JP7466485B2 - Motor-operated valve - Google Patents

Description

The present invention relates to a motor-operated valve.

Conventionally, a flow control valve has been proposed as an electrically operated valve, which includes a first valve body portion and a second valve body portion, and can be set to a small flow control state or a large flow control state (see, for example, Patent Document 1). In the flow control valve described in Patent Document 1, a sound absorbing member is provided in the communication passage of the connecting shaft of the valve shaft, and a sound absorbing member is also provided in the communication passage of the valve body member. By providing a sound absorbing member in this way, it is possible to reduce both noise and pressure loss in the large opening range.

JP 2017-211034 A

However, in an electric valve that can be set to a low flow rate control state or a high flow rate control state as described in Patent Document 1, the fluid that passes through (flows out of) the valve port (auxiliary valve port) that corresponds to low flow rate control is likely to become unstable (a state in which large and small air bubbles are mixed) and is likely to become a jet. For this reason, even if a sound-absorbing member is placed downstream of the auxiliary valve port, the fluid has difficulty passing through this sound-absorbing member, and the fluid becomes even more unstable, making it difficult to sufficiently reduce noise.

The object of the present invention is to provide an electric valve that can stabilize the flow of fluid and reduce noise.

The motor-operated valve of the present invention comprises a valve housing, a main valve body that changes the opening of a main valve port of a main valve chamber provided in the valve housing, a sub-valve body that changes the opening of a sub-valve port of a sub-valve chamber provided in the main valve body, and a drive unit that drives the sub-valve body forward and backward in the axial direction, and is an electric valve in which a communication passage is formed to connect the main valve chamber and the sub-valve chamber, and further comprises a first sound-absorbing member disposed in a flow path from the communication passage to the sub-valve port, and a second sound-absorbing member disposed in a flow path from the sub-valve port to the main valve port, the first sound-absorbing member and the second sound-absorbing member being formed to subdivide the flow path, and the first sound-absorbing member having a higher density than the second sound-absorbing member.

According to the present invention as described above, the first sound-absorbing member arranged in the flow path from the communication passage to the auxiliary valve port has a higher density than the second sound-absorbing member arranged in the flow path from the auxiliary valve port to the main valve port, so that the fluid passes through the high-density first sound-absorbing member and then the low-density second sound-absorbing member. This reduces noise by allowing the fluid to flow into the auxiliary valve port with the air bubbles sufficiently broken down by the first sound-absorbing member, and the fluid passes through the low-density second sound-absorbing member that has flowed out from the auxiliary valve port, making it less likely for the fluid to stagnate when passing through the second sound-absorbing member. This stabilizes the flow of the fluid and further reduces noise.

In this case, in the motor-operated valve of the present invention, it is preferable that the communication passage is formed on the side surface of the cylindrical portion of the main valve body, and an annular space is formed along the cylindrical portion between the communication passage and the first silencing member. With this configuration, the fluid is more likely to reach the first silencing member after passing through the annular space in a circulating manner, and the speed of the fluid can be reduced before it reaches the first silencing member.

In addition, in the motor-operated valve of the present invention, it is preferable that a plurality of communication passages that communicate with the annular space are formed on the side surface of the cylindrical portion. With this configuration, it is possible to reduce the bias in the flow rate of the fluid in the circumferential direction compared to a configuration in which the fluid is introduced into the auxiliary valve chamber from a single communication passage.

In addition, in the motor-operated valve of the present invention, it is preferable that the annular space and the first silencing member are arranged side by side in the axial direction of the annular space. With this configuration, the extension direction of the communication passage formed in the cylindrical portion intersects with the direction from the annular space toward the first silencing member, and the speed of the fluid can be reduced before it reaches the first silencing member.

In the motor-operated valve of the present invention, the first and second sound-absorbing members are preferably filters formed in a three-dimensional mesh shape, and the first and second sound-absorbing members are preferably formed in a three-dimensional mesh shape by randomly bending linear members. With this configuration, the linear members are randomly bent, so that the sound-absorbing members have passages with various sizes of passable areas through which fluid can pass. Therefore, even if the fluid contains bubbles of various sizes, the bubbles can be easily broken down into fine bubbles.

The motor-operated valve of the present invention can stabilize the flow of fluid and reduce noise.

1 is a cross-sectional view showing a motor-operated valve according to an embodiment of the present invention. 2 is an enlarged cross-sectional view showing a main part of the motor-operated valve. FIG. 4 is a cross-sectional view showing a communication passage and an annular space of the motor-operated valve; FIG.

An embodiment of the present invention will be described with reference to the drawings. The motor-operated valve 1 of this embodiment is used in the refrigeration cycle system of an air conditioner such as a packaged air conditioner or a room air conditioner, and as shown in FIG. 1, comprises a valve housing 2, a guide member 3, a main valve body 4, a sub-valve body 5, a drive unit 6, a first sound-absorbing member 7, and a second sound-absorbing member 8. The main valve body 4 and the sub-valve body 5 are arranged to move along a predetermined axial direction, and in the following, this axial direction is referred to as the Z direction, and the two directions perpendicular to the Z direction are referred to as the X direction and the Y direction, with the top and bottom in the Z direction being based on FIG. 1.

The valve housing 2 is formed in a generally cylindrical shape from, for example, brass or stainless steel, and has a main valve chamber 2R inside. The valve housing 2 has a first port 21 that opens to one side in the X direction on its side, and a second port 22 that opens to the lower side in the Z direction. A first joint tube 11 extending along the X direction is connected to the first port 21, and a second joint tube 12 extending along the Z direction is connected to the second port 22, and the first joint tube 11 and the second joint tube 12 communicate with the main valve chamber 2R. The first joint tube 11 and the second joint tube 12 may be fixed to the valve housing 2 by, for example, brazing.

At the lower end of the valve housing 2, a cylindrical main valve seat 23 is formed that protrudes (upward) toward the main valve chamber 2R with the Z direction as the axial direction, and the inside of this main valve seat 23 is the main valve port 23a, which communicates with the second port 22. That is, the second joint pipe 12 is connected to the main valve chamber 2R via the main valve port 23a. In this embodiment, the motor-operated valve 1 is used such that the first port 21 is the primary side and the second port 22 is the secondary side, and the fluid (refrigerant) that flows from the first joint pipe 11 into the main valve chamber 2R flows out from the second joint pipe 12, but the motor-operated valve 1 may be incorporated into a cycle in which fluid can flow in both directions.

The guide member 3 is attached to the opening at the upper end of the valve housing 2, and has a press-fit portion 31 that is press-fitted into the inner peripheral surface of the valve housing 2, a roughly cylindrical guide portion 32 located inside the press-fit portion 31, a holder portion 33 that extends from the upper portion of the guide portion 32, a stopper portion 34 provided above the holder portion 33, and a ring-shaped flange portion 35 located on the outer periphery of the guide portion 32. The press-fit portion 31, guide portion 32, holder portion 33, and stopper portion 34 are configured as a single piece made of resin. The flange portion 35 is a metal plate made of, for example, brass or stainless steel, and this flange portion 35 is provided integrally with the resin press-fit portion 31 and holder portion 33 by insert molding.

The guide member 3 is assembled to the valve housing 2 and fixed to the upper end of the valve housing 2 at the flange portion 35 by welding. In addition, the guide member 3 has a cylindrical guide hole 32a with the axial direction in the Z direction formed in the guide portion 32, and an insertion hole 33a coaxial with the guide hole 32a formed in the center of the holder portion 33. In addition, a female thread portion (threaded hole) 34a coaxial with the guide hole 32a and the insertion hole 33a is formed in the center of the stopper portion 34.

The main valve body 4 is disposed in the guide hole 32a of the holder portion 33, and as shown in FIG. 2, is formed in a cylindrical shape with the axial direction being the Z direction. The main valve body 4 integrally includes a partition portion 41 that extends along the XY plane and to which the sub-valve body 5 approaches or moves away, a cylindrical portion 42 that extends from the partition portion 41 toward the opposite side (upward) from the main valve port 23a, and a main valve portion 43 that approaches or moves away from the main valve seat 23.

The partition wall 41 is an auxiliary valve seat provided at the lower end of the tubular portion 42, and is formed in a plate shape having a predetermined plate thickness (Z-direction dimension). The partition wall 41 and the tubular portion 42 form a bottomed tubular portion, and the inside of this bottomed tubular portion becomes the auxiliary valve chamber 4R. A sub-valve port 41a, which is a through hole, is formed in the center of the partition wall 41. The tubular portion 42 is formed in a cylindrical shape, and a pressing member 93 described later is provided inside it, and the inner surface of the pressing member 93 functions as a needle guide hole. A guide boss portion 53 attached to a valve shaft 51 described later is inserted into this needle guide hole, and a ring-shaped retainer 44 is fixed to the upper end of the tubular portion 42 by fitting or welding. In addition, a main valve spring 4a is disposed between the retainer 44 and the upper end of the guide hole 32a, and the main valve body 4 is biased toward the main valve seat 23 (downward in the Z direction; closing direction) by this main valve spring 4a.

As shown in FIG. 3, the cylindrical portion 42 has a plurality of communication passages 421 (eight in this embodiment) that communicate between the inside and outside of the cylindrical portion 42. The eight communication passages 421 are arranged at equal intervals in the circumferential direction centered on the Z direction. The communication passages 421 formed in the cylindrical portion 42 allow communication between the main valve chamber 2R, the sub-valve chamber 4R, the sub-valve port 41a, and the main valve port 23a.

The partition wall 41 is formed with a cylindrical portion 411 extending upward in the Z direction, an annular space 412 located outside the cylindrical portion 411, and an inclined surface 413 continuing to the lower surface of the annular space 412. The cylindrical portion 411 has an auxiliary valve port 41a formed on the inside. The annular space 412 is formed in an annular shape along the inside of the cylindrical portion 42, and is connected to a plurality of communication passages 421. The inclined surface 413 inclines upward from the lower end of the communication passage 421 toward the inner periphery, and is connected to the lower surface of the annular space 412. As a result, when viewed from the radial direction, the communication passages 421 and the annular space 412 overlap, and the annular space 412 is slightly offset upward.

The main valve portion 43 is formed in a generally cylindrical shape such that the tubular portion 42 extends downward beyond the partition portion 41. The main valve portion 43 is arranged to seat (contact) against the main valve seat 23 in the fully closed state.

The sub-valve body 5 is a needle valve that is provided at the lower end of the rotor shaft 61 (described later) and integrally includes a valve shaft 51 that is connected to the rotor shaft 61 side and a needle portion 52 that is connected to the lower end of the valve shaft 51. The sub-valve body 5 further includes a guide boss portion 53 that is fixed to the valve shaft 51. The guide boss portion 53 is fixed separately from the valve shaft 51, but the guide boss portion 53 may be formed integrally with the valve shaft 51. The guide boss portion 53 is slidably inserted into a needle guide hole formed by the pressing member 93.

The drive unit 6 is provided inside and outside the case 24 fixed to the upper end of the valve housing 2, and has a stepping motor 6A, a screw feed mechanism 6B that moves the sub-valve body 5 forward and backward by the rotation of the stepping motor 6A, and a stopper mechanism 6C that regulates the rotation of the stepping motor 6A. The case 24 is fixed airtightly to the valve housing 2, for example by welding.

The stepping motor 6A is composed of a rotor shaft 61, a magnet rotor 62 rotatably arranged inside the case 24, a stator coil (not shown) arranged facing the magnet rotor 62 on the outer periphery of the case 24, and other yokes and exterior members (not shown). The rotor shaft 61 is attached to the center of the magnet rotor 62 via a bush, and a male thread 61a is formed on the outer periphery of the rotor shaft 61 on the guide member 3 side. This male thread 61a is screwed into the female thread 34a of the guide member 3, so that the guide member 3 supports the rotor shaft 61 on an axis along the Z direction. The female thread 34a of the guide member 3 and the male thread 61a of the rotor shaft 61 constitute the screw feed mechanism 6B.

The first silencing member 7 is formed in an annular shape as a whole so that the valve shaft 51 and the needle portion 52 can pass through, and is arranged in the flow path from the communication passage 421 to the sub-valve port 41a. The first silencing member 7 is a filter formed in a three-dimensional mesh shape by randomly bending a linear member. The first silencing member 7 may be, for example, a demister. The first silencing member 7 formed in a mesh shape functions to subdivide the flow path, and the fluid (refrigerant) passes through the first silencing member 7 while being subdivided. That is, when a fluid in a gas-liquid mixed state passes through the first silencing member 7, the bubbles are subdivided. At this time, since the linear member of the first silencing member 7 is randomly bent, the first silencing member 7 has various sizes of passable areas as passage parts through which the fluid can pass. In addition, when the fluid passes through the first silencing member 7 along a predetermined passing direction, the passable area changes depending on the passing direction position. This allows bubbles of various sizes to be subdivided.

As shown in FIG. 2, the first silencing member 7 is fixed in the cylindrical portion 42 of the main valve body 4 by a pair of fixing members 91A, 91B and a pressing member 93. The first silencing member 7 is sandwiched between the pair of fixing members 91A, 91B from the Z direction, and the pressing member 93 is arranged on the upper side of the fixing members 91A, 91B. The first silencing member 7, the fixing members 91A, 91B, and the pressing member 93 are sandwiched and fixed between the partition portion 41 and the retainer 44 from the Z direction. At this time, the first silencing member 7 is arranged on the upper side so as to be aligned with the annular space 412 in the Z direction. The pair of fixing members 91A, 91B each have a communication portion 92A, 92B consisting of a plurality of through holes extending in the Z direction. As a result, the annular space 412 communicates with the space in which the first silencing member 7 is disposed, and the space in which the first silencing member 7 is disposed communicates with the sub-valve chamber 4R. That is, when the fluid flows from the annular space 412 to the sub-valve chamber 4R, it always passes through the first silencing member 7. The pressing member 93 is formed in a cylindrical shape as a whole, and functions as a pressing portion for pressing the first silencing member 7 as described above. The pressing member 93 has an engagement portion 931 with a reduced inner diameter (reduced diameter) at the upper end, and can engage with the guide boss portion 53 of the sub-valve body 5 at the engagement portion 931. The pressing member 93 is also made of a sliding member such as PPS resin. As a result, when the guide boss portion 53 made of metal (stainless steel), for example, slides against the inner circumferential surface of the pressing member 93 or engages with the engagement portion 931, sliding resistance can be suppressed.

In this embodiment, the first silencing member 7 is fixed inside the cylindrical portion 42 of the main valve body 4 using the fixing member 91A and the fixing member 91B, but only one of them may be used, or the first silencing member 7 may be fixed only by the pressing member 93 without using the fixing members 91A and 91B.

The second silencing member 8 is disposed in the flow path from the auxiliary valve port 41a to the main valve port 23a, that is, disposed downstream of the first silencing member 7 when the first port 21 is the primary side. The second silencing member 8 is a filter formed into a three-dimensional mesh shape by randomly bending a wire member, similar to the first silencing member 7, and may be, for example, a demister. The first silencing member 7 has a higher density than the second silencing member 8. Here, density means mass per volume. As a result, the first silencing member 7 has a higher performance of breaking down air bubbles than the second silencing member 8. In addition, parameters such as the thickness of the wire may be different from each other so that the first silencing member 7 has a higher performance of breaking down air bubbles than the second silencing member 8.

The second silencing member 8 is arranged so as to fit (fill without gaps) inside the cylindrical main valve portion 43, and faces the sub-valve port 41a in the Z direction. This ensures that when the fluid that has passed through the sub-valve port 41a flows into the main valve port 23a, it always passes through the second silencing member 8. The second silencing member 8 may be fixed by crimping it to the lower end of the main valve portion 43, for example, via a ring-shaped member.

Here, the details of the opening and closing operation of the main valve body 4 and the sub-valve body 5 in the motor-operated valve 1 will be described. When the magnet rotor 62 and the rotor shaft 61 rotate due to the driving of the stepping motor 6A, the rotor shaft 61 moves along the Z direction due to the screw feed mechanism 6B between the male thread portion 61a of the rotor shaft 61 and the female thread portion 34a of the guide member 3. As a result, the sub-valve body 5 moves forward and backward in the Z direction to approach or move away from the sub-valve port 41a, and the valve opening degree of the sub-valve port 41a is controlled (small flow control). In addition, the guide boss portion 53 of the sub-valve body 5 engages with the engagement portion 931 of the pressing member 93, and the main valve body 4 moves together with the sub-valve body 5 to approach or move away from the main valve seat 23 (large flow control). As a result, the flow rate of the refrigerant flowing from the first joint pipe 11 to the second joint pipe 12 is controlled. In this embodiment, even when the sub-valve body 5 moves back and forth in the Z direction and is closest to the sub-valve seat portion having the sub-valve port 41a, the sub-valve body 5 does not abut (seat) on the sub-valve seat portion, and a gap is formed between the sub-valve body 5 and the sub-valve seat portion, allowing fluid to pass through the sub-valve port 41a, but the sub-valve body 5 may be configured to seat on the sub-valve seat portion.

A male-threaded guide groove 34b is formed on the outer circumferential surface of the stopper portion 34 of the guide member 3, and a slider 63 is provided in this guide groove 34b. The slider 63 abuts against the magnet rotor 62, and rotates and moves up and down along the guide groove 34b as the magnet rotor 62 rotates. The slider 63 abuts against the upper or lower end of the guide groove 34b, thereby forming a stopper mechanism 6C that restricts the rotation of the magnet rotor 62. The lowermost and uppermost positions of the rotor shaft 61 and magnet rotor 62 are restricted by this stopper mechanism 6C.

Here, the flow of the fluid in the motor-operated valve 1 during low flow control will be described. First, the fluid flows from the first port 21 into the main valve chamber 2R. This fluid may contain air bubbles and become a gas-liquid mixed state, and the following description will assume that the fluid contains air bubbles. The fluid that flows into the main valve chamber 2R flows into the auxiliary valve chamber 4R through the communication passage 421. At this time, the fluid that passes through the communication passage 421 circulates in the annular space 412, and then passes through the communication portion 92B of the fixed member 91B, the first sound-deadening member 7, and the communication portion 92A of the fixed member 91A to reach the auxiliary valve chamber 4R. When the fluid passes through the communication passage 421 toward the annular space 412, the flow direction is along the XY plane. On the other hand, when the fluid passes from the annular space 412 toward the first sound-deadening member 7, the flow direction is along the Z direction. That is, the flow direction is bent at a substantially right angle, and the flow speed is reduced.

As described above, the fluid passes through the first silencing member 7, which breaks down the air bubbles. The fluid then passes through the auxiliary valve port 41a, where the flow is narrowed, and then passes through the second silencing member 8 toward the main valve port 23a. At this time, because the second silencing member 8 has a lower density than the first silencing member 7, the fluid is less likely to stagnate in the second silencing member 8.

When a fluid passes through (flows out of) the auxiliary valve port 41a, the pressure is suddenly reduced, which tends to cause the fluid to contain bubbles of various sizes and to form a jet that flows out of the auxiliary valve port. Therefore, if the first silencing member 7 and the second silencing member 8 have the same bubble breaking performance (e.g., the same density), or if the second silencing member 8 has a higher bubble breaking performance (e.g., a higher density) than the first silencing member 7, the fluid that has passed through the auxiliary valve port 41a has difficulty passing through the second silencing member, and some of the fluid tends to stagnate, making the fluid more unstable.

According to the above embodiment, the first sound absorbing member 7 arranged in the flow path from the communication passage 421 to the auxiliary valve port 41a has a higher density than the second sound absorbing member 8 arranged in the flow path from the auxiliary valve port 41a to the main valve port 23a, and the first sound absorbing member 7 is used to sufficiently break down the bubbles before the fluid flows into the auxiliary valve port 41a, thereby reducing noise. The fluid that flows out of the auxiliary valve port 41a passes through the low-density second sound absorbing member 8, making it difficult for the fluid to stagnate when passing through the second sound absorbing member 8. This stabilizes the flow of the fluid and further reduces noise. In this case, in a configuration in which only the high-density first sound absorbing member is provided and the second sound absorbing member is not provided, noise is generated due to the fluid being suddenly decompressed at the auxiliary valve port. Compared to such a configuration, in this embodiment, the flow of the fluid that has become unstable after passing through the auxiliary valve port is stabilized, thereby sufficiently reducing noise.

In addition, the annular space 412 is formed between the communication passage 421 and the first silencing member 7, so that the speed of the fluid can be reduced before it reaches the first silencing member 7.

In addition, by forming multiple communication passages 421, it is possible to reduce bias in the fluid flow rate in the circumferential direction compared to a configuration in which fluid is introduced into the sub-valve chamber 4R through a single communication passage.

In addition, because the annular space 412 and the first silencing member 7 are aligned in the Z direction, the extension direction of the communication passage 421 intersects with the direction from the annular space 412 toward the first silencing member 7, and the speed of the fluid can be reduced before it reaches the first silencing member 7.

In addition, the first sound-absorbing member 7 and the second sound-absorbing member 8 have linear members that are randomly bent, so that the passages through which the fluid can pass have various sizes of passable area. Therefore, even if the fluid contains bubbles of various sizes, the bubbles can be easily broken down into fine bubbles.

The present invention is not limited to the above embodiment, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. For example, in the above embodiment, multiple communication passages 421 are formed at equal intervals, but the present invention is not limited to such a configuration. In other words, multiple communication passages may be arranged at different intervals from each other, or only one communication passage may be formed.

In addition, in the above embodiment, the annular space 412 and the first sound-absorbing member 7 are aligned in the Z direction, but the annular space and the first sound-absorbing member may be aligned, for example, along the extension direction of the communication passage.

In addition, in the above embodiment, an annular space 412 is formed between the communication passage 421 and the first silencing member 7, but a configuration in which no annular space is formed and the fluid flows directly from the communication passage to the first silencing member may also be used. With such a configuration, it is easy to reduce the size of the main valve body.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes design changes that do not deviate from the gist of the present invention.

1...motor valve, 2...valve housing, 23a...main valve port, 2R...main valve chamber, 4...main valve body, 41a...auxiliary valve port, 412...annular space, 42...cylindrical portion, 421...communicating passage, 4R...auxiliary valve chamber, 5...auxiliary valve body, 6...drive portion, 7...first sound-absorbing member, 8...second sound-absorbing member

Claims (6)

An electrically operated valve comprising: a valve housing; a main valve body for changing an opening degree of a main valve port of a main valve chamber provided in the valve housing; a sub-valve body for changing an opening degree of a sub-valve port of a sub-valve chamber provided in the main valve body; and a drive section for driving the sub-valve body to advance and retreat in an axial direction, wherein a communication passage is formed to communicate between the main valve chamber and the sub-valve chamber,
a first sound- absorbing member disposed in a flow passage from the communication passage to the auxiliary valve port;
a second sound- absorbing member disposed in a flow path from the auxiliary valve port to the main valve port,
The first silencing member and the second silencing member are formed so as to subdivide a flow passage, and the first silencing member has a higher density than the second silencing member. The communication passage is formed in a side surface of the cylindrical portion of the main valve body,
2. The motor-operated valve according to claim 1, wherein an annular space is formed along the cylindrical portion between the communication passage and the first silencer member. The motor-operated valve according to claim 2, characterized in that a plurality of communication passages communicating with the annular space are formed on the side surface of the cylindrical portion. The motor-operated valve according to claim 2 or 3, characterized in that the annular space and the first silencing member are arranged side by side in the axial direction of the annular space. The motor-operated valve according to any one of claims 1 to 4, characterized in that the first sound-absorbing member and the second sound-absorbing member are filters formed in a three-dimensional mesh shape. The motor-operated valve according to claim 5, characterized in that the first and second sound-absorbing members are formed into a three-dimensional mesh shape by randomly bending linear members.

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