JPH0680042A - Fork lift driving device - Google Patents

Abstract

PURPOSE:To prevent environmental pollution when it is used indoors and so on by providing an induction machine, which operates as an electric motor by battery electric power supply, in a driving system of an engine and a hydraulic pump. CONSTITUTION:A fork lift vehicle 1 has a fork lift device which travels by being driven by operation of an engine 10 and raises and lowers a fork lift 6. An induction machine 31 which operates as an electric motor by battery electric power supply or operates as a generator by being driven by kinetic energy of the fork lift 6, is arranged in a flywheel 11 of this engine 10, and the induction machine 31 is used as a main machine at least by the battery electric power supply, and control to maintain the engine 10 in an idle running condition becomes possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive device of a system for driving a forklift for handling heavy goods as an industrial vehicle by changing the power source according to the work environment.

[0002]

2. Description of the Related Art Conventionally, a drive device for a forklift of this type has a structure in which a diesel engine is connected to a hydraulic pump via a torque converter, and always drives the hydraulic pump with the power of the diesel engine to generate hydraulic pressure. Then, the hydraulic pressure is guided to the lifting cylinder to lift and lower the fork to load and load the heavy object, and further guided to the hydraulic motor on the wheel side for traveling, and forklift work is performed so as to transport the heavy object of the fork.

[0003]

However, in the above-described conventional forklift drive device, since the power source is only the diesel engine, it has a great influence on environmental pollution particularly during indoor forklift work. That is, at present, an effective means for exhaust gas of diesel engine has not been found yet, and therefore, when the forklift work is repeated in an indoor environment, the exhaust gas of diesel engine is inevitably discharged indoors. It will be accumulated and will deteriorate the indoor environment. Therefore, as one of the measures for purifying exhaust gas of such a diesel engine, when the forklift is used indoors, it is considered to change to a power source other than the diesel engine to improve the working environment.

The present invention has been made in view of the above problems, and an object thereof is to drive the power source by changing the power source to either one of the engine and the electric energy of the battery depending on the working environment. , Including when working outdoors
Paying attention to the fact that harmful components in the exhaust of a diesel engine are extremely low when the load is low, and during light load work outdoors, or
It is an object of the present invention to provide a forklift drive device capable of improving the working environment, especially indoors, for a long time by supplementing the battery power with the induction machine when moving in an empty vehicle.

[0005]

To achieve this object, the present invention operates a drive system of a forklift engine and a hydraulic pump as an electric motor by at least a battery power source, and drives the hydraulic pump in an idling state of the engine. The main feature is to provide an induction machine for the retarder control device. In the indoor working environment, the hydraulic pump is driven by the induction machine to keep the engine idling and the forklift work is performed to improve the working environment.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a drive unit for a forklift according to the present invention. The forklift 1 is provided with a driver's seat 4 on a movable vehicle body 3 having wheels 2, and a mast 5 is provided substantially vertically on the front portion of the vehicle body 3. It is mounted and the fork 6 is mounted so as to move up and down along the mast 5. A diesel engine 10 is mounted inside the vehicle body 3, and a flywheel 11 on the engine output side is connected to a hydraulic pump 13 via a torque converter 12 and is driven by the engine power.

Further, in order to reduce environmental pollution when working indoors or the like, an electric drive means is added. This electric drive device is an induction machine 31 that operates as a generator and an electric motor in the retarder control device 30 already proposed by the applicant of the present application. The induction machine 31 is attached to the flywheel 11 so that the diesel engine 10 is put into a idling state and operated as an electric motor by electric energy, and the hydraulic pump 13 can be similarly driven. The driver's seat 4 is provided with a steering handle 14, a lifting lever 15, a traveling lever 16, an electric lever 17 for driving the pump by the induction machine 31, a power generation lever 18, and the like.

FIG. 2 is a block diagram showing in detail the forklift drive system. The hydraulic pump 13 is provided with a hydraulic control device 20 for hydraulically operating the forklift, and the induction machine 31 is provided with a retarder control device 30 for controlling it. It is provided. The hydraulic pump 13 of the hydraulic control device 20 pumps the oil in the oil pan 21 to generate a high hydraulic pressure according to the number of rotations. It is guided to a lift valve 24 operated by a lever 15. A hydraulic motor 25 is mounted on the wheel 2, and the traveling valve 23 operates to supply hydraulic pressure to the hydraulic motor 25 via an oil passage 26. Lifting cylinder 27 on fork 6
Is installed and configured to supply or discharge hydraulic pressure to one of the elevating cylinders 27 via the oil passage 28 according to the operation of the elevating valve 24.

In the retarder control device 30, the induction machine 31 has a flywheel 11 provided with a rotor portion 31a composed of a rotor side core and a coil, and a flywheel housing 11 '.
Is provided with a stator portion 31b including a stator-side core and a coil. And these rotor part 31a and stator part
31b are arranged close to each other in the radial direction and are configured to operate as an electric motor by advancing the rotating magnetic field of the stator part 31b with respect to the rotor part 31a, and to operate as a generator by delaying the magnetic field. It

The induction machine 31 is connected to a battery 33 via an inverter circuit 32, and a charging circuit 34 and a discharging circuit 35 are connected to the battery circuit. The operation signal of the electric lever 17 is input to the discharge circuit 35 and the rotating magnetic field advance circuit 36, and the operation signal of the power generation lever 18 is input to the charging circuit 34 and the rotating magnetic field delay circuit 37. The rotating magnetic field advance circuit 36 is the rotor portion 31 of the induction machine 31.
The frequency signal of the rotating magnetic field advanced by a predetermined amount is generated and output to the inverter circuit 32 based on the relationship between the signal from the rotation sensor 38 that detects the rotation speed of a and the operation signal of the electric lever 17. The rotating magnetic field delay circuit 37 is configured to generate a frequency signal of the rotating magnetic field delayed by a predetermined amount in relation to the signal from the rotation sensor 38 and the operation signal of the power generation lever 18 and output the frequency signal to the inverter circuit 32. .

Next, the operation of this embodiment will be described. First of all, when using the forklift 1 outdoors,
The worker rides on the driver's seat 4 of the vehicle body 3 and operates the diesel engine 10 as in the conventional case. Then, the power of the diesel engine 10 is driven by increasing the torque ratio in the torque converter 12 and transmitting it to the hydraulic pump 13. At this time, if the engine power is changed by stepping the accelerator pedal, the hydraulic pressure corresponding to the engine power is changed. To occur. Then, when the operator operates the elevating lever 15 to the ascending side, hydraulic pressure is supplied to the elevating cylinder 27 by the elevating valve 24 and the cylinder elongates, whereby the fork 6 lifts a heavy object. When the traveling lever 16 is operated in this state, hydraulic pressure is supplied to the hydraulic motor 25 by the traveling valve 23 to rotate the wheels 2, which causes the forklift 1 to travel and transport heavy objects to a predetermined place. To do. Then, when the elevating lever 15 is operated to the lower side at that location, the elevating cylinder 27 is drained and contracted, and a heavy object is placed on the ground or the like. Such forklift work is repeatedly performed.

When the diesel engine 10 is moved back to the loading place for heavy objects and the battery charge is insufficient, the power generation lever 18 in the retarder control device 30 is operated to a predetermined power generation position during the work. Then the rotating magnetic field delay circuit
A frequency signal with a predetermined delay is input to the inverter circuit 32 from 37, and a rotating magnetic field delayed with respect to the rotor part 31a is generated in the stator part 31b of the induction machine 31. Therefore, for example, in the diesel engine 10, at high speed, the induction machine 31 operates as a generator to generate electric power, and this electric energy is converted into direct current by the inverter circuit 32, the voltage is adjusted by the charging circuit 34, and the battery 33 is charged. Will be.

On the other hand, when the forklift 1 is used in a work environment such as indoors, the diesel engine 10 is kept idle (idle state). Then, the operator operates the electric lever 17 of the retarder control device 30, inputs a signal according to the amount of advance from the rotating magnetic field advance circuit 36 to the inverter circuit 32, and causes the stator portion 31b of the induction machine 31 to rotate to the rotor portion 31a. A rotating magnetic field that advances in the opposite direction is generated. On the other hand, since the battery 33 is sufficiently charged by the above-described operation of the induction machine 31 as a generator, the discharge circuit 35 applies a high voltage from the battery 33. Then, the induction machine 31 operates as an electric motor and is rotationally driven, and the hydraulic pump 13 is driven by this induction machine power in the same manner as described above to generate high hydraulic pressure. Therefore, when the traveling lever 16 and the elevating lever 15 are operated, the forklift 1 travels and the fork 6 moves up and down, and the forklift work is performed as described above. In this case, the hydraulic pump 13 uses the battery power source for the induction machine 31.
Driven by, the diesel engine 10 emits very little gas and contains few harmful components, so that the pollution of the indoor working environment is greatly reduced.

The operation of the electric motor of the induction machine 31 can be used together when the diesel engine 10 is in operation. In this case, since the engine power is assisted by the induction machine 31 to be increased, the lift capacity is improved and the engine power can be further reduced, so that fuel consumption, exhaust gas and the like are also improved.

Although the embodiment of the present invention has been described above, the present invention is not limited to this. That is, FIG. 3 shows another embodiment, or the same parts as in FIG. 2 are shown with the same numbers. In this embodiment, the flywheel is provided with a clutch 14, which is connected to this mechanical transmission, and power is taken out to the oil pump 13a through the power take-out window of the multi-stage transmission 12a, and the generated hydraulic pressure is passed through the oil passage 22 to raise and lower the valve. Is combined with 24.
The output shaft of the multi-stage transmission 12a is connected to the rear axle 20b via the propeller shaft 16 to transmit power to the wheels.

[0016]

As described above, according to the present invention, in the drive system of the forklift, the drive system of the engine and the hydraulic pump is provided with the induction machine of the retarder control system which operates as an electric motor by the battery power source. The machine can drive the hydraulic pump instead of the engine to perform forklift work, and can effectively prevent environmental pollution when used indoors or the like. Since the induction machine operates not only as an electric motor but also as a generator, the battery can be charged by itself, and the lift capacity, fuel consumption, exhaust gas and the like can be improved by using the engine and the induction machine together.

[Brief description of drawings]

FIG. 1 is a side view of a fork wrist drive device according to a first exemplary embodiment of the present invention.

FIG. 2 is a configuration diagram showing the same details.

FIG. 3 is a view corresponding to FIG. 2 of a drive unit for a forklift according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Forklift 6 Fork 10 Diesel Engine 11 Flywheel 13 Hydraulic Pump 20 Hydraulic Control Device 30 Retarder Control Device 31 Induction Machine

Claims (3)

[Claims] 1. A forklift vehicle having a forklift device that is driven by the operation of an engine to travel and that lifts and lowers a fork, the flywheel of the engine being operated as an electric motor by a battery power source,
An induction machine that is driven by the kinetic energy of the engine or the forklift to operate as a generator is provided, and at least the induction machine can be controlled by the battery power source to maintain the engine in a idling state. Forklift drive device. 2. A forklift drive device having a hydraulic pump driven by the operation of an engine, traveling by hydraulic pressure generated by the hydraulic pump, and lifting and lowering a fork, wherein a fly of a drive system of the engine and the hydraulic pump is provided. A drive device for a forklift, wherein a wheel is provided with an induction machine of a retarder control device that operates as a motor at least by a battery power source and drives a hydraulic pump in an engine idling state. 3. The retarder control device applies a voltage of a battery to an induction machine by an operation signal of an electric lever and generates a rotating magnetic field that advances to the induction machine, and a rotating magnetic field delayed by the operation signal of the power generation lever to the induction machine. The drive device for a forklift according to claim 1, wherein the drive device is configured to charge the battery with the generated and generated electric energy.