KR20150026475A - Continuousely variable transmission and controlling method thereof - Google Patents

Continuousely variable transmission and controlling method thereof Download PDF

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Publication number
KR20150026475A
KR20150026475A KR20130105380A KR20130105380A KR20150026475A KR 20150026475 A KR20150026475 A KR 20150026475A KR 20130105380 A KR20130105380 A KR 20130105380A KR 20130105380 A KR20130105380 A KR 20130105380A KR 20150026475 A KR20150026475 A KR 20150026475A
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KR
South Korea
Prior art keywords
load
engine
hydraulic
working machine
continuously variable
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KR20130105380A
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Korean (ko)
Inventor
김수철
정상철
김용주
윤민석
Original Assignee
엘에스엠트론 주식회사
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Application filed by 엘에스엠트론 주식회사 filed Critical 엘에스엠트론 주식회사
Priority to KR20130105380A priority Critical patent/KR20150026475A/en
Publication of KR20150026475A publication Critical patent/KR20150026475A/en

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    • 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
    • F16H61/66—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 specially adapted for continuously variable gearings
    • 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
    • F16H35/00—Gearings or mechanisms with other special functional features
    • F16H35/10—Arrangements or devices for absorbing overload or preventing damage by overload
    • F16H2035/106—Monitoring of overload
    • 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
    • F16H61/66—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 specially adapted for continuously variable gearings
    • F16H2061/6604—Special control features generally applicable to continuously variable gearings
    • F16H2061/6618—Protecting CVTs against overload by limiting clutch capacity, e.g. torque fuse

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Transmission Device (AREA)
  • Lifting Devices For Agricultural Implements (AREA)
  • Arrangement And Driving Of Transmission Devices (AREA)

Abstract

According to the present invention, a transmission to transmit power from the engine of a vehicle comprises: a first hydraulic-mechanical transmission unit coupled to the output part of the engine, and formed as a combination of a hydrostatic transmission and a mechanical differential gear; an auxiliary transmission part transmitting an output to an axle when the output is continuously varied by the first hydraulic-mechanical transmission unit; a PTO shaft transmitting the power from the engine to a working machine; an axle load measurement unit to measure an axle load applied to the first hydraulic-mechanical transmission unit; a working machine load measurement unit to measure a working machine load applied to the PTO shaft; a working machine load reduction unit to reduce the working machine load applied to the PTO shaft; and a control part performing a control to reduce the axle load by varying the output from the engine or the gear shift mode of the vehicle or performing a control to reduce the working machine load by controlling the working machine load reduction unit according to output signals from the axle load measurement unit and the working machine load measurement unit. The transmission according to the present invention is capable of preventing an overload or engine stall due to the engine overload.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a continuously variable transmission,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission and a control method thereof, and more particularly, to an hydraulic mechanical type CVT combined with a hydraulic type continuously variable transmission (HyDaulic Static Transmission; HST) and a mechanical differential device and a control method thereof.

BACKGROUND ART As a power transmission system for a working vehicle such as a tractor, a hydraulic mechanical type continuously variable transmission in which a hydraulic type continuously variable transmission (HST) and a mechanical type differential device are combined is used. Particularly, in the case of a working machine such as an agricultural tractor, it is mainly used for a heavy load work which repeats forward and backward movement. When a work is carried out using an agricultural tractor equipped with a hydraulic mechanical type continuously variable transmission, The engine speed is reduced and the engine is overloaded. Also, there is a problem that the engine stops when the overload state continues for a long time.

Conventionally, in order to prevent the overload of the engine or the engine stall phenomenon due to the overload operation state, the real time load of the engine is measured to determine whether or not the engine is overloaded and the speed ratio is controlled to compensate the engine load. . However, in the case of determining whether the engine is overloaded by detecting the engine speed, there is a problem that the cause of the load acting on the engine can not be properly identified.

 In particular, in the case of an agricultural tractor, in addition to the axle load transmitted to the engine through the axle, the load acting on the engine exists in a load acting on the engine through the working machine. 70% ~ 80%. Therefore, the fluctuation of the PTO output by the load of the working machine greatly affects the engine efficiency.

Therefore, in this case, when the engine is overloaded without discriminating between the axle load and the working machine load, and the transmission control or the engine output control is performed as in the prior art, when the engine load is generated by the working machine load, There has been a problem that proper control for saving is not achieved.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problem, and it is an object of the present invention to provide a control apparatus and a control method thereof, which, when an overload is applied to an engine, determine whether the cause of overload is in an axle load or in a load of a working machine, Thereby preventing overload or engine stall due to engine overload.

In order to achieve the above object, the present invention provides a continuously variable transmission for transmitting engine power of a vehicle, comprising: a first hydraulic mechanical type continuously variable transmission unit (1) which is combined with an output portion of an engine and is a combination of a hydraulic type continuously variable transmission (HST) A transmission for transmitting the output of the continuously variable transmission to the axle, and a PTO shaft for transmitting the output of the engine to the working machine, An axle load measuring means for measuring an axle load acting on the first hydraulic mechanical transmission continuously variable transmission unit, a working load measuring means for measuring a working load applied to the PTO shaft, The load on the work machine is reduced, and the output signal from the axle load measuring means and the load on the work machine load measuring means And a control unit for controlling the output of the engine or the shift mode of the vehicle to reduce the axle load or to control the load reducing means to reduce the load on the work machine.

Preferably, the axle load measuring means measures the axle load acting on the first hydraulic mechanical type continuously variable transmission unit by measuring the hydraulic pressure in the hydraulic circuit in the first hydraulic mechanical type continuously variable transmission unit .

Preferably, the work machine load measuring means is a pulling load sensor provided in the hydraulic apparatus connected to the work machine.

Preferably, the work machine load measuring means is a torque sensor provided on the PTO shaft.

Preferably, the work machine load reducing means is a hydraulic cylinder that raises a working machine and reduces a load applied to the engine via the PTO shaft.

Preferably, the work machine load reducing means is an electric motor connected to the PTO shaft for assisting the PTO output torque of the engine.

Preferably, the present invention further comprises a second hydraulic mechanical type transmission unit on the PTC shaft of the transmission, and the operating load measuring means measures the hydraulic pressure in the hydraulic circuit in the second hydraulic mechanical transmission continuously variable transmission unit And measuring the load on the work machine acting on the PTO shaft.

Preferably, the working machine load reducing means controls a speed ratio of the second hydraulic mechanical type continuously variable transmission unit to reduce the load on the working machine.

In order to achieve the above object, the present invention provides a transmission for transmitting engine power of a vehicle, comprising: a first hydraulic mechanical type continuously variable transmission unit coupled with an output portion of an engine and including a hydraulic type continuously variable transmission (HST) A control method of a transmission including a transmission portion for transmitting an output of a continuously variable transmission to an axle by a first hydraulic mechanical type continuously variable transmission unit and a PTO shaft for transmitting an output of the engine to a working machine, Measuring an axle load acting on the first hydraulic mechanical type continuously variable transmission unit; Performing a control to reduce the axle load when the measured axle load is compared with a predetermined load value and the axle load is equal to or greater than a predetermined load value; Measuring a work machine load acting on the PTO shaft; And performing control to reduce the load on the working machine when the measured load of the working machine is compared with the predetermined load value and the working machine load is equal to or greater than a predetermined load value.

In order to achieve the above object, the present invention provides a continuously variable transmission for transmitting engine power of a vehicle, comprising: a first hydraulic mechanical type continuously variable transmission unit (1) which is combined with an output portion of an engine and is a combination of a hydraulic type continuously variable transmission (HST) A negative speed change portion for transmitting an output of the continuously variable transmission to the axle by the first hydraulic mechanical type continuously variable transmission unit, and a PTO shaft for transmitting an output of the engine to the working machine, the method comprising: determining whether the engine is overloaded; Measuring an axle load acting on the first hydraulic mechanical type continuously variable transmission unit; Measuring a work machine load acting on the PTO shaft; When the measured axle load is equal to or greater than the predetermined load value and the working machine load is equal to or less than the predetermined load value, only the control for reducing the axle load is performed. When the measured axle load is equal to or less than the predetermined load value, A step of performing control to reduce the load on the axle and the load on the working machine when the measured axle load is equal to or greater than a predetermined load value and the working machine load is equal to or greater than the predetermined load value The present invention provides a control method for a continuously variable transmission including a continuously variable transmission.

Preferably, the step of measuring the axle load is characterized by measuring the axle load by sensing the hydraulic pressure in the hydraulic circuit of the first hydraulic mechanical type continuously variable transmission unit.

Preferably, the step of measuring the load on the work machine is characterized by measuring the load on the work machine from the measured value of the torque sensor provided on the PTO shaft or the measured value of the pulling load sensor provided on the hydraulic device connected to the working machine .

Preferably, the control for reducing the axle load is characterized by controlling an output value of the engine or an output value of the first hydraulic mechanical-mechanical transmission.

Preferably, the control for reducing the load on the work machine is performed by raising the work machine by a hydraulic cylinder so as to reduce a load applied to the work machine.

Preferably, the control for reducing the load on the work machine controls the auxiliary power source connected to the PTO shaft so as to assist the torque transmitted from the engine to the PTO shaft.

According to the present invention, appropriate control according to the cause of the load can be performed to quickly cope with an engine overload, and engine overload or engine stop due to engine overload can be effectively avoided. Further, it is possible to avoid unnecessary shift control or engine speed control when the working machine is overloaded, thereby achieving fuel economy reduction effect.

1 is a schematic view showing an embodiment of a transmission according to the present invention;
Fig. 2 is a schematic view for explaining a working vehicle for an agricultural work and a working machine structure equipped with the transmission of the present invention; Fig.
3 is a schematic view showing another preferred embodiment of the transmission according to the present invention;
4 is a flowchart of an embodiment of a transmission control method of the present invention

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

1 is a diagram schematically showing a configuration of a transmission according to an embodiment of the present invention.

Referring to FIG. 1, a transmission according to an embodiment of the present invention is a structure for transmitting the driving force of the engine 1 to an axle. The transmission 1 is connected to an output section of the engine 1, 1 hydraulic mechanical continuously variable transmission unit 20 and an auxiliary transmission portion 30 for transmitting the output of continuously variable transmission to the axle 40 by the first hydraulic mechanical transmission continuously variable transmission unit 20.

The transmission according to the present embodiment is a structure for transmitting the driving force of the engine to the working machine and is connected to the output portion of the engine 1 to drive the working machine 60 of the tractor 2, (Not shown).

The transmission according to the present embodiment is provided with detecting means for determining the cause of the load applied to the engine and includes an axle load measuring means 70 for measuring an axle load acting on the first hydraulic mechanical type continuously variable transmission unit 20 And an engine load reducing control unit 80 which receives an output signal from the axle load measuring unit 70 and the loader measuring unit 80, And an engine load value measuring means 120 for executing the engine load value measurement.

The transmission according to the present embodiment includes a working load reducing means 90 provided on the PTO shaft 50 between the engine 1 and the working machine 60 as means for reducing the load applied to the working machine .

The engine 1 is a diesel engine, a gasoline engine, or a propane engine. The output of the engine 1 is determined according to the application in which the work machine is used, and is a driving source for driving the work machine and a power source for the work machine mounted on the work machine.

The first hydraulic mechanical transmission unit 20 includes a hydraulic type transmission (HST) 21 and a mechanical differential device 22. The hydraulic stepless transmission 21 is a mechanism for obtaining a continuously variable transmission by continuously controlling the flow rate of the working fluid by using a hydraulic pump. The hydraulic stepless transmission of the present invention is a well-known configuration, which is not described in detail herein . The mechanical differential device 22 includes an output continuously variable by the hydraulic type continuously variable transmission 22 among the driving force of the engine transmitted from the output portion of the engine 1 via the drive input shaft 10 and an output from the hydraulic type continuously variable transmission 22 And transmits the combined driving force selectively to the auxiliary speed change section 30. [0051] As the mechanical differential device 22, a planetary gear mechanism composed of a plurality of gears is generally used and is known at the time of filing of the present invention, but is not described in detail in the specification of the present invention.

The PTO shaft 50 serves to transmit the rotational force from the output portion of the engine 1 to the working machine 60. The working machine according to the present invention is a tractor mainly used for agricultural use for digging the ground or pushing soil. A working machine such as a rotary or a plow is attached to the rear of the tractor, and the tractor is advanced Work is done.

The axle load measuring means 70 is a means for measuring an axle load (running load) applied to the engine 1 through the first hydraulic mechanical transmission unit 20. [ When the tractor is in operation, the driving load may act on the engine due to the force that the axle of the tractor comes into contact with the foreign matter and stops. According to the preferred embodiment of the present invention, the axle load measuring means for measuring the axle load applied to the engine 1 via the first hydraulic mechanical transmission unit 20 is constituted by the hydraulic circuit of the first hydraulic mechanical transmission unit 20 Is a hydraulic pressure gauge for measuring the hydraulic pressure in the pipe. The external load applied to the first hydraulic mechanical transmission unit 20 is applied in the form of a hydraulic load in the hydraulic circuit so that when a sudden running load is increased on the tractor, By detecting an increase in the fluid pressure in the circuit, an increase in load can be detected and the axle load can be measured.

The machine load measuring means 80 is means for measuring the machine load applied to the engine 1 via the PTO shaft. When the soil where the tractor works is farmed, most of the wetland and roads are irregularly packed. In this case, if the working machine is caught by irregularly shaped foreign matter on the ground and obstructs the rotation of the PTO shaft, The engine 1 can be overloaded.

According to a preferred embodiment of the present invention, the machine load measuring means 80 may be a traction load sensor. The traction load sensor detects the traction load by receiving the displacement of the force acting in the direction that interferes with the tractor's progress. When a traction load sensor is provided in a working machine, there is a disadvantage in that a sensor must be provided for each working machine installed at the rear of the tractor, and reliability of the sensor may be a problem. Therefore, . The hydraulic device 91 shown in FIG. 2 is arbitrarily operated by a lever operation of the driver, and performs a function of adjusting the hydraulic pressure to control the height of the lifting and lowering of the working machine by using the three-point hitch device 92.

According to a preferred embodiment of the present invention, the working load measuring means 80 may be a torque sensor provided on the PTO shaft. When using the torque sensor, it is possible to detect whether or not the working load is applied by detecting the twist angle of the PTO shaft by the torque load applied to the PTO shaft by the working machine.

The engine load value measuring means 120 measures the real time load value applied to the engine and outputs the measurement result to the control unit 100 as an output signal. The real time load value can be detected by measuring the real time fuel supply amount etc. supplied to the engine, and there are a number of known techniques for measuring the engine load, which will not be described in detail in the specification of the present invention.

The control unit 100 measures the real time load value applied to the engine through the real time flow rate of the engine or the like to determine whether the engine is overloaded or not and outputs the output signal from the axle load measuring means 70 and the working load measuring means 80 And performs a role of determining whether the load applied to the engine upon receipt of the input is due to axle load or work machine load. Further, the control unit 100 controls the working machine load reducing means 90, which will be described later, in accordance with the determination result, or reduces the running load of the tractor by controlling the rotation speed or the transmission ratio of the engine, .

Fig. 2 is a schematic view for explaining a working vehicle for a working vehicle and a working machine equipped with the transmission of the present invention, and shows the working load reducing means 90 in the preferred embodiment according to the present invention. 2, a working machine 60 mounted on the PTO shaft 50 at the rear of the tractor 2 is shown. When the control unit 100 determines that the working machine load of the tractor 2 is buried in the soil so that the load of the working machine is generated, the control unit 100 controls the hydraulic pressure in the hydraulic system 91 The three-point hitch device 92 is pulled to the right side of the drawing by the pump (not shown), and the work machine 60 is lifted upward. As a result, the load on the PTO side of the working machine can be reduced.

Further, according to a preferred embodiment of the present invention, the work machine load reducing means 90 may be an electric motor provided between the PTO shaft and the engine. The electric motor transmits the mechanical energy to the PTO shaft in accordance with the control signal generated by the control unit 100, so that when the working machine is loaded with a high load, the output from the engine 1 is assisted to reduce the working machine load.

3 is a diagram schematically showing a configuration of a transmission according to another preferred embodiment of the present invention. 1, as the working load measuring means 80 and the working load reducing means 90, the second hydraulic mechanical transmission unit 110 .

The second hydraulic mechanical transmission unit 110 shown in Fig. 3 is provided on the PTO shaft 60 between the PTO shaft 50 and the output portion of the engine 1 and is provided with a hydraulic type continuously variable transmission (111) and a mechanical differential (112). The driving force of the engine shifted by the second hydraulic mechanical transmission unit 110 is transmitted to the working machine 80 via the PTO shaft 50.

In the embodiment shown in Fig. 3, the machine load measuring means 90 is a hydraulic pressure meter for measuring the hydraulic pressure in the hydraulic circuit of the second hydraulic mechanical transmission unit 110. Fig. The work machine load applied to the second hydraulic mechanical transmission unit 110 is applied in the form of a hydraulic load in the hydraulic circuit so that the load of the second hydraulic mechanical transmission unit 110 The increase of the load can be detected by sensing the increase of the fluid pressure in the hydraulic circuit by the hydraulic pressure meter provided in the hydraulic circuit. Further, in the embodiment shown in Fig. 3, the work machine load is reduced by controlling the speed ratio of the second hydraulic mechanical transmission unit 110. [

4, an embodiment of a control method for controlling the transmission according to the embodiment of the present invention is shown.

First, the real-time load value of the engine 1 of the tractor is measured to determine whether the engine is overloaded (S10). The real-time load value of the engine 1 can be determined, for example, by measuring the amount of real-time fuel injected into the engine or the like. Means for engine load determination are well known in the art and are not described in detail herein. Whether or not the engine is overloaded is determined by comparing the real-time load value of the engine 1 with the threshold load value according to the running state of the vehicle. For example, the threshold load value may be a load value of the engine output torque corresponding to the traveling speed of the current tractor 2 under the working conditions of a general tractor in which no overload or engine stall occurs.

When it is determined that the engine 1 is overloaded, the axle load acting on the first hydraulic mechanical type stepless transmission unit is measured (S20). According to a preferred embodiment of the present invention, the axle load is achieved by sensing the hydraulic pressure in the hydraulic circuit of the first hydraulic mechanical type transmission by the hydraulic pressure meter. The axle load acting from the axle acts as a hydraulic load in the hydraulic circuit, and the load value is output to the control unit 100 through an output signal from the hydraulic pressure meter.

In step S30, the control unit 100 determines whether the measured axle load value is greater than or equal to a predetermined load value by comparing the measured axle load value with the first predetermined value. According to a preferred embodiment of the present invention, the determination step (S30) determines the hydraulic pressure value in the hydraulic circuit of the first hydraulic mechanical transmission < Desc / Clms Page number 11 > Here, the predetermined hydraulic pressure value may be a reference value corresponding to the vehicle speed of the tractor 2 at the time of normal running, for example.

When the measured axle load value is determined to be equal to or greater than the predetermined load value, the control unit 100 performs control for reducing the axle load (S40). According to a preferred embodiment of the present invention, the control for reducing the axle load is to control the output value of the engine or the output value of the first hydraulic mechanical stepless transmission to decelerate the tractor 2.

In the control method according to the present invention, the work machine load acting on the PTO shaft 50 is also measured (S50). According to a preferred embodiment of the present invention, the work machine load is measured by a torque sensor provided in the pulling load sensor or the PTO shaft 50 provided in the hydraulic device 91 connected to the working machine 60. The measured value is output to the control unit 100 through the output signal from the above-mentioned working machine load measuring means 80.

When the measured work machine load value is determined to be equal to or greater than the second predetermined value (S60), the control unit 100 performs control for reducing the work machine load (S70). According to the preferred embodiment of the present invention, the control for reducing the load on the work machine is performed by the hydraulic pump in the hydraulic device 91, by means of the control signal generated by the control unit 100, 60). According to another preferred embodiment of the present invention, control for reducing the load on the work machine is performed in such a manner that an auxiliary power source connected to the PTO shaft 50 assists the torque of the engine 1 in accordance with a control signal generated by the control unit 100 To the PTO shaft (50).

According to another preferred embodiment of the present invention, when the axle load and the work machine load simultaneously act on the engine 1, the control S40 for reducing the axle load and the control S70 for reducing the work machine load are performed at the same time Lt; / RTI > That is, according to a preferred embodiment of the present invention, after measuring the axle load and the work machine load, if the measured axle load is equal to or greater than the predetermined load value and the measured work machine load is equal to or less than the predetermined load value, Only the control is carried out. When the measured axle load is equal to or less than the predetermined load value and the measured working load is equal to or greater than the predetermined load value, only the control for reducing the working load is performed. When the measured work machine load is equal to or greater than the predetermined load value, control for reducing the axle load and the work machine load is carried out together. According to the preferred embodiment of the present invention, when an operation is performed using a tractor in a farmland or the like where the ground surface is irregular, when both the axle and the working machine are overloaded, control is performed to reduce both loads at the same time, Can be removed quickly.

1: Engine 2: Tractor
10: drive input shaft 20: first hydraulic mechanical stepless transmission unit
21: Hydraulic stepless transmission 22: Mechanical differential
30: auxiliary speed change section 40: axle
50: PTO shaft 60: working machine
70: axle load measuring means 80: working machine load measuring means
90: Machine load reducing means 91: Hydraulic device
92: 3-point hitch device 100:
110: second hydraulic mechanical transmission unit 111: hydraulic continuously variable transmission
112: mechanical differential device 120: engine load value measuring means

Claims (15)

A continuously variable transmission for transmitting engine power of a vehicle, comprising: a first hydraulic mechanical type continuously variable transmission unit, which is coupled to an output portion of the engine and is a combination of a hydraulic type continuously variable transmission (HST) and a mechanical differential, And a PTO shaft for transmitting an output of the engine to a working machine,
Measuring means for measuring a real time load value of the engine,
An axle load measuring means for measuring an axle load acting on said first hydraulic mechanical type continuously variable transmission unit,
A work machine load measuring means for measuring a work machine load acting on the PTO shaft,
And a work machine load reducing means for reducing a work machine load acting on the PTO shaft,
And controls the output of the engine or the shift mode of the vehicle to change the axle load in accordance with the output signal from the axle load measuring means and the working machine load measuring means or controls the load reducing means to reduce the load on the working machine A continuously variable transmission comprising a control part. The method according to claim 1,
Characterized in that the axle load measuring means measures the axle load acting on the first hydraulic mechanical type continuously variable transmission unit by measuring the hydraulic pressure in the hydraulic circuit in the first hydraulic mechanical transmission & . The method according to claim 1 or 2,
Wherein the working load measuring means is a pulling load sensor of the hydraulic device connected to the working machine. The method according to claim 1 or 2,
Wherein the working machine load measuring means is a torque sensor provided on the PTO shaft. The method according to claim 1,
Wherein the working machine load reducing means is a hydraulic cylinder that raises the working machine and reduces a load applied to the engine via the PTO shaft. The method according to claim 1,
Wherein the working machine load reducing means is an electric motor connected to the PTO shaft for assisting the PTO output torque of the engine. The method according to claim 1,
Further comprising a second hydraulic mechanical type transmission on the PTO shaft of the transmission,
Characterized in that the pressure of the working machine acting on the PTO shaft is measured by measuring the hydraulic pressure in the hydraulic circuit in the second hydraulic mechanical unit continuously variable transmission unit The method of claim 7,
Wherein the working machine load reducing means controls the speed ratio of the second hydraulic mechanical type continuously variable transmission unit to reduce the load on the work machine. A continuously variable transmission for transmitting engine power of a vehicle, comprising: a first hydraulic mechanical type continuously variable transmission unit, which is coupled to an output portion of the engine and is a combination of a hydraulic type continuously variable transmission (HST) and a mechanical differential, And a PTO shaft for transmitting an output of the engine to a working machine, the control method comprising the steps of:
Determining whether the engine is overloaded;
Measuring an axle load acting on the first hydraulic mechanical type continuously variable transmission unit;
Performing a control for reducing an axle load when the measured axle load is compared with a predetermined load value and the axle load is equal to or greater than a predetermined load value;
Measuring a work machine load acting on the PTO shaft;
And performing control to reduce the load on the work machine when the measured load on the work machine is compared with a predetermined load value and the load on the work machine is equal to or greater than a predetermined load value. A continuously variable transmission for transmitting engine power of a vehicle, comprising: a first hydraulic mechanical type continuously variable transmission unit, which is coupled to an output portion of the engine and is a combination of a hydraulic type continuously variable transmission (HST) and a mechanical differential, And a PTO shaft for transmitting an output of the engine to a working machine, the control method comprising the steps of:
Determining whether the engine is overloaded;
Measuring an axle load acting on the first hydraulic mechanical type continuously variable transmission unit;
Measuring a work machine load acting on the PTO shaft;
When the measured axle load is equal to or greater than a predetermined load value and the working machine load is equal to or less than a predetermined load value, only the control for reducing the axle load is performed,
When the measured axle load is equal to or less than a predetermined load value and the working machine load is equal to or greater than a predetermined load value, only the control for reducing the working machine load is performed,
And performing control to reduce an axle load and a load of a working machine when the measured axle load is equal to or greater than a predetermined load value and the working machine load is equal to or greater than a predetermined load value. The method according to claim 9 or 10,
Wherein the step of measuring the axle load comprises measuring the axle load by sensing the hydraulic pressure in the hydraulic circuit of the first hydraulic mechanical type continuously variable transmission unit. The method according to claim 9 or 10,
Wherein the step of measuring the load on the work machine measures a load on the work machine from a measured value of a torque sensor provided on the PTO shaft or a measured value of a pull load sensor provided on a hydraulic device connected to the working machine, Way. The method according to claim 9 or 10,
Wherein the control for reducing the axle load controls an output value of the engine or an output value of the first hydraulic mechanical type CVT. The method according to claim 9 or 10,
Wherein the control for reducing the load on the work machine is performed by raising the work machine by a hydraulic cylinder so as to reduce a load applied to the work machine. The method according to claim 9 or 10,
Wherein the control for reducing the load on the work machine controls an auxiliary power source connected to the PTO shaft to assist the torque transmitted from the engine to the PTO shaft.
KR20130105380A 2013-09-03 2013-09-03 Continuousely variable transmission and controlling method thereof KR20150026475A (en)

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KR20130105380A KR20150026475A (en) 2013-09-03 2013-09-03 Continuousely variable transmission and controlling method thereof

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