JP2005001775A - Hybrid scrap treatment machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out a stable work by suppressing fluctuation of load to an engine in a scrap treatment machine for exciting a lifting magnet by an output of a generator. <P>SOLUTION: The hybrid scrap treatment machine 10 is provided with the generator 21 driven by the engine 20; and the lifting magnet 17 excited by the output of the generator 21. A.C. power outputted by the generator 21 is converted to D.C. power by an inverter 22 to charge a battery 23. At that time, the inverter 22 outputs the D.C. power at a levelled current to charge the battery 23. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid scrap processor, and more particularly to a hybrid scrap processor that is not affected by engine load fluctuations.
[0002]
[Prior art]
Conventionally, as this kind of scrap processing machine, one in which a lifting magnet is attached to the tip of an arm is known as one of work attachments of a hydraulic excavator. And a hydraulic pump driven by the engine, a hydraulic motor rotating by the discharge oil of the hydraulic pump, and a generator driven by the hydraulic motor, and exciting the lifting magnet by the output of the generator Is formed.
[0003]
Here, when the operation switch of the lifting magnet is turned on / off, a peak current transiently flows to the coil of the lifting magnet. Moreover, since the coil of the lifting magnet is not warmed at the start of operation, the coil resistance is small and a large amount of current flows. When the coil of the lifting magnet is warmed up, the coil resistance increases and the current decreases and stabilizes. Therefore, at the start of operation, the hydraulic motor is overloaded and the pressure of the hydraulic pump increases. For this reason, an engine stall may occur if a load change occurs in the engine and it is significant.
[0004]
In order to overcome this problem, an operation detecting means for detecting the operating state of the generator is provided, and a decrease in the rotational speed of the generator is prevented by the generator control means based on the output signal, and the prime mover is controlled by the prime mover control means. A working machine with a lifting magnet configured to prevent a decrease in rotational speed is also known (see, for example, Patent Document 1).
[0005]
[Patent Document 1]
JP 2002-211183 A (pages 1 to 9, FIG. 1).
[0006]
[Problems to be solved by the invention]
The work machine described in Patent Document 1 detects the magnet temperature, the hydraulic oil temperature, the rotational speed of the generator, etc., drives the electromagnetic switching valve, and controls the set pressure of the supply oil passage relief valve, thereby controlling the hydraulic motor. The rotation is kept constant to prevent the lifting magnet from deteriorating.
[0007]
However, since the hydraulic pump pressure oil is supplied to the hydraulic motor to drive the generator, energy loss occurs, the hydraulic piping becomes longer, the pressure loss becomes large, the load on the engine is large, and the fuel efficiency is poor. There is a problem that.
[0008]
Therefore, in the scrap processing machine that excites the lifting magnet by the output of the generator, there arises a technical problem to be solved in order to perform stable work by suppressing the load fluctuation to the engine. It aims at solving this subject.
[0009]
[Means for Solving the Problems]
The present invention has been proposed to achieve the above object, and includes a generator driven by an engine and a lifting magnet excited by the output of the generator, and the AC power output from the generator is converted to DC. Provided is a hybrid scrap processing machine comprising an inverter that converts electric power and outputs this DC power to a battery with a current that is equalized, and a controller that supplies the electric power stored in the battery to a lifting magnet as required. To do.
[0010]
Because the generator can charge the battery with a constant load by the inverter, the generator does not need to output excessive power even when the peak current flows through the lifting magnet or when a high current is required. Is less affected by load fluctuations.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a hybrid scrap processing machine 10, in which an upper swing body 13 is placed on a lower traveling body 11 via a swing mechanism 12 so as to be rotatable. The upper swing body 13 is provided with a cab 14 on one front side thereof, and a boom 15 is attached to the front center portion so as to be able to be raised and lowered. Further, an arm 16 is attached to the tip of the boom 15 so as to be rotatable up and down, and a lifting magnet 17 is attached to the tip of the arm 16.
[0012]
FIG. 2 shows a control circuit of the hybrid scrap processing machine 10, which includes a generator 21 driven by the engine 20 and a lifting magnet 17 excited by the output of the generator 21. The AC power output from the generator 21 is converted into DC power by the inverter 22 and supplied to the battery 23. At this time, the inverter 22 outputs DC power with a leveled current to charge the battery 23.
[0013]
Here, the electric power stored in the battery 23 is supplied to the lifting magnet 17 via the controller 24. That is, when a request to excite the lifting magnet 17 is input to the controller 24 by turning on an operation switch (not shown), the controller 24 uses the current stored in the battery 23 with the current according to the request. The lifting magnet 17 is excited.
[0014]
Accordingly, even when a peak current transiently flows to the lifting magnet 17 when the operation switch of the lifting magnet 17 is turned on / off, a necessary current is supplied from the battery 23 to the lifting magnet 17 via the controller 24. Therefore, it is not necessary for the generator 21 to output excessive electric power, load fluctuations on the engine 20 can be suppressed, and stable work can be performed.
[0015]
It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.
[0016]
【The invention's effect】
As described in detail in the above embodiment, the present invention converts the AC power output from the generator into DC power by the inverter and outputs the DC power to the battery with a leveled current. The machine does not need to output the maximum power required by the lifting magnet, and the generator can be miniaturized to improve efficiency. In addition, since load fluctuations on the engine can be suppressed, stable work can be performed.
[Brief description of the drawings]
The figure shows an embodiment of the present invention.
FIG. 1 is a side view showing an example of a hybrid scrap processing machine.
FIG. 2 is a block diagram showing a control circuit of the hybrid scrap processing machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Hybrid scrap processing machine 17 Lifting magnet 20 Engine 21 Generator 22 Inverter 23 Battery 24 Controller

Claims (1)

A generator driven by the engine, and a lifting magnet excited by the output of the generator, converts the AC power output by the generator into DC power, and outputs the DC power to the battery with a leveled current A hybrid scrap processing machine comprising: an inverter that performs power supply, and a controller that supplies electric power stored in the battery to a lifting magnet as required.

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