JPS60161092A - Working unit for industrial 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 The present invention relates to a work unit attached to the tip of a work arm of a highly versatile industrial robot used in assembly work for high-mix, low-volume production.

Recently, this type of versatile industrial robot has been attracting attention, and as the use of industrial robots increases, it is used for tightening screws to be attached to the tip of the work arm, inserting parts, etc. There is a demand for the development of various work tools. With the development of this type of work tool, there is a demand for a work unit that can arbitrarily change the height of the tip of the work tool in accordance with the different heights of each work position. In response to this demand, a work unit as shown in FIG. 1 has been developed. This working unit 6 has a housing 1 fixed to an arm (not shown) that is driven by a motor (not shown) and moves on a plane, and a screw shaft 12 and a spline shaft 13 are arranged in this housing 1. It's been done. Further, a third motor 8 is arranged in the housing 1 with its Iv drive shaft facing downward.
The third motor 8 is configured to rotate the screw shaft 12 at that position. A change nut 11 that moves together with the spline shaft 13 is screwed into the screw shaft 12, and the rotation of the third motor moves the change nut 11 up and down along the screw shaft 12, moving the spline shaft 13 together. It is configured to be raised and lowered. This work unit 1
- In order to control the height of the tip, a method is adopted in which the rotation speed of the motor is detected and the motor is feedback-controlled by applying voltage to the motor so that the rotation speed becomes the desired rotation speed. However, if the motor is rotated to obtain the rotation speed corresponding to a predetermined height, the moving speed of the power tool will change when the power tool is lowered and when it is raised due to the gravity of the power tool fixed to the spline shaft. In order to compensate for this difference, an extremely complicated and expensive control device is required to change the speed characteristics, acceleration characteristics, etc. of the motor each time, making the work unit impractical. There are some disadvantages such as:

The present invention aims to eliminate the above-mentioned drawbacks, and embodiments will be described below with reference to the drawings. In FIGS. 2 and 3, reference numeral 1 denotes an industrial robot, which has a first arm 4 and a second arm 5 that are driven and rotated by a first motor 2 and a second motor 3. A housing 1 of a working unit)-6 is fixed to one end of the second arm 5. A third motor 8 is mounted on its drive shaft 9 at the top of the housing 1.
It is installed with the drive shaft 9 facing downward, and this drive shaft 9
The outer periphery of is filled with grease via an oil seal 10. On the other hand, two change nuts 11 are arranged in the housing 1 so as to be able to rotate together at that position. A screw shaft 12 is inserted into the change nut 11. Moreover, the screw left 1
A connecting tool 14 integrally connected to the encroaching spline shaft 13 is fixed to the tip of the screw shaft 2, and is configured to prevent the screw shaft 12 from rotating. The drive shaft 9 is connected to the change nut 11 via a first gear 15 and a second gear 16, and the screw shaft 12 is moved up and down by rotation of the change nut 110.

A spline shirt 1-13 is arranged in the housing 1 together with the screw shaft 12. Via the upper bearing 11 and lower bearing 18 which are held rotatably twice,
Its axis does not move and is guided so that it can freely slide up and down. Further, the connecting tool 14 is integrally movably or rotatably connected to the spline shaft 13, and the spline shaft 13 is connected to the screw shaft 12.
It is configured to move together with the A work tool 19 corresponding to a predetermined work is fixed to the spline shaft 13, and this work tool 19 is configured to be rotatable by a rotation transmitter 51320 fixed to the lower bearing 18.

Further, an air cylinder 21 is fixed to the housing 1, and the connecting tool 14 is fixed to the tip of the rod 22. This air cylinder 21 has a first supply/discharge port 23
and a second supply/discharge port 24 , the first supply/discharge port 23 is open to communicate with the atmosphere, while the second supply/discharge port 24 is configured to supply air to balance the weight of the working tool 19 applied to the spline shaft 13 . It is connected to the air supply 11ji26 via a pressure regulating valve 25 that regulates the pressure.

In the work unit 6 of the industrial robot, the third motor B is rotated according to the height of the work tool 19 at each work position. At this time, a voltage necessary to obtain the rotation speed corresponding to the desired height is applied to the third motor 8, and the third motor 8 rotates. The change nut 1 is rotated by the rotation of the third motor 8.
1 rotates with respect to the housing 7 by a predetermined number of rotations,
A screw shaft 12 screwed into this moves downward within the change nut 11. At the same time, the connecting tool 14 and the rod 22 descend, and the spline shaft 13 also descends together. At this time, the weight of the work tool 19 is not applied due to the action of the air cylinder 21, so
The gravity of the power tool 19 has almost no effect on the control of the third motor 8. Similarly, when the work tool 19 is raised, there is almost no force of gravity on the work tool 19, so when the third motor 8 is driven, the predetermined rotation speed is reliably obtained, and the work tool 19 is rotated at the predetermined speed. Positioned at height.

As explained above, in the present invention, an air cylinder having an air pressure adjusted to balance the weight of a working tool that is being raised and lowered is arranged, and the working tool is held by the rod thereof. The influence of gravity can be eliminated, there is no need to change control characteristics such as motor speed characteristics and acceleration characteristics when ascending and descending, and there is no need for a special control device, allowing the coordinate robot to move in the horizontal direction. Not only is it possible to provide a working unit driven by an extremely simple control device, but the motor also rotates the screw shaft and the nut relative to each other. It has the advantage that it only needs to have an extremely small capacity and can provide a compact work unit. Moreover, since the influence of gravity on the power tool can be ignored, the lead of the screw shaft can be increased, and as a result, not only can the lifting speed of the power tool be increased, but also the screw shaft and nut can rotate relative to each other after the motor has stopped. Therefore, there is no change in the height of the working tool, there is no hunting of the motor, and there are advantages such as instant positioning.

Although this embodiment describes a work unit that is attached to the tip of the arm of an industrial robot, as shown in FIG. Similar effects can be obtained by using the work unit of the present invention as the moving Z table 28.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of main parts showing a conventional example, Fig. 2 is an overall explanatory diagram of an industrial robot according to the present invention, Fig. 3 is a cross-sectional view of main parts of the present invention, and Fig. 4 is a cross-sectional view of main parts of an industrial robot according to the present invention. A cylinder air control circuit diagram, FIG. 5 is a sectional view of a main part showing another embodiment of the present invention. 1 Industrial robot I., 2 First motor, 3 Second motor, 4 First arm, 5 Second arm, 6 Working units 1 to . 7 housing, 8 third motor, 9 drive shaft, 10 oil shuffle, 11 change nut, 12 screw shaft, 1
3 spline shaft, 14 i! i coupling, 15 first gear, 16 second gear, 11 upper bearing, 18
Lower bearing, 19 construction work 1, 20 flil transfer 31 m 4
M, 21 Air cylinder, 22 Rod, 23 1st
Supply/discharge port, 24 Second supply/discharge port, ? 5 pressure regulating valve, 2
6 Air supply source, 27 X table, 28 Z table, patent applicant Nitto Seiko Co., Ltd. Figure 1 8 Figure 2 Figure 5 Procedure if? Official document (method) May 15, 1980 Director General of the Japan Patent Office 1. Indication of the case 1988 Patent Application No. 16830 2. Name of the invention Industrial robot work units 1 to 3. Case of the person making the amendment Relationship with Patent applicant 20-4 Umegahata, Ikura-cho, Ayabe-shi, Kyoto Prefecture, date of amendment order Meiji II engraving (no change in content)

Claims (1)

[Claims] (1) An industry in which a screw shirt 1 and a change nut screwed thereon are arranged in a housing, and a motor is used to move the screw shaft and change nut relatively to position the work tool at a predetermined height. In an industrial robot, an air cylinder is arranged to the right of a rod that moves together with a working tool, a first supply/discharge port and a second supply/discharge port are provided in the air cylinder, and the supply/discharge port is opened. On the other hand, the work unit is characterized in that an air supply source is connected via a pressure 1ull valve on the second supply/discharge day. 4. An industrial device in which a screw shaft and a change nut screwed into the housing are disposed in the housing, a motor is disposed in the housing, and the shaft is moved in parallel with the screw shaft by the motor. In the robot for use in the air cylinder, an F-cylinder is fixed to the housing, a shaft is attached to the bottom of the housing so as to move together, and the air cylinder is provided with a first supply/discharge port and a second supply/discharge port, and a first supply/discharge port is provided.
A work unit characterized in that a supply/discharge port is opened, and an air supply source is connected via a pressure regulating valve on a second supply/discharge day.