JPS6213159B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" This invention relates to a robot arm for an industrial robot.

``Prior art'' Conventional general robot arms include a rotating support body,
The arm main body has one end supported by the rotary support and a mechanical hand etc. attached to the other end. The rotating support is powered by electric power, hydraulic pressure,
Connected directly to an actuator using pneumatic pressure or the like as a power source, or via an appropriate power transmission device,
A rotational motion is imparted, whereby the arm body also pivots about the axis of the rotary support. In addition, in a robot arm, depending on the work type, for example, when starting or stopping, the angular velocity related to the movement of the arm body,
There are places where the so-called operating speed must be temporarily increased. In such places, conventional robot arms use large actuators with high output.

``Problem to be solved by the invention'' Therefore, in conventional robot arms, the more temporary the need to increase the operating speed, the more economic waste it becomes to provide a large actuator. In addition, there are problems such as the installation location of the actuator and the complexity of the surrounding structure.

Therefore, an object of the present invention is to provide a new robot arm that eliminates these conventional problems.

"Means for Solving the Problem" According to the present invention, the robot arm has a hollow sealed structure in which the arm body of the conventional robot arm functions as a pneumatic accumulator, and air is supplied from an external air supply source into the arm body. Two nozzles are installed on the arm body with their tips facing both the forward and reverse rotation directions of the arm body, and a valve for opening and closing the nozzle is attached to each nozzle. The compressed air stored in the nozzle is selectively injected into the atmosphere from either one of the nozzles to apply rotational force to the arm body.

Other objects, features and advantages of the present invention will become apparent from the detailed description below, taken in conjunction with the accompanying drawings.

``Embodiment of the Invention'' FIGS. 1 and 2 of the drawings show an embodiment of a robot arm according to the present invention. The robot arm 1 in the illustrated embodiment, like the conventional one, includes a rotating support 3 connected to an electric or hydraulic actuator (not shown), and an arm body 2 supported by the rotating support 3. It consists of Although not shown, a mechanical hand or the like is attached to the tip of the arm body 2. As understood from FIG. 2, the arm body 2 has a monocot structure and a hollow sealed structure, and the arm body 2 itself functions as a pneumatic accumulator. Air can be supplied into the arm body 2 by, for example, providing an air supply port 8 on the lower surface of the arm body 2, and connecting it to an appropriate air supply port provided outside via a flexible air hose (not shown). This is done by connecting to a supply source. Alternatively, an air supply passage communicating with the inside of the arm body 2 may be formed in the rotary support 3, and this air supply passage may be connected to an external air supply source via a swivel joint. Various other means of connecting the air supply and an external air supply source may be envisaged. Furthermore, nozzles 4 and 5 are provided on both side surfaces of the arm body 2, respectively. Valves 6 and 7 are attached to each of the nozzles 4 and 5, and the valves 6 and 7 are operated by a control device external to the robot arm 1.
Compressed air stored in the arm body 2 can be selectively injected into the atmosphere from nozzles 4 and 5. A rotational force is applied to the arm body 2 by the injection of compressed air, and this rotational force can be increased as the distance between the mounting positions of the nozzles 4 and 5 and the rotation axis is increased.

Here, the reason for using nozzles 4 and 5 will be explained.

The momentum p obtained by the injection of compressed air is given by the equation p=mv, where m is the amount of air released per unit time and v is the velocity of the released air. That is, if a large amount of air is ejected at high speed per unit time, the momentum obtained by injection will increase. However, if the amount of air discharged per unit time is increased, the capacity of the air supply source needs to be increased, and the amount of air consumed becomes large, which becomes uneconomical. Therefore, we decided to use a nozzle to suppress the amount of air released per unit time and instead increase the speed of the air released. Also,
The nozzles 4 and 5 also have the effect of suppressing the injected air from interfering with the surrounding atmosphere and causing disasters.

The robot arm of the present invention constructed in this manner is driven by an accumulator during normal use. In addition, for example, when the arm body 2 is rotated clockwise (arrow 9 in the figure) at the time of starting, and the operating speed needs to be increased compared to normal use, the valve 6 may be operated. A nozzle 4 is opened and compressed air is injected from the nozzle 4 to accelerate the movement of the arm body 2. On the other hand, if the arm body 2 that is rotating clockwise is to be stopped more abruptly than during normal use, compressed air may be injected from the other nozzle 5. When increasing the operating speed when starting or stopping the arm body 2 when turning in the counterclockwise direction (arrow 10 in the figure), or in other cases, the injection force of the compressed air from the nozzles 4 and 5 should be similarly increased. Make use of it.

"Effects of the Invention" As described above, according to the present invention, the arm body of the robot arm is structured to function as a pneumatic accumulator, and the compressed air stored in the arm body is directed in both the forward and reverse rotation directions of the arm body. By enabling selective injection, when it becomes necessary to increase the operating speed of the robot arm, the injection force can be used as auxiliary power for the robot arm. Therefore, the actuator to be installed in this robot arm can be small-sized and has an output necessary for steady operation, which is economical and reduces problems such as installation location. Furthermore, since air pressure is applied inside the arm body, the rigidity of the arm body can be increased. Furthermore,
If there is a peripheral device for the robot arm that uses air pressure, especially if that peripheral device requires a large amount of air, the compressed air inside the arm body can be used, and it can be used for large compressors or accumulators. In some cases, it may not be necessary to provide
Furthermore, if an actuator such as a mechanical hand is mounted within the arm body, this actuator can be air-cooled by compressed air within the arm body. In this way, the robot arm of the present invention has various effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view schematically showing an embodiment of a robot arm according to the present invention, and FIG. 2 is a sectional view showing the structure of the arm body of the robot arm shown in FIG. In the figure, 1: robot arm, 2: arm body, 3: rotating support, 4, 5: nozzle, 6,
7: Valve, 8: Air supply port.

Claims (1)

[Claims] 1. A robot formed of a rotary support body connected directly or via an appropriate power transmission device to an actuator powered by electric power, hydraulic pressure, pneumatic pressure, etc., and an arm body supported by the rotary support body. In the arm, the arm body has a hollow sealed structure so as to function as a pneumatic accumulator,
Air is supplied into the arm body from an external air supply source, and two nozzles are provided on the arm body with their tips facing both forward and reverse rotation directions of the arm body, and each nozzle is used for opening and closing the nozzle. A valve is installed, and by operating the valve, the compressed air stored in the arm body is selectively injected into the atmosphere from either one of the nozzles, thereby imparting rotational force to the arm body. Features a robot arm.