JP4668714B2 - Miwa management machine - Google Patents

Description

  The present invention relates to an improvement of a three-wheel management machine that includes one front wheel and two rear wheels, and that drives these two rear wheels with an engine.

2. Description of the Related Art Conventionally, there has been known a technique for improving the running stability of a three-wheel management machine in which one front wheel is a free wheel and two rear wheels are driven by an engine (see, for example, Patent Document 1).
JP 2001-299011 A (FIG. 1)

Patent document 1 is demonstrated based on the following figure.
FIG. 11 is a diagram for explaining the basic configuration of the prior art. The three-wheel management machine 100 includes a machine body 101 and a front wheel 102 at the front of the machine body 101, and the front wheel 102 is attached to a front fork 103. The front fork 103 is rotatably attached to the head pipe 104 of the fuselage 101 so that the front wheel 102 can be steered, and the front fork 103 is tilted forward so that the front wheel 102 has a caster angle δ and goes straight. It improves the running stability while increasing the stability.

  However, since the front wheel 102 of the three-wheel management machine 100 is a free wheel and does not apply a driving force, it easily slips to the front wheel 102 when climbing over the bag diagonally. For this reason, workability was bad.

  An object of the present invention is to provide a three-wheel management machine in which a slip is unlikely to occur on a front wheel when, for example, the vehicle gets over a bag diagonally.

In the invention according to claim 1, the left and right rear wheels are drive wheels, and one front wheel is a driven wheel and a steered wheel. A power assist motor is attached to such front wheels, and the power assist motor is operated when necessary. In this type of three-wheel management machine, this management machine has a front wheel target speed calculation unit for calculating the target rotation speed of the front wheel and a target rotation speed obtained from the front wheel target speed calculation unit in the range of 0.5 to 0.8. The management speed determination unit that determines the management rotation speed by multiplying the coefficient selected from the above, the actual speed acquisition unit that acquires the actual rotation speed of the front wheel from the speed sensor, and the actual rotation speed of the front wheel that is obtained from this actual speed acquisition unit When the actual rotation speed is lower than the management rotation speed, the power assist motor is energized and the actual rotation speed is greater than or equal to the management rotation speed. Ah Sometimes, characterized in that it comprises a front wheel motor control unit for performing control not energized power assist motor.

In the invention according to claim 2 , the front wheel motor control unit includes an upper limit speed storage unit that stores the upper limit rotation speed of the power assist motor, and an upper limit rotation speed obtained from the upper limit speed storage unit and a front wheel obtained from the actual speed acquisition unit. The upper limit speed comparison unit that compares the actual rotation speed of the motor and the relay provided in the circuit between the motor power supply and the power assist motor is turned off when the actual rotation speed exceeds the upper limit rotation speed in the upper limit speed comparison unit And a relay control unit.

The invention according to claim 3 is characterized in that the upper limit rotation speed is a no-load rotation speed of the power assist motor.

  In the invention according to claim 1, the three-wheel management machine energizes the power assist motor when the actual rotational speed is lower than the managed rotational speed, and does not energize the power assist motor when the actual rotational speed is equal to or higher than the managed rotational speed. A front wheel motor control unit is provided, and power is supplied only when the actual rotational speed of the front wheels is lower than the management rotational speed.

Only when the actual rotational speed falls below the management rotational speed, the power assist motor applies a driving force to the front wheels, so that the front wheels can be driven and controlled in accordance with the actual rotational speed of the front wheels.
Since the minimum power assist is applied to the front wheels only when the driving force of the front wheels is necessary, the front wheels are less likely to slip compared to the case where the front wheels do not have power assist.
Since it becomes difficult for the front wheels to slip, there is an advantage that workability can be greatly improved.

  In addition, since the minimum power assist is applied to the front wheels only when the driving force of the front wheels is necessary, electric energy can be saved and energy saving can be achieved.

Here, the coefficient of less than 1.0 used in the management speed determination unit is a value selected from the range of 0.5 to 0.8.
If the coefficient less than 1.0 is less than 0.5, even if the difference between the actual rotational speed of the front wheels and the target rotational speed increases, power assist is not performed by the power assist motor, the work time is extended, and workability is reduced. There is a problem of doing.

On the other hand, if the coefficient less than 1.0 is greater than 0.8, the operating rate of the power assist motor is increased, the capacity of the power assist motor needs to be increased, the size of the power assist motor is increased, and the cost of the motor is increased. Is bulky.
Therefore, a coefficient less than 1.0 is set to a value selected from the range of 0.5 to 0.8.
The coefficient less than 1.0 used in the management speed determination unit is set to a value selected from the range of 0.5 to 0.8, so that it is not necessary to increase the size of the power assist motor, thereby avoiding an increase in motor cost. can do.

In the invention according to claim 2 , the front wheel motor control unit includes a relay control unit that turns off the relay when the actual rotational speed exceeds the upper limit rotational speed, and the power assist motor rotates at a high speed exceeding the upper limit rotational speed. During this time, the power assist motor was disconnected from the power circuit.

Generally, when the power assist motor rotates at a high speed exceeding the upper limit rotational speed, regenerative braking of the power assist motor occurs.
However, according to the third aspect, since the power assist motor is disconnected from the power supply circuit while the power assist motor rotates at a high speed exceeding the upper limit rotational speed, regenerative braking can be eliminated.

In the invention according to claim 3 , since the upper limit rotation speed is the no-load rotation speed of the power assist motor, it can be easily set and the setting time can be shortened.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the following description, front / rear, left / right, and upper / lower are determined based on the passenger sitting on the passenger seat. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a three-wheel management machine according to the present invention. A three-wheel management machine 10 includes a front wheel frame 12 at a front portion of a machine body 11 formed of a steel frame and a steel plate so as to be steerable left and right. A work machine 15 that includes a front wheel 13 below the frame 12, a power assist motor 14 that drives the front wheel 13 substantially at the center of the front wheel frame 12, and performs various operations such as sowing, plowing, and weeding behind the front wheel frame 12. Is provided so as to be able to be lifted and lowered via a lifting mechanism 16, and a driver's seat 17 on which a passenger sits is provided at the rear of the working machine 15. 18L (only the left wheel 18L is shown), and fluid transmissions 22L and 22R (the left fluid transmission 22L) that change the rotational speed of the engine 21 to the upper left and right of the rear wheels 18L and 18R (only the left rear wheel 18L is shown). Look shown.) Equipped with a farm machine before one wheel two rear wheels with an engine 21 to the rear of the machine body 11.

  Reference numeral 23 denotes a steering handle for the front wheel 13, 24 and 24 denote steering rods interposed between the handle 23 and the front wheel frame 12, 25 denotes a steering shaft for the front wheel 13, 26 denotes a silencer, and 27 denotes raising and lowering of the work area 15. Cylinder.

A work machine shaft 31 is disposed in the lower part of the machine body 11 in the front-rear direction, a relay shaft 32 is connected to the front portion of the work machine shaft 31, and an input shaft 33 of the work machine 15 is attached to the relay shaft 32. Power transmission between the rear output shaft 34 of the engine 21 and the work machine shaft 31 is performed by a pair of pulleys 35 and 36 attached to the shafts 34 and 31 and a belt 37 wound around the pulleys 35 and 36. It is. Universal joints 38 and 39 are provided before and after the relay shaft 32.
The drive system for the rear wheels 18L and 18R (only the left rear wheel 18L is shown) will be described in the next figure.

  FIG. 2 is a plan view of the three-wheel management machine according to the invention. Arm members 41L, 41L, 41R, 41R are extended from the body 11 to the left and right, and the fluid transmissions 22L, 22R are extended to these arm members 41L, 41L, 41R, 41R. The rear wheel frames 42L and 42R are attached to the fluid transmissions 22L and 22R, and the rear wheels 18L and 18R are rotatably attached to the rear wheel frames 42L and 42R.

  The drive system of the rear wheels 18L, 18R includes output pulleys 44, 44 attached to the front output shaft 43 of the engine 21, input pulleys 46L, 46R attached to the input shafts 45L, 45R of the fluid transmissions 22L, 22R, and an input pulley. 46L, 46R and cog belts 47L, 47R, which are toothed belts that span between the output pulleys 44, 44. Then, the driving force of the engine 21 is transmitted to the fluid transmissions 22L and 22R.

  Further, sprockets (not shown) and chains wound around these sprockets are provided on the fluid transmissions 22L and 22R and the rear wheels 18L and 18R, and the driving force of the fluid transmissions 22L and 22R is transmitted to the rear wheels 18L and 18R.

  That is, in the three-wheel management machine 10, the three wheels 13, 18L, 18R can be driven independently, and all the wheels can be driven independently by providing driving means for each of the wheels 13, 18L, 18R. The fluid transmissions 22L and 22R are arranged at the front ends of the arm members 41L and 41R, and a part of the output of the engine 21 mounted on the airframe 11 is provided to the rear wheels 18L and 18R via the fluid transmissions 22L and 22R. To supply.

  The three-wheel management machine 10 directly drives the two rear wheels 18L and 18R provided on the left and right sides of the engine 21 with the engine 21 through the fluid transmissions 22L and 22R. On the other hand, one front wheel 13 is driven by a power assist motor 14.

  FIG. 3 is a principle diagram of the drive system of the three-wheel management machine according to the present invention. The three-wheel management machine 10 drives the two rear wheels 18L and 18R provided on the left and right by the engine 21 using the fluid transmissions 22L and 22R. At the same time, the generator 52 is rotated, and electricity generated by the generator 52 is supplied to the power assist motor 14, and the power assist motor 14 is used to drive one front wheel 13 that is a steered wheel.

In the three-wheel management machine 10, the left and right rear wheels 18L and 18R are drive wheels, and one front wheel 13 is a driven wheel and a steered wheel. A power assist motor 14 is attached to such a front wheel 13, and power is supplied when necessary. The assist motor 14 is operated.
The control unit 50 including the front wheel motor control unit that controls the rotation speed of the wheel will be described in detail later.

The output of the engine 21 is the sum of the driving force of the rear wheels 18L and 18R, the input to the power assist motor 14 for driving the front wheels, the driving force for driving the work implement 15, and the input to the generator 52. However, if the electromagnetic clutches 53 and 54 are disengaged, the power of the engine 21 can be entirely used to drive the generator 52. All the power generated by the generator 52 is stored in the battery 55.
In the figure, 56 is a turning angle sensor for detecting the turning angle of the front wheel 13, 57L and 57R are rear wheel speed sensors for detecting the rotational speed of the rear wheels 18L and 18R, 58 is a speed change lever, and 59 is the engine speed. This is an engine speed sensor that detects.

  The fluid transmissions 22L and 22R are usually called HST (Hydrotic Transmission) and incorporate a variable displacement swash plate type hydraulic pump and a hydraulic motor, and drive the hydraulic pump with input shafts 45L and 45R to generate hydraulic pressure. The oil having the hydraulic pressure is supplied to the hydraulic motor to rotate the hydraulic motor and output it to the output shafts of the fluid transmissions 22L and 22R (not shown). By changing the inclination angle of the swash plate from the outside The output shaft can be accelerated, decelerated, forwardly rotated, stopped, and reversely rotated while rotating the input shafts 45L and 45R at a constant rotational speed.

  FIG. 4 is a block diagram of the front wheel motor control unit according to the present invention. The control unit 50 of the three-wheel management machine 10 (see FIG. 1) includes a front wheel target speed calculation unit 71 that calculates the target rotational speed V1 of the front wheel 13, and The management speed determination unit 72 that determines the management rotation speed V2 by multiplying the target rotation speed V1 obtained from the front wheel target speed calculation unit 71 by a coefficient less than 1.0, and the actual rotation speed Vfact of the front wheel 13 is acquired from the speed sensor 73. An actual speed acquisition unit 74 that compares the actual rotational speed Vfact of the front wheels 13 obtained from the actual speed acquisition unit 74 with the management rotational speed V2 determined by the management speed determination unit 72, and the speed comparison unit. When the actual rotational speed Vfact is lower than the management rotational speed V2 at 75, the power assist motor 14 is energized. When the actual rotational speed Vfact is equal to or higher than the management rotational speed V2, the power assist motor 14 is energized. And a front wheel motor control unit 70 for performing control not energized Sutomota 14.

  In the front wheel target speed calculation unit 71, the target speed V1 is obtained based on the turning angle θ, the shift lever position information, the engine speed, and the like.

  In the management speed determination unit 72, the coefficient K is input by the coefficient input means 76a, and the management speed V2 is obtained by multiplying the coefficient K by the target speed V1 obtained by the front wheel target speed calculation unit 71.

By the way, assuming a three-wheel management machine in which the rear wheels are drive wheels and the front wheels are driven wheels, the actual rotational speed Vfact of the front wheels matches the target speed V1 when the front wheels are ideally rotating.
However, if the resistance acting on the front wheel increases due to a hook or the like, the actual rotational speed Vfact of the front wheel decreases. If this decrease is significant, it will hinder the traveling of the three-wheel management machine, so it is necessary to take measures.

  A decrease that would hinder travel is defined as a management (rotation) speed V2. When the actual rotational speed Vfact is lower than the management speed V2, the soundness of traveling is maintained by driving the front wheels with the power assist motor. If the actual rotational speed Vfact is equal to or higher than the management speed V2, there is no problem in traveling, so the front wheels are free rotating wheels.

  That is, the speed comparison unit 75 performs energization control of the power assist motor 14 when the actual rotational speed Vfact of the front wheels 13 is less than the management speed V2 of the front wheels 13, and the actual rotational speed Vfact of the front wheels 13 is the management speed V2 of the front wheels 13. De-energization control is performed at the above time.

Next, the appropriate value of the coefficient K is examined. This coefficient K is a value of 1.0 or less that determines whether or not the speed of the front wheels has decreased so as to hinder travel.
If the coefficient K is less than 0.5, even if the difference between the actual rotational speed Vfact of the front wheels 13 (see FIG. 3) and the management speed V2 of the front wheels 13 is increased, the power assist by the power assist motor 14 is not performed and the bag is slanted. In the case of getting over the vehicle, for example, slipping occurs, which causes a problem that the driving is greatly hindered.

Further, as the coefficient K approaches 1.0, the power assist motor 14 is frequently operated and electric energy is required. When the operating rate is high, it is necessary to increase the model number (size) of the power assist motor 14. On the other hand, even if the actual rotational speed of the front wheels is slightly reduced, there is no problem in traveling. The upper limit of the coefficient K is set to 0.8 in consideration of economy, practicality, and experience.
That is, it is desirable to set the coefficient K to a value selected from the range of 0.5 to 0.8.

  The coefficient less than 1.0 used in the management speed determining unit 72 is set to a value selected from the range of 0.5 to 0.8, so that slippage is unlikely to occur on the front wheels when climbing diagonally over the kite. Further, it is not necessary to increase the size of the power assist motor 14 (see FIG. 3), and an increase in the cost of the motor 14 can be avoided.

  So far, measures have been described for the case where the front wheels are subjected to resistance and become low speed, but there are cases where the front wheels become high speed due to downhill and unevenness. In this case, the motor becomes a generator and a brake called regenerative braking is applied, which hinders traveling. Therefore, in the present invention, the following regenerative braking measures are taken.

That is, the front wheel motor control unit 70 stores the upper limit speed input means 76b for inputting the upper limit speed Vmax of the power assist motor 14 (see FIG. 3) and the upper limit speed Vmax input by the upper limit speed input means 76b. The speed storage unit 77, the upper limit speed comparison unit 78 that compares the upper limit rotational speed Vmax obtained from the upper limit speed storage unit 77 and the actual rotational speed Vfact of the front wheel 13 obtained from the actual speed acquisition unit 74, and the upper limit speed comparison. A relay control unit 84 for turning off a relay 83 provided in a circuit between the battery 55 as the motor power supply 79 and the power assist motor 14 when the actual rotation speed Vfact exceeds the upper limit rotation speed Vmax in the unit 78; Prepare.
Here, the upper limit rotation speed Vmax is the no-load rotation speed Vm of the power assist motor 14.

  Since the upper limit rotation speed Vmax is the no-load rotation speed Vm of the power assist motor 14 (see FIG. 3), when the power generation voltage by the power assist motor 14 exceeds the power supply voltage of the power assist motor 14, Turn off control.

  The no-load rotation speed Vm of the power assist motor 14 is the maximum rotation speed rotated by the power supply voltage, and regenerative braking is canceled only when the power assist motor 14 rotates at a high speed exceeding the maximum rotation speed. did. Since the upper limit rotation speed is the no-load rotation speed of the power assist motor 14, it can be easily set and the setting time can be shortened.

  FIG. 5 is a diagram for explaining the relay according to the present invention and its peripheral circuits. The relay 83 is provided in a circuit between the power assist motor 14 and the battery 55 as the motor power supply 79, and is a relay control unit. 84 is a component for turning on or off the motor power supply 79.

  A capacitor C85 is provided between the power assist motor 14 and the relay 83 to store electricity generated by the power assist motor 14, and when the actual rotational speed Vfact of the front wheels exceeds the upper limit speed Vmax and the relay 83 is turned off, A resistor R86 for discharging electricity generated by the assist motor 14 is provided. D is a driver for the motor 14.

The operation of the three-wheel management machine configured as described above will be described below.
Returning to FIG. 4, the three-wheel management machine 10 (see FIG. 3) energizes the power assist motor 14 when the actual rotational speed Vfact is lower than the managed rotational speed V2, and the actual rotational speed Vfact is equal to or higher than the managed rotational speed V2. In some cases, a front wheel motor control unit 70 that performs control not to energize the power assist motor 14 is provided, and energization is performed only when the actual rotational speed Vfact of the front wheels 13 is lower than the management rotational speed V2.

  Only when the actual rotational speed Vfact is lower than the management rotational speed V2, the power assist motor 14 applies a driving force to the front wheel 13, so that the drive control of the front wheel 13 can be performed in accordance with the actual rotational speed Vfact of the front wheel 13.

  Since the minimum power assist is performed only when the driving force of the front wheels 13 is required, slipping or the like occurs on the front wheels 13 when riding over the heel diagonally, which causes a major obstacle to running. The workability can be greatly improved.

  In addition, it is not necessary to increase the size of the power assist motor 14, and the power assist motor 14 having a small capacity can be used. Thus, energy saving can be achieved and an increase in the cost of the motor 14 can be avoided.

  In addition, the front wheel motor control unit 70 turns off the relay 83 provided in the circuit between the motor power supply 79 and the power assist motor 14 when the upper limit speed comparison unit 75 causes the actual rotation speed Vfact to exceed the upper limit rotation speed Vmax. Therefore, the power assist motor 14 is disconnected from the motor power source 79 while the power assist motor 14 rotates at a high speed exceeding the upper limit rotational speed Vmax.

Occurs when the battery 55 is charged with electricity generated by the power assist motor 14 by disconnecting the power assist motor 14 from the motor power supply 79 when the power assist motor 14 rotates at a high speed exceeding the upper limit rotational speed Vmax. Thus, regenerative braking by the power assist motor 14 can be eliminated.
Furthermore, since the upper limit rotation speed Vmax is the no-load rotation speed of the power assist motor 14, it can be easily set and the setting time can be shortened.

  The present invention is suitable for a three-wheel management machine.

It is a side view of the three-wheel management machine concerning the present invention. It is a top view of the three-wheel management machine concerning the present invention. It is a principle diagram of the drive system of the three-wheel management machine which concerns on this invention. It is a block diagram of the front wheel motor control part concerning the present invention. It is a figure explaining the relay which concerns on this invention, and its periphery circuit. It is a figure explaining the basic composition of the conventional technology.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Three-wheels management machine, 13 ... Front wheel, 14 ... Power assist motor, V1 ... Front wheel target rotational speed, 71 ... Front wheel target speed calculating part, V2 ... Management rotational speed, 72 ... Management speed determination part, Vfact ... Front wheel actual Rotational speed 73 ... Front wheel speed sensor 74 ... Actual speed acquisition section 72 ... Management speed determination section 75 ... Speed comparison section 70 ... Front wheel motor control section Vmax ... Upper limit rotation speed of power assist motor, 77 ... Upper limit speed Storage part 78 ... Upper limit speed comparison part 79 ... Motor power supply 183 ... Relay 84 ... Relay control part Vm ... No-load rotation speed of the power assist motor.

Claims (3)

In the three-wheel management machine of the type in which the left and right rear wheels are drive wheels, one front wheel is a driven wheel and a steered wheel, a power assist motor is attached to such front wheels, and the power assist motor is operated when necessary.
This management machine manages the front wheel target speed calculation unit that calculates the target rotation speed of the front wheels, and the target rotation speed obtained from the front wheel target speed calculation unit is multiplied by a coefficient selected from the range of 0.5 to 0.8. A management speed determination unit that determines the rotation speed, an actual speed acquisition unit that acquires the actual rotation speed of the front wheels from the speed sensor, and a management rotation that determines the actual rotation speed of the front wheels obtained from the actual speed acquisition unit by the management speed determination unit A speed comparison unit for comparing with a speed, and when the actual rotation speed is lower than the management rotation speed in the speed comparison unit, the power assist motor is energized, and when the actual rotation speed is equal to or higher than the management rotation speed, A management machine comprising: a front wheel motor control unit that performs control so that the power assist motor is not energized . The front wheel motor control unit compares the upper limit speed storage unit that stores the upper limit rotation speed of the power assist motor, the upper limit rotation speed obtained from the upper limit speed storage unit, and the actual rotation speed of the front wheel obtained from the actual speed acquisition unit. An upper limit speed comparison unit that performs, and a relay control unit that turns off a relay provided in a circuit between the motor power supply and the power assist motor when the actual rotation speed exceeds the upper limit rotation speed in the upper limit speed comparison unit; Miwa tiller of claim 1 Symbol mounting, characterized in that it comprises a. The upper limit rotational speed, Miwa tiller of claim 1 or claim 2, wherein it is a no-load rotation speed of the power assist motor.

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