Vehicle back door structure

Abstract

To provide a back door structure of a vehicle that can reduce noise in a vehicle interior by suppressing vibration of an outer panel while being reduced in weight and cost.SOLUTION: A back door comprises an outer panel 10 and an inner panel 11. The inner panel 11 has a transverse skeleton part 11g, vertical skeleton parts 11e and 11f, merging parts 11h and 11i, and connection parts 11j-11l. The connection part 11j extends only from one end part at an opening part SP1 side in a width direction of the transverse skeleton part 11g, and the connection part 11k extends only from one end part at an opening part SP2 side in the width direction of the vertical skeleton part 11e. The connection part 11l extends only from one end part at an opening part SP3 side in the width direction of the vertical skeleton part 11f. The connection parts 11j-11l respectively are connected to the outer panel 10. The merging parts 11h and 11i are formed having torsional stiffness higher than those of the transverse skeleton part 11g and the vertical skeleton parts 11e and 11f.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a back door structure for a vehicle. [Background technology]

[0002] Vehicles such as wagons, including sport utility vehicles (SUVs), have an opening at the rear of the vehicle body and are equipped with a back door to open and close the opening. As vehicles become larger, the length and width of the back door become larger.

[0003] However, it is necessary to suppress vibrations of the back door when the vehicle is traveling. This is because if the back door vibrates while the vehicle is traveling, it will cause noise in the passenger compartment. Patent Document 1 discloses a structure for suppressing such vibrations of the back door when the vehicle is traveling.

[0004] In the tailgate structure disclosed in Patent Document 1, the tailgate is configured by connecting an outer panel and an inner panel. The inner panel has an opening in its lower half, below the windshield opening, and includes a middle edge, lower side edges, and a bottom edge that surround the opening. Three joints extend from the bottom edge of the middle edge of the inner panel, and one joint extends from each of the left and right lower side edges. These joints are joined to the outer panel. In addition, a reinforcing member that reinforces the latch opening is attached to the bottom edge, and the reinforcing member also secures the inner panel to the outer panel.

[0005] Patent Document 1 states that by connecting the inner panel and the outer panel with five joints and one reinforcing member, it is possible to suppress vibration of the back door when the vehicle is traveling. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-148464 Summary of the Invention [Problem to be solved by the invention]

[0007] Lightweight and cost-effective vehicles are in demand, and reducing the weight and cost of tailgates is also an issue. Measures being considered to reduce the weight and cost of tailgates include narrowing the width of the inner panel frame and eliminating the reinforcing members mentioned above.

[0008] However, as a result of investigations by the present inventors, it was discovered that if the skeleton portion (middle edge portion, bottom edge portion, etc.) of the inner panel is narrowed and the reinforcing member is eliminated in the tailgate structure disclosed in Patent Document 1, a problem occurs in which vibrations input from the outer panel cause the skeleton portion of the inner panel to twist around an axis extending in the longitudinal direction of the skeleton portion. When the skeleton portion of the inner panel twists as described above, it becomes difficult to suppress membrane surface resonance of the outer panel, and so-called muffled noise occurs inside the vehicle cabin.

[0009] In addition, in order to suppress twisting of the skeleton of the inner panel, it is possible to widen the width of the skeleton or connect it to the outer panel on both sides in the width direction, but these would be contrary to the goal of reducing the weight and cost of the tailgate.

[0010] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle tailgate structure that can reduce noise in the passenger compartment by suppressing vibration of the outer panel while achieving weight reduction and cost reduction. [Means for solving the problem]

[0011] A vehicle back door structure according to one aspect of the present invention is a structure for a vehicle back door having a window opening to which a windshield is attached, and includes an outer panel, an inner panel, and a connecting portion. The outer panel is a panel that constitutes the outside of the back door of the vehicle. The inner panel is a panel that constitutes the inside of the back door of the vehicle. The connecting portion connects the outer panel and the inner panel.

[0012] The inner panel in this embodiment has a first opening, a second opening, a third opening, a fourth opening, a first vertical skeleton portion, a second vertical skeleton portion, a horizontal skeleton portion, a first junction portion, and a second junction portion. The first opening is an opening provided above the lower edge of the inner panel in a portion below the window opening. The second opening is an opening provided between the first opening and the window opening. The third opening is an opening provided between the first opening and the second opening and the right edge of the inner panel. The fourth opening is an opening provided between the first opening and the second opening and the left edge of the inner panel. The first vertical skeleton portion is a skeleton portion provided to extend in the up-down direction (vertical direction) between the first opening, the second opening, and the third opening. The second vertical skeleton portion is a skeleton portion provided to extend in the up-down direction (vertical direction) between the first opening, the second opening, and the fourth opening. The horizontal skeleton portion is a skeleton portion provided to extend in the left-right direction (horizontal direction) between the first opening and the second opening. The first joining portion is a portion provided at the joining point between the horizontal skeleton portion and the first vertical skeleton portion. The second joining portion is a portion provided at the joining point between the horizontal skeleton portion and the second vertical skeleton portion.

[0013] In this aspect, the connecting portion connects at least one of the horizontal frame portion, the first vertical frame portion, and the second vertical frame portion to the outer panel, and connects only one widthwise end portion of the at least one frame portion to the outer panel. The first junction portion and the second junction portion are each formed with a torsional rigidity higher than that of the horizontal frame portion, the first vertical frame portion, and the second vertical frame portion. In addition, in this aspect, when the upper part of the first vertical skeleton part is defined as the first upper part and the lower part is defined as the first lower part, with the first junction as the boundary, the angle of the first upper part with respect to the axis along the vertical direction of the tailgate is formed to be larger than that of the first lower part, which is located lower than the first junction, and the first junction is located at the junction between the first upper part and the first lower part. In addition, in this aspect, when the second vertical skeleton portion has an upper portion as the second upper portion and a lower portion as the second lower portion, with the second junction portion as the boundary, the angle of the second upper portion relative to the axis along the vertical direction of the tailgate is formed to be larger than that of the second lower portion, which is located lower than the second junction, and the second junction is arranged so that it is located at the junction between the second upper portion and the second lower portion. In addition, in this aspect, the first junction portion is formed to have an expanding shape in a planar view so that the lower edge is gradually positioned lower as it moves from the side of the horizontal skeleton portion to the side of the first vertical skeleton portion. In addition, in this aspect, the second junction portion is formed to have an expanding shape in a planar view so that the lower edge is positioned lower as it moves from the side of the horizontal skeleton portion to the side of the second vertical skeleton portion. Furthermore, in this embodiment, the first vertical skeleton, the second vertical skeleton, and the horizontal skeleton are arranged in the vertical direction of the vehicle so that the lower part of the first upper part, the lower part of the second upper part, and the left and right ends of the horizontal skeleton are at height positions that overlap each other.

[0014] In the vehicle tailgate structure according to the above aspect, the connecting portion connecting the at least one skeletal portion to the outer panel connects only one widthwise end portion of the at least one skeletal portion to the outer panel, so that the number of connecting portions can be reduced compared to a configuration in which both widthwise ends of the skeletal portion are connected to the outer panel, thereby enabling weight reduction and cost reduction.

[0015] When connecting only one widthwise end of at least one skeletal part to the outer panel as described above, vibrations input from the outer panel will cause the skeletal part to twist around the axis extending in the longitudinal direction. However, in the vehicle tailgate structure according to the above embodiment, the first junction and second junction are formed with higher torsional rigidity than the horizontal skeletal part, the first vertical skeletal part, and the second vertical skeletal part, so that twisting of the at least one skeletal part in the inner panel is suppressed. Furthermore, in the vehicle back door structure according to the above aspect, the first upper portion of the first vertical frame portion is angled so as to open outward the higher it goes above the first lower portion, and the second upper portion of the second vertical frame portion is angled so as to open outward the higher it goes above the second lower portion, so that the vehicle width direction dimensions of the first junction portion and the second junction portion can be made larger than when the first vertical frame portion and the second vertical frame portion are each formed to extend linearly. Therefore, the vehicle back door structure according to the above aspect is advantageous in ensuring high torsional rigidity of each of the first junction portion and the second junction portion, and is even more advantageous in suppressing vibration of the outer panel by suppressing torsion of the at least one frame portion while achieving weight reduction and cost reduction, and reducing noise in the vehicle cabin.

[0016] Therefore, the vehicle tailgate structure according to the above aspect can reduce weight and costs while suppressing torsion of at least one of the skeletal parts, thereby suppressing vibration of the outer panel and reducing noise in the vehicle cabin.

[0017] In the vehicle tailgate structure relating to the above-mentioned aspect, each of the first merging portion and the second merging portion may be formed to have a larger vertical dimension than the horizontal skeleton portion, and a larger left-right dimension (vehicle width dimension) than each of the first vertical skeleton portion and the second vertical skeleton portion.

[0018] In the vehicle back door structure according to the above aspect, the first junction portion and the second junction portion each have a larger vertical dimension than the horizontal skeleton portion and a larger left-right dimension than the first vertical skeleton portion and the second vertical skeleton portion, respectively, so that the polar moment of inertia of the first junction portion and the second junction portion can be made higher than that of the horizontal skeleton portion and the first vertical skeleton portion and the second vertical skeleton portion. As a result, the vehicle back door structure according to the above aspect is advantageous in reducing noise in the vehicle cabin by suppressing vibration of the outer panel by suppressing torsion of at least one skeleton portion while achieving weight reduction and cost reduction.

[0019] In the vehicle back door structure according to the above aspect, The width in the left-right direction gradually increases from the bottom to the top, and Front view In the first joining portion, the center line in the left-right direction is approximately symmetrical. Approximately triangular shape The second junction has a width in the left-right direction that gradually increases from the bottom to the top, and has a substantially triangular shape that is substantially symmetrical with respect to the center line of the left and right sides of the second junction when viewed from the front. It may also be possible to use the following.

[0020] In the vehicle tailgate structure according to the above aspect, the first junction and the second junction each have an approximately triangular shape in a plan view, which is advantageous in distributing the load input from the outer panel through the at least one skeletal portion.

[0021] The term "substantially triangular" as used above includes cases where each corner is arc-shaped or cut in a straight line.

[0022] In the vehicle back door structure according to the above aspect, the connecting portion may have a first connecting portion, a second connecting portion, and a third connecting portion. The first connecting portion may be a connecting portion that connects only one widthwise end portion of the horizontal frame portion to the outer panel. The second connecting portion may be a connecting portion that connects only one widthwise end portion of the first vertical frame portion to the outer panel. The third connecting portion may be a connecting portion that connects only one widthwise end portion of the second vertical frame portion to the outer panel.

[0023] In the vehicle tailgate structure according to the above aspect, the connecting portion has a first connecting portion, a second connecting portion, and a third connecting portion, and therefore is more effective in suppressing membrane surface resonance of the outer panel with the inner panel than when the outer panel and inner panel are connected with a single connecting portion.

[0024] In the vehicle back door structure according to the above aspect, the first connecting portion, the second connecting portion, and the third connecting portion may be provided at positions that overlap one another in a side view from the left-right direction.

[0025] In the vehicle tailgate structure according to the above aspect, the first connecting portion, the second connecting portion, and the third connecting portion are arranged in positions that overlap each other when viewed from the left and right, which is advantageous in preventing the resonance mode of the outer panel from becoming complex and in suppressing membrane surface resonance of the outer panel by the inner panel.

[0026] In the vehicle tailgate structure according to the above aspect, the first connecting portion may have a connecting wall portion that connects the outer panel and the inner panel in the fore-and-aft direction, and the connecting wall portion may have a bead formed to extend in the fore-and-aft direction.

[0027] In the vehicle back door structure according to the above aspect, the bead is provided on at least the connecting wall portion in the first connecting portion, so that high rigidity of the connecting wall portion can be ensured against vibration input from the outer panel to the inner panel, which is more effective in suppressing membrane surface resonance of the outer panel with the inner panel.

[0028] In the vehicle tailgate structure relating to the above aspect, the first connecting portion may be formed integrally with the horizontal skeleton portion, the second connecting portion may be formed integrally with the first vertical skeleton portion, and the third connecting portion may be formed integrally with the second vertical skeleton portion.

[0029] In the vehicle back door structure according to the above aspect, the first connecting portion is integrally formed with the horizontal frame portion, the second connecting portion is integrally formed with the first vertical frame portion, and the third connecting portion is integrally formed with the second vertical frame portion, so the number of parts can be reduced. Furthermore, since there is no need to connect the first connecting portion to the horizontal frame portion, the second connecting portion to the first vertical frame portion, or the third connecting portion to the second vertical frame portion, the number of manufacturing steps can be reduced. Therefore, the vehicle back door structure according to the above aspect is further advantageous in terms of weight reduction and cost reduction.

[0030] In the vehicle tailgate structure relating to the above-mentioned aspect, the first connecting portion may connect only one end portion of the horizontal skeleton portion on the side of the first opening in the width direction to the outer panel, the second connecting portion may connect only one end portion of the first vertical skeleton portion on the side of the third opening in the width direction to the outer panel, and the third connecting portion may connect only one end portion of the second vertical skeleton portion on the side of the fourth opening in the width direction to the outer panel.

[0031] In the vehicle back door structure according to the above aspect, the first connecting portion is disposed on the side of the first opening in the width direction of the horizontal frame portion, the second connecting portion is disposed on the side of the third opening in the width direction of the first vertical frame portion, and the third connecting portion is disposed on the side of the fourth opening in the width direction of the second vertical frame portion, so that the outer panel can be connected to the inner panel by the first connecting portion, the second connecting portion, and the third connecting portion at the expected license plate attachment position on the outer panel and its surrounding area. Therefore, by connecting the outer panel to the inner panel at the expected license plate attachment position where membrane resonance is likely to occur on the outer panel, it is even more advantageous in suppressing membrane resonance. [Effects of the Invention]

[0034] The vehicle back door structure according to each of the above aspects can reduce noise inside the vehicle cabin by suppressing vibration of the outer panel while achieving weight reduction and cost reduction. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 2 is a rear view of the back door according to the embodiment, as seen from the rear of the vehicle. [Figure 2] FIG. 2 is a front view of the back door as seen from the front of the vehicle. [Figure 3] FIG. 3 is an enlarged view showing a portion A in FIG. 2. [Figure 4] FIG. 2 is a perspective view showing the structure of a central connecting portion. [Figure 5] 10 is a schematic diagram for explaining the positional relationship between a horizontal skeleton portion, a vertical skeleton portion, and a junction portion. FIG. [Figure 6] 10 is a schematic diagram for explaining the positional relationship between a horizontal skeleton portion, a vertical skeleton portion, and a junction portion in a back door according to a modified example. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely illustrative of the present invention, and the present invention is not limited to the following embodiments except for the essential configuration.

[0037] [Embodiment] 1. Overall structure of Backdoor 1 The overall configuration of a back door 1 of a vehicle according to this embodiment will be described with reference to FIGS. 1 and 2. In this specification, directions are indicated based on the vehicle to which the back door 1 is attached. Specifically, the upper side of the vehicle is designated "UP," the lower side of the vehicle is designated "LO," the left side of the vehicle is designated "LH," and the right side of the vehicle is designated "RH." The directions in the back door 1 are based on the back door 1 when the rear opening of the vehicle is closed.

[0038] As shown in Figures 1 and 2, the tailgate 1 has a window opening 1a in the upper half of which a windshield is attached. The tailgate 1 includes an outer panel 10 and an inner panel 11. The outer panel 10 is a panel that forms the outside of the tailgate 1. The inner panel 11 is a panel that forms the inside of the outer panel 10 of the tailgate 1.

[0039] 2, the back panel 1 has three connecting portions 11j to 11l. In this embodiment, the three connecting portions 11j to 11l are formed integrally with the inner panel 11.

[0040] As shown in Figure 1, an area (plate mounting area) 1b where a license plate is expected to be mounted is provided in the lower part of the lower half of the back door 1. The plate mounting area 1b is specified taking into consideration all destinations of vehicles to which the back door 1 is applicable.

[0041] As shown in Fig. 2, four openings SP1 to SP4 are provided in the inner panel 11. The opening (first opening) SP1 is located in the center of the tailgate 1 in the vehicle width direction (left-right direction) and is provided spaced above the lower edge of the inner panel 11. The opening (second opening) SP4 is provided between the opening SP1 and the window opening 1a in the up-down direction of the tailgate 1 and spaced apart from both the opening SP1 and the window opening 1a. The horizontal width (width in the left-right direction) of the opening SP4 is set wider than that of the opening SP1.

[0042] The opening (third opening) SP2 is provided between the openings SP1 and SP4 and the right edge of the inner panel 11, and is spaced apart from the openings SP1 and SP4 and the right edge of the inner panel 11. The opening SP2 has a generally triangular shape with rounded corners in a front view from the front of the vehicle. The opening (fourth opening) SP3 is provided between the openings SP1 and SP4 and the left edge of the inner panel 11, and is spaced apart from the openings SP1 and SP4 and the left edge of the inner panel 11. The opening SP3 has a generally triangular shape with rounded corners that is symmetrical to the opening SP2 in a front view from the front of the vehicle.

[0043] As shown in FIG. 2, the inner panel 11 has peripheral skeletons 11a-11d, vertical skeletons 11e and 11f, and a horizontal skeleton 11g. Of the peripheral skeletons 11a-11d, the lower peripheral skeleton 11a extends in the left-right direction between the openings SP1 and SP2, SP3 and the lower edge of the inner panel 11. The side peripheral skeleton 11b extends in the up-down direction between the opening SP3 and the left edge of the inner panel 11. The lower peripheral skeleton 11a and the side peripheral skeleton 11b are continuous with each other at their butt joints. The side peripheral skeleton 11c is a skeleton that extends in the up-down direction between the opening SP2 and the right edge of the inner panel 11. The lower peripheral skeleton 11a and the side peripheral skeleton 11c are continuous with each other at their butt joints. The upper peripheral skeleton 11d is a skeleton extending in the left-right direction between the opening SP4 and the openings SP2 and SP3 and the window opening 1a. The upper peripheral skeleton 11d is continuous with the side peripheral skeleton 11b and the side peripheral skeleton 11c at their butt joints.

[0044] The vertical skeleton portion (first vertical skeleton portion) 11e is a skeleton portion extending in the vertical direction between the openings SP1 and SP4 and the openings SP2. The vertical skeleton portion 11e is continuous at its lower end with the lower peripheral skeleton portion 11a and continuous at its upper end with both the upper peripheral skeleton portion 11d and the side peripheral skeleton portion 11c. The vertical skeleton portion (second vertical skeleton portion) 11f is a skeleton portion extending in the vertical direction between the openings SP1 and SP4 and the openings SP3. The vertical skeleton portion 11f is continuous at its lower end with the lower peripheral skeleton portion 11a and continuous at its upper end with both the upper peripheral skeleton portion 11d and the side peripheral skeleton portion 11b.

[0045] The horizontal skeleton 11g is a skeleton extending in the left-right direction between the openings SP1 and SP4. The vertical skeleton 11e and the vertical skeleton 11f are connected to the horizontal skeleton 11g at their butt joints.

[0046] Of the three connecting portions 11j-11l, the central connecting portion 11j extends from only one end portion of the horizontal frame portion 11g on the opening SP1 side in the width direction, extends toward the outer panel 10 arranged on the vehicle rear side (toward the back of the paper in FIG. 2), and is connected at its end portion to the outer panel 10. The side connecting portion 11k extends from only one end portion of the vertical frame portion 11e on the opening SP2 side in the width direction, extends toward the outer panel 10 arranged on the vehicle rear side (toward the back of the paper in FIG. 2), and is connected at its end portion to the outer panel 10. The side connecting portion 11l extends from only one end portion of the vertical frame portion 11f on the opening SP3 side in the width direction, extends toward the outer panel 10 arranged on the vehicle rear side (toward the back of the paper in FIG. 2), and is connected at its end portion to the outer panel 10.

[0047] In addition, when the plate mounting area 1b of the tailgate 1 is shown in Figure 2, in the vertical direction of the tailgate 1, the connecting portions 11j to 11l are arranged so as to overlap each other within the area that includes the plate mounting area 1b when viewed from the left and right.

[0048] 2, the inner panel 11 has two junctions 11h and 11i. The junction (first junction) 11h is located where the right end of the horizontal skeleton 11g joins the longitudinally intermediate portion of the vertical skeleton 11e, and is continuous with both the horizontal skeleton 11g and the vertical skeleton 11e. The junction (second junction) 11i is located where the left end of the horizontal skeleton 11g joins the longitudinally intermediate portion of the vertical skeleton 11f, and is continuous with both the horizontal skeleton 11g and the vertical skeleton 11f.

[0049] In this embodiment, the confluence portion 11h and the confluence portion 11i are formed to have bilaterally symmetrical shapes.

[0050] 2. Detailed structure of the joining portions 11h, 11i and their surrounding areas in the inner panel 11 The detailed structure of the joining portions 11h and 11i of the inner panel 11 and their surrounding areas will be described with reference to FIG.

[0051] 3, the vertical skeleton 11e is provided by vertically inserting through the junction 11h, and the vertical skeleton 11f is provided by vertically inserting through the junction 11i. In this embodiment, the vertical skeleton 11e is provided so that a lower portion (first lower portion) 11e1, which is a portion below the junction 11h, and an upper portion (first upper portion) 11e2, which is a portion above the junction 11h, extend at different angles. Specifically, when the center line of the lower portion 11e1 is Le1 and the center line of the upper portion 11e2 is Le2, the angles θ1 and θ2 formed by the lower portion 11e1 and the upper portion 11e2 with respect to reference lines Lv1 and Lv2 extending along the vertical direction of the back door 1 are set to satisfy the following relationship: θ2>θ1 (Equation 1) Although detailed illustration is omitted, the left vertical skeleton 11f also has a lower part (second lower part) 11f1 located below the junction 11i and an upper part (second upper part) 11f2 located above the junction 11i, which are provided so that their extension angles are different. The vertical skeleton 11e and the vertical skeleton 11f are formed in a symmetrical relationship.

[0052] Confluence 11h is provided in an area surrounded by openings SP1, SP2, and SP4, and confluence 11i is provided in an area surrounded by openings SP1, SP3, and SP4. Therefore, confluence 11h and 11i each have a substantially triangular shape whose width in the left-right direction gradually increases from bottom to top. While confluence 11h and 11i are shown in FIG. 3 as triangular shapes with rounded corners, they may also be defined as triangular shapes with straight cut corners (more precisely, hexagonal shapes).

[0053] As shown in FIG. 3, horizontal skeleton 11g, upper portion 11e2 of vertical skeleton 11e, and upper portion 11f2 of vertical skeleton 11f are continuous with each other at junctions 11h and 11i. Therefore, when these skeletons (horizontal skeleton 11g, upper portion 11e2 of vertical skeleton 11e, and upper portion 11f of vertical skeleton 11f) are viewed as a whole, they can be regarded as a single skeleton extending in the left-right direction. In this embodiment, the extension of central connector 11j from horizontal skeleton 11g, the extension of side connector 11k from upper portion 11e2 of vertical skeleton 11e, and the extension of side connector 11l from upper portion 11f2 of vertical skeleton 11f are aligned at one end of each skeleton (horizontal skeleton 11g, upper portion 11e2 of vertical skeleton 11e, and upper portion 11f2 of vertical skeleton 11f) in the vertical width direction. That is, in this embodiment, the central connecting portion 11j connects the lower end portion in the vertical width direction of the horizontal skeleton portion 11g to the outer panel 10, the side connecting portion 11k connects the lower end portion in the vertical width direction of the upper portion 11e2 of the vertical skeleton portion 11e to the outer panel 10, and the side connecting portion 11l connects the lower end portion in the vertical width direction of the upper portion 11f2 of the vertical skeleton portion 11f to the outer panel 10.

[0054] 3. Structure of central connecting part 11j The structure of the central connecting portion 11j extending from one end of the horizontal frame portion 11g will be described with reference to FIG.

[0055] 4, the central connecting portion 11j has an outer joint portion 11j1, an inner bent portion 11j2, and a standing wall portion 11j3 that are continuously formed. The outer joint portion 11j1 is a portion that is joined to the outer panel 10. The outer joint portion 11j1 and the outer panel 10 are joined by, for example, spot welding or an adhesive.

[0056] The inner bent portion 11j2 is a portion with an L-shaped cross section that extends from one end of the horizontal frame portion 11g in the width direction and is bent toward the outer panel 10. The standing wall portion 11j3 is a wall portion that connects the outer joint portion 11j1 and the inner bent portion 11j2, and is formed to extend in the front-rear direction and the vehicle width direction of the vehicle.

[0057] 4, a plurality of beads 11j4 are formed on the upright wall portion 11j3 of the central connecting portion 11j. The plurality of beads 11j4 are formed so as to extend in the front-rear direction and to be aligned in the left-right direction (vehicle width direction).

[0058] 4. Supplementary information about the joining parts 11h and 11i of the inner panel 11 The joining portions 11h and 11i of the inner panel 11 in this embodiment will be further explained with reference to Fig. 5. Fig. 5 is a schematic diagram showing the joining portion 11h and its surrounding area. In the following explanation, the explanation of the joining portion 11i will be omitted, but it is the same as the joining portion 11h.

[0059] As shown in Fig. 5, the joining portion 11h where the horizontal skeleton portion 11g and the vertical skeleton portion 11e join has an arc edge portion Lh1 that curves in an arc shape on the side of the opening SP1. Note that, although Fig. 5 shows the arc edge portion Lh1 as having an arc shape with its center on the side of the opening SP1, it does not necessarily have to be an arc shape.

[0060] The point of contact between the end of the vertical skeleton 11e on the opening SP1 side in the width direction and the arc edge Lh1 is designated as P1, and the point of contact between the end of the horizontal skeleton 11g on the opening SP1 side in the width direction and the arc edge Lh1 is designated as P2. An imaginary line L1 extending in the width direction of the vertical skeleton 11e is drawn from the point of contact P1, and an imaginary line L2 extending in the width direction of the horizontal skeleton 11g is drawn from the point of contact P2. In this case, the portion above the imaginary line L1 (the portion indicated by arrow B1) and to the right of the imaginary line L2 (the portion indicated by arrow B2) is defined as the junction 11h.

[0061] Although the above description omits the definition of the boundaries between the upper portions 11e2, 11f2 of the vertical skeleton portions 11e, 11f and the joining portions 11h, 11i, these boundaries can be defined in the same manner as shown by arrows B1, B2 in FIG.

[0062] 5.Effects In the vehicle back door 1 of this embodiment, the connecting portions 11j to 11l that connect each of the skeletal portions 11e to 11g of the inner panel 11 to the outer panel 10 connect only one widthwise end portion of each of the skeletal portions 11e to 11g to the outer panel 10, so the number of connecting portions 11j to 11l can be reduced compared to a configuration in which both widthwise ends of each of the skeletal portions 11e to 11g are connected to the outer panel 10, thereby achieving weight reduction and cost reduction.

[0063] Furthermore, in the vehicle back door 1 of this embodiment, only one widthwise end of each of the skeletal members 11e to 11g is connected to the outer panel 10, so that vibrations input from the outer panel 10 will cause each of the skeletal members 11e to 11g to twist around an axis extending in the longitudinal direction. However, the inner panel 11 of this embodiment has junctions 11h, 11i, which are formed with higher torsional rigidity than the horizontal skeletal member 11g and the vertical skeletal members 11e, 11f, so that twisting of each of the skeletal members 11e to 11g in the inner panel 11 is suppressed.

[0064] Therefore, the vehicle back door 1 of this embodiment can reduce weight and costs while suppressing torsion in each of the skeletal portions 11e to 11g, thereby suppressing vibration of the outer panel 10 and reducing noise in the vehicle cabin.

[0065] Furthermore, in the vehicle back door 1 according to this embodiment, each of the junction portions 11h, 11i is formed to have a larger vertical dimension than the horizontal skeleton portion 11g and a larger left-right dimension (vehicle width direction dimension) than each of the vertical skeleton portions 11e, 11f, so that the polar moment of inertia of each of the junction portions 11h, 11i can be made higher than those of the horizontal skeleton portion 11g and the vertical skeleton portions 11e, 11f. As a result, the vehicle back door 1 according to this embodiment is advantageous in reducing vibration of the outer panel 10 by suppressing twisting of the skeleton portions 11e-11g while achieving weight reduction and cost reduction, and in reducing noise in the vehicle cabin.

[0066] Furthermore, in the vehicle back door 1 according to this embodiment, each of the junctions 11h, 11i has an approximately triangular shape (a triangular shape with rounded corners) in a plan view, so that the load input from the outer panel 10 through each of the skeletal portions 11e to 11g can be effectively distributed at the junctions 11h, 11i.

[0067] Furthermore, the vehicle back door 1 of this embodiment has connecting portions 11j to 11l, which include a central connecting portion 11j and two side connecting portions 11k, 11l, and therefore the membrane surface resonance of the outer panel 10 can be more effectively suppressed by the inner panel 11 compared to when the outer panel 10 and the inner panel 11 are connected by a single connecting portion.

[0068] Furthermore, in the vehicle tailgate 1 of this embodiment, the central connecting portion 11j and the two side connecting portions 11k, 11l are arranged in positions that overlap each other in the vertical direction, so that the membrane surface resonance of the outer panel 10 can be effectively suppressed by the inner panel 11 without complicating the resonance mode of the outer panel 10.

[0069] Furthermore, in the vehicle back door 1 according to this embodiment, the bead 11j4 is provided on the standing wall portion (connecting wall portion) 11j3 of the central connecting portion 11j, so that high rigidity of the standing wall portion 11j3 can be ensured against vibrations input from the outer panel 10 to the inner panel 11. Therefore, the membrane surface resonance of the outer panel 10 can be more effectively suppressed by the inner panel 11.

[0070] Furthermore, in the vehicle back door 1 according to this embodiment, the central connecting portion 11j is integrally formed with the horizontal frame portion 11g, the side connecting portion 11k is integrally formed with the vertical frame portion 11e, and the side connecting portion 11l is integrally formed with the vertical frame portion 11f, thereby reducing the number of parts. Furthermore, since there is no need to connect the central connecting portion 11j with the horizontal frame portion 11g, the side connecting portion 11k with the vertical frame portion 11e, or the side connecting portion 11l with the vertical frame portion 11f, the number of manufacturing steps can be reduced. Therefore, the vehicle back door 1 according to this embodiment is further advantageous in terms of weight reduction and cost reduction.

[0071] Furthermore, in the vehicle back door 1 according to this embodiment, the central connecting portion 11j is disposed at one end of the horizontal frame portion 11g on the side of the opening SP1 in the width direction, the side connecting portion 11k is disposed at one end of the vertical frame portion 11e on the side of the opening SP2 in the width direction, and the side connecting portion 11l is disposed at one end of the vertical frame portion 11f on the side of the opening SP3 in the width direction, so that the plate mounting area 1b (the expected position for attaching a license plate) of the back door 1 and the area nearby can be connected to the inner panel 11 by the connecting portions 11j-11l. Therefore, by connecting the outer panel 10 to the inner panel 11 in the plate mounting area 1b, where membrane resonance is likely to occur, it is even more advantageous to suppress membrane resonance.

[0072] Furthermore, in the vehicle back door 1 according to this embodiment, the angle θ2 is set so that the upper portion 11e2 of the vertical skeleton 11e opens more outwardly as it goes higher than the lower portion 11e1, and the upper portion 11f2 of the vertical skeleton 11f similarly opens more outward as it goes higher than the lower portion 11f1. Therefore, the left-right dimension (vehicle width dimension) of each of the junctions 11h and 11i can be made larger than when each of the vertical skeletons 11e and 11f is formed to extend linearly. Therefore, the vehicle back door 1 according to this embodiment is advantageous in ensuring high torsional rigidity of each of the junctions 11h and 11i, and is even more advantageous in suppressing vibration of the outer panel 10 by suppressing torsion of the skeletons 11e to 11g while achieving weight reduction and cost reduction.

[0073] As described above, the vehicle back door 1 according to this embodiment can reduce noise in the vehicle cabin by suppressing vibration of the outer panel 10 while achieving weight reduction and cost reduction.

[0074] [Variations] The structure of the inner panel 21 in this modified example will be described with reference to Fig. 6. Fig. 6 schematically illustrates only a portion of the junction 21h and its surrounding structure within the structure of the inner panel 21, and the remaining structure of the back door 1, including the outer panel 10, is the same as in the above embodiment. Also in this modified example, two junctions are provided symmetrically, but Fig. 6 illustrates only one of the junctions 21h, omitting the illustration of the other junction.

[0075] As shown in Fig. 6, in the inner panel 21 of the vehicle back door 1 according to this modification, the joining portion 21h where the horizontal skeleton portion 21g and the vertical skeleton portion 21e join has a linear edge portion Lh2 on the side of the opening SP1. Note that, although Fig. 6 shows the linear edge portion Lh2 as an edge portion formed by a single straight line, it may also have a shape formed by combining a plurality of straight lines.

[0076] The point of contact between the end of vertical skeleton 21e on the opening SP1 side in the width direction and straight edge Lh2 is designated as P3, and the point of contact between the end of horizontal skeleton 21g on the opening SP1 side in the width direction and straight edge Lh2 is designated as P4. An imaginary line L3 extending in the width direction of vertical skeleton 21e is drawn from contact point P3, and an imaginary line L4 extending in the width direction of horizontal skeleton 21g is drawn from contact point P4. In this case, the portion above imaginary line L3 (the portion indicated by arrow C1) and to the right of imaginary line L4 (the portion indicated by arrow C2) is defined as junction 21h.

[0077] In this modified example, the same configuration as in the above embodiment can be employed except that the confluence portion 21h has the linear edge portion Lh2, and therefore the same effects as in the above embodiment can be achieved.

[0078] [Other variations] In the above embodiment, the merging sections 11h, 11i have a substantially triangular shape in a front view from the front of the vehicle, but the present invention is not limited to this. For example, a polygonal shape such as a square or hexagonal shape, or a circular or elliptical shape may also be adopted.

[0079] In the above embodiment, the inner panel 11 has three connecting portions 11j to 11l, but in the present invention, it is sufficient if the inner panel 11 has at least one connecting portion.

[0080] In addition, in the above embodiment, a configuration was adopted in which three connecting portions 11j to 11l are arranged so as to overlap each other in a side view from the left and right directions in the vertical direction of the tailgate 1, but in the present invention, it is not necessarily required that multiple connecting portions are arranged so as to overlap each other.

[0081] In the above embodiment, a configuration was adopted in which a bead 11j4 was formed on the vertical wall portion 11j3 of the central connecting portion 11j, but in the present invention, a configuration can be adopted in which a bead is formed on the vertical wall portion of all connecting portions, or a configuration can be adopted in which a bead is not formed on each vertical wall portion of all connecting portions.

[0082] In the above embodiment, a configuration is adopted in which the connecting portions 11j to 11l are formed integrally with the skeleton portions 11e to 11g of the inner panel 11, but in the present invention, it is also possible to adopt connecting portions that are separate from the inner panel.

[0083] In the above embodiment, the central connector 11j extends toward the opening SP1, the side connector 11k extends toward the opening SP2, and the side connector 11l extends toward the opening SP3. However, the present invention is not limited to this. For example, the central connector and the side connector may each extend toward the opening SP4.

[0084] In the above embodiment, a configuration was adopted in which the extension direction of the upper portion 11e2, 11f2 and the lower portion 11e1, 11f1 of each vertical skeleton portion 11e, 11f changes at the junction portion 11h, 11i, but in the present invention, it is also possible to adopt a configuration in which the vertical skeleton portion extends in a straight line from the upper portion to the lower portion.

[0085] In the above embodiment, the inner panel 11 has four openings SP1 to SP4, but the present invention can also employ a configuration having five or more openings.

[0086] In the above embodiment, the confluence portions 11h, 11i of the inner panel 11 are configured to have a larger area in a plan view in order to provide higher torsional rigidity than the vertical skeleton portions 11e, 11f and the horizontal skeleton portion 11g, but the present invention is not limited to this. For example, the thickness of the confluence portions may be made thicker than the vertical skeleton portions or the horizontal skeleton portions, or a reinforcing member may be provided only at the confluence portions. It is also possible to employ reinforcing beads or a concave-convex structure only at the confluence portions.

[0087] Furthermore, in the above embodiment, the inner panel 11 has the outer peripheral skeleton portions 11a to 11d, but in the present invention, it is not always necessary for the inner panel to have an outer peripheral skeleton portion.

[0088] In the above embodiment, the central connector 11j connects the lower end of the horizontal frame 11g in the vertical width direction to the outer panel 10, the side connector 11k connects the lower end of the upper portion 11e2 of the vertical frame 11e in the vertical width direction to the outer panel 10, and the side connector 11l connects the lower end of the upper portion 11f2 of the vertical frame 11f in the vertical width direction to the outer panel 10. However, the present invention is not limited to this configuration. For example, it is also possible to adopt a configuration opposite to the above embodiment, in which the central connector connects the upper end of the horizontal frame in the vertical width direction to the outer panel, and the side connectors on both sides connect the upper end of the upper portion of each vertical frame in the vertical width direction to the outer panel. Even when the connectors are arranged in this manner, the same effects as those of the above embodiment can be achieved. [Explanation of symbols]

[0089] 1. Backdoor 1a Window opening 10 outer panel 11,21 Inner panel 11e, 11f, 21e Vertical skeleton 11e1,11f1 bottom 11e2,11f2 Upper part 11g, 21g Lateral skeleton 11h,11i,21h Confluence 11j~11l Connection part 11j4 bead SP1~SP4 opening

Claims

1. A structure of a back door of a vehicle having a window opening to which a windshield is attached, an outer panel that constitutes the outer side of the vehicle at the back door; an inner panel that configures the inside of the vehicle at the back door; a connecting portion that connects the outer panel and the inner panel; Equipped with The inner panel is a first opening provided above a lower edge of the inner panel in a portion below the window opening; a second opening provided between the first opening and the window opening; a third opening provided between the first opening, the second opening, and a right edge of the inner panel; a fourth opening provided between the first opening, the second opening, and a left edge of the inner panel; a first vertical frame portion provided to extend in the up-down direction between the first opening, the second opening, and the third opening; a second vertical frame portion provided to extend in the up-down direction between the first opening, the second opening, and the fourth opening; a horizontal frame portion provided to extend in the left-right direction between the first opening and the second opening; a first joining portion provided at a joining portion between the horizontal skeleton portion and the first vertical skeleton portion; a second joining portion provided at a joining portion of the horizontal skeleton portion and the second vertical skeleton portion; and the connecting portion connects at least one of the horizontal skeleton portion, the first vertical skeleton portion, and the second vertical skeleton portion to the outer panel, and connects only one end portion of the at least one skeleton portion in the width direction to the outer panel; the first joining portion and the second joining portion are formed to have higher torsional rigidity than the horizontal skeleton portion, the first vertical skeleton portion, and the second vertical skeleton portion, respectively; When the first vertical framework portion is divided into an upper portion as a first upper portion and a lower portion as a first lower portion with the first junction portion as a boundary, the angle of the first upper portion with respect to an axis along the vertical direction of the tailgate is formed to be larger than that of the first lower portion located below the first junction portion, and the first junction portion is located at the junction portion of the first upper portion and the first lower portion, When the second vertical framework portion has an upper portion as a second upper portion and a lower portion as a second lower portion with the second junction portion as a boundary, the angle of the second upper portion with respect to an axis along the vertical direction of the tailgate is formed to be larger than that of the second lower portion located below the second junction portion, and the second junction portion is located at the junction portion of the second upper portion and the second lower portion, the first joining portion is formed to have an expanding shape in a plan view such that a lower edge thereof is positioned gradually lower as it goes from the side of the horizontal skeleton portion to the side of the first vertical skeleton portion, the second joining portion is formed to have an expanding shape in a plan view such that a lower edge thereof is positioned downward as it goes from the side of the horizontal skeleton portion to the side of the second vertical skeleton portion, The first vertical frame portion, the second vertical frame portion, and the horizontal frame portion are arranged at height positions where a lower portion of the first upper portion, a lower portion of the second upper portion, and both left and right end portions of the horizontal frame portion overlap each other in the vehicle up-down direction. Vehicle back door structure.

2. The vehicle back door structure according to claim 1, Each of the first junction portion and the second junction portion is formed to have a larger vertical dimension than the horizontal skeleton portion, and a larger horizontal dimension than each of the first vertical skeleton portion and the second vertical skeleton portion. Vehicle back door structure.

3. The vehicle back door structure according to claim 1 or 2, the first junction has a width in the left-right direction that gradually increases from a lower portion to an upper portion, and has a substantially triangular shape that is substantially symmetrical with respect to a center line in the left-right direction of the first junction in a front view, The second junction has a width in the left-right direction that gradually increases from the bottom to the top, and has a substantially triangular shape that is substantially symmetrical with respect to the center line of the left and right sides of the second junction in a front view. Vehicle back door structure.

4. The vehicle back door structure according to claim 1 or 2, The connecting portion is a first connecting portion that connects only one end portion of the horizontal frame portion in the width direction to the outer panel; a second connecting portion that connects only one end portion of the first vertical frame portion in the width direction to the outer panel; a third connecting portion that connects only one end portion of the second vertical frame portion in the width direction to the outer panel; having Vehicle back door structure.

5. The vehicle back door structure according to claim 4, The first connecting portion, the second connecting portion, and the third connecting portion are provided so as to overlap each other in a side view from the left-right direction. Vehicle back door structure.

6. The vehicle back door structure according to claim 4, the first connecting portion has a connecting wall portion that connects the outer panel and the inner panel in the front-rear direction, The connecting wall portion has a bead formed to extend in the front-rear direction. Vehicle back door structure.

7. The vehicle back door structure according to claim 4, The first connecting portion is integrally formed with the horizontal skeleton portion, the second connecting portion is integrally formed with the first vertical frame portion, The third connecting portion is integrally formed with the second vertical frame portion. Vehicle back door structure.

8. The vehicle back door structure according to claim 4, the first connecting portion connects only the one end portion of the horizontal frame portion on the first opening side in the width direction to the outer panel, the second connecting portion connects only the one end portion of the first vertical frame portion on the third opening side in the width direction to the outer panel, the third connecting portion connects only the one end portion of the second vertical frame portion on the fourth opening side in the width direction to the outer panel; Vehicle back door structure.

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