JPH10329560A - Pto device for agricultural work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a need for switching of a rotation direction many times and to relieve operation by an operator by a method wherein when a detecting state coincides with a state having a preset condition, control is effected such that a forward reverse switching device is switched to the reverse side. SOLUTION: The turning effort of an engine 1 is branched into a running drive system L1 and PTO system L2. After PTO system L2 is branched by a forward reverse switch device 15, rotation of a PTO shaft 25 is transmitted to a forward reverse switching device 2 to switch rotation a PTO shaft 25 into forward or reverse. When a PTO mode is 'AUTO', it is decided whether the height of a working machine exceeds a specified value, whether a reverse travelling detecting switch 5 is turned ON, and whether operation to raise a rear cover is detected by a rear cover angle sensor 6. When all are YES and until raising operation for a working machine is detected again, the forward reverse switching device 2 is switched to the reverse side once. By constituting a device such that when this condition is set at an ROM and operation is detected, the PTO shaft 25 is reversed, switch operation by an operator himself is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction of an agricultural work vehicle having a PTO device.

[0002]

2. Description of the Related Art Conventionally, as in a tractor disclosed in Japanese Patent Application Laid-Open No. 1-168523, the rotational power of an engine is branched into a traveling wheel drive system and a PTO system, and the rotational direction of the PTO system is changed to the traveling drive system. Some have a forward / reverse switching device that switches between forward and reverse independently of the above. These tractors are connected to a rotary work machine to enable up-cut tilling and down-cut tilling during tilling work.

[0003]

However, in a tractor to which such a rotary working machine is connected, the PTO
When the device is switched to reverse rotation, etc., the whole field is used for up-cut tilling, and when the soil biased to the edge of the field is simply brought to the middle, it is temporarily switched and used There is. In this case, the operation of the tractor is performed, for example, by performing down-cut tilling, raising the work machine at the headland, turning, and then switching the rotation direction of the PTO device to the reverse rotation, moving backward to the ridge, and rotating the work machine. On the ground and move forward a certain distance. For this reason, the operator has to switch the rotation direction of the PTO device many times every time the soil is approached, which is a troublesome operation.

[0004]

The present invention employs the following technical means in order to solve the above problems. That is, a forward / reverse switching device 2 that branches the rotational power of the engine 1 into a traveling wheel drive system L1 and a PTO system L2 and switches the rotational direction of the PTO system L2 forward / reverse independently of the traveling drive system L1. In the agricultural work vehicle having the same, a plurality of different operation units 21 and 28 of the vehicle or an operation unit 49 operated by the operation unit detects the movements of the operation units 5 and 6.
When each of these detection states matches a state set in advance, a PTO device for an agricultural work vehicle having control means 33 for switching the forward / reverse switching device 2 to the reverse rotation side is provided. Further, the plurality of operation units include an operation unit 21 for switching the forward / backward movement of the vehicle body, an operation unit 28 for changing the posture of the rear cover 49, or a sensor 6 for detecting the posture of the rear cover 49.

[0005]

As described above, in the work requiring the reverse rotation of the PTO device, attention is paid to the fact that there are fixed operation conditions, and these operation conditions are set in advance, and the forward rotation of the PTO device, This switching operation can be eliminated in the work that is required by repeating the reverse rotation, and the operation of the operator can be reduced.

In the above-mentioned tilling work, a forward / backward switching operation of the vehicle body and an operation of changing the attitude of the rear cover 49 are often performed, and at least both of these operations are detected or the movement of the rear cover 49 is detected. An accurate operation of the control means is possible without an operator's switching operation.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The objects and solutions of the present invention are as described above. Hereinafter, an agricultural tractor (hereinafter, tractor 10) will be described as an example of an agricultural work vehicle. The tractor 10 is configured as a main part of a vehicle body by integrally connecting the clutch housing, a front transmission case 14F, a rear transmission case 14R, and the like from the engine 1 in the hood 11 to a pair of left and right front wheels at the front of the vehicle body. 12 and 12 are provided, and a pair of right and left rear wheels 13 and 13 are provided at a rear portion.

A handle post 19 is provided behind the hood 11, and a steering handle 20 is provided above the handle post 19, and the front wheels 12, 12 are steered by rotating the steering handle 20. I have. Also, on the side of the handle post 19,
A forward / reverse switching lever 21, which is an operation unit for switching the forward / backward switching device 15 for traveling, is provided to protrude. And
A reverse detection switch 5 that is turned on when the lever 21 is operated to the reverse position is provided at the base of the lever 21.

A floor 22 is provided above a central portion of the vehicle body, and a cockpit 23 is provided above a rear portion of the floor 22. Fenders 24 are provided on both left and right sides of the cockpit 23 so as to cover the rear wheel 13 from the front to the upper side. Between the cockpit 23 and the fenders 24, the rotation of the traveling speed change lever 8 and the rotation of a PTO shaft 25 described later are described as " PTO mode changeover switch 26 for selecting forward rotation, reverse rotation, auto, and off, a rear cover pressure setting device 28 as an operation unit for changing the posture of the rear cover 27, and a lifting position of the work implement 29 Is provided. And
Potentiometers 9 and 31 are provided at the rotation bases of the shift lever 8 and the position lever 30, respectively, and the operation angles of the levers 8 and 30 are detected and transmitted to the controller 33 as control means. ing.

The rear part of the tractor 10 will be described.
A PTO shaft 25 protrudes from the rear surface of the transmission case 14R, and a cylinder case 3 having a built-in hydraulic cylinder 35 for lifting and lowering the work implement is provided on the rear upper surface of the case 14R.
6 is provided, and by the expansion and contraction of the piston of the hydraulic cylinder 35,
Lift arms 3 provided on left and right sides of cylinder case 36
2, 32 are vertically rotated. Hydraulic oil is supplied into the hydraulic cylinder 35 by opening the oil passages of the proportional control valve 37 for raising the working machine and the proportional control valve 38 for lowering, which are switched by the energization of the controller 33, Alternatively, it is configured to be discharged and expanded and contracted. Further, a lift arm angle sensor 39 for detecting the rotation angle is provided at the rotation base of the lift arms 32, 32. A top link 40 and left and right lower links 41, 41 are provided at the rear of the transmission case 14R.
And a rotary work machine 29 is connected thereto.

Next, the rotary working machine 29 will be described. The rotary working machine 29 transmits the rotational power of the PTO shaft 25 via a universal joint 45, and further transmits the rotational power to a tilling shaft 47 having a plurality of tilling claws 46.
And drive. A rotary cover 48 is provided above the tilling claws 46. A rear cover 49 is pivotably attached to the rear end of the rotary cover 48. A rear cover angle sensor 6 is provided above the rotary cover 48 to detect the rotation angle of the rear cover 49 via a link mechanism. Further, a pressure rod 50 is provided on the rear cover 49, and an electric cylinder 52 as a posture changing means of the rear cover 49 is provided above the pressure rod 50 via a rear frame 51. Thus, the piston of the electric cylinder 52 expands and contracts by setting the rear cover pressure setting device 28, and the rear cover 49
The pressure on the ground is adjusted. When the pressure of the setting device 28 is adjusted to the minimum, the piston of the electric cylinder 52 is shortened, the rear cover 49 is lifted upward, and the tilling part 42 is opened.

Next, the structure of the transmission mechanism of the tractor 10 will be described with reference to FIG. The rotational power extracted from the engine 1 is transmitted from the main clutch 55 to the forward / reverse switching device 15.
The driving drive system L1 transmitted to the main transmission 16 and the auxiliary transmission 17 and the PTO shaft 2
5 is branched to a PTO system L2 that drives the PTO 5.

The rotational power of the traveling wheel drive system L1 is transmitted from the forward / reverse switching device 15 to the main transmission device 16 and the auxiliary transmission device 17
The transmission of the rotational power, which has been appropriately decelerated and finally decelerated, to the rear wheels 13, 13 via the rear wheel differential mechanism 65, and the rotational power decelerated by the auxiliary transmission device 15, the front wheel drive transmission device 18, the front wheel The transmission is also transmitted to the front wheels 12, 12 via the differential mechanism 66.

The PTO system L2 includes the forward / reverse switching device 15
After the branch, the rotation is transmitted to the forward / reverse switching device 2 that switches the rotation of the PTO shaft 25 between forward and reverse. The forward / reverse switching device 2 has a configuration of a synchromesh type gear mechanism. The clutch hub 56 is connected to a piston of a hydraulic cylinder 58 via a shifter 57, and the rotational power input by the expansion and contraction of the piston is switched between forward and reverse. The transmission is performed to the PTO transmission shaft 59. That is, when the piston of the hydraulic cylinder 58 is extended, the input rotational power is converted to PT
When the O transmission shaft 59 is driven, the tilling shaft 47 is driven in the up-cut direction (the rotation direction of the wheels and the rotation direction of the rotary is the same), and the piston of the hydraulic cylinder 58 is shortened, the input rotational power is transmitted to the idle gear 60. , The PTO transmission shaft 59 is driven in reverse rotation, and the tilling shaft 47 is driven in the downcut direction (the rotation direction of the wheels and the rotation direction of the rotary are reversed).

The piston of the hydraulic cylinder 58 is
Switching control valve 6 switched by energization of controller 33
It is configured to operate from the opening of the first oil passage. Further, a gear-type PTO transmission 62 is provided on the lower transmission side of the PTO transmission shaft 59, and the number of rotations is adjusted to four stages to adjust the PTO transmission.
The transmission is to the TO shaft 25. The controller 33 includes a CPU 67 as a central processing unit and a ROM 6 as a storage device storing a control program of the present invention.
8 and a RAM 69 for temporarily storing sensor values and the like.
, A rear cover pressure setting device 28, a reverse detection switch 5,
Potentiometer 9 of shift lever 8, potentiometer 31 of position lever 30, lift arm angle sensor 3
9, the rear cover angle sensor 6 and the like are connected and provided.
The output unit includes a solenoid 6 of a switching control valve 61 that operates a hydraulic cylinder 35 that switches the PTO shaft 25 between normal and reverse.
1a, 61b, the motor 52a of the electric cylinder 52, and the solenoids 37a, 38a of the proportional pressure control valves 37, 38 for operating the hydraulic cylinder 35 for lifting and lowering the work implement are connected and provided.

The PT of the tractor 10 constructed as described above
The operation of the O device will be described based on the control flowchart shown in FIG. At first, the electric system of the tractor is turned “on”, and at the same time, the controller 33 reads the states of various switches and sensors and stores them in the RAM 69. Then, the on / off state of the PTO mode changeover switch 26 is determined, and when this is “on”, the process proceeds to STEP 3 to determine this mode. Here, if the mode is switched to the “reverse rotation” mode, the solenoid 6 of the switching control valve 61
1b, the piston of the hydraulic cylinder 58 is shortened to rotate the PTO shaft 25 in the reverse direction, that is, in the up-cut direction (STEP 10). Also, in the determination of STEP3,
When the PTO mode changeover switch 26 is switched to the "forward rotation" mode, the process proceeds to STEP11, in which the piston of the hydraulic cylinder 58 is extended to rotate the PTO shaft 25 in the reverse direction, that is, in the downcut direction, and in STEP3.
When the mode is switched to the "auto" mode, the potentiometer 3 of the position lever 30
1 or whether the work implement 29 is at a certain height or higher from the lift arm angle sensor 39, whether the reverse detection switch 5 is on, and the rear cover pressure setting device 2
8 or rear cover angle sensor 6 to rear cover 49
It is determined whether or not the tilling unit 42 has been raised to the extent that the tilling unit 42 is opened (STEPs 4 to 6). If all of these determinations are YES, until the lifting operation of the work implement 29 is detected again (STEP
8) The forward / reverse switching device 2 of the PTO device is temporarily switched to the reverse rotation side. If at least one of the determinations in STEPs 4 to 6 is NO, the process proceeds to STEP 11, and the PTO shaft 25 is rotated in the normal rotation direction.

The PT of the tractor 10 constructed as described above
The O device focuses on a pattern including an operation of raising the work implement 29, a rearward operation of the vehicle body, and an operation of raising the rear cover 49 when the soil shifted toward the edge of the field is moved to the center of the field. The condition is set in the ROM 68, and when this operation is detected, the PTO shaft 25 is rotated in the reverse direction. Therefore, even when there are scattered points in the field that need to be filled with soil, and the PTO shaft 25 needs to be frequently rotated in the reverse direction during the down-cutting operation, that is, the tilling shaft 47 needs to be reversely rotated, the switching operation by the operator himself is required. Can be eliminated.

Incidentally, STEP 8 in the above-mentioned flowchart is shown.
As a condition for canceling the reverse rotation of the PTO shaft 25 in the "auto" mode, the lifting operation of the work implement 29 is detected. However, a switch for canceling the operation is provided instead. Alternatively, it may be configured to detect that the angle of the rear cover 49 has returned to the state at the time of the down-cut tilling and release the angle. In the above description, the electric cylinder 52 has been described as a means for changing the attitude of the rear cover 49. However, the electric cylinder and the hydraulic cylinder may be used as a means for changing the attitude of the rear cover 49 so that the rear cover 49 can be expanded and contracted or slidably stored to open the tilling unit 46. Is also good.

The condition for switching the forward / reverse switching device 2 of the PTO device to the reverse rotation side may be changed according to the shape of the field or the operation pattern of the operator. For example,
A sensor for detecting the operation angle of the steering handle 20 may be provided, and after the steering operation is detected, that is, when the reverse operation is performed within a predetermined time after the turning is detected, the PTO device may be switched to the reverse rotation side. When the vehicle speed is set to a high-speed position where the vehicle travels on the road, etc., based on the detection of the potentiometer 9 of the shift lever 8,
It is also possible to adopt a configuration in which the switching of the TO device to the reverse rotation side is suppressed to prevent the tilling claw 47 from being damaged.

[Brief description of the drawings]

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

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

FIG. 3 is a block diagram showing a connection state of a controller.

FIG. 4 is a control flowchart.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 engine 2 forward / reverse switching device 5 reverse detection switch 6 rear cover angle sensor 21 forward / backward switching lever 25 PTO shaft 28 rear cover pressure setting device 30 position lever 33 controller 58 hydraulic cylinder (for PTO forward / reverse switching) L1 traveling wheel drive system L2 PTO system

Claims (2)

[Claims] 1. A traveling wheel drive system (L) for transmitting rotational power of an engine (1).
1 and a PTO system L2, the agricultural work vehicle having a forward / reverse switching device 2 for switching the rotation direction of the PTO system L2 between forward and reverse independently of the traveling drive system L1. Detecting means 5 and 6 for detecting these movements are provided in the units 21 and 28 or the operating unit 49 operated by the operating unit. When each of these detection states matches a state set in advance, the forward / reverse switching device 2 is used. A PTO device for an agricultural work vehicle, comprising: a control unit 33 for switching the rotation direction to the reverse rotation side. 2. The operation unit according to claim 1, wherein the plurality of operation units include an operation unit for switching forward / backward movement of the vehicle body, an operation unit for changing a posture of a rear cover, and a sensor for detecting a posture of the rear cover. The PTO device of the agricultural work vehicle described in the above.