JP2000283606A - Refrigeration cycled apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce heat loss in a piping section upon the operation of hot gas bypassing. SOLUTION: Taking notice of a fact that a gas refrigerant is sharply reduced in its temperature (e.g. changes from the state of 20 kgf/cm2, 70 deg.C to the state of 2 kgf/cm2, 40 deg.C) before and behind a pressure reducer in a hot gas bypass passage 19, there is provided a second pressure reducer 21 at an inlet section of the hot gas bypass passage 19 for reducing the pressure of hot gas. Hereby, the hot gas lowered in temperature after the pressure reduction flows through the hot gas bypass passage 19, so that heat loss at a piping section of the hot gas bypass passage 19 can be effectively reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas refrigerant (hot gas) discharged from a compressor during heating, which is depressurized by bypassing a condenser side and directly introduced into an evaporator, whereby the gas refrigerant is radiated by the evaporator. The present invention relates to a refrigeration cycle device having a hot gas bypass function, and in particular, has been improved so as to effectively suppress heat radiation in a pipe portion during a hot gas bypass operation. It is suitable for use.

[0002]

2. Description of the Related Art Conventionally, in a vehicle air conditioner, hot water (engine cooling water) is circulated through a heating heat exchanger during winter heating,
The heating heat exchanger heats the conditioned air using hot water as a heat source. In this case, when the temperature of the hot water is low, the temperature of the air blown into the vehicle interior may decrease, and the necessary heating capacity may not be obtained.

[0003] Japanese Patent Laid-Open Publication No. Hei 5-223357 proposes a refrigeration cycle apparatus that can exhibit a heating function by hot gas bypass. In this conventional apparatus, a hot gas bypass passage is provided which bypasses the condenser from the compressor discharge side and directly communicates with the evaporator inlet side, and a pressure reducing means is provided in the hot gas bypass passage so that the hot water temperature is reduced as in starting the engine. Is lower than the predetermined temperature, the compressor discharge gas refrigerant (hot gas) is decompressed by the decompression means of the hot gas bypass passage and then directly introduced into the evaporator, and the evaporator radiates heat from the gas refrigerant to the conditioned air, thereby heating The function can be demonstrated.

[0004]

By the way, in the above-mentioned conventional apparatus, the amount of compression work in the compressor ideally becomes the amount of heat radiation (heating capacity) in the evaporator. Therefore, the heat loss (radiation amount) to the outside at the piping portion of the hot gas bypass passage directly leads to a decrease in performance. In particular, the gas temperature immediately after the discharge of the compressor is, for example, 70 at a discharge pressure of 20 kgf / cm ^2.
° C, and the temperature difference from the outside air temperature during winter heating: -20 ° C becomes very large. Accordingly, when the length of the pipe until the pressure of the hot gas is reduced, the heat loss of the hot gas increases.

[0005] The present invention has been made in view of the above points,
It is an object of the present invention to reduce heat loss in a pipe portion during a hot gas bypass operation. Another object of the present invention is to reduce the propagation of the gas flow noise at the time of pressure reduction in the hot gas bypass passage to the evaporator section.

[0006]

According to the present invention, before and after the pressure reducing device in the hot gas bypass passage (19), the temperature of the gas refrigerant drops greatly (for example, 20 kgf / cm ² , 7 kg).
It is intended to reduce the heat loss in the pipe part by focusing on the fact that the temperature changes from 0 ° C. to 2 kgf / cm ² and 40 ° C.).

[0007] That is, the first aspect of the present invention is characterized in that a second pressure reducing device (21) for reducing the pressure of the hot gas is disposed upstream of the hot gas bypass passage (19). Here, the hot gas bypass passage (19)
The arrangement upstream of the hot gas bypass passage (1
The arrangement relationship in which the length of the passage upstream of the second pressure reducing device (21) is shorter than the length of the passage downstream of the second pressure reducing device (21) in 9).

According to the first aspect of the present invention, the hot gas having a reduced temperature after depressurization flows through most of the hot gas bypass passage (19).
9) The heat loss in the piping section can be effectively reduced. Moreover, since the second pressure reducing device (21) is located on the upstream side of the hot gas bypass passage (19), the evaporator (17)
Since the second pressure reducing device (21) can be disposed at a considerable distance from the room in which the gas is installed, the effect of reducing the propagation of the gas flow noise at the time of pressure reduction in the hot gas bypass passage (19) to the room can be reduced. You can play together.

Further, according to the invention described in claim 2, according to claim 1,
, The valve means (12, 20, 400) is arranged upstream of the hot gas bypass passage (19), and the valve means (1
2, 20, 400) is characterized by incorporating a second pressure reducing device (21). According to this, the valve means (12,
20 and 400) and the second decompression device (21) can be integrated, and the second decompression device (21) is configured by reducing the flow path cross-sectional area of the valve port in the valve means (12, 20, and 400). The structure can be simplified, and a dedicated piping joint for the second pressure reducing device (21) is not required,
Cost can be reduced.

[0010] According to the third aspect of the present invention, the first aspect is provided.
Or 2 is characterized in that the second pressure reducing device (21) is arranged at the inlet of the hot gas bypass passage (19). According to this, the hot gas bypass passage (1)
Since hot gas whose temperature has dropped after decompression flows through almost the entirety of 9), heat loss in the piping portion of the hot gas bypass passage (19) can be reduced more effectively.

Further, according to the invention described in claim 4, according to claim 1,
In any one of (a) to (c), the second pressure reducing device (2
A gas flow noise suppressing member (234) for reducing the range of formation of the gas ejection flow by colliding with the gas ejection flow ejected from the second decompression device (21) is provided at the outlet portion of 1). . According to this, the formation range of the gas ejection flow is reduced, and the gas flow noise can be effectively reduced.

Further, according to the invention described in claim 5, according to claim 1,
In any one of (a) to (c), the second pressure reducing device (2
A feature of the present invention is that a tapered passage portion (50) for gradually increasing the cross-sectional area of the passage is formed at the outlet portion of 1). According to this, by forming the tapered passage portion (50), the second passage is formed.
The decrease in the refrigerant pressure immediately after the pressure reducing device (21) can be moderated. Therefore, the second pressure reducing device (21)
It is possible to prevent the sound velocity of the refrigerant flow velocity from becoming sonic due to the sudden drop in pressure in the immediately following portion, thereby reducing the refrigerant flow noise.

[0013] According to the invention described in claim 6, according to claim 1 of the present invention.
In any one of (5) to (5), a tapered passage portion (165) for gradually increasing the cross-sectional area of the passage is formed at the outlet junction of the hot gas bypass passage (19). According to this, by the formation of the tapered passage portion (165), it is possible to moderate the decrease in the refrigerant pressure at the bypass passage outlet junction. For this reason, it is possible to prevent a phenomenon in which the refrigerant flow velocity becomes sonic due to a sudden drop in pressure at the bypass passage outlet junction, thereby reducing the refrigerant flow noise.

According to the seventh aspect of the present invention, the first aspect is provided.
In any one of (a) to (c), the second pressure reducing device (2
A first tapered passage (50) for gradually increasing the cross-sectional area of the passage is formed at the outlet of (1), and the cross-sectional area of the passage is gradually increased at the junction of the outlet of the hot gas bypass passage (19). Forming a second tapered passage portion (165), and the taper angle (θ _f ) of the first tapered passage portion (50).
Is within 12 °, and the second tapered passage portion (165)
Is characterized in that the taper angle (θ _r ) is within 15 °.

According to this, both the portion immediately after the second pressure reducing device (21) and the refrigerant pressure drop at the bypass passage outlet junction can be moderated, and the first and second tapered passage portions can be reduced. By setting the taper angles (θ _f , θ _r ) of (50, 165) within 12 ° and 15 °, respectively, the effect of reducing the refrigerant flow noise can be more effectively exerted.

According to the present invention, the first-stage restricting means includes a restricting hole (223) arranged on the upstream side of the hot gas bypass passage (19), and the downstream side of the first-stage restricting portion. A second tube (19a ') arranged at
It is characterized in that the second pressure reducing device (21) is constituted by the step throttle means. According to this, the hot gas which has been decompressed by the first-stage restricting means on the upstream side of the hot gas bypass passage (19) and whose temperature has dropped is formed by the second thin tube (19a ').
It flows through the step drawing means. In addition, since the second pressure reducing device (21) is a two-stage throttle and the second-stage throttle means is constituted by the thin tube (19a '), the surface area (that is, the heat radiation area) of the thin tube (19a') can be reduced. With the thin tube (19
The flow velocity of the refrigerant in a ') can be increased, and together with these, the heat loss in the piping portion of the hot gas bypass passage (19) can be reduced more effectively.

In the case where the second pressure reducing device (21) is a one-stage throttle, the second pressure reducing device (21) responds to the increase in the specific volume of the refrigerant after the pressure reduction.
Although it is necessary to increase the pipe diameter on the downstream side of the pressure reducing device (21), according to the invention described in claim 8, the downstream side of the first-stage restrictor is provided by the second-stage restrictor comprising a thin tube (19a ') as described above. With this configuration, the piping space can be reduced, and the piping can be easily arranged in a narrow space such as a vehicle.

According to the ninth aspect of the present invention, the eighth aspect of the present invention is provided.
, The valve means (12, 20, 400) is arranged upstream of the hot gas bypass passage (19), and the valve means (1
2, 20, 400) with a built-in throttle hole (223). According to this, the valve means (12, 2
0, 400) and the first-stage throttle unit, the same cost reduction effect as in the above-described claim 2 can be exhibited.

According to a tenth aspect of the present invention, in any one of the eighth and ninth aspects, the throttle hole (223) is disposed at an inlet of the hot gas bypass passage (19). According to this, as in the case of the third aspect, the hot gas having a reduced temperature after depressurization flows through almost the entire hot gas bypass passage (19), and the heat loss in the pipe portion can be reduced more effectively.

If the valve means is constituted by a three-way switching valve (400), the condenser (13) and the hot gas bypass passage (10) are arranged from the discharge side of the compressor (10). The switching of the refrigerant flow to 19) can be performed by one valve, and the size and cost of the valve means can be reduced. According to a twelfth aspect of the present invention, there is provided an air conditioner for a vehicle using the refrigeration cycle device according to any one of the first to eleventh aspects, wherein the air conditioning unit (23) includes an evaporator (17). Are disposed in the vehicle compartment, and the second pressure reducing device (21) is disposed in the engine room.

According to this, by arranging the second pressure reducing device (21) in the engine room considerably away from the cabin where the evaporator (17) is installed, the pressure in the hot gas bypass passage (19) can be reduced. Propagation of the gas flow noise into the vehicle interior can be reduced. According to a thirteenth aspect of the present invention, in the twelfth aspect, the compressor (10) is disposed in an engine room and driven by the vehicle engine, and the hot gas bypass passage (19) is located near the vehicle engine. It is characterized in that it is arranged at a position receiving heat.

According to this, since the hot gas bypass passage (19) receives heat from the vehicle engine, heat loss in the piping portion of the hot gas bypass passage (19) can be effectively reduced. Note that the reference numerals in parentheses attached to the respective means indicate the correspondence with specific means described in the embodiment described later.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 3 show a first embodiment in which the present invention is applied to a refrigeration cycle device in a vehicle air conditioner. In FIG. 1, a compressor 10 includes an electromagnetic clutch 1
1 through a water-cooled vehicle engine (not shown). The discharge side of the compressor 10 is connected to a condenser 13 via a first solenoid valve (cooling valve means) 12, and the outlet side of the condenser 13 is a receiver for separating gas-liquid refrigerant and storing liquid refrigerant. Connected to the vessel 14.

The outlet side of the liquid receiver 14 is connected to a temperature type expansion valve (first pressure reducing device) 15. The thermal expansion valve 15 is provided with a check valve 1 at the outlet side of the expansion valve body 150.
6 is integrally incorporated, and the outlet side of the check valve 16 is connected to the inlet side of the evaporator 17. Expansion valve body 150
As is well known, the evaporator 18 is operated during a normal refrigeration cycle operation.
The valve opening (refrigerant flow rate) is adjusted so that the degree of superheat of the outlet refrigerant is maintained at a predetermined value.

The outlet side of the evaporator 17 is connected to the expansion valve body 150.
After passing through the flow path of the temperature sensing part 150a inside, it is connected to the inlet side of the accumulator 18. As is well known, the accumulator 18 separates the gas-liquid of the refrigerant, stores the liquid refrigerant, and derives the gas refrigerant.
0 is connected to the suction side. On the other hand, a hot gas bypass passage 19 is provided from the discharge side of the compressor 10 to the inlet side of the evaporator 17 (the outlet side of the check valve 16), bypassing the condenser 13 and the like. A valve device 22 in which a second solenoid valve (heating valve means) 20 and a throttle (second pressure reducing device) 21 are integrated is disposed at an inlet of the bypass passage 19.

The evaporator 17 is installed in the case of the air conditioning unit 23 of the vehicle air conditioner, and cools air (vehicle air or outside air) blown by a blower (not shown) in a cooling mode and when dehumidification is required. In addition, the evaporator 17
In the winter heating mode, the high-temperature refrigerant gas (hot gas) flows from the hot gas bypass passage 19 to heat the air, and thus serves as a radiator.

In the case of the air conditioning unit 23, a hot water heating heat exchanger 24 for heating the blown air by using hot water (engine cooling water) from the vehicle engine as a heat source is installed downstream of the evaporator 17 in the air. The air-conditioning air is blown into the vehicle compartment from an air outlet (not shown) provided on the downstream side of the heating heat exchanger 24. Next, FIG. 2A shows a state in which the refrigeration cycle device is mounted on the vehicle. The air conditioning unit 23 containing the evaporator 17 is disposed at a position below the instrument panel at the front of the vehicle compartment. ,
All other devices are located in the vehicle engine room. In FIG. 2, 25 is a discharge side rubber hose of the compressor 10, 26 is a high-pressure metal pipe between the first solenoid valve 12 and the condenser 13, and 27 is a high-pressure metal pipe between the condenser 13 and the receiver 14. , 28 are high-pressure metal pipes between the receiver 14 and the thermal expansion valve 15.

The temperature-type expansion valve 15 is roughly composed of three parts: a first joint 151 integrally containing the above-described expansion valve main body 150, a check valve 16, and a second joint 152. The first joint 151 is the evaporator 1
7 is connected to the entrance / exit piping. The second joint 152 is connected to a downstream end of the high-pressure metal pipe 28 and an upstream end of the low-pressure metal pipe 29. The downstream end of the low-pressure metal pipe 29 is connected to the inlet of the accumulator 18, and the outlet of the accumulator 18 is connected to the suction side of the compressor 10 via the suction-side rubber hose 30.

The outlet of the metal pipe constituting the hot gas bypass passage 19 is connected to a bypass connection port of the first joint 151. As shown in FIG. 2B, a metal pipe 19a forming the hot gas bypass passage 19 is formed.
A heat insulating material 19b is attached to the outer peripheral surface of the, so as to suppress heat radiation from the internal refrigerant gas to the surrounding atmosphere.
As a specific material of the heat insulating material 19b, for example, a porous body such as ethylene propylene rubber (EPDM) is suitable, and its thickness is about 5 mm. The outer diameter of the metal pipe 19a constituting the hot gas bypass passage 19 is, in this example,
At 4/8 inch, its inner diameter is 10.1 mm.

Here, an example of the pipe diameter of another part of the refrigeration cycle will be described.
8 is an outer diameter: 4/8 inch, a valve diameter of the first solenoid valve 12: φ
11 mm, high-pressure metal pipe 26 on the inlet side of condenser 13 has an outer diameter of 4/8 inch, high-pressure metal pipe 2 on the outlet side of condenser 13
7 and the high-pressure metal pipe 28 on the outlet side of the receiver 14 have an outer diameter of 8
mm, the pipe between the expansion valve 15 and the inlet of the evaporator 17 has an outer diameter of 4/8 inch, and the suction side rubber hose 25 on the outlet side of the evaporator 17 has an outer diameter of 5/8 inch.

FIG. 3 illustrates a specific structure of the valve device 22 shown in FIG. 1. The valve device 220 includes a valve housing 220, and an inlet joint 221 is provided at one end of the valve housing 220.
Are formed. The inlet joint 221 is connected to the discharge side rubber hose 25 of the compressor 10. An outlet joint 222 is formed on the other end of the valve housing 220. This outlet joint 222 is connected to the inlet of the hot gas bypass passage 19.

A throttle hole (in other words, a valve port of the second solenoid valve 20) 223 is provided between the inlet joint portion 221 and the outlet joint portion 222. In this example, the throttle hole 223 is formed by the throttle hole 223. The above-described throttle (second pressure reducing device) 21 is configured. The aperture hole 223 is a circular hole having a diameter of 2.2 mm in this example. The solenoid valve 20 that opens and closes the throttle hole 223 has a pilot valve structure in this example, and has a main valve body 224. The main valve body 224 covers the outer peripheral surface of the resin body with a metal cover. It is a substantially cylindrical shape having a configuration covered with. A control hole 225 is formed in the center of the main valve body 224. On the other hand, a pilot valve portion 227 for opening and closing the control hole 225 is provided at the tip of the plunger 226.

Accordingly, when the plunger 226 moves upward in FIG. 3 and the pilot valve portion 227 opens the control hole 225, the back pressure chamber 228 of the main valve body 224 is opened via the control hole 225 and the throttle hole 223. The pressure in the back pressure chamber 228 is reduced by communicating with the passage on the joint part 222 side. Thereby, the pressure on the inlet joint part 221 side and the back pressure chamber 22
, A pressure difference is generated between the coil spring 2
The force of 29 acts on the main valve body 224 as an upward pressing force in FIG. This pressing force causes the main valve body 224 to move as shown in FIG.
, The throttle hole 223 is opened, and the solenoid valve 2
0 is in the valve open state. Then, the refrigerant gas on the compressor discharge side is reduced to a predetermined pressure by the throttle action of the throttle hole 223, and the reduced refrigerant gas flows into the hot gas bypass passage 19 via the outlet joint 222.

Next, an electromagnetic mechanism for attracting the plunger 226 upward in FIG. 3 will be described.
Is a movable member made of a magnetic material, and a fixed iron core member 230 is disposed facing the plunger 226.
A coil spring 231 is disposed between the coils 6 and 230. Further, an electromagnetic coil 232 is arranged on the outer peripheral side of the plunger 226 and the fixed core member 230, and a yoke member 233 is arranged around the electromagnetic coil 232.

Thus, when the electromagnetic coil 232 is energized, magnetic flux flows through the magnetic circuit composed of the yoke member 233, the plunger 226 and the fixed core member 230, and an attractive force is generated between the plunger 226 and the fixed core member 230. Then, the plunger 226 is displaced upward in FIG. 3 against the force of the spring 231. In the valve housing 220, a central portion between the inlet joint portion 221 on one end side and the outlet joint portion 222 on the other end side, and the throttle hole 223
The gas flow noise suppression member 234 is arranged immediately after the part. The gas flow noise suppressing member 234 is connected to the compressor 10.
This suppresses the gas flow noise caused by the gas jet flow (jet core) generated when the high-pressure refrigerant gas discharged from the nozzle is rapidly reduced in pressure in the throttle hole 223.

Specifically, the gas flow noise suppressing member 234 has a cylindrical portion 234 having an outer diameter (for example, φ4.0 mm) larger than the diameter of the throttle hole 223 (for example, φ2.2 mm).
a, and the tip of the cylindrical portion 234a is arranged at a position immediately after the throttle hole 223 with a predetermined interval L therebetween. Here, the predetermined interval L is set at 0. 0 with respect to the diameter d of the throttle hole 223.
The distance is about 5d to 3.0d. The gas refrigerant that has been decompressed through the throttle hole 223 collides with the tip of the cylindrical portion 234a, and then flows through the gap on the outer peripheral side of the cylindrical portion 234a to the flow path of the outlet joint portion 222.

The gas flow noise suppressing member 234 has a cylindrical portion 234.
a and a mounting portion 234b having a larger outer diameter than the above are integrally formed of metal or resin, and are fixed to the valve housing 220 via an O-ring 235 with screws. next,
The operation of the first embodiment in the above configuration will be described. In the cooling mode and when dehumidification is required, the control device (not shown) opens the first solenoid valve 12 for cooling and closes the second solenoid valve 20 for heating. Accordingly, when the electromagnetic clutch 11 is energized by the control device (not shown) and becomes connected, the compressor 10 is driven by the vehicle engine,
Activated.

Then, the gas refrigerant discharged from the compressor 10 passes through the first solenoid valve 12 in the open state and flows into the condenser 13, where the refrigerant is cooled by the outside air blown by a cooling fan (not shown). Cools and condenses. Then, the condensed liquid refrigerant is gas-liquid separated by the liquid receiver 14, and only the liquid refrigerant is depressurized by the expansion valve main body 150 of the temperature-type expansion valve 15 to be in a low-temperature low-pressure gas-liquid two-phase state.

Next, the low-pressure refrigerant flows into the evaporator 17 by opening the check valve 16 incorporated in the first joint 151 of the thermal expansion valve 15. In the evaporator 17, the refrigerant absorbs heat from the conditioned air blown by a blower (not shown) and evaporates. The conditioned air cooled by the evaporator 17 blows out into the vehicle compartment to cool the vehicle compartment. Then, the gas refrigerant evaporated in the evaporator 17 is sucked into the compressor 10 via the accumulator 18 and is compressed again.

In the winter heating mode, the cooling first electromagnetic valve 12 is closed by a control device (not shown),
The second heating solenoid valve 20 is opened. Second solenoid valve 2
In the open state of 0, the main valve body 224 is displaced upward in FIG. 3 to open the throttle hole 223 constituting the throttle 21, and the hot gas bypass passage 19 is opened. For this reason, the compressor 1
0 high temperature discharge gas refrigerant (superheated gas refrigerant)
After the pressure is reduced by the zero throttle hole 223, it flows into the evaporator 17 through the hot gas bypass passage 19. Evaporator 17
In, the deheated superheated gas refrigerant radiates heat to the conditioned air to heat the conditioned air.

In the hot gas bypass operation, the check valve 16 is kept closed by the pressure of the gas refrigerant from the bypass passage 19, so that the discharged gas refrigerant does not flow backward to the upstream side of the temperature type expansion valve 15. . Hot water heating heat exchanger 2
By flowing hot water from the vehicle engine to the air conditioner 3, the conditioned air can also be heated in the heat exchanger 23. Then, the gas refrigerant radiated by the evaporator 17 is sucked into the compressor 10 via the accumulator 18 and is compressed again.

By the way, the gas temperature immediately after discharge from the compressor is, for example, 70 ° C. at a discharge pressure of 20 kgf / cm ² , and the temperature difference from the outside air temperature during winter heating (eg, -20 ° C.) is very large. Become. However, according to the first embodiment, the second solenoid valve 20 is arranged at the inlet of the hot gas bypass passage 19, and the throttle hole 223 itself, which forms the valve port of the second solenoid valve 20, forms the hot gas bypass passage 19. 1
Since the nine throttles 21 are configured, the gas refrigerant whose temperature has dropped after the pressure in the hot gas bypass passage 19 has been reduced by the throttle holes 223 flows.

For example, the refrigerant gas is 20 k in the throttle hole 223.
When the pressure is reduced from gf / cm ² to 2 kgf / cm ² , the temperature of the refrigerant gas drops from 70 ° C. to 40 ° C. Accordingly, the temperature difference between the refrigerant gas in the hot gas bypass passage 19 and the ambient atmosphere temperature is reduced, so that the heat loss in the piping of the hot gas bypass passage 19 during the hot gas bypass operation can be reduced. Further, the heat insulating material 1 is provided on the outer peripheral surface of the pipe 19a of the hot gas bypass passage 19.
9b, the hot gas bypass passage 1
The heat loss in the piping section 9 can be further reduced.

Further, if the location near the vehicle engine is selected as the location of the hot gas bypass passage 19 and the piping of the hot gas bypass passage 19 receives the heat of the vehicle engine, the hot gas bypass passage 19 is provided. The heat loss in the piping section can be more effectively reduced. FIG. 4 is a Mollier diagram of the refrigeration cycle during the hot gas bypass operation, a broken line is a Mollier diagram in an ideal state where the heat loss in the piping portion of the hot gas bypass passage 19 is zero, and a solid line is the present invention described above. FIG. 4 is a Mollier diagram according to the first embodiment, and is a Mollier diagram according to a comparative example in which a throttle 21 is arranged at an intermediate position of a hot gas bypass passage 19.

In the first embodiment, the heating capacity can be increased from Q ₂ of the comparative example to Q ₁ by reducing the heat loss in the piping section of the hot gas bypass passage 19. FIG. 5 shows the power conversion efficiency, which is the ratio between the compressor power and the amount of heat released by the evaporator 17, when the vehicle is running at an outside air temperature of −20 ° C. and a vehicle speed of 40 km / h. 0.5
From 0.7 to 0.7.

Next, in the first embodiment, measures are taken to reduce noise in the throttle 21 of the hot gas bypass passage 19, and therefore, the measures for reducing noise will be described. First, referring to FIG.
Explaining the mechanism of noise generation in the throttle 21 of FIG.
Since the pressure is rapidly reduced from a high pressure state of about f / cm ² to a low pressure state of about 2 kgf / cm ² , a sonic gas jet (jet core) A is generated at the outlet side of the throttle 21.

This gas ejection flow A has a diameter d of the throttle 21 of 5 to 5.
The gas ejection flow A is formed in a range of about eight times.
A mixing zone B having a steep velocity gradient D is formed on the outer peripheral side of, and a turbulent flow zone C is formed downstream of the mixing zone B. Gas flow noise (noise) is generated due to the steep velocity gradient D formed in the mixing region B. As shown in FIG. 6B, this gas flow noise is particularly large in the range of the mixing region B.

Therefore, in the first embodiment, as shown in FIG. 7, a gas flow noise suppressing member 234 is disposed in the range of formation of the gas jet flow A so as to face the outlet of the throttle 21. The gas jet A is caused to collide with the tip surface of the member 234 so as to narrow the range in which the gas jet A forms the mixing area B. The gas flow noise is reduced by reducing the formation range of the mixing region B.

FIG. 8 shows the gas flow noise suppressing member 23 described above.
4 specifically shows the noise reduction effect of the refrigeration cycle. The operating condition of the refrigeration cycle is as follows:
° C, the amount of air blown into the evaporator 17: 150 m ³ / h, the number of revolutions of the compressor 10: 760 rpm, the upstream pressure of the throttle 21: 1.3 MPa, the downstream pressure of the throttle 21: 0.4 MP.
At a, the inner diameter of the diaphragm 21 is 2.4 mm.

FIG. 8A is a comparative example in which only the throttle 21 is provided and the gas flow noise suppressing member 234 is not provided. FIG. 8B is a comparative example in which the gas flow noise is located 1.5 mm away from the exit surface of the throttle 21. It is a 1st embodiment in which suppression member 234 was arranged. First
In the embodiment, the noise of the diaphragm 21 is reduced by 68 with respect to the comparative example.
It was found that the noise from the evaporator 17 disposed in the vehicle cabin could be reduced from 49.5 dB to 464.5 dB.

FIG. 8C shows a modification of the gas flow noise suppressing member 234 of the first embodiment, in which the gas flow noise suppressing member 234 is made of a porous metal. As the porous metal, a nickel-chromium (Ni-Cr) alloy having a porosity of 96% was used. Since the gas flow noise suppressing member 234 is made of a porous metal through which a refrigerant can pass, it is disposed in close contact with the outlet surface of the throttle 21.

According to the gas flow noise suppressing member 234 of FIG. 8C, it was found that the noise of the throttle 21 can be further reduced to 43 dB. The gas flow noise suppressing member 234 of FIG. 8C may be disposed at a predetermined distance (for example, about 1.5 mm) away from the exit surface of the throttle 21 similarly to that of FIG. It has been confirmed that the noise reduction effect can be exhibited.

(Second Embodiment) FIGS. 9 and 10 show a second embodiment. The difference from the first embodiment is that the first and second solenoid valves 12 and 20 are integrated as one valve device 40. And the throttle 21 of the hot gas bypass passage 19
Formed over two stages: a throttle hole 223 (first-stage throttle means) serving as a valve port of the second solenoid valve 20 and a thin tube 19a '(second-stage throttle means) arranged downstream of the throttle hole 223. That is the point. The thin tube 19a 'is a metal pipe (capillary tube) constituting the hot gas bypass passage 19.

As shown in FIG. 10, the valve device 40 has a valve housing 41 which integrally forms the passages of both the first solenoid valve 12 for cooling and the second solenoid valve 20 for heating. Therefore, the valve housing 41 integrates a portion corresponding to the valve housing 220 in FIG. In the heating second solenoid valve 20, the same parts as those in FIG.

An inlet joint 221 connected to the discharge-side rubber hose 25 of the compressor 10 is always in communication with an inlet chamber 43 of the second solenoid valve 20 for heating through a communication passage 42 in the valve housing 41. . The outlet passage 44 of the second solenoid valve 20 for heating is connected at right angles to the passage of the outlet joint part 222, and the throttle hole (valve port) 223 provided in the outlet passage 44 is closed by the main valve body 224. It opens and closes.

The first solenoid valve 12 for cooling is also provided by the second solenoid valve 12 for heating.
An outlet joint 1 connected to the inlet of the condenser 13 has a pilot valve structure similar to the solenoid valve 20.
A valve port 121 communicating with 20 is provided in the valve housing 41, and the valve port 121 is opened and closed by a main valve body 122. A control hole 123 provided at the center of the main valve body 122 is opened and closed by a pilot valve portion 125 at the tip of a plunger 124.

When the plunger 124 moves upward in FIG. 10 and the valve portion 125 opens the control hole 123, the main valve 1
22 communicates with the passage on the outlet joint section 120 side through the control hole 123, and the pressure in the back pressure chamber 126 decreases. As a result, a pressure difference is generated between the pressure on the inlet joint portion 221 side and the back pressure chamber 126, and this pressure difference acts on the diaphragm 127 as a pressing force upward in FIG. This pressing force causes the main valve body 122 to move as shown in FIG.
, The valve port 121 is opened, and the first solenoid valve 12 is opened.

Next, the electromagnetic mechanism for sucking the plunger 124 upward in FIG. 10 is the same as the second electromagnetic valve 20 for heating, and the plunger 124 is a movable member made of a magnetic material. The fixed core member 12 faces the plunger 124.
8, a coil spring 129 is disposed between the two. Further, the electromagnetic coil 13
0 and the yoke member 131 are arranged, and the electromagnetic coil 13
The magnetic flux flows through the magnetic circuit including the yoke member 131, the plunger 124, and the fixed core member 128 when the current is supplied to 0, and an attractive force is generated between the plunger 124 and the fixed core member 128, and the plunger 124 is moved by the spring 129. 10 is displaced upward in FIG. On the other hand, when the power supply to the electromagnetic coil 130 is cut off, the electromagnetic attraction force disappears, and the plunger 124 is moved by the force of the spring 129 in FIG.
Therefore, the pilot valve 125 closes the control hole 123. The back pressure chamber 126 passes through a small communication hole 132 formed in the main valve
The pressure in the back pressure chamber 126 is the same as the pressure in the inlet joint 221 because it is always in communication with the passage on the first side.
Since the differential pressure disappears, the main valve body 122 is displaced downward in FIG. 10 by the force of the spring 129, and closes the valve port 121. That is, the first solenoid valve 12 is closed.

Incidentally, a metal thin tube (capillary tube) constituting the hot gas bypass passage 19 shown in FIG. 9 is provided at the outlet joint portion 222 of the second solenoid valve 20 for heating.
19a 'is connected. Therefore, in the second embodiment, the throttle 21 of the hot gas bypass passage 19 is formed by the throttle hole 223 serving as the valve port of the second solenoid valve 20 and the narrow tube 19 a ′ disposed downstream of the throttle hole 223. It is formed over the steps. Also on the outer peripheral surface of this thin tube 19a ',
It is preferable to mount the heat insulating material 19b in FIG. 2B for heat insulation.

Next, a specific example of the two-stage structure of the stop 21 will be described. The diameter of the stop hole 223 is set to 3 mm, and the narrow tube 19a 'is formed.
Outside diameter: 6 mm: inside diameter: 4 mm
The length of a 'is 1500 mm. The exit passage 44
The diameter of the outlet joint 222 is also 3 mm, which is the same as the diameter of the throttle hole 223. Further, the pipe diameters of other parts of the refrigeration cycle are the same as those of the first embodiment.

By setting the diameter of the throttle hole 223 and the diameter and length of the thin tube 19a 'as described above, the throttle hole 2
23 is about 50% in the first stage, and the narrow tube 1
The aperture ratio of the second stage by 9a 'is about 50%.
Next, the features of the second embodiment will be described. Since the hot gas which has been decompressed in the throttle hole 223 at the inlet of the hot gas bypass passage 19 and whose temperature has dropped flows through the thin tube 19a ', the second embodiment is different from the first embodiment. The amount of the first-stage throttle by the throttle hole 223 decreases, and the refrigerant temperature after the decompression increases. However, even after the temperature decreases to an intermediate temperature between 70 ° C. and 40 ° C. in the first embodiment, Since the refrigerant flows, the narrow tube 19
The temperature difference between the refrigerant in a 'and the ambient atmosphere temperature is reduced.

Furthermore, in the case of the first embodiment, since the throttle 21 is a one-stage throttle, it is necessary to increase the diameter of the pipe 19a downstream of the throttle 21 device in order to cope with an increase in the specific volume of the refrigerant after the pressure reduction. However, according to the second embodiment, the aperture 21
Is a two-stage aperture, and a second-stage aperture composed of a thin tube 19a 'is formed downstream of the aperture hole 223 of the first-stage aperture.
The use of the small tube 19a 'can reduce the pipe surface area and increase the flow rate of the refrigerant, so that the heat loss of the refrigerant flowing through the small tube 19a' can be reduced more effectively than in the first embodiment.

Further, since the second-stage throttle means is constituted by the thin tube 19a ', the piping space for the thin tube 19a' can be reduced, and the piping can be easily arranged in a narrow space such as a vehicle. In the second embodiment, the thin tube 19a '
Is located in the vehicle cabin or in the vicinity of the vehicle cabin, so the flow noise caused by the gas jet (jet core) at the outlet of the narrow tube 19a 'poses a problem. Therefore, although not shown in FIG. 9, it is preferable to arrange the gas flow noise suppressing member 234 of the first embodiment at the outlet of the thin tube 19a 'to reduce the flow noise.

(Third Embodiment) In the first embodiment described above, the gas flow noise suppressing member 234 is opposed to the outlet of the throttle 21 within the range of the gas jet flow A, and the member 234 is provided.
The gas jet stream A is caused to collide with the tip surface of the gas stream to reduce the gas flow noise by narrowing the range in which the gas jet stream A forms the mixing area B. In the third embodiment, such a gas flow noise is generated. It is intended to reduce the refrigerant flow noise without using the suppressing member 234.

That is, the rapid expansion portion of the passage at the outlet of the throttle 21 and the pipe 19 of the hot gas bypass passage 19
At the abruptly expanding portion of the passage at the outlet a, the refrigerant pressure sharply decreases, and accordingly, the flow velocity of the gas refrigerant becomes sonic, which causes the refrigerant flow noise to increase during the hot gas bypass operation. Therefore, in the third embodiment, by paying attention to the above phenomenon, a sudden decrease in the refrigerant pressure is suppressed by forming a tapered passage portion that gradually enlarges the passage cross-sectional area at the portion of the passage suddenly enlarged portion. In addition, the flow velocity of the gas refrigerant is suppressed to a value lower than the sonic velocity to reduce the flow noise of the refrigerant.

First, referring to FIG. 11, a specific combination of the heating throttle 21 and the hot gas bypass passage 19 is described.
The relationship with the noise of the evaporator 17 will be described with reference to FIG.
In the table of (a), the following four types are shown as combinations of the throttle 21 and the hot gas bypass path 19. The length L of the hot gas bypass path 19
= 1 m, the inner diameter of the hot gas bypass passage 19 is gradually tapered from φ2.4 mm to φ10.1 mm. The inlet side pipe of the evaporator 17 has an outer diameter D = Ｄ inch.

With respect to the four types of hot gas bypass passage configurations, changes in the refrigerant pressure during the hot gas bypass operation were measured, and the results were as shown in the graph of FIG. Here, the operating conditions are as follows: outside temperature = −10 ° C., rotation speed of the compressor 10 = 1500 rpm, speed (air volume) of an air-conditioning blower that blows air (outside air) to the evaporator 17: Lo
It is.

As shown in the graph of FIG. 11A, a portion E of the throttle 21 located at the entrance of the hot gas bypass passage 19 and a junction F of the outlet of the hot gas bypass passage 19.
It can be seen that the refrigerant pressure greatly changes (decreases) at the two locations. As a result, when the refrigerant flow noise during the hot gas bypass operation was measured in the evaporator 17 part, the result shown in FIG. 11B was obtained. That is, since the outlet junction F of the hot gas bypass path 19 is located close to the evaporator 17, the noise of the evaporator 17 is the largest in the combination where the change in the refrigerant pressure at the outlet junction F is large. Then, the noise of the evaporator 17 increases in the combination of the large change in the refrigerant pressure at the throttle 21 at the inlet.

On the other hand, in the combination (1), the diameter of the throttle 21 is increased to φ2.4 mm and the pipe of the hot gas bypass path 19 is reduced in diameter (φ10.1 m).
m to φ6 mm), the pressure change immediately after the throttle 21 can be reduced and the noise of the evaporator 17 can be reduced. And, in the combination, the hot gas bypass path 1
9, at both the inlet converging portion and the outlet merging portion, a tapered passage portion for gradually increasing the passage cross-sectional area is formed. Therefore, the portion immediately after the constriction 21 and the outlet of the hot gas bypass passage 19 are formed. The pressure change can be mitigated at both of the converging portions, and as a result,
The noise of the part can be reduced most.

The third embodiment is based on the experimental results shown in FIG. 11. First, the specific structure of the thermal expansion valve 15 of the third embodiment will be described with reference to FIG. Has a gas refrigerant flow path 153 through which the gas refrigerant evaporated in the evaporator 17 flows. The diaphragm 154 detects the pressure and temperature of the refrigerant in the flow path 153. Is displaced, and the spherical valve element 157 is displaced via the temperature sensing rod 155 and the operating rod 156 by the displacement of the diaphragm 154.

The valve 157 is connected to the high-pressure flow path 15.
The flow rate of the refrigerant is adjusted by adjusting the opening of the throttle channel 160 formed between the low pressure channel 8 and the low pressure channel 159. These elements 15
Reference numerals 3 to 160 are provided in a vertically long rectangular parallelepiped housing 161. The first joint 151 is connected to the main block 1 connected to the housing 161 of the expansion valve body 150.
62 and a sub-block 163 connected to the main block 162. In the main block body 162,
A low-pressure channel 164 connected to the low-pressure channel 159 is provided, and the check valve 16 is built in the low-pressure channel 164.

The check valve 16 is formed of a material such as resin into a substantially cylindrical shape, and has an O-ring (elastic sealing material) on its outer peripheral surface.
16a is arranged and held. When a reverse pressure is applied to the check valve 16 from the outlet side (the right side in FIG. 12) of the check valve 16, the O-ring 16 a is pressed against the seat surface of the low-pressure channel 164, and the check valve 16 is closed. It becomes a valve state. On the other hand, when a forward pressure is applied from the inlet side of the check valve 16 (the left side in FIG. 12), the O-ring 16 a
The check valve 16 is opened by separating from the seat surface. FIG. 12 shows a closed state of the check valve 16. Further, the check valve 16 is integrally formed with a locking claw portion 16b for regulating the valve opening lift amount to a predetermined value.

Further, the low pressure passage 1 of the main block body 162
At 64, a bypass connection passage 165 is connected to a portion on the outlet side of the check valve 16. This bypass connection passage 16
5 extends in the direction perpendicular to the paper surface of FIG.
3 is provided in a bypass joint 171 shown in FIG.
The bypass joint 171 is fastened and fixed to the main block body 162 by bolts 172, and the bypass connection passage 165 is provided to penetrate the wall surface of the bypass joint 171 in the thickness direction (the left-right direction in FIG. 13). Then, one end of the bypass connection passage 165 (FIG. 1)
3 at the right end of the hot gas bypass passage 19
The outlet portion 9a is joined by brazing or the like.

[0074] Then, the shape of the bypass connection passage 165, toward the outlet portion of the pipe 19a of the hot-gas bypass passage 19 to the low-pressure line 164, and gradually tapers to increase the cross-sectional area with a predetermined taper angle theta _r It is in shape. The other end of the bypass connection passage 165 after being expanded in a tapered shape communicates with the low-pressure passage 164. On the other hand, the main block body 162 is provided with a gas refrigerant flow path 166 extending in parallel with the low pressure flow path 164, and this gas refrigerant flow path 166 is connected to the gas refrigerant flow path 153 of the expansion valve main body 150. The sub-block body 163 is provided with two connection ports 167 and 168, and one of the connection ports 167 has a gas-liquid two-phase refrigerant and hot gas bypass depressurized in the throttle passage 160 of the expansion valve main body 150. Both hot gases from the passage 19 flow in. This connection port 167 is connected to the inlet pipe of the evaporator 17, and the other connection port 168 is connected to the outlet pipe of the evaporator 17.

The second joint 152 is connected to the housing 161 of the expansion valve main body 150 on the side opposite to the main block body 162 of the first joint 151, and has two connection ports 169, 170. One connection port 169 is connected to the outlet side of the liquid receiver 14, and the other connection port 170 is connected to the inlet side of the accumulator 18.

Therefore, the gas refrigerant evaporated in the evaporator 17 is connected to the connection port 168 → the gas refrigerant flow path 166 in FIG.
→ flows into the gas refrigerant channel 153 → the connection port 170, and further flows toward the inlet of the accumulator 18. FIG.
In order to prevent a rapid expansion of the hot gas bypass passage 19 at the exit junction, the bypass connection passage 165 will be described.
Although formed in a tapered passage portion, as schematically shown in FIG. 14, also immediately after the stop 21 located at the inlet portion of the hot gas pi pass passage 19 gradually passage with a predetermined taper angle theta _f Tapered passage 5 whose cross-sectional area gradually increases
0.

FIG. 15 shows the taper angle θ _f of the tapered passage portion (first tapered passage portion) 50 immediately after the throttle 21 and the bypass connection passage (second tapered passage portion) at the outlet side of the hot gas bypass passage 19. Passage) 165 taper angle θ
15 is an experimental result showing the relationship between _r and the evaporator section noise. The horizontal axis in FIG. 15 indicates the taper angle θ _r of the bypass connection passage 165.

The taper angle θ _r of the outlet side bypass connection passage 165 is set within a range of 15 ° or less (θ _r <15 °),
And the taper angle θ of the tapered passage portion 50 immediately after the throttle 21.
_{When f} was set within 12 ° (θ _f <12 °), it was confirmed that the evaporator section noise could be reduced to approximately 46 dB or less. This is because the tapered passage shape can suppress a rapid drop in the refrigerant pressure and prevent the refrigerant flow velocity from becoming sonic.
In particular, the taper angle θ of the tapered passage portion 50 immediately after the throttle 21
_{When f} = 3 °, the bypass connection passage 16 on the outlet side
Five of the taper angle theta _r increases up to 15 °, it is possible to suppress the evaporator section noise to 45dB constant is advantageous.

As described above, according to the third embodiment, even if the gas flow noise suppressing member 234 of the first embodiment is not used, the evaporator section can reach the same level as that of FIGS. 8B and 8C. The noise can be reduced. In FIG. 15,
θ _f , θ _r = 180 ° means that there is no tapered shape, in other words, the passage cross-sectional shape is a shape that suddenly expands at right angles. In this case, the portion immediately after the throttle 21 and the bypass passage 19 bypass connection passage 165 on the exit side
Of these, the passage abruptly enlarged portion is formed in one of them, so that the noise of the evaporator portion rises considerably.

FIG. 14 schematically shows the tapered passage 50 immediately after the throttle 21.
Is a valve housing 220 of the heating solenoid valve 20 shown in FIG.
At the passage portion of the outlet joint portion 222. Similarly, the valve housing 41 of the valve device 40 of FIG.
In, the tapered passage portion 50 can be formed in the outlet passage 44 of the heating electromagnetic valve 20 and the passage portion of the outlet joint portion 222.

Further, between the outlet joint 222 of the valve housing 220 (or the valve housing 41) and the inlet of the pipe 19a of the hot gas bypass passage 19,
Joint (not shown) forming tapered passage section 50
May be interposed. (Fourth Embodiment) FIGS. 16 to 18 show a fourth embodiment. In the second embodiment, as shown in FIG.
Although the second solenoid valves 12 and 20 are integrated as one valve device 40, in the fourth embodiment, the refrigerant flow switching function of the first and second solenoid valves 12 and 20 (the condenser 13 and the hot By achieving the function of switching the flow of the refrigerant to the gas bypass passage 19 side by one three-way switching valve 400, the size and cost of the valve means can be further reduced.

FIG. 18 shows a comparison between the valve operation of the first and second solenoid valves 12 and 20 shown in FIG. 10 and the valve operation of the three-way switching valve 400 shown in FIGS. According to 400, it can be seen that both the condenser 13 side and the hot gas bypass passage 19 side cannot be opened or both closed. However, according to the experimental studies of the present inventors, in the refrigeration cycle apparatus that sets the heating mode by the hot gas bypass, it is not necessary to close both of them as described above. The mode is required only when the volume of the accumulator 18 is small (for example, 300 cc or less). When the volume of the accumulator 18 is large, the three-way switching valve 40 shown in FIGS.
0 is possible.

The reason is that when the volume of the accumulator is small, the inside of the accumulator 18 may be filled with the liquid refrigerant and the liquid refrigerant may overflow from the accumulator 18.
In this state, the gas-liquid separation function of the accumulator 18 is lost. Therefore, it is necessary to open both the condenser 13 side and the hot gas bypass passage 19 side to release a part of the surplus refrigerant to the condenser 13 side. However, when the volume of the accumulator is sufficiently large, the phenomenon that the liquid refrigerant overflows from the accumulator 18 does not occur. Therefore, the refrigerant amount adjustment mode for discharging the excess refrigerant to the condenser 13 side (that is, the condenser 13 side and the hot gas It is not necessary to execute both of the bypass passages 19). Therefore, the three-way switching valve 400 shown in FIGS.

Next, the specific structure and operation of the three-way switching valve 400 will be described with reference to FIGS. The three-way switching valve 400 has a valve housing 410, and the inlet joint portion 4 into which the gas refrigerant discharged from the compressor 10 flows.
11 and an outlet joint 412 connected to the inlet side of the condenser 13 are linearly opposed to the valve housing 410. Also, the two joint portions 411, 412
Hot gas bypass passage 19 in a direction orthogonal to the axis connecting
The outlet joint part 413 connected to the inlet side of is provided.

In the valve housing 410, first and second main valve bodies 414 and 415 and a pilot valve body 416 are disposed so as to be vertically displaceable in FIG. The first main valve element 414 opens and closes a valve port 417 connecting the inlet joint 411 and the condenser-side outlet joint 412. Further, the second main valve element 415 is connected to the inlet joint section 4.
The throttle hole 418 connecting the bypass joint 11 with the bypass side outlet joint 413 is opened and closed. The throttle hole 418 forms the throttle 21 of the hot gas bypass passage 19.

The first main valve element 414 and the second main valve element 415 are integrally connected by a plurality of connecting rods (connecting means) 428 so as to be integrally displaced. FIG. 16 shows only one connecting rod 428.
A back pressure chamber 419 is formed at a portion opposite to the valve port 417 with respect to the first main valve body 414, and a spring 420 for closing the first main valve body 414 is disposed in the back pressure chamber 419. Have been. The back pressure chamber 419 communicates with the downstream side of the first main valve body 414 (that is, the passage of the condenser-side outlet joint 412) via the control hole 421 and the connection passage 422. Further, the inside of the back pressure chamber 419 is always in communication with the upstream side of the first main valve body 414 (that is, the passage of the inlet joint 411) via a minute communication passage (not shown).

The pilot valve element 416 is connected to the control hole 421.
And is driven by an electromagnetic mechanism having a plunger 423 (corresponding to the plungers 124 and 266 in FIG. 10). The upper end of the shaft of pilot valve element 416 is integrally connected to the lower end of plunger 423. The electromagnetic mechanism for sucking the plunger 423 upward in FIG. 16 is the same as that in FIG.
The fixed core member 424 is disposed opposite to the
A coil spring 425 is arranged between 23 and 424. Further, an electromagnetic coil 426 and a yoke member 427 are arranged.

When the electromagnetic coil 426 is not energized, the plunger 423 is displaced downward in FIG. 16 by the force of the spring 425.
21 is opened. Then, the back pressure chamber 4 of the first main valve body 414
19 communicates with the passage on the outlet joint 412 side via the control hole 421 and the connection passage 422, and the pressure in the back pressure chamber 419 decreases.

As a result, a pressure difference is generated between the pressure on the inlet joint portion 411 side and the back pressure chamber 419, and this pressure difference is applied to the first main valve element 414 as a pressing force upward in FIG. Works. Due to this pressing force, the first and second main valve bodies 41
4 and 415 are displaced upward in FIG.
4, the valve port 417 is opened, and at the same time, the throttle hole 418 is closed by the second main valve body 415. That is, when the electromagnetic coil 426 is not energized, the inlet joint 411 communicates with the condenser-side outlet joint 412, and the cooling mode is set.

On the other hand, when the electromagnetic coil 426 is energized, the yoke member 427, the plunger 423, and the fixed core member 4
The magnetic flux flows through the magnetic circuit consisting of the plunger 42.
A suction force is generated between 3 and the fixed core member 424, and the plunger 423 is displaced upward in FIG. 16 against the spring force of the spring 425, and the pilot valve body 416 is also displaced upward.

As a result, since the control hole 421 is closed by the pilot valve element 416, the communication between the back pressure chamber 419 of the first main valve element 414 and the outlet joint 412 on the condenser side is cut off. Here, since the inside of the back pressure chamber 419 is always in communication with the passage of the inlet joint 411 via the minute communication passage (not shown), the pressure in the back pressure chamber 419 rises to the pressure of the inlet joint 411.

As a result, the pressures acting on the upper and lower sides of the first main valve body 414 become the same, so that the first main valve body 414 presses against the valve seat surface of the valve port 417 by the spring force of the spring 420.
The valve port 417 is closed. At the same time, the second main valve body 41
5 is separated from the valve seat surface of the throttle hole 418 to open the throttle hole 418. That is, when the electromagnetic coil 426 is energized, the inlet joint 411 is connected to the bypass-side outlet joint 4.
13 and the heating mode is set.

(Other Embodiments) In order to reduce the refrigerant flow noise during the hot gas bypass operation, a heating throttle (pressure reducing device) 21 located at the inlet side of the bypass passage is used.
The gas flow noise suppressing member 234 of the first embodiment is adopted in a portion immediately after the above, while the bypass connection passage 165 on the outlet side of the bypass passage 19 is formed by the tapered passage portion according to the third embodiment, The flow noise suppressing member and the tapered passage may be combined.

In the above-described embodiment, the case where the present invention is applied to a refrigeration cycle of a vehicle air conditioner has been described. However, it goes without saying that the present invention can be applied to refrigeration cycles for various uses. Further, in the fourth embodiment, the three-way switching valve 400 has a structure in which the first and second main valve bodies 414 and 415 arranged at positions separated from each other are integrally connected. The first and second main valve bodies 414 and 415 are integrally formed by changing the positional relationship between the inlet joint 411, the outlet joint 412 on the condenser side, and the outlet joint 413 on the hot gas bypass passage. An integrated three-way switching valve 400 can also be used.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram showing a first embodiment of the present invention.

FIG. 2A is an exploded perspective view showing a mounted state of the first embodiment on a vehicle, and FIG. 2B is a cross-sectional view of a piping portion of a hot gas bypass passage.

FIG. 3 is a sectional view of the valve device of FIG. 1;

FIG. 4 is a Mollier diagram for describing effects of the first embodiment.

FIG. 5 is a graph for explaining effects of the first embodiment.

FIG. 6 is a diagram illustrating a cause of noise generation in a throttle portion of a hot gas bypass passage in the first embodiment.

FIG. 7 is an explanatory diagram of an effect of the gas flow noise suppressing member according to the first embodiment.

FIG. 8 is an explanatory diagram of an experimental result of the gas flow noise suppressing member according to the first embodiment.

FIG. 9 is a schematic perspective view showing a state in which the second embodiment is mounted on a vehicle.

FIG. 10 is a sectional view of a valve device according to a second embodiment.

FIG. 11 explains the premise of the third embodiment,
(A) is an explanatory view of the relationship between the configuration of the hot gas bypass passage and the refrigerant pressure, and (b) is a graph of an experimental result showing the relationship between the configuration of the hot gas bypass passage and the noise of the evaporator section.

FIG. 12 is a sectional view of a thermal expansion valve according to a third embodiment.

FIG. 13 is a sectional view taken along line GG of FIG.

FIG. 14 is a schematic explanatory view of a configuration of a hot gas bypass passage according to a third embodiment.

FIG. 15 is a graph showing a noise reduction effect of the evaporator according to the third embodiment.

FIG. 16 is a sectional view of a three-way switching valve according to a fourth embodiment.

FIG. 17 is a front view of a three-way switching valve according to a fourth embodiment.

FIG. 18 is a chart comparing the operation of the three-way switching valve of the fourth embodiment and the operation of the valve device of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Compressor, 12, 20 ... First and 2nd solenoid valve (valve means), 13 ... Condenser, 15 ... Temperature expansion valve (1st pressure reducing device), 16 ... Check valve, 17 ... Evaporator, 19 ... Hot gas bypass passage, 19a ... Piping, 19a '... Narrow tube, 21 ...
Throttles (second pressure reducing devices), 50, 165: tapered passage portions, 223: throttle holes, 234: gas flow noise suppressing members.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hajime Ito 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. Inside

Claims (13)

[Claims] A compressor for compressing and discharging a refrigerant (10)
A condenser (13) for condensing the refrigerant gas discharged from the compressor (10); a first decompression device (15) for decompressing the refrigerant condensed in the condenser (13); An evaporator (17) for evaporating the refrigerant decompressed in (15), and a discharge side of the compressor (10) directly connected to the evaporator (1).
7) The hot gas bypass passage (1) connected to the inlet side
9), a second pressure reducing device (21) provided in the hot gas bypass passage (19) for reducing the pressure of the gas refrigerant discharged from the compressor (10), and the condensation from the discharge side of the compressor (10). (13) and valve means (12, 20, 400) for switching the refrigerant flow to the hot gas bypass passage (19), and the discharge gas refrigerant of the compressor (10) is supplied to the hot gas bypass passage (19). ) Directly through the evaporator (17)
A refrigeration cycle device that sets a heating mode by hot gas bypass by flowing the gas into the refrigeration cycle, wherein the second pressure reducing device (21) is disposed upstream of the hot gas bypass passage (19). apparatus. 2. The valve means (12, 20, 400) is disposed upstream of the hot gas bypass passage (19), and the second pressure reducing device (21) is provided in the valve means (12, 20, 400). 2. The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus further comprises: 3. The refrigeration cycle apparatus according to claim 1, wherein the second pressure reducing device is disposed at an inlet of the hot gas bypass passage. 4. An outlet of the second pressure reducing device (21),
4. A gas flow noise suppressing member (234) arranged to reduce the range of formation of a gas jet by collision of gas jets jetted from said second pressure reducing device (21). The refrigeration cycle apparatus according to any one of the above. 5. An outlet of the second pressure reducing device (21),
The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein a tapered passage portion (50) that gradually enlarges a passage cross-sectional area is formed. 6. The hot gas bypass passage (19) further comprising a tapered passage portion (165) formed at an outlet junction of the hot gas bypass passage (19) so as to gradually increase a sectional area of the passage. A refrigeration cycle apparatus according to one of the preceding claims. 7. An outlet of the second pressure reducing device (21),
The first tapered passage portion (5) gradually increasing the passage cross-sectional area
0), and at the outlet junction of the hot gas bypass passage (19),
The second tapered passage portion (1) gradually increasing the passage cross-sectional area
65), and the taper angle (θ _f ) of the first tapered passage portion (50).
Is within 12 °, and the second tapered passage portion (16
5) taper angle (theta _r) is a refrigeration cycle apparatus according to any one of claims 1 to 3, characterized in that within 15 ° of. 8. A compressor for compressing and discharging a refrigerant.
A condenser (13) for condensing the refrigerant gas discharged from the compressor (10); a first decompression device (15) for decompressing the refrigerant condensed in the condenser (13); An evaporator (17) for evaporating the refrigerant decompressed in (15), and a discharge side of the compressor (10) directly connected to the evaporator (1).
7) The hot gas bypass passage (1) connected to the inlet side
9), a second pressure reducing device (21) provided in the hot gas bypass passage (19) for reducing the pressure of the gas refrigerant discharged from the compressor (10), and the condensation from the discharge side of the compressor (10). (13) and valve means (12, 20, 400) for switching a refrigerant flow to the hot gas bypass passage (19).
The gas refrigerant discharged from the compressor (10) is passed directly through the hot gas bypass passage (19) to the evaporator (1).
7) a refrigeration cycle apparatus that sets a heating mode by hot gas bypass by flowing into a hot gas bypass, wherein a first-stage throttle means comprising a throttle hole (223) arranged upstream of the hot gas bypass passage (19); The second pressure reducing device (2) by means of a second-stage restricting means comprising a thin tube (19a ') arranged downstream of the first-stage restricting section.
A refrigeration cycle apparatus characterized by the above (1). 9. The valve means (12, 20, 400) is disposed upstream of the hot gas bypass passage (19), and the throttle hole (223) is provided in the valve means (12, 20, 400). The refrigeration cycle apparatus according to claim 7, wherein the refrigeration cycle apparatus is incorporated. Entrance 10. The refrigeration cycle apparatus according to claim 8, wherein the throttle hole (223) is arranged at an inlet of the hot gas bypass passage (19). 11. The valve means comprises a three-way switching valve (400).
2. The method according to claim 1, wherein
0. The refrigeration cycle apparatus according to any one of 0. 12. A vehicle air conditioner using the refrigeration cycle device according to claim 1, wherein the air conditioner unit (2) includes the evaporator (17).
An air conditioner for a vehicle, wherein 3) is disposed in a vehicle compartment, and the second pressure reducing device (21) is disposed in an engine room. 13. The compressor (10) is arranged in the engine room and driven by a vehicle engine, and the hot gas bypass passage (19) is located at a position near the vehicle engine and receiving heat from the vehicle engine. The vehicle air conditioner according to claim 12, wherein the air conditioner is disposed.