JPS5921300Y2 - Stacked leaf spring with additional mass - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a stacked leaf spring for suspending an axle in an automobile or the like.

In an automobile suspension structure using stacked leaf springs, engine torque fluctuations cause the differential to swing around the axle, and the stacked leaf springs, whose center portion is attached to the axle, bend and resonate, causing so-called wind-up resonance.
It is a well-known phenomenon that vehicle body resonance is caused through the attachments, which is transmitted as unpleasant indoor noise, and is particularly avoided in passenger cars as unpleasant noise.

As an effective means of countering this, technology is often used to change the resonance point by adding additional masses to appropriate parts of the stacked leaf springs, suppress the resonance, and reduce and eliminate indoor noise. The mounting location is located at the abdomen of the unique vibration mode due to the resonance order and the stacked leaf spring configuration, that is, the vibration mode 1' shown in the first figure.
It is said that it is most effective to attach the leaf A' to the leaf A' corresponding to the abdomen A, and the same vibration damping effect can be achieved with the minimum mass.

However, as shown in FIGS. 2 to 4, the conventional additional mass attachment means is generally attached to a limited leaf portion by utilizing the original design configuration of the stacked leaf spring.

That is, the additional mass 4 is attached to the lower surface of the leaf through the clip 3 for preventing lateral slippage of the beam 72 shown in FIG. 2, and the mass of the same clip 3 as shown in FIG. Furthermore, FIG. 4 shows a configuration in which the small leaf end is shaped into a hollow cylinder and the hollow part is filled with an additional mass of the required mass, and each leaf part A' corresponds to the abdomen A of the above vibration mode. The additional mass attachment portion does not necessarily match, and the damping effect is weak.

Therefore, in order to obtain a vibration damping effect above a certain level, the mass of the additional mass inevitably becomes excessively large.

- If an additional mass anchoring hole is drilled near the above leaf A' portion in order to avoid the drawback of increased receding, the spring stress distribution will be impaired, which is an important problem that will reduce the spring function, contrary to improving the vibration damping effect. A problem existed.

In view of the above circumstances, the present invention provides a new structure that allows an additional mass to be attached to any desired leaf portion at any time without impairing the original function of a stacked leaf spring, and which solves the problems known in the art. The aim is to reduce and eliminate unpleasant interior noise, as well as promote weight reduction of vehicles.

The following will be explained based on examples.

5 to 7 show one embodiment of the present invention, in which FIG. 5 is a front view thereof, FIG. 6 is a BB' sectional view thereof, and FIG. 7 is a front view of an additional mass body, which has an equal mass and an equal shape. , two additional squares of equal size 4
are integrally fixed by spot welding or the like to both ends of the curved inner surface of a flat rectangular thin plate spring 9 that is curved with an appropriate curvature in the longitudinal direction, and the additional mass 4 is attached to a portion adjacent to the thin plate spring 9 on the opposite inner surface of the thin plate spring 9. A concave groove 8 is provided in advance parallel to the surface of the leaf spring leaf edge surface 2', which corresponds to the shape of the edge surface 2' of the leaf spring, and fits loosely with the edge surface 2' without any gaps. Additionally, the concave grooves 8 constitute an additional mass body.

The above additional mass body has its upper end shown elastically opened, and the edge surface 2' of the no. 72 and the concave groove 8 are fitted into each other. 2 and the additional mass body are engaged in the form shown in FIG. 6 so as not to be easily detached or displaced by external force.

In this way, since the additional mass body can be attached to any part of the beam 72, the center of gravity of the additional mass body can be very easily and accurately attached to the leaf A' portion corresponding to the abdomen A of the natural vibration mode of the stacked leaf spring confirmed in advance. It is clear that since they can be matched, the above-mentioned resonance can be suppressed very effectively.

Next, as shown in FIGS. 8 and 9, the thin plate spring 9 has a flat rectangular shape that is curved with an appropriate curvature in the longitudinal direction, and has a small circular protrusion 10 with a cross section shown in FIG. This is an embodiment of an additional mass body in which additional masses 4 having the same configuration as the embodiment are fixed together in a relative and intrusive shape, and the curvature of the thin plate spring 9 is reversed by the pressure of the small protrusion 10, and the accompanying elastic reaction force is The structure is such that the four-striped groove 8 and the leaf edge surface 2' are held together.

It should be noted that the material, size, mass, etc. of the additional mass applied to the present invention are sufficient if applied based on the conventional technology, and there are no special technical limitations.

As described above, the present invention can very easily and precisely align the center of gravity of the additional mass with the leaf portion corresponding to the abdomen of the natural vibration mode of the stacked leaf spring, and does not impair the spring function of the stacked leaf spring in any way. It is clear that the present invention exerts an effective vibration damping effect without causing any noise, and significantly contributes to the reduction and elimination of unpleasant noises in automobile interiors, which is a known problem.

Furthermore, the additional mass required to obtain the same vibration damping effect is reduced compared to the conventional technology, and the present invention has a useful value as it also has the secondary effect of promoting vehicle weight reduction.

[Brief explanation of drawings]

Figure 1: Vibration mode diagram of stacked leaf spring, 2゜3.4
Figures: Perspective view and front view showing the prior art, Figure 5: Front view of the embodiment of the present invention, Figure 6: BB' sectional view thereof, Figure 7: Diagram of the free state of the additional mass body, Figure 8 : Front view of another embodiment,
FIG. 9: Its CC' sectional view. Explanation of symbols, 1...Stacked leaf spring, 1'...
...Vibration mode, 2...Leaf, 2'...
...Leaf edge surface, 3...Leaf clip, 4
...additional square, 5...eyeball, 6...
...Axle mounting center, 7...Spacer
8... Concave groove, 9... Thin plate spring, 10
...It's a small protrusion.

Claims (1)

[Scope of utility model registration request] Two additional masses having the required mass are fixed to both ends of the curved surface of a rectangular thin plate spring curved in the long side direction, and furthermore, two additional masses having the required mass are fixed to the ends of the curved surface of a rectangular thin plate spring curved in the long side direction, and further, a part of the thin plate spring is attached near the contact area between the additional masses and the thin plate spring. Two grooves corresponding to the shape of the leaf edge surface are bored parallel to the surface and in directions facing each other, and the leaf edge surface and the groove are engaged by the elastic deformation reaction force of the thin plate spring. A stacked leaf spring with an additional mass featuring a closed structure.