JPH04372389A - Hand for picking up plate workpiece - Google Patents

Abstract

PURPOSE:To provide a hand for a manipulartor in which a plate workpiece is gripped so that a vertical coordinate value of the position of the plate workpiece in a three-dimensional space is fixed at a predetermined value, and the workpiece position a two-dimensional coordinate is caught by a camera so as to know a difference between it and a reference workpiece position in a two-dimensional coordinate, and the difference is corrected so that the workpiece is carried to a next process. CONSTITUTION:A first workpiece gripping means 20 that is not moved laterally, and a second workpiece gripping means 40 that can be moved laterally, are provided on a hand frame 12, while lifting of a plate workpiece W by means of the gripping means 20, 40, the gripping, and the workpiece position in the vertical coordinate direction are set by vertically moving cylinder 22, 42, and a reference position HL of the set workpiece W is found by a camera 60 and a difference between it and a reference position taught is found, and the workpiece is carried to a next process and is positioned so that the difference is corrected. Since the working position is known not in a three-dimensional mode but in a two-dimensional mode, the carrying to the next process and the positioning are simplified, and the cost is reduced thereby.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is used as an end effector for industrial robots, work loaders, etc., and is used to convert plate workpieces with unevenness into desired parts by press working or sheet metal working into a laminated state. Regarding the hand for picking up plate workpieces that can be picked up and held in sequence, it is particularly useful when picking up plate workpieces from a stacked state, gripping and conveying them to the processing position or assembly processing position of the next process, and positioning them. Among the postures defined by the orthogonal three-axis coordinate system in the three-dimensional space of the plate work, the posture of the vertical axis coordinate system is set to a predetermined fixed posture, and the workpiece position in the horizontal orthogonal two-dimensional coordinate system is determined using a camera. The present invention relates to a hand for picking up a plate work that can be captured, recognized the deviation from the reference work position, and positioned and placed at a predetermined position with correction.

0002

[Prior Art] For example, in automated production sites, plate workpieces used as parts for automobile bodies are pressed and then stacked in large numbers on pallets for use at the next machining site or for car body assembly. transported to the line. Because such plate workpieces have irregularities and assembly holes formed on their surfaces, when they are delivered in a stacked state to a machining site or assembly line at an automation site, the floor becomes rougher as you go from the lower layer to the upper layer. It is tilted to the surface.

[0003] In so-called depalletizing, in which a plurality of plate workpieces in a stacked state are sequentially picked up one by one from the top and transported to the next process, a hand is used as an end effector of an industrial robot or work loader. use That is, a method is often adopted in which a plate workpiece is picked up and held by a vacuum suction type or magnetic suction type gripping means provided at the tip of the hand. However, when a loader or robot picks up and grips a plate workpiece by hand and transports it to the next process machine or assembly process, the plate workpiece is always given a predetermined gripping posture, and the workpiece is placed on the machine's work table or on the assembly line. It is necessary to position it to the other workpiece.

0004

[Problem to be Solved by the Invention] Due to this necessity, in the conventional conveyance of plate workpieces, an operator manually holds each plate workpiece picked up from a stacked state using a mechanical forcing device. In many cases, the gripping posture is given before conveyance to the next process, resulting in intervention in the work process that goes against automation.

On the other hand, when a plate workpiece is picked up and gripped by the hand, three cameras are used to capture images of three points set on the workpiece in a three-dimensional coordinate system to teach the gripping posture of the workpiece in advance. A method of comparing the image with a standard 3D posture image to find the difference, making corrections, and then transporting it to the next process is also being researched and considered, but the method of obtaining a 3D image makes full use of as many as three cameras. A complex image processing device that processes images captured by these devices in a complex manner is required, and it is difficult to easily put into practice and provide a device for detecting and correcting the workpiece posture.

Therefore, an object of the present invention is to provide a two-dimensional gripping posture while gripping a plate workpiece that has been changed from a flat plate state into a component state having irregularities and holes by processing, and to The present invention attempts to solve the conventional problems by providing a hand for picking up plate workpieces that can correct the posture and transport the workpiece to the next process by capturing the detection point in a two-dimensional image.

[0007]

[Means for Solving the Problems] In view of the above-mentioned objects, the present invention provides a method in which each plate workpiece is picked up from a stacked state and gripped in a three-dimensional coordinate system gripping posture of plate workpieces in a three-dimensional space. In this state, the hand itself is equipped with a mechanism that keeps the coordinate value in the vertical axis direction constant, and the position of the set detection point position of the plate workpiece in the orthogonal plane coordinates is captured as an image, and the position data taught in advance is When transporting the workpiece held by the hand to the next process, it is possible to calculate the difference in the same orthogonal plane coordinate system and correct the difference and supply it onto the work table of machining equipment or the other workpiece on the assembly line. This is how it was done.

That is, according to the present invention, each workpiece is picked up from a stack of plate workpieces having unevenness, is gripped, and the posture of the workpiece is fixed to a predetermined posture at least in the vertical coordinate posture in the orthogonal three-dimensional coordinate posture. The hand for picking up plate workpieces can be set in a posture to be fed to the next process, and includes a hand frame that can be attached to a movable body such as a work loader, and a first vertically moving cylinder fixed to the hand frame. It is attached to the lower end via a universal joint, and comes into contact with the work surface of the plate by the downward movement of the vertical movement cylinder.
A first workpiece gripping means that performs a gripping operation, and a second vertically movable cylinder held on the hand frame so as to be able to move horizontally by a predetermined amount are provided at the lower end of the vertically movable cylinder via a universal joint, and the vertically movable cylinder is provided with a downward movement of the vertically movable cylinder. The plate is brought into contact with the work surface,
a second workpiece gripping means that performs a gripping operation;
When the plate workpiece picked up and gripped by the workpiece gripping means is raised together with the hand frame from the stack of workpieces, the first and second vertically movable cylinders are moved downward naturally or under pressure. stopper means provided to set the ordinate orientation of the plate workpiece to a predetermined orientation; and the workpiece picked up and gripped by the first and second gripping means, the ordinate orientation of the workpiece being set to the predetermined orientation. At this time, a fixing means provided to prevent horizontal movement of the second horizontally movable vertical cylinder having the second gripping means, and a fixing means provided to prevent horizontal movement of the second vertically movable cylinder having the second gripping means; Picking up of a plate workpiece, comprising a camera means for capturing an image of a reference point set in advance on the work surface of the plate workpiece that is picked up and held by the workpiece gripping means of 2 and set in the predetermined posture. A hand is provided. Note that the first and second workpiece gripping means are formed by a workpiece gripping means comprising a vacuum suction type pad or a workpiece gripping means comprising a magnetic suction type gripper.

[0009]

[Operation] The plate work is moved between the first vertical cylinder and the second cylinder.
The first and second work gripping means attached to the lower end of the vertically movable cylinder via a universal joint pick up each work piece from the stack in an inclined posture and grip it, and after gripping,
By the vertical movement of the first and second vertically movable cylinders and the lateral movement of the second vertically movable cylinder and the second workpiece gripping means, the ordinate posture of the workpiece is set to a predetermined posture and fixed at that posture. In this state, the camera means reads the reference points such as reference holes selected in advance on the plate work as coordinate values in the plane coordinates, calculates the difference from the plane coordinate values of those reference holes taught in advance, and The hand is corrected by the difference value and is transported to the next process by a transport operation of a robot, work loader, etc. equipped with the same hand. Hereinafter, the present invention will be described in more detail based on embodiments shown in the accompanying drawings.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view and a side view showing the overall structure of a hand for picking up a plate work according to the present invention.
FIG. 2 is a partial mechanical diagram showing a cross-sectional view of the structure of the first workpiece gripping means that is operated by a vertical cylinder provided in the same hand, and FIG. FIG. 4 is a partial mechanical diagram showing a cross-sectional view of the configuration of the second workpiece gripping means that can be moved laterally, and FIG.
(4) - (4) A plan view of the second workpiece gripping means as seen from the line, FIG. 5 is an enlarged view of the G part in FIG. 3, FIG. 6 is a fluid circuit of the vertical cylinder, and FIG. , an explanatory diagram showing a process in which the ordinate orientation of a plate workpiece gripped by the first and second workpiece gripping means of the hand is set to a predetermined orientation;
FIG. 8 is a perspective view of a workpiece processed into a vehicle body chassis part as an example of a plate workpiece.

First, referring to FIG. 8, there is shown an example of a plate work to be picked up and held by the hand according to the present invention. As is clear from this illustrated example, the plate workpiece W is generally produced as a sheet metal part in which irregularities, through holes and tap holes of various diameters, etc. are formed by processing, and a large number of such plate workpieces W are produced. , In the process of sending to the next processing or assembly process, the same work W is stacked on a pallet etc. in a stacked state and accumulated in a fixed place, and from there,
Each piece is picked up and gripped by a hand, and transported by a manipulator machine such as a robot or work loader onto a processing machine for the next process or onto a mating workpiece on an assembly line.

[0012] In the hand according to the present invention, when a large number of plate workpieces W having such unevenness are stacked, the upper workpieces are stacked in a state that is more inclined with respect to the floor surface or workpiece placement surface. When picking up and gripping the workpieces one after another from the stacked body, the same workpiece W is
A vacuum suction type pad or a magnetic suction gripping piece is lowered as a workpiece gripping means into the gripping area S illustrated in the hatched area on the surface of As will be described later, the object is held in a predetermined gripping posture, the position is corrected using a two-dimensional coordinate system in a horizontal plane, and the object is transported to the next process. In addition, the following description will also be explained using the case where each workpiece W is picked up and held from the stack of plate workpieces W shown in FIG. 8, and at that time,
A hole HL selected in advance among a large number of holes will be described as a detection hole that is imaged as an image for position detection in a two-dimensional coordinate system.

Now, FIGS. 1(a) and 1(b) are a plan view and a side view showing the basic structure of a hand 10 for picking up a plate workpiece W according to an embodiment of the present invention, and the former figure is a , is a plan view seen in the direction indicated by arrows FF in the latter figure. In addition, FIG. 3B shows that plate workpieces W are stacked in a stacked state, and the slopes of the upper layer workpiece and the lower layer workpiece are different due to the presence of unevenness. The hand 10 includes a hand frame 12 having an appropriate shape such as a plate shape or a girder frame shape.
A mounting flange 14 formed at one end of the hand frame 12 allows the hand 10 to be mounted as an end effector to the wrist tip of an industrial robot (not shown) or the tip of an automatic loader using the mounting hole 14a. configured to be possible.

The hand frame 12 of the hand 10 is equipped with a workpiece gripping means as a direct means for picking up and gripping a plate workpiece. The first workpiece gripping means 20 approaches the gripping area S of the workpiece W by suction and picks up and grips the workpiece W, and the hand frame 12 holds the workpiece W so that it can be moved horizontally by a certain amount in a plane. The second cylinder approaches the gripping area of the workpiece W by the operation of the vertically moving cylinder and picks up and grips the workpiece W in the same suction type.
In this embodiment, there is one first workpiece gripping means 20 and two second workpiece gripping means 40, which are connected to the hand frame 1.
The structure is such that the uppermost plate workpiece W of the laminate is picked up by separating and arranging it at three points (2) and using suction type gripping action at the three points. However, if necessary, or for a small plate work, the latter second work gripping means 4 may be
It is also possible to use a total of two gripping means to pick up the workpiece by using one gripping means. Note that, in FIG. 1A, a triangular region indicating a range in which the second workpiece gripping means 40 can be moved laterally is illustrated with a dotted line.

[0015] The hand frame 12 further includes the first
The second workpiece gripping means 20, 40 picks up the plate workpiece W, grips it, and holds it in a fixed gripping posture as described later. The position of a predetermined reference point HL (see FIG. 8) formed on the surface of the plate workpiece W at the time when the ordinate value in the workpiece posture determined by the coordinate value with the orthogonal ordinate axis is set to a predetermined value is captured as an image. , two cameras 60 that can be captured are provided. Of course, hand frame 1
Needless to say, the movement of 2 itself is controlled and accomplished by manipulator means such as a robot or a work loader to which it is attached. Furthermore, the captured image of the camera 60 is transmitted to an image processing device (not shown), and the image processing device may be any device capable of reading the coordinate values of the image of the reference point HL in the plane coordinate system within the display. Since many image processing apparatuses of this kind have already been proposed and provided, a detailed description thereof will be omitted here.

Next, the above-mentioned first workpiece gripping means 20
, the configuration of each of the second workpiece gripping means 40 will be explained below, including the configuration of the corresponding vertical movement cylinder for operation. Figure 2
2 shows the configuration of the first workpiece gripping means 20 held on the hand frame 12, and includes a double rod-type vertically movable cylinder (first A workpiece consisting of a vacuum suction pad or a magnetic suction gripping piece attached to the lower end of the lower rod 24a of the vertical movement cylinder 22 via a universal joint 26 such as a well-known universal joint. The gripping tool 28, the mechanical stopper member 30 attached to the upper end of the upper rod 24b protruding above the vertically movable cylinder 22, and the mechanical stopper member 30 provided on the upper surface of the hand frame 12 and mechanically engaged with the stopper member 30 to A stop setter 32 and the like are provided to set the downward movement limit of the upper rod 24b of the vertical movement cylinder.

The first workpiece gripping means 20 having the above-mentioned configuration has the hand 10 itself positioned at a predetermined position above the laminated plate workpiece W by the manipulator, and the vertically movable cylinder 22 is injected with working fluid. The lower rod 24a is gradually and slowly moved down to grip the workpiece gripper 28.
When it is attached to the surface of the plate workpiece W, the gripping area S of the workpiece W is automatically gripped by suction. At this time, the universal joint 26 has the effect of causing the suction surface of the workpiece gripping tool 28 to follow the inclination of the workpieces W in the stacked state, and therefore, if the workpiece W is thin, the workpiece W may be damaged. It can be picked up and held without giving. Note that when the work gripping tool 28 grips the plate work W and the hand 10 is pulled upward,
Working fluid is supplied to the vertical moving cylinder 22 via natural descent or a working fluid circuit described below until the stopper member 30 of the upper rod 24b of the vertical moving cylinder 22 engages with the setter 32. Move down.

FIGS. 3 to 5 show the configuration of the second workpiece gripping means 40 described above, in which two pieces are arranged so that the triangular opening 16 formed in the hand frame 12 can be moved laterally. A double rod type vertically moving cylinder (second vertically moving cylinder) 42 held by the clamping plates 50, 50 of the lateral movement mechanism composed of clamping plates 50, 50 and a ball 52 is provided, and this vertical movement A vacuum suction pad or magnetic suction type gripping tool 48 similar to the previous work gripping tool 28 is attached to the lower end of the lower rod 44a of the cylinder 42 via a universal joint 46. Further, a stop plate 54 is attached to the upper end of the upper rod 44b of the vertically moving cylinder 42, and works in cooperation with a setter not shown in the figure to prevent the vertically moving cylinder 42 from moving vertically while the work gripping tool 48 grips the plate work W. The amount of downward movement of the workpiece gripping tool 48 due to the operation of the cylinder 42 or its natural descent is regulated to a predetermined value, so that the ordinate value of the posture of the workpiece W can be set to a predetermined posture.

On the other hand, as clearly shown in FIG.
The workpiece gripping tool 4 can also be moved laterally, but if necessary, for example, at the stage where the hand 10 is initially positioned above the loaded plate workpiece W, the workpiece gripping tool 4
When the lateral movement of the cylinder 8 is restrained to prevent free movement, the V block body 5 provided at the tip of the lateral movement cylinder 56 is used.
6a, the vertically movable cylinder 42 can be restrained and held at a predetermined original position pressed against the wall surface of the opening 16.

The lateral movement is restrained by the lateral movement cylinder 56 when the hand 10 is placed at a predetermined position above the stacked workpieces W, that is, the plate workpiece W is held by the workpiece gripper 48.
When the workpiece gripping tool 48 reaches the starting position of the gripping action, the rod of the lateral movement cylinder 56 is moved backward to release the restraint on the lateral movement of the work gripping tool 48 in the horizontal plane.

The horizontal movement of the work gripping tool 48 in the horizontal plane is such that when the plate work W is picked up and gripped in cooperation with the work gripping tool 28 of the first work gripping means 20 described above, As described above, in the process of setting the vertical coordinate value in the workpiece posture to a predetermined value, the horizontal distance displacement between the workpiece gripping tools 28, 48, 48 is changed to the workpiece that can be moved in the same horizontal direction. This is compensated by the lateral movement of the gripping tool 48 to prevent deformation of the plate work W itself. Therefore, after the compensation operation due to the lateral movement is completed, it is necessary to fix the vertical movement cylinder 42 horizontally so that the lateral movement no longer occurs. Lateral movement fixing cylinder devices 58, 58 capable of fixing movement are provided at both ends of the stopper plate 54. The horizontal movement fixing cylinder devices 58, 58 are equipped with a fixing pad 58b attached to the upper end of a cylinder rod 58a extending vertically upward through a triangular window 54a formed in the stopper plate 54. When pressed against the stopper plate 54, the vertically movable cylinder 42 and the work gripper 48 are fixed via the stopper plate 54. Note that the triangular window 54a of the stopper plate 54 is connected to the vertically moving cylinder 4.
2, the upper rod 44b of the vertically moving cylinder 42
The stopper plate 54 itself, which is attached to the hand frame, is also provided so that it can move laterally, and has an area slightly larger than the opening area of the triangular opening 16 of the hand frame that regulates the range of lateral movement of the vertical movement cylinder 42. It is formed as a window. FIG. 5 is a partial perspective view showing in detail the portions of the lateral movement fixing cylinder device 58, the fixing pad 58b, and the triangular window 54a, which are circled in FIG. 3.

FIG. 6 shows the configuration of a fluid operating circuit that operates the vertically moving cylinders 22 and 42 in the first and second workpiece gripping means 20 and 40 described above, and such a circuit itself is connected to the hand frame 12. Fully equipped. The fluid working circuit uses a working fluid (in a preferred embodiment, pressurized air) in an upper or lower chamber defined by a piston 23 or 43 of a double rod type cylinder 22 or 42, and a vertically moving cylinder 22, 42 consisting of a pneumatic cylinder. In this case, the circuit is configured to supply a pressure switching solenoid valve 70, a pressure regulator 72 with a check valve,
Chamber switching control solenoid valve 7 that switches the supply of working fluid to the cylinder 22 or 44 between the upper chamber and the lower chamber to control the downward movement forward or upward movement movement of the lower rod 24a or 44a.
4, etc., and is connected to a working fluid source (not shown).

This fluid operating circuit includes a pressure switching solenoid valve 7.
When 0 is switched to the position shown in FIG.
The pressure regulator 72 with a check valve controls the working fluid to a low pressure state and supplies it to the chamber switching control solenoid valve 74. On the other hand, when the pressure switching solenoid valve 70 is switched from the position shown in FIG. Since the air does not pass through the pressure regulator 72 with a check valve, it is supplied to the room switching control solenoid valve 74 while maintaining its high pressure. The chamber switching control solenoid valve 74 supplies working fluid to the lower chamber of the cylinder 22 or 42 in the position shown in FIG. 6, and supplies working fluid to the upper chamber when switched.

According to such a working fluid circuit, for example, when a working fluid whose pressure is set to a low pressure state is supplied to the upper chamber of the cylinder 22 or 42 and the working fluid is discharged from the lower chamber, the lower rod 24a or 44a By slowly moving the work gripper 28 or 48 downward, the workpiece gripper 28 or 48 can be moved downward at a slow speed. Conversely, if necessary, the lower rod 24a or 44a can be moved upward at a high speed, and the work gripping tool 28 or 48 can be pulled up at a high speed.

The operation of picking up, gripping, and setting the posture of a plate work W by the hand 10 of this embodiment having the configuration described above will be explained with reference to FIGS. 1 to 6 as well as FIG. 7. First, when picking up and gripping the plate workpiece W in a stacked state as shown in FIG. 1(b), the hand 1
0 is attached to a manipulator such as an automatic loader or an industrial robot, and reaches a predetermined standby position above the workpiece taught in advance. At this time, the first and second workpiece gripping means 20, 40, 40 of the hand 10 are placed in a standby state approximately above the gripping area S of the plate workpiece W, but in the process of moving to the standby position, the hand frame 12 A vertically movable cylinder 42 capable of lateral movement within a horizontal plane and a second workpiece gripping means 4
0 and 40 are temporarily fixed in the original position in contact with the wall of the triangular opening 16 of the hand frame 12 by the operation of the lateral movement cylinder 56, and the second workpiece gripping means 40 is held in a state where it does not wobble. Ru.

When the standby state is reached, the first
By supplying low-pressure working fluid to the upper chambers of the vertically movable cylinders 22, 42, 42 in the second workpiece gripping means 20, 40, 40, the workpiece grippers 28, 48, 48 are moved downward at a slow speed, and gradually The workpiece is brought close to the top layer of the stack of plate workpieces W. Then, the work gripping tools 28, 4
8 and 48 are attached to the gripping area S of the uppermost plate work W and grip the work W by suction. At this time, the workpiece stack is in a tilted state as it goes up, but since the stroke amounts of the vertical motion cylinders 22, 42, and 42 are each set as the teaching amount in advance, the tilt can be compensated and absorbed. be able to.

Workpiece gripper 28 that is attached to the surface of workpiece W
, 48 are brought into close contact with the workpiece surface by the universal action of the universal joints 26, 46, 46 and the vacuum adsorption or magnetic adsorption action. The left view of FIG. 7 shows the state of the plate work W picked up and gripped by the hand 10 in this manner. Note that in the left diagram of FIG. 7, the distance L is between the workpiece gripper 28 and the other two
This figure shows the distance (pitch) between two laterally movable workpiece grippers 48, 48.

Next, the hand 10 is pulled upward again by the operation of the manipulator. At this time, the top layer plate work W is picked up by the work gripping tools 28, 48, 48,
They move upward together while being grasped. During this rising process, low-pressure controlled working fluid is again supplied to each of the vertically moving cylinders 22, 42, 42. As a result, the work gripping tools 28, 48, 48 gradually move downward, and therefore the posture of the plate work W in the three-dimensional space changes. This change in the posture of the workpiece W is toward a previously taught posture, that is, the stopper member 30 of the vertical movement cylinder 22
and the stopper plate 54 of the vertically moving cylinders 42, 42 mechanically engage with the setter 32, etc., and the lower rods 24a, 44a, 44
The posture displacement of the workpiece W continues until the position where the downward movement of the workpiece a is stopped, and at the time of stopping, the workpiece W assumes the non-tilted posture shown in the right-hand diagram of FIG. 7 in which the vertical axis coordinates are set in advance to predetermined coordinate values. Such a non-tilted posture (the ordinate value is fixed) is also the posture in which the plate workpiece W is transported to the next process.

In such a process of setting the workpiece posture, the plate workpiece W gripped by the workpiece grippers 28, 48, 48 changes its posture in accordance with the downward movement of the vertically movable cylinders 22, 42, 42. Gripping tools 28 and 48, 48
If the pitch L between them does not change, strain will be applied to the workpiece. However, in the present invention, since the second workpiece gripping means 40 is configured to be able to move laterally, the pitch L is displaced to L+α as shown on the right side of FIG. 7, and the deformation of the workpiece W is prevented. Ru. In the process of reaching this state, the pressure switching solenoid valve 70 switches the low-pressure working fluid supply of the working fluid circuit to the normal pressure working fluid supply side where the pressure regulator 72 with a check valve does not intervene, and the mechanical stopper action is performed. It stops at the activated position.

Next, the second workpiece gripping means 40, 40
The side lateral movement and fixing cylinders 58, 58 are operated to fix the second workpiece gripping means, and therefore, the posture of the plate workpiece W is fixed to the conveyance posture to the next process, that is, the ordinate value is fixed to a predetermined value. Fix it in that position. Next, the cameras 60, 60 included in the hand 10 take an image of the hole position HL, which has been selected in advance as the reference point position of the plate workpiece W. That is, since the vertical coordinates of the cameras 60, 60 are fixed at a predetermined value, the distance between them and the workpiece surface is always constant in the vertical direction, and the reference hole position HL on the surface of the workpiece W is set in the orthogonal coordinate system in the plane. It can be captured as a position at . In other words,
The cameras 60, 60 are set in advance so as to be able to capture the reference point of the plate work located at a certain distance.
The reference hole position HL of the plate workpiece W can be imaged as a position within a two-dimensional orthogonal coordinate system.

[0031] The position of the reference hole position HL of the workpiece W captured within such a two-dimensional orthogonal coordinate system is
When compared with the two-dimensional coordinate values of the reference hole position previously stored in the image processing device at the manipulator teaching stage, it is possible to determine how much the position of the plate workpiece W held by the hand 10 deviates from the taught optimal transport position. This means that it can be easily determined by calculation whether it is present or not.

Hand 1 of the plate workpiece W thus obtained
If the amount of positional deviation in the state of zero grip is captured in a two-dimensional orthogonal coordinate system and transported to the next process, it is easy to position it on the work table of the processing machine in the next process or on the mating workpiece in the assembly process. It becomes possible to place the plate work W while correcting the position. In addition, in the process described above, when correcting the pitch change due to the lateral movement of the plate work W held by the work gripping tools 28, 48, 48, the stopper member 30 on the upper rod side of the vertical movement cylinders 22, 42, 42 , 54, if the pitch change is not performed smoothly due to the friction caused by the stops, a circuit for gradually cutting off the working fluid pressure to the working fluid circuit may be added to eliminate the friction.

The hand for picking up a plate workpiece W according to the present invention has been described above according to a preferred embodiment, and it will be understood from the explanation of the above-mentioned embodiment that the present invention provides the following effects.

[0034]

According to the present invention, when the plate workpieces accumulated in a stacked state are transported to the next process by the operation of the manipulator, the plate workpieces can be reliably picked up and gripped one by one, and the gripping state can be maintained. The workpiece can be set in the optimal transport posture for the next process, and the transport posture reliably sets the orientation in the ordinate direction in three-dimensional space to a predetermined value.
It is only necessary to capture the reference position of the surface of the plate work as two-dimensional coordinate values with a camera, which simplifies the detection of the workpiece posture, and it is sufficient to find the deviation of the workpiece from the reference posture within the two-dimensional coordinate system. Transport to the next process,
When positioning and installing, it is sufficient to correct the position within a two-dimensional plane, which simplifies positioning and enables highly accurate positioning.

[0035] Furthermore, unlike the case where the camera installed in the hand is three-dimensionally imaged and captured, installation is easier, and the number of cameras can be reduced, resulting in cost reduction. . Furthermore, since the hand can capture the reference position of the plate workpiece with a camera and find the correction amount during the process of transporting it to the next process, the takt time for processing a large number of plate workpieces can be shortened. It becomes possible to improve the efficiency of the automatic conveyance process.

[Brief explanation of drawings]

FIG. 1(a) is a plan view showing the overall configuration of a hand for picking up a plate work according to the present invention. (b) is a side view showing the overall configuration of a hand for picking up a plate work according to the present invention.

FIG. 2 is a partial mechanical diagram showing a cross-sectional view of the configuration of a first workpiece gripping means operated by a vertically moving cylinder provided in the hand.

FIG. 3 is a partial mechanical diagram illustrating in cross section the structure of a second workpiece gripping means that is also laterally movable and is operated by a vertically movable cylinder provided in the same hand.

4 is a plan view of the second workpiece gripping means as seen from line (4)-(4) in FIG. 3; FIG.

FIG. 5 is an enlarged view of part G in FIG. 3 in the direction of arrows.

FIG. 6 is a fluid circuit of a vertically moving cylinder.

FIG. 7 is an explanatory diagram showing a process in which the ordinate orientation of the plate work gripped by the first and second work gripping means of the hand is set to a predetermined orientation.

FIG. 8 is a perspective view of a workpiece processed into a vehicle body chassis part as an example of a plate workpiece.

[Explanation of sign]

10...hand, 12...hand frame, 20...first work gripping means, 22...first vertical movement cylinder, 26...Universal joint, 28...Work gripping tool, 30...stopper member, 32... setter, 40...Second work gripping means, 42...Second vertical movement cylinder, 46...Universal joint, 48...Work gripping tool, 54...stopper plate, 58... Lateral movement fixing cylinder, 60...Camera.

Claims (6)

[Claims] 1. Each workpiece is picked up from a stack of plate workpieces having unevenness, gripped, and supplied to the next process with the workpiece posture fixed at least at a predetermined ordinate posture in an orthogonal three-dimensional coordinate posture. A hand for picking up plate workpieces that can be set in a posture, and includes a hand frame that can be attached to a movable body such as a work loader, and is attached to the lower end of a first vertically movable cylinder fixed to the hand frame via a universal joint. a first workpiece gripping means that is brought into contact with and grips a plate workpiece surface by the downward movement of the vertically moving cylinder; and a second workpiece gripping means that is held by the hand frame so as to be able to move horizontally by a predetermined amount. a second work gripping means that is provided at the lower end of the movable cylinder via a universal joint and that comes into contact with and grips the surface of the plate workpiece by the downward movement of the vertically movable cylinder; and the first and second workpieces. When the plate workpiece picked up and gripped by the gripping means is raised together with the hand frame from the stack of workpieces, the plate workpiece is lifted up by the natural downward movement or pressure movement of the first and second vertically moving cylinders. stopper means provided to set the ordinate orientation of the workpiece to a predetermined orientation, and when the ordinate orientation of the workpiece picked up and gripped by the first and second gripping means is set to the predetermined orientation; fixing means provided to prevent horizontal movement of the second horizontally movable vertical cylinder having the second gripping means; A plate object, characterized in that it is configured to include camera means for capturing an image of a preset reference point on the work surface of the plate object picked up and held by the workpiece gripping means and set in the predetermined posture. Hand for picking up the workpiece. [Claim 2] The pick-up hand for the plate workpiece is
The plate according to claim 1, further comprising a restraining means for restraining the lateral movement of the second vertically movable cylinder having the second work gripping means at its lower end and capable of laterally moving. A hand for picking up workpieces. 3. One of the first workpiece gripping means;
2. The hand for picking up a plate work according to claim 1, wherein the two second work gripping means are provided at three positions on the hand frame. 4. The stopper means is attached to a stopper member provided on the upwardly protruding rod of the vertically movable cylinder and a hand frame, and mechanically engages with the stopper member to stop the upwardly protruding rod of the vertically movable cylinder. 2. The hand for picking up a plate work according to claim 1, further comprising a stop setter for stopping the workpiece. 5. The fixing means is attached to the hand frame and when pressed and engaged with an arm stick protruding from the laterally movable second vertical cylinder, the fixing means locks the second vertical cylinder. a third with a stator that prevents lateral movement;
The hand for picking up a plate work according to claim 1, comprising a cylinder. 6. The second vertically movable cylinder, which is laterally movable and has the second work gripping means at its lower end, is held by a pair of cylinder holding plates that sandwich the horizontal plate member from above and below via a ball. 2. The hand for picking up a plate work according to claim 1, having the following configuration.