JP2001194030A - Motor expansion valve for refrigerating system and refrigerating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable motor expansion valve for refrigeration system by preventing malfunction due to adhesion of sludge. SOLUTION: A body 130 is provided with refrigerant channels 121, 122, and a slide hole 120 intersecting the refrigerant channels 121, 122. A valve stem 123 is fitted slidably in the slide hole 120. The rotor 139 of a motor is provided around a part of the valve stem 123 projecting from the slide hole 120 to the side opposite to the refrigerant channels 121, 122. Threaded parts 125, 126 for converting the rotational motion of the rotor 139 about the axis into linear motion of the valve stem 123 in the axial direction are provided between the rotor 139 and the valve stem 123. Forward end part 113 of the valve stem 123 forms a pressure reducing part 137 for expanding refrigerant flowing through the refrigerant channels 121, 122. The distance 11 between the threaded parts 125, 126 and the pressure reducing part 137 is set at 5 mm or longer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-operated expansion valve for a refrigeration system which is inserted into a refrigerant circuit for expanding a refrigerant. The present invention also relates to a refrigeration system having such a motor-operated expansion valve in a refrigerant circuit.

[0002]

2. Description of the Related Art Generally, a refrigerating apparatus includes a compressor, a condenser,
The refrigerant is circulated through a refrigerant circuit provided with a decompression mechanism and an evaporator, and a refrigerating cycle is executed in which the heat absorbed on the low temperature side (evaporator) is transferred and discharged on the high temperature side (condenser).

As the pressure reducing mechanism, an electric expansion valve capable of controlling the flow rate of the refrigerant is often used. The electric expansion valve illustrated in FIG. 3 includes a main casing 130 composed of an upper casing 130a and a lower casing 130b joined at a joint 130c. Lower casing 13
0b, the first refrigerant flow path 12 which is on the vertical axis in the drawing and opens on the bottom side of the lower casing 130b.
1 and a second refrigerant flow path 1 that intersects the first refrigerant flow path 121 at a substantially right angle and opens on the side surface of the lower casing 130b.
22 are formed. And the first refrigerant flow path 12
1 is provided with a first joint pipe 131 communicating from the opening side of the bottom face, and the second refrigerant flow path 122 is provided with a second joint pipe 132 communicating with the opening side of the side face. It can be connected to the constituent refrigerant pipe.

On the other hand, a slide hole 120 is provided substantially coaxially with the first refrigerant flow passage 121, and the slide hole 120 supports a needle (valve rod) 123 so as to be slidable up and down. A magnet 128 is rotatably provided on the inner side surface of the upper casing 130a about the central axis of the needle 123, and a spacer 129 and a female screw 126 are integrally provided on the magnet 128. . The needle 123 is urged downward with respect to the spacer 129 by a spring 127, and its lower position is regulated by a stopper metal 123a. Further, a male screw indicated by reference numeral 125 in the same figure is configured such that an outer surface thereof is screwed with the female screw 126, while an inner surface thereof is configured to slidably support the needle 123 in a vertical direction. Is fixedly provided.

[0005] When the electric expansion valve is used, a coil (not shown) is arranged so as to surround the outer peripheral side of the upper casing 130a. A pulse motor using the coil and the magnet 128 as a driving source is configured.
The magnet 128, the spacer 129, and the female screw 126 provided integrally function as the rotor 139. Here, since the female screw 126 and the male screw 125 are screwed with each other, the rotor 139 moves up and down in the main body casing 130 with the rotation thereof. The needle 123 is connected to the spacer 1 forming the rotor 139.
Because the position of the rotor 29 is regulated by the spring 127 and the stopper 123 a, it is possible to move up and down with respect to the main body casing 130 in accordance with the pulse applied to the coil with the movement of the rotor 139. Become. The pin 13 provided at the upper part in the upper casing 130a
3, slide 134, guide 135 and mandrel 136,
The rotor 139 is provided for smooth rotation.

The first of the inner walls of the lower casing 130b
An annular valve seat 114 is formed at the boundary between the coolant channel 121 and the second coolant channel 122, while the valve seat 114 is provided at the tip of the needle 123 supported by the slide hole 120.
And a valve portion 113 which can be in close contact with the valve.

In this motor-operated expansion valve, the needle 123 moves up and down, so that the valve seat 114 and the valve portion 113 are moved.
The width of the gap 137 between the gap 137 changes, and the flow rate of the refrigerant passing through the gap 137 changes. Therefore, the refrigerant flowing between the first refrigerant flow channel 121 and the second refrigerant flow channel 122 can be expanded and the flow rate of the refrigerant can be adjusted. In such a refrigeration apparatus using the electric expansion valve, the flow rate of the refrigerant can be controlled according to the discharge pipe temperature and the like, and the efficiency (coefficient of performance) of the refrigeration cycle can be optimally controlled.

[0008]

In the past, generally, a chlorofluorocarbon-based refrigerant such as HCFC22 was used as a refrigerant,
Mineral oil (naphthenic) was used as the refrigerating machine oil. However, since chlorofluorocarbon-based refrigerants such as HCFC22 have been subject to chlorofluorocarbon regulation, HFC134a and other HFC134a containing hydrofluorocarbon as a main component have been used as substitute refrigerants.
A system refrigerant has been used. Further, as the refrigerating machine oil, synthetic solubility such as ether oil, ester oil, and carbonate oil has come to be used because mutual solubility with a refrigerant is one of the important characteristics.

However, since the HFC-based refrigerant does not contain chlorine atoms in its molecular structure, the lubrication performance of the compressor is reduced. In addition, HFC-based refrigerant has a strong polarity due to its structure,
Non-polar sludge and contaminants (cutting oil, rolled oil, pipe expansion oil, processing oil, assembly oil, cleaning agent, etc. remaining in the refrigerant circuit during the processing stage) are not dissolved and are easily precipitated in the condensed liquid refrigerant. . For this reason, there is a problem that deposits in the liquid refrigerant adhere to the inside of the electric expansion valve and cause clogging.

[0010] In addition, the above synthetic oil has a property of easily dissolving contaminants. Since some refrigerating machine oil is discharged from the compressor together with the discharged refrigerant, dissolved contaminants also flow through the refrigerant circuit. Therefore, when synthetic oil is used as the refrigerating machine oil, clogging easily occurs inside the electric expansion valve due to sludge or the like after the refrigerant has evaporated.

When the motor-operated expansion valve is clogged in this way, the motor-operated expansion valve malfunctions. As a result, problems such as an increase in high pressure, an increase in the discharge temperature of the compressor, and an insufficient refrigeration capacity occur in the refrigeration cycle. Eventually, the operation of the protection device leads to the stoppage of the device.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric expansion valve for a refrigeration system capable of preventing malfunction due to adhesion of sludge or the like and improving reliability. Another object of the present invention is to provide a refrigeration apparatus that includes a refrigerant circuit having such an electric expansion valve and that can improve reliability.

[0013]

SUMMARY OF THE INVENTION According to the present invention, an operation failure of an electric expansion valve in a refrigerant circuit using an HFC-based refrigerant is as follows.
Rather than clogging the gap between the tip of the needle and the valve seat, this is caused by a blockage in the thread provided between the rotor and the needle to convert the rotary motion of the rotor into a linear motion of the needle. Was created based on the discovery by the present inventor.

According to a first aspect of the present invention, there is provided an electric expansion valve for a refrigerating apparatus, wherein a main body is provided with a refrigerant flow path penetrating the main body and a slide hole intersecting the refrigerant flow path. A valve rod is slidably fitted in the slide hole, and a rotor for the motor is provided around a portion of the valve rod protruding from the slide hole to the side opposite to the refrigerant flow path. A screw is provided between the rod and the rod to convert the rotational movement of the rotor around the axis into a linear movement in the axial direction of the valve rod, and the refrigerant flowing through the refrigerant flow path is expanded by the tip of the valve rod. In a motor-operated expansion valve for a refrigeration system in which a pressure reducing portion is formed, a distance (l ₁ ) between the screw portion and the pressure reducing portion is set to 5 mm or more.

In the electric expansion valve for a refrigeration system according to the first aspect,
Is the distance (l ₁) Is 5mm
Torr or higher, so between the screw section and the decompression section
Distance (l₁) Is sufficiently secured. Therefore,
Clogging of the screw part due to adhesion of
As a result, malfunctions are less likely to occur and reliability is improved.

According to a second aspect of the present invention, there is provided an electric expansion valve for a refrigerating apparatus, wherein a main body is provided with a refrigerant flow path penetrating the main body, and a slide hole intersecting the refrigerant flow path, and a valve rod slides in the slide hole. A motor rotor is provided around a portion that is movably fitted and protrudes from the slide hole of the valve stem toward the side opposite to the refrigerant flow path, and the rotation is provided between the rotor and the valve stem. By providing a screw portion for converting the rotational motion about the axis of the valve into a linear motion in the axial direction of the valve stem, a pressure reducing portion for expanding the refrigerant flowing through the refrigerant flow path by the tip of the valve stem is provided. In the electric expansion valve for a refrigeration system, when the distance between the screw portion and the pressure reducing portion is l ₁ and the inner diameter of the refrigerant flow path is d ₁ , the following expression is satisfied: (l ₁ / d ₁ ) ≧ 0.7 It is characterized by being set.

In the electric expansion valve for a refrigeration system according to the present invention, when the distance between the screw portion and the pressure reducing portion is l _1, and the inside diameter of the refrigerant flow path is d ₁ , (l ₁ / d ₁ ) Since 0.7 is set, the distance (l ₁ ) between the screw portion and the pressure reducing portion is substantially sufficiently ensured. Therefore, clogging of the screw portion due to adhesion of sludge or the like is effectively prevented, malfunction is less likely to occur, and reliability is improved.

According to a third aspect of the present invention, there is provided an electric expansion valve for a refrigeration system, wherein a main body is provided with a refrigerant flow path penetrating the main body and a slide hole intersecting the refrigerant flow path, and a valve rod slides in the slide hole. A motor rotor is provided around a portion that is movably fitted and protrudes from the slide hole of the valve stem toward the side opposite to the refrigerant flow path, and the rotation is provided between the rotor and the valve stem. By providing a screw portion for converting the rotational motion about the axis of the valve into a linear motion in the axial direction of the valve stem, a pressure reducing portion for expanding the refrigerant flowing through the refrigerant flow path by the tip of the valve stem is provided. In the electric expansion valve for a refrigeration system, a distance (l ₂ ) between the screw portion and the tip of the valve stem is set to be 8 mm or more.

In the electric expansion valve for a refrigeration system according to the third aspect, the distance (l ₂ ) between the screw portion and the tip of the valve stem is set to 8 mm or more. Is sufficiently ensured (l ₂ ). Therefore, clogging of the screw portion due to adhesion of sludge or the like is effectively prevented, malfunction is less likely to occur, and reliability is improved.

According to a fourth aspect of the present invention, in the refrigerant circuit including a compressor, a condenser, an expansion means, and an evaporator, a single refrigerant made of R32 or a mixed refrigerant containing 70% by weight or more of R32 is used as a refrigerant. A refrigeration system for circulating and executing a refrigeration cycle, comprising the electric expansion valve for a refrigeration system according to any one of claims 1 to 3 as the expansion means.

Since the refrigerating apparatus according to the fourth aspect is provided with the electric expansion valve for the refrigerating apparatus according to any one of the first to third aspects as expansion means, malfunctions related to the expansion means are less likely to occur, Reliability is improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 schematically shows a cross-sectional structure of an electric expansion valve for a refrigerating apparatus according to one embodiment so as to show the features of the present invention. The basic configuration of the electric expansion valve is the same as that shown in FIG. 3, and the same components are denoted by the same reference numerals for easy understanding.

This electric expansion valve is provided with
The coolant passages 121 and 122 penetrating the lower portion 130b of the main body casing 130, and the coolant passages 121 and 1
And a slide hole 120 intersecting with the slide hole 22. The first refrigerant channel 121 is located on the vertical axis in the drawing and opens to the bottom surface side of the lower casing 130b. The second refrigerant flow path 122 is connected to the first refrigerant flow path 121,
The lower casing 130 is substantially perpendicular to the refrigerant flow path 121.
b. The slide hole 120 is the first
The first refrigerant flow path 1 is substantially coaxial with the refrigerant flow path 121.
21 to the opposite side to the upper part 130a of the main body casing 130
Extending to

A needle (valve rod) 123 is slidably fitted in the slide hole 120. Refrigerant channels 121 and 122 pass through slide holes 120 of needle 123.
Around the portion protruding to the opposite side to the rotor 13 of the motor.
9 are configured. The rotor 139 is a magnet
8, including the spacer 129 and the female screw 126, and integrally rotating about the central axis of the needle 123 as a rotation center.

The needle 123 is urged downward against the spacer 129 by a spring 127, and its lower position is regulated by a stopper metal 123a. Further, a male screw 125 is provided between the needle 123 and the female screw 126. This male screw 12
Reference numeral 5 denotes an outer side surface which is screwed with the female screw 126, while an inner side surface is configured to support the needle 123 so as to be slidable in the vertical direction, and is provided with the lower end fixed to the lower casing 130b. (See FIG. 3).

In the use state of the electric expansion valve, a coil (not shown) is arranged so as to surround the outer peripheral side of the upper casing 130a. A pulse motor using the coil and the magnet 128 as a driving source is configured.
The rotor 139 rotates around the axis. Here the female screw 126
And the male screw 125 are screwed with each other, so that the rotor 139 moves up and down in the main casing 130 with the rotation thereof. And the needle 123
Moves up and down with respect to the main body casing 130 in accordance with the pulse applied to the coil as the rotor 139 moves.

In this electric expansion valve, a gap (hereinafter, referred to as a "pressure reducing portion") 1 between the valve seat 114 and the needle tip portion 113 due to the vertical movement of the needle 123.
The size of 37 changes, and the flow rate of the refrigerant passing through the pressure reducing section 137 changes. Therefore, the refrigerant flowing between the first refrigerant flow channel 121 and the second refrigerant flow channel 122 can be expanded and the flow rate of the refrigerant can be adjusted. In such a refrigeration apparatus using the electric expansion valve, the flow rate of the refrigerant can be controlled according to the discharge pipe temperature and the like, and the efficiency (coefficient of performance) of the refrigeration cycle can be optimally controlled.

As described above, the malfunction of the electric expansion valve in the refrigerant circuit using the HFC-based refrigerant is caused by the needle 1
This is caused by the clogging of the threaded portions 125, 126, rather than the clogging of the gap between the tip of the valve 23 and the valve seat 114. Therefore, in this embodiment, when the distance between the screw portions 125 and 126 and the pressure reducing portion 137 is l ₁ (mm), l ₁ is set within the range of 5 ≦ l ₁ ≦ 11. Here, the distance l ₁ is from the lowermost part of the male screw 125 or the female screw 126 to the second refrigerant flow path 1.
22 means the distance to the center. Thus l ₁
Is set, the distance l ₁ between the screw portions 125 and 126 and the pressure reducing portion 137 can be sufficiently ensured.

The inner diameter of the refrigerant channels 121 and 122 is set to d ₁
(Mm), the ratio of l ₁ to d ₁ (l ₁ / d ₁ ) is set within the range of 0.7 ≦ (l ₁ / d ₁ ) ≦ 1.7. By setting the lower limit of (l ₁ / d ₁ ) in this way, the distance l ₁ between the screw portions 125 and 126 and the pressure reducing portion 137 can be substantially sufficiently secured.

The screw portions 125 and 126 and the needle 12
Assuming that the distance from the tip of No. 3 is l ₂ (mm), l ₂ is set within the range of 8 ≦ l ₂ ≦ 15. By setting the lower limit of l ₂ in this manner, the thread portions 125 and 126 and the needle 1
A sufficient distance l ₂ between the tip of the head 23 and the tip of the head 23 can be secured.

As described above, the refrigerant flow paths 121 and 12
2, the screw portions 125 and 126 can be sufficiently separated from each other. Therefore, the threaded portion 1 due to adhesion of sludge etc.
It is possible to effectively prevent clogging of 25 and 126, to prevent malfunction from occurring, and to improve reliability. The setting of the upper limit in (1) restricts the size of the electric expansion valve from becoming unnecessarily large.

[0033] In this embodiment, when further the length of the male screw 125 set to l ₀ (mm), l ₀
Is set in the range of 1.0 ≦ (l ₀ / d ₁ ) ≦ 1.7. By setting the lower limit of (l ₀ / d ₁ ) in this manner, the distance between the screw portions 125 and 126 and the pressure reducing portion 137 can be substantially sufficiently secured.

The number of threads of the male screw 125 is n (pieces)
In this case, the ratio (n / d ₁ ) between n and d ₁ is set in the range of 1.1 ≦ (n / d ₁ ) ≦ 3.6. If the pitch of the screw is constant (within the range), it can be said that the length of the screw and the number of screw threads are substantially proportional. Therefore, by setting the lower limit of (n / d ₁ ) in this way, the screw portions 125 and 126 and the pressure reducing portion 1
37 is substantially sufficient. In addition,
In this embodiment, the number n of threads of the male screw 125 is 7 ≦
It is set within the range of n ≦ 23.

The outer diameter of the rotor 139 of the motor, in this example, the outer shape of the upper casing 130a substantially the same as d ₂
(Mm), the ratio (d ₂ / d ₁ ) of d ₂ and d ₁ is set within a range of 7.0 ≦ (d ₂ / d ₁ ) ≦ 8.0. The number of threads and the torque required to rotate the screws are approximately proportional, and this torque is the size of the rotor of the motor (the outer diameter of the rotor is d ₂ , and the axial length of the motor is l ₃ . when there is a positive correlation between represented by ^{_{(πd 2 2 l 3/4}} ).). That is, it can be said that the number of threads has a positive correlation with the outer diameter of the rotor. Therefore, by setting the lower limit of (d ₂ / d ₁ ) in this manner, the distance between the screw portions 125 and 126 and the pressure reducing portion 137 can be substantially sufficiently secured.

According to the above, the refrigerant flow paths 121, 12
2, the screw portions 125 and 126 can be sufficiently separated from each other. Therefore, the threaded portion 1 due to adhesion of sludge etc.
It is possible to effectively prevent clogging of 25 and 126, to prevent malfunction from occurring, and to improve reliability. The setting of the upper limit in (1) restricts the size of the electric expansion valve from becoming unnecessarily large.

A durability test of this electric expansion valve was performed assuming an actual contamination level.
Even after the elapse of 0 hours, there was no problem in the operation state of the electric expansion valve.

In the above embodiment, the main body casing 13
The male screw 125 stops at 0, and the rotor 139 including the female screw 126 moves up and down together with the needle 123 with the rotation of the rotor 139 around the axis.
However, it is not limited to this. The rotor 139 including the female screw 126 may be stationary in the vertical direction, and the male screw 125 may move up and down together with the needle 123 as the rotor 139 rotates around the axis.

FIG. 2 shows a schematic configuration of an air conditioner having an electric expansion valve in a refrigerant circuit. The air conditioner connects the outdoor unit 20 and the indoor unit 1 with refrigerant pipes 41 and 4.
2 to form a refrigerant circuit, and R32 is circulated as a refrigerant through the refrigerant circuit. The indoor unit 1 houses an indoor heat exchanger 2 as a second heat exchanger. On the other hand, the refrigerant (R
32), a four-way switching valve 25 for switching the refrigerant flow path, an outdoor heat exchanger 22 as a first heat exchanger, and an electric expansion valve 2 as expansion means.
6 and an accumulator 2 for performing gas-liquid separation of the refluxed refrigerant
4, a receiver 29 for adjusting the amount of refrigerant between cooling and heating, and a microcomputer 60 for controlling the operation of the air conditioner are accommodated. The electric expansion valve 26 shown in FIG. 1 and satisfying the above conditions (1) to (4) is employed.

During the cooling operation for executing the refrigeration cycle,
According to the switching setting of the four-way switching valve 25, the refrigerant discharged by the compressor 23 passes through the pipe 31, the four-way switching valve 25, and the pipe 33 as shown by a solid line in FIG. Send to 22. This outdoor heat exchanger 2
The refrigerant condensed in 2 is sent to the indoor heat exchanger 2 serving as an evaporator through the pipe 36, the electric expansion valve 26 that narrows the flow path to expand the refrigerant, the throttle valve 27, and the first communication pipe 42. Further, the refrigerant vaporized in the indoor heat exchanger 2 is supplied to the compressor through the second communication pipe 41, the needle valve 28, the pipe 34, the four-way switching valve 25, the pipe 32, the receiver 29, the pipe 37, the accumulator 24, and the pipe 35. Return to 23. On the other hand, during the heating operation that executes the heat pump cycle,
The four-way switching valve 25 is switched, and the refrigerant discharged by the compressor 23 is passed through the pipe 31, the four-way switching valve 25, the pipe 34, the needle valve 28, and the second communication pipe 41 as shown by a broken line in FIG. To the indoor heat exchanger 2 which works as a condenser. The refrigerant condensed in the indoor heat exchanger 2 is sent to the first connection pipe 42, the throttle valve 27, the fully opened electric expansion valve 26, the pipe 36, and the outdoor heat exchanger 22 serving as an evaporator. Further, the refrigerant vaporized in the outdoor heat exchanger 22 is supplied to the pipe 3
3, four-way switching valve 25, pipe 32, receiver 29, pipe 3
7. Compressor 23 through accumulator 24 and pipe 35
Return to

In this air conditioner, since the motor-operated expansion valve 26 shown in FIG. 1 and satisfying the above-mentioned conditions (1) to (4) is employed, malfunctions associated with the motor-operated expansion valve 26 are less likely to occur. Therefore, the reliability of the air conditioner as a whole can be improved. In addition, since the contamination resistance is increased, it is possible to reuse the existing piping when installing the air conditioner.

The indoor unit 1 is provided with a temperature sensor 51 for detecting the indoor atmosphere temperature Troom and a temperature sensor 52 for detecting the indoor heat exchanger temperature Tin. The outdoor unit 20 has an outdoor atmosphere temperature Ta.
tm and an outdoor heat exchanger temperature T
out, and a compressor discharge temperature T
temperature sensor 55 for detecting dis, and compressor suction temperature T
A temperature sensor 56 for detecting suc is provided. The microcomputer 60 controls the operation of the refrigerant circuit based on the outputs of these temperature sensors and user settings.

In this embodiment, the air conditioner has been described. However, the present invention is not limited to this.
INDUSTRIAL APPLICABILITY The present invention can be widely applied to a refrigeration apparatus that executes a refrigeration cycle using R32 as a refrigerant.

Of course, the principle of the present invention is that R3
R32 as well as a single refrigerant consisting of
The present invention is also applied to a mixed refrigerant containing 0% by weight (wt.%) And has the same effect. As such a mixed refrigerant, for example, R32 is 70 to 90 wt. % And the remaining component is CO ₂ . In addition, R3 is used as an alternative refrigerant for old type refrigeration equipment.
When R2 is charged, the so-called retrofit or the service of the R22 machine is performed.
0 wt. %, And the remaining component is R22.

[0045]

As is clear from the above, in the electric expansion valve for a refrigeration system according to claims 1 to 3, since the distance (l ₁ ) between the screw portion and the pressure reducing portion is sufficiently ensured, sludge or the like is obtained. Clogging of the screw portion due to the adhesion of the adhesive can be effectively prevented. Therefore, it is possible to reduce malfunctions and improve reliability.

Further, in the refrigeration apparatus according to the fourth aspect, since such a motor-operated expansion valve is provided in the refrigerant circuit, reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a structure of an electric expansion valve for a refrigerating apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a schematic configuration of an air conditioner including the electric expansion valve in a refrigerant circuit.

FIG. 3 is a view showing a cross-sectional structure of a general electric expansion valve.

[Explanation of symbols]

 Reference Signs List 120 Slide hole 121 First refrigerant passage 122 Second refrigerant passage 123 Needle 125 Male screw 126 Female screw

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H052 AA01 BA03 BA31 BA32 BA35 DA01 EA16 3H062 AA02 AA15 BB33 CC01 DD01 EE08 FF41 HH04 HH09

Claims (4)

[Claims] 1. The body (130) is connected to the body (130).
And a slide hole (120) intersecting with the coolant passages (121, 122). A valve stem (123) is slidably inserted into the slide hole (120). The rotor (13) of the motor (13) is fitted around a portion of the valve stem (123) protruding from the slide hole (120) to the side opposite to the coolant flow paths (121, 122).
9), the rotor (139) and the valve stem (12)
3), a screw portion (125, 126) for converting the rotational movement of the rotor (139) around the axis into a linear movement in the axial direction of the valve stem (123) is provided. )
The refrigerant flow path (121, 1)
22) An electric expansion valve for a refrigeration system, which has a pressure reducing section (137) for expanding the refrigerant flowing through the screw section (125, 126) and the pressure reducing section (137).
A distance (l ₁ ) between the two is set to 5 mm or more. 2. The main body (130) is connected to the main body (130).
And a slide hole (120) intersecting with the coolant passages (121, 122). A valve stem (123) is slidably inserted into the slide hole (120). The rotor (13) of the motor (13) is fitted around a portion of the valve stem (123) protruding from the slide hole (120) to the side opposite to the coolant flow paths (121, 122).
9), the rotor (139) and the valve stem (12)
3), a screw portion (125, 126) for converting the rotational movement of the rotor (139) around the axis into a linear movement in the axial direction of the valve stem (123) is provided. )
The refrigerant flow path (121, 1)
22) An electric expansion valve for a refrigeration system, which has a pressure reducing section (137) for expanding the refrigerant flowing through the screw section (125, 126) and the pressure reducing section (137).
The distance between the a l _1, the coolant channel (121,12
The electric expansion valve for a refrigeration system, wherein (l ₁ / d ₁ ) ≧ 0.7, where d ₁ is the inner diameter of 2). 3. The main body (130) is connected to the main body (130).
Flow paths (121, 122) penetrating through the
Slide holes (120) intersecting the roads (121, 122)
And the valve stem (123) is inserted into the slide hole (120).
Sliding fit, slide of valve stem (123)
From the hole (120) to the refrigerant flow path (121, 122)
Around the part protruding to the opposite side, the rotor (13
9), the rotor (139) and the valve stem (12)
3) Rotational movement about the axis of the rotor (139) between
To the linear motion of the valve stem (123) in the axial direction.
(125, 126) to provide the valve stem (123)
The refrigerant flow path (121, 1)
22) A pressure reducing section (137) for expanding the refrigerant flowing through
In the electric expansion valve for a refrigeration system, the screw portion (125, 126) and the valve stem (123)
Distance to tip (l _Two) Is set to 8 mm or more
An electric expansion valve for a refrigeration system, comprising: 4. A refrigerant circuit comprising a compressor (23), a condenser (22), an expansion means (26) and an evaporator (2).
A single refrigerant consisting of R32 or R32 is used as the refrigerant.
A refrigeration apparatus that executes a refrigeration cycle by circulating a refrigerant mixture containing not less than weight percent, comprising the electric expansion valve for a refrigeration apparatus according to any one of claims 1 to 3 as the expansion means (26). A refrigeration apparatus characterized by the above-mentioned.