Technical field
[0001]
The present invention relates to a vehicle rear structure.
BACKGROUND
[0002]
Recently, in view of global environmental protection, improved fuel economy of automobiles has been required. On the other hand, maintenance of the collision safety of the vehicle and improved it is required. To satisfy these requirements, the development of high strength and lightweight vehicle body structure has been advanced. For example, around the frame members, such as frames or pillars, the application of high-strength steel sheet thin is promoted.
[0003]
　It is one of the skeletal members, a rear frame provided on left and right in the vehicle rear portion, by causing bending deformation by an impact load from the vehicle rear, absorbing the collision energy. Such improvements development of the technology according to the impact energy absorbing performance by the rear frame is in progress.
[0004]
　For example, the following Patent Document 1, the technology according to the rear frame bead portion is provided in the bottom wall portion, and the bent portion that is bent inside the vertical wall portion is provided is disclosed. Such techniques, it is possible to increase the bending deformation load caused by an impact load. That improves collision energy absorption performance of the rear frame. Further, the following Patent Document 2, a rear floor panel formed of mild steel plate, the rear floor structure and a rear frame formed by high-tensile steel having high strength than the rear floor panel is disclosed. Such techniques, while maintaining a small amount of deformation of the vehicle body with respect to impact loads, it is possible to increase the impact energy absorption.
CITATION
Patent Document
[0005]
Patent Document 1: JP 2015-89759 JP
Patent Document 2: JP 2004-291714 JP
Summary of the Invention
Problems that the Invention is to Solve
[0006]
　To accommodate fuel efficiency standards for automobiles being future stringent, it is required to further reduce the weight of the body structure. However, when further working to further thinning of the skeleton member, such as a rear frame, at the time of action of the impact load member axial sectional collapse occurs rather than the desired bending deformation in the rear frame. Therefore, it is difficult to obtain a plastic workload (= collision energy absorption amount) with the desired bending deformation, comprising if there is often lower than the performance of the absorption performance of the collision energy was assumed at the time of designing. Therefore, as in the technique disclosed in Patent Document 1 and 2, a structure as to absorb voluntarily collision energy to the rear frame, compatibility between further weight reduction of the body structure and desired impact energy absorbing performance It is difficult.
[0007]
　To further promote the weight reduction of the body structure while maintaining the collision safety against impact from the rear of the vehicle, not just rear frame, also absorbs the impact energy to the rear floor panel that did not play a role of a conventional collision energy absorption be thought the inventors useful. However, the design concept of the rear floor panel is mainly to absorb the impact energy has not been studied at all so far.
[0008]
　The present invention has been made in view of the above problems, it is an object of the present invention, while maintaining the collision safety against impact from the vehicle rear, is possible to reduce the weight of the body structure possible to provide a new and improved vehicle rear structure.
Means for Solving the Problems
[0009]
　In order to solve the above problems, according to an aspect of the present invention, a pair of rear frame installed in the vehicle length direction, the metal plate having a tensile strength of at least the pair of the rear frame towards the rear of the vehicle in the vehicle front in a recess which is formed, it comprises a rear floor panel which is joined to the pair of rear frame, the vehicle rear portion structure is provided.
[0010]
　The rear floor panel has a pair of flat portions on both ends in the vehicle width direction via the pair of plane portions is joined to the pair of rear frame, the recess is provided between the pair of flat portions it may be.
[0011]
　The pair of flat portions has a frame-shaped portion extending in the vehicle length direction, at least a portion of the frame-shaped portion of the pair of flat portions, may be joined to the pair of rear frames.
[0012]
　Said each of at least a portion of the side wall of the frame-shaped portion and the respective side wall of the pair of rear frames may be bonded via a bonding portion.
[0013]
　At least a portion of the side wall of each of the frame-shaped portion is provided with a first fitting groove extending in the vehicle height direction, the sidewalls of each of the pair of rear frames, the corresponding to the first groove 2 fitting groove is provided, the first groove may be fitted into the second fitting groove.
[0014]
　The inside of the frame-shaped portion may be in contact with the contact member is provided to the side walls of both the opposing of the frame-shaped portion.
[0015]
　The recess may be a spare tire storage portion.
[0016]
　The bottom portion of the spare tire storage space, at least, from one end to the other end in the vehicle width direction of the bottom portion, the high rigidity region may be provided with a rigidity higher than the rigidity of the pair of flat portions.
[0017]
　The bottom portion of the spare tire storage space, at least, from one end to the other end in the vehicle width direction of the bottom portion, even when a high strength region having a higher tensile strength than the tensile strength of the pair of flat portions are provided good.
[0018]
　The recess extends in the longitudinal direction of the vehicle may have a plurality of grooves shape which are arranged in parallel in the vehicle width direction.
[0019]
　Said recess is provided at both ends in the vehicle width direction of the rear floor panel, at least a portion of each of said recesses, may be joined to a pair of rear frame installed in the vehicle length direction.
[0020]
　And each of the side walls of at least a portion of the side walls and the pair of rear frame of each of the recesses may be bonded via a bonding portion.
[0021]
　At least a portion of the side wall of each of the recess is provided with a first fitting groove extending in the vehicle height direction, the sidewalls of each of the pair of the rear frame, a second fitting corresponding to the first groove grooves are provided, the first groove may be fitted into the second fitting groove.
[0022]
　Inside the recess, it abuts the abutting member may be provided to both opposite side walls of the recess.
[0023]
　The intermediate portion located between each of the recess in the vehicle width direction in the rear floor panel, from one end to the other end in the vehicle width direction of the intermediate portion, in the vehicle width direction outer side portion of said intermediate portion of the rear floor panel high rigidity region may be provided having a higher rigidity than the rigidity.
[0024]
　The intermediate portion located between each of the recess in the vehicle width direction in the rear floor panel, from one end to the other end in the vehicle width direction of the intermediate portion, in the vehicle width direction outer side portion of said intermediate portion of the rear floor panel high intensity regions may be provided with a higher tensile strength than the tensile strength.
[0025]
　The thickness of the metal plate in the high rigidity region may be larger than the plate thickness of the metal plate in the portion other than the above high-rigidity region of the rear floor panel.
[0026]
　The aforementioned metal plate in the high rigidity region, the sheet member made of a resin may be bonded.
[0027]
　The aforementioned metal plate in the high rigidity region, connects the cylinder of a plurality of the same height, the top surface of the cover one end portion of each of the cylindrical body, and the respective other ends of the tubular body resin structure comprising a base portion, are joined through the top surface, the said base of the resin structure, a sheet member made of resin or paper may be joined.
[0028]
　The metal plate in the high rigidity region may have an irregular shape.
[0029]
　The joint is welded portion, the fastening portion may be at least one of the bonding portion or the caulking joint.
[0030]
　The weld may be formed in a linear shape continuous with bent in the vehicle length direction.
[0031]
　The welds may be formed by laser welding and / or arc welding.
[0032]
　The welds may be formed by spot welding or arc spot welding.
[0033]
　The contact member may be formed of resin or metal.
[0034]
　The recess may be provided from the vehicle length direction rear end of the rear floor panel.
[0035]
　The tensile strength of the recess may be more than 980 MPa.
[0036]
　In the vehicle length direction, the rear end of the recess may be positioned behind the rear end of the pair of rear frames.
[0037]
　The rear floor panel may be a press-molded product obtained by press molding a sheet of the work plate.
[0038]
　It said one of the work plate includes a first metal plate portion corresponding to the portion including at least the concave portion, a second metal plate corresponding to the sites contained in the rear floor panel other than site comprising the at least the recess is constituted by a part, the tensile strength per unit width of the first metal plate may be higher than the tensile strength per unit width of the second metal plate. Incidentally, the target plate may be, for example, a tailored blank. More specifically, the workpiece plate is tailor weld blank having a weld line; may be (Tailor Welded Blank TWB). Further, the target plate, the first metal plate is thick tailor rolled blanks than the second metal plate; may be (Tailor Rolled Blank TRB). The tensile strength herein means the product of the tensile strength of the plate thickness and material.
[0039]
　According to the above arrangement, when an impact load is applied from the rear of the vehicle, rather than the rear frame, the rear floor panel to absorb the collision energy with the impact load direction a concave sectional shape (concave). Strength of the recess of the rear floor panel has a rear frame equal or higher, the seat in the recess rather than by the cross-sectional area of ​​the end portion acting impact load of the recess is greater than the cross-sectional area of ​​the rear frame in bending deformation in the recess屈変 form is likely to occur. Thus, the rear floor panel and it is possible to mainly absorb the collision energy caused by the impact load from the vehicle rear. Therefore, the absorption load of the collision energy by the rear frame is reduced, it is possible to thin, and short of the rear frame. Therefore, weight reduction of the vehicle body rear portion, weight of the entire vehicle body is realized thus.
Effect of the invention
[0040]
　According to the present invention described above, while maintaining the collision safety against impact from the vehicle rear, it is possible to reduce the weight of the vehicle body structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041]
It is a lower perspective view showing a vehicle rear portion structure according to a first embodiment of FIG. 1 the present invention.
It is a cross-sectional view of a vehicle rear structure in FIG 2] II-II section line of Figure 1.
A [3] schematic diagram showing a structure of a rear floor panel obtained by press-forming a structure and target plate of the work plate (schematic sectional view).
[4] a rear frame according to the embodiment is lower perspective view of the shortening of been vehicle rear structure.
5 is a sectional view according to a modification of the vehicle rear portion structure according to the embodiment.
It is a lower perspective view of a vehicle rear structure according to the second embodiment of FIG. 6 the present invention.
It is a cross-sectional view of a vehicle rear structure in FIG 7] VII-VII section line of Figure 6.
Is a cross-sectional view of a vehicle rear structure in FIG. 8] VIII-VIII section line of FIG.
Is a sectional view according to another embodiment of the vehicle rear structure in FIG 9] VIII-VIII section line of FIG.
It is a sectional view according to a modification of the vehicle rear portion structure according to [10] the same embodiment.
11 is a bottom perspective view of a vehicle rear structure according to a third embodiment of the present invention.
Is a cross-sectional view of a vehicle rear structure in FIG. 12] XII-XII cut line of Figure 11.
13 is a sectional view of a vehicle rear structure according XIII-XIII section line of Figure 11.
It is a sectional view according to another embodiment of the vehicle rear structure in FIG. 14] XIII-XIII section line of Figure 11.
15 is a diagram showing an example of the high rigidity region provided on the bottom surface portion in accordance with an embodiment of the present invention.
16 is a diagram showing a configuration example of a resin structure and the sheet member according to an embodiment of the present invention.
17 is a sectional view showing an example of a joint according to an embodiment of the present invention.
18 is a diagram showing an example of a welded portion formed in a linear continuous while bent in the vehicle length direction.
[Figure 19A] first fitting groove is a sectional view showing a first example showing the state of the frame-shaped portion and the rear frame when being fitted to the second fitting groove.
[Figure 19B] first fitting groove is a sectional view showing a second example showing the frame-shaped portion and the state of the rear frame when fitted into the second fitting groove.
Is a diagram showing a first example of FIG. 20A] contact member.
It is a diagram showing a second example of FIG. 20B] contact member.
DESCRIPTION OF THE INVENTION
[0042]
　Reference will now be described in detail preferred embodiments of the present invention. In the specification and the drawings, components having substantially the same function and structure are a repeated explanation thereof by referring to the figures.
[0043]
　<< 1. Background >>
　Before describing the configuration of a vehicle rear portion structure according to each embodiment of the present invention will be described background to conceive the present invention.
[0044]
　Conventionally, the rear frame is skeletal member has a higher tensile strength than the rear floor panel, the rear frame was responsible for absorbing proactively collision energy against an impact load from the vehicle rear. However, if further reduction in thickness of the skeletal member, such as a rear frame, so sectional collapse tends to occur rather than the desired bending deformation in the rear frame when the action of the impact load, the absorption performance of the collision energy of the rear frame at design It is likely to be lower than had been expected performance. It is also possible to introduce the filler or bulk head or the like in order to suppress collapse section of the rear frame, the vehicle weight is increased, it is difficult to promote weight reduction further.
[0045]
　On the other hand, the conventional rear floor panel, since the tensile strength, such as mild steel plates were formed by a low steel, is the role of absorbing the impact energy on the rear floor panel has not been expected.
[0046]
　However, the rear floor panel, when an impact due to collision from the rear of the vehicle, plastically deformed together with the rear frame. Therefore, with the configuration as the rear floor panel to absorb the collision energy to demonstrate the large plastic workload during plastic deformation during a collision and not be able to reduce the burden on the absorption of the collision energy by the rear frame or with the present invention we have found.
[0047]
　The present inventors have studied intensively, by increasing the strength of the recess having a cross-sectional concave shape of the spare tire storage space such as provided conventionally on the rear floor panel, to deform the recess in the event of a collision, the rear floor panel by the modified and I conceived that it is possible to absorb the collision energy subjectively. In particular, since the rear floor panel is a member provided integrally with the vehicle width direction, it is larger cross-sectional area of ​​the working end an impact load is applied. Therefore, when an impact load is applied, hardly bent facilitate rear floor panel. Thus, rather than the bending deformation as the rear frame, continuous buckling deformation occurs in the rear floor panel. Since such buckling deformation is large work load in the plastic deformation as compared to the bending deformation, absorption of impact energy in the case of high tensile the rear floor panel is larger than the absorption quantity of the collision energy by the rear frame. That is, it is possible to rear floor panel is mainly absorb collision energy.
[0048]
　If proactively collision energy is absorbed by the rear floor panel, load is reduced according to the collision energy absorption of the rear frame. Thus, it is possible to reduce the strength which has been conventionally required to the rear frame, it is possible to further thinning or shortening of the rear frame. From the above, by transferring a principal role in the absorption of impact energy from the rear frame to the rear floor panel, the collision while maintaining safety, and the present inventors do not can achieve weight reduction of the overall body structure thought did.
[0049]
　The present inventors have developed a vehicle rear portion structure capable of rear floor panel absorbs voluntarily collision energy. As a result, while maintaining the collision safety was shown to be capable of achieving weight reduction of the overall body structure. The following describes the structure of the vehicle rear portion structure according to each embodiment of the present invention.
[0050]
　In the following description, the terms indicating the context such as "front", "rear" or "rear" is, unless otherwise distinguishing, denote the direction or position related in the vehicle length direction.
[0051]
　<< 2. First Embodiment
　　>> <2.1. Configuration>
　First, with reference to FIGS. 1 and 2 to describe the configuration of the vehicle rear structure 1 according to the first embodiment of the present invention. Figure 1 is a bottom perspective view of a vehicle rear structure 1 of the present embodiment. Figure 2 is a cross-sectional view of a vehicle rear structure 1 of the II-II section line of Figure 1.
[0052]
　As shown in FIG. 1, the vehicle rear structure 1 according to the present embodiment includes a rear floor panel 2, and a rear frame 4, 4. The rear floor panel 2 according to the present embodiment has a spare tire storage portion 3 in the center. The spare tire storage portion 3 is an example of a recess having the rear floor panel 2. Spare tire storage space 3, from the rear of the rear floor panel 2 is provided toward the vehicle front. Spare tire storage space 3 is the rear floor panel 2 integrally formed. The dimensions of the vehicle length direction and the vehicle width direction of the spare tire storage portion 3 is appropriately set depending on the size of the spare tire such that the dimensions of the vehicle or loading.
[0053]
　Note that the spare tire storage portion 3 according to the present embodiment, the rear floor panel 2, is preferably provided from the rear end of the vehicle. By having a cross section in a perpendicular cross section in the longitudinal direction of the vehicle from the rear end of the vehicle, it is possible to increase the absorption amount of the collision energy by the rear floor panel 2 from the start of the collision. Thus, it is possible to shorten the deformation stroke of the vehicle direction by the collision.
[0054]
　The rear frame 4 is a frame member that is provided in the vehicle length direction. Specifically, a pair of rear frames 4, in the left and right sides of the vehicle are provided extending in the vehicle length direction. Such rear frame 4, for example, as shown in FIG. 2, having a groove shape in which the upper side is opened. As the steel plate forming the rear frame 4, for example, tensile strength steel sheet may be used which is 590MPa grade or 780MPa class.
[0055]
　Further, as shown in FIG. 2, a pair of left and right flat portions 5 is provided in the vehicle width direction of both ends of the rear floor panel 2. Each of the opening edge portion of the rear frame 4 is bonded to each of the flat portion 5. The bonding method of the rear frame 4 and the flat portion 5 is not particularly limited. For example, two members are joined by known techniques, such as spot welding.
[0056]
　Spare tire storage portion 3 according to the present embodiment is provided between the pair of flat portions 5,5. The spare tire storage portion 3 is formed by a steel sheet having a tensile greater than the strength or equivalent tensile strength, of the rear frame 4. Specific tensile strength of the steel sheet forming the spare tire storage portion 3 is appropriately set in accordance with the tensile strength, and the required collision safety of the rear frame 4. For example, the steel plate which forms a spare tire storage portion 3 is preferably a tensile strength of high-tensile steel of more than 980 MPa. From the viewpoint of moldability, it is preferable tensile strength of the steel sheet forming the spare tire storage portion 3 is less steel 1780MPa. Thickness and shape of the spare tire storage portion 3, in view of the balance of the collision safety and vehicle weight may be set as appropriate.
[0057]
　With this configuration, when the vehicle is rear-ended, the impact load acts on the spare tire storage space 3, the spare tire storage portion 3 is buckled and deformed. This allows the rear floor panel 2 absorbs the initiative in collision energy. Accordingly, since the load is reduced according to the absorption of the collision energy by the rear frame 4, it is possible to rear frame 4 thinned, or short of. As a result, weight reduction of the vehicle body structure can be realized.
[0058]
　Incidentally, the rear floor panel 2 according to the present embodiment may be a press-molded product obtained by press-forming a sheet of the work plate. Such target plate includes a first steel plate portion corresponding to the spare tire storage space 3, even tailored blank constituted by a second steel plate portion corresponding to the portion other than the spare tire storage space 3 good. Such tailored blanks, for example, Taylor weld blank obtained by welding a plurality of steel sheets of different material or thickness before press-forming (Tailor Welded Blank; TWB), or to adjust the pressure of the cold rolling roller it may be; (TRB tailor rolled blank) tailor rolled blank is steel piece having a plurality of different thickness by. The first steel plate portion and the second steel part are examples of the first metal plate and the second metal plate.
[0059]
　Figure 3 is a schematic diagram showing the configuration of a rear floor panel 2 which is obtained by press-forming a structure and target plate 100 of the work board 100 (schematic sectional view). As shown in FIG. 3, target plate 100 consists of a first steel plate portion 101, and the second steel plate 102. By press-molding the target plate 100, the rear floor panel 2 is obtained. Here, the first steel plate portion 101 corresponds to a portion including a spare tire storage portion 3 after press molding, the second steel plate 102, the rear floor other than the site containing the spare tire storage portion 3 after press molding corresponding to the site of the panel 2. For example, a second steel sheet 102 corresponding to the planar portion 5 of the rear floor panel 2, the first steel plate portion 101, corresponding to each part of the rear floor panel 2 including a spare tire storage portion 3. Since the first steel plate portion 101 corresponding to the spare tire storage space 3, which is an example of a concave portion, the tensile strength of the first steel plate portion 101, it is required greater than the tensile strength of the rear frame 4. The second steel plate 102 is not borne the proactive role of collision energy absorption during the action of an impact load. Therefore, the tensile strength of the second steel plate 102 is not particularly limited. The tensile strength herein means the product of the tensile strength of the plate thickness and material.
[0060]
　Therefore, in the target plate 100 that is a tailored blank, the tensile strength per unit width of the first steel plate portion 101 is preferably greater than the tensile strength per unit width of the second steel plate 102. Thus, it is possible to only a spare tire storage portion 3 to prepare a rear floor panel 2 with high tensile strength. Therefore, it is possible to the forming process of the rear floor panel 2, from the viewpoints of moldability and cost, more efficient.
[0061]
　Although the tensile strength of the spare tire storage space 3 is higher than the tensile strength of the rear frame 4 in this embodiment, for example, the site of the rear floor panel 2 except the spare tire storage portion 3, the spare tire storage space 3 same tensile strength may be formed by steel plates having a. More specifically, the entire rear floor panel 2 may be formed by one sheet of steel plate having a high tensile strength than the tensile strength of the rear frame 4. At least if the tensile strength of the spare tire storage portion 3 of the rear floor panel 2 is higher than the tensile strength of the rear frame 4, or if the same type of steel constituting the site of the rear floor panel 2 except the spare tire storage space 3 It is not particularly limited.
[0062]
　Further, the bottom portion 300 of the spare tire storage portion 3, the outer portion of the bottom portion 300 (e.g., flat portion 5) may be a region having a higher tensile strength than the tensile strength of the (high strength region) is provided . The high strength region, at least, be provided from one end 300a in the vehicle width direction of the bottom portion 300 toward the other end 300b. The high intensity regions may be provided on all or part of the bottom portion 300. By increasing the tensile strength of the bottom portion 300, a portion between the pair of rear frame 4 of the rear floor panel 2, even if the object from the rear of the vehicle has collided, the bottom portion 300 of the vehicle direction the it is possible to prevent the object from entering.
[0063]
　Further, as described later, when the high-rigidity region is provided on the bottom surface 300, by increasing the tensile strength of the bottom portion 300, extending the range of the elastic deformation to maintain the rigidity of the bottom portion 300 be able to. Thereby, since the rear frame 4 is hardly twisted relatively, it is possible to increase the collision safety.
[0064]
　Rear floor panel 2 including a bottom portion 300 of the spare tire storage portion 3 having such high strength region, for example, pressing a tailored blank containing relatively high steel sheet portion a tensile strength of a portion corresponding to the bottom portion 300 It can be obtained by.
[0065]
　Although the cross-sectional shape of the spare tire storage portion 3 shown in FIG. 2 is dish-shaped, may be, for example, V-shaped or U-shaped or the like. The cross-sectional shape of the spare tire storage portion 3, and satisfies the collision safety required, and is not particularly limited as long as the shape that can reduce the weight. Although the spare tire storage portion 3 shown in FIG. 2 is an example of a recess, the recess may not necessarily be a spare tire storage portion. For example, the concave portion may be a trunk space is provided for accommodating luggage, etc., as described below, may be a groove formed to ensure crashworthiness.
[0066]
　The cross-sectional shape of the spare tire storage portion 3 of the bottom portion 300 shown in FIG. 2 is has a horizontal straight line, the shape of the bottom surface 300 of the spare tire storage portion 3 is not particularly limited. For example, the cross-sectional shape of the bottom portion 300 of the spare tire storage portion 3 may be a curve. Further, the bottom portion 300 of the spare tire storage portion 3 may contain further at least one concavo-convex shape.
[0067]
　Further, the bottom portion 300 of the spare tire storage portion 3, the outer portion of the bottom portion 300 (e.g., flat portion 5) may be a region having a higher stiffness than the stiffness of the (high-rigidity region) is provided. The high-rigidity region is at least, be provided from one end 300a in the vehicle width direction of the bottom portion 300 toward the other end 300b. As described later, the high rigidity region may be provided on all or part of the bottom portion 300.
[0068]
　By providing the high-rigidity region on the bottom surface 300 toward the other end 300b from one end 300a in the vehicle width direction of the bottom portion 300, hardly twisted bottom portion 300 which occupies an area of ​​most of the rear floor panel 2. In this case, even if action impact load toward the rear of the vehicle, since the rear floor panel 2 is hard to twist, a pair of rear frame 4 is less likely twisted relatively. Then, the rear frame 4 is reliably restrained by the rear floor panel 2. Thus, the deformation mode of the rear frame 4 is stabilized, it is possible to maximize the collision safety of the vehicle rear structure 1.
[0069]
　Further, by providing the high-rigidity area on the bottom surface 300, it is possible to reduce the sound transmission loss. Thus, the bottom portion 300 to shield the noise and vibration, such as road noise, can be easily transmitted noise and vibration inside the vehicle. Thus, comfort of the vehicle interior can be improved.
[0070]
　The specific means of high rigidity in the high rigidity region of the bottom portion 300 will be described later.
[0071]
　The depth of the recess 3 of the vehicle rear portion structure according to the present embodiment (the spare tire storage portion 3) is preferably at least 50mm. When the depth of the recess is 50mm smaller, because the absorption of impact energy by the recess of the cross-sectional shape can not be obtained sufficiently. The provisions of the depth of the recess 3, the following and the embodiments, the same applies to the other embodiments according to the present invention. Here, the depth of the recess 3, in the vertical direction, the length of the flat portion 5 to the bottom surface portion 300 of the recess 3.
[0072]
　　<2.2. The first modification (shortening of)>
　Next, a description will be given of a first modification of the vehicle rear structure 1 of the present embodiment. In this modified example, a description will be given of a vehicle rear structure 1 comprises a rear frame 4, which is short of. Figure 4 is a bottom perspective view of a vehicle rear structure 1 of the rear frame 4 is short of. As shown in FIG. 4, the rear frame 4 provided in the vehicle length direction, the rear end 4a is provided so as to be positioned in front of the vehicle than the rear end 3a of the spare tire storage portion 3 of the rear floor panel 2. In other words, the length of the rear frame 4 shown in FIG. 4, the length (FIG. 1 of the rear frame 4 shown in FIG. 1, the rear end and the rear end of the spare tire storage portion 3 of the rear frame 4 is vehicle length direction shorter than the same position) at. When the vehicle having the vehicle rear structure 1 having such a configuration is collision, the impact load acts on the rear end of the spare tire storage portion 3, the rear floor panel 2 by the spare tire storage portion 3 is buckled but to absorb the collision energy. Therefore, the rear frame 4 is also provided in front of the rear end of the spare tire storage portion 3, since the rear floor panel 2 to absorb the collision energy, the collision safety of the vehicle is secured. Therefore, an amount corresponding to the rear frame 4 is short of, it is possible to reduce the weight of the body structure.
[0073]
　Incidentally, short of the rear frame 4 is joinable rear frame 4 and the rear floor panel 2, and preferably buckling deformation of the rear floor panel 2 is performed in order not extend with respect to room area. Rear floor panel 2 is generally provided across the room space and trunk region (region a spare tire storage portion 3 is provided). When the buckling deformation of the rear floor panel 2 will extend up to the room area, it may range danger to passengers aboard the room area. Therefore, the rear frame 4, across at least a room area to the rear from the front of the vehicle, and the rear end of the rear frame 4 preferably has a length that is provided so as to be positioned in the trunk region side. More specifically, it is preferable that the rear end 4a of the rear frame 4 than the wheel house portion or rear suspension member (not shown) is provided to be positioned on the vehicle rear side. Thus, when an impact load acts on the rear end of the rear floor panel 2, since the development of buckling deformation of the rear floor panel 2 by a suspension member and the rear frame 4 is suppressed, thereby reducing the effect of impact on the room area be able to.
[0074]
　　<2.3. Second modification (groove shape)>
　Next, a description will be given of a second modification of the vehicle rear structure 1 of the present embodiment. In this modification, in place of the spare tire storage space 3, a description will be given of a vehicle rear structure 1 in cross section a recess 3A is a plurality of grooves shape. Figure 5 is a sectional view according to a modification of the vehicle rear structure 1 of the present embodiment. Sectional view shown in FIG. 5 is a cross-sectional view taken along a line corresponding to the position corresponding to the II-II section line included under perspective view of a vehicle rear structure 1 shown in FIG. As shown in FIG. 5, the rear floor panel 2, instead of the spare tire storage space 3, two recesses 3A cross section extending and vehicle length direction a groove shape, 3A is, the pair of flat portions 5 between, they are arranged in parallel in the vehicle width direction. Two recesses 3A, 3A is integrally formed with the rear floor panel 2. In this case, since an impact load from the vehicle rear to increase the effect the cross-sectional area of the rear floor panel 2 acting, multiple recesses 3A of the cross-section groove shape as shown in FIG. 5, the rear end of the rear floor panel 2 It is provided from over the front of the vehicle. Accordingly, even in a vehicle body structure having no spare tire storage portion, and an impact load is acting from the rear of the vehicle to the rear end of the concave portion 3A, the recesses 3A are mainly absorb collision energy. Therefore, since the burden is reduced according to the absorption of the collision energy by the rear frame 4, it becomes possible to thin and short of the rear frame 4.
[0075]
　In the example shown in FIG. 5, the recess 3A is has a groove shape in which the upper side is open, the present invention is not limited to such an example. For example, the shape of the recess 3A may have a groove shape that the lower side is opened. The cross-sectional shape of the recess 3A is not particularly limited as long as the shape which can increase the vehicle length direction of the second moment of the recesses 3A. Further, the vehicle length direction of the length of the recesses 3A, and the vehicle width direction of the width can be appropriately adjusted from the viewpoint of collision safety or formability.
[0076]
　Further, the vehicle rear structure 1, for example, steel plate (not shown) may be provided in the upper portion of the recessed portion 3A so as to cover at least one recess 3A shown in FIG. 5, by the recess 3A and the steel plate closed cross section may be formed. The steel plate may be formed of the same material as the recess 3A. Moreover, such a closed cross section, for example, may be rectangular cross section or square cross-sectional structure. By forming a closed section structure including a recessed portion 3A by using the steel plate, it is possible to further increase the absorption of collision energy. Incidentally, even when the concave portion 3A shown in FIG. 5 is provided only one rear floor panel 2 may be closed cross section by a steel plate of the recessed portion 3A and the (not shown) is formed.
[0077]
　Further, the intermediate portion 301 located between the two recesses 3A, 3A shown in FIG. 5, the outer middle 301 portions (e.g., flat portion 5) area (high-rigidity area having a higher rigidity than the rigidity of the ) may be provided. The high-rigidity region is at least, be provided from one end 301a in the vehicle width direction of the intermediate portion 301 toward the other end 301b. As described later, the high rigidity region may be provided on all or part of the intermediate portion 301.
[0078]
　By providing the high-rigidity region to the intermediate portion 301 toward the other end 301b from one end 301a in the vehicle width direction of the intermediate portion 301, similarly, the pair of rear frame 4 is less likely twisted relatively. Then, the rear frame 4 is reliably restrained by the rear floor panel 2. Thus, the deformation mode of the rear frame 4 is stabilized, it is possible to maximize the collision safety of the vehicle rear structure 1.
[0079]
　Further, by providing the high rigidity region to the intermediate portion 301, it is possible to reduce the sound transmission loss. Thus, the intermediate portion 301 to shield the noise and vibration, such as road noise, can be easily transmitted noise and vibration inside the vehicle. Thus, comfort of the vehicle interior can be improved.
[0080]
　The specific means of high rigidity in the rigid region of the intermediate portion 301 will be described later.
[0081]
　Further, the intermediate portion 301, the outer portion of the intermediate portion 301 (e.g., flat portion 5) may be a region having a higher tensile strength than the tensile strength of the (high strength region) is provided. The high strength region, at least, be provided from one end 301a in the vehicle width direction of the intermediate portion 301 toward the other end 301b. The high intensity regions may be provided on all or part of the intermediate portion 301. By increasing the tensile strength of the intermediate portion 301, a portion between the pair of rear frame 4 of the rear floor panel 2, even if the object from the rear of the vehicle has collided, the intermediate portion 301 of the vehicle direction the it is possible to prevent the object from entering.
[0082]
　Further, when the rigidity of the intermediate portion 301, it is possible to extend the possible range of elastic deformation to maintain the rigidity of the intermediate portion 301. Accordingly, the pair of the rear frame 4 is hardly twisted relatively, it is possible to increase the collision safety.
[0083]
　Such rear floor panel 2 includes an intermediate portion 301 having a high strength region, for example, obtained by a tailored blank containing relatively high steel sheet portion a tensile strength of a portion corresponding to the intermediate portion 301 for pressing.
[0084]
　<< 3. Second Embodiment >>
　Next, the configuration of the vehicle rear portion structure 10 according to the second embodiment of the present invention. Figure 6 is a bottom perspective view of the vehicle rear structure 10 of the present embodiment. Figure 7 is a cross-sectional view of the vehicle rear structure 10 in VII-VII section line of Figure 6. 8 is a cross-sectional view of the vehicle rear structure 10 of the VIII-VIII section line of FIG.
[0085]
　As shown in FIG. 6, the vehicle rear portion structure 10 according to the present embodiment includes a rear floor panel 20, and a rear frame 4, 4. Further, as shown in FIG. 7, the rear floor panel 20 has a spare tire storage portion 3 in the center. The spare tire storage portion 3 is an example of a recess having the rear floor panel 20. Spare tire storage space 3 is integrally formed with the rear floor panel 20. Spare tire storage space 3, from the rear end of the vehicle rear structure 10 is provided toward the vehicle front.
[0086]
　Rear frame 4 according to the present embodiment is formed by a steel sheet having the same tensile strength and the rear frame 4 provided in the vehicle rear portion structure 10 according to the first embodiment, members having the upper side opened groove shape it is. Further, the rear frame 4 according to the present embodiment, as shown in FIG. 6, a rear frame having a length such rear end 4a of the rear frame 4 to the front than the rear end 3a of the spare tire storage portion 3 is positioned it may be. The rear frame 4 may be a rear frame having a length the same position at the rear end and vehicle length direction of the spare tire storage space 3.
[0087]
　Steel sheet forming the spare tire storage portion 3, as in the first embodiment of the present invention, higher than the tensile strength of the rear frame 4, or equivalent of the steel sheet. Specifically, the tensile strength of the steel sheet forming the spare tire storage portion 3 is preferably at least 980 MPa.
[0088]
　Further, as shown in FIG. 7, a pair of left and right flat portions 50, 50 are provided in the vehicle width direction of both ends of the rear floor panel 20. Further, each of the flat portion 50, the upper side is opened, the frame-shaped portion 51 of the channel shape extending in the vehicle length direction are provided, respectively. Some of the frame-shaped portion 51 is joined to the rear frame 4. For example, as shown in FIGS. 6 and 8, the outer surface of the frame-shaped portion 51 is bonded to the inner surface of the rear frame 4. Thus, part of the impact load acts on the rear floor panel 20 is transmitted to the rear frame 4 via a frame-shaped portion 51.
[0089]
　With this configuration, the frame-shaped portion 51 and the rear frame 4 of the rear floor panel 20, will be joined by a shear joint shape in side and bottom surfaces of the hat shape. Then, reduced delamination stresses at the joint between the frame-shaped portion 51 and the rear frame 4, as well as a problem in the case of the joining of each other ultrahigh-strength steel sheet peeling is suppressed, the contact area of ​​the rear floor and the frame portion it is possible to earn. As a result, you are possible to increase the bonding area. Accordingly, when the vehicle length direction of the length of the rear frame 4 becomes shorter, it is possible to reduce the possibility that the joining portion of the rear frame 4 and the rear floor panel 20 is peeled off by the impact load. Therefore, when the rear floor panel 20 to absorb the collision energy is buckled, it is possible to restrain the direction of the buckling more reliably. Therefore, it is possible to maintain the absorption performance of the collision energy by the rear floor panel 20.
[0090]
　Further, when joining the frame-shaped portion 51 and the rear frame 4, preferably the side wall of the frame-shaped portion 51 (the outer surface) side wall (inner surface) of the rear frame 4 and are bonded together via the bonding portion. The junction, the side surfaces and the rear frame 4 of the frame-shaped portion 51 is welded, means a bonding portion by a fastening or the like.
[0091]
　When an impact load acts proactively against the rear floor panel 20, the rear floor panel 20 shows a modified mode in which apart from the rear frame 4. Then, the force is pulled in the in-plane direction of the joint surface of both side walls of which constitute the joint portion (shearing force) is generated in the rear floor panel 20 and the rear frame 4. Then, as in the so-called shear fracture mode, behaves like the bonding surfaces is shifted in the plane direction is generated at the junction.
[0092]
　If, consider a case where the joining only the bottom surface of the bottom and the rear frame 4 of the frame-shaped portion 51. In this case, when an impact load is proactively acts on the rear floor panel 20, the force pulled out of plane direction of the bonding surface of the bottom of both constituting the junction, resulting in the rear floor panel 20 and the rear frame 4. Then, as in the so-called plug fracture mode, it behaves like the joint surface peeling occurs at the joint.
[0093]
　Generally, the tensile shear strength of one joint (Tensile Shear Strength: TSS) is cross tensile strength (Cross Tension Strength: CTS) tends to be higher than the. That is, the tensile strength of the shear direction of the bonding surface associated with the shear breaking mode, than the tensile strength of the peeling direction of the joint surface associated with the plug breaking mode is dominant. Here, by joining the side wall and the side wall of the rear frame 4 of the frame-shaped portion 51, it is possible to cause the behavior of the shear breaking mode at the junction. That is, when an impact load is applied against the rear floor panel 20, since the behavior of shear fracture mode is indicated rather than a plug rupture mode, the bonding strength of the joint is increased substantially. Therefore, it is possible to hardly cause rupture of the joint. Therefore, separation of the rear floor panel 20 and the rear frame 4 is less likely to occur.
[0094]
　In this case, it is possible to impact load against the rear floor panel 20 is in when the acting from the rear of the vehicle, increase the bonding strength of the joint. That is, it is possible to hardly cause rupture of the joint. Then, also act against high impact loads rear floor panel 20, breaking of the joint is not generated sufficiently support the rear floor panel 20 rear frame 4 via a joint. Thus, the rear floor panel 20 which receives the impact load is not bent to the inside of the vehicle, plastically deformed receiving the impact load. This allows the rear floor panel 20 to absorb the collision energy. Therefore, it is possible to prevent the transmission and the entrance of the collision and the like of the impact force to the vehicle inside. Therefore, it is possible to increase the vehicle collision safety.
[0095]
　Incidentally, according to strength and weight of the steel sheet, the shear fracture mode than plug fracture mode, be a further advantage with respect to the tensile strength was shown. In particular, the tensile strength for the steel sheet is more than 780 MPa, the difference in tensile strength between two breaking modes described above has been shown that significantly greater. That is, by increasing the strength and weight of the steel plate forming the rear floor panel 20, the bonding strength of the joint according to the present embodiment is further increased, it is possible to hardly cause bonding fracture. Thus, by the steel sheet forming the rear floor panel 20 is high strength and light weight, collision safety exerted is further increased by the vehicle rear structure 1 of the present embodiment.
[0096]
　For specific means for realizing the joint, it will be described later.
[0097]
　Further, as described in the first embodiment, the bottom surface 300 of the spare tire storage portion 3, the outer portion of the bottom portion 300 (e.g., flat portion 5) regions with a higher rigidity than the rigidity (high rigidity region) may be provided. The high-rigidity region is at least, be provided from one end 300a in the vehicle width direction of the bottom portion 300 toward the other end 300b. As described later, the high rigidity region may be provided on all or part of the bottom portion 300.
[0098]
　Further, as described in the first embodiment, the bottom portion 300, the outer portion of the bottom portion 300 (e.g., flat portion 5) regions with a higher tensile strength than the tensile strength of the (high strength region) it may be provided. The high strength region, at least, be provided from one end 300a in the vehicle width direction of the bottom portion 300 toward the other end 300b. The high intensity regions may be provided on all or part of the bottom portion 300.
[0099]
　The frame-shaped portion 51 shown in FIG. 6 or the like may not necessarily provided entirely over the front end from the rear end of the flat portion 50. For example, the frame-shaped portion 51, in the vehicle length direction, may be provided partially over the front from an intermediate portion of the flat portion 50.
[0100]
　Further, the rear frame 4 shown in FIGS. 6 and 8 may not flange is provided. Figure 9 is a sectional view according to another embodiment of the vehicle rear structure in VIII-VIII section line of FIG. As shown in FIG. 9, a frame-shaped portion 51 of the flange without the rear frame 4 and the rear floor panel 20, if it is bonded with each other aspects and / or bottom, presence of the flange in the rear frame 4 is not particularly limited .
[0101]
　The rear floor panel 20 according to this embodiment, the recess may have a closed cross section formed by the portion covering the recess. Figure 10 is a sectional view according to a modification of the vehicle rear structure 10 of the present embodiment. As shown in FIG. 10, the rear floor panel 20 of the present modification, the closed-section portion 3 is provided comprising a hat-shaped section 3B and the flat plate portion 3C at the center thereof. The closed cross-section structure shown in FIG. 10, it is possible to further increase the absorption amount of impact energy. In the example shown in FIG. 10, but the flat portion 3C is provided continuously with the flat portion 50, the hat-shaped portion 3B may be provided continuously with the flat portion 50.
[0102]
　<< 4. Third Embodiment >>
　Next, the configuration of the vehicle rear portion structure 11 according to a third embodiment of the present invention. Figure 11 is a bottom perspective view of the vehicle rear structure 11 of the present embodiment. Figure 12 is a cross-sectional view of the vehicle rear structure 11 of the XII-XII cut line of Figure 11. 13 is a cross-sectional view of the vehicle rear structure 11 of the XIII-XIII section line of Figure 11.
[0103]
　As shown in FIG. 11, the vehicle rear structure 11 of the present embodiment includes a rear floor panel 21, and the rear frame 4, 4. Further, as shown in FIG. 12, in the vehicle width direction of both ends of the rear floor panel 21, the upper side is opened, a pair of left and right recesses 30, 30 of the channel shape extending in the vehicle length direction are provided. Recess 30 is integrally formed with the rear floor panel 21. Incidentally, the rear floor panel 21 according to this embodiment, the spare tire storage portion shown in the previous embodiment does not have.
[0104]
　Rear frame 4 according to the present embodiment is formed by a steel sheet having the same tensile strength and the rear frame 4 provided in the vehicle rear portion structure 10 according to the first embodiment, members having the upper side opened groove shape it is. Rear frame 4 according to the present embodiment, as shown in FIG. 11, the rear end of the rear floor panel 21 (i.e., the rear end 30a of the recess 30) length, such as the rear end 4a of the rear frame 4 forwardly located than it may be a rear frame having a of. The rear frame 4 may be a rear frame having a length the same position at the rear end and vehicle length direction of the rear floor panel 21.
[0105]
　Recess 30 according to this embodiment, the rear end of the rear floor panel 21 is provided toward the vehicle front. A part of the recess 30 is joined to the rear frame 4. For example, as shown in FIGS. 11 and 13, the outer surface of the concave portion 30 is bonded to the inner surface of the rear frame 4. Thus, part of the impact load acts on the rear floor panel 21 is transmitted to the rear frame 4 via a recess 30.
[0106]
　Steel sheet to form a recess 30 according to this embodiment, as in the first embodiment of the present invention, higher than the tensile strength of the rear frame 4, or equivalent of the steel sheet. For example, the tensile strength of the steel sheet forming the recess 30 is preferably at least 980 MPa.
[0107]
　With this configuration, when an impact load is applied from the rear of the vehicle, since the rear floor panel 21 including the concave portion 30 is buckled, and it is possible to absorb voluntarily collision energy. Thus, the burden on the absorption of the collision energy by the rear frame 4 is reduced, it is possible to rear frame 4 thinned, or short of. Moreover, to improve the living space of the weight and the vehicle by omitting the spare tire, even if the spare tire storage portion is not provided on the rear floor panel 21, the rear floor panel 21 instead of the rear frame 4 is mainly it is possible to absorb the collision energy basis.
[0108]
　Moreover, as in the second embodiment, when bonding the recess 30 and the rear frame 4, the side wall of the recess 30 (the outer surface) and the side wall of the rear frame 4 and the (inner surface) are bonded via the bonding portion Rukoto is preferable. The junction, the side wall of the recess 30 and the side wall of the rear frame 4 is welded, means a bonding portion by a fastening or the like.
[0109]
　Such joint, when an impact load is applied from the rear of the vehicle relative to the rear floor panel 21, the joint represents the behavior of shear fracture mode. Thus, the bonding strength of the bonded portion is further increased, it is possible to hardly cause bonding fracture. Therefore, it is possible to prevent the transmission and the collision object such as penetration of the impact force to the vehicle inside. Therefore, it is possible to increase the vehicle collision safety.
[0110]
　Further, an intermediate portion 201 located between the two recesses 30, 30 shown in FIGS. 12 and 13, the outer portion of the intermediate portion 201 of the rear floor panel 21 (e.g., recess 30) a rigidity higher than the rigidity of the area (high-rigidity region) may be provided with. The high-rigidity region is at least, be provided from one end 201a in the vehicle width direction of the intermediate portion 201 toward the other end 201b. As described later, the high rigidity region may be provided on all or part of the intermediate portion 201.
[0111]
　By providing the high-rigidity region to the intermediate portion 201 toward the other end 201b from one end 201a in the vehicle width direction of the intermediate portion 201, similarly, the pair of rear frame 4 is less likely twisted relatively. Then, the rear frame 4 is reliably restrained by the rear floor panel 2. Thus, the deformation mode of the rear frame 4 is stabilized, it is possible to maximize the collision safety of the vehicle rear structure 1.
[0112]
　Further, by providing the high rigidity region to the intermediate portion 201, it is possible to reduce the sound transmission loss. Thus, the intermediate portion 201 to shield the noise and vibration, such as road noise, can be easily transmitted noise and vibration inside the vehicle. Thus, comfort of the vehicle interior can be improved.
[0113]
　The specific means of high rigidity in the high rigidity region of the intermediate portion 201 will be described later.
[0114]
　Further, the intermediate portion 201, the outer portion of the intermediate portion 201 (e.g., the outer portions of the recess 30 or recess 30) region having a higher tensile strength than the tensile strength of the (high strength region) provided in the rear floor panel 21 it may be. The high strength region, at least, be provided from one end 201a in the vehicle width direction of the intermediate portion 201 toward the other end 201b. The high intensity regions may be provided on all or part of the intermediate portion 201. By increasing the tensile strength of the intermediate portion 201, a portion between the pair of rear frame 4 of the rear floor panel 21, even when the object from the rear of the vehicle has collided, the intermediate portion 201 of the vehicle direction the it is possible to prevent the object from entering.
[0115]
　Further, when the rigidity of the intermediate portion 201, it is possible to extend the possible range of elastic deformation to maintain the rigidity of the intermediate portion 201. Accordingly, the pair of the rear frame 4 is hardly twisted relatively, it is possible to increase the collision safety.
[0116]
　Such rear floor panel 21 including an intermediate portion 201 having a high strength region, for example, obtained by a tailored blank containing relatively high steel sheet portion a tensile strength of a portion corresponding to the intermediate portion 201 for pressing.
[0117]
　Further, the rear frame 4 shown in FIGS. 11 and 13 may not flange is provided. Figure 14 is a sectional view according to another embodiment of the vehicle rear structure in XIII-XIII section line of Figure 11. As shown in FIG. 14, the recess 30 of the flange without the rear frame 4 and the rear floor panel 20, if it is bonded with each other aspects and / or bottom, presence of the flange in the rear frame 4 is not particularly limited.
[0118]
　<< 5. Specific examples of the high rigidity >>
　Next, a first embodiment of the present invention, the rear floor panel 2 of the vehicle rear structure 1 according to the second and third embodiments (10, 11) (20, 21 bottom portion 300 of), when the high-rigidity region to the intermediate portion 301 and intermediate portion 201 is provided, the specific method of high rigidity of the high rigidity region is described. In the following, an example will be described of a specific technique in the case of providing the high-rigidity region to all or part of the bottom portion 300 of the first embodiment of the present invention. Applying such techniques, an intermediate portion 301 according to a second modification of the first embodiment of the present invention, similarly to the intermediate portion 201 of the second bottom portion 300 and the third according to the embodiment of the embodiment possible it is.
[0119]
　Figure 15 is a diagram showing an example of the high rigidity region 310 provided on the bottom surface portion 300 in accordance with an embodiment of the present invention. As shown in FIG. 15, the high rigidity region 310 is provided from one end to the other end in the vehicle width direction of the bottom portion 300. By high rigidity region 310 is provided in this manner, it is possible to suppress the relative twisting of the ends of the bottom portion 300. Then, the relative twisting of the pair of rear frame 4 is also suppressed. Thus, it is possible to absorb more impact during a collision.
[0120]
　Further, as shown in FIG. 15, it may be a plurality of high rigidity region 310 is provided on the bottom surface 300 may be is provided by the high rigidity region 310 in a part of the bottom portion 300. Of course, it may be the high rigidity region 310 is provided on the entire bottom surface portion 300. Such high-rigidity area 310, as shown in FIG. 15, may be provided with a plurality in parallel in the vehicle length direction. Further, a plurality of high rigidity region 310 may be provided so as to cross on the bottom portion 300. In short, the high rigidity region 310, at least a part of the bottom surface portion 300, may be provided so as to be connected from one end to the other end in the vehicle width direction.
[0121]
　High rigidity of the high rigidity region 310 may be implemented by the following means. For example, the thickness of the metal plate in the high rigidity region 310 may be larger than the plate thickness of the portion other than the high rigidity region 310 in the rear floor panel 2. In the present embodiment, the thickness of the metal plate in the rigid region 310 is larger than the thickness of the outer portion of the bottom portion 300 (e.g., the portion other than the bottom portion 300 of the flat portion 5 or spare tire storage portion 3) it may be. Thus, it is possible to increase the rigidity in the high rigidity region 310. Rear floor panel 2 in which the plate thickness of the metal plate includes a relatively large high-rigidity region 310 can be implemented, for example, by tailored blanks or tailor rolled blanks.
[0122]
　In the case where the high rigidity region is provided in the intermediate portion 301 of the second modification of the first embodiment, the thickness of the metal plate in the rigid region is a plate in the vehicle width direction outer side portion of the intermediate portion 301 it may be greater than the thickness. Also, if the high rigidity region is provided on the bottom surface 300 of the second embodiment, the thickness of the metal plate in the high rigidity region may be larger than the thickness of the outer portion of the bottom portion 300. Also, if the high rigidity region is provided in the intermediate portion 201 of the third embodiment, the thickness of the metal plate in the high rigidity region can be larger than the plate thickness of the vehicle width direction outer side portion of the intermediate portion 201 good.
[0123]
　Further, the metal plate in the rigid region 310, the sheet member made of a resin may be bonded. Such sheet members may be joined to one or both sides of the metal plate in the rigid region 310. If the sheet member is bonded to any one side of the metal plate, the sheet member may be joined to either the inside or outside of the vehicle. By bonding the sheet member made of such a resin on a metal plate in the rigid region 310, it is possible to increase the rigidity of the high rigidity region 310.
[0124]
　The resin forming the sheet member is preferably, for example, a foam-curing resin. Further, the resin is more preferably provided with a damping performance. Method of joining the sheet member and the metal plate is not particularly limited. For example, when the resin forming the sheet member is a resin of the foamed curable, by an adhesive force of the resin formed on the surface of the metal plate and the sheet member and the metal plate may be joined.
[0125]
　Further, the metal plate in the rigid region 310, the resin structure may be joined together with the sheet member. Figure 16 is a diagram showing a configuration example of a resin structure 7 and the sheet member 8 according to an embodiment of the present invention. Referring to FIG. 16, resin structure 7 according to this embodiment, the tubular body 71 of a plurality of the same height, the top surface 72 to cover the respective one end portions 71a of the cylinder 71, and the cylindrical body 71 comprising a base portion 73 which connects each of the other end portion 71b to each other. Further, the base portion 73, the sheet member 8 made of a resin or paper is bonded.
[0126]
　By sandwiching such a resin structure 7 by the metal plate and the sheet member 8 of the bottom portion 300 of the rigid region 310, can increase the overall thickness including the metal plate of the bottom portion 300 in the high rigidity region 310 . The high rigidity of the high-rigidity area 310, by performing the resin a small density as compared with the metal plate, can be realized weight reduction per rigidity.
[0127]
　The structure of the resin structure 7 is not limited to the example shown in FIG. 16. For example, the height of the cylindrical body 71, the in-plane direction of the size, pitch, and top surface shape of the 72 and the base 73 (e.g., a circle or honeycomb structures), etc., the high rigidity region resin structure 7 is applied 310 It may appropriately be set in accordance with the required performance and the like in.
[0128]
　Further, resin structure 7 can be joined to one or both sides of the metal plate in the rigid region 310. If resin structure 7 is joined to one side of the metal plate, resin structure 7 may be bonded to either the inside or outside of the vehicle. However, in order to avoid the reduction of the effects of high rigidity due to the damage caused by collision of the object from the outside, the resin structure 7 is preferably bonded to the inside of the vehicle. Further, on one surface of the metal plate in the rigid region 310 is joined resin structure 7 may be joined sheet member on the other side.
[0129]
　Further, the metal plate in the rigid region 310, irregularities may be formed. And such irregularities, for example, a shape constituted by concave or convex portions are formed on the surface of the metal plate. By the uneven shape is formed on the metal plate in the rigid region 310, the proportion of the flat surface (surface on which irregularities are not formed) of the rigid region 310 is reduced. This improves the rigidity of the metal plate in the rigid region 310. Such irregularities may, for example, may be formed by embossing or the like. More specifically, as irregularities, irregularities disclosed in WO 2013/94691 may be applied to the high rigidity region 310.
[0130]
　Further, the metal plate in the rigid region 310, means high rigidity as described above may be applied in combination as appropriate. For example, irregularities are formed by embossing the metal plate in the rigid region 310, and the resin structure and / or sheet member may be joined to the metal plate.
[0131]
　Incidentally, means high rigidity as described above is only an example, the bottom portion 300 or the like, if it is possible to improve the rigidity of the high rigidity region, the technology according to the known high rigidity is on the high-rigidity region It can be applied for.
[0132]
　This completes the description of a specific example of the high rigidity.
[0133]
　<< 6. Specific examples of the junction >>
　Next, the rear floor panel 20 of the vehicle rear structure 10 according to the second embodiment and the third embodiment of the present invention (11) (21) and a rear frame 4, a frame-shaped portion when joined through the joining portion 51 and a side wall and a side wall of the rear frame 4 of the side wall or recess 30, a specific example of the joint will be described. In the following, an example will be described of a specific technique joint portion provided on the side wall and the side wall of the rear frame 4 of the frame-shaped portion 51 of the second embodiment of the present invention. Such techniques, third even joint portion provided on the side walls of the rear frame 4 of the recess 30 according to the embodiment of which is equally applicable to the present invention.
[0134]
　Figure 17 is a cross-sectional view showing an example of a joint 6 according to an embodiment of the present invention. Such cross-sectional view is a view showing a cross section of each member of the portion where the frame-shaped portion 51 according to the second embodiment of the present invention and the rear frame 4 are joined (see FIG. 8). As shown in FIG. 17, the bonded part 6 is a portion for joining an inner surface 41a of the side wall 41 of the outer side surface 52a and the rear frame 4 of the side wall 52 of the frame-shaped portion 51.
[0135]
　Incidentally, the joint 6 shown in FIG. 17 is a portion for joining the outer surface 52a and inner surface 41a illustrates schematically, the actual position of the joint portion 6, the range and magnitude are shown in FIG. 17 not limited to the examples, it varies depending on the bonding manner. For example, the joint 6 shown in FIG. 17 may be a nugget formed between the side wall 52 and the side wall 41 by spot welding. In another example, the position of the joint 6 is formed (vehicle length direction or position in the vehicle height direction), an outer surface 52a and inner surface 41a may be all or a portion of contact with each other. Further, the range of the joint 6, may be a range that penetrates one or both of the side walls 41 of the side wall 52 and the rear frame 4 of the frame-shaped portion 51, contact portion between the side wall 52 and the side wall 41 and its it may be in the vicinity. The size of the joint portion 6 can be appropriately set depending on the position or the like to be bonded unit and formation. Further, a plurality of joint portions for joining the outer surface 52a and inner surface 41a may be formed as a single joint 6.
[0136]
　Joint 6, for example, may be a weld. That is, the joint 6 can be a portion formed by welding. Such welding, laser welding, arc welding, arc spot welding, or a spot welding or the like. Furthermore, such welding can be a hybrid welding combines laser welding and arc welding.
[0137]
　Further, such welds may be formed in a linear shape continuous with bent in the vehicle length direction. Figure 18 is a diagram showing an example of a welding portion 61 formed in a linear shape continuous with bent in the vehicle length direction. As shown in FIG. 18, welds 61 joining the frame-shaped portion 51 and the rear frame 4, continuous in longitudinal direction of the vehicle, or may be formed in a wave that oscillates in the vehicle height direction. This makes it possible to obtain more bonding wire length. Therefore, it is possible to increase the bonding strength between the frame-shaped portion 51 and the rear frame 4.
[0138]
　Additional joint 6, for example, may be a fastening portion. Such fastening part, for example, bolts, may be implemented by a nut or rivet. Thus, the inner surface 41a of the outer side surface 52a and the rear frame 4 of the frame-shaped portion 51 are joined by the fastening. The joining portion 6 may be, for example, an adhesive portion. Such adhesive may, for example, may be implemented by known adhesives such as a resin or the like. Thus, the inner surface 41a of the outer side surface 52a and the rear frame 4 of the frame-shaped portion 51 is joined by adhesion. The joining portion 6 is, for example, may be a crimped portion. Such caulking joint, for example, being in contact with the inner surface 41a of the outer side surface 52a and the rear frame 4 of the frame-shaped portion 51 may be realized by combining the two members connecting by plastic deformation. Further, the caulking joint can be realized by caulking bonding using bonding member such as a rivet.
[0139]
　<< 7. Examples of other reinforcing means >>
　(groove)
　Next, the second embodiment and the rear floor panel 20 (21) and the rear frame of the third vehicle rear portion structure 10 according to the embodiment of (11) of the present invention in bonding of the 4, an example of providing each fitting groove in the frame-shaped portion 51 and the rear frame 4. In the following description, it will be described fitting groove provided in the second side wall and the side wall of the rear frame 4 of the frame-shaped portion 51 of the rear floor panel 20 according to an embodiment of the present invention. Such fitting groove, the third to the side wall and the side wall of the rear frame 4 of the recess 30 according to the embodiment of which is equally applicable to the present invention.
[0140]
　First, a portion of the side wall of the frame-shaped portion 51, a first fitting groove extending in the vehicle height direction may be provided one or more. In this case, the side wall of the rear frame 4, the second fitting groove is provided corresponding to the first groove provided in the frame-shaped portion 51. Then, when the frame-shaped portion 51 and the rear frame 4 are joined, the first groove can be fitted to the second fitting groove. These fitting grooves may be formed, for example, by bending or the like.
[0141]
　Figure 19A is a cross-sectional view showing a first example showing the state of the frame-shaped portion 51 and the rear frame 4 when the first fitting groove 80A is fitted into the second fitting groove 81A. Note that FIG 19A is a view of the horizontal section of the frame-shaped portion 51 and the rear frame 4 from above the vehicle. As shown in FIG. 19A, a part of the side wall 41 and a portion of the rear frame 4 of the side wall 52 of the frame-shaped portion 51, the portion to be bent in the longitudinal direction of the vehicle is provided. Of these, the portion that protrudes to the outside of the side wall 52 and side walls 41, a first groove 80A and a second fitting groove 81A. Since the first groove 80A is fitted into the second fitting groove 81A, the even part of the fitting groove, and the inner side surface 41a of the outer side surface 52a and the rear frame 4 of the frame-shaped portion 51 abuts.
[0142]
　If each of the fitting groove is not provided in the frame-shaped portion 51 and the rear frame 4, when an impact load is applied from the rear of the vehicle relative to the rear floor panel 20, the load transfer from the rear floor panel 20 to the rear frame 4, It takes place only through the joint, such as joint 6. Then, if the load transmitted exceeds the bonding strength, bonding breaking the frame-shaped portion 51 and the rear frame 4 is caused, the transmission and the collision object such as penetration of the impact force to the vehicle inside may occur. Therefore, provided each of the fitting groove in the frame-shaped portion 51 and the rear frame 4, by fitting together, the impact load through each abut each other part of the fitting groove to the rear frame 4 from the rear floor panel 20 It can transmit. Therefore, it is possible to increase the overall bonding strength between the frame-shaped portion 51 and the rear frame 4. Thus, it is possible to improve the collision safety.
[0143]
　Incidentally, the joint 6 shown in FIG. 19A is provided on the outermost in a position of the first groove 80A and a second fitting groove 81A, the position is not limited to any particular joint 6 is provided. The joining portion 6 even when not provided in the side wall of the frame-shaped portion 51 and the rear frame 4, is it possible to provide each of the fitting groove.
[0144]
　The first groove and the second groove shape (shape of the cross section) is not limited to the example shown in FIG. 19A. Figure 19B is a cross-sectional view of a first fitting groove 80B shows a second example of the state of the frame-shaped portion 51 and the rear frame 4 when fitted into the second fitting groove 81B. Note that FIG 19B is a view of the horizontal section of the frame-shaped portion 51 and the rear frame 4 from above the vehicle. As shown in FIG. 19B, the first groove 80B and the second groove 81B, respectively, it may have a U-shaped cross-sectional shape in a plan view. Other shapes of the first groove and second groove may be each groove abut each other, if possible, not particularly limited.
[0145]
　In the example shown in FIGS. 19A and 19B, the first groove and the second groove has a shape in which each side wall of the frame-shaped portion 51 and the rear frame 4 projecting outwardly of the side wall which was, however, the present invention is not limited to such an example. For example, the first groove and the second groove is fitted provided between the portion where each of the side walls of the frame-shaped portion 51 and the rear frame 4 is provided with a portion projecting inward of the side wall and the protruding it may be a groove. Even in such a configuration, occurs effect that transmission of the impact load through a portion fitting groove are in contact with each other person, it is possible to increase the bonding strength.
[0146]
　The length in the vehicle width direction of the first groove and the second groove (i.e., the depth of the grooves in the fitting groove) is the same toward the bottom portion from the opening of the frame-shaped portion 51 and the rear frame 4 it may be. The length in the vehicle width direction of each of the fitting groove may vary over the said bottom portion from the opening. For example, as shown in FIGS. 19A and 19B, when each of said fitting groove protrudes outside the side wall, the length in the vehicle width direction of each of said fitting groove, the bottom of the opening it may decrease over the part. Such a configuration is advantageous in terms of formability.
[0147]
　(Contact member)
　Next, at the junction between the second embodiment and the rear floor panel 20 (21) and the rear frame 4 of the vehicle rear structure 10 according to the third embodiment (11) of the present invention, the frame-shaped portion for example providing the contact member to the inside of the 51 will be described. In the following, a description will be given of the abutting member provided inside of the frame-shaped portion 51 of the rear floor panel 20 according to a second embodiment of the present invention. Such contact member, the third is the embodiment equally applicable to the inner side of the recess 30 according to the embodiment of the present invention.
[0148]
　The inside of the frame-shaped portion 51 abuts the abutting member may be provided to both opposite side walls of the frame-shaped portion 51 (i.e. the inner surfaces of both opposite). That is, such abutment member, the inner side of the frame-shaped portion 51 may be provided so as to connect the side walls of both.
[0149]
　Figure 20A is a diagram showing a first example of the abutting member. As shown in FIG. 20A, the contact member 90A may be provided to fill the space inside the frame-shaped portion 51. In this case, the contact member 90A is provided with respective side walls 52 of the frame-shaped portion 51 abuts.
[0150]
　In the case where the bonded part 6 is provided on the side wall 41 of the side wall 52 and the rear frame 4 of the frame-shaped portion 51, the direction of the rear floor panel 20 is when subjected to impact load, by such a load is a side wall 52 and the side wall 41 away from each other it may be deformed to. Specifically, by such a load, the side walls 52 of the frame-shaped portion 51 which may fall down to the inside of the frame-shaped portion 51. Then, breaking is apt to occur due to peeling mode of joint 6.
[0151]
　Therefore, by providing the contact member 90A to the inside of the frame-shaped portion 51, it is possible to suppress the leaning in the inside of the side wall 52 of the frame-shaped portion 51. Therefore, it is possible to prevent breakage due to separation mode junction 6. Therefore, it is possible to increase the bonding strength between the frame-shaped portion 51 and the rear frame 4.
[0152]
　Note that abutment member may be provided in contact to the side walls of both the opposing frame shaped portion 51. 20B is a diagram showing a second example of the abutting member. As shown in FIG. 20B, may contact member 90B is provided with a connecting part (upper portion of the side wall 52 in FIG. 20B) between the side walls 52 of the frame-shaped portion 51 in cross section perpendicular to the longitudinal direction of the vehicle. Thus, also the force sidewall 52 by the impact load collapses inside the frame-shaped portion 51 acts, it is possible to suppress the leaning by the contact member 90B. The size and the contact position of the contact members inside the frame-shaped portion 51 in cross section perpendicular to the longitudinal direction of the vehicle, the strength of the vehicle rear structure 1 is required, rigid, appropriately according to the weight and manufacturing cost, etc. settings can be.
[0153]
　Also, the installation position of the contact member in the vehicle length direction is not particularly limited. However, in order to more reliably prevent fracture due to peeling mode of the bonded part 6, corresponding to the position where the joint 6 is provided in the vehicle length direction abutting member is preferably provided. The installation position and the installation of the abutment member in the vehicle length direction, the strength of the vehicle rear structure 1 is required, the rigidity can be set appropriately according to the weight and manufacturing cost.
[0154]
　The contact member may be formed, for example, a resin such as foaming and curing the resin. The contact member may for example be formed by a metal strip or metal plate. Further, the contact member may not necessarily be fixed to the inner surface of the side wall 52 of the frame-shaped portion 51. That is, the contact member may not be bonded to the inner surface of the side wall 52, it is sufficient to contact at least a portion of the inner surface of the side wall 52.
[0155]
　Incidentally, a fitting groove and the contact member described above, the recess 30 of the second frame shaped portion 51 and the third according to the embodiment of the embodiment of the present invention, as well as with respect to the rear frame 4, are used at the same time it may be.
[0156]
　<< 8. Conclusion >>
　has been described in detail preferred embodiments of the present invention with reference to the accompanying drawings, the present invention is not limited to such an example. It would be appreciated by those skilled in the relevant field of technology of the present invention, within the scope of the technical idea described in the claims, it is intended to cover various changes and modifications , also such modifications are intended to fall within the technical scope of the present invention.
[0157]
　In the above embodiment has been described with reference to steel as a metal plate forming a vehicle rear structure 1 is not limited to this, also exhibits the effect similar vehicle rear portion structure formed from other metal plate. For example, one or both of the rear floor panel and the rear frame vehicle rear structure molded from an aluminum alloy plate is also, the same effects as the effects shown in the above embodiment.
DESCRIPTION OF SYMBOLS
[0158]
　1, 10, 11 vehicle rear structure
　2,20,21 rear floor panel
　3, 30 recess (spare tire storage
　portion) 4 rear frame
　5,50 flat portion
　6 joining portion
　7 resin structure
　8 sheet member
　side wall 41 rear frame 4
　51 frame-shaped portion
　side wall of the 52 frame-shaped portion 51
　71 cylindrical member
　72 top surface
　73 the base portion
　80A, 80B first groove
　81A, 81B second fitting groove
　90A, 90B contact member
　201, 301 intermediate portion
　300 bottom portion
　310 high rigidity area

The scope of the claims
[Requested item 1]
A pair of rear frame installed in the vehicle length direction,
having a recess formed in a metal plate having a tensile strength of at least the pair of rear frame toward the vehicle rear to the vehicle front, is joined to the pair of rear frame rear floor and the panel, that
　comprises a vehicle rear portion structure.
[Requested item 2]
　The rear floor panel has a pair of flat portions on both ends in the vehicle width direction is joined to the pair of rear frames via the pair of flat portions,
　the recess is provided between the pair of flat portions the vehicle rear portion structure according to claim 1.
[Requested item 3]
　The pair of flat portions has a frame-shaped portion extending in the vehicle length direction,
　at least a portion of the frame-shaped portion of the pair of plane portions is joined to the pair of rear frames, according to claim 2 vehicle rear structure of.
[Requested item 4]
　Wherein the each of the at least a portion of the side wall of the frame-shaped portion and each of the side walls of the pair of rear frames are joined via a joint, the vehicle rear portion structure according to claim 3.
[Requested item 5]
　At least a portion of the side wall of each of the frame-shaped portion is provided with a first fitting groove extending in the vehicle height direction,
　the sidewalls of each of said pair of rear frame, the second corresponding to the first groove fitting groove is provided,
　the first fitting groove is fitted into the second fitting groove, the vehicle rear portion structure according to claim 3 or 4.
[Requested item 6]
　The frame on the inner side of the shaped portion, said frame abuts the abutment member is provided for opposing both sidewalls of the shaped portion, the vehicle rear portion structure according to any one of claims 3-5.
[Requested item 7]
　The recess is a spare tire storage portion, the vehicle rear portion structure according to any one of claims 2-6.
[Requested item 8]
　Wherein the bottom surface of the spare tire storage portion, at least, from one end to the other end in the vehicle width direction of the bottom portion, the high stiffness region having a higher rigidity than the rigidity of the pair of flat portions are provided, according to claim 7 vehicle rear portion structure according to.
[Requested item 9]
　Wherein the bottom portion of the spare tire storage portion, at least, from one end to the other end in the vehicle width direction of the bottom portion, the high strength region is provided with a higher tensile strength than the tensile strength of the pair of flat portions, wherein vehicle rear portion structure according to claim 7 or 8.
[Requested item 10]
　The recess extends in the longitudinal direction of the vehicle, having a plurality of grooves shape which are arranged in parallel in the vehicle width direction, the vehicle rear portion structure according to any one of claims 2-6.
[Requested item 11]
　The recess, said respective provided in the vehicle width direction of both ends of the rear floor panel,
　at least a portion of each of said recesses is joined to a pair of rear frame installed in the vehicle length direction, of claim 1 vehicle rear structure.
[Requested item 12]
　At least a portion of the side wall and the respective side wall of the pair of rear frames are joined via a joint, the vehicle rear portion structure according to claim 11 of each of the recesses.
[Requested item 13]
　At least a portion of the side wall of each of said recesses is provided with a first fitting groove extending in the vehicle height direction,
　the sidewalls of each of the pair of the rear frame, a second fitting corresponding to the first groove grooves are provided,
　the first fitting groove is fitted into the second fitting groove, the vehicle rear portion structure according to claim 11 or 12.
[Requested item 14]
　The inner side of the recess, abuts the abutting member is provided to both opposing side walls of the recess, the vehicle rear portion structure according to any one of claims 11 to 13.
[Requested item 15]
　Wherein the intermediate portion positioned between each of the recesses in the vehicle width direction in the rear floor panel, from one end to the other end in the vehicle width direction of the intermediate portion, in the vehicle width direction outer side portion of the intermediate portion of the rear floor panel high rigidity region having a higher rigidity than the rigidity are provided, the vehicle rear portion structure according to any one of claims 10-14.
[Requested item 16]
　Wherein the intermediate portion positioned between each of the recesses in the vehicle width direction in the rear floor panel, from one end to the other end in the vehicle width direction of the intermediate portion, in the vehicle width direction outer side portion of the intermediate portion of the rear floor panel high strength region is provided with a higher tensile strength than the tensile strength of the vehicle rear portion structure according to any one of claims 10-15.
[Requested item 17]
　The high thickness of the metal plate in the rigid region, the greater than the thickness of the metal plate in a portion other than the high-rigidity region in the rear floor panel, a vehicle rear portion structure according to claim 8 or 15.
[Requested item 18]
　Vehicle rear portion structure according to said high the in rigidity region on the metal plate, sheet member made of a resin is bonded, claims 8, 15 or 17.
[Requested item 19]
　Wherein the said metal plate in the high-rigidity region, connects the cylinder of a plurality of the same height, the top surface respectively cover one end portion of the cylindrical body, and the respective other ends of the cylindrical body resin structure comprising a base portion, said being bonded via the top surface,
　the base of the resin structure is a sheet member made of a resin or paper are bonded, claims 8,15,17 or vehicle rear portion structure according to 18.
[Requested item 20]
　Vehicle rear portion structure according to the high the metal plate in the rigid region has an uneven shape, claim 8,15,17,18 or 19.
[Requested item 21]
　The joint is welded portion, the fastening portion is at least one of the bonding portion or the caulking joints, the vehicle rear portion structure according to claim 4 or 12.
[Requested item 22]
　The weld is formed in a linear shape continuous with bent in the vehicle length direction, the vehicle rear portion structure according to claim 21.
[Requested item 23]
　The weld is formed by laser welding and / or arc welding, the vehicle rear portion structure according to claim 21 or 22.
[Requested item 24]
　The weld is formed by spot welding or arc spot welding, the vehicle rear portion structure according to claim 21.
[Requested item 25]
　The abutting member is formed of resin or metal, the vehicle rear portion structure according to claim 6 or 14.
[Requested item 26]
　It said recess is provided from the vehicle length direction rear end of the rear floor panel, a vehicle rear portion structure according to any one of claims 1 to 25.
[Requested item 27]
　Tensile strength of the recess is greater than or equal to 980 MPa, the vehicle rear portion structure according to any one of claims 1 to 26.
[Requested item 28]
　In the vehicle length direction, the rear end of the recess is located further rearward than the rear end of the pair of rear frame, the vehicle rear portion structure according to any one of claims 1-27.
[Requested item 29]
　The rear floor panel is a press-molded product obtained by press molding a sheet of the work plate, the vehicle rear portion structure according to any one of claims 1 to 28.
[Requested item 30]
　Wherein one of the work plate includes a first metal plate portion corresponding to the portion including at least the concave portion, a second metal plate corresponding to the sites contained the said rear floor panel other than the site containing at least said recess is constituted by a part,
　the tensile strength per unit width of the first metal plate, said second higher than the tensile strength per unit width of the metal plate, the vehicle rear portion structure according to claim 29.