JPH0790703B2 - Front-and-rear-wheel drive vehicle that can change front wheel speed and cutting angle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a front and rear wheel drive vehicle capable of changing the speed and cutting angle of front wheels.

(Prior Art) There is a vehicle in which turning performance is improved by increasing the front wheel speed when the front wheels are steered in the front-rear wheel driving state (see Japanese Utility Model Application No. 61-185794). Such acceleration of the front wheels is convenient when the work machine is connected to the vehicle to perform work. However, in the case where normal road surface traveling is performed, it is dangerous to make a sharp turn during high speed traveling, and therefore the mode can be freely switched between a state in which the front wheels are accelerated and a state in which they are not accelerated.

Further, in order to prevent the steering angle of the front wheels from becoming too large, there is a vehicle in which the maximum steering angle of the front wheels is regulated within a certain range by a regulation body. In this type of conventional vehicle, the maximum steering angle of the front wheels is regulated to prevent sharp turns at high speeds, to prevent soil from being scraped due to wheel slips in ground-based work vehicles such as agricultural tractors, and to equip front wheels with vehicle body equipment. This is to prevent interference with for that reason,
When changing the front wheel tread, there is no interference with the body equipment, so there are vehicles where the maximum steering angle can be changed by changing the position of the steering angle restriction body. (See Japanese Patent Application No. 61-185794).

(Problems to be Solved by the Invention) When the front wheels are steered in the front-rear wheel driving state, it is usually a low-speed working state that the front wheels are accelerated to make a turn, and the front wheels are not accelerated. Since the turning performance is improved compared to the case where there is no such problem, there are few problems such as soil cutting due to wheel slip. In addition, the problem of interference between front wheels and body equipment, even if you do not regulate the maximum steering angle
This is a problem that can be dealt with by changing the design such as the layout of body equipment.

That is, conventionally, although the turning performance is improved by increasing the speed of the front wheels during steering, the maximum steering turning angle is regulated, and thus the turning radius can be sufficiently reduced. However, the present invention solves such a problem.

(Means for Solving the Problem) A feature of the present invention is that a front wheel speed-increasing mode operating member 27 for increasing / decreasing the front wheel speed when the front wheel is steered at a constant angle in the front-rear wheel drive state. In a vehicle having a restriction body 45 that restricts the maximum steering angle of the front wheels within a certain range, the restriction of the maximum steering angle of the front wheels by the restriction body 45 is changeable, and the operating body 27 is By changing over from the OFF state of the front wheel speed increasing mode to the ON state, the maximum steering control angle of the front wheels becomes larger than that in the OFF state of the front wheel speed increasing mode so that the restriction body 45 of the operating body 27 is changed. This is in connection with the switching operation.

Further, the restricting body 45 contacts the knuckle arm 41 to restrict the maximum steering angle of the front wheels within a certain range.
By changing the position of the regulation body 45, the regulation body 45
It is advisable that the maximum steering angle of the front wheels can be freely changed.

Further, the steering angle of the front wheels is to be changed in conjunction with the swing angle of the pitman arm 39 attached to the vehicle body side, and the regulation body 45 regulates the swing of the pitman arm 39. Therefore, the maximum steering angle of the front wheels may be restricted within a certain range.

(Operation) In the off state of the front wheel speed increasing mode, the front wheels are not accelerated even if the front wheels are steered, and the maximum steering turning angle of the front wheels is regulated by the regulation body 45 within a certain range. From this state,
When the operating body 27 is operated to enter the front wheel speed increasing mode,
When the front wheels are steered, the speed of the front wheels is increased, and the regulation body 45 is interlocked with the operation body 27 to change the regulation of the maximum steering angle of the front wheels by the regulation body 45 to change the maximum steering direction of the front wheels. The cutting angle becomes large. That is, the steered steering angle of the front wheels is increased corresponding to the improvement in turning performance.

Further, in the case where the regulation body 45 contacts the knuckle arm 41 to regulate the maximum steering angle of the front wheel within a certain range, the maximum steering angle of the front wheel by the regulation body 45 is changed by changing the position of the regulation body 45. Cutting angle regulations are changed.

In the case where the front wheels are steered via the swing of the pitman arm 39, the maximum steering angle is regulated by regulating the swing of the pitman arm 39 by the regulation body 45.

(Example) Hereinafter, the Example of this invention is described with reference to drawings.

FIG. 4 shows a traveling power transmission structure of an agricultural tractor shown as an example of a vehicle. That is, the output of the engine 1 is transmitted to the rear wheel drive shaft 4 via the clutch 2 and the gear transmission 3, and is transmitted from the rear wheel drive shaft 4 to the left and right rear wheels 6 via the rear wheel differential device 5. To be done. Further, the power is transmitted from the rear wheel drive shaft 4 to the first relay shaft 9 via the meshed gears 7 and 8, and the power is transmitted from the first relay shaft 9 to the second relay shaft 11 via the front wheel clutch 10. Can be communicated freely. And
Power is transmitted from the second relay shaft 11 to the front wheel drive shaft 13 via the front wheel transmission device 12, and is transmitted from the front wheel drive shaft 13 to the left and right front wheels 15 via the front wheel differential device 14.

The front wheel transmission 12 includes a gear 20 and a gear 21 having different numbers of teeth, which are mounted so as to rotate together with the second relay shaft 11.
A gear 22 that meshes with the gear 20 and a gear 23 that meshes with the gear 21 are provided, and the gear 22 and the gear 23 are relatively rotatably fitted to the front wheel drive shaft 13. Further, a shifter 24 mounted so as to rotate together with the front wheel drive shaft 13 is provided.
Is connected to the gear 22 via the clutch 25 so that the power can be connected and disconnected, and is also connected to the gear 23 via the clutch 26 so that the power can be connected and disconnected.

The front wheel clutch 10 and the clutches 25, 26 are interlocked with the swing lever type operating body 27, and the clutch 26 is interlocked with the steering of the front wheel 15. The operating body 27 is an agricultural tractor 2
Three positions: a position for making a four-wheel drive state, a position for making a four-wheel drive and a front wheel speed increasing mode being "off", and a position for making a four wheel drive and making a front wheel speed increasing mode "on". It is said to be switchable.

That is, when the operating body 27 is rocked to a position where the tractor is in the two-wheel drive state, the front wheel clutch 10 is in the “disengaged” state, and power is not transmitted to the front wheels 15.

When the operating body 27 is swung to a position where the tractor is driven by four wheels and the front wheel speed increasing mode is in the "off" state, the front wheel clutch 10 and the clutch 25 are "on" and the clutch 26 is "off". Therefore, power is transmitted to the front wheels 15 via the gears 20 and 22, and even if the front wheels 15 are steered, the front wheels 15 are not accelerated.

When the operating body 27 is swung to a position where the tractor is in the four-wheel drive state and the front wheel speed increasing mode is in the “ON” state, the front wheel is moved.
If the steering speed of 15 is within a certain range, the front wheel clutch 10 and the clutch
When 25 is “ON” and the clutch 26 is “OFF”, and when the steering angle of the front wheels 15 exceeds a certain value, the front wheel clutch 10 and the clutch 26 are “ON” and the clutch 25 is “OFF”. . That is, when the front wheels 15 are steered by a certain angle, the power to the front wheels 15 was transmitted through the gears 20 and 22, but the power is transmitted through the gears 21 and 23.
Is accelerated.

The interlocking mechanism between the operating body 27 and the front wheel clutch 10, the clutches 25 and 26, and the interlocking mechanism between the clutch 26 and the steering of the front wheels 15 are the same as those conventionally known.

Next, as shown in FIG. 1, the connection between the front wheels 15 and the vehicle body is as follows.
The front wheel bearing stand 30 that forms part of the vehicle body has a front wheel differential
A front axle case 31 having built-in components such as 14 is supported, and front wheel cases 32 are swingably connected to both ends of the front axle case 31 about a support shaft 33, and the front wheel case 32 is attached to the front wheels via an axle (not shown).
15 is installed.

For steering the front wheels 15, a steering gear box 37, which is linked to an unillustrated steering wheel, is attached to the front vehicle bearing stand 30, and a steering shaft 38 of the steering gear box 37 is attached to a steering shaft 38 of the pitman arm. 39 is attached, and the pitman arm 39 and the knuckle arm 41 formed in each front wheel case 32 are connected by a tie rod 40. As a result, the steering shaft 38 is rotated by the operation of the handle and the pitman arm 39 is swung, and this swing is transmitted to the front wheel 15 via the tie rod 40 and the knuckle arm 41, and the front wheel 15 is a support shaft.
33 Steering is performed by swinging around the center.

Then, in the front axle case 31, left and right restricting bodies 45 that restrict the maximum steering angle of each of the left and right front wheels 15 within a certain range,
It is supported via a support mechanism 46. That is, as shown in FIGS. 2 and 3, seats 47 are formed on the front surfaces of the left and right ends of the front axle case 31, respectively, and stoppers 48 are formed on the seats 47 and project toward the rear of the support bolt 50. It is fixed by. A projecting piece 49 projects forward from the stopper 48. Further, the support bolt 50 has a screw shaft projecting forward and backward, and a mounting piece 51 is rotatably supported on the front protruding portion thereof, and a triangular prism-shaped restricting body 45 is mounted on the mounting piece 51. In addition, the spring 5 is attached to the front protrusion of the support bolt 50.
2. The spring attachment piece 53 is inserted, and the nut 54 is screwed to prevent the spring attachment piece 53 from coming off. The spring 52 is engaged with the mounting piece 51 and the spring mounting piece 53, and the elastic force of the spring 52 urges the regulating body 45 to rotate in the direction of arrow A in FIG. The rotation of the regulation body 45 is caused by the stopper.
It is regulated by coming into contact with the protruding piece 49 of 48, and the state shown in FIG. 2 is maintained. In this second illustrated state, the knuckle arm 41 comes into contact with the front end of the restricting body 45 to restrict the maximum steering angle of the front wheel 15.

The restriction body 45 and the operating body 27 are interlocked with each other. That is, one end of the inner wire of the push-pull wire 55 is connected to each mounting piece 51, and one end of the outer wire of each push-pull wire 55 is supported by the outer receiver 56 formed in the front axle case 31. Further, the other end of the outer wire of each push-pull wire 55 is supported by an outer holder 57 formed on the vehicle body side, and the other end of each inner wire is connected to a connecting wire 58,
The connecting wire 58 is connected to the operating body 27. As a result, the operating body 27 is rocked and the front wheel speed increasing mode is set to “ON”.
In this state, the push-pull wire 55
51 is pulled and swings, the regulation body 45 swings in the direction opposite to the arrow A direction in FIG. 2, the regulation body 45 moves to a position where it does not contact the knuckle arm 41, and the maximum steering change of the front wheel 15 occurs. The angle increases. Further, when the front wheel speed increasing mode is set to the "OFF" state, the restricting body 45 swings in the direction of the arrow A, and the restricting body 45 comes to the contact position with the knuckle arm 41.

For example, when the regulation body 45 contacts the knuckle arm 41, the maximum steering angle of the front wheel 15 is 53 to 54 degrees on the inner wheel side, 47 to 48 degrees on the outer wheel side, and the regulation body 45 contacts the knuckle arm 41. The maximum steering angle of the front wheel 15 when not in contact is regulated by the abutment of the knuckle arm 41 and the front axle case 31, and the maximum steering angle on the inner wheel side
70 degrees and 55 degrees on the outer ring side.

In addition, the restriction body 45 is provided with a portion having a different amount of forward projection,
When the front wheel speed increasing mode is "OFF", a large portion of the front wheel speed increasing mode abuts on the knuckle arm 41, and when "ON", a small portion of the front wheel speed increasing mode abuts on the knuckle arm 41 so that the maximum steering angle may be increased. .

Further, as shown in FIG. 5, the knuckle arm 41 has a recess 63.
And in the "OFF" state of the front wheel speed increasing mode, the recess
The maximum steering angle of the front wheels 15 is regulated by fitting the 63 and the tips of the triangular prism-shaped regulation bodies 45 in a concavo-convex manner, and when the regulation bodies 45 swing in the "ON" state of the front wheel speed increasing mode, the sixth As shown in the figure, the knuckle arm 41 and the front inclined surface of the regulation body 45 may be brought into contact with each other. As a result, the movement amount of the regulation body 45 when the front wheel speed increasing mode is set to “ON” is
Even if the movement linked to the operation amount of is not enough,
When the steering angle of 15 becomes large, the knuckle arm 41 becomes a restriction body.
By pushing 45 through the inclined surface, the regulation body 45 moves,
It is possible to sufficiently increase the maximum steering angle of the front wheel 15. That is, the entire inclined surface of the restricting body 45 is the cam surface 64.

It should be noted that the contact with the restricting body 45 is not limited to the knuckle arm 41, but it may be in contact with a bracket formed separately from the front wheel 15 side.

Further, since the regulation body 45 only needs to regulate the steering angle of the front wheel 15, the maximum steering angle of the front wheel 15 can be controlled by regulating the swing of the pitman arm 39 as shown in FIGS. 7 and 8. May be regulated.

That is, the front wheel bearing base 30 has a frame-like shape, and the restriction members 45 are attached to the brackets 59 provided on the left and right side frame portions, respectively.
Is swingably supported about a support shaft 60 at the center of the left and right shafts, and is connected to the operating body 27 via the push-pull wire 55 as described above. When the operating body 27 is in the front wheel speed increasing mode “OFF”, the restricting body 45 is positioned on the left and right sides of the pitman arm 39 as shown in FIG. 8 and restricts the swing range of the pitman arm 39. When 27 is in the front wheel speed-increasing mode "ON", the restricting body 45 is swung in the direction of arrow B in the figure and is positioned above the pitman arm 39 so as not to restrict the swing range of the pitman arm 39. Increase the maximum steering angle of the front wheel 15.

Note that the interlocking between the restricting body 45 and the operating body 27 is not limited to mechanical one, and an electric motor may be operated by operating the operating body 27, and the restricting body 45 may be operated by the motor.

(Effect of the Invention) According to the present invention, when the front wheels are accelerated during steering, the maximum steering angle of the front wheels is increased, and the turning radius can be sufficiently reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a main part of a vehicle according to an embodiment of the present invention, FIG. 2 is a partial front view of the same, and FIG. 3 is a partial perspective view of the same.
FIG. 4 is an explanatory view of the same power transmission structure, FIGS. 5 and 6 are explanatory views of the operation of another embodiment, and FIG. 7 is a plan view showing a main part structure of still another embodiment. FIG. 8 is a partial side view of the same. 27 …… Operator, 45 …… Regulator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisakatsu Yasumiya 64, Ishizukita-cho, Sakai City, Osaka Prefecture Kubota Iron Works Co., Ltd. Sakai Works (56) References JP 62-143735 (JP, A)

Claims (3)

[Claims] 1. A front wheel speed-increasing mode on / off operation member (27) in which the front wheel speed is increased when the front wheels are steered by a constant angle in a front-rear wheel drive state, and a maximum front steering angle is constant. In a vehicle provided with a restricting body (45) for restricting within, the restriction of the maximum steering angle of the front wheel by the restricting body (45) is changeable, and the operating body (27) is in the front wheel speed increasing mode. By changing over from the off state to the on state, the maximum steering angle of the front wheels is switched to the operation body (27) so that the maximum steering angle of the front wheels becomes larger than that in the off state of the front wheel speed increasing mode. A front-rear-wheel-drive vehicle capable of changing the speed and cutting angle of front wheels, characterized by being linked to an operation. 2. The restricting body (45) restricts the maximum steering angle of the front wheels within a certain range by contacting the knuckle arm (41) side, and the position of the restricting body (45) is changed. The front-rear-wheel drive vehicle capable of changing the speed and cutting angle of the front wheels according to claim 1, wherein the restriction of the maximum steering angle of the front wheels by the restricting body (45) is freely changeable. 3. The steering turning angle of the front wheels is changed in association with the swing angle of the pitman arm (39) attached to the vehicle body side, and the restricting body (45) is the pitman arm (39). 39) The maximum steering angle of the front wheels is regulated within a certain range by regulating the swing of (39).
A front-rear-wheel drive vehicle capable of changing the speed and turning angle of the front wheels described.