JP6507864B2 - In-wheel type suspension device - Google Patents

Description

  The present invention relates to an in-wheel suspension system in which at least a portion of the suspension components are disposed in a wheel on which a tire is mounted.

  Conventionally, a wheel supporting member having one sliding shaft is provided on a tire, and a suspension member attached to a vehicle body is slidably connected to the sliding shaft, and between the wheel supporting member and the suspension member An in-wheel type suspension device having an elastic element disposed therein is known (see, for example, Patent Document 1).

Patent No. 4305429

By the way, although the ground contact reaction force which acts when the tire comes into contact with the ground is generated upward from the contact point of the tire, the acting direction (ground reaction force line) of the ground reaction force at this time passes through the wheel center. In addition, when the elastic element is deformed with the contact of the tire, the acting direction (spring reaction line) of the spring reaction force at this time is along the deformation direction of the elastic element.
Here, in the conventional in-wheel type suspension device, the upper end portion of the elastic element is inclined rearward of the vehicle. That is, the deformation direction of the elastic element is set in the direction toward the diagonal rear from the tire contact point.
Therefore, when the suspension member strokes in the vertical direction, the spring reaction force line is directed obliquely backward from the tire contact point with respect to the ground contact reaction line generated upward from the tire contact point, and The spring reaction line is in a completely different direction. Therefore, at the wheel center height, the position where the ground contact reaction force passes and the position where the spring reaction force line passes are largely separated, and this positional deviation causes a problem that a twisting moment acts on the sliding shaft. It was

  The present invention has been made in view of the above problems, and it is possible to reduce the friction (sliding resistance) by suppressing the twisting moment acting on the sliding shaft when the suspension member strokes in the vertical direction. An object of the present invention is to provide a wheel type suspension system.

In order to achieve the above object, the in-wheel type suspension device of the present invention has a suspension member whose one end is connected to a wheel supporting member provided on a wheel on which a tire is mounted and whose other end is elastically supported on a vehicle body At least a portion of the suspension component is disposed within the wheel.
In this in-wheel type suspension device, the suspension member is slidably coupled to at least one sliding shaft provided on the wheel support member, and an elastic element is provided between the wheel support member and the suspension member. Deploy. Moreover, it has a 1st sliding shaft part and a 2nd sliding shaft part as a sliding shaft. And this elastic element is comprised by the 1st elastic member arrange | positioned in the vehicle front side position rather than a wheel center, and the 2nd elastic member arrange | positioned in a vehicle rear side position rather than a wheel center. Further, the first sliding shaft portion is disposed between the first elastic member and the second elastic member, and is disposed closer to the wheel center than the second sliding shaft portion.
Further, in the in-hole type suspension device, the suspension member is slidably coupled to at least one sliding shaft provided on the wheel support member, and elastic between the wheel support member and the suspension member Arrange the elements. Also, as the sliding shaft, there are provided a first sliding shaft portion and a second sliding shaft portion arranged in the longitudinal direction of the vehicle. And this elastic element is comprised by the 1st elastic member arrange | positioned in the vehicle front side position rather than a wheel center, and the 2nd elastic member arrange | positioned in a vehicle rear side position rather than a wheel center. Furthermore, the first sliding shaft portion is disposed between the first elastic member and the second elastic member, and the second sliding shaft portion is disposed at a vehicle front position relative to the first elastic member.
Furthermore, in the in-hole type suspension device, the suspension member is slidably coupled to at least one sliding shaft provided on the wheel support member, and elastic between the wheel support member and the suspension member Arrange the elements. Also, as the sliding shaft, there are provided a first sliding shaft portion and a second sliding shaft portion arranged in the longitudinal direction of the vehicle. And this elastic element is comprised by the 1st elastic member arrange | positioned in the vehicle front side position rather than a wheel center, and the 2nd elastic member arrange | positioned in a vehicle rear side position rather than a wheel center. Furthermore, at least one of the connection portion of the suspension member and the first slide shaft portion and the connection portion of the suspension member and the second slide shaft portion has a displacement absorbing mechanism that absorbs the shift displacement of the slide shaft.

Therefore, since the elastic element has the first elastic member disposed at the vehicle front side position than the wheel center and the second elastic member disposed at the vehicle rear side position than the wheel center, the two elastic members are provided. It is arranged across the wheel center. As a result, the spring reaction force generated when the tire is in contact with the wheel is dispersed and acts across the wheel center, and the action line (spring reaction line) of the average spring reaction force passes through the center. On the other hand, although the tire ground contact reaction force occurs upward from the tire ground contact point, the line of action of the ground contact reaction force at this time (ground contact reaction line) passes through the wheel center.
As a result, an average spring reaction line and a ground reaction line can be brought close to each other, and a displacement moment can be suppressed by acting on the sliding shaft, and friction can be reduced.

FIG. 2 is an overall perspective view of a left rear wheel to which the in-wheel type suspension device of Embodiment 1 is applied, as viewed obliquely from the rear inside of the vehicle. FIG. 2 is a perspective view showing suspension components of the in-wheel type suspension system of the first embodiment. FIG. 6 is a schematic view of the arrangement of suspension components in the in-wheel suspension system of the first embodiment when viewed from the inside of the vehicle. FIG. 3 is a schematic view of the arrangement of suspension components in the in-wheel type suspension system of the first embodiment when viewed from above the vehicle. FIG. 6 is a cross-sectional view showing the structure of the connection portion between the suspension member and the sliding shaft in the in-wheel type suspension system of the first embodiment. FIG. 7 is a cross-sectional view of the in-wheel type suspension device of the first embodiment when the positional relationship between the attachment of the main sliding shaft and the auxiliary sliding shaft and the tire is viewed from the rear of the vehicle. It is explanatory drawing which shows the earthing | grounding reaction force line | wire which acts on the in-hole type suspension apparatus of a comparative example, a spring reaction force line, and pricking moment. FIG. 14 is an explanatory view showing a ground contact reaction force line and a spring reaction force line that act on the in-wheel type suspension device of the first modified example of the first embodiment. FIG. 14 is an explanatory view showing a ground contact reaction force line and a spring reaction force line acting on the in-wheel type suspension device of the second modified example of the first embodiment. FIG. 18 is an explanatory view showing a ground contact reaction force line and a spring reaction force line acting on the in-wheel type suspension device of the third modified example of the first embodiment. It is a graph which shows the size of the prying moment which arises in the position which each spring reaction force line passes in the wheel center height in Drawing 7A-Drawing 7C. It is explanatory drawing which shows the positional relationship of a spring reaction force line and a sliding shaft. FIG. 7 is an explanatory view showing a ground contact reaction force line and a spring reaction force line acting on the in-wheel type suspension device of the first embodiment. In an in-wheel type suspension device, it is slide axis modification operation explanatory view showing a modification state of a slide axis when ground contact load is inputted. In an in-wheel type suspension device, it is slide axis modification operation explanatory view showing a modification state of a slide axis when tire lateral force is inputted. In an in-wheel type suspension device, it is slide axis modification operation explanatory view showing a modification state of a slide axis when braking force is inputted. In an in-wheel type suspension device, it is slide axis modification operation explanatory view showing a modification state of a slide axis when front and back force is inputted. In an in-wheel type suspension device, it is modification state explanatory view showing a sliding axis when a shaft inclination gap arises. In an in-wheel type suspension device, it is modification state explanatory view showing a sliding axis when distance gap between axes has arisen. In an in-wheel type suspension device, it is an explanatory view showing the increase mechanism of sliding resistance by axis inclination shift. In an in-wheel type suspension device, it is an explanatory view showing the increase mechanism of sliding resistance by gap gap between axes. FIG. 7 is an explanatory view showing a state change of the auxiliary sliding shaft when an axial inclination deviation occurs in the in-wheel type suspension device of the first embodiment. FIG. 14 is a cross-sectional view showing a structure (slide structure) of a connection portion of a suspension member and an auxiliary sliding shaft in the in-wheel type suspension device of Example 2. It is a perspective view which shows the slide structure shown in FIG. FIG. 16 is a cross-sectional view showing a structure (relative rotation structure) of a connection portion of a suspension member and an auxiliary sliding shaft in the in-wheel type suspension device of Example 3. FIG. 16 is an explanatory view showing a state change of the auxiliary sliding shaft when an axial inclination deviation occurs in the in-wheel type suspension device of the third embodiment. FIG. 18 is a cross-sectional view showing a structure (slide structure + relative rotation structure) of a connection portion of a suspension member and an auxiliary sliding shaft in the in-wheel type suspension system of Example 4; FIG. 18 is an explanatory view showing an arrangement structure of a bearing portion in the in-wheel type suspension device of Example 4; FIG. 18 is a schematic view showing the arrangement of suspension components in the in-wheel suspension system of the fourth modification of the first embodiment. FIG. 21 is a schematic view showing the arrangement of suspension components in the in-wheel suspension system of the fifth modification of the first embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments for carrying out the in-wheel type suspension device of the present invention will be described based on Examples 1 to 4 shown in the drawings.

Example 1
First, the configuration will be described.
The configuration of the in-wheel type suspension device in the first embodiment will be described by dividing it into "whole configuration", "detailed configuration of elastic element", and "connection configuration of suspension member and sliding shaft".

[overall structure]
FIG. 1 is a perspective view of a left rear wheel (following wheel) to which the in-wheel type suspension device of the first embodiment is applied, as viewed obliquely from the rear inside of a vehicle, and FIG. 2 shows suspension components. Hereinafter, the entire configuration will be described based on FIGS. 1 and 2. In FIG. 1, the right side is the front of the vehicle.

As shown in FIG. 1, the in-wheel type suspension device IWS 1 includes a wheel support member 1, a suspension member 2, a sliding shaft 3, a tire 4, an elastic element 5, an elastic bush 6, and a wheel center 7. , A vehicle mounting member 8, a wheel 9, and a damping element 10.
Here, the reason that the suspension device is not simply a suspension device but an "in-wheel type suspension device" is that at least a part of the suspension components is disposed in the wheel 9 on which the tire 4 is mounted.

The wheel support member 1 is constituted by a knuckle plate provided in the inner space of the wheel 9 to which the tire 4 is attached, and has a main plate 1a, an upper plate 1b and a lower plate 1c (see FIG. 2). Here, the main plate 1 a is fixed to the wheel 9 at the wheel center 7. The upper plate 1b extends from the upper end of the main plate 1a to the vehicle inner side, and the lower plate 1c extends from the lower end of the main plate 1a to the vehicle inner side.
On the upper plate 1b of the wheel support member 1, as shown in FIG. 2, upper end portions of the main sliding shaft 3a and the auxiliary sliding shaft 3b in parallel arrangement constituting the sliding shaft 3 are fixed, and the lower plate The upper end portions of the main sliding shaft 3a and the auxiliary sliding shaft 3b are fixed to 1c.

The suspension member 2 is a suspension component having one end connected to the wheel support member 1 and the other end elastically supported by the vehicle body. As shown in FIG. 1, the suspension member 2 includes a front side vehicle support bracket 2a, a rear side vehicle support bracket 2b, a main slide bearing pipe 2c, an elastic element support bracket 2d, and a sub slide bearing pipe 2e. , Integrally.
The main sliding bearing pipe 2 c is a wheel connecting portion of the suspension member 2 and is slidably connected to the main sliding shaft 3 a fixed to the wheel supporting member 1. Further, the auxiliary sliding bearing pipe 2 e is a wheel connecting portion of the suspension member 2 and is slidably connected to the auxiliary sliding shaft 3 b fixed to the wheel supporting member 1. That is, the wheel support member 1 and the suspension member 2 are connected via the sliding shaft 3.
On the other hand, front side vehicle support bracket 2a and rear side vehicle support bracket 2b are arranged side by side in the longitudinal direction of the vehicle, and both extend from the main sliding bearing pipe 2c toward the inner side of the vehicle, and the end portion on the vehicle side An elastic bush 6 is provided on the Further, a sub slide bearing pipe 2e is connected to the front side vehicle support bracket 2a. Further, the elastic element support bracket 2d is formed so as to protrude in the vehicle longitudinal direction from the upper end portion of the main sliding bearing pipe 2c.
That is, the suspension member 2 operates integrally as a whole, and is restricted to vertical movement along the main sliding shaft 3a and the auxiliary sliding shaft 3b as the freedom of movement.

  As shown in FIG. 2, the sliding shaft 3 has its upper end and lower end fixed to the wheel support member 1, and is a main slide vertically arranged between the upper plate 1 b and the lower plate 1 c in parallel with each other. It is comprised by the dynamic shaft 3a (1st sliding shaft part) and the sub sliding shaft 3b (2nd sliding shaft part). Here, the main sliding shaft 3a and the sub sliding shaft 3b are arranged side by side in the vehicle longitudinal direction across the wheel center 7, and the main sliding shaft 3a is at the vehicle rear position than the wheel center 7. It is arranged. Furthermore, the main sliding shaft 3a has a diameter larger than that of the sub sliding shaft 3b.

  The elastic element 5 is a coil spring interposed between the elastic element support bracket 2 d of the suspension member 2 and the lower plate 1 c of the wheel support member 1. The elastic element 5 elastically supports the suspension member 2 by applying a spring biasing force to the vertical sliding motion of the suspension member 2.

The elastic bush 6 is a cylindrical bush provided between the front side vehicle support bracket 2 a and the rear side vehicle support bracket 2 b of the suspension member 2 and the vehicle body attachment member 8. Here, it has first and second elastic bushes 6a and 6b attached to the front side vehicle body support bracket 2a and a third elastic bush 6c attached to the rear side vehicle body support bracket 2b.
The first elastic bush 6 a is disposed above the wheel center 7, and the second and third elastic bushes 6 b and 6 c are disposed below the wheel center 7.

  The vehicle body mounting member 8 is, as shown in FIG. 1, a vehicle body side plate for attaching the upper end portions of the first to third elastic bushes 6a, 6b, 6c of the suspension member 2 and the damping element 10 to the vehicle body. It is a member. That is, the suspension member 2 and the vehicle body are connected via the elastic bush 6 and the vehicle body attachment member 8.

  The damping element 10 is, as shown in FIG. 1, fixed at its lower end to the lower plate 1c of the wheel support member 1 and attached at its upper end to the vehicle mounting member 8, and is constituted by a so-called shock absorber. The damping element 10 attenuates the force transmitted to the vehicle body when the tire 4 travels up and down.

[Detailed configuration of elastic element]
FIG. 3A is a schematic view when the arrangement of the suspension components of the first embodiment is viewed from the inside of the vehicle, and FIG. 3B is a schematic view when viewed from above the vehicle. Hereinafter, based on FIG. 3A and FIG. 3B, the detailed structure of an elastic element is demonstrated.

  The said elastic element 5 has the 1st spring 51 (1st elastic member) and the 2nd spring 52 (2nd elastic member), as shown to FIG. 2 and FIG. 3A. Each of the first spring 51 and the second spring 52 is a coil-shaped compression spring which is formed of metal and is set to have the same natural length.

Here, the elastic element support bracket 2d for supporting the elastic element 5 is extended in the vehicle longitudinal direction from the main slide bearing pipe 2c connected to the main slide shaft 3a, and extends toward the vehicle front One end extends to the vehicle front position relative to the wheel center 7 and to the vehicle rear position relative to the sub slide shaft 3b.
Therefore, when the vehicle is viewed from the side, the first and second springs 51 and 52 are arranged side by side in the vehicle longitudinal direction across the main sliding shaft 3a. The first spring 51 is located on the vehicle front side relative to the wheel center 7 and is disposed on the vehicle rear side relative to the secondary sliding shaft 3b, that is, between the wheel center 7 and the secondary sliding shaft 3b. The second spring 52 is disposed at the vehicle rear side position than the wheel center 7. As a result, as shown in FIG. 3B, the auxiliary sliding shaft 3b, the first spring 51, the wheel center 7, the main sliding shaft 3a, and the second spring 52 are arranged in this order from the vehicle front side.
The positions of the main sliding shaft 3a and the first and second springs 51 and 52 in the vehicle width direction coincide with each other, and the sub sliding shaft 3b is in the vehicle inner side than these.

  Further, the deformation direction (axial direction) of the first spring 51 and the deformation direction (axial direction) of the second spring 52 are both set parallel to the axial direction of the main sliding shaft 3a and the sub sliding shaft 3b. It is done. Further, the axial directions of the main sliding shaft 3a, the auxiliary sliding shaft 3b, and the first and second springs 51 and 52 are set in a direction orthogonal to the road surface when the vehicle is at rest.

Further, in Example 1, the ratio of the vehicle longitudinal distance L ₁ from the wheel center 7 to the first spring 51, and the vehicle longitudinal distance L ₂ from the wheel center 7 to the second spring 52, the first spring 51 the reciprocal of the spring constant K ₁ of which is set to match the ratio of the reciprocal of the spring constant K ₂ of the second spring 52. That is, the distances L ₁ and L ₂ and the spring constants K ₁ and K ₂ have a relationship in which the following equations (1) and (2) hold.
L ₁ : L ₂ = 1 / K ₁ : 1 / K ₂ (1)
K ₁ × L ₁ = K ₂ × L ₂ (2)

[Connection configuration of suspension member and sliding shaft]
FIG. 4 shows the structure of the connection portion between the suspension member and the sliding shaft in the in-wheel type suspension system of the first embodiment, and FIG. 5 shows the positional relationship between the attachment of the main sliding shaft and the secondary sliding shaft and the tire. Show it briefly. Hereinafter, based on FIG.4 and FIG.5, the connection structure of the suspension member of Example 1 and a sliding shaft is demonstrated.

  In the first embodiment, the slide shaft 3 has two main slide shafts 3a and a sub slide shaft 3b, and as shown in FIG. 5, when viewed from the rear of the vehicle, the main slide shaft 3a is a tire. The auxiliary sliding shaft 3b is set at a position closer to 4 and at a position farther from the tire 4 in which the input is smaller than that of the main sliding shaft 3a. That is, when there is a road surface input, the input through the tire 4 is different from the input of the main sliding shaft 3a and the auxiliary sliding shaft 3b so that the main sliding shaft 3a becomes larger than the auxiliary sliding shaft 3b. . For this reason, according to the input difference, the shaft diameter of the main sliding shaft 3a is made larger than the shaft diameter of the sub sliding shaft 3b.

And as shown in FIG. 4, only the slide bush 11 is interposed in the connection part of the main sliding bearing pipe 2c (wheel connection part) of the suspension member 2 and the main sliding shaft 3a. On the other hand, a sliding bush 11 and an elastic bush 12 (displacement absorbing mechanism) are sequentially interposed in the connection portion of the sub sliding bearing pipe 2e (wheel connecting portion) of the suspension member 2 and the sub sliding shaft 3b. ing.
That is, the connection configuration of the suspension member 2 and the sub slide shaft 3b is configured such that the slide bush 11 → the elastic body bush 12 → the sub slide bearing pipe 2e is provided coaxially in order from the axis center CL of the sub slide shaft 3b. And

  Here, the main slide bearing pipe 2 c and the sub slide bearing pipe 2 e are cylindrical pipes made of a metal material connected to the front side vehicle support bracket 2 a of the suspension member 2.

  The slide bush 11 is a slide bearing portion in contact with the shaft surface of the sub slide shaft 3b, and is formed of a cylindrical bush made of a resin material which promotes slip. The slide bush 11 provided at a position in contact with the surface of the main slide shaft 3a is also the same.

  The elastic body bush 12 is an elastically deformable cylindrical bush interposed between the sub slide bearing pipe 2 e and the slide bush 11. The elastic bush 12 is deformed when the axial directions of the auxiliary sliding bearing pipe 2e and the auxiliary sliding shaft 3b are shifted, so that the offset displacement between the auxiliary sliding bearing pipe 2e and the auxiliary sliding shaft 3b is determined. Absorb. The elastic body bush 12 is made of rubber or the like having high elastic deformation.

Next, the operation will be described.
First, in describing the operation of the first embodiment, background art and problems of the present invention will be described.
In recent years, expectations for electric vehicles have been increasing from the viewpoint of efficient use of energy resources. However, the range of the electric car is short for the user's expectation, and it is necessary to extend the range at full charge. And, in order to extend the cruising distance, mounting as many batteries as possible in a limited space is considered promising as one solution, and space saving of the suspension device becomes an important technical issue. There is.

And in the technical field of "space saving of a suspension device", the in-wheel type suspension device without a suspension link is known.
This in-wheel type suspension device includes a wheel support member for supporting a wheel, and a suspension member connected to the wheel support member and attached to a vehicle body, and at least a part of the suspension member is in the wheel of the wheel. Is located in
Furthermore, as such an in-wheel type suspension device, in order to make the wheel move up and down, the suspension member is slidably coupled to a sliding shaft provided on the wheel support member, and between the wheel support member and the suspension member Are considered to have an elastic element and / or a damping element.

Here, in the case of a suspension apparatus using a suspension link, although the space occupied by the suspension member can be reduced by shortening the length of the suspension link, the posture change (steer change or camber change) etc. caused by the vertical stroke of the wheel is large. turn into. That is, since a long suspension link is required to reduce the change in attitude of the wheel, the space occupied by the suspension device can not be reduced.
On the other hand, in the in-wheel type suspension device in which the suspension member is slidably connected to the sliding shaft of the wheel support member, the tire can move up and down along the sliding shaft. Moreover, space saving can be realized by arranging the elastic element so as to be inclined with respect to the sliding axis.

  However, in terms of the comfort of the vehicle, in particular the vibration of the vehicle, it is necessary not to transmit the impact force due to the uneven road surface to the vehicle body. For this purpose, it is necessary to smooth the relative vertical stroke between the suspension member and the sliding shaft to absorb road surface input. Also, in order to ensure vehicle stability during turning, when the vehicle is rolling, it is also necessary to prevent the inner tire from floating and to be in contact with the ground. For this purpose, it is also important to make the stroke smooth in the inner ring rebound (extension side) direction.

  In order to satisfy these requirements, it is necessary to reduce the friction (sliding resistance) when the suspension member and the sliding shaft relatively move up and down.

  On the other hand, in the in-wheel type suspension device as in the first embodiment, in order to make the suspension member and the sliding shaft relatively move up and down, the suspension member is connected so as to be vertically slidable with respect to the sliding shaft. Here, when a shift occurs between the action direction of the upward ground contact reaction force acting on the tire from the road surface and the action direction of the spring reaction force of the elastic element of the suspension member supporting the load when the vehicle is grounded, sliding occurs. A twisting moment (a moment acting in a direction to pry the axis of the sliding shaft) acts on the shaft. Then, this pricking moment acts on the sliding shaft, which causes a problem that friction between the suspension member and the sliding shaft at the time of vertical stroke increases.

Furthermore, in the case where a sliding mechanism using two sliding shafts is used to make the suspension member move up and down, the suspension members are connected to the sliding shaft at two points, and two connecting parts are It slides up and down along each of two sliding axes. For this reason, it is important to maintain the parallelism of these two sliding axes.
However, it is not easy to maintain the parallelism due to the processing accuracy and assembly accuracy of the suspension components. In addition, when a ground contact load, tire lateral force, braking force, etc. are applied, an external force that is squeezed around the wheel acts, so a squeezing moment acts on each sliding axis and the distance between the two axes is A change or bending of the sliding shaft may occur to cause a shift in the inclination angle between the two shafts.
And, as a result, there arises a problem that the friction at the time of the vertical stroke of the suspension member is increased. In the present invention, the change in the distance between the two axes and the change in the inclination angle are referred to as misalignment.

  Next, the operation of the in-wheel type suspension device of the first embodiment will be described by being divided into “pegment moment reduction operation”, “displacement absorption operation of sliding shaft”, and “other characteristic operation”.

[Making moment reduction action]
When the vehicle comes in contact with the road surface, a ground reaction force acting upward from the ground contact point is input to the tire. The action direction of the ground reaction force (ground reaction line) is perpendicular to the road surface (vertical direction) as shown in FIG. 6, and passes through the wheel center. On the other hand, the elastic element elastically supporting the suspension member generates a spring reaction force along the deformation direction. That is, the acting direction (spring reaction line) of the spring reaction force input to the suspension member is a direction along the deformation direction of the elastic element.
When the ground contact reaction force line and the spring reaction line are deviated, a moment according to the deviation amount is generated around the wheel center. This moment rotates the wheel supporting member around the axle, and twists the sliding shaft (mainly the main sliding shaft 3a in the first embodiment) supported from the vehicle body side via the suspension member (prying moment) Become.

  In the case where the elastic element 5 is constituted by two coil springs (first and second springs 51 and 52) aligned in the longitudinal direction of the vehicle with the main sliding shaft 3a interposed therebetween as in the first embodiment, a suspension is provided. The spring reaction force acting on the member 2 is an average spring reaction force of the spring reaction force generated by the first spring 51 and the spring reaction force generated by the second spring 52.

  Here, as shown in FIGS. 7A to 7C, depending on the setting direction of the two coil springs (first spring α and second spring β), the acting direction of the average spring reaction force (average spring reaction force line A ) Will be different. However, as compared with the spring reaction force line B of the spring reaction force generated by the first spring α and the spring reaction force line C of the spring reaction force generated by the second spring β, the average spring The position where the force line A passes is close to the position where the ground reaction force line X passes.

Therefore, as shown in FIG. 7D, regardless of the setting directions of the two coil springs, the absolute value of the prying moment generated by the average spring reaction force (the position a where the average spring reaction line A passes at the wheel center height) The magnitude of the pricking moment occurring in the first spring α is the absolute value of the pricking moment produced by the first spring α (the magnitude of the pricking moment occurring at the position b where the spring reaction line B passes at the wheel center height) This value is smaller than the absolute value of the twisting moment caused by (size of the twisting moment generated at the position c where the spring reaction line C passes at the wheel center height).
This is because the ground contact reaction force is input to the vehicle body support member via the wheel center. As a result, at the wheel center height when viewed from the side of the vehicle, as the positional deviation between the position where the spring reaction line passes and the position where the ground reaction line passes (wheel center position) decreases, the pricking moment Becomes smaller.

  Further, FIG. 8 is an explanatory view showing a positional relationship between a spring reaction line and a sliding shaft. From this FIG. 8, when there is an angular deviation between the direction of the axis of the sliding shaft (axial center CL) and the direction of the spring reaction line, the component force of the spring reaction force in the direction crossing the sliding shaft An axial direct reaction force is generated. The “axial forward direction reaction force” has an action of bending the sliding shaft, and becomes a friction factor when the suspension member 2 slides along the main sliding shaft 3 a.

  From the above, when the suspension member 2 travels in the vertical direction of the vehicle, in order to suppress the twisting moment acting on the sliding shaft 3 (particularly the main sliding shaft 3a here), the elastic element 5 elastically supporting the suspension member 2 It can be said that it is desirable that the spring reaction line generated by the above-mentioned is coincident with the ground reaction line at the height position of the wheel center 7. Furthermore, it can be said that this spring reaction line should be parallel to the axial direction of the sliding shaft.

  On the other hand, in the in-wheel type suspension system of the first embodiment, the elastic element 5 which is disposed between the wheel support member 1 and the suspension member 2 and elastically supports the suspension member 2 is at the vehicle front position than the wheel center 7 A first spring 51 is disposed, and a second spring 52 is disposed at a position on the vehicle rear side of the wheel center 7.

Therefore, as shown in FIG. 9, the spring reaction line generated when the tire 4 is in contact with the first spring reaction line 53 along the deformation direction of the first spring 51 and in the deformation direction of the second spring 52 The second spring reaction force line 54 along the line is dispersed in the vehicle longitudinal direction across the wheel center 7. Therefore, the acting direction (average spring reaction line 55) of the average spring reaction force of the spring reaction force along the first and second spring reaction lines 53, 54 passes near the wheel center 7. become.
On the other hand, the ground contact reaction force acting on the tire 4 is generated upward from the contact point 4 a of the tire 4, and the acting direction of the ground contact reaction force (ground ground reaction force line 56) passes through the wheel center 7.

  Thereby, the average spring reaction line 55 and the ground reaction line 56 can be brought close to each other at the wheel center height, and the deviation can be suppressed to a small value. Therefore, it is possible to suppress the bending moment acting on the main sliding shaft 3a. And, as a result of the pricking moment being suppressed, the friction (sliding resistance) when the suspension member 2 slides can be reduced.

[Misalignment absorption effect of sliding shaft]
First, in describing the misalignment absorbing action of the sliding shaft of Example 1, the input from the tire 4 and the deformation modes of the main sliding shaft 3a and the auxiliary sliding shaft 3b will be described using FIGS. Do.

FIG. 10 is a view showing a modified embodiment of the main sliding shaft 3a and the sub sliding shaft 3b when the ground contact load acts on the tire 4. As shown in FIG. The wheel support member 1 (knuckle) has a solid line position from the broken line position so that the lower side is inclined outward in the vehicle width direction by the vertical direction component (arrow in FIG. 10) of the ground contact force generated Transform into For this reason, bending moment M1 and bending moment M2 are applied to the main sliding shaft 3a and the sub sliding shaft 3b so that the upper end portions respectively enter the inside in the vehicle width direction and the lower end portions project outward in the vehicle width direction. .
On the other hand, the suspension member 2 is supported by the vehicle body mounting member 8 and is not affected by the ground contact load reaction force. Therefore, the displacement of the intermediate portion of each sliding shaft 3a, 3b is restricted by the main sliding bearing pipe 2c or the secondary sliding bearing pipe 2e of the suspension member 2, and the upper end is displaced inward of the vehicle body. Is displaced in the outward direction of the vehicle body and is in a state of being bent into an "S-shape".

FIG. 11 is a view showing a modified embodiment of the main sliding shaft 3a and the auxiliary sliding shaft 3b when the tire lateral force at the time of turning acts on the tire 4. As shown in FIG. The wheel support member 1 (knuckle) is deformed from the broken line position to the solid line position so that the lower side is inclined inward in the vehicle width direction by the vehicle width direction component of the tire lateral force (arrow in FIG. 11). Therefore, a bending moment M3 and a bending moment M4 are applied to the main sliding shaft 3a and the sub sliding shaft 3b so that the upper end portions respectively project outward in the vehicle width direction and the lower ends enter inside in the vehicle width direction. .
On the other hand, the suspension member 2 is not affected by the tire lateral force. For this reason, the displacement of the intermediate portion of each sliding shaft 3a, 3b is restricted by the main sliding bearing pipe 2c or the secondary sliding bearing pipe 2e of the suspension member 2, and the upper end is displaced in the outward direction of the vehicle body. The part is displaced in the inward direction of the vehicle body and is in a state of being bent in the "reverse S-shape".

FIG. 12 is a view showing a modified embodiment of the main sliding shaft 3a and the auxiliary sliding shaft 3b when the braking force acts on the tire 4. As shown in FIG. When the braking force acts, a force (arrow in FIG. 12) in the direction opposite to the traveling direction acts on the contact point of the tire 4. The wheel support member 1 (knuckle) is deformed from the position indicated by the broken line to the position indicated by the solid line so that the upper side is inclined in the direction of travel due to the backward direction component of the braking force. Therefore, a bending moment M5 and a bending moment M6 are applied to the main sliding shaft 3a and the sub sliding shaft 3b so as to deform the upper end portion in the direction of movement and to deform the lower end in the opposite direction.
On the other hand, the suspension member 2 is not affected by the braking force. Therefore, the displacement of the intermediate portion of each sliding shaft 3a, 3b is restricted by the main sliding bearing pipe 2c or the auxiliary sliding bearing pipe 2e of the suspension member 2, and the upper end is displaced forward of the vehicle. Is displaced to the rear of the vehicle and is bent into an "S" shape.

  FIG. 13 is a view showing a modified embodiment of the main sliding shaft 3a and the auxiliary sliding shaft 3b when a longitudinal force is applied to the wheel center 7. As shown in FIG. This is the case, for example, when riding on a curb when the vehicle moves backward. When a longitudinal force (arrow in FIG. 13) acts on the wheel center 7, the wheel support member 1 (knuckle) is deformed from the broken line position to the solid line position so that the whole moves in the forward direction. On the other hand, the suspension member 2 is not influenced by the longitudinal force. For this reason, shear forces M11 and M12 in the direction crossing the axis act on the upper and lower boundaries of the main sliding shaft 3a with the portion restrained by the main sliding bearing pipe 2c, and the upper and lower end portions advance It is displaced in the direction side and bent into "く". In addition, shear forces M21 and M22 in a direction crossing the axis act on the upper and lower boundaries of the portion restrained by the auxiliary sliding bearing pipe 2e on the auxiliary sliding shaft 3b, and the upper and lower end portions are in the advancing direction side It is displaced to "" and bent.

  Next, the relationship between the deformation of the main sliding shaft 3a and the auxiliary sliding shaft 3b and the increase in friction when the suspension member 2 slides will be described using FIGS. 14A to 16.

FIG. 14A schematically shows a state in which the upper and lower end portions of the sliding shaft are displaced in opposite directions and bent in an “S” shape, that is, the states shown in FIG. 10, FIG. 11 and FIG. . Such deformation is a factor that causes a shift in axis tilt angle (axis tilt shift).
On the other hand, FIG. 14B schematically shows an enlarged state in which the upper and lower end portions of the sliding shaft are displaced in the same direction and bent into a “く” shape, that is, the state shown in FIG. Such a deformation is a factor that causes a deviation (interaxial distance deviation) in the interaxial distance from the other sliding shaft (main sliding shaft).

  Then, when only a sliding bush is interposed between the sliding shaft and the bearing, if a moment (prying moment) acts on the sliding shaft in the direction in which the axis thereof is pricked, and the sliding shaft is tilted, As shown in FIG. 15, in the sliding shaft, portions close to the bearing end (portions A and B in the drawing) are pressed against the sliding bush. Then, variations (gap A> gap B) occur in the gap (gap) between the sliding shaft and the bearing, and the surface pressure becomes high in the portion with a small gap (C in the figure). If the sliding shaft makes a vertical stroke with respect to the sliding bush in this state, the frictional resistance of the parts (A and B) where the surface pressure is high increases, and the friction (sliding resistance) as a suspension increases. .

  When only a slide bush is interposed between the sliding shaft and the bearing, a shear force acts on the sliding shaft in a direction transverse to the axis, causing an interaxial distance shift, as shown in FIG. The sliding shaft is pressed against the sliding bush by a part of the circumferential surface (D part in the figure). Then, variations (gap C> gap D) occur in the gap (gap) between the sliding shaft and the bearing, and the surface pressure becomes high in the portion with a small gap (E in the figure). If the sliding shaft makes a vertical stroke with respect to the sliding bush in this state, the frictional resistance of the portion (D portion) where the surface pressure is high increases, and the friction (sliding resistance) as a suspension increases.

  Furthermore, in the in-wheel type suspension device, the suspension member strokes up and down along the sliding axis, but in the case of having a plurality of sliding axes, depending on the size and direction of the road surface input, In the case of (2), deviation occurs in the parallel relationship in the initial state and the distance between the sliding shafts. That is, in the in-wheel type suspension device having two slide shafts, it is possible to cope with the case where the shift change occurs simultaneously in the two slide shafts, but the shift generated in each operation is absorbed However, the friction increases further and it becomes difficult to stroke normally.

  On the other hand, in the first embodiment, as a displacement absorbing mechanism that absorbs slip displacement of the sliding bush 11 in contact with the auxiliary sliding shaft 3b and the auxiliary sliding shaft 3b in the connection portion of the suspension member 2 and the auxiliary sliding shaft 3b. And the elastic body bush 12 of

  That is, when the main sliding shaft 3a and the sub sliding shaft 3b are provided as the sliding shaft 3, the inclination change of the sub sliding shaft 3b or the change of the interaxial distance from the main sliding shaft 3a in the vertical stroke operation There is a misalignment like. This misalignment is also caused by product variations in which dimensional relationships and positional relationships when parts are assembled deviate from design values. When such misalignment occurs, as shown in FIG. 17, the elastic deformation of the elastic bush 12 absorbs the displacement displacement (= misalignment) of the auxiliary sliding shaft 3b, and the auxiliary sliding of the suspension member 2 An increase in friction at the connection portion between the bearing pipe 2e and the auxiliary sliding shaft 3b is suppressed.

  As described above, the variation in the shaft inclination and the change in the distance between the axes at the time of the sliding operation can be tolerated by the elastic deformation by the elastic body bush 12. For this reason, during suspension vertical movement during regular travel, normal sliding movement of the suspension member 2 with respect to the two slide shafts (the main slide shaft 3a and the sub slide shaft 3b) is enabled. As a result, in the in-wheel type suspension device IWS1 having the main sliding shaft 3a and the sub sliding shaft 3b, when the suspension member 2 slides along the sliding shaft 3, a sliding operation in which the increase in friction is suppressed is performed. Can be maintained.

In particular, in the first embodiment, the auxiliary sliding shaft 3b is set at a position farther from the tire 4 than the main sliding shaft 3a, and the input of the ground contact reaction force is relatively small, and this input is small An elastic bush 12 as a displacement absorbing mechanism is provided on the auxiliary sliding shaft 3b.
Thus, by realizing the displacement absorbing function in the sub-sliding shaft 3b having a smaller input, it is the main sliding shaft 3a having a large input that governs the sliding operation, and against the inclination and deformation of the shaft. Therefore, the secondary sliding shaft 3b having a small input follows. By doing so, it is possible to absorb changes in the inclination between the sliding shafts 3a and 3b and the distance between the sliding shafts 3a and 3b without causing a decrease in rigidity more than necessary as a suspension device.
As a result, during normal driving, the operation in the sliding axial direction accompanying the vertical movement of the suspension is maintained when an input from the road surface is generated when riding over a projection or the like, enabling normal sliding movement.

When the main sliding shaft 3a and the sub sliding shaft 3b are provided as the sliding shaft 3, defining the position of the sub sliding shaft 3b with respect to the main sliding shaft 3a governs the sliding operation. Is to specify that the main sliding shaft 3a has a large input. For this reason, it is possible to stabilize the behavior such as the vertical stroke of the tire 4 by specifying that the main sliding shaft 3a is the shaft that controls the sliding operation.
As a result, during normal driving, the operation in the sliding axial direction accompanying the vertical movement of the suspension is maintained when an input from the road surface is generated when riding over a projection or the like, enabling normal sliding movement.

Furthermore, in the first embodiment, the displacement absorbing mechanism is an elastic body bush 12 interposed between the sub sliding bearing pipe 2e of the suspension member 2 and the sliding bush 11 in contact with the sub sliding shaft 3b. did.
As described above, by using the elastically deformable elastic bush 12 as the displacement absorbing mechanism, the slight inclination of the auxiliary sliding shaft 3b due to misalignment or the like and the main sliding shaft along with the suspension vertical movement during regular driving. It is possible to absorb changes in the axial distance with 3a. As a result, there is an effect of maintaining the operation in the sliding direction along with the suspension vertical movement during regular travel, and a normal sliding operation is enabled.

[Other feature action]
In the in-wheel type suspension device, when the elastic member for elastically supporting the suspension member 2 is constituted by two coil springs disposed so as to sandwich the wheel center 7 as in the first embodiment, the following equation (3) , (4) holds.
M1 = K ₁ × L ₁ (3)
M2 = K ₂ × L ₂ (4)
K ₁ : spring constant of the first spring 51 K ₂ : spring constant of the second spring 52 L ₁ : vehicle longitudinal distance from the wheel center 7 to the first spring 51 L ₂ : wheel center 7 to the second spring 52 Distance to the vehicle longitudinal direction up to M1: The moment that the spring reaction force of the first spring 51 generates around the wheel center M2: The moment that the spring reaction force of the second spring 52 generates around the wheel center

Here, the moment M1 caused by the spring reaction force of the first spring 51 around the wheel center and the moment M2 caused by the spring reaction force of the second spring 52 cancel each other around the wheel center The resulting moment is reduced. That is, in order to reduce the moment generated around the wheel center, the sum of the moment M1 and the moment M2 may be zero, and the following equation (5) needs to be satisfied.
M = M1 + M2
= K ₁ × L ₁ + K ₂ × L ₂ = zero (5)

Thus, according to the magnitudes of the two spring constants K ₁ and K ₂ , the vehicle longitudinal distance L ₁ from the wheel center 7 to the first spring 51 and the vehicle longitudinal direction from the wheel center 7 to the second spring 52 be determined and the distance L _2, first, can spring reaction force of the second spring 51 and 52 is zero at all times the sum of the moments M1, M2 to produce around the wheel center, a moment generated around the wheel center It can be reduced.

In contrast, in Example 1, and the vehicle longitudinal distance L ₁ from the wheel center 7 to the first spring 51, the ratio between the vehicle longitudinal distance L ₂ from the wheel center 7 to the second spring 52, the first It is set to match the ratio of the reciprocal of the spring constant K ₁ of the spring 51 and the reciprocal of the spring constant K ₂ of the second spring 52.
Therefore, the twisting moment by the first spring 51 and the twisting moment by the second spring 52 are canceled out, and the moment generated around the wheel center can be reduced. That is, even when the spring constants K ₁ and K ₂ of the two coil springs (the first spring 51 and the second spring 52) are different, it is possible to reduce the twisting moment generated around the wheel center. In addition, even when individual differences among coil springs or interference with other parts are a problem, it is possible to reduce the twisting moment generated around the wheel center.
And, as a result, it is possible to suppress the twisting moment acting on the sliding shaft 3 (here, particularly, the main sliding shaft 3a here) and to reduce the friction.

Further, in the first embodiment, as the slide shafts 3 to which the suspension member 2 is slidably connected, the main slide shaft 3a and the sub slide shaft 3b are arranged in the longitudinal direction of the vehicle.
Here, in the case where there is only one sliding shaft, the sliding shaft should be rectangular in order to prevent the suspension member from being rotationally displaced around the sliding shaft when braking force or turning lateral force is generated on the tire. Measures such as cross-sectioning are required. In this case, there is a possibility that the friction may be increased due to a problem of processing accuracy or a problem such as the suspension member coming into contact with the sliding shaft surface of the rectangular cross section.

However, in the case where two slide shafts 3 (main slide shaft 3a and sub slide shaft 3b) are used as in the first embodiment, the wheel support member 1 and the suspension member 2 when the tire 4 is steered The relative rotational displacement can be supported by the two slide shafts 3 (main slide shaft 3a, sub slide shaft 3b). Therefore, it is not necessary to make the sliding shaft 3 into a rectangular cross section, and it becomes difficult for the suspension member 2 to come into contact with one another. Therefore, the increase in friction can be suppressed.
The moment supported by the sliding shafts 3a and 3b can be reduced as the distance between the main sliding shaft 3a and the auxiliary sliding shaft 3b is increased.

  Furthermore, in the first embodiment, the main sliding shaft 3a is disposed between the first spring 51 and the second spring 52, and the sub sliding shaft 3b is disposed at the vehicle front position relative to the first spring 51. . Here, the first spring 51 and the second spring 52 are arranged in the vehicle longitudinal direction across the wheel center 7. Therefore, the main sliding shaft 3a is disposed closer to the wheel center 7 than the sub sliding shaft 3b.

On the other hand, if the average spring reaction force line of the average spring reaction force generated between the first spring 51 and the second spring 52 and the ground contact reaction line passing through the wheel center 7 deviate from each other, Moment occurs around the wheel center.
Therefore, the moment generated around the wheel center mainly acts on the main sliding shaft 3a disposed relatively close, and it is possible to reduce the bending moment acting on the sub sliding shaft 3b. Become. As a result, the load on the auxiliary sliding shaft 3b can be reduced, and parts such as reducing the diameter of the auxiliary sliding shaft 3b can be reduced.

Next, the effects will be described.
In the in-wheel type suspension system of the first embodiment, the following effects can be obtained.

(1) A suspension component 2 having a suspension member 2 having one end connected to the wheel support member 1 provided on the wheel 9 to which the tire 4 is mounted and the other end elastically supported by the vehicle body (vehicle body attachment member 8) In the in-wheel type suspension device IWS1 at least a part of which is disposed in the wheel 9,
The suspension member 2 is slidably coupled to at least one or more slide shafts 3 provided on the wheel support member 1, and an elastic element 5 is disposed between the wheel support member 1 and the suspension member 2. ,
The elastic element 5 is a first elastic member (first spring 51) disposed at the vehicle front position relative to the wheel center 7 and a second elastic member disposed at the vehicle rear position relative to the wheel center 7 (second spring And 52).
As a result, when the suspension member 2 strokes in the vertical direction, the twisting moment acting on the sliding shaft 3 can be suppressed, and the friction can be reduced.

(2) The ratio of the distance from the wheel center 7 to the first elastic member (first spring 51) and the distance from the wheel center 7 to the second elastic member (second spring 52) The ratio of the reciprocal of the spring constant of 1 spring 51) to the reciprocal of the spring constant of the second elastic member (second spring 52) is made to coincide.
Thereby, in addition to the effect of (1), even if the spring constants K ₁ and K ₂ of the two elastic members (the first spring 51 and the second spring 52) are different, a pricking moment generated around the wheel center Can be reduced to reduce the friction moment acting on the sliding shaft 3 to further reduce the friction.

(3) The sliding shaft 3 is configured to have a first sliding shaft (main sliding shaft 3a) and a second sliding shaft (sub-sliding shaft 3b) aligned in the longitudinal direction of the vehicle.
Thereby, in addition to the effect of (1) or (2), the rotational displacement of the suspension member 2 with respect to the wheel support member 1 is prevented to make it difficult to cause the suspension member 2 to hit one side, and the increase of friction is suppressed. it can.

(4) The first sliding shaft (main sliding shaft 3a) is disposed between the first elastic member (first spring 51) and the second elastic member (second spring 52), and the second sliding is performed. The shaft portion (sub sliding shaft 3b) is arranged at the vehicle front position with respect to the first elastic member (first spring 51).
Thereby, in addition to the effect of (3), the main sliding shaft 3a can be disposed closer to the wheel center 7 than the sub sliding shaft 3b, and the twisting moment acting on the sub sliding shaft 3b is reduced. As a result, it is possible to reduce parts such as reducing the diameter of the auxiliary sliding shaft 3b.

(5) A displacement absorbing mechanism (elastic body bush 12) for absorbing displacement displacement of the sliding shaft (sub sliding shaft 3b) at the connection portion of the suspension member 2 and the second sliding shaft portion (sub sliding shaft 3b) It was set as having composition.
Thereby, in addition to the effect of (3) or (4), the variation of the shaft inclination and the change of the inter-axis distance at the time of sliding operation are allowed by the elastic deformation by the displacement absorbing mechanism (elastic body bush 12) It is possible to maintain the sliding motion with the increase of.

(Example 2)
The second embodiment is an example in which a slide guide structure for allowing a sliding movement in the displacement direction of the sliding shaft is provided as a displacement absorbing mechanism.

First, the configuration will be described.
FIG. 18 shows the structure (slide structure) of the connection portion of the suspension member and the secondary sliding shaft in Example 2, and FIG. 19 is a perspective view showing the slide structure. Hereinafter, based on FIG. 18 and FIG. 19, the connection structure of the suspension member of Example 2 and a sliding shaft is demonstrated.

  The second embodiment is an example using a slide structure interposed between the suspension member 2 and the auxiliary sliding shaft 3b and operating in a direction approximately perpendicular to the auxiliary sliding shaft 3b as a displacement absorbing mechanism. The fourth embodiment also has a slide structure as a displacement absorbing mechanism.

In the second embodiment, as shown in FIGS. 18 and 19, the slide structure has a slide guide structure in which the absorption direction of the displacement of the auxiliary sliding shaft 3b is defined using the slide plate 14 and the slide guide 15. Here, the slide plate 14 is a rectangular plate fixed to the sub slide bearing pipe 2 e. The slide guides 15 are a pair of guide plates attached to the front side vehicle support bracket 2 a by means of a pressing bracket 17 fixed by bolts 16, and can slide the slide plate 14 along the recess of the slide guide 15 opposed thereto.
The sliding direction (the arrow B direction in FIG. 19) of the auxiliary sliding shaft 3b can be freely determined according to the conditions and requirements, but in the second embodiment, it is a direction substantially coincident with the vehicle width direction .

Next, the operation will be described.
In the second embodiment, a slide structure operating in a direction approximately perpendicular to the sub slide shaft 3b is used as a displacement absorbing mechanism, and is interposed between the front vehicle support bracket 2a of the suspension member 2 and the sub slide shaft 3b. .

Here, when an input from the road surface occurs, for example, when the projection is carried over, the directions of the shaft inclinations of the two sliding shafts (main sliding shaft 3a, auxiliary sliding shaft 3b) differ, and the distance between the axes changes. Do. On the other hand, it is possible to smoothly perform the sliding operation of the sliding shafts 3a and 3b accompanying the vertical movement of the suspension while absorbing this by the sliding motion of the auxiliary sliding shaft 3b.
As a result, there is an effect of maintaining the operation in the sliding axial direction accompanying the vertical movement of the suspension when an input from the road surface occurs, for example, when riding over a protrusion, which enables a normal operation.

Further, in the second embodiment, as the slide structure, the slide plate 14 and the slide guide 15 are used to define the absorbing direction of the displacement of the auxiliary sliding shaft 3b.
By defining the slide direction in this way, when an input from the road surface occurs while riding on a projection or the like, as shown in FIG. 19, the movable slide direction (direction B) and the restraining slide direction to be restrained (direction C) Can be separated from That is, if there is a difference in inclination between the two sliding shafts 3a and 3b or a change in the distance between the axes under the required conditions, it absorbs in the movable sliding direction, otherwise it is rigid in the sliding prevention direction It can be secured.
As a result, there is an effect of maintaining the operation in the sliding axial direction accompanying the vertical movement of the suspension when an input from the road surface occurs, for example, when riding over a protrusion, and a normal operation can be enabled.

Next, the effects will be described.
In the in-wheel type suspension system of the second embodiment, the following effects can be obtained.

(6) The displacement absorbing mechanism is interposed between the front body support bracket 2a of the suspension member 2 and the sliding shaft (sub-sliding shaft 3b), relative to the sliding shaft (sub-sliding shaft 3b) A slide structure (slide plate 14 and slide guide 15) operating in a substantially perpendicular direction is adopted.
For this reason, in addition to the effect of (5), by sliding the sub-sliding shaft 3b against the displacement by absorbing it, the sliding operation of the sub-sliding shaft 3b along with the suspension vertical movement is smoothly performed. Can.

(Example 3)
The third embodiment is an example in which a relative rotation structure is provided as the displacement absorbing mechanism, which permits the tilting operation of the sliding shaft in the tilting direction.

First, the configuration will be described.
FIG. 20 shows the structure (relative rotation structure) of the connection portion of the suspension member and the auxiliary sliding shaft in the third embodiment. Hereinafter, based on FIG. 20, the connection structure of the suspension member of the third embodiment and the sliding shaft will be described.

  The third embodiment is interposed between the front vehicle support bracket 2a of the suspension member 2 and the auxiliary sliding shaft 3b as a displacement absorbing mechanism, and the inclination direction of the auxiliary sliding shaft 3b with respect to the auxiliary sliding bearing pipe 2e. It is an example using relative rotation structure 30 which permits the rotation operation to. The fourth embodiment also has a relative rotation structure as a displacement absorbing mechanism.

In the third embodiment, as shown in FIG. 20, the relative rotation structure 30 is configured by a so-called spheric bearing (self-centering type bearing) using the ball portion 31 and the ball support portion 32.
Here, the ball portion 31 has a cylindrical portion 31a fitted to the outside of the slide bush 11, and a spherical portion 31b bulging hemispherically from the outer peripheral surface of the cylindrical portion 31a. The ball support portion 32 has a support portion main body 32a fitted inside the sub slide bearing pipe 2e, and a ball inner surface 32b formed inside the support portion main body 32a. Then, the spherical portion 31b of the ball portion 31 makes spherical contact with the spherical inner surface 32b of the ball support portion 32, whereby the auxiliary sliding shaft 3b is in contact with the auxiliary sliding bearing pipe 2e supported by the front vehicle support bracket 2a. It can be tilted in the 360 ° direction.

Next, the operation will be described.
In the third embodiment, the relative rotation structure 30 including the ball portion 31 and the ball support portion 32 is used as a displacement absorbing mechanism, and is interposed between the front vehicle support bracket 2a of the suspension member 2 and the sub sliding shaft 3b.

  As shown in FIG. 21, when the auxiliary sliding shaft 3b is inclined by this structure and the secondary sliding shaft 3b is inclined due to a straining moment generated by the ground contact load, tire lateral force, braking force, etc. The ball portion 31 rotates relative to the ball support portion 32. For this reason, the sub sliding shaft 3b does not come into partial contact with the slide bush 11, and it is possible to avoid that the surface pressure around the sub sliding shaft 3b becomes partially high. As a result, it is possible to prevent an increase in frictional resistance and to suppress an increase in friction as a suspension.

Next, the effects will be described.
In the in-wheel type suspension system of the third embodiment, the following effects can be obtained.

(7) The displacement absorbing mechanism is interposed between the front body support bracket 2a of the suspension member 2 and the sliding shaft (sub-sliding shaft 3b), relative to the sliding shaft (sub-sliding shaft 3b) It is set as the structure used as the relative rotation structure 30 which operate | moves to an inclination direction.
For this reason, in addition to the effect of (5), in the case where the axis inclination angle of the auxiliary sliding shaft 3b is shifted, it is avoided that the surface pressure around the auxiliary sliding shaft 3b is partially increased. It is possible to prevent an increase and to suppress an increase in friction as a suspension.

(Example 4)
The fourth embodiment is an example using a combined mechanism of a slide structure and a relative rotation structure as a displacement absorbing mechanism.

First, the configuration will be described.
FIG. 22 shows the structure (slide structure + relative rotation structure) of the connection portion between the suspension member and the auxiliary sliding shaft in the fourth embodiment. Hereinafter, based on FIG. 22, the connection structure of the suspension member of Example 4 and a sliding shaft is demonstrated.

  The fourth embodiment uses, as a displacement absorbing mechanism, a structure having a slide structure (FIG. 18) and a relative rotation structure (FIG. 20) while being interposed between the suspension member 2 and the auxiliary sliding shaft 3b. It is an example.

  As shown in FIG. 22, the slide structure has a slide guide structure in which the absorption direction of the shift displacement of the sub slide shaft 3 b is defined using the slide plate 14 and the slide guide 15. The amount of displacement of the displacement displacement is in the range of the amount of sliding of the slide plate 14 set outside the auxiliary sliding bearing pipe 2e. Further, a horizontal gap K is provided between the slide plate 14 and the slide guide 15.

  The relative rotation structure 30 is interposed between the auxiliary sliding bearing pipe 2e of the suspension member 2 and the sliding bush 11 in contact with the auxiliary sliding shaft 3b, as shown in FIG. 22, and the inclination of the auxiliary sliding shaft 3b is It is set as the structure made into the perimeter direction, without defining the absorption direction of displacement. The absorbed amount of inclination displacement is within the rotatable range of the ball portion 31.

  Further, in the fourth embodiment, as shown in FIG. 23, the height position of the displacement absorbing mechanism consisting of the slide structure and the relative rotation structure is the upper end 2α of the main sliding bearing pipe 2c connected to the main sliding shaft 3a. It is set so as to fall within the height region H between the lower end 2β.

Next, the operation will be described.
In the fourth embodiment, as a displacement absorbing mechanism, a structure having a slide structure provided between the suspension member 2 and the auxiliary sliding shaft 3b and a relative rotation structure 30 is used.
As described above, by using a structure in which two types of displacement absorbing mechanisms are used in combination, when an input from the road surface on a projection or the like occurs obliquely from the traveling direction, two sliding shafts (main An increase in change of the axis inclination of the axis 3a and the auxiliary sliding axis 3b) and the distance between the axes is expected. That is, even if the amount of displacement displacement is large, the absorption of the displacement displacement due to the sliding motion of the slide structure and the absorption activity of the tilt displacement due to the rotation motion of the relative rotational structure 30 can sufficiently absorb this.

Furthermore, by providing a gap K in the horizontal direction, when an inter-axial distance deviation between the main sliding shaft 3a and the sub sliding shaft 3b occurs, the slide plate 14 is displaced in the horizontal direction, and the shaft It is possible to tolerate a gap between the two.
As a result, even if the shaft inclination shift and the inter-axis distance shift are simultaneously caused by the road surface input that is obliquely shifted from the traveling direction at the time of projection, etc., the operation in the sliding axis direction accompanying the suspension vertical movement is maintained. It is effective and enables normal operation. Thereby, the friction reduction effect can be further enhanced.

And in the slide structure of the slide type in which the suspension member 2 is slidably connected to the slide shaft 3 (the main slide shaft 3a and the sub slide shaft 3b) of the wheel support member 1, the suspension structure along the slide shaft The sliding stroke amount is determined by the length of the suspension member 2 from the vehicle body (vehicle body attachment member 8) to the wheel connecting portion (main sliding bearing pipe 2c, sub sliding bearing pipe 2e), and the wheel connecting portion (main sliding bearing pipe 2c, determined by the sliding shaft support length of the auxiliary sliding bearing pipe 2e).
Therefore, it is necessary to secure a sufficient sliding stroke of the suspension member 2 on the bound side (the compression side of the elastic element 5) and the rebound side (the extension side of the elastic element 5).

On the other hand, the sliding stroke of the suspension member 2 secured in the main sliding shaft 3a is determined by the distance between the lower side plate 1c of the wheel support member 1 and the lower end of the main sliding bearing pipe 2c. The sliding stroke of the suspension member 2 on the rebound side is determined by the distance between the upper plate 1b of the wheel support member 1 and the upper end of the main sliding bearing pipe 2c.
Therefore, in order to maintain the sliding stroke amount of the suspension member 2 along the main sliding shaft 3a, the height position of the auxiliary sliding bearing pipe 2e connected to the auxiliary sliding shaft 3b is set to the main sliding. It should be set so as to be within the height region H between the upper end 2α and the lower end 2β of the bearing pipe 2c.

On the other hand, in the fourth embodiment, the height positions of the auxiliary sliding bearing pipe 2e and the displacement absorbing mechanism are contained within the height region H between the upper end 2α and the lower end 2β of the main sliding bearing pipe 2c. It is set. Therefore, when the suspension member 2 strokes in the vertical direction, the sub slide bearing pipe 2 e does not interfere with the wheel support member 1 earlier than the main slide bearing pipe 2 c.
Therefore, the stroke amount of the suspension member 2 set along the main sliding shaft 3a can be maintained, and a sufficient stroke of the suspension member 2 can be guaranteed.

Next, the effects will be described.
In the in-wheel type suspension system of the fourth embodiment, the following effects can be obtained.

(8) A slide which is interposed between the suspension member 2 and the slide shaft (sub slide shaft 3b) and operates in a direction approximately perpendicular to the slide shaft (sub slide shaft 3b). The structure (slide plate 14 and slide guide 15) and the relative rotation structure 30 that operates in the direction of inclination of the slide shaft (sub slide shaft 3b) are combined.
For this reason, in addition to the effect of (5), when the displacement direction of the sliding shaft to be absorbed includes an oblique direction, or when a specific displacement amount is large, the displacement displacement absorbing action by the sliding operation and rotational operation is sufficient. This can be absorbed.

  As mentioned above, although the in-wheel type suspension apparatus of this invention was demonstrated based on Example 1- Example 4, about a specific structure, it is not limited to these Examples, Each of a claim is indicated. Changes in design, additions, and the like are permitted without departing from the scope of the claimed invention.

In Example 1, the distance L ₁ from the first spring 51 to wheel center 7, an example which is set to be smaller than the distance L ₂ from the second spring 52 until the wheel center 7. In this case, in order to establish the above equation (1), the relationship of K ₁ <K ₂ is established.
However, not limited to this, as shown in FIG. 24A, L ₁ = L ₂ may be used, or as shown in FIG. 24B, L ₁ > L ₂ may be used. In any case, equation (2) is established by setting the spring constants K ₁ and K ₂ of the first and second springs 51 and 52 so that the above equation (1) is established. Thus, the sum of the moments M1 and M2 generated by the spring reaction force of the first and second springs 51 and 52 around the wheel center can be always zero, and the moment generated around the wheel center can be reduced. .

  Moreover, in Examples 1-4, the example which uses the main sliding shaft 3a and the sub sliding shaft 3b as the sliding shaft 3 was shown. However, as the sliding shaft, one sliding shaft may be used, or three or more sliding shafts may be used.

  Further, in the first to fourth embodiments, of the main sliding shaft 3a and the sub sliding shaft 3b, an example is shown in which a displacement absorbing mechanism for absorbing displacement displacement is applied to the sub sliding shaft 3b. However, a displacement absorbing mechanism that absorbs displacement displacement may be applied to both the main sliding shaft and the secondary sliding shaft. In this case, the displacement displacement absorption amount by the main sliding shaft may be made different from the displacement displacement absorption amount by the sub sliding shaft.

  Furthermore, in the first to fourth embodiments, the in-wheel type suspension device of the present invention is applied to the rear wheel (following wheel). However, the in-wheel suspension system of the present invention can also be applied to drive wheels. In short, any in-wheel suspension system in which at least a portion of the suspension components are disposed in the wheel on which the tire is mounted can be applied.

IWS 1 In-wheel type suspension device 1 Wheel support member 2 Suspension member 2a Front side vehicle support bracket 2b Rear side vehicle support bracket 2c Main sliding bearing pipe 2d Elastic element supporting bracket 2e Sub sliding bearing pipe 3 Sliding shaft 3a Main sliding shaft (First sliding shaft)
3b Secondary sliding shaft (second sliding shaft)
4 tire 5 elastic element 51 first spring (first elastic member)
52 Second spring (second elastic member)
6 elastic bush 7 wheel center 8 body mounting member 9 wheel 10 damping element 11 slip bush (slip bearing portion)
12 Elastic bush (displacement absorption mechanism)
14 Slide plate (displacement absorption mechanism)
15 Slide guide (displacement absorption mechanism)
30 Relative rotation structure (displacement absorption mechanism)

Claims (7)

An in-wheel having a suspension member connected at one end to a wheel supporting member provided on a wheel mounting a tire and having the other end elastically supported on a vehicle body, wherein at least a part of a suspension component is disposed in the wheel Type suspension system,
And connecting an elastic element between the wheel support member and the suspension member while slidably connecting the suspension member to at least one sliding shaft provided on the wheel support member.
The slide shaft includes a first slide shaft portion and a second slide shaft portion,
It said elastic element, possess a first elastic member disposed on the vehicle front side position than the wheel center, and a second elastic member disposed on the vehicle rear side position than the wheel center,
The first sliding shaft portion is disposed between the first elastic member and the second elastic member, and is disposed closer to the wheel center than the second sliding shaft portion. In-wheel type suspension system. An in-wheel having a suspension member connected at one end to a wheel supporting member provided on a wheel mounting a tire and having the other end elastically supported on a vehicle body, wherein at least a part of a suspension component is disposed in the wheel Type suspension system,
And connecting an elastic element between the wheel support member and the suspension member while slidably connecting the suspension member to at least one sliding shaft provided on the wheel support member.
As the sliding shaft, it has a first sliding shaft portion and a second sliding shaft portion aligned in the longitudinal direction of the vehicle,
It said elastic element, possess a first elastic member disposed on the vehicle front side position than the wheel center, and a second elastic member disposed on the vehicle rear side position than the wheel center,
The first sliding shaft portion is disposed between the first elastic member and the second elastic member, and the second sliding shaft portion is disposed at a vehicle front position relative to the first elastic member. In-wheel type suspension device characterized by An in-wheel having a suspension member connected at one end to a wheel supporting member provided on a wheel mounting a tire and having the other end elastically supported on a vehicle body, wherein at least a part of a suspension component is disposed in the wheel Type suspension system,
And connecting an elastic element between the wheel support member and the suspension member while slidably connecting the suspension member to at least one sliding shaft provided on the wheel support member.
As the sliding shaft, it has a first sliding shaft portion and a second sliding shaft portion aligned in the longitudinal direction of the vehicle,
It said elastic element, possess a first elastic member disposed on the vehicle front side position than the wheel center, and a second elastic member disposed on the vehicle rear side position than the wheel center,
In at least one of the connection portion of the suspension member and the first slide shaft portion, and the connection portion of the suspension member and the second slide shaft portion, a displacement absorbing mechanism for absorbing a shift displacement of the slide shaft is disclosed An in-wheel type suspension device characterized by having . In the in-wheel type suspension device according to claim 3 ,
The in-wheel type suspension device is characterized in that the displacement absorbing mechanism is a sliding structure interposed between the suspension member and the sliding shaft and operated in a direction approximately perpendicular to the sliding shaft. In the in-wheel type suspension device according to claim 3 ,
The in-wheel type suspension device characterized in that the displacement absorbing mechanism is interposed between the suspension member and the sliding shaft, and has a relative rotation structure that operates in a tilting direction with respect to the sliding shaft. In the in-wheel type suspension device according to claim 3 ,
The displacement absorbing mechanism is interposed between the suspension member and the sliding shaft, and has a sliding structure that operates in a direction approximately perpendicular to the sliding shaft, and operates in a direction of inclination with respect to the sliding shaft An in-wheel type suspension device characterized by having a relative rotation structure. The in-wheel suspension system according to any one of claims 1 to 6 ,
The ratio of the distance from the wheel center to the first elastic member and the distance from the wheel center to the second elastic member, the reciprocal of the spring constant of the first elastic member, and the spring of the second elastic member An in-wheel type suspension device characterized by substantially matching the ratio with the reciprocal of a constant.