Power adapter

Abstract

The invention relates to a power adapter, and provides a power adapter which is not easy to fall off from an AC socket, is not easy to damage a USB cable, and is easy to arrange even in a narrow space. A power adapter (10) is provided with: a power plug (120) that can be inserted into an AC socket; a USB port unit (130) capable of supplying power to a USB device; a socket unit (140) capable of supplying power to another device; a housing (100) of a substantially rectangular parallelepiped shape has a front surface (101), a back surface (102), an upper surface (103), a lower surface (104), a right surface (105) and a left surface (106). The power plug part (120) is arranged on the upper surface (103) side of the back surface (102) of the housing (100), the housing (100) is arranged on the lower surface side (104) or the upper surface (103) side of the front surface (101), and the USB port part (130) is arranged on the side surface (111) of the step part (110) which is approximately orthogonal to the front surface (101).

Description

Technical Field

[0001] The present invention relates to a power adapter that can supply power to a USB device. Background Art

[0002] As a power adapter that can supply power to a USB device, the following power adapters have been proposed. For example, Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2017-16948) proposes a power supply unit that can supply power to other electrical devices even in an environment where there is only one power outlet, and can also use electronic devices that require USB power supply even in an environment where there is no power outlet.

[0003] In the power supply unit described in Patent Document 1, a first AC auxiliary power socket and a second AC auxiliary power socket that are electrically connected to a power plug are provided in a portion of the lower case of the power supply unit main body adjacent to the power plug. A power plug for inserting into an AC power outlet is provided on one end side of the lower case. A USB port is provided on the other end side of the lower case, and this USB port serves as a port for supplying power to electronic devices such as a speaker for a personal computer. The power output from the power plug or the power output from the battery is selectively output to the USB port via a circuit 15.

[0004] Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2014-75349) proposes a power outlet that can be partially rotated. By setting the USB socket to a rotatable structure, the use range of the USB insertion port can be expanded.

[0005] The power outlet described in Patent Document 2 includes: a main body that has an insertion port on one surface and a plug on the other surface and has at least one rotating shaft member; a rotating body that is pivotally connected to the main body by this rotating shaft member and horizontally rotates at an arbitrary angle about the vertical direction X axis in the main body; and at least one USB insertion port that is provided at the center of the horizontal direction Y axis in the rotating body and rotates in conjunction with the rotating body for supplying power to an electronic device.

[0006] Patent Document 3 (Japanese Unexamined Patent Application Publication No. 2011-138738) proposes a power outlet that can be partially rotated. By setting the USB socket to a rotatable structure, the use range of the USB insertion port can be expanded.

[0007] The power outlet described in Patent Document 3 includes: a main body having at least one rotating shaft member; at least one set of insertion ports provided on the main body; a rotating body that is pivotally connected to the main body by this rotating shaft member and rotates about the rotating shaft member; and at least one USB insertion port provided on the rotating body and rotating in conjunction with the rotating body.

[0008] Patent Document 4 (Japanese Utility Model Registration No. 3141303) discloses a flat plug strip with a USB port and a USB power supply function.

[0009] The flat plug strip described in Patent Document 4 includes: a flat plug strip housing 1 formed by joining an upper housing and a lower housing; a recess 1a formed in the flat plug strip housing 1; a blade holder 2 rotatably mounted in the recess 1a; a pair of metal blades 3 protruding from the blade holder 2; a metal spring piece 4 electrically connected to the pair of metal blades 3; a spring piece protection cover 5 provided with a plug insertion port for inserting a plug into a spring piece portion 4a of the metal spring piece 4, the spring piece portion 4a of the metal spring piece 4 being provided on both side surfaces of the flat plug strip housing 1 orthogonal to the recess 1a, and a USB board 6 electrically connected to the metal spring piece 4 is built into the flat plug strip, and a USB insertion port 6a is provided on a side surface of the flat plug strip housing 1 parallel to the recess 1a. Prior Art Documents Patent Documents

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-16948 Patent Document 2: Japanese Patent Application Laid-Open No. 2014-75349 Patent Document 3: Japanese Patent Application Laid-Open No. 2011-138738 Patent Document 4: Japanese Utility Model Registration No. 3141303 Summary of the Invention Technical Problem to be Solved by the Invention

[0011] Generally, a power adapter is connected to an AC outlet installed on a wall or the like and is further used for the purpose of supplying power to various USB devices such as mobile phones. Conventional USB terminals are designed for information communication, and the bus power that can be supplied via USB is limited to low power. Therefore, the devices that can be powered via USB are limited, and generally each device requires a dedicated power adapter. For example, in a laptop computer, each manufacturer bundles or sells a dedicated power adapter, and the user needs to connect the power adapter of each device to the AC outlet. However, in recent years, standards such as the USB Power-Delivery (USB PD) protocol have been designed, and since then, power can be supplied to various devices through a USB connection, and in addition to mobile phones, power can also be supplied to high-power devices such as tablet computers, laptop computer bodies, monitors, and projectors via USB. In this case, the user no longer needs to carry a dedicated power adapter for each device as before, but can use a single USB power adapter to use various devices in different places. In particular, existing USB power adapters have mainly been used for charging the batteries of small devices such as mobile phones, etc., but in the future they will also be used for laptop computers, etc., and not only for charging, but the frequency of use for power supply to make the device work will increase. Thus, although in the past, for example, the power adapter was inserted into an AC outlet near the floor and used to charge a mobile phone placed on the floor or beside the pillow in many cases, the situation of operating a USB device from a place slightly farther away from the power adapter, such as powering a laptop computer or a projector on a table, is becoming more common. And because these USB devices are not fixed devices, when the USB device is slightly moved, the USB cable also moves, and thus the problem that the power adapter is likely to fall off the AC outlet easily occurs.

[0012] In addition, in recent years, services providing AC power have been increasing in various places such as cafes or train seats, etc. However, due to space constraints, etc., the AC outlet is not necessarily provided only on the vertical wall surface, and there are also cases where the AC outlet is provided on a wall surface inclined relative to the vertical direction, such as the back of the table top plate or the front end part of the seat armrest, etc. In this case, due to the structure of the power plug of the power adapter, the main body of the power adapter is supported in the air, and thus the problem that the power adapter is more likely to fall off the AC outlet easily occurs. In particular, in the case where the power adapter is installed in a place with vibration such as in a train, etc., the problem that the power adapter is likely to fall off the AC outlet becomes obvious.

[0013] In addition, a holding portion is provided between the connection port and the cable of the USB cable. Therefore, when the USB cable is connected to the power adapter, the holding portion protrudes from the power adapter. Thus, there is a problem that the user may hook the holding portion and damage the USB cable. In addition, when trying to install the power adapter in a narrow space, there is a problem that the protruding holding portion is likely to interfere with the surrounding area such as the floor surface.

[0014] The plug portion (power plug) of the power supply unit in Patent Document 1 is rotatable relative to the housing, and the housing is provided with a power plug insertion port (socket portion) and a USB port. However, since the USB port is provided on the surface of the rectangular parallelepiped housing, and the plug portion and the USB port are respectively provided on the two faces of the housing that are the farthest apart, there is a problem that when the USB cable is slightly moved, the housing will shake, and thus the plug portion is likely to fall off the AC outlet easily. In addition, since the holding portion of the USB cable protrudes from the housing, there is a problem that it is easily hooked by the user and it is also difficult to place it in a narrow place. In addition, although the power plug insertion port is rotatable relative to the housing, the precondition is that the housing is provided along a vertical wall surface. When the housing is provided in an AC socket mounted on a non-vertical surface such as an inclined surface, there is a problem that it is prone to fall off.

[0015] The USB insertion ports (USB port parts) of the power sockets in Patent Documents 2 and 3 are configured to be rotatable relative to the main body. However, in Embodiment 1 and the like, the relationship between the plug and the USB insertion port in the main body is not described. And in Embodiment 4 and the like, the USB insertion port is arranged diagonally to the plug in the cross-section of the main body. Therefore, there is a problem that when the USB cable is slightly moved, the housing will shake, and thus the plug part is prone to fall off from the AC socket. In addition, since the holding part of the USB cable protrudes from the housing, there is a problem that it is easy to be hooked by the user and it is also difficult to place it in a narrow place. In addition, although the plug is rotatable relative to the main body (Embodiment 4), the precondition is that the main body is provided along a vertical wall surface. Therefore, when the plug is provided in an AC socket mounted on a non-vertical surface such as an inclined surface, there is a problem that it is prone to fall off.

[0016] The flat plug strip with a USB power supply function in Patent Document 4 has a metal plug piece (power plug part) and a USB insertion port that are rotatable in the flat socket housing. However, since the USB insertion port is provided on the surface of the rectangular parallelepiped flat plug strip housing, and the metal plug piece and the USB insertion port are respectively arranged on the two farthest surfaces of the flat plug strip housing, there is a problem that when the USB cable is slightly moved, the housing will shake, and thus the metal plug piece is prone to fall off from the AC socket. In addition, since the holding part of the USB cable protrudes from the housing, there is a problem that it is easy to be hooked by the user and it is also difficult to place it in a narrow place. In addition, although the metal plug piece is rotatable relative to the flat plug strip housing, when the metal plug piece is provided in an AC socket mounted on a non-vertical surface such as an inclined surface, there is a problem that it is prone to fall off.

[0017] Therefore, an object of the present invention is to provide a power adapter that is not prone to fall off from an AC socket. In addition, another object of the present invention is to provide a power adapter in which the USB cable is not easily damaged and is also easy to set even in a narrow space. Technical means for solving the problem (1) The power adapter of the first aspect is a power adapter having a power plug portion that can be inserted into an AC socket, a USB port portion that can supply power to a USB device, and a housing having a substantially rectangular parallelepiped shape with a front surface, a back surface, an upper surface, a lower surface, a right surface, and a left surface. The power plug portion is provided on the upper side of the back surface of the housing and is fixed so as to be rotatable freely at any angle with respect to the housing. A stepped portion is provided on the upper side or the lower side of the front surface of the housing, and the USB port portion is provided on a side surface of the stepped portion that is substantially orthogonal to the front surface.

[0019] In the existing power adapter, the USB port portion is provided on the surface of the housing (mainly the lower surface of the rectangular parallelepiped). Therefore, when the USB device is moved, the elastic USB cable will pull the housing of the power adapter. As a result, a rotational torque is generated around the power plug portion inserted into an AC socket on a wall or the like, and acts with the USB port portion as the acting point. Therefore, there is a problem that the power adapter is likely to fall off from the AC socket even under the influence of a weak force from the USB cable. In the power adapter of the first aspect, the power plug portion is provided on the upper side of the back surface of the housing, and the USB port portion is provided on the side surface of the stepped portion (the surface substantially orthogonal to the front surface), and the stepped portion is provided on the lower side or the upper side of the front surface of the housing. And, since the power plug portion holds the housing by being inserted into an AC socket on a wall or the like, the distance between the power plug portion and the USB port portion is shorter than the case where the USB port portion is provided on the lower surface of the housing, thereby suppressing the influence of the rotational torque received by the housing from the USB cable. Thus, when the USB device is moved, the power plug is not likely to fall off from the AC socket, so that the power adapter can be prevented from falling off from the AC socket. In addition, since it is difficult to be affected by the rotational torque received from the USB cable and the load on the power plug portion is small, even when the power adapter is set in an AC socket installed on a non-vertical surface such as an inclined surface, or when the power adapter is set in a place where vibration is likely such as in a tram, the power adapter can be prevented from falling off from the AC socket.

[0020] In addition, since the power plug portion is fixed so as to be rotatable freely at any angle with respect to the housing, even when the AC socket is installed on a front-inclined wall (a wall inclined with respect to the vertical), the housing of the power adapter can support the power adapter body in the air while maintaining vertical. In this case, the center of gravity of the power adapter and the power plug portion supported by the AC socket are on a vertical line, and the center of gravity of the power adapter does not apply a rotational torque to the power plug portion, so that the power adapter is not likely to fall off from the AC socket. In addition, since the power plug head is fixed to be rotatable freely at any angle relative to the housing, even when a rotational torque is applied to the USB port portion through a USB cable, for example, the housing rotates while the power plug head remains inserted in the AC socket on the wall surface. As a result, the power adapter does not fall off from the AC socket.

[0021] In addition, the USB port portion is provided with a stepped portion on the housing, and the holding portion of the USB cable is received in the stepped portion. Thereby, the risk that a user hooks the holding portion can be reduced, and damage to the USB cable can be prevented. In addition, since the holding portion of the USB cable is received in the stepped portion, it is difficult for the holding portion to interfere with the surroundings such as the floor surface. Thus, the power adapter can be easily installed even in a narrow space.

[0022] It should be noted that in the present invention, for ease of understanding, such terms are used: one side in the housing of the power adapter is taken as the front surface, the other side opposite to the front surface is taken as the back surface, the surfaces adjacent to and opposite to the front surface are taken as the right surface and the left surface, and the upper surface and the lower surface; however, the front surface does not need to be on the indoor space side, and the upper surface does not need to be on the vertically upward side. (2) The power adapter of the second invention is the power adapter according to the invention of the first aspect, and the stepped portion can be configured to be provided on the lower side of the front surface and form a stepped shape by the side surface and the front surface, the side surface being substantially orthogonal to the front surface, the front surface being parallel to the front surface, and being closer to the front surface than the back surface.

[0024] The power adapter of the second invention corresponds to the power adapter of the first embodiment. Thereby, since the stepped portion is provided at a diagonal position away from the power plug head, it becomes easy to arrange the internal components (such as a transformer) of the power adapter on the power plug head side, and it becomes easy to design the center of gravity position of the power adapter main body on the power plug head side. In addition to the torque caused by the USB cable described above, the rotational torque applied to the power adapter also needs to consider the torque applied by the weight of the power adapter itself. In particular, in a space affected by vibration such as inside a train, by designing the position of the center of gravity of the power adapter main body on the power plug head side, the load applied to the power plug head can be reduced, and thus the power adapter can be prevented from falling off from the AC socket. (3) The power adapter of the third invention is the power adapter according to the first aspect, and the stepped portion can be configured to be provided on the upper side of the front surface and form a stepped shape by the side surface and the front surface, the side surface being substantially orthogonal to the front surface, the front surface being parallel to the front surface, and being closer to the front surface than the back surface.

[0026] The power adapter of the third invention corresponds to the power adapter of the second embodiment. In this case, the power plug portion is provided on the upper side of the back surface of the housing, and the USB port portion is also provided on the upper side of the front surface of the housing. Therefore, the distance between the power plug portion and the USB port portion can be minimized. As a result, the magnitude of the rotational torque applied from the USB cable can be minimized, and thus the power adapter can be prevented from falling off the AC outlet. (4) The power adapter of the fourth invention is a power adapter according to any one of the first to third inventions, and may further include a socket portion capable of supplying AC power to other devices. The socket portion may be provided on the front surface of the housing.

[0028] Due to the presence of the socket portion, even when this power adapter occupies the AC outlet, power can be supplied to other AC devices and they can operate. Therefore, even when the number of AC outlets is insufficient, such as in a train, power can be supplied to multiple devices simultaneously. In particular, since the socket portion is provided on the front surface of the housing and the USB port portion is provided on the side surface of the step, the power cord inserted into the socket portion and the USB cable inserted into the USB port portion extend in directions orthogonal to each other. Therefore, the power cord and the USB cable are not easily interfered with each other, and the insertion and removal of the power cord become easy. In addition, if the USB device is moved and a rotational torque is applied to the housing from the USB cable, due to the weight of the power cord itself connected to the power plug portion, the rotational torque acting on the housing is suppressed, and thus the power adapter can be prevented from falling off the AC outlet. (5) The power adapter of the fifth invention is a power adapter according to any one of the first to fourth inventions, and the center of gravity of the power adapter can be configured to be closer to the power plug portion side than the center of the housing.

[0030] The power plug portion is inserted into the AC outlet and holds the housing. Since the rotational torque applied by the weight of the power adapter itself acts around the power plug portion, there is a problem that when vibrations or the like are applied to the power adapter, the power adapter is likely to fall off the AC outlet. The center of gravity of the power adapter of the fifth invention is closer to the power plug portion side than the center of the housing. Therefore, the distance between the fulcrum and the point of application of the torque applied by the center of gravity becomes shorter, and thus the falling off caused by vibrations or the like can be prevented. Therefore, even when the power adapter is installed in a place with vibrations, such as in a train or a car, the power adapter is not easily fallen off the AC outlet. (6) The power adapter of the sixth invention is the power adapter according to any one of the first to fifth inventions, and the length N of the stepped portion in the long side direction of the housing may be 1.5 cm or more.

[0032] Thereby, the holding portion of the USB cable can be accommodated in the stepped portion, so that the risk of the user hooking the holding portion can be reduced, and thus the damage of the USB cable can be prevented. In addition, the power adapter can be such that its holding portion hardly interferes with the surroundings such as the floor surface, and it is also easy to set even in a narrow space. (7) The power adapter of the seventh invention of the present invention is the power adapter according to any one of the first to sixth inventions, and the housing may be provided with a storage portion capable of storing the power plug head. The power plug head may be supported by an axis parallel to the side intersecting the upper surface and the back surface, and may be fixed to be rotatable relative to the housing by any angle, and the range of the angle by which the power plug head can be rotated may be greater than 90° and not greater than 180°.

[0034] By providing the housing with a storage portion capable of storing the power plug head, when carrying the power adapter, the power plug head can be stored in the storage portion, which is very convenient. In addition, by setting the angle of the power plug head during storage to 0° and setting the range of the rotatable angle to be greater than 90° and not greater than 180°, even when the wall surface where the AC socket is provided is a vertical surface, the power adapter can be fixed parallel to the wall surface. (8) The power adapter of the eighth invention is the power adapter according to any one of the first to seventh inventions, and the cross-section of the corner portions on the right and left sides of the housing that support the power plug head may be an arc shape; the power plug head may have a metal plug and a plug base that supports the metal plug; and the center of the arc forming the arc shape may coincide with the rotation center of the plug base, and the radius r of the arc forming the arc shape and the perpendicular distance L from the rotation center of the plug base to the connection surface connected to the opposing socket may be the same length.

[0036] Therefore, since the radius r of the arc forming the arc shape of the housing is the same as the perpendicular distance L from the rotation center of the plug base to the connection surface, when the power plug head is rotated, the connection surface of the plug base always coincides with the tangent of the arc shape of the housing. Therefore, since the wall surface provided with the AC socket is in close contact with the connection surface of the plug base of the power adapter, and at the same time a certain corner portion of the power plug head is in contact with the wall surface of the AC socket, it becomes easy to fully insert the metal plug of the power plug head into the AC socket. In addition, when a rotational torque is applied to the USB port portion through a USB cable, the housing can rotate while the corner portion of the housing remains in contact with the wall surface, thereby preventing the power adapter from falling off. Similarly, when a rotational torque in the left - right direction is applied to the USB port portion, a corner portion (arc - shaped) of either the right - hand or left - hand power plug portion contacts the wall surface of the AC socket. Therefore, compared with the case where only the power plug portion contacts the wall surface, the power adapter is less likely to fall off from the AC socket. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 FIG. is a schematic perspective view for explaining the power adapter of the first embodiment. Figure 2 FIG. is a schematic perspective view of the power adapter of the first embodiment as viewed from another side. Figure 3 FIG. is a schematic explanatory view for explaining the arc - shaped portions of the power plug portion and the housing of the power adapter of the first embodiment. Figure 4 FIG. is a schematic explanatory view for explaining the operation of the power adapter when a force is applied to the power adapter from a USB cable in the first embodiment. Figure 5 FIG. is a schematic plan view for explaining a modification of the first embodiment. Figure 6 FIG. is a schematic plan view for explaining another modification of the first embodiment. Figure 7 FIG. is a schematic explanatory view for explaining the usage state of the first embodiment. Figure 8 FIG. is a schematic perspective view for explaining the second embodiment. REFERENCE SYMBOL LIST

[0038] 10: Power adapter; 100: Housing; 101: Front surface; 102: Rear surface; 103: Upper surface; 104: Lower surface; 105: Right surface; 106: Left surface; 110: Step portion; 111: Side surface; 112: Front side; 120: Power plug portion; 121: Metal plug; 122: Plug base; 123: Connection surface; 124: Storage portion; 130: USB port portion; 140: Socket portion; M: Center of gravity. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] [First Embodiment] The power adapter 10 of the first embodiment is a portable power adapter for users. By inserting the power plug portion 120 into a household AC socket (alternating current power supply), a DC power supply can be supplied from the USB port portion 130 to power a USB device. As Figure 1and Figure 2 As shown in Figure 2 , the power adapter 10 of the first embodiment includes: a power plug portion 120 that can be inserted into an AC outlet; a USB port portion 130 that can supply power to a USB device; a socket portion 140 that can supply power to other devices; and a housing 100 having a substantially rectangular parallelepiped shape, with a front surface 101, a back surface 102, an upper surface 103, a lower surface 104, a right surface 105, and a left surface 106. The socket portion 140 is provided on the front surface 101 of the housing 100. In addition, a stepped portion 110 is provided on the front surface 101 of the housing 100, and the USB port portion 130 is provided on a side surface 111 of the stepped portion 110 that is substantially orthogonal to the front surface 101.

[0040] The power plug portion 120 has: a metal plug 121 made of metal and electrically connected to the AC outlet; and a plug base 122 that supports the metal plug 121 and is rotatably fixed to the housing 100. The plug base 122 of the power plug portion 120 is supported by an axis in the left - right direction of the housing 100 and is fixed to be rotatable 180°. When the power adapter 10 is connected to an AC outlet mounted on a wall surface W, as Figure 2 shown, the power plug portion 120 is opened at an angle of 180° and used perpendicular to the back surface 102. On the other hand, as Figure 3 shown, when the power adapter 10 is connected to an AC outlet mounted on an inclined surface, the power plug portion 120 is opened at an appropriate angle corresponding to the inclined surface and used. In addition, when the power adapter 10 is not in use, the power plug portion 120 can be easily stored or carried by being housed in a storage portion 124 (angle is 0°).

[0041] (Stepped portion 110) The stepped portion 110 is provided on the lower surface 104 side of the front surface 101 of the housing 100 and forms a stepped shape by a side surface 111 and a front surface 112. The side surface 111 is substantially orthogonal to the front surface 101, the front surface 112 is parallel to the front surface 101, and is closer to the front surface 101 than the back surface 102. The USB port portion 130 is provided on the side surface 111. By connecting a USB cable 20 to the USB port portion 130, power can be supplied to a USB device. As Figure 3 shown, the length N of the front surface 112 of the stepped portion 110 in the long - side direction of the power adapter 10 is preferably 1.0 cm or more, more preferably 1.5 cm or more, and even more preferably 1.8 cm or more. In addition, the length N is preferably 4.0 cm or less, and more preferably 3.0 cm or less. By making the length N equal to or greater than the above-mentioned lower limit value, the holding portion of the USB cable 20 can be accommodated in the stepped portion 110. Therefore, the risk of the user hooking the holding portion can be reduced, and thus damage to the USB cable 20 can be prevented. In addition, the power adapter 10 can be arranged such that its holding portion hardly interferes with the surroundings such as the floor surface, and can be easily set even in a narrow space. In addition, by making the length N equal to or less than the above-mentioned upper limit value, an excessive increase in the size of the entire housing 100 can be prevented. In addition, by providing a USB port portion 130 on the side surface 111 of the stepped portion 110 and a socket portion 140 on the front surface 101 of the housing 100, the power cable inserted into the socket portion 140 and the USB cable 20 inserted into the USB port portion 130 extend in directions orthogonal to each other. Therefore, the power cable and the USB cable 20 are not likely to interfere with each other, and the insertion and removal of the power cable become easy.

[0042] It should be noted that, in the present embodiment, although an example is shown in which the USB port portion 130 is provided only on the side surface 111 of the stepped portion 110 and the socket portion 140 is provided only on the front surface 101 of the housing 100, the present invention is not limited thereto, and the USB port portion 130 and / or the socket portion 140 can be appropriately added on any surface such as the right surface 105, the left surface 106, and the front surface 101 of the housing 100.

[0043] (Power plug portion 120) Figure 3 It is a schematic explanatory view for explaining the power plug portion 120 of the power adapter 10 and the arc shape of the housing 100. Reference Figure 1 And Figure 3 As shown in FIGS. 18 and 19, the housing 100 includes a storage portion 124 for storing the power plug portion 120. The power plug portion 120 includes a plug base portion 122 and a metal plug 121. The plug base portion 122 is supported by an axis parallel to the edge where the upper surface 103 and the rear surface 102 of the housing 100 intersect. In addition, the cross-sections of the corner portions on the right and left sides of the housing that axially support the power plug portion are arc-shaped. The center of the arc forming the arc shape coincides with the rotation center of the plug base portion 122, and the radius r of the arc forming the arc shape is the same as the perpendicular distance L from the rotation center of the plug base to the connection surface connected to the opposing socket. With the above structure, when the power plug head 120 rotates, the connection surface 123 of the plug base 122 always coincides with the tangent of the arc shape of the housing 100, and the wall surface W equipped with the AC socket also always contacts the connection surface 123 of the plug base 122 of the power adapter 10 and the tangent of the arc shape of the housing 100. Therefore, the metal plug 121 of the power plug head 120 can be easily and fully inserted into the AC socket. In addition, when a rotational torque is applied in one direction (the left - right direction when viewed from the front) through the USB cable 20, the housing 100 contacts the wall surface W due to its arc shape, and the power adapter 10 can also be prevented from falling off.

[0044] Figure 4 It is a schematic explanatory diagram for explaining the operation of the power adapter 10 when a force is applied to the power adapter 10 from the USB cable 20 in the first embodiment. In Figure 4 the power adapter 10 is inserted into an AC socket installed on a wall surface W inclined with respect to the vertical direction. First, in Figure 4 the state where neither the upper surface 103 nor the rear surface 102 of the power adapter 10 in (a) contacts the wall surface W, a force F1 is applied to the USB port portion 130 through the USB cable 20. In this case, since the radius r of the arc forming the arc shape and the vertical distance L from the rotation center of the plug base 122 to the connection surface 123 connected to the opposing socket are of the same length, the power adapter 10 rotates about the rotation center of the plug base 122 under the influence of the rotational torque of the force F1 and becomes Figure 4 the state of (b). In Figure 4 the case of further applying the force F1 to the USB port portion 130 in the state of (b), the rotational torque caused by the force F1 is applied to the fulcrum in the figure, and at the same time, a force F2 is applied to the metal plug 121 of the power plug head 120. When this force F2 is greater than the frictional force of the metal plug 121, the power adapter 10 falls off from the wall surface W. When the distance between the fulcrum and the USB port portion 130 is set as a, and the distance between the fulcrum and the metal plug 121 is set as b, the magnitude of this force F2 is F2 = F1×a÷b. Since the fulcrum is located on the upper surface 103 of the power adapter 10, the shorter the distance between the upper surface 103 and the USB port portion 130, the smaller the force F2. Therefore, compared with the existing power adapter with the USB port portion 130 arranged on the lower surface 104, when a force is applied from the USB cable 20, the power adapter 10 of this embodiment achieves the effect that the power adapter 10 is less likely to fall off from the AC socket than the existing power adapter.

[0045] In addition, the power plug 120 of the power adapter 10 of this embodiment is fixed so as to be freely rotatable at any angle relative to the housing 100. Therefore, when a force F1 is applied through the USB cable 20, the housing 100 (reference Figure 3 ) is lifted by force F1 (reference Figure 4 (a)(b)), the power plug part 120 and the housing 100 rotate, thereby absorbing the rotational moment applied by the USB cable 20. In addition, the rotational moment generated by the center of gravity M of the housing 100 acts in a manner to offset the rotational moment applied by the USB cable 20. Thus, even when force is applied from the USB cable 20 , the power adapter 10 of the present invention can maintain the connection of the metal plug 121 by rotating the power plug portion 120 , thereby achieving the effect that the power adapter 10 is not easily detached from the AC socket.

[0046] (Center of gravity M) Figure 3 The position of the center of gravity M of the housing 100 of the power adapter 10 is shown. In the power adapter 10 of the first embodiment, the weight components such as the coil, the capacitor, and the power transistor are arranged near the power plug part 120, and further, by setting the step part 110 on the lower side 104, the center of gravity M is closer to the power plug part 120 side than the center of the housing 100. In this case, the center of gravity M of the housing 100 is preferably disposed on the upper side of 1 / 2 or more, and more preferably on the upper side of 1 / 3 or more, relative to the entire length in the longitudinal direction of the housing 100 . Therefore, in the power adapter 10 of the first embodiment, the distance between the fulcrum and the point of application of the torque applied by the center of gravity M is shortened, thereby preventing the power adapter 10 from falling off due to vibration, etc., and even if the power adapter 10 is installed in a place where there is vibration, such as in a train or a car, the power adapter 10 is not likely to fall off from the AC socket.

[0047] (Variant 1) Figure 5 Modification 1 of the power adapter 10 of the first embodiment is shown. Figure 5 (a) is a schematic diagram showing that the step portion 110 is provided on a portion of the lower surface 104 side of the front surface 101 when there is only one USB port portion 130. In this case, the risk of the user hooking the holding portion can be more reliably reduced, thereby preventing damage to the USB cable 20. Figure 5(b) is a schematic diagram showing that when there are four USB port parts 130, the stepped part 110 is provided in two layers. In this case, it is possible to easily insert and remove four USB cables 20 without interference with each other. Note that in Figure 5 (b), although an example is shown where the left - right positions of the upper - layer and lower - layer USB port parts 130 are the same, it is not limited to this, and the left - right positions of the USB port parts 130 in the upper layer and the lower layer may deviate. Figure 5 (c) is a schematic diagram showing that a columnar part having the same height as the front surface 101 is provided at the central part of the stepped part 110 in the left - right direction, and the USB port part 130 is arranged on the side surface 111 of the columnar part. In this case, the two USB cables 20 extend in opposite directions, so it is difficult for the USB cables 20 to interfere with each other, and the insertion and removal of the USB cables 20 become easy. Figure 5 (d) is the same as Figure 5 (a). The stepped part 110 is provided at a part of the lower surface 104 side of the front surface 101, and further, the USB port part 130 is arranged on the side surface 111 in the left - right direction of the stepped part 110. When the power adapter 10 is connected to an AC outlet located near the indoor floor, the USB cable 20 can extend horizontally, so it is very convenient.

[0048] (Modification Example 2) Figure 6 A modification example 2 of the power adapter 10 of the first embodiment is shown. In Figure 6 (a), the thickness of the housing 100 (the distance between the front surface 101 and the back surface 102) is thicker on the upper side where the power plug part 120 is provided, and thinner near the side surface 111 of the stepped part 110. In this case, since heavy components such as coils, capacitors, and power transistors can be arranged closer to the power plug part, the center of gravity M of the power adapter 10 can be closer to the power plug part 120. Thus, even when the power adapter 10 is set in a place with vibration such as on a train, the power adapter 10 is not easily detached from the AC outlet. In Figure 6 (b), the width of the housing 100 (the distance between the right surface 105 and the left surface 106) is wider on the upper side where the power plug part 120 is provided, and narrower near the side surface 111 of the stepped part 110. In this case, since heavy components such as coils, capacitors, and power transistors can be arranged closer to the power plug part 120, the center of gravity M of the power adapter 10 can be closer to the power plug part 120. It should be noted that the above Modification Example 1 and Modification Example 2 can be executed overlappingly. That is, by simultaneously increasing the thickness and width of the housing 100 on the upper surface 103 side where the power plug portion 120 is provided, the center of gravity M of the power adapter 10 can be further closer to the power plug portion 120.

[0049] (Usage example of the power adapter 10) Figure 7 It is a schematic explanatory diagram for explaining the usage state of the power adapter 10 of the first embodiment. In recent years, the installation of AC sockets for charging smartphones and the like has become increasingly widespread. For example, in the Tokaido Shinkansen N700S, AC sockets are provided on the armrests of all seats. However, in the case of the Shinkansen, due to space limitations, the AC sockets are configured at the front end of the armrest and are inclined obliquely downward. Figure 7 (a) shows a usage example when the AC socket of this armrest is connected to the power adapter 10 of this embodiment, Figure 7 (b) shows a usage example when the AC socket of this armrest is connected to an existing power adapter. In Figure 7 (b), the power adapter protrudes obliquely forward from the AC socket at the front end of the armrest, and the USB cable 20 extends from its front end. Therefore, when a passenger moves or the like, there is a risk that the power adapter or the USB cable 20 may touch the passenger's body, resulting in the power adapter falling off or the like. In addition, since the USB cable 20 extends from the front end of the power adapter, the distance between the mounting portion of the USB cable 20 and the power plug is long. When a force is applied to the USB cable 20, the rotational torque on the power plug becomes larger, and thus the power plug is likely to fall off from the AC socket. In addition, since the center of gravity position of the existing power adapter is at a position horizontally far from the AC socket, a relatively large rotational torque is likely to be generated due to the vibration of the train, resulting in the power plug being likely to fall off from the AC socket.

[0050] In contrast, when the AC socket at the front end of the armrest is connected to the power adapter 10 of this embodiment, the following effects are obtained. First, since the power plug portion 120 is fixed to be rotatable freely relative to the housing 100, as Figure 7 (a) shows, the housing 100 can be rotated so that the power adapter 10 and the USB cable 20 face downward, and thus it is easy to install even in a narrow space. Second, since the power plug portion 120 is fixed to be rotatable freely relative to the housing 100, when a force is applied to the USB cable 20, the force applied to the power plug portion 120 can be reduced by rotating the housing 100. Furthermore, since the USB port portion 130 is provided on the side surface 111 of the stepped portion 110 and the distance between the power plug portion 120 and the USB port portion 130 is short, when a force is applied to the USB cable 20, the rotational torque on the power plug portion 120 becomes smaller, so that the power plug portion 120 is not easily detached from the AC socket. In addition, since the holding portion of the USB cable 20 is housed in the stepped portion 110, the risk that a user (passenger) catches the holding portion can be reduced, thereby preventing damage to the USB cable 20. Moreover, the position of the center of gravity M of the power adapter 10 of the present embodiment is close to the power plug portion 120. In addition, as the power plug portion 120 rotates, the housing 100 becomes vertical, so that the position of the center of gravity M is in a position close to the AC socket in the horizontal direction. Thus, the generation of rotational torque can be suppressed, and therefore, even when the train vibrates, the power plug can be prevented from detaching from the AC socket. As described above, relative to Figure 7 the conventional power adapter shown in (b), Figure 7 the power adapter of the present embodiment shown in (a) does not become an obstacle when a passenger moves, and even when a force is applied to the USB cable 20, the effect that the power adapter is not easily detached from the AC socket can be achieved.

[0051] [Second Embodiment] Figure 8 FIG. is a schematic perspective view of the power adapter 10 of the second embodiment. In the power adapter 10 of the second embodiment, the stepped portion 110 is provided on the upper surface 103 side of the front surface 101 and is formed in a stepped shape by the side surface 111 and the front surface 1112. The side surface 111 is substantially orthogonal to the front surface 101, the front surface 112 is parallel to the front surface 101, and is closer to the front surface than the back surface. That is, the stepped portion 110 is provided near the power plug portion 120. The other structures are the same as those of the power adapter 10 of the first embodiment. In this case, when the distance between the USB port portion 130 and the power plug portion 120 is small and a rotational torque is applied from the USB cable 20 to the USB port portion 130, the magnitude of the rotational torque on the power plug portion 120 becomes smaller. Therefore, the power adapter 10 is not easily detached from the AC socket, etc., achieving the same effect as the first embodiment.

[0052] In the present invention, the power plug head 120 corresponds to the "power plug head", the USB port part 130 corresponds to the "USB port part", the socket part 140 corresponds to the "socket part", the housing 100 corresponds to the "housing", the front surface 101 corresponds to the "front surface", the back surface 102 corresponds to the "back surface", the upper surface 103 corresponds to the "upper surface", the lower surface 104 corresponds to the "lower surface", the right surface 105 corresponds to the "right surface", the left surface 106 corresponds to the "left surface", the power adapter 10 corresponds to the "power adapter", the stepped part 110 corresponds to the "stepped part", the side surface 111 corresponds to the "side surface", the front surface 112 corresponds to the "front surface", the plug base 122 corresponds to the "plug base", the connection surface 123 corresponds to the "connection surface", and the storage part 124 corresponds to the "storage part".

[0053] A preferred embodiment of the present invention is as described above, but the present invention is not limited thereto. It should be understood that various other embodiments can be made as long as the spirit and scope of the present invention are not departed from. Additionally, although the functions and effects obtained due to the structure of the present invention are described in this embodiment, these functions and effects are only examples and do not limit the present invention accordingly.

Claims

1. A power adapter, which is a power adapter having a power plug portion that can be inserted into an AC socket, a USB port portion that can supply power to a USB device, and a housing having a substantially rectangular parallelepiped shape with a front surface, a back surface, an upper surface, a lower surface, a right surface, and a left surface, characterized in that, the power plug portion is provided on the upper side of the back surface of the housing and is fixed so as to be rotatable freely by any angle relative to the housing, the housing is provided with a stepped portion on the upper side or the lower side of the front surface, the USB port portion is provided on a side surface of the stepped portion that is substantially orthogonal to the front surface.

2. The power adapter according to claim 1, characterized in that, the stepped portion is provided on the lower side of the front surface and forms a stepped shape by a side surface and a front surface, the side surface is substantially orthogonal to the front surface, the front surface is parallel to the front surface, and is closer to the front surface than the back surface.

3. The power adapter according to claim 1, characterized in that, the stepped portion is provided on the upper side of the front surface and forms a stepped shape by a side surface and a front surface, the side surface is substantially orthogonal to the front surface, the front surface is parallel to the front surface, and is closer to the front surface than the back surface.

4. The power adapter according to any one of claims 1 to 3, characterized in that, the power adapter further includes a socket portion that can supply AC power to other devices, the socket portion is provided on the front surface of the housing.

5. The power adapter according to any one of claims 1 to 3, characterized in that, the center of gravity of the power adapter is configured to be on a side closer to the power plug portion than the center of the housing.

6. The power adapter according to any one of claims 1 to 3, characterized in that, the length (N) of the stepped portion in the long side direction of the housing is 1.5 cm or more.

7. The power adapter according to any one of claims 1 to 3, characterized in that, the housing includes a storage portion that can store the power plug portion, the power plug portion is supported by an axis parallel to the edge intersecting the upper surface and the back surface and is fixed so as to be rotatable freely by any angle relative to the housing, the range of the rotatable angle of the power plug portion is greater than 90° and not greater than 180°.

8. The power adapter according to claim 7, characterized in that, the cross sections of the corner portions on the right surface and the left surface of the housing that support the power plug portion are arc-shaped, the power plug portion has a metal plug and a plug base that supports the metal plug, the center of the arc forming the arc-shaped shape coincides with the rotation center of the plug base, and the radius (r) of the arc forming the arc-shaped shape and the perpendicular distance (L) from the rotation center of the plug base to the connection surface connected to the opposing socket are the same in length.

Images