JPH0717173B2 - Car roof structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a roof structure of an automobile capable of reducing muffled noise in a vehicle interior.

[Prior Art] Generally, in an automobile, the roof thereof is a roof panel made of an iron plate, and a molded ceiling material made as a single piece along the panel surface is arranged below the roof panel.

FIG. 6 shows an example of the roof structure of the conventional automobile.

In the figure, the roof panel 30 is fixed to the outer panel 33, which is the upper surface side of the roof side rails 32 provided on both the left and right sides of the roof, via drip channels 31 on both the left and right sides, and the front and rear sides are not shown as front roof rails. It is fixed to each of the rear roof rails, and is attached so as to cover the upper part of the passenger compartment.

On the other hand, the molded ceiling material 34, which is formed as a rigid single piece in a roof shape along the inner surface of the roof panel 30, has an outer peripheral portion 34.
The a is disposed below the roof panel 30 in a state of being in surface contact with the inner panel 35 that is the lower surface of the side rail 32. Then, after that, screws 3 are formed in the through holes 34b formed on the molded ceiling material 34 side so as to correspond to the through holes 35a on the inner panel 35 side.
9 is commonly screwed and fixed. Further, from below the outer peripheral portion 34a, the portions fixed with the screws 39 are covered with the garnish 36 attached to the inner panel 35, and the fixed portions are hidden from the outside.

The garnish 36 is formed of a resin material in a rail shape, and the inner surface of the garnish 36 is a bulging portion 37 that is snap-in engaged with an engagement hole provided on the inner panel 35 side.
A locking pin 37 having a at the tip is integrally provided.
The garnish 36 is arranged along each side of the molded ceiling material. Then, at each side portion, the one side portion 36a is brought into contact with the roof side rail 32 via the seaming welt 38, and the molded ceiling material 34 is formed.
With the other side portion 36b abuttingly arranged on the lower side of the
The 7a are snap-in engaged with the engagement holes on the inner panel 35 side and attached.

[Problems to be Solved by the Invention] By the way, in a vehicle, various noises intrude into the vehicle interior from the outside. Of these, engine noise is of particular concern, and this engine noise is emitted during driving. In addition, engine noise generally increases with vehicle speed, and also suddenly increases at a certain vehicle speed, which may cause a resonance phenomenon with a feeling of being muffled. This is what is called the cavity resonance in the passenger compartment, or "muffled noise," and the frequency is low, 30 to 20.
Although it was about 0 Hz, there was a problem that the sound was loud and made uncomfortable and made the ride uncomfortable. Further, the above-mentioned conventional roof structure is relatively simple and capable of absorbing vibrations in a high frequency region of approximately 1 KHz or more, and is not a structure capable of effectively absorbing these vibrations in a low frequency region which cause muffled noise. For this reason, conventionally, a structure capable of absorbing and removing the muffled sound has been desired.

The present invention has been made in view of the above problems, and an object of the present invention is to quickly absorb vibration energy that is noise generated by entering a vehicle interior and eliminate muffled noise to improve riding comfort. To provide a roof structure for an automobile.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a roof structure for an automobile, which covers an inner surface of the roof panel of the automobile and has a molded ceiling material disposed below the roof panel. And the molded ceiling material is attached to one side surface of the molded base material, the molded base material being divided into an outer peripheral fixed portion and a central portion that is vertically movable relative to the outer peripheral fixed portion, and the outer peripheral fixed portion. And a skin that connects the central part to each other, the outer peripheral fixing part is fixed to the roof panel, and the central part is suspended from the roof panel via an elastic body.

[Operation] According to this structure, when vibration due to noise occurs in the vehicle interior, bending due to flexure of the skin portion connecting the outer peripheral fixing portion and the central portion of the molded base material, and elasticity. The central part vibrates with the vibration of. Then, due to the vibration by the elastic body, the vibration energy such as noise generated on the passenger compartment side is sequentially absorbed, and the vibration energy which is not absorbed by the elastic body is transmitted to the roof panel and spreads to the other elastic body parts. Is absorbed again. This reduces muffled noise.

EXAMPLES Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an external perspective view showing a roof portion of an automobile to which an embodiment of the present invention is applied, and FIG. 2 is a schematic enlarged sectional view taken along the line II-II in FIG.

1 and 2, a passenger compartment 2 of an automobile 1
(See FIG. 2) is covered with a roof panel 3 and a molded ceiling material 4 arranged below the roof panel 3.

The roof panel 3 is formed of an iron plate, and the left and right side portions of the roof panel 3 are fixed to the outer panel 6 which is the upper surface side of the roof side rail 5 via drip channels 7, and the front and rear front rails are not shown. And the rear roof rail are fixed to the passenger compartment 2
It is attached to cover the upper part of.

On the other hand, the molded ceiling material 4 is composed of a molded base material 20, a skin 21, and the like. The molding substrate 20 is made of, for example, a range felt molded product or cardboard, and is provided with an outer peripheral fixing portion 22 fixed to the roof side rail 5 below the outer peripheral portion of the roof panel 3. It is composed of a central portion 23 formed independently of the outer peripheral fixing portion 22. The outer peripheral fixing portion 22 is formed in a frame shape having an opening at the center and a plurality of through holes 24 (see FIG. 3) provided in the periphery, and the central portion 23 is an opening portion of the outer peripheral fixing portion 22. It is formed slightly smaller than the opening so as to fit inside. As a result, when the central portion 23 is housed in the opening portion, the gap X is formed over the entire circumference between the central portion 23 and the outer peripheral fixing portion 22. Next, the skin 21 is made of, for example, soft urethane foam and a vinyl chloride sheet, and is commonly attached to the entire lower surface of the outer peripheral fixing portion 22 and the entire lower surface of the central portion 23 of the molding substrate 20. In addition, by this attachment, the outer peripheral fixing portion 22 and the central portion 23 are connected to each other so that they can move in the vertical direction, so that a molded ceiling material 4 of one piece having a roof shape along the inner surface of the roof panel 3 is formed. Are formed. Further, although not shown, the molded ceiling material 4 is provided with through holes and cutouts corresponding to the portions to which room lamps, inner mirrors, etc. are attached. Then, the molded ceiling 4 is arranged below the roof panel 3 and then attached in a state where the central portion 23 is suspended from the roof panel 3 via the elastic body 8. At the same time, the outer peripheral fixing portion 22 is fixed to the roof panel 3 side via the screws 14 which are screwed to the inner panel 11 of the roof side rail 5 through the through holes 24 so that both side portions 22a, 22a of the through holes 24 are fixed.
The front side portion 22b and the outer side portion 22c of the outer peripheral fixing portion 22 are fixed to the front roof rail and the rear roof rail (not shown) using the same screws. Further, the elastic body 8 suspending the central portion 23 on the roof panel 3 is formed into a rod shape as shown in FIG.
A total of three are arranged along the front-back direction. A rubber or the like is used as the elastic body 8, but a relatively low noise level of 30 to 200 H that causes a muffled sound inside the vehicle interior 2 due to noise.
The central portion 23 is set in a state in which it can vibrate when a low frequency sound of about z is generated. Further, the elastic body 8 is provided at a position close to the outer peripheral portion of the central portion 23 so that the central portion 23 does not droop downward greatly together with the outer skin 21 and the appearance is deteriorated.

Next, the molded ceiling material 4 arranged below the roof panel 3
A garnish 10 formed of a resin material in the shape of a rail is disposed on the lower side. Further, on the inner surface of the garnish 10, a locking pin 12 having a bulge portion 12a at the tip which is snap-in engaged with an engagement hole penetrating to the inner panel 11 side is integrally formed. ing. The garnish 10 is arranged along each side of the molded ceiling material 4, and one side portion 10a is brought into contact with the roof side rail 5 via the seaming welt 13 and the other side at each side portion. The portion 10b is disposed in contact with the lower surface of the molded ceiling material 4, and in this state, the bulging portion 12a is inserted into the engagement hole on the inner panel 11 side.
Are snap-in engaged and attached respectively.

In the roof structure of the automobile configured as described above, the central portion 23 of the molded ceiling member 4 and the elastic body 8 are stationary or in a state in which vibration such as muffled noise is not generated inside the vehicle interior 2. It is in a state close to. Next, when engine noise or the like occurs in the passenger compartment 2, the vibration causes the central portion 23 of the molded ceiling member 4 to bend and deform the outer skin 21 and the elastic body 8.
It vibrates up and down with elastic deformation. Then, the vibration energy generated in the vehicle interior 2 by the vibration of the elastic body 8 is absorbed by the elastic body 8. Further, the vibration energy not absorbed by the elastic body 8 is transmitted to the roof panel 3 and spreads,
The other elastic body 8 is sequentially absorbed.

Therefore, in the roof structure of this automobile, the noise inside the passenger compartment 2, especially the sound in the low frequency range is sequentially absorbed by the periodic vibration of the central portion 23 of the molded ceiling member 4 and the elastic body 8,
The muffled noise can be eliminated. This improves the riding comfort.

It is needless to say that the present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the gist thereof.

For example, as shown in FIG. 4 to FIG. 5, a state in which a plurality of (5 in the modified example) are formed in a columnar shape extending in the vertical direction from an elastic body of a square member in which the elastic body 8 is laid down It may be placed on the central portion 23. More specifically,
The elastic body 8 shown in FIGS. 4 and 5 includes a cushion portion 8a formed of a rubber material in a cylindrical shape, and end covers 8b and 8c attached to cover the upper and lower surfaces of the cushion portion 8a. Furthermore, a string is passed through the inside of the cushion portion 8a and between the end lids 8b and 8c.
8d is provided. In this elastic body 8, an end cover 8b is fixed in contact with the inner surface of the roof panel 3 and an end cover 8c is fixed in adhesive to the rear surface of the central portion 23. The central portion of the roof panel 3 is elastically displaced with respect to the roof panel 3.
When 23 vibrates up and down, the amount of amplitude can be regulated by the string 8d.

[Effects of the Invention] As described above, according to the roof structure for a vehicle according to the present invention, when noise is generated in the vehicle interior, the skin that connects the outer peripheral fixing portion and the central portion of the molded base material. The central portion periodically vibrates with the bending due to the bending of the portion and the vibration of the elastic body. And with the vibration by this elastic body,
Sound energy such as noise generated in the passenger compartment is sequentially absorbed, and sound energy not absorbed by the elastic body spreads to the roof panel and is absorbed again by other elastic body parts, so muffled noise is reduced. Can be reduced. This improves the riding comfort.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a roof portion of an automobile to which an embodiment of the present invention is applied, FIG. 2 is a schematic enlarged sectional view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a top view showing a modified example of the above main part shown in FIG. 3, FIG. 5 is an enlarged sectional view taken along line VV in FIG. 4, and FIG. It is sectional drawing which showed the principal part of the roof part in the conventional vehicle. 3 …… Roof panel 4 …… Molded ceiling material 8 …… Elastic body 20 …… Molded base material 21 …… Skin 22 …… Perimeter fixed part 23 …… Center part

Claims (1)

[Claims] 1. A roof structure for an automobile in which a molded ceiling material is disposed below the roof panel so as to cover an inner surface of the roof panel of the automobile, wherein the molded ceiling material includes an outer peripheral fixing portion and the outer periphery. A molding base material divided into a central portion that is vertically movable with respect to the fixing portion, and a skin that is attached to one side surface of the molding base material and that connects the outer peripheral fixing portion and the central portion to each other. A roof structure for an automobile, comprising: the outer peripheral fixing portion fixed to the roof panel, and the central portion suspended from the roof panel through an elastic body.