JPH075271B2 - Method and apparatus for moving fork of unmanned forklift - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a fork moving method and apparatus for an unmanned forklift.

(Prior Art and Problems) Conventionally, an unmanned forklift has been used for transporting loads, but when unloading a load on a shelf (pallet mounting table) inclined to the front with respect to the floor, the fork is used. If the fork is moved forward with respect to the pallet hole that is placed on the shelf and tilted to the front while being fixed at a certain inclination angle and height, the fork will be caught in the pallet hole and the luggage may be damaged or unattended. There was a risk of damaging the forklift.

An object of the present invention is to solve the above problems and to provide an unmanned forklift truck capable of smoothly moving a fork in a hole of a pallet inclined forward and backward.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, the first aspect of the present invention is that a fork vertically moves, tilts, and moves back and forth in a hole of a pallet that tilts back and forth as a series of operations. The gist is a fork moving method of an unmanned forklift in which the fork is moved by performing the operation.

A second aspect of the invention is a vertical movement means for moving the fork up and down, a tilting means for tilting the fork, a front-back movement means for moving the fork in the front-back direction, and a lift position detection for detecting the lift position of the fork. Means, inclination angle detection means for detecting the inclination angle of the fork, front-rear position detection means for detecting the position of the fork in the front-rear direction, detection signals of the elevation position detection means, inclination angle detection means, and front-rear position detection means Based on the above, an unmanned forklift having a vertical movement means, a tilting means, and a forward-backward movement means, and a movement control means for moving the fork up and down, tilting, and moving back and forth in a hole of a pallet tilted forward and backward. Its fork moving device is the main point.

(Operation) According to the first aspect of the present invention, the fork can be moved in the hole of the pallet that tilts back and forth by performing up and down movement, tilting, and back and forth movement as a series of operations.

According to the second aspect of the invention, the movement control means controls the vertical movement means, the inclination means, and the front-back movement means based on the detection signals of the lift position detection means, the inclination angle detection means, and the front-back position detection means. Up and down, tilt and move back and forth to move the fork into the hole in the pallet that tilts back and forth.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a vehicle body frame 2 of an unmanned forklift 1 supports an outer mast 4 so as to be tiltable in the front-rear direction via a bearing tube (not shown) attached to an axle of front wheels 3 on the front side. Tilt cylinder 5 as tilting means
The base end portion of the cylinder 5 is rotatably connected to the upper surface of the front portion of the vehicle body frame 2, and the tip end of the piston rod 5a of the cylinder 5 is rotatably connected to the outer surface of the outer mast 4. Therefore, when the outer mast 4 is in the upright position shown in FIG. 1, when the piston rod 5a of the tilt cylinder 5 is retracted, the outer mast 4 is tilted rearward, and conversely the rod 5a is extended. The outer mast 4 is tilted forward.

A pair of left and right lift cylinders 6 as vertical moving means are fixedly mounted on the rear portion of the outer mast 4, and a tip of a piston rod 6a thereof is fixed to an upper portion of a rear surface of an inner mast 7 which is mounted inside the outer mast 4 so as to be vertically movable. There is. A lift bracket 8 is provided on the inner surface of the inner mast 7 as shown by a broken line in FIG.
The fork 11 is attached to the bracket 8 via the upper and lower finger bars 9 and 10.

A chain wheel 12 is rotatably supported inside the upper part of the inner mast 7. One end of the chain wheel 12 is connected to the upper part of the cylinder body of the lift cylinder 6 and the other end is connected to the lift bracket 8. Lift chain 13
Is hung. Therefore, when the piston rod 6a of the lift cylinder 6 is expanded and contracted in the vertical direction, the inner mast 7 and the chain wheel 12 are moved up and down, and the fork 11 is moved up and down through the lift chain 13 at a speed twice that of the inner mast 7. Be moved.

A lift position detecting device 14 as a lift position detecting means is connected to the chain wheel 12, and this lift position detecting device 14 uses a rotary encoder in the present embodiment to determine the rotation direction and the rotation amount of the chain wheel 12. By detecting, the lift position of the fork 11 is detected.

Further, the tilt cylinder 5 is provided with a tilt angle detecting device 15 as a tilt angle detecting means.
Is a piston rod 5a of the tilt cylinder 5 in this embodiment.
A potentiometer that is linked to the expansion and contraction movement of the piston rod 5a is used to detect the expansion and contraction amount of this piston rod 5a.
The tilt angle of 4, 7 (fork 11) is detected.

As shown in FIG. 2, an optical sensor 16 composed of a light emitting diode and a phototransistor is arranged on the tip end surface of the fork 11 so that the light emitting diode emits light forward and the reflected light is emitted. Phototransistor detects. A loading position detection device 17 is provided on the side surface of the upright portion 11a of the one fork 11. In the loading position detecting device 17, a contact bar 17b is rotatably supported by a base 17a thereof, and the contact bar 17b is urged forward by a spring 17c. And base 17
A limit switch is provided on a to detect that the contact bar 17b is rotated backward by a predetermined amount or more, and a fork 11 to be described later by the fork 11 by the detection operation of the limit switch.
Detects that it has been inserted all the way into hole 27.

Next, the electrical configuration of the fork moving device of the unmanned forklift will be described with reference to FIG.

A microcomputer 18 as a movement control means includes a central processing unit (hereinafter referred to as CPU) 19, a program memory 20 including a read-only memory (ROM), and a work memory 21 including a readable and rewritable memory (RAM). It consists of The CPU 19 is adapted to execute various arithmetic processing including movement control of the fork 11 based on the control program stored in the program memory 20.

In this embodiment, a pulse encoder provided on the rotating shaft of the wheel is used as the traveling distance detecting device 22 as the front-rear position detecting means, and the CPU 19 inputs a signal from the traveling distance detecting device 22 to detect the traveling distance of the vehicle. Further, the CPU 19 detects the lift position and the tilt angle of the fork 11 based on the signals from the lift position detecting device 14 and the tilt angle detecting device 15. further,
The CPU 19 detects the reception of the reflected light by the signal from the optical sensor 16 and also detects that the fork 11 is inserted into the hole of the pallet 27 described later by the signal from the loading position detecting device 17.

The CPU 19 is connected to a traveling motor 24 as a forward / backward moving means via a traveling motor drive circuit 23, and the CPU 19 drives and controls the traveling motor 24 to move the vehicle (fork 11) back and forth. . Further, a tilt cylinder drive circuit 25 and a lift cylinder drive circuit 26 are connected to the CPU 19,
The tilt cylinder 5 and the lift cylinder 6 are controlled by driving and controlling these driving circuits 25 and 26.

Explaining the loading place of the luggage by the unmanned forklift 1 (station of the unmanned forklift 1), as shown in FIG. 4, the pallet carrier 28 is inclined forward and a plurality of rollers 29 are provided. Then, the pallet 27 on which the load W is placed is conveyed on the rollers 29, is stopped at the end of the pallet conveyance table 28, and is in a state of waiting for conveyance by the unmanned forklift 1. In FIG. 4, the stop member for the pallet 27 at the end of the pallet carrier 28 is omitted. A reflecting mirror 30 is arranged at a predetermined elevation position on the leg portion 28a of the pallet carrier 28.

Inclination angle of this pallet 27 (Inclination angle of pallet carrier 28)
Is previously stored in the program memory 20 of the unmanned forklift 1.

Next, the operation of the fork moving device of the unmanned forklift configured as above will be described.

The unmanned forklift 1 is guided by a guide wire, and as shown in FIG. 4, when the pallet 27 conveyed to the end of the pallet carrier 28 is approached to a predetermined distance position, the unmanned forklift 1 is stopped. . Then CPU1
Reference numeral 9 drives the lift cylinder 6 to raise the fork 11 from the low lift position for traveling until then while maintaining the horizontal position. Then, as shown in FIG. 5, when the optical sensor 16 detects the light reflected by the reflecting mirror 30 in the fork raising operation, the CPU 19 drives the tilt cylinder 5 to change the inclination angle of the fork 11 from the horizontal position up to that point in advance. The inclination angle of the fork 11 is detected by the inclination angle detection device 15 so as to be equal to the stored inclination angle of the pallet 27 (the inclination angle of the hole 27a of the pallet 27), and the angle is changed.

Next, as shown in FIG. 6, the CPU 19 drives the traveling motor 24 to move forward so as to approach the pallet 27, controls the lift cylinder 6 to raise the fork 11, and further moves the fork 11 to the pallet 27. This operation is continued even after the insertion into the hole 27a. At this time, the fork 11 is moved such that the inclination angle of the hole 27a of the pallet 27 becomes equal based on the amount of movement in the front-rear direction detected by the traveling distance detection device 22 and the detection of the lift position by the lift position detection device 14. .

In this way, the fork 11 is moved in the hole 27a of the pallet 27 while maintaining the same inclination angle. And CPU19
When the loading position detection device 17 detects that the fork 11 has been inserted all the way, the fork 11 is lifted, the pallet 27 is lifted, and the pallet 27 is conveyed to a predetermined moving position.

As described above, in the present embodiment, the fork 11 is tilted to the hole 27a of the pallet 27 that is tilted at the predetermined lifting position by the detection of the reflecting mirror 30 so as to be equal to the tilt angle, and then the fork 11 is moved forward and the fork is moved. 11 is moved upward, that is, the fork 11 is vertically moved, tilted, and moved back and forth as a series of operations, so that the fork 11 can be smoothly inserted into the hole 27a of the pallet 27 inclined to the front side without forcibly touching the hole 27a. Can be crowded.

The present invention is not limited to the above-described embodiment, but in the above-described embodiment, when the fork 11 is moved in the hole 27a of the pallet 27, the traveling operation and the raising operation are simultaneously performed. As shown, the same moving operation of the fork 11 may be performed by separately performing the traveling operation and the raising operation. That is, first, the fork 11 is moved forward (reference point P1 → P2), and then the fork 11 is moved upward (reference point P2
→ P3), and further move the fork 11 forward (reference point
P3 → P4).

Further, in each of the above-described embodiments, the inserting operation of the pallet 27 of the fork 11 into the hole 27a of the fork 11 has been described. However, as shown in FIG. 8, the pallet 27 carried by the unmanned forklift 1 is inclined rearward. When the fork 11 is removed from the hole 27a of the pallet 27 (loading) after being placed on the pallet transfer table 31, the operation reverse to the operation of each of the above embodiments may be performed.

Furthermore, in each of the above embodiments, the fork 11 was moved back and forth while the vehicle was running, but in a reach type unmanned forklift, the fork 11 may be moved back and forth by performing a reach operation. Further, in the above embodiment, the fork 11 is moved up from the low lift position for traveling, and then the reflecting mirror is moved.
The fork 11 was tilted so as to be equal to the inclination angle of the pallet 27 when it reached the predetermined lift position detected by 30, but the inclination angle was changed when the unmanned forklift 1 traveled to the front position of the pallet 27. After that, it may be moved up.

EFFECTS OF THE INVENTION As described in detail above, according to the present invention, an excellent effect that the fork can be smoothly moved into the hole of the pallet inclined forward and backward is exhibited.

[Brief description of drawings]

FIG. 1 is an overall view of an unmanned forklift in a fork moving device for an unmanned forklift embodying the present invention,
FIG. 2 is a perspective view of a fork, FIG. 3 is an electric block diagram showing an electric configuration of a fork moving device of an unmanned forklift, and FIG. 4 is a diagram for explaining the action of the fork moving device of the unmanned forklift. FIG. 6 is a diagram for explaining the action of the fork moving device of the unmanned forklift, FIG. 6 is a diagram for explaining the action of the fork moving device of the unmanned forklift, and FIG. 7 is a diagram for explaining another example. 8
The figure is a figure for demonstrating another another example. 5 is a tilt cylinder as tilting means, 6 is a lift cylinder as up-and-down moving means, 11 is a fork, 14 is a lift position detecting device as a lift position detecting means, and 15 is a tilt angle detecting device as a tilt angle detecting means. Reference numeral 18 is a microcomputer as movement control means, 22 is a travel distance detection device as front-back position detection means, 24 is a traveling motor as front-back movement means, 27 is a pallet, and 27a is a hole in the pallet.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiyuki Terada 2-chome, Toyota-cho, Kariya city, Aichi Stock company Toyota Industries Corporation (72) Inventor Kenji Hasegawa 2-chome, Toyota-cho, Kariya city, Aichi stock Company Toyota Industries Corporation (72) Inventor Takayuki Matsui 2-chome Toyota Town, Kariya City, Aichi Stock Company, Toyota Industries Corporation (72) Yoshitaka Kato 2-chome Toyota Town, Kariya City, Aichi Shares Company Toyota Industries Corporation (72) Inventor Yoshiyuki Fujita 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Yasuo Kuchiwaki 1, Toyota Town, Aichi Prefecture Toyota Motor Corporation (( 72) Inventor Katsuya Ichida 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Satoshi Suzuki Jiichi, Inazawa, Aichi Prefecture, 2-27-18-302 (56) References JP-A-59-82299 (JP, A) JP-A-62-212300 (JP, A) JP-A-58-100099 (JP-A) )

Claims (2)

[Claims] 1. A fork moving method for an unmanned forklift, wherein the fork is moved by vertically moving, tilting, and moving the fork in a hole of a pallet that tilts forward and backward as a series of operations. 2. A vertical movement means for moving the fork up and down, a tilting means for tilting the fork, a front-back movement means for moving the fork in the front-rear direction, and a lift position detecting means for detecting a lift position of the fork. An inclination angle detecting means for detecting an inclination angle of the fork, a front and rear position detecting means for detecting a position of the fork in the front and rear direction, and a detection signal of the lift position detecting means, the inclination angle detecting means and the front and rear position detecting means. Of the unmanned forklift truck, which is provided with a movement control means for controlling the vertical movement means, the tilting means, and the forward / backward movement means to move the fork up / down, tilted, and moved back and forth to move in the hole of the pallet inclined forward and backward. Fork moving device.