JP4331316B2 - Load transfer position detection device in automatic warehouse - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a load transfer position detection apparatus in an automatic warehouse in which loads are loaded and unloaded using a stacker crane at target positions of a plurality of stages of load shelves.
[0002]
[Prior art]
Multiple loading shelves are arranged in multiple stages, and a stacker crane provided on the side of the floor is run in the horizontal direction, and the loading platform provided on it is moved up and down along the mast to load the cargo at the desired position on the loading shelf. Various automatic warehouses have been proposed.
[0003]
In such an automatic warehouse, a travel stop position detection sensor for moving the loading platform of the stacker crane to the target position of the load shelf and a lift stop position detection sensor are indispensable.
[0004]
[Problems to be solved by the invention]
In general, the number of the travel stop position detection sensors is provided for each position of the load placed on the load shelf of each stage, and the number of the lift stop position detection sensors is provided for each load shelf of each stage. However, the following problems may occur.
[0005]
That is, in order to accurately load and unload the load at the target position of the load shelf, it is necessary to improve the accuracy of the stop position of the loading platform of the stacker crane, and for that purpose, the mounting accuracy of each sensor must be improved. However, even if each sensor is accurately installed at the design position, errors in manufacturing and assembling each stage of load racks and stacker cranes, etc., deflection of load racks due to load loads, inclination of stacker crane masts, etc. As a result, the initial mounting position of the sensor may be deviated, and the stop position of the loading platform may vary, which may hinder the loading / unloading work.
[0006]
In order to prevent this, the installation position of each sensor can be finely adjusted again after installation of the automatic warehouse, i.e. after assembling all the load racks, stacker cranes, etc., to improve its installation accuracy, or The detection range by each sensor for raising and lowering and traveling is expanded to increase the allowable range of the stop position of the stacker crane and loading platform, but if the former is used, much time is required for fine adjustment of each sensor. In the latter case, it is necessary to increase the distance between the upper and lower cargo racks and the load placement interval, so the number of loading racks and the number of loads placed on the cargo racks are reduced. The housing efficiency is reduced.
[0007]
The present invention has been made in view of the above problems, as the unnecessary fine adjustment of the position of the sensor for run line stop, while omitting the operations required thereto, to stop accurately the loading platform to the target position of Nitana Accordingly, it is an object of the present invention to provide a load transfer position detecting device in an automatic warehouse, which can smoothly perform loading / unloading operations and increase load storage efficiency.
[0008]
[Means for Solving the Problems]
According to the present invention, the above problem is solved as follows.
(1) A mast of a stacker crane that travels on the floor surface on the side of a plurality of stages of loading racks is provided with a loading platform having transfer means for loading and unloading loads on the loading rack so that the stacker crane can travel. In the automatic warehouse in which the loading platform is moved up and down to the target position of the loading rack and stopped, and the loading and unloading of the loading platform is carried out at that position, the loading rack at the appropriate position below the stacker crane and the floor surface First travel stop position detecting means for detecting that the stacker crane has reached an appropriate travel stop position corresponding to the load storage position is provided at a position corresponding to the load load upper position, and the load platform in place on the side facing the load shelf that put in, and the bed, the second travel stop position detecting means for detecting a longitudinal displacement between the part corresponding to the housing position of the load of each load shelf provided, this Second The row stop position detecting means is a pair of reflective photoelectric sensors spaced apart in the horizontal direction, and spaced apart on the optical axis of both photoelectric sensors on the side end surface corresponding to the load receiving position in the load shelf. Detection holes that are slightly larger than the number of loads are formed in the opposite surfaces of the left and right shelves in alignment with the front ends of the regular accommodation positions of the loads .
[0009]
(2) In the above item (1), the second travel stop position detecting means can detect positions before and after the detection hole.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of an automatic warehouse to which the present invention is applied, and FIG. 2 is an enlarged cross-sectional plan view taken along line II-II in FIG.
[0011]
In both figures, between the floor (1) in the warehouse and the support rod (2) fixed in the front-rear direction (hereinafter, the direction will be described with the left side in FIG. 1 as the front) near the ceiling. Each of the right and left support columns (3) and (3) is erected with a predetermined distance in the front-rear direction and a required distance in the left-right direction.
[0012]
A large number of shelves (4) are fixed to the front and rear surfaces of each of the two right and left support columns (3) at predetermined intervals in the vertical direction. A rack (5) made of these is installed facing in the front-rear direction (the left rack is partially omitted in FIG. 1).
[0013]
A traveling rail (6) is laid in the center between the left and right racks (5) on the floor (1), and a self-propelled stacker crane (7) is placed on the traveling rail (6). ) Is mounted so as to be movable in the front-rear direction.
[0014]
The stacker crane (7) includes two front and rear masts (9) and (9) erected on the base (8), a loading platform (10) that moves up and down between the masts (9) and (9), and a traveling drive. A device (11) and a lifting / lowering drive device (12) for the loading platform (7) are provided.
[0015]
A pair of front and rear guide rollers (14) and (14) are mounted on a connecting rod (13) connecting the upper ends of both masts (9) so as to be rotatable about a vertical axis. ) Is fitted into a downward U-shaped guide rail (15) provided near the ceiling in the warehouse so as to face the traveling rail (6), and thus the stacker crane (7) as a whole is fitted. , Can travel stably in the front-rear direction.
[0016]
The travel drive device (11) includes a motor (16) fixed to the lower end of the front mast (9) and capable of rotating in the forward and reverse directions, and a drive gear (17 The drive gear (17) meshes with the rack (18) carved in the front-rear direction on the upper surface of the traveling rail (6), and the gear (17) rotates forward and backward to rotate the stacker. The entire crane (7) can travel in the front-rear direction along the traveling rail (6).
[0017]
(19) is a driven gear provided at the lower end of the rear mast (9), and meshes with the rack (18) to roll while receiving the load on the rear side of the stacker crane (7). It is supposed to be.
[0018]
The raising / lowering drive device (12) includes a motor (20) for raising and lowering that can rotate forward and backward, a drive chain (23) hung between the drive sprocket (21) and the driven sprocket (22), and a driven A small-diameter drive sprocket (24) fixedly fitted to the rotating shaft of the sprocket (22), a lower end of the rear mast (9), a base (8), and a connecting rod (13) at the upper end of the mast (9) It consists of an elevating chain (26) hung around the idle sprocket (25) at the front and rear, and both ends of the elevating chain (26) are connected to the front and rear at the upper end of the loading platform (10) and the lower rear end ing.
When the motor (20) is rotated forward and backward, the lifting chain (26) is driven, so that the loading platform (10) is raised and lowered.
[0019]
At the four corners of the side plates (28) and (28) erected at the front and rear ends of the rectangular frame base (27) in the loading platform (10), and almost at the center, are respectively around the axis facing the front and rear direction. Four guide rollers (29) that can rotate and a guide roller (30) that can rotate about an axis that faces in the left-right direction are pivotally mounted, and each guide roller (29) (30) has a mast (9 ) Is in sliding contact with the left and right side surfaces and the inner side surface.
Thereby, the loading platform (10) can be stably raised and lowered while being guided by both masts (9).
[0020]
A mounting table (31) for transferring the load (W) on the load rack (4) is attached to the upper surface of the base (27), and on the upper and lower surfaces sandwiching the mounting table (31), A pair of transfer devices (32) for holding and transferring a load (W) placed at regular intervals on the load shelf (4) is provided.
[0021]
The transfer device (32) includes a pair of front and rear support plates (34) and (34) which are guided by the left and right guide members (33) on the base (27) and can move in the front-rear direction. 34) and a grip plate (35) attached to the opposite surface of the support plate (34) so as to be slidable in the left-right direction. The grip plate (35) is fixed to the left and right shelves (4). A lateral feed means (36) (36) consisting of a pair of drive motors reciprocally moved to the vicinity of the front and rear surfaces of the load (W), and a lower side of the mounting table (31). Clamping means (not shown) for gripping or releasing the load (W) by both gripping plates (35) by relatively moving in the approaching and separating directions simultaneously.
[0022]
A photoelectric sensor (37a) in the first raising / lowering stop position detecting means (37) composed of a light emitting element and a light receiving element is attached to the left side of the rear surface of the base (27) of the loading platform (10). At the position on the left side of the mast (9) that is flush with the upper surface of each stage of the shelf (4), the platform (10) is placed on each shelf (4 ) And operating pieces (37b) to be stopped at positions corresponding to the number of the load racks (4).
[0023]
As shown in FIG. 1, a photoelectric sensor (38a) similar to the above in the first traveling stop position detecting means (38) is attached to the left surface of the base (8) of the stacker crane (7). By blocking the optical axis of the photoelectric sensor (38a) at the position corresponding to the front end of the load (W) lined up in the front-rear direction stored in the appropriate storage position on the load shelf (4) on the floor surface (1) The working piece (38b) for stopping the stacker crane (7) from traveling at a position where the center between the gripping plates (35) and the center of the load (W) in the loading platform (10) substantially coincide with each other. 4) The same number of loads (W) as those mounted on the traveling rail (6) are attached.
[0024]
On both the left and right sides of the base (27) of the loading platform (10), a second lift stop is detected that detects a deviation between the actual position of the upper and lower loading racks (4) and the vertical position of the loading platform (10). The position detection means (39) and the actual load of the load (W) placed on it by detecting the displacement in the front-rear direction between the regular load storage position on the load shelf (4) and the loading platform. Second traveling stop position detecting means (40) for indirectly detecting the position of the vehicle is provided.
[0025]
The second traveling stop position detecting means (40) is formed on the opposite surfaces of the left and right cargo racks (4) by the number of loads (W) in alignment with the front ends of the regular accommodation positions of the loads (W). The positions before and after the detection hole (41) are detected.
[0026]
As shown in FIG. 3, the second lifting / lowering stop position detecting means (39) and the second traveling stop position detecting means (40) are respectively connected with the optical axes (39b) and (40b) of the front and rear shelves (4). It consists of a pair of diffusely reflective photoelectric sensors (39a) (40a) oriented in the direction perpendicular to the end face. The vertical distance between the optical axes (39b) of the photoelectric sensors (39a) for raising and lowering is The plate thickness of the shelf (4) is slightly smaller, and the distance between the optical axes (40b) of the traveling photoelectric sensor (40a) in the front-rear direction is slightly smaller than the width of the detection hole (41) in the front-rear direction. It is as.
[0027]
In addition, as shown in FIG. 3, the optical axis (39b) of each photoelectric sensor (39a) for raising / lowering is opposed to the end surface of the cargo rack (4), and both photoelectric sensors (39a) are both turned on (or turned off). ), The loading platform (10) of the stacker crane (7) stops raising and lowering at a position where the upper surface of the mounting table (31) is substantially aligned with the upper surface of the loading rack (4). .
[0028]
In addition, when the optical axis (40b) of each photoelectric sensor (40a) for traveling is located in the detection hole (41) and both the photoelectric sensors (40a) are both off (or on), the stacker crane ( In 7), the traveling stops at a position where the center of the mounting table (31) in the front-rear direction substantially coincides with the center of the load (W) in the front-rear direction.
[0029]
When a control device (not shown) issues a command to load / unload the load (W) to / from the target position on the load shelf (4), the travel drive device (11) is actuated and the stacker crane (7) is moved back and forth. While starting to travel in either direction, the platform (10) starts to move up and down by the operation of the lifting drive (12).
[0030]
The loading platform (10) stops at a position facing the target loading rack (4) when the photoelectric sensor (37a) attached to the loading platform (10) is turned on by one of the operating pieces (37b) of the mast (9). .
At this time, for example, if an error occurs in the mounting position of the photoelectric sensor (37a) or the operating piece (37b) due to an error such as the size or assembling accuracy of each member constituting the stacker crane (7), the loading platform (10 ) Stop position may be shifted up and down, but this shift is corrected as follows.
[0031]
That is, as shown in FIG. 4, for example, when the stop position of the loading platform (10) is displaced downward, the photoelectric sensor (39a) for raising and lowering is also displaced downward with respect to the loading shelf (4). The optical axis (39b) of the photoelectric sensor (39a) is deviated from the front surface of the cargo rack (4).
[0032]
When this happens, the photoelectric sensor (39a) on the lower side becomes inactive, and the control device issues a detection signal to the effect that the loading platform (10) has shifted downward relative to the loading rack (4) and stopped. The driving device (12) is actuated again, and the loading platform (10) is raised to a position where the upper and lower photoelectric sensors (39a) are actuated together, that is, the state shown in FIG. The position control of the loading platform (10) at this time is accurately performed by precisely controlling the rotation of the drive motor of the elevating drive device (12) by a rotary encoder provided on the platform.
Thereby, the shift of the loading platform (10) is corrected, and the upper surface of the mounting table (31) and the loading shelf are aligned, so that the loading and unloading operation of the load (W) at the target position can be performed without any trouble.
[0033]
When the stop position of the loading platform (10) is shifted upward, the photoelectric sensor (39a) on the upper side becomes inoperative, so the loading platform (10) is corrected downward, contrary to the above. .
[0034]
On the other hand, when the travel stop position of the stacker crane (7) is shifted back and forth due to an error in the mounting position of the photoelectric sensor (38a) or the operating piece (38b) for traveling, the traveling mounted on the loading platform (10) It is corrected by the photoelectric sensor (40a) for use.
[0035]
That is, as shown in FIG. 5, when the stop position of the stacker crane (7) is shifted forward, the optical axis (40b) on the front side of the traveling photoelectric sensor (40a) is moved to the load shelf (4). And the photoelectric sensor 40a is turned on (or off), and it is detected that the stop position of the stacker crane (7), that is, the loading platform (10) is shifted forward.
Then, the control device operates the travel drive device (11) again, and retracts the stacker crane (7) until the optical axes (40b) of both photoelectric sensors (40a) are positioned in the detection hole (41) ( FIG. 3).
[0036]
At this time, the position control of the stacker crane (7) is also accurately performed by precisely controlling the rotation of the motor (16) of the travel drive device (11) by a rotary encoder provided thereon.
[0037]
Thereby, the shift | offset | difference of the front-back direction with respect to the load (W) of a loading platform (10) is correct | amended, and the loading / unloading operation | work of the load (W) to the regular load accommodation position can be performed.
In addition, even when the stop position of the stacker crane (7) is shifted backward, it is corrected by the operation opposite to the above.
[0038]
Thus, in the present invention, the photoelectric sensors (37a) (38a) and the operating pieces (37b) (38b) for determining the lifting stop position of the loading platform (10) and the travel stop position of the stacker crane (7) are provided. The final stopping position of the loading platform (10) is the position of the actual load (W) by the photoelectric sensor (39a) for raising and lowering and the photoelectric sensor (40a) for traveling. Therefore, the loading platform (10) can be accurately stopped at the target position, so that after installing the automatic warehouse, the photoelectric sensors (37a) (38a) There is no need to finely adjust the mounting positions of (37b) and (38b) again, or to increase the dimensional accuracy and assembly accuracy of various members constituting the automatic warehouse.
[0039]
In addition, when a photoelectric sensor (39a) for correcting the raising / lowering position is provided, as shown in FIG. 6, the center part of the cargo rack (4) is bent by the load of the load (W) and shifted to the stop position of the loading platform (10). Even when the occurrence of this occurs, the deviation can be corrected as described above, and the load (W) at the target position can be taken in and out without any trouble.
[0040]
Accordingly, it is possible to lengthen the front / rear length of the load rack (4) by minimizing the number of support columns (3) of the load rack (4), and the load storage space for the load (W) becomes large. The load accommodation efficiency increases, and the cost can be reduced.
[0041]
The present invention can be applied to a single mast type stacker crane, a loading platform provided with a shuttle fork or a pusher type transfer means in addition to the above two mast type stacker crane.
[0042]
【The invention's effect】
According to the first aspect of the present invention, an error occurs in the mounting position of the first traveling stop position detecting means of the stacker crane and the mounting position in the front-rear direction of the load shelf, or the mast of the stacker crane is tilted. Even if the stop position is shifted in the front-rear direction, the second traveling stop detection means detects the position shift and corrects the stop position in the front-rear direction of the cargo bed, so that the cargo bed is accurately stopped at the target position of the cargo rack. The cargo can be loaded and unloaded without any problem.
[ 0043 ]
In addition, it is possible to detect whether the loading platform of the stacker crane has shifted in the front or back direction with respect to the detection hole, the position of the stacker crane can be corrected quickly, and the photoelectric sensor is activated by the detection hole. There is no need to attach a separate object.
Furthermore, since the detection hole can be easily formed by punching or the like in the manufacturing process of the cargo rack, it is extremely inexpensive.
[0044]
According to the second aspect of the present invention, since the second traveling stop position detecting means detects the positions before and after the detection hole, the stop position of the stacker crane can be stopped accurately.
[Brief description of the drawings]
FIG. 1 is a side view showing a part of a left loading rack in an automatic warehouse equipped with an embodiment of the present invention.
2 is an enlarged cross-sectional plan view of a main part taken along line II-II in FIG.
3 is an enlarged longitudinal sectional side view taken along line III-III in FIG.
FIG. 4 is an enlarged longitudinal sectional side view showing the positional relationship between the photoelectric sensor and the cargo rack when the cargo bed is shifted downward and stopped with respect to the cargo rack.
FIG. 5 is an enlarged longitudinal side view showing the positional relationship between the photoelectric sensor and the detection hole of the cargo rack when the stacker crane is shifted forward and stopped.
FIG. 6 is a side view of the main part showing the positional relationship between the photoelectric sensor and the load shelf when the load shelf is bent downward.
[Explanation of symbols]
(1) Floor surface
(2) Support rod
(3) Prop
(4) Cargo shelf
(5) Rack
(6) Running rail
(7) Stacker crane
(8) Base
(9) Mast
(10) Loading platform
(11) Travel drive device
(12) Lifting drive device
(13) Linkage
(14) Guide roller
(15) Guide rail
(16) Motor
(17) Drive gear
(18) Rack
(19) Driven gear
(20) Motor
(21) Drive sprocket
(22) Driven sprocket
(23) Drive chain
(24) Drive sprocket
(25) Idle sprocket
(26) Lifting chain
(27) Base
(28) Side plate
(29) (30) Guide roller
(31) Mounting table
(32) Transfer equipment
(33) Guide member
(34) Support plate
(35) Grip plate
(36) Transverse feed means
(37) First lifting stop position detecting means
(37a) Photoelectric sensor
(37b) Actuator
(38) First travel stop position detection means
(38a) Photoelectric sensor
(38b) Actuator
(39) Second lift stop position detecting means
(39a) (40a) Photoelectric sensor
(39b) (40b) Optical axis
(40) Second travel stop position detection means
(41) Detection hole
(W) Load

Claims (2)

On the mast of the stacker crane that travels on the floor surface of the side of the multi-stage cargo rack, a loading platform having transfer means for loading and unloading the cargo to the cargo rack is provided so that it can be moved up and down. By moving up and down, the loading platform is moved to the target position of the loading shelf and stopped, and at that position, the automatic warehouse that loads and unloads the load,
First detecting that the stacker crane has reached an appropriate travel stop position corresponding to the storage position of each load at a position below the stacker crane and a position corresponding to the load storage position on the load shelf on the floor surface. the travel stop position detecting means is provided for, and in place on the side facing the load shelf that put on the loading platform, for detecting the loading platform, the longitudinal positional deviation of the part corresponding to the housing position of the load of each load shelf A second travel stop position detecting means is provided , and the second travel stop position detecting means is a pair of reflective photoelectric sensors spaced apart in the horizontal direction, and corresponds to the storage position of each load on the load shelf. The number of loads is adjusted so that the detection holes, which are slightly larger than the separation distance on the optical axis of both photoelectric sensors, are aligned with the front ends of the regular storage positions of the loads on the opposite surfaces of the left and right shelves. you in the automated warehouse, characterized in that only bored Loading the transfer position detecting device that.   2. The load transfer position detecting device in an automatic warehouse according to claim 1, wherein the second traveling stop position detecting means detects positions before and after the detection hole.

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