Front vehicle-body structure of vehicle

1. A front vehicle-body structure of a vehicle, comprising:

a pair of front side frames extending in a longitudinal direction at both sides of a front portion of the vehicle;

a pair of sub frames provided below the front side frames and supporting a front suspension;

a pair of attachment portions attached to front ends of the pair of sub frames and projecting forward;

a heat exchanger provided between the pair of front side frames, the heat exchanger including a radiator and a shroud panel covering the radiator;

a stiffener extending in a vehicle width direction and projecting forward, the stiffener being positioned below the shroud panel and the pair of attachment portions, the stiffener comprising a main-body portion positioned at a center in the vehicle width direction, a main-body rear portion positioned behind the main-body portion, and both-side portions positioned on both sides of the main-body portion,

wherein said sub frames and said attachment portions are provided on the outside of said heat exchanger in the vehicle width direction, and

said stiffener is attached to a lower face of said shroud panel and respective lower faces of said pair of attachment portions via attaching members such that an upper face of the main-body rear portion thereof contacts the lower face of the shroud panel and respective upper faces of the both-side portions thereof contact the respective lower faces of the pair of attachment portions, whereby the stiffener is separated downward off the lower face of said shroud panel and the attachment portions by a collision load in a vehicle collision state.

2. The front vehicle-body structure of a vehicle of claim 1 , wherein said attachment portions attached to the front ends of the sub frames are comprised of crush cans, a bumper reinforcement is provided at front portions of said crush cans to extend in the vehicle width direction, and said stiffener projects forward to a position near a back face of a bumper face provided in front of the bumper reinforcement.

3. The front vehicle-body structure of a vehicle of claim 1 , wherein said stiffener has a contact face to contact a front face of said shroud panel in a vehicle frontal collision, which is formed in a step shape between the main-body portion and the main-body rear portion.

4. The front vehicle-body structure of a vehicle of claim 1 , wherein said stiffener has a notch portion with a rearward open, through which an intake duct to supply air for combustion of an engine passes, to avoid interference with the intake duct, which is formed at a connection potion between the both-side portion and the main-body portion.

5. The front vehicle-body structure of a vehicle of claim 1 , wherein each of said both-side portions of the stiffener comprises an extension portion extending outward beyond said shroud panel in the vehicle width direction, and the extension portion has a support portion to support a bumper face.

6. The front vehicle-body structure of a vehicle of claim 1 , wherein each of said both-side portions of the stiffener comprises an extension portion which extends outward in the vehicle width direction from said main-body portion, and a rear portion which projects rearward from said extension portion and has an upwardly open recess, at least part of each of said attachment portions being positioned in the recess of the rear portion such that a bottom face of said recess contacts the lower face of said at least part of the attachment portion, thereby attaching the both-side portions of the stiffener to the lower faces of the attachment portions via said attaching member.

7. The front vehicle-body structure of a vehicle of claim 1 , wherein said attaching members are fastening members which are applied from below the stiffener.