JP2008292109A - Variable capacity liquid receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable capacity liquid receiver capable of securing control stability of capacity change while having a simple structure. <P>SOLUTION: The variable capacity liquid receiver 3 for making a gas-liquid-mixed high pressure refrigerant from a main condenser 2 in a refrigerant circulation path of a refrigerating cycle to flow into a tank main body 31 and separating the gas and liquid, is equipped with: divided chambers A, B formed by dividing the inner volume of the tank main body 31 into a plurality; a check valve 33 installed at a communicating position of the adjacent divided chambers in the plurality of divided chambers A, B, allowing only the refrigerant flow in the refrigerant circulating direction, and inhibiting the refrigerant flow in the reverse direction from the refrigerant circulating direction; a plurality of refrigerant inflow paths 37, 38 branched from a refrigerant inflow path 36 of the main condenser 2 and provided communicated with the plurality of the divided chambers A, B, respectively; and a refrigerant inflow path switching means for switchably selecting the plurality of refrigerant inflow paths 37, 38. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable capacity liquid receiver having a condenser in a refrigerant circulation path of a refrigeration cycle, and gas-liquid separation by flowing a high-pressure refrigerant mixed with gas from the condenser into a tank body.

  In an automotive air conditioner equipped with a refrigeration cycle comprising a compressor, a condenser, a liquid receiver, an expander (expansion valve), and an evaporator, the liquid receiver receives heat from the engine room and overheats. As a result, the degree of refrigerant supercooling at the outlet of the liquid receiver decreases, and bubbles are generated in the sight glass. As a result, the refrigerant is misrecognized as insufficient and the refrigerant is overfilled.

  To solve this problem, a variable capacity body (such as a bellows or a resin chamber) is installed inside the liquid receiver to reduce the internal volume of the liquid receiver and to ensure the degree of refrigerant supercooling. It has been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

Here, the “degree of refrigerant supercooling” means the high-pressure refrigerant saturation temperature (temperature corresponding to the condensation pressure of the refrigerant liquid condensed in the condenser) and the supercooled refrigerant temperature (the refrigerant liquid exiting the condenser was cooled). This is a refrigerant state index expressed by the difference in temperature. “Refrigerant supercooling degree decreases” means that the difference between both temperatures becomes small, and “ensures refrigerant supercooling degree” means that both temperature differences are kept at a predetermined temperature or higher.
Japanese Utility Model Publication No.59-195473 JP-A 63-279069 Japanese Patent No. 2550632

  However, the conventional variable capacity liquid receiver adopts a structure in which a variable capacity body (such as a bellows or a resin chamber) is installed inside the liquid receiver as a structure that makes the internal volume of the liquid receiver variable. Therefore, there is a problem that the structure of the liquid receiver is complicated. In addition, since the variable capacity body inside the liquid receiver is always in an environment where the refrigerant pressure is received, a desired capacity change is performed depending on the environmental conditions due to the influence of the refrigerant pressure acting on the variable capacity body when the capacity is changed. There is a problem that the control stability of the capacity change cannot be ensured, for example, there is no case.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a variable capacity liquid receiver capable of ensuring control stability of capacity change while having a simple structure.

In order to achieve the above object, according to the present invention, a variable capacity that has a condenser in the refrigerant circulation path of the refrigeration cycle and separates the high-pressure refrigerant mixed with gas and liquid from the condenser into the tank body for gas-liquid separation. In the receiver,
A division chamber formed by dividing the internal volume of the tank body into a plurality of; and
A check valve that is installed at a communication position between adjacent division chambers among the plurality of division chambers, permits only refrigerant flow in the refrigerant circulation direction, and prevents refrigerant flow in the direction opposite to the refrigerant circulation direction;
A plurality of refrigerant inflow paths branched from the refrigerant inflow path from the condenser and provided in communication with each of the plurality of divided chambers;
Refrigerant inflow path switching means for switching and selecting the plurality of refrigerant inflow paths;
It is provided with.

Therefore, in the variable capacity liquid receiver of the present invention, by the switching selection action of the plurality of refrigerant inflow paths by the refrigerant inflow path switching means and the action of regulating the direction of the refrigerant flow by the check valve in one direction, for example, A high volume state in which the volumes of all the divided chambers are combined, a medium volume state in which the volumes of some of the divided chambers are combined, and a low volume state due to the volume of one divided chamber can be obtained.
That is, the internal volume of the tank body is divided into a plurality of parts and a check valve is required. Therefore, the structure is simple compared to a structure in which a variable capacity body such as a bellows or a resin chamber is installed inside the liquid receiver. It becomes.
In addition, during the capacity change control, the refrigerant inflow path switching means provided outside the tank of the liquid receiver is a control target, and the capacity change control is performed by selecting a plurality of refrigerant inflow paths. For this reason, the capacity change control is stable without being affected by changes in the internal environment of the liquid receiver, such as changes in refrigerant pressure, as in the case of controlling a variable capacity body installed inside the tank of the liquid receiver. Can be done.
As a result, it is possible to ensure the control stability of the capacity change with a simple structure.

  Hereinafter, the best mode for realizing the variable capacity liquid receiver of the present invention will be described based on Examples 1 to 3 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a refrigeration cycle of an automotive air conditioner to which the variable capacity liquid receiver of Example 1 is applied.

  As shown in FIG. 1, the refrigeration cycle of the automotive cooling device to which the variable capacity liquid receiver of Example 1 is applied includes a compressor 1, a main condenser 2 (condenser), a variable capacity liquid receiver 3, and the like. , Subcool condenser 4 (supercooled condenser), expander 5 (expansion valve), evaporator 6 (evaporator), first electromagnetic valve 7 (refrigerant inflow path switching means), and second electromagnetic valve 8 (refrigerant). Inflow path switching means), high-pressure refrigerant saturation temperature sensor 9 (load detection means), supercooled refrigerant temperature sensor 10 (load detection means), outside air temperature sensor 11 (load detection means), high-pressure switch 12, and heat sensitive. A cylinder 14 and a controller 15 (refrigerant inflow path switching means) are provided.

  The compressor 1 compresses the gaseous refrigerant from the evaporator 6 into a high-temperature and high-pressure refrigerant and sends it to the main condenser 2.

  The main condenser 2 liquefies the high-temperature and high-pressure refrigerant discharged from the compressor 1 by radiating heat, and sends the gas-liquid mixed high-pressure refrigerant to the variable capacity receiver 3.

  The variable capacity liquid receiver 3 flows the gas-liquid mixed high-pressure refrigerant from the main condenser 2 into the tank body for gas-liquid separation, removes moisture and dust, and sends it to the subcool condenser 4. This variable capacity liquid receiver 3 has the role of eliminating the stagnation of liquid refrigerant in the main capacitor 2 when the load fluctuates, ensuring a heat radiation area, and suppressing the pressure increase in the high pressure section.

  The subcool condenser 4 further cools the high-pressure liquid refrigerant from the variable capacity receiver 3 and sends it to the expander 5.

  The expander 5 rapidly expands the high-pressure liquid refrigerant from the subcool condenser 4 by reducing the pressure to form a low-temperature / low-pressure mist refrigerant, and sends the low-temperature / low-pressure mist refrigerant to the evaporator 6. In the expander 5, the valve opening degree is adjusted by the refrigerant temperature detected by the thermal cylinder 14 provided on the outlet side of the evaporator 6.

  The evaporator 6 converts the low-temperature and low-pressure mist refrigerant from the expander 5 into a gaseous refrigerant by evaporating (vaporizing) the heat from the surrounding air, and the gaseous refrigerant is supplied to the compressor 1 again. send. The evaporator 6 is built in an air conditioning unit disposed in an instrument panel in an automotive cooling device.

  The high-pressure refrigerant saturation temperature sensor 9 is installed in the main capacitor 2. The supercooling refrigerant temperature sensor 10 is installed at the outlet of the subcool condenser 4. The outside air temperature sensor 11 is disposed at a position where the outside temperature of the passenger compartment can be detected. The high voltage switch 12 is disposed at the outlet of the main capacitor 2.

  The controller 15 inputs signals from the sensors 9, 10, 11 and the high pressure switch 12, and controls the opening / closing operation of the first electromagnetic valve 7 and the second electromagnetic valve 8.

  FIG. 2 is a cross-sectional view showing the variable capacity liquid receiver at the normal outside air temperature of the first embodiment. FIG. 3 is a cross-sectional view showing the variable capacity liquid receiver at the time of low outside air temperature (when the capacity is decreased) according to the first embodiment.

  As shown in FIGS. 2 and 3, the variable capacity liquid receiver 3 of the first embodiment includes a tank body 31, a partition wall 32, a first divided chamber A, a second divided chamber B, and a check valve 33. The dryers 34, 34, the strainer 35, the refrigerant inflow path 36, the first refrigerant inflow path 37, the second refrigerant inflow path 38, and the refrigerant outflow path 39 are provided.

  The first division chamber A and the second division chamber B are chambers formed by dividing the internal volume of the tank body 31 into two chambers via a partition wall 32. For example, in the first embodiment, the internal volume of the first divided chamber A is 175 cc, and the internal volume of the second divided chamber B is 175 cc.

  The check valve 33 is installed at the position of the partition wall 32 that defines the first divided chamber A and the second divided chamber B, permits only the refrigerant flow in the refrigerant circulation direction, and the refrigerant in the direction opposite to the refrigerant circulation direction. Block the flow.

  The dryers 34, 34 are provided at positions in contact with the partition walls 32 of the first division chamber A and the second division chamber B, and a desiccant that removes moisture contained in the refrigerant is incorporated in the container.

  The strainer 35 is disposed at the end position of the refrigerant outflow path 39 inserted into the second divided chamber B, and has a mesh filter that removes foreign matters such as dust contained in the refrigerant.

  The first refrigerant inflow path 37 and the second refrigerant inflow path 38 are branched from the refrigerant inflow path 36 from the main capacitor 2 and are provided in communication with the first divided chamber A and the second divided chamber B, respectively. It is done. A first solenoid valve 7 serving as a refrigerant inflow path switching means for switching between the first refrigerant inflow path 37 and the second refrigerant inflow path 38 is provided at a position midway between the first refrigerant inflow path 37 and the second refrigerant inflow path 38. And a second electromagnetic valve 8 is provided.

  When the solenoid drive command from the controller 15 is a command to open the first solenoid valve 7 and close the second solenoid valve 8, as shown in FIG. The total volume is set to a high volume state. When the solenoid drive command from the controller 15 is a command to close the first solenoid valve 7 and open the second solenoid valve 8, only the volume of the second divided chamber B is shown in FIG. Due to the low volume state.

  FIG. 4A is a flowchart showing the flow of variable capacity control start determination processing executed by the controller 15 of the first embodiment. Each step will be described below.

  In step S1, it is determined whether or not the engine is stopped. If YES (engine stop) is determined, the process proceeds to step S5. If NO (engine operation) is determined, the process proceeds to step S2.

  In step S2, following the engine operation determination in step S1, it is determined whether or not the compressor 1 is stopped. If it is determined Yes (compressor stopped), the process proceeds to step S5. If it is determined No (compressor operation), the process proceeds to step S3.

  In step S3, following the operation determination of the compressor 1 in step S2, it is determined whether or not the high-pressure switch operation count is 1 or more. If it is determined Yes (high voltage switch operation count ≧ 1), the process proceeds to step S5. If it is determined No (high voltage switch operation count = 0), the process proceeds to step S4.

  Step S4 determines whether or not the compressor 1 is a fixed capacity compressor following the determination that the high-pressure switch operation count = 0 in step S3. If Yes (fixed capacity compressor) is determined, the process proceeds to step S5. If No (variable capacity compressor) is determined, the process proceeds to step S6.

  In step S5, following the determination of Yes in at least one of steps S1, 2, 3, and 4, the variable capacity control flag is set to OFF, the first solenoid valve 7 is opened, and the first solenoid valve 7 is opened. (2) A solenoid drive command for closing the solenoid valve 8 is output, and a return is made.

  Step S6 starts variable capacity control of the variable capacity liquid receiver 3 following the determination of No in all steps S1, 2, 3, and 4. That is, the fact that all start avoidance conditions in steps S1, 2, 3, 4 are not satisfied (No determination) is set as a variable capacity control start condition of the variable capacity liquid receiver 3.

  FIG. 4B is a flowchart showing the flow of the high-pressure switch counter process executed by the controller 15 of the first embodiment, and each step will be described below.

  In step S7, it is determined whether or not there is a high-voltage switch operation count clear instruction. When it is determined No (no clear instruction), the process proceeds to step S8, and when it is determined Yes (clear instruction is present), the process proceeds to step S10.

  In step S8, it is determined whether or not the high-voltage switch 12 is in operation, following the determination that the high-voltage switch operation count clear instruction is not issued in step S7. If it is determined Yes (high voltage switch 12 is activated), the process proceeds to step S9. If No (high voltage switch 12 is not activated) is determined, the process proceeds to return.

  In step S9, following the determination that the high pressure switch 12 is activated in step S8, the high pressure switch operation count is set to high voltage switch operation count = 1. When the high-pressure switch operation count has already been set to a value of 1 or more, 1 is added to the count value at that time.

  In step S10, following the determination that there is an instruction to clear the high-pressure switch operation count in step S7, the high-pressure switch operation count is set to 0, and the process proceeds to return. That is, when there is an operation of the high-voltage switch 12 or when there is an operation history of the high-pressure switch 12, the high-pressure switch operation count is set to ≧ 1, thereby determining Yes in step S3 of the flowchart of FIG. As long as there is no clear instruction issued after the safety is confirmed, the variable capacity control of the variable capacity liquid receiver 3 is prohibited and fixed in the large capacity state.

  FIG. 5 is a flowchart showing the flow of the variable capacity control process of the variable capacity receiver 3 executed by the controller 15 of the first embodiment. Each step will be described below.

  In step S51, it is determined whether or not the variable capacity control flag is ON. If it is determined No (variable capacity control flag = OFF), the process proceeds to step S52. If it is determined Yes (variable capacity control flag = ON), the process proceeds to step S55.

  In step S52, following the determination that the variable capacity control flag = OFF in step S51, it is determined whether or not the outside air temperature obtained from the sensor signal from the outside air temperature sensor 11 is less than 5 ° C. (first set temperature). To do. If Yes (outside air temperature <5 ° C.) is determined, the process proceeds to step S53. If No (outside air temperature ≧ 5 ° C.) is determined, the variable capacity control start determination (the process shown in FIG. 4 (a)) is performed. Return.

In step S53, following the determination that the outside air temperature <5 ° C. in step S52, whether or not the state where the refrigerant supercooling degree is less than 3 deg (first set value) has been detected continuously for 10 seconds (set time) or not. Determine whether. If it is determined Yes (refrigerant supercooling degree condition is satisfied), the process proceeds to step S54. If it is determined No (refrigerant supercooling degree condition is not satisfied), variable capacity control start determination (the process shown in FIG. 4A) is performed. Return to).
Here, the refrigerant supercooling degree is calculated by the difference between the high-pressure refrigerant saturation temperature from the high-pressure refrigerant saturation temperature sensor 9 and the supercooling refrigerant temperature from the supercooling refrigerant temperature sensor 10.

  In step S54, following the determination that the refrigerant supercooling degree condition is established in step S53, the variable capacity control flag is set to ON, the first electromagnetic valve 7 is closed, and the second electromagnetic valve is closed. 8 is output, and the variable capacity control start is returned.

  In step S55, following the determination that the variable capacity control flag is ON in step S51, it is determined whether or not the high voltage switch operation count is 1 or more. If it is determined Yes (high pressure switch operation count ≧ 1), the process returns to the variable capacity control start determination (the process shown in FIG. 4A). If it is determined No (high pressure switch operation count = 0), step S56 is performed. Migrate to

  In step S56, following the determination that the high-pressure switch operation count = 0 in step S55, it is determined whether or not the engine is stopped. If it is determined Yes (engine stop), the process returns to the variable capacity control start determination (the process shown in FIG. 4A). If it is determined No (engine operation), the process proceeds to step S57.

  In step S57, following the engine operation determination in step S56, it is determined whether or not the compressor 1 is stopped. When it is determined Yes (compressor stop), the process returns to the variable capacity control start determination (the process shown in FIG. 4A), and when it is determined No (compressor operation), the process proceeds to step S58.

  In step S58, following the determination of the compressor operation in step S57, it is determined whether or not the outside air temperature obtained from the sensor signal from the outside air temperature sensor 11 exceeds 7 ° C. (second set temperature). . If Yes (outside air temperature> 7 ° C.) is determined, the process proceeds to step S60. If No (outside air temperature ≦ 7 ° C.) is determined, the process proceeds to step S59.

  In step S59, following the determination that the outside air temperature ≦ 7 ° C. in step S58, whether or not the state in which the refrigerant supercooling degree exceeds 5 deg (second set value) has been continuously detected for 10 seconds (set time) or longer. Judge whether or not. If it is determined Yes (refrigerant supercooling degree condition satisfied), the process proceeds to step S60. If it is determined No (refrigerant supercooling degree condition not satisfied), the process returns to variable capacity control start.

  In step S60, following the determination that the outside air temperature condition is satisfied in step S58 or the refrigerant supercooling degree condition is satisfied in step S59, the variable capacity control flag is set to OFF, and the variable capacity control flag is set to OFF. A solenoid drive command for opening the first electromagnetic valve 7 and closing the second electromagnetic valve 8 is output, and the process returns to the variable displacement control start determination (the process shown in FIG. 4A).

Next, the process leading to the present invention will be described.
The present invention relates to a liquid receiver used in a refrigeration cycle of a general automotive air conditioner composed of a compressor, a condenser (main condenser, subcool condenser), an expander (expansion valve), and an evaporator. .

  The role of the liquid receiver in the refrigeration cycle is to separate the high-pressure refrigerant in the gas-liquid mixture that has passed through the main condenser into gas and liquid, and supply it to the subcool condenser for further cooling the liquid refrigerant. This is a container for securing the heat radiation area by preventing the liquid refrigerant from staying and suppressing the pressure rise in the high pressure part. Further, the liquid receiver generally has a dryer and a strainer for removing moisture mixed in the refrigeration cycle and foreign matters.

  In the automotive air conditioner, an air heat exchange type condenser is disposed in front of the radiator in front of the vehicle for the purpose of efficiently condensing the high-temperature high-pressure gas refrigerant discharged from the compressor. However, in winter when the outside air temperature is low, when the cooling device is operated to eliminate window fogging (demist) that occurs inside the windshield, the outside air temperature is low, so the condensation performance is high and the compressor expands. The high pressure refrigerant pressure to the valve decreases. As a result, the refrigerant flow rate to the evaporator decreases, and the cooling capacity (demist performance) decreases. Further, at this time, the pressure on the low pressure side also decreases (decrease in the refrigerant evaporation temperature), so that the evaporator is likely to freeze.

In recent years, cooling performance at low loads (demist performance) tends to deteriorate due to refrigerant savings and efficiency improvement of the condenser for the purpose of improving the cooling capacity at high outside air. As a countermeasure for this problem, there is a means for increasing the set value of the expansion valve in order to secure the refrigerant flow rate. However, as the rebound, the low pressure pressure at the time of high load increases, and the cooling performance decreases.
On the other hand, there is a measure to detect the outside air temperature below a certain level, stop the compressor, and fix the fresh mode to introduce the outside air, but it cannot be compatible with the exhaust gas inflow measure.

To reduce the heat dissipation performance of the condenser and increase the high pressure when the ambient temperature is low,
(a) Decrease the amount of air passing through the condenser,
(b) raise the temperature of the air passing through the condenser,
(c) reduce the area passing through the condenser,
(d) Overfilling the condenser with refrigerant and generating a liquid refrigerant pool inside the condenser to reduce the heat radiation area,
There is a technique such as.

However, since the cooling device for an automobile is arranged in front of the vehicle for improving the efficiency of the condensation performance and uses the traveling wind at the time of traveling the vehicle, the methods (a) to (c) described above should be adopted. Is difficult. Further, as described in (d) above, it is also inconvenient to fill the refrigerant only when the outside air is low and purge the refrigerant when the outside air is high.
Therefore, in order to reduce the internal volume on the high pressure side only during low outside air and bring about the same effect as the above (d), it can be said that the structure in which the volume of the liquid receiver is varied is the most appropriate choice.

  In a general automotive air conditioner without a subcool condenser, if the receiver is heated by receiving hot air from the engine room, the degree of refrigerant supercooling at the outlet of the receiver decreases and bubbles are generated in the sight glass. To do. As a result, the refrigerant is misrecognized as insufficient and the refrigerant is overfilled. In order to prevent this problem, a structure that installs a variable capacity body (such as a bellows or a resin chamber) inside the liquid receiver, changes the internal volume of the liquid receiver, and ensures the degree of refrigerant supercooling is already a conventional technology. Although they have been proposed, all of them have a complicated structure and have the following problems.

(Japanese Utility Model Publication No. 59-195473)
(1) The variable capacity body 23 (bellows) and its control mechanism are complicated (coil spring 25, metal receiving members 26 and 27, adjustment screw 24).
(2) It has an element where refrigeration oil remains at the bottom of the liquid tank.

(Japanese Patent Laid-Open No. 63-279069)
(1) The variable capacity body (sealed container) (bellows 21,) and the control structure are complicated (coil spring 26, control gas 25, other support fittings).
(2) It also has an element where refrigeration oil remains at the bottom of the liquid tank.
(3) The refrigerant temperature inside the receiver is low when the outside air is low. When the ambient refrigerant temperature is low, the saturation pressure of the internal sealed control gas 25 of the variable capacity body is low, and there is a problem that control is difficult.

(Japanese Patent No. 2550632)
(1) In order to increase the volume of the variable capacity body 13, a pressure difference between the inlet and outlet of the condenser 2 is necessary. When the amount of refrigerant circulating in the refrigeration cycle is small (for example, when the number of revolutions of the compressor is low, or when the flow rate is adjusted by a variable capacity compressor), the pressure difference between the inlet and outlet of the condenser 2 is reduced. It is difficult to increase the volume. In addition, intentionally increasing the passage resistance of the condenser and causing a pressure difference cannot ensure refrigerant supercooling at the outlet of the condenser.
(2) When the volume of the variable capacity body (bellows 23) is controlled to the minimum, the refrigerant bypasses from the small hole 25 of about 0.2φ through the controller 17 and into the compressor inlet pipe. The flow rate decreases.
(3) When the compressor speed is low and the pressure in the low pressure pipe is high, it is difficult to reduce the volume of the variable capacity body (bellows 23).

The present inventor divides the volume in the liquid receiver in response to a request to obtain a variable capacity liquid receiver that can perform capacity change control with high stability while simplifying the structure of the liquid receiver. We focused on the fact that the capacity can be made variable.
According to this point of interest, the internal volume of the liquid receiver is divided into a plurality of parts, a check valve is installed so that each chamber communicates only in one direction, and a refrigerant inflow path is provided in each divided chamber. The configuration in which the refrigerant path is switched by a valve provided in the refrigerant inflow path is adopted.

  By adopting this configuration, the structure is simpler than the conventional structure in which a variable capacity body such as a bellows or a resin chamber is installed inside the liquid receiver. In addition, during the capacity change control, the refrigerant inflow path switching means provided outside the tank of the liquid receiver is a control target, and the capacity change control is performed by selecting a plurality of refrigerant inflow paths. For this reason, unlike the conventional structure where the variable capacity body installed inside the tank of the liquid receiver is controlled, the capacity change control is performed without being affected by changes in the internal environment of the liquid receiver, such as changes in refrigerant pressure. It can be performed stably. That is, it is possible to meet the demand to obtain a variable capacity liquid receiver that can perform capacity change control with high stability while simplifying the structure of the liquid receiver.

Next, the operation will be described.
In the variable capacity liquid receiver 3 of the first embodiment, the internal volume of the tank body 31 is divided into a first divided chamber A and a second divided chamber B by a partition wall 32, and the individual chambers A and B are allowed to flow in one direction. A check valve 33 was installed so as to communicate only at times. A first refrigerant inflow path 37 and a second refrigerant inflow path 38 are provided in both the divided chambers A and B, respectively, and the both refrigerant inflow paths 37 and 38 are detected by the controller 15 that detects the outside air temperature and the degree of refrigerant subcooling. The first electromagnetic valve 7 and the second electromagnetic valve 8 are switched and selected.
Hereinafter, the operation of the variable capacity liquid receiver 3 of the first embodiment will be described separately for “at normal outside air temperature”, “at low outside air temperature”, and “at high pressure switch operation”.

[At normal outside temperature]
When the engine is stopped, the process proceeds from step S1 to step S5 in the flowchart of FIG. 4A. When the compressor 1 is stopped, the process proceeds from step S1 to step S2 to step S5 in the flowchart of FIG. move on. Therefore, in step S5, the variable capacity control flag is set to OFF, and a command for opening the first electromagnetic valve 7 and closing the second electromagnetic valve 8 is output.

  For this reason, when the cooling device is operated for the purpose of cooling the passenger compartment during traveling in the summer, etc., in the flowchart of FIG. 4 (a), the process proceeds from step S1, step S2, step S3, step S4, step S6, Variable capacity control is started. Then, when the variable capacity control is started, the process proceeds to the flowchart of FIG. 5, but since the outside air temperature condition is not satisfied, the variable capacity control start determination from step S 51 → step S 52 to FIG. 4A in the flowchart of FIG. Returning to FIG. 4 again, the flow from step S1 in the flowchart of FIG. 4A is repeated.

  That is, at the normal outside air temperature, the output state of the command for opening the first electromagnetic valve 7 and closing the second electromagnetic valve 8 is maintained as it is, and the refrigerant from the main capacitor 2 is as shown in FIG. Then, the refrigerant flows from the refrigerant inflow path 36 through the first refrigerant inflow path 37 to the first divided chamber A. Then, the refrigerant flowing into the first division chamber A passes through the check valve 33, reaches the second division chamber B, and further flows out from the strainer 35 and the refrigerant outflow path 39 to the subcool condenser 4.

  As described above, when the normal outside air temperature is high and the load is high, the first divided flow volume is set as the receiver volume by the operation of the check valve 33 while being switched from the first refrigerant inflow path 37 to the refrigerant inflow side. It is used at the maximum volume including the chamber A and the second divided chamber B. For this reason, liquid refrigerant stagnation inside the main capacitor 2 is suppressed, and a sufficient heat radiation area is secured.

[At low outside air temperature]
In the winter when the outside air temperature is low, when the cooling system is operated to eliminate window fogging (demist) that occurs inside the windshield, the outside air temperature is low, so the condensation performance in the main condenser 2 is high and variable. If the capacity liquid receiver 3 is left at the maximum capacity, the high-pressure refrigerant pressure from the compressor 1 to the expander 5 decreases.

  However, when the air conditioner is operated for the purpose of eliminating demist in winter, in the flowchart of FIG. 4A, the process proceeds from step S1, step S2, step S3, step S4, step S6, and variable capacity control is started. The Then, when the variable capacity control is started, the process proceeds to the flowchart of FIG. 5, but since the outside air temperature condition and the refrigerant supercooling degree condition are satisfied, step S51 → step S52 → step S53 → step S54 in the flowchart of FIG. Proceed to In step S54, the variable capacity control flag is switched from OFF to ON, and a command to close the opened first electromagnetic valve 7 and open the closed second electromagnetic valve 8 is output.

  That is, when the outside air temperature condition and the refrigerant supercooling degree condition are both established at the time of low outside air in which the high-pressure side refrigerant pressure decreases, the first solenoid valve 7 is opened and the second solenoid valve 8 is closed to close the first refrigerant. From the full volume usage side (FIG. 2) where the refrigerant flows in from the inflow path 37, the first electromagnetic valve 7 is closed and the second electromagnetic valve 8 is opened, and the volume decreasing side where the refrigerant flows in from the second refrigerant inflow path 38 (FIG. 3). ) To prevent the check valve 33 from backflowing, thereby reducing the internal volume of the liquid receiver to the volume of the second divided chamber B alone.

  As a result, when the outside air temperature is low, the internal volume of the variable capacity liquid receiver 3 is reduced by the above-described series of controls, so that a liquid refrigerant pool in which the condensed liquid refrigerant stays inside the main capacitor 2 is generated. The heat dissipation area of the main capacitor 2 is reduced, and the heat dissipation performance of the main capacitor 2 is reduced. Along with the deterioration of the heat dissipation performance in the main capacitor 2, the high-pressure section refrigerant pressure (condensation pressure) increases, and the refrigerant flow rate to the evaporator 6 is secured. Therefore, the refrigerant flow rate can be secured to the evaporator 6 even at a low load, and a stable cooling capacity (demist performance) can be obtained. At this time, the pressure on the low pressure side also rises (the refrigerant evaporation temperature rises), so that the evaporator 6 is prevented from freezing.

  As described above, when the outside air temperature becomes high while maintaining the capacity reduction control for reducing the internal volume of the variable volume receiver 3, in the flowchart of FIG. 5, step S 51 → step S 55 → step The process proceeds from S56 to step S57 to step S58 to step S60. In step S60, the variable capacity control flag is switched from ON to OFF, and a command to open the closed first electromagnetic valve 7 and close the opened second electromagnetic valve 8 is output.

  Further, as described above, when the refrigerant supercooling degree is increased by maintaining the capacity reduction control for reducing the internal volume of the variable volume receiver 3, in the flowchart of FIG. 5, step S 51 → step S 55. Step S56 → Step S57 → Step S58 → Step S59 → Step S60. In step S60, the variable capacity control flag is switched from ON to OFF, and a command to open the closed first electromagnetic valve 7 and close the opened second electromagnetic valve 8 is output.

  That is, at the time of low outside air in which the high-pressure side refrigerant pressure is reduced and the internal volume of the variable volume receiver 3 is reduced, at least one of the outside air temperature condition (step S58) and the refrigerant supercooling degree condition (step S59). When one of the conditions is satisfied, the first solenoid valve 7 is closed, the second solenoid valve 8 is opened, and the first solenoid valve 7 is opened from the volume decreasing side (FIG. 3) where the refrigerant flows in from the second refrigerant inflow path 38. 2 The solenoid valve 8 is closed and switched to the full volume usage side (FIG. 2) through which the refrigerant flows in from the first refrigerant inflow path 37, and the check valve 33 is allowed to flow in the circulation direction. As shown, the first divided chamber A and the second divided chamber B are expanded to the original volume. For this reason, after being expanded to the original volume as the receiver volume, the liquid refrigerant stays inside the main capacitor 2 is suppressed, and a sufficient heat radiation area is secured.

[When high pressure switch is activated]
When the refrigerant pressure at the outlet of the main condenser 2 is high, the control to reduce the internal volume of the variable volume receiver 3 reduces the heat radiation performance in the main condenser 2 and the high pressure refrigerant pressure (condensation pressure). May rise and impair the safety of the refrigeration cycle. The same applies to the case where the internal volume reduction control of the variable capacity liquid receiver 3 is maintained as it is even when the refrigerant pressure at the outlet of the main capacitor 2 increases in the state where the internal volume of the variable capacity liquid receiver 3 is reduced.

  Therefore, in the first embodiment, the high pressure switch 12 is provided on the outlet side of the main capacitor 2 to monitor whether or not the refrigerant pressure on the outlet side of the main capacitor 2 is higher than the switch operating pressure. That is, as shown in the flowchart of FIG. 4B, when the high pressure switch 12 is operated or when there is an operation history of the high pressure switch 12, a value of 1 or more is set as the high voltage switch operation count. ing.

  Therefore, when there is an operation or operation history of the high-pressure switch 12 before the variable capacity control of the variable capacity receiver 3 is started, in the flowchart of FIG. 4A, step S1, step S2, step S3, step S5. The variable volume control of the variable volume receiver 3 is not started, and the combined volume of the first divided chamber A and the second divided chamber B is maintained as the volume of the receiver.

  Further, when it is determined that the high-pressure switch 12 is activated when the variable volume control of the variable volume receiver 3 is in the reduced volume state only by the second divided chamber B as the volume inside the liquid receiver, 5, the flow returns from step S51 to step S55 to the variable capacity control start determination. Then, in the flowchart of FIG. 4 (a), the process proceeds from step S1, step S2, step S3, and step S5, and the reduced volume by the second divided chamber B alone is set as the receiver volume of the variable capacity receiver 3. From the state, the first divided chamber A and the second divided chamber B are immediately switched to the maximum volume state.

  As described above, when there is an operation or operation history of the high-pressure switch 12, the variable capacity liquid receiver 3 is fixed in a large capacity state and fixed unless there is a clear instruction issued after the safety is confirmed. Prohibit change control. Alternatively, during control of the variable capacity liquid receiver 3 toward the reduced capacity side, the high capacity switch 12 is immediately returned to the large capacity state when the high pressure switch 12 is operated, so that the safety of the refrigeration cycle can be ensured.

Next, the effect will be described.
In the variable capacity liquid receiver 3 of the first embodiment, the effects listed below can be obtained.

  (1) In the variable capacity liquid receiver 3 that separates gas-liquid separation by allowing gas-liquid mixed high-pressure refrigerant from the main condenser 2 to flow into the refrigerant circulation path of the refrigeration cycle into the tank body 31, the internal volume of the tank body 31 Are divided into a plurality of division chambers A and B, and the division chambers A and B that are adjacent to one of the division chambers are connected to each other to permit only the refrigerant flow in the refrigerant circulation direction. A plurality of check valves 33 that block the flow of refrigerant in the direction opposite to the direction and a plurality of divided chambers A and B that are branched from the refrigerant inflow path 36 from the main condenser 2 and communicate with the respective chambers A and B. Since the refrigerant inflow paths 37 and 38 and the refrigerant inflow path switching means for switching and selecting the plurality of refrigerant inflow paths 37 and 38 are provided, the control stability of the capacity change can be ensured with a simple structure. .

  (2) The refrigerant inflow path switching means includes electromagnetic valves 7 and 8 for switching and selecting the plurality of refrigerant inflow paths 37 and 38, and a controller 15 for controlling a valve opening / closing operation of the electromagnetic valves 7 and 8. The controller 15 outputs a control command to the electromagnetic valves 7 and 8 for reducing the tank volume obtained by adding up the volumes of the divided chambers A and B as the load detected by the load detecting means decreases. The variable capacity control of the variable capacity liquid receiver 3 can be easily performed by the valve opening / closing operation control of the electromagnetic valves 7 and 8 that switch and select the refrigerant inflow paths 37 and 38.

  (3) The load detection means is an outside air temperature sensor 11, a high-pressure refrigerant saturation temperature sensor 9, and a supercooling refrigerant temperature sensor 10, and the controller 15 depends on a difference between the high-pressure refrigerant saturation temperature and the supercooling refrigerant temperature. In order to calculate the refrigerant supercooling degree and perform capacity change control using the outside air temperature information and the refrigerant supercooling degree information as control input information, the load of the refrigeration cycle having the main capacitor 2 and the variable capacity receiver 3 is set to the outside air temperature information. And the refrigerant supercooling degree information can be accurately detected, and the variable capacity control of the variable capacity liquid receiver 3 can be appropriately performed according to the load.

  (4) The high-pressure switch 12 that operates at high pressure is provided in the refrigerant inflow path 36 from the main capacitor 2, and the controller 15 detects the operation of the high-pressure switch 12 or the operation history of the high-pressure switch 12 is In some cases, switching from the high volume state to the low volume state is prohibited and the high volume state is maintained, so that an excessive increase in the refrigerant pressure on the outlet side of the main condenser 2 can be prevented and the safety of the refrigeration cycle can be ensured. it can.

  (5) The controller 15 has a condition that the outside air temperature is less than 5 ° C. (Yes in Step S52) and a condition that the state where the refrigerant supercooling degree is less than 3 deg is continued for 10 seconds or longer (Yes in Step S53). Once established, the air conditioner is operated to eliminate the demist generated inside the windshield in winter to switch from the high volume state, which is the sum of the volumes of the divided chambers A and B, to the low volume state, where the number of division chambers is reduced. In this case, it is possible to obtain stable demisting performance by securing the refrigerant flow rate to the evaporator 6 and to prevent the evaporator 6 from freezing and the like.

  (6) The controller 15 continues the condition that the outside air temperature exceeds 7 ° C higher than 5 ° C (Yes in step S58) and the state where the refrigerant supercooling degree exceeds 5deg larger than 3deg for 10 seconds or more. If at least one of the conditions (Yes in step S59) is satisfied, the low volume state with the reduced number of divided chambers is switched to the high volume state with the combined volumes of the divided chambers A and B combined. The low volume state can be switched to the high volume state at an appropriate timing without causing control hunting of the variable capacity control.

  (7) The plurality of division chambers are two chambers, a first division chamber A and a second division chamber B, and a first refrigerant inflow path 37 having a first electromagnetic valve 7 is communicated with the first division chamber A. The second refrigerant inflow path 38 having the second electromagnetic valve 8 is provided in communication with the second divided chamber B. The controller 15 opens the first electromagnetic valve 7 and opens the second electromagnetic valve 8. By closing, the volume of both the divided chambers A and B is summed up to a high volume state, and the first electromagnetic valve 7 is closed and the second electromagnetic valve 8 is opened to reduce the volume only by the volume of the second divided chamber B. In order to achieve the volume state, it is possible to perform the variable capacity control for switching between the high volume state and the low volume state while using the variable capacity liquid receiver 3 having a very simple structure by the minimum division of two chambers.

  The second embodiment is an example in which the variable capacity control is performed after the refrigerant recovery state has elapsed when switching from the high volume state to the low volume state.

First, the configuration will be described.
FIG. 6 is an overall system diagram showing a refrigeration cycle of an automotive air conditioner to which the variable capacity liquid receiver of Example 2 is applied.

  As shown in FIG. 6, the refrigeration cycle of the automotive air conditioner to which the variable capacity liquid receiver of Example 2 is applied includes a compressor 1, a main condenser 2 (condenser), a variable capacity liquid receiver 3, and the like. , Subcool condenser 4 (supercooled condenser), expander 5 (expansion valve), evaporator 6 (evaporator), first electromagnetic valve 7 (refrigerant inflow path switching means), and second electromagnetic valve 8 (refrigerant). Inflow path switching means), high-pressure refrigerant saturation temperature sensor 9 (load detection means), supercooling refrigerant temperature sensor 10 (load detection means), outside air temperature sensor 11 (load detection means), high-pressure switch 12, and pressure A switch 13, a thermal cylinder 14, and a controller 15 (refrigerant inflow path switching means) are provided.

  The pressure switch 13 is disposed in the refrigerant outflow path 39 and detects the refrigerant pressure on the outlet side of the variable capacity liquid receiver 3. Other configurations are the same as those of the first embodiment shown in FIG.

  FIG. 7 is a cross-sectional view showing the variable capacity liquid receiver at the normal outside air temperature according to the second embodiment. FIG. 8 is a cross-sectional view showing the variable capacity liquid receiver during the refrigerant recovery operation of the second embodiment. FIG. 9 is a cross-sectional view illustrating the variable capacity liquid receiver at the time of low outside air temperature (when the capacity is decreased) according to the second embodiment.

  As shown in FIGS. 7 to 9, the variable capacity liquid receiver 3 of Example 2 includes a tank body 31, a partition wall 32, a first divided chamber A, a second divided chamber B, and a check valve 33. The dryers 34, 34, the strainer 35, the refrigerant inflow path 36, the first refrigerant inflow path 37, the second refrigerant inflow path 38, and the refrigerant outflow path 39 are provided. That is, since it is the same structure as the variable capacity liquid receiver 3 of Example 1, description of each component is abbreviate | omitted.

FIG. 10 is a flowchart showing the flow of the variable capacity control process of the variable capacity receiver 3 executed by the controller 15 of the second embodiment. Each step will be described below.
Note that steps S101 to S110 correspond to the processes in steps S51 to S60 in the flowchart shown in FIG. 5, and therefore, description of these steps S101 to S110 (excluding step S104 ′) will be given. Is omitted.

  In step S111, following the determination that the refrigerant subcooling condition is established in step S103, the refrigerant recovery control flag is set to ON, the first electromagnetic valve 7 is closed, and the second electromagnetic valve is closed. A solenoid drive command for closing 8 is output, and the process proceeds to step S112.

  In step S112, following the output of the solenoid drive command for setting the refrigerant recovery control flag = ON and obtaining the refrigerant recovery state, it is determined whether the high-pressure switch operation count is 1 or more. If Yes (high pressure switch operation count ≧ 1) is determined, the process returns to the variable capacity control start determination (the process shown in FIG. 4A), and if No (high pressure switch operation count = 0) is determined, step S113 is performed. Migrate to

  Step S113 determines whether or not the refrigerant pressure value detected by the pressure switch 13 has become an arbitrary value for performing the switch ON operation, following the determination that the high-pressure switch operation count = 0 in Step S112. If it is determined No (refrigerant pressure value <any value), the process returns to step S111, and if Yes (refrigerant pressure value ≧ any value) is determined, the process proceeds to step S104 ′.

In step S104 ′, following the determination that the refrigerant pressure value ≧ an arbitrary value in step S113, the refrigerant recovery control flag is set to refrigerant recovery control flag = OFF, the variable capacity control flag is set to variable capacity control flag = ON. And a solenoid drive command for closing the first electromagnetic valve 7 and opening the second electromagnetic valve 8 is output, and the process returns to the variable capacity control start.
A flowchart corresponding to FIG. 4 of the first embodiment is also used in the second embodiment, but is not shown because it is the same.

Next, the operation will be described.
When the capacity of the variable capacity liquid receiver 3 is reduced, if the refrigerant remains in the first divided chamber A where no refrigerant flows, and as a result, the pressure on the high pressure refrigerant side is difficult to increase, the variable capacity liquid receiver It is preferable to perform the refrigerant recovery operation in a transition period in which the total volume of 3 is used and the capacity is reduced. The variable capacity liquid receiver 3 of Example 2 has been made paying attention to this point. Hereinafter, the variable capacity control operation at the low outside air temperature in the variable capacity receiver 3 of the second embodiment will be described.

[At low outside air temperature]
When the cooling device is operated for the purpose of eliminating the demist in winter, in the flowchart of FIG. 4 (a), the process proceeds from step S1, step S2, step S3, step S4, step S6, and variable capacity control is started. Then, when the variable capacity control is started, the process proceeds to the flowchart of FIG. 10, but since the outside air temperature condition and the refrigerant supercooling degree condition are satisfied, in the flowchart of FIG. 10, step S101 → step S102 → step S103 → step S111. Proceed to In step S111, the refrigerant recovery control flag is set to ON, and a solenoid drive command for closing the first electromagnetic valve 7 and closing the second electromagnetic valve 8 is output.

  That is, when the outside air temperature condition and the refrigerant supercooling degree condition are both established at the time of low outside air in which the high-pressure side refrigerant pressure decreases, the first solenoid valve 7 is opened and the second solenoid valve 8 is closed to close the first refrigerant. From the full volume usage side (FIG. 7) through which the refrigerant flows in from the inflow path 37, the first electromagnetic valve 7 and the second electromagnetic valve 8 are closed to prevent the refrigerant from flowing in from both the refrigerant inflow paths 37 and 38. The refrigerant in the first division chamber A flows into the second division chamber B by the operation of switching to the side (FIG. 8) and allowing the check valve 33 to flow in the circulation direction. As a result, the refrigerant is recovered from the tank body 31 by removing the refrigerant.

  Then, the process proceeds from step S111 to step S112 → step S113, and as long as it is determined No in step S113, the process of proceeding from step S111 → step S112 → step S113 is repeated. In step S104 ′, the variable capacity control flag is set. Is switched from OFF to ON, and the refrigerant recovery operation shown in FIG. 8 is maintained.

  As a result, when the outside air temperature is low, control is performed to switch from the full volume use side (FIG. 7) to the refrigerant recovery side (FIG. 8), so that when the capacity of the variable volume receiver 3 is reduced, The refrigerant does not remain in the first divided chamber A that does not flow. As a result, the pressure on the high-pressure refrigerant side quickly increases. And since the refrigerant of the variable capacity receiver 3 is lost and the flow of the refrigerant is temporarily stopped, a liquid refrigerant pool in which the condensed liquid refrigerant stays inside the main capacitor 2 is generated, and the entire volume usage side (FIG. Immediately after switching from 7) to the refrigerant recovery side (FIG. 8), the heat dissipation area of the main capacitor 2 is effectively reduced, and the heat dissipation performance of the main capacitor 2 is reduced.

  Next, when the pressure condition of step S113 is established while maintaining the refrigerant recovery operation shown in FIG. 8, the process proceeds from step S113 to step S104 ′, and in step S104 ′, the refrigerant recovery control flag is rewritten to OFF, While the variable capacity control flag is rewritten to ON, a command to open the closed second electromagnetic valve 8 is output while the first electromagnetic valve 7 remains closed.

  That is, when the pressure condition is satisfied in the refrigerant recovery operation state, the capacity for inflowing the refrigerant from the second refrigerant inflow path 38 from the refrigerant recovery operation state shown in FIG. 8 by closing the first electromagnetic valve 7 and opening the second electromagnetic valve 8. By switching to the decreasing side (FIG. 9) and preventing the check valve 33 from backflowing, the internal volume of the liquid receiver is reduced to the volume of the second divided chamber B alone.

  As a result, when the outside air temperature is low, the internal volume of the variable capacity liquid receiver 3 is reduced by the above-described series of controls, so that a liquid refrigerant pool in which the condensed liquid refrigerant stays inside the main capacitor 2 is generated. The heat dissipation area of the main capacitor 2 is reduced, and the heat dissipation performance of the main capacitor 2 is reduced. Along with the deterioration of the heat dissipation performance in the main capacitor 2, the high-pressure section refrigerant pressure (condensation pressure) increases, and the refrigerant flow rate to the evaporator 6 is secured. Therefore, the refrigerant flow rate can be secured to the evaporator 6 even at a low load, and a stable cooling capacity (demist performance) can be obtained. At this time, the pressure on the low pressure side also rises (the refrigerant evaporation temperature rises), so that the evaporator 6 is prevented from freezing.

  The switching from the capacity reduction state shown in FIG. 9 to the full capacity use operation state shown in FIG. 7 is performed while the capacity reduction control is maintained without interposing the refrigerant recovery operation as in the first embodiment. When the temperature rises, or when the refrigerant supercooling degree is increased by maintaining the capacity reduction control to reduce the internal volume of the variable capacity liquid receiver 3, the capacity reduction state is switched to the full capacity use operation state. It is done. Other operations are the same as those in the first embodiment, and a description thereof will be omitted.

Next, the effect will be described.
In the variable capacity liquid receiver of the second embodiment, in addition to the effects (1) to (7) of the first embodiment, the effects listed below can be obtained.

  (8) A pressure switch 13 for detecting the refrigerant pressure on the outlet side of the variable volume receiver 3 is provided, and the controller 15 determines that the condition that the outside air temperature is less than 5 ° C. (Yes in step S102) and the refrigerant supercooling degree. When the condition that the state of less than 3 deg is continued for 10 seconds or longer (Yes in step S103) is established, the refrigerant is recovered from the divided chambers A and B from the high volume state in which the volumes of the divided chambers A and B are added together. Switch to the refrigerant recovery state to be performed (step S111), and in this refrigerant recovery state, if the outlet side refrigerant pressure detection value of the variable capacity receiver 3 detects an arbitrary value (Yes in step S113), the refrigerant recovery state causes the division chamber to Therefore, when the capacity of the variable volume receiver 3 is reduced, the refrigerant from the first divided chamber A is surely removed, and the pressure on the high pressure refrigerant side is quickly increased. Can be raised To, immediately after switching to the refrigerant recovery side from the total volume consuming, can effectively reduce the radiation performance of the main capacitor 2.

  (9) The plurality of division chambers are two chambers, a first division chamber A and a second division chamber B, and a first refrigerant inflow path 37 having a first electromagnetic valve 7 is communicated with the first division chamber A. The second refrigerant inflow path 38 having the second electromagnetic valve 8 is provided in communication with the second divided chamber B. The controller 15 opens the first electromagnetic valve 7 and opens the second electromagnetic valve 8. Refrigerant that collects refrigerant from the divided chambers A and B by closing the first electromagnetic valve 7 and the second electromagnetic valve 8 together by closing the first and second electromagnetic valves 7 and 8 together. Since the first electromagnetic valve 7 is closed and the second electromagnetic valve 8 is opened by the recovery state, the volume is reduced only by the volume of the second divided chamber B. Switch to high volume state, refrigerant recovery state, and low volume state using variable capacity liquid receiver 3 and two solenoid valves 7 and 8 Variable capacity control can be performed.

  The third embodiment is an example in which two electromagnetic valves 7 and 8 are used for switching the refrigerant inflow paths 37 and 38 in the first and second embodiments, but a three-way valve is used as an alternative to the electromagnetic valves 7 and 8. is there.

First, the configuration will be described.
FIG. 11 is a cross-sectional view showing the variable capacity liquid receiver at the normal outside air temperature, the refrigerant recovery operation, and the low load (when the capacity is reduced) according to the third embodiment.

  In the variable capacity liquid receiver 3 of the third embodiment, the first refrigerant inflow path 37 is provided in the first division chamber A, and the second refrigerant inflow path 38 is provided in the second division chamber B. Yes. The three-way valve 16 is provided at a branch position where the refrigerant inflow path 36 branches into a first refrigerant inflow path 37 and a second refrigerant inflow path 38. The valve position of the three-way valve 16 is switched by a motor actuator 17 that is driven by a drive command from the controller 15.

  The controller 15 sets the three-way valve 16 to the first refrigerant inflow path open position (the position shown on the left side in FIG. 11), thereby bringing the volume of both the divided chambers A and B into a high volume state. 16 is set to a refrigerant recovery state in which refrigerant is recovered from the divided chambers A and B by setting the first and second refrigerant inflow passages to the closed position (position shown in the center of FIG. 11), and the three-way valve 16 enters the second refrigerant inflow. By setting the path to the open position (the position shown on the right side of FIG. 11), a low volume state is obtained only by the volume of the second divided chamber B. Since other configurations are the same as those of the second embodiment, illustration and description thereof are omitted.

Next, the operation will be described.
This three-way valve 16 can block the refrigerant inflow to the variable capacity liquid receiver 3, and at normal high loads, detects the outside air temperature and switches the three-way valve 16 to the first refrigerant inflow path 37 (FIG. 11). The left side of the variable capacity receiver 3 is used to the maximum extent. At a low load when the high-pressure side refrigerant pressure decreases, the outside air temperature and the degree of refrigerant supercooling are detected, and the three-way valve 16 is fully closed for an arbitrary time with the compressor 1 operated (center in FIG. 11). The refrigerant in the liquid container 3 is recovered. And the pressure at the time of completion | finish of refrigerant | coolant recovery is detected with the pressure switch 13, and after switching, it switches to the 2nd refrigerant | coolant inflow path 38 (right side of FIG. 11).

  When switching to the second refrigerant inflow path 38, as shown on the right side of FIG. 11, the operation of the check valve 33 causes the refrigerant to flow only into the second divided chamber B, resulting in a reduced internal volume. Note that switching from the low load to the high load switches the three-way valve 16 to the state shown on the left side of FIG. 11 without performing the refrigerant recovery operation. That is, Example 3 shows the same operation as Example 2 only in that it differs from Example 2 only in that three-way valve 16 is used instead of two electromagnetic valves 7 and 8.

Next, the effect will be described.
In the variable capacity liquid receiver 3 of the third embodiment, in addition to the effects (1) to (7) of the first embodiment and the effect (8) of the second embodiment, the following effects can be obtained. it can.

  (10) The plurality of division chambers are two chambers, a first division chamber A and a second division chamber B, and a first refrigerant inflow passage 37 is provided in the first division chamber A in communication with the second division chamber A. The dividing chamber B is provided with a second refrigerant inflow path 38 communicating therewith, and the three-way valve 16 is provided at a branch position where the refrigerant inflow path 36 branches into a first refrigerant inflow path 37 and a second refrigerant inflow path 38. The controller 15 places the three-way valve 16 in the high volume state by adding the volumes of the two divided chambers A and B by setting the three-way valve 16 to the first refrigerant inflow path open position, and closes the three-way valve 16 in the first and second refrigerant inflow paths. By setting the position, the refrigerant is recovered from the divided chambers A and B, and by setting the three-way valve 16 to the open position of the second refrigerant inflow path, the low volume state is obtained only by the volume of the second divided chamber B. Therefore, a variable capacity receiver with an extremely simple structure with a minimum division of two rooms. And vessel 3, while a refrigerant inlet path switching structure using only one-way valve 16, it is possible to perform variable displacement control of switching the high volume state and the refrigerant recovery state and a low volume state.

  As mentioned above, although the variable capacity liquid receiver of this invention has been demonstrated based on Example 1-3, it is not restricted to these Examples about a concrete structure, Each claim of a claim Design changes and additions are permitted without departing from the spirit of the invention according to the paragraph.

  In Examples 1 to 3, the flow path is set to be switched at an outside air temperature of less than 5 ° C. and a refrigerant supercooling degree of less than 3 deg. The first set temperature and the first temperature are set for each feature of the refrigeration cycle employed. The set value can be set arbitrarily.

  In Examples 1-3, the example divided into two rooms with the same volume was shown, but it is good also as an example divided into three or more rooms. Furthermore, regarding the ratio of the divided internal volume, in Examples 1 to 3, the volume of the first divided chamber A is 175 cc and the volume of the second divided chamber is 175 cc. Can be set arbitrarily. Of course, a plurality of check valves may be provided depending on the internal volume or the number of divisions of the variable capacity liquid receiver.

  In the second and third embodiments, the example in which the controller detects an arbitrary pressure value such as the pressure sensor (pressure SW) added to the refrigeration cycle is used to determine whether the refrigerant recovery control is finished. If it is, the refrigerant recovery operation may be performed for an arbitrary time set by the timer value.

  In short, it is installed at the communication position between the divided chamber formed by dividing the internal volume of the tank body into a plurality of divided chambers and the adjacent divided chamber among the divided chambers, and only the refrigerant flow in the refrigerant circulation direction is permitted, and the refrigerant circulation A check valve that prevents the refrigerant flow in the direction opposite to the direction, a plurality of refrigerant inflow paths that branch from the refrigerant inflow path from the condenser and that communicate with each of the plurality of divided chambers, The present invention is not limited to the first to third embodiments as long as it includes a refrigerant inflow path switching unit that switches and selects the refrigerant inflow path.

  In Examples 1-3, the example which applies a variable capacity | capacitance liquid receiver to the refrigerating cycle of the cooling device for motor vehicles of an engine vehicle was shown. However, it can also be applied to a variable capacity receiver for a refrigeration cycle of a cooling system for an automobile such as a hybrid vehicle or an electric vehicle, and further, a variable capacity of a refrigeration cycle for a home cooling system or a business office cooling system. It can also be applied to a liquid receiver. Moreover, in Examples 1-3, although the application example to the variable capacity | capacitance liquid receiver of the refrigerating cycle provided with the main capacitor and the subcool condenser was shown, it applies also to the variable capacity liquid receiver of the refrigerating cycle which does not have a subcool condenser. it can. In short, the present invention can be applied to any variable capacity liquid receiver that has a condenser in the refrigerant circulation path of the refrigeration cycle and separates the gas-liquid mixed high-pressure refrigerant from the condenser into the tank body for gas-liquid separation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing a refrigeration cycle of an automotive cooling device to which a variable capacity liquid receiver of Example 1 is applied. 2 is a cross-sectional view showing a variable capacity liquid receiver at a normal outside air temperature in Example 1. FIG. It is sectional drawing which shows the variable capacity | capacitance liquid receiver at the time of the low external temperature of Example 1 (at the time of capacity | capacitance reduction). FIG. 4A is a control process flowchart executed by the controller 15 of the first embodiment. FIG. 4A shows the flow of variable capacity control start determination processing, and FIG. 4B shows the flow of high-voltage switch counter processing. 3 is a flowchart showing a flow of variable capacity control processing of the variable capacity receiver 3 executed by the controller 15 of the first embodiment. It is a whole system figure which shows the refrigerating cycle of the cooling device for motor vehicles to which the variable capacity | capacitance liquid receiver of Example 2 was applied. It is sectional drawing which shows the variable capacity | capacitance liquid receiver at the time of the normal outside temperature of Example 2. FIG. 6 is a cross-sectional view showing a variable capacity liquid receiver during a refrigerant recovery operation of Example 2. FIG. It is sectional drawing which shows the variable capacity | capacitance liquid receiver at the time of the low external air temperature of Example 2 (at the time of capacity | capacitance reduction). It is a flowchart which shows the flow of the variable capacity | capacitance control processing of the variable capacity liquid receiver 3 performed with the controller 15 of Example 2. FIG. It is sectional drawing which shows the variable capacity | capacitance liquid receiver at the time of the normal external temperature of Example 3, the refrigerant | coolant collection | recovery operation | movement time, and the time of low load (at the time of capacity | capacitance reduction).

Explanation of symbols

1 Compressor 2 Main condenser (condenser)
3 Variable capacity receiver 4 Subcool condenser (supercooled condenser)
5 Inflator (Expansion valve)
6 Evaporator
7 1st solenoid valve (refrigerant inflow path switching means)
8 Second solenoid valve (refrigerant inflow path switching means)
9 High-pressure refrigerant saturation temperature sensor (load detection means)
10 Supercooled refrigerant temperature sensor (load detection means)
11 Outside temperature sensor (load detection means)
12 High pressure switch 13 Pressure switch 14 Thermosensitive cylinder 15 Controller (refrigerant inflow path switching means)
16 Three-way valve 17 Motor actuator

Claims (10)

In a variable capacity liquid receiver having a condenser in a refrigerant circulation path of a refrigeration cycle, and gas-liquid separation by flowing a high-pressure refrigerant mixed with gas and liquid from the condenser into a tank body,
A division chamber formed by dividing the internal volume of the tank body into a plurality of; and
A check valve that is installed at a communication position between adjacent division chambers among the plurality of division chambers, permits only refrigerant flow in the refrigerant circulation direction, and prevents refrigerant flow in the direction opposite to the refrigerant circulation direction;
A plurality of refrigerant inflow paths branched from the refrigerant inflow path from the condenser and provided in communication with each of the plurality of divided chambers;
Refrigerant inflow path switching means for switching and selecting the plurality of refrigerant inflow paths;
A variable capacity liquid receiver characterized by comprising: The variable capacity receiver according to claim 1,
The refrigerant inflow path switching means includes an electromagnetic valve that switches and selects the plurality of refrigerant inflow paths, and a controller that controls a valve opening / closing operation of the electromagnetic valve,
The variable capacity liquid receiver, wherein the controller outputs a control command to the electromagnetic valve to reduce a tank volume obtained by adding up the volumes of the divided chambers as the load detected by the load detecting means is lower. The variable capacity liquid receiver according to claim 2,
The load detection means is an outside air temperature sensor, a high-pressure refrigerant saturation temperature sensor, and a supercooling refrigerant temperature sensor,
The controller calculates a refrigerant supercooling degree based on a difference between the high-pressure refrigerant saturation temperature and the supercooling refrigerant temperature, and performs capacity change control using the outside air temperature information and the refrigerant supercooling degree information as control input information. Volume receiver. The variable capacity liquid receiver according to claim 2 or 3,
Provide a high pressure switch that operates at high pressure in the refrigerant inflow path from the condenser,
The controller prohibits switching from a high volume state to a low volume state and maintains a high volume state when the operation of the high pressure switch is detected or when there is an operation history of the high pressure switch. Variable capacity receiver. In the variable capacity liquid receiver according to claim 3 or 4,
When the condition that the outside air temperature is less than the first set temperature and the condition that the refrigerant supercooling degree is less than the first set value are continued for a set time or longer, the controller adds the volumes of the plurality of divided chambers. A variable capacity liquid receiver characterized by switching from a high volume state to a low volume state with a reduced number of divided chambers. The variable capacity liquid receiver according to claim 5,
The controller continues a condition that the outside air temperature exceeds a second set temperature higher than the first set temperature and a state where the refrigerant supercooling degree exceeds a second set value larger than the first set value for a set time or longer. When at least one of the conditions is satisfied, the variable capacity liquid receiver is switched from a low volume state in which the number of divided chambers is reduced to a high volume state in which the volumes of the plurality of divided chambers are combined. . The variable capacity liquid receiver according to any one of claims 1 to 6,
The plurality of division chambers are two chambers, a first division chamber and a second division chamber,
A first refrigerant inflow path having a first electromagnetic valve is provided in communication with the first division chamber,
A second refrigerant inflow path having a second electromagnetic valve is provided in communication with the second divided chamber,
The controller opens the first solenoid valve and closes the second solenoid valve so as to obtain a high volume state in which the volumes of both divided chambers are added, closes the first solenoid valve, and opens the second solenoid valve. A variable capacity liquid receiver characterized by having a low volume state only by the volume of the second divided chamber. In the variable capacity liquid receiver according to claim 3 or 4,
A pressure sensor for detecting the refrigerant pressure on the outlet side of the receiver is provided,
When the condition that the outside air temperature is less than the first set temperature and the condition that the refrigerant supercooling degree is less than the first set value are continued for a set time or longer, the controller adds the volumes of the plurality of divided chambers. Switch from the high volume state to the refrigerant recovery state in which the refrigerant is recovered from the plurality of division chambers, and when the receiver outlet side refrigerant pressure detection value reaches the set value in this refrigerant recovery state, the number of division chambers is reduced from the refrigerant recovery state. A variable capacity liquid receiver characterized by switching to a low volume state. The variable capacity liquid receiver according to claim 8,
The plurality of division chambers are two chambers, a first division chamber and a second division chamber,
A first refrigerant inflow path having a first electromagnetic valve is provided in communication with the first division chamber,
A second refrigerant inflow path having a second electromagnetic valve is provided in communication with the second divided chamber,
The controller opens the first solenoid valve and closes the second solenoid valve so as to obtain a high volume state in which the volumes of both divided chambers are added, and closes both the first solenoid valve and the second solenoid valve. The variable capacity receiving system is characterized in that a refrigerant recovery state in which refrigerant is recovered from the division chamber is set, and the first electromagnetic valve is closed and the second electromagnetic valve is opened, so that the low volume state is obtained only by the volume of the second division chamber. Liquid container. The variable capacity liquid receiver according to claim 8,
The plurality of division chambers are two chambers, a first division chamber and a second division chamber,
A first refrigerant inflow path is provided in communication with the first divided chamber;
A second refrigerant inflow path is provided in communication with the second divided chamber;
A three-way valve is provided at a branch position that branches from the refrigerant inflow path to the first refrigerant inflow path and the second refrigerant inflow path,
The controller sets the three-way valve to the first refrigerant inflow path open position to obtain a high volume state in which the volumes of both the divided chambers are combined, and sets the three-way valve to the first and second refrigerant inflow path closed positions. A variable capacity liquid receiver characterized by having a refrigerant recovery state in which the refrigerant is recovered from the division chamber, and having a three-way valve in a second refrigerant inflow path open position to provide a low volume state only by the volume of the second division chamber. .

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