JP2023156110A - Back door structure - Google Patents

Abstract

To provide a back door structure in which vibrations of a door inner and a door outer can be further reduced.SOLUTION: A back door structure comprises: a back door 14 having a door inner 22 and a door outer 20 joined to the door inner 22; a speaker 34 mounted on the back door 14; and reinforcement members 40, whose one ends are directly or indirectly fixed to the door inner 22 and whose other ends are directly or indirectly fixed to the door outer 20, and which protrude in a door thickness direction, between the door inner 22 and the door outer 20. The two reinforcement members 40 are arranged with an interval in a vehicle width direction, and the reinforcement members 40 are arranged at positions separated from a center in the vehicle width direction of the back door 14.SELECTED DRAWING: Figure 1

Description

This specification discloses a back door structure in which a speaker is attached to the back door.

Some vehicles have a back door opening at the back of the vehicle. The back door opening is opened and closed by the back door. A back door usually has a door inner and a door outer joined to the door inner. Some people have proposed attaching a speaker to this back door. For example, Patent Document 1 discloses that a circular opening for attaching a speaker is formed in a door inner (referred to as an "inner panel" in Patent Document 1).

JP 2018-30553 Publication

Here, when a speaker is attached to the back door, the inner door and the outer door may vibrate due to sound output from the speaker. Such vibrations of the door inner and the door outer may cause abnormal noise or deteriorate the sound quality of the speaker.

Note that Patent Document 1 discloses joining a reinforcing member to a door inner. However, the reinforcing member of Patent Document 1 is provided to suppress deformation of the back door starting from the belt line portion. Therefore, the technique disclosed in Patent Document 1 could not sufficiently reduce the vibrations of the door inner and door outer caused by the sound output of the speaker.

Therefore, this specification discloses a back door structure that can further reduce vibrations of the door inner and the door outer.

The back door structure disclosed in this specification includes a back door having a door inner and a door outer joined to the door inner, a speaker attached to the door inner, and one end directly or indirectly fixed to the door inner, a reinforcing member whose other end is directly or indirectly fixed to the door outer and which extends in the door thickness direction between the door inner and the door outer, the reinforcing members being spaced apart in the vehicle width direction, Two reinforcing members are provided, and each reinforcing member is provided at a position spaced apart from the center of the back door in the vehicle width direction.

By stretching the reinforcing member between the door inner and the door outer in the door thickness direction, movement of the door inner and the door outer in the thickness direction, and thus vibration, can be effectively prevented. Furthermore, by providing the reinforcing member at a position spaced apart from the center of the back door in the vehicle width direction, not only vibrations in the primary vibration mode but also vibrations in the secondary vibration mode can be effectively suppressed.

It is a diagram seen from behind the vehicle. It is a view of the door inner seen from behind. 3 is a sectional view taken along line AA in FIG. 2. FIG. 3 is a sectional view taken along line BB in FIG. 2. FIG.

The backdoor structure will be described below with reference to the drawings. FIG. 1 is a diagram of a vehicle 10 viewed from behind. Moreover, FIG. 2 is a diagram of the door inner 22 seen from behind. Furthermore, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. 4 is a sectional view taken along line BB in FIG.

As shown in FIG. 1, the back door of the vehicle 10 is provided with a back door opening 12 and a back door 14 that covers the back door opening 12 so as to be openable and closable. The back door 14 includes a door outer 20 and a door inner 22 (not visible in FIG. 1) arranged on the vehicle front side from the door outer 20. The door outer 20 and the door inner 22 face each other in the longitudinal direction of the vehicle, and the back door 14 is configured by joining their peripheral edges to each other.

A rear window 26 is provided above the back door 14. The back door 14 can be roughly divided into a main body 16 located below the rear window 26 and a frame 18 surrounding the rear window 26.

The door outer 20 is a panel material that constitutes the vehicle outer surface of the back door 14. In FIG. 1, the door outer 20 is illustrated as having almost no irregularities or curved surfaces, but in reality, from the viewpoint of component arrangement and design, the door outer 20 is provided with many irregularities and curved surfaces. There is. A plate mounting surface 32 is provided near the lower end of the door outer 20 and approximately at the center in the vehicle width direction. The plate mounting surface 32 is a portion depressed from the surrounding area, and is a flat surface that is sufficiently larger than the license plate 30. The license plate 30 is attached to this plate attachment surface 32.

The door inner 22 is a panel material that constitutes the surface of the back door 14 on the vehicle interior side. In FIG. 2, the door inner 22 is illustrated as having almost no irregularities or curved surfaces, but in reality, from the viewpoint of component arrangement and design, the door inner 22 is provided with many irregularities and curved surfaces. There is. As shown in FIG. 2, a lock mounting hole is provided near the lower end of the door inner 22, approximately in the center in the vehicle width direction, and facing the plate mounting surface 32 in the longitudinal direction of the vehicle, for mounting a door lock (not shown). 36 are formed. A lock reinforcement (hereinafter referred to as "lock R/F") 38 that reinforces the strength around the lock mounting hole 36 is joined to the lower side of the lock mounting hole 36 . The lock R/F 38 is a sheet metal member that stands toward the rear of the vehicle from the door inner 22, and is approximately U-shaped with an upward opening when viewed from the rear of the vehicle. As shown in FIG. 3, this lock R/F 38 includes a flange portion 38b that overlaps the door inner 22 in the thickness direction and is joined to the door inner 22, and a rising portion 38a that stands from the end of the flange portion 38b to the rear of the vehicle. , has. A reinforcing member 40 is further joined to this lock R/F 38, which will be described later.

As shown in FIG. 2, a speaker 34 is further attached to the door inner 22. In this example, a substantially circular speaker hole 35 is formed in the door inner 22 on the upper right side of the lock attachment hole 36, and a speaker 34 is fixed to this speaker hole 35. Naturally, the speaker 34 has a built-in diaphragm (not shown), and by vibrating this diaphragm, sound is output.

Here, when such a speaker 34 is attached to the door inner 22, the back door 14 may also vibrate due to the sound output from the speaker 34. If the back door 14 vibrates excessively, abnormal noise may be generated or the quality of the sound output from the speaker 34 may deteriorate. In order to suppress such vibrations of the back door 14, it may be possible to increase the thickness of the door outer 20 and the door inner 22, but in this case, other problems such as an increase in weight and an increase in cost arise. Therefore, in this example, a reinforcing member 40 is provided in order to suppress the vibration of the door inner 22 and the like while suppressing an increase in the thickness of the door inner 22 and the like.

The reinforcing member 40 is a plate-shaped member that is bent multiple times. As shown in FIG. 3, the front end of the reinforcing member 40 is joined to the rising portion 38a of the lock R/F 38, and the rear end of the reinforcing member 40 is joined to the door outer 20. Note that, as described above, the lock R/F 38 is joined to the door inner 22. Therefore, it can be said that the front end of the reinforcing member 40 joined to the lock R/F 38 is fixed to the door inner 22 via the lock R/F 38. By fixing the rear end and front end of the reinforcing member 40 to the door outer 20 and the door inner 22, the reinforcing member 40 functions as a tension member that stretches the back door 14 in the thickness direction between the door outer 20 and the door inner 22. do.

In this example, two reinforcing members 40 are provided with an interval in the vehicle width direction. More specifically, the reinforcing member 40 is provided at the same height as the plate attachment surface 32 and at a position shifted in the vehicle width direction from the center of the back door 14 in the vehicle width direction. By providing the reinforcing member 40 at such a position, vibration of the door outer 20 and the door inner 22 caused by the sound output of the speaker 34 can be effectively prevented. This will be explained in detail below.

As described above, the reinforcing member 40 functions as a tensioning member that extends between the door outer 20 and the door inner 22 in the thickness direction of the back door 14. By providing such a reinforcing member 40, movement of the door outer 20 and the door inner 22 in the thickness direction, and thus vibration, can be effectively suppressed.

Here, a plurality of types of vibrations with different cycles may occur in the door outer 20 and the door inner 22. Among these multiple types of vibrations, the vibration mode with the maximum period is the primary vibration mode, and the vibration mode with the period 1/n of the primary vibration mode is the n-order vibration mode. When comparing the levels of these multiple types of vibrations, the level of the primary vibration mode is usually the highest, followed by the level of the secondary vibration mode. Therefore, when it is desired to suppress abnormal noise caused by vibration, it is most effective to suppress the occurrence of the primary vibration mode and the secondary vibration mode.

The upper part of FIG. 2 shows a vibration waveform W1 in the primary vibration mode and a vibration waveform W2 in the secondary vibration mode. As is clear from FIG. 2, in the primary vibration mode, the center of the back door 14 in the vehicle width direction becomes an antinode of vibration, and both ends of the back door 14 in the vehicle width direction become nodes of vibration. In addition, in the secondary vibration mode, when the back door 14 is divided into four equal parts in the vehicle width direction, the 1/4 point and the 3/4 point are the antinodes of vibration, and the center of the back door 14 in the vehicle width direction and the vehicle width Both ends of the direction become nodes of vibration.

In order to suppress vibration, it is most effective to suppress the movement of the door outer 20 and the door inner 22 near the antinode of such vibration. Therefore, in order to suppress the vibration in the primary vibration mode, a reinforcing member 40 is provided at the antinode position of the vibration in the primary vibration mode, that is, at the center of the back door 14 in the vehicle width direction, and the reinforcing member 40 is provided at the center of the back door 14 in the vehicle width direction. It is most effective to restrict movement in the thickness direction. However, as described above, the center of the back door 14 in the vehicle width direction is the antinode of vibration in the primary vibration mode, and at the same time is a node of vibration in the secondary vibration mode. When the reinforcing member 40 is provided at such a location, vibrations in the primary vibration mode can be effectively suppressed, but vibrations in the secondary vibration mode can hardly be suppressed.

Therefore, in this example, the reinforcing member 40 is attached to either the vibration node of the primary vibration mode (the end of the back door 14 in the vehicle width direction) or the vibration node of the secondary vibration mode (the center of the back door 14 in the vehicle width direction). It is located at a position that is offset from the That is, the reinforcing member 40 is provided at a position spaced apart from the center of the back door 14 in the vehicle width direction. More specifically, in this example, when the vehicle width direction dimension of the back door 14 is DW, the two reinforcing members 40 are placed from the end of the back door 14 in the vehicle width direction to the inner side in the vehicle width direction from DW/4, In addition, it is arranged outward in the vehicle width direction from the center in the vehicle width direction. With this configuration, vibrations in both the primary vibration mode and the secondary vibration mode can be effectively suppressed. As a result, generation of abnormal noise and deterioration of output sound quality of the speaker 34 can be effectively prevented.

Further, such vibrations tend to be large on a flat surface with few irregularities. In the case of the door outer 20, since the plate mounting surface 32 is a flat surface without unevenness, vibrations tend to increase. In this example, since the reinforcing member 40 is provided at the same height position as the plate mounting surface 32, vibrations of the back door 14, particularly vibrations at the plate mounting surface 32, can be effectively suppressed.

In this example, in order to further improve the sound quality of the speaker 34, a sound insulating plate 42 is provided near the boundary between the main body 16 and the frame 18 of the back door 14. The sound insulating plate 42 is a plate material disposed in the door interior space formed between the door inner 22 and the door outer 20, and is a plate material that restricts the passage of sound.

By providing such a sound insulating plate 42 near the boundary between the main body portion 16 and the frame portion 18, outflow of air from the main body portion 16 to the frame portion 18 can be suppressed. Thus, deterioration in the sound quality of the speaker 34 can be suppressed.

That is, the speaker 34 outputs desired sound by vibrating the air. However, if there are many places for air to escape, a portion of the air that has received pressure from the speaker 34 will flow out without being sufficiently vibrated, resulting in a decrease in sound quality. When the sound insulating plate 42 is provided as in this example, there are fewer places for air to escape, so the air around the speaker 34 can be appropriately vibrated, and deterioration in the sound quality of the speaker 34 can be effectively prevented.

Note that, in order to effectively prevent sound quality deterioration, it is desirable that the sound insulating plate 42 firmly fills the gap between the door outer 20 and the door inner 22. Therefore, in this example, the sound insulating plate 42 is made of a foam material 46 that foams and expands when heated. Specifically, the sound insulating plate 42 includes a stay reinforcement 44 joined to the door inner 22 and a foam material 46 held by the stay reinforcement 44, as shown in FIG. The door inner 22 is joined to the door outer 20 with the stay reinforcement 44 joined. After the door outer 20 and the door inner 22 are joined, the back door 14 is heated, so that the foam material 46 foams and expands to appropriately fill the gap between the door outer 20 and the door inner 22. In addition, in FIG. 4, the two-dot chain line indicates the shape of the foam material 46 before foaming. By configuring the sound insulating plate 42 with the foam material 46 in this manner, the gap between the door outer 20 and the door inner 22 can be easily and appropriately filled, and in turn, deterioration of the sound quality of the speaker 34 can be effectively prevented.

Note that the configuration described so far is an example, and as long as the two reinforcing members 40 are provided at a position separated from the center in the vehicle width direction with an interval in the vehicle width direction, other configurations may be used as appropriate. May be changed. For example, if the reinforcing member 40 is to be stretched between the door outer 20 and the door inner 22, its shape and configuration may be changed as appropriate. For example, the front end of the reinforcing member 40 may be directly joined to the door inner 22 instead of the lock R/F 38. Further, the rear end of the reinforcing member 40 may be fixed to the door outer 20 via another member. Further, in the above description, the sound insulation board 42 is provided, but the configuration of the sound insulation board 42 may be changed as appropriate, or the sound insulation board 42 may not be provided.

10 vehicle, 12 back door opening, 14 back door, 16 main body, 18 frame, 20 door outer, 22 door inner, 26 rear window, 30 license plate, 32 plate mounting surface, 34 speaker, 35 speaker hole, 36 lock mounting hole , 38a rising portion, 38b flange portion, 40 reinforcing member, 42 sound insulating plate, 44 stay reinforcement, 46 foam material.

Claims (1)

a back door having a door inner and a door outer joined to the door inner;
a speaker attached to the door inner;
a reinforcing member having one end directly or indirectly fixed to the door inner, the other end directly or indirectly fixed to the door outer, and extending in the door thickness direction between the door inner and the door outer;
The reinforcing members are provided in two spaced apart in the vehicle width direction,
Each reinforcing member is provided at a position spaced apart from the center of the back door in the vehicle width direction,
A backdoor structure characterized by:

Images