JP7491734B2 - Motor-operated valve and refrigeration cycle system - Google Patents

Description

The present invention relates to an electrically operated valve for use in a refrigeration cycle system and a refrigeration cycle system.

For example, Patent Document 1 discloses an invention that discloses an electric valve (pilot-type control valve) that includes a valve housing having a valve seat, a main valve having a main valve portion that can seat on the valve seat, a pilot valve that can seat on the valve seat (pilot port) inside the main valve, and a pilot valve drive mechanism that drives the pilot valve forward and backward. The drive mechanism raises the pilot valve to cause the pilot valve body to leave the valve seat, and the back pressure chamber on the rear side of the main valve body communicates with the space on the outlet port side of the valve seat through the valve seat, thereby reducing the pressure difference between the spaces before and after the main valve body, thereby preventing chattering when the main valve is caused to leave the valve seat by the main valve drive mechanism.

JP 2013-87795 A

However, in conventional motor-operated valves such as that disclosed in Patent Document 1, in addition to a pilot valve drive mechanism that drives the pilot valve forward and backward, a main valve drive mechanism that drives the main valve forward and backward is provided, which makes the structure complicated and the device larger. Also, the main valve body has a pressure equalization hole that connects the inlet port and the back pressure chamber, which makes it easy for high-pressure fluid to flow into the back pressure chamber from the inlet port side. Therefore, even if the pilot valve body is lifted off the valve seat, the pressure in front of and behind the main valve body is not sufficiently equalized, resulting in a relatively large pressure difference. This requires a large lifting thrust when lifting the main valve off the valve seat, which further increases the size of the drive mechanism.

The object of the present invention is to provide an electric valve and a refrigeration cycle system that can reduce the size of the drive unit.

The motor-operated valve of the present invention comprises a valve body, a main valve seat formed in a main valve chamber within the valve body, a main valve element movably supported by the valve body and attachable to and detachable from the main valve seat, a sub-valve seat formed in a sub-valve chamber within the main valve element, a sub-valve element attachable to and detachable from the sub-valve seat within the main valve element, and a drive section which drives the sub-valve element to move forward and backward so as to follow the main valve element, and is a two-stage motor-operated valve in which an upper end of the sub-valve element abuts against the main valve element at a position away from the sub-valve seat, thereby lifting and moving the main valve element in an opening direction, and a back pressure chamber communicating with the sub-valve chamber is provided on the opposite side of the main valve element to the main valve seat. a flow path area A of a first flow path formed by a radial gap between the tapered outer surface of the needle portion of the sub-valve element and the inner surface of the port of the sub-valve seat when the sub-valve element starts to move the main valve element in the opening direction, which is a state in which the upper end of the sub-valve element abuts the main valve element and the main valve element is in a closed state, and a flow path area B of a second flow path communicating the main valve chamber and the back pressure chamber are such that A>B, and the second flow path is provided in the gap between the outer peripheral surface of the part of the main valve element that has the largest outer diameter and a valve guide hole that is integrally machined into the valve body for moving the main valve element in the opening/closing direction .

According to this invention, a primary port is provided on the main valve chamber side and a secondary port is provided on the main valve seat side. When high-pressure fluid flows from the primary port into the main valve chamber, the flow path area B is smaller than the flow path area A, so that the fluid flowing from the primary port through the second flow path into the back pressure chamber can be throttled, suppressing the pressure rise in the back pressure chamber when the main valve body starts to be pulled up and suppressing an increase in the pressure difference before and after the main valve body. Therefore, the lifting thrust required to open the main valve body can be suppressed, making it possible to miniaturize the drive unit.

In this case, a third flow passage is provided to communicate the main valve chamber and the auxiliary valve chamber, and the third flow passage is formed of a through hole having an inner diameter dimension larger than the distance from the outer peripheral surface of the main valve body constituting the gap in which the second flow passage is provided to the valve guide hole of the valve body, and it is preferable that the relationship between the flow passage area A, the flow passage area B, and the flow passage area C of the third flow passage is A>B+C.

It is also preferable that the sealing surface with the main valve seat is formed by a surface that is chamfered from the outer peripheral surface of the main valve body toward the inner peripheral surface.

The refrigeration cycle system of the present invention is characterized by having the above-mentioned motor-operated valve.

According to the present invention, the drive unit can be made smaller, as in the motor-operated valve described above, so that a refrigeration cycle system with a smaller motor-operated valve can be achieved.

In this case, it is preferable to have multiple motor-operated valves with their secondary side joints connected to the outdoor heat exchanger.

The motor-operated valve and refrigeration cycle system of the present invention make it possible to miniaturize the drive unit.

1 is a vertical cross-sectional view showing a motor-operated valve according to a first embodiment of the present invention. 2 is an enlarged longitudinal sectional view showing a main portion of the motor-operated valve. FIG. FIG. 3 is an enlarged view of a portion E in FIG. 2 . FIG. 4 is a vertical cross-sectional view showing a sub-valve element in a raised state in the motor-operated valve. FIG. 4 is a vertical cross-sectional view showing a state in which a main valve body is lifted in the motor-operated valve. 4 is a graph showing valve opening characteristics of the motor-operated valve. FIG. 6 is a vertical cross-sectional view showing a main portion of a motor-operated valve according to a second embodiment of the present invention. FIG. 11 is a vertical cross-sectional view showing a main portion of a motor-operated valve according to a third embodiment of the present invention. 5A is a plan view of a piston ring used in the motor-operated valve, FIG. 5B is a cross-sectional view taken along line F-F in FIG. 5A, and FIG. 5C is a cross-sectional view of a modified piston ring. 1 is a diagram showing an example of a refrigeration cycle system of the present invention.

The motor-operated valve according to the first embodiment of the present invention will be described with reference to Figs. 1 to 5. As shown in Fig. 1, the motor-operated valve 10 according to this embodiment is a two-stage motor-operated valve including a valve body 1, a sub-valve element 2 supported movably relative to the valve body 1, a sub-valve seat 31 to which the sub-valve element 2 is attached and detached, a main valve element 3 having the sub-valve element 2 and the sub-valve seat 31 therein, a main valve seat 13 to which the main valve element 3 is attached and detached, a stepping motor 5 as a drive unit, and back pressure chambers S1 and S2. Note that the concepts of "upper and lower" in the following description correspond to the upper and lower in the drawing in Fig. 1.

As shown in FIG. 2, the valve body 1 has a cylindrical valve housing member 1A, a cylindrical case 6 fixed to the upper part of the valve housing member 1A, and a support member 7 fixed to the upper end opening of the case 6.

The valve housing member 1A has a generally cylindrical main valve chamber 1C formed therein, and a first joint pipe 11 (a primary joint when the inlet side of the valve body 1 is connected to the valve housing chamber 1C and a secondary port when the outlet side is connected to the valve housing chamber 1C) with a port 11a (a primary port when the inlet side of the valve body 1 is connected to the valve housing chamber 1C and a secondary joint when the outlet side is connected to the valve housing chamber 1C) is attached to the valve housing member 1A by brazing. The case 6 is assembled so as to fit onto the outer periphery of the reduced diameter portion 1b at the upper end of the valve housing member 1A, and is fixed to the valve housing member 1A by brazing the bottom outer periphery. The support member 7 is fixed to the upper end opening of the case 6 by crimping the rim 6a via a fixing bracket 61.

The sub-valve body 2 is supported movably relative to the valve body 1 inside the main valve body 3 described below, and has a rod shaft 22 with a needle portion 21 at its lower end, and a valve holder 8 fixed to the upper end of the rod shaft 22.

The rod shaft 22 has a spring bearing 23 formed at its upper end, which is fixed integrally to the lower end of the valve holder 8. The valve holder 8 has a spring bearing 83, a compression coil spring 84, and a washer 85 inside its cylindrical portion 81. Furthermore, the valve holder 8 is inserted into a guide hole 3a of the main valve body 3 (described below) and is supported so as to be slidable in the axial direction L.

The sub-valve seat 31 is a valve seat to which the needle portion 21 of the sub-valve body 2 is attached and detached, and is formed at the bottom of the sub-valve chamber 3C, which is connected to the guide hole 3a of the main valve body 3 described below and has a larger diameter than the guide hole 3a.

The main valve body 3 has an auxiliary valve body 2 and an auxiliary valve seat 31 inside, a guide hole 3a is formed on the upper side, and an auxiliary valve chamber 3C is formed on the lower side. The lower side of the main valve body 3 is inserted into the valve guide hole 19, and the upper side of the main valve body 3 is inserted into the valve guide hole 17 of the support member 7, so that it can slide in the direction of the axis L. The main valve body 3 has a spring receiver 32 on its upper part, and a compression coil spring 18 is provided between the spring receiver 32 and the upper end surface of the cylindrical guide space 70 of the support member 7 that guides the main valve body 3. The lower end of the main valve body 3 has a surface 33 that is chamfered from the outer peripheral surface to the inner peripheral surface, as shown in FIG. 3. The side of the main valve body 3 has a through hole 34, which communicates with the auxiliary valve chamber 3C and the back pressure chamber S1 described later, and also communicates with the second back pressure chamber S2 described later through a through hole 71 provided on the side of the support member 7. Furthermore, a second flow passage R2 that connects the main valve chamber 1C and the back pressure chamber S1 is provided in the gap between the main valve body 3 and the valve guide hole 19. The back pressure chambers S1 and S2 are also connected by a number of through holes in the support member 7 and the fixing bracket 61 in the axial direction L (vertical direction) in a cross section (not shown).

The main valve seat 13 is a valve seat to which the main valve element 3 is attached and detached, and is formed at the bottom of the main valve chamber 1C. As shown in Figs. 1 to 3, when the main valve element 3 is in the closed state, a sealing surface is formed with the chamfered surface 33. In addition, a second coupling pipe 12 (secondary side coupling on the outflow side to the valve body 1 and primary side coupling on the inflow side) having a tip side port 12a (secondary port on the outflow side to the valve body 1 and primary port on the inflow side) is attached by brazing from the underside of the valve housing member 1A to the valve port in the center of the main valve seat 13. As shown in Figs. 4 and 5, when the sub-valve element 2 is separated from the sub-valve seat 31 and in the open state, it is in communication with the sub-valve chamber 3C. Furthermore, as shown in Fig. 5, the second coupling pipe 12 is also in communication with the main valve chamber 1C when the main valve element 3 is separated from the main valve seat 13 and in the open state.

The stepping motor 5 has a can 51, a magnet rotor 52 provided within the can 51, a rotor shaft 53, a stator coil 54, and a rotation stopper mechanism 9 for the stepping motor 5.

The can 51 is fixed airtightly to the upper end of the case 6 by welding or the like, and houses the support member 7, the magnet rotor 52 described below, and the rotation stopper mechanism 9. The magnet rotor 52 has its outer periphery magnetized with multiple poles, and the rotor shaft 53 is fixed to its center. The rotor shaft 53 has its lower end connected to the rod shaft 22 of the first valve body 2 via the valve holder 8. The rotor shaft 53 also has a male thread 53a formed on the upper surface of its middle part. This male thread 53a is screwed into the female thread 7a of the support member 7, and these male thread 53a and female thread 7a constitute the screw feed mechanism 16 of the drive unit. The screw feed mechanism 16 converts the rotational motion of the stepping motor 5 into linear motion of the rotor shaft 53, so that the first valve body 2 is driven forward and backward in the axis L direction. The stator coil 54 is arranged on the outer circumference of the can 51, and when a pulse signal is given to the stator coil 54, the magnet rotor 52 rotates according to the number of pulses, causing the rotor shaft 53 to rotate.

The rotation stopper mechanism 9 of the stepping motor 5 includes a cylindrical guide 96 that hangs down along the axis from the center of the ceiling of the can 51, a screw guide 97 fixed to the outer periphery of the guide 96, and a movable slider 98 that can rotate and move up and down while being guided by the screw guide 97. The movable slider 98 is provided with a protrusion 98a that protrudes radially outward, and the magnet rotor 52 is provided with a protrusion 52a that extends upward and abuts against the protrusion 98a. When the magnet rotor 52 rotates, the protrusion 52a pushes the protrusion 98a, causing the movable slider 98 to rotate and move up and down following the screw guide 97.

The spiral guide 97 is formed with an upper end stopper 97a that determines the uppermost position of the magnet rotor 52, and a lower end stopper (not shown) that determines the lowermost position of the magnet rotor 52. When the movable slider 98 that descends with the forward rotation of the magnet rotor 52 abuts against the lower end stopper, the movable slider 98 becomes unable to rotate at this abutting position, thereby restricting the rotation of the magnet rotor 52, stopping the descent of the sub-valve body 2, and also stopping the descent of the main valve body 3 that follows this. On the other hand, when the movable slider 98 that rises with the reverse rotation of the magnet rotor 52 abuts against the upper end stopper 97a, the movable slider 98 becomes unable to rotate at this abutting position, thereby restricting the rotation of the magnet rotor 52, stopping the rise of the sub-valve body 2, and also stopping the rise of the main valve body 3 that follows this. In addition, a gap is provided between the upper surface of the washer 86 that rests on the upper end of the valve holder 8 and the lower end of the spring receiver 32, so the main valve body 3 does not rise while this gap exists (see Figures 1 and 2).

The back pressure chamber S1 is provided in the valve body 1, and the second back pressure chamber S2 is provided in the can 51. As described above, the back pressure chambers S1 and S2 communicate with the auxiliary valve chamber 3C via the through holes 34 and 71. As described above, the back pressure chambers S1 and S2 communicate with each other via a plurality of through holes in the axis L direction (vertical direction) in a cross section (not shown) of the support member 7 and the fixing metal fitting 61. Note that the back pressure chamber of the present invention includes not only the back pressure chambers S1 and S2, but also all pressure spaces such as the auxiliary valve chamber 3C and the guide space 70 that resist the thrust when the main valve body 3 is lifted.

In this embodiment, the flow path formed by the gap between the sub-valve element 2 and the sub-valve seat 31 when the sub-valve element 2 starts to move the main valve element 3 in the opening direction is defined as the first flow path R1, its flow path area is defined as A, and the flow path area of the second flow path R2 is defined as B. The relationship between the flow path area A and the flow path area B is A>B (see FIG. 5). Note that the flow path area A of the present invention changes in size as shown in the graph of FIG. 6 described later. Specifically, the flow path area A is preferably at least twice the flow path area B. Also, the flow path area A is more preferably at least 5 times the flow path area B. As for the range of the magnification, the flow path area A is preferably 5 to 40 times the flow path area B. By specifying the ratio of the flow path area A to the flow path area B in this way, the upper and lower pressure receiving surfaces of the main valve element 3 are reliably equalized, and the main valve element 3 can be reliably pulled up with a small pulling force by the stepping motor 5 (drive unit).

According to the above embodiment, the port 11a of the first joint pipe 11 on the main valve chamber 1C side is the primary port, and the port 12a of the second joint pipe 12 on the main valve seat 13 side is the secondary port. When a high-pressure fluid flows into the main valve chamber 1C from the port 11a, the flow path area B is smaller than the flow path area A, so that the fluid such as the refrigerant flowing from the primary port 11a through the second flow path R2 into the back pressure chamber S1 can be throttled, suppressing the pressure rise in the back pressure chamber S1 when the main valve body 3 starts to be pulled up, and suppressing the increase in the pressure difference before and after the main valve body 3. Therefore, the pulling thrust required when the main valve body 3 is opened can be suppressed, and the stepping motor 5 (drive unit) can be made smaller.

Based on FIG. 6, when the fluid flows from the first joint pipe 11 to the second joint pipe 12, to explain in more detail, from the state of FIG. 1, even if a pulse signal is given to the stator coil 54 and the magnet rotor 52 rotates according to the number of pulses, for a short time from 0 pulses (until the valve opening point), the sub-valve element 2 is seated on the sub-valve seat 31 (at this time, the load of the compression coil spring 84 is applied to the sub-valve seat 31 through the sub-valve element 2, and although it is small and not shown in FIG. 1 and FIG. 2, a gap is opened between the folded top surface part at the upper end of the cylindrical part 81 of the valve holder 8 and the washer 85), and the valve opening area is 0. After that, the sub-valve element 2 gradually begins to open, and the gap between the port of the sub-valve seat 31 and the taper of the needle part 21 of the sub-valve element 2 increases, and the valve opening area (flow rate) increases proportionally until the relationship between the flow area A, which increases from the state of FIG. 1, and the flow area B becomes A = B. Here, the flow of the fluid due to the increase in the valve opening area is from the port 11a at the tip of the first joint pipe 11 through the second flow path R2 to the through hole 34, the sub-valve chamber 3C, the first flow path R1, and the port 12a at the tip of the second joint pipe 11 in this order. Before reaching this point, the primary side (back pressure chambers S1, S2, guide space 70, etc.) is in a non-uniform pressure region where the pressure is higher than that of the secondary side. After the sub-valve element 2 is opened beyond the state A=B and A>B, the pressure of the back pressure chamber side and the secondary side are in an equal pressure region where they are approximately equal. Since the main valve element 3 can start opening from the state shown in FIG. 4 in this advantageous state where the pressure of the back pressure chamber side and the secondary side are approximately equal in an equal pressure region, the required lifting thrust can be suppressed and the stepping motor 5 can be made smaller. In the graph of FIG. 6, until the upper surface of the washer 86 placed on the valve holder 8, which is the upper end of the sub-valve body 2, comes into contact with the spring bearing 32 of the main valve body 3, the main valve body 3 is in a closed state, and even if the sub-valve body 2 is fully open and in a state of A>B, the fluid passes through the first flow path R1 after passing through the second flow path R2, so the flow rate is determined by the flow path area B, and the valve opening area does not change beyond the flow path area B. After that, the main valve body 3 gradually begins to open, and the valve opening area (flow rate) increases proportionally until it is fully open. In the graph of FIG. 6, the vertical axis is the valve opening area, but the same change is shown when replaced with the flow rate.

In addition, the sealing surface with the main valve seat 13 is formed by the chamfered surface 33 from the outer peripheral surface of the main valve body 3 toward the inner peripheral surface, and the outer diameter of the lower end of the main valve body 3 and the diameter of the seating portion of the main valve seat 13 are approximately the same diameter, so a reliable pressure balance structure can be achieved with a simple structure.

The second flow path R2 is provided in the gap between the main valve element 3 and the valve guide hole 19 formed in the valve body 1 to move the main valve element 3 in the opening and closing directions, and the configuration is simplified, which allows the entire motor-operated valve 10 to be made smaller.

Next, a motor-operated valve 10 according to a second embodiment of the present invention will be described with reference to FIG. 7. The motor-operated valve 10 of this embodiment is a two-stage motor-operated valve that includes a valve body 1, a sub-valve element 2, a sub-valve seat 31, a main valve element 3, a main valve seat 13, a stepping motor 5 as a drive unit, and back pressure chambers S1 and S2, just like the motor-operated valve 10 of the first embodiment. In the motor-operated valve 10 of this embodiment, a portion of the configuration of the main valve element 3 is different from that of the motor-operated valve 10 of the first embodiment. The differences will be described in detail below.

In the motor-operated valve 10 of this embodiment, a through hole 35 is provided on the side of the main valve body 3, and a third flow passage R3 is provided that communicates the primary port 11a with the auxiliary valve chamber 3C inside the main valve body 3. If the flow passage area of the third flow passage R3 is C, the relationship between the flow passage area A of the first flow passage R1, the flow passage area B of the second flow passage R2, and the flow passage area C is A>B+C, which is different from the motor-operated valve 10 of the first embodiment. Specifically, the flow passage area A is preferably at least twice the flow passage area B+C. Moreover, the flow passage area A is more preferably at least 5 times the flow passage area B+C. As for the range of the magnification, the flow passage area A is preferably 5 to 40 times the flow passage area B+C. By specifying the ratio of the flow passage area A to the flow passage area B+C in this way, the upper and lower pressure receiving surfaces of the main valve body 3 are reliably equalized, and the main valve body 3 can be reliably pulled up with a small pulling force by the stepping motor 5 (drive unit).

In the motor-operated valve 10 of this embodiment, when foreign matter is present in the fluid, the foreign matter is allowed to flow from the third flow path R3 into the auxiliary valve chamber 3C, preventing the foreign matter from entering the second flow path R2 and reducing its function (such as malfunction due to foreign matter getting caught in the gap of the second flow path R2).

In addition, the motor-operated valve 10 of this embodiment also applies the same theory as that explained in FIG. 6 of the first embodiment. That is, when the fluid flows from the first joint pipe 11 to the second joint pipe 12, a pulse signal is given to the stator coil 54 from the state of FIG. 1, and even if the magnet rotor 52 rotates according to the number of pulses, the sub-valve body 2 is seated on the sub-valve seat 31 for a short time from 0 pulse (until the valve opening point) (at this time, the load of the compression coil spring 84 is applied to the sub-valve seat 31 through the sub-valve body 2, and although it is small and not shown in FIG. 7, a gap is opened between the bent top surface part at the upper end of the cylindrical part 81 of the valve holder 8 and the washer 85), and the valve opening area is 0. Thereafter, the sub-valve element 2 gradually starts to open, and the gap between the port of the sub-valve seat 31 and the taper of the needle portion 21 of the sub-valve element 2 increases, and the valve opening area (flow rate) increases proportionally until the relationship between the flow area A, the flow area B, and the flow area C becomes A=B+C. Here, the flow of fluid due to the increase in the valve opening area is a flow in the order from the port 11a at the tip side of the first joint pipe 11 through the second flow path R2 to the introduction hole 34, the sub-valve chamber 3C, the first flow path R1, and the port 12a at the tip side of the second joint pipe 11, and in addition, a flow in the order from the port 11a at the tip side of the first joint pipe 11 through the third flow path R3 (the introduction hole 35), the sub-valve chamber 3C, the first flow path R1, and the port 12a at the tip side of the second joint pipe 11 is joined. Before reaching this point, the primary side (back pressure chambers S1, S2, guide space 70, etc.) is in a non-uniform pressure region where the pressure is higher than that of the secondary side. After the sub-valve element 2 is opened beyond the state of A=B+C and A>B+C, the pressures on the back pressure chamber side and the secondary side are in a substantially equal pressure range. In this advantageous state of the equal pressure range where the pressures on the back pressure chamber side and the secondary side are substantially the same, the main valve element 3 can start opening from the state of FIG. 4, so the required lifting thrust can be suppressed and the stepping motor 5 can be made smaller. Note that in the part where the valve opening area is flat in the graph of FIG. 6, the main valve element 3 is in a valve-closed state until the upper surface of the washer 86 placed on the valve holder 8, which is the upper end of the sub-valve element 2, abuts against the spring bearing 32 of the main valve element 3. Even if the sub-valve element 2 is in a fully open state and in a state of A>B+C, the fluid passes through the first flow path R1 after passing through the second flow path R2 and the third flow path R3, so the flow rate is determined by the flow path area B and the flow path area C, and the valve opening area does not change beyond the flow path area B+C. After that, the main valve element 3 gradually starts to open, and the valve opening area (flow rate) increases proportionally until the fully open state is reached. In the graph in Figure 6, the vertical axis is the valve opening area, but the same changes are observed when replaced with the flow rate.

Next, a motor-operated valve 10 according to a third embodiment of the present invention will be described with reference to Figures 8 and 9. The motor-operated valve 10 of this embodiment is a two-stage motor-operated valve that includes a valve body 1, a sub-valve element 2, a sub-valve seat 31, a main valve body 3, a main valve seat 13, a stepping motor 5 as a drive unit, and back pressure chambers S1 and S2, just like the motor-operated valve 10 of the second embodiment. In the motor-operated valve 10 of this embodiment, a portion of the configuration of the valve body 1 differs from that of the motor-operated valve 10 of the second embodiment. The differences will be described in detail below.

The motor-operated valve 10 of this embodiment is different from the motor-operated valve 10 of the second embodiment in that the valve guide hole 19 in the valve housing member 1A of the valve body 1 is formed by inserting a substantially cylindrical press-in member 1B, and the press-in member 1B is provided with a C-shaped flow passage forming member 14 (e.g., a piston ring) made of a resin material such as PPS (see Figures 9(a) and (b)). The flow passage area B of the second flow passage R2 is defined by the joint gap 14a of this flow passage forming member 14.

In the motor-operated valve 10 of the present embodiment described above, the flow area B of the second flow passage R2 is defined by the joint gap 14a of the flow passage forming member 14, so that the flow passage area B can be made even smaller. This makes it possible to further prevent foreign matter from entering the second flow passage R2 and causing its function to deteriorate (such as malfunction due to foreign matter getting caught in the gap of the second flow passage R2). In addition, in terms of the machining accuracy of the parts, it is very time-consuming to form the second flow passage R2 extremely small using only a clearance, as in the first and second embodiments, so by using this embodiment, it is possible to more easily and reliably prevent the deterioration of function more than by using only a clearance.

Also, as shown in FIG. 9(c), a C-shaped flow path forming member 14 (piston ring) with a groove 14b formed on the inside may be provided. In this case, since the groove 14b is formed on the inside of the flow path forming member 14, the flow path forming member 14 becomes a labyrinth seal device that reduces the flow rate in the second flow path R2 because the groove 14b acts as a labyrinth when the fluid enters, and the flow rate of the fluid to the back pressure chamber S1 can be further reduced.

Next, the refrigeration cycle system of the present invention will be described with reference to FIG. 10. FIG. 10 is a diagram showing an example of the refrigeration cycle system of the present invention. In FIG. 10, reference numeral 100 denotes an expansion valve using the motor-operated valve 10 of each of the above-mentioned embodiments, 200 denotes an outdoor heat exchanger mounted on an outdoor unit, 101 denotes an expansion valve using a single-stage general motor-operated valve, 300 denotes an indoor heat exchanger mounted on an indoor unit, 400 denotes a four-way valve serving as a flow path switching valve, and 500 denotes a compressor. The expansion valves 100, 101, the outdoor heat exchanger 200, the indoor heat exchanger 300, the four-way valve 400, and the compressor 500 are each connected by a conduit as shown in the figure, constituting a heat pump type refrigeration cycle system. Note that an accumulator, a pressure sensor, a temperature sensor, and the like are omitted from the illustration. In addition, in the refrigeration cycle system shown as an example, the second joint pipe 12 of the motor-operated valve 10 is connected to the outdoor heat exchanger 200.

The flow path of the refrigeration cycle system is switched between two flow paths, one for cooling operation and the other for heating operation, by the four-way valve 400. During cooling operation, as shown by the solid arrows in FIG. 9, the refrigerant compressed by the compressor 500 flows from the four-way valve 400 into the outdoor heat exchanger 200, which functions as a condenser, and the refrigerant flowing out of the outdoor heat exchanger 200 flows into the indoor heat exchanger 300 via the expansion valves 100 and 101, which functions as an evaporator.

On the other hand, during heating operation, as shown by the dashed arrows in Figure 9, the refrigerant compressed by the compressor 500 is circulated from the four-way valve 400 to the indoor heat exchanger 300, the expansion valves 101 and 100, the outdoor heat exchanger 200, the four-way valve 400, and finally the compressor 500, with the indoor heat exchanger 300 functioning as a condenser and the outdoor heat exchanger 200 functioning as an evaporator.

In addition, during heating operation, for example, only one of the multiple compressors 500 may be stopped due to a small heating load or other reasons. In this case, if the motor-operated valve 10 connected to the stopped compressor 500 is closed, the refrigerant will not flow, and since the flow from the side to the downward direction is stopped, there is little valve leakage in the motor-operated valve 10, and the refrigerant will flow into the stopped compressor 500. Depending on the conditions, for example, the refrigerant in a gas state will liquefy and be compressed into a liquid, which will not cause the compressor 500 to break down.

In addition, during cooling operation when all of the compressors 500 are operating, the main valve body 3 of the motor-operated valve 10 is fully open and the refrigerant flows only from below in a lateral direction, so there is no need to worry about valve leakage. Also, even during cooling operation, for example, only one of the compressors 500 may be stopped due to a small cooling load. In this case, if the motor-operated valve 10 connected to the stopped compressor 500 is closed, the refrigerant does not flow, and the flow from the side to the bottom is stopped, so there is little valve leakage from the motor-operated valve 10, and there is no risk of the refrigerant flowing into the stopped compressor 500 side, and depending on the conditions, the refrigerant in a gas state liquefies, and the compressor 500 breaks down due to liquid compression.

According to the refrigeration cycle system of the present invention, as described above, the motor-operated valve 10 of this embodiment can be made smaller. In addition, in the refrigeration cycle system shown as an example above, the second joint pipe 12 of the motor-operated valve 10 is connected to each of the multiple outdoor heat exchangers 200, and since there is little valve leakage, there is no unnecessary inflow of refrigerant to the compressor 500 side that is in a stopped state, and the system can be suitably used, for example, in a multi-air conditioner for a building.

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

For example, in the above example of the present invention, the motor-operated valve 10 is suitable for use in a multi-air conditioner for a building, but is not limited thereto and may also be used in a normal air conditioner or a refrigerator.

REFERENCE SIGNS LIST 10 Motor-operated valve 11 First joint pipe 11a Port on the tip side of the first joint pipe 12 Second joint pipe 12a Port on the tip side of the second joint pipe 1 Valve body 1C Main valve chamber 2 Sub-valve body 31 Sub-valve seat 3 Main valve body 13 Main valve seat 3C Sub-valve chamber 5 Stepping motor (drive unit)
R1 First flow passage R2 Second flow passage R3 Third flow passage S1, S2 Back pressure chamber 33 Chamfered surface 19 Valve guide hole 14 Flow passage forming member 14a Joint gap 100 Expansion valve 101 Expansion valve 200 Outdoor heat exchanger (condenser, evaporator)
300 Indoor heat exchanger (condenser, evaporator)
400 Four-way valve (flow path switching valve)
500 Compressor

Claims (5)

a sub-valve seat formed in a main valve chamber within the valve body; a main valve element movably supported on the valve body and attachable to and detachable from the main valve seat; a sub-valve seat formed in a sub-valve chamber within the main valve element; a sub-valve element attachable to and detachable from the sub-valve seat within the main valve element; and a drive section that drives the sub-valve element forward and backward to move it forward and backward to follow the main valve element, wherein an upper end of the sub-valve element abuts against the main valve element at a position away from the sub-valve seat, thereby lifting and moving the main valve element in an opening direction,
a back pressure chamber communicating with the sub valve chamber is provided on the opposite side of the main valve body from the main valve seat,
a flow path area A of a first flow path formed by a radial gap between a tapered outer surface of a needle portion of the sub-valve element and an inner port surface of the sub-valve seat in a state in which an upper end of the sub-valve element abuts against the main valve element and the main valve element is in a valve-closed state when the sub-valve element starts to move the main valve element in the opening direction, and a flow path area B of a second flow path communicating between the main valve chamber and the back pressure chamber are such that A>B;
an electrically operated valve, characterized in that the second flow path is provided in the gap between the outer peripheral surface of the main valve element at a portion with the largest outer diameter and a valve guide hole integrally formed in the valve body to move the main valve element in an opening/closing direction; a third flow passage is provided to communicate the main valve chamber with the sub-valve chamber,
the third flow path is formed by a through hole having an inner diameter dimension larger than a distance from the outer circumferential surface of the main valve element constituting the gap in which the second flow path is provided to the valve guide hole of the valve body,
2. The motor-operated valve according to claim 1, wherein a relationship between the flow passage area A, the flow passage area B, and a flow passage area C of the third flow passage is A>B+C. The motor-operated valve according to claim 1 or 2, characterized in that a sealing surface with the main valve seat is formed by chamfering the outer peripheral surface of the main valve body toward the inner peripheral surface. A refrigeration cycle system comprising the motor-operated valve according to any one of claims 1 to 3 . A refrigeration cycle system comprising a plurality of motor-operated valves according to any one of claims 1 to 3 , each of which is connected to an outdoor heat exchanger.

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