JP2019213502A - Working vehicle - Google Patents

Abstract

To provide a working vehicle preventing adjustment data not matching a positional relation between an object to be detected and a sensor from being used for controlling a servo mechanism.SOLUTION: An HST 31 is constituted so as to contain a servo mechanism 66 changing the position of a swash plate of a hydraulic pump 41. In a travel control ECU 83 controlling the servo mechanism 66, the adjustment data adjusting a detection value of a main shift lever sensor 85 are stored. On the other hand, the adjustment data are stored also in a main ECU 81 communicably connected to the travel control ECU 83. When the adjustment data stored in the travel control ECU 83 and the adjustment data stored in the main ECU 81 coincide with each other, the detection value of the main shift lever sensor 85 is adjusted using the coincident adjustment data, and the servo mechanism 66 is controlled on the basis of the adjusted detection value.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a work vehicle such as a harvester for harvesting cereals.

  For example, in a combine equipped with an HST (Hydro Static Transmission), a hydraulic pump of the HST is driven by engine power, and a hydraulic motor is driven by oil discharged from the hydraulic pump. Is transmitted to the left and right crawlers. When the left and right crawlers are driven at the same speed, the machine body goes straight back and forth, and when the left and right crawlers are driven with a speed difference, the machine body turns right and left.

  The driver's cab is provided with a shift lever that is displaceable forward and rearward from a neutral position. In a configuration employing an electronic control type (electronic servo type), a shift lever sensor that outputs a detection value according to the position of the shift lever is provided in association with the shift lever. The value detected by the shift lever sensor is input to an ECU (Electronic Control Unit). The HST is provided with a pump swash plate position sensor that outputs a detection value according to the position (angle) of the swash plate of the hydraulic pump, and the ECU receives the detection value of the pump swash plate position sensor. Is done.

  When the shift lever is operated forward or rearward from the neutral position, the ECU sets the target position of the swash plate of the hydraulic pump based on the value detected by the shift lever sensor. Then, the ECU controls the servo mechanism that changes the position of the swash plate based on the detection value of the pump swash plate position sensor so that the deviation between the target position and the actual position of the hydraulic pump swash plate approaches zero. Is done. By changing the position of the swash plate of the hydraulic pump, the discharge direction and flow rate of oil from the hydraulic pump change, and the rotation direction and rotation speed of the hydraulic motor change.

JP 2008-57358 A

  The shift lever sensor and the pump swash plate position sensor include, for example, a potentiometer that outputs a voltage corresponding to the amount of displacement of the detection target from the reference position. Therefore, due to a variation in assembling of the shift lever sensor and the pump swash plate position sensor, the detection value of the sensor when the detection target is located at the reference position deviates from the reference value corresponding to the reference position. Therefore, when the combine is shipped from the factory, adjustment data for adjusting the detection value of each sensor according to the positional relationship between the detection target and the sensor is stored in the ECU. In the control of the HST servo mechanism by the ECU, the adjustment data is stored. Data is used.

  However, if the memory storing the adjustment data breaks down or the ECU is replaced with the memory, the adjustment data that does not match the positional relationship between the sensor and the detection target is used for controlling the servo mechanism. In this case, there is a possibility that the HST makes a movement contrary to the intention of the operator who operates the shift lever.

  An object of the present invention is to provide a work vehicle that can suppress adjustment data that does not match the positional relationship between a detection target and a sensor from being used for controlling a servo mechanism.

  In order to achieve the above object, a work vehicle according to the present invention includes an engine, a pair of left and right traveling devices, a pump driven by the power of the engine, a motor driven by pressurized oil discharged from the pump, and a tilt of the pump. A power transmission device that includes a servo mechanism for changing the position of the plate and transmits the power of the motor to the traveling device, a detection target that is displaceably provided, and a sensor that outputs a detection value according to the position of the detection target. A first control unit that controls the servo mechanism; and a second control unit that is communicably connected to the first control unit. The first control unit and the second control unit detect a detection value of a sensor. Adjustment data for adjusting according to the positional relationship between the target object and the sensor is held, and the first control unit stores the adjustment data held by the first control unit and the adjustment data held by the second control unit. If they match, the matching Using adjustment data to adjust the detected values of the sensor, it controls the servo mechanism based on a detection value after the adjustment.

  According to this configuration, the power transmission device is interposed between the engine and the pair of left and right traveling devices. The power transmission device is configured to include a pump driven by the power of the engine, a motor driven by pressure oil discharged from the pump, and a servo mechanism for changing the position of a swash plate of the pump. The power of the motor is transmitted to the pair of left and right traveling devices.

  The first control unit that controls the servo mechanism holds adjustment data for adjusting the detection value of the sensor. On the other hand, the adjustment data is also held in the second control unit communicably connected to the first control unit. When the work vehicle is shipped from the factory, the same adjustment data is held in the first control unit and the second control unit. For example, when the first control unit or the second control unit is replaced after the factory shipment, the first control unit and the second control unit are replaced. The adjustment data stored in the control unit is different from the adjustment data stored in the second control unit. In this case, when the adjustment data held in the first control unit or the second control unit is used for controlling the servo mechanism, the adjustment data that does not match the positional relationship between the sensor and the detection target is used for controlling the servo mechanism. Therefore, there is a possibility that the power transmission device moves in a manner contrary to the intention of the worker using the work vehicle.

  Therefore, when the adjustment data held in the first control unit matches the adjustment data held in the second control unit, the detection value of the sensor is adjusted using the matching adjustment data, and the adjustment is performed. The servo mechanism is controlled based on the later detected value. Thus, it is possible to suppress the use of adjustment data that does not match the positional relationship between the sensor and the detection target for controlling the servo mechanism. As a result, it is possible to suppress the power transmission device from moving against the intention of the worker.

  If the adjustment data held by the first controller and the adjustment data held by the second controller are different, the start of the engine may be prohibited. Since the engine is not started, it is possible to prevent the power transmission device from moving against the intention of the operator.

  However, the work vehicle is provided with a receiving unit that receives an instruction for an emergency operation of the engine in a situation where the starting of the engine is prohibited, and in response to the instruction for the emergency operation of the engine being received by the receiving unit. Preferably, start-up for emergency operation of the engine is permitted. The emergency operation of the engine allows the work vehicle to run to a repair shop or the like by itself.

  The object to be detected by the sensor may be a shift operation member that is operated from the neutral position to one side to advance the work vehicle and is operated to the other side from the neutral position to reverse the work vehicle. In this case, during an emergency operation of the engine, the detection value of the sensor may be adjusted using default data different from the adjustment data. The default data is data for adjusting the detection value of the sensor by a fixed amount. For example, for a plurality of individuals of the work vehicle, a detection value of the sensor when the detection target is located at the reference position is obtained, and a difference between the detection value and the reference value of the sensor according to the reference position of the detection target is obtained. An average value of the amounts may be determined, and the average value may be used as default data. By adjusting the detection value of the sensor using the default data, the detection value of the sensor can be adjusted at an average level so that the movement of the power transmission device against the intention of the worker is suppressed.

  The work vehicle further includes a switch operation member that is switched between a first state and a second state, and the detection target is operated to one side from a neutral position for forward movement of the work vehicle, and A shift operating member that is operated from the neutral position to the other side. When the switch operating member is in the first state during an emergency operation of the engine, the swash plate of the pump is located at a fixed position in the forward direction, and the switch operating member is In the second state, the servo mechanism may be controlled such that the swash plate of the pump is located at a fixed position in the reverse direction. Thus, the work vehicle can be moved forward and backward by operating the switch operation member.

  When the detection target is the swash plate of the pump, the target position of the swash plate of the pump may be set during the emergency operation of the engine, and the feed-forward control of the servo mechanism may be performed.

  When the object to be detected is the pump swash plate, the pump swash plate is located at the neutral position when the engine is stopped before starting. The detection value of the sensor may be adjusted using default data different from the adjustment data as a value corresponding to the neutral position of the pump swash plate.

  The detection target object may be a steering member that is operated to one side from the neutral position for turning the work vehicle to the left and is operated to the other side from the neutral position for turning the work vehicle to the right. In that case, during an emergency operation of the engine, default data different from the adjustment data may be used for adjusting the detection value of the sensor. Thereby, as described above, the detection value of the sensor can be adjusted at an average level so that the movement of the power transmission device against the intention of the worker is suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the adjustment data which does not correspond to the positional relationship between a detection target object and a sensor are used for control of the servo mechanism of a power transmission device, and the power transmission device intends to use the work vehicle. It is possible to suppress a movement contrary to the above.

It is a right view which shows the front part of the combine which concerns on one Embodiment of this invention. It is a figure showing composition of HST carried in a combine. It is a block diagram which shows the principal part of the electrical structure of a combine. 5 is a flowchart illustrating a flow of a process executed for controlling the HST.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Combine>
FIG. 1 is a right side view showing a front part of a combine 1 according to an embodiment of the present invention.

  The combine 1 is a work vehicle that cuts culms and threshes from culms while traveling in a field. The fuselage 11 of the combine 1 is supported by a pair of right and left traveling devices 12. The traveling device 12 employs a crawler having a rough terrain running capability so that the combine 1 can travel in a field.

  The machine body 11 is provided with a cab 13, a reaper 14, a threshing device 15, and a grain tank 16.

  The cab 13 is arranged above the front end of the traveling device 12. The driver's cab 13 is provided with a driver seat 17 on which an operator sits. For example, an operation panel 18 operated by the operator is provided in front of and to the left of the driver seat 17. The operation panel 18 includes a main shift lever 21 and a steering lever 22.

  The main transmission lever 21 is provided so as to be tiltable in the front-rear direction. By tilting the main transmission lever 21, the forward and backward movements of the body 11 can be switched, and the speed of the forward or backward movement can be changed.

  The steering lever 22 is provided to be tiltable in the left-right direction and the front-back direction. By the tilting operation of the steering lever 22 in the left-right direction, the aircraft body 11 can be switched between straight traveling, left turning, and right turning. Further, the mowing device 14 can be moved up and down by tilting the steering lever 22 in the front-rear direction.

  The reaper 14 is arranged in front of the traveling device 12. The reaper 14 includes a weeding tool 23 at the front end thereof, and a cutting blade 24 behind the weeding tool 23. The weeding tool 23 and the cutting blade 24 are supported by the reaper frame 25F. At the rear end of the mowing device frame 25F, a horizontal cutting frame 25L extending in the left-right direction is provided. One end of the main cutting frame 25M is connected to the horizontal cutting frame 25L. The reaping main frame 25M extends rearward from the reaping horizontal frame 25L, and the other end (provided forward and downward, the rear end) is rotatably connected to the frame of the machine body 11. By the tilting operation of the steering lever 22 in the front-rear direction, the cylinder (not shown) can be operated to swing the reaping main frame 25M, and by the swinging, the weeding implement 23 and the cutting blade 24 are grounded. From above, and a descending position in which the weeding implement 23 and the cutting blade 24 descend near the ground. When the airframe 11 advances in a state where the weeding tool 23 and the cutting blade 24 are located at the lowered position, the grain culm is planted on the field while the culm is divided by the weeding tool 23, and the grain culm is cut by the cutting blade 24. Reaped by

  The threshing device 15 and the grain tank 16 are arranged side by side at a position above the traveling device 12 and behind the reaper 14. The cut culm is conveyed to the threshing device 15 by the cutting device 14. The threshing apparatus 15 conveys the stem side of the grain stalk backward by a threshing feed chain, and supplies the spike end side of the grain stalk to a handling room for threshing. Then, the grains are transported from the threshing device 15 to the grain tank 16, and the grains are stored in the grain tank 16. A grain discharge auger 26 is connected to the grain tank 16, and the grains stored in the grain tank 16 can be discharged outside the machine by the grain discharge auger 26.

<Continuously variable transmission>
FIG. 2 is a diagram showing a configuration of the HST 31.

  The combine 1 is equipped with an HST (Hydro Static Transmission: hydrostatic transmission) 31. The HST 31 shifts and outputs the power of the engine 32 (see FIG. 3). The power output from the HST 31 is transmitted to the left and right traveling devices 12 via a turning mechanism (not shown) as a turning mechanism, for example, including a plurality of hydraulic clutches, and engaging these clutches ( A state in which a constant-speed power is transmitted to the left and right traveling devices 12 by a combination of the (in) and a release (off), and a state in which lower-speed power is transmitted to one of the left and right traveling devices 12 to the other. And a state where power is transmitted to only one of the left and right traveling devices 12 and a state where power transmitted in the opposite direction to the power transmitted to one of the left and right traveling devices 12 is transmitted to the other is adopted. Is done. .

  The HST 31 has a closed circuit configuration in which the hydraulic pump 41 and the hydraulic motor 42 are connected by a first oil passage 43 and a second oil passage 44 so that hydraulic oil circulates between the hydraulic pump 41 and the hydraulic motor 42. Have. The first oil passage 43 is connected to a first port 45 of the hydraulic pump 41 and a first port 46 of the hydraulic motor 42. The second oil passage 44 is connected to a second port 47 of the hydraulic pump 41 and a second port 48 of the hydraulic motor 42.

  The HST 31 is provided with a charge pump 51. The charge pump 51 is a fixed displacement hydraulic pump, and discharges hydraulic oil to a charge oil passage 53 by rotation of a pump rotation shaft 52. The charge oil passage 53 is connected to the first oil passage 43 via a first check valve 54 and is connected to the second oil passage 44 via a second check valve 55. The charge oil passage 53 is connected to an oil tank 57 via a charge relief valve 56.

  By the function of the charge relief valve 56, the oil pressure in the charge oil passage 53 is maintained at a predetermined charge pressure. When the oil pressure in the first oil passage 43 becomes lower than the oil pressure in the charge oil passage 53, that is, the charge pressure, the first check valve 54 is opened, and the first oil passage 53 is connected to the first oil passage 53 via the first check valve 54. Hydraulic oil is supplied to 43. When the oil pressure in the second oil passage 44 becomes lower than the charge pressure, the second check valve 55 is opened, and hydraulic oil is supplied from the charge oil passage 53 to the second oil passage 44 via the second check valve 55. Is done. Thereby, the oil pressure of the first oil passage 43 and the second oil passage 44 is maintained at or above the charge pressure.

  The HST 31 is an integrated type in which a hydraulic pump 41, a hydraulic motor 42, a first oil passage 43, a second oil passage 44, a first check valve 54, a second check valve 55, a charge relief valve 56, and the like are housed in a single case. It is configured as HST.

  The hydraulic pump 41 is a variable displacement swash plate type piston pump, and includes a cylinder block, a plurality of pistons radially arranged in the cylinder block, a pump swash plate on which the piston slides, and the like. The hydraulic pump 41 and the charge pump 51 have a common pump rotation shaft 52, and the cylinder block is provided so as to rotate integrally with the pump rotation shaft 52.

  An electronically controlled servo cylinder 58 is provided to change the inclination angle of the pump swash plate of the hydraulic pump 41. The servo cylinder 58 has a first pressure chamber 62 to which a hydraulic pressure is supplied from a pressure control valve 61 on the forward side, and a second pressure chamber 64 to which a hydraulic pressure is supplied from a pressure control valve 63 on the reverse side. Further, the servo cylinder 58 has a rod 65 that moves linearly due to the pressure difference between the first pressure chamber 62 and the second pressure chamber 64, and the linear movement of the rod 65 changes the inclination angle of the pump swash plate. Is done. The servo cylinder 58, the pressure control valve 61 on the forward side, and the pressure control valve 63 on the reverse side constitute a servo mechanism 66 for controlling the inclination angle of the pump swash plate of the hydraulic pump 41.

  As the inclination angle of the pump swash plate with respect to the axis of the pump rotation shaft 52 of the hydraulic pump 41 (the rotation axis of the cylinder block) increases, the discharge amount of hydraulic oil from the hydraulic pump 41 decreases, and the inclination angle of the pump swash plate increases by 90 degrees. °, the discharge of the hydraulic oil from the hydraulic pump 41 stops. When the inclination angle of the pump swash plate exceeds 90 ° (when the inclination is reversed), the discharge direction of the hydraulic oil from the hydraulic pump 41 is reversed when the inclination angle is less than 90 °.

  The hydraulic motor 42 is a variable displacement type swash plate type piston motor, in which a motor rotating shaft 71, a cylinder block rotating integrally with the motor rotating shaft 71, a plurality of pistons and pistons radially arranged in the cylinder block are pressed. It has a motor swash plate and the like. When the inclination angle of the motor swash plate with respect to the axis of the motor rotation shaft 71 of the hydraulic motor 42 is constant, the larger the amount of hydraulic oil supplied to the hydraulic motor 42, that is, the larger the amount of hydraulic oil discharged from the hydraulic pump 41, As a result, the rotation speed of the motor rotation shaft 71 increases.

  When the amount of hydraulic oil supplied to the hydraulic motor 42 is constant, the rotation speed of the motor rotation shaft 71 decreases as the inclination angle of the motor swash plate increases. To change the inclination angle of the motor swash plate of the hydraulic motor 42, a sub-transmission piston 72 is provided. A low-speed switching valve 73 and a high-speed switching valve 74 are connected to the auxiliary transmission piston 72. The low-speed switching valve 73 is turned on, the high-speed switching valve 74 is turned off, and the hydraulic pressure is supplied from the low-speed switching valve 73 to the sub-transmission piston 72, so that the rod 75 of the sub-transmission piston 72 is located at the low-speed position. Thus, the inclination angle of the motor swash plate becomes relatively large. On the other hand, the low-speed switching valve 73 is turned off, the high-speed switching valve 74 is turned on, and the hydraulic pressure is supplied from the high-speed switching valve 74 to the sub-transmission piston 72, whereby the rod 75 of the sub-transmission piston 72 is moved to the high-speed position. And the inclination angle of the motor swash plate becomes relatively small. Therefore, by switching on / off of the low-speed switching valve 73 and the high-speed switching valve 74, the position of the motor swash plate is changed to a high-speed position where the rotation speed of the motor rotation shaft 71 becomes relatively large, and the rotation of the motor rotation shaft 71. It is possible to switch to two stages: a position on the low speed side where the number is relatively small.

<Electrical configuration>
FIG. 3 is a block diagram showing a main part of an electrical configuration of the combine 1.

  The combine 1 is equipped with a single main ECU (Electronic Control Unit) 81 for overall overall control and a plurality of ECUs for specific individual control. ECUs for individual specific control include, for example, an engine ECU 82 for controlling the engine 32 and a travel control ECU 83 for controlling the HST 31. The main ECU 81, the engine ECU 82, and the travel control ECU 83 are each configured to include a microcontroller unit (MCU: Micro Controller Unit).

  The main ECU 81 is communicably connected to individual ECUs for specific control, that is, an engine ECU 82 and a travel control ECU 83. Further, a meter panel 84 arranged on the operation panel 18 (see FIG. 1) of the cab 13 is connected to the main ECU 81 as a control target. The main ECU 81 controls various instruments and indicators provided on the meter panel 84 such as an odometer. For example, when an abnormality occurs in the combine 1, the main ECU 81 transmits information on the abnormality to the meter panel 84 and causes the display to display the details of the abnormality. The display is, for example, a liquid crystal display.

  The traveling control ECU 83 includes a main transmission lever sensor 85 that outputs a detection signal corresponding to the operation position of the main transmission lever 21 and a steering lever sensor 86 that outputs a detection signal corresponding to the operation position of the steering lever 22. Are connected, and their detection signals are input.

  A switch 87 provided on the operation panel 18 of the driver's cab 13, which is used for other than the traveling control and the turning control, is connected to the traveling control ECU 83, and a signal corresponding to the state of the switch 87 is connected to the traveling control ECU 83. Is entered. As an example of the switch 87, there can be mentioned a key depth switch for adjusting the length of the grain stalk entering the threshing device 15, that is, the saw depth. The saw depth switch may be, for example, a switch that selectively sets the saw depth to a first length (depth) and a second length (shallow) shorter than the first length. The switch 87 includes an emergency start switch that is operated to instruct an emergency start of the engine 32.

  The operation panel 18 is provided with a turning mode switch. The turning mode switch is a dial type switch for switching a mode of turning control between a soft turning mode, a brake turning mode and a spin turning mode, and has a movable range including a soft turning mode, a brake turning mode and a spin turning mode. , A soft position, a brake position, and a spin position respectively corresponding to are set. The turning mode switch has a knob that is pinched and rotated by the operator's finger, and the position is switched by turning the knob, and a signal corresponding to each position of the soft position, the brake position, and the spin position is output. Output.

  Further, the traveling control ECU 83 includes a current sensor 88 that outputs a detection signal corresponding to a value of a current supplied to each of the pressure control valves 61 and 63 included in the HST 31, and a pump swash plate of the hydraulic pump 41 included in the HST 31. Is connected to a pump swash plate position sensor 89 that outputs a detection signal corresponding to the position (inclination angle).

  The main ECU 81 receives information obtained from detection signals of various sensors by each ECU for individual specific control, and transmits commands and information required by each ECU for control to each ECU. For example, the main ECU 81 receives an engine start permission transmitted from the travel control ECU 83, and transmits a command to start the engine 32 to the engine ECU 82. The memory provided in the main ECU 81 stores detection values obtained from the detection signals of the main shift lever sensor 85, the steering lever sensor 86, and the pump swash plate position sensor 89 connected to the travel control ECU 83. Adjustment data for adjustment is held, and the main ECU 81 transmits the adjustment data to the travel control ECU 83.

  The traveling control ECU 83 includes information obtained from detection signals of the main transmission lever sensor 85, the steering lever sensor 86, the current sensor 88, and the pump swash plate position sensor 89, information obtained from a signal input from the switch 87, The engine 32, the pressure control valves 61 and 63 included in the HST 31, the low-speed switching valve 73, the high-speed switching valve 74, and the turning mechanism for controlling traveling and turning of the body 11 based on information input from the main ECU 81. A valve for switching engagement / disengagement of each clutch provided in the controller is controlled.

<HST control>
FIG. 4 is a flowchart showing a flow of processing executed for controlling the HST 31.

  For traveling control, traveling control ECU 83 determines whether or not adjustment data has been received from main ECU 81 (step S11). As described above, the adjustment data includes adjustment data for adjusting the detection value obtained from the detection signal of the main shift lever sensor 85 (hereinafter, referred to as “adjustment data of the main shift lever sensor 85”), and the pump. Adjustment data for adjusting the detection value obtained from the detection signal of the swash plate position sensor 89 (hereinafter, referred to as “adjustment data of the pump swash plate position sensor 89”) is included.

  When the combine 1 is shipped from the factory, the same adjustment data as the adjustment data stored in the memory of the main ECU 81 is stored in the memory provided in the travel control ECU 83. The travel control ECU 83 that has received the respective adjustment data from the main ECU 81 determines whether or not the received respective adjustment data matches the respective adjustment data stored in the memory of the travel control ECU 83 (step S12).

  If both the main ECU 81 and the traveling control ECU 83 have not been replaced since the factory shipment of the combine 1, the same adjustment data is held in the memory of the main ECU 81 and the memory of the traveling control ECU 83. Each adjustment data received by the ECU 83 matches each adjustment data stored in the memory of the travel control ECU 83 (YES in step S12). In this case, a signal for permitting the start of the engine 32 is transmitted from the traveling control ECU 83 to the main ECU 81 (step S13). After the start of the engine 32 is permitted, when an engine start switch provided on the operation panel 18 (see FIG. 1) is operated, a start command of the engine 32 is transmitted from the main ECU 81 to the engine ECU 82. In response to this, the engine ECU 82 starts the engine 32.

  The detection value of the main shift lever sensor 85 when the main shift lever 21 is located at the reference position is deviated from the reference value corresponding to the reference position due to a variation in assembly of the main shift lever sensor 85. The adjustment data is provided for adjusting the detection value of the main shift lever sensor 85 in accordance with the positional relationship between the main shift lever 21 and the main shift lever sensor 85. The travel control ECU 83 uses the adjustment data of the main shift lever sensor 85 to adjust the detection value obtained from the detection signal of the main shift lever sensor 85. , "The adjusted main transmission lever detection value"), the pressure control valves 61, 63 of the HST 31 are controlled (step S14).

  Due to a variation in the assembly of the pump swash plate position sensor 89, the detection value of the pump swash plate position sensor 89 when the pump swash plate of the hydraulic pump 41 is located at the reference position deviates from the reference value corresponding to the reference position. The adjustment data of the swash plate position sensor 89 is provided to adjust the detection value of the pump swash plate position sensor 89 in accordance with the positional relationship between the pump swash plate and the pump swash plate position sensor 89. The travel control ECU 83 adjusts the detection value obtained from the detection signal of the pump swash plate position sensor 89 using the adjustment data of the pump swash plate position sensor 89, and detects the adjusted detection value for travel control. The pressure control valves 61 and 63 of the HST 31 are controlled based on the “adjusted pump swash plate detection value” (step S14).

  In the traveling control by the normal method, specifically, when the detected value of the main shift lever after adjustment is a value indicating the stop position of the main shift lever 21, the forward pressure control valve 61 and the reverse pressure control valve 61 of the HST 31 are used. By controlling the current supplied to 63, their respective opening degrees are adjusted, and the position of the pump swash plate of hydraulic pump 41 is set to a position at an inclination angle of 90 °. As a result, the hydraulic oil is not discharged from the hydraulic pump 41, so that the hydraulic motor 42 does not rotate and no power is output from the HST 31. Therefore, the traveling device 12 does not operate and the body 11 is stopped.

  When the main shift lever 21 is tilted forward from the stop position, for example, a target swash plate that is a target of the position of the pump swash plate of the hydraulic pump 41 according to the adjusted main shift lever detection value according to a predetermined calculation formula. A value indicating a position (a position at an inclination angle of less than 90 °) is set. A map defining the relationship between the detected value of the main shift lever and a value indicating the target swash plate position is stored in the memory of the travel control ECU 83, and the target swash plate corresponding to the position of the main shift lever 21 is stored in accordance with the map. A value indicating the position may be set.

  Then, the current supplied to the pressure control valves 61 and 63 is feedback-controlled according to the deviation between the value indicating the target swash plate position of the HST 31 and the adjusted pump swash plate detection value. Accordingly, the hydraulic pressure supplied from the forward pressure control valve 61 to the first pressure chamber 62 of the servo cylinder 58 becomes larger than the hydraulic pressure supplied from the reverse pressure control valve 63 to the second pressure chamber 64, Due to the pressure difference between the first pressure chamber 62 and the second pressure chamber 64, the position of the pump swash plate of the hydraulic pump 41 becomes a position where the inclination angle is less than 90 °. As a result, hydraulic oil is discharged from the hydraulic pump 41, the hydraulic motor 42 receives the hydraulic oil, rotates, and the HST 31 outputs power in the forward direction. At this time, if the state of the turning mechanism is a state of transmitting constant-speed power to the left and right traveling devices 12, the left and right traveling devices 12 rotate at a constant speed in the forward direction, so that the body 11 goes straight forward. .

  When the main shift lever 21 is tilted rearward from the stop position, the target swash plate position of the hydraulic pump 41 (inclination angle 90) corresponding to the adjusted main shift lever detection value is determined in the same manner as when tilted forward. (A position larger than °).

  Then, the current supplied to the pressure control valves 61 and 63 is feedback-controlled according to the deviation between the value indicating the target swash plate position of the HST 31 and the adjusted pump swash plate detection value. Thereby, the hydraulic pressure supplied from the reverse pressure control valve 63 to the second pressure chamber 64 of the servo cylinder 58 becomes larger than the hydraulic pressure supplied from the forward pressure control valve 61 to the first pressure chamber 62, Due to the pressure difference between the first pressure chamber 62 and the second pressure chamber 64, the position of the pump swash plate of the hydraulic pump 41 becomes a position larger than the inclination angle of 90 °. As a result, the hydraulic oil is discharged from the hydraulic pump 41 in the direction opposite to the forward direction, the hydraulic motor 42 receives the hydraulic oil, rotates in the direction opposite to the forward direction, and the HST 31 outputs the power in the reverse direction. At this time, if the state of the turning mechanism is a state in which constant-speed power is transmitted to the left and right traveling devices 12, the backward power output from the HST 31 is transmitted to the traveling device 12, and the left and right traveling devices 12 are transmitted. Rotates at a constant speed in the reverse direction, so that the body 11 moves straight backward.

  When the low speed switching valve 73 and the high speed switching valve 74 are turned on / off during forward or reverse travel, the high speed stage in which the rotation speed of the hydraulic motor 42 is relatively large and the low speed stage in which the rotation speed is relatively small are reduced. Can be switched to tiers. Therefore, the forward and backward speeds of the body 11 can be changed by switching between the high gear and the low gear. Note that an auxiliary shift lever (not shown) may be provided on the operation panel 18 of the driver's cab 13, and the operation of the auxiliary shift lever may be used to instruct switching between a high speed stage and a low speed stage.

  On the other hand, when the main ECU 81 is replaced after the combine 1 is shipped from the factory, the travel control ECU 83 does not receive each adjustment data from the main ECU 81 (NO in step S11), or Although the data is received, the received adjustment data does not match the adjustment data stored in the memory of the travel control ECU 83. In such a case (NO in step S12), a signal prohibiting the start of the engine 32 is transmitted from the traveling control ECU 83 to the main ECU 81 (step S15).

  Thereafter, the travel control ECU 83 determines whether or not an emergency start instruction has been input, for example, by operating an emergency start switch arranged on the operation panel 18 (see FIG. 1) (step S16). Then, when an emergency start instruction is input to the travel control ECU 83, a signal allowing the start of the engine 32 for emergency operation is transmitted from the travel control ECU 83 to the main ECU 81 (step S17). In response to this, a start command for the engine 32 is transmitted from the main ECU 81 to the engine ECU 82, and the engine 32 is started by the engine ECU 82.

  Then, the traveling control ECU 83 executes traveling control by a degeneration method different from the normal method (step S18). In the memory of the travel control ECU 83, apart from the adjustment data, default data for adjusting the detection value obtained from the detection signal of the main shift lever sensor 85 by a certain amount is held. For example, a detection value of the main shift lever sensor 85 when the main shift lever 21 is at the reference position is acquired for a plurality of individuals of the combine 1 and a main value corresponding to the detected value and the reference position of the main shift lever 21 is obtained. The average value of the shift amount from the reference value of the shift lever sensor 85 is obtained, and the average value is stored in the memory of the travel control ECU 83 as default data. In the running control using the degeneration method, the detection value obtained from the detection signal of the main shift lever sensor 85 is adjusted using the default data.

  Then, a value indicating the target swash plate position of the hydraulic pump 41 is set according to the detected value after the adjustment based on the default data. The current supplied to the pressure control valves 61 and 63 is feedforward controlled based on the value indicating the target swash plate position of the HST 31. That is, the target value of the current supplied to the pressure control valves 61 and 63 is set according to the value indicating the target swash plate position of the HST 31, and the current of the target value is supplied to the pressure control valves 61 and 63.

<Effect>
As described above, the HST 31 is interposed between the engine 32 and the pair of left and right traveling devices 12. The HST 31 includes a hydraulic pump 41 driven by the power of the engine 32, a hydraulic motor 42 driven by pressure oil discharged from the hydraulic pump 41, and a servo mechanism 66 for changing the position of a swash plate of the hydraulic pump 41. . The power of the hydraulic motor 42 is transmitted to the pair of left and right traveling devices 12.

  The travel control ECU 83 that controls the servo mechanism 66 holds adjustment data for adjusting the detection value of the main shift lever sensor 85. On the other hand, the adjustment data is also held in the main ECU 81 communicably connected to the travel control ECU 83. When the combine 1 is shipped from the factory, the traveling control ECU 83 and the main ECU 81 hold the same adjustment data. For example, when the main ECU 81 is replaced after the combine 1 is shipped from the factory, the adjustment data held in the travel control ECU 83 is stored. The data is different from the adjustment data stored in the main ECU 81. In this case, when the adjustment data held in the travel control ECU 83 or the main ECU 81 is used for controlling the servo mechanism 66, the adjustment data that does not match the positional relationship between the main shift lever sensor 85 and the main shift lever 21 is output. , There is a possibility that the HST 31 may move against the intention of the operator who uses the combine 1.

  Therefore, when the adjustment data held in the traveling control ECU 83 and the adjustment data held in the main ECU 81 match, the detection value of the main shift lever sensor 85 is adjusted using the matching adjustment data, and The servo mechanism 66 is controlled based on the adjusted detection value. Thus, it is possible to prevent the adjustment data that does not match the positional relationship between the main shift lever sensor 85 and the main shift lever 21 from being used for controlling the servo mechanism 66. As a result, it is possible to suppress the HST 31 from moving against the intention of the worker.

  If the adjustment data held by the travel control ECU 83 is different from the adjustment data held by the main ECU 81 (including a case where the travel control ECU 83 does not receive the adjustment data from the main ECU 81), the start of the engine 32 is prohibited. . By not starting the engine 32, it is possible to prevent the HST 31 from moving against the intention of the operator.

  However, the switch 87 provided on the operation panel 18 is provided with an emergency start switch, and in response to receiving an instruction to start the engine 32 by operating the emergency start switch, the emergency of the engine 32 is stopped. Preferably, starting for operation is permitted. The emergency operation of the engine 32 allows the combine 1 to travel to a repair shop or the like by itself.

  The main shift lever 21 of the main shift lever sensor 85 is operated from the neutral position to one side to advance the combine 1, and is operated from the neutral position to the other side to reverse the combine 1. During an emergency operation of the engine 32, the detection value of the main shift lever sensor 85 is adjusted using default data different from the adjustment data. Thereby, the detection value of the main shift lever sensor 85 can be adjusted at an average level so that the movement of the HST 31 against the intention of the worker is suppressed. Then, a value indicating the target swash plate position of the hydraulic pump 41 is set according to the detected value after the adjustment based on the default data. Based on this, the current supplied to the pressure control valves 61 and 63 is controlled by feedforward control. By doing so, the combine 1 can be moved forward and backward.

<Modification>
As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented in another form.

  For example, in the above-described embodiment, when each of the adjustment data received by the travel control ECU 83 from the main ECU 81 and each of the adjustment data held in the memory of the travel control ECU 83 do not match, the travel control by the degeneration method is executed, The detection value of the main transmission lever sensor 85 is adjusted using default data different from the adjustment data, and the current supplied to the pressure control valves 61 and 63 is fed forward based on the detection value after adjustment based on the default data. Controlled. However, the current supplied to the pressure control valves 61 and 63 may be feedforward controlled even in running control using the degeneration method.

  That is, when the engine 32 is stopped before starting, the pump swash plate position sensor 89 of the hydraulic pump 41 is located at the neutral position before the emergency start of the engine 32. It can be regarded as a value corresponding to the position. Therefore, in the memory of the travel control ECU 83, for example, an intermediate value of the detection value obtained from the detection signal of the pump swash plate position sensor 89 is held as default data, and the default data and the pump value before the emergency start of the engine 32 are stored. The detection value of the pump swash plate position sensor 89 can be adjusted using the deviation from the detection value of the swash plate position sensor 89. Then, the current supplied to the pressure control valves 61 and 63 can be feedback-controlled according to the deviation between the value indicating the target swash plate position and the adjusted pump swash plate detection value.

  If the respective adjustment data received by the travel control ECU 83 from the main ECU 81 and the respective adjustment data held in the memory of the travel control ECU 83 do not match, for example, information indicating that fact is transmitted from the travel control ECU 83 to the main ECU 81. Then, under the control of the main ECU 81, a display indicating that the switch 87, for example, the saw depth switch is used to instruct the fuselage 11 to move forward or backward may be displayed on the display of the meter panel 84. When the saw depth switch for setting the saw depth to the first length is on, the target swash plate position of the pump swash plate of the hydraulic pump 41 is set to a constant position on the forward side, and the saw depth is set to the first depth. When the key depth switch set to 2 lengths is on, the target swash plate position is set to a constant position on the reverse side, and the current supplied to the pressure control valves 61 and 63 is subjected to feedforward control or feedback control. Good to be.

  In addition, in each memory of the main ECU 81 and the travel control ECU 83, adjustment data for adjusting a detection value obtained from a detection signal of the steering lever sensor 86 (hereinafter, referred to as “adjustment data of the steering lever sensor 86”). ) May be held. The detection value of the steering lever sensor 86 when the steering lever 22 is located at the reference position is deviated from the reference value corresponding to the reference position due to a variation in the assembly of the steering lever sensor 86. The adjustment data may be provided to adjust the detection value of the steering lever sensor 86 according to the positional relationship between the steering lever 22 and the steering lever sensor 86. The travel control ECU 83 uses the adjustment data of the steering lever sensor 86 to adjust the detection value obtained from the detection signal of the steering lever sensor 86, and adjusts the detection value after the adjustment for steering control. Based on this, the pressure control valves 61 and 63 of the HST 31 may be controlled.

  In the above-described embodiment, the combine 1 is taken up as an example of the work vehicle. However, the present invention is not limited to the combine 1 but may be a harvester that harvests vegetables such as carrots, radish, green soybeans, and cabbage. It can be applied to the amount of workers.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1: Combine (work vehicle)
12: Traveling device 21: Main transmission lever 22: Steering lever 31: HST (power transmission device)
32: Engine 41: Hydraulic pump (pump)
42: Hydraulic motor (motor)
66: Servo mechanism 81: Main ECU (second control unit)
83: Travel control ECU (first control unit)
85: Main transmission lever sensor (sensor)
86: Steering lever sensor (sensor)
87: switch (switch operating member)
89: Pump swash plate position sensor (sensor)

Claims (8)

Engine,
A pair of left and right traveling devices,
A pump driven by the power of the engine, a motor driven by pressure oil discharged from the pump, and a servo mechanism for changing a position of a swash plate of the pump; and a power for transmitting the power of the motor to the traveling device. A transmission device;
A detection object provided so as to be displaceable;
A sensor that outputs a detection value according to the position of the detection target,
A first control unit that controls the servo mechanism;
A second control unit communicably connected to the first control unit,
The first control unit and the second control unit hold adjustment data for adjusting a detection value of the sensor according to a positional relationship between the detection target and the sensor,
When the adjustment data held by the first control unit matches the adjustment data held by the second control unit, the first control unit uses the matching adjustment data to change the detection value of the sensor. A work vehicle that adjusts and controls the servo mechanism based on a detected value after the adjustment.   2. The work according to claim 1, wherein the first control unit prohibits the start of the engine when the adjustment data held by the first control unit is different from the adjustment data held by the second control unit. 3. vehicle. A receiving unit that receives an instruction for emergency operation of the engine in a situation where the start of the engine is prohibited by the first control unit;
3. The work vehicle according to claim 2, wherein the first control unit permits starting of the engine for emergency operation in response to the instruction for emergency operation of the engine being received by the reception unit. 4. The detection target is a shift operation member that is operated to one side from a neutral position for forward movement of the work vehicle, and is operated to the other side from the neutral position for backward movement of the work vehicle,
The work vehicle according to claim 3, wherein the first control unit uses default data held separately from the adjustment data by the first control unit when adjusting the detection value of the sensor during an emergency operation of the engine. A switch operation member that can be switched between the first state and the second state;
The detection target is a shift operation member that is operated to one side from a neutral position for forward movement of the work vehicle, and is operated to the other side from the neutral position for backward movement of the work vehicle,
When the switch operating member is in the first state during the emergency operation of the engine, the first control unit is configured such that the swash plate of the pump is located at a fixed position in the forward direction, and the switch operating member is in the second position. 4. The work vehicle according to claim 3, wherein when in the state, the servo mechanism is controlled such that the swash plate of the pump is located at a fixed position in a reverse direction. 5. The detection target is a swash plate of the pump,
4. The work vehicle according to claim 3, wherein the first control unit sets a target position of the swash plate of the pump and performs feedforward control of the servo mechanism during an emergency operation of the engine. 5. The detection target is a swash plate of the pump,
The first control unit sets the detection value of the sensor before the start for the emergency operation of the engine as a value corresponding to the neutral position of the swash plate of the pump during the emergency operation of the engine. The work vehicle according to claim 3, wherein the control unit adjusts the detection value of the sensor using default data held separately from the adjustment data. The detection object is a steering member that is operated to one side from a neutral position for the left turn of the work vehicle, and is operated to the other side from the neutral position for a right turn of the work vehicle,
The work vehicle according to claim 3, wherein the first control unit uses default data held separately from the adjustment data by the first control unit when adjusting the detection value of the sensor during an emergency operation of the engine.

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