JPS59214579A - 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 Field of Industrial Application The present invention relates to a horizontal articulated industrial robot used for various industrial applications.

Conventional Structure and Problems The horizontal articulated industrial robot has a rotary actuator 3 connected to a fixed base 1 via a first rotary shaft 2, as shown in FIGS. A first arm 4 is rotatably supported at one end thereof, and a second rotation shaft 5 having a rotation actuator 6 parallel to the first rotation shaft 2 is attached to the other end of the first arm 4. A second arm 7, which is also rotatably supported at one end, is pivotally connected via the second arm 7, and a vertical movement drive actuator 9 is connected to the tip of the second arm 7. A tool holder 1o that is slidably and rotatably supported is pivotally mounted via the third rotating shaft 8.

As a means for controlling the rotational posture of the tool holding portion 1o about the third rotation axis 8, toothed belt teeth 11 connected to the rotation actuator 17 are connected to the first rotation axis 2.
Toothed belt pulleys 12 and 14 integrally supported in two stages and rotatably supported on the second rotating shaft 6, and on the third rotating shaft 8,
A toothed belt wheel 16 rotatably supported integrally with the tool holder 10 is arranged, and between each toothed belt wheel,
This is done by connecting the toothed belts 13 and 16 stretched together and driving the rotation actuator 17. In addition, with the above configuration, the toothed belt wheel 11.12.14
and 16 have the same pitch diameter. The reason for this is that by having the same pitch diameter dimension, no matter what position the first arm 4 and the second arm 7 move to, even without rotating the rotary actuator, the third arm This is because a corrective rotational movement is automatically applied to the rotational axis, and the rotational posture of the tool holder 10 is always kept constant. (Such a parallel movement configuration is generally employed in drafting instruments and the like).

With the above configuration, the robot becomes a horizontal multi-joint robot with four degrees of freedom, and by controlling each actuator, it can move arbitrarily within a range of motion on a plane.

However, in the field where general robots are used, depending on the application, there is an extremely strong need for cheaper narrow hots with at least the degree of freedom. For this reason, there are many horizontal articulated robots that only move the tool holding shaft 1Q up and down using a pneumatic cylinder or the like (no movement distance control) that simply drives the vertical movement actuator 9 back and forth.

This is because although the degree of freedom is three, this allows for significant cost reductions in terms of control and the like. Third
A conventional example is shown in the figure.

7 is a second arm; 9 is a pneumatic cylinder; 1o is a tool holder; 21 is a holder that is rotatably supported by the second arm 9 and serves as a sliding guide in the axial direction while regulating the rotation of the tool holder 10; Reference numeral 16 denotes a toothed belt wheel which is fixed to the holder 21 and which gives a rotational attitude to the tool holder by means of the toothed belt 16.

In the above configuration, the driving force of the pneumatic cylinder fixed to the second arm 7 is transmitted to the tool holding part 1 through the connecting fitting 19.
o is slid up and down, and its movable stroke is determined by the moving distance P until the bolt 18 attached to the connecting fitting 19 comes into contact with the stopper pin 20, and is constant. (The moving distance P can be adjusted with the bolt 18, but it remains constant when set to -1.) Therefore, as shown in Fig. 2, for example, when an article is moved from position A to position B during handling work, etc. If listed, A
This method has a disadvantage in that the height at which the article is supplied at position B and the height at the transfer position at position B must always be the same height, which significantly limits the scope of application in terms of robot usage.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention provides an object to improve the supply height and transfer of articles even when the vertical sliding actuator of an industrial robot is an actuator that reciprocates at a constant stroke between two predetermined points, such as a pneumatic cylinder. To provide an inexpensive industrial robot that can vary and adjust the vertical sliding stroke of a tool holder at each point, even if the heights are not necessarily the same.

Structure of the Invention The present invention provides a so-called horizontal articulated industrial robot having a plurality of parallel rotation axes, in which a tool holder at the tip is driven by an actuator such as a pneumatic cylinder whose position in the vertical direction cannot be controlled. The vertical position of the tool holder is controlled by utilizing the relative positional relationship between the tool holder and the actuator via the holder, which rotates and moves in parallel with the rotation of each arm. This is achieved by providing one or more stoppers that regulate the vertical drive position of the actuator corresponding to the position in the horizontal plane of the actuator, which allows handling between multiple positions with different vertical positions with an inexpensive structure. It has the effect of allowing work to be done.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 is a front cross-sectional view of the third rotating shaft portion of the horizontal articulated robot according to the embodiment of the present invention, and FIG. 5 is a cross-sectional view of the Q-0 portion in FIG. 4.

Note that the configuration of the main body of the horizontal articulated industrial robot and the attitude control means centered on the third rotation axis of the tool holder are the same as those shown in FIGS. 1 and 2, and have already been described above. is omitted. Therefore, the third rotating shaft portion, which is the key point of the present invention, will be explained with reference to FIGS. 4 and 5. 2
2 is the second arm of the horizontal articulated robot, 23 is the second arm
A pneumatic cylinder 24 for reciprocating between two points, which is fixed to the arm 22, has one end fixed to a movable part of the pneumatic cylinder, and the other end connected to the tool holding part 2 through a rotation bearing 26. The metal fitting 28 is a holder that is rotatably supported by the second arm 22 and serves as a sliding guide in the axial direction while regulating the rotation of the tool holding part 27 via a key 30, and has an opening in the flange portion thereof in the same window as the center of rotation. It has a v-shaped groove 29 that is narrower on the outside. Stoppers 31 and 32 each have a predetermined length and are fixed at a predetermined position at an angle α through a V-shaped nut 33 fitted into the groove 29. A toothed belt wheel 3 and 6 is fixed to the holder 28 and provides a rotational attitude to the tool holder 27 by means of a toothed belt 36.

The operation of the third rotating shaft portion configured as described above will be described below.

First of all, when performing link work etc. with an industrial robot, as shown in Figure 2, if we consider the case where goods are supplied at point A and transferred to point B, the third rotating shaft section at point A is In this operation, the tool holder 27 is lowered by the pneumatic cylinder 23 via the connecting fitting 24, and the bolt 26 is moved to the stopper 31.
The stroke of contact with Pl, that is, the stroke descends, and the object can actually be gripped by a gripping device or the like attached to the tip of the tool holding portion 27. When the object is gripped, the tool holder 27 rises, each arm of the robot then rotates, and the third rotation axis moves to a predetermined point B. At this time, even if the rotation actuator 17 does not operate, each arm rotates and the third rotation axis is rotated by the angle α corresponding to the amount of rotation of each arm by the attitude control means. Ru. That is, the holder 28
At the same time, the tool holder 27 is rotated by an angle α.

Therefore, at point B, when the tool holding part 27 is lowered again by the pneumatic cylinder 23, the connecting fitting 24
The bolt 26 attached to the
The downward stroke can be changed to P2 since it comes into contact with the stop horn (-32) set at a position α angle away from the rotation axis.

In this way, if the movement angle of the points sequentially moved from the starting point of the third rotation axis of the robot arm with respect to the center position of the first rotation axis is known in advance,
Stoppers 3 of different lengths are provided on the flange surface of the holder 28.
1 and 32, etc., by sequentially setting them in accordance with predetermined movement angles, there is an effect that the downward stroke of the tool holder 27 can be successively changed.

In this embodiment, the stoppers 31 and 32 and the holder 28 are connected to each other by forming a V-shaped groove 29 on the circumference of the flange of the boulder 28, with the opening narrowed outward in the same window as the center of rotation. with the same shape that fits into the groove 29.
Although it is possible to fix it at any position on the circumference via the shaped nut 33, the above-mentioned ■-shaped groove shape may be changed to a T-shaped groove shape, and instead of the groove, a plurality of tapped holes may be used. Alternatively, the stoppers 31 and 32 may be attached by selecting the tapped holes.

Further, in this embodiment, as a means for controlling the rotational posture of the tool holder 27 about the third rotation axis, a parallel movement means is used in which a toothed belt wheel having the same pitch size and diameter is arranged at the rotation axis of each arm. However, a similar effect can be obtained by using a link mechanism that forms a parallelogram that similarly swings around the rotational axis of each arm.

Effects of the Invention As described above, the present invention provides an inexpensive reciprocating actuator (such as a pneumatic cylinder) for sliding the tool holder at the tip of a horizontal articulated robot having a plurality of parallel rotation axes.
In order to control the position of the sliding stroke, the rotational index of the tool holding section obtained by the posture control function using the rotation axis of each robot arm is used to change the relative positional relationship with the actuator in the horizontal plane. By providing a stopper means, it is possible to significantly reduce costs from the control side, etc., and expand the scope of application from the robot usage side, which has great effects. .

[Brief explanation of the drawing]

Figure 1 is a front view of the horizontal articulated robot, and Figure 2 is the front view of the horizontal articulated robot.
3 is a front sectional view of the third rotating shaft in the conventional example, FIG. 4 is a front sectional view of the third rotating shaft in this embodiment, and FIG. 5 is a Q-- It is an arrow view of Q section. 1... Base, 2... First rotating shaft, 3
・Rotation drive means (rotary actuator) for the first arm, 4...first arm, 5...second
Rotation axis, 6... Rotation of second arm 1 Drive means (rotary actuator), 7... Second arm, 8...
...Third rotating shaft, 27.10... Tool holding part, 23... Actuator (pneumatic cylinder) that reciprocates between two points in the direction of the third rotating shaft, 25... ...
・Contact part (Pol)), 3'1.32... Stopper, 11... First toothed belt wheel, 12...
...Second toothed belt pulley, 14.Old...Third toothed belt pulley, 15,35...Fourth toothed belt pulley,
13.16・Old・Toothed belt. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2

Claims (4)

[Claims] (1) A first arm rotatably supported at one end by a base via a first rotating shaft, a driving means for rotationally driving this arm, and a first arm at the other end of the first arm. a second arm rotatably supported via a second rotation axis parallel to the first rotation axis; a driving means for rotationally driving the second arm; a tool holder supported rotatably and slidably in the direction of the third rotation axis parallel to the axis;
an actuator that is provided on the arm and reciprocates the tool holder between two points in the direction of a third rotation axis with respect to the second arm; attitude control means for keeping the rotational attitude constant regardless of the rotations of the first and second arms; and an attitude control means that rotates integrally with the tool holder in the direction of the third rotational axis, and rotates in the direction of the third rotational axis. is provided with a tool holder positioning means that has an immovable relationship with the second arm and prevents movement of the tool holder in one direction in the third rotation axis direction; The means includes one or more stoppers that come into contact with a contact portion provided on the actuator to prevent movement of the tool holding portion, and the actuator is brought into contact with the third rotating shaft at the same center. An industrial robot characterized in that the robots are located on the same circumference having a radius equal to the distance to the end of the robot. (2) The stopper of the tool holder positioning means is
The industrial robot according to claim 1, wherein the directional position of the third rotation axis can be adjusted. (3) The industrial robot according to claim 1, wherein the stopper of the tool holder positioning means is movable on the same circumference with respect to the tool holder positioning means. (4) The attitude control means includes first and second toothed belt wheels rotatably provided on the first rotation shaft and the second rotation shaft, respectively, and a toothed belt wheel stretched between the two toothed belt wheels. A belt, a third toothed belt wheel having the same capacity and diameter as the second toothed belt wheel, and rotating together with the second toothed belt wheel, and a third toothed belt wheel rotating around a third rotating shaft and rotating integrally with the tool holding part. Claim 1 comprising a fourth toothed belt wheel and a toothed belt stretched between the third and fourth toothed belt wheels, the first toothed belt wheel being fixed to a base. The industrial robot described.