JP2022030063A - Front body structure of vehicle - Google Patents

Abstract

To provide a front body structure of a vehicle making it possible to attain a light weight and upgraded impact energy absorption performance.SOLUTION: A front body structure includes a pair of left and right apron reinforcements 30 and a pair of left and right hinge pillars 20. The hinge pillar 20 includes a pillar outer member 21 and a pillar inner member 22 that cooperates with the pillar outer member 21 in forming a closed section. The pillar inner member 22 includes a body 22a and a distal member 23 extending forward. The distal member 23 includes a junction part 23b joined to the rear part of a reinforcement outer member 31, a fragile part 23e formed at a position near a coupler part 23c to be coupled to the body 22a, and a projection 23d formed to project inward in a vehicle width direction between the junction part 23b and fragile part 23e. The buckling strengths of the fragile part 23e and projection 23d are set lower than the bond strength of the junction part 23b.SELECTED DRAWING: Figure 14

Description

The present invention relates to a front body structure of a vehicle having a pair of left and right hinge pillars connected to the rear ends of a pair of left and right apron reinforcements extending in the front-rear direction of the vehicle body.

Conventionally, a pair of left and right apron reinforcements (hereinafter abbreviated as apron rain) extending in the front-rear direction of the vehicle body and a pair of left and right hinge pillars connected to the rear ends of these pairs of apron rains are provided. The front body structure of the vehicle is known.
In addition, in the case of a so-called small overlap collision, where an obstacle collides with the outer part in the vehicle width direction (overlap area is 25% or less) of the front side frame represented by the SORB (Small Overlap Rigid Barrier) test, the apron rain It is also known that the occupant space can be safely secured by absorbing impact energy by inwardly bending and deforming the vehicle inward in the vehicle width direction.

For example, in the front vehicle body structure of the vehicle of Patent Document 1, a pair of left and right apron members (apron rain) extending in the front-rear direction of the vehicle body and forming a closed cross section, and a pair of apron members at the rear ends thereof, respectively. A pair of left and right hinge pillars that are connected, a front rain provided on the outside in the vehicle width direction inside the closed cross section, and an apron member and a hinge pillar provided at a position that overlaps with the front rain on the outside of the closed cross section in a side view. It is equipped with a rear rain connected to the portion, and the front rain and the rear rain are joined via an apron member.

Normally, the apron rain is formed in a substantially U-shape in cross section, the outer portion in the vehicle width direction is welded to the hinge pillar outer member, and the inner portion in the vehicle width direction is welded to the hinge pillar inner member. The hinge pillar inner member is a high-rigidity panel material such as a high-strength steel plate in which a main body portion forming a closed cross section and a tip portion joined to the rear portion of the apron rain are integrally formed.
At the time of a small overlap collision, a shear stress in the shearing direction mainly acts on the joint portion between the rear portion and the tip portion of the apron rain, and finally the joint portion between the two is fractured and separated.
Therefore, the impact energy absorption performance at the time of a small overlap collision is ensured by increasing the plate thickness of the apron rain and adding a reinforcing member without using a hinge pillar.

Japanese Unexamined Patent Publication No. 2018-1358080

During a small overlap collision, the stress applied to the apron rain breaks the joint between the apron rain and the hinge pillar inner member before being transmitted to the hinge pillar inner member.
That is, since the collision load input to the apron rain is not transmitted to the hinge pillar inner member, the buckling strength of the hinge pillar inner member cannot contribute to the impact energy absorption. By transmitting the stress input to the apron rain to the hinge pillar inner member, the buckling strength of the hinge pillar inner member can be used for impact energy absorption, and as a result, the weight of the vehicle body can be reduced. However, no concrete proposal has been made at this time.

An object of the present invention is to provide a front body structure of a vehicle that can achieve both weight reduction and improvement of impact energy absorption performance.

The front body structure of the vehicle according to claim 1 includes a pair of left and right apron reinforcements extending in the front-rear direction of the vehicle body and a pair of left and right hinge pillars connected to the rear ends of the pair of apron reinforcements. In the front body structure of the vehicle provided with the above, the hinge pillar forms a closed cross section extending vertically in cooperation with the hinge pillar outer member arranged outside in the vehicle width direction and the hinge pillar outer member. The hinge pillar inner member has a main body portion having a surface orthogonal to the vehicle width direction, and a tip portion extending forward from the main body portion at a position substantially the same height as the apron reinforcement. The tip of the apron reinforcement is joined to the rear part of the apron reinforcement, the fragile part formed in the vicinity of the connection part with the main body part, and the vehicle between the joint part and the fragile part. It has a protruding portion formed so as to protrude inward in the width direction, and is characterized in that the buckling strength of the fragile portion and the protruding portion is set lower than the joining strength of the joining portion.

In the front body structure of the vehicle, the hinge pillars include a hinge pillar outer member arranged outside in the vehicle width direction and a hinge pillar inner member that cooperates with the hinge pillar outer member to form a closed cross section extending vertically. The hinge pillar inner member is provided with a main body portion having a surface orthogonal to the vehicle width direction and a tip portion extending forward from the main body portion at a position substantially the same as the apron reinforcement. , The hinge pillar inner member can be formed by the main body portion and the tip portion joined to the main body portion.
The tip portion is joined to the rear portion of the apron reinforcement, the fragile portion formed near the connecting portion with the main body portion, and the vehicle width direction between the joint portion and the fragile portion. Since it has a protruding portion formed so as to protrude inward, the posture of the joint portion can be changed by buckling of the fragile portion and the protruding portion. Since the buckling strength of the fragile portion and the protruding portion is set lower than the joint strength of the joint portion, the buckling of the fragile portion and the protruding portion is generated earlier than the breakage of the apron reinforcement and the joint portion. be able to. Moreover, by changing the posture of the joint using the buckling of the fragile part and the protruding part, the stress acting on the joint is converted from the shear stress to the compressive stress, and the apron reinforcement and the hinge pillar inner member It is possible to suppress the breakage of the joint and contribute the buckling strength of the hinge pillar inner member to the impact energy absorption.

The invention of claim 2 is characterized in that, in the invention of claim 1, the fragile portion is composed of a strength difference between the material strength of the main body portion and the material strength of the tip portion.
According to this configuration, a fragile portion can be formed by the difference in material strength between the main body portion and the tip portion.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the fragile portion is configured by making the plate thickness of the tip portion thinner than the plate thickness of the main body portion.
According to this configuration, a fragile portion can be formed by the plate thickness of the main body portion and the plate thickness of the tip portion.

The invention of claim 4 is characterized in that, in the invention of claim 1, the fragile portion is composed of a bead formed on the tip portion. According to this configuration, the fragile portion can be formed by the bead formed at the tip portion.

The invention of claim 5 is characterized in that, in the invention of any one of claims 1 to 4, the protruding portion is composed of a triangular bead having two ridges and an open base. ..
According to this configuration, at the time of a small overlap collision, the fragile portion can be guided to be bent inward in the vehicle width direction by using the deformation of the protruding portion.

According to the front body structure of the vehicle of the present invention, by providing the deformation promoting portion for inducing the deformation of the outer surface portion inside the vehicle body, the apron rain is deformed inward without causing an increase in weight at the time of a small overlap collision. be able to.

It is a right side view of the front body structure of the vehicle which concerns on Example 1. FIG. It is a perspective view which looked at the vehicle body part shown in FIG. 1 from the outside upper side in the vehicle width direction. It is an enlarged view of the main part of FIG. It is a perspective view which looked at the vehicle body part shown in FIG. 3 from the outside upper side in the vehicle width direction. FIG. 3 is a perspective view of the vehicle body portion shown in FIG. 3 as viewed from the lower outside in the vehicle width direction. It is the figure which omitted the apron rain from the body part shown in FIG. FIG. 3 is a sectional view taken along line VII-VII of FIG. FIG. 3 is a sectional view taken along line VIII-VIII of FIG. FIG. 3 is a sectional view taken along line IX-IX of FIG. FIG. 3 is a cross-sectional view taken along the line X-X of FIG. FIG. 3 is a sectional view taken along line XI-XI of FIG. It is a side view of a hinge pillar inner. It is a perspective view of a hinge pillar inner. It is a side view of the tip member. It is a perspective view of the tip member. It is a deformation explanatory view of the tip member. It is a figure which shows the hinge pillar inner and the tip part in the process of deformation. It is a side view of a rain outer member. It is a perspective view of the rain outer member. It is a side view of a cowl side reins. It is a perspective view of a cowl side reins. It is a figure which shows the cowl side reins in the process of deformation. It is a side view of the tip member which concerns on the modification. It is a perspective view of the tip member which concerns on the modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies the application of the present invention to the front body structure of a vehicle, and does not limit the present invention, its application, or its use.

Hereinafter, Example 1 of the present invention will be described with reference to FIGS. 1 to 22.
As shown in FIGS. 1 and 2, the vehicle V includes a floor panel 1 constituting the floor surface of the vehicle interior, a pair of left and right side sills 2 extending in the front-rear direction, and an engine room (not shown) formed in the front portion of the vehicle body. A dash panel 3 that separates the vehicle interior from the vehicle interior, a pair of left and right front side frames 4 that extend forward from the dash panel 3, and a pair of left and right hinge pillars 20 that extend vertically upward from the front end of the pair of side sills 2. , A pair of left and right apron reinforcements (hereinafter, abbreviated as apron rain) 30 and the like extending forward from the upper end portion of the pair of hinge pillars 20 are provided.

During a so-called small overlap collision, an obstacle collides with this vehicle V on the outer part in the vehicle width direction (overlap area is 25% or less) of the front side frame represented by the SORB (Small Overlap Rigid Barrier) test. The apron rain 30 is provided with an inward bending deformation mechanism that inwardly bends and deforms the apron rain 30 inward in the vehicle width direction without causing buckling accompanied by out-of-plane deformation. This inward bending deformation mechanism has an inner inner bending guiding function that induces deformation of the apron rain 30 from the inner side of the apron rain 30, and an outer inner bending guiding function that induces deformation of the apron rain 30 from the outer side of the apron rain 30. have.
Hereinafter, since the vehicle V is configured to have a symmetrical structure, the right side portion will be mainly described. Further, in the figure, the arrow F direction is the front in the front-rear direction of the vehicle body, the arrow OUT direction is the outside in the vehicle width direction, and the arrow U direction is the upper direction in the vehicle body vertical direction.

First, the schematic configuration of the vehicle V will be described.
The side sill 2 is provided so as to extend back and forth along both ends of the floor panel 1 in the vehicle width direction. The side sill 2 has a side sill outer having a substantially hat-shaped cross section opened inward in the vehicle width direction and a side sill inner having a substantially hat-shaped cross section opened outward in the vehicle width direction (both are not shown). The flanges are joined to form a closed cross section that extends back and forth.

As shown in FIG. 2, the dash panel 3 is arranged so as to extend in the vehicle width direction across the pair of hinge pillars 20. The dash panel 3 includes a dash lower panel (not shown) that rises upward from the front end portion of the floor panel 1, and a dash upper panel 3a joined to the upper end portion of the dash lower panel.
A cowl inner panel extending in the vehicle width direction is joined to the rear end of the dash upper panel 3a, and a cowl outer panel extending in the vehicle width direction is joined to the front side of the cowl inner panel (both are not shown).

The pair of front side frames 4 are arranged between the pair of side sills 2 in a plan view. A suspension tower (hereinafter abbreviated as a suspension tower) 5 for supporting a damper of a front wheel suspension (not shown) is formed between the front side frame 4 and the apron rain 30. The suspension tower 5 integrally includes a wheel house 6 for accommodating the front wheels and suspensions for the front wheels. The wheel house 6 is formed on the front side of the dash panel 3 and in the lower region of the apron rain 30.

The wheel house 6 includes a partial bowl-shaped wheel house outer (not shown) arranged outside the pillar inner member 22 of the hinge pillar 20, which will be described later, and a partial bowl-shaped wheel house inner 6a arranged inside the pillar inner member 22. It is equipped with. The wheel house inner 6a is joined to the front side frame 4 and the pillar inner member 22, and the wheel house outer is joined to the pillar inner member 22 and the lower side of the apron rain 30.

Next, a pair of hinge pillars 20 will be described.
As shown in FIGS. 1 to 7, the hinge pillar 20 includes a pillar outer member 21 having a substantially hat-shaped cross section and a plate-shaped pillar inner member 22 forming a substantially rectangular closed cross section extending upward in cooperation with the pillar outer member 21. have. The pillar outer member 21 and the pillar inner member 22 are made of high-strength steel or ultra-high-strength steel.
The pillar outer member 21 is composed of a main body portion 21a having a substantially U-shaped cross section and a pair of front and rear flange portions 21b extending forward and rearward from the front end portion and the rear end portion of the main body portion 21a.
In order to attach the door hinges to the upper and lower portions of the main body 21a, a pair of upper and lower hinge attachment portions bulging outward in the vehicle width direction are formed respectively.

The pillar inner member 22 has an inner inner bending guiding function.
As shown in FIGS. 12 and 13, the pillar inner member 22 has a main body portion 22a that cooperates with the main body portion 21a to form a substantially rectangular parallelepiped closed cross section, and an upper extension extending forward from the upper end portion of the main body portion 22a. A portion 22b and a lower extension portion 22c extending rearward from the lower end portion of the main body portion 22a are provided. A pair of front and rear flange portions 21b of the pillar outer member 21 are joined to the front portion and the rear portion of the main body portion 22a by spot welding, respectively. The side sill outer and the side sill inner are joined with the lower extension portion 22c interposed therebetween. Therefore, the closed cross section of the side sill 2 is divided into inside and outside in the vehicle width direction by the lower extension portion 22c.

The upper extension portion 22b is formed in a substantially triangular shape when viewed from the side. A tip member 23 (tip portion) is attached to the front end portion of the upper extension portion 22b. The tip member 23 is set to have substantially the same plate thickness as the pillar inner member 22, and is made of high-strength steel, for example.
As shown in FIGS. 14 and 15, the tip member 23 has a substantially trapezoidal main body portion 23a in a side view and a joint portion 23b bent inward in the vehicle width direction from the upper end portion of the main body portion 23a. is doing.
The joint portion 23b is joined to the lower wall portion 31c of the apron rain 30, which will be described later, by spot welding. The joint strength between the joint portion 23b and the apron rain 30 is set higher than the buckling strength of the fragile portion 23e and the protruding portion 23d.

The main body portion 23a is a connecting portion 23c joined to the front end portion of the upper extension portion 22b at the rear portion by spot welding, a protruding portion 23d protruding inward in the vehicle width direction at the lower front side, and a rear side of the protruding portion 23d. Moreover, it is provided with a fragile portion 23e set at a position on the front side of the connecting portion 23c. The buckling strength of the fragile portion 23e and the protruding portion 23d is set to be lower than the joint strength of the joint portion 23b.
The protrusion 23d is composed of a triangular bead whose base is open and whose two sides are defined by ridges. Specifically, the rear ridge line is arranged so as to be substantially parallel to the connecting portion 23c formed in a forward downward inclination, and the front ridge line is arranged so as to be substantially parallel to the horizontally formed joint portion 23b. Is located in.

An opening 23f is formed in a region near the intersection of the front and rear ridges, that is, in a region close to the so-called joint portion 23b and the connecting portion 23c, with the aim of reducing weight and rigidity. The opening 23f may be single or may be two or more. The tip member 23 is configured to have a lower tensile strength than the pillar inner member 22 and the rain outer member 31. The tensile strength of the rain outer member 31 is set lower than the tensile strength of the pillar inner member 22.

As shown in FIG. 16, when a backward collision load is applied to the apron rain 30 (rain outer member 31) at the time of a small overlap collision, the ridge lines corresponding to the two sides of the protrusion 23d are divided and the openings are formed. Since the portion 23f is formed, the stress transmitted to the central portion of the protruding portion 23d is concentrated and medial buckling that bends inward in the vehicle width direction occurs. Since the pillar inner member 22 has a stronger tensile strength than the tip member 23, the outer buckling that folds outward in the vehicle width direction in the region corresponding to the fragile portion 23e in synchronization with the medial buckling of the central portion generated in the protruding portion 23d. Occurs. Since the buckling strength of the fragile portion 23e and the protruding portion 23d is set lower than the joint strength of the joint portion 23b, the buckling of the fragile portion 23e and the protruding portion 23d should be generated earlier than the breakage of the joint portion 23b. Can be done.

The posture of the joint portion 23b is changed by buckling of the fragile portion 23e and the protruding portion 23d.
By changing the posture of the joint portion 23b by using the buckling of the fragile portion 23e and the protruding portion 23d, the stress acting on the joint portion 23b is converted from the shear stress to the compressive stress, and the apron rain 30 and the pillar inner member 22 are combined. The breakage of the joint is further suppressed. As a result, as shown by the arrow in FIG. 17, the tip member 23 converts a part of the stress flowing backward in the apron rain 30 into a component toward the inside in the vehicle width direction, and the upper extension portion 22b is inward in the vehicle width direction. Pressing (induction of inward bending).

Next, the apron rain 30 will be described.
As shown in FIGS. 1 to 3, the apron rain 30 has a straight portion 30a extending forward from the connecting portion with the hinge pillar 20 and a curved portion 30b extending inward and downward in the vehicle width direction from the front end portion of the straight portion 30a. And have. As a result, a wheel house 6 capable of accommodating a tire having a widened tire width is formed below the apron rain 30 (straight line portion 30a).

As shown in FIGS. 7 to 11, the apron rain 30 includes an apron rain outer member (hereinafter, abbreviated as rain outer member) 31 extending from the front end portion of the hinge pillar 20 to the front end portion of the vehicle V, and the rain outer member 31. It has an apron rain inner member (hereinafter, abbreviated as rain inner member) 32 extending from the middle portion of the vehicle V to the front end portion of the vehicle V.
The rain inner member 32 having a substantially L-shaped cross section is provided so as to correspond to the front half portion of the rain outer member 31, and forms a closed cross section having a substantially rectangular cross section extending in the front-rear direction in cooperation with the rain outer member 31. Specifically, the latter half of the rain outer member 31 forms a straight line portion 30a, and the front half of the rain outer member 31 and the rain inner member 32 form a curved portion 30b forming a closed cross section.

The rain outer member 31 has an inner bending guidance function of the outer.
As shown in FIGS. 18 and 19, the rain outer member 31 includes an outer surface portion 31a formed of surfaces substantially orthogonal to the vehicle width direction, and an upper wall portion 31b extending outward in the vehicle width direction from the upper end portion of the outer surface portion 31a. It is provided with a lower wall portion 31c extending inward in the vehicle width direction from the lower end portion of the outer surface portion 31a.
Of the outer surface portions 31a, the outer surface portion 31a corresponding to the straight line portion 30a is provided with a horizontal bead portion 31s, a first vertical bead portion 31t, and a second vertical bead portion 31u.

The lateral bead portion 31s projecting outward in the vehicle width direction is formed in the vertical middle stage portion of the outer surface portion 31a so as to extend in the front-rear direction from the rear end portion of the straight line portion 30a to the vicinity of the front end portion.
As shown in FIGS. 8 to 10, the horizontal bead portion 31s is formed to have a substantially rectangular cross section.
The vertical dimension of the horizontal bead portion 31s is set in the range of 15% to 30% of the vertical dimension of the rear end portion of the rain outer member 31. In the present embodiment, the vertical dimension of the horizontal bead portion 31s is set to approximately 20% of the vertical dimension of the rear end portion of the rain outer member 31.
As shown in FIGS. 7 to 10, the lateral bead portion 31s has a smaller cross-sectional area (amount of protrusion outside in the vehicle width direction) toward the front, in other words, the line L connecting the cross-sectional center of gravity of the lateral bead portion 31s is toward the front. It is configured to move inward in the width direction.

As a result, since the cross-sectional area of the lateral bead portion 31s is reduced toward the front, the rigidity in the front-rear direction of the rain outer member 31 is set to be lower toward the front, and the rain outer member 31 and the hinge pillar 20 are set at the time of a small overlap collision. It constitutes a deformation promoting portion that concentrates stress on the connecting portion with the pillar outer member 21. Further, since the line L connecting the cross-sectional center of gravity of the lateral bead portion 31s is configured to shift inward in the vehicle width direction toward the front, the stress flowing through the rain outer member 31 is converted into the stress toward the inward in the vehicle width direction.

The first vertical bead portion 31t is formed so as to extend in the front side region of the horizontal bead portion 31s in the vertical direction and to be recessed inward in the vehicle width direction. The front-rear dimension of the first vertical bead portion 31t is set to be larger than the front-rear dimension of the second vertical bead portion 31u and smaller than the vertical dimension of the horizontal bead portion 31s. As a result, at the time of a straight collision, the rain outer member 31 is deformed inward in the vehicle width direction starting from the first vertical bead portion 31t, and the impact energy is absorbed.

The second vertical bead portion 31u is formed so as to extend upward from the intermediate portion in the front-rear direction of the horizontal bead portion 31s to the upper wall portion 31b and to project outward in the vehicle width direction.
As shown in FIG. 3, the second vertical bead portion 31u is arranged at an upper position of the tip member 23 in a side view, and is arranged at a position in the front-rear direction substantially the same as the position in the front-rear direction of the tip member 23.
As a result, during a small overlap collision, the stress flowing backward in the rain outer member 31 is concentrated on the second vertical bead portion 31u, and in cooperation with the tip member 23, the stress acts on the rain outer member 31 toward the inside in the vehicle width direction. The stress component can be increased.

As shown in FIGS. 2 to 4, the inner panel 11, the hinge rain 12, and the hinge bracket 13 are joined to the upper end portion of the upper wall portion 31b.
The inner panel 11 connects the dash upper panel 3a and the upper end portion of the upper wall portion 31b. The inner panel 11 is provided from the rear end portion of the upper wall portion 31b to a position in the front-rear direction corresponding to the second vertical bead portion 31u. In the present embodiment, the outer front end portion of the inner panel 11 is arranged so as to be in front of the rear end portion of the second vertical bead portion 31u and behind the front end portion of the second vertical bead portion 31u.

As shown in FIGS. 8 to 11, the hinge rain 12 is a member for fixing the hinge (not shown) of the bonnet to the upper extension portion 22b and the upper wall portion 31b. The hinge rain 12 is joined to the lower side of the inner panel 11 and is provided at a position in the front-rear direction corresponding to a position near the front end of the lateral bead portion 31s from the rear end portion of the upper wall portion 31b.

The hinge bracket 13 is a member for attaching the hinge of the bonnet to the upper part of the hinge rain 12. The front end portion of the hinge bracket 13 is arranged so as to be in front of the rear end portion of the second vertical bead portion 31u and behind the outer front end portion of the inner panel 11. As a result, at the time of a small overlap collision, the downward stress acting on the upper wall portion 31b corresponding to the front side region of the hinge bracket 13 can be supported by the second vertical bead portion 31u, which is generated in the upper wall portion 31b. Avoids downward buckling.

As shown in FIGS. 1 to 6 and 8, the rain outer member 31 is connected to the pillar outer member 21 via a cowl side reins 24 (cowl side reins forcement). The cowl side reins 24 are joined to the pillar outer member 21 by spot welding so as to partially overlap the right end portion of the upper hinge mounting portion, and are joined to the upper side portion of the front pillar 7. As shown in FIGS. 20 and 21, the cowl side reins 24 have a horizontal bead portion 24a and a vertical bead portion 24b (upper and lower bead portions).

The lateral bead portion 24a projecting outward in the vehicle width direction is formed in the middle portion of the cowl side reins 24 in the vertical direction so as to extend in the front-rear direction from the rear end portion to the vicinity of the front end portion.
As shown in FIG. 8, the horizontal bead portion 24a is formed to have a substantially rectangular cross section. When the cowl side reins 24 are joined to the rain outer member 31, the lateral bead portion 24a is partially superimposed on the lateral bead portion 31s from the inside in the vehicle width direction.

The vertical bead portion 24b is formed so as to extend vertically from the lower side of the horizontal bead portion 24a toward the upper end and recess inward in the vehicle width direction in the front region of the horizontal bead portion 24a.
At the time of a small overlap collision, when the stress flowing backward through the rain outer member 31 (horizontal bead portion 31s) is transmitted to the cowl side reins 24, the stress is distributed in the vertical direction along the vertical bead portion 24b. As a result, as shown by the arrow in FIG. 22, the stress flowing backward in the rain outer member 31 can be applied to the inside in the vehicle width direction over a wide range in the vertical direction by the vertical bead portion 24b. The rain outer member 31 can be guided to bend and deform inward at the rear end portion.

Next, the operation and effect of the front vehicle body structure of the vehicle V according to the embodiment of the present invention will be described.
According to the present embodiment, the hinge pillar 20 has a pillar outer member 21 arranged on the outer side in the vehicle width direction, and a pillar inner member 22 forming a closed cross section extending vertically in cooperation with the pillar outer member 21. Since the member 22 includes a main body portion 22a having a surface orthogonal to the vehicle width direction and a tip member 23 extending forward from the main body portion 22a at a position substantially the same height as the rain outer member 31 (apron rain 30), the pillar inner is provided. The member 22 can be formed by the main body portion 22a and the tip member 23 joined to the main body portion 22a. Between the joint portion 23b in which the tip member 23 is joined to the rear portion of the rain outer member 31, the fragile portion 23e formed in the vicinity of the joint portion 23c connected to the main body portion 22a, and between the joint portion 23b and the fragile portion 23e. Since it has a protruding portion 23d formed so as to project inward in the vehicle width direction, the posture of the joint portion 23b can be changed by buckling of the fragile portion 23e and the protruding portion 23d. Since the buckling strength of the fragile portion 23e and the protruding portion 23d is set lower than the joint strength of the joint portion 23b, the buckling of the fragile portion 23e and the protruding portion 23d is earlier than the breakage of the rain outer member 31 and the joint portion 23b. Can be generated in. Moreover, by changing the posture of the joint portion 23b by using the buckling of the fragile portion 23e and the protruding portion 23d, the stress acting on the joint portion 23b is converted from the shear stress to the compressive stress, and the rain outer member 31 and the tip member 23 are used. It is possible to suppress the breakage of the joint with the (pillar inner member 22) and contribute the buckling strength of the pillar inner member 22 to the impact energy absorption.

Since the fragile portion 23e is composed of the strength difference between the material strength of the main body portion 22a and the material strength of the tip member 23, the fragile portion 23e can be formed by the material strength difference between the main body portion 22a and the tip member 23.

Since the protruding portion 23d is composed of a triangular bead having two ridges and an open base, the fragile portion 23e is moved inward in the vehicle width direction by using the deformation of the protruding portion 23d at the time of a small overlap collision. It can be guided to be bent.

Next, a modified example in which the embodiment is partially modified will be described.
1] In the above embodiment, an example in which the fragile portion 23e is configured by the strength difference between the material strength of the main body portion 22a and the material strength of the tip member 23 has been described, but the fragile portion 23e is larger than the plate thickness of the main body portion 22a. The plate thickness of the tip member 23 may be reduced. As a result, even if the main body portion 22a and the tip member 23 have the same tensile strength, the fragile portion 23e can be formed by the plate thickness of the main body portion 22a and the plate thickness of the tip member 23. Further, the fragile portion 23e may be formed by etching processing, slit processing, or the like.

Further, as shown in FIGS. 23 and 24, the fragile portion 23g may be formed of a bead formed on the tip member 23A. Specifically, a fragile portion 23g made of a bead projecting outward in the vehicle width direction is formed at a position on the rear side of the projecting portion 23d and on the front side of the connecting portion 23c. This makes it possible to form a fragile portion with a simple structure without using material strength or plate thickness.

2] In addition, a person skilled in the art can carry out the embodiment in a form in which various modifications are added to the embodiment or a combination of the embodiments without departing from the spirit of the present invention, and the present invention is such. It also includes various modified forms.

20 Hinging pillar 21 Pillar outer member 22 Pillar inner member 23 Tip member (tip)
23b Joint 23d Protruding 23e, 23g Vulnerable part 30 Apron Rain 31 Rain outer member V Vehicle

Claims (5)

In the front body structure of a vehicle equipped with a pair of left and right apron reinforcements extending in the front-rear direction of the vehicle body and a pair of left and right hinge pillars connected to the rear ends of each pair of apron reinforcements.
The hinge pillar has a hinge pillar outer member arranged outside in the vehicle width direction, and a hinge pillar inner member that cooperates with the hinge pillar outer member to form a closed cross section extending vertically.
The hinge pillar inner member includes a main body portion having a surface orthogonal to the vehicle width direction, and a tip portion extending forward from the main body portion at a position substantially the same as the apron reinforcement.
The tip portion is joined to the rear portion of the apron reinforcement, the fragile portion formed near the connecting portion with the main body portion, and the vehicle width direction between the joint portion and the fragile portion. With a protrusion formed to project inward,
A front vehicle body structure of a vehicle, characterized in that the buckling strength of the fragile portion and the protruding portion is set lower than the joint strength of the joint portion. The front body structure of a vehicle according to claim 1, wherein the fragile portion is formed by a strength difference between the material strength of the main body portion and the material strength of the tip portion. The front body structure of a vehicle according to claim 1 or 2, wherein the fragile portion is configured by making the plate thickness of the tip portion thinner than the plate thickness of the main body portion. The front vehicle body structure of a vehicle according to claim 1, wherein the fragile portion is composed of a bead formed on the tip portion. The front body structure of a vehicle according to any one of claims 1 to 4, wherein the protruding portion is composed of a triangular bead having two ridges and an open base.

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