Defroster structure

Abstract

To reduce pressure loss and diffusion of blown air in a configuration in which a part of a defroster duct is bent to form a convex shape toward a rear side of a vehicle at a rear of a vehicle frame member.SOLUTION: A defroster structure 10 includes an instrument panel 16 of a vehicle 12, a cowl 20 extending in a vehicle width direction on a vehicle front side of the instrument panel 16, a front windshield 18 whose front end is supported by the cowl 20, and a center defroster duct 30. The defroster duct 30 is bent in a convex manner toward a vehicle rear side at a bent part 30B disposed on the vehicle rear side of the cowl 20, and branches into a front opening 30D and a rear opening 30E in the vehicle front-rear direction at a branching part 30C disposed on a vehicle upper side from the bent part 30B. The front opening 30D and the rear opening 30E open toward the front windshield 18 side at the front end of the instrument panel 16.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a defroster structure of a vehicle.

Background Art

[0002] In the air conditioner for an automobile disclosed in Patent Document 1 below, the defroster outlets of the central duct and the side ducts provided in the defroster device are engaged with the ducts of the defroster grill fitted to the panel body of the instrument panel. The air blown out from the opening of the defroster duct (hereinafter referred to as "defroster opening") is blown against the inner surface of the front windshield supported by the cowl top panel. Thereby, the fog consisting of water droplets adhering to the inner surface of the front windshield is removed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the aforementioned prior art, the defroster opening located on the top surface of the instrument panel is directly in the occupant's field of vision, resulting in poor aesthetics. Furthermore, the reflection of the defroster opening on the front windshield panel obstructs the occupant's forward view, causing annoyance. To address these issues, the defroster opening is sometimes positioned at the front end of the instrument panel. However, to ensure the occupant's forward view, the top surface of the instrument panel must be set low. Additionally, the cowl, a structural component of the vehicle, is located near the front end of the instrument panel. To avoid interference between this cowl and the defroster duct, a portion of the defroster duct must be significantly bent towards the rear of the vehicle at the rear of the cowl. As a result, a large pressure loss occurs in the defroster duct, making it impossible to secure sufficient airflow and velocity. To resolve this, widening the defroster opening presents the problem of diffused airflow.

[0005] The present invention aims to provide a defroster structure that can reduce pressure loss and diffusion of blown air in a configuration in which a part of the defroster duct is bent in a convex manner toward the rear of the vehicle at the rear of the vehicle frame member. [Means for solving the problem]

[0006] The defroster structure of the first embodiment includes an instrument panel of a vehicle, a vehicle frame member extending in the vehicle width direction on the front side of the instrument panel, a front windshield whose front end is supported by the vehicle frame member, and a defroster duct which bends in a convex manner toward the rear of the vehicle at a bent portion located at the rear of the vehicle frame member, and branches in the vehicle longitudinal direction into a front opening and a rear opening at a branching portion located above the bent portion, with the front opening and the rear opening opening toward the front windshield at the front end of the instrument panel.

[0007] In the first embodiment, a vehicle frame member extends in the vehicle width direction on the front side of the vehicle's instrument panel, and the front end of the front windshield is supported by this vehicle frame member. The defroster duct is bent in a convex shape toward the rear of the vehicle at a bend located at the rear of the vehicle frame member, and branches into a front opening and a rear opening in the longitudinal direction of the vehicle at a branch located above the bend. The front and rear openings of the defroster duct open toward the front windshield at the front end of the instrument panel. Because the defroster duct is branched as described above, pressure loss can be reduced compared to a defroster duct with a single opening. Moreover, the airflow velocity from the front opening, which increases due to the Venturi effect, draws in the airflow from the rear opening, thereby suppressing the diffusion of the airflow.

[0008] In the second embodiment of the defroster structure, the inner wall surface on the front side of the rear opening has a curved surface that is curved and convex toward the rear and downward side of the vehicle, as in the first embodiment.

[0009] In the second embodiment, the airflow flowing into the rear opening of the defroster duct can be controlled by the Coanda effect, which causes the airflow to flow along the curved surface, thereby effectively slowing down the airflow blown out from the rear opening. As a result, the aforementioned effect of suppressing the diffusion of the blown air can be improved. [Effects of the Invention]

[0010] As described above, in the defroster structure according to the present invention, a portion of the defroster duct is bent in a convex manner toward the rear of the vehicle at the rear of the vehicle frame member, which reduces pressure loss and diffusion of the blown air. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view showing a defroster structure according to an embodiment. [Figure 2]This is a perspective view showing a defroster duct provided in a defroster structure according to an embodiment. [Figure 3] This is a cross-sectional view showing a portion of the defroster duct. [Figure 4] This is a side view showing the relationship between the defroster structure according to the embodiment and the occupant's line of sight. [Figure 5] This is a side view showing the relationship between the defroster structure and the occupant's line of sight in the first comparative example. [Figure 6] This is a cross-sectional view showing a portion of the defroster duct relating to the second comparative example. [Figure 7] This is a cross-sectional view showing a portion of the defroster duct relating to the third comparative example. [Modes for carrying out the invention]

[0012] The defroster structure 10 according to one embodiment of the present invention will be described below with reference to Figures 1 to 7. The arrows FR, UP, and RH in each figure indicate the forward (direction of travel), upward, and rightward directions of the vehicle, respectively. Hereafter, when simply using the directions of front, rear, left, right, up, and down, it refers to the front, rear, left, right, up, and down directions of the vehicle.

[0013] As shown in Figure 1, the defroster structure 10 according to this embodiment comprises an instrument panel 16, a cowl 20 which is a vehicle frame member, a front windshield 18, and a center defroster duct 30 which is a defroster duct. The instrument panel 16 is molded from, for example, synthetic resin and extends in the vehicle width direction at the front end of the passenger compartment 14 of the vehicle 12.

[0014] The cowl 20 is composed of a cowl outer panel 22 extending in the vehicle width direction (vehicle left-right direction) and a cowl inner panel (not shown) joined to the cowl outer panel 22. The cowl outer panel 22 and the cowl inner panel are manufactured, for example, by press forming of steel plate. Both ends of the cowl outer panel 22 and the cowl inner panel in the vehicle width direction are joined to a pair of left and right cowl sides (not shown). The left and right cowl sides are fixed to a pair of left and right front pillars (not shown) of the vehicle 12. The cowl outer panel 22 and the cowl inner panel constitute a vehicle frame member that connects the left and right front pillars in the vehicle width direction via the cowl sides.

[0015] The cowl outer panel 22 extends in the vehicle width direction along the underside of the front end of the front windshield 18, which is positioned above the instrument panel 16, and supports the front end of the front windshield 18 from below. This cowl outer panel 22 has a support wall 22A that extends along the front windshield 18, an inclined wall 22B that extends diagonally rearward and downward from the rear end of the support wall 22A, and a joining wall 22C that extends rearward from the rear end of the inclined wall 22B. The front end of the front windshield 18 is fixed to the support wall 22A by adhesive 24. The upper end of the cowl inner panel is joined to the joining wall 22C by means of welding or other means.

[0016] As shown in Figures 1 to 3, the center defroster duct 30 constitutes part of a duct structure that guides conditioned air, supplied from an air conditioning unit (not shown) located inside the instrument panel 16, into the passenger compartment 14. A pair of side defroster ducts (not shown) are located on both the left and right sides of the center defroster duct 30.

[0017] The center defroster duct 30 is formed, for example, into a cylindrical shape with a substantially rectangular cross-section by a synthetic resin and is formed longitudinally along the vertical direction. The width dimension in the left-right direction of the center defroster duct 30 is set to be sufficiently larger than the thickness dimension in the front-rear direction of the center defroster duct 30. The lower end portion (not shown) of the center defroster duct 30 is connected to the above-described air conditioner.

[0018] The middle portion in the vertical direction of the center defroster duct 30 is formed into a rearward inclined portion 30A that is inclined toward the rear side as it goes upward. At the upper part of the center defroster duct 30 above the rearward inclined portion 30A, a bent portion 30B that is bent convexly toward the rear side is provided. The bent portion 30B is bent into a substantially U-shape that opens toward the front side of the vehicle in a side view of the vehicle and is disposed behind the cowl outer panel 22. This bent portion 30B is composed of a rearward extension portion 30B1 that extends obliquely upward and rearward from the upper end portion of the rearward inclined portion 30A, an upward extension portion 30B2 that extends upward from the rear end portion of the rearward extension portion 30B1, and a forward extension portion 30B3 that extends forward from the upper end portion of the upward extension portion 30B2.

[0019] At the upper end portion (tip portion) of the center defroster duct 30 that extends forward from the above-described forward extension portion 30B3, a branch portion 30C that bifurcates the upper end portion of the center defroster duct 30 into two in the vehicle front-rear direction is provided. This branch portion 30C is disposed above the bent portion 30B. At this branch portion 30C, the upper end portion of the center defroster duct 30 bifurcates into a front opening portion 30D and a rear opening portion 30E. The front opening portion 30D and the rear opening portion 30E are arranged side by side in the front-rear direction, and the front opening portion 30D is disposed on the front side with respect to the rear opening portion 30E.

[0020] The front opening 30D and the rear opening 30E form a long frame shape with the vehicle width direction as the longitudinal direction when viewed in the vertical direction. The front opening 30D is set to have a larger width dimension in the front-rear direction than the rear opening 30E. The front opening 30D and the rear opening 30E are connected to a center defroster duct connection port (not shown) formed at the front end of the instrument panel 16 and open toward the front windshield 18 side.

[0021] The conditioned air introduced from the air conditioner into the center defroster duct 30 reaches the branch portion 30C through the rearward inclined portion 30A and the bent portion 30B, and blows out from the front opening 30D and the rear opening 30E toward the front windshield 18. Thereby, the fog consisting of water droplets adhering to the inner surface of the front windshield 18 is removed.

[0022] The inner wall surface on the front side in the rear opening 30E has a curved surface 32 that bulges and curves toward the rear and downward. This curved surface 32 is arranged on the root side of the rear opening 30E and is configured such that the conditioned air (airflow) flowing into the rear opening 30E hits the curved surface 32. The blowing air W1 (see FIG. 3) from the front opening 30D increases in flow velocity due to the Venturi effect as the cross-sectional area of the flow path narrows in the front opening 30D. On the other hand, the blowing air W2 (see FIG. 3) from the rear opening 30E is decelerated by the Coanda effect in which the airflow flowing into the rear opening 30E flows along the above-mentioned curved surface 32. Thereby, the flow velocity of the blowing air W1 from the front opening 30D is configured to be faster than the flow velocity of the blowing air W2 from the rear opening 30E. In FIG. 3, the conditioned air is shaded. In FIG. 3, the darker the shaded area, the higher the pressure of the conditioned air.

[0023] In the defroster structure 10 with the above configuration, the upper surface of the instrument panel 16 is set low in order to ensure the occupant's forward visibility. In addition, the front opening 30D and rear opening 30E of the center defroster duct 30 are positioned at the front end of the instrument panel 16 in order to make them less likely to be in the occupant's field of vision. Furthermore, in order to avoid interference between the center defroster duct 30 and the cowl 20, a large curved portion 30B is formed on the upper part of the center defroster duct 30 behind the cowl outer panel 22, with a convex shape towards the rear.

[0024] (Mechanism of Action and Effects) Next, the operation and effects of this embodiment will be described.

[0025] In this embodiment, a cowl 20 extends in the vehicle width direction on the front side of the instrument panel 16, and the front end of the front windshield 18 is supported by the cowl 20. The center defroster duct 30 is bent with a convex shape towards the rear at a bent portion 30B located behind the cowl 20, and branches into a front opening 30D and a rear opening 30E in the vehicle longitudinal direction at a branching portion 30C located above the bent portion 30B. The front opening 30D and the rear opening 30E of the center defroster duct 30 open toward the front windshield 18 at the front end of the instrument panel 16.

[0026] As described above, since the front opening 30D and rear opening 30E of the center defroster duct 30 are located at the front end of the instrument panel 16, the front opening 30D and rear opening 30E are less likely to directly enter the occupant's field of vision (see line of sight L1 shown in Figure 4). This improves the appearance. Moreover, because the position where the front opening 30D and rear opening 30E are reflected in the front windshield 18 is lower, the front opening 30D and rear opening 30E reflected in the front windshield 18 are less likely to enter the occupant's forward field of vision (see line of sight L2 shown in Figure 4). This reduces the occupant's discomfort.

[0027] Furthermore, in this embodiment, pressure loss occurs at the bend 30B of the center defroster duct 30, but because the center defroster duct 30 is branched as described above, the pressure loss can be reduced compared to a center defroster duct with a single opening. As a result, it becomes easier to secure sufficient airflow volume and velocity of the airflow W1 and W2 blown out from the front opening 30D and the rear opening 30E. Moreover, the airflow W1 blown out from the front opening 30D, whose velocity is increased by the Venturi effect, attracts the airflow W2 blown out from the rear opening 30E, thereby suppressing the diffusion of the airflow W1 and W2. From the above, the window clearing performance that removes fogging from the front windshield 18 is improved.

[0028] Furthermore, in this embodiment, the front inner wall surface of the rear opening 30E has a curved surface 32 that curves convexly toward the rear and downward. As a result, the air conditioning air (airflow) flowing into the rear opening can be controlled by the Coanda effect, which causes the airflow to flow along the curved surface 32, and the airflow blown out from the rear opening 30E can be effectively decelerated. As a result, the diffusion suppression effect of the blown air W1 and W2 described above can be improved.

[0029] The above effects will be further explained using comparative examples shown in Figures 5 to 7. In the first comparative example shown in Figure 5, there is no bend 30B at the top of the center defroster duct 30, and the opening 30F provided at the upper end of the center defroster duct 30 opens in the middle of the front-to-rear direction of the upper surface of the instrument panel 16. This opening 30F is in the occupant's direct field of vision (see line of sight L1 shown in Figure 5), which is unsightly. In addition, the opening 30F reflected in the front windshield 18 is in the occupant's forward field of vision (see line of sight L2 shown in Figure 5), which can be bothersome to the occupant, but this can be avoided in this embodiment (see Figure 4).

[0030] Furthermore, as shown in the second comparative example in Figure 6, when the opening 30G is located at the front end of the instrument panel 16 in a center defroster duct 30 with one opening 30G, the pressure loss at the bend 30B increases, reducing the airflow volume and velocity of the air blown out from the opening 30G. In this embodiment, compared to the second comparative example described above, the pressure loss can be reduced by, for example, 40% or more, so that the airflow volume and velocity of the blown air W1 and W2 can be sufficiently secured.

[0031] Furthermore, as shown in the third comparative example in Figure 7, in a center defroster duct 30 with one opening 30G, if the opening 30G located at the front end of the instrument panel 16 is enlarged, the pressure loss is reduced, but the airflow W4 blown out from the opening 30G is diffused. In this embodiment, however, as shown in Figure 3, the diffusion of the airflow W1 and W2 can be suppressed.

[0032] Although the present invention has been described above with reference to embodiments, the present invention can be implemented with various modifications without departing from its spirit. Furthermore, it goes without saying that the scope of the present invention is not limited to the above embodiments. [Explanation of Symbols]

[0033] 10 Defroster Structure 12 vehicles 16 Instrument Panel 18 Front windshield 20 Cowl (vehicle frame component) 30 Center defroster duct 30B Bending section 30C branch section 30D Front opening 30E rear opening 32 Curved surface

Claims

1. The vehicle's instrument panel and, A cowl extending in the vehicle width direction on the front side of the instrument panel, A front windshield whose front end is supported by the aforementioned cowl, The cowl outer panel of the cowl has a curved portion located at the rear of the vehicle that bends in a convex shape toward the rear of the vehicle, and at a branching portion located above the curved portion that branches in the front-rear direction of the vehicle into a front opening and a rear opening, and the front opening and the rear opening open toward the front windshield at the front end of the instrument panel to form a defroster duct, Equipped with, The upper and lower intermediate portion of the defroster duct is a rearward-sloping portion that inclines towards the rear of the vehicle as it moves towards the upper side of the vehicle, and the bent portion is provided on the upper part of the defroster duct on the upper side of the rearward-sloping portion, and the bent portion is a defroster structure that is bent in a substantially U-shape that opens towards the front of the vehicle when viewed from the side of the vehicle.

2. The defroster structure according to claim 1, wherein the inner wall surface on the front side of the rear opening has a curved surface that is convex toward the rear and downward side of the vehicle.

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