JP2001245504A - Device for switching forward for backward travel of tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the turning action of a tractor at the end of a field and narrow a butt (remained untilled part of field) to improve the efficiency of the work. SOLUTION: A plurality of balk-detecting sensors 40a, 40b are disposed at different heights in the front body portion of a tractor 10 to sense the height of a levee 45. When a levee lower than a prescribed height is detected, the rotary working machine 12 is lifted to the prescribed height, and the body frame is backward moved only at a constant distance. When a levee higher than the prescribed height is detected, the rotary working machine 12 is lifted to a higher position than the prescribed height, and the body frame is backward moved only at a constant distance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / backward switching control device for a tractor, and more particularly to a forward / backward switching control device for automatically retreating a vehicle body at an end of a field.

[0002]

2. Description of the Related Art When performing a tilling operation by connecting a rotary work machine to a rear part of a vehicle body of a tractor, in order to prevent drag of the rotary work machine when turning at a field end, The rotary working machine is raised to a non-working position at a predetermined height. The part where the tractor turns is called a headland and an untiled part remains. At the final stage, the tractor reciprocates on the headland and eliminates the untiled part. When the headland is wide, the tractor cannot eliminate the untiled portion within two steps (ie, one reciprocation), and the number of work steps increases, and the efficiency deteriorates. In order to perform headland work efficiently, it has been attempted to set the tillage width of the work machine wide or to shorten the wheelbase of the vehicle body, but turning that is repeated several tens or more times in one field In operation, considerable skill and concentration are required to keep all headlands within two steps.

[0003] Therefore, there is a technical problem to be solved in order to improve the working efficiency by narrowing the headland while easily performing the turning operation of the tractor at the end of the field,
An object of the present invention is to solve this problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object. In a tractor in which a working machine is connected to a rear portion of a vehicle body, a height of a ridge is provided at a front portion of the vehicle body. A tractor forward / reverse switching control device provided with control means for changing the elevation of the work implement in accordance with the detection value of the detection means and for retreating the vehicle body by a predetermined distance; and In the tractor with the working machine connected to the rear, a means for sensing the height of the ridge is provided in front of the vehicle body, and the height of the working machine is changed according to the detection value of the sensing means,
It is another object of the present invention to provide a tractor forward / reverse switching control device provided with control means for retreating a vehicle body by a predetermined distance according to the rising height.

[0005]

An embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 3, reference numeral 10 denotes a tractor, and a rotary working machine 12 serving as a ground working machine is provided at a rear portion of the vehicle body of the tractor 10 via a link mechanism 11.
Are connected. In the vicinity of the driver's seat 13, a position lever 14, which is a means for setting the position of the work implement, a cultivation depth adjusting dial 15, which is a means for setting the amount of cultivation of the work implement, and the work implement is raised to a predetermined height when a turning operation of the vehicle body is detected. A turning control switch 16 for automatically ascending to the non-working position and performing a braking operation inside the turning, a forward / backward switching control switch 17 for raising the working machine and retreating the vehicle body by a certain amount when a row is detected at the edge of the field. Etc. are provided.
Rear wheels 19, 19 are provided on both left and right sides of the transmission case 18, respectively.
Is installed.

The link mechanism 11 comprises a top link 20 and left and right lower links 21 and 21. The distal ends of the left and right lift arms 22 and 22 are connected to the lower links 21 and 21 by lift rods 23 and a lift cylinder 24. When the lift arm 22 is rotated by the drive of, the lower links 21 and 21 move up and down via the lift rods 23 and 23. In this way, the rotary working machine 12 moves up and down around the distal ends of the lower links 21 and 21.

[0007] A lift arm angle sensor 25 is provided at the rotation base of the lift arm 22 as means for detecting the elevation position of the work machine. The lift arm angle sensor 25 detects the rotation angle of the lift arm 22. Then, the controller 50 calculates the elevation of the rotary working machine 12. A rear cover 27 is attached to the rear end of the main cover 26 of the rotary working machine 12 so as to be vertically rotatable.
The rotation angle of the rear cover 27 is detected by 8 and the controller 50 calculates the tillage depth of the rotary work machine 12.

A steering handle 30 is provided in front of the driver's seat 13 as a steering operation part of the vehicle body, and a forward / backward switching lever 31 and a work implement elevating lever 32 are provided near the steering handle 30. By operating the forward / reverse switching lever 31, the rear wheel 19
The driving force transmitted to the vehicle is reversed so that the traveling direction of the vehicle body can be selected. The lift cylinder 24 is driven by operating the work machine elevating lever 32, and the rotary work machine 12 continuously rises from the plowing work position to the non-working position, or from the non-working position to the plowing work position. It is formed so as to descend continuously.

Further, a shift lever 33 is provided at a lower front portion of the driver's seat 13 and left and right brake pedals 34, 34 which can be depressed independently of each other are provided. The rotation operation of the steering handle 30 is transmitted to the power steering steering unit 36, and pressure oil is supplied to the steering cylinder 37 in accordance with the rotation operation amount of the steering handle 30, and the steering is performed by the expansion and contraction operation of the steering cylinder 37. The front wheels 38, 38, which are wheels, turn. Reference numeral 39 denotes a steering angle sensor as means for detecting the turning operation of the vehicle from the amount of rotation of the steering handle 30.

Here, as means for detecting the height of the ridge in front of the vehicle body, a plurality of ridge detection sensors 40 having different mounting heights.
a and 40b are provided. The lower row detecting sensor 40a is configured to bend the downwardly hanging arm 41a forwardly and attach a contact portion 42a to a distal end thereof. When the contact portion 42a comes into contact with the ridge 45, the base end of the arm 41a The sensing section 43a provided in the section reacts to sense the ridge 45. Similarly, the upper ridge detection sensor 40b also has a contact portion 42b attached to the tip of the bent arm 41b.
5 when the contact portion 42b contacts the arm 41b.
Sensation part 43b provided at the base end of
5 is sensed. Incidentally, 46 is an engine, 47 is an engine speed sensor, and 48 is a PTO output sensor.

The hydraulic oil discharged from the main pump 60 is supplied through an L / C filter 61 to a lift cylinder 24 for lifting and lowering the work implement and a rolling cylinder 62 for horizontal control. The lift cylinder 24 is driven to expand and contract by outputting a control signal from the controller 50 to the ascending solenoid 51 or the descending solenoid 52 of the elevating control circuit 63. On the other hand, the hydraulic oil discharged from the sub pump 64 passes through the pressure reducing valve 65 to the power steering steering unit 36.
The hydraulic oil branched from the pressure reducing valve 65 is supplied to the PTO clutch 66, the forward / reverse switching clutch 67,
It is supplied to main speed changeover cylinders 68, 69 and left and right brake cylinders 70, 71.

A target value for the cultivation depth of the rotary work machine 12 is set by the cultivation depth adjustment dial 15, and the controller 50 calculates the elevation position of the rotary work machine 12 from the detection signal of the lift arm angle sensor 25. The rotation angle of the rear cover 27 is detected by the rear cover sensor 28 to calculate the plowing depth of the rotary work machine 12. Then, in order to maintain the rotation angle of the rear cover 27 at a predetermined angle corresponding to the target plowing depth set by the plowing depth adjustment dial 15, the ascending solenoid 51 or the descending solenoid of the electromagnetic control valve for driving the lift cylinder 24. The controller 50 outputs a control signal to the controller 52. Accordingly, the lift arm 22 pivots up and down, the rotary work machine 12 moves up and down, and the height of the rotary work machine 12 changes, whereby the rear cover 27 rotates, and the detection value of the rear cover sensor 28 changes to the target plowing depth. Is controlled to match.

When the turning control switch 16 is turned on, the turning operation of the vehicle body is detected by the controller 50 from the detection signal of the steering angle sensor 39, and when the turning operation is started, the turning solenoid 51 is turned on. A control signal is output to raise the rotary working machine 12 to the non-working position, and a control signal is output to the left brake solenoid 53 or the right brake solenoid 54 to perform a braking operation inside the turn.

On the other hand, when the forward / reverse changeover control switch 17 is ON, the controller 50 determines whether or not there is a ridge 45 in front of the vehicle body based on the detection signals of the ridge detection sensors 40a and 40b. That is, the tractor 10 plows to the vicinity of the edge of the field by traveling forward, and the ridge sensor 4
If only 0a detects the ridge 45, it can be determined that the ridge is a low ridge having a height less than the predetermined height. If both the upper and lower ridge detection sensors 40a and 40b detect the ridge 45,
It can be determined that the ridge is higher than a predetermined height. When the ridge detection sensor 40a or 40b detects the ridge 45,
A control signal is output from the controller 50 to the ascending solenoid 51 to raise the rotary work machine 12 to the non-working position, and a control signal is output to the reverse switching solenoid 56 to switch the transmission to the reverse position. Let it. Then, after retracting the vehicle a certain distance,
A control signal is output to the forward switching solenoid 55 to switch the transmission to the forward position again, so that the vehicle body can be turned.

Next, a control method of the forward / reverse switching control device will be described with reference to FIGS. According to the first aspect of the present invention, the rising height of the rotary work machine 12 is changed according to the detected height of the ridge 45. As shown in FIG. 4, the lower row detecting sensor 40a detects the row 45 (step 1).
01) If the upper row detecting sensor 40b does not detect the row 45 (Step 102), the detected row 45 is a low row having _a height less than the predetermined height Ha, and the rotary work machine 12 is relatively close to the ground. The height is raised to _a predetermined height Ha (step 103).

On the other hand, when both the lower ridge detection sensor 40a and the upper ridge detection sensor 40b detect the ridge 45, the detected ridge 45 is a high ridge having _a predetermined height Ha or more. It is raised to a high position H _b than the predetermined height H _a of 12 (step 104). And
Step 103 or step 104 to step 10
Proceed to 5, to connect the forward-reverse switching clutch 67 to the reverse side by exciting the reverse switching solenoid 56 retracts the vehicle body by a predetermined distance L _1. After the vehicle body is retracted by a predetermined distance L ₁ is a reverse switching clutch 67 prior to energizing the forward switching solenoid 55 connected to the forward side, a state which are capable of pivoting of the vehicle body.

Thereafter, if the steering wheel 30 is rotated by a predetermined angle or more, it is determined by the steering angle sensor 39 that the turning operation of the vehicle body has been started, and the turning control is executed. When turning control is executed,
After confirming that the rotary work machine 12 has been raised to the non-working position, the controller 50 operates the brake solenoid 53 or 54 on the inside of the turn to apply a one-side brake, and the front wheel 20 is accelerated to enable a small turn. At the same time, the electromagnetic control valve 35 provided between the power steering steering unit 36 and the steering cylinder 37 is switched to the offset position, the amount of hydraulic oil supplied to the steering cylinder 37 is increased, and the front wheel 38 is cut off. Make the angle change agile.
When the steering handle 30 is returned to the straight state, it is determined by the steering angle sensor 39 that the steering operation of the vehicle body has been completed, and the electromagnetic control valve 35 is switched to the normal position, and the steering cylinder is switched. The amount of hydraulic oil supplied to the front wheel 38 is reduced, and the change in the turning angle of the front wheel 38 becomes slow.

Next, according to the second aspect of the present invention, the height of the rotary working machine 12 is changed according to the height of the ridge 45 detected, and the retreat distance of the vehicle body is changed according to the height. I do. As shown in FIG.
When 0a senses the ridge 45 (step 201), raise the rotary working machine 12 to a predetermined height H _a of the above (step 202). Subsequently, when the upper row detecting sensor 40b does not detect the row 45 (Step 203), the detected row 45 is a low row having _a height less than the predetermined height Ha, and the process proceeds to Step 204 to excite the reverse switching solenoid 56. to connect the forward-reverse switching clutch 67 to the reverse side, to retract the vehicle body by a predetermined distance L _1. Then, the forward switching solenoid 55 is excited to connect the forward / reverse switching clutch 67 to the forward side, so that the vehicle can be turned. Thereafter, if the steering wheel 30 is rotated by a predetermined angle or more, the steering control described above is executed, and the vehicle body makes a small turn, and at this time, the rotary work machine 12 passes over the low ridge. That is, the vehicle body has the minimum turning radius.

Meanwhile, if it senses the top of the ridge detecting sensor 40b even furrow 45 at step 203, since the sensed ridges 45 is at least a high ridge predetermined height H _a, increasing the vehicle body than said predetermined distance L ₁ fall back. That is, the routine proceeds to step 205, the rotary working machine 12 also rotary working machine 12 to pivot the vehicle body remains elevated position at a predetermined height H _a is retracted to the distance L ₂ not in contact with the ridge 45. Thereafter, the turning control is executed in step 206 in the same manner as described above.
In step 205, the height of the rotary working machine 12 is changed in accordance with the height of the ridge 45, and the distance in which the vehicle body retreats is set in accordance with the height of the rotary working machine 12 in the rotary work. The distance may be changed to a minimum distance within a range where the machine 12 does not contact the ridge 45. Step 204
And in step 205, the controller 50 starts counting simultaneously with the reverse output, determines that the vehicle body is retracted by a predetermined distance L ₁ when preset time has elapsed, subsequently, be further set It shall determine that the vehicle body is retracted to the distance L ₂ when the time has elapsed.

Here, the above-mentioned ridge detection sensors 40a, 40
When the ridge 45 is detected at b, the controller 50 turns off the forward and reverse switching solenoids 55 and 56,
The forward / reverse switching clutch 67 is temporarily set to the neutral position. At this time, if the running speed of the vehicle body is high, the vehicle body may collide with the ridge 45 due to inertia. In order to prevent this, the controller 50 neutralizes the forward / reverse switching clutch 67 and simultaneously turns on the left and right brake solenoids 53 and 54 to apply the left and right brakes at the same time, thereby reliably stopping the vehicle body. Further, when the vehicle body retreats after sensing the ridge 45, a control signal is output to the left and right brake solenoids 53 and 54 to apply a weak brake, so that the vehicle body can slowly retreat.

The present invention can be variously modified without departing from the spirit of the present invention, and it is natural that the present invention extends to the modified one.

[0022]

According to the present invention, as described in detail in the above-described embodiment, the invention according to claim 1 allows the work machine to be lowered to a relatively low predetermined height when a low ridge below a predetermined height is detected. Raise the vehicle body by a certain distance to raise it, and when a high ridge that is higher than a predetermined height is detected, raise the work equipment to a higher position and retreat the vehicle body by a certain distance. Work equipment can be prevented from contacting the ridge during turning, while keeping the minimum distance required for the work.

When a low ridge having a height less than the predetermined height is detected, the work machine is raised to a relatively low height, the vehicle body is moved backward by a predetermined distance, and a high ridge having a height higher than the predetermined height is detected. At this time, the working machine is raised to the low height, and in this state, the vehicle body is largely retreated by a distance that does not make contact with the ridge when turning, so that the turning radius becomes the minimum turning radius according to the height of the ridge.

In this way, it is possible to improve the working efficiency by narrowing the headland while easily performing the turning operation at the end of the field.

[Brief description of the drawings]

 The figure shows an embodiment of the present invention.

FIG. 1 is a side view of a tractor.

FIG. 2 is a block diagram of a control system.

FIG. 3 is a hydraulic circuit diagram.

FIG. 4 is a flowchart of forward / reverse switching control according to the first embodiment;

FIG. 5 is a flowchart of forward / reverse switching control according to the invention of claim 2;

[Explanation of symbols]

 Reference Signs List 10 Tractor 12 Rotary work machine 40a, 40b Row sensing sensor 50 Controller 51 Ascending solenoid 55 Forward switching solenoid 56 Reverse switching solenoid

Continued on the front page F-term (reference) 2B043 AA04 AB15 BA02 BB01 BB03 EA02 EA04 EA16 EA32 EA37 EB07 EB08 EB10 EB14 EB22 EC03 EC13 EC14 ED05 ED12 ED14 ED15 ED22 ED23 2B304 KA12 LA02 MC03 MD03 MD03 MB03 PD03 PD19 QA03 QA04 QA12 QA22 QA30 QB02 QB13 QB30 QC03 QC06 QC12 QC14 QC17 RA02 RA09

Claims (2)

[Claims] 1. A tractor in which a work machine is connected to a rear part of a vehicle body, a means for sensing a height of a ridge is provided at a front part of the vehicle body, and a height of the work machine is raised according to a detection value of the detection means. And a control means for changing the vehicle speed and moving the vehicle backward by a predetermined distance. 2. A tractor in which a working machine is connected to a rear part of a vehicle body, a means for sensing the height of the ridge is provided in front of the vehicle body, and the height of the working machine is raised according to a detection value of the sensing means. A tractor forward / reverse switching control device, further comprising control means for changing the vehicle body and retreating the vehicle body by a predetermined distance in accordance with the rising height.