JP5357495B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus having an improved compressor control method which includes two cylinders and can be used by selectively switching one or two.

  Conventionally, a compressor is mounted on a refrigeration cycle apparatus such as an air conditioner.

  The machine room of the outdoor unit is provided with a rotary compression type compressor having two cylinders, and this compressor can be used by selectively switching one or two of them according to the load. A switching valve is interposed, and a suction pipe is directly connected to the suction side of one cylinder via an accumulator. A suction pipe via a buffer muffler is connected to the suction side of the other cylinder, and the low pressure side is connected via an accumulator. The piping is connected or switched so that the high-pressure side piping from the discharge pipe is connected.

  Conventionally, the drive power source of the cylinder number switching valve has been selected and controlled in accordance with the supply power specification side of the air conditioner. In this case, for example, a single-phase 100V model and a 200V model have different power supply coils even when the same switching valve is used, and standardization and commonization of parts are not achieved.

  Further, since the coil is always energized, it requires power consumption for holding the valve position during operation and consumes power.

  The same can be said for the cycle switching valve that switches between cooling and heating.

Patent Document 1 discloses a refrigeration cycle apparatus that includes a two-cylinder rotary compressor that performs a compression operation and a non-compression operation according to the magnitude of a load, and that switches from a compression operation to a non-compression operation or vice versa. Proposed.
JP 2005-171897 A

  The present invention has been made in consideration of the above-described circumstances, and it is possible to use the same coil between refrigeration cycle apparatuses having different voltages, and standardization in a refrigeration cycle apparatus over a high range can be achieved. It is another object of the present invention to provide a refrigeration cycle apparatus that is energized only at the time of switching the coil and can save energy without requiring power consumption for holding the valve position during operation.

The refrigeration cycle apparatus according to the present invention includes a compressor that includes two cylinders and can be used by selectively switching between one and two, and is provided on the suction side of the compressor for operating one or two of the cylinders. Cylinder number switching valve for switching, cycle switching valve for switching the flow of refrigerant during cooling operation and heating operation of the refrigeration cycle, an electric expansion valve for depressurizing the refrigerant and controlling the flow rate, and a valve drive circuit for driving each of the valves And a refrigeration cycle apparatus having a control device that transmits a valve control signal to the valve drive circuit and controls the drive of each valve, wherein the electric expansion valve is a valve whose valve opening is controlled by a drive pulse. Each of the cylinder number switching valve and the cycle switching valve is a self-holding type valve that switches the valve by energizing the coil only during the valve switching operation. A dynamic power supply, an electric expansion valve drive circuit that is connected to the drive power supply and generates a drive pulse in the electric expansion valve, and a switching valve drive circuit that is connected to the drive power supply and switches a cylinder number switching valve or a cycle switching valve The control device controls to transmit the drive pulse to the electric expansion valve drive circuit in a normal operation state, and at the time of switching operation of the cylinder number switching valve and the cycle switching valve, the electric expansion valve A switching drive signal is transmitted to the switching valve drive circuit in a state where transmission of the drive pulse of the drive circuit is stopped.

  According to the refrigeration cycle apparatus according to the present invention, the same coil can be used between refrigeration cycle apparatuses having different voltages, and standardization in a refrigeration cycle apparatus over a wide range can be achieved. Thus, it is possible to provide a refrigeration cycle apparatus that can save energy without using power consumption for holding the valve position during operation, by using an energization method only during switching.

  An embodiment of a refrigeration cycle apparatus according to the present invention will be described with reference to the drawings, taking an air conditioner as an example.

  FIG. 1 is a conceptual diagram of a refrigeration cycle used in an air conditioner according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a machine room structure of an outdoor unit used in the air conditioner of an embodiment of the present invention. FIG. 3 is a longitudinal sectional view of a compressor provided with a cylinder number switching valve used in the air conditioner of one embodiment of the present invention.

  As shown in FIGS. 1 and 2, an air conditioner 1 which is an embodiment of a refrigeration cycle apparatus according to the present invention is separated into an outdoor unit 2 and an indoor unit 3.

  The outdoor unit 2 is divided into a heat exchanger room (not shown) and a machine room 5 by a partition plate (not shown) on the left and right sides, and the outdoor fan 6 and the outdoor heat exchange accommodated in the heat exchanger room. 7, compressor 8 housed in machine room 5, cycle switching valve (four-way valve) 9 for cooling / heating switching, buffer muffler 10, cylinder number switching valve 11, electric expansion valve which is a pulse motor drive valve (PMV) 12, the indoor unit 3 includes an indoor heat exchanger 13 including an indoor fan 14, and the outdoor unit 2 and the indoor unit 3 include communication pipes 15 and 16, and packed valves 17 and 18 provided in the outdoor unit 2. The refrigeration cycle is configured by sequentially communicating with each other.

  As shown in FIG. 3, the compressor 8 includes a sealed container 22, and a compression mechanism section 23 is provided in the lower portion of the sealed container 22, and an electric motor section 24 is provided in the upper portion. The compression mechanism section 23 and the electric motor section are provided. 24 are connected via a rotating shaft 25.

  The compression mechanism section 23 is a twin type having two cylinders, and is composed of a first cylinder 23A constituting the first compression mechanism section and a second cylinder 23B constituting the second compression mechanism section. The

The first cylinder 23A is provided on the upper side, the first rolling piston 23a ₁ is accommodated so as to be eccentrically rotatable, and the second cylinder 23B is provided below the first cylinder 23A and separated by an intermediate partition plate 26. is, the second rolling piston 23b ₁ is eccentrically rotatably accommodated.

  The cycle switching valve 9 (FIG. 1) and the cylinder number switching valve 11 are energized only during the valve switching operation to energize the coil (solenoid), and the energized coil actuates the valve body to a predetermined position. The valve can be switched by changing the polarity of the voltage in a self-holding type in which the valve body is held at a predetermined position by mechanical means or a magnet. Use the one for DC weak voltage. Therefore, the cycle switching valve 9 and the cylinder number switching valve 11 need not always energize the coil in order to hold the valve body in a predetermined position.

  The cycle switching valve 11 is constituted by a valve functioning as a three-way valve having a first connection port on the upper surface and second and third connection ports on the lower surface, and the first connection port and the third connection port. Are connected to each other or switched so that the second connection port and the third connection port communicate. Although this valve may be a three-way valve designed for this purpose, it is configured so that the valve operates in the horizontal direction, and is normally used for mass switching and used for switching the flow path of the refrigeration cycle. The switching valve may be used with one connection port closed.

  The first cylinder 23A has a first suction side pipe 27a connected to the suction side, while the second cylinder 23B has a second suction side pipe 27b connected to the suction side. A buffer muffler 10 for obtaining a refrigerant muffler effect is interposed in the pipe 27b.

  The low-pressure side pipe 29 for returning the refrigerant to the suction side of the compressor 8 of the refrigeration cycle has a cylindrical structure that prevents the refrigerant that has not been gasified by the evaporator from being sucked into the compressor 8 in a liquid state. The accumulator 28 is interposed.

  In this accumulator 28, a refrigerant inflow low-pressure side pipe 29 is inserted into the upper part from above, and two refrigerant outflow pipes extend downward in the lower part, one of which is a compressor as the first suction side pipe 27a. The first cylinder 23A is always in communication with the first cylinder 23A. The other is connected to the second connection port of the cylinder number switching valve 11 by a low-pressure side communication pipe 29a.

  Further, a high-pressure side pipe 31 communicating with the discharge pipe 30 of the compressor 8 is connected to the first connection port of the cylinder number switching valve 11, and a second suction side pipe 27b provided with the buffer muffler 10 switches the number of cylinders. Connected to the third connection port of the valve 11.

  An oil reservoir 32 for collecting lubricating oil is provided at the inner bottom of the sealed container 22, and most of the second cylinder 23 </ b> B and most of the first cylinder 23 </ b> A are provided in the oil reservoir 32. Soaked in.

  The lowermost end surface of the rotating shaft 25 is exposed from the second bearing 25a, and an oil supply pump (not shown) is provided here. The oil supply passage communicates with the oil supply pump, and the oil supply pump sucks up the lubricating oil in the oil reservoir 32 as the rotary shaft 25 rotates, and guides it to the oil supply passage.

  Therefore, as shown in FIG. 4, in a normal operation using the two cylinders of the compressor 8, the cylinder number switching valve 11 is held in a state where the second connection port and the third connection port communicate with each other. . The refrigerant that has flowed into the accumulator 28 is divided into two by the accumulator 28, one gas refrigerant is directly sucked into the first cylinder 23 </ b> A, and the other gas refrigerant is passed through the cylinder number switching valve 11 to the second one. The air is sucked into the cylinder 23 </ b> B, the compression action is performed in both the first cylinder and the second cylinder, and the high-pressure gas is discharged from the discharge pipe 30 through the sealed container 22.

On the other hand, as shown in FIG. 5, in the small capacity operation using one cylinder of the compressor 8, the cycle switching valve 11 is maintained in a state where the first connection port and the third connection port communicate with each other. Is done. Since the second cylinder 23B communicates with the discharge pipe 30 via the high pressure side pipe 31, the cycle switching valve 11, the buffer muffler 10, and the second suction side pipe 27b, the suction side of the second cylinder 23B has a high pressure. , the pressure difference in the compression chamber of the second cylinder 23B is pressed against the second to the rolling piston 23b _1, vane 23b ₂ which has been followed is away, it becomes free. In this state, the vanes are attracted and held by the small magnets 23b3 embedded on the back side of the vanes. Since there is no partition by a vane in a cylinder, it will be in an idling state and the compression action in the 2nd cylinder 23B will be in a stop state. For this reason, the gas refrigerant that has returned to the accumulator 28 is sucked into only the first cylinder 23A via the first suction side pipe 27a. As a result, only one cylinder is operated.

  As shown in FIG. 6, the outdoor unit 2 includes an outdoor unit control circuit 41.

  In the outdoor unit control circuit 41, various circuits including an outdoor unit MCU (microcontroller unit) 44 are attached to the main board 43, and the outdoor unit MCU 44 is connected to a power source via a power circuit 45 including a rectifier and the like. .

  The outdoor unit MCU 44 is a control unit on the outdoor unit side in the present invention, and includes a CPU, a memory, etc., and the CPU executes a control program stored in the ROM while exchanging data with the ROM and the RAM, thereby compressing the compressor. 8. Controlled components of the outdoor unit 2 including the cylinder number switching valve 11, the cycle switching valve 9, and the electric expansion valve 10 are controlled.

  The outdoor unit MCU 44 is connected to a compressor drive circuit 46 that controls the rotation of the compressor 8, and is further connected to an outdoor fan drive circuit 47 that controls the rotation of the outdoor fan 6.

  The outdoor unit MCU 44 is connected to a valve drive circuit 49 that opens and closes the cylinder number switching valve 11, the cycle switching valve 9, and the electric expansion valve 10.

  Furthermore, a discharge sensor S1 provided on the discharge side of the compressor 8, a suction sensor S2 provided on the suction side, a heat exchanger sensor S3 provided on the outdoor heat exchanger 7 and an outside air temperature sensor S4 are connected to the outdoor unit MCU44. The discharge sensor S1 is the refrigerant temperature discharged from the compressor 8, the suction sensor S2 is the refrigerant temperature sucked into the compressor 8, the heat exchanger sensor S3 is the refrigerant temperature in the outdoor heat exchanger 7, and the outside air temperature sensor S4 is Each of the outdoor temperatures is detected and input to the outdoor unit MCU 44 as temperature information.

  The power supply circuit 45 is connected to the indoor unit 3 side via a wiring 50, and a current sensor 51 is provided in the wiring 50.

As shown in FIG. 7, the valve drive circuit 49 includes a transformer as a DC 12 V drive power supply 60, a PMV drive circuit 67 that outputs a drive pulse to the pulse motor of the electric expansion valve 12, a cycle switching valve 9, and a cylinder switch. And a switching valve drive circuit 61 for switching the valve 11. The changeover valve driving circuit 61, with an energized relay 62 constituting a normally open switch 62A, the ON terminals 63a ₁ and OFF terminal 63a first changeover switch 63A and ON terminal 63b with _{2 1} and OFF terminals 63b ₂ a polarity switching relay 63 as polarity switching means consist of a second changeover switch 63B, the valve selection relay 64 constituting the switch 64A having a ON terminals 64a ₁ and OFF terminals 64a _2, the following DC weak voltage 12V It has a cycle switching valve coil 9C and a cylinder number switching valve coil 11C that operate to perform adsorption and separation when the polarity is switched.

The valve drive circuit 49 is configured such that a PMV drive circuit 67 is directly connected to both terminals of the drive power supply 60 and a switching valve drive circuit 61 is connected in parallel to the PMV drive circuit 67. That is, the first changeover switch 63A of the polarity changeover relay 63 is connected to the positive potential side of the drive power supply 60 via the normally open switch 62A of the energization relay 62, and the polarity of the drive power supply 60 is changed to the negative potential side. A second changeover switch 63B of the changeover relay 63 is connected. ON terminal 63a of the first changeover switch 63A of polarity switching relay 63 ₁ via the resistor 65 is connected to the OFF terminal 63 b ₂ of the second changeover switch 63B, ON terminal 63 b ₁ of the second changeover switch 63B is first It is wired to OFF terminal 63a ₂ of the switch 63A. The change-over switch 64A in the OFF terminals 63a ₂ on the valve selection relay 64 of the first changeover switch 63A is connected, one end connected to the cycle switching valve coil 9C in the OFF terminals 64a ₂ side and cylinder ON terminal 64a ₁ side One end side of the number switching valve coil 11C is connected. The other end of the cycle switch valve coils 9C and cylinder number switch valve coil 11C is connected to the OFF terminal 63 b ₂ of the second change-over switch 63B each polarity switching relay 63. Further, a surge absorbing diode 66 is connected between the wirings between the first selector switch 63A and the second selector switch 63B of the polarity selector relay 63.

  Energization control of the energizing relay 62 that performs opening / closing control of the normally open switch 62A, the polarity switching relay 63 that switches the terminals of the first switching switch 63A and the second switching switch 63B, and the valve selection relay 64 that switches the terminals of the switching switch 64A. Is performed by a command from the outdoor unit MCU44.

  Accordingly, the PMV driving circuit 67 and the valve position switching coil 9C or the cylinder number switching valve coil 11C of the cycle switching valve 9 of the switching valve driving circuit 61 are connected in parallel to the driving power source 60. Therefore, the energization of the coil 9C for switching the valve position of the cycle switching valve 9, the switching of the valve by the polarity switching relay 63, the energization of the coil 11C for switching the valve position of the cylinder number switching valve 11, and the number of input drive pulses The pulse generation of the electric expansion valve (PMV) whose opening degree changes continuously according to is performed by one common drive power supply 60, and the drive power supply is shared.

  FIG. 8 is a control correlation diagram of relays and valves. The left side of the figure shows the correlation of energization of the port of the outdoor unit MCU 44, the polarity switching relay 63, the cycle switching valve coil 9C, and the cylinder number switching valve coil 11C. The right side of the figure shows the correlation between the port of the outdoor unit MCU 44, the valve selection relay 64, and the energized coil.

If the port of the outdoor unit MCU44 is Low, polarity switching relay 63 is turned OFF, the first changeover switch 63A is turned OFF terminal 63a _2, the second changeover switch 63B is connected to the OFF terminal 63 b _2.

If this Saiben selected port is Low, since the valve selection relay 64 is connected to the cycle switch valve coil 9C side connected to cooling and heating switched OFF terminal 64a _2, the cycle switching is performed for one second energized energized relay 62 The valve coil 9C acts in the adsorption direction and maintains that state. Therefore, the refrigeration cycle is maintained in the cooling mode.

When the polarity port is in the Low state and the valve selection port becomes High, the valve selection relay 64 is connected to the ON terminal 64a ₁ and connected to the cylinder number switching valve coil 11C side. When the relay 62 is energized for 1 second, the cylinder number switching valve coil 11C acts in the attracting direction and maintains this state. Therefore, the compressor 8 is maintained in the operation mode with one cylinder.

Also, if you set the polarity switching port High, the polarity switching relay 63 is turned ON, the first changeover switch 63A is in the ON terminal 63a _1, the second changeover switch 63B is connected to the ON terminal 63 b _1. For this reason, the polarity to which the cycle switching valve coil 9C or the cylinder number switching valve coil 11C is energized is reversed.

  Therefore, when the valve selection port is Low at the time described above, when the energization relay 62 is energized for 1 second, the cycle switching valve coil 9C acts in the disengagement direction and maintains that state. Therefore, the refrigeration cycle is switched to the heating mode and the state is maintained.

Further, when the polarity port is High and the valve selection port is High, the valve selection relay 64 is connected to the ON terminal 64a ₁ and is connected to the cylinder number switching valve coil 11C side. Is energized for 1 second, the cylinder number switching valve coil 11C acts in the disengagement direction, and the state is maintained. Therefore, the compressor 8 is maintained in the operation mode with two cylinders.

  FIG. 9 is a sequence control diagram of the relays and valves. From the lower stage to the upper stage, the drive pulse issued from the PMV drive circuit 44 to the pulse motor of the electric expansion valve 12, the control signal to the valve selection relay 64, and the polarity switching relay 63. The sequence of the control signal and the control signal to the energizing relay are shown. As shown in this figure, in the normal state, all the power supply from the drive power supply is supplied to the PMV drive pulse, and only when the switching valve is switched, the PMV drive pulse is stopped and the power supply to the energizing relay side is performed. The control which performs is performed. Specifically, when a valve switching operation signal is output from the outdoor unit MCU, a stop pulse is sent to the PMV drive circuit during transmission of the PMV drive pulse, and the pulse transmission is stopped for 5 seconds. At that time, a signal is sent Low or High to the polarity switching port and the valve selection port, the polarity switching relay 63 and the valve selection relay 64 are set to a predetermined mode, and the energization relay is turned on for 1 second after 2 seconds to switch the valve. After that, the state is maintained for 2 seconds, and then a control is performed to send a start pulse to the PMV drive circuit and resume transmission of the PMV drive pulse.

  Next, operation | movement of the refrigerating-cycle apparatus of this embodiment is demonstrated.

  For example, a case where an automatic operation capable of a cooling cycle operation and a heating cycle operation is performed will be described.

  As shown in FIGS. 6 and 7, when a desired indoor temperature is set by a remote controller or the like and an automatic operation is operated, a designated automatic operation command is input to an indoor control circuit disposed in the indoor unit 3, An operation mode such as a cooling operation or a heating operation is set according to a condition such as a difference between the room temperature and a set temperature, and an operation signal based on the set mode is transmitted from the control circuit on the indoor unit 3 side to the outdoor unit 2. In response to a command from the outdoor unit MCU 44 of the outdoor unit control circuit 41 sent to the outdoor unit control circuit 41, operations such as an outdoor unit side refrigeration cycle circuit and a compressor operating mode based on the set operation mode are executed.

  For example, when the room temperature is higher than the set temperature, the cooling mode is set and the operation is started.

As shown in FIG. 7 and FIG. 8, the outdoor unit MCU 44 that has received an instruction that the cooling cycle operation is required by the input of the indoor temperature information has the polarity switching port of the outdoor unit MCU 44 at Low, and the polarity switching relay 63, the first and second change-over switches 63A, 63B are connected to the OFF terminals 63a ₂ , 63b ₂ , the valve selection relay 64 is connected to the OFF terminal 64a ₂ , and the energizing relay 1 As shown in FIGS. 7 and 8, a current flows in a direction in which the cycle switching valve coil 9C is adsorbed, and the valve body is maintained in a state where the refrigeration cycle can be cooled.

  Note that this operation is omitted when the cooling cycle operation is performed in advance and the polarity switching relay 63 and the valve selection 64 are waiting in the OFF state.

On the other hand, in the normal operation, the valve body is in the detached state, and the normal cooling operation using the _two cylinders 23a ₂ 3B of the compressor 8 as shown in FIG. 4 is possible.

When the cooling operation indicated by the solid line in FIG. 1 is started, in the normal operation using the _two cylinders 23a 23B of the compressor 8, the cylinder number switching valve 11 is connected to the second connection. The mouth and the third connection port are held in communication. The gas refrigerant that has returned to the accumulator 28 is divided into two by the accumulator 28, one refrigerant gas is directly sucked into the first cylinder 23 </ b> A, and the other refrigerant gas passes through the cylinder number switching valve 11 to the second cylinder 23 </ b> B. The first cylinder and the second cylinder are compressed, and high-pressure gas is discharged from the discharge pipe 30 through the sealed container 22.

  The high-pressure gas discharged from the discharge pipe 30 is cooled by the outdoor heat exchanger 7 and becomes liquid refrigerant. The liquid refrigerant is decompressed by the electric expansion valve (PMV) 12 and controlled to a required flow rate, and then the indoor heat exchanger 13. The air flows into the interior, evaporates and vaporizes, absorbs heat from the outside air, cools the surrounding air, and blows the cooling air into the room by the indoor fan 14 to cool the room.

  On the other hand, the gas refrigerant evaporated and gasified in the indoor heat exchanger 13 is sucked into the first cylinder 23A and the second cylinder 23B via the cycle switching valve 9 and the cylinder number switching valve 11.

  During this cooling operation, if the amount of liquid refrigerant flowing into the indoor heat exchanger 13 is too small because the opening of the electric expansion valve 12 is too narrow, a large amount of heat is absorbed from the outside air by the insufficient refrigerant. In some cases, overheating may occur.

  Therefore, the compressor intake temperature sensor S2 detects the refrigerant overheating state, inputs the information to the outdoor unit MCU 44, and based on the valve control signal from the outdoor unit MCU 44, the PMV drive circuit 67 provided in the valve drive circuit 49 A control pulse is given to the electronic expansion valve 12 by the generated drive pulse to open and close it by a predetermined degree of opening to control the refrigerant flow rate.

  As shown in FIG. 9, an opening degree adjustment command for the electric expansion valve 12 is issued from the outdoor unit MCU 44, and as shown by “PMV in operation” in FIG. 9, the electric expansion valve drive is driven by the pulse motor of the electric expansion valve 12. The drive pulse generated by the circuit is input, the opening degree of the electric expansion valve 12 is adjusted, and the refrigerant flow rate is appropriately controlled.

  When the normal cooling operation is continued and the room temperature reaches a desired temperature, the outdoor unit MCU 44 determines to perform the energy saving operation with a small capacity based on the temperature information from the room temperature sensor provided in the indoor unit 3.

  When the outdoor unit MCU 44 determines that the energy saving operation is to be performed, an operation for switching to the single cylinder operation of the compressor 8 is performed, and the sequence shown in FIG. 9 is executed.

  During the valve switching operation by the switching valve drive circuit 61, no pulse is transmitted from the outdoor unit MCU 44 to the PMV drive circuit 67, and the throttle and opening operations of the electric expansion valve 12 are stopped.

The outdoor unit MCU44 is High valve selected port, the outdoor unit MCU44 transmits a drive signal for switching the valve selection relay 64 to the valve drive circuit 49, connects the changeover switch 64A of the valve selected relay 64 ON terminal 64a ₁ To the state.

  The valve selection relay 64 is set for 5 seconds, 2 seconds before and after the energization relay 62 is energized for 1 second.

  Also in this case, during the valve switching operation by the switching valve drive circuit 61, the pulse transmission of the PMV drive circuit 67 is not performed from the outdoor unit MCU44, and the opening degree control operation of the electric expansion valve 12 is stopped.

When the valve select relay 64 is connected to the ON terminal 64a _1, the direction of current flows to adsorb the valve on the cylinder number switching valve coil 11C, the small capacity mode operation as shown in FIG. 5 is started.

  When the small capacity mode operation is started, the cycle switching valve 11 is held in a state where the first connection port and the third connection port communicate with each other.

Since the second cylinder 23B communicates with the discharge pipe 30 via the high pressure side pipe 31, the cycle switching valve 11, the buffer muffler 10, and the second suction side pipe 27b, the suction side of the second cylinder 23B has a high pressure. Therefore, the vane 23b ₂ which has been pressed against the second rolling piston 23b ₁ by the pressure difference in the compression chamber of the second cylinder 23B is separated and becomes free.

  In this state, the vanes are attracted and held by the small magnets 23b3 embedded on the back side of the vanes. Since there is no partition by a vane in a cylinder, it will be in an idling state and the compression action in the 2nd cylinder 23B will be in a stop state.

  For this reason, the gas refrigerant that has returned to the accumulator 28 is sucked into only the first cylinder 23A via the first suction side pipe 27a. As a result, since only one cylinder is operated and a small capacity operation is performed, the operation can be continued without repeating the operation stop, and the energy saving operation is performed.

If it is determined that the indoor temperature rises and the cooling load increases and the outdoor unit MCU 44 returns to the normal cooling operation, the outdoor unit MCU 44 uses the valve drive circuit based on the sequence shown in FIG. 9 to perform the normal cooling operation. 49, a driving signal for switching the polarity switching relay 63 is transmitted, the first and second switching switches 63A, 63B of the polarity switching relay 63 are connected to the ON terminals 63a ₁ , 63b ₁ , and the valve selection relay 64 was in a state of change-over switch 64A is connected to the oN terminal 64a _1, flowing direction of the current to disengage the valve body to the cylinder number switching valve coils 11C, to return to normal operation with the two cylinders.

  Further, when the outside air temperature is lowered and the heating operation is performed, or when the cooling operation is finished and the drying operation for removing the condensation attached to the indoor unit is performed, the heating operation by the heating cycle operation is performed. .

When the outdoor unit MCU 44 receives a command to perform the heating operation, the outdoor unit MCU 44 transmits a drive signal for switching the polarity switching relay 63 to the valve drive circuit 49 based on the sequence shown in FIG. 1, the second change-over switch 63A, in a state 63B is connected to the oN terminal _63a 1, 63 b _1, and the valve selected relay 64 in a state where the changeover switch 64A is connected to the OFF terminal 64a _2, and the current flow in the reverse Then, a current in a direction for removing the valve element is passed through the coil 9C of the cycle switching valve 9, and the flow of the refrigerant is changed to the direction indicated by the dotted line in FIG.

  Also in this case, during the valve switching operation by the switching valve drive circuit 61, the pulse transmission of the PMV drive circuit 67 is not performed from the outdoor unit MCU44, and the opening degree control operation of the electric expansion valve 12 is stopped.

  Also in this heating operation, normal operation by two cylinders and small capacity operation by one cylinder are performed by switching the cycle switching valve 9, but the operation of the valve drive circuit 49 is other than the switching of the cycle switching valve 9 described above. Since it is not different from the cooling operation, the description is omitted.

  Since the air conditioner of this embodiment uses a DC weak voltage coil for the cycle switching valve 9 and the cylinder number switching valve 11, the conventional air conditioner has a power supply specification (for example, single-phase 100V and Unlike the 200V model), which uses different coils, the same product can be used regardless of the power supply, and standardization with a wide range of air conditioners and refrigerators can be achieved. it can.

  Further, since the cycle switching valve 9 and the cylinder number switching valve 11 adopt a system in which the coil is energized only at the time of switching, it does not require power consumption for holding the valve position during operation and is excellent in energy saving effect. Moreover, since the self-holding type valve using the DC weak voltage coil is used for both the cylinder number switching valve and the cycle switching valve, the energy saving effect is further improved.

  Furthermore, since the drive power supply specifications are the same between models, there is no need to place separate drive sources on the control board, and it is possible to control the operation of two coils by simply switching on the same circuit. Excellent in properties.

  According to the refrigeration cycle apparatus of the present embodiment, the same coil can be used between refrigeration cycle apparatuses having different voltages, and standardization in a refrigeration cycle apparatus over a high range can be achieved. A refrigeration cycle apparatus is realized that is energized only at the time of switching and does not require power consumption for holding the valve position during operation and can save energy.

The conceptual diagram of the refrigerating cycle used for the air conditioner of one Embodiment of this invention. The perspective view which shows the machine room structure of the outdoor unit used for the air conditioner of one Embodiment of this invention. The longitudinal cross-sectional view of the compressor used for the air conditioner of one Embodiment of this invention and provided with the cylinder number switching valve. The conceptual diagram at the time of the normal driving | operation of the refrigerating-cycle apparatus used for the air conditioner of one Embodiment of this invention. The conceptual diagram at the time of the energy saving operation | movement of the refrigerating-cycle apparatus used for the air conditioner of one Embodiment of this invention. The control block diagram of the outdoor unit used for the air conditioner of one Embodiment of this invention. The valve drive circuit diagram used for the air conditioner of one Embodiment of this invention. The control correlation figure of a relay and a valve used for the air conditioner of one Embodiment of this invention. The sequence control figure of a relay and a valve used for the air conditioner of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air conditioner, 2 ... Outdoor unit, 3 ... Indoor unit, 4 ... Housing, 5 ... Machine room, 6 ... Outdoor fan, 7 ... Outdoor heat exchanger, 8 ... Compressor, 9 ... Cycle switching valve, 9C ... Cycle switching valve coil, 10 ... Buffer muffler, 11 ... Cylinder number switching valve, 11C ... Cylinder number switching valve coil, 12 ... Electric expansion valve, 13 ... Indoor heat exchanger, 14 ... Indoor fan, 22 ... Sealed container, 23 ... Compression mechanism section, 23A ... first cylinder constituting the first compression mechanism section, 23B ... second cylinder constituting the second compression mechanism section, 24 ... electric motor section, 25 ... rotating shaft, 25a ... second Bearings 26 ... intermediate partition plate 27a ... first suction side pipe 27b ... second suction side pipe 28 ... accumulator 29 ... low pressure side pipe 29a ... low pressure side communication pipe 30 ... discharge pipe 31 ... high-pressure side piping, 41 ... outdoor unit control times 43 ... Main board 44 ... Outdoor unit MCU 45 ... Power supply circuit 46 ... Compressor drive circuit 47 ... Outdoor fan drive circuit 49 ... Valve drive circuit 60 ... Drive power supply 61 ... Switching valve drive circuit 62 ... Energizing relay, normally open switch 62A, 63 ... polarity switching relay, 63A ... first switching switch, 63a ₁ ... ON terminal, 63a ₂ ... OFF terminal, 63B ... second switching switch, 63b ₁ ... ON terminal, 63b ₂ ... OFF 64, valve selection relay, 64A, changeover switch, 64a ₁ ... ON terminal, 64a ₂ ... OFF terminal, 67 ... PMV drive circuit.

Claims (2)

A compressor having two cylinders that can be used by selectively switching one or two, a cylinder number switching valve that is provided on the suction side of the compressor and that switches between operation of one or two cylinders, and a refrigeration cycle A cycle switching valve that switches the flow of refrigerant during cooling and heating operations, an electric expansion valve that depressurizes the refrigerant and controls the flow rate, a valve drive circuit that drives each of the valves, and valve control for the valve drive circuit In the refrigeration cycle apparatus including a control device that transmits a signal and controls the driving of each valve,
The electric expansion valve is a valve whose valve opening degree is controlled by a drive pulse, and the cylinder number switching valve and the cycle switching valve are self-holding types in which the coil is switched by energizing the coil only during the valve switching operation. Valve,
The valve drive circuit includes one drive power supply, an electric expansion valve drive circuit that is connected to the drive power supply and generates a drive pulse in the electric expansion valve, and is connected to the drive power supply and is connected to the cylinder number switching valve or cycle switching. A switching valve drive circuit for switching the valve,
The control device controls to transmit the drive pulse to the electric expansion valve drive circuit in a normal operation state, and at the time of switching operation of the cylinder number switching valve and the cycle switching valve, the electric expansion valve drive circuit A refrigeration cycle apparatus that transmits a switching drive signal to a switching valve drive circuit in a state where transmission of drive pulses is stopped. Using a self-holding type valve using a DC weak voltage coil for both the cylinder number switching valve and the cycle switching valve, with the electric expansion valve drive pulse of the electric expansion valve drive circuit stopped, 2. The refrigeration cycle apparatus according to claim 1 , wherein the valve switching is performed by generating a polarity switching drive signal in one of the cylinder number switching valve or one coil of the cycle switching valve.

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