JP2009275834A - Flow path selector valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow path selector valve which can retain a seating condition of a main valve 3 by a differential pressure between the outside of the main valve 3 and a low pressure passage 31A, which can quickly perform pressure equalization in a high-pressure coolant of the outside of the main valve 3 and a low-pressure coolant in the low-pressure passage 31A, and which can secure the rotary movement of the main valve 3. <P>SOLUTION: A pressure-equalization valve 4 is provided to the main valve 3, and a first communicating hole 34 and a second communicating hole 35 are formed. The first communicating hole 34 connects the low-pressure passage 31A and the top of the main valve 3, and the second communicating hole 35 connects the sub-valve back space 42A and the top of the main valve 3. A sub-sub valve 5 is provided above the main valve 3, and switching between connection and non-connection of the first communicating hole 34 and the second communicating hole 35 is performed by rotating the sub-sub valve 5. The sub-valve back space 42A is brought under high-pressure, and a sub-valve 43 is seated in a sub-valve port 41 in the non-connection state of the first communicating hole 34 and the second communicating hole 35. Then air conditioning operation or heating operation is performed. The sub-valve 43 is separated from the sub-valve port 41 in the connection state of the first communicating hole 34 and the second communicating hole 35. Then pressure equalization is performed in the space of the outside of the main valve 3 and the interior of the low-pressure passage 31A, and the main valve 3 is rotated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flow path switching valve that is used in a heat pump refrigeration cycle or the like and switches a flow path of a refrigerant.

  Conventionally, this type of flow path switching valve is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-148835 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2006-183802 (Patent Document 2). In Patent Document 1, a suction pressure conduction hole (low pressure port), a discharge pressure conduction hole (high pressure port), and two conduction holes (switching port) are formed in a valve body (valve seat), and a suction pressure is formed in a main valve. A communication portion (low pressure passage) that selectively communicates the conduction hole and the two conduction holes, and a pressure equalization hole that communicates the communication portion and the valve chamber are provided. In addition, a sub-valve interlocking with the rotation of the rotor is provided on the main valve. The main valve is pressed against the valve main body (valve seat) by the pressure difference between the pressure outside the main valve, that is, the pressure in the valve chamber and the pressure in the communicating portion, and the seated state is maintained. Further, when switching the refrigerant flow path, the sub-valve is rotated by the motor unit to open the pressure equalizing hole so as to eliminate the differential pressure.

Patent Document 2 obtains a seal pressure that presses the main valve against the valve seat by a differential pressure between the refrigerant pressure outside the main valve in the valve chamber and the refrigerant pressure in the low pressure passage (conduction passage) of the main valve. . And in the thing of this patent document 2, when a main valve exists in a 1st position, a subvalve is rotated and a pressure equalizing hole of a main valve enters into a predetermined angle range, and a low pressure path (conduction path) and pressure control space When the pressure equalizing hole is at a substantially central position within a predetermined angle range, the main valve and the sub valve are connected by the clutch mechanism, and the main valve is rotated by the rotation of the sub valve. Yes. When the sub-valve rotates, the clutch mechanism starts pressure equalization before connecting the sub-valve and the main valve, so that when the clutch mechanism is in a connected state, that is, the main valve starts rotating. The pressure is equalized sufficiently.
JP 2003-148835 A JP 2006-183802 A

  However, in Patent Document 1 or Patent Document 2, the auxiliary valve is rotated by a motor or the like to open and close the pressure equalizing hole of the main valve. A frictional force is generated between the valve and the auxiliary valve can be rotated by the force of a motor, etc., and the pressure equalizing hole with a small opening area can only be opened and closed. There is a problem that it cannot be done quickly.

  The present invention relates to a flow path switching valve configured to maintain a seated state of a main valve by a differential pressure between a refrigerant pressure in a space outside the main valve and a refrigerant pressure in a low-pressure passage of the main valve. Prior to this, it is an object to quickly equalize the pressures of the high-pressure refrigerant around the main valve and the low-pressure refrigerant in the low-pressure path and to ensure the rotation of the main valve.

  The flow path switching valve according to claim 1 accommodates a main valve in a cylindrical valve chamber so as to be rotatable about an axis of the valve chamber, and a low pressure port, a high pressure port, and 2 in a valve seat facing the main valve. One switching port is opened, and the main valve is rotated so that the low pressure port communicates with one switching port and the high pressure port communicates with the other switching port by a low pressure passage formed in the main valve. A flow path switching valve that switches communication destinations of two switching ports, allows refrigerant flowing in from the high pressure port to flow out to one switching port, and flows refrigerant flowing in from the other switching port to the low pressure port, the high pressure port In the flow path switching valve configured to maintain the seated state of the main valve by the differential pressure of the refrigerant between the outside of the main valve leading to the main valve and the low pressure passage of the main valve, the main valve is provided with a pressure equalizing valve, The pressure equalizing valve is connected to the low-pressure path. A valve port, a cylinder communicating with the sub valve port, a sub valve inserted in the cylinder and capable of being seated and separated from the sub valve port, and biasing the sub valve toward the sub valve port side The main valve is formed with a high-pressure passage that connects the side portion of the sub-valve and the cylinder portion to the outside of the side surface of the main valve, and the sub-valve includes the high-pressure passage. A sub-valve passage that connects the passage to the sub-valve back space on the opposite side of the sub-valve port of the sub-valve is formed, and the main valve has a conduction state and a non-conduction state between the sub-valve back space and the low-pressure passage. Switching means is provided for switching between the auxiliary valve back space and the low pressure passage by the switching means, and the auxiliary valve back space is set to a high pressure via the high pressure passage and the auxiliary valve passage. The auxiliary valve is seated on the auxiliary valve port by an urging means, and the outside of the main valve is The seating state of the main valve is maintained by the differential pressure between the space and the low pressure passage, and the auxiliary valve back space and the low pressure passage are brought into conduction by the switching means, and the sub valve back space is made low pressure. Thus, the auxiliary valve is separated from the auxiliary valve port to equalize the space outside the main valve and the low pressure passage, thereby rotating the main valve.

  2. The flow path switching valve according to claim 1, wherein when the main valve is seated on the valve seat, the switching means is in a non-conducting state between the auxiliary valve back space and the low pressure path, and the auxiliary valve back space includes the high pressure path and the auxiliary valve path. It becomes a high pressure by the refrigerant flowing in through. As a result, the sub valve port is closed by the sub valve urged by the urging means, and the seating state of the main valve is maintained by the differential pressure between the refrigerant pressure outside the main valve and the refrigerant pressure in the low pressure passage. . When the refrigerant flow path is switched, the auxiliary valve back space is connected to the low pressure path by the switching means. As a result, the sub valve back space becomes a low pressure, and the sub valve is separated from the sub valve port by the refrigerant pressure from the high pressure path that conducts to the outside of the main valve, and the low pressure path is conducted to the high pressure path by the sub valve port. The outside of the valve and the low pressure path are equalized.

  The flow path switching valve according to claim 2 is the flow path switching valve according to claim 1, wherein the switching means is connected to the main valve so as to conduct the low-pressure path to an end surface opposite to the valve seat of the main valve. A first communication hole formed, a second communication hole formed in the main valve so as to conduct the auxiliary valve back space to an end surface opposite to the valve seat of the main valve, and opposite to the valve seat of the main valve A secondary valve that contacts the side end surface and rotates about the axis of the main valve to switch between the conductive state and the non-conductive state of the first communication hole and the second communication hole. .

  In the flow path switching valve according to claim 2, the conduction state and the non-conduction state of the first communication hole and the second communication hole are switched by the rotation of the secondary valve. When the first communication hole and the second communication hole are in the conductive state, the auxiliary valve back space and the low pressure path are in the conductive state, and when the first communication hole and the second communication hole are in the nonconductive state, the auxiliary valve back space and the low pressure path are in the conductive state. It becomes a non-conductive state.

  According to the flow path switching valve of the first aspect, the pressure equalizing valve equalizes the pressure by the operation in which the sub valve separates from the sub valve port, so that the pressure equalizing valve rotates against the resistance force to equalize the pressure. Thus, the opening area of the auxiliary valve port can be increased and pressure can be quickly equalized.

  According to the flow path switching valve of the second aspect, in addition to the effect of the first aspect, the conduction state / non-conduction state between the auxiliary valve back space and the low pressure passage can be switched only by rotating the auxiliary valve. So it becomes a simple configuration.

  Next, an embodiment of a flow path switching valve according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a flow switching valve according to an embodiment of the present invention in a cooling operation state (sectional view taken along the line BB in FIG. 6A), and FIG. 2 is a pressure equalizing valve of the flow switching valve. FIG. 3 is a sectional view taken along the line AA in FIG. 1, FIG. 4 is an enlarged sectional view of the pressure equalizing valve of the flow path switching valve, FIG. 5 is a perspective view of a secondary valve of the flow path switching valve, and FIG. 6 is an operation explanatory view of the flow path switching valve.

  The flow path switching valve of this embodiment has a case member 1 and a valve seat member 2 constituting a main body case. A substantially cylindrical valve chamber 11 is formed in the case member 1. The valve seat member 2 is formed with a circular trapezoidal valve seat 21, and a ring 22 is attached around the valve seat 21. The valve chamber 11 is sealed by fitting the valve seat 21 and the ring 22 into the opening of the valve chamber 11. A main valve 3 is accommodated in the valve chamber 11, and the main valve 3 includes a pressure equalizing valve 4. A secondary valve 5 is accommodated in the upper part of the main valve 3, and a drive unit 6 is attached from the upper part of the case member 1 to the valve chamber 11. A motor (not shown) of the drive unit 6 is accommodated in the upper part of the case member 1.

  As shown in FIG. 3, the valve seat 21 includes a D port 21 </ b> D as a “high pressure port” communicating with the valve chamber 11 and a refrigerant discharge port of a compressor (not shown), a refrigerant suction port of the compressor with the valve chamber 11. S port 21S as a “low pressure port” communicated with the valve chamber 11, a C switching port 21C as a “switching port” communicated with the valve chamber 11 and an outdoor heat exchanger (not shown), and an indoor heat exchanger (not shown). E switching ports 21E as “switching ports” are respectively formed. The D port 21D and the S port 21S are opened at positions spaced apart by 180 °, and the C switching port 21C and the E switching port 21E are opened 90 ° apart from the S port 21S, respectively. A stopper pipe 21a is inserted into the D port 21D, and the stopper pipe 21a protrudes into the valve chamber 11 from the end face (seal part) of the valve seat 21 (see FIG. 1).

  The main valve 3 is a substantially cylindrical member made of resin. As shown in FIG. 1, the main valve 3 is pivoted on a shaft 10 held at the upper end inside the case member 1 and the center of the valve seat 21. The valve seat 21 is supported so as to be rotatable in the valve chamber 11. As shown in FIG. 3, on the valve seat 21 side of the main valve 3, a low-pressure conducting portion 31 located on one side of the shaft 10 and stopper portions 32 </ b> A and 32 </ b> B formed on the opposite side of the low-pressure conducting portion 31. And have. The low voltage conducting part 31 has a semicircular arc shape surrounding the S port 21S and the E switching port 21E (or the S port 21S and the C switching port 21C), and the space inside the low voltage conducting part 31 is a low pressure path. It is 31A. The end face (seal part) on the valve seat 21 side of the low-pressure conducting part 31 is in contact with the sliding surface of the valve seat 21.

  As shown in FIG. 3, the stopper portions 32A and 32B of the main valve 3 are shaped to match the side surface of the stopper tube 21a of the D port 21D, and one of the stopper portions 32A and 32B is selected as the stopper tube 21a. The abutting of the main valve 3 regulates the rotation range of the main valve 3. One stopper portion 32A contacts the stopper tube 21a when switching to the cooling operation state, and the other stopper portion 32B contacts the stopper tube 21a when switching to the heating operation state.

  As shown in FIG. 4, the pressure equalizing valve 4 includes a sub valve port 41 formed in the main valve 3, a cylinder 42 formed in the main valve 3, a sub valve 43 inserted in the cylinder 42, It comprises a coil spring 44 as urging means for urging the valve 43 toward the auxiliary valve port 41 side. The sub valve port 41 forms a pressure equalizing hole that conducts to the low pressure passage 31 </ b> A in the low pressure conducting portion 31, and the cylinder 42 communicates with the sub valve port 41. The auxiliary valve 43 slides up and down in the cylinder 42 and can be seated and separated from the auxiliary valve port 41. In the cylinder 42, the space on the opposite side of the auxiliary valve port 41 from the auxiliary valve 43 Is a secondary valve back space 42A. Further, the auxiliary valve 43 is formed with an auxiliary valve passage 43a that conducts from the side portion to the auxiliary valve back space 42A.

  The main valve 3 is formed with a high pressure passage 33 that opens to the end of the sub valve port 41 at the side of the cylinder 42. The high pressure passage 33 connects the side of the sub valve 43 and the cylinder 42 to the side of the main valve 3. Conducted to the outside. A first communication hole 34 is formed between the cylinder 42 and the shaft 10 (see FIG. 1) to connect the low pressure passage 31A to the upper part of the main valve 3 (on the side opposite to the valve seat 2). A second communication hole 35 that connects the back space 42 </ b> A to the upper portion of the main valve 3 is formed in parallel with the first communication hole 34. A stopper 36 is erected at one place around the upper portion of the main valve 3.

  As shown in FIG. 5, the secondary valve 5 has a slide valve portion 51 having a substantially disc shape and a central boss portion 52, and is pivotally supported by the shaft 10 at the center of the boss portion 52. ing. In addition, on the surface of the slide valve portion 51 on the main valve 3 side, two conductive recesses 511 that conduct the first communication hole 34 and the second communication hole 35 are formed. Further, a stopper 51 a that contacts the stopper 36 of the main valve 3 is formed at one place around the slide valve portion 51.

  The drive unit 6 includes a worm wheel 61 pivotally supported on the shaft 10 and a worm gear 62 meshed with the worm wheel 61. The worm gear 62 is a drive shaft of a motor (not shown). It is fixed. The worm wheel 61 is pivotally supported on the shaft 10 by a boss portion 61 a, and the boss portion 61 a is fitted in a substantially rectangular square hole 52 a formed in the boss portion 52 of the secondary valve 5. A coil spring 63 that urges the secondary valve 5 toward the main valve 3 is disposed between the worm wheel 61 and the secondary valve 5. Thereby, the worm wheel 61 and the secondary valve 5 can be rotated around the shaft 10 in cooperation.

  With the above configuration, the operation is as follows. In the cooling operation state of FIG. 1, as shown in FIG. 4A, the first communication hole 34 and the second communication hole 35 are non-conductive by the bottom surface of the slide valve portion 51 of the sub-valve valve 5. The valve back space 42 </ b> A has the same pressure as the space outside the main valve 3 through the high-pressure passage 33 and the auxiliary valve passage 43 a. Accordingly, the sub valve 43 closes the sub valve port 41 and the pressure equalizing valve 4 is closed by the differential pressure between the high pressure of the sub valve back space 42A and the low pressure of the low pressure passage 31A and the biasing force of the coil spring 44. Thereby, the main valve 3 is seated on the valve seat 21 by the differential pressure in the outer space and the low pressure passage 31A, and the seated state is maintained.

  Next, when switching the flow path, the pressure equalizing valve 4 operates as follows. When the secondary valve 5 rotates and the conduction recess 511 of the secondary valve 5 conducts the first communication hole 34 and the second communication hole 35 as shown by the two-dotted line in FIG. 42A equalizes pressure with the low pressure passage 31A. Here, the force F1 acting in the direction in which the auxiliary valve 43 is seated on the auxiliary valve port 41 is a cross-sectional area of the auxiliary valve port 41 due to the biasing force of the coil spring 44 and the differential pressure between the pressure of the high pressure passage 33 and the pressure of the low pressure passage 31A. This is the sum of the force multiplied by. On the other hand, the force F2 acting in the direction of separating the auxiliary valve 43 from the auxiliary valve port 41 is a force obtained by multiplying the differential pressure between the pressure of the high pressure passage 33 and the pressure of the low pressure passage 31A by the sectional area of the outer diameter of the auxiliary valve 43. (Note that the weight of the auxiliary valve 43 is ignored.) Therefore, the biasing force of the coil spring 44, the outer diameter of the auxiliary valve 43, and the diameter of the auxiliary valve port 41 are set so that F1 <F2. Actually, the auxiliary valve 43 is separated from the auxiliary valve port 41 before the back space 42A and the low pressure path 31A are completely equalized, and the force acts in the direction in which the auxiliary valve 43 is seated by the refrigerant pressure in the high pressure path 33. The secondary valve 43 immediately moves away from the secondary valve port 41 as shown in FIG. As a result, the pressure equalizing valve 4 is opened, and the space outside the main valve 3 and the pressure in the low pressure passage 31A are equalized. Thus, the 1st communicating hole 34, the 2nd communicating hole 35, and the secondary valve 5 comprise the switching means which switches the conduction | electrical_connection state and non-conduction state of the subvalve back space 42A and the low pressure path 31A.

  Next, the switching operation between the cooling operation and the heating operation will be described with reference to FIG. FIG. 6 shows the positional relationship of each part in the state seen from the secondary valve 5 side with respect to the valve seat 21, and the notation such as a solid line, a broken line, and a slanted line does not indicate the front-rear position or structure. . The notation “D, S, C, E” indicates openings in the valve seat 21 of the D port 21D, the S port 21S, the C switching port 21C, and the E switching port 21E. 6A shows the cooling operation state, FIG. 6D shows the heating operation state, and FIGS. 6B, 6C, 6E, and 6F show the operation state switching process.

  First, it is assumed that the cooling operation shown in FIG. As shown in FIG. 6A, the D port 21D is electrically connected to the C switching port 21C, and the S port 21S is electrically connected to the E switching port 21E by the low pressure path 31A. Further, the first communication hole 34 and the second communication hole 35 are made non-conductive by the slide valve portion 51 of the secondary valve 5 (see FIG. 1). Then, the auxiliary valve 43 closes the auxiliary valve port 41 by the high-pressure refrigerant introduced from the D port 21D, and the pressure equalizing valve 4 is closed. Thereby, the space outside the main valve 3 becomes high pressure, and the low pressure passage 31A becomes low pressure. Therefore, the main valve 3 is seated on and closely contacted with the valve seat 21 due to the differential pressure between the space outside the main valve 3 and the low pressure passage 31A.

  Next, when switching from the cooling operation state to the heating operation state, if the drive unit 6 is driven while the compressor body remains in the operation state, only the secondary valve 5 rotates counterclockwise from the state of FIG. Move. When the stopper 51a of the secondary valve 5 comes into contact with the stopper 36 of the main valve 3 and enters the state shown in FIG. 6B, one of the conductive recesses 511 of the slide valve portion 51 is connected to the first communication hole 34 and the second communication hole. The hole 35 is conducted (see FIG. 2). As a result, the pressure equalizing valve 4 is opened as described above, the pressure outside the main valve 3 and the low pressure passage 31A are equalized, and the differential pressure applied to the main valve 3 is cancelled.

  At this time, since the stopper 51a of the secondary valve 5 is in contact with the stopper 36 of the main valve 3, both the secondary valve 5 and the main valve 3 rotate. Then, as shown in FIG. 6C, the stopper portion 32B of the main valve 3 comes into contact with the stopper pipe 21a, and the rotation of the secondary valve 5 and the main valve 3 is stopped. Since the stopper portion 32B abuts against the stopper tube 21a, an overload is applied to the motor and the drive circuit of the drive portion 6, so that this may be detected and the motor may be stopped. Next, the secondary valve 5 is rotated backward (clockwise) by a predetermined amount to move the conduction recess 511 from the position of the first communication hole 34 and the second communication hole 35, as shown in FIG. 6 (D). The first communication hole 34 and the second communication hole 35 are made non-conductive by the slide valve portion 51. As a result, the pressure equalizing valve 4 is closed as described above. Similarly to the above, by the high pressure refrigerant introduced from the D port 21D, the main valve 3 is seated and brought into close contact with the valve seat 21 by the differential pressure between the space outside the main valve 3 and the low pressure passage 31A. Become.

  When switching from the heating operation state to the cooling operation state, the compressor main body drives the drive unit 6 while maintaining the operation state, and rotates the secondary valve 5 clockwise from the state of FIG. 6 (D). When the stopper 51a of the secondary valve 5 comes into contact with the stopper 36 of the main valve 3 and the state shown in FIG. 6 (E) is reached, the other conduction recess 511 of the slide valve portion 51 is connected to the first communication hole 34 and the second communication hole 34. The hole 35 is conducted. As a result, the pressure equalizing valve 4 is opened as described above, the pressure outside the main valve 3 and the low pressure passage 31A are equalized, and the differential pressure applied to the main valve 3 is cancelled.

  At this time, since the stopper 51a of the secondary valve 5 is in contact with the stopper 36 of the main valve 3, both the secondary valve 5 and the main valve 3 rotate, and the main valve 5 as shown in FIG. The stopper portion 32A of the valve 3 comes into contact with the stopper tube 21a, and the rotation of the secondary valve 5 and the main valve 3 is stopped. Then, the secondary valve 5 is rotated reversely (counterclockwise) by a predetermined amount to move the conduction recess 511 from the position of the first communication hole 34 and the second communication hole 35, as shown in FIG. 6 (A). The first communication hole 34 and the second communication hole 35 are made non-conductive by the slide valve portion 51. As a result, the pressure equalizing valve 4 is closed as described above. The cooling operation state is entered.

  As described above, in the pressure equalizing valve 4, the auxiliary valve 43 is separated from the auxiliary valve port 41 due to the differential pressure between the auxiliary valve back space 42 </ b> A and the high pressure passage 33, so As compared with the type in which the pressure equalizing hole is opened by sliding the sub valve, the sub valve 43 can be easily separated, and the diameter of the sub valve port 41 as the pressure equalizing hole can be increased. Can be pressed. In the conventional example, when the auxiliary valve is slid by a motor or the like, the diameter of the pressure equalizing hole is about 4 mm, but the auxiliary valve port 41 in the embodiment has a large diameter of 4 mm or more. .

  In the above embodiment, the switching means is constituted by the first communication hole 34, the second communication hole 35, and the secondary valve 5, and the rotating secondary valve 5 prevents the secondary valve back space 42A and the low pressure passage 31A from being disconnected. Since the conduction state / conduction state is switched, the rotation of the main valve 3 can be interlocked with the rotation of the sub-valve 5, and the structure is simplified. However, this switching means is not limited to that of the embodiment, and any switching means may be used as long as it switches the non-conduction state / conduction state between the auxiliary valve back space and the low-pressure path. For example, in the main valve body, a passage and a secondary valve communicating the secondary valve back space and the low pressure passage are provided, and the secondary valve in the main valve body is opened / closed so as to be in a non-conductive state / conductive state. May be switched.

It is a longitudinal cross-sectional view of the cooling operation state of the flow-path switching valve concerning embodiment of this invention. It is a longitudinal cross-sectional view at the time of pressure equalization of the pressure equalizing valve of the flow path switching valve. It is an AA position sectional view of FIG. It is an expanded sectional view of the pressure equalizing valve of the flow path switching valve according to the embodiment. It is a perspective view of the secondary valve of the flow path switching valve. It is operation | movement explanatory drawing of the flow-path switching valve.

Explanation of symbols

1 Case member 2 Valve seat member 3 Main valve 4 Pressure equalizing valve 5 Secondary valve (switching means)
6 Drive unit 11 Valve chamber 21 Valve seat 21D D port (high pressure port)
21S S port (low pressure port)
21CC switching port (switching port)
21E E switching port (switching port)
21a Stopper pipe 31 Low-pressure conducting portion 31A Low-pressure passage 33 High-pressure passage 34 First communication hole (switching means)
35 Second communication hole (switching means)
36 Stopper 41 Sub valve port 42 Cylinder 42A Sub valve back space 43 Sub valve 43a Sub valve passage 44 Coil spring (biasing means)
51 Slide valve portion 52 Boss portion 511 Conductive recess 51a Stopper

Claims (2)

A main valve is accommodated in a cylindrical valve chamber so as to be rotatable about an axis of the valve chamber, and a low pressure port, a high pressure port and two switching ports are opened in a valve seat facing the main valve, and the main valve The low-pressure port is connected to one switching port by the low-pressure path formed at the same time, and the main valve is rotated to switch the communication destination of the two switching ports so that the high-pressure port is connected to the other switching port. A flow path switching valve for letting refrigerant flowing in from the high pressure port flow out to one switching port and flowing refrigerant flowing in from the other switching port to the low pressure port, outside the main valve leading to the high pressure port and the main valve In the flow path switching valve configured to maintain the seated state of the main valve by the differential pressure of the refrigerant with the low pressure path of
A pressure equalizing valve is provided in the main valve,
The pressure equalizing valve includes a sub-valve port that communicates with the low-pressure passage, a cylinder that communicates with the sub-valve port, a sub-valve that is inserted into the cylinder and can be seated and separated from the sub-valve port, Urging means for urging the sub valve toward the sub valve port side,
A high-pressure passage is formed in the main valve to connect the side portion of the sub-valve and the cylinder portion to the outside of the side surface of the main valve, and the high-pressure passage is connected to the sub-valve. A sub-valve passage communicating with the sub-valve back space on the opposite side of the port is formed,
The main valve is provided with switching means for switching between the conduction state and the non-conduction state between the sub-valve back space and the low-pressure path,
The sub-valve back space and the low-pressure passage are brought into a non-conducting state by the switching means, and the sub-valve back space is set to a high pressure through the high-pressure passage and the sub-valve passage so that the auxiliary valve Seated on the sub-valve port, the seated state of the main valve is maintained by the differential pressure between the space outside the main valve and the low pressure passage,
With the switching means, the auxiliary valve back space and the low pressure passage are in a conductive state, and the auxiliary valve back space is set to a low pressure so that the auxiliary valve is separated from the auxiliary valve port, and the space outside the main valve is A flow path switching valve characterized by equalizing the pressure of the low pressure path and rotating the main valve. The switching means is
A first communication hole formed in the main valve so as to conduct the low-pressure path to an end surface opposite to the valve seat of the main valve;
A second communication hole formed in the main valve so as to conduct the auxiliary valve back space to an end surface opposite to the valve seat of the main valve;
A sub-valve that contacts the end face opposite to the valve seat of the main valve and rotates about the axis of the main valve, and switches between conduction and non-conduction of the first communication hole and the second communication hole;
It is comprised from these, The flow-path switching valve of Claim 1 characterized by the above-mentioned.

Images