JPH115697A - Cargo handling control device for cargo handling vehicle - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When a lifting unit is lifted to a lift upper limit height determined on the basis of a load, the lifting operation is automatically stopped and the stability of the cargo handling vehicle is reduced. It is an object of the present invention to provide a cargo handling control device for a cargo handling vehicle that prevents the problem. The cargo handling control device for a cargo handling vehicle includes a lifting height detection unit that detects a lifting height of a lifting unit, a load detection unit that detects a load of a load placed on the lifting unit, and the lifting unit includes: A lifting control means for automatically stopping the lifting operation of the lifting / lowering unit when the lifting is performed to a lifting upper limit height determined based on the load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cargo handling control device for improving the safety of work in a cargo handling vehicle such as a forklift.

[0002]

2. Description of the Related Art Conventionally, when a forklift lifts a fork to perform a cargo handling operation, the upper limit of the lift is determined based on the load of the load placed on the fork, and the lift is determined. Although the operator is cautioned not to lift the fork beyond the high upper limit height, unless the operator intentionally stops lifting the fork at the upper height limit. The fork exceeds the upper limit of the lift.

[0003]

In the above-mentioned conventional forklift, the upper limit of the height of the lift is determined based on the load, and attention is paid to the operator so as not to carry out the cargo work beyond the upper limit of the height of the lift. However, this may not always be observed, and the stability of the forklift is significantly reduced when heavy forklifts are placed on the fork and lifted to a height above the maximum height. there's a possibility that. Therefore, according to the present invention, when a lifting portion such as a fork is lifted to the upper limit of the lifting height, the lifting of the lifting portion is automatically stopped to prevent the stability of the loading vehicle from deteriorating. It is an object of the present invention to provide a cargo handling control device.

[0004]

According to a first aspect of the present invention, there is provided a cargo handling control device for a cargo handling vehicle, comprising: a lifting height detecting means for detecting a lifting height of an elevating unit; and a load of a load placed on the elevating unit. A structure comprising: load detecting means for detecting; and lifting control means for automatically stopping the lifting operation of the lifting unit when the lifting unit is lifted to a lifting upper limit height determined based on the load. It is to be.

According to a second aspect of the present invention, in the cargo handling control device for a cargo handling vehicle according to the first aspect, the lift control means increases the lift of the lift unit before raising the lift unit to the lift upper limit height. The automatic reduction of speed.

According to a third aspect of the present invention, in the cargo handling control device for a cargo handling vehicle according to the first or second aspect, the lift control means patterns the lift upper limit height set based on the load. That is, the pattern data is stored.

According to the first aspect of the present invention, the lifting operation of the lifting unit is automatically stopped at the lifting upper limit height determined based on the load of the load placed on the lifting unit. Therefore, it is possible to prevent the stability of the cargo handling vehicle from decreasing.

According to the second aspect of the present invention, the lifting speed of the lifting unit is reduced just before the lifting unit reaches the maximum lifting height, so that the lifting unit is at the maximum lifting height. The shock at the time of stopping can be reduced.

According to the third aspect of the present invention, the upper limit of the lift in the lift control is easily determined based on the pattern data obtained by patterning the upper limit of the lift. can do.

[0010]

Next, an embodiment of the present invention will be described. FIG. 1 is a side view of the forklift. A fork (elevating unit described in the claims) 4 is attached to an elevating member 3 which is raised and lowered along the mast 2 by driving the lift cylinder 1. The operation box 5 provided in front of the driver's seat of the forklift has a fork 4
Is equipped with a cargo handling lever 6 operated when raising and lowering the vehicle. The mast 1 is tilted in the front-rear direction by a tilt cylinder 7 driven by the operation of a tilt lever (not shown).

FIG. 2 is a block diagram of a forklift cargo handling control. The control unit 10, which is the center of the cargo handling control, has a built-in microcomputer. On the input side of the control unit 10, a potentiometer 11 for outputting a signal corresponding to the operation angle of the cargo handling lever 6 and a tooth portion of a wheel 12 which rotates as the lifting member 3 moves up and down are detected. And fork 4
Rotary output pulse signal corresponding to the vertical position
An encoder 13 and a load sensor 15 for detecting the pressure of the pressure oil supplied to the lift cylinder 1 and outputting a signal corresponding to the load of the load 14 placed on the fork 4 are connected. .

On the output side of the control unit 10, a motor drive circuit 18 for supplying a drive current to a motor 17 for driving the hydraulic pump 16 and a pressure oil discharged from the hydraulic pump 16 are provided. An electromagnetic valve drive circuit 20 that supplies a drive current to a proportional electromagnetic valve 19 that controls the flow rate of pressure oil when supplying the pressure oil to the lift cylinder 1 is connected.

Next, the lift control processing in this forklift will be described with reference to the flowchart shown in FIG. After the microcomputer of the control unit 10 is initialized in step S1 of FIG. 3 and the processing flag N of this control processing is set to 0, the loading / unloading lever is controlled based on the signal from the potentiometer 11 in step S2. It is determined whether -6 has been operated. If it is determined in this step that the cargo handling lever 6 has been operated, the process proceeds to the next step S3, while if it is determined that the cargo handling lever 6 has not been operated, this control process ends. In step S3, a signal from the load sensor 15 is input to calculate the load of the load 14 placed on the fork 4.

The microcomputer of the control unit 10 includes:
A lift control pattern set based on the load of the load 14 placed on the fork 4 is incorporated. As shown in FIG. 4, the lift control pattern includes a fork lift upper limit height pattern A and a fork 4 lift just before the fork 4 reaches the lift upper limit height. And a deceleration start height pattern B indicating a position at which the high speed starts deceleration.

In step S4, the present height H of the fork 4 is calculated based on the pulse signal from the rotary encoder 13. In step S5, it is determined whether or not the processing up to step S4 is the first processing based on whether or not the processing flag N is 0. If it is determined that this process is the first process, the process proceeds to step S6, where the fork lift upper limit height (Hw) is determined based on the fork lift upper limit height pattern A, and In step S7, the deceleration start height (H) is determined based on the deceleration start height pattern B.
s) is determined. In step S8, the process count flag is set to 1, and the process proceeds to step S12.

In step S5, step S4
If it is determined that the processing up to is not the first processing, the process proceeds to step S9, and the current lift (H) is changed to the deceleration start height (H).
s) It is determined whether or not it is the above. If it is determined in step S9 that the current lift (H) is not equal to or greater than the deceleration start height (Hs), the process proceeds to step S8, where the number-of-processes flag is set to 1, and then the process proceeds to step S12. If it is determined that the lift (H) is equal to or higher than the deceleration start height (Hs), the opening of the proportional solenoid valve 19 is limited in step S10 to reduce the lift speed.

In step S11, it is determined whether or not the current lift (H) matches the fork lift upper limit height (Hw). If it is determined in step S11 that the current lift (H) does not match the fork lift upper limit height (Hw), the process proceeds to step S12, while the current lift (H) is forked. If it is determined that the upper limit height (Hw) has been matched, the proportional solenoid valve 19 is controlled to the fully closed state in step S13, and the drive current is supplied to the motor 17 in step S14. By stopping, the lift of the fork 4 is stopped as shown in step S15.

In step S12, it is determined whether or not the operation of the loading / unloading lever 6 has been stopped (set to a neutral state).
When the operation of the cargo handling lever 6 is stopped, the control process is terminated. On the other hand, when the operation of the cargo handling lever 6 is continued, the process returns to the step S4.

As described above, the control unit 10, which is the center of the cargo handling control, lifts the fork 4 when the fork 4 reaches the fork lift upper limit height (Hw). Automatically stop high motion. Before the fork 4 reaches the fork height upper limit height (Hw), the lifting speed of the fork 4 is reduced.

[0020]

According to the first aspect of the present invention, the lift of the lifting section can be automatically stopped at the lift upper limit height determined based on the load, so that the stability of the cargo handling vehicle is improved. It can be prevented from lowering.

According to the second aspect of the present invention, the lifting speed of the lifting unit is reduced before the lifting unit reaches the upper limit of the lifting height, so that the lifting unit stops at the lifting upper limit height. Shock can be reduced.

According to the third aspect of the present invention, the lift upper limit height in the lift control is easily determined based on the pattern data obtained by patterning the lift upper limit height.

[Brief description of the drawings]

FIG. 1 is a side view of a forklift.

FIG. 2 is a block diagram showing a configuration of a forklift cargo handling control device.

FIG. 3 is a flow chart showing a lift control process of a forklift;
It is a chart.

FIG. 4 is a lift control pattern diagram.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 lift cylinder 2 mast 3 lifting member 4 fork 6 cargo handling lever 10 control unit 11 potentiometer 13 rotary encoder 14 baggage 15 load sensor 16 hydraulic pump 17 motor 19 proportional solenoid valve

Claims (3)

[Claims] 1. A lifting height detecting means for detecting a lifting height of a lifting part, a load detecting means for detecting a load of a load placed on the lifting part, and the lifting part is determined based on the load. A loading control device for a loading and unloading vehicle, comprising: lifting control means for automatically stopping the lifting operation of the lifting unit when the lifting is performed to the lifting upper limit height. 2. The loading and unloading vehicle according to claim 1, wherein the lifting control means automatically reduces the lifting speed of the lifting unit before raising the lifting unit to the upper limit of the lifting height. Control device. 3. The lift control means according to claim 1, wherein said lift control means stores pattern data obtained by patterning a lift upper limit height set based on said load. A cargo handling control device for cargo handling vehicles.