JP2002167193A - Cargo handling control device for forklift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cargo handling work controlling device for a forklift having excellent operability. SOLUTION: This cargo handling work controlling device for the forklift having a controller controlling a position of a working machine on the basis of a deviation between a target stopping position and an actual position is provided with a stopping position selecting and instructing means, by which a plurality of target stopping positions are stored, and from the stored target stopping positions, the target stopping position is selected by a selection means and instructed to the controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift cargo handling control device.

[0002]

2. Description of the Related Art A forklift 40 shown in FIG. 7 drives a pair of left and right front wheels 41, 41 and a pair of left and right rear wheels 42, 41.
It is a four-wheeled vehicle that steers 42. An inner rail 12 is disposed between a pair of left and right outer rails 11 erected at a front portion of a body frame 45 of the forklift 40 so as to be able to move up and down. 51 is mounted so as to be able to move up and down via a chain (not shown). Outer rail 11,
Numeral 11 is connected to the vehicle body frame 45 via a pair of left and right tilt cylinders 50, 50. When the operator operates the tilt lever 49, the tilt cylinder 50 is moved.
Are driven to expand and contract, so that the outer rails 11 and 11 are tilted. A piston rod of a lift cylinder 14 disposed on the back surface of the outer rails 11 is connected to the upper end of the inner rail 12. When an operator operates the lift lever 22, the lift cylinder 14 is driven to expand and contract to move the fork 13. It goes up and down.

[0003] In the forklift 40 described above, conventionally, the forklift 1 as a working machine at the time of cargo handling work is used.
Tilt horizontal control that can automatically set the posture of 3 horizontally
In many cases, simplification and simplification of the operation are achieved by an automatic positioning technique of the working machine such as an automatic lifting control capable of automatically controlling the lift height of the fork 13 to a predetermined set value. Here, a case of tilt horizontal control will be described with reference to FIG. 8 as an example of simplification and simplification of operation. The same components as those in FIG. 7 are described with the same reference numerals. A tilt cylinder 50 as a work machine actuator, and a tilt cylinder 5
Hydraulic piping is provided between the hydraulic pump 20 and the hydraulic pump 20 via an electromagnetic proportional valve 16 as a flow control valve for controlling expansion and contraction of the tilt cylinder 50. The hydraulic pump 20 is driven by an electric motor 21. One end P1 of the tilt cylinder 50 and a tilt rotation center P3 of the outer rail 11 are rotatably attached to the vehicle body frame 45.
The other end P2 of the tilt cylinder 50 is the outer rail 1
When the tilt cylinder 50 expands and contracts, the outer rail 11 tilts back and forth and the fork 13
Set the tilt angle of.

As a detector, a tilt angle detector 95 as a work implement position detector for detecting the actual tilt angle θa of the outer rail 11 is attached near the tilt rotation center P3. The tilt lever 49 that outputs a command to the electromagnetic proportional valve 16 is located near the center of rotation of the tilt lever 49.
Lever operation amount detector 2 for detecting lever operation amount Lev
4 are attached. The automatic command button 25 that is turned on when performing tilt horizontal control is attached to the grip portion 83 of the operation lever 49. When performing the tilt horizontal control, the automatic command button 25 is turned on or off by the operator to turn on or off the automatic command signal Sa.
Is output. A warning means 74 provided on an operation panel (not shown) provides a buzzer in response to a warning signal Ar input from a warning determination unit 75 to be described later when predetermined positioning accuracy cannot be obtained during tilt automatic horizontal control. Ring to alert the operator.

Next, the configuration of the controller 26 will be described. The controller 26 receives the automatic command signal Sa, the actual tilt angle θa, and the lever operation amount Lev, and outputs the electromagnetic proportional valve command value Sv and the warning signal Ar to the electromagnetic proportional control valve 1.
6 and the warning means 74. The controller 26 includes a target angle storage unit 73, a deviation value calculation unit 70, a command value calculation unit 71, a minimum value selection unit 72, and a warning determination unit 75.
have. The target angle storage unit 73 stores the target tilt angle θt in advance when the forklift 40 is shipped, and outputs the stored target tilt angle θt to the deviation value calculation unit 70. The deviation value calculation unit 70 calculates the deviation value E by subtracting the actual tilt angle θa from the target tilt angle θt, and calculates the deviation value E.
Is output to the command value calculation unit 71.

A command value calculating section 71 calculates an opening command value D with respect to a deviation value E shown on the horizontal axis by a calculation curve Cc and outputs the opening command value D to a minimum value selecting section 72. When the deviation value E becomes smaller than the allowable deviation value Es during the tilt horizontal control, the opening command value D changes to a zero value, the opening area of the electromagnetic proportional valve 16 is set to a zero value, and oil supply to the tilt cylinder 50 is performed. And the fork 13 is automatically stopped.

When the automatic command signal Sa is ON, the minimum value selecting section 72 provides the opening command value D and the lever command value VLev.
Is selected and output to the electromagnetic proportional control valve 16 as the electromagnetic proportional valve command value Sv. When the automatic command signal Sa is off, the lever operation amount Lev is output as it is to the electromagnetic proportional control valve 16 as the electromagnetic proportional valve command value Sv. The warning determination unit 75 outputs a warning signal Ar to the warning unit 74 when the deviation value E when the tilt horizontal control is completed and the expansion and contraction of the tilt cylinder 50 stops is not within the allowable range Δ.
The allowable range Δ is a range in which the deviation value E is equal to or more than a negative value and equal to or less than a positive value of the allowable deviation value Es.

When performing the tilt horizontal control, the operator turns on the automatic command button 25 while turning on the tilt lever 4.
When the fork 13 is operated in the direction in which the fork 13 approaches horizontal, the smaller one of the opening degree command value D and the lever operation amount Lev is selected by the minimum value selector 72 and output to the electromagnetic proportional control valve 16 as the electromagnetic proportional valve command value Sv. Is done. And the hydraulic pump 20
The oil is sent to the tilt cylinder 50 via the electromagnetic proportional control valve 16 and the fork 13 approaches the horizontal. At this time,
The deviation value calculator 70 of the controller 26 calculates a deviation value E between the target tilt angle θt and the actual tilt angle θa,
The opening command value D is calculated by the command value calculation unit 71 based on the calculated deviation value E. The calculated opening command value D is output to the minimum value selection unit 72. When the fork 13 approaches the horizontal and the deviation value E falls within the allowable range Δ, the opening command value D becomes zero, so that the extension and contraction of the tilt cylinder 50 stops. When the operator turns off the automatic command button 25 while observing the stop of the expansion and contraction of the tilt cylinder 50, the tilt horizontal control is completed.

[0009]

However, the above-mentioned prior art has the following problems. In the related art of tilt horizontal control, the forklift 40 is placed on a horizontal base before shipment, and the angle at which the fork 13 becomes horizontal is set as the target tilt angle θt. Since the target tilt angle θt is stored in the controller 26 in advance, as shown in FIG.
0 is a track 47 on a flat ground by tilt horizontal control.
When the fork 13 is to be loaded, the fork 13 has a tilt angle as shown by the dotted line. For this reason,
If the tilt horizontal control is used on a sloping ground, it becomes impossible to load and unload the truck 47 on a flat ground. Therefore, the operator has to carefully and manually position the fork 13 horizontally, which causes a problem that the operability is not good. In addition, when the forklift 40 is used for a long time, the frictional resistance of the support points P1 and P2 at both ends of the tilt cylinder 50 and the swing fulcrum P3 of the outer race 11 increases due to a change over time, and the movement of the tilt cylinder 50 is reduced. During the tilt horizontal control, the fork 13 may stop outside the allowable range Δ. For this reason, the fork 13 is positioned at an angle different from the preset target tilt angle θt, and the operator needs to manually correct the angle of the fork 13. In addition, every time the tilt horizontal control is performed, the warning signal Ar is output from the warning determination unit 75 to the warning unit 74 and the buzzer sounds, so that the operability is not good.

The present invention has been made in view of the above problems, and has as its object to provide a cargo handling control device for a forklift having excellent operability.

[0011]

In order to achieve the above object, a first aspect of the present invention provides a forklift having a controller for controlling the position of a working machine based on a deviation between a target stop position and an actual position. In the cargo handling control device of the above, a plurality of target stop positions are stored, and stop position selection instruction means for instructing the controller of a target stop position selected by the selection means from the plurality of stored target stop positions is provided.

According to the first invention, the stop position selection command means stores a plurality of target stop positions, selects one target stop position from the plurality of target stop positions by the selection means, and instructs the controller. . This makes it possible to easily select an arbitrary stop position by the selection means and control the position of the work implement by instructing the controller, and it is not necessary to manually position the work implement, so that excellent operability can be obtained.

According to a second aspect based on the first aspect, target stop position changing means for changing the target stop position is provided, and the stop position selection command means sets the actual position when the target stop position changing means is changed. It is configured to be stored as the target stop position.

According to the second invention, when the attached target stop position changing means is operated to change, the stop position selection command means stores the actual position when the target stop position changing means is operated to change as the target stop position. As a result, the target stop position can be easily changed and stored, so that it is not necessary to correct the target stop position each time, and excellent operability can be obtained.

According to a third aspect of the present invention, there is provided a cargo handling control device for a forklift including a controller for controlling a position of a working machine based on a deviation between a target stop position and an actual position. A stop position selection commanding means for calculating a target stop position by adding a reference position to the difference position selected by the selection means from the stored plurality of difference positions and instructing the controller is provided.

According to the third aspect, the stop position selection command means stores the reference position and a plurality of difference positions from the reference position, and calculates the target stop position by adding the reference position to the difference position selected by the selection means. Command to the controller. Normally, the work machine is positioned at the reference position, but when it is desired to temporarily position the work machine at a position other than the reference position, an arbitrary stop position can be easily selected by the selection means of the stop position selection command means. Also,
If the stop position deviates from the initial position due to a change over time or the like, changing only the reference position also changes all the stop positions, so that the change of the stop position can be completed in a short time and the operability is good.

According to a fourth aspect based on the third aspect, target stop position changing means for changing the target stop position is additionally provided, and the stop position selection command means sets the actual stop position when the target stop position changing means is changed. The difference from the reference position is stored as a difference position.

According to the fourth aspect, when the attached target stop position changing means is operated to change, the stop position selection command means determines the difference between the actual position and the reference position when the target stop position changing means is operated to be changed to the difference position. To be stored. This allows
Since the difference position can be changed and stored arbitrarily easily and in a short time, the stop position can be changed in a short time, so that excellent operability can be obtained.

A fifth invention is based on the third or fourth invention,
Reference position changing means for changing the reference position is provided, and the stop position selection command means stores the actual position when the reference position changing means is changed as the reference position.

According to the fifth aspect, when the attached reference position changing means is changed, the stop position selection command means stores the actual position when the changed reference position changing means is operated as the reference position. Thus, there is no need to call the dealer every time the reference position is displaced and have the user correct the displacement, and the user can correct the displacement on site, so that a forklift cargo handling control device having excellent operability can be obtained.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The same components as those in FIGS. 7 and 8 will be described with the same reference numerals. Here, the description of the same configuration as that described with reference to FIGS. 7 and 8 is omitted, and only a different configuration will be described. First, a first embodiment will be described with reference to FIGS. FIG. 1 shows a control block diagram. In FIG. 1, the target angle storage unit 73 in the controller 26 shown in FIG. 8 is replaced with a first stop angle selection command unit 80 provided on an operation panel (not shown), 80 is input with the actual tilt angle θa. Also,
A stop angle change command Ct is input to a first stop angle selection command means 80 from a stop angle change means 81 newly provided on the operation panel. The other configuration is the same as the configuration shown in FIG.
The first stop angle selection instructing means 80 has a selection switch 52 for selecting one from a plurality of target tilt angles θt stored by a method described later, and sets the target tilt angle θt selected by the selection switch 52 to a deviation value. Output to the arithmetic unit 70. The stop angle changing means 81 is, for example, a button, and when the on operation of the button is continued for a predetermined time or more, the first stop angle selection command means 80 sets the actual tilt angle θ when the stop angle changing means 81 is turned on.
a is stored as the target tilt angle θt. The selection switch 52 is set to the selected positions A, B, C,..., And a plurality of target tilt angles θt are stored at each position.

The operation and effect of this embodiment having the above configuration will be described. The selection position of the first stop angle selection command means 80 is set to A, and the operation lever 49 is operated to fork 1
3 is tilted to an arbitrary first stop angle θ1, and then the stop angle changing means 81 is turned on for a predetermined time or more, the first stop angle selection command means 80 moves the first stop angle θ1 to the selected position A.
Is stored. The second and third stop angles θ2,
The same method is used to store θ3. When positioning the fork 13 at the first stop angle θ1, the selection position A of the first stop angle selection command means 80 is selected. Then, the first stop angle θ1 stored at the selected position A is output to the deviation value calculator 70 as the target tilt angle θt. Next, when the operator operates the operation lever 49 in the direction in which the fork 13 approaches the first stop angle θ1 while turning on the automatic command button 25, the minimum value selection unit 72 determines the opening command value D and the lever operation amount Lev. The smaller signal is selected and output to the electromagnetic proportional control valve 16 as the electromagnetic proportional valve command value Sv. Then, when the fork 13 approaches the first stop angle θ1 and the deviation value E becomes smaller than the deviation allowable value Es, the expansion and contraction of the tilt cylinder 50 stops, and the tilt horizontal control is completed. When positioning at the second stop angle θ2, the first stop angle selection command means 80 is switched to the selection position B, and the operation lever 49 is operated in a direction approaching the second stop angle θ2 while the automatic command button 25 is turned on. .

As described above, the first stop angle selection instructing means 80
By switching the selection switch 52 and operating the stop angle changing means 81, a plurality of target tilt angles θt are stored, and the angle selected by the selection switch 52 is set to the target tilt angle θt, and the actual tilt of the fork 13 is set. Angle θ
control a. As a result, in the operation on a slope that differs from site to site, a plurality of stop angles at which the fork 13 becomes horizontal are stored in advance as values from the origin of the tilt angle as shown in FIG. , A stop angle corresponding to the inclination angle is selected and set as the target tilt angle θt. As shown in FIG. 3, the first and second stop angles θ1 and θ2 at the first site, and the third and fourth stop angles θ at the second site.
3 and θ4 can be easily set as the target tilt angles θt, and the operation of leveling the fork 13 on each slope is not required, so that a forklift cargo handling control device having excellent operability can be obtained.

Next, a second embodiment will be described with reference to FIGS. FIG. 4 shows a control block diagram of the present embodiment. FIG.
In the first embodiment, the first stop angle selection command means 80 of FIG. 1 showing the first embodiment is replaced with a second stop angle selection command means 85,
A horizontal stop angle changing means 82 is newly added to FIG. 1, and a horizontal stop angle change command Cs is input to the second stop angle selection command means 85 from the horizontal stop angle changing means 82. The other configuration is the same as the configuration shown in FIG. The second stop angle selection instructing means 85 has a selection switch 52 having a selection position 0 and a plurality of other selection positions, and sets the reference angle θr at the selection position 0 and the reference angle θr at the other plurality of selection positions. Each of the difference angles θs based on the angle θr is stored. As shown in FIG. 5A, the reference angle θr is an angle of the tilt angle from the origin, and a plurality of difference angles θs1,
θs2 and θs3 are angles of difference from the reference angle θr. The stop angle changing means 81 is, for example, a button, and when the on operation of the button is continued for a predetermined time or longer, the second stop angle selection command means 85 sets the actual tilt angle θa and the reference angle θr when the stop angle changing means 81 is turned on. Is stored as the difference angle θs.

The operation and effect of this embodiment having the above configuration will be described. A procedure for changing the difference angle θs in a state where the reference angle θr and the difference angle θs are already stored will be described. After setting the selection switch 52 of the second stop angle selection command means 85 to the selection position 1 and operating the operation lever 49 to tilt the fork 13 to the first stop angle θ1, the stop angle changing means 81 is moved for a predetermined time or more. When the turning-on operation is performed, a stop angle change command Ct is output from the stop angle changing means 81 to the second stop angle selection command means 85. Then, the second stop angle selection instructing means 85 stores the first difference angle θs1 of the difference angle between the reference angle θr already stored at the selected position 0 and the newly set first stop angle θ1 at the selected position 1. . The procedure is the same for the second and third stop angles θ2 and θ3 to be newly set, and the description thereof is omitted here.

When positioning the fork 13 at the first tilt angle θ1, the selection position 1 of the selection switch 52 is selected. Then, the sum of the first difference angle θs1 stored at the selected position 1 and the reference angle θr stored at the selected position 0 is calculated as the target tilt angle θt, and is output to the deviation value calculating unit 70. Next, the operator operates the automatic command button 2
5 while the fork 13 is turned on at the first stop angle θ1.
When the operation lever 49 is operated in a direction approaching the direction, the smaller value of the opening degree command value D and the lever operation amount Lev is selected by the minimum value selection unit 72 as in the first embodiment, and is set as the electromagnetic proportional valve command value Sv. Output to the electromagnetic proportional control valve 16. When the fork 13 approaches the first stop angle θ1 and the deviation value E becomes smaller than the deviation allowable value Es, the expansion and contraction of the tilt cylinder 50 stops, and the tilt horizontal control is completed. When positioning at the second and third stop angles θ2 and θ3, the procedure is the same as that for positioning at the first stop angle θ1, and the description is omitted here.

When changing the reference angle θr, the selection switch 52 of the second stop angle selection command means 85 is set to the selected position 0.
After the fork 13 is tilted to the 0th stop angle θ0 by operating the operation lever 49 and the horizontal stop angle changing means 82 is turned on for a predetermined time or more, the horizontal stop angle changing means 82 The command Cs is output to the second stop angle selection command means 85. Then, the second stop angle selection command means 85 stores the 0th stop angle θ0 as the reference angle θr at the selected position 0. When the reference angle θr is changed by Δθr, as shown in FIG. 5B, the first, second, and third difference angles θ
The first, second, and third stop angles θ1, 2, and 3 move in parallel by the change Δθr of the reference angle θr while s1, θs2, and θs3 hold the values before the change.

As described above, the second stop angle selection instructing means 85
Switches the selection switch 52 and sets the stop angle changing means 8
By operating one or the horizontal stop angle changing means 82, the reference angle θr or the plurality of difference angles θs are changed and stored.
Further, the second stop angle selection command means 85 is provided with the selection switch 5
The target tilt angle θt is obtained by adding the difference angle θs corresponding to the selected position of No. 2 to the reference angle θr, and is output to the deviation value calculation unit 70 to control the tilt angle of the fork 13. In the present embodiment, unloading between a plurality of racks as shown in FIG.
In the loading operation, when the traveling road surface of the forklift 40 is horizontal in the second rack, but is inclined in the first and third racks, the positioning position of the fork 13 is significantly different from the initial position due to aging or the like. The effect is great when it comes. That is, the angle at which the actual tilt angle θa becomes horizontal is stored as the reference angle θr at the selected position 0 of the second stop angle selection commanding means 85, and the difference angle θs1 is selected at the selected position −1 for the first rack. Angle difference θs2
Are respectively stored. At the time of the work, the fork 13 is switched to the selected position -1,0,1 at the first, second, third rack position.
Insert horizontally into each rack. If the positioning position of the fork 13 is different from the initial position due to a change over time,
The fork 13 cannot be inserted horizontally into each rack. At this time, at the second rack position, the second stop angle selection instructing means 85
Is set to the selection position 0, the fork 13 is manually operated to level the level, and the angle is stored as the reference angle θr of the selection position 0. Then, the first and second
The stop angles θ1 and θ2 are also corrected by the change of the reference angle θr, so that a normal tilt angle can be obtained.

As described above, only by changing the reference angle θr, a plurality of stop angles can be corrected at once, and it is not necessary to manually correct the tilt angle of the fork 13 for each rack.
A forklift cargo handling control device having excellent operability is obtained.

In the first and second embodiments, the tilt horizontal control has been described as an example. However, the first and second tilt control may be used for position control of an attachment such as a lift / lift control or a rotary clamp.
Similar effects can be exerted by applying the embodiment.

According to the present invention, the stop position selection command means stores a plurality of target stop positions, selects one target stop position from the plurality of target stop positions by the selection means, and instructs the controller. The controller controls the position of the work implement based on the deviation between the commanded target stop position and the actual position. This makes it possible to easily select an arbitrary stop position by the selection means and control the position of the work implement by instructing the controller, and it is not necessary to manually position the work implement, so that excellent operability can be obtained. The stop position selection command means stores the reference position and a plurality of difference positions from the reference position, calculates the target stop position by adding the reference position to the difference position selected by the selection means, and instructs the controller. You may. In this case, the work machine is usually positioned at the reference position.
Any stop position can be easily selected by the selection means of the stop position selection command means. Further, when the stop position deviates from the initial position due to a change over time or the like, changing only the reference position also changes all the stop positions, so that the stop position can be changed in a short time and the operability is good.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a first embodiment.

FIG. 2 is an explanatory diagram of a tilt angle set in the first embodiment.

FIG. 3 is an explanatory diagram of a tilt angle at different sites.

FIG. 4 is a control block diagram of a second embodiment.

FIG. 5 is an explanatory diagram of a reference angle and a difference angle set in a second embodiment.

FIG. 6 is an explanatory diagram of a tilt angle when working between a plurality of racks.

FIG. 7 is an explanatory diagram of a forklift.

FIG. 8 is an explanatory diagram of a conventional technique of tilt horizontal control.

FIG. 9 is an explanatory diagram of a tilt angle of a fork on an inclined ground.

[Explanation of symbols]

11: outer rail, 12: inner rail, 13: fork, 14: lift cylinder, 16: solenoid proportional valve, 20
... Hydraulic pump, 21 ... Electric motor, 22 ... Lift lever, 24 ... Lever operation amount detector, 25 ... Automatic command button, 2
6 Controller, 40 Forklift, 41 Front Wheel, 42 Rear Wheel, 45 Body Frame, 47 Truck, 49 Tilt Lever, 50 Tilt Cylinder, 51
... finger board, 52 ... selection switch, 70 ... deviation value calculation unit, 71 ... command value calculation unit, 72 ... minimum value selection unit, 7
3 Target angle storage unit 74 Warning unit 75 Warning determination unit 80 First stop angle selection command unit 81 Stop angle changing unit 82 Horizontal stop angle changing unit 83 Grip unit
85: second stop angle selection command means, 95: tilt angle detector, Ar: warning signal, Ct: stop angle change command, Cs: horizontal stop angle change command, E: deviation value, Es: allowable deviation value, S
a: automatic command signal, Lev: lever operation amount, Sv: electromagnetic proportional valve command value, D: command value, Δ: allowable range, θa: actual tilt angle, θt: target tilt angle, θr: reference angle, θ
1, θ2: first and second stop angles, θs1, θs2: first,
2 difference angle.

Claims (5)

[Claims] 1. A cargo handling control device for a forklift equipped with a controller for controlling a position of a working machine based on a deviation between a target stop position and an actual position, wherein the plurality of target stop positions are stored, and the stored plurality of target stop positions are stored. And a stop position selection instructing means for instructing the controller of a target stop position selected by the selection means from the following. 2. The cargo handling control device for a forklift according to claim 1, further comprising a target stop position changing means for changing a target stop position, wherein the stop position selection command means changes the target stop position when the target stop position changing means is operated. A cargo handling control device for a forklift, wherein an actual position is stored as a target stop position. 3. A cargo handling control device for a forklift having a controller for controlling a position of a work machine based on a deviation between a target stop position and an actual position, wherein the reference position and a plurality of difference positions from the reference position are stored. A forklift loading / unloading control device comprising stop position selection command means for calculating a target stop position by adding a reference position to a difference position selected by the selection means from a plurality of stored difference positions and instructing the controller. 4. The cargo handling control device for a forklift according to claim 3, further comprising a target stop position changing means for changing a target stop position, wherein the stop position selection command means changes the target stop position changing means. A forklift cargo handling control device that stores a difference between an actual position and a reference position as a difference position. 5. The cargo handling control device for a forklift according to claim 3, further comprising a reference position changing means for changing a reference position, wherein the stop position selection command means is configured to execute the operation when the reference position changing means is changed. A forklift cargo handling control device characterized by storing a position as a reference position.