Temperature control method for heating surface of heating element for feet and heating element for feet

Abstract

To provide a temperature control method for a heating surface, and a heating element capable of not only controlling temperature distribution in the heating surface of a heating element for feet, but also suppressing movement of a heating material to one side.SOLUTION: A temperature control method for a heating surface 6 is a temperature control method for controlling the temperature distribution of the heating surface 6 in a heating element 1. The heating element 1 includes a heating material 4 and a bag body 2 in which the heating material 4 is encapsulated, and which includes the heating surface 6 at least on one surface. The temperature control method for the heating surface 6 prevents conduction of heat from outside a partitioning part 51 to inside the partitioning part 51 by the partitioning part 51 surrounding one range in the heating surface 6 viewed from the front, and controls the temperature distribution of the heating surface 6.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for controlling the temperature of a heating surface of a foot warmer and a foot warmer.

Background Art

[0002] Patent Document 1 discloses a conventional heating element. The heating element described in Patent Document 1 includes a heat-generating composition (heat-generating material) that generates heat by coming into contact with air, and a storage bag (bag body) that stores the heat-generating composition. The storage bag is formed in a bag shape by sealing the outer peripheral edges of two sheet materials together.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, for example, in cold outdoor environments in winter such as farming work, markets, and snowy mountains, since the feet get cold, the heating element described in Patent Document 1 may be placed between the feet and the shoes and used.

[0005] However, in the heating element described in Patent Document 1, looking at the temperature distribution of the heating surface, a high-temperature region is formed in the central part when viewed from the front. On the other hand, by placing the high-temperature region in a desired position in the foot warmer, for example, warming the toes (tips of the fingers), further expansion of the use of the heating element is expected, but there is no known technology for placing the high-temperature region in a desired position. On the other hand, since the foot warmer is sandwiched between the feet and the inner surface of the shoes, a local high temperature rise in this high-temperature region is not very preferable.

[0006] In addition, in the heating element described in Patent Document 1, when it is disposed between the foot and the shoe, it is greatly shaken during walking, so there is a problem that the heating material tends to shift inside the bag body.

[0007] An object of the present invention is to provide a method for controlling the temperature distribution of the heating surface of a foot heating element and a foot heating element, which can control the temperature distribution of the heating surface of the foot heating element and suppress the shift of the heating material.

Means for Solving the Problems

[0008] A method for controlling the temperature of the heating surface of a foot heating element according to an aspect of the present invention is a temperature control method for controlling the temperature distribution of the heating surface of a foot heating element disposed between a user's foot and a shoe. The foot heating element includes a heating material and a bag body that encloses the heating material and has a heating surface on at least one surface. A partition portion that surrounds a range on the heating surface as viewed from the front prevents heat conduction from the outside to the inside of the partition portion and controls the temperature distribution of the heating surface.

[0009] In addition, in the method for controlling the temperature of the heating surface of the foot heating element, it is preferable that the partition portion prevents heat conduction from the outside to the inside of the partition portion by excluding the heating material as viewed from the front.

[0010] In addition, in the method for controlling the temperature of the heating surface of the foot heating element, it is preferable to exclude the heating material also from the inner portion of the partition portion as viewed from the front.

[0011] In addition, in the method for controlling the temperature of the heating surface of the foot heating element, the bag body has a front sheet portion and a back sheet portion, and the partition portion is configured by joining the front sheet portion and the back sheet portion, and is thereby configured to exclude the heating material.

[0012] In addition, in the method for controlling the temperature of the heating surface, it is preferable that the entire surface of the portion (inner portion) inside the partition portion is formed by joining the front sheet portion and the back sheet portion.

[0013] In addition, in the method for controlling the temperature of the heating surface of the foot heater, it is preferable to control the temperature distribution of the heating surface by changing the size or shape of the partition portion.

[0014] A foot heater according to one aspect of the present invention is a foot heater disposed between a user's foot and a shoe. The foot heater includes a heating material and a bag body that encloses the heating material and has a heating surface on one side. A partition portion is formed in the bag body so as to surround a range on the heating surface and prevent heat conduction from the outside to the inside.

[0015] In addition, in the foot heater, it is preferable that the bag body has a front sheet portion and a back sheet portion, and the partition portion is formed by excluding the heating material from between the front sheet portion and the back sheet portion.

[0016] In addition, in the foot heater, it is preferable that the heating material is also excluded from the portion inside the partition portion when viewed from the front.

[0017] In addition, in the foot heater, it is preferable that the bag body has a front sheet portion and a back sheet portion, and the partition portion is configured by joining the front sheet portion and the back sheet portion, and thereby configured to exclude the heating material.

[0018] In addition, in the foot heater, it is preferable that the entire surface of the portion (inner portion) inside the partition portion is formed by joining the front sheet portion and the back sheet portion.

Advantages of the Invention

[0019] The method for controlling the temperature of the heating surface of the foot warmer according to the above aspect of the present invention and the foot warmer have the advantages that they can lower the maximum temperature on the heating surface, suppress local high temperature rise, and suppress the uneven distribution of the heating material.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0021] (1) Embodiment Hereinafter, the method for controlling the temperature of the heating surface of the foot warmer 1 according to the present embodiment (hereinafter, may be simply referred to as "temperature control method") and the foot warmer 1 will be described in detail.

[0022] As shown in Fig. 1, the foot warmer 1 according to this embodiment is arranged and used between the user's foot 7 and the shoe 8. In this embodiment, it is arranged between the fingertip-side part of the sole 71 of the user's foot and the toe-side part of the insole 81 of the shoe 8. Examples of the shoe 8 include sports shoes, sneakers, shoes, leather shoes, boots, long boots (including long boots), slippers, etc., but it is not particularly limited. Also, the "user's foot 7" here means a foot or bare foot wearing socks, stockings, tights, etc.

[0023] In the foot warmer 1, usually, when it is used for the purpose of warming the feet, its heating temperature is designed to be 25°C or more and 50°C or less, preferably 30°C or more and 45°C or less (the temperature measurement method conforms to the foot warmer temperature measurement method of the Cairo Industrial Association) in a 20°C environment.

[0024] In the following description, first, the temperature control method of the heating surface 6 of the foot warmer 1 will be described, and then the foot warmer 1 to which this temperature control method is applied will be described in detail.

[0025] (1.1) Temperature control method The temperature control method according to this embodiment is, for example, a method of controlling the temperature distribution of the heating surface 6 of the foot warmer 1 as shown in Fig. 2. This foot warmer 1 includes a heating material 4 (Fig. 3(A)) and a bag body 2 that encloses the heating material 4 and has a heating surface 6.

[0026] In the temperature control method according to this embodiment, as shown in Fig. 2, by forming a partition portion 51 (preferably a heating material exclusion portion 5) at any position on the heating surface 6, the heat conduction from the outside to the inside of the partition portion 51 is blocked, and the temperature distribution of the heating surface 6 is controlled. The partition portion 51 according to this embodiment is constituted by the outer peripheral portion of the heating material exclusion portion 5 formed at any position on the heating surface 6.

[0027] When viewed from the front, the heating element exclusion part 5 is a part where the heating material 4 is excluded and there is no heating material 4. The outer peripheral part of the heating element exclusion part 5 (that is, the partitioning part 51) prevents heat conduction from the outside (the heating material 4 side) of the heating element exclusion part 5 to the inside of the heating element exclusion part 5. That is, in the heating element 1 according to the present embodiment, since heat conduction from the heating material 4 toward the inside of the partitioning part 51 is blocked, heat generation at the heating element exclusion part 5 of the heating surface 6 is suppressed. The heating element exclusion part 5 according to the present embodiment may be located at any position on the heating surface 6. For example, it may be formed at a position overlapping the centroid 9 (center) of the heating surface 6, or may be formed at a position deviated from the centroid 9 of the heating surface 6.

[0028] For example, when trying to lower the maximum temperature to a predetermined temperature and increase the area of the high-temperature region including the lowered maximum temperature for the heating surface 6 where the partitioning part 51 is not formed, a partitioning part 51 (heating element exclusion part 5) with a predetermined size (area) may be formed at the center part of the heating surface 6 (this is defined as the reference heating surface 6 and the reference partitioning part 51 (reference heating element exclusion part 5)). Here, the "center part of the heating surface 6" means a range including the centroid 9 of the heating surface 6 when the heating surface 6 is viewed from the front (viewed in the direction perpendicular to the heating surface 6) (hereinafter, front view). When trying to further lower the maximum temperature for this reference heating surface 6, the partitioning part 51 (heating element exclusion part 5) is designed to be larger than the reference partitioning part 51 (reference heating element exclusion part 5). On the other hand, when trying to prevent the maximum temperature from dropping to the reference heating surface 6, the partitioning part 51 (heating element exclusion part 5) may be designed to be smaller than the reference partitioning part 51 (heating element exclusion part 5).

[0029] Also, when trying to lower the maximum temperature to a predetermined temperature and move the position of the high-temperature region including the lowered maximum temperature for the heating surface where the heating element exclusion part 5 is not formed, a partitioning part 51 (heating element exclusion part 5) may be formed at a position deviated from the centroid 9 of the heating surface 6. When trying to adjust the area of the high-temperature region while maintaining the position of the high-temperature region for this heating surface 6, the size or shape of the partitioning part 51 (the area or shape of the heating element exclusion part 5) may be adjusted.

[0030] Thus, in the temperature control method according to this embodiment, by forming the partition portion 51 so as to surround the centroid 9, it is possible to lower the maximum temperature with respect to the heat generating surface without the partition portion 51, and increase the area of the high temperature region including the lowered maximum temperature, thereby improving the uniformity of the temperature distribution. Further, by changing the size or shape of the partition portion 51, the maximum temperature can be adjusted while keeping the area of the high temperature region substantially the same. Furthermore, the position of the high temperature region can be adjusted according to the position of the partition portion 51 (heat generating material exclusion portion 5). In short, according to the temperature control method according to this embodiment, the temperature distribution of the heat generating surface 6 can be controlled.

[0031] As used in this disclosure, the "high temperature region" means a temperature region of the heat generating surface that is (maximum temperature - 5°C) or higher and at most the maximum temperature.

[0032] (1.2) Foot warmer The foot warmer 1 according to this embodiment can apply heat to a part of the foot 7 that contacts the bag body 2 by the heat generating material 4 generating heat, thereby providing a warming effect to the foot 7. The foot warmer 1 according to this embodiment uses, for example, a disposable warmer that uses the reaction heat generated when an oxidation reaction occurs in the heat generating material 4 as a heat source. The foot warmer 1 according to this embodiment is, for example, housed in an outer bag (not shown) having airtightness that does not allow air to pass through before use. However, the foot warmer 1 according to this disclosure is not limited to a disposable warmer, and may be, for example, a warming appliance in which the heat generating material 4 has heat by irradiating the foot warmer 1 with microwaves using a microwave oven or the like.

[0033] The foot warmer 1 according to this embodiment has a heat generating surface 6 on the surface of the bag body 2. As used in this disclosure, the "heat generating surface 6" means the surface of the bag body 2 surrounded by the outer periphery that forms a space for housing the heat generating material 4 in the bag body 2. In the foot warmer 1 according to this embodiment, the heat generating surface 6 is the main surface of the substantially rectangular bag body 2 surrounded by the edge portion 31 (outer periphery that forms a space for housing the heat generating material 4) described later, and the foot warmer 1 has a pair of front and back heat generating surfaces 6. The front view and the back view of the heat generating body 1 are the directions of viewing the heat generating surface 6 from the front.

[0034] The size of the heat generating surface 6 is appropriately determined according to the part to which the heating effect is to be applied. For example, for use targeting the sole 71, the foot heating element 1 having a relatively large heat generating surface 6 is appropriate. For example, for use targeting relatively narrow parts such as the instep, side, heel, and ankle of the foot 7, the foot heating element 1 having a heat generating surface 6 of normal size is appropriate. However, this is only an example, and for example, the foot heating element 1 having a relatively large heat generating surface 6 may be used for a relatively narrow part.

[0035] (1.2.1) Heat generating material The heat generating material 4 is a material capable of generating heat. In the present embodiment, it is a powdery material that generates heat by coming into contact with air. The heat generating material 4 is enclosed in the bag body 2.

[0036] The heat generating material 4 includes, for example, an oxidizable metal, activated carbon, carbon black, a water retention agent, a metal salt (for example, table salt), and water. The oxidizable metal is a metal that generates heat of oxidation reaction, and is selected from, for example, iron, aluminum, zinc, manganese, magnesium, and calcium Examples include one or more kinds of powders or fibers. Among these, iron powder is preferable from the viewpoints of handleability, safety, manufacturing cost, storage stability, and stability. Examples of the iron powder include one or more kinds selected from reduced iron powder and atomized iron powder. Examples of the water retention agent include wood powder, vermiculite, diatomaceous earth, perlite, silica gel, alumina, water-absorbing resin, and the like. As the heat generating material 4, the composition used in a conventional disposable warmer may be used as it is, and there is no particular limitation.

[0037] As the heat generating material 4, materials other than those that generate heat by contact with air may be used. As the heat generating material 4, for example, a material that generates heat by being irradiated with microwaves by a microwave oven or the like (for example, ceramic powder such as ferrite, azuki beans, etc.) may be used.

[0038] (1.2.2) Bag body The bag body 2 is formed in a bag shape and has an accommodation space inside for containing the heat generating material 4. As shown in FIG. 3(A), the bag body 2 according to the present embodiment is formed flat and includes a front sheet portion 21 and a back sheet portion 22. In the bag body 2, the front sheet portion 21 and the back sheet portion 22 are joined by a joining portion 3, thereby forming an accommodation space inside.

[0039] As shown in FIG. 2, the bag body 2 according to the present embodiment has a width and a length. The end portion in the length direction of the bag body 2 according to the present embodiment is formed in an arc shape. However, the bag body 2 according to the present disclosure may be formed, for example, in a square shape when viewed from the front, a triangular shape when viewed from the front, a polygonal shape having five or more sides when viewed from the front, a perfect circular shape when viewed from the front, an elliptical shape when viewed from the front, etc., and there is no limitation on the shape.

[0040] (1.2.2.1) Front sheet portion As shown in FIG. 3(A), the front sheet portion 21 is a sheet-like portion that forms one surface of the bag body 2. The front sheet portion 21 according to the present embodiment is composed of a single sheet material. The front sheet portion 21 according to the present embodiment has flexibility. Thereby, the foot warmer 1 can be deformed along the user's foot 7.

[0041] From the viewpoints of strength and durability against the heat generation of the heat generating material 4, etc., it is preferable that a resin film is used for the front sheet portion 21 according to the present embodiment. As the resin used for the resin film, a thermoplastic resin is preferable. Examples of the thermoplastic resin include polyethylene, polypropylene, polyester, polyamide, polyurethane, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polycarbonate, ethylene-vinyl acetate copolymer, etc. These resins may be used alone or in combination of two or more.

[0042] Also, from the viewpoint of improving the touch feeling on the foot 7, it is preferable that a woven fabric or a non-woven fabric is provided outside the resin film for the front sheet portion 21.

[0043] Examples of the fibrous material for the woven or non-woven fabric include natural fibers such as cotton, hemp, silk, and paper, semi-synthetic fibers such as rayon and acetate, synthetic fibers such as nylon, vinylon, polyester, acrylic, polyethylene, polypropylene, polyvinyl chloride, and polybutylene terephthalate, and mixed fibers of these fibers. Among these fibrous materials, nylon, polyester, polypropylene, etc. are preferable from the viewpoint of providing a good touch. These fibrous materials may be used alone or in combination of two or more. The basis weight of the woven or non-woven fabric is not particularly limited as long as it can prevent the leakage of the heating material 4 to the outside of the bag body 2. As an example, it is 20 g / m 2 or more and 70 g / m 2 or less as exemplified below.

[0044] However, the front sheet portion 21 does not have to be a laminate of a resin film and a woven or non-woven fabric, and may be composed of a single resin film or a single woven or non-woven fabric. It may be configured.

[0045] The front sheet portion 21 according to the present embodiment has air permeability. In the front sheet portion 21 according to the present embodiment, since the resin film is a porous resin film or a resin film in which a plurality of holes (not shown) are formed, the front sheet portion 21 has a plurality of holes. Therefore, the front sheet portion 21 can ventilate the inside and outside of the bag body 2 through the plurality of holes. The plurality of holes may be uniformly formed over the entire surface of the front sheet portion 21 or may be densely formed in part. Further, the diameter of each hole may be such that it can suppress the leakage of the heating material 4 through the hole. As an example, it is 0.1 μm or more and 30 μm or less as exemplified. Further, the shape and number of the holes are not particularly limited. Since the felt temperature of the foot warmer 1 changes according to the ventilation amount of the bag body 2, the size, shape, and number of the holes are appropriately set in consideration of the felt temperature of the foot warmer 1 and the degree of suppressing the leakage of the heating material 4.

[0046] In addition, when a non-woven fabric is used alone as the front sheet portion 21, a plurality of holes do not have to be formed.

[0047] The front sheet portion 21 preferably has a certain moisture permeability. The moisture permeability of the front sheet portion 21 is preferably 300 g / (m 2 ·day) or more and 1000 g / (m 2 ·day) or less, more preferably 400 g / (m 2 ·day) or more and 900 g / (m 2 ·day) or less. However, the moisture permeability of the front sheet portion 21 is not particularly limited.

[0048] (1.2.2.2) Back sheet portion The back sheet portion 22 is a sheet-like portion that forms the surface opposite to the front sheet portion 21 in the bag body 2. The back sheet portion 22 according to the present embodiment is composed of a single sheet material. The back sheet portion 22 according to the present embodiment has flexibility, similar to the front sheet portion 21.

[0049] For the back sheet portion 22, it is preferable that a resin film is used, similar to the front sheet portion 21. However, the back sheet portion 22 does not necessarily have to have the same structure and the same material as the front sheet portion 21. The back sheet portion 22 is preferably composed of a laminate of a resin film and a woven fabric or a non-woven fabric, similar to the front sheet portion 21, but is not limited thereto, and may be composed of a single resin film or a single woven fabric or non-woven fabric.

[0050] The back sheet portion 22 according to the present embodiment has air permeability. The back sheet portion 22 according to the present embodiment has a plurality of pores because the resin film is a porous resin film or a resin film having a plurality of holes (not shown), similar to the front sheet portion 21. However, the back sheet portion 22 does not necessarily have to have air permeability and may be airtight.

[0051] The thickness of each of the front sheet portion 21 and the back sheet portion 22 is not particularly limited, but for example, it is preferably 0.1 mm or more and 2.0 mm or less. Thereby, while the foot heater 1 can be made soft and easily conformable to the sole 71, a certain strength can be ensured such that it can withstand continuous stepping by the sole 71.

[0052] The back sheet portion 22 preferably has a certain moisture permeability, similar to the front sheet portion 21. The moisture permeability of the back sheet portion 22 is preferably 300 g / (m 2 ·day) or more and 1000 g / (m 2 ·day) or less, more preferably 400 g / (m 2 ·day) or more and 900 g / (m 2 ·day) or less. However, the moisture permeability of the back sheet portion 22 is not particularly limited.

[0053] The foot heater 1 according to the present embodiment includes an anti-slip portion 23. The anti-slip portion 23 suppresses displacement that may occur between the foot heater 1 between the user's foot 7 and the shoe 8. The anti-slip portion 23 according to the present embodiment is constituted by a plurality of small protrusions 231 formed on the back sheet portion 22. In the present embodiment, the plurality of small protrusions 231 are uniformly formed over the entire surface (outer surface) of one side of the back sheet portion 22, but in the present disclosure, they may be formed in at least a partial region.

[0054] The small protrusions 231 are constituted by, for example, rubber or acrylic resin. However, the anti-slip portion 23 may be implemented by printing a foaming ink having an anti-slip function on the back sheet portion 22. Further, the anti-slip portion 23 may be formed not on the back sheet portion 22 but on the front sheet portion 21, or may be formed on both the back sheet portion 22 and the front sheet portion 21.

[0055] In addition, in the foot warmer 1 according to the present disclosure, an adhesive layer may be provided instead of the anti-slip portion 23. The adhesive layer is provided on either the back sheet portion 22 or the front sheet portion 21. Thereby, the foot warmer 1 may be used by being attached to the user's foot 7, or may be used by being attached to the shoe 8 (for example, the insole 81).

[0056] (1.2.2.3) Joint The joint 3 is a portion where the front sheet portion 21 and the back sheet portion 22 are joined. The joint 3 according to the present embodiment is configured by welding (heat sealing) a part of the front sheet portion 21 and a part of the back sheet portion 22. However, the joint 3 does not have to be welding, and may be realized by, for example, adhesion, sewing, pressure bonding, etc., or may be realized by a combination thereof. As shown in FIG. 2, the joint 3 includes an edge portion 31 and an intermediate portion 32.

[0057] The edge portion 31 is a portion formed along the outer peripheral portion of the bag body 2 among the joint 3, and is a portion where the outer peripheral portions of the front sheet portion 21 and the back sheet portion 22 are joined. The edge portion 31 according to the present embodiment is continuous over the entire outer circumference of the bag body 2. The width dimension of the edge portion 31 is not particularly limited, but is preferably, for example, 1 mm or more and 10 mm or less, and more preferably 3 mm or more and 7 mm or less. The edge portion 31 according to the present embodiment is formed with substantially the same width dimension over the entire length.

[0058] The edge portion 31 according to the present embodiment includes a pair of first straight portions 315 formed along the length direction, a second straight portion 316 formed along the width direction, and an arc-shaped portion 317 connecting the pair of first straight portions 315. The pair of first straight portions 315 are formed substantially linearly and are parallel to each other in the present embodiment.

[0059] The middle part 32 is a part of the joint part 3 that is formed inside the edge part 31 and away from the edge part 31. The size of the middle part 32 according to this embodiment is not particularly limited, as long as it is not connected to the edge part 31, and as long as the heating material 4 is arranged between it and the edge part 31. In the foot heater 1 according to this embodiment, the middle part 32 constitutes the heating material exclusion part 5. The heating material exclusion part 5 will be described in detail in the following "(1.2.2.4) Heating material exclusion part".

[0060] As shown in FIG. 2, the middle part 32 according to this embodiment is formed in a rectangular shape when viewed from the front. However, the middle part 32 according to the present disclosure may be formed, for example, in a circular shape when viewed from the front, a polygonal shape with five or more sides when viewed from the front, an oval shape (including an elliptical shape) when viewed from the front, a star shape when viewed from the front, a heart shape when viewed from the front, etc.

[0061] (1.2.2.4) Heating material exclusion part The heating material exclusion part 5 is a part where the heating material 4 is excluded when the heating surface 6 is viewed from the front. In this imp The heating material exclusion part 5 according to this embodiment is a part where the heating material 4 does not exist inside the edge part 31 of the bag body 2. As described above, the heating material exclusion part 5 according to this embodiment is constituted by the middle part 32. The outer peripheral part of the heating material exclusion part 5 forms a partition part 51, and due to the existence of the partition part 51, in the foot heater 1, the temperature distribution of the heating surface 6 can be controlled.

[0062] The heating material exclusion part 5 according to this embodiment is not limited in shape and size when viewed from the front, but is preferably, for example, 0.1% or more and 20% or less, more preferably 0.25% or more and 10% or less, and still more preferably 1% or more and 5% or less with respect to the area of the heating surface 6 (when there are a plurality of heating surfaces 6, the area of each heating surface 6).

[0063] The heating material exclusion part 5 includes a partition part 51 and an inner part 52 surrounded by the partition part 51. The partition part 51 is configured to surround a range of the heating surface 6 and prevents the conduction of heat from the outside to the inside of the partition part 51. In this embodiment, the partition part 51 and the inner part 52 are integrated and no boundary appears, but a boundary may appear.

[0064] The partition part 51 according to this embodiment is a frame-shaped part formed by joining the front sheet part 21 and the back sheet part 22. The "surrounding a range of the heat generating surface 6" as referred to in the present disclosure may be a closed partition that surrounds a range on the heat generating surface 6 over the entire circumference, or may be a partition with a part released such as a U-shape or a C-shape, for example. The joining of the front sheet part 21 and the back sheet part 22 may be realized by, for example, heat sealing, adhesion, sewing, crimping, or the like. In addition to being formed by joining the front sheet part 21 and the back sheet part 22, the partition part 51 may be formed of a cylindrical member with a low thermal conductivity, and the cylindrical member may be interposed between the front sheet part 21 and the back sheet part 22 so as to surround a range of the heat generating surface 6. Further, the partition part 51 may be formed of a solid member with a low thermal conductivity, and the solid member may be interposed between the front sheet part 21 and the back sheet part 22.

[0065] The inner part 52 is the part surrounded by the partition part 51 and is located in the same plane as the partition part 51. The inner part 52 according to this embodiment is formed by joining the front sheet part 21 and the back sheet part 22 in the same manner as the partition part 51, and is non-penetrating in the thickness direction of the heating element 1. The heat generating material exclusion part 5 may not include the inner part 52, and the part of the bag body 2 that contacts the inner part 52 may be a through hole. However, in the heating element 1 according to this embodiment, compared with the case where the inner part 52 is a through hole, it is advantageous in that it can suppress the temperature from dropping too much at the heat generating material exclusion part 5 on the heat generating surface 6.

[0066] In order to control the temperature distribution of the heat generating surface 6 by the presence of the partition part (heat generating material exclusion part 5), for example, it is performed as follows.

[0067] When trying to lower the maximum temperature of the heat generating surface 6 of the foot heating element without the partition part 51 (heat generating material exclusion part 5) to a predetermined temperature and increase the area of the high temperature region including the lowered maximum temperature, a heat generating material exclusion part 5 (here, the intermediate part 32) is provided at the center of the heat generating surface 6 ("reference heat generating surface 6" and "reference partition part (heat generating material exclusion part 5)").

[0068] When trying to further lower the maximum temperature with respect to the reference heat - generating surface 6, the partition portion 51 (heating - element exclusion portion 5) of the reference is set to be larger. Here, "setting the partition portion 51 (heating - element exclusion portion 5) to be larger" means setting the size of the partition portion 51 (the area of the heating - element exclusion portion) in the front view to be larger than that of the reference partition portion 51 (the reference heating - element exclusion portion 5).

[0069] When trying not to lower the maximum temperature to the reference heat - generating surface 6, the partition portion 51 (heating - element exclusion portion 5) of the reference is set to be smaller. Here, "setting the partition portion 51 (heating - element exclusion portion 5) to be smaller" means setting the size of the partition portion 51 (the area of the heating - element exclusion portion 5) in the front view to be smaller than that of the reference partition portion (the reference heating - element exclusion portion 5).

[0070] Also, when trying to lower the maximum temperature of the heat - generating surface 6 and position the high - temperature region on one - end side in the length direction, for example, the partition portion 51 (heating - element exclusion portion 5) may be formed on the other - end side of the centroid 9 of the heat - generating surface 6 in the length direction. On the other hand, when trying to lower the maximum temperature of the heat - generating surface 6 and position the high - temperature region on one - end side in the width direction, for example, the partition portion 51 (heating - element exclusion portion 5) may be formed on the other - end side of the centroid 9 of the heat - generating surface 6 in the width direction.

[0071] Also, depending on the shape or size of the partition portion 51 (the shape or area of the heating - element exclusion portion 5), the ratio of the high - temperature region in the whole area changes, so the area of the high - temperature region can be adjusted while maintaining the position of the high - temperature region.

[0072] In this way, in the heating element 1 according to the present embodiment, by forming the partition portion 51 (heating - element exclusion portion 5) so as to surround the centroid 9 of the heat - generating surface 6 or so as to surround a range of the heat - generating surface 6, the maximum temperature of the heat - generating surface 6 can be lowered to suppress local high - temperature rise, and the area of the high - temperature region can be increased to enhance the uniformity of the temperature distribution. Moreover, by changing the shape or area of the partition portion 51, it is also possible to obtain the target temperature distribution.

[0073] Furthermore, in the foot warmer 1 according to the present embodiment, since the position of the high-temperature region can be changed according to the position of the partition portion 51 (heating element exclusion portion 5), on the heating surface 6, the maximum temperature can be lowered and the high-temperature region can be positioned at a desired position.

[0074] (2) Operational effects As described above, in the temperature control method and the foot warmer 1 according to the present embodiment, the partition portion 51 is provided so as to surround a range on the heating surface 6 when viewed from the front, and the heat conduction from the outside of the partition portion 51 to the inside of the partition portion 51 is blocked.

[0075] According to this aspect, on the heating surface 6 of the foot warmer 1, the maximum temperature can be lowered to suppress a local high temperature rise, and the position of the high-temperature region can be changed. Therefore, for example, while arranging the foot warmer 1 at a well-fitting position, it is also possible to set the heating surface 6 so that the high-temperature region is located at a portion of the user's foot 7 that is particularly prone to getting cold. Further, the heating material 4 enclosed in the bag body 2 is prevented from moving by the heating element exclusion portion 5. For this reason, in the foot warmer 1 according to this aspect, the heating material 4 can be made less likely to shift inside the bag body 2.

[0076] Here, by forming the partition portion 51 so as to surround the centroid 9 of the heating surface 6, the maximum temperature decreases and the high-temperature region increases, so that the temperature distribution can be made uniform and the foot can be warmed over a wide range. On the other hand, by forming the partition portion 51 at a position biased toward one end side in the length direction of the bag body 2, the maximum temperature decreases and the high-temperature region moves from the central portion in the length direction of the bag body 3, so that, for example, the toes (fingertips) can be targeted for warming.

[0077] Further, since the partition portion 51 is formed by the exclusion of the heating material 4, heat generation in the partition portion 51 is suppressed. Therefore, on the heating surface 6 of the foot warmer 1, the maximum temperature can be lowered, the area of the high-temperature region can be increased, and a decrease in the average temperature of the heating surface 6 can be suppressed.

[0078] In addition, since the heat-generating material is also excluded from the inner part (inner part 52) of the partition part 51, the maximum temperature can be further lowered on the heat-generating surface 6 of the heating element 1.

[0079] In addition, the partition part 51 is configured by joining the front sheet part 21 and the back sheet part 22, and thereby is configured to exclude the heat-generating material 4. Therefore, the foot heating element 1 can be efficiently manufactured.

[0080] In addition, by changing the size and / or shape of the partition part 51, the temperature distribution of the heat-generating surface 6 can be controlled, so that the temperature distribution of the heat-generating surface 6 can be made closer to the target temperature distribution.

[0081] (3) Modification The above embodiment is merely one of various embodiments of the present disclosure. The embodiment can be variously modified according to design and the like as long as the object of the present disclosure can be achieved. Hereinafter, modification examples of the embodiment will be listed. The modification examples described below can be applied in appropriate combinations.

[0082] In the above embodiment, the heat-generating material exclusion part 5 is constituted by one intermediate part 32, but it may be constituted by two or more intermediate parts 32.

[0083] In the above embodiment, the heat-generating surface 6 is rectangular in a front view, but in the present disclosure, the heat-generating surface 6 is not limited to a rectangular shape, and may be formed, for example, in an oval shape (including an elliptical shape), a heart shape, a polygonal shape with five or more sides, or the like.

[0084] In the above embodiment, the foot heating element 1 is disposed between the user's sole 71 and the insole 81 of the shoe 8, but in the present disclosure, it may be disposed between the instep of the foot 7 and the shoe 8 or between the side surface of the foot 7 and the shoe 8.

[0085] In the present disclosure, expressions accompanied by "substantially", such as "substantially rectangular", may be used. For example, "substantially rectangular" means being substantially "rectangular", and includes not only being strictly "rectangular", but also shapes that can be recognized as rectangular when roughly looking at the shape. The same applies to other expressions accompanied by "substantially".

[0086] In the present disclosure, expressions that distinguish between "end part" and "end", such as "front end part" and "front end", are used. For example, "front end part" means a part having a certain range including the "front end". The same applies to other expressions accompanied by "end part".

[0087] (4) Examples Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to the following examples.

[0088] (4.1) Test 1 As Test 1, a test was conducted to confirm the intended effect on a heating element in which a partition part (heating material exclusion part) was formed so as to surround the centroid of the heating surface. As Examples 1 to 3, heating elements having a heating material exclusion part were manufactured, and as a comparative example, a heating element having no heating material exclusion part was manufactured. The temperature of the heating surface during heating was photographed by thermography, and the temperature distributions were compared.

[0089] As the heating elements according to Examples 1 to 3, as shown in FIGS. 4(A) to 4(C), heating elements having a heating surface formed in a substantially rectangular shape, with the length dimension E (longest part) of the heating surface being 116 mm and the width dimension W of the heating surface being 81 mm, were manufactured. Also, as a comparative example, a heating element having a heating surface formed in a substantially rectangular shape, with the length dimension E (longest part) of the heating surface being 116 mm and the width dimension W of the heating surface being 81 mm, was manufactured. In the heating elements according to Examples 1 to 3 and the comparative example, the heating material and the material of the bag body were the same as those in the above-described embodiment, and all were commonly used. Also, the amount of the heating material for each of Examples 1 to 3 and the comparative example was set to 37 g, making all of them have the same weight.

[0090] As the heating element according to Example 1, as shown in Fig. 4(A), at the center of the heating surface (that is, at the position where E1 = 58 mm and W1 = 40.5 mm), a heat seal portion was formed as a heating element exclusion portion. The heat seal portion was a square with a side length H1 = 10 mm.

[0091] As the heating element according to Example 2, as shown in Fig. 4(B), at the center of the heating surface, a heat seal portion was formed as a heating element exclusion portion. The heat seal portion was a square with a side length H2 = 20 mm.

[0092] As the heating element according to Example 3, as shown in Fig. 4(C), at the center of the heating surface, a heat seal portion was formed as a heating element exclusion portion. The heat seal portion was a square with a side length H3 = 30 mm.

[0093] The results of photographing Examples 1, 2, 3 and the comparative example side by side using thermography are shown in Fig. 5. Also, from the results of photographing with thermography, the area in each temperature range was calculated, and the relationship between each temperature range and the area ratio to the whole in that temperature range is shown in Table 1-1. Also, the area ratios in the high temperature range (the temperature range where the maximum temperature is -5 °C or higher and the maximum temperature or lower) extracted from Table 1 are shown in Table 1-2.

[0094] Fig. 6 shows Table 1-1 graphically. In the graph, the vertical axis is the area ratio (%), and the horizontal axis is the temperature (°C).

[0095] Also, for each of Examples 1, 2, 3 and the comparative example, the maximum temperature was extracted from Table 1-1, and the difference in the maximum temperature between the comparative example and Examples 1, 2, 3 was calculated. Furthermore, the average temperature on the heating surface of each of Examples 1, 2, 3 and the comparative example was calculated, and the difference in the average temperature between the comparative example and Examples 1, 2, 3 was calculated. The results are shown in Table 1-3.

Table 1-1

Table 1-2

Table 1-3

[0096] As can be seen from FIG. 5, in the comparative example, a white portion indicating a high temperature clearly exists thickly at the center of the heat generating surface, but in the heating elements according to Examples 1 to 3, the white portion is thinner than that in the comparative example. Also, as can be seen from Table 1-1, Table 1-2, and FIG. 6, the heating elements according to Examples 1 to 3 have a maximum temperature on the heat generating surface that is about 1 to 3 ° C lower than that of the comparative example, and the area ratio of the high temperature region is about 17 to 25% larger. That is, the heating elements according to Examples 1 to 3 can lower the maximum temperature and increase the area of the high temperature region on the heat generating surface compared to the comparative example. That is, according to the heating elements according to Examples 1 to 3, it is possible to suppress a local high temperature rise by lowering the maximum temperature, and it is possible to improve the uniformity of the temperature distribution by increasing the area of the high temperature region including the lowered maximum temperature.

[0097] Also, as can be seen from Table 1-2, compared with the heating element according to Example 2, the heating element according to Example 3 has a lower maximum temperature on the heat generating surface, and the heating element according to Example 1 has a higher maximum temperature on the heat generating surface. That is, it was found that the maximum temperature on the heat generating surface can be controlled by changing the area of the partition portion (heating material exclusion portion).

[0098] Also, as can be seen from Table 1-3, in the heating elements according to Examples 1 and 2, the difference in the maximum temperature is 1.3 to 2 ° C compared to the comparative example, while the difference in the average temperature is 0.28 to 0.85 ° C. Also, in the heating element according to Example 3, the difference in the maximum temperature is 3.5 ° C compared to the comparative example, while the difference in the average temperature is 1.72 ° C. That is, in the comparison between the heating elements according to Examples 1, 2, and 3 and the comparative example, the decrease width of the average temperature is smaller than the decrease width of the maximum temperature. That is, by forming the partition portion (heating material exclusion portion) at the center portion of the heat generating surface, the maximum temperature can be lowered while suppressing the decrease in the average temperature of the heat generating surface.

[0099] (4.2) Test 2 Next, as Test 2, a test was conducted to confirm the effect of a heating element in which the partition section (heating material exclusion section) was formed at a position deviated from the centroid of the heating surface.

[0100] As Examples 4 and 5, a heating element having a heating material exclusion section was manufactured, and as a Comparative Example, a heating element having no heating material exclusion section was manufactured. The temperature of the heating surface during heating was photographed by thermography, and the temperature distributions were compared.

[0101] As the heating elements according to Examples 4 and 5, as shown in FIGS. 7(A) and 7(B), a heating element was manufactured in which the heating surface was formed in a substantially rectangular shape, the length dimension E (longest part) of the heating surface was 116 mm, and the width dimension W of the heating surface was 81 mm. Further, as a Comparative Example, a heating element was manufactured in which the heating surface was formed in a substantially rectangular shape, the length dimension E (longest part) of the heating surface was 116 mm, and the width dimension W of the heating surface was 81 mm. In the heating elements according to Examples 4 and 5 and the Comparative Example, the heating material and the material of the bag body were the same as those in the above embodiment, and all were commonly used. Also, the amount of the heating material in each of Examples 4 and 5 and the Comparative Example was set to 37 g, and all had the same weight.

[0102] As the heating element according to Example 4, as shown in FIG. 7(A), in the length direction, at a position E1 = 29 mm from one end of the heating surface and at the center W1 = 40.5 mm in the width direction, a heat seal section was formed as the heating material exclusion section. The heat seal section was a square with a side H1 = 10 mm.

[0103] As the heating element according to Example 5, as shown in FIG. 7(B), in the length direction, at a position E1 = 29 mm from one end of the heating surface and at the center W1 = 40.5 mm in the width direction, a heat seal section was formed as the heating material exclusion section. The heat seal section was a square with a side H2 = 20 mm.

[0104] Examples 4 and 5 and the comparative example were photographed side by side using thermography, and the results of coloring according to the temperature range are shown in FIG. 8. Also, from the results of photographing with thermography, the area in each temperature range was calculated, and the relationship between each temperature range and the area ratio to the whole in that temperature range is shown in Table 2. Further, FIG. 9 shows a graph of Table 2. In the graph, the vertical axis represents the area ratio (%) and the horizontal axis represents the temperature (°C).

Table 2

[0105] As can be seen from FIG. 8, in the comparative example, the high-temperature region spreads to the central part, whereas in the heating elements according to Examples 4 and 5, the high-temperature region is located on the side opposite to the partition part (heating element exclusion part) rather than the center of the heating surface in the length direction. Therefore, it was found that the position of the high-temperature region moves according to the position of the partition part (heating element exclusion part). Also, as can be seen from the graph of FIG. 9 and Table 2, in the heating elements according to Examples 4 and 5, the maximum temperature is lower than that of the comparative example.

[0106] Therefore, in the heating elements according to Examples 4 and 5, the maximum temperature of the heating surface can be lowered and the high-temperature region can be moved compared to the comparative example. That is, according to the heating elements according to Examples 4 and 5, the maximum temperature can be lowered to suppress a local high temperature rise, and the position of the high-temperature region can be controlled.

[0107] Also, as can be seen from FIG. 9, in Example 5, the area of the high-temperature region is smaller than that in Example 4. That is, considering together with FIG. 8, it was found that the area of the high-temperature region on the heating surface can be adjusted by changing the size of the partition part (heating element exclusion part) while maintaining the position of the high-temperature region.

Explanation of Reference Numerals

[0108] 1 Heating element for feet 2 Bag body 21 Front sheet part 22 Back sheet part 32 Edge part (outer peripheral part) 4 Heat-generating material 51 Compartment section 52 Inner part (the part inside the compartment section) 6 Heat-generating surface

Claims

1. A temperature control method for controlling the temperature distribution of a heating surface of a foot warmer disposed between a user's foot and a shoe, comprising: The foot warmer includes: A heating material; A bag body that encloses the heating material and has a surface serving as a heating surface on at least one side; And is provided with; A partition portion that surrounds a range on the heating surface when viewed from the front, prevents heat conduction from the outside to the inside of the partition portion, and controls the temperature distribution of the heating surface; A method for controlling the temperature of the heating surface of a foot warmer.

2. The partition portion, when viewed from the front, prevents heat conduction from the outside to the inside of the partition portion by excluding the heating material; The method for controlling the temperature of the heating surface of the foot warmer according to Claim 1.

3. When viewed from the front, the heating material is also excluded from the inner portion of the partition portion; The method for controlling the temperature of the heating surface of the foot warmer according to Claim 2.

4. The bag body has a front sheet portion and a back sheet portion; The partition portion is formed by joining the front sheet portion and the back sheet portion, and is configured to exclude the heating material thereby; The method for controlling the temperature of the heating surface of the foot warmer according to Claim 2 or Claim 3.

5. The temperature distribution of the heating surface is controlled by changing the size or shape of the partition portion; the method for controlling the temperature of the heating surface according to any one of Claims 1 to 4.

6. A foot warmer disposed between a user's foot and a shoe, comprising: A heating material; A bag body that encloses the heating material and has a heating surface on one side; And is provided with; The bag body is formed with a partition portion that surrounds a range on the heating surface and prevents heat conduction from the outside to the inside thereof; A foot warmer.

7. The bag body has a front sheet portion and a back sheet portion; The partition portion is formed by excluding the heating material from between the front sheet portion and the back sheet portion; The foot warmer according to Claim 6.

8. When viewed from the front, the heating material is also excluded from the inner portion of the partition portion; The foot warmer according to Claim 7.

9. The bag body has a front sheet portion and a back sheet portion; The partition portion is formed by joining the front sheet portion and the back sheet portion, and is configured to exclude the heating material thereby; The foot warmer according to any one of Claims 6 to 8.

Images