JP2008087891A - Fork lift vehicle and method for turning the fork lift vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fork lift vehicle allowing an operator to uniformly determine a turning start position every time and to provide a method for turning the fork lift vehicle. <P>SOLUTION: This fork lift vehicle is provided with a turning instructing means 30 for indicating start timing of turning operation to turn the fork lift vehicle 1 up to a predetermined position to the operator of the fork lift vehicle during running of the fork lift vehicle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a forklift vehicle suitable for traveling in a place where a turning operation is required in a cargo handling operation and a method for turning a forklift vehicle.

Forklift trucks are one of the forklift trucks that handle loading and unloading and transporting cargo in warehouses.
When taking out the load stored in the fixed shelf with this forklift truck, the operator (or operator) first runs the forklift truck along the passage arranged in the warehouse and lays it on the target fixed rack. Next, change the direction at the position of the fixed shelf (as a specific example, turn 90 °) and place the front so that the load can be transferred to the fixed shelf, and then fork to the desired load height The fork is moved up and down and the fork lift truck is moved forward or the fork is pushed forward to insert the fork into the insertion port of the pallet and take out the load.

In general, the operation of forklift trucks largely relies on the operator's intuition. For this reason, a difference occurs in the number of turnovers of the forklift truck, the adjustment time of the fork height, and the like according to the operation experience of the operator. Therefore, various operation support devices have been studied for the purpose of assisting the operation of the operator in each operation process of cargo handling.
For example, a device for preventing a collision with an obstacle during a right turn or a left turn when traveling in an aisle is used, and the vehicle is configured to irradiate a light on the traveling road surface of a virtual vehicle locus during the turn. (Refer to Patent Document 1).

  There is also a support device when a forklift truck cannot be attached to the front so that the intended load can be transferred after turning 90 °. A forklift vehicle is provided with a mechanism called a side fork shift, and is a device that corrects the position of the fork on the front side so that the target load can be transferred by sliding the fork left and right (see Patent Document 2).

  Furthermore, there is a device that supports the positioning operation of the fork height. In this apparatus, a projector is mounted on a forklift, and the height position is confirmed by relying on the irradiation position of the light beam (see Patent Document 3).

In addition, there is also a disclosure of a system that can load and unload luggage properly without being affected by a lateral shift in a tire traveling type moving shelf (see Patent Document 4).
JP 2001-199276 JP 11-171487 A Japanese Patent Laid-Open No. 2001-122598 Japanese Patent Laid-Open No. 2003-20102

  Of the operation steps of the forklift truck described above, if the forklift truck cannot be faced to the front so that the desired load can be transferred after turning 90 °, the forklift should be faced to the front. It can only be turned over many times, or it can be adjusted to the left and right using a side fork shift to align the fork with the front of the intended load. In the case of an operator with little experience in operation, it is difficult to attach a forklift truck face to face so that the intended load can be transferred at a time, and the above-described additional operations are inevitable. For this reason, the work time becomes long and the efficiency of the cargo handling work becomes poor, which is a problem. Furthermore, even a narrow passage tends to be difficult to switch back, and in that case, an increase in equipment cost is unavoidable due to the introduction of a side fork shift.

  Therefore, an object of the present invention is to provide a forklift vehicle and a method of turning the forklift vehicle that allows the operator to uniformly determine the turning start position regardless of operation experience.

In order to solve the above problems, the present invention is configured as follows.
One of the aspects of the forklift truck according to the present invention includes a turning instruction means for indicating a start timing of a turning operation for turning the forklift truck to a predetermined position to an operator of the forklift truck during the traveling of the forklift truck.

  For example, when the predetermined position is a position at which a load can be taken out by the forklift truck, the turning instruction means is set to a turning start position mark (for example, on a passage) fixed in advance on the traveling path of the forklift truck or in the vicinity of the traveling path. Or a tape affixed to a pallet or load, etc.) is preferably a projector arranged in a direction that illuminates the start timing of the turning operation.

As the forklift truck constituting the turning instruction means, a forklift truck capable of turning, for example, a reach type forklift truck capable of turning on the spot is suitable.
The projector is a line marker that is arranged to irradiate the line in a direction perpendicular to the traveling direction of the forklift truck and is fixed so as to illuminate the turning start position mark at the start timing of the turning operation. It is preferable.

  One aspect of the turning method of the forklift truck according to the present invention is that the forklift truck travels straight, reduces the traveling speed of the forklift truck, emits light from the forklift truck, and is placed at a predetermined position. When the light overlaps the mark, the forklift truck starts to turn, and the forklift truck is manipulated to take a predetermined turning locus.

  In the present invention, the start timing of the turning operation for turning the forklift truck to a predetermined position can be uniformly provided to the operator. For example, in the case of a line marker, the operator keeps lighting it before turning, and indicates to the operator when the light from the line marker overlaps with a pre-fixed turning start position mark. It becomes possible to uniformly determine that the timing is the timing of starting the turning, and the operator can start the turning operation without losing the timing.

  According to the present invention, the turning start timing can be uniformly determined by the operator. For this reason, if the turning operation is started at an appropriate timing (that is, an appropriate position) regardless of the operation experience of the operator, the forklift truck can be easily faced to the front side where the intended load can be transferred. It becomes like this. As a result, it becomes possible for an operator with little operational experience to easily face the forklift truck to the front side that enables the transfer of the target load, and the time for the cargo handling work is further shortened.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
Forklift trucks are generally used to load and unload loads placed on shelves in warehouses. An operator (also called an operator) operates an operation lever and a steering wheel, lays a forklift truck on a shelf loaded with a target load through a predetermined passage (travel path), and turns from that position ( For example, turn 90 degrees) and face the load at the bottom of the same row where the desired load is loaded. Then, the fork is moved up and down, or the forklift truck or the fork is moved forward to load the target load. When the load is already loaded, the load is unloaded on the shelf. The load is placed on a table called a pallet, and the fork is loaded into the pallet by inserting a fork into a pair of left and right insertion ports.

  The forklift truck of this embodiment is equipped with turn instruction means for indicating to the operator of the forklift truck the start timing of the turning operation for turning the forklift truck to a predetermined position while the vehicle is traveling. In particular, the turning instruction means is means for indicating the start timing of turning operation for turning the forklift truck from the position laid on the shelf to the position where the load placed on the shelf can be taken out. For example, the vehicle is operated such that the traveling speed is set to a predetermined constant speed so that a predetermined trajectory is taken at the time of turning, or the direction of the steering wheel of the forklift truck can be set to a predetermined angle.

  As the turning instruction means, for example, a light projector that irradiates light in a direction inclined with respect to the traveling direction of the forklift truck is configured in the forklift truck. Then, based on the turning trajectory of the forklift truck when the forklift truck is turned under a predetermined condition, a position (turning start position) for starting turning on the actual travel path is obtained, and the turning start is started. The irradiation range (for example, the irradiation range on the traveling road or the irradiation area near the traveling road) when the forklift truck arrives at the position is marked with, for example, a tape. As a result, when the forklift truck runs on the road and passes through the turning start position, the light projector mounted on the forklift truck illuminates the mark. It is determined that the forklift truck can be transferred to the position where the load can be transferred by starting the turning operation at an appropriate timing.

  Note that the turning instruction means is not limited to the above-described configuration, and any means that indicates an optimal position for starting the turning of the forklift truck to the operator during traveling may be used. May be. For example, an IC tag is placed in advance at the turning start position so that the information is detected by the forklift truck when the forklift truck passes through the position. Can be configured by sounding. Further, if the notification is made on the screen display, the warning message can be displayed on the screen instead of the sound.

Hereinafter, a case where a projector is used as the turning instruction means will be described.
(Example 1)
FIG. 1 is a perspective view of a forklift truck according to the present embodiment.

  In the figure, a reach-type forklift truck 1 of rear wheel traveling with a small turning radius is shown. Since this reach-type forklift truck 1 has a small turning radius, it can turn almost 90 degrees on the spot.

  A reach-type forklift truck (hereinafter simply referred to as a forklift truck) 1 shown in FIG. 1 has a lift device 10 that is also in the conventional configuration at the front of the forklift truck. The lift device 10 includes a pair of left and right masts 100, two upper and lower finger bars 101 that move up and down along the mast 100, a backrest 102 that is fixed to the finger bars 101 and prevents load collapse, and a target load. A pair of left and right forks 103 that lifts the pallet using the insertion port of the pallet, a lift cylinder 104 that moves the finger bar 101 up and down, a chain 105, a tilt cylinder (not shown) that tilts the fork 103, and the like. Further, in the figure, a pair of left and right front wheels 106 fixed in a straight-forward direction are looked partly on both sides of the pair of left and right forks 103. The front wheel is fixed so as to be rotatable in a straight direction.

  In the forklift truck 1 shown in the figure, an operation control unit 20 is configured at the rear thereof. The operation control unit 20 is equipped with a conventional control device that controls each part of the forklift truck 1. While being protected by the head guard 200, the operator (operator) controls the lift device 10 by operating the operation lever 201 and the steering, which are partially seen in FIG. Further, in the same figure, a rear wheel driven by a travel motor is formed in the lower part of the operation control unit 20, although it is not visible because it is covered with a protective cover 202. The rear wheels are configured to turn to the left and right with respect to the straight traveling direction by operating the operation lever 201 or the steering. By instructing the traveling speed to the control device via the operation lever 201 or the steering, the rotational speed of the traveling motor is controlled to the traveling speed, and the rear wheels rotate at the rotational speed. The forklift truck 1 shown in the figure further includes a laser marker, which is an example of the projector, and a power supply control device, which is an example of a lighting means for switching on / off the power of the laser marker, above each of the pair of left and right front wheels 106. The marker device 30 is mounted. When viewed from above, each marker device 30 irradiates (line irradiation) linear light M1 on an extension line of the axle of the front wheel 106 as shown in FIG.

FIG. 2 is a configuration diagram of the marker device 30.
A portion indicated by a broken line in the figure is a schematic configuration diagram of a conventional electric system for rotationally driving a rear wheel. Here, a travel motor 202 that rotationally drives the rear wheels, a tachometer 203 such as an encoder that measures the rotation of the travel motor 202, a travel speed instructed via the operation lever 201 and the steering wheel, and the tachometer A travel drive circuit 204 in the control device that controls the travel motor 202 based on the detected rotation information is shown.

  The marker device 30 includes a line marker 300 that forms the linear light M1 as described above on an irradiation object, and a power source that controls power supply to the line marker 300 based on a signal input from the tachometer 203. The controller 301 is configured.

  In the example of the figure, the power supply control device 301 causes the comparator 3010 to compare a preset threshold value (speed information threshold value) D1 and speed information D2 obtained by converting the output signal of the tachometer 203, for example, While the converted speed D2 is less than or equal to the threshold value D1, a conduction signal is output to the changeover switch 3011 and the power supply V is turned on to the line marker 300, and when the converted speed D2 is greater than the threshold value D1, a conduction signal is output to the changeover switch 3011. Without supplying the power to the line marker 300. As the power source V in the figure, the marker device 30 can be provided with a battery so that power is supplied from the battery, or the power supply (not shown) provided in the forklift truck 1 is supplied. There are various forms.

FIG. 3 is a configuration example of the line marker 300.
The line marker 300 in the figure uses a laser diode with good light straightness. The line marker 300 is supplied with the laser diode 3000, a driver 3001 that drives the laser diode 3000 by being supplied with the power source V, and the laser light oscillated from the laser diode 3000 is converted into planar light with good straightness. An optical system (condensing lens 3002 and rod lens 3003) is configured.

  When the power source V in FIG. 2 is conducted to the line marker 300, the laser light L1 oscillates from the laser diode 3000 under the drive of the driver 3001, passes through the optical systems 3002 and 3003, and the range shown by the shaded area in FIG. The light goes straight through the space. Although it cannot be read from this figure, light (shaded portion) L2 that travels straight in the space is light that spreads in a plane parallel to the paper surface in the example of FIG. For this reason, when this light is irradiated onto an object A such as a floor or a wall, linear irradiation lights L3 and L4 are formed on the object A as indicated by a thick line in FIG.

Next, an example in which cargo handling work is performed with the forklift truck 1 will be described.
In the forklift truck described below, the line marker 300 is installed so as to be irradiated in the right and left direction of the travel path perpendicular to the travel direction of the forklift truck. In this case, linear light extending in a direction perpendicular to the traveling direction is formed on an object such as a floor or a wall. The irradiation direction of the light of the line marker 300 in the vertical direction (vertical direction) is such that the linear light is fixed in advance on the traveling path or in the vicinity of the traveling path (for example, on the side of the traveling path, on a shelf, on a pallet, or on a load). It is set as the direction which irradiates the below-mentioned turning start position mark (for example, tape etc.).

  In this example, the threshold value (traveling speed threshold value) D1 of the power supply control device 301 is set to the maximum speed at which the forklift truck can turn with the minimum turning radius by design when the forklift truck turns. Shall.

FIG. 4 is a diagram schematically showing an example of the cargo handling process of the forklift truck 1 in the warehouse from above.
In the figure, as an example of the cargo handling process by the forklift truck 1, a process in the case of taking out the load 2 by the forklift truck 1 is shown. In this process, the forklift truck 1 is moved parallel to the shelf 3 and travels straight to the shelf 3-1 on which the target load 2-1 is placed (step 1), before reaching the target shelf 3-1. The forklift vehicle 1 is sufficiently slowed down and placed on the shelf 3-1, and once stopped, or the forklift vehicle 1 turns at the same low speed (turns right in the example in the figure). The process is divided into three processes: a process of attaching the load 2-1 to the take-out position (front) (process 2) and a process of lifting and lowering the target load 2-1 by moving the fork up and down (process 3). .

  In step 1, since the traveling speed of the forklift truck 1 is usually larger than the traveling speed threshold D1 set in the power supply control device 301, the power supply to the line marker 300 is cut off by the power supply control device 301, and the line marker From 300, laser light is not oscillated.

  In step 2, the traveling speed is sufficiently reduced. When the speed falls below a certain set speed, power is supplied to the line marker 300, and laser light oscillates. In this step, the operator always adjusts the speed so that the traveling speed of the forklift truck 1 is not more than the set speed D1 before turning. And at the time of turning, it operates so that a forklift truck may turn on the spot.

  In this process, if the fork is in a position that does not reach the insertion port of the pallet after the 90-degree turn is completed, for example, if the fork is pushed out and does not reach the insertion port of the pallet In the description, it is included in the position where the load can be taken out), and the forklift truck is moved forward to the reachable position.

FIG. 5 is a diagram showing the relationship of the turning trajectory from the turning start position to the turning end position of the forklift truck 1 in the above step 2.
In this example, the positional relationship between the turning start position and the turning end position when the forklift truck is turned 90 degrees with the minimum designed turning radius in the forklift truck is measured in advance, for example, by simulation. From the result, the turn start position for the forklift truck to face the load at the position where the load is actually placed is calculated backwards, and the line marker mounted on the forklift truck is the floor, shelf, pallet or load at the turn start position. For example, a mark is put on the line of light irradiated on the tape.

  In the forklift truck of this example, by design, when the center of the front of the load and the front wheel of the forklift truck are aligned side by side, if the 90-degree turn is started, the forklift truck and the load will face each other just in front. Become. Face-to-face means that the load can be picked up repeatedly, but more specifically, the pair of left and right forks 103 of the forklift truck and the pair of left and right fork outlets for lifting the load face each other. In this case, the forklift truck is switched again or the fork is slid in the left-right direction so that the pair of left and right forks fits in the pair of left and right forks on the pallet. There is no need to adjust so.

  In this example, the line marker 300 mounted on the forklift truck 1 is arranged so as to irradiate light L2 on the extension line of the axle of the front wheel. When a vertical line passing through the front center and a line passing through the axle of the front wheel intersect perpendicularly, it is necessary that the plane formed by these two lines be on a line intersecting the object. In this example, because the line marker is vertically adjusted so that light is emitted near the road, a straight line that descends vertically from the center of the front surface of the load intersects the road. The turning start position mark M2 is arranged at a position on the travel path. With this arrangement, where the axle of the front wheel of the forklift truck 1 coincides with the position where the turning must be started, the laser beam M1 emitted from the forklift truck 1 is the turning start position of the target load 2-1. The operator can easily know the turning start position (that is, the timing at which the turning operation is started during traveling) to overlap the mark M2 and move to the take-out position of the load 2-1.

In each drawing, the trajectory of the forklift truck 1 from the position slightly before starting the turn to the end of the turn is divided into four stages (from arrangement 1 to arrangement 4).
In the arrangement 1 in the figure, the traveling speed of the forklift vehicle 1 is reduced to the turning speed (in this example, the turning speed is 90 degrees with the minimum turning radius), and the speed is lower than the threshold value D1 of the power supply control device 301. This is an arrangement when the vehicle is traveling straight toward the vehicle. At this time, the changeover switch 3011 of the power supply control device 301 conducts the power supply V so as to supply power to the line marker 300, and is a plane perpendicular to the traveling direction of the forklift vehicle 1 and passing through the front wheel axle. The line marker 300 irradiates linear light M1 on an intersection line with a floor, a shelf beside a traveling path, a pallet, or a load.

  In the arrangement 2 in the figure, the front wheel axle and the turning start position mark M2 are arranged side by side, and the laser beam M1 emitted from the line marker 300 mounted on the forklift truck 1 overlaps the turning start position mark M2. Arrangement. At this time, the operator can visually confirm that the laser beam M1 has overlapped with the turning start position mark M2, and starts turning operation by opening the wheel fully through the operation lever 201 and the steering.

  Arrangement 3 in the figure is an arrangement of forklift trucks in the middle when the wheels are fully exhausted via the operation lever 201 and the steering. At this time, the operator operates the forklift truck so as to maintain the operation state so that the forklift truck takes a predetermined turning locus. Thus, the traveling direction of the forklift truck changes from the upper side of the figure to the direction of the load 2-1 through a predetermined locus.

  Arrangement 4 in the figure is an arrangement after turning 90 degrees. Thus, after the turn is completed, the center of the front surface of the load 2-1 is located in the middle of the pair of forks 103 when viewed from above, and the load can be taken out.

  Thus, the operator can visually check the overlap of the laser beam and the turning start position mark while the forklift truck is traveling. For this reason, a traveling method is possible in which the forklift vehicle starts turning when the laser beam overlaps the turning start position mark at the target load position, and the forklift truck can be used uniformly regardless of the operation experience of the operator. The forklift truck can face each other at a position where the pair of left and right forks of the vehicle and the pair of left and right forks of the pallet for lifting the load face each other.

  In the above configuration, since the laser beam is irradiated on the extension line of the axle, even when the distance between the forklift truck traveling on the traveling path and the shelf installed in parallel to the side of the forklift truck changes, the turning start timing does not change. Absent. When the irradiation direction of the laser beam is tilted forward in the traveling direction of the forklift truck, the timing at which the laser beam overlaps the turning start position mark changes according to the distance between the forklift truck and the shelf, so there is a distance from the shelf. What is necessary is just to drive a forklift truck at a fixed distance.

  Moreover, although the example in the case of turning with the minimum turning radius in the design of the forklift truck has been described above, the forklift truck may be turned with a turning radius larger than the turning radius. In this case, the turning speed and the angle at which the wheel is turned during turning may be determined in advance, and the turning start position and the placement position of the turning start position mark may be determined from the turning trajectory of the forklift truck at that time. Further, the threshold value of the power supply control device is set to be slightly higher than the turning speed so that the turning can be made without deceleration at the determined turning speed.

  Moreover, although the said forklift truck was a forklift truck which can be turned on the spot, it may be applied to a forklift truck which cannot be turned on the spot. In that case, the positional relationship between the turning start position and the turning end position when the forklift truck is turned 90 degrees with the minimum designed turning radius in the forklift truck is measured by, for example, simulation, and the actual load is calculated from the measurement result. The turn starting position for the forklift truck to face the load in front of the vehicle at the position where the vehicle is placed may be calculated backward.

  In the above, an example in which the power supply control device is used as an example of the lighting unit has been described. However, since this lighting unit may be configured to turn on or off a projector such as a laser marker, for example, an operator A simple configuration in which the projector is manually turned ON / OFF may be used.

  Thus, the turning start timing can be uniformly determined by the operator. For this reason, the forklift truck will start turning at an appropriate timing regardless of the operator's experience, and in front of the target load (or in front of the load if the load is on the shelf) Can be easily turned on. Thus, the forklift truck can be attached to the front of the target load with a small number of times, and the time required for the cargo handling work can be further reduced.

It is a perspective view of the forklift truck in a present Example. 2 is a configuration diagram of a marker device 30. FIG. 3 is a configuration example of a line marker 300. It is the figure which showed typically an example of the cargo handling process of the forklift truck 1 in a warehouse from upper direction. It is the figure which showed the relationship of the turning locus | trajectory from the turning start position of the forklift truck in the process 2 to the turning end position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reach type forklift truck 10 Lift apparatus 20 Operation control part 30 Marker apparatus 100 Mast 101 Finger bar 102 Backrest 103 Fork 104 Lift cylinder 105 Chain 106 Front wheel 200 Head guard 201 Operation lever 202 Protective cover M1 Linear light

Claims (5)

  A forklift vehicle having a turn instruction means for indicating a start timing of a turning operation for turning the forklift vehicle to a predetermined position to an operator of the forklift vehicle during traveling of the forklift vehicle. The predetermined position is a position where a load can be taken out by the forklift truck,
The turning instruction means is a projector disposed in a direction in which a turning start position mark fixed in advance in the vicinity of the traveling path of the forklift truck or in the vicinity of the traveling path is illuminated with the start timing of the turning operation.
The forklift vehicle according to claim 1. The projector is a line marker that is arranged so as to irradiate a line in a direction perpendicular to the traveling direction of the forklift truck and is fixed so as to illuminate the turning start position mark at the start timing of the turning operation.
The forklift vehicle according to claim 2.   The forklift truck according to claim 1 or 2, wherein the forklift truck is a reach type forklift capable of turning on the spot. A forklift car turning method,
Running the forklift car straight ahead,
Reduce the traveling speed of the forklift truck,
Irradiate light from the forklift truck,
The forklift truck starts turning when the light overlaps the turning start position mark arranged at a predetermined position,
Manipulate the forklift truck to take a predetermined turning trajectory;
A turning method of a forklift truck characterized by the above.