KR20140060952A - Transmission control system for working vehicle and method thereof - Google Patents

Transmission control system for working vehicle and method thereof Download PDF

Info

Publication number
KR20140060952A
KR20140060952A KR1020120127945A KR20120127945A KR20140060952A KR 20140060952 A KR20140060952 A KR 20140060952A KR 1020120127945 A KR1020120127945 A KR 1020120127945A KR 20120127945 A KR20120127945 A KR 20120127945A KR 20140060952 A KR20140060952 A KR 20140060952A
Authority
KR
South Korea
Prior art keywords
engine
rpm
load
continuously variable
variable transmission
Prior art date
Application number
KR1020120127945A
Other languages
Korean (ko)
Inventor
정상철
Original Assignee
엘에스엠트론 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 엘에스엠트론 주식회사 filed Critical 엘에스엠트론 주식회사
Priority to KR1020120127945A priority Critical patent/KR20140060952A/en
Publication of KR20140060952A publication Critical patent/KR20140060952A/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H59/00—Control inputs to control units of change-speed-, or reversing-gearings for conveying rotary motion
    • F16H59/14—Inputs being a function of torque or torque demand
    • F16H59/24—Inputs being a function of torque or torque demand dependent on the throttle opening
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/02—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used
    • F16H61/0202—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used the signals being electric
    • F16H61/0204—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used the signals being electric for gearshift control, e.g. control functions for performing shifting or generation of shift signal

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Transmission Device (AREA)

Abstract

A shift control system and method for a work vehicle is disclosed.
The transmission control system is connected to the continuously variable transmission and the continuously variable transmission, which are configured to obtain a continuous reduction ratio from the rotation of the engine, including the HST and the planetary gears. The transmission control system controls the throttle opening amount, engine RPM, RPM of the HST output shaft, A target operating condition setting unit for setting a target vehicle speed according to a driver operation, and a shift control unit for controlling the continuously variable transmission. The transmission control unit sets the gear ratio of the continuously variable transmission on the basis of the target vehicle speed, the engine RPM and the load amount, receives the output of the sensors coupled to the continuously variable transmission as a feedback input to grasp the current vehicle condition, .
This enables a simple and inexpensive shift control, which can only affect the local functions related to the shift, without the need to utilize the mechanical engine as it is in the working vehicle and to optimize the comprehensive function for the entire engine.

Figure P1020120127945

Description

[0001] The present invention relates to a shift control system for a working vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control system and method for a work vehicle, and more particularly, to a shift control system and a method for a work vehicle having a continuously variable transmission and a mechanical engine.

BACKGROUND ART [0002] As a power transmission system for a working vehicle such as a tractor, an automatic transmission system using a continuously variable transmission in combination of a HST (Hydrostatic Transmission) and a planetary gear is used.

In order to apply such an automatic transmission system, there is a need for an electronic engine system equipped with an ECU (Electronic Control Unit) that detects the load of the working vehicle and adjusts the characteristics of the engine as a whole to a conventional mechanical engine.

For example, Korean Patent Publication No. 10-2012-0081376 exemplifies an electronic engine system having a control unit (ECU). Here, the control unit (ECU) includes a function to precisely control the core functions of the engine such as fuel injection, idling, and limit value setting, and provides comprehensive control over all parts related to driving and running of the working vehicle such as the braking system and the steering system do.

However, the electronic engine system capable of directly and entirely controlling the engine of the working vehicle has a problem of high cost, high cost, and difficulty in applying the engine because of its complexity.

Accordingly, there is a need for a simple and inexpensive shift control method that can utilize the mechanical engine as it is in a work vehicle, and can only affect local functions related to the shift without having to optimize comprehensive functions for the entire engine.

Korean Patent Publication No. 10-2012-0081376 discloses an example of an electronic engine system having a control unit (ECU)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the conventional art as described above, and it is an object of the present invention to provide a shift control device and a shift control method, The present invention provides a shift control system and method for a work vehicle in a simple and inexpensive manner.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. There will be.

A shift control system for a work vehicle according to the present invention includes an engine; A continuously variable transmission including a hydrostatic transmission (HST) and a planetary gear so as to obtain a continuous reduction ratio from the rotation of the engine; A throttle opening sensor for sensing an amount of throttle opening of the engine; An engine RPM sensing sensor for sensing an engine revolution minute (RPM) transmitted from the engine to an input end of the continuously variable transmission; An output RPM sensing sensor for sensing the RPM of the HST output shaft located in the continuously variable transmission; A vehicle speed sensing sensor for detecting an RPM of a drive shaft passing through the planetary gear at the output end of the continuously variable transmission and converting the RPM into an actual vehicle speed; A load calculating section for calculating a load amount based on the throttle opening amount and the engine RPM; A target condition setting unit for setting a target vehicle speed in accordance with a driver operation; And setting the speed ratio of the continuously variable transmission on the basis of the target vehicle speed, the engine RPM, and the load, wherein the output of the engine RPM sensing sensor, the output RPM sensing sensor and the vehicle speed sensing sensor is received as a feedback input, And a speed change control unit for adjusting the speed change stage of the CVT according to the vehicle conditions.

The load operation unit may receive the throttle opening amount and the engine RPM, calculate a no-load engine RPM from the throttle opening amount, and calculate the load amount based on the no-load engine RPM and the engine RPM.

The target condition setting unit may set the target vehicle speed on the basis of the throttle opening amount, the direction lever, and the operation value of the speed lever.

Wherein the speed change control section sets the speed ratio of the continuously-variable transmission on the basis of the target vehicle speed, the engine RPM and the load amount, and performs feedback control of the continuously-variable transmission so that the actual vehicle speed reaches the target vehicle speed, If the load is greater than or equal to the maximum allowable value, the shift stage is shifted down. If the load is less than the maximum allowable value, the shift stage is maintained and the torque of the engine required by the vehicle can be variably transmitted.

Meanwhile, a shift control method of a working vehicle according to the present invention includes: sensing an amount of throttle opening of an engine; Obtaining a no-load engine RPM based on the throttle opening amount; Sensing engine RPM; Setting a speed change stage based on the target vehicle speed and the sensed engine RPM; Calculating a load based on the sensed engine RPM and the no-load engine RPM; Shifting down the shift stage when the calculated load is greater than or equal to the maximum allowable value and feeding back to the throttle opening amount sensing step of the engine; And maintaining the shift stage if the calculated load is less than a maximum allowable value.

According to the shift control system and method of the working vehicle according to the present invention, it is possible to utilize the mechanical engine as it is in the working vehicle, and to influence only the local function related to the shift without needing to optimize the comprehensive function for the entire engine , It is possible to realize a simple and inexpensive shift control.

Brief Description of Drawings FIG. 1 is a block diagram of a shift control system for a working vehicle according to an embodiment of the present invention; FIG.
2 is a flowchart illustrating a shift control method of a working vehicle according to an embodiment of the present invention.

Hereinafter, a shift control system and method of a work vehicle according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a shift control system for a work vehicle according to an embodiment of the present invention.

1, a shift control system for a work vehicle according to an embodiment of the present invention includes an engine 110, a continuously variable transmission 120, a throttle opening sensor 130, an engine RPM detection sensor 141, A sensor 142, a vehicle speed sensor 143, a load calculation unit 210, a target condition setting unit 220, and a shift control unit 230.

The engine 110 uses the petroleum fuel as an energy source to generate a torque (rotational force) and transmits it to the continuously variable transmission 120.

The CVT 120 decelerates or accelerates the output from the engine 110 to produce torque and revolution per minute (RPM) suitable for the vehicle conditions. The CVT 120 includes a hydrostatic transmission 121 and a planetary gear 122 So as to obtain a continuous reduction ratio from the rotation of the engine 110.

The traveling direction of the vehicle and the engine RPM can be changed by the HST 121 and the planetary gear 122 constituting the continuously variable transmission 120. [

The throttle opening sensor 130 senses the amount of throttle opening of the engine 110.

The engine RPM sensing sensor 141 senses the engine RPM transmitted from the engine 110 to the input of the continuously variable transmission 120. [

The output RPM sensing sensor 142 senses the RPM of the output shaft of the HST 121 located in the continuously variable transmission 120.

The vehicle speed sensor 143 detects the RPM of the drive shaft via the planetary gear 122 and converts it into a vehicle speed to measure an actual vehicle speed of the vehicle.

The load computing unit 210 computes a load using the throttle opening amount detected by the throttle opening sensor 130 and the engine RPM sensed by the engine RPM sensing sensor 141.

In one embodiment, the load computing section 210 receives the throttle opening amount and the engine RPM sensed from the throttle opening sensor 130 and the engine RPM sensing sensor 141, respectively, calculates the no-load engine RPM from the throttle opening amount, The calculated load amount applied to the engine 110 can be calculated by comparing the calculated no-load engine RPM with the sensed engine RPM.

The target condition setting unit 220 sets the target vehicle speed according to the driver's operation and transmits the target vehicle speed to the shift control unit 230.

In one embodiment, the target condition setting unit 220 detects the throttle opening amount, the manipulated values of the direction lever 150 and the speed lever 160, and sets the target vehicle speed and the traveling direction of the vehicle based on these signals . At this time, the driver can adjust the amount of throttle opening of the engine 110 using a mechanical link of a throttle lever or a pedal (not shown). The direction lever 150 is a mechanism that the driver operates to determine whether the vehicle is moving forward or backward. The speed lever 160 is a mechanism that the driver operates to determine the vehicle speed.

The transmission control unit 230 receives the feedback signals from the load calculation unit 210, the target condition setting unit 220, and the CVT 120, and controls the CVT 120.

More specifically, the shift control unit 230 determines the load amount of the vehicle calculated by the load calculation unit 210, the target vehicle speed set by the target condition setting unit 220 according to the intention of the driver, the engine RPM The speed change stage of the continuously variable transmission 120 is set. The transmission control unit 230 receives the output of the engine RPM sensing sensor 141, the output RPM sensing sensor 142 and the vehicle speed sensor 143 as feedback inputs to grasp the current vehicle condition, The speed ratio of the continuously variable transmission 120 is controlled to change the speed ratio so that the necessary torque is secured.

In one embodiment, the shift control unit 230 sets the speed change stage of the continuously variable transmission 120 on the basis of the target vehicle speed, the engine RPM and the load, and when the actual vehicle speed sensed through the vehicle speed sensor 143 reaches the target vehicle speed The continuously variable transmission 120 can be feedback-controlled. In the feedback control, the shift control unit 230 shifts down the gear ratio of the predetermined continuously variable transmission 120 when the load calculated by the load calculation unit 210 is equal to or greater than the maximum allowable value, and when the load amount is less than the maximum allowable value, So that the torque of the engine required by the vehicle can be variably transmitted.

2 is a flowchart illustrating a shift control method of a working vehicle according to an embodiment of the present invention.

The driver first sets the target vehicle speed and the traveling direction of the vehicle with the speed lever 160 and the direction lever 150. [ Next, when the driver opens the throttle valve of the engine 110 using the throttle lever or the pedal (not shown), the engine RPM rises and the vehicle moves while the reduction ratio of the continuously variable transmission 120 changes.

When the load acts on the vehicle over a certain level during the movement of the vehicle, the transmission control unit 230 controls the speed change stage to change the reduction ratio of the continuously variable transmission 120 to secure the required torque. The value of the speed change ratio that determines the reduction ratio can be adjusted according to the vehicle conditions including the vehicle speed and the load.

The load applied to the vehicle is calculated by the load calculating unit 210. [ In one embodiment, the load computing section 210 has a vehicle load map according to the throttle opening amount and the engine RPM. The throttle opening amount can be confirmed by the throttle opening degree sensor 130 mounted on the engine 110 and the engine RPM is checked by the engine RPM detection sensor 141 provided between the engine 110 and the input end of the CVT 120 . The load calculating unit 210 receives the outputs of the throttle opening sensor 130 and the engine RPM sensing sensor 141, extracts the load amount from the stored vehicle load map, and transmits the load amount to the shift control unit 230.

Referring to FIG. 2, the throttle opening sensor 130 senses the amount of throttle opening of the engine 110 and transmits it to the shift control unit 230 (S110).

The load computing unit 210 calculates the no-load engine RPM (E 1 ) based on the throttle opening amount detected from the throttle opening sensor 130 (S120).

Engine RPM detection sensor 141 detects the engine RPM (E 2) delivered to the input end of the continuously variable transmission 120 from the engine (110) (S130).

The shift control section 230 sets the speed change stages of the continuously variable transmission 120 on the basis of the target condition setting unit engine RPM (E 2) A (220) is detected on a target vehicle speed and S130 set according to the driver's operation (S140) . At this time, the transmission control unit 230 can continuously change the reduction ratio of the CVT 120 within a certain range (for example, 0 to MAX value) by setting the speed change stage of the CVT 120. [

Thereafter, the load computing unit 210 compares the engine RPM sensed at S130 with the no-load engine RPM calculated at S120, and calculates a load applied to the vehicle to provide the computed load to the shift control unit 230 (S150).

If the load of the vehicle calculated in S150 is equal to or greater than the maximum allowable value (S160), the transmission control unit 230 shifts down the predetermined number of shift stages to increase the reduction ratio of the continuously variable transmission 120, (S170). Then, the transmission control unit 230 feeds back to S110 to again detect the amount of throttle opening of the engine 110, and repeats the steps of S110 to S180.

If the load of the vehicle calculated in S150 is less than the maximum permissible value (S160), the transmission control unit 230 determines that the torque corresponding to the load of the vehicle is secured and continuously maintains the predetermined number of shift stages (S180).

Thus, the transmission control section 230 determines the load applied to the vehicle from the output of the load calculation section 210, the engine RPM detection sensor 141, the output RPM detection sensor 142 and the vehicle speed sensor 143, And the speed reduction ratio of the CVT 120 to control the speed ratio of the CVT 120 according to current vehicle conditions.

The configuration of the shift control system and the method of the working vehicle according to the present invention is not limited to the above-described embodiments, and can be variously modified and carried out within the scope of the technical idea of the present invention.

110: engine, 120: continuously variable transmission,
121: HST, 122: planetary gear,
130: Throttle opening sensor, 141: Engine RPM detection sensor,
142: output RPM detection sensor, 143: vehicle speed detection sensor,
210: load calculation unit, 220: target condition setting unit,
230:

Claims (5)

engine;
A continuously variable transmission including a hydrostatic transmission (HST) and a planetary gear so as to obtain a continuous reduction ratio from the rotation of the engine;
A throttle opening sensor for sensing an amount of throttle opening of the engine;
An engine RPM sensing sensor for sensing an engine revolution minute (RPM) transmitted from the engine to an input end of the continuously variable transmission;
An output RPM sensing sensor for sensing the RPM of the HST output shaft located in the continuously variable transmission;
A vehicle speed sensing sensor for detecting an RPM of a drive shaft passing through the planetary gear at the output end of the continuously variable transmission and converting the RPM into an actual vehicle speed;
A load calculating section for calculating a load amount based on the throttle opening amount and the engine RPM;
A target condition setting unit for setting a target vehicle speed in accordance with a driver operation; And
The output RPM detection sensor, and the vehicle speed detection sensor as feedback inputs to set the vehicle condition based on the target vehicle speed, the engine RPM, and the load amount, And a shift control unit for controlling the speed change stage of the continuously variable transmission in accordance with the vehicle condition.
2. The apparatus according to claim 1,
The throttle opening amount, the throttle opening amount and the engine RPM, calculates a no-load engine RPM from the throttle opening amount, and calculates the load amount based on the no-load engine RPM and the engine RPM. .
The apparatus according to claim 1,
Wherein the target vehicle speed is set based on the throttle opening amount, the direction lever, and the operation value of the speed lever.
The transmission control device according to claim 1,
Wherein the control unit sets the number of gears of the continuously variable transmission on the basis of the target vehicle speed, the engine RPM and the load amount, feedback controls the continuously variable transmission so that the actual vehicle speed reaches the target vehicle speed, Or more, and when the load amount is less than the maximum permissible value, the shift speed is maintained, and the torque of the engine required by the vehicle is variably transmitted.
Sensing an amount of throttle opening of the engine;
Obtaining a no-load engine RPM based on the throttle opening amount;
Sensing engine RPM;
Setting a speed change stage based on the target vehicle speed and the sensed engine RPM;
Calculating a load based on the sensed engine RPM and the no-load engine RPM;
Shifting down the shift stage when the calculated load is greater than or equal to the maximum allowable value and feeding back to the throttle opening amount sensing step of the engine; And
And if the calculated load amount is less than the maximum permissible value, maintaining the speed change stage.
KR1020120127945A 2012-11-13 2012-11-13 Transmission control system for working vehicle and method thereof KR20140060952A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020120127945A KR20140060952A (en) 2012-11-13 2012-11-13 Transmission control system for working vehicle and method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020120127945A KR20140060952A (en) 2012-11-13 2012-11-13 Transmission control system for working vehicle and method thereof

Publications (1)

Publication Number Publication Date
KR20140060952A true KR20140060952A (en) 2014-05-21

Family

ID=50890124

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020120127945A KR20140060952A (en) 2012-11-13 2012-11-13 Transmission control system for working vehicle and method thereof

Country Status (1)

Country Link
KR (1) KR20140060952A (en)

Similar Documents

Publication Publication Date Title
US8935068B2 (en) System and method for optimizing downshifting of a transmission during vehicle deceleration
US8798877B2 (en) Control device of continuously variable transmission for vehicle
US8271167B2 (en) Shift control apparatus for vehicular continuously variable transmissions
US7578766B2 (en) Apparatus and method for controlling automatic transmission
US7806791B2 (en) Continuously variable transmission and control method thereof
KR101818876B1 (en) Control device for continuously variable transmission
JP4388832B2 (en) Method and apparatus for adapting clutch torque
US9527513B2 (en) Control apparatus for vehicle
WO2016035711A1 (en) Control device for automatic transmission
US20070203631A1 (en) Torque control device for continuously variable transmission
US9255638B2 (en) Device for controlling automatic transmission
US7062986B2 (en) Methods and apparatus for operating a motor vehicle
JP2014137105A (en) Shift control device of continuously variable transmission for vehicle
US20160363068A1 (en) Control device for automatic transmission
US8818665B2 (en) Vehicle control apparatus
KR20090021139A (en) Method of controlling a transmission ratio
JP6110677B2 (en) Shift control device for continuously variable transmission
KR20140060952A (en) Transmission control system for working vehicle and method thereof
US9482337B2 (en) Controller for continuously variable transmission
US20070197323A1 (en) Hydraulic pressure control device for vehicle continuously variable transmission
JP6110676B2 (en) Shift control device for continuously variable transmission
JP5211299B2 (en) Power transmission control device
JP2024025891A (en) Control device of vehicle
KR101251546B1 (en) Engine torque limit control method
JP2008069951A (en) Shift control device for vehicular continuously variable transmission

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E601 Decision to refuse application