JP7524151B2 - Rotary Switching Valve - Google Patents

Description

The present invention relates to a rotary switching valve used in heat pump refrigeration cycles and the like to switch the flow path of a refrigerant.

Conventionally, one such type of rotary switching valve (four-way switching valve) is disclosed in, for example, Japanese Patent No. 4602593 (Patent Document 1). The valve in Patent Document 1 rotates the main valve on the valve seat when switching from cooling to heating or from heating to cooling, but when the main valve is rotated, the sub-valve opens the pressure equalizing hole of the main valve, and a structure is used that reduces the pressure difference on the main valve. That is, the sub-valve rotates to open the pressure equalizing hole, and the main valve is rotated in a state where it is lifted off the valve seat due to the pressure difference, and then the sub-valve rotates in the opposite direction to close the pressure equalizing hole and seat the main valve.

Patent No. 4602593

In the case of Patent Document 1, when the sub-valve closes the pressure equalizing hole, the main valve floats off the valve seat, so there is almost no friction in the rotational direction of the main valve, or the main valve rotates integrally with the drive unit via the compression spring, so when the sub-valve rotates in the opposite direction, the main valve also rotates together with it, resulting in the problem that the pressure equalizing hole cannot be closed normally.

The objective of the present invention is to enable stable switching operation of the main valve in a rotary switching valve equipped with a sub-valve that opens and closes the pressure equalizing hole of the main valve.

The rotary switching valve of the present invention comprises a case member having a valve chamber, a valve seat provided opposite the valve chamber, a main valve rotatably disposed on the valve seat within the valve chamber about an axis, and a sub-valve rotatably disposed about the axis and configured to open and close a pressure equalizing hole of the main valve, and in this rotary switching valve, the pressure equalizing hole is opened to rotate the main valve, thereby switching a flow path communicating with a port of the valve seat. In this rotary switching valve, a main valve convex portion that is convex toward the sub-valve on a circumference around the axis of the main valve is formed, and two sub-valve convex portions are formed on the same circumference as the main valve convex portion of the sub-valve, convex toward the main valve side, and spaced apart so as to be able to sandwich the main valve convex portion, and a valve seat and a main valve convex portion are formed between the main valve convex portion and the sub-valve convex portion. the end portion about the axis of the sub-valve is a tapered surface, the pressure equalizing hole is formed in the main valve convex portion, and sub-valve seal portions for sealing the pressure equalizing hole are formed at the axial ends of the two sub-valve convex portions, the main valve convex portion is located between the two sub-valve convex portions and the sub-valve convex portion abuts against the main valve convex portion to transmit the rotational force of the sub-valve to the main valve , and after the abutment portion of the main valve abuts against a stopper provided on the valve seat, the sub-valve convex portion rides up on the main valve convex portion using the inclination of the tapered surfaces of the main valve convex portion and the sub-valve convex portion abutting against each other, and the sub-valve seal portion of the sub-valve convex portion seals the pressure equalizing hole .

In this case, it is preferable for the rotary switching valve to be configured such that when the auxiliary valve protrusion is located at the position of the main valve protrusion around the axis, the auxiliary valve seal portion seals the pressure equalizing hole of the main valve protrusion, and when the main valve protrusion is located between the two auxiliary valve protrusions, the pressure equalizing hole is opened.

Furthermore, a rotary switching valve is preferred in which the orthogonal position of the center point of the opening of the pressure equalizing hole of the main valve on the auxiliary valve storage chamber side when viewed from an axially upward direction is shifted toward the axial line relative to the orthogonal position of the center point of the opening of the pressure equalizing hole on the low pressure flow passage side when viewed from an axially downward direction.

Furthermore, a rotary switching valve is preferably characterized in that a pressure equalizing flow passage that can communicate with the pressure equalizing hole of the main valve protrusion is formed between the two sub-valve protrusions of the sub-valve.

The rotary switching valve of the present invention is configured so that when the main valve protrusion is located between the two sub-valve protrusions and the pressure equalizing hole formed in the main valve protrusion is open, the sub-valve protrusion abuts against the main valve protrusion to transmit the rotational force of the sub-valve to the main valve, allowing for stable switching operation of the main valve.

2 is a longitudinal sectional view of a main part of a rotary switching valve in a seated state according to an embodiment of the present invention. FIG. 3 is a longitudinal sectional view of a main portion of the rotary switching valve in the embodiment in a pressure equalizing hole open state. FIG. FIG. 4 is a diagram showing a seating position of a main valve during cooling operation of the rotary switching valve in the embodiment. FIG. 4 is a diagram showing a seating position of a main valve during heating operation of the rotary switching valve in the embodiment. FIG. 2 is a perspective view of a main valve of the rotary switching valve according to the embodiment. FIG. 2 is a perspective view of an auxiliary valve of the rotary switching valve according to the embodiment. FIG. 4 is a simplified diagram illustrating the operation of the sub-valve and the main valve in the embodiment. FIG. 2 is a diagram showing an initial state of the rotary switching valve in the embodiment. 1 is a diagram showing a state of a front stage during flow path switching of a rotary switching valve in an embodiment. FIG. 1 is a diagram showing a rear stage state during flow path switching of a rotary switching valve in an embodiment. FIG. 5A and 5B are diagrams illustrating a completed state of flow path switching of the rotary switching valve in the embodiment. 1 is a diagram showing a refrigeration cycle system according to an embodiment; FIG. 11 is a perspective view of a main valve of a rotary switching valve according to another embodiment. FIG. 13 is a perspective view of an auxiliary valve of a rotary switching valve according to another embodiment. 1A and 1B show a rotary switching valve according to an embodiment, in which FIG. 1A is an explanatory diagram of a main valve convex portion, and FIG. 1B is an explanatory diagram of an auxiliary valve convex portion. 13A and 13B show a rotary switching valve according to another embodiment, in which FIG. 13A is an explanatory diagram of a main valve convex portion, and FIG. 13B is an explanatory diagram of an auxiliary valve convex portion.

Next, an embodiment of the rotary switching valve and refrigeration cycle system of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of the main part of the rotary switching valve in an embodiment of the present invention with the pressure equalizing hole closed (main valve seated state), FIG. 2 is a vertical cross-sectional view of the main part of the rotary switching valve in an embodiment of the present invention with the pressure equalizing hole open (main valve floating state), FIG. 3 is a diagram showing the seating position of the main valve during cooling operation of the rotary switching valve, FIG. 4 is a diagram showing the seating position of the main valve during heating operation of the rotary switching valve, FIG. 5 is a perspective view of the main valve of the rotary switching valve, and FIG. 6 is a perspective view of the auxiliary valve of the rotary switching valve. In FIG. 3 and FIG. 4, the hatched parts indicate the parts where the main valve is seated and in contact with the valve seat. The concepts of "upper and lower" in the following description correspond to the upper and lower in the drawings of FIG. 1 and FIG. 2.

The rotary switching valve 100 of this embodiment has a main valve 1, an auxiliary valve 2, a valve seat member 3, a case member 4, a drive unit 5, and a central shaft 6. The valve seat member 3 is configured with a thin cylindrical valve seat 31 and a flange portion 32 formed on the outer periphery of the valve seat 31. A substantially cylindrical valve chamber 4A is formed in the case member 4. The main valve 1, the auxiliary valve 2, the drive unit 5, and the central shaft 6 are housed in the valve chamber 4A, and the central shaft 6 is disposed between the valve seat member 3 and the case member 4, passing through the main valve 1, the auxiliary valve 2, and the drive unit 5. The valve seat 31 is fitted into the opening of the valve chamber 4A of the case member 4, and the valve seat member 3 is attached to the case member 4 so that the flange portion 32 abuts against the lower end of the case member 4.

The main valve 1 is a resin member with a circular periphery, and is constructed by integrally forming a skirt portion 11 on the valve seat 31 side, a cylindrical piston portion 12, and a bearing portion 13, and a piston ring 12a is disposed around the piston portion 12. The central shaft 6 passes through the central bearing portion 13, so that the main valve 1 is disposed so as to be freely rotatable around the axis X of the central shaft 6. The space that houses the piston portion 12 at the top of the valve chamber 4A is a cylindrical guide hole 41, and the main valve 1 can move in the direction of the axis X of the central shaft 6 by sliding the piston ring 12a against the side of the guide hole 41.

In addition, the skirt portion 11 of the main valve 1 is formed with a low-pressure flow passage 11A drilled in a dome shape on one side of the axis X, and a pressure equalizing hole 11a that communicates with the auxiliary valve storage chamber 12A inside the piston portion 12 is formed closer to the axis X than the center of the ceiling of the low-pressure flow passage 11A (the pressure equalizing hole 11a is formed via a through hole 11b). In addition, a sliding rib 111 is formed on the bottom surface of the skirt portion 11 on the valve seat member 3 side so as to surround the outer periphery of the low-pressure flow passage 11A, and sliding ribs 112, 112 are formed in two places on the opposite side of the sliding rib 111 from the axis X. Furthermore, the skirt portion 11 has a high-pressure space 11B formed on the opposite side of the axis X from the low-pressure flow passage 11A, where a D port 31D (described later) is always open. The outside of this high-pressure space 11B is open within a range of approximately 90°, and both ends of this opening in the direction around the axis X each form a stop pin abutment portion 113. This stop pin abutment portion 113 abuts against a stop pin 31a provided on the valve seat 31.

As shown in FIG. 5A, the inside of the piston portion 12 is a substantially cylindrical auxiliary valve storage chamber 12A, and a main valve protrusion 121 that protrudes toward the auxiliary valve 2 on the circumference around the axis X is formed at the bottom of the auxiliary valve storage chamber 12A. The main valve protrusion 121 has a trapezoidal cross section around the circumference, and both the left and right ends in the circumferential direction are tapered surfaces. The main valve protrusion 121 is formed with the pressure equalizing hole 11a that opens into the auxiliary valve storage chamber 12A. There may be only one main valve protrusion 121, but in this embodiment, in addition to the main valve protrusion 121, three main valve protrusions that have the same outer shape as the main valve protrusion 121 and do not have a pressure equalizing hole are formed at equal intervals (equal angles) around the circumference. In addition, auxiliary valve stoppers 122, 122 that protrude toward the axis X are formed at two points on the inner peripheral surface of the auxiliary valve storage chamber 12A.

As shown in FIG. 6, the sub-valve 2 has a substantially semicircular flange 21 and a boss 22 at its center, which are housed in the sub-valve chamber 12A of the piston 12 of the main valve 1. The boss 22 has a substantially rectangular hole 22a at its center. The flange 21 has two sub-valve protrusions 211, 211 on the main valve 1 side, which are convex toward the main valve 1 side on the same circumference as the main valve protrusion 121. The two sub-valve protrusions 211, 211 have a trapezoidal cross-sectional shape around the circumference, and the ends on both the left and right sides of the circumference are tapered surfaces. The two sub-valve protrusions 211, 211 are formed at a distance around the circumference so that the main valve protrusion 121 can be sandwiched between them. Between the two sub-valve protrusions 211, 211 (at the middle position), a pressure equalizing flow passage 21a is formed that can communicate with the pressure equalizing hole 11a of the main valve 1. In addition, the ends of the sub-valve protrusions 211, 211 in the axial direction are sub-valve seals that seal the pressure equalizing hole 11a of the main valve protrusion 121 of the main valve 1. Furthermore, the ends of the flange portion 21 around the axial direction are main valve abutment portions 212, 212, which selectively abut against the sub-valve stoppers 122, 122 of the main valve 1.

As shown in Figures 3 and 4, the valve seat 31 is formed with a D port 31D that is connected to the valve chamber 4A and the refrigerant discharge side of the compressor, an S port 31S that is connected to the low pressure flow path 11A and the refrigerant intake side of the compressor, a C switch port 31C that is connected to the outdoor heat exchanger side, and an E switch port 31E that is connected to the indoor heat exchanger side. These ports are opened at positions spaced 90° apart from each other.

As shown in FIG. 1, the drive unit 5 has a worm wheel 51 arranged rotatably on the central axis 6 and a worm gear 52 meshed with the worm wheel 51, and the worm gear 52 is fixed to the drive shaft of a motor (not shown). The worm wheel 51 has a cam portion 51a protruding toward the auxiliary valve 2, and the worm wheel 51 is arranged rotatably on the central axis 6 by the cam portion 51a. The cam portion 51a is fitted into a substantially rectangular hole 22a of the auxiliary valve 2. As a result, the auxiliary valve 2 can slide only in the direction of the axis X with its rotation around the axis X restricted relative to the worm wheel 51, and the auxiliary valve 2 rotates in cooperation with the worm wheel 51. A coil spring 53 is arranged between the worm wheel 51 and the auxiliary valve 2 to bias the auxiliary valve 2 toward the main valve 1.

Figure 7 is a simplified diagram explaining the operation of the sub-valve 2 and main valve 1, and shows the parts around axis X expanded on a straight line. Also, Figures 8 to 11 are diagrams showing state changes according to the operation of the sub-valve 2 and main valve 1 when switching flow paths, with Figure 8 showing the initial state, Figure 9 showing the state at the front stage during flow path switching, Figure 10 showing the state at the rear stage during flow path switching, and Figure 11 showing the completed state of flow path switching. Also, in Figures 8 to 11, (B) is a partially exploded view seen from the direction of arrow A shown in (A).

1, 7(A) and 8, the sub-valve protrusion 211 of the sub-valve 2 closes the pressure equalizing hole 11a of the main valve protrusion 121. Then, when the drive unit 5 operates (rotates counterclockwise when viewed from above in FIG. 1), the driving force of the worm gear 52 and the worm wheel 51 applies a rotational force to the sub-valve 2 through the cam portion 51a of the worm wheel 51, and the sub-valve 2 rotates counterclockwise around the axis X. At this time, the pressure equalizing hole 11a is closed and the main valve 1 is pressed against the valve seat 31 due to the pressure difference, so even if the sub-valve 2 rotates, the main valve 1 cannot rotate due to the frictional force with the valve seat 31, and only the sub-valve 2 rotates. When the sub-valve 2 rotates, the sub-valve protrusion 211 slides on the main valve protrusion 121, and the pressure equalizing hole 11a of the main valve protrusion 121 is opened by the pressure equalizing flow path 21a. As a result, the pressure of the fluid at the top of the main valve 1 escapes into the low-pressure flow path 11A (low-pressure side). As a result, the top side of the main valve 1 becomes low pressure, and an upward force is generated in the main valve 1 due to the pressure difference between the high-pressure space 11B and the high pressure in the valve chamber 4A, and as shown in Figures 7(B), 2, and 9, the main valve 1 floats up from the valve seat 31, and the sub-valve protrusion 211 and the main valve protrusion 121 alternately mesh with each other.

Then, by further rotating counterclockwise, one of the tapered surfaces (slope) at both left and right ends of the other sub-valve convex portion 211 of the sub-valve 2 in the circumferential direction about the axis X (the tapered surface at the right end due to counterclockwise rotation) abuts against one of the tapered surfaces (slope) at both left and right ends of the main valve convex portion 121 in the circumferential direction (the tapered surface at the left end due to counterclockwise rotation), as shown in Figure 7 (C), and the main valve 1 rotates together with the sub-valve 2, and the stop pin abutment portion 113 of the main valve 1 abuts against the stop pin 31a, as shown in Figures 7 (D) and 10. If the sub-valve 2 is rotated further counterclockwise in this state, the main valve 1 cannot rotate any further counterclockwise because it is abutting against the stop pin 31a, so as shown in Figure 7 (E), the sub-valve convex portion 211 rides onto the main valve convex portion 121 using the inclination of the tapered surfaces of the main valve convex portion 121 and the sub-valve abutting against the main valve convex portion 121. By rotating further, as shown in Figures 7 (F) and 11, the main valve abutment portion 212 of the sub-valve 2 abuts against the sub-valve stopper 122 of the main valve 1 in the circumferential direction, causing the sub-valve 2 to stop rotating, and the other sub-valve convex portion 211 closes the pressure equalizing hole 11a of the main valve convex portion 121. As a result, the high-pressure fluid that flows into the top of the piston portion 12 through the clearance between the piston ring 12a (and piston portion 12) and the guide hole 41 cannot escape from the pressure equalizing hole 11a to the low-pressure flow path 11A, so the upper side of the main valve 1 becomes high pressure, and as shown in Figures 7 (F) and 11, the main valve 1 seats on the valve seat 31 due to the pressure difference between the top of the main valve 1 and the inside of the low-pressure flow path 11A (low-pressure side).

As described above, the rotation of the auxiliary valve 2 opens the pressure equalizing hole 11a of the main valve protrusion 121, and after rotating the main valve 1 to a predetermined position, the auxiliary valve 2 is rotated in the same direction without rotating in the opposite direction when closing the pressure equalizing hole 11a. Therefore, the pressure equalizing hole 11a can be reliably closed while holding the main valve 1 in a predetermined position, and a stable switching operation of the main valve 1 can be obtained. This effect can be achieved because both the left and right ends of the main valve protrusion 121 and the auxiliary valve protrusion 211 in the circumferential direction around the axis X are tapered surfaces, so that after the main valve 1 abuts the stopper, the auxiliary valve protrusion 211 can ride up to the main valve protrusion 121 using the inclination of the tapered surfaces abutting the valve protrusion 121, continue to rotate, and close the pressure equalizing hole 11a. The angle of the tapered surface is subject to appropriate design changes depending on the specifications of the usage conditions (high differential pressure conditions, low differential pressure conditions, fluid conditions, etc.) and the structure of each part, and the angle range of design changes due to these conditions is included. The taper angle is the angle between one of the tapered surfaces of the trapezoidal portion of the cross-sectional shape around the circumference of the main valve convex portion 121 and the sub-valve convex portion 211 and the base of the trapezoid, and is usually preferably in the range of 30° to 75°. More preferably, it is in the range of 45° to 60°.

Here, there should be at least one main valve protrusion 121. Also, there should be at least two sub-valve protrusions 211. However, in the above embodiment, the main valve protrusions 121 and the sub-valve protrusions 211 are formed in equal numbers (four each in the embodiment) at rotationally symmetric positions about the axis X, so that the sub-valve 2 can maintain a stable position with respect to the axis X when the sub-valve protrusions 211 are in opposing contact with the main valve protrusion 121 in the direction of the axis X (when the pressure equalizing hole 11a is closed), and stable operation can be obtained without leakage of fluid, etc.

As shown in FIG. 1, the pressure equalizing hole 11a is connected to the upper part of the through hole 11b, and the pressure equalizing hole 11a and the through hole 11b together function as the "pressure equalizing hole" of the main valve 1. The orthogonal position of the center point of the opening of the auxiliary valve storage chamber 12A side of the pressure equalizing hole 11a of the main valve convex portion 121 as viewed from the axial upward direction is formed at a position close to the axis X (position shifted toward the axis X side) with respect to the orthogonal position of the center point of the opening of the low-pressure flow path 11A side of the through hole 11b as the "pressure equalizing hole" opened in the axial X direction (upward) from the low-pressure flow path 11A as a "pressure equalizing hole" is formed at a position close to the axis X (position shifted toward the axis X side) with respect to the orthogonal position of the center point of the opening of the low-pressure flow path 11A side of the through hole 11b as viewed from the axial downward direction. In other words, the main valve convex portion 121 and the auxiliary valve convex portion 211 are also formed at a position close to the axis X (position shifted toward the axis X side) with respect to the orthogonal direction of the axis X of the center point of the opening of the low-pressure flow path 11A side of the through hole 11b as viewed from the axial downward direction. Therefore, the rotation torque when the sub-valve protrusion 211 rides on the main valve protrusion 121 is smaller than that when a pressure equalizing hole is opened in the axial direction (upward) at the center point (position from the axial direction) of the opening of the low-pressure flow passage 11A side of the through hole 11b when viewed from the axial downward direction, and the power of the drive unit 5 can be reduced. In the embodiment of FIG. 1 etc., the through hole 11b is a hole opened in the axial direction (upward), but it is not limited to a hole opened in the axial direction, and it may be an oblique hole inclined with respect to the axial direction. In the above embodiment, the structure of two holes, the pressure equalizing hole 11a opened in the axial direction (upward) and the through hole 11b opened in the axial direction (upward), is described with reference to the figure, but both holes may be oblique holes inclined with respect to the axial direction. In the above embodiment, the pressure equalizing hole 11a and the two holes communicating with the through hole 11b function together as the pressure equalizing hole of the main valve 1, but the number of holes is not limited to two. For example, only one pressure equalizing hole may be formed as an oblique hole inclined with respect to the axial direction. In this embodiment, the effect of forming a pressure equalizing flow passage 21a that can communicate with the pressure equalizing hole 11a of the main valve protrusion 121 between the two sub-valve protrusions 211 in the sub-valve 2 is as follows. Even if the pressure equalizing flow passage 21a is not formed, when the pressure equalizing hole 11a is opened, it is possible to flow through the narrow gap between the main valve and the sub-valve and equalize the pressure between the low-pressure flow passage 11A and the sub-valve storage chamber 12A. However, by forming the pressure equalizing flow passage 21a, the pressure between the low-pressure flow passage 11A and the sub-valve storage chamber 12A can be equalized more reliably and quickly.

Figure 12 shows an embodiment of a refrigeration cycle system, and is an example of a refrigeration cycle system for an air conditioner. The air conditioner has a compressor 50, an outdoor heat exchanger 60, an expansion valve 70, an indoor heat exchanger 80, and a rotary switching valve 100 of the embodiment, and each of these elements is connected by conduits as shown in the figure to form a heat pump type refrigeration cycle system.

The flow path of the refrigeration cycle system is switched to two flow paths for cooling operation and heating operation by the rotary switching valve 100 of the embodiment. During cooling operation, the main valve 1 is rotated counterclockwise as described above to become the state shown in FIG. 12(A), and during heating operation, the main valve 1 is rotated clockwise in the opposite direction to the above description to become the state shown in FIG. 12(B). Note that the rotary switching valve 100 shown in FIG. 12 shows only the positional relationship of the main parts as seen from the back side of the valve seat portion 3, and the dashed lines and solid lines of some of the main valve 1 show the parts abutting the valve seat. Also, the reference numbers are omitted for the S port 31S, D port 31D, E switching port 31E, and C switching port 31C, and are indicated by the symbols "S", "D", "E", and "C", respectively.

During cooling operation in FIG. 12(A), in the rotary switching valve 100, the S port "S" is connected to the E switching port "E" by the low pressure flow path 11A of the main valve, and the D port "D" is connected to the C switching port "C" by the high pressure space 11B. Then, as shown by the arrows in the figure, the refrigerant as a fluid compressed by the compressor 50 flows into the D port "D" of the rotary switching valve 100 and flows into the outdoor heat exchanger 60 from the C switching port "C", and the refrigerant flowing out of the outdoor heat exchanger 60 flows into the expansion valve 70. Then, the refrigerant is expanded by this expansion valve 70 and supplied to the indoor heat exchanger 80. The refrigerant flowing out of the indoor heat exchanger 80 flows from the E switching port "E" to the S port "S" in the rotary switching valve 100, and is circulated from the S port "S" to the compressor 50.

During heating operation in FIG. 12(B), in the rotary switching valve 100, the S port "S" is connected to the C switching port "C" by the low pressure flow path 11A of the main valve, and the D port "D" is connected to the E switching port "E" by the high pressure space 11B. Then, as shown by the arrows in the figure, the refrigerant compressed by the compressor 50 flows into the D port "D" of the rotary switching valve 100 and flows into the indoor heat exchanger 80 from the E switching port "E", and the refrigerant flowing out of the indoor heat exchanger 80 flows into the expansion valve 70. Then, the refrigerant is expanded by this expansion valve 70 and supplied to the outdoor heat exchanger 60. The refrigerant flowing out of this outdoor heat exchanger 60 flows from the C switching port "C" to the S port "S" in the rotary switching valve 100, and is circulated from the S port "S" to the compressor 50.

In the above description of the embodiment, the explanation was given under conditions of differential pressure, such as when the refrigeration cycle is operating. Therefore, when the pressure equalizing hole 11a is open, the main valve floats from the valve seat, and the explanation of flow path switching has been given under the assumption that the main valve is floating. However, even under conditions where there is no differential pressure, such as when the refrigeration cycle is not operating, the main valve does not float from the valve seat, but the main valve protrusion and the sub-valve protrusion mesh and come into contact, making it possible to switch the flow path. Therefore, it is not assumed that the main valve floats as in the above description of the embodiment, and flow path switching can be achieved with this configuration whether it floats or not.

In addition, in the above explanation of the embodiment, the explanation has mainly been given up to the switching of the flow path to cooling operation using the simplified display diagram of Figure 7, etc., and has been given up to the point where, by rotating counterclockwise, the main valve 1 abuts against the stopper pin 31a and stops rotating, and with further rotation, the sub-valve 2 abuts against the sub-valve stopper 122 and stops rotating, and the main valve 1 seats on the valve seat 3, completing the switching. In terms of the switching function, the explanation up to this point is not a problem, but if the switching is completed in this state (Figures 11 and 7(F)), the rotational load (torque) from the drive unit 5 will remain applied in the counterclockwise direction. For example, torque will remain applied in the counterclockwise direction to the meshing portion of the worm wheel 51 and the worm gear 52 that is screwed together (residual torque will remain). If this state is left in place for a long period of time and used, if the gears are made of resin, the meshing gear parts will creep and the gears will deform and will no longer be able to transmit rotation. Also, if the main valve 1 and sub-valve 2 are made of resin, the surface of the main valve abutment part 212 of the sub-valve and the surface of the sub-valve stopper 122 of the main valve 1 that abuts thereon will creep and deform, causing the pressure equalizing hole 11a to tend to open, etc., which may cause the main valve 1 to leak. In response to this, after the above-mentioned flow path switching is completed (Figures 11 and 7(F)), the sub-valve is rotated slightly (a small amount of rotation within the amount of backlash in the gear meshing gap) in the reverse direction (the reverse rotation relative to the counterclockwise flow path switching described above, i.e. clockwise rotation) to complete the switching operation. This prevents residual torque from remaining in the meshing portion of the gear parts or in the rotating contact surfaces of the sub-valve 2 and main valve 1, thereby suppressing creep of the gear parts and valve leakage from the main valve 1.

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

For example, in the above-described embodiment, four main valve protrusions 121 and four sub-valve protrusions 211 are formed at rotationally symmetric positions around the axis X, but the present invention is not limited to this.

Now, with reference to Figs. 13 to 16, a rotary switching valve in another embodiment of the present invention will be described. Fig. 13 is a perspective view of the main valve of a rotary switching valve in another embodiment of the present invention, and Fig. 14 is a perspective view of the auxiliary valve of the rotary switching valve. Fig. 16(A) is an explanatory diagram of the main valve convex portion of the rotary switching valve, and Fig. 16(B) is an explanatory diagram of the auxiliary valve convex portion of the rotary switching valve. Fig. 15(A) is an explanatory diagram of the main valve convex portion of the rotary switching valve in the embodiment of Figs. 1, 2, 5, 6, and 8 to 11, and Fig. 15(B) is an explanatory diagram of the auxiliary valve convex portion of the rotary switching valve in the embodiment of Figs. 1, 2, 5, 6, and 8 to 11.

Specifically, as shown in Figs. 13 and 14, in which the same reference numerals are used to designate parts corresponding to Figs. 5(A) and 6(B), it is preferable that three main valve protrusions 121 and three sub-valve protrusions 211 are formed at rotationally symmetric positions about the axis X.

In this case, as shown in FIG. 13, three main valve protrusions 121 that are convex toward the sub-valve 2 on the circumference around the axis X are formed on the bottom of the sub-valve storage chamber 12A of the main valve 1. The main valve protrusions 121 have a trapezoidal cross-sectional shape around the circumference, and both the left and right ends in the circumferential direction are tapered surfaces. One of the main valve protrusions 121 has a pressure equalizing hole 11a that opens into the sub-valve storage chamber 12A, and the other two do not have a pressure equalizing hole. These three main valve protrusions are formed at equal intervals (equal angles) around the circumference. In addition, sub-valve stoppers 122, 122 that protrude toward the axis X are formed at two points on the inner peripheral surface of the sub-valve storage chamber 12A.

As shown in FIG. 14, it is preferable that three sub-valve protrusions 211 are formed on the main valve 1 side surface of the flange portion 21 of the sub-valve 2, which are convex toward the main valve 1 side on the same circumference as the main valve protrusion 121. These three sub-valve protrusions 211 have a trapezoidal cross-sectional shape around the circumference, and the ends on both the left and right sides in the circumferential direction are tapered surfaces. These three sub-valve protrusions 211 are formed at equal intervals (equal angles) around the circumference so as to sandwich the pressure equalizing flow path 21a that can communicate with the main valve protrusion 121 and the pressure equalizing hole 11a of the main valve 1. In addition, the end of the sub-valve protrusion 211 in the axis X direction is a sub-valve seal portion that seals the pressure equalizing hole 11a of the main valve protrusion 121 of the main valve 1. Furthermore, the ends of the flange portion 21 around the axis X are main valve abutment portions 212, 212, which selectively abut against the sub-valve stoppers 122, 122 of the main valve 1.

In this way, when three main valve protrusions 121 and three auxiliary valve protrusions 211 are provided at positions rotationally symmetrical about the axis X (FIGS. 16A and 16B), the auxiliary valve 2 can maintain a more stable position relative to the axis X when the auxiliary valve protrusions 211 are in contact with the main valve protrusion 121 in the direction of the axis X (i.e., when the pressure equalizing hole 11a is closed). In addition, compared to when four main valve protrusions 121 and four auxiliary valve protrusions 211 are provided (FIGS. 15A and 15B), the sealing width H (the minimum length between the opening end of the pressure equalizing hole 11a on the upper surface 121a of the main valve protrusion 121 and the starting line from the upper surface 121a of the main valve protrusion 121 to the tapered surface (slope)) between the upper surface 121a of the main valve protrusion 121 and the upper surface 211a of the auxiliary valve protrusion 211 when the pressure equalizing hole is in the "closed" state can be secured. This allows for further improvement in valve leakage resistance and more stable operation.

1 Main valve 11A Low pressure flow path 11B High pressure space 11a Pressure equalizing hole 11b Through hole 113 Stop pin abutment portion 12 Piston portion 121 Main valve protrusion portion 2 Sub-valve 21 Flange portion 211 Sub-valve protrusion portion 3 Valve seat member 31 Valve seat 31D D port 31S S port 31E E switching port 31C C switching port 31a Stop pin 4 Case member 4A Valve chamber 5 Drive portion 51 Worm wheel 51a Cam portion 52 Worm gear 53 Coil spring 6 Central axis X Axis line 50 Compressor 60 Outdoor heat exchanger 70 Expansion valve 80 Indoor heat exchanger 100 Rotary type switching valve

Claims (4)

A rotary switching valve comprising: a case member having a valve chamber; a valve seat provided opposite to the valve chamber; a main valve disposed on the valve seat within the valve chamber to be rotatable about an axis; and an auxiliary valve disposed rotatable about the axis and for opening and closing a pressure equalizing hole of the main valve, wherein the pressure equalizing hole is opened and the main valve is rotated, thereby switching a flow path communicating with a port of the valve seat,
A main valve convex portion that is convex toward the sub-valve is formed on a circumference around the axis of the main valve, and two sub-valve convex portions that are convex toward the main valve on the same circumference as the main valve convex portion of the sub-valve and are spaced apart so as to sandwich the main valve convex portion,
The ends of the main valve protrusion and the sub-valve protrusion around the axis are tapered surfaces,
the pressure equalizing hole is formed in the main valve protrusion, and sub-valve seal portions for sealing the pressure equalizing hole are formed at the axial ends of the two sub-valve protrusions, the main valve protrusion is positioned between the two sub-valve protrusions, and the sub-valve protrusion is configured to abut against the main valve protrusion to transmit the rotational force of the sub-valve to the main valve ,
a valve seat that is in contact with the main valve and has a stopper provided on the valve seat, and the sub-valve continues to rotate while the sub-valve protrusion rides on the main valve protrusion using the inclination of the tapered surfaces of the main valve protrusion and the sub-valve protrusion that abut against each other, and the sub-valve seal portion of the sub-valve protrusion seals the pressure equalizing hole . The rotary switching valve according to claim 1, characterized in that the auxiliary valve seal seals the pressure equalizing hole of the main valve convex when the auxiliary valve convex is located at the position of the main valve convex around the axis, and the pressure equalizing hole is open when the main valve convex is located between the two auxiliary valve convex parts. 3. A rotary switching valve according to claim 1, wherein a position perpendicular to the axis of a center point of an opening of the pressure equalizing hole of the main valve on the auxiliary valve storage chamber side, as viewed from an axial upward direction, is shifted toward the axis with respect to a position perpendicular to the axis of a center point of the opening of the pressure equalizing hole on the low pressure flow passage side , as viewed from an axial downward direction. The rotary switching valve according to any one of claims 1 to 3 , characterized in that a pressure equalizing passage capable of communicating with the pressure equalizing hole of the main valve protrusion is formed between the two sub-valve protrusions in the sub-valve.

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