JP3289629B2 - Body front structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front structure of a vehicle body provided with a bumper at a front end of left and right side members of the vehicle,
The present invention relates to a front structure of a vehicle body having a function of mitigating an impact at the time of collision with an obstacle by deformation of the front part of the vehicle body.

[0002]

2. Description of the Related Art Conventionally, a vehicle body such as an automobile is composed of a frame on which an unsprung member, a power plant, and the like are mounted, and a body mounted on an upper side thereof. As this kind of vehicle body, a type with a frame in which the frame and the body are formed independently and integrated, and a frameless type with a part in which the frame and the body are mutually shared parts are known, Both types have left and right side members extending in the front-rear direction on both left and right sides of the front part of the vehicle body, and front and rear ends of the left and right side members are fitted with bumpers long in the left-right direction of the vehicle.

[0003] In many cases, the bumper is composed of only a rigid bar-like member or a pad member made of an elastic material covering the surface of the rigid bar. The bumper is elastically or plastically deformed at the time of a vehicle collision, thereby reducing the impact received by the occupant and protecting the occupant. However, since the collision of the vehicle occurs in a wide range of speeds, if the collision energy of the vehicle is large, it is difficult to sufficiently reduce the impact received by the occupant using only the bumper. Therefore, the front part of the frame and the body from the cabin is formed so as to be easily plastically deformed, and the front part of the vehicle body is plastically deformed at the time of a collision of the vehicle, absorbing the collision energy at the time of the collision and mitigating the impact to reduce the impact to the occupant. To ensure safety.

For example, in Japanese Patent Publication No. 55-50810, a pair of side members are formed by opening the front end portions thereof in an eight-shape, and a cross member is provided between the front end portions. The second cross member is erected in parallel at the various parts, and the two cross members are connected by a bulge-formed metal pipe arranged in the front-rear direction, and the front surface of the cross member is connected via a collision energy absorbing elastic body. A front structure of a vehicle body is disclosed in which a bumper is provided and a reinforcing member is fixed to a main part of the side member along an axial direction of the side member.

In the front structure, at the time of a vehicle collision, the bumper and the collision energy absorbing elastic body absorb the collision energy, and the front portion of the side member is buckled and deformed to absorb the collision energy. We are ensuring safety. The behavior of the vehicle body during a vehicle collision has been studied by various types of collision tests.In this collision test, for example, data on whether or not the collision energy can be efficiently absorbed by plastic deformation of the front part of the vehicle body of the test vehicle, etc. In addition, data such as how much the crash space (survival space) is reduced by deformation of the front part of the vehicle body are taken. By the way, when a vehicle collides with an obstacle, it does not always collide at the center position of the bumper. Rather, the ratio of collision with an obstacle occurring at a position shifted from the center position of the bumper is larger.

When a vehicle has an offset collision with an oncoming vehicle V, the offset collision load is applied to one side of the bumper 4, as shown in FIG. Bending deformation and deformation of the part from the front part of the body 5 to the cabin proceed, and the offset collision load W is guided sufficiently to the side member 3 to buckle and deform the side member, thereby absorbing collision energy. Can not do. In this case, in particular, the span L of the left and right side members
In a narrow vehicle, the offset collision load W is applied so as to bend the left and right end sides of the bumper, so that the side member 3 is easily bent, and the side member is sufficiently buckled to absorb the collision energy sufficiently. I can't do that. As a result, the impact received by the occupant cannot be reduced sufficiently, the front part of the vehicle body is relatively easily deformed, and the crash space (survival space) is narrowed.

Therefore, a structure has been proposed in which the offset collision load received by the left and right ends of the bumper can be guided to the side members. For example, in the front structure of a vehicle body disclosed in Japanese Patent Application Laid-Open No. 7-187033, an auxiliary member is extended obliquely forward from the front outside of the left and right side members, and the front end is fixed to the side end of the bumper. Thereby, the offset collision load from the left and right ends of the bumper can be guided to the side members. In this case, when the vehicle body receives an offset collision load, the auxiliary member buckles and deforms, so that the impact received by the occupant can be reduced.

[0008]

However, in the case of a conventional front structure of a vehicle body, for example, the front structure of a vehicle body disclosed in Japanese Patent Publication No. 55-50810, if the offset collision load is small, the collision position of the bumper will be reduced. The offset collision load received at is transmitted to the collision energy absorbing elastic body and the bulge-formed metal pipe, where it is absorbed.However, if the offset collision load is large, the left and right ends of the bumper also bend and the front of the body Since the buckling load cannot be transmitted to the energy absorbing region set behind the side member because of being greatly crushed, the collision energy absorption amount on the side member side can be reduced. In addition, in the case of this prior example, since the configuration is such that the second cross member is provided, there is a problem that the cost is increased.

Further, in the front structure of the vehicle body disclosed in Japanese Patent Application Laid-Open No. 7-187033, the auxiliary member guides the offset collision load from the left and right ends of the bumper to the side members. Is bent and the side stays buckle, and the front of the body is greatly crushed, so that the buckling load cannot be transmitted to the energy absorbing area set behind the side members. I will.

[0010] Therefore, even in the case of this prior art, the buckling deformation of the side member can be hindered against a collision when the offset load is large, so that the collision energy cannot be efficiently absorbed and the occupant receives the collision energy. It is difficult to sufficiently reduce the impact. An object of the present invention is to provide a front structure of a vehicle body capable of sufficiently absorbing collision energy and sufficiently reducing an impact received by an occupant to protect the occupant in an offset collision of the vehicle in a wide speed range. It is in.

[0011]

In order to achieve the above-mentioned object, a first aspect of the present invention is to provide left and right side members arranged on both left and right sides of a vehicle, and a position located a predetermined distance behind a front end of the left and right side members. A left and right side stays provided so as to extend diagonally forward and outward from the vehicle, and a bumper disposed in the left and right direction of the vehicle extends across the left and right side member front end and the left and right side stay front end. In the front structure of the vehicle body configured to be connected and supported, a cross member is provided between the left and right side stay connecting portions of the left and right side members to buckle the side stay when an offset collision load is applied to the bumper. The strength is set to be larger than the buckling strength of the side member.

Therefore, the cross member is provided between the side stay connecting portions of the left and right side members, and the buckling strength of the side stay is set to be greater than the buckling strength of the side member. When the side stay is applied, the load is transmitted from the side stay to the side member via the side stay connecting portion. At this time, the side stay transmits the offset collision load to the side member without buckling, and the cross member is folded by the side member. Since the bending is suppressed, the vicinity of the side stay connecting portion of the side member and the region behind the side member can be reliably buckled.

[0013]

1 and 2 show a vehicle equipped with a vehicle body front structure according to the present invention. This vehicle 10 is of a type with a frame, and is formed by a frame 11 on which a non-illustrated unsprung member, a power plant, and the like are mounted, and a body 12 connected to an upper side thereof. Here, the frame 11 includes a pair of left and right side members 13 and 14 extending in the vehicle front-rear direction X, and the left and right side members 13 and 1.
4 and a front end cross member 15 behind the bumper and a plurality of cross members (not shown) behind the front end cross member 15. Further, on the front end sides of the left and right side members 13 and 14, a side stay mounting position C is set rearward by a distance N from the front ends of the left and right side members, and from the same position, the left and right side stays 17 extending obliquely forward and outward. , 18 are bolted.

As shown in FIG. 2, the left and right side members 13 and 14 extend substantially straight in the front-rear direction X in plan view.
In a side view, as shown in FIG. 1, the front part e1 and the rear part e
2 and a bent step e3 between them. The front part e1 is used for bolting the front part of the body 12 through a rubber mount (not shown) or the like, and forms a mounting part for a front suspension or a power plant. The bent step portion e3 is bent so that the upper end does not interfere with the lower portion of the toe board 26 connected to the deck 27, and the rear portion e2 is bolted to the floor panel 21 or the like via a rubber mount (not shown) or the like.

As shown in FIG. 6, the left and right side members 1
The panels 3 and 14 are formed so that the inner panels 131 and 141 and the outer panels 132 and 142 are overlapped with each other to form a substantially rectangular closed cross-sectional shape. Moreover, as shown in FIGS. 1 and 2, a plurality of reinforcing plates (only front and rear reinforcing plates 19 and 20 are shown) are integrally joined to predetermined portions of the left and right side members 13 and 14, and these joining processes are performed. Thereby, the rigidity of each part, particularly the bending rigidity, is enhanced. Further, here, the front portions e1 of the left and right side members 13, 14 are formed so as to be more easily buckled than the bent step portions e3 and the rear portions e2, and the front portion e1 is located between the front and rear buckling regions D1 across the side stay mounting position C. , D2 (see FIG. 2). Here, the relative sizes and shapes of the closed cross-sectional shapes of the front buckling region D1 and the rear buckling region D2 are adjusted so that they are more easily buckled and deformed than the rear buckling region D2. Thus, it is set so that the impact energy is absorbed at the time of the collision of the vehicle in the front buckling region D1 farthest from the vehicle compartment R, and then in the rear buckling region D2.

The bumper 16 is arranged in the left-right direction Y of the vehicle, and is connected and supported across the front ends of the left and right side members 13, 14 and the front ends of the left and right side stays 17, 18. Further, the bumper 16 has a closed cross-sectional shape in which the front and rear panels 161 and 162 are overlapped as shown in FIG. The outer periphery of the bumper 16 is covered with a bumper pad 163 (see FIG. 7) made of a cushion material and a skin material.
And the bending deformation of the bumper 16 itself can absorb the collision energy. As shown in FIG. 6, a plurality of holes 164 are provided near the left and right ends of the front panel 161.
These holes 164 are formed in the left and right side members 1.
3, 14 and the left and right side stays 17, 18 are used as insertion holes for bolts and nuts used for connection.

That is, as shown in FIGS. 6 and 8, the left side member 13 is welded to the front end of the inner panel 131 with the front piece 20 so as to cover the front end of the closed section formed by both panels. I have. A weld nut 21 and a weld bolt 22 are welded to the rear surface of the forward facing piece 20, and a rear panel 162 of the bumper is fastened and fixed by bolts 23 and nuts 24 screwed to these. The front piece 20 (see FIG. 7) on the right side member 14 is also fastened and fixed to the rear panel 162. As shown in FIGS. 2 and 7, the left and right side stays 17 and 18 are straight brackets having a closed cross-section, and both are formed symmetrically, and the respective stays are a front flange 171, 181 and a rear flange 172, respectively. 182 are formed.

As shown in FIGS. 6 and 10, the front and rear flanges 171 and 172 of the left side stay 17 are formed with mounting surfaces 173 and 174 inclined with respect to the longitudinal direction of the stay. A pair of bolt holes 175 are respectively formed. The front flange 171 has its mounting surface 173 in contact with the rear panel 162 of the bumper (see FIG. 9), and both are fastened and fixed by bolts 25 inserted into bolt holes 175. Rear flange 172
Has its mounting surface 174 in contact with the outer panel 132 of the left side member (see FIG. 6).
It is fastened and fixed by a bolt (not shown) inserted into the connector 75. On the other hand, the right and left side stays 18 (see FIG. 7) also have front and rear flanges 181 and 182 respectively.
2 and bolt 25 on outer panel 142 of right side member
Is tightened and fixed.

As shown in FIG. 2, the rear flanges 172, 182 of the left and right side stays 17, 18 are integrally connected to respective side stay mounting positions C of the left and right side members 13, 14. Here, the left and right outer panels 132, 14
The front reinforcing plate 1 is provided on the back surface of each side stay mounting position C of No. 2.
The weld nuts 28 (only the right nuts are shown in FIG. 7) for screwing the bolts 25 are welded to the inner surface of the front reinforcing plate.

Incidentally, the left and right side stays 17 and 18 as described above have a substantially rectangular closed cross-sectional shape at the main part, and are sufficiently stiffened. Particularly, the buckling strength due to the longitudinal load is reduced. The buckling strength is set to be larger than the buckling strength of the front buckling region D1 and the rear buckling region D2 on the 14 side. This allows
When a load is applied to the rear buckling area D2 from the left and right side stays 17 and 18 via the side stay attachment position C and the buckling progresses at the same, buckling deformation of the left and right side stays 17 and 18 itself is prevented during this time. The rearward bending deformation of the left and right ends of the bumper 16 is prevented, and the offset collision load described later can be reliably guided to the rear buckling region D2.

Vehicle 1 having such a vehicle body front structure
The displacement at the time of collision of 0 will be described. First, a case where the vehicle 10 collides with an oncoming object such as another vehicle will be described. When the vehicle speed is relatively low and the collision energy is relatively low, the load W (see FIG. 2) at the time of a frontal collision is absorbed by the bending deformation of only the bumper 16, or the bumper 16 and the left and right side members 13,
It is absorbed by the buckling deformation of the two front buckling regions D1. When the vehicle speed is relatively high and the collision energy is relatively large, the load W at the time of the collision is a bending deformation of the bumper 16, and the respective front buckling regions D1 and the rear buckling regions D2 of the left and right side members 13, 14 are respectively. It is absorbed by bending deformation.

As described above, in the case of a head-on collision, the load W received by the bumper 16 is applied to both front buckling regions D of the left and right side members 13 and 14.
1 and the rear buckling area D2 are reliably transmitted, and the two parts D1 and D2 are sequentially and reliably buckled according to the magnitude of the collision energy.
Can absorb collision energy. Next, the displacement of the vehicle body when the vehicle 10 makes an offset collision with an oncoming object such as another vehicle by a predetermined amount a will be described with reference to FIGS. Here, as shown in FIG. 11, the oncoming vehicle V is shifted by a predetermined amount a from the center position of the vehicle 10 (indicated by a dashed line).
A case will be described in which an offset collision occurs only to the right.

When the vehicle speed is relatively low and the collision energy is relatively low, the offset collision load W1 at the time of the collision is applied to the right end of the bumper 16 as shown in FIG. However, since the right end transmits the load W1 from the right side stay 18 to the side stay attachment position C of the right side member 14 and is dispersed, the right end of the bumper 16 does not bend, and the bumper 16 faces the right side member 14. Only the bending deformation in the vicinity of the portion is sufficient, or the front buckling region D1 of the right side member 14 buckles in addition to the deformation of the bumper 16, and a relatively small collision energy is absorbed.

When the vehicle speed is relatively high and the collision energy is relatively large, the offset collision load W1 at the time of the collision is smaller than the bumper 16 by the right side member 14 as shown in FIGS.
Is transmitted directly from the front end of the right side member 18 to the side stay mounting position C of the right side member 14. At this time,
First, the portion of the bumper 16 facing the right side member 14 is bent and deformed, the front buckling region D1 of the right side member 14 buckles, and then the rear buckling region D2 starts buckling, and the cross member 15 The right end (the side stay attachment position C of the right side member 14) is pivotally displaced backward M about the left end (the side stay attachment position C of the left side member 13) to bend the rear buckling area D2. Bend without deforming.
In the case where the collision energy is particularly large, the front end side of the bent step portion e3 is bent with the buckling deformation of the rear buckling region D2 as shown in FIG. 5, and the right side member 14 moves the front portion e1 upward. Although it is displaced, the deformation of the cabin R is minimized.

As described above, the offset collision load W1 received by the bumper 16 is directly transmitted from the front end of the right side member 14 to the front buckling region D1 via the right side stay 18 which is strengthened and does not buckle or bend. Stay mounting position C
The cross member 15 further prevents the right side member 14 from being bent and deformed, and the rear buckling region D2 is reliably buckled, so that the collision energy can be reliably absorbed. In the above description, the vehicle 10 is a type with a frame in which the frame 11 and the body 12 are independently formed. However, the present invention is applied to a frameless type vehicle having a part where the frame and the body are mutually shared parts. May be applied.

In the case of this frameless type vehicle, a front part e1 and a bent step part e3 shown in FIG. 1 are usually provided, and a pair of left and right front side members is provided. Since it is often formed, the front structure of the vehicle body of the present invention can be applied almost similarly to the vehicle 10 of FIG. 1, and the same operation and effect can be obtained.

[0027]

As described above, according to the first aspect of the present invention, when an offset collision load is applied to a bumper, the offset collision load is transmitted to the side member via the side stay connecting portion without buckling of the side stay. Since the cross member suppresses the bending deformation of the side member, a region behind the side stay connecting portion of the side member buckles reliably. In this manner, the offset collision load applied to the bumper by the side stays and the cross member can be efficiently guided to the rear region near the side stay connection portion of the side member, so that the region is buckled and the collision energy is reduced. It is possible to reliably absorb, reduce the impact received by the occupant, and protect the occupant.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a cutaway front view of a vehicle employing a vehicle body front structure of the present invention.

FIG. 2 is a schematic front view of a notch front view of the vehicle of FIG. 1;

FIG. 3 is a schematic front view of a notch in a plan view at the time of an offset collision of the vehicle of FIG. 1 at a relatively low speed.

FIG. 4 is a schematic front view of a notch in a plan view at the time of an offset collision of the vehicle of FIG. 1 at a relatively high speed.

FIG. 5 is a schematic front view of a cutaway front view of the vehicle shown in FIG. 4;

FIG. 6 is an exploded perspective view of a front portion of a frame of the vehicle in FIG. 1;

FIG. 7 is an enlarged cutaway plan view of a right front portion of the frame of the vehicle in FIG. 1;

FIG. 8 is an enlarged sectional view taken along line AA of FIG. 6;

FIG. 9 is an enlarged sectional view taken along line BB of FIG. 6;

FIG. 10 is an enlarged perspective view of a left side stay in FIG. 6;

FIG. 11 is a schematic front view of a notched front portion of a conventional front structure of a vehicle body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vehicle 11 Frame 12 Body 13 Left side member 14 Right side member 17 Left side stay 18 Right side stay 16 Bumper 15 Cross member e1 Front part e2 Rear part e3 Bending step C Right and left side stay connection part N Predetermined distance X Front and rear direction Y Left / right direction W1 Offset collision load

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-8-258745 (JP, A) JP-A-57-194135 (JP, A) JP-A-7-187003 (JP, A) 58466 (JP, U) JP-A 3-72056 (JP, U) JP-A 63-176877 (JP, U) JP-B 52-33849 (JP, B2) (58) Field surveyed (Int. ⁷ , DB name) B62D 25/20 B62D 25/08 B60R 19/24

Claims (1)

(57) [Claims] 1. A vehicle comprising: left and right side members disposed on both left and right sides of a vehicle; and left and right side stays provided to extend obliquely forward and outward from a position behind a front end of the left and right side members by a predetermined distance. In the front structure of a vehicle body, a bumper arranged in the left-right direction of the vehicle is connected and supported across the front end of the left and right side members and the front end of the left and right side stays. A vehicle body characterized in that a cross member is provided between left and right side stay connecting portions, and a buckling strength of the side stay when an offset collision load is applied to the bumper is set to be larger than a buckling strength of the side member. Front structure.