JP7754153B2 - Work vehicles - Google Patents

Description

The present invention relates to a work vehicle.

Conventionally, a continuously variable transmission equipped with a hydraulic motor that uses driving force from the engine to operate a variable pump and change the direction and amount of hydraulic oil sent to change the direction of travel and driving output is used. This configuration allows for increasing/decreasing travel speed, stopping, and switching between forward and reverse travel, and is well known (Patent Document 1).

Japanese Patent Application Laid-Open No. 2022-156439

In the above-mentioned known example, power is transmitted from a single continuously variable transmission to the left and right traveling crawlers, so it is necessary to provide a brake device with strong braking force on each side to slow down the traveling crawler on the inside of the turn when turning, which causes the structure to become complicated and large.
Furthermore, since no braking force is generally applied when the robot is traveling straight ahead, differences in the drive speed of the left and right crawlers occur, and as this difference accumulates, the direction of travel can gradually shift to the left or right, resulting in problems such as overlapping work positions, reduced work efficiency, and unused positions, which require time and effort for extra work.
The present application provides a traveling device with excellent straight-line stability by devising a transmission configuration.

The invention of claim 1 is a work vehicle equipped with left and right traveling devices 2 that travel in a field, a ground work device 4 that performs ground work, a continuously variable transmission (HST) 20 that changes the traveling speed and direction of travel (forward/reverse movement, left and right turning), and a travel operation lever 21 that operates the continuously variable transmissions 20, in which a pair of continuously variable transmissions 20 that transmit power to the traveling devices 2 are arranged on the left and right, and braking mechanisms 23 are provided that apply braking to each of the drive shafts 22 of the left and right continuously variable transmissions 20, and the braking force of the braking mechanisms 23 is set to be lower than the turning force that turns the vehicle body.
The invention of claim 2 is the work vehicle described in claim 1, characterized in that a rotation sensor 25 is provided to detect the rotation speed of the axles 24 of the left and right traveling devices 2, a lever potentiometer 26 is provided to detect the forward and backward operation amount of the traveling operation lever 21, and a swing sensor 27 is provided to detect the left and right operation of the work operation lever 19, and when the detection value of the lever potentiometer 26 is in the low speed range, the swing sensor 27 detects a first operation amount, or when the detection value of the lever potentiometer 26 is in the low speed range or higher, the swing sensor 27 detects less than the first operation amount and more than the second operation amount, or when the swing sensor 27 is in an undetected state and the rotational difference between the left and right traveling speeds is equal to or greater than a certain level.
In the invention of claim 3, the braking mechanism 23 is configured to be able to vary the braking force, and when the detection value of the lever potentiometer 26 is in the low speed range, the braking force is set to ``weak,'' and when the speed is above the low speed range, the braking force is set to ``strong,'' and the above braking force is configured to change within each range depending on whether the detection value of the lever potentiometer 26 increases or decreases, resulting in a work vehicle as described in claim 2.
The invention of claim 4 is a work vehicle described in any one of claims 1 to 3, characterized in that a storage device (grain tank) 5 is provided for storing recovered material (grain) supplied from the ground work device 4, a capacity sensor (weight or area sensor) 32 is provided in the storage device 5, and the braking force of the braking mechanism 23 is increased as the amount of recovered material stored detected by the capacity sensor 32 increases.
In the invention of claim 5, a heat detection sensor (thermal camera) 33 that detects (identifies) the temperature of the operator is provided in the control unit 6 that controls the vehicle, and when the key on the control unit 6 is turned on, the heat detection sensor 33 does not detect a temperature above a predetermined value at a position that can be considered to be the recorded worker, so that the drive source (engine/motor) 36 will not be started, and when the heat detection sensor 33 does not detect the operator (the operator has dismounted), the drive transmission of the drive source 36 to the traveling device 2 and work device is cut off (clutch disengaged or the continuously variable transmission 20 is put into neutral), making it a work vehicle as described in any one of claims 1 to 3.
In the invention of claim 6, a temperature-adjusting seat air conditioner 38 is provided to adjust the temperature of the driver's seat 34 provided in the control unit 6, and the temperature of the seat air conditioner 38 is adjusted according to the driver's body temperature (body surface temperature) detected by the heat detection sensor 33, and when the body temperature detected by the heat detection sensor 33 is below a predetermined value (e.g., below 36 degrees), an alert is issued that the outside air temperature is low and will affect the start of the drive source 36, etc., in the work vehicle described in claim 5.

In the invention of claim 1, a pair of continuously variable transmissions 20 that transmit power to the traveling device 2 are arranged on the left and right, and a braking mechanism 23 is provided to apply a brake to each of the drive shafts (output shafts) 22 of the left and right continuously variable transmissions 20, and the braking force of the braking mechanism 23 is set to be lower than the turning force that turns the vehicle body.Therefore, even when traveling straight, if a rotational difference (speed difference) occurs in the rotation of one of the left and right axles 24, the braking force is applied to the drive shaft 22 of the continuously variable transmission 20 by the braking mechanism 23, and the variation in the rotational speed of the left and right axles 24 is corrected.
Furthermore, since the braking force of the braking mechanism 23 is set to be weaker than the turning force that turns the machine body, even if a speed difference occurs between the left and right axles 24 when the machine body turns, the braking mechanism 23 is put into an inactive state, and the machine body can be turned smoothly without generating unnecessary energy loss due to braking.
Furthermore, a pair of left and right continuously variable transmissions 20 are arranged, but clutches and brakes are provided to turn on and off the rotation transmitted to the left and right axles as in the past, and speed changes and turning can be performed without complex gear switching, so the traveling transmission system can be simplified.
In the invention of claim 2, a rotation sensor 25 is provided to detect the rotation speed of the axle 24 of the left and right traveling devices 2, a lever potentiometer 26 is provided to detect the forward and backward operation amount of the traveling operation lever 21 (= forward/backward movement and speed change operation), and a turning sensor 27 is provided to detect the left and right operation of the work operation lever 19 (left and right turning operation), and when the detection value of the lever potentiometer 26 is in the low speed range (= small operation angle), the turning sensor 27 detects the first operation amount, or when the detection value of the lever potentiometer 26 is in the range of the low speed range or higher. When the turning sensor 27 detects an amount of operation less than the first amount and equal to or greater than the second amount of operation (micro-operation), or when the turning sensor 27 is in an undetected state and the rotational difference between the left and right running speeds is equal to or greater than a certain level, the braking mechanism 23 is released.Therefore, during low-speed running (usually assumed to be during mowing work), the braking mechanism 23 is not released until the work operation lever 19 is sufficiently operated in the turning direction, thereby preventing a speed difference from occurring between the left and right running devices 2 at an unintended timing and maintaining straight-line running ability.
When traveling at a low speed or higher (assuming traveling within a field or traveling on a road), the braking mechanism 23 is released by slightly moving the work operation lever 19 left or right, so that turning can be started immediately when turning, and the machine's response to operation is improved.
If a difference in travel speed between the left and right sides exceeds a predetermined value when the work operation lever 19 is not being turned, the braking mechanism 23 is released, thereby preventing damage to the brake mechanism in the event of an abnormality.
In the invention of claim 3, the braking mechanism 23 is configured to be able to vary the braking force, so that when the detection value of the lever potentiometer 26 is in the low speed range, the braking force is set to "weak," and when the speed is above the low speed range, the braking force is set to "strong." The braking force is configured to change within each range depending on whether the detection value of the lever potentiometer 26 increases or decreases. Therefore, by setting the strength of the braking force in accordance with the operation of the travel speed of the travel control lever 21, it is possible to prevent the course from being disturbed when traveling straight ahead even at high travel speeds, and since the braking mechanism 23 changes quickly when a turning operation is performed, the load on the braking mechanism 23 can be reduced.
The braking force is changed finely by a configuration in which the strength is changed when the running speed setting is changed, thereby improving cornering performance.
In the invention of claim 4, a storage device (grain tank) 5 is provided to store the collected material (grain) supplied from the ground work device 4, and a capacity sensor (weight or area sensor) 32 is provided in the storage device 5, and the braking force of the braking mechanism 23 is increased as the amount of collected material stored detected by the capacity sensor 32 increases.Therefore, even if the weight balance of the machine body in the left-right direction changes due to the stored collected material, the stronger braking force suppresses deviation in the direction of travel of the machine body, thereby improving operability.
In the invention of claim 5, a heat detection sensor (thermal camera) 33 that detects (identifies) the temperature of the operator is provided in the control unit 6 that controls the vehicle, and when the key on the control unit 6 is turned on, the heat detection sensor 33 does not detect a temperature above a predetermined value at a position that can be considered to be the recorded operator, so the drive source (engine/motor) 36 will not be started.When the heat detection sensor 33 does not detect the operator (the operator has dismounted), the drive transmission of the drive source 36 to the traveling device 2 and work device is cut off (the clutch is disengaged or the continuously variable transmission 20 is neutralized).Therefore, unless the operator is in a boarding position at the control unit 6, the drive source 36 will not start even if the key is operated, thereby ensuring the safety of the operator at start-up.
In the invention of claim 6, a temperature regulator 38 is provided to regulate the temperature of the driver's seat 34 provided in the control unit 6, and the temperature of the temperature regulator 38 is adjusted according to the body temperature (body surface temperature) of the operator detected by the heat detection sensor 33. When the body temperature detected by the heat detection sensor 33 is below a predetermined value (e.g., below 36 degrees), an alert is issued that the outside air is low and may affect the start-up of the drive source 36, etc. Since the temperature of the temperature regulator 38 is adjusted according to the operator's body temperature, the operator can maintain an appropriate temperature while concentrating on his work, thereby improving work efficiency.
Furthermore, by issuing a warning when it is determined that the environment is low temperature based on the operator's body temperature, it is possible to prompt the operator to warm up the engine, so that the engine can be operated without putting a load on it even in a low temperature environment.

FIG. Same plan view. Schematic diagram of the transmission path of the running gear. FIG. FIG. Plan view of the control section. FIG. FIG. Rear view of a work vehicle (combine). FIG. Plan view of the same part.

An embodiment of the present invention will be explained with reference to the drawings, with reference to 1 a machine frame (vehicle body frame), 2 a traveling device that travels in a field and is provided below the machine frame 1, 3 a sorting device (threshing device) provided above the machine frame 1, a ground work device 4 that performs ground work to process crops is provided in front of the traveling device 2, and a storage device (storage tank/grain tank) 5 that stores the crops processed by the ground work device 4. 6 is a control unit.
In explaining the present invention, for ease of understanding, directions such as front/rear, left/right, and up/down will be described based on the traveling direction of the work vehicle, but the configuration of the present invention is not limited to these. The traveling device 2 is configured to have a pair of left and right traveling crawlers 10. The traveling crawler 10 is configured by wrapping around the outer periphery of multiple rollers 15 provided between a driving rotor (driving wheel) 12 provided on the front side of a traveling frame (crawler frame/roller frame) 11 and a pressure adjusting rotor (idler wheel/tension roller) 13 provided on the rear side.

That is, in a work vehicle equipped with left and right traveling devices 2 that travel in a field, a ground work device 4 that performs ground work, a continuously variable transmission (HST) 20 that changes the traveling speed and direction of travel (forward/reverse movement, left and right turning), and a traveling operation lever 21 that operates the continuously variable transmissions 20, a pair of continuously variable transmissions 20 that transmit power to the traveling devices 2 are arranged on the left and right, and braking mechanisms 23 that apply braking to each of the drive shafts (output shafts) 22 of the left and right continuously variable transmissions 20 are provided, and the braking force of the braking mechanisms 23 is set to be lower than the turning force that turns the vehicle body.
Basically, when the travel control lever 21 is operated to move forward, the left and right continuously variable transmissions 20 output the same rotation speed to the left and right traveling crawlers 10, and when the work control lever 19 is tilted to either the left or right, the machine body turns. This turning configuration is arbitrary, but as one example, a gentle turn is made by increasing (or decreasing) the speed of one of the left and right continuously variable transmissions 20, a sharp turn is made by increasing the speed of one of the left and right continuously variable transmissions 20 and decreasing the speed of the other, and a turn in which direction is changed on the spot, known as a spin turn, can be made by rotating one of the left and right continuously variable transmissions 20 forward and the other continuously variable transmission 20 backward.

In this case, when the vehicle is operated to travel in a straight line, the left and right continuously variable transmissions 20 output the same output rotation to the axles 24 of the drive rotors 12, but the rotation speeds of the left and right axles 24 may differ due to running resistance, etc., which may cause the vehicle's running direction to shift slightly left or right, resulting in a lack of straight-line stability.
Therefore, even when traveling straight, if a difference in rotation (speed difference) occurs in the rotation of one of the left and right axles 24, a braking force is applied to the drive shaft 22 of the continuously variable transmission 20 by the braking mechanism 23, thereby correcting the difference in the rotation speeds of the left and right axles 24.
The braking force of the braking mechanism 23 is set to be weaker than the turning force that turns the vehicle, and turning is made possible by comprehensively determining the speed difference between the left and right axles 24 and the direction of travel.
That is, in conventional traveling devices, the rotation of one of the left and right axles 24 inside the transmission case is braked to turn the vehicle, but to distinguish from this application of braking force, a braking force is applied to one of the axles 24 in order to correct the difference in rotation between the left and right axles 24, and to distinguish this from the braking force for turning, it is expressed as "the braking force of the brake application mechanism 23 is a force lower than the turning force for turning the vehicle."

Therefore, even if the braking mechanism 23 applies a braking force to the rotation shaft 24, the aircraft will not turn, and rather, its straight-line running ability will be improved.
In other words, when it is determined that the aircraft is turning, braking by the braking mechanism 23 is not performed.
Therefore, by changing the drive speed of the left and right traveling devices 2 by changing the output of the left and right continuously variable transmissions 20, speed changes and turning can be performed without switching gears in a complicated manner as in the past, and the traveling transmission system can be simplified.
A braking mechanism 23 is provided between the left and right sides of the continuously variable transmission 20, so that even if a difference in drive speed occurs between the left and right traveling crawlers 10 during straight traveling, the braking mechanism 23 decelerates the high-speed side, so that the traveling direction can be kept straight.

Furthermore, since the braking force is not so great as to impede cornering, cornering becomes smooth.
A rotation sensor 25 is provided to detect the rotation speed of the axle 24 of the left and right traveling devices 2, a lever potentiometer 26 is provided to detect the forward and backward operation amount of the traveling operation lever 21 (= forward/backward movement and gear change operation), and a turning sensor 27 is provided to detect the left and right operation of the work operation lever 19 (left and right turning operation), and when the detection value of the lever potentiometer 26 is in the low speed range (= small operation angle), the turning sensor 27 detects the first operation amount, or when the detection value of the lever potentiometer 26 is in the range above the low speed range, When the turning sensor 27 detects an amount of operation less than the first amount and equal to or greater than the second amount of operation (micro-operation), or when the turning sensor 27 is in an undetected state and the rotational difference between the left and right running speeds is equal to or greater than a certain level, the braking mechanism 23 is released.Therefore, during low-speed running (usually assumed to be during mowing work), the braking mechanism 23 is not released until the work operation lever 19 is sufficiently operated in the turning direction, thereby preventing a speed difference from occurring between the left and right running devices 2 at an unintended timing and maintaining straight-line running ability.

When traveling at a low speed or higher (assuming traveling within a field or traveling on a road), the braking mechanism 23 is released by slightly moving the work operation lever 19 left or right, so that turning can be started immediately when turning, and the machine's response to operation is improved.
If a difference in travel speed between the left and right sides exceeds a predetermined value when the work operation lever 19 is not being turned, the braking mechanism 23 is released, thereby preventing damage to the brake mechanism in the event of an abnormality.
The rotation sensor 27 is a pressure-sensitive type that can detect the left and right tilting operation amount (push amount) in multiple stages, and in this embodiment, it is configured to detect at least two stages: a first operation amount and a second operation amount.
Therefore, during low-speed travel (usually during mowing work), the braking mechanism 23 is not released until the work operation lever 19 is fully operated in the turning direction, thereby preventing a speed difference from occurring between the left and right traveling devices 2 at an unintended timing and maintaining straight-line travel.

When traveling at a low speed or higher (assuming traveling within a field or traveling on a road), the braking mechanism 23 is released by slightly moving the work operation lever 19 left or right, so that turning can be started immediately when turning, and the machine's response to operation is improved.
If a difference in travel speed between the left and right sides exceeds a predetermined value when the work operation lever 19 is not being turned, the braking mechanism 23 is released, thereby preventing damage to the brake mechanism in the event of an abnormality.
In this case, the auxiliary speed change lever 28 provided on the control unit 6 can also be configured to be able to switch between "work" at low speed and "travel" at normal traveling speed, and the operation of the braking mechanism 23 can be switched by operating the auxiliary speed change lever 28 to change the speed.
The braking mechanism 23 is configured to be able to vary the braking force, and when the detection value of the lever potentiometer 26 is in the low speed range, the braking force is set to "weak," and when the speed is above the low speed range, the braking force is set to "strong." The braking force is configured to change within each range depending on whether the detection value of the lever potentiometer 26 increases or decreases.

The braking mechanism 23 is configured to be able to vary the braking force using hydraulic pressure or an electric motor.
That is, as shown in FIG. 7, the braking mechanism 23 is provided with a disc holder (one-side drum) 29A and a disc caliper (other-side drum) 29B, and a multi-disc 30 provided on the disc caliper 29B is pressed against the disc by an actuator 31 such as a hydraulic cylinder or an electric motor to apply braking force.
In FIG. 7A, the multi-plate disc 30 is not pressed, the axle 24 is rotatable as output, and the braking mechanism 23 is in the braking OFF state.
In FIG. 7B, the disc caliper (other-side drum) 29B is moved by the operation of the actuator 31, and some of the multi-disc 30 comes into contact with the disc, causing frictional resistance that slows down the rotation of the axle 24.
The rotational speeds transmitted from the left and right continuously variable transmissions 20 to the axles 24 are reduced, thereby suppressing the occurrence of a difference in the rotational speeds between the left and right.

In Figure 7C, the disc caliper 29B moves due to the operation of the actuator 31, and by bringing all of the multi-disc discs 30 into contact with each other, more resistance is provided to the rotation of the axle 24, and the speed difference between the left and right traveling crawlers 10 is more effectively suppressed.
In FIG. 8A, the disc caliper 29B does not press the multi-disc disc 30, and the axle 24 can rotate as output.
In this case, the provision of the adjustment knob 71 and automatic adjustment of the braking force based on detection by the lever potentiometer 26 cannot coexist, and the braking force must be adjusted manually as needed when the aircraft is stopped.
In FIG. 8B, the disc caliper 29B moves when the knob 71 is operated, and some of the multi-disc discs 30 come into contact, causing frictional resistance to slow down the rotation of the axle 24, minimizing the speed difference between the left and right traveling crawlers 10.

In FIG. 8C, by bringing all of the multi-plate discs 30 into contact with each other, the frictional force is further increased, and the occurrence of a rotation difference between the left and right traveling crawlers 10 is suppressed.
Furthermore, the braking force applied by pressing the multi-plate disc 30 may be initially set to two levels, "weak" and "strong," and each of "weak" and "strong" may be further divided into multiple levels, for example, five levels each, such as "weak 1 to weak 5" or "strong 1 to strong 5."
The switching configuration of this braking mechanism 23 between "weak 1 to weak 5" or "strong 1 to strong 5" is arbitrary, and if "weak" is determined to be in the range of 0.1 degrees to 15 degrees and "strong" is determined to be in the range of 15.1 degrees or more to 60 degrees, the detection stages of the lever potentiometer 26 are each programmed into multiple stages (e.g., 5 stages).

For example, Weak 1...0.1 to 2.9 degrees Weak 2...3.0 to 5.9 degrees Weak 3...6.0 to 8.9 degrees Weak 4...9.0 to 11.9 degrees Weak 5...12.0 to 15.0 degrees Strong 1...15.1 to 23.9 degrees Strong 2...24.0 to 32.9 degrees Strong 3...33.0 to 41.9 degrees Strong 4...42.0 to 50.9 degrees Strong 5...51.0 to 60.0 degrees
The engagement of the multi-plate disc 30 is changed by the actuator 31 in accordance with the angle detected by the lever potentiometer 26 of the work operation lever 19 .
It is also possible to configure the engagement of the multi-plate disc 30 by the actuator 31 to be even finer than the multiple stages described above, so that the engagement of the multi-plate disc 30 can be finely adjusted according to fluctuations in the detection value of the lever potentiometer 26, i.e., a configuration that allows for stepless adjustment of the braking force.

Therefore, by setting the strength of the braking force in accordance with the operation of the travel speed of the travel operation lever 21, it is possible to prevent the course from being disturbed when traveling straight even if the travel speed is high, and the braking mechanism 23 changes quickly when a turning operation is performed, so that the load on the braking mechanism 23 can be reduced.
The braking force is changed finely due to the configuration in which the strength is changed when the running speed setting is changed, thereby improving cornering performance.
A storage device (grain tank) 5 is provided to store the collected material (grain) supplied from the ground work device 4, and a capacity sensor (weight or area sensor) 32 is provided in the storage device 5, and the braking force of the braking mechanism 23 is increased as the amount of collected material detected by the capacity sensor 32 increases.
Therefore, even if the weight balance of the aircraft changes from side to side due to the collected materials being stored, the increased braking force reduces deviation in the aircraft's direction of travel, improving operability.

The control unit 6 that controls the vehicle is provided with a heat detection sensor (thermal camera) 33 that detects (identifies) the temperature of the operator, and when the key on the control unit 6 is turned on, if the heat detection sensor 33 does not detect a temperature above a predetermined value at a position that can be considered to be the recorded operator, the drive source (engine/motor) 36 will not be started, and if the heat detection sensor 33 does not detect the operator (the operator has dismounted), the drive transmission of the drive source 36 to the traveling device 2 and working device is cut off (the clutch is disengaged or the continuously variable transmission 20 is put into neutral).
That is, a heat detection sensor 33 is provided at a predetermined position in the cabin 35 which serves as the control unit 6 so as to detect that an operator is seated in the driver's seat 34 of the control unit 6, and when the heat detection sensor 33 detects an operator, the drive source 36 can be started.
When the heat detection sensor 33 does not detect a worker, the drive power transmission from the drive source 36 to the traveling device 2 and the working device is cut off. The cutoff of the drive power transmission is performed by disconnecting a clutch (not shown) provided in the transmission path or by neutralizing the continuously variable transmission 20.

The trunnion arm (not shown), which adjusts the opening of the trunnion shaft (not shown) of the continuously variable transmission 20, is rotated by a rotary motor (not shown) for the trunnion arm to increase or decrease the forward/reverse output, but within its rotation range there is a neutral region where the output is zero, and when the control conditions are met, the rotary motor is activated to rotate the trunnion arm and move it into the neutral region, thereby setting the output of the continuously variable transmission 20 to zero and neutralizing the continuously variable transmission 20.
Therefore, the output direction is switched between forward and reverse, and the output is increased or decreased by operating the rotary motor in accordance with the angle detected by the lever potentiometer 26 .
Therefore, unless the operator is in a riding position at the control unit 6, the drive source 36 will not start even if the operator operates the keys, thereby ensuring the safety of the operator at the time of start-up.

In other words, since the control unit 6 of the agricultural work machine is basically located higher than the ground, there are cases where a worker operates it from outside the machine, or a worker inside the control unit 6 starts the driver's seat 34 before sitting in the driver's seat, and safety cannot be ensured.
In the present invention, when the heat detection sensor 33 does not detect a worker, safety is ensured by cutting off power transmission to the travel system and the working system.
Furthermore, when the operator gets off the control section 6 and is no longer detected by the heat detection sensor 33, power transmission to the running system and working system is cut off, thereby preventing the machine from suddenly moving or the operator from coming into contact with parts that are dangerous to touch while in operation.
A temperature regulator 38 is provided to adjust the temperature of the driver's seat 34 provided in the control unit 6, and the temperature of the temperature regulator 38 is adjusted according to the driver's body temperature (body surface temperature) detected by the heat detection sensor 33. When the body temperature detected by the heat detection sensor 33 is below a predetermined value (e.g., below 36 degrees), an alert is issued that the outside air temperature is low and may affect the start-up of the drive source 36, etc.

Therefore, by adjusting the temperature of the temperature regulator 38 to match the body temperature of the operator, the operator can maintain an appropriate temperature while concentrating on the work, thereby improving work efficiency.
By issuing a warning when it is determined that the environment is low temperature based on the operator's body temperature, it is possible to prompt the engine to warm up, so that the engine can be operated without putting a load on it even in a low temperature environment.
The left and right traveling crawlers 10 are configured to be driven by separate continuously variable transmissions 20, and the opening of the trunnion shafts of the left and right continuously variable transmissions 20 is controlled according to the amount of operation of the traveling control lever 21, allowing the crawler to travel straight or turn.When a difference in rotation occurs between the drive shafts 22 of the left and right continuously variable transmissions 20, braking is applied by the braking mechanism 23, and the braking force is set to be sufficiently small compared to the turning force, so that when the traveling control lever 21 is tilted left or right, the crawler will travel straight until the multi-plate disc 30 of the braking mechanism 23 slips.

In this case, "sliding" means that the left and right multi-disks 30 are in contact with each other but are still able to rotate, and the aircraft moves straight ahead.
This reduces energy loss due to braking force during cornering and simplifies the transmission configuration.
The left and right continuously variable transmissions 20 are controlled according to the direction and amount of operation of the work operation lever 19 to allow the vehicle to travel straight or turn, and the drive shafts 22 of the left and right continuously variable transmissions 20 are connected by a braking mechanism 23, and the braking force is set to a force sufficiently small compared to the turning force, and control is executed to stop operation of the braking mechanism 23 when the travel operation lever 21 is operated at low speed (operated up to the first operation amount) and when the speed is lower than low speed and the power steering is operated slightly (operated less than the first operation amount and equal to or greater than the second operation amount).

The amount of operation of the work operation lever 19 is detected by a lever potentiometer 26 and a rotation sensor 27 that can detect at least two stages.
As a result, energy loss due to unnecessary braking by the braking mechanism 23 when cornering can be suppressed, the two continuously variable transmissions 20 and the braking mechanism 23 can simplify the configuration of the transmission 70, and further, operability is improved while ensuring straight-line running ability.
Furthermore, connecting the drive shafts 22 of the left and right continuously variable transmissions 20 with the braking mechanism 23 does not strictly mean just physically connecting the drive shafts 22 of the left and right continuously variable transmissions 20, but refers to applying a braking force by the braking mechanism 23 so that when a difference in rotation occurs between the left and right drive shafts 22, the rotation speed of one drive shaft 22 becomes the same as the rotation speed of the other drive shaft 22, and this does not limit the configuration of the present invention.

The braking force of the braking mechanism 23 is set to a force sufficiently small relative to the turning force, and control is executed to stop the braking of the braking mechanism 23 when the travel control lever 21 is operated at low speed and when the travel control lever 21 is operated with more than slight operation at low speed or higher, and when the difference in left and right rotation becomes large when the travel control lever 21 is not operated and a certain time has passed, control is executed to stop the braking of the braking mechanism 23.
As a result, energy loss due to unnecessary braking by the braking mechanism 23 during cornering can be suppressed, the two continuously variable transmissions 20 and the braking mechanism 23 can be used to simplify the configuration of the transmission 70, and further, operability is improved while ensuring straight-line running, and in addition, the multi-plate disc 30 of the braking mechanism 23 can be protected, improving durability.

The braking force of the braking mechanism 23 may be adjusted by manually operating a knob 71 or the like from outside the transmission 70 to adjust the degree of pressure on the multi-plate disc 30 .
The knob 41 is operated manually and does not coexist with the configuration using the actuator 31 for automatic operation.
The degree of pressure on the multi-plate disc 30 can be adjusted by manually operating a knob 71 or the like from the outside of the transmission 70. This is not for the purpose of stopping the travel, but rather to suppress the occurrence of a speed difference between the left and right traveling crawlers 10, and its purpose is to finely adjust the frictional resistance acting on the left and right axles, so that even when tightened to the maximum, the travel speed does not decrease significantly.
As a result, energy loss due to unnecessary braking by the braking mechanism 23 when cornering can be suppressed, the two continuously variable transmissions 20 and the braking mechanism 23 can be used to simplify the configuration of the transmission 70, and further, straight-line running is ensured while operability is improved. In addition, the multi-plate disc 30 of the braking mechanism 23 can be protected, durability is improved, and the operating feel can be adjusted.

In addition, the braking force of the braking mechanism 23 is sufficiently small compared to the turning force of the aircraft, and is variable in two stages of force, so that the braking force is weak at low speeds and strong at speeds above low, and when the travel operation lever 21 is operated more than slightly, the braking of the braking mechanism 23 is stopped.
As a result, energy loss due to unnecessary braking by the braking mechanism 23 when cornering can be suppressed, the two continuously variable transmissions 20 and the braking mechanism 23 allow the transmission 70 to have a simple configuration, and further, operability can be improved while ensuring straight-line running.
The braking force of the braking mechanism 23 is configured to be changed in accordance with the vehicle speed.

This allows for stepless changes in braking force, enabling smooth cornering.
The amount of operation of the travel operation lever 21 is detected by the lever potentiometer 26 and the braking force of the braking force imparting mechanism 23 is switched in multiple stages or continuously in accordance with the detected amount. When the vehicle speed is reduced during a turn, the braking force is also reduced, and when a large speed difference occurs between the left and right travel devices during a turn, the braking force imparting mechanism 23 weakens and no extra running resistance is applied, thereby preventing running resistance from being applied during a turn and causing the running track to shake.
The braking force of the braking mechanism 23 is configured to be changed according to the amount of rice in the storage device 5.
That is, when the storage device 5 has a zero capacity, the braking force is weak, and when the storage device 5 is full, the braking force is strong.
This allows for smooth cornering as braking force changes continuously.
When the wet paddy field mode is set, the braking force of the braking mechanism 23 is made stronger.
This automatically improves straight-line stability in wet rice fields.

The operation amount of the work operation lever 19 and the opening degrees of the left and right continuously variable transmissions 20 are initially adjusted so that the left and right continuously variable transmissions 20 are output with the same rotation in response to the operation of the travel operation lever 21.
Therefore, the HST opening degree at which the left and right sides rotate in the same direction at multiple points of the main shift lever operation amount when the straight-line brake is OFF is stored. Therefore, by recording the HST opening degree at multiple points of the main shift lever operation amount, straight-line running performance is improved throughout the entire HST range.
The HST opening degree at which the brake slips at a plurality of points of the main speed change lever operation amount with the straight-ahead brake OFF is stored, and the opening degree is controlled to be larger than the opening degree at which the brake slips when the travel operation lever 21 is operated.
The braking force applying mechanism 23 applies frictional resistance to the axles of the left and right traveling devices, particularly when traveling straight, to prevent the rotational force of one side from temporarily increasing due to unevenness in the field, etc. The above-mentioned "slip" means that although a braking force is applied, the output difference between the left and right continuously variable transmissions 20 exceeds the braking force, allowing a speed difference between the left and right traveling devices to occur.

Since the travel control lever 21 and the work control lever 19 are separate, when a turning (or course adjustment) operation is performed using the work control lever 19, i.e., when a tilt operation is performed left or right, the output opening of the continuously variable transmission 20 when the braking force is exceeded and turning travel begins is lower than the output opening of the continuously variable transmission 20 when the braking force is exceeded when the travel control lever 21 is operated and a speed difference occurs between the left and right.
Therefore, the response of the travel control lever 21 during fine manipulation can be improved.
The left and right continuously variable transmissions 20 have separate HST pumps 40 and HST motors 41, and the input shafts 42 that input drive rotation to the HST pumps 40 of the left and right continuously variable transmissions 20 are configured to be coaxial with the left and right HST pumps 40 ( FIGS. 3 and 5 ).
Therefore, the input rotations of the left and right continuously variable transmissions 20 to the HST pump 40 become the same, and the difference in output rotations between the left and right continuously variable transmissions 20 can be reduced.

The HST pumps 40 and HST motors 41 of the left and right continuously variable transmissions 20 are integrated, and the input shafts 42 of the HST pumps 40 are coaxial (FIG. 4).
This simplifies the hydraulic piping. Hydraulic pressure is generated by the rotation of the drive shafts 22 of the HSTs of the left and right continuously variable transmissions 20 (using a simple hydraulic pump, etc.), and this is used as braking force for the braking mechanism 23.
Therefore, the braking force of the braking mechanism 23 can be ensured.
When the main key (not shown) of the control unit 6 is turned ON, a heat detection sensor (thermal camera) 33 that detects (identifies) the temperature of the operator detects that an operator has boarded the vehicle, and if an operator is not on board, the main key is in the ACC position and the engine will not start.
In other words, when the key on the control unit 6 is turned on, if the heat detection sensor 33 does not detect a temperature above a predetermined value at a position that can be considered to be the location of a recorded worker, the drive source (engine/motor) 36 will not be started, and if the heat detection sensor 33 does not detect the operator (the operator has dismounted), the drive transmission of the drive source 36 to the traveling device 2 and the work device will be cut off (the clutch is disengaged or the continuously variable transmission 20 is put into neutral).

In other words, the heat detection sensor 33 detects when the worker gets off the vehicle, and when the worker leaves the driver's seat 34, the drive unit (travel, reaping, threshing) stops, functioning as an interlock device.
A solar radiation sensor (sunlight sensor/light sensor) 46 is provided on the front glass 45 of the control section 6, and when sunlight is detected when an operator is on board, a sun visor 47 provided on the upper inside surface of the front glass 45 inside the cabin 35 is automatically positioned to an operating position and activated.
In addition, if the control unit 6 is configured as an open type that is not enclosed by a so-called cabin, a sun visor 47 may be provided at a predetermined position in front of the driver's seat 34 so as to be freely switchable between an operating position and a non-operating position, and when a solar radiation sensor 46 provided at a predetermined position on the control unit 6 or the like detects an amount of sunlight above a certain level, the sun visor 47 may be deployed to an operating position that covers the top of the driver's seat 34, thereby covering the top of the control unit.

In this case, if a seat air conditioner 38 is provided in the driver's seat 34, the sun visor 47 may be configured to be linked to the seat air conditioner 38 and to operate in response to the operator's body temperature and the set temperature.
It is preferable that the seat air conditioner 38 be adapted to provide both hot and cold air, as this will further improve the working environment.
In addition, when the heat detection sensor 33 determines that the conditions for cold start are met (determines that the outside air temperature is low) based on the operator's body surface temperature, etc., a monitor panel (not shown) in the control unit 6 displays warnings for cold start.
In this case, the "notes" may be, for example, a message such as "Please warm up the engine."

A straw cutter 50 is provided at the rear of the sorting device 3, which cuts the waste straw before discharging it outside the machine. Below the straw cutter 50, a width switching device 51 is provided to switch the spread width of the waste straw shredded by the straw cutter 50 between wide and narrow (see Figure 9).
The straw discharge cutter 50 is provided at a lower end position of the straw discharge conveying device 52.The configuration of the straw discharge cutter 50 is arbitrary, but one example, not shown in the figure, is a configuration in which multiple cutter blades are arranged side by side at a predetermined interval on the left and right sides of rotating shafts arranged side by side in the front and back, and the cutter blades of the front and rear rotating shafts are arranged so that they partially overlap in the front-to-back direction when viewed from the side, and the straw falling from the straw discharge conveying device 52 is cut and dropped into the field.
Below the straw discharge cutter 50, a spreading width switching device 51 is provided which switches the discharge range (spreading width) into which the cut straw shredded by the straw discharge cutter 50 is discharged between wide and narrow.

The width switching device 51 has a variable straw discharge body (diffusion guide plate or diffusion guide rod) 53 in the front-to-rear direction formed by a pair of left and right axial rod bodies, the base of the variable straw discharge body 53 is rotatably attached to a position switching unit 55 having a switching motor 54, the tip (rear end) of the variable straw discharge body 53 is formed as a free end, and the switching motor 54 rotates the tip position of the variable straw discharge body 53 to the left and right relative to the position switching unit 55, and in Figure 9, when it is positioned on the right side, the cutter diffusion width becomes ``wide'', and when it is positioned on the left side, the cutter diffusion width becomes ``narrow''.
This straw discharge cutter 50 and width switching device 51 are effective in normal harvesting work, but when manual harvesting work is performed with the machine stopped, the straw accumulates below the outlet of the straw discharge cutter 50, and if it accumulates too much, it becomes difficult to work when plowing, etc.
Therefore, in the present invention, the width switching device 51 is controlled so that the spreading state is automatically switched to the "wide" side when rowing.

Therefore, accumulation of straw below the outlet of the straw removal cutter 50 can be prevented when manually threshing.
In addition, not only when the machine is being handled by hand, but also when the machine is stopped, the spread state of the width switching device 51 is automatically switched to the "wide" side.
Therefore, it is possible to prevent straw from accumulating below the outlet of the straw disposal cutter 50 when the machine is stopped, and control to prevent straw from accumulating can be performed automatically, improving operability.
When the forward tilt angle of the aircraft is equal to or greater than a certain value, the width switching device 51 is controlled to automatically switch the diffusion to the "narrow" side.
The "forward tilt angle" of this machine means that, if the angle before entering the field is 0 degrees, the machine is in a downward tilted position with the front at a depression angle.In this driving state, the machine is in a "tail-up" position, and the straw discharge range is likely to face the road.If the straw dispersion range of the straw discharge cutter 50 is wide, the straw will easily be blown away by the wind, making cleaning difficult.
In other words, even when the front of the machine is tilted downwards when entering the field, it may still be necessary to harvest and sort the stalks in the field.In such cases, as mentioned above, the rear of the machine is often outside the field, and if the discarded straw is cut and scattered as is, it will contaminate the surrounding area and subsequent disposal will take time.

Therefore, in the present invention, when the forward tilt angle of the aircraft body is equal to or greater than a certain level, the width switching device 51 automatically switches the diffusion switch to the "narrow" side.
Therefore, by discharging the waste straw in as small an area as possible, subsequent cleaning and other work can be made easier.
When the aircraft is traveling at an extremely low speed, the width switching device 51 is automatically controlled to switch the spread to the "wide" side.
When the speed is changed from normal cutting speed to extremely slow speed, the same amount of straw is discharged as at normal cutting speed, but because the traveling speed is slower, the straw accumulates below the cutter outlet.
Therefore, when traveling at extremely low speeds, the width switching device 51 is automatically switched to the "wide" side to diffuse the straw discharge and prevent the straw from accumulating below the cutter outlet.
The position switching portion 55 of the width switching device 51 is configured to be electrically switchable.
Therefore, the frequency of spreading switching can be reduced.

The width switching device 51 of the variable straw discharge body 53 of the straw discharge cutter 50 is configured to be able to switch the spreading mode electrically, and when the feed chain is driven at an extremely low speed, and when the ground work device 4's grain stalk presence detection sensor (not shown) detects it when the speed is changed to an extremely low speed, the spreading mode is automatically switched to the ``wide'' side.
When the stalk presence/absence detection sensor detects the presence of stalks on the ground work device 4, straw is supplied from the ground work device 4 to the straw discharge cutter 50, and the width switching device 51 of the variable straw discharge body 53 of the straw discharge cutter 50 is switched to "diffusion".
When the vehicle moves backward, the width switching device 51 is automatically switched to the "narrow" side.
When reversing, the machine often approaches the side of the road, so the gear is switched to the "narrow" side to prevent discarded straw from scattering onto the road.

After the aircraft is operated from a reverse state to a forward state and travels a certain distance, the spread switching of the position switching unit 55 of the width switching device 51 is returned to the original state.
Since straw may be discharged even while moving forward, by setting the diffusion to the "narrow" side for a certain distance, the straw can be discharged in as narrow an area as possible, making cleaning easier.
A smartphone placement section 61 and an external power socket 62 are mounted on a side panel section 60 of the control section 6.
This simplifies and stabilizes the routing of smartphone charging cables, allowing cables to be connected over the shortest distance possible.
The socket 62 is located below the smartphone placement section 61, and the external socket 62 is directed toward the rear of the device.
The smartphone placement section 61 is disposed at a position lower (recessed) than the upper surface of the side panel section 60 .

This prevents the smartphone from falling, allows water and debris to be removed, and stabilizes the terminals.
The smartphone placing section 61 is surrounded by an upright wall 63, and the smartphone placing section 61 is formed in a recessed shape relative to the side panel section 60, and one or more cutout sections 64 are provided at predetermined positions on the outer periphery of this upright wall 63.
Therefore, the cutout portion 64 can be used to connect and operate the cable, improving operability.
The overall width of the smartphone placement section 61 is configured to be adjustable.
The configuration of the adjustment mechanism is arbitrary, but as an example, a side adjustment plate body 65 and a rear adjustment plate body 66 are movably provided on the side panel portion 60 on which the smartphone mounting portion 61 is provided, and the side adjustment plate body 65 and the rear adjustment plate body 66 are slid to adjust the size of the smartphone mounting portion 61 to the size of the smartphone.
This prevents the smartphone from falling off the smartphone placement section 61.
72 is an adjustment bolt.

In addition, it stabilizes the routing of smartphone charging cables, allowing you to connect the cable at the shortest distance.
The connection and terminals are stable, the smartphone can be prevented from falling, and water and dust can be easily removed from the smartphone placement section 61.
The rear adjustment plate body 66 is slidable relative to the smartphone mounting portion 61, allowing the overall length of the smartphone mounting portion 61 to be adjusted, and the position of the rear adjustment plate body 66 is fixed by inserting an adjustment bolt 67 into an insertion hole provided in the upright wall 63.
This allows for stable routing of the smartphone charging cable, allows the cable to be connected over the shortest distance, stabilizes the connection and terminals, prevents the smartphone from falling, and makes it easy to remove water and debris from the smartphone placement section 61.

1...machine frame, 2...traveling device, 3...sorting device, 4...ground work device, 5...storage device, 6...control unit, 10...traveling crawler, 12...driving rotor, 19...work operation lever, 20...stepless transmission, 21...traveling operation lever, 22...drive shaft, 23...braking mechanism, 24...axle, 25...rotation sensor, 26...lever potentiometer, 27...swing sensor, 28...auxiliary transmission lever, 29...disc holder, 30...multiple disc, 31...actuator, 32...capacitance sensor, 33...heat detection sensor, 34...driver's seat, 35...cabin, 36...drive source, 38...seat air conditioner , 40...HST pump, 41...HST motor, 42...input shaft, 45...windshield, 46...solar radiation sensor, 47...sun visor, 50...straw discharge cutter, 51...width switching device, 52...straw discharge transport device, 53...variable straw discharge body, 54...switching motor, 55...position switching unit, 60...side panel unit, 61...smartphone placement unit, 62...socket, 63...standing wall, 64...cutout unit, 65...side adjustment plate body, 66...rear adjustment plate body, 67...adjustment bolt, 70...transmission, 71...knob.

Claims (6)

A work vehicle equipped with left and right traveling devices (2) for traveling in a field, a ground work device (4) for performing ground work, a continuously variable transmission (HST) (20) for changing the traveling speed and direction of travel (forward/reverse movement, left and right turning), and a travel operation lever (21) for operating the continuously variable transmission (20), wherein a pair of continuously variable transmissions (20) for transmitting power to the traveling devices (2) are arranged on the left and right, and a braking mechanism (23) is provided for applying braking to each of the drive shafts (22) of the left and right continuously variable transmissions (20), and the braking force of the braking mechanism (23) is set to be lower than the turning force for turning the vehicle body. A work vehicle as described in claim 1, characterized in that it is provided with a rotation sensor (25) that detects the rotation speed of the axles (24) of the left and right traveling devices (2), a lever potentiometer (26) that detects the forward/backward operation amount of the traveling operation lever (21) (i.e., forward/reverse movement and gear change operation), and a swing sensor (27) that detects the left and right operation of the work operation lever (19), and the braking of the braking mechanism (23) is released when the swing sensor (27) detects a first operation amount when the detection value of the lever potentiometer (26) is in the low speed range, or when the detection value of the lever potentiometer (26) is in the low speed range or higher and the swing sensor (27) detects a value less than the first operation amount and equal to or greater than the second operation amount (micro-operation), or when the swing sensor (27) is not detecting and the rotational difference between the left and right traveling speeds is equal to or greater than a certain level. The work vehicle described in claim 2, characterized in that the braking mechanism (23) is configured to vary the braking force, setting the braking force to "weak" when the detection value of the lever potentiometer (26) is in the low speed range, and setting the braking force to "strong" when the speed is above the low speed range, and the braking force is configured to vary within the respective ranges as the detection value of the lever potentiometer (26) increases or decreases. A work vehicle as described in any one of claims 1 to 3, characterized in that it is provided with a storage device (grain tank) (5) for storing collected material (grain) supplied from the ground work device (4), a capacity sensor (weight or area sensor) (32) is provided in the storage device (5), and the braking force of the braking mechanism (23) is increased as the amount of collected material stored detected by the capacity sensor (32) increases. A work vehicle as described in any one of claims 1 to 3, characterized in that the control unit (6) that controls the vehicle is provided with a heat detection sensor (thermal camera) (33) that detects (identifies) the temperature of the operator, and the drive source (36) is not started unless the heat detection sensor (33) detects a temperature above a predetermined value at a position that can be considered to be the recorded worker when the control unit (6) is keyed on, and when the heat detection sensor (33) does not detect the operator (i.e., the operator has dismounted), the drive transmission of the drive source (36) to the traveling device (2) and work device is cut off. The work vehicle described in claim 5 is provided with a temperature-adjusting seat air conditioner (38) for adjusting the temperature of the driver's seat (34) provided in the control section (6), and is configured to adjust the temperature of the seat air conditioner (38) according to the driver's body temperature (body surface temperature) detected by a heat detection sensor (33), and is configured to issue a warning that the outside air temperature is low and may affect the start-up of the drive source (36) when the body temperature detected by the heat detection sensor (33) is below a predetermined value.