JP4484752B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator having a defrosting heater that operates a refrigeration cycle by circulating a combustible refrigerant and defrosts a cooler.

  In recent refrigerators, in consideration of environmental destruction, a refrigeration cycle is operated by circulating a combustible refrigerant such as isobutane. Cold air generated by a cooler on the low temperature side of the refrigeration cycle is sent into the storage chamber, and the storage chamber is cooled. When the frost is generated in the low-temperature cooler, the cooling capacity is lowered. Therefore, a defrost heater for defrosting the cooler is provided.

  FIG. 8 is a side view showing a conventional defrosting heater of a refrigerator. The defrost heater 30 has a heating wire 11 that generates heat when energized, and the heating wire 11 is covered with a tubular container 13. Lead wires 12 are provided at both ends of the heating wire 11. The container 13 consists of a double glass tube having an inner container 13a and an outer container 13b. Caps 14 and 15 made of rubber or the like are fitted on the end surface of the container 13, and the inside of the inner container 13a is sealed. The caps 14 and 15 are provided with insertion holes 14a and 15a (15a not shown) for tightly fitting the lead wires 12.

  When the heating wire 11 is energized via the lead wire 12, the heating wire 11 generates heat, and the cooler is defrosted by the radiant heat released from the surface of the container 13. In addition, since the lead wire 12 is tightly fitted and the inner container 13a is hermetically sealed by the caps 14 and 15, the heat generating wire 11 is not contacted when the flammable refrigerant leaks. Thereby, the safety | security of the refrigerator is ensured.

  However, when the defrost heater 30 is energized to the heating wire 11, there is a risk that the internal pressure of the inner container 13a increases and the caps 14 and 15 are removed. For this reason, Patent Document 1 discloses a defrost heater in which a pressure adjustment hole is provided in one cap 14. Thereby, when the internal pressure of the inner container 13a rises, the gas in the inner container 13a can be released to the outside and the caps 14 and 15 can be prevented from falling off.

  When energization of the heating wire 11 is stopped and the internal pressure of the inner container 13a is reduced, combustible refrigerant flows into the inner container 13a from the outside through the pressure adjustment hole. At this time, since the cross-sectional area of the pressure adjusting hole is small, the flame does not propagate even if the heating wire 11 and the combustible refrigerant come into contact with each other and ignite.

  Patent Document 2 discloses a defrost heater in which a check valve is provided on one cap 14. A cylinder is fitted at a position deviated from the center of the cap 14, and a check valve made of rubber is attached to the cylinder. The check valve opens in a direction in which gas flows out from the inner container 13a, and when the internal pressure of the inner container 13a rises, the gas in the inner container 13a is released to the outside to prevent the caps 14 and 15 from falling off. it can.

Japanese Patent Laid-Open No. 2003-343969 (page 3 to page 6, FIG. 5) JP-A-2004-257616 (pages 5 to 9, FIG. 1)

  However, according to the refrigerator disclosed in Patent Document 1, when the combustible refrigerant flows into the inner container 13a through the pressure adjustment hole and ignites by contact with the heating wire 11, the defrosting heater fails. there were.

  According to the refrigerator disclosed in Patent Document 2, since the check valve is provided at a position deviated from the center of the cap 14, there is a problem that the cap 14 becomes large. Further, since the check valve and the cylinder are attached to the cap 14, there is a problem that the number of parts increases and the cost increases.

  An object of the present invention is to provide a refrigerator having a defrosting heater that is small and can prevent failure. Moreover, an object of this invention is to provide the refrigerator which has the defrost heater which can reduce cost.

In order to achieve the above object, the present invention provides a refrigerator including a cooler on a low temperature side of a refrigeration cycle operated by circulating a combustible refrigerant, and a defrost heater for defrosting the cooler, The defrost heater includes a heating wire that generates heat when energized, a tubular container that covers the heating wire and has an open end surface, a lead wire that is connected to a tip of the heating wire, and closes the end surface of the container and the lead. A cap provided with an insertion hole through which a wire is inserted, through which the lead wire is inserted, and in contact with the lead wire, the valve opens in a direction in which gas flows out from the container due to a pressure difference between the inside and outside of the container A stop valve is provided on the inner wall of the insertion hole.

  According to this configuration, cold air is generated by the cooler on the low temperature side of the refrigeration cycle, and is sent to the storage room. A defrost heater is provided in the vicinity of the cooler. The defrost heater is provided with a heating wire in a tubular container, and the end surface of the container is closed by a cap. The heating wire is energized through a lead wire inserted through an insertion hole provided in the cap. A check valve projects from the insertion hole, and the check valve opens when the internal pressure of the container rises due to energization of the heating wire. Thereby, the gas in a container is discharged | emitted through an insertion hole. When energization of the heating wire stops and the internal pressure of the container decreases, the insertion hole is sealed by the check valve.

In the refrigerator configured as described above, the cap may be made of an elastic body, and the check valve may be integrally formed, and the check valve may be reduced in diameter in a direction away from the container toward the outside. It is a feature.
The check valve is concentric with the lead wire insertion hole of the cap, is reduced in diameter in a direction away from the container, and is inserted with only a single lead wire.

  Further, the present invention provides a refrigerator including a cooler on a low temperature side of a refrigeration cycle operated by circulating a combustible refrigerant and a defrost heater for defrosting the cooler, wherein the defrost heater is energized A heating wire that generates heat, a tubular container that covers the heating wire and that has an open end surface, a lead wire that is connected to the tip of the heating wire, closes the end surface of the container, and the lead wire is closely fitted And a cap provided with an insertion hole, wherein the inside of the container is set to a negative pressure when the heating wire is not energized.

  According to this configuration, cold air is generated by the cooler on the low temperature side of the refrigeration cycle, and is sent to the storage room. A defrost heater is provided in the vicinity of the cooler. The defrost heater is provided with a heating wire in a tubular container, and the end surface of the container is closed by a cap. The heating wire is energized through a lead wire inserted into an insertion hole provided in the cap. The lead wire is tightly fitted in the insertion hole, and the container is sealed. The inside of the container is maintained at a negative pressure when the heating wire is turned off.

  Moreover, the present invention is characterized in that, in the refrigerator having the above-described configuration, the inside of the container is set to a negative pressure when the heating wire is energized.

  According to the present invention, in the refrigerator configured as described above, the cap is made of an elastic body, and the cap is tightened around the lead wire. According to this configuration, the cap around the lead wire is tightly bound by the binding band or the like, and the space between the lead wire and the insertion hole is sealed.

  Moreover, the present invention is characterized in that the end face of the container is closed by the cap in an atmosphere of 30 ° C. or higher in the refrigerator having the above configuration. According to this structure, after sealing a container with a cap, a defrost heater is installed in a refrigerator. During the operation of the refrigerator, the defrost heater becomes low temperature, and the inside of the container becomes negative pressure.

  According to the present invention, in the refrigerator configured as described above, the container is formed of a double glass tube. According to this configuration, the heating wire is covered with the inner container made of the glass tube, and the inner container is covered with the outer container made of the glass tube.

  According to the present invention, since the check valve protrudes from the insertion hole provided in the cap of the defrost heater, the cap is downsized to prevent the inflow of the combustible refrigerant into the container, and the removal by the ignition of the combustible refrigerant. Failure of the frost heater can be prevented. Moreover, it is not necessary to provide a cylinder or the like to which the check valve is attached as in the conventional example, and the cost of the refrigerator can be reduced by reducing the number of parts.

Further, according to the present invention, the cap is made of an elastic body and integrally forms a check valve, and the check valve is reduced in diameter in a direction away from the container toward the outside, so that the number of parts is reduced and the check valve is reduced. Can be formed easily, and the cost of the refrigerator can be further reduced.

  According to the present invention, since the lead wire is tightly fitted into the insertion hole and the inside of the container is made negative when the heating wire is not energized, the inner pressure of the container can be lowered when the heating wire is energized. Therefore, it is possible to prevent the cap from falling off and downsize the cap, to prevent the inflow of the combustible refrigerant into the container, and to prevent the defrost heater from being broken due to the ignition of the combustible refrigerant. Further, there is no need to provide a check valve, a cylinder to which the check valve is attached, or the like by a separate member, and the number of parts can be reduced and the cost of the refrigerator can be reduced.

  In addition, according to the present invention, since the inside of the container is set to a negative pressure when the heating wire is energized, it is possible to more reliably prevent the cap from falling off.

  Further, according to the present invention, the cap is made of an elastic body, and the cap is tightened by surrounding the lead wire, so that the space between the cap insertion hole and the lead wire can be more reliably sealed, and the cap and the heating wire Can be integrated to more reliably prevent the cap from falling off.

  Further, according to the present invention, since the end face of the container is closed with the cap in an atmosphere of 30 ° C. or higher, the inside of the container can be easily set to a negative pressure.

  Further, according to the present invention, since the container is composed of a double glass tube, even if the inner container is damaged by covering the heating wire twice, the contact between the flammable refrigerant and the heating wire can be avoided and the safety can be improved. Can do.

  Embodiments of the present invention will be described below with reference to the drawings. For convenience of explanation, the same parts as those in the conventional example shown in FIG. 1 and 2 are a perspective view and a front view showing the refrigerator of the first embodiment. The refrigerator 1 has a refrigerator compartment 2 opened and closed by a door 2a at the top, and a vegetable compartment 3 opened and closed by a door 3a on the left side of the bottom. On the right side of the lower part of the refrigerator 1, an ice making room 4 and a freezing room 5 are arranged vertically. The ice making room 4 and the freezing room 5 are opened and closed by doors 4a and 5a, respectively.

  3 and 4 are a front sectional view and a side sectional view of the refrigerator 1. Behind the refrigerator compartment 2 and the freezer compartment 5 are provided cold air passages 8 and 9 communicating with each other. A cooler 6 connected to a compressor (not shown) is disposed in the cool air passage 9. The refrigerant compressed by the compressor changes into a high-temperature and high-pressure gas refrigerant and liquefies while dissipating heat in a condenser (not shown). The liquefied refrigerant is decompressed so as to be easily vaporized by a capillary tube (not shown), and vaporized by the cooler 6 to take heat away from the surroundings. Then, the refrigerant returns to the compressor. As a result, the refrigeration cycle is operated, and the air flowing through the cool air passage 9 exchanges heat with the cooler 6 to generate cool air. In addition, a flammable refrigerant such as isobutane is used for the refrigerant in consideration of environmental destruction.

  A blower 7 is disposed above the cooler 6. As the blower 7 is driven, cool air flows through the cool air passage and is sent to the ice making chamber 4. The cold air flowing through the ice making chamber 4 flows into the freezer compartment 5 and returns from the freezer compartment 5 to the cold air passage 9. Thereby, the ice making room 4 and the freezing room 5 are cooled. Further, by opening the damper 18 provided between the cold air passage 8 and the cold air passage 9, the cold air flows through the cold air passage 8 and is discharged from the discharge port 2b to the refrigerator compartment 2. The cold air flowing through the refrigerator compartment 2 flows into the vegetable compartment 3 through the outlet 2c and returns from the vegetable compartment 3 to the cold air passage 9. Thereby, the refrigerator compartment 2 and the vegetable compartment 3 are cooled.

  Frost is generated in the cooler 6 on the low temperature side of the refrigeration cycle. A defrost heater 10 is provided below the cooler 6. When the defrost heater 10 is energized, the cooler 6 is defrosted. FIG. 5 is a side view showing the defrost heater 10. The defrosting heater 10 has a heating wire 11 that generates heat when energized, and the heating wire 11 is covered with a tubular container 13. Lead wires 12 are provided at both ends of the heating wire 11.

  The container 13 is composed of a double glass tube having a tubular inner container 13a and a tubular outer container 13b covering the inner container 13a. Thereby, even if the heat generating wire 11 is covered twice and the inner container 13a is damaged, the contact between the combustible refrigerant and the heat generating wire 11 can be avoided and the safety can be improved. Caps 14 and 15 made of an elastic material such as rubber or soft resin are fitted on the end surface of the container 13. The cap 15 is provided with an insertion hole (not shown) for closely fitting the lead wire 12.

  FIG. 6 shows a perspective view of the cap 14. The cap 14 is provided with an insertion hole 14a through which the lead wire 12 is inserted. A check valve 16 projects from the inner wall of the insertion hole 14a. The check valve 16 is formed integrally with the cap 14 and is reduced in diameter toward the outside in a substantially conical shape. The side of the check valve 16 having a smaller diameter is in close contact with the lead wire 12 so that the inner container 13a is sealed.

  When the heating wire 11 is energized via the lead wire 12, the heating wire 11 generates heat, and the cooler 6 is defrosted by the radiant heat released from the surface of the container 13. When the internal pressure of the inner container 13a rises due to heat generated by the heating wire 11, the check valve 16 expands in diameter and the gas in the inner container 13a flows out to the outside. Thereby, falling off of the caps 14 and 15 can be prevented.

  Further, since the check valve 16 is reduced in diameter in a direction away from the inner container 13a, the check valve 16 and the lead wire 12 are in close contact with each other even when the internal pressure of the inner container 13a is reduced when the heating wire 11 is de-energized. State is maintained. Thereby, since the external gas does not flow into the inner container 13a, even if the flammable refrigerant leaks, the contact with the heating wire 11 can be avoided and the failure of the defrost heater 10 due to the ignition of the flammable refrigerant can be prevented. it can.

  According to this embodiment, since the check valve 16 protrudes from the insertion hole 14a provided in the cap 14, the cap 14 can be reduced in size. Moreover, since the cap 14 can be formed in the same shape as the conventional defrost heater 30 shown in FIG. 8, it is not necessary to change the shape of the container 13 and compatibility can be maintained.

  Moreover, it is not necessary to provide a cylinder or the like to which a check valve is attached as a separate member as in Patent Document 2 described above, and the cost of the refrigerator can be reduced by reducing the number of parts. In addition, since the check valve 16 is integrally formed with the cap 14 made of an elastic body such as rubber or soft resin, the number of parts can be reduced and the check valve 16 can be easily formed. The cap 15 may be provided with a check valve 16.

  Next, FIG. 7 is a side view showing a defrosting heater of the refrigerator of the second embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. The refrigerator of this embodiment differs in the structure of a defrost heater with respect to 1st Embodiment. Other parts are the same as those of the first embodiment.

  The defrosting heater 20 has a heating wire 11 that generates heat when energized, and the heating wire 11 is covered with a tubular container 13. Lead wires 12 are provided at both ends of the heating wire 11. The container 13 consists of a double glass tube having an inner container 13a and an outer container 13b. Caps 14 and 15 made of an elastic material such as rubber or soft resin are fitted on the end surface of the container 13, and the inside of the inner container 13 a is sealed. The caps 14 and 15 are provided with insertion holes 14a and 15a (15a not shown) for tightly fitting the lead wires 12.

  The caps 14 and 15 are formed longer in the axial direction than the cap of the conventional defrosting heater 10 shown in FIG. 8, and the periphery thereof is tightened by a binding band 17. As a result, the caps 14 and 15 can be reliably in close contact with the lead wire 12 to more reliably seal between the insertion holes 14 a and 15 a and the lead wire 12.

  The caps 14 and 15 are fitted on the container 13 in an atmosphere of 30 ° C. or higher. Thereby, since the defrost heater 20 arrange | positioned in the cold air | gas channel | path 9 becomes low temperature, the inside of the inner side container 13a is maintained at a negative pressure. When the heating wire 11 is energized via the lead wire 12, the heating wire 11 generates heat, and the cooler is defrosted by the radiant heat released from the surface of the container 13.

  According to the present embodiment, since the lead wire 12 is tightly fitted and the inner container 13a is sealed by the caps 14 and 15, the flammable refrigerant does not come into contact with the heating wire 11 when leaking. Thereby, cap 14 and 15 can be reduced in size, the inflow of the combustible refrigerant | coolant into the container 13 can be prevented, and failure of the defrost heater 20 by ignition of a combustible refrigerant | coolant can be prevented. In addition, there is no need to provide a check valve or a cylinder to which the check valve is attached shown in Patent Document 2 as a separate member, and the number of parts can be reduced and the cost of the refrigerator 1 can be reduced.

  Further, since the inside of the container 13 is maintained at a negative pressure at least when the heating wire 11 is not energized, the internal pressure of the container 13 can be lowered when the heating wire 11 is energized. Therefore, the caps 14 and 15 can be prevented from falling off. When the heat generation amount of the heating wire 11 is controlled so that the inside of the container 13 is maintained at a negative pressure even when the heating wire 11 is energized, the caps 14 and 15 can be more reliably prevented from falling off.

  In addition, since the periphery of the caps 14 and 15 is tightened by the binding band 17 surrounding the lead wire 12, the caps 14 and 15 and the heating wire 11 are integrated to more reliably prevent the caps 14 and 15 from falling off. Can do.

  According to this invention, it can utilize for the refrigerator provided with the defrost heater.

The perspective view which shows the refrigerator of 1st Embodiment of this invention. The front view which shows the refrigerator of 1st Embodiment of this invention. Front sectional drawing which shows the refrigerator of 1st Embodiment of this invention. Side surface sectional drawing which shows the refrigerator of 1st Embodiment of this invention. The side view which shows the defrost heater of the refrigerator of 1st Embodiment of this invention. The perspective view which shows the cap of the defrost heater of the refrigerator of 1st Embodiment of this invention. The side view which shows the defrost heater of the refrigerator of 2nd Embodiment of this invention. Side view of a conventional refrigerator defrost heater

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Freezing room 3 Vegetable room 4 Ice making room 5 Freezing room 6 Cooler 7 Blower 8, 9 Cold passage 10, 20, 30 Defrost heater 11 Heating wire 12 Lead wire 13 Container 13a Inner container 13b Outer container 14, 15 Cap 14a Insertion hole 16 Check valve 17 Binding band 18 Damper

Claims (4)

In a refrigerator including a cooler on a low temperature side of a refrigeration cycle that is operated by circulating a combustible refrigerant and a defrost heater that defrosts the cooler, the defrost heater is a heating wire that generates heat when energized. And a cap having a tubular container that covers the heating wire and has an open end surface, a lead wire that is connected to the tip of the heating wire, and an insertion hole that closes the end surface of the container and through which the lead wire is inserted. A check valve that is inserted in the lead wire and is in contact with the lead wire and opens in a direction in which gas flows out of the container due to a pressure difference between the inside and outside of the container, is provided on the inner wall of the insertion hole. A refrigerator characterized by that. 2. The refrigerator according to claim 1, wherein the cap is made of an elastic body and integrally forms the check valve, and the check valve is reduced in diameter in a direction away from the container toward the outside .   3. The check valve according to claim 1, wherein the check valve is concentric with a lead wire insertion hole of the cap, is reduced in diameter in a direction away from the container, and only a single lead wire is inserted. Refrigerator. The refrigerator according to claim 1 , wherein the container is made of a double glass tube.

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