JP4893966B2 - Automatic warehouse - Google Patents

Description

The present invention relates to a stacker crane used in an automatic warehouse, and more particularly to the ascent limit of a lifting platform.

  In some cases, the top shelf of an automatic warehouse rack is a low-load dedicated shelf that is shorter than other shelves. In this case, since the uppermost stop position of the stacker crane is also determined in accordance with the low load, if the load is stopped at the uppermost stop position, it interferes with the upper frame of the stacker crane in the case of a high load. Therefore, conventionally, a photoelectric sensor is arranged on the upper part of the mast to monitor a high load on the lifting platform. If it does in this way, a high load can be detected before interfering with an upper frame etc., and the raising of a platform can be stopped.

However, it is necessary to arrange the light projecting end and the light receiving end of the photoelectric sensor on the upper part of the mast and to prepare their optical axes. This work is a high place work and requires careful work. Further, when the photoelectric sensor is provided on the mast, it is necessary to perform wiring along the mast. Since the mast is tall, wiring work is difficult. Patent Document 1: Japanese Patent Laid-Open No. 7-277417 discloses measuring the height of an article on a lifting platform.
JP-A-7-277417

  An object of the present invention is to prevent a heavy load from interfering with an upper frame of a stacker crane without providing a sensor on the mast.

The present invention includes a stacker crane including a lower carriage, a mast, a lifting platform that moves up and down along the mast, and an upper member provided on an upper portion of the mast ,
It is an automatic warehouse consisting of a rack that stores tall high loads and low low loads and is equipped with a shelf dedicated to low loads at the top level,
In the stacker crane, a first detected member indicating a stop position on a shelf dedicated to low load as an uppermost stop position at the upper portion of the mast, and a first limit indicating a rising limit for high loads lower than the stop position. 2 of the detected member, providing a city together, the lifting platform is provided with a high load sensor for detecting a high load on the lifting platform, a stop position sensor for detecting the first and second of the detected member, the city Further, when the high load sensor detects a high load and the stop position sensor detects the second detected member, there is provided control means for stopping the ascent of the elevator.

Preferably, the stop position sensor includes two photoelectric sensors, a photoelectric sensor that detects the first detected member and a photoelectric sensor that detects the second detected member.
Each of the first and second detected members includes a shielding plate that blocks the optical axis of the photoelectric sensor,
Further, the high load sensor comprises a photoelectric sensor.
In addition, preferably, it further comprises a manual input for manually instructing the ascent of the lifting platform,
The control means, prior to the instruction from the manual input, stops the lifting of the elevator when the high load sensor detects a high load and the stop position sensor detects the second detected member.

  In this invention, a high load sensor and a stop position sensor are provided on the lifting platform, and when the high load sensor detects a high load and the stop position sensor detects the second detected member, the lifting of the lifting platform is stopped. Therefore, there is no need to place a sensor on the top of the mast.

  Further, the stop position sensor is composed of two photoelectric sensors, a photoelectric sensor for detecting the first detected member and a photoelectric sensor for detecting the second detected member, and the first and second detected members are If each is constituted by a shielding plate that blocks the optical axis of the photoelectric sensor, the first and second members to be detected can be reliably detected. Furthermore, if a high load sensor is comprised with a photoelectric sensor, a high load can be detected reliably.

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

1 to 3 show an automatic warehouse 2 and a stacker crane 4 according to an embodiment. In each figure, 2 is an automatic warehouse, the stacker crane 4 travels along a traveling rail 6, and racks 8 are provided on both the left and right sides of the traveling rail 6. In the rack 8, the uppermost shelf is a low load dedicated shelf 10, and the other shelf is a high load / low load shared shelf 12. 14 is a shelf holder. The stacker crane 4 includes a lower carriage 16, a traveling motor 18, a control unit 20, a drum 22, and a lifting motor 24. The drum 22 is rotated, and the lifting platform 30 is moved up and down by a suspension material 26. Reference numeral 32 denotes a slide fork, which may be another transfer device, 34 represents a high load, and 36 represents a low load. For example, the lifting platform 30 moves up and down along a pair of front and rear masts 38 and 39, and the mast may be one mast or four masts. An upper frame 40 is provided so as to span between the masts 38 and 39. Instead of the upper frame 40, an upper carriage or a top board may be provided.

  The control unit 20 controls traveling of the stacker crane 4, raising and lowering of the elevator platform 30, and the slide fork 32 being moved out, and operates according to an instruction from a ground controller (not shown) and a manual instruction from the remote controller 50. There are two types of instructions from the controller on the ground side, one based on a conveyance command that indicates whether the loading position and the unloading position and the article are high or low, and one that supports only the destination manually. An operation mode based on a conveyance command is called an automatic mode. An operation mode in which an instruction from the remote controller 50 or an instruction for only a destination manually from the ground controller is referred to as a manual mode. The control unit 20 or the ground side controller stores which height shelf is a dedicated low load shelf, and inputs, for example, the transfer of the high load 34 to the low load dedicated shelf 10 in an automatic mode. Error can be detected. On the other hand, in the manual mode, since the high load 34 or the low load 36 is not included in the instruction, it may occur that the high load 34 is transferred to the shelf 10 dedicated to the low load. In this case, the high load 34 interferes with the upper frame 40 of the stacker crane 4 and also interferes with the low load dedicated shelf 10.

  A photoelectric sensor composed of a light projecting end 42 and a light receiving end 43 is provided on the lifting platform 30 and supported by a support column 44 to detect a high load 34. A pair of photoelectric sensors 45 and 46 are provided on the lifting platform 30 to detect the shielding plates 47 and 48 provided on the mast 38. The shielding plates 47 and 48 are attached on the ground when the mast is manufactured, and need not be attached at a high place. The shielding plate 47 is a shielding plate for stopping with respect to the uppermost low load dedicated shelf 10, and the shielding plate 48 is a shielding plate showing a rising limit when the lifting platform 30 is loaded with the high load 34. . When the light projecting end 42 and the light receiving end 43 detect that the high load 34 exists and the shielding plate 48 is detected by the photoelectric sensor 46, the control unit 20 stops the ascending / descending platform 30 from ascending according to the ascending stop command. To do. The ascending stop command has priority over a manually ascending command from the remote controller 50 or a controller on the ground (not shown).

  As shown in FIG. 2, the light projecting end 42 and the light receiving end 43 are arranged, for example, diagonally on the lifting platform 30 so that the optical axis crosses the high load 34. Instead of the diagonal line arrangement, the high load 34 may be monitored along a direction parallel to the traveling rail.

  FIG. 3 shows the arrangement of the shielding plates 47 and 48. The shielding plates 47 and 48 are arranged at different heights as shown in FIG. 1, and the photoelectric sensor 45 has a light projecting end and a light receiving end, and detects because the light axis is blocked by the shielding plate 47. Similarly, the photoelectric sensor 46 detects the shielding plate 48. The shielding plates 47 and 48 may be arranged so as to overlap each other, and the photoelectric sensor 46 may be substituted for the photoelectric sensor 45.

  The operation of the embodiment will be described. The control unit 20 of the stacker crane recognizes which height shelf is the low load dedicated shelf 10, and because the distinction between the high load 34 and the low load 36 is described in the transport command, Normally, no attempt is made to unload the high load 34 to the low load dedicated shelf 10. However, when the stacker crane 4 is operated in the manual mode for maintenance or the like, it is unknown to the control unit 20 whether the article on the lifting platform 30 is the high load 34 or the low load 36.

  When the elevator 30 is raised to a position suitable for transfer to the low load dedicated shelf 10 in the manual mode, the high load 34 collides with the upper frame 40. The stop control of the lifting platform 30 to the low load dedicated shelf 10 is performed by the shielding plate 47, but when the shielding plate 47 is detected, the high load 34 has already collided with the upper frame 40. Therefore, the shielding plate 48 provided at a position lower than the shielding plate 47 is detected and detected by the photoelectric sensor 46. Further, the light projecting end 42 and the light receiving end 43 detect whether the article on the lifting platform 30 is a high load 34 or a low load 36. When the high load 34 exists on the lifting platform 30 as described above, the lifting of the lifting platform 30 is stopped when the shielding plate 48 is detected, and the high load 34 is prevented from interfering with the upper frame 40. The stop of ascending takes precedence over the manual instruction from the remote controller 50 or the like.

In the embodiment, the following effects can be obtained.
(1) Interference between the high load 34 and the upper frame 40 can be prevented.
(2) The high load 34 can be detected by the light projecting end 42 and the light receiving end 43, and these are installed on the lifting platform 30, so that installation and maintenance are easy.
(3) The rising limit when the high load 34 is mounted can be detected by the shielding plate 48 and the photoelectric sensor 46. Since the photoelectric sensor 46 is provided on the lifting platform 30 side, installation and maintenance are easy.

In the embodiment, a photoelectric sensor is used as the sensor, but an ultrasonic sensor or a proximity sensor may be used instead. Further, in place of the shielding plates 47 and 48, other marks, bar codes, RFIDs or the like may be provided, and in place of the photoelectric sensor 46, sensors of these marks, bar code readers, RFID readers or the like may be provided.

Side view of an example stacker crane Principal part plan view of the stacker crane of the embodiment The figure which shows the shielding plate of a mast and the photoelectric sensor of a lifting platform in an Example.

Explanation of symbols

2 Automatic warehouse 4 Stacker crane 6 Traveling rail 8 Rack 10 Low load dedicated shelf 12 Shelf 14 Shelf receiver 16 Lower carriage 18 Traveling motor 20 Control unit 22 Drum 24 Lifting motor 26 Lifting material 30 Lifting platform 32 Slide fork 34 High load 36 Low Load 38, 39 Mast 40 Upper frame 42 Light projecting end 43 Light receiving end 44 Post 45, 46 Photoelectric sensor 47, 48 Shield plate 50 Remote controller

Claims (3)

A stacker crane including a lower carriage, a mast, a lifting platform that moves up and down along the mast, and an upper member provided on an upper part of the mast ;
It is an automatic warehouse consisting of a rack that stores tall high loads and low low loads and is equipped with a shelf dedicated to low loads at the top level,
In the stacker crane, a first detected member indicating a stop position on a shelf dedicated to low load as an uppermost stop position at the upper portion of the mast, and a first limit indicating a rising limit for high loads lower than the stop position. 2 of the detected member, providing a city together, the lifting platform is provided with a high load sensor for detecting a high load on the lifting platform, a stop position sensor for detecting the first and second of the detected member, the city An automatic warehouse further comprising control means for stopping the lifting of the lift when the high load sensor detects a high load and the stop position sensor detects the second detected member . The stop position sensor consists of two photoelectric sensors, a photoelectric sensor for detecting the first detected member and a photoelectric sensor for detecting the second detected member,
Each of the first and second detected members includes a shielding plate that blocks the optical axis of the photoelectric sensor,
2. The automatic warehouse according to claim 1, wherein the high load sensor comprises a photoelectric sensor. The controller further includes a manual input for manually instructing raising of the lifting platform of the stacker crane, and the control means has priority over the instruction from the manual input, the high load sensor detects the high load, and the stop position sensor is the first one. The automatic warehouse according to claim 1 or 2, wherein when the two members to be detected are detected, the ascent of the lift is stopped.

Images