JPS5894648A - Leaf spring for suspending vehicle chassis - Google Patents

Abstract

PURPOSE:To prevent the damage of the leaf spring by a method wherein a plate part and eye parts are formed integrally and the lower surface of the plate part, the outer periphery of the eye parts and laminated part are covered continuously by a protector plate attached by utilizing bolts and nuts or clips for reinforcing the eye parts. CONSTITUTION:The leaf spring 1 of a fiber reinforced synthetic resin is made by a method wherein the ends of a material of a fiber band impregnated with a synthetic resin is bent and piled under pinching a core metal thereat, thereafter, the plate part 2 and the eye parts 3 are formed integrally by press forming, while bushes 4 are fitted into the eye parts 3. The lower surface of the leaf spring 1 is provided with the protector plate 5 of an elastic material while the leaf spring 1 and the protector plate 5 are bound by the bolts 7 and the nuts 8 at the center of the plate 1 through a washer 6 and by the bolts 11 and the nuts 12 at the piled parts 9 through washers 10 respectively. Said protector plate 5 covers the lower surface of the plate 2, the outer peripheries of the eye parts 3 and the piled parts 9 continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a leaf spring for suspending a vehicle, which has a plate portion and a center portion integrally formed of fiber-reinforced synthetic resin.

Currently, in order to reduce the weight of automobiles, especially passenger cars and small cargo vehicles, there is a trend to change the leaf springs for vehicle suspension from steel plate to fiber-reinforced synthetic resin. The ends of the raw materials are folded back and overlapped by a core metal, and the plate part and the eyelet part are integrally formed by pressing and forming.In addition, in order to increase the strength of the eyelet part, the overlapping part mentioned above is formed with a pole donut L-. A plate spring made of fiber-reinforced synthetic resin that has been tightened and reinforced has been proposed as being practical.

However, on the other hand, it cannot be said that fiber-reinforced synthetic resin is necessarily strong against impact, and when using such a leaf spring made of fiber-reinforced synthetic resin, it is difficult to prevent the fiber-reinforced synthetic resin from being damaged by collisions with flying stones, etc. This leaves us with the problem of spring damage.

The above-mentioned problems can be solved by installing a protective plate made of an elastic material on a leaf spring made of fiber-reinforced synthetic resin. It has been proposed to perform heat welding at the same time as the molding of the leaf spring, or to join the leaf spring using an adhesive after the leaf spring is molded.

However, the protection plate installed by the above method,
Under harsh usage conditions, such as springs, where huge repeated stress is generated, there is a high possibility that they will easily peel off, and when joining, it is necessary to
It is necessary to perform surface treatment such as scissoring or chemical treatment to remove the mold release agent, which is not necessarily suitable as the treatment process becomes complicated.

On the other hand, the present invention aims to provide a leaf spring in which there is no need to worry about the protection plate peeling off easily and in which the protection plate can be installed without requiring a complicated treatment process. The installation of the boards was designed to prevent increases in fiber-reinforced synthetic resin costs and improve productivity. By making the protection plate so shaped that it continuously covers the lower surface of the plate, the outer periphery of the centerpiece, and the overlapping portion, it protects the lower surface of the leaf spring and protects the center and its vicinity from collisions with road curbs, etc. The purpose of this product is to prevent damage to the fibers before they occur.The feature is that the ends of the fiber bundle impregnated with synthetic resin are folded over a core metal, and then pressed and formed. ■ The leaf spring is made of an elastic material such as rubber or synthetic resin, and is bound to a synthetic resin leaf spring formed so as to continuously cover at least the lower surface of the plate portion, the outer periphery of the eyeball portion, and the overlapping portion. It's right there.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic front view of a leaf spring for vehicle suspension according to the present invention, with a part of the leaf spring being a cross-sectional view. The plate part 2 and the eyepiece part 3 are integrally formed by folding the ends of the metal core and folding them together and pressing them together, and forming the plate part 2 and the eyepiece part 3 into one body.A bush 4 is fitted into the eyelet part 3. Further, as is clear from FIG. 2a, which is a sectional view taken along the line A-A in FIG. is secured by a bolt 7 and a nut 8 through a washer 6 at the center of the plate part l, and by an overlapping part 9.
Similarly, they are configured to be bound together by a pole 11 and a nut 12 via a washer 10, respectively. The protective plate 5 is made of thermosetting resin such as urethane, nylon, polyacecool, polyethylene, NBR rubber, SBR rubber, thermoplastic resin, natural rubber, or synthetic rubber, and as shown in FIG. The shape of the plate part 2 is such that it continuously covers the lower surface of the plate part 2, the outer periphery of the eyeball part 3, and the overlapping part 9, and the binding force to the leaf spring 1 is strong. It is formed to be in close contact with the lower surface and the outer periphery of the eyeball part 3 or to apply initial pressure. The thickness of the protective plate 5 is 0.5 to 5II.
1 m, but in order to prevent damage to the eyeball part 3 and its vicinity due to collisions with road curbs, etc., the outer circumference of the eyeball part 3 and the connection point between the eyeball part 3 and the plate part 2 are The wall thickness of the covered portion is larger than that of the lower surface of the plate portion 2. Further, as shown in FIG. 5, the protection plate 5 has a through hole 13 in the center thereof through which the pole 1-7 is inserted, and a bolt 11 is inserted through the fiI location facing the overlapped portion 9. A through hole 14 is provided for this purpose. Note that the bolt 7 and nut 8 originally serve to position the leaf spring when attaching it to an axle (not shown), and the same effect can be obtained by replacing it with other binding tools, such as clips. . Further, the bolt 11 and the oak l-12 serve to increase the strength of the eyepiece portion 4 by binding the overlapping portion 9 as described above, and instead of this, a clip made of a bent steel plate is used. If a clip is used, it is desirable to form a recess on the outer periphery of the overlapping portion 9 into which the clip fits. Further, although not shown, a groove in the longitudinal direction may be provided on the first surface of the protection plate 5 in order to reduce the contact area with the leaf spring 1.

FIG. 3 shows another embodiment of the present invention, in which the protective plate 5 is provided with a convex portion 15 on the periphery of the eye 3 side of the nut 12, which is a part of the bolt 11-nut 12. The structure is designed to protect the body from flying stones, etc., and the other structure is exactly the same as that shown in Fig. 1. It goes without saying that when the aforementioned bolt 11 and nut 12 are fastened together with the bolt head facing downward, the bolt head is protected by the protrusion 15 instead of the nut 12.

In the embodiment shown in FIG. 21), the protection plate 5 in FIG.
It is configured to cover the sides as well.

FIG. 4 shows yet another embodiment, in which, in addition to the protection plate 5 disposed on the lower surface of the leaf spring l, a protection plate 16 different from the protection plate 5 is provided on the upper surface of the leaf spring l. By binding bolts 7 and nuts 8 and bolts 11 and nuts 12 as shown in , it is intended to more reliably avoid damage to the leaf spring l due to collisions with flying stones, etc. The protection plate 16 is made of the same material as the protection plate 5, and has a shape that continuously covers the upper surface of the plate portion 2 and the overlapping portion 9 of the leaf spring 1, as shown in FIG. At the same time, it is formed to be in close contact with the upper surface of the plate portion 2 or to apply initial pressure to the upper surface of the plate portion 2 so that the binding force to the plate spring 1 is strong. Note that the thickness of the protection plate 16 is desirably thinner than the thickness of the protection plate 5 so as not to increase the weight burden.

Further, the protection plate 16 is also provided with through holes 17.18 through which the bolts 7.11 are inserted, as shown in FIG.

As is clear from the above description, according to the present invention, by using a leaf spring made of fiber-reinforced synthetic resin in which the plate part and the center part are integrally formed, it is possible to obtain a lightweight leaf spring and The protective plate that protects the fiber-reinforced synthetic resin leaf spring, which is said to be relatively weak against water, is mechanically attached using fasteners such as bolt nuts or clips, so it is not easy to install the protective plate like in the past. A suitable leaf spring can be obtained without worrying about peeling and without requiring complicated processing steps.

In addition, according to the present invention, the fasteners such as bolt nuts or clips used for attaching the protection plate are bolt nuts or clips for reinforcing the center part, which are essential components of the integral leaf spring made of fiber-reinforced synthetic resin. Since fasteners such as clips can be used as they are, there is no need to increase the number of parts, which is extremely effective in suppressing cost increases and improving productivity.

Also, according to the present invention, the protective plate is shaped so as to continuously cover the lower surface of the leaf spring, the outer periphery of the center portion, and the overlapping portion, so that the lower surface of the leaf spring is protected against collisions with flying stones. Needless to say, damage to the centerpiece and its vicinity due to collisions with road curbs and the like can be prevented at the same time.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view, partially in cross-section, showing an embodiment of the leaf spring of the present invention. FIG. 2a shows a sectional view taken along the line AA in FIG. 1, and FIG. 21 shows the same sectional view according to another embodiment. FIGS. 8 and 4 are schematic front views, partially in cross-section, showing other embodiments. FIG. 5 is an enlarged front view of the protection plate shown in FIGS. 1.3 and 4. 1; Fiber-reinforced synthetic resin leaf spring 2; (of leaf spring 1)
Plate part 3; Eye part 51 (of leaf spring 1) Protective plate 9;
Overlapping portion (of leaf spring 1) 11; Bolt 12; Natsu Patent applicant Hiroshi Noguchi, patent attorney, Chuo Spring Co., Ltd.

Claims (1)

[Scope of Claims] 1a The ends of a material made of Viei impregnated with synthetic resin are folded back and overlapped by sandwiching the core bar, and the plate part and the eye part are integrally formed by pressure molding, and the overlapping part is A leaf spring made of fiber-reinforced synthetic resin is fastened with a fastener such as a bolt donut or clip, and is made of an elastic material such as rubber or synthetic resin.
Protective plates formed to continuously cover at least the lower surface of the plate portion, the outer periphery of the eyeball portion, and the overlapping portion are overlapped, and the protective plate is attached to the A leaf spring for vehicle suspension 2, characterized in that the leaf spring is bound to the fiber-reinforced synthetic resin leaf spring at an overlapping part. The leaf spring 3 for suspending a vehicle according to claim 1, wherein the plate spring 3 is formed to apply pressure. A plate spring for vehicle suspension according to claim 1, characterized in that a portion that covers a connection point is formed to have a wall thickness greater than that of the plate portion. A patent claim characterized in that a convex portion serving as a protective wall for the bolt head or nut is provided on at least one side of the periphery of the bolt head or nut 1 on the lower surface and on the periphery of the bolt head or nut 1 attached to the overlapping portion. Leaf springs for vehicle suspension as described in item 1 of the scope of