INDUSTRIAL ROBOT HAVING REPLACEABLE MODULES

Abstract: In an industrial robot having interchangeable modules assembled on a base (2) provided with a built-in drive mechanism, blocks (1, 3, 4, 5, 9) of the robot are composed of interchangeable members having common structures which can be selected and assembled modularly. The engaging por­ tions of these members are formed to have inter­ changeability with modules of other specifications. Accord­ ingly, the specifications of the robot can be changed easily with modules having a wide range of effective application. The enables each block constituting an industrial robot to be assembled and diassembled easily.

Description: The present invention relates to an industrial robot having replaceable modules, the robot being composed of blocks each of a unit structure. Industrial robots have been widely used in various fields in recent years. Fig. 3 of the accompanying drawings is a side elevational view showing by way of example a horizontally articulated industrial robot having an angularly movable post mounted on a bed installed on a floor. A post 1 is mounted on a bed 2 installed on a floor and is angularly movable over a prescribed angular range (ϑ). The bed 2 houses therein a turning mechanism 21 for rotating the post 1. A support shaft 4 is inserted in the post 1 from above and on its upper end supports a first arm 3; a second arm 5 which is horizontally angularly movable is mounted on the distal end of the first arm 3. A wrist 51 is attached to the distal end of the second arm 5. The post 1 houses therein a drive mechanism 6 vertically movable within a prescribed range (Z) for controlling the height of the first arm 3. The industrial robot of the type described is designed and manufactured to desired individual specifications. Therefore, for manufacturing an industrial robot with a post 1 having a different height, or first and second arms 3, 5 having different lengths, a long period of time is required before the robot is completed, and the cost of manufacture is high as the robot is customized. There exist industrial robots having a modular construction - see for instance DE-U-8511473. Here the rotary drive is at one end of the column or shaft and the vertical or longitudinal drive for the arm support is at the other end and requires separate access from that end. The present invention provides an industrial robot having replaceable modules for assembly on a bed housing a rotary drive mechanism, comprising a plurality of functional blocks and at least one engagement mechanism for separably engaging one functional block to another or to the bed, wherein the functional blocks include a post to be turned by the rotary drive mechanism, a support shaft supported on the post for translatory movement, a translatory drive for producing this movement, and an arm disposed on the support shaft, characterised by the further provision of an upper base located between the bed and the post and housing a brake mechanism for the translatory drive. Each of the functional blocks of the industrial robot is of a unit structure which can easily be assembled and disassembled, and each block has a compatible engagement portion for easy replacement. Therefore, blocks of the same kind can easily be replaced, and blocks of different specifications can be replaced. An embodiment of the present invention will hereinafter be described in specific detail with reference to the drawings, in which Fig. 1 is a vertical cross-sectional view of part of an industrial robot having replaceable modules, representing an embodiment of the invention; Fig. 2 is a schematic view showing modular functional blocks in the industrial robot; and Fig. 3 is a side elevational view of a conventional horizontally articulated industrial robot. Fig. 1 is a vertical cross-sectional view of an industrial robot having replaceable modules in accordance with the present invention. Those parts which are identical to those shown in Fig. 3 are denoted by identical reference numerals, and will not be described in detail. An upper portion 41 of a support post 4 shown in Fig. 1 has a flange having a plurality of screw holes 42 for attachment of a first arm 3. A bottom plate 11 of a post 1 and an upper portion of an upper base 9 are attached to each other by means of attachment screws 91. Each of the blocks of the first arm 3, the post 1, and the upper base 9 is of a unit structure. These unit members have attachment screw positions and other engagement portions which are compatibly structured such that arms, posts, and upper bases of different specifications can be installed. The post 1 houses therein a support shaft 4 supporting the first arm 3 on its upper portion for controlling the height of the first arm 3, a translatory drive mechanism 6 comprising a ball screw 61 and a nut 62 for vertically moving the support shaft 4, and a transmission mechanism comprising a belt 72 and pulleys 63, 71. A drive motor 7 having a motor pulley 71 is mounted on the bottom plate 11 of the post 1 for rotating the ball screw 61 through the belt 72 trained around the drive pulley 63 mounted on the ball screw 61. Since the nut 62 threaded over the ball screw 61 is supported on a side of the support post 4, the support shaft 4 is vertically moved upon rotation of the ball screw 61 to move the nut 62 upwardly or downwardly. The ball screw 61 is supported on the bottom plate 11 of the post 1 by means of a bearing 64. A brake mechanism 8 is mounted in the upper base 9 and coupled to the lower end of the ball screw 61 for controlling the rotation of the ball screw 61. The brake mechanism 8 includes a fixed brake member 81 having an electromagnetic coil. When the electromagnetic coil is energized to electromagnetically attract a brake shoe 82 attached to the ball screw 61, the rotation of the ball screw 61 is braked to brake the vertical movement of the support shaft 4 through the nut 62. The support shaft 4 can easily be detached from the post 1 by turning the ball screw 61 to move the nut 62 up to the upper end of the ball screw 61. Fig. 2 schematically shows, by way of example, modular functional blocks of an industrial robot of the present invention. Those partss which are identical to those shown in Figs. 1 and 3 are denoted by identical reference numerals. Denoted at 10 in Fig. 2 is a control unit housing a control device for controlling the drive motor 7 and the turning mechanism 21 which angularly moves the post 1 and also for controlling another operation mechanism (not shown) of the industrial robot. The first arm 3, the support post 4, the post 1, and the upper base 9 can individually be attached and detached as described above with reference to Fig. 1. Other blocks (not shown) can also be attached and detached using attachment screws and other engagement mechanisms. Operation of the present embodiment thus constructed will be described below. As described above, the blocks of the industrial robot are separably constructed. Therefore, when an industrial robot having a different range (Z) of vertical movement of the first arm 3 is desired, the lengths of the support shaft 4, the post 1, and the ball screw 61 are varied to those which meet the desired range of vertical movement. The blocks are then assembled without changing the drive motor 7, the brake mechanism 8, and the other members. The industrial robot having the desired movement range can thus be produced. When an arm that is extensible and contractable, rather than angularly movable, is to be used in place of the second arm 5, the second arm 5 may be detached from the engagement mechanism at the distal end of the first arm 3, and an extensible and contractable arm having an engagement portion compatible with the engagement mechanism may be attached. If the brake mechanism 8 is not necessary, the attachment screws 91 interconnecting the upper base 9 and the post 1 are removed, and the post 1 is detached to open the interior of the upper base 9 so that easy access can be gained into the upper base 9. Then, the brake mechanism 8 is detached, with the result that an industrial robot of desired specifications can easily be obtained. As described above, the respective blocks can individually be detached, and various types of work can easily be effected since the blocks are compatibly constructed. Although a certain preferred embodiment has been shown and described, it should be understood that many changes and modifications may be made therein without departing from the scope of the claims. Industrial Applicability According to the present invention, there is provided a module system for an industrial robot comprising various blocks each of a unit structure, the blocks being easily attachable and detachable and having engagement portions which are compatible with those of other specifications. Therefore, different specifications can easily be met, a time period required to manufacture a desired industrial robot can be shortened, and the cost of manufacture can be reduced. Since the respective blocks can easily be detached, the industrial robor of the invention can be maintained and inspected with ease. The industrial robot can thus be increased in reliability and can easily be repaired.

Claims: 1. An industrial robot having replaceable modules for assembly on a bed (2) housing a rotary drive mechanism, comprising a plurality of functional blocks and at least one engagement mechanism for separably engaging one functional block to another or to the bed (2), wherein the functional blocks include a post (1) to be turned by the rotary drive mechanism, a support shaft (4) supported on the post (1) for translatory movement, a translatory drive (7,6) for producing this movement, and an arm (3) disposed on the support shaft (4), characterised by the further provision of an upper base (9) located between the bed (2) and the post (1) and housing a brake mechanism (8) for the translatory drive (7,6). 2. An industrial robot according to claim 1, in which the translatory drive includes a motor (7) mounted on the post (1) for rotating a threaded shaft (61) so as to drive the support shaft (4), the motor and shaft being substantially enclosed within the post (1). 3. An industrial robot according to claim 1 or 2, wherein each engagement mechanism, e.g. between the upper base (9) and the post (1) and between the support shaft (4) and the arm (3), comprises a plurality of attachment screws (91). 4. An industrial robot according to claim 1, 2 or 3, wherein the arm module comprises first (3) and second (5) arms held in engagement with each other, the second arm (5) including an extensible and contractable arm.

Inventors: NIHEI, RYO, TORII, NOBUTOSHI
Applicants: FANUC LTD.
Application year: 1986
Main classification: B25J9
IPC codes: B25J9, B23Q37, B25J18