Transport trolley

Abstract

To provide a carriage truck having proper heat-insulating properties in use.SOLUTION: A carriage truck 10 comprises a truck body 50, and a plurality of heat insulation panels 11-16 that are arranged like a box in the truck body 50 so as to constitute a heat-insulated container 30. At least four 11-16 of the plurality of heat insulation panels 11-16 have a vacuum heat insulation member including a vacuum heat insulation material. The heat-insulated container 30 has an air change rate set to be 0.1 / hr or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a transport dolly. [Background technology]

[0002] Conventionally, for example, in stores and factories, transport carts are used to transport food and other loads. Such transport carts have a cart (cart body) having a pair of side frames. A heat-insulating cart cover is attached to the cart to keep the food and other loads warm, cold, or protected. For example, one disclosed in Patent Document 1 is known as such a transport cart. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-233970 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional cart covers for transport carts are generally made of, for example, sewn sheet materials, and are thin and flexible (see, for example, Patent Document 1). For this reason, there is a problem that it is difficult to sufficiently improve the heat insulating performance of conventional cart covers.

[0005] The present disclosure provides a transport cart that provides good thermal insulation during use. [Means for solving the problem]

[0006] The transport cart according to this embodiment is a transport cart comprising a cart body and a plurality of insulating panels which are arranged in a box shape on the cart body to form an insulating container, at least four of the plurality of insulating panels have vacuum insulating members including vacuum insulation material, and the insulating container has a ventilation rate of 0.1 times / hr or less.

[0007] The transport cart of this embodiment is a transport cart comprising a cart body and a plurality of insulating panels which are arranged in a box shape on the cart body to form an insulating container, at least four of the plurality of insulating panels have vacuum insulation members including vacuum insulation material, and the insulating container has a value equal to or less than which the rate of change of the cold retention time in the common logarithm of the ventilation rate is -1.

[0008] In the transport cart according to this embodiment, the internal volume of the heat-insulating container is 0.2 m 3 It may be more than that.

[0009] In the transport cart according to this embodiment, the external volume of the heat-insulating container is V A The internal volume is V B In this case, (V A -V B ) / V A The value may be 1 / 3 or less.

[0010] In the transport cart according to this embodiment, the ventilation rate may be 0.02 times / hr or more.

[0011] In the transport cart according to the present embodiment, the average heat transmission coefficient of the insulation panel having the vacuum insulation member including each of the vacuum insulation materials is 0.5 W / m 2 It may be less than K.

[0012] In the transport cart of this embodiment, the multiple insulation panels may be capable of assuming an expanded state in which the multiple insulation panels are expanded into a box shape, and a folded state in which the multiple insulation panels are folded.

[0013] In the transport cart according to this embodiment, the plurality of insulating panels may be capable of being nested with other transport carts when in the folded state.

[0014] In the transport cart according to this embodiment, the plurality of insulating panels may have at least a top panel, a front panel, a rear panel, and a pair of side panels, and the front panel may be openable.

[0015] In the transport cart according to this embodiment, at least some of the plurality of insulating panels may be fixed to the cart body.

[0016] In the transport cart according to this embodiment, the plurality of insulating panels may be arranged in a box shape and removably attached to the cart body. Effect of the Invention

[0017] According to this embodiment, it is possible to improve the heat insulation during use. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view of a transportation cart according to one embodiment, showing each heat insulating panel in an expanded state. [Diagram 2] FIG. 2 is a perspective view of the transportation cart according to the embodiment, showing only the front panel in a folded state. [Diagram 3] FIG. 3 is a perspective view of the transport cart according to the embodiment, showing the insulating panels in a folded state. [Figure 4] FIG. 4 is a perspective view showing the carriage body. [Diagram 5] 5(a) and (b) are schematic cross-sectional views illustrating examples of vacuum insulation materials. [Figure 6] 6(a)-(d) are schematic cross-sectional views illustrating examples of vacuum insulation members. [Figure 7] 7(a) and (b) are schematic cross-sectional views illustrating a vacuum insulation panel. [Figure 8] 8(a) to 8(c) are schematic cross-sectional views illustrating examples of vacuum insulation members. [Figure 9]9(a)-(d) are schematic diagrams illustrating the joint between two vacuum insulation panels. [Figure 10] 10(a) and (b) are perspective views showing a transportation cart according to the first modification. [Figure 11] 11(a) to 11(c) are perspective views showing a transportation cart according to the second modification. [Figure 12] FIG. 12 is a perspective view showing a transportation cart according to the third modification. [Figure 13] FIG. 13 is a perspective view showing a transportation cart according to the fourth modification. [Figure 14] FIG. 14 is a side view showing the carriage body according to the fifth modification. [Figure 15] FIG. 15 is a graph showing the relationship between the cooling time and the ventilation rate in a simulation. [Figure 16] FIG. 16 is a graph showing the relationship between the cooling time and the ventilation rate in a simulation. [Figure 17] FIG. 17 is a graph showing the rate of change of the cooling time in the common logarithm of the ventilation rate in a simulation. [Figure 18] FIG. 18 is a graph showing the rate of change of the cooling time in the common logarithm of the ventilation rate in a simulation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment will be described below with reference to the drawings. Each of the figures shown below is a schematic illustration. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, it is possible to carry out appropriate modifications within the scope of the technical idea. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values ​​such as the dimensions of each member and the material names described in this specification are examples of an embodiment, and are not limited to these, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are intended to include substantially the same state in addition to their strict meanings.

[0020] In the following embodiments, the "X direction" refers to a direction parallel to the longitudinal direction of the transport cart and parallel to the floor surface on which the transport cart is placed, and the "Y direction" refers to a direction perpendicular to the X direction and parallel to the floor surface on which the transport cart is placed. The "Z direction" refers to a direction parallel to the vertical direction. The "front" refers to a surface perpendicular to the floor surface that faces the direction in which other transport carts enter when nesting, and the "back" refers to a surface perpendicular to the floor surface that faces the front. The "top surface" refers to a surface parallel to the floor surface that is the upper side of the transport cart, and the "bottom surface" refers to a surface parallel to the floor surface that is the lower side of the transport cart. The "side surface" refers to a surface perpendicular to the floor surface that is the longitudinal end side of the transport cart.

[0021] (Configuration of the transport cart) The configuration of the transport dolly according to this embodiment will be described with reference to Figs. 1 to 4. Fig. 1 is a perspective view of the transport dolly according to this embodiment in an unfolded state. Fig. 2 is a perspective view of the transport dolly according to this embodiment, in which only the front panel is folded. Fig. 3 is a perspective view of the transport dolly according to this embodiment in a folded state. Fig. 4 is a perspective view of the dolly body. Note that the transport dolly is "unfolded" when each insulation panel of the transport dolly is unfolded, each insulation panel is assembled into a box shape, and insulation spaces are formed between the multiple insulation panels. Also, the transport dolly is "folded" when each insulation panel of the transport dolly is folded, and insulation spaces are not formed between the multiple insulation panels.

[0022] As shown in Figures 1 to 3, the transport cart 10 according to this embodiment includes a cart body (cart) 50, and a plurality of (six in this case) insulating panels 11-16 that are each provided on the cart body 50 so as to be freely unfolded and folded. The insulating panels 11-16 can be unfolded and assembled into a box-like unfolded state (see Figure 1), or folded and nested with other transport carts (see Figure 3). The insulating panels 11-16 are unfolded and arranged in a box-like state to form an insulating container 30.

[0023] The transport dolly 10 is used, for example, in stores, factories, logistics processes, etc., when storing or transporting loads that require cooling or heating. Such a transport dolly 10 is configured such that the heat-insulating space 20 capable of storing the load is surrounded by six heat-insulating panels 11-16, thereby minimizing temperature changes inside the transport dolly 10. On the other hand, when the transport dolly 10 is not in use, it can be nested with another identical transport dolly 10 (part of the transport dolly 10 can be overlapped with another transport dolly 10 adjacent in the horizontal direction) to store multiple transport dollies 10 in a compact manner.

[0024] Next, the configuration of the dolly body (dolly) 50 according to this embodiment will be described with reference to Fig. 4. As shown in Fig. 4, the dolly body 50 has a first side frame 51, a second side frame 52, and a connecting member 53 that connects the first side frame 51 and the second side frame 52 to each other. In this case, the dolly body 50 has six wheels 61-66, and the wheels 61-66 are attached to the connecting member 53 so as to face downward.

[0025] The first side frame 51 is provided at one longitudinal end (negative end in the X direction) of the cart body 50, and protrudes upward (positive side in the Z direction) from the connecting member 53. The first side frame 51 is formed in a ladder shape, and has a pair of vertical bars 55 extending in the up-down direction (Z direction) and a number of horizontal rails 56 extending horizontally (Y direction) between the pair of vertical bars 55.

[0026] The second side frame 52 is provided at the other longitudinal end (positive end in the X direction) of the cart body 50, and protrudes upward (positive side in the Z direction) from the connecting member 53. The configuration of the second side frame 52 is substantially the same as the configuration of the above-mentioned first side frame 51, and is configured and arranged so as to be point-symmetrical with the first side frame 51 in a plan view.

[0027] The connecting member 53 is roughly O-shaped when viewed from the top (the shape of two "E" letters back to back), and has a central frame 57 extending in the longitudinal direction (X direction) of the bogie body 50, and three wheel mounting frames 67-69 (first wheel mounting frame 67, second wheel mounting frame 68, third wheel mounting frame 69) each connected to the central frame 57.

[0028] The central frame 57 is located at approximately the center in the width direction (Y direction) of the cart body 50. Note that the central frame 57 is provided at a higher position than the wheel mounting frames 67-69 so as not to interfere with the wheel mounting frames 67-69 of other transport carts 10 during nesting.

[0029] The first wheel mounting frame 67, the second wheel mounting frame 68, and the third wheel mounting frame 69 are arranged at intervals from each other in the longitudinal direction (X direction) of the bogie body 50. Furthermore, a first wheel 61 and a second wheel 62 are attached to the first wheel mounting frame 67, a third wheel 63 and a fourth wheel 64 are attached to the second wheel mounting frame 68, and a fifth wheel 65 and a sixth wheel 66 are attached to the third wheel mounting frame 69.

[0030] A foldable, substantially rectangular parallelepiped bottom plate 58 is provided on the connecting member 53. The bottom plate 58 is movable relative to the connecting member 53, and can be in an unfolded state (see FIGS. 1, 2, and 4) in which it is disposed on the connecting member 53, and in a folded state (see FIG. 3) in which it is lifted relative to the connecting member 53 and folded around the second side frame 52.

[0031] (Configuration of the insulated container and the insulated panel) Next, the configurations of the heat-insulating container 30 and the heat-insulating panels 11 to 16 will be described with reference to Figs.

[0032] The insulating panels 11-16 are provided as a whole so as to be freely unfoldable and foldable with respect to the cart body 50, and as described above, can be in an unfolded state (FIG. 1) where they are unfolded and assembled into a box shape, and in a folded state (FIG. 3) where they can be nested. Also, FIG. 2 shows a case where only the front panel 12 of the insulating panels 11-16 is in the folded state.

[0033] As shown in Fig. 1, the insulating panels 11-16 are generally rectangular parallelepiped in the deployed state and constitute the insulating container 30, and include a top panel 11, a front panel 12, a back panel 13, a first side panel 14, a second side panel 15, and a bottom panel 16. The insulating panels 11-16 each have a generally rectangular main surface (a pair of widest surfaces facing opposite each other among the six surfaces constituting each insulating panel). Each insulating panel 11-16 is made of a rigid plate-like member and is designed not to flexibly deform during use.

[0034] In the unfolded state, the six insulating panels 11-16 surround the transport vehicle 10 to form an insulating space 20 for accommodating a load. When the insulating panels 11-16 are unfolded to form the insulating container 30, the insulating space 20 is formed in a substantially rectangular parallelepiped shape between the insulating panels 11-16. In addition, as described later, the insulating container 30 has a ventilation rate of less than a specific value in the unfolded state. Therefore, the inflow and outflow of heat from the outside of the insulating container 30 is restricted, and the insulating properties can be maintained. In addition, at least a part of the six insulating panels 11-16 is provided so as to be movable relative to the other insulating panels 11-16 adjacent to each other. This allows the transport vehicle 10 to be changed from the unfolded state in which the insulating space 20 is formed to the folded state in which the insulating space 20 is not formed, and from the folded state to the unfolded state. Therefore, when the transport vehicle 10 is not used, the insulating panels 11-16 are folded to allow nesting with other transport vehicle 10. In addition, in the deployed state, the peripheral edge of each of the six insulating panels 11 to 16 is in close contact with any of the other insulating panels 11 to 16, thereby ensuring that the insulating space 20 is airtight.

[0035] The internal volume of the heat-insulating container 30 is, for example, 0.2 m 3 It is preferable that the internal volume of the heat-insulating container 30 is 0.2 m or more. 3 In the case where the internal volume of the insulated container 30 is 0.3 m or more, the insulated space 20 can be sufficiently secured. In addition, the insulated container 30 has an advantage that it has good insulation properties when in use and can be made compact when not in use, making it possible to apply it to a large insulated container. Furthermore, a large insulated container has an advantage that it is possible to store or transport more items. The internal volume of the insulated container 30 is 0.3 m 3 Can be more than 0.5m 3 It may be more than 0.8m 3 In order to facilitate assembly and disassembly, the internal volume of the heat-insulating container 30 is set to 8.0 m 3 It can be the following:

[0036] Here, the external volume of the heat-insulating container 30 in the assembled state (deployed state) is V A The internal volume is V B In this case, the miniaturization index = (V A -V B ) / V A The external volume V is defined as A is the volume calculated from the outer shape of the insulated container 30 in the assembled state, and the internal volume V B is the volume calculated from the internal shape (insulation space) of the insulated container 30 in the assembled state. A -V B ) corresponds to the external volume of the insulated container 30 in an ideal disassembled (folded) state (when the insulating panels are stacked so that the internal volume is 0). A -V B ) is calculated by dividing the external volume V of the insulated container 30 in the assembled state by the A Dividing by this gives an index of miniaturization when changing from an assembled state to a disassembled state. (V A -V B ) / V A The value of may be, for example, 1 / 3 or less, or 1 / 4 or less. A -V B ) / V A The smaller the value, the more preferable.

[0037] (Top panel) The top panel 11 is a heat insulating panel located on the top side (positive side in the Z direction) in the unfolded state (FIG. 1), and is arranged parallel to the horizontal plane (XY plane). This top panel 11 has a structure that can be partially opened and closed, and has a first top partial panel 11a located on the first side frame 51 side, and a second top partial panel 11b located on the second side frame 52 side and larger than the first top partial panel 11a. The first top partial panel 11a is attached to the first side panel 14 in a manner that allows it to be folded. The second top partial panel 11b is attached to the first top partial panel 11a in a manner that allows it to be folded.

[0038] (Front Panel) The front panel 12 is a heat insulating panel located on the front side (negative side in the Y direction) in the unfolded state (FIG. 1), and is arranged perpendicular (parallel to the ZX plane) to the horizontal plane (XY plane). This front panel 12 has a foldable structure, and has a first front partial panel 12a located on the first side frame 51 side, a second front partial panel 12b located in the middle, and a third front partial panel 12c located on the second side frame 52 side. Of these, the first front partial panel 12a is foldably attached to the first side panel 14. Also, the second front partial panel 12b is foldably attached to the first front partial panel 12a. Furthermore, the third front partial panel 12c is foldably attached to the second front partial panel 12b.

[0039] (Rear Panel) The rear panel 13 is a heat insulating panel located on the rear side (positive side in the Y direction) in the unfolded state (FIG. 1), and is disposed perpendicular (parallel to the ZX plane) to the horizontal plane (XY plane). The rear panel 13 has a foldable structure, and has a first rear partial panel 13a located on the first side frame 51 side, and a second rear partial panel 13b located on the second side frame 52 side. Of these, the second rear partial panel 13b is attached so as to be freely foldable relative to the first rear partial panel 13a. The first rear partial panel 13a is fixed to the first side panel 14.

[0040] (First side panel) The first side panel 14 is a heat-insulating panel located on the first side frame 51 side (negative side in the X direction) in both the unfolded state (FIG. 1) and the folded state (FIG. 3), and is disposed perpendicular (parallel to the YZ plane) to the horizontal plane (XY plane). This first side panel 14 is composed of a single plate-shaped member. In both the unfolded state (FIG. 1) and the folded state (FIG. 3), the first side panel 14 is disposed around the outer periphery of the first side frame 51 of the cart body 50 without moving, and is parallel to the YZ plane.

[0041] (2nd side panel) The second side panel 15 is a heat-insulating panel located on the second side frame 52 side (the positive side in the X direction) in both the unfolded state (FIG. 1) and the folded state (FIG. 3), and is disposed perpendicular (parallel to the YZ plane) to the horizontal plane (XY plane). This second side panel 15 is composed of a single plate-shaped member. In both the unfolded state (FIG. 1) and the folded state (FIG. 3), the second side panel 15 is disposed around the outer periphery of the second side frame 52 of the cart body 50 without moving, and is parallel to the YZ plane.

[0042] (Bottom Panel) The bottom panel 16 is a heat insulating panel located on the bottom side (negative side in the Z direction) in the unfolded state (FIG. 1), and is arranged parallel to the horizontal plane (XY plane). In the unfolded state, the bottom panel 16 is arranged on the bottom plate 58 of the dolly body 50, between the first side frame 51 and the second side frame 52. The bottom panel 16 is composed of a single plate-like member, and has a structure that can be folded by lifting it up. The bottom panel 16 is attached to the first side frame 51 so as to be freely foldable.

[0043] (Configuration of each insulation panel) The above-mentioned plurality of insulation panels 11-16 are vacuum insulation panels having vacuum insulation members including vacuum insulation material. However, in this embodiment, from the viewpoint of achieving both the insulation performance and convenience of the transport cart 10, all of the insulation panels 11-16 do not have to be vacuum insulation panels, and at least four of the insulation panels 11-16 may be vacuum insulation panels. Specifically, in order to prevent the risk of the vacuum insulation material being damaged by the weight of the luggage, the bottom panel 16 may not include vacuum insulation material, and in that case, for example, five insulation panels, namely the top panel 11, the front panel 12, the back panel 13, the first side panel 14, and the second side panel 15, may be vacuum insulation panels. In addition, in order to prevent the risk of the vacuum insulation material being damaged by opening and closing, insulation panels having an openable structure may not include vacuum insulation material. For example, the front panel 12 may be openable and closed, and four insulation panels, namely the top panel 11, the back panel 13, the first side panel 14, and the second side panel 15, may be vacuum insulation panels.

[0044] According to the present disclosure, a transport cart 10 can be provided that uses vacuum insulation material and has a ventilation rate below a specific value, and therefore has good insulation properties when in use and can be folded and nested when not in use. This will be described in detail below.

[0045] When vacuum insulation material is used as the insulation material for the insulation panels 11-16, a problem occurs in that the airtightness of the insulation container 30 is easily reduced due to the properties unique to the vacuum insulation material. That is, the vacuum insulation material has a property that the insulation property per unit thickness is about 5 to 10 times higher than that of a general foam insulation material, so that the desired insulation property can be obtained even if the thickness of the insulation material is significantly reduced. However, if the thickness of the insulation material is significantly reduced, the contact area between the end faces of the insulation panels 11-16 and the main surfaces of the insulation panels 11-16 also becomes significantly smaller, and as a result, the airtightness of the insulation container 30 is easily reduced.

[0046] In addition, the vacuum insulation material has a property of being poorly processable because it is necessary to maintain the inside in a vacuum state where the pressure is lower than atmospheric pressure. In addition, for example, in the case of a foam insulation material, even if a part of the foam insulation material is damaged, the deterioration of the insulation is limited to the damaged part, but in the case of a vacuum insulation material, if a part of the vacuum insulation material is damaged, the insulation of the entire vacuum insulation material will be reduced. In this way, the vacuum insulation material has a property of being significantly degraded in performance when damaged. Therefore, from the viewpoint of improving processability and preventing damage, a foam insulation material may be used together with the vacuum insulation material as an insulation panel. However, when multiple insulation materials are laminated, two contact surfaces are generated, namely, a contact surface between the end face of the vacuum insulation material and the main surface of the foam insulation material, and a contact surface between the end face of the foam insulation material and the main surface of the foam insulation material, and as a result, the airtightness of the insulation container 30 is likely to be reduced.

[0047] Furthermore, in the transport cart 10 according to this embodiment, the heat-insulating panels 11-16 are disposed on the cart body 50. In general, the cart body 50 tends to easily swing unstably during use. Specifically, the first side frame 51 and the second side frame 52 of the cart body 50 may swing, causing the distance between the upper part of the first side frame 51 and the upper part of the second side frame 52 to vary. For this reason, as the cart body 50 swings, the heat-insulating panels 11-16 or partial panels may shift at their joints, and as a result, the airtightness of the insulated container 30 is likely to decrease.

[0048] In this way, when vacuum insulation material is used as the insulation material of the insulation panels 11-16, the airtightness of the insulation container 30 is likely to decrease due to the specific properties of the vacuum insulation material (thin thickness, low workability, and large performance degradation when broken) and the property of being placed on the dolly body 50. Therefore, in the transport dolly 10 that is placed on the dolly body 50 and has the insulation panels 11-16 using vacuum insulation material, management of airtightness becomes important. However, in such a transport dolly 10, knowledge regarding the extent to which the airtightness of the insulation container 30 affects the insulation of the entire insulation container 30 has not been known in the past. In the present disclosure, the relationship between airtightness (air change rate) and cold retention time was studied in detail, and it was found that the decrease in the insulation of the insulation container 30 caused by airtightness can be suppressed by setting the air change rate to a predetermined value or less.

[0049] In addition, the above-mentioned technical idea of ​​managing airtightness is closely related to the problems specific to a transport cart that is arranged on the cart body and has an insulation panel using vacuum insulation material. For example, in the case of an insulation container that is not arranged on the cart body, the joints between the insulation panels will not shift due to the unstable rocking of the cart body, so even if a vacuum insulation material is used, there will be no airtightness problems due to being arranged on the cart body. On the other hand, even if the insulation panel of an insulation container arranged on the cart body does not use vacuum insulation material, if a general foam insulation material is used instead of vacuum insulation material, the general foam insulation material is sufficiently thick and has higher workability than vacuum insulation material, so that airtightness problems due to the insulation material are unlikely to occur. In addition, when a general foam insulation material is used, the performance of the insulation material is lower than that of vacuum insulation material, so in order to improve the insulation, it is often more appropriate to improve the performance of the insulation material. However, in the case of an insulation container having an insulation panel using vacuum insulation material, the performance of the insulation material is sufficiently excellent, so it is important to manage the airtightness and improve the insulation. In this way, the technical idea of ​​managing airtightness is closely related to the problem specific to a transport cart that is disposed on the cart body and has an insulation panel using vacuum insulation material. The insulation container 30 of the present disclosure will be described in more detail below.

[0050] (Ventilation rate) The ventilation rate of the insulated container 30 of the present disclosure is preferably 0.1 times / hr or less in the deployed state (assembled state). When the ventilation rate is 0.1 times / hr or less, the effect on the cold retention time of the heat transfer through gaps such as the joints between the insulating panels 11-16 is sufficiently small compared to the effect on the cold retention time of the heat transfer through the insulating panels 11-16, and the cold retention time is stable. In other words, a ventilation rate of 0.1 times / hr or less is important for suppressing the deterioration of the insulating properties of the insulated container 30 due to the deterioration of the airtightness and for fully demonstrating the insulating performance of the insulated container 30 using the vacuum insulating material. The ventilation rate is calculated as follows.

[0051] In other words, the ventilation rate (times / hr) of the insulated container is based on JIS A 1406:1974 (Indoor ventilation volume measurement method (carbon dioxide method)) and is the ventilation volume (also called the supply volume, m 3 / hr) and divide the ventilation volume Q by the volume of the insulated container. The ventilation volume is calculated by releasing carbon dioxide gas into the insulated container using a gas cylinder or vaporized dry ice, measuring the carbon dioxide gas concentration, and calculating it using formula (1) (Seidel's formula) described in 3.1 of the above JIS standard. The carbon dioxide gas concentration is measured using the infrared gas analyzer method described in 2.1(5) of the above JIS standard, with 3 to 5 measurement points at different heights in the insulated container, and the average value of the measurement points is the carbon dioxide gas concentration. In addition, based on the description in 2.2 of the above JIS standard, a small electric fan is used to stir the atmosphere in the insulated container at the time of the first carbon dioxide gas concentration measurement so that the concentration distribution is uniform. "Uniform concentration distribution" refers to a state in which the carbon dioxide gas concentration at each measurement point is within ±10% of the average value, and the atmosphere in the insulated container is stirred to achieve this state. In addition, the carbon dioxide gas concentration at the time of the first measurement is adjusted to be 5000 ppm or more and 10000 ppm or less. Furthermore, the ventilation volume is measured when there is no temperature difference between the inside and outside of the insulated container and when there is no wind. It is preferable to measure the ventilation volume multiple times (for example, 5 to 10 times) and calculate the average value.

[0052] In addition, the ventilation rate of the insulated container 30 of the present disclosure is preferably equal to or less than the value at which the rate of change in cold retention time in the common logarithm of the ventilation rate is -1 in the deployed state. This is because when the ventilation rate is equal to or less than the value at which the rate of change in cold retention time in the common logarithm of the ventilation rate is -1, the insulating performance of the insulating panels 11 to 16 can be fully exhibited. In other words, it is important for the insulating container using the vacuum insulating material to fully exhibit the insulating performance that the ventilation rate is equal to or less than the value at which the rate of change in cold retention time in the common logarithm of the ventilation rate is -1. The rate of change in cold retention time in the common logarithm of the ventilation rate is calculated as follows.

[0053] That is, the cooling time is evaluated based on the time (cooling time) that a sample (a 2-liter PET container filled with water at 2°C, equivalent to 10% of the volume of the insulated container) stored inside the insulated container can be kept at 8°C or less in an atmosphere with an outside air temperature of 35°C. First, the insulated container is placed in an atmosphere with an air temperature of 35°C, and the temperature inside and outside the insulated container is set to 35°C. Next, a PET container filled with water at 2°C, equivalent to 10% of the volume of the insulated container, is prepared as the sample to be stored. Note that a commercially available 2-liter PET container is used as the PET container. Next, the sample is placed in the center of the bottom panel of the insulated container. A hole is made in the cap of the PET container, and a thermocouple or resistance temperature detector with a length of about half the height of the PET container is introduced through the hole. This allows the temperature of the center part of the PET container to be measured. Next, the insulated container is sealed. Note that no cooling agent is used.

[0054] In this way, the cold insulation time can be obtained. On the other hand, when an insulating container having an openable structure is used, the degree of opening and closing can be adjusted to an intentionally irregular state, thereby experimentally adjusting the ventilation rate. Even when an insulating container having an openable structure is not used, the ventilation rate can be experimentally adjusted by, for example, adjusting the degree of joint between the insulating panels to an intentionally irregular state by inserting a hollow pipe between the joint between the insulating panels. Therefore, the relationship between the ventilation rate and the cold insulation time can be obtained by calculating the cold insulation time for each of the multiple ventilation rates experimentally adjusted. It is preferable that the measurement of the multiple ventilation rates is performed, for example, on a common logarithmic axis without bias in a range of the ventilation rate of 0.01 times / hr or more and 1 time / hr or less, and the measurement points of the multiple ventilation rates are, for example, 5 points or more, and may be 10 points or more.

[0055] After the relationship between the ventilation rate and the cooling time is obtained, the rate of change of the cooling time in the common logarithm of the ventilation rate is calculated. For example, a semi-logarithmic graph is created in which the ventilation rate is plotted on the horizontal logarithmic axis and the cooling time is plotted on the vertical normal axis, and the slope of the semi-logarithmic graph is calculated.

[0056] On the other hand, the ventilation rate of the insulated container 30 of the present disclosure is preferably 0.02 times / hr or more in the deployed state. By allowing a ventilation rate of 0.02 times / hr or more, it becomes easier to structure the joints between the insulating panels so that they can be easily joined or removed, and to structure the insulating container so that it can be opened and closed.

[0057] (Insulated container) As described above, at least four of the insulation panels 11-16 are vacuum insulation panels having vacuum insulation members including vacuum insulation material. Increasing the number of vacuum insulation panels improves the insulation performance of the insulation container 30. Reducing the number of vacuum insulation panels reduces the risk of the vacuum insulation material breaking and causing a sudden drop in the insulation performance of the insulation container 30.

[0058] In addition, examples of insulation panels other than vacuum insulation panels include insulation panels that do not include vacuum insulation material and have insulation members that include at least one of porous insulation material and fibrous insulation material. Note that porous insulation material and fibrous insulation material are insulation materials that have a large number of voids due to their porous structure or fibrous structure inside at atmospheric pressure. In the insulation container of the present disclosure, the thermal transmittance of insulation panels other than vacuum insulation panels is, for example, 3 W / m 2 K or less, and 2 W / m 2 It may be less than K.

[0059] (1) Vacuum insulation panel A vacuum insulation panel is an insulation panel having a vacuum insulation member including a vacuum insulation material. The vacuum insulation member may be a member having only the vacuum insulation material as an insulation material, or may be a member having the vacuum insulation material and other insulation materials. In the present disclosure, the vacuum insulation material may be referred to as a first insulation material, and an insulation material other than the vacuum insulation material may be referred to as a second insulation material.

[0060] (i) Vacuum insulation material The vacuum insulation material in the present disclosure has a core material and an exterior material that wraps the core material. FIG. 5 is a schematic cross-sectional view illustrating the vacuum insulation material in the present disclosure. As shown in FIG. 5(a), the first insulation material 41, which is a vacuum insulation material, has a core material 41a and an exterior material 41b having gas barrier properties. The inside of the exterior material 41b is in a reduced pressure state. FIG. 5(b) shows another example of the vacuum insulation material. In FIG. 5(a), voids are formed at both ends inside the first insulation material 41, which is a vacuum insulation material, but in FIG. 5(b), no voids are formed. The voids may or may not be formed depending on the manufacturing method of the first insulation material 41.

[0061] As the core material, for example, a powder, a porous body, a fibrous body, etc. can be used. The powder may be an inorganic powder or an organic powder, and specific examples thereof include dry silica, wet silica, agglomerated silica powder, conductive powder, calcium carbonate powder, perlite, clay, talc, etc. Examples of the porous body include urethane foam, styrene foam, phenol foam, etc. The fibrous body may be inorganic fiber or organic fiber, and examples of the inorganic fiber include glass fiber such as glass wool and glass fiber, alumina fiber, silica alumina fiber, silica fiber, ceramic fiber, rock wool, etc.

[0062] The exterior material is a member that covers the outer periphery of the core material, and examples thereof include a flexible sheet having a heat-sealing layer and a gas barrier layer in this order from the core material side. Examples of the gas barrier layer include metal foil and a vapor deposition sheet having a vapor deposition layer on one side of a resin sheet. Examples of the metal foil include aluminum. Examples of the vapor deposition layer include aluminum, aluminum oxide, and silicon oxide. Examples of the resin sheet include a known resin sheet.

[0063] The oxygen permeability of the exterior material is, for example, 0.5cc·m -2 ·day -1 It may be less than 0.1cc m -2 ·day -1 The water vapor permeability of the exterior material may be, for example, 0.2 cc·m -2 ·day -1 It may be less than 0.1cc m -2 ·day -1 The degree of internal vacuum of the vacuum insulation material may be, for example, 5 Pa or less. The initial thermal conductivity of the vacuum insulation material may be, for example, 15 mW m -1 ·K -1 Less than or equal to 10 mW m -1 ·K -1 may be less than 5 mW m -1 ·K -1 It may be the following.

[0064] (ii) Vacuum insulation material The vacuum insulation member in the present disclosure may be a member having only a vacuum insulation member (first insulation member) as the insulation member, or may be a member having a vacuum insulation member (first insulation member) and another insulation member (second insulation member). As described above, the vacuum insulation member (first insulation member) is subject to significant performance degradation when damaged, but by using the vacuum insulation member together with another insulation member (second insulation member), it is possible to suppress the deterioration of the insulation properties of the insulation panel when the vacuum insulation member (first insulation member) is damaged.

[0065] Fig. 6 is a schematic cross-sectional view illustrating a vacuum insulation member according to the present disclosure. As shown in Fig. 6(a), a vacuum insulation member 45A may have a first insulation material 41, which is a vacuum insulation material, and a second insulation material 42 located on one main surface side of the first insulation material 41. For example, the first insulation material 41 may be set in a mold, and then the first insulation material 41 and the second insulation material 42 may be integrally molded by injection molding. On the other hand, although not shown, an adhesive layer may be provided between the first insulation material 41 and the second insulation material 42 to bond them together.

[0066] Examples of the second insulating material include porous insulating materials such as foam insulating materials, and fibrous insulating materials. Examples of the porous insulating material and fibrous insulating material include foamed plastic insulating materials such as foamed polyethylene, foamed polypropylene, foamed polystyrene, foamed polyurethane, and foamed polyphenol, fiber insulating materials such as glass wool, glass fiber, rock wool, cellulose fiber, and insulation board, and natural material insulating materials such as wool and carbonized cork.

[0067] 6(a) does not have the second insulating material 42 on the end face of the first insulating material 41, but as shown in FIG. 6(b), the vacuum insulating member 45A may have the second insulating material 42 so as to cover both end faces of the first insulating material 41. Although not shown, only one end face of the first insulating material 41 may be covered with the second insulating material 42. Also, a part of the end face of the first insulating material 41 may be covered with the second insulating material 42, or the entire end face of the first insulating material 41 may be covered with the second insulating material 42.

[0068] 6(a) has the second insulating material 42 only on one main surface of the first insulating material 41, but the second insulating material 42 may be provided on both main surfaces of the first insulating material 41. Furthermore, as shown in FIG. 6(c), the vacuum insulating material 45A may have the second insulating material 42 so as to cover the entire periphery of the first insulating material 41.

[0069] Furthermore, the vacuum insulation component of the present disclosure may have a heat shielding sheet so as to cover the entire periphery of the first insulation material. For example, as shown in Fig. 6(d), the vacuum insulation component 45A may have a heat shielding sheet 43 so as to cover the entire periphery of the first insulation material 41 and the second insulation material 42. In this case, a part of the periphery of the first insulation material 41 is covered with the heat shielding sheet 43 via the second insulation material 42.

[0070] Examples of the heat shielding sheet include a multi-layer sheet containing metal foil and a vapor deposition sheet having a vapor deposition layer on one side of a resin sheet. The types of metal foil and vapor deposition sheet are the same as those described above. By providing a heat shielding sheet, the heat insulation of the heat insulating member is further improved. Furthermore, as described later, the airtightness of the heat insulating container can be improved.

[0071] (iii) Protective materials The vacuum insulation panel in the present disclosure is an insulation panel having at least the vacuum insulation member described above, and may further have a protective member for protecting the vacuum insulation member. FIG. 7 is a schematic cross-sectional view illustrating a vacuum insulation panel in the present disclosure. As shown in FIG. 7(a), the vacuum insulation panel 45 may have a vacuum insulation member 45A, an adhesive layer 44, and a protective member 45B in this order. The vacuum insulation panel 45 shown in FIG. 7(a) has a second insulation member 42 on one main surface side of the first insulation member 41, and a protective member 45B on the other main surface side of the first insulation member 41. On the other hand, as shown in FIG. 7(b), the vacuum insulation panel 45 may have a protective member 45B so as to cover the entire circumference of the vacuum insulation member 45A. Although not shown, the vacuum insulation panel may have the above-mentioned heat shielding sheet so as to cover the entire circumference of the protective member 45B shown in FIG. 7(b), for example.

[0072] Examples of the protective member include organic polymer members such as plywood, foam materials, resin boards, embossed resin sheets, and paperboards, and ceramic members. In addition, as a lightweight and relatively rigid material, for example, plastic cardboard and cured wood can be used. Alternatively, the same material as the above-mentioned second insulating material may be used.

[0073] (iv) Vacuum insulation panels The vacuum insulation panel of the present disclosure preferably has a low thermal transmission coefficient, for example, 0.5 W / m 2 It can be set to K or less.

[0074] Thermal conductivity is a value that indicates how easily heat is transmitted through an insulating panel, and the smaller the value, the higher the insulating properties. Thermal conductivity (U value) is expressed as follows: Heat transmission coefficient (W / m 2 K) = 1 / thermal resistance value (m 2 K / W) …(1) Thermal resistance value (m 2 K / W) = thickness (m) / thermal conductivity (W / mK) … (2)

[0075] Here, a method for measuring the thermal transmission coefficient of a thermal insulation panel will be described. For example, the thermal resistance value of the thermal insulation panel itself may be obtained (first measurement method). For example, a test thermal insulation panel having the same layer structure as the thermal insulation panel to be measured and a surface perpendicular to the thickness direction having a size of 30 cm x 30 cm or more may be prepared, and the thermal resistance value of the test thermal insulation panel may be obtained (second measurement method). For example, the thermal conductivity of each member constituting the thermal insulation panel to be measured may be measured, and the total thermal resistance value of each member may be obtained from the thickness and thermal conductivity of each member (third measurement method). The thermal resistance value and thermal conductivity are obtained in accordance with JIS A1412-1, 2, 3. The temperature of the measurement environment is 20°C or higher and 25°C or lower. It is preferable to first adopt the first measurement method, which is a direct measurement method, and if it is difficult to adopt the first measurement method, it is preferable to adopt the second measurement method, and if it is difficult to adopt the second measurement method, it is preferable to adopt the third measurement method. In addition, when the insulating panel has a plurality of regions with different thermal transmission coefficients, it is preferable to use an average thermal transmission coefficient taking into account the proportions occupied by the regions.

[0076] The third measurement method will now be exemplified. For example, assume that the vacuum insulation panel has a first insulation material (vacuum insulation material) and a second insulation material (EPP: expanded polypropylene). If the thermal conductivity of the first insulation material (vacuum insulation material) is 0.003 (W / mK) and the thickness is 0.006 m, the thermal resistance value is calculated from formula (2) as 0.006 / 0.003=2(m 2 On the other hand, if the thermal conductivity of the second insulation material (EPP) is 0.04 (W / mK) and its thickness is 0.02 m, the thermal resistance value is calculated from equation (2) as 0.02 / 0.04 = 1 / 2 (m 2 Therefore, the thermal transmittance of a vacuum insulation panel with a first insulation material and a second insulation material is 1 / (2+1 / 2)=0.4(W / m2) from formula (1). 2 K).

[0077] If the insulation container has multiple vacuum insulation panels, the average thermal transmittance of each vacuum insulation panel should be, for example, 0.5 W / m 2K or less. In addition, the thermal transmittance of all vacuum insulation panels can be set to, for example, 0.5 W / m 2 It can also be set to K or less.

[0078] The vacuum insulation panel may have a means for improving the insulation properties of the insulation panel. For example, as shown in FIG. 8(a), it is preferable that the first insulation material 41, which is a vacuum insulation material, is formed as a single piece so as to cover the entire area of ​​the vacuum insulation material in the width direction. For example, when the insulation container is made larger, one side of the insulation panel also becomes larger, but even in such a case, it is preferable that the first insulation material 41, which is a vacuum insulation material, is formed as a single piece. As shown in FIG. 8(a), when the width of the vacuum insulation material is set to W 1 The width of the first insulating material 41 is W 2 In this case, W 2 / W 1 The value of W is preferably, for example, 90% or more. 1 It is preferable that the value is, for example, 600 mm or more.

[0079] Also, for example, as shown in FIG. 8(b), when the vacuum insulation member 45A has a plurality of first insulation materials 41 in the width direction, the vacuum insulation member 45A may have an auxiliary insulation material 47 at a position corresponding to the gap portion α of the plurality of first insulation materials 41 in a plan view. By increasing the thickness of the vacuum insulation member in the gap portion α, the thermal insulation property of the vacuum insulation panel can be improved. Similarly, for example, as shown in FIG. 8(c), when the vacuum insulation member 45A has a plurality of first insulation materials 41 in the width direction, the vacuum insulation member 45A may have another first insulation material 41 at a position corresponding to the gap portion α of the plurality of first insulation materials 41 in a plan view. Since another first insulation material 41 is located in the gap portion α, the thermal insulation property of the vacuum insulation panel can be improved.

[0080] (2) Means for improving airtightness The insulated container of the present disclosure preferably has a ventilation rate in the deployed state of not more than a predetermined value. The means for reducing the ventilation rate of the insulated container (means for improving the airtightness of the insulated container) is not particularly limited as long as it is a means that can obtain a desired ventilation rate, and any means can be used.

[0081] An example of the airtightness improving means is a means for improving the airtightness of the joint between two heat insulating panels 11 to 16. For example, as shown in FIG. 9(a), in the heat insulating panels 11 to 16 to be joined, one heat insulating panel V 1 The second insulating material 42 is provided so as to cover the end face of the first insulating material 41, and the other insulating panel V 2 The insulating panel V has a second insulating material 42 so as to cover the main surface of the first insulating material 41. 1 The second insulating material 42 is located on the end surface of the first insulating material 41 in the insulating panel V 2 It is preferable that the second insulating materials 42 located on the main surface of the first insulating material 41 in the region X are in contact with each other. In Fig. 9(a) , by bringing the second insulating materials 42 into contact with each other in the region X, the airtightness in the region X is improved. Note that the two contacting second insulating materials may be insulating materials made of the same material or insulating materials made of different materials.

[0082] Also, for example, as shown in FIG. 9(b), in two joined insulation panels 11 to 16, one insulation panel V 1 The first insulating material 41 has a heat shield sheet 43 so as to cover the end face of the first insulating material 41 (through the second insulating material 42), and the other insulating panel V 2 The heat insulating panel V has a heat shielding sheet 43 so as to cover the main surface of the first heat insulating material 41 (through the second heat insulating material 42). 1 The heat shielding sheet 43 located on the end surface of the first heat insulating material 41 in the heat insulating panel V 2 It is preferable that the heat shielding sheet 43 located on the main surface of the first insulating material 41 in the region X is in contact with the heat shielding sheet 43 located on the main surface of the first insulating material 41 in the region X. In Fig. 9(b) , by bringing the heat shielding sheets 43 into contact with each other in the region X, the airtightness in the region X is improved. The two heat shielding sheets in contact may be sheets of the same material or sheets of different materials. Although not shown, the heat shielding sheet 43 and the second insulating material 42 may be in contact with each other in the region X.

[0083] Also, for example, as shown in FIG. 9(c), the insulating container 30 is provided with a hook-and-loop fastener member having a first hook-and-loop fastener portion 35a, a second hook-and-loop fastener portion 35b that can be coupled to the first hook-and-loop fastener portion 35a, and a flexible member 35c that is connected to the first hook-and-loop fastener portion 35a. In the two insulating panels 11 to 16 to be joined, a part of the flexible member 35c is formed on the insulating panel V. 1 The second hook-and-loop fastener portion 35b is fixed to the outer surface (the surface opposite to the insulating space) of the insulating panel V. 2 In FIG. 9(c), the insulating panel V 2 Since first hook-and-loop fastener portion 35a and second hook-and-loop fastener portion 35b can be joined at the outer surface of region X, airtightness in region X is improved.

[0084] Also, for example, as shown in FIG. 9(d), in two joined insulation panels 11 to 16, one insulation panel V 1 The first insulating material 41 has a first magnet 36a on its end surface, and the other insulating panel V 2 However, it is preferable that a second magnet 36b having a magnetic pole different from that of the first magnet 36a is provided on the end face of the first insulating material 41, and the first magnet 36a and the second magnet 36b attract each other by magnetic force in the deployed state. In Fig. 9(d), the magnetic force improves the airtightness in the region X.

[0085] (Modification) Next, modified examples of the transport cart will be described with reference to Figures 10 to 14. Figures 10 to 14 are diagrams showing modified examples of the transport cart. In Figures 10 to 14, the same parts as those shown in Figures 1 to 9 are given the same reference numerals and detailed explanations are omitted.

[0086] (Variation 1) 10(a) and 10(b) show a transport cart 10 according to the first modification. In FIG. 10(a) and 10(b), a heat-insulating container 30 formed in a box shape is mounted on a cart body 50, and the heat-insulating container 30 is located between a first side frame 51 and a second side frame 52. The heat-insulating container 30 may be detachably attached to the first side frame 51 and the second side frame 52 by a connecting member such as a hook-and-loop fastener (not shown). In this case, the front panel 12 of the heat-insulating container 30 is openable. As shown in FIG. 10(b), the front panel 12 is disposed around the first side frame 51 and the second side frame 52 in the folded state.

[0087] (Variation 2) Figures 11(a)-(c) show a transport cart 10 according to Modification 2. In the transport cart 10 shown in Figures 11(a)-(c), a box-shaped insulated container 30 is mounted on a cart body 50. As shown in Figure 11(c), the front panel 12 is placed on the top panel 11 in the folded state. The rest of the configuration is substantially similar to the transport cart 10 according to Modification 1 shown in Figures 10(a) and (b).

[0088] (Variation 3) FIG. 12 shows a transport cart 10 according to Modification 3. In the transport cart 10 shown in FIG. 12, a heat-insulating container 30 formed in a box shape is mounted on a cart body 50. In this case, the cart body 50 is a so-called cage cart, and has a first side frame 51A, a second side frame 52A, and a back frame 59 that connects the first side frame 51A and the second side frame 52A to each other on the back side. The first side frame 51A, the second side frame 52A, and the back frame 59 are each made of a metal lattice. The other configurations are substantially the same as those of the transport cart 10 according to Modification 1 shown in FIGS. 10(a) and (b).

[0089] (Variation 4) FIG. 13 shows a transport dolly 10 according to the fourth modification. In the transport dolly 10 shown in FIG. 13, a box-shaped insulated container 30 is mounted on a dolly body 50, and the insulated container 30 is located between a first side frame 51 and a second side frame 52. In this case, an exterior bag 38 is arranged so as to cover the top panel 11, the first side panel 14, the back panel 13, the second side panel 15, and the bottom panel 16 of the insulated container 30. The first side panel 14 and the second side panel 15 of the insulated container 30 are attached to the exterior bag 38 via appropriate attachment means, for example, hook-and-loop fasteners. The exterior bag 38 is made of a flexible material that is airtight and resistant to bending, and for example, an aluminum vapor deposition sheet can be used. By covering the top panel 11, the first side panel 14, the back panel 13, the second side panel 15, and the bottom panel 16 with the exterior bag 38, the panels are prevented from getting wet or scratched, and the product life can be extended. Furthermore, since the first side panel 14 and the second side panel 15 are attached to the outer bag 38, each insulating panel 11-16 and the outer bag 38 can be managed together, making it easy to prevent the insulating panels 11-16 from being lost.

[0090] (Variation 5) Fig. 14 shows a bogie body 50 according to the fifth modified example. In the bogie body 50 shown in Fig. 14, the first side frame 51 has a first metal part 60A located at the top, a second metal part 60B located at the bottom, and a heat insulating relay part 70 provided between the first metal part 60A and the second metal part 60B. Of these, the heat insulating relay part 70 has a resin block 78 that connects the first metal part 60A and the second metal part 60B. The configuration of the second side frame 52 may also be substantially the same as the configuration of the first side frame 51.

[0091] In this case, the first side frame 51 is not provided with the central connecting rod 54, and the mounting plate 67a is fixed onto the first wheel mounting frame 67. The resin block 78 is fixed to the first metal part 60A and the second metal part 60B by connectors 79 consisting of bolts 79a and nuts 79b. That is, a plurality of nuts 79b are embedded and fixed in the resin block 78. Then, the bolts 79a are screwed into the nuts 79b, respectively, to fix the resin block 78 to the first metal part 60A and the second metal part 60B.

[0092] The resin block 78 has a rectangular parallelepiped shape, and is made primarily of resin such as nylon, polypropylene, etc. The resin block 78 has high heat insulating properties, and heat conduction between the first metal portion 60A and the connecting member 53 is unlikely to occur.

[0093] The upper end of the resin block 78 is attached to the horizontal rail 56 located at the lowermost position (negative side in the Z direction) by a plurality of connectors 79. The upper end of the resin block 78 may be attached to any position of the first metal part 60A, and may be attached to another horizontal rail 56 or vertical rod 55, for example. The lower end of the resin block 78 is attached to the mounting plate 67a by a plurality of connectors 79, but this is not limited thereto, and may be attached directly to the first wheel mounting frame 67, for example. That is, the resin block 78 may directly connect the first metal part 60A and the first wheel mounting frame 67 without providing the mounting plate 67a. In this way, by providing the resin block 78 between the first metal part 60A and the second metal part 60B, it is possible to block the transfer of heat between the inside and the outside of the heat-insulating space (accommodating space) 20. This makes it possible to reduce the inflow of heat from the cart body 50 to the heat-insulating container 30. Furthermore, by using the resin block 78, the first metal portion 60A and the second metal portion 60B can be firmly connected over a wide area, so that a decrease in the strength of the first side frame 51 can be suppressed.

[0094] 14, both vertical rods 55 are perpendicular to the lowest horizontal rail 56. In this case, the resin block 78 may be attached to the entire length (Y direction) of the lowest horizontal rail 56. Also, by making the center frame 57 pass under the resin block 78, it is possible to prevent interference with other transport carts 10 during nesting.

[0095] (Experimental Example) A specific example of the heat-insulating container of the present disclosure was produced, and the ventilation rate and the cooling time were measured by the above-mentioned method. In this specific example, the heat-insulating container was a rectangular parallelepiped with inner dimensions of one side of 1010 mm in length x 1010 mm in width x 740 mm in height. In each vacuum insulation panel of the heat-insulating container, a 6 mm thick vacuum insulation material (glass wool as a core material, thermal conductivity 0.003 W / mK) was used as the first insulation material, a 15 mm thick foam insulation material (XPS: extruded urethane foam, thermal conductivity 0.036 W / mK) was used as the second insulation material, and a 1 mm thick plastic sheet with an aluminum deposition layer was used as a heat-shielding sheet covering the entire circumference of the first insulation material and the second insulation material. In addition, a 1 mm thick polyethylene sheet was used as a protective member, and aluminum was used as the vertical and horizontal frames of the heat-insulating container. The ventilation rate of the insulated container measured using the above-mentioned method was 0.034 times / hr, and the cooling time for 75.5 kg of water measured using the above-mentioned method was 13.6 hours, confirming that the insulated container exhibits good insulating properties.

[0096] (simulation) The relationship between the cooling time and the ventilation rate based on the simulation will be described below.

[0097] When the temperature outside the insulated container is high and the temperature inside the container is low, the amount of heat Q [J] flowing from the outside to the inside of the insulated container during a given time t [hr] can be expressed by the following equation (1). Q=(q A +q B )×t...Equation (1) Here, q A is the amount of heat per unit time [J / hr] flowing through the insulation panel that constitutes the insulation container, and qB is the amount of heat per unit time [J / hr] that flows in through gaps such as between the insulating panels of an insulated container.

[0098] The amount of heat per unit time that flows through the insulation panels that make up the insulated container, q A [J / hr] can be expressed by the following equation (2). q A =U×L×T×3600...Formula (2) Here, U is the thermal transmittance [W / m 2 K], and L is the surface area of ​​the inside of the insulated container [m 2 ] and T is the temperature difference between the inside and outside of the insulated container [K].

[0099] The amount of heat per unit time that flows in through gaps between the insulation panels of an insulated container, etc., q B [J / hr] can be expressed by the following equation (3). q B =D×V×a×C×T...Equation (3) Here, D is the ventilation rate [times / hr], and V is the internal volume of the insulated container [m 3 ], a is the environmental coefficient, and C is the heat capacity of the air [J / m 3 K], and T is the temperature difference between the inside and outside of the insulated container [K]. In this simulation, the environmental coefficient is 5.34, the specific heat capacity of air is 1.0 J / gK, and the density of air is 1.3 × 10 3 g / m 3 It was decided.

[0100] The environmental coefficient a is a multiplying factor to reflect the influence of environmental factors such as the temperature difference between the outside and inside of the insulated container and the wind speed outside the insulated container. This is because the movement of air flowing in through gaps between the insulating panels of the insulated container is influenced not only by factors of the insulated container itself such as the size and shape between the insulating panels, but also by environmental factors. The environmental coefficient a was determined by the following procedure. The insulated container was placed in a closed room without temperature control, and the normal ventilation rate of the insulated container was measured. The insulated container, with the inside kept at about 10°C with a cooling material placed inside, was set to 35°C to 40°C (humidity uncontrolled) and placed in an environmental test room with ventilation, and the ventilation rate of the environmental test of the insulated container was measured. The environmental coefficient was calculated by dividing the ventilation rate of the environmental test of the insulated container by the normal ventilation rate of the insulated container.

[0101] The insulated container is a cube with an inner dimension of 1 m on one side and an inner surface area L of 6 m, all of which are surrounded by insulating panels. 2 , internal volume V is 1m 3 The insulation panel has a three-layer structure consisting of extruded polystyrene foam (XPS, thermal conductivity 0.036 W / mK, thickness 15 mm), vacuum insulation material (thermal conductivity 0.003 W / mK, thickness 5 mm), and extruded polystyrene foam (XPS, thermal conductivity 0.036 W / mK, thickness 15 mm). The thermal conductivity U of this insulation panel is 0.4 (W / m 2 K).

[0102] The usage state of the insulated container was set to a state where 8 kg of cold insulation material (latent heat per unit weight: 320 kJ / kg) was placed inside the insulated container, and the insulated container was placed in an environment where the temperature difference between the inside and outside of the container was 30 K. This setting can be assumed to be, for example, a state where the inside of the insulated container is kept at a refrigerated temperature range (0°C to 5°C) by the cold insulation material during the Japanese summer (temperature 30°C to 35°C).

[0103] Based on the above, a simulation was performed on the relationship between the cooling time and the ventilation rate. The cooling time t [hr] was defined as the time it took for the amount of heat Q [J] flowing from the outside to the inside of the insulated container to reach the latent heat of the cooling material inside the insulated container, 2560 kJ. The ventilation rate was set on a logarithmic axis in the range of 0.001 times / hr to 10 times / hr without any bias, the cooling time was calculated for each ventilation rate set, and an approximation curve was obtained from the calculated values ​​using the least squares method.

[0104] FIG. 15 shows the results of a simulation in which the thickness of the vacuum insulation material is 5.0 mm. When the ventilation rate is 0.1 times / hr, a cooling time close to that when the ventilation rate is 0.001 times / hr (when the airtightness is extremely high) can be achieved. In contrast, when the ventilation rate is greater than 0.1 times / hr, the cooling time decreases significantly as the ventilation rate increases. In other words, when the ventilation rate is greater than 0.1 times / hr, slight fluctuations in the ventilation rate (airtightness) have a large effect on the cooling time, but when the ventilation rate is 0.1 times / hr or less, even if the ventilation rate (airtightness) fluctuates slightly, it has little effect on the cooling time, and the cooling time is stable. This tendency is not limited to the case where the thickness of the vacuum insulation material is 5.0 mm, but is similar when the thickness of the vacuum insulation material changes, as shown in FIG. 16. Other than changing the thickness of the vacuum insulation material, the simulation conditions were the same, and the results are for the following cases: a: 0.5 mm, b: 2.5 mm, c: 5.0 mm, d: 7.5 mm, e: 10.0 mm, and f: 12.5 mm.

[0105] The amount of heat Q flowing from the outside to the inside of an insulated container T is the amount of heat Q flowing through the insulation panels that make up the insulation container. A and the amount of heat Q flowing in through gaps between the insulation panels of the insulation container. B In order to stabilize the cooling time, Q B Q is the effect of A Q should be sufficiently smaller than the effect on cooling time. A Q is sufficiently smaller than the effect on cooling time B The value of Q A depends on the value of QA If the value of is large, it can be relatively large, and Q A Therefore, the use of vacuum insulation material reduces the Q A In the insulated container with a small value of Q B The value of must be made small accordingly, otherwise the cooling time will not be stable. The results of the above simulation show that an insulated container using vacuum insulation material can be fully utilized with an air change rate of 0.1 times / hr or less. In other words, it was confirmed that for an insulated container that can be switched between the unfolded and folded states and that uses vacuum insulation material, it is important to have an air change rate of 0.1 times / hr or less in order to prevent a decrease in the insulating properties of the insulated container due to airtightness.

[0106] On the other hand, in Fig. 15, when the ventilation rate was 0.02 times / hr, the cold retention time was almost the same as when the ventilation rate was 0.001 times / hr (when the airtightness was extremely high). This tendency was not limited to when the thickness of the vacuum insulation material was 5 mm, but was similar even when the thickness of the vacuum insulation material was changed, as shown in Fig. 16. In other words, it was suggested that when trying to improve the insulation of an insulated container, it is more effective to try to improve the insulation of the insulation panel than to lower the ventilation rate below 0.02 times / hr (rather than excessively increasing the airtightness).

[0107] Also, from the slopes of the curves in Figures 15 and 16, the rate of change in cold retention time in the common logarithm of the ventilation rate is calculated as shown in Figures 17 and 18. An insulated container with a ventilation rate that results in a rate of change in cold retention time in the common logarithm of the ventilation rate of -1 has a small rate of change in cold retention time in the common logarithm of the ventilation rate, so it can be said that the insulating performance of the insulating panel is being properly exhibited. Therefore, from the perspective of exhibiting the insulating properties of the insulating panel, it is preferable to set the ventilation rate at which the rate of change in cold retention time in the common logarithm of the ventilation rate of -1 as the upper limit of the ventilation rate for an insulating container equipped with that insulating panel.

[0108] Also, if we only consider the effect of airtightness, the thicker the vacuum insulation material, the lower the desired ventilation rate, and at first glance, it seems that the thicker the vacuum insulation material, the higher the airtightness required. However, in reality, the thicker the vacuum insulation material, the better the insulation of the insulation panel, and the better the insulation of the insulation container. For example, in this simulation, in FIG. 16, when the thickness of the vacuum insulation material is 12.5 mm and the ventilation rate is 0.1 times / hr, the cold retention time is 17 hours, which is longer than the cold retention time when the thickness of the vacuum insulation material is 10.0 mm and the ventilation rate is 0.001 times / hr. In this way, the thicker the vacuum insulation material, the more dominant the effect of the insulation of the insulation panel becomes, and the better the insulation of the insulation container becomes.

[0109] Table 1 shows the details of the relationship between ventilation rate and cooling time.

[0110] [Table 1]

[0111] The thickness of the vacuum insulation material correlates with the thermal conductivity of the insulation panel. If the thermal conductivity of the vacuum insulation material is the same, the thicker the vacuum insulation material is, the lower the thermal conductivity of the insulation panel will be. For example, in this simulation, the thermal conductivity of the insulation panel to obtain an insulated container with a cooling time of 7 hours or more is 0.5 W / m 2 It is below K.

[0112] (Relationship between insulation panel thickness, insulation container volume, and compactness index) The relationship between the thickness of the insulation panel, the volume of the insulation container, and the compactness index was evaluated. The external volume of the insulation container in the deployed state is V A The internal volume is V B In this case, the miniaturization index = (V A -V B ) / V A It is defined as:

[0113] For example, assuming a cube with a side length of 100 cm and an insulation panel thickness of 10 mm (1 cm), the external volume of the insulation container V A is 1m 3 (1000L). On the other hand, the internal volume of the insulated container is V B is (1.00-(0.01×2)) 3 =0.94m 3 (940L). Therefore, the size reduction index is 6%. In addition, except that the length of one side and the thickness of the insulation panel were changed to the values ​​shown in Table 2, the size reduction index was calculated in the same manner.

[0114] [Table 2]

[0115] As shown in Table 2, there is a correlation between the thickness of the insulation panel and the length of one side of the insulation container (the length of one side of the insulation panel). For example, (V A -V B ) / V A To achieve ≦1 / 3, it is necessary to use a thin insulation panel with a thickness of less than 70 mm (7 cm) when the length of one side of the insulation panel is 100 cm. In other words, to reduce the size of the insulation panel when not in use, the insulation panel thickness must be thin, but the insulation properties of the insulation panel tend to decrease when the insulation panel thickness is thin. Although it is possible to increase the insulation properties of the insulation panel by using a vacuum insulation material, as described above, when using a vacuum insulation material, the airtightness of the insulation container tends to decrease due to the unique properties of the vacuum insulation material (thin thickness, low workability, and large performance degradation when broken). Therefore, when trying to obtain an insulation container that can be reduced in size when not in use, it is necessary to pay more attention to airtightness.

[0116] It is also possible to combine the multiple components disclosed in the above embodiment and modified examples as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiment and modified examples. [Explanation of symbols]

[0117] 10 Transport trolley 11 Top Panel 12 Front Panel 13 Rear Panel 14 First side panel 15 Second side panel 16 Bottom Panel 30 Insulated container 50 Cart body 51 First side frame 52 Second side frame 58 Bottom plate

Claims

1. A transport cart, A carriage body having a pair of side frames and a connecting member connecting the pair of side frames to each other; a plurality of heat-insulating panels arranged in a box shape on the carriage body to form a heat-insulating container; The plurality of insulation panels include side insulation panels each arranged on the outer side of the side frames and a bottom insulation panel arranged on an upper portion of the connecting member, The transport cart, wherein the insulated container has an air circulation rate of 0.1 times / hr or less.

2. A transport cart, A carriage body having a pair of side frames and a connecting member connecting the pair of side frames to each other; a plurality of heat-insulating panels arranged in a box shape on the carriage body to form a heat-insulating container; The plurality of insulation panels include side insulation panels each arranged on the outer side of the side frames and a bottom insulation panel arranged on an upper portion of the connecting member, The insulated container is equal to or smaller than a value at which the rate of change in cold retention time in the common logarithm of the ventilation rate is -1, The cooling time is determined based on the internal volume of the insulated container. ３ When 8 kg of cooling material with a latent heat per unit weight of 320 kJ / kg is placed in the insulated container and the container is placed in an environment where the temperature difference between the inside and outside of the container is 30 K, the internal volume of the insulated container is 1 m ３ The time it takes for the amount of heat flowing from the outside to the inside of the insulated container to reach the latent heat of the ice pack inside the insulated container of 2,560 kJ per unit time.

3. A transport cart, A carriage body having a pair of side frames and a connecting member connecting the pair of side frames to each other; a plurality of heat-insulating panels arranged in a box shape on the carriage body to form a heat-insulating container; The plurality of insulation panels include side insulation panels each arranged on the outer side of the side frames and a bottom insulation panel arranged on an upper portion of the connecting member, The insulated container has a cooling time of 7 hours or more, The cooling time is determined based on the internal volume of the insulated container. ３ When 8 kg of cooling material with a latent heat per unit weight of 320 kJ / kg is placed in the insulated container and the container is placed in an environment where the temperature difference between the inside and outside of the container is 30 K, the internal volume of the insulated container is 1 m ３ The time it takes for the amount of heat flowing from the outside to the inside of the insulated container to reach the latent heat of the ice pack inside the insulated container of 2,560 kJ per unit time.

4. The internal volume of the insulated container is 0.2 m ３ The transport cart according to any one of claims 1 to 3, wherein:

5. The external volume of the insulated container is V Ａ The internal volume is V Ｂ In this case, (V Ａ -V Ｂ ) / V Ａ 5. The transport cart according to claim 1, wherein the value of is 1 / 3 or less.

6. 3. The transport cart according to claim 1, wherein the ventilation rate is 0.02 times / hr or more.

7. The average thermal conductivity of each of the insulation panels is 0.5 W / m ２ 7. The transport cart according to claim 1, wherein the weight of the cart is equal to or less than K.

8. The transport cart according to any one of claims 1 to 7, wherein the plurality of insulating panels can be in an expanded state in which the plurality of insulating panels are expanded into a box shape, and in a folded state in which the plurality of insulating panels are folded.

9. The transport cart of claim 8 , wherein the plurality of insulating panels are capable of being nested with other transport carts when in the folded state.

10. 10. A transport cart according to claim 1, wherein the plurality of insulating panels have at least a top panel, a front panel, a rear panel, and a pair of side panels, and the front panel is openable.

11. The transport cart according to claim 1 , wherein at least some of the plurality of insulating panels are fixed to the cart body.

12. The transport cart according to any one of claims 1 to 10, wherein the plurality of insulating panels are arranged in a box shape and removably attached to the cart body.

Images