JP2000308984A - Scalar arm and carrier device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a direction of a revolving table by providing a driving source on an arm at a position not to be overlapped with the revolving table of a scalar arm in the vertical direction and driving a transmission means independently from revolution of a head end side arm. SOLUTION: A second arm 6 revolves by-2θ and a revolving table 8 revolves by 9 when a first arm 4 revolves by 9 in the case when a servo motor 40 is stopped. Hereby, a pulley 42 further revolves, consequently a pulley 46 further revolves and it is possible to optionally change a direction of the revolving table 8 when the servo motor 40 is driven. It is possible to both simultaneously and separately carry out driving (revolution of the revolving table 8) of the servo motor 40 and driving (extension and contraction work of arms 4, 6) of the servo motor 20. Consequently, it is possible to optionally change the direction of the revolving table 8 to an optional direction by adding the servo motor 40 to the scalar arm in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scalar arm and a transfer device using the scalar arm.

[0002]

2. Description of the Related Art A scalar arm is used as a transfer mechanism in a transfer device such as an automatic guided vehicle or a crane. FIG.
Shows a conventional scalar arm, 4 is a first arm,
Reference numeral 6 denotes a second arm, and reference numeral 8 denotes a turning table. This scalar arm is a three-joint transfer device provided with three joints at a base of a first arm, a connecting portion between the first arm and the second arm, and a base of a table. These joints are driven by one servomotor, and when the first arm 4 rotates by an angle θ, the second arm 6 rotates in the opposite direction by 2θ, and the table 8 rotates by θ in the same direction as the first arm 4. I do. As a result, the turning table 8 always faces in the same direction, and the movement of the arms 4 and 6 causes the turning table 8 to linearly move while maintaining the same posture.

[0003] In order to show the attitude of the turning table 8,
When the side surface 64 is indicated by oblique lines, even if the scalar arm moves, the side surface 64 always faces the same direction, and the direction of the mounted article does not change. This is an advantage, but also a disadvantage. For example, consider a case where a directional article such as a cassette containing work-in-progress is stored in an automatic warehouse. Automatic warehouses have tracked trucks, automated guided vehicles,
It is assumed that various transport devices such as overhead traveling vehicles are connected, and articles are carried in and out of these devices. A scalar arm is mounted on a stacker crane or the like in an automatic warehouse to transfer articles. If all the transporting devices carry articles in and out of the same direction into and out of the automatic warehouse, using a scalar arm has the advantage that the direction of the articles does not change. However, when the direction of the articles is different between the transfer devices, the direction of the articles must be changed between the time of loading and the time of unloading, and a conveyor equipped with a turning table is provided at an entrance / exit station of an automatic warehouse, and the articles are provided. It is necessary to change the direction.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to make the direction of a rotary table of a scalar arm variable and to realize this by a compact mechanism.
An additional object of the present invention is to connect the drive source and the transmission means with a compact mechanism using a joint between the first arm and the second arm in the scalar arm. . In particular, the object of the invention of claim 3 is to allow the transfer device of the automatic warehouse to freely change the direction of the article and to reverse the direction of the article when carrying out directional articles into and out of the automatic warehouse. An object of the present invention is to make a conveyor or the like having a turning table unnecessary.

[0005]

According to the present invention, a second arm is rotatably supported at a tip of a first arm, and a swivel table is rotatably supported at a tip of a second arm. In a scalar arm provided with transmission means for linking rotation of the turntable in the opposite direction in the second arm,
A drive source is provided for the first or second arm at a position not overlapping the turning table in the vertical direction, and the transmission means is driven independently of rotation of the second arm. (Claim 1).

[0006] Preferably, a shaft is provided at a joint between the first arm and the second arm, and the drive source and the transmission means are connected to the shaft.

[0007] Preferably, the scalar arm is mounted on a transfer device such as a crane for an automatic warehouse, and particularly preferably mounted on a crane of an automatic warehouse for a clean room.

[0008]

According to the first aspect of the present invention, the rotary table can be rotated in an arbitrary direction independently of the rotation of the second arm by using the existing transmission means of the scalar arm. The drive source is provided on the first or second arm at a position that does not vertically overlap the swivel table, so that the thickness of the scalar arm near the swivel table does not increase. In addition, at a position away from the turntable, there is no interference with other components from the beginning, and if the driving source can be accommodated in the arm, the external size of the scalar arm will not increase substantially, and even if it protrudes from the arm, it will not interfere with surrounding objects.

According to the second aspect of the present invention, if the drive source and the transmission means are connected by using the shaft between the first arm and the second arm, and the shaft is rotated by the drive source, the rotation of the second arm is achieved. The turning table can be rotated independently of the movement, and if the drive source is not operated, it operates as a normal scalar arm.
The swivel table rotates in a direction opposite to the rotation of the arm.

[0010] According to a third aspect of the present invention, the scalar arm of the first or second aspect is mounted, so that the direction of the article can be changed by the automatic warehouse. Therefore, there is no need to separately provide a conveyor or the like for changing the direction of an article in an automatic warehouse that handles articles having directivity. Since the drive source of the scalar arm can be easily sealed in the arm or covered with a cover, it does not cause dust even when used in a clean room or the like.

[0011]

1 to 3 show an embodiment. FIG. 1 shows the structure of the scalar arm 2. Reference numeral 4 denotes a lower first arm.
6 is an upper second arm, 8 is a swivel table rotatably supported on the tip of the second arm 6, and 9 is a base for fixing the scalar arm 2 to a crane or the like. 1
Numeral 0 denotes a harmonic drive that is a joint between the base 9 of the scalar arm 2 and the first arm 4. Explaining the structure of the harmonic drive 10, reference numeral 12 denotes a pulley connected to an input shaft, and reference numeral 14 denotes a housing, which is fixed to the base 9. A pulley 16 is fixed to the base 9 via a housing 14. Reference numeral 18 denotes an output shaft coupled to the first arm 4, which is connected to the input shaft 12 and rotates, and the input shaft 12 is rotated by the servomotor 20. 22 is
This is a bearing between the first arm 6 and the base 9. Among the harmonic drives 10, those fixed to the base 9 are a housing 14, a pulley 16 and an input shaft 1
Coupled to 2 is an output shaft 18.

A timing belt 24 as a transmission means is stretched over the pulley 16.
This is a harmonic drive between the arm 6. Reference numeral 28 denotes a housing of the harmonic drive 26, which is fixed to the first arm 4. 30 is a harmonic drive 26
A pulley coupled to the input shaft of the
Is a shaft connected to the output shaft 32. A pulley 36 is rotatable with respect to the output shaft 32.
Is fixed to the pulley 36. Reference numeral 40 denotes a servo motor for driving the harmonic drive 26, and reference numeral 42 denotes a pulley fixed to the shaft 34. In the harmonic drive 26, the housing 28 is fixed to the first arm 4,
The pulley 36 is fixed to the second arm 6, and the input shaft and the pulley 30, the output shaft 32, the shaft 34, and the pulley 42 are connected. Reference numeral 38 denotes a bearing between the second arm 6 and the first arm 4.

Reference numeral 44 denotes a timing belt, 46 denotes a pulley fixed to the turning table 8, and 47 denotes a bearing between the turning table 8 and the second arm 6. The difference between the scalar arm 2 of the embodiment and the conventional example is that the input shaft of the harmonic drive 26 is not fixed to the first arm 4 as in the conventional example, but is connected to the pulley 30 and rotated by the servo motor 40. The point is to get it. Further, the purpose of the servo motor 40 may be that the pulley 42 is ultimately driven to be disposed above the second arm 6, for example, like the servo motor 48 shown by a chain line in the drawing. Alternatively, a drive source may be disposed in the second arm 6 so as to drive the timing belt 44 via another pulley (not shown). In this case, since the bottom of the drive source generally protrudes from the second arm 6, the drive source is arranged at a position that does not vertically overlap the turntable 8. As described above, the servo motor 40 is an example of a driving means, and is disposed on the arms 4 and 6 at a position not overlapping the swivel table 8 in the vertical direction, preferably near the joint between the first arm 4 and the second arm 6. Deploy. The timing belt 44 is an example of a transmission unit, and includes a pulley 42 and a pulley 46.
Anything that can be linked can be used.

The operation of the scalar arm 2 will be described. When the servo motor 20 is driven, the first arm 4 rotates via the input shaft 12 and the output shaft 18. At this time, the pulley 16 does not move, and the timing belt 24 does not move. The operation of the harmonic drive 26 will be described assuming that the servomotor 40 is stopped. The pulley 36 is connected to the output shaft 32
And the base 28 is fixed to the first arm 4 so that the output shaft 32 is at the tip of the first arm 4.
It rotates around the harmonic drive 10. On the other hand, since the pulley 36 is rotatable with respect to the output shaft 32 and is stretched around the fixed timing belt 24, it rotates with respect to the timing belt 24. Thus, the pulley 16 and the pulley 36 are linked, and for example, the diameter ratio of the pulley 16 to the pulley 36 is 2: 1.
If the output shaft 18 rotates by the angle θ, the pulley 36 rotates by the angle −2θ. And the second arm 6
Is fixed to the pulley 36, and thus rotates by a double angle to the side opposite to the first arm 4.

When the servomotor 40 is stopped, the pulley 42 is fixed to the tip of the first arm 4, and the pulley 46 moves as the second arm 6 rotates. Here, since the belt 44 is stretched around the pulley 42, the pulley 46 and the pulley 42 are linked at a diameter ratio of, for example, 2: 1. Rotate. To summarize these operations, when the servomotor 40 is stopped, when the first arm 4 rotates by θ, the second arm 6 rotates by −2θ, and the turning table 8 rotates by θ. Performs the same operation as that of the conventional example.

Here, when the servo motor 40 is driven, the pulley 42 rotates further than in the above case, so that the pulley 46 further rotates, and the direction of the turntable 8 can be arbitrarily changed. . That is, with the rotation of the servo motor 40, the rotation of the pulley 42 is further added to the above operation. The drive of the servo motor 40 (the rotation of the turntable 8) is performed by the drive of the servo motor 20 (the arms 4 and 4).
6) or may be performed separately. In the embodiment, the swivel table 8 can be changed to an arbitrary direction by a change such as adding the servomotor 40 to the conventional scalar arm. The servomotor 40 is housed in the first arm 4. For this reason, the size of the scalar arm 2 hardly increases, and in particular, the thickness of the swivel table 8 does not increase as compared with the conventional example. In the embodiment, the first
It can be said that a configuration in which a servo motor 40 of a driving means is connected to a shaft 34 penetrating through a pulley 36 serving as an articulation between the arm 4 and the second arm 6, and an input shaft of the harmonic drive 26 is used. It can also be said that the servomotor 40 is connected.

FIG. 2 shows an automatic warehouse 50 using the scalar arm 2 of the embodiment. In FIG. 2, reference numerals 52 and 54 denote a pair of shelves which accommodate a cassette 56 accommodating semiconductor wafers and the like. The cassette 56 has directionality, and the surrounding transporting devices are in a predetermined direction, respectively.
6 are held and transported, and their directions differ depending on the type of the transporting device.
It is assumed that the direction of 6 needs to be changed.

Reference numeral 58 denotes a crane such as a stacker crane, which is an example of a transfer device inside the automatic warehouse 50. It is assumed that various transport devices are connected to the automatic warehouse 50, and FIG. 2 shows an overhead traveling vehicle 60 and a tracked vehicle 62. 63 is a conveyor for transferring the cassette 56 to and from the tracked carriage 62.

The scalar arm 2 of the embodiment is mounted on a tracked vehicle 62, and the scalar arm 2 of the embodiment is mounted on a crane 58 traveling in an automatic warehouse 50. In addition, for the overhead traveling vehicle 60 having no transfer device, the scalar arms 2 of the embodiment are arranged at a plurality of locations in the automatic warehouse 50 so as to transfer articles to and from the overhead traveling vehicle 60. Then, as shown in FIG. 2, each of the transfer devices 60 and 62 holds and transfers the cassette 56 in various directions.

In the conventional example, in such a case, the cassette 5
A mechanism for changing the orientation of 6 in accordance with the transport device is required. For example, for this purpose, it is necessary to change the direction of the cassette 56 by providing a turning table on the conveyor 63. In the transfer between the shelves 52 and 54 and the overhead traveling vehicle 60, it was difficult to reverse the direction of the cassette 56, so that the traveling route of the overhead traveling vehicle 60 was restricted. On the other hand, when the scalar arm 2 of the embodiment is used, the direction of the cassette 56 can be arbitrarily changed. Therefore, it is not necessary to provide the conveyor 63 with a turning table, and the cassette 5 having a desired
6 can be delivered.

FIGS. 3 and 4 show the scalar arm 2 of the embodiment.
The difference in operation between the scalar arm and the conventional example is shown. First
When the arm 4 rotates by the angle θ, the second arm 6
The turning table 8 is rotated by θ, and the turning table 8 is moved linearly in accordance with the turning, which is common to both the conventional example and the embodiment. However, in the embodiment, since the swivel table 8 can be turned by an arbitrary angle with respect to the second arm 6, the direction thereof can be freely changed. In FIGS. 3 and 4, one side surface 64 of the swivel table 8 is hatched, and in the conventional example, the direction of the side surface 64 is always constant. On the other hand, in the embodiment, the direction of the side surface 64 can be arbitrarily changed, and the cassette 5
6 can be arbitrarily changed.

In the embodiment, the turning table 8 of the scalar arm 2 is rotated in an arbitrary direction. However, the present invention is not limited to this. For example, the swivel table 8 may be any base that can rotate while supporting an article, and may be a fork. In the embodiment, the input shaft of the harmonic drive 26 is
The servo motor 40 is coupled, but is not limited to this.
A driving means may be provided near the joint between the first arm 4 and the second arm 6 to drive a pulley or the like. In the case of the scalar arm 2, unlike the slide fork, the servomotor 40 can be housed in the arms 4 and 6, so that there is little dust generation, and the scalar arm 2 is particularly suitable for mounting on a crane 58 of an automatic warehouse for a clean room.

[Brief description of the drawings]

FIG. 1 is a sectional view of a scalar arm according to an embodiment.

FIG. 2 is a diagram showing an arrangement of an automatic warehouse using the scalar arm of the embodiment.

FIG. 3 is a diagram showing the operation of the scalar arm of the embodiment.

FIG. 4 is a diagram showing the operation of a conventional scalar arm.

[Explanation of symbols]

 2 Scalar arm 4 First arm 6 Second arm 8 Turning table 9 Base 10, 26 Harmonic drive 12 Input shaft 14 Housing 16, 36 Pulley 18 Output shaft 20, 40 Servo motor 42, 46 Pulley 24, 44 Timing belt 22, 38 , 47 Bearing 50 Automatic warehouse 52, 54 Shelf 56 Cassette 58 Crane 60 Overhead traveling vehicle 62 Tracked truck 63 Conveyor 64 Side view

Claims (3)

[Claims] A second arm rotatably supported at a distal end of the first arm, and a swivel table supported rotatably at a distal end of the second arm; In a scalar arm in which a transmission means for linking rotation in the direction is provided in the second arm, a drive source is provided in the first or second arm at a position not overlapping the turning table in the vertical direction. A scalar arm wherein the transmission means is driven independently of rotation of the second arm. 2. The scalar arm according to claim 1, wherein a shaft is provided at a joint between the first arm and the second arm, and the drive source and the transmission unit are connected to the shaft. 3. A transfer apparatus for an automatic warehouse equipped with the scalar arm according to claim 1.