Reinforcement structure of the back door

Abstract

To provide a back door reinforcement structure which can suppress vibration being a noise factor within a cabin.SOLUTION: A reinforcement structure of a back door 11 used for a vehicle application comprises a reinforcement part 13 which reinforces a back door body 12. A door top 21 comprises a pair of side frame members (a first side frame member 22 and a second side frame member 23). Each of the pair of side frame members has a first hollow part H1 extending in a vertical direction. A bottom panel body 32 of a door bottom 31 has a second hollow part H2 between a first bottom panel part 32a and a second bottom panel part. The reinforcement part 13 has a first reinforcement part 41 disposed in each first hollow part H1 and a second reinforcement part 42 disposed in the second hollow part H2. Each first reinforcement part 41 has a first foam anchored on the side frame member. The second reinforcement part 42 has a second foam anchored on both of the first bottom panel part 32a and the second bottom panel part and disposed separating from the first reinforcement part 41.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a reinforcement structure for a back door used for vehicle applications.

Background Art

[0002] As described in Patent Document 1, as a back door used for vehicle applications, there is known one having a first panel portion, a second panel portion disposed apart from the first panel portion at a position on the front side of the vehicle with respect to the first panel portion, and a hollow portion between the first panel portion and the second panel portion.

Prior Art Documents

Patent Documents

[0003] ​​​​​​​​​​​​​​​​​​​​​​​​​​​The reinforcing structure for a back door of Embodiment 1 is a reinforcing structure for a back door used in a vehicle, comprising a back door body having a window opening and a reinforcing part that reinforces the back door body, wherein the back door body has an upper part which is the door upper section and a lower part which is the door lower section, with a first horizontal line passing through the lowest end of the window opening as the upper boundary line, the door upper section comprises a pair of side frame members that form both side edges of the window opening between the first horizontal line and a second horizontal line passing through the highest end of the window opening, each of the pair of side frame members has a first hollow section extending in the vertical direction, and the door lower section is connected to the pair of side frame members The lower panel body is connected to a lower panel body which comprises a first lower panel portion, a second lower panel portion spaced apart from the first lower panel portion at a position in front of the vehicle, and a second hollow portion between the first lower panel portion and the second lower panel portion. The reinforcing portion comprises a first reinforcing portion located in each of the first hollow portions and a second reinforcing portion located in the second hollow portion. Each of the first reinforcing portions has a first foam material fixed to the side frame member, and the second reinforcing portion has a second foam material fixed to either the first lower panel portion or the second lower panel portion and spaced apart from the first reinforcing portion.

[0007] With this configuration, the rigidity of the pair of side frame members having a first hollow section at the top of the door can be increased by the first foam of the first reinforcing section. This makes it possible to suppress vibrations at the top of the door. However, when the rigidity of the top of the door is increased in this way, the lower panel body having a second hollow section at the bottom of the door may become more prone to vibration. With the above configuration, in a structure in which the rigidity of the top of the door is increased, the rigidity of the lower panel body can be increased by the second foam of the second reinforcing section. This makes it possible to suppress vibrations at the bottom of the door that occur when the rigidity of the top of the door is increased. In other words, the first foam of the first reinforcing section and the second foam of the second reinforcing section make it possible to suppress vibrations of the back door body from the top of the door to the bottom of the door.

[0008] In the reinforcing structure of the back door according to embodiment 2, in embodiment 1, the second reinforcing portion may be positioned more towards the center than the first reinforcing portion in the left-right direction of the vehicle. For example, by positioning the second reinforcing portion in this manner, it becomes possible to suppress vibrations at the bottom of the door in a balanced manner.

[0009] In the reinforcing structure for the back door of Embodiment 3, in Embodiment 1 or Embodiment 2, the first lower panel portion has a license plate mounting portion to which a license plate is attached, and the second foam may be fixed to the back surface of the license plate mounting portion. Here, although the second foam, which is placed in the second hollow portion of the lower part of the door, is fixed to the first lower panel portion, vibrations of the lower part of the door can be suppressed, but distortion may occur in the first lower panel portion. Such distortion of the first lower panel portion may reduce the aesthetic appeal of the lower part of the door. With the above configuration, since the second foam is fixed to the back surface of the license plate mounting portion in the first lower panel portion, the distortion portion of the first lower panel portion caused by the fixing of the second foam can be concealed by the license plate. This makes it possible to maintain the aesthetic appeal of the lower part of the door.

[0010] In the back door reinforcement structure of Embodiment 4, in any one of Embodiments 1 to 3, the first reinforcement portion further comprises a first support that supports the first foam, and the first support may be fixed to the side frame member. With this configuration, the reinforcing performance of the first reinforcement portion that reinforces the side frame member can be improved by the first support.

[0011] In the back door reinforcement structure of Embodiment 5, in any one of Embodiments 1 to 4, the second reinforcement portion further comprises a second support that supports the second foam, and the second support may be fixed to the lower panel body. With this configuration, the reinforcing performance of the second reinforcement portion that reinforces the lower panel body can be improved by the second support. [Effects of the Invention]

[0012] This invention is effective in suppressing vibrations that cause noise inside a vehicle cabin. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a front view showing a back door with a reinforcing portion in an embodiment. [Figure 2] Figure 2 is a cross-sectional view along line 2-2 in Figure 1. [Figure 3] Figure 3 is a cross-sectional view along line 3-3 in Figure 1. [Figure 4] Figure 4 is a cross-sectional view showing the state before the formation of the first foam in Figure 2. [Figure 5] Figure 5 is a cross-sectional view showing the state before the formation of the second foam in Figure 3. [Modes for carrying out the invention]

[0014] Below, one embodiment of the reinforcement structure for the back door will be described with reference to the drawings. As shown in Figure 1, the reinforcing structure of the back door 11 used in vehicle applications comprises a back door body 12 and a reinforcing part 13 that reinforces the back door body 12. The back door body 12 has a window opening 12a.

[0015] <Back door body 12> The back door body 12 has a door upper part 21 and a door lower part 31. The door upper part 21 is the upper part when the first horizontal line L1 passing through the lowest end E1 of the window opening 12a is used as the upper boundary line. The door lower part 31 is the lower part when the first horizontal line L1 is used as the upper boundary line. A sheet material such as glass or resin is assembled into the window opening 12a of the door upper part 21. The back door body 12 is pivotably mounted to the rear end of the vehicle.

[0016] <Door Top 21> The upper part 21 of the door includes a first side frame member 22 and a second side frame member 23 that form both side edges of the window opening 12a between a first horizontal line L1 and a second horizontal line L2 passing through the uppermost end E2 of the window opening 12a. Each of the first side frame member 22 and the second side frame member 23 has a first hollow portion H1 extending in the vertical direction.

[0017] As shown in FIG. 2, the first side frame member 22 has a plurality of frame panel members that are components of the first side frame member 22. The plurality of frame panel members include, for example, a first frame panel member 24a and a second frame panel member 24b disposed on the rear side of the vehicle with respect to the first frame panel member 24a. The plurality of frame panel members can be made of, for example, a metal material such as a steel plate, a non-metal material such as a resin material, or a combination of a metal material and a non-metal material. The plurality of frame panel members can be joined by a well-known joining method according to the material. For example, when the plurality of frame panel members are made of a metal material, the plurality of frame panel members can be joined using spot welding.

[0018] The second side frame member 23 has a shape that is symmetric with the first side frame member 22 about the left-right direction. Such a second side frame member 23 can also be composed of a plurality of frame panel members in the same manner as the first side frame member 22.

[0019] <Lower part 31 of the door> As shown in FIG. 1, the lower part 31 of the door has a lower panel body 32 connected to the first side frame member 22 and the second side frame member 23. As shown in FIGS. 1 and 3, the lower panel body 32 has a first lower panel part 32a and a second lower panel part 32b disposed at a position spaced apart from the first lower panel part 32a on the front side of the vehicle. The lower panel body 32 has a second hollow portion H2 between the first lower panel part 32a and the second lower panel part 32b.

[0020] The first lower panel portion 32a constitutes the outer panel of the lower part of the door 31. The first lower panel portion 32a has a license plate mounting portion 33 to which a license plate (not shown) is mounted. The license plate mounting portion 33 of the present embodiment is provided on the center side of the first side frame member 22 and the second side frame member 23 in the left-right direction (vehicle width direction) of the vehicle. Note that the position of the license plate mounting portion 33 is not limited to the position of the present embodiment, and can be changed to a position such as the right end side or the left end side of the first lower panel portion 32a, for example.

[0021] The first lower panel portion 32a and the second lower panel portion 32b can be formed of, for example, a metal material such as a steel plate, a non-metal material such as a resin material, or a material combining a metal material and a non-metal material. The first lower panel portion 32a and the second lower panel portion 32b can be joined by a well-known joining method according to the material. For example, when the first lower panel portion 32a and the second lower panel portion 32b are made of a metal material, the first lower panel portion 32a and the second lower panel portion 32b can be joined using spot welding. The lower panel body 32 may further have panel portions other than the first lower panel portion 32a and the second lower panel portion 32b. For example, the lower panel body 32 may further have a reinforcement panel disposed between the first lower panel portion 32a and the second lower panel portion 32b.

[0022] <Reinforcement portion 13> As shown in FIG. 1, the reinforcement portion 13 has a first reinforcement portion 41 disposed in each of the first hollow portion H1 of the first side frame member 22 and the first hollow portion H1 of the second side frame member 23, and a second reinforcement portion 42 disposed in the second hollow portion H2. Since each first reinforcement portion 41 has the same configuration, the first reinforcement portion 41 disposed in the first hollow portion H1 of the first side frame member 22 will be described.

[0023] As shown in FIG. 2, the first reinforcement portion 41 has a first foam body 41a fixed to the first side frame member 22. The first foam body 41a can be obtained by heating and curing the first foamable member 51 shown in FIG. 4.

[0024] The first foamed member 51 is obtained by molding a foamed material by a well-known molding method such as extrusion molding, press molding, or injection molding. The foamed material contains a base material, a foaming agent, and a crosslinking agent. The foamed material may contain fillers, plasticizers, etc., as needed. Examples of base materials include synthetic resins, elastomers, and rubbers. Examples of synthetic resins include polyolefins, epoxy resins, phenolic resins, urethane resins, acrylic resins, styrene resins, and EVA (ethylene / vinyl acetate copolymer). Examples of elastomers include RB (polybutadiene elastomer), SBS (styrene / butadiene / styrene block copolymer), SIS (styrene / isoprene / styrene block copolymer), and SEBS (styrene / ethylene / butylene / styrene block copolymer). Examples of rubbers include NR (natural rubber), SBR (styrene / butadiene rubber), BR (butadiene rubber), NBR (nitrile rubber), CR (chloroprene rubber), IR (isoprene rubber), IIR (butyl rubber), EPDM (ethylene propylene diene terpolymer), UR (urethane rubber), ENR (epoxidized natural rubber), and EPM (ethylene / propylene rubber). Examples of foaming agents include azodicarbonamide and dinitropentamethylenetetramine, examples of crosslinking agents include the well-known dimethylurea and dicyandiamide, and examples of fillers include calcium carbonate, barium sulfate, ferrite, and silica.

[0025] As shown in Figures 2 and 4, the first reinforcing portion 41 further includes a first support 41b that supports the first foam 41a. The first support 41b is fixed to the first side frame member 22. More specifically, the first support 41b has a first support portion S1 that supports the first foam 41a (first foamable member 51) and a first fixing portion F1 that fixes the first support portion S1 to the first side frame member 22. The first fixing portion F1 can be configured to engage with a mounting hole that penetrates the first side frame member 22. Examples of materials for the first support 41b include resin materials such as polyamide and metal materials such as steel.

[0026] As shown in Figures 3 and 5, the second reinforcing portion 42 has a second foam 42a that is fixed to both the first lower panel portion 32a and the second lower panel portion 32b and is positioned spaced apart from the first reinforcing portion 41. The second foam 42a can be obtained by heating and foaming and hardening the second foamable member 52 shown in Figure 5. The second foamable member 52 can be obtained by molding a foamable material using well-known molding methods such as extrusion molding, press molding, and injection molding. As the foamable material, the material exemplified as the foamable material for the first foamable member 51 can be used.

[0027] As shown in Figure 1, the second reinforcing portion 42 is positioned more towards the center than the first reinforcing portion 41 in the left-right direction of the vehicle. The second foam 42a is fixed to the back surface of the license plate mounting portion 33 of the first lower panel portion 32a. That is, on the first lower panel portion 32a, the outer surface opposite to the inner surface to which the second foam 42a is fixed is covered by the license plate.

[0028] As shown in Figures 3 and 5, the second reinforcing portion 42 further has a second support 42b that supports the second foam 42a. The second support 42b is fixed to the lower panel body 32 (second lower panel portion 32b). More specifically, the second support 42b has a second support portion S2 that supports the second foam 42a (second foamable member 52) and a second fixing portion F2 that fixes the second support portion S2 to the lower panel body 32. The second fixing portion F2 can be configured to engage with a mounting hole that penetrates the lower panel body 32. Examples of materials for the second support 42b include resin materials such as polyamide and metal materials such as steel.

[0029] <Method for forming the reinforcing structure of the back door 11> Next, a method for forming the reinforcing structure of the back door 11 will be described. The reinforcing structure of the back door 11 is formed by providing a reinforcing section 13 to the back door body 12. The first foam 41a of the first reinforcing section 41 can be formed from a first foamable member 51 placed in the first hollow section H1 of the back door body 12, as shown in Figure 4. The second foam 42a of the second reinforcing section 42 can be formed from a second foamable member 52 placed in the second hollow section H2 of the back door body 12, as shown in Figure 5. More specifically, the first foamable member 51 placed in the first hollow section H1 and the second foamable member 52 placed in the second hollow section H2 are heated from the outside to foam and harden the first foamable member 51 and the second foamable member 52. This allows the first foam 41a and the second foam 42a described above to be formed. For heating the first foamable member 51 and the second foamable member 52, for example, the drying process when painting (electrodeposition coating) the back door body 12 can be used. Furthermore, a well-known heating device utilizing a heat source such as electricity or steam may be used to heat the first foamed member 51 and the second foamed member 52.

[0030] In this embodiment, the first foamed member 51 can be positioned by fixing the first support 41b to the first side frame member 22. Also in this embodiment, the second foamed member 52 can be positioned by fixing the second support 42b to the lower panel body 32 (second lower panel portion 32b).

[0031] <Operation and Effects of This Embodiment> Next, the operation and effects of this embodiment will be described. (1) The reinforcing structure of the back door 11 used for vehicle applications comprises a back door body 12 having a window opening 12a and a reinforcing part 13 that reinforces the back door body 12. The upper part 21 of the back door body 12 comprises a pair of side frame members, a first side frame member 22 and a second side frame member 23. Each of the first side frame member 22 and the second side frame member 23 has a first hollow part H1 that extends in the vertical direction. The lower part 31 has a lower panel body 32 connected to the first side frame member 22 and the second side frame member 23. The lower panel body 32 has a second hollow part H2 between a first lower panel part 32a and a second lower panel part 32b. The reinforcing part 13 comprises a first reinforcing part 41 positioned in each first hollow part H1 and a second reinforcing part 42 positioned in the second hollow part H2. Each first reinforcing portion 41 has a first foam 41a fixed to the first side frame member 22 and the second side frame member 23, respectively. The second reinforcing portion 42 has a second foam 42a fixed to either the first lower panel portion 32a or the second lower panel portion 32b, and positioned spaced apart from the first reinforcing portion 41.

[0032] With this configuration, the rigidity of the first side frame member 22 and the second side frame member 23, which have a first hollow portion H1 in the upper part 21 of the door, can be increased by the first foam 41a of the first reinforcing part 41. This makes it possible to suppress vibrations of the upper part 21 of the door. However, when the rigidity of the upper part 21 of the door is increased in this way, the lower panel body 32, which has a second hollow portion H2 in the lower part 31 of the door, may become more prone to vibration. With the above configuration, in a structure in which the rigidity of the upper part 21 of the door is increased, the rigidity of the lower panel body 32 can be increased by the second foam 42a of the second reinforcing part 42. This makes it possible to suppress vibrations of the lower part 31 of the door that occur when the rigidity of the upper part 21 of the door is increased. In other words, the first foam 41a of the first reinforcing part 41 and the second foam 42a of the second reinforcing part 42 make it possible to suppress vibrations of the back door body 12 from the upper part 21 of the door to the lower part 31 of the door.

[0033] (2) The second reinforcing part 42 is positioned more towards the center than the first reinforcing part 41 in the left-right direction of the vehicle. For example, by positioning the second reinforcing part 42 in this manner, it becomes possible to suppress vibrations of the lower part of the door 31 in a balanced manner.

[0034] (3) As described above, the second foam 42a, which is placed in the second hollow portion H2 of the lower part of the door 31, is fixed to the first lower panel portion 32a, which can suppress vibrations of the lower part of the door 31, but distortion may occur in the first lower panel portion 32a. Such distortion of the first lower panel portion 32a may reduce the aesthetic appeal of the lower part of the door 31. The first lower panel portion 32a of this embodiment has a license plate mounting portion 33 to which a license plate is attached. The second foam 42a of the second reinforcing portion 42 is fixed to the back surface of the license plate mounting portion 33. In this case, the distortion of the first lower panel portion 32a caused by the fixing of the second foam 42a can be concealed by the license plate. This makes it possible to maintain the aesthetic appeal of the lower part of the door 31.

[0035] (4) The first reinforcing portion 41 positioned in the first hollow portion H1 of the first side frame member 22 further has a first support 41b that supports the first foam 41a. This first support 41b is fixed to the first side frame member 22. In this case, the reinforcing performance of the first reinforcing portion 41 that reinforces the first side frame member 22 can be improved by the first support 41b. Also, the first reinforcing portion 41 positioned in the first hollow portion H1 of the second side frame member 23 further has a first support 41b that supports the first foam 41a. This first support 41b is fixed to the second side frame member 23. In this case, the reinforcing performance of the first reinforcing portion 41 that reinforces the second side frame member 23 can be improved by the first support 41b.

[0036] (5) The second reinforcing section 42 further has a second support 42b that supports the second foam 42a. The second support 42b is fixed to the lower panel 32. In this case, the reinforcing performance of the second reinforcing section 42 that reinforces the lower panel 32 can be improved by the second support 42b.

[0037] <Example of changes> The above embodiment may be modified and configured as follows. The above embodiment and the following modifications can be combined and implemented to the extent that they do not contradict each other technically.

[0038] • A first support 41b is placed in the first hollow portion H1 of the first side frame member 22, but this first support 41b can be omitted. • The first support 41b is placed in the first hollow portion H1 of the second side frame member 23, but this first support 41b can be omitted.

[0039] • A second support 42b is placed in the second hollow portion H2 of the lower panel body 32, but this second support 42b can be omitted. The second foam 42a of the second reinforcing section 42 is fixed to the back surface of the license plate mounting section 33, but it can also be fixed to a different part of the back surface of the first lower panel section 32a than the back surface of the license plate mounting section 33. Even in this case, the first foam 41a of the first reinforcing section 41 and the second foam 42a of the second reinforcing section 42 make it possible to suppress vibrations of the back door body 12 from the upper part 21 to the lower part 31 of the door.

[0040] The second reinforcing portion 42 is positioned more towards the center than the first reinforcing portion 41 in the left-right direction of the vehicle, but it may also be positioned so as to partially overlap with the first reinforcing portion 41 in the left-right direction of the vehicle.

[0041] The first reinforcing portion 41 is provided near the lower end of the first hollow portion H1, but it can also be provided in the central part or near the upper end in the vertical direction of the first hollow portion H1. The first side frame member 22 is composed of multiple panel members, but it can also be composed of a hollow pipe that is integrally molded. The second side frame member 23 can also be composed of a hollow pipe that is integrally molded.

[0042] The first side frame member 22 may have three or more frame panel members. For example, the first side frame member 22 may further have a reinforcement panel positioned between the first frame panel member 24a and the second frame panel member 24b. The reinforcement panel can be positioned, for example, to partition the first hollow portion H1 formed by the first frame panel member 24a and the second frame panel member 24b. In this case, the first reinforcing portion 41 may be positioned between the first frame panel member 24a and the reinforcement panel, or between the second frame panel member 24b and the reinforcement panel.

[0043] Furthermore, the second side frame member 23 may also have three or more frame panel members, in which case it can be modified as described above for the first side frame member 22. The shape of the lower edge of the window opening 12a is not limited to a shape along the horizontal line, but may also be a curved shape that is convex downwards, for example. Similarly, the shape of the upper edge of the window opening 12a is not limited to a shape along the horizontal line, but may also be a curved shape that is convex upwards, for example.

[0044] In the reinforcing structure of the back door 11, a third foam, which is a foam other than the first foam 41a and the second foam 42a, can also be provided on the back door body 12. [Explanation of symbols]

[0045] 11... Back door 12... Back door body 12a... Window opening 13…Reinforcement 21... Top of the door 22...First side frame member 23...Second side frame member 31...Lower part of the door 32...Lower panel 32a...First lower panel section 32b...Second lower panel section 33…License plate mounting area 41…First reinforcement section 41a...First foam 41b…First Supporter 42…Second Reinforcement Section 42a…Second bubble body 42b…Second Support E1…bottom E2…Top H1…First Hollow Section H2…Second Hollow Section L1…First horizontal line L2…Second horizontal line

Claims

1. A reinforcing structure for a back door used in vehicle applications, It comprises a back door body having a window opening and a reinforcing part that reinforces the back door body, The aforementioned back door body has an upper door portion and a lower door portion, with the upper boundary line being the first horizontal line passing through the lowest edge of the window opening. The upper part of the door comprises a pair of side frame members that form both side edges of the window opening between the first horizontal line and the second horizontal line passing through the uppermost end of the window opening, Each of the pair of side frame members has a first hollow portion extending in the vertical direction, The lower part of the door has a lower panel body connected to the pair of side frame members, The lower panel body comprises a first lower panel section and A second lower panel portion is positioned at a distance from the first lower panel portion, at a location on the front side of the vehicle, It has a second hollow portion between the first lower panel portion and the second lower panel portion, The reinforcing portion comprises a first reinforcing portion arranged in each of the first hollow portions, It has a second reinforcing portion disposed in the second hollow portion, Each of the first reinforcing parts has a first foam body that is fixed to the side frame member. The back door reinforcing structure comprises a second foam body which is fixed to both the first lower panel and the second lower panel and is positioned at a distance from the first reinforcing portion.

2. The back door reinforcement structure according to claim 1, wherein the second reinforcement portion is positioned more towards the center than the first reinforcement portion in the left-right direction of the vehicle.

3. The first lower panel portion has a license plate mounting portion on which a license plate is attached, The reinforcing structure for a back door according to claim 1, wherein the second foam is fixed to the back surface of the license plate mounting portion.

4. The first reinforcing portion further comprises a first support that supports the first foam, The reinforcing structure for a back door according to claim 1, wherein the first support is fixed to the side frame member.

5. The second reinforcing portion further comprises a second support that supports the second foam, The reinforcing structure for a back door according to claim 1, wherein the second support is fixed to the lower panel body.

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