JPS6230941B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a defrock device for a traveling vehicle such as a tractor or a rice transplanter.

In a conventional differential lock device, differential side gears are fitted to the left and right wheel drive shafts, which are rotatably installed in the transmission case, respectively, and each of the differential side gears is fitted onto the outside of the differential side gear so as to be rotatable. A clutch pawl is provided at one end of the differential case, and the differential clutch, which is spline-fitted to the wheel drive shaft in the same direction, is moved against a return spring to engage with the clutch pawl. The engagement of this differential clutch is carried out by depressing the differential pedal protruding near the steps of the vehicle, so the brake pedal, various gear shift levers, etc. are arranged, which occupies less space. The area near this step is now even narrower due to the use of the defrock pedal, making it extremely inconvenient to operate. Furthermore, there is the annoyance of having to keep pressing the defrok pedal during defroc operation.

Therefore, in this invention, the defrock operation is self-maintained using pressure oil as a driving source.
Furthermore, the locking mechanism has been improved so that it can be easily released by operating the turning operation means of the vehicle.

To explain one embodiment, differential side gears 3 and 4 are fitted to the left and right wheel drive shafts 1 and 2, respectively, and a differential case 5 in which the differential side gears 3 and 4 are rotatably housed has bearings. Bevel gears 9, 9, which are supported on transmission case 8 by terminals 6 and 7 and are rotatably housed in differential case 5, are meshed with differential side gears 3 and 4, and the rotational power of an engine (not shown) is transmitted through a transmission mechanism. A differential gear mechanism 12 is constructed by meshing a drive pinion 10 driven by a drive pinion 10 with a ring gear 11 fixed to a differential case 5.

Then, the differential clutch 13 is fitted to the spline boss 2a of one of the front wheel drive shafts 2 so as to be movable only in the axial direction, the cylinder 15 is attached to the wall 14 of the transmission case 8, and the piston portion is inserted into the cylinder 15. The fitted piston 16 is connected to the differential clutch 13
The piston 16 is loosely fitted into the cylindrical portion 13a of the cylinder 15, and is prevented from rotating with respect to the cylinder 15. Therefore, the differential clutch 13 can freely rotate with respect to the piston 16, but cannot rotate in the axial direction. It is formed so that it can move as one body with the piston 16,
Spring seat 17 attached to piston 16 and cylinder 1
If the differential clutch pawl 13b of the clutch 13 is separated from the clutch pawl 5a of the differential case 5 by the return spring 18 stretched between the outside of the piston 16 and pressure oil is supplied to the cylinder chamber 15a on the back of the piston 16. The differential clutch mechanism 19 is configured such that the piston 16 pushes the differential clutch 13 via the thrust collar 35, thereby causing the clutch pawls 13b and 5a to engage. In addition, in the illustration, an oil passage 14a provided in the wall body 14 and an oil passage 15a provided in the cylinder 15 are communicated with the cylinder chamber 15a.

Then, as shown in FIG.
The pressure oil in the cylinder chamber 15a is supplied to the cylinder chamber 15a, or the pressure oil in the cylinder chamber 15a is discharged to the tank 20.The power supply is turned on by pressing a push button type switch 24 provided on the meter panel 23.
Since _E1 energizes relay L, when left and right brake pedals 25, 26 are not depressed and the steering wheel 27 is turned within a certain angle, switches 28, 29, 30 are normally closed. The power source E ₂ energizes the electromagnetic solenoid 22 a of the switching valve 22 via the contacts 28 b, 29 b, and 30 b while the relay L is self-held by the normally open contact la, and the pressure oil of the pump 21 flows into the cylinder chamber. 1
The switching valve 22 operates so that the power is supplied to the brake pedal 5a, and the deflock indicator light _P1 also lights up, resulting in a deflock state. In this deflock state, depressing either the brake pedals 25 or 26 will take action. Since the normally closed contact 28b or 29b opens, the self-holding of the relay L is released and the electromagnetic solenoid 22a is de-energized, or the steering wheel 27 is turned beyond a predetermined angle without depressing the brake pedals 25, 26. When the actuating piece 31 opens the normally closed contact 30b of the switch 30, the electromagnetic solenoid 22a is de-energized.
The pressure oil is returned to the tank 20. Then, when both the left and right brake pedals 25 and 26 are depressed, the normally open contacts 2 of the switches 28 and 29
Since both 8a and 29a close, the relay R is self-held by the normally open contact _ra , and the electromagnetic solenoid 22a continues to be energized, so the switching valve 22 is connected and configured so that the deflock state is maintained.
Further, turning operation means such as these brake pedals 25, 26 or a steering handle 27 are provided.

Therefore, in the field, while slipping of the left and right wheels can be well prevented by operating the defrock by pressing the switch 24, when turning the wheels, the slipping of the left and right wheels can be prevented by operating the steering handle 27 or by depressing one of the brake pedals. Since the differential lock is immediately released, accidents caused by forgetting to release the differential lock are eliminated, making the operation safer and more convenient.

In addition, when driving on the road, the left and right brake pedals 2
Even if the left and right brake mechanisms 34 are activated by pressing the left and right brake pedals 5 and 26 together, if the left and right brake pedals 25 and 26 are pressed at the same time, a deflock condition will occur, so the difference in wear between the left and right brake mechanisms 34 or It is safe even if the brake is in a one-sided state due to insufficient adjustment of the length of the brake rod.

Although not shown in the drawings, this deflock release can be done by using a tumbler type switch 24 or a type that is turned on by pressing twice, thereby eliminating the need for self-holding by the relay L as described above. This can also be done by means of a release means configured as such.

Further, symbols P ₂ and P ₃ are brake indicator lights.

In addition, in FIG. 2, the wheel drive shafts 1 and 2 are
Drive the wheel shaft 33 via the planetary reduction mechanism 32,
A multi-plate brake mechanism 34 is provided on the wheel drive shafts 1 and 2.
has been established.

The differential lock device for a traveling vehicle according to the present invention includes:
The differential clutch of the differential gear mechanism that drives the left and right wheels, respectively, can be turned on and off by pressure oil supplied to and discharged from a switching valve that is energized through an electric circuit configured to allow self-holding operation. Since the switching valve is configured to be able to switch to the disengaged state of the deflock clutch by operating the reversing operation means, when the vehicle is traveling straight, the self-holding operation of the electric circuit maintains the deflock state and the vehicle remains in the disengaged state. Improved straightness and increased traction,
When turning the vehicle around, operating the turning operation means releases the deflock state, allowing the vehicle to make sharp turns. This not only simplifies the process with less effort, but also simplifies the structure of the operating means and equipment arrangement. This not only made the defrock operation easier with less effort, but also simplified the structure of the operating means and equipment layout.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a side view of a traveling vehicle, FIG. 2 is a cross-sectional plan view of the vicinity of the differential gear mechanism and the deflock mechanism, and FIG. 3 is a control circuit diagram. Description of symbols, 1, 2...Wheel drive shaft, 2a...Spline boss, 3, 4...Differential side gear, 5...
...Differential case, 5a, 13b...Clutch pawl,
6, 7... Bearing, 8... Mission case, 9... Bevel gear, 10... Drive pinion, 11... Ring gear, 12... Differential gear mechanism, 13... Differential clutch, 13a... Cylindrical part,
14...Wall body, 14a, 15b...Oil passage, 15...
...Cylinder, 15a...Cylinder chamber, 16...Piston, 17...Spring seat, 18...Return spring, 1
9... Defrot clutch mechanism, 20... Tank, 21... Pump, 22... Switching valve, 22a...
...Electromagnetic solenoid, 24, 28, 29, 30...
Switch, 25, 26... Brake pedal, 27
... Steering handle, 28a, 29a,
la, r _a ... Normally open contact, 28b, 29b, 30b
... Normally closed contact, 31 ... Operating piece, 32 ... Planetary reduction mechanism, 33 ... Wheel shaft, 34 ... Brake mechanism, 35 ... Thrust collar, E ₁ , E ₂ ... Power supply, L, R ... ...Relay, P ₁ ... Defrot lock indicator light, P ₂ , P ₃ ... Brake indicator light.

Claims (1)

[Claims] 1 The differential clutch of the differential gear mechanism that drives the left and right wheels, respectively, is turned on and off by pressure oil supplied and discharged by a switching valve that is energized and activated via an electric circuit configured to allow self-holding operation. 1. A differential lock device for a traveling vehicle, which is configured such that the switching valve can be switched to a differential clutch disengaged state by operating a reversing operation means.