CN112005707A

CN112005707A - Motor drive-based automatic variable speed control system and device for harvester

Info

Publication number: CN112005707A
Application number: CN202010831316.0A
Authority: CN
Inventors: 迟新伟; 王喜恩; 安冬冬; 廖文; 王玉强; 李保忠; 于志威; 赵玉珍
Original assignee: Anhui Juli Innovation Project Management Co ltd; Luoyang Intelligent Agricultural Equipment Research Institute Co Ltd
Current assignee: Anhui Juli Innovation Project Management Co ltd; Luoyang Intelligent Agricultural Equipment Research Institute Co Ltd
Priority date: 2020-08-18
Filing date: 2020-08-18
Publication date: 2020-12-01

Abstract

The invention discloses an automatic speed change control system and device of a harvester based on motor drive, which relate to the technical field of harvesters and aim at the problems that the existing harvester cannot fully decelerate when the load is increased sharply and is inconvenient to operate, the invention provides a scheme that comprises a machine body, a power-driven working device with an engine and a position detection mechanism, and is characterized in that the power-driven working device with the engine comprises a power-driven swash plate type pump with the engine and a fluid driving motor discharged by the pump, and a stepless speed change device for outputting the power of the motor; a pair of left and right traveling devices supporting the machine body and driven by power output from the continuously variable transmission. The HMT variable speed controller and the mechanical gearbox are combined for use, the variable speed range is enlarged, the speed precision is improved, the problem that a machine body is not suitable for a driver when the speed changes suddenly is reduced, and the riding comfort of an operator is improved.

Description

Motor drive-based automatic variable speed control system and device for harvester

Technical Field

The invention relates to the technical field of harvesters, in particular to an automatic variable speed control system and device of a harvester based on motor driving.

Background

In a combine harvester, roots of grain stalks standing in a field are harvested by a harvesting device, the harvested grain stalks are conveyed from the harvesting device to a threshing device, the grain stalks are threshed by the threshing device, the grains are collected in a grain tank, and the grains are conveyed by a conveying system into a preparation device. In a combine harvester, an engine is used as a power driving source, power from the engine is transmitted to a working device such as a harvesting device and a threshing device, and power from the engine is transmitted to a traveling device composed of a pair of left and right wheels

Therefore, the load of the engine varies depending on the state of work in the work machine. When the load on the work machine becomes large and the load on the engine becomes excessive (overload), the number of revolutions of the engine decreases, and the engine may be stopped. The power transmitted to the traveling device may be shifted by a continuously variable transmission, and a shift lever operated to adjust the shifting by the continuously variable transmission is provided on the driver's seat. Therefore, when the load of the engine exceeds a predetermined value, automatic control is executed to reduce the traveling speed of the machine body by operating the shift lever by the motor in order to reduce the engine load.

However, in the configuration in which the traveling speed is reduced via the motor, the reduction in speed may not be sufficient when the load of the work machine increases rapidly, and the engine may not be stopped due to the reduction in engine rotation.

For example, in a combine equipped with an HMT (hydraulic Mechanical transmission), an HMT hydraulic pump is driven by power of an engine, a hydraulic motor is driven by oil discharged from the hydraulic pump, power of the hydraulic motor is transmitted to a Mechanical transmission, and finally, power is transmitted to left and right wheels by the Mechanical transmission.

The shift lever is provided on the driver's seat so as to be displaceable from a neutral position to a forward position on the front side and a reverse position on the rear side. When the shift lever is operated from the neutral position to the forward position, the swash plate of the HMT hydraulic pump tilts to one side from the neutral position, the oil supplied from the HMT hydraulic pump to the hydraulic motor flows in one direction at a flow rate corresponding to the tilt angle of the swash plate of the HMT hydraulic pump, and the hydraulic motor rotates in the forward direction at a rotation speed corresponding to the flow rate of the supplied oil. The power in the advancing direction is transmitted to the left and right wheels after the secondary speed change of the mechanical gearbox, and the machine body advances. On the other hand, when the shift lever is operated from the neutral position to the reverse position, the swash plate of the HMT hydraulic pump tilts from the neutral position to the other side, the oil supplied from the HMT hydraulic pump to the hydraulic motor flows in the other direction at a flow rate corresponding to the tilt angle of the swash plate of the HMT hydraulic pump, and the hydraulic motor rotates in the reverse direction at a rotation speed corresponding to the flow rate of the supplied oil. The power in the backward direction is transmitted to the left and right wheels after the secondary speed change of the mechanical gearbox, and the machine body moves backward. When the shift lever is returned from the forward position or the reverse position to the neutral position, the swash plate of the HMT hydraulic pump is returned to the neutral position, the supply of the oil from the HMT hydraulic pump to the hydraulic motor is stopped, and the hydraulic motor is braked to stop the machine body.

The combine harvester is provided with a brake pedal for stopping the combine harvester, a brake for stopping the combine harvester by a stepping operation, and a link mechanism for returning a shift lever to a neutral position in accordance with stepping of the brake pedal for stopping the combine harvester.

When the parking brake pedal is depressed in a state where the shift lever is in the forward position or the reverse position and power is transmitted to the left and right wheels after shifting from the hydraulic motor through the mechanical transmission, if the return of the shift lever to the neutral position is slower than the operation of the parking brake, there is a possibility that the parking brake burns out the lamp. Therefore, the link mechanism needs to be adjusted so that the shift lever is returned to the neutral position before the parking brake is actuated.

Further, since the link mechanism is connected to the shift lever, the operating load of the shift lever becomes large or the operator feels uncomfortable with the operation of the shift lever.

Disclosure of Invention

The invention provides an automatic variable speed control system and device of a harvester based on motor driving, which solve the problems that the existing harvester cannot fully decelerate when the load is increased sharply and is inconvenient to operate.

In order to achieve the purpose, the invention adopts the following technical scheme:

the automatic speed change control system of the harvester based on the motor drive comprises a machine body, a power-driven working device with an engine and a position detection mechanism, and is characterized in that the power-driven working device with the engine comprises a power-driven swash plate type pump with the engine and a fluid driving motor discharged by the pump, and a stepless speed change device for outputting the power of the motor;

a pair of left and right traveling devices which support the machine body and are driven by power output from the continuously variable transmission; and an operation member that is operated to instruct a traveling speed of the traveling machine body by the traveling device, the position detection means being capable of detecting a position of the operation member;

a deceleration rate setting means for setting a deceleration rate corresponding to whether or not the load value corresponding to the engine exceeds a reference value and whether or not the load value exceeds the reference value;

a target position setting mechanism that sets a target position of a swash plate of the HMT hydraulic pump and a target position of a mechanical transmission dial so that a travel speed of the machine body is decelerated from a speed corresponding to the position detected by the position detection mechanism and a deceleration rate by the deceleration rate operation strategy;

and a control means for controlling the continuously variable transmission so that the swash plate position of the HMT hydraulic pump coincides with the target position set by the target position setting means.

Preferably, the position detection mechanism includes a shift lever position sensor, an HMT pump swash plate position sensor and a mechanical transmission range dial position sensor.

Be provided with the driver's cabin on the organism, the left side of driver's cabin is equipped with unloads the grain device, it is equipped with cereal collection granary to unload the below of grain device, the below that the granary was collected to cereal is equipped with cleaning plant, the below of driver's cabin is equipped with cereal conveyer, cereal conveyer's bottom articulates there is header lift cylinder, cereal conveyer's right side is equipped with reaping apparatus, the last rotation of reaping apparatus is connected with reel, reaping apparatus's front is equipped with reel drive mechanism, reaping apparatus's right side bottom is equipped with the cutting knife, reaping apparatus's front bottom is equipped with header height monitoring mechanism.

Preferably, the inside of driver's cabin is equipped with the saddle, the saddle openly is equipped with the operation panel, be equipped with the gear shift lever on the operation panel, the right side of gear shift lever is equipped with gear, header, reel operating handle, the right side of saddle is equipped with the direction machine.

Preferably, a plurality of wheels are arranged at the bottom of the cleaning device.

Compared with the prior art, the invention has the beneficial effects that:

1. the technical scheme of the invention has wide application range, and can be used on a combine harvester, other agricultural machines or a motor vehicle with a stepless speed change device;

2. the control mechanism of the technical scheme of the invention comprises a gear lever, a gear lever position detection mechanism, a complete machine ECU speed calculation mechanism, a servo motor, a linkage mechanism, an HMT pump swash plate, a mechanical gearbox pump swash plate and the like, is controlled by pure electric control, and reduces oil passages and mechanical linkage mechanisms.

3. The technical scheme of the invention has strong expansibility, can be combined with automatic driving, can completely realize the automatic driving operation function of the combine harvester according to the comparison between the designed working condition value and the actual working condition value, and reduces the labor intensity of operators.

Drawings

FIG. 1 is a partial front view of the automatic transmission control system and device for a harvester based on motor driving according to the present invention;

FIG. 2 is a schematic diagram of a partial electrical structure of an automatic transmission control system and device for a harvester based on motor driving according to the present invention;

FIG. 3 is a schematic view of an HMT control structure of the system and device for controlling the automatic transmission of the harvester based on the motor drive of the present invention;

FIG. 4 is a schematic diagram of a mechanical transmission control structure of the harvester automatic transmission control system and device based on motor drive according to the present invention;

FIG. 5 is a schematic diagram of the working state structure of the pump swash plate of the HMT continuously variable transmission based on the automatic variable speed control system and device of the harvester driven by the motor;

fig. 6 is a schematic view of the operation state structure of the mechanical gearbox dial of the harvester automatic speed change control system and device based on motor drive provided by the invention.

In the figure: the grain harvester comprises a cleaning device 1, a grain collecting granary 2, a grain unloading device 3, a cab 4, a direction machine 5, an operation table 6, a gear 7, a cutting table, a reel operating handle 8, a gear lever 9, a grain conveying device 10, a harvesting device 11, a reel 12, a reel transmission mechanism 13, a cutter 14, a cutting table height monitoring mechanism 15, a cutting table lifting oil cylinder 16 and wheels 17.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

Referring to fig. 1 to 6, an automatic transmission control system of a harvester based on motor driving includes a body, a power-driven working device having an engine, and a position detecting mechanism, the power-driven working device having the engine includes a power-driven swash plate type pump having the engine and a fluid-driven motor discharged from the pump, and a continuously variable transmission outputting power of the motor;

In this embodiment, the position detection mechanism includes a shift lever position sensor, an HMT pump swash plate position sensor, and a mechanical transmission range dial position sensor.

Be provided with driver's cabin 4 on the organism, the left side of driver's cabin 4 is equipped with unloads grain device 3, the below of unloading grain device 3 is equipped with cereal and collects granary 2, the below that cereal was collected granary 2 is equipped with cleaning plant 1, the below of driver's cabin 4 is equipped with cereal conveyer 10, cereal conveyer 10's bottom articulates there is header lift cylinder 16, cereal conveyer 10's right side is equipped with reaping apparatus 11, it is connected with reel 12 to rotate on the reaping apparatus 11, reaping apparatus 11's front is equipped with reel drive mechanism 13, reaping apparatus 11's right side bottom is equipped with cutting knife 14, reaping apparatus 11's front bottom is equipped with header height monitoring mechanism 15.

In this embodiment, a seat 9 is provided inside the cab 4, an operation table 6 is provided on the front surface of the seat 9, a shift lever 8 is provided on the operation table 6, a gear, a header, and a reel operating handle 7 are provided on the right side of the shift lever 8, and a steering gear 5 is provided on the right side of the seat 9.

In this embodiment, a plurality of wheels 17 are provided at the bottom of the cleaning device 1.

The operation principle is that, first, a deceleration rate is set according to whether or not the load value corresponding to the engine exceeds a reference value, and a target position of a swash plate of the HMT hydraulic pump and a target position of a dial of a sub-transmission (mechanical transmission) are set so that the traveling speed of the machine body is decelerated from a speed according to the position of the operation member and the deceleration rate. Then, the continuously variable transmission is controlled so that the position of the swash plate of the HMT hydraulic pump coincides with the target position and the target position of the sub-transmission (mechanical transmission) dial. Thus, compared to control in which the target position of the swash plate of the HMT hydraulic pump and the target position of the dial of the sub-transmission (mechanical transmission) are changed by actuating the operation member by an actuator such as a hydraulic motor or a clutch to reduce the traveling speed of the machine body, the responsiveness of the control is high, the range of operation is small, the control accuracy range is wide, and the traveling speed of the machine body can be reduced with good follow-up performance even for a sudden increase in the load of the engine due to a sudden change in the load of the working device.

When the load corresponding value exceeds the reference value, the deceleration rate operation strategy sets a deceleration rate including a proportional term set by multiplying a proportional gain by a deviation of the corresponding value from the reference value. Accordingly, the deceleration rate is set to a larger value as the deviation of the coincidence correspondence value from the reference value is larger, and therefore the traveling speed of the engine body can be reduced with better following ability against a sudden increase in the engine.

The deceleration-rate operation strategy may set the deceleration rate by adding an integral term, which is set by multiplying an integral gain by an integral value of a deviation of the load corresponding value from the reference value, to a proportional term in the case where the load corresponding value exceeds the reference value.

In the deceleration rate operation strategy, the proportional term may be eliminated in response to a change in the load corresponding value from a value exceeding the reference value to a value below the reference value, and the deceleration rate including the integral term may be set so that the traveling speed of the machine body is accelerated toward a speed corresponding to the position monitored by the position detecting means.

In this case, the deceleration rate operation strategy sets the deceleration rate including the integral term after addition by adding the integral term to the deceleration rate of the proportional term set to disappear when the proportional term disappears in response to the load corresponding value changing from the value exceeding the reference value to the value equal to or less than the reference value. Thus, when the traveling speed of the machine body shifts from the deceleration state to the state of returning to the normal speed by acceleration, the rapid change of the deceleration rate can be suppressed. Further, the deceleration rate changes with a slow change in the integral term, and the traveling speed of the machine body is slowly accelerated (increased) with the change in the deceleration rate, so that a rapid increase in the traveling speed, fluctuation, or the like of the machine body can be suppressed. Therefore, the riding comfort of the operator can be improved.

The target position setting means may set the target position based on a multiplier obtained by multiplying the deceleration rate by a value indicating the position detected by the position detecting means.

The complete machine ECU receives a speed signal from a speed sensor, a working condition or speed setting signal of a working display, a sub-gearbox dial position detection mechanism feedback signal and a position signal of a swash plate of the HMT hydraulic pump respectively. And data analysis is carried out through an analysis system module, and a calculation result instruction is sent to the servo motor to enable the servo motor to act, so that the position of a swash plate of the gearbox pump is driven to change, and the driving power of the motor to a pair of left and right wheels is changed by controlling the flow rate of fluid discharged by the gearbox pump and the HMT hydraulic pump and flowing to the motor.

When the swash plate position of the HMT hydraulic pump swash plate is in the forward position, the HMT hydraulic pump swash plate detection mechanism sends a signal to the complete machine ECU. The ECU of the complete machine receives a speed signal monitored by the speed sensor, compares a set value of the speed with a speed value monitored by the speed sensor to calculate a difference value between the set value and the speed of the complete machine, and sends a result calculated by the speed calculation mechanism of the ECU of the complete machine to the servo motor to enable the servo motor to act according to an instruction. When the servo motor acts, the position of the swash plate of the transmission pump is enabled to be towards the position of a set value through the servo motor and the transmission linkage mechanism.

When the speed set value calculated by the complete machine ECU calculation mechanism and the numerical value monitored by the complete machine speed sensor are larger than zero, the command sent to the servo motor by the complete machine ECU is the action in the accelerating direction, and the servo motor rotates anticlockwise, so that the positions of the servo motor and the variable box pump swash plate move to one side of the accelerating direction to realize the accelerating function.

When the speed set value calculated by the complete machine ECU calculation mechanism and the numerical value monitored by the complete machine speed sensor are less than zero, the command sent to the servo motor by the complete machine ECU is the action in the speed reduction direction, and the servo motor rotates clockwise in the reverse time, so that the positions of the servo motor and the variable box pump swash plate move to one side in the speed reduction direction to realize the speed reduction function.

In the attached figure 1, a driving cab, a harvesting device, a threshing device, a grain bin for collecting grains, a grain unloading device and the like are arranged on the harvester.

The cab is disposed above the front end portions of the wheels of the running gear. A seat on which an operator sits is provided in the cab. In addition, an operation control panel and a steering device operated by an operator are provided on the right side and the front side of the seat in the cab.

The operation panel is provided with a shift lever, a hand throttle, a work display, and the like. The shift lever is provided to be tiltable in the front-rear direction. The operator can instruct the forward movement of the body by tilting the shift lever forward. The speed of the forward movement can be changed by the amount of tilt. Further, the operator can instruct the body to retreat by tilting the shift lever to the rear side, and can change the speed of retreat by using the amount of tilting.

The harvesting device is arranged in front of the machine body. The harvesting device is provided with a reel at the front end thereof and a harvesting knife below the reel. A harvester cross arm box body extending along the left-right direction is arranged at the rear end part of the harvesting device, and one end of the harvesting device is connected with the harvester cross arm box body. The harvesting device extends backwards from the cross beam box body of the harvester, and the other end of the harvesting device can be rotatably connected with the machine body frame. Through the action of the header lifting cylinder body, the harvesting device swings. The distance of the harvesting device from the ground is controlled by the swing. Under the working state, the harvesting device dials the grains to the harvesting device through the rotation of the reel, and then the grains are harvested by the cutting knife.

Cleaning plant and grain bin that cereal was collected. Above the wheels and in which the grain conveyor is in the middle of the harvester body. The harvested grains are conveyed to the cleaning device by the grain conveying device and threshed by the cleaning device. And the grains are conveyed to a grain bin for grain collection through a grain lifting device. The grain unloading device is connected with a grain bin for collecting grains, and the grains in the grain bin can be discharged outside the machine body by the grain unloading device.

In fig. 2, an engine ECU, an HMT, and a sub-transmission are mounted in the combined harvest. The HMT and the subtransmission (secondary shift) shift and output the power of the engine. Specifically, the HMT includes a hydraulic pump driven by power of the engine and a hydraulic motor driven by fluid discharged from the hydraulic pump. The hydraulic pump is a variable displacement swash plate type piston pump.

In fig. 5, the inclination angle of the pump swash plate with respect to the axis of the pump rotating shaft of the hydraulic pump is in the range of 0 ° to 21 °, the HMT transmission is in the forward range, and the larger the inclination angle is, the more the hydraulic oil is discharged from the hydraulic pump. When the inclination angle of the pump swash plate is in the range of 0-12.1 degrees, the HMT gearbox is in a neutral zone, and the discharge of the hydraulic oil of the hydraulic pump is stopped. When the inclination angle of the pump swash plate is in the range of-12.1 to 21 degrees, the HMT gearbox is in a reverse gear region, and the discharge direction of the working oil from the hydraulic pump is reversed. The hydraulic motor is a variable displacement swash plate piston motor. When the inclination angle of the motor swash plate with respect to the axis of the motor rotary shaft of the hydraulic motor is constant, the rotation speed of the motor rotary shaft increases as the amount of hydraulic oil supplied to the hydraulic motor, that is, the amount of hydraulic oil discharged from the hydraulic pump increases.

The servo motor speed regulating mechanism moves the swash plate of the HMT pump in the moving range of the swash plate through the transmission mechanism.

In fig. 6, the addition of the sub-transmission (secondary shift) makes the shifting smoother and reduces the mechanical shock associated with the shifting. The auxiliary transmission is connected with the HMT by adopting a spline shaft. Meanwhile, power is transmitted to the mechanical gearbox through the spline shaft, and after mechanical speed change of the mechanical gearbox, the power is transmitted to the left wheel and the right wheel through an output shaft of the mechanical gearbox, so that the purposes of secondary speed change and speed regulation range increase are achieved.

The angle of inclination of the range dial relative to the axis of the power input shaft is 78 DEG and 102 DEG, and the range dial is in a low gear at 78 DEG or a high gear at 102 DEG in the working state.

The speed regulating mechanism of the servo motor moves the gear driving plate in the movable range of the gear driving plate through the transmission mechanism and moves the driving plate to a specified position.

The power of the engine is transmitted to the left and right running devices after being shifted by the HMT gearbox and the auxiliary gearbox, and in addition, the power of the engine is transmitted to the harvesting device and the threshing device without being shifted by the HMT gearbox and the auxiliary gearbox. The independent power of the harvesting device and the walking device is realized by a double pump at the power output end of the engine. Power transmission mechanisms including clutches and the like are respectively interposed between the HMT, the sub-transmission and the traveling device, between the engine and the harvesting device, and between the engine and the threshing device.

A combine harvester is mounted with a single main ECU (Electronic Control Unit) for overall unified Control and a plurality of ECUs for individual specific Control. The ECUs used for specific control of an individual include, for example, an engine ECU, an HMTECU, and the like. The main ECU, the engine ECU, and the HMTECU are each included as a Controller unit (MCU: Micro Controller U nit).

The main ECU is communicably connected to each ECU for individual specific control, that is, the engine ECU, the HMTECU, and the like. The main ECU receives information acquired from monitoring signals of various sensors by each ECU having specific control, and transmits commands and information necessary for the control of each ECU to each ECU.

The engine ECU receives an instruction from the main ECU to control the engine.

An operation position sensor of the main shift lever is connected to the HMTECU, and a detection signal of the shift lever position sensor is input to the HMTECU. Further, a position sensor of a pump swash plate of the hydraulic pump of the HMT is connected to the HMTECU, and a detection signal of the pump swash plate position sensor is input to the HMTECU. The HMTECU receives a command from the main ECU, and controls the HMT based on information obtained from the detection signals of the shift lever position sensor and the pump swash plate position sensor.

An operation position sensor of the sub-shift lever is connected to the main ECU, and a detection signal of the shift lever position sensor is input to the main ECU. A position sensor of a pump swash plate of a hydraulic pump of the sub-transmission is connected to the main ECU, and a detection signal of the pump swash plate position sensor is input to the main ECU. The main ECU controls the sub-transmission based on information obtained from detection signals of a position sensor of a sub-shift lever and a pump swash plate position sensor.

In fig. 3, an electronically controlled servo motor is additionally provided in the HMT to change the swash plate inclination angle of the hydraulic pump. The servo motor drives the HMT pump swash plate to move towards the forward side from the counterclockwise rotation of the forward side and drives the HMT pump swash plate to move towards the backward side from the clockwise rotation of the backward side to change the angle of the pump swash plate. The servo motor, the counterclockwise rotation and the clockwise rotation constitute a servo mechanism for controlling the inclination angle of the swash plate of the hydraulic pump.

The HMT substantially includes an operation strategy, a target swash plate position calculation means, an actual swash plate position detection means, a deviation calculation means, and a PI (Proportional-Integral) calculation means as a processing means for HMT control. The processing means are implemented by means of program processing and software or by means of logic circuit hardware.

The operating strategy sets a deceleration rate corresponding to the load of the engine.

Specifically, information on the engine speed (hereinafter referred to as "engine speed") is input from the engine ECU to the HMTECU via the main ECU. The combine harvester is provided with an engine rotation sensor for outputting a pulse type synchronized with the rotation of the engine (crankshaft rotation) as a detection signal, and the engine rotation speed is determined from the sensor detection signal.

The operation strategy determines the reduction amount of the engine speed from the reference engine speed using the engine speed in the no-load state of the engine as the reference engine speed, and determines the ratio of the reduction amount to a predetermined reference reduction amount as the load factor (%). The operation strategy sets a deceleration rate corresponding to whether or not a load rate, which is a load corresponding value corresponding to the load of the engine, exceeds a reference value. More specifically, when the load factor exceeds 100% which is a reference value, the operation strategy sets a proportional term and an integral term in order to decelerate the traveling speed of the machine body, and the deceleration rate is set by adding the sum of the proportional term and the integral term to 1000(‰). The proportional term is set by multiplying the proportional gain by the deviation of the load rate from a reference value. The integral term is set by multiplying an integral gain by an integral value of a deviation of the load factor from a reference value.

The target swash plate position calculating means calculates a value corresponding to a target swash plate position of a pump swash plate of the hydraulic pump according to a predetermined calculation formula by taking a detection value obtained by digitizing a detection signal of a shift lever position sensor as a value corresponding to a position of a shift lever and multiplying a deceleration rate set by a driving strategy by the detection value. It should be noted that a map that specifies a relationship between a product obtained by multiplying the deceleration rate by the detection value of the shift lever position sensor and a value corresponding to the target swash plate position may be stored in the memory of the HMTECU, and the target swash plate position calculation strategy may set the value corresponding to the target swash plate position from the product according to the map.

The actual swash plate detection means converts a detection value obtained by digitizing a detection signal of the pump swash plate position sensor into a value corresponding to the actual swash plate position of the pump swash plate of the hydraulic pump.

The deviation calculating means calculates a swash plate position deviation as a deviation of the target swash plate position from the actual swash plate position by subtracting a value corresponding to the actual swash plate position calculated by the actual swash plate position detecting means from a value corresponding to the target swash plate position calculated by the target swash plate position calculating means.

The PI operation strategy calculates PI (proportional integral) of the swash plate position deviation, and sets the time for supplying the voltage of the servo motor to the servo motor in the clockwise and counterclockwise directions, respectively, based on the result of the PI operation.

In the HMTECU, a swash plate control strategy controls clockwise and counterclockwise rotations of the servo motor by changing the direction of voltage, i.e., acceleration control and deceleration control. The change of the angle of the control swash plate is determined by the time of voltage supplied to the servo motor.

By setting the deceleration rate to be less than 1000(‰), the value corresponding to the target swash plate position of the hydraulic pump is set to the minimum value when the deceleration rate is set to 1000 (% o). As a result, the amount of hydraulic oil discharged from the hydraulic pump decreases, the rotational speed of the hydraulic motor transmitted to the traveling device decreases, and the traveling speed of the machine body decreases. The load on the engine is reduced by reducing the traveling speed of the machine body. When the engine load factor decreases from a value exceeding 100% as a reference value to a value equal to or less than the reference value, the operation strategy sets an integral term by eliminating the proportional term set up so far as shown in fig. 3 in order to increase the travel speed of the engine body, and sets a deceleration rate by adding 1000(‰) to the integral term. In this case, the operation strategy sets an integral gain by adding the integral term to the deceleration rate of the vanishing proportional term, and multiplies the integral gain by the integral value of the deviation of the load factor from the reference value to set the integral term. This suppresses a sudden change in the deceleration rate when the traveling speed of the machine body is switched from deceleration to acceleration.

In fig. 4, an electronically controlled servo motor is additionally provided in a sub-transmission device (a mechanical transmission device, which can only change the flow rate of a fluid flowing into the transmission device and cannot change the flow direction of the fluid) in order to change the tilting angle of the sub-transmission device. The servo motor has the angle that the anticlockwise rotation from the advancing side drives the sub-transmission dial position to move towards the advancing side direction and the clockwise rotation from the retreating side drives the sub-transmission dial to move towards the retreating side direction to change the dial. A servo mechanism for controlling the tilt angle of a dial of the sub-transmission is configured by a servo motor, counterclockwise rotation, and clockwise rotation.

The sub-transmission is substantially provided with an operation strategy, a target dial position calculation means, an actual dial position detection means, a deviation calculation means, and a PI (Proportional-Integral) calculation means as a processing means for controlling the sub-transmission. The processing means are implemented by means of program processing and software or by means of logic circuit hardware.

The variator control principle of the subtransmission is the same as that of the HMT. However, the sub-transmission can only change the speed and cannot change the direction of the rotating speed. The variable speed control of the HMT can control the speed and the rotating speed direction.

The splitter control may be used alone or in combination with the HMT shift control.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. The automatic speed change control system of the harvester based on the motor drive comprises a machine body, a power-driven working device with an engine and a position detection mechanism, and is characterized in that the power-driven working device with the engine comprises a power-driven swash plate type pump with the engine and a fluid driving motor discharged by the pump, and a stepless speed change device for outputting the power of the motor;

2. The motor drive based harvester automatic transmission control system of claim 1, wherein the position detection mechanism comprises a shift lever position sensor, an HMT pump swash plate position sensor, and a mechanical transmission range dial position sensor.

3. The motor drive based harvester automatic transmission control system of claim 1, wherein the continuously variable transmission comprises an HMT continuously variable transmission.

4. The automatic variable speed control device of the harvester based on the motor drive as claimed in claim 1, characterized in that a cab (4) is arranged on the machine body, a grain unloading device (3) is arranged on the left side of the cab (4), a grain collecting granary (2) is arranged below the grain unloading device (3), a cleaning device (1) is arranged below the grain collecting granary (2), a grain conveying device (10) is arranged below the cab (4), a header lifting cylinder (16) is hinged to the bottom of the grain conveying device (10), a harvesting device (11) is arranged on the right side of the grain conveying device (10), a reel (12) is rotatably connected to the harvesting device (11), a reel transmission mechanism (13) is arranged on the front side of the harvesting device (11), a cutting knife (14) is arranged at the bottom of the right side of the harvesting device (11), and a header height monitoring mechanism (15) is arranged at the bottom of the front surface of the harvesting device (11).

5. The automatic speed change control device for the harvester driven by the motor as claimed in claim 4, wherein a seat (9) is arranged inside the cab (4), an operation table (6) is arranged on the front surface of the seat (9), a gear lever (8) is arranged on the operation table (6), a gear, a header and a reel operating handle (7) are arranged on the right side of the gear lever (8), and a direction machine (5) is arranged on the right side of the seat (9).

6. A harvester automatic variable speed control device based on motor drive according to claim 5, characterized in that the cleaning device (1) is provided with a plurality of wheels (17) at the bottom.