JP2002195971A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple structure which can manage to suppress vegetable spoilage stored at a vegetable room in a refrigerator. SOLUTION: The refrigerator is composed like this: a gas perception sensor 25 which detects the concentration change of the gas component arising from greengrocery such as vegetables and fruit in the vegetable room 12 is placed; a decision means for determining the degree of freshness of the greengrocery in the vegetable room 12 based on the electrical output of the gas perception sensor 25 is placed; a display means 27 inspected visually from outside of the refrigerator is connected to the output side of the decision means; the degree of freshness of the greengrocery in the vegetable room 12 is recognized by the display means 27. The management for keeping freshness of the greengrocery is always carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of storage and preservation of foods stored in a refrigerator, particularly, fruits and vegetables such as vegetables and fruits.

[0002]

2. Description of the Related Art Controlling the freshness of foods, such as fresh foods, is important at home regardless of the food manufacturers or the food service industry. However, the method of managing freshness at home is to calculate the number of days based on the expiration date specified by the food manufacturer, and to judge whether or not it has gone rot by the subjective sensory evaluation of each person such as gloss, color, aroma, etc. It is currently managed.

[0003] Against this background, a freshness management device has been proposed in view of a refrigerator for storing foods, and one such device is disclosed in Japanese Patent No. 2875174.

Hereinafter, the above-described conventional freshness management device will be described with reference to the drawings.

FIG. 13 is a functional block diagram of a conventional freshness management device. In FIG. 13, reference numeral 1 denotes a freshness management device, a storage room 2 for storing vegetables, a sensor 3 provided in the storage room 2 for detecting gas components and concentrations generated from the vegetables and converting them into electric signals, It comprises a freshness maintaining device 4 for recovering and maintaining the gas environment in the storage room 2, and a microprocessor 5 for outputting a control signal of the freshness maintaining device 4 by an electric signal from the sensor 3.

The operation of the freshness management device configured as described above will be described below.

[0007] When the user stores vegetables in the storage room 2, the vegetables become ethylene, hydrogen sulfide,
It generates sulfur compound gas such as methyl mercaptan, dimethyl sulfide and dimethyl disulfide and reducing gas. Such a gas combines with oxygen ions on the surface of the sensing sensor 3 to generate conduction electrons, which are input to the microprocessor 5 as an electronic signal, and a control signal is sent to the freshness maintaining device 4, and the freshness maintaining device 4 Is to maintain the freshness of the vegetables.

[0008]

However, in the above-mentioned conventional configuration, when the gas component generated from the vegetables stored in the storage room 2 and its concentration change, the freshness of the already stored vegetables deteriorates. Therefore, there is a disadvantage that the freshness maintaining device 4 cannot be operated before the freshness is deteriorated, and the effect cannot be sufficiently exhibited. In addition, even if the freshness maintaining device 4 is operated, if the vegetables themselves have already started the freshness deterioration reaction in the cells, the speed of the freshness deterioration reaction is slightly reduced by the action of the freshness maintenance device 4 but can be suppressed. It is not possible.

[0009] Further, changes in gas components and concentrations generated from vegetables are affected by factors unrelated to freshness, such as changes in storage amounts, such as differences in storage amounts of vegetables and purchases of vegetables. There is a disadvantage that the means of notifying the preservation state of the vegetables and consuming the target vegetables as soon as possible is superior.

The present invention solves the conventional problem. When the freshness of a vegetable decreases, a change in the concentration of a specific gas generated from the vegetable is detected by a sensor. It is an object of the present invention to provide a refrigerator for notifying by a display function of the refrigerator.

[0011]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention provides a judging means based on an electric output from a gas sensor which is provided in a vegetable room and detects a change in concentration of a complex gas component generated from fruits and vegetables. Has a display means for judging the storage state of the fruits and vegetables in the vegetable room and displaying the contents. Thereby, before the freshness of vegetables and fruits such as vegetables and fruits in the vegetable room decreases, the storage state can be confirmed on the display means, and the vegetables and fruits such as stored vegetables can be stored and managed without being rotten in the back of the vegetable room.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS By adopting the configuration according to claim 1 of the present invention as an embodiment, it is possible to confirm the storage state of stored fruits and vegetables in a vegetable room on a display means, and to store stored fruits and vegetables in the back of the vegetable room. Preservation management can be done without rot.

According to the fifth aspect of the present invention, the type and concentration of the composite gas can be easily detected.

According to the seventh aspect of the present invention, a single gas sensing sensor is provided, and a temperature control means for changing a heating temperature of a heater in the gas sensing sensor is provided. Can be detected at low cost and space can be saved.

According to the eighth aspect of the present invention, the power supply time for heating the heater in the gas sensor is intermittently controlled by the intermittent control means, so that the power consumption by the heater can be greatly reduced. it can.

According to the ninth aspect of the present invention, the effect of a sudden output change due to an external factor such as opening and closing of a door can be taken into consideration, and a more accurate determination can be made.

According to the tenth aspect of the present invention, the deterioration of the performance of the gas sensing sensor due to the high humidity in the vegetable compartment can be suppressed, and the determination of high reliability can be continuously performed.

According to the eleventh aspect of the present invention, the degradation hormone gas can be removed from ethylene, so that the deterioration of fruits and vegetables such as vegetables can be delayed, and long-term storage is possible. .

The present invention is fundamentally different from the technique disclosed in Japanese Patent No. 2875174, which discloses the rot state of vegetables by a warning sound, and the present invention is a technique for rotting fruits and vegetables stored and stored in a vegetable room. It is possible to inform the user of the freshness state of the fruits and vegetables by an externally visible display means without causing the user to see.

Therefore, in the refrigerator according to the present invention, since the freshness state of the fruits and vegetables can be known by looking at the display on the display means, it is possible to constantly maintain the freshness. Since the display means described in the claims of the present invention means the above, a second aspect is provided.
A display means capable of predicting a change in freshness as described is preferable. It is preferable from the viewpoint of maintaining and controlling freshness that a change in gas concentration including a difference in gas components such as ethylene, aldehyde, alcohol, sulfur, and ammonia is included.

[0021]

(Embodiment 1) FIG. 1 is a sectional view of a refrigerator according to Embodiment 1 of the present invention. FIG. 2 is a functional block diagram showing a main part of the refrigerator of the embodiment. FIG. 3 is a characteristic diagram showing the degree of vegetable deterioration and the concentration of generated gas in the vegetable room of the embodiment.

In FIG. 1, reference numeral 6 denotes a refrigerator main body, and an upper storage section 8 is formed at an upper portion and a lower storage section 9 is formed at a lower portion by a heat insulating partition wall 7. 10 is the upper storage compartment 8
It is a partition plate which partitions the inside up and down, and forms a refrigerator compartment 11 at the upper part and a vegetable compartment 12 for storing vegetables, fruits and the like at the lower part. 13 is a cooling plate dedicated to the vegetable room, and the upper storage section 8
Is completely divided into upper and lower parts to cut off the flow of cool air. 1
Reference numeral 4 denotes a hinged door attached to the front opening of the refrigerator compartment 11, and reference numeral 15 denotes a drawer door attached to the front opening of the vegetable compartment 12 to pull out the storage container 16 integrally.

Reference numeral 17 denotes a compressor of a refrigeration cycle provided at the lower rear of the refrigerator main body 6, reference numeral 18 denotes a first cooler provided in the upper storage section 8, and reference numeral 19 denotes a forced cool air generated by the first cooler 18. A first blower that ventilates, 20 is a second cooler provided in the lower storage compartment 9, and 21 is a second blower that forcibly ventilates the cool air generated in the second cooler 20.

Reference numeral 22 denotes an air supply port for the vegetable compartment 12 formed in front of the partition plate 10, reference numeral 23 denotes an exhaust port from the vegetable compartment 12 formed behind the partition plate 10, and reference numeral 24 denotes a vegetable compartment 12.
The inside is a ventilation path from the air supply port 21 to the exhaust port 22. Reference numeral 25 denotes a gas sensing sensor disposed in the ventilation path 24 in the upper part of the vegetable compartment 12.

In FIG. 2, reference numeral 26 denotes a judging means comprising a microcomputer, and a gas sensing sensor which changes the electric resistance on the input side according to the concentration of a complex gas such as ethylene, aldehyde, alcohol, sulfur or ammonia. An electric signal is input from the input unit 25, and a display unit 27 is connected to the output side.

The display means 27 is composed of a liquid crystal panel or the like and is attached to the surface of the door 14 of the refrigerator compartment to inform the user that the storage condition of the vegetables in the vegetable compartment 12 has been lowered.

With respect to the refrigerator configured as described above,
The operation will be described below with reference to the characteristic diagram shown in FIG.

First, when fresh vegetables are stored in the vegetable compartment 12 at the time point a, various gases are present at low concentrations.
Ethylene is generated immediately, peaks near point b, and decreases thereafter. Thereafter, as time elapses, the gases other than the ethylene-based gas begin to increase, and the aldehyde-based gas peaks near point c, and thereafter gradually decreases.

When the deterioration of vegetables starts after the time point c, the amount of alcohol and sulfur generated increases. Further, at the time point d, the generation of ammonia starts and the vegetables are completely degraded, and rot with the rapid increase of ammonia.

The present inventors have experimentally found the above contents.

Therefore, in order to determine the state of deterioration of vegetables, the magnitude of the electric signal corresponding to each of the ethylene, aldehyde, alcohol, sulfur, and ammonia gases detected by the gas sensor 25 is used. What is necessary is just to judge. Specifically, the magnitude of the electric signal from each gas is A,
Assuming B, C, D, and E, the degree of deterioration K can be expressed by the following (Equation 1).

[0032]

(Equation 1)

Therefore, as the value of the degree of deterioration K increases, the deterioration of the vegetables progresses. If the value exceeds a value set in advance by the judging means 26, it can be determined that the freshness has deteriorated. Therefore, the display information is sent from the determination means 26 to the display means 27, and the user is visually recognized that the storage state of the vegetables in the vegetable room 12 has been reduced by, for example, an image diagram or animation on the liquid crystal panel.

The constants α, β, γ, δ, and ε of (Equation 1)
If is set in detail according to the type of vegetables as shown in the following (Table 1), the degree of deterioration can be determined more accurately.

[0035]

[Table 1]

As described above, according to the present embodiment, as in the conventional example, the concentration of sulfur compound gas, reducing gas, etc., which is generated as the freshness deteriorates from the storage in the vegetable compartment itself is detected. Unlike the one that drives the freshness maintenance device, when the freshness of the vegetables decreases, the sensor detects the change in the specific gas concentration generated from the vegetables and displays the refrigerator in advance before the damage of the vegetables progresses By notifying with the function, the user can manage the foodstuffs economically for the user.

(Embodiment 2) FIG. 4 is a functional block diagram showing a main part of a refrigerator according to Embodiment 2 of the present invention. FIG.
FIG. 2 is a perspective view of the semiconductor gas sensor of the embodiment.

In FIG. 4, reference numerals 28 to 32 denote ethylene, ammonia, alcohol, aldehyde, etc. on the input side.
Semiconductor-type gas sensors A to E having selectivity to a composite gas such as a sulfur-based gas.
5. Then, the electric resistance changes according to the selected gas concentration, and the result is input to the determination means 26 as an electric signal.

In FIG. 5, reference numeral 33 denotes an insulating substrate such as alumina or mullite; 34, an electrode made of a metal such as gold, silver, or platinum; and 35, a sensing film mainly composed of a metal oxide such as tin oxide. And an electrode 34 facing the upper surface of the insulating substrate 33.
And a sensing film 35 is formed between the electrodes 34. Reference numeral 36 denotes a heater electrode made of a metal such as gold, silver, or platinum. Reference numeral 37 denotes a heater such as ruthenium oxide. A heater electrode 36 is provided facing the lower surface of the insulating substrate 33, and a heater 37 is formed between the heater electrodes 36. .

The sensing film 35 has a characteristic that oxygen in the air adsorbed on the surface is reduced by the reducing gas, and the resistance value changes according to the gas concentration. In addition, Pd, P
Gas selectivity can be imparted by selectively supporting metals such as t, Rh, and the like.

As described above, according to the present embodiment, unlike the one in which the generated gas is sampled and the concentration is detected by a measuring device such as gas chromatography which is difficult to install in a refrigerator, the sensor can be easily installed. Can be.

(Embodiment 3) FIG. 6 is a functional block diagram showing a main part of a refrigerator according to Embodiment 3 of the present invention. FIG.
FIG. 3 is a characteristic diagram showing a relationship between a heater heat generation temperature and a sensor sensitivity of the semiconductor gas sensor of the embodiment.

The temperature control means 38 shown in FIG. 6 changes the temperature of the heater of the semiconductor gas sensor.
As shown in FIG. 7, the semiconductor gas sensor can have gas selectivity by changing the heater heat generation temperature, that is, the gas reaction activation temperature of the sensing film. TA-T
By applying the temperature of E to the sensitive film in order at regular time intervals, a single sensor can detect a plurality of types of gases.

(Embodiment 4) FIG. 8 is a functional block diagram of a refrigerator according to Embodiment 4 of the present invention. FIG. 9 is a timing chart showing the relationship between the energized state of the heater and the temperature in the semiconductor gas sensor of the embodiment.

The intermittent control means 39 of FIG. 8 is configured to intermittently energize the heater of the semiconductor gas sensor. As shown in FIG.
After (time until the heater temperature reaches a predetermined temperature and the gas reaction activation temperature of the sensing film becomes stable), the gas concentration is measured at the P gas detection point. After the end of the measurement time, the power is cut off, and the total time tb is made the energization time. By performing gas sensing at the minimum necessary sampling period ta, low power consumption of tb / ta can be achieved as compared with continuous energization.

(Embodiment 5) FIG. 10 shows Embodiment 5 of the present invention.
FIG. 2 is a functional block diagram showing a main part of the refrigerator according to the first embodiment. FIG.
The storage means 40 of zero stores an electrical output before the heater of the semiconductor gas sensor is cut off, that is, a gas concentration. The detected gas concentration is compared with the previous measurement value stored in the storage means 40, and if there is a difference larger than a preset value, a sudden change due to external factors such as opening and closing of the door and taking in and out of vegetables, etc. Judge that there was.

Therefore, the value of the gas concentration sensed in that case is discarded, and the next measurement value is compared with the previous measurement value in the same manner, whereby highly reliable sensing can be performed.

(Embodiment 6) FIG. 11 shows Embodiment 6 of the present invention.
FIG. 2 is a functional block diagram showing a main part of the refrigerator according to the first embodiment. FIG.
1 is a configuration in which the heater temperature of the semiconductor gas sensor is set higher than the normally used gas reaction activation temperature by the regeneration temperature control means 41. If a gas sensing sensor is used for a long period of time, moisture adheres to the surface of the sensing film of the sensor in the form of hydroxyl groups due to the influence of humidity, and the deposition causes a deterioration in performance. Therefore, at the point where gas sensing is not performed, deterioration can be suppressed by raising the heater temperature for a certain period of time to a temperature at which hydroxyl groups are decomposed and removed, specifically about 400 ° C. to 450 ° C.

(Embodiment 7) FIG. 12 shows Embodiment 7 of the present invention.
FIG. The basic configuration is the same as that of FIG. 1 of the first embodiment. A third blower 42 is provided in the vegetable compartment 12, and the surface of the fan of the third blower 42 is coated with an ethylene gas adsorbing substance. The gas sensing sensor 25 detects the concentration of ethylene gas, which is a deteriorating hormone gas, in the vegetable compartment, and when the concentration exceeds a predetermined value, operates the third blower 42 to adsorb the ethylene gas by rotation of the fan. And lower the concentration in the vegetable room. Thereafter, when the concentration becomes equal to or lower than the certain concentration, the third blower 42 is stopped.

By repeating the above operation, the speed of deterioration of vegetables can be delayed, and the storage period can be extended. Examples of the ethylene-adsorbing substance include activated carbon, zeolite, silica, alumina, and the like, and palladium, bromine, platinum, and the like can be added to these substances to form an adsorbing decomposition substance.

[0051]

As described above, according to the first and second aspects of the present invention, the refrigerator is provided with display means which can be viewed externally, and the state of the fruits and vegetables stored and stored in the vegetable room can be known by the display means. Since it is possible, the user can manage the freshness before the freshness deterioration remarkably progresses, which is convenient.

According to the third, fourth, fifth, sixth and seventh aspects of the present invention, the gas sensing sensor and the determination means which can achieve the object of the present invention can be easily implemented.

According to the eighth aspect of the invention, the power consumption by the heater can be greatly reduced.

According to the ninth aspect, the door can be opened and closed,
A change in the output of the gas sensing sensor due to an external factor such as putting in and taking out fruits and vegetables such as vegetables can be omitted to make a highly accurate judgment.

According to the tenth aspect of the present invention, it is possible to recover the performance deterioration of the gas sensor and continue the determination with high reliability.

According to the eleventh aspect of the present invention, the ethylene gas is removed, and it is possible to prevent the ethylene gas from accelerating the freshness deterioration of the fruits and vegetables.

[Brief description of the drawings]

FIG. 1 is a sectional view of a refrigerator according to a first embodiment of the present invention.

FIG. 2 is a functional block diagram showing a main part of the refrigerator of the embodiment.

FIG. 3 is a characteristic diagram showing the degree of deterioration of vegetables and the concentration of generated gas in the vegetable room of the refrigerator of the embodiment.

FIG. 4 is a functional block diagram illustrating a main part of a refrigerator according to a second embodiment of the present invention.

FIG. 5 is a perspective view of the semiconductor gas sensor of the embodiment.

FIG. 6 is a functional block diagram illustrating a main part of a refrigerator according to a third embodiment of the present invention.

FIG. 7 is a characteristic diagram showing a relationship between a heater heat generation temperature and a sensor sensitivity of the semiconductor gas sensor of the embodiment.

FIG. 8 is a functional block diagram illustrating a main part of a refrigerator according to a fourth embodiment of the present invention.

FIG. 9 is a timing chart showing the relationship between the energized state of the heater and the temperature in the semiconductor gas sensor of the embodiment.

FIG. 10 is a functional block diagram illustrating a main part of a refrigerator according to a fifth embodiment of the present invention.

FIG. 11 is a functional block diagram illustrating a main part of a refrigerator according to a sixth embodiment of the present invention.

FIG. 12 is a sectional view of a refrigerator according to a seventh embodiment of the present invention.

FIG. 13 is a functional block diagram of a conventional freshness management device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Vegetable room 25 Gas sensor 26 Judgment means 27 Display means 35 Sensing film 37 Heater 38 Temperature control means 39 Intermittent control means 40 Storage means 41 Regeneration temperature control means 42 Third blower

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01N 27/00 G01N 27/00 L 33/02 33/02 (72) Inventor Tsuyoshi Ogino Higashiosaka-shi, Osaka Matsushita Refrigerating Machinery Co., Ltd. 4-5-2, Takaidahondori (72) Inventor Yoshikatsu Inoue 4-5-2, Takaidahondori, Higashiosaka-shi, Osaka Prefecture F-term in Matsushita Refrigerating Machinery Co., Ltd. 2G046 AA04 AA10 AA14 AA18 AA23 AA24 AA25 BA01 BB02 BC05 BE03 BG05 BH01 DB05 DC14 DC16 DC17 DC18 EB06 FB02 FE00 FE02 FE29 FE31 FE34 FE39 2G060 AA01 AB01 AB07 AB11 AB15 AB20 AB21 AB22 AE19 AF07 BA01 BB09 BC02 HB06 HC02 ABA HC15 ABA LA01 LA18 MA00 NA19 NA21 PA01 PA02 PA04

Claims (11)

[Claims] 1. A vegetable compartment for storing and storing vegetables and fruits such as fruits and vegetables, a gas sensor provided in the vegetable compartment and detecting a change in concentration of a gas component generated from the stored fruits and vegetables in the vegetable compartment. Determining means for determining a storage state of the stored fruits and vegetables in the vegetable room based on an electrical output of the gas sensing sensor; and display means for displaying a storage state of the stored fruits and vegetables in the vegetable room based on a signal from the determination means. A refrigerator characterized by: 2. The display of the display means indicates a change in concentration of a gas component generated from stored fruits and vegetables in a vegetable room, and includes information for predicting a degree of change in concentration or freshness. The refrigerator according to claim 1. 3. The method according to claim 1, wherein the determination by the determination means is based on a magnitude of an electric signal corresponding to gas generated from the stored fruits and vegetables in the vegetable room detected by the gas detection sensor. The refrigerator as described. 4. A gas detecting sensor comprising a microcomputer, wherein the input side of said microcomputer changes the electrical resistance according to the concentration of each of ethylene, aldehyde, alcohol, sulfur, and ammonia gases. The refrigerator according to any one of claims 1 to 3, wherein an electric signal is input to the refrigerator, and a display unit is connected to an output side. 5. The gas sensor according to claim 1, wherein the gas sensor comprises a plurality of semiconductor gas sensors, and each of the electrical outputs is sequentially input to the determination means.
The refrigerator according to any one of claims 3 and 4. 6. A plurality of semiconductor gas sensors, as a gas sensor for sensing ethylene gas, a pair of electrodes made of a metal such as gold, silver, and platinum provided on an insulating substrate; The refrigerator according to claim 5, further comprising a sensing film mainly composed of a metal oxide, and an ethylene gas sensing sensor including another electrode provided on the sensing film. 7. The gas sensing sensor includes one semiconductor gas sensor, and includes temperature control means for changing a heating temperature of the heater in the semiconductor gas sensor. And sensing different types of gas components.
The refrigerator according to any one of the above. 8. A refrigerator according to claim 1, further comprising intermittent control means for intermittently controlling an energizing time for causing a heater in the gas sensing sensor to generate heat. . 9. A storage means for storing an electrical output of a gas sensor before a power failure is provided, wherein an actually detected electrical output is significantly different from an electrical output stored in the storage means. 9. The refrigerator according to claim 8, wherein, in the case, it is determined that the electric output is changed based on opening / closing of the door or taking in and out of the fruits and vegetables in the vegetable room, and the value of the detected electric output is discarded. 10. The apparatus according to claim 5, further comprising a regeneration temperature control means for removing hydroxyl groups attached to the surface of the gas sensor by keeping the temperature higher than the normal temperature of the gas sensor for a certain period of time. A refrigerator according to claim 1. 11. The vegetable room is provided with a blower having a gas-adsorbed substance applied to its surface, and the blower is driven based on an electric signal from a gas sensor to remove ethylene gas as a deteriorating hormone gas. Claims 1 to 10
The refrigerator according to any one of the above.