JPH0699117B2 - Fork slot forklift detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a space for a pallet, which is a slot for a fork of a forklift truck, is covered with a vinyl sheet by shrink packaging. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift fork detection device that can reliably detect a portion.

(Prior Art) Conventionally, in the first case, an emitter / receiver for emitting / receiving a light beam having an optical axis substantially parallel to the traveling surface is provided at the fork tip of a forklift, and the space from the palette is There is a configuration that detects the space portion of the pallet by utilizing the fact that the reflected light does not return. In the second case, a set of two emitters / receivers are mounted on the left and right sides of the fork of the forklift, and the optical axes of the emitters / receivers are located on the upper and lower edge boards. The output of the receiver that detects the space part of the pallet close to the upper and lower edge boards and receives the reflected light from the upper and lower edge boards is "high", and the light receiver corresponding to the space part There is a configuration in which it is determined that the plug-in is possible when all the outputs of are low.

(Problems to be Solved) In both of the above-mentioned first and second conventional techniques, when the reflected light does not return from the space portion of the pallet and the output of the corresponding light receiver is “low”, the fork is moved to the pallet. Since it is said that it can be inserted into the space, in the case of shoe-link packaging,
Since the space portion of the pallet is covered with the vinyl sheet, all the reflected light is returned and light can be received by the light receiver, and there is a problem that the space portion itself cannot be detected.

(Means for Solving Problems) In the present invention, racks having a plurality of storage shelves are arranged in a plurality of rows at predetermined intervals, and a forklift travels in a passage having the above-mentioned spacing as a passage width, and luggage is stored in the storage shelves. In the case of carrying in or carrying out luggage from the storage shelf, a reflective tape that efficiently reflects in all directions is attached to each of the plurality of beams forming the storage shelf, while the above-mentioned is attached to the tip of the fork of the forklift. Two photoelectric sensors that detect the right edge / upper edge (or left edge / upper edge) of the reflective tape and the left edge / lower edge (or right edge / lower edge) of the reflective tape separately are provided, and the fork raised to a predetermined height is re-installed. It is moved down at a very low speed, and the first focus when one of the two photoelectric sensors detects the right end / upper end (or left end / upper end) of the reflective tape during the lowering operation. Height h1
The second fork height h2 when the other photoelectric sensor detects the left end / lower end (or right end / lower end) of the above-mentioned reflective tape is stored, and the first fork height h1 and the first fork height h1 are stored. The second fork height h2 is calculated whether or not the difference is equal to a predetermined set value, and an arithmetic circuit that outputs an output signal only when they are equal to each other and an output signal from the arithmetic circuit are used to detect the first fork height. The above problem is solved as a configuration including a fork lift control circuit that lifts the fork only for a distance obtained by adding a predetermined set value to the height h1.

(Embodiment) An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a layout diagram of a warehouse in which a forklift equipped with the fork insertion port detection device of the present invention travels, and a plurality of storage shelves 1a.
A plurality of rows of racks 1 having the above are arranged at predetermined intervals.

The forklift 2 is provided between the rack 1 and the rack 1.
Runs. FIG. 2 is a front view of the rack, which is the rack 1 described above.
A reflective tape 3 that efficiently reflects in all directions is attached to each of the beams 1b of the storage shelf 1a. FIG. 3 is a side view of a forklift including an insertion port detection device provided in a forklift, FIG. 4 is a side view of the insertion port detection device, and FIG. 5 is a front view of the insertion port detection device. The mouth detection device 4 separately detects the right end / upper end (or left end / upper end) of the reflective tape 3 and the left end / lower end (or right end / lower end) of the reflective tape 3 at the end of the fork 2b of the forklift 2 2 The photoelectric sensor 4a, 4b is provided in an X shape, and the vehicle body of the forklift 2
The fork 2b, which has been raised to a predetermined height, is moved down to the 2a at a very low speed again, and during the lowering operation, the two photoelectric sensors
One of the 4a and 4b, for example, the photoelectric sensor 4a stores the first fork height h1 when the right end / upper end (or left end / upper end) of the reflective tape 3 is detected, and the other photoelectric sensor is stored. The difference between the first fork height h1 and the second fork height h2 is stored by storing the second fork height h2 when 4b detects the left end / lower end (or right end / lower end) of the reflective tape 3. Is calculated to be equal to a predetermined set value, and the output signal from the arithmetic circuit 5 which outputs an output signal only when they are equal to each other is used to determine the predetermined set value h3 for the first fork height h1. And a fork lift control circuit 6 that raises the fork 2b only for the distance obtained by adding. A known means that can detect the amount of elevation of the fork 2b can be detected by an encoder (not shown) rotated by a chain (not shown).

(Operation) The operation principle will be described with reference to FIG.

When the fork 2b is first raised to a predetermined height H and then lowered, when the fork 2b reaches the height of h1, one of the two photoelectric sensors 4a and 4b detects the right end and the upper end, and continues further. When it descends and the fork 2b reaches the height of h2, the other 1
Detects the left and bottom edges. These detection signals are applied to the arithmetic circuit 5 and the difference between them is calculated.

That is, ΔH = h1−h2 (1) Then, this difference ΔH is calculated whether ΔH = a (2) a: setting value is satisfied or not, and only when the formula (2) is satisfied. The fork 2b stops when the fork 2b rises and rises only a distance obtained by adding a predetermined height h3 to the height of h1.

(Effect) Because of the above-described configuration and operation, even if shrink-wrapped, the space effected by the fork insertion port of the pallet can be reliably detected, which is an industrial effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a layout diagram of a warehouse in which a forklift equipped with a fork insertion port detection device of the present invention travels, FIG. 2 is a front view of a rack, and FIG. 3 is a fork difference of the present invention. FIG. 4 is a side view of a forklift equipped with a slot detection device, FIG. 4 is a side view of the fork slot detection device, FIG. 5 is a front view of FIG. 4, and FIG. 6 is a fork slot detection device of the present invention. The operation principle diagram of is shown. 1 …… Rack 1a …… Storage rack 1b …… Beam 2 …… Forklift 2a …… Vehicle 2b …… Fork 3 …… Reflective tape 4 …… Fork slot detector 4a, 4b …… Photoelectric sensor 5 …… Calculation Circuit 6 ... Fork lift control circuit

Claims (1)

[Claims] 1. A rack having a plurality of storage shelves is arranged in a plurality of rows at predetermined intervals, and a forklift travels in a passage having the passage width as the passage to load a luggage into the storage shelves or a storage shelves. In the case of carrying out luggage from each of the plurality of beams forming the storage shelf, a reflective tape that efficiently reflects in all directions is attached, while the right end and the upper end of the reflective tape are attached to the tip of the fork of the forklift ( Alternatively, two photoelectric sensors for separately detecting the left end and the upper end) and the left end and the lower end (or the right end and the lower end) of the reflection tape are provided, and the fork raised to a predetermined height is again lowered at a slight speed, and the descending operation is performed. First fork height when one of the two photoelectric sensors detects the right edge / top edge (or left edge / top edge) of the reflective tape
The second value when h1 is memorized and the other photoelectric sensor detects the left end or the lower end (or the right end or the lower end) of the reflective tape.
Of the fork height h2 of the first fork height h2 is stored, and it is calculated whether or not the difference between the first fork height h1 and the second fork height h2 is equal to a predetermined set value, and an output signal is issued only when they are equal to each other. A fork insertion opening of a forklift including an arithmetic circuit and a fork lift control circuit for raising the fork only by a distance obtained by adding a predetermined set value to the first fork height h1 by an output signal from the arithmetic circuit. Detector