JP7482498B2 - Expansion valve and refrigeration cycle device - Google Patents

Description

The present invention relates to an expansion valve and a refrigeration cycle device, and in particular to a technology for suppressing valve vibration of an expansion valve provided in a refrigeration cycle of an air conditioner or the like, and preventing the generation of abnormal noise.

Refrigeration cycle devices such as car air conditioners are equipped with an expansion valve to fully utilize the capacity of the evaporator. This expansion valve responds to the refrigerant temperature in the evaporator's outlet piping and throttles the flow of refrigerant supplied to the evaporator to control the flow rate to an optimal level.

However, such expansion valves can generate abnormal noise due to the refrigerant flowing through the valve, and various proposals have been made to reduce such abnormal noise (see, for example, Patent Document 1 below).

JP 2019-11885 A

The invention described in the above-mentioned Patent Document 1 employs a structure in which the force pressing down on the valve support and actuating rod increases as the valve opening becomes smaller, enabling effective vibration control according to the valve opening. However, it requires the provision of a new vibration control spring, which increases the number of parts and therefore increases manufacturing costs. Furthermore, the increased number of parts also increases the number of assembly steps.

On the other hand, valve vibration is affected not only by the valve opening but also by the pressure of the refrigerant passing through the valve, and the higher the refrigerant pressure, the more likely the valve vibration will occur. However, the invention described in Patent Document 1 above aims to effectively suppress vibration from the perspective of the valve opening, and is not necessarily able to effectively suppress vibration in response to the refrigerant pressure.

The object of the present invention is therefore to suppress valve vibration without increasing the number of parts or manufacturing processes, and further to make it possible to increase the vibration suppression effect as the refrigerant pressure increases.

In order to solve the above problems and achieve the object, the expansion valve according to the present invention comprises a valve body having a valve chamber communicating with an inlet passage for introducing a refrigerant and an outlet passage for discharging the refrigerant, a valve part that changes the flow rate of the refrigerant by moving toward and away from the valve seat between a closed state in which the valve part is seated on the valve seat and an open state in which the valve part is spaced from the valve seat, and a valve body having a valve support part that supports the valve part within the valve chamber so that the valve part can move toward and away from the valve seat, a biasing member that biases the valve part toward the valve seat, an operating rod that contacts the valve part and moves the valve part in the valve opening direction against the biasing force of the biasing member, and a drive part that drives the operating rod.

When the movement direction of the working rod from the open state to the closed state is the upward direction, and when the movement direction of the working rod from the closed state to the open state is the downward direction, at least a part of the outer circumferential surface of the valve support part is in contact with the inner wall surface of the valve chamber so as to be slidable in the vertical direction, and supports the valve part so as to be movable in the vertical direction. The valve seat has an inlet which is an opening of the inflow passage on the valve chamber side, and the inlet opens into the valve chamber so that its edge faces diagonally downward. The valve part has an inclined surface facing diagonally upward so that the valve part can abut against the edge of the inlet to close the inlet when the valve part is seated on the valve seat. The valve body is disposed in the valve chamber so that the valve support part is pressed against the inner wall surface of the valve chamber by receiving a pressing force of the refrigerant flowing into the valve chamber from the inlet when the valve is in the open state. In the expansion valve according to the present invention, at least a part of the outer circumferential surface of the valve support part may be in contact with the inner wall surface of the valve chamber so as to be slidable in the vertical direction between the closed state and the maximum open state. In addition, the valve chamber may have a cylindrical middle portion, and the valve support portion may have a cylindrical shape extending downward from the lower edge of the valve portion and be fitted into the cylindrical middle portion of the valve chamber so as to be movable up and down.

In the expansion valve of the present invention, the valve body is disposed within the valve chamber so that it receives the flow of refrigerant flowing into the valve chamber from the inlet and is pushed by the flow of the refrigerant, and the valve support part is pressed against the inner wall surface of the valve chamber by the pressing force of the refrigerant. Therefore, the vibration of the valve support part and the valve part supported by it is suppressed by the pressing force of the refrigerant, and valve vibration can be suppressed without the need for a separate vibration-damping member such as the vibration-proof spring mentioned above, and it is possible to avoid an increase in the number of parts and manufacturing steps required to suppress valve vibration.

In addition, according to the present invention, which uses the flow of refrigerant (pressure) to suppress vibration, the higher the refrigerant pressure, the stronger the pressure applied to the valve support section, making it possible to effectively deal with valve vibration, which is more likely to occur when the refrigerant pressure is high.

In the present invention, it is typically the valve portion that receives the pressing force of the refrigerant directly, as in the following embodiment, and the pressing force of the refrigerant received by the valve portion is transmitted to the valve support portion, which presses the valve support portion against the wall surface inside the valve chamber. However, the pressing force of the refrigerant may be received by the valve support portion, or the structure may be such that both the valve portion and the valve support portion receive the pressing force.

In one aspect of the present invention, the valve portion has a frustum shape (e.g., a truncated pyramid shape or a truncated cone shape) or a pyramidal shape (e.g., a pyramidal shape or a truncated cone shape), and the inclined surface is part of the pyramidal surface (the peripheral surface of the frustum or pyramid). In this aspect, the valve portion may have a truncated pyramid shape, and the valve portion may be moved downward by contacting the lower end of the actuating rod with the upper bottom surface of the valve portion.

In the above embodiment, the valve portion may have a truncated pyramid shape having three or more pyramidal surfaces, and the three or more pyramidal surfaces may include a first pyramidal surface having a first inclination angle and a second pyramidal surface having a second inclination angle different from the first inclination angle.

According to this embodiment, it is possible to flexibly respond to variations in the inclination angle of the inlet facing diagonally downward within the manufacturing tolerance. That is, in the expansion valve of the present invention, the valve is closed by the inclined surface of the valve part abutting against the inclined inlet of the valve seat, so it is necessary to make the inclination angle of the inlet exactly match the inclination angle of the inlet. However, the inclination angle of the inlet may have variations (errors) within the manufacturing tolerance. Therefore, if the inclination angle of each of the multiple conical surfaces of the valve part is changed and the valve part is provided with multiple different inclined surfaces, it is possible to select the conical surface (inclined surface) that exactly matches the actual inclination angle of the inlet during assembly and incorporate the valve body into the valve body. In other words, if the orientation of the valve body is appropriately changed and the valve body is incorporated so that the conical surface (inclined surface) that exactly matches the actual inclination angle of the inlet faces the inlet, an expansion valve with high valve closing accuracy (no valve seat leakage) can be manufactured.

In another aspect of the present invention, a reduced diameter pipe member having a flow passage diameter smaller than that of the inlet passage and forming an inlet port may be provided at the end of the inlet passage on the valve chamber side.

According to this aspect, by preparing various diameter-reducing pipe members with different flow path cross-sectional areas (flow path diameters), the flow rate of the refrigerant flowing into (passing through) the expansion valve can be changed. Therefore, according to this aspect, the valve body can be standardized and expansion valves of various capacities can be constructed by simply changing the diameter-reducing pipe members, thereby reducing the cost of manufacturing expansion valves of various capacities.

In yet another aspect of the present invention, the inflow and outflow passages are formed in the valve body so as to extend substantially horizontally in the left-right direction perpendicular to the vertical direction (upward and downward), and the inflow opening and the outflow opening, which is the opening on the valve chamber side of the outflow passage, are positioned at substantially the same height in the vertical direction.

This aspect makes it possible to construct a low-profile expansion valve whose height dimension is smaller than that of the conventional expansion valve (see Figure 13 below).

The refrigeration cycle device according to the present invention is a refrigeration cycle device that includes a compressor that compresses a refrigerant, a condenser that cools and liquefies the refrigerant compressed by the compressor, an expansion valve that reduces the pressure and expands the refrigerant liquefied by the condenser, and an evaporator that evaporates the refrigerant that has been reduced in pressure and expanded by the expansion valve, and uses any of the expansion valves according to the present invention or aspects described above as the expansion valve.

The present invention makes it possible to suppress valve vibration without increasing the number of parts or manufacturing steps, and furthermore, the higher the refrigerant pressure, the greater the vibration damping force becomes.

Other objects, features, and advantages of the present invention will become apparent from the following description of the embodiments of the present invention, which are given with reference to the drawings. Note that the same reference numerals in each drawing indicate the same or corresponding parts.

FIG. 1 is a vertical cross-sectional view showing an expansion valve (open state) according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view (a cross-section taken along the line AA in FIG. 1) showing the main parts (the valve portion, the inlet port, and the outlet channel) of the expansion valve (in an open state) according to the first embodiment. FIG. 3 is a perspective view showing a valve body of the expansion valve according to the first embodiment. FIG. 4 is a perspective view showing a diameter-reducing pipe member of the expansion valve according to the first embodiment. FIG. 5 is a vertical cross-sectional view showing a lower part of the expansion valve (in a closed state) according to the first embodiment. FIG. 6 is a cross-sectional view (cross-section taken along the A1-A1 arrows in FIG. 5) similar to FIG. 2, showing an enlarged view of the main parts (valve portion, inlet port, and outlet path) of the expansion valve (closed state) according to the first embodiment. FIG. 7 is a cross-sectional view (corresponding to the cross section taken along the line A-A in FIG. 1) showing an enlarged view of the main parts (valve portion, inlet and outlet passage) of an expansion valve (open state) according to a second embodiment of the present invention, similar to FIG. 2. FIG. 8 is a perspective view showing a valve body of the expansion valve according to the second embodiment. FIG. 9 is a perspective view showing a diameter-reducing pipe member of the expansion valve according to the second embodiment. FIG. 10 is a vertical cross-sectional view showing an expansion valve (open state) according to a third embodiment of the present invention. Figure 11 is a cross-sectional view (cross-section taken along the line B-B in Figure 10) showing an enlarged view of the main parts (valve portion, inlet and outlet path) of the expansion valve (open state) of the third embodiment, similar to Figures 2 and 7. FIG. 12 is a conceptual diagram showing a refrigeration cycle device according to a fourth embodiment of the present invention. FIG. 13 is a vertical cross-sectional view showing an example of a conventional expansion valve.

First Embodiment
A first embodiment of the present invention will be described with reference to Figures 1 to 6. Each figure shows two-dimensional orthogonal coordinates representing each of the up, down, left, right, or front, back, left, and right directions, or three-dimensional orthogonal coordinates representing each of the up, down, front, back, left, and right directions, and the following description will be based on these directions.

As shown in Figs. 1 to 6, the expansion valve 11 according to the first embodiment of the present invention comprises a valve body 12 having a valve chamber 13 therein, an inflow passage 21 for introducing a refrigerant into the valve chamber 13, an outflow passage 22 for discharging the refrigerant from the valve chamber 13, a return passage 23 for circulating the refrigerant so as to pass through the upper part of the valve body 12 from left to right, a valve element 15 for changing the amount of refrigerant flowing into the valve chamber 13 by moving up and down within the valve chamber 13, and a valve element 15 for closing the valve by abutting against the valve element 15. It has a valve seat 14 (which blocks the inflow of refrigerant into the valve chamber 13), a spring receiving member 17 attached to the underside of the valve body 12 to seal the valve chamber 13, a coil spring (biasing member) 16 arranged between the spring receiving member 17 and the valve body 15 to bias the valve body 15 upward, an operating rod 18 that moves the valve body 15 downward against the biasing force of the coil spring 16, and a diaphragm device (drive unit) 24 provided on the upper surface of the valve body 12 to move the operating rod 18 up and down. The operation of the return flow path 23 and the diaphragm device 24 will be described in detail in the fourth embodiment described later, in which the expansion valve 11 of this embodiment is used.

The valve seat 14 is formed by a reduced diameter pipe member 20 installed at the end of the inflow passage 21 on the valve chest side. Specifically, the reduced diameter pipe member 20 is a tubular member that narrows the flow passage cross section of the inflow passage 21, and has a flow passage that extends horizontally (in the left-right direction) with a diameter smaller than the diameter of the base end (right side part) of the inflow passage 21. The valve seat 14 is formed by cutting out the tip surface (left end surface) of the reduced diameter pipe member 20 at an angle. This valve seat 14 is an inclined plane that faces diagonally downward to the left (in other words, has an upward slope toward the tip), and the above-mentioned flow passage of the reduced diameter pipe member 20 is opened to this valve seat 14 to form the inflow port 21a referred to in the present invention. Therefore, like the valve seat 14, the inflow port 21a also has an opening with its edge facing diagonally downward to the left, and the inclined surface 31a of the valve portion 15a described later abuts against the valve seat 14, blocking the inflow port 21a and closing the valve.

If multiple types of reduced diameter pipe members 20 with different flow path diameters are prepared, it is possible to manufacture various expansion valves 11 with different capacities while using a common valve body 12 by changing the reduced diameter pipe member 20 to be incorporated into the valve body 12.

The valve body 15 is composed of a valve portion 15a that abuts (seats) on the valve seat 14 to close the inlet 21a, and a valve support portion 15b that is provided at the bottom of the valve portion 15a and supports the valve portion 15a so that it can move up and down. The valve portion 15a has a quadrangular pyramid shape and has four pyramid faces 31a, 31b, 31c, and 31d that face diagonally upward (diagonally upward to the right, diagonally upward to the front, diagonally upward to the left, and diagonally upward to the rear). Of these pyramid faces 31a to 31d, the pyramid face 31a that faces diagonally upward to the right is used as the inclined face referred to in the present invention. In other words, the pyramid face (inclined face) 31a has the same inclination angle as the valve seat 14, and when the valve body 15 moves upward, the inclined face 31a abuts (seats) on the valve seat 14, and the inlet 21a is blocked.

The four cone surfaces 31a-31d of the valve portion 15a may have different inclination angles. This is to make it possible to use the cone surfaces 31a-31d that match the actual inclination angle of the valve seat 14 machined during manufacturing as the inclined surfaces. In other words, the inclination angle of the valve seat 14 (the tip surface of the reduced diameter tube member 20) may have an error within the manufacturing tolerance. If such an error occurs, when assembling the valve element 15 into the valve body 12, a cone surface having an inclination angle that is most similar (matches) the actual inclination angle of the valve seat 14 from among the four cone surfaces 31a-31d is selected, and the valve element 15 is installed in the valve body 12 so that the cone surface faces the valve seat 14. This makes it possible to manufacture an expansion valve 11 with higher valve closing accuracy (no valve seat leakage).

The valve support portion 15b has a cylindrical shape that extends downward from the lower edge of the valve portion 15a, and is fitted into the middle part of the cylindrical valve chamber so as to be movable up and down. In other words, the outer circumferential surface of the valve support portion 15b is in sliding contact with the inner wall surface 13a of the valve chamber 13, and the valve body 15 is provided so as to be able to move up and down within the valve chamber 13 like a piston that moves up and down within a cylinder. In addition, the upper end of the coil spring 16 is inserted from the bottom of the valve support portion 15b, and the valve body 15 is urged upward by the coil spring 16.

The actuating rod 18 that opens and closes the expansion valve 11 extends vertically inside the valve body 12, with its upper end connected to the diaphragm device 24 and its lower end in contact with the upper surface (upper bottom surface) 32 of the valve section 15a.

The inflow passage 21 and outflow passage 22 communicate with each other via the valve chamber 13, but in the closed valve state (as shown in Figures 5 and 6) in which the valve body 15 (valve portion 15a) is seated against the valve seat 14 by the upward biasing force of the coil spring 17, the inflow passage 21 and outflow passage 22 are not connected to each other and are in a blocked state.

On the other hand, when the valve body 15 is pushed downward by the actuation rod 18 and the valve portion 15a separates from the valve seat 14 (as shown in Figures 1 and 2), the inlet 21a opens, the inlet passage 21 and the outlet passage 22 communicate with each other, and the refrigerant that flows into the inside of the valve chamber 13 from the inlet 21a through the inlet passage 21 is discharged from the outlet passage 22 through the outlet passage 22 from the outlet 22, which is the end of the outlet passage 22 on the valve chamber side. The discharged refrigerant is introduced into the evaporator 64 (see Figure 12 described later). The flow rate of the refrigerant is adjusted by changing the vertical position of the valve body 15 and changing the distance between the valve body 15 (the inclined surface 31a of the valve portion 15a) and the valve seat 14 (the inlet 21a).

In addition, in this embodiment (similar to the second to fourth embodiments described below/similar below), in the open valve state, the refrigerant flowing into the valve chamber 13 from the inlet 21a collides with the valve portion 15a, and the flow of the refrigerant pushes the valve body 15 to the side (left), and the valve support portion 15b is pressed against the inner wall surface 13a on the outlet side of the valve chamber 13. Therefore, the pressing force of the refrigerant suppresses the vibration of the valve body 15. Furthermore, since the pressing force applied to the valve body 15 becomes stronger as the refrigerant pressure increases, it is possible to effectively deal with valve vibration, which is more likely to occur as the refrigerant pressure increases.

In addition, according to this embodiment, the inflow passage 21 and the outflow passage 22 can be arranged horizontally and at approximately the same height position across the valve chamber 13, so that a low-profile expansion valve 11 with a low height can be constructed. To go further with this point, as shown in FIG. 13, in a conventional expansion valve 61, the valve seat 14 is formed on the outflow port 22a side rather than the inflow port 21a side, and the valve seat 14 and the valve body 15a are arranged to face each other vertically in the up-down direction, and the valve chamber 13 and the outflow passage 22 communicate with each other through the throat portion 60 extending vertically upward from the valve seat 14. Therefore, the inflow passage 21 and the outflow passage 22 cannot be arranged at the same height position, and the height dimension of the expansion valve 61 must be increased by at least the difference in height between the two passages 21 and 22 (the length of the throat portion 60) h. In contrast, according to the present invention or embodiment, in which the inclined surface 31a of the valve portion 15a sits obliquely on the inclined valve seat 14 on the inlet 21 side, the throat portion 60 is unnecessary, and the inflow passage 21 (inlet 21a) and the outflow passage 22 (outlet 22a) can be located at the same height across the valve chamber 13, making it possible to construct a low-profile expansion valve 11.

Furthermore, in the conventional expansion valve 61, the refrigerant rises vertically through the throat 60, enters the horizontal outflow passage 22 from the outlet 22a, and collides vertically with the ceiling surface of the outflow passage 22 above the outlet, which makes it easy for the bubbles contained in the refrigerant to burst and generate abnormal noises (explosive sounds). In contrast, according to the expansion valve 11 of the present invention or embodiment, the refrigerant passes smoothly through the inflow passage 21, valve chamber 13, and outflow passage 22, which are arranged horizontally, so that the bubbles that may be contained in the refrigerant are less likely to burst than in the conventional expansion valve 61, and the bursting sounds of the bubbles can also be reduced. In addition, in the expansion valve 11 of the present invention or embodiment, the refrigerant collides with the valve portion 15a, but compared to the case where the refrigerant collides vertically with the ceiling surface of the outflow passage 22 as in the conventional expansion valve 61, the impact is smaller because the refrigerant collides obliquely with the inclined surface of the valve portion 15a, and the bubbles are less likely to burst.

Second Embodiment
An expansion valve according to a second embodiment of the present invention will be described with reference to Figures 7 to 9. Note that the same components as those in the first embodiment are given the same reference numerals, and duplicated descriptions will be omitted, and the following description will focus on the differences. In addition, since the longitudinal cross-sectional view of the expansion valve of this embodiment is the same as that of the first embodiment (Figure 1), reference will also be made to Figure 1 as appropriate.

As shown in Figures 1 and 7 to 9, the expansion valve 11 according to the second embodiment of the present invention is similar to the first embodiment in that it has a reduced diameter pipe member 20 forming the valve seat 14 at the tip end (the end on the valve chamber 13 side) of the inflow passage 21, and has a valve body 15 consisting of a valve portion 15a and a valve support portion 15b, but the valve portion 15a has a truncated cone shape. Therefore, the inclined surface 31a that blocks the inflow port 21a is a curved convex surface as part of the cone surface, and the valve seat 14 is a curved concave surface corresponding to this.

The valve body 15 is installed in the valve chamber 13 so as to be movable up and down, and when it is pushed downward by the actuating rod 18 against the biasing force of the coil spring 16, the inlet 21a opens, and the valve is in an open state (the state shown in Figs. 1 and 7). At this time, the valve support part 15b is pressed against the inner wall surface 13a on the outlet 22a side of the valve chamber 13 by the pressing force of the refrigerant flowing into the valve chamber 13 from the inlet 21a, suppressing valve vibration. In addition, the vertical position of the valve body 15 is changed, and the flow rate of the refrigerant is adjusted by changing the distance between the valve body 15 (inclined surface 31a of the valve part 15a) and the valve seat 14 (inlet 21a).

On the other hand, when the actuating rod 18 rises and the valve body 15 is pushed upward by the force of the coil spring 16, the inclined surface 31a of the valve portion 15a abuts (seats) against the valve seat 14, blocking the inlet 22a and closing the valve.

Third Embodiment
An expansion valve according to a third embodiment of the present invention will be described with reference to Figures 10 and 11. This embodiment includes a valve body 15 having the same shape and structure as the second embodiment (Figure 8), but the valve seat 14 is formed by processing the valve body 12 (the inner wall surface of the valve chamber 13) without using a diameter-reducing tube member 20 to form the valve seat 14.

Specifically, a cone-shaped inclined (facing diagonally downward) curved surface is formed on the upper part of the inflow passage 21a side of the valve chamber 13, and this curved surface is the valve seat 14. The valve seat 14 is formed with an inflow port 21a, which is the opening of the inflow passage 21 to the valve chamber 13. The end of the inflow passage 21 on the valve chamber 13 side is provided with a small diameter section 21b that narrows the flow path diameter, and the tip of the small diameter section 21b is the inflow port 21a. As in each of the above embodiments, when the valve part 15a is seated on the valve seat 14, the inflow port 21a is blocked by the inclined surface 31a of the valve part 15a, and the expansion valve 41 is in a closed state. In addition, in the open state (the state shown in Figures 10 to 11), the valve support part 15b is pressed against the inner wall surface 13a on the outlet port 22a side of the valve chamber 13 by the pressing force of the refrigerant flowing into the valve chamber 13 from the inflow port 21a, and valve vibration is suppressed.

Fourth Embodiment
A refrigeration cycle apparatus using the expansion valve 11 of the first embodiment will be described as a fourth embodiment of the present invention.

As shown in FIG. 12, this refrigeration cycle device 51 includes a compressor 52 that compresses the refrigerant, a condenser 53 that cools and liquefies the refrigerant compressed by the compressor 52, an expansion valve 11 that reduces the pressure and expands the refrigerant liquefied by the condenser 53, and an evaporator 54 that evaporates the refrigerant reduced in pressure and expanded by the expansion valve 11, and uses the expansion valve 11 according to the first embodiment as the expansion valve.

In this refrigeration cycle device 51, the refrigerant pressurized by the compressor 52 is liquefied by the condenser 53 and sent to the expansion valve 11. The refrigerant adiabatically expanded by the expansion valve 11 is sent to the evaporator 54, where it is heat exchanged with the air flowing around the evaporator 54. The refrigerant returning from the evaporator 54 is returned to the compressor 52 through the return flow path 23 of the expansion valve 11.

The expansion valve 11 is supplied with high-pressure refrigerant from the condenser 53. More specifically, the high-pressure refrigerant sent from the condenser 53 flows through the inlet 21a through the inflow passage 21 and the reduced diameter pipe member 20 into the valve chamber 13. When the valve body 15 (valve portion 15a) is pressed against the valve seat 14 by the coil spring 16 and is seated in a closed valve state, the inlet 21a is blocked and the inlet passage 21 and the valve chamber 13 are not in communication, so the refrigerant in the valve chamber 13 is not discharged from the expansion valve 11.

Meanwhile, when the actuating rod 18 moves downward against the biasing force of the coil spring 16, moving the valve body 15 downward and the valve portion 15a (inclined surface 31a) retreating from the valve seat 14, the valve chamber 13 and the inlet passage 21 are in communication (valve open state), and the refrigerant in the valve chamber 13 is discharged through the outlet passage 22 and sent to the evaporator 54. Such movement of the actuating rod 18 is performed by the diaphragm device 24 provided on the upper surface of the valve body 12.

The diaphragm device 24 has a dish-shaped member 25 with an opening in the center, fixed to the upper surface of the valve body 12, an upper cover member 26 that covers the upper surface of the dish-shaped member 25, and a diaphragm 27 arranged between the dish-shaped member 25 and the upper cover member 26. A first space 29 surrounded by the upper cover member 26 and the diaphragm 27 is filled with working gas. A working rod receiving member 28 is fixed to the lower surface of the diaphragm 27, and the upper end of the working rod 18 is connected to the diaphragm 27 via the working rod receiving member 28. When the working gas in the first space 29 is liquefied, the working rod 18 is pulled upward by the diaphragm 27, and when the liquefied working gas is vaporized, the working rod 18 is pushed downward by the diaphragm 27. In this way, the expansion valve 11 is switched between the open state and the closed state.

The second space 30 between the diaphragm 27 and the dish-shaped member 25 is connected to the return flow path 23 through the central opening of the dish-shaped member 25 described above. Therefore, the phase of the working gas in the first space 29 (gas phase or liquid phase) changes depending on the temperature and pressure of the refrigerant flowing through the return flow path 23, and the actuating rod 18 is driven in response to this change. In this way, the expansion valve 11 automatically adjusts the amount of refrigerant supplied from the expansion valve 11 to the evaporator 54 in response to the temperature and pressure of the refrigerant returning from the evaporator 54 to the expansion valve 11.

In addition, the refrigeration cycle device 51 of this embodiment uses the expansion valve 11 of the first embodiment, so valve vibration can be suppressed without a separate vibration-damping member such as a vibration-proof spring, and abnormal noise can be prevented from being generated from the expansion valve 11. In addition, it is possible to effectively deal with valve vibration, which is more likely to occur when the refrigerant pressure is higher.

The above describes the embodiments of the present invention, but the present invention is not limited to these, and it will be clear to those skilled in the art that various modifications can be made within the scope of the claims.

For example, in the refrigeration cycle device according to the fourth embodiment, the expansion valve 11 of the first embodiment is used, but it is of course possible to use the expansion valve of the second or third embodiment instead, and it is also possible to use other expansion valves that can be constructed based on the present invention in addition to the expansion valves of these embodiments. In addition, the present invention is preferably applied to car air conditioners and can contribute to improving the quietness inside the vehicle cabin, but the uses and applications are not limited to car air conditioners, and it can be applied to various other refrigeration cycle devices such as room air conditioners and freezers.

REFERENCE SIGNS LIST 11, 41, 51, 61 Expansion valve 12 Valve body 13 Valve chamber 13a Inner wall surface of valve chamber 14 Valve seat 15 Valve body 15a Valve portion 15b Valve support portion 16 Coil spring (biasing member)
17 Spring receiving member 18 Actuating rod 20 Reduced diameter tube member 21 Inflow path 21a Inflow port 21b Small diameter section 22 Outflow path 22a Outflow port 23 Return flow path 24 Diaphragm device 25 Dish-shaped member 26 Upper cover member 27 Diaphragm 28 Actuating rod receiving member 29 First space 30 Second space 31a Cone surface (inclined surface)
31b, 31c, 31d Cone surface 32 Upper surface (upper bottom surface) of valve portion
51 Refrigeration cycle device 52 Compressor
53 Condenser
54 Evaporator
60 Throat

Claims (9)

a valve body having a valve chamber communicating with an inlet passage for introducing a refrigerant and an outlet passage for discharging the refrigerant;
a valve portion that changes a flow rate of the refrigerant by moving toward and away from the valve seat between a closed state in which the valve portion is seated on the valve seat and an open state in which the valve portion is spaced from the valve seat, and a valve body having a valve support portion that supports the valve portion in the valve chamber so that the valve portion can move toward and away from the valve seat;
a biasing member that biases the valve portion toward the valve seat;
an actuation rod that comes into contact with the valve portion and moves the valve portion in a valve opening direction against the biasing force of the biasing member;
A drive unit that drives the operating rod,
When the movement direction of the working rod from the open state to the closed state is the upward direction and the movement direction of the working rod from the closed state to the open state is the downward direction,
the valve support portion has at least a portion of an outer circumferential surface that is in vertical slidable contact with an inner wall surface of the valve chamber and supports the valve portion so as to be vertically movable;
the valve seat has an inlet which is an opening of the inlet passage on the valve chest side,
the inlet opens into the valve chamber with its edge facing obliquely downward;
the valve portion has an inclined surface facing obliquely upward so as to come into contact with an edge of the inlet and close the inlet when the valve portion is seated on the valve seat,
an expansion valve including a valve support portion and a valve disc disposed in the valve chamber such that, when the valve is in an open state, the valve disc receives a pressing force of the refrigerant flowing into the valve chamber from the inlet, thereby pressing the valve support portion against an inner wall surface of the valve chamber. The expansion valve according to claim 1 , wherein the at least a portion of the outer circumferential surface of the valve support portion abuts against the inner wall surface of the valve chamber so as to be slidable in the up-down direction between the valve closed state and the maximum valve open state. The valve chamber has a cylindrical intermediate portion,
The valve support portion is
A cylindrical shape extending downward from a lower edge of the valve portion,
The expansion valve according to claim 1 or 2, wherein the valve chamber is fitted in a cylindrical middle portion of the valve chamber so as to be movable up and down. The valve portion has a frustum or cone shape,
The expansion valve according to claim 1 , wherein the inclined surface is a part of a cone surface. The valve portion has a quadrangular pyramid shape,
The expansion valve according to claim 4, wherein the valve portion can be moved downward by contacting a lower end of the actuating rod with an upper bottom surface of the valve portion. The valve portion has a truncated pyramid shape having three or more pyramidal faces,
The three or more conical surfaces are
a first pyramidal surface having a first tilt angle;
The expansion valve according to claim 4 or 5, further comprising: a second conical surface having a second inclination angle different from the first inclination angle. The expansion valve according to claim 1 , further comprising a reduced diameter pipe member having a flow passage diameter smaller than that of the inlet passage and forming the inlet port, the reduced diameter pipe member being provided at an end of the inlet passage on a valve chamber side. The inflow passage and the outflow passage are formed in the valve body so as to extend substantially horizontally in a left-right direction perpendicular to the upward and downward directions,
The expansion valve according to claim 1 , wherein the inlet and an outlet which is an opening of the outlet passage on the valve chest side are disposed at substantially the same height position in the up-down direction. A compressor that compresses a refrigerant;
a condenser that cools and liquefies the refrigerant compressed by the compressor;
an expansion valve for reducing the pressure and expanding the refrigerant liquefied in the condenser;
an evaporator that evaporates the refrigerant that has been decompressed and expanded by the expansion valve,
A refrigeration cycle device, wherein the expansion valve is the expansion valve according to any one of claims 1 to 8.

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