JPS59198802A - Vehicle for industry - Google Patents

Abstract

PURPOSE:To enable a vehicle to operate for a long period by charging a battery with a DC output outputted from a rectifier when a power consumption is small, enabling to supply an electric power from the battery when the power consumption exceeds the output of an AC generator, reducing an engine for saving fuel, and reducing noise and exhaust gas. CONSTITUTION:An AC generator 12 supplies its output through a switch 23 also to a hydraulic pump driving DC motor 21 to operate a working hydraulic pump 22 to operate a working machine, and through a switch 24 to a battery 25 to charge it. This battery 25 has a capacity capable of charging and supplying a current in response to the variation in a load applied to the generator 12, and can supply its DC output to an SCR chopper controller 15, and the DC motor 21. In this manner, it can be operated in the optimum fuel consumption state of the engine, thereby reducing the size of the engine and decreasing the fuel consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial vehicle, and more particularly to an industrial vehicle that can be applied to a forklift, a wheel loader, and the like.

The following vehicles are mainly known as conventional industrial vehicles.

(1) A type that uses an engine as a drive source and transmits mechanical rotational power to the running tires, which is also used directly to drive a hydraulic pump for working equipment (engine type).

(2) The engine drives a generator, and the electric power directly drives the electric motors (for traveling and work equipment), and when the engine stops, both the electric motors for travel and work equipment stop (engine electric type).

(3) A device that uses a battery as an energy source to drive motors for traveling and work equipment (battery-driven type).

Among the above, (1) and (2) are difficult to use for indoor work because they involve noise and exhaust gas pollution5, and maintenance costs (fuel costs).
is high. (3) has a limited battery energy storage and cannot be used continuously. It also has drawbacks such as lack of power and poor efficiency.

The present invention was proposed in view of the above circumstances, and is an industrial-use engine that reduces the size of the engine, saves fuel consumption, reduces noise and exhaust gas7, and enables longer operating times than battery-powered engines. Vehicles are provided.

The industrial vehicle according to the present invention includes an engine that operates at a rotational speed near the optimum fuel efficiency, an alternator driven by the engine, a rectifier that converts alternating current output from the alternator into direct current, and the alternating current generator. A control device for controlling the output of the machine is provided, and when the DC output output from the rectifier is supplied to the traveling electric motor and the working machine electric motor, the power consumption of the traveling electric motor and the working machine electric motor is low. when the battery is charged, and when the power consumption exceeds the output of the alternator, power can also be supplied from the battery to the traveling electric motor and the working machine electric motor, In addition to setting the engine governor so that the engine can always be operated at near optimal fuel efficiency, the output of the alternator is preferentially used while each of the above motors is in operation to reduce battery consumption, and the surplus of the alternator is The battery is always charged with the output, and when the output of the alternator is insufficient, the battery is also controlled to supply power to the load side,
Furthermore, when working indoors, the engine is brought out to supply power from the battery to the load side, thereby preventing noise and exhaust gas.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram illustrating the configuration of an industrial vehicle according to an embodiment of the present invention.

In Fig. 1, 11 is an engine, 12 is an alternator, 1
3 is a rectifier, 14, 23.24 is each switch, 15
is the thyristor chopper control device, I6 is the accelerator, 17
is a running DC motor, 18 is a reduction gear, z9 is a differential gear, 20 is a running tire, 21 is a DC motor for driving a hydraulic pump, 22 is a working hydraulic pump, 2'5 is a battery, and 26 is a control device. be.

Engine II is equipped with a governor (not shown) that adjusts the rotational speed to a set value, and is always operated at a rotational speed near the optimum fuel efficiency.
, which drives the alternating current generator I2. This alternator 12 is connected to the engine 11 via a control device 26 and is controlled to bring the generator load into the optimum fuel efficiency state of the engine 51. Generates alternating current power. This AC power is then converted into DC power by the rectifier 13 and supplied to the thyristor chopper control device I5 via the switch I4. This thyristor chopper control device 15 controls the DC power in conjunction with the operation of the accelerator 16, and supplies the controlled DC power to the DC motor 17 for driving. The direct differential gear supplied to this running DC motor 17 distributes the rotation of the electric motor 72 to rotate the running tires -H.

On the other hand, the AC generator I2 also supplies its output to the hydraulic pump driving DC motor 21 via the switch 23 to operate the working hydraulic pump 22, thereby operating the working machine as shown in the figure. The power is also supplied to the battery 25 via the switch 24 for charging.

This battery 25 has a capacity that can sufficiently supply current in response to fluctuations in the load applied to the AC generator 12, and can supply its DC output to the thyristor chopper control system rllts and the DC motor 21 for driving the hydraulic pump. ing.

Next, the operation of the embodiment of the present invention will be explained.

Figure 2 shows the AC generator 12 and battery 2 for load current.
5 shows the terminal voltage fluctuations during charging and discharging in No. 5, in which A shows the characteristics of the alternator 12, B shows the charging characteristics of the battery 25, and C shows the discharging characteristics.

The characteristic A changes depending on the rotational speed of the engine 11 and the amount of current of the exciter of the alternating current generator 1.2, but the characteristic can be freely defined by the control device 26. - If the characteristics of an alternating current generator that operates under the optimum fuel consumption condition are ■, and the battery 25 is connected to the alternator 12 that is operated according to this characteristic ■, the battery 25 becomes a load for the alternator 12, and the operating point N Operate. If a load is applied from this state, the voltage will decrease, but if the load is such that the voltage at the operating point S can be maintained, the alternator 12 will supply power to the load and provide charging power to the battery 25. supply The supply amount of this charging power is appropriately determined by the control device 26. l) When the voltage of the load is lower than the voltage value of the operating point S and higher than the operating point T,
All the power that can be supplied to the load is provided by the alternator 12. Then, the load increases further and the voltage drops to the operating point T.
When it is smaller than , power is supplied to the load from both the alternator 12 and the battery 25. At this time, if the voltage is higher than the voltage at the operating point Q, the AC generator 12 supplies more power to the load than the battery 25, and if the voltage at the operating point Q is lower, the electric oil 25 supplies more power than the AC generator 12. Provides power to the load.

That is, when the engine 11 is started and the switches 14 and 24 are closed, if the load is small, the terminal voltage of the alternator 12 is high, so the output of the alternator 12 is used preferentially, and excess energy is saved. is supplied to the battery 25 to charge it.

In order to prevent the AC generator 12 from becoming too large due to an increase in load, power is automatically supplied from the battery 25 to the load, thereby reducing load fluctuations to the engine II.

In this case, the alternating current generator 12 may be of any type as long as it fulfills its function, but in order to eliminate the need for a transformer, the alternating current generator 12 is
) The output voltage is controlled so as to be too high.

According to the present invention, the following excellent effects can be obtained.

(1) The engine can be operated in its optimum fuel efficiency state, and the engine is driven at constant rotation, resulting in fuel savings.

(2) Since the battery stores excess energy, a small engine is required for the load.

(3) Noise and exhaust gas can be reduced.

(4) It is possible to work only with batteries, and when working indoors, the work can be done without emitting noise or exhaust gas.

(5) By charging the battery, it can operate for a longer time than conventional battery-powered vehicles.

(6) No transformer is required.

(7) It can be configured to prevent electric shock.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating the configuration of an industrial vehicle according to an embodiment of the present invention, and FIG. 2 is a diagram showing the current of an alternator and battery.
It is a voltage characteristic diagram. ll...engine, 12...alternator, 13...
・Rectifier, 14, 23. 24... Switch, 15...
・Thyristor chopper control device, 16... accelerator,
17... Direct current motor for traveling, I8... Speed reduction device, I
9... Differential gear, 2o... Running tire, 21'...
... DC motor for driving hydraulic pump, 22 ... Hydraulic pump for work, 25 ... Battery, 26 ... Control device.

Claims (1)

[Claims] An engine that operates at a rotational speed that provides optimum fuel efficiency, an alternator that is driven by the engine, a rectifier that converts the alternating current output from the alternator into direct current, and a control that controls the output of the alternator. A device that supplies the DC output output from the rectifier to the traveling electric motor and the working machine electric motor, and also charges the battery when the electric power consumption of the traveling electric motor and the working machine electric motor is small, and An industrial vehicle characterized in that when electric power exceeds the output of the alternating current generator, electric power can also be supplied from the battery to the traveling electric motor and the working machine electric motor.