Electric Field-Generating Container

The present invention effectively forms an electric field directed into the interior of an accommodation chamber of an electric field-generating container. An electric field-generating container includes a container casing and electrode members. The container casing includes an accommodation chamber that accommodates a stored product. The electrode members form an electric field in the accommodation chamber. The container casing includes a ceiling interior finishing panel made of electrical insulating resin. The ceiling interior finishing panel is provided as an indoor surface of the accommodation chamber. The electrode members are held on the ceiling interior finishing panel.

TECHNICAL FIELD

The present invention relates to an electric field-generating container.

BACKGROUND ART

An electric field-generating container such as a reefer container known in the art enables generation of an electric field in an accommodation chamber of the container (see, for example, PTL 1). The electric field formed in the accommodation chamber of the electric field-generating container helps maintain freshness of perishables, which may be herein referred to as stored products.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

Such an electric field-generating container includes an electrode plate on a ceiling surface of a container casing to form an electric field in an accommodation chamber accommodating stored products. The accommodation chamber typically includes, as a ceiling surface, a ceiling panel made of electrically conductive metal such as stainless steel. To form an electric field directed inward toward stored products in the accommodation chamber, the container preferably minimizes formation of an electric field directed outward toward the metallic ceiling panel that is at zero potential.

Solution to Problem

According to an aspect of the present invention, an electric field-generating container includes a container casing, a resin panel, and an electrode plate. The container casing includes an accommodation chamber that accommodates a stored product. The resin panel has electrical insulation properties and is provided as the whole or part of an indoor surface of the accommodation chamber. The electrode plate is adjacent to the resin panel and is capable of forming an electric field in the accommodation chamber.

DESCRIPTION OF EMBODIMENTS

Hereinafter, exemplary embodiments of the present invention will be described. It should be noted that embodiments described below do not unduly limit the present invention hereafter claimed, and that not all of the configurations in the following embodiments are required as means for solving the problems under the present invention.

With a door2eat the front of an electric field-generating container1, the right-and-left direction (i.e., the width direction), the up-and-down direction (i.e., the height direction), the fore-and-aft direction (i.e., the longitudinal direction) of the electric field-generating container1are hereinafter referred to as X, Z, and Y directions, respectively. The wording “first . . . ” and “second . . . ” used herein or in appended claims are intended to make different constituent components distinguishable from one another and are not intended to represent a specific order or relative superiority. Each of the drawings schematically illustrates a principal part of the device configuration of the electric field-generating container1for the purpose of facilitating the understanding.

In the following embodiments, the electric field-generating container1is described as an example of a container whose exterior dimensions, interior dimensions, and door opening are equivalent to those of 40-ft containers (40-ft high-cube reefer containers). Specifically, the exterior dimensions of the electric field-generating container1are as follows: the electric field-generating container1has a length of 12,192 mm (in the Y direction); a width of 2,438 mm (in the X direction); and a height of 2,896 mm (in the Z direction). In the accompanying drawings, the electric field-generating container1is not drawn to scale. The electric field-generating container1according to the present invention may also be implemented as a 20-ft container, a 40-ft non-high cube container, or a reefer container of any size.

The electric field-generating container1described in the following embodiments may be used for transportation (by sea, air, land, etc.) or may be permanently installed. The stored products in the electric field-generating container1may include: fresh food such as fishery products, produce (vegetables and fruits), and meat; flowers and ornamental plants; and other perishables, but are not limited thereto.

First Embodiment (FIGS.1to8)

The electric field-generating container1includes a container casing2and a reefer apparatus3. The container casing2is box-shaped and includes an accommodation chamber4.

The container casing2includes a ceiling portion2a,a pair of side wall portions2b,a front wall portion2c,a floor portion2d,and a door2e.The ceiling portion2a, the pair of side wall portions2b,the front wall portion2c,the floor portion2d,and the door2eeach include an exterior finishing panel, an interior finishing panel, and a heat insulator disposed between the exterior and interior finishing panels. This wall structure eliminates the susceptibility to the outside air temperature and enables the reefer apparatus3to maintain a predetermined temperature of the accommodation chamber4. The exterior finishing panels and the interior finishing panels except for a ceiling interior finishing panel2a3, which will be described later, are made of metallic materials.

The accommodation chamber4is formed by the interior finishing panels of the components such as the ceiling portion2a,the pair of side wall portions2b,the front wall portion2c,the floor portion2d,and the door2e,and front surfaces of these interior finishing panels constitute an indoor surface of the accommodation chamber4. The accommodation chamber4is formed as a space defined by the interior finishing panels of the components such as the ceiling portion2a,the pair of side wall portions2b,the front wall portion2c,the floor portion2d,and the door2e.The front wall portion2cincludes a front wall exterior finishing panel2c1, a front wall interior finishing panel2c2, a front wall heat insulator2c3, and the reefer apparatus3, which is securely installed in the front wall portion2c.

The reefer apparatus3serves as a temperature-adjusting apparatus and a cooling apparatus. As illustrated inFIG.1, the reefer apparatus3includes a casing3c, which includes a suction portion3aand an air outlet3b. Air (cold air) in the accommodation chamber4is sucked in through the suction portion3a,and cold air is blown into the accommodation chamber4through the air outlet3b.The cold air blown into the accommodation chamber4through the air outlet3bis guided to the door2ethrough floor surface ventilation paths2d1, each of which is groove-shaped and formed between T rails constituting the floor portion2d. The cold air flows upward along the door2eand reaches a ceiling surface2a1of the ceiling portion2a.The cold air then flows along the ceiling surface2a1toward the front and is sucked into the suction portion3aof the reefer apparatus3. That is, cold air circulates around the accommodation chamber4as denoted by an arrow with a dash-dot-dot line inFIG.1.

The ceiling portion2aof the container casing2includes a ceiling exterior finishing panel2a2, the ceiling interior finishing panel2a3, and a ceiling heat insulator2a4(seeFIG.3). The ceiling exterior finishing panel2a2may be made of a metallic material such as an iron plate. The side wall portions2b,the front wall portion2c,the floor portion2d,and the door2emay each include an exterior finishing panel made of a metallic material such as an iron plate and an interior finishing panel made of a metallic material such as stainless steel. The ceiling exterior finishing panel2a2is provided with exterior finishing panel-reinforcing members (not illustrated) that are fixed, by spot welding, to a surface adjoining the ceiling heat insulator2a4. The exterior finishing panel-reinforcing members are made of metal. The exterior finishing panel-reinforcing members extend in the width direction of the ceiling exterior finishing panel2a2(i.e., in the X direction) and are arranged in parallel in the longitudinal direction of the ceiling exterior finishing panel2a2(i.e., in the Y direction). The exterior finishing panel-reinforcing members are embedded in the ceiling heat insulator2a4and are discretely located away from the ceiling interior finishing panel2a3. As with reinforcing members2a5, which will be described later, the exterior finishing panel-reinforcing members may be made of a resinous material.

The ceiling interior finishing panel2a3is a resin panel made entirely of electrical insulating resin. That is, the ceiling interior finishing panel2a3is one form of a resin panel (i.e., an interior finishing panel made of resin) of the present invention. The electrical insulating resin to be used may be a fiber reinforced plastic (FRP) material; that is, the ceiling interior finishing panel2a3is a molded panel made of the RFP material. The molded panel in the present embodiment is a single panel. Fiber reinforced plastics are highly insulative, have low thermal expansion coefficients, may be formed into a large panel-like object, and are thus preferred as the ceiling interior finishing panel2a3. Fiber reinforced plastics allow an electric field to pass therethrough and are thus also preferred as the reinforcing members2a5, which do not affect the forming of an electric field by electrode plates7accordingly. An electric insulating filler such as glass fiber is added to the FRP resin.

As illustrated inFIG.2, the reinforcing members2a5are fastened to an inner surface (i.e., a facing surface) being one of the surfaces of the ceiling interior finishing panel2a3and facing the ceiling exterior finishing panel2a2. The reinforcing members2a5increase the stiffness of the ceiling interior finishing panel2a3made of the FRP material. To that end, the reinforcing members2a5extend in the width direction of the ceiling interior finishing panel2a3(i.e., in the X direction). The reinforcing members2a5may also be provided on an inner surface being one of the surfaces of the ceiling exterior finishing panel2a2and facing the ceiling interior finishing panel2a3, as mentioned above. The reinforcing members2a5each having a height corresponding to the spacing between the ceiling exterior finishing panel2a2and the ceiling interior finishing panel2a3may be provided as spacers fastened therebetween. The ceiling portion2amay thus be entirely reinforced to a greater extent. The reinforcing members2a5are molded articles made of an FRP material, the reason for which is as described above with regard to the ceiling interior finishing panel2a3. The reinforcing members2a5may each have a shape of, for example, a cylinder and more preferably have a shape of a rectangular prism.

The ceiling surface2a1of the accommodation chamber4is provided with electrode members5. Referring toFIG.2, the electric field-generating container1includes a plurality of electrode members5, or more specifically,12electrode members5. Each electrode member5is rod-like throughout its entire length. The electrode members5are located away from each other and are arranged in parallel in the width direction of the container casing2(i.e., in the X direction or in the crossing direction), with the longitudinal direction of each electrode member5coinciding with the longitudinal direction of the container casing2(i.e., the Y direction). This arrangement enables a shortening of the individual electrode members5(i.e., electrode-housing members6and the electrode plates7), and ease of production and handleability may be achieved accordingly.

The electrode members5include their respective electrode-housing members6and their respective electrode plates7. The electrode plates7generate an electric field through the application of high voltage.

Each of the electrode-housing members6is one form of a holding member of the present invention. The electrode-housing members6are made of electrical insulating resin. Specifically, the electrode-housing members6in the present embodiment are made of rigid polyvinyl chloride (PVC). Rigid PVC has flame retardancy, heat-resisting properties, and a brittle temperature that render it suited for use as containers. In view of the fact that the electric field-generating container1has the function of generating an electric field, rigid PVC is particularly suited for formation of an electric field in the accommodation chamber4because of its excellent electrical insulation properties and its high dielectric constant, which promote transmission of an electric field generated by the electrode plates7.

Each electrode-housing member6is a flat tubular member and includes a main body part6aand end caps6b. The main body part6ahas a tubular shape and accommodates the electrode plate7. As illustrated inFIG.4, the main body part6aincludes a top face portion6a1(i.e., an attachment portion), a pair of side face portions6a2, and a bottom face portion6a3. Flange portions6a4are provided on the respective side faces extending in the longitudinal direction of the top face portion6a1and protrude from the side face portions6a2. Each flange portion6a4has through-holes (not illustrated) aligned in the longitudinal direction of the flange portion6a4, and fasteners6c(e.g., screws or rivets) are inserted into the respective through-holes for fastening to the ceiling surface2a1. Each end cap6bseals the corresponding end of the main body part6aand has through-holes (not illustrated) into which the fasteners6care inserted for fastening to the ceiling surface2a1.

Each electrode-housing member6is shorter than the width of the ceiling surface2a1of the container casing2in the X direction. Each electrode plate7and the corresponding main body part6aare of the same length. The electrode plate7is thus capable of generating an electric field substantially along the entire length of the electrode-housing member6.

Each electrode-housing member6is a single tube having a wall with no holes throughout its entire length. Each electrode plate7is covered with the corresponding electrode-housing member6along its entire length and is not exposed to view in the accommodation chamber4. In this way, stored products (e.g., freight) in the accommodation chamber4are kept from direct contact with the electrode plates7for safety. The electrode plates7are also kept from dust and are thus maintained in a safe state when being energized with high voltage. The electrode plates7are safely protected from getting wet during cleanup of the interior of the accommodation chamber4. The avoidance of moisture protects the electrode plates7from, for example, rust, which would otherwise cause corrosion of the electrode plates7and would eventually compromise electrical continuity of the electrode plates7and formation of an electric field. The accommodation chamber4may be easily cleaned up without extra caution taken as to the electrode plates7.

End portions of each electrode-housing member6are maintained liquid-tight by the end caps6b.Specifically, the main body part6aand each of the end caps6bare disposed with a waterproofing part (not illustrated) therebetween. The electrode plate7is thus sealed liquid-tight in the electrode-housing member6. This eliminates the possibility that the stored products will come into contact with the electrode plates7through the ends of the electrode-housing members6. The electrode-housing members6will be kept from dust and will also be prevented from getting wet during cleanup.

As illustrated inFIG.4, each electrode-housing member6has an electrode plate housing6a5, which accommodates the corresponding electrode plate7. The electrode plate housing6a5and the electrode plate7are of the same length and width. The electrode plate housing6a5is formed as a space whose height is greater than the thickness of the electrode plate7. The electrode plate housing6a5in the present embodiment includes an insulation cavity6a6, which is provided on the electrode plate7.

The insulation cavity6a6is technically significant as an insulation cavity that electrically isolates the electrode plate7from the ceiling exterior finishing panel2a2located above the electrode plate7and made of metal. The insulation cavity6a6in the electrode-housing member6provides a high-insulation air space within the electrode-housing member6. The air space (i.e., the insulation cavity6a6) helps minimize formation of an electric field extending from the electrode plate7and directed toward the ceiling exterior finishing panel2a2that is made of metal and is at ground potential (i.e., at zero potential). This facilitates the formation of an electric field extending from the electrode plates7into the accommodation chamber4. The electric field in the accommodation chamber4may thus be formed in an efficient and effective manner.

The electrode plates7are conductive plates such as aluminum plates. The electrode plates7each have a shape of a flat plate, or more specifically, a shape of a strip. Each electrode plate7and the corresponding main body part6aare substantially of the same length. The electrode plate7is thus capable of forming an electric field in the longitudinal direction of the main body part6a.The electrode plates7are arranged in a matrix extending from the door2eside and ending short of the front wall portion2c.This arrangement enables the electrode plates7to form an electric field throughout the accommodation chamber4. In the present embodiment, 12 electrode plates7(i.e., 12 electrode members5) are arranged. In some modifications of the present embodiment, the number of electrode plates7(i.e., the number of electrode members5) may be not more than 11 or not less than 13. Each electrode plate7is a single plate, and the number of components may thus be less than would be the case where each electrode plate7is composed of plate parts. Alternatively, each electrode plate7may be composed of conductive plates connected to each other in a manner so as to enable conduction of electricity.

Each electrode plate7is provided with a press member8, which is disposed thereon (seeFIG.4). The press member8is a leaf spring. The press member8is disposed in the electrode plate housing6a5and exerts bias force on the electrode plate7in a manner so as to move the electrode plate7away from the ceiling surface2a1. The electrode plate7is kept pressed against the bottom face portion6a3, which is an inner face of the electrode plate housing6a5. The electrode plate7may be kept immovable in the electrode plate housing6a5having the insulation cavity6a6. The press members8are made of electrical insulating resin. As in the case of the electrode-housing members6mentioned above, rigid PVC may be used for molding of the press members8to take advantage of, for example, its excellent electrical insulation properties and its high dielectric constant, which promote transmission of an electric field generated by the electrode plates7.

Each of the electrode members5described so far is rod-like throughout its entire length. The fasteners6cfor fastening to the ceiling portion2amay be inserted into the through-holes of the main body part6aand into the through-holes of the end caps6bto fix the electrode member5to ceiling surface2a1. This facilitates the fixation of the electrode members5.

The electrode members5are thin in profile and achieve a reduction in the degree of prominence on the ceiling surface2a1accordingly. The main body part6aof the electrode-housing member6has, for example, a height of 22 mm and a width of 135 mm; that is, t1inFIG.4is 22 mm, and the width of the top face portion6a1including the flange portions6a4(i.e., the width of the mounting surface of the electrode-housing member6on the ceiling surface2a1) is 135 mm. Each end cap6bhas, for example, a height of 25 mm and a width of 135 mm; that is, the dimension corresponding to the height of the main body part6ais 25 mm, and each end cap6band the main body part6aare of the same width. Each electrode plate7has, for example, a width of 80 mm and a thickness of 3 mm. Each electrode member5as a whole may have a low-profile, flat shape accordingly. With the electrode members5having such a geometry, the interior height of the accommodation chamber4may be reduced correspondingly; that is, the electrode members5may be installed with a minimum reduction in carrying capacity (internal capacity). The aforementioned values are merely example values. Needless to say, the dimensions may be changed. The prominence formed by the electrode member5on ceiling surface2a1is preferably not more than 30 mm, more preferably not more than 25 mm, still more preferably not more than 20 mm, particularly preferably not more than 15 mm, and more particularly preferably not more than 10 mm.

The individual electrode plates7are connected to an electric field generation controller3jvia conduction paths9(i.e., wiring) and a high-tension wire3j14. The conduction paths9(i.e., wiring) each include main wires9a,branch wires9b,and branch connectors9c.The conduction paths9are omitted fromFIG.4. The electrode plates7are connected in parallel to the reefer apparatus3. If conduction in any one of the electrode plates7(i.e., in any one of the electrode members5) ceases due to, for example, breakage, this arrangement would ensure continued conduction in the other electrode plates7. Furthermore, there is no problem with the branch connectors9cgetting wet because the branch connector9care waterproof connectors. Aqueous cleaning of the accommodation chamber4may thus be performed.

The reefer apparatus3according to an embodiment is a unit apparatus designed for installation on the container casing2. The reefer apparatus3is bolted to the front wall portion2cof the container casing2. The reefer apparatus3is driven when being connected to a power cable of a power supply system (i.e., an external power source) such as a power supply box or a container stand installed in a container terminal or in a container ship. Upon application of power by the reefer apparatus3, the electric field generation controller3j,which will be described later, goes into action to energize the electrode plates7with high voltage. The reefer apparatus3includes the casing3c.The casing3cincludes a frame body3c1and a reefer cabinet3c2. The frame body3c1includes an upper section, a middle section, and a lower section. The middle section and the lower section are located on the front side of the reefer cabinet3c2.

The upper section has two hatches3d.The hatches3dare openable for access to the inside of the reefer cabinet3c2. The middle section is provided with a partition shelf3e,which is a partition between the middle section and the lower section. Devices placed on the partition shelf3eincludes a condenser3fand an operation device3g,which is operable for adjustment of the temperature of the accommodation chamber4. The operation device3gincludes a display screen3g1and an operation element3g2.

The lower section accommodates a compressor compartment3h,an inverter device3i,and the electric field generation controller3j.The electric field generation controller3jand the inverter device3iface a protective panel3k,which is located in front of them and made of metal. The top of the protective panel3kis located below an upper hatch3j3, which is part of the electric field generation controller3jand will be described later. This is advantageous in that the opening of the upper hatch3j3alone, without the protective panel3kbecoming a hindrance thereto, makes the operation device3gavailable for user manipulation.

The protective panel3kand the inverter device3iare disposed with a clearance therebetween. The clearance provides a power cable-housing portion for receiving a power cable3m(seeFIG.3). The power cable3mis composed of a power plug3m1and a cable3m2. The cable3m2is connected to the reefer apparatus3. Connecting the power cable3mto a power cable of a power supply system such as a power supply box or a container stand installed in a container terminal or in a container ship enables supply of external electric power to the reefer apparatus3.

In terms of functionality, temperature-adjusting devices such as the condenser3f,the operation device3g, the compressor compartment3h,and the inverter device3iconstitute a cooling unit (cooling apparatus)3A, and the electric field generation controller3jhaving a function associated with an electric field is an electric field generation control unit3B. The reefer apparatus3is an electric field temperature control unit that is a combination of the cooling unit3A and the electric field generation control unit3B.

Electric Field Generation Controller3j(FIGS.6,7, and8)

The electric field generation controller3jis incorporated in the reefer apparatus3. The electric field generation controller3jincludes a cabinet3j1. The cabinet3j1has the upper hatch3j3(a first hatch) and a lower hatch3j4(a second hatch), which are hatches with which a front opening of a main body3j2is closed.

The upper hatch3j3is provided for opening and closing of an upper housing portion3j5(i.e., a first housing portion) of the main body3j2. When being closed, the hatch3j3keeps the upper housing portion3j5sealed liquid-tight. The upper hatch3j3has a window3j7, through which a display screen3j81is visible from outside the upper hatch3j3.

The lower hatch3j4is provided for opening and closing of a lower housing portion3j6(i.e., a second housing portion) of the main body3j2. When being closed, the hatch3j4keeps the lower housing portion3j6sealed liquid-tight. Opening the lower hatch3j4involves the removal of the protective panel3kfacing the lower hatch3j4. The extra effort required to open the lower hatch3j4is conducive to the protection of a high-voltage power supply being an electric field emission source installed in the lower housing portion3j6and to the maintenance of safety.

The upper housing portion3j5accommodates an operation display device3j8, a transformer (not illustrated), and a first mechanical part3j9. The display screen3j81is provided on the operation display device3j8. The first mechanical part3j9includes mainly a PLC, a power supply device, and a breaker device. The operation display device3j8is operable for controlling various operating statuses of the electric field generation controller3j.As mentioned above, the protective panel3kwill not become a hindrance to the opening of the upper hatch3j3. This provides ease of use; that is, the opening of the upper hatch3j3alone makes the operation display device3j8available for user manipulation.

The lower housing portion3j6accommodates a second mechanical part3j10and a third mechanical part3j11. The second mechanical part3j10includes mainly relays, a fan motor, and a heater. The third mechanical part3j11includes mainly various types of terminal blocks and the high-voltage power supply.

The electric field generation controller3jis powered and driven by the reefer apparatus3. For reception of power, the cabinet3j1of the electric field generation controller3jis provided with a power supply connection portion3j13, which is on a side face of the cabinet3j1. The power supply connection portion3j13is provided for connection to one end of a power line3j12, the other end of which is connected to the reefer apparatus3.

Power transmitted through the power line3j12is fed into the first mechanical part3j9, where the power supply device drives the PLC accordingly. The voltage of power supply transmitted through the power line3j12is increased by the transformer, and the resulting high voltage power is fed into the high-voltage power supply included in the third mechanical part3j11. The high-voltage power supply applies the high voltage to the electrode plates7through the conduction paths9. For application of high voltage, the cabinet3j1of the electric field generation controller3jis provided with a high-tension wire connection portion3j15, which is on the side face of the cabinet3j1. The high-tension wire connection portion3j15is provided for connection to one end of the high-tension wire3j14, the other end of which is connected to the conduction paths9.

The high-tension wire3j14is led into the reefer cabinet3c2through an insertion hole3c5in a front plate3c4. As denoted by a dash-dot-dot line inFIG.6, the high-tension wire3j14is routed through the reefer cabinet3c2and is connected to the conduction paths9through a connector (not illustrated) in a box-shaped, enclosed space that is defined by the reefer cabinet3c2and located behind the front plate3c4(i.e., located close to the accommodation chamber4).

The conduction paths9extend out from the upper part of the reefer cabinet3c2and are led into the accommodation chamber4, where the conduction paths9are connected to the electrode plates7.

These various types of devices required to transform the power of the reefer apparatus3into a high voltage and to apply the resulting high voltage to the electrode plates7through the conduction paths9are all packaged in a single cabinet, namely, the cabinet3j1of the electric field generation controller3j.The compact design of the electric field generation controller3jenables it to be installed easily in the frame body3c1of the reefer apparatus3.

In addition to the power supply connection portion3j13and the high-tension wire connection portion3j15, a signal line connection portion (not illustrated) for connection to a sensor that senses the opening and closing of the door2eis provided on the side face of the cabinet3j1. Control is exercised in such a manner that the application of high voltage to the electrode plates7is stopped when the door2eis closed.

The cabinet3j1is a dustproof, waterproof cabinet having dust and water resistance with IP54rating. The upper hatch3j3, the lower hatch3j4, and the main body3j2adjoin each other with a dust- and waterproofing sealing portion (not illustrated) therebetween. The power supply connection portion3j13, the high-tension wire connection portion3j15, and the signal line connection portion are each placed on a dust- and waterproofing grommet3j16. The cabinet3j1is protected against intrusion of dust and water droplets accordingly. This enables the electric field generation controller3jto offer added safety.

The cabinet3j1is provided with first vibration-isolating support feet3j17and second vibration-isolating support feet3j18, each of which is attached to a left-hand or right-hand side face of the cabinet3j1. The vibration-isolating support feet have the same structure. The first vibration-isolating support feet3j17are arranged in the depth direction of the cabinet3j1and are fastened to a lower frame plate3c3of the frame body3c1of the reefer apparatus3. The second vibration-isolating support feet3j18are arranged in the height direction of the cabinet3j1and are fastened to the front plate3c4of the reefer cabinet3c2of the reefer apparatus3. The electric field generation controller3jis disposed with a clearance from the lower frame plate3c3and with a clearance from the front plate3c4.

The first vibration-isolating support feet3j17and the second vibration-isolating support feet3j18are each provided with a rubber foot3j19, which is a rubbery elastic body. The rubber feet3j19are elastically deformable to allow displacement of the electric field generation controller3jfrom the frame body3c1being part of the reefer apparatus3and securely installed in the container casing2. The container casing2may undergo vibration or impact when the electric field-generating container1is carried by a crane. Similarly, the container casing2may undergo vibration or impact when the electric field-generating container1is on a container ship underway or stays stationary in, for example, a container yard. Under these circumstances, the electric field generation controller3jis protected in such a manner that the rubber feet3j19, which are elastically deformable to allow displacement of the electric field generation controller3jfrom the frame body3c1of the reefer apparatus3, dampen vibration or impact on the constituent mechanical components of the electric field generation controller3j.

Advantageous Effects of Embodiment

The following describes some of the advantageous effects that may be produced by the electric field-generating container1.

The electric field-generating container1includes the ceiling interior finishing panel2a3(i.e., the resin panel) that has electrical insulation properties and is provided as the ceiling surface2a1of the accommodation chamber4(i.e., as the indoor surface of the accommodation chamber4). If the ceiling interior finishing panel2a3is a metallic panel, an electric field extending from the electrode plates7and directed toward the metallic plate that is at zero potential is likely to be formed, with a weakening of an electric field extending into the accommodation chamber4. As a workaround to the weakening of the electric field, the electrode plates7may be disposed as far away from the metallic plate (i.e., from the ceiling interior finishing panel) as possible so as to minimize the formation of an electric field directed to the metallic panel. However, this may cause an increase in the degree of prominence of the electrode plates7(i.e., the electrode members5) on the metallic panel (i.e., on the ceiling surface) in the interior of the accommodation chamber4, whose carrying capacity would be reduced accordingly. The electric field-generating container1includes the ceiling interior finishing panel2a3that is made of electrical insulating resin and is provided as the ceiling surface2a1of the accommodation chamber4. This eliminates the need to dispose the electrode plates7(i.e., the electrode members5) deep into the interior, away from the ceiling interior finishing panel2a3. The electrode members5in the present embodiment may thus be fixed to the ceiling interior finishing panel2a3. In this way, the electric field-generating container1achieves a reduction in the degree of prominence of the electrode members5in the accommodation chamber4; that is, the electrode member5may be fixed to the ceiling portion2awith a minimum reduction in the carrying capacity (internal capacity) of the accommodation chamber4.

The ceiling interior finishing panel2a3that is a resin panel is provided as the whole of the ceiling surface2a1of the accommodation chamber4. This means that every part of the ceiling surface2a1is not at zero potential, and an electric field extending from the electrode plates7into the accommodation chamber4may be formed all over the ceiling surface2a1. The electrode members5(i.e., the electrode plates7) may be disposed in any location on the ceiling surface2a1.

The electric field-generating container1includes the electrode-housing members6(i.e., the holding members) having electrical insulation properties and each including the electrode plate housing6a5that has a flat shape to accommodate the corresponding electrode plate7. The electrode-housing members6may thus be thin in profile, and a reduction in the degree of prominence of the electrode-housing members6on the ceiling surface2a1in the accommodation chamber4may be achieved accordingly.

The electrode-housing members6(i.e., the holding members) of the electric field-generating container1are fixed directly to the ceiling interior finishing panel2a3(i.e., to the resin plate). This enables a reduction in the degree of prominence of the electrode-housing members6on the ceiling surface2a1in the accommodation chamber4.

FIG.12is a perspective view of part of an electric field-generating container according to a technique known in the art. Referring toFIG.12, the electric field-generating container according to the technique known in the art includes a container casing21, in which a reefer apparatus22is placed. The container casing21is provided with a support frame23, which extends outward from an end portion of the container casing21. An electric field generation controller24is placed on the support frame23. The support frame23extending outward from the container casing21has a length L, which is the amount by which the overall length of the container casing21needs to be reduced. As a result, the carrying capacity of the container casing21of the electric field-generating container known in the art is reduced. As a workaround to this problem, the electric field-generating container1includes the reefer apparatus3in which the electric field generation controller3jis incorporated. More specifically, the electric field generation controller3jis accommodated in the casing3cof the reefer apparatus3. This eliminates the need for the support frame23extending outward from the container casing21of the electric field-generating container according to the technique known in the art and enables the installation of electric field generation controller3jwithout involving a reduction in the carrying capacity of the accommodation chamber4.

The electric field generation controller3jincludes the cabinet3j1, the power supply connection portion3j13, and the high-tension wire connection portion3j15. The power supply connection portion3j13is provided on the cabinet3j1and is connectable to the power line3j12through which the electric field generation controller3jis supplied with drive power from the reefer apparatus3. The high-tension wire connection portion3j15is provided on the cabinet3j1and is connectable to the high-tension wire3j14connected to the electrode plates7. Each of the power supply connection portion3j13and the high-tension wire connection portion3j15on the cabinet3j1allows easy connection and disconnection of the corresponding one of the power line3j12and the high-tension wire3j14.

The electric field generation controller3jincludes the operation display device3j8that displays the display screen3j81(i.e., an operation screen). The cabinet3j1includes the upper hatch3j3and the lower hatch3j4. The upper hatch3j3has the window3j7facing at least the display screen3j81. The operation display device3j8may thus be protected by the upper hatch3j3. The display screen3j81is visible through the window3j7with the upper hatch3j3closed. The upper hatch3j3is openable independently of the lower hatch3j4, and the possibility of inadvertent opening of the lower housing portion3j6is minimized accordingly.

Modifications of First Embodiment

The electrode members5in the present embodiment each have the insulation cavity6a6provided on the electrode plate7in the electrode plate housing6a5of the electrode-housing member6. An alternative to the electrode member5may be an electrode member5A, which does not have the insulation cavity6a6as illustrated inFIG.5A. The height of the electrode plate housing6a5of the electrode member5A is about the same as the height of the electrode plate7. A further reduction in the height of the electrode member5A may be achieved. The electrode plate7and the electrode-housing member6of the electrode member5A may be integrally molded by insert molding. The electrode plate housing6a5may have, on its faces facing the electrode plate7, small projections to press and hold the electrode plate7. Each of the small projections is one form of a press member of the present invention.

Referring toFIG.5B, an electrode member5B includes, in the electrode plate housing6a5of the electrode-housing member6, the electrode plate7and a cushioning member10, which overlies the electrode plate7. The cushioning member10has electrical insulation properties and is in sheet form. The cushioning member10is one form of the press member of the present invention. As with the press member8, the cushioning member10of the electrode member5B has the function of pressing and holding the electrode plate7. Specifically, with the given thickness of the cushioning member10, the height of a multilayer body composed of the cushioning member10and the electrode plate7is greater than the interior height of the electrode plate housing6a5. Thus, the electrode member5B is thin in profile and can restrict the movement of the electrode plate7.

Referring toFIG.5C, an electrode member5C includes the electrode plate7and an elastic member11, which overlies the electrode plate7. The elastic member11is a rubbery elastic body in sheet form and is elastically deformable in the thickness direction. The elastic member11is one form of the press member of the present invention. When the electrode member5C is fixed to the ceiling portion2a,the elastic member11is squashed. As with the press member8, the elastic member11thus has the function of pressing and holding the electrode plate7. The elastic member11is squashed when being fitted to the ceiling portion2a;therefore, the height of the electrode plate housing6a5may be less than the sum of the height of the electrode plate7and the height of the elastic member11in the free state. The electrode-housing member6does not include the top face portion6a1; therefore, the electrode plate housing6a5of the electrode-housing member6has a shape of a groove. The electrode plate7and the elastic member11are received in the electrode plate housing6a5. Thus, the electrode member5C inFIG.5Cis thinner in profile and can restrict the movement of the electrode plate7.

Referring toFIG.5D, an electrode member5D has a shape of a flat plate. Specifically, the electrode plate housing6a5of the electrode-housing member6has a shape of a shallow groove. The electrode plate7and a cushioning member12, which has electrical insulation properties and is in sheet form, are fitted in the electrode plate housing6a5. With the given thickness, the cushioning member12does not protrude from a top end of the electrode plate housing6a5as illustrated inFIG.5D. Alternatively, the cushioning member12may be thicker so as to protrude from the top end of the electrode plate housing6a5. The electrode-housing member6does not include the top face portion6a1. Thus, the electrode member5D inFIG.5Dis much thinner in profile and can restrict the movement of the electrode plate7.

The electrode members in5A to5D inFIG.5may be used as the electrode members5in other embodiments, which will be described later.

In the embodiment above, the electrode members5are fixed to the ceiling portion2a,and the ceiling interior finishing panel2a3is a resin panel (i.e., an interior finishing panel made of resin). Alternatively, the electrode members5may be fixed to the side wall portions2b,the front wall portion2c,or the floor portion2d.In this case, the interior finishing panel of each of the side wall portions2bor the interior finishing panel of the floor portion2dis a resin panel (i.e., an interior finishing panel made of resin). The interior finishing panel of the floor portion2dmay be a resin panel having T rails. Still alternatively, any two of the ceiling portion2a,the side wall portions2b,the front wall portion2c, and the floor portion2dmay include resin panels (i.e., interior finishing panels made of resin) for fixation of the electrode members5.

The whole of the ceiling interior finishing panel2a3of the ceiling portion2ain the embodiment above is a resin panel. In some embodiments, the ceiling interior finishing panel2a3may be composed of a plurality of ceiling interior finishing panels2a3connected to each other.

Second Embodiment (FIG.9)

FIG.9illustrates a ceiling interior finishing panel2a3of an electric field-generating container1according to a second embodiment. The ceiling interior finishing panel2a3in the second embodiment includes a resin panel portion2a6(i.e., a resin panel or an interior finishing panel made of resin) and a metallic frame plate2a7(i.e., a support member).

The resin panel portion2a6is a resin panel made of electrical insulating resin. The metallic frame plate2a7is a metallic plate having a shape of a polygonal frame. The metallic frame plate2a7may be a combination of metallic plates. The metallic frame plate2a7may be made of a metallic material such as stainless steel. The resin panel portion2a6is fastened to the metallic frame plate2a7with fasteners2f(e.g., screws or rivets) in different places. The resin plate portion2a6is provided with reinforcing members2a5, which are fastened thereto. The reinforcing members2a5are laid across the metallic frame plate2a7. This enables the metallic frame plate2a7to hold the resin plate portion2a6and provides greater rigidity in the entirety of the ceiling interior finishing panel2a3.

FIG.10illustrates a ceiling interior finishing panel2a3of an electric field-generating container1according to a third embodiment. The ceiling interior finishing panel2a3in the third embodiment includes resin panel portions2a8(i.e., resin panels) and a metallic frame plate2a9(i.e., a support member).

The resin panel portions2a8are discrete panels arranged side by side in the longitudinal direction of the container casing2. Referring toFIG.10, four resin panel portions2a8are provided. The metallic frame plate2a9includes a frame portion2a10and bridge portions2a11. The frame portion2a10has a shape of a polygonal frame, and the bridge portions2a11are laid across the frame portion2a10. The metallic frame plate2a9may be a combination of metallic plates. The metallic frame plate2a9may be made of a metallic material such as stainless steel. The resin panel portions2a8are fastened to the metallic frame plate2a9with fasteners2f(e.g., screws or rivets) in different places. The individual resin plate portions2a8are small in area and are held by the metallic frame plate2a9, which provides greater rigidity in the entirety of the ceiling interior finishing panel2a3accordingly.

In the first embodiment, the longitudinal direction of each electrode member5coincides with the longitudinal direction of the container casing2(i.e., the Y direction); that is, the electrode members5are arranged in the longitudinal direction. Alternatively, the longitudinal direction of each electrode member5may coincide with the width direction of the container casing2(i.e., the X direction), and the electrode members5may be arranged in parallel and spaced apart from each other in the longitudinal direction of the container casing2(i.e., in the Y direction); that is, the electrode members5may be arranged in the width direction.FIG.11illustrates an example of such an embodiment in which the electrode members5are arranged in the width direction. The arrangement of the electrode members5enables the conduction paths9(i.e., wiring) to be adjacent to one of the side wall portions2b(on the right or left side) in the width direction of the container casing2. This layout improves the interior design of the ceiling surface2a1having the conduction paths9routed thereon.

In the embodiments above, the conduction paths9are exposed to view in the accommodation chamber4. In some embodiments, meanwhile, the conduction paths9may be covered with a cover member that conceals them from view in the accommodation chamber4. One of these embodiments is a fifth embodiment, which will be described below. When the conduction paths9are disposed on only one side (the right or left side) in the width direction of the container casing2as in the fourth embodiment, cover members13may be arranged in a straight line in the longitudinal direction of the container casing2(i.e., in the Y direction) so as to conceal the conduction paths9from view in the accommodation chamber4. In the fifth embodiment, the cover members13are provided on the electric field-generating container1according to the fourth embodiment.

The cover members13are linked to each other and arranged in series. The cover members13are resin molded articles. As illustrated inFIG.14, the cover members13each include a base13aand a cover main body13b.The base13ais fastened to the ceiling interior finishing panel2a3, and the cover main body13bis attached to the base13a. Each cover member13is fastened to the ceiling interior finishing panel2a3with base fasteners13c(e.g., bolts).

The width of the base13ais shorter than its length (i.e., the dimension shown inFIG.14). The base13asupports the corresponding cover main body13bin two places in the longitudinal direction of the base13a.The base13amay have, for example, a length of 124 mm, a width of 30 mm, and a height of 20 mm. The base13aincludes catch receiving portions13a1, which are groove-shaped.

The cover main body13bis a resin molded article that is recessed (i.e., is v-shaped and protrudes downward). The cover main body13bincludes a pair of inclined face portions13b1, a flat face portion13b2on lower ends of the inclined face portions13b1, and upright portions13b3on upper ends of the inclined face portions13b1. The inclined face portion13b1of the cover main body13bcauses water on the cover main body13bto flow into the flat face portion13b2, where the water is drained from holes13b4, which will be described later. The cover main body13bmay have, for example, a length of 1,200 mm, a width of 130 mm, and a height of 45 mm.

The flat face portion13b2has the holes13b4aligned in the longitudinal direction of the cover main body13b. The holes13b4are through-holes from which condensation on the inside of the cover member13may be drained. The holes13b4may be elongated holes each having a length of 10 mm and a width of 8 mm and may be discretely located away from each other with a center-to-center distance of 250 mm. The upright portions13b3are provided with hook portions13b5, which are located at top ends of the upright portions13b3and are fitted into the catch receiving portion13b1of the base13a.Each hook portion13b5is folded over to increase the stiffness of the upper end portion of the corresponding upright portion13b3and to be securely fitted into the corresponding catch receiving portion13a1.

The cover members13protect the conduction paths9from external forces exerted thereon. This is particularly advantageous during loading of products for storage into the accommodation chamber4or unloading of stored products from the accommodation chamber4. This layout improves the aesthetics of the interior design of the ceiling interior finishing panel2a3having the conduction paths9routed thereon.

Sixth Embodiment (FIG.15A) and Seventh Embodiment (FIG.15B)

The electrode plates7in the embodiments above each have a shape of a strip; however, the size and the shape of each electrode plate7is not limited to those of such a strip. It is required that the length of each electrode plate7in the width direction of the container casing2(i.e., in the X direction) be less than the length of the ceiling surface2a1in the width direction (i.e., in the X direction). It is also required that the length of each electrode plate7in the longitudinal direction of the container casing2(i.e., in the Y direction) be less than the length of the ceiling surface2a1in the longitudinal direction (i.e., in the Y direction). The electrode plates7may each have a shape of a panel as illustrated inFIG.15A or15B.

FIG.15Aillustrates a ceiling interior finishing panel2a3of an electric field-generating container1according to a sixth embodiment. A matrix of electrode members5with two rows and four columns is provided on a ceiling surface2a1. The electrode members5each have a shape of a rectangular panel.FIG.15Billustrates a ceiling interior finishing panel2a3of an electric field-generating container1according to a sixth embodiment. Four electrode members5are aligned in a row on a ceiling surface2a1. The electrode members5each have a shape of a substantially square panel. The electrode members5inFIGS.15A and15Binclude electrode plates7shaped and sized in conformance with the shape of the respective electrode members5. A container casing2and the electrode members5are exclusively illustrated inFIG.15for the purpose of facilitating the understanding.

Modifications of Embodiments

Configurations in the embodiments are applicable to other embodiments. The following modifications may be applied to the embodiments above.

The electric field generation controller3jin the embodiments above is disposed in the lower section of the frame body3c1of the reefer apparatus3. Alternatively, the electric field generation controller3jmay be disposed in another place within the reefer apparatus3(i.e., may be disposed in the upper section or in the middle section of the frame body3c1).

The electric field generation controller3jin the embodiments above includes the upper hatch3j3and the lower hatch3j4. Alternatively, the electric field generation controller3jmay include three or more hatches. In some embodiments, the upper hatch3j3may be composed of a plurality of hatches.

The embodiment of the present invention has been described in detail so far. Those skilled in the art would readily understand that various modifications may be made within the scope that does not substantially depart from the configurations and effects of the present invention. Thus, such modifications are all included within the scope of the present invention.

For instance, a term in any part of the present specification or the accompanying drawings can be paraphrased into another term having a wider or similar meaning and written along with the relevant term at least once in the present specification or in the drawings. The configuration and the operation of the electric field-generating container1are not limited to those described in the embodiments of the present invention and may be modified for implementation in various ways.

REFERENCE SIGNS LIST