JPH1163738A - Freezer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a four-way valve to be changed over positively even at the time of low differential pressure. SOLUTION: A four-way valve 11 is arranged at a refrigerant circulating system 30 of a freezer device 10 in order to change over a refrigerant flowing direction in a reversible manner. The four-way valve 11 is operated such that a slide valve 14 is moved under a pilot pressure given from a pilot solenoid valve 20 to pilot chambers 18, 19 and the continuity is switched between a discharging port 11a and a suction port 11d and between two selection ports 11b and 11c. The pilot solenoid valve 20 is operated such that four two-way solenoid valves 21, 22, 23 and 24 are changed over by a changing-over device 25 and as a high pressure a pressure just before discharging at an excessive compression part a compressor 31 is taken out of a load-up port 37, resulting in that the changing-over operation can be performed positively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus having a four-way valve for switching a refrigerant flow direction in a refrigerant circulation system.

[0002]

2. Description of the Related Art Conventionally, a refrigeration system constituting a refrigeration cycle of a refrigerant compression type has a reversible switching of a refrigerant flow direction in a refrigerant circulation system to enable cooling and heating by a heat pump. A four-way valve 1 as shown in FIG. 4 is used. The four-way valve is also called a four-way switching valve, a four-way valve, a four-way switching valve, or the like. The four-way valve (1) has a discharge port (1A) connected to the discharge side of the compressor, two switching ports (1B, 1C), and a suction port (1D) connected to the suction side of the compressor. (2) and a valve seat (3), a slide valve (4), and a piston (5, 6) for switching the connection destination of the switching port (1B, 1C) therein. The slide valve (4) is brought into a state shown in the drawing, that is, a state in which the switching port (1B) is electrically connected to the suction port (1D) and the switching port (1C) is electrically connected to the discharge port (1A) by the spring (7). Energized to maintain. When the pilot valve (8) is switched by supplying a current to the coil (9), the piston (6) is sucked, and the slide valve (4) slides to the right in the figure with respect to the valve seat (3). Move the switch port (1B, 1
C) has a suction port (1D) and a discharge port (1A)
Can be switched to be conductive.

In a four-way valve (1) as shown in FIG. 4, the high pressure side is closed at a position where the slide valve (4) is moving during switching, so that abnormal high pressure is not generated on the discharge side of the compressor. It is set so that the refrigerant leaks from the high pressure side to the low pressure side for a very short time. In such a high-low pressure bypass, a four-way valve ( The valve body (2) of 1) is switched. Further, in such a four-way valve (1), the capacity of the valve body (2) needs to be selected so as to correspond to the refrigerant flow rate in the refrigerating apparatus. If the refrigerant gas supply capacity of the compressor is insufficient, the differential pressure required for switching cannot be obtained, and the slide valve (4) may stop halfway and cannot be switched. Conversely, if the capacity of the valve body (2) of the four-way valve (1) is too small compared to the refrigerant gas supply capacity of the compressor, the switching can be performed sufficiently, but the four-way valve (1) is supplied with the refrigerant. This is because the pressure drop due to the pressure loss during the passage increases, and it is not possible to exert sufficient cooling and heating capacity as a refrigerating device. In particular, if the slide valve is driven directly by electromagnetic force without using the pilot method, the driving force is insufficient, and only a small capacity can be obtained.

The prior art for providing a sufficient differential pressure to a four-way valve to reliably perform a switching operation is disclosed, for example, in Japanese Utility Model Publication No. 5-44680 by the present applicant. This prior art focuses on the fact that when the high pressure side and the low pressure side are conducted during the movement of the slide valve, the refrigerant pressure immediately before the discharge of the rotary compressor becomes higher than the discharge pressure, and the pilot pressure is reduced. The high pressure side is switched to the higher one of the discharge pressure of the compressor or the pressure immediately before discharge.

Japanese Patent Application Laid-Open No. 8-135812 discloses a four-way valve in which a drive mechanism including a magnetic coil and a permanent magnet is integrated with a valve body and switching is performed by rotating a rotor. In this prior art, even if the high pressure side and the low pressure side are conducted, the rotor is driven by the driving force of the driving mechanism,
The situation in which switching cannot be performed is avoided.

[0006]

As described above, in the four-way valve (1), the high-pressure side and the low-pressure side are bypassed during the movement of the slide valve (4). For this reason, especially at the time of a low differential pressure, there is a possibility that the high / low differential pressure decreases during the switching and the switching becomes impossible, or the intermediate stop state cannot be recovered.

In the prior art disclosed in Japanese Utility Model Publication No. 5-44680, the discharge pressure of the compressor is compared with the pressure immediately before the discharge, and the higher pressure is switched as the high pressure side of the pilot pressure. The number of necessary components increases, and the manufacturing cost of the refrigeration system increases. In the prior art of Japanese Patent Application Laid-Open No. 8-135812, it is necessary to design the rotor and the electromagnetic drive mechanism integrally, and it is expected that it is difficult to increase the capacity especially.

An object of the present invention is to provide a refrigeration apparatus which can reliably switch a four-way valve even at a low differential pressure where a high or low differential pressure bypasses.

[0009]

The present invention relates to a compressor (3).
It has a high-pressure chamber (38) and a low-pressure chamber (39) connected to the discharge side (32) and the suction side (36) of 1), respectively, according to the difference in drive pressure applied to the two pilot chambers (18, 19). A refrigerating apparatus (10) including a four-way valve (11) for switching a refrigerant flow direction in a refrigerant circulation system (30) between a cooling cycle and a heating cycle;
High pressure extraction means (37) for extracting pressure immediately before discharge from the compressor (31), high pressure immediately before discharge extracted by the high pressure extraction means (37), and the suction side (36) of the compressor (31)
Of the pilot chamber (18, 1) of the four-way valve (11).
9) a solenoid valve (20, 21, 22, 23, 24; 40; 41,
42).

According to the present invention, the pressure immediately before discharge is extracted from the compressor (31) by the high-pressure extraction means (37). This pressure is constantly generated in the over-compression section of the positive displacement compressor (31), and particularly, on the discharge side (3) of the compressor (31).
Even at the time of a low pressure difference where the pressure difference between the suction side (2) and the suction side (37) is bypassed, the pressure becomes higher than the discharge pressure.
8, 19) can be always higher than the pilot chambers (18, 19) connected to the suction side of the compressor (31). This makes it possible to reliably switch the four-way valve (11) even in the state of intermediate stop or during high / low pressure bypass during switching.

Further, in the present invention, one end of the solenoid valve (20) is commonly connected to a take-out side of the high-pressure extraction means (37), and the other end has one or the other pilot chamber of the four-way valve (11). A first electromagnetic two-way valve (21) and a second electromagnetic two-way valve (22) respectively connected to (18, 19) and one end are commonly connected to the suction side (36) of the compressor (31). A third electromagnetic two-way valve (23) and a fourth electromagnetic two-way valve (24), the other ends of which are respectively connected to the other or one of the pilot chambers (18, 19) of the four-way valve (11). , A set of the first electromagnetic two-way valve (21) and the third electromagnetic two-way valve (23) and a set of the second electromagnetic two-way valve (22) and the fourth electromagnetic two-way valve (24). Switching means (2) for switching one set to open when the other set is closed
5) is provided.

According to the present invention, four electromagnetic two-way valves (2
Pilot rooms (18, 19) at 1, 22, 23, 24)
Can be prevented from bypassing the differential pressure of the pilot pressure during the switching of the pressure, the switching of the four-way valve (11) can be surely performed.

The present invention also relates to the high pressure extracting means (37).
Is characterized in that even if the four-way valve (11) stops intermediately when the compressor (31) is started, the driving force can be taken out and the four-way valve (11) can be switched.

According to the present invention, even if the four-way valve (11) is stopped intermediately and the refrigerant leaks from the high pressure side to the low pressure side and the differential pressure between the high and low pressures becomes small, the high pressure just before discharge is used. The four-way valve (11) can be switched.

[0015]

FIG. 1 shows a schematic configuration of a refrigeration system (10) according to an embodiment of the present invention. A four-way valve (1) for switching the flow direction of refrigerant such as R22 and R502
1) has a valve body (12) including a discharge port (11a), two switching ports (11b, 11c), and a suction port (11d). In the valve body (12), the switching ports (11b, 11b) are arranged on both sides of the central suction port (11d) along the valve seat (13).
c) is arranged. The slide valve (14) slides and displaces on the valve seat (13) to selectively conduct between the suction port (11d) and one of the switching ports (11b, 11c). Switching port (11
The other of b and 11c) conducts to the discharge port (11a). The movement of the slide valve (14) is controlled by the piston (15, 1).
6) is driven by the pilot pressure introduced into the pilot chambers (18, 19).

The pilot pressure is controlled by a pilot solenoid valve (2
0). Pilot solenoid valve (20)
Are two pairs of solenoid two-way valves (21, 22, 2
3, 24). Each electromagnetic two-way valve (21,
, 23, 24) is connected to a first electromagnetic two-way valve (2
The combination of 1) and the second electromagnetic two-way valve (22) is on the high pressure side, and the combination of the third electromagnetic two-way valve (23) and the fourth electromagnetic two-way valve (24) is on the low pressure side. Connected in common. The other ends of the first electromagnetic two-way valve (21) and the fourth electromagnetic two-way valve (24) are connected to the A chamber, which is the pilot chamber (18) on the high pressure side during cooling in the state of FIG. Connected in common. The other ends of the second electromagnetic two-way valve (22) and the third electromagnetic two-way valve (23) are connected to the pilot chamber (1) on the low pressure side in FIG.
9) is connected to room B. The switching device (25) switches each of the electromagnetic two-way valves (21, 22, 23, 24) as shown in Table 1 below, and switches the pilot chambers (18, 19) to A.
The pressure in the chamber and the chamber B is switched to the high pressure HP or the low pressure LP. The open state is indicated by "" and the closed state is indicated by "x".

[0017]

[Table 1]

A refrigerant circulation system (30) in which the direction of refrigerant flow is switched by the operation of the switching device (25) as shown in Table 1.
Then, high-pressure refrigerant gas is discharged from the discharge port (32) of the compressor (31), and the discharge port (11) of the four-way valve (11) is discharged.
It is led to a). At the time of cooling indicated by the solid arrow, the refrigerant gas is supplied from one of the selection ports (11b) to the outdoor heat exchanger (33), and releases the latent heat to condense. In order to evaporate the condensed refrigerant liquid in the indoor heat exchanger (34), the refrigerant is allowed to pass through the expansion valve (35) to rapidly reduce the pressure. Cooling is performed with latent heat taken from the surroundings during evaporation. The evaporated refrigerant gas is sucked into the suction port (36) of the compressor (31) from the other selection port (11c) of the four-way valve (11) via the suction port (11d).

FIG. 2 shows the relationship between the compression time / stroke of the positive displacement compressor and the pressure in the cylinder. It can be seen that immediately before the discharge, an overcompressed portion where the pressure becomes higher than the discharge pressure occurs. In the present embodiment, a positive displacement rotary type is used for the compressor (31), a load-up port (37) as high-pressure extraction means is provided, and the pressure HHP immediately before discharge is taken out. As shown by the imaginary line in FIG. 2, even when the high and low pressures of the discharge pressure and the suction pressure are the same, the compressor load-up port pressure P generates a high pressure. The pressure HHP immediately before the discharge is equal to the first
It is selectively guided to the pilot chamber (18) or the pilot chamber (19) in the valve body (12) via the electromagnetic two-way valve (21) or the second electromagnetic two-way valve (22). The pilot chamber (18, 1) to which the pressure HHP immediately before discharge is not given
9) is connected to the low pressure LP on the suction port (36) side of the compressor (31) via the third electromagnetic two-way valve (23) or the fourth electromagnetic two-way valve (24). The space formed between the pistons (15, 16) in the valve body (12) communicates with the high pressure chamber (38) communicating with the discharge port (11a) and the suction port (11d) by the slide valve (14). And a low-pressure chamber (39). One pilot room (1
8, 19), the pressure HHP immediately before discharge is always higher than the pressure of the high-pressure chamber (38), so that the slide valve (14) is slidably displaced with respect to the valve seat (13), and the switching port is switched. The direction of refrigerant flow between (11b, 11c) can be reliably switched. For example, a compressor (3
If the four-way valve (11) stops intermediately at the time of the start of 1), the pressure difference between the high-pressure chamber (38) and the low-pressure chamber (39) becomes small, but immediately before the discharge of the load-up port (37). The pressure can be reliably switched by using the pressure HHP as the driving pressure.

FIG. 3 shows a configuration of a pilot solenoid valve according to another embodiment of the present invention. Other configurations of the refrigeration apparatus are the same as those of the embodiment of FIG. FIG. 3 (a)
The structure using a pilot four-way valve (40) is shown. FIG.
(B) shows a configuration using two pilot three-way valves (41, 42). Since only one pilot four-way valve (40) needs to be used, the manufacturing cost is reduced. However,
Since 1 kg / cm ² is required as the minimum operating differential pressure, when the flow rate of the load-up port (37) is small, it may be difficult to switch from the intermediate stop state. The use of two pilot three-way valves (41, 42) increases the manufacturing cost. The minimum operating differential pressure must also be relatively large.

[0021]

As described above, according to the present invention, the pressure at which the pressure immediately before the discharge is extracted from the compressor (31) by the high-pressure extraction means (37) and the suction side (3) of the compressor (31).
6) is applied between the pilot chambers (18, 19), so that the four-way valve (11) can be reliably switched even in the intermediate stop state or during the high / low pressure bypass at the time of switching. Can be.

Further, according to the present invention, the four electromagnetic two-way valves (21, 22, 23, 24) can be alternately switched so that the differential pressure of the pilot pressure is not bypassed, so that it is ensured. Switching of the four-way valve (11) can be performed.

Further, according to the present invention, even if the four-way valve (11) stops intermediately when the compressor (31) is started, the switching can be performed reliably.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a refrigerant circulation system according to an embodiment of the present invention.

FIG. 2 is a graph showing pressure characteristics of the compressor (31) of the embodiment of FIG.

FIG. 3 is a diagram showing a configuration of a pilot solenoid valve according to another embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional four-way valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Refrigeration apparatus 11 Four-way valve 11a Discharge port 11b, 11c Selection port 11d Suction port 12 Valve body 13 Valve seat 14 Slide valve 15, 16 Piston 18, 19 Pilot room 20 Pilot solenoid valve 21 First electromagnetic two-way valve 22 Second electromagnetic solenoid Two-way valve 23 Third electromagnetic two-way valve 24 Fourth electromagnetic two-way valve 25 Switching device 30 Refrigerant circulation system 31 Compressor 32 Discharge port 36 Suction port 37 Load-up port 38 High-pressure chamber 39 Low-pressure chamber 40 Pilot four-way valve 41, 42 Pilot three-way valve

Claims (3)

[Claims] 1. A high-pressure chamber (38) and a low-pressure chamber (39) connected to a discharge side (32) and a suction side (36) of a compressor (31), respectively, and two pilot chambers (1).
In the refrigerating apparatus (10) having the four-way valve (11) for switching the refrigerant flow direction in the refrigerant circulation system (30) between the cooling cycle and the heating cycle by a difference in the driving pressure applied to the cooling cycle (8, 19). High pressure extraction means (37) for extracting pressure immediately before discharge from the compressor (31); high pressure immediately before discharge extracted by the high pressure extraction means (37); and low pressure on the suction side (36) of the compressor (31). Solenoid valves (20, 20) for switching the driving pressure so as to apply the pressure to one or the other of the pilot chambers (18, 19) of the four-way valve (11).
21, 22, 23, 24; 40; 41, 42). 2. The solenoid valve (20) has one end commonly connected to the extraction side of the high-pressure extraction means (37), and the other end connected to one or the other pilot chamber (18, 18) of the four-way valve (11). 19) connected to the first
An electromagnetic two-way valve (21) and a second electromagnetic two-way valve (22), one end of which is commonly connected to the suction side (36) of the compressor (31), and the other end of which is the other of the four-way valve (11) Alternatively, a third electromagnetic two-way valve (23) and a fourth electromagnetic two-way valve (24) connected to the one pilot chamber (18, 19), respectively.
And a first electromagnetic two-way valve (21) and a third electromagnetic two-way valve (23)
And a set of the second electromagnetic two-way valve (22) and the fourth electromagnetic two-way valve (24) so that when one of the sets is opened, the other is closed. The refrigeration apparatus according to claim 1, further comprising: 3. The high-pressure extracting means (37) can take out the driving force and switch the four-way valve (11) even when the four-way valve (11) stops intermediately when the compressor (31) is started. The refrigeration apparatus according to claim 1 or 2, wherein: