JPH0930284A - Work vehicle diff lock device - Google Patents

Abstract

(57) An object of the present invention is to enable a diff lock device provided in a diff mechanism to be actuated to brake both drive shafts even when one brake pedal is depressed at the time of running on a slope or at high speed. SOLUTION: A braking device 49 is provided on each of left and right rear wheels 11.
And a pair of left and right brake pedals 6
(6 '), the brake pedal can be operated independently or integrally by operating the brake pedal, and a differential lock device 58 is provided between the drive shafts to provide a lateral tilt angle to the machine body. The tilt sensor S1 for detecting the speed change, the position detection switch S2 for detecting the high speed shift position of the auxiliary speed change lever 7, the switch SW for detecting the depression of each of the left and right brake pedals, and the manual switch SW1 for arbitrarily operating the diff lock device. A control valve V for activating the diff lock is provided, and a controller C for activating the diff lock device when the brake pedal is depressed when the vehicle is traveling at a set angle or more or at high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diff lock device provided in a diff mechanism for transmitting power to left and right axles.

[0002]

2. Description of the Related Art Conventionally, a diff mechanism is arranged in an axle drive unit of a rice transplanter, a tractor, etc., and both left and right wheels are driven through the diff mechanism. Further, a pair of left and right brakes for braking the respective axles are provided on both axles so that the side brakes can be operated by operating a pair of brake pedals provided on the step. For example, when one of the brake pedals is depressed to stop the axle on one side when the vehicle turns, the vehicle makes a sharp turn around the stopped rear wheel. Further, the pair of left and right brake pedals is configured to be connectable by a connector, and when the vehicle is traveling on the road, the brakes on both sides can be operated by depressing operation by connecting the connector. Depending on the frequency of use, the side brakes on both sides are not worn at the same level on the left and right sides, so the brake structure on one side may have a delayed effect. As a structure for preventing this, a diff lock mechanism that stops the diff mechanism and simultaneously brakes the axle has been used. For example, the actual development 62-16033
It is an automatic differential lock device such as.

[0003]

SUMMARY OF THE INVENTION In the automatic diff lock device described above, both brake pedals are connected by a connector,
Thereafter, the brake pedal is operated by depressing the brake pedal, and the structure is based on the premise that the left and right brake pedals are connected by a connector, which is complicated. Further, although the turning performance can be improved by disposing the diff device, wide use of the diff lock device has been required to improve the straight running performance.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a braking device on each of the left and right driving wheels, and connects both braking devices to a pair of left and right brake pedals to provide the brakes. In a traveling vehicle in which both braking devices can be independently or integrally braked by operating a pedal, and a diff lock device is provided between the two drive shafts, a means for detecting a left / right inclination angle of the vehicle body and a sub gear shift. A means for detecting a high speed shift position on the lever, a means for detecting depression of each of the left and right brake pedals, a means for arbitrarily actuating a diff lock device, and a diff lock driving means are provided, and when traveling at a set angle or more, or A control means for activating the diff lock device when the brake pedal is depressed during high-speed traveling is provided.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The problems to be solved by the present invention and the means for solving the problems are as described above. Next, the structure of the embodiments shown in the accompanying drawings will be described. FIG. 1 is an overall plan view of the tractor, FIG. 2 is a sectional view of a differential mechanism and a differential lock mechanism that drive both axles, FIG. 3 is a circuit diagram for operating the differential lock mechanism of the present invention, and FIG. FIG. 5 is a side view showing the lever, and FIG. 5 is a perspective view showing the left and right brake pedals provided with switches.

A tractor A of this embodiment will be described with reference to FIG. On the upper part of the frame F, a bonnet 1 for mounting the engine E is mounted on the front side, and a dashboard 2 is erected on a rear end portion of the frame F to project a steering wheel 3. The step portion 4 is formed on the upper surface of the frame F. Brake pedals 6 and 6 ′ are provided above the frame F at the right front portion thereof, and a clutch pedal 12 is provided at the left side thereof. A seat 5 is arranged behind the step portion 4,
An auxiliary gear shift lever 7 for switching between low speed traveling and high speed traveling, an elevating lever 8 for a working machine, and a plowing depth setting lever 9 are provided on the side thereof. The work implement B is mounted so as to be able to move up and down by protruding the left and right lower links 55 and the top link 56 at the center from the rear of the machine body.

The front wheels 10 are steered by the steering wheel 3. Power is transmitted to the mission case M from the output shaft projecting from the engine E, and the axle shaft 45 is projected to the left and right sides from the rear of the mission case M.
・ The rear wheels 11 and 11, which are the driving wheels, are driven via 46.

Next, the transmission in the transmission case M shifts gears, and after shifting, the rear wheels 11
With reference to FIG. 2, a transmission structure for transmitting power to the vehicle and enabling braking will be described. The power shifted by the transmission case M is transmitted to the differential ring gear 41 of the differential mechanism D via a drive gear. A differential case 39 is fixedly mounted on a side surface of the differential ring gear 41, and differential pinions 42 and 42 that rotate integrally with the differential case 39 and the differential ring gear 41 are loosely fitted inside the differential case 39. On the other hand, the differential side gears 43 and 44 are fitted and inserted into the inner end portions of the left and right axles 45 and 46, and the differential side gears 43 and 44 are meshed with the differential pinion gears 42 and 42 to rotate the differential ring gear 41. Is transmitted to the axles 45 and 46.

Further, the differential mechanism D is, as shown in FIG.
The left and right are pivotally supported by bearings 51 and 52, the differential case 39 is projected to the right of the bearings 51, and several inner disks 53.5 are attached at the case end 39a.
3 is fitted. On the other hand, the axle 46 for driving the right wheel
A cylindrical cylinder portion 56 is arranged at a substantially central portion of the. A boss portion 56 is provided on the right end of the cylinder portion 56.
b is formed and fixed to the axle 46, and the cylinder portion 56
Inner disks 53, 53 having the opening surface at the other end thereof fitted to the case end 39a are covered. An outer disk 54 is provided on the inner peripheral surface of the cylinder portion 56.
54 as shown in FIG.
3 and 3 are arranged alternately. Further, inside the cylinder portion 56, a piston 55 is provided which is fitted on the axle 46 and is slidable left and right while fitting on the inner peripheral surface of the cylinder portion 56. An oil chamber 57 is formed between the side surface 55a of the piston 55 and the inner wall surface 56a of the cylinder portion 56, and constitutes a means for operating the differential lock device 58.

In the oil chamber 60 formed by the outer end of the axle 46 and the transmission case M, a suction hole 60a for sending pressure oil through a hydraulic pump P described later is opened. There is. The end of the axle 46 has an oil passage 4 in the axial direction.
6a is formed and extends from the oil chamber 60 to the oil chamber 57. Then, in order to operate the diff lock device 58, oil is fed from the suction hole 60a, and the fed pressure oil is fed to the oil passage 4
Oil is sent to the oil chamber 57 via 6a. The piston 55 is slid by this pressure oil, and the outer disc 54.5
4 and the inner discs 53, 53 ... are pressed against each other to fix the axle 46 and the differential case 39. Therefore, the differential pinion gear 42, 42 and the differential side gear 43
Cannot rotate, the diff lock device 58 is activated, and the left and right axles 45 and 46 rotate integrally.

Brake mechanisms (braking devices) 49, 49 are arranged on the side portions of the axles 45, 46 as shown in FIG. The brake mechanisms 49, 49 operate in conjunction with the operation of the brake pedals 6, 6 '. As shown in FIG. 5, the brake pedals 6 and 6 ′ have a rotating shaft 14 provided laterally below the step portion 4, and the end portion of a connecting portion 6 a extending from the left brake pedal 6 is connected to the rotating shaft. An arm 15L which is fixed to the rotary shaft 14 and is interlocked with the left brake device 49 is projected from the rotary shaft 14. An end portion of the connecting portion 6'a extending from the right brake pedal 6'is fixed to a cylindrical rotating base portion 6'b, and an arm 15R interlocking with a brake device 49 on the right side of the rotating base portion 6'b. And the rotation base 6'b is rotatably inserted into one end of the rotation shaft 14. The brake pedals 6 and 6'can be connected by the connector 25, and in the connected state, both axles 4
When 5 and 46 are braked and the connector 25 is removed, the left and right axles 45 and 46 can be braked by the individual brake pedals 6 and 6 '. Further, a reduction shaft gear 47, 47 for the left and right rear wheels 11, 11 is fitted to the outer ends of the axles 45, 46, and a support shaft for supporting the rear wheel 11, 11 from the reduction gear 47, 47. The power is transmitted to the rear wheel 1 via a gear fitted to 50
It is transmitted to 1/11.

Next, the control structure of the differential lock device 58 will be described with reference to FIG. The differential lock device 58 feeds pressure oil generated by a hydraulic pump P driven by the power of the engine E through a control valve V controlled by a controller C. The control valve V is a three-port two-position switching type valve, and can be switched between a diff lock operating state and a diff lock releasing state by exciting the solenoid 20. An oil passage 21 connected to the hydraulic pump P and an oil passage 22 which is a return circuit for pressure oil are provided on the primary side of the control valve V. An oil passage 23 is connected to the secondary side of the control valve V. In the diff lock operating state, the oil passage 21 and the oil passage 23 are connected to each other, and the oil is fed into the transmission case M as described above to supply the oil chamber 5 of the diff lock device 58.
The oil is sent to 7. In the differential lock released state, the oil passage 23 and the oil passage 22 are connected to return the pressure oil in the oil chamber 57 to release the differential lock.

The controller C has a structure shown in FIG.
The inclination angle sensor S1 as means for detecting the left and right tilt angles of the machine body shown in FIG. 3 and the switch S2 as means for detecting the high speed traveling by the contact of the auxiliary shift lever 7 are connected. As shown in FIG. 4, the switch S2 is for turning on the switch S2 when the sub-transmission lever 7 is rotated forward as shown by the chain double-dashed line in order to travel at a high speed such as on the road. , The switch S2, the tilt angle sensor S1
Is connected to a controller C that serves as control means.

The controller C has switches SWR and SWL as means for detecting the operating states of the left and right brake pedals 6 and 6 ', and a manual switch S (not shown).
It is connected to W1. As shown in FIG. 5, the switches SWR and SWL are arranged on the lower surface of the step portion 4 so that the contact portions of the switches SWR and SWL project downward, and the contact portions are connected to the connecting portions 6a and 6 '. It is arranged so as to come into contact with a. When the brake pedal 6 (6 ') is depressed, the connecting portion 6a (6'a) switches to the switch SW.
The switch turns on when it is separated from the contact part of L (SWR),
When the connecting portion 6a (6'a) comes into contact with the switches SWR and SWL, the switches are turned off and are input to the controller C, respectively.

Then, the controller C controls as follows. That is, when the value detected by the tilt sensor S1 becomes a tilt equal to or larger than the set angle and one of the brake pedals 6 and 6'is depressed, the solenoid 20 is excited by turning on the switch SWR or SWL. The control valve V is switched to the diff lock operating state. Further, the sub-shift lever 7 is switched to high speed running and the switch S2 is turned on.
If one or both of the brake pedals 6 (6 ') are depressed, the switch SWR or S
WL or both are turned on and the solenoid 20 is turned on
Then, the control valve V is switched to the diff lock operating state. Furthermore, when the manual switch SW1 is turned on, the diff lock can be activated regardless of the depression of the brake pedals 6 and 6'and the operation of the auxiliary shift lever 7.

[0016]

As described above, according to the present invention, even when the connector 25 forgets to connect the brake pedals 6 and 6'when traveling on a sloping ground, the vehicle is tilted more than the set angle. , The tilt angle sensor S1
When the brake pedal 6 or 6'is depressed, the diff lock device 58 is actuated, and the single brake brakes in a straight traveling state without turning to the valley side along the slope. Further, even when the vehicle is traveling at high speed on the road and is not connected by the connector 25 of the left and right brake pedals 6 and 6 ', even if the brake pedal 6 (6') on one side is operated, the differential lock device is operated. 58 works to stop both wheels 11 and 11 by stopping both wheels 11 and 11 without stopping only one wheel 11. Further, the diff lock device 58 operates even in a normal brake operation in which the brake pedals 6 and 6'are connected by the connector,
The braking on one side is large and no one-sided effect occurs. Further, since the diff lock device 58 can be operated by the manual switch SW1, the diff lock can be arbitrarily performed when overcoming the ridge.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view of a differential mechanism and a differential lock mechanism that drive both axles.

FIG. 3 is a circuit diagram for operating the diff lock mechanism of the present invention.

FIG. 4 is a side view showing an auxiliary transmission lever having a switch.

FIG. 5 is a perspective view showing left and right brake pedals provided with switches.

[Explanation of symbols]

 C Controller D Differential mechanism V Control valve S1 Tilt sensor S2 switch SW1 Manual switch SWR switch SWL switch 6 Brake pedal 7 Auxiliary shift lever 11 Rear wheel 58 Diff lock device

Claims (1)

[Claims] 1. A braking device is provided on each of the left and right drive wheels, the braking device is connected to a pair of left and right brake pedals, and both braking devices are independently operated by operating the brake pedals.
Alternatively, in a traveling vehicle in which braking can be performed integrally and a diff lock device is provided between the drive shafts, a means for detecting a lateral inclination angle of the vehicle body, a means for detecting a high-speed shift position on the auxiliary shift lever, and The left and right brake pedals are each equipped with a means for detecting depression, a means for actuating the diff lock device arbitrarily, and a diff lock driving means.The diff lock device is activated when the brake pedal is depressed when traveling over a set angle or at high speed. A differential lock device for a work vehicle provided with control means for controlling the work vehicle.