Power supply adapter

Abstract

To provide a power supply adapter which is hardly dropped from an AC outlet, in which a USB cable is hardly damaged, and which can be easily installed even in a narrow space.SOLUTION: A power supply adapter 10 comprises: a power supply plug part 120 that can be inserted into an AC outlet; a USB port part 130 that can supply power to a USB device; an outlet part 140 that can perform AC power supply to another device; and an approximately parallelepiped housing 100 that includes 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 supply plug part 120 is provided on the upper surface 103 side of the back surface 102 of the housing 100. The housing 100 is provided with a step part 110 on the lower surface side 104 or the upper surface 103 side of the front surface 101. The USB port part 130 is provided on a side surface 111 that is approximately orthogonal to the front surface 101 of the step part 110.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power adapter capable of supplying power to a USB device.

Background Art

[0002] As a power adapter capable of supplying power to a USB device, the following 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 be used for electronic devices that require USB power supply even in an environment without a power outlet.

[0003] In the power supply unit described in Patent Document 1, in the lower case of the power supply unit body, a first AC auxiliary power outlet and a second AC auxiliary power outlet electrically connected to the power plug are provided at a portion adjacent to the power plug. A power plug to be inserted into an AC power outlet is provided at one end side of the lower case. A USB port serving as a power supply port for an electronic device such as a speaker for a personal computer is provided at the other end side of the lower case. Power output from the power plug or power output from the battery is selectively output to the USB port via an electric circuit 15.

[0004] Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2014-75349) proposes a partially rotatable power outlet that can expand the usage range of a USB insertion port by providing a structure of a rotatable USB outlet.

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

[0006] Patent Document 3 (Japanese Patent Application Laid-Open No. 2011-138738) proposes a partially rotatable power outlet capable of expanding the usage range of USB insertion ports by providing a structure of a rotatable USB outlet.

[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 pivotally provided to the main body by the rotating shaft member and rotating about the rotating shaft member as an axis, and at least one USB insertion port provided on the rotating body and rotating in conjunction with the rotating body.

[0008] Patent Document 4 (Utility Model Registration No. 3141303) proposes a flat tap with a USB power supply function having a USB insertion port.

[0009] The flat tap described in Patent Document 4 includes a flat tap casing 1 formed by joining upper and lower casings, a recess 1a formed in the flat tap casing 1, a plug blade holder 2 rotatably mounted in the recess 1a, a pair of plug blade fittings 3 protruding from the plug blade holder 2, a receiving blade fitting 4 electrically connected to the pair of plug blade fittings 3, and a receiving blade cover 5 provided with a plug insertion port for inserting a plug into the receiving blade portions 4a of the receiving blade fitting 4 provided on both side surfaces of the flat tap casing 1 orthogonal to the recess 1a. The USB board 6 electrically connected to the receiving blade fitting 4 is installed inside the flat tap casing 1, and the USB insertion port 6a is provided on the side surface of the flat tap casing 1 parallel to the recess 1a.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0011] Generally, a power adapter is connected to an AC outlet provided 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 the purpose of communicating information, and the bus power that can be supplied via USB has been limited to low power. Therefore, the devices that can be powered via USB are limited, and generally, a dedicated power adapter is required for each device. For example, for a notebook computer, a dedicated power adapter is bundled or sold for each manufacturer, and the user has to connect the power adapter to the AC outlet for each device. However, in recent years, standards such as USB Power-Delivery (PD) have been devised, making it possible to supply power to various devices through a USB connection. In addition to mobile phones, it is becoming possible to supply power through USB to devices that require large power, such as tablets, notebook computer bodies, displays, and projectors. In this case, the user no longer needs to carry around dedicated power adapters for each device as in the past, and can use a single USB power adapter to use various devices in various locations. In particular, conventional USB power adapters have mainly been used for charging the batteries of small devices such as mobile phones, but in the future, they will be used more frequently for powering devices such as laptops, not just for charging. Then, in the past, there were many scenarios such as using a power adapter plugged into an AC outlet near the floor to charge a mobile phone placed on the bed or beside the pillow. However, there will be more scenarios such as powering a laptop or projector on a table, and it will be more common to operate USB devices at a location slightly away from the power adapter. And since these USB devices are not stationary devices, when the USB device is moved slightly, the USB cable moves, which easily causes the problem that the power adapter is likely to fall out of the AC outlet.

[0012] In recent years, services providing AC power in various scenarios such as cafes or train seats are increasing. Due to space constraints and other reasons, AC outlets are not always provided on vertical walls. For example, AC outlets may be provided on walls inclined relative to the vertical, such as the back of the tabletop or the tip of the armrest of the seat. In this case, the power adapter will be supported in the air by the power plug, and the problem that the power adapter is likely to fall out of the AC outlet becomes even more likely to occur. In particular, when a power adapter is installed in a place with vibration such as in a train, the problem that the power adapter is likely to fall out of the AC outlet becomes prominent.

[0013] In addition, since the USB cable is provided with a holding portion between the connection port and the cable, when the USB cable is connected to the power adapter, the holding portion protrudes from the power adapter. Therefore, there is a problem that the user may catch this holding portion and damage the USB cable. Furthermore, 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 surroundings such as the floor surface.

[0014] The power supply unit of Patent Document 1 has a plug portion (power plug) that is rotatable with respect to the case, and the case is provided with a power plug insertion port (outlet portion) and a USB port. However, the USB port is provided on the surface of the rectangular parallelepiped case, and since the plug portion and the USB port are respectively arranged on the most distant surfaces of the case, when the USB cable is slightly moved, the case shakes and the plug portion is likely to fall off from the AC outlet. Also, since the holding portion of the USB cable protrudes from the case, it is easy for the user to catch it, and there is a problem that it is difficult to arrange it in a narrow place. Also, although the power plug insertion port is rotatable with respect to the case, it is assumed that the case is installed along a vertical wall surface. When installed in an AC outlet provided on a non-vertical surface such as an inclined surface, there is a problem that it is likely to fall off.

[0015] The power outlets of Patent Documents 2 and 3 are configured such that the USB insertion port (USB port portion) is rotatable with respect to the main body. However, in Example 1 and the like, the relationship between the plug and the USB insertion port in the main body is not described. In Example 4 and the like, the USB insertion port is arranged such that it is diagonal to the cross-section of the main body with respect to the plug. Therefore, when the USB cable is slightly moved, the case shakes and the plug portion is likely to fall off from the AC outlet. Also, since the holding portion of the USB cable protrudes from the case, it is easy for the user to catch it, and there is a problem that it is difficult to arrange it in a narrow place. In addition, although the plug is rotatable with respect to the main body (Example 4), it is assumed that the main body is installed along a vertical wall surface. When installed in an AC outlet provided on a non-vertical surface such as an inclined surface, there is a problem that it is likely to fall off.

[0016] The flat plug with a USB power supply function in Patent Document 4 includes a rotatable plug blade fitting (power plug portion) and a USB insertion port in a flat plug casing. However, the USB insertion port is provided on the surface of the rectangular parallelepiped flat plug casing, and since the plug blade fitting and the USB insertion port are respectively arranged on the most distant surfaces of the flat plug casing, when the USB cable is slightly moved, the case shakes and the plug blade fitting is likely to fall off from the AC outlet. Also, since the holding portion of the USB cable protrudes from the case, it is easy for the user to catch it, and there is a problem that it is difficult to arrange it in a narrow space. In addition, although the plug blade fitting is rotatable with respect to the flat plug casing, when installed in an AC outlet provided on a non-vertical surface such as an inclined surface, there is a problem that it is likely to fall off.

[0017] Therefore, an object of the present invention is to provide a power adapter that is difficult to fall off from an AC outlet. Another object of the present invention is to provide a power adapter in which the USB cable is difficult to be damaged and is easy to install even in a narrow space.

Means for Solving the Problems

[0018] (1) A power adapter according to one aspect is a power adapter including a power plug portion that can be inserted into an AC outlet, a USB port portion that can supply power to a USB device, and a substantially rectangular parallelepiped housing having a front surface, a back surface, an upper surface, a lower surface, a right surface, and a left surface, wherein the power plug portion is provided on the upper surface side of the back surface of the housing and is rotatably fixed to the housing at an arbitrary angle, the housing is provided with a step portion on the upper surface side or the lower surface side of the front surface, and the USB port portion is provided on a side surface substantially orthogonal to the front surface of the step portion.

[0019] In conventional power adapters, since the USB port section was provided on the surface of the housing (mainly the lower surface of a rectangular parallelepiped), when a USB device was moved, the elastic USB cable would pull on the housing of the power adapter. Then, a rotational moment would be generated around the power plug section inserted into an AC outlet on a wall or the like, and the USB port section would act as the force point. Thus, there was a problem that even with the influence of a slight force from the USB cable, the power adapter was likely to fall out of the AC outlet. In one aspect, the power adapter has a power plug section provided on the upper surface side of the back of the housing, and a USB port section provided on the side surface (a surface substantially orthogonal to the front) of a stepped portion provided on the lower surface side or the upper surface side of the front of the housing. And since the power plug section is inserted into an AC outlet on a wall or the like to hold the housing, compared with the case where the USB port section is provided on the lower surface of the housing, the distance between the power plug section and the USB port section becomes shorter, and the influence of the rotational moment received by the housing from the USB cable can be suppressed. Therefore, even when the USB device is moved, the power plug is less likely to come out of the AC outlet, so it is possible to prevent the power adapter from falling out of the AC outlet. Also, since it is less susceptible to the influence of the rotational moment received from the USB cable and the load on the power plug section is small, when installed in an AC outlet provided on a non-vertical surface such as an inclined surface, or when installed in a place where vibration is likely such as inside a train, it is possible to prevent the power adapter from falling out of the AC outlet.

[0020] Moreover, since the power plug section is rotatably fixed to the housing at an arbitrary angle, even when the AC outlet is provided on a forward-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 a vertical position. In this case, since the center of gravity of the power adapter and the power plug portion supported by the AC outlet are on the vertical line, and the center of gravity of the power adapter does not apply a rotational moment to the power plug portion, the power adapter can be made less likely to fall off from the AC outlet. Also, since the power plug portion is rotatably fixed to the housing at an arbitrary angle, for example, even when a rotational moment is applied to the USB port portion by a USB cable, the housing can rotate while the power plug portion remains inserted into the wall-mounted AC outlet, and as a result, the power adapter does not fall off from the AC outlet.

[0021] Further, since the USB port portion is provided at the stepped portion of the housing, the holding portion of the USB cable is housed in the stepped portion. This can reduce the risk of the user hooking the holding portion and prevent the USB cable from being damaged. Furthermore, since the holding portion of the USB cable is housed in the stepped portion, the holding portion is less likely to interfere with the surroundings such as the floor surface, and the power adapter can be made easy to install even in a narrow space.

[0022] In the present invention, for ease of understanding, terms such as the front as one surface of the housing of the power adapter, the back as the other surface facing the front, the right side and the left side as the surfaces adjacent to and facing the front, and the upper surface and the lower surface are used. However, the front does not necessarily have to be on the indoor space side, and the upper surface does not necessarily have to be on the vertically upward side.

[0023] (2) The power adapter according to the second invention is a power adapter according to an aspect of the invention, and the stepped portion may be provided on the lower surface side of the front and may be configured in a stepped shape by a side surface substantially orthogonal to the front and a front surface parallel to the front and closer to the back.

[0024] The power adapter according to the second invention corresponds to the power adapter of the first embodiment. As a result, since the stepped portion is provided at a diagonal position away from the power plug portion, it becomes easier to arrange the internal components (such as a transformer) of the power adapter on the power plug portion side, and it becomes easier to design the position of the center of gravity of the power adapter main body on the power plug portion side. In addition to the rotational moment applied to the power adapter by the USB cable described above, it is also necessary to consider the moment applied by the weight of the power adapter itself. In particular, in a space where vibration is applied, such as inside a train, by designing the position of the center of gravity of the power adapter main body to be on the power plug portion side, the load applied to the power plug portion can be reduced, and the power adapter can be prevented from falling off the AC outlet.

[0025] (3) The power adapter according to the third invention is a power adapter according to one aspect, and the stepped portion may be provided on the upper surface side of the front surface and may be configured in a stepped shape by a side surface substantially orthogonal to the front surface and a front surface parallel to the front surface and closer to the back surface.

[0026] The power adapter according to the second invention corresponds to the power adapter of the second embodiment. In this case, since the power plug portion is provided on the upper surface side of the back surface of the housing and the USB port portion is also provided on the upper surface side of the front surface of the housing, the distance between the power plug portion and the USB port portion can be minimized. Therefore, the magnitude of the rotational moment applied from the USB cable can be minimized, and the power adapter can be prevented from falling off the AC outlet.

[0027] (4) The power adapter according to the fourth invention is a power adapter according to any one of the first aspect to the third invention, and further includes a socket portion capable of AC power supply to other devices, and the socket portion may be provided on the front surface of the housing.

[0028] Even when the power adapter occupies an AC outlet due to the presence of an outlet part, it can supply power to and operate other AC devices. Therefore, even in a situation where the number of AC outlets is insufficient, such as in a train, power can be supplied to multiple devices simultaneously. In particular, since the outlet part is provided on the front of the housing and the USB port part is provided on the stepped side surface, the power cable inserted into the outlet part and the USB cable inserted into the USB port part extend in directions perpendicular to each other. Therefore, it is less likely for the power cable and the USB cable to interfere with each other, and it becomes easier to insert and remove the power cable. Also, even if a USB device is moved and a rotational moment is applied to the housing from the USB cable, since the rotational moment is suppressed by the weight of the power cable connected to the power plug part and acts on the housing, it is possible to prevent the power adapter from falling out of the AC outlet.

[0029] (5) The power adapter according to the fifth invention is a power adapter according to any one of the fourth inventions in one aspect, and the center of gravity of the power adapter may be configured to be on the side of the power plug part rather than the center of the housing.

[0030] When the power plug part is inserted into an AC outlet to hold the housing, the rotational moment applied by the weight of the power adapter itself acts around the power plug part. Therefore, when vibration or the like is applied to the power adapter, there is a problem that it is likely to fall out of the AC outlet. Since the center of gravity of the power adapter according to the fifth invention is on the side of the power plug part rather than the center of the housing, the distance between the fulcrum and the point of force of the moment applied by the center of gravity becomes shorter, and it is possible to prevent falling off due to vibration or the like. Therefore, it is possible to provide a power adapter that is less likely to fall out of an AC outlet even when installed in a vibrating place such as in a train or a car.

[0031] (6) The power adapter according to the sixth invention is a power adapter according to any one of the fifth inventions in one aspect, and the length N in the longitudinal direction of the housing of the stepped portion may be 1.5 cm or more.

[0032] Thereby, since the holding portion of the USB cable is housed in the stepped portion, the risk that the user hooks the holding portion can be reduced, and the USB cable can be prevented from being damaged. In addition, it is possible to provide a power adapter in which the holding portion is less likely to interfere with the surroundings such as the floor surface and is easy to install even in a narrow space.

[0033] (7) The power adapter according to the seventh invention is a power adapter according to any one of the sixth inventions in one aspect, wherein the housing includes a storage portion capable of storing the power plug portion, and the power plug portion is pivotally supported parallel to the side where the upper surface and the back surface intersect, and is fixed to the housing so as to be rotatable at an arbitrary angle. The range of the angle at which the power plug portion can rotate may be more than 90° and 180° or less.

[0034] By providing the housing with a storage portion capable of storing the power plug portion, the power plug portion can be stored in the storage portion when the power adapter is carried, which is convenient. In addition, by setting the angle of the power plug portion at the time of storage to 0° and setting the range of the rotatable angle to more than 90° and 180° or less, the power adapter can be fixed parallel to the wall surface even when the wall surface where the AC outlet is installed is a vertical surface.

[0035] (8) The power adapter according to the eighth invention is a power adapter according to any one of the seventh inventions in one aspect, wherein the corners of the right and left sides of the housing that pivotally support the power plug portion have an R-shaped cross section, and the power plug portion has a metal plug and a plug base that supports the metal plug. The center of the arc forming the R shape coincides with the rotation center of the plug base, and the radius r of the arc forming the R shape may be the same length as the perpendicular distance L from the rotation center of the plug base to the connection surface with the opposing outlet.

[0036] As a result, since the radius r of the arc forming the R shape of the housing is the same as the perpendicular distance L from the rotation center of the plug base to the connection surface, even when the power plug portion is rotated, the connection surface of the plug base always coincides with the tangent of the R shape of the housing. Therefore, while the wall surface provided with the AC outlet and the connection surface of the plug base of the power adapter are in close contact, a corner portion with the power plug portion contacts the wall surface of the AC outlet, making it easy to fully insert the metal plug of the power plug portion into the AC outlet. Also, even when a rotational moment is applied to the USB port portion by the USB cable, the housing can rotate while the corner portion of the housing remains in contact with the wall surface, preventing the power adapter from falling off. Further, even when a rotational moment in the left - right direction is applied to the USB port portion, since the corner portions (R shapes) of the power plug portions on the right and left sides are in contact with the wall surface of the AC outlet, the power adapter is less likely to fall off from the AC outlet compared to the case where only the power plug portion is in contact with the wall surface.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0038] [First Embodiment] The power adapter 10 of the first embodiment is portable by the user, and by inserting the power plug portion 120 into a household AC outlet (alternating current power supply), a direct current power supply can be supplied from the USB port portion 130 to supply power to a USB device. As shown in FIGS. 1 and 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 AC power to other devices, and a substantially rectangular parallelepiped housing 100 having a front surface 101, a rear 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 that is substantially orthogonal to the front surface 101 of the stepped portion 110.

[0039] The power plug portion 120 includes a metal plug 121 made of metal and electrically connected to an AC outlet, and a plug base portion 122 that supports the metal plug 121 and is rotatably fixed to the housing 100. The plug base portion 122 of the power plug portion 120 is pivotally supported in the left - right direction of the housing 100 and is rotatably fixed at 180°. When connecting the power adapter 10 to an AC outlet provided on the wall surface W, as shown in FIG. 2, the power plug portion 120 is opened at an angle of 180° so as to be perpendicular to the rear surface 102 for use. On the other hand, as shown in FIG. 3, when connecting the power adapter 10 to an AC outlet provided on an inclined surface, the power plug portion 120 is opened at an appropriate angle according to the inclined surface for use. Also, when the power adapter 10 is not in use, the power plug portion 120 can be easily stored or carried by being stored in the storage portion 124 (setting the angle to 0°).

[0040] (Step portion 110) The step portion 110 is provided on the lower surface 104 side of the front surface 101 of the housing 100, and is formed in a stepped shape by a side surface 111 substantially orthogonal to the front surface 101 and a front surface 112 parallel to the front surface 101 and closer to the back surface 102. A USB port portion 130 is provided on the side surface 111, and power can be supplied to a USB device by connecting a USB cable 20 to the USB port portion 130. As shown in FIG. 3, the length N in the longitudinal direction of the power adapter 10 on the front surface 112 of the step portion 110 is preferably 1.0 cm or more, more preferably 1.5 cm or more, and even more preferably 1.8 cm or more. Also, the length N is preferably 4.0 cm or less, and more preferably 3.0 cm or less. By setting it to be equal to or greater than the above lower limit value, the holding portion of the USB cable 20 is housed in the step portion 110, so that the risk of the user hooking the holding portion can be reduced, and the USB cable 20 can be prevented from being damaged. Also, it is possible to make the power adapter 10 such that the holding portion is less likely to interfere with the surroundings such as the floor surface and is easy to install even in a narrow space. Also, by setting it to be equal to or less than the above upper limit value, it is possible to prevent the size of the entire housing 100 from becoming large. Also, by providing the USB port portion 130 on the side surface 111 of the step portion 110 and providing the outlet portion 140 on the front surface 101 of the housing 100, the power cable inserted into the outlet portion 140 and the USB cable 20 inserted into the USB port portion 130 extend in directions orthogonal to each other. Therefore, it becomes difficult for the power cable and the USB cable 20 to interfere with each other, and it becomes easy to insert and remove the power cable.

[0041] In addition, in the present embodiment, an example is shown in which the USB port portion 130 is provided only on the side surface 111 of the step portion 110 and the outlet portion 140 is provided only on the front surface 101 of the housing 100. However, the present invention is not limited to this, and the USB port portion 130 and / or the outlet portion 140 may be appropriately added to any surface such as the right surface 105, the left surface 106, and the front surface 101 of the housing 100.

[0042] (Power plug unit 120) FIG. 3 is a schematic explanatory view for explaining the R shape of the power plug unit 120 and the housing 100 of the power adapter 10. Referring to FIGS. 1 and 3, the housing 100 includes a storage portion 124 for storing the power plug unit 120, and the power plug unit 120 includes a plug base 122 and a metal plug 121. The plug base 122 is pivotally supported parallel to the intersecting side of the upper surface 103 and the rear surface 102 of the housing 100. Also, the corners of the right surface 105 and the left surface 106 of the housing 100 that pivotally support the power plug unit 120 have a cross-sectional shape that is R-shaped, the center of the arc forming the R shape coincides with the pivot center of the plug base 122, and the radius r of the arc forming the R shape is the same length as the perpendicular distance L from the pivot center of the plug base 122 to the connection surface 123 that contacts the opposing outlet. With the above configuration, even when the power plug unit 120 is rotated, the connection surface 123 of the plug base 122 always coincides with the tangent line of the R shape of the housing 100, and the wall surface W provided with the AC outlet always contacts the connection surface 123 of the plug base 122 of the power adapter 10 and the tangent line of the R shape of the housing 100. For this reason, it becomes easy to sufficiently insert the metal plug 121 of the power plug unit 120 into the AC outlet. Also, even when a rotational moment is applied in one direction (the left-right direction in front view) by the USB cable 20, the R shape of the housing 100 contacts the wall surface W, thereby preventing the power adapter 10 from falling off.

[0043] FIG. 4 is a schematic explanatory view for explaining the movement of the power adapter 10 when a force is applied from the USB cable 20 to the power adapter 10 of the first embodiment. In FIG. 4, the power adapter 10 is inserted into an AC outlet provided on a wall surface W inclined with respect to the vertical direction. First, assume that a force F1 is applied to the USB port portion 130 by the USB cable 20 in a state where neither the upper surface 103 nor the rear surface 102 of the power adapter 10 in Fig. 4(a) is in contact with the wall surface W. In this case, since the radius r of the arc forming the R shape and the perpendicular distance L from the rotation center of the plug base 122 to the connection surface 123 in contact with the opposing socket are of the same length, the power adapter 10 rotates about the rotation center of the plug base 122 due to the rotational moment of the force F1, resulting in the state shown in Fig. 4(b). When the force F1 is further applied to the USB port portion 130 in the state of Fig. 4(b), a rotational moment due to the force F1 is applied with respect to the fulcrum in the figure, and a force F2 is applied to the metal plug 121 of the power plug portion 120. When this force F2 is greater than the frictional force of the metal plug 121, the power adapter 10 will come out of the wall surface W. This force F2 is given by F2 = F1 × a ÷ b, where a is the distance between the fulcrum and the USB port portion 130, and b is the distance between the fulcrum and the metal plug 121. Since the fulcrum is 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, when compared with a conventional power adapter in which the USB port portion 130 is arranged on the lower surface 104, when a force is applied from the USB cable 20, the power adapter 10 of the present embodiment has the effect that the power adapter 10 is less likely to come out of the AC socket compared to the conventional power adapter.

[0044] Also, in the power adapter 10 of the present embodiment, the power plug portion 120 is fixed to the housing 100 so as to be rotatable at an arbitrary angle. Therefore, when the force F1 is applied by the USB cable 20, the housing 100 that was vertical (see Fig. 3) is lifted by the force F1 (see Figs. 4(a) and 4(b)), and the power plug portion 120 and the housing 100 rotate to absorb the rotational moment applied by the USB cable 20. And the rotational moment due to the center of gravity M of the housing 100 acts to cancel out the rotational moment applied by the USB cable 20. Thus, even when force is applied from the USB cable 20, in the power adapter 10 of the present invention, the connection of the metal plug 121 is maintained by the rotation of the power plug portion 120, so that the power adapter 10 is less likely to be disconnected from the AC outlet.

[0045] (Center of gravity M) FIG. 3 shows the position M of the center of gravity of the housing 100 of the power adapter 10. In the power adapter 10 of the first embodiment, heavy components such as a coil, a capacitor, and a power transistor are arranged near the power plug portion 120, and further, by providing the step portion 110 on the lower surface 104 side, the center of gravity M is made to be on the power plug portion 120 side from the center of the housing 100. In this case, the center of gravity M of the housing 100 is preferably provided on the upper surface side from 1 / 2 with respect to the total length in the longitudinal direction of the housing 100, and more preferably provided on the upper surface side from 1 / 3. Thereby, in the power adapter 10 of the first embodiment, the distance between the fulcrum and the force point of the moment given by the center of gravity M is shortened, and it is possible to prevent dropping due to vibration or the like. Even when installed in a vibrating place such as inside a train or a car, the power adapter 10 can be made less likely to drop out from the AC outlet.

[0046] (Modification 1) FIG. 5 shows Modification 1 of the power adapter 10 of the first embodiment. FIG. 5(a) shows a case where the USB port portion 130 has one, and the step portion 110 is provided on a part of the lower surface 104 side of the front surface 101. In this case, the risk that the user catches the holding portion more reliably can be reduced, and the USB cable 20 can be prevented from being damaged. FIG. 5(b) shows a case where the USB port portion 130 has four, and the step portion 110 has two steps. In this case, the four USB cables 20 can be easily inserted and removed without interfering with each other. In addition, in FIG. 5(b), an example where the left - right positions of the upper - stage and lower - stage USB port portions 130 are the same is shown, but it is not limited to this, and the left - right positions of the USB port portions 130 may be shifted between the upper stage and the lower stage. Fig. 5(c) shows a structure in which a columnar part having the same height as the front surface 101 is provided at the center in the left - right direction of the step part 110, 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 to each other, making it difficult for the USB cables 20 to interfere with each other and facilitating the insertion and removal of the USB cables 20. Fig. 5(d) is the same as Fig. 5(a) in that the step part 110 is provided in a part on 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 step part 110. When the power adapter 10 is connected to an AC outlet in a place close to the indoor floor, it is convenient because the USB cable 20 can extend horizontally.

[0047] (Modification 2) Fig. 6 shows Modification 2 of the power adapter 10 of the first embodiment. In Fig. 6(a), the thickness of the housing 100 (the distance between the front surface 101 and the rear surface 102) is thick on the upper surface side where the power plug part 120 is arranged, and thin near the side surface 111 of the step 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 brought closer to the power plug part 120. Even when the power adapter 10 is installed in a vibrating place such as in a train, the power adapter 10 is less likely to fall off from the AC outlet. In Fig. 6(b), the width of the housing 100 (the distance between the right surface 105 and the left surface 106) is wide on the upper surface side where the power plug part 120 is arranged, and narrow near the side surface 111 of the step part 110. Also 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 brought closer to the power plug part 120. Note that Modification 1 and Modification 2 above may be carried out in combination. That is, by increasing the thickness and width of the housing 100 on the upper surface 103 side where the power plug part 120 is arranged, the center of gravity M of the power adapter 10 can be further brought closer to the power plug part 120.

[0048] (Usage example of the power adapter 10) FIG. 7 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 outlets for charging smartphones and the like has spread. For example, in the Tokaido Shinkansen N700S, AC outlets are installed at the armrests of all seats. However, in the case of the Shinkansen, due to locational constraints, the AC outlet is arranged at the tip of the armrest and is inclined obliquely downward. FIG. 7(a) shows a usage example when the power adapter 10 of this embodiment is connected to the AC outlet at the tip of the armrest, and FIG. 7(b) shows a usage example when a conventional power adapter is connected. In FIG. 7(b), the power adapter protrudes obliquely forward from the AC outlet at the tip of the armrest, and the USB cable 20 extends from the tip thereof. Therefore, when a passenger moves, there is a risk that the power adapter or the USB cable 20 may touch the passenger's body and the power adapter may fall off. Also, since the USB cable 20 extends from the tip of the power adapter, the distance between the attachment portion of the USB cable 20 and the power plug is long. When force is applied to the USB cable 20, the rotational moment with respect to the power plug becomes large, and the power plug is likely to fall off from the AC outlet. Further, since the position of the center of gravity of the conventional power adapter is at a position horizontally separated from the AC outlet, a large rotational moment is likely to be generated due to the vibration of the train, and the power plug is likely to fall off from the AC outlet.

[0049] On the other hand, when the power adapter 10 of this embodiment is connected to the AC outlet at the tip of the armrest, the following effects are obtained. First, since the power plug portion 120 is rotatably fixed to the housing 100, as shown in FIG. 7(a), the housing 100 can be rotated to direct the power adapter 10 and the USB cable 20 downward, so that it is easy to install even in a narrow space. Next, since the power plug portion 120 is rotatably fixed 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 the rotation of 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, the rotational moment applied to the power plug portion 120 when a force is applied to the USB cable 20 becomes smaller, and the power plug portion 120 is less likely to fall off from the AC outlet. Also, 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, and the USB cable 20 can be prevented from being damaged. And, in the power adapter 10 of the present embodiment, the position of the center of gravity M is close to the power plug portion 120, and since the power plug portion 120 rotates and the housing 100 becomes vertical, the position of the center of gravity M is close to the AC outlet in the horizontal direction. Thereby, the generation of the rotational moment can be suppressed, so that the power plug can be prevented from falling off from the AC outlet even when the train vibrates. As described above, the power adapter 10 of the present embodiment shown in Fig. 7(a) has the effect of not getting in the way when the passenger moves and being less likely to fall off from the AC outlet even when a force is applied to the USB cable 20 as compared with the conventional power adapter shown in Fig. 7(b).

[0050] [Second Embodiment] Fig. 8 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 configured in a stepped shape by the side surface 111 substantially orthogonal to the front surface 101 and the front surface 112 parallel to the front surface 101 and closer to the rear surface 102. That is, the stepped portion 110 is provided in the vicinity of the power plug portion 120. Other configurations are the same as those of the power adapter 10 of the first embodiment. In this case, since the distance between the USB port portion 130 and the power plug portion 120 is small and the rotational moment applied to the USB port portion 130 from the USB cable 20 causes a small rotational moment with respect to the power plug portion 120, the power adapter 10 is less likely to fall off from the AC outlet, and thus the same effects as those of the first embodiment are achieved.

[0051] In the present invention, the power plug portion 120 corresponds to the 'power plug portion', the USB port portion 130 corresponds to the 'USB port portion', the outlet portion 140 corresponds to the 'outlet portion', 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 portion 110 corresponds to the'stepped portion', the side surface 111 corresponds to the'side surface', the front surface 112 corresponds to the 'front surface', the metal plug 121 corresponds to the'metal plug', the plug base 122 corresponds to the 'plug base', the connection surface 123 corresponds to the 'connection surface', and the storage portion 124 corresponds to the'storage portion'.

[0052] Although a preferred embodiment of the present invention is as described above, the present invention is not limited thereto. It will be understood that various embodiments without departing from the spirit and scope of the present invention may be made. Further, in the present embodiment, the actions and effects according to the configuration of the present invention are described, but these actions and effects are merely examples and do not limit the present invention.

Explanation of Reference Numerals

[0053] 10 Power adapter 100 Housing 101 Front surface 102 Back surface 103 Upper surface 104 Lower surface 105 Right surface 106 Left surface 110 Stepped portion 111 Side surface 112 Front surface 120 Power plug part 121 Metal plug 122 Plug base 123 Connection surface 124 Storage part 130 USB port part 140 Outlet part M Center of gravity

Claims

1. A power adapter comprising a power plug portion that can be inserted into an AC outlet, a USB port portion that can supply power to a USB device, and a substantially rectangular parallelepiped housing having a front, a back, a top, a bottom, a right side, and a left side, wherein the power plug portion is provided on the upper surface side of the back surface of the housing and is rotatably fixed to the housing at an arbitrary angle, the housing is provided with a stepped portion on the upper surface side or the lower surface side of the front surface, the USB port portion is provided on a side surface substantially orthogonal to the front surface of the stepped portion, the power adapter.

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

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

4. further comprising an outlet portion capable of supplying AC power to other devices, the outlet portion is provided on the front surface of the housing, the power adapter according to any one of claims 1 to 3.

5. The power adapter according to any one of claims 1 to 3, wherein the center of gravity of the power adapter is configured to be on the side of the power plug portion rather than the center of the housing.

6. The power adapter according to any one of claims 1 to 3, wherein the length N in the longitudinal direction of the housing of the stepped portion is 1.5 cm or more.

7. the housing includes a storage portion capable of storing the power plug portion, the power plug portion is pivotally supported parallel to the side where the upper surface and the back surface intersect, and is rotatably fixed to the housing at an arbitrary angle, the range of the angle at which the power plug portion can rotate is more than 90° and 180° or less, the power adapter according to any one of claims 1 to 3.

8. the corners of the right side and the left side of the housing that pivotally support the power plug portion have an R-shaped cross section, the power plug portion has a metal plug and a plug base that supports the metal plug, the center of the arc forming the R shape coincides with the rotation center of the plug base, and the radius r of the arc forming the R shape is the same length as the perpendicular distance L from the rotation center of the plug base to the connection surface of the opposing outlet, the power adapter according to claim 7.

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