JPS6253754B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a reinforcing beam made of fiber-reinforced synthetic resin, and particularly to a reinforcing beam having a specific cross-sectional shape that reinforces a material to be reinforced with a specific positional relationship. Beams with an H-shaped cross section are widely used for structural materials and other purposes. For example, iron beams called H-beams are used as building structural materials and are extremely common. The present inventors have investigated various means for replacing conventional iron equipment with lightweight materials such as synthetic resins, with the aim of reducing the weight of transportation equipment such as automobiles. We researched the application of fiber-reinforced synthetic resin, which has particularly excellent strength as a synthetic resin, and examined various ways to use fiber-reinforced synthetic resin equipment in fields where H-beam steel has traditionally been used, or in fields where it can be newly applied. . Fiber-reinforced thermosetting resins such as glass fiber-reinforced unsaturated polyester resins are commonly used as fiber-reinforced synthetic resins, and H-shaped cross sections made of fiber-reinforced thermosetting resins in which fibers are arranged in the length direction by pultrusion molding etc. beams are also known. For example, a desired molded article can be obtained by impregnating a glass fiber roving with an unsaturated polyester resin and curing the resin while drawing it through a die having an H-shaped cross section. When we investigated the use of a fiber-reinforced synthetic resin beam with an H-shaped cross section in which these reinforcing fibers are arranged in the length direction to reinforce the reinforced material, we found that this beam is different from conventional H-shaped steel beams. It was noticed that the mechanical behavior of the One of the reasons for this is the directionality of the mechanical strength, that is, the tensile strength in the direction in which the reinforcing fibers are arranged is high, but the tensile strength in the direction perpendicular to it is low.
The second is that it has low rigidity and is easily deformed, and the third
is that the hardness is low. These are the original properties of fiber-reinforced synthetic resins. These properties lead to various disadvantages when using this beam as a reinforcement. FIGS. 1A, B, and C are cross-sectional views showing a state in which a flat plate 1 such as an iron plate is reinforced with a reinforcing beam 2 made of fiber-reinforced synthetic resin by a conventional method. First, the first
In FIG. A, the reinforcing beam 2 consists of two flanges 3 and 4 and one web 5, and a flat plate 1, which is a reinforced material, is located on the lower surface of the flange 3. The reinforcing beam 2 is connected to the flat plate at both ends to prevent deformation when stress is applied to the flat plate. However, in this conventional method, the reinforcing beam 2 made of fiber-reinforced synthetic resin is easily deformed. Therefore, the present inventor conducted various research studies to solve this problem, and found that a solution could be achieved by bringing the tips of the two flanges of the H-shaped beam into contact with the material to be reinforced, contrary to conventional wisdom. Obtained. Conventionally, in the use of H-shaped beams, the outer surface of one flange always abuts the material to be reinforced, and the web portion is oriented parallel to the compressive or tensile stress. For example, as seen in the rails of railroad tracks, the part that supports stress is the web part. If this is made of fiber-reinforced synthetic resin, as shown in Figure 1B, the reinforcing beam 2 with an H-shaped cross section is placed horizontally, and the tips of the two flanges are brought into contact with the material 1 to be reinforced. Strength is improved. However, with this method, if the tips of the two flanges are deformed in the opening or closing direction, cracks tend to occur in the length direction at the joint between the flange and the web part, so this method alone is not effective enough. I can't. Therefore, as shown in FIG. 1C, we considered a method in which the web portions are arranged at the tips of the two flanges, and the web portions have a U-shaped cross section and come into contact with the material to be reinforced. However, in this method, deformation of the reinforced material directly causes deformation of the web portion, and there is a risk that cracks may occur in the web portion in the length direction. In particular, both ends of the web part that are connected to the flange part are easy to buckle due to their low hardness, and therefore, the reinforcing material contacts the web part and stress is easily applied to the web part, making it easy for the web part to break. . Therefore, the inventor investigated the position of the web part and found that the problem could be solved by locating the web part on the side of the reinforced material from the midpoint of the flange in the height direction and not at the tip of the flange. I found out. This reinforcing beam has a structure as shown in the cross-sectional view of Fig. 2A, and consists of two flanges 6, 7 and one web 8, with the web part on one side from the midpoint in the height direction of the flange part. The reinforcing beams 9 are unevenly distributed in the reinforcing beams 9 and are brought into contact with or close to the reinforced material 10 as shown in the figure to reinforce the reinforced material 10. The position is on the side of the reinforcing beam 9 where the web 8 is unevenly distributed, that is, on the side where the surface of the web 8 is substantially parallel to and close to the surface of the material to be reinforced 10. Conversely, as shown in Fig. 2B, the surface of the web 8 is
The reinforcing effect decreases on the side that is far from the 0 plane. The present inventor has filed a patent application for a method of reinforcing a reinforced material by bringing a reinforcing beam with such a specific cross-sectional shape into contact with or in close proximity to the reinforced material at a specific position (patent application 53-122738, Special Publication No. 60-27879). However, when using this method, a new problem arose. That is, when reinforcing a material to be reinforced such as a metal plate having a relatively large area, it becomes necessary to use a plurality of reinforcing beams, the cross section of which is shown in FIG. 2A, in parallel. However, handling such as attaching a plurality of reinforcing beams is relatively complicated, and depending on the method of attachment, there is a risk that the reinforcing beams may become misaligned.
We also considered using reinforcing beams connected to each other on the sides of the flange with adhesives, rivets, etc., but this did not solve the problem of complexity. Therefore, Figure 3A
We considered using an integrated reinforcing beam with a cross-sectional shape similar to the one shown in Figure 2, in which multiple reinforcing beams were glued together on the side surfaces of the flanges. This reinforcing beam can be formed in exactly the same manner as the reinforcing beam shown in FIG. 2A by pultrusion molding using a mold having the cross-sectional shape.
Moreover, the reinforcing effect on the reinforced material is the second
It was found that the installation time was the same as or more than when the reinforcing beams were arranged in parallel as shown in Figure A, and the effort required for installation was not much different from the case of installing a single reinforcing beam. The present invention relates to this new reinforcing beam, that is, "a reinforcing beam that is reinforced by fixing at least its ends to a reinforced material, in which the reinforcing beam has three or more flanges and the space between them. A reinforcing beam made of fiber-reinforced synthetic resin consisting of a web to be joined, the cross section of which makes the position of the web unevenly distributed to one side from the midpoint of the height of the flange, and the end of the flange. This is a reinforcing beam having a shape in which H-shapes without the web are arranged in parallel, and the flange end on the side where the web is unevenly distributed is located on the side of the reinforced material. Examples of cross-sectional shapes of reinforcing beams of the present invention are shown in FIGS. 3A and 3B. FIG. 3A shows a cross-sectional reinforcing beam composed of three flanges 11 and two webs 12. The webs 12 are located below the midpoint of the height of the flanges 11, and the lower end is not located at the flange end. The reinforced material 13 is located at the end of the flange on the side where the web 12 is unevenly distributed. FIG. 3B is composed of five flanges 11 and four webs 12. These cross-sections have a shape in which the side pieces of an H-shape are stacked and arranged in parallel.
FIG. 4A is a side view showing a state in which both ends of the reinforcing beam 14 of the present invention are attached to a reinforced material 17, for example, a steel plate, using attachments 15 and 16, and FIG. 4B is a sectional view taken along the line -'. . This iron plate can be used for example on car doors, bonnets, trunk covers, etc.
The top surface in FIG. 4 is the front surface. A reinforcing beam is brought into contact with this back surface, and both ends of the reinforcing beam are attached to the material to be reinforced. When stress is applied to the steel plate from the outside, this stress becomes tensile stress in the length direction of the reinforcing beam and is applied to the reinforcing beam.
This tensile stress is mainly applied to the three flanges, and a portion of it also becomes the tensile stress of the web portion.
Since reinforcing fibers are arranged in the length direction of the reinforcing beam made of fiber-reinforced synthetic resin, it is particularly strong against tensile stress in this direction and can absorb stress from the outside. Assuming that the position of the web is as schematically shown in Figure 5, the height of the flange is a, the length of the web is b, and the length c is the length from the tip of the flange on the side that comes into contact with the reinforced material to the web. The relationship 1/2a>c>0 is required, preferably 3/8a≧c≧1/8a, and particularly c=1/5a to 1/7a is suitable. Also a and b
Although the relationship is not particularly limited, it is preferably about 2a>b>1/2, and particularly suitable is 1.5a≧b≧a. The reinforcing beam is made of fiber-reinforced synthetic resin. As the reinforcing fibers, glass fibers, carbon fibers, metal fibers, other inorganic fibers, high-tensile synthetic fibers, synthetic fibers, cellulose fibers, and other organic fibers can be used.
Glass fibers are particularly preferred, and fibers in rovings, roving cloths, cloths, mats, chopped strands, and other forms can be used alone or in combination. The fibers arranged in the longitudinal direction may of course include fibers arranged in directions other than the longitudinal direction. As the longitudinal fibers, not only rovings continuous in the longitudinal direction, but also chopped strands arranged in the longitudinal direction can be used. most preferably reinforcing fibers comprising longitudinally arranged rovings;
Roving alone or a combination of roving and mat, cloth, or other forms of fiber. As synthetic resins, unsaturated polyester resins,
Vinyl ester resins, epoxy resins or other thermosetting resins are suitable. In some cases, thermoplastic resins can be used, but arranging the fibers longitudinally is not as easy as with thermosetting resins. Other known materials are used to form the reinforcing beam. The most common molding method is pultrusion, but other molding methods such as press molding, hand lay-up, and other molding methods can also be used. The material to be reinforced in the present invention is generally a metal plate such as an iron plate, but it can be applied to various materials such as a synthetic resin plate, a slate plate, and a wooden plate. In addition, this form can be applied not only to flat plates but also to plate-like bodies formed in various shapes such as automobile exterior members. The reinforcing beam is usually attached to the back side of these plate-like bodies with both ends fixed. In this case, not only one reinforcing beam but also two or more reinforcing beams can be used in combination, and these beams may or may not be parallel to each other. The reinforcing beam reinforces the plate-shaped body against stress applied to the plate-shaped body, for example, external force caused by collision in the case of automobile parts, and prevents deformation or destruction of the plate-shaped body. Furthermore, since it is lighter than conventional reinforcing beams, it is suitable for the purpose of reducing the weight of automobiles. A bending test was conducted on reinforced beams made of glass fiber-reinforced unsaturated polyester resin (glass fiber content: 60% by weight) having the cross-sectional shapes shown in Figure 1A, Figures 2A and B, and Figure 3A. Ta. Fulcrum distance
A bending test was performed using a concentrated load at the center on a 75 cm free support platform, and the amount of work (Kg cm) from the load to deflection plot to a deflection of 10 cm was measured. The results are shown in the table below.

[Table] A bending test was conducted on a reinforced beam made of glass fiber-reinforced unsaturated polyester resin (glass fiber content: 60% by weight) having the cross-sectional shape shown in FIGS. 2A and B. A bending test with a concentrated load at the center was performed on a free support stand with a fulcrum distance of 75 cm, and the load at failure (Kg), deflection (cm), and workload (Kg cm) were measured. The results are shown in the table below.

【table】 [Brief explanation of the drawing]

Figures 1A, B, and C show the cross-sectional shapes of conventional reinforcing beams, and Figure 2A shows the cross-sectional shapes of the reinforcing beams previously invented by the present inventors.
shows an undesirable reinforcement method using this method. FIGS. 3A and 3B show two examples of further improved reinforcing beams of the present invention in cross-section. FIG. 4A is a side view showing a reinforcing method using the reinforcing beam of the present invention, and FIG. 4B is a sectional view along the line -'. FIG. 5 is a schematic cross-sectional view of the reinforcing beam of the present invention. 3, 4, 6, 7: Flange of conventional reinforcement beam, 5, 8: Web of conventional reinforcement beam, 11:
Flange of reinforcing beam of the present invention, 12: Web of reinforcing beam of the present invention, 1, 10, 13, 17: Reinforced material.

Claims (1)

[Claims] 1. A reinforcing beam that is reinforced by fixing at least its end portion to a reinforced material, the reinforcing beam being composed of three or more flanges and a web connecting them. A reinforcing beam made of fiber-reinforced synthetic resin whose cross section makes the position of the web unevenly distributed to one side from the midpoint of the height of the flange, and the web is not present at the end of the flange. A reinforcing beam having a shape in which H-shapes are arranged in parallel, and the flange end portion of the unevenly distributed side of the web is located on the side of the reinforced material. 2. The reinforcing beam according to claim 1, wherein the fiber-reinforced synthetic resin is a glass fiber-reinforced thermosetting resin. 3 If the height of the flange is a, and the distance between the tip of the flange on the reinforced material side and the web is c, then 3/8a≧c≧
Claim 1 characterized in that it is 1/8a
reinforcement beam. 4. The reinforcing beam according to claim 1, wherein the reinforced material is a metal plate.