JP2017026234A - Heat insulation device and food carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulation device capable of improving a cooling speed in a first heat insulation chamber and a second heat insulation chamber in a total cooling mode.SOLUTION: A heat insulation device includes at least one first heat insulation chamber (4) which can be used by switching to one of a heat storage chamber and a cold storage chamber, and at least one second heat insulation chamber (5) which can be used as the cold storage chamber, and the heat insulation device has a re-heating function. It also includes: a cold air supply device (6) for supplying cold air to the first and second heat insulation chambers (4, 5) when the first heat insulation chamber (4) is used as the cold storage chamber; and a cold air circulation device (7) for returning the cold air supplied to the first heat insulation chamber (4) to the cold air supply device (6).SELECTED DRAWING: Figure 6

Description

  The present invention is a so-called cook chill type heat retaining device that pre-heats food that has been cooked, rapidly cooled, and refrigerated (chilled), then placed on a tray, refrigerated (chilled) and reheated when necessary, And a food carrier equipped with the heat retaining device.

  In facilities that require a large amount of catering at once, such as hospitals, health care facilities for the elderly, hotels, and schools, for example, a thermal insulation device described in Patent Document 1 (JP 2009-236382 A) is provided. It is used.

  The heat retaining device of Patent Literature 1 includes a first heat retaining chamber that can be used by switching between a warm storage and a refrigerator, and a second heat retaining chamber that can be used as a refrigerator. According to this heat retaining device, for example, rapidly cooked food that has been cooked and needs to be reheated is placed on the first heat storage side of the tray, and food that does not require reheating is on the second heat storage side. After the tray is inserted and stored across the first and second warmer storage sides, the first warmer and the second warmer are both functioned as a refrigerator. Can be stored refrigerated. Also, before serving meals, use only the 1st heat storage as a reheating storage (function) to reheat the food, and then use it as a storage to provide a suitable temperature meal Can do.

JP 2009-236382 A

  In the heat retaining device of Patent Document 1, the first heat retaining chamber and the second heat retaining chamber are connected by a duct, and a valve is provided in the duct. With the valve closed in the duct, hot air is supplied to the first heat storage to use the first heat storage as a heat storage, and cold air is supplied to the second heat storage to change the second heat storage. It is intended to be used as a refrigerator. Hereinafter, the case where the first heat storage is used as the heat storage and the second heat storage is used as the refrigerator is referred to as “normal mode”.

  In addition, by supplying cold air to the second heat insulation box with the valve opened in the duct, cold air is also supplied to the first heat insulation box through the duct, and both the first heat insulation box and the second heat insulation box are refrigerators. To use as. Hereinafter, the case where both the first heat storage and the second heat storage are used as a refrigerator is referred to as a “fully cooled mode”.

  In the full cooling mode, it is required to quickly cool the inside of the first heat storage and the second heat storage as a refrigerator, which have been used as a heat storage, to about 3 ° C. In particular, if there is not enough time in the cycle of serving, refrigeration, reheating, laying, downside, and cleaning, cook in the first warmer that has been operating in normal mode and become hot for the next meal. In order to arrange and cool the rapidly cooled food, it is required to improve the cooling rate in the first and second heat insulation chambers in the whole cooling mode. From this point of view, there is room for improvement in the heat insulating device disclosed in Patent Document 1.

  Accordingly, an object of the present invention is to solve the above-described problem, and includes a heat retaining device capable of improving the cooling rate in the first heat retaining chamber and the second heat retaining chamber in the total cooling mode, and the heat retaining device. It is to provide a food transport vehicle (including a distribution vehicle).

In order to achieve the above object, the present invention is configured as follows.
According to the present invention, a heat retaining function having a reheating function including at least one first heat retaining container that can be used by switching to either a warm container or a refrigerator and at least one second heat retaining container that can be used as a refrigerator. A device,
When using the first heat storage as a refrigerator, a cold air supply device that supplies cold air to the first heat storage and the second heat storage;
A cold air circulation device that returns the cold air supplied to the first heat insulation chamber to the cold air supply device;
A thermal insulation device is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling rate in the 1st heat retention box in a all-cooling mode and a 2nd heat retention box can be improved.

It is a perspective view of a food conveyance vehicle provided with the heat retention apparatus which concerns on 1st Embodiment of this invention. It is a top view of the food conveyance vehicle of FIG. It is A1-A1 sectional view taken on the line of the food transport vehicle of FIG. 1, and is a diagram showing the flow of hot air and cold air in a normal mode. FIG. 2 is a cross-sectional view taken along line A2-A2 of the food transport vehicle in FIG. 1 and showing the flow of hot air and cold air in a normal mode. It is A3-A3 sectional view of the food conveyance vehicle of FIG. 1, Comprising: It is a figure which shows the flow of the hot air and cold air in normal mode. It is A1-A1 sectional view taken on the line of the food conveyance vehicle of FIG. 1, Comprising: It is a figure which shows the flow of the cold wind in all cooling mode. FIG. 2 is a cross-sectional view taken along the line A2-A2 of the food transport vehicle of FIG. 1 and showing a flow of cold air in a full cooling mode. It is A3-A3 sectional view of the food conveyance vehicle of FIG. 1, Comprising: It is a figure which shows the flow of the cold wind in all-cooling mode. It is a perspective view of a 1st chamber. It is a perspective view of a 2nd chamber. It is an expanded sectional view showing the state where the 1st valve was attached to the 1st duct. It is a front view of a frame. It is a side view of a frame. It is a perspective view of a rotation board. It is a perspective view which shows the modification of a rotation board. It is a perspective view of a food conveyance vehicle provided with the heat retention apparatus which concerns on 2nd Embodiment of this invention. It is a top view of the food conveyance vehicle of FIG. It is B1-B1 sectional view taken on the line of FIG. It is a perspective view of the heat retention apparatus which concerns on 3rd Embodiment of this invention. It is a top view of the heat retention apparatus of FIG. It is the C1-C1 sectional view taken on the line of FIG. It is the C2-C2 sectional view taken on the line of FIG. It is the C3-C3 sectional view taken on the line of FIG.

(Knowledge that became the basis of the present invention)
As a result of intensive studies to improve the cooling rate in the first and second heat insulation chambers in the cooling mode, the present inventors have obtained the following knowledge.

  In the conventional heat retaining device, cold air is supplied to the second heat insulating chamber through the duct while supplying the cold air to the second heat insulating chamber with the valve opened in the duct. Usually, since the partition is provided between the 1st heat storage and the 2nd heat storage, the flow of the cold wind between the 1st heat storage and the 2nd heat storage is suppressed. For this reason, the cold air supplied to the 1st heat insulation is discharged | emitted through the some path | route and clearance gap provided in the 1st heat insulation, such as the path | route where a hot air is supplied.

  The present inventors forcibly return the cold air supplied to the first heat insulation chamber to the cold air supply device through a path different from the supply path, and circulate the cold air, so that the first heat insulation chamber in the full cooling mode is used. And it discovered that the cooling rate in a 2nd heat retention box could be improved significantly. The present inventors have reached the following invention based on this novel finding.

According to the first aspect of the present invention, it is possible to switch to either a warm storage or a refrigerator, and at least one first warm storage that can be used, and at least one second warm storage that can be used as a refrigerator. A heat retaining device having a heating function,
When using the first heat storage as a refrigerator, a cold air supply device that supplies cold air to the first heat storage and the second heat storage;
A cold air circulation device that returns the cold air supplied to the first heat insulation chamber to the cold air supply device;
A thermal insulation device is provided.

According to a second aspect of the present invention, the cold air circulation device is
A first duct communicating the first heat storage and the cold air supply device;
A first fan that blows cool air supplied to the first heat insulation into the first duct;
The first duct is provided in the first duct and closes the inside of the first duct when the first heat storage is used as a heat storage, while the first duct is used when the first heat storage is used as a refrigerator. A first valve that opens to allow cold air to flow therein;
When the valve closes the first duct, the cool air supplied into the first heat insulation box is blown to the cool air supply device, while when the first valve opens the first duct, the first duct is opened. A second fan for blowing the cold air that has passed through the first valve together with the cold air supplied into the heat insulation chamber to the cold air supply device;
A heat retention device according to the first aspect is provided.

  According to a third aspect of the present invention, the first valve is configured to open the inside of the first duct by the wind pressure of the cold air when the cold air flows through the first duct. The thermal insulation apparatus as described in 1. is provided.

  According to a fourth aspect of the present invention, the first valve is configured to close the inside of the first duct by its own weight when cold air does not flow into the first duct. The thermal insulation apparatus as described in 1. is provided.

  According to the fifth aspect of the present invention, the first valve is pivotally supported at its upper part so as to be pivotable, and cool air that flows from the first heat insulation box to the cold air supply device when the inside of the first duct is closed. The heat retention device according to any one of the second to fourth aspects, which is provided so as to be inclined downward from the windward side toward the leeward side.

According to a sixth aspect of the present invention, the first valve is
An annular frame having an outer peripheral portion fitted into a groove provided on the inner peripheral surface of the first duct;
A rotating plate pivotally supported on the upper part and covering the opening of the annular frame so as to be openable and closable from above;
A heat retaining device according to the fifth aspect is provided.

According to the seventh aspect of the present invention, the heat retaining device further includes a hot air supply device that supplies hot air to the first heat retaining chamber when the first heat retaining chamber is used as a warm storage.
The hot air supply device is
A hot air generating device for generating hot air;
A first chamber that houses the hot air generator and communicates with the first warmer;
A second duct communicating the first chamber and the first heat storage;
A third fan for blowing the hot air supplied to the first heat storage into the first chamber;
With
The cold air supply device is
A cold air generator for generating cold air;
A second chamber that houses the cold air generation device and communicates with the second heat storage;
A third duct communicating the first chamber and the second chamber;
A fourth fan for blowing cold air generated by the cold air generation device to the first chamber;
The third duct is provided in the third duct and closes the inside of the third duct when the first heat insulation is used as a heat storage, while the third duct is used when the first heat insulation is used as a refrigerator. A second valve that opens to allow cold air to flow therein;
A heat retention device according to any one of the second to sixth aspects is provided.

  According to an eighth aspect of the present invention, the second fan is driven when the first heat storage is used in either the heat storage or the refrigerator, and the first fan, the third fan, And the heat retention apparatus as described in a 7th aspect with a wind force smaller than the said 4th fan is provided.

  According to a ninth aspect of the present invention, there is provided the heat retaining device according to the seventh or eighth aspect, wherein the second fan is provided in the second chamber.

  According to a tenth aspect of the present invention, the second valve is configured to open the inside of the third duct by the wind pressure of the cold air when the cold air flows through the third duct. The heat retention apparatus as described in any one of 9 aspects is provided.

  According to an eleventh aspect of the present invention, in the seventh to tenth aspects, the second valve is configured to close the inside of the third duct by its own weight when cold air does not flow in the third duct. The heat retention apparatus as described in any one of these is provided.

  According to the twelfth aspect of the present invention, the second valve is pivotally supported at the upper part thereof, and when the inside of the third duct is closed, the cold air flowing from the second chamber to the first chamber is blocked. The heat retaining device according to any one of the seventh to eleventh aspects, which is provided so as to be inclined downward from the windward side toward the leeward side.

According to a thirteenth aspect of the present invention, the second valve is
An annular frame having an outer peripheral portion fitted into a groove provided on the inner peripheral surface of the third duct;
A rotating plate pivotally supported on the upper part and covering the opening of the annular frame so as to be openable and closable from above;
A heat retention device according to the twelfth aspect is provided.

  According to a fourteenth aspect of the present invention, there is provided a food transport vehicle comprising the heat retaining device according to any one of the first to thirteenth aspects.

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

<< First Embodiment >>
A heat retaining device according to a first embodiment of the present invention and a food transport vehicle including the heat retaining device will be described. FIG. 1 is a perspective view of a food transport vehicle including a heat retaining device according to the first embodiment. FIG. 2 is a top view of the food transport vehicle. 3 and 6 are cross-sectional views taken along line A1-A1 of FIG. 4 and 7 are cross-sectional views taken along line A2-A2 of FIG. 5 and 8 are cross-sectional views taken along line A3-A3. 3 to 5 show the flow of hot air and cold air in the normal mode, and FIGS. 6 to 8 show the flow of cold air in the full cooling mode.

  As shown in FIG. 1, the food transport vehicle 1 according to the first embodiment includes a moving device (cart) 2 and a heat retaining device 3 provided on the moving device 2.

  The moving device 2 can move the heat retaining device 3. For example, the moving device 2 may be an electric type (including a power assist type) or a hand-push type.

  As shown in FIGS. 2 to 8, the heat retaining device 3 includes a first heat retaining chamber 4 that can be used by switching between a warm storage and a refrigerator, and a second heat retaining chamber 5 that can be used as a refrigerator. This is a heat retaining device having a reheating function. The 1st heat storage 4 and the 2nd heat storage 5 are formed in the partition unit 3C comprised so that attachment or detachment was possible, and can be accommodated in the heat insulation space 32 by the caster 13. FIG. When the partition unit 3C is stored in the heat insulation space 32, the projection 10 on the top surface of the partition unit 3C is sandwiched from both sides by the sealing member 11 installed on the heat insulation space 32 side, and the first heat insulation The space on the cabinet 4 side and the space on the second heat insulation cabinet 5 side are thermally insulated. In addition, the sealing member 12 is in contact with the bottom surface of the partition unit 3C, and the space on the first heat insulation chamber 4 side and the space on the second heat insulation chamber 5 side are thermally insulated. Moreover, the 1st heat storage 4 and the 2nd heat storage 5 are divided by the partition 9 in order to make it difficult to receive the influence of the other heat | fever, respectively. In addition, the partition 9 is a structure (FIG. 5, partition bar 43) as described in Unexamined-Japanese-Patent No. 2003-299524, for example. 2 to 8, the partition unit 3 </ b> C having the detachable first and second heat insulation chambers 4 and 5 has been described. May be. In this case as well, the first heat storage 4 and the second heat storage 5 are partitioned by the partition 9.

  Here, the “warm storage” refers to a food storage having a function capable of maintaining the internal temperature in a certain range. The “warm storage” refers to one that maintains the internal temperature in a temperature range higher than room temperature (for example, 20 ° C.). “Refrigerator” refers to one that maintains the internal temperature in a temperature range lower than room temperature. In addition, when using the 1st heat storage 4 as a heat storage, the temperature in the 1st heat storage 4 at the time of reheating is set, for example to 110-120 degreeC, and the temperature in the 1st heat storage 4 at the time of heat insulation Is set to 70 to 75 ° C., for example. Moreover, when using the 1st heat storage 4 and the 2nd heat storage 5 as a refrigerator, the temperature in the 1st heat storage 4 and the 2nd heat storage 5 is set to 5-10 degreeC, for example.

  As shown in FIGS. 3 to 8, the first heat insulation 4 is configured to be able to be stored across the second heat insulation 5 by inserting a plurality of trays 41 on which food is placed into the partition 9. The first heat insulating chamber 4 is provided with a vent hole (not shown) for taking in hot air and cold air. Similarly, the second heat storage 5 is configured to be able to store the plurality of trays 41 on which food is placed across the first heat storage 4. The second heat storage 5 is provided with a vent hole (not shown) for taking in cold air. The tray 41 has a structure (FIG. 11, tray 31) as described in, for example, Japanese Patent Application Laid-Open No. 2003-299524.

  In addition, as shown in FIGS. 2 to 8, the heat retaining device 3 includes a cold air supply device 6 that supplies cold air to the first heat retaining chamber 4 and the second heat retaining chamber 5, and cold air supplied to the first heat retaining chamber 4. A cold air circulation device 7 for returning to the cold air supply device 6 and a hot air supply device 8 for supplying hot air to the first heat retaining chamber 4 are provided. Here, the cold air supply device 6 includes a second chamber 62 composed of an air blowing chamber 62a, a duct chamber 62b, and an air blowing chamber 62c, and a cold air generating device 61 installed in the duct chamber 62b. The hot air supply device 8 includes a first chamber 82 composed of a blower chamber 82a, a duct chamber 82b, and a blower chamber 82c, and a hot air generator 81 installed in the duct chamber 82b.

  As shown in FIG. 2, the cold air circulation device 7 includes a first duct 71 that communicates the first heat insulation chamber 4 and the cold air supply device 6, and the cold air supplied to the first heat insulation chamber 4 in the first duct 71. A first fan 72 for blowing air.

  A first valve 73 is provided in the first duct 71. The first valve 73 closes the inside of the first duct 71 when the first heat insulating chamber 4 is used as a temperature storage, while the inside of the first duct 71 is cold air when the first heat insulating chamber 4 is used as a refrigerator. It is configured to open so as to flow. More specifically, when cold air flows in the first duct 71 as shown in FIG. 6, the first valve 73 opens the first duct 71 by the wind pressure of the cold air, and as shown in FIG. When cold air does not flow in one duct 71, the first duct 71 is closed by its own weight. Further, as shown in FIG. 3, the first valve 73 is pivotally supported at the upper part, and when the inside of the first duct 71 is closed, the cold air flowing from the first heat insulation chamber 4 to the cold air supply device 6 is supported. It is provided so as to incline downward from the windward side toward the leeward side. The specific configuration of the first valve 73 will be described in detail later.

  In addition, a second fan 74 is provided in the first duct 71 as shown in FIG. In the first embodiment, the first duct 71 is also in communication with the second heat insulating chamber 5 through the opening 71a. When the first valve 73 closes the inside of the first duct 71, that is, when the first heat insulation 4 is used as a heat storage, the second fan 74 has an inside in the second heat insulation 5 as shown in FIG. 4. The cool air supplied to is supplied to the cool air supply device 6 through the first duct 71. In addition, when the first valve 73 opens the inside of the first duct 71, that is, when the first heat insulating box 4 is used as a refrigerator, the second fan 74 has an inside of the second heat insulating box 5 as shown in FIG. 7. The cool air that has passed through the first valve 73 together with the cool air supplied to the cool air is sent to the cool air supply device 6.

  As shown in FIG. 2, the hot air supply device 8 includes a hot air generation device 81 that generates hot air, a first chamber 82 that houses the hot air generation device 81 and communicates with the first heat insulating chamber 4, and a first chamber 82. A second duct 83 communicating with the first heat storage 4 is provided. In the second duct 83, a third fan 84 that blows hot air supplied to the first heat retaining chamber 4 to the first chamber 82 is provided.

  The hot air generating device 81 heats the circulating air to change it into hot air, and is, for example, a heater such as a sheathed heater, a panel heater, or a PTC heater.

  FIG. 9 is an exploded perspective view schematically showing the structure of the first chamber 82. As shown in FIG. 9, the 1st chamber 82 is provided with the ventilation chamber 82a, the duct chamber 82b, and the ventilation chamber 82c. The air blowing chamber 82a, the duct chamber 82b, and the air blowing chamber 82c are each formed in a cylindrical shape and arranged so as to be aligned in that order.

  The duct chamber 82 b is formed in a size that accommodates the hot air generator 81. As shown in FIGS. 4 and 7, the upper portion of the duct chamber 82 b communicates with the first heat storage 4 via the second duct 83. As shown in FIG. 9, an opening 82d that communicates with the blower chamber 82a and an opening 82e that communicates with the blower chamber 82c are provided at the lower portion of the duct chamber 82b. A plurality of air blowing holes 82f are provided on the surface of the air blowing chamber 82a facing the first heat insulating chamber 4. A plurality of air holes 82g are provided on the surface of the air chamber 82c facing the first heat insulating chamber 4. In the drawing, four ventilation holes are schematically shown in the vertical direction, but the actual number of ventilation holes is set according to the number of trays (6 to 12 stages) stored in the heat insulation box in the vertical direction.

  The cold air supply device 6 accommodates the cold air generation device 61 that generates the cold air, the second chamber 62 that houses the cold air generation device 61, and communicates with the second heat insulating chamber 5, and the first chamber 82 and the second chamber 62 communicate with each other. The third duct 63 is provided. A fourth fan 64 that blows hot air generated by the cold air generating device 61 to the first chamber 82 is provided in the third duct 63.

  The cold air generating device 61 cools the circulated air and changes it into cold air, and is a cooling device such as an evaporator. In the first and second embodiments, the compressor that performs cooling in cooperation with the evaporator is disposed, for example, at the lower portion of the moving device 2 and connected by piping. In the third embodiment, for example, the heat retaining device 3A. It is arranged at the top of the pipe and connected by piping.

  FIG. 10 is an exploded perspective view of the second chamber 62. As shown in FIG. 10, the second chamber 62 includes a blower chamber 62a, a duct chamber 62b, and a blower chamber 62c. The blower chamber 62a, the duct chamber 62b, and the blower chamber 62c are each formed in a cylindrical shape and arranged so as to be aligned in that order.

  The duct chamber 62 b is formed in a size that accommodates the cold air generating device 61. The upper part of the blower chamber 62 c communicates with the duct chamber 82 b of the first chamber 82 via the third duct 63. As shown in FIG. 10, an opening 62d that communicates with the blower chamber 62a and an opening 62e that communicates with the blower chamber 62c are provided at the lower portion of the duct chamber 62b. A plurality of air blowing holes 62f are provided on the surface of the air blowing chamber 62a facing the second heat insulating box 5. A plurality of air blowing holes 62g are provided on the surface of the air blowing chamber 62c facing the second heat insulating chamber 5.

  Further, in the third duct 63, when the first heat insulating chamber 4 is used as a heat storage, the inside of the third duct 63 is closed, while when the first heat insulating chamber 4 is used as a refrigerator, the third duct 63 is closed. A second valve 65 is provided to open so as to allow the cool air to flow through 63.

  When the cold air flows through the third duct 63 as shown in FIG. 8, the second valve 65 opens the inside of the third duct 63 by the wind pressure of the cold air, and as shown in FIG. When there is no flow, the third duct 63 is closed by its own weight. Further, as shown in FIG. 5, the second valve 65 is pivotally supported at the upper part, and when the inside of the third duct 63 is closed, the cold air flowing from the second chamber 62 to the first chamber 82 is provided. It is provided so as to incline downward from the upper side toward the leeward side.

  Moreover, as shown in FIG. 2, between the 1st fan 72 of the 1st duct 71 and the 1st valve 73, it detects for the temperature of the cold air supplied to the 1st heat retention box 4 in the total cooling mode. A temperature sensor 91 is provided. A temperature sensor 92 is provided between the opening 71a of the first duct 71 and the second fan 74 to detect the temperature of the cold air supplied to the second heat insulation chamber 5 in the normal mode and the full cooling mode. It has been. A temperature sensor 93 is provided between the third fan 84 of the second duct 83 and the duct chamber 82b for detecting the temperature of the hot air supplied to the first heat insulation in the normal mode. The detected temperatures of these temperature sensors 91 to 93 are transmitted to a control unit (not shown) included in the heat retaining device 3. The said control part controls the drive of each fan and each production | generation apparatus of the cold air supply apparatus 6, the cold air circulation apparatus 7, and the hot air supply apparatus 8 based on the detection temperature of the temperature sensors 91-93, and normal mode and all-cooling mode Execute. Since the third fan 84 is operating when the first heat storage 4 functions as a heat storage in the normal mode, the temperature of the first heat storage 4 is measured by the temperature sensor 93. On the other hand, when the first heat insulating chamber 4 functions as a refrigerator in the full cooling mode, the first fan 72 is operating but the third fan 84 is stopped, so the temperature at the position of the temperature sensor 93 is hot air. Is retained and does not reflect the temperature of the first heat insulating chamber 4, and is measured by the temperature sensor 91.

  Next, the configuration of the first valve 73 of the cold air circulation device 7 will be described more specifically.

  FIG. 11 is an enlarged cross-sectional view showing a state where the first valve 73 is attached to the first duct 71. In the first embodiment, the first valve 73 is mainly composed of two members, a frame 73a and a rotating plate 73b. The frame 73a and the rotating plate 73b are made of, for example, stainless steel. The first duct 71 is made of resin, for example. The frame 73a is installed with an inclination of θ degrees with respect to the vertical direction. In order to prevent the valve from being opened even when the food transport vehicle 1 is tilted several degrees (for example, 5 degrees) due to traveling on a slope, for example, it is tilted by 15 degrees.

  FIG. 12A is a front view of the frame 73a. FIG. 12B is a side view of the frame 73a. As shown in FIG. 12A, the frame 73a is formed in an annular shape. As shown in FIG. 11, the frame body 73 a is attached so that the outer peripheral portion fits into the groove portion 71 b provided on the inner peripheral surface of the first duct 71. The groove 71b is formed in an annular shape so as to fit the entire circumference of the outer periphery of the frame 73a, for example. Thereby, the airtightness between the frame 73a and the 1st duct 71 is ensured.

  The opening 73aa of the frame 73a is formed in a substantially rectangular shape, but two depressions 73ab are formed in the upper part of the frame 73a so that the length in the width direction of the upper part becomes longer. Each of the two recessed portions 73ab is formed with a bearing portion 73ac that protrudes in a direction orthogonal to the main surface of the frame 73a.

  FIG. 13 is a perspective view of the rotating plate 73b. As shown in FIG. 13, the rotating plate 73b is formed so as to cover the opening 73aa of the frame 73a. That is, the width W2 of the rotation plate 73b is larger than the width W1 of the opening 73aa, and the height H2 of the rotation plate 73b is formed larger than the height H1 of the opening 73aa. A pair of bearing portions 73ba are provided on the rotating plate 73b at positions corresponding to the pair of bearing portions 73ac of the frame 73a. The rotation plate 73b opens and closes the opening 73aa of the frame 73a from above by inserting a rotation shaft (not shown) into the holes provided in the pair of bearings 73ac and the pair of bearings 73ba, respectively. The upper part is pivotally supported so as to be freely covered.

  An elastic member such as rubber may be provided at the contact portion between the frame 73a and the rotating plate 73b. Thereby, the collision sound and impact by the collision of the frame 73a and the rotation board 73b can be reduced. Note that when the first valve 73 is opened and closed by the wind pressure of the cold air as in the first embodiment, the wind pressure of the cold air is not lowered suddenly but gradually, and the rotating plate 73b is It rotates slowly. For this reason, almost no impact sound and impact are generated, and therefore it is not necessary to provide an elastic member.

  In the first embodiment, the second valve 65 attached to the third duct 63 is configured in the same manner as the first valve 73. That is, the second valve 65 includes an annular frame body whose outer peripheral portion is fitted in a groove portion provided on the inner peripheral surface of the third duct 63, and an upper portion that is pivotally supported so as to be rotatable. And a rotating plate that covers the opening from above so as to be freely opened and closed. Since the specific description of the second valve 65 overlaps with the description of the first valve 73, it is omitted here.

  Next, the flow of hot air and cold air in the normal mode will be described with reference to FIGS.

  For example, when the user operates an operation panel (not shown) provided on the casing 31 of the heat retaining device 3 or when the normal mode is selected by reaching a time set in advance by a timer, the cold air generating device 61 The air that has been circulated is cooled and converted into cold air to generate cold air, and the hot air generator 81 heats the air that has been circulated and converts it into hot air to generate hot air. Further, the second fan 74 and the third fan 84 are driven (ON). At this time, the first fan 72 and the fourth fan 64 are in a non-driven (OFF) state. Moreover, the 1st valve 73 exists in the state which obstruct | occluded the inside of the 1st duct 71 with dead weight. The second valve 65 is in a state where the inside of the third duct 63 is closed by its own weight.

  As shown in FIG. 4, the cold air generated by the cold air generating device 61 is lowered in the duct chamber 62b by the wind force of the second fan 74 as shown by the solid line arrow in FIG. 10, and the lower opening of the duct chamber 62b is opened. The air enters the blower chambers 62a and 62c through the parts 62d and 62e. As shown in FIG. 3 or FIG. 5, the cool air that has entered the blower chambers 62 a and 62 c rises in the blower chambers 62 a and 62 c and is supplied to the second heat insulating chamber 5 through the plurality of blower holes 62 f and 62 g. As shown in FIG. 4, the cold air supplied to the second heat insulating chamber 5 enters the first duct 71 through the opening 71 a provided in the first duct 71, and opens the opening 71 c by the wind force of the second fan 74. Then, the duct chamber 62b is lowered again. During the normal mode, the second heat insulating box 5 functions as a refrigerator by circulating the cold air in this way. In the normal mode, the temperature in the second heat insulation box 5 is set to, for example, 5 to 10 ° C. (the temperature in the second heat insulation box 5 can be set to 3 to 10 ° C.).

  As shown in FIG. 4, the hot air generated by the hot air generator 81 descends in the duct chamber 82b by the wind force of the third fan 84 as shown by the white arrow in FIG. The air enters the blower chambers 82a and 82c through the openings 82d and 82e. As shown in FIG. 3 or FIG. 5, the hot air that has entered the blower chambers 82 a and 82 c rises in the blower chambers 82 a and 82 c and is supplied to the first heat insulating chamber 4 through the blower holes 82 f and 82 g. As shown in FIG. 4, the hot air supplied to the first heat insulation chamber 4 enters the common duct 85 through the second duct 83 by the wind force of the third fan 84, and again enters the duct chamber 82b through the opening 85a. Descend. During the normal mode, the hot air circulates in this way, so that the first heat storage 4 functions as a heat storage. In the normal mode, for example, the temperature in the first heat insulation chamber 4 is set to 110 to 120 ° C. during reheating, and is set to 70 to 75 ° C. during heat insulation (the temperature in the first heat insulation chamber 4 is It can be set in two stages for reheating and heat retention, and can be set to 100 to 130 ° C. during reheating and 60 to 80 ° C. during heat retention).

  Next, with reference to FIGS. 6-8, the flow of the cold air in the all-cooling mode will be described.

  For example, when a user operates an operation panel (not shown) provided on the casing 31 of the heat retaining device 3 and the all-cooling mode is selected, the cold air generating device 61 cools the circulating air to cool air. Change to generate cold air. Further, the first fan 72, the second fan 74, and the fourth fan 64 are driven (ON). At this time, the third fan 84 is in a non-driven (OFF) state.

  As shown in FIG. 7, the cold air generated by the cold air generating device 61 is lowered in the duct chamber 62b by the wind force of the second fan 74 as shown by a solid line arrow in FIG. The air enters the blower chambers 62a and 62c through the parts 62d and 62e. As shown in FIG. 6 or FIG. 8, the cool air that has entered the blower chambers 62a and 62c rises in the blower chambers 62a and 62c.

  The cool air rising in the blower chambers 62a and 62c is supplied to the second heat insulating chamber 5 through the plurality of blower holes 62f and 62g. As shown in FIG. 7, the cold air supplied to the second heat insulating chamber 5 enters the first duct 71 through the opening 71 a provided in the first duct 71, and opens the opening 71 c by the wind force of the second fan 74. Then, the duct chamber 62b is lowered again.

  As shown in FIG. 8, a part of the cool air rising in the blower chamber 62c passes through the third duct 63 by the wind force of the fourth fan 64, and the second valve 65 is opened by the wind pressure of the cool air. The cold air that has passed through the second valve 65 enters the common duct 85 and enters the duct chamber 82b through the opening 85a shown in FIG. The cool air that has entered the duct chamber 82b descends in the duct chamber 82b and enters the blower chambers 82a and 82c through the openings 82d and 82e below the duct chamber 82b, as indicated by solid arrows in FIG. As shown in FIG. 6 or FIG. 8, the cool air that has entered the blower chambers 82a and 82c rises in the blower chambers 82a and 82c, and is supplied to the first heat insulating chamber 4 through the blower holes 82f and 82g.

  As shown in FIG. 6, the cold air supplied to the first heat insulating chamber 4 passes through the first duct 71 by the wind force of the first fan 72, and the first valve 73 is opened by the wind pressure of the cold air. The cold air that has passed through the first valve 73 is merged with the cold air generated in the normal mode described in FIG. 4 by the wind force of the second fan 74 shown in FIG. 7, and passes through the opening 71c provided in the first duct. And enters the duct chamber 62b and descends in the duct chamber 62b as shown by the solid line arrow in FIG.

  During the all-cooling mode, the cool air circulates in this way, so that the first heat insulation chamber 4 and the second heat insulation chamber 5 function as a refrigerator. In the all-cooling mode, the temperature in the first heat insulation chamber 4 and the second heat insulation chamber 5 is set to 3 ° C., for example.

  According to this 1st Embodiment, since the cold wind circulation apparatus 7 which returns the cold wind supplied to the 1st heat storage 4 to the cold air supply apparatus 6 is provided, the 1st heat storage 4 and the 2nd heat storage in the full cooling mode are provided. The cooling rate in 5 can be improved. For example, when the time required for the heat retaining device of Patent Document 1 to cool each heat retaining chamber from room temperature to about 3 ° C. is 50 to 60 minutes, by adopting the configuration of the heat retaining device according to the first embodiment. The time can be shortened to about 30 to 40 minutes.

  In addition, when an electric valve such as a ball valve or a butterfly valve or an electromagnetic valve is used as a valve as in the heat retaining device of Patent Document 1, the flow path diameter is smaller than the outer diameter of those valves, so There is a problem that the path resistance is large, and those valves are made of metal and are in contact with the heat retaining device 3, so that heat loss is large. Furthermore, this type of motor-operated valve or solenoid valve is expensive, and even if the valve itself is not broken, the relay that controls the valve may be broken.

  On the other hand, according to the first embodiment, the first valve 73 is configured to open the inside of the first duct 71 by the wind pressure of the cold air when the cold air flows into the first duct 71. That is, as the first valve 73, a valve that is passively opened by receiving wind pressure of cold air is used. Further, the first valve 73 is configured to close the inside of the first duct 71 by its own weight when cold air does not flow into the first duct 71. According to this configuration, since an electric valve or a solenoid valve is not used, initial cost and running cost can be suppressed.

  In addition, according to the first embodiment, the first valve 73 is pivotally supported at the upper part, and flows from the first heat retaining chamber 4 to the cold air supply device 6 when the inside of the first duct 71 is closed. It is provided so as to incline downward from the windward side of the cold wind toward the leeward side. According to this configuration, it is possible to suppress the backflow of cold air from the cold air supply device 6 to the first heat retaining chamber 4 with a simple configuration in which the first valve 73 is disposed at an inclination. Moreover, compared with the case where an electric valve or a solenoid valve is used, the cross-sectional area of the first duct 71 can be increased, and the amount of cold air flowing through the first duct 71 can be increased to improve the cooling efficiency. . In addition, since the flow path resistance can be reduced by increasing the cross-sectional area of the first duct 71, a fan with low wind power can be used as the first fan 72 and the second fan 74.

  Further, according to the first embodiment, the second valve 65 is configured to open the inside of the third duct 63 by the wind pressure of the cold air when the cold air flows into the third duct 63. That is, as the second valve 65, a valve that is passively opened by receiving wind pressure of cold air is used. Further, the second valve 65 is configured to close the inside of the third duct 63 by its own weight when cold air does not flow into the third duct 63. According to this configuration, since an electric valve or a solenoid valve is not used, initial cost and running cost can be suppressed.

  Further, according to the first embodiment, the second valve 65 is pivotally supported at the upper part thereof, and cool air flowing from the second chamber 62 to the first chamber 82 when the inside of the third duct 63 is closed. It is provided so as to incline downward from the windward side toward the leeward side. According to this configuration, it is possible to suppress the backflow of hot air from the first chamber 82 to the second chamber 62 with a simple configuration in which the second valve 65 is disposed at an inclination. Moreover, compared with the case where an electric valve or a solenoid valve is used, the cross-sectional area of the third duct 63 can be increased, and the cooling air efficiency can be improved by increasing the amount of cold air flowing through the third duct 63. . In addition, the flow path resistance can be reduced by increasing the cross-sectional area of the third duct 63.

  In the first embodiment, both the first valve 73 and the second valve 65 are valves that passively open by receiving wind pressure of cold air, but the present invention is not limited to this. One of the first valve 73 and the second valve 65 may be a valve that passively opens by receiving wind pressure of cold air.

  Note that the first valve 73 and the second valve 65 may have their own weights adjusted so that the valves are not opened even when the food transport vehicle 1 is tilted several degrees (for example, 5 degrees) due to traveling on a slope. preferable. Thereby, it can suppress that the 1st valve 73 and the 2nd valve 65 are opened unintentionally. In addition, you may make it adjust own weight by attaching the weight 73c to the rotation board 73b of the 1st valve 73 and the 2nd valve 65 like FIG. 13B.

  In addition, in the heat retaining device 3 according to the first embodiment, when the operation in the full cooling mode is started immediately after the operation in the normal mode, the hot air in the first heat retaining chamber 4 that has become high temperature passes through the first duct 71 to cool air. There is a risk of being supplied to the supply device 6. In this case, when hot air hits the evaporator, the refrigerant gas inside may expand and the piping or the like may be damaged, and the cooling efficiency will be lowered even if the evaporator is not damaged. For this reason, after operating in the normal mode, it is possible to control so that the operation in the cooling mode is not started for a predetermined time until the temperature in the first heat insulating chamber 4 is lowered to a predetermined temperature (for example, 50 ° C.). preferable. As a result, it is possible to suppress a decrease in cooling efficiency and to prevent the hot air generator 81 from failing. Note that the second fan 74 and the third fan 84 may be driven for a predetermined time after operating in the normal mode in order to quickly cool the first heat-reserving chamber 4 that has reached a high temperature.

  In the first embodiment, as the first fan 72, the second fan 74, the third fan 84, and the fourth fan 64, for example, a sirocco fan, a cross flow fan, a propeller fan (including an axial fan), etc. Can be used. Among each fan, the 2nd fan 74 is driven when using the 1st heat storage 4 by either a warm storage or a refrigerator. On the other hand, the second fan 74 is provided to return the cold air flowing through the first duct 71 to the cold air supply device 6, and does not need to have wind force that opens the first valve 73 unlike the first fan 72. . For this reason, the second fan 74 may be a fan having a smaller storage space than the first fan 72, the third fan 84, and the fourth fan 64 but having a small storage space, such as an axial fan. Here, the small wind force means that the air volume obtained with respect to the required static pressure is small in the generally known static pressure P-wind force Q characteristics. Thereby, the initial cost and running cost which the 2nd fan 74 requires can be held down. Further, since the storage property is good, the food transport vehicle 1 can be arranged inside the food transport vehicle 1 without increasing the outer shape of the food transport vehicle 1.

  In the first embodiment, one each of the first fan 72, the second fan 74, the third fan 84, and the fourth fan 64 is provided, but the present invention is not limited to this. A plurality may be provided in consideration of wind power required for each fan, installation space, and the like.

(Second Embodiment)
FIG. 14 is a perspective view of a food transport vehicle including a heat retaining device according to the second embodiment of the present invention. FIG. 15 is a top view of the food transport vehicle of FIG. 16 is a cross-sectional view taken along line B1-B1 of FIG.

  The food transport vehicle 1A according to the second embodiment is configured so that the two food transport vehicles 1 according to the first embodiment share the hot air generating device 81 and the first chamber 82 of the hot air supply device 8 of each other. It has a connected configuration. In other words, the food transport vehicle 1A according to the second embodiment includes two sets of the cold air supply device 6 and the cold air circulation device 7, which are pointed around the hot air generation device 81 of the hot air supply device 8 in plan view. It is comprised so that it may be arrange | positioned. Devices and components similar to those according to the first embodiment are given the same reference numerals, and redundant descriptions are omitted.

  The food transport vehicle 1A according to the second embodiment has a configuration in which two food transport vehicles 1 are connected so as to share the hot air generation device 81 and the first chamber 82 of the hot air supply device 8 of each other. Therefore, it is possible to realize a reduction in size and cost compared to simply connecting the two food transport vehicles 1. In addition, since one hot air generating device 81 is arranged at the center so that the hot air flows to both ends, the hot air generating device 81 that requires the most power can be driven efficiently.

  Further, in the food transport vehicle 1A according to the second embodiment, since the hot air generating device 81 is configured to be shared, the temperature of the hot air and the temperature of the cold air supplied into the two first heat insulation chambers 4 are used. Can be assumed to be the same or nearly the same. For this reason, it is only necessary to provide one each of the temperature sensors 91 and 93 for measuring the temperature of the hot air or the cold air supplied into the first heat insulation chamber 4. Thereby, cost reduction can be achieved.

(Third embodiment)
FIG. 17 is a perspective view of a heat retaining device according to the third embodiment of the present invention. 18 is a top view of the heat retaining device of FIG. 19 is a cross-sectional view taken along line C1-C1 of FIG. 20 is a cross-sectional view taken along line C2-C2 of FIG. 21 is a cross-sectional view taken along line C3-C3 of FIG.

  The heat retaining device 3A according to the third embodiment is a stationary device that does not include the moving device 2. Instead of moving the entire device, the first heat retaining chamber 4 and the second heat retaining chamber 5 are provided with traveling casters 14. It is configured as an insert cart 3B and configured to move.

  In the heat retaining device 3A according to the third embodiment, since it is not necessary to move the entire device, downsizing of the device is not required as much as the heat retaining device 3 according to the first embodiment. For this reason, as shown in FIGS. 18 and 19, the second fan 74 is horizontally disposed in the second chamber 62. In this case, compared with the case where the 2nd fan 74 is diagonally arrange | positioned in the 1st duct 71, flow-path resistance can be made small and the cold wind which flows through the 2nd chamber 62 and the 2nd heat retention box 5 can be efficiently carried out. It can be circulated.

  Further, in the heat retaining device 3A according to the third embodiment, instead of providing the opening 71a that communicates the second heat retaining chamber 5 and the first duct 71, the duct of the second heat retaining chamber 5 and the second chamber 62 is provided. An opening 62h communicating with the chamber 62b is provided. The opening 62 h is provided at a position higher than the second fan 74. According to this configuration, the cool air flowing through the second chamber 62 and the second heat insulating cabinet 5 can be circulated more efficiently.

  In addition, since it is the same as that of the heat retention apparatus 3 which concerns on the said 1st Embodiment about another point, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  Next, with reference to FIGS. 19-21, the flow of the cold air in the all-cooling mode will be described.

  For example, when a user operates an operation panel (not shown) provided on the casing 31 of the heat retaining device 3A and the all-cooling mode is selected, the cold air generating device 61 cools the circulating air to cool air. Change to generate cold air. Further, the first fan 72, the second fan 74, and the fourth fan are driven (ON). At this time, the third fan 84 is in a non-driven (OFF) state.

  As shown in FIG. 20, the cold air generated by the cold air generating device 61 is lowered in the duct chamber 62b by the wind force of the second fan 74 as shown by the solid line arrow in FIG. 10, and the lower opening of the duct chamber 62b is opened. The air enters the blower chambers 62a and 62c through the parts 62d and 62e. As shown in FIG. 21, the cool air that has entered the blower chambers 62a and 62c rises in the blower chambers 62a and 62c.

  The cool air rising in the blower chambers 62a and 62c is supplied to the second heat insulating chamber 5 through the plurality of blower holes 62f and 62g. As shown in FIG. 20, the cold air supplied to the second heat insulating chamber 5 enters the duct chamber 62b through an opening 62h provided in the upper portion of the duct chamber 62b, and is again returned to the duct chamber 62b by the wind force of the second fan 74. Descend.

  As shown in FIG. 21, a part of the cool air rising in the blower chamber 62c passes through the third duct 63 by the wind force of the fourth fan 64, and the second valve 65 is opened by the wind pressure of the cool air. The cold air that has passed through the second valve 65 enters the common duct 85, passes through the opening 85a, and enters the duct chamber 82b as shown by the solid line arrow in FIG. The cool air that has entered the duct chamber 82b descends in the duct chamber 82b and enters the blower chambers 82a and 82c through the openings 82d and 82e at the lower part of the duct chamber 82b. As shown in FIG. 19, the cool air that has entered the air blowing chambers 82a and 82c rises in the air blowing chambers 82a and 82c, and is supplied to the first heat insulating chamber 4 through the air blowing holes 82f and 82g.

  As shown in FIG. 19, the cold air supplied to the first heat insulating chamber 4 passes through the first duct 71 by the wind force of the first fan 72, and the first valve 73 is opened by the wind pressure of the cold air. The cold air that has passed through the first valve 73 enters the duct chamber 62b through the opening 71d provided in the first duct by the wind force of the second fan 74, and as shown by the solid line arrow in FIG. It descends in 62b and merges with the cool air generated in the normal mode described in FIG.

  During the all-cooling mode, the cool air circulates in this way, so that the first heat insulation chamber 4 and the second heat insulation chamber 5 function as a refrigerator.

  It is to be noted that, by appropriately combining any of the various embodiments, the effects possessed by them can be produced.

  While the invention has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included therein, so long as they do not depart from the scope of the present invention according to the appended claims.

  Since this invention can improve the cooling rate in the 1st heat storage and the 2nd heat storage in the all-cooling mode, for example, it is a cook chill system used in facilities such as hospitals, health care facilities for the elderly, hotels and schools. It is useful for a heat retaining device having such a reheating function and a food transport vehicle including the heat retaining device.

DESCRIPTION OF SYMBOLS 1 Food conveyance vehicle 1A Food conveyance vehicle 2 Moving device 3 Thermal insulation device 3A Thermal insulation device (stationary type)
3B Insert Cart with Traveling Casters 3C Partition Unit 4 First Warm Storage 5 Second Warm Storage 6 Cold Air Supply Device 7 Cold Air Circulation Device 8 Hot Air Supply Device 9 Partition 10 Projection 11 Sealing Member 12 Sealing Member 13 Caster 14 Traveling Caster 31 Housing 32 Insulation space 41 Tray 61 Cold air generator 62 Second chamber 62a, 62c Blower chamber 62b Duct chamber 62d, 62e Opening 62f, 62g Blower hole 63 Third duct 64 Fourth fan 65 Second valve 71 First duct 71a Opening 71b Groove 71c Opening 71d Opening 72 First fan 73 First valve 73a Frame 73b Rotating plate 73c Weight 74 Second fan 81 Hot air generator 82 First chamber 82a, 82c Blower chamber 82b Duct chamber 82d, 82e Opening 82f, 82g Blower hole 83 2nd Duct 84 Third fan 85 Common duct 85a Opening 91-93 Temperature sensor

Claims (14)

It is a heat retention device having a reheating function including at least one first heat storage that can be used by switching to either a heat storage or a refrigerator, and at least one second heat storage that can be used as a refrigerator,
When using the first heat storage as a refrigerator, a cold air supply device that supplies cold air to the first heat storage and the second heat storage;
A cold air circulation device that returns the cold air supplied to the first heat insulation chamber to the cold air supply device;
A heat retention device. The cold air circulation device is
A first duct communicating the first heat storage and the cold air supply device;
A first fan that blows cool air supplied to the first heat insulation into the first duct;
The first duct is provided in the first duct and closes the inside of the first duct when the first heat storage is used as a heat storage, while the first duct is used when the first heat storage is used as a refrigerator. A first valve that opens to allow cold air to flow therein;
When the first valve closes the first duct, the cool air supplied into the first heat insulation box is blown to the cool air supply device, while when the first valve opens the first duct, A second fan that blows the cold air that has passed through the first valve together with the cold air supplied into the first heat insulation chamber to the cold air supply device;
The heat insulating device according to claim 1, comprising:   The heat retention device according to claim 2, wherein the first valve is configured to open the inside of the first duct by a wind pressure of the cold air when the cold air flows through the first duct.   The heat retaining device according to claim 2 or 3, wherein the first valve is configured to close the inside of the first duct by its own weight when cold air does not flow in the first duct.   The first valve is pivotally supported at the upper part, and when the inside of the first duct is closed, the first valve moves downward from the windward side to the leeward side of the cold wind flowing from the first heat insulation box to the cold wind supply device. The heat retaining device according to any one of claims 2 to 4, wherein the heat retaining device is provided so as to be inclined. The first valve is
An annular frame having an outer peripheral portion fitted into a groove provided on the inner peripheral surface of the first duct;
A rotating plate pivotally supported on the upper part and covering the opening of the annular frame so as to be openable and closable from above;
The heat retaining device according to claim 5, comprising: The heat retention device further includes a hot air supply device that supplies hot air to the first heat insulation when using the first heat insulation as a heat storage,
The hot air supply device is
A hot air generating device for generating hot air;
A first chamber that houses the hot air generator and communicates with the first warmer;
A second duct communicating the first chamber and the first heat storage;
A third fan for blowing the hot air supplied to the first heat storage into the first chamber;
With
The cold air supply device is
A cold air generator for generating cold air;
A second chamber that houses the cold air generation device and communicates with the second heat storage;
A third duct communicating the first chamber and the second chamber;
A fourth fan for blowing cold air generated by the cold air generation device to the first chamber;
The third duct is provided in the third duct and closes the inside of the third duct when the first heat insulation is used as a heat storage, while the third duct is used when the first heat insulation is used as a refrigerator. A second valve that opens to allow cold air to flow therein;
The heat retention apparatus according to any one of claims 2 to 6, comprising:   The second fan is driven when the first warmer is used in either the warmer or the refrigerator, and has a smaller wind force than the first fan, the third fan, and the fourth fan. The heat insulating device according to claim 7.   The heat retaining device according to claim 7 or 8, wherein the second fan is provided in the second chamber.   The said 2nd valve is comprised so that the inside of the said 3rd duct may be open | released with the wind pressure of the said cold wind, when cold wind flows into the said 3rd duct. Thermal insulation device.   The heat retention device according to any one of claims 7 to 10, wherein the second valve is configured to close the inside of the third duct by its own weight when cold air does not flow in the third duct. .   The second valve is pivotally supported at the upper part, and when closing the inside of the third duct, the second valve moves downward from the windward side to the leeward side of the cold air flowing from the second chamber to the first chamber. The heat retention apparatus according to any one of claims 7 to 11, which is provided so as to be inclined. The second valve is
An annular frame having an outer peripheral portion fitted into a groove provided on the inner peripheral surface of the third duct;
A rotating plate pivotally supported on the upper part and covering the opening of the annular frame so as to be openable and closable from above;
The heat retaining device according to claim 12, comprising:   A food transport vehicle comprising the heat retaining device according to any one of claims 1 to 13.

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