Grille shutter device

Abstract

To provide a grille shutter device which can inhibit deterioration of aerodynamic performance.SOLUTION: A grille shutter device includes: a frame body having an inlet into which air flows; and airfoil-shaped flaps 30 each having a rotary shaft supported rotatably relative to the frame body and configured to open or close the inlet by rotating in forward and reverse directions around respective rotary shafts. Each flap 30 includes a symmetrical airfoil portion 45 forming a portion between an upstream edge 41 and a second portion 44 in the flap 30. The symmetrical airfoil portion 45 is shaped to be symmetrical with respect to a chord line C connecting the upstream edge 41 with a downstream edge 42. A thickness of the symmetrical airfoil portion 45 gradually increases from the upstream edge 41 to a first portion 43 and gradually decreases from the first portion 43 toward the second portion 44.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a grill shutter device. [Background technology]

[0002] Patent Document 1 discloses a grille shutter device that opens and closes an opening provided in the front of a vehicle. The grille shutter device has multiple fins with a rotation shaft that extends in the vehicle width direction. The multiple fins rotate forward and backward around the rotation shaft to open and close the opening.

[0003] The fin has a forward protruding portion located forward of the rotation axis when the opening is open, and a rearward protruding portion located rearward of the rotation axis. The front end of the forward protruding portion is formed with a lower chamfered portion and an upper chamfered portion, each of which has an arc-shaped cross section. The radius of curvature of the upper chamfered portion is larger than the radius of curvature of the lower chamfered portion. This allows air flowing from the front of the fin toward the fin to more easily flow toward the upper side of the fin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-104449 Summary of the Invention [Problem to be solved by the invention]

[0005] In the grille shutter device described in Patent Document 1, air flowing toward the fins tends to flow toward the upper side of the fins, creating a difference in air pressure between the upper and lower sides of the fins. As a result, lift is generated in the fins, which may reduce the aerodynamic performance of the grille shutter device. This problem occurs even when the rotation axis of the fins extends in the vertical direction. [Means for solving the problem]

[0006] Various aspects of the grille shutter device for solving the above problems will be described below. [Aspect 1] A grill shutter device for opening and closing an opening provided in the front of a vehicle, comprising: a frame body having an inlet through which air flows; and a plurality of wing-shaped flaps having a rotary shaft rotatably supported on the frame body and rotating in forward and reverse directions around the rotary shaft to open and close the inlet, wherein the upstream edge and downstream edge of the flaps in the air flow direction when the flaps are in an open position that opens the inlet are referred to as an upstream edge and a downstream edge, respectively; a portion between the upstream edge and the downstream edge is referred to as a first portion; When a portion between the first portion and the downstream edge is defined as a second portion, the flap includes a symmetrical wing portion that constitutes the portion of the flap between the upstream edge and the second portion, the symmetrical wing portion has a symmetrical shape with respect to a chord line connecting the upstream edge and the downstream edge, and the thickness of the symmetrical wing portion in a direction perpendicular to both the direction in which the chord line extends and the direction in which the rotation axis extends gradually increases from the upstream edge toward the first portion and gradually decreases from the first portion toward the second portion. A grill shutter device.

[0007] According to the above configuration, the flap includes a symmetrical wing portion that forms a portion between the upstream edge and the second portion. The thickness of the symmetrical wing portion gradually increases from the upstream edge toward the first portion, and gradually decreases from the first portion toward the second portion. This reduces the pressure difference between the air flowing on both sides of the flap in the thickness direction when the flap is in the open position. It also reduces an increase in air resistance due to the shape of the flap. This therefore reduces a decrease in the aerodynamic performance of the grille shutter device.

[0008] [Aspect 2] A grill shutter device according to [Aspect 1], wherein the downstream edge has a planar downstream end face that is perpendicular to the chord line. It is known that for symmetrical wings, which are symmetrical with respect to the chord line, there is little difference in aerodynamic performance between a configuration with a tapered portion at the downstream end and a configuration with a truncated end face at the downstream end that is a flat end face perpendicular to the chord line.

[0009] According to the above configuration, the downstream edge of the flap is formed with a flat downstream end surface that is perpendicular to the chord line, which reduces the pressure difference between the air flowing on both sides of the flap in the thickness direction when the flap is in the open position, while suppressing an increase in the size of the flap in the chord line direction.

[0010] [Aspect 3] The flap includes an asymmetric wing portion that is continuous with the downstream side of the symmetric wing portion and has an asymmetric shape with respect to the chord line, and the asymmetric wing portion has a contact surface that contacts the outer surface of the symmetric wing portion of another flap when the flap is in a closed position that blocks the inlet.A grill shutter device described in [Aspect 1] or [Aspect 2].

[0011] According to the above configuration, the contact surface of the asymmetric wing portion contacts the outer surface of the symmetric wing portion of the other flap, thereby reducing the gap between the contacting flaps. This makes it possible to suppress an increase in air resistance caused by air flowing into the gap between the flaps in the closed position. Therefore, it is possible to suppress a decrease in the aerodynamic performance of the grille shutter device when the flaps are in the closed position.

[0012] [Aspect 4] A grill shutter device as described in [Aspect 3], in which a pair of curved surfaces that are convex in a direction away from the chord line are formed on both sides of the thickness direction of the symmetrical wing portion, and the contact surface is curved along the curved surface of the other flap.

[0013] According to the above configuration, the contact surface of the flap is curved along the curved surface of the other flap. This makes it possible to further reduce the gap between the contacting flaps. This further reduces the deterioration of the aerodynamic performance of the grille shutter device when the flaps are in the closed position. [Effects of the Invention]

[0014] According to the present invention, it is possible to suppress a decrease in the aerodynamic performance of the grille shutter device. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a front view showing a vehicle equipped with a grille shutter device according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view showing the grill shutter device of FIG. [Figure 3] FIG. 3 is a plan view showing the grille shutter device when the flap is in the open position. [Figure 4] FIG. 4 is a plan view showing the grille shutter device when the flap is in the closed position. [Figure 5] 5 is a cross-sectional view showing the main body of the flap of FIG. 2. FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which the main body portions of the flaps are in contact with each other when they are in the closed position. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, one embodiment of the grille shutter device 10 will be described with reference to Figures 1 to 6. In this specification, "symmetric" is a concept that includes not only strict symmetry but also approximate symmetry within the scope of the effects of this embodiment. Furthermore, in this specification, "orthogonal" is a concept that includes not only strict orthogonal but also approximate orthogonal within the scope of the effects of this embodiment.

[0017] Hereinafter, the front and rear in the longitudinal direction of the vehicle 100 shown in Fig. 1 will be described as "front" and "rear", respectively. Furthermore, the right and left in the vehicle width direction when the vehicle 100 is moving forward will be described as "right" and "left", respectively. Furthermore, the top and bottom in the vertical direction of the vehicle 100 will be described as "upper" and "lower", respectively.

[0018] (Grille shutter device 10) As shown in Fig. 1, the grille shutter device 10 is attached to an opening 102 provided in the front part of a body 101 of a vehicle 100. The grille shutter device 10 opens and closes the opening 102 to allow or block the inflow of air into the inside of the body 101 through the opening 102. Behind the opening 102 inside the body 101, for example, a radiator (not shown) is arranged.

[0019] The front of the vehicle 100 has a design surface 100a that curves from the center in the vehicle width direction toward the outside, becoming more rearward. The grille shutter device 10 forms part of the design surface 100a. The grille shutter device 10 curves and extends along the design surface 100a from the center in the vehicle width direction toward the outside, becoming more rearward.

[0020] The grille shutter device 10 has a cover portion 11 and two shutter portions 12 located on both sides of the cover portion 11 in the vehicle width direction. A device such as a millimeter wave radar (not shown) is attached to the rear surface of the cover portion 11. The two shutter portions 12 have shapes symmetrical in the vehicle width direction.

[0021] Hereinafter, the configuration of the left shutter section 12 of the two shutter sections 12 will be described, and a description of the configuration of the right shutter section 12 will be omitted. 2, the shutter section 12 includes a frame body 20, a plurality of flaps 30, an upper retainer 50, a lower retainer 51, a link 60, and an actuator 70. The frame body 20, each of the flaps 30, the upper retainer 50, the lower retainer 51, and the link 60 are formed from a resin material.

[0022] The frame body 20 is attached to an opening 102 (see FIG. 1) of a body 101. A plurality of flaps 30 are rotatably supported by the frame body 20. An upper retainer 50 and a lower retainer 51 prevent the plurality of flaps 30 supported by the frame body 20 from falling off. A link 60 connects the plurality of flaps 30 to one another, thereby interlocking the rotation of the plurality of flaps 30 relative to the frame body 20. An actuator 70 rotates the flaps 30.

[0023] Each component of the shutter section 12 will be described in detail below. (Frame 20) The frame 20 has an inlet 21 through which air flows in. The inlet 21 penetrates the frame 20 in the front-rear direction. The inlet 21 has a generally rectangular shape that is long in the vehicle width direction.

[0024] The frame body 20 has an upper frame portion 22 that forms the upper edge of the inlet 21, a lower frame portion 23 that forms the lower edge of the inlet 21, and a pair of vertical frame portions 24 that form both side edges of the inlet 21. The pair of vertical frame portions 24 connect the ends of the upper frame portion 22 and the lower frame portion 23 to each other.

[0025] The front surface of the portion of the frame body 20 surrounding the inlet 21 curves and extends so that the further it goes from the cover portion 11 to the outer portion in the vehicle width direction, the more rearward it is positioned. The upper frame 22 has a plurality of upper support portions 25 that rotatably support upper rotation shafts 33 of the flaps 30, which will be described later. The plurality of upper support portions 25 are arranged side by side at intervals from one another in the longitudinal direction of the inlet 21. Each upper support portion 25 protrudes rearward from the rear surface of the upper frame 22. Each upper support portion 25 opens rearward and has a recess that rotatably houses the upper rotation shaft 33. The upper rotation shaft 33 is housed in the recess of each upper support portion 25 through the rear opening.

[0026] The lower frame 23 has a plurality of lower support portions 26 that rotatably support a lower rotation shaft 34 of the flap 30, which will be described later. The plurality of lower support portions 26 are arranged in a line at intervals from one another in the longitudinal direction of the inlet 21. The plurality of lower support portions 26 are provided at positions corresponding to the plurality of upper support portions 25. Each lower support portion 26 protrudes rearward from the rear surface of the lower frame 23. Each lower support portion 26 opens rearward and has a recess that rotatably accommodates the lower rotation shaft 34. The lower rotation shaft 34 is accommodated in the recess of each lower support portion 26 through the rear opening.

[0027] A plurality of upper cutouts 22a are formed at intervals in the longitudinal direction of the inlet 21 in a portion of the rear surface of the upper frame portion 22 that forms the upper edge of the inlet 21. The plurality of upper cutouts 22a are formed so as to be positioned as far rearward as the upper cutouts 22a positioned on the outer side in the vehicle width direction. Each upper cutout 22a has a shape that follows the front surface of a symmetrical wing portion 45 of the flap 30 that is positioned in a closed position, which will be described later.

[0028] A plurality of lower cutouts 23a are formed at intervals in the longitudinal direction of the inlet 21 in a portion of the rear surface of the lower frame portion 23 that forms the lower edge of the inlet 21. The plurality of lower cutouts 23a are formed so as to be positioned as far rearward as the lower cutouts 23a positioned on the outer sides in the vehicle width direction. The plurality of lower cutouts 23a are provided at positions corresponding to the plurality of upper cutouts 22a. Each lower cutout 23a has a shape that follows the front surface of a symmetrical wing portion 45 of the flap 30 when it is in a closed position, which will be described later.

[0029] (Flap 30) The multiple flaps 30 are arranged side by side in the longitudinal direction of the inlet 21. The multiple flaps 30 include one driving flap 30A and multiple driven flaps 30B. The shutter section 12 has, for example, seven driven flaps 30B. The driving flap 30A is arranged, for example, between three driven flaps 30B that are parallel to one another and four driven flaps 30B that are parallel to one another.

[0030] The flap 30 has a main body 31, an upper rotation shaft 33, a lower rotation shaft 34, and a support shaft 35. The main body 31, the upper rotation shaft 33, the lower rotation shaft 34, and the support shaft 35 are formed continuously and integrally without any breaks. The main body 31 of the multiple flaps 30 have the same shape. The upper rotation shaft 33 of the driving flap 30A and the upper rotation shaft 33 of the driven flap 30B have different shapes. The upper rotation shaft 33 and the lower rotation shaft 34 are examples of "rotation shafts."

[0031] The main body 31 is shaped like a plate having long sides extending in the vertical direction and short sides extending in a direction perpendicular to the long sides. The cross-sectional shape of the main body 31 perpendicular to the vertical direction is wing-shaped. The cross-sectional shape and size of the main body 31 perpendicular to the vertical direction are the same throughout the entire vertical direction.

[0032] The upper end of the main body 31 is provided with a protruding piece 32 that protrudes to one side in the thickness direction of the main body 31. The upper rotation shaft 33 protrudes upward from the upper end of the main body 31. The upper rotation shaft 33 is located at one end of the main body 31 in the short side direction. The lower rotation shaft 34 protrudes downward from the lower end of the main body 31. The lower rotation shaft 34 is located at one end of the main body 31 in the short side direction. The upper rotation shaft 33 and the lower rotation shaft 34 are located on the same axis extending in the vertical direction. The upper rotation shaft 33 and the lower rotation shaft 34 are rotatably supported by the upper support part 25 and the lower support part 26, respectively.

[0033] The multiple flaps 30 are arranged side by side on an imaginary axis V that extends linearly so that the more outwardly they are positioned rearward in the vehicle width direction. More specifically, the multiple upper rotation shafts 33 are arranged side by side on the imaginary axis V, and the multiple lower rotation shafts 34 are arranged side by side on the imaginary axis V. The multiple flaps 30 are arranged at equal intervals along the imaginary axis V.

[0034] A gear portion 33a having a plurality of teeth is formed at the tip of the upper rotary shaft 33 of the drive flap 30A. The support shaft 35 protrudes upward from the tip of the protruding piece 32 of the main body 31. The support shaft 35 is located rearward of the upper rotation shaft 33.

[0035] 3 and 4, the flap 30 opens and closes the inlet 21 by rotating about an upper rotation shaft 33 and a lower rotation shaft 34 between an open position that opens the inlet 21 and a closed position that closes the inlet 21. The upper retainer 50 and the lower retainer 51 are not shown in FIGS.

[0036] As shown in FIG. 3, when the flap 30 is in the open position, the direction of the short side of the main body 31 coincides with the front-rear direction of the vehicle 100. As shown in Figure 4, when the flap 30 is in the closed position, the short side direction of the main body 31 is inclined relative to the vehicle width direction so that it is positioned further rearward from one end where the upper rotating shaft 33 and the lower rotating shaft 34 are provided to the other end.

[0037] Next, the shape of the main body 31 of the flap 30 will be described in detail with reference to Figures 5 and 6. In Figures 5 and 6, hatching of the main body 31 is omitted for ease of understanding.

[0038] Hereinafter, the upstream edge and downstream edge of the main body 31 in the airflow direction when the flap 30 is in the open position will be referred to as the upstream edge 41 and downstream edge 42, respectively. A virtual line connecting the upstream edge 41 and the downstream edge 42 will be referred to as the chord line C. The thickness direction of the flap 30 will be a direction perpendicular to both the direction in which the chord line C extends and the up-down direction in which the upper rotation shaft 33 and the lower rotation shaft 34 extend. A portion between the upstream edge 41 and the downstream edge 42 will be referred to as the first portion 43. A portion between the first portion 43 and the downstream edge 42 will be referred to as the second portion 44. The first portion 43 is located upstream of the midpoint of the chord line C. The second portion 44 is located downstream of the midpoint on the chord line C between the first portion 43 and the downstream edge 42.

[0039] The direction in which the chord line C extends coincides with the direction of the short side of the main body 31. Therefore, when the flap 30 is in the open position, the upstream edge 41 becomes the front edge of the main body 31, and the downstream edge 42 becomes the rear edge of the main body 31.

[0040] 5, the main body 31 has a symmetrical wing portion 45 that is symmetrical with respect to the chord line C, and an asymmetrical wing portion 46 that is asymmetrical with respect to the chord line C. The symmetrical wing portion 45 constitutes the portion between the upstream edge 41 and the second portion 44 of the flap 30. The asymmetrical wing portion 46 constitutes the portion between the second portion 44 and the downstream edge 42 of the flap 30. Therefore, the asymmetrical wing portion 46 is formed continuously on the downstream side of the symmetrical wing portion 45. The second portion 44 is the boundary between the symmetrical wing portion 45 and the asymmetrical wing portion 46.

[0041] In order to suppress a decrease in the aerodynamic performance of the flap 30, it is preferable that the proportion of the asymmetric wing portion 46 in the main body portion 31 is small. In this embodiment, the proportion of the asymmetric wing portion 46 in the main body portion 31 is set to about 5% or less.

[0042] The thickness of the symmetrical wing portion 45 gradually increases from the upstream edge 41 toward the first portion 43, and gradually decreases from the first portion 43 toward the second portion 44. That is, the first portion 43 is the portion with the greatest thickness in the symmetrical wing portion 45. The portion of the flap 30 upstream of the first portion 43 has a tapered shape with an arc-shaped tip.

[0043] A pair of curved surfaces 47 that convex in a direction away from the chord line C are formed on both sides of the symmetrical wing portion 45 in the thickness direction. The pair of curved surfaces 47 are streamlined. The pair of curved surfaces 47 extend so as to move away from each other in the thickness direction from the upstream edge 41 toward the first portion 43, and also extend so as to move closer to each other in the thickness direction from the first portion 43 toward the second portion 44. Each curved surface 47 is farthest from the chord line C at the first portion 43. The portion of each curved surface 47 downstream of the first portion 43 is more gently curved than the portion upstream of the first portion 43.

[0044] The thickness of the asymmetric airfoil portion 46 gradually decreases from the second portion 44 toward the downstream edge 42 . As shown in FIG. 6 , a contact surface 48 is formed on one side in the thickness direction of the asymmetric wing portion 46. The contact surface 48 comes into contact with the outer surface of the symmetric wing portion 45 of the other flap 30 when the flap 30 is in the closed position. The contact surface 48 is formed on the outer surface of the asymmetric wing portion 46 on the front side in the movement direction when the flap 30 rotates and moves from the open position to the closed position. The contact surface 48 is curved along the curved surface 47 of the other flap 30 so as to approach the chord line C as it moves downstream. The contact surface 48 comes into surface contact with the curved surface 47 of the other flap 30 from the rear. The contact surface 48 is formed over the entire main body portion 31 in the up-down direction. The curved surface 47, the contact surface 48, and the downstream end surface 49 are continuous.

[0045] As shown in Figure 5, the outer surface of the asymmetric wing portion 46 opposite the contact surface 48 in the thickness direction is curved with the same curvature as the curved surface 47 of the symmetric wing portion 45 downstream of the first portion 43.

[0046] The downstream edge 42 is formed with a flat downstream end surface 49 that is perpendicular to the chord line C. The cross-sectional shape of the main body 31 can also be said to be a so-called cam tail shape in which the downstream end of a symmetrical airfoil is cut off. The cross-sectional shape of the main body 31 in this embodiment is a shape in which the downstream end of a NACA0006 airfoil, which is a symmetrical airfoil, is cut off and a contact surface 48 is formed. Therefore, the cross-sectional shape of the symmetrical airfoil portion 45 has the same cross-sectional shape as a part of the NACA0006 airfoil.

[0047] As shown in FIGS. 4 and 6 , the multiple flaps 30 in the closed position are arranged side by side so that the front surfaces of the multiple flaps 30 exposed from the inlet 21 are aligned along the front surfaces of the upper frame portion 22 and the lower frame portion 23. When the flaps 30 are in the closed position, one end of the main body portion 31, on which the upper rotation shaft 33 and the lower rotation shaft 34 are provided, in the short side direction is overlapped from behind by the other end of the main body portion 31 opposite to the one end of the other main body portion 31. More specifically, the contact surface 48 of the main body portion 31 contacts the curved surface 47 of the other main body portion 31 from behind. At this time, one end of the main body portion 31 of the flap 30 positioned innermost in the vehicle width direction overlaps from behind the vertical frame portion 24 positioned innermost in the vehicle width direction. Furthermore, the other end of the main body portion 31 of the flap 30 positioned outermost in the vehicle width direction overlaps from behind the vertical frame portion 24 positioned outermost in the vehicle width direction.

[0048] The front surface of the main body portion 31 of each flap 30 in the closed position is in contact with the rear surfaces of the upper frame portion 22 and the lower frame portion 23. More specifically, the front surface of the symmetrical wing portion 45 of each flap 30 in the closed position is in contact with the inner surfaces of the upper cutout 22a and the lower cutout 23a. At this time, the asymmetrical wing portion 46 of each flap 30 is not in contact with the inner surfaces of the upper cutout 22a and the lower cutout 23a.

[0049] (Upper retainer 50 and lower retainer 51) As shown in FIG. 2, the upper retainer 50 and the lower retainer 51 are shaped like an elongated member extending in the direction of the long side of the inlet 21 .

[0050] The upper retainer 50 is attached to the upper frame 22 so as to cover from the rear the recesses of all of the upper support parts 25. This prevents the upper rotating shaft 33 housed in the recesses of the upper support parts 25 from falling out.

[0051] The lower retainer 51 is attached to the lower frame portion 23 so as to cover from the rear the recesses of all of the lower support portions 26. This prevents the lower rotation shaft 34 housed in the recesses of the lower support portions 26 from falling out.

[0052] (Link 60) The link 60 has a long plate shape extending in the direction of the long side of the inlet 21. The link 60 has a plurality of support holes 61 that rotatably support the support shafts 35 of the flaps 30. The plurality of support holes 61 are provided at intervals from one another in the longitudinal direction of the link 60. The plurality of support holes 61 are provided side by side along the imaginary axis V described above.

[0053] The link 60 transmits the power acting on the driving flap 30A to each of the driven flaps 30B via the actuator 70. As a result, each of the driven flaps 30B rotates in conjunction with the rotational movement of the driving flap 30A.

[0054] (actuator 70) The actuator 70 is, for example, a motor whose output shaft is rotatable in both forward and reverse directions.

[0055] The actuator 70 is attached to, for example, the upper retainer 50. The output shaft of the actuator 70 is connected to the gear portion 33a of the driving flap 30A. The power of the actuator 70 is transmitted to the driving flap 30A via the gear portion 33a, causing the driving flap 30A to rotate in the forward and reverse directions.

[0056] <Operation of this embodiment> The thickness of the symmetrical wing portion 45 of the flap 30 gradually increases from the upstream edge 41 toward the first portion 43, and gradually decreases from the first portion 43 toward the second portion 44. This reduces the pressure difference between the air flowing on both sides of the flap 30 in the thickness direction when the flap 30 is in the open position. It also reduces an increase in air resistance due to the shape of the flap 30.

[0057] <Effects of this embodiment> (1) The flap 30 includes a symmetrical wing portion 45 that constitutes a portion of the flap 30 between the upstream edge 41 and the second portion 44. The thickness of the symmetrical wing portion 45 gradually increases from the upstream edge 41 toward the first portion 43, and gradually decreases from the first portion 43 toward the second portion 44.

[0058] According to the above configuration, the above-mentioned effects are achieved, and therefore the deterioration of the aerodynamic performance of the grille shutter device 10 can be suppressed. Furthermore, since an increase in the air resistance of the flap 30 is suppressed, when the flap 30 is in the open position, air is more likely to flow into the inside of the body 101 through the opening 102. Therefore, the cooling efficiency of devices mounted on the vehicle 100, such as a radiator, can be improved.

[0059] (2) The downstream edge 42 has a flat downstream end surface 49 that is perpendicular to the chord line C. It is known that in a symmetrical wing with respect to the chord line C, there is little difference in aerodynamic performance between a configuration with a tapered portion at the downstream end and a configuration with a truncated end face at the tip of the portion that is a flat end face perpendicular to the chord line C.

[0060] According to the above configuration, the downstream edge 42 of the flap 30 is formed with a planar downstream end surface 49 that is perpendicular to the chord line C. This makes it possible to reduce the pressure difference between the air flowing on both sides in the thickness direction of the flap 30 when it is in the open position, while also suppressing an increase in the size of the flap 30 in the direction in which the chord line C extends.

[0061] Furthermore, if the flap 30 is made of resin and has a portion that tapers toward the downstream edge 42, the thickness of the tapered portion will be small, which may make it difficult to mold the flap 30.

[0062] In this regard, according to the above-described configuration, the downstream end surface 49 is formed on the downstream edge 42 of the flap 30, which prevents the thickness of the flap 30 from becoming excessively thin. Therefore, the flap 30 made of resin can be easily molded.

[0063] (3) The asymmetric wing portion 46 has a contact surface 48 that comes into contact with the curved surface 47 of the symmetric wing portion 45 of another flap 30 when the flap 30 is in the closed position that blocks the inlet 21 .

[0064] According to the above configuration, the contact surface 48 of the asymmetric wing portion 46 comes into contact with the curved surface 47 of the symmetric wing portion 45 of another flap 30, thereby reducing the gap between the flaps 30 that come into contact with each other. This makes it possible to suppress an increase in air resistance caused by air flowing into the gap between the flaps 30 that are in the closed position. Therefore, it is possible to suppress a decrease in the aerodynamic performance of the grille shutter device 10 when the flaps 30 are in the closed position.

[0065] (4) The contact surface 48 is curved along the curved surface 47 of the other flap 30 . According to the above configuration, the contact surface 48 of one flap 30 is curved along the curved surface 47 of another flap 30. This makes it possible to further reduce the gap between the flaps 30 that come into contact with each other. This further reduces the deterioration of the aerodynamic performance of the grille shutter device 10 when the flap 30 is in the closed position.

[0066] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0067] The contact surface 48 does not have to be curved. The contact surface 48 may be a flat inclined surface inclined with respect to the chord line C. In this case, the outer surfaces on both sides in the thickness direction of the symmetrical wing portion 45 may be curved surfaces 47, or may be outer surfaces shaped to follow the contact surface 48.

[0068] The asymmetric wing portion 46 may not have a contact surface 48. In this case, the symmetric wing portion 45 may constitute the portion between the upstream edge 41 and the downstream edge 42 on which the downstream end surface 49 is formed. In other words, the entire main body 31 may be the symmetric wing portion 45.

[0069] The flaps 30 in the closed position do not need to be in contact with each other. The downstream end surface 49 may be a flat surface that is slightly inclined with respect to the thickness direction of the flap 30 .

[0070] The downstream edge 42 of the flap 30 may not have a downstream end surface 49. In this case, the flap 30 may have a tapered portion at the downstream end. In this case, the contact surface 48 may be formed upstream of the tip of the tapered portion of the flap 30.

[0071] The flap 30 may be made of a metal material. The upper rotation shaft 33 and the lower rotation shaft 34 may be provided between one end and the other end of the main body 31 in the short side direction.

[0072] The flap 30 may have a rotation shaft extending in the vehicle width direction instead of the upper rotation shaft 33 and the lower rotation shaft 34. This rotation shaft is preferably rotatably supported by the pair of vertical frame portions 24, for example.

[0073] The grille shutter device 10 does not have to constitute the design surface 100a of the vehicle 100. As long as the grille shutter device 10 opens and closes the opening 102, it may be disposed behind the design surface 100a within the opening 102. [Explanation of symbols]

[0074] C…Chord line V: Virtual axis 10...Grille shutter device 11...Cover part 12...Shutter section 20...Frame 21...Inlet 22...Top frame part 22a...Top notch 23…Bottom frame part 23a...lower notch 24...Vertical frame section 25...Top support part 26…Lower support part 30...Flap 30A...Drive flap 30B...Following flap 31...Main body 32...Protruding piece 33...Upper rotating shaft 33a...Gear section 34...Lower rotating shaft 35...Support shaft 41...Upstream edge 42...Downstream edge 43…Part 1 44…Second part 45...Symmetrical wing section 46...Asymmetric wing section 47...Curved surface 48…Contact surface 49…Downstream end face 50...Upper retainer 51...Lower retainer 60...Links 61...Support hole 70...Actuator 100...Vehicle 100a...Design surface 101...Body 102...Opening

Claims

1. A grille shutter device that opens and closes an opening provided in the front of a vehicle, a frame having an inlet through which air flows in; a plurality of wing-shaped flaps that have a rotation shaft rotatably supported on the frame body and rotate in forward and reverse directions around the rotation shaft to open and close the inlet, When the upstream edge and downstream edge of the flap in the air flow direction when the flap is positioned at an open position that opens the inlet are defined as an upstream edge and a downstream edge, respectively, a portion between the upstream edge and the downstream edge is defined as a first portion, and a portion between the first portion and the downstream edge is defined as a second portion, the flap includes a symmetrical airfoil portion that defines a portion of the flap between the upstream edge and the second portion; The symmetrical blade portion has a symmetrical shape with respect to a chord line connecting the upstream edge and the downstream edge, a thickness of the symmetrical blade portion in a direction perpendicular to both the chord line and the rotation axis gradually increases from the upstream edge toward the first portion, and gradually decreases from the first portion toward the second portion; Grill shutter device.

2. The downstream edge has a flat downstream end surface perpendicular to the chord line. The grill shutter device according to claim 1.

3. the flap includes an asymmetric wing portion that is continuous with the symmetric wing portion on the downstream side and has an asymmetric shape with respect to the chord line, The asymmetric wing portion has a contact surface formed thereon that contacts an outer surface of the symmetric wing portion of the other flap when the flap is positioned at a closed position that closes the inlet. The grill shutter device according to claim 1 or 2.

4. A pair of curved surfaces that are convex in a direction away from the chord line are formed on both sides of the symmetrical wing portion in the thickness direction, The contact surface is curved along the curved surface of the other flap. The grill shutter device according to claim 3.

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