JP7462932B2 - 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 an expansion valve structure that suppresses the generation of refrigerant passing 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 noises (refrigerant passing noise, valve vibration noise) due to the refrigerant flowing through the valve, and various proposals have been made to reduce such abnormal noises.

For example, in the invention described in the following Patent Document 1, the valve body support member is provided with a vibration-proof spring, or the actuating rod is brought into contact with the actuating rod insertion hole, thereby suppressing the vibration of the valve body and actuating rod and preventing the generation of abnormal noise.

JP 2019-39579 A

The invention described in Patent Document 1 prevents abnormal noises from occurring in the refrigerant supply path to the evaporator, that is, the flow path from the inlet path through the valve chamber to the outlet path. However, abnormal noises from the expansion valve are not limited to those caused by the refrigerant passing through this path, and can also occur in the return flow path that passes through the refrigerant discharged from the evaporator.

Specifically, as shown in FIG. 6, the return flow path 23 supplies the refrigerant discharged from the evaporator to a drive unit 24 (e.g., a diaphragm device) provided on the upper surface of the valve body 12 so that the drive unit 24, which adjusts the opening degree of the valve, can detect the temperature and pressure of the refrigerant in the evaporator. For this reason, the return flow path 23 is formed directly below the drive unit 24 so as to pass horizontally through the valve body 12.

On the other hand, it is necessary to connect the actuating rod 19 that moves the valve body 15 to the driving part 24, and this actuating rod 19 is structured to cross the return flow passage 23 from top to bottom. For this reason, in the conventional expansion valve 1, the refrigerant flowing in the return flow passage 23 may collide with the actuating rod 19, causing the actuating rod 19 to vibrate, or the actuating rod 19 may disturb the flow of the refrigerant, causing abnormal noise.

Therefore, the object of the present invention is to prevent abnormal noise caused by the refrigerant flowing through the return flow path.

In order to solve the above problems and achieve the object, a first expansion valve according to the present invention is an expansion valve comprising: 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 body that changes a flow rate of the refrigerant by moving toward and away from the valve seat between a closed state in which it is seated on the valve seat and an open state in which it is separated from the valve seat; a biasing member that biases the valve body toward the valve seat; an actuating rod that is disposed inside the valve body and moves the valve body in the valve opening direction against the biasing force of the biasing member ; a drive unit that drives the actuating rod ; and a return flow path that allows the passage of refrigerant , wherein the drive unit is provided on an upper surface of the valve body, the return flow path passes horizontally through an upper part of the valve body and communicates with a lower surface of the drive unit, the actuating rod has an upper end connected to the drive unit and a lower end in contact with the valve body, and has a rod-like shape that extends linearly in the vertical direction from the upper end connected to the drive unit to the lower end in contact with the valve body, and the return flow path is arranged so that the actuating rod does not cross the return flow path.

In this application, the direction from the valve seat toward the actuator is referred to as "up", the direction from the actuator toward the valve seat is referred to as "down", and the direction perpendicular to the up and down directions is referred to as the "horizontal direction". Based on the concepts of "up" and "down", terms related to up and down, such as "upper and lower", "upper part", "lower part", "upper end", "lower end", "upper surface part", and "lower surface part", are used. However, since the expansion valve of the present invention (as well as the expansion valves of the embodiments described later) can be used in various orientations, "down" does not necessarily mean the direction of gravity and "up" does not necessarily mean the direction opposite to gravity.

A second expansion valve according to the present invention is an expansion valve comprising: a valve body having a valve chamber communicating with an inflow passage for introducing a refrigerant and an outflow passage for discharging the refrigerant; a valve body 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 body is seated on the valve seat and an open state in which the valve body is separated from the valve seat; a biasing member that biases the valve body toward the valve seat; an actuating rod that is disposed inside the valve body and moves the valve body in a valve opening direction against the biasing force of the biasing member; a drive unit that drives the actuating rod; and a return flow path that allows the passage of the refrigerant, the drive unit being disposed on an upper surface portion of the valve body. the return flow passage penetrates horizontally through the upper part of the valve body and is connected to the underside of the drive part, the upper end of the actuating rod is connected to the drive part and the lower end is in contact with the valve body, the return flow passage is arranged so that the actuating rod does not cross the return flow passage, and an actuating rod insertion hole is provided at the upper part of the valve body, extending in the vertical direction and communicating with the underside of the drive part, and having a diameter larger than that of the actuating rod and through which the actuating rod passes, and a communication passage is provided that connects the actuating rod insertion hole and the return flow passage to enable the flow of refrigerant between the actuating rod insertion hole and the return flow passage.

In the expansion valve of the present invention (the first and second expansion valves described above) , the working rod is positioned so as not to cross the return flow passage, so the refrigerant passing through the return flow passage does not collide directly (straight and with force) with the working rod. This makes it possible to prevent the refrigerant flowing through the return flow passage from colliding with the working rod and vibrating it, or to prevent the flow of refrigerant in the return flow passage from being disturbed by the working rod, thereby generating abnormal noise.

On the other hand, the return flow passage has a role of supplying refrigerant to the drive section (e.g., a diaphragm device) that operates the valve body via the actuation rod as described above so that the drive section can detect the temperature and pressure of the refrigerant at the evaporator outlet. Therefore, in the present invention, in order not to impair this function, the return flow passage and the drive section are also communicated so that the refrigerant can flow between the two (the return flow passage and the drive section).

As a more specific structure of the first expansion valve according to the present invention, for example, the following aspects are considered.

In a first aspect, the expansion valve has an actuating rod insertion hole that extends in the vertical direction at the upper part of the valve body, communicates with the underside of the drive part, and has a diameter larger than that of the actuating rod and through which the actuating rod passes, and the return flow path is connected to the actuating rod insertion hole by arranging the edge of the return flow path overlapping the edge of the actuating rod insertion hole.

In a second aspect, a communication passage is provided that connects the lower surface of the drive unit and the return flow passage to enable the circulation of the coolant between the lower surface of the drive unit and the return flow passage.

In addition, the refrigeration cycle device of the present invention is a refrigeration cycle device including 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 reduced in pressure and expanded by the expansion valve, wherein the expansion valve is the first expansion valve (including the first and second aspects) or the second expansion valve of the present invention described above.

The expansion valve of the present invention can prevent the generation of refrigerant passing noise caused by the refrigerant flowing through the return flow path.

Other objects, features, and advantages of the present invention will become apparent from the following description of the embodiments of the present invention based on the drawings. Note that the present invention is not limited to the following embodiments, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the claims. In addition, the same reference numerals in each drawing indicate the same or equivalent parts.

FIG. 1 is a vertical cross-sectional view showing an expansion valve according to a first embodiment of the present invention (cross-section taken along the line BB in FIG. 2). FIG. 2 is a vertical cross-sectional view showing the expansion valve according to the first embodiment (a cross-section taken along the line AA in FIG. 1). FIG. 3 is a vertical cross-sectional view similar to FIG. 1, showing an expansion valve according to a second embodiment of the present invention. FIG. 4 is a vertical cross-sectional view similar to FIG. 1, showing an expansion valve according to a third embodiment of the present invention. FIG. 5 is a conceptual diagram showing a refrigeration cycle device according to a fourth embodiment of the present invention. FIG. 6 is a vertical cross-sectional view similar to FIG. 1 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 and 2. Each figure shows two-dimensional orthogonal coordinates representing the up/down/left/right or up/down/front/back directions, and the following description will be based on these directions (the same applies to the second and third embodiments described below).

As shown in Figures 1 and 2, the expansion valve 11 according to the first embodiment of the present invention has a valve body 12 with a valve chamber 13 therein, an inflow passage 21 for introducing refrigerant into the valve chamber 13, an outflow passage 22 for discharging refrigerant from the valve chamber 13 through a throat 20, a valve body 15 that moves up and down within the valve chamber 13 to change the amount of refrigerant flowing into the valve chamber 13, a valve body support member 16 that supports the valve body 15 from below, and a valve seat 14 that allows the valve to be closed by the valve body 15 coming into contact with it.

The expansion valve 11 also has a spring receiving member 18 attached to the underside of the valve body 12 to seal the valve chamber 13, a coil spring (biasing member) 17 arranged between the spring receiving member 18 and the valve body support member 16 to bias the valve body 15 upward, an actuating rod 19 that moves the valve body 15 downward against the biasing force of the coil spring 17, a diaphragm device (drive unit) 24 provided on the upper surface of the valve body 12 to move the actuating rod 19 up and down, and a return flow path 23 that passes through the upper part of the valve body 12 to supply the refrigerant discharged from the evaporator 64 (see Figure 5 / the same below) to the diaphragm device 24 and allows the refrigerant to flow.

The inflow passage 21 and outflow passage 22 communicate with each other through the valve chamber 13, but in the closed state in which the valve body 15 abuts and seats on the valve seat 14 due to the upward biasing force of the coil spring 17, the inflow passage 21 and outflow passage 22 are not communicated and are in a blocked state. On the other hand, when the valve body 15 is pushed by the operating rod 19 and moves downward and away from the valve seat 14 (the state shown in Figures 1 and 2), the inflow passage 21 and outflow 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 inflow passage 21 is discharged outside the expansion valve 11 through the throat 20 and outflow passage 22. The discharged refrigerant is introduced into the evaporator 64. The flow rate of this refrigerant is adjusted by changing the vertical position of the valve body 15 (the distance between the valve body 15 and the valve seat 14).

The actuating rod 19 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 valve body 15. In order to position the actuating rod 19 in this manner, the valve body 12 is provided with an actuating rod insertion hole 31 that extends from the upper surface of the front end of the outflow passage 22 to which the throat portion 20 is connected to the upper surface of the valve body 12 to which the diaphragm device 24 is installed. Furthermore, this actuating rod insertion hole 31 has a large diameter enlarged portion 31a at the upper portion of the valve body 12 through which the return passage 23 passes, and this enlarged portion 31a is connected to the lower surface of the diaphragm device 24 (the second space 30 described later). Furthermore, an O-ring is attached to the lower end of the enlarged portion 31a of the actuating rod insertion hole 31 to ensure airtightness between the vicinity of the outflow passage 22 and the vicinity of the return passage 23. Furthermore, a ring-shaped vibration-proof spring may be attached to this portion to suppress the vibration that the actuating rod 19 receives from the valve body 15 through sliding resistance.

On the other hand, the return flow passage 23, which introduces the refrigerant discharged from the evaporator 64, extends horizontally (front to back) through the upper part of the valve body 12, and is arranged so that the edge of the return flow passage 23 overlaps with the edge of the enlarged diameter portion 31a of the actuating rod insertion hole 31 (see FIG. 1). In other words, compared to the conventional expansion valve (FIG. 6) described above, the return flow passage 23 in the conventional expansion valve 1 is arranged to pass through the center line C of the expansion valve 1 on which the actuating rod 19 is arranged, whereas in the expansion valve 11 of this embodiment, the return flow passage 23 is shifted horizontally (to the left in this embodiment, but it can also be to the right) from the center line C so as not to overlap with the actuating rod 19, and is arranged so that the edge of the return flow passage 23 and the edge of the enlarged diameter portion 31a intersect (overlap).

In the expansion valve 11 of this embodiment, due to this arrangement, a communication port 32 that communicates the return flow path 23 and the enlarged diameter portion 31a is formed at the intersection of the return flow path 23 and the enlarged diameter portion 31a, and the refrigerant in the return flow path 23 can enter the lower surface of the diaphragm device 24 through the enlarged diameter portion 31a through this communication port 32, thereby operating the diaphragm device 24. Moreover, unlike the conventional expansion valve 1, the refrigerant flowing straight through the return flow path 23 so as to pass through the valve body 12 does not directly collide with the operating rod 19, so the refrigerant passing through the return flow path 23 does not vibrate the operating rod 19 to generate abnormal noise, and the flow of refrigerant in the return flow path 23 is not disturbed by the operating rod 19 to generate abnormal noise.

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, a top 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 top cover member 26. A first space 29 surrounded by the top 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 19 is connected to the diaphragm 27 via the working rod receiving member 28. The diaphragm 27 is pulled up or pushed down depending on the difference between the pressure of the working gas in the first space 29 and the pressure of the refrigerant in the second space 30, and the expansion valve 11 is switched between the open and closed states.

The second space 30 between the diaphragm 27 and the dish-shaped member 25 is connected to the return flow passage 23 through the central opening of the dish-shaped member 25 described above, the enlarged diameter portion 31a of the working rod insertion hole 31, and the communication port 32. Therefore, the pressure and volume of the working gas in the first space 29 change depending on the temperature and pressure of the refrigerant flowing through the return flow passage 23, and the working rod 19 moves up and down 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 64 in response to the temperature and pressure of the refrigerant returning from the evaporator 64 to the expansion valve 11.

Second Embodiment
An expansion valve 41 according to a second embodiment of the present invention will be described with reference to Fig. 3. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and duplicated descriptions will be omitted, and differences will be mainly described (the same applies to a third embodiment described later).

In the expansion valve 41 according to the second embodiment of the present invention, as shown in FIG. 3, the return flow passage 23 is shifted horizontally so that the actuating rod 19 does not cross the return flow passage 23, as in the first embodiment. However, unlike the first embodiment, the enlarged diameter portion 31a of the actuating rod insertion hole 31 does not overlap with the return flow passage 23.

For this reason, in this embodiment, a communication passage 33 is provided that connects the return flow passage 23 and the enlarged diameter portion 31a, and the refrigerant in the return flow passage 23 flows into the enlarged diameter portion 31a through this communication passage 33. The refrigerant that flows into the enlarged diameter portion 31a is supplied to the underside portion (second space 30) of the diaphragm device 24, as in the expansion valve 11 of the first embodiment, and operates the diaphragm device 24.

Third Embodiment
4 shows an expansion valve according to a third embodiment of the present invention. As shown in this figure, an expansion valve 51 of this embodiment has an arrangement structure in which the return flow passage 23 is shifted horizontally so that the enlarged diameter portion 31a of the working rod insertion hole 31 does not overlap with the return flow passage 23, similar to the expansion valve 41 of the second embodiment, and is provided with a communication passage 33 through which the refrigerant in the return flow passage 23 can flow.

In contrast, in this embodiment, unlike the second embodiment, the communication passage 33 is directly connected to the underside of the diaphragm device 24. Therefore, the refrigerant in the return flow path 23 is supplied directly to the underside (second space 30) of the diaphragm device 24 without passing through the enlarged diameter portion 31a of the actuating rod insertion hole 31, and operates the diaphragm device 24.

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

As shown in FIG. 5, this refrigeration cycle device 61 includes a compressor 62 that compresses the refrigerant, a condenser 63 that cools and liquefies the refrigerant compressed by the compressor 62, an expansion valve 11 that reduces the pressure and expands the refrigerant liquefied by the condenser 63, and an evaporator 64 that evaporates the refrigerant reduced in pressure and expanded by the expansion valve 11. The expansion valve used is the expansion valve 11 described above in the first embodiment.

In this refrigeration cycle device 61, the refrigerant pressurized by the compressor 62 is liquefied by the condenser 63 and sent to the expansion valve 11. The refrigerant adiabatically expanded by the expansion valve 11 is sent to the evaporator 64, where it is heat exchanged with the air flowing around the evaporator 64. The refrigerant returning from the evaporator 64 is returned to the compressor 62 through the return flow path 23 of the expansion valve 11.

The expansion valve 11 is supplied with high-pressure refrigerant from the condenser 63. More specifically, the high-pressure refrigerant sent from the condenser 63 flows into the valve chamber 13 through the inlet passage 21. In the closed valve state in which the valve body 15 is pressed against the valve seat 14 by the coil spring 17 and seated, the inlet passage 21 and the outlet passage 22 do not communicate, and the refrigerant in the valve chamber 13 is not discharged from the expansion valve 11.

Meanwhile, when the actuating rod 19 moves downward against the biasing force of the coil spring 17, moving the valve body 15 downward and retracting the valve body 15 from the valve seat 14 (as shown in FIG. 5), the inlet passage 21 and the outlet passage 22 communicate (open valve state), and the refrigerant in the valve chamber 13 is discharged through the outlet passage 22 and sent to the evaporator 64. Such movement of the actuating rod 19 is performed by the diaphragm device 24 provided on the upper surface of the valve body 12, as described in the explanation of the first embodiment.

The refrigeration cycle device 61 of this embodiment uses the expansion valve 11 of the first embodiment, so it is possible to prevent abnormal noise caused by the refrigerant passing through the return flow path 23 and the actuating rod 19.

As the expansion valve, the expansion valves 41 and 51 of the second and third embodiments, or other expansion valves that can be constructed based on the present invention, can be used. In addition, in the expansion valves 11, 41, and 51 of this embodiment and the present invention and each embodiment, by combining the arrangement structure of the return flow path 23 based on the present invention with the vibration-proof structure such as the vibration-proof spring, the generation of abnormal noise from the expansion valve can be more effectively reduced.

REFERENCE SIGNS LIST 1, 11, 41, 51 Expansion valve 12 Valve body 13 Valve chamber 14 Valve seat 15 Valve body 16 Valve body support member 17 Coil spring (biasing member)
DESCRIPTION OF SYMBOLS 18 Spring receiving member 19 Actuating rod 20 Throat portion 21 Inflow passage 22 Outflow passage 23 Return passage 24 Diaphragm device 25 Dish-shaped member 26 Upper cover member 27 Diaphragm 28 Actuating rod receiving member 29 First space 30 Second space 31 Actuating rod insertion hole 31a Enlarged diameter portion 32 Communication port 33 Communication passage 61 Refrigeration cycle device 62 Compressor
63 Condenser
64 Evaporator

Claims (5)

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 element that moves toward and away from the valve seat between a closed state in which the valve element is seated on the valve seat and an open state in which the valve element is spaced from the valve seat to change a flow rate of the refrigerant;
a biasing member that biases the valve body toward the valve seat;
an actuating rod disposed inside the valve body and configured to move the valve body in a valve opening direction against the biasing force of the biasing member;
A drive unit that drives the operating rod;
and a return flow path that allows the refrigerant to pass through.
When the direction from the valve seat to the actuator is defined as "up", the direction from the actuator to the valve seat is defined as "down", and the direction perpendicular to the up and down directions is defined as the "horizontal direction",
The drive portion is provided on an upper surface portion of the valve body,
the return flow passage horizontally passes through an upper portion of the valve body and communicates with a lower surface portion of the drive portion,
The actuating rod has an upper end connected to the drive unit and a lower end in contact with the valve body, and has a rod-like shape extending linearly in the vertical direction from the upper end connected to the drive unit to the lower end in contact with the valve body,
An expansion valve, characterized in that the return flow passage is arranged so that the operating rod does not cross the return flow passage. an actuating rod insertion hole extending in the vertical direction at an upper portion of the valve body, communicating with a lower surface portion of the drive portion, having a diameter larger than that of the actuating rod and through which the actuating rod passes;
The expansion valve according to claim 1 , wherein an edge of the return flow passage overlaps an edge of the actuation rod insertion hole, thereby communicating the return flow passage with the actuation rod insertion hole. 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 element that moves toward and away from the valve seat between a closed state in which the valve element is seated on the valve seat and an open state in which the valve element is spaced from the valve seat to change a flow rate of the refrigerant;
a biasing member that biases the valve body toward the valve seat;
an actuating rod disposed inside the valve body and configured to move the valve body in a valve opening direction against the biasing force of the biasing member;
A drive unit that drives the operating rod;
a return flow path that allows the coolant to pass through;
An expansion valve comprising:
When the direction from the valve seat to the actuator is defined as "up", the direction from the actuator to the valve seat is defined as "down", and the direction perpendicular to the up and down directions is defined as the "horizontal direction",
The drive portion is provided on an upper surface portion of the valve body,
the return flow passage horizontally passes through an upper portion of the valve body and communicates with a lower surface portion of the drive portion,
The actuating rod has an upper end connected to the drive portion and a lower end in contact with the valve body,
Positioning the return passage such that the actuation rod does not cross the return passage;
An actuating rod insertion hole is provided at an upper portion of the valve body, the actuating rod insertion hole extending in the vertical direction and communicating with a lower surface portion of the drive portion, the actuating rod having a larger diameter than the actuating rod and through which the actuating rod passes,
a communication passage that connects the working rod insertion hole and the return flow passage to enable the refrigerant to flow between the working rod insertion hole and the return flow passage;
An expansion valve characterized by : The expansion valve according to claim 1 , further comprising a communication passage that connects a lower surface of the drive portion and the return flow passage to enable refrigerant to flow between the lower surface of the drive portion and the return flow passage. 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 4.

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