JPS62140736A - Floating hand - Google Patents

Abstract

PURPOSE:To have sure gripping of each work even though there is dislocation between the wrist of a robot and the work by supporting No.1 moving table on a base, No.2 moving table on said No.1 table, and by installing a pair of gripping pawls on the No.2 moving table. CONSTITUTION:Inclined surfaces 52a of a locating member 52, which are formed in a pair and face each other, contact the outside surface of a projected guide 12. Thereby No.2 moving table is moved in the Y direction against the force applied by No.2 air cylinder 37 for a distance corresponding to dislocation between the wrist 15 of robot and a work W. then a hand H moves in the X direction so that the contact surface 52b of the locating member comes in contact with one of the sides Wb of the work W. Then the hand H is moved in the Z direction by operating the robot, and gripping pawls 45 are set in gripping holes Wa in two works on the left of those W which are placed on the work supporting surface 11. Then the hand H is moved in the Z direction as apart from the work supporting surface 11 to allow taking-out of the work W.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is attached to the wrist of an industrial robot, and grips a workpiece placed at a predetermined position on a support surface such as a pallet. This invention relates to a robot hand used for repositioning the robot in a predetermined position.

[Prior art]

This type of robot hand is designed to be able to grip a workpiece even if there is some error in the positioning of the workpiece relative to the pallet or the positioning of the pallet relative to the robot, or even if the teaching of the gripping position to the robot is somewhat rough. , some have a floating mechanism and a tapered portion at the tip of the gripping claw. According to such a floating hand, even if there is some misalignment between the wrist of the robot and the workpiece, the gripping claws will move slightly due to the movement of the floating hand toward the workpiece and the guiding action of the tapered part. is inserted into the gripping part of the workpiece, and the workpiece can be gripped.

[Problem that the invention seeks to solve]

However, in such conventional technology, the guiding range by the tapered part at the tip of the gripping claw is limited to a relatively small range, so the amount of floating is also limited, and the positional deviation between the robot's wrist and the workpiece is large. In this case, the tips of the tapered portions of the gripping claws come into contact with a portion of the workpiece other than the gripping portions, and are prevented from approaching the workpiece, making it impossible to grip the workpiece.

The present invention solves the above problem by providing a guide mechanism between the gripping claws and the workpiece.

[Means for solving problems]

For this purpose, the floating hand according to the present invention is used by being attached to the wrist portion 15 of the robot, as illustrated in the embodiment of the attached drawings, and is used to hold the workpiece W placed at a predetermined position on the workpiece support surface 11. In the floating hand for gripping, a base 30 attached to the wrist portion 15;
a first movable table 35 supported by the base 30 so as to be movable only in a first direction X parallel to the workpiece support surface 11;
The first movable table 35 is movable only in a second direction Y that is parallel to the workpiece support surface 11 and orthogonal to the first direction X.
a second movable base 40 supported by the second movable base 40; at least a pair of gripping claws 45, 45 attached to the second movable base and extending parallel to each other and approaching and separating from each other; It is supported by the second movable base 40 so as to be movable only in the third direction Z, and elastically biased toward the workpiece support surface 11, and in either the first or second direction X or Y. A pair of inclined surfaces 52a, 52a facing each other in the direction X.

a positioning member 52 having an abutment surface 52b orthogonal to the other side of Y; a first positioning device 32 that preliminarily positions the first movable base 35 with respect to the base 30;
The present invention is characterized in that it includes a second positioning device 37 that preliminarily positions the movable base 40 with respect to the first movable base 35.

[Effect]

The floating hand is connected to the first and second positioning devices 32
．． 37, approach the work part halfway to the support surface 11 from the third direction Z,
First, a pair of inclined surfaces 52a, 52 of the positioning member 52 are attached to the outer surface 12a of the convex guide 12 fixed to the workpiece support surface 11.
The gripping portion W of the workpiece W in the direction Y or X when a is in contact with the
The gripping claws 45, 45 are positioned with respect to a and Wa. Next, the floating hand moves in the direction X or Y perpendicular to the above, and the contact surface 52b of the positioning member 52 contacts the workpiece W or the protrusion of the convex guide 12, and moves in the perpendicular direction X.
Alternatively, the gripping claws 45, 45 are positioned with respect to the gripping portions Wa, Wa of the workpiece W in Y. As a result, the gripping portion W of the work W in both the first and second directions X and Y
Since the gripping claws 45.4 are positioned relative to a and Wa, if the floating hand is moved in the third direction Z again to approach the workpiece support surface 11, the gripping claws 45.45
is inserted into the gripping portion Wa of the workpiece W. In this state, the pair of gripping claws 45, 45 are brought close together to grip the workpiece W, and the floating hand is moved by the robot to place it in another predetermined position.

〔Effect of the invention〕

As described above, according to the present invention, prior to insertion of the gripping claw into the gripping portion of the workpiece, the pair of inclined surfaces and the contact surface of the positioning member abut against the member on the workpiece supporting surface side, and the gripping portion of the workpiece is Since the gripping claws of the floating hand are positioned relative to the workpiece, the gripping claws can be inserted into the gripping part of the workpiece even if the amount of floating is increased regardless of the size and shape of the gripping claws. Even if the positional deviation between the wrist portion and the workpiece becomes large, the workpiece can be reliably gripped by the gripping claws of the floating hand. Further, since preliminary positioning is performed by the first and second positioning devices, the gripping claws will not move arbitrarily and the operation will not become unstable even though the amount of floating is increased.

〔Example〕

Embodiments will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the main support members of the floating hand H are support frames 20. Base 30. First movable base 35. It is composed of a second movable base 40 and a grip main body 41.

The floating hand H is attached to the wrist part 15 of the industrial articulated robot via the support frame 20, and the gripping body 41 has a gripper for gripping the workpiece W placed on the horizontal workpiece support surface 11 of the pallet 10. A positioning member 52 for positioning the gripping claws 45 to 45 with respect to the claws 45 to 45 and the workpiece W is provided.

As shown in FIGS. 1 and 2, the support frame 20 fixed to the mounting flange 15a of the wrist portion 15 holds a horizontal workpiece when the gripping claws 45 to 45 grip the workpiece W on the workpiece support surface ll. A pair of mutually parallel support shafts 21.21 extending orthogonally to the support surface 11 are fixed.

A base 30 is movably guided and supported on the support shafts 21, 21, urged toward the workpiece support surface 11 by springs 22, 22, and stopped when it comes into contact with a washer 25 fixed to the tip of each support shaft 21. are doing. A safety proximity switch 24 is provided on the support frame 20 via a support plate 23, and a dog 33 for operating the proximity switch 24 is fixed to the base 30.

In the state shown in FIGS. 1 and 2, the base 30 has a pair of mutually parallel grooves extending in a first direction parallel to the workpiece support surface 11 (left-right direction in FIG. 1, hereinafter simply referred to as the X direction). A first pilot bar 31.31 is fixed, and the first movable base 35 is guided and supported by the first pilot bar 31.31 so that it can only move in parallel in the X direction. 1st
As shown in the figure, a first air cylinder 32, which is a first positioning device, is provided at the left end of the base 30, and when the first air cylinder 32 is activated, a mouth 32a protrudes, and its tip becomes the first positioning device. The first movable base 35 is preliminarily positioned at the rightmost position by lightly abutting the left end of the movable base 35. Similarly to the above, the first movable table 35 has a pair of mutually parallel second pie openings extending in a second direction (hereinafter simply referred to as the Y direction) parallel to the workpiece support surface 11 and orthogonal to the first viroft bar 31. Soto hardware 36, 36 is fixed, and this second
The second movable base 40 is guided and supported by pilot bars 36 and 36 so that it can only move in parallel in the Y direction. As shown in FIG. 2, a pair of second air cylinders 37.37, which are second positioning devices, are provided at both ends of the first movable base 35, and these two brush 2 air cylinders 37.37 operate simultaneously to 37a.

37a protrudes, and its tips lightly contact both ends of the second movable base 40 to preliminarily position the second movable base at an intermediate position of its movement range.

As shown in FIGS. 1 and 2, each pair of guide bars 42 to 42 that protrude in both directions parallel to the second pilot bar 36 are fixed to the grip main body 41 fixed to the lower side of the second movable table 40. The guide bars 42 to 42 allow the grip main body 41 to be
A pair of reciprocating members 43, 43 facing each other with the two members in between are guided and supported so as to be able to move only in parallel in the Y direction. A pair of pawl attachment bodies 44.44 are pivotally supported to each of the advancing and retracting members 43°43 through support pins 46.46 so as to be able to rotate by a certain angle.
In the state shown in FIGS. 1 and 2, the workpiece support surface II
Two rod-shaped gripping claws 45 to 45 (see FIG. 4, 1) each extending in a third direction (hereinafter simply referred to as the Z direction) perpendicular to the Z direction are fixed.

Each advancing/retracting member 43, 43 is given an interlocking advancing/retracting movement in the direction of approaching and separating from each other by a grip cylinder 49 and a link device W (not shown) built in the grip main body 41,
This movement causes the two pairs of gripping claws 45 to 45 to move the workpieces W and W.
It is designed to hold. Since the support bins 46, 46 are parallel to the gripping claws 45, even if there is an error in each part of the robot hand H and the workpiece W, the gripping force generated in each of the gripping claws 45 to 45 will be equal.

As shown in FIGS. 1 and 3, a guide block 41a fixed to an example of the grip main body 41 (on the right side in FIG. 1) has a pair of parallel sliding rotors I"50.5 extending in the Z direction.
0, the positioning member 52 is guided and supported so that it can only move in parallel in the Z direction. The positioning member 52 is formed by bending a plate material into an inverted shape as shown in FIG. 1, and its upper edge is fixed to the lower end of the sliding rod 50. It is biased toward the workpiece support surface 11 by springs 51.51.

A portion of the positioning member 52 extending toward the workpiece support surface 11 is provided with a pair of inclined surfaces 52a, 52a facing each other in the Y direction as shown in FIG. Orthogonal contact surfaces 52b are formed. Slanted surface 52a.

52a and the contact surface 52b contact the outer circumferential surface 12a of the convex guide 12 formed and placed on the workpiece support surface 11 and the side surface of the workpiece W, and as described later, the second movable table 40 and The holding member is moved in the X and Y directions to position each of the gripping claws 45 to 45 with respect to each of the gripping holes Wa-Wa of the workpieces W and W.

As shown in FIG. 2, a work holding rod 56 is guided and supported by a guide bracket 55 fixed to the lower side of the gripping body 41 so as to be movable in the Z direction, and a spring 57 interposed between the guide bracket 55 and the guide bracket 55 is urged toward the workpiece support surface 11 by.

A dog 58 having one end fixed to the upper end of the work holding rod 56 extends horizontally as shown in FIG.
Proximity switch 4 for checking the workpiece provided on the movable table 40
It is located near the tip of 8. If the gripping claws 45 to 45 are not inserted into the gripping holes W a - W a of the workpieces W, the workpiece holding rod 56 is at the position indicated by the two-dot chain line B in FIG. 2, and the dog 58 is at the position shown in FIG. It is located at the position of the two-dot chain line C. In this state, the upper end 58a of the dog 58 is away from the tip of the proximity switch 48, and the proximity switch is inactive for four days. As shown in FIGS. 1 and 2, when the gripping claws 45 to 45 are inserted into the gripping holes W a - W a of the workpieces W and W, the workpiece holding rod 56 and the dog 58
moves upward against the spring 57 as shown by the solid line, and the upper end 58a of the dog 58 approaches the tip of the proximity switch 48 to actuate the proximity switch 48.

As shown in FIGS. 1 and 3, a guide block 60 fixed to the other side (right side in FIG. 1) of the lower surface of the grip main body 41 has a guide block 60 that holds the next workpiece (the third workpiece from the left in FIG. 1) W. A pair of plungers 61, 61 that press down are guided and supported in the Z direction, and are biased toward the workpiece support surface 11 by springs 62, 62. The plunger 61.61 has the gripping claws 45 to 45 in the workpiece W, the gripping hole W a -
When the gripping claws 45 to 45 are not inserted into the gripping hole Wa −
When inserted into W a, the tips 61a, 61a abut against the upper surface of the next workpiece W, move upward against the springs 62 and 62, and reach the position shown by the solid line, and the next workpiece W is held by the spring. 62. Press by 62. This prevents the next workpiece W from rising above the workpiece support surface 11 when the workpieces W, W gripped by the gripping claws 45 to 45 are pulled out upward.

Next, the operation of this embodiment will be explained.

The floating hand I is separated from the workpiece W, and the gripping claws 45 to 45 are in the gripping holes Wa-Wa of the workpieces W and W.
In the uninserted state, the positioning member 52. Work holding rod 56. Dog 58 and plunger 61.
61 correspond to the two-dot chain lines A, B, and B in FIG. 1 and FIG. 2, respectively.
It is located at C and D.

Further, normally, the first and second air cylinders 32, 37 are operated, and the first and second movable bases 35, 40 are preliminarily positioned at the aforementioned predetermined positions.

As shown in FIGS. 1 and 4, the plurality of workpieces W are supported in a row such that their negative side surfaces wb abut against the convex guides 12 fixed on the workpiece support surface 11.

Due to the operation of the robot, the floating hand H first moves
In the Y direction, the gripping claws 45 basically coincide with the workpiece W gripping claws Wa, and in the X direction, the abutment surface 52b of the positioning member 52 is somewhat separated from one side wb of the workpiece W (slightly to the left in FIG. The positioning member 52 approaches the work supporting surface 11 from the Z direction toward a position (separated from the position), and a pair of opposing inclined surfaces 52a, 52a of the positioning member 52 abut against the outer circumferential surface 12a of the convex guide 12, as shown in FIG. This results in
The second movable base 40 and the part supported by it resist the biasing force of the second air cylinder 37, 37 to move the robot's wrist 1
5 and the workpiece W in the Y direction by the amount of positional deviation, and
The gripping claws 45 to 45 and the gripping hole W a -W in the direction
The position of a is determined. In this state, the gripping claw 4
The tips of the plungers 5 to 45 and the plungers 61 and 61 are all located above the upper surface Wc of the workpiece W.

Next, the floating hand H is activated by the robot.
The contact surface 52b of the positioning member 52 is one side w of the workpiece W.
Move in the X direction so as to contact b. This amount of movement is
The contact surface 52b is set extra so that it always contacts one side wb, and this contact positions the gripping claws 45 to 45 and the gripping holes W a - W a in the X direction, and thereafter the first The movable base 35 and the portion supported by it move relative to the wrist portion 15 in the X direction against the biasing force of the air cylinder 32.

As a result, the gripping claws 45 to 45 and the gripping holes Wa to Wa are positioned in the X and Y directions, so if the floating hand I4 is moved in the Z direction again by the operation of the robot, the gripping claws 45 to 45 are As shown in FIGS. 1 and 4, a plurality of workpieces W- placed on the workpiece support surface ll
It is inserted into the grip holes W a -W a of the two left ones of W. At the same time, the work holding rod 56 moves against the spring 57, and the proximity switch 48 is operated via the dog 58, thereby confirming the presence of the works W, W. Next, the gripping cylinder 49 is operated to move the advancing/retracting member 4
3. 43 are brought close to each other, the two workpieces W and W on the left are gripped by the gripping claws 45 to 45, and the floating hand H is moved in the Z direction away from the workpiece support surface 11 by the operation of the robot. Take out the works W and W and move them to other predetermined positions.

In the above operation, it is also possible to perform the operation by interchanging the movements in the X direction and the Y direction. However, in the case of the above-mentioned operation, since the inclined surfaces 52a, 52a of the positioning member 52 move in the X direction while in contact with the outer peripheral surface 12a of the convex guide 12, the inclined surfaces 52a, 52a and the outer peripheral surface 12a contact each other. is preferable because it is more reliable.

In addition, some inconvenience occurs in the above operation, and the positioning of the gripping claws 45 to 45 and the gripping hole W a = W a is not performed, and the tips of the gripping claws 45 to 45 are attached to the workpiece W due to the movement of the floating hand H in the Z direction. , the base 30 moves along the support shaft 21.21 against the spring 22.22, and the tongs 33 actuate the safety proximity switch 24 to stop the operation of the robot. let

In the above embodiment, the contact surface 52b of the positioning member 52
is brought into contact with one side wb of the workpiece W to perform positioning in the X direction. However, as shown in FIG. 5, the convex guide 12A fixed on the workpiece support surface 11 is provided with a protrusion 12b parallel to one side surface wb of the workpiece W, and the contact surface 52a of the positioning member 52A is brought into contact with the side surface 12C. It is also possible to perform positioning in the X direction.

Further, in the above embodiment, the gripping claws 45 to 45 are supported by the reciprocating member 43.43 via the floating mechanism consisting of the claw attachment body 44.44 and the support pins 46, 46, and the two workpieces W, W is gripped at the same time, but instead of such a floating mechanism, the gripping claws 45 to 45 are moved back and forth via leaf springs that support them so that they can move in parallel.
．． 43, it is possible to similarly grip the two works W, W. Alternatively, the gripping claw 45 can be moved
3, and the work W can be gripped one by one at two points, or the above-mentioned floating mechanism can be used when gripping the work W at four points.

[Brief explanation of drawings]

Figures 1 to 4 show an embodiment of a floating hand according to the present invention, with Figure 1 being a side view of the whole, and Figure 2 being a partially broken whole with the positioning member and plunger for holding the next workpiece omitted. A front view, FIG. 3 is a partial front view mainly showing the positioning member and the next work holding plunger, and FIG.
FIG. 5 is a sectional view taken along the line IV-IV in the figure, and a partial side view of the vicinity of the positioning member of another embodiment. Explanation of symbols 11...Work support surface, 15...Wrist part of robot, 30...Base, 32...First positioning device (first air cylinder), 35...First movable base, 37...
Second positioning device (second air cylinder), 40... second movable base, 45-45... gripping claw, 52... positioning member, 52a. 52a...(around slope, 52b...contact surface, X...
First direction, Y... second direction, Z... third direction.

Claims (1)

[Claims] A floating hand that is attached to the wrist of a robot and used to grasp a workpiece placed at a predetermined position on a workpiece support surface includes a base attached to the wrist and a first hand parallel to the workpiece support surface. a first movable table supported by the base so as to be movable only in a direction; and a first movable table supported by the first movable table movably only in a second direction parallel to the workpiece support surface and orthogonal to the first direction. a second movable base that is attached to the second movable base, at least a pair of gripping claws that are attached to the second movable base and extend substantially parallel to each other and move toward and away from each other; a pair of sloped surfaces that are supported by the second movable table and elastically biased toward the workpiece support surface and that face each other in either one of the first and second directions; a positioning member having an abutment surface orthogonal to the other direction; a first positioning device that preliminarily positions the first movable base with respect to the base; and a first positioning device that preliminarily positions the second movable base with respect to the first movable base. A floating hand characterized by comprising a second positioning device for positioning the hand.