurality of gripping means are raised toward the standby position.

  Therefore, the useless waiting time from when the gripping means that descends last is attracted to the workpiece and then rises is eliminated, so that the cycle time can be shortened.

  The lowering means sequentially lowers the gripping means while the workpiece is being conveyed. That is, since the gripping means is lowered without waiting for the completion of the conveyance of the workpiece, a useless waiting time until the conveyance is completed is eliminated, and the cycle time can also be shortened from this.

  Further, the first raising means raises at least the first descending gripping means by a predetermined distance before the first last descending gripping means is attracted to the work and the last descending gripping means is attracted to the work. .

  Therefore, since it can release from the edge part of workpiece | work, a double blank can be prevented, without providing the magnet floater for opening a clearance gap between workpiece | works.

  (2) The workpiece pickup system according to (1), further including a blowing unit that sends air into a gap between the workpieces, wherein the blowing unit includes at least the first lowering unit by the first raising unit. A work pickup system that feeds air on the condition that it has risen.

  According to the configuration of (2), the air blowing means sends air into the gap between the workpieces on the condition that at least the gripping means that first descends is raised by the first raising means, thereby further strengthening the prevention of double blanks. be able to.

  ADVANTAGE OF THE INVENTION According to this invention, the workpiece pick-up system which can shorten the cycle time of a workpiece conveyance, preventing a double blank can be provided.

1 is a side view of a work pickup system 1 according to an embodiment of the present invention. 1 is a plan view of a work pickup system 1 according to an embodiment of the present invention. It is a block diagram which shows the relationship between the control apparatus with which the workpiece pick-up system 1 which concerns on one Embodiment of this invention is provided, and the relationship between servo cylinders 11A-11E. It is a flowchart which shows the flow of control in which a control apparatus lowers servo cylinders 11A-11E. It is a flowchart which shows a mode that servo cylinder 11A-11E starts a fall from a standby position. It is a figure which shows a mode that the servo cylinder 11A raises predetermined distance and air is sent into the clearance gap between blanks 15. FIG. It is a figure which shows a mode that all the vacuum cups 13A-13E are adsorb | sucking to the blank 15. FIG. It is a figure which shows a mode that the servo cylinders 11A-11E are raising. It is a figure which shows a mode that the blank 15 is conveyed after servo cylinder 11A-11E returns to a standby position.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view of a work pickup system 1 according to an embodiment of the present invention.

  The work pickup system 1 includes servo cylinders 11A to 11E, support shafts 12A to 12E, vacuum cups 13A to 13E, an MGT (magnet) belt 14, a control device (not shown), a plurality of blanks 15, A support base 16 that supports the blank 15, a blower that feeds air into the gap between the blanks, and a fan (not shown) are provided.

  The support shafts 12A to 12E are members that support the vacuum cups 13A to 13E. Further, the support shafts 12A to 12E are connected to the servo cylinders 11A to 11E. A plurality of blanks 15 and a support base 16 that supports the blanks 15 are disposed below the vacuum cups 13A to 13E. Further, FIG. 1 shows a state where the servo cylinders 11A to 11E are present at the standby position.

  Furthermore, the workpiece pickup system 1 causes the vacuum cups 13 </ b> A to 13 </ b> E to be attracted to the blank 15 and pulled upward to bring the blank 15 into contact with the MGT belt 14 and drive the MGT belt 14. Transport in the transport direction A. Since the MGT belt 14 is magnetized, it adheres to the blank 15 with a magnetic force.

  In the present embodiment, the vacuum cups 13 </ b> A to 13 </ b> E descend sequentially from the vacuum cup 13 </ b> A positioned at the endmost in the direction opposite to the transport direction A in the order of 13 </ b> A, 13 </ b> B, 13 </ b> C, 13 </ b> D, 13 </ b> E.

  FIG. 2 is a plan view of the work pickup system 1 according to an embodiment of the present invention.

  FIG. 2 is a plan view of the workpiece pickup system 1 as viewed from above, in which a plurality of vacuum cups 13A to 13E are arranged between a plurality of (in accordance with an embodiment of the present invention) MGT belts 14. Yes. According to the embodiment of the present invention, the number of vacuum cups 13 disposed between each MGT belt 14 is five. The servo cylinders 11A to 11E, the support shafts 12A to 12E, the blank 15 and the support base 16 are not shown.

  FIG. 3 is a block diagram showing the relationship between the control device provided in the work pickup system 1 according to one embodiment of the present invention and the servo cylinders 11A to 11E.

  The servo cylinders 11A to 11E include motors 41A to 41E, respectively, and are electrically connected to the control device via the motors 41A to 41E. The motors 41 </ b> A to 41 </ b> E lower the servo cylinders 11 </ b> A to 11 </ b> E (down / up / stop) by receiving a drive control signal from the control device. As the servo cylinders 11A to 11E are lowered, the support shafts 12A to 12E and the vacuum cups 13A to 13E are lowered.

  The control device includes a lowering means 21, a detecting means 22, a comparing means 23, a stop control means 24, a laser measuring section 25, a storage section 26, a first raising means 27, a second raising means 28 and a blower means 29.

  The lowering means 21 transmits drive control signals for lowering the servo cylinders 11A to 11E to the motors 41A to 41E. The detection means 22 detects a physical quantity corresponding to the force with which the vacuum cups 13A to 13E press the blank 15 (in this embodiment, the current value flowing through the servo cylinders 11A to 11E).

  The comparison unit 23 compares the current value detected by the detection unit 22 with the reference current value. The reference current value is a current value corresponding to a force that presses the blank 15 with the suction force (hereinafter referred to as “required suction force”) necessary for each of the vacuum cups 13 </ b> A to 13 </ b> E to suck up the blank 15. It is. This reference current value is stored in the storage unit 26 in advance.

  The stop control unit 24 stops the lowering of each of the servo cylinders 11A to 11E when the current value flowing through each of the servo cylinders 11A to 11E reaches the reference current value according to the comparison result by the comparison unit 23.

  The first raising means 27 raises the servo cylinder 11A by a predetermined distance after the first and second descending vacuum cups 13A, 13B are attracted to the blank 15 with a necessary suction force.

  The second raising means 28 raises the servo cylinders 11 </ b> A to 11 </ b> E toward the standby position immediately after the last descending vacuum cup 13 </ b> E is attracted to the blank 15 with the necessary suction force. The air blowing means 29 sends air into the gap between the blanks 15 on the condition that the servo cylinder 11A is raised by the first raising means.

  FIG. 4 is a flowchart showing a control flow in which the control device lowers the servo cylinders 11A to 11E.

  In step S1, the servo cylinders 11A to 11E are sequentially lowered from 11A. As the servo cylinders 11A to 11E are lowered, the support shafts 12A to 12E and the vacuum cups 13A to 13E are also lowered.

  Here, the manner in which the servo cylinders 11A to 11E start to descend from the standby position will be described with reference to FIG.

  According to FIG. 5, the blank 15 is being transported in the transport direction A, and 11B and 11C are sequentially lowered from the standby position from the servo cylinder 11A at the endmost in the direction opposite to the transport direction A. On the other hand, the servo cylinders 11D and 11E are present at the standby position. The blank 15 being conveyed does not exist in the downward direction of the vacuum cups 13A to 13C, but still exists in the downward direction of the vacuum cups 13D and 13E. Here, the conditions under which the servo cylinders 11A to 11E start to descend are that the blank 15 being conveyed has passed the descending direction of the vacuum cups 13A to 13E.

  As described above, the lowering means 21 sequentially lowers the servo cylinders 11A to 11E on condition that the blank 15 being conveyed has passed the lowering direction of the vacuum cups 13A to 13E.

  In addition, in order to judge that the blank 15 in conveyance has passed the descending direction of each vacuum cup 13A-13E, a control apparatus measures the moving distance to the conveyance direction of the blank 15 (not shown). Is provided. As an example of the measurement method, the driving time is measured with the driving speed of the MGT belt 14 being constant, so that the product of the driving speed and the driving time is taken.

  Further, when the control device lowers each servo cylinder 11A to 11E, it reaches the middle from the standby position to the uppermost blank 15 (for example, half of the distance from the standby position to the uppermost blank 15). Should be accelerated and lowered and then decelerated. By doing in this way, while being able to shorten cycle time more, the impact at the time of each vacuum cup 13A-13E adsorb | sucking to the blank 15 can be decreased more.

  Returning to FIG. 4, in step S <b> 2, it is determined whether or not the vacuum cups 13 </ b> A and 13 </ b> B that have descended first and second have been attracted to the blank 15 with the necessary suction force. Specifically, it is determined whether or not each current value flowing through the servo cylinders 11A and 11B has reached the reference current value. If this determination is YES, the process of step S3 is performed, and if NO, the process of step S2 is performed.

  In step S3, the servo cylinder 11A that has been lowered first is raised by a predetermined distance and air is fed into the gap between the blanks 15.

  Here, with reference to FIG. 6, a state where the servo cylinder 11 </ b> A is raised by a predetermined distance and air is fed into the gap between the blanks 15 will be described.

  According to FIG. 6, the servo cylinder 11 </ b> A is raised by a predetermined distance, and air is sent into the gap formed by separating the end of the uppermost blank 15 from the next blank 15 by the blower. The vacuum cups 13 </ b> A and 13 </ b> B are attracted to the blank 15, but the vacuum cups 13 </ b> C to 13 </ b> E are descending and are not attracted to the blank 15.

  The trigger for the air blower to send air is that each current value flowing through the servo cylinders 11A and 11B has reached the reference current value. That is, the vacuum cups 13 </ b> A and 13 </ b> B descending first and second are adsorbed to the blank 15 with a necessary adsorbing force.

  Returning to FIG. 4, in step S <b> 4, it is determined whether or not all the vacuum cups 13 </ b> A to 13 </ b> E are attracted to the blank 15 with the necessary suction force. Specifically, it is determined whether each current value flowing through the servo cylinders 11A to 11E has reached the reference current value. If this determination is YES, the process of step S5 is performed, and if NO, the process of step S4 is performed.

  Here, with reference to FIG. 7, a state in which all the vacuum cups 13 </ b> A to 13 </ b> E are attracted to the blank 15 with a necessary suction force will be described.

  According to FIG. 7, all the vacuum cups 13 </ b> A to 13 </ b> E are attracted to the blank 15 with the necessary suction force, and the vacuum cup 13 </ b> A has already risen a predetermined distance. Therefore, there is no need to raise the vacuum cup 13A after the last lowered vacuum cup 13E is attracted to the blank 15 with the necessary adsorption force, so the vacuum cup 13E is raised immediately after the vacuum cup 13E is adsorbed with the necessary adsorption force. Can be made. Therefore, a wasteful waiting time until the vacuum cup 13E is raised after the vacuum cup 13E is attracted to the blank 15 with a necessary suction force is eliminated, and the cycle time can be shortened.

  The first raising means 27 may continue raising the vacuum cup 13A without raising the raising speed of the vacuum cup 13A after raising the vacuum cup 13A by a predetermined distance. As a result, it is not necessary to generate a larger acceleration necessary for once increasing the rising speed and then increasing it again, and the control burden on the control device can be reduced.

  Returning to FIG. 4, in step S5, all the servo cylinders 11A to 11E are raised. This is shown in FIG.

  FIG. 8 is a diagram illustrating a state where the servo cylinders 11A to 11E are being lifted. According to this figure, the vacuum cups 13A to 13E are attracted to the blank 15, and only one blank 15 is raised.

  Returning to FIG. 4, in step S6, it is determined whether or not all the servo cylinders 11A to 11E are in the standby positions. If this determination is YES, the process of step S7 is performed. If NO, the process of step S6 is performed.

  In step S7, the blank 15 is conveyed and the process of step S1 is performed during conveyance. The manner in which this processing is performed will be described with reference to FIG.

  FIG. 9 is a diagram illustrating a state in which the blank 15 is transported after the servo cylinders 11A to 11E return to the standby position. According to this figure, the blank 15 is attracted to the MGT belt 14 and conveyed in the A direction. Further, the blank 15 being transported has passed the descending direction of the vacuum cup 13A, and the servo cylinder 11A has started to descend.

  Thereafter, the blank 15 is conveyed by repeating the series of processes shown in FIG.

  According to this embodiment, there are the following effects.

(1) In the work pickup system, at least the first and second descending vacuum cups 13A and 13B are attracted to the blank 15 with the necessary attracting force, and the last descending vacuum cup 13E is attracted to the blank 15 with the necessary attracting force. Then, at least the vacuum cup 13A is raised by a predetermined distance, and immediately after the vacuum cup 13E is attracted to the blank 15 with the necessary suction force, all of the vacuum cups 13A to 13E are raised toward the standby position.
As a result, the wasteful waiting time from when the last lowered vacuum cup 13E is attracted to the blank 15 with the necessary attracting force until it rises is eliminated, and the cycle time can be shortened.
Further, the lowering means 21 sequentially lowers the vacuum cups 13A to 13E while the blank 15 is being conveyed. That is, since the vacuum cups 13A to 13E are lowered without waiting for the completion of the conveyance of the blank 15, the useless waiting time until the conveyance is completed is eliminated, and therefore the cycle time can be shortened.
Further, the first ascending means 27 adsorbs the vacuum cup 13 </ b> A, 13 </ b> B descending at least first and next to the blank 15 with the necessary adsorption force, and then finally descending the vacuum cup 13 </ b> E to the blank 15 with the necessary adsorption force. Before, at least the vacuum cup 13A is raised by a predetermined distance.
Therefore, since it can release from the edge part of blanks 15, double blanks can be prevented without providing the magnet floater for opening a clearance gap between blanks 15. FIG.

  (2) In the blower, the vacuum cup 13A descending at least first by the first ascending means 27 has risen, that is, the vacuum cups 13A, 13B descending first and next have been adsorbed to the blank 15 with the necessary adsorption force. Since air can be sent into the gaps between the blanks 15 on the condition, prevention of double blanks can be further strengthened.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

DESCRIPTION OF SYMBOLS 1 Work pick-up system 11A-11E Servo cylinder 12A-12E Support shaft 13A-13E Vacuum cup 14 MGT belt 15 Blank 16 Support stand 21 Lowering means 27 First raising means 28 Second raising means

Claims (2)

A work pick-up system for picking up and lifting a plurality of gripping means on a work,
Conveying means for conveying the workpiece in the conveying direction;
A plurality of gripping means provided in the transport direction;
During the transfer of the work by the transfer means , when the work being transferred passes in the descending direction of each gripping means sequentially from the gripping means positioned at the end opposite to the transfer direction , the work is started from the standby position. Descending means for descending toward the
A first ascent that raises at least the first descending gripping means by a predetermined distance before the gripping means descending at least first and next by the descending means is attracted to the work and the last descending gripping means attracts to the work. Means,
Second raising means for raising all of the plurality of gripping means toward the standby position immediately after the gripping means that descends last is attracted to the workpiece;
Work pickup system with The work pickup system according to claim 1,
It further includes a blowing means for sending air into the gap between the workpieces,
The work blowing system is characterized in that the air blowing means feeds air on condition that at least the first descending gripping means is raised by the first raising means.

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