JP2002002245A - Front suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rationalize the position of the edge of the wheel of a lower link as securing the reliability of the installation point of the wheel side of the lower link. SOLUTION: The joining structure of a transverse link 1 and a knuckle spindle 4 with a ball-joint 3 is provided in the lower side of the knuckle spindle 4 with a socket 3a opened upward beneath the knuckle spindle 4, and a spheroidal guide part 3b fitted in the socket part 3a. A screw part 3c which constitutes the protruded part sticking out from the upper side of the spheroidal guide part 3b is fastened with the edge of the wheel of the transverse link 1. The lower side of a shock absorber 7 is connected to the transverse link 1. An installation point P2 on the transverse link 1 of the lower side of the shock absorber 7 is offset by δ, higher than the link axis L of the transverce link 1. However, in the state of non-locking, the axis S of a chock absorber 7 is set to pass a link axis L.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of connecting a lower link to a wheel supporting member via a ball joint,
The present invention relates to a front suspension device in which a suspension spring is supported by the lower link.

[0002]

2. Description of the Related Art In a front suspension device, generally, a wheel-side end of a lower link is connected to a knuckle spindle (wheel supporting member) via a ball joint. Here, the ball joint includes a spherical spherical guide portion and a projecting portion that projects radially integrally with the spherical guide portion, and is configured by fitting the spherical guide portion into a concave socket portion. . Note that the shape of the spherical guide portion is not necessarily spherical.

[0003] Usually, for example, Japanese Patent Application Laid-Open No. 5-2012
It has a configuration described in Japanese Patent Application Laid-Open No. 16. That is,
As shown in FIG. 12, a socket portion 3a opened upward to the wheel side end portion 1a of the lower link 1 is provided, and a spherical guide portion 3b is fitted into the socket portion 3a.
A projection 3c projecting upward from the spherical guide 3b is fastened to a lower portion of the knuckle spindle 4.

The disk rotor 1 of the brake device is located outside the position of the ball joint 3 in the vehicle width direction.
The disk rotor 17 and the ball joint 3 face each other in the vehicle width direction. Reference numeral 7 denotes a shock absorber, reference numeral 8 denotes a suspension spring,
Reference numeral 18 represents a wheel.

In the above configuration, the position of the center of rotation of the lower link 1 and the knuckle spindle 4 (the center of rotation P1 of the ball joint 3) can be lowered, so that a required span is secured between the lower link 1 and the knuckle spindle 4. , Can increase lateral rigidity.

[0006]

Here, the vertical force from the contact point is received by the suspension spring 8,
When the lower portion of the suspension spring 8 is supported by the lower arm 1, the reaction force F applied to the lower arm 1 from the suspension spring 8 is applied downward, that is, in a direction in which the spherical guide portion 3b comes out of the socket portion 3a. .

For this reason, from the viewpoint of ensuring the reliability of the ball joint 3, the dimensions of the ball joint 3 are designed to be large, the swing angle of the ball joint 3 is controlled to be small, and the socket portion 3a and the spherical guide portion 3b are formed. It is required to increase the preload during the period. However, increasing the size leads to an increase in cost and weight.
Restricting the swing angle leads to a reduction in the suspension stroke and a decrease in the turning angle of the tire. In addition, an increase in preload leads to an increase in friction, which is one of the causes of adverse effects on ride comfort and steering feeling.

Further, the above configuration has a problem that the operating friction of the ball joint 3 is large. That is, as described above, when an external force is applied in a downward direction, that is, in a direction in which the spherical guide portion 3b comes out of the socket portion 3a due to the reaction force from the suspension spring 8, as shown in FIG. The contact portion between the upper portion of the socket 3b and the upper portion of the socket portion 3a becomes a pressure receiving portion R (an annular portion near the opening end of the socket portion 3a). As a result, when the ball joint 3 swings, the position of the pressure receiving portion R is increased. Is increased by an amount that is offset from the rotation axis Q at the time of steering, thereby increasing the operation friction of the ball joint.

In order to prevent dust from entering the ball joint 3 between the socket portion 3a and the spherical guide portion 3b, an opening of the socket portion 3a is covered so as to cover the opening.
When a dust cover (boot) is provided on the outer periphery of the protruding portion 3c, there is a problem that the dust cover is easily deteriorated because it directly receives heat from the disk rotor 17.

On the other hand, as described in Japanese Patent Application Laid-Open No. Hei 7-96831, the direction of the reaction force F from the suspension spring 8 is opposite to the direction in which the spherical guide portion 3b comes out of the socket portion 3a. . That is, in this front suspension device, as shown in FIG. 13, the knuckle-side mounting portion and the lower link-side mounting portion are turned upside down,
The projection 3c is configured to project downward.

In this configuration, the position of the pressure receiving portion with respect to the input from the suspension spring 8 is located on or near the rotation axis at the time of turning, so that friction at the time of operating the ball joint is reduced. However,
The link axis L of the lower link 1 moves upward by an amount corresponding to the upward movement of the socket 3a and the spherical guide 3b, that is, the upward movement of the rotation center P1 of the ball joint 3. That is, the lower link 1 and the upper link (not shown)
Alternatively, as a result of the distance from the wheel center W being reduced by that amount, there is a problem that the lateral rigidity is reduced by that amount.

In each of the above-mentioned front suspension devices, since the socket portion 3a is provided on the lower link 1, the rotation center P1 of the ball joint 3 is determined at the position of the wheel side end 1a of the lower link 1. You. Further, in the configuration shown in FIG. 12, if the wheel-side end 1a of the lower link 1 is moved outward in the vehicle width direction, the link length becomes longer, but as shown in FIG.
7, the wheel-side end 1a of the lower link 1 swings, so that a required distance between the rotation center P1 of the ball joint 3 provided on the wheel-side end 1a and the disk rotor 17 is increased. The link length is restricted in that it must be secured. In the configuration shown in FIG. 13, the position of the rotation center P <b> 1 of the ball joint 3 in the vehicle width direction is regulated by the wheel support member 4.

As described above, the conventional front suspension apparatus has a low degree of freedom in link arrangement from the above viewpoint. The present invention has been made by paying attention to the above points, and while rationalizing the required lateral rigidity and the reliability of the mounting point of the lower link on the wheel side, rationalizing the position of the wheel side end of the lower link. The task is to achieve

[0014]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a wheel support member for rotatably supporting a wheel, wherein a wheel-side end of a lower link is provided via a ball joint. A front suspension device wherein the lower link is connected to the lower link directly or via a shock absorber, wherein the connection between the lower link and the wheel supporting member by the ball joint is formed on the wheel supporting member. The spherical guide portion is rotatably inserted into the socket portion which is opened upward, and the wheel-side end of the lower link is fixed to a projecting portion projecting upward from the spherical guide portion. Things.

Next, according to the second aspect of the present invention, the input point of the reaction force from the suspension to the lower link is vertically set with respect to the link axis of the lower link. It is characterized by being offset. Next, the invention described in claim 3 is:
With respect to the configuration according to claim 1 or 2, the wheel-side end portions of the two lower links are connected to the wheel support member that rotatably supports the wheel via respective ball joints. A lower portion of the suspension spring is connected to one of the lower links of the book directly or via a shock absorber.

Next, according to a fourth aspect of the present invention, in the configuration of the third aspect, the one of the lower links is
Of the lower links, the lower link on the front side in the vehicle longitudinal direction, and the wheel side end of one of the lower links is turned away from the other lower link on the inner wheel during steering by the reaction force of the suspension spring. When the vehicle is steered, the outer wheel swings in a direction approaching the other lower link.

Next, according to a fifth aspect of the present invention, in the configuration according to the fourth aspect, the input point of the reaction force from the suspension is offset upward with respect to the link axis of the lower link, and The reaction force from the suspension spring passes through the link axis of the one lower link or its vicinity when the wheel is not steered.

[0018]

According to the first aspect of the present invention, the rotation center between the lower link and the wheel support member is provided by providing the socket portion on the wheel support member side and fitting the spherical guide portion from above. In a state in which the ball guide is arranged as low as possible, the direction of the reaction force from the suspension spring and the direction in which the spherical guide portion comes off from the socket portion of the ball joint can be set in opposite directions. As a result, it is possible to arrange the link axis of the lower link as low as possible while increasing the reliability of the ball joint without increasing the size of the ball joint, and to secure required lateral rigidity.

Further, as a result that the pressure receiving portion at the ball joint with respect to the reaction force from the suspension spring is located between the lower portion of the socket portion and the lower portion of the spherical guide portion, the pressure receiving portion is on or about the rotating shaft during steering. The arm of the moment is small because it is arranged near. Therefore, friction at the time of operating the ball joint is reduced. Further, in the above configuration, by providing the socket portion on the wheel support member, the rotation center of the ball joint can be disposed lower and outward in the vehicle width direction than the position of the wheel-side end of the lower link. . For this reason, it is possible to increase the link length of the lower link, and the degree of freedom in designing the link arrangement is improved.

Further, since the wheel supporting member is interposed between the disc rotor of the brake device and the ball joint, even if a dust cover is provided on the ball joint, the dust cover can be moved by the disc supporting member by the wheel supporting member. Protected from heat. Here, when the ball joint is arranged as described above, since the rotation center of the ball joint is located on the wheel support member side, the wheel side end of the lower link swings around the rotation center in the vehicle longitudinal direction. It becomes easy to move. On the other hand, when the invention described in claim 2 is adopted, the link axis of the lower link and the reaction force input point from the suspension spring are vertically offset, and the wheel of the lower link is positively activated by the reaction force. The swing direction of the side end can be regulated.

In this case, in the suspension according to the second aspect, since the wheel-side ends of the two lower links are arranged side by side, the swing of the wheel-side end of one of the lower links is a particular problem. However, in the invention according to claim 3, since the swing direction of the wheel-side end of one of the lower links can be positively regulated as described above, each of the two lower links is It is possible to reduce the dimension between the wheel side ends.

According to the fourth aspect of the invention, at the time of turning, the two lower links relatively approach each other due to the turning of the wheels at the inner wheel, but one of the lower links is caused by the reaction force from the suspension spring. The wheel-side end of the link swings away from the other lower link. In addition, at the time of steering, on the outer wheel, two lower links are relatively separated by steering of the wheel, and one lower link approaches the knuckle stopper, but swings in a direction approaching the other lower link, Move away from the knuckle stopper by that much. From the above, for example, it is possible to increase the steering angle by that much, or to arrange the wheel side ends of the two lower links closer to each other, which leads to an improvement in the degree of freedom in design.

At this time, if the invention according to claim 5 is adopted, it is possible to suppress the swing of the lower link in the vehicle longitudinal direction due to the reaction force from the suspension spring in the non-steering state.

[0024]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view for explaining a front suspension device according to the present embodiment. FIG. 2 is a diagram illustrating a connection structure between the traverse link 1 and the knuckle spindle 4.

As shown in FIG. 1, the lower link of the front suspension device according to the present embodiment is disposed on a transverse link 1 extending in the vehicle width direction and rearward of the transverse link 1 in the vehicle longitudinal direction. And a compression rod 2. As shown in FIG. 2, the transverse link 1 has a wheel-side end 1a connected to a lower portion of a knuckle spindle 4 via a ball joint 3 and a vehicle-body-side end 1b connected via a bush 5 to a vehicle body-side member 16. Are connected to be able to swing up and down. The knuckle spindle 4 forms a wheel supporting member that rotatably supports the wheel.

The connection structure of the transverse link 1 and the knuckle spindle 4 by the ball joint 3 is as follows.
It is as shown in FIG. That is, a socket portion 3a opened upward is provided below the knuckle spindle 4, and a spherical guide portion 3b is fitted into the socket portion 3a. The screw portion 3c that protrudes upward from the spherical guide portion 3b and forms a protruding portion is fastened to the wheel-side end 1a of the transverse link 1.

In order to prevent dust from entering between the socket portion 3a and the spherical guide portion 3b, a cylindrical elastic body is provided around the screw portion 3a so as to cover the opening of the socket portion 3a. Dust cover 19 is provided. The compression rod 2 has a wheel-side end 2a.
Is connected to a lower portion of the knuckle spindle 4 via a ball joint 6, and the vehicle body side end 2b is connected to a vehicle body side member (not shown) via a bush. The configuration of the ball joint 3 is such that a spherical guide portion is fitted into a socket portion formed on the compression rod 2 from below, and a screw portion projecting downward from the spherical guide portion is connected to a lower portion of the knuckle spindle 4. ing.

The lower portion of the shock absorber 7 is connected to a position near the wheels of the transverse link 1. The shock absorber 7 extends upward and has an upper end supported by a vehicle body-side member. The shock absorber 7
A suspension spring 8 is attached to the upper part of the vehicle. That is, the lower part of the suspension spring 8 is connected to the transverse link 1 via the shock absorber 7.

As shown in FIG. 2, the attachment point P2 of the lower portion of the shock absorber 7 to the transverse link 1 is offset by δ above the link axis L of the transverse link 1 as viewed from the vehicle longitudinal direction. Are arranged as follows. However, as shown in FIG. 3 which is a schematic view from the vehicle width direction and FIG. 4 which is a plan view, the axis S of the shock absorber 7 passes through the link axis L in the non-steering state. Is set to

A knuckle arm 9 projects from the knuckle spindle 4 to the rear in the front-rear direction of the vehicle body, and a tie rod (reference numeral 10 in FIG. 1) of a steering device is connected to a tip end of the knuckle arm 9. In FIG. 1,
Reference numeral 11 denotes an upper link including an A-arm,
The wheel side end 11 a is connected via a ball joint 13 to the upper end of an extension 12 extending upward from the knuckle spindle 4.

Further, as shown in FIG. 2, a disk rotor 17 of the brake device is disposed outside of the ball joint 3 in the vehicle width direction. Code 18
Indicates a wheel to which a tire is attached. Next, the operation, effects, and the like of the front suspension device having the above configuration will be described with reference to the drawings.

The ball joint 3 for connecting the transverse link 1 and the knuckle spindle 4 has a structure in which a spherical guide portion 3b is fitted from above into a socket portion 3a opened upward, so that a shock absorber 7 is provided.
The downward reaction force F input from the
The ball guide 3b is prevented from coming off from the position a, so that it is not necessary to enlarge the ball joint 3 more than necessary. This also means that there is no need to restrict the swing angle of the ball joint 3 to a small value, and the socket 3a and the spherical guide 3
The preload during b does not need to be increased more than necessary.

Moreover, since the socket portion 3a is provided on the knuckle spindle 4 side, the transverse link 1 of the lower arm, which mainly receives a lateral force, can be prevented from being raised at the wheel axis position of the link axis L. That is, even if the wheel side end 1c of the transverse link 1 is set high, the vertical distance between the link axis L of the transverse link 1 and the upper link 11 is prevented from being reduced. That is, as a result of securing a required span between the upper link or the wheel center and the lower link, a desired lateral rigidity is secured.

In the above configuration, the socket 3
Since a is provided on the knuckle spindle 4, the rotation center P1 of the ball joint 3 can be disposed below and outward in the vehicle width direction from the position of the wheel-side end 1a of the transverse link 1. Therefore, the transverse link 1
The link length of the lower link can be set longer than its own length, or the connection point (P1) to the knuckle spindle 4 can be set by offsetting with the position of the wheel side end 1a of the transverse link 1. The degree of freedom in designing the link arrangement is improved.

Further, since the knuckle spindle 4 is disposed between the disc rotor 17 and the ball joint 3 which generate heat during braking (see FIG. 2), even if the dust cover 19 is provided on the ball joint 3, The dust cover 19 is protected from the heat of the disk rotor 17, and is advantageous in durability. Further, the pressure receiving portion R of the ball joint 3 against the reaction force F from the suspension spring 8 is formed between the lower portion of the socket portion 3a and the spherical guide portion 3b.
As a result, the pressure receiving portion R is disposed on or near the rotation axis Q at the time of turning. Therefore, the arm of the moment becomes smaller, and the friction at the ball joint 3 during the operation of the ball joint becomes smaller.

At this time, the wheel-side end 1c of the transverse link 1 is arranged offset upward by δ with respect to the rotation center P1 of the ball joint 3 as a result. Can easily swing in the vehicle longitudinal direction about the rotation center P1. On the other hand, in the front suspension device of the present embodiment, the mounting point P1 from the shock absorber 7, that is, the input point P1 of the reaction force F from the suspension spring 8 is moved upward from the link axis L of the transverse link 1. As a result of the offset arrangement, the swing can be positively restricted by the reaction force F.

When the wheel is not steered, the axis S of the shock absorber 7 is designed to pass through the link axis L. Therefore, even if the suspension spring 8 is offset as described above, As a result, the transverse link 1 is urged in a direction passing through the link axis L by the reaction force F from the vehicle (see FIGS. 2 and 3), and the wheel end 1a of the transverse link 1 swings in the vehicle longitudinal direction. Movement is suppressed.

Considering the case where the wheels are steered from the above state, as shown in FIGS. 6 and 7, at the steered inner wheels, the wheel-side attachment point of the transverse link 1 is displaced forward in the vehicle longitudinal direction. Reaction force F of suspension spring 8
Is displaced so that it passes through the front side of the link axis L,
As shown in FIG. 8, the wheel end 1a of the transverse link 1 swings around the rotation center P1 of the ball joint 3 toward the front side in the vehicle longitudinal direction by the reaction force F, as shown in FIG. Move away from end 2a.

Here, symbols P ', L', and S 'represent the rotation center of the ball joint 3, the position of the link axis, and the axis of the shock absorber in the non-steering state, respectively. The same applies hereinafter. On the other hand, on the steered outer wheel, as shown in FIGS. 9 and 10, as a result of the wheel-side attachment point of the transverse link 1 being displaced rearward in the vehicle longitudinal direction, the direction of the reaction force F of the suspension spring 8 changes to the link axis L. 1 by the above-mentioned reaction force F.
As shown in FIG. 1, the wheel side end 1a of the transverse link 1 swings rearward in the vehicle longitudinal direction around the rotation center P1 of the ball joint 3 and moves away from the knuckle stopper 14 provided on the knuckle spindle 4. Rocks.

Here, the swing of the wheel side end 1a of the transverse link 1 occurs in the vehicle longitudinal direction about the rotation center P1 of the ball joint 3 when viewed from the vehicle width direction. Since it is displaced in the vehicle longitudinal direction about the vehicle body side attachment point P3, as can be seen from FIGS. 6 and 9, the link axis L is one of the vehicle longitudinal directions regardless of whether it is a steered inner wheel or a steered outer wheel. Swings in the vehicle front-rear direction while slightly heading inward in the vehicle front-rear direction. That is, for example, as shown in FIG. 6, in the steered inner wheel, the knuckle stopper 14 is displaced outward in the vehicle width direction, while being swung toward the knuckle stopper 14 side. The end 1a is slightly displaced inward in the vehicle width direction. For this reason, even if the wheel end 1a of the transverse link 1 is displaced to the front in the vehicle longitudinal direction in the steered inner wheel, the knuckle stopper 14 does not collide. The same applies to the steered outer wheel, as can be seen from FIG.

In the above embodiment, the lower link is 2
Although the case where it is composed of lower links is illustrated,
It is not limited to this. For example, the lower link may be constituted by an A-arm. The point is that the lower end of the suspension spring 8 can be connected directly or indirectly to the lower link. For example, the steering wheel side end of the lower link may be set to swing positively in the direction of escaping from the knuckle stopper 14 at the time of turning to increase the steering angle.

In the above embodiment, the case where the suspension spring 8 is attached to the shock absorber 7 is exemplified.
A front suspension device of a type separately provided from the suspension spring 8 including the coil spring 8 or the like may be used.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a front suspension according to an embodiment according to the present invention.

FIG. 2 is a view showing a connection between a transverse link and a knuckle spindle according to the embodiment of the present invention, as viewed from the vehicle front-rear direction.

FIG. 3 is a diagram illustrating a relationship between wheel-side ends of two lower links when the vehicle is not steered according to the embodiment of the present invention, as viewed from a vehicle width direction.

FIG. 4 is a plan view showing an arrangement of a lower link at the time of non-steering according to the embodiment based on the present invention.

FIG. 5 is a diagram illustrating a relationship between a pressure receiving portion and a rotation shaft according to the embodiment based on the present invention.

FIG. 6 is a plan view showing an arrangement of a lower link of a steered inner wheel according to the embodiment based on the present invention.

FIG. 7 is a view showing the behavior of the steered inner wheel according to the embodiment according to the present invention, as viewed from the vehicle width direction.

FIG. 8 is a diagram showing the behavior of the wheel link side end of the transverse link in the steered inner wheel according to the embodiment according to the present invention, as viewed from the vehicle width direction.

FIG. 9 is a plan view showing the arrangement of the lower link of the steered outer wheel according to the embodiment of the present invention.

FIG. 10 is a diagram showing the behavior of the steered outer wheel according to the embodiment according to the present invention, as viewed from the vehicle width direction.

FIG. 11 is a diagram showing a behavior of a wheel side end of a transverse link in a steered outer wheel according to an embodiment according to the present invention, as viewed from a vehicle width direction.

FIG. 12 is a view showing an arrangement of a lower link in a conventional example, as viewed from a vehicle front-rear direction.

FIG. 13 is a view showing an arrangement of a lower link according to another conventional example, as viewed from a vehicle front-rear direction.

FIG. 14 is a diagram showing a relationship between a pressure receiving portion and a rotating shaft in a conventional device.

FIG. 15 is a diagram showing a relationship between a wheel-side end of a lower link and a disk rotor in the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transverse link (lower link) 1a Wheel side end part 2 Compression rod (lower link) 3 Ball joint 3a Socket part 3b Spherical guide part 3c Screw part (projection part) 4 Knuckle spindle (wheel support member) 5 Bush 6 Ball joint 7 Shock absorber 8 Suspension spring 9 Knuckle arm 10 Tie rod 11 Upper link 12 Extension 13 Ball joint 16 Body side member 17 Disc rotor 18 Wheel 19 Dust cover L Link axis P1 Rotation center of ball joint P2 Mounting point at lower part of shock absorber ( (Reaction force input point) S Shock absorber axis Q Rotation axis during steering R Pressure receiving part L 'Link axis line when not turning P1' Rotation center of ball joint when not turning S 'Shock when not turning Absorber axis δ Offset amount

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroyuki Hayashi F-term in Nissan Motor Co., Ltd. 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa 3D001 AA02 AA12 AA17 AA18 BA03 DA04 DA05

Claims (5)

[Claims] 1. A lower end of a lower link is connected to a wheel support member rotatably supporting a wheel via a ball joint, and a lower portion of a suspension spring is connected to the lower link directly or via a shock absorber. In the front suspension device, the lower link and the wheel support member are connected by the ball joint. A spherical guide portion is rotatably inserted into a socket portion formed on the wheel support member and opened upward. A front suspension device wherein a wheel-side end of the lower link is fixed to a protruding portion protruding upward from the spherical guide portion. 2. The front suspension device according to claim 1, wherein an input point of a reaction force from the suspension to the lower link is vertically offset with respect to a link axis of the lower link. 3. A wheel supporting member for rotatably supporting a wheel, the wheel-side ends of two lower links are connected via respective ball joints, and one of the two lower links is connected to one of the lower links. 3. The front suspension device according to claim 1, wherein a lower portion of the suspension spring is connected directly or via a shock absorber. 4. The one lower link is a lower link on the front side in the vehicle longitudinal direction of the two lower links, and a wheel-side end of one of the lower links is formed by a reaction force of the suspension spring. 4. The front suspension device according to claim 3, wherein the inner wheel swings in a direction away from the other lower link when turning, and the outer wheel swings in a direction approaching the other lower link when turning. 5. The reaction force input point from the suspension is offset upward with respect to the link axis of the lower link, and the reaction force from the suspension spring is reduced by the reaction force from the suspension spring when the wheel is not steered. The front suspension device according to claim 4, wherein the front suspension device passes through a link axis of the link or the vicinity thereof.