JP2002145103A - Turn controller for crawler type work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent engine failure caused by decrease in an engine speed when turning at a low engine speed while traveling at a high speed, prevent engine failure caused by increase in a traveling load even when turning on a soft farm field and enable a smooth turn in spite of a load such as dirt spattered onto a crawler, in a crawler type work vehicle having a rotation operation type steering wheel and operating braking equipment on one side when turning. SOLUTION: In the crawler type work vehicle, when a main transmission and a sub-transmission are shifted to a high-speed position and the vehicle is traveling at a predetermined engine speed or less, an actuator is operated to increase the engine speed if the steering wheel angle of a steering wheel reaches a predetermined angle or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning control device for a crawler type work vehicle, and more particularly to a turning control device for turning with a single brake during traveling at a low engine speed. It is.

[0002]

2. Description of the Related Art
For a working vehicle such as a tractor or a combine, there are a steering wheel and a sensor for detecting the rotation angle, an actuator for adjusting the engine speed, a sensor for detecting the engine speed, and a sensor for detecting the running speed of the vehicle. A right and left crawler-type traveling device driven by receiving an output from a differential device; and a brake device for independently braking the rotation of the crawler-type traveling device in the left and right directions, according to a rotation operation angle of the steering handle. There is known an apparatus in which the braking force of a brake device inside a turn is increased or decreased.

However, in a state where the engine is running at a low speed and the vehicle is running at a high speed, the rotation of the crawler on one side is reduced when the vehicle is turned by operating the steering wheel. When the brake device on the inside of the turn is operated, the engine speed may further decrease and the engine may stall. In addition, when the soil is soft at the time of work in the field, the running load at the time of turning of the vehicle increases, which may cause engine stall. Further, it is necessary to smoothly turn against a load such as soil and mud applied to the crawler at the time of turning.

Therefore, in a crawler-type work vehicle provided with a rotating steering wheel and a brake device on one side is operated at the time of turning, when the engine rotates at a low speed and runs at a high speed. In addition, the engine is prevented from stalling due to a decrease in the number of revolutions of the engine, and is prevented from stalling due to an increase in running load even when turning in a soft field, and is smoothly turned with respect to a load such as mud on the crawler. Therefore, a technical problem to be solved arises in order to solve the problem, and an object of the present invention is to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object, and includes a steering handle 19, a sensor 50 for detecting the rotation angle, and an actuator 61 for adjusting the number of revolutions of the engine. And sensors 57 and 58 for detecting the traveling speed of the vehicle, left and right crawlers 16 driven by receiving an output from the differential device 25, and a brake device 33 for braking the rotation of the crawlers 16 independently on the left and right. In a crawler-type work vehicle provided with a brake device 33 on the inside of the turn that is operated in conjunction with a rotation operation angle of the steering handle 19, the rotation speed of the engine is less than a predetermined rotation and the traveling speed of the vehicle is lower than a predetermined rotation speed. When the rotation angle of the steering handle 19 reaches a predetermined angle or more at a predetermined speed or more, the actuation is performed. A turning control device for a crawler-type work vehicle including a control means 70 for operating the eater 61 to increase the number of rotations of the engine, and when the rotation operation angle of the steering handle 19 reaches a predetermined angle or more, the rotation of the vehicle is stopped. A turning control device for a crawler-type work vehicle, comprising a control means 70 for changing the rotation speed of the engine to a speed increasing side in accordance with an increase in the operation angle, a steering handle 19 and a sensor 50 for detecting the rotation operation angle; , The left and right crawlers 16 driven in response to the output from the differential device 25, an actuator for reversing the rotation of the crawlers 16, a brake actuator for braking the left and right crawlers independently of each other, brake pedals 28, 29 And sensors 55 and 56 for detecting the pedal operation. In a crawler-type work vehicle in which the brake device 33 inside the turn is operated in conjunction with the turning operation angle, the rotation operation angle of the steering handle 19 reaches a predetermined angle or more and the brake pedal operation inside the turn is performed. An object of the present invention is to provide a turning control device for a crawler-type work vehicle including a control unit 70 that reverses the crawler 16 inside the turning when detected.

[0006]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a crawler-type tractor 10 as an example of a working vehicle, in which a drive sprocket 12 is mounted on a rear axle 11.
A driven sprocket 14 and a rolling wheel 15 are pivotally connected to a track frame 13 that supports and rotates the crawler 2, and a crawler 1 is mounted between the driving sprocket 12 and the driven sprocket 14 and the rolling wheel 15.
6 and the front end of the track frame 13 is fixed to the vehicle frame 17 to form a crawler type traveling device C. Further, a steering wheel 19 of a rotary operation type is provided in front of the driver's seat 18. Then, the steering handle shaft 20 is inserted into the steering handle column 27, and a steering operation device 40 described later is mounted at a base end thereof.

FIG. 2 is a diagram showing a power transmission path of the tractor 10, and the rotational power of the engine 21 is controlled by the main clutch 2.
2, the transmission is shifted to any one of the first to third forward speeds or the reverse by the main transmission 23, and further shifted to the high or low speed position by the auxiliary transmission 24, and then the rear differential Device 25 and PT
The power is transmitted to the O-shaft 26.

As shown in FIGS. 2 and 3, a differential lock device 31 is attached to an output shaft 30 of the rear differential device 25.
And a small diameter transmission gear 32 and a disc brake device 33, and a counter shaft 3 provided in parallel with the output shaft 30.
4, a large-diameter transmission gear 35 is fixedly engaged with the small-diameter transmission gear 32. Therefore, the rotation of the output shaft 30 is reduced and transmitted to the counter shaft 34, and the counter shaft 34
Forward / reverse rotation clutch device 36 and planetary gear mechanism 37
As a result, rotation in either the forward direction or the reverse direction is selected while being further decelerated, and transmitted to the input shaft 38 provided coaxially with the counter shaft 34. And the input shaft 38
Is transmitted to the rear axle 11 via the intermediate shaft 39, and the crawler 16 is driven. Here, since the disc brake device 33 is disposed so as to be wrapped between the transmission gear 35 and the forward / reverse clutch device 36, the space between the transmission gear 35 and the forward / reverse clutch device 36 can be effectively used. , The output shaft 30 and the counter shaft 34
And the transmission gear mechanism to the rear axle 11 can be made compact.

FIGS. 4 and 5 show a steering operation device 40.
And a holding tool 42 is attached to the bracket 41 bent into an L shape.
And a steering shaft 43, which is a drive shaft that rotates in response to the operation of the steering handle 19, is pivotally attached to the holder 42, and a distal end of the holder 42 is attached in parallel with the steering shaft 43. A cam shaft 45 as a drive shaft is pivotally mounted, and a reduction gear mechanism is provided between the steering shaft 43 and the cam shaft 45. A pinion gear 44, which is a driving gear of the reduction gear mechanism, is fixed to the steering shaft 43, and a sector gear 46, which is a driven gear of the reduction gear mechanism, is fixed to the camshaft 45. To engage. Further, a pin 47 is erected on the upper surface of the sector gear 46.

On the other hand, a steering angle sensor 50 composed of a potentiometer is mounted on the upper surface of the bracket 41, and a sensor arm 51 of the steering angle sensor 50 is protruded from the lower surface of the bracket 41. The pin 47 of the sector gear 46 is locked. When the steering handle 19 is in the neutral position, that is, when the pinion gear 44 of the steering shaft 43 is located substantially at the center of the circumference of the sector gear 46,
The mounting position of the sensor arm 51 or the initial value of the detection signal is adjusted so that the steering angle sensor 50 detects the rotation operation angle of 0 °.

Next, a turning control device of the crawler working vehicle will be described with reference to FIGS. As described above, the turning angle of the steering handle 19 is detected by the steering angle sensor 50, and the controller 70 controls the brake solenoid 6 inside the turning in accordance with the turning angle.
3 or 65 to output a control current to the brake cylinder 6
4 or 66 is driven to operate the disc brake device 33 inside the turn. Thus, the drive speed of the crawler 16 inside the turn is reduced, and the vehicle turns. Also,
The depression amount of the accelerator pedal 52 is detected by the accelerator pedal position sensor 54, and the controller 70 drives the actuator 61 according to the depression amount of the accelerator pedal, adjusts the rack position of the throttle governor 62, and controls the rotation speed of the engine 21. Increase or decrease. These actuators 6
1 and the controller 70 constitute control means for increasing the engine speed. The engine speed is detected by an engine speed sensor 53.

On the other hand, when the left and right foot-operated brake pedals 28 or 29 are depressed, the brake arm 48 or 49 is rotated via the link mechanism, and either the left or right disc brake device 33 is operated to rotate the crawler 16. Braking. The depression operation of the brake pedals 28, 29 at this time is detected by the brake pedal sensors 55, 56. Further, the shift position of the main transmission 23 is detected by the main transmission shift position sensor 57 and the shift position of the auxiliary transmission 24 is detected by the auxiliary transmission shift position sensor 58, so that the vehicle is in a high-speed running state. It is possible to detect whether the vehicle is traveling at a low speed or in a low-speed traveling state. Reference numeral 59 denotes a spin turn control switch. As will be described later, by turning on and off the spin turn control switch 59, it is possible to select whether or not to switch the rotation direction of the crawler type traveling device C inside the turn to reverse rotation. .

As shown in FIG. 7, the main shift position and the sub shift position are at the high speed position based on the detection values of the main shift position sensor 57 and the sub shift position sensor 58 (step 1).
2) When the detected value of the engine speed sensor 53 is running at a predetermined speed or less (step 3), the vehicle is running straight on the road at high speed.
In such a state, when the steering wheel 19 is rotated and the detected value of the steering angle sensor 50 reaches a predetermined angle or more (step 4), the controller 70 operates the actuator 61 to operate the throttle governor. By adjusting 62, the engine speed is increased to prevent engine stall (step 5).

At this time, if an actuator which operates in a stepwise manner, such as a stepping motor, is used as the actuator 61, if the steering wheel 19 is operated during the low engine speed and high speed running, the steering angle is reduced. Accordingly, the operation amount of the actuator 61 is adjusted, and the engine speed can be changed to the speed increasing side with an increase in the rotation operation angle of the steering handle 19, so that more effective control is performed. When the engine is running at a low rotation speed and at a high speed, the rotation speed of the engine 21 is stored in the controller 70 in advance, and when the rotation speed of the engine is about to decrease due to the one-brake operation during the turning of the vehicle, the actuator 61 is turned off. The engine may be operated so as to maintain the stored engine speed.

Here, as shown in FIG. 2, when the vehicle is turning, a signal is output from the controller 70 to one of the left and right brake solenoids 63, 65, and the proportional valve opens to drive the brake cylinders 64, 66. However, the brake cylinders 64 and 66 are filled with hydraulic oil and the brake arms 48 and
There is a time lag before 49 is pulled, and a response delay to the steering operation may occur. Therefore, a slight output from the proportional valve is applied to the brake cylinders 64, 66, and the cylinders of the brake cylinders 64, 66 are filled with hydraulic oil in advance. As a result, the response delay of the brake device 33 can be eliminated. Note that the response delay is not so noticeable when the traveling speed of the vehicle is low, and the response delay increases as the traveling speed increases, so that the detection values of the main shift position sensor 57 and the auxiliary shift position sensor 58 are used. Accordingly, the standby pressure may be applied to the brake cylinders 64 and 66 during straight running only when the shift position of the vehicle is at the high speed position.

When the spin turn control switch 59 is turned on, as shown by a solid line in FIG. 8, for example, during a right turn, the brake current inside the turn increases with an increase in the rotational operation angle of the steering wheel. and will, when the rotational operation angle has passed the position P _S reaches a predetermined angle,
The rotation direction of the crawler type traveling device C is switched to the reverse rotation while weakening the brake current, so that the left and right crawlers 16, 16
Are driven in opposite directions, respectively. At this time, the current of the right brake solenoid is reduced to prevent the drive torque from escaping to the lighter side of the load on either the left or right due to the differential action of the rear differential device 25, and as shown by the two-dot chain line, Increase the current of the brake solenoid.

However, when the spin turn is performed, the field becomes rough, and there is a case where it is not necessary to execute the spin turn more than necessary. If so, the spin turn control switch 5
By turning off the motor 9, the brake current inside the turn is maintained at a high current even after the rotation operation angle has passed the _PS position, as shown by the dashed line, and the drive of the crawler type traveling device C inside the turn is performed. Is stopped and the brake current on the opposite side is controlled not to increase, and no spin turn is performed.

The spin-turn control switch 59
The left and right brake pedals 28 and 29
Brake pedal sensors 55 and 56
When the steering wheel 19 is turned, the brake pedal 28 or 29 on the inside of the turn is depressed once and released, thereby switching the rotation direction of the left and right crawler type traveling device C to the reverse direction to perform the spin turn. May be configured to be executed. Then, in conjunction with the operation of returning the steering handle 19 to the neutral position, the execution of the spin turn is stopped and the control returns to the normal brake control. Although not shown, the start of the spin turn may be selected by a foot-operated switch.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0020]

According to the present invention, as described in detail in the above embodiment, the invention according to the first aspect of the present invention relates to a crawler type working vehicle in which the engine speed is less than a predetermined speed and the running speed of the vehicle is lower than a predetermined speed. When the rotation angle of the steering wheel reaches a predetermined angle or more when the speed is equal to or more than the predetermined speed, the actuator is operated to increase the engine speed. Even if the load increases, engine stall due to a decrease in the engine speed can be prevented.

According to the second aspect of the present invention, the number of rotations of the engine is changed to a speed increasing side in accordance with an increase in the rotational operation angle of the steering handle. Therefore, in addition to the effect of the first aspect, More detailed control can be performed.

Further, the invention according to claim 3 is characterized in that when the rotation operation angle of the steering handle reaches a predetermined angle or more and the brake pedal operation inside the turning is detected.
Since the crawler inside the turning is reversely rotated, the crawler inside the turning can be reversely rotated only when the operator feels it necessary according to the work condition of the mud or the like on the crawler, thereby achieving a smooth turning.

[Brief description of the drawings]

 The figure shows an embodiment of the present invention.

FIG. 1 is a side view of a crawler type tractor.

FIG. 2 is a diagram showing a power transmission path of a tractor.

FIG. 3 is a sectional view showing a configuration from a rear differential device to a rear axle.

FIG. 4 is a plan view of the steering operation device.

FIG. 5A is a front view of a steering operation device. (B) Side view of the steering operation device.

FIG. 6 is a block diagram of a turning control system.

FIG. 7 is a flowchart of turning control.

FIG. 8 is a graph showing a change in a rotation operation angle of a steering wheel and a brake current.

[Explanation of symbols]

 Reference Signs List 10 Tractor 19 Steering handle 25 Rear differential device 33 Disc brake device 50 Steering angle sensor 53 Engine speed sensor 57 Main speed shift position sensor 58 Sub speed shift position sensor 61 Actuator 62 Throttle governor 70 Controller

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor: Masayuki Takahashi 1-Family, Yasura, Tobe-cho, Iyo-gun, Ehime Pref. JJ10 JJ17 JJ22 JJ23 JJ37

Claims (3)

[Claims] 1. A steering wheel 19 and a sensor 50 for detecting a rotation angle of the steering wheel 19, an actuator 61 for adjusting an engine speed, sensors 57 and 58 for detecting a running speed of a vehicle, and an output from a differential device 25. The left and right crawlers 16 are driven in response to the rotation, and a brake device 33 that brakes the rotation of the crawlers 16 independently of the left and right is provided. In a crawler-type work vehicle that is operated, when the rotation speed of the engine is equal to or less than a predetermined rotation and the traveling speed of the vehicle is equal to or more than a predetermined speed, the rotation operation angle of the steering handle reaches a predetermined angle or more. Control means 70 for operating the actuator 61 to increase the engine speed. A turning control device for a crawler-type work vehicle, characterized in that: 2. A control means 70 for changing the number of revolutions of the engine to a speed increasing side in accordance with an increase in the rotation operation angle when the rotation operation angle of the steering handle 19 reaches a predetermined angle or more. The turning control device for a crawler-type work vehicle according to claim 1. 3. A left and right crawler 16 driven by receiving an output from a differential device 25.
An actuator for reversing the rotation of the crawler 16, a brake actuator for braking the rotation of the crawler independently of right and left, brake pedals 28 and 29, and sensors 55 and 56 for detecting the operation of the pedal. In the crawler type work vehicle in which the brake device 33 inside the turning is operated in conjunction with the rotation operation angle of the handle 19, the steering handle 1
9. A crawler-type work vehicle according to claim 9, further comprising control means for reversing the crawler inside the turn when the rotation operation angle of the turn reaches a predetermined angle or more and the brake pedal operation inside the turn is detected. Control device.