JPH042864Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) This invention relates to the side shape of a differential accommodating portion for accommodating a differential (hereinafter referred to as differential) of an automobile.

(Prior Art) As shown in FIG. 4, the side surface of a conventional differential accommodating portion 4 provided on the floor of an automobile for accommodating the differential 3 has a concave shape with a vertical step in front and behind the differential 3. With such a shape, when the car is running, almost no airflow flows into the differential accommodating part 4, and only a weak vortex is generated within the differential 3.
has the disadvantage that it is not cooled sufficiently.

In order to eliminate the drawback of the cooling effect of the differential housing part 4 shown in FIG. 4, there is an air scoop 5 attached to the front lower part of the differential housing part 4 as shown in FIG.
However, when the air scoop 5 is attached, wind flows around the differential 3, and although the cooling effect is improved to some extent, there is a drawback that a strong vortex is generated behind the differential 4, increasing air resistance.

In addition, as a prior art document of the present application, there is Utility Model Application Publication No. 183270/1989 filed by the present applicant.

(Problems to be Solved by the Invention) The object of this invention is to provide an underfloor of an automobile that has a large cooling effect on the differential and hardly causes an increase in resistance.

(Means for Solving the Problems) In order to solve the above problems, this invention has the side shape of the differential housing section upward at an inclination angle of 10° to 30° from the lower surface of the floor in front of the differential to the intermediate floor above the differential. The rear end of the intermediate floor is connected to the rear floor through a step less than 1/2 of the height from the lower surface of the floor to the intermediate floor.

(Function) Due to the side surface shape of the differential accommodating portion described above, airflow flows along the lower surface of the differential accommodating portion when the vehicle is running, so that the differential is sufficiently cooled. Moreover, since almost no eddies that cause air resistance occur downstream of the differential, resistance does not increase.

(Description of Embodiments) This invention will be explained below with reference to drawings showing embodiments. Note that the same components as in FIGS. 4 and 5 are given the same numbers and their explanations will be omitted. In Figure 1, 10° to the floor lower surface 6 in front of the differential 3
An inclined surface 1 having an inclination angle θ of 30° is formed, and the inclined surface 1 connects to an intermediate floor 2 located above the differential 3 and approximately parallel to the floor lower surface 6.
is connected to the lower rear floor 8 via a step 7. When the height from the floor lower surface 6 to the intermediate floor 2 is H, and the height from the rear floor 8 to the intermediate floor 2 is h, h/H is set to <0.5.

Incidentally, the air flow velocity v and the resistance coefficient Cd in the differential housing portion 4 are functions of the aforementioned h/H and the inclination angle θ. Figure 2 shows the value of the air flow velocity v with respect to the inclination angle θ at a constant value when h/H<0.5,
The smaller the inclination angle θ, the greater the flow velocity v. FIG. 3 shows variations in the air flow velocity v and the drag coefficient Cd in the differential housing section 4 with respect to h/H, assuming that the inclination angle θ is constant when 10°<θ<30°. From Figure 3, the present application is h/
When H<0.5, only the conventional differential housing 4 is used (marked with ★ in the figure), and the air scoop 5 is installed in the differential housing 4.
It can be seen that the flow velocity v is larger than when the air scoop 5 is attached to the differential housing section 4 (indicated by a circle in the figure), and the resistance coefficient Cd is smaller than when the air scoop 5 is attached to the differential housing section 4. In particular, in order to enhance the cooling effect on the differential 3, it is necessary to increase the flow velocity v, and for this reason, it is desirable that h=0.

(Effects of the invention) Since this invention has the above-mentioned configuration, the flow velocity of the air passing through the differential is increased, and the cooling effect on the differential is improved compared to the conventional one, and it has the effect of not increasing air resistance.

[Brief explanation of the drawing]

FIG. 1 shows a side view of an embodiment of this invention.
Both FIG. 2 and FIG. 3 show characteristic diagrams of the effects of this invention. 4 and 5 both show side views of a conventional differential housing section. 1... Inclination angle, 2... Intermediate arrow, 3... Differential, 4... Differential housing section, 6... Bottom surface of floor, 7...
...step, 8...rear floor.

Claims (1)

[Scope of utility model registration request] The side shape of the differential housing section is tilted upward at an inclination angle of 10° to 30° from the lower surface of the floor in front of the differential to the intermediate floor above the differential, and the rear end of the intermediate floor is 1 1/2 in height from the lower surface of the floor to the intermediate floor. An underfloor of an automobile, characterized in that it is connected to the rear floor through a step of less than /2.