JP2020046409A - Dew condensation sensor and refrigerator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dew condensation sensor which not only prevents the dew condensation detection portion from being damaged but also prevents water from accumulating on a protective cover even if water droplets excessively adhere to the dew condensation detection portion due to abnormal dew condensation. In order to solve the above-mentioned conventional problems, the dew condensation sensor of the present invention has at least a dew condensation detection element provided on a wiring substrate, and an element cover for covering the dew condensation detection element is provided and the inside of the element cover is provided. The element cover is provided with a through hole for passing the dew condensation water generated in the above, which can prevent the dew condensation detection element from being damaged especially during the mounting work, and can cover even if excessive dew condensation occurs in the element cover. Since it is discharged from the inside, highly accurate dew condensation detection is possible. [Selection diagram] Fig. 1

Description

  The present invention relates to a dew condensation sensor which detects dew condensation in advance to prevent dew condensation, and a refrigerator using the same.

  In recent years, although the airtightness of the house has been improved and the house has become comfortable, there is a problem of dew condensation on a wall surface, a ceiling surface, a closet, and the like, and it is required to predict the dew condensation in advance.

  In addition, even in refrigerators having improved heat insulation performance, a means is employed for detecting the temperature and humidity and heating the heater to prevent dew condensation on the surface of the main body and the inner wall surface of the refrigerator. However, if the vegetable storage case is made to have a sealed structure to improve the freshness of the vegetables and stored at high humidity, the case wall surface will condense, causing a problem that the vegetables are rotten due to the influence of the dew condensation water.

  To solve the problem of detecting such dew condensation in advance, some devices detect the dew condensation faster than the surroundings by lowering the dew point temperature of the device by lowering the temperature of the device to be detected than the ambient temperature. (For example, see Patent Document 1).

  FIG. 11 shows a side view of a conventional condensation sensor described in Patent Document 1. As shown in FIG. In FIG. 11, the resistance value changes when water droplets adhere between the comb-shaped electrodes of the dew detection unit 1, and the cooling panel 3 closely adheres to the opposite side to the detection surface with good heat conduction, and further sequentially heats the heating panel. 4. The heat insulating material layer 5 is in close contact, and these members constitute a dew condensation sensor. As a specific detection method, when dew condensation is detected, only the cooling panel 3 is cooled by a device such as a Peltier element, and the temperature of the contact portion 2a is reduced to a predetermined temperature, whereby the dew condensation is detected on the dew condensation detection unit 1 earlier than the surroundings. Let it. In addition, in order to quickly detect the dew condensation on the next time, only the heating panel 4 is heated by a device such as a surface heating heater after the dew condensation, and the temperature of the contact portion 2b is raised to a predetermined temperature, so that the dew detection unit 1 is dried more quickly. When the dew condensation sensor is attached to the main body, a heat insulating material layer 5 is provided to eliminate the influence of heat from the main body. With such a configuration and operation, dew condensation is detected in advance.

JP-A-4-54444

  However, in the above-described conventional configuration, when the dew condensation sensor is attached to the main body because the dew detection unit 1 is exposed, there is a possibility that scratches may occur. As a countermeasure, it is conceivable to attach a protective cover to the dew condensation detection unit 1. However, if a cover with good airtightness is attached, if large water droplets adhere to the detection and detection unit 1 due to abnormal dew condensation, water will accumulate in the cover and cannot be discharged. Had issues.

  The present invention solves the above-described problem, and not only prevents the dew condensation detecting portion from being damaged, but also provides a dew condensation sensor that does not collect water on the protective cover even if water droplets excessively adhere to the dew detecting portion due to abnormal dew condensation. The purpose is to provide.

  In order to solve the above-mentioned conventional problems, a dew condensation sensor of the present invention has at least a dew detection element provided on a wiring board, has an element cover for covering the dew detection element, and has a dew condensation generated in the element cover. A through-hole through which water passes is provided in the element cover.

  Accordingly, the dew condensation detecting element can be prevented from being damaged particularly during the mounting operation, and even if excessive dew is generated in the element cover, the dew is discharged from the inside of the cover, so that highly accurate dew detection can be performed.

  Since the dew condensation sensor of the present invention covers the dew detection unit for detecting dew condensation with the element cover provided with the opening, even when abnormal excessive dew condensation occurs, water does not accumulate in the element cover and correct dew condensation detection is performed. , And the deterioration of the reliability of the element due to the added state can be prevented.

FIG. 2 is a plan view of the condensation sensor according to the first embodiment of the present invention. Side view of a dew condensation sensor according to Embodiment 1 of the present invention FIG. 3 is a plan view of the dew condensation sensor according to the first embodiment of the present invention, with a through hole for an element cover. FIG. 3 is a side view of the dew condensation sensor according to the first embodiment of the present invention with a through hole for an element cover. The figure which shows the relationship between the dew point by the temperature and humidity of the dew condensation sensor and sensor output by Embodiment 1 of this invention. Longitudinal sectional view of a refrigerator using a dew condensation sensor on the back according to a second embodiment of the present invention. Longitudinal sectional view of a vegetable room of a refrigerator using a dew condensation sensor on the back according to Embodiment 2 of the present invention. The principal part enlarged longitudinal sectional view of the vegetable room of the refrigerator which used the condensation sensor by the back according to Embodiment 2 of this invention. Longitudinal sectional view of a vegetable room of a refrigerator using a dew condensation sensor on a top surface according to a second embodiment of the present invention. Embodiment 2 Enlarged longitudinal sectional view of a vegetable compartment of a refrigerator using a condensation sensor on a top surface according to a second embodiment of the present invention. Side view of conventional dew sensor

  The invention according to claim 1 has at least a dew detection element provided on a wiring board, and has an element cover for covering the dew detection element, and has a through hole through which dew condensation water generated in the element cover passes. By providing the cover, it is possible to install a highly reliable condensation sensor because it does not touch the condensation detection element with bare hands or hit it with a tool, etc. when mounting the condensation sensor. Furthermore, even if excessive water droplets adhere to the element cover due to abnormal condensation or the like, since water can be discharged from the through-hole, correct dew detection can be performed, and deterioration of the reliability of the element due to a hydrated state can be prevented.

  According to a second aspect of the present invention, in the first aspect of the present invention, since a plurality of the through holes are provided, the dew water in the element cover is more easily drained, so that the mounting position of the dew sensor is restricted. Conditions can be relaxed.

  According to a third aspect of the present invention, in the first or second aspect of the invention, since the through hole is provided in a vertical direction, an abnormal water droplet in the element cover tends to fall from the through hole by gravity. Therefore, the drainage of water can be further improved.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the area of the through-hole is smaller than the surface tension of the dew condensation water accumulated in the element cover due to its own weight. By making the size larger, it is physically impossible for water to remain as water droplets in the element cover, so that the reliability against abnormal dew condensation can be further improved.

  According to a fifth aspect of the present invention, there is provided a refrigerator having the dew condensation sensor according to any one of the first to fourth aspects and a vegetable compartment, wherein the refrigerator is provided with the dew condensation sensor in a coolest part of the vegetable compartment. By using the cold temperature of the conventional refrigerator to cool the dew condensation sensor more than other parts, it is possible to detect dew condensation in advance at low cost, and to preserve the vegetables in high humidity by substantially closing the vegetable case Becomes possible. Further, by disposing the through-holes vertically downward with respect to the space inside the element cover, it becomes possible to improve drainage when abnormal condensation occurs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited by the embodiment.

(Embodiment 1)
FIG. 1 is a plan view of a condensation sensor according to Embodiment 1 of the present invention, FIG. 2 is a side view of the condensation sensor according to Embodiment 1, and FIG. FIG. 4 is a plan view, FIG. 4 is a side view of the dew condensation sensor according to the first embodiment with an element cover through-hole, and FIG. 5 is a diagram illustrating the relationship between the dew point due to temperature and humidity and the sensor output of the dew condensation sensor according to the first embodiment. .

  1 to 4, a dew condensation detecting element 11 is mounted on one surface of a wiring board 12, a detection circuit portion 14 including a plurality of electronic components 13 is mounted on the same surface, and an electric connection is made to an external connection portion 15 by a conductor pattern 17. The dew condensation detecting element 11 is covered with an element cover 16 so that the whole is hidden. Although not shown, a slight gap between the wiring board 12 and the element cover 16 such that moisture can pass therethrough is provided. Is provided. The above components constitute the dew condensation sensor 18. In addition, the other surface of the wiring board 12 has no mounted components and has a cooling surface, and has a structure in which the condensation detecting element 11 is cooled via the wiring board 12 by cooling from a cooling source. The wiring board 12 is generally made of a material such as paper phenol / composite / glass epoxy and has a thickness of 1.6 mm, but a thin base material may be used to increase the cooling efficiency from a cooling source, or A processed product of an insulating and high thermal conductive resin material having a high thermoelectric coefficient may be used.

  As the dew condensation detecting element 11, it is preferable that the change in physical quantity between a dry state without water adhesion and a dew condensation state with water adhesion is large. Here, a mixture of a hygroscopic resin such as polyamide and a conductive powder such as carbon is used. And In general, only a resin used for a capacitance type humidity sensor has poor accuracy at high humidity of 90% RH or more, and it is impossible to discriminate between high humidity and dew condensation. Therefore, when the mixture is used, the moisture absorbing resin swells very greatly during dew condensation, and the contact ratio between the conductors is extremely reduced. Therefore, the change in the resistance value during drying and during dew condensation can be greatly increased. For example, a resistance value of several kΩ in a normal dry state becomes high as several hundred kΩ when dew condensation occurs, and can be regarded as a change amount of 100 times or more. The mixture can be processed into a paste-like material, and can be directly printed and formed between the conductive circuit patterns 17 on the wiring board 12. Alternatively, if a mixture is formed between the base materials of the electrodes at both ends as in a general surface mount resistor type, it can be processed as a component that can be mounted in existing equipment.

  Next, FIGS. 1 to 4 show a dew condensation sensor 18 provided with a through-hole as the element cover 16. In FIG. 1, a top surface opening 19 is provided as a through hole on the top surface of the element cover 16, and in FIGS. 3 and 4, a top surface opening 19 is provided as a through hole on the top surface of the element cover 16. On the side surface, a side surface opening 20 is provided as a through hole. 3 and 4, both the top surface opening 19 and the side surface opening 20 are provided on the element cover 16, but depending on the mounting posture of the dew condensation sensor 18, only the top surface of the element cover 16 as shown in FIG. Alternatively, a through hole may be provided only on the side surface.

  The operation and operation of the dew sensor configured as described above will be described with reference to FIG.

  First, an operation in which the condensation sensor 18 can detect condensation in advance will be described. In FIG. 5, the ambient temperature t2 at which the dew condensation sensor 18 is installed is set to 10 ° C. for simplicity. At this time, since there is no cooling from the cooling source, the temperature t1 of the dew condensation detecting element 11 also becomes 10 ° C. indicated by a dotted line, and dew starts when the relative humidity rises to 100% RH (time T2). That is, the dew point temperature is 10 ° C. At the time T2, the dew sensor 18 determines that dew has formed, and changes the output voltage from V1 during drying to V2 as indicated by the dotted line.

  Next, when the wiring board 12 is cooled by a cooling source, for example, when the temperature t1 of the dew condensation detecting element 11 is set to 8 ° C. which is 2 ° C. lower than the ambient temperature 10 ° C., the temperature t1 of the dew detecting element 11 is as shown by a solid line. Become. Then, when the relative humidity rises and reaches 90% RH (time T1), dew condensation starts. That is, when the dew point temperature is 8 ° C. and the relative humidity is 90% RH, dew is formed. At the time T1, the dew condensation sensor 18 determines that dew has formed, and changes the output voltage from V1 during drying to V2 as indicated by the solid line.

  In summary, when the dew condensation sensor 18 is installed in an environment with an ambient temperature of 10 ° C. and the dew condensation detecting element 11 is cooled to 8 ° C., the dew condensation sensor 18 does not dew condensation even if the relative humidity is 90% RH. Judgment of condensation. That is, dew condensation can be detected at time T1 earlier than time T2 shown in FIG. In the description, the temperature of the dew condensation detecting element 11 is set to 8 ° C. for the determination at the relative humidity of 90% RH. However, in the case of a slightly higher humidity side, the cooling setting may be set higher than 8 ° C. In that case, on the contrary, a lower setting may be used.

  Next, a description will be given of an abnormal dew condensation state that occurs when dew condensation is detected in advance but the dew prevention control does not operate correctly. In this case, since the dew condensation detecting element 11 is cooled to a lower temperature than the surroundings, excessive dew water accumulates in the element cover 16. However, when the dew sensor 18 is mounted downward in the Z-axis direction (FIG. 3), the dew water is drained from the top surface opening 19 by natural fall and does not remain in the element cover 16. In the case of the Y-axis downward direction (FIG. 4), the water is drained from the side opening 20. Here, the size of the opening is set to a size that is greater than the force of gravity due to the own weight of the dew condensation water, than the force of the dew condensation water to stay in the element cover 16 due to surface tension. Further, the element cover 16 also has a role of preventing the dew condensation detecting element 11 from being damaged by bare hands touching or being hit by a tool, and is set to a size that does not cause a problem. As a result of experiments, it is preferable that the size of the opening is about 3 to 5 mm.

  Although the content of cooling the dew condensation detecting element 11 has been described, if there is a distribution difference in the surrounding environment in the application range of the main body side, if the dew condensation sensor 18 is installed in a portion having the highest humidity or a low temperature, the Since the portion starts dew condensation earlier in time, the dew condensation can be detected in advance without cooling.

  As described above, in the present embodiment, at least the dew condensation detecting element 11 provided on the wiring board 12 is provided, the element cover 16 for covering the dew condensation detecting element 11 is provided, and the dew condensation generated in the element cover 16 is formed. By providing a through-hole for water through the element cover 16, it is possible to prevent the dew sensor 18 from being damaged due to the contact of the dew detection element 11 with bare hands or tools during the transportation and conveyance of the dew sensor 18 and the mounting work on the main body side. Even if abnormal dew condensation continues for a long time and water drops accumulate in the element cover 16, the water droplets are drained from the through holes, so that abnormal control of the dew condensation continuation determination on the main body side can be avoided. Therefore, it is possible to prevent the reliability from being deteriorated.

  Further, by providing a plurality of top surface opening portions 19, side surface opening portions 20, and the like as the through holes, the dew water in the element cover 16 is more easily drained, so that the constraint on the mounting position of the dew sensor is reduced. That is, the degree of freedom of attachment is improved. Furthermore, the dew sensor 18 can be used in a highly reliable state.

  In addition, since the through-hole is provided in the vertical direction, the water droplets that are abnormally condensed in the element cover 16 work in the direction of falling from the through-hole by its own weight due to gravity, so that the drainage of water can be improved. As a result, the dew condensation can be detected in advance without erroneous detection, and the storage room can be maintained in a high humidity state.

  In addition, since the area of the through hole is such that the gravity due to its own weight is larger than the surface tension of the dew condensation water accumulated in the element cover 16, it is physically impossible for water to accumulate as water droplets in the element cover 16. Therefore, the reliability against abnormal dew condensation is further improved, and the application of the dew condensation sensor 16 to the main body can be easily performed.

  Although not described in detail, by performing hydrophilic treatment on the surface of the element cover 16, the probability that the dew condensation water becomes water droplets is reduced, and the dew condensation water flows on the surface and is discharged from the through holes, thereby further improving reliability. It becomes possible.

(Embodiment 2)
FIG. 6 is a longitudinal sectional view of a refrigerator using a dew condensation sensor on the back according to Embodiment 2 of the present invention, FIG. 7 is a longitudinal sectional view of a vegetable room of the refrigerator, and FIG. FIG. 9 is a longitudinal sectional view of the vegetable compartment of the refrigerator using the condensation sensor on the top surface according to the second embodiment, and FIG. 10 is an enlarged longitudinal sectional view of a main part of the vegetable compartment of the refrigerator.

  First, in FIGS. 6 to 8, the heat insulating box 101 of the refrigerator 100 includes an outer box 102 mainly using a steel plate, an inner box 103 molded of a resin such as ABS, and an outer box 102 and an inner box 103. It is made of a foamed heat insulating material such as hard urethane foam, which is filled and foamed in the space therebetween, insulated from the surroundings, and divided into a plurality of storage rooms.

  A refrigerating room 104 as a first storage room is provided at the uppermost portion. A switching room 105 as a fourth storage room and an ice making room 106 as a fifth storage room are arranged side by side below the refrigerating room 104. Are arranged side by side, a vegetable room 107 as a second storage room is provided below the switching room 105 and the ice making room 106, and a freezing room 108 as a third storage room is provided at the bottom. It has become.

  The temperature of the refrigerator compartment 104 is usually 1 ° C. to 5 ° C. with a temperature not freezing for refrigeration, and the temperature of the vegetable compartment 107 is 2 ° C. to 7 ° C. which is equal to or slightly higher than that of the refrigerator compartment 104. The freezer compartment 108 is set in a freezing temperature range, and is usually set at −22 ° C. to −15 ° C. for freezing and preservation. It may be set at a low temperature of ° C. The switching room 105 has a refrigerator temperature zone set at 1 ° C to 5 ° C, a vegetable temperature zone set at 2 ° C to 7 ° C, and a freezing temperature zone usually set at -22 ° C to -15 ° C. It is possible to switch from a refrigerated temperature zone to a frozen temperature zone to a preset temperature zone. The switching room 105 is a storage room provided with an independent door juxtaposed to the ice making room 106, and is often provided with a drawer type door.

  In the present embodiment, the switching room 105 is a storage room including the temperature range of refrigeration and freezing, but refrigeration is left to the refrigeration room 104, the vegetable room 107, and freezing is left to the freezing room 108, A storage room specialized in switching only the above-mentioned temperature zone between refrigeration and freezing may be used. Alternatively, a storage room fixed in a specific temperature zone may be used.

  The ice making room 106 forms ice with water sent from a water storage tank (not shown) in the refrigeration room 104 by an automatic ice making machine (not shown) provided in the upper part of the room, and an ice storage container ( (Not shown).

  The top surface of the heat-insulating box 101 has a step-shaped recess toward the rear of the refrigerator 100. The machine room 101a is formed in the step-shaped recess, the compressor 109, and a dryer for removing moisture. (Not shown) and the like are accommodated therein. That is, the machine room 101 a in which the compressor 109 is disposed is formed by cutting into the uppermost rear region in the refrigerator compartment 104.

  Note that, in the present embodiment, matters relating to the main part of the invention described below are as follows. A machine room is provided in the lowermost storage room rear region of the heat insulating box 101, which has been conventionally general, and the compressor 109 is provided there. It may be applied to the type of refrigerator to be arranged. Further, the refrigerator 100 having a so-called mid-freezer configuration in which the arrangement of the freezing compartment 108 and the vegetable compartment 107 is interchanged may be used.

  Next, a cooling room 110 for generating cool air is provided on the back of the vegetable room 107 and the freezing room 108, and a heat insulating property is provided between the vegetable room 107 and the cooling room 110 or between the freezing room 108 and the cooling room 110. , And a back-side partition wall 111 configured to be insulated from each room.

  A cooler 112 is provided in the cooling room 110, and cool air cooled by the cooler 112 by a forced convection method is cooled in the upper space of the cooler 112 in the refrigerator room 104, the switching room 105, the ice making room 106, and the vegetables. A cooling fan 113 for blowing air into the chamber 107 and the freezing chamber 108 is provided, and a radiant made of a glass tube for removing frost and ice adhering to the cooler 112 and its surroundings during cooling is provided in a lower space of the cooler 112. A heater 114 is provided, and a drain pan 115 for receiving defrost water generated at the time of defrosting and a drain tube 116 penetrating from the deepest portion to the outside of the refrigerator are provided at a lower portion thereof. 117 is configured.

  In the vegetable room 107, a lower storage container 119 mounted on a frame attached to the drawer door 118 of the vegetable room 107, and an upper storage container 120 mounted on the lower storage container 119 are arranged. With the drawer door 118 closed, a lid 122 for substantially sealing the upper storage container 120 is held by the first partition wall 123 and the inner box 103 provided above the vegetable compartment 107. . With the drawer door 118 closed, the left side, the right side, and the back side of the upper surface of the lid 122 and the upper storage container 120 are in close contact, and the front side of the upper surface is in close contact. Further, the boundary between the lower left and right sides of the back surface of the upper storage container 120 and the lower storage container 119 is filled with a gap so that moisture in the food storage unit does not escape to the extent that the upper storage container 120 does not come into contact during operation.

  Between the lid 122 and the first partition wall 123, an air passage for cool air discharged from the discharge port 124 for the vegetable compartment 107 formed in the back partition wall 111 is provided. A cooling member 200 penetrates and is buried in the rear partition wall 111 near the vegetable compartment 107, one end of which is exposed in the conveying air passage 141, and the other end is provided with a dew sensor 18.

  Further, a space is also provided between the lower storage container 119 and the second partition wall 125 below the lower storage container 119 to form a cool air passage. An inlet 126 for the vegetable compartment 107 for cooling the inside of the vegetable compartment 107 and returning the heat exchanged heat to the cooler 112 is provided at a lower portion of the rear partition wall 111 provided on the back side of the vegetable compartment 107. Have been.

  The back partition wall 111 is formed of a heat insulating material formed of styrene foam or the like for isolating the surface formed of a resin such as ABS from the conveying air passage 141 and the cooling chamber 110 and ensuring heat insulation.

  Next, the configuration near the condensation sensor 18 will be described in more detail. The cooling member 200, one end of which is exposed in the conveying air passage 141, penetrates through the heat-insulating back partition wall 111, and the dew condensation sensor 18 described in the first embodiment is thermally fixed to the other end. ing. Specifically, the cooling member 200 is fixed to the back surface side of the wiring board 12 on which the components of the dew condensation sensor 18 are not mounted, for example, via a heat-dissipating silicon sheet or a highly heat-conductive resin material that absorbs shock. It is even better if they are physically fixed with screws or the like. The cooling member 200 is preferably made of a material having an extremely high thermal conductivity, such as a metal such as aluminum or a molded product of a high thermal conductive resin. At this time, the mounting direction of the dew condensation sensor 18 is downward in the Y-axis shown in FIG. 4 of the first embodiment, and the side opening 20 is open vertically downward.

  In addition, a sensor insertion member 202 having a dimension R larger than the outer shape of the dew condensation sensor 18 is attached to a portion of the lower storage container 119 which is in contact with the dew condensation sensor 18, and when the drawer door 118 is closed, the dew condensation sensor 18 is closed. Is installed inside the lower storage container 119. If a rubber grommet or the like having a radial slit is used as the sensor insertion member 202, it is possible to reduce the impact with the dew condensation sensor 18 at the time of insertion and to secure airtightness after the insertion.

  Further, a humidity control mechanism 201 is mounted on the back side of the lower storage container 119 on the rear side, and the space is sealed or opened according to information from the dew sensor 18 in the vegetable compartment. The humidity control mechanism 201 includes a flap opening / closing by an electromagnet (an electromagnet on the main body side and a magnetic flap on the container side), an electric damper drive by non-contact power supply (primary side power supply to the main body side, secondary side power receiving and motor to the container side). By using the container-side insertion into the body-side flap mechanism, the drawer door 118 can be opened and closed without using a harness.

  The operation and operation of the refrigerator configured as described above will be described below.

  First, the operation of the refrigeration cycle will be described. A refrigeration cycle is operated by a signal from a control board (not shown) according to a set temperature in the refrigerator, and a cooling operation is performed. The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 109 is condensed and liquefied to some extent in a condenser (not shown), and is further provided on a side or back surface of the refrigerator 100 or a refrigerant pipe ( (Not shown) and condensed and liquefied while preventing dew condensation in the refrigerator 100, and reaches a capillary tube (not shown). Thereafter, in the capillary tube, the pressure is reduced while exchanging heat with a suction pipe (not shown) to the compressor 109 to be a low-temperature and low-pressure liquid refrigerant, which reaches the cooler 112.

  Here, the low-temperature and low-pressure liquid refrigerant exchanges heat with air in each storage room such as the conveying air passage 141 of the freezing room 108 that is conveyed by the operation of the cooling fan 113, and the refrigerant in the cooler 112 evaporates. At this time, cool air for cooling each storage room in the cooling room 110 is generated.

  The low-temperature cold air generated in the cooling room 110 is diverted from the cooling fan 113 to the refrigeration room 104, the switching room 105, the ice making room 106, the vegetable room 107, and the freezing room 108 by using an air passage or a damper 145. Cool to each target temperature zone.

  The refrigerating compartment 104 is cooled to a target temperature by adjusting the amount of cold air by a damper 145 by a temperature sensor (not shown) provided in the refrigerating compartment 104. In particular, the temperature of the vegetable compartment 107 is adjusted to 2 ° C. to 7 ° C. by ON / OFF operation of cold air distribution and heating means (not shown).

  After cooling the refrigerator compartment 104, the vegetable compartment 107 discharges to the vegetable compartment 107 from the discharge port 124 for the vegetable compartment 107 formed in the middle of the refrigerator compartment return air passage for circulating the air to the cooler 112. Then, it flows to the outer periphery of the upper storage container 120 or the lower storage container 119 to cool it indirectly, and then returns to the cooler 112 again through the suction port 126 for the vegetable compartment 107.

  In this way, the vegetable room 107 is set to the optimum temperature for the vegetables. On the contrary, since cooling has a dehumidifying effect, the evaporation of water from the vegetables is inevitably accelerated over time, and Since the weight is reduced, and especially the leafy vegetables are withered and the commercial value is degraded, the inside of the container is kept at a high humidity by making the lower storage container 119 and the upper storage container 120 substantially closed. However, if the hermetically sealed state is continued, the water may evaporate from the vegetables, and if the inside of the container is condensed and accumulates on the bottom surface, the vegetables may be rotten. For this purpose, in the present embodiment, the dew condensation sensor 18 and the humidity control mechanism 201 are used to appropriately control the humidity in the lower storage container 119 particularly containing many vegetables so that a high humidity state without dew condensation is maintained. ing.

  Next, an operation of detecting dew condensation in advance will be described. The cooling member 200, one end of which is exposed in the conveying air passage 141, is cooled by cool air and cools the back surface of the wiring board 12 of the condensation sensor 18 by heat conduction. When cooled, the dew condensation detecting element 11 in the dew sensor 18 is also cooled and becomes lower than the ambient temperature of the lower storage container 119. Accordingly, when the lower storage container 119 shifts to high humidity, the dew condensation detecting element 11 has a lower temperature and a lower dew point temperature than the inner wall of the container, so that dew condensation can be detected earlier (in advance) than the inner wall of the container. As a specific example, when the inside of the vegetable compartment 107 is set to 5 ° C., and the relative humidity of 90% RH is detected, the temperature of the dew condensation detecting element 11 may be set to 3 ° C. Structural hardware adjustment such as the volume of the cooling member 200, the exposed length in the conveying air path 141, the contact thermal conductivity between the cooling member 200 and the condensation sensor 18, and the cooling time of the cooling member 200 (the operating time of the cooling fan 113) The desired dew point temperature may be controlled by software soft adjustment such as detection timing of the dew sensor 18 from the start of cooling.

  Then, when dew condensation is detected in advance, the operation of the humidity control mechanism 201 is started, and the inside of the lower storage container 119 is opened by opening with an opening / closing flap or dehumidifying by an electrolytic dehumidifying element such as a solid polymer electrolyte membrane. Reduces humidity. Thereafter, when the dew condensation sensor 18 returns (dry), the operation is stopped and the inside of the container is returned to a substantially sealed structure to return to a high humidity state.

  Here, when the operation of the humidity control mechanism 201 is stopped or a large amount of vegetables are thrown, the dew condensation sensor 18 is cooled more than the inner wall of the container for the detection of dew condensation in particular. However, water droplets do not accumulate in the element cover 16 for a long time because the side opening 20 is provided vertically downward.

  The lower storage container 119 has been described above. Next, an embodiment in which the condensation sensor of the present invention is applied to the upper storage container 120 will be described with reference to FIGS.

  A switching room 105 or an ice making room 106 which is set at a lower temperature than the vegetable room 107 is installed above the vegetable room 107, and is divided by a first partition wall 123 having heat insulation. The first partition wall 123 has a partition wall concave portion 203, and the dew condensation sensor 18 described in the first embodiment is opened in the Z-axis downward direction shown in FIG. 3, that is, the top surface opening 19 is opened vertically downward, Thermally fixed. Specifically, it is fixed to the back surface side of the wiring board 12 on which the components of the dew condensation sensor 18 are not mounted by screws or the like via a heat conductive member 204. The heat conductive member 204 is preferably a heat-dissipating silicon sheet or a high heat conductive resin material that absorbs shock, and a metal such as aluminum can be used as long as insulation and safety can be ensured.

  Further, a humidity control member 205 is provided at a portion where the upper storage container 120 abuts on the first partition wall 123 to ensure the airtightness of the upper storage container 120, and the dew sensor 18 is arranged in this space. . As the humidity control member 205, a means having an electric opening / closing flap function is reliable but high cost, so that the outer periphery of the upper storage container 120 is covered with a flexible foam member and a gap with the first partition wall 123 is formed. It is also possible to respond by optimizing.

  The operation and operation in this configuration are the same as those in the case where the dew condensation sensor 18 is installed on the rear surface and applied to the lower storage container 119, and thus the description is omitted, and the case of abnormal dew condensation will be described.

  Since the dew condensation sensor 18 is installed in the partition wall recess 203 of the first partition wall 123, that is, in a portion where the thickness of the wall is small, the dew condensation sensor 18 is cooled more than the inner wall of the upper storage container 120 particularly for detecting dew condensation in advance. Therefore, a large amount of water droplets easily adhere to the inside of the element cover 16, but since the top surface opening 19 is provided vertically downward, water droplets do not accumulate in the element cover 16 for a long time.

  As described above, in the present embodiment, the opposite surface of the wiring board 12 on which the condensation detection element 11 of the condensation sensor 18 is mounted is brought into contact with the coldest part in the storage room of the refrigerator 100 in which the condensation sensor 18 is installed. In addition, since the through hole is formed in a vertical downward direction with respect to the space in the element cover 16, the drainage of water droplets from the inside of the element cover 16 at the time of abnormal condensation is improved. In cooperation with, it is possible to safely maintain a high humidity state up to the dew condensation limit, and to maintain freshness of vegetables.

  As described above, the dew condensation sensor according to the present invention can detect dew condensation in advance without abnormal water droplets accumulating in the element cover for protection of the dew detection element. It can be applied not only to food and vegetables but also to applications such as distribution and warehouse that require high-humidity storage, including foods other than vegetables.

DESCRIPTION OF SYMBOLS 11 Condensation detection element 12 Wiring board 13 Electronic component 14 Detection circuit part 15 External connection part 16 Element cover 17 Conductor pattern 18 Dew condensation sensor 19 Top opening (through hole)
20 Side opening (through hole)
DESCRIPTION OF SYMBOLS 100 Refrigerator 101 Insulated box 102 Outer box 103 Inner box 104 Refrigerator room 105 Switching room 106 Ice making room 107 Vegetable room (storage room)
108 Freezer room 109 Compressor 110 Cooling room 111 Back partition wall 112 Cooler 113 Cooling fan 114 Radiant heater 115 Drain pan 116 Drain tube 117 Evaporating dish 118 Drawer door 119 Lower storage container 120 Upper storage container 122 Lid 123 First partition Wall 124 Discharge port 125 Second partition wall 126 Suction port 141 Conveyance air path 200 Cooling member 201 Humidity control mechanism 202 Sensor insertion port member 203 Partition wall recess 204 Heat conduction member 205 Humidity control member

Claims (5)

At least having a dew detection element provided on the wiring board,
A dew condensation sensor comprising: an element cover for covering the dew detection element; and a through-hole in the element cover for passing dew water generated in the element cover. The condensation sensor according to claim 1, wherein a plurality of the through holes are provided. The condensation sensor according to claim 1, wherein the through-hole is provided in a vertical direction. The condensation sensor according to any one of claims 1 to 3, wherein the area of the through hole is such that gravity due to its own weight is larger than the surface tension of the condensation water accumulated in the element cover. A refrigerator comprising: the dew condensation sensor according to any one of claims 1 to 4; and a vegetable compartment, wherein the dew condensation sensor is provided in a coolest part of the vegetable compartment.

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