Patent Publication Number: US-2020275722-A1

Title: Helmet and temperature regulation system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Japanese Patent Application No. 2017-198633 filed on Oct. 12, 2017, the entire contents of which are incorporated herein by reference. 
     TECHNICAL FIELD 
     This disclosure relates to helmets and temperature regulation systems. 
     BACKGROUND 
     A helmet is known as a protector to protect a head of a wearer. Further, a helmet with a cooling system is proposed to improve comfort of a wearer. For example, in a helmet disclosed in Patent Literature (PTL) 1, a cooling system using Peltier elements is disposed at a position corresponding to the back of a head of a wearer. 
     CITATION LIST 
     Patent Literature 
     PTL 1: JP2006-016714A 
     SUMMARY 
     A helmet according to an embodiment has an outer shell. The helmet has a buffer disposed inside the outer shell, a first flow channel positioned between a head of a wearer of the helmet and the buffer, and a second flow channel positioned in a groove formed in the buffer or at a portion where the buffer is partially absent. In the helmet, a heating medium containing at least partially a liquid flows through the first flow channel and the second flow channel. 
     A temperature regulation system according to an embodiment has the above described helmet and at least one of a biological information sensor and an environmental information sensor, and regulates a temperature of the heating medium on the basis of at least one of a temperature related to the wearer detected by the biological information sensor and a temperature related to the helmet detected by the environmental information sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1A  is a diagram illustrating an exterior view of a helmet according to an embodiment; 
         FIG. 1B  is a diagram illustrating an exterior view of a helmet according to an embodiment; 
         FIG. 2  is a cross-sectional view illustrating an internal structure of the helmet according to an embodiment; 
         FIG. 3  is a diagram illustrating a first flow channel in  FIG. 2 ; 
         FIG. 4A  is an enlarged view of a part of a cross-sectional view illustrated in  FIG. 2 ; 
         FIG. 4B  is an enlarged view of a part of a cross-sectional view illustrated in  FIG. 2 ; 
         FIG. 4C  is an enlarged view of a part of a cross-sectional view illustrated in  FIG. 2 ; 
         FIG. 5  is a cross-sectional view of an internal structure of a helmet according to another embodiment; 
         FIG. 6  is a functional block diagram illustrating a schematic configuration of the helmet according to an embodiment; 
         FIG. 7A  is a diagram illustrating an exterior view of a variation of the helmet according to an embodiment; and 
         FIG. 7B  is a diagram illustrating an exterior view of a variation of the helmet according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     It would be very advantageous if a helmet appropriately protects a head of a wearer and inside the helmet can be regulated to a comfortable temperature while being worn. This disclosure relates to a helmet and a temperature regulation system that realize a good temperature regulation while keeping a wearer safe. According to a helmet and a temperature regulation system according to an embodiment, a good temperature regulation can be realized while keeping a wearer safe. An embodiment will be described in detail below with reference to drawings. A helmet according to this embodiment may be one worn by an occupant(s) of various types of vehicles including, for example, two-wheel vehicles such as motorcycles and four-wheel vehicles such as racing cars. However, a helmet according to this embodiment is not limited to the use of a helmet by an occupant. For example, a helmet according to this embodiment may be used for various purposes such as one worn by workers worked at a factory for safety. The helmet according to this embodiment may be used for any purpose for protecting mainly a head of a wearer. 
     First, an external structure of the helmet according to an embodiment will be described. 
       FIGS. 1A and 1B  are diagrams each illustrating an exterior view of the helmet according to an embodiment.  FIG. 1A  is an exterior perspective view of a helmet  1  according to this embodiment and  FIG. 1B  is a diagram illustrating a state where the helmet  1  is worn on a head H of a wearer. 
     As illustrated in  FIG. 1A , the helmet  1  according to this embodiment has, for example, an outer shell (shell, hat body)  10 , a shield  12  and a shield screw  14  in appearance. As illustrated in  FIG. 1B , the helmet  1  according to this embodiment is worn, as with a general helmet, by a wearer of the helmet  1  with his/her head H inserted in the helmet  1  in the positive direction of the Z-axis as illustrated. 
     The outer shell  10  protects the head H of the wearer when an impact is applied to the helmet  1  from outside. The outer shell  10  may be made of a hard material so as to protect the wearer&#39;s head H. For example, the outer shell  10  may be made of a synthetic resin such as acrylonitrile butadiene styrene (ABS) resin, a composite material such as fiber-reinforced plastics (FRP) or a thermoplastic material such as polycarbonate (PC). In a normal use, the outer shell  10  may preferably be formed such that it wraps around the wearer&#39;s head H. Therefore, the outer shell  10  may be formed slightly larger than the wearer&#39;s head H. In this case, a buffer described later is placed in a gap between the outer shell  10  and the wearer&#39;s head H, and thus the wearer&#39;s head H is kept in safe. 
     The shield  12  covers at least a part of the wearer&#39;s eyes or face. The shield  12  can protect the wearer&#39;s eyes or face from ambient air, ambient temperature, foreign matters and the like. The shield  12  may be made of a hard material so as to protect eyes or face of the wearer. For example, the shield  12  may be made of a thermoplastic material such as polycarbonate (PC). The shield  12  can be configured to transmit a certain degree of visible light so as to ensure the vision of the wearer. The shield  12  may also be configured to slightly reduce the visible light transmission (while securing the vision) so as to mitigate glare felt by the wearer. Further, the shield  12  may be configured to reduce the ultraviolet (UV) transmission so as to protect the wearer eyes. 
     The shield screw  14  is used to attach the shield  12  to the outer shell  10 . The shield screw  14  may be a screw member made of a material with a certain degree of hardness such as metal or plastic, for example. The shield  12  may be rotatably attached to the outer shell  10  by the shield screw  14 . In this case, the shield  12  can rotate about the shield screw  14  in a certain rotation range. That is, in  FIGS. 1A and 1B , although the shield  12  is in a closed state (with respect to the outer shell  10 ), the shield  12  can be in an opened state (with respect to the outer shell  10 ), which enables the wearer of the helmet  1  to regulate the ambient air taken into the outer shell  10  during a ride, for example. 
     In  FIGS. 1A and 1B , the shield  12  and the shield screw  14  may be omitted according to the use of the helmet  1 . That is, the helmet  1  may be configured to have no shield  12  according to the use. In this embodiment, in order to keep the wearer safe, the helmet  1  may be configured to include the outer shell  10  that covers at least a part of the head of the wearer. 
     Hereinafter functions related to safety and temperature regulation of the helmet  1  according to this embodiment will be mainly described. Therefore, descriptions of the functions other than the above described functions are appropriately simplified or omitted. For example, a common helmet ventilation system including an air intake, an air duct and an air outlet is not illustrated in  FIGS. 1A and 1B . Such ventilation system can be adopted appropriately to the helmet  1  as needed. A strap (chin strap), etc. which helps the helmet  1  not to be easily detached from the head of the wearer is also omitted in  FIGS. 1A and 1B . 
       FIGS. 1A and 1B  illustrate what is called a full-face type helmet as the helmet  1  according to this embodiment. However, the helmet  1  according to this embodiment is not limited to the full-face type helmet illustrated in  FIGS. 1A and 1B . The helmet  1  according to this embodiment may be what is called a jet helmet or a half-hat helmet. The helmet  1  according to this embodiment may also be a helmet for works such as constructions or other types of helmet such as a hat-like helmet. 
     Subsequently, an internal structure of the helmet according to an embodiment will be described. 
       FIG. 2  is a cross-sectional view illustrating an internal structure of the helmet  1  according to an embodiment.  FIG. 2  illustrates a cross-sectional view approximately parallel to the YZ plane near the center of the X-axis direction of the helmet  1  illustrated in  FIGS. 1A and 1B . 
     As illustrated in  FIG. 2 , the helmet  1  has an outer shell  10 , a buffer  20 , a first flow channel  30 A and a second flow channels  30 B. As illustrated in  FIG. 2 , the outer shell  10  covers outside of the helmet  1 . The outer shell  10 , as the outer shell of the helmet  1 , may have strength enough to withstand an impact of a certain degree from outside. Further, as illustrated in  FIG. 2 , the buffer  20  is disposed inside the outer shell  10 . The buffer  20  may be made of styrofoam or an appropriate buffer material, for example. When an impact is applied to the outer shell  10  of the helmet  1 , the buffer  20  is crushed by the head of the wearer, and thus the impact applied to the wearer&#39;s head is reduced (absorbed). When the buffer  20  is disposed inside the outer shell  10 , it may be attached with a suitable material such as an adhesive, a double-faced tape or a hook and loop fastener and the like. 
     As illustrated in  FIG. 2 , in the helmet  1 , the first flow channel  30 A is positioned inside the buffer  20 . The first flow channel  30 A is formed into a relatively thin sheet.  FIG. 2  is a cross-sectional view of the helmet  1 . In  FIG. 2 , the cross-section of the sheet-like first flow channel  30 A is represented with a bold line. In  FIG. 2 , the sheet-like first flow channel  30 A is disposed so as to be directly attached to the buffer  20 . However, a shock absorber such as a cushioning material, for example, may be placed between the buffer  20  and the sheet-like first flow channel  30 A. The head of the wearer of the helmet  1  is positioned further inside the sheet-like first flow channel  30 A. That is, the first flow channel  30 A is positioned between the buffer  20  and the head of the wearer of the helmet  1 . When the first flow channel  30 A is disposed inside the buffer  20 , it may be attached with suitable materials such as an adhesive, a double-faced tape or a hook and loop fastener and the like. Suitable materials such as an adhesive, a double-faced tape or a hook and loop fastener and the like may also be used when a shock absorber such as a cushioning material is attached between the buffer  20  and the sheet-like first flow channel  30 A. 
       FIG. 3  is a diagram illustrating a plan view of the sheet-like first flow channel  30 A in  FIG. 2 .  FIG. 3  is a diagram illustrating at least a part of the first flow channel  30 A in an expanded and planar manner, viewed from the bottom of the helmet  1  (to the positive direction of the Z-axis) in  FIG. 2 . The first flow channel  30 A illustrated in  FIG. 3  may extend across the entire inside of the buffer  20  illustrated in  FIG. 2  or extend across at least a part of the inside of the buffer  20  illustrated in  FIG. 2 . Further, the first flow channel  30 A illustrated in  FIG. 2  may be formed of only one first flow channel  30 A, or of a plurality of first flow channels  30 A illustrated in  FIG. 3 . 
     The first flow channel  30 A may be made of a relatively hard material. However, the first flow channel  30 A is a member being directly or indirectly in contact with the head of the wearer of the helmet  1 . Therefore, it is better for safe fitting to the head of the wearer to make the first flow channel  30 A of a relatively flexible material, such as nylon, for example. 
     As illustrated in  FIG. 3 , a micro flow channel  32  forming the first flow channel  30 A may be made of polymer. Further, the micro flow channel  32  forming the first flow channel  30 A may be a micro-flow channel having a diameter of 200 μm or less, for example. In this case, the first flow channel  30 A formed in a sheet-like shape may have a thickness of from about 0.5 mm to about 2.0 mm, for example. As illustrated in  FIG. 3 , in the first flow channel  30 A, when a heating medium is passed through the micro flow channel  32 , an object in contact with or located near the first flow channel  30 A can be heated or cooled. In  FIG. 3 , as a simple example, the first flow channel  30 A is formed of one micro flow channel  32 , which includes only one inlet port and only one outlet port for the heating medium. However, the micro flow channel  32  forming the first flow channel  30 A may be provided with a plurality of inlet ports to appropriately merge each heating medium, or may be provided with a plurality of outlet ports to appropriately branch the heating medium. 
     The heating medium flowed through the micro flow channel  32  illustrated in  FIG. 3  may be any fluid such as gas or liquid, for example. The heating medium flowed through the micro flow channel  32  illustrated in  FIG. 3  may also be the above described fluid containing at least partially a solid such as particles, for example. In this embodiment, the heating medium flowed through the micro flow channel  32  may be a liquid such as water, for example, containing a predetermined amount of particles having a relatively high thermal conductivity, such as aluminum nitride, for example. In this context, an aluminum nitride to be contained in the heating medium may be fine particle with a diameter of tens of microns. In this manner, in the helmet  1  according to this embodiment, a heating medium containing at least partially a liquid flows through the first flow channel  30 A. In this manner, a heating medium is flowed through the first flow channel  30 A, which allows the head of the wearer in contact with or located near the first flow channel  30 A can be heated or cooled. 
     Further, as described above, when an impact is applied to the outer shell  10  of the helmet  1 , the buffer  20  is crushed by the head of the wearer. Also in this case, the first flow channel  30 A with flexibility allows itself to be deformed in response to a crushed buffer  20 . Therefore, when an impact is applied to the outer shell  10  of the helmet  1 , the helmet  1  reduces (absorbs) an impact applied to the head of the wearer. 
     As illustrated in  FIG. 2 , in the helmet  1  according to this embodiment, the buffer  20  is spread not all over inside the outer shell  10 . That is, the buffer  20  does not exist on some portions inside the outer shell  10 . As illustrated in  FIG. 2 , in the helmet  1  according to this embodiment, the second flow channel  30 B is positioned on portions where the buffer  20  does not exist inside the outer shell  10 . In the example illustrated in  FIG. 2 , a plurality of buffers  20  formed into a substantially elongated rectangular shape are disposed inside the outer shell  10 . The buffers  20  are slightly separated from each other, and the second flow channel  30 B is disposed in each gap between buffers  20 . 
     As illustrated in  FIG. 2 , the second flow channel  30 B may be formed into a tube shape. The second flow channel  30 B may have a diameter larger than that of the first flow channel  30 A, that is, 2 mm or larger, for example. In other words, the first flow channel  30 A may have a diameter that is smaller than that of the second flow channel  30 B. Further, the second flow channel  30 B may be made of a relatively hard material. However, the second flow channel  30 B may be formed of a relatively flexible material such as nylon, for example, so as to be deformed when the buffer  20  is crushed. In this manner, when an impact is applied to the outer shell  10  of the helmet  1 , the helmet  1  reduces (absorbs) an impact applied to the head of the wearer. That is, when an impact is applied to the outer shell  10  of the helmet  1 , the second flow channel  30 B does not hinder deformation of the buffer  20 . 
     As with the first flow channel  30 A, when heating medium is passed through the second flow channel  30 B, an object in contact with or located near the second flow channel  30 B can be heated or cooled. The heating medium flowed through the second flow channel  30 B may be the same as or different from the heating medium flowed through the first flow channel  30 A. In this embodiment, the heating medium flowed through the second flow channel  30 B may be obtained by adding a predetermined amount of particles having a relatively high thermal conductivity such as aluminum nitride, for example, to a liquid such as water, for example. 
     In this manner, in the helmet  1  according to this embodiment, a heating medium containing at least partially a liquid flows through the first flow channel  30 A and the second flow channel  30 B. In this manner, when a heating medium is flowed through the second flow channel  30 B, a portion in contact with or located near the second flow channel  30 B can be heated or cooled. In particular, the second flow channel  30 B can increase or decrease the temperature between the head of the wearer of the helmet  1  and the outer shell  10 , that is, the temperature inside the outer shell  10  of the helmet  1 . It is to be noted that the disclosed helmet may use only one of the first flow channel  30 A and the second flow channel  30 B. 
     As illustrated in  FIG. 2 , the diameter of the second flow channel  30 B may be smaller than the thickness of the buffer  20  (the length in the Z-axis direction). In this manner, each second flow channel  30 B can be completely embedded between buffers  20 . Thus, a risk of the second flow channel  30 B hindering the safety of the buffer  20  can be reduced. 
       FIG. 2  illustrates arrangement of the buffer  20  and the second flow channel  30 B. Therefore, a ratio of sizes of the members such as the buffer  20  and the second flow channel  30 B in  FIG. 2  does not correspond to the actual ratio of the sizes. For example, in  FIG. 2 , second flow channels  30 B may be disposed closer or farther apart from each other. The size, the number, and the position of each member may be changed appropriately depending on the required temperature regulating function of the helmet  1 . 
     Further, arrangement of the buffer  20  and the second flow channel  30 B is not limited to that illustrated in  FIG. 2 . In the example illustrated in  FIG. 2 , each second flow channel  30 B is disposed in a gap between buffers  20  that are completely separated from each other. That is, the positional relationship between the buffer  20  and the second flow channels  30 B in  FIG. 2  is as illustrated in  FIG. 4A . In  FIG. 4A , a part of the cross-section of the helmet  1  illustrated in  FIG. 2  is enlarged. In the example illustrated in  FIG. 4A , the second flow channel  30 B is disposed in a gap between buffers  20  that are completely separated from each other. Further, the second flow channel  30 B is disposed between the outer shell  10  and the first flow channel  30 A in the thickness direction inside the helmet  1 . As a variation of the configuration illustrated in  FIG. 4A , the second flow channel  30 B may be disposed so as to be in contact with at least one of the outer shell  10  and the first flow channel  30 A, for example. 
     Further, in this embodiment, the second flow channel  30 B is not limited to the configuration in which the second flow channel  30 B is positioned at a portion where the buffer  20  is partially absent ( FIGS. 2 and 4A ). For example, the buffer  20  is not separated into a plurality of portions, and a groove is formed in a part of the buffer  20 , and the second flow channel  30 B may be disposed along the groove. For example, as illustrated in  FIG. 4B , on a surface where the buffer  20  and the outer shell  10  are opposed to each other, a groove may be formed in the buffer  20  and the second flow channel  30 B may be disposed along the groove. Further, as illustrated in  FIG. 4C , for example, on a surface where the buffer  20  and the first flow channel  30 A are opposed to each other, a groove may be formed in the buffer  20  and the second flow channel  30 B may be disposed along the groove. In this manner, in this embodiment, the second flow channel  30 B may be positioned in a groove formed in the buffer  20  or in a portion where the buffer is partially absent. Moreover, in the example illustrated in  FIG. 4A , a space around the second flow channel  30 B (a gap between the buffers  20 ) may at least partially be filled with any cushion material and the like, for example. Any of the above described configurations may not significantly impair the function related to safety aspect of the buffer  20 . 
     Further, in this embodiment, the second flow channel  30 B is not limited to the configuration illustrated in  FIG. 2 . Many of the second flow channels  30 B illustrated in  FIG. 2  is configured to flow a heating medium through a channel along a surface nearly parallel to the ZX plane. However, in this embodiment, a path of the second flow channel  30 B may radially spread from near the ear of the wearer of the helmet  1 , as illustrated in  FIG. 5 . 
     Further, in each example illustrated in  FIGS. 2 and 5 , the path of the second flow channel  30 B near the top of the head of the wearer of the helmet  1  is disposed nearly parallel to the X-axis direction. However, in this embodiment, the path of the second flow channel  30 B is not limited to such arrangement. For example, the path of the second flow channel  30 B may be disposed nearly parallel or obliquely to the Y-axis direction near the top of the head of the wearer of the helmet  1 . Moreover, the path of the second flow channel  30 B may be disposed not only in one direction but also in a plurality of directions near the top of the head of the wearer of the helmet  1 . In this case, a plurality of the second flow channels  30 B may be merged or branched, or they may be crossed without being merged or branched. 
     The circulation pump  40  illustrated in  FIG. 2  circulates the above described heating medium through at least one of the first flow channel  30 A and the second flow channel  30 B. The circulation pump  40  circulates a liquid by rotating a motor, for example. As the circulation pump  40 , any pump such as a diaphragm-type liquid feed pump configured to allow a fluid such as a liquid to flow in and out to circulate may be adopted. In this embodiment, the circulation pump  40  to be adopted may be one that changes rotation number of the motor by adjusting the input current by current control, for example, so as to change the flow rate of a liquid to be circulated. 
     The circulation pump  40  may be disposed at any position inside or outside the outer shell  10  of the helmet  1 . In this case, the circulation pump  40  disposed may be a compact one. In  FIG. 2 , the circulation pump  40  is disposed inside the outer shell  10  of the helmet  1 . However, the circulation pump  40  may be disposed outside the outer shell  10  of the helmet  1 . 
       FIG. 2  illustrates, as an example, a configuration in which the circulation pump  40  flows a heating medium flowed out from any one of a plurality of the second flow channels  30 B into any one of the other second flow channels  30 B. In  FIG. 2 , a circulation pump configured to circulate a heating medium flowed through the first flow channel  30 A is not illustrated. In this context, the circulation pump  40  may also circulate the heating medium flowed through the first flow channel  30 A. In this case, an inlet port and an outlet port of the micro flow channel  32  illustrated in  FIG. 3  may be connected to the circulation pump  40 . Such connection aspect is not illustrated in  FIGS. 2 and 3 . Further, a circulation pump configured to circulate a heating medium flowed through the first flow channel  30 A may be provided separately from the circulation pump  40  illustrated in  FIG. 2 . In this case, the first flow channel  30 A is formed of a micro flow channel, and thus a circulation pump configured to circulate a heating medium flowed through the first flow channel  30 A may be a micro flow channel pump, for example. 
     A biological information sensor  50 A illustrated in  FIG. 2  may be various types of sensors such as a temperature sensor, a blood flow sensor, a pulse wave sensor and the like, for example. The biological information sensor  50 A may also be a heart rate sensor, a pulse sensor and the like. In this embodiment, the temperature of the heating medium flowed through at least one of the first flow channel  30 A and the second flow channel  30 B is regulated according to the biological information detected by the biological information sensor  50 A. The biological information sensor  50 A is not limited to a temperature sensor, a blood flow sensor and a pulse wave sensor, and may be a sensor configured to detect various kinds of information related to the wearer of the helmet  1 . Hereinafter an aspect in which the biological information sensor  50 A is a temperature sensor is described as a typical example. That is, hereinafter the biological information sensor  50 A detects a temperature related to the wearer of the helmet  1 . In this context, the temperature related to the wearer of the helmet  1  detected by the biological information sensor  50 A may be a temperature at any position (e.g. around ears of the wearer) of the head of the wearer of the helmet  1 , for example. 
     As illustrated in  FIG. 2 , the biological information sensor  50 A is disposed at a position inside the outer shell  10 , inside the buffer  20  or inside the first flow channel  30 A suitable to detect the biological information of the wearer of the helmet  1 . In an example illustrated in  FIG. 2 , the biological information sensor  50 A is disposed at a position behind the ear of the wearer of the helmet  1 . 
       FIG. 2  illustrates an example where only one biological information sensor  50 A is disposed behind the ear of the wearer of the helmet  1 . However, any number of biological information sensors  50 A may be disposed at any position of the helmet  1  according to various requirements and/or specifications. For example, the biological information sensor  50 A may be disposed in the helmet  1  such that it abuts or comes close to the forehead, the top, side and back of the head, the temple and the neck of the wearer of the helmet  1 . 
     In the helmet  1 , a portion that directly in contact with the wearer of the helmet  1  adheres to the skin of the wearer. Therefore, in the helmet  1 , when the biological information sensor  50 A is disposed at a portion that directly in contact with the wearer, the position of the biological information sensor  50 A that comes in contact with the wearer is almost fixed. In this manner, the biological information sensor  50 A can appropriately detect the biological information of the wearer of the helmet  1  under a stable state. 
     The environmental information sensor  50 B illustrated in  FIG. 2  may be various types of sensors such as a temperature sensor, a humidity sensor, an air pressure sensor and the like, for example. In this embodiment, the temperature of the heating medium flowed through at least one of the first flow channel  30 A and the second flow channel  30 B is regulated according to the environmental information detected by the environmental information sensor  50 B. The environmental information sensor  50 B is not limited to a temperature sensor, a humidity sensor, an air pressure sensor and the like, and may be a sensor configured to detect various kinds of information related to the helmet  1 . Hereinafter an aspect in which the environmental information sensor  50 B is a temperature sensor is described as a typical example. That is, hereinafter the environmental information sensor  50 B detects a temperature related to the helmet  1 . In this context, the temperature related to the helmet  1  detected by the environmental information sensor  50 B may be a temperature in the helmet  1 , in particular, a temperature between the outer shell  10  and the first flow channel  30 A. 
     As illustrated in  FIG. 2 , the environmental information sensor  50 B may be disposed between the outer shell  10  and the first flow channel  30 A. In the example illustrated in  FIG. 2 , the environmental information sensor  50 B is disposed between buffers  20 . In this manner, the environmental information sensor  50 B can detect the environmental information inside the helmet  1 . 
       FIG. 2  illustrates an example where only one environmental information sensor  50 B is disposed between two buffers  20 . However, any number of environmental information sensors  50 B may be disposed at any position in the helmet  1  according to various requirements and/or specifications. 
     Subsequently, a function of temperature regulation in the helmet  1  according to this embodiment will be described. 
       FIG. 6  is a functional block diagram illustrating a schematic configuration of the helmet  1 . In  FIGS. 1 to 5 , functional parts that are not required to be viewed from outside are appropriately omitted. In  FIG. 6 , functional parts that are necessary for the helmet  1  to regulate temperatures will be also described. 
     As illustrated in  FIG. 6 , the helmet  1  according to this embodiment has a first flow channel  30 A, a second flow channel  30 B, circulation pumps  40 A and  40 B, a biological information sensor  50 A, an environmental information sensor  50 B, a controller  60  and heat exchangers  70 A and  70 B. Explanation of the above described functional parts will be appropriately simplified or omitted. 
     As described above, the first flow channel  30 A may be formed of a micro flow channel, and the second flow channel  30 B may be formed into a tubular shape. The first flow channel  30 A is connected to the circulation pump  40 A, and the second flow channel  30 B is connected to the circulation pump  40 B. In  FIG. 2 , the helmet  1  has only one circulation pump  40 . On the other hand, in  FIG. 6 , the first flow channel  30 A and the second flow channel  30 B are connected to the circulation pump  40 A and the circulation pump  40 B, respectively. Hereinafter, when it is not necessary to distinguish the circulation pump between the circulation pump  40 A and the circulation pump  40 B, the circulation pump is simply referred to as the circulation pump  40 . 
     The controller  60  controls overall electrical functions of the helmet  1  including the temperature regulation function of the helmet  1 . 
     The helmet  1  may include at least one processor as the controller  60  to provide control and processing capability for performing various kinds of functions. According to various embodiments, at least one processor may be implemented as a single integrated circuit (IC) or a plurality of integrated circuits communicably connected to each other and/or a discrete circuit. At least one processor can be implemented according to various known techniques. 
     In one embodiment, a processor includes one or more circuits or units configured to implement one or more data calculation procedures or processes. For example, the processor may implement the functions described below by one or more processors, controllers, microprocessors, microcontrollers, application specific integrated circuits (ASIC), digital signal processors, programmable logic devices, field programmable gate arrays, any combinations of these devices or configurations, or combinations of other known devices or configurations. 
     In this embodiment, the controller  60  controls the circulation pumps  40 A and  40 B to control the flow rate of the heating medium flowed through the first flow channel  30 A and the second flow channel  30 B. 
     As described above, the biological information sensor  50 A detects the temperatures related to the wearer of the helmet  1  and sends the information of the detection results to the controller  60 . As described above, the environmental information sensor  50 B detects the temperatures related to the helmet  1  and sends the information of the detection results to the controller  60 . 
     In this embodiment, the controller  60  may regulate the temperature of the heating medium flowed through at least one of the first flow channel  30 A and the second flow channel  30 B on the basis of the temperature detected by the biological information sensor  50 A. Further, in this embodiment, the controller  60  may also regulate the temperature of the heating medium flowed through at least one of the first flow channel  30 A and the second flow channel  30 B on the basis of the temperature detected by the environmental information sensor  50 B. 
     The heat exchanger  70 A exchanges the heat of the heating medium flowed through the first flow channel  30 A, and the heat exchanger  70 B exchanges the heat of the heating medium flowed through the second flow channel  30 B. The heat exchangers  70 A and  70 B may employ Peltier element, for example, that has a heat exchange function. The heat exchanger  70 A cools or heats the heating medium flowed between the first flow channel  30 A and the circulation pump  40 A. In the same manner, the heat exchanger  70 B cools or heats the heating medium flowed between the second flow channel  30 B and the circulation pump  40 B. Hereinafter, when it is not necessary to distinguish the heat exchanger between the heat exchanger  70 A and the heat exchanger  70 B, the heat exchanger is simply referred to as the heat exchanger  70 . The heat exchanger  70  can allow the temperature of the heating medium flowed through the first flow channel  30 A or the second flow channel  30 B to escape to the temperature outside the helmet  1  or to the ambient air temperature. Conversely, the heat exchanger  70  can add the temperature outside the helmet  1  or the ambient air temperature to the temperature of the heating medium flowed through the first flow channel  30 A or the second flow channel  30 B. 
     There may be some cases where the temperature of the heating medium is desired to be cooled or heated in a relatively rapid manner depending on the temperature detected by the biological information sensor  50 A and/or the environmental information sensor  50 B. Therefore, in this embodiment, the controller  60  regulates the speed of cooling or heating the temperature of the heating medium by controlling at least one of the circulation pump  40  and the heat exchanger  70 . For example, when the heat exchanger  70  is operated with a large power and further the flow rate of the circulation pump  40  to circulate the heating medium is increased, the temperature of the heating medium can be cooled or heated steeply. Conversely, for example, when the operation power of the heat exchanger  70  is reduced and further the flow rate of the circulation pump  40  to circulate the heating medium is decreased, the temperature of the heating medium can be cooled or heated moderately. Further, when the temperature of the heating medium is cooled or heated moderately, the controller  60  may operate the circulation pump  40  and the heat exchanger  70  related to only either one of the first flow channel  30 A and the second flow channel  30 B. 
     In this manner, in this embodiment, the controller  60  controls at least one of the circulation pump  40  and the heat exchanger  70  to regulate the temperature of the heating medium flowed through at least one of the first flow channel  30 A and the second flow channel  30 B. 
     Specifically, for example, the controller  60  may control to reduce the temperature of the heating medium flowed through the first flow channel  30 A when the temperature related to the wearer of the helmet  1  is a predetermined first threshold (e.g. 37° C.) or more. On the other hand, for example, the controller  60  may control to increase the temperature of the heating medium flowed through the first flow channel  30 A when the temperature related to the wearer of the helmet  1  is a predetermined second threshold (e.g. 35° C.) or less. In this case, the threshold may be determined on the basis of the body temperature (normal body temperature) of the wearer of the helmet  1 . When the temperature is regulated in this manner, comfort of the wearer of the helmet  1  can be improved while reducing the influence of the ambient air temperature. 
     Further, for example, the controller  60  may control to reduce the temperature of the heating medium flowed through the second flow channel  30 B when the temperature related to the helmet  1  is a predetermined third threshold (e.g. 28° C.) or more. On the other hand, for example, the controller  60  may control to increase the temperature of the heating medium flowed through the second flow channel  30 B when the temperature related to the helmet  1  is a predetermined fourth threshold (e.g. 15° C.) or less. In this case, the threshold may be determined on the basis of the temperature of the environment (e.g. the ambient air temperature) in which the wearer of the helmet  1  is placed. When the temperature is regulated in this manner, comfort of the wearer of the helmet  1  can be improved while reducing the influence of the ambient air temperature. 
     When wearing a helmet, an exclusive suit (e.g. overalls), exclusive shoes (or exclusive boots) and the like to ride on a vehicle such as a motorcycle, for example, a wearer will be heavily armed. It is assumed therefore that the wearer will be uncomfortable with a lot of sweat especially in summer, for example. Conversely, when riding on a vehicle such as a motorcycle in the middle of winter, or when working in a freezing or refrigerating facility, it is assumed that the wearer feels uncomfortable with coldness even if the wearer is heavily armed. 
     Protective clothing or helmet equipped therein with air-conditioning function has been proposed. However, such protective clothing or helmet that has been proposed has a problem of upsizing, insufficient usability, difficulty in maintaining safety of the wearer, and the like. On the other hand, the helmet  1  according to this embodiment can be miniaturized compared to the existing helmet equipped with a fan, a water-cooled system and the like. 
     Further, the helmet  1  according to this embodiment cooperates with the biological information sensor, which enables temperature regulation in consideration of various situations. Therefore, the helmet  1  according to this embodiment provides comfort to the wearer of the helmet  1  and can reduce the risk for the wearer suffering from dehydration or heatstroke. Further, the helmet  1  according to this embodiment has the above described temperature regulating function and can ensure a configuration related to the safety of the wearer as well. Therefore, according to the helmet  1  of this embodiment, a good temperature regulation can be realized while keeping the wearer safe. 
     In the above described temperature regulation, the heating medium is controlled to be cooled or heated depending on the temperature detected by the biological information sensor  50 A and/or the environmental information sensor  50 B. Such control may be dynamically performed depending on the temperature detected on a steady basis or performed depending on the temperature detected at predetermined time intervals. 
     Further, if there is no predetermined change in the temperature detected by the biological information sensor  50 A and/or the environmental information sensor  50 B even after a predetermined time from the above-described temperature regulation, the controller  60  may control to inform a possibility of abnormality. For example, when no effect is seen in the temperature detected by the biological information sensor  50 A even after a temperature control is performed, and then a predetermined time (e.g. three minutes) is passed, the wearer of the helmet  1  is suspected to have a risk of heatstroke, for example. 
     In this case, the controller  60  may control such that the above described risk is informed as the information recognizable by the wearer of the helmet  1  such as sound, light, vibration and the like. In order to output a sound for informing the wearer, the helmet  1  may have a sound output unit such as a buzzer or a speaker, for example. In order to output light for informing the wearer, the helmet  1  may have a light emitting unit such as a light emitting diode (LED), for example. In order to output vibration for informing the wearer, the helmet  1  may have a vibrating unit such as a vibrator. 
     Further, as described above, when the wearer of the helmet  1  is suspected to be suffering from any risk, the controller  60  may control to output a notification to an external server or an external emergency unit that controls the health information of the wearer of the helmet  1 , for example. A communication unit having a function of wireless communication, for example, is provided to the inside or outside the controller  60  to output such notification. 
     Further, in the above described embodiment, the biological information sensor  50 A measures the temperature related to the wearer of the helmet  1 . However, in the helmet  1 , instead of or along with the biological information sensor  50 A, which is a temperature sensor, a sensor capable of detecting heart rate, pulse rate, pulse wave, blood flow rate and the like may be provided. In this manner, for example, when the wearer of the helmet  1  has an increase in pulse rate or a sudden decrease in blood flow rate, an appropriate temperature regulation can be performed or a notice can be given to the wearer and/or to an external server or an external emergency unit. 
     In the above described embodiment, all of the functions illustrated in  FIG. 6  are assumed to be provided inside or outside of the helmet  1 . However, the helmet  1  according to this embodiment is not limited to the above described configuration. Among the functions illustrated in  FIG. 6 , the first flow channel  30 A and the second flow channel  30 B are needed to be provided at least inside or outside the helmet  1  to regulate the temperature of the head of the wearer of the helmet  1 . On the other hand, among the functions illustrated in  FIG. 6 , the members other than the first flow channel  30 A and the second flow channel  30 B may be provided outside the helmet  1  being apart therefrom, or provided as a function part separate from the helmet  1 . 
     For example, the circulation pump  40  connected to at least one of the first flow channel  30 A and the second flow channel  30 B may be provided as an external function separated from the helmet  1 . In this case, at least one of the first flow channel  30 A and the second flow channel  30 B may be connected to the circulation pump  40  through a tube through which a heating medium is flowed. Further, in this configuration, the heat exchanger  70  may also be provided as an external function separate from the helmet  1 . In this case, the heat exchanger  70  may be disposed at any position of the tube connected between at least one of the first flow channel  30 A and the second flow channel  30 B and the circulation pump  40 . 
     Further, the controller  60  may also be provided as a separate function outside the helmet  1 , rather than inside the helmet  1 . In this case, the controller  60  may be connected to other functions such as the circulation pump  40  and the heat exchanger  70  wired or wireless. When the controller  60  communicates with the other functions wirelessly, a communication unit having a wireless communication function may be provided inside or outside the controller  60 . 
     When the controller  60  is provided outside the helmet  1  as a separate function, wired connection using a cable is no more needed if the controller  60  and at least a part of the other function is connected wirelessly. In this manner, the burden of connecting a cable can be avoided and a risk of breaking a wire caused by tangled wires can be avoided as well. In the above described embodiment, at least one of the biological information sensor  50 A and the environmental information sensor  50 B is assumed to be connected to the controller  60  wired. However, at least one of the biological information sensor  50 A and the environmental information sensor  50 B may be connected to the controller  60  wirelessly. 
     Further, when the controller  60  is provided outside the helmet  1  as a separate function, the controller  60  is not necessarily provided as a dedicated device. For example, when a two-wheeled vehicle or a four-wheeled vehicle driven by the wearer of the helmet  1  has a controller such as a computer, the computer may serve as the controller  60 . In this case, the helmet  1  does not need to have the controller  60 , and may have only a communicating unit configured to communicate with the controller  60 . Furthermore, when the controller  60  is provided outside the helmet  1  as a separate function, a cell phone or a smart phone carried by the wearer of the helmet  1  may serve as the controller  60 . In this case, when an application for controlling the helmet  1  is installed in a cell phone or a smart phone carried by the wearer of the helmet  1 , the temperature of the helmet  1  can be controlled. 
     As described above, the helmet  1  according to this embodiment can also be realized as an element included in the temperature regulation system. In this case, the temperature regulation system according to this embodiment includes the helmet  1 , at least one of the biological information sensor  50 A and the environmental information sensor  50 B and the controller  60 . In this case, the controller  60  regulates the temperature of the heating medium at least on the basis of the temperature related to the wearer of the helmet  1  detected by the biological information sensor  50 A and the temperature related to the helmet  1  detected by the environmental information sensor  50 B. 
     In  FIGS. 1A, 1B, 2 and 5 , what is called a full-face type helmet is illustrated as the helmet  1  according to this embodiment. However, the helmet  1  according to this embodiment is not limited to the full-face type. The helmet according to this embodiment may be a jet helmet  2  illustrated in  FIG. 7A  or a half-hat helmet  3  illustrated in  FIG. 7B . Further, the helmet according to this embodiment may be a helmet for works such as constructions or a helmet like a hat. The helmet according to this embodiment can adopt the above-described configuration as long as the helmet is a head protector having the outer shell  10 . 
     Although this disclosure has been described on the basis of the drawings and the examples, it is to be understood that various changes and modifications may be made easily on the basis of this disclosure by those who are ordinarily skilled in the art. Accordingly, such changes and modifications are included in the scope of the disclosure herein. For example, functions and the like included in each function, each component, each step and the like may be rearranged without logical inconsistency. A plurality of functions or steps can be combined into one or divided. Further, the above described each embodiment is not limited to one that faithfully implements each embodiment described and may be implemented by combining each feature or omitted a part thereof appropriately. 
     For example, the above described heat exchanger  70  is explained as an element such as a Peltier element, for example, that has a function of heat exchange. As a simpler configuration, a small fan may be provided as the heat exchanger  70 . The temperature of a heating medium flowed through the first flow channel  30 A and/or the second flow channel  30 B can be cooled by rotating a small fan with a motor and the like, for example, 
     REFERENCE SIGNS LIST 
     
         
         
           
               1  helmet 
               10  outer shell 
               12  shield 
               14  shield screw 
               20  buffer 
               30 A first flow channel 
               30 B second flow channel 
               32  micro flow channel 
               40  circulation pump 
               50 A biological information sensor (temperature sensor) 
               50 B environmental information sensor (temperature sensor) 
               60  controller 
               70  heat exchanger