JPS6275144A - Spacer for laminated spring device - Google Patents

Abstract

PURPOSE:To prevent looseness of a U-bolt by dispersing surface pressure produced by tightening the U-bolt by a rubber-like elastic body, and lessening a strain change after repeated exciting. CONSTITUTION:An elastic body 17 and a metallic plate 19 are fixed to each other by adhesives or at the time of forming the elastic body 17, the elastic body is formed solidly with the metallic plate 19. On the other hand, a spacer 14 positioned midway comprises a pair of rubber-like elastic bodies 21 disposed on the upper and lower surfaces in the direction of thickness and a metallic plate 22 clamped by these elastic bodies 21. Accordingly, the surface pressure of a U-bolt is dispersed by the rubber-like elastic bodies, whereby even during repeated exciting, a strain change of the rubber-like elastic bodies is not caused to prevent the occurrence of looseness of the center clamp portion of a spring plate tightened by the U-bolt.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to automobiles! I! Tightening of the stacked leaf spring device for the rack is related to the spacer used in the section.

[Conventional technology]

Conventionally, in a stacked leaf spring device used in a suspension mechanism of an automobile, the longitudinal center portion of the spring plate, that is, the center clamp portion, is tightened in the thickness direction with a U bolt and a nut, and an axle is attached to the spring plate.

FIG. 5 shows an example of a conventional tightening structure using U-bolts. This illustrated example is mainly applied to large or medium-sized vehicles. In the figure, the center clamp portions of the spring plates 1 and 2 are tightened together in the thickness direction by a pair of U bolts 3 and nuts 5, and an axle 7 is attached thereto. Further, a center spacer 9 may be used to equalize the surface pressure due to tightening.

In the stacked leaf spring device having the above structure, the center clamp portion is strongly tightened by the U bolt 3 over a range of length β. This is a so-called rigid clamp. Konoshi Boruto 3
The load applied to the beam bolt 3 is extremely large, for example, in the case of a large vehicle, the load applied to the beam bolt 3 reaches several tens of tons.

[Problem that the invention seeks to solve]

Generally, when a leaf spring device is subjected to a load, the stress in the longitudinal center of the spring plate is highest. Moreover, since a center hole is formed in the center of the spring plate through which the center bolt is inserted, the stress at the center of the spring plate becomes even higher.

However, in the case of the above-mentioned JID clamp, if the U-bolt 3 is completely tightened, the length range will be completely integrated, and the tightened part will become a dead span and will no longer function as a spring plate. The stress in the center becomes significantly smaller. In addition, since a beam clamp is actually used when installing it on a car, the stress in the center of the spring plate is not taken into consideration in the design.

However, if the U-bolt 3 becomes loose for some reason, the center of the spring plate becomes untightened and bends, causing the stress at the center of the spring plate to become higher than the design stress, causing the spring plate to become untightened. may cause damage. Therefore, it is important to prevent the U-bolt 3 from loosening.

There are several possible causes for the U-bolt 3 to loosen, one of which is deformation (settling) due to compression of the spacer 9. Not only is a large surface pressure applied to the spacer 9, but also a large load is repeatedly applied to the spacer 9, so that it is easily deformed. If the spacer 9 weakens, it will lead to the U-bolt 3 becoming loose.

[Means for solving problems]

The present invention is a spacer provided in the longitudinal middle part of a spring plate that is tightened by a U-port, and a rubber-like elastic body provided on the side in contact with the spring plate and having a rubber hardness of JISA 90 or higher; and a metal plate to be polymerized. Further, if necessary, fibers may be embedded in at least a portion of the elastic body to strengthen the elastic body.

[Effect]

According to the spacer configured as described above, the surface pressure when the U-bolt is tightened is dispersed by the rubber-like elastic body, and appropriate rigidity can be obtained by the metal plate superposed on the elastic body.

By using an elastic body with a rubber hardness of 90 or more, the change in strain of the elastic body is small even after repeated vibrations, and the U-bolt can be prevented from loosening.

〔Example〕

In one embodiment shown in FIG. 1, the center clamping part of the spring plate 1.2 is restrained by a center bolt 10 and a nut 11 passing through the spring plate 1.2. This center clamp part is similar to the conventional product shown in FIG.
The bolts and nuts are tightened together in the thickness direction, and the axle is attached. Spring plate 1 of this embodiment
．． 2 is, for example, fiber reinforced plastic (FRP) IIJ
In Although,! You may also use a spring plate made by L. Further, the number of spring plates may be two or more.

And center spacer 13°14.
15 are provided. The upper and lower center spacers 13.15 have the same structure, each consisting of a rubber-like elastic body 17 provided in contact with the spring plate 1.2, and a metal plate 19 superimposed on this elastic body 17. Become. The elastic body 17 and the metal plate 19 may be connected by adhesive, for example, or the elastic body 1
They are fixed to each other by being integrally molded with the metal plate 19 during the molding of 7. In addition, the elastic body 17 is a spring plate 1°2
is glued to.

On the other hand, the spacer 14 located in the middle includes a pair of rubber-like elastic bodies 21 provided on both upper and lower surfaces in the thickness direction, and a metal plate 22 sandwiched between these elastic bodies 21. These elastic body 21 and metal body 22 are also preferably bonded to each other. The elastic body 21 is also glued to the spring plate 1.2.

A through hole for passing the center bolt 10 is formed in the center portion of these spacers 13, 14, 15.

The elastic bodies 17.21 are made of urethane rubber having a JISA hardness of 90 as defined by Japanese Industrial Standards. The stacked leaf spring device is vibrated in a state where an elastic body such as urethane rubber or hard rubber is compressed, that is, the U bolt is tightened, and the number of vibrations (number of repetitions) and the strain of the U bolt (axial force applied to the U bolt) are measured. ) When the changes are measured, they show a tendency as shown in FIG. In other words, regardless of the magnitude of rubber hardness (85 and 90), the strain hardly changes after the number of vibrations reaches approximately 50,000 times.

In other words, this indicates that the elastic body will not sag any further. Note that the U-bolt is designed to generate stress that does not cause it to deform.

Figure 3 shows the relationship between the rubber hardness before vibration and the strain change rate of the U-bolt after 50,000 vibrations. In other words, when the rubber hardness is around 85, the strain change in the bolt after 50,000 vibrations is quite large, 77% (reduction rate 23%), but when the rubber hardness is 90 or higher, the strain change after 50,000 vibrations is quite large. The strain change of the U-bolt is 84% (reduction rate 16%) or less, and the strain change tends to decrease by ml when the rubber hardness reaches 90.

In order to prevent the U-bolt from loosening, it is effective to prevent the elastic body 17.degree. However, if the elastic body 17.21 is made too hard, the effect of dispersing the surface pressure due to tightening will be weakened, so the rubber hardness of the elastic body 17.21 is 90 to 1.
A value up to 00 is appropriate.

Note that both ends of the elastic body 17.21 in the longitudinal direction are portions that are not tightened with U bolts, and these portions are attached to the spring plate 1.
．． It is better that the material is somewhat soft so that it can follow the changes in the vertical deflection of step 2. In this embodiment, instead of softening the material of this portion, both longitudinal ends 17a, 21 are used as shown in the illustrated example.
A is formed into a tapered shape, making the tip side easily flexible.

FIG. 4 shows another embodiment of the present invention, in which alII 125 such as glass cloth or organic 1 cloth is embedded in the elastic body 17.21.

By doing so, the elastic body 17.21 is strengthened and becomes more resistant to fading under high surface pressure.

This fiber 25 is attached to the region of the elastic body 17.21 that is tightened by the U bolt, that is, both longitudinal ends 178.21.
It is buried in the area except for a. Both ends 17a of the elastic body,
Since it is better for 21a to be easily flexible in order to follow the changes in deflection of the spring plates 1 and 2, 11t25 is not buried in this location.

〔Effect of the invention〕

According to the present invention, it is possible to prevent the center clamp portion of the spring plate tightened by the U bolt from becoming loose.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a center clamp part showing an embodiment of the present invention, FIG. 2 is a diagram showing changes in rubber hardness, FIG. 3 is a diagram showing the relationship between rubber hardness and strain change, and FIG. 4 is a diagram showing the relationship between rubber hardness and strain change. The figure is a sectional view of a center clamp section showing another embodiment of the present invention, and FIG. 5 is a side view showing the tightening section of a conventional stacked leaf spring device. 1.2... Spring plate, 13.14.15... Spacer, 17... Elastic body, 19... Metal plate, 21... Elastic body, 22... Metal plate, 25... ·fiber. Applicant's agent Patent attorney Takehiko Suzue Figure 1 (JISA) Third country

Claims (2)

[Claims] (1) A spacer provided in the longitudinal middle part of a spring plate that is tightened by a U-bolt, which is provided on the side in contact with the spring plate and has a rubber-like elastic body with a rubber hardness of JISA 90 or higher, and a spacer that is polymerized with this elastic body. A spacer for a stacked leaf spring device, characterized by comprising a metal plate. (2) The spacer for a stacked leaf spring device according to claim 1, wherein the elastic body is reinforced by embedding fibers in the elastic body.