JPH03220042A - Shock absorber equipped with frp member - Google Patents

Abstract

PURPOSE:To bend a FRP member in the specified direction alone so as to secure specified shock absorbing capacity by forming a recess at the end of the FRP member formed in curvature, and also arranging an action stopping member, which engages with the recess, in the base material to which this end is fixed. CONSTITUTION:A shock absorber, for example, a bumper system 10 for automobile is provided with right and left twin FRP members 11 doubling as bumper attaching stays. Moreover, one end 12 of the FRP member 11 is fixed to the side member 14 on the side of a car body through a base material 13. At this time, a longitudinal groove-shaped recess 30 is formed, over the whole length, at the side of the curve of the FRP member 11. On the other hand, at the base material 3, a belt-shaped action stopping member 35 made of metal, which engages with the recess 30, is arranged. And in the condition that the recess 30 and the action stopping member 35 are engaged with each other, the end of the FRP member 11 is fixed to the base material 13. Hereby, it suppresses the FRP member 11 from bending excepting the designated direction during absorption of shock, whereby specified shock absorbing capacity is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shock absorbing device including an FRP member, which is applied to, for example, a bumper system for a vehicle.

[Conventional technology] In a bumper system used in vehicles such as automobiles,
The use of FRP members is being considered to improve shock absorption performance. For example, in the prior art shown in FIGS. 13 and 14, an FRP member 3 shaped into a U or J shape is provided between a vehicle body side member 1 and a bumper body 2. One end 3a of the FRP member 3 is fixed to the vehicle body member 1 by a fastening member 4 such as a bolt, and the other end 3b is connected to the bumper body 2 via a suitable connecting member 5. When an external force in the direction of arrow F (the longitudinal direction of the vehicle body) is applied to the load point P of the bumper body 2 due to a collision, etc., F
The impact is alleviated by bending the FRP member 3 in a direction in which the radius of curvature of the RP member 3 narrows.

[Problem to be solved by the invention] When various tests were conducted to evaluate the performance of the above Bamba system, it was found that the FRP member 3 was unable to exhibit the load-deflection characteristics and predetermined energy absorption performance as designed. there were. In other words, the arrow F on the FRP member 3
When a large load is applied in a direction, stress in a direction other than the predetermined direction is generated in the FRP member 3, and the FRP member 3 may be twisted and destroyed under a design load.

When we investigated the cause of the above problem, we found that the end 3a of the FRP member 3 was damaged in the vertical direction (width direction of the FRP member 3) during shock absorption.
It turns out that moving to the world is a big factor. In particular, in the FRP member 3 of the above-mentioned prior art, since the distance g1 from the fastening component 4 to the load point P is relatively long, when the load is applied to the load point P, the end portion 3a of the FRP member 3 moves in the vertical direction. Easy to move.

Therefore, an object of the present invention is to suppress the application of force in a direction other than the predetermined direction, such as twisting of the FRP member.
It is an object of the present invention to provide a shock absorbing device equipped with an FRP member in which the breaking load of the P member can be maintained at a predetermined value.

[Means for Solving the Problems] The present invention, which was developed to achieve the above object, is an FRP member that is formed into a substantially U-shaped or J-shaped curved shape and is loaded with a load in a direction in which the radius of curvature narrows. And this FRP
A shock absorbing device comprising a base material to which an end of a member is fixed, wherein a recess is provided at the end of the FRP member and a locking member that fits into the recess is provided on the base material. It is.

[Operation] When an external force is applied to the FRP member due to a collision, etc., the FRP
The member deforms in a direction in which the radius of curvature narrows.

Since the ends of the FRP member are restrained so as not to move in the width direction by the above-mentioned locking member, this FRP member mainly acts under a predetermined bending stress, and is subject to twisting and other stress that may cause damage to the FRP member. Generation of excessive stress is suppressed.

[Example 1] The first embodiment of the present invention will be described below with reference to Figures 1 to 5.
This will be explained with reference to the figures. The illustrated shock absorbing device 10 is applied to a bumper system for an automobile, and includes a pair of left and right FRP members 11 that also serve as bumper mounting stays. One end 12 of the FRP member 11 is connected to a side member 14 as an example of a member on the vehicle body side via a base material 13.
Fixed. The base material 13 is provided on the end surface of the side member 14.

On the front side of the FRP member 11, a Haller damper body 15 called an armature, a synthetic resin fascia 16 covering the bumper body 15, and the like are provided. 17 is a tire. The bumper main body 15 is, for example, a molded product made of fiber-reinforced plastic, but it may also be made by press-molding a sheet metal. The bumper body 15 connects to the other end 1 of the FRP member 11 via the connecting bracket 1-18.
It is connected to 9.

The FRP member 11 is formed into a substantially U-shaped or J-shaped curved shape when viewed from above by unidirectional reinforcing fibers 20 (only a portion is shown) along the length of the member 11 and a well-known matrix resin 21. has been done. Although a glass fiber bundle is used as the unidirectional reinforcing fiber 20, a carbon fiber bundle or an organic fiber bundle may be used depending on the case. As shown in FIG. 3, flat portions 22 and 23 having a length of L2 are provided at both ends of the FRP member 11, respectively. This FRP member 11 is used so as to be bent in a direction in which the radius of curvature R is decreased by a force in the direction of arrow F applied to a load point P during shock absorption.

As shown in FIG. 5 etc., the bracket 18 is attached to the bolt 2
5 or the like, but a convex portion 18a may be provided on the back side of the bracket 18 to fit into a recess 30, which will be described later. According to such a fitting structure, 1
Even though a real bolt 18 is used, the bracket 18 does not rotate, and the bracket 18 can be securely fixed.

A groove-shaped recess 30 along the length direction of the FRP member 11 is provided on the curved outer surface of the FRP member 11, that is, on the side where tensile stress is generated when a load in the direction of arrow F is applied to this FRP member 11. It is provided over the entire length of the member 11. Therefore, this FRP member 11 has a concave cross section as shown in FIG. It is molded into an integral shape.

A band-shaped metal stopper member 35 that fits into the recess 30 is provided on the base material 13 . The stopper member 35 is fixed to the base material 13 by suitable fixing means such as welding. This locking member 35 is fitted into the recess 30. The end portion 12 of the FRP member 11 is fixed to the base material 13 with appropriate fixing parts 36, 37 such as bolts. These fixing parts 36 and 37 are mutually attached to the FRP member 1.
1 are spaced apart in the length direction.

Therefore, the distance 112 from the load point P to the fixing component 37 is shorter than the distance g of the conventional product (see FIG. 14), and the end 12 of the FRP member 11 becomes more difficult to move in the vertical direction.

The dimensions of the FRP member 11 are, for example, the total width B-65m
In, thickness of thin part 31 t+-6non, thickness of thick part 32 t2-18a+I11, width B of thin part 31, -30
mm, and the radius of curvature is R-59 mm. Further, the length of one flat portion 22 is -25n+m, and the length of the other flat portion 23 is L2-4711II11.

In the shock absorbing device 10 configured in this way, when a load F in the front-rear direction is applied to the bumper body 15 due to a collision or the like, the FRP member 11 is bent in the direction in which the radius of curvature R is narrowed, and is aligned in one direction. reinforcing fiber 20
This and the matrix resin 21 that hardens the fibers 20 work together to store collision energy. The end portion 12 of the FRP member 11 of this embodiment is restrained from moving in the width direction (vertical direction in the figure) by fitting the recess 30 and the stopper member 35, so that the load F is F when I joined
The RP member 11 is suppressed from being bent in a twisting direction, and a shock absorbing function is exhibited under a predetermined stress.

Table 1 below shows the FRP member 11 of this embodiment and the conventional product (No. 14
(see figure). FRP of this example
The member 11 has a spring constant of approximately 1 when the spring constant is the same as that of the conventional product.
5% weight reduction can be achieved.

Table 1 FIG. 6 shows a second embodiment of the present invention. The length L4 of the stopper member 38 in this embodiment is the same as the length L4 of the stopper member 38 in the first embodiment.
It is about half of 5. The other configurations and effects are the same as those of the first embodiment.

The third embodiment of the present invention shown in FIG.
A wide portion 40 is provided extending over the end portion 12 of 1, and a recess 41 is provided only on the inside of this wide portion 40, and the locking member 38 is fitted into this recess 41. Further, two bolts 25 and 26 are used to prevent the bracket 18 from rotating.

In the fourth embodiment of the present invention shown in FIG. 8, an end plate 45 that is a part of the side member 14 is integrally formed with a convex portion 46 for preventing movement. If the end plate 45 is too thick and it is difficult to form the convex portion 46, the end plate 4
A portion corresponding to the convex portion 46 is provided on a base material (not shown) made of a thin sheet metal or synthetic resin plate prepared separately from 5, and this base material is fixed to the end plate 45 by welding, bolts, etc. You can.

The fifth embodiment of the present invention shown in FIG.
A locking member 60 having a shape that holds the flat portion 23 of the end portion 12 of 1 is used, and the locking member 60 is fixed to a base material 62 with an appropriate fixing part 61 such as a bolt or rivet. It has become.

In any of the above embodiments, an adhesive may be used in combination to fix the FRP member 1.
An appropriate spacer may be interposed to prevent wear, damage, etc. of 1.

In the sixth embodiment of the present invention shown in FIG.
A locking member 70 shaped to hold the end 12 of the RP member 11 is fixed to the end 12 with adhesive, and the locking member 7o is attached to a base material using appropriate fixing parts 71 such as bolts and spacers 72, etc. I am trying to fix it at 62. Between the stopper member 70 and the FRP member 11, the FR
An appropriate spacer may be interposed for the purpose of preventing wear of the P member 11, etc.

As in the FRP member 11 shown in FIG. 11, a recess 30 may be provided on the compression side surface, or as in the FRP member 11 shown in FIG. 12, on the compression side and tension side surfaces. Recessed portions 30a, respectively.

30b may be provided to reduce the weight.

Note that the specific aspects such as the mounting direction of the FRP member 11 may be other than those of the above-mentioned embodiments, and the present invention can be used for various applications other than the bumper system.

[Effects of the Invention] According to the present invention, it is possible to suppress the FRP member from bending in a direction other than the designated direction when absorbing a shock, and it is possible to cause the FRP member to exhibit a predetermined shock absorption performance.

[Brief explanation of drawings]

1 to 5 show a first embodiment of the present invention.
The figure is a perspective view of the shock absorbing device, FIG. 2 is a plan view of the bumper system equipped with the shock absorbing device, FIG. 3 is a plan view of the FRP member, and FIG. 4 is taken along line IV-IV in FIG. 3. cross section,
FIG. 5 is a perspective view of the bracket mounting part, FIGS. 6 to 10 are perspective views showing different embodiments of the present invention, and FIGS. 11 and 12 are FR
FIG. 13 is a perspective view showing a modified example of the P member, and FIG. 13 is a plan view of a bumper system equipped with a conventional shock absorption device.
FIG. 4 is a perspective view of the conventional shock absorbing device shown in FIG. 13. 10... Shock absorption device, 11... FRP member, 1
2... End portion, 13... Base material, 14... Vehicle body side member, 20... Unidirectional reinforcing fiber, 21... Matrix resin, 30... Concave portion, 35.38... - Stopping member, 46... Stopping convex part, 50... Base material, 51
．． ．． 5260... Stopping member, 62-... Base material, 7
0... Stopping member. Figure 3 Figure 5 Figure 6

Claims (2)

[Claims] (1) An impact comprising an FRP member that is formed into a substantially U-shaped or J-shaped curved shape and to which a load is applied in a direction that narrows the radius of curvature, and a base material to which the ends of the FRP member are fixed. In the absorption device, a recess along the length of the FRP member is provided at least at the end of the FRP member, and a movement stopping member that can fit into the recess is provided in the base material, and movement with the recess is provided. A shock absorbing device equipped with an FRP member, characterized in that the end portions of the FRP member are fixed to the base material with the stop members fitted together. (2) The FRP member according to claim 1, wherein the recess extends over the entire length of the FRP member in the longitudinal direction, and the recess is provided on a side where tensile stress is generated when a load in the direction is applied to the FRP member. Shock absorption device with.