KR102105837B1 - Thermal expansion valve of air conditioning system for vehicle - Google Patents

Abstract

The present invention relates to an expansion valve of an air conditioning system for a vehicle, and more specifically, to include a ball valve that opens and closes a throttle passage formed between an inflow passage through which refrigerant transferred from a condenser flows in and an outflow passage through which the expanded refrigerant flows into an evaporator. An expansion valve of an air conditioning system for a vehicle, comprising: a temperature sensing unit disposed on an upper portion of the ball valve and sealed by an upper diaphragm and a lower diaphragm; A valve rod having an upper end connected to the lower diaphragm, a lower end contacting a ball valve, and movable up and down according to vertical deformation of the lower diaphragm; A first refrigerant passage disposed on the upper portion of the temperature sensing unit and discharging the refrigerant transferred from the evaporator to a compressor; And a second refrigerant flow path disposed below the temperature sensing unit and discharging the refrigerant transferred from the evaporator to a compressor. And, the refrigerant discharged from the evaporator relates to an expansion valve for an air conditioning system for a vehicle, characterized in that it is branched up and down and transferred to a first refrigerant passage and a second refrigerant passage.

Description

Expansion valve for vehicle air conditioning system {THERMAL EXPANSION VALVE OF AIR CONDITIONING SYSTEM FOR VEHICLE}

The present invention relates to an expansion valve of an air conditioning system for a vehicle, and more specifically, the refrigerant discharged from the evaporator is branched and passed through the first refrigerant flow passage and the second refrigerant flow passage respectively disposed at the upper and lower portions of the temperature sensing part to expand. It relates to an expansion valve of an air conditioning system for a vehicle that can prevent pipe freezing due to malfunction of a valve and improve performance degradation.

In general, the vehicle air conditioning system maintains the temperature inside the vehicle in a proper state regardless of the change in the outside temperature, and properly maintains the humidity and air environment inside the vehicle according to the driver's demands to provide a more convenient and comfortable environment for the driver. Is used.

As shown in Figure 1, the vehicle air conditioning system is a compressor (compressor) for compressing the refrigerant, a condenser (condenser) for condensing the compressed refrigerant to liquefy it, an expansion valve to adiabatic expansion of the liquefied refrigerant to a low-temperature, low-pressure refrigerant (Thermal eXpansion Valve, TXV) and an evaporator that evaporates the expanded refrigerant. In each step, the refrigerant is phase-changed into a gas of high temperature and high pressure, a liquid of normal temperature and high pressure, a liquid of low temperature and low pressure, and a gas of low temperature and low pressure, respectively.

In the compression step, the refrigerant in the gas phase is compressed by the adiabatic compression of the compressor, thereby increasing the temperature and pressure of the refrigerant. The high temperature and high pressure gas has a high condensation temperature and can be easily liquefied by ambient air at room temperature, and according to a water cooling type, it can be liquefied with water at room temperature.

Meanwhile, the refrigerant condensed in the condensation step is phase-changed into a liquid at room temperature and high pressure and flows into the expansion valve. The refrigerant flowing into the expansion valve undergoes irreversible isoenthalpy change in the expansion valve, and the pressure of the liquid at room temperature and high pressure drops rapidly due to the orifice effect as it passes through the narrow throttle passage.

In the vehicle air conditioning system, the ultimate purpose of the refrigeration cycle is to cool the inside of the vehicle. To this end, in the final evaporation step, the refrigerant passes through the evaporator to absorb heat from the surrounding air and vaporize it to form cold air to increase the temperature inside the vehicle. Lowers.

In such an air conditioning system for a vehicle, a conventional expansion valve is configured as follows.

As shown in FIG. 2, the expansion valve of the conventional air conditioning system for a vehicle includes an inflow passage 1 through which refrigerant transferred from a condenser flows, a throttle passage 2 for throttling the introduced refrigerant, and an expanded refrigerant. The outlet flow path (3) to be sent to the evaporator, the upper end is connected to the diaphragm (5), the ball valve (7) is coupled to the bottom, and the valve rod (6) is movable up and down, and a refrigerant flow path that delivers refrigerant discharged from the evaporator to the compressor (4).

The conventional expansion valve serves to automatically adjust the flow rate of the refrigerant flowing from the condenser to the evaporator by sensing the temperature (superheat) of the refrigerant flowing from the outlet of the evaporator toward the compressor.

Specifically, when the superheat degree is high, the pressure at the top of the diaphragm 5 becomes higher than the outlet pressure of the evaporator, and accordingly, the valve rod 6 descends to open the ball valve 7 and the throttle passage 2 as the ball valve opens. The flow rate of the refrigerant passing through is increased, thereby reducing the degree of superheat.

Conversely, when the degree of superheat is low, the pressure at the top of the diaphragm 5 is lower than the outlet pressure of the evaporator, and accordingly, the valve rod 6 rises to close the ball valve 7 and the throttle flow path as the ball valve is closed ( 2) The flow rate of the refrigerant passing through is reduced, thereby increasing the degree of superheat.

However, in the case of a conventional expansion valve mounted downward on an actual vehicle, as foreign matter (such as refrigerant) accumulates under the diaphragm, the temperature sensing sensitivity of the diaphragm decreases, resulting in a problem that the low pressure piping freezes or the performance of the air conditioning system deteriorates.

That is, even though the superheat degree is high, the sensitivity of the diaphragm decreases, and the ball valve cannot be sufficiently opened. Accordingly, there is a problem that the cooling efficiency decreases because the flow rate of the refrigerant flowing through the throttle passage is insufficient.

In addition, even if the superheat degree is low, the diaphragm does not function properly, so the ball valve cannot be sufficiently closed, and accordingly, the flow rate decrease of the refrigerant passing through the throttle passage decreases, so that the refrigerant does not evaporate completely in the evaporator and continuously evaporates in the low pressure pipe There is a problem of freezing low pressure piping.

Furthermore, a variety of problems occur due to poor automatic control of the flow rate of the refrigerant in the expansion valve, such as the liquid refrigerant that has not been evaporated even in the low pressure piping flows into the compressor and damages the compressor.

The present invention has been devised to solve the problems of the prior art described above, and is configured to allow the refrigerant discharged from the evaporator to branch and pass through the first refrigerant passage and the second refrigerant passage respectively disposed on the upper and lower portions of the temperature sensing unit. By doing so, an object of the present invention is to provide an expansion valve for an air conditioning system for a vehicle, which has improved piping freezing and performance degradation due to malfunction of the expansion valve.

In addition, another object of the present invention is to provide an expansion valve for an air conditioning system for a vehicle, which can freely change a piping layout of an air conditioning system for a vehicle by allowing a designer to freely change the piping layout of a vehicle air conditioning system even if the expansion valve is mounted horizontally or downwardly have.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by a person having ordinary knowledge in the art from the description of the present invention. .

The configuration of the present invention for achieving the above object, a vehicle air conditioning system including a ball valve for opening and closing a throttle passage formed between the inlet flow path through which the refrigerant transferred from the condenser flows in and the outlet flow path that sends the expanded refrigerant to the evaporator. In the expansion valve of the, the ball valve is disposed on the upper portion and the temperature sensitive portion sealed by the upper diaphragm and the lower diaphragm; A valve rod having an upper end connected to the lower diaphragm, a lower end contacting a ball valve, and movable up and down according to vertical deformation of the lower diaphragm; A first refrigerant passage disposed on the upper portion of the temperature sensing unit and discharging the refrigerant transferred from the evaporator to a compressor; And a second refrigerant flow path disposed below the temperature sensing unit and discharging the refrigerant transferred from the evaporator to a compressor. It includes, and the refrigerant discharged from the evaporator is characterized in that it is branched up and down and transferred to the first refrigerant passage and the second refrigerant passage.

In addition, the expansion valve of the vehicle air conditioning system according to an embodiment of the present invention, the upper end is connected to the valve body and the lower end is connected to the upper diaphragm; Further comprising, it is preferable that the shaft transfers the temperature of the refrigerant passing through the first refrigerant passage to the temperature-sensitive portion to expand or contract the temperature-sensitive portion.

In addition, in the expansion valve of the vehicle air conditioning system according to the embodiment of the present invention, the upper end of the shaft is fixed between the valve body and the fixing nut by tightening the fixing nut disposed on the upper portion, and an O-ring is provided on the outer circumferential surface of the fixing nut. It is preferably inserted.

In addition, in the expansion valve of the air conditioning system for a vehicle according to an embodiment of the present invention, the pressure of the refrigerant passing through the first refrigerant passage or the second refrigerant passage and the elastic force of the spring disposed under the ball valve are applied to the expansion valve of the vehicle air conditioning system. If it is relatively larger than the added value, it is preferable that the valve rod is moved downward to open the throttle passage.

Further, in the expansion valve of the air conditioning system for a vehicle according to an embodiment of the present invention, the pressure inside the temperature sensing unit passes the pressure of the refrigerant passing through the first refrigerant passage or the second refrigerant passage and the elastic force of the spring disposed under the ball valve. If it is relatively smaller than the added value, it is preferable that the valve rod is moved upward to close the throttle passage.

In the present invention having the above configuration, the refrigerant discharged from the evaporator through the first refrigerant passage and the second refrigerant passage respectively formed in the upper and lower portions of the thermosensitive portion sealed by the upper diaphragm and the lower diaphragm, the refrigerant is vertically moved up and down. By being configured to be branched and delivered, either the upper diaphragm or the lower diaphragm has the effect of allowing the expansion valve to function even if the sensitivity of temperature sensing is reduced by foreign matter.

For example, when the performance of the lower diaphragm deteriorates due to the accumulation of foreign substances in the lower diaphragm, the valve rod can be moved up and down by sensing or overheating the upper diaphragm to expand or contract the temperature sensing unit.

At this time, the shaft connected to the upper diaphragm is fixed between the valve body and the fixing nut by tightening the fixing nut into which the O-ring is inserted, and accordingly, the expansion or contraction of the temperature-sensitive portion has an effect of being transmitted to the ball valve direction through the valve rod.

In addition, according to the present invention, even if the expansion valve is mounted horizontally or downwardly in a vehicle, the sensitivity of the diaphragm can be prevented from deteriorating, so that the piping layout of the air conditioning system can be freed up by the designer.

Furthermore, the present invention can improve piping freezing prevention and performance deterioration due to malfunction of the expansion valve without complicated structural changes, thereby improving the merchandise of the vehicle without a significant increase in production cost.

1 is a configuration diagram showing the configuration of a general vehicle air conditioning system.
Figure 2 is a cross-sectional view showing an expansion valve of a conventional vehicle air conditioning system.
Figure 3 is a cross-sectional view showing an expansion valve of a vehicle air conditioning system according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

In addition, terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or lexical meanings, and the inventor appropriately defines the concept of terms in order to describe his or her invention in the best way. Based on the principle that it can be done, it should be interpreted as a meaning and a concept consistent with the technical idea of the present invention.

3 is a cross-sectional view showing an expansion valve of a vehicle air conditioning system according to an embodiment of the present invention.

As shown in Figure 3, the expansion valve of the vehicle air conditioning system according to an embodiment of the present invention is disposed on the upper portion of the ball valve 32 and the temperature-sensitive portion sealed by the upper diaphragm 22 and the lower diaphragm 24 (20), the upper end is connected to the lower diaphragm 24, the lower end is connected to the ball valve 32, and the valve rod 30 movable up and down according to the vertical deformation of the lower diaphragm 24, the temperature sensing unit 20 ) Is disposed on the upper portion of the first refrigerant flow path 40 for discharging the refrigerant delivered from the evaporator to the compressor and the second refrigerant flow path disposed at the lower portion of the temperature sensing unit 20 to discharge the refrigerant delivered from the evaporator to the compressor ( It characterized in that it comprises 50).

As shown in the illustrated embodiment, the expansion valve according to the present invention includes a valve body 10 formed in a cylindrical cylinder shape, and an inflow passage 12 through which refrigerant transferred from a condenser flows in the lower side of the valve body 10 ), An outflow passage 14 for sending the expanded refrigerant to the evaporator, a throttle passage 16 formed between the inflow passage 12 and the outflow passage 14 to throttle the refrigerant is formed.

The throttle passage 16 can be opened and closed by a ball valve 32, a spring 34 is installed under the ball valve 32 to move the ball valve 32 in the direction of the throttle passage 16 (that is, throttling Elastically pressurizes in the direction of closing the flow path 16).

The ball valve 32 has an upper diaphragm 22 and a thermally sealed portion 20 sealed by a lower diaphragm 24 disposed therein, and a gaseous substance whose pressure is sensitively changed to temperature inside the thermally sensitive portion 20. It is sealed.

The gaseous material expands or contracts depending on the temperature (superheat) of the refrigerant flowing from the outlet of the evaporator toward the compressor, and the lower diaphragm 24 is deformed up and down according to the expansion or contraction of the gaseous material.

A valve rod 30 is connected to the lower end of the lower diaphragm 24, and the valve rod 30 includes an inflow passage 12, an outflow passage 14, a throttle passage 16, and a second refrigerant passage 50 to be described later. ) And extends downward.

The lower end of the valve rod 30 is in contact with the ball valve 32, and when the gas inside the temperature sensing unit 20 expands, the valve rod 30 moves downward to move the ball valve 32 downward, When the gas inside the temperature sensing unit 20 contracts, the valve rod 30 moves upward, and accordingly, the ball valve 32 moves upward by the elastic force of the spring 34.

As the ball valve 32 opens or closes the throttle passage 16 according to the vertical movement of the valve rod 30, the flow rate of the refrigerant passing through the throttle passage 16 is automatically adjusted and the superheat degree is constant. Is maintained.

At this time, when the flow rate of the refrigerant passing through the throttle passage 16 is excessive, the refrigerant cannot be completely evaporated in the evaporator, resulting in a phenomenon in which low pressure piping freezes, and the flow rate of the refrigerant passing through the throttle passage 16 is too small. If the evaporator is completed in the evaporator too quickly, the cooling efficiency is lowered, so the superheat degree is preferably maintained at about 5 ° C.

A first refrigerant passage 40 for discharging the refrigerant delivered from the evaporator to the compressor is formed on the upper portion of the temperature sensing unit 20, and a refrigerant for discharging the refrigerant delivered from the evaporator to the compressor is formed at the lower portion of the temperature sensing unit 20. 2 The refrigerant flow path 50 is formed.

As illustrated, the refrigerant discharged from the evaporator branches upward and downward, passes through the first refrigerant passage 40 and the second refrigerant passage 50, and then merges again into one strand at the outlet of the expansion valve.

In this way, the upper and lower diaphragms 22 are formed by separately forming the first refrigerant passage 40 and the second refrigerant passage 50 above and below the temperature sensing unit 20 and allowing the refrigerant discharged from the evaporator to branch upward and downward. Alternatively, even if one of the lower diaphragms 24 is deteriorated in temperature sensitivity by foreign matter, the other diaphragm may detect the superheat.

A shaft 60 is connected to an upper end of the upper diaphragm 22, and the shaft 60 indirectly transfers the temperature of the refrigerant passing through the first refrigerant passage 40 to the temperature-sensitive portion 20 to reduce the temperature. (20) It serves to expand or contract the gas inside.

In addition, the upper end of the shaft 60 is fixed between the valve body 10 and the fixing nut 62 by tightening the fixing nut 62 disposed on the upper portion of the valve body 10, and the fixing nut ( O-ring 64 is inserted into the outer circumferential surface of 62) to maintain the airtightness of the expansion valve.

That is, unlike the valve rod 30, the shaft 60 is not configured to move up and down, and thus the upper diaphragm 22 is not deformed up and down, even if the gas inside the temperature sensing section 20 expands or contracts. Only the diaphragm 24 is deformed up and down.

Looking at the operation of the expansion valve of the vehicle air conditioning system according to an embodiment of the present invention.

First, the pressure of the refrigerant passing through the first refrigerant passage 40 or the second refrigerant passage 50 and the elastic force of the spring 34 disposed under the ball valve 32 are applied to the pressure inside the temperature sensing part 20. If it is relatively larger than the added value, the lower diaphragm 24 is deformed downward.

At this time, it should be noted that unlike the conventional expansion valve, the expansion valve according to the present invention can deform the lower diaphragm 24 even by the pressure (or superheat) of the refrigerant passing through the first refrigerant passage 40.

As the lower diaphragm 24 is deformed downward, the valve rod 30 is moved downward to open the throttle passage 16, thereby increasing the flow rate of the refrigerant supplied to the evaporator to reduce the superheat.

Conversely, if the pressure inside the temperature sensing unit 20 is relatively smaller than the value of the pressure of the refrigerant passing through the first refrigerant passage 40 or the second refrigerant passage 50 and the elastic force of the spring 34, the lower diaphragm (24) is deformed upward.

As the lower diaphragm 24 is deformed upward, the valve rod 30 moves upward and the ball valve 32 closes the throttle passage 16 by the elastic force of the spring 34, thereby supplying it to the evaporator The flow rate of the refrigerant to be reduced is reduced to increase the superheat.

Therefore, the expansion valve for an air conditioning system for a vehicle according to the present invention can accurately reflect the superheat degree of the refrigerant passing through the upper or lower portion of the temperature sensing unit 20, thereby preventing freezing of low-pressure pipes and improving performance of the air conditioning system. There will be.

In the technical field to which the present invention pertains, the present invention described above is not limited by the above-described embodiments and the accompanying drawings, and various substitutions, modifications and changes are possible without departing from the technical spirit of the present invention. It will be obvious to those of ordinary skill.

10: valve body
12: Inflow channel
14: flow path
16: throttle passage
20: thermal section
22: upper diaphragm
24: lower diaphragm
30: valve rod
32: ball valve
34: spring
40: first refrigerant passage
50: second refrigerant passage
60: shaft
62: fixing nut
64: O-ring

Claims (5)

In the expansion valve of the air conditioning system for a vehicle, including a ball valve for opening and closing the throttle passage formed between the inlet flow path through which the refrigerant transferred from the condenser flows in and the outlet flow path through which the expanded refrigerant flows to the evaporator,
A temperature sensing unit disposed on the ball valve and sealed by an upper diaphragm and a lower diaphragm;
A valve rod having an upper end connected to the lower diaphragm, a lower end contacting a ball valve, and movable up and down according to vertical deformation of the lower diaphragm;
A first refrigerant passage disposed on the upper portion of the temperature sensing unit and discharging the refrigerant transferred from the evaporator to a compressor; And
A second refrigerant flow path disposed below the temperature sensing unit and discharging the refrigerant transferred from the evaporator to a compressor; It includes,
The refrigerant discharged from the evaporator is branched up and down, and the expansion valve of an air conditioning system for a vehicle is characterized in that it is transferred to the first refrigerant passage and the second refrigerant passage.
According to claim 1,
A shaft with an upper end connected to the valve body and a lower end connected to the upper diaphragm; Further comprising,
The shaft is an expansion valve of an air conditioning system for a vehicle, characterized in that the temperature of the refrigerant passing through the first refrigerant passage is transferred to the temperature sensing unit to expand or contract the temperature sensing unit.
According to claim 2,
The upper end of the shaft is fixed between the valve body and the fixing nut by tightening the fixing nut disposed on the top,
Expansion valve of the vehicle air conditioning system, characterized in that the O-ring is inserted into the outer circumferential surface of the fixing nut.
According to claim 1,
When the pressure inside the temperature sensing unit is relatively greater than the value of the pressure of the refrigerant passing through the first refrigerant passage or the second refrigerant passage plus the elastic force of the spring disposed under the ball valve, the valve rod moves downward to open the throttle passage Expansion valve of the vehicle air conditioning system, characterized in that the.
According to claim 1,
If the pressure inside the temperature sensing unit is relatively smaller than the value of the pressure of the refrigerant passing through the first refrigerant passage or the second refrigerant passage plus the elastic force of the spring disposed at the bottom of the ball valve, the valve rod is moved upward to move the throttle passage. Expansion valve of the vehicle air conditioning system, characterized in that closed.

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