JPS60132140A - Fiber reinforced plastic laminated spring and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent cracks from developing at the periphery of a center hole and to check the progress of the cracks by a structure wherein every one layer or every one set of a plurality of layers of reinforced fibers are alternately directed in one side and in the other side or in the left side and in the right side of the center hole and laminated in the direction of the thickness of a laminated spring. CONSTITUTION:Before reinforced fiber bundles 6a, 6b and the like are wound on a bobbin 11, a lining-up guide member 15 is moved round in a plane intersecting with the direction of progress of the reinforced fiber bundles 6a, 6b and the like in a method that the bundles 6a, 6b and the like, which are longitudinally continuous and impregnated with resin, and, after being past through the lining-up guide member 15, wound on the bobbin 11 in order to be cured. After that, the bundles 6a, 6b and the like are wound on the bobbin 11 so as to keep clear of a pin 13 for the formation of a center hole 5, while narrowing the width of the bundles 6a, 6b and the like, and at the same time to alternately change the direction of keeping clear of the pin 13 every one layer of every one set of a plurality of layers in order to pile up. Due to the structure as mentioned above, cracks are hard to develop even at the periphery of the center hole, where higher stress develops, and the progress of cracks can be checked, even if the cracks develop.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an FRP leaf spring having a center hole and a method for manufacturing the same.

For example, a stacked leaf spring device used for vehicle suspension is constructed by stacking a plurality of leaf springs in the thickness direction. Figure 1 shows an example of this.
. . , and the center inserts the bolt 2 into the intermediate portion in the direction of the longitudinal force, thereby stopping each leaf spring l . . . from moving.

3.3 is the eyepiece member to be attached to the vehicle body side.

By the way, recently, lightweight FR has been used instead of the conventional steel plate.
There is a strong desire to put leaf springs made of P (fiber-reinforced synthetic resin) into practical use. FRP leaf springs mainly contain reinforcing fibers along the longitudinal direction, which are hardened with a matrix resin. When such an FRP plate spring is used in a stacked plate spring device as illustrated in FIG. It may be necessary to provide a hole for the bolt 2 to pass through.

FIG. 2 shows a conventional FRP leaf spring having a center hole 5. As shown in FIG. In other words, in the past, the center hole 5 was generally drilled by machining with a drill or the like after sheet forming.
In this case, since the reinforcing fibers are cut at the center hole 5, the strength of this portion is reduced. In addition, cracks tend to occur along the fibers starting from the center hole 5, and since the reinforcing fibers are unidirectional, the cracks tend to propagate along the direction of the fibers.

The present invention has been made based on the above circumstances.

The purpose is to provide an FRP leaf spring that can prevent the occurrence of cracks in the vicinity of the center hole, as well as prevent the growth of cracks, and a method for manufacturing the same.

The gist of the present invention is that in an FRP leaf spring that contains reinforcing fibers that are continuous in the longitudinal direction of the leaf spring and has a center hole, the reinforcing fibers are arranged on the left and right sides of the center hole in each layer or every number of layers. The FRP leaf spring is characterized in that each side is alternately distributed and stacked in the thickness direction of the leaf spring.

According to the above-mentioned FRP leaf spring, since the reinforcing fibers are not cut around the five center holes, it is possible to completely prevent the occurrence of cracks from the center holes. In addition, even if a crack were to occur, the reinforcing fibers are alternately distributed left and right before and after the center hole and intersect, which prevents the crack from propagating along the fibers and increases durability. is maintained.

Furthermore, the gist of the present invention is to provide a method for manufacturing an FRP board, in which a reinforcing fiber bundle continuous in the longitudinal direction and impregnated with resin is passed through an alignment guide member, then wound around a mold and hardened. In this method, before winding the reinforcing fiber bundle around a mold, the alignment guide member is rotated in a plane intersecting the traveling direction of the reinforcing fiber bundle, thereby narrowing the width of the reinforcing fiber bundle and forming a bin for forming a center hole. Wrap it around the above mold, avoiding it.

In addition, there is also a method for manufacturing an FRP leaf spring in which the direction in which the bottle is avoided is alternately changed for each layer or multiple layers.

According to this manufacturing method, the width of the entire reinforcing fiber bundle can be narrowed by rotating the alignment guide member, and the distances between each fiber can be narrowed to be approximately equal to each other in order to avoid the bin for forming the center hole. In other words, for example, when the reinforcing fiber bundle is forcibly pressed in the horizontal direction by a suppressing member that slides in the horizontal direction, or when the width is narrowed by sliding the mold horizontally to avoid the bin for forming the center, In this case, some of the reinforcing fibers come into contact with each other, and the resin is not sufficiently distributed between the reinforcing fibers, resulting in cracking along the direction of the reinforcing fibers.However, according to the method of the present invention, such problems do not occur. do not have.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 5. The FRP leaf spring 1 schematically shown in FIG. 3 has reinforcing fibers 6a..., 6b continuous in the longitudinal direction.
... and has all the center holes 5. These reinforcing fibers mea..., 6b... are alternately distributed in one layer or multiple layers on each side on the left and right sides of the above-mentioned center hole 5, and are stacked in the thickness direction of the plate spring, and are generally heat-cured. It is hardened with a synthetic matrix and a camphor resin 7.

To obtain the FRP leaf spring 1 described above, an apparatus shown in FIG. 4 is used as an example. In the figure, reference numeral 10 denotes a resin impregnation tank, which contains matrix resin 7' before hardening. In addition, a groove 12 corresponding to the shape of the leaf spring to be molded is formed on the outer periphery of the mold 11, and a pin 1 for forming a center hole is formed at a predetermined position.
3 is installed protrudingly. In this illustrated example, the mold 11 is divided into three equal parts in the circumferential direction so that each can be divided into three pieces.

Bins 13... are provided in 11c. Therefore, in the illustrated example, three leaf springs can be molded at the same time.

By rotating the reinforcing fiber bundle 6, the reinforcing fiber bundle 6 can be wrapped in the groove 12 a plurality of times. The reinforcing fiber bundles 6 are continuous in the longitudinal direction of the leaf spring, and are made of fibers such as roving fibers, carbon fibers, organic fibers, etc., and are formed into roving bundles 14...1-
Supplied from

The reinforcing fiber bundle 6 is fed out from the roving bundle 14, passes through the impregnation tank 1O, is impregnated with the matrix resin 7', and then passes through the alignment guide member 15'fI: the groove 12. It is designed to be wound up. The alignment guide member 15 is rotatable in a plane intersecting the traveling direction of the reinforcing fiber bundle 6, as shown by arrow A in FIG.

The direction in which the guide member 15 rotates is generally perpendicular to the traveling direction of the fibers, but may not be limited to the perpendicular direction depending on the case. It may also be designed to be rigid so that it can be rotated in consideration of the possibility of dropping it. In addition, the guide member 1
5, the width W of the hole through which the fiber bundle 6 passes (see Fig. 4)
is substantially matched with the groove 120 width.

In order to manufacture the FRP leaf spring 1 shown in FIG. 3 using the above-mentioned embodiment apparatus, when the reinforcing fiber bundle 6 passed through the impregnating tank 10 and soaked with resin is wound around the mold 11, the bottle 1 is
3. In the region 16 and 17 which is the end side of the leaf spring, the alignment guide member 15 must be rotated so that the reinforcing fiber bundle 6 spreads out to the width of the groove 12. Keep it in place (see Figure 4).

Then, as the fiber bundle 60 is wound closer to the bin 13 as the fiber bundle 60 is rotated, the guide member 15 is gradually rotated as shown in FIG. 5, thereby narrowing the width of the fiber bundle 6 wound around the groove 12. . Then, when the width is almost the minimum, bin 1
30 Pass through one side. Next, the guide member 15 is rotated in the direction to return to its original position, and the fiber bundle 60 is further wound while expanding its width. In the illustrated example, the above operation is repeated three times while the mold 1 rotates once. As illustrated in FIG. 4, for example, the fiber bundle is passed through the right side of the bottle in the case of the first bottle 13&, and the fiber bundle is passed through the left side of the bottle in the case of the second bottle 13b. It is preferable to alternately change the direction in which the fiber bundles are gathered during one rotation of the fiber bundle 11 for each bin. If the direction of avoiding the bottle is alternately switched in the circumferential direction of the mold 1, the fiber bundles will not be biased to one side during one revolution of the mold 1, and the fiber bundles will not be biased to one side, and the portions away from the bottle will be avoided. 16. Also in 17, the fiber bundle is placed in the groove 12.
It becomes easy to spread the 0 width to 2.

If the fiber bundle is wound by alternating the directions to avoid the bins 13 during one rotation of the mold 1 as described above, in the example shown in Fig. 4, the number of bins is an odd number (3), so it is 52. During the rotation, the direction to avoid the bottle is opposite to the above. The picks and fiber bundles 6 are alternately divided into nine layers on one side of the bottle 13 and overlapped in the thickness direction. After the fiber bundle 6 is stacked several times to several tens of times in this way, it is heated and hardened by JJO heating using a heater built into the mold 1 or by placing it in a heating furnace. After curing, it is cut into appropriate lengths 6 to obtain the FRP leaf spring 1.

According to the FRP leaf spring 1, since the center hole 5 can be formed without cutting the reinforcing fibers, cracks are less likely to occur even in the area around the center hole where high stress occurs. In addition, even if cracks occur, 5 reinforcing fibers with different directions 6 m', 6 b
Since they intersect in the thickness direction before and after the center hole 50, the propagation of cracks can be prevented and durability can be maintained.

In addition, when obtaining one FRP leaf spring, the width of the reinforcing fiber bundle 60 is narrowed by rotating the alignment guide member 15 to avoid the bins 13, so that the gaps between each fiber are almost evenly spaced. It can be made narrower to prevent local biasing of the fibers and unnecessary contact. For example, the width of the fiber bundle is narrowed by forcibly pressing the fiber bundle in the horizontal direction with a pressing member that slides in the horizontal direction, or by sliding the mold 1 in the horizontal direction.
If 3 is avoided, the fibers may come into contact with each other unnecessarily, resulting in a strength weakness. However, according to the method of this embodiment, since the width of the fiber bundle is narrowed overall, it is possible to prevent such problems from occurring.

In the above embodiment, the reinforcing fibers are distributed alternately into nine layers in the board thickness direction, but they may be alternately distributed into multiple layers by stacking two or more layers in the same direction.

Further, as a means for rotating the alignment guide member 15, it may be automatically rotated back and forth by mechanical force, or it may be rotated manually.

Further, as illustrated in FIG. 6, the reinforcing fibers may be divided left and right only in the vicinity of the center hole 50.

As described above, according to the present invention, it is possible to prevent the occurrence of cracks and the propagation of cracks around the center hole, and to produce highly durable FRP.
You can get leaf springs.

[Brief explanation of drawings]

Fig. 1 is a front view showing a stacked leaf spring device, Fig. 2 is a perspective view showing a part of a conventional FRP leaf spring in cross section, and Fig. 3 is a partial cross section of an FRP leaf spring according to an embodiment of the present invention. Fig. 4 is a perspective view showing the outline of the apparatus for manufacturing the FRP board, Fig. 5 is a perspective view of the alignment guide member in a rotated state, and Fig. 6 is a perspective view of the device according to the present invention. FIG. 7 is a plan view schematically depicting an FRP leaf spring showing another example. DESCRIPTION OF SYMBOLS 1... FRP plate spring, 5... Center hole, 6... Reinforced fiber bundle, 6a, 6b... Reinforced fiber, 7... Matrix resin, 1O... Resin impregnation tank, 1.・Type,
12...Groove, 13...Bin, 15...Alignment guide member. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 6

Claims (2)

[Claims] (1) In an FRP leaf spring that contains reinforcing fibers that are continuous in the longitudinal direction of the leaf spring and has a center hole, the reinforcing fibers are vibrated alternately on the left and right sides of the center hole for each layer or layers. An FltP leaf spring characterized by being separated and stacked in the thickness direction of the leaf spring. (2) In a method for manufacturing an FRP leaf spring, in which a reinforcing fiber bundle continuous in the longitudinal direction and impregnated with resin is passed through an alignment guide member, and then wrapped around a mold and hardened, the reinforcing fiber bundle is Before winding the reinforcing fiber bundle around the mold, the alignment guide member is rotated in a plane that intersects the traveling direction of the reinforcing fiber bundle, thereby narrowing the width of the reinforcing fiber bundle while avoiding the bin for forming the center hole. 11. Winding direction and avoiding pins
11! Alternatively, a method for manufacturing an FRP leaf spring, characterized in that multiple layers are alternately stacked.