Work vehicle

Abstract

To address an ongoing problem that since one continuously variable transmission is used to transmit power to left and right travel crawlers, a braking device that provides a strong braking force which decelerates a travel crawler existing inside a turn during the turn has to be installed for each of the left and right travel crawlers, and this causes complication of a structure or an increase in the size of the structure.SOLUTION: A work vehicle includes left and right travel apparatuses 2 that travel in a field, a ground work apparatus 4 that performs ground work, continuously variable transmissions (hydrostatic transmissions (HST)) 20 that change traveling speeds and advancing directions (advancing, backing, leftward turning, and rightward turning), and a travel operation lever 21 with which the continuously variable transmissions 20 are operated. A pair of left and right continuously variable transmissions 20 are disposed in order to transmit power to the respective travel apparatuses 2. A braking appending mechanism 23 is included in order to append braking to each of drive shafts 22 of the left and right continuously variable transmissions 20. The braking force of the braking appending mechanism 23 is lower than a turning force which turns a body of the work vehicle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a work vehicle.

Background Art

[0002] Conventionally, there has been a continuously variable transmission device including a hydraulic motor that operates a variable pump by driving force from an engine and changes the traveling direction and traveling output by changing the oil feeding direction and oil feeding amount of the working oil. Thus, a configuration for increasing or decreasing the traveling speed, stopping, and switching between forward and reverse is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the known example, since it is transmitted from one continuously variable transmission device to the left and right traveling crawlers, it is necessary to provide a braking device with a strong braking force for decelerating the traveling crawler on the inner side of turning on the left and right, which causes the structure to become complicated and large-sized. In addition, since basically no braking force is applied during straight traveling, a difference occurs in the driving speeds of the left and right traveling crawlers, and if this accumulates, the traveling direction may gradually shift left and right, resulting in problems such as the working positions overlapping and the working efficiency decreasing, or positions where work is not performed occurring and extra work requiring time and labor. The present application devises the configuration of the transmission device and provides a traveling device with excellent straight traveling stability.

Means for Solving the Problems

[0005] The invention according to claim 1 is a work vehicle comprising left and right traveling devices 2 that travel in a field, a ground working device 4 that performs ground work, a continuously variable transmission (HST) 20 that changes the traveling speed and the traveling direction (forward and backward, left and right turning), and a traveling operation lever 21 that operates the continuously variable transmission 20. In this work vehicle, a pair of left and right continuously variable transmissions 20 that transmit power to the traveling devices 2 are arranged, and a braking force applying mechanism 23 that applies braking to each of the drive shafts 22 of the left and right continuously variable transmissions 20 is provided. The braking force of the braking force applying mechanism 23 is set to be lower than the turning force for turning the vehicle body. The invention according to claim 2 is provided with a rotation sensor 25 that detects the rotational speed of the axles 24 of the left and right traveling devices 2, a lever potentiometer 26 that detects the amount of operation of the traveling operation lever 21 in the front-rear direction, and a turning sensor 27 that detects the left-right operation of the work operation lever 19. When the detected value of the lever potentiometer 26 is in the low-speed range, the turning sensor 27 detects a first operation amount, or when the detected value of the lever potentiometer 26 is in a region equal to or higher than the low-speed range, the turning sensor 27 detects less than the first operation amount and equal to or more than a second operation amount, or when the turning sensor 27 is in a non-detection state and the rotational difference between the left and right traveling speeds is equal to or more than a certain value, the braking of the braking force applying mechanism 23 is released. This is the work vehicle according to claim 1. In the invention according to claim 3, the braking force applying mechanism 23 is configured to be able to vary the braking force. When the detected value of the lever potentiometer 26 is in the low-speed range, the braking force is set to be "weak", and when it is in a region equal to or higher than the low-speed range, the braking force is set to be "strong". The above braking force changes within each range according to the increase and decrease of the detected value of the lever potentiometer 26. This is the work vehicle according to claim 2. In the invention according to claim 4, a storage device (grain tank) 5 that stores the recovered material (grain) supplied from the ground working device 4 is provided, a capacity sensor (weight or area sensor) 32 is provided in the storage device 5, and the braking force of the braking force applying mechanism 23 is increased as the storage amount of the recovered material detected by the capacity sensor 32 increases. This is the work vehicle according to any one of claims 1 to 3. In the invention according to claim 5, a thermal detection sensor (thermal camera) 33 for detecting (identifying) the temperature of the operator is provided in the operation unit 6 for operating the aircraft body. When the thermal detection sensor 33 does not detect a temperature equal to or higher than a predetermined value at a position where it can be regarded as the recorded operator when the key of the operation unit 6 is turned on, the drive source (engine / motor) 36 is not started. When the thermal detection sensor 33 does not detect the operator (the operator has gotten off), the drive transmission of the drive source 36 to the traveling device 2 and the working device is cut off (the clutch is disengaged, or the continuously variable transmission 20 is neutralized). The work vehicle according to any one of claims 1 to 3, characterized in that it is configured as described above. In the invention according to claim 6, a temperature adjuster seat air conditioner 38 for adjusting the temperature of the driver's seat 34 provided in the operation unit 6 is provided, and the temperature of the seat air conditioner 38 is adjusted according to the body temperature (body surface temperature) of the operator detected by the thermal detection sensor 33. When the detected body temperature of the thermal detection sensor 33 is less than a predetermined value (for example, less than 36 degrees), a configuration is provided to notify that the outside air is at a low temperature and it affects the start of the drive source 36 and the like. The work vehicle according to claim 5, characterized in that it is configured as described above.

Advantages of the Invention

[0006] In the invention according to claim 1, a pair of left and right continuously variable transmissions 20 that transmit power to the traveling device 2 are arranged, and a braking force applying mechanism 23 for applying braking to each drive shaft (output shaft) 22 of the left and right continuously variable transmissions 20 is provided. The braking force of the braking force applying mechanism 23 is set to be lower than the turning force for turning the aircraft body. Therefore, even during straight running, if a rotational difference (speed difference) occurs in the rotation of the axles 24 between 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 force applying mechanism 23 to correct the variation in the rotational speeds of the left and right axles 24. Further, since the braking force of the braking force applying mechanism 23 is set to be weaker than the turning force for turning the aircraft body, even if a speed difference occurs between the left and right axles 24 during aircraft body turning, the braking force applying mechanism 23 is set to a non-operating state, and smooth aircraft body turning is possible without generating useless energy loss due to braking. Furthermore, a pair of left and right continuously variable transmission devices 20 are arranged. Since clutches or brakes for switching the rotation transmitted to the left and right axles are not provided as in the prior art, and shifting and turning can be performed without complicated gear switching, simplification of the running transmission system can be achieved. In the invention of claim 2, a rotation sensor 25 for detecting the rotational speed of the axles 24 of the left and right traveling devices 2 is provided, a lever potentiometer 26 for detecting the amount of operation in the front-rear direction (= forward and backward movement and shifting operation) of the traveling operation lever 21 is provided, and a turning sensor 27 for detecting the operation in the left-right direction (left and right turning operation) of the work operation lever 19 is provided. When the detected 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 detected value of the lever potentiometer 26 is in a region equal to or higher than the low-speed range, the turning sensor 27 detects less than the first operation amount and equal to or more than the second operation amount (micro-operation), or when the turning sensor 27 is in an undetected state and the rotational difference between the left and right traveling speeds is a certain value or more, the braking of the braking mechanism 23 is released. Therefore, during low-speed running (normally assuming a mowing operation), the braking of the braking mechanism 23 is not released until the work operation lever 19 is sufficiently operated in the turning direction, so that a speed difference can be prevented from occurring between the left and right traveling devices 2 at an unintended timing, and straight running performance is maintained. During running at a speed equal to or higher than low speed (assuming moving running in the field or road running), when the work operation lever 19 is slightly moved in the left-right direction, the braking mechanism 23 is released, so that turning can be started immediately when performing turning running, and the followability to the operation of the machine body is improved. When a left-right difference in the traveling speed of a predetermined value or more occurs in a situation where the work operation lever 19 is not being turned, the braking mechanism 23 is released, so that it is possible to prevent the brake mechanism from being damaged when an abnormality occurs. In the invention of claim 3, the braking force applying mechanism 23 is configured to be able to vary the braking force. When the detected value of the lever potentiometer 26 is in the low speed range, the braking force is set to "weak", and when it is above the low speed range, the braking force is set to "strong". The above-mentioned braking force changes within each range according to the increase and decrease of the detected value of the lever potentiometer 26. Therefore, by setting the strength of the braking force in accordance with the operation of the traveling speed of the traveling operation lever 21, it is possible to prevent the travel path from being disturbed during straight running even when the traveling speed is high, and since the braking force applying mechanism 23 changes promptly during turning operation, the load on the braking force applying mechanism 23 can be reduced. With a configuration in which the strength is also changed when the traveling speed setting is changed, the braking force can be finely changed, so the turning performance can be improved. In the invention of claim 4, a storage device (grain tank) 5 for storing the recovered material (grain) supplied from the ground working device 4 is provided, and a capacity sensor (weight or area sensor) 32 is provided in the storage device 5. As the storage amount of the recovered material detected by the capacity sensor 32 increases, the braking force of the braking force applying mechanism 23 is increased. Therefore, even if there is a change in the weight balance in the left-right direction of the machine body due to the stored recovered material, the deviation in the traveling direction of the machine body can be suppressed by increasing the braking force, and the operability can be improved. In the invention of claim 5, a heat detection sensor (thermal camera) 33 for detecting (identifying) the temperature of the operator is provided in the control unit 6 for operating the machine body. When the heat detection sensor 33 does not detect a temperature equal to or higher than a predetermined value at a position where it can be regarded as the recorded operator when the key of the control unit 6 is turned on, the drive source (engine / motor) 36 is not started. When the heat detection sensor 33 does not detect the operator (has gotten off the vehicle), the drive transmission of the drive source 36 to the traveling device 2 and the working device is blocked (the clutch is disengaged, or the continuously variable transmission 20 is neutralized). Therefore, if the operator is not in the boarding posture at the control unit 6, the drive source 36 will not start even if the key is operated, ensuring the safety of the operator at startup. In the invention of claim 6, a temperature regulator 38 for adjusting the temperature of the driver's seat 34 provided in the control unit 6 is provided, and the temperature of the temperature regulator 38 is adjusted according to the body temperature (skin temperature) of the operator detected by the heat detection sensor 33. When the detected body temperature of the heat detection sensor 33 is less than a predetermined value (for example, less than 36 degrees), a configuration is adopted to notify that the outside air is at a low temperature and it affects the start of the drive source 36 and the like. Therefore, since the temperature of the temperature regulator 38 is adjusted according to the body temperature of the operator, the operator can ensure an appropriate temperature while concentrating on the work, and the work efficiency is improved. In addition, by notifying when it is determined from the body temperature of the operator that the environment is a low-temperature environment, the warm-up operation can be promoted, so that the engine can be operated without applying a load even in a low-temperature environment.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Best Mode for Carrying Out the Invention

[0008] An embodiment of the present invention will be described with reference to the drawings. 1 is a body frame (vehicle body frame), 2 is a traveling device that travels on a field provided below the body frame 1, 3 is a sorting device (threshing device) provided above the body frame 1. A ground working device 4 for performing ground working to process crops is provided in front of the traveling device 2, and a storage device (storage tank, grain tank) 5 for storing the crops processed by the ground working device 4 is provided. 6 is a control unit. In describing the present invention, for ease of understanding, directions such as front and rear, left and right, and up and down are indicated with reference to the traveling direction of the work vehicle. However, the configuration of the present invention is not limited thereby. The traveling device 2 is configured to include a pair of left and right traveling crawlers 10. The traveling crawler 10 is wound around the outer periphery of a plurality of idlers 15 provided between a driving rotating body (driving wheel) 12 provided on the front side of a traveling frame (crawler frame, idler frame) 11 and a pressure regulating rotating body (idler wheel, tension roller) 13 provided on the rear side.

[0009] That is, in a work vehicle including left and right traveling devices 2 that travel on a field, a ground working device 4 that performs ground working, a continuously variable transmission (HST) 20 that changes the traveling speed and traveling direction (forward and backward, left and right turning), and a traveling operation lever 21 that operates the continuously variable transmission 20, a pair of left and right continuously variable transmissions 20 that transmit power to the traveling device 2 are arranged, and a braking force applying mechanism 23 that applies braking to each of the drive shafts (output shafts) 22 of the left and right continuously variable transmissions 20 is provided. The braking force of the braking force applying mechanism 23 is set to be lower than the turning force for turning the body. Basically, when the travel operation lever 21 is operated forward, the left and right continuously variable transmissions 20 output the same rotational speed to the left and right travel crawlers 10. When the work operation lever 19 is tilted to either the left or right, the machine body is turned. This turning configuration is optional. For example, among the left and right continuously variable transmissions 20, when one of the continuously variable transmissions 20 is increased in speed (or decreased in speed), a slow turn is performed. When one of the continuously variable transmissions 20 is increased in speed and the other continuously variable transmission 20 is decreased in speed among the left and right continuously variable transmissions 20, a sharp turn is performed. When one of the continuously variable transmissions 20 is rotated forward and the other continuously variable transmission 20 is rotated backward among the left and right continuously variable transmissions 20, a turn called a so-called spin turn, which changes direction on the spot, can be executed.

[0010] In this case, when the machine body is operated for straight travel, the left and right continuously variable transmissions 20 output the same output rotation to the axles 24 of the drive rotors 12. However, the rotational speeds of the left and right axles 24 may differ due to travel resistance or the like. As a result, the travel direction of the machine body may deviate slightly to the left or right, and the straight travel stability may be lacking. Therefore, even during straight travel, when a rotational difference (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 application mechanism 23 to correct the variation in the rotational speeds of the left and right axles 24. The braking force of the braking application mechanism 23 is set to be weaker than the turning force for turning the machine body, and is comprehensively determined based on the speed difference and the traveling direction of the left and right axles 24 so that turning is possible. That is, in the conventional travel device, a brake was applied to the rotation of one of the left and right axles 24 inside the transmission case to turn the machine body. Distinguishing from applying such a braking force, in order to correct the rotational difference between the left and right axles 24, a braking force is applied to one of the axles 24. Distinguishing from the braking force for turning, therefore, it is expressed that "the braking force of the braking application mechanism 23 is set to be lower than the turning force for turning the machine body".

[0011] Therefore, even when the braking application mechanism 23 applies a braking force to the rotating shaft 24, the machine body does not turn. Rather, the straight travel performance can be improved. In other words, when it is determined that the machine body is turning, the braking by the braking mechanism 23 is not executed. Therefore, by changing the driving speed of the left and right traveling devices 2 by the output changes of the left and right continuously variable transmissions 20, shifting and turning can be performed without complicated gear shifting as in the prior art, thus simplifying the traveling transmission system. The braking mechanism 23 is provided between the left and right of the continuously variable transmission 20. Thus, even if a difference occurs in the driving speeds of the left and right traveling crawlers 10 during straight running, the braking mechanism 23 decelerates the high-speed side, so that the traveling direction can be kept straight.

[0012] Also, since the braking force is such that it does not interfere with turning, the turning operation becomes smooth. A rotation sensor 25 for detecting the rotational speeds of the axles 24 of the left and right traveling devices 2 is provided, a lever potentiometer 26 for detecting the amount of operation in the front-rear direction (= forward and backward movement and shifting operation) of the traveling operation lever 21 is provided, and a turning sensor 27 for detecting the left-right direction operation (left and right turning operations) of the work operation lever 19 is provided. When the detection value of the lever potentiometer 26 is in the low-speed range (= small operation angle), if the turning sensor 27 detects a first operation amount, or when the detection value of the lever potentiometer 26 is in a region equal to or higher than the low-speed range, if the turning sensor 27 detects less than the first operation amount and equal to or more than a second operation amount (minute operation), or when the turning sensor 27 is in a non-detection state and the rotational difference between the left and right traveling speeds is a certain value or more, the braking of the braking mechanism 23 is released. Therefore, during low-speed running (usually assuming a mowing operation), the braking of 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 traveling devices 2 at an unintended timing and maintaining straight running performance.

[0013] During running at a speed equal to or higher than low speed (assuming movement running in the field or on the road), when the work operation lever 19 is slightly moved in the left-right direction, the braking mechanism 23 is released, so that turning can be started immediately when performing a turning operation, improving the followability of the machine body to the operation. When a left - right difference in traveling speed greater than or equal to a predetermined value occurs without the turning operation of the work operation lever 19, by releasing the braking force applying mechanism 23, it is possible to prevent the brake mechanism from being damaged when an abnormality occurs. The turning sensor 27 has a pressure - sensitive type configuration capable of detecting the left - right tilting operation amounts (pushing - in amounts) in multiple stages. In this embodiment, it is configured to detect at least two stages, namely, the first operation amount and the second operation amount. Therefore, during low - speed traveling (assuming mowing work under normal conditions), by not releasing the braking of the braking force applying mechanism 23 until the work operation lever 19 is sufficiently operated in the turning direction, it is possible to prevent a speed difference from occurring between the left - and right traveling devices 2 at an unintended timing, and straight - running performance is maintained.

[0014] During traveling at a speed equal to or higher than low speed (assuming traveling within a field or on a road), when the work operation lever 19 is slightly moved in the left - right direction, the braking force applying mechanism 23 is released. Therefore, when performing a turning operation, turning can be started immediately, and the followability to the operation of the machine body is improved. When a left - right difference in traveling speed greater than or equal to a predetermined value occurs without the turning operation of the work operation lever 19, by releasing the braking force applying mechanism 23, it is possible to prevent the brake mechanism from being damaged when an abnormality occurs. In this case, the sub - speed change lever 28 provided on the control unit 6 may 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 force applying mechanism 23 may be switched by the shift operation of the sub - speed change lever 28. The braking force applying mechanism 23 is configured to be able to vary the braking force. When the detected value of the lever potentiometer 26 is in the low - speed range, the braking force is set to "weak", and when it is in a range higher than the low - speed range, the braking force is set to "strong". The above - mentioned braking force changes within each range according to the increase and decrease of the detected value of the lever potentiometer 26.

[0015] The braking force applying mechanism 23 is configured to be able to vary the braking force by hydraulic pressure or an electric motor. That is, as shown in Fig. 7, the braking force applying mechanism 23 is provided with a disk presser body (one-side drum) 29A and a disk caliper (the other-side drum) 29B, and the multi-plate disk 30 provided on the disk caliper 29B is pressed by an actuator 31 such as a hydraulic cylinder or an electric motor to apply a braking force. In Fig. 7A, the multi-plate disk 30 is not pressed, the axle 24 can rotate as output, and it is the braking OFF state of the braking force applying mechanism 23. In Fig. 7B, due to the operation of the actuator 31, the disk caliper (the other-side drum) 29B moves, and when some of the multi-plate disks 30 come into contact, the rotation of the axle 24 becomes slower due to the frictional resistance. The rotational speed transmitted from the left and right continuously variable transmissions 20 to the axle 24 is decreased, and the generation of the difference in the rotational speeds of the left and right is suppressed.

[0016] In Fig. 7C, due to the operation of the actuator 31, the disk caliper 29B moves, and by bringing all the multi-plate disks 30 into contact with each other, more resistance is applied to the rotation of the axle 24, and the speed difference between the left and right traveling crawlers 10 can be suppressed more strongly. In Fig. 8A, the disk caliper 29B is not pressing the multi-plate disk 30, and the axle 24 can rotate as output. In this case, when the adjustment knob 71 is provided, the automatic adjustment of the braking force by the detection of the lever potentiometer 26 cannot coexist, and it will be adjusted manually as appropriate when the machine body stops. In Fig. 8B, due to the operation of the knob 71, the disk caliper 29B moves, and when some of the multi-plate disks 30 come into contact, the rotation of the axle 24 becomes slower due to the frictional resistance, and the generation of the speed difference between the left and right traveling crawlers 10 is suppressed as much as possible.

[0017] In Fig. 8C, by bringing all the multi-plate disks 30 into contact with each other, the frictional force becomes stronger, and the generation of the rotational difference between the left and right traveling crawlers 10 is suppressed. Also, first divide the braking force for pressing the multi-plate disk 30 into two levels of "weak" and "strong", and further divide each of "weak" and "strong" into multiple levels. For example, it may be divided into five levels each of "weak 1 to weak 5" and "strong 1 to strong 5". The switching configuration of "weak 1 to weak 5" and "strong 1 to strong 5" of this braking application mechanism 23 is arbitrary. If "weak" is determined in the range of 0.1 degrees to 15 degrees and "strong" is determined in the range of 15.1 degrees or more to 60 degrees, the detection stages of the lever potentiometer 26 are programmed by dividing them into multiple stages (e.g., five stages) respectively.

[0018] 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 This is the way of division, In accordance with the detected angle of the lever potentiometer 26 of the operation lever 19, the engagement of the multi-plate disk 30 is changed by the actuator 31. Note that the engagement of the multi-plate disk 30 by the actuator 31 can be made finer than the above multi-stages, and the engagement of the multi-plate disk 30 is finely adjusted by the variation of the detected value of the lever potentiometer 26, that is, it is also possible to have a configuration capable of stepless braking force adjustment.

[0019] Therefore, by setting the strength of the braking force in accordance with the operation of the traveling speed of the traveling operation lever 21, it is possible to prevent the traveling path from being disturbed during straight traveling even when the traveling speed is high, and since the braking application mechanism 23 changes promptly during turning operation, the load on the braking application mechanism 23 can be reduced. With a configuration in which the strength is also changed when the traveling speed setting is changed, the braking force is changed finely, so the turning performance is improved. A storage device (grain tank) 5 is provided to store the recovered material (grain) supplied from the ground working device 4. A capacity sensor (weight or area sensor) 32 is provided in the storage device 5. As the storage amount of the recovered material detected by the capacity sensor 32 increases, the braking force of the braking mechanism 23 is increased. Therefore, even if there are fluctuations in the weight balance in the left - right direction of the machine body due to the stored recovered material, the deviation in the traveling direction of the machine body can be suppressed by increasing the braking force, and the operability is improved.

[0020] A heat detection sensor (thermal camera) 33 for detecting (identifying) the temperature of the operator is provided in the operation unit 6 for operating the machine body. When the heat detection sensor 33 does not detect a temperature equal to or higher than a predetermined value at a position where it can be regarded as a recorded operator when the key of the operation unit 6 is turned on, the drive source (engine - motor) 36 is not started. When the heat detection sensor 33 does not detect the operator (the operator has gotten off the vehicle), the drive transmission of the drive source 36 to the traveling device 2 and the working device is cut off (the clutch is disengaged, or the continuously variable transmission 20 is neutralized). That is, the heat detection sensor 33 is provided at a predetermined position in the cabin 35 that serves as the operation unit 6 so that it can detect that an operator is seated on the operator's seat 34 of the operation unit 6. When the heat detection sensor 33 detects the operator, the drive source 36 can be started. When the heat detection sensor 33 does not detect the operator, the drive transmission of the drive source 36 to the traveling device 2 and the working device is cut off. The cut - off of the drive transmission is performed by disengaging a clutch (not shown) provided in the transmission path or by neutralizing the continuously variable transmission 20.

[0021] The trunnion arm (not shown) for adjusting the opening of the trunnion shaft (not shown) of the continuously variable transmission 20 is rotationally operated by a rotation motor (not shown) for the trunnion arm to increase or decrease the forward - backward output. There is a neutral range in which the output is in the 0 state within its rotation range. When the control conditions are met, the rotation motor operates to rotate the trunnion arm and move it to the neutral range, so that the output of the continuously variable transmission 20 becomes 0 and the neutralization of the continuously variable transmission 20 is executed. Therefore, the forward / backward output direction switching and output increase / decrease are performed by operating the rotation motor in accordance with the detected angle of the lever potentiometer 26. Therefore, when the operator is not in the riding position at the operation unit 6, the drive source 36 will not start even if a key operation is performed, ensuring the safety of the operator at startup.

[0022] That is, since the operation unit 6 of the agricultural work machine is basically at a position higher than the ground, there may be cases where an operator operating from outside the machine or an operator who has not yet seated on the driver's seat starts the operation of the driver's seat 34 while boarding the operation unit 6, and safety may not be ensured. In the present invention, when the heat detection sensor 33 does not detect the operator, safety is ensured by cutting off the transmission to the traveling system and the working system. Also, when the operator gets off the operation unit 6 and is no longer detected by the heat detection sensor 33, by cutting off the transmission to the traveling system and the working system, it is possible to prevent the machine body from suddenly starting to move and the operator from contacting dangerous parts when touching during driving. A temperature regulator 38 for adjusting the temperature of the driver's seat 34 provided in the operation unit 6 is provided, 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 detected body temperature of the heat detection sensor 33 is less than a predetermined value (e.g., less than 36 degrees), a configuration is adopted to notify that the outside air is at a low temperature and it affects the startup of the drive source 36, etc.

[0023] Therefore, since the temperature of the temperature regulator 38 is adjusted according to the body temperature of the operator, the operator can ensure an appropriate temperature while concentrating on the work, improving work efficiency. By notifying when it is determined that the environment is a low-temperature environment based on the body temperature of the operator, the warm-up operation can be promoted, so that the engine can be operated without applying a load 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 degree of the trunnion shafts of the left and right continuously variable transmissions 20 is controlled according to the operation amount of the traveling operation lever 21 to perform straight travel and turning. When a rotational difference occurs in the drive shafts 22 of the left and right continuously variable transmissions 20, braking is applied by a braking mechanism 23. The braking force is set to be sufficiently small compared to the turning force, and when the traveling operation lever 21 is tilted left or right, the machine travels straight until the multi-plate disk 30 of the braking mechanism 23 slips.

[0024] In this case, "slip" means a state in which the left and right multi-plate disks 30 are in contact but can still rotate, and the machine body travels straight. Therefore, the energy loss due to the braking force during turning is reduced, and the transmission has a simple configuration. The left and right continuously variable transmissions 20 are controlled according to the operation direction and operation amount of the work operation lever 19 to perform straight travel and turning of the machine body. The drive shafts 22 of the left and right continuously variable transmissions 20 are connected by a braking mechanism 23. The braking force is set to be sufficiently small compared to the turning force. Control is executed to stop the operation of the braking mechanism 23 during low-speed operation and when the traveling operation lever 21 is operated (up to the first operation amount), and during operation at a speed higher than low speed and during power steering fine operation (operation less than the first operation amount and greater than or equal to the second operation amount).

[0025] The operation amount of the work operation lever 19 is detected by a lever potentiometer 26 and a turning sensor 27 that can detect at least two levels. Therefore, it is possible to suppress the energy loss due to unnecessary braking of the braking mechanism 23 during turning, simplify the configuration of the transmission 70 with the two continuously variable transmissions 20 and the braking mechanism 23, and further improve the operability while ensuring straight travel performance. Also, connecting the drive shafts 22 of the left and right continuously variable transmission devices 20 with the braking force applying mechanism 23 does not strictly mean only physically connecting the drive shafts 22 of the left and right continuously variable transmission devices 20. When a rotational difference occurs between the left and right drive shafts 22, it means applying a braking force by the braking force applying mechanism 23 so that the rotational speed of the other drive shaft 22 becomes the same rotational speed in relation to the rotational speed of one drive shaft 22. Thus, the configuration of the present invention is not limited.

[0026] The braking force of the braking force applying mechanism 23 is set to be a force sufficiently small compared to the turning force. Control is executed to stop the braking of the braking force applying mechanism 23 when the traveling operation lever 21 is operated at low speed and when the operation of the traveling operation lever 21 is more than a fine operation at a speed equal to or higher than low speed. When the left and right rotational difference becomes large and a certain period of time has elapsed while the traveling operation lever 21 is not being operated, control is executed to stop the braking of the braking force applying mechanism 23. Therefore, it is possible to suppress energy loss due to unnecessary braking of the braking force applying mechanism 23 during turning, and the transmission 70 can be configured simply with the two continuously variable transmission devices 20 and the braking force applying mechanism 23. Furthermore, the straight-ahead performance is ensured while the operability is improved. In addition, the multi-plate disk 30 of the braking force applying mechanism 23 can be protected, and the durability can be improved.

[0027] Note that the braking force of the braking force applying mechanism 23 may be configured such that the degree of pressure contact of the multi-plate disk 30 can be adjusted by manual operation with a knob 71 or the like from outside the transmission 70. Note that the knob 41 is for manual operation and does not coexist with a configuration using an actuator 31 that performs automatically. The configuration in which the degree of pressure contact of the multi-plate disk 30 can be adjusted by manual operation with a knob 71 or the like from outside the transmission 70 is not for the purpose of stopping traveling, but for suppressing the generation of a speed difference between the left and right traveling crawlers 10, and the purpose is to finely adjust the frictional resistance applied to the left and right axles. Even when tightened to the maximum, the traveling speed does not decrease much. Therefore, it is possible to suppress energy loss due to braking of the unnecessary braking application mechanism 23 during turning, and the mission 70 can be configured simply with the two continuously variable transmission devices 20 and the braking application mechanism 23. Furthermore, while ensuring straight running performance, the operability can be improved. In addition, the multi-plate disk 30 of the braking application mechanism 23 can be protected, durability can be improved, and the operation feeling can be adjusted.

[0028] In addition, the braking force of the braking application mechanism 23 is set to be sufficiently smaller than the turning force of the vehicle body and is configured to be variable in two steps. Control is executed such that the braking force is weak at low speeds and strong at speeds above low speed. When the traveling operation lever 21 is operated more than a fine operation, control is executed to stop the braking of the braking application mechanism 23 of the braking application mechanism 23. Therefore, it is possible to suppress energy loss due to braking of the unnecessary braking application mechanism 23 during turning, and the mission 70 can be configured simply with the two continuously variable transmission devices 20 and the braking application mechanism 23. Furthermore, while ensuring straight running performance, the operability can be improved. The braking force of the braking application mechanism 23 is configured to change according to the vehicle speed.

[0029] Therefore, since the braking force changes continuously, smooth turning is possible. When the operation amount of the traveling operation lever 21 is detected by the lever potentiometer 26 and the braking force of the braking force application mechanism 23 is switched in multiple steps or continuously, when the vehicle speed is decreased during turning, the braking force also decreases, and during turning travel where a large speed difference occurs between the left and right traveling devices, the braking force by the braking force application mechanism 23 becomes weak, and no extra running resistance is applied. Therefore, it is possible to prevent the running resistance from being applied during turning travel and the running track from rattling. In addition, the braking force of the braking application mechanism 23 is configured to change according to the amount of paddy in the storage device 5. That is, when the yield of the storage device 5 is "zero", the braking force is weakened, and when the storage device 5 is full, the braking force is strengthened. Therefore, since the braking force changes continuously, smooth turning is possible. When the wet paddy field mode is set, the braking force of the braking application mechanism 23 is strengthened. As a result, the straight-ahead performance in paddy fields can be automatically improved.

[0030] The operation amounts 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 output the same rotation in response to the operation of the traveling operation lever 21. Therefore, the HST opening degrees at which the left and right rotate at the same speed at multiple points of the main transmission lever operation amount with the straight-ahead brake OFF are memorized. Therefore, by recording the HST opening degrees at multiple points of the main transmission lever operation amount, the straight-ahead performance across the entire HST range is improved. The HST opening degrees at which the brakes slip at multiple points of the main transmission lever operation amount with the straight-ahead brake OFF are memorized, and the control is set to an opening degree larger than the slipping opening degree when the traveling operation lever 21 is operated. The braking force applying mechanism 23 is for preventing one rotational force from temporarily increasing due to unevenness in the field or the like, by applying frictional resistance to the axles of the left and right traveling devices particularly during straight-ahead travel. The above-mentioned "slip" means that a braking force is applied, but the output difference between the left and right continuously variable transmissions 20 exceeds the braking force, and the generation of a speed difference between the left and right traveling devices is allowed.

[0031] Since the traveling operation lever 21 and the work operation lever 19 are separate components, when a turning (or course adjustment) operation is performed by the work operation lever 19, that is, when a tilting operation in the left-right direction is performed, the output opening degree of the continuously variable transmission 20 when turning travel starts beyond the braking force is set to be lower than the output opening degree of the continuously variable transmission 20 when a speed difference between the left and right occurs beyond the braking force during the operation of the traveling operation lever 21. As a result, the responsiveness during fine operation of the traveling operation lever 21 can be improved. The left and right continuously variable transmissions 20 are configured such that the HST pump 40 and the HST motor 41 are separate bodies, and the input shaft 42 for inputting driving rotation to each HST pump 40 of the left and right continuously variable transmissions 20 is the same shaft as the left and right HST pumps 40 (FIGS. 3, 5). Therefore, the input rotations to the HST pumps 40 of the left and right continuously variable transmissions 20 become the same, and the output rotation difference between the left and right continuously variable transmissions 20 can be reduced.

[0032] Integrate the HST pumps 40 and the motor HST motors 41 of the left and right continuously variable transmission devices 20, and make the input shaft 42 of the HST pump 40 the same axis on the left and right (Fig. 4). Therefore, the hydraulic piping becomes simple. Configure to generate hydraulic pressure by the rotation of the drive shafts 22 of the HSTs of the left and right continuously variable transmission devices 20 (such as a simple hydraulic pump), and use it as the braking force of 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 thermal detection sensor (thermal camera) 33 that detects (identifies) the temperature of the operator is configured to detect that the operator has boarded. If the operator has not boarded, the main key is in the ACC state and the engine cannot be started. That is, when the thermal detection sensor 33 does not detect a temperature equal to or higher than a predetermined value at a position where it can be regarded as the recorded operator when the key-on operation of the control unit 6 is performed, the drive source (engine / motor) 36 is not started. When the thermal detection sensor 33 does not detect the operator (has got off), the drive transmission of the drive source 36 to the traveling device 2 and the working device is blocked (clutch disengaged or the continuously variable transmission device 20 is neutralized).

[0033] In other words, when the thermal detection sensor 33 detects that the operator has got off the vehicle and the operator leaves the driver's seat 34, the drive unit (traveling, mowing, threshing) stops and functions as an interlock device. A solar radiation sensor (sunshine sensor / brightness sensor) 46 is provided on the front glass 45 of the control unit 6. When the solar radiation is detected when the operator boards, the sun visor 47 provided on the upper inner surface side of the front glass 45 in the cabin 35 is automatically positioned and operated at the operating position. In addition, when the control unit 6 is configured as an open type not surrounded by a so-called cabin, a sun visor 47 is provided at a predetermined position in front of the driver's seat 34 so as to be switchable between the operating position and the non-operating position. When a solar radiation sensor 46 provided at a predetermined position such as the control unit 6 detects a solar radiation amount of a certain level or more, the sun visor 47 is deployed to the operating position covering the upper part of the driver's seat 34, and it may cover the upper part of the control unit.

[0034] In this case, when the seat air conditioner 38 is provided in the driver's seat 34, the supervisor 47 may be configured to operate in conjunction with the seat air conditioner 38 and operate according to the body temperature of the operator and the set temperature. Note that if the seat air conditioner 38 can handle both heating and cooling, it is more preferable as it can further improve the working environment. Also, when the heat detection sensor 33 determines that it is a low-temperature start condition (judges that the outside air is low temperature) from the body surface temperature of the operator, etc., precautions during low-temperature start are displayed on a monitor panel (not shown) in the control unit 6. In this case, as an example, the "precautions" may include a display such as "Please perform warm-up operation".

[0035] At the rear of the sorting device 3, a straw cutter 50 is provided to discharge the straw discharged outside the machine while cutting it. Below the straw cutter 50, a width switching device 51 for switching the width of the diffusion of the straw shredded by the straw cutter 50 is provided ((Fig. 9). The straw cutter 50 is provided below the terminal of the straw conveying device 52. The configuration of the straw cutter 50 is arbitrary. As an example, although not shown in the figure, a plurality of cutter blades are arranged at a predetermined interval left and right on a rotating shaft arranged in parallel front and rear, and the cutter blades of the front and rear rotating shafts are arranged so as to partially overlap in the front-rear direction in a side view, and the straw falling from the straw conveying device 52 is cut and dropped onto the field. Below the straw cutter 50, a diffusion width switching device 51 is provided to switch the width of the discharge range (diffusion width) where the cut straw shredded by the straw cutter 50 is discharged between wide and narrow.

[0036] The width switching device 51 is provided with a variable straw body (diffusion guide plate or diffusion guide rod) 53 in the front-rear direction formed by a pair of left and right shaft rods. The base of the variable straw body 53 is rotatably attached to a position switching part 55 having a switching motor 54. The tip (rear end) of the variable straw body 53 is formed as a free end, and the tip position of the variable straw body 53 is rotated left and right with respect to the position switching part 55 by the switching motor 54. In Fig. 9, when it is located on the right side, the cutter diffusion width becomes "wide", and when it is located on the left side, the cutter diffusion width becomes "narrow". This straw cutter 50 and width switching device 51 are effective during normal mowing operations. However, during handling operations performed with the machine body stopped, straw accumulates under the outlet of the straw cutter 50. If it accumulates too much, it becomes difficult to perform operations such as the weeding operation. Therefore, in the present invention, during the pushing operation, the control is automatically switched so that the diffusion state of the width switching device 51 is switched to the "wide" side.

[0037] Therefore, it is possible to suppress the accumulation of straw under the outlet of the straw cutter 50 during handling. Also, not only during handling but also when the machine body stops, the control is automatically switched so that the diffusion state of the width switching device 51 is switched to the "wide" side. Therefore, it is possible to suppress the accumulation of straw under the outlet of the straw cutter 50 when the machine body stops, and the straw accumulation suppression control can be automatically executed, improving the operability. When the forward tilt angle of the machine body is equal to or greater than a certain value, the control is automatically switched so that the diffusion switching of the width switching device 51 is switched to the "narrow" side. This "forward tilt angle" of the machine body means that when it is 0 degrees before entering the field, it is a downward tilt posture in the depression angle. In this running state, the machine body is "rear-end up" and the discharge range of the straw is likely to face the road. The wider the straw diffusion range of the straw cutter 50, the easier it is to scatter by the wind, making cleaning difficult. That is, even when in a downward tilt state when entering the field, there may be cases where the cereal straw in the field is cut and sorted. In such cases, as described above, the rear part of the machine body is often outside the field. If the straw is cut and diffused as it is, it will contaminate the surroundings and take time for subsequent processing.

[0038] Therefore, in the present invention, when the forward tilt angle of the machine body is equal to or greater than a certain value, the diffusion switching of the width switching device 51 is automatically switched to the "narrow" side. Therefore, by discharging the straw to as narrow a location as possible, post-treatment (operations) such as cleaning can be facilitated. When the machine body is traveling at an extremely low speed, the control is executed to automatically switch the diffusion of the width switching device 51 to the "wide" side. When shifting from the normal cutting speed to an extremely low speed, the amount of discharged straw is the same as that at the normal cutting speed. Therefore, due to the slow traveling speed, the discharged straw accumulates under the cutter outlet. Therefore, when traveling at an extremely low speed, the diffusion of the width switching device 51 is automatically switched to the "wide" side to diffuse the discharged straw and suppress the accumulation of the discharged straw under the cutter outlet. The position switching part 55 of the width switching device 51 is configured to be electrically switchable. Therefore, the frequency of diffusion switching can be reduced.

[0039] The diffusion switching of the width switching device 51 of the variable straw discharging body 53 of the straw discharging cutter 50 is configured to be electrically switchable. When traveling at an extremely low speed and driven by a feed chain, and when the ground working device 4 senses the presence or absence of cereal straws (not shown) when shifting to an extremely low speed, control is executed to automatically switch the diffusion to the "wide" side. When the cereal straw presence / absence sensor senses that there is cereal straw on the ground working device 4, since the discharged straw will be supplied from the ground working device 4 to the straw discharging cutter 50, the width switching device 51 of the variable straw discharging body 53 of the straw discharging cutter 50 is switched to "diffusion". When the machine body reverses, the width switching device 51 is automatically switched to the "narrow" side. When the machine body reverses, it often approaches the roadside. To prevent the discharged straw from scattering onto the road, it is switched to the "narrow" side.

[0040] After operating the machine body from the reverse state to the forward state and advancing a certain distance, the diffusion switching of the position switching part 55 of the width switching device 51 is restored to the original state. Since the discharged straw may also be discharged during forward movement, by setting the diffusion to the "narrow" side for a certain distance, the discharged straw is discharged to as narrow a location as possible, making cleaning easier. A smartphone placement part 61 and an external power socket 62 are mounted on the side panel part 60 of the control part 6. It is possible to facilitate and stabilize the routing of the charging cable of the smartphone, and the cable can be connected at the shortest distance. The socket 62 is located below the smartphone placement part 61, and the extraction direction of the external socket 62 is towards the rear of the machine body. The smartphone placement part 61 is arranged at a position lower (recessed) than the upper surface of the side panel part 60.

[0041] Therefore, it can prevent the smartphone from falling, allow water and dust to be removed, and the terminals to be stabilized. The periphery of the smartphone placement part 61 is surrounded by a standing wall 63. The smartphone placement part 61 is formed in a concave shape with respect to the side panel part 60, and one or more notches 64 are provided at predetermined positions on the outer peripheral part of this standing wall 63. Therefore, since the connection and operation of the cable can be performed using the notch 64, the operability can be improved. The width of the entire length of the smartphone placement part 61 is configured to be adjustable. The configuration of the adjustment mechanism is arbitrary. As an example, on the side panel part 60 provided with the smartphone placement part 61, a side adjustment plate body 65 and a rear adjustment plate body 66 are movably provided. The side adjustment plate body 65 and the rear adjustment plate body 66 are slid to match the size of the smartphone placement part 61 with the size of the smartphone. Therefore, it prevents the smartphone from falling from the smartphone placement part 61. 72 is an adjustment bolt.

[0042] Also, the routing of the charging cable of the smartphone can be stabilized, the cable can be connected at the shortest distance, the connection and terminals can be stabilized, the smartphone can be prevented from falling, and water and dust can be easily removed from the smartphone placement part 61. The rear adjustment plate body 66 is slidable with respect to the smartphone placement part 61 so that the length of the entire length of the smartphone placement part 61 can be adjusted. The adjustment bolt 67 is inserted into the insertion hole provided in the standing wall 63 to fix the position of the rear adjustment plate body 66. Therefore, the routing of the charging cable of the smartphone can be stabilized, the cable can be connected at the shortest distance, the connection and terminals can be stabilized, the smartphone can be prevented from falling, and water and dust can be easily removed from the smartphone placement part 61.

Explanation of Reference Numerals

[0043] 1…Airframe frame, 2…Travel device, 3…Sorting device, 4…Ground working device, 5…Storage device, 6…Control section, 10…Travel crawler, 12…Drive rotating body, 19…Work operation lever, 20…Continuously variable transmission, 21…Travel operation lever, 22…Drive shaft, 23…Braking mechanism, 24…Axle, 25…Rotation sensor, 26…Lever potentiometer, 27…Swing sensor, 28…Sub-transmission lever, 29…Disk pressing body, 30…Multi-plate disk, 31…Actuator, 32…Capacity 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…Front glass, 46…Solar radiation sensor, 47…Sun visor, 50…Straw chopper, 51…Width switching device, 52…Straw conveying device, 53…Variable straw body, 54…Switching motor, 55…Position switching section, 60…Side panel section, 61…Smartphone placement section, 62…Socket, 63…Upright wall, 64…Notch, 65…Side adjustment plate body, 66…Rear adjustment plate body, 67…Adjustment bolt, 70…Transmission, 71…Knob.

Claims

1. A work vehicle comprising: left and right traveling devices (2) that travel in a field; a ground working device (4) that performs ground work; a continuously variable transmission (HST) continuously variable transmission (20) that changes the traveling speed and the traveling direction (forward and backward, left and right turning); and a traveling operation lever (21) that operates the continuously variable transmission (20). In the work vehicle, a pair of left and right continuously variable transmissions (20) that transmit power to the traveling devices (2) are arranged, and a braking force applying mechanism (23) that applies braking to each of the drive shafts (22) of the left and right continuously variable transmissions (20) is provided. The braking force of the braking force applying mechanism (23) is set to a force lower than the turning force for turning the vehicle body.

2. A rotation sensor (25) for detecting the rotational speed of the axles (24) of the left and right traveling devices (2) is provided, a lever potentiometer (26) for detecting the amount of operation in the front-rear direction (= forward and backward movement and speed change operation) of the traveling operation lever (21) is provided, and a turning sensor (27) for detecting the left-right operation of the work operation lever (19) is provided. When the detected value of the lever potentiometer (26) is in the low speed range, the turning sensor (27) detects a first operation amount, or when the detected value of the lever potentiometer (26) is in a region equal to or higher than the low speed range, the turning sensor (27) detects less than the first operation amount and equal to or more than a second operation amount (micro operation), or when the turning sensor (27) is in a non-detection state and the rotational difference between the left and right traveling speeds is a certain value or more, the braking of the braking force applying mechanism (23) is released. The work vehicle according to Claim 1, characterized in that.

3. The braking force applying mechanism (23) is configured to be able to vary the braking force. When the detected value of the lever potentiometer (26) is in the low speed range, the braking force is set to "weak", and when it is in a region equal to or higher than the low speed range, the braking force is set to "strong". The braking force changes within each range according to the increase and decrease of the detected value of the lever potentiometer (26). The work vehicle according to Claim 2, characterized in that.

4. A storage device (grain tank) (5) for storing the recovered material (grain) supplied from the ground working device (4) is provided, a capacity sensor (weight or area sensor) (32) is provided in the storage device (5), and the braking force of the braking force applying mechanism (23) is increased as the storage amount of the recovered material detected by the capacity sensor (32) increases. The work vehicle according to any one of Claims 1 to 3, characterized in that.

5. A thermal detection sensor (thermal camera) (33) for detecting (identifying) the temperature of the operator is provided in the control unit (6) for controlling the vehicle body. When the thermal detection sensor (33) does not detect a temperature equal to or higher than a predetermined value at a position where it can be regarded as the recorded operator when the control unit (6) is turned on, the drive source (36) is not started. When the thermal detection sensor (33) does not detect the operator (has got off the vehicle), the drive transmission of the drive source (36) to the traveling device (2) and the work device is cut off. The work vehicle according to any one of claims 1 to 3, characterized in that it is configured as such.

6. A temperature regulator seat air conditioner (38) for adjusting the temperature of the driver's seat (34) provided in the control unit (6) is provided, and the temperature of the seat air conditioner (38) is adjusted according to the body temperature (body surface temperature) of the operator detected by the thermal detection sensor (33). When the detected body temperature of the thermal detection sensor (33) is less than a predetermined value, it is configured to notify that the outside air is at a low temperature and this has an impact on starting the drive source (36) and the like. The work vehicle according to claim 5, characterized in that it is configured as such.

Images