JPS59156697A - Linear unit of prefabricated robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an assembly robot glue near unit whose purpose is particularly precise fitting work.

Conventional configurations and their problems Conventionally, various types of assembly robots, including Cartesian coordinate robots, have been used. However, for the precision fitting work of numbers 71 to 77, the robot's positioning accuracy alone is insufficient! The reality is that IL cannot be obtained. So generally,
A compliance hand such as an RCC is attached between the robot's boot 11 and the chuck to perform the fitting work. On the other hand, recently, a horizontally articulated robot commonly referred to as SCARA robot I has been used for precision assembly.
It started to attract attention.

As shown in FIG. 1, this robot has a base 1 attached with a first arm 3 that is rotatably supported around a first rotation Qll2. A second arm 5 is attached which is rotatably supported around a second rotating shaft 4 parallel to the shaft 2.

A tool holding shaft 5a that can be slid up and down is provided at the tip of the second arm 5, and the tip of the tool holding shaft 5a has, for example,
An electric screwdriver (not shown) or the like is attached.

With such a structure, high rigidity is provided in the vertical direction, while relatively large movements in the left-right, front-back, and front-back directions are possible even with a slight external force. In other words, it is said that selectivity can be provided in the direction of compliance.

However, when actually performing fitting operations, etc., the compliance characteristics are often not exhibited as expected. One reason for this is that the direction of compliance changes depending on the working position. For example, in a position where the second arm is fully extended relative to the first arm, the compliance in the front-back direction with respect to the base is becomes smaller,
The direction of compliance that the work requires may not match.

Another cause is the backlash of the joints in order to improve the positional accuracy of each joint.

It is necessary to minimize elastic deformation, etc., but doing so will result in the loss of flexibility in the front, back, left and right directions.

Furthermore, depending on the working position, the reaction force exerted on the second arm and the tip of the tool may be affected by the first. The first arm 3 is twisted due to the torsional moment about the axis perpendicular to the second rotation axis, and the tip of the tool is no longer held vertically. On the other hand, if the first arm 3 is made to have a highly rigid structure so as not to be twisted, the frictional load and inertia load on the rotating part will increase, and the flexibility in the front, rear, left and right directions will eventually be lost.

Therefore, it is useful in all working ranges, especially in precision fitting operations. The selective compliance characteristics are not fully exhibited.

Purpose of the Invention In view of the two drawbacks, the present invention provides a robot that can be attached to the tip of a Cartesian coordinate robot, a horizontally articulated robot, etc., and exhibits high rigidity in the working direction and sufficient compliance characteristics in a direction perpendicular to the working direction. The present invention provides a linear unit of an assembly robot suitable for precision fitting work.The present invention comprises a plurality of guide shafts parallel to each other, a plurality of plates penetrating the guide shafts, and at least a screw provided parallel to the guide shaft 5.S. so that the one or more plates can move relative to each other; and a screw provided in parallel to the guide shaft 5, S, so that the one or more plates can move relative to each other; Embodiment Description of an Embodiment Below, an embodiment of the present invention will be described. This will be explained with reference to the drawings. FIG. 2 is a diagram showing the overall configuration when the linear unit of the assembly robot according to the embodiment of the present invention is attached to the distal end of a horizontal articulated robot. Figure 3 is the second
It is a detailed view of the tip part of the figure. , a 6-piece base, a column 7 is attached vertically to the base 6, and a movable base 8 is attached to the column 7 so that it can be fixed to any desired height.
is installed. An arm unit A is fixed to this movable base 8. In the arm unit A, a bearing unit 9 is attached to the movable base 8, and a first
An arm 13 is attached, and a second arm 15 is attached to the tip of the first arm 13 so as to be rotatable about a second shaft 14 parallel to the first arm 13. The 17th arm 13 and the second arm 15 are connected to the motor 11. which is disposed on the first shaft 12 and the second shaft 14, respectively. It is driven by a reduction gear 10.

A beam near unit) B is provided at the tip of the second arm. In the linear unit B, parallel to the second axis 14,
The two slide shafts 16 and 17 and the screw 18 are arranged to form an equilateral triangle. One end of this slide shaft 16.17 is mounted on the first end plate 21 through a spherical bearing 19.20 so as to be movable in sliding motion, and the other end is mounted on the first end plate 21 through a spherical bearing 22.23. 2 end plate 24 so as to be movable. One side screw 1
Both ends of 8 are the 1st. 2nd end play) at 21.24,
It is mounted and supported through self-aligning bearings 25, 26 so as to be rotatable and movable, and through an elastic joint 27,
It is rotationally driven by a motor 28. 1st. Between the second end plates 21.24, a bearing 29°3o that can slide on the slide shaft 16.17 and a nut 31 that engages with the screw 18 are connected via spherical bearings 32, 33.34, respectively. There is a bearing plate 35 mounted so as to be movable in a sliding motion, which bearing plate 35 is fixed to the tip of the 27th arm 15. The second end plate is the rotation unit 3
A chuck unit C is provided through the chuck unit 6, and the chuck unit C has a workpiece 37 that can be opened and closed by an appropriate means.
A chuck 38 is provided for clamping.

The operation of the assembly robot constructed as described above will be explained below.

As an example, a description will be given of an operation in which the assembly robot grasps a workpiece 37 and inserts it into a chamfered hole 39 as shown in FIG.

First, motor 11. The first arm 1 is
3. Rotatably drive the second arm 15, etc., near the hole 39,
Move the work 37. Next, the motor 28 causes the screw 1 to
8 is rotated and the workpiece 37 is lowered. At this time, as shown in FIG. 3, when the workpiece 37 comes into contact with the chamfered portion of the hole 39, a horizontal component force F (the sum of Fl and F2) acts on the chuck 38. Then, as shown in Fig. 4 and Fig. 6, self-aligning bearings 25, 26, spherical bearings 19, 20, 22, 23
．． 32.33.34, Workpiece 37 by elastic joint 27
PL is held in the vertical direction and moved in the horizontal direction.

As described above, according to this embodiment, even if the center of the work 37 and the center of the hole 39 are misaligned, the work 37 can be fitted into the hole 39 extremely smoothly.

In the above embodiment, the moving direction of linear unit B is
Although it was parallel to the rotation axis of arm unit A, it cannot be said that the same result can be obtained even if the rotation axis is perpendicular to the rotation axis of the arm unit.

Effects of the Invention As described above, the present invention includes a plurality of guide shafts that are parallel to each other, a plurality of plates that pass through the guide shafts, and at least one or more of the plates that are movable relative to each other. The structure includes a screw provided parallel to the guide shaft, and a bearing that pivotally supports the guide shaft and screw with respect to the plate so that the guide shaft and the screw can be movable in a sliding manner, thereby improving the positioning accuracy and compliance characteristics of the assembly robot. Even if a slight positional deviation occurs, it is corrected by the linear unit, and extremely smooth and precise fitting can be realized, which has a great effect.

[Brief explanation of the drawing]

FIG. 1 is a front view of a conventional assembly robot, FIG. 2 is a front view of an assembly robot according to an 81 yen embodiment of the present invention, FIG. 3a is a front view of the tip part of FIG. The figure is a side view thereof, and FIGS. 4 and 6 are partial details of FIG. 3. 10...Reducer, 11...Motor, 1
3...First arm, 15...Second arm, 16.17...Slide axis, 18...
・Screw, 19, 20, 22゜23, . 32.33...
...Plate spring, 25.26 ... Self-aligning bearing, 36 ... Chuck, 37 ... Workpiece, A ... Am unit, B ......Linear unit, C107-... ...Chuck unit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 ^ Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] a plurality of guide shafts moving toward each other; a plurality of plates passing through the guide shafts; An assembly robot glue near unit 0 consisting of a screw provided parallel to the plate, a guide shirt, and a bearing that pivotally supports the screw so as to be able to perform a grinding motion.