JP2010023706A - Vehicle body structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle body structure having improved protection effect for an occupant when impact energy is applied to a vehicle body. <P>SOLUTION: The vehicle body structure 100 includes a vehicle body skeleton part 2 and a cabin part 8 formed independently from the vehicle body skeleton part 2. The vehicle body skeleton part 2 is formed by a fiber reinforcing composite material and includes an elliptical shape having a minor axis in the vehicle width direction. In the inside of the vehicle body skeleton part 2, reinforcing members 4a-4d and support members 10a, 10b are jointed with a predetermined tension. The cabin part 8 is supported on the vehicle body skeleton part 2 by the support members 10a, 10b. When the impact energy is applied to the vehicle body, the impact is dispersed to whole of the elliptical shaped vehicle body skeleton part and the whole of the elliptical shaped vehicle body skeleton part is deformed. The impact energy is absorbed by the whole part of the elliptical shaped vehicle body skeleton part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle body structure.

  Various vehicle body structures have been developed that enhance the occupant's protective effect when impact energy is applied to the vehicle body.

  Patent Document 1 discloses a vehicle body structure that alleviates impact energy transmitted to an occupant when impact energy is applied to the vehicle body. In this technology, the passenger compartment is formed independently of the vehicle body skeleton that forms the lower part of the vehicle body, and the vehicle compartment is made movable relative to the vehicle body skeleton, thereby impacting the vehicle body. Mitigates impact energy transmitted to passengers when energy is applied.

JP 2004-338421 A

  However, since the vehicle body structure described in Patent Document 1 is a system that absorbs impact energy by locally deforming a vehicle body skeleton portion to which the impact energy is applied when impact energy is applied to the vehicle body. In addition, when the impact energy is excessive, the vehicle body skeleton is greatly deformed locally.

An object of the present invention is to provide a vehicle body structure that prevents the vehicle body from being greatly deformed locally when impact energy is applied to the vehicle body and further enhances the occupant protection effect.
The present invention absorbs impact energy by deforming not only the vehicle body skeleton in the vicinity where the impact energy is applied, but also the entire vehicle body skeleton. The entire body skeleton is deformed so that the phenomenon that the body is largely deformed locally does not occur. A vehicle body structure that safely absorbs impact energy is provided.

The present invention relates to a vehicle body structure including a vehicle body skeleton portion that forms a lower portion of a vehicle body, and a vehicle compartment portion that is formed independently of the vehicle body skeleton portion.
In the vehicle body structure of the present invention, the vehicle body skeleton is formed of a fiber-reinforced composite material and has an elliptical shape with the vehicle width direction as the short axis.

  A fiber reinforced composite material (hereinafter referred to as FRP (Fiber Reinforced Plastics)) is a material formed by impregnating and hardening a reinforced fiber such as glass fiber with a fluid resin. When the vehicle body skeleton is formed of an elliptical FRP, the vehicle body skeleton can have spring characteristics. That is, when the vehicle body skeleton part is formed of an elliptical FRP, when impact energy is applied to the vehicle body skeleton part, the impact energy is consumed to deform the entire elliptical FRP. When the entire elliptical FRP is deformed, the entire elliptical FRP absorbs impact energy. It is possible to absorb the impact energy more safely than the conventional technique in which a part of the vehicle body is locally deformed to absorb the impact energy.

For example, when impact energy is applied from the front surface of the vehicle body, the impact energy is absorbed by deformation not only on the front surface side of the elliptical vehicle body skeleton portion but also on both side surfaces and the rear surface portion of the vehicle body skeleton portion. That is, due to the spring characteristics of the elliptical FRP, the entire elliptical FRP is deformed so as to spread in the vehicle width direction and absorbs impact energy.
When impact energy is applied from the side of the car body, it deforms not only on the side of the oval car body skeleton but also on the front and rear sides of the car body skeleton and the side that is not receiving impact energy. Absorbs impact energy. That is, due to the spring characteristics of the elliptical FRP, the entire elliptical FRP is deformed so as to spread in the vehicle length direction and absorbs impact energy.
In response to an impact from any direction, the entire elliptical FRP is deformed to absorb the impact energy. The maximum amount of deformation of the vehicle body constituent member can be reduced as compared with the case where the vicinity of the impact location is locally deformed to absorb impact energy.
In addition, since the vehicle compartment is formed independently of the vehicle body skeleton, the vehicle compartment is not easily affected even if the vehicle skeleton is deformed by an impact. According to the vehicle body structure of the present invention, the impact energy applied to the vehicle body can be dispersed and absorbed throughout the elliptical FRP. A passenger's protective effect when impact energy is applied to the vehicle body can be further enhanced.

It is preferable that the vehicle body skeleton is formed of FRP in which an elliptical fiber bundle extending in the circumferential direction is solidified with resin.
In this case, the impact energy applied to the vehicle body can be dispersed and absorbed throughout the elliptical FRP. Further, impact energy can be absorbed by applying a shearing force between the fibers extending in parallel and generating cracks running in the circumferential direction. Impact energy can be absorbed very safely.

It is preferable to further include a reinforcing member formed of reinforcing fibers. In this case, both ends of the reinforcing member are joined to the oval body frame with a predetermined tension.
The predetermined tension here refers to a tension that does not cause the reinforcing member to bend. The reinforcing member may be joined in the vehicle width direction, may be joined in the vehicle length direction, or may be joined in both directions. A plurality of reinforcing members may be formed. The reinforcing member may be one in which a bundle of reinforcing fibers is knitted in a rope shape, or may be one in which a bundle of reinforcing fibers is hardened with a resin.

When the reinforcing member is joined in the vehicle width direction, a strong tension acts on the reinforcing member when the vehicle body skeleton is deformed so as to expand in the vehicle width direction. At this time, a part of the reinforcing member is broken to absorb the impact energy.
When the reinforcing member is joined in the vehicle length direction, strong tension acts on the reinforcing member when the vehicle body skeleton is deformed so as to spread in the vehicle length direction. At this time, a part of the reinforcing member is broken to absorb the impact energy.
Energy absorption characteristics can be adjusted by adding a reinforcing member.

It is also preferable to further include a support member formed of reinforcing fibers. In this case, both ends of the support member are joined to the elliptical vehicle body skeleton, and the vehicle compartment is supported on the vehicle skeleton by the tension of the support member.
The tension | tensile_strength of a support member should just be a tension | tensile_strength of the grade which a support member does not produce. A plurality of support members may be formed. The support member may be a bundle of reinforcing fibers knitted in a rope shape, or a bundle of reinforcing fibers hardened with a resin.

  When the vehicle body suddenly stops, an inertial force acts on the vehicle compartment, so that the vehicle compartment continues to move even after the vehicle body skeleton stops. According to the above vehicle body structure, both ends of the support member are attracted with a strong tension when the vehicle body skeleton is deformed so as to expand in the vehicle width direction by impact energy. As a result, the vehicle compartment is not separated from the vehicle body skeleton by impact.

  According to the present invention, when impact energy is applied to the vehicle body, the vehicle body skeleton can absorb the impact energy as a whole and provide a vehicle body structure with a very high occupant protection effect.

Preferred features of the embodiments described below are listed.
(First Feature) The width between the upper and lower sides of the vehicle body frame portion on both side surfaces of the vehicle body is smaller than the width between the upper and lower sides of the vehicle body frame portion on the front surface and the rear surface of the vehicle body.
(Second feature) Reinforcing fibers extending in the circumferential direction of the body skeleton are continuously oriented to form the body skeleton.
(3rd characteristic) Aramid fiber is used as a material of a reinforcement member and a supporting member.
(Fourth feature) Polycarbonate is used as a material for the passenger compartment.

(First embodiment)
FIG. 1 shows a schematic perspective view of a vehicle body structure 100 according to a first embodiment of the present invention.
The vehicle body structure 100 includes a vehicle body skeleton portion 2 that constitutes a lower portion of the vehicle body. The vehicle body skeleton 2 is made of FRP. The vehicle body skeleton 2 is formed in an elliptical shape with the vehicle width direction as the short axis. Reinforcing members 4 a to 4 d are joined to the vehicle body skeleton portion 2. One reinforcing member 4a is joined in the vehicle length direction. Three reinforcing members 4b to 4d are joined in the vehicle width direction. Support members 10 a and 10 b are joined to the vehicle body skeleton part 2. The support member 10 a passes through the upper rear part of the vehicle compartment 8. Both ends of the support member 10 a are joined to the vehicle body skeleton part 2. Both ends of the support member 10 a are joined to the vehicle body skeleton part 2. The support member 10 b passes through the front of the passenger compartment 8. Both ends of the support member 10 b are joined to the vehicle body skeleton part 2. The vehicle compartment portion 8 is supported by the vehicle body skeleton portion 2 by the tension of the support members 10a and 10b. 6 a to 6 d shown in the figure show wheels mounted on the vehicle body skeleton part 2. The vehicle body structure 100 includes a vehicle compartment portion 8 that is formed independently of the vehicle body skeleton portion 2. For the sake of clarity, the wheels 6a to 6d and the passenger compartment 8 are shown transparently. The vehicle compartment 8 has a space where passengers can get on and off. The bottom surface of the passenger compartment 8 is supported by the reinforcing members 4a to 4d. In this embodiment, the shape of the passenger compartment 8 is an egg shape, but may be a box shape or the like.

  The vehicle body skeleton part 2 can be manufactured by, for example, a filament winding method. Specifically, a long carbon fiber or a long glass fiber is wound around an elliptical mold. Next, after the impregnated reinforcing fiber is impregnated with a thermosetting resin having fluidity, it is thermoset. An epoxy resin or the like can be used as the thermosetting resin. Next, the oval body skeleton 2 can be formed by extracting the reinforcing fiber cured with the resin from the oval mold.

Carbon fiber, aramid fiber, etc. can be used for the material of the reinforcing members 4a to 4d and the supporting members 10a and 10b. It may be twisted in a rope shape, or may be improved in strength by curing with a thermosetting resin or the like.
Iron, aluminum, or the like can be used as the material of the compartment 8, but a material such as CFRP (Carbon Fiber Reinforced Plastics) is preferably used to reduce the weight of the vehicle body.

  According to the vehicle body structure 100, when impact energy is applied from the front surface of the vehicle body, the impact energy propagates from the front surface of the vehicle body skeleton portion 2 to the entire vehicle body skeleton portion 2, and spreads in the vehicle width direction. 2 is deformed. At this time, a part of the reinforcing members 4b to 4d is broken, so that the impact energy is absorbed and the impact energy applied to the passenger compartment 8 is alleviated. Even when impact energy is applied to the side surface of the vehicle body, the impact energy is propagated to the entire vehicle body skeleton portion 2, and the vehicle body skeleton portion 2 is deformed so as to spread in the vehicle length direction. At this time, when a part of the reinforcing member 4a is broken, the impact energy is absorbed, and the impact energy applied to the passenger compartment 8 is alleviated. The vehicle body structure 100 can travel stably during normal traveling because the spring characteristics of the vehicle body skeleton 2 do not work. Furthermore, in the vehicle body structure 100, by using FRP as the material of the vehicle body skeleton part 2, the vehicle body can be reduced in weight, and the impact energy corresponding to the light weight can be reduced.

FIG. 2 shows a schematic top view of the vehicle body structure 100. When impact energy is applied to the front surface of the vehicle body, the impact energy is applied to the vehicle body skeleton portion 2 in the direction of A in the figure. The impact energy applied to the vehicle body skeleton part 2 propagates throughout the vehicle body skeleton part 2, and the vehicle body skeleton part 2 is deformed in a direction (B direction in the drawing) extending in the vehicle width direction. There is no local deformation of the vehicle body skeleton portion 2 to which the impact energy is applied.
When impact energy is applied to the side of the vehicle body, the impact energy applied to the vehicle body skeleton portion 2 is propagated throughout the vehicle body skeleton portion 2, and the vehicle body skeleton portion 2 is deformed in a direction spreading in the vehicle length direction. There is no local deformation of the vehicle body skeleton portion 2 to which the impact energy is applied.

  FIG. 3 shows a schematic side view of the vehicle body structure 100. When impact energy in the direction of A in the figure is applied to the traveling vehicle body skeleton part 2 and the vehicle body stops, the vehicle compartment part 8 tries to move in the direction of C direction in the figure by inertial force even after stopping. On the other hand, when the vehicle body skeleton part 2 is deformed so as to spread in the vehicle width direction by impact energy, both ends of the support members 10a and 10b are attracted with a strong tension. At this time, the support member 10b supports the front of the compartment portion 8 with a stronger force than when traveling, so that the force that the compartment portion 8 tries to move in the direction C is suppressed. Further, even when force is applied in the direction in which the vehicle compartment 8 moves upward due to impact energy, the support member 10a supporting the upper portion of the vehicle compartment 8 is attracted with a strong tension, so that the vehicle compartment 8 The force to move upward is suppressed. For this reason, the vehicle compartment portion 8 is not separated from the vehicle body skeleton portion 2 by impact energy.

  Further, as shown in FIG. 3, the width W2 between the upper and lower sides of the vehicle body skeleton part 2 on both side surfaces of the vehicle body is formed to be smaller than the widths W1 and W3 between the upper and lower sides of the vehicle body skeleton part 2 on the front and rear surfaces of the vehicle body. It is preferable. If the width between the upper and lower sides of the vehicle body skeleton part 2 on both side surfaces of the vehicle body is formed with a small width, the passenger can easily get on and off the vehicle compartment part 8.

  FIG. 4 shows a simplified diagram of the vehicle body skeleton part 2. The vehicle body skeleton part 2 may generate cracks 12 when it receives excessive impact energy. The impact energy is absorbed by the occurrence of the crack 12. Since FRP is not a uniform material such as metal, it causes brittle fracture. The impact applied to the vehicle body skeleton part 2 becomes maximum at the neutral axis in the thickness direction. Therefore, as shown in FIG. 4, the crack 12 is generated along the neutral axis of the thickness W <b> 4 of the vehicle body skeleton portion 2, and the crack 12 advances along the circumferential direction D of the vehicle body skeleton portion 2. The crack 12 is generated by a shearing force generated between fibers extending in the circumferential direction D. Even when excessive impact energy is received, the impact energy is absorbed by the crack 12 generated along the circumferential direction D of the vehicle body skeleton portion 2, so that the vehicle compartment portion 8 is not easily affected by the impact energy.

  In the vehicle body structure according to the present invention, it is preferable that the reinforcing fiber extending in the circumferential direction of the vehicle body skeleton part is continuously oriented to form the vehicle body skeleton part. Impact energy can be absorbed by generating cracks extending along the circumferential direction. The passenger compartment is less susceptible to impact energy.

  In the vehicle body structure of the present invention, it is preferable to use an aramid fiber as a material for the reinforcing member and the supporting member. By using an aramid fiber, the strength of the reinforcing member and the supporting member can be improved.

  In the vehicle body structure of the present invention, it is preferable to use polycarbonate as the material for the compartment. The vehicle compartment can be reduced in weight, and the impact energy corresponding to the lightweight can be reduced.

As mentioned above, although the Example of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

1 is a schematic perspective view of a vehicle body structure 100 according to a first embodiment of the present invention. A schematic top view of the vehicle body structure 100 is shown. A schematic side view of the vehicle body structure 100 is shown. A simplified view of the vehicle body skeleton part 2 is shown.

Explanation of symbols

2: Vehicle body frame portions 4a to 4d: Reinforcing members 6a to 6d: Wheels 8: Vehicle compartment portions 10a, 10b: Support members 12: Cracks W1 to W3: Vehicle body frame portion width W4: Vehicle body frame portion thickness A: Front surface of vehicle body Direction B: Impact direction from which the vehicle body skeleton part is deformed by impact energy from the front surface of the vehicle body C: Direction in which the vehicle compartment portion moves due to impact energy from the front surface of the vehicle body D: Circumferential direction of the vehicle body skeleton portion

Claims (4)

A vehicle body structure comprising a vehicle body skeleton part that forms the lower part of the vehicle body, and a vehicle compartment part formed independently of the vehicle body skeleton part,
The vehicle body structure is characterized in that the vehicle body skeleton is formed of a fiber reinforced composite material and has an elliptical shape with the vehicle width direction as a short axis.   2. The vehicle body structure according to claim 1, wherein the vehicle body skeleton is formed of a fiber reinforced composite material in which a fiber bundle extending in the circumferential direction of the elliptical shape is solidified with a resin. It further comprises a reinforcing member formed of reinforcing fibers,
3. The vehicle body structure according to claim 1, wherein both ends of the reinforcing member are joined to the elliptical vehicle body skeleton portion with a predetermined tension. Further comprising a support member formed of reinforcing fibers;
Both ends of the support member are joined to the oval body skeleton,
The vehicle body structure according to any one of claims 1 to 3, wherein the vehicle compartment portion is supported by the vehicle body skeleton portion by a tension of the support member.

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