JPH0635080U - Drive wheel steering system - Google Patents

Abstract

(57) [Abstract] [Purpose] To easily realize a high waist configuration that is strong against rough terrain. [Structure] Rotational power from an axle shaft 60 is transmitted through a constant velocity joint 59, and
A driving wheel 53 that rotates around a wheel shaft 50 having a ground clearance lower than 0 is pivotally supported by a steering knuckle 54, and the steering knuckle 54 is provided by a king pin 55 having an axis that points substantially at the center of a constant velocity joint 59. A knuckle arm 57, which is pivotally supported by the axle end 56 and is loosely inserted into the axle end 56 and connected to the steering knuckle 54, receives steering force to change the direction of the drive wheels 53, thereby securing the ground clearance of the vehicle body. In addition, a waist height configuration that is strong against rough terrain is easily realized.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a drive wheel steering device in which an axle shaft that transmits power to a drive wheel can be arranged above a wheel center.

[0002]

[Prior art]

 Since a four-wheel drive vehicle transmits engine power to all front and rear wheels, the front wheels, which are steered wheels, must have a structure that allows direction control in a power transmission state. In the conventional steering system 1 for driving wheels shown in FIG. 2, a front axle hub 4 which is bolted and fixed to a wheel 3 on which a tire 2 is mounted rotates on a straight sleeve 7 via a pair of bearings 5 and 6. It is supported freely. The base end side of the straight sleeve 7 is fixed to a steering knuckle 8, and the steering knuckle 8 is rotatably supported by an axle housing 11 by upper and lower kingpins 9 and 10. A constant velocity joint 12 is arranged between the upper and lower kingpins 9 and 10 of the steering knuckle 8, and the rotational power of the axle shaft 13 is transmitted to the wheel shaft 14 via the constant velocity joint 12 and indirectly to the wheel shaft 14. The tire 2 rotates with the rotation of the front axle hub 4 that has been fixed firmly. A knuckle arm 15 that receives a steering force from a steering mechanism (not shown) is connected to the steering knuckle 8, and when the knuckle arm 15 swings, drive wheels 16 that are front wheels change directions. The axes of the axle shaft 13, the kingpins 9 and 10, and the wheel shaft 14 intersect at the center point of the constant velocity joint 12, and the wheel shaft 14 has the same ground clearance as the axle shaft 13.

[0003]

[Problems to be solved by the device]

 In the conventional steering apparatus 1 for front wheels described above, since the wheel shaft 14 and the axle shaft 13 are located at the same height position, even if the ground clearance of the vehicle body is reduced, the tire size, that is, the tire shaft from the center of the wheel shaft 14 is used. Since the distance to the outermost diameter part of 2 becomes the ground height of the axle shaft 13 or the chassis as it is, it is possible to suppress the vehicle height by installing the tire 2 with the smallest allowable diameter on the wheel 3. It was all I could. Further, since the constant velocity joint 12 is sandwiched from above and below by the pair of king pins 9 and 10, the peripheral structure of the constant velocity joint 12 becomes large, and the space for accommodating the wheel 3 is accordingly increased. As it was required, the diameter of the tire 2 that could be mounted on the wheel 3 had to be increased, making it difficult to reduce the ground clearance.

On the other hand, in order to suppress the vehicle height of a four-wheel drive vehicle in the same manner as a rear-wheel drive vehicle, the applicant of the present invention has proposed that in the previously filed Japanese Utility Model Publication No. 1-114372 “Drive Wheel Steering Device” As shown in FIG. 3, a steering knuckle 35 is pivotally supported by a king pin 23 on an axle end 22 attached to an end portion of an axle housing 21, and a pair of housings 25 in a housing 25 fixed to the steering knuckle 35. A drive wheel steering device 29 having a structure in which a front axle hub 28 is rotatably supported by bearings 26 and 27 has been proposed. The rotation of the axle shaft 30 in the axle housing 21 is transmitted to the reduction gear mechanism 33 in the wheel 32 via the constant velocity joint 31, and converted into rotation of the wheel shaft 34. The steering knuckle 35 is pivotally driven around the kingpin 23 by the steering force via the knuckle arm 24, and the direction of the drive wheels 36 is changed. The drive wheel steering device 29 need only be provided with one king pin 23 above the constant velocity joint 31, and moreover, the ground height of the axle shaft 30 is higher than the ground height of the wheel shaft 34 which is the rotation center of the drive wheel 36. Therefore, even if the tire 2 having the same diameter as that of the conventional steering device 1 is mounted, the vehicle height can be suppressed to be considerably low.

However, the conventional drive wheel steering device 29 described above is suitable for the purpose of suppressing the vehicle height and ensuring the traveling stability without any problem, but like a leisure vehicle with a strong off-road orientation, it can be used on uneven terrain. For vehicles that want to keep the ground height of the axle shaft 30 higher than that of general vehicles so that obstacles on the ground do not collide with the chassis during traveling, the axle shaft 30 that is the center of rotation of the drive wheels 36 may be more On the contrary, the fact that the ground clearance is lower is an obstacle, and even if the tire 2 with a large outer diameter is mounted, the ground clearance cannot be increased, and it is difficult to imagine running on the beach or in the wilderness. There were challenges.

In addition to the drive wheel steering device 29 described above, steering devices having a structure in which the wheel shaft is offset above the axle shaft are disclosed in, for example, Japanese Patent Laid-Open No. 63-20276 and Japanese Patent Publication No. 63-149268. No., etc. However, all of them have a structure in which the bevel gears arranged above and below the kingpin transmit the rotation of the axle shaft to the wheel shaft, and because the kingpin rotates itself, it is easy to make the kingpin support structure and complicated, which makes it difficult for heavy vehicles. There was a problem that it was difficult to secure strength.

The present invention has been made in view of these points, and a wheel knuckle of a drive wheel rotatably connected to an axle shaft by a joint is disposed at a steering knuckle lower than the axle shaft. The purpose is to easily realize a high waist configuration that is strong against rough terrain by supporting the vehicle.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a drive wheel that is rotated around a wheel shaft having a ground clearance lower than that of the axle shaft by transmitting rotational power from the axle shaft through a joint. A steering knuckle that pivotally supports, an axle end that pivotally supports the steering knuckle with a kingpin that has an axis that points substantially at the center of the joint, and the axle end is loosely inserted and connected to the steering knuckle to provide steering force. And a knuckle arm for changing the direction of the drive wheels.

[0009]

[Action]

 Based on the above configuration, the driving power that is transmitted from the axle shaft through the joint and that rotates around a wheel shaft whose ground clearance is lower than that of the axle shaft is pivotally supported by the steering knuckle. Is pivotally supported on the axle end by a kingpin having an axis pointing almost at the center of the joint, and the knuckle arm that is loosely inserted and connected to the steering knuckle receives steering force to change the direction of the drive wheels. As a result, the ground clearance of the vehicle body is secured, and a waist height structure that is strong against rough terrain is easily realized.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a longitudinal sectional view showing an embodiment of a drive wheel steering apparatus according to the present invention.

The drive wheel steering device 41 shown in FIG. 1 is applied to the front wheels of a four-wheel drive vehicle. The wheel 43 on which the tire 42 is mounted is fixed to the outer surface of the front axle hub 44 by tightening bolts, and the brake disc 45 is bolted to the inner surface of the front axle hub 44. A straight sleeve 46 integral with the front axle hub 44 is rotatably supported by a pair of bearings 48, 49 provided in a housing 47, and the front axle hub 44 is large by a wheel axle 50 inserted through the straight sleeve 46. It is integrated with the driven gear 51 of diameter. Therefore, the front axle hub 44 rotates together with the drive wheel 53, that is, the front wheel, by the rotational power transmitted through the small-diameter drive gear 52 meshing with the driven gear 51. The housing 47 holding the two bearings 48 and 49 is bolted and fixed to the end surface of the steering knuckle 54, and the steering knuckle 54 is pivotally coupled to the axle end 56 by a king pin 55, and further the knuckle arm. It is connected to a steering device (not shown) via 57. Therefore, turning the steering wheel (not shown) left and right causes the knuckle arm 57 to swing, and the direction of the drive wheel 53 changes.

The shaft 58 of the drive gear 52 is connected to an axle shaft 60 via a constant velocity joint 59, and the rotation of the axle shaft 60 is transmitted to the drive gear 52 at a constant velocity regardless of the direction of the drive wheel 53. It is like this. The axle end 56 is fixed to an end surface of an axle housing 61 through which the axle shaft 60 is inserted and held, and has a function of holding the central axis of the king pin 55 so as to always point to the center of the constant velocity joint 59. Like the bare ring 62 in the axle housing 61, the axle end 56 rotatably supports the axle shaft 60 by a built-in bearing 63. Here, the axle end 56 is attached so as to extend to the lower side of the axle housing 61. Then, a knuckle arm 57 for turning the steering knuckle 54 freely swingably inserts a window portion 64 formed in the axle end 56 over a predetermined angle range.

By the way, the engine power transmitted to the axle shaft 60 is transmitted to the drive gear 52 in the drive wheel 53 via the constant velocity joint 59. The rotation of the drive gear 52 is reduced by the driven gear 51 and transmitted to the front axle hub 44, and the drive wheel 53 rotates together with the front axle hub 44. When the knuckle arm 57 is swung by a steering mechanism (not shown), the steering knuckle 54 turns around the king pin 55 and the drive wheels 53 are steered in a predetermined direction.

Further, in the embodiment, the wheel shaft 50, which is the center of rotation of the drive wheel 53, moves downward with respect to the axle shaft 60 by the axial distance between the two gears 51 and 52 forming the reduction gear mechanism 65. It is offset. In other words, the axle shaft 60 can be offset upward by the axial distance between the drive gear 52 and the driven gear 51 with respect to the wheel shaft 50 that is the center of rotation of the drive wheel 53. That is, contrary to the drive wheel manipulating device 41 previously proposed by the applicant, it is possible to take a waist-high vehicle posture and hold the chassis at a height suitable for running on rough terrain.

As described above, according to the drive wheel steering apparatus 41, the rotational power from the axle shaft 60 is transmitted through the constant velocity joint 59, and the wheel shaft 50 around the wheel shaft 50 having a higher ground clearance than the axle shaft 60 is transmitted. A drive wheel 53 that rotates is pivotally supported on a steering knuckle 54, and the steering knuckle 54 is pivotally supported on a axle end 56 by a king pin 55 having an axis oriented substantially at the center of a constant velocity joint 59. The knuckle arm 57, which is loosely inserted and connected to the steering knuckle 54, is configured to change the direction of the drive wheels 53 in response to the steering force. The ground clearance of the vehicle body can be increased, which secures the ground clearance of the vehicle body and provides a waist height structure that is strong against rough terrain. Can be easily achieved. Furthermore, the king pin 55 that pivotally supports the steering knuckle 54 on the axle end 56 does not participate in the power transmission from the axle shaft 60 to the wheel shaft 50, but only in the transmission of the steering force. Appropriate and appropriate strength design is possible.

Further, a reduction gear mechanism 65 including a drive gear 52 connected to the constant velocity joint 59 and a driven gear 51 arranged on the wheel shaft 50 is built into the drive wheel 53, and the drive gear 52 is provided. Since the wheel shaft 50 is offset below the axle shaft 60 by the axial distance between the driven gear 51 and the driven gear 51, the offset distance can be easily changed by changing the specifications of the drive gear 52 and the driven gear 51. A versatile and flexible design that allows for the position of the center of gravity of the entire vehicle is possible.

Furthermore, the axle end 56 is fixed to an end portion of an axle housing 61 that rotatably supports the axle shaft 60, rotatably supports the axle shaft 60, and also the steering knuckle 54 and the drive wheel 53. Since the structure is fixed to the housing 47 that houses the bearings 48 and 49 that rotatably support the wheel shaft 50, the axle end 56 and the steering knuckle 54 rotatably connected thereto are different from each other. The constant velocity joint 59, which allows power transmission in the direction, can be firmly held, whereby the axis of the king pin 55 that pivotally supports the steering knuckle 54 on the axle end 56 places a strong burden on the king pin 55. Can always be directed to the center of the constant velocity joint 59, Stable steering becomes possible.

[0018]

[Effect of device]

 As described above, according to the present invention, the wheel axle of the drive wheel rotatably connected to the axle shaft by the joint is supported by the steering knuckle lower than the axle shaft, and Since the steering knuckle is turned by the knuckle arm that is displaced by, the chassis ground clearance can be increased by the axial distance between the axle shaft and the wheel shaft, which secures the ground clearance of the vehicle body. In addition, it is possible to easily realize a high waist configuration that is strong on rough terrain, and the king pin that pivotally supports the steering knuckle at the axle end does not participate in power transmission from the axle shaft to the wheel axle, but simply steers it. Since it is only involved in the transmission of force, it is possible to design an appropriate strength that is suitable for that purpose. An effect.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a drive wheel steering apparatus according to the present invention.

FIG. 2 is a vertical sectional view showing an example of a conventional steering device for driving wheels.

FIG. 3 is a vertical cross-sectional view showing an example of a drive wheel steering apparatus previously proposed by the applicant.

[Explanation of symbols]

 41 Drive Wheel Steering Device 50 Wheel Shaft 54 Steering Knuckle 55 King Pin 56 Axle End 57 Knuckle Arm 59 Constant Velocity Joint 60 Axle Shaft

Claims (1)

[Scope of utility model registration request] 1. A drive wheel, which is rotated around a wheel shaft having a ground clearance lower than that of the axle shaft, to which rotational power from the axle shaft is transmitted, and a steering knuckle for axially supporting the drive wheel. An axle end that pivotally supports the steering knuckle by a kingpin having an axis that points substantially at the center of the joint, and the axle end is loosely inserted and connected to the steering knuckle, and the steering wheel receives the steering force to change the direction of the drive wheels. A drive wheel steering device comprising: a knuckle arm to be changed.