JPS6258283B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a fiber-reinforced plastic leaf spring used in a vehicle suspension system.

One type of fiber-reinforced plastic processing method that has been used in the past is the hand lay-up method. In this method, tough fibers such as glass fibers and carbon fibers are formed into cloth or tape, and a thermosetting resin such as polyester is alternately laminated and cured. By integrally molding a leaf spring for a vehicle using this method, an extremely lightweight and strong leaf spring can be manufactured without using expensive molds. However, as shown in FIG. 1, since the front eye portion 3 and rear eye portion 5 of the leaf spring 1 are curved, it is difficult to charge the material, and the work efficiency is low because it is done manually. In addition, there were drawbacks such as large variations in quality.

In addition, when this leaf spring is formed by a filament winding method, for example, a method in which long fibers impregnated with resin are generally wound around a mandrel to form a desired shape and then hardened, the eye portions 3 at both ends, When composing the eye parts 3 and 5 in one piece, there is a drawback that the thickness of the eye part is half that of the other parts, resulting in insufficient strength. In this case, the front eye part 3 and rear eye part 5 are attached to the main body 2.
A process was necessary to combine the two.

The method of the present invention has been made in order to eliminate the drawbacks of the above-mentioned prior art, and is a method in which the front eye portion and the rear eye portion are integrally molded by the filament winding method, and furthermore, it is possible to prevent a decrease in strength in both eye portions. The purpose of the invention is to provide a method of arranging a predetermined fiber material between collars to be inserted into the front eye portion and the rear eye portion by a filament winding method with a predetermined distance between them. a step of setting the fiber materials arranged between the collars together with the collars in a predetermined molding die; and after closing the molding die, the inside of the mold is evacuated and the above-mentioned A process of eliminating air in the space where the fiber material and collar are arranged, and injecting a prescribed resin into the mold to integrally combine both collars together with the fiber material, and simultaneously forming the front eye part and the rear eye part. The method includes a step of forming the leaf spring into a predetermined leaf spring shape, thereby molding the front eye part and the rear eye part integrally with the leaf spring body and ensuring sufficient strength. This made it possible to significantly increase productivity.

Additionally, in addition to the above steps, a step of inserting reinforcing fibers such as hexes or mats in portions corresponding to the front eye portion and rear eye portion may be inserted in the middle of the filament winding operation, or a reinforcing fiber such as a mat shape may be inserted into the molding die. When a predetermined resin is injected and molded, the strength of the resulting leaf spring can be further improved by performing the molding operation while applying tension to the fiber material.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed explanation will be given based on drawings showing an example of implementation of the method of the present invention.

First, FIG. 1 is a front view of a leaf spring 1 for a vehicle manufactured by the method of the present invention.
Due to the structure of support at both ends, the leaf spring body 2 is made up of a leaf spring body 2 whose wall thickness is tapered at the center, and a front eye portion 3 and a rear eye portion 5 that are to be pivotally supported on the vehicle body. Collars 4 and 6 are inserted and fixed to the eye portion 3 and rear eye portion 5, respectively.

Filament winding device 17 used to manufacture such a leaf spring 1
As shown in FIGS. 2 and 3A, a front eye collar shaft 19 and a rear eye collar shaft 20 are held at a predetermined interval, and the collar 4 is attached to the shaft 19 and the collar 4 is attached to the shaft 20. The collars 6 are respectively fitted, and the device is rotated about a rotating shaft 18, and the roving or cross-shaped fiber material 7 fed out from the bobbin 23 is rotated as the device rotates. It is wound between both collars 4 and 6. Mats or cross-shaped fiber materials 8 and 9 for reinforcing both eye portions 3 and 5 are inserted in a U-shape around both eye portions 3 and 5, respectively, as shown in FIGS. 3B and 3C. It gets caught up in the fiber material 7.

Next, the filament-wound fiber material 7 is placed in the lower mold 12 of FIG. 3D together with the collars 4 and 6 and the removable shafts 19 and 20.
is set to During this setting, in order to form the tapered portion of the leaf spring main body 2, a fiber material 10 cut into a predetermined length from a fiber material previously formed in the shape of pine, cloth, tatami weave, etc. in a separate process is inserted. .

In addition, tension mechanisms 13 and 14 including springs and the like for applying tensile force to the fiber material via shafts 19 and 20 are provided on the lower mold 12 at opposing positions.

When the upper mold 11 is lowered as shown in FIG. 3E while the fiber material 7 remains under the tensile force due to the action of the tension mechanisms 13 and 14, the fiber material 7 bends due to the curvature of the mold. At this time, the collars 4 and 6 are aligned with the axis 1.
Since it is also possible to rotate (rotate) around 9 and 20, there is no risk of problems such as breakage of the fiber material 7 due to local friction due to the above deformation at the contact portion with the fiber material 7. . As the collars 4 and 6 revolve around the rotation axis 18, they also rotate around the axis 19,
It is also possible to rotate around 20 degrees.

After the fiber material 7 is set in the mold,
A vacuum device (not shown) evacuates the air inside the mold through a vacuum gate 15, and the inside of the cavity in which the fiber material 7 and the like are placed is evacuated. Such vacuuming eliminates problems such as air being mixed into the molded product (leaf spring) and deteriorating its quality. After that, a predetermined molding resin such as polyester, vinyl ester, epoxy, etc. is injected through the resin injection exit gate 16, and heated, molded, and hardened to bond the fiber material 7, thereby forming the desired leaf spring. It is molded.

Therefore, according to the method of the present invention, the collars to be inserted into the front eye part and the rear eye part are used as one part of the mold.
This means that the process of inserting a collar can be completely omitted. In addition, in the existing filament winding method, only the leaf spring body 2 could be formed due to insufficient strength in the front eye and rear eye parts, whereas in the present invention, the front eye part and the rear eye part were reinforced. Since the fibers can be inserted during the filament winding process, it has become possible to integrally mold the leaf spring including the front eye and rear eye. Furthermore, since the present invention does not require the joining process of the front eye part and the rear eye part, as compared to the conventional hand lay-up method, the molding time can be significantly shortened, and the productivity can be significantly improved. It was done.

In the above method, the reason why the fiber material 7 is hardened and hardened with resin while applying tensile force is to increase the strength of the product. In other words,
By applying tensile force to the fiber material, straightening the fiber material, and eliminating tangles and sagging of the fiber material, products with high strength, rigidity, and fatigue strength can be obtained. In addition, Fig. 4 A and B
2 shows a state in which a weft thread 22 is passed through a warp thread 21 (roving) to create a matte, cloth or tatami weave. In the present invention, the materials obtained in this way can be used as the fiber material 7 and as the reinforcing fibers 8, 9, and 10.

Further, although the specific example illustrated above is the most preferable example for implementing the method of the present invention, the present invention is not necessarily limited thereto, and various modifications and improvements can be made based on the knowledge of those skilled in the art. It can be implemented in For example, in the middle of filament winding, the front eye part 3 and the rear eye part 5
Although the fiber materials 8 and 9 are inserted to reinforce the structure, it is also possible not to insert the fiber materials 8 and 9.

Furthermore, although tension was added to the fiber material in the mold before resin injection and then cured to improve the strength of the product, it is also possible to add no tension. Furthermore, the collars 4 and 6 inserted into the front eye portion and the rear eye portion not only revolve around the rotation axis 18 but also revolve around both collar axes 19 and 2.
Although local friction of the fiber material 7 was prevented by rotating around 0, it is of course possible that the fiber material 7 does not rotate.

As detailed above, in the method for manufacturing a leaf spring according to the present invention, the leaf spring including the front eye part and the rear eye part can be efficiently molded in one piece without any quality variation, compared to the conventional hand lay-up method. It can be molded in an extremely short time. Further, since the collars are insert-molded in the front eye portion and the rear eye portion, the step of inserting the collars can be omitted. Furthermore, by applying tensile force to the fiber material during mold setting and solidifying it, the strength of the product can be improved.
By inserting a reinforcing fiber material into the front eye portion and rear eye portion during filament winding, excellent effects such as the ability to increase the strength near both ends of the leaf spring can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a front view of a leaf spring, and FIG. 2 is an explanatory diagram of a filament winding situation in an embodiment of the present invention. 3A to 3E are explanatory diagrams of the first to fifth steps, respectively, showing an embodiment of the present invention. The first step is a filament winding operation, and the second and third steps are during the winding step. It is an explanatory diagram of each operation of inserting the reinforcing fiber material, the fourth step is mold insertion and tension mechanism, and the fifth step is mold clamping, resin injection, and molding.
FIG. 4A is an enlarged explanatory diagram showing the structure of the fiber material or reinforcing fiber, and FIG. 4B is the − in FIG. 4A.
FIG. 1: leaf spring, 3: front eye part,
4: Front eye part color, 5: Rear eye part,
6: Rear eye part collar, 7: Textile material, 11: Upper mold, 12: Lower mold.

Claims (1)

[Scope of Claims] 1. A step of arranging a predetermined fiber material between the collars to be inserted into the front eye portion and the rear eye portion by a filament winding method at a predetermined distance apart, and arranging the predetermined fiber materials between the collars. A step of setting the fibrous material in a predetermined mold together with the collar into a predetermined molding die, and after closing the mold, the inside of the mold is evacuated to remove the fibrous material and the collar. A process of eliminating the air in the space, and injecting a predetermined resin into the mold to integrally bond both collars together with the fiber material, forming a front eye portion and a rear eye portion at the same time, and forming a predetermined leaf spring shape. A method for manufacturing a fiber-reinforced plastic leaf spring, comprising the steps of: 2. During the process of arranging the fiber material between predetermined collars by the filament winding method,
2. The method according to claim 1, comprising the step of inserting reinforcing fibers such as cloth or matte into portions corresponding to the front eye portion and the rear eye portion. 3. When injecting a predetermined resin into the mold to integrally combine the fiber material and collar to form a predetermined leaf spring shape,
3. The method according to claim 1 or 2, wherein said forming is carried out while applying tension to said fiber material.