JP2000289983A - Crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save energy and to reduce environmental pollution. SOLUTION: A power generator 6 is driven by an engine 5, the generated power is stored in a battery 7 through an inverter 24, and each electric motor 8, 18, 20, 21 for running, turning, and main winding and auxiliary winches are driven by battery storage force to perform each operation of running, turning, and winding up. Moreover, a hydraulic pump for boom 17 is driven by an electric motor for boom 16, and both boom raising and expanding and shrinking cylinders 14, 15 are operated by its discharge oil to raise and expand and shrink a boom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to self-propelled cranes such as wheel cranes (truck cranes, rough terrain cranes) and crawler cranes.

[0002]

2. Description of the Related Art The prior art will be described by taking a wheel type crane as an example.

A wheel type crane has an upper revolving structure mounted on a wheel type lower traveling structure, and a revolving device, a boom, a boom up / down and telescopic cylinder, and a winch for hoisting and lowering are mounted on the upper revolving structure. Traveling, turning,
Each operation of raising and lowering the boom and hoisting (further boom expansion and contraction in the case of a telescopic boom) is performed.

[0004]

However, the conventional wheel crane has the following problems.

[0005] Since the rated horsepower of the engine is set higher than normal load conditions in accordance with the assumed maximum output, power is basically wasted.

[0006] Even in the case of a light load that does not require large power, the engine speed must be increased when a high speed is required.
It will be operated in the rotational speed range where the speed is poor.

During the crane operation, the engine is operated at the idling speed to drive the hydraulic pressure of the auxiliary equipment such as the hoisting clutch and hoisting brake and the air conditioner even during the so-called idle time during which the hoisting operation is not actually performed. Must.

A pump is driven by an engine, and pressure oil from the pump is supplied to a hydraulic actuator via a control valve. A long pipe line between the pump and the actuator causes a large pressure loss. Poor energy transfer efficiency, such as waste of pump excess flow into the tank with a control valve or relief valve.

From these points, not only energy loss is large and fuel consumption is poor, but also pollution problems such as exhaust gas and noise have occurred.

Accordingly, the present invention provides a crane capable of realizing energy saving and low pollution.

[0011]

According to a first aspect of the present invention, an upper revolving unit is mounted on a lower traveling unit which can be moved by a traveling unit, and is rotatable about a vertical axis by a revolving unit. In a crane provided with a boom that can be raised and lowered by a boom raising and lowering device and a hoisting winch that can be hoisted and lowered by a hoisting device, a power generation device, a battery for storing power supplied from the power generation device, and a battery Comprising an electric motor driven by the stored power of
The motor is used to drive the above-mentioned traveling, turning, boom undulating, and hoisting devices.

According to a second aspect of the present invention, in the configuration of the first aspect, the power generation device includes an engine and a generator driven by the engine.

[0013] According to a third aspect of the present invention, in the configuration of the second aspect, the engine is rotated in a rotation speed region where the engine efficiency is good, and the battery is charged.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the state of charge of the battery is monitored, and the operation of the power generator is controlled in accordance with the state of charge. .

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the electric power generated by the regenerative control of the electric motor is stored in a battery.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a device whose final output is a rotary motion among the devices of traveling, turning, boom hoisting and hoisting is directly driven by an electric motor. The device whose final output is a reciprocating motion is configured so that a hydraulic pump is driven by an electric motor and a hydraulic cylinder is driven by hydraulic oil from the hydraulic pump.

According to a seventh aspect of the present invention, in any one of the first to fifth aspects of the present invention, of the devices operated by the hydraulic actuator among the devices of traveling, turning, boom hoisting and hoisting, the hydraulic pump is operated by an electric motor. The hydraulic actuator is driven and the hydraulic actuator is driven by pressure oil from the hydraulic pump.

According to an eighth aspect of the present invention, in any one of the first to fifth aspects, each of the traveling, turning, boom undulating, and hoisting devices is directly driven by an electric motor.

According to a ninth aspect of the present invention, in the configuration according to any one of the first to eighth aspects, the traveling device is driven by using both the power generator and the battery as power sources during traveling.

According to a tenth aspect of the present invention, in any one of the first to ninth aspects, the power generator is mounted on the upper swing body.

According to the above configuration, the electric power generated by the power generator is stored in the battery, and the electric motor is driven by the battery to perform each crane operation. (I) Only necessary power is supplied according to the operation. All right,
There is no need to wastefully raise the operating state of the power source (usually the engine speed).

(II) The power generator may basically be operated in an operating state in which the battery can be charged. In the case of an engine, the power generator is operated with priority given to efficiency (fuel consumption rate). Can be.

(III) Since the power generator and the electric motor as the drive source may be connected by electric wiring, energy transmission loss can be minimized.

In particular, by driving each device such as running, turning, boom hoisting, and hoisting directly by an electric motor (usually through a speed reducer), hydraulic pressure loss is eliminated.

From these points, it is possible to increase energy efficiency and reduce pollution such as exhaust gas and noise.

According to the fourth aspect of the present invention, the state of charge of the battery is monitored, and the operation of the power generator is controlled in accordance with the state of charge. When the power is reduced, the power source is activated or the number of rotations is increased, so that waste of energy can be further eliminated and energy efficiency can be further improved.

Furthermore, according to the configuration of claim 5, since the electric power generated by the regenerative control of the electric motor can be stored in the battery, the power storage effect can be enhanced and the energy can be further saved.

According to the structure of the sixth aspect, since the device whose final output is rotational motion is directly driven by the electric motor, there is no loss of driving force. On the other hand, with respect to a device whose final output is a reciprocating motion, the overall configuration can be made compact by a hydraulic drive system which is lightweight and easily outputs a large output.

According to the ninth aspect of the present invention, as an advantage peculiar to a self-propelled crane, it is suitable for a case where a large power is required such as when accelerating or climbing a hill.

By the way, in the case of the wheel type crane, the engine has been installed on the lower traveling body, and the power is mechanically transmitted to the axle via a transmission or the like.

However, since the engine is installed at the rear part of the frame of the undercarriage, the rear part of the frame must be bifurcated so that the engine can be accommodated, so that the rigidity and strength of the frame are unreasonable and the weight is reduced. growing.

On the other hand, according to the structure of claim 10,
Since the power generating device is installed on the upper revolving unit, the frame design of the lower traveling unit becomes easy, and a strong and highly rigid structure such as a box structure can be adopted. For this reason, it is possible to reduce the weight of the entire lower traveling body and thus the entire crane.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

First Embodiment (Refer to FIGS. 1 to 4) Here, an upper revolving unit 2 is mounted on a rough terrain, that is, a lower traveling unit 1 so as to be pivotable about a vertical axis. A flexible and telescopic boom 3,
A wheel-type crane provided with a cabin 4 used for both traveling and crane work is taken as an example to be applied.

FIG. 1 shows the rough terrain and its equipment arrangement. As shown in FIG. 1, the lower traveling body 1 includes an engine 5 constituting a power generator, a generator 6 driven by the engine 5, a battery 7 for storing power supplied from the generator 6, The driving motor 8 is installed, and the transmission 9 of the traveling device is driven by the traveling motor 8 so that the front and rear wheels 10,
11 rotates.

Reference numerals 12 and 13 denote front and rear axles (axles).

On the other hand, a boom raising / lowering cylinder 14 as a boom raising / lowering device for raising / lowering the boom 3 is provided on the upper rotating body 2.
A boom telescopic cylinder 15 as a boom telescopic device for expanding and contracting the boom 3, a boom electric motor 16 serving as a drive source of the boom raising and lowering and telescopic cylinders 14, 15, and a boom hydraulic pump 17 driven by the electric motor 16.
A turning electric motor 18 for driving a not-shown turning device (turning gear), a turning speed reducer 19 for reducing the rotational force of the electric motor 18 and transmitting the rotating force to the turning device, and a main winding and auxiliary not shown as a hoisting device. The main and auxiliary winding electric motors 20 and 21 and the electric motors 20 and 21 as drive sources of the respective winding winches.
Hoisting speed reducers 22 and 23 for reducing the rotational force of 21 and transmitting it to the winch are provided.

FIG. 2 shows a block configuration of a drive system and a control system of each of these devices.

In the figure, a solid arrow indicates an electric drive system, a dotted arrow indicates an electric regenerative system, an alternate long and short dash line arrow indicates a hydraulic drive system, and an alternate double dashed arrow indicates an operation or control signal system.

The generator 6 and each of the motors 8, 16, 18, 2
0, 21 and the battery 7, the inverter 24 converts the AC power generated by the generator 6 into DC and stores the DC power in the battery 7 (normal power storage operation). The AC power generated in each of the electric motors 8, 16, 18, 20, 21 is converted to DC by the regenerative operation accompanying the operation and stored in the battery 7 (regenerative power storage operation), and the power stored in the battery 7 is converted to AC. The electric motors 8, 16, 18, 20, 21 are supplied (discharge action).

An operating section (for example, a potentiometer, which is provided in the cabin 4 of FIG. 1 and operated by a lever 24a (or a pedal) for each motor,
In this case, only one of them is representatively shown) 24, and an operation signal of the operation unit 24 is sent to the controller 25.

The controller 25 performs the following operation.

(A) The motor 8,
The rotation direction and speed or torque of 16, 18, 20, 21 are controlled.

(B) The engine 5 normally operates in a rotational speed range with good energy efficiency (a specific rotational speed range may be used).
The engine controller 26 is controlled so as to rotate.

(C) The state of charge of the battery 7 is monitored via the inverter 24 (or directly), and the engine controller 26 is controlled so that a proper charge storage operation is performed. That is, when the charged amount of the battery falls below the predetermined value, the engine 5 is started or the engine speed is increased to increase the amount of power generation, and when the charged amount reaches the predetermined value, the engine 5 is decelerated or stopped to stop the power generation. Drop or stop.

The driving and controlling actions of this crane, including the actions (a) to (c) described above, will now be described.

When the engine 5 is operated, the generator 6 is driven to generate power, and the generated AC power is converted into DC by the inverter 24 and stored in the battery 7.

The electric motors 8, 16, 18, 20, and 21 are driven by the stored power of the battery 7.

Thus, with respect to the lower traveling body 1, the rotational force of the traveling electric motor 8 is transmitted to the front and rear wheels 10 and 11 via the transmission 9 and the axles 12 and 13.

As for the upper revolving unit 2, the revolving motor 1
8-The turning device is driven along the path of the turning speed reducer 19 to perform a turning operation, and the motor 2 for both the main winding and the auxiliary winch is used.
Both winches are driven on the path of 0,21-reduction gears 22,23 to perform a hoisting operation.

On the other hand, the rotational force of the boom motor 16 is transmitted to the boom hydraulic pump 17, and the discharge oil of the boom 17 causes the boom up-and-down and telescopic cylinders 14 and 15 to expand and contract, thereby causing the boom 3 to raise and lower and extend and contract. Is performed.

Here, since the rotation speed of the engine 5 and its fuel consumption rate have a relationship as shown in FIG. 3, in a normal operation other than the time of a large load, etc., an efficient rotation speed region Na (1600 to 1500) is used.
2200 rpm).

The electric motor is, for example, a brushless DC
In the case of an electric motor, the relationship between the rotation speed and the torque is as shown in FIG. 4, and the torque can be controlled by current control, and the rotation speed can be controlled by voltage control.

As the boom motor 16 and the boom hydraulic pump 17, a so-called integral actuator, that is, a motor and a bidirectional rotary pump driven by the motor are integrated as one unit, and the rotation direction and speed of the motor are controlled. With the control, the oil discharge direction and the oil discharge amount from the pump can be changed, and the oil discharge direction and the oil discharge amount can be individually used for boom raising / lowering and boom expansion / contraction. The use of this integral actuator can further save energy.

Further, the motors 8, 16, 18, 20, and 21 function as generators during traveling or crane work (for example, during traveling braking, downhill on a slope, braking under a winch or turning). (Regenerative action), and the regenerative electric power generated thereby can be stored in the battery 7. For this reason,
Energy consumption can be saved, and the size of the battery 7 can be reduced.

The inverter 24 is provided with a switching means (not shown), and the charging / discharging operation is switched by an operation of an operator or the like. Further, the inverter 24 is required for each electric motor, and may be installed separately for the lower traveling unit 1 and the upper revolving unit 2.

Second Embodiment (See FIGS. 5 and 6) In the following embodiments, only the differences from the first embodiment will be described.

In the first embodiment, the engine 5, the generator 6,
While the battery 7 is provided on the undercarriage 1, the second
In the embodiment, these are provided on the upper swing body 2.

In this way, compared to the case where the above-mentioned three members are provided on the undercarriage 1, there is no design restriction such as opening the rear part of the undercarriage 1 bifurcated so that the engine can be inserted. The design becomes easy, and a strong and rigid structure such as a box structure can be adopted. For this reason, it is possible to reduce the weight of the entire lower traveling body and thus the entire crane.

Since the upper revolving unit 2 has a relatively large space on the deck opposite to the cabin 4, the engine 5 and the generator 6 can be provided on the left deck portion.

Third Embodiment (See FIG. 7) In the third embodiment, the traveling device of the lower traveling body 1 is driven independently in the front-rear direction, that is, the front and rear transmissions 9f and 9b provided separately for the front and rear are used. A case is shown in which the present invention is applied to a system in which both side electric motors 8f, 8b are provided, and front and rear wheels 10, 11 are independently driven in front and rear by the two electric motors 8f, 8b.

In both the front and rear simultaneous drive system of the first and second embodiments and the front and rear independent drive system of the third embodiment, an in-wheel motor system in which an electric motor and a reduction gear are incorporated in the wheels 10 and 11 is used. May be adopted.

Fourth Embodiment (See FIG. 8) In the first to third embodiments, a so-called series system in which the front and rear wheels 10, 11 are driven only by an electric motor is adopted, whereas in the fourth embodiment, a so-called series system is used. A parallel system, that is, a system in which the front and rear axles 12 and 13 are driven by a main path of a battery 7-an inverter 24-a traveling motor 8-a transmission 9, and at the same time, driven by an auxiliary path of an engine 5-torque converter 27-a transmission 9. Is adopted.

Alternatively, a method may be adopted in which the traveling motor 6 is driven by both battery power and power generated by the generator 6.

This is advantageous when traveling, especially when large power is required, such as acceleration or climbing a hill.

Fifth Embodiment (see FIG. 9) The fifth embodiment exemplifies a case where the present invention is applied to a crawler crane.

The left and right traveling motors 28 are provided on the lower traveling body side.
L and 28R are provided, and the left and right crawlers (not shown) are driven to perform a traveling operation.

On the upper revolving structure side, an engine 29, an engine controller 30, a generator 31, an inverter 32, a battery 33, and a controller 34 are provided.
Motors 35, 36, 37, and 38 for turning, main winding winch, auxiliary winding winch, and boom hoisting winch are provided, respectively.
L, 28R, 35-38 are rotationally driven to travel, turn,
It is configured such that each operation of hoisting and raising and lowering the boom is performed.

As described above, the crawler crane travels,
Since the turning, boom hoisting, and hoisting devices all use the rotational motion as the final output, they can be directly driven by an electric motor (usually via a reduction gear), thereby eliminating hydraulic pressure loss.

Note that hydraulic auxiliary devices 39 and 40 are provided on both the lower traveling unit side and the upper revolving unit side, and these auxiliary units 39 and 40 are driven by an auxiliary pump 41 driven by the engine 29. The auxiliary devices 39 and 40 and the auxiliary pump 41
Usually, it is also provided in the wheel type cranes of the first to fourth embodiments. However, the auxiliary pump 41 may be driven by an electric motor instead of driven by the engine.

Further, in the case of a crawler crane, a lattice boom having a frame structure (non-stretchable type) is used for the boom, so that a boom extender is not required unlike a wheel type crane.

By the way, in the above embodiment, the power generator is constituted by the engine and the generator, but a fuel cell may be used as the power generator.

[0073]

As described above, according to the present invention, the electric power generated by the power generator is stored in the battery, and the electric motor is driven by this battery to perform each crane operation. Only necessary power needs to be supplied according to
There is no need to wastefully raise the operating state of the power source (usually the engine speed).

(II) Basically, the power generation device may be operated in an operating state in which the battery can be charged. In the case of an engine, the power generation device is operated with priority given to efficiency (fuel consumption rate). Can be.

(III) Since the power generator and the electric motor as the drive source may be connected by electric wiring, energy transmission loss can be minimized.

In particular, by driving each of the running, turning, boom up / down, and hoisting devices directly (usually via a speed reducer) by the electric motor as in the invention of claim 8, hydraulic pressure loss is eliminated.

From these points, energy efficiency can be increased and energy saving can be realized, and pollution such as exhaust gas and noise can be reduced.

According to the fourth aspect of the invention, the state of charge of the battery is monitored and the operation of the power generator is controlled in accordance with the state of charge. When the power is reduced, the power source is activated or the number of rotations is increased, so that waste of energy can be further eliminated and energy efficiency can be further improved.

Further, according to the fifth aspect of the present invention, since the electric power generated by the regenerative control of the electric motor can be stored in the battery, the power storage effect can be enhanced, and further energy saving can be realized.

According to the sixth aspect of the present invention, since the device whose final output is a rotary motion is directly driven by the electric motor, there is no loss of driving force. In addition, the overall configuration of a device whose final output is a reciprocating motion can be made compact by a hydraulic drive system which is lightweight and easily outputs a large output.

According to the ninth aspect of the present invention, as an advantage peculiar to a self-propelled crane, it is suitable for a case where a large power is required such as when accelerating or climbing a hill.

According to the tenth aspect of the present invention, since the power generating device is installed on the upper revolving structure, the frame design of the lower traveling structure is simplified, and a strong and highly rigid structure such as a box structure can be adopted. . For this reason, it is possible to reduce the weight of the entire lower traveling body and thus the entire crane.

[Brief description of the drawings]

FIG. 1 is a side view showing an overall configuration and equipment arrangement of a rough terrain crane according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a drive / control system in the embodiment.

FIG. 3 is a diagram showing a relationship between an engine speed and a fuel consumption rate.

FIG. 4 is a diagram showing a relationship between the number of rotations of the electric motor and torque.

FIG. 5 is a side view showing an overall configuration and equipment arrangement of a rough terrain crane according to a second embodiment of the present invention.

FIG. 6 is a block diagram of a drive / control system in the embodiment.

FIG. 7 is a block diagram of a drive / control system according to a third embodiment of the present invention.

FIG. 8 is a block diagram of a drive / control system according to a fourth embodiment of the present invention.

FIG. 9 is a block diagram of a drive / control system according to a fifth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lower traveling body 2 Upper revolving superstructure 3 Boom 5 Engine constituting power generating device 6 Same generator 7 Battery 24 Inverter 8 Traveling motor 9 Transmission constituting traveling device 10, 11 Same wheel 12, 13 Same axle 14 Boom raising / lowering cylinder 15 Boom Telescopic Cylinder 16 Boom Motor 17 Boom Hydraulic Pump 18 Swivel Motor 19 Swivel Motor 20 Main Winding Winch Motor 22 Same Reduction Gear 21 Supplementary Winch Motor 23 Same Reduction Gear 25 Controls each motor and Controller for controlling the engine speed according to the state of power storage 29 Engine in the case of a crawler crane 31 Generator 32 Inverter 33 Battery 34 Controller 28L, 28R Left and right traveling motors 35 Turning motor 36 Main winding winch motor 37 Supplementary winch Motor for boom hoisting winch

Claims (10)

[Claims] An upper revolving structure that is rotatable about a longitudinal axis by a revolving device is mounted on a lower traveling structure that can be traveled by the traveling device, and a boom that can be raised and lowered by a boom raising and lowering device is mounted on the upper revolving structure. Hoisting by hoisting device
In a crane provided with a hoisting winch capable of lowering, a power generator, a battery for storing power supplied from the power generator, and a motor driven by the stored power of the battery are provided. A crane characterized in that it is configured to drive each device for turning, boom raising and lowering, and hoisting. 2. The crane according to claim 1, wherein the power generation device includes an engine and a generator driven by the engine. 3. The crane according to claim 2, wherein the engine is configured to rotate in an engine speed range where engine efficiency is good and store the electric power in a battery. 4. The crane according to claim 1, wherein the state of charge of the battery is monitored, and the operation of the power generator is controlled in accordance with the state of charge. . 5. The crane according to claim 1, wherein electric power generated by regenerative control of the electric motor is stored in a battery. 6. The crane according to claim 1, wherein a device whose final output is a rotary motion among the devices of traveling, turning, boom hoisting and hoisting is directly driven by an electric motor, A crane characterized in that the device having a reciprocating motion drives a hydraulic pump by an electric motor and drives a hydraulic cylinder by hydraulic oil from the hydraulic pump. 7. The crane according to claim 1, wherein a device operated by a hydraulic actuator among the devices of traveling, turning, boom hoisting, and hoisting is driven by a hydraulic pump by an electric motor; A crane, wherein the hydraulic actuator is driven by pressure oil from the hydraulic pump. 8. The crane according to claim 1, wherein each of the traveling, turning, boom hoisting and hoisting devices is directly driven by an electric motor. 9. The crane according to claim 1, wherein the traveling device is driven by using both the power generator and the battery as power sources during traveling. 10. The crane according to claim 1, wherein the power generator is mounted on the upper swing body.