JPH02117425A - Four-wheel drive vehicle for agriculture - Google Patents

Abstract

PURPOSE:To permit single braking and turning without ruining the soil by installing two differential gears to distribute the rotational power from an engine to a driving wheel in the diagonal direction and providing an independent operatable brake respectively on right and left rear wheels. CONSTITUTION:On right and left rear wheels 16, 18 in a speed sprayer 10 are provided right and left brakes 20, 22 operatable independent of respective brake pedals 24, 26. The rotational power from an engine 38 is transmitted to a distributor 42 through a manual speed change gear 40 and is distributed from the first and second output shafts 44, 46 to the first and second differential gears 48, 50, and engine power is distributed to a left front wheel 12 and a right rear wheel 18 for output by the first differential gear 48, and is distributed to a right front wheel 14 and a left rear wheel 16 for output by the second differential gear 50. Moreover, the internal brake in the turning direction is controlled so as to operate when the steering angle of a steering wheel 28 detected by a steering angle detector 32 exceeds a given angle range.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to agricultural four-wheel drive vehicles such as speed sprayers, and more specifically, to matching the rotation speeds of the front and rear wheels when turning with one brake. This relates to agricultural four-wheel drive vehicles that can be used for agricultural purposes.

[Conventional technology]

In agricultural four-wheel drive vehicles such as speed sprayers, one-sided brakes are used to brake only the inner rear wheel in the turning direction when turning in order to reduce the turning radius as much as possible.

In this case, there is a differential gear between the left and right rear wheels, so when turning with one brake, the rotation speed of the rear wheel that is not applying the brake will be the same as the rotation speed of the rear wheel that is applying the brake. The number of wheels is doubled, and the overall rotational speed distribution between the front and rear wheels becomes unreasonable, and the rear wheel that is braked on one side is dragged, causing dirt to be shoveled, dug, or piled up. This causes damage to the farmland and increases the turning radius.

In designated agricultural four-wheel drive vehicles, single brakes are not used, but when the steering angle exceeds a designated range, the speed reduction ratio in the transmission is switched to make the front wheels rotate twice as much as the rear wheels. The difference in rotational speed between the two has been optimized.

[Problem to be solved by the invention]

Increasing the rotation speed of the front wheels to twice the rotation speed of the rear wheels using a transmission requires a complicated control device.

An object of claim 1 is to provide an agricultural four-wheel drive vehicle that can optimize the difference in rotational speed between front wheels and rear wheels without requiring switching by a transmission.

In addition to the object of claim 1, the object of the invention of claim 2 is to eliminate the troublesomeness of brake selection when turning by using one brake.

Note that Japanese Patent Application Laid-open No. 62-198521 discloses that in a four-wheel drive vehicle including a passenger car, rotational power from an engine is distributed to drive shafts in a diagonal direction. but,
In this four-wheel drive vehicle, one-sided braking is not only not used, but there is no intention to use it at all, and it does not form the basis of a technology to eliminate the negative effects caused by one-sided braking.

[Means to solve the problem]

The invention will be described using reference numerals in the drawings that correspond to the embodiments.

The agricultural four-wheel drive vehicle (lO) according to claim 1 comprises an engine (3
8), a first differential gear (48) that distributes and outputs rotational power from the engine (38) to the left front wheel (12) and the right rear wheel (18), and the engine (38).
8) is transferred to the right front wheel (14) and the left rear wheel (
16), the left brake (20) that brakes the left rear l1IQ (16), and this left brake (20) can be operated independently and the right rear @ (18) and a right side brake (22) for braking.

The agricultural four-wheel drive vehicle (10) of claim 2 includes a steering angle detector (3) that detects the steering angle of the steering wheel (28).
2), and when the detection signal of this steering angle detector (32) is input and the steering angle of the steering wheel (28) exceeds a predetermined range, the left brake (20) or the right brake (22) on the inside in the turning direction is activated. Brake operation part (36)
It has the following.

[Effect]

For example, when turning to the left with one brake.

The left rear wheel (16) on the inside in the turning direction is connected to the left brake (2).
0), the brake is braked and the robot is in a locked state. The rotational power from the engine (38) is transmitted to the first differential gear (48) and the second differential gear (50).
) to the left front wheel (12) and the right rear wheel (18),
and the right front wheel (14) and the left rear wheel (16), so the right front wheel (14) serves as the drive shaft on the outside in the turning direction.
The vehicle runs at approximately twice the rotation speed when traveling straight. In addition, the ground resistance and the first differential gear (
48), the rotational power is distributed to the right rear wheel (18).
The rotation speed of the left rear wheel (16) is higher than that of the left rear wheel (16), and the rotation speed of the left front wheel (12) is higher than the right rear wheel (18) and smaller than the right front wheel (14). .

In the invention of claim 2, when the agricultural four-wheel drive vehicle (10) is to turn with a small turning radius, the amount of operation of the steering wheel (28) increases and the steering angle exceeds a predetermined range. A steering angle detector (32) detects whether or not the steering angle exceeds a predetermined range. When it is detected that the steering angle exceeds a predetermined range, the brake operating section (36) operates to move the brake operating section (36) toward the inner side in the turning direction. Left brake (20) or right brake (
22), the agricultural four-wheel drive vehicle (10) becomes in one-brake mode.

〔Example〕

Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.

Figure 1 shows a speed sprayer equipped with a one-sided brake mechanism.
FIG. 2 is a configuration diagram of a drive system of O. The speed sprayer 10 has a left front wheel 12. Right front wheel 14, left rear wheel 1616 and right rear wheel 18
The left brake 20 and the right brake 22 brake the left rear wheel 16 and the right rear wheel 18, respectively.
and the right brake pedal 26 independently. The steering wheel 28 is connected to the right front wheel 12 which also serves as a steering shaft.
The steering angle detector 32 is connected to the right front transport 14 via a steering link 30.

The steering angle of the steering wheel 28 is detected from the amount of displacement of a predetermined portion of the steering link 30. The relay 34 receives a detection signal from the steering angle detector 32, and when the steering angle detector 32 detects that the steering angle of the steering wheel 28 to the left or right exceeds a predetermined value, the steering angle changes to the predetermined value. An output indicating that the rotation direction has been exceeded and the direction of rotation is sent to the actuator 36. The actuator 36 selectively operates the left brake 20 and the right brake 22 using hydraulic pressure, pressurized air, or the like.

The rotational power of the engine 38 is sent to a distributor 42 via a manual transmission 40 manually operated by an operator in the driver's seat.
The power is distributed from the first output shaft 44 and the second output shaft 46 of the distributor 42 to the first differential gear 48 and the second differential gear 50 . First differential gear 48 and second differential gear 5
0 are provided in line with the left front wheel 12 side and the right front wheel 14 side, respectively, with respect to the front-rear direction of the speed sprayer 10, and have an output shaft 52 and an output shaft 54 extending left and right. In the first differential gear 48, the left output shaft 52 also serves as the axle for the left front wheel 12, and the right output shaft 54 is connected to the front end of the propeller shaft 56. Further, in the second differential gear 50, the left output shaft 54 is connected to the front end of the propeller shaft 58, and the right output shaft 52 also serves as an axle for the right front wheel 14. The propeller shafts 56,58 extend diagonally, cross each other, and are connected at their rear ends to an axle 62 of the right rear wheel 18 and an axle 60 of the left rear wheel 16, respectively.

FIG. 2 is a structural diagram of the first differential gear 48. The structure of the first differential gear 48 is well known per se, and the structure of the second differential gear 50 is similar to that of the first differential gear 48.
Since it has the same structure as 8, the explanation will be omitted. The drive gear 64 is made of a bevel gear, is fixed to the front end of the first output shaft 44, and meshes with a ring gear 68 of the bevel gear. The pinion shaft 70 is rotatably supported by the differential case 66 in a direction perpendicular to the extending direction of the output shaft 52, 54, and the differential pinion 72 is fixed thereto.

Side gears 74 , 74 are respectively fixed to the ends of output shafts 52 , 54 and mesh with differential pinion 72 . The rotation of the first output shaft 44 causes the differential case 66 to rotate,
The differential pinion 7z rotates in relation to the ratio of the rotational resistances of the output shafts 52, 54, and thus the output shafts 52, 54 have a rotational speed that is inversely proportional to the ratio of their rotational resistances.

The operation of the embodiment will be explained.

When operating one-side brake manually, actuator 3
6 is in a state where the operation is stopped or the operation is disabled.

For example, when turning to the left with one brake, the operator depresses the left play 20 and turns the left rear @ 15 on the inside of the turning direction.
is braked by the left brake pedal 24, resulting in a lock state. The rotational power from the engine 38 is transmitted through a manual transmission 40 and a distributor 42 from a first output shaft 44 and a second output shaft 46 of the distributor 42 to a first differential gear 48 and a second differential gear 50. communicated. And the first differential gear 48
and the second differential gear 50, the left front @
12 and the right rear wheel 18, and between the right front wheel 14 and the left rear wheel 16, the right front wheel 14, which serves as the front drive shaft on the outside in the turning direction, rotates at approximately twice the rotation speed when traveling straight. Run in numbers. In addition, due to the ground resistance and the rotational power distribution by the first differential gear 48, the right rear wheel J8
The rotation speed of the left rear wheel 16 is higher than that of the right front wheel 12.
The number of rotations is greater than the number of rotations of the right rear wheel 11918 and smaller than the number of rotations of the right front wheel 14.

When automatically operating one-side brake, actuator 36
is considered to be in an active state. When attempting to turn the speed sprayer IO with a small turning radius, the amount of operation of the steering wheel 28 increases and the steering angle exceeds a predetermined range. The steering angle detector 32 detects the steering angle, and when the steering angle exceeds a predetermined range, a signal indicating that the steering angle exceeds the predetermined value and the turning direction is sent from the relay 34 to the actuator 36.
sent to.

In this way, the actuator 36 operates the left brake 20 or the right brake 22 on the inner side in the turning direction, and the speed sprayer IO becomes in a one-brake state.

The rotation speeds of the left front wheel 12, right front wheel 14, left rear wheel 16, and right rear wheel 18 are set to those suitable for turning with one brake, as in the case of manual operation of one brake. It is automatically controlled by differential gear 50 of No. 2.

〔Effect of the invention〕

In the invention of claim 1, the two differential gears are connected so as to distribute the rotational power from the engine to the drive shafts in the diagonal direction. The front wheels can be rotated at approximately twice the rotation speed when not turning, making it possible to optimize the overall rotation speed difference between the drive wheels in agricultural four-wheel drive vehicles. suppressing vandalism,
Moreover, the turning radius can be appropriately reduced.

In the invention according to claim 2, the steering angle of the steering wheel is detected by the steering angle detector, and when it is desired to obtain a small turning radius by using one side brake.

The brake operating section automatically puts the driving rear wheel on the inside in the turning direction into a braking state. This eliminates the need for the operator to select the inner brake in the turning direction, making operation easier and easier.
and accurate.

[Brief explanation of drawings]

The drawings relate to embodiments of the present invention, and FIG. 1 is a configuration diagram of a drive system of a speed sprayer equipped with a one-sided brake mechanism, and FIG.
The figure is a structural diagram of the first differential gear. 10...Speed sprayer (agricultural four-wheel drive vehicle),
12...Left front wheel, 14...Right front wheel, 16...Left rear wheel, 18...Right rear wheel, 20...Left side brake, 22
...Right side brake, 28...Steering wheel, 32...Steering angle detector, 36...Actuator (brake operating section), 38...Engine, 48...
1st differential gear, 50... 2nd differential gear. Figure 1 Figure 2 14: Right front wheel 16: Left rear wheel 18: Right rear wheel 20: Left brake procedure correction band (voluntary) November 24, 1985 Commissioner of the Japan Patent Office Kim 1) Moon Yi 1, of the incident Indication 1988 Patent Application No. 269528 2 Name of the invention Agricultural four-wheel drive vehicle 3 Relationship with the case of the person making the amendment Name of the patent applicant Name Maruyama Seisakusho Co., Ltd. 4 Details of the invention in the agent's specification Contents of the amendment in the explanation column (as shown in the attached sheet) (6. Contents of the amendment) In the specification, "is multiplied by...2" in line 16 of page 2 is amended as follows. 2) Correct ``Toko'' in line 12 of page 5 as follows [as''] 3) Correct ``Rano no 1'' in line 6 of page 9 as follows. 4) Correct [left play 20] in line 11 of the same page as follows [left brake pedal 24] 5) Correct 'left brake pedal 24' in line 12 of the same page as follows r left Brake 20"

Claims (2)

[Claims] (1) An engine (38) and a first differential gear (48) that distributes and outputs rotational power from the engine (38) to the left front wheel (12) and the right rear wheel (18).
), and a second engine that distributes and outputs the rotational power from the engine (38) to the right front wheel (14) and the left rear wheel (16).
differential gear (50), and the left rear wheel (
The left brake (20) brakes the right rear wheel (16), and this left brake (20) can be operated independently and brakes the right rear wheel (16).
8) A right-side brake (22) for braking the vehicle. (2) A steering angle detector (32) that detects the steering angle of the steering wheel (28); and this steering angle detector (32).
A detection signal is input to the steering wheel (28
according to claim 1, further comprising a brake operating section (36) that operates the left brake (20) or the right brake (22) on the inner side in the turning direction when the steering angle of the vehicle exceeds a predetermined range. Agricultural four-wheel drive vehicle.