JP4285297B2 - Resin parts for vehicles - Google Patents

Description

The present invention is a resin member for a vehicle that supports a vehicle member to which a collision load from a pedestrian or an occupant can act . In particular, the outer wall of the front portion of the vehicle constitutes a collision load from a pedestrian or an occupant. The present invention relates to a resin member for a vehicle that connects a fender panel and a wheel apron located at a side of an engine room of the vehicle .

For example, in the case of a fender panel that constitutes the outer wall of the front part of an automobile, when a vehicle collides with a pedestrian on its front side, a collision load from the pedestrian acts as a reaction. In other words, in this case, the vehicle exerts a collision load on the pedestrian directly through the fender panel.
Therefore, as a support member that connects and supports this fender panel to a vehicle body member (specifically, for example, a wheel apron located on the side of the engine room of the vehicle), from the viewpoint of protecting pedestrians in the event of an accident It is desirable that its strength is low at the time of collision with a pedestrian. On the other hand, in normal times, high strength and rigidity are required so that the fender panel can be firmly supported with respect to the wheel apron.

Regarding the structure for mounting the fender panel to the vehicle body member, for example, Patent Document 1 discloses a configuration using a resin mounting flange.
JP-A-11-180350

As described above, it is desirable that the supporting member that supports the fender panel with respect to the vehicle body member has a low strength at the time of a collision with a pedestrian. However, when such a support member is made of resin, the resin material generally tends to increase in strength as the strain rate (deformation rate) increases. It is conceivable that the strength becomes higher than when receiving a typical load.
FIG. 8 is a graph showing the relationship between strain rate and tensile strength of various resin materials. In this graph, the relationship between strain rate and tensile strength is shown for polycarbonate (PC) resin, polyamide (PA) 66 / PPE resin, and three types of polypropylene (PP) resins distinguished by A, B, and C on the graph. However, in any of the resins, the strength increases as the strain rate increases.

  On the other hand, in order to reduce the strength at the time of collision load input, a resin material with low impact resistance is used, and a notch (notch) is provided on the support member so that it can be easily broken at the time of collision load input. Conceivable. However, in this case, there is a problem that even in a normal case, the notch may be a starting point and breakage may occur even at a relatively low load.

  As described above, the support member that supports the fender panel with respect to the vehicle body member is required to have strength characteristics that conflict with each other during normal times and when a collision occurs, but it is extremely difficult to satisfy both characteristics at a high level. It was the actual situation. Such a situation applies not only to the support member of the fender panel but also to the support member that supports other vehicle members to which a collision load from a pedestrian or a collision load from an occupant of the own vehicle can act. is there.

  In view of the above situation, the inventors of the present application are intensively researching and developing, and in particular resin materials, specifically, resin materials mixed with natural fibers or glass fibers such as cellulose fibers, It has been found that the tensile strength tends to decrease as the strain rate increases within a certain strain rate range.

Therefore, the present invention is a vehicle in which a collision load from a pedestrian or an occupant can act by utilizing a characteristic that the tensile strength decreases when the strain rate increases in a strain rate range where a specific resin material exceeds a certain level. Resin member for a vehicle that supports the member , in particular, a fender panel that constitutes the outer wall of the front part of the vehicle and can be subjected to a collision load from a pedestrian or an occupant, and a wheel apron located on a side part of the engine room of the vehicle In the resin member for a vehicle that connects the two, a relatively high strength is normally maintained, and the strength can be reduced when a collision load is applied.

For this reason, the resin member for a vehicle according to the present invention comprises a fender panel that constitutes an outer wall of the front portion of the vehicle and can receive a collision load from a pedestrian or an occupant, and a wheel that is positioned at a side portion of the engine room of the vehicle. A resin member for a vehicle that connects with an apron, provided with a load support portion that receives the collision load via the fender panel , and natural fibers are mixed in at least a part of the load support portion, The natural fiber-mixed portion is provided with a strength lowering portion at which the strain rate becomes 1 / second or more when the collision load is applied.

  In this case, the natural fiber is preferably a cellulose fiber.

In addition, the resin member for a vehicle according to another invention of the present application includes a fender panel that constitutes an outer wall of the front portion of the vehicle and can be subjected to a collision load from a pedestrian or an occupant, and a vehicle engine room side portion. A vehicle resin member for connecting a wheel apron to the vehicle, wherein a load support portion for receiving the collision load is provided via the fender panel , and glass fiber is mixed in at least a part of the load support portion. The glass fiber mixed portion is provided with a strength lowering portion at which the strain rate is 400 / second or more when the collision load is applied.

  In the above case, the base material resin is preferably a polypropylene resin, and more preferably, an inorganic filler is further mixed in at least a part of the load support portion. Furthermore, it is still more preferable that the said strength reduction part is set to the deformation | transformation promotion part which promotes a deformation | transformation of a load support part at the time of a collision load effect | action.

According to the first invention of the present application, a fender panel that constitutes the outer wall of the front portion of the vehicle and can be subjected to a collision load from a pedestrian or an occupant is connected to a wheel apron located on a side portion of the engine room of the vehicle. In the vehicle resin member, natural fibers are mixed in at least a part of the load support portion that receives a collision load via the fender panel , and the strain rate is 1 / By providing a strength-decreasing portion that is at least 2 seconds, it maintains a relatively high strength during normal times to ensure the support of the fender panel , while reducing the strength when a collision load acts, Crew protection performance can be improved.

  Here, the lower limit value of the strain rate at the time of the impact load action is set to 1 / second for the above-mentioned strength-decreasing portion. In the strain rate range below this value, the tensile strength tends to decrease as the strain rate increases. This is because it is difficult to stably obtain.

  In this case, when the above natural fiber is specifically made of cellulose fiber, the strain strength at the time of impact load action is 1 / second or more, and the strain strength tends to decrease as the strain rate increases. You can definitely get it.

Further, according to the second invention of the present application, a fender panel that constitutes an outer wall of the front portion of the vehicle and can be subjected to a collision load from a pedestrian or an occupant, and a wheel apron located at a side portion of the engine room of the vehicle, for vehicle resin member for connecting at least a portion of the load bearing portion for receiving the collision load over the fender panel glass fibers are mixed in, in the glass-fiber mixing portion, the strain rate at the time of collision load is applied By providing a strength reduction part that is 400 / sec or more, it is possible to maintain a relatively high strength during normal times to ensure the support of the fender panel , while reducing the strength when a collision load is applied and walking The protection performance of a passenger or passenger can be improved.

  Here, the lower limit value of the strain rate at the time of impact load action is set to 400 / second for the above-mentioned strength-decreasing portion. This is because the tensile strength tends to decrease as the strain rate increases in the strain rate range below this value. This is because it is difficult to stably obtain.

  In the above case, the influence of water absorption can be more effectively suppressed by using polypropylene resin as the base material resin.

  In the above case, the occurrence of “warp” during resin molding can be more effectively suppressed by further mixing an inorganic filler into at least a part of the load support portion.

Furthermore, in the above case, by setting the reduced strength portion in the deformation assisting portion that promotes deformation of the load support portion when a collision load is applied, it is possible to ensure the supportability of the fender panel in a normal state and at the time of the collision occurrence Improvement in the protection performance of pedestrians or passengers can be achieved more effectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Prior to describing a specific application example of the vehicle resin member of the present invention, a resin material used for the resin member will be described.
FIG. 9 is a graph showing the results of measuring the strain rate dependence of tensile strength (that is, the relationship between strain rate and tensile strength) for a resin material in which natural fibers (NF) are blended with a base material (matrix) resin. It is. In the measurement of FIG. 9, the base material resin was a polypropylene (PP) resin, and the natural fibers were cellulose fibers. The strain rate measurement method is the same as a conventionally well-known method.
In the graph of FIG. 9, the solid line curve shows a case where 36% of natural fibers are blended, and the broken line curve shows a case where 18% of natural fibers are blended. Moreover, the dashed-dotted line curve has shown the case where the natural fiber is not mix | blended as a comparative example.

  As can be seen from the graph of FIG. 9, the tensile strength of the material not blended with natural fibers increases as the strain rate increases over the entire measurement range. On the other hand, in the case of blending natural fibers, in the region where the strain rate is up to about 0.1 / second, the tensile strength increases as the strain rate increases, but the strain rate is about 0.00. In the region from 1 / second to about 1 / second, the tensile strength is slightly reduced or leveled off as the strain rate increases. When the strain rate is about 1 / second or more, the tensile strength tends to surely decrease as the strain rate increases. This decreasing tendency appears more strongly when the blending amount of natural fibers is large.

  Therefore, when manufacturing a vehicle resin member that supports a vehicle member (for example, a fender panel) on which a vehicle member (for example, a fender panel) that can receive a collision load from a pedestrian or a passenger is manufactured, The natural fiber is mixed into at least a part of the load supporting part that receives the load, and the natural fiber mixed part is provided with a strength-reducing part in which the strain rate becomes 1 / second or more when a collision load is applied, so that the strength is normally relatively high. While maintaining the support of the vehicle member, the strength when the collision load is applied can be reduced to improve the protection performance of the pedestrian or the occupant.

In this case, by setting the lower limit value of the strain rate when the collision load is applied to the above-described strength-decreasing portion, the characteristic that the tensile strength tends to decrease as the strain rate increases can be stably obtained.
In this case, the natural fiber is specifically a cellulose fiber, so that when the strain rate at the time of impact load action is 1 / second or more, the tensile strength decreases as the strain rate increases. It can be obtained more reliably.
Further, in this case, the adverse effect due to water absorption can be effectively suppressed by using PP resin as the base material resin.

Next, FIG. 10 is a graph showing the results of measuring the relationship between strain rate and tensile strength for a resin material in which glass fiber (GF) is blended with a base resin. Also in the measurement of FIG. 10, polypropylene (PP) resin was used as the base material resin from the viewpoint of effectively suppressing the adverse effects due to water absorption.
In the graph of FIG. 10, the solid line curve indicates a case where 40% of glass fiber is blended. The broken line curve shows a case where 10% glass fiber and further 10% inorganic filler (M) are blended. This inorganic filler is made of, for example, mineral or talc, and is blended from the viewpoint of suppressing the occurrence of “warping” during molding. Moreover, the dashed-dotted line curve has shown the case where the glass fiber is not mix | blended as a comparative example.

  As can be clearly seen from the graph of FIG. 10, the tensile strength increases as the strain rate increases for the entire measurement range for the glass fiber not blended. On the other hand, in the case where the glass fiber is blended, in the region where the strain rate is up to about 200 / second, the tensile strength increases as the strain rate increases, but the strain rate is about 200 / second. In particular, in the range of about 400 / second or more, the tensile strength tends to surely decrease as the strain rate increases. This downward tendency appears more strongly as the glass fiber content is larger.

FIG. 11 is a graph showing the results of measuring the relationship between the strain rate and the tensile strength of a resin material in which a polyamide (PA) resin is used as a base material resin and glass fibers (GF) are blended therein.
In the graph of FIG. 11, the solid line curve indicates a case where 33% glass fiber is blended, and the one-dot chain line curve indicates a case where glass fiber is not blended as a comparative example.

  As can be seen from the graph of FIG. 11, the tensile strength of the glass fiber not blended increases as the strain rate increases over the entire measurement range. On the other hand, in the case where the glass fiber is blended, in the region where the strain rate is up to about 400 / second, the tensile strength increases as the strain rate increases, but the strain rate is about 400 / second or more. Then, the tensile strength tends to surely decrease as the strain rate increases.

  Therefore, when manufacturing a vehicle resin member that supports a vehicle member (for example, a fender panel) on which a vehicle member (for example, a fender panel) that can receive a collision load from a pedestrian or a passenger is manufactured, A glass fiber is mixed in at least a part of the load supporting portion that receives the strength, and a reduced strength portion having a strain rate of 1 / second or more when a collision load is applied is provided in the glass fiber mixed portion. While maintaining the support of the vehicle member, the strength when the collision load is applied can be reduced to improve the protection performance of the pedestrian or the occupant.

In this case, by setting the lower limit value of the strain rate when the collision load is applied to the above-described strength-decreasing portion to 400 / second, it is possible to stably obtain the characteristic that the tensile strength tends to decrease as the strain rate increases.
Also in this case, the adverse effect due to water absorption can be effectively suppressed by using PP resin as the base material resin.

  Furthermore, in addition to natural fibers or glass fibers, for example, an inorganic filler such as mineral or talc can be blended to suppress the occurrence of “warp” during molding.

Next, specific application examples (examples) of the vehicle resin member of the present invention molded using the resin material as described above will be described.
<Example>

FIG. 1 is an overall perspective view of an automobile according to the present embodiment, and FIG. 2 is a perspective view of a front fender panel (for example, the left side) of the automobile.
As shown in FIG. 1, the left and right side portions of the vehicle front portion of the automobile 1 according to the present embodiment are covered with a front fender panel 5 that constitutes an outer wall of the vehicle front side portion except for a wheel (front wheel) 3 portion. ing. These fender panels 5 are connected to and supported by a vehicle body member (specifically, a wheel apron located on the side of the engine room of the vehicle) via a connection bracket described later.

FIG. 3 is a perspective view showing a front end portion of the connecting bracket 10 for connecting the fender panel 5 on the right side of the vehicle to a reinforcing member 7 (apron reinforcement) of a wheel apron (not shown) and the vicinity thereof.
In this embodiment, the apron reinforcement 7 is formed in a rectangular cylindrical shape using, for example, a steel plate, and extends in the vehicle front-rear direction. On the other hand, the fender panel 5 is made of, for example, a steel plate or an aluminum plate. The fender panel 5 itself may be made of a synthetic resin.

  As shown in FIG. 3, a bent portion 5 b for attaching the fender panel 5 to the connection bracket 10 is formed at the upper end of the fender panel 5, and the upper end bent of the fender panel 5 is formed at the upper end portion of the connection bracket 10. The rail part 11 which receives the part 5b is formed. On the other hand, a vertical wall-shaped mounting base 16 is formed on the lower end side of the connecting bracket 10 in order to be fixed to the apron reinforcement 7. A first vertical wall 12, a horizontal plate portion 13, a second vertical wall 14, and an inclined wall portion 15 are provided between the mounting base portion 16 and the rail portion 11 in order from the upper side.

  As described above, when the automobile 1 collides with a pedestrian at the front side, a collision load from the pedestrian acts as a reaction. In other words, in this case, the automobile 1 directly exerts a collision load on the pedestrian via the front fender panel 5, so the fender panel 5 is applied to the apron reinforcement 7. The connecting bracket 10 to be connected and supported is preferably low in strength at the time of collision with a pedestrian from the viewpoint of pedestrian protection when an accident occurs. On the other hand, in a normal state, high strength and rigidity are required so that the fender panel 5 can be firmly supported with respect to the wheel apron (that is, the apron reinforcement 7).

In this case, most of the connecting bracket 10 (for example, the portion excluding the outer wall of the rail portion 11) acts as a load support portion that receives a collision load via the fender panel 5.
Therefore, the entire connecting bracket 10 is made of a synthetic resin material blended with natural fibers or glass fibers as described above. In this case, as the base material resin, PP resin is preferable from the viewpoint of suppressing the influence of water absorption, and further, inorganic fillers such as mineral and talc are mixed together from the viewpoint of suppressing warpage during molding. More preferable.

  Moreover, the said connection bracket 10 is formed with the vertical walls 12 and 14, the horizontal board part 13, and also the inclination wall part 15, and those boundary parts comprise bending part (or corner | angular part) C1-C4. is doing. In such bent portions (or corner portions) C1 to C4, load concentration is likely to occur when a collision load is input, and therefore deformation is easily promoted. Moreover, in this connection bracket 10, the inclined wall part 15 comprises the comparatively big plane, and there exists a tendency for a deformation | transformation to be promoted also at such a big plane at the time of a collision.

That is, the curved portions (or corner portions) C1 to C4 and the inclined wall portion 15 themselves constitute a deformation promoting portion that promotes deformation of the load support portion when a collision load is applied. When a bending load is applied to these deformation assisting portions, breakage occurs relatively easily from the tension side.
If the fender panel 5 is simply connected to the apron reinforcement 7 without considering the deformation characteristics as in the present invention, the shape of the connection bracket is shown by a one-dot chain line in FIG. In addition, the shape can be made very simple.

  In the present embodiment, the shape of the connecting bracket 10 is such that at least one of these deformation assisting portions, for example, the corner portion C1 or the inclined wall portion 15 constitutes a strength decreasing portion where the strain rate becomes a certain level or more when a collision load is applied. And dimensions are set. In particular, it is more preferable that the strain speed is set to be equal to or higher than the above-described constant value when a collision occurs while the automobile 1 is traveling at a speed of 30 km / hr or higher.

When the natural fiber is mixed, the reduced strength portion is set so that the strain rate becomes 1 / second or more when the collision load is applied, and when the glass fiber is mixed, the collision load is set. The strain rate is set to be 400 / second or more during operation.
Therefore, in the strength reduction portion, in a region where the strain rate is equal to or higher than the predetermined value (1 / second or 400 / second), the tensile strength is surely reduced as the strain rate is increased.

  With the above-described configuration, the connection bracket 10 that supports the fender panel 5 that can be subjected to a collision load from a pedestrian normally maintains a relatively high strength and ensures supportability of the fender panel 5. On the other hand, the protection performance of a pedestrian can be improved by reducing the strength when a collision load is applied.

In this case, if the natural fiber is specifically made of cellulose fiber, the characteristic that the tensile strength tends to decrease as the strain rate increases in the region where the strain rate at the time of impact load action is 1 / second or more is more reliable. Can get to.
Moreover, the influence by water absorption can be suppressed more effectively by using the base resin as a polypropylene resin. Furthermore, the occurrence of “warp” during resin molding can be more effectively suppressed by mixing the inorganic filler together.

  Furthermore, by setting the reduced strength portion in the deformation assisting portion that promotes deformation of the load support portion when a collision load is applied, it is possible to ensure the support of the vehicle member in a normal state and a pedestrian or occupant at the time of the collision occurrence. The improvement of the protection performance can be achieved in a more effective manner.

  In the above-described embodiment, the entire connection bracket 10 is formed of a synthetic resin blended with natural fibers or glass fibers. Instead, at least a part of the load support portion of the connection bracket 10, particularly, Further, it may be molded so that natural fiber or glass fiber is mixed only in the deformation promoting part.

Next, as a reference example of this embodiment, the present invention is applied to a resin member that supports other vehicle members that may collide with pedestrians, and further vehicle members that may collide with occupants as well as pedestrians. The applied example will be described.
<Reference Example 1>

FIG. 4 is a perspective view of the headlamp unit 20 disposed on the front end side portion of the vehicle according to the first reference example . In the case of the headlamp unit 20 as well, a pedestrian may collide with the front glass 21. Accordingly, the resin lamp housing 22 that supports the front glass 21 and the internal headlamp (not shown) also maintains a relatively high strength during normal times, while the strength decreases when a collision load is applied. It is desirable.

Therefore, the lamp housing 22, as in the case in Example described above, by applying the synthetic resin containing a natural fiber or glass fibers, have the desired strength characteristics at normal and at the time of collision load acting Can be made. In this case, for example, at least one of the corner portions C11 to C13 may be set as the strength reduction portion.
<Reference Example 2>

FIG. 5 is a perspective view showing a vehicle wiper support mechanism 30 according to Reference Example 2. As shown in FIG. In the case of this wiper support mechanism 30, the wiper pivot 31 itself connected to the wiper motor (not shown) is a rigid body. Deal more damage. Therefore, it is desirable that the resin support bracket 32 that supports the wiper pivot 31 also maintain a relatively high strength during normal times, but reduce the strength when a collision load is applied.

Therefore, the support bracket 32, similarly to the case in Example described above, by applying the synthetic resin containing a natural fiber or glass fibers, have the desired strength characteristics at normal and at the time of collision load acting Can be made. In this case, for example, at least one of the bent portions C21 and C22 may be set as the strength reduction portion.
<Reference Example 3>

FIG. 6 is a perspective view showing a bonnet hinge mechanism 40 of a vehicle according to Reference Example 3 . In the case of this bonnet hinge mechanism 40, it is conceivable that a secondary collision with a pedestrian (particularly its head) occurs as a result of a pedestrian colliding with the front or front side of the vehicle riding on the hood. Accordingly, it is desirable that the resin hinge bracket 42 supporting the hinge arm 41 is maintained at a relatively high strength during normal times, but is reduced in strength when a collision load is applied.

Therefore, the hinge bracket 42, similarly to the case in Example described above, by applying the synthetic resin containing a natural fiber or glass fibers, have the desired strength characteristics at normal and at the time of collision load acting Can be made. In this case, for example, at least one of the bent portions C31 to C33 may be set as the strength reduction portion.
<Reference Example 4>

FIG. 7 is a perspective view showing a hood stop rubber support mechanism 50 for a vehicle according to Reference Example 4. FIG. In the case of this bonnet stop rubber support mechanism 50, as in the case of the reference example 3 , as a result of a pedestrian colliding with the front part or the front side part of the vehicle riding on the bonnet, the secondary with the pedestrian (particularly its head) It is conceivable that a typical collision will occur. Accordingly, it is more desirable that the resin-made support bracket 52 that supports the stop rubber 51 also maintain a relatively high strength in a normal state, while reducing the strength when a collision load is applied.

Therefore, the support bracket 52, similarly to the case in Example described above, by applying the synthetic resin containing a natural fiber or glass fibers, have the desired strength characteristics at normal and at the time of collision load acting Can be made. In this case, for example, at least one of the bent portions C41 to C44 may be set as the strength reduction portion.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various modifications and improvements can be made without departing from the scope of the invention.

It is an overall perspective view of a vehicle according to an embodiment of the present invention. It is a perspective view of the front fender panel of the above-mentioned car. It is a perspective view which shows the front-end part of the connection bracket which connects the said front fender panel to an apron reinforcement, and its vicinity. FIG. 6 is a perspective view of a vehicle headlamp unit according to Reference Example 1 . It is a perspective view which shows the wiper support mechanism of the vehicle which concerns on the reference example 2. FIG. It is a perspective view which shows the bonnet hinge mechanism of the vehicle which concerns on the reference example 3. FIG. It is a perspective view which shows the bonnet stop rubber support mechanism of the vehicle which concerns on the reference example 4. FIG. It is the graph which showed the relationship between the strain rate and tensile strength of various resin materials. It is the graph which showed the relationship between the strain rate and tensile strength of PP resin which mix | blended natural fiber. It is the graph which showed the relationship between the strain rate and tensile strength of PP resin which mix | blended glass fiber. It is the graph which showed the relationship between the strain rate and tensile strength of PA resin which mix | blended glass fiber.

DESCRIPTION OF SYMBOLS 1 Automobile 5 Front fender panel 10 Connection bracket 15 Inclined wall part 20 Head lamp unit 22 Lamp housing 30 Wiper support mechanism 32 Support bracket 40 Bonnet hinge support mechanism 42 Hinge bracket 50 Bonnet stop rubber support mechanism 52 Support bracket C1-C4, C11 C13, C21, C22, C31 to C33, C41 to C44 Bent part (or corner part)

Claims (6)

A vehicular resin member that connects a fender panel that constitutes an outer wall of the front portion of the vehicle and can be subjected to a collision load from a pedestrian or an occupant, and a wheel apron located at a side of an engine room of the vehicle,
A load support is provided for receiving the collision load via the fender panel ;
Natural fibers are mixed in at least a part of the load support part,
The natural fiber-mixed part is provided with a strength-decreasing part at which the strain rate becomes 1 / second or more when the collision load is applied.
A resin member for a vehicle.   2. The resin member for a vehicle according to claim 1, wherein the natural fiber is a cellulose fiber. A vehicular resin member that connects a fender panel that constitutes an outer wall of the front portion of the vehicle and can be subjected to a collision load from a pedestrian or an occupant, and a wheel apron located at a side of an engine room of the vehicle,
A load support is provided for receiving the collision load via the fender panel ;
Glass fiber is mixed in at least a part of the load support part,
The glass fiber mixed portion is provided with a strength reduction portion at which the strain rate is 400 / second or more when the collision load is applied.
A resin member for a vehicle.   The vehicle resin member according to any one of claims 1 to 3, wherein the base material is a polypropylene resin.   The vehicle-made resin member according to any one of claims 1 to 4, wherein an inorganic filler is further mixed in at least a part of the load support portion. The resin-made member for a vehicle according to any one of claims 1 to 5, wherein the strength reduction portion is set as a deformation promoting portion that promotes deformation of the load support portion when the collision load is applied. .

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