Air conditioner for vehicle

Abstract

A vehicular air conditioner including an air conditioner casing with a supply opening and a perforated panel with a plurality of vent holes, the perforated panel extending over the supply opening. The vent holes each extend through the perforated panel and each have an inlet opening exposed to an inside of the air conditioner casing, an outlet opening exposed to an interior of the vehicle compartment, and a nozzle length that extends from the inlet opening to the outlet opening and is within a range from 0.3 mm to 0.8 mm.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an air conditioner for a vehicle.

In general, air conditioners for vehicles include louvers moveable to define a direction of an air flow that is blown from a supply opening into a vehicle compartment. Japanese Patent Application First Publication No. 2003-276429 describes an air conditioner for a vehicle as shown in FIG. 6. As shown in FIG. 6, the air conditioner is disposed within instrument panel 21 of the vehicle which is located rearward of front window panel 22. Front window panel 22 is rearward inclined in a fore-and-aft direction of the vehicle. Air conditioning duct 24 is disposed inside instrument panel 21 and connected to a periphery of supply opening 23 that is formed on instrument panel 21. An air is blown out from air conditioning duct 24 through supply opening 23. Cover 27 that is made of punching metal and adapted for ventilation is disposed over supply opening 23. Eight louvers 25a-25h are arranged below cover 27 in substantially aligned relation to one another in the fore-and-aft direction of the vehicle. Each of louvers 25a-25h has an elongated shape in a width direction of the vehicle and moveable pivotally about pins 26 and downwardly. Respective pins are mounted to a front end portion of side edge portions of each of louvers 25a-25h which are opposed to each other in the width direction of the vehicle. Owing to the pivotal movement of louvers 25a-25h, a direction of the air blown through supply opening 23 is changeable. That is, an angle of the direction of the blown air with respect to the fore-and-aft direction of the vehicle is thus adjustable. Cover 27 extends over supply opening 23 to thereby enhance the appearance of instrument panel 21. Cover 27 may be made of gas permeable material or a gas permeable member such as a mesh.

SUMMARY OF THE INVENTION

However, cover 27 of the air conditioner of the above-described related art as conventionally proposed is adapted to simply hide the structural members within supply opening 23 which are located below cover 27. The conventional art does not consider a thickness of cover 27 and a volume ratio of vent holes formed in cover 27 to cover 27. Further, in the air conditioner of the related art, a direction of the air blown through cover 27 is defined by the pivotal position of louvers 25a-25h.

Therefore, in the related art, a width of the supply opening must be increased as large as possible for the purpose of directing the blown air over a wide angle range. In order to increase the width of the supply opening, an installation space for the air conditioner must be enlarged. However, the installation space cannot be enlarged due to limitation on design to the interior of a vehicle compartment.

Inventors of the present invention have studied and dedicated to realizing an air conditioner in which air blown through a cover can be directed over a wide angle range without enlarging the installation space of the air conditioner within the vehicle compartment. As a result, the inventors have found that the air blown through a cover can be directed over the wide angle range by a specific arrangement of vent holes that are formed in the cover and have a specific length.

It is an object of the present invention to provide an air conditioner for a vehicle which is capable of directing air blown through a cover over a wide angle range with arrangement of a perforated panel in a supply opening.

In one aspect of the present invention, there is provided an air conditioner for a vehicle, comprising:

• • an air conditioner casing with a supply opening through which an air flow is blown into a vehicle compartment; and
  • a perforated panel with a plurality of vent holes, the perforated panel extending over the supply opening of the air conditioner casing;
  • wherein the plurality of vent holes each extend through the perforated panel and each have an inlet opening that is exposed to an inside of the air conditioner casing, an outlet opening that is exposed to an interior of the vehicle compartment and a nozzle length that extends from the inlet opening to the outlet opening, the nozzle length being within a range from 0.3 mm to 0.8 mm.

In a further aspect of the present invention, there is provided an air conditioner for a vehicle, comprising:

• • an air conditioner casing with a supply opening through which an air flow is blown into a vehicle compartment;
  • a panel extending over the supply opening of the air conditioner casing; and
  • means for diverting a direction of the air flow that is blown out through the panel, the means extending through the panel over a length that ranges from 0.3 mm to 0.8 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross section of an essential part of an air conditioner for a vehicle, of a first embodiment according to the present invention.

FIG. 2 is a perspective view of a perforated panel of the air conditioner shown in FIG. 1.

FIG. 3 is an enlarged cross section of a part of the perforated panel of a second embodiment of the present invention, which shows a vent hole of the perforated panel.

FIG. 4 is an explanatory diagram that schematically shows a function of the vent hole of the perforated panel.

FIG. 5 is a perspective view of a perforated panel of the air conditioner of a third embodiment of the present invention.

FIG. 6 is a schematic cross section of an essential part of an air conditioner for a vehicle, of a related art.

DETAILED DESCRIPTION OF THE INVENTION

In the following, first to third embodiments of the present invention will be described in detail with reference to the accompanying drawings. Referring to FIGS. 1-2, an air conditioner for a vehicle, according to the first embodiment of the present invention is explained. As illustrated in FIG. 1, the air conditioner includes perforated panel 2, louver 3 and air conditioner casing 6 which are disposed inside instrument panel 8 of the vehicle. Air conditioner casing 6 is connected with a duct that supplies an air flow generated by a blower to air conditioner casing 6. Air conditioner casing 6 has supply opening 9 at an end portion thereof through which the air flow supplied via the duct is blown into a vehicle compartment. The end portion of air conditioner casing 6 is expanded toward an outside of air conditioner casing 6 so as to be formed into a generally sector-shape in section as shown in FIG. 1. Perforated panel 2 is mounted to the end portion of air conditioner casing 6 and extends over supply opening 9. Perforated panel 2 thus serves as a cover. Perforated panel 2 includes a body portion and a mount portion that surrounds the body portion and extends along an outer periphery of perforated panel 2. The mount portion is fixed to the generally sector-shaped end portion of air conditioner casing 6 by means of support member 7. A plurality of louvers 3, in this embodiment four louvers 3, are disposed below perforated panel 2 and arranged within air conditioner casing 6. Louvers 3 are substantially aligned with one another in a fore-and-aft direction of the vehicle. Louvers 3 are elongated in a width direction of the vehicle which extends perpendicular to the fore-and-aft direction thereof. Louvers 3 are operative to define a direction of the air flow that is blown onto perforated panel 2. Specifically, louvers 3 are pivotally moved by a link mechanism such that an inclination thereof is adjusted. The link mechanism is driven by rotationally operating an actuator dial.

As illustrated in FIG. 2, perforated panel 2 has a generally rectangular shape and is formed with a plurality of generally circular-shaped vent holes 12. Perforated panel 2 may be made of a suitable material, such as metal, fabric or synthetic resin. A punching metal and a mesh may be used as perforated panel 2. As shown in FIG. 1, vent holes 12 extend through perforated panel 2 to open to opposed inner and outer surfaces of perforated panel 2. Each of vent holes 12 thus has an inlet opening that is exposed to an inside space of air conditioner casing 6 and opposed to louvers 3, and an outlet opening that is exposed to an interior of the vehicle compartment. The inlet and outlet openings have generally circular shape.

As shown in FIG. 2, perforated panel 2 has a thickness as indicated at “t” and vent holes 12 have a length, hereinafter referred to as a nozzle length, that extends from the inlet opening to the outlet opening. The nozzle length of vent holes 12 is equivalent to the thickness “t” of perforated panel 2. In this embodiment, perforated panel 2 has thickness “t” of 0.3 mm to 0.8 mm, and therefore, the nozzle length of vent holes 12 is within a range from 0.3 mm to 0.8 mm. By selecting the nozzle length of vent holes 12 within this range, when the air flow is blown out through vent holes 12, the air flow can be blown out from vent holes 12 at an increased angle with respect to a direction of the nozzle length as compared to an angle of air flow which is formed between louvers 3 and the direction of the nozzle length. Namely, when the air flow is blown out from the outlet opening of vent holes 12 through the nozzle length, the direction of the air flow which is defined by louvers 3 can be largely diverted toward an outer surface of the outer peripheral portion of perforated panel 2 which is connected with the sector-shaped end portion of air conditioner casing 6.

If the nozzle length of vent holes 12 is smaller than 0.3 mm, the direction of the air flow which is defined by louvers 3 cannot be diverted and oriented toward the outer surface of the outer peripheral portion of perforated panel 2 when the air flow is blown out from the outlet opening of vent holes 12. If the nozzle length of vent holes 12 is larger than 0.8 mm, the direction of the air flow which is defined by louvers 3 will be diverted and oriented toward the direction of the nozzle length, thereby failing to largely change the air flow direction toward the outer peripheral portion of perforated panel 2 when the air flow is blown out from the outlet opening of vent holes 12. Vent holes 12 may be formed by a suitable method, for instance, stamping, though not limited to the specific method.

An opening area ratio of vent holes 12 to perforated panel 2 is within a range from 55% to 65%. That is, a ratio between a sum of opening areas of vent holes 12 to a surface area of perforated panel 2 is within a range from 55% to 65%. The ratio may be calculated on one of the opposed surfaces, for instance, the outer surface, of perforated panel 2. With this arrangement of vent holes 12 in perforated panel 2, the direction of the air flow blown out through vent holes 12 can be effectively varied over a wide angle range as explained later. If the ratio is larger than 65%, the direction of the air flow blown out through vent holes 12 cannot be varied over the wide angle range. If the ratio is smaller than 55%, resistance to ventilation in vent holes 12 will be increased to thereby cause deterioration in blow-out efficiency. Further, in such a case where the ratio is smaller than 55%, increased wind noise will occur to thereby deteriorate practicality of the air conditioner.

Referring to FIG. 3, the second embodiment of the present invention is explained, which differs from the first embodiment in provision of a plurality of nozzle portions on one side of the perforated panel. For the sake of simple illustration, FIG. 3 shows only one of nozzle portions 12a. Specifically, in this embodiment, a plurality of nozzle portions 12a extend from the inside surface of perforated panel 2 which is exposed to the inside space of air conditioner casing 6. Each of vent holes 12 extends from the inlet opening to the outlet opening through nozzle portions 12a and has the nozzle length as indicated at “h” in FIG. 3. The nozzle length “h” of vent holes 12 is within the range from 0.3 mm to 0.8 mm. Nozzle portions 12a of perforated panel 2 may be provided as burrs which may be formed upon stamping a metal plate into perforated panel 2. The thickness “t” of perforated panel 2 may be selectively set to a suitable value smaller than the nozzle length “h” of vent holes 12 so as to provide a rigidity necessary to serve as perforated panel 2.

Referring to FIG. 5, the third embodiment of the present invention is explained, which differs from the first embodiment in shape of the vent holes of the perforated panel. As illustrated in FIG. 5, perforated panel 2 is provided with a plurality of vent holes 14 in the form of generally rectangular-shaped slits. A ratio between a short side of the generally rectangular-shaped vent holes 14 and a long side thereof is within a range from 1:3 to 1:8. By setting the ratio within the range from 1:3 to 1:8, the air flow blown out from vent holes 14 can be oriented at a wide angle even when an inclination of louvers 3 is small. Further, the resistance to ventilation can be reduced to thereby suppress occurrence of wind noise and serve for enhancing operating efficiency of the air conditioner. The shape of vent holes 14 is not limited to those of the first to third embodiments and may be formed into various shapes such as a polygonal shape.

Referring to FIG. 4, a function of vent holes 12 of perforated panel 2 is explained. In FIG. 4, perforated panel 2 with nozzle portions 12a of the third embodiment is used. As shown in FIG. 1, when an air flow generated by the blower is transmitted to the inside space of air conditioner casing 6 through the duct, the air flow is oriented to a desired direction defined by louvers 3 and blown onto perforated panel 2 and then enters vent holes 12. As illustrated in FIG. 4, the air flow blown onto perforated panel 2 and entering respective vent holes 12 is indicated by solid line. Here, the air flow forms an angle with respect to vent hole 12, specifically, with respect to nozzle portion 12a of perforated panel 2. The angle is represented by angle θ formed between the direction of the air flow that is blown onto perforated panel 2 and a direction of the nozzle length “h” of vent hole 12. The direction of the nozzle length “h” is indicated by long and short dashed lines in FIG. 4. The angle θ is hereinafter referred to as wind axis angle θ. The wind axis angle θ is set within a range from 30 degrees to 60 degrees, and preferably within a range from 40 degrees to 50 degrees.

By setting the wind axis angle θ within the above-described specific range, the air flow blown out through vent hole 12 can be diverted at a wide angle that is larger than the wind axis angle θ, and oriented toward the outer surface of perforated plate 2 as indicated by dotted line in FIG. 4. In particular, depending on the shape of the end portion of air conditioner casing 6 which defines supply opening 9, the wind axis angle θ at vent holes 12 formed in the outer peripheral portion of perforated plate 2 can be set larger than the wind axis angle θ at vent holes 12 formed in a central portion of perforated plate 2. It is preferable to set the wind axis angle θ at vent holes 12 of a desired portion of perforated plate 2 in which the air flow blown out through vent holes 12 is to be oriented at a wide angle, within the above-described specific range. Accordingly, if the wind axis angle θ is set within the above-described specific range in the desired portion of perforated plate 2, the air flow blown out through vent holes 12 of the desired portion thereof can be diverted at a wide angle.

An evaluation test was carried out as follows to evaluate a relationship between wind axis angle θ, thickness “t” of the perforated plate and ratio (%) of diversion angle of the air flow blown out through the vent holes of the perforated plate to wind axis angle θ. The diversion angle was an angle formed between the direction of the air flow blown out from the outlet opening of the vent holes and the direction of the nozzle length. An air flow was blown to vent holes of a punching metal as the perforated plate at a speed that was set to a value usually used in an air conditioner. The test was conducted by changing the number of the punching metals used from 0 to 4. The test conditions were: wind axis angle θ: 10°, 40°and 50°; thickness “t” of each punching metal: 0.5 mm. Table 1 shows results of the evaluation test.

TABLE 1
Wind		Number of Punching metals
axis		(thickness of perforated panel)
angle			1	2	3	4
(°)		0	(0.5 mm)	(1.0 mm)	(1.5 mm)	(2.0 mm)
10	Orientation	Diversion	—	8	6	5	4
	properties	angle (°)
		Ratio (%)	—	80	60	50	40
	Ventilation resistance	16	32	33	34	35
	(Pa)
40	Orientation	Diversion	—	42	25	12	0
	properties	angle (°)
		Ratio (%)	—	105	63	30	0
	Ventilation resistance	41	50	61	65	69
	(Pa)
50	Orientation	Diversion	—	55	25	12	0
	properties	angle (°)
		Ratio (%)	—	110	50	24	0
	Ventilation resistance	58	90	100	98	98
	(Pa)

As seen from Table 1, when the wind axis angle θ was 10° and the thickness “t” of the perforated panel was changed from 0.5 mm to 2.0 mm, namely, the number of the punching metals used was changed from 1 to 4, the air flow blown out from the vent holes was diverted only at the diversion angle smaller than the wind axis angle θ of 10°. The ratio (%) of the diversion angle to the wind axis angle θ was in the range of 80% to 40% as shown in Table 1. On the other hand, when the wind axis angle θ was 40° and the thickness “t” of the perforated panel was 0.5 mm, namely, one sheet of the punching metal was used, the air flow blown out from the vent holes was diverted at the diversion angle larger than the wind axis angle θ of 40° and the ratio (%) of the diversion angle to the wind axis angle θ was 105%. Similarly, in the case of the wind axis angle θ of 50° and the thickness “t” of the perforated panel was 0.5 mm, the air flow blown out from the vent holes was diverted at the diversion angle larger than the wind axis angle θ of 50° and the ratio (%) of the diversion angle to the wind axis angle θ was 110%. Thus, in these cases, the diversion angle of the air flow blown out from the vent holes was increased to the wide angle larger than the wind axis angle θ to thereby direct the air flow toward the outer surface of the punching metal as the perforated panel.

When the wind axis angle θ was 40° and the thickness “t” of the perforated panel was changed from 1.0 mm to 2.0 mm by using two to four sheets of the punching metal, the air flow blown out from the vent holes was diverted at the diversion angle smaller than the wind axis angle θ of 40° and the ratio (%) of the diversion angle to the wind axis angle θ was 63% to 0%. When the wind axis angle θ was 50° and the thickness “t” of the perforated panel was changed from 1.0 mm to 2.0 mm by using two to four sheets of the punching metal, the air flow blown out from the vent holes was diverted at the diversion angle smaller than the wind axis angle θ of 50° and the ratio (%) of the diversion angle to the wind axis angle θ was 50% to 0%. Thus, in these cases, the diversion angle of the air flow blown out from the vent holes was not increased to the wide angle larger than the wind axis angle θ.

It has been found that by adjusting the thickness of the perforated panel, namely, the nozzle length of the vent holes, and the wind axis angle within the above-described specific ranges, the diversion angle of the air flow blown out from the vent holes becomes larger than the wind axis angle.

The perforated panel of the above embodiments of the present invention can be applied to the conventional air conditioner to thereby readily perform a wide-angled diversion of the air flow blown out through the perforated panel. Further, even if the perforated panel of the above embodiments of the present invention is applied to the conventional air conditioner in which the air flow direction that is defined by the louvers is varied in a small range, the air flow blown out through the perforated panel can be supplied over a wide-angled range. Further, the perforated panel of the above embodiments of the present invention can ensure supply of the air flow over a wide-angled range even under condition that an acute angle is formed between the outer surface of the perforated panel to which the vent holes are open, and a direction of the air flow which is defined by the louvers, to thereby cause poor orientation of the air flow blow out. Furthermore, the perforated panel of the above embodiments of the present invention can ensure supply of the air flow over a wider-angled range in combination with a diffusion vent.

Further, the construction and arrangement of the louvers, the duct, the air conditioner casing, the link mechanism, the actuator dial, and the mount position of the perforated panel are not limited to those as described in the embodiments. The louvers may be a stationary louver that is prevented from pivotally moving.

This application is based on a prior Japanese Patent Application No. 2005-052297 filed on Feb. 28, 2005. The entire contents of the Japanese Patent Application No. 2005-052297 is hereby incorporated by reference.

Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art in light of the above teachings. The scope of the invention is defined with reference to the following claims.

Claims

1. An air conditioner for a vehicle, comprising:

an air conditioner casing with a supply opening through which an air flow is blown into a vehicle compartment; and

a perforated panel with a plurality of vent holes, the perforated panel extending over the supply opening of the air conditioner casing;

wherein the plurality of vent holes each extend through the perforated panel and each have an inlet opening that is exposed to an inside of the air conditioner casing, an outlet opening that is exposed to an interior of the vehicle compartment and a nozzle length that extends from the inlet opening to the outlet opening, the nozzle length being within a range from 0.3 mm to 0.8 mm.

2. The air conditioner as claimed in claim 1, wherein a ratio of a sum of opening areas of the vent holes to a surface area of the perforated panel is within a range from 55% to 65%.

3. The air conditioner as claimed in claim 1, wherein each of the vent holes has a circular shape.

4. The air conditioner as claimed in claim 1, wherein the vent holes comprise generally rectangular shaped slits, and a ratio between a short side of the generally rectangular shaped slits and a long side thereof is within a range from 1:3 to 1:8.

5. The air conditioner as claimed in claim 1, wherein an angle of a direction of the air flow that is blown onto the perforated panel with respect to a direction of the nozzle length of the vent holes is within a range from 30 degrees to 60 degrees.

6. The air conditioner as claimed in claim 1, wherein an angle of a direction of the air flow that is blown onto the perforated panel with respect to a direction of the nozzle length of the vent holes is within a range from 40 degrees to 50 degrees.

7. The air conditioner as claimed in claim 1, wherein the perforated panel comprises a plurality of nozzle portions formed on an inner surface of the perforated panel which is exposed to the supply opening of the air conditioner casing, and the vent holes extend through the nozzle portions.

8. The air conditioner as claimed in claim 1, wherein the perforated panel is made of metal.

9. The air conditioner as claimed in claim 1, wherein the perforated panel is made of fabric.

10. The air conditioner as claimed in claim 1, wherein the perforated panel is made of synthetic resin.

11. The air conditioner as claimed in claim 1, further comprising a louver that is disposed below the perforated panel and arranged within the air conditioner casing, the louver being operative to define a direction of the air flow that is blown onto the perforated panel.

12. An air conditioner for a vehicle, comprising:

an air conditioner casing with a supply opening through which an air flow is blown into a vehicle compartment;

a panel extending over the supply opening of the air conditioner casing; and

means for diverting a direction of the air flow that is blown out through the panel, the means extending through the panel over a length that ranges from 0.3 mm to 0.8 mm.

13. The air conditioner as claimed in claim 12, wherein the means comprises a plurality of vent holes, and a ratio of a sum of opening areas of the vent holes to a surface area of the panel is within a range from 55% to 65%.

14. The air conditioner as claimed in claim 12, wherein the means comprises a plurality of circular-shaped vent holes.

15. The air conditioner as claimed in claim 12, wherein the means comprises a plurality of vent holes in the form of generally rectangular-shaped slits, and a ratio between a short side of the generally rectangular-shaped slits and a long side thereof is within a range from 1:3 to 1:8.

16. The air conditioner as claimed in claim 12, wherein an angle of a direction of the air flow that is blown onto the panel with respect to a direction of the length of the means is within a range from 30 degrees to 60 degrees.

17. The air conditioner as claimed in claim 12, wherein an angle of a direction of the air flow that is blown onto the panel with respect to a direction of the length of the means is within a range from 40 degrees to 50 degrees.

18. The air conditioner as claimed in claim 12, wherein the means comprises a plurality of vent holes, the panel comprises a plurality of nozzle portions that are formed on an inner surface of the panel which is exposed to the supply opening of the air conditioner casing, and the vent holes extend through the nozzle portions.

19. The air conditioner as claimed in claim 12, wherein the panel is made of metal.

20. The air conditioner as claimed in claim 12, wherein the panel is made of fabric.

21. The air conditioner as claimed in claim 12, wherein the panel is made of synthetic resin.

22. The air conditioner as claimed in claim 12, further comprising a louver that is disposed below the panel and arranged within the air conditioner casing, the louver being operative to define a direction of the air flow that is blown onto the panel.