JP4293029B2 - Body front structure - Google Patents

Description

  The present invention relates to a vehicle body front part structure, and more particularly to a vehicle body front part structure that constitutes a vehicle body front side lower part of a vehicle body such as an automobile.

2. Description of the Related Art Conventionally, in a vehicle body front structure that constitutes a vehicle body front side lower part of a vehicle body such as an automobile, first cross members and left and right side rails disposed along the vehicle body longitudinal direction at both ends in the vehicle width direction of the vehicle body The second cross member is installed with a space in the front-rear direction, and the first cross member and the second cross member are connected by braces, so that the load from the front of the vehicle body is second from the first cross member. The structure which transmits to the cross member of this is known (for example, refer nonpatent literature 1). The front side frame is provided with three mounting brackets extending in a downward projecting manner, and suspension cross members are attached to the first and second mounting brackets on the left and right sides of the suspension cross member in the vehicle width direction. A configuration in which a cross member main body is provided so as to correspond to a second mounting bracket is known (see, for example, Patent Document 1).
Toyota Technical Disclosure Collection 13608 (issued on June 28, 2002) JP-A-5-310146

  However, in the vehicle body front structure as in Patent Document 1, the brace is fastened to the second cross member when a load from the front of the vehicle body is transmitted from the first cross member to the second cross member via the brace. The load is transmitted from the brace to the second cross member only through the bolts. As a result, the load concentrates on the bolt fastening portion in the brace and breaks. In order to prevent damage to the bolt fastening part in this brace and improve load transmission efficiency, it is necessary to separately reinforce the bolt fastening part in the brace and reinforce it, which increases the weight. To do.

  In view of the above facts, an object of the present invention is to provide a vehicle body front structure that can improve load transmission efficiency without increasing the weight.

The vehicle body rear part structure of the present invention according to claim 1 includes left and right side rails disposed along the vehicle body longitudinal direction at both ends in the vehicle width direction,
A first cross member constructed on the left and right side rails;
A second cross member erected on the left and right side rails behind the first cross member;
A brace extending in the longitudinal direction of the vehicle body for connecting the first cross member and the second cross member, and having a rear end fastened to a mounting surface of the second cross member by a bolt ;
When the front end approaches the rear side of the brace on the mounting surface of the second cross member and is fastened by a bolt, and a load of a predetermined value or more acts on the brace from the front side of the vehicle body toward the rear side of the vehicle body And a drive unit support member in contact with the brace,
It is characterized by having.

Accordingly, the load from the front of the vehicle body is changed from the first cross member installed on the left and right side rails disposed along the vehicle longitudinal direction at both ends in the vehicle width direction to the left and right behind the first cross member. The first cross member and the second cross member that extend in the longitudinal direction of the vehicle body are connected to the second cross member that is installed on the side rail, and the rear end is a bolt on the mounting surface of the second cross member. It can be transmitted through the brace fastened by. At this time, if a load of a predetermined value or more is applied to the brace from the front side of the vehicle body to the rear side of the vehicle body, the brace approaches the rear side of the brace on the mounting surface of the second cross member. The contact of the drive unit support member fastened by the bolt and the deformation of the fastening portion of the brace is suppressed. As a result, the load from the brace can be transmitted from the rear end portion of the brace to the mounting surface of the second cross member via the bolt, and the second cross member can also be transmitted from the fastening portion of the drive unit support member via the bolt. Can be transmitted to the mounting surface. For this reason, it can prevent that a load concentrates on the fastening part with the attachment surface of the 2nd cross member in a brace, and breaks, and can improve load transmission efficiency. Therefore, it is not necessary to reinforce the fastening portion by separately providing a fastening member at the fastening portion with the mounting surface of the second cross member in the brace, so that the load transmission efficiency can be improved without increasing the weight.

  According to a second aspect of the present invention, in the vehicle body front portion structure according to the first aspect, the drive unit support member is a front differential support.

Accordingly, the load from the front of the vehicle body is changed from the first cross member installed on the left and right side rails disposed along the vehicle longitudinal direction at both ends in the vehicle width direction to the left and right behind the first cross member. The first cross member and the second cross member that extend in the longitudinal direction of the vehicle body are connected to the second cross member that is installed on the side rail, and the rear end is a bolt on the mounting surface of the second cross member. It can be transmitted through the brace fastened by. At this time, if a load of a predetermined value or more is applied to the brace from the front side of the vehicle body to the rear side of the vehicle body, the brace approaches the rear side of the brace on the mounting surface of the second cross member. Therefore, the deformation of the fastening portion of the brace is suppressed by contacting the front differential support fastened by the bolt . As a result, the load from the brace, it is possible transfer to the mounting surface of the second cross member via a bolt from the rear end of the brace, the second cross member also through a bolt from the fastening portion of the front differential support Can communicate. For this reason, it can prevent that a load concentrates on the fastening part with the attachment surface of the 2nd cross member in a brace, and breaks, and can improve load transmission efficiency. Therefore, it is not necessary to reinforce the fastening portion by separately providing a fastening member at the fastening portion with the mounting surface of the second cross member in the brace, so that the load transmission efficiency can be improved without increasing the weight.

The vehicle body front structure according to the first aspect of the present invention includes left and right side rails that are disposed at both ends in the vehicle width direction along the vehicle body longitudinal direction, and a first cross member that is installed on the left and right side rails. The second cross member that is installed on the left and right side rails behind the first cross member, and the first cross member and the second cross member that extend in the longitudinal direction of the vehicle body are connected, and the rear end portion The brace fastened to the mounting surface of the second cross member by a bolt, and the front end of the brace fastened to the rear side of the body of the brace on the mounting surface of the second cross member is fastened by the bolt. When a load of a predetermined value or more is applied toward the rear side of the vehicle body, it has a drive unit support member that comes into contact with the brace, so that the load transmission efficiency can be improved without increasing the weight. Has an excellent effect say.

  In the vehicle body front structure according to claim 1, the drive unit support member is a front differential support, so that the load transmission efficiency can be improved without increasing the weight. Have.

  An embodiment of a vehicle body front structure according to the present invention will be described with reference to FIGS.

  In addition, arrow FR in the figure has shown the vehicle body front direction.

  As shown in FIG. 1, a pair of left and right side rails 12 disposed along the longitudinal direction of the vehicle body are disposed at the lower part of both ends in the vehicle width direction of the front body 10A of the vehicle body 10. A front bumper reinforcement 14 is disposed at the front end 12 </ b> A of the side rail 12.

  A front cross member 16 as a first cross member is disposed along the vehicle width direction on the rear side of the vehicle body of the front bumper reinforcement 14. The front cross member 16 is installed on the left and right side rails 12. Yes.

  A front suspension member 18 as a second cross member is disposed along the vehicle width direction at a predetermined interval on the rear side of the vehicle body of the front cross member 16. The front suspension member 18 is arranged on the left and right side rails 12. It is built in.

  A rear suspension member 20 is disposed along the vehicle width direction at a predetermined interval on the vehicle body rear side of the front suspension member 18, and the rear suspension member 20 is installed on the left and right side rails 12. .

  Suspension arms 22 are attached to both end portions 18A in the vehicle width direction of the front suspension member 18 and both end portions 20A in the vehicle width direction of the rear suspension member 20, respectively.

  A cooling system component 26 such as an air conditioner condenser or a radiator is disposed above the front cross member 16.

  A pair of left and right braces 30 are disposed between the front cross member 16 and the front suspension member 18 along the longitudinal direction of the vehicle body, and the front end portion 30A of each brace 30 is on the lower surface 16B of the front cross member 16. It is fixed to a part spaced apart from the center part in the vehicle width direction by a predetermined distance.

  As shown in FIG. 2, the rear end 30B of the brace 30 is trapezoidally wide from the front side of the vehicle body to the rear side of the vehicle body in plan view, and the rear end portion 30B is circular from the rear side of the vehicle body. An arcuate notch 32 is formed.

  Further, both end portions in the vehicle width direction of the rear end portion 30B of the brace 30 are fastening portions 30C, and each brace 30 is fastened to a lower surface 18B as a mounting surface of the front suspension member 18 by a bolt 34 in the fastening portion 30C. ing.

  As shown in FIG. 1, between the front suspension member 18 and the rear suspension member 20, a pair of left and right front differential supports 40 as drive unit support members are disposed along the longitudinal direction of the vehicle body. A rear end portion 40 </ b> A of the differential support 40 is fixed to the front differential 21.

  As shown in FIG. 2, the front end portion 40B of the front differential support 40 is circular in plan view, and the front end portion 40B of the front differential support 40 is the rear end of the brace 30 on the lower surface 18B of the front suspension member 18. The part 30B is fixed close to the rear side of the vehicle body. For this reason, when a load of a predetermined value or more is applied to the brace 30 from the front side of the vehicle body toward the rear side of the vehicle body, the brace 30 moves backward (in the direction of arrow A in FIG. 2). As indicated by a chain line, the notch 32 of the rear end portion 30B of the brace 30 and the front portion of the front end portion 40B of the front differential support 40 are brought into contact with each other so that deformation of the fastening portion 30C of the brace 30 is suppressed.

  Further, the central portion of the front end portion 40B of the front differential support 40 is a fastening portion 40C, and the front differential support 40 is fastened to the lower surface 18B of the front suspension member 18 by a bolt 44 at the fastening portion 40C.

  Therefore, when a load of a predetermined value or more is applied to the brace 30 from the front side of the vehicle body to the rear side of the vehicle body, the load from the brace 30 is applied to the lower end 18B of the front suspension member 18 from the rear end portion 30B of the brace 30. It can be transmitted to the front suspension member 18 via the bolt 34 to be fastened, and can also be transmitted to the front suspension member 18 via the bolt 44 fastened to the lower surface 18B of the front suspension member 18 by the fastening portion 40C of the front differential support 40. It has become.

  Next, the operation of this embodiment will be described.

  In the present embodiment, as shown in FIG. 3, the load when the vehicle body 10 has a front collision (FIG. 3 shows a state in which the vehicle body 10 has a front collision) is applied to both ends of the vehicle body 10 in the vehicle width direction. From the front cross member 16 installed on the left and right side rails 12 arranged along the front-rear direction to the front suspension member 18 installed on the left and right side rails 12 behind the front cross member 16 in the vehicle front-rear direction. The front cross member 16 and the front suspension member 18 are connected to each other, and the rear end 30B can be transmitted via the brace 30 fastened to the lower surface 18B of the front suspension member 18.

  At this time, when loads F1 and F2 of a predetermined value or more are applied to the brace 30 from the front side of the vehicle body toward the rear side of the vehicle body, the brace 30 moves rearward (in the direction of arrow A in FIG. 2). As shown by a two-dot chain line, the notch 32 of the rear end portion 30B of the brace 30 and the front portion of the front end portion 40B of the front differential support 40 come into contact with each other, and deformation of the fastening portion 30C of the brace 30 is suppressed.

  As a result, the load from the brace 30 can be transmitted to the front suspension member 18 via the bolt 34 that fastens the rear end portion 30B of the brace 30 to the lower surface 18B of the front suspension member 18, and the fastening portion 40C of the front differential support 40 is also provided. Can be transmitted to the front suspension member 18 via the bolts 44 fastened to the lower surface 18B of the front suspension member 18, and the load transmission efficiency can be improved. For this reason, it can prevent that a load concentrates on the fastening part of the volt | bolt 34 in the rear-end part 30B of the brace 30, and breaks.

  Therefore, in this embodiment, it is not necessary to provide a separate reinforcing member at the fastening portion of the bolt 34 at the rear end portion 30B of the brace 30 to reinforce the fastening portion, so that the load transmission efficiency is improved without increasing the weight. it can.

  Furthermore, in this embodiment, the load from the brace 30 can be transmitted to the front differential 21 via the front differential support 40.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art. For example, in the above embodiment, the pair of left and right front differential supports 40 as the drive unit support members are used. However, instead of the pair of left and right front differential supports 40, other drive unit support members may be used.

It is the top view seen from the vehicle body lower part which shows the vehicle body front part structure which concerns on one Embodiment of this invention. It is the enlarged plan view seen from the vehicle body lower part which shows the principal part of the vehicle body front part structure concerning one Embodiment of this invention. It is the top view seen from the vehicle body downward which shows the deformation | transformation state of the vehicle body front part structure which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Car body 10A Front body 12 Side rail 16 Front cross member (1st cross member)
18 Front suspension member (second cross member)
18B Bottom surface of front suspension member (mounting surface)
30 Brace 30A Front end of brace 30B Rear end of brace 30C Fastening part of brace 32 Notch of brace 34 Bolt 40 Front differential support (drive unit support member)
40A Rear end portion of front differential support 40B Front end portion of front differential support 40C Fastening portion of front differential support 44 Bolt

Claims (2)

Left and right side rails arranged along the vehicle longitudinal direction at both ends in the vehicle width direction;
A first cross member constructed on the left and right side rails;
A second cross member erected on the left and right side rails behind the first cross member;
A brace extending in the longitudinal direction of the vehicle body for connecting the first cross member and the second cross member, and having a rear end fastened to a mounting surface of the second cross member by a bolt ;
When the front end approaches the rear side of the brace on the mounting surface of the second cross member and is fastened by a bolt, and a load of a predetermined value or more acts on the brace from the front side of the vehicle body toward the rear side of the vehicle body And a drive unit support member in contact with the brace,
The vehicle body front part structure characterized by having.   The vehicle body front structure according to claim 1, wherein the drive unit support member is a front differential support.

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