JP6390262B2 - Vehicle steering device - Google Patents

Description

  The present invention relates to a vehicle steering apparatus including a steering mechanism that turns a tire around a kingpin shaft by rotation of a cross shaft gear.

  2. Description of the Related Art Conventionally, as a vehicle steering device, there is known a vehicle steering device that is disposed on an axis of a kingpin shaft and has a steering mechanism that turns a tire around the kingpin shaft by rotation of a face gear (crossed shaft gear). (For example, refer to Patent Document 1).

JP2013-103665A

  However, in the conventional device, the meshing part of the pinion gear and the face gear is at an offset position shifted in the radial direction from the kingpin shaft, but the face gear back surface is attached by a spring arranged coaxially with the kingpin shaft. It was fast. Therefore, when a meshing load is applied to the cross shaft gear, a moment (= offset amount × load) is generated in the face gear due to the meshing load, and the rotation axis of the face gear is inclined due to the generation of the moment. There is a problem that the meshing rigidity backlash performance of the cross shaft gear is deteriorated due to the axis tilt of the face gear.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a vehicle steering apparatus capable of improving the meshing rigidity play of the cross shaft gear.

In order to achieve the above object, the present invention includes a steering mechanism that is disposed on the axis of the kingpin shaft and that turns the tire around the kingpin shaft by the rotation of the cross shaft gear.
In this vehicle steering apparatus, a spring member that presses against the gear meshing portion of the cross shaft gear and applies a spring force is disposed below the gear meshing portion of the cross shaft gear.
The cross shaft gear is an inconstant speed face gear that rotates by meshing with a pinion gear that rotates by turning input, and has a tooth shape changed by a rotation phase.
A pressing force adjusting member that changes the pressing spring force of the spring member according to the rotational phase of the inconstant speed face gear is disposed .

Therefore, when the tire is steered around the kingpin shaft, the cross shaft gear rotates in a state in which a spring force is applied to the gear meshing portion by the spring member disposed below the gear meshing portion of the cross shaft gear. .
In other words, when a meshing load is generated in the cross-shaft gear during turning or the like, the pressing spring force applied to the gear meshing portion not only acts in the direction of reducing the gap between the gear tooth surfaces, but also reduces the meshing load. Acting in the direction to cancel, that is, the direction to cancel the generation of moment.
As a result, the shaft tilt of the cross shaft gear due to the generation of moment is suppressed, and the meshing rigidity play of the cross shaft gear can be improved.
In addition, the cross shaft gear is an inconstant speed face gear, and a pressing force adjusting member that changes the pressing spring force by the spring member according to the rotational phase of the inconstant speed face gear is arranged. For this reason, at any rotational phase of the inconstant speed face gear whose tooth shape changes, it is possible to suppress an increase in friction and a deterioration in rigidity play performance.

It is a vehicle rear view which shows the motor drive steered wheel with which the steering device for in-wheel motor vehicles of Example 1 was applied with a steering mechanism and a suspension mechanism. It is sectional drawing which shows the steering mechanism (rotation phase A) in the steering device for in-wheel motor vehicles of Example 1. FIG. It is sectional drawing which shows the steering mechanism (rotation phase B) in the steering apparatus for in-wheel motor vehicles of Example 1. FIG. It is a top view which shows the meshing state of the pinion gear of the steering mechanism in the steering apparatus for in-wheel motor vehicles of Example 1, and a face gear. FIG. 5 is a perspective view of the face gear in the steering mechanism of the first embodiment when viewed from the direction of arrow C in FIG. 4. FIG. 5 is a perspective view of the face gear in the steering mechanism of the first embodiment when viewed from the direction of arrow D in FIG. 4. It is force relationship explanatory drawing which shows the relationship between the tangential force and radial force by meshing | engagement of the pinion gear and face gear in the steering mechanism of Example 1. FIG. It is sectional drawing which shows the steering mechanism in the steering device for in-wheel motor vehicles of Example 2. FIG. It is sectional drawing which shows the steering mechanism in the steering device for in-wheel motor vehicles of Example 3. FIG. FIG. 10 is a plan view showing the positions of teeth of a face gear in the steering mechanism of the third embodiment. FIG. 10 is a plan view showing the position of a spring group in the steering mechanism of the third embodiment. It is a perspective view which shows the spring group and pressing force adjustment plate in the steering mechanism of Example 3. FIG.

  Hereinafter, the best mode for realizing the vehicle steering device of the present invention will be described based on Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
The configuration of the in-wheel motor vehicle steering device (an example of a vehicle steering device) according to the first embodiment will be described by dividing it into “the overall configuration of the motor-driven steered wheels” and “the detailed configuration of the steered mechanism”.

[Overall configuration of motor-driven steered wheels]
FIG. 1 shows a motor-driven steered wheel to which a steering device for an in-wheel motor vehicle is applied, together with a steered mechanism and a suspension mechanism. Hereinafter, based on FIG. 1, the whole structure of a motor drive steered wheel is demonstrated.

  As shown in FIG. 1, the motor-driven steered wheel 1 includes an in-wheel motor drive unit 2, a unit case 3, a wheel hub 4, and a brake disk 5.

  The motor-driven steered wheels 1 are integrally provided with individual in-wheel motor drive units 2 and are individually driven to rotate around the wheel center CL by the in-wheel motor drive unit 2. Therefore, the in-wheel motor drive unit 2 incorporates an electric motor and a speed reducer (transmission) (not shown) in the unit case 3, connects the electric motor to the input shaft of the speed reducer, and outputs the output shaft of the speed reducer. The wheel hub 4 is coupled to the wheel.

  The wheel hub 4 is connected to the motor-driven steered wheels 1 and to the brake disk 5, thereby transmitting the power from the electric motor to the motor-driven steered wheels 1 under deceleration by a speed reducer. to enable. Then, the brake disc 5 is clamped from both sides in the axial direction by a brake caliper (not shown) attached to the in-wheel motor drive unit 2 so that the vehicle can be braked.

  As shown in FIG. 1, the suspension mechanism includes an upper arm 6, a lower arm 7, a third link 8, a shock absorber 9, an insulator 10, and a knuckle 11. The motor-driven steered wheel 1 suspended on the vehicle body via the unit case 3 by this suspension mechanism can bounce / rebound in the vertical direction together with the in-wheel motor drive unit 2 while attenuating vertical vibrations by the shock absorber 9. .

  The upper arm 6 is an upper suspension arm that extends in the vehicle width direction above the unit case 3, and includes a vehicle body side support portion 6a and a third link side support portion 6b. That is, the upper arm 6 supports the upper end portion of the third link 8 so as to be swingable with respect to the vehicle body.

  The lower arm 7 is a lower suspension arm that extends in the vehicle width direction below the unit case 4, and includes a vehicle body side support portion 7a and a knuckle side support portion 7b. That is, the lower arm 7 supports the knuckle lower end portion 11b of the knuckle 11 fixed to the unit case 3 so as to be swingable with respect to the vehicle body.

  The third link 8 is a third suspension member connected to the upper arm 6, the shock absorber 9, and the knuckle 11. The upper arm 6 is supported so as to be swingable via a third link side support portion 6b. The shock absorber 9 is swingably supported at the lower end of the piston rod 9a. The knuckle 11 is supported by a knuckle upper end portion 11a so as to be rotatable (the rotation axis is an axis centered on the kingpin axis Kp).

  The shock absorber 9 is a strut type in which a shock absorber and a coil spring are coaxially arranged, and has a piston rod 9a and a cylinder 9b. The lower end portion of the piston rod 9a is supported by the third link 8 so as to be swingable. The upper end portion of the cylinder 9 b is elastically supported by the vehicle body via the insulator 10.

  The knuckle 11 is a wheel steering member fixed integrally to the unit case 3, and includes a knuckle upper end portion 11 a extending upward from the unit case 3 and a knuckle lower end portion extending downward from the unit case 3. 11b. The knuckle upper end portion 11a is connected to the third link 8, and is also connected to an inconstant speed face gear 23 of the turning mechanism S1 described later via a turning shaft 12 (coaxial arrangement with the kingpin axis Kp). The knuckle lower end part 11b is connected to the lower arm 7 via the knuckle side support part 7b. A shaft connecting the knuckle upper end portion 11a and the knuckle lower end portion 11b is a kingpin shaft Kp, and the motor-driven steered wheel 1 and the in-wheel motor drive unit 2 can be steered around the kingpin shaft Kp. It can be performed.

[Detailed configuration of steering mechanism]
2 to 7 show the steering mechanism S1 in the steering device for an in-wheel motor vehicle according to the first embodiment. Hereinafter, based on FIGS. 2-7, the detailed structure of steering mechanism S1 of Example 1 is demonstrated.

  As shown in FIGS. 2 and 3, the steering mechanism S1 includes a gear case 21, a pinion gear shaft 22, an inconstant speed face gear 23 (crossed shaft gear), a pressing spring 24 (pressing member), and a pressing force. Adjustment plate 25 (pressing force adjusting member). The steered mechanism S1 is disposed at an upper position on the axis of the kingpin axis Kp, and causes the motor-driven steered wheels 1 to be steered around the kingpin axis Kp by the rotation of the inconstant speed face gear 23.

  The gear case 21 includes a gear support case portion 21a, a shaft support case portion 21b, and a case lid portion 21c. The gear support case portion 21a is fixed to the third link 8, and supports the inconstant speed face gear 23 so as to be rotatable around the kingpin axis Kp and displaceable in the axial direction of the kingpin axis Kp. The shaft support case portion 21b is fixed to the gear support case portion 21a, and supports the pinion gear shaft 22 at a position offset from the kingpin axis Kp and rotatably around a shaft axis SA orthogonal to the kingpin axis Kp. . The case lid portion 21c is fixed to the shaft support case portion 21b with a bolt or the like, and closes the gear chamber 26 from the upper surface.

  The pinion gear shaft 22 is a shaft member with a pinion gear rotatably supported by a shaft support case portion 21b of the gear case 21, and includes a pinion gear portion 22a, a first case support portion 22b, a second case support portion 22c, and a steering wheel. System connection part 22d. The pinion gear portion 22 a meshes with the gear portion 23 a of the inconstant speed face gear 23. The first case support portion 22b and the second case support portion 22c are supported at both ends in a sealable state with respect to the shaft support case portion 21b via a first bearing seal 27 and a second bearing seal 28. The steering system connecting portion 22d is mechanically connected to a steering wheel (not shown) that is operated by the driver when steering the vehicle, and inputs a steering force rotating from the steering wheel.

  The inconstant speed face gear 23 is coaxially arranged with the kingpin shaft Kp, and is connected to the steered shaft 12 inserted through the shaft hole 21d of the gear case 21 by key fixation. , A gear back surface portion 23b, a shaft hole portion 23c, and a key groove 23d. The gear tooth portion 23a rotates by meshing with the pinion gear portion 22a (gear meshing portion 29) and changes the tooth shape according to the rotational phase. The gear back portion 23 b is an elastic support surface for the gear case 21. The shaft hole portion 23c and the key groove 23d are configured to key-lock the steered shaft 12.

  As shown in FIGS. 2 and 3, the pressing spring 24 is a coil spring arranged as a pressing member that applies a pressing force in a direction to increase the gear meshing force to a position below the gear meshing portion 29 of the non-constant speed face gear 23. It is a member. The pressing spring 24 includes an intermediate member 30 that comes into spherical contact with the pressing force adjusting plate 25, and the pressing spring force is applied to the gear meshing portion 29 via the intermediate member 30 → the pressing force adjusting plate 25 → the gear back surface portion 23b. To give to.

  The pressing force adjusting plate 25 is a pressing force adjusting member that is fixed to the back surface position of the inconstant speed face gear 23 and changes the pressing spring force by the pressing spring 24 in accordance with the rotational phase of the inconstant speed face gear 23. The pressing force adjusting plate 25 sets the pressing spring force by changing the plate height in the kingpin axis direction according to the rotation phase. For example, in the case of the rotational phase A shown in FIG. 2, the plate height in the kingpin axis direction is lowered and the pressing spring force is set low. On the other hand, in the case of the rotational phase B shown in FIG. 3, the plate height in the kingpin axis direction is increased and the pressing spring force is set high.

The detailed configuration of the non-constant speed face gear 23 will be described with reference to FIGS. When the automobile is steered, it is desirable that the turning angle of the turning inner wheel is larger than that of the turning outer wheel. To cope with this, as shown in FIG. 4, the shape of the gear tooth portion 23a of the non-constant speed face gear 23 and the tooth position in the radial direction (inner end to outer end) are changed according to the rotation phase. That is, in the region of the rotational phase A where the gear tooth portion 23a is on the outer end side, the tooth shape is formed with a small pressure angle α as shown in FIG. On the other hand, in the region of the rotational phase B where the gear tooth portion 23a is on the inner end side, as shown in FIG.
Thereby, even if the rotation angular velocity of the same pinion gear part 22a is used, the rotation angular velocity of the inconstant speed face gear 23 continuously changes (variable gear ratio). However, since the position of the gear meshing portion 29 of the inconstant speed face gear 23 is located away from the shaft center (kingpin axis Kp), the inconstant speed face gear 23 is under load when a force acts on the gear meshing portion 29. A moment is generated that tries to knock down the kingpin axis Kp.

FIG. 7 shows an example of the relationship between the tangential force Ft acting on the inconstant velocity face gear 23 and the radial force Fr and the relationship between the pressure angle α depending on the rotation phase (face gear rotation angle). In the region of the rotational phase A of the inconstant speed face gear 23 (for example, the face gear rotational angle is 0 ° to 60 °), the pressure angle α is small, whereas the region of the rotational phase B of the inconstant speed face gear 23 ( For example, when the face gear rotation angle is 0 ° to -60 °, the pressure angle α is larger than the rotation phase A. And the relationship between tangential force Ft, radial force Fr and pressure angle α is
Fr ＝ Ft × tanα (1)
It becomes.
For this reason, the radial force Fr with respect to the tangential force Ft varies depending on the rotational phase (pressure angle α). Since this radial force Fr causes the falling moment of the inconstant speed face gear 23, a pressing force for canceling this is required. On the other hand, the pressing force adjusting plate 25 changes the pressing spring force in accordance with the change in the meshing tangential force Ft applied to the tooth surface of the inconstant speed face gear 23 and the radial force Fr obtained by the pressure angle α. .

Next, the operation will be described.
The operation of the steering device for an in-wheel motor vehicle according to the first embodiment will be described by dividing it into “an effect of improving the rigidity play of the inconstant speed face gear” and “another characteristic operation”.

[Improvement in rigidity play performance of non-uniform speed face gear]
An automotive steering apparatus that is disposed on the axis of the kingpin shaft and includes a steering mechanism that turns the tire around the kingpin shaft by the rotation of the cross-axis gear is required to have high rigidity and no play. For this reason, it is desirable to apply a pressing force from the axial direction of the cross shaft gear in order to eliminate backlash of the cross shaft gear. However, since the gear meshing portion of the cross shaft gear is at a position shifted from the center of the shaft, a moment is generated in the cross shaft gear due to the load, and the gear falls. This deteriorates the rigidity play performance.

On the other hand, in the first embodiment, the pressing spring 24 that applies the pressing force in the direction of increasing the gear meshing force is disposed below the gear meshing portion 29 of the inconstant speed face gear 23.
Therefore, when the motor-driven steered wheel 1 is steered around the kingpin axis Kp, a gear meshing pressing force is applied by the pressing spring 24 disposed below the gear meshing portion 29 of the inconstant speed face gear 23. As a result, the inconstant speed face gear 23 rotates.
That is, when a meshing load is generated in the inconstant speed face gear 23 during turning or the like, the pressing force applied to the gear meshing portion 29 acts in a direction to reduce the gap between the gear tooth surfaces (backlash removal function). In addition, it acts in the direction of reducing the meshing load, that is, in the direction of canceling the generation of moment. As a result, it is possible to improve the meshing rigidity backlash performance of the inconstant speed face gear 23 by suppressing the shaft tilt of the inconstant speed face gear 23 due to the generation of moment.

[Other features]
As described above, when a pressing force is applied to the gear meshing portion of the cross shaft gear, the case where the pressing force is not changed despite the change in the tooth shape as in the inconstant speed face gear 23 is used as a comparative example. . In the case of this comparative example, if the pressing force is set in accordance with the rotational phase that requires the largest pressing force, a transient pressing force is generated at other rotational phases, and the friction increases. On the other hand, if the pressing force is set in accordance with the rotation phase that requires the smallest pressing force, the pressing force is insufficient at other rotation phases, and the rigidity play performance deteriorates.

On the other hand, in the first embodiment, the pressing force adjusting plate 25 that changes the pressing spring force by the pressing spring 24 according to the rotational phase of the inconstant speed face gear 23 whose tooth shape changes is arranged.
As a result, an optimal pressing spring force can be applied in response to the meshing radial force that changes due to the change in the tooth shape of the inconstant speed face gear 23. That is, the rotational phase B shown in FIG. 3 is larger than the rotational phase A shown in FIG. 2, and the pressure angle α is larger and the radial force Fr is larger. Therefore, the amount of spring contraction of the pressing spring 24 is larger. Thus, since the radial force Fr changes in proportion to tanα, it is desirable that the amount of spring contraction is also changed in proportion to tanα.
Therefore, at any rotational phase of the inconstant speed face gear 23 in which the tooth shape changes, an increase in friction and a deterioration in rigidity play are suppressed.

In the first embodiment, the pressing force adjusting plate 25 is a member that changes the pressing spring force in accordance with the change in the radial force Fr obtained by the meshing tangential force Ft applied to the tooth surface of the inconstant speed face gear 23 and the pressure angle α. The configuration.
That is, when the same pressing force is applied to the radial force Fr acting on the gear meshing portion 29 of the inconstant speed face gear 23 in the opposite direction, an effect of canceling the generation of the target moment can be obtained.
On the other hand, by changing the pressing spring force in accordance with the change of the radial force Fr, it is possible to set a specific optimum value of the pressing spring force.

In the first embodiment, the pressing force adjusting plate 25 is configured to set the pressing spring force by changing the plate height in the kingpin axis direction according to the rotation phase.
That is, only by changing the plate height of the pressing force adjusting plate 25 in the kingpin axis direction, the pressing spring force changes depending on the rotation phase.
Therefore, since no new parts are required for changing the pressing spring force according to the rotational phase, an increase in cost can be suppressed.

Next, the effect will be described.
In the steering device for an in-wheel motor vehicle according to the first embodiment, the effects listed below can be obtained.

(1) A turning mechanism S1 disposed on the axis of the kingpin axis Kp and turning the tire (motor-driven steered wheels 1) around the kingpin axis Kp by the rotation of the cross axis gear (the inconstant speed face gear 23). In the vehicle steering device (in-wheel motor vehicle steering device) provided,
A pressing member (pressing spring 24) for applying a pressing force in a direction to increase the gear meshing force is disposed below the gear meshing portion 29 of the cross shaft gear (non-constant speed face gear 23) (FIG. 2).
For this reason, the meshing rigidity play of the cross shaft gear (non-constant speed face gear 23) can be improved.

(2) The pressing member is constituted by a spring member (pressing spring 24) that applies a pressing spring force to the gear meshing portion 29 of the cross shaft gear (non-constant speed face gear 23) (FIG. 2).
For this reason, in addition to the effect of (1), since the pressing member is configured by the spring member (the pressing spring 24), a simple and inexpensive pressing mechanism can be configured.

(3) The cross shaft gear is rotated by meshing with a pinion gear (pinion gear portion 22a) rotated by turning input, and an inconstant speed face gear 23 whose tooth shape is changed by a rotation phase,
A pressing force adjusting member (pressing force adjusting plate 25) that changes the pressing spring force by the spring member (pressing spring 24) according to the rotational phase of the inconstant speed face gear 23 is arranged (FIG. 3).
For this reason, in addition to the effect (2), it is possible to suppress an increase in friction and a deterioration in rigidity play performance at any rotational phase of the inconstant speed face gear 23 whose tooth shape changes.

(4) The pressing force adjusting member (pressing force adjusting plate 25) is pressed against the change of the radial force Fr obtained by the meshing tangential force Ft applied to the tooth surface of the inconstant speed face gear 23 and the pressure angle α. It was set as the member to change (FIG. 7).
For this reason, in addition to the effect of (1), a specific optimum value of the pressing spring force can be set by changing the pressing spring force according to the change of the radial force Fr.

(5) The pressing force adjusting member is a pressing force adjusting plate 25 fixed at the back position of the inconstant speed face gear 23,
The pressing force adjusting plate 25 sets the pressing spring force by changing the plate height in the kingpin axis direction according to the rotation phase (FIG. 2).
For this reason, in addition to the effect of (1), when changing the pressing spring force according to the rotation phase, no new parts are required, so that an increase in cost can be suppressed.

  The second embodiment is an example in which two spring members are arranged at two positions in the radial direction of the inconstant speed face gear.

First, the configuration will be described.
FIG. 8 shows a steering mechanism S2 in the steering device for an in-wheel motor vehicle of the second embodiment. Hereinafter, based on FIG. 8, the detailed structure of steering mechanism S2 of Example 2 is demonstrated.

  As shown in FIG. 8, the steering mechanism S2 includes a gear case 21, a pinion gear shaft 22, an inconstant speed face gear 23 (crossed shaft gear), a first spring 24a (first spring member), a second A spring 24b (second spring member) and a pressing force adjusting plate 25 (pressing force adjusting member) are provided. As in the first embodiment, the steering mechanism S2 is disposed at an upper position on the axis of the kingpin axis Kp, and the motor-driven steered wheels 1 are steered around the kingpin axis Kp by the rotation of the inconstant speed face gear 23. Let

  As shown in FIG. 8, the first spring 24 a and the second spring 24 b are two positions in the radial direction of the inconstant speed face gear 23, and are gear teeth formed on the inconstant speed face gear 23. They are arranged at the inner diameter side position and the outer diameter side position from the range of the radial position change of 23a. The first spring 24 a and the second spring 24 b include a first intermediate member 30 a and a second intermediate member 30 b that are in spherical contact with the pressing force adjusting plate 25. The pressing spring force from two points is applied to the gear meshing portion 29 via the intermediate members 30a and 30b → the pressing force adjusting plate 25 → the gear back surface portion 23b. Since the overall configuration and other configurations are the same as those in the first embodiment, illustration and description thereof are omitted.

Next, the operation will be described. In the second embodiment, the two first springs 24a and the second springs 24b are located outside the range of the radial position (inner end to outer end) of the gear tooth portion 23a that changes according to the rotation phase. It is set as the structure which arranges.
Therefore, when the gear meshing portion 29 is supported in the kingpin axial direction, the two-point support structure is adopted, so that the meshing inclination of the gear meshing portion 29 is suppressed and the axial support is stabilized.
Therefore, even if the radial position of the gear tooth portion 23a of the inconstant speed face gear 23 is changed, the shaft falling moment of the inconstant speed face gear 23 is stably canceled. Since other operations are the same as those of the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the steering device for an in-wheel motor vehicle according to the second embodiment, the following effects can be obtained.

(6) As a spring member, a first spring 24a and a second spring 24b arranged at two positions in the radial direction of the inconstant speed face gear 23 are provided.
The first spring 24a and the second spring 24b are arranged at an inner diameter side position and an outer diameter side position from the range of radial position change of the teeth (gear tooth portion 23a) formed on the inconstant speed face gear 23, respectively. (FIG. 8).
For this reason, in addition to the effects (1) to (5), even if the radial position of the tooth (gear portion 23a) of the inconstant speed face gear 23 changes, the shaft falling moment of the inconstant speed face gear 23 is stabilized. And can be canceled.

  Example 3 is an example in which a spring group provided at a plurality of locations along the circumferential direction of the inconstant speed face gear is provided as a spring member.

First, the configuration will be described.
FIGS. 9-12 shows the steering mechanism S3 in the steering apparatus for in-wheel motor vehicles of Example 3. FIG. Hereinafter, based on FIGS. 9-12, the detailed structure of steering mechanism S3 of Example 3 is demonstrated.

  As shown in FIGS. 9 to 12, the steering mechanism S3 includes a gear case 21, a pinion gear shaft 22, a non-constant speed face gear 23 (crossed shaft gear), and spring groups 24-1 to 24-5 (springs). Member) and a pressing force adjusting plate 25 ′ (pressing force adjusting member). Similar to the first embodiment, the steering mechanism S3 is disposed at an upper position on the axis of the kingpin axis Kp, and the motor-driven steered wheels 1 are steered around the kingpin axis Kp by the rotation of the inconstant speed face gear 23. Let

  The spring groups 24-1 to 24-5 are provided in the embedded state at five locations along the circumferential direction of the inconstant speed face gear 23, and each spring constant of the spring groups 24-1 to 24-5 is rotated. It is made different by changing the coil wire diameter so that the pressing spring force changes according to the phase. The spring groups 24-1 to 24-5 have intermediate members 30-1 to 30-5 that are in spherical contact with the pressing force adjusting plate 25 'fixed to the case, respectively. The pressing spring force is applied to the gear meshing portion 29 via the pressing force adjusting plate 25 '→ the intermediate members 30-1 to 30-5 → the gear back surface portion 23b. As shown in FIGS. 10 and 11, the arrangement of the springs of the spring groups 24-1 to 24-5 is based on the radial change in the position of the gear tooth portion 23 a formed on the inconstant speed face gear 23. It is changing together.

  As shown in FIG. 9, the pressing force adjusting plate 25 ′ is fixed to the gear support case portion 21 a (steering mechanism case) of the gear case 21, and is arranged at the back position of the inconstant speed face gear 23. As shown in FIG. 12, the pressing force adjusting plate 25 'has a plate height so that the pressing spring force increases in the vicinity of the meshing position (arrow E), and the pressing spring force decreases as it moves away from the meshing position due to rotation. It is set. Since the overall configuration and other configurations are the same as those in the first embodiment, illustration and description thereof are omitted.

Next, the operation will be described.
The spring groups 24-1 to 24-5 and the intermediate members 30-1 to 30-5 are embedded in the inconstant speed face gear 23 and rotate together with the inconstant speed face gear 23. At this time, different spring constants are set for each of the spring groups 24-1 to 24-5 according to the pressing force required for each rotation phase. The radial positions of the spring groups 24-1 to 24-5 are changed according to the position of the gear tooth portion 23 a of the non-constant speed face gear 23. Therefore, when the inconstant speed face gear 23 is rotated by substantially matching the axial positions of the gear teeth 23a of the inconstant speed face gear 23 and the spring groups 24-1 to 24-5, the axial collapse moment is canceled. can do.

  In the third embodiment, a pressing force adjusting plate 25 ′ for fixing the case is provided. The thickness of the pressing force adjusting plate 25 ′ is set so that the spring is contracted most in the vicinity of the meshing position of the inconstant speed face gear 23, and is set so as to decrease as the distance from the meshing position increases. As a result, a pressing spring force is generated in the vicinity of the meshing position, and the spring returns to the free length as the distance from the meshing position increases, so that the pressing spring force does not work.

  Furthermore, in the third embodiment, since the spring groups 24-1 to 24-5 rotate together with the inconstant speed face gear 23, the pressing spring force acts only in the vicinity of the meshing position to suppress the shaft collapse and move away from the meshing position. It does not work in any position. For this reason, an unintended shaft collapse moment does not occur. Since other operations are the same as those of the first embodiment, description thereof is omitted.

Next, the effect will be described.
In the steering apparatus for an in-wheel motor vehicle according to the third embodiment, the following effects can be obtained.

(7) As spring members, spring groups 24-1 to 24-5 provided at a plurality of locations along the circumferential direction of the inconstant speed face gear 23 are provided.
The spring constants of the spring groups 24-1 to 24-5 were varied so that the pressing spring force changed according to the rotation phase (FIG. 9).
For this reason, in addition to the effects (1) to (4), the spring groups 24-1 to 24-5 can be embedded in the inconstant speed face gear 23, thereby reducing the axial dimension of the steering mechanism S3. Miniaturization can be achieved.

(8) The arrangement of the springs of the spring groups 24-1 to 24-5 is changed in accordance with the radial change in the position of the tooth (gear tooth portion 23a) formed on the inconstant speed face gear 23 (see FIG. 10, FIG. 11).
For this reason, in addition to the effect of (7), the position where the pressing spring force is generated can be set in accordance with the gear meshing portion 29, so that the shaft collapse can be effectively suppressed.

(9) The pressing force adjusting member is a pressing force adjusting plate 25 ′ fixed to the steering mechanism case (gear support case portion 21a) and arranged at the back position of the non-constant speed face gear 23.
The pressing force adjusting plate 25 ′ has a plate height set so that the pressing spring force increases near the meshing position, and the pressing spring force decreases as it moves away from the meshing position by rotation (FIG. 12).
For this reason, in addition to the effect of (8), since an unintended shaft tilting moment does not occur, shaft tilting can be stably suppressed against rotation of the inconstant speed face gear 23.

  As mentioned above, although the vehicle steering apparatus of this invention has been demonstrated based on Example 1-3, it is not restricted to these Examples about a concrete structure, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention.

  In the first and second embodiments, the inconstant speed face gear 23 and the pressing force adjusting plate 25 are shown as separate parts. However, the inconstant speed face gear and the pressing force adjustment plate may be configured as one part.

  In the third embodiment, the gear case 21 (gear support case portion 21a) and the pressing force adjusting plate 25 'are shown as separate parts. However, the gear case and the pressing force adjustment plate may be configured as one part.

  In the first to third embodiments, the example in which the spring member (the pressing spring 24, the first spring 24a, the second spring 24b, and the spring groups 24-1 to 24-5) is used as the pressing member has been described. However, as the pressing member, an elastic member made of rubber or the like, a composite member of an elastic member and a spring member, or the like may be used as long as it can apply a pressing force to the gear meshing portion.

  In the first to third embodiments, an example is shown of an inconstant speed face gear that rotates by meshing with a pinion gear that rotates by turning input, and whose tooth shape is changed according to the rotation phase, as the cross shaft gear. However, the cross shaft gear may be a constant speed face gear whose tooth shape is constant regardless of the rotational phase.

  In Examples 1-3, the example which applies the steering device for vehicles of the present invention to an in-wheel motor vehicle was shown. However, the vehicle steering device of the present invention is not limited to an in-wheel motor vehicle, and can be applied as a steering device for other vehicles such as an engine vehicle, a hybrid vehicle, and an electric vehicle. In short, it can be applied to any vehicle steering device that is disposed on the axis of the kingpin shaft and includes a steering mechanism that turns the tire around the kingpin shaft by the rotation of the cross shaft gear.

S1, S2, S3 Steering mechanism 1 Motor-driven steered wheels (tires)
21 gear case 22 pinion gear shaft 23 non-constant speed face gear (crossed shaft gear)
24 Pressing spring (pressing member)
24a First spring (spring member)
24b Second spring (spring member)
24-1 to 24-5 Spring group (spring member)
25 Pressing force adjusting plate (pressing force adjusting member)
25 'pressing force adjusting plate (pressing force adjusting member)
Kp Kingpin shaft

Claims (7)

In a vehicle steering apparatus provided with a steering mechanism that is arranged on the axis of a kingpin shaft and steers a tire around the kingpin shaft by rotation of a cross axis gear,
A spring member that applies a spring force to the gear meshing portion of the cross shaft gear is disposed below the gear meshing portion of the cross shaft gear.
The cross shaft gear is rotated by meshing with a pinion gear that is rotated by a turning input, and an inconstant speed face gear whose tooth shape is changed by a rotation phase,
A vehicle steering apparatus comprising a pressing force adjusting member that changes a pressing spring force of the spring member in accordance with a rotation phase of the inconstant speed face gear . The vehicle steering apparatus according to claim 1 ,
The vehicle steering system, wherein the pressing force adjusting member is a member that changes a pressing spring force in accordance with a change in a radial force obtained by a meshing tangential force and a pressure angle applied to a tooth surface of the inconstant speed face gear. apparatus. In the vehicle steering device according to claim 2 ,
The pressing force adjusting member is a pressing force adjusting plate fixed at the back position of the inconstant speed face gear,
The vehicle steering apparatus, wherein the pressing force adjusting plate sets a pressing spring force by changing a plate height in a kingpin axis direction according to a rotation phase. In a vehicle steering apparatus provided with a steering mechanism that is arranged on the axis of a kingpin shaft and steers a tire around the kingpin shaft by rotation of a cross axis gear,
A spring member that applies a spring force to the gear meshing portion of the cross shaft gear is disposed below the gear meshing portion of the cross shaft gear.
The cross shaft gear is rotated by meshing with a pinion gear that is rotated by a turning input, and an inconstant speed face gear whose tooth shape is changed by a rotation phase,
The spring member includes a first spring and a second spring arranged at two positions in the radial direction of the inconstant speed face gear,
The first spring and the second spring are respectively disposed at an inner diameter side position and an outer diameter side position with respect to a range of a radial position change of teeth formed on the inconstant speed face gear. Steering device. In a vehicle steering apparatus provided with a steering mechanism that is arranged on the axis of a kingpin shaft and steers a tire around the kingpin shaft by rotation of a cross axis gear,
A spring member that applies a spring force to the gear meshing portion of the cross shaft gear is disposed below the gear meshing portion of the cross shaft gear.
The cross shaft gear is rotated by meshing with a pinion gear that is rotated by a turning input, and an inconstant speed face gear whose tooth shape is changed by a rotation phase,
As the spring member, comprising a group of springs provided at a plurality of locations along the circumferential direction of the inconstant speed face gear,
The vehicle steering apparatus according to claim 1, wherein each spring constant of the spring group is changed so that a pressing spring force changes according to a rotation phase. In the vehicle steering device according to claim 5 ,
The vehicular steering apparatus, wherein the arrangement of the springs of the spring group is changed in accordance with a radial change in the position of teeth formed on the inconstant speed face gear. The vehicle steering device according to claim 6 ,
The pressing force adjusting member is fixed to a steering mechanism case, and is a pressing force adjusting plate disposed at a back position of the inconstant speed face gear,
The vehicle steering apparatus according to claim 1, wherein the pressing force adjusting plate has a plate height set so that a pressing spring force is increased in the vicinity of the meshing position, and the pressing spring force is decreased as it is moved away from the meshing position by rotation.