JPS5827411B2 - Layered leaf spring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stacked leaf spring device, and particularly to a leaf spring device having a small number of leaf spring plates and a large inter-plate friction force.

In stacked plate spring devices used in automobile suspension systems, reducing the number of spring plates to reduce weight reduces the frictional force between the plates and the dynamic spring constant, which improves ride comfort but reduces steering stability. The durability of the springs tends to deteriorate.

Conventional solutions to these problems include improving the damping force of the shock absorber, installing friction dampers, and stabilizers, but all of these methods involve increased costs.
Moreover, it is often difficult to install it on existing vehicles.

The present invention was made under the above circumstances, and its purpose is to increase the number of friction surfaces even if the number of spring plates is reduced in order to promote weight reduction, thereby reducing the frictional force between the plates. It is an object of the present invention to provide a stacked leaf spring device that does not substantially decrease in size and can be manufactured at low cost.

Hereinafter, the present invention will be described with reference to illustrated embodiments.

In the first embodiment shown in FIGS. 1 and 2, a plurality of
The spring plates 1, 2.3 (in the case of three shown in the figure) are formed, for example, into strips from spring steel, overlapped in the thickness direction, and threadedly engaged with a center bolt 4 passing through the center in the longitudinal direction. They are mutually tightened by nuts 5.

The first spring plate 1 has eye portions 6, 6 formed at both ends.
It is equipped with

The above configuration may be similar to that of a conventional device.

A plurality of friction plates 8 are provided between the center bolt 4 and the end of the spring plate, respectively, at positions closer to the end of the spring plate.

Each friction plate 8... is connected to each spring plate L2, 3 as shown in the figure.
It is interposed between the spring plates 1 and 1, and is also provided on the tension side of the first spring plate 1.

Mounting bolts 11 and nuts 1 are attached to the support 10 attached to the compression side of the third spring plate 3 by rivets 9 as an example of a fixing device.
It is tightened with a desired pressing force from 2...l.

As shown in FIG. 2, the mounting bolts 11 are positioned opposite to each other on both sides of the spring plate 1. I'm passing through.

The friction plates 8... have a relatively large frictional resistance with respect to the spring plates 1.2.3, and are made of, for example, a thin steel plate so as not to have substantial spring properties but also to have wear resistance. It is formed from.

When the device configured as described above is used in a suspension system for an automobile, the longitudinal middle part is connected to the axle side via an appropriate means such as a U-bolt, and the center part is connected to the axle side via an appropriate means such as a U-bolt. The parts 6, 6 are connected to the vehicle body side, and both ends move up and down with respect to the center part in a curved manner according to changes in load, and parts of adjacent spring plates closer to the plate ends slide into contact with each other. .

According to the above configuration, the friction plate 8 is located between the spring plates L2 and L3.
A friction plate 8 is also provided on the tension side of the first spring plate 1, and each friction plate 8 is slidable relative to the spring plate 1, 2.3. Therefore, the number of mutual sliding surfaces during the bending motion is 5, and the friction plates 8,
This is 2.5 times that of the conventional device that does not have 8.

In other words, if the number of spring plates is n1 and the number of sliding surfaces, that is, friction surfaces, is N, then in the conventional device N = n-1, but friction plates are interposed between each spring plate. In this case, it becomes N2(n-1).

A friction plate 8 is also placed on the tension side of the first spring plate 1.
If N is provided, N=2 (n-1)+1.

Therefore, since the substantial frictional force between the plates as a whole of the stacked plate splashing device is highly dependent on N, the greater the N, the greater the frictional force between the plates.

Therefore, even in a lightweight plate spring device with a small number of spring plates, the frictional force between the plates can be sufficiently increased by interposing the friction plates.

The following table compares and compares the experimental results for the stacked leaf spring device A of the present invention, a device B in which the friction plates 7, 7 are removed from the device of the present invention, and a conventional device C having spring characteristics similar to the device of the present invention.

As can be seen from the above table, although the device A of the present invention has half the number of spring plates and weighs approximately 80 times as much as the conventional device C, the frictional force between the plates is substantially the same as that of the conventional device C. It has characteristics.

Moreover, according to this embodiment, the tightening force can be variably set to a desired strength using the bolts 11 and nuts 12.

Furthermore, since it is equipped with bolts 11, it is possible to prevent horizontal displacement between the spring plates in the width direction and suppress rebound input, and it can also be used as a conventional clip used for these purposes, reducing the weight increase. can be prevented.

Note that the present invention is not limited to the above-mentioned embodiments, and for example, the number of spring plates can be arbitrarily set as long as it is two or more.

In addition, there is no need to provide friction plates at all mutually opposing parts of each spring plate, and by setting the number appropriately, the number of mutually sliding contact surfaces, and therefore the frictional force between the plates, can be adjusted to the desired magnitude. It is also possible to do so.

FIG. 3 shows an example of this, and the configuration is the same as in FIGS. 1 and 2 without the friction plate 8 that makes sliding contact with the tension side of the first spring plate.

As described above, the present invention provides friction plates made of thin steel plates between the spring plates between the center bolt and the end of the spring plate, and each friction plate is brought into sliding contact with each spring plate. Since it has a large number of surfaces, even if the number of spring plates is reduced and the weight is reduced, the actual frictional force between the plates can be maintained almost the same as before or even increased. can.

Therefore, it is possible to promote weight reduction without sacrificing handling stability, durability of the spring plate, etc., and it is possible to contribute to energy saving and resource saving.

Moreover, it can be implemented at a lower cost than when equipped with a stabilizer or a friction damper, and can be easily applied to existing vehicles.

Furthermore, the friction plate is slidably attached to the spring plate by fitting and pushing mounting bolts located on both sides of the spring plate in the width direction, and these mounting bolts Since the mounting bolts are prevented from moving relative to each other by being fitted and supported by a support member fixed to the By doing so, the frictional force can be variably set to a desired strength.

Further, the mounting bolts can also serve the same function as the clips, and are effective in preventing horizontal displacement of the spring plates and suppressing wind-up.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
A cross-sectional view taken along the line ■-■ in the figure, and FIG. 3 is a cross-sectional view showing another embodiment of the present invention. 1.2, 3... Spring plate, 4... Center bolt, 8...
...Friction plate, 10... Supporting member, 11... Mounting bolt.

Claims (1)

[Claims] 1. In a stacked leaf spring device in which a plurality of spring plates are overlapped in the thickness direction and tightened by a center bolt, the area between the center bolt and the end of the spring plate is made of a thin steel plate, and there is a gap between the overlapping spring plates. A friction plate is provided which is interposed between the spring plates and slidably contacts each of the spring plates, and furthermore, on both sides of the spring plate in the width direction, a supporting member fixed to the spring plate and each of the friction plates are provided. 1. A stacked plate springing device characterized in that a mounting bolt is provided which is inserted into the spring plate and also serves as a tightening member for tightening the friction plate to the spring plate.