JPH10258983A - Work holder of conveyance device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold a work with roughness stably in an as-processed position, release the work instantaneously by demagnetizing residual magnetism, and attain manufacturing at low cost. SOLUTION: This holder 1 includes a magnet chuck 9 which attracts a work, a joint bar 7 which is jointed to the magnet chuck 9, and a holding body 5 which is supported by the supporting part 3 of an arm. In a magnet body 6 which is disposed in the case of the holding body 5, an exciting coil 54 which is formed around two movable yokes 57 which are formed into U-shape with the joint bar 7 which is inserted in the magnet body 6, being put between them and the joint bar and wound around a bobbin 53, and a sliding guide member 58 of the joint bar 7 are formed. When the exciting coil 54 is energized, a magnetic pole is generated between the movable yoke 57 and the joint bar to attract and hold the joint bar 7. The exciting coil 54 involves a forward exciting coil and an inverse exciting coil, and when the forward exciting coil is released, the inverse exciting coil is actuated, thus it is possible to demagnetize residual magnetism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to transporting a work formed with undulations, and further relates to a work holding device of a transfer device for sucking and holding the work.

[0002]

2. Description of the Related Art Generally, when a workpiece is transported by a transport device, it is desirable that the workpiece be transported to a next process position while being processed. In particular, when the work is an iron plate-shaped work formed with undulations, when the work holding device of the transfer device grips the work, the work is inclined at the moment when the work is lifted and interferes somewhere. When the workpiece is dropped or transported while being tilted, the workpiece may interfere with any member during the transport.

Conventionally, various means have been employed in a holding device of a transfer device for transferring a work as described above. For example, a holding device 61 shown in FIG. 8 includes a plurality of magnet chucks 62 for attracting a work W, a connection bar 63 connected to each of the magnet chucks 62, and a support unit provided on an arm of the transfer device. And holding members 64 fixed to the holding members 60 and holding the respective connecting bars. The connecting bars 63 are connected to coil springs 65 mounted in the respective holding members 64. Then, when the arm of the transfer device is lowered and each of the magnet chucks 62 comes into contact with the upper surface of the undulating work W, each of the magnet chucks 62 is energized to attract the work W. When all the magnet chucks 62 attract the work W, the arm is lifted and lifts the work W. At this time, the work W is swung or tilted by the elastic force of the coil spring 65 and is conveyed in an unstable state. Although the holding device 61 has a simple structure and can be manufactured at a low cost, the state in which the holding device 61 is transported is extremely unstable, so that the work W may be interfered or dropped. Therefore, a holding device shown in FIG. 9 or FIG. 10 is known to solve this problem.

A holding device 71 shown in FIG. 9 has a structure in which the holding body 64 in FIG. 7 is replaced with an air cylinder 72, and a piston 73 of each cylinder 72 attached to a support portion 70 of an arm of the transfer device. Are lowered by the respective strokes in accordance with the upper surface of the undulating work W. When the magnet chucks 74 attached to the lower ends of the respective pistons 73 come into contact with the upper surface of each of the undulating works W, the valves provided in the air circuit are actuated to stop the movement of the pistons 73. Then, after the magnet chuck 74 attracts the work W, the arm of the transfer device is raised, and the work W is transferred to the next process while maintaining the processed posture.

[0005] The holding device 81 shown in FIG.
The holder attached to the support 80 of the arm of the transfer device is configured as a jack motor 82. A ball screw 83 is disposed downward in the jack motor 82, and a magnet chuck 84 is connected to a tip of the ball screw 83. When each jack motor 82 is driven, the ball screw 83 is lowered together with the magnet chuck 84. Each magnet chuck 84 is lowered by each jack motor 82 until it comes into contact with the upper surface of the work W.
When the driving of the jack motor 82 is stopped by the sensor disposed at the position W, the jack motor 82 stops at the contact position with the workpiece W. When the magnet chucks 84 are energized and the work W is attracted, the arm 80 is raised, and the work W is conveyed to the next process while maintaining the processed posture.

[0006]

However, the holding device 81 shown in FIG. 9 in which the holding body is a cylinder type requires a valve for switching air, the device becomes large, and when the work W is sucked and lifted. In addition, depending on the weight of the work W, the air is not fixed, and the piston 73 may move, which becomes unstable. If the air cylinder is changed to a hydraulic cylinder, the size of the apparatus becomes larger and costs increase.

When the holder shown in FIG. 10 is a jack motor 82, the magnet chuck 84
Since a sensor is required to detect the arrival at the upper surface of the device, this also leads to an increase in cost.

The present invention solves the above-mentioned problems, and stably holds and conveys a work formed with undulations while the work is processed.
When releasing the gripping of the workpiece, the workpiece can be released immediately,
Further, it is an object of the present invention to provide a work holding device of a transfer device that can be manufactured at low cost.

[0009]

A work holding device of a transfer device according to the present invention has the following configuration to solve the above-mentioned problems. That is, a work holding device of a transfer device that is attached to a distal end portion of the transfer device and suction-holds a work formed with undulations, and a plurality of grippers disposed so as to be able to suck the work, A connecting bar connected to each of the grip portions and slidably disposed, and a magnet body for stopping sliding of each of the connecting bars, wherein each of the magnet bodies includes a movable yoke and an exciting coil. Along with being provided, it is fixed to a support portion of the transport device, and the connection bar is arranged to be inserted while being guided into the magnet body,
The exciting coil and the movable yoke are arranged around the connection bar, and a magnetic pole is generated between the magnet body and the connection bar.

The work holding device of the transfer device is a work holding device of a transfer device which is attached to a tip portion of the transfer device and suctions and holds a work formed with undulations. A plurality of grippers disposed,
A connection bar connected to each of the grip portions and slidably disposed, and a magnet body for stopping the slide of each of the connection bars, and the magnet body includes a movable yoke and an exciting coil. The case is arranged so as to be slidable together with the connection bar in the case body fixed to the transfer device, so that magnetic poles are generated in the magnet body and the case body.

[0011] More preferably, the exciting coil may be configured to have a positive exciting coil and a reverse exciting coil.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a work holding device (hereinafter, referred to as a holding device) 1 of a transfer device of the present embodiment includes a holding member 5 fixedly attached to a support portion 3 of a transfer device arm. , Magnet body 6 disposed in holder 5
And a connecting bar 7 penetrating through the magnet body 6 and slidably disposed in the magnet body 6, and a magnet chuck 9 attached to a lower end of the connecting bar 7.

The connecting bar 7 is made of a magnetic material and has a rectangular cross section. One end of the connecting bar 7 is connected to the magnet chuck 9, and the other end of the connecting bar 7 is inserted through the support 3 of the arm and has a stopper 11 attached thereto. When the connecting bar 7 is moved downward, the connecting bar 7 stops at the lowermost position when the stopper 11 contacts the upper surface of the arm support 3.

The holder 5 has a mounting plate 52 mounted on the support portion 3 of the arm at the upper part thereof and a non-magnetic case 51 formed in a cylindrical shape and a bobbin 53 provided around the connecting bar 7. An exciting coil 54 to be wound, and a U-shaped magnetic movable yoke 57, which is disposed in two parts around the exciting coil 54 with the connecting bar 7 interposed therebetween and is moved to face in the left-right direction (FIG. 1) and the movable yoke 57.5
And guide members 58 that guide sliding slide bars 7 arranged at both upper and lower ends of the slide bar 7.
Then, the bobbin 53, the exciting coil 54, and the movable yoke 57
Are included in the magnet body 6. The guide members 58 are formed of a nonmagnetic material in a ring shape and are fixed to the case 51.

Therefore, when the exciting coil 54 is energized, magnetic poles are generated in the movable yoke 57 and the connecting bar 7, so that the movable yokes 57 move toward the connecting bar 7 and grip the connecting bar 7. . At this time, the movable yoke 57
Since the clearance between the shaft and the connecting bar 7 is extremely small, a large suction force acts and the holding force on the connecting bar 7 increases. However, since the residual magnetism also increases with this, the holding device 1
The excitation coil 54 is formed so as to be divided into a positive excitation coil 55 and a reverse excitation coil 56 and wound around the bobbin 53.

As shown in FIG. 3, the positive excitation coil 5
5, a power supply 55a and a switch 55b are wired in series,
The power supply 56a and the switch 56b are wired in series with the reverse excitation coil 56, and the switch 55b of the positive excitation coil 55 is connected.
Is turned off, the switch 56b of the reverse excitation coil 56 is always linked to be turned on. When the current value increases, the magnetic force increases, and the attraction force of the movable yokes 55 to the connecting bar 7 also increases. Thereafter, when releasing the suction gripping of the connecting bar 7, the switch 55 b of the positive excitation coil 55 is turned off, and at the same time, the reverse excitation coil 5 is turned off.
The switch 56b of No. 6 is turned on, a negative current of reverse excitation flows, the residual magnetism remaining between the movable yoke 57 and the connecting bar 7 is demagnetized, and the connecting bar 7 is immediately moved downward by its own weight.

This is shown by the BH curve of the magnetic circuit of FIG. The horizontal axis represents the magnetizing force (H), and the vertical axis represents the magnetic flux density. When the power supply 55a of the positive excitation coil 55 is turned on and the switch 55b is turned on, the current value increases, the magnetizing force (H) increases, and the magnetic flux density (B) also increases. In this case, it is assumed that the process is started from a state where there is no residual magnetism, and both the magnetizing force and the magnetic flux density rise from the zero position (P0) along the curve A in the figure due to the positive magnetization. When the magnetic flux density rises to a certain position, it saturates, and even if the magnetizing force further increases, the magnetic flux density maintains a substantially horizontal state. Then, the magnetizing force reaches the H + position. Next, by lowering the current value, the magnetization force decreases as shown by the curve B, and the magnetic flux density also decreases. However, only in the state where the switch 55b is turned off, the magnetic flux density Br exceeds the magnetizing force 0 position due to the effect of hysteresis. This appears as residual magnetism. To reduce the residual magnetism to zero, it is necessary to apply a minus magnetizing force for H1. Therefore, by passing the reverse excitation current, the residual magnetism is demagnetized and a C curve can be obtained. Next, when exciting the exciting coil 54, the switch 56b of the reverse exciting coil 56 is turned off, and the switch 55b of the positive exciting coil 55 is turned on. by this,
It moves from minus magnetization to plus magnetization, and P1 → D
→ Magnetic saturation occurs through the course of the A curve.

The operation of the reverse excitation coil 56 is released at an appropriate time by a timer. Further, the reverse excitation coil 56 may always be turned on without the switch 56b.

Next, the operation of the holding device 1 thus configured will be described with reference to FIG.

A plurality of (two in the illustrated example) holding devices 1A and 1B are arranged on the support portion 3 of the arm M of the transfer device. The holding devices 1A and 1B are lifted by the arm M and In the raised position. Undulating workpieces W processed by a press machine (not shown)
1. It is formed having a low position surface W2. In this state, since the excitation coil 54 of each holding device 1 is not energized, the movable yoke 57 is located at a distance with a gap without adsorbing the connecting bar 7. Therefore, each connecting bar 7 is moved to the lowermost end by its own weight. When the arm M descends, the magnet chuck 9A disposed at the lower end of the holding device 1A corresponding to the high position surface W1 of the work W first reaches the high position surface W1 of the work W. When the arm 3 is still lowered, the connecting bar 7A slides upward in the holding body 5A, and the magnet chuck 9B of the holding device 1B is further lowered and moved toward the upper surface of the low position surface W2 of the work W. . Then, after the magnet chuck 9B reaches the upper surface of the low position surface W2 of the work W and further lowers slightly, the lowering of the arm M stops. Therefore, the connecting bar 7B slides slightly upward in the holder 5B. In this state, the magnet chuck 9 is energized and the holders 5 are also energized. When the positive exciting coil 55 of the exciting coil 54 is energized, a magnetic pole is formed between the movable yoke 57 and the connecting bar 7, and the movable yoke 57 moves to the connecting bar 7, and then the connecting bar 7 is attracted and gripped. As described above, since the magnetic flux passing through the movable yoke 57 and the connecting bar 7 is large and the attraction force is large, the connecting bar 7 is firmly fixed. Then, work W
The arm M rises and the work W is transported to the next step while the magnetic chuck 9 is being attracted to the magnet chuck 9. Since the work W is lifted and conveyed in a posture as it is processed, there is no danger that the work W will fall from the magnet chuck 9 and no interference will occur.

The work W conveyed to the next step is dropped into the next step stocker (not shown) when the power supply to the magnet chuck 9 and the holder 5 is released. At the same time, the positive excitation coil 55 of the holder 5 is de-energized and the reverse excitation coil 56 is reverse-excited, so that the residual magnetism generated between the movable yoke 57 and the connection bar 7 is immediately demagnetized, and the connection bar 7 The stopper 11 is moved downward by its own weight until it comes into contact with the upper surface of the support portion 3 of the arm M. Then, the workpiece W is moved to the upper surface position again.

Therefore, according to the present embodiment, the work W is attracted to the magnet chuck 9 and the connecting bar 7 to which the magnet chuck 9 is attached is held by the holder 5 with a sufficient attraction force. It is transported stably with the machined posture. Further, the connection bar 7 can be immediately released from the holding body 5 by suction.

The structure of the holding device is not limited to the above-described embodiment, and may be, for example, the holding device 15 shown in FIGS.

The holding device 15 includes a holding member 20 fixedly attached to the support portion 3 of the transfer device arm, and a holding member 20.
It has a magnet body 21 that slides inside, a connection bar 22 attached to the magnet body 21, and a magnet chuck 9 attached to the lower end of the connection bar 22.

The connecting bar 22 is made of a magnetic material and has a round cross section. One end of the connecting bar 22 is connected to the magnet chuck 9, and the other end is connected to the lower end of a magnet body 21 that slides inside the holding body 20. The holding body 20 includes a cylindrical magnetic case 23 having a mounting plate 24 mounted on the support portion 3 of the arm at the upper part thereof, a substantially cylindrical main pole 25 sliding in the case 23, An exciting coil 27 wound around the outer peripheral surface of the pole 25 via a bobbin 26, a movable yoke 30 of a magnetic material which is disposed at the upper and lower ends of the main pole 25 and is formed into four parts on each side, A magnet body 21 having a nonmagnetic ring-shaped guide member 33 disposed between the movable yoke 30 and the bobbin 26 disposed in the case 23 and guided by the case 23, and a downward movement of the connection bar 22 disposed below the case 23 Stopper 34 formed as an end of
, And is configured.

The main pole 25 has a groove formed in the center of the outer periphery.
A bobbin 26 is disposed in the groove, and guide members 33 are disposed at both ends of the outer periphery of the main pole 25. Further, the movable yoke 30 arranged on the upper surface of the main pole 25 is restricted from moving in the axial direction (vertical direction in FIG. 6) by the stopper member 35, and each of the four divided movable yokes is orthogonal to the axis. (The left-right direction in FIG. 6). The movable yoke 30 arranged on the lower surface side of the main pole 25 is regulated in the axial direction by a flange portion 22a formed at the upper end of the connecting bar 22, and each movable yoke divided into four parts has an axial center. It is arranged so as to be movable in a direction orthogonal to. Although the movable yoke 30 is divided into four parts in this embodiment, the present invention is not limited to this. The movable yoke 30 may be divided into two parts or three parts.

Therefore, when the excitation coil 27 is not energized, the magnet body 21 is not attracted to the case 23, and the lower surface of the flange portion 22a of the connecting bar 22 is provided by the stopper 34 provided in the case 23 by its own weight. It is moved down until it contacts the upper surface. Further, when the magnet chuck 9 contacts the work W and the connecting bar 7 is lifted by the work W and the excitation coil 27 is energized, the main pole 25, the movable yoke 30,
Since a magnetic pole is generated in the case 23, the movable yoke 30 is moved toward the case 23, and the case 23 and the main pole 25 are attracted via the movable yoke 30, and the connecting bar 22 stops its vertical movement. Will be done. At this time, since the clearance between the movable yoke 30 and the case 23 is extremely small, a large attracting force acts and the holding force on the magnet body 21 also increases.

Also in this embodiment, the exciting coil 27 has a positive exciting coil 28 and a reverse exciting coil 29, and the mode is the same as that of the holding device 1 described above. Further, the operation of the holding device 15 for sucking and transporting the workpiece W is substantially the same as that of the above-described holding device 1 except for a portion where a magnetic pole is generated, and thus the description thereof is omitted.

In this embodiment, the movable yoke 3
0 as a guide member formed of a non-magnetic material
2 and the guide member 33 may be formed integrally with the main pole 25 so that the cross section is divided into four like the movable yoke. Further, the connection bar 22 may be formed in a rectangular shape.

[0031]

According to the holding device of the present invention, the work is attached to the leading end of the transfer device and suction-holds the work formed with undulations. The work is arranged to be able to suck the work. A plurality of gripping parts, a connecting bar connected to each gripping part and slidably provided, and a magnet body for attracting and holding each of the connecting bars are provided. The connection bar is slidably inserted into the magnet body, and is configured to generate a magnetic pole between the magnet body and the connection bar. Then, in a state where the magnet body is not excited, each connecting bar is moved to the lowermost end together with the gripping portion by its own weight, and in a state where each connecting bar is moved upward with respect to each holding body. When the magnet body is excited, the magnet body acts so as to attract and hold the connection bar. Therefore, each connecting bar is firmly supported by the magnet body and can lift and convey the work, so that the work maintained in the processed posture can be stably conveyed. Further, since the sensor does not require a sensor or a valve when the grip portion reaches the work, it can be manufactured at low cost.

Further, according to the holding device of the present invention, the work is attached to the leading end portion of the transfer device and sucks and holds the work formed with undulations, and the case body fixed to the transfer device. A plurality of gripping portions arranged so as to be able to adsorb the work, a connecting bar connected to each of the gripping portions and slidably provided, and a magnet body which sucks and holds each of the connecting bars. , Is provided. The connection bar is connected to the magnet body slidably disposed in the case body, and is configured to generate a magnetic pole between the magnet body and the case body. And, in a state where the magnet body is not excited, each connecting bar is moved to the lowermost end together with the holding part by its own weight together with the magnet body, and each connecting bar is moved upward with respect to each holding body. When the magnet body is excited in the state in which the case body is in the state, the magnet body acts so that the case body can be attracted and held. for that reason,
The connection bar connected to each of the magnet bodies is
Since the workpiece can be lifted and transported firmly supported by the case body, the workpiece maintained in the processed state can be transported stably. Further, since the sensor does not require a sensor or a valve when the grip portion reaches the work, it can be manufactured at low cost.

Further, since the exciting coil constituting the magnet body has a positive exciting coil and a reverse exciting coil, even if the magnet body is de-energized, a negative current for reverse exciting flows, Can immediately demagnetize the residual magnetism,
The next operation can be started immediately.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a holding device according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a wiring diagram showing an exciting coil in FIG. 1;

FIG. 4 is a graph showing a BH curve of a magnetic circuit.

FIG. 5 is a diagram showing a state in which a workpiece is suctioned and conveyed using the holding device of FIG. 1;

FIG. 6 is a front sectional view showing a holding device according to another embodiment of the present invention.

7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 shows a conventional holding device.

FIG. 9 is a view showing another conventional holding device.

FIG. 10 is a diagram showing another conventional holding device.

[Explanation of symbols]

 1, 15: Holder 5, 20: Holder 6, 21: Magnet 7, 22: Connection bar 9: Magnet chuck 12, 39: Support 23, 51: Case 25, Main pole 27, 54: Exciting coil 28, 55: forward excitation coil 29, 56: reverse excitation coil 30, 57: movable yoke 33, 58 ... guide member

Claims (3)

[Claims] 1. A work holding device for a transfer device, which is mounted on a tip portion of a transfer device and suction-holds a work formed with undulations, comprising a plurality of grippers disposed so as to be able to suck the work. And a connecting bar connected to each of the gripping portions and slidably provided, and a magnet body for stopping the sliding of each of the connecting bars, and each of the magnet bodies includes a movable yoke. An excitation coil is provided, and is fixed to a support portion of the transfer device, the connection bar is arranged to be inserted while being guided into the magnet body, and the excitation coil and the movable yoke are arranged around the connection bar. A work holding device for a transfer device, wherein the work holding device is arranged so that a magnetic pole is generated between the magnet body and the connection bar. 2. A work holding device of a transfer device, which is attached to a tip portion of a transfer device and suction-holds a work formed with undulations, wherein a plurality of grippers are provided so as to be able to suck the work. , A connecting bar connected to each of the gripping portions and slidably provided, and a magnet body for stopping the sliding of each of the connecting bars, wherein the magnet body is a movable yoke and an exciting coil. And a transport device that is slidably disposed along with the connection bar in a case body fixed to the transport device, and is configured to generate magnetic poles in the magnet body and the case body. Work holding device. 3. The work holding device according to claim 1, wherein the exciting coil includes a positive exciting coil and a reverse exciting coil.