JPH0224604Y2 - - Google Patents

Description

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

[Conventional technology and its problems]

Conventionally, this type of polishing robot
It is introduced in Publication No. 108262. That is, a first arm that swings around a shaft, a second arm that swings while being pivotally supported by the tip of the first arm, and a second arm that is suspended from the shaft of the tip of the second arm, and The first polishing tool is equipped with a polishing tool to which fine vibrations are applied.
The second arm is oscillated by a servo motor controlled by switching between forward and reverse directions within a set angle range, and positions the polishing tool.
A robot that uses this polishing tool to polish the surface of a mold is introduced.

However, in such a conventional example, both the first and second arms are controlled only to swing in a constant plane, so if the surface of the mold to be polished is a substantially constant plane, the polishing of that surface is not possible. It is possible, but
If there are large irregularities on the surface of the mold, polishing cannot be achieved only by horizontal rocking of the first and second arms. Therefore, in such a conventional example, the entire first and second arms are raised and lowered using a manual handle. Also, when polishing a mold with large irregularities, it is possible to tilt the table on which the mold is placed, but tilting the mold table requires that the mold of the object to be polished be large. This is not desirable and increases the cost of manufacturing the robot.

On the other hand, in a polishing robot that is equipped with multiple joints consisting of horizontally swinging first and second arms and has a polishing tool suspended from the tip of the first arm, the first and second arms are moved in the vertical direction. Polishing robots equipped with ball screws are known (for example,
(Refer to Japanese Patent Laid-Open No. 59-142062) However, if such a known polishing robot is applied to a simple robot that uses a direct teaching method that grips the vicinity of the polishing tool, the first arm, the second The large weight of the arms and their associated parts must be moved up and down manually, and it is particularly difficult to teach delicate up-and-down movements.

[Means to solve the problem]

Therefore, the present invention was devised to eliminate such conventional drawbacks, and its gist is:
horizontally swingable long first and second arms 4;
6, the tip of the first arm 4 and the second arm 6 are connected via a rotatable arm pin 10, and a polishing tool 25 that vibrates back and forth is suspended from the tip of the second arm 6. In the direct teaching playback type polishing robot, the first arm 4 is connected to a nut 13 of a ball screw 12 via a rotatable lever pin 11.
Both ends of the screw shaft 14, on which the screw shaft 14 is screwed, are supported by U-shaped brackets 17 that can swing horizontally.
and an encoder 16 are provided in direct connection with each other,
The slide member 1 with these first arm 4, second arm 6 and U-shaped bracket 17 attached,
Another encoder 35 and a servo motor 34 are used to move the polishing tool 25 up and down. The polishing robot is characterized in that it is provided with a load cell 36 for detecting the amount of the polishing material, and a signal from the load cell 36 is applied to a servo motor 34 for the slide member 1.

〔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 side view including a perspective view showing a part of the principle of the embodiment of the present invention, and FIG. 2 is a detailed view of section A in FIG. 1.

Two upper and lower brackets 2, 2 are protruded from the front surface of a slide member 1 that slides in the vertical direction on the side surface of a robot body 26, and a base shaft 3 is fixed to these protruding brackets 2. A first arm 4 is rotatably supported above the base shaft 3, and a first lever 5 is integrally provided at the base of the first arm 4 to protrude. In order to swing the second arm 6 below this base 3, the second
The lever 7 is rotatably supported. A connecting lever 8 is pivotally supported and protrudes from the tip of the second lever 7 via an upper second lever pin 18'.
The base of the second arm 6 is rotatably supported at the tip of the arm via a connecting pin 9. The second arm 6 is rotatably supported at the tip of the first arm 4 via an arm pin 10.

In the first illustration, the first and second levers 5 and 7 have the same length and the same protruding direction, but this is not necessarily the case. The tip of the first lever 5 and the nut 13 of the first high lead ball screw 12 are rotatably supported and connected via the first lever pin 11. This ball screw 1
A first servo motor 15 is attached to one end of the second screw shaft 14.
are connected via a clutch (not shown), and the first encoder 16 is connected to the other end. These servo motor 15 and encoder 16 are supported by a U-shaped bracket 17.
7 is pivotably supported with a protrusion 2' extending from the protrusion bracket 2 as a base.

The tip of the second lever 7 and the second lever pin 1
8, it is rotatably supported and connected to the nut 20 of the second high lead ball screw 19. 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
is supported by a U-shaped bracket 24, which is pivotally supported around the protruding portion 2' of the lower protruding bracket 2 as a base.

Note that 25 indicates a polishing tool suspended from the tip of the second arm 6, and the polishing tool 25 is slightly vibrated by a polishing tool motor 55 (see FIG. 2).

Since the first and second arms 4 and 6 are configured as described above, the operator stops the slide member 1 at an appropriate position, grips the vicinity of the polishing tool 25, and molds the polishing tool 25 into plastic. Mold B
(see FIG. 2) (this will be described later) and is taught via the encoders 16, 23. In this case, the first and/or second arms 4 and 6 swing as shown by arrows a and b, but for example, if the first arm 4 swings as shown by arrow a, the first lever 5 also swings at the same time. Since the bracket 17 swings as shown by the arrow b, the nut 13 is screwed forward while swinging slightly as shown by the arrow c, and the screw shaft 14 is rotated, and the first encoder 1
Rotate 6. In this case, since the ball screw 12 employs a high-lead type mechanism, the nut 13 is threaded with an extremely light operating force.

Next, turn on the memory playback switch and the first
and the second servo motors 15, 22, the first and second high lead ball screws 12, 19
rotate in forward and reverse directions simultaneously or individually. For example, when the screw shaft 14 of the first high-lead ball screw 12 rotates, the nut 13 spirals while the screw shaft 14 slightly swings as shown by 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. Next, when the screw shaft 21 of the second high lead ball screw 19 rotates, while giving a slight swing to the screw shaft 21 as indicated by the arrow f,
Natsu 20 spirals forward. As a result, the second lever 7
As a result, the second arm 6 swings via the connecting lever 8 to stop the polishing tool 25 at a predetermined position, and the slightly vibrating polishing tool 25 moves into the mold B (Fig. 2). (see).

Here, the slide member 1 slides up and down with respect to the robot body 26, and its structure is as follows. In other words, the robot body 26
Bearing brackets 27, 27 are provided protruding from the side surfaces of the bearing bracket 27, and a ball screw 29 is vertically installed on the bearing bracket 27 via a bearing 28. A nut 31 is screwed onto the screw shaft 30 of the ball screw 29, and the slide member 1 is fixed to the nut 31 via an L-shaped member 32. A joint 33 is attached to the upper end of this screw shaft 30.
A third servo motor 34 and a third encoder 35 are connected via the third servo motor 34 and the third encoder 35.

On the other hand, as shown in FIG. 2, a small compression/tension load cell 36 is fixed to the top surface of the tip of the second arm 6, and a suspension shaft 37 is attached to one end of the load cell 36 at a ball joint 38.
Hanging through. This hanging shaft 37 is connected to the bearing 40 and the bearing inner collar 39' within the outer bearing collar 39.
hold through. This bearing outer collar 39 is
It is fixed to the tip of arm 6. A timing belt pulley 41 is rotatably inserted in the middle of the hanging shaft 37, and the timing belt pulley 41 is vertically slidable and rotatable via an upper bolt 42 on the bearing inner collar 39'. Attach it to fix it. A flange 43 is attached to this pulley 41 via a lower bolt 44 so as to be vertically slidable and rotationally fixed. A timing belt 45 is wound around this timing belt pulley 41.

An L-shaped large bracket 46 is attached to the lower end of this hanging shaft 37.
is fixed with a nut 47, and a small L-shaped bracket 49 is attached to this large L-shaped bracket 46 with a bolt 48.

This L-shaped small bracket 49 has a stopper 5.
A first air cylinder 51 in which a cylinder 0 is provided so as to be freely retractable
and a slide unit 52 for vertical positioning built into the second air cylinder. This slide unit 52 is composed of a fixed part 53 and a movable part 54, and the fixed part 53 is connected to an L-shaped small bracket 49.
In addition, the movable part 54 includes a second air cylinder (not shown). A polishing tool motor 55 is placed and fixed above this movable part 54, and a grip cylinder 56 is suspended below. This polishing tool motor 55 suspends a slider eccentric wheel mechanism 58 such as a Scotch yoke via an intermediate shaft 57. The slider eccentric mechanism 58 includes an eccentric pin 59 that protrudes from the intermediate shaft 57 and is slightly eccentric from the rotation center of the polishing tool motor 55, and a groove 60 that allows the tip of the eccentric pin 59 to reciprocate in the horizontal direction. Slider 61
and a guide member 62 by which the slider 61 is guided in the horizontal direction. A polishing tool 25 is suspended from this slider 61. This guide member 62 is detachably fixed to the grip tube 56 with a bag nut 63. In addition, 64 is a notch for the balancer,
65 indicates a drive unit.

The vertical movement of this embodiment is as follows. Air is supplied to the first air cylinder 51 in a downward direction so that the stopper 50 protrudes downward. Air is applied to the movable part 54 of the slide unit 52 so that the movable part 54 comes into contact with the stopper 50.
Supply to the upward side. Therefore, the movable part 54 is located in the middle of the slide unit 52. In this state, the operator grips the grip cylinder 56,
A predetermined portion on mold B is taught. When the operator operates the grip cylinder 56 held in the vertical direction,
Since air is supplied downward to the first air cylinder 51 and air is supplied upward to the movable part 54, the operation can be performed in a so-called neutral state, so that the operation can be carried out easily. Therefore, the force due to the operation is applied to the slide unit 52, the small bracket 49,
It is transmitted to the load cell 36 via the large bracket 46 and hanging shaft 39. The load cell 36 sensitively detects this operating force, converts it into an electrical signal, and then issues a command to the third servo motor 34.
Of course, the operation of swinging the horizontal plane is performed in the first
Since both the second arms 4 and 6 have the high lead ball screws 12 and 19 interposed therebetween, this can be done easily.

Next, air is supplied to the first air cylinder 51 upward so that the stopper 50 is installed in the first air cylinder 51, and the movable part 5
When air is supplied to the downward side of the second air cylinder in the mold B, the polishing tool 25 is pressed against the surface of the mold B with a predetermined pressure and performs polishing by a regeneration operation. In this case, if the first or second arms 4, 6 move down to the mold surface B contrary to the teaching, the polishing tool 25
Since the stopper 50 is recessed instead of being pressed by the mold B, the movable part 54 escapes upward, thereby preventing polishing due to unnecessary pressure.

At this point, loosen the bolt 48 and move the L-shaped small bracket 49 around the bolt 48 as shown.
If it is rotated by 90 degrees and fastened again, the mounting direction of the polishing tool 25 will be perpendicular to the plane of the paper, and as a result,
The vertical surface of mold B can be polished. Also, Natsuto 47
By loosening the L-shaped large bracket 46, slightly rotating it around the suspension shaft 37, and re-fastening it, the polishing tool 25 is tilted, and the inclined surface of the mold B can be polished.

[Effect of idea]

According to the present invention, since the ball screw is interposed between the first arm, the servo motor that drives the first arm, and the encoder that detects the swinging of the first arm, the ball screw functions as a speed reducer. Although it is directly connected to the servo motor, no other reduction gear is required. Therefore, there is no locking action by the reducer (generally with a gear-type reducer, it is not possible to reversely drive from the output side, the reducer becomes a locking device), and the first arm is controlled by the servo motor. Direct teaching type playback type is used because driving the first arm and transmitting the movement to the encoder by the operator teaching the first arm in the opposite direction can be carried out smoothly in the same forward and reverse conditions. Suitable for polishing robots. Moreover, since there is no breakage that tends to occur with gear-type reducers, the grinding tool attached to the tip of the second arm can be regenerated and operated accurately, allowing the arm to be made longer and more compact. Therefore, it can also be applied to polishing large molds.

Since the first lever is connected to the lever pin attached to the nut of the ball screw, the structure is simple, and during teaching, the movement of the first lever is accurately transmitted to the encoder directly connected to the ball screw, making it possible to use the direct teaching method. This makes it suitable for playback type polishing robots.

Both ends of the screw shaft of the ball screw are supported by U-shaped brackets, and a servo motor with a clutch and an encoder are directly connected to each end, so the servo motor is directly connected to one end of the screw shaft, and the other Since the encoder is directly connected to the end, there is no difference in rotation between the servo motor and the encoder, and there is no need to provide a bracket for the servo motor or encoder. The bracket can be used as is, making the structure extremely simple, and the inertial mass can be reduced accordingly. Therefore, the operator's operating force is small, and in addition to the lightness of the ball screw, the capacity of the servo motor can be reduced, making it suitable for a playback type polishing robot that uses a direct teaching method.

A load cell is installed near the polishing tool, and this load cell is used to detect the vertical position when teaching the vertical positions of the first and second arms, and the first and second arms are directly controlled by the force of the operator. It does not move up and down, but instead uses the load cell's detection, so almost no operating force is required. Therefore, both the above-mentioned oscillation teaching and the up-and-down teaching by the load cell are particularly easy, making it suitable for a playback type polishing robot that uses a direct teaching method.

[Brief explanation of the drawing]

FIG. 1 is a partially perspective side view of an embodiment of the present invention, and FIG. 2 is a detailed view of section A in FIG. 4...first arm, 6...second arm, 25...
...polishing tool, 29...ball screw, 36...load cell.

Claims (1)

[Claims for Utility Model Registration] Consisting of long first and second arms 4 and 6 that can swing horizontally, an arm pin 10 that can rotate the tip of the first arm 4 and the second arm 6 is provided. In a direct teaching type playback type polishing robot in which a polishing tool 25 that vibrates reciprocatingly is suspended from the tip of the second arm 6, the first arm 4 can be rotated by a lever pin. 11
Connected to the nut 13 of the ball screw 12 via
Both ends of the screw shaft 14 to which the nut 13 is screwed,
Both ends are supported by horizontally swingable U-shaped brackets 17, and a servo motor 15 with a clutch and an encoder 16 are directly connected to each end, and these first arm 4, second arm 6, and U-shaped Slide member 1 equipped with shaped bracket 17
, the other encoder 35 and servo motor 34
A load cell 36 is provided near the tip of the second arm 6 to be used for teaching and to detect displacement when the polishing tool 25 is moved up and down by the operator. A polishing robot characterized in that: a polishing robot is provided, and a signal from the load cell 36 is applied to a servo motor 34 for the slide member 1.