JPS605172B2 - Fiber-reinforced synthetic resin reinforcement beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reinforcing beam made of fiber-reinforced synthetic resin, and more particularly to a reinforcing beam having a specific structure with improved tensile strength.

It is well known to provide reinforcement by arranging a reinforcing beam on the back side of a plate-shaped body made of metal or the like.

The reinforcing beam is usually made of metal, and its both ends or the entire surface in contact with the plate-shaped body are joined to the plate-shaped body to reinforce the plate-shaped body.
In recent years, there has been a demand for weight reduction in transportation equipment such as automobiles. For this reason, there is a need to reduce the weight of reinforcing beams that are attached to the back of automobile exterior panels, such as doors, bonnets, and trunk covers.Also, even in areas where reinforcing beams have not been used in the past, plate thickness is being increased to reduce weight. In order to improve the strength of thinned plate-like bodies, it is necessary to attach lightweight reinforcing beams. The present inventors previously considered making reinforced beams using lightweight and high-strength fiber-reinforced synthetic resin, and focused on physical properties different from those of metals (for example, directionality of strength). We have seen that shaped reinforcement beams can be used effectively in certain ways,
I put it out. An example of the shape and usage of this reinforcing beam is shown in FIG. FIG. 1A is a sectional view of a plate-shaped body 2, which is a reinforced material, to which a reinforcing beam 1 is attached, B is a side view thereof, and FIG. 1C is a plan view of the back surface of the plate-shaped body 2. The reinforcing beam 1 consists of three flanges 3 and two webs 4 connecting them, and both ends of the reinforcing beam 1 have two joint pieces 5,
It is joined to the plate-shaped body 2 via 6. The joint pieces 5 and 6 are joined to the reinforcing beam 1 by means of a pet, and are joined to the plate-shaped body 2 by welding. This reinforcing beam 1 prevents the plate-like body 2 from deforming or breaking due to stress (indicated by arrow 7 in FIG. B) applied to the surface of the plate-like body 2. This reinforced beam made of fiber-reinforced synthetic resin consists of two or more flanges and a weep that connects them. The tip is located on the side of the reinforced material.

Although the web is located closer to the material to be reinforced than the midpoint of the height of the flange, it is not preferable for the web to be located at such a tip of the flange that it may come into contact with the material to be reinforced.
In the schematic cross-sectional view of the reinforcing beam shown in Figure 2,
Let the height of the flange be a, the inside of the web b, and the distance from the web to the tip of the flange on the reinforced material side.

The necessary condition is <C<amount a, preferably a≦C≦a, and particularly preferably a≦C≦a.
Furthermore, although the relationship between a and b is not particularly limited, the season a<b
<moderation is preferable, especially ami bSI. 9 is preferred.
However, in a part of the plurality of webs, C≧season may be satisfied, and further, each a and c may be different. for example,
The height of the flanges at both ends may be lower than the height of the flanges therebetween. The cross-sectional shape of the reinforcing beam is two H consisting of three flanges and two webs as shown in Figure 1.
In addition to those with a shape in which the molds are arranged side by side, there are two flanges and one
A cross section consisting of a web of books or 4 or more flanges and 3
It may have a cross section in which three or more H-shaped webs made of a book or more are lined up.

Further, by arranging these reinforcing beams and bonding their mutually contacting flanges with adhesive or the like, it is also possible to form an even wider reinforcing beam. For example, two reinforcing beams with a Japanese-shaped cross section consisting of two flanges and one web are lined up, the flanges that touch each other are glued together, and three flanges with a thick center flange and two It can be a reinforcing beam consisting of a web. When it is desired to further improve the strength of this fiber-reinforced synthetic resin reinforcing beam, this can be done by increasing the dimensions of the reinforcing beam, or by increasing the thickness of the flange or web of the reinforcing beam.

However, when the size of the reinforcing beam is limited, or when its weight should be as little as possible,
Alternatively, it is difficult to improve the strength using only these methods when trying to keep material costs from increasing as much as possible. By the way, the stress applied to the reinforcing beam is not applied equally to all positions of the reinforcing beam, and there are some parts where the stress tends to be concentrated. Of the stresses that are applied to the reinforcement beams mentioned above, the tensile stress that is considered to be the largest is the tensile stress that is applied to the end of the flange where the web is not unevenly distributed, that is, the end of the flange that is not located on the reinforced material side. Understood. For example, when a reinforcing beam as shown in Figure 1 is supported at both ends and a load is applied to the center, the part that breaks first is the flange end that is not located on the reinforced material side; It was not the joint between the flange and the web or the weave part that had been thought of. The inventor of the present invention investigated ways to improve the strength of the reinforcing beam without significantly increasing its size, weight, material cost, etc., and found that the flange end or its By improving the strength of the neighborhood compared to other parts,
It was discovered that the strength of reinforced beams could be improved. The present invention relates to this reinforcing beam, that is, the present invention relates to a fiber which is composed of two or more parallel flanges and a web connecting them, and has an H-shaped cross section or a parallel H-shaped cross section. In a reinforcement beam made of reinforced synthetic resin, the web is unevenly distributed to one side from the midpoint of the height of the flange and is not present in the flange weave, and the flange end on the side where the web is unevenly distributed is attached to the reinforced material. This is a reinforcing beam made of fiber-reinforced synthetic resin, characterized in that the strength of the flange end or its vicinity on the side that is not located on the reinforced material side is higher than other parts. Various methods can be considered to improve the strength of the flange rock or its vicinity.

However, the following three methods are preferred. One is to increase the cross-sectional area of the flange end, the other is to increase the density of reinforcing fibers, and the last is to arrange linear bodies that have better strength characteristics than reinforcing fibers. be.

For example, FIG. 3 shows a cross-sectional view of an example of a reinforcing beam made of glass fiber-reinforced unsaturated polyester resin, which has improved strength compared to the reinforcing beam having the shape shown in FIG. 1. In a reinforcing beam made of fiber-reinforced synthetic resin and consisting of three flanges 8 and two webs 9, the cross-sectional area of the flange end 10 on the side not located on the reinforced material side is increased.

FIG. 4 shows a sectional view of another example of the reinforcing beam of the present invention. That is, three flanges 11 and two webs 12
In the reinforced beam consisting of, the flange end 13 on the side not located on the reinforced material side has higher strength than other parts,
For example, the reinforcing fiber density is high, or linear bodies having superior strength characteristics than the reinforcing fibers are arranged. Comparison of the reinforcement effects of reinforced beams can be performed by measuring the deflection when a load is applied to the reinforced beam and calculating the amount of work from the measured value.

For example, if you support both ends of a reinforcement beam of a certain length, apply a load to the middle, measure the deflection of that part, and draw a graph with the deflection on the horizontal axis and the load on the vertical axis,
The area between the graph line and the machine axis is the amount of work. FIG. 5 shows one column of this exemplary graph. Deflect the horizontal axis〇,
The vertical axis is the load W of the reinforced beam before improvement. -W characteristics are represented by dotted line 1. Initially, the deflection and load of this reinforced beam are almost proportional to each other, but fracture occurs at the yield point 01, WI, and thereafter the load relative to the deflection decreases rapidly. The work of this reinforcing beam is between the dotted line 1 on the graph and the machine axis up to the deflection distance m that is above the yield point. It is expressed as the area surrounded by. The strength characteristic of the reinforcing beam of the present invention is that this area becomes large, and is represented by, for example, a straight line □ or a broken line m. That is, there is a line 0 where the slope of the graph line is large and the load at the yield point is large, and a broken line m (a part of m overlaps with 1) where the load at the yield point is large even if the slope does not change. Of course, what is required is that the amount of work be increased, and it is not necessarily necessary that the slope of the graph line be increased or that the load at the yield point be increased. For example, the strength characteristic of a certain reinforced beam is shown by the dashed-dotted line N
If it is expressed as [part of W overlaps with 1], the amount of work of this reinforced beam is clearly larger than the amount of work of a reinforced beam having the characteristic shown by the dotted line 1. In this case, the load at the yield point does not change, but even if the deflection increases within a certain deflection range thereafter, the load does not decrease. For example, the reinforcing beam having the strength characteristics represented by the dashed line N in the above graph is as follows.

That is, a highly elongated, high-strength linear body such as a piano wire is arranged at the flange end of the reinforcing beam made of glass fiber-reinforced unsaturated polyester resin, which is not located on the side of the material to be reinforced. Even after the glass fibers are cut at the yield point, the reinforcing beam retains the load without being cut because the piano wire has greater elongation than the glass fibers. Therefore, it exhibits strength characteristics as shown by the dashed line W in FIG.
In this way, the linear body disposed at the end of the flange on the side not located on the reinforced material side is suitably a high-tensile linear body that has a large residual stress in the yield region, has a large elongation, and is difficult to break. The type of fiber-reinforced synthetic resin constituting the reinforcing beam is not particularly limited.

Synthetic resins include unsaturated polyester resin, epoxy resin, vinylester resin, and other thermosetting resins.
Polyolefins, polyamides, polyvinyl chloride, and other thermoplastics may be used. As the reinforcing fibers, organic fibers such as glass fibers, carbon fibers, other inorganic fibers, and synthetic fibers are used. The reinforcing fibers are preferably long fibers, particularly continuous long fibers that can be arranged continuously in the length direction of the reinforcing beam. A particularly preferred fiber-reinforced synthetic resin is glass fiber-reinforced unsaturated polyester resin. Further, as the high-tensile linear body disposed in the reinforcing beam of the present invention, a metal linear body having a higher elongation than reinforcing fibers such as piano wire is preferable. As a reference example, the strength characteristic measurement results of one example of the reinforcing beam of the present invention are shown below.

Of course, the present invention is not limited to this specific example. Reference Example A reinforcing beam with a date-shaped cross section consisting of two flanges and one web was prepared.

a, b, c shown in Fig. 2 are respectively on the a=31.5 side,
b = 5 ribs, c = 6.5 ribs, the thickness of the flange was 5 skins, and the thickness of the web was 4 sides. The reinforcing beam is made of unsaturated polyester resin reinforced with longitudinally disposed glass fiber rovings with a glass fiber content of 57.5% by weight. These two reinforcing beams are placed side by side, the opposing flange surfaces are pasted together with epoxy resin adhesive, and the second
As shown in the figure, the reinforcing beam V was made up of three flanges (one flange was about twice as thick as the others) and two webs. On the other hand, reinforcing beams with the same cross-sectional shape are lined up horizontally, 10 piano wires with a diameter of 0.2 willow are sandwiched between the ends of the opposing flange surfaces where the webbing is not unevenly distributed, and the flange surfaces of the brackets are made of epoxy resin. Attached with adhesive. This reinforcing beam V differs from the reinforcing beam only in that the piano wire is arranged at the end of the flange, which is not located on the side of the material to be reinforced, of the middle flange among the three. These two reinforcing beams were each simply supported by a span of 725 skin, and a concentrated load was applied to the center of the beam from the side supported by the reinforced material. Figure 6 shows the measured values of deflection and load at this time. Deflection at yield point of reinforcing beam V is 48 ribs, load 908k9
The weight of the reinforcing beam was 69 willows and 900 kg. From the graph, the amount of work to the deflection low rib is approximately 35k9 for the reinforcement beam V, and approximately 4.4k for the skin and reinforcement beam.
9. It was skin.

[Brief explanation of drawings]

Figure 1 is a sectional view A showing the installation state of the reinforcing beam before improvement.
, a side view B and a plan view C, and FIG. 2 is a schematic cross-sectional view thereof. 3 and 4 show cross-sections of the improved reinforcing beam of the present invention. Figure 5 shows the strength characteristics of the reinforced beam. It is a graph showing one load relationship, and the sixth
The figure is a graph showing actually measured values of the strength characteristics of one example of the reinforcing beam of the present invention. 1... Reinforcement beam, 2...
Reinforced material, 3, 8, 1 1..., Flange, 4, 9, 1
2... Web, 10, 13... Flange end with increased strength. Multi-figure hair Z figure Kaya 3 figure Hair 4 figure Hair Yushikin 6 figure

Claims (1)

[Scope of Claims] 1. A reinforcing beam made of fiber-reinforced synthetic resin that is composed of two or more parallel flanges and a web connecting them, and has an H-shaped cross section or a parallel H-shaped cross section; The web is unevenly distributed to one side from the midpoint of the height of the flange and is not present at the flange end, and the flange end on the side where the web is unevenly distributed is located on the side of the reinforced material, and the web is located on the side of the reinforced material. A reinforcing beam made of fiber-reinforced synthetic resin, characterized in that the strength of the flange end or its vicinity on the side not located on the side is higher than that of other parts. 2. The reinforcing beam according to claim 1, characterized in that a highly elongated high-tension line is arranged at or near the flange end on the side that is not located on the reinforced material side. 3. The reinforcing beam according to claim 1, characterized in that the cross-sectional area at or near the flange end on the side not located on the reinforced material side is larger than other parts. 4. The reinforcing beam according to claim 1, characterized in that the reinforcing fiber density at or near the flange end on the side not located on the reinforced material side is higher than in other parts.