Patent Publication Number: US-2013234662-A1

Title: Vehicle-mounted charging device

Description:
TECHNICAL FIELD 
     The present invention relates to an in-vehicle charger to be mounted to a vehicle. 
     BACKGROUND ART 
     With the widespread use of mobile devices, an in-vehicle charger has been suggested which allows the mobile devices to be charged also in the vehicle (see Patent Document 1, for example). 
     Specifically, the in-vehicle charger includes a basal plate having a rectangular installation area on a surface thereof, a charging coil body movably disposed on the surface of the rectangular installation area of the basal plate, a long-side side driving body provided at long-sides side of the rectangular installation area and a short-side side driving body provided at short-sides side of the rectangular installation area. By this configuration, the in-vehicle charger is intended to effectively charge a mobile device by moving the charging coil body in accordance with an installation location of the mobile device. 
     RELATED ART DOCUMENTS 
     Patent Document 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     Patent Document 1: JP-A-2009-247194 
     In the related art above described, since the charging coil body is moved in accordance with the installation location of the mobile device, charging is performed in a state where a charging coil of the mobile device and the charging coil body are opposed to each other. As a result, an efficient charging is performed. 
     In the in-vehicle charger, there is a problem that a vibration due to running of a vehicle or an inertial force due to acceleration or deceleration of the vehicle, for example, affects the charging coil body and therefore the charging coil body itself is unintentionally moved, resulting in a decrease of a charging efficiency. 
     That is, the in-vehicle charger in the related art has a configuration that a driving motor provided in the driving body to drive the charging coil body is also moved together with the charging coil body. When the driving motor is moved integrally with the charging coil body in such a manner, a weight of the charging coil body is substantially heavier and therefore the charging coil can be easily affected by the inertial force. 
     Accordingly, an object of the present invention is to suppress a decrease in a charging efficiency. 
     Means for Solving the Problems 
     A subject matter of the present invention comprises: a basal plate having a rectangular installation area; a charging coil body movably disposed above the rectangular installation area of the basal plate; a long-side side driving body disposed at long-sides side of the rectangular installation area; and a short-side side driving body disposed at short-sides side of the rectangular installation area, wherein the long-side side driving body includes: long racks that extends in a long-side direction of the rectangular installation area; first pinions adapted to roll with respect to the long racks; a first driving shaft connected to the first pinions; and a long-side side motor that generates a driving force to rotate the first pinions, a position of the long-side side motor being fixed with respect to the basal plate, wherein the short-side side driving body includes: short racks that extends in a short-side direction of the rectangular installation area; second pinions adapted to roll with respect to the short racks; a second driving shaft connected to the second pinions; and a short-side side motor that generates a driving force to rotate the second pinions, a position of the short-side side motor is fixed with respect to the basal plate, wherein the charging coil body includes a base and a charging coil mounted to the base, and wherein the base has long-side side through-holes through which the first driving shaft passes toward the long-sides of the rectangular installation area and short-side side through-holes through which the second driving shaft passes toward the short-sides of the rectangular installation area. By this subject matter of the present invention, an advantageous that a decrease in a charging efficiency can be suppressed is obtained. 
     Advantageous Effects of the Invention 
     According to the present invention, it is possible to suppress a decrease in a charging efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an in-vehicle charger according to a first embodiment of the present invention. 
         FIG. 2  is a perspective view showing the in-vehicle charger in a state where an upper plate thereof is removed. 
         FIG. 3  is a perspective view showing the in-vehicle charger in a state where the upper plate and a portion of side plates thereof are removed. 
         FIG. 4  is a perspective view showing a driving mechanism for the charging coil body of the in-vehicle charger. 
         FIG. 5  is a perspective view form below, showing the driving mechanism for the charging coil body of the in-vehicle charger. 
         FIG. 6  is a perspective view from below, showing the charging coil body of the in-vehicle charger. 
         FIG. 7  is a control block diagram of the in-vehicle charger. 
         FIG. 8  is a flowchart showing an operation of the in-vehicle charger. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     An in-vehicle charger according to one aspect of the present invention includes a basal plate having a rectangular installation area, a charging coil body movably disposed above the rectangular installation area of the basal plate, a long-side side driving body disposed at long-sides side of the rectangular installation area and a short-side side driving body disposed at short-sides side of the rectangular installation area. The long-side side driving body includes long racks extending in a long-side direction of the rectangular installation area, first pinions being capable of rolling with respect to the long racks, a first driving shaft connected to the first pinions and a long-side side motor whose position is fixed with respect to the basal plate and which generates a driving force to rotate the first pinions. The short-side side driving body comprises short racks extending in a short-side direction of the rectangular installation area, second pinions being capable of rolling with respect to the short racks, a second driving shaft connected to the second pinions and a short-side side motor whose position is fixed with respect to the basal plate and which generates a driving force to rotate the second pinions. The charging coil body comprises a base and a charging coil mounted to the base. The base is provided with long-side side through-holes which penetrate toward the long-sides of the rectangular installation area and through which the first driving shaft passes and short-side side through-holes which penetrate toward the short-sides of the rectangular installation area and through which the second driving shaft passes. 
     Further, the long-side side through-holes are provided on the side of the charging coil of the base and the short-side side through-holes are provided on the side of the basal plate of the base. And, the first driving shaft and the second driving shaft are arranged in a direction perpendicular to each other and overlapped in such a way that positions thereof in a thickness direction of the charging coil body are deviated. 
     Further, the short-side side through-holes have groove shape which is opened to the basal plate. 
     Further, one of a pair of the short-side side through-holes formed in a groove shape has an opening diameter larger than the other thereof. 
     Further, the in-vehicle charger includes a long-side side feeding screw connected to a driving part of the long-side side motor, a first nut block rotatably holding the first driving shaft is provided on the side of the long-side side feeding screw of the first pinions and is meshed with the long-side side feeding screw, a driving force of the long-side side motor is transmitted to the first pinions and the first driving shaft and the first pinions are rotated and rolled on the long racks in accordance with the rotation of the long-side side feeding screw and the long-side side motor. 
     Further, the in-vehicle charger includes a short-side side feeding screw connected to a driving part of the short-side side motor, a second nut block rotatably holding the second driving shaft is provided on the side of the short-side side feeding screw of the second pinions and is meshed with the short-side side feeding screw, a driving force of the short-side side motor is transmitted to the second pinions and the second driving shaft and the second pinions are rotated and rolled on the short racks in accordance with the rotation of the short-side side feeding screw and the short-side side motor. 
     Further, the long racks are disposed on both opposing long-sides of the rectangular installation area, the first pinions are provided on both ends of the first driving shaft and each of the first pinions is rollably meshed with each of the long racks at the both long-sides. 
     Further, the short racks are disposed on both opposing short-sides of the rectangular installation area, the second pinions are provided on both ends of the second driving shaft and each of the second pinions is rollably meshed with each of the short racks at the both short-sides. 
     Further, the in-vehicle charger of the present invention may include a basal plate having a rectangular installation area on a surface thereof, a charging coil body movably disposed on the surface of the rectangular installation area of the basal plate, a long-side side driving body provided at long-sides side of the rectangular installation area and a short-side side driving body provided at short-sides side of the rectangular installation area. The long-side side driving body may include long racks disposed on both long-sides of the rectangular installation area, a long-side side feeding screw disposed on at least one of the long-sides and a long-side side motor connected to the long-side side feeding screw. Further, the short-side side driving body may include short racks disposed on both short-sides of the rectangular installation area, a short-side side feeding screw disposed on at least one of the short-sides and a short-side side motor connected to the short-side side feeding screw. The charging coil body may include the base and the charging coil mounted to the base. The base may be provided with long-side side through-holes which penetrate toward the long-sides of the rectangular installation area and short-side side through-holes which penetrate toward the short-sides of the rectangular installation area. The first pinions may be provided on both end portions of the first driving shaft passing through the long-side side through-holes and are meshed with the long racks. The second pinions may be provided on both end portions of the second driving shaft passing through the short-side side through-holes and are meshed with the short racks. 
     By this configuration, the weight of the charging coil body  8  becomes lighter and thus the charging coil is hardly affected by an inertial force, so that an opposing relationship of the charging coil of the mobile phone and the charging coil body is hardly deviated and therefore it is possible to suppress the decrease in the charging efficiency. 
     Hereinafter, an illustrative embodiment of the present invention will be described with reference to the drawings. 
     First Embodiment 
     By referring to  FIG. 1 , a reference numeral  1  denotes a body case and the body case  1  is configured by mounting an upper case  3  ( FIG. 1 ) with an open lower surface on a lower case  2  ( FIG. 2 ) with an open upper surface. 
     Further, the upper case  3  includes an upper plate  4  on which a mobile device is placed when charging is performed. 
     Meanwhile, the lower case  2  includes a basal plate  6  having a rectangular installation area  5  on a surface thereof and side plates  7  covering an outer periphery of the basal plate  6 . 
     Further, a charging coil body  8  is movably disposed on the surface of the rectangular installation area  5  of the lower case  2 . In addition, as shown in  FIG. 4  and  FIG. 5 , a long-side side driving body  9  is arranged at long-sides side of the rectangular installation area  5  and a short-side side driving body  10  is arranged at short-sides side of the rectangular installation area  5 . The long-side side driving body  9  and the short-side side driving body  10  are fixed on the basal plate  6  of the lower case  2 . Meanwhile, in the rectangular installation area  5 , a long-side direction is defined as Y axis direction and a short-side direction perpendicular to the long-side direction is defined as X axis direction. 
     The long-side side driving body  9  includes long racks  11  disposed on both opposing long-sides of the rectangular installation area  5 , a long-side side feeding screw  12  disposed on at least one of the long-sides and a long-side side motor  13  connected to the long-side side feeding screw  12 . The long racks  11  extend in the long-side direction of the rectangular installation area  5  and first pinions  22  are rollably meshed with the long racks  11 . As the long-side side motor  13  is rotated, the long-side side feeding screw  12  connected to a driving part of the motor is rotated together and a driving force is generated. And, the first pinions  22  are rotated and rolled on the long racks  11  by the driving force. Here, the position of the long-side side motor  13  is directly or indirectly fixed with respect to the basal plate  6  and a driving force of the long-side side motor  13  is transmitted to the first pinions  22  via the long-side side feeding screw  12 , so that the first pinions  22  are moved along the long racks  11  while being rotated. 
     Further, the short-side side driving body  10  includes short racks  14  disposed on both opposing short-sides of the rectangular installation area  5 , a short-side side feeding screw  15  disposed on at least one of the short-sides and a short-side side motor  16  connected to the short-side side feeding screw  15 . The short racks  14  extend in the short-side direction of the rectangular installation area  5  and second pinions  24  are rollably meshed with the short racks  14 . As the short-side side motor  16  is rotated, the short-side side feeding screw  15  connected to a driving part of the motor is rotated together and a driving force is generated. And, the second pinions  24  are rotated and rolled on the short racks  14  by the driving force. Here, the position of the short-side side motor  16  is directly or indirectly fixed with respect to the basal plate  6  and a driving force of the short-side side motor  16  is transmitted to the second pinions  24  via the short-side side feeding screw  15 , so that the second pinions  24  are moved along the short racks  14  while being rotated. 
     Furthermore, the charging coil body  8  includes a square-shaped base  17  and a circular charging coil  18  mounted on the base  17 , as shown in  FIG. 2  to  FIG. 4 . 
     Further, as shown in  FIG. 6  and  FIG. 7 , the base  17  has long-side side through-holes  19  penetrating toward the long-sides of the rectangular installation area  5  and short-side side through-holes  20  penetrating toward the short-sides of the rectangular installation area  5 . 
     And, as shown in  FIG. 3  and  FIG. 4 , both end portions of a first driving shaft  21  passing through the long-side side through-holes  19  are connected to the first pinions  22  which are meshed with the long racks  11  so as to be rolled along an extension direction of the rack. The long racks  11  and the long-side side feeding screw  12  are disposed substantially parallel to each other and a first nut block  31  is provided on the side of the long-side side feeding screw  12  of the first pinions  22 . The first nut block  31  holds the first driving shaft  21  in a rotatable state and is meshed with the long-side side feeding screw  12  to transmit a driving force of the long-side side motor  13  to the long-side side driving body  9  including the first pinions  22  and the first driving shaft  21 . As the first pinions  22  are rotated by the driving force of the long-side side motor  13 , the first driving shaft  21  is moved in the long-side direction while being rotated in conjunction with the first pinions  22 . Here, the first pinions  22  may be configured by a two-stage gear and the first pinions  22  may be directly meshed with the long-side side feeding screw  12 . 
     Further, both end portions of a second driving shaft  23  passing through the short-side side through-holes  20  are connected to the second pinions  24  which are meshed with the short racks  14  so as to be rolled along an extension direction of the rack. The short racks  14  and the short-side side feeding screw  15  are disposed substantially parallel to each other and a second nut block  32  is provided on the side of the short-side side feeding screw  15  of the second pinions  24 . The second nut block  32  holds the second driving shaft  23  in a rotatable state and is meshed with the short-side side feeding screw  15  to transmit a driving force of the short-side side motor  16  to the short-side side driving body  10  including the second pinions  24  and the second driving shaft  23 . As the second pinions  24  are rotated by the driving force of the short-side side motor  16 , the second driving shaft  23  is moved in the short-side direction while being rotated in conjunction with the second pinions  24 . Here, the second pinions  24  may be configured by a two-stage gear and the second pinions  24  may be directly meshed with the short-side side feeding screw  15 . 
     As shown in  FIG. 5  and  FIG. 6 , the long-side side through-holes  19  are disposed on the side of the charging coil  18  of the base  17  and the short-side side through-holes  20  are disposed on the side of the basal plate  6  of the base  17 . Out of these through-holes, each of the short-side side through-holes  20  has a groove shape which is opened to the basal plate  6 . For example, each of the short-side side through-hole  20  is formed in a U-shaped groove. 
     Meanwhile, one of the short-side side through-holes  20  formed in a groove shape has an opening diameter larger than the other thereof, which will be described in detail later. 
       FIG. 7  shows a control block of the in-vehicle charger. Here, the long-side side motor  13  performs a Y axis direction driving and is connected to a control unit  26  via a Y axis motor control unit  25 . 
     Similarly, the short-side side motor  16  performs an X axis direction driving and is connected to the control unit  26  via an X axis motor control unit  27 . 
     Further, the charging coil  18  is connected to the control unit  26  via a charging coil control unit  28 . 
     Further, a position detection coil  29  is connected to the control unit  26  via a detection coil control unit  30  and is intended to detect the position of a charging coil of a mobile device installed on the upper plate  4 . 
     Since a method to detect the position of the charging coil of the mobile device using the position detection coil  29  and the detection coil control unit  30  is disclosed in detail in the above-described Patent Document 1, a detailed description thereof is omitted herein for convenience in explanation. The position detection coil  29  is configured in such a way that a plurality of coils is arranged in parallel at predetermined intervals in X axis and Y axis directions in the rectangular installation area  5 . The detection coil control unit  30  supplies a pulse signal to each coil of the position detection coil  29 , detects the position of the charging coil depending on the level of an echo signal for the pulse signal and outputs a position detection signal. 
     The control unit  26  is configured by an information processing device such as a micro-computer, for example and each function thereof is realized by executing a predetermined software program. Here, the control unit  26  may have each function of the Y axis motor control unit  25 , the X axis motor control unit  27 , the charging coil control unit  28  and the detection coil control unit  30 . 
     In the above configuration, when a mobile device is installed on the upper plate  4  in order to charge the mobile device, the control unit  26  detects the position of the charging coil of the mobile device using the position detection coil  29  and the detection coil control unit  30  (S 1 , S 2 , S 3 , S 4  in  FIG. 8 ). At this time, the control unit  26  instructs the detection coil control unit  30  to execute a charging coil detection control (S 1 ) and determines the presence or absence of the detection of the charging coil (S 2 ). Further, the control unit  26  executes a charging coil position detection control (S 3 ) and determines whether the position detection of the charging coil was confirmed (S 4 ). From the detection coil control unit  30 , a position detection signal is inputted to the control unit  26 . Based on the result of the charging coil position detection, the control unit  26  drives the Y axis motor control unit  25  and the X axis motor control unit  27  so as to move the charging coil  18  to a position opposing to the charging coil of the mobile device, so that the motor control (charging coil movement control) in X and Y directions is performed (S 5  in  FIG. 8 ). 
     And, when the position of the charging coil  18  is confirmed, the control unit  26  supplies power to the charging coil  18  via the charging coil control unit  28 , so that the charging is started (S 6  in  FIG. 8 ). 
     In the above operation, the charging coil  18  is driven by the long-side side motor  13  and the short-side side motor  16 . In this case, either one of these motors may be operated or both motors may be simultaneously operated. 
     First, the long-side side motor  13  is described. As the long-side side motor  13  is driven, the long-side side feeding screw  12  is rotated and therefore the first pinions  22  meshed with the long-side side feeding screw are rotated. 
     At this time, since both first pinions  22  at both ends of the first driving shaft  21  are in a state of being rolled on the long racks  11 , a very smooth rolling movement is performed. 
     Further, since the first driving shaft  21  is in a state of passing through the long-side side through-holes  19  provided in the base  17  of the charging coil body  8 , as described above, the base  17  of the charging coil body  8 , that is, the charging coil  18  is moved in a moving direction of the first pinions  22  described above. 
     Further, as the short-side side motor  16  is driven, the short-side side feeding screw  15  is rotated and therefore the second pinions  24  meshed with the short-side side feeding screw are rotated. 
     At this time, since both second pinions  24  at both ends of the second driving shaft  23  are in a state of being rolled on the short racks  14 , a very smooth rolling movement is performed. 
     Further, since the second driving shaft  23  is in a state of passing through the short-side side through-holes  20  provided in the base  17  of the charging coil body  8 , as described above, the base  17  of the charging coil body  8 , that is, the charging coil  18  is moved in a moving direction of the second pinions  24  described above. 
     In such a moving situation of the charging coil  18 , since each of the short-side side through-holes  20  provided on the base  17  of the charging coil body  8  has a groove shape which is opened to the basal plate  6 , as described above, the movement of the charging coil  18  is smoothly performed. At this time, the stress in a direction perpendicular to a rotation axis of the second driving shaft  23  is absorbed by the groove shape of each of the short-side side through-holes  20 , so that the charging coil body  8  can be smoothly moved. 
     Further, as shown in  FIG. 5  and  FIG. 6 , the long-side side through-holes  19  provided on the base  17  of the charging coil body  8  are arranged on the side of the charging coil  18  of the base  17  and has a shape to penetrate the base  17  toward both long racks  11 . And, the short-side side through-holes  20  are arranged on the side of the base  17  opposite to the charging coil  18 , i.e., on the side of the basal plate  6  of the base  17  and has a shape to penetrate the base  17  toward both short racks  14 . Further, each of the short-side side through-hole  20  of the base  17  has a groove shape which is opened to the basal plate  6 . In this way, the present embodiment has a configuration that the first driving shaft  21  and the second driving shaft  23  are arranged in a direction perpendicular to each other and overlapped in such a way that positions thereof in a thickness direction of the charging coil body  8  are deviated. Further, the present embodiment has a configuration that the short-side side through-holes  20  having the groove shape are adapted to receive the second driving shaft  23  which is longer. Since the second driving shaft  23  can be slightly displaced in a direction perpendicular to a rotation axis thereof by the groove shape, the friction during the rotation of the driving shaft can be reduced. Consequently, it is possible to prevent the charging coil body  8  from being non-smoothly moved due to the friction. 
     As a result, the charging coil  18  can be smoothly moved toward the long-side side and the short-side side. 
     Furthermore, under this situation, since one of the short-side side through-holes  20  formed in a groove shape has an opening diameter larger than the other thereof, the charging coil  18  can be smoothly moved to the long-side side and the short-side side, also from this point. In a case where one of two opposing short-side side through-holes  20  has an opening diameter larger than the other thereof, for example, one short-side side through-hole  20  away from the short-side side driving body  10 , i.e., one short-side side through-hole (away from a driving source) located at a downstream side in a transmission direction of a driving force from the short-side side driving body  10  has an opening diameter larger than the other. By doing so, since the stress in a direction perpendicular to a rotation axis of the second driving shaft  23  is absorbed, not only it is possible to smoothly move the charging coil body  8  and but also it is possible to reduce the transmission loss of the driving force from the short-side side driving body  10 . Similarly, one of the long-side side through-holes  19  may be formed in an elongate hole and have an opening diameter larger than the other thereof. 
     That is, since the longer second driving shaft  23  is in a state of passing through the short-side side through-holes  20  as shown in  FIG. 5  and  FIG. 6  and a deformation amount of the longer second driving shaft  23  is larger than that of the shorter first driving shaft  21 , it is intended to allow a smooth operation by absorbing the deformation. By forming the through-holes to receive the longer driving shaft (in which a deformation amount when driving is large and a friction is likely to occur) in groove shape, higher effect is obtained. 
     As described above, in the present embodiment, the long-side side motor  13  and the short-side side motor  16  are fixed to the lower case  2  and separated from the charging coil body  8 , in view of the movement. When the charging coil body  8  is driven, a moving part is only composed of the charging coil  18  and the base  17 , the first driving shaft  21  and the first pinions  22 , and the second driving shaft  23  and the second pinions  24 . As a result, the weight of the charging coil body  8  becomes lighter and thus the charging coil is hardly affected by an inertial force, so that an opposing relationship of the charging coil of the mobile phone and the charging coil body is hardly deviated and therefore it is possible to suppress the decrease in the charging efficiency. 
     As described above, the in-vehicle charger according to the illustrative embodiment of the present invention includes the long-side driving body provided at long-sides side of the rectangular installation area of the basal plate and the short-side driving body provided at short-sides side of the rectangular installation area. The long-side side driving body includes long racks disposed on both long-sides of the rectangular installation area, a long-side side feeding screw disposed on at least one of the long-sides and a long-side side motor connected to the long-side side feeding screw. Further, the short-side side driving body includes short racks disposed on both short-sides of the rectangular installation area, a short-side side feeding screw disposed on at least one of the short-sides and a short-side side motor connected to the short-side side feeding screw. The charging coil body includes the base and the charging coil mounted to the base. The base is provided with the long-side side through-holes which penetrate toward the long-sides of the rectangular installation area and short-side side through-holes which penetrate toward the short-sides of the rectangular installation area. The first pinions are provided on both end portions of the first driving shaft passing through the long-side side through-holes and are meshed with the long racks. The second pinions are provided on both end portions of the second driving shaft passing through the short-side side through-holes and are meshed with the short racks. Accordingly, the long-side side motor and the short-side side motor are separated from the charging coil body, in view of the movement. As a result, the weight of the charging coil body becomes lighter and thus the charging coil is hardly affected by an inertial force, so that it is possible to suppress the decrease in the charging efficiency. 
     Accordingly, the present invention is expected to be utilized as the in-vehicle charger. 
     Although the present invention has been described in detail with reference to particular illustrative embodiments, the present invention is not limited to the illustrative embodiments and it is obvious to those skilled in the art that the illustrative embodiments can be variously modified and combined without departing a spirit and a scope of the present invention. 
     This application is based upon Japanese Patent Application (Patent Application No. 2011-191346) filed on Sep. 2, 2011 and the contents of which are incorporated herein by reference. 
     INDUSTRIAL APPLICABILITY 
     The present invention has an effect to suppress a decrease in a charging efficiency and is useful as an in-vehicle charger or the like to be mounted to a vehicle. 
     DESCRIPTION OF REFERENCE NUMERALS AND SIGNS 
     
         
           1  body case 
           2  lower case 
           3  upper case 
           4  upper plate 
           5  rectangular installation area 
           6  basal plate 
           7  side plate 
           8  charging coil body 
           9  long-side side driving body 
           10  short-side side driving body 
           11  long rack 
           12  long-side side feeding screw 
           13  long-side side motor 
           14  short rack 
           15  short-side side feeding screw 
           16  short-side side motor 
           17  base 
           18  circular charging coil 
           19  long-side side through-hole 
           20  short-side side through-hole 
           21  first driving shaft 
           22  first pinion 
           23  second driving shaft 
           24  second pinion 
           25  Y axis motor control unit 
           26  control unit 
           27  X axis motor control unit 
           28  charging coil control unit 
           29  position detection coil 
           30  detection coil control unit 
           31  first nut block 
           32  second nut block