Technical F ield

The invention relates to a suspension component which prevents the vibrations formed on stabilizer bar to be transmitted to vehicle body by mounting the stabilizer bar that determines vehicle handling and driving attitudes, and which has the essential torsional and vibrational damping properties therefor.

More particularly, the present invention relates to a stabilizer bar (anti-roll bar) bush which assists the handling attitude of vehicle and provides driving comfort by preventing the vibrations formed on stabilizer to be transmitted to vehicle body by surrounding the torque stabilizer bar, that is an important element for independent suspension systems located in vehicles, with its rubber body.

P rior Art

Stabilizer bar is a suspension unit in which the adverse effects that can be transmitted to driver and passengers in vehicle are eliminated by damping the effects of various physical difficulties that significantly affect the driving quality such as drift in the road bends that can be encountered during vehicle cruising. T he vibrations are prevented to be transmitted to vehicle body while the vehicle continues to cruise in safe without drifting. For this, damping of the vibrations occurring in these region is provided by using elastomeric bushes in the suspension arrangements.

The mentioned elastomeric bushes have a wide usage area within vehicle. For providing a comfortable drive, they have supportive functions such as damping the vibrations occurring between stabilizer bar and chassis or in parts like control arms within the vehicle body, or preventing voice to be transmitted.

Thus, the main purpose of the bush is to prevent the vibration coming from the road to be transmitted to the vehicle cabin by isolating them. The anti-roll bar which can be described as a torsion bar allows the vehicle wheels to be pressed on road in each case to balance the side-tilt overing occurred by drifting of vehicle at bends. Thus, in order to be able to exhibit these behaviours expected from the bushes, they should be resistant against the compulsive physical conditions such as torsion and compression that occur during vehicle cruising and should maintain these functions for a long time. When a bush surrounds the stabilizer bar in order to be assembled, it has great importance that the pre-compression level of the stabilizer bar within the bush is kept under control and at desired level. Also, keeping parameters such as radial and torsional stiffness at certain levels is very important in terms of bush lifetime and driving comfort. For example, designing a rubber bush which allows the radial stiffness to increase and the torsional stiffness to be kept at lower levels is an important technical problem.

Although various approaches and different bush structures are introduced until today, there is not any solution that can fully meet the problem.

The stabilizer bar bush explained in document E P 1391333 comprises an outer shell, an intermediate shell, and as a result of overlaps between rubber body and stabilizer bar during assembly, the torsional stiffness is decreased. Here, all ability related to compressing of stabilizer bar within the elastomer bush is based on the amount of the rubber that compresses the bar T he stabilizer bar makes difficult the control of pre-compression level on it and a more homogeneous compression requirement to be arised. In this document is not mentioned about an approach regarding the compression applicability on the outer portion of the bush and the provision of the desired torsional stiffness.

In the document E P091 1 195, a rubber and metal bush structure for connecting a stabilizer bar to motor vehicle body is mentioned. This explained solution comprises a rubber element surrounding mentioned stabilizer and a metal shell. R ubber element comprises a stopping and a closing element fixed within mentioned metal shell. Here too, the amount of compression applied on the stabilizer bar and torsional stiffness also cannot be controlled.

In the document US 5520465, a rubber bush structure for the stabilizer bars in motor vehicles is mentioned. The solution explained here comprises two half shells that are connected to each other as one piece at the axial end by means of a mesh. At the edge where the mesh connections exist, these two half shells have one of the guiding elements, they are guided into predetermined closed position during mounting. As a result these two half shells can be vulcanized within a mould at 180 degree open position.

As a result, the require for a bush structure in which stabilizer bar is compressed both from inside to outside and from outside to inside thanks to developed technical properties and so, in which the stabilizer bar is packaged homogeneously causes the solution of the present invention to come up. Object and S hort Desc ription of the Invention

The aim of the invention to present a bush structure which, comprising at least one corner support piece at corner region and at least one middle shell and at least one rubber body that connects each other by surrounding all them, prevents the vibrations formed on anti-roll bar to be transformed to vehicle body by them and so is a significative factor in vehicle behavior regarding suspension at road bends and speed bumps and stabilizer bar is located to its cylindrical space located inside.

Another aim of the invention is to present a bush structure which comprises two different corner support pieces located at corner regions of a bush piece, on a plate shaped-middle shell that forms a part of a cylinder. Another aim of the invention is present a bush structure which comprises two outer middle shells in order to apply compression on the rubber body or on the outer rubber layer that is located between a middle shell and a corner support piece from not only inside also from outside and so, to obtain an homogenous compression as a result of the compression force applied from outside by means of a connection when it is mounted to vehicle with the stabilizer bar and besides, a gap between support pieces in the middle of the corner support pieces that are located at the corner regions.

Des cription of the F igures

In figure 1 , a perspective view of the present bush is given.

In figure 2, a perspective view regarding outer and inner structures of one half of the present bush is given. In figure 3, a front view of the bush whose perspective view is given in figure 1 is given. In figure 4, sectional view of one half of the present bush is given.

F igure 5 is a representative sectional view of the present bush s one embodiment where one end is attached with a rubber filler and the other end is open.

F igure 6 is a sectional view in which ratio of overlapping occurring inside rubber after assembly of stabilizer bar is depicted is given. R eference Numerals

10. Mount

1 1 . Mount piece

20. C orner region

21 . C orner support piece

22. G ap between support pieces

25. Middle shell

30. R ubber body

31 . R ubber inner layer

32. R ubber outer layer

40. Cylindrical space

50. Distance between bush pieces

60. Stabilizer bush outer diameter

70. R ubber inner layer inner diameter

x. Overlapping ratio

T. Horizontal axis

Detailed Desc ription of the Invention

The present invention is a stabilizer bar bush (10) which helps vehicle handling attitudes and prevents vibrations formed at anti-roll bar to be transmitted to vehicle body by mounting the anti-roll bar that is an important element for independent suspension systems located in vehicle with its rubber body. Mentioned bush (10) provides anti-roll bar (that prevents vehicle to drift at road bends) to be connected to vehicle body.

The perspective view of present bush (10) is given figure 1. Basically, the present bush (10) comprises at least one corner support piece (21 ) at corner regions (20), at least one middle shell (25) and at least one rubber body (30) that connects each other by enclosing them. Mentioned corner support pieces (21 ) are plastic and middle shells (25) is aluminum sheet metal. However, these components are rigid substrates and they could be obtained with different materials that could serve same function. C orner support piece (21 ) has a rigid structure according to the rubber body (30). Besides, since the material of middle shell (25) is aluminum or steel, middle shell (25) is more rigid than other components.

The mentioned anti-roll bar is located to the cylindrical space (40) formed in middle portion of rubber body (30) that is preferably formed as two pieces for easy assembly. Mentioned bush (10) comprises at least 2 bush pieces (1 1 ). Mentioned bush pieces (1 1 ) may be as completely separated to each other (figure 1 ) or as one end is connected by adding with rubber filling while other end is open (figure 5). S ince mentioned bush pieces (1 1 ) are connected to vehicle chassis by enclosing anti-roll bar from bottom and top, these pieces can be called as lower piece and upper piece. T hus, the stabilizer bar which is kept between mentioned lower piece and upper piece completes the connection to vehicle body by means of clamp from outside of bush (10). S aid bush pieces (1 1 ) are positioned in symmetrical configuration to each other according to the horizontal axis (T) line seen in figure 3.

The basic function of the bush (10) is to prevent the vibrations coming from the road to be transmitted to vehicle cabin by isolating them. The anti-roll bar which can be described as a torsion bar allows the vehicle wheels to be pressed on road in each case to balance the side- tilt overing occurred by drifting of vehicle at bends. For this, the anti-roll bar makes a torsional motion within said bush (10). C ompensation of these torsional motions by the bush (10) having rubber body (30) is determinative for the comfort during vehicle cruising and bend passages. F or example; in the case when the bush (10) is excessively resilient to the torsional motion of the stabilizer bar, the vehicle will have a hard suspension and cause a knocking during speed bump passages at a level that driver feels it. In the case when the rubber allows too much to torsion, the vehicle gives softer response in the speed bump passages but it may be more side-tilt overing at the bend passages.

The perspective view regarding the outer and inner structures of one half of the bush (10) is given figure 2. In the present invention, mentioned middle shell (25) comprises two separated corner support pieces (21 ) that is located on the corner regions (20) of bush piece (1 1 ) on a middle cylindrical sheet (or sheet metal), the overlapping ratio between the rubber inner surface within middle inner portion and the anti-roll bar. T he sectional view in which ratio of the overlapping occurring at inner rubber of the bush after mounting of the stabilizer bar is depicted is given in figure 6. Here, it is seen that the stabilizer bush outer diameter (60) is greater than the rubber inner layer inner diameter (70). The difference between these two diameters defines pre-compression level of the inner rubber as well as specifying overlapping ratio (x). Mentioned overlapping ratio (x) is kept less compared to prior technical solutions and the function of absorbing the vibrations originating from the stabilizer bar is carried out in a healthier way by the technical capabilities brought by the present bush (10).

While the front view of the bush (10) whose perspective view is shown in figure 1 is given in figure 3, the sectional view of the bush piece (1 1 ) that constitutes one half of the present bush (10) is given in figure 4. In the prior art; the all capability regarding compression of stabilizer bar within bush (10) depends on the amount of the rubber that compresses the stabilizer bar within bush (10). However, in the present invention, by using two outer middle shells (25) preferably made of sheet metal and by using corner support pieces (21 ) located on the corner regions (20), a gap between support pieces (22) is formed between them. S o, while the bush (10) is assembled to the vehicle with the stabilizer bar, it is allowed thatthese two pieces approach to each other by decreasing mentioned gap between support pieces (22) as a result of the compression force applied from outside by means of clamp or similar connection and, compression is applied to the rubber body (30) or to the outer rubber layer located between middle shell (25) and corner support piece (21 ). Thus, since applied compression is obtained from also outside not only from inside, it is possible to provide more homogeneous compression to stabilizer bar. S imilarly, in the bush s (10) other half that surrounds mentioned stabilizer bar, there are same technical properties too. Besides, the distance between bush pieces (50) which is formed between mentioned bush pieces (1 1 ) allows the compression amount of the stabilizer bar within the present bush (10) to be kept both under control and at desired level when these two bush pieces (1 1 ) surround the stabilizer bar for assembly. T hus, during assembly, the stabilizer bar is also compressed from outside to inside by means of both gaps between support pieces (22) and distance between bush pieces (50) while it is compressed from inside to outside. S o, the stabilizer bar is packaged more uniformly within the bush (10).

In another configuration of the present bush (10), the rubber outer layer (32) and corner support pieces (21 ) and/or middle shell (25) are connected. T his provides a significant advantage for preventing the rubber outer layer (32) to be misplaced according to the corner support pieces (21 ) and/or middle layer (25). In the other words, the rubber outer layer (32) does not change its original axial position in the direction of the anti-roll bar s axis. T his means thatthe middle shell (25) maintains its position. T hus, it is provided the defined contact surface between outer surface and/or middle shell (25) and rubber outer layer (32) to be in a constant configuration.

These technical properties provide additional contribution and advantages at significant level. For example; since the bush (10) having this configuration is fixed by being compressed from both inside and outside and, since whole load is applied from not only inside also from outside thanks to that the inner surface of the inner layer is relatively larger, a more uniform load distribution is provided on the bush (10) and stabilizer bar and thus, its life time is increased.

As a require of assembly in place of the bush, the present bush (10) is configurated in the form of two bush pieces (1 1 ). However, it is also possible to be produced as a one-piece structure which surrounds the stabilizer bar by articulating from one edge. As a result, in the present bush (10), it is both important that rigid subcomponents (middle shell (25) and corner support pieces (21 )) or hard subcomponents located outside are composed of multiple pieces and, these have a construction that can apply compression from outside to the bush (10) and consequently to the stabilizer bar. Middle and outer components (elements) used in the bush (10) can be aluminum, steel, or plastic.

R ubber material allows the rubber body (30) to be formed by constituting both a rubber inner layer (31 ) and rubber outer layer (32) by filling between the middle shell (25) and corner support pieces (21 ). Thus, the bush (10) comprising a rubber body (30) helps radial stiffness to be increased and torsional stiffness to be kept at lower levels. The rigid substrates that are composed of two pieces in outer portion of the bush s (10) rubber body (30) are used as a support geometry for assemble the bush (10) to vehicle body. T he gap between support pieces (22) formed by these two rigid pieces allows a compression to be applied in the outer layer of rubber body (30). The distance in vertical axis, in the other words, the distance between bush pieces (50) or body in the bottom and top portion of the bush (10) allows a compression to be occurred on the outer rubber layer during assembly. Thanks to the rubber bush (10) inner diameter that is reduced -20% according to the diameter of the anti-roll bar, it is also assisted for formation of compression within both rubber inner layer (31 ) and rubber outer layer (32) of bush (10). As mentioned above, thanks to the compression occurred within inner and outer layers, it is allowed the torsional stiffness to be kept lower and life time of product to be long.