This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2015-156219 filed on Aug. 6, 2015, the disclosure of which is incorporated by reference herein.
Technical Field
The present disclosure relates to a vehicle body framework structure.
Related Art
Japanese Patent Application Laid-Open (JP-A) No. 2008-24019 describes a structure in which a reinforcement member is inbuilt (built-in) to a hollow elongated bumper member (hollow framework member).
However, in cases in which the above structure is applied to a bumper member made of carbon-fiber reinforced plastic (CFRP) or a bumper member made of aluminum alloy, it is conceivable that the bumper member breaks or yields at a portion located at an end of the inbuilt reinforcement member.
In consideration of the above circumstances, in a vehicle body framework structure in which a reinforcement member is inbuilt in a hollow framework member, the present disclosure provides a vehicle body framework structure in which the framework member is suppressed from breaking or yielding.
An aspect of the present disclosure is a vehicle body framework structure including a framework member that is formed in an elongated tube shape; and a reinforcement member that is disposed inside the framework member, that the reinforcement member including a main portion that contacts both of a pair of opposing inner faces of the framework member, and a leading end portion having a shape that gradually separates away from both of the pair of inner faces.
In the vehicle body framework structure of the present aspect, the reinforcement member is provided inside the framework member foinied in an elongated tube shape. The reinforcement member includes the main portion and the leading end portion. The main portion contacts both of the pair of opposing inner faces of the framework member. The framework member is thereby reinforced by a portion of the reinforcement member where the main portion is disposed, such that the cross-section of the framework member is suppressed from collapsing.
The leading end portion has a shape that gradually separates away from both the pair of opposing inner faces of the framework member. Thus, in cases in which load in a direction in which the above-mentioned pair of inner faces oppose each other is input to the framework member, and the framework member undergoes bending deformation, the inner faces of the framework member warp while making contact with the leading end portion of the reinforcement member. As a result, a concentration of stress is thereby suppressed from occurring, and warping by a fixed amount or greater is also suppressed. As a result the framework member is suppressed from breaking or yielding.
In the above aspect, the framework member may be a bumper reinforcement extending along a vehicle width direction and that is configured to be attached to both of a pair of front ends of coupling members extending along a vehicle front-rear direction on either vehicle width direction side of a vehicle front section, a pair of the reinforcement member may be disposed respectively at both of a pair of vehicle width direction ends of the bumper reinforcement, and each of the reinforcement members may be disposed such that the leading end portion is directed toward a vehicle width direction inside, and the main portion is disposed at a position including a portion of the bumper reinforcement facing the front end of the respective coupling member.
In the above structure, for example, in cases in which a small overlap collision of the vehicle has occurred (for example, among vehicle front-on collisions, a collision with an overlap amount with a colliding body of 25% or less in the vehicle width direction as specified by Insurance Institute for Highway Safety (IIHS)), the bumper reinforcement is suppressed from breaking partway along the vehicle width direction. As a result, collision energy can be efficiently absorbed, and the load can be efficiently transmitted to the coupling member.
The main portion may have a rectangular cross-section profile in a direction orthogonal to a length direction of the reinforcement member. Also with this configuration, a concentration of stress is suppressed from occurring, and warping by a fixed amount or greater is suppressed. As a result the framework member is suppressed from breaking or yielding.
Alternatively, the main portion may have a hat shaped cross-section profile in a direction orthogonal to a length direction of the reinforcement member. In the above configuration, the main portion may include a front wall that contacts a first face of the pair of opposing inner faces of the framework member; an upper wall and a lower wall that extend from each respective end portion of the front wall toward a second face of the pair of opposing inner faces of the framework member; and a pair of rear walls that extend from respective end portions of the upper wall and the lower wall contacting the second face, and extend along the second face. Also with the above configuration, a concentration of stress is suppressed from occurring, and warping by a fixed amount or greater is suppressed. As a result the framework member is suppressed from breaking or yielding. Further, the cost of manufacture of the vehicle body framework structure may be reduced.
Exemplary embodiments will be described in detail based on the following figures, wherein:
Explanation follows regarding a first exemplary embodiment, with reference to
The framework member 12 is an elongated shaped member with a rectangular cross-section profile, which has a space inside (i.e., it is hollow). The reinforcement member 14 is provided at one end portion of the framework member 12 (for example, the right end portion), this being an inner portion of the framework member 12.
The reinforcement member 14 is configured by a front wall 14F, an upper wall 14U, a rear wall 14R and a lower wall 14L, and has a rectangular cross-section profile when cut along a plane orthogonal to the left-right direction (length direction of the framework member 12). In the cross-section profile of the leading end portion 18 of the reinforcement member 14, the spacing between the front wall 14F and the rear wall 14R gradually narrows as the leading end portion 18 extends away from the main portion 16. In contrast, the spacing between the upper wall 14U and the lower wall 14L of the reinforcement member 14 is substantially uniform throughout the length of the reinforcement member 14.
As illustrated in
Note that as illustrated in
The front wall 14F of the reinforcement member 14 is curved so as to be convex toward the front direction at the leading end portion 18. The rear wall 14R of the reinforcement member 14 is curved so as to be convex toward the rear direction at the leading end portion 18. In the above manner, the front wall 14F and the rear wall 14R of the reinforcement member 14 are both curved, and end portions at the other end side (left side) of the reinforcement member 14 are smoothly connected together. In other words, the front wall 14F and the rear wall 14R of the reinforcement member 14 are curved to form a convex shape projecting toward the left direction at the leading end portion 18.
As illustrated in
Next, explanation follows regarding operation and effects of the present exemplary embodiment.
In the vehicle body framework structure S1 of the present exemplary embodiment, the reinforcement member 14 is provided inside the hollow framework member 12. The reinforcement member 14 includes the main portion 16, and the leading end portion 18 formed continuously to the main portion 16. The main portion 16 is configured with a shape contacting each of the pair of opposing inner faces 20, 22 of the framework member 12. The framework member 12 is thereby reinforced at a portion of the reinforcement member 14 where the main portion 16 is disposed, and the cross-section of the framework member 12 is suppressed from collapsing.
In contrast, the leading end portion 18 is configured with a shape that gradually separates away from both of the pair of opposing inner faces 20, 22 of the framework member 12. Thus, for example, in cases in which load in the opposing direction of the pair of inner faces 20, 22 (the front-rear direction) is input to the framework member 12, and the framework member 12 undergoes bending deformation, as illustrated in
Explanation follows employing a vehicle body framework structure S10 of a comparative example illustrated in
In contrast, in the vehicle body framework structure S1 of the present exemplary embodiment, the reinforcement member 14 includes the leading end portion 18 in addition to the main portion 16. As illustrated in
Explanation follows regarding a second exemplary embodiment according to the present disclosure, with reference to
A vehicle body framework structure S2 of the second exemplary embodiment differs from the first exemplary embodiment only in the shape of a reinforcement member 34, and so explanation follows regarding the reinforcement member 34.
The reinforcement member 34 of the second exemplary embodiment is configured in a hat shape.
The front wall 34F and the rear wall 34R of the reinforcement member 34 are separated from the pair of opposing inner faces 20, 22 of the framework member 12 at the leading end portion 18 illustrated in
As described above, the reinforcement member 34 of the second exemplary embodiment greatly differs from the reinforcement member 14 of the first exemplary embodiment in cross-section profile orthogonal to the length direction of the framework member 12. However, the shape of the reinforcement member 34 in plan view is substantially the same as that of the reinforcement member 14 of the first exemplary embodiment.
The second exemplary embodiment configured in this manner also exhibits similar operation and effects to those explained in the first exemplary embodiment. Moreover, in the second exemplary embodiment, the reinforcement member 34 is easy to form due to being configured in a hat shape, thereby enabling the cost of manufacture of the vehicle body framework structure S2 to be reduced.
Explanation follows regarding a third exemplary embodiment according to the present disclosure, with reference to
The bumper reinforcement 40 is a framework member provided extending along the vehicle width direction, and is disposed at the vehicle rear of a front bumper (not illustrated in the drawings) of a vehicle. A pair of left and right crash boxes 42 are attached to the vehicle rear of the bumper reinforcement 40. The crash boxes 42 are disposed with their axes oriented substantially along the vehicle front-rear direction, and rear portions of the crash boxes 42 are connected to front side members (not illustrated in the drawings), these being framework members extending along substantially the vehicle front-rear direction. The front side members are coupled to a vehicle body structure at a section configuring the vehicle cabin. The crash boxes 42 and the respective front side members may be regarded as coupling members extending along the vehicle front-rear direction at both width direction sides of the vehicle front section. The crash boxes 42 and the respective front side members correspond to “coupling members” in the present disclosure.
A pair of left and right reinforcement members 14 are disposed at both vehicle width direction ends, these being portions inside the bumper reinforcement 40. In each reinforcement member 14, the main portion 16 faces toward the vehicle width direction outside, and the leading end portion 18 faces toward the vehicle width direction inside. The leading end portion 18 does not reach the vehicle width direction center of the bumper reinforcement 40, and the length of the reinforcement member 14 in the vehicle width direction is approximately one third the length of the bumper reinforcement 40. Both vehicle width direction end sections of the bumper reinforcement 40 have a shape angled toward the vehicle rear side. The main portions 16 of the reinforcement members 14 are thereby formed so as to match the angled shapes of the bumper reinforcement 40. The reinforcement members 14 are disposed at positions that respectively include each of the two ends of the bumper reinforcement 40. Namely, both ends of the bumper reinforcement 40 are suppressed from cross-sectional collapse by the main portion 16 of the reinforcement member 14.
The main portions 16 of the reinforcement members 14 are disposed at sections (framework facing sections 40A) of the bumper reinforcement 40 facing toward the front ends of the crash boxes 42. Namely, the main portion 16 of each reinforcement member 14 is disposed at positions that include the framework facing section 40A of the bumper reinforcement 40.
Explanation follows regarding operation and effects of the third exemplary embodiment.
In the third exemplary embodiment, in cases in which a colliding body W has been involved in a small overlap collision, as illustrated in
Moreover, cross-sectional collapse of the bumper reinforcement 40 is suppressed at sections of the bumper reinforcement 40 where the reinforcement members 14 are provided. In particular, collision load can be efficiently transmitted to the crash boxes 42 and the front side members such that the crash boxes 42 and the front side members can be made to absorb the collision energy due to disposing the main portions 16 of the reinforcement member 14 at positions that include the framework facing sections 40A of the bumper reinforcement 40.
In the vehicle body framework structure S3 of the third exemplary embodiment as described above, the bumper reinforcement 40 can be suppressed from breaking, and collision load can be efficiently transmitted to the crash boxes 42 and the front side members.
In each of the exemplary embodiments described above, the cross-section profile of the framework member 12 is configured in a rectangular shape; however, the exemplary embodiments are not limited thereto and, for example, the cross-section profile of the framework member may be substantially hexagonal. The material of the framework member and the reinforcement member is not limited to CFRP, and for example, may be glass fiber reinforced plastic (GFRP) or an aluminum alloy. Moreover, the framework member and the reinforcement member may be configured by different materials. The hollow framework member may be formed by welding two sheet members together.
In each of the exemplary embodiments described above, the reinforcement member 14 is joined to the framework member 12 by vibration welding; however, the exemplary embodiments are not limited thereto. For example, joining may be performed using an adhesive. The reinforcement member may be joined to the framework member by welding or by rivets.
In the third exemplary embodiment, explanation has been given in which an embodiment of the present disclosure is applied to (front) bumper reinforcement 40. However, application may be made to various other vehicle body framework members such as rear bumper reinforcement, front pillars, center pillars, rear pillars, rockers (side sills), or roof side rails.
When viewed in respective horizontal cross-sections running along the length direction of the framework member 12, the reinforcement member 14 of the first exemplary embodiment is equipped with the leading end portions 18 shaped so as to separate away from both of the pair of the inner faces 20, 22 from the same point; however, the present disclosure is not limited thereto. In other words, in the first exemplary embodiment, as illustrated in
In the above exemplary embodiments, explanation has been given in which a reinforcement member has a rectangular cross-section profile or a hat shaped cross-section profile; however, the exemplary embodiments are not limited thereto. Various shapes may be employed as long as they are shapes that include the main portion contacting the opposing inner faces 20, 22 of the framework member 12 and the leading end portion gradually separating away from the pair of inner faces 20, 22. The reinforcement member 14, 34 in the respective exemplary embodiments above are provided with the leading end portion 18 on one side (for example, the left side) of the main portion 16. However, the exemplary embodiments are not limited thereto, and a pair of leading end portions may be included on both sides of the main portion (on the left and right sides thereof).
Number | Date | Country | Kind |
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2015-156219 | Aug 2015 | JP | national |