JP5210117B2 - Bumperin force for vehicles - Google Patents

Description

  The present invention relates to a bumper force used in a vehicle bumper device.

In order to suppress as much as possible the impact on the occupant when another object collides with the vehicle, bumper devices that absorb the impact energy transmitted to the vehicle body are mounted on the front and rear of the vehicle.
The bumper device includes an energy absorber made of an elastic material such as urethane foam whose main purpose is to reduce impact on other objects, a bumper force that holds the energy absorber and absorbs large impact energy by its own deformation, A crash box or a bumper stay that fixes the bumper force to a vehicle body side member (for example, a side member) is provided.

  Patent Document 1 describes a laminate-reinforced bumper force for a vehicle. The bumper force includes a hollow member in which a long space is formed by a pair of side walls that are separated from each other, and a carrier member is provided in the hollow member. The space between the hollow member and the carrier member is filled with a heat-foamable resin that forms a structural foam in its cured state. The heat-foamable resin joins the beam and the carrier to increase the strength of the bumper force itself. It has improved.

Special Table 2002-534304

In the bumper force described in Patent Document 1, for example, the hollow member is formed of a metal material, and the carrier member is formed of a plastic material or a polymer material. The thermally foamable resin is foamed by heating. At this time, the carrier member that is more easily deformed than the hollow member may be deformed so that the side wall of the carrier member falls to the inside of the carrier member when the thermally foamable resin foams and increases in volume.
The carrier member retains the shape of the thermally foamable resin (structural foam in the cured state) which is a reinforcing material layer. It is difficult to say that the carrier member in which the above-described deformation has occurred is a shape suitable for maintaining the shape and strength of the reinforcing material layer. When such a carrier member is used for the bumper force, the strength as the bumper force is poor.

  Further, if the entire space between the hollow member and the carrier member is filled with the thermally foamable resin, the weight of the bumper force increases.

  Accordingly, an object of the present invention is to provide a bumper force for a vehicle that can prevent the carrier member from being deformed when the thermally foamable resin is foamed, and can be reduced in weight without deteriorating the collision performance when colliding with another object. is there.

In order to achieve the above object, the first characteristic configuration of the bumper force for a vehicle according to the present invention is a long length formed by a pair of opposing wall portions and a pair of connection wall portions connecting the wall portions. A hollow member having at least one shaped space, a pair of opposing carrier wall portions, a carrier connecting wall portion connecting the carrier wall portions, and the pair of carrier wall portions supported in the hollow member A carrier member provided with a spacer, and arranged so that the connection wall portion and the carrier connection wall portion are on the collision side with other objects, and among the gap between the hollow member and the carrier member, comprising a resin portion a collision side of arranging the heat expandable resin in the boundary portion of the connecting wall portion and at least the wall portion of the other material, the spacers, rib-shaped and connected to the carrier connecting wall portion Formed lies in the fact that is formed thicker as the side of the carrier connecting wall portion.

  According to the first characteristic configuration described above, since the spacer supporting the pair of carrier wall portions can be incorporated in the carrier member, the carrier wall portion is the carrier even when the thermally foamable resin is foamed by heating. The spacer can prevent deformation that falls inside the member. Therefore, the carrier member can maintain a shape suitable for maintaining the shape and strength of the thermally foamable resin that is the reinforcing material layer even after foaming of the thermally foamable resin. Thereby, the vehicle bumper force of the present invention has a stable strength. Furthermore, when the shape of the carrier member is stabilized, the bonding state between the hollow member and the carrier member is stabilized, and the strength of the bumper force is further improved.

Further, in this configuration, the connection wall portion and the carrier connection wall portion are arranged so as to be on the collision side with another object, and the resin material portion is not in contact with the other object in the gap between the hollow member and the carrier member. It is the structure which has arrange | positioned the thermally foamable resin at the boundary part of a wall part and a connection wall part at the collision side. Therefore, for example, instead of filling the entire gap between the hollow member and the carrier member with the heat-foamable resin as a reinforcing material, the heat-foamable resin is applied only in the vicinity of the boundary portion where the wall portion and the connection wall portion are connected. Can be filled. At the time of collision with another object, an impact load is applied particularly to the boundary portion. For this reason, even when the thermal foamable resin is filled only in the vicinity of the boundary portion, the same collision performance as that obtained when the entire gap is filled with the thermal foamable resin can be obtained. Accordingly, in this configuration, the heat-foamable resin that fills the gap between the hollow member and the carrier member can be reduced, so that the bumper force can be reduced without reducing the collision performance when colliding with other objects. .
When the bumper device collides with another object, a collision load acts on the carrier connection wall portion via the connection wall portion in the bumper force. In this configuration, since the rib-shaped spacer is connected to the carrier connection wall portion, the strength of the carrier connection wall portion can be improved at the position where the spacer is formed. Therefore, it is possible to prevent the carrier member from being broken by collision with another object at the position.
Moreover, in this structure, since the intensity | strength of a spacer can be improved near the carrier connection wall part side, the intensity | strength of a carrier connection wall part can further be improved in the position in which the said spacer was formed.

  The second characteristic configuration of the vehicular bumper force according to the present invention is that a thinned portion where the thermally foamable resin is not disposed is formed on the resin material portion at least on the collision side with another object.

  According to this configuration, it is possible to reduce the weight by the weight of the heat-foamable resin corresponding to the volume of the cutout portion and to reduce the cost as compared with the resin material portion when the cutout portion is not formed. .

  A third characteristic configuration of the vehicular bumper force according to the present invention is that the spacer is provided at a position corresponding to a region where the thermally foamable resin is disposed in the pair of carrier walls.

In this configuration, in the region where the heat-foamable resin is disposed, there is always a spacer at a position separating the carrier wall. Thereby, when a carrier wall part receives the thermal expansion effect | action of a thermally foamable resin, the deformation | transformation that a carrier wall part falls down inside a carrier member can be prevented reliably.
If there is a region where the spacer is not present at the position where the carrier wall portion is separated in the region where the heat-foamable resin is disposed, if the carrier wall portion receives the thermal expansion action of the heat-foamable resin, the position where the spacer does not exist There is a possibility that the carrier wall may be deformed so as to fall inward.

Embodiments of the present invention will be described below with reference to the drawings.
The bumper force X of the present invention is a component member of a bumper device that absorbs impact energy transmitted to the vehicle body in order to suppress as much as possible the impact on the occupant when another object collides with the vehicle. The bumper force X is attached to the vehicle body via a crash box or the like.

As shown in FIGS. 1 to 3, the bumper force X of the present invention is a long space 14 formed by a pair of opposing wall portions 11 and a pair of connection wall portions 12 that connect the wall portions 11 to each other. A hollow member 10 provided with at least one, a pair of carrier wall portions 21 that are housed in the hollow member 10 and face each other, a carrier connection wall portion 22 that connects the carrier wall portions 21, and a pair of carrier wall portions 21. And a carrier member 20 provided with a spacer 30 for supporting.
The connection wall portion 12 and the carrier connection wall portion 22 are arranged so as to be on the collision side with another object, and at least the wall portion 11 is on the collision side with the other object in the gap between the hollow member 10 and the carrier member 20. And a resin material portion 40 in which a thermally foamable resin 41 is disposed at the boundary portion 13 of the connection wall portion 12.

(Hollow member)
In the present embodiment, the hollow member 10 includes three long spaces 14 formed by the pair of wall portions 11 and the pair of connection wall portions 12. The long space 14 has a rectangular cross section.
The connection wall portion 12 is disposed on the collision side with another object. If the bumper force X collides with another object, a collision load acts directly on the connecting wall portion 12 and the connecting wall portion 12 buckles and deforms toward the long space 14, thereby absorbing the impact of the collision. The Accordingly, the number and size of the long spaces 14 (for example, the distance between the pair of wall portions 11) and the like are determined in consideration of the parts of the vehicle body on which the bumper force X is mounted (front, side, rear). Once determined, the crash performance can be adjusted.
Thus, the hollow member 10 provided with a plurality of long spaces 14 can reduce the weight of the bumper force X.

  The hollow member 10 forming the outer surface of the bumper force X is made of, for example, a metal material. Usually, a member used for a vehicle is preferably made of aluminum in order to reduce the weight, but is not limited thereto.

(Carrier material)
The carrier member 20 is provided in the hollow member 10 and includes a pair of opposing carrier wall portions 21, a carrier connection wall portion 22, and a spacer 30.

  A long space (carrier long space 23) is formed on the inner surface of the carrier member 20 by the pair of carrier wall portions 21 and the carrier connection wall portion 22.

  The carrier member 20 is housed in a long space 14 provided in the hollow member 10 (FIG. 2) in a state where an unfoamed thermally foamable resin 41 is applied to the surface of the carrier member 20 (FIG. 3). By heating in this state, the thermally foamable resin 41 is thermally expanded. Since the thermally foamable resin 41 is surrounded by the hollow member 10 and the carrier member 20, the expansion range of the thermally foamable resin 41 is limited. For this reason, when the thermally foamable resin 41 expands to some extent, the carrier member 20 is firmly bonded to the hollow member 10.

Thus, when the hollow member 10 and the carrier member 20 are bonded together, the carrier member 20 is made of a material having heat resistance because the heat-foamable resin 41 that performs heat treatment is used. Examples of the material include metals and heat-resistant resins, but are not limited thereto.
Further, since the carrier member 20 is bonded to the hollow member 10 by the expanded thermal foamable resin 41, the strength of the bumper force X can be improved if the carrier member 20 is made of a material having a certain degree of rigidity. .

The carrier member 20 of this embodiment exemplifies a long member having a U-shaped cross section. With such a shape, the carrier wall 21 and the carrier connecting wall 22 are in a state along the wall 11 and the connecting wall 12 of the hollow member 10 in the long space 14 having a rectangular cross section. The carrier member 20 can be internally provided in the hollow member 10.
In the bumper force X of the present invention, since the connection wall portion 12 and the carrier connection wall portion 22 are arranged on the collision side with other objects, the carrier connection wall portion 22 is arranged along the connection wall portion 12. It is in a state.
Thus, if it is set as the structure which does not provide a wall part in the other side of the said collision side in the carrier member 20, the carrier member 20 can be reduced in weight.

  The carrier member 20 can be, for example, one-half to one-fifth the length of the bumper force X, but is not limited to this size.

At least one spacer 30 is provided in the carrier long space.
In the present invention, since the spacer 30 supporting the pair of carrier wall portions 21 can be incorporated in the carrier member 20, even when the thermally foamable resin 41 is foamed by heating, the carrier wall portion 21 is the carrier. The spacer 30 can prevent deformation that falls down inside the member 20. Therefore, the carrier member 20 can maintain a shape suitable for maintaining the shape and strength of the thermally foamable resin 41 that is the reinforcing material layer even after the foaming of the thermally foamable resin 41. Therefore, the bumper force X of the present invention has a stable strength. Further, when the shape of the carrier member 20 is stabilized, the bonding state of the hollow member 10 and the carrier member 20 is stabilized.

Further, in the present invention, the connection wall portion 12 and the carrier connection wall portion 22 are arranged so as to be on the collision side with another object. Since the resin material portion 40 is formed in the gap between the connection wall portion 12 and the carrier connection wall portion 22, a space for providing the resin material portion 40 can be formed on the collision side with another object by this configuration.
In the gap between the hollow member 10 and the carrier member 20, the resin material portion 40 is on the collision side with other objects, and the thermally foamable resin 41 is disposed at least at the boundary portion 13 between the wall portion 11 and the connection wall portion 12. It is a configuration. Therefore, for example, the entire gap between the hollow member 10 and the carrier member 20 is not filled with the heat-foamable resin 41 as a reinforcing material, but only in the vicinity of the boundary portion 13 where the wall portion 11 and the connecting wall portion 12 are connected. The thermally foamable resin 41 can be filled (FIG. 2). At the time of collision with another object, an impact load is particularly applied to the boundary portion 13. Therefore, even when the thermal foamable resin 41 is filled only in the vicinity of the boundary portion 13, the same collision performance as that obtained when the thermal foamable resin 41 is filled in the entire gap can be obtained (described later). See Example 1). Therefore, in the present invention, since the heat-foamable resin 41 filled in the gap between the hollow member 10 and the carrier member 20 can be reduced, the bumper force X can be reduced without reducing the collision performance when colliding with other objects. Can be reduced in weight.

The spacer 30 is provided at a position corresponding to a region where the heat-foamable resin 41 is disposed in the pair of carrier wall portions 21.
With this configuration, the spacer 30 is always present at a position separating the carrier wall 21 in the region where the thermally foamable resin 41 is disposed. Thereby, when the carrier wall 21 is subjected to the thermal expansion action of the thermally foamable resin 41, the spacer 30 can reliably prevent the carrier wall 21 from being deformed so as to fall inside the carrier member 20.
If there is a region where the spacer 30 does not exist at a position separated from the carrier wall 21 in the region where the heat-foamable resin 41 is disposed, if the carrier wall 21 is subjected to the thermal expansion action of the heat-foamable resin 41, the spacer There is a possibility that the carrier wall 21 may be deformed so as to fall inward from a position where 30 does not exist.

  The spacer 30 can be integrally formed with the carrier member 20 by injection molding. However, it is not limited to such an embodiment, and the carrier member 20 and the spacer 30 may be configured as separate members.

  The spacer 30 is connected to the carrier connection wall portion 22 and formed in a rib shape. When the bumper device collides with another object, in the bumper force X, a collision load acts on the carrier connection wall portion 22 via the connection wall portion 12. In this configuration, since the rib-shaped spacer 30 is connected to the carrier connection wall portion 22, the strength of the carrier connection wall portion 22 can be improved at the position where the spacer 30 is formed. Therefore, it is possible to prevent the carrier member 20 from being broken by collision with another object at the position.

  The spacer 30 is configured to exhibit a plate shape, for example, and is formed thicker toward the carrier connection wall portion 22 side. In this configuration, since the strength of the spacer 30 can be improved toward the carrier connection wall portion 22, the strength of the carrier connection wall portion 22 can be further improved at the position where the spacer 30 is formed.

(Resin material part)
The resin material portion 40 is formed by filling the gap between the connection wall portion 12 and the carrier connection wall portion 22 with a thermally foamable resin 41. The thermally foamable resin 41 is a resin that expands by heating and increases in volume. For example, the thermally foamable resin 41 is configured by adding a pyrolytic foaming agent to a thermoplastic resin.

  When heating is performed in a state where the gap between the hollow member 10 and the carrier member 20 is filled with the unfoamed thermally foamable resin 41, the thermally foamable resin 41 is foamed to increase the volume, and the hollow member 10 and the carrier member 20 The space between is filled with the expanded thermal foamable resin 41. Thereby, since the hollow member 10 and the carrier member 20 can be integrated by the thermally foamable resin 41, the strength of the bumper force X can be improved. The cured heat-foamable resin 41 is excellent in impact absorbability because there are many bubbles.

The resin material part 40 is formed with a lightening part 42 where the heat-foamable resin 41 is not disposed at least on the collision side with another object.
If the lightening part 42 is formed in this way, the weight of the thermally foamable resin 41 corresponding to the volume of the lightening part 42 can be reduced as compared with the resin material part 40 when the lightening part 42 is not formed. In addition, the cost can be reduced.

In the present invention, since the resin material portion 40 to which the heat-foamable resin 41 is applied has the thinned portion 42 formed, the heat-foamable resin 41 is partially in the gap between the hollow member 10 and the carrier member 20. It has been applied.
FIG. 4 shows the result of an experiment in which the collision performance of the bumper force X of the present invention and the bumper force X (comparative example) in which the thermally foamable resin 41 is applied over the entire space are examined. .
In FIG. 4, the horizontal axis is the stroke for pressing the bumper force X, and the vertical axis is the load at that time. In the experiment, the bumper force X was pushed to a certain stroke using the pressing member to cause plastic deformation, and then the pressing member was retracted to reduce the load.

As a result, there was almost no difference in the collision performance between the bumper force X of the present invention and the bumper force X of the comparative example.
This is considered to be because the buckling deformation of the bumper force X at the time of collision greatly affects the strength of the boundary portion 13 where the wall portion 11 and the connection wall portion 12 in the hollow member 10 are connected. That is, the buckling strength of the wall portion 11 in the vicinity of the boundary portion 13 is considered to be the most important for deformation, but by providing the resin material portion 40 only in the vicinity of the boundary portion 13, It is considered that the strength is improved because the deformation is largely restrained by the thermally foamable resin 41. Therefore, in the portions other than the boundary portion 13, it is considered that the presence or absence of the heat-foamable resin 41 does not affect the collision performance so much.

When a plurality of spacers 30 are provided in the long space of the carrier member 20, the rigidity of the entire bumper force X is improved as the installation interval of the spacers 30 is shorter. By setting the installation interval in an appropriate range, the entire bumper force X is deformed flexibly when it collides with another object, and for example, the connection wall portion 12 of the hollow member 10 is difficult to break.
On the other hand, if the installation interval is too short, the rigidity of the bumper force X is further improved. However, at the time of collision with another object, the entire bumper force X becomes difficult to be flexibly deformed, so that the connection wall portion 12 may be broken.

  FIG. 5 shows the results of an experiment examining the collision performance of the bumper force X when the installation interval of the spacer 30 is changed. This experiment was to examine how the bumper force X is deformed when a collision load is applied when the installation interval condition of the rib-shaped spacer 30 is 25 mm and 50 mm.

  As a result, the yield load showed a similar value regardless of whether the installation interval condition was 25 mm or 50 mm. However, when a load is further applied, fracture occurs at a predetermined stroke when the installation interval condition is 25 mm, but no break occurs when the installation interval condition is 50 mm, and the longitudinal direction of the bumper force X Deformation occurred in a wide range along. This deformation could absorb the impact load more effectively.

On the other hand, if the installation interval is too long, the strength of the bumper force X decreases. This is because, when the spacer 30 is not provided, the bumper force X easily causes a cross-sectional deformation and is likely to be bent. An appropriate installation interval is, for example, about 200 mm.
In addition, when the rib-shaped spacer 30 was not disposed, it was recognized that the rib-shaped spacer 30 was deformed with a load about half that when the spacer 30 was disposed.

[Another embodiment]
In the embodiment described above, the spacer 30 is configured to have a plate shape. In this plate-like spacer 30, it is possible to adopt a partially cut-off mode or a hollow-out mode. If it is set as such an aspect, the spacer 30 can be reduced in weight.

Schematic perspective view of the bumper force of the present invention Cross-sectional schematic view of the bumper force of the present invention Schematic perspective view of carrier member The figure which showed the result of the experiment which investigated the collision performance of the bumper force of this invention The figure which showed the result of the experiment which investigated the impact performance of the bumper force when the installation interval of the spacer was changed

X Vehicle bumper force 10 Hollow member 11 Wall portion 12 Connection wall portion 13 Boundary portion 14 Long space 20 Carrier member 21 Carrier wall portion 22 Carrier connection wall portion 30 Spacer 40 Resin material portion 41 Thermal foaming resin 42 Meat extraction Part

Claims (3)

A hollow member provided with at least one long space formed by a pair of opposing wall portions and a pair of connecting wall portions connecting the wall portions;
A carrier member provided with a pair of opposing carrier wall portions, a carrier connecting wall portion connecting the carrier wall portions, and a spacer supporting the pair of carrier wall portions provided in the hollow member. ,
The connection wall and the carrier connection wall are arranged to be on the collision side with other objects,
Among the gaps between the hollow member and the carrier member, a resin material part in which a thermally foamable resin is disposed at a boundary part between at least the wall part and the connection wall part on the collision side with another object ,
A bumper force for a vehicle , wherein the spacer is formed in a rib shape by connecting to the carrier connection wall, and is formed thicker toward the carrier connection wall .   2. The vehicular bumper force according to claim 1, wherein the resin material portion is formed with a thinned portion where the thermally foamable resin is not disposed at least on a collision side with another object.   3. The vehicle bumper force according to claim 1, wherein the spacer is provided at a position corresponding to a region where the thermally foamable resin is disposed in the pair of carrier wall portions.

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