KR100423297B1 - judder reduction system for lower arm - Google Patents

Abstract

The present invention relates to a device for reducing judder of a lower arm, which strengthens the rigidity of the bush installed in the lower arm to reduce the occurrence of judder during braking while the vehicle is running, and to weaken the stiffness of the bush to a normal state during normal driving. The object of the present invention is to improve the riding comfort even when passing an obstacle protruding from the road surface.

In order to achieve the above object, the present invention provides a ball joint (12) for supporting a knuckle arm, a front first mounting portion (22) and a rear second mounting portion (24) formed on the front member assembly (20) of the vehicle body. In the lower arm 10 having the front and rear bushes 14 and the vertical bush 16 coupled to each other, the front and rear bushes 14 of the lower arm 10 are braked in the front and rear bushes 14 when braking. It is characterized in that the pressurizing mechanism (30) comprising a pressing member (32), which operates to increase the rigidity of the force, and an operating cylinder (34) for imparting a working force to the pressing member (32).

Description

Judder reduction system for lower arm

The present invention relates to a judder reduction device of a lower arm, and more particularly, by installing a pressure mechanism interlocked with the operation of a brake device on the front side bush of the lower arm to stabilize the behavior of the lower arm, through a tire while driving. The present invention relates to a judging device for lower arms that can suppress vibration of the lower arm due to the impact force transmitted from the road surface.

In general, the suspension device provided in the vehicle is connected between the axle and the body to control the vibration or shock received from the road surface to be reduced or not directly transmitted to the vehicle body while driving, thereby preventing damage to the body and loaded cargo. In order to improve, it is composed of a chassis spring for mitigating the impact from the road surface, a shock absorber for controlling the free vibration of the chassis spring to improve the riding comfort, a stabilizer bar for preventing rolling of the vehicle, and the like.

In addition, the suspension device may be classified into various types such as the McPherson type, the wishbone type, the trailing link type, and the multi-link type according to the shape of the suspension arm constituting the suspension device.

On the other hand, as an example of the front wheel suspension of a conventional automobile, the McPherson suspension system includes a wheel assembly for mounting a tire, a knuckle arm for supporting the wheel assembly, a lower arm for rotatably supporting the lower end of the knuckle arm, and And a shock absorber disposed between the lower arm and the upper end of the wheel housing of the vehicle body to dampen the shock transmitted from the road surface to the vehicle body through the knuckle arm during driving.

Here, the lower arm 10 of the McPherson suspension device, as shown in Figure 1, the ball joint 12 for rotatably supporting the knuckle arm on one side, and the front member of the vehicle body to the front and rear of the other side, respectively It has a front and rear bush 14 and a rear vertical bush 16 that are engaged with the assembly 20.

In addition, the front member assembly 20 has a front side first mounting portion 22 and a rear side agent for fastening the front and rear bush 14 and the vertical bush 16 of the lower arm 10 by screwing, respectively. The two mounting portions 24 are formed to be spaced apart from each other.

Reference numeral 18 in the drawings is a mounting bracket which is coupled to mount the stabilizer bar on the lower arm 10.

However, when the brake is operated for deceleration while driving in a vehicle equipped with the above-mentioned McPherson suspension system, a so-called judder is generated in which the steering wheel and the vehicle body tremble. When braking while driving, vibration and noise are generated from the steering wheel or the instrument panel in the cabin.

In addition, the excitation force at the time of generation of the juder is transmitted to the axle by the front and rear force by the brake operation, the vibration generated by the juder is transmitted to the axle by the front and rear force generated by the initial brake operation, the vibration is again It is transmitted through the suspension system to the steering wheel of the steering system, and as a result, it is transmitted to the floor in the cabin through the corresponding part of the vehicle body on which the steering system is mounted.

On the other hand, Figure 2 shows the behavior of the lower arm 10, the front and rear force (F) according to the brake operation in the conventional McPherson suspension system and the front and rear modes of the suspension device to cause resonance by causing a large vibration in the steering wheel In other words, the lower arm 10 receives the front and rear force transmitted from the road surface at the ball joint 12 for installing the wheel assembly on which the tire is mounted. It shows the unstable behavior posture (shown by the arrow) which turns to the inside of the vehicle with reference to (14) (shown by the solid line in FIG. 2).

Accordingly, in order to suppress the occurrence of judder during braking, rubber having a high hardness is applied to the front and rear bushes 14 and the rear and vertical bushes 16 so as to hold the behavior of the lower arm 10. In this case, when the vehicle passes through an obstacle protruding from the road surface while driving, the front and rear bushes 14 and 15 are not properly absorbed by the impact, so that the comfort of riding It caused inhibition.

That is, the method for reducing the judder and the method for improving the riding comfort are mutually opposite aspects, it is difficult to satisfy both at the same time.

Accordingly, the present invention has been made in view of the above, and the rigidity of the bush installed in the lower arm is reduced to reduce the occurrence of judder during braking while driving the vehicle. An object of the present invention is to provide a judging device for lower arms that weakens and allows an improvement in ride comfort even when passing an obstacle protruding from a road surface.

The present invention for achieving the above object, the ball joint for supporting the knuckle arm, and the front and rear bushes coupled to the front first mounting portion and the rear second mounting portion formed on the front member assembly of the vehicle body, respectively, In a lower arm with a directional bush, a pressurizing mechanism including a pressurizing member acting to increase the rigidity of the front and rear bushing during braking, and an actuating cylinder for imparting an actuation force to the pressurizing member. And, the pressing member is provided with a protruding end of the curved shape to press the front and rear bush in the axial direction, the pressing mechanism is a brake device to apply the operating force to the pressing member when braking Hydraulic pressure is applied through the auxiliary pipe line branched from the main pipe line that generates oil pressure and supplies hydraulic pressure to the wheel cylinder of each wheel. It is characterized in that the pressing mechanism with a working cylinder and a connecting rod, a return elastic supporting the piston and the piston moved by the hydraulic pressure with a connecting rod coupled to the spring that is coupled to the pressing member is installed.

1 is an exploded perspective view showing a state in which a lower arm of a conventional vehicle is assembled to a vehicle body;

FIG. 2 is a plan view illustrating a posture in which the lower arm illustrated in FIG. 1 behaves in a judder phenomenon by an external force transmitted from a tire while driving; FIG.

Figure 3 is an exploded perspective view showing the installation state of the judder reduction device of the lower arm according to the present invention.

Figure 4 is a state diagram showing the configuration of the pressing mechanism shown in FIG.

FIG. 5 is an enlarged perspective view of the main portion of FIG. 3. FIG.

<Description of Symbols for Main Parts of Drawings>

10-Lower Arm 12-Ball Joint

14-rear bush 14a-seated groove

16-up and down bush 20-front member assembly

22-First mounting part 24-Second mounting part

30-Pressure mechanism 32-Pressure member

32a-projection end 34-operating cylinder

34a-connection rod 34b-piston

34c-return spring

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is an exploded perspective view showing the installation state of the lower arm judder reduction device according to the present invention, Figure 4 is a state diagram showing the configuration of the pressing mechanism shown in Figure 3, Figure 5 is a main part of Figure 3 The enlarged perspective view shows the same reference numerals as the same reference numerals as those in FIGS. 1 to 2 showing the structure of the conventional lower arm.

The lower arm judder reduction device of the present invention is installed on the front and rear bush 14 on the lower arm 10 of the McPherson suspension device, and is supplied to the brake wheel cylinder of each wheel when braking as shown in the drawing. It works by sharing hydraulic pressure.

That is, the lower arm 10 has a ball joint 12 rotatably supporting the knuckle arm on one side, and a front front and rear bush coupled to the front member assembly 20 of the vehicle body at the front and rear sides of the other side. 14) and a vertical bush 16 at the rear.

In addition, the front member assembly 20 on which the lower arm 10 is mounted, the front first side for fixing the front and rear bush 14 and the vertical bush 16 of the lower arm 10 by screwing, respectively. The mounting portion 22 and the rear second mounting portion 24 are formed to be spaced apart from each other.

In addition, the front and rear front and rear bushes 14 of the lower arm 10 are provided with a pressurizing mechanism 30 which is capable of increasing the rigidity of the front and rear bushes 14 by pressing them in the longitudinal direction when braking. The pressurizing mechanism 30 has a pressurizing member 32 which operates to compress the front and rear bush 14, an actuating cylinder 34 which imparts actuation force to the pressurizing member 32, and the actuating cylinder ( 34 is configured to include an auxiliary pipe line L 'sharing the hydraulic pressure generated from the brake device 40 at the time of braking and supplied to the wheel cylinder side of each wheel.

In this case, the pressing member 32 is formed in a curved shape to face the front and rear bush 14 of the lower arm 10 in the axial direction and is formed of a pair of protruding ends (32a) facing each other.

And, as shown in Figure 4, the operation cylinder 34, the connecting rod (34a) is connected to the pressing member 32, and is connected to the connecting rod (34a) and brake device 40 at the time of braking And a piston 34b that is pressurized and moved by the hydraulic pressure supplied to the wheel cylinders of the respective wheels from each other, and a return spring 34c that supports the piston 34b.

In addition, the brake device 40 is provided with a brake pedal 42 that is pressurized during braking, a brake booster 44 that doubles the pedal force applied to the brake pedal 42, and an actuation force from the brake booster 44. It consists of a master cylinder 46 for imparting working pressure to the braking oil and a main pipe line L disposed in communication between the wheel cylinders of each wheel from the master cylinder 46. Auxiliary pipeline L 'is branched and connected.

Meanwhile, as illustrated in FIG. 5, the front side front and rear bush 14 of the lower arm 10 has a casing portion formed in a hollow shape so as to mount the front and rear bush 14 at the distal end of the lower arm 10. (C) is fixedly installed, the front and rear bush 14 is in contact with the protruding end (32a) provided on the pressing member 32 of the pressing mechanism 30 so that it is easy to receive the pressing force therefrom. A circular seating groove 14a is formed.

The seating recess 14a is formed on the cushioning member 14d of rubber, which is vulcanized and fixed between the outer pipe 14b and the inner pipe 14c of the front and rear bush 14.

Reference numeral 18 in the drawings is a mounting bracket which is coupled to mount the stabilizer bar on the lower arm 10.

Therefore, the judder reduction device of the lower arm configured as described above has a braking pressure generated by the master cylinder 46 operated by the brake pedal 42 of the brake device 40 when the brake pedal 42 is pressed during braking. In the case of being supplied to the wheel cylinders installed on the respective wheels through the main pipe line L, the braking oil is supplied to the operation cylinder 34 of the pressurizing mechanism 30 through the auxiliary pipe line L '. The piston 34b in the working cylinder 34 is pressed to push the connecting rod 34a, and the protruding end 32a coupled to the pressing member 32 is moved back and forth according to the movement of the connecting rod 34a. The shock absorbing member 14d is compressed by contacting the seating groove 14a formed on the shock absorbing member 14d of the directional bush 14.

As a result, the shock absorbing member 14d in the front-side forward and backward bush 14 of the lower arm 10 is compressed and receives its rigidity, thereby increasing the rigidity of the shock absorbing member of the front and rear bush 14. Since 14d may limit the unstable behavior of the lower arm 10 during braking, the judder generated during braking in the lower arm 10 may be reduced.

On the other hand, since the judder reduction device is operated together with the brake device 40 only during braking, since the vehicle does not have any influence on the front and rear bush 14 located at the front side of the lower arm 10 during normal driving, the lower The front and rear bush 14 of the arm 10 can effectively attenuate the shock normally transmitted from the road surface.

As described above, according to the judging device of the lower arm according to the present invention, the pressurization for increasing the rigidity of the shock absorbing member 14d upon braking on the front and rear bush 14 of the lower arm 10 is achieved. By installing the mechanism 30, it is possible to prevent the unstable posture of the lower arm 10 generated by the front and rear force transmitted from the road surface to the lower arm 10.

In addition, as the unstable behavior generated by the lower arm 10 during braking is stabilized, judder transmitted through the lower arm system to the steering system and the floor of the vehicle body can be reduced. As a result, the riding comfort can be improved.

Claims (5)

Ball joint 12 supporting the knuckle arm, and a front and rear bush 14 coupled to the front first mounting portion 22 and the rear second mounting portion 24 respectively formed on the front member assembly 20 of the vehicle body. In the lower arm (10) with the up and down bush (16), The front and rear bush 14 of the lower arm 10 includes a pressing member 32 having a curved end 32a having a curved shape to press the front and rear bush 14 in the axial direction when braking; When braking, the hydraulic pressure is applied through the auxiliary pipe line L 'generated from the main pipe line L, which is generated by the brake device 40 and supplies hydraulic pressure to the wheel cylinders of each wheel so as to impart an operating force to the pressing member 32. A receiving cylinder 34, a connecting rod 34a coupled to the pressing member 32, a piston 34b connected to the connecting rod 34a and moving by hydraulic pressure, and the piston 34b. Judging mechanism 30 of the lower arm, characterized in that the pressing mechanism 30 is provided with a return spring (34c) to support the shot. delete delete delete The method of claim 1, The lower arm judder reduction device, characterized in that the seating groove (14a) for receiving the projecting end (32a) of the pressing member 32 is formed in the front and rear bush (14).