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 for a vehicle. [Background technology]

[0002] In the automotive air conditioner disclosed in the following Patent Document 1, the defroster outlets of the center duct and side ducts of the defroster device are engaged with the duct 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 the "defroster opening") is blown onto the inner surface of the front wind panel supported by the cowl top panel. This removes the fogging caused by water droplets adhering to the inner surface of the front wind panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-183429 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned prior art, the defroster opening provided on the upper surface of the instrument panel is directly in the field of vision of the occupant, which not only makes it look bad, but also causes the occupant to feel annoyed because the defroster opening reflected in the front wind panel is in the occupant's field of vision. In order to solve this problem, the defroster opening may be disposed at the front end of the instrument panel. However, in order to ensure the occupant's field of vision, it is necessary to set the upper surface of the instrument panel low. In addition, a cowl, which is a vehicle frame member, is disposed near the front end of the instrument panel. In order to avoid interference between this cowl and the defroster duct, it is necessary to bend a part of the defroster duct largely in a convex shape toward the rear of the vehicle behind the cowl. As a result, a large pressure loss occurs in the defroster duct, and it is not possible to ensure a sufficient air volume and flow speed. If the defroster opening is widened to solve this problem, there is a problem that the air blown from the defroster opening is diffused.

[0005] The present invention aims to obtain a defroster structure that can reduce pressure loss and diffusion of blown air in a configuration in which a portion of a 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 a first embodiment comprises a vehicle instrument panel, a vehicle frame member extending in the vehicle width direction at the vehicle front side of the instrument panel, a front windshield whose front end is supported by the vehicle frame member, and a defroster duct that bends convexly toward the vehicle rear side at a bent portion located at the vehicle rear of the vehicle frame member and branches in the vehicle fore-and-aft direction into a front opening and a rear opening at a branching portion located above the bent portion, the front opening and the rear opening opening toward the front windshield side at the front end of the instrument panel.

[0007] In the first aspect, a vehicle frame member extends in the vehicle width direction on the vehicle front side of the vehicle instrument panel, and the front end of the front windshield is supported by the vehicle frame member. The defroster duct is bent in a convex manner toward the rear of the vehicle at a bending portion disposed at the rear of the vehicle of the vehicle frame member, and is branched in the vehicle front-rear direction into a front opening and a rear opening at a branching portion disposed on the vehicle upper side from the bending portion. The front opening and the rear opening of the defroster duct open toward the front windshield side at the front end of the instrument panel. Since the defroster duct is branched as described above, pressure loss can be reduced compared to a defroster duct with a single opening. Moreover, the wind blown from the front opening, whose flow speed is increased by the Venturi effect, attracts the wind blown from the rear opening, thereby suppressing the diffusion of the blown wind.

[0008] The defroster structure of the second aspect is the first aspect, wherein an inner wall surface on the vehicle front side of the rear opening has a curved surface that is curved in a convex manner toward the vehicle rear and toward the vehicle lower side.

[0009] In the second aspect, the Coanda effect, which causes the airflow flowing into the rear opening of the defroster duct to flow along the curved surface, can control the airflow and effectively slow down the airflow blown out from the rear opening, thereby improving the effect of suppressing the diffusion of the blown airflow. Effect of the Invention

[0010] As described above, in the defroster structure of the present invention, pressure loss and diffusion of blown air can be reduced in a configuration in which 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. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a side view showing a defroster structure according to an embodiment. [Diagram 2]FIG. 2 is a perspective view showing a defroster duct provided in the defroster structure according to the embodiment. [Diagram 3] FIG. 4 is a cross-sectional view showing a portion of a defroster duct. [Figure 4] 1 is a side view showing a relationship between a defroster structure according to an embodiment and a line of sight of an occupant. [Diagram 5] FIG. 2 is a side view showing the relationship between the defroster structure according to the first comparative example and the line of sight of an occupant. [Figure 6] FIG. 11 is a cross-sectional view showing a portion of a defroster duct according to a second comparative example. [Figure 7] FIG. 11 is a cross-sectional view showing a portion of a defroster duct according to a third comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a defroster structure 10 according to one embodiment of the present invention will be described with reference to Figs. 1 to 7. Note that the arrows FR, UP, and RH appropriately shown in each figure indicate the front direction (traveling direction), the upward direction, and the rightward direction of the vehicle, respectively. Hereinafter, when the directions are simply used for the front-rear, left-right, top-bottom directions, they will refer to the front-rear, left-right, top-bottom directions of the vehicle.

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

[0014] The cowl 20 includes 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 a steel plate. Both ends in the vehicle width direction of the cowl outer panel 22 and the cowl inner panel 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 vehicle frame members that connect 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 disposed above the instrument panel 16, and supports the front end of the front windshield 18 from below. The cowl outer panel 22 has a support wall 22A extending along the front windshield 18, an inclined wall 22B extending obliquely rearward and downward from the rear end of the support wall 22A, and a joining wall 22C extending 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 an adhesive 24. The upper end of the cowl inner panel is joined to the joining wall 22C by means of welding or the like.

[0016] 1 to 3, the center defroster duct 30 constitutes a part of a duct structure that guides conditioned air blown from an air conditioning device (air conditioning unit) (not shown) disposed inside the instrument panel 16 into the vehicle interior 14. A pair of left and right side defroster ducts (not shown) are disposed on the left and right sides of the center defroster duct 30.

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

[0018] The vertical middle portion of the center defroster duct 30 is a rearward inclined portion 30A inclined toward the rear as it goes upward. A bent portion 30B is provided at the upper portion of the center defroster duct 30 above the rearward inclined portion 30A, which is bent to form a convex toward the rear. The bent portion 30B is bent in 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. The bent portion 30B is composed of a rearward extending portion 30B1 extending obliquely upward and rearward from the upper end portion of the rearward inclined portion 30A, an upper extending portion 30B2 extending upward from the rear end portion of the rearward extending portion 30B1, and a front extending portion 30B3 extending forward from the upper end portion of the upper extending portion 30B2.

[0019] At the upper end (tip) of the center defroster duct 30 extended forward from the above-mentioned front extension portion 30B3, a branch portion 30C is provided, which branches the upper end of the center defroster duct 30 into two in the vehicle front-rear direction. This branch portion 30C is disposed above the bent portion 30B. At this branch portion 30C, the upper end of the center defroster duct 30 branches into a front opening 30D and a rear opening 30E. The front opening 30D and the rear opening 30E are disposed side by side in the front-rear direction, and the front opening 30D is disposed forward of the rear opening 30E.

[0020] The front opening 30D and the rear opening 30E are long frame-shaped with the vehicle width direction as viewed in the vertical direction. The front opening 30D is set to have a larger width 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.

[0021] The conditioned air introduced into the center defroster duct 30 from the air conditioner passes through the rear inclined portion 30A and the bent portion 30B to reach the branching portion 30C, and is blown out from the front opening 30D and the rear opening 30E toward the front windshield 18. This removes fogging caused by water droplets adhering to the inner surface of the front windshield 18.

[0022] The inner wall surface on the front side of the rear opening 30E has a curved surface 32 that is curved to form a convex shape toward the rear and downward side. This curved surface 32 is arranged on the base side of the rear opening 30E, and is configured so that the conditioned air (air flow) flowing into the rear opening 30E hits the curved surface 32. The flow rate of the wind W1 blown from the front opening 30D (see FIG. 3) increases due to the Venturi effect, as the cross-sectional area of ​​the flow path becomes narrower at the front opening 30D. On the other hand, the wind W2 blown from the rear opening 30E (see FIG. 3) is decelerated due to the Coanda effect, in which the wind flowing into the rear opening 30E flows along the curved surface 32. As a result, the flow rate of the wind W1 blown from the front opening 30D is configured to be faster than the flow rate of the wind W2 blown from the rear opening 30E. Note that in FIG. 3, the conditioned air is dotted. The areas with darker dots in FIG. 3 are areas where the pressure of the conditioned air is high.

[0023] In the defroster structure 10 configured as described above, the upper surface of the instrument panel 16 is set low to ensure the forward visibility of the occupant. Also, in order to make it difficult for the front opening 30D and the rear opening 30E of the center defroster duct 30 to be in the field of vision of the occupant, the front opening 30D and the rear opening 30E are disposed at the front end of the instrument panel 16. And, in order to avoid interference between the center defroster duct 30 and the cowl 20, a bent portion 30B that is bent greatly to convex rearward is formed at the upper portion of the center defroster duct 30 behind the cowl outer panel 22.

[0024] (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 in front 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 rearwardly in a convex shape at a bent portion 30B disposed at the rear 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 portion 30C disposed above the bent portion 30B. The front opening 30D and 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 the rear opening 30E of the center defroster duct 30 are disposed at the front end of the instrument panel 16, the front opening 30D and the rear opening 30E are unlikely to directly enter the field of vision of the occupant (see line of sight L1 shown in FIG. 4). This improves the appearance. Moreover, since the positions at which the front opening 30D and the rear opening 30E are reflected in the front windshield 18 are lowered, the front opening 30D and the rear opening 30E reflected in the front windshield 18 are unlikely to enter the forward field of vision of the occupant (see line of sight L2 shown in FIG. 4). This makes it less likely for the occupant to feel annoyed.

[0027] In addition, in this embodiment, pressure loss occurs at the bent portion 30B of the center defroster duct 30, but since the center defroster duct 30 is branched as described above, the pressure loss can be reduced compared to a center defroster duct with one opening. As a result, it becomes easier to ensure sufficient air volume and flow speed of the winds W1 and W2 blown from the front opening 30D and the rear opening 30E. Moreover, the wind W1 blown from the front opening 30D, whose flow speed is increased by the Venturi effect, attracts the wind W2 blown from the rear opening 30E, thereby suppressing the diffusion of the winds W1 and W2. As a result, the wind clearing performance for removing fog from the front windshield 18 is improved.

[0028] Furthermore, in this embodiment, the inner wall surface on the front side of the rear opening 30E has a curved surface 32 that is curved to form a convex shape toward the rear and downward side. Therefore, the air flow can be controlled by the Coanda effect in which the conditioned air (wind flow) flowing into the rear opening flows along the curved surface 32, and the wind blown from the rear opening 30E can be effectively decelerated. As a result, the effect of suppressing the diffusion of the blown winds W1 and W2 described above can be improved.

[0029] The above-mentioned effects will be further explained using comparative examples shown in Figs. 5 to 7. In a first comparative example shown in Fig. 5, the bent portion 30B is not provided at the upper portion of the center defroster duct 30, and the opening 30F provided at the upper end of the center defroster duct 30 opens at the middle portion in the front-rear direction of the upper surface of the instrument panel 16. This opening 30F is in the direct field of vision of the occupant (see line of sight L1 shown in Fig. 5), which makes it look unattractive. In addition, the opening 30F reflected on the front windshield 18 is in the forward field of vision of the occupant (see line of sight L2 shown in Fig. 5), which makes the occupant feel annoyed, but this can be avoided in this embodiment (see Fig. 4).

[0030] 6, in a center defroster duct 30 having one opening 30G, if the opening 30G is located at the front end of the instrument panel 16, pressure loss increases at the bent portion 30B, reducing the volume and flow speed of the air blown from the opening 30G. In this regard, in the present embodiment, the pressure loss can be reduced by, for example, 40% or more compared to the second comparative example, and therefore the volume and flow speed of the air blown from the opening 30G can be sufficiently ensured.

[0031] 7, in a center defroster duct 30 having one opening 30G, if the opening 30G arranged at the front end of the instrument panel 16 is enlarged, the pressure loss is reduced, but the airflow W4 blown from the opening 30G is diffused. In this regard, in the present embodiment, the diffusion of the airflows W1 and W2 can be suppressed as shown in FIG.

[0032] Although the present invention has been described above by way of the embodiment, the present invention can be modified and embodied without departing from the spirit and scope of the present invention. Furthermore, the scope of the present invention is not limited to the above embodiment. [Explanation of symbols]

[0033] 10 Defroster structure 12 Vehicles 16 Instrument Panel 18 Front Windshield 20 Cowl (vehicle frame member) 30 Center defroster duct 30B Bending section 30C Branch 30D front opening 30E rear opening 32 Curved Surface

Claims

1. An instrument panel of a vehicle; a vehicle frame member extending in a vehicle width direction on a vehicle front side of the instrument panel; a front windshield having a front end supported by the vehicle frame member; a defroster duct that is bent in a convex manner toward the rear of the vehicle at a bent portion disposed at the rear of the vehicle of the vehicle frame member, and that branches in the front-to-rear direction of the vehicle into a front opening and a rear opening at a branching portion disposed on the vehicle upper side from the bent portion, the front opening and the rear opening opening opening toward the front windshield side at a front end portion of the instrument panel; Defroster structure equipped with

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

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