JP5584496B2 - Long metal foil heater and manufacturing method - Google Patents

Description

  The present invention relates to a long metal foil heater in which a conductive portion having low resistance and low heat generation and a heating portion having high resistance and high heat generation are alternately distributed. Although the long metal foil heater of the present invention is not intended to be limited to this, for example, by directly winding around the plants such as strawberries and roses planted at equal intervals, or by installing them in the vicinity, It is suitable for use in agricultural and horticultural long heaters that heat plants and promote the growth of plants.

  For example, in the conventional winter cultivation of plants such as strawberries and roses, in order to ensure the yield and quality, the inside of the greenhouse is kept at a predetermined temperature (eg, strawberry is 8 ° C or higher), and the temperature of the surrounding soil is predetermined. The temperature range is set (eg, strawberry is 14 ° C. or higher). However, according to recent research, in strawberries and roses, the temperature in the house can be lowered by about 3 ° C if only the vicinity of the plant stem (crown) is set to a predetermined temperature (eg, 16-20 ° C for strawberries). I understood that. Thereby, the heating cost in winter can be reduced by 50% or more (Non-Patent Document 1).

  The heater used for such heating is used in the equipment configuration as shown in FIG. That is, the current supplied from the 100V or 200V power source by the electric cord 30 is controlled by the temperature controller 31 to adjust the temperature of the heater 32 to keep the plant 34 warmed to a predetermined temperature. The temperature of the plant 34 is measured by the thermocouple 33 and fed back to the temperature controller 31. The current agricultural heater uses a cord heater. As shown in FIG. 14, the cord heater has a structure in which a heater wire 36 such as nichrome is wound around the outside of the glass wool core 35 and the outside is covered with an electrical insulating material 37 such as a fluororesin, so that it is bent to a small radius. Nichrome wire is easy to break. Therefore, as shown in FIG. 15, the cord heater 38 only passes over the cultivating soil 43 on the side of the stem 40, which is also called a crown, and since the cross section with an outer diameter of about 3 mm is circular, the contact area with the plant is small. Therefore, heat transfer to plants is very bad. In the case of a strawberry, the leaves 41 and the strawberry fruits 42 sprout from the stem 40 and grow. Strawberries are planted at intervals of about 20 cm.

  The present applicant has provided a long strip metal foil heater that has many uses, not limited to agriculture and horticulture (Patent Document 1). This heater can be used as a planar heater by folding a band, or in a three-dimensional shape that wraps a flower pot. However, in the individual heating of a large number of strawberries, roses, etc. planted at regular intervals on the straw, the resistance distribution is uniform over the entire length as in the case of the cord heater described above, and thus the power consumption efficiency is low.

Zen No Fukuoka Headquarters July 2009 "Fukuoka Vegetable Vege" No.135 P64-P66 JP 2010-3487 A

  In the case of a cord heater, since the whole is a heater, there is a disadvantage that the heating cost of the plant by the cord heater has the same level of power cost as the heating cost of the house has been reduced due to reasons such as heating parts other than the plant. is there.

  The present applicant has provided a long strip metal foil heater that has many uses, not limited to agriculture and horticulture (Patent Document 1). This heater can be used as a planar heater by folding a band, or in a three-dimensional shape that wraps a flower pot. However, in the individual heating of a large number of strawberries, roses, etc. planted at regular intervals on the straw, the resistance distribution is uniform over the entire length as in the case of the cord heater described above, and thus the power consumption efficiency is low.

  The first object of the present invention is to increase the power consumption efficiency of heating. For example, when used for agriculture and horticulture, it is bent so that it can be easily wrapped around the shape of the plant, and even when bent, it can be produced in any size without disconnection and can be produced in any size. The second object is to provide a long metal foil heater that can be easily wound up and is excellent in workability, safety and economy.

  In order to achieve the above object, the present invention increases the electrical resistance by reducing the cross-sectional area of the portion of the metal foil tape that requires heating in the longitudinal direction. There are two ways to reduce the cross-sectional area: a thick metal foil used as a heating part and a thick metal foil used as a conductive part connected by welding, etc. There is a different width form that makes the heating part smaller. A long metal foil whose thickness or width is reduced at a predetermined pitch is covered with a flexible electrical insulator to form a long metal foil heater. In particular, a heating part, for example, a part for heating a plant body, promotes heating by using a strip-shaped metal foil having a small cross-sectional area, and a conductive part between the heating parts is formed by using a strip-shaped metal foil having a large cross-sectional area. Suppresses heat generation at Specifically, the present invention is as follows.

(1) A heating part for heating a predetermined part of a large number of plants planted at a predetermined interval or a part near the plant body, and a conductive part having a cross-sectional area larger than the heating part , in the longitudinal direction A long metal foil heater for heating a plant , comprising a long metal foil distributed alternately in a large number , and a flexible electric insulator coated with the long metal foil.

(2) The long metal foil heater for heating a plant body according to (1) above , wherein the conductive portion of the long metal foil and the heating portion are made of the same material .

(3) The said long metal foil consists of the conductive part of thick metal foil, and the heating part of the thin metal foil welded to it, The long length for plant body heating as described in said (1) or (2) Metal foil heater.

(4) The long metal foil is composed of a conductive part of a wide metal foil and a heating part of a narrow metal foil continuous thereto, and the long metal for heating a plant according to (1) or (2) above. Foil heater.

  (5) The long metal foil heater according to any one of (1) to (4), wherein the long metal foil is coated with a flexible electrical insulator by coating.

(6) The long metal foil for heating a plant body according to any one of (1) to (4), wherein the long metal foil is coated with a flexible electrical insulator by taping. heater.

(7) The metal foil tape wound around the uncoiler is stopped after being fed to a press of a predetermined length with a feeder, and the metal foil tape is punched out with the press to form the heating portion , and these operations are repeated many times. The method for producing a long metal foil for heating a plant according to (4), which is repeatedly wound on a reel.

(8) The long metal foil wound around the uncoiler is rewound, washed and dried with a washing / drying device, and the flexible electrical insulator is coated and dried with a coating machine to remove the long metal foil. The method for producing a long metal foil heater for heating a plant according to any one of (1) to (6), which is covered and wound on a reel.

(9) The long metal foil wound around the uncoiler is rewound, and the upper side of the long metal foil is rewound the tape of the flexible electrical insulator that is tape-wound and guided by a guide roll. The tape of the flexible electrical insulator covered with the tape with the pressure roll and the lower side of the tape is also rewound and guided by the guide roll and covered with the tape with the pressure roll. The method for producing a long metal foil heater for heating a plant body according to any one of the above (1) to (6), wherein a long metal foil heater having both sides coated with the tape is wound up by a recoiler.

  Since long metal foil can change a cross-sectional area in the longitudinal direction arbitrary positions, the heating part which heats only a required part according to the magnitude | size and position of a heating object can be comprised simply. In addition, since the long metal foil has a flat surface and is bent to a small bending radius, it can be efficiently heated by being wound around a heating object such as a plant body. In addition, it can be easily wound on a reel before and after use, so it is excellent in workability and storage. Electrical insulators are not only electrically insulative, but also have excellent heat resistance, chemical resistance, and wear resistance, and are safe for long-term use.

It is a top view which shows one form of the elongate metal foil heater of this invention. It is an enlarged plan view which shows the connection part of the low resistance conductive part 2 of the elongate metal foil heater shown in FIG. 1, and the covering copper wire 4 which is a feeder. It is a top view which shows the shape of the connection end part of the electroconductive part 2 shown in FIG. It is an expansion perspective view which shows the long metal foil (low resistance conductive part 2, high resistance heating part 1) of the 1st form of the long metal foil heater shown in FIG. It is an expansion perspective view which shows the long metal foil (low resistance conductive part 2, high resistance heating part 1) of the 2nd form of the long metal foil heater shown in FIG. It is an expansion perspective view which shows the long metal foil (low resistance conductive part 2, high resistance heating part 1) of the 3rd form of the long metal foil heater shown in FIG. It is a block diagram which shows the outline | summary of the production line of the long metal foil of a 2nd and 3rd form. It is an expanded cross-sectional view of the long metal foil heater which coat | covered the long metal foil with the electrical insulator which has flexibility. It is a block diagram which shows the outline | summary of the coating line which coat | covers the electrical insulator which has flexibility to elongate metal foil by coating. It is a block diagram which shows the outline | summary of the coating line which coat | covers the electrical insulator which has flexibility to a long metal foil by taping. In the expanded cross-sectional view of the long metal foil heater which covered the long metal foil which connected the thick low resistance conductive part 2 and the thin high resistance heating part 1 by the spot welding with the electric insulator tape which has flexibility is there. It is a perspective view which shows the usage condition of the elongate metal foil heater of one form of this invention. It is a block diagram which shows the equipment for plant heating using the conventional cord heater. It is a top view which fractures | ruptures and shows the conventional cord heater. It is a perspective view which shows the arrangement | positioning form for the plant heating of the conventional cord heater shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, one form of the elongate metal foil heater of this invention is shown. The current that flows from the coated copper wire 4 that is a power supply line flows through the power supply line connecting portion 3 to the conductive portion 2 of the long metal foil heater. The connection part 3 has a structure as shown in FIG. In other words, the metal foil stripped tip 5 having a narrow connection width between the coated copper wire 4 and the conductive portion 2 is crimped and connected by a commercially available feeder crimping tube 6. The reason why the width of the conductive part 2 on the connection side is narrowed is to facilitate insertion into the crimping tube 6 during crimping and to prevent the metal foil from being broken. In FIG. 3, the front-end | tip part 5 before inserting in the crimping tube 6 is shown. In FIG. 3, the width A of the tip 5 is easily 3 to 5 mm. The length of the tip 5 is preferably 3 mm or more, and the angle θ is preferably 30 ° or more in order to suppress the electrical resistance heat generation of the connecting part 3. After the connection, the crimping tube 6 and the front and back thereof are electrically insulated by a commercially available heat shrinkable tube (not shown).

  The conductive portion 2 has a large cross-sectional area to reduce electrical resistance so that heat is not generated as much as possible. The current flows from the conductive portion 2 to the heating portion 1 having a reduced cross-sectional area and an increased electrical resistance. The heating unit 1 generates a large amount of heat and is suitable for heating strawberries and other plants to the required temperature. The form of the heating part 2 has a smaller cross-sectional area than the conductive part 2 so that the electrical resistance is higher than that of the conductive part 2 and heat generation is concentrated on the warming part 2. There are two types of forms for reducing the cross-sectional area. One is a form in which the thickness of the long metal foil covered with a flexible electrical insulator is changed thinly, and the other is a form in which the width is changed narrowly. In the form in which the wall thickness is changed, for example, as shown in FIG. 4, the thick-walled (low resistance) conductive portions 2 and the thin-walled (high resistance) heating portions 1 are alternately arranged in the longitudinal direction and spot-welded between them. . The welded portion 7 is subjected to two or more points in consideration of an emergency break during use. What is important in welding is the length D of the overlapping of the conductive portion 2 and the heating portion 1. When the overlap length D is too small, it is difficult to align the welding position. When the overlap length D is too large, the electric insulator is easily peeled off when bent. For the conductive part 2 and the heating part 1 using a metal foil tape, a metal foil having a thickness of 20 to 300 μm and having a suitable electrical resistance, such as aluminum, aluminum copper alloy, stainless steel, nichrome, etc., is used. Stainless steel is desirable in consideration of strength and economy. When the thickness is less than 20 μm, the strength is insufficient, and the production cost is significantly increased. Moreover, when it becomes 300 micrometers or more, it cannot be bent easily.

  In the case where the width of the metal foil is changed narrowly, for example, there is a method shown in FIGS. In FIG. 5, the inside 8 of the metal foil tape 2 is punched out with a punch to create the heating unit 1. In this case, a portion not punched in the longitudinal direction becomes the conductive portion 2. Moreover, FIG. 6 is a case where both sides of the metal foil tape 2 are punched, and the portion 1 left in the width direction becomes a heating portion.

  FIG. 7 shows a process for punching. After the metal foil tape 26 wound around the uncoiler 9 is fed by a feeder 10 for a predetermined length, it is stopped and punched by a press 11 having a die and a punch to form a predetermined shape (for example, FIGS. 5 and 6). repeat. The punched different width metal foil tape 12 is wound around a take-up reel 13. These feeders 10, dies, punches, and presses 11 can be commercially available. In addition, as a technique for changing the width of the metal foil narrowly, a commercially available laser cutting machine and etching equipment can be used.

  As shown in FIG. 8, the heating unit 1 is covered with a flexible electrical insulator 14. Similarly, the conductive portion 2 is covered with a flexible electrical insulator. As a coating method of the electrical insulator 14, there is a method of taping paint and electrical insulation tape.

  FIG. 9 shows a side view of an apparatus for coating a flexible electric insulator on a long metal foil having a different cross-sectional area due to different thickness or width. The metal foil 15 having a different cross-sectional area is unwound from the uncoiler 9, cleaned and dried by a cleaning / drying device 16, and a flexible electrical insulator 14 is coated by a coating machine 17. The long metal foil heater 18 thus manufactured is wound up by a recoiler 19. It is sufficient that the cleaning is performed using commercially available ionic water or a hydrocarbon-based cleaning solution. For the coating, a commercially available electrodeposition coating, electrostatic coating or resin coating can be used. For the flexible electrical insulator 14, flexible polyimide, Teflon (registered trademark), silicon, polyester, synthetic rubber, urethane rubber, epoxy resin, or the like is used according to the operating temperature. The thickness of the flexible electrical insulator 14 is preferably 10 μm or more in order to ensure stable electrical insulation, and is preferably 100 μm or less in order to obtain good bending flexibility.

  Insulator coating, in which the long metal foil 15 is taped with a flexible electrical insulator to form a long metal foil heater, is performed by the apparatus shown in FIG. The long metal foil 15 having a different cross-sectional area that has been rewound from the uncoiler 9 is simultaneously covered with a flexible electrical insulator tape at the upper and lower surfaces. On the upper side of the long metal foil 15, the electric insulator tape 23a unwound from the electric insulator tape winding 20a is guided by a guide roll 21a having a flange so as not to cause a width deviation, and the long metal foil 15 is moved by the pressure roll 22a. The foil 15 is covered. Similarly, on the lower side, the electrical insulator tape 23b unwound from the electrical insulator tape winding 20b is guided by the guide roll 21b and covered with the pressure roll 22b. The long metal foil heater 27 whose both surfaces are covered with the electrical insulating tape is wound up by the recoiler 19. A commercially available electrical insulator tape is used. The support film of the electrical insulator tape is made of polyester, epoxy, glass cloth, etc., and the wall thickness is preferably 0.05 to 0.2 mm. If it is less than 0.05 mm, there is a problem in use strength, and if it exceeds 0.2 mm, it cannot be bent easily. The adhesive is rubber or acrylic.

  In FIG. 11, the different thickness connection part of the long metal foil heater using a different thickness thick metal foil is shown. The different thickness metal foil is obtained by spot welding three points in the width direction. The conductive part 2 and the heating part 1 are connected by a molten steel part 7 made by spot welding. Since the thickness of the different thickness thick metal foil is the thickest at the spot-welded portion, the gap 24 surrounded by the upper electrical insulator tape 23a, the lower electrical insulator tape 23b, and the metal foil side surface is large. The gap 24 slightly expands when the long metal foil heater is bent. The amount of spread differs slightly depending on the position and accuracy in the longitudinal and width directions of spot welding. In practice, the width of the adhesive surface 25 between the electrical insulator tapes 23a and 23b changes due to the displacement in the width direction of the conductive portion 2 and the heating portion 1, the displacement in the width direction of the electrical insulator tapes 23a and 23b, and the like. It is necessary to determine the heater width in consideration of these variations. The dimension C in the figure is the distance between the side surface of the long metal foil and the side surface of the electrical insulator tape. Then, if it is 3 mm or more and 0.4 mm or less, 4 mm or more is desirable.

  Examples of the present invention will be described below. In the long metal foil heater of the present invention shown in FIG. 1, JIS standard SUS304 stainless steel was used for the conductive portion 2 and the heating portion 1 of the long metal foil. The width, thickness, length, and number shown in Table 1 were used for the different thickness form and the different width form. As for the connection between the conductive portion 2 and the coated copper wire 4 having different thicknesses, the dimension A shown in FIG. 3 was 4 mm, B was 5 mm, and θ was 90 °. After stripping the coating of the coated copper wire 4 on the commercially available crimping tube 6 and putting the copper wire and the tip 5 part of the conductive portion 2 together and crimping, the crimping tube 6 and its front and back are covered with a commercially available heat shrink tube. did. Different width forms were punched using a commercially available punch and die. The same length was used for the conventional cord heater.

  The flexible electrical insulator 14 for covering the long metal foil is a commercially available heat-resistant 130 ° C. guaranteed polyester wall tape having a thickness of 60 μm and a width 6 mm wider than the metal foil tape width. From, it stuck by the apparatus shown in FIG. The long metal foil heater thus produced was applied to strawberries planted at intervals of 20 cm. In this long metal foil heater, as shown in FIG. 12, the heating unit 1 is wound about half a turn directly around the stalk base 40 with a pin 44. The cord heater 38 of the conventional example is attached to the stem 40 as shown in FIG. As a result of lowering the house temperature from 8 ° C. to 5 ° C. during the winter season from October to March and setting the ground temperature just below the stem to 15 ° C. to 17 ° C., the long metal foil heater of the present invention and None of the conventional cord heaters 38 grew in the same manner as the conventional 8 ° C., and no difference was observed in the strawberry yield. During the use period of the heater, watering, fertilizer, and powder were performed as usual. Table 1 shows the power consumption ratio. Compared with the case where the cord heater 38 of the conventional example is used, the power consumption of the long metal foil heater of the present invention is almost half or less. Further, the long metal foil heater of the present invention had no problem even when wound on a core having an outer diameter of 96 mm before and after use. Moreover, there was no problem as a result of investigating the electrical insulation of the long metal foil heater of the present invention after use.

  The long metal foil heater of the present invention can be economically provided with an arbitrary width and length having an arbitrary number of heating portions of an arbitrary length at an arbitrary interval (conductive portion length). It is possible to efficiently heat the growth points of plants planted in (eg, strawberries, roses, eggplants, etc.). It is flexible and can be easily wound around plants with different complicated shapes and different outer diameters, resulting in good heating efficiency. Moreover, since it can wind up and use for a core, it is excellent in workability | operativity.

1: Heating part 2: Conductive part 3: Connection part of conductive part 4: Coated copper wire 5: Tip of conductive part 6: Crimp tube 7: Spot welded part 8: Internal cavity of long metal foil heater 9: Uncoiler 10 : Feeder 11: Press 12: Long metal foil with different width 13: Take-up reel 14: Flexible electrical insulator 15: Long metal foil with different cross section 16: Washing and drying device 17: Coating machine 18: Long Metal foil heater 19: Recoiler 20a, 20b: Electrical insulation tape winding 21a, 21b: Guide roll 22a, 22b: Crimp roll 23a, 23b: Electrical insulation tape 24: Gap 25: Adhesive portion 26 between tapes 26: Metal foil tape 27: Long metal foil heater 30: Electric cord 31: Temperature controller 32: Heater 33: Thermocouple 34: Plant 35: Glass wool core 36: Heater wire 37: Electrical insulating material 38: Cord heater 39: Plant Roots 40: Kukimoto 41: plant leaves 42: Strawberry fruit 43: soil 44: pin

Claims (9)

A heating part for heating a predetermined part of a large number of plants planted at a predetermined interval or a part near the plant body, and a conductive part having a larger cross-sectional area than the heating part are alternately arranged in the longitudinal direction. A long metal foil heater for heating a plant comprising a long metal foil distributed in large numbers and a flexible electric insulator coated with the long metal foil. The long metal foil heater according to claim 1, wherein the conductive portion of the long metal foil and the heating portion are made of the same material . The long metal foil heater for heating a plant body according to claim 1 or 2, wherein the long metal foil comprises a conductive portion of a thick metal foil and a heating portion of a thin metal foil welded thereto. The long metal foil heater for heating a plant body according to claim 1 or 2, wherein the long metal foil comprises a conductive portion of a wide metal foil and a heating portion of a narrow metal foil continuous thereto. The long metal foil heater for heating a plant body according to any one of claims 1 to 4, wherein the long metal foil is coated with a flexible electrical insulator by painting. The long metal foil heater for plant heating according to any one of claims 1 to 4, wherein the long metal foil is coated with a flexible electrical insulator by taping. The metal foil tape wound around the uncoiler is stopped after being fed to a press with a predetermined length by a feeder, and the metal foil tape is punched out with the press to form the heating portion , and these operations are repeated many times on the reel. The manufacturing method of the long metal foil for plant body heating of Claim 4 wound up. The long metal foil wound around the uncoiler is rewound, washed and dried with a washing and drying device, the flexible electrical insulator is coated and dried with a coating machine, and the long metal foil is coated and reeled. The manufacturing method of the elongate metal foil heater for plant body heating as described in any one of Claims 1 thru | or 6 wound up by. The long metal foil wound around the uncoiler is rewound, and the upper side of the long metal foil is rewound with the tape of the flexible electrical insulator wound around the tape and guided by a guide roll. The tape of the flexible electrical insulator covered with the tape and similarly wound on the lower side is rewound and guided with a guide roll, and covered with the tape with a pressure roll, and both upper and lower sides are covered. The manufacturing method of the long metal foil heater for plant body heating as described in any one of Claims 1 thru | or 6 which winds up the long metal foil heater coat | covered with the said tape with a recoiler.

Images