JPS6161954B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an industrial robot, and particularly to one in which the axis of the forearm supporting a hand or tool is always oriented in a fixed direction.

B. Prior Art Conventionally, the axis of the hand or the forearm supporting the tool was always oriented in a fixed direction during work, for example, drilling many holes perpendicularly in a flat plate, or tapping into many holes provided in a flat plate. For industrial robots (including manipulators) that screw bolts into multiple screw holes in a flat plate, rectangular coordinate systems, cylindrical coordinate systems, or polar coordinate systems are used. .

For example, when drilling many holes in a vertical board, the drill held by the hand must be perpendicular to the board even if the hand is moved horizontally parallel to the board; The drill must remain perpendicular to the board even when moving.

For this reason, conventionally two sets of parallel links have been used. That is, if the surface formed by the parallel links is defined as a link surface, a parallel link having a link surface parallel to the plate and a parallel link having a link surface perpendicular to the plate are connected in series. In this way, the functions of the parallel links work in two mutually perpendicular directions.

C Problems to be solved by the invention However, since the parallel links have a two-stage configuration,
Not only is the structure complex and the number of parts is large, but the length from the robot's attachment point to the floor etc. to the hand becomes large and heavy, and the second parallel link is placed on top of the first parallel link. and its drive source, a large driving force is required to drive the first stage parallel link, which limits the speed of work and results in a large size.

Therefore, an object of the present invention is to provide an industrial robot that eliminates such drawbacks.

D. Means for Solving the Problems In order to achieve the above object, the industrial robot of the present invention is configured as follows.

A first shaft is pivotally supported parallel to the base, and the first shaft is rotatably driven via a first rotary drive device attached to the base, and a first beam is attached to the first shaft in the same manner as the first shaft. a pair of link members extending in a direction and fixed to each other, one ends of the pair of link members being parallel to each other and pivotally attached via a connecting shaft in a direction perpendicular to the first axis; are provided rotatably through a second rotary drive device attached to the first beam, and each link member and Both ends of the second beam are pivoted so as to form a parallelogram together with the first beam, and a second beam is connected to the second beam through a second axis parallel to the first axis near the end of the hand support rod. At the same time, the end of the hand support rod and the base are connected via a connecting rod having a universal joint at both ends, and the hand support rod and the base, and the pair of link members and the connecting rod are both parallel to each other. This is the setting.
Here, the pair of link members, the first beam and the second beam are connected to each other.
The beam constitutes one parallel link, and the line on the link surface of this parallel link, the hand support rod, the connecting rod, and a part of the base constitute another parallel link.

E. Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention. In the figure, reference numeral 1 denotes a rectangular plate-shaped base, on which a first shaft 3 is pivotally supported via a pair of bearing brackets 2 and 2' which are erected at appropriate distances. A reversely rotatable first rotary drive device 4, such as an electric motor or a hydraulic motor, is appropriately installed, and the first shaft 3 and the rotating shaft 4a of the first rotary drive device 4 are appropriately connected. .

A first beam 5 is fixed to the first shaft 3 and extends in the same direction as the first shaft 3. 1st
The beam 5 forms an upper arm together with a link member etc. which will be described later, and one end of a pair of link members 6, 6' is provided at both ends of the beam 5 parallel to each other and in a direction perpendicular to the first axis 3. are pivotally connected via a connecting shaft 7. One link member 6' is rotatably provided via a second rotary drive device 8 mounted on the first beam 5 and rotatable in forward and reverse directions, such as an electric motor or a hydraulic motor. Both ends of the second beam 10 are connected to the other end of each link member 6, 6' via connecting shafts 9, 9 parallel to the connecting shaft 7 on the one end side.
Together with the beam 5, it is pivoted so as to form a parallelogram, or in other words, to form a four-bar parallel link.

A portion near one end of a hand support rod 12 extending in a direction perpendicular to the second shaft 11 is pivoted to the second beam 10 via a second shaft 11 parallel to the first shaft 3 . The hand support rod 12 serves as a forearm that supports the hand or tool 13 at its other end, and in order to always be oriented in a certain direction, its one end and the base 1 are connected at both ends to a universal joint 14a such as a globe-shaped universal joint. 14
b and is connected via a connecting rod 14 having the same length as the link members 6, 6'. Here, the connecting rod 14 is parallel to the pair of link members 6, 6', and the hand support rod 12 is parallel to the base 1. That is, a line on the link surface of the parallel link constituted by the pair of link members 6, 6', the first beam 5, and the second beam 10, a part of the hand support rod 12, and the connecting rod 14, Another parallel link is formed with a part of base 1.

Next, the operation of such an industrial robot will be explained. When the first rotary drive device is actuated, the pair of link members 6, 6' rotate around the first shaft 3, and the hand support rod 12 maintains its axis constant due to the function of the parallel links including the connecting rod 14. While held in the direction, it moves forward and backward relative to the workpiece, and moves up and down as shown in the figure. On the other hand, when the second rotation drive device is actuated, the link member 6' rotates around the connecting shaft 7, and the hand support rod 12 always follows its axis due to the parallel link function including the pair of link members 6 and 6'. Move left/right or up/down while holding in a fixed direction. Hand support rod 12 and connecting rod 14
Universal joints 14a, 14b are connected to the base 1.
Since these two parallel links are able to move independently without being influenced by the other side, they perform their respective functions individually.

F. Effects of the Invention As explained above, according to the present invention, by connecting both ends of the connecting rod to the hand support rod and the base via the universal joint, two sets of parallel links can be overlapped without being connected in series. Since it is set up, it has the following effects.

(a) Since parallel links are not connected in series, the structure of the robot is simpler and smaller, and the number of parts is significantly smaller than in the past.

(b) Since the distance from the robot installation part to the hand is about half as short as before, the driving moment is reduced, and the driving force required to move the hand is smaller than before. In addition, when parallel links are connected in series as in the past, a heavy drive source must be installed near the parallel links on the hand side, which places a heavy burden on the drive source that drives the parallel links on the installation side. In the present invention, since both drive sources are located near the installation part, only a small driving force is required. This shows that it is extremely advantageous for high-speed operation.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of an industrial robot according to the present invention. DESCRIPTION OF SYMBOLS 1... Base, 3... First shaft, 4... First rotation drive device, 5... First beam, 6, 6'... Link member,
7, 9...Connection shaft, 8...Second rotational drive device, 10...
Second beam, 11...Second shaft, 12...Hand support rod, 14...Connecting rod, 14a, 14b...Universal joint.

Claims (1)

[Claims] 1. A first shaft is pivotally supported on a base, and this first shaft is rotatably driven via a first rotation drive device attached to the base, and a first beam is attached to the first shaft in the same manner as the first shaft. a pair of link members extending in a direction and fixed to each other, one ends of the pair of link members being parallel to each other and pivotally attached via a connecting shaft in a direction perpendicular to the first axis; are provided rotatably through a second rotary drive device attached to the first beam, and each link member and Both ends of the second beam are pivoted so as to form a parallelogram together with the first beam, and a second beam is connected to the second beam through a second axis parallel to the first axis near the end of the hand support rod. and connecting the end of the hand support rod to the base via a connecting rod having a universal joint at both ends, and connecting the hand support rod to the base and the pair of link members to the connecting rod. An industrial robot characterized by its rods being set parallel to each other.