JP7293783B2 - Outdoor unit for air conditioner - Google Patents

Description

TECHNICAL FIELD The present invention relates to an outdoor unit used in an air conditioner and to which a plurality of indoor units are connected.

In an air conditioner in which a plurality of indoor units are connected to an outdoor unit by liquid pipes and gas pipes, the housing of the outdoor unit is connected to a liquid pipe connection portion to which the liquid pipes are connected and the gas pipes. (hereinafter, the liquid pipe connection and the gas pipe connection may be collectively referred to as a connection port).
The connection port is located in the machine room where the compressor, multiple expansion valves, etc. are housed. In this machine room, multiple expansion valves are provided to connect the connection port to the compressor, outdoor heat exchanger, etc. It is demanded to make the housing of the outdoor unit compact by arranging the refrigerant pipes as small as possible and arranging them in the machine room (see, for example, Patent Document 1).

In the technique described in Patent Document 1, the liquid pipe connection part and the gas pipe connection part are on the side panel of the housing, and each connection part is directed toward the rear of the housing of the outdoor unit, and is aligned in the vertical direction of the housing. are arranged side by side. As a result, according to the technique described in the document, the lateral dimension of the housing of the outdoor unit can be reduced.
Further, in the technique described in the document, the gas header is arranged diagonally to the right and forward of the liquid header. As a result, according to the technique described in the document, the dimension of the housing of the outdoor unit in the front-rear direction can be reduced. Furthermore, in the technique described in the same document, a plurality of liquid branch pipes are provided for connecting a plurality of connection ports connected to a plurality of indoor units by refrigerant pipes and a liquid header portion, and a part of the liquid branch pipe is By bending it upward at a predetermined angle, it is arranged obliquely with respect to the bottom plate of the housing, and the expansion valve is attached above the bent portion. As a result, according to the technique described in the document, the dimension in the height direction of the housing of the outdoor unit can be reduced.

JP 2017-180885 A

By the way, when connecting the above-described liquid pipe connection portion and the liquid header to which a plurality of liquid refrigerant pipes of the outdoor heat exchanger are connected by a liquid branch pipe, a straight pipe portion for attaching a temperature sensor to the liquid branch pipe is required. However, simply providing a straight pipe portion in the liquid branch pipe makes the liquid branch pipe larger in the longitudinal direction, the lateral direction, and the vertical direction of the outdoor unit. Therefore, in terms of piping in a compact manner, it is conceivable to provide the liquid branch pipe with a folded portion that is a combination of a straight pipe portion and a curved portion.
When the liquid branch pipe is provided with the folded portion as described above, the liquid branch pipe may vibrate with the curved portion of the folded portion as a fulcrum due to the fall or vibration of the outdoor unit. At this time, when a member such as an expansion valve is attached to a portion other than the folded portion of the liquid branch pipe, this member acts as a heavy object, thereby increasing the amplitude of the liquid branch pipe. In particular, the farther the member is placed from the folded portion, the greater the influence of the member on the vibration of the pipe.
Therefore, the present invention has been made by paying attention to such a problem. An object of the present invention is to provide an outdoor unit for an air conditioner that suppresses the

In order to solve the above problems, an air conditioner outdoor unit according to one aspect of the present invention is used in an air conditioner, and includes a connection port to which a plurality of indoor units are connected using refrigerant pipes, and a plurality of indoor units. the outdoor unit having the same number of expansion valves as the outdoor unit, wherein the connection port has a liquid pipe connection portion and a gas pipe connection portion, a liquid branch pipe connecting the liquid pipe connection portion and the expansion valve, and a gas and a gas branch pipe connected to the pipe connection portion, the expansion valve is provided in the liquid branch pipe, and the liquid branch pipe is curved so as to return from the liquid pipe connection portion side toward the expansion valve side. It has a folded portion including a curved portion and a straight pipe portion to which a temperature sensor can be attached, and a part of the folded portion is brought close to a part of the gas branch pipe and fixed by a restraining member. and

According to the outdoor unit for an air conditioner according to one aspect of the present invention, a straight pipe part to which a temperature sensor can be attached is provided in the middle of the folded part of the liquid branch pipe, and a part of the folded part is Since it is close to a part of the gas branch pipe and fixed with a restraining member, it is possible to attach the liquid side temperature sensor to the liquid branch pipe, and at the same time, it suppresses the vibration of the liquid branch pipe caused by the fall or vibration of the outdoor unit. .

1 is a block diagram illustrating a circuit of an air conditioner according to one aspect of the present invention; FIG. 1 is a perspective view of an outdoor unit for an air conditioner according to one aspect of the present invention, showing a state in which a cover member is removed. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the internal structure of the outdoor unit for air conditioners which concerns on one aspect|mode of this invention, (a) is a top view in the state which removed the top plate, (b) is a top view in which the front panel was removed. It is a front view of a state. Fig. 2 is a right side view for explaining the machine room of the outdoor unit for an air conditioner according to one aspect of the present invention, and shows a state in which the side panel is removed. 1 is a front perspective view of a machine room of an outdoor unit for an air conditioner according to one aspect of the present invention, and shows a state in which a service panel and a side panel are removed. FIG. FIG. 2 is a perspective view of the machine room of the outdoor unit for an air conditioner according to one aspect of the present invention, as seen from the rear upper side, and shows a state in which the service panel and the side panel are removed. 5 is an enlarged view of a main part of FIG. 4; FIG.

An embodiment of the present invention will be described below with appropriate reference to the drawings. This embodiment is an example of an air conditioner in which two indoor units are connected in parallel to one outdoor unit via refrigerant pipes, and each indoor unit can perform cooling operation or heating operation at the same time.
Note that the drawings are schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the planar dimensions are different from the actual ones, and the drawings include portions where the relationship and ratio of the dimensions are different from each other.
Further, the embodiments shown below are examples of devices and methods for embodying the technical idea of the present invention. etc. are not specified in the following embodiments.

As shown in FIG. 1, the air conditioner 1 according to the present embodiment includes one outdoor unit 2 to which two indoor units, an indoor unit 5A and an indoor unit 5B, can be connected. The indoor unit 5A is connected to the outdoor unit 2 through a liquid pipe 8L and a gas pipe 8G. The indoor unit 5B is connected to the outdoor unit 2 through a liquid pipe 9L and a gas pipe 9G.
Specifically, for the indoor unit 5A, one end of the liquid pipe 8L is connected to the liquid pipe connection portion 52L (corresponding to the first liquid pipe connection portion of the present invention) of the indoor unit 5A, and the liquid pipe 8L is connected to the liquid pipe connection portion 27L of the outdoor unit 2 . One end of the gas pipe 8G is connected to the gas pipe connection portion 52G of the indoor unit 5A, and the other end of the gas pipe 8G is connected to the gas pipe connection portion 27G of the outdoor unit 2.

For the indoor unit 5B, one end of the liquid pipe 9L is connected to the liquid pipe connection portion 53L (corresponding to the second liquid pipe connection portion of the present invention) of the indoor unit 5B, and the other end of the liquid pipe 9L is connected to the liquid pipe connection portion 53L of the indoor unit 5B. is connected to the liquid pipe connection portion 28L of the outdoor unit 2 .
One end of the gas pipe 9G is connected to the gas pipe connection portion 53G of the indoor unit 5B, and the other end of the gas pipe 9G is connected to the gas pipe connection portion 28G of the outdoor unit 2. In this manner, the indoor unit 5A and the indoor unit 5B are connected in parallel to the outdoor unit 2 to form the refrigerant circuit 100 of the air conditioner 1. FIG.

<Indoor unit configuration>
Next, each indoor unit 5A, 5B will be described.
Each of the indoor units 5A and 5B includes indoor heat exchangers 51a and 51b, liquid pipe connections 52L and 53L, gas pipe connections 52G and 53G, and indoor fans 54a and 54b, respectively.
Each of the indoor units 5A and 5B has indoor unit refrigerant circuits 50a and 50b, which are connected to each of these component devices (except for each of the indoor fans 54a and 54b) by refrigerant pipes described below, and form a part of the refrigerant circuit 100. to form Since the indoor units 5A and 5B have the same configuration, the indoor unit 5A will be described below, and the configuration of the indoor unit 5B will be omitted.

In the indoor unit 5A, one refrigerant inlet/outlet of the indoor heat exchanger 51a and the liquid pipe connection portion 52L are connected by the indoor unit liquid pipe 71a, and the other refrigerant inlet/outlet of the indoor heat exchanger 51a and the gas pipe connection portion 52G are connected. They are connected by an indoor unit gas pipe 72a.
Refrigerant pipes are connected to the liquid pipe connection portion 52L and the gas pipe connection portion 52G by welding, flare nuts, or the like. The indoor heat exchanger 51a functions as an evaporator when the indoor unit 5A performs cooling operation, and functions as a condenser when the indoor unit 5A performs heating operation.

The indoor fan 54a is a cross-flow fan made of a resin material and arranged near the indoor heat exchanger 51a. The indoor fan 54a is rotationally driven by a fan motor (not shown). In addition, the indoor unit 5A has a suction port and a discharge port, and the indoor heat exchanger 51a heat-exchanges the indoor air taken into the indoor unit 5A from the suction port by the rotation of the indoor fan 54a with the refrigerant, The indoor air that has exchanged heat with the refrigerant is blown into the room from the outlet.
Thereby, the room in which the indoor unit 5A is installed is heated or cooled. An indoor temperature sensor 61a is provided near the suction port of the indoor unit 5A. The indoor temperature sensor 61a detects the temperature of the indoor air flowing into the indoor unit 5A (that is, the indoor temperature).

<Configuration of outdoor unit>
Next, the outdoor unit 2 will be described in detail.
The outdoor unit 2 includes a rectangular parallelepiped housing 10, as shown in an overall perspective view of FIG. The housing 10 has a bottom plate 11 , a front panel 12 , a side panel 15 and a top plate 16 . The front panel 12 is formed by a grille 12a and a service panel 12b.
The side panel 15 also serves as part of the rear panel. Supports 17 are provided at the corners of the housing 10 (see FIG. 3B). The top and bottom of the support column 17, the front panel 12, and the side panel 15 are screwed to screwing portions provided at appropriate locations on the bottom plate 11 and the top plate 16, respectively.

In the following description, in the posture of the outdoor unit 2 shown in FIG. 2, the side on which the front panel 12 is arranged is the front side, and the opposite side is the back side, and when the front panel 12 is viewed from the front, the service panel 12b is The arranged side is the right side, and the opposite side is the left side. described as "vertical direction".

As shown in FIGS. 2 and 3, the outdoor unit 2 has a connection port 9 on the right side surface of the housing 10 for connecting the two indoor units 5A and 5B. The connection port 9 is covered with a cover member 7, as shown in FIG. The cover member 7 is a box-shaped member made of synthetic resin, and is detachably attached to the side panel 15 so as to cover a port panel 15a, which will be described later. The connection port 9 is formed by gas pipe connection portions 27G and 28G and liquid pipe connection portions 27L and 28L. The interior of the housing 10 is partitioned into the heat exchanger chamber 4 on the left side and the machine chamber 3 on the right side by a partition plate 18 (see FIG. 3).

The bottom plate 11 is a substantially rectangular steel plate, and as shown in FIG. 3, has a flange 11t bent upward at a substantially right angle at its peripheral edge. On the lower surface of the bottom plate 11, a total of four legs 11f are provided on the front, rear, left, and right sides to extend in the front-rear direction of the housing 10 and for installing the outdoor unit 2 on the ground or the like.
The grille 12a is formed in a lattice shape using a resin material or steel material, and as shown in FIG. placed.
The service panel 12 b is a substantially rectangular steel plate and is arranged to cover the front side of the machine room 3 . The service panel 12b is detachably attached so that the machine room 3 can be easily accessed during maintenance work on the outdoor unit 2. As shown in FIG.

The side panel 15 has a port panel 15a and a conduit panel 15b. The port panel 15a is made of a steel plate and is attached so as to cover the area where the connection port 9 on the right side of the housing 10 is arranged. The connection port 9 is arranged on the port panel 15a so as to protrude outward on the right side. The conduit panel 15b is a substantially rectangular steel plate and is attached to the right side surface of the housing 10 so as to cover the peripheral opening of the port panel 15a.
As shown in FIG. 3 , an outdoor heat exchanger 23 and an outdoor fan 26 are arranged in the heat exchanger chamber 4 inside the housing 10 . The outdoor fan 26 is a propeller fan made of a resin material and arranged in front of the outdoor heat exchanger 23 . The outdoor fan 26 is attached to the output shaft of the motor 29 and is attached to the motor support portion 30 to which the motor 29 is fixed to the outdoor heat exchanger 23 .

As shown in FIG. 3A, the outdoor heat exchanger 23 is formed in a substantially L shape when viewed from the top, and is arranged to cover the entire surface from the left side to the back of the housing 10 . As described above, the outdoor fan 26 is arranged in front of the outdoor heat exchanger 23 so as to face it. The outdoor heat exchanger 23 heat-exchanges the outside air taken into the housing 10 of the outdoor unit 2 from the suction port 3 s by rotation of the outdoor fan 26 by the motor 29 , and the refrigerant flows through the outdoor heat exchanger 23 . The outside air that has exchanged heat with the refrigerant is discharged to the outside from the outlet 2 f provided in the heat exchanger chamber 4 .

As shown in FIGS. 3 to 6, the machine room 3 inside the housing 10 is provided with a compressor 21, a four-way valve 22, two expansion valves 24a and 24b, and an accumulator 25. FIG. These devices (except for the outdoor fan 26) are connected to each other by refrigerant pipes, which will be described in detail below, and constitute the outdoor unit refrigerant circuit 20 forming part of the refrigerant circuit 100 described above. The expansion valve 24a corresponds to the first expansion valve of the present invention, and the expansion valve 24b corresponds to the second expansion valve of the present invention.
In the machine room 3, a cylindrical compressor 21 is arranged on the upper surface of the bottom plate 11 with the axis of the cylinder vertical, with three vibration-isolating insulators (not shown) interposed therebetween. This compressor 21 is a variable capacity compressor that can vary its operating capacity. The compressor 21 is configured to be driven by a motor 29, and its rotation speed is controlled by an inverter.

Here, as shown in FIG. 3, the arrangement position of the compressor 21 of the present embodiment in the machine room 3 is such that the front-rear direction is closer to the front service panel 12b and the left-right direction is closer to the heat exchanger chamber 4. It is arranged at a position near the partition plate 18 .
As a result, the plurality of indoor units are arranged between the compressor 21 and the side panel 15 in the lateral direction of the machine room 3 and between the compressor 21 and the outdoor heat exchanger 23 in the longitudinal direction of the machine room 3. Space required to accommodate refrigerant pipes connected to 5A and 5B via connection ports is secured.

As shown in FIG. 5, the compressor 21 has a discharge pipe 41 connected to a refrigerant discharge port at the center of the upper portion of the compressor 21, and a suction pipe 42 connected to a refrigerant suction port at the lower side surface of the compressor 21. . As shown in FIG. 1, the refrigerant discharge port of the compressor 21 and the port a of the four-way valve 22 are connected by a discharge pipe 41, and the refrigerant suction port of the compressor 21 and the refrigerant outlet port of the accumulator 25 are connected to the suction pipe. 42.
The accumulator 25 has a cylindrical shape smaller than the outer diameter of the compressor 21 and is attached to the compressor 21 with a restraint band with its axis vertical at a position on the right side of the compressor 21 . As shown in FIG. 4, a refrigerant pipe 46 is connected to the refrigerant inlet at the center of the upper portion of the accumulator 25. As shown in FIG. Connected.

Further, as described above, the refrigerant outlet at the center of the lower portion of the accumulator 25 is connected to the refrigerant suction port of the compressor 21 through the suction pipe 42 . As a result, the accumulator 25 separates the refrigerant that has flowed into itself into gas refrigerant and liquid refrigerant, and causes the compressor 21 to suck only the gas refrigerant through the suction pipe 42 .
The four-way valve 22 is a switching valve for switching the direction of refrigerant flow. The four-way valve 22 is provided at a position closer to the rear of the machine room 3 and higher than the top of the accumulator 25, as shown in FIGS.
The four-way valve 22 has four ports a, b, c, and d, as shown in FIG. The port a of the four-way valve 22 is connected to the refrigerant discharge port of the compressor 21 through the discharge pipe 41 as described above. The port b of the four-way valve 22 is connected to one refrigerant inlet/outlet of the outdoor heat exchanger 23 through the refrigerant pipe 43, and the port c is connected to the refrigerant inlet of the accumulator 25 through the refrigerant pipe 46 as described above. be.

Furthermore, the port d is connected to one end of the outdoor unit gas pipe 45 . The four-way valve 22 switches the direction of refrigerant flow in the refrigerant circuit 10, more specifically, the direction of refrigerant flow in the indoor heat exchangers 51a and 51b of the indoor units 5A and 5B. The four-way valve 22 switches the direction of refrigerant flow, thereby configuring the outdoor unit refrigerant circuit 20 in which the indoor heat exchangers 51a and 51b are switched to function as condensers or evaporators.
One end of each of the two gas branch pipes 45 a and 45 b is connected to the other end of the outdoor unit gas pipe 45 . The other end of the gas branch pipe 45a is connected to the gas pipe connection portion 27G, and the other end of the gas branch pipe 45b is connected to the gas pipe connection portion 28G.
One end of an outdoor unit liquid pipe 44 is connected to the other refrigerant inlet/outlet of the outdoor heat exchanger 23 . The outdoor heat exchanger 23 functions as a condenser when the refrigerant circuit 100 is in the cooling cycle, and functions as an evaporator when the refrigerant circuit 100 is in the heating cycle.

The outdoor unit 2 of the present embodiment is provided with an expansion valve 24a for the indoor unit 5A and an expansion valve 24b for the indoor unit 5B as expansion valves. One end of each of the two liquid branch pipes 44 a and 44 b is connected to the other end of the outdoor unit liquid pipe 44 . The other end of the liquid branch pipe 44a is connected to the liquid pipe connection portion 27L, and the expansion valve 24a is incorporated in the liquid branch pipe 44a. The other end of the liquid branch pipe 44b is connected to the liquid pipe connection portion 28L, and the liquid branch pipe 44 incorporates the expansion valve 24b.

Each of the expansion valves 24a, 24b is a coil-type solenoid valve driven by a built-in solenoid. Although not shown, an expansion valve main body to which the liquid branch pipes 44a and 44b are connected when they are incorporated into the liquid branch pipes 44a and 44b, and a valve body in the expansion valve main body are slid along the axial direction. and a solenoid portion that is movably driven. The solenoid portion of each expansion valve 24a, 24b is attached to the upper portion of the expansion valve body. The expansion valve main body is arranged so that its movable axis is in the vertical direction.

The solenoids of the expansion valves 24a and 24b are installed so that they can be manually removed from the upper space of the machine room 3, that is, they do not overlap each other when viewed from above. Specifically, the expansion valve 24a is installed at a position closer to the front (position closer to the compressor) in the housing 10 than the expansion valve 24b.
The opening degrees of the expansion valves 24a and 24b are adjusted by the solenoid portions of the expansion valves 24a and 24b, respectively, so that the amounts of refrigerant flowing through the indoor units 5A and 5B can be adjusted.

Furthermore, the outdoor unit 2 is provided with various sensors.
As shown in FIG. 1, the discharge pipe 41 includes a high-pressure sensor 31 that detects the pressure of the refrigerant discharged from the compressor 21, a discharge temperature sensor 33 that detects the temperature of the refrigerant discharged from the compressor 21, is provided.
A low-pressure sensor 32 for detecting the pressure of the refrigerant sucked into the compressor 21 and a suction temperature sensor 34 for detecting the temperature of the refrigerant sucked into the compressor 21 are provided in the refrigerant pipe 46 near the refrigerant inlet of the accumulator 25 . and are provided. In the following description, the pressure of the refrigerant discharged from the compressor 21 may be described as "high pressure", and the pressure of the refrigerant sucked into the compressor 21 may be described as "low pressure".

Furthermore, a refrigerant temperature sensor 35 is provided in the vicinity of the outdoor heat exchanger 23 in the outdoor unit liquid pipe 44 . The refrigerant temperature sensor 35 detects the temperature of the refrigerant flowing into the outdoor heat exchanger 23 or the temperature of the refrigerant flowing out of the outdoor heat exchanger 23 . An outside air temperature sensor 38 is provided near the suction port 2f of the outdoor unit 2. As shown in FIG. The outside air temperature sensor 38 detects the temperature of the outside air flowing into the housing 10 of the outdoor unit 2 (that is, the outside air temperature).

Further, the liquid branch pipe 44a is provided with a liquid side temperature sensor 36a at a position between the expansion valve 24a and the liquid pipe connecting portion 27L. As shown in FIG. 7, the liquid-side temperature sensor 36a includes a bottomed cylindrical metal outer cylinder closed at one end in the axial direction, and the outer cylinder is sealed with a filling resin and has leads. A thermistor for an air conditioner having a thermistor element to which a wire is connected. The liquid-side temperature sensor 36a has an outer cylinder fixed in close contact with the outer peripheral surface of the liquid branch pipe 44a to be detected, so that the temperature of the refrigerant flowing through the liquid branch pipe 44a can be detected.
The liquid branch pipe 44b is provided with a liquid side temperature sensor 36b at a position between the expansion valve 24b and the liquid pipe connecting portion 28L. The liquid side temperature sensor 36b is an air conditioner thermistor having the same configuration as the liquid side temperature sensor 36a. The temperature of the coolant flowing through the pipe 44b can be detected.

A gas-side temperature sensor 37a is provided in the gas branch pipe 45a. As shown in FIG. 7, the gas-side temperature sensor 37a includes a bottomed cylindrical metal outer cylinder closed at one end in the axial direction, and a lead that is contained in the outer cylinder in a sealed state with filling resin. and a thermistor element to which a wire is connected. The gas-side temperature sensor 37a is fixed to the outer peripheral surface of the gas branch pipe 45a to be detected so that the outer cylinder is in close contact with the gas branch pipe 45a, so that the temperature of the refrigerant flowing through the gas branch pipe 45a can be detected.
A gas side temperature sensor 37b is provided in the gas branch pipe 45b. The gas side temperature sensor 37b is an air conditioner thermistor having the same configuration as the gas side temperature sensor 37a. The temperature of the coolant flowing through 45b can be detected.

<Shape and arrangement of liquid branch pipes in the machine room>
Next, the arrangement of the liquid branch pipes 44a, 44b and the gas branch pipes 45a, 45b in the machine room 3 of the outdoor unit 2 of this embodiment will be described in more detail.
In this embodiment, the liquid branch pipes 44a and 44b are connected at one end to respective liquid pipe connection portions 27L and 28L, which will be described later, and return toward the expansion valves 24a and 24b, as shown enlarged in FIG. It has folded portions A and B curved in a substantially U shape. When forming the folded portions A and B, if the radius of curvature of each of the folded portions A and B, which will be described later, is at least twice the outer diameter of the liquid branch pipes 44a and 44b, each The folded portions A and B can be formed without damaging the liquid branch pipes 44a and 44b.
The outer cylinders of the liquid-side temperature sensors 36a and 36b having cylindrical outer cylinders are formed in the intermediate portions of the folded portions A and B so as to have a length that allows them to be attached in close contact with the outer circumferences of the liquid-side temperature sensors 36a and 36b. (A portion _44a1 in the folded portion A and a portion _44b1 in the folded portion B, as will be described later).

Specifically, the connection port 9 includes a liquid pipe connection portion 27L to which the other end of the liquid pipe 8L connected to the indoor unit 5A is connected, and a liquid pipe 9L having one end connected to the indoor unit 5B. A liquid branch pipe 44a having a straight pipe portion 44a ₁ at the folded portion A and a liquid pipe connecting portion 28L connected at one end thereof has one end connected to the liquid pipe connecting portion 27L and a straight pipe portion 44b at the folded portion B. One end of the liquid branch tube 44b having ₁ is connected to the second liquid tube connection portion 28L. The other ends of the liquid branch pipes 44 a and 44 b are connected to the outdoor heat exchanger 23 via the outdoor unit liquid pipe 44 .

The folded portion A of the liquid branch pipe 44a includes a straight pipe portion 44a _{1 extending from the liquid pipe connection portion 27L toward the front side of the housing 10 of the outdoor unit 2 in parallel with the bottom plate 11, and the front side of the straight pipe portion 44a 1 .} A first curved portion 44a ₂ formed by bending downward, an inclined portion 44a ₃ extending obliquely downward from the tip of the first curved portion 44a 2 toward the rear surface side _of the housing 10 of the outdoor unit 2, A horizontal portion 44a ₄ extending parallel to the bottom plate 11 from the tip of the inclined portion 44a ₃ toward the rear surface side of the housing 10 of the outdoor unit 2 and the tip of the horizontal portion 44a ₄ are formed by bending the tip of the horizontal portion 44a ₄ upward. and a vertical portion 44a ₆ extending upward from the tip of the second curved portion 44a ₅ along the central axis of the expansion valve 24a _and connected to the expansion valve 24a.

Further, in the present embodiment, the folded portion B of the second liquid branch pipe 44b extends parallel to the bottom plate 11 from the liquid pipe connection portion 28L toward the front side of the housing 10 of the outdoor unit 2 from the expansion valve 24b. A tubular portion 44b ₁ , a first curved portion 44b ₂ formed by bending the front side of the straight tubular portion 44b ₁ downward, and a rear surface of the housing 10 of the outdoor unit ₂ extending from the tip of the first curved portion 44b 2 . A first horizontal portion 44bh extending parallel to the bottom plate 11 toward the side, an inclined portion 44b ₃ extending obliquely downward from a position where the tip of the first horizontal portion 44bh faces rearward, and the tip of the inclined portion 44b ₃ A second horizontal portion 44b4 extending parallel to the bottom plate ₁₁ from a position facing the rear surface, and a second curved portion formed by bending the tip of the second horizontal portion _44b4 upward at the position of the axis of the expansion valve 24b. 44b ₅ and a vertical portion 44b ₆ extending upward along the central axis of the expansion valve 24b from the tip where the second curved portion 44b ₅ faces upward and connected to the expansion valve 24b.

Furthermore, in this embodiment, the horizontal portions 44a4 and _44b4 of the folded portions A and B of the liquid branch pipes 44a and _44b are parallel to the horizontal portions 45as and 45bs of the gas branch pipes 45a and 45b. is provided as follows. A cylindrical cushioning member 39 is wound around _{each of the horizontal portions 44a 4 and} 44b _{4 .} Horizontal portions 45as and 45bs of the gas branch pipes 45a and 45b are fixed by a restraining member 40 such as a restraining band.

In this embodiment, the horizontal portions 44a 4 and 44b 4 of the liquid branch pipes 44a and 44b and the horizontal portions 45as and 45bs of the gas branch pipes 45a and 45b, which are parallel to the horizontal portions 44a ₄ and 44b ₄ , are arranged parallel to each other when viewed from above. Alternatively, the pipes may be laid so as to intersect, and the position to be fixed by the restraining member 40 is any parallel point if they are arranged in parallel, and if they are arranged so as to intersect should intersect.

<Operation of refrigerant circuit>
Next, the flow of the refrigerant and the operation of each part in the refrigerant circuit 100 when the air conditioner 1 of the present embodiment performs air conditioning operation will be described with reference to FIG. 1 as appropriate.
In the following description, a case where each of the indoor units 5A and 5B performs heating operation will be described, and a detailed description of a case where the air conditioner 1 performs cooling operation will be omitted. Arrows shown in FIG. 1 indicate the flow of refrigerant in the refrigerant circuit 100 during heating operation.

When the air conditioner 1 performs the heating operation, the four-way valve 22 is set so that the port a and the port d of the four-way valve 22 communicate with each other, and the port b and the port c communicate with each other, as indicated by the solid line in FIG. can be switched to 1, the outdoor heat exchanger 23 functions as an evaporator, and the indoor heat exchangers 51a and 51b function as condensers. becomes a cycle.

When the compressor 21 is started while the refrigerant circuit 100 is in the heating cycle, the high-pressure refrigerant discharged from the compressor 21 flows from the discharge pipe 41 into the four-way valve 22 and flows from the four-way valve 22 through the outdoor unit gas pipe 45. to separate the gas branch pipes 45a and 45b. The refrigerant branched to the gas branch pipes 45a and 45b flows into the gas pipes 8G and 9G via the gas pipe connection portions 27G and 28G.
The refrigerant flowing through the gas pipe 8G flows into the indoor unit 5A via the gas pipe connection portion 52G of the indoor unit 5A. The refrigerant that has flowed into the indoor unit 5A flows into the indoor heat exchanger 51a through the indoor unit gas pipe 72a, exchanges heat with the indoor air taken into the indoor unit 5A by the rotation of the indoor fan 54a, and condenses. do.

Also, the refrigerant flowing through the gas pipe 9G flows into the indoor unit 5B via the gas pipe connection portion 53G of the indoor unit 5B. The refrigerant that has flowed into the indoor unit 5B flows into the indoor heat exchanger 51b through the indoor unit gas pipe 72b, and exchanges heat with the indoor air taken into the indoor unit 5B by the rotation of the indoor fan 54b. condense.
Thus, the indoor heat exchangers 51a and 51b of the indoor units 5A and 5B function as condensers, respectively, and the indoor air heat-exchanged with the refrigerant in the indoor heat exchangers 51a and 51b is The air is blown into the room from the outlets of 5A and 5B, thereby heating the rooms in which the indoor units 5A and 5B are installed.
The refrigerant flowing out of the indoor heat exchanger 51a flows through the indoor unit liquid pipe 71a and flows out to the liquid pipe 8L through the liquid pipe connecting portion 52L. The refrigerant flowing through the liquid pipe 8L flows into the outdoor unit 2 via the liquid pipe connection portion 27L, and flows into the liquid branch pipe 44a from the liquid pipe connection portion 27L.

Also, the refrigerant flowing out of the indoor heat exchanger 51b flows through the indoor unit liquid pipe 71b and flows out to the liquid pipe 9L via the liquid pipe connecting portion 53L. The refrigerant flowing through the liquid pipe 9L flows into the outdoor unit 2 via the liquid pipe connection portion 28L, and flows into the liquid branch pipe 44b from the liquid pipe connection portion 28L.
The refrigerants flowing through the respective liquid branch pipes 44 a and 44 b are depressurized by the respective expansion valves 24 a and 24 b and join together in the outdoor unit liquid pipe 44 . The refrigerant merged in the outdoor unit liquid pipe 44 flows through the outdoor unit liquid pipe 44 and flows into the outdoor heat exchanger 23 .

The refrigerant that has flowed into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 26 and evaporates. Refrigerant flowing from the outdoor heat exchanger 23 to the refrigerant pipe 43 flows through the four-way valve 22, the refrigerant pipe 46, the accumulator 25, and the suction pipe 42 in this order, is sucked into the compressor 21, and is compressed again.
When the air conditioner 1 performs cooling operation, the four-way valve 22 is in the state indicated by the dashed line in FIG. are switched so that the Thereby, the refrigerant circuit 100 becomes a cooling cycle in which the outdoor heat exchanger 23 functions as a condenser and the indoor heat exchangers 51a and 51b function as evaporators.

<Effects of the shape and arrangement of the liquid branch pipe in the outdoor unit according to the present embodiment>
Next, with reference to FIGS. 2 to 7, the effects of the shape and arrangement of the liquid branch pipes in the machine room 3 in the outdoor unit 2 of this embodiment will be described.
Refrigerant piping in the so-called multi-model machine room 3 as in this embodiment includes a plurality of expansion valves 24a, 24b, piping connection portions 27G, 28G and 27L, 28L, and each piping 41 to 46 as compact as possible. Therefore, it is required to accommodate each pipe in the limited space of the machine room 3.
In particular, the housing of the outdoor unit to which only one indoor unit is connected is replaced by an outdoor unit to which a plurality of indoor units can be connected, for example, two indoor units 5A like the air conditioner 1 of the present embodiment. , 5B are connected to the outdoor unit 2 to reduce the size of the outdoor unit 2, there are the following problems (1) to (4).

Problem (1) In realizing the outdoor unit 2 to which a plurality of indoor units can be connected, the limited space in the machine room 3 (the space between the compressor 21 and the side panel 15 and the space between the compressor 21 and the outdoor heat exchanger 23) to accommodate the liquid branch pipes 44a and 44b connected from the connection port 9 to the two expansion valves 24a and 24b, respectively.
Problem (2) However, when the liquid branch pipes 44a and 44b are laid, it is necessary to provide each of the liquid branch pipes 44a and 44b with a straight pipe portion for attaching the liquid side temperature sensors 36a and 36b.
Problem (3) However, if a straight pipe portion is simply provided in each of the liquid branch pipes 44a and 44b, each of the liquid branch pipes 44a and 44b becomes large in the longitudinal direction, the lateral direction, and the vertical direction of the outdoor unit 2, resulting in a compact structure. , the liquid branch pipes 44a and 44b cannot be arranged.
Problem (4) Therefore, if the folded portions A and B are provided like the liquid branch pipes 44a and 44b of the present embodiment, the liquid branch pipes 44a and 44b can be arranged compactly, but the folded portions A and B should be provided with the first curved portions 44a ₂ and 44b ₂ . In particular, since the expansion valves 24a and 24b are connected to the respective liquid branch pipes 44a and 44b, the first curved portions 44a ₂ and 44b ₂ are used as fulcrums when the outdoor unit 2 is dropped or subjected to vibration. , the weight of the expansion valves 24a and 24b greatly shakes the liquid branch pipes 44a and 44b, which may damage the liquid branch pipes 44a and 44b.

In order to solve all of the above problems (1) to (4), the outdoor unit 2 of this embodiment, as shown in FIG. The branch pipes 44a and 44b have folded portions A and B including curved portions formed by bending. A straight pipe portion (44a1 portion in the folded portion A, _44b1 portion in the folded portion B) is provided with a length that allows the outer cylinders of the side temperature sensors 36a and _36b to be attached in close contact with each other.
As a result, according to the outdoor unit 2 of the present embodiment, the liquid-side temperature sensors 36a and 36b can be mounted on the pipes, and at the same time, by providing a folded portion or the like to form a straight pipe portion, the heat of the housing 10 can be reduced. A compact pipeline arrangement that fits in the limited space in the exchanger chamber 4 can be achieved.

As an example, the liquid branch pipes 44a and 44b in the outdoor unit 2 of the present embodiment have one ends connected to the liquid pipe connection portions 27L and 28L, and are substantially U-shaped so as to return toward the expansion valves 24a and 24b. It has folded portions A and B that are curved in shape. When forming the folded portions A and B, if the radius of curvature of each of the folded portions A and B is set to be at least twice the outer diameter of the liquid branch pipes 44a and 44b, then each liquid branch The folded portions A and B can be formed without damaging the pipes 44a and 44b.

Further, in the outdoor unit 2 of the present embodiment, the outer cylinders of the liquid-side temperature sensors 36a and 36b having cylindrical outer cylinders are arranged in the middle of the folded parts A and B. A straight pipe portion (a portion 44a ₁ in the folded portion A and a portion 44b ₁ in the folded portion B, as will be described later) is provided.
As a result, according to the outdoor unit 2 of the present embodiment, the liquid pipe connection portions 27L and 28L and the gas pipe connection portion 27G with the indoor units 5A and 5B are arranged so as to fit in the limited space inside the machine room 3. , 28G to the expansion valves 24a and 24b, and each piping and each temperature sensor are arranged inside the machine room 3. As shown in FIG. Therefore, compared to the case where the liquid-side temperature sensors 36a and 36b are arranged in the horizontal direction and the vertical direction of the outdoor unit, the dimensions in the vertical direction or the front-rear direction can be reduced.

Regarding the problem (4), in the outdoor unit 2 of the present embodiment, the liquid branch pipes 44a and 44b and the gas branch pipes 45a and 45b are shaped and arranged as described below. and the horizontal portion _45as of the gas branch pipe 45a, and the horizontal portion _44b4 of the liquid branch pipe 44b and the horizontal portion 45bs of the gas branch pipe 45b. Therefore, even if the outdoor unit 2 is dropped or subjected to vibration, the liquid branch pipes 44a and 44b can be prevented from vibrating, and the liquid branch pipes 44a and 44b can be prevented from being damaged.

That is, in this embodiment, the liquid branch pipes 44a and 44b are fixed to the gas branch pipes 45a and 45b from the following (1) to (4) viewpoints.
(1) The strength of the liquid branch pipes 44a and 44b is weaker than that of the gas branch pipes 45a and 45b because the diameter of the liquid branch pipes 44a and 44b is smaller than that of the gas branch pipes 45a and 45b.
(2) The heavy expansion valves 24a and 24b are attached to the liquid branch pipes 44a and 44b, which are weaker than the gas branch pipes 45a and 45b.
(3) Due to the reasons (1) and (2) above, the liquid branch pipes 44a and 44b are susceptible to vibration.
(4) Therefore, the liquid branch pipes 44a and 44b are fixed to the strong gas branch pipes 45a and 45b.

In the outdoor unit 2 of the present embodiment, one end is connected to each of the liquid pipe connection portions 27L and 28L, and the folded portions A and B are bent in a substantially U shape so as to return toward the expansion valves 24a and 24b. have. When forming the folded portions A and B, if the radius of curvature of each of the folded portions A and B is set to be at least twice the outer diameter of the liquid branch pipes 44a and 44b, then each liquid branch The folded portions A and B can be formed without damaging the pipes 44a and 44b.

Further, in the outdoor unit 2 of the present embodiment, the folded portions A and B of the respective liquid branch pipes 44a and 44b include straight pipe portions 44a ₁ and 44b ₁ extending horizontally forward from the liquid pipe connecting portions 27L and 28L, First curved portions 44a ₂ and 44b ₂ formed by bending the front sides of the straight tube portions 44a ₁ and 44b ₁ downward, and positions where the tips of the first curved portions 44a ₂ and 44b ₂ are directed rearward. Horizontal portions 44a ₄ and 44b ₄ extend horizontally rearward from the expansion valves 24a _{and 24b} . Straight tube portions 44a ₁ and 44b ₁ are formed so that _the liquid-side temperature sensors 36a and _36b can be mounted.

Further, according to the outdoor unit 2 of the present embodiment, the folded portions A and B of the respective liquid branch pipes 44a and 44b are, as shown in FIG _. , 44b ₄ are provided parallel to the horizontal portions 45as and 45bs which are part of the gas branch pipes 45a, 45b located below them, and the horizontal portions 44a ₄ , 44b ₄ of the liquid branch pipes 44a, 44b are parallel thereto. A buffer member 39 is wound around the horizontal portions 45as and 45bs of the gas branch pipes 45a and 45b, and fixed by being restrained by a restraining member 40. As shown in FIG. Therefore, even if the outdoor unit 2 is dropped or subjected to vibration, the liquid branch pipes 44a and 44b can be prevented from vibrating, and the liquid branch pipes 44a and 44b can be prevented from being damaged.

Further, in the outdoor unit 2 of the present embodiment, the expansion valves 24a and 24b are installed vertically with the axes of the expansion valves 24a and 24b, and the solenoid portion is installed on the upper part of the expansion valve main body. The solenoid parts 24b are installed so that they can be manually removed from the upper space of the machine room 3, for example, so that they do not overlap each other when viewed from above. Specifically, the expansion valve 24a is installed at a position closer to the front (position closer to the compressor) in the housing 10 than the expansion valve 24b. For this reason, the attachment and detachment work of each solenoid portion is facilitated, and maintenance is also excellent.

As described above, according to the outdoor unit 2 of the air conditioner 1 of the present embodiment, refrigerant pipes corresponding to the plurality of indoor units 5A and 5B are installed in the limited space inside the machine room 3 of the housing 10. A compact conduit arrangement that can accommodate It should be noted that the multi-model outdoor unit according to the present invention is not limited to the above-described embodiment, and of course various modifications are possible without departing from the gist of the present invention.

1 air conditioner 2 outdoor unit 2f (outdoor unit) outlet 3 machine room 3s (outdoor unit) inlet 4 heat exchanger chamber 5A indoor unit 5B indoor unit 6 blowout grill 7 cover members 8G, 9G gas pipe 8L, 9L liquid pipe 9 connection port 10 housing 11 bottom plate 11f leg portion 11t flange 12 front panel 12a grill 12b service panel 15 side panel 15a port panel 15b conduit panel 16 top plate 17 column 18 partition plate 20 outdoor unit refrigerant circuit 21 compressor 22 Four-way valve 23 Outdoor heat exchanger 24a First expansion valve 24b Second expansion valve 25 Accumulator 26 Outdoor fans 27G, 28G (outdoor unit) gas pipe connection portions 27L, 28L (outdoor unit) liquid pipe connection portion 29 motor 30 motor Supporting portion 31 High pressure sensor 32 Low pressure sensor 33 Discharge temperature sensor 34 Suction temperature sensor 35 Refrigerant temperature sensor 36a Liquid side temperature sensor 36b Liquid side temperature sensor 37a Gas side temperature sensor 37b Gas side temperature sensor 38 Outside air temperature sensor 39 Buffer member 40 Restricting member 41 Discharge pipe 42 Suction pipe 43 Refrigerant pipe 44 Outdoor unit liquid pipe 44a First liquid branch pipe 44b Second liquid branch pipe 45 Outdoor unit gas pipe 45a First gas branch pipe 45b Second gas branch pipe 45as (First gas branch pipe Horizontal portion 45bs (of the second gas branch pipe) Horizontal portion 46 Refrigerant pipe 50a Indoor unit refrigerant circuit 50b Indoor unit refrigerant circuit 51a Indoor heat exchanger 51b Indoor heat exchangers 52G, 53G (Indoor unit) gas pipe connection 52L, 53L (indoor unit) liquid pipe connection 54a indoor fan 54b indoor fan 61a indoor temperature sensor 61b indoor temperature sensor 71a indoor unit liquid pipe 71b indoor unit liquid pipe 72a indoor unit gas pipe 72b indoor unit gas pipe 100 refrigerant circuit A Folded portion B (of first liquid branch pipe) Folded portion (of second liquid branch pipe)

Claims (3)

An outdoor unit used in an air conditioner and having a connection port to which a plurality of indoor units are connected using refrigerant pipes, and the same number of expansion valves as the plurality of indoor units,
The connection port has a liquid pipe connection portion and a gas pipe connection portion, and includes a liquid branch pipe connecting the liquid pipe connection portion and the expansion valve, and a gas branch pipe connected to the gas pipe connection portion. wherein the expansion valve is provided in the liquid branch pipe,
The liquid branch pipe has a folded portion including a curved portion that is curved so as to return from the liquid pipe connecting portion side toward the expansion valve side, and a straight pipe portion to which a temperature sensor can be attached,
A portion of the folded portion and the gas branch pipe are fixed by a restraining member ,
The folded portion of the liquid branch pipe includes the straight pipe portion extending forward in the horizontal direction from the liquid pipe connection portion, a first curved portion formed by bending the front side of the straight pipe portion downward, and the a horizontal portion extending rearward from a position where the tip of the first curved portion faces rearward so as to be parallel to a portion of the gas branch pipe and fixed by the restraining member; and a vertical portion curved upward at the position of the axis and connected to the expansion valve. As the indoor unit, having a first indoor unit and a second indoor unit,
The connection port is provided with a first liquid pipe connection portion for the first indoor unit and a second liquid pipe connection portion for the second indoor unit as the liquid pipe connection portions,
The outdoor unit for an air conditioner according to claim 1, wherein the liquid branch pipe is connected to each of the first liquid pipe connection portion and the second liquid pipe connection portion. The expansion valve includes a first expansion valve for the first indoor unit and a second expansion valve for the second indoor unit,
Each of the expansion valves has an expansion valve main body and a solenoid section for slidably driving a valve element inside the expansion valve main body, and the solenoid section of each expansion valve is connected to the expansion valve main body. It is mounted on the upper part, and the movable shaft of the solenoid part is installed along the vertical direction,
The first expansion valve is installed at a higher position in the housing than the solenoid portion of the second expansion valve so that the solenoid portion of the first expansion valve can be manually removed from the upper space. 3. The outdoor unit for an air conditioner according to claim 1 , wherein the movable shaft of the first expansion valve is installed at a position closer to the front side in the housing than the movable shaft of the second expansion valve.

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