WO2019054383A1

WO2019054383A1 - Hub unit with auxiliary steering function and vehicle comprising said hub unit

Info

Publication number: WO2019054383A1
Application number: PCT/JP2018/033679
Authority: WO
Inventors: 佑介大畑; 大場　浩量
Original assignee: Ntn株式会社
Priority date: 2017-09-15
Filing date: 2018-09-11
Publication date: 2019-03-21
Also published as: JP2019051846A

Abstract

A hub unit (1) with an auxiliary steering function comprises: a hub bearing (3) that has an inner race (12) that is a rotating race to which a wheel is attached, and an outer race (11) that is a fixed race ; and an outer-race-support member (5) that supports the outer race (11), with a rotation-permitting support component (7) interposed therebetween, at each of two locations vertically so as to allow rotation around a vertically extending auxiliary steering shaft center A. The outer race (11) has: a cylindrical outer race body (61) that has a raceway groove (11a) for a rolling element formed on the inner circumference; and an auxiliary steering member (62) provided with supported parts (19A, 19B) that are supported so as to be capable of rotating around the auxiliary steering shaft center (A) on rotation-permitting support components at the outer circumference side of the outer race body (61). The outer race body (61) and the auxiliary steering member (62) are separate components that are joined to each other.

Description

Hub unit with auxiliary steering function and vehicle equipped with the same

Related application

This application claims the priority of Japanese Patent Application No. 2017-177741 filed on Sep. 15, 2017, which is incorporated by reference in its entirety.

The present invention relates to a hub unit with an auxiliary steering function and a vehicle having a function of performing additional steering such as rear wheel steering and the like to be added to steering by a steering device, stability and safety of travelability. Related to the improvement of technology.

In a vehicle such as a general automobile, a steering wheel and a steering device are mechanically connected, and both ends of the steering device are connected to respective left and right wheels by tie rods. Therefore, the cut angle of the left and right wheels due to the movement of the steering wheel is determined by the initial setting. In the geometry of the vehicle, (1) "parallel geometry" in which the turning angle of the left and right wheels are the same, (2) cut the turning inner wheel tire angle larger than the turning outer wheel tire angle in order to make the turning center one place. Ackerman geometry is known.

The geometry of the vehicle affects the stability and safety of the runnability.

Patent Documents

1 and 2, for example, have been proposed as to a mechanism in which the steering geometry is variable according to the traveling situation. In Patent Document 1, the steering geometry is changed by relatively changing the knuckle arm and the joint position. In Patent Document 2, two motors are used, and it is possible to incline both the toe angle and the camber angle to an arbitrary angle. Patent Document 3 proposes a four-wheel independent steering mechanism.

JP, 2009-226972, A German Patent Application Publication No. 102012206337 JP, 2014-061744, A

Ackerman geometry is the difference in steering angle between left and right wheels so that each wheel turns around a common point in order to make the wheels turn smoothly when turning at low speed where the centrifugal force acting on the vehicle can be ignored Is set. However, since it is desirable for the wheel to generate a cornering force in a direction that balances the centrifugal force, it is preferable to use a parallel geometry rather than an Ackerman geometry in turning in a high speed region where the centrifugal force can not be ignored.

As described above, since a general vehicle steering system is mechanically connected to the wheels, generally only a single fixed steering geometry can be taken, and the middle between Ackerman geometry and parallel geometry It is often set to a static geometry. However, in this case, the steering angle difference between the left and right wheels is insufficient in the low speed region, the steering angle of the outer ring becomes excessive, and the steering angle of the inner ring becomes excessive in the high speed region. Unnecessary bias in the tire lateral force distribution between the inner and outer rings in this way causes deterioration in running resistance, resulting in deterioration in fuel efficiency and early wear of the tire, and the inability to use the inner and outer rings efficiently, resulting in smooth cornering. Problems such as loss of

According to the proposals of

Patent Documents

1 and 2, the steering geometry can be changed, but there are the following problems. In Patent Document 1, as described above, the steering geometry is changed by relatively changing the positions of the knuckle arm and the joint, but a motor actuator that obtains such a large force that changes the geometry of the vehicle is used. Providing is very difficult due to space constraints. In addition, the change in tire angle due to the change at this position is small, and in order to obtain a large effect, it is necessary to make a large change, that is, a large movement.

In Patent Document 2, since two motors are used, the cost increases due to the increase in the number of motors, and the control becomes complicated. Also, by using the constant velocity joint to support the wheel with a toe angle and a camber angle, the hub unit supporting the wheel becomes larger in the radial direction.

Patent Document 3 can be applied only to a four-wheel independent steered vehicle, and the hub bearing is supported in a cantilever manner with respect to the steered shaft, so the rigidity is reduced, and the occurrence of excessive travel G causes the steering geometry to be reduced. It may change.

Moreover, when a reduction gear is provided on the turning shaft, a large power is required. For this reason, although the motor is enlarged, if the motor is enlarged, it becomes difficult to arrange the whole on the inner peripheral portion of the wheel. In addition, when a reduction gear having a large reduction ratio is provided, the responsiveness deteriorates.

In order to solve these problems, the present applicant has proposed the following (Japanese Patent Application Laid-Open Nos. 2008-279600, 2008-282544, 2008-283231, 2008-281593). Gazette). That is, in a hub unit that rotatably supports wheels of an automobile or the like, the hub bearing is rotatably supported about an auxiliary steering axis extending in the vertical direction, and the hub bearing is supported by the auxiliary steering actuator. Rotate around. As a result, the hub bearing can be freely rotated about the auxiliary steering axis, and independent steering of one wheel can be performed, and the toe angle of the tire can be arbitrarily changed according to the traveling condition of the vehicle. Can.

Each proposed hub unit with auxiliary steering function has a function to rotate the hub bearing around the auxiliary steering axis, so that the hub bearing, particularly the outer ring, has a complicated shape. Specifically, while the hub bearing 3 and the outer ring 11 of a vehicle such as a general automobile have the shapes shown in FIGS. 14 and 15, the proposed hub bearing 3 and the outer ring 11 are shown in FIGS. It is a shape. In addition, illustration of a rolling element is abbreviate | omitted in FIG. 14, FIG.

In FIG. 16 and FIG. 17, the outer ring 11 has a supported portion 19, an auxiliary steering force receiving portion 18, and a brake caliper mounting portion 36 which both project outward on the outer periphery. The supported portions 19 are provided at upper and lower two places on the outer periphery of the outer ring 11, and are rotatably supported by an outer ring supporting member (not shown) installed on the vehicle body via a suspension device. The auxiliary steering force receiving portion 18 is a portion that receives the force of the auxiliary steering actuator. The brake caliper attachment portion 36 is attached with a brake caliper to be in contact with a brake rotor provided on the inner ring 12.

Thus, when the outer ring 11 of the hub bearing 3 has a complicated shape, the rotation becomes unstable when processing the raceway groove 11a of the rolling element on the inner periphery while rotating the outer ring 11, and the accuracy of the raceway groove 11a is secured. It is difficult to do. Further, as the material of the outer ring 11 having the raceway groove 11a which requires accuracy, it is necessary to use a relatively expensive material such as SU material or S53C. The use of such expensive materials for the entire outer ring results in high material costs.

The object of the present invention is to perform auxiliary steering according to the traveling situation independently for the right and left wheels, improve the motion performance of the vehicle, and improve the stability and safety of traveling and the fuel consumption. Another object of the present invention is to provide a hub unit with an auxiliary steering function and a vehicle provided with the same, which can be easily manufactured at low cost by machining the outer ring of the hub bearing.

The hub unit with auxiliary steering function of the present invention is
A hub bearing having an inner ring which is a rotating ring to which the wheel is attached and an outer ring which is a fixed ring;
An outer ring supporting member installed on a vehicle body via a suspension device and rotatably supporting the outer ring of the hub bearing around an auxiliary turning shaft center extending in the vertical direction at two upper and lower positions through rotation permitting supporting parts;
Equipped with
The outer ring of the hub bearing is
A cylindrical outer ring main body in which a raceway groove of rolling elements is formed on the inner periphery,
An auxiliary steering member provided with a supported portion which is disposed on the outer peripheral side of the outer ring main body and supported rotatably around the auxiliary steering axis by the rotation-allowable support component;
Have
The outer ring main body and the auxiliary turning member are separate parts and are coupled to each other.

According to this configuration, the hub bearing that supports the wheels can be freely rotated about the auxiliary steered shaft center, so by applying a rotational force about the auxiliary steered shaft center to the outer ring of the hub bearing, Independent steering can be performed, and the toe angle of the tire can be arbitrarily changed according to the traveling condition of the vehicle.

The hub unit with the auxiliary steering function may be used as either a steered wheel such as a front wheel or a non-steered wheel such as a rear wheel. When the hub unit with the auxiliary steering function is used as a steered wheel, it is installed on a member whose direction can be changed by the steering device, thereby adding it to steering by the driver's steering wheel operation. Or it becomes a mechanism which makes a slight angle change of the tire interlocked with the left and right wheels. Since the tire angle can be arbitrarily changed independently of each other while traveling, it is possible to improve the motion performance of the vehicle and travel stably and safely. For example, it is possible to change the steering geometry while traveling, such as parallel geometry in high speed range turning and Ackerman geometry in low speed range. It is also possible to improve fuel consumption by setting an appropriate tire angle. When this hub unit with an auxiliary steering function is used as a non-steered rear wheel, it is possible to reduce the minimum turning radius at low speed traveling.

In addition, since the hub unit with the auxiliary steering function performs rotatable support around the auxiliary steering axis at two upper and lower positions respectively by the rotation-allowable support parts, both ends are supported and rigidity is secured, and the configuration is simple. It is. In this way, auxiliary steering according to the traveling situation can be performed independently for the left and right wheels, improving the motion performance of the vehicle, improving traveling stability and safety, and improving fuel consumption, and also simple. And it has a solid structure.

Since the outer ring of the hub bearing is divided into the outer ring body and the auxiliary steered member, the hub bearing can be assembled easily. In addition, since the outer ring body is cylindrical, the center of gravity is located on or near the axis. Therefore, when processing the raceway groove on the inner periphery while rotating the outer ring main body, the rotation of the outer ring main body is stabilized, and the raceway groove can be processed with high accuracy. Although it is necessary to use relatively expensive materials such as SUJ2 and S53C for the outer ring body where accuracy of the raceway groove is required, for auxiliary steering members where accuracy is not required compared to the outer ring body, it is relatively inexpensive Materials can be used, which can lead to cost savings.

In the hub unit with auxiliary steering function of the present invention, the auxiliary steering axis may extend in the vertical direction. The auxiliary steering axis may be any axis extending in the vertical direction, and may be slightly inclined. However, if it extends in the vertical direction, the change in the camber angle by the auxiliary steering is better suppressed. The increase in traveling resistance can be further suppressed. In addition, when the auxiliary turning axis extends in the vertical direction, it is easy to secure the arrangement area of the outer ring support member in the limited space of the tire house and the like.

In the hub unit with auxiliary steering function of the present invention, in the case of including an auxiliary steering actuator installed on the outer ring support member and rotating the hub bearing around the auxiliary steering axis, the auxiliary steering member is An auxiliary steering force receiving portion for receiving the force of the auxiliary steering actuator may be integrally provided on the outer periphery. When the auxiliary turning force receiving portion is integrally provided to the auxiliary turning member, the number of parts can be reduced as compared with the case where the auxiliary turning force receiving portion is a separate part from the auxiliary turning member.

In the hub unit with auxiliary steering function of the present invention, in the case of providing a brake for braking the rotation of the inner ring by bringing the brake rotor provided on the inner ring into contact with the brake caliper provided on the outer ring, The outer ring further has a brake caliper mounting member which is on the outer peripheral side of the outer ring main body and to which the brake caliper is attached, and the outer ring main body, the auxiliary steered member and the brake caliper mounting member are coupled to each other It may be done. As described above, when the outer ring of the hub bearing is divided into the outer ring body, the auxiliary steered member, and the brake caliper mounting member, assembly is more than in the case where the outer ring body and the auxiliary steered member are divided. improves. In addition, since the brake caliper mounting member can be made of a relatively inexpensive material, the cost can be reduced.

In the vehicle of the present invention, one or both of the front wheel and the rear wheel are supported using the hub unit with an auxiliary turning function according to any one of the above-described configurations of the present invention. Therefore, each effect mentioned above is acquired about the hub unit with an auxiliary steering function of this invention. The front wheels are generally steered wheels, but when the hub unit with an auxiliary steering function of the present invention is applied to the steered wheels, it is effective for toe angle adjustment during traveling. Also, although the rear wheels are generally non-steered wheels, when the hub unit with an auxiliary steering function of the present invention is applied to the non-steered wheels, some steering of the non-steered wheels will minimize The radius of rotation can be reduced.

Any combination of the at least two configurations disclosed in the claims and / or the description and / or the drawings is included in the present invention. In particular, any combination of two or more of the claims is included in the present invention.

The invention will be more clearly understood from the following description of the preferred embodiments with reference to the accompanying drawings. However, the embodiments and the drawings are for the purpose of illustration and description only and are not to be taken as limiting the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in multiple drawings indicate the same or corresponding parts.
It is a longitudinal cross-sectional view which shows the hub unit with an auxiliary | assistant steering function which concerns on one Embodiment of this invention, and the structure of the periphery of it. It is a horizontal sectional view which shows the hub unit with the auxiliary | assistant steering function, and the structure of the periphery of the same. It is a longitudinal cross-sectional view of the hub unit with the same auxiliary | assistant steering function. It is an external appearance perspective view of the hub unit with the same auxiliary | assistant steering function. It is a left view of the hub unit with the auxiliary steering function. It is the perspective view which abbreviate | omitted and represented the hub bearing of the hub unit with an auxiliary | assistant steering function, without a rolling element. It is a perspective view of the outer ring of the hub bearing. It is an assembly exploded view of the same outer ring. It is a horizontal sectional view showing the main steering neutral state of the hub unit with the auxiliary steering function. It is a horizontal sectional view showing the main steering non-neutral state of the hub unit with the auxiliary steering function. It is a horizontal sectional view showing the example of the actuator for auxiliary steering. It is a horizontal sectional view showing other examples of an actuator for auxiliary steering. It is a model top view of an example of vehicles to which a hub unit with an auxiliary steering function is applied. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a general steering hub of a vehicle without rolling elements. It is a perspective view of the outer ring of the steering hub. FIG. 2 is a perspective view of the proposed steering hub with the rolling elements omitted. It is a perspective view of the outer ring of the steering hub.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing the configuration of a hub unit with an auxiliary steering function according to an embodiment of the present invention and the periphery thereof, and FIG. 2 is a horizontal sectional view of the same. 1 and 2, the hub unit with auxiliary steering function (hereinafter simply referred to as "hub unit") 1 is a hub bearing 3 for supporting the wheel 2, an outer ring support member 5, and an auxiliary steering. Actuator 6 and a brake 14 (FIG. 2).

The hub unit 1 is added to the steered wheels in this embodiment, specifically, steered by the steering device 25 of the front wheels 2 _F of the vehicle 10 as shown in FIG. It is a mechanism. The hub unit 1 is installed on the knuckle 22. The steering device 25 is a device that steers the

front wheels

2 _F and 2 _F in response to an operation of a steering wheel (not shown). The hub unit 1, In addition, may be used as a mechanism for steering the rear wheels 2 _R as an adjunct to the front wheel steering.

In FIG. 1, the hub bearing 3 is an outer ring fixed / inner ring rotation type, the outer ring 11 is supported by the outer ring support member 5, and the wheel 2 is attached to the inner ring 12. The wheel 2 is composed of a wheel 8 and a tire 9. The hub bearing 3 is supported by the outer ring support member 5 at two upper and lower positions via rotation tolerant support parts 7 so as to be rotatable about an auxiliary turning shaft center A extending in the vertical direction. The auxiliary steering axis A is an axis different from the rotational axis O of the wheel 2 and is also different from the kingpin axis K which performs the main steering.

The auxiliary turning axis A extends in the vertical direction, but is different from the kingpin axis K, for example, in the vertical direction. In this embodiment, the auxiliary steering axis A is the intersection position P _K between the extension and the road surface S of the kingpin axis K, the intersection position P _A of the extension line and the road surface S of the auxiliary steering axis A is Both are designed to be located in the tire contact surface 9a. Furthermore, it is optimal that these intersection points P _K and P _A be in agreement with each other in order to minimize the slip of the tire 9. The "tire contact surface" refers to a place where the tire 9 is in contact with the road surface S in a state where one driver (equivalent to 55 kg) gets on the driver's seat.

The outer ring support member 5 is attached to the knuckle 22 of the suspension device 21 installed on the vehicle body 10A (see FIG. 13). The outer ring support member 5 may be provided integrally with the knuckle 22, that is, as a part of the knuckle 22. The suspension device 21 is a double wishbone type in this example, and has an upper arm 23 and a lower arm 24 connected via a shock absorber (not shown), and between the upper arm 23 and the tip of the lower arm 24 The knuckle 22 is installed so as to be rotatable around an inclined king pin axis K. The suspension device 21 may adopt other various types such as an independent suspension type. The knuckle 22 has a steering device connecting portion 22a protruding like an arm as shown in FIG. A steering device connecting portion 22 a of the knuckle 22 is rotatably connected to a tie rod 26 of the steering device 25.

3 is a longitudinal sectional view of the hub unit with auxiliary steering function, FIG. 4 is an external perspective view of the hub unit with auxiliary steering function, and FIG. 5 is a left side view of the hub unit with auxiliary steering function. As shown in FIG. 3, the hub bearing 3 is composed of an inner ring 12, an outer ring 11, and rolling elements 13 such as balls interposed between the inner and outer rings. A member on the vehicle body side and the wheel 2 are connected by the hub bearing 3. The hub bearing 3 is an angular ball bearing in which the rolling elements 13 are double-rowed in the illustrated example.

The inner ring 12 has two rows of raceway grooves 12a of the rolling element 13 formed on the outer periphery, and has a hub flange 12b at the outboard end. As shown in FIG. 2, the wheel 8 of the wheel 2 is bolted to the hub flange 12b so as to overlap the brake rotor 14a described later. The inner ring 12 rotates about the rotation axis O.

The brake 14 has a brake rotor 14 a provided on the inner ring 12 and a brake caliper 14 b provided on the outer ring 11. The brake 14 brakes the rotation of the inner race 12 and the wheel 2 by bringing the brake caliper 14 b into contact with the brake rotor 14 a provided on the hub flange 12 b of the inner race 12. The brake caliper 14 is attached to a later described brake caliper attachment portion 36 provided on the outer ring 11.

FIG. 6 is a perspective view of the hub bearing with the rolling elements omitted, and FIG. 7 is a perspective view of the outer ring of the hub bearing. As shown in FIG. 3, FIG. 6, and FIG. 7, the outer ring 11 is supported by two

support portions

19A and 19B at upper and lower positions rotatably supported around the auxiliary steering axis A by the rotation allowing

support parts

7 and 7, respectively. Around the perimeter. The supported

portions

19A and 19B in this embodiment are trunnion shafts that protrude outward. In the upper supported portion 19A, a male screw portion 19a is formed at the tip. In the lower supported portion 19B, a screw hole 19b (FIG. 3) extending in the axial direction is formed in the tip end surface.

In FIG. 3, each rotation allowing support component 7 is a tapered roller bearing, and the inner ring 15 is fitted on the outer periphery of the supported portion 19A (or 19B), and the outer ring 16 is provided on the outer ring support member 5 It is fitted in the hole 38. The inner ring 15 is pressed in the axial direction by a nut 39 which is screwed to the male screw 19a of the supported portion 19A. The lower end of the outer ring 16 is supported by the bolt 42 in which the pressing member 41 is fitted in the fitting hole 38 of the outer ring support member 5 and screwed into the screw hole 19 b of the supported portion 19B. Is pressing.

The pressing by the nut 39 and the bolt 42 applies a pre-load to the upper and lower rotation allowing support parts 7 formed of tapered roller bearings. The outer ring support member 5 is divided into one outer ring support member main member 5 a and an outer ring support member divided body 5 b provided for each of the rotation allowing

support parts

7 and 7, and they are mutually connected by bolts 44. .

In addition, the attachment structure with respect to the outer ring | wheel support member 5 of upper and lower rotation

permission support components

7 and 7 may mutually be the same structure. For example, even if the structure for fixing the upper rotation allowing support member 7 to the outer ring support member 5 and the hub bearing 3 to the outer ring 11 in FIG. 3 is applied to the lower rotation allowing support member 7, The fixing structure of the tolerant support part 7 may be applied to the fixing of the upper rotation tolerant support part 7.

Further, as shown in FIG. 2, FIG. 6, and FIG. 7, the outer wheel 11 has an auxiliary steering force receiving portion 18 receiving the force of the auxiliary steering actuator 6, and a brake caliper attachment portion to which the brake caliper 14 is attached. And 36 on the outer periphery.

The auxiliary steering force receiving portion 18 is a portion serving as an application point for applying the auxiliary steering force to the outer ring 11 of the hub bearing 3, and is provided as an arm portion integrally projecting on a part of the outer periphery of the outer ring 11. The auxiliary steering force receiving portion 18 is rotatably connected to the direct drive output portion 6a of the auxiliary steering actuator 6 via a joint 57 as will be described later with reference to FIG. Thereby, the hub bearing 3 is rotated around the auxiliary axis A, that is, the auxiliary steering is performed by the linear motion output unit 6a of the auxiliary steering actuator 6 advancing and retracting.

As shown in FIG. 2, the auxiliary steering actuator 6 includes a motor 27, a reduction gear 28 for decelerating the rotation of the motor 27, and forward and reverse rotational output of the reduction gear 28 of the direct movement output unit 6 a. It is comprised by the linear_motion | direct_drive mechanism 29 converted to reciprocating linear motion. The motor 27 is, for example, a permanent magnet type synchronous motor, but may be a direct current motor or an induction motor. As the reduction gear 28, a winding type transmission mechanism such as a belt transmission mechanism or a gear train can be used. In the example of FIG. 2, a belt transmission mechanism is used. The linear movement mechanism 29 can be a feed screw mechanism such as a slide screw or a ball screw, or a rack and pinion mechanism, and in this example, a feed screw mechanism using a slide screw of a trapezoidal screw is used. A mechanism is also possible that transmits the driving force of the motor 27 directly to the linear motion mechanism 29 without via the reduction gear.

The angle θ (see FIGS. 9 and 10) of the auxiliary steering with respect to the knuckle 22 of the hub bearing 3 is regulated by the stopper 35. FIG. 9 shows a state in which the main steering is in a straight-ahead state and the auxiliary steering is performed inward, and FIG. 10 shows a state in which the main steering is directed to the left and the auxiliary steering is performed inward. . The stopper 35 is provided, for example, on the surface of the outer ring support member 5 that faces the hub bearing 3 in the axial direction, for example, the surface that faces the end face of the outer ring 11 of the hub bearing 3. When the end face of the outer ring 11 abuts against the stopper 35, the angle θ of auxiliary steering of the hub bearing 3 is regulated. The allowable range of the auxiliary steerable angle of the hub bearing 3 may be a slight angle, and the allowable range of the auxiliary steerable angle by the stopper 35 is, for example, ± 5 degrees or less.

As shown in the assembly exploded view of FIG. 8, the outer ring 11 of the hub bearing 3 is composed of an outer ring main body 61 which is a separate member, an auxiliary turning member 62 and a brake caliper mounting member 63.

The outer ring main body 61 is a member in which the above-mentioned raceway groove 11a is formed on the inner circumference, and has a substantially cylindrical shape. The outer peripheral surface of the outer ring main body 61 is composed of a large diameter outer peripheral surface portion 61a which occupies most of the axial direction and a small diameter outer peripheral surface portion 61b located at one axial end. Then, coupling projections 61c are provided at equal locations in the circumferential direction at a plurality of locations (for example, 4 locations) of the large diameter outer peripheral surface portion 61a. The coupling protrusion 61c has a bolt insertion hole 61d penetrating in the axial direction.

The outer ring main body 61 is cylindrical, and since the plurality of coupling projections 61c are at equal positions, the center of gravity is located on or near the axis. Therefore, when processing the raceway groove 11a on the inner periphery while rotating the outer ring main body 61, the rotation of the outer ring main body 61 is stable, and the raceway groove 11a can be processed with high accuracy. Since the outer ring body 61 is required to have the accuracy of the raceway groove 11a, a relatively expensive material such as SU material or S53C is used.

The auxiliary steering member 62 is an annular member fitted to the large diameter outer peripheral surface portion 61 a of the outer ring main body 61. The trunnion shaft-shaped supported

portions

19A and 19B are provided at two upper and lower positions on the outer peripheral surface of the auxiliary turning member 62, and the arm-shaped auxiliary turning force receiving portion 18 is integrated with one side of the outer peripheral surface. Provided in Further, on one end side of the auxiliary turning member 62 in the axial direction, a plurality of notches 62a into which the coupling projections 61c of the outer ring main body 61 can be fitted are provided. A portion axially adjacent to the notched portion 62a is a convex portion 62b protruding to the outer diameter side, and an axial screw hole 62c is provided in the convex portion 62b. Since the auxiliary steering member 62 does not require accuracy as compared with the outer ring main body 61, a relatively inexpensive material is used.

The brake caliper mounting member 63 is an annular member fitted to the small diameter outer peripheral surface portion 61 b of the outer ring main body 61. The brake caliper mounting member 63 has the brake caliper mounting portion 36 on one side of the outer periphery. In a plurality of locations corresponding to the bolt insertion holes 61 d of the outer ring main body 61 in the brake caliper mounting member 63, bolt insertion holes 63 a penetrating in the axial direction are formed. Similarly to the auxiliary steering member 62, the brake caliper mounting member 63 does not require accuracy as compared with the outer ring main body 61, and therefore, a relatively inexpensive material can be used.

The outer ring 11 of the hub bearing 3 is assembled as follows. The auxiliary steering member 62 is fitted to the large diameter outer peripheral surface portion 61 a of the outer ring main body 61. At that time, the coupling projection 61c of the outer ring main body 61 is fitted into the notch 62a of the auxiliary turning member 62, and the outer ring main body 61 and the auxiliary turning member 62 are positioned in the circumferential direction. Further, the brake caliper mounting member 63 is fitted to the small diameter outer peripheral surface portion 61 b of the outer ring main body 61 from the side opposite to the auxiliary steering member 62 in the axial direction. At this time, the axial centers of the bolt insertion holes 61 d and 63 a of the outer ring main body 61 and the brake caliper mounting member 63 are made to coincide with each other. The brake caliper mounting member 63 abuts on the coupling projection 61 c of the outer ring main body 61 and the end surface of the auxiliary steering member 62.

In this state, the coupling bolt 64 is inserted in order of the bolt insertion hole 63a of the brake caliper mounting member 63 and the bolt insertion hole 61d of the outer ring main body 61, and the screw portion 64a is screwed into the screw hole 62c of the auxiliary steering member 62. Let Thereby, the outer ring main body 61, the auxiliary turning member 62, and the brake caliper mounting member 63 are combined and integrated with each other.

[Operation and action]
The operation and action of the hub unit 1 configured as described above will be described.
In FIGS. 1 and 2, the hub unit 1 is rotatable about the auxiliary steered axis A with respect to the outer ring support member 5 provided with the hub bearing 3 in the knuckle 22 (FIG. 1). The hub bearing 3 can be rotated by applying a force to the arm-like auxiliary steering force receiving portion 18 (FIG. 2). The hub bearing 3 is an auxiliary connected to the direct drive output unit 6 a by advancing and retracting the direct drive output unit 6 a (FIG. 2) of the auxiliary steering actuator 6 installed on the outer ring support member 5 by driving the motor 27. It is rotated via the turning force receiving unit 18.

The rotation of the hub bearing 3 is added to the turning by the driver's steering wheel operation, that is, added to the rotation of the knuckle 22 about the king pin axis K (FIG. 1) by the steering device 25 (see FIG. 13). It is done as a basic steering. Further, independent rotation of one wheel can be performed by the rotation of the hub bearing 3. The toe angles between the left and

right wheels

2 and 2 can be arbitrarily changed by making the auxiliary steering angles of the left and

right wheels

2 and 2 different.

In FIG. 13, according to the traveling conditions of the vehicle 10, the tire angle can be arbitrarily changed independently of each other during traveling, so that the exercise performance of the vehicle 10 can be improved to travel stably and safely. It becomes possible. It is also possible to improve fuel consumption by setting an appropriate tire angle. The hub unit 1 in the case of using the wheels 2 _R after a non-steering wheels, it is possible to reduce the minimum turning radius during low-speed running.

In FIG. 1 and FIG. 2, since the hub unit 1 performs rotatable support around the auxiliary steering axis A at two upper and lower positions respectively by the rotation allowing

support parts

7 and 7, both ends are supported to ensure rigidity. Is simple and easy to configure. In this way, while securing the rigidity, the auxiliary steering according to the traveling situation can be performed independently with the simple structure, and the toe angle of the wheel 2 can be arbitrarily changed, and the steering geometry Therefore, it is possible to improve the exercise performance of the vehicle 10, to improve the stability and safety of traveling and to improve the fuel consumption.

A control example of the steering angle difference between the left and right wheels according to the traveling speed will be described. As described above, since a general vehicle steering apparatus is mechanically connected to the wheels, only a fixed single steering geometry can be taken, and an intermediate geometry between the Ackerman geometry and the parallel geometry It is often set to In this case, the steering angle difference between the left and right wheels is insufficient in the low speed region, and the steering angle of the outer ring becomes excessive, and the steering angle of the inner wheel becomes excessive in the high speed region. If an unnecessary bias occurs in the tire lateral force distribution of the inner and outer rings due to such steering angle problems etc., it causes deterioration of the fuel consumption due to the deterioration of the running resistance and early wear of the tires, and the inner and outer rings can not be used efficiently. , The smoothness of cornering is lost.

Since the hub unit 1 of this embodiment can control the left and right wheels 2 individually, the steering angle of the wheels 2, that is, the turning angle is changed according to the vehicle speed and the turning G, and Ackerman geometry (each wheel Increase travel resistance by arbitrarily selecting the steering angle difference between the left and right wheels so that they turn about a common point) and parallel geometry (the steering angles of the left and right wheels are the same) in the high-speed range It is possible to achieve both smooth turnability at low speed and cornering performance at high speed.

The auxiliary steering axis A may be any axis extending in the vertical direction, and may be inclined to some extent, but in this embodiment extends in the vertical direction, and the change of the camper angle by the auxiliary steering Can be better suppressed, and the increase in running resistance can be further suppressed. When the kingpin axis K and the auxiliary steering axis A coincide with each other, if the hub bearing 3 is steered with the kingpin axis K as an auxiliary steering wheel, the camber angle largely changes and the traveling resistance increases. However, by setting the auxiliary turning axis A separately from the kingpin axis K, it is possible to suppress the change in the camber angle due to the auxiliary turning and to suppress the increase in the running resistance. In addition, when the kingpin axis K and the auxiliary steered axis A coincide with each other, the component parts are disposed on the vehicle side of the hub bearing 3 and the overall size becomes heavy, but the auxiliary steered axis A In a direction different from the kingpin axis K of the suspension device 21, the size of the entire device can be reduced and the weight can be reduced.

Furthermore, the intersecting point P _K between the extension and the road surface S of the kingpin axis K of the suspension system 21, the intersection position P _A of the extension line and the road surface of the auxiliary steering axis A are both positioned within the tire ground contact surface 9a Therefore, both the main steering and the auxiliary steering can be performed stably and efficiently. When the kingpin axis K and the auxiliary steering axis A are different, if the extension of both axes and the contact position of the tire 9 are different, slippage occurs if both move at the same time, which is inefficient and Behavior may be disturbed. Therefore, it is desirable that the intersecting point P _K between the extension and the road surface S of the kingpin axis K, the intersection P _A between the extension line and the road surface S of the auxiliary steering axis A is arranged close to each other. Ideally, it is preferable that the two points P _{A and} P _K coincide with each other, so that even if the main steering and the auxiliary steering are simultaneously performed, slip does not occur and the main steering and the main steering efficiently. Auxiliary steering can be performed, and the vehicle can be operated stably.

With regard to the angle of auxiliary steering, a slight angle is sufficient to improve the motion performance of the vehicle and the stability and safety of traveling, and it is sufficient even if the auxiliary steerable angle is ± 5 degrees or less. Although the angle of the auxiliary steering is controlled by the control of the auxiliary steering actuator 6, since the stopper 35 is provided and regulated, even if the hub unit 1 breaks down due to a failure of the power supply system, It is prevented that a big influence arises. Therefore, the vehicle can be brought to a safe place by steering operation.

Since the rotation allowing support component 7 is formed of a tapered roller bearing, a preload can be applied between the inner ring 15 and the outer ring 16 by tightening or the like at the time of attachment, and rigidity can be enhanced. Note that the rotation tolerant support part 7 may use an angular contact ball bearing or a four-point contact ball bearing instead of the tapered roller bearing. Also, the rotation allowing support component 7 may be a spherical slide bearing such as a spherical bush, a pivot bearing or the like. Also in this case, preload can be applied as described above.

Since the outer ring 11 of the hub bearing 3 is divided into the outer ring body 61, the auxiliary steering member 62, and the brake caliper mounting member 63, the hub bearing 3 can be assembled easily. Further, since the outer ring body 61 is cylindrical and the plurality of coupling projections 61c are at equal positions, the rotation of the outer ring body 61 is stable when the raceway groove 11a is processed on the inner periphery while the outer ring body 61 is rotated. Thus, the raceway groove 11a can be machined with high accuracy.

Although it is necessary to use relatively expensive materials such as SUJ2 material and S53C for the outer ring main body 61 where the accuracy of the raceway groove 11a is required, the auxiliary steering member 62 and the brake which do not require accuracy as compared with the outer ring main body 61 A relatively inexpensive material can be used for the caliper attachment member 63, whereby the cost can be reduced.

In this embodiment, the auxiliary steering force receiver 18 is provided integrally with the auxiliary steering member 62, but it is possible to transmit the force of the auxiliary steering actuator 6 to the auxiliary steering member 62. The auxiliary steering force receiving portion 18 may be a separate member from the auxiliary steering member 62. Moreover, although the outer ring 11 is divided into the outer ring main body 61, the auxiliary steering member 62, and the brake caliper mounting member 63 in this embodiment, the auxiliary steering member 62 and the brake caliper mounting member 63 are integrated. May be

[Example of auxiliary steering actuator]
FIG. 11 shows a specific example of the auxiliary steering actuator 6. The driving force of the motor 27 is transmitted to the drive pulley 51 coupled to the motor shaft 27a, and is transmitted by the belt 53 to a driven pulley 52 disposed parallel to the motor shaft 27a. The

pulleys

51 and 52 and the belt 53 constitute a winding type reduction gear 28.

The screw shaft 54 in the linear motion mechanism 29 which is a feed screw mechanism is disposed in a screwing manner on the nut 55 on the inner periphery of the driven pulley 52. The nut 55 and the screw shaft 54 have a thread groove and a screw thread constituting a screw portion 58 of a slide screw, specifically, a trapezoidal screw having a self-locking function. The rotation of the nut 55, which rotates integrally with the driven pulley 52, causes the screw shaft 54 to move in a linear motion back and forth because the screw shaft 54 is detentated by the detent portion 56.

An arm-like auxiliary steering force receiving portion 18 provided on the outer ring 11 of the hub bearing 3 is connected to the direct acting output portion 6 a at the tip of the screw shaft 54 via a joint 57. The joint 57 is rotatably connected to the auxiliary steering force receiving portion 18 and the direct acting output portion 6 a by two pins 57 a. For this reason, the hub bearing 3 can rotate around the auxiliary steered shaft center A with respect to the outer ring support member 5 by the forward and backward movement of the screw shaft 54. In this embodiment, although the driven pulley 52 and the nut 55 of the linear motion mechanism 29 are separately manufactured, they are combined, but the driven pulley 52 and the nut 55 are integrally manufactured with each other. It may be part of another part.

As described above, when a slide screw having a self-locking function is used as the linear movement mechanism 29, reverse input from the tire is prevented, and even when the motor 27 fails, the self-locking function stabilizes the tire 9 Instead, the vehicle can be moved to a safe place by the steering wheel operation, ensuring safety. In addition, when the direct acting mechanism 29 has a self-locking function, it is possible to keep the constant auxiliary steering angle at the time of not performing the auxiliary steering or at the time of high speed traveling, etc. The drive of 27 is unnecessary and motor power can be reduced.

[Another example of the auxiliary steering actuator]
FIG. 12 shows another specific example of the auxiliary steering actuator 6. The driving force of the motor 27 is transmitted to a drive gear 59 coupled to the motor shaft 27a, and is transmitted to a driven gear 60 disposed parallel to the motor shaft 27a. The drive gear 59 and the driven gear 60 constitute a gear train serving as the reduction gear 28.

The screw shaft 54 of the linear movement mechanism 29 including a feed screw mechanism is screwed to a nut 55A provided at the center of the driven gear 60. The configuration of the linear movement mechanism 29 and the connection between the linear movement mechanism 29 and the hub bearing 3 are the same as in the example shown in FIG. That is, the nut 55A and the screw portion 58 of the screw shaft 54 are slide screws, and more specifically, are trapezoidal screws having a self-locking function. The rotation of the nut 55A, which rotates integrally with the driven pulley 52, causes the screw shaft 54 to move in a linear motion back and forth because the screw shaft 54 is locked by the locking portion 56.

An arm-like auxiliary steering force receiving portion 18 provided on the outer ring 11 of the hub bearing 3 is connected to the direct acting output portion 6 a at the tip of the screw shaft 54 via a joint 57. The joint 57 is rotatably connected to the auxiliary steering force receiving portion 18 and the direct acting output portion 6 a by two pins 57 a. For this reason, the hub bearing 3 can rotate around the auxiliary steered shaft center A with respect to the outer ring support member 5 by the forward and backward movement of the screw shaft 54. In this embodiment, although the driven gear 60 and the nut 55A of the linear movement mechanism 29 are integrally manufactured, the driven gear 60 and the nut 55A are integrally manufactured and mutually coupled. It may be one.

Also in the case of this embodiment, as in the embodiment of FIG. 11, since a slide screw having a self-locking function is used for the linear movement mechanism 29, the above-described effects can be obtained by the self-locking function. Further, in the case of this embodiment, since the reduction gear 28 is composed of a gear train, drive transmission with high rigidity and high responsiveness is possible.

It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

DESCRIPTION OF SYMBOLS 1 ... Hub unit with auxiliary steering function 2 ... Wheel 3 ... Hub bearing 5 ... Outer ring support member 6 ... Actuator for auxiliary steering 7 ... Rotation permission support parts 10 ... Vehicle 10A ... Car body 11 ... Outer ring 11a ... Track groove 12 ... inner ring 13 Rolling element 14 Brake

14a Brake rotor

14b Brake caliper 18 Auxiliary steering

force receiving portion

19A, 19B Supported portion 21 Suspension device 36 Brake caliper mounting portion 61 Outer ring main body 62 Auxiliary steering member 63 ... Brake caliper mounting member A ... Auxiliary steering axis

Claims

A hub bearing having an inner ring which is a rotating ring to which the wheel is attached and an outer ring which is a fixed ring;
An outer ring supporting member installed on a vehicle body via a suspension device and rotatably supporting the outer ring of the hub bearing around an auxiliary turning shaft center extending in the vertical direction at two upper and lower positions through rotation permitting supporting parts;
Equipped with
The outer ring of the hub bearing is
A cylindrical outer ring main body in which a raceway groove of rolling elements is formed on the inner periphery,
An auxiliary steering member provided with a supported portion which is disposed on the outer peripheral side of the outer ring main body and supported rotatably around the auxiliary steering axis by the rotation-allowable support component;
Have
The outer ring body and the auxiliary steering member are separate parts and are coupled to each other,
Hub unit with auxiliary steering function.
The hub unit with an auxiliary steering function according to claim 1, wherein the auxiliary steering axis extends in the vertical direction.
The hub unit with an auxiliary steering function according to claim 1 or 2, further comprising: an auxiliary steering actuator installed on the outer ring support member to rotate the hub bearing around the auxiliary steering axis.
A hub unit with an auxiliary steering member auxiliary steering function, wherein the auxiliary steering member is integrally provided with an auxiliary steering force receiving portion for receiving the force of the auxiliary steering actuator on an outer periphery thereof.
The hub unit with auxiliary steering function according to any one of claims 1 to 3, wherein the rotation of the inner ring is made by bringing the brake rotor provided on the inner ring into contact with the brake caliper provided on the outer ring. Equipped with a brake to brake the
The outer ring of the hub bearing further has a brake caliper mounting member on the outer periphery side of the outer ring main body and to which the brake caliper is attached. The outer ring body, the auxiliary steering member, and the brake caliper mounting Hub unit with auxiliary steering function in which the parts are connected to one another.
A vehicle in which one or both of a front wheel and a rear wheel are supported by using the hub unit with an auxiliary steering function according to any one of claims 1 to 4.