JPH03532A - Tractor travel transmission device - Google Patents

Abstract

PURPOSE:To facilitate turning performance with switch-over automatically made between four wheel drive and two wheel drive by providing an automatic switch-over means which automatically engages/disengages power transmission to a front wheel power transmission shaft based on the ground speeds of rear wheels. CONSTITUTION:A projected end 56 to which power is transmitted from the trailing end power transmission shaft of a change gear mechanism via an universal joint, a front wheel power transmission shaft and a universal joint 55, permits power to be transmitted to a driven body 37 via a spline shaft 30 of an outer package, the cam 39 of a drive body 41 and a slider 40 and both of clutch pawls 36, and also permits power to be furthermore transmitted to a right and a left front wheel via a front wheel input shaft 23. When the braking operation of one side rear wheel forces the ground speed of the other side rear wheel to be doubled at the time of turning a tractor, front wheels are pushed so as to be advanced, a gap is thereby made between the drive surface of the sliding cam 39 of the slider 40 and the drive surface of the sliding cam 39 of the drive body 41, this permits the slider 40 to be slid so as to come off from the clutch pawls 36 of the drive body 37 so that the front wheel are conditioned to no power transmission. After turning has been over, when the ground speed of the rear wheel is restored to normal ones, both of the clutch pawls 36 are meshed with each other so that the front wheels are conditioned to power transmission.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a traveling transmission device for a tractor.

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION In a so-called four-wheel drive tractor, for example, when braking the negative rear wheel to make a sharp turn, the ground running speed of the other rear wheel is The speed is almost doubled due to the action of the differential mechanism, but since the front wheels are also driven and cannot follow the speed of the rear wheels, this front wheel resistance causes the turning radius to become larger than when the front wheels are not driven. Even if the tractor has a speed increasing mechanism that can increase the speed of the shaft or a switching mechanism that can stop driving the front wheels, it is troublesome to switch these mechanisms at the start of a turn and after the turn. It takes
And it's not easy.

Means for Solving the Problems This invention provides a pair of left and right front and rear wheels (11fl) (2)
Located between +21, these front and rear wheels (1) (1)
(2) (21) Transmission is transmitted from the transmission mechanism (3) to the front side of the transmission case (4) in which the transmission mechanism (3) of 21 is installed, and the transmission is located between the left and right front wheels (1) (1). In a tractor traveling transmission device that is provided with a front wheel transmission shaft (6) in the longitudinal direction that transmits power to a front wheel differential mechanism (5), there is a space between the front wheel transmission shaft (6) and the front wheel differential mechanism (5) ,
Regardless of whether the ground running speed of the front axle (1) (1) is moving forward or backward, when the ground running speed of the rear wheels +21 (2) exceeds a certain range, the front wheel transmission shaft (
The transmission to the rear wheel (2) is automatically set to the inward side, and the transmission to the rear wheel (2)
) (A tractor characterized by being provided with an automatic switching mechanism (7) that automatically switches the transmission to the front wheel transmission shaft (6) to the input side when the ground running speed of the tractor 21 falls below a certain range. The configuration is a traveling transmission device.

Operation of the Invention The speed change transmission mechanism (3) in the speed change transmission case (4) transmits power to the left and right rear wheels 121 (21), and also connects to the front wheel transmission shaft (21).
6), the power is transmitted to the left and right front wheels (11(1)) via the automatic switching mechanism (7) and the front wheel differential mechanism (5).

For example, when braking the negative rear wheel (2) to make a sharp turn,
When the ground running speed of the other rear wheel (2) becomes approximately twice as fast due to the action of the rear wheel differential mechanism, the automatic switching mechanism (7) automatically cuts off the power transmission to the front wheel transmission shaft (6). Since the front wheels (11111) are not driven and the rear wheels (21121) are in two-wheel drive mode, the turning radius is smaller than in the case of four-wheel drive.Also, after turning, the ground speed of the rear wheels +21 (2) becomes normal speed. When restored, the automatic switching mechanism (7) automatically transmits power to the front wheel transmission shaft (6), that is, the four-wheel drive state is established.

Effects of the Invention Due to this effect, there is no need to switch between four-wheel drive and two-wheel drive when turning again, as in the problem described above.
Since it is automatically switched by the automatic switching mechanism (7), turning is therefore facilitated.

In addition, the automatic switching mechanism (7) is not installed inside the transmission case (4), but is installed between the front wheel transmission shaft (6) and the front wheel differential mechanism (5). This has the effect of facilitating switching operations both when assembling and removing.

Example Note that when the vehicle is rotated, the frame forming the front part of the vehicle body (
A prime mover (13) having an output shaft 0 protruding toward the rear is mounted on 1υ, and this prime mover 01 and the frame (l
A front transmission case (I9) is connected to the rear end of υ, which houses a clutch Q41 that is transmitted from the output shaft, and a transmission mechanism (19) that is transmitted from this clutch Q4. At the rear end of the transmission case +16), the transmission mechanism (
A speed change transmission case (4) containing a speed change transmission mechanism (3) that transmits power from the speed change transmission mechanism (3) is connected to the rear end of the speed change transmission case (4). Rear wheel differential mechanism (rear transmission case with internal gear + 1
8, and a pair of left and right lift arms (11
(1'J), and a cylinder case frame containing a hydraulic cylinder that transmits power to the lift arm TFI (turret) is provided.

At the bottom of the frame (10) there is a pin (21) in the front and back direction.
) is provided, and the bottle 12 of this support
11 has a front input force shaft (2) that protrudes rearward, and a front wheel differential mechanism (2) that transmits power to this input shaft (2).
5) and a pair of left and right transmission shafts 1241 + 241 that are transmitted to this differential mechanism (5) are supported in a swingable manner, and the left and right ends of this shaft case 4 are equipped with steering wheels. Front wheel (1) interposed in transmission mechanism Ce (2) (
11, respectively, and on both left and right sides of the rear transmission case (lfl) are rear shaft differential mechanisms (1η) interposed in the transmission cases (5) (5) inside the transmission mechanism that transmits the transmission to the rear shaft differential mechanism (1η). (2) Provide each of (2).

A case (1) having a bearing for supporting the protruding base of the front import force shaft is coupled to the rear surface of the shaft case 4, and the rear end of the shaft case includes An automatic switching mechanism (7) with a seal body at the front end) and a bearing at the rear end
) joins the case category. The bearing (■) has a cylindrical part 0υ having a spline (to) on the front part of the inner circumferential surface, and a cylindrical part 0
An automatic switching mechanism (7) consisting of a wall (support) at the rear end of D and a boss (to) that projects rearward from this wall (to)
The boss portion of the exterior body is supported.

A protruding shaft (#) which protrudes forward from the universal shaft joint (π) on the rear side of the boss part (G3) is spline-coupled to the inner circumferential surface of the boss part 03, and is provided at the front end of this protruding shaft (σ). The small-diameter portion of the rear end of the front shaft input shaft force is supported in the bearing hole (to), and a ladder-shaped clutch claw radially extends on the front surface of the flange-shaped portion at the rear of the input shaft (to). The boss portion of the driven body having Og... is spline-coupled.

Further, on the front import force shaft (to) on the front side of the driven body (A), a bearing (to) that can slide and rotate freely with respect to this front import force shaft (to) is provided, and this bearing (to) ), on the rear surface of the flange-like part there is a clutch pawl (to) (to) that engages with the Kurarechi pawl eeee... and on the front surface of the flange-like part from the clutch pawl aQo9... Also, the boss portion of the sliding body (G) having a large ladder-shaped sliding cam (T) is fixed, and the spline (T) of the cylindrical portion 011 is fixed.
A ring-shaped sliding body @υ having a sliding cam (to) (to) that meshes with the sliding cam @(to)... is fixed to the rear surface of the outer casing (to). Body wall (support) and sliding body (g)
A spring is provided between the slider and the flange-shaped portion to resiliently bias the slider toward the front.

In addition, a ball mallet is inserted into the outer peripheral surface of the spline engagement provided on the front force shaft (toward) on the front side of the sliding body (9).
A locking body ((lk spline slidably provided,
On the outer periphery of this locking body CI"1), a ring body having a hole that supports the ball so as to be movable in a direction perpendicular to the front force axis (to) is provided so as to be immovable back and forth. , On the outer periphery of this ring body (〃), there is provided a vine regulating body (nine layers) that allows the ball haze to fit into and disengage from the image tθ of the locking body (μ) by sliding against the ring body.

The terminal end transmission shaft (to) of the speed change transmission mechanism (3) that protrudes forward from the speed change transmission case (4) and the flexible shaft I-1 have a universal shaft joint (r, , c) are connected by a front wheel transmission shaft (6).

Next, the effect will be explained. The clutch α which is transmitted to the output axle load of the prime mover (13), the transmission mechanism (1'El, the variable speed transmission mechanism (3), the rear wheel differential mechanism (1η) and the transmission case Power is transmitted to the rear wheels +21 +21.

On the other hand, the terminal transmission shaft Q of the variable speed transmission mechanism (3)! The protruding shaft C9, which is transmitted through the universal joint shaft, the front wheel transmission shaft (6), and the universal joint shaft, is connected to the spline of the exterior body (] [
D, sliding cam of drive body 11D @ (to)..., sliding body (
) sliding cam @ (to)... and both clutch claws (to)
(to) ..., and further from the driven body to the front input power shaft (to), the front wheel differential mechanism (5), the transmission shaft H (241 and the steering transmission mechanism l2e (2) The power is transmitted to the left and right front wheels (1) (1) via.

As mentioned above, the front wheel + 1) (1) During driving, the driving body 6υ sliding cam @ (to) ... rotates in one direction, and the sliding cam receives resistance from the driving surface of the sliding cam (towards the seal body). The driven surfaces of the sliding cams between the moving bodies @ (to) are in contact with each other, and the thrust of the cam slope causes the sliding body (A) to slide backward against the spring (4). Clutch pawl Oe
(to)... and the driven clutch pawl (to) (to)...
・The mesh is maintained and the transmission is transmitted from the sliding body (G) like a driven body.

For example, when a tractor turns, the braking operation of the - side rear wheel (2) causes the rear wheel differential mechanism (+7) to act on the other side rear axle (2).
) when the ground running speed of
A gap is created between the driven surface of the drive body II) and the drive surface of the sliding cam 4, and the thrust from the cam slope is lost, so the sliding body ■ slides forward due to the spring force. The clutch pawl @ (g) of the sliding body (a) will be disengaged from the clutch pawl CIQC3G of the driven body, and therefore the front shaft 11) (11 will be in a free state where no power is transmitted. , after turning, when the ground running speed of the rear wheels 12) (2) is restored to normal speed, there is no reverse power transmission from the front wheels + IHI), so the same action as above causes both clutch pawls OQ.
(to)... are engaged, and the front wheels (1) (1) are in a transmission state.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a side sectional view, FIGS. 2 and 3 are partial side sectional views, and FIG. 4 is an overall side view. In the figure, (1) is the front wheel, (2) is the rear wheel, (3) is the transmission mechanism, (4) is the transmission case, (5) is the front differential mechanism, and (6) is the front wheel transmission shaft. , (7) shows an automatic switching mechanism.

Claims (1)

[Claims] It is located between a pair of left and right front and rear wheels (1), (1), (2) and (2), and controls the transmission mechanism (3) for these front and rear wheels (1), (1), (2), and (2). A front wheel differential mechanism (5) is located on the front side of the internally installed transmission case (4) and is transmitted from the transmission mechanism (3) and located between the left and right front wheels (1).
In a tractor traveling transmission device that is provided with a front wheel transmission shaft (6) in the longitudinal direction that transmits power to the front wheels, the front wheels (1) (1) )
When the ground running speed of the rear wheels (2) (2) exceeds a certain range, whether in forward or reverse direction, the power transmission to the front wheel transmission shaft (6) is automatically stopped. an automatic switching mechanism ( 7) A traveling transmission device for a tractor.