JP7341280B2 - Electric valve and refrigeration cycle system - Google Patents

Description

The present invention relates to a needle-type motorized valve for controlling the flow rate of refrigerant in an air conditioner, etc., and particularly to a motorized valve with an improved valve port shape relative to the needle valve, and a refrigeration cycle system equipped with such a motorized valve. Regarding.

BACKGROUND ART Conventionally, in a refrigeration cycle, noise generated from an electric valve that controls the flow rate of refrigerant and accompanying passage of fluid often poses a problem. An example of an electric valve that takes such noise countermeasures is disclosed in Japanese Patent No. 5,696,093 (Patent Document 1).

The electric valve disclosed in Patent Document 1 includes a valve port including a first port and a second port, and a tapered portion is provided between the first port and the second port. Furthermore, the inner diameter of the second port is made slightly larger than the inner diameter of the first port, and the length of the second port is made sufficiently longer than the length of the first port.

In Patent Document 1, as shown in FIG. 5, the refrigerant that has passed through the gap between the needle valve a and the first port b flows to the secondary joint pipe side through the tapered part c and the second port d. . At this time, the refrigerant that has passed through the gap between the needle valve a and the first port b flows along the inner wall of the second port d, following the tapered portion c. The inner diameter of the second port d is only slightly larger than the inner diameter of the first port b, so that the pressure does not recover suddenly while flowing from the first port b to the second port d. Furthermore, since the length of the second port d is sufficiently long, the flow of the refrigerant is rectified at the second port d. Therefore, cavitation bursting can be suppressed, the flow of the refrigerant can be stabilized, and noise can be reduced.

Patent No. 5696093

Although the invention of Patent Document 1 also has the effect of reducing noise, it may generate noise under certain refrigerant conditions. For example, in Patent Document 1, the flow of fluid can be rectified at the second port, but this second port has a slightly larger inner diameter than the first port, and its length is sufficiently longer than that of the first port. It's getting longer. Therefore, although the fluid is rectified, the flow velocity within this second port is not slowed down, and noise may be generated due to flow velocity sound (sound caused by high flow velocity). In particular, when the load is high, the differential pressure across the valve port is high, and this flow velocity noise is a major cause of noise.

An object of the present invention is to provide an electric valve with reduced noise by improving a valve port, and a refrigeration cycle system equipped with such an electric valve.

The motor-operated valve according to claim 1 is an electrically-operated valve that communicates a valve chamber with which a primary joint pipe communicates with a secondary joint pipe through a valve port, and the valve port is provided with a valve chamber on the valve chamber side. a first port whose opening area is increased or decreased by a needle valve; a second port having an inner diameter larger than the first port into which the needle valve that has passed through the first port can be inserted; and the first port and the second port. In the motor-operated valve, the motor-operated valve includes a first tapered portion that connects the valve port to a third port located on the secondary joint pipe side, and a second tapered portion that connects the second port and the third port. The relationship between the inner diameter D1 of the first port, the inner diameter D2 of the second port, and the inner diameter D3 of the third port is D1<D2<D3, and the first port, the second port, and the third port has a cylindrical side surface shape centered on each axis, and the length of the second port in the direction of the axis is equal to the length of the second port on the secondary joint pipe side. The length is shorter than the length from the opening to the opening on the secondary joint pipe side of the valve port, and the inner diameter of the flow path increases from the first port to the secondary joint pipe.
Further, another motor-operated valve is an electrically-operated valve that communicates a valve chamber with which a primary joint pipe communicates with a secondary joint pipe through a valve port, and the valve port is provided on the valve chamber side. An electric valve comprising a first port whose opening area is increased or decreased by a needle valve, a second port having an inner diameter larger than the first port, and a first tapered portion connecting the first port and the second port, The valve port includes a third port located on the secondary joint pipe side, and a second tapered portion connecting the second port and the third port, and the inner diameter D1 of the first port and the second port The relationship between the inner diameter D2 of the inner diameter D3 and the inner diameter D3 of the third port is D1<D2<D3, and the first port, the second port, and the third port are cylindrical columns centered on their respective axes. In the direction of the axis, the length of the first port is L1, the length of the first tapered part and the second port is L2, and the length of the second tapered part and the third port is L2. When the length from the port is L3, 1≦L3/L2≦5, which indicates that the opening of the valve port on the secondary joint pipe side is located inside the secondary joint pipe. Features.
The motor-operated valve according to claim 2 is the motor-operated valve according to claim 1, wherein the opening on the secondary joint pipe side of the valve port is located inside the inner circumferential surface of the secondary joint pipe. , and an end of the secondary joint pipe on the valve chamber side is located closer to the valve chamber than an opening of the valve port on the secondary joint pipe side.
The motor-operated valve according to claim 3 is the motor-operated valve according to claim 1 or 2, wherein the inner diameter of the second port is larger than the length of the second port, and the inner diameter of the third port is larger than the length of the second port. It is characterized by a length greater than that of 3 ports.
The refrigeration cycle system according to claim 4 includes a compressor that compresses a refrigerant, a condenser that condenses the compressed refrigerant, a throttle device that expands the condensed refrigerant, and an evaporator that evaporates the expanded refrigerant. A refrigeration cycle system comprising the following, characterized in that the electric valve according to any one of claims 1 to 3 is used as the throttle device.

The electric valve is
D2-D1≦D3-D2
It is preferable that

Further, the electric valve has a taper angle of θ1 of the first tapered portion, a taper angle of θ2 of the second tapered portion, a length of the first port of L1, and a length of the first tapered portion and the second port. When the length is L2 and the length of the second tapered part and the third port is L3,
1mm≦D1≦4.5mm,
60°≦θ1≦150°,
20°≦θ2≦90°,
0.1mm≦L1≦0.5mm,
1≦L2/L1≦39
1<L3/L2≦38
1.03≦D2/D1≦1.5
1.02≦D3/D2≦5.52
It is preferable that

According to the electric valve according to claims 1 to 3 and the refrigeration cycle system according to claim 4, when the refrigerant flowing from the gap between the first port and the needle valve flows out to the second port, the pressure in the second port is suddenly increased. The flow of the refrigerant can be stabilized by rectifying the flow without recovery, and cavitation bursting can be suppressed. Furthermore, since the flow velocity is reduced when flowing from the second port to the second tapered portion and the third port, flow velocity noise can be reduced. Therefore, noise can be reduced.

In addition, according to the above-mentioned preferred electric valve, since D2-D1≦D3-D2, the diameter of the second port greatly increases from the second taper part to the third port, which reduces the flow velocity. The effect is enhanced and flow velocity noise can be further reduced.

FIG. 1 is a longitudinal cross-sectional view of an electric valve according to an embodiment of the present invention. FIG. 2 is an enlarged vertical cross-sectional view of a main part near a valve port in an electrically operated valve according to an embodiment of the present invention. It is a figure explaining the effect|action of the valve port in the electric valve of embodiment of this invention. 1 is a diagram showing an example of an air conditioner using an electric valve according to an embodiment of the present invention. It is a figure explaining the effect|action of the valve port of the conventional motor-operated valve.

Next, embodiments of the electric valve of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of the motor-operated valve according to the embodiment, FIG. 2 is an enlarged longitudinal cross-sectional view of the main part near the valve port in the motor-operated valve according to the embodiment, and FIG. 3 is a diagram illustrating the function of the valve port in the motor-operated valve according to the embodiment. , FIG. 4 is a diagram showing an example of an air conditioner using the electric valve of the embodiment.

First, an air conditioner according to an embodiment will be described based on FIG. 4. The air conditioner includes the electric valve 10 of the embodiment, an outdoor heat exchanger 20 mounted on the outdoor unit 100, an indoor heat exchanger 30 mounted on the indoor unit 200, a flow path switching valve 40, and a compressor 50. Each of these elements is connected by a conduit as shown in the figure, and constitutes a heat pump type refrigeration cycle. This refrigeration cycle is an example of a refrigeration cycle to which the electric valve of the present invention is applied. It can also be applied to other systems, such as a diaphragm device on the indoor unit side of multi-air conditioners for buildings.

The flow path of the refrigeration cycle is switched between two flow paths, heating mode and cooling mode, by the flow path switching valve 40, and in the heating mode, the refrigerant compressed by the compressor 50 is switched to the flow path as shown by the solid arrow. Refrigerant flowing into the indoor heat exchanger 30 from the valve 40 and flowing out from the indoor heat exchanger 30 flows into the electric valve 10 through the pipe line 60. The refrigerant is expanded by this electric valve 10 and circulated through the outdoor heat exchanger 20, the flow path switching valve 40, and the compressor 50 in this order. In the cooling mode, as shown by the dashed arrow, refrigerant compressed by the compressor 50 flows into the outdoor heat exchanger 20 from the flow path switching valve 40, and refrigerant flowing out from the outdoor heat exchanger 20 is passed through the electric valve 10. It is expanded and flows through the conduit 60 into the indoor heat exchanger 30. The refrigerant flowing into the indoor heat exchanger 30 flows into the compressor 50 via the flow path switching valve 40. In the example shown in FIG. 4, the refrigerant is configured to flow from the primary joint pipe 21 of the electric valve 10 to the secondary joint pipe 22 during the heating mode, but by reversing the piping connections, the refrigerant flows during the heating mode. , the refrigerant may be configured to flow from the secondary joint pipe 22 to the primary joint pipe 21.

The electric valve 10 functions as a throttle device that controls the flow rate of the refrigerant, and in heating mode, the outdoor heat exchanger 20 functions as an evaporator and the indoor heat exchanger 30 functions as a condenser, heating the room. . In the cooling mode, the outdoor heat exchanger 20 functions as a condenser, the indoor heat exchanger 30 functions as an evaporator, and the room is cooled.

Next, the electric valve 10 of the embodiment will be described based on FIGS. 1 and 2. This electric valve 10 has a valve housing 1, and a cylindrical valve chamber 1A is formed in the valve housing 1. Further, a first port 11, a second port 12, and a third port 13 are formed in the valve housing 1. Further, a first tapered portion 14 is formed between the first port 11 and the second port 12, and a second tapered portion 15 is formed between the second port 12 and the third port 13. Furthermore, a primary joint pipe 21 that communicates with the valve chamber 1A from the side surface is attached to the valve housing 1, and a secondary joint pipe 22 is attached to one end of the valve chamber 1A in the axis X direction. The valve chamber 1A and the secondary joint pipe 22 can be electrically connected to each other through the first port 11, the first tapered portion 14, the second port 12, the second tapered portion 15, and the third port 13.

A support member 3 is attached to the upper part of the valve housing 1. A guide hole 3a that is long in the direction of the axis X is formed in the support member 3, and a cylindrical valve holder 4 is fitted into the guide hole 3a so as to be slidable in the direction of the axis X. The valve holder 4 is attached coaxially with the valve chamber 1A, and a valve body 5 having a needle valve 5a at the end is fixed to the lower end of the valve holder 4. Further, a spring receiver 41 is provided within the valve holder 4 so as to be movable in the axis X direction, and a compression coil spring 42 is attached between the spring receiver 41 and the valve body 5 with a predetermined load applied thereto. ing.

A case 61 of a stepping motor 6 is airtightly fixed to the upper end of the valve housing 1 by welding or the like. A magnet rotor 62 whose outer periphery is magnetized with multiple poles is rotatably provided inside the case 61, and a rotor shaft 63 is fixed to the magnet rotor 62. The upper end of the rotor shaft 63 is rotatably fitted into a cylindrical guide 64 hanging from the ceiling of the case 61 . Further, a stator coil 65 is disposed around the outer periphery of the case 61, and when a pulse signal is applied to the stator coil 65, the magnet rotor 62 is rotated according to the number of pulses. The rotation of the magnet rotor 62 causes the rotor shaft 63, which is integrated with the magnet rotor 62, to rotate. Note that a rotation stopper mechanism 66 for the magnet rotor 62 is provided on the outer periphery of the guide 64.

The upper end of the valve holder 4 is engaged with the lower end of the rotor shaft 63 of the stepping motor 6, and the valve holder 4 is supported by the rotor shaft 63 in a rotatable suspended state. Further, the rotor shaft 63 is formed with a male threaded portion 63a, and this male threaded portion 63a is screwed into a female threaded portion 3b formed on the support member 3.

With the above configuration, the rotor shaft 63 moves in the axis X direction as the magnet rotor 62 rotates. Due to the movement of the rotor shaft 63 in the axis X direction along with this rotation, the valve body 5 moves in the axis X direction together with the valve holder 4. The valve body 5 increases or decreases the opening area of the first port 11 at the needle valve 5a, and controls the flow rate of fluid flowing from the primary joint pipe 21 to the secondary joint pipe 22.

The first port 11, the second port 12, and the third port 13 have the shape of a cylindrical side surface centered on the axis X, and as shown in FIG. 2, the inner diameter D1 of the first port 11 is The dimensions match the outer circumference of the Further, the inner diameter D2 of the second port 12 is slightly larger than the inner diameter D1 of the first port 11. The inner diameter D3 of the third port 13 is larger than the inner diameter D21 of the second port 12 and smaller than the inner diameter D4 of the secondary joint pipe 22. Note that in FIG. 2, each of the diameters D1 to D4 is appended with "φ" indicating the diameter. The length L1 of the first port 11 is smaller than the inner diameter D1, and the combined length L2 of the first tapered portion 14 and the second port 12 is larger than the length L1 of the first port 11. It has become. The combined length L3 of the second tapered portion 15 and the third port 13 is larger than the combined length L2 of the first tapered portion 14 and the second port 12.

The first tapered portion 14 and the second tapered portion 15 have the shape of a truncated conical side surface centered on the axis X, and the inner surface of the first tapered portion 14 has an inner diameter from the first port 11 to the second port 12. The inner diameter of the inner surface of the second tapered portion 15 is enlarged from the second port 12 to the third port 13. The taper angle θ1, which is the opening angle of the first tapered portion 14, and the taper angle θ2, which is the opening angle of the second tapered portion 15, are set appropriately. Note that these dimensions and angles are not limited to those shown in FIG. 2, and conditions for these dimensions and angles will be described later.

As shown in FIG. 3, the refrigerant that has passed through the gap between the needle valve 5a and the first port 11 passes through the first tapered part 14, the second port 12, the second tapered part 15, and the third port 13, and then enters the secondary joint. Flows into pipe 22. At this time, the gap between the needle valve 5a and the first port 11 is the narrowest point, and the flow velocity is maximum here, but the length L1 of the first port 11 is as short as possible, and the flow passes through this gap. The refrigerant flows immediately along the inner wall of the second port 12 following the first tapered portion 14 . The inner diameter D2 of the second port 12 is only slightly larger than the inner diameter D1 of the first port 11, so that the pressure does not suddenly recover while flowing from the first port 11 to the second port 12. Furthermore, since the second port 12 is long, the flow of the refrigerant is rectified at the second port 12. Therefore, cavitation bursting can be suppressed, and the flow of the refrigerant can be stabilized.

The flow of refrigerant that has passed through the second port 12 follows the second tapered portion 15 and flows to the third port 13 while recovering or increasing the pressure. Since the inner diameter D3 of the third port 13 is larger than the inner diameter D2 of the second port 12, the flow velocity is reduced while flowing along the second tapered portion 15. In other words, the second port 12 straightens the flow to some extent and immediately reduces the flow velocity, thereby reducing the flow noise. Further, the flow of the refrigerant decelerated through the second tapered portion 15 flows to the third port 13, but since the flow of the refrigerant has already been rectified at the second port 12, there is no flow within this third port 13. , the flow of refrigerant is less likely to be disturbed, and cavitation bursting can be suppressed.

In this way, by rectifying the flow to some extent at the second port 12 and flowing it to the third port 13 via the second taper section 15, the flow velocity can be reduced while maintaining the flow rectification at the second taper section 15. Thereby, the turbulence of the flow at the third port 13 can be reduced to suppress cavitation bursting, and the second tapered portion 15 can decelerate the flow velocity to reduce flow velocity sound. That is, since the length of the second port 12 is shorter than that of Patent Document 1, flow velocity noise can be reduced.

The electric valve 10 in the embodiment has a high effect of reducing flow velocity noise when the pressure difference between the primary joint pipe 21 and the secondary joint pipe 22 is high. The dimensions and angles of each part of the port 13, the first tapered part 14, the second tapered part 15, and the secondary joint 22 are set so as to satisfy the following conditions.

Below, when the pressure difference between the primary joint pipe 21 and the secondary joint pipe 22 is high, the conditions of the dimensions and angles of each part of the embodiment that is highly effective in reducing flow velocity sound are shown. The inner diameter D1 of the first port 11 is
1mm≦D1≦4.5mm
and the inner diameter D2 of the second port 12 is
1.15mm≦D2≦4.9mm
And the inner diameter D3 of the third port 13 is
4.6mm≦D3≦6.35mm
And the inner diameter D4 of the secondary joint 22 is
6.35mm≦D4
It is.

Further, the taper angle θ1 of the first tapered portion 14 is
60°≦θ1≦150°
The taper angle θ2 of the second tapered portion 15 is within the range of
20°≦θ2≦90°
is within the range of

Moreover, the length L1 of the first port 11 is
0.1mm≦L1≦0.5mm
The shorter this L1, the lower the noise. The length L2 of the first tapered portion 14 and the second port 12 is
0.5mm≦L2≦3.9mm
The combination of these lengths L1 and L2 is L1+L2,
1mm≦L1+L2≦4mm
It is set according to the conditions. Further, the sum L1+L2+L3 of the length L1 of the first port 11, the length L2 of the first tapered part 14 and the second port 12, and the length L3 of the second tapered part 15 and the third port 13 is,
6mm≦L1+L2+L3≦23mm
It is.

Further, the ratio L2/L1 of the length L2 of the first tapered portion 14 and the second port 12 and the length L1 of the first port 11 is as follows:
1≦L2/L1≦39
The ratio L3/L2 of the length L3 of the second tapered part 15 and the third port 13 and the length L2 of the first tapered part 14 and the second port 12 is within the range of
0.57<L3/L2≦38 (preferably 1<L3/L2≦38)
The dimensional ratio D2/D1 of the inner diameter D2 of the second port 12 and the inner diameter D1 of the first port 11 is
1.03≦D2/D1≦1.5
The dimensional ratio D3/D2 of the inner diameter D3 of the third port 13 and the inner diameter D2 of the second port 12 is within the range of
1.02≦D3/D2≦5.52
is within the range of

Next, actual measurement examples of each dimensional ratio and noise reduction for the electric valve of the embodiment will be described. In this actual measurement example, the operating conditions were that the pressure in the primary joint pipe 21 was 2.8 to 3.4 (MPa) and the pressure in the secondary joint pipe 22 was 1.2 to 1.8 (MPa). The noise measured with the electric valve of the embodiment is compared with the noise measured with the electric valve of Patent Document 1 (under its conditions). That is, this is an actual measurement example showing that the effect of noise reduction is particularly remarkable under conditions where flow velocity noise is likely to occur under high loads. Actual measurement examples are shown in Tables 1 to 6 below. In Tables 1 to 6, cases where the sound pressure has decreased by 2 dB or more compared to the noise in the electric valve of Patent Document 1 are indicated by "○○○", and cases where the sound pressure has decreased by 1 to 2 dB are indicated by "○○". It shows. Further, cases where the decrease in sound pressure is 1 dB or less are indicated by "○". Note that the sound pressure is evaluated using A characteristics.

Table 1 shows the relationship between L2/L1 and θ1.

Table 2 shows the relationship between L2/L1 and D2/D1.

Table 3 shows the relationship between L2/L1 and θ2.

Table 4 shows the relationship between L2/L1 and D3/D2.

Table 5 shows the relationship between D3/D2 and θ2.

Table 6 shows the relationship between D3/D2 and L3/L2.

As can be seen from these tables, by providing the third port and the second tapered portion, noise reduction is achieved compared to the conventional case. Furthermore, even if the pressure difference between the primary joint pipe 21 and the secondary joint pipe 22 is high, if the pressure difference is within the range of "○○" and "○○○", the noise can be reduced by 1 dB or more, making it more noticeable. effect can be obtained.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the design may be changed without departing from the gist of the present invention. Even if there is, it is included in the present invention.

1 Valve housing 1A Valve chamber 11 First port 12 Second port 13 Third port 14 First tapered part 15 Second tapered part 21 Primary joint pipe 22 Secondary joint pipe 3 Support member 4 Valve holder 5 Valve body 5a Needle valve 6 Stepping motor X axis

Claims (4)

A motor-operated valve that communicates a valve chamber with which a primary joint pipe communicates with a secondary joint pipe via a valve port, the opening area of which is increased or decreased by a needle valve provided on the valve chamber side of the valve port. a second port having a larger inner diameter than the first port into which the needle valve that has passed through the first port can be inserted; a first tapered portion connecting the first port and the second port; In an electric valve equipped with
The valve port includes a third port located on the secondary joint pipe side, and a second tapered portion connecting the second port and the third port, and the inner diameter D1 of the first port and the second port The relationship between the inner diameter D2 of the third port and the inner diameter D3 of the third port is D1<D2<D3,
The first port, the second port, and the third port have the shape of a cylindrical side surface centered on each axis,
In the direction of the axis, the length of the second port is shorter than the length from the opening of the second port on the secondary joint pipe side to the opening of the valve port on the secondary joint pipe side, An electric valve characterized in that the inner diameter of the flow path increases from the first port to the secondary joint pipe. The opening of the valve port on the secondary joint pipe side is located inside the inner peripheral surface of the secondary joint pipe, and the end of the secondary joint pipe on the valve chamber side is located in the valve port. The motor-operated valve according to claim 1, wherein the motor-operated valve is located closer to the valve chamber than the opening on the secondary joint pipe side. The inner diameter of the second port is larger than the length of the second port,
The motor-operated valve according to claim 1 or 2, wherein an inner diameter of the third port is larger than a length of the third port. A refrigeration cycle system including a compressor that compresses a refrigerant, a condenser that condenses the compressed refrigerant, a throttle device that expands the condensed refrigerant, and an evaporator that evaporates the expanded refrigerant. hand,
A refrigeration cycle system characterized in that the electric valve according to any one of claims 1 to 3 is used as the throttle device.

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