JP2001153496A - Expansion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely supply a refrigerant to an evaporator even immediately after a compressor turns OFF and thereby to avoid a sudden rise of the temperature of the evaporator. SOLUTION: An orifice 33 making a high-pressure-side passage part 14 communicate with a low-pressure-side passage part 15 is provided apart from a communication passage 16. This orifice 33 is closed up by a closing part 35 of a movable member 34 when the communication passage 16 is opened. When a compressor 2 stops and a low-pressure line comes to be under high pressure, an operating rod 27 moves in the direction of the axis thereof and a valve disk 31 closes up the communication passage 16. At the same time, the valve disk 31 comes into contact with a valve seat 30 formed in the movable member 34 and presses the movable member 34. Therefore the movable member 34 moves in the direction of the axis of the operating rod 27 and the closing part 35 thereof detaches from the orifice 33. Then a refrigerant passes from the high-pressure-side passage part 14 to the low-pressure-side passage part 15 through the orifice 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an expansion device constituting a refrigeration cycle of an air conditioner used for, for example, a vehicle.

[0002]

2. Description of the Related Art Many conventional air conditioners control on / off of a compressor in order to achieve both freezing prevention of an evaporator and required cooling power.

That is, when the temperature of the evaporator or the temperature of the blown air immediately after the evaporator becomes higher than a predetermined temperature by an evaporator or a defrost thermostat attached immediately after the evaporator, a control signal for driving (ON) the compressor is output. Stop the compressor if it becomes possible (OF
F) to output a control signal to prevent freezing of the evaporator and to avoid insufficient cooling power of the evaporator. For this reason, if the heat load is small, the time until the temperature of the evaporator or the blowout temperature immediately after the evaporator reaches the temperature at which the compressor is turned on after the compressor is turned off becomes longer, and conversely, if the heat load is large,
Compressor turns on after compressor turns off
The time until it becomes shorter is set.

On the other hand, as an expansion device constituting a refrigeration cycle, a superheat is detected by using a temperature-sensitive cylinder as disclosed in, for example, Japanese Patent Application Laid-Open No. 4-366376. A non-electrically controlled expansion valve configured to obtain a temperature-dependent opening and closing may be used.

[0005]

However, when the above-mentioned non-electrically controlled expansion valve is used, when the compressor is turned off, the suction of the compressor is stopped immediately after that, and the pressure in the low pressure line gradually decreases. When the compressor is in the ON state, the pressure balance acting on the diaphragm is lost, and the expansion valve attempts to close.

For this reason, the refrigerant is not supplied to the evaporator immediately after the compressor is turned off.
Since the temperature of the evaporator rises rapidly and the temperature of the evaporator or the temperature of the blown air immediately after the evaporator reaches a predetermined temperature or more in a short time, a control signal for turning on the compressor is output. Time / (compressor ON time + compressor OFF time)) increases. As a result, when the power of the compressor is obtained from the engine, there is a problem that fuel efficiency is deteriorated. In addition, since the temperature of the air supplied into the passenger compartment also increases due to the rapid rise in the temperature of the evaporator, there is a possibility that conditioned air of a desired abnormal temperature is supplied to the occupant, which may cause discomfort to the crew.

[0007] Therefore, the present invention relates to a compressor of OF
It is an object of the present invention to provide an expansion device capable of reliably supplying the refrigerant to the evaporator even immediately after the temperature becomes F and avoiding a rapid rise in the temperature of the evaporator.

[0008]

SUMMARY OF THE INVENTION An expansion device according to the present invention is connected to a compressor, a condenser and an evaporator as appropriate to form a refrigeration cycle, and a high-pressure refrigerant into which refrigerant condensed by the condenser flows. A side passage portion, a low-pressure side passage portion for supplying a refrigerant to the evaporator is formed, and a decompression means for a refrigerant for decompressing the refrigerant flowing from the high-pressure side passage portion to the low-pressure side passage portion; A refrigerant leaking means is provided for enabling the refrigerant to flow from the high-pressure side passage to the low-pressure side passage even when the means is not functioning (claim 1). The refrigerant pressure reducing means includes a communication passage communicating the high-pressure passage and the low-pressure passage, an operating rod sliding hole formed through the communication passage, and an operating rod slide. An operating rod, which is disposed in a moving hole and moves in the axial direction according to the temperature of the evaporator or the blowing temperature immediately after the evaporator, and a valve body having a valve body at the tip thereof, and a valve body of the operating rod being constantly placed on the communication path side. It comprises a pressing mechanism for pressing and a valve seat formed at an opening portion of the communication passage on the valve body side, and in a state where the pressure reducing means of the refrigerant is functioning, the valve body separates from the valve seat and moves through the communication passage. When the valve is opened and the pressure reducing means for the refrigerant is not functioning, the valve body contacts the valve seat to close the communication passage (claim 2).

As described above, since the refrigerant pressure reducing means and the refrigerant leaking means are integrally provided in one expansion device, the expansion device including only the refrigerant pressure reduction device and the expansion device are closed. In the case of a separate unit and a device equipped with a refrigerant leak means that leaks the refrigerant to the evaporator when,
As compared with a configuration using a valve for stopping the leakage of the refrigerant when the expansion device is opened, the manufacturing process is simplified and the valve is not required, so that the manufacturing cost can be reduced. In addition, since piping between the expansion device and the device having the refrigerant leak means is not required, the operation can be simplified and the installation area can be reduced in space. In addition, the same refrigerant pressure reduction effect as that of the conventional expansion device can be obtained by the refrigerant pressure reducing means according to the second aspect.

The refrigerant leakage means includes an orifice hole communicating the high-pressure side passage portion and the low-pressure side passage portion, and a closing portion disposed to be movable in an axial direction of the orifice hole and closing the orifice hole. And a further pressing mechanism that constantly presses the movable member in the direction of the orifice hole, and the movable member is pressed by the other pressing mechanism in a state where the refrigerant pressure reducing means is functioning. The closing part closes the orifice hole by being performed,
In a state where the pressure reducing means of the refrigerant is not functioning, a structure in which the closing portion is separated from the orifice hole by pressing from a direction opposite to a direction pressed by the other pressing mechanism is specifically exemplified (claim). Item 3).

With such a configuration, when the compressor is stopped by ON / OFF control of the compressor, the operating rod moves in the axial direction and the valve body closes the communication passage. Since the valve body contacts the valve seat formed on the movable member and presses the movable member, the movable member moves in the axial direction of the operating rod, and the closed portion thereof separates from the orifice hole to open the orifice hole. Become. For this reason, even after the compressor is stopped, the high-pressure liquid refrigerant confined between the refrigerant pressure reducing means and the condenser is reliably passed from the high-pressure side passage to the low-pressure side passage through the orifice hole. It is possible to maintain the cooling power and form a state where the compressor is operating. Therefore, it is possible to reduce the operation rate of the compressor by increasing the time until the temperature of the evaporator reaches the temperature at which the compressor is turned on (compressor OFF time). Further, since a rapid rise in the temperature of the evaporator is suppressed, it is possible to prevent the temperature of the conditioned air supplied into the vehicle compartment from becoming unnecessarily high.

[0012] The refrigerant leaking means may include a storage space extending axially from the high-pressure side passage downstream of the high-pressure side passage, and an orifice hole communicating the storage space with the low-pressure side passage. A movable member housed in the housing space and having at least a first through hole communicating with the high pressure side passage portion and a second through hole extending from the first through hole to the orifice hole side; The movable member is configured such that the second through-hole is not communicated with the low-pressure side passage portion when the refrigerant pressure reducing means is functioning. In a state where the pressure reducing means of the refrigerant is not functioning, a structure in which the second through hole is moved to a position communicating with the orifice hole by pressing from the high pressure side passage portion side is specifically exemplified. (Claim 4).

With this configuration, when the compressor is stopped by ON / OFF control of the compressor, the operating rod moves in the axial direction so that the valve body closes the communication passage and the high pressure The movable member moves to a position where the second through hole communicates with the orifice hole against the pressure from the second pressing mechanism due to the high pressure of the refrigerant flowing in the side passage portion. Therefore, even after the compressor is stopped, the high-pressure liquid-phase refrigerant confined between the refrigerant pressure-reducing means and the condenser is reliably passed from the high-pressure side passage to the low-pressure side passage through the storage space and the orifice hole. Therefore, it is possible to maintain the cooling power of the evaporator and form a state where the compressor is operating. Therefore, it is possible to reduce the operation rate of the compressor by increasing the time until the temperature of the evaporator reaches the temperature at which the compressor is turned on (compressor OFF time).
Further, since a rapid rise in the temperature of the evaporator is suppressed, it is possible to prevent the temperature of the air supplied into the vehicle compartment from becoming unnecessarily high.

[0014] Further, the refrigerant leakage means may be a concrete structure having an orifice hole formed in the valve body of the operating rod in the axial direction of the operating rod (claim 5).

With this configuration, when the compressor is stopped by ON / OFF control of the compressor, the operating rod moves in the axial direction and the valve body closes the communication passage. Even after the compressor is stopped by the orifice hole provided in the body, the high-pressure liquid-phase refrigerant confined between the refrigerant pressure-reducing means and the condenser is reliably passed from the high-pressure side passage to the low-pressure side passage. , And it is possible to form a state where the compressor is operating. Therefore, it is possible to reduce the operation rate of the compressor by increasing the time until the temperature of the evaporator reaches the temperature at which the compressor is turned on (compressor OFF time).
Further, since a rapid rise in the temperature of the evaporator is suppressed, it is possible to prevent the temperature of the air supplied into the vehicle compartment from becoming unnecessarily high.

[0016] Further, the refrigerant leaking means includes an orifice hole communicating the high-pressure side passage portion and the low-pressure side passage portion, and a link mechanism having a closing member formed at the end thereof for closing the orifice hole. The link mechanism closes the orifice hole with the closing member in a state in which the refrigerant pressure reducing means is functioning, and closes the orifice in a state in which the refrigerant pressure reducing means is not functioning. A specific example is a structure in which the orifice hole is opened by moving in the axial direction of the hole (claim 6).
The link mechanism is connected to the operating rod in a passage portion on a side opposite to the side having the valve body with respect to the communication path, and moves integrally in the axial direction of the operating rod, and the closing member is configured to move the orifice. A link rod extending in the hole direction is provided at an end of the link rod (Claim 7), and the operating rod is connected to the operating rod at a passage portion on the same side as the side having the valve body with respect to the communication path. Move integrally in the axial direction of
There is one in which the closing member is provided at the tip of a link rod inserted through the orifice hole (claim 8).

With such a configuration, when the compressor is stopped by ON / OFF control of the compressor, the operating rod moves in the axial direction to close the communication passage with the valve body, and at the same time, the operating rod moves. The link mechanism moves integrally with the rod to move the closing portion away from the orifice hole and open the orifice hole. Therefore, even after the compressor is stopped, the high-pressure liquid-phase refrigerant confined between the refrigerant pressure-reducing means and the condenser is reliably passed from the high-pressure passage to the low-pressure passage through the orifice hole. , And it is possible to form a state where the compressor is operating. Therefore, it is possible to reduce the operation rate of the compressor by increasing the time until the temperature of the evaporator reaches the temperature at which the compressor is turned on (compressor OFF time). Further, since a rapid rise in the temperature of the evaporator is suppressed, it is possible to prevent the temperature of the air supplied into the vehicle compartment from becoming unnecessarily high.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the configuration of an air conditioner used for a vehicle. The air conditioner for a vehicle includes a compressor 2 which rotates by receiving power from an engine 1 and a compressor 2 which rotates. An electric clutch 3 provided on the power transmission 2 for interrupting transmission of power from the engine 1;
A condenser 4 for radiating the high-temperature and high-pressure refrigerant compressed by the compressor 2; a receiver for storing the refrigerant condensed and liquefied by the condenser 4, separating the gas-phase refrigerant and the liquid-phase refrigerant, and sending only the liquid-phase refrigerant to the downstream side Tank 5
And an expansion device 6 that decompresses the liquid-phase refrigerant sent from the receiver tank 5 into a low-temperature and low-pressure gas-liquid mixed refrigerant, and an evaporator 7 that evaporates and vaporizes the low-temperature and low-pressure gas-liquid mixed refrigerant sent from the expansion device 6 And a refrigeration cycle 8 in which pipes are joined in this order. In this refrigeration cycle 8,
A path from the discharge side of the compressor 3 to the expansion device 6 via the condenser 4 and the receiver tank 5 is connected to a high-pressure line 8A.
The path from the outflow side of the expansion device 6 to the suction side of the compressor 3 via the evaporator 7 is a low-pressure line 8B.

In FIG. 1, reference numeral 9 denotes an indoor temperature sensor for detecting the temperature in the passenger compartment, reference numeral 10 denotes a manual setting device for setting an air-conditioning state, and reference numeral 11 denotes the temperature of the evaporator 6 or the temperature after passing through the evaporator 6. The sensor is a temperature sensor immediately after the evaporation, which detects the air temperature immediately after. The signals from the sensors 9 and 11 and the setting device 10 are input to the control unit 12. Here, the control unit 12 includes a central processing unit (CPU) (not shown) and a read-only memory (RO).
M), a random access memory (RAM), an input port (I / O), and the like.
It has a drive circuit for controlling OFF and the like.
Various input signals are processed according to a predetermined program given to M, and ON / OFF of the compressor 2 and the like are controlled.

Here, the ON / OFF control of the compressor 2 during the operation of the refrigeration cycle 8 means that the temperature of the evaporator 7 or the air temperature immediately after passing through the evaporator 7 is determined by the need to prevent freezing of the evaporator 7. When the temperature becomes lower than the stop reference temperature required to avoid the freezing of 7, the electric clutch 3 is turned off,
Cut off the transmission of power from Engine 1 to Compressor 2,
When the temperature of the evaporator 7 rises after the compressor 2 stops and becomes higher than the reference operating temperature α (for example, 10 ° C.) required to maintain the cooling power of the evaporator 7, the electric clutch 3 is turned on. This is control for transmitting power from the engine 1 to the compressor 2.

The above-described expansion device 6 is sensitive to the refrigerant temperature and the refrigerant pressure in the high-pressure line 8A, and responds to the refrigerant temperature and the refrigerant pressure in the high-pressure line 8A and the low-pressure line 8B.
A communication path 16, a temperature sensing section 20, and an operating rod 27 are provided as pressure reducing means for the refrigerant for adjusting the communication state between the high pressure line 8A and the low pressure line 8B by the pressure reducing means. The orifice hole 33 serves as a means for leaking refrigerant that leaks refrigerant from 8A to the low-pressure line 8B.
It has a movable member 34, and FIG. 2 shows a specific configuration example thereof.

A main body 13 made of aluminum or the like, which is a main component of the expansion device 6, is connected to a high-pressure line 8A piping and communicates with the condenser 4 side. Low pressure side passage portion 15 which is connected to a pipe communicating with the evaporator 7 and communicates with the evaporator 7 side
And an inflow-side passage portion 17 to the evaporator 7 comprising a communication passage 16 communicating the high-pressure side passage portion 14 and the low-pressure side passage portion 15, and a pipe having one end connected to the outlet side of the evaporator 7, And an outflow side passage portion 18 from the evaporator 7 connected to a pipe leading to the receiver tank 5.

The high-pressure side passage portion 14 is composed of a relay space 14a drilled from the radial direction of the passage portion of the main body portion 13 and a connecting portion 14b connected to the relay space and a pipe. Is closed by fitting a lid 19. Further, the low-pressure side passage portion 15 has a connection portion 15a that connects to a pipe from the evaporator 7. On the other hand, the outflow-side passage portion 18 is a portion through which the low-pressure gas-phase refrigerant flows from the evaporator 7.
Connection part 18a that connects to piping from the receiver tank 5
And a connecting portion 18b that connects to the piping from the outside.

The temperature sensing section 20 is a device for extracting a change in mechanical position according to the temperature or pressure of the low-pressure gas-phase refrigerant flowing in the outflow side passage section 18, and is formed of an upper portion of the housing 21 and thin stainless steel. It has a diaphragm chamber 23 surrounded by the diaphragm 22, a pressure equalizing chamber 24 surrounded by the diaphragm 22 and the lower side of the housing 21, and a temperature sensing rod 25.

A pipe 26 is connected to the upper part of the diaphragm chamber 23, and a gas-phase refrigerant corresponding to a temperature change is filled in the diaphragm chamber 23 through the pipe 26 in a saturated state. Further, the pressure equalizing chamber 24 communicates with the outflow side passage 18 so that a part of the refrigerant flows therein. Further, the temperature sensing rod 25 is provided in the outflow side passage 18 and is used for electrically driving the heat of the refrigerant flowing in the outflow side passage portion 18 to the gasified refrigerant in the diaphragm chamber 23. Is provided with an operating rod 27 integrally therewith.

The operating rod 27 is disposed in an operating rod sliding hole 28 which intersects the inflow side passage portion 17 in a direction substantially perpendicular to the inflow side passage portion 17, and an O-ring 29 is mounted on the temperature sensing rod 25 side.
The airtightness with the operating rod sliding hole 28 is maintained, and the distal end side thereof penetrates the low-pressure side passage portion 15 in the radial direction.
Further, it reaches the inside of the high-pressure side passage portion 16 through the communication passage 16. The end of the operating rod 27 is connected to the communication passage 1.
6, a valve seat 30 arranged on the periphery of the opening on the high-pressure side passage portion 14 side
, A spherical valve element 31 is provided. The valve body 31 has a valve body receiver 31a attached below the valve body 31. An elastic member 32 such as a spring is disposed between the valve body receiver 31a and the lid 19, so that the valve body 31 is a valve. It is in a state of being constantly pressed to the seat 30 side.

By the way, in the expansion device 6 according to the present invention,
As shown in FIG. 3, an orifice hole 33 that connects the high-pressure side passage portion 14 and the low-pressure side passage portion 15 is formed in parallel with the communication passage 16, and a portion near the valve seat 30 is a main body portion. A movable member 34 is provided separately from the movable member 13.
The movable member 34 has a closing portion 35 for closing the orifice hole 33, and is movable in the axial direction of the operating rod 27 by being externally inserted into the operating rod 27. Since the elastic member 36 such as a spring is disposed between the movable member 34 and the low-pressure side passage portion 15, the movable member 34 is constantly pressed toward the high-pressure side passage portion 14.

In the expansion device 6 having the above-described structure, when the refrigerant flowing out of the evaporator 7 passes through the outflow-side passage portion 18, the temperature of the refrigerant is transmitted to the refrigerant in the diaphragm chamber 23 via the temperature sensing portion 20. The volume of the diaphragm chamber 23 is changed so as to correspond to the refrigerant temperature, whereby the diaphragm 22 is displaced. Further, since the refrigerant pressure is also guided to the pressure equalizing chamber 24, the diaphragm 22 is also displaced in accordance with the fluctuation of the refrigerant pressure, and the position of the diaphragm 22 is adjusted by the temperature and the pressure of these refrigerants. The opening degree of the communication passage 16 is adjusted by the valve element 31 connected thereto, and the opening degree of the expansion device is adjusted by the fluctuation of the superheat degree of the refrigerant in the outflow-side passage section 18 to keep the superheat degree constant. It is designed to drip.

In particular, in such an expansion device 6,
When the compressor 2 stops, the suction of the low-pressure refrigerant by the compressor 2 is stopped, so that the pressure in the low-pressure line 8B gradually increases, and accordingly, the pressure in the equalizing chamber 24 communicating with the outflow-side passage portion 18 also increases. . Then, FIG.
The position of the diaphragm 22, which has been balanced in the state shown in FIG. 3, is displaced in the direction in which the valve body 31 is seated on the valve seat 30, so that the communication path 16 is closed and
1 abuts against the valve seat 30 and presses the movable member 30;
As shown in FIG. 3B, the movable member 34 is
7 moves in the axial direction to close the orifice hole 3.
3 and the orifice hole 33 is opened.
When the pressure of the low-pressure line 8B returns to the normal state, the communication path 16 is opened as shown in FIG. 3A through a process opposite to the above-described process, and the orifice hole 33 is moved to the movable member. 30 is closed by the closing portion 35.

Therefore, even if the communication passage 16 is closed immediately after the compressor 2 stops and the refrigerant stops flowing from the high-pressure passage portion 14 to the low-pressure passage portion 15 through the communication passage 16, the refrigerant passes through the orifice hole 33 to the evaporator 7. The refrigerant can be supplied reliably.

When the above situation is plotted on the time axis on the horizontal axis and the temperature change of the passing air immediately after the evaporator on the vertical axis, as shown in FIG. 3, the conventional refrigeration shown by a broken line without the orifice hole 33 is shown. According to the refrigeration cycle 8 of the present invention, the refrigerant flows through the orifice hole 33 when the valve body 31 is closed, so that the high pressure between the condenser 4 and the expansion valve 6 is maintained even after the compressor 2 is stopped. By flowing the refrigerant into the evaporator 7 side, the cooling power of the evaporator 7 is maintained, and it is possible to form a state where the compressor 2 is operating. For this reason, the temperature rise of the passing air immediately after the evaporator 7 after the compressor 2 is turned off (solid line in FIG. 4) is slower than the temperature rise of the passing air immediately after the evaporator in the conventional refrigeration cycle (dashed line in FIG. 4). Therefore, when the operating reference temperature of the compressor 2 is set to the predetermined temperature α, the time t2 from the OFF to the ON of the compressor 2 is longer than the time t1 from the OFF to the ON of the conventional compressor. Therefore, the operation rate of the compressor 2 can be reduced. The temperature rise of the passing air immediately after the evaporator 7 (solid line in FIG. 4) is caused by the temperature rise of the passing air immediately after the evaporator in the conventional refrigeration cycle (dashed line in FIG. 4).
Since the temperature of the air becomes gentler, the temperature of the air supplied into the vehicle compartment can be prevented from increasing.

In the above description, FIGS.
Although 14 is a high-pressure side passage portion and 15 is a low-pressure side passage portion, the present invention is not limited to this. The configuration of the refrigerant decompression means such as the communication path 16 and the refrigerant leak means such as the movable member 34 described above. 2 and 3, the flow path of the refrigerant shown in FIGS. 2 and 3 is reversed, and 14 is a low-pressure side passage, 15
May be used as the high-pressure side passage.

FIG. 5 shows another embodiment of the expansion device 6 according to the present invention. In the expansion device 6, reference numeral 15 denotes a high-pressure side passage portion, and reference numeral 14 denotes a low-pressure side passage portion. The expansion device 6 shown is one in which the flow of the refrigerant is in the opposite direction. Hereinafter, the expansion device 6 shown in FIG. 5 will be described. However, the same portions appearing in the drawings are denoted by the same reference numerals and the description thereof is omitted.

In the expansion device 6, a storage space 37 is formed in the axially deep side of the high-pressure side passage portion 15, and a connection portion 1 of the low-pressure side passage portion 14 is formed from the storage space 37.
A communication path 38 extending to a portion near the 4b side is formed, and a movable member 39 is disposed in the storage space 37. The movable member 39 has a first through-hole 40 communicating with the high-pressure side passage portion 15 therein, and a first through-hole 40.
And a second through-hole 41 which intersects at right angles to the second passage hole 41 is formed in a substantially T-shape.
5 is constantly pressed. However, the biasing force of the elastic member 42 against the movable member 39 is such that when the communication passage 16 is opened, the second through hole 41 is higher than the communication passage 38 on the high pressure side passage portion 15.
It is adjusted to be located on the side.

In the expansion device 6 having the above-described structure, similarly to the previous embodiment, when the refrigerant flowing out of the evaporator 7 passes through the outflow-side passage portion 18, the temperature of the refrigerant is changed via the temperature-sensitive portion 20 to the diaphragm. The refrigerant is transmitted to the refrigerant in the chamber 23, and the volume of the diaphragm chamber 23 is changed to match the refrigerant temperature, whereby the diaphragm 22 is displaced. Further, since the refrigerant pressure is also guided to the pressure equalizing chamber 24, the diaphragm 22 is also displaced in accordance with the fluctuation of the refrigerant pressure, and the position of the diaphragm 22 is adjusted by the temperature and the pressure of these refrigerants. The opening degree of the communication passage 16 is adjusted by the valve element 31 connected thereto, and the opening degree of the expansion device is adjusted by the fluctuation of the superheat degree of the refrigerant in the outflow-side passage section 18 to keep the superheat degree constant. It is designed to drip.

In the expansion device 6 as well, when the compressor 2 is stopped, the suction of the low-pressure refrigerant by the compressor 2 stops, so that the pressure of the low-pressure line 8B gradually increases, and accordingly, the outflow-side passage portion 18 The pressure in the pressure equalizing chamber 24 communicating with the pressure also increases. Then, FIG.
The position of the balanced diaphragm 22 in the state shown in (a) is displaced in the direction in which the valve element 31 is seated on the valve seat 30, so that the communication path 16 is closed, and at the same time, the movable member 39 is 5B, the second through hole 41 and the communication passage 38 coincide with each other, as shown in FIG. 5B.
The high pressure side passage portion 15 and the portion near the connection portion 14b of the low pressure side flow passage portion 14 are connected to the first through hole 40, the second through hole 41, and the communication passage 38.
And the communication is established via When the pressure of the low-pressure line 8B returns to the normal state, the communication path 16 is opened as shown in FIG. 42 moves toward the high pressure passage portion 14 by the urging force of the communication passage 38 and the movable member 3.
9 and the second through hole 41 are not communicated.

Therefore, even if the communication passage 16 is closed immediately after the compressor 2 is stopped and the refrigerant stops flowing from the high-pressure passage portion 15 to the low-pressure passage portion 14 through the communication passage 16, the first passage of the movable member 39 is stopped. Since it is possible to reliably supply the refrigerant to the evaporator 7 through the hole 40, the second through hole 41, and the communication path 38, the operation and effect shown in the characteristic diagram of FIG. Obtainable.

FIG. 6 shows still another embodiment of the expansion device 6 according to the present invention. In this expansion device 6, even if 15 is a high-pressure side passage portion and 14 is a low-pressure side passage portion, the opposite is true. Although 14 may be a high-pressure side passage portion and 15 may be a high-pressure side passage portion, hereinafter, 14 is a high-pressure side passage portion and 15 is a high-pressure side passage portion in accordance with the arrows indicating the flow of the refrigerant in FIG. explain. However, the same portions appearing in the drawings are denoted by the same reference numerals and the description thereof is omitted.

The basic configuration of the expansion device 6 is the same as that of the conventional expansion device.
An orifice hole 43 extending in the axial direction of the operating rod 27 is formed at 1. Although only one orifice hole 43 is shown in the drawing, the number is not particularly limited. The contact area of the valve body receiver 31a with the valve body 31 is as follows:
The orifice hole 43 of the valve element 31 is so small that it is not closed by the valve element receiver 31a.

In the expansion device 6 having the above-described structure, similarly to the above-described embodiments, when the refrigerant flowing out of the evaporator 7 passes through the outflow-side passage portion 18, the temperature of the refrigerant passes through the temperature sensing portion 20. The refrigerant is transmitted to the refrigerant in the diaphragm chamber 23 through the diaphragm chamber 23, and the volume of the diaphragm chamber 23 is changed so as to correspond to the refrigerant temperature, whereby the diaphragm 22 is displaced. Further, since the refrigerant pressure is also guided to the pressure equalizing chamber 24, the diaphragm 22 is also displaced in accordance with the fluctuation of the refrigerant pressure, and the position of the diaphragm 22 is adjusted by the temperature and the pressure of these refrigerants. The opening degree of the communication passage 16 is adjusted by the valve element 31 connected thereto, and the opening degree of the expansion device is adjusted by the fluctuation of the superheat degree of the refrigerant in the outflow-side passage section 18 to keep the superheat degree constant. It is designed to drip.

In the expansion device 6 as well, when the compressor 2 is stopped, the suction of the low-pressure refrigerant by the compressor 2 is stopped, so that the pressure of the low-pressure line 8B gradually increases, and accordingly, the outflow-side passage portion 18 The pressure in the pressure equalizing chamber 24 communicating with the pressure also increases. Then, FIG.
Since the position of the balanced diaphragm 22 shown in (a) is displaced in the direction in which the valve body 31 is seated on the valve seat 30, the communication path 16 is closed as shown in FIG. 6 (b). The high-pressure passage portion 15 and the low-pressure passage portion 14 are in communication with each other via the orifice hole 43 of the valve element 31.

Therefore, even if the valve 31 closes the communication passage 16 immediately after the compressor 2 stops, the valve 31
Through the orifice hole 43 formed in the evaporator 7
4 can be reliably supplied, so that the operation and effect shown by the characteristic diagram in FIG. 4 can be obtained similarly to the previous embodiment.

The configuration of the inflation device 6 shown in FIGS. 7 and 8 uses a link mechanism 44 instead of closing the orifice hole 33 with the closing portion 35 of the movable member 34 in the embodiment shown in FIGS. The orifice hole 33 is to be closed. However, the same portions appearing in the drawings are denoted by the same reference numerals and the description thereof is omitted.

The link mechanism 44 shown in FIG.
More specifically, 14 is a high-pressure side passage portion, 15 is a low-pressure side passage portion, and the other end of the link rod 45 having one end connected to the operating rod 27 and one end of the link rod 47 are connected to the pin 4.
6 and an end of the link bar 47 opposite to the link bar 45 and one end of the link bar 49 are connected by a pin 48, and a spherical closing member 50 is provided at an end of the link bar 49 opposite to the link bar 45. It is composed of The link rod 45
The link bar 47 is connected to the operating rod 27 so as to be always vertical.
From the position perpendicular to the valve body 31 side. The link rod 49 is suspended from the pin 48, and can rotate about the pin 48 as an axis. In this embodiment, the orifice hole 33
A guide portion 51 for guiding the closing member 50 to the opening of the orifice hole 33 is formed at the periphery of the opening.

In the expansion device 6 having the above-described structure, when the refrigerant flowing out of the evaporator 7 passes through the outflow-side passage portion 18, the temperature of the refrigerant is transmitted to the refrigerant in the diaphragm chamber 23 via the temperature sensing portion 20. The volume of the diaphragm chamber 23 is changed so as to correspond to the refrigerant temperature, whereby the diaphragm 22 is displaced. Further, since the refrigerant pressure is also guided to the pressure equalizing chamber 24, the diaphragm 22 is also displaced in accordance with the fluctuation of the refrigerant pressure, and the position of the diaphragm 22 is adjusted by the temperature and the pressure of these refrigerants. The opening degree of the communication passage 16 is adjusted by the valve element 31 connected thereto, and the opening degree of the expansion device is adjusted by the fluctuation of the superheat degree of the refrigerant in the outflow-side passage section 18 to keep the superheat degree constant. It is designed to drip.

In the expansion device 6 as well, when the compressor 2 stops, the suction of the low-pressure refrigerant by the compressor 2 is stopped, so that the pressure of the low-pressure line 8B gradually increases, and accordingly, the outflow-side passage portion 18 The pressure in the pressure equalizing chamber 24 communicating with the pressure also increases. Then, FIG.
Since the position of the balanced diaphragm 22 shown in (a) is displaced in the direction in which the valve element 31 is seated on the valve seat 30, the communication path 16 is closed and at the same time the link rod 45 is closed.
Also moves toward the anti-orifice hole side, and the link rod 47 is rotated until the link rod 47 is perpendicular to the operating rod 27. As it moves to the orifice hole side, FIG.
As shown in (2), the closing member 50 climbs up the slope while sliding on the inclined surface of the guide portion 51, and the orifice hole 33 is opened.
When the pressure of the low pressure line 8B returns to the normal state, the operating rod 27 moves to the inside of the communication passage 16 and
With this, the closing member 50 descends while sliding on the inclined surface of the guide portion 51, and at the same time, the link rod 46 rotates toward the anti-orifice hole side, and the orifice hole 33 as shown in FIG. Close the opening of.

Therefore, even if the communication passage 16 is closed immediately after the compressor 2 stops and the refrigerant stops flowing from the high-pressure passage portion 14 to the low-pressure passage portion 15 through the communication passage 16, the refrigerant passes through the orifice hole 33 to the evaporator 7. Since it is possible to reliably supply the refrigerant, the operation and effect shown by the characteristic diagram in FIG. 4 can be obtained as in the previous embodiment.

On the other hand, the link mechanism 4 shown in FIG.
More specifically, 4 is a high-pressure side passage portion and 15 is a low-pressure side passage portion. The other end of the link rod 52 having one end connected to the valve body receiver 31a and one end of the link rod 54 are connected. The link rod 2 of the link rod 54 is connected with the pin 53.
4 is provided with a spherical closing member 50 at the opposite end. The link rod 52 is attached to the valve body receiver 31a so as to be perpendicular to the operation rod 27, the link rod 54 is inserted into the orifice hole 33 and moves in the axial direction of the orifice hole 33, and the closing member 50 It is located on the high-pressure side passage portion 15 side.

In the expansion device 6 having the above-described configuration, when the refrigerant flowing out of the evaporator 7 passes through the outflow-side passage portion 18, the temperature of the refrigerant is transmitted to the refrigerant in the diaphragm chamber 23 via the temperature sensing portion 20. The volume of the diaphragm chamber 23 is changed so as to correspond to the refrigerant temperature, whereby the diaphragm 22 is displaced. Further, since the refrigerant pressure is also guided to the pressure equalizing chamber 24, the diaphragm 22 is also displaced in accordance with the fluctuation of the refrigerant pressure, and the position of the diaphragm 22 is adjusted by the temperature and the pressure of these refrigerants. The opening degree of the communication passage 16 is adjusted by the valve element 31 connected thereto, and the opening degree of the expansion device is adjusted by the fluctuation of the superheat degree of the refrigerant in the outflow-side passage section 18 to keep the superheat degree constant. It is designed to drip.

In the expansion device 6 as well, when the compressor 2 stops, the suction of the low-pressure refrigerant by the compressor 2 stops, so that the pressure of the low-pressure line 8B gradually increases, and accordingly, the outflow-side passage portion 18 The pressure in the pressure equalizing chamber 24 communicating with the pressure also increases. Then, FIG.
Since the position of the balanced diaphragm 22 shown in (a) is displaced in the direction in which the valve element 31 is seated on the valve seat 30, when the communication path 16 is closed as shown in FIG. 8 (b). At the same time, the position of the link rod 52 also moves toward the communication passage 16, and accordingly, the link rod 54 is moved to the orifice hole 33.
8B, the closing member 50 is separated from the orifice hole 33 and the orifice hole 33 is opened, as shown in FIG. 8B. In addition, low pressure line 8
When the pressure of B returns to the normal state, the operation rod 27 moves to the inside of the communication passage 16 to open the communication passage 16 via the reverse path to the above description, so that the link rod is operated. 54 also moves to the low-pressure side passage portion 14 side, and the closing member 50 closes the opening of the orifice hole 33 as shown in FIG.

Therefore, even if the valve 31 closes the communication passage 16 immediately after the compressor 2 stops, this valve 31
Through the orifice hole 43 formed in the evaporator 7
4 can be reliably supplied, so that the operation and effect shown by the characteristic diagram in FIG. 4 can be obtained similarly to the previous embodiment.

Further, as described so far, the structure in which the refrigerant pressure reducing means and the refrigerant leaking means are integrally provided in one expansion device 6 makes it possible to provide an expansion device comprising only the refrigerant pressure reducing means. When the expansion device is closed, a device provided with a refrigerant leak unit that leaks refrigerant to the evaporator when the expansion device is closed is provided as a separate unit, and a configuration using a valve for stopping the refrigerant leakage when the expansion device is opened is provided. In comparison, the manufacturing process is simplified, and no valve is required. Further, piping between the expansion device and the device having the refrigerant leakage means is not required.

[0054]

As described above, according to the present invention, since the refrigerant decompression means and the refrigerant leak means are integrally provided in one expansion device, the expansion comprising only the refrigerant decompression means is provided. The device and a device having a means for leaking refrigerant that leaks refrigerant to the evaporator when the expansion device is closed are separate units, and a valve for stopping the leakage of the refrigerant when the expansion device is opened is used. Compared with the configuration, the manufacturing process is simplified, the valve is not required, and the number of parts is reduced, so that the manufacturing cost of the entire air conditioner can be reduced. Further, since piping between the expansion device and the device having the refrigerant leakage means is not required, the operation can be simplified and the installation area can be saved in space.

According to the present invention, even after the compressor is stopped, the high-pressure liquid refrigerant confined between the refrigerant decompression means and the condenser is reliably discharged from the high-pressure side passage through the communication passage or the communication hole. Since the evaporator is passed through the low-pressure side passage, the cooling power of the evaporator can be maintained, and it is possible to form a state in which the compressor is operating. Therefore, the stoppage time of the compressor is lengthened and the operating rate of the compressor is reduced. It is possible. Further, since a rapid rise in the temperature of the evaporator is suppressed, an increase in the temperature of the air supplied into the vehicle compartment is avoided. It is also possible to prevent the high-temperature conditioned air from being blown to the occupant to cause discomfort.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a refrigeration cycle using an expansion device according to the present invention.

FIG. 2 is a cross-sectional view of the expansion device according to the first embodiment.

FIG. 3A is an enlarged view of an essential part showing a state in which an orifice hole in the expansion device is opened and a communication passage is closed, and FIG. It is a principal part enlarged view which shows the state which opened the passage and closed the orifice hole.

FIG. 4 is a characteristic diagram showing that the operating time of the compressor is reduced due to an increase in the elapsed time from OFF to ON of the compressor in the expansion device.

FIG. 5 is a diagram showing a configuration in which the refrigerant flows from the high-pressure side passage to the low-pressure side passage when the orifice hole is closed as shown in FIGS. 2 and 3, and FIG. FIG. 4B is an enlarged view of a main part showing a state where the orifice hole in the expansion device is opened and the communication passage is closed, and FIG. 4B is a main part showing a state where the communication passage in the expansion device is opened and the orifice hole is closed. It is an enlarged view.

FIG. 6 is a diagram showing a configuration in which a refrigerant flows from a high-pressure side passage to a low-pressure side passage when an orifice hole is closed, which is different from the above two embodiments. FIG. FIG. 6B is an enlarged view of a main part showing a state where an orifice hole in the device is opened, and FIG. 6B is an enlarged view showing a state where the orifice hole in the expansion device is closed.

FIG. 7 is a diagram showing a configuration in which the refrigerant flows from the high-pressure side passage to the low-pressure side passage when the orifice hole is closed, which is different from the above-described three embodiments. FIG. FIG. 7B is an enlarged view of a main part showing a state where an orifice hole in the device is opened and a communication path is closed, and FIG. 7B is an enlarged view of a main part showing a state where the communication path in the expansion device is opened and the orifice hole is closed. FIG.

FIG. 8 is a view showing a configuration in which the refrigerant flows from the high-pressure side passage to the low-pressure side passage when the orifice hole is closed when the flow of the refrigerant is in the opposite direction to FIG. 7; )
FIG. 8B is an enlarged view of a main part showing a state in which the orifice hole in the expansion device is opened and the communication path is closed, and FIG.
It is a principal part enlarged view which shows the state which opened the communication path in the same expansion device, and closed the orifice hole.

[Explanation of symbols]

 2 Compressor 4 Condenser 5 Receiver tank 6 Expansion device 7 Evaporator 8 Refrigeration cycle 8A High pressure line 8B Low pressure line 11 Eva temperature sensor 14 High pressure side passage (low pressure side passage) 15 Low pressure side passage (low pressure side passage) 16 Communicating passage 27 Actuating rod 28 Actuating rod sliding hole 30 Valve seat 31 Valve element 32 Elastic member 33 Orifice hole 34 Movable member 35 Closure portion 36 Elastic member 37 Storage space 38 Communicating passage 39 Movable member 40 First through hole 41 Second through Hole 42 elastic member 43 orifice hole 44 link mechanism 50 closing member

Continuation of the front page (72) Inventor Kiyoshi Sanda 39, Higashihara, Chiyo, Odai-gun, Osato-gun, Saitama Prefecture F term (reference) 3H057 AA04 BB32 BB38 CC05 DD01 EE07 FA04 FC05 FD19 HH01 HH18 HH20

Claims (8)

[Claims] 1. A high-pressure side passage portion into which a refrigerant condensed by the condenser flows, and a low-pressure side passage for supplying the refrigerant to the evaporator. A pressure reducing means for reducing the pressure of the refrigerant flowing from the high pressure side passage to the low pressure side passage, and a pressure reducing means for the refrigerant from the high pressure side passage even when the refrigerant pressure reducing means is not functioning. An expansion device comprising: a refrigerant leak unit that allows the refrigerant to flow through the low-pressure side passage portion. 2. The pressure reducing means for the refrigerant includes a communication passage communicating the high-pressure passage and the low-pressure passage, an operating rod sliding hole formed to penetrate the communication passage, An operating rod having an operating rod disposed at a sliding hole of the operating rod and moving in the axial direction in accordance with the temperature of the evaporator or the blowing temperature immediately after the evaporator and having a valve element at a tip thereof; A pressure mechanism that constantly presses the valve body and a valve seat formed at a valve body side opening portion of the communication path, and the valve body separates from the valve seat when the refrigerant pressure reducing unit is functioning. 2. The expansion device according to claim 1, wherein the communication passage is opened, and the valve body contacts the valve seat to close the communication passage in a state where the refrigerant pressure reducing unit is not functioning. 3. An orifice hole communicating the high-pressure side passage portion and the low-pressure side passage portion, wherein the refrigerant leakage means includes:
A movable member disposed so as to be movable in the axial direction of the orifice hole and having a closing portion for closing the orifice hole, and another pressing mechanism for constantly pressing the movable member in the direction of the orifice hole; In the state where the refrigerant pressure reducing means is functioning, the closing portion closes the orifice hole by being pressed by the other pressing mechanism, and the other in the state where the refrigerant pressure reducing means is not functioning. 3. The expansion device according to claim 1, wherein the closing portion is separated from the orifice hole by pressing in a direction opposite to a direction pressed by the pressing mechanism. 4. 4. A storage space extending axially from the high pressure side passage portion downstream of the high pressure side passage portion, and an orifice hole communicating the storage space with the low pressure side passage portion downstream of the high pressure side passage portion. A movable member housed in the housing space and having at least a first through hole communicating with the high pressure side passage portion and a second through hole extending from the first through hole to the orifice hole side; The movable member is configured such that the second through-hole is not communicated with the low-pressure side passage portion when the refrigerant pressure reducing means is functioning. Wherein the second through hole is moved to a position where the second through hole communicates with the orifice hole by pressing from the high pressure side passage portion when the refrigerant pressure reducing means is not functioning. The expansion according to claim 1 or claim 2. Tensioning device. 5. The expansion device according to claim 2, wherein the refrigerant leakage means comprises an orifice hole formed in the valve body of the operation rod in an axial direction of the operation rod. 6. An orifice hole communicating the high-pressure side passage portion and the low-pressure side passage portion, wherein the refrigerant leakage means includes:
A link mechanism formed with a closing member for closing the orifice hole at the tip, wherein the link mechanism closes the orifice hole with the closing member in a state where the refrigerant pressure reducing means is functioning, The structure according to claim 1 or 2, wherein the blocking member moves in the axial direction of the orifice hole to open the orifice hole when the refrigerant pressure reducing means is not functioning. Expansion device. 7. The link mechanism is connected to the operating rod in a passage portion on a side opposite to the side having the valve body with respect to the communication path, and integrally moves in the axial direction of the operating rod, and The expansion device according to claim 6, wherein a member is provided at a tip of a link rod extending in a direction of the orifice hole. 8. The link mechanism is connected to the operating rod in a passage on the same side as the side having the valve body with respect to the communication path, moves integrally in the axial direction of the operating rod, and closes the closing mechanism. The expansion device according to claim 6, wherein a member is provided at a tip of a link rod inserted through the orifice hole.