KR20020044491A - Roof rack carrier for an automobile - Google Patents

Abstract

PURPOSE: A roof rack carrier is provided to enhance the silence in an interior of a vehicle by rapidly scattering a turbulent flow generated in a rear stream of an X-bar caused by wind by varying a sectional shape of the X-bar. CONSTITUTION: A concave part(22a) and a protruding part(22b) are formed at an upper surface(22) of a rear X-bar(20). A lower protruding part(24a) is formed at a lower surface of the rear X-bar(20) so as to increase the flux of air. A roof panel(1) is installed at a lower portion of the lower surface(24) of the rear X-bar(20), so the rear X-bar(20) forms a duct together with the roof panel(1). Air passing through the lower protruding part(24a) flows into a gap formed between the lower surface(24) of the rear X-bar(20) and the roof panel(1). The flux of air is decreased at the gap. Air flowing through an air route is branched at a trailing edge formed at a rear portion of the rear X-bar(20).

Description

ROOF RACK CARRIER FOR AN AUTOMOBILE}

The present invention relates to a roof rack carrier for a vehicle, and more particularly, to a roof rack carrier for a vehicle formed so that the cross-section of the X-bar is asymmetrically the upper surface and the lower surface with respect to the center line.

In modern life, in addition to the unique transportation function, the vehicle has the function of effectively transporting various equipment necessary for outdoor leisure and sports activities, and for this purpose, the RV vehicle is equipped with various convenience devices.

In particular, in the case of RV vehicles, the bench-type rotation that can change the opposite position of the seat in the front and rear directions, as well as the double folding seat which can be operated with the seat temporarily folded to increase the utilization of the leisure space and to secure the loading space. Adopt a sheet. In addition, the roof rack carrier as shown in FIG. 1 is provided in the roof so that skis or cargo can be bundled and carried. In the overall configuration of the roof rack carrier, the front roof rack cross bar (hereinafter, front) is connected between the roof rack rails 2 extending in the longitudinal direction of the vehicle and the left and right directions between both roof rack rails 2. A crossbar) 4 and a rear rear roof rack X-bar (hereinafter referred to as a rear X-bar) 10. The front roof bar 4 is provided with a sunroof 8 for indoor ventilation.

2 shows a cross section of a conventional rear X-bar 10. As shown here, the rear X-bar 10 consists of an upper surface 12 of a slightly protruded shape and a lower surface 14 of a flat string shape. Therefore, the traveling wind flowing in the arrow direction P1 from the front along the upper surface is peeled off at the end of the upper surface 12, and the traveling wind flowing into the arrow direction P2 from the front along the lower surface is the lower surface. By peeling off at the end of (14), a vortex shedding V1 is generated at the same period behind the X-bar 10. At this time, the generated vortex gradually increases as it flows backward (Vn), causing pressure disturbance (noise) on the surface of the X-bar and the roof panel (1). This noise is a cause of deterioration of the quietness of the room because the driver and passengers can clearly feel even at the commercial speed range of 70 ~ 110km / H.

The present invention for solving the above problems is to change the cross-sectional shape of the X-bar quickly dissipates the vortex generated in the wake of the X-bar by the running wind flowing from the front during the high-speed driving of the vehicle to quiet the interior It is an object of the present invention to provide a vehicle roof rack carrier that can be improved.

1 is a perspective view showing the configuration of a typical vehicle roof rack carrier,

Figure 2 is a cross-sectional view showing the structure of a conventional rear X-bar,

Figure 3 is a cross-sectional view showing the structure of the rear X-bar of the present invention,

4A to 4D are graphs showing changes in indoor sound generated at vehicle speeds.

[Explanation of symbols on the main parts of the drawings]

1: roof panel 2: carrier

20: cross bar 22: upper surface

22a: recess 22b: protrusion

24: bottom surface 24a: bottom projection

The vehicle roof rack carrier of the present invention for achieving the above object is a roof rack rail disposed to extend in the longitudinal direction to the roof panel of the vehicle, the front front cross bar is connected to the left and right directions between both roof rack rails and In the vehicle roof rack carrier comprising a rear rear X-bar, the rear X-bar is characterized in that the cross-sectional shape of the upper surface and the lower surface is asymmetric.

Hereinafter, a roof rack carrier for a vehicle according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 3 and 4.

Figure 3 is a cross-sectional view showing the structure of the rear X-bar of the present invention, Figure 4a to 4d is a graph showing the change in the room sound generated for each vehicle speed.

First, as shown in FIG. 3, a rear X-bar 20 is installed in the roof panel of the vehicle, which is connected in both directions between both roof rack rails. In the preferred embodiment of the present invention, the cross-sectional shape of the X-bar is formed to be asymmetric with respect to the center line in the horizontal direction in order to dissipate the vortex generated in the wake of the X-bar.

To this end, a recess 22a and a protrusion 22b are formed on the upper surface 22 of the rear X-bar 20 to provide an upper peeling point, and a lower protrusion 24 on the lower surface 24 increases the flow velocity. 24a) was formed. Therefore, the air blown from the front while traveling moves along the arrow Q1 while passing through the area 30 indicated by the dotted line on the protrusion 22b of the upper surface 22, and thus the flow separation occurs. On the other hand, since the roof panel 1 is disposed below the lower surface 24, the rear X-bars 20 form a kind of duct together with the roof panel 1. At this time, the air blowing from the front is not generated by the flow of the lower protrusion (24a) formed in front of the lower surface 24 is to exit the gap at high speed due to the pressure drop. The air exiting the lower protrusion 24a gradually decreases in the section in which the area of the gap formed by the lower surface 24 of the X-bar 20 and the roof panel 1 gradually increases. This progressing air travels along arrow Q2, where a split occurs at the trailing edge behind X-bar 20.

That is, strong vortices are generated at the upper part of the X-bar 20 by the asymmetric upper and lower surfaces 22 and 24, due to the accelerated flow dividing, and at the lower side, weak vortices are caused by the decelerated flow rate. It is divided (V1 '). In addition, since the upper and lower surfaces of the X-bar 20 are different, the distance between the peeling points from the leading leading edge of the front is different, and thus the vortex separation frequency of the upper and lower surfaces is different from each other. Therefore, the vortex division of the wake is dissipated rapidly by dissipation with different vortices and different sensitivity.

4A to 4D are graphs showing changes in indoor sound generated at 80 km / H, 110 km / H, 150 km / H, and 180 km / H, respectively. The solid line in these graphs represents the change in noise generated by the conventional X-bar loop carrier described in FIG. 2, and the dashed line represents the change in noise generated by the loop carrier with X-bar of the present invention described in FIG. Indicates. As can be seen here, in the case of a vehicle equipped with a conventional roof carrier, a peak is generated as shown by an arrow and the noise is increased, whereas in the case of a vehicle equipped with a loop carrier of the present invention, a peak is not generated. It can be seen that the noise is reduced. The Y axis in the graph represents noise.

According to the present invention described above, by changing the cross-sectional shape of the X-bar so that the upper surface and the lower surface is asymmetrical with respect to the center line is generated in the wake of the X-bar by the driving wind flowing from the front at high speed of the vehicle Dissipation of the vortex quickly has the advantage of improving the quietness of the vehicle interior.

Claims (2)

In a roof rack carrier for a vehicle comprising a roof rack rail arranged to extend in a longitudinal direction to a roof panel of a vehicle, and a front front cross bar and a rear rear X-bar connected to the left and right directions between both roof rack rails, The rear X-bar 20 is a vehicle roof rack carrier, characterized in that the cross-sectional shape of the upper surface (22) and the lower surface (24) is asymmetric. The method of claim 1, The upper surface 22 of the rear X-bar 20 has a recess 22a and a protrusion 22b for providing an upper peeling point, and a lower protrusion 24 for increasing the flow velocity in the lower surface 24 thereof. A roof rack carrier for a vehicle, characterized in that 24a) is formed.