JP2004153938A - Large-sized transport vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a large-sized transport vehicle reduced in noise and exhaust gas. <P>SOLUTION: The multiple-axle large-sized transportation vehicle comprises a plurality of traction gears for rotating an axle shaft by a motor 5. It comprises a generator 12 for generating electricity by rotating an engine 11, a converter 14 which converts AC power generated by the generator 12 into DC power, an inverter 15 which converts DC power from the converter 14 into AC power which is supplied to the motor 5, and a battery 13 for changing generated power from the converter 14 and regenerative power from the inverter 15. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a large-sized multi-axle transport vehicle having a plurality of traveling devices, which is used for transporting inside a steelworks yard or the like, and more specifically, a hybrid power supply to an electric motor driven by an output of an engine generator. It relates to a large transport vehicle.
[0002]
[Prior art]
2. Description of the Related Art Steelworks and the like have conventionally used large-sized transport vehicles (hereinafter, simply referred to as “carriers”) called carriers when transporting products, materials, scraps, and the like on premises. 9 and 10 are a side view and a plan view showing such a carrier. For example, the carrier 100 has a total length of about 14 meters and is a transport vehicle capable of loading as much as 95 tons. The carrier 100 is provided with a loading platform 101 capable of loading a large transported object. , An appropriate number of traveling devices 102, 102,... The carrier 100 shown here is a 10-axis carrier provided with two traveling devices 102 on the left and right and five on the front and rear.
[0003]
Each traveling device 102 has a total of four tires, two on each side. A swing arm 112 that can swing vertically is pivotally attached to an arm of a suspension bracket 111 that is pivotally provided below the loading platform 101, and the swing arm 112 is jack-up supported by a hydraulic cylinder 113. It constitutes a mechanism.
[0004]
Also, in each of the traveling devices 102, 102..., An axle box is supported by a support shaft at the tip of a swing arm 112, and an electric motor (traveling motor) 121 for rotating an axle in the axle box and a suspension bracket 111 are turned. An electric motor (steering motor) 122 is provided. The traveling and steering of the carrier 100 are performed according to the operation of the steering wheel and the accelerator pedal in the driver's cab 103, and a command signal is sent from a carrier controller (not shown) to control the traveling motor 121 and the steering motor 122 of each traveling device 102, 102. Done.
[0005]
The carrier 100 shown here is electrically driven, has an engine 105 and a generator 106, and drives a traveling motor 121, a steering motor 122, and the like by electric power output from the generator 106. FIG. 11 is a block diagram showing a drive system for such an electric carrier.
The engine 105 and the generator 106 are mechanically directly connected, and the four-pole brushless AC generator sends hydraulic oil to the traveling motor 121, the steering motor 122, and the hydraulic cylinder 113 via inverters 131, 131. Is also directly connected to a hydraulic pump driving motor 123.
[0006]
A governor 132 is connected to the engine 105, and an AVR (Automatic Voltage Regulate) 133 is connected to the generator 106. The inverter 131 and the governor 132 are connected to a carrier controller 135 that transmits a control command signal according to the amount of depression of an accelerator pedal.
In such a drive system of the carrier 100, when traveling, it is necessary to increase the rotation speed of the engine 105 from the idling rotation speed to 1500 rpm or 1800 rpm. This is because the mounted generator 106 must maintain the rotation speed of the engine 105 at 1500 rpm when outputting 50 Hz AC, and 1800 rpm when outputting 60 Hz AC.
[0007]
When the carrier 100 travels, a torque command signal and a position command signal are sent from the carrier controller 135 to the inverter 131 in accordance with, for example, the amount of depression of the accelerator pedal and the rotation of the steering wheel. The electric power is converted into AC power and supplied to the traveling motor 121 to accelerate and decelerate the carrier 100 traveling. The carrier 100 has a traveling program according to a predetermined traveling route such as in a steel mill. At a point where the reference speed of the speed map corresponding to the torque command and the actual speed information from the inverter 131 are balanced, the torque command output is output. Is held.
[0008]
[Patent Document 1]
JP 2000-16609 A
[Problems to be solved by the invention]
By the way, such a carrier 100 of the related art, when running at a constant speed with a small load, or even when decelerating to temporarily stop, in order to obtain an alternating current of a predetermined frequency, the rotation speed of the engine 105 to 1500 rpm or 1800 rpm Had to continue. Accordingly, the carrier 100 that travels at a low speed (around 20 km / h) in a limited range in a steelworks should originally reduce the rotation speed of the engine 105 when traveling in a closed space such as a building where sound is heard. It was desirable to reduce the noise by lowering it, but that was not possible.
[0010]
Further, since the conventional carrier 100 has a single power source of the engine and the generator, the engine 105 and the generator 106 become large, requiring a large installation space in the carrier 100. Since the engine speed must be maintained at a high speed, fuel efficiency is low, and there is a problem of exhaust gas. This was a problem, in particular, in that noise and exhaust gas emitted from the carrier 100 traveling in a closed space in the building deteriorated the environment for people working there.
[0011]
Therefore, an object of the present invention is to provide a large-sized transport vehicle that reduces noise and exhaust gas in order to solve such problems.
[0012]
[Means for Solving the Problems]
The present invention relates to a generator that generates power by rotation of an engine and a converter that converts AC power generated by the generator into DC power in a large-sized multi-axle transport vehicle having a plurality of traveling devices that rotate an axle by an electric motor. And an inverter that converts DC power from the converter into AC power and supplies the AC power to the electric motor, and a battery that charges generated power from the converter and regenerative power from the inverter. .
[0013]
According to the present invention, the converter converts AC power from the engine generator into DC power, and converts the AC power into the target frequency and voltage AC power by the inverter, so that the final output becomes the generator output voltage and frequency. No longer depends. Therefore, it is possible to obtain electric power from the generator even when the rotation speed of the engine is reduced, and to drive the electric motor with the assistance of the electric power discharged from the battery, so that noise and exhaust gas can be reduced.
[0014]
Further, the large transport vehicle of the present invention has a controller for controlling the number of revolutions of the engine and the like, and is supplied from a battery in addition to the power generated by the generator at the time of acceleration by a control command signal from the controller. It assists discharge power, sends regenerative power from the electric motor to the battery during deceleration and charges the battery.Furthermore, when traveling at constant speed, the vehicle travels only with the power generated by the generator, and travels with the power generated by the generator. It is desirable to control the charging of the battery while the vehicle is running or the running of the vehicle using only the discharged power from the battery.
[0015]
Further, in the large-size transport vehicle of the present invention, the allowable rotation amount of the battery is set in advance, and the rotation speed of the engine is set so that the generator generates electric power obtained by subtracting the amount of the allowable discharge power of the battery from the required power required for acceleration. Desirably, it is controlled by a controller.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of a large-sized transport vehicle according to the present invention will be described below with reference to the drawings. The large-sized transport vehicle according to the present embodiment is a carrier of the same type as that described in the conventional example, and FIGS. 1 and 2 show a side view or a plan view thereof. The carrier 1 of the present embodiment is also a multi-axle large-sized transport vehicle in which the carrier 2 is provided with a jacking-up mechanism on the ten traveling devices 3, and the carrier 2 is moved up and down and the traveling motor is operated by operating an accelerator pedal and a lifting lever. The forward / backward movement by the drive of No. 5 is performed.
[0017]
Next, FIG. 3 is a block diagram showing a drive system in the carrier 1 of the present embodiment. Also in this carrier 1, the engine 11 and the generator 12 are mechanically directly connected, and the traveling motor 5 and the steering motor 6 are driven by electric power generated from the four-pole brushless AC generator. However, in the present embodiment, unlike the conventional one in which the traveling motor or the like is driven only by the power obtained from the generator, the battery 13 is provided so that the generator 12 is assisted by using the charging power. Of the hybrid type carrier.
[0018]
That is, in the drive system of the present embodiment shown in FIG. 3, the generator 12 generates electric energy from the mechanical energy generated by driving the engine 11, and the electric energy is transmitted through the power assist converter 14 and the inverter 15. A series hybrid is sent to the steering motor 6 and converted into mechanical energy there to drive the vehicle. A power assist converter 14 connected to the generator 12 converts AC power to DC power, and an inverter 15 connected to the power assist converter 14 converts DC power to AC power and converts the power to the traveling motor 5 and the steering. The motor 6 is supplied.
[0019]
The AC power from the generator 12 is once converted into DC power by the power assist converter 14 and sent to the inverter 15 to be converted back into AC power. This is because the final output is made independent of the generator output voltage and frequency by converting the power into AC power of the target frequency and voltage by the inverter 15. Here, the power assist converter 14 has a function of converting 220 to 440 V AC to 280 to 380 V DC, and has a specific configuration as shown in a block diagram in FIG.
[0020]
The power assist converter 14 includes a converter 21 having the conversion function of converting AC power to DC power, and the converter 21 is connected to a control circuit 22 for driving and controlling by a command signal from the carrier controller 16. Have been. The power assist converter 14 has a gate 23 driven by a control signal from the control circuit 22, and converts the power generated by the generator 12 and the regenerative power obtained by causing the traveling motor 5 to function as the generator 12. The battery 13 is connected to the power assist converter 14 via a gate 23 so that the battery can be charged.
[0021]
Returning to FIG. 3, the generator 12 is connected to a hydraulic pump driving motor 17 that feeds hydraulic oil to a hydraulic cylinder or the like of the traveling device 3. A governor 18 for adjusting the rotation speed is connected to the engine 11, and the output voltage of the generator 12 is adjusted by variably exciting the field winding with a field current 19. The generator 12 keeps the field current constant, and its output (voltage, frequency) changes according to the rotation speed. In the present embodiment, the field current is adjusted so that the generator output becomes maximum at 1500 rpm. Have been.
[0022]
As shown in FIG. 5, the input range of the power assist converter 14 is a frequency 25 Hz generated by the generator 12 at a rotation speed of 750 rpm of the engine 11, a frequency of 50 Hz output from the output of a voltage 220 V at a rotation speed of 1500 rpm, It is between the outputs of the voltage 440V.
On the other hand, the carrier controller 16 that transmits various control command signals in response to the depression amount of the accelerator pedal 20 and the rotation of the steering wheel is connected to the power assist converter 14 as described above, and further connected to the inverter 15 and the governor 18. Have been.
[0023]
Next, traveling of the carrier 1 in the present embodiment will be described. The carrier 1 of the present embodiment enables efficient running by appropriately using the discharge power from the battery 13 in addition to the power generated by the generator 12. Therefore, in the case where the carrier 1 transports luggage in the yard of a steelworks, for example, as shown in FIG. 6, an operation pattern in which the carrier 1 reciprocates between a loaded state and an empty state is assumed, and the required power at this time is simulated. The battery consumption and the fuel consumption between the carrier 1 of the embodiment and the conventional carrier 100 were confirmed.
[0024]
The operation pattern of the carrier 1 shown in FIG. 6 is based on the assumption that the carrier 1 reciprocates in a predetermined section by repeating traveling, that is, traveling at a constant speed and then decelerating. In addition, the speed of the carrier 1 at a constant speed is 25 km / h even when the carrier 1 is empty, and the speed is further reduced to 15 km / h when the carrier 1 is loaded. Run at a constant speed.
[0025]
In the carrier 1 according to the present embodiment, first, at the time of acceleration under load, assist of the discharge power supplied from the battery 13 in addition to the power generated by the generator 12 is performed, and at the time of deceleration, the regenerative energy from the traveling motor 5 is used. The battery is sent to the battery 13 for charging. When the vehicle is traveling at a constant speed, the battery 13 is charged while the vehicle runs only with the electric power generated by the generator 12 depending on the difference between the loaded state and the empty state. The case is further divided into the case where the vehicle travels only with the discharge power from the battery 13.
[0026]
FIG. 7 is a diagram showing a required power chart in the hybrid type carrier 1 according to the present embodiment. Similarly, FIG. 8 shows a required power chart in the conventional electric carrier 100. Therefore, a description will be given below while comparing these.
As shown in FIG. 8, both the hybrid type carrier 1 and the electric type carrier 100 require 105 kW of electric power during acceleration, 102 kW of electric power in a loaded state, and 43 kW of electric power in an empty state when traveling at a constant speed. I do. The power consumption in this case includes not only the power consumption for driving the traveling motor 5 but also the power consumption for driving the steering motor 6 and other control systems.
[0027]
When the inverter 131 is directly connected to the generator 106 like the electric carrier 100 (see FIG. 11), the voltage and frequency of the power output to the traveling motor 5 and the like depend on the generator output voltage and frequency. As shown in FIG. 8, the rotational speed of the engine 11 must be constantly maintained at 1500 rpm or 1800 rpm in any of the running states of acceleration, constant speed, and deceleration. This does not change whether the carrier is loaded or empty.
[0028]
On the other hand, in the hybrid type carrier 1 of the present embodiment, as shown in FIG. 7, for example, during acceleration, the required power is obtained with 57 kW of power from the generator 12 and 48 kW of power from the battery 13. ing. This is because the allowable discharge amount of the battery is preset from the carrier controller 16 to the power assist converter 14, and the electric power obtained by subtracting the required electric discharge power of 48kW from the required electric power required for acceleration of 105kW, that is, the electric power of 57kW The rotational speed of the engine 11 is controlled by a command signal sent from the carrier controller 16 to the governor 18 so that the generator 12 generates power.
[0029]
A command signal to the governor 18 for adjusting the rotation speed of the engine 11 has a rotation speed-output characteristic map in the carrier controller 16, and a command signal for rotating the engine 11 at a rotation speed of 860 rpm during acceleration is selected. , The command signal is sent from the carrier controller 16 to the governor 18.
On the other hand, a torque command signal corresponding to the amount of depression of the accelerator pedal 20 is output from the carrier controller 16 to the inverter 15, and a point at which the reference speed of the speed map corresponding to the torque command and the actual speed information from the inverter 15 are balanced in advance. Thus, various torque command outputs are held.
[0030]
Although the electric power required for traveling varies depending on the loaded load, it is determined here merely by distinguishing between a loaded vehicle and an empty vehicle. This is because the power supplied to the inverter 15 varies depending on the load, and requires 102 kW in the loaded state and 43 kW in the empty state.
[0031]
The carrier controller 16 detects a battery current signal through the control circuit 22 in the power assist converter 14 and calculates the amount of battery charge / discharge by integrating the battery current signal with time. Therefore, when the remaining capacity level falls below an arbitrarily set remaining capacity level, the power assist from the battery 13 is stopped and the vehicle runs only with the power generated from the generator 12. Apply recovery charging with electric power. Therefore, for example, when the charge / discharge amount is lower than the remaining capacity level when the vehicle is traveling at a constant speed in a loaded state, the rotation speed of the engine 11 is reduced to 1500 rpm which is the upper limit of the input range of the power assist converter 14 as shown in FIG. To obtain the required power of 102 kW only from the generator 12.
[0032]
On the other hand, when the vehicle is in an empty state and the charge / discharge amount is not lower than the remaining capacity level, the number of revolutions of the engine 11 is reduced to 650 rpm, which is lower than the input range of the power assist converter 14, and the idling state is set. The vehicle may be driven only by the discharge power from the vehicle.
Furthermore, when the vehicle is in an empty state and the charge / discharge amount is lower than the remaining capacity level, the rotation speed of the engine 11 is increased to 1200 rpm to run while charging, and the power generated from the generator 12 is reduced. The battery 13 is charged while being used for traveling.
[0033]
Next, since power supply to the traveling motor 5 is not required at the time of deceleration, the discharge power of the battery 13 is used for driving the steering motor 6 and other control system power consumption. Therefore, at the time of deceleration, the engine 11 drops the rotation speed to 650 rpm to bring it into an idling state. When the carrier 1 is temporarily stopped, the engine 11 is similarly set to the idling state.
Then, during regenerative braking, the braking power generated by the traveling motor 5 is regenerated from the power assist converter 14 to the battery 13 via the inverter 15 in order to regenerate and store the braking force into electric power during deceleration.
[0034]
Therefore, conventionally, in order to output AC power of a fixed frequency, the number of poles of the generator and the engine speed were limited, so that the operation efficiency was poor. However, in the present embodiment, as shown in FIG. By using the electric power discharged from the battery 13 and operating the engine at the highest efficiency while appropriately charging, the fuel efficiency of the engine can be greatly improved. Specifically, when the electric carrier 100 and the hybrid carrier 1 are compared with each other, the result that the fuel efficiency can be improved by 10% or more is obtained.
[0035]
In addition, in the case where the carrier 1 travels with the discharge power from the battery 13, the engine 11 can be brought into an idling state in which the number of revolutions of the engine 11 is reduced to 650 rpm. In this case, it is possible to reduce the number of revolutions of the engine 11 and to reduce noise and exhaust gas.
Further, when it is desired to increase the output of the generator, the number of poles is limited. Therefore, the conventional carrier 100 is provided with a large engine displacement and a large generator capacity. Although there was a tendency to increase the weight, in the present embodiment, the required electric power can be obtained by the electric power assist from the battery, so that the size can be reduced. Specifically, the engine displacement was reduced by 25 percent and the generator capacity was reduced by 40 percent.
[0036]
As described above, one embodiment of the large-sized transport vehicle has been described, but the present invention is not limited to this, and various changes can be made without departing from the gist thereof.
For example, in the above-described embodiment, the carrier is described as an embodiment of the large-sized transport vehicle. However, the present invention can be applied to an AGV or the like that automatically transports the vehicle.
[0037]
【The invention's effect】
The present invention provides a generator that generates power by rotation of an engine, a converter that converts AC power generated by the generator into DC power, and converts DC power from the converter into AC power and supplies the AC power to the electric motor. Since it has an inverter and a battery for charging the generated power from the converter and the regenerative power from the inverter, it has become possible to provide a large-sized transport vehicle with reduced noise and exhaust gas.
[Brief description of the drawings]
FIG. 1 is a side view showing a carrier according to an embodiment.
FIG. 2 is a plan view showing a carrier according to the embodiment.
FIG. 3 is a block diagram showing a drive system of the hybrid carrier according to the embodiment.
FIG. 4 is a block diagram showing a power assist converter.
FIG. 5 is a diagram showing an input range of a power assist converter.
FIG. 6 is a diagram showing a virtual driving pattern of a carrier.
FIG. 7 is a diagram showing a power requirement chart in the hybrid type carrier of the embodiment.
FIG. 8 is a diagram showing a power requirement chart in a conventional electric carrier.
FIG. 9 is a side view showing a conventional carrier.
FIG. 10 is a plan view showing a conventional carrier.
FIG. 11 is a block diagram showing a drive system of the electric carrier.
[Explanation of symbols]
Reference Signs List 1 carrier 3 traveling device 5 traveling motor 6 steering motor 11 engine 12 generator 13 battery 14 power assist converter 15 inverter 16 carrier controller 21 converter 22 control circuit

Claims (3)

In a large multi-axle transport vehicle equipped with a plurality of traveling devices that rotate the axle by an electric motor,
A generator that generates electricity by rotating the engine,
A converter for converting AC power generated by the generator into DC power,
An inverter that converts DC power from the converter into AC power and supplies the AC power to the electric motor;
A large-sized transport vehicle having a battery for charging generated power from the converter and regenerative power from the inverter. The large transport vehicle according to claim 1,
It has a controller that controls the number of revolutions of the engine, etc., and by a control command signal from the controller,
During acceleration, assists the discharge power supplied from the battery in addition to the power generated by the generator; during deceleration, sends regenerative power from the electric motor to the battery for charging; A large-sized transport vehicle that controls traveling by only electric power generated by a machine, charging of a battery while traveling by electric power generated by a generator, or traveling by only electric power discharged from a battery. The large transport vehicle according to claim 2,
The battery allowable discharge amount is set in advance, and the engine speed is controlled by the controller so that the generator generates power obtained by subtracting the battery allowable discharge power from the required power required during acceleration. A large-sized transport vehicle characterized by the following.

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