JP2010208816A - Transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transfer to an accurate position, even if a cargo is dislocated in the depth direction. <P>SOLUTION: This transfer device is provided with a distance sensor S for measuring a distance along the depth direction up to the cargo and a controller for correcting an extension quantity of a support 12 in response to the measured distance, and corrects dislocation in the depth direction of the cargo 20. A rotary means 24 is arranged for changing the extension direction by rotating the support, and the controller is constituted so as to measure the distance in the depth direction up to the cargo 20 in at least two places by the distance sensor S and to determine a rotational quantity of the rotary means 24 from a difference in the distance in the two places. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a transfer apparatus, and more particularly to correction of an extension amount of the transfer apparatus.

  Luggage placed on an automatic warehouse shelf may shift in the depth direction of the shelf. For example, when a load is manually set in an automatic warehouse, the load may be displaced in the depth direction. Furthermore, there are cases where the luggage is shifted when loading the luggage on the automatic warehouse station with a forklift or the like. If the luggage is transferred to the shelf as it is, the position of the luggage on the shelf is shifted. Furthermore, when an automated warehouse experiences an earthquake, the automated warehouse is likely to shake in the short side direction (the depth direction of the shelf), and the luggage may shift. When a load shifted in the depth direction is transferred with a slide fork or the like, the load may protrude from the platform, or the load may climb onto the guide or stopper when the load is unloaded at the station. This is because the position of the load in the depth direction cannot be obtained, so that the slide fork is extended with a fixed stroke.

  Here, prior art related to this is shown in Japanese Patent Application Laid-Open No. 2002-96906A, in which a pair of left and right markers are provided on a shelf holder of an automatic warehouse to detect the center of the front of the shelf. Since there are a pair of left and right shelf holders in the shelf of the automatic warehouse, when a marker is provided on these, the center point of the pair of markers is the center of the frontage. However, Patent Document 1 does not describe the shift in the depth direction of the luggage.

JP2002-96906A

  An object of the present invention is to enable transfer to an accurate position even when a load is shifted in the depth direction.

The present invention is a transfer device for transferring a load by extending a support portion of the article along the depth direction of the load,
A distance sensor for measuring the distance along the depth direction to the load;
And a controller for correcting the extension amount of the support portion according to the measured distance.

  In the present invention, since the distance in the depth direction to the load can be corrected, the transfer can be performed accurately, and the position in the depth direction of the load when the load is manually set can be corrected.

Preferably, the controller is configured to determine that there is no load when the distance sensor cannot measure the distance to the load.
In this way, not only the position of the load but also the presence or absence of the load can be detected by the same distance sensor.

Preferably, a rotation means for changing the extension direction by rotating the support portion is provided, and the distance in the depth direction to the load is measured at least in two places by the distance sensor,
The controller is configured to determine the amount of rotation of the rotation means from the difference in distance between the two locations.
If it does in this way, it can detect that the load is leaning about the vertical axis, and can correct the extension direction of a support part.

The top view which shows the stacker crane and the load of a shelf in an Example Top view of a modified stacker crane and luggage The figure which shows the example of correction | amendment of the extension amount in a modification, and the calculation example of a stop target position and an inclination angle The figure which shows other examples, such as correction of the amount of expansion, and calculation of an inclination angle The top view which shows the overhead traveling vehicle of an Example, and the load on a side buffer Top view showing fixed transfer device and luggage on linear motor carriage Front view showing fixed transfer device and luggage on linear motor carriage

  In the following, an optimum embodiment for carrying out the present invention will be shown.

  1 to 7 show an embodiment and its modifications. FIG. 1 shows a basic embodiment, 2 is a stacker crane, 4 is a traveling rail, a pair of shelves (not shown) are provided on the left and right of the traveling rail 4, and further illustrated on the left and right of the traveling rail 4. There is a station for unloading and unloading. The stacker crane 2 is an automatic warehouse transfer device including a shelf and a station (not shown). Reference numeral 6 denotes a carriage of the stacker crane 2, for example, a lifting platform 10 that moves up and down along a pair of masts 8, 8. The lifting platform 10 is provided with a slide fork 12 as a transfer means. The transfer means may be a SCARA arm or the like. The stacker crane 2 is a transfer apparatus as a whole, and the slide fork 12 is the transfer means.

  For example, a pair of left and right distance sensors S is provided on the lifting platform 10 on the side facing the luggage 20, and the distance sensor S is, for example, a laser distance sensor, but the front surface of the luggage 20 (the surface facing the slide fork 12). Any sensor can be used as long as it is capable of measuring the distance to (). Further, in the embodiment, a pair of distance sensors S is provided on the assumption that shelves exist on both the left and right sides of the traveling rail 4, but when a shelf exists only on one side, the distance sensor S is provided only on that side. The luggage 20 is, for example, a semiconductor cassette or a cassette of a liquid crystal substrate or a plasma display substrate, and has a known shape and a constant size. The luggage 20 is supported by a shelf holder 22, and an automatic warehouse exists in a clean room, for example. When the distance sensor S obtains the distance y along the depth direction with the luggage 20, the controller 13 corrects the extension amount of the slide fork 12.

  The operation of the embodiment will be described. The stacker crane 2 travels along the traveling rail 4, and the lifting platform 10 moves up and down along the mast 8 and moves to the frontage where the target luggage 20 exists. For example, when the stacker crane 2 stops, the distance sensor S obtains the distance from the front surface of the load 20, that is, the distance y in the depth direction of the load 20. When the distance y is not measurable or the distance y is greater than or equal to a predetermined value, the controller 13 determines that there is no luggage 20 in the shelf receiver 22. When the distance y within the predetermined range is obtained, it is assumed that a load exists, the slide fork 12 is extended, and the load 20 is unloaded from the shelf holder 22. At this time, the controller 13 corrects only the difference between the distance y obtained for the extension amount of the slide fork 12 and the standard distance, so that the load can be accurately transferred even if the load 20 is displaced in the depth direction. Therefore, the load 20 does not protrude on the elevator 10 and does not get on the stopper or the guide when it is unloaded onto the station.

  When unloading the load 20 with respect to the shelf support 22, if the load 20 is accurately placed on the lifting platform 10, the load can be unloaded accurately by extending the slide fork 12 by a predetermined extension amount. Therefore, it is not necessary to use the distance sensor S. However, when the position of the load 20 on the lift 10 is not reliable, the distance y with the front surface of the load 20 is measured by the distance sensor S while the slide fork 12 is extended, and the distance y becomes a predetermined value. At that time, the extension of the slide fork 12 may be stopped and unloaded onto the shelf support 22.

  When the luggage is manually set on the shelf, the luggage 20 is easily displaced in the depth direction. If you set it manually, you can see how far you have pushed the luggage. In addition, when experiencing an earthquake, the shelf is not easily shaken in the long side direction parallel to the traveling rail 4 and is likely to be shaken in the short side direction perpendicular to the traveling rail 4 in the horizontal plane, so that the load easily shifts in the depth direction. Therefore, the stacker crane 2 is used to inspect the presence or absence of the load 20 with respect to each frontage of the shelf, and whether or not the load 20 is displaced along the depth direction of the shelf is checked by the distance sensor S. When the load 20 is displaced by a predetermined length or more, the slide fork 12 is extended according to the distance y obtained by the distance sensor S, the load 20 is lifted up from the shelf receiver 22, and then the slide is eliminated. After returning the extension amount of the fork 12 to the standard value, the fork 12 is unloaded onto the shelf receiver 22. If it does in this way, even if the position of the load 20 shifts, the position can be corrected as long as the travel of the stacker crane 2 is not hindered.

  FIG. 2 and FIG. 3 show modifications in which three types of position of the load 20 in the depth direction, the inclination angle θ around the vertical axis, and the lateral deviation along the traveling direction of the stacker crane are corrected. Reference numeral 3 denotes a new stacker crane, which is provided with a turntable 24 on the lifting platform 10 to rotate the slide fork 12 about the vertical axis. Reference numeral 25 denotes a new controller. Then, a set of distance sensors S1, S2 and a set of distance sensors S3, S4 are provided on the lifting platform 10 along the front and rear in the traveling direction. As will be described later, instead of the pair of distance sensors S1 and S2, one distance sensor S may be provided at the center of the lifting platform 10 in the traveling direction, for example, as in FIG. The width of the front surface of the load 20 is L, the depth is M, and the inclination angle around the vertical axis is θ. Further, the distance along the traveling direction between the distance sensors S1, S2 and the distance sensors S3, S4 is a. The stacker crane 3 is assumed to travel from the right to the left in FIG. In the coordinate system, the position in the traveling direction is represented by x, the position in the depth direction is represented by y, the distance from the sensor S2 to the stop target position is represented by Δx, the correction amount of the expansion amount is Δy, and the standard expansion amount is Let it be STD.

FIG. 3 shows a measurement algorithm such as distance in the embodiment. Assume that the sensor S1 is turned on in 1), and in 2) that the stacker crane 3 further travels a distance a along the traveling direction, and the sensor S2 is turned on. The distance measured by the sensor S2 at this time is y2, and the distance measured by the sensor S1 is y1. Then, the inclination angle θ of the load 20 is obtained by a · tan θ = y1−y2. When the load 20 is greatly inclined, it is preferable to correct the stop position of the stacker crane 3, so the stop target position is obtained. When the turntable 24 is rotated by the inclination angle θ, the extension direction of the slide fork 12 is parallel to the depth direction of the luggage 20. At this time, in order for the intermediate point between the pair of slide forks 12 and 12 to pass through the center of the front surface of the load 20, the stacker crane 3 is further moved from the time when the sensor S1 is turned on.
It is only necessary to travel by Δx = L / 2 · (cos θ) ⁻¹ + y 2 · tan θ −a / 2. Further, the correction amount Δy of the expansion amount may be corrected according to Δy = y 2 · (cos θ) ⁻¹ + L / 2 · tan θ−STD. These grounds are shown in FIG.

FIG. 4 shows a method for calculating the correction amount for the stop target position and the extension amount. The distance when the sensor S2 is turned on is y2, and at this time the sensor S1 is ahead by a distance a and the distance is y1. Then, it can be seen that y1−y2 = a · tanθ. Next, as shown in FIG. 4, when c, d, e, and f are determined, c · cos θ = y 2 and f = y 2 · tan θ are known. It can also be seen that e · cos θ = L / 2. Here, e + f is the distance from the position of the sensor S2 to the position facing the center of the front surface of the luggage 20. Then, e + f = L / 2 · (cos θ) ⁻¹ + y 2 · tan θ. Since the center of the elevator 10 is a / 2 ahead of the sensor S2, it is preferable to travel by Δx = e + f−a / 2. Next, d = c + e · sinθ, so
d = y 2 (cos θ) ⁻¹ + L / 2 · tan θ, and d−STD becomes the correction amount Δy of the expansion amount.

  If it carries out as mentioned above, three types of position shifts, the rotation (inclination) of the load 20 around the vertical axis, the shift in the depth direction, and the shift in the traveling direction of the stacker crane can be obtained. Then, the stop position of the stacker crane, the turning amount of the turntable, and the extension amount of the slide fork can be determined so as to correct these effects. Further, when correcting the posture of the load, the stacker crane is operated so as to correct the influence of the above error, the load 20 is lifted up, and then the stacker crane is moved to the normal position (standard when there is no position shift). The position of the load 20 can be corrected when the turntable is turned to zero and the slide fork is operated with the standard extension amount and unloaded onto the shelf support.

  In the embodiment, the three kinds of errors of the inclination of the load 20, the shift in the depth direction, and the shift along the traveling direction of the stacker crane are corrected, but the shift along the traveling direction of the stacker crane of the load 20 is small and the inclination When the angle θ is small, the rotation angle of the turntable may be obtained by setting a · tan θ = y1−y2 and the extension amount of the slide fork may be corrected by 1/2 (y1 + y2) −STD.

  The process of FIG. 4 can be performed even with one sensor. That is, the sensor S arranged at the center of the traveling direction of the elevator 10 is used, and the distance at the time when the sensor S is turned on (more precisely, when the distance obtained by the sensor S changes discontinuously) is defined as y2. If the distance when traveling for a predetermined length a is y1, the equations in FIG. 4 are established. At this time, since the center of the lift has moved by a distance a after detecting the load 20, the stop position of the stacker crane may be corrected by e + fa.

  FIG. 5 shows an embodiment relating to an overhead traveling vehicle. Reference numeral 40 denotes an overhead traveling vehicle that travels along a traveling rail 41 provided near the ceiling of the clean room. For example, a pair of fall prevention covers 42 and 42 are provided before and after the traveling rail. There is a lateral portion 43 between the fall prevention covers 42, 42, and the lateral portion 43 laterally protrudes the rotational drive 44 in a direction perpendicular to the traveling rail 41 in the horizontal plane. The rotation drive 44 supports the lifting drive 45 and rotates in the horizontal plane. The lifting drive 45 lifts the lifting platform 46, opens and closes a chuck (not shown) provided on the lifting platform 46, and chucks the load 54. Or release.

  A side buffer 50 is provided in parallel with the traveling rail 41. For example, a plurality of support bases 52 are provided on a pair of pipes 51, 51 to support a load 54 such as a FOUP. Then, the upper flange 56 of the load 54 is chucked by the lift 46. Here, when the unloading position of the load 54 with respect to the support base 52 is inappropriate, or when experiencing an earthquake or the like, the load 54 may be displaced in the depth direction of the support base 52. Therefore, for example, the distance to the load 54 is measured by the distance sensor S provided at the center of the lateral portion 43 in the traveling direction, and the distance to move the lifting platform 46 laterally is corrected.

  Further, in the same manner as in FIG. 4, the inclination angle and the depth direction and the lateral direction (travel rail) of the load 54 are used by using the distance when the distance sensor S detects the load 54 and the distance when the distance sensor S travels a predetermined length thereafter. (Direction parallel to 41) can be obtained. Then, the stop position of the overhead traveling vehicle 40, the lateral projection amount at the lateral projecting portion 43, and the rotational amount of the rotational drive 44 can be determined so as to correct the above three types of deviation. Further, after an earthquake, etc., after correcting the above three types of errors and lifting the load 54, the load 54 can be lowered onto the support base 52 in a proper position and posture. In other respects, the embodiment of FIG. 5 is the same as the embodiment of FIGS. 1 to 4, and the signal from the distance sensor S is processed by a controller (not shown) in the overhead traveling vehicle 40.

  6 and 7 show an embodiment relating to the transfer device 60 having a fixed position, in which 62 is a linear motor carriage, 64 is a traveling rail thereof, and the traveling rail 64 is provided with a primary side of the linear motor. The carriage 62 is provided with the secondary side of the linear motor. The load 54 is supported on the support table 63, and the transfer device 60 transfers the load 54 between the load port 66 on the processing device 68 side and the linear motor carriage 62. Reference numeral 70 denotes a scalar arm as transfer means, 71 a hand for supporting the load 54, 72 an arm on the base side, and 73 an arm on the hand 71 side. For example, the distance sensor S is arranged on the support base 75.

In this case, the distance to the luggage 54 is measured by the distance sensor S as shown in FIG. As indicated by the chain line in FIG. 7, when the load is shifted to the position 55, the measured distance changes in proportion to the shift amount. If the extension amount of the hand 71 is corrected according to the obtained distance, the load 54 can be unloaded at an accurate position with respect to the load port 66. In FIG. 7, when a turntable for rotating the SCARA arm 70 is provided and combined with the forward / backward movement of the linear motor carriage 62, the processing of FIG. 4 can be executed.

2, 3 Stacker crane 4 Traveling rail 6 Cart 8 Mast 10 Lifting platform 12 Slide fork 13 Controller 20 Luggage 22 Shelf holder 24 Turntable 25 Controller 40 Overhead traveling vehicle 41 Traveling rail 42 Fall prevention cover 43 Side projection 44 Rotating drive 45 Lifting drive 46 Lifting table 50 Side buffer 51 Pipe 52 Support table 54 Luggage 56 Flange 60 Transfer device 62 Linear motor carriage 63, 75 Support table 64 Travel rail 66 Load port 68 Processing device 70 SCARA arm 71 Hands 72, 73 Arm

S Distance sensor

Claims (3)

A transfer device that transfers a load by extending a support portion of the article along the depth direction of the load,
A distance sensor for measuring the distance along the depth direction to the load;
And a controller for correcting the extension amount of the support portion according to the measured distance.   The transfer device according to claim 1, wherein the controller is configured to determine that there is no load when the distance to the load cannot be measured by the distance sensor. While providing a rotating means for rotating the support portion to change the extension direction,
Measure the distance in the depth direction to the load with at least two places by the distance sensor,
The transfer device according to claim 1 or 2, wherein the controller is configured to determine a rotation amount of the rotation means from a difference in distance between the two locations.

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