JPH11115404A - Tread adjusting device for power vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of overturning of a machine body at the time of tread adjustment in an inclined place by forming a device so that the tread adjustment is prohibited when an angle of inclination sensor detects the predetermined angle of inclination. SOLUTION: A double acting hydraulic cylinder 35 can extend and shrink the tread of rear wheels 3. The right and the left rear wheels 3 can be independently moved in right and left, and both the right and the left rear wheels can be extended at the same time or one of them can be extended with a delay from the extension of the other by appropriately switching each pair of switching valves 40, 40, 41, 41. A control circuit is formed so that the switching valve 41 of the tread adjustment is returned to the neutral position when an angle of inclination sensor detects that a machine body comes close to the angle, at which danger of generation of overturning exists. Namely, when the machine body comes close to the angle, in which danger of generation of overturning of the machine body exists, the angle of inclination sensor cancels the exciting of solenoids 53, 54 of the switching valve 41 so as to reset the switching valve 41 at the neutral position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called tread adjusting device for adjusting a wheel distance of a powered vehicle such as a tractor, a rice transplanter, or a riding management device, and to which tread adjustment can be performed safely.

[0002]

2. Description of the Related Art
2. Description of the Related Art In a powered vehicle such as a tractor, there is known a vehicle in which treads of left and right front wheels or rear wheels are expanded and contracted by hydraulic pressure. The tread is adjusted according to the ridge width of the field. However, the field is not always flat but inclined at some places.
If the tread adjustment is performed in such an inclined place, the right-left balance of the aircraft may be lost, and the aircraft may roll over.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to enable tread adjustment to be performed safely.
The following technical measures were taken. That is, in a powered vehicle capable of adjusting the tread, a tilt angle sensor 16 for detecting a right and left tilt angle of the body is provided, and when the tilt angle sensor 16 detects a predetermined tilt angle, the control means 20 for inhibiting the tread adjustment is provided. A tread adjusting device for a powered vehicle is provided.

[0004]

When the inclination angle sensor detects that the aircraft has approached a dangerous tipping angle at which the aircraft is likely to roll over due to the lateral inclination, a control command for inhibiting tread adjustment is issued.
The tread can not be adjusted after being taken out of the rack 20.

[0005]

Embodiments of the present invention will be described below with reference to the embodiments shown in the drawings. Reference numeral 1 denotes a tractor as a power vehicle, which is provided with front wheels 2 and 2 and rear wheels 3 and 3 at the front and rear portions of the fuselage, and transmits rotation power of an engine 4 to a transmission case.
The transmission in the gear 5 is appropriately decelerated, and the decelerated rotational power is transmitted to the front wheels 2, 2 and the rear wheels 3, 3. A hydraulic cylinder case 8 is attached to the rear upper part of the transmission case 5, and lift arms 9, 9 are pivotally mounted on both left and right sides of the hydraulic cylinder case 8.
When hydraulic oil is supplied to or discharged from a single-acting hydraulic cylinder (not shown) housed in a hydraulic cylinder case 8, the lift arms 9, 9 rotate vertically.

The lift arms 9, 9 and the lower link 11,
Lift rods 12 and 12 are interposed and connected between the lift rod 11 and the lift rod 12. The right lift rod 12 is composed of a hydraulic telescopic cylinder 12a. 13 is a top link. A top link 13 and the lower link 11,
11 constitutes a conventionally known three-point link mechanism.
A rotary tillage device 15 as one working machine is detachably connected to the three-point link mechanism.

Reference numeral 16 denotes an inclination angle sensor which is a means for detecting the amount of inclination of the body, and detects an inclination angle of the tractor 1 in the left-right direction. Rolling control of the rotary tillage device 15 is performed by a tilt angle sensor 16, a stroke sensor 17 provided side by side with the hydraulic lift rod 12, and a tilt angle setting device 18 provided beside the cockpit. You. That is, the tilt angle sensor value and the stroke sensor value are set in a later-described control so that the tilt posture set by the tilt angle setting device 18 is obtained.
The hydraulic lift rod 12a is read into the rack 20 and is compared with the inclination set value so that the hydraulic lift rod 12a expands and contracts to a predetermined length.

Next, the rear wheel tread adjustment mechanism will be described with reference to FIG. Reference numeral 21 denotes a differential device for the rear wheel 3, and rotational power reduced by a transmission in the transmission case 5 is transmitted to the rear wheel differential device 21 via a drive pinion 24. Braking devices 25, 25 are provided on both left and right sides of the rear wheel differential device 21, and planetary reduction gear mechanisms 26, 26 are provided outside thereof. A solid inner rear axle 29, 29 is fixed to the carriers 28, 28 constituting a part of the planetary reduction gear mechanisms 26, 26, and a hollow outer rear axle 30 is slidably mounted on the outer rear axle 30 from the outside. Mated. A flange 3 is provided at the outer end of the outer rear axle 30.
The rear wheel 3 is provided with a bolt 3
One is tightened. The rear axles 29 and 30 are integrated by spline fitting, and rotational power is transmitted through the splines.

Reference numeral 33 denotes a rear axle housing which supports the rear axles 29, 30. The rear axle housing 33 integrally incorporates a hydraulic cylinder 35, which is an actuator for moving the rear wheel 3 in the right and left direction. I have. A plate-like member 36 integral with the flange 32
The outer end of the piston rod 37 is fixed to the hydraulic cylinder 35, and hydraulic oil is fed into the hydraulic cylinder 35 to expand and contract the piston rod 37 to adjust the rear wheel 3 tread via the plate member 36. I have.

In FIG. 2, reference numerals 40 and 41 are switching valves. The switching valve 40 is used to select whether the hydraulic oil sent from the hydraulic pump 42 is used for extracting the external oil pressure or used for adjusting the tread. If the switching valve 40 is switched to the external oil pressure extracting side, , Other working machines such as a front loader can be hydraulically driven. Conversely, if the working machine is switched to the tread adjustment side, the wheel span of the rear wheel 3, that is,
The tread can be adjusted arbitrarily.

As is apparent from FIG. 2, the hydraulic cylinder-3
Reference numeral 5 denotes a return type, which can extend or shorten the tread of the rear wheel 3. The left and right rear wheels 3 and 3 can be independently moved to the left and right. By appropriately switching the pair of switching valves 40, 40, 41 and 41, the left and right are almost simultaneously or one is the other. It can be expanded and contracted more slowly.

In the present invention, the control circuit is configured to return the tread adjustment switching valve 41 to neutral when the inclination angle sensor 16 detects that the aircraft approaches the danger angle of overturning. That is, when the inclination angle sensor 16 approaches a dangerous angle at which the aircraft is likely to fall, the switching valve 41 is turned off.
The solenoids 53 and 54 are de-energized and the switching valve 41
Is returned to the neutral position.

Next, the structure of the control system will be briefly described with reference to the control block diagram of FIG. 3. The input side of the controller 20 as a control unit having a microcomputer is provided with an inclination angle sensor 16 and a flash unit. Sensor 17, tilt angle setting device 18
Is connected. Furthermore, a hydraulic cylinder for adjusting the tread
Sensors 49 and 50 for detecting the length of expansion and contraction of 35 and a setter 55 for setting the length of the tread are connected to the controller 20.

On the other hand, the output side of the
Extension and contraction solenoids 46, 47 for extending and contracting the hydraulic lift rod 12a for ring control, and solenoids 52, 52, 53, 53, 5 for switching oil paths.
4 and 54 are connected. When the solenoids 52, 52 are excited, the hydraulic oil sent from the hydraulic pump 42 flows to the sub-computer side (ports A, B), and is switched to the tread adjustment side when the excitation is released.

When the solenoids 53, 53 are excited in this state, the hydraulic cylinders 35, 35 are extended and the tread is expanded, and when the solenoids 54, 54 on the opposite side are excited, the hydraulic cylinders 35, 35 are activated. Shorter and narrower tread. The amount of expansion and contraction of the left and right hydraulic cylinders 35 and 35 is detected by sensors 49 and 50, and when the hydraulic cylinders 35 and 35 reach the length set by the tread setting device 55, the switching valves 41 and 41 are set to the neutral position. Return to.

During the tread adjustment, the body tilts in the left-right direction, and when the inclination approaches the dangerous overturning angle, the tread adjustment switching valves 41 return to the neutral state. Therefore, tread adjustment cannot be performed in a state where the body is largely inclined. FIG. 4 shows an obstacle sensor-5 beside the tractor-1.
7 shows an example in which the tread adjustment is prohibited when the obstacle sensor 57 detects a worker or another dangerous substance.

In this embodiment, the switching valve 40 is appropriately switched to perform the tread adjustment when the external hydraulic mechanism is not used. However, the working oil for changing the rolling posture of the working machine is used. Tread adjustment may be performed. In this case, the tread may be adjusted by using a manual circuit of a hydraulic circuit for rolling control. For example, the rolling control circuit is switched from an automatic mode to a manual mode, and is shown in FIG. By operating the extension-side or shortening-side operation switch (not shown) for the outer rolling control,
Hydraulic oil flowing through the hydraulic lift rod 12a for rolling control may be guided to the hydraulic cylinder 35 for tread adjustment.

FIG. 5 shows a configuration in which the extension length of the tread is detected by a push-pull wire 58 and a rotary potentiometer 59. Connect one end of the wire to the plate member 3
6 and the other end of the wire is connected to a potentiometer 59.
To detect the length of the tread. Compared to a linear stroke sensor, the rotary potentiometer is less expensive and allows the tread adjusting device to be constructed at a lower cost.

FIG. 6 shows a fender 61 provided with a switch 62 so that the tread can be easily adjusted from outside the cabin. Switch 62a on the extension or contraction side,
By pressing the button 62b, the expansion and contraction of the tread can be adjusted. If the operation switches 62a and 62b are provided on the fender portion as in this example, the adjustment of the tread is simplified. Although the operation switch 62 is installed in the middle of the fender in the illustrated example, it may be installed at the rear end.

Next, the construction of an improved portion of a tractor without a cabin will be described. The tractor 1 described in the above embodiment has an independent PTO clutch. The independent PTO clutch allows the power to be turned on and off independently of the traveling clutch.
In this improved device, a power on / off switch 64 is provided on the upper surface of the fender 61 so as to protrude upward.

When the switch 64 is operated downward, a PTO clutch (not shown) is engaged, and when the switch 64 is operated upward, the PTO clutch is disengaged. A switch 65 for raising and lowering the work machine is provided outside the switch 64,
When the switch 65 is raised upward, the work implement rises, and when the switch 65 is lowered, the work implement falls. As is clear from the figure, both switches 64 and 65 are provided close to each other, and are configured so that both switches 64 and 65 can be operated simultaneously or separately with one hand.

Since the switches 64 and 65 are both commercially available toggle switches, the switches 64 and 65 have a simple configuration and improved operability. When both switches 64 and 65 are tilted downward, the work implement is lowered and the PTO clutch is engaged. Conversely, when both switches 64 and 65 are tilted upward, the PTO clutch is disengaged and the working machine rises.

Next, the configuration around the front wheel in FIG. 8 will be described. In the figure, reference numeral 70 is a front wheel differential device, 71 is a front wheel drive shaft,
72 is a bevel gear spline-fitted to the outer end of the front wheel drive shaft 71; 73 is a kingpin;
The lower bevel gear 75 is configured to always mesh with a large-diameter bevel gear 78 integrated with the wheel shaft of the front wheel 2.

A turning case 80 accommodating the large-diameter bevel gear 78 turns around the kingpin with respect to a fixed case 83 attached to the outer end of the front axle case 81. The upper part of the fixing case 83 is opened, and the opening is closed by a lid 85 with an O-ring. A knuckle arm 86 is fixed to the upper part of the lid 85 by a bolt 87, and the knuckle arm 86 is fixed. The outer end is fixed to the upper surface of the rotating case 80.

The lower part of the rotating case 80 which rotates around the king pin 73 is fitted into the fixed case 83, and the rotating case 8
The upper part of the wheel 0 is sandwiched and supported by the fixed case 83 from above and below via the knuckle arm 86 and the lid 85, so that the final reduction gear case is damaged even if the shared load on the front wheel 2 increases. It is possible to sufficiently support the front wheel 2 without fear of occurrence. 9 and 10 for reference.
The cross-sectional structure of the front wheel final case is shown in FIG.

FIG. 9 shows a lower case of the turning case 80 fitted to a fixed case 83 and supported for steering and turning.
Such a configuration has a disadvantage that the strength is insufficient when a heavy load is applied to the front wheel 2. Further, the structure shown in FIG. 10 is characterized in that the rotating case 80 is sandwiched from above and below with respect to the fixed case 83 and is supported, so that the structure is complicated. There is a disadvantage that the cost is increased accordingly. That is, in the case of the structure shown in FIG. 10, the processing of the lid constituting the fulcrum of the knuckle arm 86 and the method of attaching it to the fixing case 83 become complicated, and the manufacturing cost is increased. However, according to the improved device, the knuckle arm 86 is fastened and fixed to the lid 85 made of a plate-like member having an O-ring on the outer periphery by the bolt 87, so that the manufacturing cost does not increase.

[0027]

As described above, the present invention relates to a power vehicle capable of adjusting a tread, which is provided with an inclination sensor for detecting a left-right inclination angle of a body, and when the inclination sensor detects a predetermined inclination angle, the tread is controlled. Since the control means is provided to prohibit the adjustment, the center of gravity moves greatly when adjusting the tread on a slope or the like, and the aircraft does not roll over the dangerous overturning angle. It can be done.

[Brief description of the drawings]

FIG. 1 is an overall side view of a tractor.

FIG. 2 is a diagram showing a cross section of a rear axle housing and a hydraulic circuit.

FIG. 3 is a control block diagram.

FIG. 4 shows a tractor with an obstacle sensor attached.
It is a perspective view of.

FIG. 5 is a cross-sectional view of a rear axle housing to which a push-pull wire type sensor is attached.

FIG. 6 is a perspective view of a main part.

FIG. 7 is a plan view of an independent PTO clutch operation unit.

FIG. 8 is a sectional view of a front wheel final case portion.

FIG. 9 is a sectional view of a front wheel final case portion of the conventional device.

FIG. 10 is a cross-sectional view of a front wheel final case portion of the conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tractor 2 Front wheel 3 Rear wheel 4 Engine 5 Transmission case 7 Handle post 8 Hydraulic cylinder case 10 Hydraulic cylinder 15 Rotary tillage device 16 Inclination angle sensor 17 Stroke sensor 18 Inclination angle setting device 20 Control −La 21 Rear wheel differential device 33 Rear axle housing

Claims (1)

[Claims] 1. A powered vehicle with adjustable tread,
A tread adjusting device for a powered vehicle, comprising: a tilt angle sensor for detecting a right and left tilt angle of the body, and a control means for prohibiting the tread adjustment when the tilt angle sensor detects a predetermined tilt angle. .