1. Field of the Invention
The present invention relates to an electric device having a charging function, and particularly to an electric device having a function of charging a battery of a target device.
2. Description of the Background Art
As a kind of electric devices of a rechargeable type, there has been a mobile work robot having functions of automatic moving and working. The mobile work robot has a rechargeable battery, which can be charged by a charging unit independent of the mobile work robot.
The charging unit is connected to a commercial power supply. When the mobile work robot is connected to the charging unit, a power is supplied from the commercial power supply to the mobile work robot to charge the battery. A cleaner employing the above charging method is disclosed, e.g., in Japanese Patent Laying-Open No. 2003-142164. The charging method disclosed in the above reference can charge a battery in a body of the cleaner by electrically or magnetically connecting a charging terminal of the cleaner body to a charging terminal of a charging base.
This reference has disclosed magnetic charging and thus the charging in a non-contact manner. Therefore, the charging base provides a magnetic flux energy, which is caused by an electromagnetic field produced during the charging operation, to the cleaner body, of which charging terminal is spaced by a predetermined distance from that of the charging base. When a foreign material enters a space between these charging terminals during the charging operation, or when another magnetic interference occurs therein, the magnetic field for the charging does not normally occurs so that the charging is impeded. If the foreign material in the space is metal, the metal causes a problem of heating. However, the above reference has neither disclosed nor suggested countermeasures against such problems.
For overcoming the above problems, such a manner has been proposed that a user arranges a special cover for protection over a portion, in which an electromagnetic field occurs for charging, during a charging operation. However, the user may forget about arranging the cover. The cover may be configured to cover automatically the space during the charging instead of a manual operation. This requires a mechanism for such automatic operation, and increases a cost.
An object of the invention is to provide an electric device, which can easily preclude a factor impeding energy transmission in a non-contact manner during charging.
An electric device according to an aspect of the invention includes a charging unit having a unit surface provided with a unit-side terminal for outputting an energy for charging in a non-contact charging operation; a body having a body surface provided with a body-side terminal receiving the energy from the unit-side terminal for charging a battery; and a protection unit protecting a region transmitting the energy by cutting off the region from an external side. The protection unit is a space formed when the body is located on the charging unit with the body surface opposed to the unit surface in the non-contact charging operation, and defined between a surface portion provided with the body-side terminal in the body surface and a surface portion provided with the unit-side terminal in the unit surface.
Accordingly, only by locating the body on the charging unit with the body surface opposed to the unit surface in the non-contact charging operation, the protection unit, which is the space for cutting off the energy transmission region for charging the battery from the external side, is formed by the surface portion provided with the body-side terminal in the body surface and the surface portion provided with the unit-side terminal in the unit surface. Accordingly, a factor impeding the energy transmission in the con-contact charging operation can be easily precluded without arranging a special cover for protecting the energy transmission region.
Preferably, the surface portion provided with the unit-side terminal in the unit surface is a unit-side concavity concaved with respect to its surrounding surface portion. Since the surface portion provided with the unit-side terminal in the unit surface is concaved with respect to the surrounding surface portion, such a situation can be easily avoided that another member damages the unit-side terminal due to contact, even if the unit-side terminal is exposed.
Preferably, the charging unit further has a terminal raising unit for raising the unit-side terminal in the unit-side concavity toward the body surface when the body is located on the charging unit.
Since the unit-side terminal is raised toward the body-side terminal in the non-contact charging operation, such a situation can be avoided that the energy transmission cannot be performed sufficiently due to a large distance between the body-side terminal and the unit-side terminal located within the unit-side concavity.
Preferably, the terminal raising unit raises the unit-side terminal by utilizing a reaction or counteraction to a weight of the body applied to the charging unit when the body is located on the charging unit. Therefore, the raising of the unit-side terminal can be easily achieved by using the reaction to the application of the weight of the body.
Preferably, the surface portion provided with the body-side terminal in the body surface is a body-side concavity concaved with respect to its surrounding surface portion. Since the surface portion provided with the body-side terminal in the body surface is concaved with respect to the surrounding surface, such a situation can be easily avoided that another member damages the body-side terminal due to contact, even if the body-side terminal is exposed.
Preferably, a predetermined portion of the body and a predetermined portion of the charging unit are fitted with each other when the body is placed on the charging unit. Since these portions can be fitted only by locating the body on the charging unit, the body can be easily fixed to the charging unit in the non-contact charging operation.
Preferably, the body and the charging unit are provided with alignment marks for locating the body on the charging unit. By aligning the alignment marks, the body can be easily and reliably located on the charging unit to allow the non-contact charging.
Preferably, the body is a self-propelled robot. Therefore, the foregoing features related to the non-contact charging can be achieved in the self-propelled robot.
An electric device according to another aspect of the invention includes a charging unit having a unit surface provided with a unit-side terminal for outputting an energy for charging in a non-contact charging operation; a body having a body surface provided with a body-side terminal receiving the energy from the unit-side terminal for charging a battery; and a protection unit protecting a region transmitting the energy by cutting off the region from an external side. The protection unit is a space formed when the body is located on the charging unit with the body surface opposed to the unit surface in the non-contact charging operation, and defined between a surface portion provided with the body-side terminal in the body surface and a surface portion provided with the unit-side terminal in the unit surface. The surface portion provided with the unit-side terminal in the unit surface is a unit-side concavity concaved with respect to its surrounding surface portion. The charging unit further has a terminal raising unit for raising the unit-side terminal in the unit-side concavity toward the body surface when the body is located on the charging unit. The terminal raising unit raises the unit-side terminal by utilizing a reaction or counteraction to a weight of the body applied to the charging unit when the body is located on the charging unit. The surface portion provided with the body-side terminal in the body surface is a body-side concavity concaved with respect to its surrounding surface portion. A predetermined portion of the body and a predetermined portion of the charging unit are fitted with each other when the body is placed on the charging unit. The body and the charging unit are provided with alignment marks for locating the body on the charging unit. The body is a self-propelled robot.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
Embodiments of the invention will now be described with reference to the drawings. In each of the following embodiments, a mobile work robot, which is a kind of a self-propelled robot, is employed as an example of a target device to be charged. However, the target device is not restricted to it.
The following description will be primarily given on charging in a non-contact manner. Other functions of self-propelling of the robot and working as well as a mechanism of battery charging by an internal circuit are the same as those already known, and therefore will now be described in detail.
A mark AR2 is formed on the top surface of charging unit 50 for alignment or positioning. For charging, the user places mobile work robot 1 on charging unit 50 such that the mark AR1 on mobile work robot 1 matches with mark AR2 on charging unit 50.
Although not shown, charging unit 50 is internally provided with a circuit unit, which causes high-frequency oscillation by converting a current provided from a commercial power supply to a DC current, and provides a magnetic flux energy produced on a primary side of a transformer (not shown) via charging terminal 62. The magnetic flux energy thus provided is received on a secondary side of the transformer (not shown) in mobile work robot 1, and is rectified for charging battery 21. Therefore, if a metal member or the like is placed on the top surface of charging unit 50, and receives the magnetic flux energy from charging terminal 62, it generates a heat. For preventing such heating, oscillation is caused intermittently when a metal member is placed thereon. When mobile work robot 1 is located thereon, the oscillation is performed continuously to provide the magnetic flux energy in a concentrated fashion, and the intermittent oscillation will be performed again when the end of charging is detected.
Although specific description is not given, mobile work robot 1 transmits a signal, which indicates the completion of the charging, to the primary side of the transformer of charging unit 50 via the secondary side of the transformer in mobile work robot 1 so that charging unit 50 can determine the completion of the charging.
Referring to
For the charging operation, the user places mobile work robot 1 on charging unit 50 such that the button surface of mobile work robot 1 is opposed to the top surface of charging unit 50. In this placing operation, the user positions mobile work robot 1 to align mark AR1 on mobile work robot 1 to mark AR2 on charging unit 50. When mobile work robot 1 is placed, wheels 31-33 are partially fitted into wheel grooves 51-53, respectively. Thereby, wheels 31-33 are engaged with wheel grooves 51-53, respectively, so that mobile work robot 1 is fixed on charging unit 50 (see
When mobile work robot 1 is fixed on charging unit 50 as shown in
In the state shown in
In the above structure, the charging starts in response to the operation of switch 54. However, the structure may be configured to start the charging automatically. For example, sensors (not shown) may be arranged in wheel grooves 51-53 for detecting that wheels 31-33 are engaged with wheel grooves 51-53 as shown in
As shown in
In
Referring to
When the charging is completed in the state shown in
According to the second embodiment, it is possible to determine whether the charging can be performed or not, based on whether the one end of lever 700 is in contact with the wheel or not. Therefore, switching between start and end of the charging may be performed in response to detection/non-detection of such contact. More specifically, lever 700 may be internally provided at its one end with a sensor, which can detect the contact with the wheel so that the charging can be started in response to such detection, and can be ended when the contact is no longer detected.
The foregoing structures use concavity 63 for forming the gap, which is used for the charging, and for protecting the electrode from damage. Instead of concavity 63, a nonconductive member 630 (e.g., a rubber wall) hatched in
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.
Number | Date | Country | Kind |
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2004-121666 | Apr 2004 | JP | national |