WO2023037972A1

WO2023037972A1 - Compressor, and air conditioning device

Info

Publication number: WO2023037972A1
Application number: PCT/JP2022/033072
Authority: WO
Inventors: 絵夢加藤; ちひろ遠藤; 遼介和田; 裕也砂原; 洪一入川
Original assignee: ダイキン工業株式会社
Priority date: 2021-09-10
Filing date: 2022-09-02
Publication date: 2023-03-16
Also published as: JP2023040761A

Abstract

Provided is a compressor in which damage to a valve main body is suppressed. A compressor (21) is provided with a compressing mechanism (15), an injection valve (93), and an injection pipe (92). A compression chamber (40) is formed in the compressing mechanism (15). The injection valve (93) is disposed in an injection passage (84g) that communicates with the compression chamber (40). The injection pipe (92) supplies a refrigerant to the injection passage (84g). The injection valve (93) includes a valve main body (94), a valve guard (95), and a valve seat (96). The valve main body (94) is disposed so as to be movable in a first direction (D1). The valve guard (95) restricts movement of the valve main body (94) toward the injection pipe (92). The valve seat (96) restricts movement of the valve main body (94) toward the compression chamber (40). A first hole (95a) that is opened and closed by means of the valve main body (94) is formed in the valve guard (95). A first distance (L), which is an amount of movement of the valve main body (94) in the first direction (D1), is less than a first dimension (t), which is a dimension of the valve main body (94) in the first direction (D1).

Description

Compressor and air conditioner

Regarding compressors and air conditioners.

As described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2016-17464), a scroll compressor having an injection passage for supplying refrigerant having a pressure between a low pressure and a high pressure in a refrigeration cycle to a compression chamber is known. there is The injection passage is provided with a check valve for closing the injection passage when the pressure of the injected refrigerant is lower than the pressure of the compression chamber.

During the process of compressing the refrigerant in the compression chamber, the valve body of the check valve repeatedly collides with the member that restricts the movement of the valve body, which may damage the valve body.

The compressor of the first aspect includes a compression mechanism, an injection valve, and an injection pipe. The compression mechanism has a compression chamber in which refrigerant is compressed. The injection valve is arranged in the injection passage communicating with the compression chamber. The injection pipe supplies coolant to the injection passage. The injection valve has a valve body, a valve guard, and a valve seat. The valve body is arranged movably along the first direction. The valve guard is arranged closer to the injection pipe than the valve body, and restricts movement of the valve body toward the injection pipe. The valve seat is arranged closer to the compression chamber than the valve body, and restricts movement of the valve body toward the compression chamber. The valve guard is formed with a first hole that is opened and closed by the valve body. A first distance that is the amount of movement of the valve body in the first direction when the valve body moves from the first state in which the valve body contacts the valve guard and closes the first hole to the second state in which the valve body separates from the valve guard and contacts the valve seat. is less than the first dimension, which is the dimension of the valve body in the first direction.

In this compressor, by reducing the impact load on the valve body and increasing the fatigue strength of the valve body, damage to the valve body is suppressed and the reliability of the compressor is improved.

The compressor of the second aspect is the compressor of the first aspect, where L is the first distance and t is the first dimension, satisfying the relational expression 0.2 mm ≤ L < t ≤ 1.8 mm .

With this compressor, damage to the valve body is suppressed.

The compressor of the third aspect is the compressor of the first aspect or the second aspect, wherein S1 is the area of the valve body when viewed along the first direction, and S1 is the area of the valve body when viewed along the first direction. When the area of the first hole is S2, the relational expression 4.1≤S1/S2≤4.9 is satisfied.

　In this compressor, the sealing performance of the injection valve is properly ensured.

The compressor of the fourth aspect is the compressor of any one of the first to third aspects, and the valve body is made of spring steel.

With this compressor, damage to the valve body is suppressed.

The compressor of the fifth aspect is the compressor of any one of the first to fourth aspects, and the compression mechanism has a piston and vanes. The vane contacts the piston and divides the compression chamber into a first chamber and a second chamber. The vanes are held reciprocally while the refrigerant is compressed in the compression chamber.

With this compressor, even if the pressure difference before and after the injection valve is relatively high, damage to the valve body is suppressed.

A compressor according to the sixth aspect is the compressor according to any one of the first to fourth aspects, and the compression mechanism has a vane and a pair of bushes. A vane partitions the compression chamber into a first chamber and a second chamber. The vane is held between the pair of bushes so as to be able to move forward and backward while the refrigerant is compressed in the compression chamber.

The air conditioner of the seventh aspect comprises any one of the compressors of the first to sixth aspects.

In this air conditioner, damage to the injection valve of the compressor is suppressed, so the life of the air conditioner is improved.

1 is a schematic configuration diagram of an air conditioner 1 of an embodiment; FIG. 2 is a vertical cross-sectional view of a compressor 21; FIG. FIG. 3 is a cross-sectional view of the compression mechanism 15 taken along line AA in FIG. 2; 8 is an external view of a cylinder 84; FIG. FIG. 4 is a cross-sectional view showing the configuration of an injection valve 93 in a first state; FIG. 4 is a cross-sectional view showing the configuration of an injection valve 93 in a second state; 4 is a plan view of the valve body 94 when viewed along the first direction D1. FIG. Fig. 11 is a plan view of the valve guard 95 when viewed along the first direction D1 from the side of the cylinder inner peripheral surface 86c; 4 is a cross-sectional view of the compression mechanism 15 when the piston 81 is positioned at top dead center; FIG. 4 is a cross-sectional view of the compression mechanism 15 when the piston 81 closes the suction hole 84b; FIG. 8 is a cross-sectional view of the compression mechanism 15 when the piston 81 blocks the injection passage 84g; FIG. It is a sectional view of compression mechanism 15 in the 1st modification.

An air conditioner 1 including a compressor 21 according to an embodiment of the present disclosure will be described with reference to the drawings.

(1) Air Conditioner (1-1) Overall Configuration As shown in FIG. 1, an air conditioner 1 is capable of cooling and heating a room such as a building by performing a vapor compression refrigeration cycle. It is a possible device. The air conditioner 1 mainly includes an outdoor unit 2 , an indoor unit 3 , a liquid refrigerant communication pipe 4 and a gas refrigerant communication pipe 5 . The liquid refrigerant communication pipe 4 and the gas refrigerant communication pipe 5 connect the outdoor unit 2 and the indoor unit 3 . The vapor compression refrigerant circuit 6 of the air conditioner 1 is configured by connecting the outdoor unit 2 and the indoor unit 3 via the liquid refrigerant communication pipe 4 and the gas refrigerant communication pipe 5 .

(1-2) Detailed Configuration (1-2-1) Indoor Unit The indoor unit 3 is installed indoors (a living room, a space above the ceiling, etc.) and constitutes a part of the refrigerant circuit 6 . The indoor unit 3 mainly has an indoor heat exchanger 31 . The indoor heat exchanger 31 functions as a refrigerant heat absorber (evaporator) to cool indoor air during cooling operation, and functions as a refrigerant radiator (condenser) to heat indoor air during heating operation. The liquid side of the indoor heat exchanger 31 is connected to the liquid refrigerant communication pipe 4 . The gas side of the indoor heat exchanger 31 is connected to the gas refrigerant communication pipe 5 .

(1-2-2) Outdoor Unit The outdoor unit 2 is installed outdoors (on the roof of the building, near the wall of the building, etc.) and forms part of the refrigerant circuit 6 . The outdoor unit 2 mainly includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor expansion valve 24, an accumulator 25, a liquid closing valve 26, a gas closing valve 27, and an economizer heat. It has an exchange 28 and a control unit 29 .

The compressor 21 compresses the low-pressure gas refrigerant in the compression chamber 40 into high-pressure gas refrigerant. The compressor 21 is driven by a compressor motor. Compressor 21 is a rotary compressor. In the compressor 21, intermediate injection is performed in which part of the refrigerant flowing from the outdoor heat exchanger 23 toward the outdoor expansion valve 24 is supplied to the compression chamber 40 compressing the refrigerant.

The four-way switching valve 22 switches the connection state of the internal piping of the outdoor unit 2 . When the air conditioner 1 performs cooling operation, the four-way switching valve 22 realizes the connection state indicated by the dashed line in FIG. When the air conditioner 1 performs heating operation, the four-way switching valve 22 realizes the connection state indicated by the solid line in FIG.

The outdoor heat exchanger 23 exchanges heat between the refrigerant circulating in the refrigerant circuit 6 and the outdoor air. The outdoor heat exchanger 23 has a refrigerant channel through which refrigerant flows, and heat transfer fins in contact with outdoor air. The outdoor heat exchanger 23 functions as a refrigerant radiator (condenser) during cooling operation, and functions as a refrigerant heat absorber (evaporator) during heating operation.

The outdoor expansion valve 24 is an electrically operated valve or an electromagnetic valve whose opening degree can be adjusted. The outdoor expansion valve 24 reduces the pressure of the refrigerant flowing through the internal piping of the outdoor unit 2 . The outdoor expansion valve 24 controls the flow rate of refrigerant flowing through the internal piping of the outdoor unit 2 .

The accumulator 25 is installed in the piping on the suction side of the compressor 21 . The accumulator 25 separates the gas-liquid mixed refrigerant flowing through the refrigerant circuit 6 into gas refrigerant and liquid refrigerant, and stores the liquid refrigerant. Gas refrigerant separated by the accumulator 25 is sent to the suction port of the compressor 21 .

The liquid shutoff valve 26 and the gas shutoff valve 27 are valves capable of shutting off the refrigerant flow path. The liquid closing valve 26 is arranged between the indoor heat exchanger 31 and the outdoor expansion valve 24 . A gas shutoff valve 27 is arranged between the indoor heat exchanger 31 and the four-way switching valve 22 . The liquid shutoff valve 26 and the gas shutoff valve 27 are opened and closed by an operator, for example, when installing the air conditioner 1 or the like.

The economizer heat exchanger 28 is arranged between the outdoor heat exchanger 23 and the outdoor expansion valve 24 . The economizer heat exchanger 28 exchanges heat between the refrigerant flowing from the outdoor heat exchanger 23 toward the outdoor expansion valve 24 and the refrigerant flowing through the economizer pipe 90 . The economizer pipe 90 is a pipe branched from between the economizer heat exchanger 28 and the outdoor expansion valve 24 in the refrigerant circuit 6 . An economizer valve 91 is attached to the economizer pipe 90 . Refrigerant flowing through economizer pipe 90 is decompressed by economizer valve 91 before being heat-exchanged by economizer heat exchanger 28 .

The control unit 29 is a computer that controls the components of the outdoor unit 2 . The control unit 29 mainly includes an arithmetic device and a storage device. A computing device is, for example, a CPU or a GPU. The arithmetic device reads a program stored in the storage device and performs predetermined arithmetic processing according to the program. The computing device writes computation results to a storage device and reads information stored in the storage device according to a program.

(1-2-3) Refrigerant Connection Pipe The liquid refrigerant communication pipe 4 and the gas refrigerant communication pipe 5 are constructed on site when the air conditioner 1 including the refrigerant circuit 6 is installed in a building or the like. Refrigerant piping. The length and diameter of the liquid refrigerant communication pipe 4 and the gas refrigerant communication pipe 5 are determined according to installation conditions such as the installation location of the air conditioner 1 and the combination of the outdoor unit 2 and the indoor unit 3 . The refrigerant flowing through the liquid refrigerant communication pipe 4 may be liquid or may be gas-liquid two-phase.

(1-3) Operation The operation of the air conditioner 1 during cooling operation and heating operation will be described with reference to FIG.

(1-3-1) Heating Operation When the air conditioner 1 performs heating operation, the four-way switching valve 22 is switched to the state indicated by the solid line in FIG. In the refrigerant circuit 6, the low-pressure gas refrigerant of the refrigerating cycle is sucked into the compressor 21, compressed to a high pressure of the refrigerating cycle, and then discharged. A high-pressure gas refrigerant discharged from the compressor 21 is sent to the indoor heat exchanger 31 through the four-way switching valve 22 , the gas shut-off valve 27 and the gas refrigerant communication pipe 5 . The high-pressure gas refrigerant sent to the indoor heat exchanger 31 exchanges heat with the indoor air in the indoor heat exchanger 31 and is condensed to become a high-pressure liquid refrigerant. This heats the indoor air. The liquid refrigerant condensed in the indoor heat exchanger 31 is sent to the outdoor expansion valve 24 through the liquid refrigerant communication pipe 4 and the liquid closing valve 26 . The refrigerant sent to the outdoor expansion valve 24 is decompressed by the outdoor expansion valve 24 to the low pressure of the refrigeration cycle. The low-pressure refrigerant decompressed by the outdoor expansion valve 24 is sent to the outdoor heat exchanger 23 . The low-pressure refrigerant sent to the outdoor heat exchanger 23 exchanges heat with the outdoor air in the outdoor heat exchanger 23 and evaporates to become a low-pressure gas refrigerant. The low-pressure refrigerant evaporated in the outdoor heat exchanger 23 is sucked into the compressor 21 again through the four-way switching valve 22 and the accumulator 25 .

(1-3-2) Cooling Operation When the air conditioner 1 performs cooling operation, the four-way switching valve 22 is switched to the state indicated by the dashed lines in FIG. In the refrigerant circuit 6, the low-pressure gas refrigerant of the refrigerating cycle is sucked into the compressor 21, compressed to a high pressure of the refrigerating cycle, and then discharged. A high-pressure gas refrigerant discharged from the compressor 21 is sent to the outdoor heat exchanger 23 through the four-way switching valve 22 . The high-pressure gas refrigerant sent to the outdoor heat exchanger 23 exchanges heat with the outdoor air in the outdoor heat exchanger 23 and is condensed to become a high-pressure liquid refrigerant. The liquid refrigerant condensed in the outdoor heat exchanger 23 is depressurized to the low pressure of the refrigeration cycle by the outdoor expansion valve 24 . The low-pressure refrigerant decompressed by the outdoor expansion valve 24 is sent to the indoor heat exchanger 31 through the liquid closing valve 26 and the liquid refrigerant connecting pipe 4 . The refrigerant sent to the indoor heat exchanger 31 exchanges heat with the room air in the indoor heat exchanger 31 and evaporates to become a low-pressure gas refrigerant. This cools the indoor air. The gas refrigerant evaporated in the indoor heat exchanger 31 is sucked into the compressor 21 again through the gas refrigerant communication pipe 5 , the gas shutoff valve 27 , the four-way switching valve 22 and the accumulator 25 .

(2) Compressor (2-1) Overall Configuration As shown in FIG. , a discharge pipe 20 , an injection pipe 92 and an injection valve 93 .

(2-1-1) Casing The casing 10 is composed of a cylindrical body 11 , a bowl-shaped top 12 and a bowl-shaped bottom 13 . The top portion 12 is airtightly connected to the upper end portion of the body portion 11 . The bottom portion 13 is airtightly connected to the lower end portion of the body portion 11 .

The casing 10 is made of a rigid member that is resistant to deformation and breakage due to changes in pressure and temperature in the internal and external spaces of the casing 10 . The casing 10 is installed so that the cylindrical axial direction of the trunk|drum 11 may follow a vertical direction. A lower portion of the internal space of the casing 10 is an oil reservoir 10a in which lubricating oil is reserved. The lubricating oil is refrigerating machine oil used to improve the lubricating properties of sliding parts inside the casing 10 .

The casing 10 mainly houses the compression mechanism 15, the drive motor 16, and the crankshaft 17. Compression mechanism 15 is connected to drive motor 16 via crankshaft 17 . The suction pipe 19 , the discharge pipe 20 and the injection pipe 92 are airtightly connected to the casing 10 so as to pass through the casing 10 .

(2-1-2) Compression Mechanism As shown in FIGS. 2 and 3, the compression mechanism 15 is mainly composed of a front head 83, a cylinder 84, a rear head 85, a piston 81, and a bush 82. be. The front head 83, cylinder 84 and rear head 85 are integrally fastened with bolts or the like. A space above the compression mechanism 15 is a high-pressure space HS into which refrigerant compressed by the compression mechanism 15 is discharged.

The compression mechanism 15 is immersed in lubricating oil stored in the oil storage portion 10a. The lubricating oil in the oil reservoir 10a is supplied to the sliding portion inside the compression mechanism 15 by differential pressure or the like. Next, each component of the compression mechanism 15 will be described.

(2-1-2-1) Cylinder As shown in FIG. 4, the cylinder 84 mainly includes a cylinder hole 84a, a suction hole 84b, a discharge cutout 84c, a bush accommodation hole 84d, and a vane accommodation hole 84e. and an injection passage 84g. Cylinder 84 is positioned between front head 83 and rear head 85 . A first cylinder end face 86 a , which is the upper end face of the cylinder 84 , contacts the lower face of the front head 83 . A second cylinder end face 86 b , which is the lower end face of the cylinder 84 , contacts the upper surface of the rear head 85 .

The cylinder hole 84a is a columnar hole penetrating the cylinder 84 in the vertical direction from the first cylinder end face 86a toward the second cylinder end face 86b. The cylinder hole 84 a is a space surrounded by a cylinder inner peripheral surface 86 c that is the inner peripheral surface of the cylinder 84 . The cylinder hole 84 a accommodates the eccentric shaft portion 17 a of the crankshaft 17 and the piston 81 .

The suction hole 84b is a hole penetrating along the radial direction of the cylinder 84 from the cylinder outer peripheral surface 86d, which is the outer peripheral surface of the cylinder 84, toward the cylinder inner peripheral surface 86c.

The discharge cutout 84c is a space formed without penetrating the cylinder 84 in the vertical direction by cutting out a part of the cylinder inner peripheral surface 86c. The discharge notch 84c is formed on the side of the first cylinder end face 86a.

The bush accommodation hole 84d is a hole that penetrates the cylinder 84 in the vertical direction and is arranged between the suction hole 84b and the discharge notch 84c when the cylinder 84 is viewed along the vertical direction. A portion of the vane 81b and the bush 82 are accommodated in the bush accommodation hole 84d.

The vane accommodation hole 84e is a hole that penetrates the cylinder 84 in the vertical direction and communicates with the bush accommodation hole 84d. The vane accommodation hole 84e accommodates a portion of the vane 81b.

The injection passage 84g is a hole penetrating along the radial direction of the cylinder 84 from the cylinder outer peripheral surface 86d toward the cylinder inner peripheral surface 86c. As shown in FIG. 3, when the cylinder 84 is viewed along the vertical direction, the bush accommodation hole 84d is arranged between the suction hole 84b and the injection passage 84g. An injection valve 93 is arranged in the injection passage 84g. The injection passage 84g communicates with the injection pipe 92 on the side of the cylinder outer peripheral surface 86d, and communicates with the compression chamber 40 on the side of the cylinder inner peripheral surface 86c.

(2-1-2-2) Piston The piston 81 is a substantially cylindrical member that is inserted into the cylinder hole 84 a of the cylinder 84 . An upper end surface of the piston 81 contacts the lower surface of the front head 83 . A lower end surface of the piston 81 contacts the upper surface of the rear head 85 .

The piston 81 is inserted into the cylinder hole 84a of the cylinder 84 while being fitted on the eccentric shaft portion 17a of the crankshaft 17. As shown in FIG. As a result, the piston 81 is eccentrically rotated by the axial rotation of the crankshaft 17 and performs revolving motion around the rotation axis 17g of the crankshaft 17 . The piston 81 revolves clockwise when the compression mechanism 15 is viewed from above.

The vane 81b is accommodated in the bush accommodation hole 84d and the vane accommodation hole 84e of the cylinder 84. The vane 81 b is formed integrally with the piston 81 . The vane 81b extends along the radial direction of the piston 81 so as to protrude radially outward of the piston 81 . As the piston 81 revolves, the vane 81b advances and retreats along its longitudinal direction while swinging. At this time, the bush 82 supports the vane 81b while rotating in the bush accommodation hole 84d.

The compression mechanism 15 has a compression chamber 40 that is a space surrounded by a cylinder 84, a piston 81, vanes 81b, a front head 83, and a rear head 85. The compression chamber 40 is a part of the cylinder hole 84a, and is a space in which the refrigerant is compressed as the volume changes as the piston 81 revolves. Lubricating oil in the oil reservoir 10 a is supplied to the compression chamber 40 .

The compression chamber 40 is divided by the piston 81 and the vane 81b into a low pressure chamber 40a communicating with the suction hole 84b and a high pressure chamber 40b communicating with the discharge cutout 84c and the injection passage 84g. In FIG. 3 , the low pressure chamber 40 a and the high pressure chamber 40 b are areas surrounded by a cylinder inner peripheral surface 86 c and a piston outer peripheral surface 81 c that is the outer peripheral surface of the piston 81 . The volumes of the low-pressure chamber 40 a and the high-pressure chamber 40 b change according to the position of the piston 81 .

(2-1-2-3) Bush The bush 82 is a pair of substantially semi-cylindrical members. The bush 82 is accommodated in the bush accommodation hole 84d of the cylinder 84 so as to sandwich the vane 81b. Bushing 82 is slidable with cylinder 84 .

(2-1-2-4) Front Head The front head 83 is a member that covers the first cylinder end surface 86 a of the cylinder 84 . The front head 83 is fastened to the casing 10 with bolts or the like. The front head 83 has an upper bearing portion 23 a for supporting the crankshaft 17 .

The front head 83 has a discharge port 23b. The discharge port 23b is a cylindrical hole penetrating the front head 83 in the vertical direction. The discharge port 23b communicates with the discharge notch 84c and the compression chamber 40 (high pressure chamber 40b) on the vertically lower side. The discharge port 23b communicates with the high-pressure space HS on the upper side in the vertical direction. The discharge port 23b is a channel for sending the refrigerant compressed by the compression mechanism 15 from the high pressure chamber 40b to the high pressure space HS.

A discharge valve 23c is attached to the upper surface of the front head 83 to block the discharge port 23b. The discharge valve 23c is a valve for preventing reverse flow of refrigerant from the high-pressure space HS to the high-pressure chamber 40b. The discharge valve 23c is lifted upward by the pressure of the refrigerant inside the discharge port 23b. As a result, the discharge port 23b is opened, and the discharge port 23b communicates with the high pressure space HS.

(2-1-2-5) Rear Head The rear head 85 is a member that covers the second cylinder end face 86b of the cylinder 84. As shown in FIG. Rear head 85 has a lower bearing portion 25 a for supporting crankshaft 17 . A cylinder hole 84 a of the cylinder 84 is closed by a front head 83 and a rear head 85 .

(2-1-3) Drive Motor The drive motor 16 is a brushless DC motor housed inside the casing 10 and arranged above the compression mechanism 15 . The drive motor 16 is mainly composed of a stator 51 fixed to the inner wall surface of the casing 10 and a rotor 52 rotatably accommodated inside the stator 51 . An air gap is provided between the stator 51 and the rotor 52 .

The stator 51 has a stator core 61 and a pair of insulators 62 attached to both vertical end surfaces of the stator core 61 . Stator core 61 has a cylindrical portion and a plurality of teeth (not shown) protruding radially inward from an inner peripheral surface of the cylindrical portion. Conducting wires are wound around the teeth of the stator core 61 together with a pair of insulators 62 . Thereby, a coil 72 a is formed on each tooth of the stator core 61 .

The outer surface of the stator 51 is provided with a plurality of core cut portions (not shown) cut out from the upper end surface to the lower end surface of the stator 51 at predetermined intervals in the circumferential direction. The core cut forms a motor cooling passage extending vertically between the body 11 and the stator 51 .

The rotor 52 has a rotor core 52a composed of a plurality of vertically stacked metal plates, and a plurality of magnets 52b embedded in the rotor core 52a. The magnets 52b are arranged at regular intervals along the circumferential direction of the rotor core 52a. The rotor 52 is connected to the crankshaft 17 that vertically extends through its center of rotation. Rotor 52 is connected to compression mechanism 15 via crankshaft 17 .

(2-1-4) Crankshaft The crankshaft 17 is accommodated inside the casing 10, and is arranged so that its axial direction is along the vertical direction. Crankshaft 17 is connected to rotor 52 of drive motor 16 and piston 81 of compression mechanism 15 . The crankshaft 17 has an eccentric shaft portion 17a. The eccentric shaft portion 17a is connected to the piston 81 inserted into the cylinder hole 84a of the cylinder 84 . The upper end of crankshaft 17 is connected to rotor 52 of drive motor 16 . The crankshaft 17 is supported by the upper bearing portion 23 a of the front head 83 and the lower bearing portion 25 a of the rear head 85 . The crankshaft 17 rotates around a rotation axis 17g.

(2-1-5) Suction Pipe The suction pipe 19 is a pipe passing through the body portion 11 of the casing 10 . The end of the suction pipe 19 inside the casing 10 is fitted into the suction hole 84 b of the cylinder 84 . The end of the intake pipe 19 outside the casing 10 is connected to the refrigerant circuit 6 . The suction pipe 19 supplies refrigerant from the refrigerant circuit 6 to the compression mechanism 15 .

(2-1-6) Discharge Pipe The discharge pipe 20 is a pipe passing through the top portion 12 of the casing 10 . The end of the discharge pipe 20 inside the casing 10 is located in the space above the drive motor 16 . The end of the discharge pipe 20 outside the casing 10 is connected to the refrigerant circuit 6 . The discharge pipe 20 supplies the refrigerant compressed by the compression mechanism 15 to the refrigerant circuit 6 .

(2-1-7) Injection Pipe The injection pipe 92 is a pipe passing through the body portion 11 of the casing 10 . An end of the injection pipe 92 inside the casing 10 is connected to an injection valve 93 arranged inside the injection passage 84 g of the cylinder 84 . The end of injection pipe 92 outside casing 10 is connected to economizer pipe 90 . The injection pipe 92 supplies the refrigerant in the economizer pipe 90 to the injection passage 84g.

(2-2) Detailed Configuration In the compressor 21, intermediate-pressure refrigerant flowing through the refrigerant circuit 6 is supplied to the injection passage 84g via the economizer pipe 90 and the injection pipe 92. As shown in FIG. The intermediate pressure is the pressure between the pressure of the low-pressure refrigerant sucked into the compressor 21 and the pressure of the high-pressure refrigerant discharged from the compressor 21 . In order to improve the performance of the air conditioner 1, it is preferable to supply a sufficient amount of intermediate pressure refrigerant from the injection passage 84g to the compression chamber 40 (high pressure chamber 40b). However, if the refrigerant flows backward from the compression chamber 40 (high-pressure chamber 40b) toward the injection passage 84g, the performance of the air conditioner 1 may decrease.

An injection valve 93 is arranged in the injection passage 84g. When the pressure in the compression chamber 40 is lower than the injection pressure, which is the pressure of the medium-pressure refrigerant in the injection pipe 92, the injection valve 93 opens. The injection valve 93 closes when the pressure in the compression chamber 40 is equal to or higher than the injection pressure. When the injection valve 93 is open, the medium-pressure refrigerant is allowed to flow from the injection passage 84g toward the compression chamber 40 . When the injection valve 93 is closed, the refrigerant in the compression chamber 40 is restrained from flowing from the compression chamber 40 toward the injection passage 84g. As a result, the injection valve 93 prevents the refrigerant from flowing back from the compression chamber 40 to the injection passage 84g.

As shown in FIGS. 5 and 6, the injection valve 93 mainly has a valve body 94, a valve guard 95, and a valve seat 96. The valve guard 95 and the valve seat 96 are fixed to the cylinder 84 by being press-fitted into the injection passage 84g. The valve guard 95 and the valve seat 96 are arranged apart from each other along the first direction D1 in which the injection passage 84g extends. A space between the valve guard 95 and the valve seat 96 is a first space 97 arranged so that the valve body 94 can move in the first direction D1. The valve guard 95 is arranged closer to the injection pipe 92 than the valve main body 94 . The valve seat 96 is arranged closer to the compression chamber 40 than the valve body 94 .

The injection passage 84g is a circular hole with different inner diameters along the first direction D1. The injection passage 84g has the largest inner diameter at the end on the cylinder outer peripheral surface 86d side and the smallest inner diameter at the end on the cylinder inner peripheral surface 86c side. Specifically, the inner diameter of the injection passage 84g increases from the cylinder inner peripheral surface 86c side toward the cylinder outer peripheral surface 86d side.

The valve body 94 is a circular flat plate. The valve body 94 is made of spring steel such as GIN6 (hardened stainless steel manufactured by Hitachi Metals, Ltd.). As shown in FIG. 7, the central portion of the valve body 94 is formed with a circular central hole 94a. The valve body 94 has an annular peripheral edge 94b positioned around the central bore 94a. In FIG. 7, the peripheral portion 94b is shown as a hatched area.

The valve guard 95 is press-fitted on the cylinder outer peripheral surface 86d side of the injection passage 84g. The valve guard 95 has a shape with an outer diameter that varies along the first direction D1. A portion of the valve guard 95 protrudes outward from the cylinder outer peripheral surface 86d. An injection pipe 92 is inserted into the valve guard 95 from the cylinder outer peripheral surface 86d side. The injection pipe 92 is fixed to the valve guard 95 . As shown in FIGS. 5 and 6, an O-ring 92a attached to the injection pipe 92 separates the injection passage 84g from the high pressure space HS.

The valve guard 95 has a first hole 95a and a closing portion 95b. The first hole 95a penetrates the valve guard 95 along the first direction D1. As shown in FIG. 8, when the valve guard 95 is viewed along the first direction D1 from the cylinder inner peripheral surface 86c side, the closing portion 95b is a circular area positioned in the center of the valve guard 95, and has a plurality of openings. The first hole 95a of is formed around the closing portion 95b. In FIG. 8, the closure 95b is shown as a hatched area. In the valve guard 95 shown in FIG. 8, twelve first holes 95a are arranged in a circle. The outer diameter of the closing portion 95b is larger than the diameter of the central hole 94a of the valve body 94 . The diameter of the first hole 95a is smaller than the width of the peripheral portion 94b of the valve body 94 (the radial dimension of the valve body 94).

The valve guard 95 restricts movement of the valve body 94 toward the injection pipe 92 side. In other words, when the valve body 94 moves toward the injection pipe 92 in the first direction D<b>1 , it can move until it hits the valve guard 95 . When the valve body 94 is in contact with the valve guard 95 , the first hole 95 a of the valve guard 95 is closed by the peripheral edge portion 94 b of the valve body 94 . At this time, the central hole 94 a of the valve body 94 is closed by the closing portion 95 b of the valve guard 95 . When the valve body 94 is separated from the valve guard 95 , the first hole 95 a of the valve guard 95 is not blocked by the peripheral edge portion 94 b of the valve body 94 . At this time, the central hole 94a of the valve body 94 is not blocked by the closing portion 95b of the valve guard 95. As shown in FIG.

Thus, the first hole 95a of the valve guard 95 is opened and closed by the valve body 94. Specifically, when the valve body 94 is in contact with the valve guard 95, the central hole 94a of the valve body 94 and the first hole 95a of the valve guard 95 are closed, so the injection valve 93 is closed. in a state. On the other hand, when the valve main body 94 is separated from the valve guard 95, the central hole 94a of the valve main body 94 and the first hole 95a of the valve guard 95 are not blocked, so the injection valve 93 is open. It is in.

The valve seat 96 is press-fitted on the cylinder inner peripheral surface 86c side of the injection passage 84g. The valve seat 96 has a shape with substantially the same outer diameter along the first direction D1. The valve seat 96 has a second hole 96a. The second hole 96a penetrates the valve seat 96 along the first direction D1. The diameter of the second hole 96 a is substantially the same as the diameter of the central hole 94 a of the valve body 94 . The second hole 96a always communicates with the compression chamber 40 via the injection passage 84g.

The valve seat 96 restricts movement of the valve body 94 toward the compression chamber 40 side. In other words, the valve body 94 is movable until it hits the valve seat 96 when moving in the first direction D1 toward the compression chamber 40 . When the valve body 94 is in contact with the valve seat 96 , the central hole 94 a of the valve body 94 communicates with the second hole 96 a of the valve seat 96 . Since the valve body 94 is separated from the valve guard 95 when the valve body 94 is in contact with the valve seat 96, the injection valve 93 is in an open state.

When shifting from the first state (FIG. 5) in which the valve body 94 contacts the valve guard 95 and closes the first hole 95a to the second state (FIG. 6) in which the valve body 94 separates from the valve guard 95 and contacts the valve seat 96, The valve body 94 moves along the first direction D1.

In the first state, as shown in FIG. 5, the central hole 94a of the valve body 94 and the first hole 95a of the valve guard 95 are closed, so the central hole 94a communicates with the first hole 95a. not. Therefore, the refrigerant in the injection pipe 92 cannot flow into the compression chamber 40 through the first hole 95a and the central hole 94a. On the other hand, in the second state, as shown in FIG. 6, the central hole 94a and the first hole 95a are not blocked, so the central hole 94a communicates with the first hole 95a through the first space 97. ing. Therefore, the refrigerant in the injection pipe 92 can flow into the compression chamber 40 through the first hole 95a and the central hole 94a.

Hereinafter, as shown in FIGS. 5 and 6, the amount of movement of the valve body 94 in the first direction D1 when shifting from the first state to the second state is defined as a first distance L, and the valve body 94 is defined as a first dimension t in the first direction D1.

The first distance L and the first dimension t satisfy the following relational expression (I).
L<t (I)

As shown in FIGS. 5 and 6, when the dimension of the first space 97 in the first direction D1 is defined as the second dimension s, the following relational expressions (II) and (III) are satisfied.
L<t<s (II)
s=L+t (III)

Preferably, the first distance L and the first dimension t satisfy the following relational expression (IV).
0.2 mm≦L<t≦1.8 mm (IV)

More preferably, the first distance L and the first dimension t satisfy the following relational expression (V).
0.6mm≦L<t≦1.0mm (V)

More preferably, the first distance L and the first dimension t satisfy the following relational expression (VI).
1.2≤t/L≤2.0 (VI)

Further, the area of the valve body 94 when viewed along the first direction D1 is defined as the first area S1, and the area of the first hole 95a of the valve guard 95 when viewed along the first direction D1 is defined as the first area S1. 2 area is defined as S2. The first area S1 is the area of the peripheral portion 94b and does not include the area of the central hole 94a. The second area S2 is the total area of all the first holes 95a of the valve guard 95. As shown in FIG. The area of the central hole 94a and the first hole 95a is the area when viewed along the first direction D1.

The first area S1 and the second area S2 satisfy the following relational expression (VII).
4.1≦S1/S2≦4.9 (VII)

Relational expression (VII) is equivalent to the following relational expression (VIII).
4.1≦(i ² −j ² )/(n×k ² )≦4.9 (VIII)

here,
i: outer diameter of valve body 94 j: diameter of central hole 94a of valve body 94 n: number of first holes 95a of valve guard 95 k: diameter of first hole 95a of valve guard 95 (Figs. 8). In FIG. 8, n is twelve.

The first area S1 and the second area S2 can be represented by the following relational expressions (IX) and (X) using variables i, j, n, and k.
S1=(i/2) ² ×π−(j/2) ² ×π (IX)
S2=n×(k/2) ² ×π(X)

By substituting the relational expressions (IX) and (X) into the relational expression (VII), the relational expression (VIII) is derived.

(2-3) Operation of Compressor When the drive motor 16 is started, the eccentric shaft portion 17a of the crankshaft 17 rotates eccentrically around the rotary shaft 17g of the crankshaft 17. As shown in FIG. Thereby, the piston 81 connected to the eccentric shaft portion 17 a revolves within the cylinder hole 84 a of the cylinder 84 . While the piston 81 is revolving, the piston outer peripheral surface 81c is in contact with the cylinder inner peripheral surface 86c. Due to the revolution of the piston 81, the vane 81b advances and retreats while being sandwiched between the bushes 82 on both sides thereof.

As the piston 81 revolves, the compression chamber 40 (low pressure chamber 40a) communicating with the suction hole 84b gradually increases in volume. At this time, low-pressure refrigerant flows into the low-pressure chamber 40 a from the outside of the casing 10 via the suction pipe 19 . As the piston 81 revolves, the low-pressure chamber 40a becomes a high-pressure chamber 40b that communicates with the discharge notch 84c. The high-pressure chamber 40b gradually decreases in volume and disappears. . As a result, the low-pressure refrigerant flowing into the low-pressure chamber 40a from the suction pipe 19 through the suction hole 84b is compressed in the compression chamber 40 (high-pressure chamber 40b). While the refrigerant is compressed in the compression chamber 40, the vane 81b is held between the pair of bushes so as to be able to move forward and backward.

The high-pressure refrigerant compressed in the high-pressure chamber 40b is discharged into the high-pressure space HS via the discharge notch 84c and the discharge port 23b. The refrigerant discharged into the high-pressure space HS flows upward through the motor cooling passage of the drive motor 16 and is then discharged from the discharge pipe 20 to the outside of the casing 10 .

While the refrigerant is being compressed in the compression chamber 40, intermediate injection is performed in which intermediate pressure refrigerant flowing through the refrigerant circuit 6 is supplied to the high pressure chamber 40b. Intermediate injection is performed by supplying intermediate-pressure refrigerant from the injection passage 84g to the high-pressure chamber 40b while the injection valve 93 is open. Intermediate injection is performed when the pressure in the compression chamber 40 (high pressure chamber 40b) is lower than the injection pressure, and is not performed when the pressure in the compression chamber 40 (high pressure chamber 40b) is equal to or higher than the injection pressure.

As described below, the injection valve 93 is repeatedly opened and closed while the piston 81 is revolving. As shown in FIG. 9, the entire vane 81b is supported by the pair of bushes 82 when the piston 81 is at the top dead center. At this time, the compression chamber 40 is not divided into the low pressure chamber 40a and the high pressure chamber 40b by the piston 81, and the compression chamber 40 communicates with both the suction hole 84b and the injection passage 84g. Therefore, the compression chamber 40 is filled with low-pressure refrigerant flowing from the suction hole 84b. Since the pressure in the compression chamber 40 is lower than the injection pressure, the injection pressure causes the valve body 94 to move toward and strike the valve seat 96 . As a result, the injection valve 93 opens.

When the piston 81 revolves from the state shown in FIG. 9, the piston 81 closes the opening of the suction hole 84b in the cylinder inner peripheral surface 86c as shown in FIG. At this time, the compression chamber 40 is divided into a low pressure chamber 40a and a high pressure chamber 40b by the piston 81, and the high pressure chamber 40b communicates with the injection passage 84g. After that, when the piston 81 revolves further and the pressure in the high pressure chamber 40b rises, the pressure in the high pressure chamber 40b becomes equal to or higher than the injection pressure. As a result, the valve main body 94 is moved toward the valve guard 95 by the pressure in the high pressure chamber 40b and comes into contact with the valve guard 95 . As a result, the injection valve 93 is closed.

Next, when the piston 81 revolves further, as shown in FIG. 11, the piston 81 closes the opening of the injection passage 84g in the cylinder inner peripheral surface 86c. At this time, the compression chamber 40 is divided into a low-pressure chamber 40a and a high-pressure chamber 40b by the piston 81, and the low-pressure chamber 40a communicates with the suction hole 84b. Therefore, the low-pressure chamber 40a is filled with low-pressure refrigerant flowing from the suction hole 84b. Thereafter, when the piston 81 revolves further and the low pressure chamber 40a communicates with the injection passage 84g, the pressure in the low pressure chamber 40a is lower than the injection pressure, so the injection pressure causes the valve body 94 to move toward the valve seat 96. It hits the valve seat 96 . As a result, the injection valve 93 opens. After that, when the piston 81 revolves further, the piston 81 is positioned at the top dead center as shown in FIG.

Therefore, while the piston 81 is revolving, the injection valve 93 opens and closes due to the pressure difference between the refrigerant in the compression chamber 40 and the intermediate pressure refrigerant in the injection pipe 92 . As a result, while the piston 81 is revolving, the compressor 21 transitions from the first state (FIG. 5) in which the injection valve 93 is closed to the second state (FIG. 6) in which the injection valve 93 is open. , the transition from the second state to the first state is repeated. Therefore, while the compressor 21 is compressing the refrigerant, the valve body 94 collides with the valve seat 96 each time the injection valve 93 opens, and collides with the valve guard 95 each time the injection valve 93 closes.

(3) Features (3-1)
While the compressor 21 is compressing the refrigerant, the valve body 94 repeatedly collides with the valve guard 95 and the valve seat 96 . In the case of a rotary compressor such as the compressor 21 , the injection valve 93 is opened by the pressure difference between the refrigerant in the compression chamber 40 and the intermediate pressure refrigerant in the injection pipe 92 as described above. The pressure of the refrigerant inside the suction hole 84 b communicating with the compression chamber 40 is the lowest in the refrigerant circuit 6 . Therefore, in the case of a rotary compressor, since the pressure difference that is the driving force for opening and closing the injection valve 93 is relatively large, the speed of the valve body 94 when it collides with the valve guard 95 and the valve seat 96 tends to increase. .

On the other hand, for example, in the case of a scroll compressor, the valve opens due to the pressure difference between the refrigerant with a pressure higher than the lowest pressure in the refrigerant circuit and the refrigerant with an intermediate pressure. Therefore, in the scroll type compressor, the pressure difference, which is the driving force for opening and closing the valve, tends to be smaller than in the rotary type compressor, so the speed of the valve body when opening and closing the valve is also small. The greater the speed of the valve body, the greater the impact load when the valve body collides with other members, so the valve body is more likely to be damaged. In addition, the higher the intermediate pressure, the greater the pressure difference, which is the driving force for opening and closing the valve, and the faster the valve body.

In the present embodiment, the amount of movement of the valve body 94 in the first direction D1 (first distance L) while the compressor 21 is compressing the refrigerant is the dimension of the valve body 94 in the first direction D1 (first dimension t). Since the upper limit of the first distance L is set, the speed of the valve body 94 is regulated, and the impact load of the valve body 94 when it hits the valve guard 95 and the valve seat 96 is reduced. In addition, since the lower limit value of the first dimension t is set, the thickness of the valve body 94 can be ensured to be equal to or greater than a predetermined value, and a drop in the fatigue strength of the valve body 94 can be suppressed. Furthermore, the larger the ratio t/L between the first dimension t and the first distance L, the more the valve body 94 is prevented from tilting with respect to the first direction D1 when the valve body 94 moves. As a result, when the valve body 94 comes into contact with the valve guard 95 and the valve seat 96, the local load applied to the valve body 94 is suppressed. Therefore, in the present embodiment, even if the pressure difference that is the driving force for opening and closing the injection valve 93 is relatively large, damage to the valve body 94 is suppressed, and the reliability of the compressor 21 is improved. Further, in a rotary compressor such as the compressor 21 of the present embodiment, a pressure difference that serves as a driving force for opening and closing a valve such as the injection valve 93 of the present embodiment is greater than that of a scroll compressor. Since it tends to be large, it is highly effective in suppressing damage to the valve and improving reliability.

(3-2)
In the compressor 21, the injection valve 93 is designed such that the first distance L and the first dimension t satisfy the above relationships (IV)-(VI). This effectively suppresses damage to the valve body 94 .

(3-3)
In the compressor 21, the valve body 94 and the valve guard 95 are designed so that the above relationships (VII) and (VIII) are satisfied. Thereby, the sealing performance of the injection valve 93 is appropriately ensured.

(3-4)
In the compressor 21, the valve body 94 is made of spring steel. This effectively suppresses damage to the valve body 94 .

(3-5)
In the scroll compressor described above, the movable scroll revolves around the fixed scroll, thereby reducing the volume of the compression chamber formed by the fixed scroll and the movable scroll, thereby compressing the refrigerant in the compression chamber. Generally, in scroll compressors, the movable scroll revolves at least twice with respect to the fixed scroll until the low-pressure refrigerant is compressed into high-pressure refrigerant. Therefore, when the scroll compressor is provided with a valve such as the injection valve 93, the valve opens and closes once every time the orbiting scroll makes at least two revolutions.

On the other hand, in a rotary compressor like the compressor 21 of this embodiment, the injection valve 93 opens and closes once each time the piston 81 revolves once. Therefore, rotary compressors tend to open and close valves such as the injection valve 93 more often than scroll compressors. Therefore, in a rotary compressor such as the compressor 21 of this embodiment, valves such as the injection valve 93 of this embodiment are more likely to be damaged than in a scroll compressor. The effect of suppressing and improving reliability is large.

(3-6)
The air conditioner 1 includes a compressor 21 . By suppressing damage to the valve body 94 of the compressor 21, the reliability of the air conditioner 1 is improved. Further, by increasing the amount of the intermediate-pressure refrigerant supplied to the compression chamber 40 by intermediate injection, the capacity of the air conditioner 1 can be improved.

(4) Modifications (4-1) First Modification In the embodiment, the compressor 21 is a rotary compressor. However, the injection valve 93 can also be applied to compressors other than rotary compressors. For example, the injection valve 93 can also be applied to scroll compressors.

Further, when the compressor 21 is a rotary compressor, the configuration of the compression mechanism 15 is not particularly limited. For example, compression mechanism 15 may have a configuration that does not have bush 82 . Specifically, the compression mechanism 15 may have a piston 81, a vane 81b, and a spring 87, as shown in FIG. Piston 81 and vane 81b are members separate from each other. The spring 87 is accommodated in a spring accommodation hole 84f penetrating the cylinder 84 in the vertical direction. A spring 87 presses the vane 81 b toward the piston 81 revolving within the cylinder hole 84 a of the cylinder 84 . The vane 81b partitions the compression chamber 40 into a low-pressure chamber 40a and a high-pressure chamber 40b while being in contact with the revolving piston 81 . While the refrigerant is compressed in the compression chamber 40, the vane 81b is held by the spring housing hole 84f so as to be able to advance and retreat.

(4-2) Second Modification The injection valve 93 may further have an elastic body arranged between the valve body 94 and the valve seat 96 . The elastic body is, for example, a spring. The elastic body is configured to press the valve body 94 against the valve guard 95 when the pressure in the compression chamber 40 exceeds a pressure lower than the injection pressure by a predetermined value.

In this modified example, chattering of the valve body 94 is suppressed by pressing the valve body 94 toward the valve guard 95 with an elastic body. Moreover, even when the pressure in the compression chamber 40 is slightly lower than the injection pressure, the refrigerant is prevented from flowing back from the compression chamber 40 to the injection passage 84g.

- Conclusion -
Although embodiments of the present disclosure have been described above, it will be appreciated that various changes in form and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the appended claims. .

Reference Signs List 1: Air conditioner 15: Compression mechanism 21: Compressor 40: Compression chamber 40a: Low pressure chamber (first chamber)
40b: high pressure chamber (second chamber)
81: Piston 81b: Vane 82: Pair of bushes 84g: Injection passage 92: Injection pipe 93: Injection valve 94: Valve body 95: Valve retainer 95a: First hole 96: Valve seat D1: First direction

JP 2016-17464 A

Claims

a compression mechanism (15) having a compression chamber (40) in which refrigerant is compressed;
an injection valve (93) arranged in an injection passage (84g) communicating with the compression chamber;
an injection pipe (92) for supplying coolant to the injection passage;
with
The injection valve is
a valve body (94) arranged movably along a first direction (D1);
a valve retainer (95) arranged closer to the injection pipe than the valve body and restricting movement of the valve body toward the injection pipe;
a valve seat (96) disposed closer to the compression chamber than the valve body and restricting movement of the valve body toward the compression chamber;
has
The valve guard is formed with a first hole (95a) that is opened and closed by the valve body,
The first direction of the valve body when transitioning from a first state in which the valve body abuts on the valve guard to block the first hole to a second state in which the valve body separates from the valve guard and abuts on the valve seat. is smaller than the first dimension, which is the dimension of the valve body in the first direction,
Compressor (21).
If the first distance is L and the first dimension is t, a relational expression of 0.2 mm ≤ L < t ≤ 1.8 mm is satisfied;
A compressor according to claim 1 .
When the area of the valve body when viewed along the first direction is S1 and the area of the first hole when viewed along the first direction is S2, 4.1≦S1/S2 satisfies the relation of ≦4.9,
A compressor according to claim 1 or 2.
wherein the valve body is made of spring steel;
A compressor according to any one of claims 1 to 3.
The compression mechanism has a piston (81) and a vane (81b) that is in contact with the piston and divides the compression chamber into a first chamber (40a) and a second chamber (40b),
The vane is held reciprocally while the refrigerant is compressed in the compression chamber,
A compressor according to any one of claims 1 to 4.
The compression mechanism has a vane (81b) that divides the compression chamber into a first chamber (40a) and a second chamber (40b), and a pair of bushes (82),
The vane is movably held between the pair of bushes while the refrigerant is compressed in the compression chamber,
A compressor according to any one of claims 1 to 4.
A compressor according to any one of claims 1 to 6,
An air conditioner (1).