JP2005059807A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformize the distribution of air velocity in a heat exchanger while suppressing an increase in ventilation resistance in an air conditioner for a vehicle in which the heat exchanger is disposed immediately after a square-shaped bent passage. <P>SOLUTION: A curved part 17 formed in a smooth curved shape is formed on the curved inner part of the bending passage 13. By this, blowing air is allowed to flow along the curved surface of the curved part 17 by the Coanda effect, and the overall flow of the blowing air can be pulled to the curved part 17 by preventing air flow from being separated at a bent inner part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement for making the wind speed distribution of air passing through a heat exchanger in a vehicle air conditioner uniform.

  The indoor air conditioning unit in the vehicle air conditioner is generally divided into a blower unit and an air conditioning unit in which air is blown from the blower unit. As is well known, the air conditioning unit is provided with devices such as a cooling heat exchanger, a heating heat exchanger, a temperature adjustment mechanism, and a blow-out mode switching mechanism.

  A layout (blower offset arrangement) in which the blower unit is offset on the front side of the passenger seat inside the instrument panel at the front of the passenger compartment and the air conditioning unit is located near the center in the vehicle lateral direction (vehicle width direction) inside the instrument panel Layout) has become mainstream in recent years. In this blower offset layout, the blown air from the blower unit flows in the left-right direction of the vehicle from the front side of the passenger seat toward the air conditioning unit near the center.

  On the other hand, the air passage in the case of the air conditioning unit is formed in the vehicle front-rear direction, an air inlet space is formed in the foremost part in this case, and a cooling heat exchanger is arranged in the rear part of the air inlet space in the vehicle In addition, a heating heat exchanger is arranged at the rear of the vehicle after the cooling heat exchanger.

  Therefore, a right-angled bent passage that changes the flow of the blown air from the blower unit to a right angle is formed on the air inlet side of the cooling heat exchanger. For this reason, blown air changes the flow direction at right angles and flows into the heat exchanger for cooling.

  As a result, the area on the side away from the blower unit of the cooling heat exchanger is affected by the separation of the air flow at the bending inner wall surface in the right-angled bending passage, the inertial force of the air flow in the vehicle lateral direction, etc. The wind speed distribution is high, and the wind speed in the area close to the blower unit is low. Due to this non-uniform wind speed distribution, the cooling performance of the cooling heat exchanger deteriorates.

  Therefore, conventionally, it has been proposed to eliminate the nonuniformity of the wind speed distribution of the cooling heat exchanger in the fan offset arrangement layout by means as shown in FIGS. 9 and 10 (see, for example, Patent Document 1). .

  FIG. 9 shows that step portions 14a and 14b are formed on the front wall surface of the case 14 of the air conditioning unit 11 that faces the air inlet surface of the cooling heat exchanger 15, and the blower unit is formed by the step portions 14a and 14b. The direction of the air flow to the region (the left region in the figure) close to the air is promoted, and the wind speed distribution in the cooling heat exchanger 15 is made uniform.

FIG. 10 is a diagram in which rectifying guides 18 a and 18 b are provided in the upstream space of the air inlet surface of the cooling heat exchanger 15 to make the air velocity distribution in the cooling heat exchanger 15 uniform.
JP-A-8-72530

  By the way, the stepped portions 14a and 14b of the case 14 shown in FIG. 9 are arranged at the outer side of the bending passage 13 where the air flow direction is changed to a right angle, and the rectifying guides 18a and 18b shown in FIG. Since it is arranged at the flow center part of the bending passage 13 and both change the air flow in the positive pressure field of the bending passage 13, the wind speed distribution is determined by the arrangement of the step portions 14a and 14b and the rectifying guides 18a and 18b. When trying to equalize, the increase in ventilation resistance becomes remarkable.

  In view of the above points, the present invention provides a vehicle air conditioner in which a heat exchanger is disposed immediately after a bending passage that changes the direction of air flow to a right angle, while suppressing an increase in ventilation resistance. The purpose is to make the wind speed distribution uniform.

To achieve the above object, according to the first aspect of the present invention, in the vehicle air conditioner in which the air blown into the vehicle interior flows through the right-angled bending passage (13),
A heat exchanger (15) for exchanging heat with the air is disposed immediately after the bending passageway (13),
A curved portion (17) having a smooth curved surface shape is formed in the bent inner portion of the bending passage (13).

  According to this, since the blown air can flow along the curved surface of the curved portion (17) by the Coanda effect, the air flow is prevented from being separated at the bent inner portion of the right-angled bent passage (13), and the blown air is prevented. The entire flow can be drawn toward the bending portion (17) side of the bending inner portion.

  As a result, the reverse flow of the air flow in the bent inner portion or the low wind speed region can be eliminated and the wind speed distribution of the heat exchanger (15) can be made uniform. In addition, the air flow distribution is uniformed by drawing the entire flow of the blown air toward the bent portion (17) side of the bent inner portion, so that an increase in ventilation resistance is suppressed compared to the prior art of FIGS. it can.

  According to a second aspect of the present invention, in the first aspect, the curved portion (17) has a predetermined amount (δ) from the upstream side wall surface (12a) of the bending passage (13) toward the inner side of the bending passage (13). ) It is formed so as to protrude.

  According to the study of the present inventor, by forming the curved portion (17) in a protruding shape toward the inside of the bending passage as in claim 2, the effect of preventing peeling due to the Coanda effect is increased, and the heat exchanger ( It has been confirmed that the effect of uniforming the wind speed distribution in 15) can be further improved.

  In invention of Claim 3, in Claim 1 or 2, the case (14) which accommodates the said heat exchanger (15), The connection duct (12) connected to the upstream part of the said case (14), The bending passage (13) is formed in the vicinity of the connection portion between the connection duct (12) and the case (14), and the bending portion (17) is integrally formed with the connection duct (12). It is characterized by that.

  Thereby, the above-mentioned effect of uniforming the wind speed distribution can be exhibited by the curved portion (17) formed integrally with the connecting duct (12).

  In invention of Claim 4, in Claim 1 or 2, the case (14) which accommodates the said heat exchanger (15), The connection duct (12) connected to the upstream part of the said case (14), The bending passage (13) is formed in the vicinity of the connecting portion between the connecting duct (12) and the case (14), and the bending portion (17) is integrally formed with the case (14). It is characterized by.

  Thereby, the above-mentioned wind speed distribution uniformization effect can be exhibited by the curved part (17) integrally formed in the case (14) on the heat exchanger (15) side.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
FIG. 1 shows a case where the vehicle air conditioner according to the first embodiment is applied to a right-hand drive vehicle. FIG. 2 is an enlarged view of a main part of FIG. In the present embodiment, the indoor air conditioning unit of the vehicle air conditioner is roughly divided into a blower unit 10 and an air conditioning unit 11 that blows air from the blower unit 10.

  The blower unit 10 is disposed on the front side of the passenger seat inside the instrument panel (not shown) in the front part of the passenger compartment, and the air conditioning unit 11 is disposed near the center in the vehicle left-right direction (vehicle width direction) inside the instrument panel. The That is, the blower unit 10 is offset from the air conditioning unit 11 on the side of the passenger seat. Note that the front, rear, left, and right arrows in FIG. 1 indicate directions in a vehicle-mounted state.

  The blower unit 10 has a centrifugal blower fan 10a driven by a motor (not shown), and the blower fan 10a is housed in a resin scroll casing 10b. The suction side of the scroll casing 10b faces the vehicle upper side (the front side in FIG. 1). A well-known inside / outside air switching box (not shown) is provided on the suction side of the scroll casing 10b, and inside air or outside air is sucked into the blower fan 10a through the inside / outside air switching box.

  The blow-out part of the scroll casing 10b is directed to the right side of the vehicle, and this blow-out part is connected to the front air inlet space of the air conditioning unit 11 through a resin-made connecting duct 12. The air conditioning unit 11 has a case 14 formed of resin, and an air passage through which air flows from the vehicle front side toward the vehicle rear side is formed in the case 14. Therefore, an air inlet space is formed at the foremost part in the case 14.

  A right-angled bent passage 13 is formed from the outlet portion of the connecting duct 12 to the foremost air inlet space in the case 14. The bending passage 13 changes the air flow flowing in the vehicle left-right direction through the connecting duct 12 from the blowing portion of the scroll casing 10b to the vehicle front-rear direction flow.

  In the case 14, the cooling heat exchanger 15 is disposed immediately after the bending passage 13, in other words, immediately after the front air inlet space in the case 14. The cooling heat exchanger 15 is composed of an evaporator of a well-known refrigeration cycle, and absorbs the latent heat of evaporation of the refrigerant from the blown air to cool the blown air.

  As shown in FIG. 2, the cooling heat exchanger 15 includes a large number of flat tubes 15a arranged in parallel in the left-right direction of the vehicle, and corrugated fins 15b integrally joined between the flat tubes 15a. The heat exchange core part is provided, and air passes through the gap of the heat exchange core part from the vehicle front side toward the vehicle rear side.

  The flat tube 15a is arranged so as to extend in the vertical direction in the case 14, and the side plates 15c are arranged so as to extend in the vertical direction on both left and right sides of the heat exchange core part.

  In the case 14, a heating heat exchanger 16 that heats air using hot water (engine cooling water) as a heat source is disposed on the downstream side (vehicle rear side) of the cooling heat exchanger 15. In addition, in the case 14, other devices such as an air mix door and a blowing mode switching mechanism that form a well-known temperature adjusting mechanism (not shown) are arranged. The conditioned air whose temperature has been adjusted by passing through the heating heat exchanger 16 is blown into the vehicle interior from one or a plurality of air outlets selected by the air outlet mode switching mechanism.

  In this embodiment, the scroll casing 10b, the connecting duct 12, the case 14, and the like of the blower unit 10 constitute an “air passage through which air flows into the vehicle interior”. In this air passage, a bending passage 13 in which the air flow is bent at a right angle is formed in the vicinity of the upstream portion of the cooling heat exchanger 15. Due to the right-angled bending passage 13, the above-described non-uniformity of the wind speed distribution in the cooling heat exchanger 15 occurs.

  Therefore, in the present embodiment, the following specific configuration is adopted in order to make the wind speed distribution uniform in the cooling heat exchanger 15. First, step portions 14a and 14b are formed on the foremost wall surface of the case 14 facing the cooling heat exchanger 15 as in the prior art of FIG. The stepped portions 14 a and 14 b are formed in a region (a vehicle left side region) on the side close to the blower unit 10 on the foremost wall surface of the case 14, and the blown air from the blower fan 10 a is included in the cooling heat exchanger 15. The direction change to the left side area close to the blower unit 10 is promoted.

  In the present embodiment, the stepped portions 14a and 14b are provided in two stages at a predetermined interval in the left-right direction of the vehicle, and the stepped portion 14b that is further away from the blower unit 10 than the stepped portion 14a that is close to the blower unit 10 is cooled. It is formed so as to be close to the heat exchanger 15 for use. And the taper-shaped wall surface 14c which adjoins gradually toward the heat exchanger 15 for cooling in the site | part which leaves | separates from the air blower unit 10 rather than the level | step-difference part 14b is formed. By these stepped portions 14 a and 14 b and the tapered wall surface 14 c, the space upstream of the cooling heat exchanger 15 is narrowed away from the blower unit 10.

  Further, in addition to the above, a curved portion 17 having a smooth curved surface shape is formed on the bending inner side portion of the right-angled bending passage 13 (that is, the side where the passage bending radius is small). The curved portion 17 may be a complete arc shape with a predetermined radius of curvature, or a curved surface shape that smoothly connects a plurality of arc shapes with different curvature radii. In this embodiment, the curved portion 17 is integrally formed at the outlet portion of the resin connecting duct 12 as shown in FIG.

  Next, the effect of this embodiment is demonstrated. FIG. 3 is an explanatory diagram of the air flow in the portion of FIG. 2 in the present embodiment, while FIGS. 4 and 5 are comparative examples corresponding to FIGS. In this comparative example, the bending inner portion of the bending passage 13 formed in the upstream portion of the cooling heat exchanger 15 is substantially perpendicular, and the bending portion 17 of the present embodiment is not formed.

  According to the comparative example of FIGS. 4 and 5, since the bent inner portion of the bending passage 13 is substantially perpendicular, separation of the air flow occurs on the wall surface of the right passage and the inertia force of the air flow (vehicle The inertial force from the left side to the right side) causes the air flow to go in a direction substantially parallel to the inlet surface of the cooling heat exchanger 15 as indicated by an arrow a.

  As a result, a negative pressure region is formed in the bending inner portion of the bending passage 13, and a reverse flow of the air flow is generated. For this reason, in the heat exchanger 15 for cooling, in the left side region (b portion in FIG. 5) close to the blower unit 10, the air flow is backflowed or at a low wind speed, and the cooling performance of the heat exchanger 15 for cooling is reduced. Cause.

  On the other hand, according to the present embodiment, since the curved portion 17 having a smooth curved surface shape is formed in the bent inner portion of the right-angled bending passage 13, the blown air is made into the curved surface of the curved portion 17 by the Coanda effect. Along the direction of the arrow c in FIG. Thereby, peeling of the air flow in the bending inner part of the right-angled bending passage 13 can be prevented, and the entire flow of the blown air can be drawn toward the bending part 17 side of the bending inner part.

  As a result, the reverse flow of the air flow or the low wind speed region can be eliminated, and the wind speed distribution of the cooling heat exchanger 15 can be made uniform. And since the uniform wind speed distribution is achieved by drawing the whole flow of blast air toward the bending part 17 side of a bending inner side part, the increase in ventilation resistance can be suppressed.

(Second Embodiment)
In the second embodiment, as shown in FIGS. 6 and 7, the bending portion 17 is formed from the upstream side wall surface of the bending passage 13, specifically, from the vehicle rear side wall surface 12 a of the connecting duct 12 toward the inner side of the bending passage 13. A smooth protruding shape is formed so as to protrude a predetermined amount δ.

  According to the study of the present inventor, by forming the curved portion 17 in such a protruding shape, the effect of preventing peeling due to the Coanda effect is increased, and the effect of uniformizing the wind speed distribution of the cooling heat exchanger 15 is further increased. It has been confirmed that it can be improved.

  Note that the amount of protrusion δ of the curved portion 17 is, for example, about 6 mm when the width dimension W of the connecting duct 12 is 50 mm, so that the effect of uniforming the wind speed distribution of the cooling heat exchanger 15 can be satisfactorily exhibited. Have confirmed.

(Third embodiment)
In the third embodiment, as shown in FIG. 8, an inlet duct portion 14d protruding toward the connecting duct 12 side is integrally formed in the case 14 of the air conditioning unit 11, and a curved portion 17 is integrally formed in the inlet duct portion 14d. Yes. In FIG. 8, the curved portion 17 having the curved surface shape (FIG. 2) of the first embodiment is formed. However, the curved portion 17 having the protruding curved surface shape (FIG. 7) of the second embodiment is used as the case. It may be formed integrally with the 14 inlet duct portions 14d.

(Other embodiments)
In a vehicle air conditioner for cold districts, only the heating heat exchanger 16 may be disposed in the air conditioning unit 11 and the cooling heat exchanger 15 may not be disposed. In that case, the heating heat exchanger 16 may be disposed immediately after the bending passage 13. You may apply this invention to the vehicle air conditioner which has such a structure.

It is sectional drawing which shows schematic structure of 1st Embodiment of this invention. It is a principal part enlarged view of FIG. It is explanatory drawing of the air flow in FIG. It is sectional drawing which shows schematic structure of the comparative example of 1st Embodiment. It is explanatory drawing of the air flow of the principal part of FIG. It is sectional drawing which shows schematic structure of 2nd Embodiment. It is a principal part enlarged view of FIG. It is a principal part enlarged view of 2nd Embodiment. It is sectional drawing which shows schematic structure of a prior art. It is sectional drawing which shows schematic structure of another prior art.

Explanation of symbols

12 ... Connection duct, 13 ... Bending passage, 14 ... Case, 15 ... Heat exchanger for cooling,
17 ... curved portion.

Claims (4)

In the vehicle air conditioner in which the air blown into the passenger compartment flows through the right-angled bending passage (13),
A heat exchanger (15) for exchanging heat with the air is disposed immediately after the bending passageway (13),
A vehicular air conditioner characterized in that a curved portion (17) having a smooth curved surface is formed in a bent inner portion of the bent passage (13). The curved portion (17) is formed so as to protrude a predetermined amount (δ) from the upstream side wall surface (12a) of the bending passageway (13) toward the inside of the bending passageway (13). Item 2. The vehicle air conditioner according to Item 1. A case (14) for housing the heat exchanger (15), and a connecting duct (12) connected to an upstream portion of the case (14),
The bending passage (13) is formed in the vicinity of a connection portion between the connection duct (12) and the case (14),
The vehicle air conditioner according to claim 1 or 2, wherein the curved portion (17) is integrally formed with the connecting duct (12). A case (14) for housing the heat exchanger (15), and a connecting duct (12) connected to an upstream portion of the case (14),
The bending passage (13) is formed in the vicinity of a connection portion between the connection duct (12) and the case (14),
The vehicle air conditioner according to claim 1 or 2, wherein the curved portion (17) is integrally formed with the case (14).

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