JP4265347B2 - Electric expansion valve and refrigeration system - Google Patents

Description

  The present invention relates to a decrease in refrigerant passing sound of an electric expansion valve used in a refrigeration apparatus such as an air conditioner.

FIG. 29 shows a basic structure of an electric expansion valve driven by a stepping motor used in a conventional refrigeration apparatus.
As shown in this figure, in the conventional electric expansion valve, the valve body 101 is divided into two vertically by a partition wall 102, the upper part of the partition wall 102 is a rotor chamber 112 that houses the rotor 111 of the stepping motor 110, and the lower part is the valve The room 120 is used. The stator 113 of the stepping motor 110 is attached to the outside of the rotor chamber 112.
One end of a valve stem 121 is fixed to the rotor 111. Therefore, the valve stem 121 rotates together with the rotor 111 by driving the stepping motor 110.

Further, the valve stem 121 is screwed into a threaded portion 122 formed in the partition wall 102 at an intermediate portion. Therefore, in the valve stem 121, the rotational motion of the valve stem 121 is converted into the axial motion at the screw portion 122.
The tip of the valve rod 121 is formed as a needle valve portion 123.
One refrigerant inlet / outlet pipe section 131 is connected to the side wall of the valve chamber 120. Below the valve chamber 120, a valve seat forming wall 125 having a valve seat 124 formed in the center is provided. The other refrigerant outlet / inlet piping portion 132 communicating with the valve seat 124 is connected to the lower surface of the valve seat forming wall 125.

The electric expansion valve configured as described above drives the stepping motor 110 and controls the rotation angle thereof, thereby moving the needle valve portion 123 forward and backward with respect to the valve seat 124, so that the valve body and the valve seat are moved back and forth. The refrigerant passage area of the throttle portion formed is changed, and the amount of pressure reduction (valve opening) is adjusted by the change of the refrigerant passage area.
Therefore, in the conventional electric expansion valve, the length of the throttle portion is extremely short, and in order to obtain a predetermined amount of decompression, the refrigerant passage area of the throttle portion must be reduced. It had to be extremely fast.

Further, the refrigerant passing sound in the electric expansion valve has a relationship that the energy that is converted into sound energy increases as the refrigerant passing speed of the throttle portion increases, and the refrigerant passing sound increases.
In a refrigeration apparatus such as an air conditioner, generally, due to changes in installation conditions and operating conditions, bubbles are generated in the liquid pipe to the inlet of the expansion valve to form a two-phase refrigerant flow, and the bubbles in the two-phase refrigerant flow May grow to become a slag flow or a plug flow in which large bubbles are intermittently present in the refrigerant flow. In addition, when such a slag flow or plug flow occurs, discontinuous pressure fluctuations occur due to the speed difference between the liquid refrigerant passing through the throttle and the gas refrigerant, and as a result, discontinuous pressure expressed as “churturu” or the like. A refrigerant flow noise was generated. Further, the pressure fluctuation due to such a speed difference of the gas-liquid refrigerant is related to increase as the refrigerant passage speed of the throttle portion increases.

Thus, in the conventional electric expansion valve, there was a problem that the refrigerant passing sound was loud because the refrigerant pressure reduction amount was changed only by the passage area of the throttle portion.
It has been proposed that the refrigerant decompression amount is changed by changing the length of the spiral groove that performs the throttle action instead of the passage area of the throttle portion (for example, Patent Documents 1 and 2). However, both of them attempt to displace the valve body with a linear driving force by a solenoid and a magnetic body.

  In the former example, even if the pressure changes, the valve body must be kept at a fixed position.For this reason, it is necessary to control the position of the valve body in order to adjust the pressure reduction amount. In order to counter the force applied to the valve body by the pressure difference of the body, an extremely large driving force may be required.

In the latter example, in order to improve the problem that the large driving force of the former example is required, means such as branching of the refrigerant passage in two directions are taken to cancel the force applied to the valve body. The structure for this is complicated, and the same point as the former is that a complicated position control is necessary to adjust a minute amount of pressure reduction.
Therefore, a practical electric expansion valve that adjusts the amount of pressure reduction by changing the length of the throttle portion with a simple structure and simple control has not yet been developed.
JP-A-8-296928 JP-A-11-287358

  The present invention has been made paying attention to such problems existing in the prior art. The purpose of the electric expansion valve is that the refrigerant decompression amount can be arbitrarily varied by reducing the refrigerant passage noise by making the refrigerant passage length of the throttle part variable without requiring a complicated structure or control. Another object of the present invention is to provide a refrigeration apparatus using this electric expansion valve.

In order to achieve the above object, an electric expansion valve according to the present invention includes a substantially cylindrical casing, two refrigerant flow ports forming a refrigerant inlet / outlet formed in the casing, and one axial end side of the casing. A substantially cylindrical valve body screwed to the inner surface of the housing, a spiral groove formed between the inner surface of the housing and the valve body so as to be positioned between the two refrigerant circulation ports, The rotating motion is converted into a linear motion by screwing between the inner surface of the housing and the valve body so that it is inserted into the housing on the other end side in the axial direction of the body and rotates together with the valve body. A substantially cylindrical driving body that moves with the valve body in the axial direction of the housing is provided, and a stepping motor that rotationally drives the driving body .

  Thereby, when a refrigerant flows in from one refrigerant circulation port, this refrigerant flows into the spiral groove, is depressurized by passing through this spiral groove, and is sent out from the other refrigerant circulation port. In this electric expansion valve, the amount of decompression by the spiral groove can be changed by controlling the rotation angle of the stepping motor and rotating the drive body by a predetermined angle to adjust the valve body to a predetermined position. it can. Furthermore, since the spiral groove serves as the throttle portion, the pressure reducing action portion becomes longer and the refrigerant passage area can be increased as compared with the throttle portion of the conventional electric expansion valve.

The spiral groove inlet portion is opened in a form in which the spiral groove is inclined with respect to the axial direction of the housing, so that the area of the spiral groove inlet portion into which the refrigerant flows from the refrigerant circulation port increases. The pressure fluctuation of the refrigerant at is reduced. Therefore, the kinetic energy of the refrigerant converted into the refrigerant passing sound is reduced, and the refrigerant passing sound is reduced.
In the electric expansion valve configured as described above, the rotational motion of the stepping motor is changed to a linear motion by screwing of the screw portion. Therefore, even if there is a pressure difference between the front and back of the valve body, a large driving force is not required and a complicated There is no need for position control.
If comprised in this way, the structure of an electric expansion valve will be simplified and cost reduction can be aimed at.

Further, in the electric expansion valve, one of the refrigerant flow port is formed on one end face side in the axial direction of the housing, the other refrigerant flow ports that are formed on the side surface of the housing.
With such a configuration, the refrigerant is sent out from one refrigerant flow port through the spiral groove and from the other refrigerant flow port, so that the spiral groove serves as a throttle portion, compared with the throttle portion of the conventional electric expansion valve. In addition, the pressure reducing action part becomes longer, the refrigerant passage area can be increased, and as a result, the refrigerant passage noise can be reduced.

Further, in the electric expansion valve, the refrigerant flow port formed on the side surface of the casing extends in the tangential direction of the substantially cylindrical casing in the transverse section, and the cross-sectional area increases as the distance from the casing increases. that is formed to have a larger wall.
With such a configuration, the refrigerant smoothly passes from the spiral groove to the refrigerant circulation port, or conversely along the spiral direction from the refrigerant circulation port, and the pressure fluctuation of the refrigerant can be reduced.

In the electric expansion valve, in the vicinity of the boundary between the valve body and the drive body and in the vicinity of the end of the spiral groove, the clearance between the valve body and / or the drive body and the inner surface of the housing A sealing member for closing the gap is provided, the other end surface of the substantially cylindrical housing is closed with a sealing wall, a back pressure chamber is provided between the sealing wall and the driving body, and the back A pressure equalizing hole that penetrates the valve body and the drive body in the axial direction may be provided so as to communicate the pressure chamber with one of the refrigerant flow ports.
This ensures that the refrigerant passes through the constricted passage by the spiral groove and is decompressed, that is, the refrigerant leaks from a part of the spiral groove or from behind the valve element without passing through the constricted passage by the spiral groove. It is possible to prevent the refrigerant from flowing into the circulation. And the pressure before and behind a valve body can be made equal, and the drive torque of a drive body can be reduced.

The electric expansion valve according to the present invention includes a substantially cylindrical casing, two refrigerant flow ports formed in the casing and serving as a refrigerant inlet / outlet, and an inner surface of the casing at one end side in the axial direction of the casing. A substantially cylindrical valve body screwed, a spiral groove formed between the inner surface of the housing and the valve body so as to be positioned between the two refrigerant circulation ports, and other axial directions of the housing Rotating motion is converted into linear motion by screwing between the inner surface of the housing and the valve body so that it is inserted into the housing on the end side and rotates integrally with the valve body, and the inside of the housing is the shaft of the housing. A substantially cylindrical driving body that moves with the valve body in the direction, and a stepping motor that rotationally drives the driving body. The substantially cylindrical housing includes a refrigerant circulation port on one end surface side in the axial direction. A cylindrical shape that extends from the flow port to the inside of the casing for a predetermined length, is concentric with the casing, and is smaller than the cylindrical inner diameter of the casing A substantially cylindrical valve body is provided with a refrigerant flow passage, and is screwed into the outer peripheral surface of the cylindrical refrigerant flow passage, and is deeper than the length of the refrigerant flow passage and concentric with the valve body. It has.
  Thereby, when a refrigerant flows in from one refrigerant circulation port, this refrigerant flows into the spiral groove, is depressurized by passing through this spiral groove, and is sent out from the other refrigerant circulation port. In this electric expansion valve, the amount of decompression by the spiral groove can be changed by controlling the rotation angle of the stepping motor and rotating the drive body by a predetermined angle to adjust the valve body to a predetermined position. it can. Furthermore, since the spiral groove serves as the throttle portion, the pressure reducing action portion becomes longer and the refrigerant passage area can be increased as compared with the throttle portion of the conventional electric expansion valve.
  The spiral groove inlet portion is opened in a form in which the spiral groove is inclined with respect to the axial direction of the housing, so that the area of the spiral groove inlet portion into which the refrigerant flows from the refrigerant circulation port increases. The pressure fluctuation of the refrigerant at is reduced. Therefore, the kinetic energy of the refrigerant converted into the refrigerant passing sound is reduced, and the refrigerant passing sound is reduced.
  In the electric expansion valve configured as described above, the rotational motion of the stepping motor is changed to a linear motion by screwing of the screw portion. Therefore, even if there is a pressure difference between the front and back of the valve body, a large driving force is not required and a complicated There is no need for position control.
  Furthermore, the throttle passage when the refrigerant passes through the electric expansion valve can be made longer. As a result, the length of the electric expansion valve itself can be shortened, and the electric expansion valve can be downsized. Is possible. Alternatively, by making the throttle passage longer, a desired refrigerant decompression amount can be secured and the refrigerant passing sound can be reduced.

In the electric expansion valve, the casing has a small-diameter portion and a large-diameter portion, a valve body is screwed into at least a part of the inner surface of the small-diameter portion, and a driving body is inserted into the large-diameter portion. Further, the driving body may include a communication passage that penetrates in the axial direction so as to communicate with the spiral groove on one end side and communicate with the other refrigerant circulation port on the other end side.
Thereby, it becomes a structure suitable for installing in a linear piping path | route, reducing a refrigerant | coolant passage noise.

Further, the casing has a bulging portion at a part of the large diameter portion, and a transmission gear directly connected to the stepping motor is provided in the bulging portion, and the driving body is connected to the stepping motor via the transmission gear. May be configured to be rotatably connected.
  If comprised in this way, the minimum drive rotation angle of a drive body can be made small, and a fine aperture control (flow rate control) can be performed.

Further, the electric expansion valve has a spiral groove formed on either the inner surface of the housing or the outer surface of the valve body, and the spiral groove is formed so that the groove width and / or depth are different in the axial direction. Alternatively, spiral grooves may be formed on the inner surface of the casing and the outer surface of the valve body, and the meshing heights of the spiral grooves may be different.
  With such a configuration, not only an electric expansion valve having a uniform throttle characteristic, but also an electric expansion valve that can reduce refrigerant noise and has a throttle characteristic that matches the characteristics of the refrigeration cycle can be easily produced.
  And you may enlarge the cross-sectional area of the spiral groove of the entrance / exit of a refrigerant | coolant compared with the cross-sectional area of the spiral groove in an intermediate part.

  In addition, the electric expansion valve has a spiral groove formed on the inner side surface of the casing, and secures a gap between the inner surface of the casing and the valve body at the axial tip of the outer side surface of the valve body. A thread portion having a height substantially corresponding to the depth of the spiral groove may be provided.
  With such a configuration, for example, by operating the valve body from fully open to fully closed or vice versa after a predetermined time since the operation of the electric expansion valve is started, the spiral groove formed on the inner surface of the housing is It is possible to scrape off deteriorated oil, shavings such as valve bodies, dust, etc. adhering to the deepest part.

  Alternatively, the inner surface of the housing and the valve body may be formed such that a predetermined minimum screw portion remains at the minimum throttle position.
  This configuration simplifies the mechanism that moves the valve body between the minimum throttle position and the maximum throttle position, compared to a structure in which the valve body is not completely screwed with the inner surface of the housing at the minimum throttle position. can do. By increasing the processing accuracy of the predetermined minimum screwing portion remaining at the minimum throttle position, the refrigerant pressure reduction amount (throttle control) can be reliably controlled, so the processing accuracy of other screwing portions Can be set low, facilitating production.
  Then, the threaded portion between the inner surface of the housing and the valve body is formed so that the predetermined minimum threaded portion remains at the minimum throttle position, and the minimum threaded portion is formed on the inner surface of the housing or the outer surface of the valve body. You may form the bypass groove which bypasses.
  If comprised in this way, the refrigerant | coolant passage resistance in the minimum throttle state can be decreased, and it becomes possible to use for the use which wants to reduce the refrigerant | coolant passage resistance in the fully open state of an electric expansion valve.

  Moreover, in the refrigeration apparatus using each of the electric expansion valves according to the present invention, the operation sound can be made quiet.

As described above, according to the electric expansion valve according to the present invention, since the spiral groove serves as the throttle portion, the refrigerant passage becomes longer and the refrigerant passage area becomes larger than the throttle portion of the conventional electric expansion valve. Can do. In addition, since the spiral groove inlet portion is opened in a form in which the spiral groove is inclined with respect to the axial direction of the housing, the area of the spiral groove inlet portion into which the refrigerant flows from the refrigerant circulation port increases. The pressure fluctuation of the refrigerant at the inlet is alleviated. Therefore, the amount by which the kinetic energy of the refrigerant is converted into the refrigerant passing sound energy is reduced, and the refrigerant passing sound is reduced. Furthermore, the pressure fluctuation of the refrigerant can be reduced, the electric expansion valve can be reduced in size, or the refrigerant passing sound can be reduced.

  Embodiments of an electric expansion valve embodying the present invention will be described below in detail with reference to the drawings.

  The first embodiment will be described in detail with reference to FIGS. FIG. 1 is a sectional view of the electric expansion valve according to the first embodiment of the present invention, and shows a fully closed state. 2 is a II-II cross-sectional view of the driver in FIG. FIG. 3 is a cross-sectional view of the electric expansion valve, showing a fully opened state. FIG. 4 is an enlarged view of a threaded portion between the inner surface of the casing and the valve body of the electric expansion valve.

As shown in FIG. 1, the electric expansion valve according to the first embodiment includes a substantially cylindrical housing 1 having a small diameter portion 1a and a large diameter portion 1b. Refrigerant circulation ports 1c and 1d are formed on the end surface on the small diameter portion 1a side and the end surface on the large diameter portion 1b side of the housing 1.
As for the small diameter part 1a, the internal thread part 2 is formed in the inner surface. In the housing 1, a substantially cylindrical valve body 3 that is screwed into the female screw portion 2 is accommodated. In this screwing, the female screw portion 2 and the male screw portion 4 of the valve body 3 are screwed together. Further, as can be seen from FIG. 4, the threaded portion between the female screw portion 2 and the male screw portion 4 is formed such that the inclination angle of the mountain of the male screw portion 4 is sharp with respect to the inclination angle of the valley of the female screw portion 2. Thus, a spiral groove 5 is formed between the female screw portion 2 and the male screw portion 4.

Since the end portion of the spiral groove 5 is opened in the housing 1 between the female screw portion 2 and the male screw portion 4, the opening portion is not perpendicular to the axial direction of the housing 1, but is inclined. Become. For this reason, the opening area of the end portion of the spiral groove 5 is larger than when the opening portion opens at a right angle. In addition, the spiral groove 5 opens this end opening in the housing 1 and communicates with the one refrigerant circulation port 1 c through the housing 1.
In the large-diameter portion 1b, a stator 7 that constitutes the stepping motor 6 is attached to the outside, and a drive body 8 that forms a rotor of the stepping motor 6 is housed inside.
The driving body 8 has a substantially cylindrical shape having a larger diameter than the substantially cylindrical valve body 3, and has one end tapered. The end face on the tapered side of the drive body 8 is connected to the end face of the valve body 3 so that both of them can be integrally rotated and moved in the axial direction of the housing 1. A permanent magnet 9 for constituting the rotor of the stepping motor 6 is attached to the outer peripheral surface of the drive body 8 on the surface portion of the drive body 8.

  The drive body 8 is provided with a plurality of skew holes 10 at equal intervals from the tapered end face toward the center. As shown in FIG. 2, these skew holes 10 are defined by partition walls 11 extending in the radial direction from the center. The skew hole 10 forms a fan shape with a tapered end surface and opens into the housing 1 and communicates with the spiral groove 5 through the housing 1. The opposite end of the skew hole 10 communicates with an axial linear hole 12 that opens to the side opposite to the taper surface, and the oblique hole 10 and the linear hole 12 pass through the drive body 8 in the axial direction. A passage 13 is formed. The communication passage 13 communicates with the other refrigerant circulation port 1d through the housing 1.

  The electric expansion valve having the above configuration is configured such that when the stepping motor 6 is driven, the driving body 8 is rotated, and this rotational motion is converted into a linear motion by the screwing mechanism of the female screw portion 2 and the male screw portion 4. It has become. This electric expansion valve moves the valve element 3 to a predetermined position by controlling the rotation angle of the stepping motor 6 to control the screwing length between the female screw portion 2 and the male screw portion 4, and the predetermined length. The spiral groove 5 is obtained to obtain a predetermined refrigerant decompression amount.

FIG. 1 shows the position where the valve body 3 is the maximum throttle, that is, the fully closed position of the electric expansion valve. FIG. 3 shows the position where the valve body 3 is the minimum throttle, that is, the fully open position of the electric expansion valve. Is shown. As can be seen from FIG. 1, the electric expansion valve is configured such that the refrigerant flow port 1c is closed by a tapered protrusion 5a provided on the end surface of the valve body 3 in the fully closed position. As can be clearly seen from FIG. 3, the electric expansion valve is set so that the end face of the driving body 8 is in contact with the right end of the housing 1 and the predetermined minimum spiral groove 5 remains slightly in the fully open position. Yes.
By adopting such a structure, the valve body 3 is set to the minimum throttle position (fully opened position) as compared with the case where the valve body 3 is completely opened from the screwing with the female screw portion 2 at the fully opened position. A mechanism for moving between the maximum throttle position (fully closed position) can be simplified. In addition, since the processing accuracy of the refrigerant pressure reduction (throttle control) can be reliably performed by increasing the processing accuracy of the screwed portion remaining in the fully open position, the processing accuracy of other screwed portions is set low. Can be manufactured easily.

  In the electric expansion valve according to the first embodiment, since the spiral groove 5 serves as a throttle portion, the refrigerant passage becomes longer and the refrigerant passage area can be increased as compared with the throttle portion of the conventional electric expansion valve. Since the inlet of the spiral groove 5 is opened with the spiral groove 5 inclined with respect to the axial direction of the housing 1, the area of the inlet of the spiral groove 5 into which the coolant flows from the coolant circulation port increases. The pressure fluctuation of the refrigerant at the inlet is alleviated. Therefore, the kinetic energy of the refrigerant converted into the refrigerant passing sound is reduced, and the refrigerant passing sound is reduced.

  Further, in the electric expansion valve according to the first embodiment, the driving body 8 constitutes the rotor of the stepping motor 6 and the stator 7 of the stepping motor 6 is attached to the outer peripheral side of the housing 1. Can be simplified and the cost can be reduced. Since the drive body 8 is directly connected to the end face of the valve body 3, the configuration of the electric expansion valve is further simplified, and the cost can be further reduced.

The electric expansion valve of Example 2 is demonstrated based on FIG. FIG. 5 is an enlarged view of a screwed portion between the inner surface of the casing and the valve body of the electric expansion valve according to the second embodiment.
The electric expansion valve according to the second embodiment is obtained by changing the structure of the screwed portion between the inner surface of the small diameter portion 1a of the housing 1 and the valve body 3 according to the first embodiment. More specifically, the inclination angle of the valley of the female screw portion 22 formed on the inner surface of the small diameter portion 1a is matched with the inclination angle of the mountain of the male screw portion 24 of the valve body 3, and The height is made larger than the depth of the valley of the female screw portion 22. With this configuration, a spiral groove 25 is formed between the female screw portion 22 and the male screw portion 24. Other configurations are the same as those of the first embodiment.
Therefore, the second embodiment also has the same effect as that of the first embodiment.

The electric expansion valve of Example 3 is demonstrated based on FIG. FIG. 6 is an enlarged view of a screwed portion between the inner surface of the casing and the valve body of the electric expansion valve according to the third embodiment.
The electric expansion valve of the third embodiment is obtained by changing the structure of the screwed portion between the inner surface of the small diameter portion 1a of the housing 1 and the valve body 3 in the first embodiment. More specifically, the top portion 26a of the female thread portion 26 formed on the inner surface of the small diameter portion 1a is made slightly flat, and the top portion 42 of the male thread portion of the valve body 3 is made flat, The height of the screw thread of the male screw part is made smaller than the depth of the valley of the female screw part 26 of the housing 1 so that they are slightly screwed together.
With this configuration, larger spiral grooves 27a and 27b can be formed between the female screw portion 26 and the male screw portion.
Other configurations are the same as those of the first embodiment. Therefore, the third embodiment has the same effect as that of the first embodiment.

The electric expansion valve of Example 4 is demonstrated based on FIG. FIG. 7 is an enlarged view of a screwed portion between the inner surface of the casing and the valve body of the electric expansion valve according to the fourth embodiment.
The electric expansion valve according to the fourth embodiment is obtained by changing the structure of the screwed portion between the inner surface of the small diameter portion 1a of the housing 1 and the valve body 3 according to the first embodiment. More specifically, the top 28a of the female thread 28 formed on the inner surface of the small-diameter portion 1a is slightly flattened, and the top 43 of the male thread of the valve body 3 is gradually flattened. In other words, the height of the screw thread is gradually changed so that the height of the thread of the male screw portion is smaller than the depth of the valley of the female screw portion 28 so that they are screwed together. With such a configuration, the spiral groove formed when the valve body 3 and the inner surface of the housing 1 are screwed together gradually becomes shallower and deeper as a result. That is, the cross-sectional area of the spiral groove can be changed in the axial direction.

Thereby, if the valve body 3 in the housing | casing 1 is arrange | positioned in a predetermined position, the magnitude | size of the clearance gap between the valve body 3 and the inner surface of the housing | casing 1 can be adjusted. Therefore, it is easy to manufacture an electric expansion valve that can reduce refrigerant noise and that has a throttle characteristic that matches the characteristics of the refrigeration cycle. For example, in the case of FIG. 7, since the cross-sectional area of the spiral groove at the refrigerant inlet / outlet is large, the pressure fluctuation can be reduced, and the necessary throttle amount can be ensured by reducing the cross-sectional area of the spiral groove at the intermediate part.
Other configurations are the same as those of the first embodiment. Therefore, the fourth embodiment also has the same effect as that of the first embodiment.

Example 5 will be described with reference to FIG. FIG. 8 is a cross-sectional view of the electric expansion valve according to the fifth embodiment.
In the fifth embodiment, the structure of the screwed portion between the inner surface of the small-diameter portion 1a of the housing 1 and the valve body 3 in the first embodiment is changed, and the spiral groove 5 in the first embodiment is changed into two passages 35a and 35b. The two passages 35 a and 35 b have a structure corresponding to the spiral groove 5. Other configurations are the same as those of the first embodiment.

  If comprised in this way, even if a pressure fluctuation generate | occur | produces in one channel | path (for example, channel | path 35a), this pressure variation will be attenuate | damped by the refrigerant | coolant which flows through another channel | path (for example, channel | path 35b). Therefore, the refrigerant passing sound in the electric expansion valve can be further reduced.

Example 6 will be described in detail with reference to FIGS. FIG. 9 is a cross-sectional view of an electric expansion valve according to Embodiment 6 of the present invention, and FIG. 10 is a plan view of the distal end portion of the valve body.
In the sixth embodiment, the structure of the threaded portion between the inner surface of the small diameter portion 1a of the housing 1 and the valve body 3 in the first embodiment is changed. More specifically, an internal thread portion 29 is formed on the inner surface of the small diameter portion 1a. In the housing 1, a substantially cylindrical valve body 3 that is screwed into the female screw portion 29 is housed. The screwing is performed by the female screw portion 29 and the male screw portion 44 of the valve body 3. The male threaded portion 44 has a thread 44a that is almost completely abutted against the groove of the female threaded portion 29 only at the distal end of the valve body 3. It only has a thread 42b with a remaining height. That is, the valve body 3 is formed so that the height of the thread 44a of the male screw portion 44 and the depth of the groove of the female screw portion 29 substantially correspond to each other at the tip portion.

  With such a shape, for example, by operating the valve element 3 from fully open to fully closed or vice versa after a predetermined time from the start of the operation of the electric expansion valve, the male thread portion at the tip of the valve element 3 is operated. 44, the thread 44a of the female threaded portion 29 can scrape off deteriorated oil, scrapes of the valve body, dust, and the like.

Further, in order to secure a gap between the inner surface of the housing 1 and the valve body 3 at the tip end portion of the valve body 3, as shown in FIG. It has a notch 44c and is formed so that the thread 44a remains. With such a shape, it is possible to secure a good throttle control without interfering with the passage of the refrigerant while ensuring a configuration for converting the rotary motion of the integral body of the valve body 3 and the drive body 8 into a linear motion. . Moreover, the contact area of the valve body 3 and the inner surface of the housing 1 at the screwing portion can be reduced, and a linear motion can be realized with a smaller rotational force.
Other configurations are the same as those of the first embodiment. Therefore, this embodiment also has the same effect as that of the first embodiment.

The electric expansion valve of Example 7 is demonstrated based on FIG. FIG. 11 is an enlarged view of a screwed portion between the inner surface of the casing and the valve body of the electric expansion valve according to the embodiment 74.
The electric expansion valve according to the seventh embodiment is obtained by changing the structure of the screwed portion between the inner surface of the small diameter portion 1a of the housing 1 and the valve body 3 according to the sixth embodiment. More specifically, as shown in FIG. 9, while leaving the thread 44 a of the male screw portion 44 for two rounds at the distal end portion of the valve body 3, the male screw portion 44 d of the other valve body 3 is left. The screw thread is eliminated, and both are screwed only at the tip of the valve body 3. By comprising in this way, the resistance at the time of rotation of the valve body 3 can be reduced, and a rotational motion can be converted into a linear motion with a smaller force.
Other configurations are the same as those of the sixth embodiment. Therefore, the seventh embodiment has the same effect as that of the sixth embodiment.

The electric expansion valve of Example 8 will be described with reference to FIG. FIG. 12 is an enlarged view of a threaded portion between the inner surface of the housing and the valve body of the electric expansion valve according to the eighth embodiment.
The electric expansion valve according to the eighth embodiment is obtained by changing the structure of the screwed portion between the inner surface of the small diameter portion 1a of the housing 1 and the valve body 3 according to the sixth embodiment. More specifically, the top 45 of the thread of the male thread portion of the valve body 3 is flattened, and further, the small diameter portion 1a in the vicinity of the boundary between the small diameter portion 1a and the large diameter portion (not shown) of the housing 1 is formed. Only on the inner surface, two female thread portions (not shown) are left, and both are screwed only on the inner surface of the small diameter portion 1a in the vicinity of the boundary between the small diameter portion 1a and the large diameter portion 1b. . By comprising in this way, the resistance at the time of rotation of the valve body 3 can be reduced, and a rotational motion can be converted into a linear motion with a small force.

  Other configurations are the same as those of the first embodiment. Therefore, the fifth embodiment has the same effect as that of the first embodiment.

Example 9 will be described with reference to FIG. FIG. 13 is a cross-sectional view of the electric expansion valve according to the ninth embodiment and shows a fully opened state.
In the ninth embodiment, similarly to the first embodiment, the screwed portion between the inner surface of the housing 1 and the valve body 3 is formed so that a predetermined minimum screwed portion remains at the minimum throttle position, and the outer surface of the valve body 3 is formed. A bypass groove 41 that bypasses the minimum screwing portion is formed. Other configurations are the same as those of the first embodiment.

  With this configuration, it is possible to reduce the refrigerant passage resistance in the minimum throttle state, that is, in the fully opened state, so that it can be used for applications where it is desired to reduce the refrigerant passage resistance in the fully opened state of the electric expansion valve.

  Example 10 will be described with reference to FIGS. FIG. 14 is a cross-sectional view of the electric expansion valve according to the tenth embodiment, and shows a state where the valve body is between the vicinity of the minimum throttle position and the maximum throttle position. FIG. 15 is a cross-sectional view of the electric expansion valve, showing a state where the valve body is at the minimum throttle position. FIG. 16 is a view of the auxiliary valve body in the electric expansion valve as viewed from the lateral direction perpendicular to the axis of the housing. FIG. 17 is a view of the auxiliary valve body in the electric expansion valve as viewed from the axial direction of the housing. FIG. 18 is a perspective view of a push rod in the electric expansion valve.

In the tenth embodiment, the valve body 3 and the driving body 8 are integrally formed in the first embodiment, and an auxiliary refrigerant passage that can be opened when the valve is fully opened is provided in the shaft center portion of the integrally formed product.
That is, in this embodiment, a sub refrigerant passage 51 that penetrates the valve body 3 and the drive body 8 in the axial direction is formed. An auxiliary valve body 52 is accommodated in the auxiliary refrigerant passage 51 so as to be movable in the axial direction by the refrigerant pressure, and valve seats 53 and 54 are formed at both ends of the auxiliary refrigerant passage 51. Further, a push rod 55 as shown in FIG. 18 is provided at the right end (end on the refrigerant flow port 1d side) in the large-diameter portion 1b of the housing 1. In this embodiment, a communication passage 57 corresponding to the communication passage 13 in the first embodiment is provided as a plurality of linear holes around the sub refrigerant passage 51.

  As shown in FIG. 16 and FIG. 17, the auxiliary valve body 52 has a cylindrical shape as a basic shape, and is formed in a valve portion 52a having both ends conically sharpened. In addition, the auxiliary valve body 52 has plate-like portions 52b protruding from four positions that divide the circumference of the cylindrical body into four equal parts. The end surface 52 c of the plate-like portion 52 b is formed so as to contact the inner surface of the sub refrigerant passage 51. Therefore, the auxiliary valve body 52 can move in the sub refrigerant passage 51 in any direction by the flow of the refrigerant. When the auxiliary valve body 52 is pressed against the valve seats 53 and 54 at either end by the refrigerant pressure, the auxiliary refrigerant passage 51 is closed by the valve portion 52a.

  As shown in FIG. 18, there are a plurality of push rods 55 in the disk-like portion 55a (four in this case) so that the rod-like portion 55b is suspended from the disk-like portion 55a and the refrigerant can pass through the disk-like portion 55a. ) Fan-shaped through-holes 55c are provided. The push rod 55 prevents the auxiliary valve body 52 from coming into contact with the valve seat 54 and closing the auxiliary refrigerant passage 51 when the valve body 3 is fully open. This prevents the auxiliary valve body 52 from coming into contact with the valve seat 54.

  Therefore, according to this electric expansion valve, when the valve body 3 is between the vicinity of the minimum throttle position and the maximum throttle position, the auxiliary valve body 52 is pressed against the valve seats 53 and 54 by the refrigerant pressure, and the auxiliary refrigerant passage 51 is pressed. Therefore, the refrigerant is depressurized by the spiral groove 5 (see the refrigerant flow indicated by the solid line arrow in FIG. 14). Further, when the valve body 3 is at or near the minimum throttle position and the refrigerant flows from the refrigerant flow port 1c toward 1d, the auxiliary valve body 52 is pushed toward the valve seat 54 by the refrigerant pressure. The push rod 55 prevents contact with the valve seat 54. Therefore, when the valve body 3 is at or near the minimum throttle position, the valve body 3 is fully opened, and the refrigerant can freely flow through the sub refrigerant passage 51 in the fully open state of the valve body 3.

  Since Example 10 is configured as described above, when the valve body is fully opened, it can be circulated through the spiral groove 5 and the wide sub refrigerant passage 51 in the housing 1 (indicated by the solid line arrow in FIG. 15). (Refer to the refrigerant flow). Therefore, it is possible to provide a suitable electric expansion valve when a state where the refrigerant passage resistance is particularly small in one direction is required.

  With this configuration, it is possible to reduce the refrigerant passage resistance in the minimum throttle state in one direction only, that is, in the fully opened state, so in one refrigerant flow direction, the refrigerant passage resistance is controlled linearly from fully closed to fully opened. However, it can be used for applications that require a state in which the refrigerant passage resistance is particularly small in the reverse direction of the refrigerant flow.

Example 11 will be described with reference to FIGS. FIG. 19 is a cross-sectional view of the electric expansion valve according to the eleventh embodiment. 20 is a cross-sectional view taken along line AA ′ of FIG.
In the eleventh embodiment, the length of the throttle passage is increased in the first embodiment.
In other words, in this embodiment, the substantially cylindrical casing 31 includes a coolant circulation port 31c on one end surface side in the axial direction, and extends in a predetermined length from the coolant circulation port 31c to the inside of the casing 31. The refrigerant flow passage 32 is formed. The refrigerant flow passage 32 is concentric with the substantially cylindrical casing 31 and is smaller than the cylindrical inner diameter of the casing 31 and is formed with a length extending from the small diameter portion 31 a to the large diameter portion 31 b of the casing 31.

The columnar valve body 33 is provided with a hole 33 a that is concentric with the cylinder and deeper than the length of the refrigerant flow passage 32. A protrusion 33c is formed on the bottom of the hole 33a (the other end surface of the hole of the valve body 33).
The hole 33a of the substantially cylindrical valve body 33 is screwed to the outer peripheral surface of the cylindrical refrigerant flow passage 32 (the surface on the inner side of the housing 31). The screwing is performed by a female screw portion 46 formed on the inner side surface of the housing 31 and a male screw portion 47 of the valve body 33, and further, the outer surface of the cylindrical refrigerant flow passage 32 (inside the housing 31). The female screw portion 46 formed on the side) and the male screw portion 47 formed on the inner surface of the hole of the valve body 33 are also performed. The male threaded portion 47 has a thread 47a that substantially corresponds to the depth of the spiral groove of the female threaded portion 46 only at the distal end portion of the valve body 33. Is not formed. Further, as shown in FIG. 20, a notch 34 is formed at one end of the valve body 33 so as to leave a part in the circumferential direction of the thread 47a.

  In the electric expansion valve of this embodiment, as indicated by the arrow in FIG. 19, the refrigerant passes through the electric expansion valve, so that the passage in the throttle portion is longer than the electric expansion valve of the first embodiment. can do. As a result, the length of the electric expansion valve itself can be shortened, and the electric expansion valve can be downsized.

Further, by having the protrusion 33 c formed at the bottom of the hole 33 a of the valve body 33, when the valve body 33 approaches one end of the housing 31, the protrusion 33 c passes through the refrigerant flow path 32. It can be reliably closed and the electric expansion valve can be fully closed.
Furthermore, by leaving a part of the thread 47a at the tip of the valve body 33, while ensuring a configuration for converting the rotational motion of the integral body of the valve body 33 and the drive body 8 into a linear motion, the passage of the refrigerant It is possible to remove dust and the like adhering to the female screw portion 46 while ensuring good aperture control without disturbing the above.

Further, even when the front end portion of the valve body 33 is screwed with the casing 31 without any gap between them, the valve body is formed by forming the notch portion 34 at the front end portion of the valve body 33. A gap can be secured between the housing 33 and the housing 31, and the refrigerant flow is not hindered.
In other configurations, due to the configuration of the hole 33a formed in the valve body 33, the skew hole 10a and the linear hole 12a formed in the drive body 8a are small, and are biased toward the outer peripheral portion of the drive body 8a. Except for the formed structure, the sixth embodiment is the same as the sixth embodiment. Therefore, it has the same effect as that of the sixth embodiment.

  The twelfth embodiment will be described in detail with reference to FIGS. FIG. 21 is a cross-sectional view of the electric expansion valve according to the twelfth embodiment of the present invention, and shows the position where the valve element is at the maximum throttle, that is, the fully closed state of the electric expansion valve. FIG. 22 shows a cross-sectional view of the refrigerant circulation port.

As shown in FIG. 21, the electric expansion valve according to the twelfth embodiment has a substantially cylindrical casing 48. A refrigerant circulation port 48 a is formed on one end face of the casing 48, and a refrigerant circulation port 48 b is formed on the side surface.
A female screw portion 49 is formed on the inner surface of one side of the casing 48. In the housing 48, a substantially cylindrical valve body 58 that is screwed into the female screw portion 49 is housed. The screwing is performed only at the tip of the valve body 58 as in the sixth embodiment.

Further, the screwed portion between the female screw portion 49 and the tip of the valve body 58 is configured in the same manner as in the sixth embodiment, so that a spiral groove 48c is formed between the female screw portion 49 and the valve body 58. The The end of the spiral groove 48c is opened in the housing 48 between the female screw portion 49 and the valve body 58, and communicates with the refrigerant flow ports 48a and 48b, respectively.
As shown in FIG. 22, the refrigerant circulation port 48 b formed on the side surface of the casing 48 extends in the tangential direction of the substantially cylindrical casing 48 and cuts away as the distance from the casing 48 increases. It is formed so as to have a wall portion 48d whose area increases.

  With such a configuration, the refrigerant that has circulated along the spiral groove 48c passes through the refrigerant circulation port 48b smoothly along the spiral direction, and the pressure fluctuation of the refrigerant can be reduced.

Further, on the other side of the casing 48, a stator 7 constituting the stepping motor 6 is attached to the outside, and a driving body 8b forming a rotor of the stepping motor 6 is housed inside.
The driving body 8b has a substantially cylindrical shape, and has a substantially cylindrical shape equivalent to the valve body 58 including the screw thread at the tip. And the end surface of this drive body 8b is connected with the end surface of the valve body 58, and both are comprised so that rotation and movement to the axial direction of the housing | casing 48 are possible. A permanent magnet 9 for constituting the rotor of the stepping motor 6 is attached to the outer peripheral surface of the driving body 8b.

  In this embodiment, since the spiral groove 48c serves as a throttle portion, the same effect as that of the first embodiment is obtained. Moreover, since it has the rotation mechanism similar to Example 1, it has the same effect as Example 1. Furthermore, since the male thread portion of the valve body 58 has the same configuration as that of the sixth embodiment, the same effect as that of the sixth embodiment is obtained.

The thirteenth embodiment will be described in detail with reference to FIG. FIG. 23 is a cross-sectional view of the electric expansion valve according to Embodiment 13 of the present invention.
In this embodiment, a pressure equalizing hole 58a is formed in the driving body 8b from the valve body 58 so as to communicate with one of the refrigerant circulation ports 48a, and a boundary portion between the valve body 58 and the driving body 8b. The sealing member 59 for sealing the clearance gap between the inner surface of the housing | casing 48 and the valve body 58 is provided. For this seal member, a known material is used as a seal member such as an O-ring, a piston ring, or a resin.

As a result, the refrigerant flowing from the pressure equalizing hole 58a to the driving body 8b side does not flow through the throttle passage and flows from the back of the valve body 58 to the refrigerant circulation port 48b (see the arrow in FIG. 23). Can be made equal, and the driving torque of the driving body can be reduced.
The other configuration is the same as that of the twelfth embodiment. Therefore, this Example 13 also has the same function and effect as Example 12.

Example 14 will be described in detail with reference to FIG. FIG. 24 is a cross-sectional view of an electric expansion valve according to Embodiment 14 of the present invention.
In this embodiment, the spiral groove is formed only on the inner surface of the casing 48, and the sealing member 59 for sealing the gap between the inner surface of the casing 48 and the valve body 58 is provided with the valve body 58 and the driving body 8b. Is formed in a portion where the contact area between the valve body 58 and the inner surface of the housing 48 is smaller.

  As a result, the contact area between the seal member 59 and the inner surfaces of the valve body 58 and the casing 48 can be reduced, and the resistance caused by the contact can be reduced, compared with the electric expansion valve of the thirteenth embodiment. However, the driving torque of the driving body can be further reduced.

  The other configuration is the same as that of the twelfth embodiment. Therefore, this Example 14 also has the same function and effect as Example 12.

Example 15 will be described with reference to FIG. FIG. 25 is a cross-sectional view of the electric expansion valve according to the fifteenth embodiment and shows a fully closed state.
In the fifteenth embodiment, the driving body is driven by a stepping motor via a transmission gear.

That is, in the fifteenth embodiment, the bulging portion 15 is formed in a part of the large-diameter portion 1b of the housing 1, and the speed change gear 17 directly connected to the stepping motor 16 is provided in the bulging portion 15 for driving. A body 18 is rotatably connected by a stepping motor 16 through the transmission gear 17. The driving body 18 is the same as that of the first embodiment except that a gear that meshes with the transmission gear 17 is formed on the outer surface portion. Other configurations than those described above are the same as those in the first embodiment.
If comprised in this way, the minimum drive rotation angle of the drive body 18 can be made minute, and minute aperture control (flow rate control) can be performed.

(Modification)
In addition, this invention can also be changed and embodied as follows.
(1) In the first to ninth embodiments, the partition wall 11 may be inclined so that the refrigerant flowing into the spiral groove 5 entering from the coolant circulation port Id side is swung in the same direction as the spiral groove 5.

  If formed in this way, even when the refrigerant flows in from the side of the driving body 8, even if the flowing refrigerant is a two-phase refrigerant containing bubbles, the refrigerant flow that flows out of the spiral groove 5, or conversely, the driving body 8. Since the refrigerant flow flowing into the spiral groove 5 from the side can be rectified, the pressure fluctuation of the refrigerant in the spiral groove 5 is alleviated and the refrigerant passing sound is reduced.

  (2) Although the bypass groove 41 is provided on the outer surface of the valve body 3 in the ninth embodiment, it may be provided on the female screw portion 2 on the inner surface side of the small diameter portion 1a of the housing 1 instead.

  (3) The configurations of the first to fourteenth embodiments can also be applied to the electric expansion valve in which the driving body 18 is driven by the stepping motor 16 via the transmission gear as in the fifteenth embodiment.

  (4) The configuration of the fourth embodiment can be applied to all the electric expansion valves of the first to fifteenth embodiments. Moreover, in Example 4, it changes so that the top part 43 of the thread of the male thread part of the valve body 3 may be gradually raised and lowered from one end of the valve body 3 to the other end. The valve body 3 may be configured to gradually increase or decrease from one end to the other end. Furthermore, when a thread is not formed on either the valve body 3 or the small diameter portion 1a of the housing 1 and the surface thereof is flat (for example, FIG. 11 or FIG. 12), the width of the thread itself or You may change the depth. In the same manner, the depth of the spiral groove itself can be gradually changed or arbitrarily changed. With such a configuration, an arbitrary aperture characteristic can be obtained.

  (5) The configuration of the male thread portion 44 of the valve body 3 according to the sixth embodiment can be applied to all the first to fifteenth embodiments. With such a configuration, it is possible to remove deteriorated oil, shavings such as valve bodies, dust, and the like attached to the female screw portion of the housing.

  (6) The structure of the valve body 33 and the housing | casing 31 in Example 11 is applicable to Examples 1-9. With such a configuration, the length of the electric expansion valve itself can be shortened, and downsizing can be achieved.

(7) The configuration of the refrigerant flow port 48b of the twelfth embodiment can be applied to embodiments other than the tenth embodiment. The refrigerant circulation port 48b may have a circular cross-sectional area such as a cone, but may be a polygon such as a quadrangle, an ellipse, or the like.
(8) The shapes of the thread and the spiral groove of the valve body or the case in Examples 1 to 3 (FIGS. 4 to 6) and Examples 7 and 8 (FIGS. 11 and 12) are all implementations of the present invention. Can be applied to examples.

(Application examples)
An application example of the electric expansion valve configured as described above will be briefly described.
The electric expansion valve having the above-described configuration can be used for any refrigeration apparatus, but is particularly effective when used for an indoor unit in which the refrigerant passing sound in the electric expansion valve is easily regarded as a problem.

Application example 1.
Application example 1 will be described with reference to FIG.
Application Example 1 is an example applied to a heat pump type multi-room separated air conditioner, and FIG. 26 shows a refrigerant circuit thereof.
In the air conditioner of Application Example 1, as shown in this figure, a plurality of indoor units 1D are connected to an outdoor unit 1A using connecting pipes 1B and 1C.

  As shown in FIG. 26, the outdoor unit 1A accommodates a compressor 61, an outdoor coil 62, an outdoor fan 63, a conventionally known electric expansion valve 64 dedicated to heating, a four-way switching valve 65, and the like. Connected by. The indoor unit 1D houses an indoor coil 66, an indoor fan 67, an electric expansion valve 68 according to the present invention, and the like, and is connected by a refrigerant pipe.

During the cooling operation, the four-way switching valve 65 is set to the switching position indicated by the solid line, the electric expansion valve 64 is fully opened, and the electric expansion valve 68 is also set so that the degree of superheat at the outlet of the indoor coil 66 becomes a predetermined value. By adjusting the amount of refrigerant decompression, the refrigerant flows as shown by the solid line arrow, and cooling is performed by causing the indoor coil 66 to act as an evaporator.
Further, during the heating operation, the four-way switching valve 65 is set to the switching position indicated by the broken line in the figure, and the electric expansion valve 68 is used to slightly reduce the pressure. The valve 64 also adjusts the refrigerant pressure reduction amount so that the refrigerant flows as shown by a broken line arrow, and the indoor coil 66 acts as a condenser to perform heating.

  In such a heat pump type multi-chamber separated air conditioner, the operating conditions and installation conditions change greatly, and the slag flow and the plug flow easily flow through the electric expansion valve 68, and the refrigerant passing sound tends to be a problem. By using the valve, the refrigerant passing sound can be reduced.

  In such a multi-chamber separated air conditioner, since the compressor oil retained in the refrigerant circuit is returned to the compressor 61, the rotation of the compressor 61 is increased and the electric expansion valve 68 in the same circuit as in the cooling operation. The oil return operation for obtaining a large flow rate with the valve fully open may be performed. However, when such an oil return operation is assumed, it is particularly preferable to use the electric expansion valve 68 of Example 10. That is, the linearity of the refrigerant flow rate control of the electric expansion valve 68 is not impaired during the cooling operation, but the refrigerant flow resistance can be made particularly small during the oil return operation where the operation is performed in the same refrigerant circuit.

Application Example 2
Application example 2 will be described with reference to FIG.
The application example 2 is an example applied to a separation type air conditioner capable of cooling, heating and dehumidifying operation, and FIG. 27 shows a refrigerant circuit thereof.

  In the air conditioner of Application Example 2, as shown in this figure, the indoor unit 2D is connected to the outdoor unit 2A by connecting pipes 2B and 2C.

As shown in FIG. 27, the outdoor unit 2A houses a compressor 71, an outdoor coil 72, an outdoor fan 73, a conventionally known electric expansion valve 74, a four-way switching valve 75, and the like, which are connected by refrigerant piping. Has been. The indoor unit 2D houses a first indoor coil 76, a second indoor coil 77, an indoor fan 78, an electric expansion valve 79 according to the present invention, and the like.
During the cooling operation, the four-way switching valve 65 is set to the switching position indicated by the solid line in the figure, the electric expansion valve 79 is fully opened, and the electric expansion valve 74 is electrically driven so that the degree of superheat at the outlet of the indoor coil 77 becomes a predetermined value. The expansion valve 74 also adjusts the refrigerant depressurization amount to cause the refrigerant to flow as indicated by a solid arrow, and the indoor coils 76 and 77 act as an evaporator to perform cooling.

Further, during the heating operation, the four-way switching valve 75 is set to the switching position indicated by the broken line in the figure, the electric expansion valve 79 is fully opened, and the electric expansion valve 74 is also refrigerated so that the degree of superheat at the outlet of the outdoor coil 72 becomes a predetermined value. By adjusting the amount of decompression, the refrigerant is flown as indicated by broken arrows, and heating is performed by causing the indoor coils 76 and 77 to act as a condenser.
During the dehumidifying operation, the four-way switching valve 75 is set to the switching position indicated by the solid line in the figure, the electric expansion valve 74 is fully opened, and the electric expansion valve 79 is also reduced in refrigerant pressure so that the degree of superheat at the outlet of the indoor coil 77 becomes a predetermined value. Is adjusted to flow the refrigerant as indicated by the wavy arrow, the indoor coil 76 is used as a reheater (condenser), and the indoor coil 77 is used as an evaporator to perform dehumidification.

  Even in such an air conditioner for cooling, heating and dehumidification, the refrigerant passing sound can be reduced by using the electric expansion valve according to the present invention. Moreover, if the electric expansion valve of the above-mentioned Example 9 or Example 10 is used, the refrigerant passage resistance when the electric expansion valve 79 is fully opened can be reduced.

Application Example 3
Application example 3 is an example applied to a heat pump separation type air conditioner, and FIG. 28 shows a refrigerant circuit thereof.
In the air conditioner of the application example 3, as shown in this figure, a plurality of indoor units 3D are connected to the outdoor unit 3A using connecting pipes 3B and 3C.

As shown in FIG. 28, the outdoor unit 3A contains a compressor 81, an outdoor coil 82, an outdoor fan 83, an electric expansion valve 84 according to the present invention, a four-way switching valve 85, and the like, which are connected by a refrigerant pipe. Has been. The indoor unit 3D contains an indoor coil 86, an indoor fan 87, and the like and is connected by a refrigerant pipe.
During the cooling operation, the four-way switching valve 85 is set to a switching position indicated by a solid line, and the electric expansion valve 84 also adjusts the refrigerant pressure reduction amount so that the degree of superheat at the outlet of the indoor coil 86 becomes a predetermined value. Is flown as indicated by a solid arrow, and the indoor coil 86 is allowed to act as an evaporator for cooling.

Further, during the heating operation, the four-way switching valve 85 is set to the switching position indicated by the broken line in the drawing, and the electric expansion valve 84 also adjusts the refrigerant pressure reduction amount so that the degree of superheat at the outlet of the outdoor coil 82 becomes a predetermined value. Is flown as shown by a broken arrow, and heating is performed by causing the indoor coil 86 to act as a condenser.
As in this application example, it may be used for an electric expansion valve of an outdoor unit. In this case, the operation sound of the outdoor unit can be reduced.

Application Example 4
The application example 4 applies the electric expansion valve of the tenth embodiment to the electric expansion valve 64 dedicated to heating of the outdoor unit 1A of the multi-room separation type air conditioner as in the application example 1 described above. In addition, the refrigerant circuit is the same as the application example 1, and it controls similarly to the application example 1 and performs air conditioning. The following description is based on the assumption that the refrigerant circuit of FIG. 26 is provided.

  As described above, the heating-only electric expansion valve 64 housed in the outdoor unit 1A is fully opened during the cooling operation, and the flow rate control is performed only during the heating operation. The electric expansion valve 64 is similar to the electric expansion valve 84 in the case of the above application example 3 in that it is housed in the outdoor unit, but the flow rate control is required only during the heating operation. It is different in point.

  Therefore, when the electric expansion valve according to the tenth embodiment is used as such an electric expansion valve 64 dedicated to heating, the refrigerant passage resistance when the valve is fully opened during the cooling operation is reduced. Moreover, at the time of the heating operation which requires flow control, flow control can be performed linearly from the state close | similar to a full close to the state close | similar to a full open.

It is sectional drawing of the electric expansion valve which concerns on Example 1 of this invention, Comprising: A fully closed state is shown. It is II-II sectional drawing of the drive body in FIG. It is sectional drawing of the same electric expansion valve, Comprising: A full open state is shown. It is an enlarged view of the screwing part of the housing | casing inner surface and valve body of the same electric expansion valve. It is an enlarged view of the screwing part of the housing | casing inner surface and valve body of the electric expansion valve which concerns on Example 2. FIG. It is an enlarged view of the screwing part of the housing | casing inner surface and valve body of the electric expansion valve which concerns on Example 3. FIG. It is an enlarged view of the screwing part of the housing | casing inner surface and valve body of the electrically driven expansion valve which concerns on Example 4. FIG. It is sectional drawing of the electric expansion valve which concerns on Example 5. FIG. It is sectional drawing of the electric expansion valve which concerns on Example 9. FIG. It is a top view of the valve body front-end | tip part in the electrically driven expansion valve of Example 9. FIG. It is an enlarged view of the screwing part of the housing | casing inner surface and valve body of the electrically driven expansion valve which concerns on Example 7. FIG. It is an enlarged view of the screwing part of the housing | casing inner surface and valve body of the electrically driven expansion valve which concerns on Example 8. FIG. It is sectional drawing of the electric expansion valve which concerns on Example 9, Comprising: A full open state is shown. It is sectional drawing of the electric expansion valve which concerns on Example 10, Comprising: The state when a valve body exists between the minimum throttle position vicinity and the maximum throttle position is shown. It is sectional drawing of the same electric expansion valve, Comprising: A state when a valve body exists in the minimum throttle position is shown. It is the figure which looked at the auxiliary valve body in the same electric expansion valve from the horizontal direction at right angles to the axis | shaft of a housing | casing. It is the figure which looked at the auxiliary valve body in the same electric expansion valve from the axial direction of the housing. It is a perspective view of the push rod in the same electric expansion valve. It is sectional drawing of the electrically driven expansion valve which concerns on Example 11. FIG. It is AA sectional view taken on the line of the valve body in the electrically driven expansion valve of Example 11. FIG. It is sectional drawing of the electrically driven expansion valve which concerns on Example 12, Comprising: A fully closed state is shown. FIG. 22 is a sectional view taken along line B-B in FIG. 21. It is sectional drawing of the electric expansion valve which concerns on Example 13, Comprising: A fully closed state is shown. It is sectional drawing of the electrically driven expansion valve which concerns on Example 14, Comprising: A fully closed state is shown. It is sectional drawing of the electrically driven expansion valve which concerns on Example 15, Comprising: A fully closed state is shown. It is a refrigerant circuit figure which shows the application example 1 of the electrically driven expansion valve which concerns on this invention. It is a refrigerant circuit figure which shows the application example 2 of the electric expansion valve which concerns on this invention. It is a refrigerant circuit figure which shows the application example 3 of the electric expansion valve which concerns on this invention. It is a basic structural diagram of an electric expansion valve driven by a conventional stepping motor.

Explanation of symbols

1, 31, 48 Housing 1a, 31a Small diameter part 1b, 31b Large diameter part 1c, 1d, 31c, 48a, 48b Refrigerant flow port 2, 22, 26, 28, 29, 46, 49 Female thread part 3, 33, 58 Valve body 4, 24, 44, 44d, 47 Male thread portion 5, 25, 27a, 48c Spiral groove 5a Tapered projection 6, 16 Stepping motor 7 Stator 8, 8a, 8b, 18 Driver 9 Permanent magnet 10, 10a Oblique hole 11 Bulkhead 12, 12a Linear hole 13 Communication passage 15 Swelling portion 17 Transmission gear 18 Drive body 26a, 28a, 42, 43, 45 Top portion 32 Refrigerant flow passage 33a Hole portion 33b Recess inside surface 33c Projection Parts 34, 44c Notches 35a, 35b Passage 41 Bypass grooves 42b, 44a, 47a Thread 48d Wall 51 Sub refrigerant passage 52 Auxiliary valve body 52a Valve part 52b Plate-like part 52c End face 53, 54 Valve seat 55 Push rod 55a Disk-like portion 55b Rod-like portion 55c Fan-shaped through hole 57 Communication passage 58a Pressure equalizing hole 59 Seal member 61 Compressors 62, 72, 82 Outdoor coils 63, 73, 83 Outdoor fan 64, 74, 84 Electric expansion valve 65, 75, 85 Four-way switching valve 66, 76, 77, 86 Indoor coil 67, 78, 87 Indoor fan 68, 79 Electric expansion valve 71, 81 Compressor 1A, 2A, 3A Outdoor unit 1B 2B, 3B Connecting piping 1D, 2D, 3D Indoor unit

Claims (10)

A substantially cylindrical casing, two refrigerant circulation ports formed in the casing and forming a refrigerant inlet / outlet, and a substantially cylindrical valve body screwed to the inner surface of the casing at one end side in the axial direction of the casing; A spiral groove formed between the inner surface of the housing and the valve body so as to be positioned between the two refrigerant circulation ports, and the valve is fitted into the housing on the other end side in the axial direction of the housing. In order to rotate integrally with the body, the rotational motion is converted into a linear motion by screwing the inner surface of the housing and the valve body, and moves in the housing along with the valve body in the axial direction of the housing. A driving body and a stepping motor that rotationally drives the driving body ;
One refrigerant flow port is formed on one end surface side in the axial direction of the housing, and the other refrigerant flow port is formed on the side surface of the housing.
The coolant circulation port formed on the side surface of the housing has a wall portion that extends in the tangential direction of the substantially cylindrical housing in its transverse section and has a cross-sectional area that increases as it moves away from the housing. An electric expansion valve formed . In the vicinity of the boundary between the valve body and the drive body and in the vicinity of the end of the spiral groove, a seal member is provided in the clearance between the valve body and / or the drive body and the inner surface of the housing. ,
The other end surface of the substantially cylindrical housing is closed with a sealing wall, and a back pressure chamber is provided between the sealing wall and the driving body. Further, the back pressure chamber and one of the refrigerant circulation ports are provided. The electric expansion valve according to claim 1, wherein a pressure equalizing hole is provided through the valve body and the drive body in the axial direction so as to communicate with each other . A substantially cylindrical casing, two refrigerant circulation ports formed in the casing and forming a refrigerant inlet / outlet, and a substantially cylindrical valve body screwed to the inner surface of the casing at one end side in the axial direction of the casing; A spiral groove formed between the inner surface of the housing and the valve body so as to be positioned between the two refrigerant circulation ports, and the valve is fitted into the housing on the other end side in the axial direction of the housing. In order to rotate integrally with the body, the rotational motion is converted into a linear motion by screwing the inner surface of the housing and the valve body, and moves in the housing along with the valve body in the axial direction of the housing. A driving body and a stepping motor that rotationally drives the driving body;
The substantially cylindrical casing has a refrigerant circulation port on one end surface side in the axial direction, extends from the refrigerant circulation port to the inside of the casing for a predetermined length, is concentric with the casing, and is a cylinder of the casing With a cylindrical refrigerant flow passage smaller than the inner diameter,
The substantially cylindrical valve body is screwed into the outer peripheral surface of the cylindrical refrigerant flow passage, and has a hole deeper than the length of the refrigerant flow passage and concentric with the valve body. . The housing has a small diameter portion and a large diameter portion, and a valve body is screwed into at least a part of the inner surface of the small diameter portion, and a driving body is inserted into the large diameter portion, The drive body includes a communication passage that penetrates in an axial direction so as to communicate with the spiral groove on one end side and communicate with the other refrigerant circulation port on the other end side. electric expansion valve. The casing has a bulging portion in a part in the axial direction, and a transmission gear directly connected to the stepping motor is provided in the bulging portion, and the driving body can be rotated by the stepping motor via the transmission gear. The electric expansion valve according to any one of claims 1 to 4, which is connected . A spiral groove is formed on either the inner surface of the housing or the outer surface of the valve body, and the spiral groove is formed so that the groove width and / or depth is different in the axial direction, or the housing The electrically driven expansion valve according to any one of claims 1 to 5, wherein spiral grooves are formed on the inner surface and the outer surface of the valve body, and the mesh heights of the spiral grooves are different from each other . The electric expansion valve according to claim 6, wherein the cross-sectional area of the spiral groove at the refrigerant inlet / outlet is larger than the cross-sectional area of the spiral groove at the intermediate portion. A spiral groove is formed on the inner side surface of the casing, and the depth of the spiral groove is secured while ensuring a gap between the inner surface of the casing and the valve body at the axial tip of the outer surface of the valve body. The electric expansion valve according to any one of claims 1 to 7, wherein a thread portion having a substantially corresponding height is provided . The screwed portion between the inner surface of the housing and the valve body is formed so that a predetermined minimum screwed portion remains at the minimum throttle position, and bypasses the minimum screwed portion on the inner surface of the housing or the outer surface of the valve body. The electric expansion valve according to any one of claims 1 to 8, wherein a bypass groove is formed .   A refrigeration apparatus using the electric expansion valve according to any one of claims 1 to 9.

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