JP2002142308A - Travel control method for motor-driven industrial vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a travel control method which can avoid wasteful operation where an electric motor is driven at high revolution, while brakes are used, facilitates speed adjustment work and can improve smooth traveling perform of a motor-driven vehicle, regardless of the state of a traveling surface, and can be applied to various types of the work vehicles. SOLUTION: A left motor control value TG2L, which is a correction value of TG1L, is calculated in a step ST10L, by the formula: TG2L=Vmax×ACC%× 1-(BKL%+p×BKR%×ACC%)}. Traveling of a snowplow is controlled according to the left motor control value TG2L and a right motor control value TG2R is obtained in the same way. The left electric motor, therefore, is controlled so as to have the left motor control value lowered, if the left brake opening rate is large and to have the left motor control value further lowered, if the right brake opening rate is large. The right electric motor is controlled in similar way.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a left and right electric motors for driving left and right drive wheels, respectively, as a traveling system, and left and right brakes for adjusting the speeds of the left and right drive wheels, respectively. The present invention relates to an electric traveling work machine including an engine and a clutch interposed in a power transmission path from the engine to a work implement.

[0002]

2. Description of the Related Art
For example, Japanese Patent Application Laid-Open No. S51-137214 discloses a method of controlling a rotary snowplow equipped with an automatic speed control device. INDUSTRIAL APPLICABILITY The present invention is suitable for a rotary snowplow traveling on a railway, and according to the claims, `` to detect a load state of a snowplow prime mover and thereby control the traveling speed of the rotary snowplow. Did ".

[0003]

There is no problem with a rotary snowplow for railroad that simply moves forward or backward along the rail, but a snowplow that removes snow on general roads other than railways has no problem due to road surface conditions and the reaction of snow. Since the vehicle body swings to the left and right, the driver must always control the traveling direction, and the invention disclosed in the above-mentioned publication cannot be adopted in a general road snow plow.

Accordingly, an object of the present invention is to provide a traveling control technique applicable to various working machines such as a snow blower for removing snow on a general road.

[0005]

In order to achieve the above object, a first aspect of the present invention is a left and right electric motor for driving left and right drive wheels as a traveling system, and a left and right brake for respectively adjusting the speed of the left and right drive wheels. In an electric traveling work machine having an engine that drives a work implement as a work system and a clutch interposed in a power transmission path from the engine to the work implement, an accelerator lever operated by a driver and left and right speed adjustment operations Replace the lever position with the accelerator opening, the left brake opening, and the right brake opening, and read them into the control unit.The control unit reads the accelerator opening, left brake opening, and right brake opening. The left corrected brake rate is obtained by converting the accelerator rate, left brake rate, and right brake rate, and adding the left brake rate to the effect of the right brake rate. The left motor control value is determined by multiplying the obtained value by a correction coefficient of less than 1 determined according to the decrease in the intake negative pressure of the engine when the clutch is on, while obtaining the left motor control value. The right corrected brake rate is calculated by adding the effect of the left brake rate to the rate, and the accelerator rate is corrected with this right corrected brake rate.When the clutch is on, the obtained value is used to reduce the engine intake negative pressure. A right motor control value is obtained by multiplying the correction coefficient by a correction coefficient of less than one, and the right electric motor is controlled by the right motor control value.

When a large load is applied to the work implement, the intake negative pressure of the engine rises sharply. At this time, the outputs of the left and right electric motors are reduced to suppress the traveling speed.

[0007] Generally, the electric motor of the traveling system is directly controlled based on the accelerator opening. However, in the present invention, for example, when controlling the left electric motor, the left motor control value is reduced when the left brake opening is large, and when the right brake opening is large, the left motor control value is considered in consideration of this. Control for further lowering is performed.
The same applies to the right electric motor. Thus, the driver can freely control the traveling direction.

As a result, the waste of rotating the electric motor at a high speed while applying the brake can be avoided. In addition, the vehicle may shake due to the imbalance between the left and right motors. For example, for the left electric motor, not only the left brake opening but also the right brake opening is taken into consideration. And speed adjustment work is facilitated irrespective of the condition of the running surface, and the smooth running performance of the vehicle is also improved.

According to a second aspect of the present invention, the working implement is an auger for bringing snow and a blower for blowing off the collected snow, and the working machine is a snow blower. If the working tool is a tilling claw, the working machine is a cultivator, and if the working tool is a cutting blade, the working machine is a lawn mower, and there are various types of working tools and working machines. Among them, in the snow blower, the working tool is composed of the auger and the blower, and the form of the load acting on the working tool becomes complicated. Therefore, by applying the present invention to a snow blower, it is possible to perform efficient snow removal while protecting the auger and the blower while freely controlling the direction by controlling the left and right drive wheels.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. “Left” and “right” are based on the driver. FIG. 1 is a plan view of an electric traveling work machine according to the present invention. An electric traveling snow removing machine 10 as an electric traveling work machine includes left and right electric power supplied from a battery (not shown) housed under a body frame 11. Electric motors 13L, 13R (L indicates left, R indicates right, the same applies hereinafter) and drive shafts 14L, 14R
, And the left and right crawlers 16L, 16R are driven by drive wheels 15L, 15R provided at the ends of the drive shafts 14L, 14R.
Is an electric traveling work machine capable of driving the vehicle wheels and braking the drive wheels 15L and 15R with the left and right brakes 17L and 17R. The operation panel 21 includes one accelerator lever 22, left and right speed adjustment operation levers 23L and 23R, and one throttle lever 2.
5 is a vehicle. The driver operates the levers (including the accelerator lever 22, the speed adjustment operation levers 23L and 23R) on the operation panel 21 while walking from the rear without riding in the vehicle, so that the driver can move forward, backward, turn, and stop. The engine 31 is mounted on the machine base 20, and the clutch 32 and the work implement shaft 33 are mounted on the engine 31.
And the auger 35 as well as the blower 34 are turned. The speed of the engine 31 is adjusted by the throttle lever 25. 36 is an auger housing, and 37 is a snow throw chute.

That is, the transmission motors 13L and 13R, the drive wheels 15L and 15R, and the left and right brakes 17L and 17R.
Is the main part of the "running system", and this running system
0 is moved forward and backward (including turning). Engine 3
1, the clutch 32, the blower 34 and the auger 35 are essential parts of the "working system", and the snow removing work is performed by this working system.

A control unit 24 controls the electric motors 13L, 13R and the left and right brakes 17L, 17R based on the positions of the accelerator lever 22 and the speed adjusting operation levers 23L, 23R. Collectively control. The brakes 17L and 17R may be an electromagnetic brake for applying a brake by electromagnetic action, a hydraulic brake for holding a disc by hydraulic pressure, a mechanical brake for tightening a drum with a band, a regenerative brake or a similar brake. The type does not matter.

FIGS. 2A and 2B are principle diagrams of the clutch employed in the present invention. As shown in FIG.
0 is a drive pulley 38 attached to the output shaft of the engine 31
And a driven pulley 39 attached to the working tool shaft 33, a belt 41 stretched over the pulleys 38, 39, and a clutch cylinder 42 for tightening and / or loosening the belt 41. When the piston rod 43 of the clutch cylinder 42 is advanced, the belt 41 is in a tension state, so that power is transmitted from the pulley 38 to the pulley 39. That is, (a) shows a clutch-on state.

If the piston rod 43 of the clutch cylinder 42 is retracted in (b), the belt 41 is in a loose state, so that no power is transmitted from the pulley 38 to the pulley 39. That is, (b) shows the clutch off state.

FIGS. 3A to 3C are operation diagrams of the accelerator lever employed in the present invention. In (a), the accelerator lever 22 is an operation lever capable of covering forward, stop, and retreat with a single stroke, and capable of continuously switching both forward and backward from low speed to high speed. The position of the accelerator lever 22 is monitored by an accelerator potentiometer 26.

FIG. 2B is a graph showing the relationship between the position of the lever 22 and the output of the accelerator potentiometer 26. The output range of the accelerator potentiometer 26 is 0 to ++.
When 5 V (volts) is set, 0 V is assigned to the reverse high speed, +2.5 V to neutral (stop), and +5 V to the forward high speed.

(C) is a graph obtained by generalizing (b) and processing for the control of the present invention, wherein 0 V (vertical axis) is set for the retreat high speed (horizontal axis) and neutral voltage is set for stop (horizontal axis). Some V
n (vertical axis), Vmax which is the maximum voltage at high speed (horizontal axis)
Assigning (vertical axis) is the same as (b). By the way, when the driver sets the lever 22 in (a) to the vicinity of the forward high speed, the driver intends to perform the forward high speed, so that the modification of the control to be performed in the present invention is not applied. I will. In FIG. 3C, the V4 to Vmax (shaded) region on the vertical axis is a non-control region.

When the driver sets the lever 22 in (a) near the reverse high speed, the driver intends to perform the reverse high speed, so that the modification of the control to be performed in the present invention is applied. I will not do it. (C): 0 on the vertical axis
The region from V1 (shaded) is a non-control region.

Further, when the driver stops the lever 22 in (a) or sets the lever 22 to a very low speed, the driver intends to stop or perform the low speed at his / her own will. No control modifications will be applied.
In FIG. 3C, the V2 to V3 (shaded) region on the vertical axis is a non-control region. That is, in (c), V1 to V
The control of the present invention is performed in the range of 2 or V3 to V4.

FIGS. 4 (a) to 4 (c) are action diagrams of the speed adjusting operation lever employed in the present invention. The speed adjusting operation levers 23L and 23R are different from those in FIG. 1, but are changed for convenience of explanation of the operation. In (a), the left and right speed adjustment operation levers 23L, 23R are brake 0%.
This is an operation lever capable of continuously switching from (unbraked) to brake 100% (full braking). The position of the left speed adjustment operation lever 23L is monitored by the brake potentiometer 27L, and the position of the right speed adjustment operation lever 23R is monitored by the brake potentiometer 27L.
Monitor with R.

FIG. 4B is a graph showing the relationship between the positions of the levers 23L and 23R and the outputs of the brake potentiometers 27L and 27R.
When the output ranges of 7L and 27R are set to 0 to + 5V, it indicates that 0V is assigned to the brake 0% and + 5V is assigned to the brake 100%.

(C) is a graph that generalizes (b) and is processed for the control of the present invention. Assigning 0v to 0% of brake and Vmax to 100% of brake is as follows.
Same as (b) above. By the way, when the driver sets the lever 23L or 23R of (a) near the brake 100%, the driver intends to perform full braking, so the control to be performed in the present invention is modified. Will not apply. (C) V6 to Vma on the vertical axis
The x (shaded) area is an uncontrolled area.

When the driver operates the lever 23L or 23R shown in FIG.
Is set near 0% brake, braking is not applied by the driver's intention, so that the control modification to be performed in the present invention is not applied. (C) 0 to V5 on the vertical axis
Areas (shaded) are uncontrolled areas. That is, in (c), the control of the present invention is performed in the range of V5 to V6 on the vertical axis.

FIG. 5 is a control system diagram of the electric traveling work machine according to the present invention. When the left speed adjusting operation lever 23L is operated, a brake potentiometer 27L interlocked therewith is operated.
The left brake driver 28L operates the left brake 17L based on the output voltage of the left brake driver 28L. Similarly, when the right speed adjustment operation lever 23R is operated, based on the output voltage of the brake potentiometer 27R linked thereto,
The right brake driver 28R performs a braking operation on the right brake 17R.

If the throttle lever 25 is slid, the throttle driver 45 can adjust the opening of the throttle valve 46 provided in the intake pipe 44 of the engine 31. That is, as the throttle valve 46 is opened, the rotation speed of the engine 31 increases. 47 is an engine tachometer and 48 is an intake pressure sensor.

On the other hand, the control unit 24 controls the output voltage ACCV of the accelerator potentiometer 26 and the output voltages BKLV, BKR of the left and right brake potentiometers 27L, 27R.
V, the engine intake negative pressure is taken in, and a control voltage TG3L and a control voltage TG3R are generated by a control flow described later,
The left and right motors 13L and 13R are controlled via the left and right motor drivers 29L and 29R, respectively.

FIG. 6 is a control flow chart of the electric traveling work machine according to the present invention, wherein STxx is a step number, f is forward,
r is a subscript, L is left, and R is a subscript indicating right. ST01: Read the accelerator opening (equivalent to the output voltage of the accelerator potentiometer) ACCV. ST02: It is checked whether or not the read accelerator opening ACCV is equal to or higher than the neutral voltage Vn. As shown in FIG. 3C, if the voltage is equal to or higher than the neutral voltage Vn, it can be regarded as “forward”, and if not, “retreat”. ST0 if YES
If NO in 3f, the process proceeds to ST03r.

ST03f: If YES in ST02,
It is checked whether or not the accelerator opening ACCV is in the range of voltages V3 to V4. As shown in FIG. 3C, the voltages V3 to V4
Is a control range, and the other ranges are non-control ranges. Then, if NO, the process proceeds to E (end). ST04f: If accelerator opening ACCV is in the range of voltages V3 to V4, calculate the ratio of ACCV (acceleration rate ACC%) in this range. The calculation formula is the accelerator ratio A
CC% = (ACCV-V3) / (V4-V3).

ST03r: If NO in ST02, it is checked whether accelerator opening ACCV is in the range of voltages V1 to V4. As shown in FIG. 3C, the range of the voltages V1 to V2 is the control range, and the other ranges are the non-control range. Then, if NO, the process proceeds to E (end). ST04r: If accelerator opening ACCV is in the range of voltages V1 and V2, the ratio of ACCV in this range (accelerator ratio ACC%) is calculated. The calculation formula is the accelerator ratio A
CC% = (ACCV-V1) / (V2-V1).

ST05: Acceleration rate ACC% is determined by ST04f or ST04r. ST06L: Read the left brake opening (equivalent to the output of the left brake potentiometer) BKLV. ST07L: It is checked whether or not the read BKLV is in the range of voltages V5 to V6. In FIG. 3C, the voltage V5
Since the range from to V6 is the control range and the other ranges are the non-control range, if NO, the process proceeds to E (end). ST08L: If ST07L is YES, the range (V5 to V
Ratio of BKLV to 6) (Left brake rate BKL%)
Is calculated. The calculation formula is: left brake rate BKL% = (BK
(LV-V5) / (V6-V5).

Similarly, the following steps are executed for the right brake. ST06R: Read the right brake opening (equivalent to the output of the right brake potentiometer) BKRV. ST07R: It is checked whether or not the read BKRV is in the range of voltages V5 to V6. In FIG. 3C, the voltage V5
Since the range from to V6 is the control range and the other ranges are the non-control range, if NO, the process proceeds to E (end). ST08R: If YES in ST07R, the range (V5 to V
Ratio of BKRV to 6) (right brake rate BKR%)
Is calculated. The calculation formula is: right brake rate BKR% = (BK
RV-V5) / (V6-V5). Circles A and B indicate that the next flow is continued.

FIG. 7 is a control flowchart following FIG. ST09L: Vmax shown in FIG. 3 (c), ST05
The following calculation is performed based on the ACC% determined in the above and the BKL% calculated in ST08L. TG1L = Vmax × A
CC% x (1-BKL%)

When the left brake opening BKLV is large, it is useless to apply a large power to the left motor, and it is desirable to save the power supplied to the left motor. When the left brake opening BKLV is large, ST
With 08L, BKL% becomes a large value closer to 1.0, and (1-BKL%) becomes a small value closer to 0. By multiplying (1−BKL%) by (Vmax × ACC%), it is possible to determine the corrected accelerator opening in consideration of the left brake opening.

As described above, it is useful to determine the voltage for controlling the left motor in consideration of the left brake opening. However, if the right brake opening is large, it is more desirable to further reduce the left motor control voltage. If the right brake opening is small, the effect on the left motor can be ignored. Thus, it is more desirable to determine the voltage for controlling the left motor in consideration of the left brake opening and the right brake opening.

Therefore, the BKL% of the last term of ST09L
Is replaced with (BKL% + p × BKR% × ACC%). BKR% is a value determined by ST08R. When considering the left motor, it is considered that the effect of the right brake becomes more significant as the accelerator opening ACC% is larger. Therefore, the right brake opening BKR% ACC
Multiply by%. Also, if BKR% is directly added to BKL%, the effect of the right brake opening BKR% becomes too strong, so that a coefficient p of about 0.3 to 0.5 is multiplied. Thus, the BKL% of the last term of ST09L is
It can be seen that it is appropriate to substitute (BKL% + p × BKR% × ACC%). This (BKL% + p × B
(KR% × ACC%) is referred to as a left corrected brake rate.

ST10L: TG which is a modified value of TG1L
2L is calculated by the following equation. TG2L = Vmax × ACC%
× {1- (BKL% + p × BKR% × ACC%)} ST09R and ST10R are ST09L and ST10L L
Is replaced with R and R is replaced with L, and the description is omitted. The circle C indicates that the flow will be continued next.

FIG. 8 is a control flowchart following FIG. ST11: Check whether the clutch is on. N
If O, that is, if the clutch is off, the snow removal operation is not performed, and the following control is unnecessary. ST12: If YES in ST11, the engine intake pressure g1 is read by the negative pressure sensor 48 in FIG. ST13: After t time, the engine intake pressure is read again. This is g2. The time t is a minute time. ST14: An intake pressure difference Δg (= g2-g1) of the engine is calculated.

FIG. 9 is a schematic diagram of the intake pressure to supplement FIG. 8. If the horizontal axis is time and the vertical axis is intake pressure, the cylinder and piston of the engine function as a reciprocating pump. It is assumed that the intake negative pressure drops to g1 by opening the valve and lowering the piston. If an excessive force acts on the crankshaft of the engine from the output side, the lowering speed of the piston decreases, the pumping operation weakens, and as a result, the intake negative pressure decreases only to g2 (g2> g1).
g2−g1 is defined as an intake pressure difference Δg.

What is important here is that when an excessive load acts on the engine, it first appears in the intake negative pressure.
This appears later in the engine speed or throttle valve opening. Therefore, if the intake negative pressure is monitored, good control of the responsiveness (response) can be performed.

FIG. 10 is a correction coefficient graph for supplementing FIG. 8, in which the horizontal axis represents the intake pressure difference Δg, and the vertical axis exceeds 0.
Indicates a correction coefficient β less than 0. When the intake pressure difference Δg shown on the horizontal axis is large, it is considered that the intake pressure has risen sharply due to heavy snow or snow lumps hitting the auger or blower. In this case, 0 (zero) is required to greatly reduce the speed of the snow blower. Gives a shift correction factor. Conversely, the intake pressure difference Δg shown on the horizontal axis
When is small, the load acting on the snow blower is relatively small, so it is only necessary to slightly lower the speed of the snow blower, and for that purpose, a correction coefficient close to 1.0 may be given.

Returning to FIG. 8, ST15: The correction coefficient β corresponding to Δg is determined with reference to 10 instead of β. ST16L: β is multiplied by TG2L obtained in ST10L. ST16R: β is multiplied by TG2R obtained in ST10R. ST17L: Since the left motor control value TG3L has been determined,
The left motor is driven by the TG 3L. ST17R: Since the right motor control value TG3R has been determined,
The right motor is driven by this TG3R.

The accelerator lever and the speed control lever described in the first aspect are not limited to levers in a narrow sense, and may be of any type and shape as long as they can change a manually set value, such as a dial switch or a slide switch. .

Further, in the embodiment, the electric traveling snow blower has been described as an example, but the electric traveling work machine according to the present invention may be a work vehicle such as a mower, a dozer, a cultivator, or the like.
The type is not particularly limited.

[0044]

According to the present invention, the following effects are exhibited by the above configuration. When a large load is applied to the work implement, the intake negative pressure of the engine rapidly increases. At this time, the outputs of the left and right electric motors are reduced to suppress the traveling speed. In general, an electric motor is directly controlled based on an accelerator opening. However, in the first aspect, for example, when controlling the left electric motor, the left motor control value is reduced when the left brake opening is large, and the left motor control value is taken into consideration when the right brake opening is large. Is further reduced. The same applies to the right electric motor. with this,
The driver can freely control the traveling direction.

As a result, the waste of rotating the electric motor at a high speed while applying the brake can be avoided. In addition, the vehicle may shake due to the imbalance between the left and right motors. For example, for the left electric motor, not only the left brake opening but also the right brake opening is taken into consideration. And speed adjustment work is facilitated irrespective of the condition of the running surface, and the smooth running performance of the vehicle is also improved.

If the working tool is a tilling claw, the working machine is a cultivator,
Similarly, if the working implement is a mowing blade, there are various types of working implements and working implements, such as lawn mowers. Among them,
In a snow blower, a work tool is composed of an auger and a blower, and the form of a load acting on the work tool is complicated. Therefore, in claim 2, by applying the present invention to a snow blower, it is possible to perform efficient snow removal while protecting the auger and blower while controlling the direction freely by controlling the left and right drive wheels. Can be.

[Brief description of the drawings]

FIG. 1 is a plan view of an electric traveling work machine according to the present invention.

FIG. 2 is a principle diagram of a clutch employed in the present invention.

FIG. 3 is an operation diagram of an accelerator lever employed in the present invention.

FIG. 4 is an operation diagram of a speed adjustment operation lever employed in the present invention.

FIG. 5 is a control system diagram of the electric traveling work machine according to the present invention.

FIG. 6 is a control flowchart of the electric traveling work machine according to the present invention.

FIG. 7 is a control flow diagram following FIG. 6;

FIG. 8 is a control flow diagram following FIG. 7;

FIG. 9 is a schematic diagram of intake pressure for supplementing FIG. 8;

FIG. 10 is a correction coefficient graph for supplementing FIG. 8;

[Explanation of symbols]

10: electric traveling work machine (snow plow), 13L: left electric motor, 13R: right electric motor, 15L: left drive wheel,
15R: Right drive wheel, 17L: Left brake, 17R ...
Right brake, 22 ... accelerator lever, 23L ... left speed adjustment operation lever, 23R ... right speed adjustment operation lever, 2
4 ... Control unit, 25 ... Throttle lever, 26 ... Accel potentiometer, 27L, 27R ... Brake potentiometer, 31 ... Engine, 32 ... Clutch, 34 ... Blower, 35 ... Auger, 48 ... Intake pressure sensor.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tsutomu Inui, 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Takahiro Yamamoto 1-4-1, Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (reference) 3D035 AA06 BA02 DA02 5H115 PA01 PC06 PG04 PG10 PI16 PI29 PU01 PV01 QI04 QI07 QN03 RB14 SE03 SE10 TO21 TO23 UI16 UI24

Claims (2)

[Claims] An engine for driving a work implement as a working system, comprising: a left and right electric motor for driving left and right driving wheels as a traveling system; and a left and right brake for respectively adjusting the speeds of the left and right driving wheels. In an electric traveling work machine having a clutch interposed in a power transmission path to a work implement, the positions of an accelerator lever operated by a driver and left and right speed adjustment operation levers are set by an accelerator opening, a left brake opening, a right In this control unit, the accelerator opening, the left brake opening, and the right brake opening are converted into an accelerator rate, a left brake rate, and a right brake rate, respectively. A left corrected brake rate is determined by taking into account the influence of the right brake rate on the left brake rate, and the accelerator rate is corrected with the left corrected brake rate. When the clutch is ON, a left motor control value is obtained by multiplying a correction coefficient of less than 1 determined according to a decrease in the intake negative pressure of the engine, and the influence of the left brake rate is added to the right brake rate. In this way, the right corrected brake rate is obtained, and the accelerator rate is corrected by the right corrected brake rate. When the clutch is on, a correction less than 1 determined according to a decrease in the intake negative pressure of the engine when the clutch is on. A traveling control method for an electric traveling work machine, wherein a right motor control value is obtained by multiplying a coefficient, and the right electric motor is controlled by the right motor control value. 2. The travel control method for an electric traveling work machine according to claim 1, wherein the work implement is an auger for bringing snow and a blower for blowing the snow, and the work implement is a snow blower.