JPH0953869A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a highly responsible expansion valve by heating energizingly an electric heater via a terminal, and opening an orifice at the time when the gas pressure of a temperature-sensitive gas discharged from an absorption member is transmitted to a diaphragm gas chamber. SOLUTION: A carbon disk 260 is provided as an absorption member which is layered in an electric heater 250 in a housing 210 while there is provided a disk-shaped member 232, which is a support member layered on the side of the electric heater 250 and one side of the carbon disk 260. There are provided hermetic terminals 240 and 245, which penetrate through the housing 210 and are electrically connected to the electric heater 250. At the time when the gas pressure of a temperature-sensitive gas discharged from the carbon disk 260 by heating with the electric heater 250 by way of the hermetic terminals 240 and 245, is transmitted to a gas chamber 23 of a diaphragm 280, an orifice is arranged to be opened. It is, therefore, possible to provide a highly responsible expansion valve 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve used in a refrigeration system, and is particularly suitable for use in a refrigeration system provided with a plurality of refrigerant evaporators in one refrigeration cycle.

[0002]

2. Description of the Related Art Conventionally, there is a refrigerating apparatus having a plurality of refrigerant evaporators in one refrigerating cycle. In such a refrigerating apparatus, it is not necessary to constantly supply the refrigerant to all the refrigerant evaporators, and it is sufficient to supply the refrigerant only to the refrigerant evaporators used as needed. Therefore, in general, solenoid valves are installed in the refrigerant pipes that guide the refrigerant to the respective refrigerant evaporators, but by using this solenoid valve, the number of parts increases and the connecting points The cost will increase due to the increase in

Therefore, a technique has been proposed in which the supply of the refrigerant is stopped by forcibly closing the expansion valve installed upstream of the refrigerant evaporator without using the solenoid valve. For example, in Japanese Patent Laid-Open No. 7-4786, an adsorbent that adsorbs a refrigerant gas that acts as a temperature-sensitive gas is placed inside a gas control cylinder that communicates with a temperature-sensitive cylinder of an expansion valve via a capillary tube. Disclosed is a structure in which when the heating cylinder is heated by the electric heater, the refrigerant gas that has been adsorbed until then is released, and when the electric current to the electric heater is stopped, the refrigerant gas is adsorbed to a saturated state at room temperature. With this structure, when the energization of the electric heater is stopped and the adsorbent adsorbs the refrigerant gas, the pressure in the greenhouse is lowered and the expansion valve is fully closed.

[0004]

However, the expansion valve described in the above publication may easily dissipate heat from the electric heater, and it may take a long time to respond. The present invention provides a highly responsive expansion valve.

[0005]

An expansion valve according to the present invention has a control section for adjusting the opening of an orifice section of a valve section. The control section includes an electric heater installed in a housing and an electric heater. A gas adsorbing member for adsorbing the stacked gas, an electric heater and a supporting member for supporting the adsorbing member, and a terminal electrically connected to the electric heater and the adsorbing member are provided.

[0006]

[Operation] The electric heater and the gas adsorbing member are electrically heated,
The gas adsorbing member is heated by the electric heater, and the gas adsorbing member itself also self-heats to release the temperature-sensitive gas from the gas adsorbing member to open the orifice portion.

[0007]

1 is a sectional view showing the overall construction of an expansion valve according to the present invention, and FIG. 2 is a sectional view showing details of an operation control portion of the valve. The expansion valve, which is generally indicated by reference numeral 1, has a valve portion 10 and
It has a valve body operation control unit 20 and a temperature sensing unit 30 arranged in the valve unit 10. The valve portion 10 has an inlet port 120 for high-pressure refrigerant formed in the valve body 100 and an outlet port 110 for adiabatically expanding this refrigerant, and the inlet port 1
A valve element 132 is provided at the tip of the actuation rod 130 penetrating 20. The valve body 132 has, for example, a spherical shape, and opens and closes a passage for the refrigerant between the valve body 132 of the inlet port 120 and an orifice member 122 provided in a portion facing the valve body 132,
The inlet port 120 and the outlet port 110 communicate with each other via an orifice member 122. It should be noted that FIG. 1 shows the valve open state, and 300 is a pressure equalizing hole, which transmits the pressure of the outlet port 110 to the gas chamber 237 below the diaphragm 280.

The valve body 132 is supported by the receiving member 140, and the orifice member 122 is supported by a spring 142.
Is urged towards. Inlet port 120 of valve body 100
The nut 144 having a hexagonal hole that is screwed in supports the spring 142 and adopts a structure in which the refrigerant flows out through the hexagonal hole. The valve operation control unit 20
It has a structure in which the support plate 220 and the diaphragm 280 are sandwiched by the cylindrical housing 210 and the flange member 212, and the outer peripheral portion is fixed by arc welding. A disk-shaped member 232, which is a first supporting member made of insulating phenol resin, is inserted into the housing 210, and this member is further supported by a ring member 230 made of phenol resin. The disk-shaped member 232 has a pair of hermetic terminals 240 penetrating the housing 210,
245 is inserted, and these hermetic terminals 240, 2
45 is fixed to the housing 210 by soldering.

An electric heater 250 is disposed below the disk-shaped member 232 into which the hermetic terminals 240 and 245 are inserted. The electric heater 250 is a disc-shaped element (for example, a heating element of a product name PTC thermistor manufactured by TDK Corporation) having a characteristic of generating heat at a constant temperature when receiving an applied voltage. An electrode 243 is provided on one surface of the electric heater 250 (a surface in contact with the disk-shaped member 232). The disk-shaped member 232 is formed with a plurality of recesses 297 adjacent to the disk member 232 so as to make line contact with the electrode 243.

On the other surface of the electric heater 250, for example, a carbon disk 260 is laminated as a gas adsorption member. The carbon disk 260 has insulating films 292 and 291 and conductive films 294 and 29 as described in FIG.
5 is formed, and the insulating film 292 and the conductive film 295 are interposed between the electric heater 250. Therefore, the electric heater and the carbon disc are electrically connected to each other with a predetermined contact area, and are insulated except for this contact area. The carbon disk 260 is made by firing particles of activated carbon into a disk shape and has a function of adsorbing a refrigerant gas. Carbon disk 260
Are supported by a support disk 270 which is a second support member made of phenol resin. Since the insulating film 291 and the conductive film 294 are formed on the carbon disk 260, these films are interposed between the carbon disk 260 and the support disk 270. Further, an electrode 247 is formed on the film of the carbon disk 260, and a plurality of recesses 298 are formed adjacent to the support disk 270 so that the support disk 270 makes line contact with the electrode 247, that is, the carbon disk 260. Has been formed. The support disk 270 is supported by the metal disk 274 via the spring washer 272.
The metal disk 274 is fixed by being pressed into the inner peripheral portion of the housing 210. The metal disk 27
4 and the support plate 220, a spacer 276 is provided.

With this structure, the spring washer 27
2 presses the carbon disk 260 and the electric heater 250 against the disk-shaped member 232 via the support disk 270. A tip portion 242 of the hermetic terminal 240 is connected to an electrode 243 formed on one surface of the electric heater 250. Further, the hermetic terminal 245 is connected to the electrode 247 by the lead wire 246. As a result, the carbon disc 260
Is a conductor, the hermetic terminals 240 and 24 are
When a voltage is applied to No. 5, the electric heater 250 and the carbon disk 260 are electrically connected and connected in series, and the carbon disk 260 is heated by the electric heater 250 and the carbon disk 260 itself also self-heats. To do. Moreover, since the electric heater 250 is in line contact with the disc-shaped member 232 with the electrode 243 interposed therebetween, heat dissipation from the electric heater 250 can be reduced, and the carbon disc 260 also has the support disc 270 sandwiched with the electrode 247. Since it is in line contact with, it is possible to reduce heat radiation from the carbon disk 260.
Further, regarding the heat generation of the carbon disc 260,
Due to the presence of the insulating films 291 and 292 provided on both sides of 60, it is possible to sufficiently generate heat by increasing the distance of heat generation, that is, by increasing the resistance value.

In the above embodiments, the case where the support members 232 and 270 are provided on the electric heater side and the carbon disk side respectively has been described, but the present invention is not limited to this, and the support members are provided on the electric heater side. Of course, it is possible to reduce the heat dissipation even if it is provided on either side of the carbon disk. In that case, for example, when the support member 270 is omitted, the carbon disk 260 may be supported by the spring washer 272 (for example, resin is used). Further, when the support member 232 is omitted, the hermetic terminal is connected to the electrode without being inserted into the support member 232. Further, in the present invention, the electric heater 250
In addition, the carbon disk 260 itself is not limited to the case where it self-heats, but it can be applied to the case where the carbon disk 260 is heated by heat generated by energizing only the electric heater 250. Heater 25
An electrode 247 may be provided on the side laminated with the 0 carbon disk, the lead wire 246 of the hermetic terminal 245 may be connected to this electrode, and the hermetic terminal 240 may be connected to the electrode 243 of the electric heater 250.

The line contact is between the electric heater 250 and the disk-shaped member 232 and between the carbon disk 260 and the support disk 270.
However, the present invention is not limited to this, and only one of them, for example, the line contact is formed between the electric heater 250 and the disk-shaped member 232. That is, it goes without saying that a plurality of recesses may be formed in the disc-shaped member 232.

The present invention is not limited to the line contact, and the support member may be provided with, for example, an appropriate number of protrusions to form the point contact. In addition, it goes without saying that the recesses or the projections are easily formed by the mold. Further, in the case of configuring the line contact, the shape of the electrode 243 formed on the electric heater without forming a recess in the support member may be a linear electrode or a spirally wound electrode. That is, by the linear electrode that constitutes the line contact,
The contact area between the support member and the electric heater may be reduced.

FIG. 3 shows a resin film 290 overlaid on the carbon disk 260. The resin film 290 is shown in FIG.
A pair of disc-shaped insulating films 291, 29
2 is connected by a bridge 293, and the conductive film 29 is provided at a diagonal position of the insulating films 291 and 292.
4, 295 (formed by depositing a metal film on the resin film 290). The carbon disk 260 is covered with this resin film 290 (shown in FIG. 3 (B)).
Thus, as shown in FIG. 3 (C), the carbon disc 260
The longest conductive path can be formed therein. By increasing the length of the conductive path, the resistance value increases and the amount of heat generation also increases. Further, in the present invention, it is needless to say that the same effect can be obtained by replacing the conductive film of the resin film 290 with a metal film and substituting it for example as shown in FIG.

In FIG. 4, the same reference numerals as those in FIG. 3 indicate the same or equivalent portions, FIG. 4 (A) shows the insulating film portion, and FIG. 4 (B) shows the state in which the suction member is covered with the insulating film. 4D shows a case of replacing with a metal film (for example, stainless steel is used as a metal). Note that FIG. 4C shows a state in which the suction member is sandwiched. Further, in the present invention, needless to say, the resin film as shown in FIG. 3 and FIG. 4 may be omitted if the heat generation of the carbon disk 260 itself is sufficient.

As described above, according to the present invention, the electric heater 250 is used.
The carbon disc is heated by the heat generated by the
The carbon disk 260 is efficiently heated by the self-heating of 0 itself and releases the adsorbed refrigerant gas. A spacer 276 is inserted below the metal disk 274 press-fitted into the housing 210, and the spacer 276 is supported by the support plate 220.

Refrigerant gas is enclosed in the capillary tube 310, and the capillary tube 310 is brazed to the housing 210 and opens into a recess 234 formed in the disk-shaped member 232. The heat sensitive portion 30 is formed by winding the tip end portion of the capillary tube 310. The heat sensitive section 30 is attached to the outlet piping section of the evaporator of the refrigeration system, detects the temperature of the piping, and controls the internal gas pressure. The gas of the temperature-sensitive part 30 flows from the recess 234 to the gas chamber 236.
The gas released from the carbon disk 260 is sent to the gas chamber 236 between the flange 212 and the support plate 220 and above the diaphragm 280.
The diaphragm 280 is displaced by the gas pressure of the gas chamber 236, and this displacement is transmitted to the operating member 282. The actuating member 282 is connected to the actuating rod 130, and the displacement amount of the actuating member 282 is determined by the actuating rod 130.
And the opening area of the orifice is controlled.

In the expansion valve of the present invention, the electric heater 2
50 and the carbon disk 260 are electrically heated, and the carbon disk 260 is heated.
The diaphragm 280 is in a position to open and close the valve element 132 via the actuating rod 130 in a state where the gas discharged from the gas chamber 236 is filled. In this state, when the temperature of the temperature sensing unit 30 rises, the valve body 132 is opened by receiving the gas pressure. Therefore, the electric heater 250 and the carbon disk 260
The expansion valve remains closed when no current is applied to the valve.

In the above description, the case where a capillary tube is provided as an expansion valve has been described, but the present invention can be applied to other expansion valves, for example, a conventionally known temperature expansion valve that does not use a capillary tube. . That is, FIG. 5 is a vertical cross-sectional view showing the structure of an embodiment of the present invention showing the expansion valve, and FIG. 6 is a side view showing the overall external structure of the side surface of FIG. FIG. 7 is a diagram showing the upper surface of FIG. 6. In FIG. 6, reference numeral 550 is a through hole for a bolt for attaching the expansion valve. This expansion valve has a valve section 530 and an operation control section 520 arranged in the valve section 530. The valve portion 530 has a substantially rectangular outer shape, and a lower portion thereof is stolen to form a thin wall.

In the valve portion 530, there is provided a first passage 532 which is interposed between the refrigerant outlet of the condenser 55 which constitutes the refrigeration cycle and the receiver 56 to the refrigerant inlet of the evaporator 58, and the refrigerant outlet of the evaporator 58. To a refrigerant inlet of the compressor 54, a second passage 534 interposed between the second passage 534 and the second inlet 534 is formed vertically apart from each other.

A valve hole 532a for adiabatically expanding the liquid refrigerant supplied from the refrigerant outlet of the receiver 56 is formed in the first passage 532. A valve seat is formed at the inlet of the valve hole 532a, and the valve body 532b is biased on the valve seat by a biasing means 532c such as a compression coil spring. The first passage 532 into which the liquid refrigerant from the receiver 56 is introduced serves as a passage for the liquid refrigerant, and has an inlet port 321 and a valve chamber 535 continuous with the inlet port 321. The valve chamber 535 is a bottomed chamber formed coaxially with the valve hole 532 a, and is closed by a plug 537.

An operation control unit 520 for driving the valve body 532b is mounted on the upper end of the valve unit 530. The configuration of the operation control unit 520 is the same as that of the operation control unit 20 shown in FIGS. 1 and 2.
And the same reference numerals indicate the same parts. In the operation control unit 520, the flange member 212 is attached to the upper end of the valve unit 530 via a packing 570 by screwing. Housing 2 that constitutes operation control unit 520
Refrigerant gas is enclosed in 10, and the tube 540 for enclosing the refrigerant gas is completely closed after the refrigerant gas is enclosed. The enclosed refrigerant gas is sent from the recess 234 to the gas chamber 236 above the diaphragm 280. The gas chamber 237 below the diaphragm 280 is
The pressure in the passage 534 is transmitted.

An evaporator 58 is provided in the second passage 534.
The refrigerant vapor flows from the refrigerant outlet of the passage, the passage 534 becomes the passage of the vapor phase refrigerant, and the pressure of the refrigerant vapor is equalized by the pressure equalizing hole 536e.
Is loaded in the lower pressure working chamber 536c through.
The lower pressure working chamber 536c communicates with the second passage 534 through a pressure equalizing hole 536e formed concentrically with respect to the center line of the valve hole 532a.

A diaphragm 280 is provided in the pressure equalizing hole 536e.
A valve element drive rod 536f extending from the lower surface of the valve to the valve hole 532a of the first passage 532 is concentrically arranged. The valve body driving rod 536f is slidably supported in the vertical direction by the inner surface of the pressure working chamber 536c and the partition wall of the second passage 534 and the first passage 532, and the lower end thereof is supported by the valve body 532b.
Abutting against. A packing for preventing refrigerant leakage between the first passage 532 and the second passage 534 is provided in a region of the outer peripheral surface of the valve body drive rod 536f corresponding to the sliding guide hole of the valve body drive rod in the partition wall. 536g is provided.

The housing 210 of the operation control section 520 is filled with a refrigerant gas and is exposed to the second passage 534 and the pressure equalizing hole 536e communicating with the second passage 534. The heat of the refrigerant vapor from the refrigerant outlet of the evaporator 58 flowing through the second passage 534 is transmitted via the 536f and the diaphragm 280, and the operation control unit 5
20 will operate as a temperature sensing part. Therefore, the pressure corresponding to the heat transferred to the refrigerant gas of the temperature sensing part is applied to the upper surface of the diaphragm 280, and the diaphragm 280 is the difference between the pressure of the gas applied to the upper surface and the pressure applied to the lower surface of the diaphragm. It is displaced up and down by. This displacement is transmitted to the valve body 532b via the valve body drive rod 536f to move the valve body 532b toward or away from the valve seat of the valve hole 532a, and as a result, the refrigerant flow rate is controlled.

When the hermetic terminals 240 and 245 of the operation control section 520 are energized, the heat generated by the electric heater 250, which is a heating element, causes the carbon disk 260 as an adsorbing member.
The more adsorbed refrigerant gas is released, the pressure is applied to the upper surface of the diaphragm 280, and the valve element drive rod 536f
Causes the valve element 532b to separate from the valve seat, and the valve is opened (shown in FIG. 5). The hermetic terminals 240 and 24
When the current is not supplied to 5, the refrigerant gas is adsorbed by the adsorbing member, the pressure in the temperature sensing portion is low, and the valve body 532b is closed.

[0028]

Industrial Applicability The present invention has a valve body which is opened and closed by a diaphragm in the housing, and detects the temperature of the gas chamber of the diaphragm and the outlet pipe part of the evaporator to control the gas pressure sent to the gas chamber. In an expansion valve having a section, an electric heater and an adsorbing member are provided in a housing, and the gas released from the adsorbing member due to heating of the adsorbing member due to heat generation of the electric heater or self-heating of the adsorbing member enters a gas chamber When supplied, it has a function of controlling valve opening. Therefore, when the electric heater and the adsorption member are not energized, the valve closed state is maintained, so that the expansion valve with a valve closing function having a small size and a small number of parts can be configured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the entire structure of an expansion valve of the present invention.

FIG. 2 is a sectional view showing an operation control unit of the expansion valve of the present invention.

FIG. 3 is an explanatory view of a resin film sandwiching a carbon disc.

FIG. 4 is an explanatory view of a metal film sandwiching a carbon disc.

FIG. 5 is a cross-sectional view showing another embodiment of the expansion valve of the present invention.

6 is a side view of the expansion valve shown in FIG.

FIG. 7 is a top view of the expansion valve shown in FIG.

[Explanation of symbols]

 1 Expansion Valve 10 Valve Section 20 Operation Control Section 30 Temperature Sensing Section 100 Valve Main Body 130 Actuating Rod 132 Valve Body 210 Housing 250 Electric Heater 260 Carbon Disk 280 Diaphragm 310 Capillary Tube

Claims (15)

[Claims] 1. A valve body for varying the opening of an orifice portion communicating with a high-pressure refrigerant passage, a valve portion having a biasing means for biasing the orifice portion in a direction of reducing the opening degree, and the valve portion. And an electric heater in the housing, which has a diaphragm installed in the housing, and controls the valve body to increase the orifice opening as the pressure of the gas chamber of the diaphragm rises. And a suction member laminated on the electric heater, a support member laminated on at least one side of the electric heater side and the suction member side, and provided through the housing, A terminal electrically connected to the electric heater is provided, and the electric heater is energized and heated through the terminal, and the gas pressure of the temperature-sensitive gas released from the adsorbing member changes the gas pressure of the diaphragm. Expansion valve characterized in that when it is transmitted to the chamber, the orifice portion opens. 2. A valve body for varying the opening of an orifice communicating with the high-pressure refrigerant passage, a valve having a biasing means for biasing the opening of the orifice to decrease, and the valve provided on the valve. And an electric heater in the housing, which has a diaphragm installed in the housing, and controls the valve body to increase the orifice opening as the pressure of the gas chamber of the diaphragm rises. And an adsorption member laminated on the electric heater, and a supporting member laminated on each of the electric heater side and the adsorption member side, and provided through the housing and the supporting member. The electric heater and the adsorption member are provided with terminals electrically connected to each other, and the electric heater and the adsorption member are electrically heated through the terminals and are discharged from the adsorption member. An expansion valve characterized in that the orifice portion opens when the gas pressure of the gas is transmitted to the gas chamber of the diaphragm. 3. A valve body for varying the opening of an orifice communicating with the high-pressure refrigerant passage, a valve having a biasing means for biasing the orifice to reduce the opening of the orifice, and the valve provided on the valve. An operation control section of the valve body for controlling the orifice opening to increase in accordance with an increase in the pressure of the gas chamber of the diaphragm, and a diaphragm installed in the housing. No. 1 support member, an electric heater laminated on this first support member, an adsorption member laminated on this electric heater, a second support member laminated on this adsorption member, and this second support An elastic body that supports the member,
A terminal is provided penetrating the housing and the first support member and electrically connected to the electric heater and the suction member, respectively. The electric heater and the suction member are electrically heated through the terminals. The expansion valve is characterized in that the orifice portion opens when the gas pressure of the temperature-sensitive gas released from the adsorption member is transmitted to the gas chamber of the diaphragm. 4. The electric heater is provided with an electrode, and the electric heater and the first supporting member are laminated in line contact or point contact via the electrode. Expansion valve described. 5. The electrode is provided on the adsorption member, and the adsorption member and the second support member are laminated in line contact or point contact via the electrode. Expansion valve described. 6. The first supporting member is provided with a concave portion on a side of the first supporting member to be laminated with the electric heater, and the linear contact is formed by the concave portion.
An expansion valve as described. 7. The first support member is provided with a protrusion on the side of the member on which the electric heater is laminated, and the point contact is formed by the protrusion. Expansion valve described. 8. The electrode is configured as a linear electrode, and the line contact is formed by the electrode.
An expansion valve as described. 9. The second support member according to claim 5, wherein a recess is provided on a side of the second support member that is laminated with the suction member, and the line contact is formed by the recess. Expansion valve. 10. The second support member is provided with a protrusion on the side of the member that is laminated with the suction member, and the point contact is formed by the protrusion. Expansion valve described. 11. The expansion valve according to claim 5, wherein the electrode is a linear electrode, and a linear contact is formed by the electrode. 12. The expansion valve according to claim 6, wherein a plurality of the recesses are provided adjacent to each other. 13. An expansion valve having a temperature-sensing portion, in which a refrigerant gas formed facing a diaphragm that drives a valve body for controlling the refrigerant flow rate of high-pressure refrigerant, is sealed, wherein the temperature-sensing portion includes the refrigerant gas. And an adsorbing member for adsorbing the adsorbent, and a heating element that is in thermal contact with the adsorbing member, and the diaphragm drives the valve element by releasing adsorbed gas from the adsorbing member due to heat generation of the heating element. Expansion valve characterized by. 14. The expansion valve according to claim 13, wherein the adsorption member and the heating element are electrically connected to each other, and both the adsorption member and the heating element generate heat. 15. The expansion valve according to claim 13, wherein only the heating element is energized to heat the adsorption member by the heating element.