KR102553645B1 - Engine performance controlling methods of work vehicle - Google Patents

Abstract

A method for controlling engine characteristics of a work vehicle is disclosed. In the method for controlling engine characteristics of a work vehicle according to the present invention, it is determined whether the current driving mode of the work vehicle is a driving mode or a working mode based on gear shift information provided by a detection means, and a control map set differently corresponding to the determined driving mode is generated. By controlling the output characteristics of the engine by using the engine, the optimum engine performance suitable for the situation (driving or work) can be displayed.

Description

Method for controlling engine characteristics of work vehicle {Engine performance controlling methods of work vehicle}

The present invention relates to a method for controlling engine characteristics of a work vehicle, and more particularly, to control the engine characteristics of a work vehicle to control engine output so that optimum engine performance can be exhibited according to vehicle driving conditions (work or driving conditions). It's about how.

If the governor (governor) that controls the fuel injection of a diesel engine is classified into fuel injection characteristic patterns, it can be divided into an all-speed governor that exerts a speed-governing function over all rotation ranges, and a set specific It can be classified as a half speed governor that performs a speed control function only in the rotation area.

The All speed governor exerts a speed control function within the entire rotation range from idle rotation to the highest rotation range, and the Half speed governor provides smooth idle operation and maximum rotation in the low speed range. In order not to exceed the speed, only the low-speed rotation area and the high-speed rotation area exhibit the speed control function, and the speed control function is not performed in the medium speed rotation area.

Agricultural work vehicles such as tractors require stable constant speed operation regardless of load fluctuations. Accordingly, in the case of conventional agricultural work vehicles, the former all speed governor is generally adopted, and the latter half speed governor is used for general vehicles requiring smooth acceleration and deceleration performance in response to the accelerator pedal operation. governor) is suitable.

Recently, in the case of agricultural work vehicles, there is a trend of improving work efficiency through stable constant speed operation as well as speeding up to satisfy mobility. That is, there is a trend to improve engine output characteristics so that it can sufficiently cope with not only work on the field but also high-speed transport work on the road.

However, as described above, since the governor mounted on the conventional agricultural work vehicle adopts an all-speed governor suitable for the main work, the pavement work, there is an advantage that the range of revolutions (RPM) fluctuation is small even when the load changes, but in general road driving There is a disadvantage in that the driving quality is poor due to poor acceleration or deceleration, and the shifting load applied to the transmission is large, resulting in poor ride quality.

Japanese Patent Laid-Open No. 2007-040301 (published on February 15, 2007)

The technical problem to be solved by the present invention is to determine whether the driving mode intended by the driver is a working mode on the pavement or a general driving mode on the road from the shift operation state, and depending on the determination result, the characteristics of the different types of governors suitable for the corresponding driving mode An object of the present invention is to provide a method for controlling engine characteristics of a working vehicle to control engine output so that optimum engine performance can be exhibited in a corresponding driving mode (driving mode or working mode) using a (control map).

According to an embodiment of the present invention as a means of solving the problem,

(a) a driving mode determination step of determining whether the current driving mode of the work vehicle is a driving mode or a working mode from the shift information provided by the detection means; and

(b) an engine output control step of controlling the output characteristics of the engine using a control map set differently corresponding to the driving mode determined through the operation mode determination step;

In the driving mode determination step of the present invention, a sub-shift sensor for detecting the manipulation position of the sub-shift lever and transmitting the detected manipulation position information to the control unit or an electric signal corresponding to the number of manipulations according to sub-shift manipulation is turned on/off. The driving mode may be determined from sub-shift information provided by at least one detecting means among a sub-shift switch output as , and a shift control unit (TCU) for sub-shift control.

In addition, when the operation mode is determined to be the work mode, in the engine output control step, the engine speed (Actual RPM) is set to a preset target RPM in response to the accelerator pedal operation position, regardless of the size of the load. It is possible to control engine output characteristics so as to be maintained.

In addition, the present invention may further include a step of determining the number of gear shifts from the operation state of the peripheral transmission when the driving mode is determined as a result of the determination of the driving mode, and at this time, different governor characteristics ( control map) can be used to control engine output characteristics.

Preferably, when the shift stage identified through the step of determining the number of shift stages is a low speed range (when the peripheral transmission gear ratio is low), the engine output is obtained by using a control map having a torque curve having a small torque fluctuation rate with respect to a change in engine speed. The engine output characteristics may be controlled by using a control map having a torque curve having a large torque variation rate with respect to engine speed variation in the middle speed range (middle gear ratio) and high speed range (high gear ratio).

In addition, in the control of engine output characteristics at the high speed stage, when the vehicle speed reaches a preset maximum speed, control for limiting the engine speed so that the engine speed does not increase any more may be executed through the control unit.

According to the method for controlling engine characteristics of a work vehicle according to an embodiment of the present invention, a driving mode intended by a driver is determined from the operation state of a shift operating mechanism, and a heterogeneous control map (governor characteristic) suitable for the corresponding driving mode is determined according to the determination result. ) to control the engine output, optimal engine performance can be exhibited according to the driving mode (driving mode or work mode).

Specifically, in the work mode, regardless of the size of the load, the engine speed (Actual RPM) is maintained at the preset target RPM according to the accelerator pedal operation position by using the All speed governor characteristics. By controlling the engine output, it is possible to prevent a decrease in the number of revolutions depending on the load, thereby preventing engine stall and ensuring uniformity of work quality.

In addition, in the driving mode for general road driving, the engine output characteristics are controlled using a control map having a torque curve (half speed governor characteristic) having different torque fluctuation rates for changes in engine revolutions according to the number of shift stages, thereby reducing shift shock and Accordingly, it is possible to solve the deterioration in riding comfort, and the problem of deterioration in durability due to a large load applied to the transmission according to high load and low output can also be surely solved.

1 is an exemplary side view of a farm tractor to which an engine characteristic control method according to an embodiment of the present invention is applied.
2 is a schematic configuration diagram of a governor (governor) that controls fuel injection;
3 is a diagram illustrating a method for controlling engine characteristics of a working vehicle according to the present invention;

Hereinafter, preferred embodiments of the present invention will be described in detail.

Terms used in the specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features or It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Also, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

In addition, terms such as "...unit", "...unit", and "...module" described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. can

In the description with reference to the accompanying drawings, the same reference numerals will be given to the same components, and overlapping descriptions thereof will be omitted. In addition, in the description of the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

Hereinafter, a case in which the method for controlling engine characteristics of a work vehicle according to the present invention is applied to a farm tractor will be described as an example.

1 is an exemplary side view of a farm tractor to which an engine characteristics control method according to an embodiment of the present invention is applied, and FIG. 2 is a schematic configuration diagram of a governor (governor) for controlling fuel injection.

1 to 2, the power output from the diesel engine 2 mounted on the tractor body 1 is transmitted to the transmission 4 through the clutch housing 3, and the transmission 4 properly After shifting, it is transmitted as driving power to the rear wheels 5 or the front and rear wheels 6 and 5, and at the same time, it is transmitted as working power to the rear PTO shaft 7 through a PTO transmission system independent of the driving transmission system.

At the rear of the vehicle body, a rear work machine, for example, a rotary tiller, is movably connected through a hydraulic lift arm (8) and a three-point link structure (9), and the power drive shaft of the rear work machine is connected to the PTO shaft (7). By being connected so as to transmit power, it is driven by the power output from the PTO shaft 7 to perform a predetermined work that meets the purpose of the work machine.

A control rack 12 corresponding to a fuel injection control mechanism of a fuel injection pump (injection pump 11) mounted in the engine 2 is controlled by an electronic governor (governor). The control rack 12 is connected to the solenoid 13 whose displacement amount varies in proportion to the input current, and at this time, the position of the control rack 12 can be detected by the stroke sensor 14 using a differential transformer (see FIG. 2 ).

The actual engine speed (Actual RPM) can be detected through the sensor 17 installed adjacent to the side of the gear 16 coupled to the end of the camshaft 15 for pump driving, and the sensor 14, 17 The position of the control rack 12 is feedback-controlled by comparing the detected information with a target RPM, which is artificially set according to the driver's operation of the speed control mechanism (accelerator pedal or hand accelerator).

The electronic governor is controlled by the control unit 18 into which a predetermined control map is set and input. Specifically, the control unit 18 determines the fuel injection control value (current amount for solenoid operation) from the rotation speed setting value (Target RPM) set by the speed control mechanism, and output, and as the solenoid 13 is driven with the determined control value, fuel injection suitable for the set number of revolutions is performed.

While fuel injection corresponding to the set number of revolutions is being performed, the control unit 18 frequently recognizes the actual RPM of the engine from the information detected and provided by the sensor 17. In addition, the position of the control rack 12 is determined by comparing the actual RPM determined from the information of the sensor 17 with the target RPM and outputting the control compensation value to the solenoid 13 as a current signal. feedback control.

As the speed control mechanism, a hand accelerator lever 19 that can be frictionally fixed to an arbitrary manipulation position desired by a driver and an accelerator pedal 20 that automatically returns to an idle side after an arbitrary manipulation can be used. In addition, a detection unit, for example, a potentiometer 21 or 22 may be installed in each speed control mechanism to output the displacement according to the driver's physical manipulation as an electrical signal and transmit it to the control unit 18 .

In the control circuit of the control unit 18, a different type of control map (governor characteristic) for controlling the electronic governor is set. According to the method for controlling engine characteristics of a work vehicle according to an embodiment of the present invention, heterogeneous control maps (governor characteristics) for controlling an electronic governor can be largely classified into two types.

One is a control map for work mode (All speed governor) that uses a mapped torque curve so that the engine speed is maintained at the set speed set by the speed control mechanism regardless of the size of the load, and the other is a control map for engine speed change. It is a control map (Half speed governor) for driving mode using a torque curve with a different torque variation rate for

The heterogeneous control map (governor characteristic) preset in the control unit 18 is a driving mode determination result (from the shift operation state operated by the driver, whether the driver's intended driving mode is the work mode on the pavement or not on the road), which will be described later. It can be automatically selected according to the normal driving mode), and the engine output control is performed according to the engine output control set by the selected control map.

3 is a diagram illustrating a method for controlling engine characteristics of a work vehicle according to the present invention. With reference to this, a method for controlling engine characteristics of the work vehicle according to an embodiment of the present invention will be described.

Referring to FIG. 3 , in the engine characteristic control according to the present invention, first, from the shift information provided by detection means installed in each part of the vehicle, the driver's intention is determined according to the driving mode of the current work vehicle, for example, a tractor, that is, the driver's artificial shift operation. It is determined whether the driving mode to be operated is a driving mode for general road driving or a working mode for working on pavement (driving mode determination step, S100).

Preferably, a sub-shift sensor that detects the manipulation position of the sub-shift lever according to the artificial sub-shift operation and transmits the detected manipulation position information to the control unit or an electric signal corresponding to the number of manipulations according to the sub-shift manipulation is turned on/off. The driving mode may be determined from sub-shift information provided by at least one detecting means among the sub-shift switch outputting , and the shift control unit (TCU) for sub-shift control.

For example, if the sub-shift lever (or sub-shift switch) is operated in the low speed range producing high-torque and low-speed output, it is regarded as a shift operation for packaging work and the control unit determines it as a work mode, and the sub-shift lever (or sub-shift switch) ) is operated in the middle and high speed stages suitable for on-road driving requiring low torque and high-speed output, it is regarded as shifting for road driving and determined as a driving mode.

After grasping the driver's intended driving mode of the vehicle from the subshift information according to the driver's intended subshift manipulation, a control map (governor characteristic) set differently in response to each determined driving mode, that is, driving mode or working mode, is generated. A process of selecting and controlling engine characteristics using the selected control map is performed so that the output performance of the engine suitable for the corresponding driving mode can be exhibited (engine output control step, S200).

Here, the control map (governor characteristic) set differently according to the driving mode may be automatically selected by the control unit that recognizes the shift operation state according to the driver's intended shift operation. Hereinafter, engine output control for each mode by heterogeneous control maps (governor characteristics) will be examined in more detail.

When it is determined that the driving mode of the vehicle, determined from the sub-transmission operation state, is a working mode suitable for packaging work, in step S200, the engine speed corresponds to the operation of the accelerator pedal (or hand accelerator) regardless of the size of the load applied to the vehicle. to select the mapped control map (governor characteristic) to be maintained at the preset target RPM.

That is, when the subshift lever (or subshift switch) is operated in the low speed range where high torque and low speed output is required, the control unit determines that the subshift operation is intended to produce output suitable for packaging work. Regardless of the size of the load applied to the engine, select the mapped first control map (A) so that the engine speed is maintained at the set speed, and control the output characteristics of the engine using the torque curve set in the first control map (A). do.

For example, when the accelerator pedal (or hand accelerator) is operated at a position where 2000 RPM is output, 2000 RPM is set as the target RPM, and fuel injection is performed to raise the engine speed to the target RPM. When the actual RPM is lower than the target RPM due to the load acting on the shape, compensation control is performed to bring the actual RPM closer to the target RPM.

In the torque curve of the control map, the relationship between the engine speed and torque (position of the control rack) corresponding to the accelerator pedal (or hand accelerator) operation position is preset as map data. Therefore, in work mode, the accelerator pedal (or hand accelerator) Excel) PID control of the solenoid so that the position of the control rack is directed toward the target rack position based on the map data corresponding to the target rotation speed set by operation, so that the engine speed is maintained at the set speed regardless of the load.

When it is determined that the driving mode of the vehicle determined from the operation state of the auxiliary transmission is a driving mode suitable for on-road driving, a step of determining the number of gear shifts, specifically, the number of gears from the operation state of the main gearbox, is additionally passed through Determine the number of gear shifts of the peripheral gearbox. In addition, the engine output characteristics are controlled using a control map (governor characteristic) set differently according to the identified number of shift stages.

That is, when the subshift lever (or subshift switch) is operated on the high-speed side where low torque and high-speed output is required, the control unit determines that the current subshift operating state is a shift intended to produce an output suitable for road driving. , In addition, from the operating state of the peripheral transmission, the driver's intended number of main gears is determined, and the engine output is controlled using a control map mapped differently according to the identified number of main gears.

When it is determined that the driving mode is determined as the driving mode, in engine output control, three types of differently set control maps may be used according to the number of main speed stages set by the driver's manipulation of the main speed. Preferably, a second control map (B) selected when the main gear is operated to the low-speed side, and a third control map (C) selected when the main gear is operated to the middle-speed or high-speed side, and 4 control maps (D) can be used.

In determining the shift operation state of the main transmission, the main gear sensor detects the operating position of the main gear lever and transmits the detected operating position information to the control unit, or the electric signal corresponding to the number of operating stages is turned on/off according to the operation of the main gear. The operating state of the main gearbox can be grasped from the main speed information provided by at least one detecting means among the main gear switch output as , and the shift control unit (TCU) for controlling the main gear.

A torque curve may be set in the second control map B, which is selected when it is determined as the driving mode and the main gear is operated to the low speed side, so that the torque fluctuation rate has a relatively small value with respect to the engine speed fluctuation. That is, when the number of shift stages of the main transmission gear is low (when the main transmission gear ratio is low), the engine output characteristics are controlled by using a control map having a torque curve having a small torque fluctuation rate with respect to engine speed fluctuation.

In step S200, torque curves may be set in the third and fourth control maps C and D, which are selected when the main gear ratio is equal to or higher than the medium speed, so that the torque fluctuation rate has a relatively large value compared to the engine rotation speed fluctuation. That is, when the number of shift stages of the main gear is equal to or higher than the middle gear (when the gear ratio of the main gear shift is equal to or higher than the middle), the engine output characteristics are controlled using a control map having a torque curve having a large torque change rate with respect to engine speed change.

Preferably, when the main transmission is operated in the middle speed range (intermediate gear ratio), a third control map set to a torque curve having a large torque variation rate compared to engine rotation speed variation according to operation of the accelerator pedal (or hand accelerator) may be selected, , When the main transmission is operated at a high speed (high gear ratio), a fourth control map set as a torque curve may be selected so that torque changes when the accelerator pedal (or hand accelerator) is operated.

Meanwhile, in the fourth control map selected when the main gearbox is set to the high speed range, a predetermined engine speed increase limiting region for limiting the maximum speed of the vehicle may be set. That is, in the engine output characteristic control through the fourth control map, engine speed limiting control may be performed so that the engine speed does not increase any more when the vehicle speed reaches the set maximum speed.

According to the method for controlling the engine characteristics of a work vehicle according to the embodiment of the present invention described above, the driving mode intended by the driver is determined from the operating state of the shifting mechanism, and a heterogeneous control map suitable for the corresponding driving mode is determined according to the determination result. By controlling engine output using (governor characteristics), optimum engine performance can be exhibited according to the driving mode (driving mode or work mode).

Specifically, in the work mode, regardless of the size of the load, the engine speed (Actual RPM) is maintained at the preset target RPM according to the accelerator pedal operation position by using the All speed governor characteristics. By controlling the engine output, it is possible to prevent a decrease in the number of revolutions depending on the load, thereby preventing engine stall and ensuring uniformity of work quality.

In addition, in the driving mode for general road driving, the engine output characteristics are controlled using a control map having a torque curve (half speed governor characteristic) having different torque fluctuation rates for changes in engine revolutions according to the number of shift stages, thereby reducing shift shock and Accordingly, it is possible to solve the deterioration in riding comfort, and the problem of deterioration in durability due to a large load applied to the transmission according to high load and low output can also be surely solved.

As described above, according to the method for controlling engine characteristics of a working vehicle according to an embodiment of the present invention, the driving mode intended by the driver is determined from the operating state of the shifting mechanism, and a different type of governor suitable for the corresponding driving mode is determined according to the determination result. By controlling the engine output using the characteristic (control map), optimum engine performance can be exhibited according to the driving mode (driving mode or working mode).

Specifically, in the work mode, regardless of the size of the load, the engine speed (Actual RPM) is maintained at the preset target RPM according to the accelerator pedal operation position by using the All speed governor characteristics. By controlling the engine output, it is possible to prevent a decrease in the number of revolutions depending on the load, thereby preventing engine stall and ensuring uniformity of work quality.

In addition, in the driving mode for general road driving, the engine output characteristics are controlled using a control map having a torque curve (half speed governor characteristic) having different torque fluctuation rates for changes in engine revolutions according to the number of shift stages, thereby reducing shift shock and Accordingly, it is possible to solve the deterioration in riding comfort, and the problem of deterioration in durability due to a large load applied to the transmission according to high load and low output can also be surely solved.

In the above detailed description of the present invention, it has been described that the speed torque map is adjusted when the electronic governor is applied as a preferred example, but the present invention is not limited to the case where the electronic governor is applied. Since it is also applicable to an electronically controlled fuel injection system, for example, a CRDI (Common Rail Direct Injection) engine, it should be noted that this may also be included in the scope of the present invention.

In addition, in the above, only special embodiments according to the present invention have been described. However, it should be understood that the present invention is not limited to the particular forms mentioned in the detailed description, but rather it is understood to include all modifications, equivalents and substitutes within the spirit and scope of the present invention as defined by the appended claims. It should be.

1: tractor body 2: diesel engine
3: clutch housing 4: transmission
5: rear wheel 6: front wheel
7: PTO shaft 8: hydraulic lifting arm
9: three-point link 11: fuel injection pump (injection pump)
12: control rack 13: solenoid
14: stroke sensor 15: camshaft for pump drive
16: gear 17: sensor
18: control unit 19: hand accelerator lever
20: foot accelerator pedal 21, 22: potentiometer

Claims (6)

(a) a driving mode determination step of determining whether the current driving mode of the work vehicle is a driving mode or a working mode from the shift information provided by the detection means; and
(b) an engine output control step of controlling the output characteristics of the engine using a control map set differently corresponding to the driving mode determined through the operation mode determination step; and
As a result of determining the driving mode through the step (a), if the driving mode of the current work vehicle is the driving mode, the number of gear shifts is first determined from the operating state of the peripheral transmission,
Thereafter, in the step (b), the engine output characteristics are controlled using a different control map according to the identified number of gear shifts of the peripheral transmission,
When the identified number of shift stages of the peripheral transmission is in the low speed range, engine output characteristics are controlled using a control map having a torque curve having a small torque fluctuation rate with respect to changes in engine speed,
A method for controlling engine characteristics of a work vehicle, characterized in that, in the middle and high speed stages, engine output characteristics are controlled using a control map having a torque curve having a large torque fluctuation rate with respect to engine rotation speed fluctuation.
According to claim 1,
In the driving mode determination step,
A sub-shift sensor that detects the operation position of the sub-shift lever and transmits the detected operation position information to the control unit, or a sub-shift switch that outputs an electric signal corresponding to the operating stage in an on/off form according to the sub-shift operation, and a sub-shift control A method for controlling engine characteristics of a work vehicle, characterized in that the driving mode is determined from sub-shift information provided by at least one detection means among shift control units (TCUs) for the vehicle.
According to claim 1,
When the driving mode is determined to be the working mode, in the engine output control step, the engine speed is maintained at the preset target RPM according to the accelerator pedal operating position regardless of the size of the load. A method for controlling engine characteristics of a work vehicle, characterized in that for controlling output characteristics.
delete delete According to claim 1,
In the engine output characteristics control at the high speed stage, the engine characteristic control method of the work vehicle, characterized in that the control of limiting the engine speed so that the engine speed does not increase any more when the set maximum speed is reached.

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