JP7425719B2 - Rotary type switching valve - Google Patents

Description

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

Conventionally, as this type of rotary switching valve (four-way switching valve), there is one disclosed in, for example, Japanese Patent Laid-Open No. 2005-256853 (Patent Document 1). In Patent Document 1, when switching from cooling to heating or from heating to cooling, the pressure in the space above the main valve (valve chamber) is reduced and the pressure from the high pressure port of the valve seat raises the main valve from the valve seat. The main valve is rotated and seated on the valve seat at a predetermined position. When the main valve is floated, the sub-valve in contact with the main valve is brought into contact with the valve body.

Japanese Patent Application Publication No. 2005-256853

In Patent Document 1, when the main valve is raised and rotated, the rising force of the main valve is received by the wide surface of the main body via the auxiliary valve, so a large friction torque is generated and a large driving torque is generated. It is necessary to secure it. Therefore, there is a problem that the drive section also becomes larger.

The present invention is a rotary type switching valve that lifts the main valve and rotates when switching flow paths.The present invention reduces frictional torque at the part receiving the lifting force of the main valve, reduces power consumption, and downsizes the drive unit. The task is to achieve this goal.

The rotary switching valve of the present invention includes a case member having a valve chamber, a valve seat provided opposite to the valve chamber, and rotatably disposed on the valve seat within the valve chamber about an axis. a separate body from the main valve, which is disposed between the case member and the valve seat and is rotatably arranged together with the main valve while holding the main valve on the axis; A rotary type switching valve that switches a flow path communicating with a port of the valve seat by lifting the main valve from the valve seat and rotating it, the main shaft of the rotary type switching valve comprising: a main shaft; It is characterized in that it is configured to be received by the main shaft and received by the case member via an end of the main shaft on the case member side.

In this case, a rotary type switching valve is preferable, wherein the end of the main shaft on the case member side is configured to transmit the lifting force to the case member side through point contact.

Preferably, the rotary switching valve is characterized in that the point contact is formed by a spherical surface at the end of the main shaft on the case member side.

Preferably, the rotary switching valve is configured to receive the main valve at a stepped portion in the center of the main shaft.

Further, a rotary type switching valve is preferable, characterized in that a washer is disposed between the stepped portion of the main shaft and the main valve.

According to the rotary type switching valve of the present invention, friction torque at a portion receiving the upward force of the main valve is reduced, power consumption can be reduced, and the drive unit can be downsized.

FIG. 2 is a longitudinal cross-sectional view of a main part of the main valve of the rotary switching valve in the seated state according to the embodiment of the present invention. FIG. 2 is a longitudinal cross-sectional view of a main part of the rotary switching valve according to the embodiment in a state where the pressure equalizing hole is open. FIG. 3 is an enlarged view of the central shaft end of the rotary switching valve in the embodiment. It is a figure showing an initial state of a rotary type switching valve in an embodiment. It is a figure showing the state of the front stage of the rotary type switching valve in the embodiment during flow path switching. It is a figure which shows the state of the latter stage during flow path switching of the rotary type switching valve in embodiment. It is a figure which shows the completion state of flow path switching of the rotary type switching valve in embodiment. It is a figure which shows the modification of the center-axis end part of the rotary type switching valve in embodiment. It is a figure showing a refrigeration cycle system of an embodiment.

Next, embodiments 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 type switching valve according to an embodiment of the present invention when the pressure equalizing hole is closed (the main valve is seated), and FIG. Figure 3 is an enlarged view of the central shaft end of the rotary type switching valve, and Figures 4 to 7 are the states of the rotary type switching valve according to its operation when switching the flow path. It is a figure showing a change. In FIGS. 4(C) to 7(C), the hatched area indicates the area where the main valve is seated and in contact with the valve seat. Note that the concept of "up and down" in the following description corresponds to the up and down in the drawings of FIGS. 1 and 2.

The rotary type switching valve 100 of this embodiment has a main valve 1, a sub-valve 2, a valve seat member 3, a case member 4, a drive section 5, and a central shaft 6 as a "main shaft". There is. The valve seat member 3 includes a thin cylindrical valve seat 31 and a flange portion 32 formed on the outer periphery of the valve seat 31. Furthermore, a substantially cylindrical valve chamber 4A is formed in the case member 4. A main valve 1, a sub-valve 2, a driving part 5, and a central shaft 6 are housed in the valve chamber 4A, and the central shaft 6 passes through the main valve 1, the sub-valve 2, and the driving part 5, and It is arranged between the seat member 3 and the case member 4. Then, the valve seat 31 is fitted into the opening of the valve chamber 4A of the case member 4, and the flange portion 32 is brought into contact with the lower end of the case member 4, so that the valve seat member 3 is attached to the case member 4. There is.

The main valve 1 is a resin member with a circular outer periphery, and is constructed by integrally forming a skirt part 11 on the valve seat 31 side, a cylindrical piston part 12, and a bearing part 13. A piston ring 12a is arranged around the circumference. Since the central shaft 6 passes through the central bearing portion 13, the main valve 1 is rotatably disposed around the axis X of the central shaft 6. Further, the space in which the piston part 12 is accommodated in the upper part of the valve chamber 4A is a cylindrical guide hole 41, and the main valve 1 is configured by sliding the piston ring 12a on the side surface of the guide hole 41 so that the central shaft 6 It is movable in the axis X direction. Further, a washer 14 is disposed at the upper end of the bearing portion 13 of the main valve 1 so that the central shaft 6 is inserted therethrough. Then, when the main valve 1 rises in the direction of the axis X, the main valve 1 comes into contact with the stepped portion 6a at the center of the vertical length of the central shaft 6 via the washer 14. Therefore, the rising force when the main valve 1 rises is transmitted to the central shaft 6 via the washer 14.

In addition, a dome-shaped low-pressure passage 11A is formed in the hakama part 11 of the main valve 1 on one side of the axis X, and a piston portion is formed closer to the axis X than the center of the ceiling of the low-pressure passage 11A. A pressure equalizing hole 11a is formed which communicates with the sub-valve housing chamber 12A inside the valve 12 (the pressure equalizing hole 11a is formed through the through hole 11b). Furthermore, a sliding rib 111 is formed on the bottom surface of the hakama portion 11 on the valve seat member 3 side so as to surround the outer periphery of the low pressure flow path 11A, and two sliding ribs 111 are formed on the opposite side of the axis X of the sliding rib 111. Sliding ribs 112, 112 are formed on the sides. Further, in the hakama portion 11, a high pressure space 11B is formed on the opposite side of the axis X with respect to the low pressure flow path 11A, and a D port 31D, which will be described later, is always open. Both ends of this opening in the direction around the axis X serve as stop pin abutting portions 113, respectively. This stop pin contact portion 113 contacts a stop pin 31a provided on the valve seat 31.

Moreover, the inside of the piston part 12 is a substantially cylindrical sub-valve housing chamber 12A, and the bottom of this sub-valve housing chamber 12A is provided with a main valve that is convex toward the secondary valve 2 side on the circumference around the axis X. A convex portion 121 is formed. The main valve convex portion 121 has a trapezoidal cross-sectional shape around the circumference, and both left and right ends in the circumferential direction are tapered surfaces. The main valve convex portion 121 is formed with the pressure equalizing hole 11a that opens into the sub-valve housing chamber 12A. Although there may be only one main valve protrusion 121, in this embodiment, in addition to this main valve protrusion 121, there are three main valve protrusions that have the same external shape as the main valve protrusion 121 and have no pressure equalizing hole. , are formed at equal intervals (equal angles) around the circumference. Further, sub-valve stoppers 122, 122 protruding toward the axis X side are formed at two locations on the inner circumferential surface of the sub-valve housing chamber 12A.

The sub-valve 2 has a substantially semi-disc-shaped flange portion 21 housed in the sub-valve housing chamber 12A of the piston portion 12 of the main valve 1 and a boss portion 22 at the center of the flange portion 21. A square hole 22a, which is approximately rectangular when viewed from above, is formed in the center. Further, on the surface of the flange portion 21 on the main valve 1 side, two sub-valve protrusions 211, 211 are formed on the same circumference as the main valve protrusion 121 and protrude toward the main valve 1 side. The two sub-valve convex portions 211, 211 have a trapezoidal cross-sectional shape around the circumference, and both left and right end portions in the circumferential direction are tapered surfaces. The two sub-valve protrusions 211, 211 are formed so as to be spaced apart from each other around the circumference so as to sandwich the main valve protrusion 121 therebetween. A pressure equalizing passage 21a that can communicate with the pressure equalizing hole 11a of the main valve 1 is formed between the two sub-valve convex portions 211, 211 (at an intermediate position). Further, the ends of the sub-valve convex portions 211, 211 in the axis X direction serve as sub-valve seal portions that seal the pressure equalizing hole 11a of the main valve convex portion 121 of the main valve 1. Further, the ends of the flange portion 21 around the axis X are main valve contact portions 212, 212, and the main valve contact portions 212, 212 are alternatively connected to the sub valve stoppers 122, 122 of the main valve 1. come into contact with

As shown in FIGS. 4 to 7 (C), the valve seat 31 includes a D port 31D that communicates with the valve chamber 4A and the refrigerant discharge side of the compressor, and a low-pressure flow path 11A that communicates with the refrigerant discharge side of the compressor. An S port 31S communicating with the suction side, a C switching port 31C communicating with the outdoor heat exchanger side, and an E switching port 31E communicating with the indoor heat exchanger side are each formed. Note that these ports are opened at positions spaced apart from each other by 90 degrees.

As shown in FIG. 1, the drive unit 5 includes a worm wheel 51 rotatably disposed around the central shaft 6, and a worm gear 52 meshed with the worm wheel 51. It is fixed to the drive shaft of a motor (not shown). The worm wheel 51 has a cam portion 51a that protrudes toward the sub-valve 2 side, and the worm wheel 51 is rotatably disposed on the central shaft 6 by the cam portion 51a. Further, this cam portion 51a is fitted into the substantially rectangular square hole 22a of the sub-valve 2. As a result, the sub valve 2 can slide only in the direction of the axis X with respect to the worm wheel 51 while its rotation around the axis X is restricted, and the sub valve 2 can rotate in cooperation with the worm wheel 51. do. Further, a coil spring 53 is disposed between the worm wheel 51 and the sub-valve 2 to bias the sub-valve 2 toward the main valve 1 side.

4 shows the initial state of channel switching, FIG. 5 shows the state of the previous stage during channel switching, FIG. 6 shows the state of the latter stage during channel switching, and FIG. 7 shows the completed state of channel switching. . In addition, in FIGS. 4 to 7, (B) is a partially exploded view seen from the direction of arrow A shown in (A).

First, in the state shown in FIGS. 1 and 4, the sub-valve convex portion 211 of the sub-valve 2 closes the pressure equalizing hole 11a of the main valve convex portion 121. When the drive section 5 is activated (rotates counterclockwise when viewed from above in FIG. 1), the driving force of the worm gear 52 and the worm wheel 51 is transmitted to the sub valve 2 via the cam section 51a of the worm wheel 51. The force is applied, and the sub-valve 2 rotates counterclockwise around the axis X. Note that at this time, the pressure equalization 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 is not affected by the frictional force with the valve seat 31. Therefore, 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 equalization hole 11a of the main valve protrusion 121 is opened by the pressure equalization flow path 21a. As a result, the pressure of the fluid above the main valve 1 escapes into the low pressure flow path 11A (low pressure side). As a result, the upper 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, as shown in FIGS. 2 and 5. The main valve 1 floats up from the valve seat 31, and the sub-valve protrusions 211 and the main valve protrusions 121 engage with each other alternately.

Then, by further rotating counterclockwise, the other sub-valve convex portion 211 of the sub-valve 2 becomes one of the tapered surfaces (slopes) which are the left and right ends in the circumferential direction around the axis X (due to the counter-clockwise rotation). The tapered surface at the right end) contacts one of the tapered surfaces (slanted surfaces) at both left and right ends in the circumferential direction of the main valve convex portion 121 (the tapered surface at the left end due to counterclockwise rotation), and the main valve 1 It rotates together with the valve 2, and as shown in FIG. 6, the stop pin contact portion 113 of the main valve 1 comes into contact with the stop pin 31a. When the sub valve 2 is further rotated counterclockwise in this state, the main valve 1 is in contact with the stop pin 31a and cannot be rotated counterclockwise any further, so the sub valve protrusion 211 By riding on the main valve protrusion 121 using the slopes of the tapered surfaces that are in contact with the protrusion 121 and further rotating it, the main valve abutment part 212 of the sub valve 2 becomes the main valve as shown in FIG. The sub-valve 2 comes into contact with one sub-valve stopper 122 in the circumferential direction and stops rotating, and the other sub-valve convex portion 211 closes the pressure equalizing hole 11a of the main valve convex portion 121. This prevents the flow of high-pressure fluid flowing into the upper part of the piston part 12 through the clearance between the piston ring 12a (and the piston part 12) and the guide hole 41 from escaping from the pressure equalizing hole 11a to the low-pressure flow path 11A. As a result, the upper side of the main valve 1 becomes high pressure, and as shown in Fig. 7, the main valve 1 seats on the valve seat 31 due to the pressure difference between the upper part of the main valve 1 and the inside of the low pressure flow path 11A (low pressure side). .

FIG. 3 is an enlarged view of the portion circled by the dashed-dotted line (the end of the central shaft 6) indicated by "P" in FIG. A cylindrical hole 42 having an inner diameter matching the outer diameter of the central shaft 6 is formed in the center of the top of the case portion 4 . Further, a ball 61 is fixed to the end of the central shaft 6 by caulking an annular rim portion. The bottom surface 42a of the cylindrical hole 42 of the case portion 4 is formed into a planar shape by polishing or the like, and when the main valve 1 and the central shaft 6 rise, the ball 61 comes into contact with the bottom surface 42a. That is, the ball 61 makes point contact with the bottom surface 42a of the cylindrical hole 42, so that the upward force of the main valve 1 is received by the case member 4 via the central shaft 6. Therefore, there is almost no frictional force around the axis X between the ball 61 of the central shaft 6 and the case member 4 (bottom surface 42a), and the rotational torque for rotating the main valve 1 may be small. Therefore, the drive unit 5 can be downsized.

FIG. 8 is a diagram showing a modification of the end portion of the central shaft 6. As shown in FIG. Modification 1 in FIG. 8(A) is one in which the burr created by cutting the cylindrical hole 42 is removed without polishing the bottom surface 42a of the cylindrical hole 42 of the case part 4, and the burr is removed from the bottom surface 42a. A recess 42b is formed by the deletion. In the first modification, the ball 61 of the central shaft 6 is brought into linear contact with the upper circumference of the opening of the conical recess 42b. Therefore, the frictional force becomes somewhat larger than that at the point contact. On the other hand, in the modification 2 of FIG. 8(B), a cylindrical hole 42' is further formed deep inside the cylindrical hole 42, and a gap between the recess 42b' in the cylindrical hole 42' and the ball 61 of the central shaft 6 is shown. A second ball 61' is disposed at the second ball 61'. In this second modification, the ball 61 and the second ball 61' make point contact on the axis X. Since it is a point contact, the frictional force is smaller than the line contact when the conical recess 42b of Modification 1 is formed, and the rotational torque is also smaller.

In addition, in the point contact embodiment shown in FIG. 3, the case 4 is made of a material that is lower in hardness than the ball 61, which usually has a high hardness (such as SUS440C), so as the usage time increases, the case 4 side becomes As the ball 61 wears and deforms, the contact area between the ball 61 and the case 4 increases, and the frictional force increases. However, in the configuration of this modification example 2, the ball 61 is usually in point contact with each other, which is highly hard. It is less likely to wear than the embodiment described above, has excellent durability, and can maintain a small rotational torque. Note that when the main valve 1 and the central shaft 6 rise in the axis X direction, the main valve 1 is received at the stepped portion 6a at the center of the vertical length of the central shaft 6. Compared to a configuration in which the main valve 1 is received at the lower part (steps, etc.) of the shaft 6, the center shaft 6 does not wobble to the left or right, resulting in stable rotational operation. In addition, by disposing the washer 14 between the stepped portion 6a of the central shaft 6 and the main valve 1, the lifting force when the main valve 1 and the central shaft 6 rise in the axis X direction is reduced. It can be received by the washer surface, which has a wider area than the stepped portion 6a of 6, and can be transmitted to the central shaft 6. Therefore, the contact pressure of the contact surface that transmits the lifting force of the main valve 1 to the central shaft 6 is lower than the contact pressure with the step portion 6a without a washer, and it is possible to prevent the surface contact portion of the main valve 1 from digging into the surface. Improves operational stability. In addition, since biting can be prevented simply by placing an inexpensive washer 14 in between, it is possible to increase the diameter of the shaft to increase the area of the stepped portion 6a of the central shaft 6 without using a washer, or to machine a flange on the shaft. It is possible to avoid an increase in cost due to cutting work such as applying.

As described above, since the structure is such that the rising force when the main valve 1 rises is received by the central shaft 6 (main shaft) and also by the end of the central shaft 6 (main shaft) on the case member 4 side, the ball 61 Of course, if the ball 61 is removed, the contact area between the central shaft 6 and the bottom surface 42a of the cylindrical hole 42 is at least as large as the cross-sectional area of the surface perpendicular to the axis X of the central shaft 6. However, since the contact area is extremely close to the axis X, the friction torque can be reduced to an extremely small amount.

In addition, as shown in FIG. 1, the pressure equalization hole 11a is electrically connected to the upper part of the through hole 11b, and the pressure equalization hole 11a of the main valve convex part 121 opens in the axis X direction (upward) from the low pressure flow path 11A. It is formed at a position close to the axis X (a position shifted toward the axis X side) with respect to the through hole 11b. That is, the main valve protrusion 121 and the sub-valve protrusion 211 are also formed at positions close to the axis X (positions shifted toward the axis X side). Therefore, the rotational torque when the auxiliary valve protrusion 211 rides on the main valve protrusion 121 is smaller than when the pressure equalization hole is opened at the position of the through hole 11b (position from the axis X), and the rotational torque of the drive unit 5 is reduced. Power can be reduced. In addition, in the embodiment shown in FIG. 1, the through hole 11b is a hole that opens in the axial direction (upward direction), but it is not limited to a hole that opens in the axial direction, and may be an oblique hole that is inclined with respect to the axial direction. Also good. Further, in this embodiment, the effect of forming a pressure equalizing 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 achieved. is as follows. Even if the pressure equalization channel 21a is not formed, when the pressure equalization 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 in the low pressure flow channel 11A and the sub valve storage chamber 12A. However, by forming the pressure equalizing passage 21a, the pressures in the low pressure passage 11A and the sub-valve housing chamber 12A can be equalized more reliably and quickly.

FIG. 9 is a diagram showing a refrigeration cycle system according to an embodiment, and is an example of a refrigeration cycle system for an air conditioner. The air conditioner includes a compressor 50, an outdoor heat exchanger 60, an expansion valve 70, an indoor heat exchanger 80, and a rotary switching valve 100 according to the embodiment, and each of these elements is connected to the illustrated part by a conduit. They are connected to form a heat pump type refrigeration cycle system.

The flow path of the refrigeration cycle system is switched between two flow paths, cooling operation and heating operation, by the rotary type switching valve 100 of the embodiment, and during cooling operation, the main valve 1 is rotated counterclockwise as described above. The state shown in FIG. 9(A) is obtained, and by rotating the main valve 1 clockwise in the opposite direction to that described above during heating operation, the state shown in FIG. 9(B) is obtained. Note that the rotary type switching valve 100 shown in FIG. 9 shows only the positional relationship of the main parts as seen from the back side of the valve seat part 3, and the broken line and solid line for a part of the main valve 1 indicate the valve seat and the corresponding part. The touching parts are shown. Further, the S port 31S, D port 31D, E switching port 31E, and C switching port 31C are indicated by the symbols "S", "D", "E", and "C", respectively, without the reference numerals.

During cooling operation in FIG. 9(A), in the rotary type switching valve 100, the S port "S" is connected to the E switching port "E" by the low pressure passage 11A of the main valve, and the D port "D" is connected by the high pressure space 11B. Connected to C switching port "C". Then, as shown by the arrow in the figure, the refrigerant as a fluid compressed by the compressor 50 flows into the D port "D" of the rotary type switching valve 100 and flows into the outdoor heat exchanger 60 from the C switching port "C". The refrigerant flowing in and flowing out from the outdoor heat exchanger 60 flows into the expansion valve 70 . Then, the refrigerant is expanded by the expansion valve 70 and supplied to the indoor heat exchanger 80. The refrigerant flowing out from the indoor heat exchanger 80 flows from the E switching port "E" to the S port "S" at the rotary type switching valve 100, and is circulated from the S port "S" to the compressor 50.

During heating operation in FIG. 9(B), in the rotary type switching valve 100, the S port "S" is connected to the C switching port "C" by the low pressure passage 11A of the main valve, and the D port "D" is connected by the high pressure space 11B. Connected to E switching port "E". Then, as shown by the arrow in the figure, the refrigerant compressed by the compressor 50 flows into the D port "D" of the rotary type switching valve 100, and then flows into the indoor heat exchanger 80 from the E switching port "E", Refrigerant flowing out of indoor heat exchanger 80 flows into 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 from the outdoor heat exchanger 60 flows from the C switching port "C" to the S port "S" at the rotary type switching valve 100, and is circulated from the S port "S" to the compressor 50.

In the embodiments described above, point contact is achieved by providing a ball at the end of the central shaft (main shaft), but the end of the central shaft may be simply machined into a spherical surface. Further, in the embodiment, an example has been described in which the main valve is rotated by engagement between the main valve convex portion and the auxiliary valve convex portion, but the structure for rotating the main valve may be other configurations.

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

1 Main valve 11A Low pressure passage 11B High pressure space 11a Pressure equalization hole 11b Through hole 113 Stop pin contact part 12 Piston part 121 Main valve protrusion 2 Sub valve 21 Flange part 211 Sub valve protrusion 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 42 Cylindrical hole 5 Drive section 51 Worm wheel 51a Cam section 52 Worm gear 53 Coil spring 6 Central shaft 61 Ball X Axis 50 Compressor 60 Outdoor heat exchanger 70 Expansion valve 80 Indoor heat exchanger 100 Rotary switching valve

Claims (5)

a case member having a valve chamber, a valve seat provided opposite to the valve chamber, a main valve rotatably disposed on the valve seat in the valve chamber, and the case member; a main shaft separate from the main valve, which is disposed between the valve seat and is rotatable together with the main valve while holding the main valve on the axis; A rotary type switching valve that switches a flow path communicating with a port of the valve seat by lifting the valve from the valve seat and rotating the valve,
A rotary type switching valve characterized in that the lifting force when the main valve rises is received by the main shaft and received by the case member via an end of the main shaft on the case member side. 2. The rotary switching valve according to claim 1, wherein an end of the main shaft on the case member side is configured to transmit the lifting force to the case member side through point contact. 3. The rotary type switching valve according to claim 2, wherein the point contact is formed by a spherical surface at an end of the main shaft on the side of the case member. 4. The rotary type switching valve according to claim 1, wherein the rotary type switching valve is configured to receive the main valve at a stepped portion in the center of the main shaft. 5. The rotary switching valve according to claim 4, wherein a washer is disposed between the stepped portion of the main shaft and the main valve.

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