JPH08320171A - Opening/closing valve and freezing system using it - Google Patents

Abstract

PURPOSE: To provide an opening/closing valve for use in a freezing cycle which is slow in its opening/closing operation. CONSTITUTION: A valve body 10 includes an inlet port 12 and an outlet port 14, and both ports are coupled with an orifice 16. A valve disc 42 in contact with a lower end of a stem 40 is energyzed toward the orifice 16 with the aid of a support member 36 and a spring 38. A flange 44 of an upper part of the stem 40 is slidably inserted into a casing 52 and is held by two springs 60, 62. The spring 60 is made of a shape storing alloy and is accomodated in a cap 54 comprising a good heat conductive material. An electric heater 70 is disposed on the upper part of the cap 54 and is connected with an external power supply through lead plates 72, 74. Once the electric heater 70 is heated and the spring 60 is heated, the spring 60 is elongated to press down the valve disc 42 from the orifice to open the valve. Once the power supply to the electric heater 70 is interrupted, the valve is closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-off valve for opening and closing a fluid passage and a refrigeration system using the same.

[0002]

2. Description of the Related Art For example, FIG. 4 shows a refrigeration system for a car air conditioner, in which a refrigerant pressurized by a compressor 1 is liquefied by a condenser 2 and stored in a liquid receiver 3. Liquid refrigerant is 2
System, one of which is an expansion valve 5a and an evaporator 6a
To the evaporator 6 through the valve 4 and the expansion valve 5b.
sent to b. In this car air conditioner, one evaporator 6a and its accessory are installed in the front seat to send cool air to the front seat. The other evaporator 6b and its accessories are installed in the rear seat and send cool air to the rear seat. The low-pressure refrigerant vaporized by the evaporator is returned to the compressor 1. In such a car air conditioner, when no passenger is in the rear seat, the line on the rear seat side is closed to make effective use of energy. As the open / close valve 4, a solenoid valve has been used conventionally.

[0003]

In such a refrigeration system, when the rear seat evaporator 6b is used for cooling operation, for example, when the solenoid valve 4 is opened, the solenoid valve has a quick response,
The valve opens and closes rapidly. Therefore, when the solenoid valve suddenly opens, the high-pressure liquid refrigerant on the solenoid valve inlet side is rapidly released to the low-pressure gas refrigerant of the refrigerant evaporator through the expansion valve, causing pulsation of the fluid (refrigerant) and abnormal pressure change. There was a problem that vibration noise was generated in the piping section, and the quietness of the passenger compartment was impaired.
When the solenoid valve is closed suddenly when the cooling operation is stopped, the flow of the refrigerant from the condenser to the refrigerant evaporator via the receiver and the expansion valve is stopped, so that the refrigerant pulsation (water hammer action). There is a problem that vibration noise is generated in the piping part, and the quietness of the vehicle compartment is impaired. The present invention provides an open / close valve that solves the above-mentioned problems.

[0004]

The on-off valve of the present invention comprises:
An orifice portion having a liquid inlet port and an outlet port, formed between the inlet ports, a valve body for varying the opening degree of the orifice portion, and a biasing valve element for reducing the opening degree of the orifice portion. And a spring made of a shape memory alloy for urging the valve body in a direction to increase the opening of the orifice portion,
An electric heater for heating a spring made of a shape memory alloy. A bias spring for urging the valve body is provided at a position where the valve body closes the orifice when the electric heater does not generate heat.

[0005]

When the electric heater is energized to generate heat, the spring made of shape memory alloy expands, opens the valve, and stops energization.
The valve closes.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing the overall structure of an opening / closing valve of the present invention. The on-off valve of the present invention has a valve body 10 made of brass or the like, the valve body 10 is provided with a liquid inlet port 12 and a liquid outlet port 14, and an orifice 16 that connects the two. An inner screw 20 is provided in an opening formed coaxially with the orifice 16 and a cap 30 is screwed therein. An O-ring 32 is interposed between the cap 30 and the valve body 10 for sealing.

A valve element 42 is attached to the end of the stem 40, which is disposed through the orifice 16, facing the orifice. The valve body 42 has, for example, a spherical shape, and a support spring 38 is provided on the opposite side of the stem 40 via a support member 36.
Is arranged. Further, the valve element 42 and the support member 36 are welded by spot welding, and the valve element 42 and the lower end of the stem 40 are only in contact with each other. The support spring 38 is supported by the cap 30, and the support spring 38 and the support member 36, which also function as a bias spring, connect the valve body 42 to the orifice 16.
Energize toward the side. A threaded portion 22 is formed on a boss portion of the valve body 10 on the side where the stem 40 penetrates, and a receiving member 50 is screwed into the threaded portion 22 so that the receiving member 50 has a cap shape having a large-diameter flange. A cylindrical casing 52 having the shape of 1 is welded to the flange portion by the welding means 51. The receiving member 50 and the casing 52 are
For example, it is made of stainless steel. The inside of the casing 52 and the port 14 are communicated with each other through the pressure equalizing hole 18.

A cylindrical cap 54 having a bottom is attached to the upper part of the casing 52 by a fixing means 53 such as brazing. The cap 54 is made of a material having high thermal conductivity such as a copper alloy. The other end of the stem 40 having the valve body 42 attached to one end is formed into a large-diameter flange 44, and the two coil springs 6 are sandwiched by the flange 44.
0, 62 are provided.

The flange portion 44 of the stem 40 and the cap 5
The first spring 60 disposed between the first and second springs 4 and 4 is a coil spring made of a shape memory alloy. When the first coil spring 60 is heated to a preset temperature, the first coil spring 60 deforms in the direction in which the spring extends. Stem 4 using this power
The valve element 42 is moved in the valve opening direction via 0. When the heating of the shape memory coil spring 60 is cut off and the temperature drops,
Extension force decreases. The flange portion 44 of the stem 40 is pressed toward the shape memory coil spring 60 by the spring force of the second coil spring 62 acting as a bias spring and the support spring 38, and the valve body 42 closes the orifice 16.

An insulating sheet 76 is provided on the upper surface of the cap 54.
One electrode terminal 74 is placed via the. Electrode terminal 7
4 has a disc-shaped main body and a lead plate extending from the main body, and an electric heater 70 is mounted on the main body. The other electrode terminal 72 is placed on the upper surface of the electric heater 70.
The electrode terminal 72 has a body of a disc spring and a lead plate extending from the body. The electric heater 70 is a disk-shaped element (for example, a heating element of PTC thermistor manufactured by TDK Corporation under the trade name) having a characteristic of generating heat at a constant temperature when an applied voltage is applied, and has electrodes on both sides thereof. .

FIG. 2 is a top view of the insulating case, and FIG. 3 is a front view. The insulating case includes a cylindrical main body 80 and a main body 80.
It is composed of a lid 90 attached by a screw 95 on the top. The body 80 is made of an insulating plastic material,
It has a thin cylindrical portion 82. A slit 85 is provided in the thin-walled cylindrical portion 82. The open end of the thin-walled cylindrical portion 82 is formed in a shape that covers the receiving member 50 and the flange portion of the casing 52, and has a claw portion 86 that protrudes inward.

By utilizing the elastic deformation of the thin-walled cylindrical portion 82 made of plastic by the slit 85, the main body 80 is moved to the valve main body 1.
By pushing it toward the 0 side, the claw 86 is received by the receiving member 50.
The main body 80 is attached by engaging with the flange portion of. A waterproof packing 55 is interposed between the main body 80 and the cap 54. A plastic lid 90 is attached by screws 95 to the upper portion of the main body 80 of the insulating case. A groove 87 is formed in the body 80 of the insulating case, and at the same time when the lead plate 74 of the electrode terminal 74 is fitted into the groove 87, the lid 90 of the insulating case has a protrusion 92 that engages with the groove 87 of the body 80. It holds the lead plate of the electrode terminal 74.

The lead plate of the other electrode 72 is sandwiched between the upper surface of the body 80 of the insulating case and the lid 90. Electrode terminal 7
The body of the second disc spring is pressed by the lid 90, and the electric heater 70 and the two electrode terminals 72 and 74 are brought into pressure contact with each other with an appropriate pressure. When power is supplied to the electrode terminals 72 and 74, the electric heater 70
Generates heat at a predetermined temperature and heats the shape memory coil spring 60 via the cap 54 having good thermal conductivity. The shape memory coil spring 60 expands by being heated to a predetermined temperature, and pushes the valve body 42 downward in the direction away from the orifice 16 against the spring force of the two springs 62 and 38, and the port 1
It connects between 2 and 14. By this action, the valve is opened.

When the power supply to the electric heater 70 is cut off, the heat generation of the electric heater is stopped and the temperature of the shape memory coil spring 60 is also lowered. As a result, the spring force of the shape memory coil spring 60 decreases, and the spring forces of the bias spring 62 and the support spring 38 become larger. Due to this force, the valve element 42 is pressed against the orifice 16 to close the valve.

FIG. 5 is an explanatory view showing another embodiment of the on-off valve of the present invention. For example, a refrigeration system for an air conditioner and a refrigerator, which is entirely denoted by reference numeral 100, is configured as follows.
That is, the compressor 110, the condenser 112, and the expansion valve 1
16 and an evaporator 120, the gas refrigerant pressurized by the compressor 110 is passed through the outlet pipe 111 to the condenser 12
Sent to and liquefied. The liquid refrigerant is sent to the expansion valve 116 via the pipe 114, and expands to lower the liquid temperature. The low-temperature refrigerant evaporates while passing through the evaporator 120 and cools the air in the room or the refrigerator by heat exchange, and the gas refrigerant that has left the evaporator 120 passes through the outlet pipe 122 to the suction port of the compressor 110. The refrigeration system is configured by being returned to. In such a refrigeration system, the temperature sensing tube 1 detects a temperature change in the outlet pipe 122 of the evaporator 120.
The temperature is sensed at 18, and the pressure due to the change is transmitted to the expansion valve 116 via the pipe 119, and the diaphragm of the expansion valve is operated to adjust the valve opening of the expansion valve 116.

In this type of refrigeration system, if frost adheres to the evaporator, the refrigerating capacity is reduced. In order to remove this frost, a high-temperature gas refrigerant is periodically sent to the evaporator to defrost the evaporator. Outlet pipe 11 of compressor 110
Since the discharged gas refrigerant from 1 is a high temperature gas, the outlet pipe 111 is branched to pass the on-off valve 130 of the present invention through the manual valve 132 and the evaporator 120 through the pipe 134.
Is fed into the inlet tube of the tank through a metering orifice 140. The manual valve 132 adjusts the amount of refrigerant and may be omitted.

The expansion valve 116 closes the orifice when hot gas is sent to the outlet side. Therefore, the hot gas is sent to the evaporator 120 to heat the evaporator and defrost it. For defrosting, the terminals 72 and 74 of the on-off valve 130
For example, in the case of defrosting in a refrigerator, a timer or the like causes a current to flow at regular intervals to open the valve, and after a set time, the valve is closed to complete the defrosting cycle. In the on-off valve of the present invention, since the opening and closing of the valve is achieved gently, the expansion valve 116
The pressure fluctuation due to the above is reduced, and the life of the entire refrigeration system is extended.

FIG. 6 is a diagram showing the configuration of another embodiment of the present invention. This embodiment shows a refrigerating system by a refrigerating cycle which is constructed by using the opening / closing valve of the present invention in place of the solenoid valve 4 in the conventional example shown in FIG.
1 is the opening / closing valve of FIG. 1, the inlet port 12 of the valve 131 is on the liquid receiver 3 side, and the outlet port 14 is the expansion valve 5b.
Connected to each side. 6 that are the same as those in FIG. 4 indicate the same or equivalent items. According to the present embodiment,
Since the opening / closing valve 131 is opened / closed gently, when using the evaporator 6b in the rear seat, the opening / closing valve 13
Even when the valve 131 is opened by energizing the terminals 72 and 74 of No. 1, no vibration noise is generated, and since the use of the evaporator 6b is stopped, the energization of the valve 131 is stopped, Even if the valve 131 is closed, the water hammer effect can be prevented.

FIG. 7 is a refrigeration system using a refrigeration cycle suitable for an air conditioner showing another embodiment of the present invention using the on-off valve according to the present invention, and it is compressed again after the compressor is stopped. It is possible to prevent the water hammer effect caused by the rapid flow of the refrigerant when the machine is restarted. In the figure, 133 is an opening / closing valve according to the present invention, 135 is a pressure switch, 136 is a temperature controller, and the same reference numerals as those in FIG. 5 denote the same or equivalent components. In such a configuration, the control signal from the temperature controller 136 stops the energization of the terminals 72 and 74 of the opening / closing valve 133, the opening / closing valve 133 is closed, the circulation of the refrigerant is stopped, and the pressure switch 135 causes the pressure switch 135 to decrease due to the pressure decrease. It opens and the compressor 110 stops. At this time, the compressor 11
When 0 is restarted and the refrigeration cycle is operated, the signal from the temperature controller 136 is applied to the terminals 72 and 74 of the opening / closing valve 133 to open the opening / closing valve 133, and the compressor 110 is restarted. It This open / close valve 13
When the valve 3 is opened, the refrigerant rapidly flows into the expansion valve 116 to generate a water hammer effect when the valve opening operation is fast as in the case of the solenoid valve, but the valve opening operation of the valve 133 is Since the refrigerant is gentle, the refrigerant accumulates in the expansion valve 116 relatively slowly, and the water hammer effect can be prevented.

When the compressor 110 is restarted, the on-off valve 133 is opened and then restarted in order to avoid the following phenomenon. That is, when the compressor 110 is stopped, the refrigerant in the cycle is balanced, the pressure of the evaporator 120 is increased, the pressure switch 135 is closed, and the switch 1
When 35 is closed, the compressor 110 is started even though the refrigerant does not circulate in the cycle, and when it is started, the switch 135 is opened and the compressor 110 is stopped due to the decrease in the low pressure. Become the compressor 110
This is to avoid the occurrence of a so-called short cycle phenomenon in which the stop and start of is repeated.

[0021]

As described above, the present invention provides an on-off valve which is disposed in a liquid cycle to open and close a liquid flow path,
A force required to open and close the valve is generated by a coil spring and a bias spring made of a shape memory alloy, and an electric heater is used as a heating means of the shape memory spring. With this configuration, the opening / closing operation of the valve becomes slower than that of a solenoid valve,
The sudden change of the hydraulic pressure in the pipe is prevented. Therefore,
Pulsations caused by sudden changes in hydraulic pressure and so-called water hammer phenomenon can be prevented, noise can be prevented, and durability of the device can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing the overall structure of an on-off valve according to the present invention.

FIG. 2 is a front view of an insulating case.

FIG. 3 is a plan view of an insulating case.

FIG. 4 is a system configuration diagram of a car air conditioner to which the present invention is applied.

FIG. 5 is an explanatory view showing another embodiment of the on-off valve of the present invention.

FIG. 6 is a diagram showing a configuration of an embodiment of a refrigeration system using the on-off valve of the present invention.

FIG. 7 is a diagram showing the configuration of another embodiment of the refrigeration system using the on-off valve of the present invention.

[Explanation of symbols]

 10 valve body 12 inlet port 14 outlet port 16 orifice 30 cap 38 coil spring 40 stem 42 valve body 60 shape memory coil spring 62 bias spring 70 electric heater 80 insulating case

Claims (5)

[Claims] 1. A liquid inlet port and an outlet port,
The orifice formed between the inlet ports, the valve body that changes the opening of the orifice, the spring means that urges the valve in the direction of decreasing the opening of the orifice, and the opening of the orifice An on-off valve including a shape memory alloy spring for urging a valve body in a direction of increasing the size and an electric heater for heating the shape memory alloy spring. 2. The on-off valve according to claim 1, further comprising a bias spring that biases the valve body to a position where the valve body closes the orifice when the electric heater is not generating heat. 3. A refrigeration cycle comprising a compressor, a condenser for condensing the refrigerant from the compressor, an expansion valve for expanding the refrigerant from the condenser, and an evaporator for evaporating the refrigerant from the expansion valve. In the system, the compressor and the condenser are connected to each other and the expansion valve and the evaporator are connected to each other via an opening / closing valve, and the opening / closing valve has an inlet port and an outlet port of the liquid refrigerant. Between the orifices, a valve body for varying the opening of the orifice, spring means for urging the valve in a direction to reduce the opening of the orifice, and increasing the opening of the orifice. A spring made of a shape memory alloy for urging the valve body in the direction, and an electric heater for heating the spring made of the shape memory alloy are provided. Refrigeration system but is input from the outlet port is the discharge refrigerant output, and wherein the flowing into the evaporator. 4. A refrigeration system comprising a refrigeration cycle including a plurality of refrigerant evaporators connected in parallel to one refrigerant compressor and an opening / closing valve for introducing a refrigerant to at least one of the plurality of refrigerant evaporators. In the above, the open / close valve is
An orifice part that has an inlet port and an outlet port for the liquid refrigerant and is formed between the inlet port, a valve body that changes the opening of the orifice part, and a valve body that reduces the opening of the orifice part. Refrigeration characterized by comprising a spring means for urging, a spring made of a shape memory alloy for urging the valve body in a direction of increasing the opening of the orifice portion, and an electric heater for heating the spring made of the shape memory alloy. system. 5. A compressor, a condenser for condensing the refrigerant from the compressor, an expansion valve for expanding the refrigerant from the condenser, an on-off valve connected between the condenser and the expansion valve, and an expansion valve. In a refrigeration system comprising a refrigeration cycle including an evaporator for evaporating the refrigerant from the above, the opening / closing valve has an inlet port and an outlet port for the liquid refrigerant, and an orifice portion formed between the inlet ports, and an orifice portion. Of the shape memory alloy that urges the valve element to increase the opening of the orifice portion, spring means that urges the valve element to decrease the opening degree of the orifice portion, Refrigeration system, which comprises a spring and an electric heater for heating a spring made of a shape memory alloy.