WO2002057628A1

WO2002057628A1 - Compression displacement controller of refrigerating cycle

Info

Publication number: WO2002057628A1
Application number: PCT/JP2002/000364
Authority: WO
Inventors: Hisatoshi Hirota
Original assignee: Tgk Co., Ltd.
Priority date: 2001-01-19
Filing date: 2002-01-18
Publication date: 2002-07-25
Also published as: EP1363021A1; US20030035733A1; JP2002285973A; JP4070425B2

Abstract

A compression displacement controller of a refrigerating cycle, comprising a variable displacement compressor (10) for compressing refrigerant sucked from a suction chamber (3) connected to a suction line (1), discharging the refrigerant to a discharge chamber (4) connected to a discharge line (2), and varying the discharge amount of the refrigerant due to a pressure variation in a pressure regulating chamber (12) pressure-controlled by a solenoid control valve (20), wherein, when an electric power is not supplied to the solenoid control valve (20), the solenoid control valve (20) disposed between the discharge chamber (4) and the pressure regulating valve (12) is held in an open state so that the variable displacement compressor (10) can be brought into a minimum discharge amount in a variable range, whereby a clutch to disable the operation of the variable displacement compressor (10) can be eliminated, and an installation cost can be reduced remarkably.

Description

Description Refrigeration cycle compression capacity control device Technical field

The present invention relates to a compression capacity control device for a refrigeration cycle used for an air conditioner for a vehicle or the like. Background art

The compressor used in the refrigeration cycle of an automotive air conditioner cannot control the rotation speed because it is directly connected to the engine by a belt. Therefore, in order to obtain an appropriate cooling capacity without being restricted by the engine speed, a variable displacement compressor that can change the compression capacity (discharge rate) is used.

Such a variable displacement compressor generally compresses refrigerant sucked from a suction chamber leading to a suction pipe and discharges the compressed refrigerant into a discharge chamber leading to a discharge pipe. The discharge amount of the refrigerant is changed by the pressure change.

In a conventional device, an electromagnetic clutch or the like is provided on a part of a pulley that receives rotation of a belt directly connected to an engine in order to prevent the compressor from being driven in an operating state where it is not necessary to compress the refrigerant. In order to prevent the operation of the compressor, the equipment cost was incurred. Disclosure of the invention

Therefore, an object of the present invention is to provide a compression capacity control device for a refrigeration cycle that does not require a clutch for preventing the operation of the compressor and can greatly reduce the cost of the device.

In order to achieve the above object, a compression capacity control device for a refrigeration cycle according to the present invention compresses refrigerant sucked from a suction chamber leading to a suction pipe, discharges the compressed refrigerant to a discharge chamber leading to a discharge pipe, and uses an electromagnetic control valve. A compression capacity control device for a refrigeration cycle having a variable capacity compressor in which the discharge amount of refrigerant is changed by a change in pressure in a pressure-controlled pressure regulating chamber. When the solenoid valve is not energized, the variable displacement compressor is set to a variable discharge range with a minimum discharge amount.

The electromagnetic control valve communicates between the pressure regulating chamber and the discharge chamber such that the pressure difference between at least one of the pressure in the pressure regulating chamber and the pressure in the suction chamber and the pressure in the discharge chamber is maintained at a predetermined pressure. The pressure difference may be changed by changing the electromagnetic force of the electromagnetic control valve to change the pressure of the pressure regulating chamber, thereby controlling the discharge amount of the refrigerant.

A biasing means is provided for maintaining the electromagnetic control valve in the open state when the electromagnetic control valve is not energized. May be set to the minimum discharge amount.

Further, a suction path opening / closing valve that closes between the suction pipe line and the suction chamber when the pressure difference between the discharge chamber and the suction chamber becomes equal to or less than a predetermined value may be provided.

The above and other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view showing the overall configuration of a compression capacity control device for a refrigeration cycle according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a capacity control solenoid valve according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing an overall configuration of a compression capacity control device for a refrigeration cycle according to a third embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

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

In FIG. 1, reference numeral 10 denotes a swash plate type variable displacement compressor which is used for an air conditioning refrigeration cycle of an automobile. R134A or the like is used as the refrigerant, but the present invention may be applied to a refrigeration cycle using carbon dioxide as the refrigerant.

Reference numeral 1 denotes a rotating shaft disposed in an airtight crank chamber 12 (pressure regulating chamber), which is a rotary shaft driven by a drive belt (not shown) directly connected to the engine. 3 is connected to the axis position, and the rotation axis The swing plate 14 arranged in the crank chamber 12 at an angle with respect to 11 swings. A piston 17 is arranged reciprocally in a cylinder 15 arranged in a peripheral part in the crank chamber 12, and the piston 17 and the rocking plate 14 are connected by a rod 18. I have.

As a result, when the oscillating plate 14 oscillates, the piston 17 reciprocates in the cylinder 15, and a low-pressure (suction pressure P s) refrigerant is sucked into the cylinder 15 from the suction chamber 3. The refrigerant is compressed in the cylinder 15, and the high-pressure refrigerant (discharge pressure P d) is discharged into the discharge chamber 4.

Refrigerant is fed into the suction chamber 3 from the upstream side of the evaporator (not shown) via the suction pipe 1, and from the discharge chamber 4 to the downstream side of the condenser (not shown). The high-pressure refrigerant is sent out via the discharge line 2.

The tilt angle of the oscillating plate 14 changes depending on the pressure in the crank chamber 12 (crank chamber pressure P c), and the amount of refrigerant discharged from the cylinder 15 (ie, , Compression capacity).

The discharge amount is often large when the oscillating plate 14 is inclined as shown by the solid line, and decreased when it is not inclined as shown by the two-dot chain line. When the rocking plate 14 is perpendicular to the rotation axis 11, the discharge amount becomes zero.

However, as the rocking plate 14 gradually shifts to a state without inclination (a state approaching the two-dot chain line), the minimum securing panel 19 mounted around the rotating shaft 11 is gradually turned by the rocking plate 14. Compressed.

As a result, the reaction force from the minimum securing spring 19 to the oscillating plate 14 gradually increases, and the oscillating plate 14 does not reach the direction perpendicular to the rotating shaft 11 and the discharge amount is maximized. For example, the discharge amount should not be less than about 3 to 5%.

Such an operation state in which the discharge amount is minimum is called minimum operation. Such a minimum securing spring 19 is publicly known, and has, for example, a configuration in which a corrugated panel and a coil panel are combined.

Reference numeral 20 denotes a capacity control solenoid valve (electromagnetic control valve) for electromagnetic solenoid control for performing compression capacity control by automatically controlling the crank chamber pressure (P c). 21 is an electromagnetic coil and 22 is a fixed iron core. The movable iron core 23 and the valve body 25 are arranged so as to pass through the fixed iron core 22 and are connected by an axially movable rod 24, and are urged by compression coil springs 27, 28 from both ends. ing.

29 is an o-ring for sealing. The biasing force of the two compression coil springs 27, 28 is set to be larger in the valve-opening spring 28 than in the valve-closing spring 27.

The valve seat 26 is formed between the crank chamber communication passage 5 communicating with the crank chamber 12 and the discharge chamber communication passage 6 communicating with the discharge chamber 4, and the valve body 25 is connected to the valve seat from the crank chamber communication passage 5 side. It is arranged facing 26. The communication between the crank chamber communication passage 5 and the suction pipe line 1 is communicated via a thin leak passage 7.

With such a configuration, the differential pressure (Pd_Pc) between the discharge pressure (Pd) and the crank chamber pressure (Pc) acts on the valve body 25 in the opening direction, and in the closing direction, the electromagnetic force of the displacement control solenoid valve 20 The force (including the biasing force of the compression coil springs 27 and 28) acts. Therefore, when the current flowing through the electromagnetic coil 21 is constant and the electromagnetic force of the displacement control solenoid valve 20 is constant, the differential pressure (Pd—Pc) between the discharge pressure (Pd) and the crank chamber pressure (Pc) is The valve body 25 is opened and closed in accordance with the fluctuation, and the differential pressure (Pd-Pc) is kept constant, whereby the crank chamber pressure (Pc) is controlled to a value corresponding to the discharge pressure (Pd), and the compression is performed. The volume (discharge volume) is kept constant.

When the electromagnetic current of the displacement control solenoid valve 20 is changed by changing the value of the current flowing through the solenoid coil 21, the differential pressure (Pd-Pc) that is kept constant changes correspondingly. Thus, the compression capacity (discharge rate) is kept constant at different levels. That is, when the electromagnetic force of the displacement control solenoid valve 20 is reduced, the constant pressure difference (Pd-Pc) decreases, so that the crank chamber pressure (Pc) increases in a direction approaching the discharge pressure (Pd). However, the swinging plate 14 approaches a direction perpendicular to the rotation axis 11 and the refrigerant discharge amount decreases.

Conversely, if the electromagnetic force of the displacement control solenoid valve 20 is increased, the pressure difference (Pd—Pc) that is kept constant increases, so that the crank chamber pressure (Pc) moves away from the discharge pressure (Pd). And the inclination angle of the swing plate 14 with respect to the rotating shaft 11 increases, so that the refrigerant discharge amount increases. The current supplied to the electromagnetic coil 21 is controlled by detecting signals from the engine, the temperature inside and outside the vehicle, evaporator sensors, and other sensors for detecting various conditions. And a control signal based on the calculation result is sent from the control unit 40 to the electromagnetic coil 21 to be performed. The drive circuit of the electromagnetic coil 21 is not shown.

When the power supply to the electromagnetic coil 21 is stopped, the difference between the urging forces of the two compression coil springs 27 and 28 for urging the valve body 25 of the displacement control electromagnetic valve 20 indicates the valve body. 25 is opened away from the valve seat 26.

Then, the differential pressure between the discharge pressure (P d) and the crank chamber pressure (P c) disappears (that is, P d — P c 0). Before this, the tilting state of the rocking plate 14 is balanced with the reaction force from the minimum securing panel 19, and the compressor 10 is in a state of maintaining the minimum operation.

In this way, if the power supply to the electromagnetic coil 21 of the displacement control solenoid valve 20 is stopped, the compressor 10 enters the minimum operation state, so that even when it is not necessary to operate the compressor 10, the rotating shaft 11 can be operated. It can be kept in a state of being driven to rotate.

FIG. 2 shows a displacement control solenoid valve 20 according to a second embodiment of the present invention. The compressor 10 is the same as that of the first embodiment and is not shown. In addition, leak paths will be arranged as appropriate.

In this embodiment, a piston rod 25p having the same pressure receiving area as the valve seat 26 is provided on the back side of the valve body 25, and suction is performed in a space facing the back surface of the piston rod 25p. The chamber communication passage 8 is connected, the crank chamber communication passage 5 is connected to the space facing the side surface of the piston rod 25 p, and the discharge chamber connection is provided in the space behind the valve seat 26 when viewed from the valve body 25 side. Passage 6 is connected.

As a result, the crank chamber pressure (P c) applied to the piston rod 25 p and the valve body 25, etc. is canceled, and the differential pressure (P d -P d) between the discharge pressure (P d) and the suction pressure (P s) s) causes the valve body 25 to open and close, which causes the crank chamber 12 and the discharge chamber

4 is opened and closed to control the compression capacity.

Then, when the energization of the electromagnetic coil 2 1 is stopped, two compression coil springs 2

Due to the difference between the urging forces of 7, 28, the valve body 25 is opened away from the valve seat 26, A state in which the minimum operation is maintained.

As described above, according to the present invention, the pressure difference between at least one of the pressure (Pc) in the crank chamber 12 and the pressure (Ps) in the suction pipe 1 and the pressure (Pd) in the discharge chamber 4 is reduced to a predetermined pressure difference. The pressure difference between the crank chamber 12 and the discharge chamber 4 is changed by changing the electromagnetic force of the displacement control solenoid valve 20 by changing the electromagnetic force of the displacement control solenoid valve 20 to maintain the pressure (Pc ) Can be applied to a device in which the discharge amount changes accordingly, and further to a device controlled by another method. FIG. 3 shows a third embodiment of the present invention. In the apparatus having the same configuration as that of the first embodiment, when the pressure difference between the discharge chamber 4 and the suction chamber 3 becomes lower than a predetermined value, suction is performed. A suction passage opening / closing valve 30 that closes between the pipe 1 and the suction chamber 3 is provided.

In this embodiment, a valve body 32 disposed on a valve seat 31 formed between the suction pipe 1 and the suction chamber 3 so as to face from the suction pipe 1 side is provided with a compression coil spring in a valve closing direction. It is arranged biased by 33. Reference numeral 34 denotes a spring receiver in which a large cutout is formed so as not to hinder the passage of the refrigerant.

A pressure receiving piston 35 that receives the pressure (Pd) of the discharge chamber 4 and the pressure (P s) of the suction chamber 3 from both sides is connected to the valve body 32, and the pressure (Pd) of the discharge chamber 4 and the suction chamber When the pressure difference (Pd_Ps) from the pressure (Ps) in Step 3 is larger than a certain value, the valve body 32 separates from the valve seat 31 and the suction passage opening / closing valve 30 is opened. When (Pd-Ps) becomes smaller than a certain value, the valve element 32 is pressed against the valve seat 31, and the suction path on-off valve 30 is closed.

In this way, the low-pressure refrigerant in the suction line 1 is not sucked into the compressor 10 during the minimum operation, so that the fins of the evaporator do not freeze during the minimum operation when the load is small as in winter. be able to.

According to the present invention, the variable displacement compressor maintains the state of the minimum discharge amount in the variable range in a state where power is not supplied to the electromagnetic control valve, so that the compressor is not operated. This eliminates the need for a clutch, thus greatly reducing equipment costs.

The above merely illustrates the principles of the invention. In addition, many modifications and changes are possible for those skilled in the art and It is not limited to the examples and applications, but all corresponding variations and equivalents are considered to be within the scope of the present invention by the appended claims and their equivalents.

Claims

The scope of the claims

1. The refrigerant sucked from the suction chamber leading to the suction pipe is compressed and discharged to the discharge chamber leading to the discharge pipe, and the discharge amount of the refrigerant is changed by the pressure change of the pressure control chamber pressure-controlled by the electromagnetic control valve. In a compression capacity control device of a refrigeration cycle having a variable capacity compressor adapted to vary,

A compression capacity control device for a refrigeration cycle, characterized in that the capacity variable compressor is set to a variable range of a minimum discharge amount when no power is supplied to the electromagnetic control valve.

2. The pressure control chamber and the discharge chamber are configured to maintain a pressure difference between at least one of the pressure of the pressure control chamber and the pressure of the suction chamber and the pressure of the discharge chamber at a predetermined pressure difference. By communicating with and closing the chamber, and changing the electromagnetic force of the electromagnetic control valve, the differential pressure changes to change the pressure in the pressure regulating chamber, and the discharge amount of the refrigerant is controlled. 2. The compression capacity control device for a refrigeration cycle according to claim 1.

3. An urging means is provided for maintaining the electromagnetic control valve in an open state when the electromagnetic control valve is not energized, and the variable displacement compression is performed by maintaining the electromagnetic control valve in an open state. 3. The compression capacity control device for a refrigeration cycle according to claim 1, wherein the compressor is in a state of a minimum discharge amount in a variable range.

4. A suction path opening / closing valve that closes between the suction pipe line and the suction chamber when a pressure difference between the discharge chamber and the suction chamber becomes a predetermined pressure or less. Or the compression capacity control device for a refrigeration cycle according to item 3.