JP2004338670A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently cool a switching element for controlling the action of a power source of a fan or a compressor assembled into an air conditioner for a vehicle without causing a noise such as a wind-cutting sound by a heat release fin and increase of ventilation resistance against an air stream. <P>SOLUTION: A by-pass passage 30 for forming rectified air along a heat sink 20 is formed on an air flow passage D without changing a mounting position of the conventional heat sink 20 arranged without causing the noise such as the wind-cutting sound and increase of the ventilation resistance against the air stream. Heat releasing function of the heat sink 20 is enhanced by the air stream flowing in the by-pass passage 30. Thereby, a power transistor 19 mounted to the heat sink 20 is efficiently cooled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle air conditioner provided in a vehicle such as an automobile, and in particular, to efficiently cool a switching element that controls an operation of a power source of a blower or a compressor incorporated in a vehicle air conditioner. The present invention relates to a vehicle air conditioner that can be used.
[0002]
[Prior art]
For example, in a vehicle air conditioner provided in a vehicle such as an automobile, a blower for taking in air from outside air is provided, and a heat exchanger for cooling an air flow is provided in an air flow path from the blower. Is provided. The power transistor, which is a switching element for controlling the drive source of the blower, automatically changes the operation of the blower in accordance with, for example, changes in the outside air temperature and the vehicle interior temperature in order to maintain the cabin comfort. In order to protect against malfunction due to heat generation of the power transistor itself, a heat sink for heat dissipation is provided in the power transistor, and the power transistor attached to the heat sink is cooled effectively by using air sent from a blower. Therefore, the heat sink to which the power transistor is attached is arranged in the air flow path from the blower. In this case, the heat sink is provided near the heat exchanger disposed in the air flow path so as to prevent a problem such as wind noise caused by the radiation fins and a problem of air flow resistance to the air flow. It is mounted upstream of the heat exchanger (for example, see Patent Document 1).
[0003]
The heat sink arranged in the air flow path near the heat exchanger is radiated by heat exchange with the air flow without causing a large turbulence in the air flow in the air flow path, thereby cooling the power transistor. You.
[0004]
[Patent Document 1]
JP-A-10-203132 (Section 2-4, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, since the heat exchanger is provided near the heat sink on the downstream side of the air flow path where the heat sink is provided, the heat exchanger disturbs the flow of air along the heat sink. . Therefore, generation of rectification along the heat radiation fins is prevented, so that air stagnates between the heat sink and the heat exchanger disposed close to the heat sink. This stagnation of air causes a decrease in the heat dissipation function of the heat sink. In particular, in order to enhance the heat exchange efficiency of the heat exchanger for cooling the airflow from the blower, a diameter-enlarged portion is formed in the air flow path, and the heat exchanger for cooling is arranged in the diameter-increased portion. In this case, since the heat sink is disposed in the recess between the end wall of the step defining the diameter increasing portion and the heat exchanger, the air in the recess stagnates. Therefore, it has been desired to prevent the stagnation of the air and to further enhance the cooling effect of the power transistor.
[0006]
Therefore, an object of the present invention is to provide a switching element for controlling the operation of a power source of a blower or a compressor incorporated in a vehicle air conditioner to cause an increase in airflow resistance against noise and airflow such as wind noise caused by radiating fins. It is an object of the present invention to provide a vehicle air conditioner that efficiently cools the vehicle.
[0007]
[Means for Solving the Problems]
SUMMARY OF THE INVENTION The present invention is directed to generating rectified air along a conventional heat sink without changing the mounting position of a conventional heat sink that is arranged without increasing wind resistance to noise and noise such as wind noise. Is formed on the air flow path, and the airflow flowing through the bypass path enhances the heat dissipation function of the heat sink.
[0008]
That is, according to the first aspect of the present invention, the compressed air is compressed by the compressor which is arranged across the pipe defining the air flow path from the blower operated by the first drive source and is operated by the second drive source. An air conditioner for a vehicle including a heat exchanger that exchanges heat between a refrigerant and an air flow flowing through the air flow path. The air conditioner for a vehicle according to the present invention includes a heat sink attached to a peripheral wall surface of the pipe near the heat exchanger on the upstream side of the air flow path from the heat exchanger; Switching elements for controlling the operation of the driving source. At least one of the switching elements is attached to the heat sink. In the vehicle air conditioner according to the present invention, one end opens to the air flow path through an opening formed in a wall portion of the peripheral wall to which the heat sink is attached, and the other end is closer than the heat exchanger. A bypass path is provided that opens to the air flow path through an opening formed in the peripheral wall surface downstream of the air flow path.
[0009]
According to the first aspect of the present invention, even if a heat sink is attached to the peripheral wall surface of the pipe near the heat exchanger on the upstream side of the air flow path from the heat exchanger, the air flowing into the bypass formed in the air flow path The flow prevents stagnation of air near the heat sink provided in the opening, thereby enhancing the heat radiation function of the heat sink and efficiently cooling the switching element via the heat sink.
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, the pipe has an increased diameter portion defined by a step, and the heat exchanger is spaced from an end wall of the step. And the heat sink is attached to the peripheral wall surface between the end wall of the step portion and the heat exchanger.
[0011]
According to the second aspect of the present invention, the diameter increasing portion is formed in the air flow path in order to increase the heat exchange rate of the heat exchanger for cooling the airflow from the blower. The heat sink will be disposed in the recess between the end wall of the step defining the increased diameter portion and the heat exchanger.However, the formation of the bypass passage creates an airflow flowing into the bypass passage. There is no stagnation of air in this recess. As a result, rectification is formed along the heat sink, so that the heat exchange rate of the heat exchanger for cooling the airflow from the blower is increased, and the heat dissipation function of the heat sink is enhanced.
[0012]
According to a third aspect of the present invention, in the first aspect of the present invention, a rib extending from an edge of the opening into the opening is formed in the opening of the bypass passage at which the one end is opened, and the heat sink is The rib is supported at a distance from an edge of the opening.
[0013]
According to the third aspect of the present invention, the rib extending into the opening from the edge of the opening where one end of the bypass path is opened forms a gap between the edge of the opening and the heat sink, and the heat sink is provided substantially at the center from the edge of the opening. Is supported. Thereby, rectification along the heat sink is appropriately formed.
[0014]
According to a fourth aspect of the present invention, in the first aspect of the present invention, the bypass is formed of a semi-cylindrical member having both ends closed and disposed on the outer wall of the pipe so as to cover the openings. It is characterized by.
[0015]
According to the fourth aspect of the present invention, an opening formed in the wall surface portion to which the heat sink is attached is formed on the peripheral wall surface of the pipe that defines the air flow from the blower, and the peripheral portion is formed on the downstream side of the air flow path from the heat exchanger. Rather than being formed by a tubular member, a bypass passage arranged to connect the opening formed in the wall surface is formed by a semi-cylindrical member which is disposed over the opening on the outer wall of the tube and is closed at both ends. A bypass path is formed. Therefore, when it is fixed to the vehicle air conditioner main body as a separate member, the member can be fixed to the outer wall of the pipe in a straight line, not in a curved line, and the mounting property is improved. Further, when a member is formed by resin molding, a mold for obtaining the member can be simplified as compared with a tubular member.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram schematically showing a configuration of a vehicle air conditioner 10 according to the present invention. As shown in FIG. 1, the vehicle air conditioner 10 includes an intake unit 11 for selectively taking in outside air from outside the vehicle or inside air inside the vehicle, and a cooling unit 12 for cooling air taken in through the intake unit 11. Is provided.
[0017]
The intake unit 11 is provided with an outside air intake and an inside air intake (not shown) for sucking outside air or inside air, and a blower 13 provided with a blower fan for taking in the air. . When the blower 13 is operated by the blower motor M, which is a drive source of the blower 13, outside air is selectively introduced into the unit case 14 from the outside air intake and inside air from the inside air intake, and the outside air or the inside air is taken into the intake unit 11. Through the air passage D passing through the cooling unit 12 to the cooling unit 12 on the downstream side.
[0018]
The cooling unit 12 is provided with a heat exchanger that exchanges heat between the refrigerant compressed by the compressor C and the airflow flowing from the blower 13 through the air flow path D, that is, an evaporator 15. In order to increase the heat exchange rate of the evaporator 15, a diameter increasing portion 16 is formed in the air flow path D. The diameter increasing portion 16 is formed continuously from the intake unit 11 and is defined by a step portion 18 having an end wall 17. When the air flow flowing from the blower 13 through the air flow path D flows into the cooling unit 12, the flow velocity is reduced at the diameter increasing portion 16 where the diameter of the air flow path is increased, and the heat exchange rate of the evaporator 15 is reduced. Enhanced.
[0019]
A power transistor 19 and a heat sink 20 for cooling the power transistor 19 are arranged in a recess between the end wall 17 of the step 18 defining the diameter increasing portion 16 and the evaporator 15. In the example shown in FIG. 1, the power transistor 19 is a switching element for controlling the rotation of the blower motor M. As will be described later, the power transistor 19 is mounted on the back surface of the heat sink 20 and together with the heat sink 20, the air flows in the recess. It is fixed to the peripheral wall surface of the flow path D.
[0020]
When the evaporator 15 receives the supply of the compressed cooling medium from the compressor C by the operation of the compressor C having a variable discharge capacity connected thereto, the evaporator 15 is taken into the intake unit 11 by the supplied cooling medium and the blower 13. This intake air is cooled by heat exchange with air. Thereafter, the air cooled by the evaporator 15 and hot air from a heater core (not shown) using, for example, engine cooling water as a heat source are mixed, and the air adjusted to an appropriate temperature is supplied into the vehicle interior.
[0021]
In the vehicle air conditioner 10, as shown in FIG. 1, an opening 21 is formed in a peripheral wall surface of a cooling unit 12 of the vehicle air conditioner body to which a heat sink 20 is attached. An opening 22 is formed on the peripheral wall downstream of the opening 21, that is, on the peripheral wall of the air flow path D downstream of the evaporator 15. The U-shaped tube member 23 is disposed outside the wall 16a of the diameter-increasing portion 16 in a side view, such that one end of the tube member 23 opens to the opening 21 and the other end opens to the opening 22. Both ends of the pipe member 23 are connected to the wall 16 a of the cooling unit 12. As a result, a bypass 23a for the air flow path D flowing through the diameter increasing portion 16 is formed. By forming the bypass passage 23, a part of the air flow flowing through the air flow passage D flows into the bypass passage 23, so that the bypass air flow B is formed, and the diameter increasing portion 16 is defined by the bypass air flow B. The stagnation of air in the recess between the end wall 17 of the step 18 and the evaporator 15 is prevented.
[0022]
The power transistor 19 and the heat sink 20 are mounted in the recess where air does not stagnate as shown in FIG. That is, the heat sink 20 includes a base 24 and a plurality of radiating fins 25 extending from the base 24 in one direction in parallel with each other. The power transistor 19 is mounted in contact with the back surface of the base 24 so that heat can be sufficiently conducted from the power transistor 19 to the radiation fins 25.
[0023]
As shown in FIGS. 2 and 3, the heat sink 20 to which the power transistor 19 is attached has the radiation fin 25 extending in the opening 21 along the center line of the opening 21 and the radiation fin 25 facing the air flow path D. Are located. The heat sink 20 is fixed by a screw member 28 to a plurality of ribs 26 formed to extend from the edge of the opening 21 into the opening. As a result, the heat sink 20 is supported substantially at the center from the edge of the opening 21 with a gap 27 between the heat sink and the edge of the opening 21. Since the gap 27 is formed, the power transistor 19 and the heat sink 20 do not block the airflow in the bypass passage 23, and heat exchange between the bypass airflow B flowing through the bypass passage 23 and the heat sink 20 is promoted. In addition, the heat radiation function of the heat sink 20 is enhanced. As a result, the power transistor 19 attached to the heat sink 20 is effectively cooled.
[0024]
Therefore, according to the first embodiment, the bypass airflow B can be generated by forming the bypass passage 23 that opens to the air flow passage D as described above. It is possible to prevent stagnation of air in the recess between the end wall 17 of the step 18 defining the step 16 and the evaporator 15. Therefore, the heat dissipation effect of the heat sink 20 arranged in the opening 21 can be enhanced, and the power transistor 19 attached to the heat sink 20 can be efficiently cooled.
[0025]
<Embodiment 2>
Embodiment 2 of the present invention will be described with reference to FIG. 4 and FIG. FIG. 4 is a schematic diagram showing an example in which the bypass passage 23a is formed of another member instead of the U-shaped tube member 23. In FIG. 4, the same reference numerals as in FIG. 1 denote the same functional parts as those shown in FIG. 1 except for the members constituting the bypass path 23a.
[0026]
In the example shown in FIG. 5, the bypass path 29a is formed by the semi-cylindrical member 29. The semi-cylindrical member 29 includes a pair of semi-circular end walls 30, 30 arranged in parallel with each other at intervals, and a peripheral wall 31 connecting the arc-shaped edges of the semi-circular end walls 30, 30. , And the pair of end walls 30, 30 constitute a closed end of the semi-cylindrical member 29. In the semi-cylindrical member 29, a rectangular opening 34 is defined by both side edges 32, 32 of the peripheral wall and chords 33, 33 of the end walls 30, 30. The semi-cylindrical member 29 is positioned such that the openings 21 and 22 for the bypass are located in the opening 34 and the semi-cylindrical member 29 receives the heat sink 20 and the power transistor 19 attached to the opening 21. , 19, and 20 are disposed on the wall 16a of the increased diameter portion 16 of the cooling unit 12. The edge of the opening 34 of the semi-cylindrical member 29 is air-tightly fixed to the wall 16a, and the semi-cylindrical member 29 allows the bypass passage 29a communicating between the openings 21 and 22 as in the case of the tube member 23. Is formed.
[0027]
The bypass passage 29a formed by the semi-cylindrical member 29 is more secure than the bypass passage 23a formed by the U-shaped pipe member 23 when it is fixed to the vehicle air conditioner body as a separate member by welding or the like. Since the surface can be fixed to the vehicle air conditioner main body in a straight line instead of a curved line, the mounting becomes easier. Further, when the semi-cylindrical member 29 is formed by resin molding, a mold for obtaining the semi-cylindrical member 29 can be simplified as compared with the tube member 23, and the semi-cylindrical member 29 is integrally formed with the wall 16a by resin. It can be formed by molding.
[0028]
Therefore, according to the second embodiment of the present invention, the use of the semi-cylindrical member 29 makes it possible to more easily form the bypass.
[0029]
In Embodiments 1 and 2 described above, in order to increase the heat exchange rate of the evaporator 15 for cooling the airflow from the blower 13, the increased diameter portion 16 is formed in the air flow path D, and the heat sink 20 and the power transistor 19 are formed. Has described the case where it is disposed in a recess between the end wall 17 of the step portion 18 defining the diameter increasing portion 16 and the evaporator 15.
[0030]
However, an opening 21 is provided in the wall of the air flow path D having a uniform diameter without providing the cooling unit 12 with a diameter increasing portion, and a heat sink having a power transistor similar to that described above is disposed. Thus, a bypass similar to that described above can be formed. By the bypass airflow flowing through the bypass passage, the heat radiation function of the heat sink can be enhanced as described above.
[0031]
Further, in the above-described example, the power transistor 19 for automatically controlling the operation of the blower motor M, which is the drive source of the blower 13, is provided on the heat sink. Instead, the compressor C of the evaporator 15 is provided on the heat sink. A switching element such as a power transistor for controlling the operation of the driving motor can be provided.
[0032]
If there is enough heat radiation capacity of the heat sink, both the switching element 19 for the blower motor M and the switching element for the motor of the compressor C can be attached to this one heat sink.
[0033]
If there is room in the opening of the bypass path, both heat sinks for the respective switching elements can be arranged in the opening.
[0034]
【The invention's effect】
According to the first aspect of the present invention, even if the heat sink is mounted at the same position as the conventional one on the upstream side of the air flow path from the heat exchanger, the opening is formed by the bypass air flow flowing into the bypass path formed in the air flow path. The stagnation of air near the heat sink provided in the portion is prevented, whereby the heat radiation effect of the heat sink is enhanced, and the switching element attached to the heat sink can be efficiently cooled.
[0035]
According to the second aspect of the present invention, by providing the bypass, it is possible to prevent stagnation of air in the concave portion related to the increased diameter portion of the air flow path, and to reduce noise such as wind noise caused by the radiation fins. Since the heat radiation effect of the heat sink in the recess can be increased without increasing the airflow resistance to the airflow, the heat exchange rate of the heat exchanger can be increased, and the switching element attached to the heat sink can be efficiently used. Can be cooled.
[0036]
According to the third aspect of the present invention, the heat sink can be supported at a distance from the edge of the opening by the rib formed so as to extend into the opening of the bypass passage. The air flow can be appropriately formed.
[0037]
According to the fourth aspect of the present invention, since the bypass can be formed by a semi-cylindrical member having both ends closed, the bypass can be formed relatively easily.
[Brief description of the drawings]
FIG. 1 is a schematic diagram schematically showing a configuration of a first embodiment of a vehicle air conditioner according to the present invention.
FIG. 2 is a cross-sectional view showing an enlarged main part of the present invention.
FIG. 3 is a view taken in the direction of arrows III-III in FIG. 2;
FIG. 4 is a schematic diagram schematically showing a configuration of a vehicle air conditioner according to a second embodiment of the present invention.
FIG. 5 is a perspective view showing a semi-cylindrical member for forming a bypass.
[Explanation of symbols]
10 vehicle air conditioner 13 blower 15 heat exchanger (evaporator)
16 Diameter increasing part 17 End wall 18 Step part 19 Switching element (power transistor)
Reference Signs List 20 heat sink 21, 22 opening 23a, 29a bypass passage 26 rib 29 semi-cylindrical member D air passage C compressor (compressor)

Claims (4)

An air flow flowing through the air flow path and a refrigerant arranged across a pipe defining an air flow path from a blower operated by a first drive source and compressed by a compressor operated by a second drive source; A vehicle air conditioner including a heat exchanger that performs heat exchange between
A heat sink attached to the peripheral wall of the tube near the heat exchanger on the upstream side of the air flow path than the heat exchanger;
Switching elements for automatically controlling the operation of the first and second drive sources,
At least one of the switching elements is attached to the heat sink,
One end is opened to the air flow path through an opening formed in the wall surface portion on which the heat sink is mounted on the peripheral wall surface, and the other end is formed on the peripheral wall surface on the downstream side of the air flow path from the heat exchanger. An air conditioner for a vehicle, comprising: a bypass that opens to the air flow path through a formed opening. The pipe is formed with a diameter increasing portion defined by a step, the heat exchanger is arranged at a distance from an end wall of the step, and the heat sink is connected to the end wall of the step and the heat exchanger. The vehicle air conditioner according to claim 1, wherein the air conditioner is attached to the peripheral wall surface between the air conditioner and the vehicle. A rib extending from the edge of the opening into the opening is formed in the opening at which the one end of the bypass path opens, and the heat sink is supported by the rib at a distance from the edge of the opening. The vehicle air conditioner according to claim 1, wherein: 2. The vehicle air conditioner according to claim 1, wherein the bypass passage is formed by a semi-cylindrical member having both ends closed and arranged on the outer wall of the pipe so as to cover the openings. 3.

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