JPH08233411A - Cooling device - Google Patents

Abstract

PURPOSE: To provide a cooling device which favorably cools the ambient atmosphere without being affected by the operating environment. CONSTITUTION: A diaphragm 31 partitions a space in a case 30 into a first pressure chamber 32 and second pressure chamber 33. To the first pressure chamber 32, the pressure in a pressure bulb 6 is applied through a refrigerant passage 40. To the second pressure chamber 33, a refrigerant pressure in an outlet side piping of an evaporator 5 is applied through a joint 42 and the inside of a refrigerant container 43. The diameter of the refrigerant container 43 is larger than the diameter of an external equalizing capillary 41. Even when the rotating number of a compressor 1 suddenly varies, and the refrigerant pressure in the outlet side piping of the evaporator 5 suddenly varies, because of a large capacity of the refrigerant container 43, a refrigerant gently flows out or flows in from the refrigerant container 43 to the evaporator 5 side or expansion valve 4 side, and the pressure of the second pressure chamber 33 gently varies. By this method, the quantity of the refrigerant which is discharged from the expansion valve to the evaporator 5 is appropriately controlled regardless of the ambient environment.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cooling device.

[0002]

2. Description of the Related Art Conventionally, for example, a refrigerating cycle of a vehicle-mounted cooling device circulates a refrigerant as follows.
The high temperature and high pressure gaseous refrigerant in the compressor is liquefied by cooling it in the condenser, and this liquefied refrigerant is discharged into the low pressure evaporator through the throttle in the expansion valve, and is vaporized by the adiabatic expansion action to reduce the low temperature and low pressure. After atomization, the evaporator cools the air inside the passenger compartment by exchanging heat between the low temperature refrigerant and the air inside the passenger compartment, and the refrigerant vaporized in the evaporator is heated again to high temperature and high pressure in the compressor.

The expansion valve is a diaphragm due to the difference between the first pressure chamber in the heat-sensitive cylinder attached to the outlet pipe of the evaporator and the second pressure chamber in which the pressure on the outlet side of the evaporator is applied. Is adjusted to adjust the discharge opening area, which is the flow passage area of the refrigerant, to adjust the amount of refrigerant discharged to the evaporator. The pressure of the first pressure chamber acts in the direction of increasing the blowout opening area, and the pressure of the second pressure chamber acts in the direction of decreasing the blowout opening area.

In such a cooling system, if the operation start and stop are frequently repeated depending on the running state of the vehicle,
For example, even if the refrigerant intake amount of the compressor increases as the engine speed increases and the refrigerant pressure on the evaporator outlet side sharply decreases and the refrigerant temperature drops, it takes time to detect the temperature, so the pressure inside the heat-sensitive cylinder is It decreases slowly. On the other hand, since the decrease in the refrigerant pressure on the outlet side of the evaporator is quickly transmitted to the second pressure chamber,
The pressure drops faster in the second pressure chamber than in the first pressure chamber. Therefore, the area of the outlet opening is increased, and a large amount of the refrigerant is discharged to the low pressure evaporator side. Then, a so-called liquid return occurs in which the discharged refrigerant is not completely vaporized in the evaporator and a part of it remains liquid and returns to the compressor. When the liquid return occurs, the liquid refrigerant is compressed in the compressor. Then, an excessive load may be applied to the valve and the like in the compressor, which may cause valve damage.

[0005]

In order to solve such a problem, a rapid pressure change on the evaporator outlet side is introduced into the introduction hole or the introduction pipe of the expansion valve for transmitting the refrigerant on the evaporator outlet side to the second pressure chamber. It is conceivable to provide a damping mechanism such as a diaphragm or a cushioning material for alleviating the above. As a result, the pressure transmission to the second pressure chamber can be delayed, and the time difference from the delay in the pressure sensing by the heat sensitive cylinder can be reduced. However, if a damping mechanism that alleviates the pressure change at the outlet side of the evaporator is provided, foreign matter or oxidation products mixed in the refrigerant are easily clogged in the damping mechanism, resulting in poor control of the expansion valve. There is a fear.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a cooling device which can cool the ambient atmosphere satisfactorily regardless of the operating environment.

[0007]

According to a first aspect of the present invention, there is provided a cooling device, wherein a refrigerant flowing from an inlet passage is blown out to an outlet passage through a throttle and evaporated from the outlet passage. Expansion valve for discharging refrigerant to the evaporator, the first pressure chamber being attached to the outlet side pipe of the evaporator, to which the pressure in the heat-sensitive cylinder is changed according to the refrigerant temperature in the outlet side pipe, and the outlet side The second pressure chamber to which the pressure in the pipe is applied is partitioned from the second pressure chamber, and the thin film is displaced according to the pressure difference between the first pressure chamber and the second pressure chamber, and the opening area of the diaphragm is changed according to the displacement amount of the thin film. Expansion valve having a variable throttle means for adjusting the amount of the refrigerant blown from the inlet passage to the outlet passage through the throttle, and the refrigerant communicating the inside of the outlet side pipe with the second pressure chamber. For refrigerant piping that forms a flow path Attached to the column, characterized in that it comprises a coolant tank having a space portion having a diameter to form a large part of the refrigerant passage than the refrigerant pipe.

A cooling device according to a second aspect of the present invention is the cooling device according to the first aspect, wherein the variable throttle means is a working rod that reciprocates along with the displacement of the thin film, and the refrigerant downstream side following the throttle. A valve seat provided on the inlet flow passage side of the partition wall that partitions the inlet flow passage and the outlet flow passage while forming a blow-out hole through which the actuation rod is inserted.
A valve member that is housed in the inlet passage, forms the throttle with the valve seat, and contacts the actuation rod on the valve seat side; and a biasing means that biases the valve member toward the valve seat. Is characterized by.

A cooling device according to a third aspect of the present invention is characterized in that, in the cooling device according to the first or second aspect, the refrigerant container is installed close to the expansion valve.

[0010]

According to the cooling device of the first or third aspect of the present invention, the displacement amount of the thin film due to the pressure difference between the first pressure chamber and the second pressure chamber provided in the expansion valve and partitioned by the thin film. The amount of the refrigerant blown from the inlet flow path of the expansion valve to the outlet flow path, that is, the amount of the refrigerant discharged to the evaporator is adjusted accordingly. A pressure in the heat-sensitive cylinder, which changes in pressure depending on the refrigerant temperature in the outlet side pipe of the evaporator, is applied to the first pressure chamber, and a refrigerant flow path for transmitting the refrigerant pressure on the outlet side of the evaporator is formed in the second pressure chamber. A refrigerant container having a diameter larger than that of the refrigerant pipe is attached in series to the refrigerant pipe. As a result, even if the refrigerant pressure in the outlet side pipe of the evaporator changes abruptly due to, for example, abrupt changes in the rotation of the compressor, if the refrigerant pressure in the outlet side pipe rises, the refrigerant container moves to the second pressure chamber. When the refrigerant gradually flows into the outlet side pipe and the refrigerant pressure in the outlet side pipe decreases, the refrigerant slowly flows out from the refrigerant container to the evaporator side refrigerant pipe, so that the refrigerant also slowly flows out from the second pressure chamber. Therefore, even if the refrigerant pressure in the outlet side pipe of the evaporator changes abruptly, the pressure in the second pressure chamber changes gently. Also, since a time delay occurs even when the pressure inside the heat-sensitive cylinder fluctuates due to the detection of a temperature change due to a sudden pressure change occurring in the outlet side pipe of the evaporator, the pressure in the first pressure chamber also changes gently. To do.
As a result, the pressure difference between the first pressure chamber and the second pressure chamber changes gently even if a sudden change in the refrigerant pressure occurs in the outlet side pipe of the evaporator, so that an appropriate amount of refrigerant is output from the expansion valve. It can be discharged to the evaporator. Further, since the refrigerant container has a diameter larger than that of the refrigerant pipe, the inside of the refrigerant container is not blocked by foreign substances mixed in the refrigerant, so that the expansion valve can continue to operate properly.

According to the cooling device of the second aspect of the present invention, by installing the refrigerant container close to the expansion valve,
The refrigerant passage that connects the inside of the refrigerant container and the second pressure chamber is shortened. Therefore, the effect of delaying the pressure transmission by the refrigerant container is not affected by the refrigerant flow passage, and thus works better in the second pressure chamber.

[0012]

Embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 shows an embodiment in which the cooling device of the present invention is applied to a vehicle cooling device. The refrigeration cycle of the cooling device includes a compressor 1, a condenser 2, a receiver 3, an expansion valve 4 and an evaporator 5, and the refrigerant circulates in the refrigeration cycle together with lubricating oil. A heat sensitive tube 6 is attached to the outlet side pipe of the evaporator 5.

Since the drive shaft (not shown) of the compressor 1 is connected to the crankshaft of the engine (not shown) by a belt and rotates together with the crankshaft, the refrigerant supplied from the compressor 1 when the running condition of the vehicle is substantially constant. The pressure of is almost constant. The expansion valve 4 is an external pressure equalizing type, and an inlet flow path 12 and an outlet flow path 13 which can flow through the blowout hole 11a are formed in the housing 11. The high temperature and high pressure refrigerant is supplied from the receiver 3 to the inlet passage 12,
This refrigerant is discharged from the outlet passage 13 to the evaporator 5 through the blowout holes 11a. A valve seat 11b is formed on the inner wall of the housing 11 forming the blowout hole 11a. Inlet channel 1
2 is a ball 2 which is a valve member that can be seated on the valve seat 11b.
1, a guide member 22 that supports the ball 21, a compression coil spring 23 that is a biasing means that biases the guide member 22 toward the valve seat 11b, and is fixed to the inner wall of the housing 11 without blocking the inlet passage 12. A locking member 24 that locks the compression coil spring 23 is housed. The amount of the refrigerant blown from the blowout hole 11a to the outlet flow path 13 is determined by the valve seat 11b.
It is determined by the blowout opening area which is the flow passage area of the refrigerant formed between the ball 21 and the ball 21.

The case 30 is closely fitted to the outer wall of the housing 11. The diaphragm 31 made of stainless steel, which is an elastic thin film whose outer peripheral edge is sandwiched by the case 30,
The space in the case 30 is partitioned into a first pressure chamber 32 and a second pressure chamber 33. The pressure in the heat-sensitive cylinder 6 is applied to the first pressure chamber 32 via the refrigerant flow passage 40. In the second pressure chamber 33, the joint 42, the refrigerant container 43, and the external equalizing capillary 41, which is a part of the refrigerant pipe, pass through the refrigerant passage 14 formed in the housing 11 and then in the outlet side pipe of the evaporator 5. Refrigerant pressure is applied. The pressure in the first pressure chamber 32 acts to separate the ball 21 from the valve seat 11b to increase the blowout opening area, and the pressure in the second pressure chamber 33 brings the ball 21 closer to the valve seat 11b to reduce the blowout opening area. It works in the direction of shrinking. The refrigerant pipe including the outer capillary 41 connects the outlet side of the evaporator 5 to the inlet of the refrigerant passage 14 via the joint 42 and the refrigerant container 43, and has a smaller diameter than the refrigerant container 43. The outer uniform capillary 41 has a diameter of 1 mm, and the refrigerant container 43 has a diameter of 10 mm. A locking member 34 that moves together with the diaphragm 31 is adhered to the surface of the diaphragm 31 on the second pressure chamber 33 side. The rod 35, which is an actuating rod, is supported by a cylindrical guide member 36 fixed to the inner wall of the housing 11 so as to be capable of reciprocating, and is sealed at both ends of the guide member 36 by the O-ring 37 from the inner wall of the housing 11. There is. The rod 35 is inserted through the blowout hole 11a, one end of which abuts on the locking member 34, and the other end of which abuts on the ball 21. The diaphragm 31 is displaced by the force received from the difference between the pressure in the first pressure chamber 32 and the pressure in the second pressure chamber 33,
The blowing opening area is adjusted by reciprocally moving the rod 35 according to the displacement amount.

The heat-sensitive cylinder 6 is filled with the same gas as the refrigerant circulating in the refrigeration cycle, and the gas in the heat-sensitive cylinder 6 has a saturated pressure due to the temperature of the refrigerant on the outlet side of the evaporator 5. Therefore, the pressure in the heat-sensitive cylinder 6 changes depending on the refrigerant temperature on the outlet side of the evaporator 5, and this pressure is transmitted to the first pressure chamber 32 via the refrigerant flow passage 40. Next, the operation of the cooling device will be described along the refrigerant flow.

(1) The refrigerant compressed into a high-temperature and high-pressure gaseous state in the compressor 1 is cooled in the condenser 2 and liquefied. Receiver 3
Temporarily stores the liquefied refrigerant in the condenser 2 and supplies it to the expansion valve 4 in response to the cooling load. In the receiver 3,
Water and foreign substances mixed in the refrigerant are removed. (2) The diaphragm 31 of the expansion valve 4 receives the force of the pressure difference between the first pressure chamber 32 and the second pressure chamber 33 from the rod 3
5 is moved to change the blowout opening area formed by the valve seat 11b and the ball 21, so that the blowout hole 11a to the outlet flow path 13 are changed.
Adjust the amount of refrigerant flowing out to.

(3) The refrigerant discharged from the blow-out hole 11a through the outlet passage 13 into the low-pressure evaporator 5 becomes a mist-like low-temperature low-pressure refrigerant due to the adiabatic expansion action, and the refrigerant and the air in the passenger compartment are separated from each other. By exchanging heat between them, the air in the vehicle interior is cooled. The refrigerant that has exchanged heat with the air in the passenger compartment becomes a set superheated gas, and the compressor 1 is discharged from the outlet side pipe of the evaporator 5.
Is returned to. The heat-sensitive cylinder 6 attached to the outlet side pipe of the evaporator 5 senses the temperature of the refrigerant in the outlet pipe, the pressure of the gas sealed in the heat-sensitive cylinder 6 changes, and this pressure changes to the first pressure chamber 32.
Join. The refrigerant pressure in the outlet side pipe of the evaporator 5 is applied to the second pressure chamber 33 from the refrigerant passage 14 through the joint 42, the refrigerant container 43, and the outer uniforming capillary 41.

Next, the operation of the refrigerant device with respect to high and low vehicle interior temperature will be described. (1) When the temperature in the passenger compartment is high, the atomized refrigerant in the evaporator 5 is completely evaporated upstream of the normal evaporation completion point. Therefore, the temperature of the superheated gas of the refrigerant on the outlet side of the evaporator 5 rises and the pressure in the heat-sensitive cylinder 6 rises, so that the diaphragm 31 moves downward in FIG. Then, since the ball 21 is pushed by the rod 35 and moves away from the valve seat 11b, the blowout opening area increases, so that the amount of refrigerant discharged from the outlet passage 13 into the evaporator 5 increases. As a result, the cooling capacity is increased, and the vehicle compartment temperature is decreased.

(2) When the temperature in the passenger compartment is low, the atomized refrigerant in the evaporator 5 is completely vaporized downstream from the normal vaporization completion point. Therefore, the temperature of the superheated gas of the refrigerant on the outlet side of the evaporator 5 decreases and the pressure inside the heat-sensitive cylinder 6 decreases, so that the diaphragm 31 moves upward in FIG. Then, the ball 21 approaches the valve seat 11b by the urging force of the compression coil spring 23, and the area of the blowout opening decreases, so that the amount of refrigerant discharged from the outlet passage 13 into the evaporator 5 decreases. As a result, the cooling capacity is reduced, and the vehicle compartment temperature is increased.

The air temperature in the passenger compartment is adjusted to a desired temperature by the operation of the cooling device described above. Here, for example, when the vehicle shifts down or kicks down, the engine speed sharply increases, so the speed of the compressor 1 also sharply increases. Therefore, the refrigerant suction amount of the compressor 1 increases and the refrigerant pressure in the outlet side pipe of the evaporator 5 sharply decreases.
Due to this decrease in the refrigerant pressure, the refrigerant temperature in the outlet side pipe of the evaporator 5 decreases, and the pressure in the heat-sensitive cylinder 6 decreases. Then, the pressure drop in the heat-sensitive cylinder 6 is caused by the first
It is transmitted to the pressure chamber 32.

However, the heat-sensitive cylinder 6 detects a decrease in the refrigerant temperature due to a sharp decrease in the refrigerant pressure in the outlet side pipe of the evaporator 5, and the pressure in the heat-sensitive cylinder 6 decreases following the decrease in the refrigerant temperature. There is a time delay before
The pressure in the pressure chamber 32 gradually decreases. Due to the sudden decrease in the refrigerant pressure in the refrigerant pressure in the outlet side pipe of the evaporator 5, the inside of the joint 42, the space 43a of the refrigerant container 43, the inside of the outer level capillary 41, the refrigerant passage toward the outlet side of the evaporator 5 side. The refrigerant moves in the order of 14, and the refrigerant in the second pressure chamber 33 flows out to the evaporator 5 side. The diameter of the refrigerant container 43 is larger than that of the refrigerant pipe including the external smoothing capillary 41, that is, the flow passage area is large and the capacity is large. Therefore, the refrigerant pipe 43 of the refrigerant container 43 suddenly transfers the refrigerant to the evaporator 5 side. Even if the refrigerant moves, the gaseous refrigerant in the refrigerant container 43 is slowly removed from the evaporator 5.
Since the refrigerant flows out to the side, the refrigerant also gently flows out from the second pressure chamber 33, and the pressure in the second pressure chamber 33 gradually decreases. For this reason, the rapid decrease in the refrigerant pressure in the outlet side pipe of the evaporator 5 causes a time delay due to the heat-sensitive cylinder 6, and
Even if it is transmitted to the pressure chamber 32, the rapid decrease in the refrigerant pressure in the outlet side pipe of the evaporator 5 is transmitted to the second pressure chamber 33 with a time delay. Therefore, the pressure difference between the first pressure chamber 32 and the second pressure chamber 33 changes gently, so that the diaphragm 31 moves down gently. Since the pressure in the second pressure chamber 33 does not suddenly decrease, the diaphragm 31 quickly descends downward in FIG. 1 to increase the blowout opening area and discharge more refrigerant than necessary from the outlet passage 13 to the evaporator 5. Can be prevented. As a result, it is possible to prevent a large amount of the discharged refrigerant from being sucked and compressed in the compressor 1 in a liquid state without being vaporized in the evaporator 5, so that malfunction of the compressor 1 can be reduced.

The above-described action of delaying the pressure transmission by the refrigerant container 43 also acts when the refrigerant pressure in the outlet side pipe of the evaporator 5 rapidly increases. For example, when the refrigerant intake amount of the compressor 1 decreases due to a rapid decrease in the engine speed that occurs when the vehicle is upshifted, the refrigerant pressure in the outlet side pipe of the evaporator 5 rapidly increases and the refrigerant temperature also increases. Detecting this temperature rise, heat sensitive tube 6
Since there is a time delay even when the internal pressure increases, the pressure in the first pressure chamber increases with a delay. Further, when the refrigerant pressure rises rapidly in the outlet side pipe of the evaporator 5, the refrigerant container 4
Since the refrigerant gently flows from the third pressure chamber 33 toward the second pressure chamber 33, the pressure in the second pressure chamber 33 gradually increases. As a result, the pressure in the second pressure chamber 33 rapidly rises faster than the pressure in the first pressure chamber 32, the area of the outlet opening decreases, and the amount of refrigerant discharged to the evaporator 5 sharply decreases. It is possible to prevent problems such as a shortage of the amount of lubricating oil supplied to the compressor 1 and an increase in the temperature of blown air due to a decrease in the amount of heat exchange refrigerant in the evaporator 5.

Further, in the steady operation in which the vehicle traveling state hardly changes, the delay effect of the pressure transmission to the second pressure chamber 33 by the refrigerant container 43 is caused even if a slight pressure fluctuation occurs at the outlet side of the evaporator 5. Since it works to keep the amount of refrigerant discharged to the evaporator 5 at a substantially constant amount, stable operation of the cooling device can be maintained. The effect of delaying the pressure transmission by the refrigerant container 43 varies depending on the diameter and length of the refrigerant pipe including the outer uniforming capillary 41 and the volume of the refrigerant container 43. For example, if the diameter of the outer uniforming capillary 41 is increased or the length thereof is decreased, pressure transmission becomes faster. Further, when the volume of the refrigerant container 43 increases, the pressure change of the evaporator 5 becomes more gradual.
It is transmitted to the pressure chamber 33.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment in which a cooling device of the present invention is applied to a vehicle cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Condenser 4 Expansion valve 5 Evaporator 6 Heat-sensitive cylinder 11 Housing 12 Inlet channel 13 Outlet channel 11a Blow-out hole 11b Valve seat 21 Ball 23 Compression coil spring (biasing means) 31 Diaphragm (thin film) 32 First pressure chamber 33 Second pressure chamber 35 Rod (actuating rod) 41 Outer level capillary (refrigerant pipe) 43 Refrigerant container 43a Space portion

Claims (3)

[Claims] 1. An expansion valve for discharging refrigerant flowing from an inlet flow path to an outlet flow path through a throttle and discharging the refrigerant from the outlet flow path to an evaporator, the expansion valve being mounted on an outlet side pipe of the evaporator. The first pressure chamber to which the pressure in the thermosensitive cylinder that changes according to the temperature of the refrigerant in the outlet side pipe is applied and the second pressure chamber to which the pressure in the outlet side pipe is applied are separated from each other.
A thin film that is displaced according to the pressure difference between the pressure chamber and the second pressure chamber, and the opening area of the diaphragm is changed according to the amount of displacement of the thin film, so that the inlet channel and the outlet channel pass through the diaphragm. An expansion valve having a variable throttle means for adjusting the amount of refrigerant to be blown out to, and a refrigerant pipe forming a refrigerant flow passage communicating the inside of the outlet side pipe and the second pressure chamber, And a refrigerant container having a space portion having a large diameter and forming a part of the refrigerant flow path. 2. The variable throttle means forms an actuating rod that reciprocates with the displacement of the thin film, an outlet hole formed downstream of the refrigerant following the throttle and through which the actuating rod is inserted, and the inlet flow. A valve seat provided on the side of the inlet flow path of a partition wall that separates the passage from the outlet flow path, and the valve seat that is housed in the inlet flow path and forms the throttle and contacts the operating rod and the valve seat side. The cooling device according to claim 1, further comprising a valve member and a biasing unit that biases the valve member toward the valve seat. 3. The cooling device according to claim 1, wherein the refrigerant container is installed close to the expansion valve.