JPH0628430Y2 - Fuel tank sound deadening structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a sound deadening structure for a fuel tank mounted on a vehicle.

(Prior Art) Conventionally, as a sound deadening structure of a fuel tank for eliminating fuel rocking noise (chapo / chapo sound) during traveling, for example, a structure described in Japanese Utility Model Publication No. 54-22807 is known. Similar schematic structures are shown in FIGS. 9 and 10. That is, a baffle plate 103 made of a steel plate is vertically provided in the fuel tank main body 101 made of a steel plate, and the baffle plate 103 is supported by a mounting flange 105 fixed to an upper wall surface 107 in the fuel tank main body 101. ing. Thus, by controlling the rocking motion of the fuel generated at the time of starting and braking of the vehicle by the baffle plate 103, the rocking noise (chapo sound) of the fuel in the fuel tank main body 101 can be suppressed to a low level. ing.

(Problems to be Solved by the Invention) As described above, the rocking motion of the fuel is caused by the baffle plate 103.
Mounting flange 105 and upper wall surface 10
The load concentrates on the attachment part with 7. Therefore, in order to prevent the occurrence of cracks in the mounting portion due to the load, it is necessary to take measures such as increasing the plate thickness of the fuel tank main body 101 or providing a reinforcing material. It was

On the other hand, there has been conventionally known a structure in which a fuel tank body made of a synthetic resin and a baffle plate are integrally molded to reduce the weight.

This fuel tank made of synthetic resin is generally molded by blow molding, but at the root of the baffle plate that is continuous with the fuel tank main body, the synthetic resin material does not work well or partially. Molding control was very troublesome because it became too large. Also, in some cases, problems such as the failure to obtain a specified wall thickness may occur.

Further, in the suspension type in which the baffle plate 103 is vertically suspended from the upper wall surface 107, when the fuel level is full and the liquid level rises, for example, the so-called noise that occurs when the fuel moves forward during braking is suppressed. Therefore, it is difficult to suppress the squeaking and the squeaking noise that hit the upper wall surface 107 due to the waving during traveling.

Particularly in a four-wheel drive vehicle that runs off-road, it is necessary to pay attention to the mounting position of the fuel tank, so that the fuel tank tends to be arranged on the lower surface of the floor panel of the rear seat, for example. For this reason, the size of the fuel tank is limited, and thus the fuel tank is thin and has a large cross-sectional area so as to ensure a large capacity. Therefore, the rocking noise and other noises such as rustling noise and humming noise are transmitted to the interior of the vehicle, leaving a problem in terms of quality. Therefore, as a means for solving such a problem, for example, one in which a second baffle plate is provided on the upper wall surface 107 of the fuel tank main body is known, and although some effects are obtained, a normal baffle plate is obtained. The second baffle plate has to be provided outside the above, and the number of parts increases. For this reason, the number of man-hours for managing parts has been increased, which is not desirable in terms of assembling. In addition, it causes problems such as cost increase.

In view of this, the present invention is directed to the fuel rocking noise, and the noise reduction structure of the fuel tank that can suppress the squeaking noise and the thud noise that hit the upper wall surface of the fuel tank main body without providing the second baffle plate. Is intended to provide.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention has a large number of surface-opened voids over the entire circumferential surface, and moves up and down corresponding to the fuel liquid level. A baffle plate having buoyancy is rotatably suspended and supported by a mounting bracket provided on the upper wall surface of the fuel tank body.

(Operation) According to such a sound deadening structure of the fuel tank, the free end side of the baffle plate moves up and down in response to the vertical movement of the fuel level, so, for example, when the liquid level is at the intermediate position of the fuel tank body, Since the plate is suspended in the vertical direction, the waves generated at the time of starting and braking are dispersed and extinguished by the large number of voids in the baffle plate, and the rocking noise (chappo noise) can be suppressed to a low level.

Further, when the liquid level rises and the tank is full, the baffle plate is in a posture of approaching to the upper wall surface side of the fuel tank main body, so that the baffle plate is pressed against the upper wall surface side by waves generated during braking, for example. At this time, the waves that collide with the upper wall surface side are dispersed by the large number of voids in the baffle plate that are pressed against the upper wall surface side, and the trapped air layer serves as a cushion to suppress the noise. Further, at least in the area of the baffle plate, there will be no squeaking noises that hit the upper wall surface. As a result, only one baffle plate can be used. In addition, since the baffle plate has buoyant force that moves up and down according to the liquid level of the fuel, concentrated load does not act on the mounting part of the mounting bracket, and it is possible to omit the reinforcing member and reduce the wall thickness. Will contribute to the realization.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings of FIGS. 1 to 7. In the figure, reference numeral 1 denotes a steel plate fuel tank. A fuel tank main body 3 of the fuel tank 1 is composed of an upper shell 5 and a lower shell 7, and peripheral flanges of the shells 5 and 7 are superposed and joined. The fuel tank main body 3 has a shape provided on the lower surface of the floor panel in the rear seat of a four-wheel drive vehicle, for example, and the upper shell 5 has a wide range that is gradually inclined forward and upward so that the seat cushion is placed. It has a wall surface 9.

In the fuel tank main body 3, the baffle plate 17 is provided outside the intake 11a of the evaporation tube 11, the intakes of the ventilation tube 13, the fuel filler tube 15, and functional parts such as an oil gauge (not shown). Is provided.

The baffle plate 17 is formed in a loop shape, and is suspended from the upper wall surface 9 in the fuel tank body 3 by a mounting bracket 19 formed in a bar shape.

From the flange portion 21 of the mounting bracket 19 to the flange portion 2
The mounting width D of the mounting portion 23 up to 1 is set to be slightly smaller than the width of the fuel tank body 3, and the left and right flange portions 2
1.21 is fixed to the upper wall surface 9 by welding or the like.

The baffle plate 17 has a mounting width D of the mounting bracket 19.
The mounting means is set to be substantially the same as the above, and after hanging the bar-shaped mounting portion 23 when forming a loop, the both ends are connected by the clip 25 made of resin or the like to be the hanging means. . Further, the baffle plate 17 is made of a mesh of resin wire rods 27 close to the specific gravity of the fuel as shown in FIG. 5, and when viewed from the direction of arrow A in FIG. The ridgeline of the mountain is continuous at intervals and has a surface wavy shape. When viewed from the direction of arrow B in the figure,
The resin wire rods 27 are in a crossed state with a substantially uniform thickness. As a result, the baffle plate 17 has a constant thickness, and a large number of voids 2 having different surface opening sizes.
It is configured to have 9.

The void 29 has a function of providing a buoyancy effect by creating a large number of air layers (rooms) by the fuel film when the baffle plate 17 faces the fuel, and disperses and dissipates the energy of waves generated during traveling. It has the function to do.

The void density and the thickness of the baffle plate 17 can be appropriately selected.

In the sound deadening structure of the fuel tank 1 configured as described above, the baffle plate 17 rises in accordance with the rise of the liquid level at the time of fuel injection, and when the liquid level is lowered by the consumption of fuel, the baffle plate 17 is lowered corresponding to the fall. Come to do.

Therefore, for example, when the liquid surface is in the middle, the baffle plate 17 is in a posture of being suspended in the vertical direction, and the waves generated at the time of starting or braking are dispersed and extinguished by the large number of voids 29 in the baffle plate to cause a rocking noise ( The chirp / chapp sound) can be kept small. On the other hand, when the liquid level rises and the tank is full, the baffle plate 17 is in a posture in which it is close to the upper wall surface 9 of the fuel tank body 3. In this case, since the baffle plate 17 is hung and supported by the mounting bracket 19, the baffle plate 17 smoothly rises in response to the rise of the liquid level and is in a floating state, so that a concentrated load is not applied to the mounting portion of the mounting bracket 19. Does not work. Next, for example, the baffle plate 17 causes the upper wall surface 9 to move due to waves generated during braking.
It is pressed to the side. At the same time, the waves colliding with the upper wall surface 9 side are dispersed and extinguished by a large number of air gaps 29, and are trapped, and the air layer serves as a cushion to suppress the noise. Further, in the area of the baffle plate 17, there will be no squeaking noises that hit the upper wall surface 9. As a result, only one baffle plate 17 can be used. On the other hand, since the running noise is often generated in the front corner region W of the fuel tank body 3 due to a sudden stop or the like, for example, by providing the mounting position of the baffle plate 17 toward the front as shown in FIG. More efficient silencing can be obtained.

In this case, the baffle plate 17 responds to the rise of the liquid level.
Mounting bracket 1 so that the free end side of the
This is achieved by giving the mounting portion 23 of 9 a taper to the front by giving a taper.

The baffle plate 17 may have a plate shape instead of a loop shape as shown by the chain line in FIG. 2, and the free end side may move up and down corresponding to the vertical movement of the liquid surface with the mounting portion 23 of the mounting bracket 19 as a fulcrum. Good.

Further, the baffle plate 17 may be configured such that a large number of resin needle materials 33 are planted in a base 31 having a large number of air layers for ensuring buoyancy as shown in FIG.

In this case, with the base 31 inside, the baffle plate 1
Since 7 is formed into a loop and connected by the pin 35, the resin needle material 33, which serves as a sound deadening surface, is required to be formed on only one surface of the base 31, thus facilitating processing.

[Effects of the Invention] As described above, according to the sound deadening structure of the fuel tank of the present invention, the baffle plate has a large number of surface-opened voids over the entire peripheral surface, and the baffle plate is vertically moved in correspondence with the fuel liquid level. Since it has a structure with moving buoyancy, it is possible to suppress the swaying noise (chapo / chapo sound) during running as well as the rustling noises and pica noises. Moreover, there is only one baffle plate. Can be dealt with. Therefore, it is very favorable in terms of processing, parts management, and cost. Further, since a concentrated load does not act on the mounting portion of the mounting bracket, it is possible to reduce the thickness of the mounting portion area and thus reduce the weight.

[Brief description of drawings]

FIG. 1 is a sectional view of a fuel tank embodying the present invention, and FIG.
The drawing is a sectional view similar to FIG. 1 showing the operating state of the baffle plate, FIG. 3 is a perspective view of the entire fuel tank, FIG. 4 is a perspective view in which a mounting bracket and a part of the baffle plate are omitted, and FIG. FIG. 6 is a plan view of a part of the baffle plate, FIG. 6 is a view taken in the direction of arrow A in FIG. 5, FIG. 7 is an enlarged explanatory view of a state in which the mounting position of the baffle plate is near the front, and FIG. FIG. 9 is a sectional view showing another embodiment, FIG. 9 is a sectional view similar to FIG. 1 showing a conventional example of a sound deadening structure, and FIG. 10 is a sectional plan view of the same. 3 ... Fuel tank body 9 ... Upper wall surface 17 ... Baffle plate 19 ... Mounting bracket 29 ... Air gap

Claims (1)

[Scope of utility model registration request] 1. A baffle plate having a large number of surface-opened voids all over the circumference and having a buoyant force that moves up and down corresponding to the fuel liquid level is provided on the upper wall surface side in the fuel tank body. A sound deadening structure for a fuel tank, which is rotatably suspended and supported by a mounting bracket.