JPH1148808A - Running control device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work vehicle wherein, when front wheels are steeringly operated, a small turn is performed by driving the front wheels at a speed higher than rear wheels and braking the rear wheel on the inner side of turning at the time of low speed running, and the small turn is restrained at the time of high speed running, by using sensors with a simple structure. SOLUTION: Based on information from a steering angle sensor 34 of front wheels 1, from a speed detection means 47 for detecting an actual running speed from the number of revolutions detected by a revolution sensor 35 of a transmission shaft 10 for use with front and rear wheels, and from a restraining means 45 for restrainingly acting on a turn control means 44 based on the speed detected by the speed detection means 47, the turn control means 44 operates energizingly/deenergizingly a front-wheel accelerating device 20 and vehicle-body steering brakes 32a, 32b. When the speed detected by the speed detection means 47 is equal to or more than a set speed, the restraint means 45 disables the front-wheel accelerating device 20 and the vehicle-body steering brakes 32a, 32b from being operated energizingly by the turn control means 44 thereby restraining a small turn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a traveling steerable wheel located at one of the front and rear ends of an airframe and a non-steerable traveling wheel located at the other end. When the steering operation is performed beyond the set turning angle, the driving state of the steered wheels becomes the same or almost the same as that of the non-steered wheels, and the driving speed of the steered wheels becomes greater than that of the non-steered wheels. A turning control means for automatically switching the front wheel speed increasing device, which can be switched to an entering state at high speed, to the entering side to turn the aircraft in a small turn, or a steerable wheel is steered beyond a set turning angle. Then, the front wheel speed increasing device and the fuselage steering brake acting on the non-steering wheel inside the turning of the pair of left and right non-steering wheels are automatically switched to the entrance side to operate the aircraft. Turn control means to make a small turn, or steer the steerable wheels beyond the set turning angle The first turning control mode in which the front wheel speed-increasing device and the body steering brake inside the turning are automatically switched to the entrance side to turn the aircraft in a small turn, and the steered wheels are out of setting. When the steering operation is performed at an angle or more, only the front wheel speed increasing device and the front wheel speed increasing device of the body steering brake are automatically switched to the entry side to perform a second turning control mode in which the aircraft is turned slightly. The present invention relates to a traveling control device for a working vehicle, which is provided with turning control means that can be switched between the two.

[0002]

2. Description of the Related Art The above-mentioned work vehicle can be easily operated simply by steering a steerable wheel by the operation of a turning control means when turning the body such as making a U-turn turn at an end of a field. The turning wheel can be turned with a smaller turning radius than turning while driving the die wheel and the non-steering wheel at the same or almost the same driving speed as in the case of going straight. Conventionally, in this type of working vehicle, for example, Japanese Unexamined Patent Publication No.
No. 62332 was disclosed. That is,
A standard drive state in which the drive speeds of the front and rear wheels are substantially equal,
The front cylinder is equipped with a front wheel transmission that can be switched by a hydraulic cylinder to a speed-up drive state in which the front wheel drive speed is higher than that of the rear wheel. The front wheel is steered to a set angle or more to control the signal from the limit switch. When input to the device, an operation signal is transmitted from the control device to a control valve for the hydraulic cylinder, so that the hydraulic cylinder switches the front wheel transmission to the front wheel speed increasing state. A limit switch is provided at the high-speed position and at the high-speed position of the sub-transmission lever. Regardless, there was a control valve that did not issue an operation signal. That is, when the traveling transmission is switched to the low-speed side, when the front wheel as the steerable wheel is steered to a predetermined turning angle or more, the front wheel as the front wheel speed increasing device is controlled by the control device as the turning control means. When the transmission is automatically switched to the entry side and the traveling transmission is switched to the high-speed side, the front wheel speed increasing device is engaged even if the steering wheel is steered beyond the set turning angle. Was not switched to the side. That is, the small-turn turning control is executed when the vehicle runs at a low speed, and the small-turn turning control is suppressed when the vehicle runs at a high speed.

[0003]

Conventionally, depending on whether a detection switch is provided at each of a plurality of operating positions of the shift lever or a detection switch is provided at each of the main shift lever and the auxiliary shift lever, either low-speed or high-speed running is performed. However, there is a problem that the structure becomes complicated from the viewpoint of the sensor mechanism, because it is possible to detect whether the vehicle is in the vehicle or not, and to make a small turn, or to check. SUMMARY OF THE INVENTION An object of the present invention is to provide a traveling control device for a work vehicle that can easily make a small turn at a low speed and perform a small turn check at a high speed with a relatively simple structure.

[0004]

The constitution, operation and effect of the invention according to claim 1 are as follows.

[Structure] A cutting state in which the driving speed of a traveling steerable wheel located at one of the front and rear ends of the body is the same as or substantially the same as that of a non-steerable traveling wheel located at the other end. With a front wheel speed-up device that can be switched to an on state where the drive speed of the steered wheels is higher than that of the non-steered wheels, and when the steered wheels are steered beyond the set turning angle,
In a traveling control device for a work vehicle having a turning control device for automatically switching a front wheel speed increasing device to an entrance side to make a small turn of the aircraft, a speed detecting device for detecting an actual aircraft traveling speed is provided, If the speed detected by the speed detecting means is lower than the set speed, the turning control means enables the switching operation to the entrance side of the front wheel speed increasing device, and if the speed detected by the speed detecting means is equal to or higher than the set speed, Checking means is provided for disabling switching operation of the front wheel speed increasing device to the entrance side by the turning control means.

[Operation] When the steered wheels are driven at a higher speed than the non-steered wheels to make a small turn, the minimum speed among the running speeds in which a trouble such as the body swaying is likely to occur is set as the set speed. Set. Since the rotation speed of the output shaft of the traveling transmission is detected by the rotation sensor and the actual vehicle traveling speed is detected based on the detected rotation speed, the actual vehicle traveling speed is detected based on the speed state of the traveling transmission. The required number of sensors is smaller than in the past,
It detects whether the vehicle is traveling at a speed lower than the set speed or at a speed higher than the above speed, and when the steering wheel is steered at a set angle or more while traveling at a speed lower than the set speed, the traction control means turns the turning control means. The front wheel speed-up device is switched to the inbound side to enable the front wheel speed-up device to be switched to the entry side, and the steerable wheels are driven at a higher speed than the non-steerable wheels and the aircraft turns slightly. Turning around the radius. Even if the steerable wheel is steered at a set turning angle or more, if the vehicle is running at the set speed or more, the restraint means disables the turning control means from switching the front wheel speed increasing device to the entrance side. Therefore, the front wheel speed increasing device is operated with the steering wheel turned off, the steered wheels and the non-steered wheels are driven at the same or almost the same speed, and the aircraft turns with the standard turning radius.

[Effect] When the vehicle is traveling at a low speed less than the set speed, the steering wheel can be easily turned only by performing the steering operation of the steering wheel, and the working device can be quickly positioned in the next work line. Therefore, when the vehicle is traveling at a speed higher than the set speed, even if the steerable wheel is steered to a set angle or more, the small turning is restrained by the restraint means and the wheel is stably operated. You can run. In addition, the structure can be simplified so that it is possible to detect whether the vehicle is traveling at a low speed or a high speed with a smaller number of sensors than in the past, which is advantageous in terms of economy and the like.

The structure, operation and effect of the invention according to claim 2 are as follows.

[Structure] A cutting state in which the driving speed of a traveling steerable wheel located at one of the front and rear ends of the body is the same as or substantially the same as that of a non-steerable traveling wheel located at the other end. A front wheel speed-up device that can be switched to an on state in which the driving speed of the steered wheels is higher than that of the non-steered wheels, and a pair of body steerings that respectively act on the pair of left and right non-steered wheels When the steered wheels are steered beyond the set turning angle, the front wheel speed increasing device and the airframe steering brake acting on the non-steered wheels inside the turn are automatically set on the entry side. In a traveling control device for a work vehicle provided with turning control means for turning the aircraft in a small turn by switching operation, speed detection means for detecting an actual aircraft traveling speed is provided, and the speed detected by the speed detecting means is set to a set speed. If it is less than If permit switching operation of the front wheel acceleration device and machine gymnastics countercurrent brake inlet side by means, detection speed by the speed detecting means is set speed or more,
Checking means for disabling switching operation of the front wheel speed increasing device and the fuselage steering brake to the entrance side by the turning control means is provided.

[Operation] When the steered wheels are driven at a higher speed than the non-steered wheels to make a small turn, the minimum speed among the running speeds in which a trouble such as the body swaying is likely to occur is set as the set speed. Set. Then, since the rotation speed of the output shaft of the traveling transmission is detected by the rotation sensor and the body traveling speed is detected based on the detected rotation speed, the detection is performed based on the speed state of the traveling transmission. The required number of sensors is smaller than the conventional sensor, which detects whether the vehicle is running at a speed lower than the set speed or at a speed higher than the set speed. When the steering operation is performed, the front wheel speed increasing device and the aircraft steering brake are moved to the entry side so that the restraint means can switch the front wheel speed increasing device and the aircraft steering brake to the entry side by the turning control means. The switching operation is performed, the steered wheels are driven at a higher speed than the non-steered wheels, and the brake is applied to the non-steered wheels inside the turning, so that the aircraft turns with a small turning radius. Then, even if the steering wheel is steered at a set turning angle or more, if the vehicle is running at the set speed or more, the check means is turned to the front wheel speed increasing device by the turning control means and the entrance side of the body steering brake. In order to disable switching, the front wheel speed-increasing device and the aircraft steering brake are operated in the off state, the steered wheels and the non-steered wheels are driven at the same or almost the same speed, and the aircraft is standard. Turn with a turning radius of.

[Effect] When the vehicle is traveling at a low speed less than the set speed, the steering wheel can be easily turned only by performing the steering operation of the steering wheel, and the working device can be quickly moved to the next work line. Therefore, when the vehicle is traveling at a speed higher than the set speed, even if the steerable wheel is steered to a set angle or more, the small turning is restrained by the restraint means and the wheel is stably operated. You can run. In addition, the structure can be simplified so that it is possible to detect whether the vehicle is traveling at a low speed or a high speed with a smaller number of sensors than in the past, which is advantageous in terms of economy and the like.

The structure, operation and effect of the invention according to claim 3 are as follows.

[Structure] A cutting state in which the driving speed of a traveling steerable wheel located at one of the front and rear ends of the body is the same as or substantially the same as that of a non-steerable traveling wheel located at the other end. A front wheel speed-up device that can be switched to an on state in which the driving speed of the steered wheels is higher than that of the non-steered wheels, and a pair of body steerings that respectively act on the pair of left and right non-steered wheels When the steered wheels are steered beyond the set turning angle, the front wheel speed increasing device and the airframe steering brake acting on the non-steered wheels inside the turn are automatically set on the entry side. A first turning control mode in which the body is turned in a small turn by switching operation to the first wheel, and when the steerable wheels are steered beyond a set turning angle, the front wheel speed increasing device and the front wheel speed increasing brake of the body steering brake are operated. Automatically switch only the device to the entry side and turn the aircraft In a traveling control device for a work vehicle having a turning control means operable to switch between a second turning control mode and a second turning control mode, a speed detecting means for detecting an actual body running speed is provided, and the turning control means comprises a first turning control means. In any of the turning control modes of the control mode and the second turning control mode, if the speed detected by the speed detecting means is lower than a set speed, the turning control means turns on the front wheel speed increasing device and the body steering brake. Side switching operation, and if the speed detected by the speed detecting means is equal to or higher than a set speed, the turning control means disables the switching operation of the front wheel speed increasing device and the body steering brake to the entrance side. Means are provided.

[Operation] When the steered wheels are driven at a higher speed than the non-steered wheels to make a small turn, the minimum speed among the running speeds in which a trouble such as the body shaking is likely to occur is set as the set speed. Set. Then, since the rotation speed of the output shaft of the traveling transmission is detected by the rotation sensor and the body traveling speed is detected based on the detected rotation speed, the detection is performed based on the speed state of the traveling transmission. With a smaller number of sensors than before, it detects whether the vehicle is traveling at a speed lower than the set speed or at a speed higher than the above. In the case of the first turning control mode, the vehicle travels at a speed lower than the set speed. When the steering wheel is steered beyond the set turning angle, the front wheel speed increase is performed so that the braking control means can switch the front wheel speed increasing device and the aircraft steering brake to the entrance side by turning control means. The device and fuselage steering brake are switched to the entry side, the steered wheels are driven at a higher speed than the non-steered wheels, and the brakes are applied to the non-steered wheels inside the turn, causing the aircraft to turn a small turning radius. Turn with Ku. Second
In the case of the turning control mode, when the steering wheel is steered at a set angle or more while traveling at a speed less than the set speed,
In order for the restraint means to be able to switch the front wheel speed increasing device by the turning control means, the front wheel speed increasing device is switched to the entrance side, and the steered wheels are driven at a higher speed than the non-steered wheels, and Turn with a small turning radius. In both the first turning control mode and the second turning control mode, even if the steerable wheels are steered at a set turning angle or more, if the vehicle is running at a set speed or more, the braking means turns. In order to make it impossible for the control means to switch the front wheel speed increasing device and the aircraft steering brake to the entry side, the front wheel speed increasing device and the aircraft steering brake are operated with the off state, and the steerable wheels and the non-steer The model wheels are driven at the same or almost the same speed, and the body turns with a standard turning radius.

[Effect] When the vehicle is traveling at a low speed less than the set speed, the steering wheel can be easily turned only by performing the steering operation of the steering wheel, so that the work device can be quickly positioned in the next work line. Therefore, when the vehicle is traveling at a speed higher than the set speed, even if the steerable wheel is steered to a set angle or more, the small turning is restrained by the restraint means and the wheel is stably operated. You can run. In addition, the structure can be simplified so that it is possible to detect whether the vehicle is traveling at a low speed or a high speed with a smaller number of sensors than in the past, which is advantageous in terms of economy and the like.

The structure, operation and effect of the invention according to claim 4 are as follows.

[Structure] In the structure according to the third aspect of the present invention, the turning control means is controlled by one push-button type changeover switch into three types, namely, control off, the first turning control mode and the second turning control mode. Each time the mode is switched and the switch is pressed,
It is configured to switch sequentially between the three modes.

[Operation] The turning control means is switched between ON and OFF by a switch dedicated to ON / OFF, and is switched between the first turning control mode and the second turning control mode by a switch dedicated to mode change. In contrast, the number of switches that need to be equipped and the number of switches that need to be operated can be reduced, and control can be turned on and off and the mode can be changed.

[Effect] By reducing the number of switches, it is possible to simplify not only the structure of the operation unit but also the operation time, and it is also possible to prevent erroneous operation.

The structure, operation and effect of the invention according to claim 5 are as follows.

[Structure] In the structure according to the third or fourth aspect of the present invention, when the power is turned on, the turning control means turns off the control and selects one of the first turning control mode and the second turning control mode. The configuration is such that the mode selected when the power-off operation is performed is set.

[Operation] Even if the work is interrupted by turning off the power such as parking and resting, when the power is turned on next time, the turning control means turns off the control, the first turning control mode, and the second turning control mode. The mode that was set when the power was turned off earlier was restored, and work can be resumed in the same mode as before the interruption without the need to set the mode again.

[Effect] Even after the power is turned off, the operation can be made excellent so that the work can be resumed in the same mode as before the power was turned off without the trouble of resetting the mode.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a pair of left and right front wheels 1, 1 which are steerable and drivable and a pair of left and right rear wheels 2, 2 which are not steerable and drivable. A steering wheel 3 for steering the front wheel 1;
An agricultural tractor having a lift arm 5 for connecting various working devices such as a rotary tilling device so as to be able to move up and down freely and a power take-off shaft 6 for transmitting power to the connected working devices, at the rear of a traveling body having a driver's seat 4 and the like. Is configured.

An engine E is provided at a driving portion located at a front portion of the traveling body, and a rear wheel differential mechanism 11 is provided at a rear portion inside a case of a transmission case 8 forming a rear portion of the traveling body.
A front wheel differential mechanism 13 is provided in a left and right intermediate portion of a front wheel transmission case 38 that supports the front wheel 1 at both ends so as to be swingably steerable. The transmission mechanism shown in FIG. Power is transmitted to the front wheel differential mechanism 13. That is, the rotational power taken out of the engine E via the main clutch 7 is input to the transmission case 8 and transmitted to the traveling transmission 9, and the rotational power of the output shaft 10 of the traveling transmission 9 is used for the rear wheels. The transmission is branched and transmitted to the differential mechanism 11 and the front wheel speed increasing device 20.
The rotation power of the output shaft 21 of zero is transmitted to the front wheel differential mechanism 13 via the rotation shaft 12. The traveling transmission 9 includes a main transmission (not shown) that shifts the rotational power from the engine E to a plurality of stages by changing the shift gear, and forwards the rotational power from the main transmission by changing the shift gear. A forward / reverse switching device (not shown) for switching between a driving force and a reverse driving force, switching the forward driving force or the reverse driving force from the forward / reverse switching device between a high speed side and a low speed side by changing a shift gear and outputting the output. Axis 10
A sub-transmission (not shown) for transmitting the power to the vehicle is provided.

As shown in FIG. 3, an input gear 22 of the front wheel speed increasing device 20 and an output gear of which the output shaft 10 of the traveling transmission 9 is integrally rotatable are provided at the inner bottom of the transmission case 8. 14, the input gear 22 is integrally rotatably provided at the other end of an input shaft 23 to which the input gear 22 is rotatably connected at one end. The speed-up transmission gear 25 meshes with one end of the output shaft 21 and the standard transmission gear 26 that meshes with the input gear 22 is supported at the other end of the output shaft 21 so as to be rotatable relative to each other. A friction clutch mechanism 27 is provided between the output shaft 21 and the standard transmission gear 26 and the output shaft 21.
Is provided with a meshing clutch mechanism 29 between a switching body 28 which is integrally rotatable and slidably provided by spline engagement to constitute the front wheel speed increasing device 20. The friction clutch mechanism 27 includes a clutch body 27a provided with the speed increasing transmission gear 25 so as to be rotatable integrally, a passive body 27b provided with the output shaft 21 so as to be able to rotate integrally by spline engagement,
A piston 31a is provided at the other end of the shifter 30 having one end engaged with the switching body 28 for relative rotation only, the multi-plate friction clutch mechanism body 27c being located between the passive body 27b and the clutch body 27a. With the hydraulic cylinder 31 connected, it can be turned on and off,
By this on / off operation, the speed increasing transmission gear 25 is connected to the output shaft 2.
1 is connected so as to rotate integrally, and this connection is released. The meshing clutch mechanism 29 is composed of an internal gear provided with a standard transmission gear 26 rotatably integrally on one side and a gear provided with a switching body 28 rotatable integrally on one side. An on / off operation can be performed by the on / off operation 31, and the standard transmission gear 26 is connected to the output shaft 21 so as to rotate integrally with the output shaft 21 by this on / off operation, and this connection is released. That is, when the hydraulic cylinder 31 is operated to the extension side, and the hydraulic cylinder 31 slides the switching body 28 through the shifter 30 toward the clutch body 27a and presses against the multi-plate friction clutch mechanism main body 27b, the multi-plate type Since the friction plates of the friction clutch mechanism main body 27b are in pressure contact with each other, the friction clutch mechanism 27 is in the engaged state, and the speed-up transmission gear 25 and the output shaft 21 are connected by friction so that the output shaft 21 and the output shaft 21 rotate integrally. I do. At this time, since the gear of the switching body 28 is disengaged from the internal gear of the standard transmission gear 26, the meshing clutch mechanism 29 is disengaged, so that the standard transmission gear 26 and the output shaft 21 rotate relative to each other. The connection between 26 and 21 is released. On the other hand, the hydraulic cylinder 31 is operated to the shortening side, and the hydraulic cylinder 31 slides the switching body 28 toward the standard transmission gear 26 via the shifter 30 to change the gear of the switching body 28 to the standard transmission gear 26. When the internal gear is meshed with the internal gear, the meshing clutch mechanism 29 is engaged due to the gear meshing, and the switching mechanism 28 is switched between the standard transmission gear 26 and the output shaft 21 so that the output shaft 21 rotates integrally. Connect through. At this time, the multi-plate friction clutch mechanism body 27c
Is released, the friction clutch mechanism 27 is disengaged, and the speed increasing transmission gear 25 and the output shaft 21 are disengaged.
The connection between the two 25 and 21 is released so that the two rotate relatively.

Thus, when the hydraulic cylinder 31 is expanded and contracted to operate the friction clutch mechanism 27 and the meshing clutch mechanism 29 of the meshing clutch mechanism 29 in the ON state, the front wheel speed increasing device 20 is switched to the OFF state. Then, the rotational power input from the output shaft 10 of the traveling transmission 9 to the input gear 22 is transmitted to the output shaft 21 via the standard transmission gear 26, the meshing clutch mechanism 29, and the switching body 28, and the rotation of the output shaft 21 is performed. Power is output to the rotating shaft 12 as front wheel driving force,
Due to the transmission ratio between the input gear 22 and the standard transmission gear 26, the drive speed of the front wheels 1 is made equal to or almost equal to the drive speed of the rear wheels 2. That is, the forward drive force or the reverse drive force is transmitted to the left and right front wheels 1 and 1 such that the average peripheral speed of the left and right front wheels 1 and 1 is equal to or approximately equal to the average peripheral speed of the left and right rear wheels 2 and 2. On the other hand, when the friction clutch mechanism 27 of the friction clutch mechanism 27 and the meshing clutch mechanism 29 is operated to the engaged state, the front wheel speed increasing device 20 is engaged, and the output shaft 10 of the traveling transmission 9 is operated. To input gear 2
2 is input to the output shaft 2 via the input shaft 23, the transmission gear 24, the speed increasing transmission gear 25, and the friction clutch mechanism 27.
1 and outputs the rotational power of the output shaft 21 to the rotating shaft 12 as front wheel driving force. In addition, because of the transmission ratio between the transmission gear 22 and the speed increasing transmission gear 25, the driving speed of the front wheel 1 Make it faster than the driving speed. That is, forward driving force or reverse driving force is transmitted to the left and right front wheels 1 and 1 such that the average peripheral speed of the left and right front wheels 1 and 1 is about 1.9 times the average peripheral speed of the left and right rear wheels 2 and 2.

As shown in FIG. 2, the rear wheel differential mechanism 1
A body steering brake 32 is provided on each of a pair of left and right output shafts.
a, 32b, and each of the body steering brakes 32a, 32b is provided with a hydraulic brake cylinder 33a,
33b, the on / off operation is performed, and when the on / off operation is performed, a friction braking force is applied to the output shaft of the rear wheel differential mechanism 11, whereby the output shaft is transmitted to the left or right rear. To apply a friction braking force to the wheel 2,
Thereafter, the steering operation is performed so that the wheels 2 are turned inside and the aircraft is turned.

As shown in FIG. 4, a turning angle sensor 34 for detecting the steering direction and the turning angle of the left and right front wheels 1, 1 and a rotation sensor 35 for detecting the number of revolutions of the output shaft 10 of the traveling transmission 9. And changeover switch 3
6 is provided to the front wheel speed increasing device 20 by configuring the turning control mechanism 37 provided with the hydraulic cylinder 31 to output an operation signal to an electromagnetic valve mechanism (not shown) of the hydraulic cylinder 31 to operate the hydraulic cylinder 31. In addition to linking the switching operations, the brake cylinders 33a and 33b output operation signals to electromagnetic valves (not shown) of the pair of brake cylinders 33a and 33b, respectively.
Is operated so that the pair of body steering brakes 32a and 32b are linked to perform these switching operations.

The turning angle sensor 34 supports the front wheel 1 at both ends so as to rotate and steer freely, and is supported at an intermediate portion of a front wheel transmission case 38 which houses the front wheel differential mechanism 13 at an intermediate portion. It consists of a detection switch.
(1) A set turning angle set as a target for detection of a switch operation member 42 provided in a pitman arm 41 that swings each knuckle arm 39 via a rod 40, and for causing the front wheel 1 to execute small turning control. A
In addition to detecting whether or not the steering has been performed, it detects whether the steering direction when the steering operation is performed beyond the set turning angle A is rightward or leftward, and turns each detection result as an electric signal. Output to the control mechanism 37. That is, when the steering handle 3 is rotated to operate the pitman arm 41 to steer the left and right front wheels 1, 1,
In both the case where the steering wheel 1 is steered from the straight running direction to the left and the case where the steering wheel is steered rightward, if the steering angle of the front wheel 1 located inside the turning from the straight running direction is less than 35 degrees, the switch operation is performed. The member 42 does not come into contact with the operation arm 34a of the detection switch, and the operation arm 34a is not pressed to the left or right. Then, the cutting angle sensor 34
Detects that the turning angle of the front wheel 1 has not reached the set turning angle A. When the left and right front wheels 1 and 1 are steered to the left, the switch operation member 42 comes into contact with the operation arm 34a as the steering angle of the left front wheel 1 positioned inside the turning from the straight traveling direction becomes 35 degrees. The switch arm 42a continues to press the operation arm 34a to the left while the operation arm 34a starts to be pressed to the left and the steering angle of the left front wheel 1 is between 35 degrees and the steering limit. Then, the turning angle sensor 34 detects that the front wheel 1 is being steered to the left by more than the set turning angle A. When the right and left front wheels 1 and 1 are steered rightward, the switch operation member 42 comes into contact with the operation arm 34a as the steering angle of the right front wheel 1 located inside the turning from the straight traveling direction becomes 35 degrees. The switch arm 42a continues to press the operation arm 34a rightward while the operation arm 34a starts to be pressed rightward and the steering angle of the right front wheel 1 is between 35 degrees and the steering limit. Then, the turning angle sensor 34 detects that the front wheel 1 is steered rightward beyond the set turning angle A or more.

As shown in FIG.
Is constituted by a gear pulse sensor, detects the number of rotations of the output shaft using the output gear 14 provided integrally with the output shaft 10 as a detection target, and uses the detection result as a speed detecting means 47 provided in the turning control mechanism 37. Output to That is, each time the tooth portion of the output gear 14 passes through the detection range of the rotation sensor 35, the rotation sensor 35 transmits a pulse to the speed detection means 47. Speed detecting means 47
Detects the number of revolutions detected by the rotation sensor 35 by measuring the number of times a pulse is transmitted from the rotation sensor 35 within a set time, and detects the actual traveling speed of the aircraft based on the detected revolution number.

As shown in FIG. 4, the changeover switch 3
Reference numeral 6 denotes a single push-button switch provided on an operation panel 43 located in a driving unit of the traveling body, and when pressed, three types of a cut mode, a first turning control mode, and a second turning control mode. One of the commands is turned control mechanism 3
7 and each time the push operation is performed, a command to be output is sequentially performed among the above three kinds of commands, and the order of the cut mode, the second swing control mode, and the first swing control mode. It is configured to switch by repeating the above. As shown in FIG. 4, the operation panel 43 has a display lamp 36a close to the changeover switch 36. The display lamp 36a is turned on and displayed when the changeover switch 36 outputs a command for the first turning control mode.

The turning control mechanism 37 is constituted by a microcomputer, and when the changeover switch 36 outputs a command for a cut-off mode, the control operation is not performed and the front wheel speed increasing device 20 and the body steering brake 32a are turned off. , 32a
When the changeover switch 36 outputs the command of the first turning control mode or the second turning control mode without performing the operation of the turning angle sensor 3 and the turning angle sensor 3
The front wheel speed increasing device 20 and the pair of body steering brakes 32a, 32a are controlled based on information from the speed control unit 4, the speed detecting means 47, the rotation sensor 35, and the changeover switch 36, and the control flow shown in FIGS. It is configured to operate automatically.

That is, when the changeover switch 36 outputs a command for the first turning control mode or the second turning control mode, the front wheel speed increasing device 20 is turned off (step # 1), and at the same time, the body operation of the left rear wheel 1 is performed. The directional brake 32a and the fuselage steering brake 32b of the right rear wheel 1 are operated to be turned off (Step # 2, Step # 3), and thereafter Step # 4 is performed.
Then, it is determined whether or not the turning angle S detected by the turning angle sensor 34 is equal to or larger than the set turning angle A. If it is determined that the detected turning angle S is not equal to or greater than the set turning angle A, the process returns to step # 1. If it is determined that the detected turning angle S is equal to or larger than the set turning angle A, the process proceeds to step # 5, and it is determined whether or not the command from the changeover switch 36 is the first turning control mode. The command from the changeover switch 36 is the first
If it is determined that the mode is the turning control mode, step #
Then, it is determined whether or not the speed V detected by the speed detecting means 47 is lower than the first set speed N1. If it is determined that the detected speed V is not lower than the first set speed N1, the process returns to step # 1. When the detected speed V is equal to the first set speed N
If it is determined that the speed is lower than 1, the process proceeds to step # 7 to operate the front wheel speed increasing device 20 in the on state, and then proceeds to step # 8 where the steering direction detected by the turning angle sensor 34 is leftward. It is determined whether or not there is. If it is determined that the vehicle is facing left, the process proceeds to step # 9, where the fuselage steering brake 32a of the left rear wheel 1 is operated, and if it is determined that the vehicle is not facing left (the detected steering direction is equivalent to right).
In step # 10, the operation proceeds to step # 10 to operate the body steering brake 32b of the right rear wheel 1 in the engaged state. After step # 9 and step # 10, the process proceeds to step # 11, where it is determined whether or not the detected turning angle S detected by the turning angle sensor 34 is smaller than the set turning angle A. If it is determined, the process returns to step # 7, and if it is determined that it is smaller than the set turning angle A, the process returns to step # 1. If it is determined in step # 5 that the command from the changeover switch 36 is not in the first turning control mode (corresponding to the case where the command from the changeover switch 36 is in the second turning control mode), the process proceeds to step # 12, and the speed is changed. Detecting means 4
It is determined whether or not the detected speed V according to 7 is lower than a second set speed N2 which is higher than the first set speed N1.
If it is determined that the speed is not lower than the second set speed N2, the process returns to step # 1. If it is determined that the speed is lower than the second set speed N2, the process proceeds to step # 13, where the front wheel speed increasing device 20 is operated to the on state, and thereafter, step # 1 is performed.
Then, it is determined whether or not the detected turning angle S detected by the turning angle sensor 34 is smaller than the set turning angle A. If it is determined that it is not smaller than the set turning angle A, step # 13
When it is determined that the angle is smaller than the set turning angle A, the process returns to step # 1. In this embodiment, the first set speed N1 is set to about 3.6 km / h,
About 5 km / h is set as the second set speed N2.

Thus, the turning control mechanism 37 constitutes the turning control means 44, the traction control means 45, and the mode setting means 48, and the respective means 44, 45, 48 operate as follows. That is, when the changeover switch 36 is pushed to output a command to turn off the control, the mode setting means 48 switches the turning control means 44 to the cutoff mode based on this command, and the changeover switch 36 operates in the first turning control mode. When the command is output, the mode setting means 48 switches the turning control means 44 to the first turning control mode based on the command, and when the changeover switch 36 outputs the command for the second turning control mode, based on the command, The mode setting means 48 switches the turning control means 44 to the second turning control mode.

The turning control means 44 controls the front wheel 1 in a straight-ahead steering state or a turning angle smaller than the set turning angle A in either of the first turning control mode and the second turning control mode. The steering angle sensor 3 in the steering state
4, the front wheel speed increasing device 20 and the pair of body steering brakes 32a, 32b are operated to be in the off state. In the first turning control mode, when the front wheel 1 is steered beyond the set turning angle A, the front wheel speed increasing device 20 is operated based on information from the turning angle sensor 34.
And the body steering brake 32a or 32b acting on the rear wheel 2 of the pair of body steering brakes 32a and 32b, which acts on the rear wheel 2, is operated to the entry side, and the driving speed of the front wheels 1 is reduced. The speed is made higher than the driving speed of the wheels 2, and the brake is applied to the rear wheels 2 inside the turning to make the aircraft turn slightly. In the state of the second turning control mode, when the front wheel 1 is steered to the predetermined turning angle A or more, the front wheel speed increasing device 20 and the body steering brake are controlled based on the information from the turning angle sensor 34. Only the front wheel speed increasing device 20 of 32a and 32b is switched to the entry side, and the drive speed of the front wheels 1 is made higher than the drive speed of the rear wheels 2 to make a small turn of the aircraft.

When the turning control means 44 is in the first turning control mode, if the speed V detected by the speed detecting means 47 is lower than the first set speed N1, the turning control means 44 sets the second turning control mode to the second turning control mode. In the case of the turning control mode, if the detected speed V detected by the speed detecting means 47 is lower than the second set speed N2, which is higher than the first set speed N1, the braking control unit 45 sets the speed detecting means 45, respectively. Based on the information from 47, the turning control means 44 is released from the towing operation, and the turning control means 44 moves the front wheel speed increasing device 20 and the body steering brakes 32a, 32b to the entrance side based on the information from the turning angle sensor 34. Enables switching operation. However, when the turning control means 44 is in the first turning control mode, if the speed V detected by the speed detecting means 47 is equal to or higher than the first set speed N1, the turning control means 44 performs the second turning control. In the state of the mode, if the speed V detected by the speed detecting means 47 is equal to or higher than the second set speed N2, the restraining means 45 applies the towing control means 44 to the turning control means 44 based on the information from the speed detecting means 47, respectively. To disable the turning control means 44 from switching the front wheel speed increasing device 20 and the body steering brakes 32a and 32b to the entrance side based on the information from the turning angle sensor 34.

That is, when the airframe that has reached the end of the work train is turned to the next work train, if the center distance between the work trains is relatively wide, the changeover switch 36 controls the turning control means 44 by the changeover switch 36. While switching to the two-turn control mode and keeping the traveling speed lower than the second set speed N2,
When the center interval between the work rows is relatively small, the turning control means 44 is switched to the first turning control mode by the changeover switch 36 and the traveling speed is set to the first set speed N.
The steering operation of the front wheels 1 is made to be equal to or more than the set turning angle A while keeping the steering angle to less than 1. Then, in the case of the second turning control mode, the turning control means 44 operates the front wheel speed increasing device 20 to switch from the off state to the on state, and the front wheel 1 is driven at a higher speed than the rear wheel 2. The aircraft can be turned with a small turning radius to quickly align with the next work row. First
In the case of the turning control mode, the turning control means 44 switches the front wheel speed increasing device 20 from the off state to the on state, and turns off the body steering brake 32a or 32b acting on the rear wheel 2 located inside the turning. The front wheel 1 is driven at a higher speed than the rear wheel 2 and the brake is applied to the rear wheel 2 inside the turning, so that the aircraft turns with a smaller turning radius and the next work line Can be positioned quickly.

For example, during operation, the vehicle is driven while the turning control means 44 is in the first turning control mode or the second turning control mode, and the front wheels 1 are steered to the set turning angle A or more to steer the body. Even if there is, when the turning control means 44 is in the first turning control mode and the aircraft is running at the first set speed N1 or more, the turning control means 44
In the turning control mode, when the aircraft is running at or above the second set speed N2, the front wheel speed increasing device 20 and the aircraft steering brakes 32a and 32b are turned on for the towing by the restraining means 45. The steering operation can be performed stably so as not to turn around the aircraft without being switched to the side.

As shown in FIG. 4, the turning control mechanism 37
Is provided with a mode selection unit 49. The mode selection unit 49 includes a power switch 50 for the turning control mechanism 37.
When the turning operation is performed, the mode provided by the turning control means 44 when the turning operation is first performed is provided to the turning control means 44 again. The information from the power switch 50 and the mode setting means 48 The operation is performed as follows based on a control flow inputted in advance.

That is, the EEPR which the microcomputer constituting the turning control mechanism 37 has as the storage unit 51
On the OM, 12 mode storage addresses (16th to 27th)
Address). That is, a plurality of addresses in an address area remaining after preferentially securing a storage unit necessary for performing various electronic controls such as a lifting / lowering control of the connection working device are used for mode storage. As shown in FIG. 7 to FIG.
A serial number for each write is written and stored in the bit by repeating 0 to 35, and mode information is written and stored in the lower 8 bits. The write serial numbers 0 to 35 are actually 0x
Write as a numerical value from 00 to 0x23. The information of the turning mode is 0x00, and the information of the second turning control mode is 0x00.
As 0F, the information of the first turning control mode is written as 0xF0. That is, each time the changeover switch 36 is pressed, the mode provided to the turning control means 44 based on the information from the mode setting means 48 is set to any one of the cutting mode, the second turning control mode, and the first turning control mode. And a predetermined write serial number 0 to 35 following the previous write serial number is added to the upper 8 bits of the address having the address number next to the address of the previously written address.
Are written in the lower 8 bits of the predetermined mode information 0x00, 0x0F, and 0xF0, respectively, following the previous write mode information. In the case where the power is turned off during the writing or the like, data which is not supposed to be written as shown by the write serial number of the 21st address in FIG. 9 or the mode information of the 23rd address in FIG. Writing errors may occur.

When the power switch 50 is turned on and operated, the write serial numbers of the upper 8 bits are verified in order from the beginning of the 16th to 27th addresses, and the write sequence of the address to be verified at present (referred to as the current address). The value of the number is the write serial number of the address to be verified immediately before this current address (referred to as the immediately preceding address; if the 16th address is the current address, the 27th address is the immediately preceding address). If the value is one more or less than 35, it is determined that the current address is the latest address and the data written to this address is the latest data. Also, as shown in FIG. 7, the value of the write serial number of the current address is 11 less than the value of the write serial number of the immediately preceding address, or FIG.
If the value of the write sequence number of the current address is 25 times greater than the value of the write sequence number of the immediately preceding address as shown in (1), it is determined that the immediately preceding address is the latest address and the data written to this address is the latest data. I do. In other cases, for example, when the value of the write serial number of the current address exceeds 35 as shown by the 21st address in FIG. 9, this is due to the writing failure at the previous write, and It is determined that the address is the latest address. Then, in this case, the write serial number that should have been written to the latest address is specified from the write serial number written to the immediately preceding address. That is, for example,
When any one of the write serial numbers 0 to 34 is written in the immediately preceding address, the write serial numbers 1 to 35 which are one more than this write serial number are specified as the write serial numbers to be written to the latest address. . When the write serial number 35 has been written to the immediately preceding address, it is specified that the write serial number 0 following this write serial number is the write serial number to be written to the latest address.

When it is possible to determine which address is the latest address, the mode information written in the lower 8 bits of the latest address is verified. If it corresponds to any one of the one turning control modes, it is determined that this mode is a mode to be provided for the turning control means 44. As shown by the 23rd address in FIG. 10, when the mode information written in the latest address is miswritten information and does not correspond to any of the cutting mode, the second turning control mode, and the first turning control mode, the latest address Is specified from the mode information written in the immediately preceding address, and the specific mode is determined to be a mode to be provided to the turning control means 44. That is, since the changeover switch 36 is operated to switch to the three types of modes of the turning mode, the second turning control mode, and the first turning control mode in that order, when the turning mode is written in the immediately preceding address, Means that the first turning control mode is written to the latest address when the second turning control mode is written and the turning mode is written to the latest address when the first turning control mode is written. It is determined that the mode is supposed to be the mode, and it is determined that the mode should be provided for the turning control means 44. When the mode to be provided to the turning control means 44 can be determined, a signal to be provided for the mode to the turning control means 44 is output to the mode setting means 48 so that the mode is prepared when the power is turned off first. The turning control means 44 is provided with a turning mode, a second turning control mode, or a first turning control mode. At the same time, the write serial number and the mode information specified from the write data of the immediately preceding address are written to the address where the writing has failed, so that there is no problem in the next reading.

That is, in the case where the power is turned off, the work is interrupted, and the work is restarted, for example, when the power is turned on,
The mode of the turning control means 44 is changed to the same mode as when the power is turned off by the operation of the mode selecting section 49, and it is not necessary to operate the changeover switch 36 again to set the mode.
The operation can be performed while operating the front wheel speed increasing device 20 and the body steering brakes 32a and 32b in the same turning mode, the first turning control mode, or the second turning control mode as before the suspension. By storing the power-off mode by using a plurality of storage units consisting of the 16th to 27th addresses, the number of times of rewriting of each storage unit can be reduced as compared with using only a single storage unit. This can be done while extending the service life of the storage unit as a whole, and specifying the predetermined mode to be prepared even in the event of a writing error and ensuring that the turning control means 44 is prepared.

[Other Embodiments] The present invention can be applied not only to agricultural tractors but also to rice transplanters and lawnmowers, and these vehicles are collectively referred to as work vehicles.

[Brief description of the drawings]

Fig. 1 Side view of the whole agricultural tractor

FIG. 2 is a drive transmission system diagram for traveling.

FIG. 3 is a sectional view of a front wheel speed increasing device.

FIG. 4 is a block diagram of a control system.

FIG. 5 is a flowchart of turning control.

FIG. 6 is a flowchart of turning control.

FIG. 7 is an explanatory diagram of writing in a storage unit.

FIG. 8 is an explanatory diagram of writing in a storage unit.

FIG. 9 is an explanatory diagram of writing in a storage unit.

FIG. 10 is an explanatory diagram of writing in a storage unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steering type wheel 2 Non-steering type wheel 20 Front wheel speed increasing device 32a, 32b Aircraft steering brake 36 Changeover switch 44 Turning control means 45 Checking means 47 Speed detecting means N1, N2 Set speed V Detected speed A Set break angle

Claims (5)

[Claims] A cutting state in which the driving speed of a traveling steerable wheel located at one of the front and rear ends of the fuselage is the same or substantially the same as that of a non-steerable traveling wheel located at the other end. A front wheel speed-up device that can be switched to an on state in which the driving speed of the directional wheels is higher than that of the non-steered wheels is provided, and when the steered wheels are steered beyond a preset turning angle, the front wheels A traveling control device for a work vehicle including a turning control device for automatically switching a speed increasing device to an entrance side to make a small turn of the aircraft, comprising a speed detecting device for detecting an actual traveling speed of the aircraft. If the speed detected by the speed detecting means is lower than the set speed, the turning control means enables the switching operation to the entrance side of the front wheel speed increasing device, and if the speed detected by the speed detecting means is equal to or higher than the set speed. The swing control hand Work vehicle travel control device that is provided with a restraining means for disabling the switching operation to the entrance side of the front wheel acceleration apparatus according. 2. A steering state in which the driving speed of a traveling steerable wheel located at one of the front and rear ends of the fuselage is the same or substantially the same as that of a non-steerable traveling wheel located at the other end. A front wheel speed-up device that can be switched to an engaged state in which the driving speed of the directional wheels is higher than that of the non-steered wheels, and a pair of body steering brakes that respectively act on the pair of left and right non-steered wheels When the steered wheels are steered beyond the set turning angle, the front wheel speed increasing device and the body steering brake acting on the non-steered wheels inside the turn are automatically turned to the entry side. A traveling control device for a work vehicle having a turning control means for performing a switching operation to make a small turn of the aircraft, comprising a speed detecting means for detecting an actual traveling speed of the aircraft, and a speed detected by the speed detecting means being set. If less than the speed, the turning control means To enable the switching operation of the front wheel speed-up device and the machine gymnastics countercurrent brake inlet side due,
If the speed detected by the speed detecting means is equal to or higher than a set speed, traveling of the work vehicle provided with a restraint means for disabling a switching operation of the front wheel speed increasing device and the body steering brake to the entrance side by the turning control means. Control device. 3. A steering state in which the driving speed of a traveling steerable wheel located at one of the front and rear ends of the fuselage is the same or substantially the same as that of a non-steerable traveling wheel located at the other end. A front wheel speed-up device that can be switched to an engaged state in which the driving speed of the directional wheels is higher than that of the non-steered wheels, and a pair of body steering brakes that respectively act on the pair of left and right non-steered wheels When the steered wheels are steered beyond the set turning angle, the front wheel speed increasing device and the body steering brake acting on the non-steered wheels inside the turn are automatically turned to the entry side. A first turning control mode in which the body is turned in a small turn by switching operation, and a front wheel speed increasing device of the front wheel speed increasing device and the body steering brake when the steerable wheels are steered more than the set turning angle. The second is to automatically switch only the entry side to the entry side and make the aircraft make a small turn A traveling control device for a work vehicle, comprising: a turning control unit that can be freely switched to a turning control mode, wherein the turning control unit includes a speed detecting unit that detects an actual vehicle traveling speed, and the turning control unit includes a first turning control. Mode and second
In any of the turning control modes of the turning control mode, if the speed detected by the speed detecting means is lower than the set speed, the turning control means switches the front wheel speed increasing device and the body steering brake to the entrance side. Enable
If the speed detected by the speed detecting means is equal to or higher than a set speed, traveling of the work vehicle having a front wheel speed increasing device and a check means for disabling a switching operation of a body steering brake to an entrance side by the turning control means. Control device. 4. The turning control means is operated by one push-button type changeover switch to switch between three types of modes, namely, control off, the first turning control mode and the second turning control mode, and the changeover switch is operated. 4. The travel control device for a working vehicle according to claim 3, wherein the mode is sequentially switched between the three modes each time the push operation is performed. 5. When the power is turned on, the turning control means is selected when the power is turned off among the control turning off, the first turning control mode, and the second turning control mode. 4. The apparatus according to claim 3, wherein the apparatus is configured to be in a mode in which the mode is changed.
Or the travel control device for a work vehicle according to 4.