JPH104701A - Dashing preventive controller for tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dashing preventive controller for preventing such a dashing action of a tractor that in a field of hard soil, the tractor mounted with a freely liftable rotary working machine dashes by a reaction force of the rotary teeth owing to digging resistance of the ground when the rotary working machine descends to the ground at the time when the operation is started or a swing action comes to end. SOLUTION: This tractor comprises a rotary working machine connected freely liftably on the rear part of the tractor body to an engine 1 mounted on the body, a body-to-ground speed sensor for detecting actual speed of the tractor and a brake unit 6 for barking the rear wheels 5R on the tractor body, a running system L1 for driving the rear wheels 5R and a working machine system L2 for driving the rotary working machine both of which receive rotating power branched from the engine, a clutches 7, 8 that independently control the rotary driving power to either one of both the systems, and a control unit that interrupts the rotary driving power for the working machine system and operates the brake unit 5 to work when the sensed speed exceeds a preset level in descending operation of the working machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for preventing a tractor from dashing.

[0002]

2. Description of the Related Art Conventionally, when performing a field work using a tractor having a rotary claw, such as a rotary work machine, having a rotating claw mounted thereon so as to be able to ascend and descend, the work machine is lowered and landed on soil at the start of work or at the end of turning. Then, in the case of a hard field, a dashing phenomenon in which the tractor jumps forward due to the reaction force due to the excavation resistance of the rotating claw sometimes occurs. To deal with this dashing phenomenon, Japanese Patent Application Laid-Open No. 6-227275 discloses a tractor that locks the front and rear wheel drive system for a certain period of time and stabilizes the vehicle body in a four-wheel drive state when there is an output of lowering the work implement. Techniques such as a control device are shown.

[0003]

However, in the field, hard and soft parts are partially scattered.
According to the technology disclosed in the above publication, when a control switch for operating the four-wheel drive control device is turned on, when there is a lowered output of the work machine, the work machine is always switched to the four-wheel drive state. However, there is a problem in that a transmission shock occurs when the 4WD is switched, which hinders the steering operation of the steering wheel such as the subsequent alignment.

For this reason, there has been a demand for a technique for appropriately detecting the dashing phenomenon even in the same field and reliably preventing the dashing phenomenon.

[0005]

According to the present invention, the following measures are taken in order to address the above-mentioned problems. That is, a working machine 3 having rotating pawls 2... At the rear of a vehicle body on which the engine 1 is mounted can be connected to be able to move up and down. The vehicle body has a vehicle speed sensor 4 for detecting the actual vehicle speed, and wheels 5R and 5R.
And a traveling system L for driving the wheels 5R with the rotational power of the engine 1.
1 and a tractor provided with clutch mechanisms 7 and 8 for branching to a working machine system L2 for driving the rotating claws 2... If the actual vehicle speed detected by the vehicle speed sensor 4 exceeds a preset vehicle speed, a control unit 9 is provided to cut off the rotational power of the work machine system L2 and activate the brake devices 6.6. And a tractor anti-dashing control device.

[0006]

As described above, since the actual vehicle speed of the tractor is detected by the vehicle speed sensor 4 when the work implement 3 descends and lands, the situation in which the dashing phenomenon occurs even in the same field is appropriately determined. As a result, it is possible to eliminate a shock due to unnecessary control operation as described in the above publication. Further, when the detected actual vehicle speed exceeds the set vehicle speed, the power of the work machine system L2 is cut off and the brake devices 6.6 of the traveling system L1 are operated. It can be reliably prevented when a phenomenon occurs.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tractor (hereinafter, tractor 10) equipped with a control device of the present invention will be described below with reference to the drawings. The tractor 10 includes a clutch housing, a front transmission case 13
F and the rear transmission case 13R are integrally connected to form a main part of the vehicle body. A pair of left and right front wheels 5F, 5F is provided at a front portion of the vehicle body, and a pair of left and right rear wheels 5
R · 5R, the rotational power of the engine 1 is appropriately decelerated by a transmission (forward / reverse switching device 14, main transmission 15, sub-transmission 16) in the two transmission cases 13F / 13R, and the rear wheels 5R · 5R are provided. To the front wheels 5F and 5F via the front wheel drive transmission device 17 to travel. A handle post 18 is provided behind the bonnet 11, and a handle 19 is provided above the handle post 18, and the front wheels 5F and 5F are turned by operating the handle 19. Further, a working machine lifting / lowering one-touch lever 20 </ b> R is provided to protrude from a side surface of the handle post 18. A work implement lift switch 20S is provided at the base of the work implement lift one-touch lever 20R, and the on / off operation of the switch 20S raises or lowers a lift arm 33, which will be described later, within a set angle. Has become.

A floor 21 is provided above the center of the vehicle body, and a seat 22 is provided above a rear portion of the floor 21. Fenders 23 are provided on both sides of the seat 22 so as to cover the rear wheel 5R from the front to the upper side. Between the seat 22 and the fender 22, a control switch 24 for turning on and off the anti-dashing control device, and a lifting / lowering position of the working machine Is provided. A potentiometer 25S is provided at the rotation base of the position lever 25R, and the lift arms 33 are rotated according to the detected angle. In addition, a controller 9 as a control unit is provided near the rotation base of the position lever 25R. A left and right brake pedal (not shown) and a clutch pedal 27P are provided below the handle post 18 and above the floor 21, and a limit switch 27S is provided at a rotating portion of the clutch pedal 27P.

A vehicle speed sensor 4 for detecting an actual vehicle speed is provided at a lower portion of the vehicle body and emits ultrasonic waves toward the ground surface.
The reflected wave is detected. Then, the detection is transmitted to the controller 9. A PTO shaft 30 protrudes from the rear surface of the rear transmission case 13R, and a cylinder case 32 containing a main cylinder 31 for lifting and lowering the work implement is provided on the rear upper surface of the case 13R. Thus, the lift arms 33 are vertically rotated. Hydraulic oil is supplied to or discharged from the main cylinder 31 by switching the oil passages of the ascending switching control valve 37A and the descending switching control valve 37B, which are switched by the energization of the controller 9. It is configured to expand and contract. A lift arm angle sensor 33S for detecting the rotation angle is provided at the rotation base of the lift arms 33.

Next, the work implement coupling mechanism will be described. A three-point link mechanism comprising a top link 34 and lower links 35 is provided at the rear of the rear transmission case 13R, and the lift arms 33 and 33 and the lower link are provided. 3
5 and 35 are connected by lift rods 36 and 36, respectively. Thereby, the work machine 3 mounted on the three-point link mechanism
Is 3 due to the expansion and contraction of the piston of the main cylinder 31.
It can be moved up and down via a point link mechanism.

The working machine having the rotating claws is the rotary working machine 3, which is connected to the tractor 10 via the three-point link mechanism, and the tractor 10 performs the tilling work while towing the tractor. The rotational power of the engine 12 is reduced by the PTO shaft transmission 52 in the transmission case 13F and the rear transmission case 13R and transmitted to the PTO shaft 30. Further, the rotational power of the PTO shaft 30 is transmitted to the rotary working machine 3 via the transmission shaft 42 and transmitted to the rotation shaft 43 to which the rotating claws 2 are attached.

The structure of the transmission mechanism of the tractor 10 will be described with reference to FIG. The path of the rotational power extracted from the engine 1 is branched into a traveling system L1 that drives the front and rear wheels 5F and 5R by the main clutch 7 and a working machine system L2 that drives the PTO shaft 30. The working machine system L2 is driven by the gear system 50 provided on the output shaft 53 of the engine 1 to drive the traveling system L2.
1, the PTO shaft 30 is rotated via the PTO shaft drive clutch 8 and the PTO shaft transmission 52. The PTO shaft drive clutch 8 is turned on / off by switching the switching control valve 51, and the switching control valve 51 is controlled by energization of the controller 9. Also, PT
The O-axis transmission 52 is configured to manually select a gear combination using a gear-type transmission (not shown).

The traveling system L1 is configured to transmit the rotational power of the engine 12 to the forward / reverse switching device 14 by pressing the main clutch 7 and further to the main transmission device 15 and the auxiliary transmission device 16 in that order. The rotational power output from the auxiliary transmission 16 is transmitted through the rear wheel differential mechanism 44 to the rear wheel 5.
It is configured to be branched into a path for driving the R · 5R and a path for driving the front wheels 5F / 5F via the front wheel drive transmission device 17 and the front wheel differential mechanism 45. A gear rotation sensor 48 is provided on the side of a gear 47 provided between the auxiliary transmission 16 and the rear wheel differential mechanism 44, and the gear rotation sensor 48 is connected to the controller 9. Thus, the theoretical vehicle speed when the friction in the field is ignored can be obtained from the rotation speed of the gear 47, each gear ratio up to the rear wheel 5R, and the system of the rear wheel 5R. Front wheel drive transmission device 57
When the double speed clutch 55 or the constant speed clutch 56 is connected by energization by the controller 9, the rotation speed of the front wheel 5F is increased when the double speed clutch 55 is connected, and when the constant speed clutch 56 is connected, the front wheel 5F And the rear wheel 5R are driven at substantially the same rotational speed.

The brake devices 6, 6 are provided on the left and right extensions of the drive shaft 59, and are operated by a method in which an operator steps on the left and right brake pedals, and a method in which the controller 9 controls the proportional pressure control valve 63L. -There is a method to open the 63R and operate the brake cylinder. In the former case, the left and right brake pedals are connected to a brake disc 28 provided on the rear axle case 13R via a link mechanism (not shown) such as a rod, and the brake disc 28 is crimped by depressing the pedal. The device 6.6 operates. In the latter case, a mechanism is provided in which the piston of a brake cylinder provided in the link mechanism is expanded and contracted by energization of the controller 9, and the link mechanism is pushed and pulled to crimp the brake disc 28.

The hydraulic path of the tractor will be described with reference to FIG. 3. The hydraulic oil sent from the pump P1 is sent into the main cylinder 31 by a switching operation of a switching control valve 37A for raising the working machine. Switching control valve 37 for machine down
It is opened to the tank T by the switching operation of B. The hydraulic oil sent from the pump 2 passes through the pressure reducing valve,
When the switching control valve 51 for transmitting the PTO shaft is switched, it is sent to the PTO shaft drive clutch 8 and further the proportional pressure control valve 63
It is configured to be fed to the left and right brake cylinders by opening R · 63L. In addition, this operating pressure is used to
Is detected.

The controller 6 has a CPU as a central processing unit, a ROM for storing a anti-dashing control program, a RAM for temporarily storing sensor values, and the like. A control switch 24, a work implement elevating switch 20S, a potentiometer 25S, a lift arm angle sensor 33S, a vehicle speed sensor 4, a gear rotation sensor 48, and a clutch pedal limit switch 27S are connected. Proportional pressure control valve 63 for operating each brake device
The solenoid of 63, the solenoids of the switching control valve 37A for raising and the switching valve 37B for lowering of the main cylinder 31, and the solenoid of the switching control valve 51 for turning on / off the PTO shaft drive clutch 8 Connected.

Regarding the flow of the anti-dashing control device,
This will be described with reference to the flowchart shown in FIG. First S
In TEP1, with the start of the engine 1 of the tractor 10,
The states of the switches and sensors are read. And S
In TEP2, the controller 9 detects whether the work implement 3 has been lowered by the work implement elevation one-touch lever 20R or the position lever 25R at the start of work. When this operator's lowering operation is detected, S
Proceeding to TEP3, the controller 9 sets the gear rotation sensor 4
The gear speed is detected from 8 to calculate the theoretical vehicle speed. After setting the upper limit vehicle speed even faster than the theoretical vehicle speed in STEP4, the work implement descending output is performed in STEP5. Then S
At STEP 6, the actual vehicle speed is detected from the vehicle speed sensor 4.
In STEP 7, the actual vehicle speed is compared with the set upper limit vehicle speed, and if the actual vehicle speed exceeds the upper limit vehicle speed, STEP 8
Proceed to. In STEP 8, the worker's clutch pedal 27
It is determined whether or not the P limit switch 27S is turned on. If YES, it is determined that the worker has performed an avoidance operation when a dashing phenomenon occurs, and the process proceeds to STEP9, where the switching control valve 51 is energized and the PTO shaft is turned on. The drive clutch 8 is disengaged, and in STEP 10, the proportional pressure control valves 63R and 63
L is energized to simultaneously operate the left and right brake devices 6,6. When the determinations in STEPs 7 and 8 are NO,
It is determined that the dashing phenomenon has not occurred, and the process returns.

As described above, the theoretical vehicle speed obtained from the rotation speed of the internal gear is compared with the actual vehicle speed when the working machine 3 having the rotary pawl 2 is lowered and landed, and the clutch operation of the worker is detected. Since the control devices 6 are sometimes activated, when the dashing phenomenon occurs, it is reliably detected, the rotation of the rotary claws 2 is stopped at the time of the detection, and the braking device for the left and right rear wheels 5R, 5R is detected. Since the configuration is such that 6.6 is operated at the same time, jumping out can be reliably prevented.

As another embodiment of setting the upper limit vehicle speed, a shift operation lever or a PTO shaft shift lever is provided with a detection sensor for detecting a shift position, and the upper limit vehicle speed is automatically adjusted by adjusting the combination of the shift positions. May be set manually.
As another embodiment of the method of setting the upper limit vehicle speed, FIG.
As shown in the flowchart of FIG. 2, in STEP2, the ascent operation of the work implement 3 is detected.
Then, the vehicle speed during the tilling operation is detected and stored, and the STE
At P4, an upper limit vehicle speed is set according to the vehicle speed, and STEP
5, the work machine 3 may be configured to perform a rising output. In this case, the work machine lowering operation is detected in STEPs 6 and 7,
After output of the work machine is lowered, in STEP8, the actual vehicle speed is compared with the upper limit vehicle speed based on the vehicle speed detected during the tilling operation.

Thus, it is possible to eliminate an error between the above setting method, that is, the theoretical vehicle speed based on the rotation of the internal gear and the actual vehicle speed due to the slip of the rear wheels 5R.
Even if there is a locally hard part in the same field, the dashing phenomenon and the normal running can be reliably distinguished. Since the brake pedals 26 of the tractor 10 are configured to be independently operable left and right to facilitate turning on the field, each time the operation is completed and the vehicle shifts to running on the road, the pedals 26 There is an annoyance that the lock 26 is locked so as to rotate integrally.

Here, when the tractor 10 detects a high-speed running state unsuitable for one-sided braking, the controller 9 activates the brake devices 6.6 for the left and right rear wheels 5R, 5R. For example, as a method for detecting a high-speed running state, when the vehicle speed from the vehicle speed sensor 4 is detected and only one of the brake pedals 26 is operated in a state where the vehicle speed is equal to or higher than a predetermined vehicle speed, this operation is performed by the controller 9. The left and right brake devices 6.6 are operated by expanding and contracting the pistons of the proportional pressure control valves 63L and 63R so as to synchronize with the one-side brake.

Further, as another embodiment for detecting a high-speed running state, a shift position detecting sensor is provided on the shift lever of the tractor 10, and when the shift lever is operated to a high-speed shift position that is considered to be used for road running, The brake output by the controller 9 may be performed in the same manner as described above. This eliminates the need for the operator to lock or unlock the brake pedal many times when the tractor 10 moves between fields, and the like, thereby making it possible to improve work safety.

[Brief description of the drawings]

FIG. 1 is a diagram showing a transmission mechanism of a tractor.

FIG. 2 is an overall side view of the tractor.

FIG. 3 is a hydraulic circuit diagram of the tractor.

FIG. 4 is a control block diagram.

FIG. 5 is a flowchart.

FIG. 6 is a flowchart of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Rotating claw 3 Rotary work machine 4 Vehicle speed sensor 5 Wheel 6 Brake device 7 Main clutch 8 PTO shaft drive clutch 9 Controller

Claims (1)

[Claims] 1. A working machine 3 having rotating claws 2... At the rear of a vehicle body on which an engine 1 is mounted can be connected to the vehicle so as to be able to move up and down, and a vehicle speed sensor 4 for detecting an actual vehicle speed;
Brake devices 6.6 for braking R.5R are provided, and the rotational power of the engine 1 is branched into a traveling system L1 for driving the wheels 5R and 5R and a working machine system L2 for driving the rotating claws 2. A tractor provided with clutch mechanisms 7 and 8 for respectively independently turning on and off the rotational power, wherein the actual vehicle speed detected by the vehicle speed sensor 4 when the work machine 3 is lowered is set in advance. If the vehicle speed exceeds the vehicle speed, the rotational power of the work machine system L2 is cut off and the brake device 6.6 is turned off.
A dashing prevention control device for a tractor, comprising a control unit 9 for operating the tractor.