Refrigerating air-conditioning apparatus

Abstract

To provide a refrigerating air-conditioning apparatus.SOLUTION: A refrigerating air-conditioning apparatus 1 includes: an invertor circuit 32; first components (e.g., 21a, 21b) to which power is supplied by the invertor circuit 32; second components (e.g., 23a, 23b) connected to the invertor circuit 32; an electrical box 30 that houses at least the invertor circuit 32; first wiring P5A, P5B connecting the inverter circuit 32 and the first components (e.g., 21a, 21b) and disposed at least partially within the electrical box 30; and second wiring P4A, P4B connecting the inverter circuit 32 and the second components (e.g., 23a, 23b). The second wiring P4A, P4B has portions (between 33A and 34A, and between 33B and 34B) that are arranged inside the electrical box 30, and measures are taken to reduce incoming noise for portions (33A-34A, 33B-34B) of the second wiring P4A.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a refrigerating air conditioner.

Background Art

[0002] In refrigerating air conditioners such as air conditioners, it is required that the noise terminal voltage of the product be below a certain noise level. In an up-blow type multi-air conditioner for buildings (for example, VRF (Variable Refrigerant Flow)) having a compressor and a fan motor, a power supply line is connected from an inverter circuit to the fan motor and the compressor motor. However, for example, external noise is superimposed on the power supply wiring to the fan motor, which may deteriorate the noise level of the noise terminal voltage of the product. As the above noise source, various electrical components can be considered, but the power supply wiring itself for driving the fan motor and the compressor motor may become a noise source. Generally, by storing electrical components in an electrical box, the influence of noise radiated from them can be shielded, and the influence of noise outside the electrical box can be suppressed to a certain extent. However, there is still a need to develop a technology that can improve the noise level of the noise terminal voltage of the product with minimal countermeasures.

[0003] So far, as a noise countermeasure, for example, Japanese Patent Application Laid-Open No. 7-095791 (Patent Document 1) is known. Patent Document 1 relates to a technology for processing noise generated by a chopping voltage supplied to the winding of a brushless motor of an air conditioner, and discloses a technology for an air conditioner that prevents malfunction or circuit breakage due to the noise. More specifically, Patent Document 1 discloses a configuration in which, when laying a wiring connecting a brushless motor and a brushless motor control means in an outdoor unit of an air conditioner, the wiring for supplying voltage to the winding of the brushless motor 1 is not bundled with other wirings. However, there is still a need to further improve the noise level of the noise terminal voltage of the product.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide a refrigerating and air-conditioning apparatus capable of reducing external noise that can be superimposed on wiring from an inverter circuit to other components with a minimum countermeasure and improving the noise level of the noise terminal voltage of the entire apparatus.

Means for Solving the Problems

[0006] In the present disclosure, in order to solve the above problems, a refrigerating and air-conditioning apparatus having the following features is provided. The refrigerating and air-conditioning apparatus includes an inverter circuit, a first component powered by the inverter circuit, a second component connected to the inverter circuit, and an electric box that houses at least the inverter circuit. The refrigerating and air-conditioning apparatus further includes a first wiring that connects the inverter circuit and the first component and is disposed at least partially inside the electric box, and a second wiring that connects the inverter circuit and the second component. Here, the second wiring has a portion disposed inside the electric box, and a countermeasure for reducing incident noise is applied to the portion of the second wiring.

Effects of the Invention

[0007] With the above configuration, it is possible to reduce external noise that can be superimposed on wiring from the inverter circuit to other components with a minimum countermeasure and improve the noise level of the noise terminal voltage of the entire apparatus.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments of the present invention are not limited to the specific embodiments described below. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0010] The present disclosure is directed to a refrigerating and air-conditioning apparatus. A refrigerating and air-conditioning apparatus according to an embodiment of the present invention includes an inverter circuit, a first component (e.g., a compressor motor or a fan motor) powered by the inverter circuit, a second component (e.g., a fan motor or a compressor motor) connected to the inverter circuit, and an electric box that houses at least the inverter circuit. The refrigerating and air-conditioning apparatus further includes a first wiring that connects the inverter circuit and the first component and is disposed at least partially within the electric box, and a second wiring that connects the inverter circuit and the second component. In this configuration, the second wiring has a portion disposed within the electric box, and a countermeasure against incoming noise is taken for the portion of the second wiring.

[0011] With the above configuration, it is possible to reduce external noise derived from the first wiring that can overlap with the wiring from the inverter circuit to the second component within the electric box, and improve the noise level of the noise terminal voltage of the entire apparatus. At that time, only a minimum countermeasure needs to be taken for the portion of the second wiring disposed within the electric box, and it is possible to reduce the cost of the refrigerating and air-conditioning apparatus.

[0012] In a preferred embodiment, the first component is a compressor motor or a fan motor disposed outside the electric box. The wiring for supplying power to the compressor motor or the fan motor has relatively large power, and by taking noise countermeasures for the wiring that is easily affected corresponding to such wiring, a large effect can be obtained efficiently. In a more preferred embodiment, the first component is a compressor motor disposed outside the electric box. The wiring for supplying power to the compressor motor has larger power than the wiring for supplying power to the fan motor, and a larger effect can be obtained more efficiently.

[0013] In certain embodiments, the second component is a fan motor or a compressor motor that is disposed outside the electrical box and powered by an inverter circuit. By preferentially implementing countermeasures to reduce incoming noise with respect to power lines that have wiring portions outside the electrical box and whose product noise terminal voltage is likely to deteriorate when external noise is superimposed, a large effect can be efficiently obtained. In a more preferred embodiment, the second component is a fan motor that is disposed outside the electrical box and powered by an inverter circuit. Since the wiring for power supply to the compressor motor has a greater power than the wiring for power supply to the fan motor, a large effect can be efficiently obtained by preferentially implementing countermeasures to reduce incoming noise with respect to power lines that are more susceptible to the influence of wiring with greater power.

[0014] In other specific embodiments, the second wiring may be at least one of the plurality of power lines connected to a terminal block, a filter, a DC reactor, and a control board, each of which is a second component housed in the electrical box. By preferentially implementing countermeasures to reduce incoming noise with respect to power lines that are susceptible to influence, a large effect can be efficiently obtained.

[0015] In one or more embodiments, in addition to the second wiring, countermeasures to reduce incoming noise may be applied to the portion of at least one of the signal lines between the plurality of circuits included in the inverter circuit, the signal line between the inverter circuit and the control board, the signal line between the control board and one or more sensors or actuators, and the signal line between the inverter circuit and the high-voltage cut-off device within the electrical box. Even for such signal lines, by taking minimal countermeasures, an effect of reducing the noise level can be expected.

[0016] In a preferred embodiment, the first component is a compressor motor disposed outside the electrical box, and the second component is a fan motor disposed outside the electrical box and powered by an inverter circuit. With the above configuration, it is possible to reduce the external noise derived from the first wiring to the compressor motor, which is a wiring for power supply with greater power that may overlap with the wiring for power supply from the inverter circuit to the fan motor inside the electrical box, and significantly improve the noise level of the noise terminal voltage of the entire device. At that time, only minimal countermeasures are required, and it is possible to reduce the cost of the refrigeration and air conditioning device.

[0017] In a specific embodiment, the second wiring starts from the terminals of the inverter circuit, is drawn out of the electrical box below the electrical box, passes outside the electrical box, and is connected to the fan motor. The wiring from the electrical box to the outside often exits from the lower side of the electrical box for water trapping, and as a result, it tends to be routed over a long distance until it is connected to the fan motor. With the above configuration, by simplifying the noise reduction measures for the portion outside the electrical box that occupies most of the second wiring, cost reduction is expected.

[0018] In a preferred embodiment, the countermeasure for reducing incoming noise is twisting or shielding the cable. More preferably, the countermeasure for reducing incoming noise is twisting. By twisting, it is possible to reduce noise for a part of the second wiring with high cost-effectiveness.

[0019] In a preferred embodiment, the second wiring includes the portion disposed inside the electrical box and one or more other portions disposed outside the electrical box, and the one or more other portions are not subjected to either twisting or shielding cable. Since twisting and shielding cable for one or more other portions disposed outside the electrical box are omitted, the cost is reduced.

[0020] In one or more embodiments, the inverter circuit includes one or more inverter units, each having one or more output terminals for driving a compressor and one or more output terminals for driving a fan.

[0021] In a particular embodiment, the refrigerating and air-conditioning apparatus is an air conditioner. In a particular embodiment, the inverter circuit, the first component, the second component, and the electric box housing the inverter circuit are arranged in the outdoor unit of the air conditioner.

[0022] Hereinafter, with reference to FIGS. 1 to 4, an air conditioner as an example of a refrigerating and air-conditioning apparatus according to an embodiment of the present invention will be described.

[0023] FIG. 1 is a schematic diagram showing an air conditioner 1 including one or more indoor units 10 and an outdoor unit 20 according to an embodiment of the present invention. The air conditioner 1 is a device that performs air conditioning by circulating a refrigerant in a refrigeration cycle (heat pump cycle). As shown in FIG. 1, the air conditioner 1 includes one or more indoor units 10 (10a, 10b...) installed indoors (the space to be air-conditioned) and an outdoor unit 20 installed outdoors.

[0024] In FIG. 1, two indoor units 10a and 10b are shown as the plurality of indoor units 10. However, the number of indoor units 10 is not particularly limited, and may be one, or three or more. Also, the number of outdoor units 20 is not particularly limited, and may be two or more.

[0025] The one or more indoor units 10 and the outdoor unit 20 are connected via a refrigerant pipe 2. The air conditioner 1 may include an operating device for communicating with the indoor unit 10 wirelessly or wiredly and operating the indoor unit 10 in the room where the indoor unit 10 is installed.

[0026] In the example shown in FIG. 1, the air conditioner 1 shows an embodiment of a multi-split air conditioner for buildings equipped with an up-blow type outdoor unit 20 as an example. However, in the embodiments of the present invention, the form of the air conditioner 1 is not particularly limited.

[0027] FIG. 2 is a diagram showing a configuration example of the air conditioner 1 according to an embodiment of the present invention. Each indoor unit 10 and the outdoor unit 20 are connected by two pipes 2a and 2b through which a refrigerant as a heat medium circulates. As the refrigerant, for example, hydrofluorocarbons such as R410a and R32 are used. Further, the indoor unit 10 and the outdoor unit 20 are connected by a communication line for communicating with each other. Note that the indoor unit 10 and the outdoor unit 20 are not limited to being wired-connected by a communication line, and may be wirelessly connected.

[0028] During operation, the indoor unit 10 takes in indoor air, exchanges heat between the taken-in air and the refrigerant supplied from the outdoor unit 20, blows out the cooled air or the warmed air, and cools or warms the interior to the set temperature. For this purpose, the indoor unit 10 includes an indoor heat exchanger 11 that exchanges heat between indoor air and the refrigerant, and an indoor fan 12 that takes in indoor air to the indoor heat exchanger 11 and blows out the air heat-exchanged by the indoor heat exchanger 11.

[0029] The indoor unit 10 includes a room temperature sensor 13 that detects the indoor temperature in order to notify the outdoor unit 20 of the indoor temperature. Further, the indoor unit 10 includes an indoor expansion valve 14 that expands the refrigerant and adjusts the flow rate of the refrigerant flowing through the indoor heat exchanger 11.

[0030] When the indoor unit 10 is used for cooling, the indoor heat exchanger 11 functions as an evaporator, and the refrigerant flows into the indoor heat exchanger 11 in a two-phase flow state (liquid refrigerant) in which liquid and gas are mixed. The refrigerant exchanges heat with the air taken in by the indoor fan 12 in the indoor heat exchanger 11, so that the liquid component evaporates, and the refrigerant is discharged from the indoor heat exchanger 11 as a gas refrigerant and sent to the outdoor unit 20.

[0031] The outdoor unit 20 is activated upon receiving a designation from the control device and starts operating in the operation mode set by a remote controller or the like. The operation modes include a cooling mode, a heating mode, a ventilation mode, etc. The outdoor unit 20 controls the temperature, pressure, flow rate, etc. of the refrigerant according to the set temperature, the indoor temperature, the pipe temperature, etc. Also, the outdoor unit 20 stops operating upon receiving a command from the control device.

[0032] The outdoor unit 20 is connected to one or more indoor units 10 (10a to 10c in FIG. 2) via pipes 2a and 2b and circulates the refrigerant. For this purpose, it is equipped with a compressor 21 for circulating the refrigerant. The refrigerant gas compressed by the compressor 21 exchanges heat with the air taken in by the outdoor fan 23 in the outdoor heat exchanger 22 and becomes a high-pressure liquid refrigerant. Also, the outdoor unit 20 is equipped with a four-way valve 25 for reversing the direction in which the refrigerant flows in order to enable heating operation. The outdoor expansion valve 24 is provided to turn the high-pressure refrigerant into a low-temperature and low-pressure refrigerant and to adjust the flow rate of the refrigerant during heating.

[0033] The flow rate of the refrigerant can be changed by varying the operating frequency of the compressor 21. When the operating frequency of the compressor 21 is increased, the refrigerant supply amount increases and the air conditioning capacity increases. Conversely, when the operating frequency of the compressor 21 is decreased, the refrigerant supply amount decreases and the air conditioning capacity decreases.

[0034] The outdoor unit 20 is equipped with an outdoor unit control device 26. The outdoor unit control device 26 is equipped with an inverter circuit for driving the motor of the compressor 21 and the motor of the outdoor fan 23. The outdoor unit control device 26 also controls the operating frequency of the compressor 21, the rotational speed of the outdoor fan 23, and the opening degree of the outdoor expansion valve 24 based on the respective indoor temperatures detected by the room temperature sensors 13a to 13c of the plurality of indoor units 10a to 10c, the set temperature, the pipe temperature detected by the sensors within the outdoor unit 20, and the operation mode. Also, it switches the four-way valve 25 according to the set operation mode. The outdoor unit control device 26 is housed in the electric box 30. The electric box 30 is typically made of metal.

[0035] FIG. 3 is a block diagram showing the arrangement of components in the electric box 30 of the outdoor unit 20 of the air conditioner 1 according to an embodiment of the present invention. As shown in FIG. 3, in the electric box 30, as components constituting the control device 26, there are provided a terminal block 31, one or more inverter boards (circuits) 32, one or more noise filters 35, one or more DC reactors (DCLs) 36, and a control board 37. In the embodiment shown in FIG. 3, two inverter boards (first inverter board 32A, second inverter board 32B), two noise filters (first noise filter 35A, second noise filter 35B), and two DCLs (first DCL 36A, second DCL 36B) are accommodated in the electric box 30.

[0036] Power is supplied from the terminal block 31 to which a commercial voltage from the outside is connected, to the noise filters 35A and 35B by wiring (power line) P1. From the noise filters 35A and 35B, power (primary side three-phase alternating current (RST)) is further supplied to the input terminals of the inverter boards 32A and 32B by wiring (power lines) P2A and P2B. The noise filters 35A and 35B are further connected to the power supply circuit in the inverter boards 32A and 32B via wiring (power lines) P3A and P3B, and to the input terminal of the control board 37 via wiring (power line) P6. One output terminal ((secondary side three-phase alternating current (UVW))) of the inverter boards 32A and 32B accommodated in the electric box 30 and the fan motors 23a and 23b outside the electric box 30 are connected by wiring (power lines) P4A and P4B. Similarly, the other output terminal ((secondary side three-phase alternating current (UVW))) of the inverter boards 32A and 32B accommodated in the electric box 30 and the compressor motors 21a and 21b outside the electric box 30 are connected by wiring (power lines) P5A and P5B. The inverter boards 32A and 32B accommodated in the electric box 30 and the first DCLs 36A and 36B in the electric box 30 are connected by wiring (power lines) P6A and P6B.

[0037] In the configuration shown in FIG. 3, the two inverter boards 32A and 32B are connected via a signal line S1. External sensors 40 and actuators 41 are respectively connected to the control board 37 via a signal line S2 and a signal line S3. The sensors 40 may include a low-pressure side pressure sensor, a high-pressure side pressure sensor, a temperature sensor, and the like. The actuators 41 may include an electromagnetic valve, an expansion valve, and the like. Further, an external high-pressure cutoff device 42 is connected to the control board 37 via a signal line S4. Further, the inverter board 32B is connected to the control board 37 via a signal line S5.

[0038] As described above, when the electrical components are wired by the power lines P1 to P7 and the signal lines S1 to S5, in the air conditioner 1, it is required that the noise terminal voltage of the product be below a certain noise level. By housing these electrical components (32A, 32B, 35A, 35B, 36A, 36B, 37) in the metal electrical box 30, the influence of the noise radiated from them can be shielded, and the influence of the noise outside the electrical box 30 can be suppressed. On the other hand, inside the electrical box 30, for example, external noise may be superimposed on the power lines P4A, P4B, P5A, P5B to the fan motors 23a, 23b and the compressor motors 21a, 21b, which may deteriorate the noise level of the noise terminal voltage of the product. As the noise source of the external noise, various electrical components can be considered, but in particular, the power lines P4A, P4B, P5A, P5B for driving the fan motors 23a, 23b and the compressor motors 21a, 21b may be the noise source.

[0039] Therefore, in the air conditioner 1 according to the embodiment of the present invention, a first wiring that connects the inverter board 32 in the electric box 30 and a first component powered by the inverter board 32 and is at least partially disposed in the electric box 30, and a second wiring that connects the inverter board 32 and a second component and can be affected by external noise from the wiring disposed in the electric box 30 are provided. In this configuration, a countermeasure for reducing incoming noise is adopted for the portion of the second wiring disposed in the electric box 30. Thereby, with a minimum countermeasure, external noise that may be superimposed on the wiring from the inverter board 32 to the second component that may occur in the electric box 30 is reduced, and the noise level of the noise terminal voltage of the entire apparatus is improved.

[0040] In the embodiment shown in FIG. 3, the compressor motors 21a and 21b outside the electric box 30 correspond to the first components, and the power lines P5A and P5B that connect the inverter boards 32A and 32B and the compressor motors 21a and 21b correspond to the first wiring that is at least partially disposed in the electric box 30. In the embodiment shown in FIG. 3, the fan motors 23a and 23b outside the electric box 30 correspond to the second components, and the power lines P4A and P4B that connect the inverter boards 32A and 32B and the fan motors 23a and 23b correspond to the second wiring.

[0041] In the embodiment shown in FIG. 3, a relay connector 34A is provided in the middle of the power line P4A that connects the connector 33A of the inverter board 32A and the first fan motor 23a. The relay connector 34A is configured to reconnect and separate the wiring portion located inside the electric box 30 between the connector 33A of the inverter board 32A and the relay connector 34A and the wiring portion located outside the electric box 30 between the relay connector 34A and the first fan motor 23a. A countermeasure for reducing incoming noise is taken for the wiring portion of the power line P4A disposed inside the electric box 30 between the inverter board 32A and the relay connector 34A.

[0042] Here, the countermeasure for reducing incoming noise is preferably twisting or shielding. From the perspective of cost-effectiveness, in a more preferred embodiment, the countermeasure for reducing incoming noise is twisting. That is, the wiring portion disposed within the electric box 30 is twisted wiring, while one or a plurality of other wiring portions disposed outside the electric box 30 are neither twisted nor shielded with a shield cable.

[0043] On the other hand, the countermeasure for reducing incoming noise is limited to the wiring portion between the inverter board 32A of the power line P4A and the relay connector 34A, and the wiring portion located outside the electric box 30 between the relay connector 34A and the first fan motor 23a is neither twisted nor shielded.

[0044] Similarly, a relay connector 34B is provided on the power line P4B connecting the connector 33B of the inverter board 32B and the second fan motor 23b. The relay connector 34B is configured to reconnect and disconnectably connect the wiring portion located within the electric box 30 between the connector 33B of the inverter board 32B and the relay connector 34B and the wiring portion located outside the electric box 30 between the relay connector 34B and the second fan motor 23b. For the wiring portion disposed within the electric box 30 between the inverter board 32B and the relay connector 34B of this power line P4B, a countermeasure for reducing incoming noise (twisting, shielding with a shield cable) is implemented. On the other hand, the countermeasure for reducing incoming noise is limited to the wiring portion between the inverter board 32B and the relay connector 34B of the power line P4B, and the wiring portion located outside the electric box 30 between the relay connector 34B and the second fan motor 23b is neither twisted nor shielded.

[0045] The effect of twisting is not an improvement to the characteristics of a single item, but rather an increased cancellation effect of incoming external noise. When the signal wire pairs are parallel, a magnetic field is generated by the electromagnetic waves of the incoming noise, which generates an electromotive force, generating an induced current and becoming a noise source. On the other hand, by twisting the signal wires, the electromotive forces act in opposite directions with each twist, which causes the electromotive forces to cancel out the noise, reducing the impact of incoming noise.

[0046] In this way, by applying the incoming noise reduction measures (twisting) to the wiring portions of the power lines P4A, P4B located inside the electrical box 30, the influence of the external noise originating from other power lines inside the electrical box 30 on the wiring to the fan motor 23a can be cancelled out, improving the noise level. By limiting the areas where the incoming noise reduction measures are applied to only the areas of the power lines P4A, P4B located inside the electrical box 30 that are susceptible to incoming external noise, it is not necessary to apply the incoming noise reduction measures to the entire wiring, and it is possible to obtain the expected effect with a minimum of measures. It is also possible to improve the noise level of the product's noise terminal voltage without adding any parts.

[0047] Please refer to Figure 3 for the wiring part. Directly The above describes a configuration for reducing incoming noise, more specifically, a configuration for using twisted or shielded cables. However, in addition to the above, other noise countermeasures may be used. For example, a general noise countermeasure such as a ring core may be attached around a specific wiring.

[0048] Fig. 4 is a schematic diagram showing the electrical box and wiring layout inside an outdoor unit of a top-blow type air conditioner according to an embodiment of the present invention. Fig. 4(A) shows the internal layout when viewed from the side of the outdoor unit, and Fig. 4(B) shows the internal layout when viewed from the front of the outdoor unit. In Fig. 4, the white thick black lines indicate the wiring parts inside the electrical box 30, the thick black lines indicate the wiring parts outside the electrical box 30 that do not overlap with the electrical box 30, and the gray dashed lines indicate the wiring parts outside the electrical box 30 that are hidden by the electrical box 30.

[0049] As shown in FIG. 4, the power lines P4A and P4B from the inverter boards 32A and 32B to the fan motors 23a and 23b originate from the connectors 33A and 33B (output terminals) of the inverter boards 32A and 32B, are drawn out of the electric box 30 below the electric box 30 for water trap, go around the back side of the electric box 30, pass from the bottom to the top outside the electric box 30, and are connected to the fan motors 23a and 23b. Therefore, in the top-blow type outdoor unit 20, the wiring to the fan motors 23a and 23b has a long wiring length due to the product structure. In particular, the length outside the electric box 30 is considerably longer than the length of the wiring inside the electric box 30. Also, due to the product configuration, the wiring to the fan motors 23a and 23b is likely to be close to the wiring to the compressor motors 21a and 21b inside the electric box 30 and is susceptible to external noise, mainly the switching noise on the compressor 21 side. Therefore, the wiring configuration inside the electric box according to the embodiment of the present invention is not limited to this, but can be particularly preferably applied to the outdoor unit of a top-blow type air conditioner.

[0050] By housing the electrical components in the metal electric box 30, the electric box functions as a shield against the influence of the noise radiated from them, suppressing the influence of the noise outside the electric box 30. Also, by twisting the wiring to the fan motors 23a and 23b inside the electric box 30, which is likely to be close to the noise source (for example, the power lines to the compressor motors 21a and 21b), the noise current generated by the external noise from other electrical components and wiring can be canceled out, and the noise level of the noise terminal voltage of the product can be improved with high cost-effectiveness.

[0051] In the embodiments described with reference to FIGS. 3 and 4, it has been described that there are two systems of the compressor 21 and the outdoor fan 23, respectively, and two inverter boards each having one output terminal for driving the compressor and one output terminal for driving the fan are provided. However, the configuration of the inverter board (circuit) is not limited to the form shown in FIGS. 3 and 4. For example, when there is one system of the compressor 21 and two systems of the outdoor fan 23, one inverter board having one output terminal for driving the compressor and two output terminals for driving the fans may be provided. Also, when there are two systems of the compressor 21 and the outdoor fan 23, respectively, one inverter board having two output terminals for driving the compressors and two output terminals for driving the fans may be provided.

[0052] In the embodiments described above, the first component that generates noise in the wiring portion inside the electrical box 30 corresponds to the compressor motors 21a and 21b outside the electrical box 30, and the second component having wiring that can be affected by external noise corresponds to the fan motors 23a and 23b outside the electrical box 30. However, the first component that generates noise from the wiring and the second component having wiring for which countermeasures for reducing incoming noise are taken in part due to the influence of noise are not limited to those shown in FIGS. 3 and 4. Inside the electrical box 30, any power line can be a noise source, and any power lines P1 to P7 and any signal lines S1 to S5 in the electrical box 30 may be affected by noise, and countermeasures for reducing incoming noise may be taken for the wiring portion inside the electrical box 30.

[0053] FIG. 5 is a block diagram showing the arrangement of components inside the electrical box 30 of the outdoor unit 20 of the air conditioner 1 according to another embodiment of the present invention. Another embodiment shown in FIG. 5 also has the same configuration as the embodiment shown in FIG. 3, and will be described mainly focusing on the differences below. Inside the electrical box 30, two inverter boards 32A and 32B, two noise filters 35A and 35B, and two DCLs 36A and 36B are housed.

[0054] In another embodiment shown in FIG. 5, the fan motors 23a, 23b outside the electric box 30 correspond to the first component, and the power lines P4A, P4B connecting the inverter boards 32A, 32B and the fan motors 23a, 23b correspond to the first wiring disposed at least partially inside the electric box 30. In the embodiment shown in FIG. 5, the compressor motors 21a, 21b outside the electric box 30 correspond to the second component, and the power lines P5A, P5B connecting the inverter boards 32A, 32B and the compressor motors 21a, 21b correspond to the second wiring.

[0055] In another embodiment shown in FIG. 5, relay connectors 39A, 39B are provided in the middle of the power lines P5A, P5B connecting the connectors 38A, 38B of the inverter boards 32A, 32B and the compressor motors 21a, 21b. The relay connectors 39A, 39B are configured to reconnect and separate the wiring portion located inside the electric box 30 between the connectors 38A, 38B of the inverter boards 32A, 32B and the relay connectors 39A, 39B and the wiring portion located outside the electric box 30 between the relay connector 39A and the compressor motor 21a, 21b. Anti-flying noise measures are taken for the wiring portion disposed inside the electric box 30 between the inverter boards 32A, 32B and the relay connectors 39A, 39B of the power lines P5A, P5B. On the other hand, the anti-flying noise measures are limited to the wiring portion between the inverter boards 32A, 32B and the relay connectors 39A, 39B of the power lines P5A, P5B, and no anti-flying noise measures are taken for the wiring portion located outside the electric box 30 between the relay connectors 39A, 39B and the compressor motors 21a, 21b.

[0056] Thus, by twisting the wiring portions located within the electrical box 30 of the power lines P5A and P5B, the influence of external noise originating from other power lines within the electrical box 30 on the wiring to the compressor motor 21a can be canceled out, and the noise level of the product can be improved. By limiting the location of the twisting to only the area within the electrical box 30 of the power lines P5A and P5B where external noise is likely to fly in, it is not necessary to twist the entire wiring, and the desired effect can be obtained with a minimum amount of twisting. Also, it becomes possible to improve the noise level of the noise terminal voltage of the product without adding components.

[0057] As described above, any power line can become a noise source, and any power lines P1 to P7 or signal lines S1 to S5 in the electrical box 30 may be affected by noise. Therefore, the second wiring may be at least one of the power lines P1, P2, P3, P6, and P7 that are connected to the terminal block 31, filter 35, DC reactor 36, and control board 37, respectively, as the second components housed in the electrical box 30. Also, in addition to these second wirings, noise reduction measures may be taken for at least a part within the electrical box 30 of at least one of the signal lines S1 between the plurality of circuits included in the inverter board 32, the signal lines S2 and S3 between the control board 37 and one or more sensors 40 or actuators 41, the signal line S4 between the inverter board 32 and the high-voltage cut-off device 42, and the signal line S5 between the inverter board 32 and the control board 37.

[0058] Hereinafter, with reference to FIGS. 6 and 7, the advantages of reducing the noise level of the noise terminal voltage of the outdoor unit 20 of the air conditioner 1 by twisting will be described. FIG. 6 is a graph showing the measurement results of the noise terminal voltage of the outdoor unit of an air conditioner without twisting the wiring within the electrical box. FIG. 7 is a graph showing the measurement results of the noise terminal voltage of the outdoor unit 20 of the air conditioner 1 according to the embodiment of the present invention with twisting of the wiring within the electrical box 30.

[0059] Figures 6 and 7 are the spectral analysis results of measurement data where the horizontal axis represents frequency and the vertical axis represents the noise level. Figures 6(A) and 7(A) are graphs of the quasi-peak value (Q.Peak), and Figures 6(B) and 7(B) are graphs of the average value (MEAN). Also, the measurements in Figures 6 and 7 show the measurement results when a part (the section between the relay connectors 34A and 34B from the connectors 33A and 33B in Fig. 3) of the wiring P4A and P4B connecting the inverter substrates 32A, 32B and the fan motors 23a, 23b in the electrical box 30 is not twisted (Fig. 6) and when it is twisted (Fig. 7). Comparing Figures 6 and 7, it can be seen that the noise level values are generally smaller and improved between 0.15 MHz and 10 MHz.

[0060] The measurement results shown in Fig. 7 demonstrate that in an embodiment where the first component is the compressor motors 21a, 21b arranged outside the electrical box 30 and the second component is the fan motors 23a, 23b arranged outside the electrical box 30, the noise level of the noise terminal voltage can be reduced. Although the impedance characteristics of the wiring were also measured, no significant difference was found in the attenuation characteristics within the range of 0.5 MHz to 190 MHz described above. That is, it was confirmed that there is no difference in the impedance characteristics / attenuation characteristics of the single wiring in terms of the effect of wiring twisting.

[0061] As described above, according to the embodiment of the present invention, it is possible to provide an air conditioner that can reduce the external noise that can be superimposed on the wiring from the inverter circuit to other components with minimal countermeasures and improve the noise level of the noise terminal voltage of the entire device.

[0062] In the embodiments described above, an air conditioner including the electric box according to the present embodiment has been described as an example. However, the electric box according to the present embodiment is not limited to that of the air conditioner. In other embodiments, the configuration of the present invention may be applied to a refrigerated air conditioning apparatus other than the air conditioner. Here, the refrigerated air conditioning apparatus is also called a refrigerated air conditioning device, and the refrigerated air conditioning device collectively refers to devices using a refrigerant and a refrigeration cycle, such as a refrigerator and a freezer, in addition to the above-described air conditioner. More specifically, examples of the refrigerated air conditioning device include the above-described air conditioners such as a package air conditioner and a multi-air conditioner for buildings, heat source devices such as a refrigerator and a chiller unit, business-use refrigerators such as a showcase and a refrigerated refrigerator, a unit cooler, an ice maker, transportation refrigeration devices such as a car air conditioner, and a heat pump water heater.

[0063] Note that the embodiments of the present invention are not limited to the above-described embodiments, and various modifications may be included. For example, the above-described embodiments have been described in detail for easy understanding, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Also, it is possible to add, delete, or replace other configurations for a part of the configuration of each embodiment.

Description of Reference Numerals

[0064] 1... Air conditioner, 2... Refrigerant pipe, 10... Indoor unit, 11... Indoor heat exchanger, 12... Indoor fan, 13... Room temperature sensor, 14... Indoor expansion valve, 20... Outdoor unit, 21... Compressor, 21a, 21b... Compressor motor, 22... Outdoor heat exchanger, 23... Outdoor fan, 23a, 23b... Fan motor, 24... Outdoor reversing valve, 25... Four-way valve, 26... Outdoor control device, 30... Electric box, 31... Terminal block, 32... Inverter board, 33, 38... Connector, 34, 39... Relay connector, 35... Noise filter, 36... DC reactor, 37... Control board, 40... Sensors, 41... Actuators, 42... High-pressure cut-off device

Claims

1. An inverter circuit, a first component powered by the inverter circuit, a second component connected to the inverter circuit, an electrical box housing at least the inverter circuit, a first wiring connecting the inverter circuit and the first component and disposed at least partially within the electrical box, and a second wiring connecting the inverter circuit and the second component A refrigerated air conditioner, comprising: the second wiring has a portion disposed within the electrical box, and a measure for reducing incoming noise is applied to the portion of the second wiring.

2. The refrigerated air conditioner according to claim 1, wherein the first component is a compressor motor or a fan motor disposed outside the electrical box.

3. The refrigerated air conditioner according to claim 2, wherein the second component is a fan motor or a compressor motor disposed outside the electrical box and powered by the inverter circuit.

4. The refrigerated air conditioner according to claim 2, wherein the second wiring is at least one power line among a plurality of power lines connected to a terminal block, a filter, a DC reactor, and a control board, respectively, as the second component housed in the electrical box.

5. In addition to the second wiring, a measure for reducing incoming noise is applied to a portion within the electrical box of at least one signal line among signal lines between a plurality of circuits included in the inverter circuit, signal lines between the inverter circuit and the control board, signal lines between the control board and one or more sensors or actuators, and signal lines between the inverter circuit and a high-voltage cutoff device. The refrigerated air conditioner according to claim 4.

6. The refrigerated air conditioner according to claim 1, wherein the first component is a compressor motor disposed outside the electrical box, and the second component is a fan motor disposed outside the electrical box and powered by the inverter circuit.

7. The refrigerated air conditioner according to claim 6, wherein the second wiring originates from a terminal of the inverter circuit, is drawn out of the electrical box below the electrical box, passes outside the electrical box, and is connected to the fan motor.

8. The refrigerated air conditioner according to claim 1, wherein the measure for reducing incoming noise is twisting or shielding the cable. Claim 9 The second wiring includes a portion disposed inside the electric box and one or more other portions disposed outside the electric box, and the one or more other portions are not subjected to either twisting or shielding cable formation. The refrigerated air conditioner according to claim 8. Claim 10 The inverter circuit includes one or more inverter units each having one or more output terminals for driving a compressor and one or more output terminals for driving a fan. The refrigerated air conditioner according to claim 1.

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