JP2007276897A - Double-storage prevention device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-storage prevention device capable of accurately detecting existence of a baggage regardless of the state of a back surface of a storage place. <P>SOLUTION: When the baggage does not exist in the storage place 9, since a light L emitted from a baggage detection sensor 7 reaches a side wall member 10 of the storage place 9 and is reflected in a direction leaving from the sensor 7, the sensor 7 cannot catch a reflection light of the light L and is turned off. Thereby, a control part 8 determines that the baggage does not exist in the storage place 9 and performs storage of the baggage. When the baggage is stored in the storage place 9, the light L emitted from the sensor 7 is reflected by the baggage, and the sensor 7 catches the reflection light and is turned on. Thereby, the control part 8 determines that the baggage exists in the storage place 9 and stops the storage of the baggage. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a double storage prevention mechanism, and more particularly to a mechanism for preventing double storage when a load is stored in a storage place by a transfer device.

  In systems such as automatic warehouses, where loads are stored and stored in a plurality of storage locations formed on shelves using a transfer device, in general, information on the presence or absence of loads at each storage location is stored on the ground control panel and management. Although it is managed by a computer or the like, in that case, if it is stored that the storage location where the load has already been placed is empty for some reason, the transfer device mistakenly loads the load to this storage location. There is a risk of storing it more than once.

  Therefore, for example, in Patent Document 1, a pair of light projecting units and a light receiving unit are arranged at the front ends of a pair of movable arms attached to a transfer device so as to face each other, and an attempt is made to store a load in a storage place. Sometimes, a double storage prevention mechanism that detects the presence or absence of a load based on whether or not the light emitted from the light projecting unit toward the light receiving unit is blocked by allowing these movable arms to enter the storage location together with the load. It is disclosed.

JP 2002-68406 A

However, the double storage prevention mechanism disclosed in Patent Document 1 is configured such that the load moves with the movement of the movable arm, and thus double storage cannot be detected until the load is moved.
Therefore, as a double storage prevention mechanism that can detect the presence or absence of a load at the storage location prior to the movement of the load, for example, light is reflected from the reflective sensor attached to the main body of the transfer device toward the storage location. What emits and detects the presence or absence of a load based on the reflected light is known. In this double storage prevention mechanism, when a load is present at the storage location, the light emitted from the reflective sensor is reflected by the load, and the reflected light is detected by the reflective sensor to detect the presence of the load. When there is no load at the storage location, it can be detected that there is no load by not detecting the reflected light of the light emitted by the reflective sensor.

  By the way, when using a reflective sensor as described above, in general, in order to prevent erroneous detection due to the influence of reflected light on the back of the storage location, the measurement range of the reflective sensor is within a range that does not reach the back of the storage location. It has been adjusted. However, when the load is transparent, it is necessary to increase the sensitivity of the sensor because the reflection at the load is weak. In this case, the light emitted from the reflective sensor reaches the back of the storage location and the back of the storage location. Depending on the state, there is a risk that the reflected light will return and detect that there is a load. In particular, in order to protect the stored items from dust or dust, for example, when the side surface and the back surface of the shelf are covered with a vinyl sheet, erroneous detection is easily caused by strong reflected light from the vinyl sheet.

Further, instead of the reflective sensor, a distance measuring sensor for measuring the distance to an object located in front is provided in the transfer device, and the presence or absence of a load is detected based on the distance measured by the distance measuring sensor. However, if the sides and back of the shelf are covered with a vinyl sheet as described above, the light emitted by the distance measuring sensor is reflected by the vinyl sheet, so adjust the distance. It becomes difficult.
The present invention has been made to solve such problems, and an object thereof is to provide a double storage prevention mechanism capable of accurately detecting the presence or absence of a load regardless of the state of the back of the storage location. To do.

  The double storage prevention mechanism according to the present invention is a mechanism for preventing double storage when a load is stored by a transfer device from the front in the storage location, and is attached to the transfer device and stores the load in the storage location. A load detection sensor for detecting the presence or absence of a load based on the reflected light and emitting light that obliquely crosses the occupied space that the load occupies in the horizontal plane toward the side edge of the storage location; And a control unit that stops storing the load by the transfer device when the load is detected by the load detection sensor when storing the load.

A plurality of load detection sensors may be provided. In this case, the plurality of load detection sensors are preferably arranged so that the light emitted from each other intersects each other.
Further, a side wall member is erected on the side edge of the storage place, and the load detection sensor can be attached to the transfer device so as to emit light toward the side wall member.

  According to this invention, it is possible to accurately detect the presence or absence of a load regardless of the state of the back surface of the storage location.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows an automatic warehouse having a stacker crane equipped with a double storage prevention mechanism according to Embodiment 1 of the present invention. In this automatic warehouse, a shelf 1 for storing luggage is arranged, and a traveling path 2 is laid adjacent to the shelf 1, and a stacker crane 3 can travel along the traveling path 2 freely. It is arranged. A pair of masts 4 are erected on the stacker crane 3, and a carriage 5 is provided along the pair of masts 4 so as to be movable up and down. On the carriage 5, a transfer unit 6 of the transfer device is disposed so as to be movable forward and backward in a direction perpendicular to the traveling path 2. Further, the transfer device has a fixing portion (not shown) that is positioned below the transfer portion 6 and is fixed on the carriage 5, and a load detection sensor 7 including a reflective sensor is attached to the fixing portion. . On the other hand, a control unit 8 for controlling the traveling of the stacker crane 3, the raising and lowering of the carriage 5, the transfer operation of the transfer device, and the like is attached to the outer side of the mast 4.

  The shelf 1 has a plurality of storage locations 9, and a plurality of side wall members 10 as partitions are erected between the plurality of storage locations 9. The carriage 5 of the stacker crane 3 is positioned in front of the predetermined storage location 9 of the shelf 1, and the transfer portion 6 of the transfer device is moved forward and backward in this state to transfer the load to the storage location 9. ing.

  Here, the load detection sensor 7 is for detecting the presence / absence of a load in the storage location 9 and obliquely crosses the occupied space S occupied by the load when the load is stored in the storage location 9 in the horizontal plane. Such light L is attached to the transfer device so as to be emitted toward the side wall member 10 located on one side edge of the storage place 9. When there is no load in the occupied space of the storage place 9, the light L emitted from the load detection sensor 7 reaches a point P located on the surface of the side wall member 10, as shown in FIG. It is configured to be reflected in a direction away from the load detection sensor 7 by P.

  The load detection sensor 7 is electrically connected to the control unit 8, and the control unit 8 and the load detection sensor 7 constitute a double storage prevention mechanism of the present invention.

Next, the operation of the double storage preventing mechanism according to the first embodiment will be described. When storing the load on the shelf 1, the control unit 8 moves the stacker crane 3 along the traveling path 2 and moves the carriage 5 up and down, thereby positioning the carriage 5 in front of the storage location 9.
At this time, when there is no load at the storage location 9, the light L emitted from the load detection sensor 7 reaches the side wall member 10 of the storage location 9 and is reflected in a direction away from the load detection sensor 7. Therefore, the load detection sensor 7 cannot turn off the reflected light of the light L and is turned off. Since the load detection sensor 7 is in the off state, the control unit 8 determines that there is no load in the storage location 9 and moves the transfer portion 6 of the transfer device forward and backward as it is, thereby loading the storage location 9. Store.

On the other hand, when a load has already been stored in the storage location 9, the light L emitted from the load detection sensor 7 is reflected by the load because the load is located in the occupied space S of the storage location 9, The reflected light is captured by the load detection sensor 7, and the load detection sensor 7 is turned on. Since the load detection sensor 7 is in the ON state, the control unit 8 determines that there is a load in the storage place 9 and stops storing the load by the transfer device.
Therefore, the double storage of the load can be reliably prevented by accurately detecting the presence or absence of the load at the storage location 9.
In addition, since the load detection sensor 7 emits light L toward the side wall member 10 of the storage location 9, it can accurately detect the presence or absence of a load regardless of the state of the back surface of the storage location 9.

  FIG. 3 specifically shows a stacker crane 3 equipped with the double storage prevention mechanism according to Embodiment 1 of the present invention. This stacker crane 3 has two transfer devices, and these two transfer devices can simultaneously transfer loads to two storage locations 9 respectively. A load detection sensor 7 is attached to each transfer device via a bracket 11 indicated by a broken line. Therefore, it is possible to accurately detect the presence or absence of a load in the storage place 9 located in front of each transfer device.

Embodiment 2. FIG.
Next, a double storage mechanism according to Embodiment 2 of the present invention will be described with reference to FIG. In the first embodiment, two load detection sensors 7 are attached to the transfer device in the first embodiment at symmetrical positions. That is, of the two load detection sensors 7, one load detection sensor 7 is directed toward the side wall member 10 located at one side edge of the storage place 9, and the other load detection sensor 7 is the other load detection sensor 7. It is arrange | positioned so that light may be emitted toward the side wall member 10 located in a side edge, respectively. Moreover, these two load detection sensors 7 are arrange | positioned so that each emitted light may mutually cross | intersect.
Even with this configuration, as in the first embodiment, it is possible to accurately detect the presence or absence of a load at the storage location and reliably prevent double storage.

  In addition, in the second embodiment, as shown by a two-dot chain line, for example, even when the load is stored in the occupied space S where the light from one load detection sensor 7 does not cross, The detection of the load can be stopped by detecting the presence of the load by the detection sensor 7. Therefore, by using the two load detection sensors 7, it is possible to detect the presence or absence of a load over a wide range of the storage place 9.

  In addition, it is not limited to the two load detection sensors 7, Three or more load detection sensors 7 can also be used.

  In addition, as the load detection sensor 7 in the first and second embodiments described above, a distance measuring sensor that measures the distance to an object located in front can be used instead of the reflective sensor. In this case, the distance to the side wall member 10 is set as a reference value, and the on state is set when the distance measured by the distance measuring sensor is smaller than the reference value, and the off state is set when the distance is greater than the reference value. . Since the side wall member 10 is used as an object for setting the reference value, the reference value can be easily set.

  Moreover, although the load detection sensor 7 was arrange | positioned so that light might be emitted toward the side wall member 10, it replaces with the pillar of the shelf 1 located in the back side of the storage location 9, for example instead. You may arrange | position so that light may be emitted toward. Even in this configuration, when no load is present in the storage place 9, the light emitted from the load detection sensor 7 reaches this column and is reflected in a direction away from the load detection sensor 7. Since the load detection sensor 7 is turned off, the presence or absence of a load can be detected as in the first and second embodiments. In this way, by using a shelf column or the like, the double storage prevention mechanism of the present invention can be applied to a shelf in which the side wall member 10 is not provided.

  In the first and second embodiments, the transfer device transfers the load to the shelf 1 provided on one side of the traveling path 2. However, in an automatic warehouse, the other side of the traveling path 2 is generally used. On the other side, that is, on the side opposite to the one shelf 1 with respect to the traveling path 2, shelves are arranged, and the transfer device is configured to transfer the load to the storage locations of both the shelves. . Therefore, if the load detection sensor 7 is not provided only on the side corresponding to the one shelf 1 in the transfer device, but the load detection sensor is provided on the side corresponding to the other shelf in the same manner, With respect to the shelves on both sides, it is possible to prevent double storage by detecting the presence or absence of the load at the storage location when transferring the load.

  In addition to the transfer device for the stacker crane 3, the unmanned forklift having the transfer device and other various transport devices can be equipped with the double storage prevention mechanism of the present invention to prevent double storage of the load. it can.

It is a partial top view which shows the automatic warehouse which has a stacker crane equipped with the double storage prevention mechanism which concerns on Embodiment 1 of this invention. 3 is a perspective view showing a structure in the vicinity of a side wall member in Embodiment 1. FIG. It is a partial top view which shows concretely the stacker crane 3 equipped with the double storage prevention mechanism which concerns on Embodiment 1 of this invention. It is a partial top view which shows the automatic warehouse which has a stacker crane equipped with the double storage prevention mechanism concerning Embodiment 2 of this invention.

Explanation of symbols

  1 shelf, 2 travel path, 3 stacker crane, 4 mast, 5 carriage, 6 transfer section, 7 load detection sensor, 8 control section, 9 storage location, 10 side wall member, 11 bracket.

Claims (4)

In the mechanism to prevent double storage when storing the load with the transfer device from the front in the storage place,
Based on the reflected light that emits light toward the side edge of the storage place that obliquely crosses the occupied space occupied by the load in the horizontal plane when the load is stored in the storage place. A load detection sensor for detecting the presence or absence of the load,
A double storage prevention mechanism, comprising: a control unit that stops storage of the load by the transfer device when the load is detected by the load detection sensor when storing the load in the storage location. .   The double storage prevention mechanism according to claim 1, comprising a plurality of the load detection sensors.   The double storage prevention mechanism according to claim 2, wherein the plurality of load detection sensors are arranged so that light emitted from each of the load detection sensors intersects with each other.   The side wall member is erected on the side edge of the storage place, and the load detection sensor is attached to the transfer device so as to emit light toward the side wall member. The double storage prevention mechanism described.

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