JPH0620689Y2 - Turning mechanism in front-wheel steering vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Use The present invention relates to a turning mechanism in a front-wheel steering vehicle.

(B) Conventional Technology Conventionally, various types of turning mechanisms for front-wheel steering vehicles have been developed for the purpose of improving workability in a field of a tractor or the like, and particularly reducing the turning radius when turning. As one form of such a turning mechanism, there is a front wheel inner / outer wheel actuation type.

(C) Problems to be solved by the device However, the conventional front-wheel / outer-wheel actuated drive type turning mechanism has the following problems.

Since the speed increasing mechanism is installed in the transmission located behind the machine, a transmission shaft is required in addition to the front wheel drive shaft, and the transmission shaft is damaged by obstacles etc. under the vehicle body during traveling. May occur.

Since the speed-up mechanism is a constant-mesh clutch, the speed may suddenly increase and slip depending on the field conditions, causing the soil to rotate around.

An object of the present invention is to provide a turning mechanism in a front wheel steering vehicle that can solve the above problems.

(D) Means for Solving the Problems The present invention is directed to a cylindrical casing, a pinion shaft having a front end connected to a front wheel differential device, and a pinion shaft, in which a speed increasing switching mechanism is arranged in the cylindrical casing. While connecting the input side to the front wheel drive shaft and the intermediate rotary cylinder that is concentrically arranged around it,
A speed-up diff mechanism that connects the output side to the pinion shaft and the rear end of the intermediate rotary cylinder, a multi-plate clutch that locks and unlocks the intermediate rotary cylinder in a tubular casing, and a steering mechanism that is interlocked and intermediately connected to the pinion shaft. The present invention relates to a turning mechanism in a front-wheel steering vehicle, which comprises a sliding cam body for connecting / disconnecting a rotary cylinder and for fixing / releasing an intermediate rotary cylinder to a tubular casing.

(E) Operation and effects With the above-described configuration, the present invention has the following operations and effects.

Since the multi-disc clutch can be gradually operated by the sliding cam body that is interlocked with the front wheel steering mechanism, the differential state of the left and right front wheels corresponding to the field conditions can be obtained together with the speed increasing differential mechanism.

If the steering wheel turning angle is outside the certain range, the difference between the left and right wheels will increase steadily, and the speed difference will gradually occur from the beginning of turning, and there will be no shock and stable turning will be possible. Does not hurt

Since the rotation of the joint portion between the front wheel drive shaft and the speed increase switching mechanism is not accelerated, noise is reduced.

(F) Embodiment Hereinafter, the present invention will be specifically described based on an embodiment shown in the accompanying drawings.

In FIG. 1, A is a tractor, and the tractor A has a front wheel 2 and a rear wheel 3 attached to its front and rear portions, respectively, and both the front wheel 2 and the rear wheel 3 will be described below. It is driven by a drive mechanism.

That is, in the drive system diagram shown in FIG. 2, 3 is an engine, 4 is a main clutch, 5 is a main transmission, 6 is an auxiliary transmission, and 7 is a rear wheel differential device. Is linked to each rear wheel 2 via a final reduction gear 9. Reference numeral 10 is a rear wheel brake provided on the outer end of each differential yoke shaft 8.

In the above structure, the main transmission device 5 and the auxiliary transmission device 6
Is built into the mission case.

A front wheel drive system 11 includes a front wheel drive shaft 14 connected to the auxiliary transmission 6 through a gear train 12 and a universal joint 13, and a front wheel differential device 15 connected to the front wheel drive shaft 14. Each differential yoke shaft 16 of the differential device 15 is connected to the front wheel 1 via a gear train 17, and the front wheel 1 is steerable around a kingpin.

The present invention is characterized in that, in the front wheel drive system 11, a speed-increasing switching mechanism B is provided between the front wheel drive shaft 14 and the front wheel differential device 15.

The configuration of the speed increasing switching mechanism B will be described in detail with reference to FIG.

In the figure, reference numeral 21 denotes a front axle case that has a front wheel differential device 15 built-in and is swingably supported to the body 22 by a case swing support portion 21a in the left and right directions. The base end of the tubular casing 20 extending rearward is provided so as to project.
The intermediate part is supported by a bearing 24 whose upper end is fixed to the machine frame 22.

Reference numerals 25 and 26 denote an oil pan and a clutch housing provided at the bottom of the machine body 22, and the tubular casing 20 is arranged so as not to contact them.

Further, the tubular casing 20 has a pinion shaft 29, which has a bevel gear 27 meshing with a gear train of the front wheel differential device 15 at a front end, from the front wheel differential device 15 toward the front wheel drive shaft 14, and a rear end thereof. A speed increasing / switching mechanism input shaft 30 in which the front wheel drive shaft 14 and the front wheel drive shaft 14 are linked by a universal joint 13 is arranged in series.

Further, 31 is an intermediate rotary cylinder that is concentrically and relatively rotatably attached over substantially the entire length of the pinion shaft 29.The intermediate rotary cylinder 31 is slidable in the axial direction at its front end, but it is a spline for the intermediate rotary cylinder. Sliding cam body that rotates integrally with 31
32 is attached, and the sliding cam body 32 is a dog clutch.
Flange 34 fixed in the middle of pinion shaft 29 via 33
Is detachably engaged with.

The sliding cam body 32 is moved in the axial direction by a sliding fork 36 slidably supported by a pivot shaft 35. The swing fork 36 is interlocked with a steering mechanism (not shown) and The clutch 33 can be engaged and disengaged.

Further, 37 is the middle of the intermediate rotary cylinder 31, and the sliding cam body 32
Is a multi-disc clutch attached to a position adjacent to, and the multi-disc clutch 37 fixes the intermediate rotary cylinder 31 to the tubular casing 20 by compressing the spring 38 by the axial movement of the sliding cam body 32. However, the rotation can be stopped.

Further, 40 is a speed increasing diff mechanism provided at the rear end of the pinion shaft 29, and the diff mechanism 40 concentrically and rotationally mounts a rotary housing 41 around the rear end of the pinion shaft 29. A bevel gear 42 having an axis line in the direction orthogonal to the axis line of the pinion shaft 29 is attached to the inner surface, and the front and rear surfaces of the bevel gear 42 are fixed to the rear end of the pinion shaft 29, respectively, and the rear end of the intermediate rotation cylinder 31. To be engaged with a bevel gear 44 formed integrally with the rotary housing 41, and further, an internal gear portion provided at the front end of the rotary housing 41 is made to mesh with an external gear portion formed at the rear end of the speed increasing switching mechanism input shaft 30. There is.

Next, the operation of the speed increasing switching mechanism B having the above configuration will be described.

When the engine 3 is started and the main clutch 4 is connected, the power of the engine 3 passes through the main clutch 4, the main transmission device 5, the auxiliary transmission device 6, the rear wheel differential device 7 and the final reduction gear device 9 to the rear wheels 2 respectively. Transmitted to.

On the other hand, since it is transmitted from the auxiliary transmission 6 to each front wheel 1 via the front wheel drive shaft 14, the speed increase switching mechanism B, and the front wheel differential device 15, the tractor A drives the four wheels of the front wheel 1 and the rear wheel 2. It will run as a wheel.

Then, when traveling straight ahead, the front wheels 1 and the rear wheels are driven at the same speed, which will be described below with reference to the drive system explanatory diagram.

That is, since the steering mechanism is not steered to the extent that the swing fork 36 is activated, the multi-plate clutch 37 is not activated,
The intermediate rotary cylinder 31 is not fixed to the tubular casing 21,
On the other hand, the intermediate rotating cylinder 31 is integrally connected to the pinion shaft 29 by the dog clutch 33.

For this reason, the rotation of the front wheel drive shaft 14 depends on the speed increase switching mechanism input shaft.
Transmitted from 30 to the rotary housing 41, but the bevel gear 4
2, the bevel gear 43, the pinion shaft 29, the bevel gear 44, and the intermediate rotary cylinder 31 rotate at the same speed as the front wheel drive shaft 14, and then the front wheel 1 via the front wheel differential device 15 and the front wheel yoke shaft 16.
Will be transmitted to.

On the other hand, when the steering mechanism is steered to the extent that the swing hawk 36 is operated, the multi-plate clutch 37 is actuated, the intermediate rotary cylinder 31 is fixed to the tubular casing 21, and the dog clutch 33 is disengaged. Depending on the pinion shaft 29 and the intermediate rotary cylinder
The connection with 31 will be released.

For this reason, the rotation of the front wheel drive shaft 14 depends on the speed increase switching mechanism input shaft.
Transmitted from the rotary housing 41 to the bevel gear 42
→ Bevel gear 43 → Pinion shaft 29 → Only the transmission path of the front axle case 21 is active, and the relative rotation between this and the rotary housing 41 forms a differential gear mechanism,
The pinion shaft 29 rotates at twice the speed of the front wheel drive shaft 14,
After that, it is transmitted to the front wheels 1 via the front wheel differential device 15 and the front wheel yoke shaft 16.

Therefore, the tractor A can turn at a small turning radius without slipping.

Further, in the above-mentioned configuration, since the other components except the speed-increasing switching mechanism B have standard specifications, a swivel mechanism capable of small swiveling can be easily and inexpensively configured, and retrofitting (option) is also easy. Further, since the speed-increasing switching mechanism B is arranged behind the front axle case 21, it is possible to eliminate an unnecessary transmission portion, which does not hinder traveling. Further, since the speed increasing / switching mechanism B is provided on the front side, the weight balance between the front and the rear is improved, and the center of turning comes to the front side as compared with the conventional case, so that the turning radius can be reduced.

[Brief description of drawings]

FIG. 1 is a side view of a front wheel steering vehicle including a turning mechanism according to the present invention, FIG. 2 is a drive system diagram, and FIG. 3 is an enlarged structural explanatory view of the turning mechanism. In the figure, A: tractor B: speed increase switching mechanism 14: front wheel drive shaft 15: front wheel differential device 20: tubular casing 21: front axle case 22: machine body 29: pinion shaft 31: intermediate rotary shaft 32: sliding cam body 22: Aircraft 37: Multi-plate clutch 40: Speed increasing diff mechanism

Claims (1)

[Scope of utility model registration request] 1. A speed increasing switching mechanism (B) is provided in a tubular casing (20).
A pinion shaft (29) having a front end connected to the front wheel differential device (15), and a pinion shaft (29).
Connect the input side to the front wheel drive shaft (14) and the output side to the pinion shaft (29) and the rear end of the intermediate rotary cylinder (31) with the intermediate rotary cylinder (31) arranged concentrically around The speed increasing diff mechanism (40), the multi-disc clutch (37) for fixing and releasing the intermediate rotary cylinder (31) to the tubular casing (20), and the pinion shaft (29) linked to the steering mechanism. A front wheel steering characterized by comprising a sliding cam body (32) for connecting and disconnecting the intermediate rotary cylinder (31) and for fixing and releasing the intermediate rotary cylinder (31) in the tubular casing (20). A turning mechanism in a vehicle.