KR20090089768A

KR20090089768A - Suspension using the leverage

Info

Publication number: KR20090089768A
Application number: KR1020080059949A
Authority: KR
Inventors: 정만희
Original assignee: 정만희
Priority date: 2008-02-19
Filing date: 2008-06-23
Publication date: 2009-08-24

Abstract

The present invention is improved to reduce the cost to commercialize the suspension device using the continuously variable lever principle. After attaching the lever 420 to the chassis of the existing leaf spring-mounted vehicle and connecting one end of the lever to the hanger 400, an impact transmission plate 410 is installed to transmit an impact under the other end. have. As shown in the representative view, the shock transfer plate 410 is fixed to the axle or leaf spring. At this time, since the upper surface of the impact transfer plate 410 is convex toward the lever 420, the pressure contact point P , which is the point where the lever 420 and the impact transfer plate 410 contact, moves toward the support point 420a of the lever. Done. When the pressure contact ( P ) is moved toward the support point (420a) generates an effect such as the repulsive force of the leaf spring is increased. The present invention is a suspension device that realizes excellent ride comfort and driving safety at the same time regardless of the degree of unevenness of the road through a structure such as a weak spring constant for weak impacts and a strong spring constant for strong shocks.

Description

Suspension using the leverage

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device mounted on an automobile. Even though the spring is made of steel, which is generally used, the spring constant is changed in real time according to the strength of the impact. It relates to a suspension device to secure stability at the same time.

In general, a vehicle uses a suspension as a means for mitigating various shocks that may occur during driving. The suspension system is composed of a spring for mitigating the impact transmitted from the road surface, a shock absorber for absorbing the vibration of the spring, a stabilizer for preventing the vehicle from shaking from side to side.

Coil springs that are commonly used in conventional suspensions have a spring constant that does not change. Therefore, if you use a soft coil spring, the ride comfort is good, but there is a problem in driving stability, such as the car is inclined to one side by the centrifugal force on the curve road, and when a strong spring is used, it is advantageous to secure the driving stability of the car, but the riding comfort is inferior. have. The same is true for springs other than coil springs. That is, no satisfactory riding comfort and driving safety can be obtained at the same time by using any conventional spring.

Air springs have been used as a way to solve this problem to some extent. Air springs do not follow Hook's law due to the nature of the material, but follow Boyle-Charles's law ( PV / T = constant), so it is easier to secure ride and stability than steel springs. To see the difference, let's look at the graph of shrinkage of steel springs and air springs.

In this example graph, the steel spring shrinks in proportion to the weight applied, while the air spring shrinks less and less. The iron spring and the air spring both produce 3.4cm of deformation when loaded with a ton of load, but the length of the reduction when adding 4 tons of load is 13.6cm while the spring made of iron is only 8.9cm.

Looking at the characteristics of these materials, the following analysis will be possible. Even springs designed to provide the same ride comfort are more reliable than springs made of steel. The reason is that steel springs maintain the same spring constant value regardless of the degree of compression, while air springs have a larger spring constant as the compression progresses. In other words, it can be seen that the riding comfort and the driving stability can be obtained at the same time by using the suspension device in which the spring constant increases in proportion to the impact strength.

Since there is no clear theory on the repulsive force of an ideal vehicle suspension, the relationship between the cushioning distance and the repulsive force of the ideal suspension is based on the current road conditions and driving experience. It is desirable to absorb all impacts within a distance of approximately 5-6 cm even if a large impact such as when crossing the jaws. A comparison of the spring repulsive force for the ideal cushioning with other springs would look something like this:

In the above graph, the lower part of the ideal spring curve on the X-axis is a section showing excellent riding comfort by using a very soft spring, and then the sharply rising repulsion force means that the vehicle has high driving stability as it crosses the curve. Conventional steel springs or air springs are unable to realize rapid changes in repulsive force, such as ideal suspension springs.

The present invention is a suspension device that can cope with a weak impact with a weak spring constant and a strong shock with a strong spring constant, the strength of the impact from the wheel even when using a soft spring that can provide a comfortable ride for the driver Therefore, the suspension device can be appropriately responded to the purpose to provide a superior ride comfort and driving safety to the passenger at the same time. To achieve this goal, the present invention utilizes continuous and variable leverage. The problem solved by the present invention is to obtain an effect such that the spring constant changes depending on the strength of the impact while using a spring made of metal having a constant value that does not change.

Since it is impossible to realize the rapid change of the spring constant value due to the material characteristics of the existing spring, the present invention implements the repulsive force of the suspension desired by the designer through the method of obtaining the same effect as changing the spring constant using the lever principle.

The lever has a support point in the middle and an action point and strength points on both sides. Now let's call the distance between the force point and the support point α and the distance between the working point and the support point b . At the working point, place a spring ( W ) and send the impact ( F ) from the wheel to the force point. If Fα = Wb, the lever is in equilibrium. Therefore, if the distance ( b ) between the working point and the support point is constant, but the distance ( α ) between the force point and the support point is reduced, the reaction force ( W ) of the spring disposed at the operating point may be increased.

According to the present invention, the distance b between the working point and the support point is constant, but the distance α between the force point and the support point can be continuously changed so that the repulsive force W of the spring changes according to the strength of the impact. For this purpose, the upper surface of the iron plate (hereinafter referred to as impact transfer plate) that transmits the impact of the wheels to the lever is made convex toward the lever so that the contact between the lever and the impact transfer plate (hereinafter referred to as the press point) is increased as the pressure progresses. It is a feature of the present invention to allow it to continuously move toward the center (the supporting point) of. It is the present invention basically change (Δα) of α is larger than the amount of change (Δb) of b configure the suspension.

The device using the continuous and variable lever effect responds to weak shocks with weak spring constants, and strong shocks with strong spring constants, so that the driver can ride a wide range of shocks while using a soft spring that can provide the desired ride comfort. By appropriately coping, it is possible to simultaneously provide ride comfort and running stability regardless of the size of the uneven surface of the road.

In addition, since the suspension device realizes the real-time repulsive force that is most suitable for the impact caused by the unevenness of the road surface, the shock absorbing effect is particularly excellent in rough environments such as unpaved roads. Therefore, the present invention is ideal as a suspension device for a vehicle loaded with an ambulance or an article to be aware of breakage to ease the pain of the patient while driving.

The present invention, which can provide driving stability with improved ride comfort than any existing suspension device, is expected to reduce driver fatigue and increase durability of the vehicle. In addition, the present invention is expected to be able to reduce the maintenance cost than the air spring-equipped vehicle because of the relatively low cost and low probability of failure compared to the air spring.

The present invention is also excellent in the riding comfort improvement effect by the structure itself is shown in FIG. According to the present invention, the impact transmitted to the vehicle body is reduced because the lever axis of rotation of the wheel axis and the weight of the vehicle are transmitted in a straight line. Since the support point of the lever connected to the car body falls down to the ground when the wheels are springed up, the spring cannot absorb and greatly cancels the residual shock transmitted to the car body. In other words, the body lowering effect improves the riding comfort. The body lowering width is h1. Since the height of the upper surface of the shock transfer plate that transmits the impact from the wheel to the lever becomes lower toward the support point of the lever, the height between the press point ( P ) and the wheel shaft becomes lower as the pressure point ( P ) moves toward the support point of the lever. Something like going over a relatively low road surface overhang. The structural extinction of this shock is represented by h2. This phenomenon is equivalent to extinguishing part of the shock without passing it to the car or suspension.

Although the height above the protrusion having a height of H is almost unchanged, it can be seen from the figure of FIG. 6 that the shock absorbing effect of the device of the present invention is excellent. The buffering effect of the present invention can be expressed as the sum of (shock absorption + h1 + h2) of the spring. The existing suspension does not have a shock absorbing effect of (h1 + h2).

Suspension device of the present invention is the lower end coupled to the non-rotating wheel shaft of the wheel and the upper end of the impact transfer plate contacting the lever; A lever connected to one end of the shock transfer plate and connected to the chassis through a supporting point; It is configured to include a shock absorbing portion connected to the other end of the lever and absorbs the shock transmitted through the lever when the wheel swings up and down.

2 shows a model in which the present invention is mounted on an existing leaf spring. The support point 420a of the lever is fixed to the chassis 8 and the weight of the vehicle is transmitted to the ground through the support point 420a. It was connected with the leaf spring through the hanger (400) to absorb the shock on one side of the lever (420). The straight line distance between the support point 420a of the lever 420 and the point connected to the hanger 400 will not change. That is, the distance between the operating point of the lever 420 and the support point 420a is always the same. The impact transfer plate 410 in contact with the other side of the lever 420 is fixed to the non-rotating wheel shaft or the leaf spring of the vehicle. And the upper surface of the impact transfer plate 410 in contact with the lever 420 may be made of a curved surface of the convex shape toward the lever.

Since the configuration of the present invention is finished, it will be described the working principle. The weight of the vehicle is transmitted to the ground through the support point 420a of the lever 420. When the wheel swings up and down, the stronger the impact, the higher the shock transfer plate 410 pushes up the lever 420. At this time, since the top surface of the impact transfer plate 410 is convex toward the lever 420, the pressing point P , which is the point where the lever 420 and the impact transfer plate 410 abut, moves toward the support point 420a of the lever. Done.

As the pressing proceeds, the pressing point P moves toward the supporting point 420a of the lever 420, but the distance between the supporting point 420a and the operating point (the point at which the lever transfers force to the spring) does not change. Comparing this with Figure 1 showing the basic principle of the present invention will be expressed as follows. b is fixed unchanged but α is changed to α ' by the movement of the pressing point P

The value changes continuously.

The change in value has the same effect as the repulsive force of the leaf spring changes with the strength of the impact.

Basically, what is necessary is just to make the variation of ( alpha) value larger than the variation of ( b ) value. The phenomenon that the spring constant becomes larger as the impact becomes stronger is caused because the upper surface of the impact transfer plate 1 in contact with the lever 2 has a convex shape toward the lever 2. Through the continuous movement of the pressure point P where the convex top surface of the shock transfer plate 1 and the lever 2 come into contact with each other, the shock absorbing part (spring) exhibits weak repulsion force against weak impact and strong repulsion force against strong impact. It is the basic principle of the present invention.

The method illustrated in FIG. 3 is to replace one portion of the lever 520 with a leaf spring. Using a bracket 560 or a hanger fixed to the vehicle body induces the shock absorption of the leaf spring constituting one end of the lever 520. When the wheel bounces on impact, the impact acts as a force to press the bracket 560, which is a structure in which a side effect of increasing the traction of the other wheel is generated. The method of Figure 9 combines the spring and the lever. Since the impact transfer plate has the same shape, the repulsive force of the spring changes in real time according to the strength of the impact as shown in FIG. 2.

4 is a simple form in which the leaf spring is fixed to the chassis and the shock transfer plate 610 directly presses the leaf spring. Figure 4 is to remove the lever altogether so that the impact transfer plate 610 directly presses the leaf spring while the impact transfer plate 610 and the contact between the plate spring is a form that can move. It's the cheapest form.

Up to now, a description has been made of a suspension device in which a contact point of a shock transmitting plate and a lever approach toward a support point of the lever, but FIG. 5 specifically illustrates a form in which the contact is far from the working point. Figure 5 is characterized in that the iron plate 210 in the shape of the shock transfer plate of Figures 1 to 4 above the hinge bar 230 connected to the hinge shaft 231 fixed to the chassis.

The impact coming from the wheel is transmitted to the hinge bar 230 through the general steel plate and the impact of the hinge bar 230 is transmitted to the shock transfer plate 210. Then, the stronger the impact, the farther the contact between the impact transfer plate 210 and the hinge bar 230 will be away from the hinge axis 231. However, the change of the repulsive force of the spring according to the strength of the impact is the same as that of FIG. The reason why the position of the impact transfer plate 210 is disposed above the hinge bar 230 is to eliminate the movement of the pressing point from the iron plate 243 when the hinge bar 230 presses the spring. In this case, it is preferable to install the support 243 to prevent the left and right swing of the spring.

The present invention requires a stabilizer bar to prevent the vehicle from tilting to one side while driving on a curve road because the entire cushioning distance is short enough when the curved surface radius of the shock transfer plate head is increased, as illustrated in FIGS. 1 to 5. none. In addition, it is possible to use a sufficiently soft spring can reduce the number of leaf springs than the existing suspension. Of course, even using a strong spring like a conventional spring, you can achieve the same result as using a soft spring by adjusting the position of the support point of the lever.

One thing to note in the present invention is frictional resistance. Let's look at Figure 2. Friction resistance may occur between the lever 420 and the shock transfer plate 410. Since the lever support point 420a is fixed to the chassis and only rotates around the support point 420a, the impact transmission plate 410 is attached only to the non-rotating wheel shaft, so that only the vertical movement is performed. Therefore, the horizontal distance between the support point 420a and the impact transfer plate 410 is kept constant. When the wheel springs up, the contact point of the lever 420 and the impact transfer plate 410 is moved toward the support point 420a. At this time, because of the shape of the top surface of the convex impact transfer plate 410, the lever 420 and the impact transfer plate 410. This contact distance is slightly different. Since friction occurs due to the distance difference, it is desirable to take measures to mitigate such friction.

As a method for alleviating the friction, it is conceivable to insert a friction relaxation sliding plate (flat or slide bar) between the lever 420 and the impact transfer plate 410 or to make the impact transfer plate rotatable. When the sliding plate is inserted, friction is generated on both sides of the sliding plate, thereby reducing friction. Nevertheless, it may be a good idea to put grease between the sliding plate and the lever 420. The grease supply method is to drill a hole in the top of the lever 420 around the pressure point P where the lever 420 and the sliding plate contact each other when the vehicle is stopped, and attach a small container with grease to it. An appropriate amount of grease is supplied between the lever 420 and the sliding plate. The 5,000km driving test suggests that a normal syringe would not need to be replaced until it was abandoned. The form in which the shock transfer plate does not rotate requires a sliding plate as shown in FIG. It is also a good way to produce a form in which the lever 420 wraps the sliding plate so that the sliding plate does not escape during the driving of the car.

The method of implementing the ideal repulsive force shown in <Graph-2> is to use the spring as soft as possible and mount it so that the pressure contact P at the time of stopping the vehicle sags 1 to 2 cm below the horizontal as shown in the left figure of FIG. Just do it. The reason is that since only the tip of the lever 230 is in contact with the impact transfer plate 210 until the lever 230 is horizontal, only the weak repulsive force of the spring acts, but the center of the lever 231 reaches the horizontal position. Since the contact point P of the lever 230 and the impact transfer plate 210 is suddenly moved toward the center 231 because the repulsive force is very large due to the continuously changing lever action.

1 is a view showing the basic principle applied to the suspension of the present invention.

Figure 2 is an exemplary view applying the present invention to the existing leaf spring.

Figure 3 is a suspension device that allows the lever to absorb the shock by using one end of the lever spring.

Figure 4 is a suspension that absorbs shock by fixing one end of the leaf spring to the chassis.

5 is a model in which an impact transfer plate having a rounded curved portion is mounted directly on a spring.

6 is a diagram for explaining a reason for improving ride comfort.

** Description of the symbols for the main parts of the drawings **

1: Shock Transmitter 2: Crowbar

2: Supporting point of lever (rotary shaft) 3: Spring (shock absorbing part)

8: chassis 210: shock transmission plate

220: housing 230: hinge bar

231: hinge shaft 240: spring

241 flat plate 243 support

400: support 410: shock transmission plate

420: lever 420a: support point of the lever (rotation axis)

510: impact plate 520: lever

520a: support point of lever (rotation shaft) 560: spring support

610: impact plate 660: spring support

P: contact

Claims

A leaf spring having one end connected to the vehicle body and having a central portion fixed to the non-rotating wheel shaft of the wheel;

Hanger 400 for connecting the other end of the leaf spring and one end of the lever 420;

The lever 420 having a support point 420a fastened to a body of the vehicle;

An impact transfer plate 410 positioned below the other end of the lever 420 and having an upper surface contacting the lever 420 at the contact point P;

The impact transmission plate 410 is firmly fixed to the center of the wheel shaft or leaf spring;

As the pressurization proceeds, the impact transfer plate made of a curved surface having a top surface convex toward the lever 420 so that the contact point P, where the lever 420 and the impact transfer plate 410 abut, may move toward the support point 420a. Suspension consisting of 410

The method of claim 1,

Suspension device made of a curved surface of the lower surface of the lever 420 in contact with the impact transfer plate 410 is convex down

A lever 520 fastened to the body of the vehicle and having a support point 520a for supporting the vehicle weight;

A leaf spring configured between one end of the lever 520 and the support point 520a;

A support 560 fixed to the vehicle body and supporting the end of the leaf spring forming a part of the lever 520;

An impact transfer plate 510 in contact with the other end of the lever 520;

As the pressurization proceeds, the impact transfer plate made of a curved surface having a top surface convex toward the lever 520 so that the contact point P contacting the lever 520 and the impact transfer plate 510 can move toward the support point 520a. 510;

Suspension device characterized in that the shock absorbed by the leaf spring mounted on the lever 520 when the pressure is in progress

The method of claim 3,

Suspension device made of a curved surface of the lower surface of the lever 520 in contact with the impact transfer plate 510 is convex down

A leaf spring having one end fixed to the chassis by a support 660;

An impact transfer plate 610 positioned below the other end of the leaf spring and coupled to a non-rotating wheel shaft of the wheel;

As the pressurization proceeds, the shock transfer plate 610 of which the upper surface is convexly rounded to the plate spring so that the contact point P, which is in contact with the plate spring and the impact transfer plate 610, moves toward the support 660, is applied to the spring. Suspension device, characterized in that the direct pressure to absorb the shock