JP2000153489A - Compliance unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a compliance unit to compactly and smoothly actuate by providing a compliance function in a Z-axis direction perpendicular to an X-Y plane as well as in the X-Y plane. SOLUTION: In this unit, a slide member guided to move in a Z-axis direction by an inner circumference of a body 1 through a slide element 20 is engaged in the body in a cylindrical form. On the inner side of the slide member, a base plate 32 integrated with a table 31 is slidably disposed in an X-Y plane perpendicular to the Z-axis direction through a plane slide element 30.

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 and the like by a robot hand. The present invention relates to a compliance unit having a compact configuration while having a compliance function not only in a planar XY position correction function but also in a Z-axis direction perpendicular to the XY plane.

[0002]

2. Description of the Related Art Conventionally, in order to impart flexibility to an external action to a workpiece or a tool held by a robot hand or the like, or to flexibly cope with relative contact of another arbitrary member. In addition, a compliance unit is used. This compliance unit generally has a planar position correction function in the XY directions. However, with the diversification of its use, it is desired to provide a compliance function also in the Z axis direction perpendicular to the XY plane. Moreover, it is desired to realize it with a compact structure.

A compliance function is also provided in the Z-axis direction. For example, when another member is inserted into a hole of an arbitrary member, the table holding one member does not tilt, and the table holding one member does not tilt. And it is required to exhibit a compliance function in the Z-axis direction. That is, even if a force is applied to the table in a direction to incline the table, or an eccentric load is applied to a position slightly deviated from the center of the table. It is required to operate smoothly in the XY plane and the Z-axis direction so as not to lose the compliance function.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to satisfy such a demand, and its technical problem is not only in the XY plane but also in the Z axis perpendicular to the plane. It is another object of the present invention to provide a compliance unit having a compliance function in the direction.

A more specific technical object of the present invention is to provide a compliance function in the Z-axis direction,
An object of the present invention is to provide a compliance unit that realizes a compact apparatus when incorporating a cylinder that is driven in the axial direction. Another technical object of the present invention is to provide a compliance unit that operates smoothly in the XY plane and in the Z-axis direction even if there is a load point at a position deviated from the center so that the compliance function is not lost. It is in.

[0006]

A compliance unit according to the present invention for solving the above-mentioned problems is a slide unit in which a cylindrical body is guided in an axial direction by an inner periphery of the body via a slide element. A moving member is fitted, and a base plate integrated with a table is placed inside the sliding member via a plane sliding element in an XY plane orthogonal to a Z-axis direction which is a moving direction of the sliding member. It is characterized by being slidably disposed. In the compliance unit, a pneumatic cylinder whose axis is oriented in the Z-axis direction is provided integrally with the body, and a piston driven by supply and discharge of compressed air into and from the cylinder is integrated with a sliding member. it can.

Further, in the compliance unit, a slide element for guiding the axial movement of the slide member on the inner periphery of the body is provided, and a large number of steel balls are provided on a retainer between the cylindrical body and the slide member. By holding the steel plate, a large number of steel balls can be arranged on the entire periphery of the sliding member corresponding to both axial ends of the sliding member, and a base plate is provided inside the sliding member. A planar slide element that is slidable in the XY plane is configured by holding a large number of steel balls on retainers disposed on both sides of the base plate, and the base plate and the planar slide element are formed by a sliding member. It can be held between the sliding member body to be configured and the cover plate fixed thereto via a spacer.

In the compliance unit having the above structure, a sliding member whose axial movement is guided by the inner periphery of the body via a sliding element is fitted in a cylindrical body. Because the base plate integrated with the table is slidably held in the XY plane on the inside, it has a compact structure and has a compliance function not only in the XY plane but also in the Z-axis direction perpendicular to the plane. be able to. In a case where a pneumatic cylinder whose axis is oriented in the Z-axis direction is integrally provided on the body of the compliance unit and the piston can be driven by supplying and discharging compressed air into the cylinder, the piston can be similarly made compact. .

In the above compliance unit, the sliding element for guiding the sliding member in the axial direction is constituted by holding a large number of steel balls in a retainer between the cylindrical body and the sliding member. When a large number of the steel balls are arranged on the entire circumference of the sliding member in correspondence with both ends in the axial direction of the sliding member, the steel balls are arranged at both ends in the axial direction of the sliding member. Therefore, even if there is a load point at a position deviated from the center of the table, the table operates smoothly in the XY plane and in the Z-axis direction, and the compliance function is lost. Absent.

[0010]

1 to 3 show a first embodiment of a compliance unit according to the present invention.
The compliance unit according to the first embodiment includes a substantially cylindrical body 1 attached to a hand H or the like of an industrial robot. The body 1 includes a cylinder portion 2 which forms a pneumatic cylinder 6 in cooperation with a part of the hand H.
And the axial direction of the sliding member 10 housed therein (Z-axis direction)
A bolt 7 is attached to the wear-resistant guide cylinder 3 for guiding the movement.
And further, an annular end plate 4 is connected to the tip of the guide tube portion 3 with a bolt 8.

A slide element 2 fitted in the body 1
The sliding member 10, whose axial movement is guided by the inner periphery of the body 1 through the sliding member 0, has a sliding member body 11 integrally provided with a piston 12 and a sliding member with respect to the sliding member body 11. And a cover plate 14 fixed through a cover 13, which are fixed by bolts 16 and 17. Reference numerals 18 and 19 indicate pins used for positioning the sliding member body 11 and the spacer 13 and for fixing the spacer 13 and the cover plate 14 at the time of fixing.

The piston 12 integrated with the sliding member main body 11 is slidably accommodated in the cylinder portion 2 and the piston 12 is slidably accommodated outside the piston 12 (with respect to the mounting surface of the hand H on which the body 1 is mounted). The pressure chamber 22 is provided with a supply / discharge port 23 for supplying / discharging compressed air to / from the pressure chamber 22 to drive the piston 12 in the axial direction. A piston packing 12a is fitted around the piston 12. The pneumatic cylinder 6 has a supply / discharge port 23 for supplying / discharging compressed air to / from the pressure chamber 22.
It does not have any means for returning. This is the first
This is because the embodiment presupposes that the piston 12 is driven to return by an external force as necessary.

A sliding member 10, that is, a sliding member main body 11, which is guided in an axial direction by an inner periphery of the guide cylindrical portion 3 through a sliding element 20, is provided in a guide cylindrical portion 3 of the body 1. The spacer 13 and the cover plate 14 are fitted. The slide element 20 is a cylindrical retainer 25 between the guide cylinder 3 of the body 1 and the slide member 10.
A plurality of steel balls 26 are held in holes 25 a provided in the sliding member 10, and the steel balls 26 are arranged around the entire periphery of the sliding member 10 so as to correspond to the vicinity of both axial ends of the sliding member 10. It is arranged. In the retainer 25, a number of spring receiving holes 25b are formed at equal intervals at the upper and lower ends of the periphery, and return springs 28 are respectively housed in the spring receiving holes 25b, and the outer ends thereof are connected to the cylinder portion. 2 and the end plate 4, and a biasing force is applied to the retainer 25 to always keep it at the neutral position. Accordingly, the retainer 25 moves in the direction along with the movement of the sliding member 10 in the Z-axis direction, but always returns to the neutral position when the force from the sliding member 10 stops acting thereon.

A table 31 having a position correcting function in the XY plane orthogonal to the Z axis, that is, a compliance function, is held inside the sliding member 10. The table 31 includes a base plate 32 fixed and integrated with bolts 33, and a disk-shaped portion of the base plate 32 protruding around the base plate 32 via a pair of flat slide elements 30 abutting on the front and back surfaces thereof. Sliding member 1 guided in Z-axis direction movement in guide cylinder 3
In the XY plane orthogonal to the Z-axis direction, which is the moving direction of the sliding member 10, the sliding member 10 is slidably held in any direction by being fitted between the sliding member main body 11 and the cover plate 14 at the same time. It is a thing. The flat slide element 30
A large number of steel balls 3 are attached to a soft material retainer 35 forming an annular plate.
6 are held at equal intervals.

Therefore, the table 31 not only has a compliance function in the XY plane, but also slides the slide member 10 holding the table 31 on the guide cylinder 3 via the slide element 20 in the Z-axis direction as described above. Since the movement is guided, a compliance function is also provided in the Z-axis direction. The Z-axis compliance function is such that low-pressure air is appropriately introduced into the pressure chamber 22 of the piston 12 and the action force is applied to the table 3 from the outside.
1 can also be opposed. The piston 12 supplies compressed air to the pressure chamber 22 so that the table 3
1 can be driven in the Z-axis direction.

On the surface of the sliding member main body 11 on the table 31 side, several ball bases 38 having a concave conical ball receiver 39 are provided, and balls 40 held at corresponding positions on the table 31 are provided. Is pressed into the ball receiver 39 by a spring 41 disposed behind the spring to bias the table 31 so as to always maintain the table 31 at the origin position. In FIG. 2, a parallel pin 43 provided on the cover plate 14 fits into a concave groove of the end plate 4 to set an allowable rotation range of the sliding member 10 with respect to the body 1, and a parallel pin 44 provided on the body 1. Is set in the concave groove of the table 31 to set an allowable rotation range of the table 31 around the Z axis with respect to the body 1.

The compliance unit according to the first embodiment having the above-described structure includes a sliding member 10 in which the Z-axis direction movement is guided inside the cylindrical body 1 by the inner circumference of the body 1 via the sliding element 20. And a base plate 32 integrated with the table 31 is provided inside the sliding member 10.
Is slidably held in any direction in the XY plane, so that the member for providing the compliance function in the Z-axis direction has a more compact structure than the member having the compliance function in the XY plane. Can be incorporated as Also, the pneumatic cylinder 6 whose axis is oriented in the Z-axis direction is integrally provided on the body 1 of the compliance unit, and it can be similarly formed compact.

Further, in the compliance unit, the sliding element 20 for guiding the movement of the sliding member 10 in the Z-axis direction is replaced with the cylindrical body 1 and the sliding member 10.
A large number of steel balls 26 are arranged on the entire circumference of the sliding member 10 so as to correspond to both ends of the sliding member 10 in the axial direction. The sliding member 10 is provided with steel balls 26 at both ends in the axial direction.
Are arranged apart from each other, so that the sliding member 1
0 indicates that not only the sliding in the Z-axis direction is smooth, but also a directional force acting on the sliding member 10 to incline it, or
Even if a load is applied to a position shifted from the center of the table 31, the posture of the sliding member 10 is stabilized, and the table 31 smoothly operates in the XY plane and the Z-axis direction, and Is achieved.

FIG. 4 shows a second embodiment of the compliance unit according to the present invention. The compliance unit of the second embodiment has a substantially cylindrical body 51 attached to the hand of an industrial robot, as in the case of the first embodiment of FIG.
1 connects the cylinder portion 52 independently constituting the pneumatic cylinder 56 and a wear-resistant guide cylinder portion 53 for guiding the axial movement (Z-axis direction) of the sliding member 60 housed therein, An annular end plate 54 is connected to the end of the guide cylinder 53.

The sliding member 60 fitted in the body 51 to guide the axial movement is provided with a sliding member main body 61 formed separately from the piston 62 in the cylinder portion 52.
The sliding member main body 61 and the piston 62 are
The two parts are connected to each other by screws provided at the center, and the connection part is airtightly inserted into the rod-side end wall 56a of the pneumatic cylinder 56 and penetrated therethrough. Thereby, the pressure chambers 72a, 7a are provided on both sides of the piston 62 in the cylinder portion 52.
The cylinder portion 52 is provided with supply / discharge ports 73a, 73b for supplying and discharging compressed air to the pressure chambers 72a, 72b to drive and return the piston 62 in the axial direction. .

The pneumatic cylinder 56 includes a pressure chamber 72
Although it can be driven and returned by supplying and discharging compressed air to the a and 72b, other functions and operations are the same as those of the first embodiment. In addition, the configuration and operation of the second embodiment other than those described above are the same as those of the first embodiment. Therefore, in the second embodiment of FIG. 4, the same or corresponding main parts as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof will be omitted.

[0022]

As described above in detail, according to the compliance unit of the present invention, it is possible to obtain a compliance unit having a compliance function not only in the XY plane but also in the Z-axis direction perpendicular to the plane. The compliance unit with these compliance functions can be operated in the XY plane and the Z-axis direction smoothly even if there is a load point at a position deviated from the center with a compact structure. And a compliance unit that does not lose data.

[Brief description of the drawings]

FIG. 1 shows a first example of a compliance unit according to the present invention.
It is sectional drawing which shows the structure of an Example.

FIG. 2 is a sectional view at another position of the first embodiment.

FIG. 3 is a partially broken perspective view showing the configuration of the first embodiment.

FIG. 4 shows a second example of the compliance unit according to the present invention.
It is sectional drawing which shows the structure of an Example.

[Explanation of symbols]

 1,51 Body 6,56 Pneumatic cylinder 10,60 Sliding member 11,61 Sliding member body 12,62 Piston 13 Spacer 14 Cover plate 20 Slide element 25,35 Retainer 26,36 Steel ball 30 Flat slide element 31 Table 32 Base plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Susumu Takada, Inventor 4-2-2 Kinudai, Taniwara-mura, Tsukuba-gun, Ibaraki F-Term in Tsukuba Technical Center, SMC Corporation 3F060 FA11 3J101 AA02 AA32 AA43 AA52 AA53 AA62 AA72 AA73 BA34 BA35 BA44 GA32

Claims (4)

[Claims] A sliding member whose axial movement is guided by an inner periphery of the body via a sliding element is fitted in a cylindrical body, and a flat sliding element is provided inside the sliding member. A base plate integrated with the table is slidably disposed in an XY plane orthogonal to the Z-axis direction, which is the direction of movement of the sliding member, via the base unit. 2. The compliance unit according to claim 1, wherein a pneumatic cylinder having an axis oriented in the Z-axis direction is integrally provided on the body, and a piston and a slide driven by the supply and discharge of compressed air into the cylinder. A compliance unit characterized by integrating a moving member. 3. The compliance unit according to claim 1, wherein a slide element for guiding an axial movement of the slide member at an inner periphery of the body is provided between the cylindrical body and the slide member. A plurality of steel balls are provided on the entire circumference of the sliding member so as to correspond to both axial ends of the sliding member. 4. The compliance unit according to claim 1, wherein a planar slide element for slidably moving the base plate in the XY plane inside the slide member is provided on both sides of the base plate. The base plate and the planar slide element are constituted by holding a large number of steel balls in a retainer provided, and a sliding member body constituting the sliding member and a cover plate fixed thereto via a spacer. A compliance unit characterized by being held between.