JP2008037363A - Vehicular air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a vehicular air conditioner attaining reduction of manufacturing cost and prevention of dew deposition. <P>SOLUTION: In the vehicular air conditioner, a compressor 10, a condenser 11, an expansion valve 13 and an evaporator 5 stored in an air-conditioning case 4 and cooling suction air are connected in the order by a coolant pipe. Of the coolant pipe, an inlet pipe 5a for introducing the coolant evaporated in the evaporator 5 to a suction side of the compressor 10, an outlet pipe 5b and a coolant outlet pipe 14b are provided, and coating by coating having foaming property on an outer surface is formed on the inlet pipe 5a, the outlet pipe 5b and the coolant outlet pipe 14b. Thereby, reduction of the manufacturing cost and prevention of dew deposition are attained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner that air-conditions a vehicle interior, and more particularly to prevention of dew condensation and reduction of heat loss of a low-pressure refrigerant pipe disposed outside an air conditioning case.

Conventionally, what is shown by patent document 1 is known as this kind of an air conditioner, for example. That is, this air conditioner is accommodated in an air conditioning case, an evaporator that cools intake air, an expansion valve that is connected to the evaporator and disposed outside one end surface of the air conditioning case, and is connected to the expansion valve. The expansion valve is provided with a heat insulating case including the outer shell thereof, and the refrigerant inlet / outlet pipe is covered with a heat insulating member for heat insulation.
JP 2002-29251 A

  However, according to the above-mentioned patent document 1, the number of man-hours for forming the heat insulating case and the heat insulating member separately, and the man-hours for assembling these heat insulating materials to the expansion valve and the refrigerant inlet / outlet pipe are required.

  In other words, there is a problem that the manufacturing cost increases because the number of manufacturing steps for heat insulation is large. In particular, if the refrigerant inlet / outlet pipe connected to the evaporator is formed in a complicated shape, the heat insulating member may be manually attached to increase the number of assembling steps.

  Accordingly, an object of the present invention is to provide a vehicle air conditioner that can reduce manufacturing costs and prevent dew condensation.

In order to achieve the above object, the technical means described in claim 1 and claim 2 are employed. That is, in the invention described in claim 1, the evaporator (5) that is accommodated in the compressor (10), the condenser (11), the expansion valve (13), and the air conditioning case (4) and cools the intake air. In the vehicle air conditioner connected in order by refrigerant piping,
Among the refrigerant pipes, there are provided low-pressure refrigerant pipes (5a, 5b, 14b) for guiding the refrigerant evaporated in the evaporator (5) to the suction side of the compressor (10). 5b, 14b) is characterized in that the outer surface is coated with foaming paint.

  According to this invention, in the manufacturing process, the number of painting steps for heat insulation is required, but the manufacturing cost can be reduced by greatly reducing the number of assembling steps. In addition, the coating with foaming paint can prevent the low-pressure refrigerant pipes (5a, 5b, 14b) from being exposed and reduce heat loss.

  The invention according to claim 2 is characterized in that the expansion valve (13) is disposed outside the one end face of the air conditioning case (4) and the outer surface is coated with a foaming paint. It is said.

  According to the present invention, the number of manufacturing steps can be significantly reduced as compared with the case where the heat insulating case is formed separately. In addition, the application of foaming paint can prevent the expansion valve (13) from being exposed and reduce heat loss.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment mentioned later.

  Hereinafter, a vehicle air conditioner according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram showing the overall configuration of a vehicle air conditioner. FIG. 2 is a perspective sectional view showing one end face of the air conditioning case.

  The air conditioning unit 1 has an inside / outside air switching means 2 for selecting whether the air to be sent into the vehicle interior is air inside the vehicle (inside air) or outside air (outside air), and the air selected by the inside / outside air switching means 2 is used. Air blowing means 3 for blowing air into the vehicle interior, an air conditioning case 4 as an air passage for guiding air from the air blowing means 3 into the vehicle interior, an evaporator 5 as a cooling means for cooling the air flowing in the air conditioning case 4, and air conditioning A temperature adjusting means 6 for adjusting the temperature of air blown from the case 4 into the vehicle interior is provided.

  The inside / outside air switching means 2 is provided at an upstream side of the air blowing means 3 and has an inside air inlet 2a communicating with the vehicle interior and an outside air inlet 2b communicating with the outside of the vehicle interior. An inside / outside air switching door 2c for selectively opening and closing 2a and the outside air inlet 2b is provided. The inside / outside air switching door 2c is driven by a driving means such as a servomotor (not shown), and is used for an inside air circulation mode in which inside air is sucked from the inside air suction port 2a, and outside air is sucked from the outside air suction port 2b. Switch to outside air introduction mode.

  The air blowing means 3 is connected to the air upstream side portion of the air conditioning case 4 and generates air flow for blowing air into the vehicle interior. The air blowing means 3 includes a fan case 3a, a fan 3b, and a fan motor 3c. The fan motor 3c rotates and drives the fan 3b according to the voltage applied from the drive circuit, and the inside air or the outside air is passed through the air conditioning case 4. Ventilate into the passenger compartment.

  The air conditioning case 4 is disposed in front of the vehicle interior. On the outlet side of the air conditioning case 4, there are a face air outlet 7 for blowing air that has passed through the air conditioner case 4 toward the upper body of the passenger in the passenger compartment, and a foot air outlet 8 for blowing the air toward the feet of the passenger. And the defroster blower outlet 9 for blowing off the said air toward the window glass of a motor vehicle is formed.

  In the air conditioning case 4, there are provided means for adjusting the amount of air flowing through the air outlets 7, 8, and 9, specifically, a face door 7a, a foot door 8a, and a defroster door 9a. These doors 7a, 8a, 9a are driven by respective driving means, specifically, servo motors (not shown).

  The temperature adjusting means 6 includes a heater core 6a and an air mix door 6b. The heater core 6a is formed with a hot air passage 6c through which the air from the evaporator 5 passes through the heater core 6a and a bypass passage 6d through which the air from the evaporator 5 bypasses the heater core 6a at the downstream side of the evaporator 5. It arrange | positions so that. The heater core 6a is a heat exchanger in which engine cooling water flows and heats the air in the air conditioning case 4 that passes through the heater core 6a by the heat of the engine cooling water.

  The air mix door 6b is provided on the upstream side of the heater core 6a and is driven by driving means such as a servo motor. In accordance with the position set by the servo motor, the air outlet ratio is adjusted by adjusting the air volume ratio between the amount of air that passes through the hot air passage 6c and is heated by the heater core 6a and the amount of air that passes through the bypass passage 6d. The temperature of the blowing temperature blown out is adjusted.

  Next, the evaporator 5 is a component of the refrigeration cycle that cools the air that passes through the air conditioning case 4. The evaporator 5 is disposed upstream of the air in the air conditioning case 4 and cools the air that passes through the air conditioning case 4. The refrigeration cycle is a well-known one that includes the compressor 10, the condenser 11, the liquid receiver 12, and the expansion valve 13 in addition to the evaporator 5.

  The evaporator 5 and the expansion valve 13 are disposed in the passenger compartment, and the compressor 10, the condenser 11, and the liquid receiver 12 are disposed in the engine room. The compressor 10 is rotationally driven by transmission of rotational power of an engine (not shown) via an electromagnetic clutch (not shown), and operates the refrigeration cycle so that the evaporator 5 functions as a cooling means.

  One end surface of the expansion valve 13 is connected to the inlet pipe 5 a and the outlet pipe 5 b of the evaporator 5, and the other end face is connected to the refrigerant inlet pipe 14 a that communicates with the liquid receiver 12 and the refrigerant outlet pipe 14 b that communicates with the compressor 10. It is a box type expansion valve.

  The expansion valve 13 accommodates a temperature sensing unit that detects the refrigerant temperature on the outlet side of the evaporator 5, decompresses and expands the high-temperature and high-pressure liquid refrigerant that has passed through the liquid receiver 12, and The refrigerant flow rate is adjusted by detecting the outlet temperature of the evaporator 5 so as to maintain an appropriate degree of superheat at the outlet.

  Moreover, the expansion valve 13 is arrange | positioned outside the one end surface of the air-conditioning case 4, as shown in FIG. The other end face is connected to a refrigerant inlet pipe 14 a that communicates with the liquid receiver 12 and a refrigerant outlet pipe 14 b that communicates with the compressor 10. Here, high-pressure refrigerant flows through the refrigerant inlet pipe 14a, and low-pressure refrigerant flows through the inlet pipe 5a, the outlet pipe 5b, and the refrigerant outlet pipe 14b. In the claims, the inlet pipe 5a, the outlet pipe 5b, and the refrigerant outlet pipe 14b through which the low-pressure refrigerant flows are referred to as a low-pressure refrigerant pipe.

  By the way, when the refrigeration cycle is activated, the expansion valve 13, the inlet pipe 5 a, the outlet pipe 5 b, and the refrigerant outlet pipe 14 b disposed outside the one end face of the air conditioning case 4 are exposed to heat absorption by the evaporator 5. Will occur. In order to insulate, it is common to arrange so that the outer surface of each of these components 5a, 5b, 13, 14a is covered with a heat transfer member.

  Therefore, in the present embodiment, at least a portion indicated by a two-dot chain line in FIGS. 1 and 2 in the manufacturing process, that is, the entire outer surface of the expansion valve 13 including the inlet pipe 5a and the outlet pipe 5b, and the refrigerant outlet pipe. A heat insulating layer is formed on the outer surface of 14b by coating with a foaming paint.

  More specifically, first, the expansion valve 13 is formed integrally with an inlet pipe 5a and an outlet pipe 5b, and thereafter, an expansion valve including the inlet pipe 5a and the outlet pipe 5b in a painting process. A heat insulating layer is formed on the entire outer surface of 13. Further, a heat insulating layer is formed on the outer surface of the refrigerant outlet pipe 14b in the painting process. Here, the heat insulation layer by a foamed film is formed after painting by painting using the paint which has foamability.

  According to the vehicle air conditioner in the above embodiment, the outlet pipe 5b for guiding the refrigerant evaporated in the evaporator 5 to the suction side of the compressor 10 and the refrigerant outlet pipe 14b among the refrigerant pipes are provided. In the manufacturing process, the outlet pipe 5b and the refrigerant outlet pipe 14b are coated with a foaming paint on the outer surface.

  Thereby, compared with the conventional system which arrange | positions a heat-transfer member, especially the assembly man-hour which assembles a heat-transfer member can be reduced significantly, and reduction of manufacturing cost can be aimed at. Further, the coating with foaming paint can prevent the outlet pipe 5b and the refrigerant outlet pipe 14b from being dewed, and can reduce the heat loss leaked from the outlet pipe 5b and the refrigerant outlet pipe 14b.

  In addition, the expansion valve 13 is coated with foaming paint on the outer surface, so that the number of manufacturing steps can be greatly reduced compared to the conventional method in which a heat insulation case is formed separately and assembled to the expansion valve 13. Can be small. Therefore, the manufacturing cost can be reduced. In addition, the coating with foaming paint can prevent the expansion valve 13 from being dewed, and can reduce the heat loss leaked from the expansion valve 13.

  In addition, if the dew condensation occurs on the expansion valve 13, the inlet pipe 5 a, the outlet pipe 5 b, and the refrigerant outlet pipe 14 b disposed outside the one end surface of the air conditioning case 4, there is a possibility that condensed water may drip into the vehicle interior. However, this defect can be prevented by forming a heat insulating layer by painting.

(Other embodiments)
In the above embodiment, the outer surface of the refrigerant outlet pipe 14b through which the low-pressure refrigerant circulates is coated with a foaming paint to form the heat insulating layer. The heat insulating layer may be formed by coating the outer surface of the circulating refrigerant inlet pipe 14a with a foaming paint. According to this, the heat loss leaking from the refrigerant inlet pipe 14a can be reduced.

  In the above embodiment, the box-shaped expansion valve 13 having a built-in temperature sensing portion has been described. However, the present invention can also be applied to a temperature type expansion valve having an external temperature sensing portion.

It is a mimetic diagram showing the whole vehicle air-conditioner composition in one embodiment of the present invention. It is a perspective sectional view showing one end surface of air-conditioning case 4 in one embodiment of the present invention.

Explanation of symbols

4 ... Air-conditioning case 5 ... Evaporator 5a ... Inlet pipe (low-pressure refrigerant pipe)
5b ... Outlet pipe (low-pressure refrigerant pipe)
DESCRIPTION OF SYMBOLS 10 ... Compressor 11 ... Condenser 13 ... Expansion valve 14a ... Refrigerant outlet piping (low-pressure refrigerant piping)

Claims (2)

A vehicle air conditioner in which a compressor (10), a condenser (11), an expansion valve (13), and an evaporator (5) for cooling intake air are connected in order by a refrigerant pipe, in an air conditioning case (4). In the device
Among the refrigerant pipes, low-pressure refrigerant pipes (5a, 5b, 14b) for guiding the refrigerant evaporated in the evaporator (5) to the suction side of the compressor (10) are provided,
The vehicle air conditioner, wherein the low-pressure refrigerant pipe (5a, 5b, 14b) is coated with a foaming paint on the outer surface.   The said expansion valve (13) is arrange | positioned outside the one end surface of the said air-conditioning case (4), and the coating by the paint which has foamability is formed in the outer surface. Vehicle air conditioner.

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