Air conditioner outdoor unit

Abstract

An outdoor unit (1) of an air conditioner comprises: a box-like housing (2) formed from a first metal; a heat exchanger (6) which has at least a portion formed from a second metal having a different spontaneous potential from the first metal, is disposed inside the housing (2), and which is fixed to the housing (2) by way of a non-electrically conductive member; and a capacitive connection metal plate (3) which is formed from the first metal or a third metal that does not cause dissimilar metal contact corrosion with the first metal, and which is disposed inside the housing (2). The capacitive connection metal plate (3) is fixed to the housing (2) and is electrically connected to the housing (2), and is disposed spaced apart from the heat exchanger (6) and is electrically connected to the heat exchanger (6) by way of electrostatic capacitance generated between the heat exchanger (6) and the capacitive connection metal plate (3).

Description

[Technical field]

[0001] The present disclosure relates to an outdoor unit of an air conditioner that includes a housing and a heat exchanger. [Background technology]

[0002] A conventional outdoor unit of an air conditioner is known that includes a box-shaped housing and a heat exchanger disposed inside the housing, the heat exchanger and the housing being made of different metals. The types of metals for the heat exchanger and the housing are selected according to the required characteristics. For example, aluminum is generally used for the heat exchanger that requires high thermal conductivity, and iron is generally used for the housing that requires strength.

[0003] When a heat exchanger and a housing, which are dissimilar metals, are in direct contact with each other and moisture adheres to the contact point, galvanic corrosion occurs in the metal with the lower natural potential. Hereinafter, galvanic corrosion will be simply referred to as corrosion. A known method for preventing corrosion is to indirectly connect the heat exchanger and the housing via a non-conductive material such as resin.

[0004] However, when such a means is used, the heat exchanger and the housing are electrically insulated by the non-conductive member, so that a parasitic capacitance is generated between the heat exchanger and the housing. Then, there is a problem that a voltage change occurs in the parasitic capacitance due to electromagnetic noise generated from an electronic board, a compressor, etc. arranged in the housing, and this voltage change generates further electromagnetic noise. In addition, an air intake port is formed on the back surface of the housing to allow outside air to flow in, and the heat exchanger is arranged in a position facing the air intake port to exchange heat with the outside air. The electromagnetic noise is radiated from between the heat exchanger and the housing to the outside of the housing through the air intake port.

[0005] In order to simultaneously solve the two problems of preventing corrosion and reducing electromagnetic noise, Patent Document 1 discloses a technique in which a conductive connecting member is interposed between a heat exchanger and a housing. The connecting member has a first connecting part made of the same metal as that used in the heat exchanger and in direct contact with the heat exchanger, and a second connecting part made of the same metal as that used in the housing and in direct contact with the housing. In addition, an insulating layer is provided between the first connecting part and the second connecting part to electrically insulate the first connecting part from the second connecting part.

[0006] In the technology disclosed in Patent Document 1, part of the insulating layer is removed to bring the first connection part and the second connection part, which are dissimilar metals, into partial direct contact, thereby ensuring electrical conduction and reducing electromagnetic noise, while the contact points between the first connection part and the second connection part are covered with a covering member such as waterproof tape to prevent moisture from penetrating the contact points and prevent metal corrosion. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6583489 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the technique disclosed in Patent Document 1 has problems such as an increase in the number of manufacturing steps and components because the structure becomes complicated due to the use of multiple types of metals in the connection members and the provision of an insulating layer.

[0009] The present disclosure has been made in consideration of the above, and has an object to provide an outdoor unit for an air conditioner that has a simple structure and can achieve both prevention of corrosion and reduction of electromagnetic noise. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, the outdoor unit of an air conditioner according to the present disclosure includes a box-shaped housing made of a first metal, a heat exchanger at least a part of which is made of a second metal having a different natural potential from the first metal, disposed within the housing and fixed to the housing via a non-conductive member, and a capacitance-connecting sheet metal which is made of the first metal or a third metal which does not cause galvanic corrosion with the first metal and disposed within the housing. The capacitance-connecting sheet metal is fixed to the housing and electrically connected to the housing, and is disposed with a gap between it and the heat exchanger and electrically connected to the heat exchanger via a capacitance generated between the heat exchanger and the capacitance-connecting sheet metal. Effect of the Invention

[0011] The outdoor unit of an air conditioner according to the present disclosure has a simple structure and provides the effect of being able to prevent corrosion and reduce electromagnetic noise at the same time. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an exploded perspective view showing a schematic diagram of an outdoor unit of an air conditioner according to a first embodiment; [Diagram 2] FIG. 1 is a front view showing an outdoor unit of an air conditioner according to a first embodiment, with a front panel of the housing removed; [Diagram 3] FIG. 1 is a perspective view showing a capacity connection metal plate, a housing floor panel, and a heat exchanger in an outdoor unit of an air conditioner according to a first embodiment; [Figure 4] FIG. 1 is a plan view showing a capacity connection metal plate, a housing floor panel, and a heat exchanger in an outdoor unit of an air conditioner according to a first embodiment. [Diagram 5] FIG. 1 is a schematic diagram showing, as an electric circuit, a transmission path of electromagnetic noise that occurs when a capacitance connection metal plate is not provided in an outdoor unit of an air conditioner according to a first embodiment. [Figure 6] FIG. 1 is an equivalent circuit diagram of a path through which a current that becomes electromagnetic noise is transmitted when a capacitance connection metal plate is not provided in an outdoor unit of an air conditioner according to a first embodiment. [Figure 7]FIG. 1 is a rear view of an outdoor unit of an air conditioner according to a first embodiment, showing a location where electromagnetic noise occurs; [Figure 8] FIG. 1 is an equivalent circuit diagram of a path through which a current that becomes electromagnetic noise is transmitted when a heat exchanger and a housing are in direct contact with each other without an insulating member in an outdoor unit of an air conditioner according to a first embodiment. [Figure 9] FIG. 1 is a plan view showing a capacitance-connecting metal plate, a housing floor panel, and a heat exchanger in the first embodiment, and is a schematic diagram showing a parasitic capacitance generated between the heat exchanger and the capacitance-connecting metal plate. [Figure 10] FIG. 1 is a schematic diagram showing, as an electric circuit, a transmission path of electromagnetic noise that occurs when a capacitance connection metal plate is provided in an outdoor unit of an air conditioner according to a first embodiment. [Figure 11] FIG. 1 is an equivalent circuit diagram of a path through which a current that causes electromagnetic noise is transmitted when a capacitance connection metal plate is provided in an outdoor unit of an air conditioner according to a first embodiment. [Figure 12] FIG. 11 is a perspective view showing a capacity connection metal plate, a housing floor panel, a heat exchanger, and an insulating member when a part of the capacity connection metal plate is hollowed out in an outdoor unit of an air conditioner according to a first modified example of the first embodiment; [Figure 13] FIG. 11 is a perspective view showing a capacity connection metal plate, a contact metal plate, a housing bottom panel, a housing top panel, a heat exchanger, and an insulating member in an outdoor unit of an air conditioner according to a second modification of the first embodiment. [Figure 14] FIG. 11 is a side view showing a contact metal plate, a housing top panel, a covering member, and a heat exchanger in an outdoor unit of an air conditioner according to a second modification of the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An outdoor unit of an air conditioner according to an embodiment will be described below in detail with reference to the drawings.

[0014] Embodiment 1 Fig. 1 is an exploded perspective view showing a schematic diagram of an outdoor unit 1 of an air conditioner according to a first embodiment. As shown in Fig. 1, the outdoor unit 1 of the air conditioner includes a housing 2, a capacity connection metal plate 3, a partition plate 4, a blower 5, a heat exchanger 6, two insulating members 7, a compressor 8, and an electronic circuit board box 9. Hereinafter, the outdoor unit 1 of the air conditioner may also be simply referred to as the outdoor unit 1.

[0015] Hereinafter, when describing the directions of each component of the outdoor unit 1, the depth direction of the outdoor unit 1 is defined as the X-axis direction, the height direction of the outdoor unit 1 is defined as the Y-axis direction, and the width direction of the outdoor unit 1 is defined as the Z-axis direction. The + direction in the X-axis direction is defined as the front, and the - direction in the X-axis direction is defined as the rear. The + direction in the X-axis direction is the direction from the - side to the + side of the X-axis, and the - direction in the X-axis direction is the direction from the + side to the - side of the X-axis. The + direction in the Y-axis direction is defined as the upward direction, and the - direction in the Y-axis direction is defined as the downward direction. The + direction in the Y-axis direction is the direction from the - side to the + side of the Y-axis, and the - direction in the Y-axis direction is the direction from the + side to the - side of the Y-axis. The + direction in the Z-axis direction is defined as the rightward direction, and the - direction in the Z-axis direction is defined as the leftward direction. The + direction in the Z-axis direction is the direction from the - side to the + side of the Z-axis, and the - direction in the Z-axis direction is the direction from the + side to the - side of the Z-axis. In this embodiment, the positive direction of the X-axis along which the airflow generated by the blower 5 of the outdoor unit 1 is discharged to the outside is defined as the front, and the side opposite the front is defined as the back.

[0016] FIG. 2 is a front view showing the outdoor unit 1 of the air conditioner according to the first embodiment, with the housing front panel 2e of the housing 2 removed. In FIG. 2, the heat exchanger 6 is hatched with dots for ease of understanding. As shown in FIGS. 1 and 2, the housing 2 is a box-shaped member that serves as the outer shell of the outdoor unit 1. The housing 2 is made of a first metal. The first metal is preferably a metal with high strength. The first metal is, for example, iron or an iron alloy.

[0017] As shown in FIG. 1, the housing 2 has a housing floor panel 2a, a housing top panel 2b, a first connecting panel 2c, and a second connecting panel 2d. The housing floor panel 2a forms the bottom surface of the outer shell of the outdoor unit 1. The shape of the housing floor panel 2a in a plan view is a rectangle with rounded corners. The housing top panel 2b is disposed above the housing floor panel 2a and spaced apart from the housing floor panel 2a. The housing top panel 2b forms the ceiling surface of the outer shell of the outdoor unit 1. The shape of the housing top panel 2b in a plan view is the same as the shape of the housing floor panel 2a in a plan view.

[0018] The first connecting panel 2c and the second connecting panel 2d connect the housing floor panel 2a and the housing top panel 2b. The first connecting panel 2c has an L-shaped shape in a plan view. The first connecting panel 2c has a housing front panel 2e extending along the Z-axis direction and a housing side panel 2f extending rearward from a left edge portion, which is one edge portion of the housing front panel 2e along the Z-axis direction.

[0019] The housing front panel 2e connects the front edge of the housing floor panel 2a and the front edge of the housing top panel 2b. The housing front panel 2e constitutes the front surface of the outer shell of the outdoor unit 1. An exhaust port 2j is formed in the housing front panel 2e. The exhaust port 2j is an opening for discharging the airflow generated by the blower 5 to the outside of a fan chamber 10 described later. The housing side panel 2f connects the left edge of the housing floor panel 2a and the left edge of the housing top panel 2b. The housing side panel 2f constitutes the left side surface of the outer shell of the outdoor unit 1. The housing front panel 2e and the housing side panel 2f are integrally formed in this embodiment, but may be formed separately.

[0020] The second connecting panel 2d has an L-shaped planar shape. The second connecting panel 2d has a housing side panel 2g extending along the X-axis direction, and a housing back panel 2h extending leftward from a rear edge portion that is one edge portion along the X-axis direction of the housing side panel 2g.

[0021] The housing side panel 2g connects the right edge of the housing floor panel 2a to the right edge of the housing top panel 2b. The housing side panel 2g constitutes the right side of the outer shell of the outdoor unit 1. The housing rear panel 2h connects a part of the rear edge of the housing floor panel 2a to a part of the rear edge of the housing top panel 2b. The housing rear panel 2h constitutes a part of the rear of the outer shell of the outdoor unit 1. The housing side panel 2g and the housing rear panel 2h are formed integrally in this embodiment, but may be formed separately.

[0022] 1 is assembled, the left edge of the housing rear panel 2h and the rear edge of the housing side panel 2f are separated from each other. An air intake port 2i for letting in outside air is formed between the left edge of the housing rear panel 2h and the rear edge of the housing side panel 2f. The air intake port 2i is an opening for letting air outside the housing 2 into a fan chamber 10, which will be described later. The air intake port 2i is surrounded by the housing floor panel 2a, the housing top panel 2b, the housing rear panel 2h, and the housing side panel 2f.

[0023] The capacitance connection sheet metal 3 is a metal member disposed near the heat exchanger 6 in the housing 2. The capacitance connection sheet metal 3 contacts the housing 2 and is fixed to the housing 2 to be electrically connected to the housing 2. The capacitance connection sheet metal 3 does not contact the heat exchanger 6. The capacitance connection sheet metal 3 is disposed with a gap between it and the heat exchanger 6 and is electrically connected to the heat exchanger 6 via the capacitance generated between the heat exchanger 6 and the capacitance connection sheet metal 3. In other words, the capacitance connection sheet metal 3 is electrically connected to the heat exchanger 6 at high frequencies by the capacitance generated between the heat exchanger 6 and the capacitance connection sheet metal 3. In this specification, the phrase "electrically connected at high frequencies" between metal members refers to a state in which the metal members do not contact each other, but the impedance through the gap formed between the metal members is small and the conductivity between the metal members is high.

[0024] As shown in FIG. 2, the capacitance-connecting metal plate 3 is in contact with and fixed to only the housing bottom panel 2a in this embodiment, but may be in contact with and fixed to at least one of the housing bottom panel 2a, the housing top panel 2b, the housing front panel 2e, the housing rear panel 2h, and the housing side panels 2f and 2g. The capacitance-connecting metal plate 3 is made of the same first metal as the housing 2 or a third metal that does not cause galvanic corrosion with the housing 2. For example, when the first metal is either iron or an iron alloy, the third metal is the other of iron and an iron alloy. The first metal and the third metal may be metals having the same natural potential, or may be metals having a small difference in natural potential to the extent that the first metal and the third metal do not cause galvanic corrosion.

[0025] The contact points between the housing 2 and the capacitance-connecting metal plate 3 are joined by welding, screws, etc. If the surface of each panel of the housing 2 is painted or the like and the electrical resistance of the surface of each panel is high, the electrical resistance of the surface of each panel can be reduced by, for example, masking part or all of the joints in advance or removing the paint when fastening the screws using serrated screws.

[0026] As shown in Fig. 2, the partition plate 4 is a metal member that divides the inside of the housing 2 into a fan chamber 10 and an electric chamber 11. The fan chamber 10 and the electric chamber 11 are formed side by side in the Z-axis direction. The partition plate 4 extends in the Y-axis direction from the housing floor panel 2a to the electronic circuit board box 9. The partition plate 4 extends in the X-axis direction from the housing front panel 2e to the housing rear panel 2h shown in Fig. 1.

[0027] As shown in FIG. 2, the blower 5 is a device disposed in the fan chamber 10 to generate an air flow. The blower 5 has a support 5a rising from the housing floor panel 2a, a fan motor 5b attached to the support 5a, and a propeller fan 5c attached to the rotating shaft of the fan motor 5b and rotating with the rotation of the fan motor 5b. The upper end of the support 5a is fixed to the housing top panel 2b. The lower end of the support 5a is fixed to the housing floor panel 2a. The fan motor 5b is electrically connected to an electronic board 9a described later via a fan drive wire 12. The fan motor 5b rotates when it receives a drive signal output from the electronic board 9a via the fan drive wire 12. When the fan motor 5b rotates and the propeller fan 5c is driven, the fan chamber 10 becomes negative pressure, and the air outside the outdoor unit 1 flows into the fan chamber 10 from the air intake port 2i. The air that has flowed into the fan chamber 10 passes through the heat exchanger 6, is turned into an air flow by the blower 5, and is discharged to the outside of the fan chamber 10 through the exhaust port 2j shown in FIG.

[0028] The heat exchanger 6 is disposed in the fan chamber 10 and is a member for exchanging heat between the refrigerant and the outdoor air. Outdoor air to be taken in by the blower 5 passes through the heat exchanger 6. The heat exchanger 6 is, for example, a parallel flow type heat exchanger. The heat exchanger 6 is disposed in the housing 2 and fixed to the housing 2 via an insulating member 7 which is a non-conductive member. At least a part of the heat exchanger 6 is formed of a second metal having a natural potential different from that of the first metal. The second metal is preferably a metal having a high thermal conductivity. The second metal is, for example, aluminum or an aluminum alloy. Although not shown, the heat exchanger 6 has a plurality of fins and a refrigerant conduit. A refrigerant flows through the refrigerant conduit.

[0029] As shown in Fig. 1, the shape of the heat exchanger 6 in a plan view is L-shaped. The heat exchanger 6 extends along the Z-axis direction and then extends forward along the X-axis direction. The portion of the heat exchanger 6 along the Z-axis direction is disposed rearward of the blower 5. The portion of the heat exchanger 6 along the X-axis direction is disposed to the left of the blower 5 when viewed from the front. The heat exchanger 6 and the blower 5 are disposed at a distance from each other and are electrically insulated from each other, or are disposed via an insulating member (not shown) and are electrically insulated from each other.

[0030] The heat exchanger 6 has a flat heat exchanger side end 6a extending in the Y-axis direction. The heat exchanger side end 6a constitutes the front end of the part of the heat exchanger 6 along the X-axis direction. The shape of the heat exchanger side end 6a is rectangular. The heat exchanger side end 6a is a plane perpendicular to the X-axis direction. The heat exchanger 6 also has a pair of heat exchanger side portions 6b, 6c. The heat exchanger side portions 6b, 6c extend from both ends of the heat exchanger side end 6a along the Z-axis direction in a direction away from the sheet metal facing wall 3a described later. The shape of the heat exchanger side portions 6b, 6c is rectangular. In this embodiment, the Z-axis direction is perpendicular to the up-down direction.

[0031] The heat exchanger 6 and the first connecting panel 2c and the second connecting panel 2d are arranged at intervals from each other and are electrically insulated from each other, or are arranged via an insulating member (not shown) and are electrically insulated from each other. As shown in FIG. 2, the upper end of the heat exchanger 6 is fixed to the housing top panel 2b via an insulating member 7. The lower end of the heat exchanger 6 is fixed to the housing bottom panel 2a via an insulating member 7. The heat exchanger 6 is electrically insulated from the housing top panel 2b and the housing bottom panel 2a. The heat exchanger 6 is arranged without being electrically connected to the housing 2, the blower 5, and other metal members arranged around the heat exchanger 6. However, as described above, the heat exchanger 6 is electrically connected to the capacitance-connecting metal plate 3 at high frequencies due to the electrostatic capacitance generated between the heat exchanger 6 and the capacitance-connecting metal plate 3.

[0032] The two insulating members 7 shown in FIG. 1 are made of an electrically insulating material such as resin. Hereinafter, when the two insulating members 7 are to be distinguished from each other, the insulating member 7 provided at the lower end of the heat exchanger 6 is referred to as the first insulating member 7a, and the insulating member 7 provided at the upper end of the heat exchanger 6 is referred to as the second insulating member 7b. In this embodiment, the first insulating member 7a and the second insulating member 7b, which have the same planar shape and size as the heat exchanger 6, are used to cover the entire bottom and top surfaces of the heat exchanger 6, thereby electrically insulating the heat exchanger 6 from the housing 2, but this is not intended to limit the electrical insulation means between the two members. For example, a configuration may be adopted in which a platform made of an electrically insulating material is provided at several places on the bottom surface of the heat exchanger 6, and the platform is interposed between the heat exchanger 6 and the housing floor panel 2a. With this configuration, the heat exchanger 6 and the housing floor panel 2a are spaced apart from each other in the Y-axis direction, so that the heat exchanger 6 and the housing floor panel 2a can be electrically insulated from each other.

[0033] 2, the compressor 8 is disposed in the electric compartment 11 and is a device that compresses the refrigerant flowing in the heat exchanger 6. The compressor 8 is disposed on the housing floor panel 2a in the lower space of the electric compartment 11. The compressor 8 is fixed to the housing floor panel 2a with screws or the like.

[0034] The electronic board box 9 is a member that houses electronic boards 9a such as control boards required to operate the outdoor unit 1. The electronic board box 9 is formed in a hollow rectangular parallelepiped shape. The electronic board box 9 is fixed to the upper end of the partition plate 4, and is disposed across the fan chamber 10 and the electric chamber 11. A heat sink 9b extending downward is attached to the portion of the electronic board box 9 that is disposed in the fan chamber 10. The heat sink 9b is exposed to the fan chamber 10. The heat sink 9b is cooled by the air flow generated by the blower 5.

[0035] The portion of the electronic board box 9 that is arranged in the electric chamber 11 is disposed above the compressor 8. A compressor drive wire 13 is connected to the portion of the electronic board 9a that is arranged in the electric chamber 11. The compressor 8 is electrically connected to the electronic board 9a via the compressor drive wire 13. The compressor 8 drives when it receives a drive signal output from the electronic board 9a via the compressor drive wire 13.

[0036] The electrical compartment 11 is surrounded by the housing floor panel 2a, the partition plate 4, the housing side panel 2g, the electronic circuit board box 9, and the housing front panel 2e and housing rear panel 2h shown in Fig. 1, and has a waterproof structure that prevents the intrusion of moisture such as rainwater from outside the housing 2. A stop valve 17 is provided at the bottom of the outer surface of the housing side panel 2g. The stop valve 17 serves as a terminal for connecting a refrigerant piping that is connected to an indoor unit (not shown).

[0037] The compressor 8 and the stop valve 17 are connected to each other via a plurality of refrigerant pipes 18. The compressor 8 and the heat exchanger 6 are connected to each other via a plurality of refrigerant pipes 18. A connection 19 between the heat exchanger 6 and the refrigerant pipes 18 is disposed in the electrical chamber 11 having a waterproof structure. By disposing the connection 19 in the electrical chamber 11 in this manner, it is possible to prevent the connection 19 from coming into contact with moisture, and therefore it is possible to prevent the connection 19 from corroding. In addition, in order to further enhance the waterproof effect of the connection 19, the connection 19 may be waterproofed by wrapping a waterproof tape or the like around it. Although not specifically illustrated, the refrigerant pipes 18 are connected to valve devices such as a four-way valve that switches the direction of the refrigerant flow and an expansion valve that expands the refrigerant to a predetermined pressure. The connection form of the refrigerant pipes 18 is not limited to the example illustrated.

[0038] An interface panel 20 is installed in the upper space of the electrical room 11. The interface panel 20 is fixed to the inner surface of the housing side panel 2g and the lower surface of the electronic board box 9. A terminal block 21 is installed on the interface panel 20. An external AC power line 14 and an internal power line 15 are connected to the terminal block 21. The external AC power line 14 is electrically connected to the internal power line 15 via the terminal block 21. The internal power line 15 is electrically connected to the electronic board 9a. Power to the electronic board 9a is supplied via the external AC power line 14, the terminal block 21, and the internal power line 15. The voltage of the power supplied to the electronic board 9a is, for example, single-phase 200V, but is not limited to this voltage.

[0039] The interface panel 20 is formed of the same first metal as the housing side panel 2g. Therefore, the interface panel 20 is joined to the housing side panel 2g in a state where the electrical resistance is low. The interface panel 20 is connected to the signal ground of the electronic board 9a. The interface panel 20 has an earth connection point 20a to which the earth wire 16 is connected. The interface panel 20 is grounded via the earth connection point 20a and the earth wire 16. The housing 2 joined to the interface panel 20 and the partition plate 4 joined to the housing 2 are grounded via the earth connection point 20a and the earth wire 16. The heat exchanger 6 is electrically connected to the earth connection point 20a via the connection part 19 with the refrigerant pipe 18, the compressor 8, etc., but is not directly short-circuited with the housing 2 and the partition plate 4.

[0040] An opening 2k that communicates the inside and outside of the housing 2 is formed in the housing side panel 2g. The interface panel 20 and the terminal block 21 installed in the electric room 11 are visible and accessible through the opening 2k. Wiring of various power lines can be performed through the opening 2k. An interface cover (not shown) is detachably attached to the housing side panel 2g, and the opening 2k is covered with the interface cover.

[0041] Next, the configuration of the capacity connection metal plate 3 will be further described with reference to Fig. 3 and Fig. 4. Fig. 3 is a perspective view showing the capacity connection metal plate 3, the housing floor panel 2a, and the heat exchanger 6 in the outdoor unit 1 of the air conditioner according to the first embodiment. Fig. 4 is a plan view showing the capacity connection metal plate 3, the housing floor panel 2a, and the heat exchanger 6 in the outdoor unit 1 of the air conditioner according to the first embodiment.

[0042] The location of the capacity-connecting metal plate 3 is not particularly limited as long as it is near the heat exchanger 6, but in this embodiment, it is near the heat exchanger side end 6a of the heat exchanger 6. The capacity-connecting metal plate 3 has a metal plate facing wall 3a, a pair of metal plate side walls 3b, 3c, and a plurality of metal plate fixing parts 3d. The metal plate facing wall 3a, the metal plate side walls 3b, 3c, and the metal plate fixing parts 3d are all flat parts. The metal plate facing wall 3a is rectangular in shape. The metal plate facing wall 3a is disposed in front of the heat exchanger side end 6a with a gap between it and the heat exchanger side end 6a. The metal plate facing wall 3a faces the heat exchanger side end 6a.

[0043] The sheet metal side walls 3b and 3c are shaped like a rectangle. One sheet metal side wall 3b extends from one end of the sheet metal facing wall 3a along the Z-axis direction toward the heat exchanger side portion 6b, and is disposed with a gap between the sheet metal side wall 3b and the heat exchanger side portion 6b. The other sheet metal side wall 3c extends from the other end of the sheet metal facing wall 3a along the Z-axis direction toward the heat exchanger side portion 6c, and is disposed with a gap between the sheet metal side wall 3b and the heat exchanger side portion 6c. The sheet metal side wall 3b faces the heat exchanger side portion 6b. The sheet metal side wall 3c faces the heat exchanger side portion 6c. The sheet metal side walls 3b and 3c are bent at right angles from the end of the sheet metal facing wall 3a along the Z-axis direction toward the rear.

[0044] The sheet metal fixing portion 3d is a portion fixed to the housing 2. The shape of the sheet metal fixing portion 3d is rectangular. One sheet metal fixing portion 3d is provided at each of the lower end of the sheet metal facing wall 3a and the lower end of the pair of sheet metal side walls 3b, 3c. The sheet metal fixing portion 3d provided at the lower end of the sheet metal facing wall 3a extends in a direction away from the heat exchanger side end 6a. The sheet metal fixing portion 3d provided at the lower end of the sheet metal side wall 3b extends in a direction away from the heat exchanger side portion 6b. The sheet metal fixing portion 3d provided at the lower end of the sheet metal side wall 3c extends in a direction away from the heat exchanger side portion 6c.

[0045] In this embodiment, the sheet metal fixing part 3d is in contact with and fixed to only the housing floor panel 2a, but it may be in contact with and fixed to at least one of the housing floor panel 2a, the housing top panel 2b, the housing front panel 2e, the housing rear panel 2h, and the housing side panels 2f and 2g shown in FIG. 1. The sheet metal fixing part 3d is electrically connected to the housing floor panel 2a. The contact points between the sheet metal fixing part 3d and the housing 2 are joined by welding, screws, or the like. If the surfaces of the panels of the housing 2 are painted or the like and the electrical resistance of the surfaces of the panels is high, the electrical resistance of the surfaces of the panels may be reduced, for example, by masking a part or all of the joints in advance or by removing the paint when tightening the screws using serrated screws.

[0046] The gap formed between the heat exchanger side end 6a and the sheet metal facing wall 3a and the gap formed between the heat exchanger side parts 6b, 6c and the sheet metal side walls 3b, 3c are mutually connected. As shown in FIG. 4, in the present embodiment, a dielectric 3e is inserted into the gap formed between the heat exchanger 6 and the capacity-connecting sheet metal 3, but the dielectric 3e does not have to be inserted. In FIG. 4, the dielectric 3e is hatched to clarify the position of the dielectric 3e. The dielectric 3e plays a role in adjusting the magnitude of the electrostatic capacitance generated between the heat exchanger 6 and the capacity-connecting sheet metal 3.

[0047] The pair of sheet metal side walls 3b, 3c may not be provided, or one of the pair of sheet metal side walls 3b, 3c may be omitted. Although the capacity-connection sheet metal 3 is disposed with a gap between it and the heat exchanger side end portion 6a and the heat exchanger side portion 6b, it may be disposed with a gap between it and any surface of the heat exchanger 6.

[0048] Next, the operation and effects of the outdoor unit 1 according to the first embodiment will be described.

[0049] As shown in FIG. 2, when power is supplied to the electronic board 9a from the external AC power line 14 via the internal power line 15, the electronic board 9a goes into a standby state. When the electronic board 9a receives a command signal to start operation from the indoor unit via a communication signal line between the indoor unit and the outdoor unit 1 (not shown), the electronic board 9a starts operation of the outdoor unit 1. Specifically, the electronic board 9a outputs a drive signal to the fan motor 5b via the fan drive wire 12 to drive the fan motor 5b. In addition, the electronic board 9a outputs another drive signal to the compressor 8 via the compressor drive wire 13 to drive the compressor 8. At this time, a square wave pulse generated by switching of a power semiconductor is generally used as the drive signal output by the electronic board 9a. Therefore, the drive signal contains high-frequency components that are not originally necessary to drive the AC motor of the compressor 8 and the fan motor 5b, such as switching noise of the power semiconductor and harmonic components of the square wave pulse. Such high-frequency components become a source of electromagnetic noise, and are one of the factors that cause electromagnetic noise to be emitted to the outside of the housing 2 through a transmission path described later.

[0050] FIG. 5 is a schematic diagram showing, as an electric circuit, a transmission path of electromagnetic noise generated when the outdoor unit 1 of the air conditioner according to the first embodiment does not include the capacitance connection plate 3. In FIG. 5, the heat exchanger 6 is hatched with dots for easy understanding. For example, when a three-phase motor is used as the AC motor of the compressor 8, the electromagnetic noise generated in the electronic board 9a is transmitted to the housing of the compressor 8 via the three-phase motor winding neutral point 8d and the parasitic capacitance 8b existing between the motor winding 8a and the housing of the compressor 8. A part of the electromagnetic noise transmitted to the housing of the compressor 8 is transmitted to the housing floor panel 2a and then returned to the electronic board 9a. However, since there is an impedance component such as a contact resistance 8c between the housing of the compressor 8 and the housing floor panel 2a, a part of the electromagnetic noise transmitted to the housing of the compressor 8 is transmitted to the heat exchanger 6 through the refrigerant piping 18.

[0051] The characteristics of the parasitic impedance components of the heat exchanger 6 vary depending on the structure of the heat exchanger 6. As an example, the heat exchanger 6 is assumed to be a parallel-flow type heat exchanger equipped with corrugated fins and flat refrigerant conduits, and an equivalent circuit in which the parasitic inductances 23 of the heat exchanger 6 are combined as shown in FIG. 5 is shown. The parasitic impedance components such as the parasitic inductances 23 of the heat exchanger 6 exist in a complex manner as a distributed constant circuit as shown in FIG. 5. Since the heat exchanger 6 and the housing 2 are electrically insulated by the first insulating member 7a and the second insulating member 7b, parasitic capacitances 22a and 22b are generated between the heat exchanger 6 and the housing 2. That is, the parasitic capacitance 22a is generated between the heat exchanger 6 and the housing bottom panel 2a, and the parasitic capacitance 22b is generated between the heat exchanger 6 and the housing top panel 2b. The parasitic capacitances 22a and 22b are generated on the transmission path of the electromagnetic noise.

[0052] Fig. 6 is an equivalent circuit diagram of a path through which a current that becomes electromagnetic noise is transmitted in the outdoor unit 1 of the air conditioner according to the first embodiment when the capacitance connection metal plate 3 is not provided. The electromagnetic noise transmitted from the electronic board 9a through the compressor 8 to the heat exchanger 6 and the housing 2 shown in Fig. 5 generates resonance with the parasitic inductance 23 of the heat exchanger 6, generates resonance with the parasitic capacitances 22a and 22b, and further generates resonance with parasitic impedance components such as the parasitic inductance 24 of each panel of the housing 2. At this time, a change in voltage occurs in the parasitic capacitances 22a and 22b due to the resonance.

[0053] FIG. 7 is a rear view of the outdoor unit 1 of the air conditioner according to the first embodiment, showing the locations where electromagnetic noise occurs. In FIG. 7, the heat exchanger 6 is hatched with dots for ease of understanding. Between the heat exchanger 6 and each panel of the housing 2, gaps G1, G2, G3, and G4 are formed to ensure electrical insulation. In FIG. 7, the positions of the gaps G1, G2, G3, and G4 are surrounded by dashed lines. In FIG. 7, the gaps G1, G2, G3, and G4 are shown as not being present in a portion between the heat exchanger 6 and the housing 2, but in reality, there are elongated gaps G1, G2, G3, and G4 that extend to surround the four sides of the heat exchanger 6. The gaps G1, G2, G3, and G4 are locations where electromagnetic noise occurs. Between the heat exchanger 6 and the housing floor panel 2a and between the heat exchanger 6 and the housing top panel 2b, voltage changes occur through the parasitic capacitances 22a and 22b shown in FIG. 5. As a result, the gaps G1, G2, G3, and G4 function as slot antennas, and generate further electromagnetic noise in response to changes in the voltage applied to both ends of the gaps G1, G2, G3, and G4. The electromagnetic noise generated in the gaps G1, G2, G3, and G4 is radiated to the outside of the housing 2 through the air intake 2i.

[0054] FIG. 8 is an equivalent circuit diagram of a path of a current that becomes electromagnetic noise when the heat exchanger 6 and the housing 2 are in direct contact without the insulating member 7 in the outdoor unit 1 of the air conditioner according to the first embodiment. By removing the first insulating member 7a and the second insulating member 7b shown in FIG. 7, the heat exchanger 6 and each panel of the housing 2 are electrically connected. That is, the heat exchanger 6 and each panel of the housing 2 are electrically short-circuited. Therefore, as shown in FIG. 8, the parasitic capacitances 22a and 22b generated between the heat exchanger 6 and each panel of the housing 2 are short-circuited. As a result, no change in voltage occurs between the heat exchanger 6 and the housing floor panel 2a and between the heat exchanger 6 and the housing top panel 2b shown in FIG. 7 through the parasitic capacitances 22a and 22b shown in FIG. 8, and no electromagnetic noise occurs in the gaps G1, G2, G3, and G4.

[0055] 7 is made of dissimilar metals, if an insulating member 7 is not provided between the heat exchanger 6 and the housing 2, it is possible to prevent electromagnetic noise from occurring in the gaps G1, G2, G3, and G4 and reduce the radiation of electromagnetic noise to the outside of the housing 2, but corrosion occurs in the heat exchanger 6, which has a low natural potential, at the contact points between the heat exchanger 6 and the housing 2. On the other hand, if an insulating member 7 is provided between the heat exchanger 6 and the housing 2, it is possible to prevent corrosion in the heat exchanger 6, which has a low natural potential, at the contact points between the heat exchanger 6 and the housing 2, but electromagnetic noise occurs in the gaps G1, G2, G3, and G4, increasing the amount of electromagnetic noise radiation to the outside of the housing 2.

[0056] FIG. 9 is a plan view showing the capacitance connection metal plate 3, the housing floor panel 2a, and the heat exchanger 6 in the first embodiment, and is a diagram showing a parasitic capacitance 22c generated between the heat exchanger 6 and the capacitance connection metal plate 3. FIG. 10 is a schematic diagram showing, as an electric circuit, a transmission path of electromagnetic noise generated when the capacitance connection metal plate 3 is provided in the outdoor unit 1 of the air conditioner according to the first embodiment. FIG. 11 is a circuit diagram showing, as an equivalent circuit, a path of a current that becomes electromagnetic noise when the capacitance connection metal plate 3 is provided in the outdoor unit 1 of the air conditioner according to the first embodiment. As shown in FIGS. 9 and 10, the outdoor unit 1 includes a box-shaped housing 2 formed of a first metal, a heat exchanger 6 formed of a second metal having a natural potential different from that of the first metal, disposed in the housing 2, and fixed to the housing 2 via an insulating member 7, and a capacitance connection metal plate 3 formed of the first metal or a third metal that does not corrode the first metal, and disposed in the housing 2. The capacitance-connecting metal plate 3 shown in Fig. 9 is fixed to the housing 2 and electrically connected to the housing 2, and is disposed with a gap between it and the heat exchanger 6. As a result, a parasitic capacitance 22c is generated between the heat exchanger 6 and the capacitance-connecting metal plate 3. The distance between the heat exchanger 6 and the capacitance-connecting metal plate 3 is smaller than the distance between the heat exchanger 6 and each panel of the housing 2, and the area where the heat exchanger 6 faces the capacitance-connecting metal plate 3 is relatively large, so that the parasitic capacitance 22c has a larger capacitance than the parasitic capacitances 22a and 22b. The parasitic capacitance 22c has a capacitance of, for example, several thousand pF to several tens of thousands pF. The magnitude of the capacitance generated between the capacity connection metal plate 3 and the heat exchanger 6 is determined by the distance between the capacity connection metal plate 3 and the heat exchanger 6, the area where the capacity connection metal plate 3 and the heat exchanger 6 face each other, and, if a dielectric 3e is inserted into the gap between the capacity connection metal plate 3 and the heat exchanger 6, the magnetic permeability of the dielectric 3e.

[0057] The heat exchanger 6 and each panel of the housing 2 shown in FIG. 10 are electrically connected through the parasitic capacitances 22a and 22b, as well as the parasitic capacitance 22c having a larger capacitance than the parasitic capacitances 22a and 22b. That is, the conductivity between the heat exchanger 6 and each panel of the housing 2 is increased in a high-frequency signal such as electromagnetic noise. This suppresses the change in voltage generated through the parasitic capacitances 22a and 22b between the heat exchanger 6 and the housing 2, and suppresses the electromagnetic noise emitted from the gaps G1, G2, G3, and G4 shown in FIG. 7. In addition, the radiation amount of electromagnetic noise of about 30 MHz to 300 MHz generated from the housing 2 can be reduced by the parasitic capacitance 22c. On the other hand, as shown in FIG. 9 and FIG. 10, the heat exchanger 6 does not contact the housing 2 and the capacitance connection plate metal 3, so that corrosion due to contact between the heat exchanger 6 and the housing 2 and the capacitance connection plate metal 3 can be prevented. In addition, in this embodiment, since the capacitance-connecting metal plate 3 is made of the same first metal as the housing 2 or a third metal that does not corrode the first metal, it is possible to prevent corrosion caused by contact between the housing 2 and the capacitance-connecting metal plate 3. In other words, with a simple structure that includes the capacitance-connecting metal plate 3, it is possible to prevent corrosion and reduce electromagnetic noise at the same time.

[0058] In this embodiment, as shown in Fig. 2, the capacitance connection metal plate 3 is fixed and electrically connected only to the housing floor panel 2a, but it may be fixed to all of the housing floor panel 2a, the housing top panel 2b, the housing front panel 2e, the housing rear panel 2h, and the housing side panels 2f and 2g shown in Fig. 1. In this way, the electrical connection between each panel is strengthened, and the contact resistance and parasitic inductance 23 of the housing 2 shown in Fig. 10 can be reduced. Therefore, the electromagnetic noise transmitted between the electronic board 9a, the compressor 8, and each panel of the housing 2, i.e., the noise terminal voltage, the interference power intensity, etc., can be reduced.

[0059] In this embodiment, as shown in Figure 9, a dielectric 3e is inserted into the gap formed between the heat exchanger 6 and the capacity-connection metal plate 3, and by changing the magnetic permeability of the dielectric 3e, the magnitude of the electrostatic capacitance generated between the heat exchanger 6 and the capacity-connection metal plate 3 can be easily adjusted.

[0060] In this embodiment, the first metal is either iron or an iron alloy, and the third metal is either iron or an iron alloy, so that even if the capacitance-connection sheet metal 3 shown in Fig. 9 is made of the third metal, it is possible to prevent corrosion due to contact between the housing 2 made of the first metal and the capacitance-connection sheet metal 3. Also, in this embodiment, the second metal is aluminum or an aluminum alloy, so that it is possible to increase the thermal conductivity of the heat exchanger 6 made of the second metal.

[0061] 9, in this embodiment, the heat exchanger 6 has a flat heat exchanger-side end 6a extending in the vertical direction, and the capacity-connecting metal plate 3 has a metal-plate-facing wall 3a disposed with a gap between the heat exchanger-side end 6a and the capacity-connecting metal plate 3. This makes it possible to generate a parasitic capacitance 22c between the heat exchanger 6 and the capacity-connecting metal plate 3 with a simple structure.

[0062] In this embodiment, as shown in FIG. 9, the heat exchanger 6 has a pair of heat exchanger side portions 6b, 6c extending from both ends of the heat exchanger side end 6a along the Z-axis direction in a direction away from the sheet metal facing wall 3a. On the other hand, the capacity connection sheet metal 3 has a sheet metal side wall 3b extending from one end of the sheet metal facing wall 3a along the Z-axis direction toward the heat exchanger side portion 6b and disposed with a gap from the heat exchanger side portion 6b. In addition, the capacity connection sheet metal 3 has a sheet metal side wall 3c extending from the other end of the sheet metal facing wall 3a along the Z-axis direction toward the heat exchanger side portion 6c and disposed with a gap from the heat exchanger side portion 6c. With these configurations, the area where the heat exchanger 6 and the capacity connection sheet metal 3 face each other can be increased, and the parasitic capacitance 22c generated between the heat exchanger 6 and the capacity connection sheet metal 3 can be increased.

[0063] In this embodiment, as shown in Fig. 9, the gap formed between the heat exchanger side end 6a and the sheet metal facing wall 3a and the gap formed between the heat exchanger side portion 6b and the sheet metal side wall 3b are mutually connected. Also, the gap formed between the heat exchanger side end 6a and the sheet metal facing wall 3a and the gap formed between the heat exchanger side portion 6c and the sheet metal side wall 3c are mutually connected. This makes it possible to create a space into which a single dielectric 3e is inserted.

[0064] In an aluminum parallel-flow heat exchanger, aluminum is used as the material for the fins and the refrigerant conduit, so if iron is used as the material for the housing 2, corrosion may occur in both the fins and the refrigerant conduit. If corrosion occurs in the refrigerant conduit and a hole is formed, the refrigerant in the refrigerant conduit leaks into the atmosphere. The leakage of the refrigerant into the atmosphere impairs the cooling and heating function of the air conditioner. In this way, in an aluminum parallel-flow heat exchanger, it is important to take measures to prevent corrosion because corrosion is a major problem, and it is also necessary to take measures to reduce electromagnetic noise generated by taking measures to prevent corrosion. Therefore, using the capacity connection sheet metal 3 and the insulating member 7 shown in FIG. 2 as in this embodiment to prevent corrosion and reduce electromagnetic noise at the same time is particularly useful when using a heat exchanger such as an aluminum parallel-flow heat exchanger in which corrosion is a major problem. In other words, using the capacity connection metal plate 3 and insulating member 7 as in this embodiment to prevent corrosion and reduce electromagnetic noise at the same time is particularly useful when using a heat exchanger in which the natural potential of the refrigerant conduit is lower than the natural potential of surrounding members such as the housing 2.

[0065] FIG. 12 is a perspective view showing the capacity connection sheet metal 3, the housing floor panel 2a, the heat exchanger 6, and the insulating member 7 in the outdoor unit 1 of the air conditioner according to the first modified example of the first embodiment, in which a part is cut out. As shown in FIG. 12, the capacity connection sheet metal 3 may have a cutout portion 3f formed by cutting out a part of the capacity connection sheet metal 3. The cutout portion 3f is formed by penetrating a part of the capacity connection sheet metal 3 in the thickness direction of the capacity connection sheet metal 3. By forming such a cutout portion 3f in the capacity connection sheet metal 3, it is possible to prevent a decrease in ventilation caused by the provision of the capacity connection sheet metal 3, and to adjust the magnitude of the electrostatic capacitance generated between the heat exchanger 6 and the capacity connection sheet metal 3. The cutout portion 3f is formed in at least one of the sheet metal facing wall 3a, the sheet metal side wall 3b, and the sheet metal side wall 3c of the capacity connection sheet metal 3. For example, the cutout portion 3f may be formed in either one of the sheet metal facing wall 3a and the sheet metal side walls 3b, 3c, or may be formed in both the sheet metal facing wall 3a and the sheet metal side walls 3b, 3c. In this embodiment, the cutout portion 3f is formed only in the sheet metal facing wall 3a. The shape of the cutout portion 3f is not particularly limited, but is an elongated rectangle in this embodiment. The number of cutout portions 3f is not particularly limited, but is four in this embodiment. The four cutout portions 3f are arranged side by side so as to be parallel to the outer shape of the sheet metal facing wall 3a.

[0066] FIG. 13 is a perspective view showing the capacity connection metal plate 3, the contact metal plate 25, the housing floor panel 2a, the housing top panel 2b, the heat exchanger 6, and the insulating member 7 in the outdoor unit 1 of the air conditioner according to the second modification of the first embodiment. FIG. 14 is a side view showing the contact metal plate 25, the housing top panel 2b, the covering member 26, and the heat exchanger 6 in the outdoor unit 1 of the air conditioner according to the second modification of the first embodiment. In FIG. 13, the insulating member 7 is hatched to clarify the range of the insulating member 7. In FIG. 14, the covering member 26 is hatched to clarify the range of the covering member 26. In the above-mentioned embodiment, the housing 2 and the heat exchanger 6 are in contact with each other via the insulating member 7, which is a non-conductive member. However, as shown in FIG. 13 and FIG. 14, a configuration may be adopted in which a part of the housing 2 and a part of the heat exchanger 6 are in contact with each other via the contact metal plate 25, which is a conductive member, and the contact point between the housing 2 and the heat exchanger 6 is covered with the covering member 26, such as a waterproof tape. This enhances the effect of reducing electromagnetic noise by the capacitance-connecting metal plate 3. In addition, the areas covered with waterproof tape or the like are limited, which makes it possible to suppress problems such as a complicated structure, an increase in manufacturing steps, and an increase in the number of parts that would otherwise be caused by using the waterproof covering member 26.

[0067] The second insulating member 7b shown in FIG. 13 covers a part of the upper end of the heat exchanger 6, but does not cover the entire upper end of the heat exchanger 6. The remaining part of the upper end of the heat exchanger 6 is covered by the contact sheet metal 25. The contact sheet metal 25 is disposed at the upper end of the part of the heat exchanger 6 along the Z-axis direction. As shown in FIG. 14, the contact sheet metal 25 has a contact sheet metal horizontal wall 25a, a pair of contact sheet metal vertical walls 25b, 25c, and a pair of contact sheet metal fixing parts 25d, 25e. The contact sheet metal horizontal wall 25a, the contact sheet metal vertical walls 25b, 25c, and the contact sheet metal fixing parts 25d, 25e are all flat parts. The contact sheet metal horizontal wall 25a has a rectangular shape. The contact sheet metal horizontal wall 25a is disposed at the upper end of the part of the heat exchanger 6 along the Z-axis direction. The contact sheet metal vertical walls 25b and 25c are shaped like a rectangle. One of the contact sheet metal vertical walls 25b extends downward from one end of the contact sheet metal horizontal wall 25a along the X-axis direction, and is disposed at the front end of the heat exchanger 6 along the Z-axis direction. The side of the contact sheet metal vertical wall 25b facing the heat exchanger 6 is in direct contact with the heat exchanger 6. The other contact sheet metal vertical wall 25c extends downward from the other end of the contact sheet metal horizontal wall 25a along the X-axis direction, and is disposed at the rear end of the heat exchanger 6 along the Z-axis direction. The side of the contact sheet metal vertical wall 25c facing the heat exchanger 6 is in direct contact with the heat exchanger 6. The contact sheet metal vertical walls 25b and 25c are bent downward at a right angle from the end of the contact sheet metal horizontal wall 25a along the X-axis direction.

[0068] The contact sheet metal fixing parts 25d and 25e are parts fixed to the housing 2. The contact sheet metal fixing parts 25d and 25e are rectangular in shape. The contact sheet metal fixing part 25d protrudes forward from one end of the contact sheet metal horizontal wall 25a along the X-axis direction beyond the contact sheet metal vertical wall 25b. The contact sheet metal fixing part 25e protrudes rearward from the other end of the contact sheet metal horizontal wall 25a along the X-axis direction beyond the contact sheet metal vertical wall 25c. The contact sheet metal fixing parts 25d and 25e are in contact with and fixed to the housing top panel 2b. The contact sheet metal fixing parts 25d and 25e are joined to the housing top panel 2b by screws or the like. The contact sheet metal 25 is formed of the same first metal as the housing 2 or a third metal that does not cause galvanic corrosion with the housing 2. When moisture adheres to the contact point between the contact metal plate 25 made of the first metal or the third metal and the heat exchanger 6 made of the second metal, corrosion occurs in the heat exchanger 6, which has a low natural potential. In this modification, the side and bottom of the contact metal plate vertical wall 25b facing away from the heat exchanger 6 are covered with a covering member 26. The side and bottom of the contact metal plate vertical wall 25c facing away from the heat exchanger 6 are covered with a covering member 26. That is, the periphery of the contact point between the contact metal plate 25 and the heat exchanger 6 is covered with a covering member 26 such as a waterproof tape. This blocks the intrusion of moisture into the contact point between the contact metal plate 25 and the heat exchanger 6, thereby preventing corrosion of the heat exchanger 6.

[0069] The entire heat exchanger 6 does not need to be made of the second metal, but at least a part of the heat exchanger 6 may be made of the second metal. For example, at least one of the fins and the refrigerant conduit of the heat exchanger 6 may be made of the second metal.

[0070] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies. Parts of the configurations may be omitted or modified without departing from the spirit of the invention. [Explanation of symbols]

[0071] 1 Outdoor unit of air conditioner, 2 Housing, 2a Housing floor panel, 2b Housing top panel, 2c First connecting panel, 2d Second connecting panel, 2e Housing front panel, 2f, 2g Housing side panel, 2h Housing rear panel, 2i Air intake, 2j Exhaust port, 2k Opening, 3 Capacity connection sheet metal, 3a Sheet metal facing wall, 3b, 3c Sheet metal side wall, 3d Sheet metal fixing part, 3e Dielectric, 3f Hole, 4 Partition plate, 5 Blower, 5a Support, 5b Fan motor, 5c Propeller fan, 6 Heat exchanger, 6a Heat exchanger side end, 6b, 6c Heat exchanger side part, 7 Insulating member, 7a First insulating member, 7b Second insulating member, 8 Compressor, 8a Motor winding, 8b, 22a, 22b, 22c parasitic capacitance, 8c contact resistance, 8d three-phase motor winding neutral point, 9 electronic circuit board box, 9a electronic circuit board, 9b heat sink, 10 fan chamber, 11 electrical chamber, 12 fan drive wire, 13 compressor drive wire, 14 external AC power line, 15 internal power line, 16 earth wire, 17 stop valve, 18 refrigerant piping, 19 connection part, 20 interface panel, 20a earth connection point, 21 terminal block, 23, 24 parasitic inductance, 25 contact metal plate, 25a contact metal plate horizontal wall, 25b, 25c contact metal plate vertical wall, 25d, 25e contact metal plate fixing part, 26 covering member.

Claims

1. a box-shaped housing made of a first metal; a heat exchanger at least a portion of which is made of a second metal having a natural potential different from that of the first metal, the heat exchanger being disposed within the housing and fixed to the housing via a non-conductive member; a capacitance-connecting metal plate that is formed from the first metal or a third metal that does not cause galvanic corrosion with the first metal and is disposed within the housing; The capacity connection sheet metal is fixed to the housing and electrically connected to the housing, and is positioned with a gap between it and the heat exchanger and is electrically connected to the heat exchanger via the electrostatic capacitance generated between the heat exchanger and the capacity connection sheet metal.This is an outdoor unit for an air conditioner.

2. the housing has a housing bottom panel, a housing top panel disposed above the housing bottom panel, and a housing front panel, a housing rear panel, and a housing side panel connecting the housing bottom panel and the housing top panel, 2. The outdoor unit of an air conditioner as described in claim 1, wherein the capacitance connection metal plate is fixed to at least one of the housing floor panel, the housing top panel, the housing front panel, the housing rear panel and the housing side panel.

3. 3. The outdoor unit for an air conditioner according to claim 1, wherein a dielectric is inserted into the gap formed between the heat exchanger and the capacitance connection metal plate.

4. the first metal is one of iron and an iron alloy; the third metal is the other of iron and an iron alloy; 3. The outdoor unit of an air conditioner according to claim 1, wherein the second metal is aluminum or an aluminum alloy.

5. The heat exchanger has a planar heat exchanger side end portion extending in a vertical direction, 3. The outdoor unit for an air conditioner according to claim 1, wherein the capacity-connecting metal plate has a metal plate facing wall disposed on the heat exchanger side end with the gap therebetween.

6. The heat exchanger has a pair of heat exchanger side portions extending in a direction away from the sheet metal facing wall from both ends of the heat exchanger side end along a direction perpendicular to the up-down direction, The capacity connection sheet metal has a sheet metal side wall extending from one end or both ends of the sheet metal facing wall along a direction perpendicular to the up-down direction toward the heat exchanger side portion and disposed with a gap between the heat exchanger side portion, The outdoor unit of an air conditioner as described in claim 5, wherein the gap formed between the heat exchanger side end and the sheet metal facing wall and the gap formed between the heat exchanger side portion and the sheet metal side wall are mutually connected.

7. 3. The outdoor unit for an air conditioner according to claim 1, wherein the capacity-connecting metal plate has a cutout portion formed by hollowing out a part of the capacity-connecting metal plate.

8. a portion of the housing and a portion of the heat exchanger are in contact with each other; 3. The outdoor unit for an air conditioner according to claim 1, wherein a contact area between the housing and the heat exchanger is covered with a covering member.

Images