JPH0232377Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polishing robot that polishes the surface of a mold for plastic molding, etc.

[Conventional technology and its issues]

Conventionally, this type of polishing robot
It is introduced in Publication No. 108262. That is, in a polishing robot equipped with two joints, a first arm that swings around an axis, a second arm that is pivotally supported by the tip of the first arm and swings, and a tip of the second arm that swings around an axis. The first and second arms are oscillated by a servo motor that is controlled by switching between forward and reverse directions within a set angle range, A polishing robot has been introduced that reciprocates through a required angular range to determine a predetermined position and polishes the surface of a mold with a polishing tool.

However, in such a conventional example, the small servo motor that swings the first and second arms is
Since a certain amount of torque is required for swinging the arms, a gear-shaped reducer is inevitably involved. Therefore, when long arms are used, the backlash of each arm is caused by the backlash of this reducer. This caused a backlash of up to several millimeters at the tip, which caused problems in which polishing could not be performed accurately when the robot was regenerated.

[Means to solve the problem]

The present invention has been devised to eliminate the drawbacks of the conventional example, and its gist is that the first and second arms 4 and 6 are horizontally swingable and that the first and second arms 4 and 6 are horizontally swingable. A polishing tool 2 in which the tip of an arm 4 and a second arm 6 are connected via a rotatable arm pin 10, and the tip of the second arm 6 vibrates slightly.
5, the first arm 4 is connected to a ball screw 12 via a rotatable lever pin 11.
A screw shaft 14 is connected to a nut 13, and both ends of the screw shaft 14, into which the nut 13 is screwed, are supported at both ends by U-shaped brackets 17 that can swing horizontally. A servo motor 15 with a clutch, and an encoder 16 for detecting movement when gripping and teaching the vicinity of the polishing tool 25 and for controlling the servo motor 15 are each directly connected to each other. A mold polishing robot is characterized by:

〔Example〕

Hereinafter, the structure of the present invention will be described in detail based on embodiments shown in the accompanying drawings.

FIG. 1 is a perspective view showing the principle of an embodiment of the present invention;
FIG. 2 is a plan view of the same embodiment, and FIG. 3 is a side view of FIG. 2.

In FIG. 1, two upper and lower brackets 2, 2 are provided projecting from the front surface of a slide member 1 that slides up and down on the side surface of the robot body, and a base shaft 3 is fixed to these brackets 2 in the vertical direction. A first arm 4 is rotatably supported above this base shaft 3, and a first arm 4 is pivotably supported above this base shaft 3.
A first lever 5 is integrally provided at the base of the arm 4 and protrudes. A second lever 7 for swinging the second arm 6 is rotatably supported below the base shaft 3. A connecting lever 8 is rotatably pivotally attached to and protrudes from the tip of the second lever 7 via an upper second lever pin 18'. The base of the arm 6 is rotatably supported. The tip of the first arm 4 is connected to the second arm 6 via a rotatable arm pin 10.

Although these first and second levers 5 and 7 are shown to have the same length and the same protruding direction, this is not necessarily the case. A nut 13 of a first high lead ball screw 12 is connected to the tip of the first lever 5 via a rotatable first lever pin 11. A first servo motor 15 is connected to one end of the screw shaft 14 of this ball screw 12 via a clutch (not shown), and a first servo motor 15 is connected to the other end of the screw shaft 14 of the ball screw 12.
An encoder 16 is connected. These servo motor 15 and encoder 16 are supported by a U-shaped bracket 17.
7 is pivotably supported with an extension 2' extending from the upper protruding bracket 2 as a base.

A nut 20 of a second high lead ball screw 19 is connected to the tip of the second lever 7 via a rotatable second lever pin 18. A second servo motor 22 is connected to one end of the screw shaft 21 of the ball screw 19 via a clutch (not shown), and a second encoder 23 is connected to the other end. These servo motor 22 and encoder 23 are supported by a U-shaped bracket 24, and this U-shaped bracket 24 is connected to the lower protruding bracket 2.
The extension part 2' is pivotably supported as a base.

Note that 25 indicates a polishing tool suspended from the tip of the second arm 6, and this polishing tool 25 is given reciprocating fine vibration by a separate motor (39 in FIG. 3).

Next, to describe its operation, the slide member 1 is stopped at an appropriate position, and each servo motor 15, 2
2, the operator grasps the vicinity of the polishing tool 25, and slides the polishing tool 25 over the entire surface of a plastic mold (not shown) while pressing it relatively lightly. 16, 23
Teach via. In this case, the first and/or second arms 4, 6 are moved by arrows a and d by the operator.
For example, if the first arm 4 is swung as shown in arrow a, the first lever 5 will also be swung as shown in arrow b, so that the U-shaped bracket 17 will also be swung. Slightly swing as shown by arrow C, screw the nut 13 onto the screw shaft 14, and screw the nut 13 onto the screw shaft 14.
The first encoder 16 is activated by the rotation of . In this case, since the ball screw 12 uses a high lead type mechanism, the nut 1 can be tightened with extremely light operating force.
3 can be spiraled.

Next, when each clutch is engaged and the memory replay switch is engaged, the first and second servo motors 1
5 and 22, the first and second high lead ball screws 12 and 19 rotate simultaneously or individually, with forward and reverse rotation. For example, if the screw shaft 14 of the first high lead ball screw 12 rotates,
The nut 13 screws forward while causing the screw shaft 14 to swing slightly as indicated by the arrow C. As a result, the first lever 5 swings, whereby the first arm 4 swings in the direction of arrow a and stops at a predetermined position. Then the second
When the screw shaft 21 of the high lead ball screw 19 rotates, the nut 20 spirals while the screw shaft 21 slightly swings as indicated by the arrow f. As a result, the second
The lever 7 swings, whereby the second arm 6 swings via the connecting lever 8, positioning the polishing tool 25 at a predetermined position, and the polishing tool 2 vibrates back and forth slightly.
Polish the surface of the mold in step 5.

Next, an outline of a robot embodying this embodiment will be explained. This is shown in a plan view in FIG. 2 and a side view in FIG. 3, and the same parts as those explained in FIG.

The slide member 1 is provided on the side surface of the robot body 26 so as to be slidable up and down, and the slide member 1 is moved up and down by a third ball screw (not shown) built into the bellows 27. A third servo motor 28 and a third encoder 2 are connected to the upper end of this third ball screw.
9 are arranged in a row. An air cylinder 28' is attached to the slide member 1 for balancing the first and second arms 4, 6. The robot body 26 is placed on a base 29.

Timing belt pulleys 30 and 31 are provided at both ends of the upper surface of the first arm 4, and a timing belt 32 is wound around these pulleys 30 and 31. One pulley 30 is fixed to the fixed base shaft 3 so as not to rotate, and the other pulley 31 is fixed to the first
It is rotatable relative to the arm 4, and is also rotatably fitted to the arm pin 10. Therefore, even if the first arm 4 swings, the fixed point of the pulley 31 always faces in a fixed direction.

Timing belt pulleys 33 and 34 are provided at both ends of the lower surface of the second arm 6, and a timing belt 35 is wound around these pulleys 33 and 34. One pulley 33 is connected to the arm pin 10.
The other pulley 34 is fixed to a suspension shaft 35 for the polishing tool 25. Therefore, even if the second arm 6 swings, the polishing tool 25
The mounting method is always the same.

In addition, 36 is a load cell, 37 is a tool bracket, 38 is a slide unit, 39 is a polishing tool motor, 40 is an encoder cover, 41 is a transmission case, 42 is a polishing zone, and 43 is a first and second high lead. The bellows of the ball screws 12 and 19 are shown.

In the polishing robot of this embodiment, the mold to be polished is placed on an appropriate floor on the side of the base 29, and the mold is polished by forced regeneration as explained in FIG.

[Effect of idea]

According to the present invention, a ball screw is installed between the first arm, the servo motor that drives the first arm, and the encoder that detects the swing of the first arm and controls the servo motor during teaching. Since the ball screw is interposed, the ball screw functions as a reduction gear for the servo motor, and although it is directly connected to the servo motor, no other reduction gear is required. Therefore, omitting the reducer not only simplifies the structure, but also reduces the locking effect of the reducer (generally, gear-shaped reducers cannot be driven in the opposite direction from the output side, and the reducer becomes a locking device. ), the first arm can be driven by a servo motor, and vice versa, the movement of the first arm can be transmitted to the encoder by being taught by the operator.
Since both forward and reverse operations are performed smoothly under the same conditions, it is suitable for a direct teaching type playback type mold polishing robot. Moreover, since there is no bump crash that tends to occur with gear-shaped reducers, the operation by regenerating the polishing tool attached to the tip of the second arm is performed accurately.
The arm can be made long, so
It can also be applied to polishing large molds.

The lever pin attached to the nut of the ball screw connects the ball screw and the first lever, which simplifies the structure and makes it easier to teach.
The movement of the first lever is not only accurately transmitted to the encoder directly connected to the ball screw, but also the teaching is carried out easily, making it suitable for a breakback type mold polishing robot that uses a direct teaching method.

The screw shaft of the ball screw is supported at both ends by U-shaped brackets, and a servo motor with a clutch and an encoder are attached to each end.
Because they are directly connected, the servo motor is directly connected to one end of the screw shaft, and the encoder is directly connected to the other end. There is no need to provide a bracket or support device for the encoder or the encoder, and the U-shaped bracket for supporting the ball screw can be used as is, resulting in an extremely simple structure, and in addition to the above-mentioned simple structure, the inertial mass can be reduced accordingly. Therefore,
Since the force required by the operator is small during teaching, in combination with the lightness of the ball screw, it is not only suitable for playback-type mold polishing robots that use the direct teaching method, but also reduces the capacity of the servo motor for regeneration operation. The size of the horizontally swinging member can be further reduced.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the principle of an embodiment of the present invention, FIG. 2 is a plan view of the same embodiment, and FIG. 3 is a side view of FIG. 2. 4...first arm, 6...second arm, 12...
...First high lead ball screw, 13... Nut, 15... First servo motor, 16... First encoder, 19... Second high lead ball screw, 20... Nut, 22... Second servo motor , 23...second encoder, 25...polishing tool.

Claims (1)

[Claims for Utility Model Registration] The first arm 4 and the second arm 6 are horizontally swingable, and the tip of the first arm 4 and the second arm 6 are connected via a rotatable arm pin 10. In a direct teaching type playback type polishing robot in which a polishing tool 25 that vibrates slightly is suspended from the tip of the second arm 6, the first arm 4 is connected to a rotatable lever pin 1.
The screw shaft 14 is connected to the nut 13 of the ball screw 12 through the screw shaft 1, and both ends of the screw shaft 14, into which the nut 13 is screwed, are supported at both ends by U-shaped brackets 17 that can swing horizontally. Servo motor 1 with clutch to drive 1 arm
5, and an encoder 16 for detecting the movement when gripping and teaching the vicinity of the polishing tool 25 and controlling the servo motor 15;
A mold polishing robot characterized by being directly connected to each other.