JPH10194696A - Battery type forklift - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow operation of a battery type forklift with the same operation feeling for an internal combustion engine type forklift and to prevent wrong operation of a battery type forking by a driver who usually uses an internal combustion engine type one. SOLUTION: This battery type forklift is provided with a traveling motor MS, a cargo handling motor MM, and a controller 4 controlling these motors MS, MM. The controller 4 controls rotational force of the cargo handling motor MM on the basis of a signal from a traveling speed command unit in a travel control unit 5 provided with a traveling direction unit, which generates a signal instructing the traveling motor MS on the direction of its rotation, and the traveling speed command unit, which generates a signal controlling rotational force of the motor MS and possesses a pedal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a battery-operated forklift, in which the handling operation of the battery-powered forklift is substantially the same as that of the internal-combustion-engine-powered forklift. The present invention relates to a battery-powered forklift capable of preventing erroneous operation and improving work safety.

[0002]

2. Description of the Related Art As shown in FIG. 6, a conventional battery-powered forklift has two operating tools a and b each having a control system in which a traveling motor ms and a cargo handling motor mm are independent from each other.
Operated by Therefore, at the time of the cargo handling operation, the lifting, lowering and stopping operations of the cargo handling device and the speed adjustment of the cargo handling operation can be performed only by operating the cargo handling operation tool without operating the traveling operation tool a.

[0003] On the other hand, in an internal combustion engine type forklift, traveling and loading are powered by the same prime mover.
Therefore, when performing a cargo handling operation, in addition to a cargo handling operation tool (for example, a lever operation), an operation of adjusting the output of the prime mover by operating a traveling accelerator pedal to adjust the speed of the cargo handling operation is performed. Required separately. As described above, the loading operation is basically different between the battery type forklift and the internal combustion engine type forklift.

[0004]

As described above, since the two operations are different from each other, when an operator skilled in the operation of an internal combustion engine type forklift operates a battery type forklift, the accelerator pedal for traveling during loading and unloading work is used. There is a risk of accidental operations such as sudden operation of the battery-powered forklift due to an erroneous operation such as stepping on the vehicle at the same time, and a sudden cargo handling operation resulting in collapse of the load and collision.

The inventor of the present invention has conducted various studies to solve the above problems. As a result, the present inventors have found that the rotational force of the cargo handling motor can be controlled by using a control signal from a pedal for controlling the rotational force of the traveling motor. The present invention has been completed by focusing on the fact that the battery type forklift can be operated by substantially the same operation as that of an internal combustion engine type forklift.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery-powered forklift capable of preventing accidents due to erroneous operation and improving work safety when a driver who operates an internal-combustion engine-powered forklift always operates a battery-powered forklift. I have.

[0007]

Means for Solving the Problems In the present invention, claim 1 is provided.
The invention described is a battery-operated forklift including a traveling motor that drives traveling wheels, a cargo-handling motor that drives a cargo-handling device, and a control device that controls the traveling motor and the cargo-handling motor. A control unit configured to generate a signal for instructing the traveling motor to indicate a rotation direction and a neutral state; and a traveling speed command including a pedal for generating a signal for controlling the rotational force of the traveling motor. The driving force of the cargo handling motor is controlled by a signal from the traveling speed command section of the traveling control section having the section.

[0008] The battery type forklift of the present invention having the above-described configuration enables the rotational force of the cargo handling motor to be operated by a signal from a traveling speed command unit using, for example, an accelerator pedal for traveling. Thereby, the operation procedure similar to operating the internal combustion type forklift, the loading operation of the battery type forklift can be performed with the feeling, even if the driver operates mainly with the internal combustion type forklift,
It is possible to operate the battery-powered forklift efficiently without erroneous operation.

According to a second aspect of the present invention, the control device includes: a cargo handling speed command unit for generating a signal for controlling a rotational force of the cargo handling motor; a signal from the cargo handling speed command unit;
A control switching device that switches a signal from the traveling speed command unit and controls the rotational force of the cargo handling motor using one of the signals.

According to the second aspect of the invention, as in the case of a normal battery-powered forklift, the operating force of the loading operation machine can be controlled by a signal from a loading speed command unit such as a loading lever. The battery-operated forklift can be operated by appropriately selecting a maneuvering type that the user is good at. As described above, in the present invention, the usage of the battery-powered forklift is enhanced by diversifying the operation method.

According to the third aspect of the present invention, the control switching device includes signal level adjusting means,
This is preferable in that the signal sent from the cargo handling speed command unit and originally used for traveling control can be adjusted in level so as to match the signal from the original cargo handling speed command unit.

According to the fourth aspect of the present invention, since the rotational force of the traveling motor and the cargo handling motor is controlled by chopper control, control efficiency can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings, taking a counterbalanced type equipped with a fork, which is capable of lifting and lowering and tilting a battery-operated forklift as its cargo handling device.

1 to 5, a battery-powered forklift 1 includes a traveling motor MS for driving traveling wheels 2 and a cargo handling device 3. The cargo handling device 3 includes a tiltable mast 2
2 and a fork 21 which moves up and down along the mast 22 in this example. The lifting and lowering of the fork 21 and the tilting of the mast 22 are driven by a lifting cylinder L and a tilting cylinder T, respectively.

The battery-powered forklift 1 includes a control device 4 for controlling the traveling motor MS and the loading motor MM for operating the lifting / lowering cylinder L and the tilting cylinder T.

As shown in FIG. 5, the cargo handling motor MM is connected to a hydraulic pump P. Then, in this example, the pressure oil discharged from the hydraulic pump P is operated by the operation levers 32A and 32A.
The lifting cylinder L or the tilting cylinder T is operated via the switching valves 40 and 41 switched by B. In the present embodiment, the traveling motor MS and the cargo handling motor MM each employ a DC series-wound motor that can be easily driven at a variable speed using a battery as a power source.

As shown in FIG. 3, the control device 4 controls a traveling control unit 5 for controlling a traveling motor MS and the loading motor MM for operating a lifting cylinder L or a tilting cylinder T. Equipped with a cargo handling speed command unit 12 for the purpose.

In the present embodiment, the traveling control section 5 is composed of a traveling direction command section 9 and a traveling speed command section 10.

The traveling direction instructing section 9 is provided with a directional switch 24 (also shown in FIGS. 2 and 4) for generating a signal for instructing the traveling motor MS in the direction of rotation and in a neutral state, for example, by stepping on the foot. By tilting with
And a start command section 7a that is operated by a pedal 7 that can be turned on to start the traveling motor MS. Note that a limit switch, for example, is used as the start command unit 7a.

The traveling speed command section 10 generates a signal for controlling the rotational force of the traveling motor MS in accordance with the amount of depression of the pedal 7. This traveling speed command unit 10
For example, a potentiometer or the like can be used.

As shown in FIG. 2, equipment necessary for traveling, such as a steering wheel 25 and a brake pedal 26 for braking the traveling wheels 2, are appropriately arranged in the driver's seat of the battery type forklift 1.

In the present embodiment, the directional switch 24 is provided on a post of the handle 25. By operating the directional switch 24, the polarity of the field 29 of the traveling motor MS is changed to normal, reverse or reverse as shown in FIG. It can be switched to cutoff, and the rotation direction and stop of the traveling motor MS are set. FIG. 4 shows a stopped state.

The directional switch 24
Is provided with the start command section 7a in series. Therefore,
Through two operations of an instruction of the rotation direction by the directional switch 24 and an ON operation of the start command unit 7a,
An example in which the polarity can be switched is illustrated.

The traveling motor MS is controlled by a chopper 30 in this embodiment. And this chopper 30
Is a traveling speed command unit 10 corresponding to the depression amount of the pedal 7
ON, OF by inputting speed command signal from
F.

In the present embodiment, the loading / unloading speed command section 12 includes a lift lever 32A and a tilt lever 32B which can be tilted back and forth by hand, and potentiometers PA and PB (FIG. 1) which can output signals corresponding to the operation amounts of the respective levers. 5).

As shown in FIG. 5, the lift lever 32A switches the switching valve 40 for lifting and lowering the fork 21, and the tilt lever 32B switches the switching valve 41 for tilting the mast 22. For example, when the lift lever 32A is tilted backward,
The switching valve 40 can be switched to the port U, and the extension of the elevating cylinder L can be instructed. Conversely, when the lift lever 32A is tilted forward, the switching valve 40 is switched to the port D, and the reduction of the lifting cylinder L can be instructed. In addition, when in the neutral state, an instruction to stop the lifting cylinder L is issued.

In general, signals from potentiometers PA and PB provided on the lift levers 32A and tilt levers 32B control the rotational force of the loading motor MM connected to the hydraulic pump in this example. Used for The control of the rotational force of the loading motor MM is controlled by the chopper 42 which can be conductive or non-conductive by this signal. Therefore, the cargo handling speed command unit 12 can instruct the direction of expansion and contraction of each of the cylinders T and L, the stop, the operating force, and the like.

Next, in the present embodiment, the control device 4
Is a control switching device 14 that switches between a signal from the cargo handling speed command unit 12 and a signal from the traveling speed command unit, and controls the rotational force of the hydraulic motor MM using one of the signals.
Are exemplified.

The control switching device 14 is provided with, for example, a switching lever 33 shown in FIGS. 1 and 2, and by operating the switching lever 33, a signal from the cargo handling speed command unit 12 is cut off, and a signal from the traveling speed command unit 10 is cut off. It has a changeover switch 34 having a contact 38 and a contact 39 which can simultaneously conduct signals.

The changeover switch 34 selects a signal from the cargo handling speed command section 12 and a signal from the traveling speed command section 10 and controls the drive of the cargo handling motor MM based on one of the signals. Can be.

In the present embodiment, the control switching device 14
A signal level adjusting means 35 for adjusting the signal level (gain) of the signal from the cargo handling speed command unit 12 and the signal from the traveling speed command unit 10 is illustrated. As the signal level adjusting means 35, for example, an operational amplifier or the like can be used, and the signal from the traveling speed command unit 10 is adjusted so as to have a level suitable for controlling the cargo handling motor MM. This prevents errors due to switching.

A lamp 36 for indicating the switching state of the control switching device 14 is provided at, for example, the driver's seat of the battery type forklift 1. In this example, the contact 37
Blinks in order to notify the closing operation of the cargo handling motor MM in this example, that is, the state in which the drive of the cargo handling motor MM is controlled based on the signal from the traveling speed command unit 10. Thereby, erroneous operation can be prevented.

However, when the battery-powered forklift 1 is operated by a standard cargo handling operation, the control switching device 1 is operated by operating the switching lever 33 as shown in FIG.
4 is switched so that the signal circuit is conducted between the cargo handling speed command unit 12 and the cargo handling motor MM.

Thereafter, for example, when the lift lever 32A is tilted backward, the cargo handling speed command section 12 generates a command to raise the fork 21. The rising command generates a signal corresponding to the tilt angle of the lift lever 32A, and the signal is input to the chopper 42 via the control switching device 14 to control the rotational force of the cargo handling motor MM.

Further, the loading motor MM drives the hydraulic pump P to send pressure oil from the port U of the switching valve 40 to the bottom of the lifting cylinder L to raise the fork 21.

The traveling speed command from the traveling control unit 5 is output without relating to the control of the cargo handling control unit 6,
Therefore, the forklift 1 can freely move forward, backward, and stop according to a command.

Next, a description will be given of a case where control is performed by substantially the same operation as that of an internal combustion engine type forklift. In this case, first, the switching lever 33 is operated, the contact 39 is opened, and the contact 38 is closed, whereby the signal from the loading speed command unit 12 is cut off, and the traveling speed command unit 10 and the loading motor MM are turned off. Is made conductive. Further, the lamp 36 can blink to notify the driver that the switching is being performed.

Next, when the driver depresses the pedal 7, a signal corresponding to the depression amount is output from the traveling speed command unit 10. Then, this signal passes through the signal level adjusting means 35 and is adjusted in level.
It is output to the chopper 42 through the contact 38 and controls the rotational force of the cargo handling motor MM. This also drives the pump P to send out the pressure oil.

At this time, by inclining the lift lever 32A backward, the switching valve 40 is mechanically switched to the port U, and the pressure oil from the pump P can be sent to the bottom of the lifting / lowering cylinder L. Therefore, by adjusting the amount of depression of the pedal 7, the rotational force of the cargo handling motor MM is changed, and thus the ascending speed of the fork 21 can be adjusted. In this case, the signal output from the potentiometer PA provided on the lift lever 32A does not affect the rising speed of the fork 21.

The above-mentioned cargo handling operation is substantially the same as the cargo handling operation of the internal combustion engine type forklift. Therefore, by providing the control device having the above-described configuration, even if the operator always operates the internal combustion engine type forklift, the operator can mistakenly operate it. It is possible to carry out safe and quick cargo handling work without performing.

It should be noted that the signal from the traveling speed command unit 10 is not affected by the signal from the traveling speed command unit 10 even while the loading / unloading motor MM is performing the rotational force control.
It is also transmitted to S.

Therefore, it is possible to carry out both traveling and cargo handling in parallel, but usually, the directional switch 24 is used.
In many cases, it is preferable to perform the cargo handling operation with the neutral position being neutral. Therefore, it is possible to provide a safety device that enables such control only when the directional switch 24 is in the neutral position.

Although not shown, such a safety device is realized by, for example, inputting a logical product output of a traveling speed command signal and a neutral position signal of the directional switch 24 to the control switching device 14. sell.

The switching lever 33 of the control switching device 14
When the vehicle is switched to connect the cargo handling motor MM and the traveling speed command unit 10, the vehicle is stopped regardless of the position of the directional switch 24 by stopping the traveling circuit or the like. it can.

Further, in the present embodiment, the control device 5 includes the control switching device 14, but the control switching device 14 is omitted, and the control of the loading motor MM is always performed based on the signal from the traveling speed command. It can be modified to control the rotational force.

Further, in this embodiment, the lift lever 3
2A and the tilt lever 32B are both mechanically switched
Although an example of switching between 0 and 41 is illustrated, for example, each lever only displaces the potentiometers PA and PB, and an electromagnetic proportional control valve or the like that changes the opening / closing degree of the valve based on the displacement of the potentiometers PA and PB. It can be adopted for the forklift used.

In this case, the signal from the traveling speed command unit is used as a signal for controlling the flow rate of the electromagnetic proportional control valve in addition to controlling the rotational force of the hydraulic motor MM, thereby providing the same as in the present embodiment. The operating force of each cylinder can also be controlled.

As described in detail above, the control device according to the present invention is applied to a loading motor for operating a rotating fork having a rotating function or a clamp fork having a clamping function in a loading device. The present invention can be modified into various embodiments.

[0049]

According to the battery type forklift of the present invention,
By providing the above configuration, as a result of being able to operate the rotational force of the cargo handling motor by a signal from a traveling speed command unit using, for example, an accelerator pedal for traveling, an operating procedure close to operating an internal combustion type forklift, A battery-operated forklift can be loaded and operated with a sense and even a driver who operates mainly with an internal-combustion forklift can efficiently operate the battery-powered forklift without erroneous operation.

According to the second aspect of the present invention, similarly to a normal battery type forklift, the rotational force of the loading motor can be controlled by a signal from a loading speed commanding unit such as a loading lever. The user can operate the battery-powered forklift by appropriately selecting a maneuvering type that the user is good at, and by diversifying the operation method of the battery-powered forklift, the utilization can be greatly increased.

According to the third aspect of the present invention, the control switching device includes signal level adjusting means,
The signal sent from the cargo handling speed command unit and used for the original travel control can be adjusted to match the signal from the original cargo handling speed command unit, thereby preventing errors and facilitating control.

According to the fourth aspect of the present invention, since the rotational force of the traveling motor and the cargo handling motor is controlled by chopper control, control efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of the present invention.

FIG. 2 is a plan view illustrating the control device.

FIG. 3 is a system block diagram thereof.

FIG. 4 is a wiring diagram showing an example of direction designation and rotational force control of a traveling motor.

FIG. 5 is a hydraulic circuit diagram of the battery-powered forklift.

FIG. 6 is a system block diagram showing conventional control.

[Explanation of symbols]

 Reference Signs List 2 traveling wheel 3 loading / unloading device 4 control device 5 traveling control unit 6 loading / unloading control unit 7 pedal 9 traveling direction command unit 10 traveling speed command unit 11 loading direction control unit 12 loading / unloading speed command unit 14 control switching unit 35 signal level adjusting means MS traveling Motor MM Cargo handling motor

Claims (4)

[Claims] 1. A battery type forklift comprising: a traveling motor for driving traveling wheels; a cargo handling motor for driving a cargo handling device; and a control device for controlling the traveling motor and the cargo handling motor. A control unit configured to generate a signal for instructing the traveling motor to indicate a rotation direction and a neutral state; and a traveling speed command including a pedal for generating a signal for controlling the rotational force of the traveling motor. A battery-powered forklift, wherein the rotational force of the cargo handling motor is controlled by a signal from the traveling speed command unit of a traveling control unit having a driving unit. 2. The control device according to claim 1, further comprising: a loading speed command unit for generating a signal for controlling a rotational force of the loading motor; a signal from the loading speed command unit; and a signal from the traveling speed command unit. The battery-powered forklift according to claim 1, further comprising: a control switching device that controls a rotational force of the cargo-handling motor based on one of the signals. 3. The control switching device according to claim 2, further comprising signal level adjusting means for adjusting a signal level of a signal from the cargo handling speed command section and a signal level from the traveling speed command section. The battery-powered forklift as described. 4. The battery-powered forklift according to claim 1, wherein a rotational force of the traveling motor and the cargo handling motor is controlled by chopper control.