JP2002172582A - Compliance unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small compliance unit as a whole having a body tiltable around one of a fist shaft and a second shaft orthogonal to the center axis of a table and mutually orthogonal and a returning mechanism for returning the tilting of the body to an original position. SOLUTION: A tilting part 20 is disposed between a main body 3 and the table 1, a hollow joint ring 21 for connecting the main body 3 to the table 1 tiltably around the second shaft is interposed between the main body 3 and the table 1, and a pressure contact part 27a for returning the table 1 to the original position is operated through a hollow 21a in the hollow joint ring 21 by driving of a cylinder mechanism 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compliance unit for realizing a flexible response to relative contact of arbitrary members such as insertion and insertion of parts in automatic assembly by an industrial robot hand. .

[0002]

2. Description of the Related Art Conventionally, a work or a tool held by a hand or the like of an industrial robot is given flexibility to an external action, or a flexible response to relative contact with another arbitrary member. In order to realize, a compliance unit is used. The compliance unit includes a body to which an arm or the like of an industrial robot is attached, and a table to be attached to a hand or the like of the industrial robot. The body has an XY perpendicular to the table with respect to the center axis of the table. With the compliance function along the plane, the body is
2. Description of the Related Art There is known an apparatus having a structure mounted on a table so as to be tiltable about one axis or two axes orthogonal to a center axis of the table and orthogonal to each other. However, this type of compliance unit usually has a return function for returning the position of the body to the table to the origin position with respect to the compliance function along the XY plane orthogonal to the center axis of the table. In the case where a return mechanism for returning to the origin is provided, the structure becomes complicated and the size becomes large, so a compact compliance unit having a return mechanism for a tilted body has been desired. In addition, when the above-described tilting body return mechanism is incorporated in the compliance unit, the size of the entire unit has recently been required to be reduced. Therefore, the unit is made as compact as possible including the return mechanism. It is considered important.

[0003]

An object of the present invention is to provide a structure in which a body is attached to a table so as to be tiltable about one or two axes perpendicular to the center axis of the table and perpendicular to each other. A compliance unit provided with a return mechanism for returning the tilt of the body with respect to the table to the home position, and which can be downsized as a whole.

[0004]

According to a compliance unit of the present invention for solving the above-mentioned problems, a body provided at one end of a table has an XY plane perpendicular to a center axis of the body with respect to the table. Compliance units with compliance functions
The body has a body main body having the compliance function, and an end member provided on the other end side of the body main body, and is provided between the body main body and the end member or the table, at right angles to a center axis of the body. And a tilting portion for adjusting the tilt of the table, the tilting portion being configured to be tiltable around two axes orthogonal to each other, wherein the tilting portion is disposed between the body main body and the end member or the table. And a hollow joint ring for connecting the end member or the table so as to be able to tilt around the two axes, and by returning a tilt of the table to the origin by driving a cylinder mechanism provided in the body body. The pressure contact member for pressing the end member or the table has a structure operating through the hollow of the joint ring. It is intended.

In the compliance unit having the above structure, a hollow joint ring for connecting the end member or the table so as to be tiltable about two axes is interposed between the body body and the end member or the table.
Through the hollow portion of the joint ring, the end member or the pressure contact member that presses the table is operated by driving the cylinder provided on the body body, so that the hollow portion of the joint ring is effectively used to save space. This makes it possible to downsize the entire compliance unit.

In the compliance unit of the present invention, the joint ring is connected to the body main body so as to be tiltable around a first axis orthogonal to the center axis of the body main body, and the end ring or the table is connected to the joint ring. Can be connected to be tiltable about a second axis orthogonal to the first axis. Further, in the present invention, a buffer mechanism in the center axis direction of the body can be provided between the body and the end member.

[0007]

1 and 2 show a first embodiment of a compliance unit according to the present invention.
The compliance unit of this embodiment includes a table 1 acting on a work or the like, and a body 2 provided at one end of the table 1 and attached to an arm or the like of an industrial robot.

The table 1 has a flow passage 1a for supplying and discharging compressed fluid at the center thereof, and a tilting portion 20 described later is provided on the outer periphery of a conduit portion 1b constituting the flow passage 1a.
The centering member 1c used for the origin return mechanism 25 is fixed. The surface of the alignment member 1c on the side facing the body main body 3 is formed so as to be parallel to an XY plane orthogonal to the axial direction of the table 1.

The body 2 has a body 3 connected to the table 1 at one end and an end member 4 connected to the other end of the body 3. The end member 4 is a portion which is substantially connected to an arm or the like of an industrial robot. The base member 5 having a connection surface 5a at an end opposite to the connection side of the body main body 3; 5 and a first cylinder mechanism 6 that is driven by fluid pressure in the axial direction of the body 2.

The first cylinder mechanism 6 serves as a buffer mechanism for the table 1. When a force in the center axis direction of the table 1 acts on the table through a hand or an arm of an industrial robot. The shock absorber and the flexible response can be realized, and the force by which the workpiece or the tool presses another arbitrary member can be adjusted.
Specifically, the first cylinder mechanism 6 includes a cylinder hole 7 formed in the base member 5, a piston member 8 that slides inside the cylinder hole 7, and an end side of the cylinder hole 7. A guide mechanism 9 extending in a columnar shape to the opening side for guiding the drive of the piston member 8 linearly in the axial direction of the body 2, and a supply mechanism for supplying and discharging compressed fluid to and from the pressure chamber 7 a in the cylinder hole 7. And an exhaust port 10.

The piston member 8 has, on one end surface side,
A rod portion 8a extending from the cylinder hole 7 is provided integrally with the piston member 8 and the rod portion 8a.
Is provided on the axis thereof so as to pass therethrough, and the shaft portion of the guide mechanism 9 is slidably inserted into the insertion hole 8b. Further, between the inner peripheral surface of the insertion hole of the piston member 8 and the outer peripheral surface of the shaft of the guide mechanism 9, a large number of steel balls 9a held on the outer peripheral surface of the shaft are provided.
Are interposed to enable smooth sliding between the guide mechanism 9 and the piston member 8. The opening end of the piston member 8 on the side derived from the cylinder hole 7 is formed in a disk shape larger in diameter than the rod portion 8a of the piston member 8, which constitutes a part of a compliance function described later. The base plate 11 extends along the XY plane orthogonal to the axial direction of the end member 4 and the insertion hole 8
It is attached so that the opening of b may be airtightly closed.

On the other hand, the body 3 has a structure for exhibiting a compliance function along an XY plane orthogonal to the center axis of the body 3. A specific configuration relating to the compliance function is as follows. The base plate 11 attached to the piston member 8 of the end member 4 and the X perpendicular to the axial direction of the body 3.
An annular holding plate 12 attached to one end of the body main body 3 along the Y plane; and an annular holding plate 12 disposed on the base plate 11 with the holding plate 12 interposed therebetween. A pair of planar slide elements 13 and 13 that slide along the upper XY plane and a base plate attached to the base end side of the rod portion 8a of the piston member 8 and the holding plate 12 and the planar slide elements 13 and 13. 11 and an annular receiving plate 14 sandwiched therebetween. Therefore, the body body 3 and the end member 4 are connected to each other through the configuration relating to the compliance function, and the compliance function works between the end member 4 and the table 1 connected to the arm or the like of the industrial robot. It will be.

The holding plate 12 is formed such that its inner peripheral edge protrudes from the peripheral edge of the concave portion 3a formed in the body 3 to the concave portion 3a side. The pair of planar slide elements 13, 13 are of the same shape in which a large number of steel balls 13b are held at equal intervals on a ring-shaped retainer 13a, and each of the retainers 13a has a steel ball 13b. It is formed in an annular shape having a diameter such that it is located on the base plate 11 near the outer peripheral end.

A holding hole 12a for holding a large-diameter ball 15 is formed in the holding plate 12 at a position corresponding to the periphery of the concave portion 3a of the body main body 3. A ball base 16 having a concave conical ball receiving surface 16a for receiving the ball 15 held in the holding hole 12a is attached to the receiving plate 14 at a position corresponding to the holding hole 12a.

Further, at a position corresponding to the holding hole 12a on the periphery of the concave portion 3a of the body main body 3, a second cylinder mechanism 17 for pressing the ball 15 against the ball receiving surface 16a of the ball base 16 by its drive is provided. ing. The second cylinder mechanism 17 includes a supply / discharge port 17
By supplying a compressed fluid through c and driving the piston member 17a, the ball 15 is pressed by the piston member 17a and press-fitted to the ball receiving surface 16a, and the end member 4 shifted from the origin position by the compliance function is removed. The end member 4 can be fixed to the origin position while returning to the origin position. The piston member 17a is also pressed by the elastic force of the spring 17b. In FIG. 1, the ball base 16 and the second piston mechanism 17 are
Although it appears only at a portion, it is actually provided at a plurality of portions for stable operation.

The receiving plate 14 has a body 3
An insertion hole 14a into which a pin 18 that extends through the holding plate 12 and extends toward the receiving plate 14 is inserted from a position other than the second piston in the concave portion 3a. The insertion hole 14a has a diameter larger than the diameter of the pin 18, and the insertion hole 14a and the pin 18 allow the body body 3 with respect to the end member 4 in the compliance function.
Can be limited.

The table 1 and the body 3 are connected to each other via a tilting portion 20 which is configured to be tiltable about two axes orthogonal to the center axis of the table 1 and orthogonal to each other. The tilting portion 20 tilts the table 1 with respect to the center axis of the body 2 and thus the end member 4 (substantially, the mounting surface 5a of the base member 5 on the end member 4) connected to the arm of the industrial robot.
And a joint ring 21 for connecting the body main body 3 and the table 1 so as to be tiltable about two axes, and returning the inclination of the body 2 with respect to the center axis of the table 1 to the origin. And an origin return mechanism 25 for performing the operation.

As shown in FIG. 2, the joint ring 21 has a hollow shape formed in a frame shape having a substantially rectangular cross section as a whole so as to be accommodated in the concave groove 3b at one end of the body main body 3. A part of each of the table 1 and the home position return mechanism 25, and almost the entire alignment member 1c of the table 1 are accommodated in the hollow portion 21a. The joint ring 21 is provided at a central position between the opposite sides 21b, 21b along the groove wall 3c of the concave groove 3b of the body main body 3, and a pair of first shafts 22, 22 is provided.
As a result, the body body 3 is connected to be tiltable, while the opposite side portions 21c, 21c between the pair of groove walls 3c, 3c are provided.
The centering member 1c fixed to the table 1 and the center position of the second shaft 23, 2
3, the joint ring 21 is connected to the table 1 so as to be tiltable. The first shaft 22 and the second shaft 23 are mounted so that their respective axes are orthogonal to each other. The tilting direction of the joint ring 21 and the body main body 3 and the tilting of the table 1 and the joint ring 21 The directions are orthogonal to each other, whereby the table 1 and the body 3 are connected to be tiltable about two axes.

The home position return mechanism 25 passes through the hollow portion 21a of the joint ring by driving a fluid pressure driven third cylinder mechanism 26 provided on the body 3 and a piston member 27 of the third cylinder mechanism 26. A pressure contact portion 27a integrally formed on the distal end side of the piston member 27, which moves and operates. Third cylinder mechanism 2
A guide member 29 is fitted into a cylinder hole 28 formed in the groove bottom of the concave groove 3b of the body main body 3, and guides the piston member 27 in the driving direction.
9 and the piston member 27, and smoothly drive the piston member 27 along the guide member 29.
A slide mechanism 30 having a structure in which a large number of steel balls 30a are held by a retainer 30b, a spring 31 for pressing the piston member 27, and a supply and discharge port for supplying and discharging compressed fluid to and from the pressure chamber 28a of the cylinder hole 28. 3
And 2.

The third cylinder mechanism 26 supplies compressed fluid through a supply / discharge port 32 to a pressure chamber 28 a of a cylinder hole 28.
The piston member 27 is driven by being supplied into the inside,
The drive causes the press-contact portion 27a to operate to press the alignment member 1c, whereby the inclination of the body 2 with respect to the table 1 can be returned to its origin and fixed.

At the center of the piston member 27, a flow passage 1e from a port 1d (shown by a broken line in FIG. 1) provided in the body 3 and the flow passage 1a of the table 1 are airtightly connected. The pipe 33 to be fitted is hermetically inserted. The pipe 33 can maintain airtightness even when the body 3 tilts with respect to the table 1. The spring 31 is disposed on the outer periphery of the pipe 33 at the center of the piston member 27. In FIG. 2, reference numeral 36 denotes a pipe 33 and a flow passage 1 of the table 1.
a sealing member for sealing the gap between the first and second members.

In the compliance unit having the above structure, a hollow joint ring 21 for connecting the body 3 and the table 1 so as to be tiltable about two axes is interposed between the body 3 and the table 1. The joint ring 21 is provided with a configuration in which the pressing portion 27a for pressing the alignment member 1c of the table 1 is operated by driving the third cylinder 26 provided in the body 1 through the hollow portion 21a of the joint ring 21. Space can be achieved by effectively utilizing the hollow portion 21a of
This makes it possible to reduce the size of the entire compliance unit.

Further, when a tool or a work attached to the table 1 comes into contact with another arbitrary member, the body 2 tilts with respect to the table 1 depending on the contact angle of the tool or the like. At that time, due to the tilting, a slight error occurs in a direction perpendicular to the axial direction of the table at a contact position of the tool or the like with an arbitrary member, and it is conceivable that damage is caused by partial contact of the tool or the like. The error is compensated for by the compliance function, and the impact of the contact and the like is absorbed by the action of the first piston mechanism. More effective flexibility can be imparted to a natural contact.

FIGS. 3 and 4 show a second embodiment of the compliance unit according to the present invention. The compliance unit according to this embodiment is different from the first embodiment in that the tilt unit 2 is used.
0 is provided between the body 3 of the body 2 and the table 1, whereas the tilting portion 80 is provided between the body 53 and the end member 54 of the body 52.

The compliance unit includes a table 51 and a body 52 attached to one end of the table 51. The body 52 includes a body 53 connected to the table 51 and an industrial robot. And an end member 54 attached to the arm or the like.

The end member 54 is a base member 5 having a connecting surface 55a connected to an arm or the like of an industrial robot.
5, a pair of upright walls 56, 56 provided at both ends of the base member 55 for connection to the body main body 53, and a trapezoidal projection at the center of the base member 55 between the pair of upright walls 56, 56. And an alignment member 60 provided.

The table 51 and the body 53 are
The entire body 52 is connected to each other via a configuration for exhibiting a compliance function along an XY plane orthogonal to the center axis. That is, the configuration relating to the compliance function includes a disc-shaped base plate 61 attached to one end side of the body main body 53 along an XY plane orthogonal to the center axis of the body 52,
1 and sandwich the table 51 with the base plate 6.
1, a pair of planar slide elements 63, 63 that slide along the XY plane, and an annular holding plate 62 disposed so as to sandwich the base plate 61 and the pair of planar slide mechanisms 63, 63 together with the table 51. And a spacer 64 that connects the holding plate 62 and the table 51 to each other while maintaining a constant space therebetween. Further, a pin 78 extending from the body main body 53 is inserted into a portion of the holding plate 62 facing the body main body 53, and an insertion groove 62a used to limit the movement distance of the body main body 53 with respect to the table 51 in the compliance function. Is provided. The configuration of the flat slide mechanism 63 is substantially the same as that of the first embodiment. Therefore, the table 51 and the body 53 are connected to each other through the configuration relating to the compliance function, and the compliance function works between the table 51 and the body 53.

The body 52, which is displaced by the compliance function, and the table 5
A first cylinder mechanism 67 is provided for returning the position 1 to the origin position and immovably fixing the position at the origin position. The first cylinder mechanism 67 includes a cylinder hole 68 provided on one end side of the body main body 53, a piston member 69 slidably inserted into the cylinder hole 68,
A supply / discharge port 70 for supplying / discharging compressed fluid to / from the pressure chamber 68a of the cylinder hole 68;
8a, and a spring 71 provided inside the cylinder member 68.
9 is accommodated in the cylinder hole 68, and the base plate 61 having the configuration related to the compliance mechanism is attached so as to close the opening. The first cylinder mechanism 67
Is connected to the pressure chamber 6 of the cylinder hole 68 through the supply / discharge port 70.
The piston member 69 is driven by supplying a compressed fluid to 8a, and the piston member 69 presses a ball 65 to be described later and press-fits the ball 65 to the ball receiving surface 66a of the ball base 66.

In the base plate 61, holding holes 61a for holding a large-diameter ball 65 are formed at a plurality of positions where the base plate 61 interferes with the piston member 69 of the first cylinder mechanism 67. At the position corresponding to the holding hole 61a on the table 51, the above-mentioned ball base 66 having a concave conical ball receiving surface 66a for receiving the ball 65 held in the holding hole 61a is provided.

The body 53 and the end member 54 of the body 52 are connected to each other via a tilting portion 80 that is tiltable about two axes perpendicular to the center axis of the body 53 and perpendicular to each other. I have. This tilting part 80
Is a joint ring 81 for adjusting the inclination of the table 51 and the end member 54, and for connecting the body main body 53 and the end member 54 to be tiltable about two axes.
And a hydraulically driven second cylinder mechanism 86 provided in the body 53 to return the end member 54 to the original position.

As shown in FIG. 4, the joint ring 81 has a substantially annular shape having a hollow portion 81a at the center, and includes the body body 53 and a concave groove provided at one end of the body body 53. At a position facing the pair of groove walls 57a, 57a, the pair of first shafts 82, 82 are connected to each other so as to be tiltable in two directions with respect to the body main body 53. Groove walls 57a, 5
The end member 5 disposed by being rotated by 90 degrees with respect to 7a.
4 at a position facing the pair of upright walls 56, 56, different from the first shaft 82 by a pair of second shafts 83, 83.
Are mutually tilted so as to be tiltable in two directions. The first shaft 8
Similarly to the first embodiment, the second shaft 83 and the second shaft 83 are attached such that their respective axes are orthogonal to each other, and the tilting direction of the joint ring 81 with respect to the body main body 53 and the end with respect to the joint ring 81. The tilt direction of the member 54 is configured to be orthogonal to each other. Thereby, the end member 54 and the body main body 53 are connected to be tiltable about two axes.

In this embodiment, the groove wall 57a of the body 53 and the upright wall 56 of the end member 54 have
Bearings 58 and 59 for rotatably mounting the first shaft 82 or the second shaft 83 are provided. The first shaft 82 and the second shaft 83 are rotatable with respect to the groove wall 57a and the vertical wall 56. , But on the other hand,
The shaft 82 and the second shaft 83 are fixed in position with respect to the joint ring 81.

Most of the second cylinder mechanism 86 projects at the center of the groove bottom of the concave groove 57 of the body main body 53,
Further, the protruding portion is disposed such that the tip end side thereof is inserted into the hollow portion 81a of the joint ring 81, and is slidable in the cylinder hole 88 provided in the body main body 53 and the cylinder hole 88. A pressure contact member 87 also serving as a piston of the cylinder mechanism, a spring 89 for pressing the pressure contact member 87, and a supply / discharge port 90 for supplying / discharging a compressed fluid to / from the pressure chamber 88a of the cylinder hole 88. Have.

The second cylinder mechanism 86 sends the compressed fluid through the supply / discharge port 90 to the pressure chamber 88 a of the cylinder hole 88.
The pressure contact member 87 which doubles as a piston by being supplied to the inside
Is driven and operated through the hollow portion 81a of the joint ring 81.
Is pressed against the centering member 60 of the end member 54 so that the inclination of the end member 54 with respect to the body main body 53 can be returned to its origin and fixed.

The compliance unit having the above configuration can basically obtain the same effects as those of the first embodiment. However, compared with the first embodiment, the cylinder mechanism (the first embodiment) used for buffering is used. Since the first cylinder mechanism 6) is not provided, the configuration is simple, and the size can be further reduced.

[0036]

As described in detail above, according to the compliance unit of the present invention, the end member or the table is connected between the body body and the end member or the table so as to be tiltable about two axes. Since there is provided a configuration in which a hollow joint ring is interposed and a press-contact member that presses the end member or the table by pressing a cylinder provided in the body body through the hollow portion of the joint ring, the hollow portion of the joint ring is provided. Can be omitted, thereby making it possible to downsize the entire compliance unit.

[Brief description of the drawings]

FIG. 1 shows a first example of a compliance unit according to the present invention.
It is a vertical front view which shows an Example.

FIG. 2 is a cross-sectional plan view of the same.

FIG. 3 shows a second example of the compliance unit according to the present invention.
It is a vertical front view which shows an Example.

FIG. 4 is an exploded perspective view of the same.

[Explanation of symbols]

 Reference Signs List 1,51 Table 2,52 Body 3,53 Body body 4,54 End member 20,80 Tilting part 21,81 Joint ring 27a Pressure contact part 87 Pressure contact member 22,82 First shaft 23,83 Second shaft

Claims (3)

[Claims] 1. A body provided at one end of a table,
X perpendicular to the center axis of the body relative to the table
A compliance unit having a compliance function along a Y plane, wherein the body has a body body having the compliance function, and an end member provided at the other end of the body body. Alternatively, a tilting portion for adjusting the tilt of the table is provided between the table and the table, the tilting portion being configured to be tiltable around two axes orthogonal to the center axis of the body and orthogonal to each other. A hollow joint ring for connecting the body body and the end member or table to be tiltable around the two axes is interposed between the cylinder body and the end member or the table. Pressing part that presses the end member or the table to return the table tilt to the origin by driving Compliance unit but has a configuration which operates through the hollow of the joint ring, and characterized. 2. The compliance unit according to claim 1, wherein the joint ring is connected to the body main body so as to be tiltable around a first axis orthogonal to a center axis of the body main body, and the end member or the table is connected to the joint ring. And a joint ring that is tiltably connected around a second axis orthogonal to the first axis. 3. The compliance unit according to claim 1, further comprising a buffer mechanism between the body and the end member in a direction of a center axis of the body.