Robot

Abstract

Provided is a robot that reduces a temperature rise in a space surrounded by an exterior member and has a soft exterior. The robot has an exterior member and a heat source disposed in a space surrounded by the exterior member. The thermal conductivity of the exterior member is 0.3 W / (m·K) or more. The compressive stress when the exterior member is compressed by 30% is 2.0 N / mm2 or less.

Description

robot

[0001] The present invention relates to a robot.

[0002] 2. Description of the Related Art Conventionally, robots that provide comfort to users by interacting with them have been known (see, for example, Patent Document 1).

[0003] Also disclosed is a robot having an exterior member that forms the outer surface, a heating element that is arranged in a space surrounded by the exterior member, a heat transfer unit that transfers heat from the heating element to the exterior member, and a heat transfer control unit that adjusts the amount of heat transfer between the heating element and the exterior member by operating the heat transfer unit (see, for example, Patent Document 2).

[0004] International Publication No. 2017 / 169826 Patent No. 6890207

[0005] From the perspective of providing a sense of comfort to the user through interaction with the robot, it is preferable for the exterior member to be made of a soft material such as resin or rubber. However, soft materials generally have low thermal conductivity. Therefore, if a heat source such as a processor or motor is placed in a space surrounded by an exterior member made of a soft material, the heat generated by the heat source is not dissipated, and the temperature in the space is likely to rise. As a result, components, mechanisms, electronic components, etc. placed in the space surrounded by the exterior member may be damaged or malfunction. On the other hand, the robot described in Patent Document 2 uses a material with high thermal conductivity for the exterior member, which makes it easy to reduce the temperature rise in the space surrounded by the exterior member. However, materials with high thermal conductivity, such as metal, are generally hard, so there is room for improvement in terms of providing a sense of comfort to the user through interaction with the robot.

[0006] An object of the present invention is to provide a robot that reduces the temperature rise in the space surrounded by an exterior member and has a soft exterior.

[0007] A robot according to one aspect of the present invention includes an exterior member and a heat source disposed in a space surrounded by the exterior member, wherein the exterior member has a thermal conductivity of 0.3 W / (m·K) or more, and a compressive stress of 2.0 N / mm when the exterior member is compressed by 30%. ２ The following is the result.

[0008] According to the present invention, it is possible to provide a robot that reduces the temperature rise in the space surrounded by the exterior member and has a soft exterior.

[0009] 1 is a schematic perspective view of a robot according to an embodiment. FIG. 2 is a schematic side view of a robot according to an embodiment. FIG. 3 is a schematic cross-sectional view along line III-III in FIG. 2. FIG. 4 is a diagram schematically illustrating the configuration of a vital sensor according to an embodiment. FIG. 5 is a block diagram illustrating the hardware configuration of a control unit according to an embodiment. FIG. 6 is a block diagram illustrating the functional configuration of a control unit according to an embodiment. FIG. 7 is a schematic cross-sectional view of an example of a composite material according to an embodiment. FIG. 8 is a schematic cross-sectional view of another example of a composite material according to an embodiment. FIG. 9 is a diagram illustrating measurement positions in a composite material of an exterior member according to an embodiment by energy dispersive X-ray spectroscopy using an ultrahigh resolution field emission scanning electron microscope. FIG. 10 is a diagram illustrating the results of observing a cross section of a composite material in an exterior member according to Example 1 using a scanning electron microscope. FIG. 11 is a diagram illustrating the relationship between the restorability and strain rate of an exterior member when unloading.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same components are given the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0011] The embodiments described below are illustrative of robots that embody the technical concepts of the present invention, and are not intended to limit the present invention to the following embodiments. The dimensions, materials, shapes, relative positions, and other details of the components described below are intended for illustrative purposes only, unless otherwise specified, and are not intended to limit the scope of the present invention. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity.

[0012] For ease of understanding, in this specification, in the robot according to the embodiment, the vertically upper side when the user holds the robot is referred to as "up" and the vertically lower side is referred to as "down." The up and down directions are collectively referred to as the up-down direction. The direction perpendicular to the up-down direction is referred to as the horizontal direction. Of the horizontal directions, in the robot according to the embodiment, the direction in which the user is positioned when the user holds the robot is referred to as the "front," and the direction opposite to the direction in which the user is positioned is referred to as the "rear." The forward and rearward directions are collectively referred to as the front-to-rear direction. Of the horizontal directions, the direction perpendicular to the front-to-rear direction is referred to as the lateral direction. Of the lateral directions, the left side as viewed from the robot according to the embodiment is referred to as the "left," and the right side as viewed from the robot according to the embodiment is referred to as the "right." However, in this specification and claims, terms indicating specific directions or positions (e.g., "up," "down," "side," "right," "left," and other terms including these terms) only need to indicate the relative positional relationship, and the orientation of the robot according to the embodiment when in use is not limited to the above. In addition, in the embodiment, the orthogonal angle may have an error of ±10° relative to 90°.

[0013] The robot according to this embodiment is a robot capable of communicating with a user. The term "user" refers to the person who uses the robot. Typical examples of users include working people living alone, seniors whose children have left home, and frail elderly people who require home medical care. Note that the term "user" may include not only the user of the robot, but also people who simply come into contact with the robot, such as the robot's administrator.

[0014] Communication according to this embodiment includes exchange or communication using only language, and exchange or communication involving contact or interaction. For example, a state in which a user touches a robot by holding the robot without speaking is also included in the state in which the user and the robot are communicating. Note that interaction with the user refers to actions in which the user and the robot touch each other (touching actions), such as stroking, tapping (touching), and hugging.

[0015] <Example of Overall Configuration of Robot 100> The configuration of the robot according to the embodiment will be described with reference to Figures 1 to 3. Figure 1 is a perspective view illustrating the robot 100 according to the embodiment. Figure 2 is a side view of the robot 100. Figure 3 is a cross-sectional view taken along line III-III in Figure 2.

[0016] As shown in FIGS. 1 to 3, the robot 100 is, for example, a doll-type robot modeled after a bear cub. The robot 100 can be driven by supplied power. The robot 100 is manufactured to have a size and weight suitable for being held by a user. However, the robot 100 is not limited to a doll-type robot modeled after a bear cub, and may have various shapes or structures.

[0017] The robot 100 has an exterior member 10 and a heat source disposed in a space surrounded by the exterior member 10. The thermal conductivity of the exterior member 10 is 0.3 W / mK or more, and the compressive stress when the exterior member 10 is compressed by 30% is 2.0 N / mm ２ The exterior member 10 may completely cover the heat source, or may have gaps or holes, or may have portions of different thicknesses. The exterior member 10 may be made of a uniform material, or may have portions made of different materials. When the exterior member 10 is made of multiple materials, the thermal conductivity of at least the portion of the exterior member 10 close to the heat source is 0.3 W / mK or more, and the compressive stress when the exterior member 10 is compressed 30% is 2.0 N / mm ２ The following is the result.

[0018] A heat source refers to any component included in the robot 100 that generates heat due to driving, power supply, etc. In the example shown in Figures 1 to 3, the camera 11, control unit 13, display 24, light 26, right arm servo motor 35a, left arm servo motor 35b, head servo motor 35c, right leg servo motor 35d, left leg servo motor 35e, etc. correspond to heat sources. The battery 15, which generates heat when power is supplied, also corresponds to a heat source.

[0019] The 30% compression refers to a state in which the exterior member 10 is compressed to a thickness that is 30% of the thickness of the original, uncompressed exterior member 10. The thickness of the original, uncompressed exterior member 10 can be, for example, 10 mm or more and 50 mm or less.

[0020] In the robot 100, the thermal conductivity of the exterior member 10 is 0.3 W / mK or more, so that heat generated from a heat source disposed in a space surrounded by the exterior member 10 can be dissipated to the outside of the exterior member 10 through the exterior member 10. In addition, the compressive stress when the exterior member 10 is compressed by 30% is 2.0 N / mm ２ or less, a user who touches the robot 100 can feel the softness of the exterior member 10. As a result, in this embodiment, it is possible to reduce the temperature rise in the space surrounded by the exterior member 10 and provide a robot 100 with a soft exterior. The compressive stress when the exterior member 10 is compressed 30% is preferably 1.5 N / mm ２The coefficient of thermal conductivity is preferably 1.0 or less. The exterior member 10 may be disposed at a distance from the heat source, but from the viewpoint of heat dissipation, it is preferable that the exterior member 10 be in contact with the heat source. A member having a different thermal conductivity from that of the exterior member 10 may be interposed between the heat source and the exterior member 10. From the viewpoint of heat dissipation, it is preferable that a member having a higher thermal conductivity than the exterior member 10 be interposed. It is more preferable that the member with a higher thermal conductivity is exposed on the surface of the exterior member 10, and it is even more preferable that the member with a higher thermal conductivity is in contact with the heat source. The member interposed between the heat source and the exterior member 10 may be a fluid. If the fluid is air, holes serving as flow paths may be formed on the surface of the exterior member 10. The exterior member 10 may be in contact with the heat source at any point, and the contact point may be a single point or multiple contact points. However, from the viewpoint of heat dissipation, it is preferable that the exterior member 10 have many contact points with the heat source. Furthermore, the exterior member 10 may be in surface contact with the heat source. From the viewpoint of heat dissipation, it is preferable that the contact area of ​​the contact surface with the heat source is large. The exterior of the exterior member 10 may be further covered with a covering material. The covering material may have a larger surface area than the exterior member 10, or may have a smaller surface area than the exterior member 10. The covering material may be made of the same material as the exterior member 10, and may be formed continuously, for example, to form a film with fewer pores than the exterior member 10. As the covering material, for example, a fabric material such as a raised fabric or a knitted material is preferred from the viewpoint of providing a pleasant feel.

[0021] Furthermore, if the exterior member 10 is heavy, the robot 100 will be difficult for the user to lift. As a result, communication between the user and the robot 100 cannot be promoted, and the robot 100 may not be able to provide comfort to the user. Therefore, it is preferable that the specific gravity of the exterior member 10 of the robot 100 is 1.5 or less. When the specific gravity of the exterior member 10 is 1.5 or less, the robot 100 becomes lighter, making it easier for the user to lift the robot 100. This promotes communication between the user and the robot 100 and can provide comfort to the user.

[0022] Furthermore, a robot with a soft exterior is prone to deformation when touched by a user. If it takes a long time for the robot 100 to return to its original state after being deformed by touch, the user may not be able to feel comforted by seeing the robot 100 in its deformed state. For example, a cute baby bear robot may provide comfort to a user, but a baby bear robot with a deformed face, etc., lacks cuteness compared to an undeformed robot, and therefore provides less comfort to the user. For this reason, the robot 100 has a compression recovery speed of 0.5 s, which is the speed at which the exterior material recovers to 67% of its original compression amount when unloaded after being compressed by 30%. －１ By satisfying this condition, even if the exterior is soft and easily deformed, the time it takes for the robot 100 to return to its original state after deformation can be shortened. As a result, the robot 100 can maintain its cuteness and provide a sense of comfort to the user.

[0023] The following describes in detail each part of the robot 100. The exterior member 10 will be described in detail separately with reference to FIGS.

[0024] The robot 100, for example, has a torso 1, a head 2, arms 3, and legs 4. The head 2 has a right eye 2a, a left eye 2b, a mouth 2c, a right cheek 2d, and a left cheek 2e. The arms 3 include a right arm 3a and a left arm 3b, and the legs 4 include a right leg 4a and a left leg 4b. Here, the torso 1 corresponds to the robot main body. The head 2, arms 3, and legs 4 each correspond to a driver connected to the robot main body so as to be displaceable relative to the robot main body.

[0025] The arms 3 are configured to be displaceable relative to the torso 1. For example, when the robot 100 is held by a user, the right arm 3 a and the left arm 3 b are displaced and come into contact with the neck, torso, etc. of the user as if embracing the user. This action makes the user feel a sense of closeness to the robot 100, thereby promoting interaction between the user and the robot 100. Note that interaction with the user refers to an action of touching the user and the robot 100, such as stroking, tapping (touching), hugging (embracing), etc.

[0026] The torso 1, head 2, arms 3, and legs 4 are all covered with an exterior member 10. The exterior member of the torso 1 and the exterior member of the arms 3 are integrated, and the exterior members of the head 2 and legs 4 are separate from the exterior members of the torso 1 and arms 3. However, this configuration is not limited to this, and for example, only the parts of the robot 100 that are likely to be touched by the user may be covered with the exterior member 10. Furthermore, at least one of the exterior members 10 of the torso 1, head 2, arms 3, and legs 4 may be separate from the other exterior members. Furthermore, the parts of the head 2, arms 3, and legs 4 that do not move may not include components such as sensors inside them and may be composed only of the exterior member 10.

[0027] In the robot 100, a camera 11, a tactile sensor 12, a control unit 13, a vital sensor 14, a battery 15, a first capacitance sensor 21, and a second capacitance sensor 31 are arranged in a space surrounded by the exterior member 10. Also, the camera 11, the tactile sensor 12, the control unit 13, the vital sensor 14, and the battery 15 are arranged in a space surrounded by the exterior member 10 in the torso 1. Furthermore, the first capacitance sensor 21 is arranged in a space surrounded by the exterior member 10 in the head 2, and the second capacitance sensor 31 is arranged in a space surrounded by the exterior member 10 in the arm 3.

[0028] Furthermore, in the robot 100, a display 24, a speaker 25, and a light 26 are arranged in the space surrounded by the exterior member 10 in the head 2. Furthermore, a display 24 is arranged in the space surrounded by the exterior member 10 in the right eye 2a and the left eye 2b. In addition, a speaker 25 is arranged in the space surrounded by the exterior member 10 in the mouth 2c, and a light 26 is arranged in the space surrounded by the exterior member 10 in the right cheek 2d and the left cheek 2e. The display 24 corresponds to the display unit arranged in the eye of the robot 100. The speaker 25 corresponds to the sound generation unit arranged in the mouth of the robot 100. The light 26 corresponds to the light-emitting unit arranged in the cheek of the robot 100.

[0029] 3, in the robot 100, a torso frame 16 and a torso mount 17 are disposed in the space enclosed by the exterior member 10 of the torso 1. A head frame 22 and a head mount 23 are disposed in the space enclosed by the exterior member 10 of the head 2. A right arm frame 32a and a right arm mount 33 are disposed in the space enclosed by the exterior member 10 of the right arm 3a, and a left arm frame 32b is disposed in the space enclosed by the exterior member 10 of the left arm 3b. In addition, a right leg frame 42a is disposed in the space enclosed by the exterior member 10 of the right leg 4a, and a left leg frame 42b is disposed in the space enclosed by the exterior member 10 of the left leg 4b.

[0030] The torso frame 16, head frame 22, right arm frame 32a, left arm frame 32b, right leg frame 42a, and left leg frame 42b are each structures formed by combining multiple columnar members. The torso support platform 17, head support platform 23, and right arm support platform 33 are plate-like members having support surfaces. The torso support platform 17 is fixed to the torso frame 16, the head support platform 23 is fixed to the head frame 22, and the right arm support platform 33 is fixed to the right arm frame 32a. Note that the torso frame 16, head frame 22, right arm frame 32a, left arm frame 32b, right leg frame 42a, and left leg frame 42b may be formed in a box shape including multiple plate-like members.

[0031] The right arm frame 32a is connected to the torso frame 16 via a right arm connecting mechanism 34a. The right arm frame 32a is driven by a right arm servomotor 35a and is therefore displaceable relative to the torso frame 16. Displacement of the right arm frame 32a causes the right arm 3a to displace relative to the torso 1. The right arm connecting mechanism 34a preferably has, for example, a reducer that increases the output torque of the right arm servomotor 35a.

[0032] In this embodiment, the right arm frame 32a is configured as an articulated robot arm including multiple frame members and multiple connecting mechanisms. For example, the right arm frame 32a has a right shoulder frame F1a, a right right arm frame F2a, a right elbow frame F3a, and a right forearm frame F4a. The torso frame 16, the right shoulder frame F1a, the right right arm frame F2a, the right elbow frame F3a, and the right forearm frame F4a are connected to each other via connecting mechanisms.

[0033] The right arm servo motor 35a is a collective term for multiple servo motors. For example, the right arm servo motor 35a includes a right shoulder servo motor M1a, a right right arm servo motor M2a, a right elbow servo motor M3a, and a right forearm servo motor M4a. The right shoulder servo motor M1a rotates the right shoulder frame F1a around a rotation axis perpendicular to the torso frame 16. The right right arm servo motor M2a rotates the right right arm frame F2a around a rotation axis perpendicular to the rotation axis of the right shoulder frame F1a. The right elbow servo motor M3a rotates the right elbow frame F3a around a rotation axis perpendicular to the rotation axis of the right right arm frame F2a. The right forearm servo motor M4a rotates the right forearm frame F4a around a rotation axis perpendicular to the rotation axis of the right elbow frame F3a.

[0034] The left arm frame 32b is connected to the torso frame 16 via a left arm connecting mechanism 34b. The left arm frame 32b is driven by a left arm servomotor 35b, and is thereby displaceable relative to the torso frame 16. Displacement of the left arm frame 32b causes the left arm 3b to displace relative to the torso 1. The left arm connecting mechanism 34b preferably has, for example, a reducer that increases the output torque of the left arm servomotor 35b.

[0035] The left arm frame 32b is configured as an articulated robot arm including multiple frame members and multiple connecting mechanisms. For example, the left arm frame 32b has a left shoulder frame F1b, a left upper arm frame F2b, a left elbow frame F3b, and a left forearm frame F4b. The torso frame 16, the left shoulder frame F1b, the left upper arm frame F2b, the left elbow frame F3b, and the left forearm frame F4b are connected to each other via connecting mechanisms.

[0036] The left arm servo motor 35b is a collective term for multiple servo motors. For example, the left arm servo motor 35b includes a left shoulder servo motor M1b, a left upper arm servo motor M2b, a left elbow servo motor M3b, and a left forearm servo motor M4b. The left shoulder servo motor M1b rotates the left shoulder frame F1b around a rotation axis perpendicular to the torso frame 16. The left upper arm servo motor M2b rotates the left upper arm frame F2b around a rotation axis perpendicular to the rotation axis of the left shoulder frame F1b. The left elbow servo motor M3b rotates the left elbow frame F3b around a rotation axis perpendicular to the rotation axis of the left upper arm frame F2b. The left forearm servo motor M4b rotates the left forearm frame F4b around a rotation axis perpendicular to the rotation axis of the left elbow frame F3b.

[0037] By providing the arms 3 with four joints in this way, the robot 100 can perform more realistic movements. For example, the robot 100 can perform an action that induces contact with a user by moving the arms 3 to "spread its hands" toward a user who is feeling neutral and not doing anything. The robot 100 can also perform an action that induces contact with a user by shaking the arms 3 to "be frightened" toward a user who is walking with angry feelings.

[0038] The head frame 22 is connected to the torso frame 16 via a head connection mechanism 27. The head frame 22 is driven by a head servomotor 35c and is displaceable relative to the torso frame 16. Displacement of the head frame 22 displaces the head 2 relative to the torso 1. The head connection mechanism 27 preferably has, for example, a reducer that increases the output torque of the head servomotor 35c.

[0039] The head frame 22 has a neck frame F1c and a face frame F2c. The torso frame 16, the neck frame F1c, and the face frame F2c are connected to each other via connecting mechanisms.

[0040] The head servomotor 35c is a general term for multiple servomotors. For example, the head servomotor 35c has a neck servomotor M1c and a face servomotor M2c. The neck servomotor M1c rotates the neck frame F1c around a rotation axis perpendicular to the body frame 16. The face servomotor M2c rotates the face frame F2c around a rotation axis perpendicular to the rotation axis of the neck frame F1c.

[0041] By providing the head 2 with two-axis joints in this way, the robot 100 can achieve more realistic movements. For example, if the robot 100 moves its head 2 to "look up at the face" (pay attention) to a user who is operating a mobile phone with disgust, the robot 100 can express concern for the user and induce contact with the user.

[0042] The right leg frame 42a is connected to the torso frame 16 via a right leg connecting mechanism 44a. The right leg frame 42a has a right leg wheel 41a on its bottom side. To stabilize the posture of the robot 100, the robot 100 preferably has two right leg wheels 41a in the front-to-rear direction of the right leg frame 42a. The right leg wheel 41a is driven by the right leg servo motor 35d and is rotatable around a rotation axis perpendicular to the front-to-rear direction of the right leg frame 42a. The rotation of the right leg wheel 41a enables the robot 100 to run. The right leg connecting mechanism 44a preferably has a reducer that increases the output torque of the right leg servo motor 35d, for example.

[0043] The left leg frame 42b is connected to the torso frame 16 via a left leg connecting mechanism 44b. The left leg frame 42b has a left leg wheel 41b on its bottom side. To stabilize the posture of the robot 100, the robot 100 preferably has two left leg wheels 41b in the front-to-rear direction of the left leg frame 42b. The left leg wheel 41b is driven by the left leg servo motor 35e and is rotatable around a rotation axis perpendicular to the front-to-rear direction of the left leg frame 42b. The rotation of the left leg wheel 41b enables the robot 100 to run. The left leg connecting mechanism 44b preferably has, for example, a reducer that increases the output torque of the left leg servo motor 35e.

[0044] In this embodiment, the robot 100 moves forward or backward by simultaneously rotating the right leg wheel 41 a and the left leg wheel 41 b forward or backward. The robot 100 turns right or left by braking either the right leg wheel 41 a or the left leg wheel 41 b and rotating the other forward or backward.

[0045] In this way, the legs 4 allow the robot 100 to perform more realistic movements. For example, the robot 100 can move the legs 4 to "approach" a user who is standing still and feeling sad or surprised, thereby enabling the robot 100 to perform an action that induces contact with the user.

[0046] The camera 11 is fixed to the torso frame 16. The tactile sensor 12, the control unit 13, the vital sensor 14, and the battery 15 are fixed to the torso mounting base 17. The control unit 13 and the battery 15 are fixed to the torso mounting base 17 on the side opposite to the side on which the tactile sensor 12 and the vital sensor 14 are fixed. Note that the placement of the control unit 13 and the battery 15 here is based on the available space on the torso mounting base 17 and is not necessarily limited to the above. However, if the battery 15 is fixed to the side opposite to the side on the torso mounting base 17 on which the tactile sensor 12 and the vital sensor 14 are fixed, the center of gravity of the robot 100 will be lower because the battery 15 is heavier than the other components. A lower center of gravity of the robot 100 is preferable because it stabilizes at least one of the position and posture of the robot 100 and makes it easier to charge and replace the battery 15.

[0047] The first capacitance sensor 21 is fixed to the head rest 23, and the second capacitance sensor 31 is fixed to the right arm rest 33. The display 24 has a right eye display 24a and a left eye display 24b. The right eye display 24a, the left eye display 24b, and the speaker 25 are fixed to the head frame 22. The light 26 has a right cheek light 26a and a left cheek light 26b. The right cheek light 26a and the left cheek light 26b are fixed to the head frame 22.

[0048] The camera 11, tactile sensor 12, control unit 13, vital sensor 14, battery 15, first capacitance sensor 21, second capacitance sensor 31, etc. can be fixed with screws, adhesive members, etc. The right eye display 24a, left eye display 24b, speaker 25, right cheek light 26a, left cheek light 26b, etc. can also be fixed with screws, adhesive members, etc.

[0049] There are no particular limitations on the materials used for the torso frame 16, torso support base 17, head frame 22, head support base 23, right arm frame 32a, right arm support base 33, and left arm frame 32b, and resin or metal materials can be used. However, from the perspective of ensuring strength during operation, it is preferable to use a metal material such as aluminum for the torso frame 16, right arm frame 32a, and left arm frame 32b. On the other hand, if strength can be ensured, it is preferable to use a resin material for these components in order to reduce the weight of the robot 100. There are no particular limitations on the materials used for the torso support base 17, head frame 22, head support base 23, right arm support base 33, and left arm frame 32b, and resin or metal materials can be used, but from the perspective of reducing the weight of the robot 100, it is preferable to use a resin material.

[0050] The control unit 13 is communicatively connected to the camera 11, tactile sensor 12, vital sign sensor 14, first capacitance sensor 21, second capacitance sensor 31, right arm servo motor 35a, and left arm servo motor 35b via wired or wireless communication. The control unit 13 is also communicatively connected to the head servo motor 35c, right leg servo motor 35d, and left leg servo motor 35e via wired or wireless communication. The control unit 13 is also communicatively connected to the right eye display 24a, left eye display 24b, speaker 25, right cheek light 26a, and left cheek light 26b via wired or wireless communication.

[0051] The camera 11 is an image sensor that outputs a captured image of the periphery of the robot 100 to the control unit 13. In this embodiment, the camera 11 captures an image of the user. The camera 11 includes a lens and an imaging element that captures an image through the lens. The imaging element may be a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The captured image may be either a still image or a video image.

[0052] The camera 11 is preferably configured as a TOF (Time Of Flight) camera that outputs a distance image of the periphery of the robot 100 to the control unit 13. Therefore, the captured image output from the camera 11 may include a three-dimensional captured image (distance image) in addition to or instead of a two-dimensional captured image. The captured image is used to detect the presence or approach of a user, detect the distance from the robot 100 to the user, authenticate the user, or estimate the user's emotions or behavior. The captured image corresponds to a captured image of the user. In addition to the camera 11, the robot 100 may also be equipped with an ultrasonic sensor, an infrared sensor, a millimeter-wave radar, a LiDAR (Light Detection and Ranging), or the like.

[0053] Furthermore, the camera 11 acquires a captured image of the user as distance information to the user, and outputs the image to the control unit 13. For example, the control unit 13 acquires in advance a correspondence relationship between the image size of an object included in the captured image and the distance to the object, and can obtain the distance to the user by referring to the correspondence relationship based on the size of the image of the user included in the captured image.

[0054] The tactile sensor 12 is a sensor element that detects information sensed by the sense of touch of a human hand, converts it into a tactile signal, which is an electrical signal, and outputs it to the control unit 13. The tactile sensor 12 corresponds to a contact detection unit that detects contact with a user. For example, the tactile sensor 12 converts information on pressure and vibrations generated when the user touches the robot 100 into a tactile signal using a piezoelectric element and outputs it to the control unit 13. The tactile signal output from the tactile sensor 12 corresponds to contact information detected by the contact detection unit. The tactile signal is used to detect contact or presence of the user 200 with the robot 100.

[0055] The vital sensor 14 can acquire biometric information of a movable object. The vital sensor 14 is an electromagnetic wave sensor that acquires biometric information of a user using electromagnetic waves. The vital sensor 14 will be described in detail later with reference to FIG. 4 .

[0056] The first capacitance sensor 21 and the second capacitance sensor 31 are sensor elements that detect, based on a change in capacitance, that a user has come into contact with or proximity to the robot 100 and output a capacitance signal to the control unit 13. The first capacitance sensor 21 is preferably a rigid sensor that does not have flexibility in terms of stabilizing the exterior member 10. Because the arm portion 3 is a part that is likely to be touched by a user, the second capacitance sensor 31 is preferably a flexible sensor that includes conductive thread or the like in terms of improving the feel to the touch. The capacitance signals output from the first capacitance sensor 21 and the second capacitance sensor 31 are used to detect the proximity or presence of a user to the robot 100.

[0057] The right-eye display 24a and the left-eye display 24b are display modules that display character strings or images such as letters, numbers, and symbols in response to commands from the control unit 13. The right-eye display 24a and the left-eye display 24b are configured, for example, by liquid crystal display modules. The character strings or images displayed on the right-eye display 24a and the left-eye display 24b are used to express the emotions of the robot 100. For example, if a user is sitting with happy emotions, the robot 100 can display a "smiling" image on the right-eye display 24a and the left-eye display 24b to empathize with the user's happiness, thereby implicitly inducing interaction with the user.

[0058] The speaker 25 is a speaker unit that amplifies an audio signal from the control unit 13 and outputs the audio. The audio output from the speaker 25 is the words or cries of the robot 100 and is used to express the emotions of the robot 100. For example, the robot 100 can perform an action that induces interaction with the user by outputting a voice of "making a (worried) voice" from the speaker 25 to a user who is doing housework and feeling sad.

[0059] The right cheek light 26a and the left cheek light 26b are light modules that blink or change color in response to an on / off signal from the control unit 13. The right cheek light 26a and the left cheek light 26b are configured, for example, by LED (Light Emitting Diode) light modules. The blinking or color change of the right cheek light 26a and the left cheek light 26b is used to express emotions of the robot 100. For example, if a user is sitting and feeling sad, the robot 100 can express empathy by making the right cheek light 26a and the left cheek light 26b blink blue, thereby enabling the robot 100 to perform an action that induces interaction with the user.

[0060] The battery 15 can supply power to the camera 11, tactile sensor 12, control unit 13, vital sign sensor 14, first capacitance sensor 21, second capacitance sensor 31, right arm servo motor 35a, and left arm servo motor 35b. The battery 15 can also supply power to the head servo motor 35c, right leg servo motor 35d, and left leg servo motor 35e. The battery 15 can also supply power to the right eye display 24a, left eye display 24b, speaker 25, right cheek light 26a, and left cheek light 26b. Various secondary batteries such as lithium ion batteries and lithium polymer batteries can be used as the battery 15.

[0061] Note that the various sensors such as the first capacitance sensor 21 and the second capacitance sensor 31 in the robot 100 are not essential components. The robot 100 is only required to have at least the camera 11, the vital sensor 14, and the tactile sensor 12. The installation positions of these sensors can also be changed as appropriate. Furthermore, the various sensors such as the camera 11, the vital sensor 14, and the tactile sensor 12 may be arranged outside the robot 100 and transmit necessary information to the robot 100 or an external device via wireless communication.

[0062] Furthermore, the robot 100 does not necessarily have to have the control unit 13 inside the exterior member 10, and the control unit 13 can also communicate with each device wirelessly from outside the exterior member 10. The battery 15 can also supply power to each component from outside the exterior member 10.

[0063] Although the head 2, arms 3, and legs 4 are configured to be movable, the present invention is not limited to this configuration, and at least one of the head 2, arms 3, and legs 4 may be movable. The arms 3 are configured as four-axis articulated robot arms, but may also be configured as six-axis articulated robot arms. It is preferable that an end effector such as a hand can be connected to the arms 3. The legs 4 are configured as wheels, but may also be configured as crawlers, legs, or the like.

[0064] The configuration and shape of the robot 100 are not limited to those illustrated in Figures 1 to 3, and can be changed as appropriate depending on the user's preferences and the manner in which the robot 100 is used. For example, the robot 100 may be in the form of a robot arm such as an industrial robot, or in the form of a humanoid robot, instead of a form resembling a bear cub. The robot 100 may also be in the form of a mobile device such as a drone or vehicle that has at least one of an arm, a display, a speaker, a light, and the like.

[0065] 4 is a diagram illustrating an example of the configuration of the vital sensor 14. The vital sensor 14 includes a microwave emitter 141 and a microwave receiver 142. Microwaves correspond to an example of electromagnetic waves.

[0066] The vital sensor 14 emits a microwave emitted wave Ms from the inside of the exterior member 10 of the robot 100 toward the user 200 using the microwave emitter 141. The vital sensor 14 also receives a reflected wave Mr, which is the emitted wave Ms reflected by the user 200, using the microwave receiver 142.

[0067] The vital sensor 14 uses the Doppler effect from the difference between the frequency of the emitted wave Ms and the frequency of the reflected wave Mr to detect, in a non-contact manner, minute displacements occurring on the body surface due to, for example, the beating of the heart of the user 200. The vital sensor 14 can obtain information such as the heart rate, breathing, pulse wave, and blood pressure as biometric information of the user 200 from the detected minute displacements, and output the obtained biometric information to the control unit 13.

[0068] However, the vital sensor 14 is not limited to a microwave Doppler sensor, and may be one that detects minute displacements occurring on the body surface by utilizing changes in the coupling between the human body and an antenna, or one that uses electromagnetic waves other than microwaves, such as near-infrared light. The vital sensor 14 may also be a millimeter-wave radar, microwave radar, or the like. Furthermore, it is preferable that the vital sensor 14 also includes, in addition to a Doppler sensor, a non-contact thermometer that detects infrared rays or the like emitted from the user 200. In this case, the vital sensor 14 detects biological information of the user 200, including information regarding at least one of heart rate (pulse), respiration, blood pressure, and body temperature.

[0069] In the robot 100, the vital sensor 14 is provided inside the exterior member 10, so the user 200 cannot see the vital sensor 14. This reduces the user 200's resistance to having their biometric information detected, making it possible to smoothly acquire the biometric information. Furthermore, because the vital sensor 14 can acquire biometric information without contact, it can acquire biometric information even if the user moves to a certain extent, unlike contact-type sensors that require the user to touch the same place for a certain period of time.

[0070] Furthermore, by promoting contact between the user 200 and the robot 100 through a hugging motion or the like of the robot 100, the vital sensor 14 can acquire biometric information while the robot 100 is being hugged by the user 200 and is in contact with or close to the user 200. The vital sensor 14 can acquire highly reliable biometric information with reduced noise.

[0071] <Configuration Example of Control Unit 13> (Hardware Configuration Example) Fig. 5 is a block diagram showing the hardware configuration of the control unit 13. The control unit 13 is constructed by a computer and has a CPU (Central Processing Unit) 131, a ROM (Read Only Memory) 132, and a RAM (Random Access Memory) 133. The control unit 13 also has an HDD / SSD (Hard Disk Drive / Solid State Drive) 134, a device connection I / F (Interface) 135, and a communication I / F 136. These are connected to each other via a system bus A so as to be able to communicate with each other.

[0072] The CPU 131 executes control processing including various types of arithmetic processing. The ROM 132 stores programs used to drive the CPU 131, such as an IPL (Initial Program Loader). The RAM 133 is used as a work area for the CPU 131. The HDD / SSD 134 stores various types of information such as programs, captured images acquired by the camera 11, biological information acquired by the vital sensor 14, and detection information from various sensors such as tactile signals acquired by the tactile sensor 12.

[0073] The device connection I / F 135 is an interface for connecting the control unit 13 to various external devices. The external devices here include the camera 11, the tactile sensor 12, the vital sign sensor 14, the first capacitance sensor 21, the second capacitance sensor 31, the servo motor 35, and the battery 15. The external devices also include the display 24, the speaker 25, the light 26, and the like.

[0074] Here, the servo motor 35 is a collective term for the right arm servo motor 35a, the left arm servo motor 35b, the head servo motor 35c, the right leg servo motor 35d, and the left leg servo motor 35e. The display 24 is a collective term for the right eye display 24a and the left eye display 24b. The light 26 is a collective term for the right cheek light 26a and the left cheek light 26b.

[0075] The communication I / F 136 is an interface for communicating with an external device via a communication network, etc. For example, the control unit 13 connects to the Internet via the communication I / F 136 and communicates with an external device via the Internet.

[0076] At least a part of the functions realized by the CPU 131 may be realized by an electric circuit or an electronic circuit.

[0077] 6 is a block diagram showing the functional configuration of the control unit 13. The control unit 13 has an acquisition unit 101, a communication control unit 102, a storage unit 103, an authentication unit 104, a registration unit 105, a start control unit 106, a motor control unit 107, an output unit 108, and a detection unit 109.

[0078] The functions of the acquisition unit 101 and the output unit 108 are realized by the device connection I / F 135 or the like, and the function of the communication control unit 102 is realized by the communication I / F 136 or the like. Furthermore, the functions of the storage unit 103 and the registration unit 105 are realized by a non-volatile memory such as the HDD / SSD 134. Furthermore, the functions of the authentication unit 104, the start control unit 106, the motor control unit 107, and the detection unit 109 are realized by a processor such as the CPU 131 executing processing defined in a program stored in a non-volatile memory such as the ROM 132. Note that some of the above functions may be realized by an external device such as a PC or a server, or may be realized by distributed processing between the control unit 13 and the external device.

[0079] The acquisition unit 101 controls communication between the control unit 13 and the camera 11, thereby acquiring a captured image Im of the user 200 from the camera 11. The acquisition unit 101 also controls communication between the control unit 13 and the tactile sensor 12, thereby acquiring a tactile signal S from the tactile sensor 12. The acquisition unit 101 also controls communication between the control unit 13 and the vital sensor 14, thereby acquiring biometric information B of the user 200 from the vital sensor 14.

[0080] The acquisition unit 101 also controls communication between the control unit 13 and the first capacitance sensor 21, thereby acquiring a first capacitance signal C1 from the first capacitance sensor 21. The acquisition unit 101 also controls communication between the control unit 13 and the second capacitance sensor 31, thereby acquiring a second capacitance signal C2 from the second capacitance sensor 31.

[0081] The communication control unit 102 can control communication with an external device via a communication network, etc. For example, the communication control unit 102 can transmit the captured image Im acquired by the camera 11, the biological information B acquired by the vital sensor 14, the tactile signal S acquired by the tactile sensor 12, etc. to the external device via the communication network.

[0082] The storage unit 103 can store the biometric information B acquired by the vital sensor 14. While the acquisition unit 101 is acquiring the biometric information B from the vital sensor 14, the storage unit 103 continuously stores the acquired biometric information B. The storage unit 103 can also store information obtained from the image Im captured by the camera 11, the tactile signal S from the tactile sensor 12, the first capacitance signal C1 from the first capacitance sensor 21, and the second capacitance signal C2 from the second capacitance sensor 31.

[0083] The authentication unit 104 can perform personal authentication of the user 200 based on the image Im of the user 200 captured by the camera 11. For example, the authentication unit 104 performs face authentication by referring to registration information 150 of facial images pre-registered in the registration unit 105 based on the captured image Im including the face of the user 200 captured by the camera 11. This allows the user 200 currently in contact with or in close proximity to the robot 100 to be associated with pre-registered personal information, and the biometric information B acquired by the vital sensor 14 to be associated with the personal information. Furthermore, if the facial image included in the captured image Im is not registered in the registration unit 105, the control unit 13 can control the vital sensor 14 to stop starting acquisition of biometric information.

[0084] The start control unit 106 causes the vital sensor 14 to start acquiring the biometric information B. For example, when the detection unit 109 detects that the user 200 is in contact with or approaching the robot 100, the start control unit 106 turns on a switch or the like that supplies power from the battery 15 to the vital sensor 14. This causes the start control unit 106 to start acquiring the biometric information B.

[0085] The detection unit 109 can detect the presence or approach of the user 200 around the robot 100 based on the image Im captured by the camera 11, etc. The detection unit 109 preferably detects the distance from the robot 100 to the user 200 based on the image Im (distance image) captured by the camera 11. The detection unit 109 may also detect the proximity or presence of the user 200 to the robot 100 based on the first capacitance signal C1 or the second capacitance signal C2. Furthermore, the detection unit 109 detects the contact or presence of the user 200 with the robot 100 based on the tactile signal S from the tactile sensor 12.

[0086] The motor control unit 107 controls the driving of the servo motor 35 .

[0087] The output unit 108 controls communication between the control unit 13 and the battery 15 in response to a command from the start control unit 106. The output unit 108 also controls communication between the control unit 13 and the servo motor 35 in response to a command from the motor control unit 107.

[0088] <Configuration example of exterior member 10> In the robot 100, the exterior member 10 is configured to include a composite material 300. Figures 7 and 8 are schematic cross-sectional views of the composite material 300 according to an embodiment. Figure 7 shows an example of the composite material 300, and Figure 8 shows another example of the composite material 300. Figures 7 and 8 show a cross section of the composite material 300 when the exterior member 10 configured to include the composite material 300 is cut along a plane approximately parallel to the thickness direction of the exterior member 10.

[0089] 7 , the exterior member 10 has a skeleton 30 containing a first resin, a plurality of voids 40, and a plurality of inorganic particles 301. The composite material 300 has heat transfer paths 325 and 326. The plurality of inorganic particles 301 form the heat transfer paths 325 and 326 that extend along the peripheries of the plurality of voids 40.

[0090] Since the heat transfer paths 325 and 326 are formed in the composite material 300 along the peripheries of the plurality of voids 40, heat in the space surrounded by the exterior member 10 is easily transferred through the composite material 300. As a result, the exterior member 10 achieves a thermal conductivity of 0.3 W / (m·K) or more, and the heat dissipation properties of the exterior member 10 can be improved. Furthermore, the skeleton 30 of the composite material 300 includes a first resin, and the composite material 300 includes a plurality of voids 40. As a result, the composite material 300 can be made softer compared to when the skeleton 30 does not include the first resin or when the composite material 300 does not include a plurality of voids 40. Since the exterior member 10 is configured to include the composite material 300, it is flexible and easily deformed, and therefore has a compressive stress of 2.0 N / mm when compressed 30%. ２ The following can be achieved: Furthermore, since the voids 40 contained in the composite material 300 have excellent restoring properties to return to their original state, even if the composite material 300 is deformed, it can quickly return to approximately its original state.

[0091] As shown in FIG. 7 , the composite material 300 includes, for example, a first layer 323 and a second layer 324. The first layer 323 and the second layer 324 are arranged along the periphery of each of the plurality of voids 40. The first layer 323 includes a plurality of inorganic particles 301. The second layer 324 covers the first layer 323 from the side opposite the skeleton 30 and faces the voids 40. The second layer 324 includes at least one resin selected from the group consisting of a first resin and a second resin different from the first resin. The second layer 324 may also include the second resin. According to the embodiment shown in FIG. 7 , the first layer 323 including the plurality of inorganic particles 301 is covered by the second layer 324, so the inorganic particles 301 are less likely to peel off from the composite material 300. As a result, the thermal conductivity of the composite material 300 is less likely to deteriorate.

[0092] Peeling of the inorganic particles 301 from the composite material 300 can be confirmed, for example, by the following method. After shaking the composite material 300 using a device such as a shaker, it is visually confirmed that the inorganic particles 301 have been peeled off from the composite material 300. Alternatively, peeling of the inorganic particles 301 from the composite material 300 can also be confirmed by shaking the composite material 300 and then performing elemental analysis on the solid matter that has peeled off from the composite material 300. For elemental analysis, methods such as inductively coupled plasma (ICP), optical emission spectroscopy, energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (ESCA) are used.

[0093] Peeling of the inorganic particles 301 from the composite material 300 can also be confirmed, for example, by examining whether or not the inorganic particles 301 have eluted from the composite material 300. Furthermore, elution of the inorganic particles 301 from the composite material 300 can be confirmed, for example, by the following method. The composite material 300 is immersed in a solvent such as toluene, and then the composite material 300 is removed from the solvent, and the cloudiness of the solvent is visually confirmed. Alternatively, the solvent in which the composite material 300 has been immersed is volatilized, and the remaining solid content is subjected to elemental analysis, thereby confirming whether or not the inorganic particles 301 have eluted from the composite material 300. For elemental analysis, a method such as ICP, EDX, or ESCA is used, for example.

[0094] As shown in FIG. 7 , the composite material 300 has, for example, a porous structure having a plurality of voids 40. As described above, the composite material 300 has heat conduction paths 325 and 326. The heat conduction paths 325 and 326 extend, for example, within the first layer 323. The heat conduction paths 325 and 326 extend, for example, across the plurality of voids 40. The heat conduction paths 325 and 326 are formed by a plurality of inorganic particles 301 that are continuously arranged, in other words, arranged so as to be in contact with or close to each other. The heat conduction paths 325 and 326 extend, for example, along the end of the skeleton 30 without passing through the interior of the skeleton 30. For example, some of the heat conduction paths 325 reach from the surface 300 a of the composite material 300 to the surface 300 b opposite to the surface 300 a.

[0095] In the composite material 300, at least some of the plurality of voids 40 may be arranged so as to be in contact with one another. In the composite material 300, at least some of the plurality of voids 40 may be arranged so that the first layers 323 are connected to one another. For example, as shown in Fig. 7 , in the composite material 300, at least some of the plurality of voids 40 are arranged so that the first layers 323 on the periphery of each void 40 are connected at the connection portion 311, but the second layers 324 are not connected.

[0096] It should be noted that not all heat transfer paths are necessarily visible in a particular cross section such as that shown in Figure 7, and further, not all portions of a particular heat transfer path are necessarily visible. For example, heat transfer path 326 does not appear to extend to surface 300b in Figure 7. However, heat transfer path 326 reaches surface 300b through inorganic particles that are not visible in this cross section. Similarly, it is not possible to confirm the contact of all voids in a particular cross section. For example, void 50 appears isolated in Figure 7. However, void 50 is in contact with another void adjacent in the thickness direction of the paper.

[0097] However, it is not necessary for all heat transfer paths to reach from surface 300a to surface 300b, and it is not necessary for all voids contained in the porous structure to be in contact with other voids directly or via inorganic particles.

[0098] For example, no inorganic particles 301 are present in the connection portion 311. For example, a first layer 323 and a second layer 324 are formed in the connection portion 311. Therefore, the voids 40 that are in direct contact with each other in the connection portion 311 are not connected to each other.

[0099] For example, inorganic particles 302 are present in the connection portion 313. A first layer 323 and a second layer 324 are also present in the connection portion 313. However, the voids 40 that appear to be adjacent to each other across the connection portions 311 and 313 in Fig. 7 may be in direct contact and communicate with each other in a cross section other than that shown in Fig. 7.

[0100] For example, the connection portion 315 includes a portion where the inorganic particles 301, the first layer 323, and the second layer 324 are not present. The voids 40 that are in contact with each other in the connection portion 315 form a single space that is in communication with each other via the connection portion 315.

[0101] As shown in FIG. 8 , particles 60 may be present inside the voids 40. The particles 60 are typically resin particles. The particles 60 may be resin particles that have shrunk due to heat treatment. The resin particles before shrinkage may have a shape corresponding to the voids 40. The resin that occupied the voids may be removed as shown in FIG. 7 or may remain deformed as shown in FIG. 8 . In the latter case, the particles 60 may be in contact with the second layer 324. Even inside the voids 50 where the presence of particles 60 cannot be confirmed in a specific cross section, the presence of particles 60 may be confirmed by observing another cross section. In the embodiment shown in FIG. 8 , particles 60 smaller than the voids 40 and at least a portion of the voids 50 are present.

[0102] The inorganic particles 301 are not limited to a specific material. The inorganic particles 301 have, for example, a thermal conductivity higher than that of the skeleton 30. Examples of materials for the inorganic particles 301 include hexagonal boron nitride (h-BN), alumina, crystalline silica, amorphous silica, aluminum nitride, magnesium oxide, carbon fiber, silver, copper, aluminum, silicon carbide, graphite, zinc oxide, silicon nitride, silicon carbide, cubic boron nitride (c-BN), beryllia, diamond, carbon black, graphene, carbon nanotubes, carbon fiber, and aluminum hydroxide. The composite material 300 may contain only one type of inorganic particle 301, or two or more types of inorganic particles 301 may be combined and used in the composite material 300. The shape of the inorganic particles 301 is not limited to a specific shape. Examples of shapes include spherical, rod-shaped (including short fiber-shaped), scale-shaped, needle-shaped, and granular. The term "granular" refers to, for example, a shape in which a plurality of inorganic particles 301 are aggregated using a binder, or a sintered body of a plurality of inorganic particles 301.

[0103] The aspect ratio of the inorganic particles 301 is not limited to a specific value. The aspect ratio of the inorganic particles 301 may be less than 50, 40 or less, or even 30 or less. The aspect ratio of the inorganic particles 301 may be 1 or a value greater than 1, for example, 2 or more, or even 3 or more. Unless otherwise specified, the aspect ratio is determined by the ratio of the maximum diameter of the particle to the minimum diameter of the particle (maximum diameter / minimum diameter). In this specification, the minimum diameter is determined by the shortest line segment passing through the midpoint of the line segment defining the maximum diameter.

[0104] The average particle size of the inorganic particles 301 is not limited to a specific value. The average particle size of the inorganic particles 301 is, for example, 0.05 μm to 100 μm, and may be 0.1 μm to 50 μm, 0.1 μm to 30 μm, or 0.5 to 10 μm. The "average particle size" can be determined, for example, by a laser diffraction scattering method. The average particle size is the 50% cumulative value (median diameter) d50, which is determined from a particle size distribution curve in which frequency is expressed as a volume-based fraction using, for example, a particle size distribution meter (Microtrac MT3300EXII) manufactured by Microtrac-Bell.

[0105] The shape of inorganic particle 301 can be determined by observation using, for example, a scanning electron microscope (SEM) etc. For example, when the aspect ratio (maximum diameter / minimum diameter) is 1.0 or more and less than 1.7, particularly 1.0 or more and 1.5 or less, further 1.0 or more and 1.3 or less, and at least a part, particularly substantially the entirety, of the outline is observed as a curve, inorganic particle 301 can be determined to be spherical.

[0106] The scale-like inorganic particles 301 have a plate-like shape having a pair of main surfaces and a side surface. The main surface is the surface with the largest area of ​​the inorganic particle 301 and is usually a substantially flat surface. When the inorganic particle 301 is scale-like, the aspect ratio is defined as the ratio of the average dimension of the main surface to the average thickness, instead of the above definition. The thickness of the scale-like inorganic particles 301 refers to the distance between the pair of main surfaces. The average thickness can be determined by measuring the thickness of any 50 inorganic particles 301 using an SEM and calculating the average value. The average dimension of the main surface can be the d50 value measured using the particle size distribution analyzer described above. The aspect ratio of the scale-like inorganic particles 301 may be 1.5 or more, 1.7 or more, or even 5 or more. The rod-like inorganic particles 301 have a rod-like shape such as a rod, column, tree, needle, or cone. The aspect ratio of the rod-like inorganic particles 301 may be 1.5 or more, 1.7 or more, or even 5 or more. Regardless of the shape of the inorganic particles 301, examples of the upper limit of the aspect ratio are as described above.

[0107] When the inorganic particles 301 are spherical, the average particle size is, for example, 0.1 μm or more and 50.0 μm or less, preferably 0.1 μm or more and 10.0 μm or less, and more preferably 0.5.0 μm or more and 5.0 μm or less. When the inorganic particles 301 are scaly, the average dimension of the main surfaces of the inorganic particles 301 is, for example, 0.1 μm or more and 20.0 μm or less, and preferably 0.5 μm or more and 15.0 μm or less. The average thickness of the inorganic particles 301 is, for example, 0.05 μm or more and 1.0 μm or less, and preferably 0.08 μm or more and 0.5 μm or less. When the inorganic particles 301 are rod-shaped, the minimum diameter (usually the minor axis length) of the inorganic particles 301 is, for example, 0.01 μm or more and 10 μm or less, and preferably 0.05 μm or more and 1.0 μm or less. Furthermore, the maximum diameter (usually the length of the major axis) of the inorganic particles 301 is, for example, 0.1 μm or more and 20.0 μm or less, and preferably 0.5 μm or more and 10.0 μm or less. If the size of the inorganic particles 301 is within this range, the inorganic particles 301 are likely to be arranged along the voids 40, and therefore the heat transfer paths 325 extending across the multiple voids 40 can be reliably formed. When the inorganic particles 301 are granular, the average particle size is, for example, 10.0 μm or more and 100.0 μm or less, and preferably 20.0 μm or more and 60.0 μm or less.

[0108] The content of the inorganic particles 301 in the composite material 300 is not limited to a specific value. The content of the inorganic particles 301 in the composite material 300 is, for example, 10% to 80% by mass, preferably 10% to 70% by mass, and more preferably 10% to 55% by mass. The content of the inorganic particles 301 in the composite material 300 is, for example, 1% to 50% by volume, preferably 2% to 45% by volume, more preferably 5% to 40% by volume, and particularly preferably 5% to 30% by volume. By appropriately adjusting the content of the inorganic particles 301, the composite material 300 can exhibit higher thermal conductivity and have appropriate rigidity.

[0109] The content [mass %] of inorganic particles 301 in composite material 300 can be determined by removing materials other than inorganic particles 301 from composite material 300 by burning or the like. To achieve a highly accurate measurement, the content [mass %] of inorganic particles may be calculated using elemental analysis. Specifically, acid is added to composite material 300, microwaves are irradiated, and the composite material 300 is subjected to pressure acid decomposition. Examples of acids that can be used include hydrofluoric acid, concentrated sulfuric acid, concentrated hydrochloric acid, and aqua regia. The solution obtained by pressure acid decomposition is subjected to elemental analysis using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Based on the results, the content [mass %] of inorganic particles 301 can be determined.

[0110] The content [vol %] of inorganic particles 301 in composite material 300 can be calculated from the mass and density of inorganic particles 301 contained in composite material 300 and the volume and porosity of composite material 300. Specifically, the volume A of inorganic particles 301 in composite material 300 is calculated from the mass and density of inorganic particles 301. Separately from this, the volume B of composite material 300 excluding the volume of voids 40 is calculated based on the porosity of composite material 300. The content [vol %] of inorganic particles 301 can be calculated by (A / B) × 100. A method for calculating porosity will be described later.

[0111] The density of the inorganic particles 301 can be determined by heating the composite material 300 at high temperature in an electric furnace to burn off the organic material, and measuring the remaining inorganic particles 301 in accordance with Japanese Industrial Standards (JIS) R 1628:1997 or JIS Z 2504:2012.

[0112] At least a portion of the inorganic particles 301 is present in the portion of the first layer 323 between the skeleton 30 and the second layer 324. Inorganic particles 302 and 303, which are other portions of the inorganic particles 301, may be present in the connection portions 313 of the voids 40 in the first layer 323. In these portions, inorganic particles 304, which are part of the inorganic particles 301, may be stacked with other inorganic particles in the thickness direction of the first layer 323. At least a portion of the inorganic particles 301 are in contact with or very close to adjacent inorganic particles, and constitute part of the heat transfer paths 325 and 326, respectively. However, inorganic particles 305, which are another portion of the inorganic particles 301, may be present surrounded by the skeleton 30. In other words, the skeleton 30 may contain inorganic particles 305 therein that are not in contact with the voids 40.

[0113] Substantially all of the inorganic particles 301 may be present in the first layer 323. In this specification, "substantially all" means 90% by mass or more, further 93% by mass or more, and particularly 95% by mass or more. This configuration increases the proportion of inorganic particles that contribute to improving thermal conductivity. The distribution of the inorganic particles 301 inside the skeleton 30 can be measured using, for example, three-dimensional X-ray microscopy (X-ray CT).

[0114] The first resin contained in the skeleton 30 is, for example, a cross-linked polymer. The first resin may be a thermosetting resin. Examples of thermosetting resins include phenolic resin, urea resin, melamine resin, diallyl phthalate resin, polyester resin, epoxy resin, aniline resin, silicone resin, furan resin, polyurethane resin, alkylbenzene resin, guanamine resin, xylene resin, and imide resin. The curing temperature of the resin is, for example, 25°C or higher and 160°C or lower.

[0115] The first resin may be a thermoplastic resin, examples of which include (meth)acrylic resin, styrene resin, polyethylene terephthalate resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, acrylonitrile-butadiene-styrene resin, and acrylonitrile-styrene resin.

[0116] The skeleton 30, for example, does not contain inorganic particles 301, or contains inorganic particles 301 at a content lower than that of the first layer 323. With this configuration, the content of inorganic particles 301 in the composite material 300 can be reduced. As a result, a composite material 300 that can have excellent thermal conductivity while reducing the amount of inorganic particles 301 used can be obtained. The content of inorganic particles 301 contained in the skeleton 30 and the first layer 323 can be compared using a method described below, such as scanning electron microscope / energy dispersive X-ray spectroscopy (SEM-EDX). Specifically, in the skeleton 30, the ratio X of the proportion of atoms derived from the inorganic particles 301 to the proportion of atoms derived from the resin is calculated. Similarly, in the first layer 323, the ratio Y of the proportion of atoms derived from the inorganic particles 301 to the proportion of atoms derived from the resin is calculated. If the relationship between X and Y satisfies X<Y, it can be determined that the content of the inorganic particles 301 contained in the skeleton 30 is lower than the content of the inorganic particles 301 contained in the first layer 323 .

[0117] The first layer 323 may contain at least one of a first resin and a second resin together with the inorganic particles 301. The second layer 324 contains at least one of the first resin and the second resin. The second resin may be a crosslinked polymer. The second resin is, for example, a thermosetting resin. Examples of thermosetting resins are as described above. The flow temperature of the first resin may be higher than that of the resin particles used to form the voids. The flow temperature of the second resin may also be higher than that of the resin particles. The resin particles used to form the voids may not remain in the composite material 300, but may remain in the voids 40 as shrunken particles 60. The flow temperature is, for example, the temperature at which the resin begins to flow out. The flow temperature can be analyzed, for example, by a constant rate temperature rise test using a thermal flow evaluation device (flow tester) (Shimadzu Corporation, CFT-500D(PC)).

[0118] In the composite material 300, at least one resin selected from the group consisting of the first resin and the second resin preferably includes a crosslinked polymer.

[0119] The second layer 324 contains, for example, inorganic particles 301 at a lower content than the first layer 323. This configuration allows the content of inorganic particles 301 in the composite material 300 to be reduced. As a result, a composite material 300 that can exhibit excellent thermal conductivity while reducing the amount of inorganic particles 301 used can be obtained. The content of inorganic particles 301 contained in the second layer 324 and the first layer 323 can be compared using, for example, SEM-EDX, a method described below. Specifically, the second layer 324 is analyzed using SEM-EDX to calculate the proportion P [atomic %] of atoms derived from the inorganic particles 301. Similarly, the first layer 323 is analyzed to calculate the proportion Q [atomic %] of atoms derived from the inorganic particles 301. If P and Q satisfy the relationship P<Q, it can be determined that the content of inorganic particles 301 contained in the second layer 324 is lower than the content of inorganic particles 301 contained in the first layer 323. In the composite material 300, P and Q may satisfy the relationship P / Q≦0.3.

[0120] The second layer 324 has an average thickness of, for example, 0.01 μm or more and 100.0 μm or less. The average thickness of the second layer 324 may be 0.05 μm or more and 50.0 μm or less, or 0.1 μm or more and 20.0 μm or less. The average thickness of the second layer 324 may be smaller than the average thickness of the first layer.

[0121] The average thickness of the second layer 324 can be determined by observing a cross section of the composite material 300 using, for example, an SEM or the like. Specifically, the average thickness of the second layer 324 can be determined by taking the arithmetic mean of the thicknesses of the second layer 324 at 10 randomly selected locations, or in some cases 30 locations, using an SEM. The average thickness of the first layer 323 can also be determined in a similar manner. The boundaries between the first layer 323 and the skeleton 30 and the second layer 324 can be determined by regarding the layered region in which inorganic particles are present as the first layer 323, which is continuous, in other words, in contact with or adjacent to each other.

[0122] The outer shapes of the voids 40 and 50 may be spherical or substantially spherical. In this specification, "substantially spherical" means that the ratio of the maximum diameter to the minimum diameter (maximum diameter / minimum diameter) is 1.0 or more and 1.5 or less, particularly 1.0 or more and 1.3 or less. However, the outer shapes of the voids 40 and 50 are not limited to a specific shape. The outer shapes may be rod-like, polyhedral, or elliptical, where the ratio is too large to be called spherical. The voids 40 and 50 may be 50% or more, or even 80% or more, spherical. With foaming techniques, the void shapes tend to be irregular, making it difficult to form voids with such uniform shapes.

[0123] The average diameter of the voids 40 is not limited to a specific value. The value is, for example, 50.0 μm or more and 5000.0 μm or less, preferably 100.0 μm or more and 2000 μm or less, and more preferably 300.0 μm or more and 1500.0 μm or less. In this specification, the "average diameter" of the voids 40 means the average value of the diameters determined by observing the cross section of the composite material 300 with an SEM. Specifically, the maximum and minimum diameters of any 100 voids 40 that can be observed in their entirety are measured, and the average value is defined as the diameter of each void. The average value of the diameters of the 15 largest voids is defined as the "average diameter."

[0124] In the composite material 300, the ratio of the volume of the voids 40 to the volume of the composite material 300, that is, the porosity, is not limited to a specific value. The porosity is, for example, 10 vol% or more and 60 vol% or less, preferably 15 vol% or more and 50 vol% or less, and more preferably 20 vol% or more and 45 vol% or less.

[0125] The porosity can be determined by observing the cross section of the composite material 300 using an SEM, calculating the ratio of the total area of ​​the voids 40 to the total area observed, and averaging the ratios for 10 different cross-sectional images. However, only when the manufacturing process is known, the porosity may be determined as follows. The mass of the inorganic particles 301 contained in the composite particles is calculated from the mass of the resin particles described below and the mass of the composite particles in which the inorganic particles 301 are disposed on the surfaces of the resin particles. Separately, the content [mass %] of the inorganic particles 301 in the composite material 300 is calculated by inorganic elemental analysis. The mass of the inorganic particles 301 in the composite material 300 is calculated from the content [mass %] of the inorganic particles 301 and the mass of the composite material 300. The quantity of composite particles used in manufacturing the composite material 300 is calculated from the mass of the inorganic particles 301 in the composite material 300 and the mass of the inorganic particles 301 contained in the composite particles. The volume of the voids 40 is calculated from the average diameter of the voids 40. The total volume of the voids 40 in the composite material 300 is calculated by multiplying the volume of the voids 40 by the number of composite particles. The void ratio is calculated by dividing this value by the volume of the composite material 300.

[0126] The multiple voids 40 may have substantially similar external shapes. In this specification, "substantially similar" means that, by number, 80% or more, particularly 90% or more, of the voids 40 have the same geometric shape, such as a spherical shape or a regular polyhedron shape. The substantially similar external shapes of the multiple voids 40 are preferably spherical. This external shape may be substantially spherical. Multiple voids formed by foaming may also contact each other as they expand. However, in this case, internal pressure generated by foaming usually acts on the void connection points, significantly deforming the vicinity of the connection points. For this reason, foaming techniques are virtually unable to form multiple voids that are in contact with each other and have substantially similar external shapes.

[0127] The porous structure may have through holes extending from one main surface of the composite material 300 to the other main surface. When the composite material 300 is plate-shaped, the voids provided in one main surface of the composite material 300 may be in communication with a space facing the other main surface of the composite material 300. Furthermore, the voids provided in one main surface of the composite material 300 may be in communication with a space adjacent to a side surface of the composite material 300 that intersects with the one main surface. With this configuration, the composite material 300 can achieve both thermal conductivity and breathability. The main surface means the surface of the composite material 300 that has the largest area.

[0128] The plurality of voids 40 may be in contact with each other locally. This makes it difficult for the strength of the composite material 300 to decrease even when the porosity is increased. The diameter of the communicating portion of the voids at the connection portion 315 may be 25% or less, 20% or less, or even 15% or less of the average diameter of the voids 40. The diameter of the communicating portion can be measured by SEM or X-ray CT, as with the average diameter. The connection portions 311 and 313 of the voids 40 are separated by the first layer 323, and therefore no communicating portion exists.

[0129] As shown in FIG. 7 , the composite material 300 has, for example, a plurality of pores 70 on its surface. Specifically, a plurality of pores 70 are formed on surfaces 300a and 300b of the composite material 300. In addition, the average diameter of the pores 70 is, for example, 50.0 μm or more and 5000.0 μm or less. This allows the composite material 300 and a user to have a desired contact area. As a result, the exterior member 10 has flexibility, allowing a user who comes into contact with the exterior member 10 to feel the softness of the exterior member 10. The average diameter of the pores 70 is preferably 100.0 μm or more and 2000.0 μm or less, more preferably 300.0 μm or more and 1500.0 μm or less.

[0130] In this specification, the "average diameter" of the pores 70 refers to the average value of diameters determined by observing the surface of the composite material 300 with an optical microscope. Specifically, the maximum and minimum diameters of any 100 pores 70 that can be observed in their entirety are measured, and the average value is taken as the particle size of each pore. The average value of the particle sizes of the 100 pores is defined as the "average diameter." However, depending on the size of the pores 70, the average diameter may be measured using an SEM instead of an optical microscope. The average diameter of the pores 70 may also be the average diameter of the resin particles described below. Specifically, the maximum and minimum diameters of any 100 resin particles that can be observed in their entirety with an optical microscope are measured, and the average value is taken as the particle size of each resin particle. The average value of the particle sizes of the 100 resin particles may be defined as the "average diameter."

[0131] As is clear from the above description, the composite material 300 may be a non-foamed material. Conventional foamed materials cannot have the characteristic structure shown in Figures 7 and 8, i.e., a structure in which the arrangement of inorganic particles 301 is finely and precisely controlled. In addition, conventional foamed materials cannot have a structure in which a second layer is formed to cover a first layer containing inorganic particles.

[0132] With reference to FIG. 9 , the present specification describes an example of a method for determining measurement positions for determining the composition of each element in the first layer 323, the second layer 324, and the skeleton 30 of the composite material 300 included in the exterior member 10. First, the voids 40 in the composite material 300 are observed using an SEM. The longest diameter of the voids 40 observed using the SEM is measured, and a line segment A having a length L of this longest diameter is defined. Next, a line segment B is defined that passes through the midpoint of the line segment A, is perpendicular to the line segment A, and has a length L' from one end of the void 40 to the other end. Furthermore, a rectangle C is defined with the midpoint of the line segment A as its center of gravity, and has two adjacent sides that are parallel to the line segment A and the line segment B, respectively, and have a length twice that of the parallel line segment A or B (2L in the direction parallel to the line segment A, and 2L' in the direction parallel to the line segment B). The area of ​​this rectangle C excluding the void portion is defined as the measurement area. This measurement area is divided into a plurality of regions D, each defined by a square of 50 μm on each side. The proportion of atoms contained in each of the plurality of regions D is analyzed. For example, energy dispersive X-ray spectroscopy in an ultra-high resolution field emission scanning electron microscope is used for the analysis.

[0133] As a result of the above-described analysis of the plurality of regions D, the region where the proportion [atomic %] of atoms (e.g., B) contained in the inorganic particles is the largest is defined as the measurement position of the composition of the first layer 323. As a result of the above-described analysis of the plurality of regions D, the region where the proportion [atomic %] of atoms (e.g., B) contained in the inorganic particles is the smallest is defined as the measurement position of the composition of the skeleton 30. Meanwhile, the intersection of line segments A and B is defined as the center of gravity, and the region defined by a 50 μm square is defined as region E. This region E is defined as the measurement position in the second layer 324. Note that the atom to be analyzed may be an element of the positive ion of the compound when the inorganic particles are composed of a compound, or may be an element constituting the element when the inorganic particles are composed of a simple substance. For example, when the inorganic particles are boron nitride (BN), the atom to be analyzed is boron (B). When the inorganic particles are alumina (Al ２ O ３ ), the atom to be analyzed is aluminum (Al). If the inorganic particle is graphite, the atom to be analyzed is carbon (C).

[0134] The composite material 300 has a thermal conductivity of, for example, 0.3 W / (m·K) or more. The thermal conductivity of the composite material 300 is more preferably 0.5 W / (m·K) or more. The upper limit of the thermal conductivity is not limited to a specific value. The upper limit may be, for example, 2.5 W / (m·K), 2.2 W / (m·K), or 2.0 W / (m·K). The thermal conductivity of the composite material 300 is a value measured using one test specimen and a symmetrical construction method in accordance with, for example, American Society for Testing and Materials (ASTM) standard D5470-01.

[0135] In the composite material 300, the stress when the composite material 300 is compressed by 30% is, for example, 2.0 N / mm ２ As a result, the composite material 300 in the exterior member 10 has excellent flexibility. The stress when the composite material 300 is compressed by 30% is preferably 1.0 N / mm ２ More preferably, it is 0.5 N / mm ２ or less, and more preferably 0.2334 N / mm ２ less than 0.1 N / mm ２ The lower limit of the stress when the composite material 300 is compressed by 30% is 0.05 N / mm ２ 0.08 N / mm ２ The stress when the composite material 300 is compressed by 30% can be determined, for example, in accordance with JIS K 7181:2011. To measure the stress when the composite material 300 is compressed by 30%, for example, an EZ-test "EZ-S" manufactured by Shimadzu Corporation can be used.

[0136] <Method for Manufacturing Composite Material 300> An example of a method for manufacturing the composite material 300 will be described below. The composite material 300 includes a skeleton 30 containing a first resin and a plurality of voids 40. The method for manufacturing the composite material 300 includes, in order, a step of filling voids in a particle assembly containing a plurality of resin particles with a fluid containing a first resin or a precursor of the first resin, and a step of heating the plurality of resin particles to shrink or remove them, thereby forming a plurality of voids 40. Here, a first layer 323 and a second layer 324 are present on the surfaces of the plurality of resin particles. The first layer 323 and the second layer 324 are arranged such that the second layer 324 is interposed between the surface of the resin particle and the first layer 323, and the surface of the resin particle is in contact with the second layer 324. The first layer 323 also includes a plurality of inorganic particles. The second layer 324 includes at least one resin selected from the group consisting of a first resin and a second resin different from the first resin. At least one resin selected from the group consisting of the first resin and the second resin may include a crosslinked polymer. The flow temperature of the first resin, and, if the second layer 324 includes the second resin, the flow temperature of the second resin, may be higher than the flow temperature of the resin constituting the resin particles.

[0137] First, to obtain composite particles, a mixture of resin particles and an adhesive is prepared. The adhesive includes, for example, at least one of a first resin and a second resin. The adhesive may also include a precursor of at least one of the first resin and the second resin.

[0138] Next, inorganic particles 301 are added to this mixture and mixed to obtain composite particles in which inorganic particles 301 are arranged on the surfaces of multiple resin particles. The step of adding an additive to resin particles to obtain a mixture and the step of adding inorganic particles 301 to this mixture may be repeated multiple times. Alternatively, the additive and inorganic particles 301 may be simultaneously added to a mixture of resin particles and an additive and mixed to obtain composite particles. The mixing method is not limited to a specific method. Examples of mixing methods include mixing using a ball mill, a bead mill, a planetary mixer, an ultrasonic mixer, a homogenizer, a planetary mixer, a rotation-revolution mixer, a fluid mixer, a Henschel mixer, a container-rotating blender, a ribbon blender, and a conical screw blender.

[0139] Next, the composite particles are placed inside a mold so that the composite particles contact each other to form a particle aggregate. A separately prepared fluid is further added to this mold to prepare a mixture. The fluid includes a first resin. The fluid may include a precursor of the first resin. The fluid is filled into the voids of the particle aggregate containing multiple resin particles. The fluid is present at least on the surfaces of the composite particles and in the contact areas between the composite particles. In this way, an aggregate of multiple composite particles is formed in which at least a portion of the multiple composite particles are in contact with each other so that the heat transfer path formed by the inorganic particles 301 in contact with each other extends via the surfaces of the multiple composite particles.

[0140] Next, air bubbles are removed from the mixture. The method for removing air bubbles from the mixture is not limited to a specific method. An example of such a method is degassing under reduced pressure. The degassing under reduced pressure is performed, for example, at a temperature of 25° C. or higher and 200° C. or lower for 1 to 10 seconds.

[0141] The mixture is then heated to reduce the fluidity of the fluid. By heating the fluid, for example, a reaction occurs in which the precursor of the first resin generates the first resin, or the hardening of the first resin progresses, reducing the fluidity. In this way, a skeleton 30 containing the first resin is produced. This results in a precursor of the composite material.

[0142] Next, the resin particles are shrunk or removed from the composite material precursor to produce the composite material 300. The method for shrinking or removing the resin particles from the composite material precursor is not limited to a specific method. Examples of the method include a method of heating the composite material precursor and a method of immersing the composite material precursor in a specific solvent. These methods may be used in combination. This forms the voids 40. In this way, the composite material 300 including the skeleton 30, the first layer 323, and the second layer 324 can be obtained.

[0143] Alternatively, the composite material 300 may be produced as follows. First, composite particles are produced in which an adhesive and inorganic particles 301 are disposed on the surfaces of a plurality of resin particles. The method for producing the composite particles is as described above. Next, the produced composite particles are heated to reduce the fluidity of the adhesive disposed on the surfaces of the composite particles. By heating the adhesive, for example, a reaction occurs in which at least one of the precursors of the first resin and the second resin is produced to produce at least one of the first resin and the second resin, or hardening of at least one of the first resin and the second resin progresses, thereby reducing its fluidity. In this way, a composite particle material is produced that includes first and second layers on the surfaces of resin particles and also includes inorganic particles 301.

[0144] The resin particles are shrunk or removed from the composite particle material to form voids within the material. The method for shrinking or removing the resin particles is as described above.

[0145] Next, the composite particle material with voids formed therein is placed inside a mold. A separately prepared fluid is further added to this mold to prepare a mixture. The method for preparing the mixture is as described above.

[0146] The mixture is then heated to reduce the fluidity of the fluid. The method for reducing the fluidity of the fluid is as described above. In this manner, the composite material 300 including the skeleton 30, the first layer 323, and the second layer 324 can be obtained.

[0147] In the above-described exemplary manufacturing method, the second layer 324 is formed from a resin or its precursor interposed between the surface of the resin particle and the inorganic particle 301. The resin may be the first resin, i.e., the resin contained in the skeleton 30, or a second resin, i.e., a resin different from the first resin. A crosslinked polymer that undergoes crosslinking is suitable as the resin or its precursor. In this exemplary manufacturing method, it was confirmed that the second layer 324 is not formed when polyethylene glycol, a non-crosslinkable polymer, is used. However, depending on the manufacturing method of the composite material 300, it is possible to form the second layer 324 by relaxing the material restrictions. An example of such a method is a method in which only the second layer 324 containing the resin or its precursor is first formed on the entire surface of the resin particle, and then the first layer 323 is formed.

[0148] The temperature to which the composite material precursor is heated is not limited to a specific temperature as long as it can soften the resin particles. The temperature may be, for example, 95°C or higher and 130°C or lower, or 120°C or higher and 160°C or lower. As described above, the flow temperature of the additive is higher than the flow temperature of the resin particles, for example. Therefore, even if the composite material precursor is heated to soften the resin particles, the additive is less likely to flow. As a result, the second layer 324 is more likely to be formed so as to cover the first layer 323 containing the inorganic particles 301.

[0149] When the precursor of the composite material is immersed in a specific solvent, the solvent is not limited to a specific solvent as long as it does not dissolve the first resin or the second resin and can dissolve the resin particles. Examples of the solvent include toluene, ethyl acetate, methyl ethyl ketone, and acetone.

[0150] The resin particles may have a hollow structure. The hollow portion in the hollow structure may be a single hollow portion or may be composed of multiple hollow portions, like expanded resin beads. When resin particles with a hollow structure are used, the resin constituting the resin particles softens upon heating, causing the hollow portion to disappear or shrink, thereby forming multiple voids 40. However, the hollow structure of the resin particles is not essential. When immersing the precursor of the composite material in a specific solvent, it is preferable that the resin particles dissolve more easily in the solvent than, for example, the first resin or the second resin. This method makes it easier to form voids 40 with the desired shape. Examples of resin particles include polystyrene (PS), polyethylene (PE), polymethyl methacrylate (PMMA), ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), acrylonitrile-butadiene-styrene copolymer (ABS), ethylene-propylene-diene rubber (EPDM), thermoplastic elastomer (TPE), and polyvinyl alcohol (PVA). The first resin is, for example, the resin contained in the skeleton 30 .

[0151] The resin particles are not limited to a specific size. When the resin particles are spherical, their average diameter is, for example, 50.0 μm or more and 5000.0 μm or less, preferably 300.0 μm or more and 2000.0 μm or less, particularly 500.0 μm or more and 1500.0 μm or less. By appropriately adjusting the size of the resin particles, the composite material 300 can have an appropriate porosity. In addition, the composite material 300 can have an appropriate void size. The resin particles may be made of resins of multiple sizes selected from these sizes. In other words, the resin particles may have external shapes that are substantially similar to each other. This allows the composite material 300 to have multiple voids 40 that have external shapes that are substantially similar to each other.

[0152] According to the manufacturing method of the composite material 300 according to this embodiment, a first layer 323 containing the inorganic particles 301 and a second layer 324 covering the first layer 323 from the side opposite to the skeleton 30 and facing the voids 40 can be formed. In addition, a heat transfer path extending across the multiple voids 40 can be formed by the inorganic particles 301.

[0153] According to the method for producing the composite material 300 according to this embodiment, the voids 40 are formed inside the first resin without undergoing a foaming step. In other words, the voids 40 are not formed by foaming.

[0154] EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0155] (Preparation of Polystyrene Beads) 100 parts by weight of pure water, 0.2 parts by weight of tricalcium phosphate, and 0.01 parts by weight of sodium dodecylbenzenesulfonate were added to an autoclave equipped with a stirrer. 0.15 parts by weight of benzoyl peroxide and 0.25 parts by weight of 1,1-bis(t-butylperoxy)cyclohexane were added to the autoclave as initiators to prepare a mixed solution. 100 parts by weight of styrene monomer was added while stirring the mixed solution at 350 rpm. The solution was then heated to 98°C to carry out a polymerization reaction. When the polymerization reaction was approximately 80% complete, the reaction solution was heated to 120°C over 30 minutes. The reaction solution was then maintained at 120°C for 1 hour to prepare a styrene resin particle-containing solution. After cooling the styrene resin particle-containing solution to 95°C, 2 parts by weight of cyclohexane and 7 parts by weight of butane were pressure-charged into the autoclave as blowing agents. The solution was then heated again to 120°C. The solution was then kept at 120°C for 1 hour and then cooled to room temperature to obtain a polymerized slurry. The polymerized slurry was dehydrated, washed, and dried to obtain expandable polystyrene resin particles. The expandable polystyrene resin particles were sieved to obtain expandable polystyrene resin particles having a particle diameter of 0.2 mm to 0.3 mm. The expandable polystyrene resin particles were then sieved using a pressure-type foaming machine (BHP) manufactured by Daikai Kogyo Co., Ltd. to obtain spherical expandable polystyrene beads having an average diameter of 650.0 μm to 1200.0 μm. The expandable polystyrene beads were sieved through JIS test sieves with nominal mesh sizes (JIS Z 8801-1:2019) of 1.18 mm and 1.0 mm. The expandable polystyrene beads that passed through the sieve with a nominal mesh size of 1.18 mm and those that did not pass through the sieve with a nominal mesh size of 1.0 mm were used in subsequent tests. The bulk density of the expanded polystyrene beads is 0.025 g / cm ３ It was.

[0156] Example 1: A silicone resin precursor was prepared by mixing components A and B of Dow Chemical's DOWSIL SE 1896 FR A / B adhesive in a 1:1 weight ratio. 7.5 parts by weight of this silicone resin precursor was prepared per 1 part by weight of expanded polystyrene beads. Separately, a filler mixture was prepared by mixing 13.3 parts by weight of flaky boron nitride (aspect ratio 20) and 1.3 parts by weight of graphite (aspect ratio 12) per 1 part by weight of expanded polystyrene beads.

[0157] One part by weight of the spherical expanded polystyrene beads described above was added to a Kawata high-speed fluid mixer (SMP-2). Next, 0.3 parts by weight of the silicone resin precursor described above was added, and the mixture was stirred at 1,000 rpm for 1 minute. The remaining silicone resin precursor and the filler mixture described above were simultaneously added to this mixture, and the silicone resin precursor and filler mixture were added in equal amounts over 30 minutes, while the mixture was stirred at 1,000 rpm using the mixer described above. Through the above operation, expanded polystyrene beads coated with boron nitride and graphite via the silicone resin precursor were obtained. The polystyrene beads were heated in a constant temperature bath at 80°C for 2 hours to cure the silicone resin, yielding polystyrene beads (composite particles) coated with boron nitride and graphite.

[0158] A thermosetting resin was prepared by mixing the A and B components of Dow Chemical's DOWSIL SE 1817 CV M and silicone oil (KF-96-300CS) in a weight ratio of 37.5:37.5:25.

[0159] The thermosetting resin used was Dow Chemical Company's DOWSIL SE 1817 CV M (Parts A and B) and silicone oil (KF-96-300CS). The thermosetting resin was prepared by mixing Parts A, B, and silicone oil in a weight ratio of 37.5:37.5:25.

[0160] The above-mentioned polystyrene beads coated with boron nitride and graphite were packed into a plastic case having an inner diameter of 95 mm × 95 mm × 24 mm, and a plain woven wire mesh (diameter: 0.18 mm, 50 mesh) manufactured by Yoshida Takashi Stainless Steel Co., Ltd. was laid inside the plastic case. A stainless steel punched metal (diameter: 5 mm, thickness: 1 mm, pitch: 8 mm) was further laid on top of that and fixed in place with clamps.

[0161] The aforementioned thermosetting resin was added to this plastic case and degassed under reduced pressure. The gauge pressure at this time was -0.08 MPa to -0.09 MPa. This operation was repeated three times to impregnate the thermosetting resin between the polystyrene beads. Next, the silicone resin was cured by heating at 80°C for two hours, resulting in a resin molded product containing polystyrene beads. This resin molded product was cut to the specified dimensions. This was immersed in acetone for 30 minutes to dissolve the polystyrene beads and allow them to flow out of the resin molded product. The resin molded product was then heated at 90°C to volatilize the acetone, thereby producing a composite material constituting the exterior member of Example 1.

[0162] Example 2 A composite material was obtained in the same manner as in Example 1, except that alumina particles (CB-P05) (spherical, aspect ratio 1) manufactured by Showa Denko K.K. were used as the inorganic particles instead of scaly boron nitride (aspect ratio 20) and graphite (aspect ratio 12), and 50 parts by weight of the inorganic particles were mixed with 1 part by weight of expanded polystyrene beads to prepare a filler mixture.

[0163] Example 3 As an exterior member according to Example 3, one made of Hypersoft (6550H) acrylic polymer manufactured by 3M Company was used.

[0164] Example 4 As an exterior member according to Example 4, a member made of silicone rubber (K-125) manufactured by Togawa Rubber Co., Ltd. was used.

[0165] Comparative Example 1 As an exterior member according to Comparative Example 1, an exterior member made of aluminum alloy A5052 was used.

[0166] Comparative Example 2 As an exterior member according to Comparative Example 2, a member made of soft urethane foam was used.

[0167] Comparative Example 3 As an exterior member according to Comparative Example 3, an exterior member made of Eptsealer (No. 6800) manufactured by Nitto Denko Corporation was used.

[0168] Comparative Example 4 As an exterior member according to Comparative Example 4, one made of chloropropylene rubber was used.

[0169] Fig. 10 is a diagram showing the results of observing, with a scanning electron microscope, a cross section of the composite material 300 in the exterior member 10 according to Example 1. As illustrated in Fig. 10 , in the composite materials according to each Example, a void 40 was formed in the skeleton 30, and a first layer 323 containing inorganic particles and a second layer 324 covering the first layer 323 from the void 40 side were arranged along the periphery of the void 40. Note that, although a single resin material was used in Examples 1 and 2, it is also possible to use different resins for the adhesive and the skeleton, and to configure the skeleton and the second layer to contain different resins.

[0170] (Measurement of Thermal Conductivity) In accordance with American Society for Testing and Materials (ASTM) Standard D5470-01 (unidirectional heat flow steady-state method), the thermal conductivity of the composite materials of Examples 1 and 2 and the composite materials of Comparative Examples 1 to 4 was measured using a Rhesca TCM1001 thermal conductivity measuring device by a heat flow meter method with one test piece and a symmetrical configuration. Specifically, a composite material with a thickness of t = 4000 μm was first cut into a 20 mm × 20 mm size to obtain a test piece. Silicone grease (SHC-20, thermal conductivity: 0.84 W / (m·K)) manufactured by Sanhayato Corporation was applied to both main surfaces of the test piece to a silicone grease layer thickness of 100 μm. An upper rod with a heating block (80°C) and a lower rod with a cooling block (20°C) were used as standard rods. An oxygen-free copper block was used as the test block. A test piece was sandwiched between oxygen-free copper blocks with a silicone grease layer between them to prepare a measurement sample. The test piece was then sandwiched between an upper rod and a lower rod. Heat was applied in the thickness direction of the test piece.

[0171] The temperature difference ΔT between the upper and lower surfaces of the test piece Ｓ was determined according to the following formulas (1) and (2). In formulas (1) and (2), ΔT Ｃ is the temperature difference between the upper surface of the upper layer and the lower surface of the lower layer of the oxygen-free copper block (test block). １ is the heat flux [W / m] determined by the temperature gradient calculated based on the temperature difference at multiple temperature measurement points on the upper rod. ２ ], and q ２ is the heat flux [W / m] determined by the temperature gradient calculated based on the temperature difference at multiple temperature measurement points on the lower rod. ２ ]. ｂ is the sum of the thicknesses of the oxygen-free copper blocks. ｂ is the thermal conductivity of the oxygen-free copper block.

[0172] ΔT Ｓ = ΔT Ｃ -(q Ｓ ×t ｂ ) / k ｂ ... Formula (1) q Ｓ = (q １ +q ２ ) / 2... Formula (2)

[0173] Thermal conductivity λ in the thickness direction of the test piece １ [W / (m·K)] was determined according to the following formula (3).

[0174] λ １ =q Ｓ ×t / ΔT Ｓ ... Formula (3)

[0175] (Measurement of stress when compressed by 30%) Using a small tabletop testing machine EZ-test "EZ-S" manufactured by Shimadzu Corporation, stress was measured when pressure was applied by an indenter to the exterior members according to Examples 1 to 4 and each of Examples 1 to 4, causing a 30% compression. Specifically, in Examples 1 and 2, the pressure E (compressive stress) [N / mm] measured after compressing the main surface of an exterior member having a thickness of 3 mm and a main surface area of ​​10 mm × 10 mm by 30% in the thickness direction at a pressing speed of 0.5 mm / min was ２The main surface of the exterior member refers to the surface of the exterior member to which pressure is applied by the indenter. In Examples 3 and 4, and Comparative Examples 1 to 4, the main surface of a composite material having a thickness of 5 mm and an area of ​​10 mm x 10 mm was compressed by 30% in the thickness direction at a pressing speed of 0.5 mm / min, and then the pressure E (compressive stress) [N / mm ２ The indenter used in the small tabletop testing machine EZ-test had a diameter of 25 mm.

[0176] (Measurement of strain rate during unloading) In order to evaluate the restorability of the exterior members according to Examples 1 to 4 and Comparative Examples 1 to 4, in the examples shown in this specification, the strain rate during unloading of the exterior members was measured.

[0177] The item to be evaluated for the resilience of the object is the compression recovery rate, which is the rate at which the exterior member 10 recovers to 67% of the compression amount when unloaded after being compressed by 30%. However, it is difficult to directly measure the compression recovery rate itself. Therefore, here, the compression recovery rate is assumed to be approximately equal to the strain rate, and the resilience of each object when unloaded is evaluated by measuring the strain rate. The strain rate is the rate at which the indenter rises as the object recovers when unloaded from a compressed state, divided by the thickness of the object in its uncompressed state. Regarding resilience, after applying pressure to the object with the indenter to compress it, it is preferable that the object recovers to a thickness of at least half of its original uncompressed thickness immediately after unloading, and more preferably to a thickness of at least two-thirds (67%) of its original thickness.

[0178] The method for measuring the strain rate will be described in detail with reference to Fig. 11. Fig. 11 is a diagram showing an example of the relationship between the restorability of the exterior member 10 when unloaded and the strain rate. As with the stress measurement, the strain rate was measured using a small bench-top testing machine EZ-test "EZ-S" manufactured by Shimadzu Corporation. The horizontal axis of Fig. 11 represents the position of the indenter in the small bench-top testing machine EZ-test, and the vertical axis represents the measured stress value obtained from the small bench-top testing machine EZ-test.

[0179] Position P0 represents the position of the indenter before contacting the object and applying pressure, i.e., the original position of the object surface. Position P1 represents the position of the indenter at 30% compression. Position P2 represents the position of the indenter when the measured stress value becomes almost zero when the indenter is moved away from the object surface (positive direction of the horizontal axis) from the 30% compressed state and unloaded. In other words, position P2 represents the position of the indenter when the displacement of the object surface due to restoration cannot keep up with the movement of the indenter, and the indenter is separated from the object surface and enters a non-contact state.

[0180] Graphs G1 and G2 show the relationship between the position of the indenter and the stress. Graphs G1 and G2 differ in the speed at which the indenter is moved from the surface of the compressed object. Graph G1 shows the case where the indenter is moved at a slow speed, while graph G2 shows the case where the indenter is moved at a faster speed than in graph G1. In graph G2, the stress becomes almost zero at an earlier timing than in graph G1, and the object cannot keep up with the movement of the indenter to restore its original thickness. In the examples shown in this specification, the measured value of the strain rate was the speed at which the indenter was moved, at which the thickness of the object when the stress became almost zero due to the movement of the indenter, was restored to 67% or more of its original thickness.

[0181] Pressure was applied to each of the exterior members of Examples 1 to 4 and Comparative Examples 1 to 4 using an indenter, resulting in a 30% compression, and the strain rate was measured when the load was released. In the measurements, each of the exterior members of Examples 1 to 4 and Comparative Examples 1 to 4 was fixed to a mounting table with double-sided tape. In addition, to prevent the indenter from adhering, a resin film with a thickness of 12.5 μm was placed between the indenter and the object, and measurements were performed.

[0182] (Measurement of specific gravity) The specific gravity of each of the exterior members according to Examples 1 to 4 and Comparative Examples 1 to 4 was calculated by calculating the density of the exterior member from the dimensions (thickness of the exterior member × area of ​​the main surface) measured with a dial gauge and the mass measured with an electronic balance, and then calculating the specific gravity as a value relative to the density of water (1.0 g / cm).

[0183] (Evaluation Results) Table 1 shows the measurement results of thermal conductivity, compressive stress, strain rate, and specific gravity, as well as the evaluation results of heat dissipation, softness, and restorability for each of Examples 1 to 4 and Comparative Examples 1 to 4. In the evaluation results, "◯" indicates good, and "×" indicates not good. In addition, "-" in the measurement results indicates that it could not be measured, and "-" in the evaluation results indicates that it could not be evaluated.

[0184]

[0185] As shown in Table 1, Examples 1 and 2 obtained good results in terms of heat dissipation, softness, and restorability. Examples 3 and 4 obtained good results in terms of heat dissipation and softness, but poor results in restorability. In other words, it was found that the exterior members according to Examples 3 and 4 are soft and therefore easily deformed, but take time to return to their original state after deformation. Comparative Example 1, being made of metal, has high thermal conductivity and good heat dissipation, but poor results in terms of softness. Furthermore, since metal is hardly deformed in the first place, the restorability of Comparative Example 1 could not be evaluated. Comparative Examples 2 to 4 obtained poor results in terms of heat dissipation.

[0186] Table 2 shows the results of a more detailed evaluation of the restorability of each of Examples 1 to 4 and Comparative Examples 1 to 4. Table 2 shows the evaluation results of the restorability for each strain rate for each of Examples 1 to 4 and Comparative Examples 1 to 4. The restorability refers to the ratio of the thickness of an object restored when unloaded from a compressed state to its original thickness. The larger the percentage value shown in Table 2, the closer the thickness has been restored to the original thickness.

[0187]

[0188] In Examples 1 and 2, the thickness was restored to 67% or more at any strain rate. Therefore, it can be seen that Examples 1 and 2 have high restorability. On the other hand, in Example 3, the thickness was not restored to 67% or more at any strain rate, and in Example 4, the thickness was restored to 67% or more at any strain rate. －１In the case of Example 1, the thickness did not recover to 67% or more. In other words, it can be seen that Example 3 and Example 4 have low recovery properties, and it takes a long time to return to the original state after deformation, or they do not recover to the original state at all. Comparative Example 1 is made of metal, so as mentioned above, it does not deform in the first place. In Comparative Examples 2 to 4, the thickness recovered to 67% or more at all strain rates. Therefore, it can be seen that Comparative Examples 2 to 4 have high recovery properties.

[0189] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0190] Furthermore, all ordinal numbers, quantitative numbers, and other figures used in the above-described embodiments are merely examples for specifically explaining the technology of the present invention, and the present invention is not limited to the exemplified figures. Furthermore, the connection relationships between the components are merely examples for specifically explaining the technology of the present invention, and the connection relationships for realizing the functions of the present invention are not limited to these.

[0191] The robot according to this embodiment is not easily broken because its exterior is soft and reduces the temperature rise in the space surrounded by the exterior material, making it particularly suitable for applications that provide comfort (a sense of security or self-affirmation) by promoting oxytocin secretion in working people living alone, seniors whose children have become independent, frail elderly people receiving home medical care, etc. However, the application is not limited to this, and it can be used for applications that provide comfort to a variety of users.

[0192] The present invention provides, for example, the following aspects: <1> A heat source including an exterior member and a heat source disposed in a space surrounded by the exterior member, wherein the exterior member has a thermal conductivity of 0.3 W / (m·K) or more, and a compressive stress of 2.0 N / mm when the exterior member is compressed by 30%. ２ <2> The robot according to <1>, wherein the specific gravity of the exterior member is 1.5 or less. <3> A compression recovery speed, which is a speed at which the exterior member recovers to 67% of the compressed amount when unloaded after being compressed 30%, is 0.5 s －１The robot according to <1> or <2>, wherein the exterior member includes a composite material, the composite material having a skeleton including a first resin, a plurality of voids, and a plurality of inorganic particles, the plurality of inorganic particles forming heat transfer paths extending along the peripheries of the plurality of voids. <5> The robot according to <4>, wherein the composite material has a first layer and a second layer arranged along the peripheries of each of the plurality of voids, the first layer including the plurality of inorganic particles, and the second layer including at least one resin selected from the group consisting of the first resin and a second resin different from the first resin, and covering the first layer from the side opposite the skeleton and facing the voids. <6> The robot according to <4> or <5>, wherein the composite material has a surface including a plurality of pores, the average diameter of the pores being 50.0 μm or more and 5000.0 μm or less.

[0193] This application claims priority based on Japanese Patent Application No. 2023-130253 filed with the Japan Patent Office on August 9, 2023, and includes the entire contents of this Japanese patent application.

[0194] REFERENCE SIGNS LIST 1 Torso 2 Head 2a Right eye 2b Left eye 2c Mouth 2d Right cheek 2e Left cheek 3 Arm 3a Right arm 3b Left arm 4 Leg 4a Right leg 4b Left leg 10 Exterior member 11 Camera 12 Tactile sensor 13 Control unit 14 Vital sensor 141 Microwave emission unit 142 Microwave reception unit 15 Battery 16 Torso frame 17 Torso mount 21 First capacitance sensor 22 Head frame 23 Head mount 24 Display 241 White of eye 242 Pupil 243 Highlight unit 24a Right eye display 24b Left eye display 25 Speaker 26 Light 26a Right cheek light 26b Left cheek light 27 Head connection mechanism 31 Second capacitance sensor 32a Right arm frame 32b Left arm frame 33 Right arm rest 34a Right arm connection mechanism 34b Left arm connection mechanism 35 Servo motor 35a Right arm servo motor 35b Left arm servo motor 35c Head servo motor 35d Right leg servo motor 35e Left leg servo motor 41a Right leg wheel 41b Left leg wheel 42a Right leg frame 42b Left leg frame 44a Right leg connection mechanism 44b Left leg connection mechanism 100 Robot 101 Acquisition unit 102 Communication control unit 103 Storage unit 104 Authentication unit 105 Registration unit 106 Start control unit 107 Motor control unit 108 Output unit 109 Detection unit 131 CPU DESCRIPTION OF SYMBOLS 132 ROM 133 RAM 134 HDD / SSD 135 Device connection I / F 136 Communication I / F 200 User 201 Light source for imaging 30 Skeleton 40, 50 Void 60 Particle 70 Hole 300 Composite material 300a, 300b Surface 301-305 Inorganic particles 311, 313, 315 Connection portion 323 First layer 324 Second layer 325, 326 Heat transfer path A System bus B Biometric information C1 First capacitance signal C2 Second capacitance signal F1a Right shoulder frame F2a Right upper arm frame F3a Right elbow frame F4a Right forearm frame F1b Left shoulder frame F2b Left upper arm frame F3b Left elbow frame F4b Left forearm frame F1c Neck frameF2c Face frame Im Photographed image L Irradiated light Ms Emitted wave Mr Reflected wave M1a Right shoulder servo motor M2a Right upper arm servo motor M3a Right elbow servo motor M4a Right forearm servo motor M1b Left shoulder servo motor M2b Left upper arm servo motor M3b Left elbow servo motor M4b Left forearm servo motor M1c Neck servo motor M2c Face servo motor Im Photographed image S Tactile signal

Claims

1. A heat source is provided in a space surrounded by an exterior member, the thermal conductivity of the exterior member is 0.3 W / (m·K) or more, and the compressive stress when the exterior member is compressed by 30% is 2.0 N / mm ２ Below is the robot.

2. The robot according to claim 1, wherein the specific gravity of the exterior member is 1.5 or less.

3. The compression recovery speed, which is the speed at which the exterior member recovers to 67% of the compressed amount when the load is removed after being compressed by 30%, is 0.5 s －１ The robot according to claim 1 or 2.

4. The robot according to claim 1 or claim 2, wherein the exterior member is comprised of a composite material, the composite material having a skeletal portion containing a first resin, a plurality of voids, and a plurality of inorganic particles, the plurality of inorganic particles forming heat transfer paths extending along the periphery of the plurality of voids.

5. The robot described in claim 4, wherein the composite material has a first layer and a second layer arranged along the periphery of each of the plurality of voids, the first layer contains the plurality of inorganic particles, and the second layer contains at least one resin selected from the group consisting of the first resin and a second resin different from the first resin, and covers the first layer from the side opposite the skeleton and faces the voids.

6. The robot according to claim 4, wherein the composite material has a plurality of pores on the surface, and the average diameter of the pores is 50.0 μm or more and 5000.0 μm or less.