Anti-roll system for vehicles

An anti-roll device for a vehicle may include a lower arm disposed at both sides of a sub-frame, a rotation mounter formed at a middle portion of the sub-frame, a spring unit of which the middle portion is rotatably disposed at the rotation mounter, and a push rod connected to both sides of the spring unit and the lower arm, wherein the spring unit includes a plate spring of which both end portions are bent in opposite directions, an engagement portion having an engagement hole in the middle portion thereof is formed, and a bolt hole is formed at both ends thereof, an assistant spring that is disposed at both sides of the engagement portion and an assemble hole is formed in the middle portion corresponding to the engagement hole, and an engagement yoke engaged with the plate spring and the assistant spring and disposed on the rotation mounter.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2011-0132227 filed in the Korean Intellectual Property Office on Dec. 9, 2011, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an anti-roll device for a vehicle. More particularly, the present invention relates to an anti-roll device for a vehicle (Anti-Roll System) that uses a streamlined plate spring and an assistant spring to improve turning stability of a vehicle and to non-linearly increase roll rigidity depending on the size of a lateral load that is input.

2. Description of Related Art

Generally, a suspension system of a vehicle connects an axle with a vehicle body, and prevents vibration or impact that is transferred from the road from being transferred to the vehicle body while driving to enhance ride comfort.

The suspension system is to flexibly absorb the movement such as up/down vibration (bounce), rolling, pitching, and yawing of a vehicle body that are generated while driving a vehicle.

Particularly, the rolling adversely affects the safety while the vehicle turns, and a stabilizer bar is applied to reduce the side effect of the rolling in a conventional art.

However, a conventional stabilizer bar generates friction with a mounting bush that is mounted in a vehicle body to cause ride discomfort, and the roll rigidity of the stabilizer bar is uniform regardless of the size of a lateral load (i.e., roll angle), and therefore the stability of the vehicle cannot be guaranteed,

Also, there is a drawback that lubrication of rubber of a mounting bush is transformed or worn out to generate noise.

As shown inFIG. 1, an anti-roll device using a plate spring has been developed so as to resolve the problem of a conventional stabilizer bar.

Referring toFIG. 1, the anti-roll device has a lower arm103that is disposed at both sides of a sub-frame101and a rotating mounter105that is disposed at a middle portion of the sub-frame101.

A spring unit having a plate spring107is rotatably disposed at a middle portion of the rotation mounter105.

Respective ends of the plate spring107are connected to lower arms through a pushrod109.

That is, the anti-roll device is designed to use elastic force of the plate spring107to reduce roll of a vehicle, while not generating interference with a suspension system, and varies roll rigidity in proportion to a lateral load to effectively reduce the roll of the vehicle.

However, in a conventional anti-roll device for a vehicle as described above, the front/rear length of the plate spring107is long to generate interference with a vehicle body (e.g., TW: tire wall) or an adjacent component (e.g., TK; fuel tank) and there is a drawback in a layout aspect.

Also, because the entire length of the plate spring107cannot be increased because of the layout, it is disadvantageous in terms of energy absorption capacity, and because a load input angle that is transferred from a tire (T) and the push rod109is large, there is a drawback that load transferring efficiency is low.

Also, there is a drawback that a bracket (B) for engaging the push rod109with the plate spring107needs to be prepared for an assemble angle.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing an anti-roll device for a vehicle having advantages of using a streamlines plate spring and an assistant spring to suppress a large amount of roll of a vehicle and increase roll rigidity along with the size of a lateral load that is input to improve driving/turning stability of a vehicle.

Also, Various aspects of the present invention are directed to providing an anti-roll device for a vehicle having advantages of applying a streamlined plate spring such that the energy absorption capacity is improved, the length of a front/rear direction thereof is reduced to eliminate interference, there is a merit in a layout aspect, and a load input angle with a pushrod is reduced to improve load transferring efficiency.

Further, Various aspects of the present invention are directed to providing an anti-roll device for a vehicle having advantages of directly engaging a pushrod with a plate spring such that the number of engagement components is reduced to be simple.

In an aspect of the present invention, an anti-roll device for a vehicle may include a lower arm that is disposed at both sides of a sub-frame, a rotation mounter that is formed at a middle portion of the sub-frame, a spring unit of which a middle portion thereof is rotatably disposed at the rotation mounter, and a push rod that is connected to both ends of the spring unit and the lower arm, wherein the spring unit may include a plate spring having an engagement portion including an engagement hole in a middle portion thereof, wherein both end portions of the engagement portion are bent in opposite directions toward the middle portion of the engagement portion along each of both lateral sides of the plate spring to may have a streamlined shape and a bolt hole is formed at both ends of the both end portions, an assistant spring that is disposed at the both lateral sides of the engagement portion and an assemble hole is formed in a middle portion thereof corresponding to the engagement hole, and an engagement yoke of which an upper portion thereof is engaged with the plate spring and the assistant spring through the engagement hole and the assemble hole via a bolt and a lower portion thereof is rotatably disposed on the rotation mounter.

The plate spring is connected to the push rod through a ball joint that is engaged with the bolt hole of the plate spring.

The plate spring is bent to form an “S” shape, wherein the plate spring is connected to the push rod through a ball joint that is engaged with the bolt hole of the plate spring.

The assistant spring is shorter than the plate spring.

The assistant spring is a plane plate spring that respectively contacts each of the both lateral sides in the middle portion of the plate spring, wherein two assistant springs forms one set, wherein the assistant spring is shorter than the plate spring.

The engagement yoke has a fork portion that is formed at an upper side thereof, and the plate spring and the assistant spring are received in the fork portion and fixed thereto via the bolt, and a bolt portion that is formed at a lower side thereof and is rotatably disposed on the rotation mounter.

The lower arm is connected to the other end of the push rod through a control link that is disposed to penetrate an end portion of the sub-frame.

The rotation mounter may include a bearing housing that is fixed on the middle portion of the sub-frame, and a bearing that is inserted into the bearing housing in a state that a bolt portion that is formed at a lower side of the engagement yoke is inserted into an inner race of the bearing.

An exemplary embodiment of the present invention uses the “S” type streamlined plate spring and an assistant spring such that roll rigidity is non-linearly increased depending on the size of a lateral load that is input and suppresses a roll of a vehicle against a large amount of roll to secure turning and driving stability.

Further, a streamlined plate spring is applied to improve energy absorption capacity and to reduce the length of a front/rear direction thereof such that interference between components is eliminated and there is a merit in a layout aspect.

A load input angle that is transferred from a push rod and a tire is reduced to improve load transferring efficiency, and a push rod and a plate spring are directly engaged to reduce the number of engagement components to be simple.

DETAILED DESCRIPTION

However, parts that are not related thereto will be omitted so as to clearly describe an exemplary embodiment of the present invention.

FIG. 2is a perspective view of an anti-roll device for a vehicle according to an exemplary embodiment of the present invention, andFIG. 3is an exploded perspective view of a spring unit and a rotation mounter that is applied to an anti-roll device for a vehicle according to an exemplary embodiment of the present invention.

Referring toFIG. 2, an anti-roll device for a vehicle according to an exemplary embodiment of the present invention non-linearly increases roll rigidity depending on a lateral load that is transferred to a vehicle body and flexibly suppresses a roll of a vehicle against a large amount of roll to improve driving and turning stability of a vehicle.

The anti-roll device for a vehicle includes a lower arm1, a rotation mounter3, a spring unit5, and a pushrod7.

The lower arm1is disposed at both sides of the sub-frame9through a mounting bush (MB) to be connected to one side of a knuckle (N).

The lower arm1is integrally formed with a control link11that is disposed to penetrate an end portion of the sub-frame9, and has a mounting bush (MB) formed together with a sub-frame9.

Further, as shown inFIG. 3, the rotation mounter3is fixed at an inner side of a middle portion of the sub-frame9.

The rotation mounter3has a bearing housing31that is fixed at the middle inside of the sub-frame9, and a bearing33is forcibly inserted into the bearing housing31.

Further, the middle portion of the spring unit5is rotatably disposed on the rotation mounter3.

Referring toFIG. 3, the spring unit5includes a streamlined plate spring51, an assistant spring52, and an engagement yoke53.

Both sides of the plate spring51are bent in opposite directions based on the middle portion thereof. Also, an engagement portion51ahaving an engagement hole H1is formed at the middle portion, and a bolt hole H2is formed at both ends thereof.

Here, the plate spring51is bent along an “S” shape to be streamlined.

Also, the plate spring51is engaged with a ball joint54that is disposed at one end of the push rod7through the bolt hole H2thereof.

The assistant spring52is respectively disposed on both side of the engagement portion51aof the plate spring51, and an assembly hole H3is formed at the middle portion of the assistant spring52corresponding to the engagement hole H1.

The assistant spring52is a plane plate spring that contacts both side surfaces of the engagement portion51athat is formed in the middle portion of the plate spring51, and two springs52forms one set.

Also, the length of the assistant spring52is shorter than that of the plate spring51.

The assistant spring52is disposed at both side surfaces of the engagement portion51aof the plate spring51in an exemplary embodiment of the present invention, but it is not limited thereto, and four springs52can be applied thereon so as to increase the overall rigidity of the spring unit5, and more springs can be applied if necessary.

Also, an upper portion of the engagement yoke53is engaged with the plate spring51and the assistant spring52through a bolt, and a lower portion thereof is disposed on the bearing33of the rotation mounter3.

That is, the engagement yoke53has a fork portion53athat is formed at an upper side and a bolt portion53bthat is formed at a lower side.

The assistant spring52is disposed at both sides of the engagement portion51aof the plate spring51, and the springs52and51are engaged on the fork portion53athrough a bolt.

Further, a bolt portion53bthat is formed at a lower side of the engagement yoke53is engaged with the bearing33of the rotation mounter3, and the bolt portion53bis inserted into an inner race33aof the bearing33to be fixed by a nut (B) together with a washer (W).

The pushrod7connects both end portions of the streamlined plate spring51with end portions of the control links11that are respectively connected to a lower arm1.

One end of the pushrod7is connected to an end portion of the plate spring51through a ball joint54, and the other end thereof is connected to an end portion of a connecting rod11of the lower arm1through a ball joint55.

As shown inFIG. 4, an anti-roll device for a vehicle as described above uses the streamlined plate spring51such that the entire length is increased, energy absorption capacity is increased, a span (S) of a front/rear direction is reduced, interference between surrounding components is prevented, and there is a merit in a layout aspect.

Also, a load input angle (0) that is transferred from the pushrod7and the tire is decreased to improve load transferring efficiency, and the pushrod7is directly engaged with the plate spring51through the ball joint54to reduce the number of engagement components.

Hereinafter, referring toFIG. 5andFIG. 6, operations of an anti-roll device for a vehicle will be described.

That is, as shown in “S1” ofFIG. 5, when a vehicle body hits a bump equally on both sides, connecting rods11of both sides push the push rod7in an inner direction of the vehicle body.

Then, the streamlined plate spring51that is mounted on the rotation mounter3through the engagement yoke53is rotated in a clockwise direction together with the assistant spring52to absorb the bumping force.

When the vehicle body rebounds in the same condition, the connecting rods11of both sides draw each end portion of the pushrod7, and the plate spring51that is mounted on the rotating mounter3through the engagement yoke53is rotated in an anticlockwise direction together with the assistant spring52to absorb the rebounding force.

As shown in “S2” ofFIG. 5, when a vehicle body is operated with an inverse condition, the connecting rod11that is disposed on a bumping side pushes the pushrod7in an inner side direction and the connecting rod11that is disposed on a rebounding side draws the pushrod7.

Then, pushrods7of both sides move in a direction in which the rebounding is performed such that both ends of the plate spring51are pushed or drawn to bend the plate spring51.

Thereby, the plate spring51suppresses the roll of the vehicle body by elastic force thereof.

The bend amount of the plate spring51is increased while the lateral load that is input to the plate spring51is increased, and if the bend amount of the plate spring51is larger than a predetermined value, the assistant spring52supports the plate spring51to reinforce the roll rigidity of the vehicle body.

That is, as shown inFIG. 6, an anti-roll device for a vehicle according to an exemplary embodiment of the present invention non-linearly increases roll rigidity from a point “P” while a roll angle is increased such that a roll of a vehicle is suppressed and driving and turning stability is improved.