JPS63240427A - Four-wheel-drive type working vehicle - Google Patents

Abstract

PURPOSE:To improve the weight balance of a machine body by linkingly placing a front wheel speed change gear on the power input part of a front axle case in the captioned vehicle in which power from a transmission provided in the rear of said machine body is transmitted to front wheels via said front wheel speed change gear. CONSTITUTION:In an agricultural tractor, the power of an engine 4 placed on the front part of a machine body frame 3 is transmitted from a main clutch 5 to rear wheels 2 via a transmission 6 formed with main and subspeed change gears placed in the rear of the machine body frame 3. Also, power which is branched off of the sub-speed change gear of the transmission 6 is transmitted from a front wheel output shaft 15 to front wheels 1 via a front wheel speed change gear 10. And, in this case, the front wheel speed change gear 10 the acceleration driving side of which is formed with a multiple disk friction clutch (figure omitted) is placed on the power input part of a front axle case 11. Thereby, a structure without the extremely lopsided supporting load of the front and rear wheels can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the arrangement structure of a front wheel transmission in a four-wheel drive type working vehicle.

[Conventional technology]

In recent years, front wheel transmission devices have been developed that can switch between a standard drive state in which power is transmitted to the front wheels at a drive speed approximately equal to the rear wheel drive speed, and an increased speed drive state in which power is transmitted to the front wheels at a drive speed greater than the rear wheel drive speed. Equipped with four-wheel drive vehicles, which switch the front wheel transmission to the speed-increasing drive side when turning, they can easily make sharp turns without disturbing the ground, and even on soft ground. be.

In the agricultural tractor, which is an example of the above-mentioned work vehicle, the speed-increasing drive side of the front wheel transmission installed in the transmission at the rear of the machine is configured as a mechanically operated friction clutch, and the friction clutch and the steering handle are connected mechanically. There is a structure in which a friction clutch is engaged and operated by a steering operation of the steering wheel at a set angle or more in conjunction with the steering wheel.

[Problem that the invention seeks to solve]

Since the power branched from the driving transmission installed at the rear of the aircraft is relatively high-speed and low-torque, even if the speed-increasing drive side of the front wheel transmission is configured as a mechanically operated friction clutch as described above, the steering wheel will not reach the control handle. The operation is not very heavy, and the switching operation from the standard drive side to the increased speed drive side is performed smoothly, but the weight of the rear side of the aircraft tends to be heavier than the front side.

In the agricultural tractors mentioned above, a working device such as a rotary tiller is often connected to the rear of the machine, and when the working device is connected to the rear of the machine in this way, the weight balance of the machine becomes even more biased towards the rear. turn into. If the support load of the front wheels becomes too small in this way, the driving force of the front wheels will not be sufficiently transmitted to the ground, which will reduce the advantages of four-wheel drive and also cause the front wheel transmission to lose its effectiveness.

Therefore, in order to prevent the above-mentioned problems, it is necessary to attach a balance weight of sufficient weight to the front of the aircraft, but this is not a preferable measure because it increases the weight of the entire aircraft.

The present invention has focused on the above-mentioned problem, and an object of the present invention is to provide a front wheel transmission capable of fully demonstrating its effectiveness without the need for installing particularly heavy balance weights.

[Means for solving problems]

A feature of the present invention is that, in the four-wheel drive type work vehicle as described above, the front wheel transmission is connected to the power input section of the front axle case, and its functions and effects are as follows. .

[For production]

With the configuration described above, the weight of the rear part of the machine body becomes lighter and the weight of the front part of the machine body becomes heavier, so that the load supported by the front and rear wheels can be configured to be balanced without being extremely biased.

In addition, since the power at the power input section of the front axle case is relatively high rotation and low torque before being decelerated by the front wheel differential mechanism or deceleration mechanism inside the front axle case, the speed increasing drive side of the front wheel transmission is Even if it is configured as a friction clutch and mechanically linked with the steering handle, the operation of the steering handle will not be too heavy. Furthermore, even if the friction clutch is hydraulically operated, since the transmitted torque is low, the friction clutch and the pressure oil supply system can be constructed with relatively low capacities.

〔Effect of the invention〕

As described above, it is possible to configure the weight balance of the aircraft to be favorable for a four-wheel drive vehicle while keeping the transmitted torque through the front wheel transmission low, and it is possible to fully demonstrate the performance of the front wheel transmission when turning. At the same time, the load acting on the operating system of the front wheel transmission can be reduced, and the durability of the operating system can be improved.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A four-wheel drive agricultural tractor, which is one embodiment of the present invention, will be described below with reference to the drawings.

As shown in Fig. 2, an engine (4), a main clutch ( 5) A transmission (6) and a control unit (7) are mounted on the rear of the aircraft, and a lift arm (8) connects various work devices such as a rotary tiller to the rear of the aircraft so that they can be raised and lowered, and power is transmitted to the work devices. A four-wheel drive agricultural tractor is configured with a PTO shaft (9).

Next, talking about the power transmission system of agricultural tractors, as shown in the figure, the power from the engine (4) is transmitted from the main clutch (5) to the main transmission and the sub-transmission (not shown).
The power is sent to the transmission (6), which is composed of The transmission is transmitted to the front wheel transmission (10) connected to the axle case (11), and the front wheel (1
).

Next, the front wheel transmission (10) will be explained in detail.
As shown in FIGS. 1 and 2, an input shaft (14) is supported concentrically and relatively rotatably with respect to the differential drive shaft (13) of the front wheel differential mechanism (12). The front export force shaft (15) is connected to the input shaft (14), and a front wheel transmission (
10) is configured.

To be more specific, a multi-disc friction clutch (16) is freely fitted onto the input shaft (14), and the differential drive shaft (
13) and the input shaft (14), a transmission shaft (17) is provided in parallel with the first gear (18) fixed to one end of the transmission shaft (17), and the friction clutch (16) is provided with a transmission shaft (17). The speed-increasing drive gear (19) meshes with the second gear (20) fixed to the other end of the transmission shaft (17) and the speed-increasing driven gear (21) fixed to the differential drive shaft (13). They are interlocking. On the other hand, a shift member (22) is slidably attached to the end of the input shaft (14) with a spline structure, and the control handle (23) and the shift member (22) are connected to each other by a linkage mechanism (24). are interlocked and connected via.

In a normal straight-ahead state, the shift member (22) is connected to the differential drive shaft (
13) The differential drive shaft (13) and the input shaft (14) are directly connected by engaging with a spline portion (13a) provided at the end. In this state, power is transmitted to the front and rear wheels (1),
The drive speeds (2) are transmitted to the front wheel differential mechanism (12) in a standard drive state where the drive speeds are substantially equal. And the control handle (
23) above the set angle, the shift member (22) engages the spline portion (13) of the differential drive shaft (13).
a) Push the friction clutch (16) further away. In such a state, the power is transferred to the friction clutch (1
6), the drive speed of the front wheels (1) is transmitted to the differential drive shaft (13) via the transmission shaft (17) in an accelerated drive state in which the drive speed of the front wheels (1) is increased more than that of the rear wheels (2).

Furthermore, the entire front wheel transmission (10) is mounted on the front axle case (10).
1) and remove the front export force shaft (15) from the differential drive shaft (1).
3), the front wheel transmission (1
0) can be easily changed to a type of agricultural tractor that is not equipped with.

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of the drawing]

The drawings show an embodiment of a four-wheel drive type work vehicle according to the present invention,
FIG. 1 is a plan view of the vicinity of the front wheel transmission, and FIG. 2 is a side view of the entire agricultural tractor. (1)...Front wheel, (2)...Rear wheel, (
6)...Transmission, (10)...
...Front wheel transmission, (11)...Front axle case, (16)...Friction clutch.

Claims (1)

[Claims] The front wheels (1) transmit power from the transmission (6) installed at the rear of the aircraft to the freely steerable front wheels (1).
A front wheel transmission (10) that switches between a standard drive state in which the drive speeds of the rear wheels (2) and the rear wheels (2) are substantially equal, and an increased speed drive state in which the drive speeds of the front wheels (1) are greater than the rear wheels (2). A four-wheel drive working vehicle is provided with a multi-plate friction clutch (16) on the speed increasing drive side of the front wheel transmission (10), the front wheel transmission (10) being connected to the front axle. A four-wheel drive work vehicle connected to the power input section of the case (11).