Vehicle front structure

When a load caused by a collision is transmitted from the front side of a vehicle, tire cutout portions of front side members are deformed by the load transmitted from the front side of the vehicle. Accordingly, the tire cutout portions of the front side members come into contact with a power unit formed of an engine or the like of the vehicle, switch a transmission path of the load to a direction corresponding to the power unit of the vehicle, and transmit the load to the power unit as a load. The tire cutout portion is formed between two engine mounts. Accordingly, a starting point from which the front side member begins to be deformed is set between the engine mounts that are two supported portions of the power unit, so that the stable bending and deformation of the front side member are controlled. Further, a transmission path of a load toward the power unit is newly formed. Accordingly, a load, which is caused by a collision or the like and transmitted from the front side of the vehicle, is dispersed on the power unit that is hard and has large mass. As a result, it is possible to increase efficiency of absorbing impact at the time of a collision.

TECHNICAL FIELD

The present invention relates to a vehicle front structure, and more particularly, to a vehicle front structure that includes side members provided at side end portions of the vehicle and extending in a front-rear direction of the vehicle.

BACKGROUND ART

Vehicle front structures considering safety at the time of a collision have been proposed. For example, Patent Literature 1 discloses a vehicle front structure where front areas of side members are formed so as to be inclined to the outside in a vehicle width direction toward the front side of a vehicle body. Sub-side members are provided at the front areas of the side members, and front end portions of the sub-side members are connected to the rear surface of a bumper reinforcement. Each of the sub-side members is provided with a deformation mode control mechanism that bends the sub-side member inward in the vehicle width direction by the input of a collision so as to make the sub-side member interfere with a power unit. Accordingly, the vehicle front structure disclosed in Patent Literature 1 reduces the deformation of a vehicle body by inducing and facilitating the rigid movement of a vehicle in a lateral direction at the time of a small overlap collision.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

Meanwhile, an effect capable of transmitting a load to the power unit by the sub-side members may be generated in the above-mentioned technique. However, in the above-mentioned technique, there is no stroke that absorbs impact and the absorption of a load is insufficient. Further, in the above-mentioned technique, deformation is not stable when a load is applied to the side members, and there is a low possibility that a load can be stably transmitted to the power unit.

The invention has been made in consideration of the above-mentioned circumstances, and an object of the invention is to provide a vehicle front structure that can reduce a load to be applied to a vehicle at the time of a collision or the like.

Solution to Problem

According to the invention, there is provided a vehicle front structure that forms a framework of a vehicle front portion. The vehicle front structure includes side members that are provided at side end portions of the vehicle and extend in a front-rear direction of the vehicle. Each of the side members absorbs a load by being crushed at a front portion of the side member in the front-rear direction of the vehicle by the load transmitted from the front side of the vehicle, and includes a load transmission path switching portion that switches a transmission path of the load to the side of the vehicle by being deformed by the load transmitted to a rear portion of the side member.

According to this structure, a vehicle front structure, which forms a framework of a vehicle front portion, includes side members that are provided at side end portions of the vehicle and extend in a front-rear direction of the vehicle. Each of the side members absorbs a load by being crushed at a front portion of the side member in the front-rear direction of the vehicle by the load transmitted from the front side of the vehicle. Accordingly, it is possible to absorb impact at the time of a collision or the like. In addition, each of the side members includes a load transmission path switching portion that switches a transmission path of the load to the side of the vehicle by being deformed by the load transmitted to a rear portion of the side member. Accordingly, a load, which is caused by a collision or the like and transmitted from the front side of the vehicle, is dispersed in the lateral direction of the vehicle, so that it is possible to increase efficiency of absorbing impact at the time of a collision.

Further, according to the invention, there is provided a vehicle front structure that forms a framework of a vehicle front portion. The vehicle front structure includes side members that are provided at side end portions of the vehicle and extend in a front-rear direction of the vehicle. Each of the side members includes a load transmission path switching portion. The load transmission path switching portion comes into contact with a power unit formed of any one of a battery, an inverter, a motor, and an engine of the vehicle by being deformed by a load transmitted from the front side of the vehicle; switches a transmission path of the load to a direction corresponding to the power unit of the vehicle; and is formed between two supported portions of the power unit.

According to this structure, a vehicle front structure, which forms a framework of a vehicle front portion, includes side members that are provided at side end portions of the vehicle and extend in a front-rear direction of the vehicle. Each of the side members includes a load transmission path switching portion. The load transmission path switching portion comes into contact with a power unit formed of an engine or the like of the vehicle by being deformed by a load transmitted from the front side of the vehicle, switches a transmission path of the load to a direction corresponding to the power unit of the vehicle, and is formed between two supported portions of the power unit. Accordingly, a starting point from which the side member begins to be deformed is set between the two supported portions of the power unit, so that the stable bending and deformation of the side member are controlled. Further, a transmission path of a load toward the power unit is newly formed. Accordingly, a load, which is caused by a collision or the like and transmitted from the front side of the vehicle, is dispersed on the power unit that is hard and has large mass. As a result, it is possible to increase efficiency of absorbing impact at the time of a collision.

In this case, the transmission path of the load may be formed by the contact between the deformed load transmission path switching portion and the power unit that is formed of any one of the battery, the inverter, the motor, and the engine of the vehicle.

According to this structure, the transmission path of the load is formed by the contact between the deformed load transmission path switching portion and the power unit formed of an engine or the like. Accordingly, a load, which is caused by a collision or the like and transmitted from the front side of the vehicle, is dispersed, so that it is possible to increase efficiency of absorbing impact at the time of a collision.

Further, the load transmission path switching portion may be a recess that corresponds to the trace of a front wheel of the vehicle changed during steering.

According to this structure, the load transmission path switching portion is a recess that corresponds to the trace of a front wheel of the vehicle changed during steering. For this reason, it is possible to more stably deform the load transmission path switching portion by a load transmitted from the front side of the vehicle. Furthermore, since the load transmission path switching portion deformed by a load is used as the recess corresponding to the trace of the front wheel of the vehicle that is changed during steering, it is possible to efficiently form a load transmission path switching portion without separately forming a load transmission path switching portion. In addition, recesses, which correspond to the trace of the front wheels of the vehicle changed during steering, are formed at the side members as the load transmission path switching portions, so that the front wheels of the vehicle are received in a smaller area. Accordingly, it is possible to increase the degree of freedom of the design such as the enlargement of the area where an engine is received.

Moreover, the load transmission path switching portion may be a recess that corresponds to the trace of a front wheel of the vehicle changed during steering. The two supported portions of the power unit may be provided on each of the side members. When distances between a foot of a perpendicular to a straight line, which connects the two supported portions, from a deepest portion of the recess and the supported portions are denoted by a and b, respectively, a distance where each of the supported portions can be moved by the load is denoted by x, and a distance between the supported portion and the power unit is denoted by y, “y≦[x(a+b−x)]1/2” may be satisfied.

According to this structure, the load transmission path switching portion is the recess that corresponds to the trace of the front wheel of the vehicle changed during steering, and the two supported portions of the power unit are provided on each of the side members. For this reason, it is possible to more stably deform the load transmission path switching portion by a load transmitted from the front side of the vehicle. Further, since the load transmission path switching portion deformed by a load is used as the recess corresponding to the trace of the front wheel of the vehicle that is changed during steering, it is possible to efficiently form a load transmission path switching portion without separately forming a load transmission path switching portion.

In addition, recesses, which correspond to the trace of the front wheels of the vehicle changed during steering, are formed at the side members as the load transmission path switching portions, so that the front wheels of the vehicle are received in a smaller area. Accordingly, it is possible to increase the degree of freedom of the design such as the enlargement of the area where an engine is received. When distances between a foot of a perpendicular to a straight line, which connects the two supported portions, from the deepest portion of the recess and the supported portions are denoted by a and b, respectively, a distance where each of the supported portions can be moved by the load is denoted by x, and a distance between the supported portion and the power unit is denoted by y, “y≦[x(a+b−x)]1/2” is satisfied. Accordingly, it is possible to make the recess be deformed without fracturing the supported portions of the power unit.

Further, according to the invention, there is provided a vehicle front structure that forms a framework of a vehicle front portion. The vehicle front structure includes side members that are provided at side end portions of the vehicle and extend in a front-rear direction of the vehicle. Each of the side members includes a load transmission path switching portion that switches a transmission path of the load to the side of the vehicle by being deformed by the load transmitted to a rear portion of the side member.

According to this structure, a vehicle front structure, which forms a framework of a vehicle front portion, includes side members that are provided at the side end portions of the vehicle and extend in the front-rear direction of the vehicle. Each of the side members includes a load transmission path switching portion that switches a transmission path of the load to the side of the vehicle by being deformed by the load transmitted to the rear portion of the side member. Accordingly, a load, which is caused by a collision or the like and transmitted from the front side of the vehicle, is dispersed in the lateral direction of the vehicle, so that it is possible to increase the efficiency of absorbing impact at the time of a collision.

Advantageous Effects of Invention

According to the vehicle front structure of the invention, it is possible to increase the efficiency of absorbing impact at the time of a collision.

DESCRIPTION OF EMBODIMENTS

Embodiments of the invention will be described below with reference to the drawings. As shown inFIG. 1, a vehicle front structure according to a first embodiment of the invention includes a pair of front side members10. Each of the pair of front side members10is provided with two engine mounts11. A total of four engine mounts11support a power unit20that includes a battery, an inverter, a motor, and an engine of a vehicle. Each of the engine mounts11includes a rubber bush. The engine mounts11support the power unit20by the rubber bushes so that the power unit20can be moved relative to the front side members10by only a certain amount of play. As shown inFIG. 2, the power unit20is also supported from below by a center member30.

As shown inFIG. 2, a radiator40is positioned at the front ends of the front side members10. Crash boxes41and42are provided in the front of the radiator40. When a vehicle collides at the front portion thereof, the crash boxes41and42are crushed and absorb impact. As shown inFIG. 3, a front bumper reinforcement43is provided over the front ends of the pair of front side members10. Further, a sub-frame44is provided in the rear of the front bumper reinforcement43over the front ends of the pair of front side members10.

As shown inFIGS. 1 to 3, two tire cutout portions12are formed on the outer surface of each of the pair of front side members10. As shown inFIG. 3, the tire cutout portions12are cut out with a depth where the front side member10does not come into contact with a tire50of the front wheel of which the direction is changed during the steering. That is, the tire cutout portion12has the shape corresponding to the trace of the tire50of the front wheel that is changed during the steering. Further, the front tire cutout portion12is formed between the two engine mounts11. The cut-out shape of each tire cutout portion12is symmetric in the front-rear direction of the front side member10as seen from the upper side of the vehicle.

As shown inFIGS. 4 and 5, a distance between the support center PAand PBof the engine mounts11is denoted by l. A distance where each of the engine mounts11can be moved by a load is denoted by x. Further, a distance between the engine mount11and the power unit20is denoted by y.

As shown inFIG. 6, the values of l, x, and y satisfy a right triangle that has a side having a length of (½−x) and a side having a length of y as adjacent sides with a right angle interposed therebetween and has a side having a length of ½ as an oblique side. Accordingly, when a load is applied, the engine mounts11are moved in the ranges of the lengths x of the play thereof and the front side members10may be bent and come into contact with the power unit20.

Here, “y={x(1−x)}1/2” is obtained from “y2+(½−x)2=(½)2”. Alternatively, if “y<{x(1−x)}1/2” is satisfied, the distance y between the engine mount11and the power unit20may be set shorter.

The operation of the vehicle front structure according to this embodiment will be described below. When a load F1caused by a collision is transmitted from the front side of the vehicle as shown inFIG. 7, the tire cutout portions12of the front side members10are deformed by the load F1transmitted from the front side of the vehicle. Accordingly, the tire cutout portions12of the front side members10come into contact with the power unit20formed of the engine or the like of the vehicle, switch a transmission path of the load to a direction corresponding to the power unit20of the vehicle, and transmit the load F1to the power unit20as a load F2. As described above, the tire cutout portion12is formed between the two engine mounts11. Accordingly, a starting point from which the front side member10begins to be deformed is set between the engine mounts11that are two supported portions of the power unit20, so that the stable bending and deformation of the front side member10are controlled. Further, a transmission path of a load toward the power unit20is newly formed. Accordingly, a load, which is caused by a collision or the like and transmitted from the front side of the vehicle, is dispersed on the power unit20that is hard and has large mass. As a result, it is possible to increase efficiency of absorbing impact at the time of a collision.

Further, in this embodiment, the front side members10absorb the load by being crushed at the front portions of the front side members10in the front-rear direction of the vehicle by the load transmitted from the front side of the vehicle. Accordingly, it is possible to absorb the impact at the time of a collision or the like.

Furthermore, the tire cutout portions12, which correspond to the traces of the tires50of the front wheels of a vehicle changed during the steering, are formed at the portions of the front side members10that are to be deformed by a load. Accordingly, it is possible to efficiently form portions, which switch a transmission path of a load, without separately forming deformable portions.

Here, if tire cutout portions12are not formed as shown in FIG.8, both left and right front side members10need to be positioned in the middle portion of a vehicle so that the front side members10do not come into contact with tires50of front wheels of which the directions are changed during the steering. In this case, an area where a power unit20is received is reduced.

Meanwhile, if tire cutout portions12, which correspond to the traces of tires50of front wheels of a vehicle changed during the steering, are formed at front side members10as in this embodiment, the tires50of the front wheels of the vehicle are received in a smaller area. Accordingly, it is possible to increase the degree of freedom of the design such as the enlargement of the area where the power unit20is received.

Moreover, in this embodiment, it is possible to make the tire cutout portions12be deformed without fracturing the engine mounts11, which support the power unit20, by making the dimensions of the respective portions satisfy “y≦{x(1−x)}1/2”. Meanwhile, in this embodiment, the dimensions of the respective portions may be made to satisfy “y>{x(1−x)}1/2” in order to absorb impact even though the engine mounts11are fractured.

A second embodiment of the invention will be described below. As shown inFIG. 9, in this embodiment, the cut-out shape of a tire cutout portion12is asymmetric in the front-rear direction of the front side member10as seen from the upper side of a vehicle. Distances between a foot of a perpendicular to a straight line, which connects two engine mounts11of a power unit20, from the deepest portion of a recess of the tire cutout portion12and the engine mounts11are denoted by a and b, respectively. A distance where each of the engine mounts11can be moved by a load is denoted by x, and a distance between the engine mount11and the power unit20is denoted by y.

It may be supposed that a right triangle that has a side having a length of y and a side having a length of (a−x) as adjacent sides and has a side having a length of a as an oblique side, and a right triangle that has a side having a length of y and a side having a length of (b−x) as adjacent sides and has a side having a length of b as an oblique side are formed as shown inFIG. 10at the time of the bending of the front side member10. “y2+(a−x)2=a2” and “y2+(b−x)2=b2” are satisfied by this. When both sides of these expressions are added to each other, “2y2+(a−x)2+(b−x)2=a2+b2” is obtained. “2y2=a2+b2−(a−x)2−(b−x)2” is obtained through transposition. “y={x(a+b−x)}1/2” can be obtained from this. Alternatively, if “y<{x(a+b−x)}1/2” is satisfied, the distance y between the engine mount11and the power unit20may be set shorter.

The front side members10including the above-mentioned tire cutout portions12of the second embodiment, which are asymmetric in the front-rear direction, also exhibit the same operation as the operation of the first embodiment. In this embodiment, when distances between a foot of a perpendicular to a straight line, which connects two engine mounts11, from the deepest portion of the recess of the tire cutout portion12and supported portions are denoted by a and b, respectively, a distance where each of the engine mounts11can be moved by a load is denoted by x, and a distance between the engine mount11and the power unit20is denoted by y, “y≦[x(a+b−x)]1/2” is satisfied. For this reason, it is possible to make the tire cutout portions12be deformed without fracturing the engine mounts11that support the power unit20. Meanwhile, in this embodiment, the dimensions of the respective portions may be made to satisfy “y>{x(a+b−x)}1/2” in order to absorb impact even though the engine mounts11are fractured.

The embodiments of the invention have been described above. However, the invention is not limited to the above-mentioned embodiments and may have various modifications.

INDUSTRIAL APPLICABILITY

According to the vehicle front structure of the invention, it is possible to increase efficiency of absorbing impact at the time of a collision.

REFERENCE SIGNS LIST