JPH09208199A - Pallet picking method by fork lift-type automated guided vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pick a pallet having the different form by the same fork lift-type automated guided vehicle. SOLUTION: Two forks 11 are so constituted as to be moved in the lateral direction, inserting port searching units 16a, 16b for searching fork inserting ports of respective pallets are provided on the tips of the forks 11, the fork inserting ports are searched by inserting port searching units 16a, 16b after the forks 11 are raised to the inserting level in the vertical direction, two forks are positioned at the inserting level in the lateral direction of the fork inserting ports of the pallet, the forks are inserted into the fork inserting ports after advance, the forks are inserted into the fork inserting ports, after that, the forks 11 are raised by the specified amount, and the pallet is picked up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pallet picking method for a forklift type unmanned vehicle.

[0002]

2. Description of the Related Art Conventionally, in this type of pallet picking method using a forklift type unmanned vehicle, since the pallet to be handled is of one type, the level of insertion of the fork is constant both vertically and horizontally. There was no need to search fork pallet inserts during operation.

FIG. 9 is a diagram showing a schematic structure of a conventional forklift type unmanned vehicle of this type. As shown in the figure, the unmanned vehicle 10 is provided with two forks 11, and the forks are raised and lowered by a fork drive device (not shown). Further, the fork 11 is provided with a load presence / absence detector 12 for detecting the presence / absence of a load, and the unmanned vehicle 10 has an upper level detector 13 for detecting that the fork is at the upper level, and a fork at the insertion level. An insertion level detector 14 for detecting and a lower level detector 15 for detecting that the fork is at a lower level are provided.

The unmanned vehicle travels along a predetermined route by a guide device and a traveling device (not shown), and temporarily stops at a predetermined position (front position of the load receiving tray) opposite to the picking pallet. Next, the fork drive device raises the fork 11 until the insertion level detector 14 detects the fork 11. The fork insertion level position is fixed by the height of the receiving tray. Next, the unmanned vehicle 10 is moved forward by the traveling device, and the fork 11 is inserted into the fork insertion opening by a predetermined amount (picking amount) and stopped.

The fork drive device raises the fork 11 until it is detected by the upper level detector 13, and places the pallet on the loading platform on the fork 11. Next, in this state, the unmanned vehicle 10 is retracted by the traveling device by a predetermined amount (at least until the tip of the fork 11 leaves the edge of the load carrier).
Next, the fork drive device lowers the fork 11 until the lower level detector 14 detects the fork 11. After that, the unmanned vehicle 10 travels along the predetermined route by the guiding device and the traveling device, and carries the pallet to the destination.

[0006]

In the above-mentioned conventional pallet picking method using a forklift type unmanned vehicle, since the pallet has one type and the fork insertion opening of the pallet is constant, the insertion level detector 14 and the fork 11 are different from each other. The picking operation was possible only by detecting that the in-level was reached. That is, it is possible to pick up by raising the fork 11 to the insertion level, then moving the unmanned vehicle 10 forward, and raising the fork 11 to the upper level. However, when the pallets to be handled have various shapes, the size and position of the fork insertion port differ depending on the pallet, and the fork insertion position also differs depending on the pallet shape. Therefore, the conventional method has a problem that the pallet cannot be picked.

Further, since the insertion level detector 14 is conventionally provided on the vehicle body of the unmanned vehicle 10, there is a problem that the insertion level of the fork fluctuates due to the air pressure of the unmanned vehicle and the unevenness of the running ground or floor. However, in extreme cases, there were problems that the fork could not be inserted and that an accident occurred.

The present invention has been made in view of the above-mentioned points, and it is possible to pick up pallets having different shapes with the same forklift type unmanned vehicle, and the vertical fork insertion level is always from the ground or floor. An object of the present invention is to provide a pallet picking method by a forklift type unmanned vehicle that can be set to a constant value.

[0009]

In order to solve the above-mentioned problems, the invention according to claim 1 is a pallet picking method by a forklift type unmanned vehicle equipped with a fork for pallet picking, and the unmanned vehicle is a pallet. After raising the fork to the vertical insertion level at a predetermined position opposite to, move forward and insert the fork into the fork insertion port of the pallet, then raise the fork by a predetermined amount and place the pallet on the fork. Then, in the pallet picking method by a forklift-type unmanned vehicle in which the fork is lowered by a predetermined amount and then the fork is lowered to a lower level by a predetermined amount to pick up the pallet, the unmanned vehicle searches the fork insertion port of the pallet. It is equipped with a mouth finder, and the forks consist of two forks, each fork moving laterally. The fork insertion port of the pallet is searched by searching the fork insertion port with the insertion port search means after raising the two forks to the vertical insertion level. Is positioned at the horizontal insertion level and then moved forward to insert the fork into the fork insertion port.

[0010] The invention described in claim 2 is the same as the claim 1.
In the pallet picking method for a forklift-type unmanned vehicle as described in 1, the insertion port search means is provided at the tip of each of the two forks, and after the two forks are lifted to the vertical insertion level, the forks are removed. It is characterized in that the forks are moved in the lateral direction, the fork insertion devices of the pallets detect the fork insertion holes of the pallets, and the forks are inserted when the horizontal insertion level is reached.

[0011] The invention according to claim 3 is based on claim 1.
Alternatively, in the pallet picking method for a forklift type unmanned vehicle according to a second aspect, the vertical insertion level is set from the traveling ground or floor surface of the unmanned vehicle.

The invention described in claim 4 is the first invention.
Alternatively, in the pallet picking method for a forklift type unmanned vehicle according to claim 2 or 3, after the pallet is placed on the two forks, the center between the two forks is positioned at the center of the unmanned vehicle. It is characterized by doing.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a forklift type unmanned vehicle used in the pallet picking method of the present invention. The unmanned vehicle 10 includes a fork 11 and a load detector 1
2. The point that the upper level detector 13 and the lower level detector 15 are provided is the same as the conventional example shown in FIG. At the tips of both forks 11 of the unmanned vehicle 10, insertion port searchers 16a and 16b for searching fork insertion ports of a pallet are provided, and a difference for setting a fork insertion level in the vertical direction from the ground or floor. A built-in level setter 17 is provided.
Further, the fork 11 is composed of two forks, each of which is configured to be independently movable in the lateral direction.

The outlet searchers 16a and 16b emit ultrasonic waves or light, detect reflected waves of the ultrasonic waves or light, and detect whether or not there is an obstacle ahead. If the fork insertion port of the pallet is located at the tip of the insertion port search device 16a, 16b, ultrasonic waves and light pass through and there is no reflected wave, and it is detected as a fork insertion port, and the insertion port search is performed. Bowl 16
If there is a pallet scale at the tips of a and b, ultrasonic waves and light are reflected by the scale and it is detected that it is not the fork insertion slot.

FIG. 2 is a diagram showing the flow of the pallet picking operation by the unmanned vehicle 10. In the pallet picking method, a guide device and a traveling device (not shown) travel along a predetermined route, and temporarily stop at a predetermined position (position before the load receiving tray) facing the picked pallet. Next, the fork 11 is lowered to the ground (or floor) by the fork drive device (step ST1). Next, the fork 11 is raised to the vertical fork insertion level set by the insertion level setting device 17 (step ST2). After lowering the fork 11 to the ground (or floor surface) in this way,
By raising to the insertion level, the fork 11 can be set (positioned) to a predetermined insertion level regardless of the tire air pressure of the unmanned vehicle 10 and the unevenness of the ground (or floor).

Next, the insertion port searcher 16 at the tips of both forks
Start a and 16b (step ST3). Normally, when the insertion port searchers 16a and 16b are activated, as shown in FIG. 3, the fork 11 has a height at which the pallet 18 can be picked (inserted), so both insertion port searchers 16a and 16b.
Although the ultrasonic waves and light emitted from the fork pass through the fork insertion port 18c of the pallet 18, as shown in FIG.
If there are digits 18a and 18b of the pallet 18 at the end of the, the ultrasonic waves and light are reflected by the digits 18a and 18b.

Next, it is judged whether or not the insertion port searchers 16a and 16b detect the fork insertion port 18c of the pallet 18 (step ST4), and if YES, FIG. 3 (a).
The fork 11 is moved to the outside as shown in (step ST5). Subsequently, the insertion port searchers 16a and 16b are shown in FIG.
The columns 18a and 18b of the pallet 18 as shown in (b)
Is detected (step ST6), and if YES, the movement of the fork 11 is stopped (step S).
T7). Subsequently, the fork 11 is moved inward and stopped when the insertion port searchers 16a and 16b detect the fork insertion port 18c (step ST8).

Positions where both forks 11 can be inserted into the fork insertion openings 18c of the pallet 18, that is, both forks 11
It is determined whether or not the position has reached the horizontal insertion level (step ST9), and if YES, the picking operation is started (step ST10). That is, the unmanned vehicle 10 is moved forward by the traveling device, the fork 11 is inserted into the fork insertion port 18c of the pallet 18 by a predetermined amount and stopped, and then the fork 11 is raised until the upper level detector 13 detects it, and the fork 11 is placed on the loading platform. Place the pallet on the fork 11.

In step ST4, when the insertion slot searchers 16a and 16b have not detected the fork insertion slot 18c, that is, as shown in FIG. 4A, the digits 18a and 18b of the pallet 18 are detected. If yes, step ST
8, the fork 11 is moved inward, and when the insertion port searchers 16a and 16b detect the fork insertion port 18c as shown in FIG. 4B, the operation is stopped.

In step ST9, if both forks 11 are not in the positions where they can be inserted into the fork insertion ports 18c of the pallet 18, that is, if the fork lateral insertion level is not reached, both forks 11 are moved laterally. Until the other fork reaches the horizontal insertion level (step ST11), both forks 11 are set to the horizontal insertion level. When reaching, the picking operation is started (step ST12).

Further, in the step ST6, the insertion port searchers 16a and 16b are the digits 18a of the pallet 18,
If b is not detected, it is abnormal, so the fork 11 is moved to the end (step ST13), and an alarm or light is displayed (step ST14).

As described above, when the fork 11 is lifted to the upper level by the picking operation and the pallet 18 is placed on the fork 11, the unmanned vehicle 10 is then placed in this state.
Moves a predetermined amount (at least until the tip of the fork 11 leaves the edge of the bed), and then lowers the fork 11 until the lower level detector 14 detects the fork 11. After that, the unmanned vehicle 10 travels along a predetermined route by the guiding device and the traveling device to carry the pallet to the carrying destination.

In the bookbinding industry and the like, a so-called distribution pallet is used which distributes a load while it is placed on the pallet. In an automated warehouse system that uses such a distribution pallet, the distribution pallet has various shapes, and the distribution pallet may be handled in the automated warehouse. In that case, as shown in FIG. 5, a warehouse pallet 19 is used, and the warehouse pallet 19 is used.
The distribution pallet 20 on which the goods 21 are placed may be placed and handled in an automated warehouse.

In the system for handling the distribution pallet 20 placed on the warehouse pallet 19 as described above, when the distribution pallet 20 is placed on the warehouse pallet 19, the distribution pallet 20 is prevented from protruding from the warehouse pallet. Place the distribution pallet 2 on the fork 11 of the unmanned vehicle 10.
The position of the distribution pallet 20 when picking 0 is shown in FIG.
In some cases, it may not be located at the center of the unmanned vehicle 10 (center of the warehouse pallet 19) as shown in FIG. In this case, although the distribution pallet cannot be picked by the conventional pallet picking method using the forklift type unmanned vehicle, the distribution pallet 20 placed on the warehouse pallet 19 is easily picked as follows in the pallet picking method of the present invention. be able to.

FIGS. 7A to 7E show a pallet 1 for a warehouse.
The center of the distribution pallet 20 on the top 9 is the unmanned vehicle 10.
FIG. 6 is a diagram for explaining a picking method of the distribution pallet 20 when the distribution pallet 20 is deviated from the center. In the figure, the warehouse pallet 19 and the distribution pallet 20 are shown in a front view when viewed from the front, and the unmanned vehicle 10 is shown in a plan view when viewed from above. First, the unmanned vehicle 10 is placed at a predetermined position in front of the loading platform 22 on which the warehouse pallet 19 on which the distribution pallet 20 is placed.
Stops and raises the fork 11 to the fork insertion level in the vertical direction, and then activates the insertion port searchers 16a and 16b.

In this state, as shown in FIG. 7 (a), there is a beam 20b of the distribution pallet 20 in front of the left fork 11, a fork insertion port 20c in front of the right fork 11, and an insertion port searcher. When 16b-carred 20b is detected and the insertion port searcher 16a detects the fork insertion port 20c, only the right fork 11 is moved to the outside as shown in FIG. ) As shown in FIG.
When the a mark 20b is detected, the right fork 11 is stopped.

In this state, as shown in FIG. 7 (d), the left and right forks 11, 11 are moved inward, and the left and right insertion port searchers 16a, 16b detect the fork insertion ports 20c, respectively. When the horizontal fork insertion level is reached as shown in (e), the unmanned vehicle 10 is moved forward, and both forks 11, 1 are moved.
The distribution pallet 20 is picked by inserting 1 into the fork insertion port 20c of the distribution pallet 20 and raising the forks 11, 11 by a predetermined amount.

In the above embodiment, the forks 11, 1 are used as means for detecting the fork insertion opening of the pallet.
Although the insertion slot searchers 16a and 16b provided at the tip of No. 1 are used, the means for detecting the fork insertion slot of the pallet is not limited to this. For example, the unmanned vehicle 10 can be searched for a large number of insertion slots. It is also possible to arrange the vessels in an array and detect the fork insertion port of the pallet from the output, the point is to detect the fork insertion port with some insertion port search means and to detect each fork based on the output. It suffices that the fork can be moved in the lateral direction and the lateral position of the fork can be positioned at the lateral insertion level.

When the distribution pallet 20 placed on the warehouse pallet 19 is picked as described above,
As shown in FIG. 8A, when the center of the distribution pallet 20 is displaced from the center of the unmanned vehicle 10, the distribution pallet 20
When unloading the pallet to the destination station, the distribution pallet 20 cannot be laid down at the fixed position of the station. Therefore, in the present embodiment, as shown in FIG. 8B, after the distribution pallet 20 is picked, the left and right forks are so arranged that the center between the left and right forks 11, 11 coincides with the center of the unmanned vehicle 10. 11 and 11 are moved. This allows the distribution pallet 20 to be lowered to a fixed position in the station.

[0030]

As described above, according to the present invention, the following excellent effects can be obtained. (1) According to the invention described in claim 1 or 2, the fork insertion port is searched by the insertion port search means, and the two forks are positioned so as to be in the lateral insertion level, and the fork is positioned. Since it is inserted into the fork insertion slot, the excellent effect that picking can be performed even with pallets of different shapes.

(2) According to the third aspect of the invention, since the vertical insertion level of the fork is set from the running ground or floor of the unmanned vehicle, the tire pressure of the unmanned vehicle or the ground or floor of the unmanned vehicle is set. Regardless of unevenness, you can always set a constant fork vertical insertion level.

(3) According to the invention described in claim 4, after the pallet is placed on the two forks, the two forks are moved laterally so that the center of the forks and the unmanned vehicle are moved. Since it is possible to match the center with the center, it is possible to lower the pallet to a predetermined position of the destination even when picking a pallet whose center is displaced from the center of the unmanned vehicle.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a forklift type unmanned vehicle used in a picking method of the present invention.

FIG. 2 is a diagram showing a flow of pallet picking operation by the forklift type unmanned vehicle of the present invention.

FIG. 3 is a diagram illustrating a pallet picking operation of the present invention.

FIG. 4 is a diagram illustrating a pallet picking operation of the present invention.

FIG. 5 is a diagram showing a state in which distribution pallets are placed on a warehouse pallet.

FIG. 6 is a diagram showing a state in which a distribution pallet is placed on a warehouse pallet.

FIG. 7 is a diagram illustrating an example of picking operation of a distribution pallet according to the present invention.

FIG. 8 is a diagram illustrating an example of centering a pallet picked according to the present invention.

FIG. 9 is a diagram showing a schematic configuration of a forklift type unmanned vehicle used in a conventional picking method.

[Explanation of symbols]

 10 Unmanned vehicle 11 Fork 12 Load presence / absence detector 13 Upper level detector 15 Lower level detector 16a, b Insertion port searcher 17 Insert level setting device 18 Pallet 19 Warehouse pallet 20 Distribution pallet 21 Item 22 Receiving stand

Claims (4)

[Claims] 1. A pallet picking method using a forklift type unmanned vehicle equipped with a pallet picking fork, wherein the unmanned vehicle raises the fork to a vertical insertion level at a predetermined position facing the pallet. , Forward, insert the fork into the fork insertion port of the pallet, then raise the fork by a predetermined amount, place the pallet on the fork, then retract by a predetermined amount, and further move the fork to a predetermined lower level. In a pallet picking method using a forklift type unmanned vehicle for lowering and picking a pallet, the unmanned vehicle includes an insertion port search means for searching a fork insertion port of the pallet, and the fork is composed of two forks. Each of the forks is configured to be movable in the lateral direction. After elevating to the vertical insertion level, the insertion port search means searches for the fork insertion port, positions the two forks at the horizontal insertion level of the fork insertion port of the pallet, and then A pallet picking method for a forklift type unmanned vehicle, which is characterized by moving forward and inserting the fork into the fork insertion port. 2. The insertion port search means is provided at the tip of each of the two forks, and after the two forks are raised to the vertical insertion level, the forks are moved laterally. 2. The pallet for an unmanned forklift type pallet according to claim 1, wherein the forklift type unmanned vehicle is moved, and the both insertion port search means respectively detect the fork insertion ports of the pallet and insert the forks when the horizontal insertion level is reached. Picking method. 3. The pallet picking method for a forklift type unmanned vehicle according to claim 1, wherein the vertical insertion level is set from the traveling ground or floor of the unmanned vehicle. 4. After placing a pallet on the two forks, the two forks can be moved laterally so that the center between the forks and the center of the unmanned vehicle can coincide with each other. The pallet picking method by the forklift type unmanned vehicle according to claim 1, 2 or 3.