JPH0592897A - Forklift control device - Google Patents

Abstract

PURPOSE:To provide a forklift control device abundant in operability and capable of preventing danger sufficiently and easily. CONSTITUTION:The output of an encoder 15 for detecting the lift position is compared to the data indicating the stop position read out of a memory 24 to stop the lift automatically. The upper limit of the travel speed of a forklift is controlled according to the lift position. There is further provided a card memory read-write device 16, and the data read out of this card memory is written into the memory 24 to perform control. The lift can be thereby stopped automatically so as to perform the same continuous operation correctly and easily, and the travel speed limit value can be adjusted according to the lift position, so that smooth speed control can be performed even at the high lift time. In addition, since vehicle performance can be stored in the card memory, the vehicle performance can be set easily even if an operator changes the vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift control device in which the upper limit of performance is determined on the basis of data stored in a memory means, and in particular, it has a function of displaying a failure location diagnosis result on a display. The present invention relates to a control device suitable for a battery forklift.

[0002]

2. Description of the Related Art Generally, loading and unloading work by a forklift is accompanied by some danger.
It increases with the performance of the forklift such as the traveling speed of the vehicle and the moving speed of the lift.

Therefore, conventionally, a method has been adopted in which the upper limit of the performance of the forklift such as the traveling speed of the vehicle and the moving speed of the lift is preset according to the place of use and the skill of the operator. Therefore, for example, in Japanese Examined Patent Publication No. 190206/1990, data for determining the upper limit of vehicle performance is stored in an erasable memory inside the control device, which limits the traveling speed of the vehicle and the moving speed of the lift. The technology disclosed in Japanese Patent Publication No. 2-7802 and Japanese Examined Patent Publication No. 2-78 are disclosed.
The publication No. 03 discloses a technique for displaying a failure location of a forklift and vehicle performance on a display.

[0004]

The above-mentioned prior art is concerned with the points of continuously stopping the lift at the same position, reducing the shock when the lift is stopped, and limiting the traveling speed according to the height of the lift. Is not considered,
There was a problem in terms of troublesome operability and sufficient prevention of danger.

Further, in the above-mentioned prior art, the above-mentioned data for determining the upper limit of the vehicle performance is effective only for each control device mounted on the vehicle, and when the operator changes the vehicle or when the same condition is set. Had to perform the same setting operation for multiple items each time.

An object of the present invention is to provide a forklift control device which is excellent in operability and which can easily obtain sufficient danger prevention.

[0007]

The object is to detect the position of the lift and generate a position signal, and a stop position data input means for storing data designating the stop position of the lift in the memory means. Stop signal generating means for generating a lift stop signal by comparing the position signal output from the detecting means with data representing the stop position read from the memory means, and stopping the lift drive by the lift stop signal. It is achieved by

Further, the above object is to provide means for detecting a deviation value between the position signal output from the detecting means and the data representing the stop position read from the memory means, and to raise the lift according to the deviation value. It is achieved by controlling the speed.

Further, the above object is achieved by providing a means for calculating the traveling speed of the forklift according to the position signal, and controlling the upper limit of the traveling speed according to the position of the lift.

The above object is achieved by providing means for reading data from the card memory and writing the data read from the card memory in the memory means for control.

[0011]

[Operation] As for the lift speed of the lift, the deviation between the position of the lift stored in the memory and the position of the moving lift is reduced,
The operation is performed such that the speed becomes slower as the lift rising speed is faster than the reference speed. As a result, the lift automatically stops at the position designated by the operator, facilitating continuous operation.

Further, since the traveling speed is automatically limited depending on the position of the lift, there is no fear of falling, and smooth and safe traveling is possible. Further, the vehicle performance data set for each operator is the operator. Since the data is stored in the card memory that is managed for each vehicle, even if the operator changes the vehicle, the prescribed data can be set by simply reading the data stored in the card memory into the vehicle, and the vehicle performance data can be re-read. The setting is easy, and the trouble of setting can be greatly saved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A forklift control device according to the present invention will be described below in detail with reference to the illustrated embodiments. Figure 1
Is an embodiment in which the present invention is applied to a battery forklift. In the forklift controller according to this embodiment, a battery 1 and a microcomputer (microcomputer) are provided.
2, chopper control circuit 3, lift automatic stop signal output circuit 4, data transmission circuit 5, data reception circuit 6, mode changeover switch 7, ENTER switch 8, item selection switches 9, 10, 11, 12, 13, 14, encoder 1
5, card memory read / write device 16, for lifts (for cargo handling)
Chopper 17, traveling chopper 18, lift switch 1
9, chopper drive circuit 20A, 20B, key switch 2
1, a display device 22, a display panel 23, a memory 24, and a traveling speed limit signal output circuit 25, and the traveling electric motor M
1 and the lift electric motor M2 are chopper controlled. The lift is driven by a hydraulic system. Therefore, the lift electric motor M2 drives the hydraulic pump only when the lift is raised.

The encoder 15 is arranged in a lift (not shown) and functions to generate a pulse in accordance with the movement of the lift. The card memory read / write device 16 functions to read data from and write data to a magnetic card or an IC card.

FIG. 2 shows the details of the display panel 23. The display panel 23 is arranged in the driver's seat of the forklift, and the mode changeover switch 7 and the ENTER switch are provided.
Switch 8 and item selection switches 9, 10, 11, 1
2, 13, 14 and a display 22 are provided on them.

The memory 24 is a memory device capable of writing and reading data and retaining the stored contents even when the key switch 21 is turned off. The data stored in the memory 24 indicates the traveling speed of the vehicle and the lift. It acts to give an upper limit to the performance of the forklift such as moving speed.

Next, the operation of this embodiment will be described. First, the operation of the forklift is the same as that of the conventional battery forklift.
When is turned on, power is supplied to the microcomputer 2 and the chopper control circuit 3, and the control operation is started. Therefore, the chopper control circuit 3 supplies a chopper signal to the lift chopper 17 or the traveling chopper 18 via the chopper drive circuit 20A or the chopper drive circuit B by an input from an operation lever or the like (not shown), The traveling speed of the forklift and the lifting speed of the lift are controlled by controlling the flow rate of the traveling electric motor M1 and the lifting electric motor M2.

At this time, the upper limit of the performance of the forklift such as the traveling speed of the vehicle and the moving speed of the lift is given by the data stored in the memory 24, and the safety is sufficiently maintained even in the case of an erroneous operation by the operator. So that Further, the chopper control circuit 3 is provided with a predetermined self-diagnosis function, and while the forlift is operating, various function checks are sequentially performed and the diagnosis result is written in the memory 24. There is.

Next, when the key switch 21 is turned on as described above, the microcomputer 2 causes the display 22 of the display panel 23 to display the operation contents in each mode and the contents of transmission and reception data. To

Then, the operator operates the mode selector switch 7 on the display panel 23 to switch the mode. When this mode changeover switch 7 is pressed, as shown in FIG. 3, the display 22 displays “analyzer mode?”, “Performance variable mode?”, And “automatic lift mode?”. Are item selection switches 9, 10,
Each mode is selected by 11, 12, 13, and 14.

Now, assuming that the analyzer mode is selected, the processing shown in FIG. 4 is executed by the microcomputer 2 at this time. First, from the microcomputer 2, for example, 8-bit serial data 01010101 (hexadecimal number 55H) data is transmitted to the chopper control circuit 3 via the data transmission circuit 5 (step 40). Next, at this time, if the memory 24 of the chopper control circuit 3 has data to be transmitted according to the self-diagnosis result, the chopper control circuit 3 outputs 0 as 8-bit serial data, for example.
The data of 00000001 (01H in hexadecimal notation) is
The data is received by the microcomputer 2 via the data receiving circuit 6 (step 41).

The received data is displayed on the display 22 by the microcomputer 2 (step 42). Then, this display is continued until the display timer of the microcomputer 3 reaches, for example, 10 seconds (steps 43 and 44). Thus, when the display timer reaches 10 seconds, the analyzer mode is terminated,
It returns to the mode switching waiting state (step 4).
5). Therefore, the operator can know the self-diagnosis results up to that time by selecting this analyzer mode.

Next, assuming that the variable performance mode is selected in the processing of FIG. 3, the processing shown in FIG. 5 is executed by the microcomputer 2 this time. In the variable performance mode, a process for changing the vehicle performance data and a process for setting the vehicle performance data from the card memory are performed.
If the process of changing the vehicle performance data is selected in 1, the microcomputer 2 determines that “lift 1?”, “Lift 2?”,
"Tilt?", "Reach?", "Attachment?",
Display 22 for selecting performance data such as "Plugging?"
To display. Therefore, the operator selects the required performance data with the item selection switches 9, 10, 11, 12, 13, 14 and the ENTER switch 8 (steps 502, 503).

When the performance data is selected, the microcomputer 2
Causes the display 22 to display the performance data name and the performance data value, so that the operator can select the item selection switches 9, 1
By operating 0, 11, 12, 13, and 14, the performance data value can be visually changed (step 504). Next, the operator turns on the ENTER switch 8 after changing the performance data value (step 50
5), the process proceeds to the next process, and the card memory read / write device 16
If the IC memory card is set in (step 506), the performance data is written in the IC memory card (step 507), and then the performance data is stored in the memory 24 of the chopper control circuit 3 via the data transmission circuit 5. Is transmitted (step 508).

When the data value change is continued, the performance data selection display is returned, but when the end of the data value change is input, the performance data change mode is ended,
The process returns to the mode switching waiting state (step 509).

On the other hand, when the operator selects a process that does not change the vehicle performance data in step 501, for example, when the operator changes the vehicle, the IC memory card storing the performance data is stored in the card memory read / write device. Confirm that it is set to 16 (step 510)
Then, the performance data is read from the IC memory card and transmitted to the memory 24 of the chopper control circuit 3 via the data transmission circuit 5 (step 511).

When the data transmission is completed, the performance data change mode is terminated and the mode switching waiting state is returned to.

Therefore, according to this embodiment, the data input operation for determining the upper limit of the vehicle performance can be easily performed without erroneous operation simply by looking at the instruction displayed on the display 22 of the display panel 23. In addition, since the vehicle performance data set for each operator is stored in the IC card memory owned by each operator, even if the operator changes the vehicle, the IC card memory is stored in the vehicle. Predetermined data can be set only by reading the data stored in, the vehicle performance data can be easily reset, and the setting labor can be greatly saved.

Although the IC memory card is used as the card memory in the above embodiment, a magnetic memory card may be used.

Next, in the process of FIG. 3, when the automatic lifting mode is selected, the process shown in FIG. 6 is executed by the microcomputer 2. Now, if the operator turns on the lift switch 19 in a state where the automatic lifting mode is selected, the chopper control circuit 3 causes the chopper 17 for lift (cargo handling) to move to the chopper 17 for lift (cargo handling). The drive signal is supplied, the lift motor M2 operates, and the lift rises. Then, the upward movement of the lift causes the encoder 15 to output a pulse signal.

Therefore, the two-phase pulse signal from the encoder 15 is fetched into the microcomputer 2 (step 601),
The counter of the microcomputer 2 counts up when the lift is raised and counts down when the lift is lowered (step 602) to detect and store the position of the lift (step 603). Next, the amount of change of this counter per unit time is calculated to obtain the lift rising speed (step 60).
4). The content of this calculation is determined by the configuration of the lift drive system of the forklift. For example, in a certain forklift, the sampling time of the counter is set to 20 ms, and a value obtained by multiplying the change amount by 15 is taken as the lift rising speed.

In this way, the operator operates the lift switch 19 to continuously raise or lower the lift to a position at which the lift should be automatically stopped, and then at the position at which the automatic stop should be performed, the item selection switch is set. When the memory input mode and memory address are selected by 9, 10, 11, 12, 13, and 14 (step 60
5, 606), the value of the counter at this automatic stop position is stored in a predetermined address of the memory 24 (step 60).
7).

On the other hand, the item selection switches 9, 10, 11,
If the automatic stop mode and the memory address input are selected by 12, 13, and 14 (steps 605, 608,
609), the data of the selected memory address is stored in the automatic stop height memory (predetermined area of the memory 24) (step 610), and then the automatic lift stop control process is executed.

First, the value of the counter indicating the lift height,
When the difference between the data values of the automatic stop height is an arbitrarily set value, for example, 20 pulses or more, it is determined that the lift height is larger than the deceleration height of the cargo handling chopper (step 611), and the cargo handling chopper command (for lift) The command to the chopper 17) is kept at 100% (step 612).

Further, the height of the lift is equal to or higher than the cargo handling chopper stop height (automatic stop height) (determination in step 613 is N.
o), the lift speed is compared with a value obtained by multiplying the cargo handling chopper command (signal for automatically stopping the lift) from the lift automatic stop signal output circuit 4 by several times, and when the lift speed is high (step 615). If the determination is Yes, the control signal for automatically stopping the lift, that is, the cargo handling chopper command is reduced by 5% (step 616).

On the other hand, when the difference between the data is 20 pulses or less (Yes in step 613), the cargo handling chopper command is set to 0% (step 614). As a result, from the chopper control circuit 3, steps 612, 614 and 61 are performed independently of the lift operation command from the operator.
A control signal corresponding to the cargo handling chopper command by any of the processes of 6 is supplied to the lift chopper 17 (step 61
7) The lift is automatically decelerated as it approaches the automatic stop position, and then automatically stopped at the automatic stop position according to the character.

Subsequently, the height of the lift is determined by the predictive memory 2
Check whether it exceeds the standard height set in 4.
(Step 618) If the result is Yes, the traveling chopper command (command to the traveling chopper 18) is also set so that this also becomes the predetermined traveling speed set in the prediction memory 24.
Is reduced to a predetermined value (step 619).

Therefore, according to this embodiment, when the lifted position is higher than or equal to the predetermined height, the maximum value of the traveling speed is automatically limited to the predetermined speed. It is possible to prevent a dangerous situation such as a fall accident due to traveling at a high speed at a position.

Next, the control signal for automatically stopping the lift during the automatic stop will be described with reference to FIG.
In FIG. 7, the vertical axis represents the count value C of the counter representing the lift height, and the horizontal axis represents the deviation D between the value of the automatic height memory and the counter value C. As is clear from the above, according to the above-described embodiment, the deviation D decreases due to the lift rise, and the lift position reaches the arbitrarily set point b. At this time, if the lift rise speed exceeds the reference speed, When the speed is reduced and the deviation D reaches the arbitrarily set point a, the control signal for automatically stopping the lift is set to 0% to stop the operation of the cargo handling chopper by the chopper control circuit 3 and raise the lift. It can be seen that the speed is set to zero and the lift smoothly stops at the automatic stop position preset by the operator.

Next, the control of the traveling speed depending on the position of the lift will be described with reference to FIG. This Figure 8
The vertical axis is the traveling chopper conduction ratio A, and the horizontal axis is the lift position B. According to this figure, while the traveling chopper 18 is operating, the lift switch 19 is turned on to lift the lift. , When the position of the lift reaches a predetermined position d that is set in advance, and reaches a position c that is a predetermined distance away,
It can be easily understood that the limit value of the traveling chopper conduction ratio A is reduced and when the position c is reached, the traveling chopper conduction ratio is reduced to an arbitrary value and the traveling speed is limited to a predetermined value.

Therefore, according to this embodiment, when the lift is set to a high position, the upper limit of the traveling speed is automatically suppressed to a predetermined value, and the traveling speed can always be controlled smoothly and safely. .. The control characteristic of the traveling chopper conduction ratio at this time may be set as shown by e or f in FIG.

[0042]

According to the present invention, since the vehicle performance for each operator can be stored in an IC memory card or the like, there is an effect that the vehicle performance can be easily set even if the operator changes the vehicle. Further, since the lift can be automatically stopped, there is an effect that the same continuous operation can be accurately and easily performed. Further, since the traveling speed limit value can be changed according to the position of the lift, there is an effect that smooth speed control can be performed even at high lift and sufficient safety can be maintained.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of a forklift control device according to the present invention.

FIG. 2 is a front view of an operation panel according to an embodiment of the present invention.

FIG. 3 is a flowchart of a mode switching process according to an embodiment of the present invention.

FIG. 4 is a flowchart of analyzer mode processing according to an embodiment of the present invention.

FIG. 5 is a flowchart of performance variable mode processing according to an embodiment of the present invention.

FIG. 6 is a flow chart of automatic elevation mode processing in one embodiment of the present invention.

FIG. 7 is a characteristic diagram of a lift automatic stop operation according to an embodiment of the present invention.

FIG. 8 is a characteristic diagram of a traveling speed limiting operation according to the position of the lift in the embodiment of the present invention.

[Explanation of symbols]

 1 Battery 2 Microcomputer (Microcomputer) 3 Chopper Control Circuit 4 Lift Automatic Stop Signal Output Circuit 5 Data Transmission Circuit 6 Data Reception Circuit 7 Mode Change Switch 8 ENTER Switch 9 10, 11, 12, 13, 14 Item Selection Switch 15 Encoder 16 Card memory read / write device 22 Display 23 Display panel 24 Memory Travel speed limit signal output circuit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Nobuyoshi Takahashi 2477, Kashima Yatsu, Takaba, Katsuta City, Ibaraki Prefecture 3 Hitachi Automotive Engineering Co., Ltd. (72) Inventor Minoru Shincho, Katsuta City, Ibaraki Prefecture Takaba 2520, Hitachi Ltd. Automotive Equipment Division

Claims (4)

[Claims] 1. A forklift control device comprising a memory means, wherein the upper limit of the performance of the forklift is determined based on the data stored in the memory means, the detection of detecting the position of the lift and generating a position signal. Means, stop position data input means for storing data designating a stop position of the lift in the memory means, position signal output from the detecting means and data representing the stop position read from the memory means. Stop signal generating means for generating a lift stop signal is provided, and the lift drive is stopped by the lift stop signal. 2. The invention according to claim 1, further comprising means for detecting a deviation value between a position signal output from the detecting means and data representing a stop position read from the memory means, and the deviation value is detected according to the deviation value. A forklift control device, characterized in that it is configured to control the lifting speed of the lift. 3. The invention according to claim 1, further comprising means for calculating the traveling speed of the forklift according to the position signal, and the upper limit of the traveling speed is controlled according to the position of the lift. Forklift control device. 4. The invention according to claim 1, wherein means for reading data from a card memory is provided, and the data read from the card memory is written in the memory means for control. Forklift control device.