JP3533011B2 - Vehicle body front frame 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 vehicle body front frame structure of a vehicle.

[0002]

2. Description of the Related Art Generally, a vehicle body front portion, that is, a frame structure of an engine room, connects left and right basic frames longitudinally passing along a side wall of the engine room with front parts of the left and right basic frames. It is usually composed of a radiator frame lower, and a ladder type subframe having a power unit or a front suspension attached thereto is attached to the above left and right basic frames conventionally (for example, Japanese Laid-Open Patent Publication No. 3-25082 gazette).

[0003]

Among frontal collisions of vehicles, oblique collisions and offset collisions, which are considered to have a high degree of injury, are more severe than full-lap collisions because the collision load is concentrated on one side of the vehicle. It is a collision form.

From the viewpoint of absorption, transmission, dispersion, etc. of collision energy at the time of a frontal collision, it is ideal to pass the above left and right basic frames straight forward and backward, but due to restrictions such as inside and outside the engine room, the frames are made straight. It is usually difficult to pass through, and it is customary that some bending is inevitable in practice.

However, at the time of a frontal collision, the slightly bent portions of the left and right basic frames serve as a crush zone to locally crush, so that it is difficult to effectively absorb, transmit, and disperse the collision energy. There is a problem that it is very difficult to cope with both an oblique collision in which the collision load concentrates on one side with an angle and an offset collision in which the collision load concentrates straight on the front of one side in a well-balanced manner.

The present invention is intended to solve the above conventional problems.

[0007]

According to the present invention, as described above, the left and right basic frames are formed with the bent portions serving as the crush zones, and the front portion is provided on the lower surface of the basic frame.
The left and right vertical frames of the left and right vertical frames that are attached and fixed by the joining and fixing parts of the rear part, the front side horizontal frame having the radiator support part and the rear side horizontal frame having the engine mount part Characterized by forming a restraint / fixing portion that is joined and fixed to the crush zone of the frame to restrain crush near the crush zone
Is. In addition, front and rear crush zones which are more likely to buckle than a restraining and fixing portion with respect to a frontal collision load are formed in a predetermined range portion before and after the restraining and fixing portion.

[0008]

As described above, by using the sub-frame and fixing the restraint fixing portion formed on the vertical frame of the sub-frame to the crushing zone of the basic frame, the crushing near the crushing zone at the time of a frontal collision is prevented. Restraint prevents a sharp drop in drag due to crushing of the crush zone, and the front and rear crush zones formed in front of and behind the restraint / fixing part can be stably buckled, thereby sustaining collision energy absorption. As a result, collision energy is effectively absorbed. Furthermore, since the sub-frame assembled in a well shape is fixed to the basic frame, it becomes possible to absorb, transmit, and disperse the collision energy in a well-balanced manner even in the case of a frontal diagonal collision or a frontal offset collision.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numerals 1 and 1 denote left and right basic frames that vertically pass along the front side of the vehicle body, that is, the left and right side walls of the engine room. The basic frame 1 is box-shaped as conventionally known. The left and right side frames 4 have a cross-section, and the rear end is abutted and fixed to the toe board 2 and curved downward along the toe board 2, and the rear end is joined and fixed to the lower surface of the floor panel 3 and vertically extends. , 4 is connected to the front end.

Reference numeral 5 denotes a sub-frame. The sub-frame 5 has left and right vertical frames 51, 51 mounted and fixed to the lower surface of the basic frame 1, and the vertical frames 51, 51.
Is composed of a front side horizontal frame 52 and a rear side horizontal frame 53 that connect the front side and the rear side of the vertical frame 51,
The front side horizontal frame 52 and the rear side horizontal frame 53 each have a box-shaped cross section, and the front side horizontal frame 52 is provided with a radiator support portion 52a for supporting a radiator and a condenser (both not shown). An engine mount portion 53a that supports a power unit (not shown) is formed.

The basic frame 1 is, as described above,
From the viewpoint of collision energy absorption, transmission, and dispersion at the time of a frontal collision, it is ideal to pass it straight forward and backward, but due to restrictions inside and outside the engine room, some bending is unavoidable, and the slight bending part It becomes a crush zone 1a at the time of a frontal collision and crushes locally.

Therefore, by utilizing the sub-frame 5 fixed to the lower surface portion of the basic frame 1, the sub-frame 5 increases the reaction force against the collision load of the crush zone 1a of the basic frame 1 so that a frontal collision occurs. Crush zone 1
A sudden drop of the drag force due to the crushing of a is prevented, and a stable buckling mode is provided on the front side and the rear side of the crushing zone 1a, so that a continuous collision energy absorption waveform can be obtained.

That is, the left and right vertical frames 51 of the sub-frame 5 are formed with joint fixing portions 51b and 51c to the basic frame 1 at the front and rear ends thereof, and the crush zone 1a of the basic frame 1 is formed. The restraint fixing portion 51a is set at an intermediate position corresponding to the restraint fixing portion 51a and the front and rear predetermined range portions of the restraint fixing portion 51a are compared with the restraint fixing portion 51a and the joining fixing portions 51b and 51c with respect to the collision load. The front crushing zone 51d and the rear crushing zone 51e, which are relatively easily crushed, are positively formed. As a specific configuration example of the crush zones 51d and 51e on the front side and the rear side,
As in the illustrated embodiment, the restraint fixing portion 51a and the joining fixing portion 5
The simplest means is to make the cross-sectional area partially smaller than 1b and 51c, but it is also known from the prior art that a plurality of beads in the direction orthogonal to the longitudinal direction of the vertical frame are formed to make it easier to collapse. Any crushing zone forming means can be adopted.

Then, the left and right vertical frames 51 of the sub-frame 5 constructed as described above are abutted against the lower surface of the basic frame 1, and the lower surface of the basic frame 1 and the restraint fixing portions 51a and the joining fixing portions 51b and 51c are provided. The joint portion is fixed with a fixing member such as a bolt, and the basic frame 1 and the sub frame 5
And constitute the vehicle body front frame.

In the vehicle body front frame thus constructed, the crushing in the vicinity of the crushing zone 1a of the basic frame 1 against the collision load at the time of a frontal collision is caused by the restraint fixing portion 51a formed in the vertical frame 51 of the subframe 5. It is restrained by fixing, the drag force of the crush zone 1a is improved, the rapid drop of the drag force due to the crush of the crush zone 1a is mitigated, and the predetermined range on the front side and the rear side of the crush zone 1a is the vertical frame 51. The front side crushing zone 51d and the rear side crushing zone 51e relatively facilitate buckling deformation, and the front side and the rear side of the crushing zone 1a are sequentially buckled twice, so that stable and stable absorption of collision energy can be achieved. Done.

FIG. 2 is a diagram for explaining a collision energy absorption characteristic at the time of a frontal collision. FIG. 2A shows a case where only the basic frame 1 is used, and after the first peak of the drag force at the initial collision,
The state in which the drag force suddenly drops due to the crushing of the crushing zone 1a is shown. 2B shows a case where the vicinity of the crushing zone 1a of the basic frame 1 is restrained by the restraint fixing portion 51a formed on the vertical frame 51 of the sub-frame 5, and the first drag force in the initial stage of collision is shown. The second peak is formed after the peak of No. 2 by the crushing zone 1a being restrained by the restraint fixing portion 51a, and the impact energy absorption effect in the shaded area is improved as compared with the conventional one shown in FIG. It is stable. FIG. 2C shows a case where a restraint fixing portion 51a that restrains the crush zone 1a of the basic frame 1 is formed in the vertical frame 51 of the sub-frame 5, and crush zones 51d and 51e are formed before and after the restraint fixing portion 51a. And in this case, after the first peak of drag at the beginning of the collision,
A second peak is formed by restraining the crushing zone 1a portion by the restraint fixing portion 51a, and a drag force as in stable buckling before and after the crushing zone 1a due to the front and rear crushing zones 51d and 51e. The depressions (valleys) are filled, the drag can be maintained as in the shaded area, and the collision energy can be effectively absorbed.

Further, by fixing the sub-frame 5 assembled in a well shape to the lower side of the basic frame 1, it is possible to absorb, transmit and disperse the collision energy in a well-balanced manner even at an oblique collision and an offset collision. Is possible.

The crushing zone 1a of the basic frame 1 is 2
If there are more or more places, the restraint / fixing portions 51a for restraining the crush of the crush zone 1a are also provided at two or more places.

[0020]

As described above, according to the present invention, the left and right vertical frames joined to and fixed to the lower surface portions of the left and right basic frames vertically extending along the side wall of the front portion of the vehicle body, and the left and right vertical frames are provided. A subframe composed of a front side horizontal frame and a rear side horizontal frame connected to each other at the front part and the rear part is used to increase the drag force of the bending part of the basic frame at the time of a frontal collision, and By setting stable buckling parts in the front and rear of the vehicle, it is possible to maintain the collision energy absorption at the time of frontal collision, and also to absorb and transmit the collision energy in a well-balanced manner even for frontal oblique collisions and frontal offset collisions. ， Because it can be dispersed, it is extremely effective in vehicle safety measures.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which (A) is a plan view, (B) is an exploded perspective view, (C) is a front view of a portion X of (A), and (D) is (A). FIG.

FIG. 2 is a diagram illustrating a collision energy absorption characteristic at the time of a frontal collision, where (A) is a basic frame only, and (B) is a diagram.
When the crush is restrained in the sub-frame near the bent portion (crush zone) in the sub-frame, (C) is the crush in the sub-frame restrained near the bent portion and the crush zones are set before and after that. Each case is shown.

[Explanation of symbols]

1 basic frame 1a Crush zone 2 Toe board 3 floor panels 4 side frames 5 subframes 51 vertical frame 51a Restraint fixing part 51b Joint fixing part 51c Joint fixing part 51d Front crushing zone 51e Rear crushing zone 52 Front horizontal frame 52a Radiator support section 53 Rear horizontal frame 53a Engine mount part

Claims (3)

(57) [Claims] 1. A left and right basic frame having a box-shaped cross section that extends longitudinally along a side wall of a front portion of a vehicle body, in which bent portions which are crush zones at the time of a frontal collision are formed, and a lower surface portion of the basic frame is formed. Mounted and fixed at the front and rear joint fixing parts
The left and right vertical frames of the sub-frame consisting of the left and right vertical frames, the front side horizontal frame having the radiator support section, and the rear side horizontal frame having the engine mount section are joined and fixed to the crush zone of the basic frame. A vehicle body front frame structure, characterized in that a restraint / fixing portion that restrains crushing in the vicinity is formed. 2. The vehicle body front frame structure according to claim 1, wherein the restraint fixing portions are provided on the front and rear sides of the restraint fixing portions of the left and right vertical frames of the sub-frame against a collision load in a frontal collision. A front body frame structure for a vehicle, characterized in that front and rear crush zones are formed, which are more likely to buckle than in. 3. The vehicle body front frame structure according to claim 2, wherein the vertical frame having a box-shaped cross section has a small cross-sectional area only in a predetermined range portion on the front side and the rear side of the restraint fixing portion. A front body frame structure for a vehicle, characterized by comprising front and rear crush zones.