JPS6325107Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an arm mechanism having one or more joints, and in particular, a motor for rotating each arm is provided at the base end of the arm mechanism, and each arm is rotated by the rotational force of this motor. The present invention relates to an arm mechanism that moves each arm by driving a worm gear mechanism provided at the joint.

2. Description of the Related Art Some robots and plotters, which are one type of automatic drawing device, use an arm mechanism to perform necessary operations. FIG. 1 is a partially cutaway side view showing an example of an arm mechanism used in such a device. As shown in this figure, in this arm mechanism, the arm mechanism base 1
A first pulse motor 2 fixed to the rotating plate 3 rotates a first arm 4 provided on the rotary plate 3, and a second pulse motor 2 provided at the tip of the first arm 4 rotates the first arm 4 provided on the rotating plate 3. By rotating a second arm 6 provided on a rotary plate 7 by a motor 5, a working part 8 at the tip of the arm mechanism is caused to trace a desired trajectory.

By the way, in such an arm mechanism, since the second pulse motor 5 is provided at the second joint 9, the inertial load of the first pulse motor 2 is large by the mass of the second pulse motor 5. Not only is it impossible to move the working part 8 at the tip of the mechanism at high speed and high acceleration, but the first joint 10 and the first arm 4 must be made stronger to support the weight of the entire arm mechanism. I can't.

In view of the above points, this idea reduces the mass of the joints in the arm mechanism, allowing the distal end to move with high speed, high acceleration, and precision, while reducing the load on the proximal end. The purpose is to provide an arm mechanism that can.

Means for achieving the above object will be explained with reference to FIGS. 2 and 3, which correspond to embodiments.

That is, this invention provides a first
a first worm gear mechanism 15 consisting of a worm 16 and a worm wheel 17 that are pivotally supported on a part of the support base 13 and driven by the first motor 18; and a shaft of the worm wheel 17. A rotary plate 19 is provided to be able to freely rotate integrally therewith, a second motor 21 is provided on a mounting base of the rotary plate 19, one end is fixed to the rotary plate 19, and a gear box 23 is attached to the other end. a first arm 22 fixedly supported; a second worm gear mechanism 25 comprising a worm 26 and a worm wheel 27 pivotally supported in the gear box 23; and a worm 26 forming the second worm gear mechanism 25. and a drive shaft 28 that coaxially connects the shaft of the second motor 21 with the drive shaft of the second motor 21, and a worm wheel 27 forming the second worm gear mechanism 25. The arm mechanism is characterized by comprising: a U-shaped rotating plate 29; and a second arm 30 attached to a side portion of the intermediate side of the rotating plate 29.

This invention will be explained below with reference to an embodiment shown in the drawings.

FIG. 2 is a partially cutaway plan view showing an embodiment of the arm mechanism according to this invention, and FIG. 3 is a partially cutaway side view of this embodiment. In these figures, reference numeral 11 denotes an arm mechanism base to which an arm mechanism 12 is attached, and a support base 13 is fixed to this arm mechanism base 11. The support base 13 is composed of a hollow cylindrical member 14, and a first worm gear mechanism 15 is housed within the hollow cylindrical member 14. The first worm gear mechanism 15 is composed of a worm 16 and a worm wheel 17 that meshes with the worm 16, and the worm 16 is connected to the hollow cylindrical member 14.
The upper end of the shaft of the worm wheel 17 passes through the upper surface of the hollow cylindrical member 14 and is connected to the rotating plate 19. The rotating plate 19 is
A second pulse motor 21 is provided on a motor mount 20 formed on the upper surface of the rotary plate 19, and a second pulse motor 21 is installed on the side of the rotary plate 19. is provided with a first arm 22, and a gear box 23 is provided at the tip of this first arm 22. The gear box 23 is composed of a hollow cylindrical member 24, and a second worm gear mechanism 25 is housed within the hollow cylindrical member 24. Similarly to the first worm gear mechanism 15, the second worm gear mechanism 25 also includes a worm 26 and a worm wheel 27 that meshes with the worm 26.
The worm 26 is connected to the shaft of the second pulse motor 21 via a drive shaft (transmission mechanism) 28, and each shaft end of the worm wheel 27 is connected to the hollow cylindrical member 24. It protrudes from the upper and lower surfaces of and is connected to the rotating plate 29. The rotating plate 29 is formed in a U-shape, and a second arm 3 is attached to the side of the rotating plate 29.
0 is attached, and this second arm 3
A working part 31 is provided at the tip of the 0.

Next, a circuit for controlling the operation of this embodiment will be explained.

FIG. 4 is a block diagram showing an example of the circuit configuration of this arm mechanism. In this figure, 32 is an input port that receives control data (arm drive data) from a central processing unit (not shown), and the control data taken in by this input port 32 is supplied to an input switching circuit 33. Ru. The input switching circuit 33 selects and takes in either the output of the input port 32 or the control data output from the operation panel 34, and the output of this input switching circuit 33 is supplied to a data conversion circuit 35. . The data conversion circuit 35 is a microprocessor, RAM (random access memory), and ROM (read-on memory).
The X-axis data and Y-axis data from the input switching circuit 33 are converted into two polar coordinate data and supplied to the controller 36. The controller 36 drives the first pulse motor 18 and the second pulse motor 21 based on the output of the data conversion circuit 35, and outputs pulses according to the output of the data conversion circuit 35 to drive the first pulse motor 18 and the second pulse motor 21. , second pulse motor 18,2
Supply to 1.

Next, the operation of this embodiment having the above configuration will be explained.

First, when controlling the arm mechanism 12 based on arm drive data from the outside, the input port 32 is selected by the input switching circuit 33. Therefore, in this case, the input port 32,
The data conversion circuit 3 sequentially passes through the input switching circuit 33.
Arm drive data from the outside is supplied to 5, which is converted into two corresponding polar coordinate data and then supplied to the controller 36. As a result, the controller 36 controls the first pulse motor 18
is energized to drive the first worm gear mechanism 15 to rotate the first arm 22, and energize the second pulse motor 21 to transmit its rotational force to the second worm gear via the drive shaft 28. The second arm 30 is rotated by supplying it to the mechanism 25, and the working part 31 at the tip of the arm mechanism 12 is moved.

Furthermore, the arm mechanism 12 is controlled by the operation panel 34.
When controlling the input switching circuit 33, first, the input switching circuit 33 is switched, and arm drive data input from the operation panel 34 is supplied to the data conversion circuit 35 via the input switching circuit 33. As a result, two pieces of polar coordinate data are output from the data conversion circuit 35, and each arm 22, 30 of the arm mechanism 12 rotates according to these two pieces of polar coordinate data.

In this way, in this arm mechanism, data indicating the movement of the working section 31 in the X-axis direction (X-axis data) and data indicating the movement of this working section 31 in the Y-axis direction (Y-axis data) must be input. Well, this is 2
Each pulse motor is converted into one polar coordinate data.
Since the arms 8 and 21 are driven, this arm mechanism can be directly controlled by control data output from an external central processing unit. In this case, the data conversion circuit 35 can be omitted when the central processing unit directly outputs polar coordinate data.

Further, in the embodiment described above, the pulse motors 18 and 21 are used as the drive source for the arm mechanism 12, but it is also possible to configure the pulse motors 18 and 21 with an encoder and a servo motor controlled by the output of this encoder. You can get the same effect as in the case.

As explained above, according to the arm mechanism having two joints according to this invention, the arm mechanism is driven by the first motor 18 provided on a part of the support base 13, and the shaft is attached to a part of the support base 13. A rotary plate 19 is provided on the worm wheel 17 axis of the supported first worm gear mechanism 15 so as to be freely rotatable.
Since the second motor 21 for driving the second worm gear mechanism 25 is provided on the mounting base 9,
The first and second motors 18 and 21 are mounted on the base of the arm mechanism to reduce the mass of the second joint portion having the second worm gear mechanism 25, and to drive the tip side of the arm mechanism at high speed and high speed. It is possible to move the arm mechanism with precision, and the drive section by the first and second motors 18 and 21 can be formed compactly, so that the entire arm mechanism can be formed compactly.

In addition, the gear box 23 that houses the second worm gear mechanism 25 constituting the second joint has a rotary plate 19 that is rotationally driven by the first worm gear mechanism 25, and a first arm 22 and a drive shaft 28.
Since the rotating plate 1 is supported by two rods, the support is strong and the operation is stable.
Since the second motor 21 is mounted on the top of the motor 9, the gearbox 23 and the rotating plate 19 are balanced in terms of weight, and the rotating plate 19 does not tilt, making its operation more stable and facilitating positioning. Improves accuracy.

Furthermore, the second arm 30 as a working part is
Since it is attached to the side of the U-shaped rotating plate 29 whose both ends are fixed to the vertically protruding shaft of the worm wheel 27 forming the second worm gear mechanism 25, it is possible to work with high precision in a stable condition. There is an effect that can be achieved by the second arm 30.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a conventional arm mechanism, FIG. 2 is a partially cutaway plan view showing an embodiment of the arm mechanism according to this invention, and FIG. 3 is a partially cutaway side view of the same embodiment. FIG. 4 is a block diagram showing an example of the circuit configuration of the same embodiment. 15... Worm gear mechanism as a first reduction mechanism, 18... Pulse motor as a first motor, 21... Pulse motor as a second motor, 22... First arm, 25... Second 28... a drive shaft as a transmission mechanism, 30... a second arm.

Claims (1)

[Claims for Utility Model Registration] Support stand 13 fixed on arm mechanism base 11
a first worm gear mechanism 15 consisting of a worm 16 and a worm wheel 17 that are pivotally supported on a part of the support base 13 and driven by the first motor 18; a rotary plate 19 provided on the shaft of the worm wheel 17 so as to be able to rotate integrally with the worm wheel; a second motor 21 provided on a mounting base of the rotary plate 19; one end fixed to the rotary plate 19. a first arm 22 with a gear box 23 fixed and supported at the other end; a second worm gear mechanism 25 consisting of a worm 26 and a worm wheel 27 that are pivotally supported within the gear box 23; a drive shaft 28 that coaxially connects the shaft of a worm 26 forming the worm gear mechanism 25 and the drive shaft of the second motor 21; and a drive shaft 28 that protrudes above and below the worm wheel 27 forming the second worm gear mechanism 25. An arm mechanism comprising: a U-shaped rotating plate 29 whose both ends are fixed to a shaft; and a second arm 30 attached to a side of the middle side of the rotating plate 29.