JPS58122230A - Control mechanism for front wheel rotation speed of agricultural four-wheeled tractor - Google Patents

Abstract

PURPOSE:To obtain four-wheeled drive safely in any condition by means of causing the circumferential speed of a front wheel and a rear wheel to be equal by equipping at least two stages-transmission mechanism between the shafts of the front wheel and the rear wheel. CONSTITUTION:A transmission 9 is equipped between the driving shafts 7 and 8 of a rear wheel and a front wheel. Consequently, the revolution of the driving shaft 7 of the rear wheel is transmitted to a gear 20 from a gear 19. The revolution force transmitted as above, is further transmitted to a gear 12 or a gear 13 from either of a high speed gear 10 or a low speed gear 11 fitted to subshaft 21, and the front wheel driving shaft 8 is rotated. The selection for these gear- engagement is achieved by regulating the position of the clutch 23 equipped between the gears 12, 13, and the position of the clutch 23 is requlated by the operation of a shift-lever.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control mechanism that independently adjusts the rotational speed of the front wheels of a four-wheel drive agricultural tractor.

An agricultural 4-wheel drive tractor used for plowing and VC pulling is used for plowing using agricultural equipment 1 such as a bottom plow (as shown in Fig. 1), or for loading agricultural products as shown in Fig. 2. It is used to transport loaded carts 2, etc. on the Jf circuit. These agricultural 4-wheel drive tractors (hereinafter simply referred to as tractors) are composed of a combination of 111 wheels 4 formed with a small diameter and a rear wheel 5 formed with a large diameter.In particular, the rear wheels 5Fi are large enough to be used in soft fields. '1 We use low-pressure tires that can exert driving force. On the other hand, set g+ to ring 4
Since the diameters of rear wheel 5 and rear wheel 5 are different, when driving these two wheels at the same time (for example, Blv4 @drive), M
Adjust the degree of rotation so that the circumferential speed of iT 4 and the rear wheel 50 are equal, and make sure that the front wheel 4 or the rear wheel 5 does not slip easily. + [! I am considering it. Therefore, in the past, the difference in the rotation radius of the front wheels 4 and the rear wheels 50 was taken into account in advance, and the gear ratios at the front output shaft and rear output wheels of the power transmission device (not shown) were determined to equalize the circumferential speeds of both wheels. It is designed to do so.

However, when the willow tractor 3 is used for military use on the cart 2, the loading force of the cart 2 acts as a reaction force against the military use of the tractor 3.
This appears as a force W that tries to push down the connecting portion 6 of the .

When such a downward force W is generated, the rear wheel 5 tries to become flat as shown in the imaginary line in FIG. Since it becomes a stick, the center of rotation on the side side P-go should be brought closer to the road surface by the same distance as the rotation axis (P
'). That is, the rear wheel rotates with a new N rotation radius r that is smaller than the rotation radius R by the above flatness. Therefore, even if the same rotational speed as before is given to the rear wheel 5, since it rotates with a rotation radius r, the peripheral speed of the rear wheel 5 will be lower than that before flattening. Distance is knowledge (Naru. However, M
Since the i'1 wheel 4 cannot bear the influence of the above-mentioned pushing down force W,
Since it maintains its diameter, it rotates at the designed circumferential speed, and the forward speed per revolution does not change. That is, if the running speed of the front wheel 4 and the rear wheel 5 is relative to 1-, then the front wheel 4 (tllll
The rear wheels tend to shift faster than the rear wheels, but since the load is less on the front wheels 4, the front wheels 4 will slip because they are faster than the rear wheels 5. Slips cause tire wear, so in the past, active drive of the front wheels 4 was canceled and only the rear wheels 5 were driven in two-wheel drive, or the drive of wheels 1 and 4 (Ill was intermittent) to reduce tire wear. As a result, the traction force of the four-wheel drive could not be fully utilized, leading to unstable driving.Also, when climbing up a steep slope at the 3rd level. In this explanatory diagram, the weight of the tractor 8 itself is heavily applied to the rear wheels 5, so the rear wheels 5 become flat (imaginary line) in the same way as in the case of i[ and f'i5J, and the rear wheels The turning radius of 5 is shortened. Therefore, the rear wheel circumferential speed decreases compared to 4 Vc, and slip occurs on the 4 side of t3ff for the same reason as above. In this case as well, avoid slipping. Therefore, it is conceivable to cancel the product FM drive of the front wheels 4, but since it is not possible to climb up the slope with only the climbing force of the rear wheels 5, in reality, it is necessary to cancel the FM drive of the front wheels 4, knowing that the front wheels 4 will wear out. I have no choice but to perform a medium-immersion drive operation.

The present invention has been made as a result of various studies focusing on the above-mentioned circumstances, and is a control mechanism that allows the MJ speed of the front wheels to be adjusted to the IAI according to changes in the circumferential speed of the rear wheels.
This is what we are trying to offer.

The present invention is a f'lil 1iii rotational speed control sub-mechanism in an agricultural four-wheel drive tractor, which has a rear 1i drive + 11111 and a front N1
11fl'J, j4 A speed change transmission mechanism is provided at least 2 times between the moving i-axis, and the rotational speed of the front wheel is adjusted according to the change in the circumferential speed of the rear wheel, and the circumferential speed of the front and rear wheels is adjusted. The gist lies in the fact that it is structured so that it can be done equally.

The following is a detailed description of the configuration and operation and effects of the present invention based on the first aspect.
It is within the technical scope of the present invention to change the design, etc. of the speed change transmission mechanism in accordance with the spirit described below.

Figure 4 shows a front wheel drive transmission system equipped with related transmission #11 (hereinafter referred to as transmission) according to the present invention.
In the diagram of St. Transmission 9, rear wheel drive shaft 7 and 1
It is provided between the eleven wheel drive shafts 8. The rotation of the rear wheel drive shaft 7 is transmitted from the gear 19 to the gear 20, and the transmitted rotational force is transmitted from either the high speed gear 10 or the low speed gear 11 attached to the subshaft 21 to the gear 12 or the gear 18. The signal is transmitted to rotate the front wheel drive shaft 8. And these speed gears
Selection of whether to engage the gear 12 or the low speed gear 11 is made by adjusting the position of the clutch 28 provided between the gears 12 and 18, and the grain surface of the crack 2B is adjusted by operating the shift lever 17. For example, when changing the rotation speed of the front wheels 4 to high speed, the driver lever 17 is tilted in the direction of arrow (A), the clutch 23 is shifted to gear 12, and
The gear 12 is engaged with the clutch 28, and 100 rotations of the high speed gear are transmitted to the 111T wheel drive shaft 8. At this time, the gear 18 is not engaged with the clutch 23, so even if the low speed gear 11 and the hard platform rA-1pItC are present, the rotation of the low speed gear 11 is not transmitted to the front wheel drive shaft 8, and vice versa. front wheel 4
When changing the rotation speed to low speed, tilt the shift lever 17 in the direction of arrow c) to shift the gear 12 by the clutch 23.
23, and shift the gear 1a on the opposite side to the clutch 23.
110 rotations of the low speed gear are transmitted from the gear 18 to the front wheel drive shaft 8. At this time, the gear 12 is disengaged from the clutch 23, so it is in an idle state and no high-speed rotation transmission is performed.

Therefore, when driving the tractor 8 in four-wheel drive in a steady state, drive the shift lever 17 in the direction (A).
The rotation of the rear wheel drive shaft 7 is changed from the high speed gear 10 to the ii7 transport control 1.
The shaft Bvc is transmitted, and the circumferential speeds of the rear wheels 5 and m7 and 4 are made equal. In this state, the circumferential speed of the rear wheel 5 becomes slow (
For example, move the shift lever 17 with the arrow C
口) direction and lower the rotational opening degree of MiT嬶4,
The circumferential speed of the tl14fiii4 is adjusted to the circumferential speed of the rear wheel.As a result, the front wheel 4 does not slip, so it is possible to prevent wear on the front wheel as much as possible, and to maintain stable 4-wheel drive operation. Therefore, the traction force of the tractor 3 does not decrease.

FIG. 5 shows an embodiment of a transmission 9 applied to the present invention, which is of a continuous transmission type. The nine-piece transmission has a spline shaft 14 that is integrally connected to the front wheel drive shaft 8, and a subshaft 21 that transmits the rotation of the front wheel drive shaft 7, and the spline shaft 14 has a coupling 22.22. Spline gears 12 and 13 are provided loosely disposed through the spline gears 12 and 13.
．． Clutches 151) and 161) are provided at 1H. And inside the clutches 15b and 16b, there are slide clutches 15rt and 15l which are rotated by the shift lever 17.
6 a is installed, slide clutch IF+a, 1
6a has a spline hole (not shown) formed inside thereof so that it can rotate integrally with the spline shaft 14. 18
To transmit the movement of the shift lever 170 with the shift arm to the slide clutch 1fia, 16a [3, therefore, to transmit 100 revolutions of the high speed gear to the front wheel drive shaft 8, move the shift lever 17 in the direction of arrow (A). Engage Squid clutch 16a and clutch 16b. When the clutch is engaged in this way, the rotation of the spline gear 12 engaged with the high-speed gear is caused by the slide clutch 16a.
transmitted to.

High side rotation of the front wheel drive shaft 8 is obtained. On the other hand, if the IT+ wheel drive shaft 8 is to be rotated at a low speed, the shift lever 17 may be moved in the direction of arrow C to engage the slide clutch 15a with the clutch 15.b.

In the Tl-1 embodiment, the transmission 9 which can switch between high speed and low speed is shown in 111, but since the rear wheel circumferential speed may change continuously and over a wide range,
For example, by replacing the transmission with a multi-speed transmission or a torque converter type transmission,
The configuration may be such that the circumferential speed of the '4i+ wheel can be adjusted over a wide range vc-.

Since the present invention is configured as described above, it is possible to obtain the following effects similar to those achieved by the VC system.

Since the circumferential speed of i11100 can be matched to the circumferential speed of the rear wheels, tire wear due to differences in circumferential speed can be prevented as much as possible.

(2) Since the circumferential speeds of the front and rear wheels can be maintained equally, stable four-wheel drive operation is possible under any conditions.

(3) Traction force will not decrease.

[Brief explanation of the drawing]

1.2.8 is an explanatory diagram showing the four running parts of the tractor, and Figure 4 shows the front wheel rotation speed of the present invention! FIG. 5 is a suppression diagram illustrating the l-rinse mission applicable to the present invention. 1... Agricultural equipment 2... Cart 8... Tractor 4... Front wheel 5... Rear wheel 6.
...Connection part 7...Rear wheel drive shaft 8...Front wheel drive shaft 9...Transmission IO...High speed gear 11...Low speed gear 12.
18...Spline gear 14...Spline 1lflB 17...Shift lever - Applicant Kubota Iron Works Co., Ltd.

Claims (1)

[Claims] A front rotational speed control mechanism in a 1+l agricultural four-wheel drive twerkter, characterized in that at least a two-stage speed change transmission mechanism is provided between a rear wheel drive shaft and a front wheel drive shaft. Tractor 111 quad rotation speed control MMl
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