JPH084349Y2 - Front wheel speed increasing device for tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to a tractor provided with a front wheel speed increasing device.

(B) Conventional technology Conventionally, a front wheel cutting angle sensor, a front wheel speed increasing mechanism, a hydraulic circuit for switching the front wheel speed increasing mechanism, and an electromagnetic circuit inserted in the hydraulic circuit and operated by a detection result of the front wheel cutting angle sensor. Tractors with valves are already known.

(C) Problems to be solved by the invention In the known tractor, the front wheel is always accelerated when the turning angle sensor inserted in the steering transmission system of the front wheel detects a turning angle more than a predetermined value. Therefore, when an unfamiliar driver drives the tractor and turns the aircraft on the headland, if the aircraft turns to some extent, the steering wheel must be turned back quickly to turn off the front wheel turning angle sensor. However, the machine body may pass the next work position, and in such a case, the machine body must be aligned while moving the machine body back and forth, resulting in a decrease in work efficiency.

(D) Means for Solving Problems The present invention is directed to a front wheel turning angle sensor, a front wheel speed increasing mechanism,
In a tractor equipped with a hydraulic circuit for switching the front wheel speed increasing mechanism and an electromagnetic valve inserted in the hydraulic circuit and operated according to the detection result of the front wheel breaking angle sensor, the front wheel breaking angle sensor and the electromagnetic valve are connected. The control circuit is equipped with a selection switch that switches between a cutting position, an automatic position, and an artificial operation position, and a quick turn switch that is manually operated is provided in the driving section, and this quick turn switch is manually operated by the selection switch. The position is inserted in the circuit connected to the electromagnetic valve, and the detection result of the front wheel turning angle sensor is not transmitted to the electromagnetic valve by the selection switch, the state is automatically transmitted, and the quick turn switch is used. It is possible to automatically rotate the aircraft quickly based on the detection result of the corner angle sensor. Also it is, also pivoting the aircraft in a state of not operating the front-wheel speed increasing mechanism, in the manner it is also possible to artificially intermittently detection results of the front wheel turning angle sensor to solve the problems described above.

(E) Action When the tractor is traveling on the road or moving in the field, setting the selection switch to the OFF position will not accelerate the front wheels even if the front wheel turning angle becomes large, When running a tractor with a working machine mounted on the rear in the field, if a skilled driver sets the selection switch to the automatic position, when turning the machine on the headland,
If the front wheel is automatically accelerated within the range where the front wheel's turning angle exceeds a predetermined value and an unfamiliar driver sets the selection switch on the circuit side of the quick turn switch, the driver must turn on the quick turn switch. , It is possible to carry out aircraft turning control with the front wheels not being accelerated, and with the quick turn switch turned on, the aircraft can carry out the same aircraft as when selecting the automatic position, but during aircraft traveling In addition, when the turning of the steering wheel is delayed, the quick turn switch is turned off to immediately release the front wheel acceleration, thereby preventing the aircraft from excessively turning.

(F) Embodiment One embodiment of the present invention will be described with reference to the drawings. A tractor 1 has front wheels 2,2 and rear wheels 3,3, and a rear wheel 3,3 is an engine 4.
Driven by a clutch housing and a transmission composed of a large number of transmission gears in the transmission case 5, a rear wheel differential mechanism, etc., and the front wheels 2, 2 are connected to the transmission, the front wheel speed increasing mechanism 6 and the front axle case 7. A hydraulic cylinder 8 driven via a front wheel differential mechanism or the like installed in the center of the, and erected in parallel with the front axle case 7 and also serving as a tie rod of both rod type has its end connected to a knuckle arm, Front wheel cutting angle sensor mounted on the front axle case 7 in parallel with the hydraulic cylinder 8
10, a switch 12 is attached to a guide tube 11, a rod 13 slidably fitted therein is provided with a circumferential groove into which a protrusion of the switch 12 is fitted, and a disk 15 is provided at both ends of the rod 13. When one of the working disks 16 fixed to the rod of the hydraulic cylinder 8 is screwed to move more than a predetermined amount, the disk 15 is pushed, the switch 12 is turned on, and the rod of the hydraulic cylinder 8 is returned to operate. In the process in which the operating disk 16 is separated from the disk 15, the rod 13 returns to the center by the pair of left and right return springs installed in the guide cylinder 11, and the switch 12 is turned off.

As shown in FIG. 3, the front wheel transmission mechanism 6 includes a diff mechanism 18 having a ring gear 17 driven through an intermediate gear by a gear that rotates integrally with a pinion shaft of a rear wheel diff of the transmission, and extends rearward. A hydraulic disc brake 20 mounted on the differential shaft 19 and a switching mechanism 21 for switching the differential case 18a of the differential mechanism 18 together with the differential shaft 19 or for freely rotating them relative to each other. The switching mechanism 21, when the sleeve 22 is moved to the position shown by the solid line,
The balls 23 ... Are pushed into the holes 24 formed in the outer periphery of the differential shaft 19 and are pushed into the differential case 18a of the differential mechanism 18 and the rear differential shaft 1
Since 9 and 9 rotate integrally, the front differential shaft 25 that is transmitted to the front wheels 2 is driven at a rotational speed that is synchronized with the rear wheels to become a so-called four-wheel drive state. It becomes a two-wheeled state that is not transmitted.

Further, as shown in FIG. 4, the switching drive device for actuating the shifter 26 fitted in the circumferential groove of the sleeve 22 includes the arm 27 fitted in the notch 26a at the base of the shifter 26 and the mission case 5. A cylindrical shaft 28 rotatably fitted through an O-ring, an operating shaft 30 rotatably fitted to the cylindrical shaft 28 and having the arm 27 fixed to its inner end, and an operating shaft 30 of the operating shaft 30. The winding spring 32 is fixed to the outer end and is linked to the outer end of the cylinder shaft 28 by a pawl clutch 31 so as to be rotatable by a small angle.
And a block 33 which is integrally rotated by urging in a fixed direction by means of a block 33. The claw clutch 31 is covered by a cylinder 35, and an arm 36 fixed to a cylinder shaft 28 is a rod.
It is linked to a switching lever 38 provided on the side of the driving section by 37, and at the base of the switching lever 38, it is turned off when it is set to the upper two-wheel drive position, and it is set to the lower four-wheel drive position. Then, a 4WD switch 39 that turns on is attached.

Further, an oil passage 41 communicating with the rear surface of the piston 40 for operating the hydraulic disc brake 20 supports a pipe through a cylinder portion 43 which supports the shifter 26 and is a support portion of a shifter shaft 42 which also serves as a spool. 44, which is connected via an electromagnetic valve 45 to a pipe leading to a hydraulic pump.

The operation step 47 is provided with a quick turn switch 48 and a foot pedal 49 for connecting and disconnecting the quick turn switch 48, and the operation panel 46 is capable of switching between an OFF position a, an automatic position b, and a manual operation position c. There is a selector switch 51 that can turn on the high speed position H of the lever guide groove 52 of the traveling device only when the auxiliary shift lever is set to the high speed position H.
A front wheel speed-up switch 53 that is turned off is provided, and the control circuit of the electromagnetic valve 45 has a key switch 55, a four-wheel drive switch 39, a switch 12 of the front wheel breaking angle sensor 10 and a selection switch 51 as shown in FIG. Is inserted in series, and the quick turn switch 48 is inserted in the circuit d in which the manual operation position c of the selection switch 51 and the electromagnetic valve 45 are connected.

In the above-described device, when the switching lever 38 is set to the upper two-wheel drive position, the four-wheel drive switch 39 is turned off and the cylinder shaft 28 is turned off.
Is rotated via the rod 37 and the arm 36, the shifter 26 slides the sleeve 22 to the position shown by the dotted line in FIG. 2, whereby the differential case 18a and the rear differential shaft 19 are rotatable relative to each other. It becomes a two-wheel drive state.

Further, when the switching lever 38 is set to the lower 4WD position, the 4WD switch 39 is turned ON, and the sleeve 22 moves the cylinder shaft 28,
It slides to the position shown by the solid line in FIG. 2 via the arm 27 and the shifter 26, and pushes the ball 23 into the hole 24 near the rear part to differentially lock, and the differential case 18a and the differential shaft 19 at the rear integrally rotate. Since the vehicle is in the four-wheel drive state, the front wheels 2 are forcibly driven.

When the tractor 1 is run in this four-wheel drive state and work is performed, if the driver is an expert, the selection switch 51 is set to the automatic position b, and the steering handle 50 is rotated on the headland, When the hydraulic cylinder 8 operates to move the rod laterally and the cutting angle of the front wheel 2 reaches the set angle, the rod 13
Slides to turn on the switch 12, so that the solenoid of the electromagnetic valve 45 is energized to switch, and the hydraulic fluid pumped by the pump P flows into the cylinder portion 43 through the pipe 44, and the shifter shaft 42 is moved to the above-mentioned position. The shifter 26 moves the sleeve 22 to the position shown by the dotted line because it moves to the left side in the figure against the winding spring 32, and only prevents the ball 23 from coming out by the tapered surface of the inner peripheral surface of the rear end, and does not push it in. Therefore, the two-wheel drive state is established, and the cylinder portion 43 and the oil passage 41 communicate with each other, so that the hydraulic oil presses the piston 40, and the disc brake 20 operates and the differential shaft 19 is stopped. The mechanism 6 drives the front wheels 2 at double speed.

If the driver is inexperienced, set the selection switch 51 to the manual operation position and set the foot pedal to
If you do not step on 49, the quick turn switch 48
Since it is OFF, the electromagnetic valve 45 does not operate even if the front wheel turning angle sensor 10 is turned ON by turning the steering handle 50 largely in the 4WD state, and the front wheel 2 is rotationally driven at the normal speed. While turning.

Further, when the quick turn switch 48 is turned on to carry out the body traveling, the body rapidly turns.

However, when you release your foot from the pedal Petal 49 at the end of circulation,
Since the quick turn switch 48 is turned off, the electromagnetic valve 45 is switched to communicate with the drain, and the hydraulic oil pressing the piston 40 flows into the mission case 5 through the chamfered portion of the shifter shaft 42, and the shifter The shaft 42, the shifter 26, and the sleeve 22 move to the right by the returning action of the winding spring to return to the four-wheel drive state, and the vehicle body turns without increasing the speed of the front wheels 2.

(G) Effect of the Invention As described above, the present invention is directed to the front wheel cutting angle sensor 10, the front wheel speed increasing mechanism 6, the hydraulic circuit for switching the front wheel speed increasing mechanism 6, and the front wheel which is inserted in the hydraulic circuit. In a tractor having an electromagnetic valve 45 that operates according to the detection result of the turning angle sensor 10, a control circuit that connects the front wheel turning angle sensor 10 and the electromagnetic valve 45 to a cutting position, an automatic position, and an artificial operation position. A quick turn switch 48 for artificial operation is provided in the operating part through a selection switch 51 for switching, and the quick turn switch 48 is inserted in the circuit where the operation position of the selection switch 51 is connected to the electromagnetic valve 45. The detection result of the front wheel turning angle sensor 10 is not transmitted to the electromagnetic valve 45 by the selection switch 51, is automatically transmitted, and is transmitted via the quick turn switch 48. Since it is configured to select the transmission state, when the selection switch 51 is set to the off position when traveling on the road or when moving in the field, the front wheels are not accelerated when the aircraft is traveling, and it is safe. You can perform various driving.

In addition, a skilled driver can set the selection switch 51 to the automatic position, so that the front wheel can be speeded up automatically and rapidly turned by the detection result of the front wheel turning angle sensor 10, thus improving the work efficiency. can do.

Further, if the driver's driving skill is unskilled, if the selection switch 51 is set to the artificial operation position, even if the front wheel turning angle sensor 10 is in the detection state, the quick turn switch
By artificially turning OFF 48, the front wheel speed increasing mechanism is converted to the normal speed state, and it is possible to prevent the aircraft from excessively turning.

[Brief description of drawings]

1 shows an embodiment of the present invention. FIG. 1 is a control circuit diagram of an electromagnetic valve for switching a front wheel speed increasing mechanism, and FIG.
Figure is a perspective view of the operation panel, Figure 3 is a side view of the tractor,
FIG. 4 is a sectional view of the front wheel speed increasing mechanism, and FIG. 5 is a sectional view of the shifter drive portion. 2 ... front wheel, 6 ... front wheel speed-up mechanism, 10 ... front wheel breaking angle sensor, 18 ... differential mechanism, 19 ... differential shaft, 20 ... disc brake, 21 ... switching mechanism, 48 ... quick Turn switch, 51 …… Selection switch

Claims (1)

[Scope of utility model registration request] 1. A front wheel breaking angle sensor 10 and a front wheel speed increasing mechanism 6
And a hydraulic circuit for switching the front wheel speed increasing mechanism 6 and an electromagnetic valve 45 inserted in the hydraulic circuit and operated according to the detection result of the front wheel turning angle sensor 10, the front wheel turning angle sensor 10 In the control circuit that connects the solenoid valve 45 with the electromagnetic switch 45, a quick switch switch 48 for manipulating artificially in the operating section is provided by interposing a selection switch 51 for switching between a cut position, an automatic position, and an artificial operation position. The state where the turn switch 48 is inserted in the circuit where the artificial operation position of the selection switch 51 is connected to the electromagnetic valve 45, and the detection result of the front wheel turning angle sensor 10 is not transmitted to the electromagnetic valve 45 by the selection switch 51. And a state of automatically transmitting and a state of transmitting via the quick turn switch 48, the front wheels of the tractor. Speed control device.