JPS61184127A - Device for driving steered wheels of vehicle - Google Patents

Abstract

PURPOSE:To remarkably reduce the minimum turning radius of a vehicle, by associating and coupling the output shafts of a differential gear with the power input shafts of a steered wheel side, and by offsetting the axis of the output shafts of the differential gear from the axis of the the input shafts of the steered wheel side. CONSTITUTION:The output shafts 8, 13 of a differential gear are projected from the left side of a mission casing 5 and the right side of a front wheel differential gear casing 11, respectively. In this arrangement these output shafts 8, 13 are coupled through universal coupling 27, 28 with connecting shafts 31, 32 which are in turn coupled with the input shafts 25, 22 of a reduction gear through universal coupling 33, 34. Further, the axis F1 of the axle 12 for front wheels is offset from the axis F0 of the output shaft 13 by a predetermined distance rearward of a vehicle body as seen in the lateral view, and the axis R1 of the axle 26 for rear wheels 16 is offset from the axis R0 of the output shaft 8 forward of the vehicle body by a predetermined distance as seen in the lateral view. With this arrangement the connecting shaft 32 for driving the front wheels and the connecting shaft 31 for driving the rear wheels are inclined at angles of alpha, theta, respectively as seen in the plan view.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a driving device for steering wheels in a vehicle.

(Prior art) It is well known in FF vehicles that the driving force is transmitted to the steering wheels provided on the left and right sides of the vehicle via a differential. The axis of the input shaft (generally an axle) was aligned with the longitudinal position of the vehicle body.

(Problem to be Solved by the Invention) Incidentally, in order to improve the turning performance of a vehicle, the minimum turning radius is reduced, but conventional steering wheels, regardless of whether they also serve as driving wheels, cannot There was a limit to minimizing the radius.

Therefore, an object of the present invention is to focus on the steering wheels that also serve as driving wheels, and by devising the power transmission structure from the differential output shaft, it is possible to significantly reduce the minimum turning radius, thereby improving turning performance. An object of the present invention is to provide a steering wheel drive device for a vehicle that is improved.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a differential output shaft (8), (
13), the steering wheel (15), and the power input shaft (1B)
22), (25) and universal joints (27), (28), (
33), (34), and are interlocked with the connecting shafts (31), (32), and the differential output shafts (8), (13), (7) shaft centers (Fo), (Ro) and the steering wheels ( 15).

(16) side power input shaft (22), (25) axis center (F
+) and (R+) are offset in the longitudinal direction of the vehicle body.

(Example) Examples will be described in detail below based on the accompanying drawings.

Fig. ff11 is a cutaway side view of the vehicle, and Fig. 2 is a plan view of the drive system. In the embodiment, a riding work machine will be described.

A crankshaft (4) and a vertical engine (3) are mounted on the front of the frame (2) of the riding work machine (1).
) A mission case (5) is installed in the part, and the mission input shaft (8) and crankshaft (0 is the propulsion shaft (9)
), and the transmission output shaft (7) and the input shaft (12) of the front wheel differential case (11) at the front of the frame (2).
) are connected by a propulsion shaft (14), and the frame (2) front and rear left and right front wheels (15), (15) and rear wheels (le).

(1B) are reduction cases (21) and (2), respectively.
1).

(24), (24) output shaft (23), (23), (
2B) and (2B). Therefore, the reduction output shafts (23), (23).

(26) and (2B) also serve as axles.

A rear wheel differential (not shown) is provided in the lower part of the mission case (5), and differential output shafts (8) (8) protrude from the mission case (5) to the left and right, and a front wheel differential case (11) is provided. Differential output shafts (13) (13) protrude from the left and right sides. These are the differential output shafts (8), (8).

(13), (13) with universal joint (27), (27)
, (28), (28) to the connecting shafts (31), (31
), (32), (32), and further connect the connecting shaft (31)
, (31), (32), universal joint (33) in (32),
(33).

(34), reduction input shaft (25) via (34)
, (25).

(22) and (22) are connected.

As shown in MS Figures 3 and 4, the front and rear glue reduction cases (21) and (24) are respectively knuckles (35).

(36), Kingpin (3?), (3?), (38
), (38), and is supported in a freely steerable manner.
35) and (3B) are fixedly supported by holders (41) and (42) fixedly installed on the frame (2) side so that the vehicle height can be adjusted,
Also knuckle (35), (3B) upper part and holder (41)
, (42) There are upper arms (43) and (44) between the bases.
will be erected.

Furthermore, tie rods (47) are connected to the reduction cases (21) and (24) via brackets (45) and (4B).
(48) is connected to the steering gear box (51).
) The link mechanism (52) extending in the front and rear direction connects the front, rear, left and right tie rods (47), (47), (48), (4
8) are interlocked and connected, so that the front wheels (+5), (+5) and the rear wheels (1B), (1
B) is steered in opposite left and right directions. Here, the connecting shaft (31
), (32) Tori induction input shaft (25), (22
) and a universal joint (33).

The center of (34) coincides with the center line of kingpin (311) and (3?).

As shown in Fig. 1 and Fig. 2, the front wheel (15) is
.

The axle (23) of (15), the axle center (Fo of (23) of (8
) Offset the axles (R1) of the rear wheels (2111) and (2B) to the front of the vehicle by a distance (B) in side view (plan view) with respect to the axis (Ra) of and place it. Here, reduction input shafts (22), (25) are located directly above the front and rear axles (23), (2B). Also, when traveling straight, that is, when the steering is in a neutral state, the axis center (F
o), (F+), (Ro), and (R+) are arranged and set so that they are parallel in plan view.

In this way, the front wheel drive connecting shaft (32) is set at an angle (α
), and the rear wheel drive connecting shaft (31) is tilted by an angle (θ).

In the above, in order to make a smooth turn, the steering system is configured such that the left and right front wheels (15), (15) on the inside of the turn move at an angle (β) in the turning direction, and those on the outside of the turn turn at an angle (γ). ), the left and right rear wheels (1B), (1B) on the inside of the turn are turned at an angle (η) in the opposite direction of the turn, and those on the outside of the turn are turned at an angle (6
) is the maximum steering angle. However, the relationship is β>γ, η>ε.

Note that any suitable steering device may be used as long as it satisfies the above requirements.

Next, the angles (α) and (0) are set as follows.

First, when steering, the connecting shafts (32), (31) and the axle (
23), (2B) universal joint between (34), (33)
) is bent, but there is a limit to this bending angle, and the wheels (15), (1B
) cannot have a large maximum steering angle (β), (η).

That is, there is a relationship of C≧β and C≧η.

Therefore, C>(β+γ)/2. The relationship C>(η+ε)/2 is maintained.

As a result, the inclination angle of the left and right connecting shafts for the front and rear wheels is determined from the geometrical conditions: α is approximately the difference between β and γ, and θ is approximately the difference between η and ε.
An approximation of the difference between α and (β−γ)/2 and 0 and (η−ε)/2 is derived.

As a result of the above, the bending limit angle (
It is possible to obtain a substantial maximum steering angle of the wheels (15) and (I8) that exceeds C). This will be explained below based on FIG.

:5S5 figure shows the maximum steering condition for the front wheels (15), (15), and the center of axis (Fo) is shown by the broken line.
.

When (F+) are made to coincide with each other in plan view, the turning center (00) for the front wheels is far apart to the side of the vehicle body as shown in the figure.

On the other hand, as shown by the solid line, the axis center (Fo), (F+)
When viewed from above and offset as in the embodiment, the turning center (0 blind) for the front wheels will be located immediately near the wheel on the inside of the turning as shown in the figure.

Therefore, the minimum turning radius can be reduced by a factor of 10.

Furthermore, since the rear wheels (1B) and (1B) function in the same way, just with opposite steering directions, if the power transmission shaft arrangement of the front and rear wheel drive devices is configured as in the example, the turning of the vehicle will be improved. This results in a significant improvement in performance, which is particularly beneficial for agricultural riding implements (1).

In the embodiment, the present invention was applied to a riding work machine, and the process was applied to both the front and rear wheels, but it goes without saying that the present invention may also be applied to a general vehicle, an F vehicle, or an F vehicle. Further, the axle of the steering wheel may be connected to the connecting shaft via a universal joint without disposing a reduction device on the wheel side.

(Effects of the Invention) As described above, according to the present invention, the differential output shaft and the power input shaft on the steering wheel side are interlocked and connected by the connecting shaft via the universal joint,
In addition, because the axis of the differential output shaft and the axis of the power input shaft on the steering wheel side are offset in the longitudinal direction of the vehicle body, the minimum turning radius can be significantly reduced, further improving turning performance. can.

[Brief explanation of drawings]

Figure 1 is a cutaway side view of the vehicle, Figure 2 is a plan view of the drive system,
FIG. 3 is a front view of the front wheel support section, FIG. 4 is a rear view of the rear wheel support section, and FIG. 5 is a diagram showing the maximum steering state of the wheels. In addition, (8) and (13) in the drawing are the differential output shaft, (15),
(1B) is a steering wheel, (22) and (2!5) are power input shafts, and (23). (26) is the axle, (27), (28), (33),
(34) is a universal joint, and (31) and (32) are connection shafts.

Claims (1)

[Claims] In a vehicle that transmits driving force to the left and right steering wheels via a differential, the differential output shaft and the power input shaft on the steering wheel side are interlocked by a connecting shaft via a universal joint, and the differential output shaft is A steering wheel drive device for a vehicle, characterized in that the shaft center and the shaft center of a power input shaft on the steering wheel side are arranged offset in the longitudinal direction of the vehicle body.