JP2002010405A - Industrial vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traveling vehicle which is improved in the fuel efficiency of the engine. SOLUTION: The vehicle, which is provided with a control device 6 for controlling respective set revolving speeds of wheels 2, consists of respective drive motors 1 and invertors 3 of the wheels 2, an accelerator pedal 20 and a steering wheel 22. The respective rotating speeds of the wheels 2 are set according to a vehicle speed inputted by the operation of the accelerator pedal 20, the respective set rotating speeds of the wheels 2 are compensated according to the angle of change in the direction of the steered wheels effected by the steering wheel 22, and the compensated respective set revolving speeds are outputted to the invertors 3, so as to control the rotating speed of each of the wheels 2. In this constitution, the respective set revolving speeds of the wheels are compensated according to the angle of change in its direction effected by the operation of the steering wheel 22, thus enabling the vehicle to change its direction by the wheels 2 which are controlled by the compensated respective set rotating speeds.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial vehicle such as a wheel loader, and more particularly to a traveling drive device and a turning device for the vehicle.

[0002]

2. Description of the Related Art In an industrial vehicle (for example, a container carrier or a traveling vehicle), a generator is driven by driving a diesel engine, and an electric motor connected to wheels is used by using electric power generated by the generator. 2. Description of the Related Art A traveling drive device called a diesel-electric system has been developed which drives a vehicle by driving.

[0003] Further, a conventional steering device for an industrial vehicle is usually provided with a power steering device using a hydraulic circuit. In response to an operation of a steering wheel, pressure oil is supplied from the power steering device to a steering cylinder, and a steering wheel is provided. The steering is performed while changing the direction.

[0004]

However, since the above-mentioned turning device uses a large number of hydraulic circuits and mechanical mechanisms, the number of parts is large, the cost is high, and much work time is required for assembly and maintenance. There was a problem that.

Accordingly, an object of the present invention is to provide a diesel-electric type traveling vehicle that can be operated in the same manner as a power steering device and has reduced costs.

[0006]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, an engine serving as a driving source for a plurality of works and a generator connected to the engine are provided. An industrial vehicle capable of performing the plurality of operations, comprising a traveling electric motor for each wheel to be supplied with power, comprising a speed input unit of the vehicle, and a turning angle input unit of the vehicle, The rotation speed of each wheel is set according to the vehicle speed input by the speed input unit, and the set rotation speed of each wheel is corrected according to the turning angle input by the turning angle input unit. The vehicle is turned by controlling each wheel with the corrected set rotation speed.

Here, the speed input means is an accelerator pedal or an operation lever corresponding to the accelerator pedal. The turning angle input means is a handle or an operation lever corresponding to the handle.

According to the above construction, the rotational speed of each wheel is set in accordance with the vehicle speed input by the speed input means, and is further corrected in accordance with the turning angle input by the turning input means. The vehicle is turned by controlling each wheel with the corrected set rotational speed.

According to a second aspect of the present invention, in the first aspect of the present invention, a turning direction is obtained from a turning angle input by the turning angle input means, and the turning direction is determined based on the turning direction. Are determined, and the set rotation speeds are corrected so that the front inner wheel is delayed according to the turning angle and the rear inner wheel is advanced.

According to the above configuration, the turning direction is obtained from the turning angle input by the turning angle input means, and the inner wheel of the wheels is obtained from the turning direction. Each set rotational speed is corrected so that the inner wheel is delayed and the rear inner wheel is advanced.

The invention according to claim 3 is the invention according to claim 2, wherein the turning angle for a predetermined time is θ °, the distance from the center of the axle to the center of the wheel is a, and When the length of / 2 is c, the correction amount of each set rotation speed for a predetermined time is the front inner wheel correction amount = −EF the front outer wheel correction amount ++ EF the rear inner wheel correction amount = + E + F Outer ring correction amount = −E + F where E = 2πa × (θ / 2) / 360 F = {1 / cos (θ / 2)} × c−c.

According to the above configuration, the turning angle at the predetermined time is θ °, the distance a from the center of the axle to the center of the wheel, and the length c of the half of the wheel base are determined according to the predetermined time. A correction amount for each wheel is determined.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a traveling drive device for an industrial vehicle according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes an induction motor (an example of an electric motor) having a rotating shaft connected to the shaft of each of four wheels 2, and an inverter (running driving means) for driving each of the motors 1 An example) 3 is provided, and a braking resistor 4 that consumes regenerative braking energy of the motor 1 is connected to each of the two inverters 3.
Further, each motor 1 is provided with a rotation speed detector (rotation speed detector) 5 for detecting the rotation speed of the motor 1.

Each of the inverters 3 feeds back the rotation speed of the motor 1 detected by the rotation speed detector 5 and according to a rotation speed command value of the motor 1 inputted from a control device 6 to be described later. Perform control.

In FIG. 1, reference numeral 11 denotes a diesel engine (an example of an engine serving as a driving source for a plurality of operations). A generator 12 is mounted on a rotating shaft of the engine 11, and buckets, forks, clamps, and the like mounted on the vehicle are provided. Each shaft such as a hydraulic pump 13 for supplying pressure oil to the hydraulically driven cargo handling device 7 is connected. When the engine 11 rotates, electric power is generated in the generator 12, and the hydraulic pump 13 supplies the cargo to the cargo handling device 7. Pressure oil is supplied. Also diesel engine 11
Is rotated at 1800 rpm to obtain a 60 Hz alternating current.

The generator 12 has a field current controlled by a generator voltage regulator (AVR) 14 so that the generated voltage is constant, and the power generated by the generator 12 is Power is supplied to each of the four inverters 3 and the motor 1 via the power supply 15. In FIG. 1, reference numeral 18 denotes a battery for starting the engine 11, the generator 12, and the control device 6.

Reference numeral 20 denotes an accelerator pedal (an example of speed input means: an operating lever corresponding to an accelerator pedal). The depression angle of the accelerator pedal 20 is detected by an accelerator pedal angle detector 21, and the accelerator pedal 20 Step angle (for example, 10-50 ° / 0-10
0%) is input to the control device 6.

Reference numeral 22 denotes a steering wheel (an example of a turning angle input means: an operating lever corresponding to the steering wheel). The operating angle of the steering wheel 31 is determined by a steering angle detector.
23, the operating angle of the handle 22 (for example,-
A detection signal of 90 to + 90 ° / 0 to 100%) is input to the control device 6.

Reference numeral 24 denotes a forward / reverse operation lever for selecting the traveling direction of the forward / neutral / reverse vehicle. The forward / neutral / reverse traveling direction operation signal is input to the control device 6.

FIG. 2 is a block diagram of the traveling control of the control device 6. The control device 6 includes a rotation speed setting unit 31, an angle conversion unit 32, a determination unit 33, a differentiation unit 34, a moving distance calculation unit 35, a correction rotation speed calculation unit 36, an accumulation unit 37, a target rotation speed setting unit 38, and wheel selection. It comprises a unit 39, an assignment unit 40, and a rotation speed output unit 41.

The rotation speed setting unit 31 determines the depression angle of the accelerator pedal 20 (for example, 10 to 50 ° / 0 to 100%) detected by the accelerator pedal angle detector 21 as the set rotation speed of the motor 1 corresponding to the traveling speed. Convert to R

The angle converter 32 is a steering wheel angle detector.
The operating angle of the handle 22 detected by 23 (for example,-
90 to + 90 ° / 0 to 100%) to -90 ° (left) to 0
Convert to ~ + 90 ° (right).

The judging section 33 judges the turning direction of the handle 31 based on the operation angle of the handle 22 converted by the angle converting section 32 (when +, the right operation is judged, and when-, the left operation is judged).

The differentiating section 34 differentiates the operating angle of the handle 22 converted by the angle converting section 32 and outputs a turning angle (+ θ °) or (−θ °) per predetermined time.
Based on the turning angle ± θ ° of the predetermined time obtained by the differentiating unit 34, the moving distance calculating unit 35 sets the distance from the center of the axle to the center of the wheel to a and the length of half the wheelbase to c. At this time, as shown in FIG. 3, a first movement distance E for giving θ / 2 to the inner wheel and a second movement distance F for further advancing the axle in the refraction direction are calculated by equations (1) and (2).

E = 2πa × (θ / 2) / 360 (1) F = {1 / cos (θ / 2)} × cc (2) a = 1725 mm, c = 2565 mm FIG. 4 shows a list of the first moving distance E (mm) and the second moving distance F (mm) obtained by the above calculation. The moving distance calculation unit 35 searches this list based on the input turning angle ± θ ° at a predetermined time and inputs the first moving distance E per predetermined time.
And the second moving distance F may be output.

The correction rotation speed calculating section 36 is a moving distance calculating section.
Based on the first moving distance E and the second moving distance F per predetermined time calculated by 35, as shown in FIG.
The corrected movement amounts of the front outer wheel, the rear inner wheel, and the rear outer wheel are obtained by equations (3), (4), (5), and (6), respectively, and the obtained corrected movement amounts per predetermined time are calculated by the equations ( 7) Divide by (8), (9) and (10) to convert to the rotation speed of the motor 1. By these calculations, as shown in FIG. 3, the front inner wheel is delayed according to the turning angle, the rear inner wheel is advanced,
Further, a corrected rotation speed is determined so as to advance the front outer wheel and delay the rear outer wheel. In equations (3) to (10), (+) indicates advance and (-) indicates return.

Corrected moving amount of front inner wheel = −E−F (3) Corrected moving amount of front outer wheel = + E−F (4) Corrected moving amount of rear inner wheel = + E + F (5) Corrected moving amount of rear outer wheel = −E + F (6) Corrected rotational speed G _FI of front inner wheel = (− _EF ) / L (7) Corrected rotational speed G _{FO of} front outer wheel = (+ E−) F) / L (8) Corrected rotational speed G _BI = (+ E + F) / L of the rear inner wheel (9) Corrected rotational speed G _BO = (− E + F) / L of the rear outer wheel (10) The accumulating unit 37 accumulates the corrected rotational speeds of the front inner wheel, front outer wheel, rear inner wheel, and rear outer wheel calculated by the corrected rotational speed calculating unit 36 according to equations (11), (12), (13), and (14).

G _FI = G _FI + (− E−F) / L (11) G _FO = G _FO + (+ E−F) / L (12) G _BI = G _BI + (+ E + F) ) / L (13) G _BO = G _BO + (− E + F) / L (14) The target rotation speed setting unit 38 calculates the front inner wheel, front outer wheel, rear inner wheel, The set rotation speed R of the motor 1 obtained by the rotation speed setting unit 31 is added to the corrected rotation speed of the rear outer wheel by the equations (11), (12), (13), and (14), and the front inner wheel, the front outer wheel, and the rear The target rotational speed S of the inner wheel and the rear outer wheel is obtained.
That is, the set rotation speed (set rotation speed) R of each wheel is corrected by the corrected rotation speed.

Target rotation speed S _FI = R + G _{FI of the} front inner wheel (11) Target rotation speed S _FO = R + G _{FO of the} front and outer wheels (12) Target rotation speed S _{BI of the} rear inner wheel = R + G _BI. (13) Target outer rotational speed of the rear outer wheel S _BO = R + G _BO (14) Also, the wheel selector 39 inputs the turning direction of the steering wheel 31 obtained by the determining unit 33 and the forward / reverse operating lever 24. As shown in FIG. 5, the front left wheel 2, the front right wheel 2,
Rear inner left wheel, front outer wheel,
Select rear inner and rear outer wheels.

The allocating section 40 includes a target rotational speed setting section 38.
The target rotation speeds S _FI , S _FO , S _BI , and S _BO of the front inner wheel, front outer wheel, rear inner wheel, and rear outer wheel determined in the above are allotted to each wheel 2 selected by the wheel selection unit 39.

The rotation speed output unit 41 determines the target rotation speed S allocated to each wheel 2 by the allocation unit 38 based on the forward, neutral or reverse traveling direction operation signal input from the forward / reverse operation lever 24. When the vehicle is moving backward, a sign (-) is assigned. When the vehicle is neutral, all target rotation speeds S are set to 0 (zero).
A rotational speed command value is output to each inverter 3 of the front shaft left wheel 2, the front shaft right wheel 2, the rear shaft left wheel 2, and the rear shaft right wheel 2.

The operation of the above configuration will be described. engine
When the engine 11 is started, the engine 11 is rotated at a constant rotation speed of 1800 rpm, whereby the hydraulic pump 13 is driven, and the generator 12 starts generating electricity. Also AVR14
Thus, the generated voltage is controlled to be constant. The field current of the generator 12 is supplied from the battery 18 at the time of startup, and is supplied from its own generated current after startup.

When the accelerator pedal 20 is depressed and its operation angle is detected by an accelerator pedal angle detector 21 and is input to the control device 6, a set rotation speed R of the traveling motor 1 corresponding to the operation angle is obtained. When the steering wheel 22 is operated, the operation angle is detected by the steering wheel angle detector 23, and when it is input to the control device 6, the turning angle ± θ per predetermined time and the turning direction are obtained. The target rotation speeds S _FI , S _FI , of the front inner wheel, front outer wheel, rear inner wheel, and rear outer wheel depend on the turning angle ± θ ° per hour and the turning direction of the handle 22.
S _FO , S _BI , and S _BO are obtained. Further, based on the turning direction of the steering wheel 22 and the forward or neutral or reverse traveling direction operation signal input from the forward / reverse operation lever 24, the front left wheel 2, A front inner wheel, a front outer wheel, a rear inner wheel, and a rear outer wheel are selected from the shaft right wheel 2, the rear shaft left wheel 2, and the rear shaft right wheel 2, and the front inner wheel, the front outer wheel, the rear inner wheel, and the rear wheel are selected for each selected wheel 2. target speed S _FI of the outer _{ring, S FO, S BI, S} BO is assigned, the forward-reverse control lever of each wheel 2 in accordance with an input forward or neutral or reverse drive direction operation signal from 24 rotation speed command value Is set based on the target rotation speed, and is output to each inverter 3.

Each inverter 3 rotates each wheel 2 in accordance with the input rotation speed command value and the fed-back rotation speed of the motor 1 to control the running speed of the vehicle. Turns the vehicle. At this time, the front inner wheel is delayed, the rear inner wheel is advanced, the front outer wheel is further advanced, and the rear outer wheel is delayed, so that the center of refraction of the axle is located outward of the center of the vehicle in the vehicle width direction (lateral direction) as shown in FIG. , And the center of the axle is controlled to move toward the moved refraction center. The turning center of the vehicle is on a straight line extending in the vehicle width direction from the center of the vehicle, and the front axle and the rear axle are respectively directed to the turning center. Also, when traveling at a very slow speed, there may be wheels 2 (for example, front inner wheels) that rotate in the reverse direction while moving forward. When the rotation speed command value is (+), the vehicle travels in the direction of the front shaft (forward), and when the rotation speed command value is (-), the vehicle travels in the direction of the rear shaft (reverse). Necessary active power is supplied from the generator 12.

As described above, the rotation speed of each wheel 2 can be controlled independently, and the turning can be performed by providing a difference between the rotation speeds of the inner wheel and the outer wheel. The amounts E and F allow the center of refraction of the wheel 2 to move outward and the center of the axle to be controlled toward the moved center of refraction, so that the vehicle can turn without slipping. In addition, since the conventional power steering device is not required, the number of parts can be significantly reduced, so that the cost can be reduced and the working time can be reduced. Further, since the handle 22 is merely a means for inputting the turning angle, the rotation operation can be lightened, and the operation can be performed with a light force.

In the present embodiment, the rotation speed of the motor 1 is controlled by feeding back the rotation speed of the motor 1 in the inverter 3. However, the rotation speed is controlled by feeding back the rotation speed of the motor 1 to the control device 6. You can also do so.

Further, in this embodiment, the engine is a diesel engine, but it goes without saying that a gasoline engine may be used.

[0039]

As described above, according to the present invention, the rotation speed of each wheel is set in accordance with the vehicle speed input by the speed input means, and the turning angle input by the turning input means. The vehicle can be turned by each wheel being controlled by the corrected set rotational speed.

[Brief description of the drawings]

FIG. 1 is an electric control block diagram of an industrial vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control device for the industrial vehicle.

FIG. 3 is an explanatory diagram of traveling control of the industrial vehicle.

FIG. 4 is a sample data diagram of a corrected movement amount of travel control of the industrial vehicle.

FIG. 5 is an explanatory diagram of traveling control of the industrial vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Wheel 3 Inverter 5 Rotation speed detector 6 Control device 7 Cargo handling device 11 Engine 12 Brushless generator 13 Hydraulic pump 20 Accelerator pedal 21 Accelerator pedal angle detector 22 Handle 23 Handle angle detector 24 Forward / reverse operation lever

Claims (3)

[Claims] An engine serving as a driving source for a plurality of operations;
An industrial vehicle capable of executing the plurality of operations, comprising: a traveling electric motor for each wheel, which is supplied with power from a generator connected to the engine; a speed input unit of the vehicle; A turning angle input means for setting a rotation speed of each wheel in accordance with the vehicle speed input by the speed input means, and setting the rotation speed of each wheel in accordance with the turning angle input by the turning angle input means. An industrial vehicle characterized in that the vehicle is turned by correcting the set rotational speeds of the respective wheels and controlling the respective wheels with the corrected set rotational speeds. 2. A turning direction is obtained from a turning angle input by the turning angle input means, an inner wheel of the wheels is obtained from the turning direction, and a front inner wheel is delayed according to the turning angle.
The industrial vehicle according to claim 1, wherein each of the set rotational speeds is corrected so that a rear inner wheel advances. 3. The turning angle for a predetermined time is θ °, the distance from the center of the axle to the center of the wheel is a, and 1 /
Assuming that the length 2 is c, the correction amount of each set rotational speed for a predetermined time is the correction amount of the front inner wheel = −EF The correction amount of the front outer wheel = + EF The correction amount of the rear inner wheel = + E + F The rear outer wheel 3. The industrial vehicle according to claim 2, wherein E = 2πa × (θ / 2) / 360 F = {1 / cos (θ / 2)} × c−c. .