JPH0249865B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a polishing apparatus, and more particularly to a polishing apparatus that can teach the content of polishing work and perform the work according to the taught content.

(Prior Art) Conventionally, devices have been developed for automatically polishing curved surfaces with complicated shapes such as press molds, but these devices were not suitable for polishing objects with complicated shapes.

The inventor of the present application developed a polishing robot that performs automatic polishing in view of the existing situation, and filed a patent application for the same in Japanese Patent Application No. 1983-214661. This invention can automatically move the polishing tool in the required direction, and can efficiently polish curved surfaces with complex shapes.Moreover, it teaches the content of the polishing work and performs the work according to the taught content. It is a robot that can do this.

The present invention is a polishing robot that performs the swinging motion of an arm equipped with a tool (grindstone) by decelerating the rotational force of the drive shaft of a servo motor, and also has a memory device that allows teaching of work contents. During teaching, the servo motor is stopped and the arm is operated manually. At this time, if the speed reduction device connected to the servo motor is in operation, the speed reduction device will be rotated in the opposite direction, which requires a great deal of effort to drive the arm.

In other words, although the reduction gear is provided to reduce the rotational torque of the servo motor, it is difficult to drive the servo motor in the opposite direction via the reduction gear when teaching to move the arm manually. It becomes necessary to move the arm by force, which increases the burden on the operator. On the other hand, when moving the arm with such a strong operating force, it is difficult to move the tip of the arm to accurately follow minute irregularities, for example.In other words, the teaching operation becomes awkward and the arm There have been complaints that the accuracy with which the tip follows the surface of the object to be polished deteriorates, resulting in a decrease in teaching accuracy.

(Problems to be Solved by the Invention) An object of the present invention is to provide a polishing apparatus that can reduce the burden on the operator during teaching performed prior to polishing work, and at the same time can improve the teaching precision.

(Means for Solving the Problems) The present invention is provided between the base end of the arm and the drive shaft of the servo motor, and when the casing is fixed, a deceleration function is exerted, and when the casing is released, the deceleration function is released. A differential type speed reducer, a brake plate provided on the casing of the speed reducer and rotating integrally with the casing, a pair of brake plates that are in contact with the outer circumference of the brake plate, and when teaching, the brake body is connected to the brake plate. The present invention is characterized by being provided with a brake operation mechanism that moves the casing backwards to release the fixation of the casing, and fixes the casing by holding the brake body in pressure contact with a brake plate during polishing work.

(Function) When teaching, brake bodies 50, 5
1 is moved backward from the brake plates 23, 41 to release the casing of the speed reducer 22, the speed reduction function of the speed reducer is released. Then, the servo motor 25
Since the output shaft 26 and the arm are directly connected, the arms 8 and 10 can be rotated manually, and thereby the working procedure suitable for the shape of the object to be polished can be taught to the storage device.

On the other hand, during polishing work, the brake body 50,
51 is held in pressure contact with the brake plates 23, 41, the brake plates are fixed by the frictional force between the brake body and the brake plates, and the casing of the reducer 22 is also fixed. Then, since the speed reducer 22 exhibits a speed reduction function, the rotation of the servo motor 25 is reduced by the speed reducer and transmitted to the arms 8, 10, thereby making it possible to perform the polishing work.

(Example) FIGS. 1 and 2 show the entire polishing apparatus of the present invention. A base 1 is provided with a tool drive mechanism 2 and a table 3 on which a workpiece to be polished is placed. The tool drive mechanism 2 includes a case 5 held on a guide rod 4 of the base 1 so as to be movable up and down. 6 is a handle for raising and lowering the case. or,
The case 5 is provided with a first arm 8 that swings around a base shaft 7 and a second arm 10 connected to the tip of the first arm 8 by a pivot 9. A tool (grindstone) is attached to the arm 10 of
A holder 11 for attaching the is provided. Note that a downward biasing force is applied to the holder 11 by air pressure or the like, and the polishing operation is performed by operating the tool with a required pressing force.

Further, a rotating shaft 1 provided adjacent to the base shaft 7
A link 14 is connected by pins 15 and 16 between a third arm 13 that rotates about 2 and the second arm 10 for attaching a tool. The rotational movements of the first arm 8 and the third arm 13 are combined via the second arm 10 and the link 14,
This results in a planar movement of the tool attached to the holder 11.

Next, with reference to FIGS. 3 and 4, it will be explained that the mechanism for swinging the first arm 8 is built into the case 5. A rotary cylinder 21 protruding upward from the case 5 is rotatably inserted into a holding cylinder 20 provided in the case 5, and the first arm 8 is integrally attached to the upper end of the rotary cylinder 21. is connected to. Further, the lower end of the rotary cylinder 21 is connected to a differential mechanism type speed reducer 22 (eg, one commercially available under the trade name of Harmonic Drive).

Simply put, this speed reducer is composed of three members. Namely, there is a shaft member with an elliptical cam, a flexible gear that is made of an elastic metal body and has teeth carved on its outer periphery and is deformable and is connected to the cam of the shaft member, and a ring-shaped rigid body. and a casing having internal teeth on the inner periphery that mesh with the flexible gear. The casing has two more teeth than the flexible gear. As a result, when the shaft member is rotated with the casing fixed, the flexible gear rotates by an angle corresponding to the difference in the number of teeth in the casing, and a reduction ratio of 1/80 to 1/300 can be obtained. .

In the reduction gear 22 described above, the flexible gear is connected to the rotating cylinder 21, and the brake plate 23 is attached to the casing.
is fixed. A cylindrical portion of the brake plate 23 extending downward is rotatably supported within a holding cylinder 24 provided in the case 5. Also, the shaft member is the holding cylinder 2
4 is connected to an output shaft 26 of a servo motor 25 provided at the lower end of the motor. The servo motor 25 rotates in forward and reverse directions.
When the output shaft 26 is driven, the rotational force of the output shaft 26 is reduced by the reducer 22 and transmitted to the rotary tube 21, and the first arm 8 is rotated toward the base shaft 7 by the forward and reverse rotation of the rotary tube 21.
It is swayed around.

In order to reduce the rotational force of the output shaft 26 of the servo motor 25 and transmit it to the rotating tube 21 (first arm 8), it is necessary that the casing of the reducer 22 be fixed. For this reason, the present invention includes a mechanism for fixing the brake plate 23 provided integrally with the casing. Note that details regarding the brake plate will be described later.

The rotary cylinder 21 is provided with a toothed disc 27, which is connected to a rotary encoder 28 provided in the case 5 by a toothed belt 29, and is connected to the rotary encoder 28 provided in the case 5. While detecting the swing angle, the servo motor 2 is rotated within the set range.
5 is driven in forward and reverse directions to cause the first arm 8 to swing continuously.

The rotating mechanism of the polishing tool holder will be explained with reference to FIGS. 3 to 5. The base shaft 7 is supported by the base end of the first arm 8 and is provided with a toothed pulley 30 that rotates inside the arm, and furthermore, a motor 31 is provided on a portion protruding from the first arm 8. It is being Further, a pivot shaft 9 that connects the first arm 8 and the second arm 10 is provided with toothed pulleys 32 and 33 that rotate within each arm, and a holder provided at the tip of the second arm 10. 11
A toothed pulley 35 is also provided on the rotating shaft 34 . And these four toothed pulleys 30, 3
2, 33, and 35 all have the same diameter, and a toothed belt 36 is installed between the pulleys 30 and 32 in the first arm 8, and a toothed belt 36 is installed between the pulleys 33 and 35 in the second arm 10. A toothed belt 37 is attached between them, and the rotational force of the motor 31 is transmitted to the holder 11 to which the polishing tool is attached.

The rotating shaft 12 of the third arm 13 that reciprocates the link 14 is rotatably supported by the case 5, and the rotating shaft 12 is driven by a servo motor 40 provided below the case 5 via a speed reducer. Rotates in forward and reverse directions. Although this speed reducer is not shown, its structure is the same as that of the speed reducer provided in the rotating tube 21 described above, and a brake plate 41 integrated with the casing is provided in the same manner as described above. These two brake plates 23, 41 are mounted on the same plane.

Furthermore, the rotating shaft 12 has a toothed disk (not shown) that is the same as the toothed disk 27 provided on the rotating cylinder 21.
is provided, and this disc is connected to another rotary encoder 42 adjacent to the rotary encoder 28 by a toothed belt (not shown),
The servo motor 40 is controlled by detecting the swing angle of the third arm 13.

Next, the brake and brake operating mechanism will be explained with reference to FIGS. 6 to 8. The brake plate 2
3 and 41 are two brake bodies 50, 50, 51, 5 which are provided on the same plane in the case 5 and sandwich the side walls of each brake plate on the inside of the opposing surfaces.
1 is provided. The brake bodies 50, 50 for the brake plate 23 and the brake bodies 51, 51 for the brake plate 41 are both paired, and cylinders 52, 52, 53, 53 are provided on the same line.
is housed in. Further, the tips of the brake bodies 50 and 51 are formed into a planar arc shape, and this arc shape is in contact with the outer periphery of the brake plates 23 and 41. Further, the brake bodies 50, 51 are biased in the direction of pressing against the brake plates 23, 41 by a spring 55 attached between a plug body 54 provided at the cylinder opening, and a large force is exerted on the brake plates 23, 41. It gives power.

A gap is formed at the tip of the brake body 50, 50, 51, 51 described above, and an operation plate 56 for releasing (retreating) the brake body 50, 50, 51, 51 is provided within this gap. The operation plate 56 is rotatably supported by the case 5, and has a substantially rectangular shape near both ends, with one end located between the brake bodies 50, 50 and the other end between the brake bodies 51, 51. , the central part is connected to the air cylinder 5 via a connecting rod 59.
7 piston rod 58. The air cylinder 57 is fixed to the case 5, which is the body of the polishing device, and when these brake operating mechanisms apply the brakes to the brake plates 23 and 41 to exert a deceleration function, the casing of the reducer is moved to the polishing device. It will be fixed against.

When the operation plate 56 is vertical, the brake body 50,
50, 51, and 51 press the brake plates 23 and 41 against each other by the elasticity of the springs 55 and 55, and apply the brakes to fix the brake plates 23 and 41 to the case 5. When the piston rod 58 is moved forward, the operating plate 56 is tilted via the connecting rod 59, thereby causing all the brake bodies 50, 50, 51, 51 to be connected to the springs 55, 5.
5, the brake is released and the brake plates 23, 41 are separated from the case 5.

Next, the procedure of polishing work will be explained. This device is a polishing robot with a memory device that performs polishing work according to the procedure taught the work content.
The operator grips the holder 11 on the object to be polished fixed above and teaches the contents of the work to the storage device. First, prior to teaching, the air cylinder 57 is actuated to tilt the operation plate 56 via the piston rod 58 and the connecting rod 59, so that the brake body 50,
50, 51, and 51 are moved backward to release the brake, and the fixation of the brake plates 23, 41, that is, the casing of the speed reducer 22 is released. As described above, the release of the fixation of the casing of the reducer 22 means that the output shaft 26 of the servo motor and the first arm 8
Since the first arm 8 is directly connected to the rotary cylinder 21, the first arm 8 can be easily rotated manually. Thereafter, the storage device is taught a working procedure suitable for the shape of the object to be polished.

Next, when the teaching is finished, the air cylinder 57 is operated to return to the brake body 50, 50, 5.
1,51 with springs 55,55 to brake plates 23,4
1, thereby restoring the deceleration function of the speed reducer 22. Then, the rotational force of the servo motor 25 is reduced by the reducer 22, and the first arm 8 is rotated to perform the polishing work.

Note that the force that presses the tool against the workpiece is the holder 1.
The structure is such that the air is generated by an air cylinder installed at the top of the unit.

Further, in the present invention, the driving torque of the arm necessary for the polishing work is obtained by a reduction gear attached to the arm rotation part, but on the other hand, these mechanisms can also function as a safety device.

In other words, the driving torque transmitted to the arm is set according to the braking force applied from the brake body to the brake plate, and as this braking force, that is, the frictional force between the brake body and the brake plate, increases, the driving torque applied to the arm increases. growing. Also, if the external force acting on the arm is smaller than the driving torque, the arm will overcome this external force and rotate, but if the external force is larger than the driving torque, the brake mechanism will slip and the arm will stop, or You will be pushed back.

Therefore, by setting the braking force that influences the drive torque of the arm to an appropriate value (for example, 20 kg/cm ² ), a safe polishing robot that does not cause any damage to the operator can be obtained.

(Effects of the Invention) The present invention attaches a reducer to the rotating part of the arm on which the polishing tool is attached, and rotates the arm with a large torque to give the tool the moving force necessary for polishing. This is done by canceling the deceleration function of the reducer and avoiding reverse drive when the servo motor speeds up as the arm moves, so the arm can be rotated easily, making it easy to use during teaching. This makes it possible to reduce the burden on workers.

Further, since the arm rotates smoothly during teaching, the tip of the arm follows the surface of the object to be polished with high accuracy, and therefore, highly accurate teaching can be performed.

Furthermore, the speed reducer is configured as a differential type speed reducer, and the brake plate is brought into contact with and separated from the outer peripheral portion of the brake plate that rotates integrally with the casing of the speed reducer, thereby exerting or releasing the deceleration function of the speed reducer. Therefore, by setting the frictional force between the brake body and the brake plate to an appropriate value, the maximum torque applied to the reduction gear can be adjusted, and therefore the brake mechanism also functions as a safety device.

[Brief explanation of the drawing]

Figure 1 is a plan view of the entire assembly, Figure 2 is a front view, Figure 3 is a sectional view showing the swing mechanism of the first arm, and Figure 4 is a cross section showing the swing mechanism of the second arm. Figure 5 is a sectional view showing the attached state of the link that drives the second arm, Figure 6 is a plan view of the brake plate structure, Figure 7 is a front view thereof, and Figure 8 is Figure 6A- A sectional view. DESCRIPTION OF SYMBOLS 1... Base, 2... Tool drive mechanism, 3... Table, 4... Guide rod, 5... Case, 6... Handle, 7... Base shaft, 8... First arm, 9...
...Pivot, 10...Second arm, 11...Holder, 12...Rotation axis, 13...Third arm, 1
4... Link, 15, 16... Pin, 20... Holding tube, 21... Rotating tube, 22... Speed reducer, 23...
... Brake plate, 24 ... Holding cylinder, 25 ... Servo motor, 26 ... Output shaft, 27 ... Toothed disc, 2
8...Rotary encoder, 29...Toothed belt, 30...Toothed pulley, 31...Motor, 3
2, 33... Toothed pulley, 34... Rotating shaft, 35
...Toothed pulley, 36, 37...Toothed belt, 4
0... Servo motor, 41... Brake plate, 42
... Rotary encoder, 50, 51 ... Brake body, 52, 53 ... Cylinder, 54 ... Plug body, 55 ... Spring, 56 ... Operation plate, 57 ... Air cylinder, 58 ... Piston rod, 59 ... …
Connecting rod.

Claims (1)

[Claims] 1. An arm is equipped with a polishing tool attached to the tip and is rotatable around the base, and the tip of the arm is manually moved along the surface of the object to be polished to store the work procedure in a storage device. We will teach you how to
In a polishing device that performs polishing work according to a work procedure stored in the storage device, the arm is provided between the base end of the arm and the drive shaft of the servo motor, and when the casing is fixed, a deceleration function is exerted to reduce the speed of the casing. A differential speed reducer whose speed reduction function is released when the fixation is released; a brake plate provided on the casing of the speed reducer and rotated integrally with the casing;
A pair of brake bodies are brought into contact with the outer periphery of the brake plate. During teaching, the brake body is moved backward from the brake plate to release the fixation of the casing, and during polishing work, the brake body is held in pressure contact with the brake plate. A polishing device characterized in that a brake operation mechanism is provided for fixing the casing by rotating the casing.