JPS6131331B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spring, and more particularly to a polymerized spring formed by alternately overlapping and bonding layers of elastomer material such as rubber and metal plates.

Such polymerized springs are used in a variety of applications, such as as part of suspension systems for track bogies (railway vehicles);
The spring is normally mounted so that the rubber layer and metal plate are substantially horizontal so that the weight of the vehicle exerts only a substantially compressive force on the rubber layer;
Relative lateral movement between parts of a vehicle suspension system can cause shear deformation (slippage) of the rubber layer.

In particular, when a relatively large shear deformation occurs, the upper rubber layer moves laterally with respect to the lower rubber layer, reducing the overlap between the upper and lower rubber layers (the lower rubber layer is only a small portion of the upper rubber layer). (If the spring only supports the compressive load), the effective cross-sectional area of the spring that supports the compressive load will be significantly reduced. It has been found that under such conditions, the combined load of the shear load and the compressive load applies a bending moment force to the rubber layer, and induced fracture occurs in the outermost rubber layer where the bending moment force acts maximum.

An object of the present invention is to provide a polymerized spring that resists failure due to fatigue even when subjected to shear loads and has a long service life.

The spring of the present invention is composed of alternating layers of rubber or elastomer material and metal plates bonded together,
The length of the layers in at least one plane of the longitudinal section extending approximately perpendicular to the plane of the rubber layer and the metal plate is shorter for the layers between the outermost layers than for the outermost layer; The thickness of the above-mentioned layers is such that the layer between the outermost layers is thinner than the outermost layer.

In one embodiment, the length of the layers in the longitudinal section uniformly decreases from the upper and lower outermost rubber layers to the central rubber layer, and these polymerized rubber layers are preferably unloaded. The longitudinal centers of the springs are aligned with each other so that the springs have a symmetrical shape in the longitudinal section when the springs are in this state.

In the operation of the spring when subjected to shear forces acting in the direction along the longitudinal section, the effective area of the spring for supporting the compressive load remains essentially unchanged, and equal to the area of the inner rubber layer). Therefore,
The effective area is not significantly reduced as in conventional polymeric springs where all rubber layers are of the same size.

Furthermore, compared to conventional polymerized springs, each rubber layer and metal plate in the spring of the present invention can move angularly with respect to the end face of the spring when subjected to a shear load. The bending resistance of any one layer is approximately proportional to the bending moment imparted by the resultant of external compressive and shear forces, which reduces the fatigue life of the spring of the present invention compared to conventional springs. It increases it.

In addition to the lengths of the polymerized rubber layers in the longitudinal section being different, the lengths of the rubber layers are also changed in one or more other longitudinal sections substantially perpendicular to the planes of the rubber layer and the metal plate, Therefore 1
The fatigue resistance of the spring against shear loads acting in the above directions may be increased.

The outer shape of the rubber layer in a cross section extending parallel to the metal plate may be arbitrary, such as rectangular, square, circular, elliptical, or polygonal. Further, the rubber layer may have a through hole extending in the thickness direction of the layer so that the rubber layer has a substantially ring shape in such a cross section, and the metal plate may also have a through hole extending in the thickness direction of the layer so that the rubber layer has a substantially ring shape in such a cross section. A through hole may be provided. However, in order to obtain a good fatigue life, it is better that neither the rubber layer nor the metal plate have through holes. The spring may include a passage communicating between the hollow cavity and the outside of the spring. The hollow cavity may be made airtight, and where such passageways are present, valves or seals may be provided to maintain the airtightness.

In a preferred embodiment, the rubber layer at the center (i.e., inner side) of the spring is relatively thin compared to the outermost rubber layer, and the thickness of the polymerized rubber layer is such that going from the center rubber layer to both outermost rubber layers, Therefore, it increases uniformly and gradually.

One embodiment of the present invention will be described with reference to the drawings. A polymerized suspension spring 10 for use in a suspension system for a railway vehicle is made up of a plurality of rubber layers 11 and metal plates 12 alternately bonded and fixed. 13 is a metal end plate.

The thickness of the rubber layer 11 is the center layer (i.e. the innermost layer) 1
1a to the outermost rubber layer, and the length of the rubber layer and the intervening metal plate, which is indicated by the distance in the left-right direction in FIG. 1, also increases from the central rubber layer 11a.
It gradually increases uniformly as it progresses from the outermost rubber layer to the end plate.

Throughout the entire length of each rubber layer as shown in Figure 1,
All the rubber layers have the same depth in the direction perpendicular to the paper plane of FIG. 1, and the metal plates are similarly formed. Central rubber layer 11a and central metal plate 12a
has a square outer shape (when viewed from the top and bottom of FIG. 1), and therefore the rubber layer 11 other than these
The metal plates 12 and 13 have a rectangular outer shape.

When the resultant force of shear force and compressive force acts on the spring, as shown in FIG. 3, the effective area of the spring that directly supports the compressive stress is the central rubber layer 11
remains substantially unchanged in the cross-section of a, which minimizes the effect of bending stresses on the outermost rubber layer, thereby making it possible to reduce Compared to this, it increases the lifespan against fatigue. From Figure 3, it can be seen that by using rubber layers and metal plates whose lengths gradually decrease from the outermost side to the center, all the rubber layers and metal plates can be replaced with conventional rubber layers and metal plates that all have the same dimensions. Compared to springs, they can move much more angularly with respect to the end plates, thus providing a more uniform bending stress distribution between all rubber layers, thereby increasing the fatigue life of the spring.

[Brief explanation of the drawing]

Figure 1 is a side view of the spring of the present invention under no load, Figure 2 is a side view of the spring under compression, and Figure 3 is a side view of the spring under compression and shear. It is a side view of a spring. 11...Rubber layer, 11a...Central rubber layer, 12
...Metal plate, 12a... Central metal plate, 13... End plate.

Claims (1)

[Scope of Claims] 1. A spring made of layers of rubber or elastomer material and metal plates that are alternately stacked and bonded together,
The length of the layer in at least one plane of a longitudinal section extending substantially perpendicular to the plane of the layer and the metal plate is shorter for the layer between the outermost layers than for the outermost layer. , and a spring characterized in that the layers between the outermost layers are thinner than the outermost layers. 2. The spring according to claim 1, wherein the thickness of the layers gradually increases uniformly from the center layer to the outermost layer. 3. The spring according to claim 1 or 2, characterized in that the length of the layers in the longitudinal section gradually decreases uniformly from the outermost layer to the central layer. spring. 4. In the spring according to any one of claims 1 to 3, each layer is arranged with longitudinal centers aligned with each other when viewed in the longitudinal section. Characteristic spring. 5. In the spring according to any one of claims 1 to 4, the layer or the metal plate, or both of these layers and the metal plate,
A spring characterized by having a through hole extending in the thickness direction of a layer or metal plate. 6. The spring according to claim 5, characterized in that the spring is provided with a hollow space. 7. The spring according to claim 6, wherein a passage is provided that communicates the hollow space with the outside of the spring. 8. The spring according to claim 6 or 7, wherein the hollow space is maintained in a substantially airtight state.