JPH01228787A - Cylindrical coordinate type robot - Google Patents

Abstract

PURPOSE:To shorten a moving locus of a working axis by holding a holded body for an arm linearly movable along over nearly whole length in longitudinal direction of an arm holding member on an arm holding member, further providing a movable base having a working axis on the arm linearly movable in longitudinal direction thereof. CONSTITUTION:Together with linear movement on an arm 3 along longitudinal direction of an arm holding member 2 on driving with a motor, a movable base 4 equipped with a working axis 5 is made to move linearly, along a side face of the arm 3 to longitudinal direction thereof. Together with broad elongation, thereby, in linear movement distance of the working axis 5, moving locus thereof is made to shorten. As the result thereof, it can be done to enlarge working range of a cylindrical coordinate type robot and to shorten working time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to industrial robots, and particularly to cylindrical coordinate robots.

(Prior Art) Cylindrical coordinate robots conventionally used as industrial robots generally have an appearance as shown in FIG. 7, and have a base 710 that rotates.

Linear movement of arm 73 and base 71 or work axis 74
It has the function of vertical movement.

These cylindrical coordinate robots have cables extending inside and outside the robot to guide power and signals, and the base must be rotated to prevent damage to the cables due to twisting or pulling. Stoppers are provided to prevent free movement. Therefore, when looking at the robot from above as shown in Figure 8, there is always a range in which work cannot be performed by the work axis, and as a result, the movement trajectory of the work axis becomes longer than necessary. had an impact on the Furthermore, even if these drawbacks were eliminated and rotational movement became possible, if the base rotates freely many times, it is likely that the absolute position will be distorted, and from the viewpoint of accuracy. Undesirable.

Furthermore, a ball screw for linear movement of the arm 73 is built into the arm holder 72, and the linear movement of the bolt, nut, or screw is replaced by the linear movement of the IT achie 73, so that the It was impossible to make the operating range of 473 longer than the entire length of arm holding portion 72. Therefore, in order to lengthen the operating range of the arm 73, the total length of the arm 73 must be increased, and the arm holding portion 72° arm 73 becomes larger than necessary.

In addition, in order to secure the vicinity of the base 71 as a work area, it is necessary to provide a pivot axis of the arm holding part 72 on the arm 73 side, which prevents the arm holding part 72 from protruding significantly rearward. This not only increases the inertia of the arm more than necessary, but also creates a space at the rear of the robot that cannot be used as a work area, conversely narrowing the work area near the base 71.

(Problem to be solved by the invention) From the above, in the conventional cylindrical coordinate robot,
Because there was no suitable method to cover the 360° movement range of the base rotation, the movement trajectory of one work axis became longer than necessary, which affected the high efficiency of work. . Furthermore, in order to widen the range of motion, it was necessary to increase the size of the area around the robot arm.

[Structure of the invention]

(Means for solving problems) In order to solve the above-mentioned problem, in the present invention.

A base capable of rotational movement, an arm holder held on the base such that its longitudinal direction is orthogonal to and intersects with any plane including the rotation axis of this base, and the same direction as the longitudinal direction of this arm holder. The arm holder has a longitudinal section, and the object to be held, which is provided in a direction perpendicular to the direction of the longitudinal section, can move in a straight line along almost the entire length of the arm holding section in the longitudinal direction. , consists of an arm held by an arm holding part, and a moving base having a working axis, which is held by the arm so as to be able to move linearly along almost the entire length of the arm. It is a cylindrical coordinate robot.

(Function) With the above configuration, the arm moves linearly along the longitudinal direction of the arm holding part, and the moving base moves linearly along the longitudinal direction of the arm holding part, so the work axis The straight line travel distance will be significantly longer. What's more, the work axis can be moved to places where it was previously impossible to move it without using the rotational movement of the base, or where it was previously impossible to move the work axis.

Can be easily moved by linear motion.

Furthermore, since linear movement of one working axis is often used, the locus of movement of one working axis is shortened.

Therefore, a cylindrical coordinate robot that can expand the work range and improve work efficiency is realized.

(Example) Hereinafter, the invention will be described in detail with reference to the drawings.

FIG. 1 shows a cylindrical coordinate robot showing an embodiment of the present invention. An arm holder 2 is mounted on a base 1 which has a rotation axis (hereinafter referred to as the first axis) and is rotatable, and is mounted on a plane including the first axis (a plane perpendicular to the plane of the paper in FIG. 1). They are fixed so that their longitudinal directions are orthogonal and intersect at the center. The arm 3, which has a longitudinal section in the same direction as the longitudinal direction of the arm holding section 2, has an object to be held 3 at the center of the longitudinal section.
is held by the arm holder 2 in a linearly movable state and moves along the lower surface of the arm holder 2. and similarly 1
A moving base 4 equipped with a working axis 5 having a rotation axis (hereinafter referred to as the third axis) and a vertical axis (hereinafter referred to as the fourth axis) is held on the arm 3 in a state in which it can move linearly in the longitudinal direction of the arm 3. and moves along the side of arm 3. The linear movement of the arm 3 and the movable base 4 (hereinafter, these movement axes are collectively referred to as a second axis) is performed by driving a motor 8 attached to the arm holder.

Next, the arm holding portion and arm in the fifth embodiment.

The movement mechanism of the moving base and the movement mechanism of the second axis of the pick are shown. FIG. 3 is a schematic diagram of the operating mechanism.

Two guides 36a, 36b and a screw shaft 37 are installed in parallel in the arm holding part 32 in the longitudinal direction thereof, and the inside of the held body 33 in the center of the longitudinal part of the arm 33 is 2 holes = 7 guides 36a, 36b
The screw shaft 37 is fitted therethrough. Incidentally, the held body is provided with a screw thread (not shown) so as to correspond to the screw shaft 37. In addition, one pulley 3 is provided at the front right and rear left of the arm 33 relative to the plane of the paper.
Ropes 9a and 39b are rotatably held by the arm 33, and ropes 40a and 40b are connected with one end to the arm holding portion 32' via these pulleys 39a and 39b.
The other end is fixed to the moving base 34. The movable base is supported by two parallel linear guides 41a and 41b (41b not shown) installed in the longitudinal direction of the arm 33, and the movement direction of each arm relative to the arm holder 32 and the arm 33 are The moving direction of the moving base 34 relative to the moving base 34 is the same direction.

FIG. 4 shows the operation of the mechanism constructed in this way. Now arm 33. From the state in which both the movable bases 34 are in the neutral position (Figure (a)), the motor 38 is driven to rotate the screw shaft 37 (not shown) and move the arm wing by l to the right (Figure (b). )).

This applies tension to the rope 40a and pulls the movable base to the right via the pulley 39a. Since the pulley 39a acts as a movable pulley, the movable base 34
moves to the right a distance twice that of arm 33 @ 21.

Next, when arm 33 is moved to the left, rope 4
Tension is applied to the movable base 3 via the pulley 39b.
4 is pulled to the left. And similarly, moving base 3
4 will move to the left by twice the distance of the arm feather.

Due to the movement of the second axis as described above, the work axis 5 can be linearly moved from the first axis by L to the left and right, as shown in FIG.

FIG. 2 is a view of the cylindrical robot shown in FIG. 1 viewed from directly above. As you can see from this figure, the robot's working range is the distance A between the first axis and the work axis when the arm 3 is extended the most, and the distance A when the first axis and the work axis are closest to each other. Fills everything in the annular space determined by B.

FIGS. 5 and 6 compare the movement trajectories of the work axes of the cylindrical coordinate layer robot of the present invention and the conventional cylindrical coordinate robot. Here, movement of the work axis to a position 180 degrees away from the first axis is shown.

According to the present invention, the movement of the working axis is completed mainly by the linear movement of the second axis. Therefore, using only the first axis, 180
Compared to the conventional example, which requires rotational movement of 1°, the first
Since the radius of rotation for the shaft can be changed, the locus of movement of the working axis can be shortened, the load on the first axis motor can be reduced, and the working axis can be moved at high speed. Incidentally, such an effect is sufficiently observed even when the turning angle is not 180°.

By using the mechanism shown in Figures 3 and 4, the linear motion speed of the second axis (movement-based linear motion speed)
The robot's travel time is twice that of conventional robots, and the travel time is cut in half. Furthermore, there is no need to install separate drive motors on the arm and moving base, and only one motor is required.
Second axis control can also be easily performed.

As described above, although the mechanism shown in Fig. 3 was used as the operating mechanism for the second axis in this embodiment, it is not necessary to use this operating mechanism in particular. It may also be such that the mobile base and the mobile base are operated separately. Even with such a device, it is possible to shorten the movement trajectory of the work axis and shorten the work time.

In addition, for example, when the cylindrical coordinate type robot of the present invention is installed on a ceiling surface, the working axis 5 shown in FIG.

The structure allows the movement of the second axis to pass over the first axis. In this way, the working axis 5 of the robot can cover the entire inside of the circular space whose radius is the distance A, and work efficiency is greatly improved.

〔Effect of the invention〕

As described above, in the present invention, the work range of the cylindrical coordinate robot is expanded, the movement trajectory of the work axis can be shortened, the work time can be shortened, and high work efficiency can be realized.

[Brief explanation of the drawing]

1 and 2 are a front view and a top view of a cylindrical coordinate robot showing an embodiment of the present invention, and FIGS. 3 and 4 are perspective views and operations of the second axis operating mechanism used in the present invention. Schematic diagram of 5th
6 are comparison diagrams of movement trajectories of working axes of the present invention and a conventional example, and FIGS. 7 and 8 are a front view and a top view showing a working range of a cylindrical coordinate type robot showing an example of the conventional example. . 1... Base 2, 32... Arm holding part 4
．． 34...Moving base 5...Work axis 8.38
... Motor agent Patent attorney Nori Ken Chika Yudo Mitsuyuki Matsuyama Figure 1 Figure 2 Figure 3 (b) Figure 4 Akira Kubaso〉 Figure 5 Figure 6

Claims (1)

[Scope of Claims] A base capable of rotational movement; an arm holder held by the base such that its longitudinal direction is orthogonal to and intersects with an arbitrary plane including a rotation axis of the base; and the arm holder. having a longitudinal part in the same direction as the longitudinal direction of the part;
A held body provided in a direction perpendicular to the longitudinal direction,
an arm held by the arm holding part so as to be capable of linear movement along the longitudinal direction of the arm holding part; and an arm held by the arm holding part so as to allow linear movement along the longitudinal direction of the arm holding part; A cylindrical coordinate robot characterized by comprising a movable base that is held and has a working axis.