JPS6314210B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite leaf spring for vehicle suspension, which uses a leaf spring made of a steel plate for the parent plate and a leaf spring made of fiber-reinforced synthetic resin for the child plate.

Currently, in automobiles, especially passenger cars and small cargo vehicles, the trend is to change the leaf springs for vehicle suspension from steel plates to fiber-reinforced synthetic resin plates as part of reducing vehicle weight. In view of the fact that when a spring is used alone or as the parent plate of a stacked leaf spring, the strength of the center point at the end of the plate is insufficient, so we have used a leaf spring made of steel plate for the parent plate and a fiber-reinforced synthetic resin leaf spring for the child plate. A composite leaf spring using leaf springs 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 a leaf spring made of such fiber-reinforced synthetic resin is used as a child plate, collisions with flying stones that may occur when the car is running However, the problem of damage to the child plate due to the above-mentioned problems still remains.

The above-mentioned problems can be solved by installing a protective plate made of an elastic material such as rubber or synthetic resin on the child board. It has been proposed to perform heat welding at the same time as the child plate is formed, or to use an adhesive after the child plate is formed.

However, the protective plate installed by the above method is likely to peel off easily under severe usage conditions where huge repetitive stress is generated like a spring. It is necessary to subject the daughter plate to surface treatment such as sizing or chemical treatment to remove the mold release agent, which is not necessarily suitable as the treatment process becomes complicated.

On the other hand, in view of the above points, the present invention aims to provide a composite leaf spring in which there is no fear that the protective plate will easily peel off, and in which the protective plate can be installed without requiring complicated processing steps. By installing the protective plate using bolts-nuts or clips for center positioning and for preventing lateral slippage, which are essential components of composite leaf springs, it is possible to suppress cost increases and improve productivity. By forming the protective plate so that it continuously covers the lower surface of the child board and the center plate, it protects the bottom surface of the child board and at the same time prevents the center board from colliding with road curbs, etc. The purpose is to prevent damage to the end face of the child plate, and its characteristics include a child plate made of fiber-reinforced synthetic resin on the underside of the main plate made of steel, and rubber and synthetic resin on the underside of this child plate. Protection plates made of elastic members such as the The child plate and the protection plate are aligned and bound to the main plate with a center bolt or clip.

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

The composite leaf spring of the present invention has a plate portion 1 and an eyelet portion 2, as is clear from FIG. A main plate 3 made of steel plate, a child plate 4 made of fiber-reinforced synthetic resin, and a protective plate 5 made of elastic material are stacked together, and bolts 7 and nuts 8 are connected to each other through washers 6 at the center of the plate part 1. Therefore, both ends are tied together with clips 9. The protection plate 5 is made of thermosetting resin such as urethane, nylon, polyacetal, polyethylene, NBR rubber, SBR rubber, thermoplastic resin, natural rubber, or synthetic rubber, and as shown in FIG. 4
The lower surface of the child plate 4 is shaped so as to continuously cover the outer periphery of the center part 2 of the main plate 3, and the bonding force to the child plate 4 and the main plate 3 is strong. It is formed so as to be in close contact with the lower end and the outer periphery of the centerpiece 2 of the main plate 3 or to apply initial pressure thereto. Further, there is a gap between the protective plate 5 and the end face of the daughter plate 4, so that when the leaf spring is bent, the end face of the daughter plate 4 will not hit the inner surface of the protective plate 5 and damage the protective plate 5. Thus, a gap 10 of 15 mm or less is formed, which is the sliding allowance for the daughter plate 4. The protection plate 5 is used with a thickness of 0.5 to 5 mm, but in order to prevent damage to the end face of the daughter plate 4 due to collision with road curbs, etc., the thickness of the part covering the gap 10 is particularly reduced. 4 and the outer periphery of the eyeball part 2.

Further, as shown in FIG. 4, the protection plate 5 has a through hole 11 in the center for inserting the bolt 7, and recesses 12 for fixing the clip 9 at both ends of the lower surface. The bolts 7 and nuts 8 are used to bind the child plate 4 and the protection plate 5 to the main plate 3 as described above, but they also serve to position the leaf spring when attaching it to an axle (not shown). Similar effects can be obtained even if the bolts 7 and nuts 8 are replaced with clips.
The clip 9 is used to bind the main plate 3, daughter plate 4, and protection plate 5 and to prevent the plates from shifting laterally, as shown in FIG. 3a. Can be replaced with bolts and nuts. Further, although not shown, in order to reduce the contact area with the daughter plate 4, a longitudinal groove may be provided on the upper surface of the protection plate 5.

FIG. 5 shows another embodiment of the present invention, in which a spacer 13 is disposed between the main plate 3 and the daughter plate 4, and a squeaking sound is generated due to friction between the two plates 3 and 4, or the child plate This is designed to prevent wear on the top surface of 4.
The rest of the structure is exactly the same as that shown in FIG.

In the embodiment shown in FIG. 2b, the protection plate 5 described above is configured to cover not only the lower surface of the daughter board 4 but also the side surfaces of the main board 3 and daughter board 4.

Furthermore, in the embodiment shown in FIG. 3b, the protection plate 5
The clip is made wider than the child plate 4, and a baked rubber 14 is interposed between the clip 9 and the main plate 3 to avoid friction between the clip 9 and the main plate 3 and the child plate 4. be.

As is clear from the above description, according to the present invention, by using a plate spring made of steel plate for the parent plate and a plate spring made of fiber-reinforced synthetic resin for the child plate, the composite plate is lightweight and can be used practically. When the spring is completed, a protective plate that protects the child plate made of fiber-reinforced synthetic resin, which is said to be relatively weak against shock, is mechanically attached with bolts and nuts or clips, so it is not as conventional as before. There is no fear that the protective plate will peel off easily, and a suitable composite leaf spring can be obtained without requiring complicated processing steps.

In addition, according to the present invention, the bolts, nuts, and clips used to attach the protection plate are for center positioning and for preventing lateral slippage, respectively, which are essential components of the composite leaf spring. Therefore, there is no need to increase the number of parts, and it is extremely effective in suppressing cost increases and improving productivity.

Also, according to the present invention, the shape of the protection plate is
Since the bottom surface of the child board and the center part of the main board are continuously coated, it not only prevents damage to the bottom surface of the child board due to collisions with flying stones, but also protects the main board from collisions with road curbs, etc. Damage to the eye and the end face of the child plate can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view, partially in section, showing one embodiment of the composite leaf spring of the present invention. FIG. 2a shows a sectional view taken along the line AA in FIG. 1, and FIG. 2b shows the same sectional view according to another embodiment. FIG. 3a shows a sectional view taken along line BB in FIG. 1, and FIG. 3b shows the same sectional view according to another embodiment. FIG. 4 is an enlarged front view of the protection plate in this embodiment. FIG. 5 is a schematic front view, partially in cross-section, showing another embodiment of the composite leaf spring of the present invention. 1; Plate part (of main board 3), 2; Eye part (of main board 3), 3; Main board, 4; Child board, 5; Protective plate, 7; Bolt, 8; Nut, 9; Clip, 10 ; void.

Claims (1)

[Scope of Claims] 1. A child plate made of fiber-reinforced synthetic resin is provided on the lower surface of the main plate made of steel, and the lower surface of the child plate is made of an elastic member such as rubber or synthetic resin, and at least the lower surface of the child plate is made of elastic material such as rubber or synthetic resin. Protective plates formed to continuously cover the outer periphery of the center part of the main plate are stacked one after another with relative freedom of movement in the length direction, and the child plate and the protective plate are attached using center bolts or clips. A composite leaf spring for vehicle suspension, characterized in that the composite leaf spring is tied to the parent plate. 2. Claim 1, characterized in that the protection plate is formed so as to be in close contact with or to apply initial pressure to the lower end of the daughter plate and the outer periphery of the eyeball part. Composite leaf spring for vehicle suspension. 3. The protection plate is formed so as to create a gap of 15 mm or less between the protection plate and the end face of the daughter plate, which is a sliding allowance for the daughter plate. The composite leaf spring for vehicle suspension according to item 1. 4. Claims characterized in that the protection plate is formed so that its thickness is greater at a portion covering the gap than at the lower surface of the daughter plate and the outer periphery of the eyeball portion. The composite leaf spring for vehicle suspension according to item 1.