INDUCTION CHARGING DEVICE

Abstract

An induction charging device, in particular, a hand-held power tool induction charging device, including a coil unit and at least one shielding unit, which is for at least partially shielding the coil unit. It is provided that the induction charging device includes at least one adjustment unit, with the aid of which at least one shielding parameter of the at least one shielding unit is changeable.

Claims

1. An induction charging device, comprising: a coil unit; at least one shielding unit for at least partially shielding the coil unit; and at least one adjustment unit to change a shielding parameter of at least one shielding unit.

2. The induction charging device of claim 1, wherein the at least one shielding unit includes at least one shielding element.

3. The induction charging device of claim 2, wherein the at least one shielding element includes at least one at least essentially radial slot, which interrupts the at least one shielding element in at least one operating state.

4. The induction charging device of claim 3, further comprising: at least one switch element, via which the at least one at least essentially radial slot can be electrically closed and/or opened.

5. The induction charging device of claim 3, wherein the adjustment unit is configured to open and/or to close the at least one at least essentially radial slot as a function of an operating state in order to change the shielding parameter.

6. The induction charging device of claim 1, wherein the adjustment unit is configured to switch the shielding unit between a short-circuit mode and an idle mode to change the shielding parameter.

7. The induction charging device of claim 6, further comprising: at least one control unit, with which a switching is able to take place between a short-circuit mode and an idle mode.

8. The induction charging device of claim 1, wherein the adjustment unit is configured to change a resonance frequency of an oscillator circuit of the coil unit by changing a shielding parameter of the at least one shielding unit.

9. A method for operating an induction charging device, the method comprising: performing at least one of the following: opening, via an adjustment unit of the induction charging device, at least one at least essentially radial slot of at least one shielding element to lower a resonance frequency of an oscillator circuit of a coil unit; and closing, via the adjustment unit, the at least one at least essentially radial slot of the at least one shielding element to increase a shielding of the coil unit; wherein the induction charging device includes the coil unit, the at least one shielding unit for at least partially shielding the coil unit, and the at least one adjustment unit to change the shielding parameter of the at least one shielding unit.

10. The method of claim 9, wherein the induction charging device includes a hand-held power tool induction charging device.

11. The induction charging device of claim 1, wherein the induction charging device includes a hand-held power tool induction charging device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 shows a system, including an induction charging device according to the present invention and including an induction rechargeable battery in a schematic, perspective view.

[0022] FIG. 2 shows the induction charging device according to the present invention, including a coil unit and including a shielding unit in a schematic exploded view.

[0023] FIG. 3 shows the induction charging device according to the present invention, including an opened exterior housing in a schematic view from below.

[0024] FIG. 4 shows the coil unit of the induction charging device according to the present invention in a schematic exploded view.

[0025] FIG. 5 schematically shows a flow chart of a method for operating the induction charging device according to the present invention.

DETAILED DESCRIPTION

[0026] FIG. 1 depicts a system, including an induction charging device 10 and including an induction rechargeable battery 26. Induction charging device 10 is provided to electrically charge induction rechargeable battery 26 in a charge state. Induction rechargeable battery 26 is configured as a hand-held power tool induction rechargeable battery. Induction rechargeable battery 26 is configured to be inductively chargeable with the aid of induction charging device 10. Induction rechargeable battery 26 is configured to be coupleable with induction charging device 10. Induction charging device 10 is provided for transferring an energy to induction rechargeable battery 26 in a state coupled with induction rechargeable battery 26. Induction charging device 10 is configured as a hand-held power tool induction charging device. Induction charging device 10 is configured as an induction charging unit. Induction charging device 10 includes a coil unit 12. Induction charging device 10 also includes an exterior housing 28. Exterior housing 28 surrounds coil unit 12. Exterior housing 28 includes two housing shells 30, 32. Exterior housing 28 includes an upper housing shell 30 and a lower housing shell 32 which, not further visible, are screwed together. In principle, however, a detent connection and/or an adhesive bond between housing shells 30, 32 would also be conceivable. Coil unit 12 is provided for inductively transferring energy to induction rechargeable battery 26 in a charge state. Induction charging device 10 includes an electronics unit 34, which is provided to control or regulate a charging operation. Electronics unit 34 includes at least one circuit board 36 fitted with electronic components. Circuit board 36 includes a copper coating on a side facing away from coil unit 12 of induction charging device 10. In addition, circuit board 36 of electronics unit 34 includes an SMD assembly on a side facing away from coil unit 12 of induction charging device 10.

[0027] Exterior housing 28 of induction charging device 10 includes a holding area 38, which is provided for holding induction rechargeable battery 26 in a coupled state. Induction rechargeable battery 26 also includes a housing 40, which includes a positioning element 42 for coupling induction rechargeable battery 26 to holding area 38 of exterior housing 28 of induction charging device 10 in a coupled state.

[0028] Positioning element 42 of induction rechargeable battery 26 is configured as a platform, which rises above an outer surface of adjoining housing 40 of induction rechargeable battery 26. Holding area 38 of exterior housing 28 of induction charging device 10 includes at least one recess. The recess forms a positioning element 44 for positioning induction rechargeable battery 26. It is also conceivable, however, that positioning element 44 of induction charging device 10 is configured as a platform and positioning element 42 of induction rechargeable battery 26 is configured as a recess. The recess has a step height of at least 0.5 mm. Positioning element 42 of induction rechargeable battery 26 has a step height of at least 0.5 mm. Positioning element 44 of induction charging device 10 and positioning element 42 of induction rechargeable battery 26 are correspondingly configured.

[0029] Positioning element 44 of induction charging device 10 and positioning element 42 of induction rechargeable battery 26 each have a step height of 3 mm. Other dimensions, which appear meaningful to those skilled in the art, are also conceivable, however. Positioning element 44 of induction charging device 10 has a partially curved outer contour. The outer contour of positioning element 44 of induction charging device 10 is rounded. Positioning element 42 of induction rechargeable battery 26 has a partially curved outer contour. The outer contour of positioning element 42 of induction rechargeable battery 26 is square with rounded corners. A diameter of positioning element 44 of induction charging device 10 corresponds at least virtually to a diagonal length of positioning element 42 of induction rechargeable battery 26. A minimal tolerance is provided between the dimensions of positioning element 44 of induction charging device 10 and of positioning element 42 of induction rechargeable battery 26. Alternatively, it is also conceivable that the outer contour of positioning element 44 of induction charging device 10 is square with rounded corners and the outer contour of positioning element 42 of induction rechargeable battery 26 is round. It is further conceivable that the outer contour of positioning element 44 of induction charging device 10 or of positioning element 42 of induction rechargeable battery 26 has another geometric shape, which appears meaningful to those skilled in the art, in particular, with rounded corners. In a charge state, induction rechargeable battery 26 rests on induction charging device 10, so that positioning element 42 of induction rechargeable battery 26 engages in positioning element 44 of induction charging device 10. In the process, housing 40 of induction rechargeable battery 26 directly contacts exterior housing 28 of induction charging device 10.

[0030] Induction charging device 10 includes coil unit 12, which is provided to transfer energy in a state coupled to an induction rechargeable battery 26. Electrical energy is transferred in the coupled state from induction charging device 10 to induction rechargeable battery 26 with the aid of coil unit 12. Coil unit 12 includes at least one core element 46 and at least one induction coil 48, which at least partially surrounds the at least one core element 46 (FIG. 4). Coil unit 12 includes six identically shaped core elements 46 and one induction coil 48, which surrounds core elements 46 in the circumferential direction. Induction coil 48 includes multiple windings situated one on top of the other. Induction coil 48 includes two coil connections 50, which are configured spaced apart from one another. Induction coil 48 has a round contour. Induction coil 48 has a circular basic shape. Induction coil 48 may alternatively also have a non-circular, for example, oval, rectangular or square basic shape. Core elements 46 each have a partially circular design. In a mounted state, core elements 46 are situated next to one another in such a way that the six core elements 46 together form a circular contour. Core elements 46 are provided to partially inductively shield electronics unit 34 of induction charging device 10. Core elements 46 are provided for increasing an inductance of the at least one induction coil 48. Core elements 46 are formed from a metal. Core elements 46 are configured as ferrite cores.

[0031] Core elements 46 each have a protrusion 52 on a side facing away from holding area 38. Induction coil 48 encompasses core elements 46 in a mounted state in the circumferential direction.

[0032] Protrusion 52 of core elements 46 has a larger diameter than a winding diameter of induction coil 48. Induction coil 48 is situated in a mounted state between protrusions 52 of core elements 46 and holding area 38 of induction charging device 10 in the axial direction, which runs perpendicular to the diameter of the windings of induction coil 48. The side of core element 46 facing away from induction coil 48 is formed by an essentially planar surface.

[0033] Induction charging device 10 further includes a coil housing unit, which surrounds coil unit 12. The coil housing unit includes two coil housing elements 54, 56 which, in the mounted state, are coupled to one another via a detent element 58. The coil housing unit has a largely cylindrically shaped outer contour. A first coil housing element of coil housing elements 54 has two detent elements 58 (FIG. 3). Detent elements 58 are permanently connected to first coil housing element 54. Detent elements 58 and first coil housing element 54 are configured as a single piece. Detent elements 58 are formed by snap hooks. Detent elements 58 are situated in a center of first coil housing element 54. Detent elements 58 are configured to be resiliently deflectable in the radial direction of first coil housing element 54. Another coil housing element of coil housing elements 56 is provided to hold induction coil 48. Additional coil housing element 56 is also provided to hold core elements 46 in a mounted state. Additional coil housing element 56 is configured as a coil carrier. Core elements 46 and induction coil 48 of coil unit 12 in a mounted state are at least virtually completely enclosed in additional coil housing element 56 configured as a coil carrier. Additional coil housing element 56 further includes a detent recess 60, which is configured to correspond to detent elements 58 of first coil housing element 54. Detent recess 60 is situated in a center of additional coil housing element 56. In a mounted state, detent elements 58 of first coil housing element 54 reach through detent recess 60 of additional coil housing element 56 and are locked in place with the additional coil housing element. Thus, in the mounted state, coil housing elements 54, 56 are connected to one another in a form-locked manner.

[0034] Induction charging device 10 further includes a shielding unit 14. Shielding unit 14 is provided to partially shield coil unit 12. Shielding unit 14 is provided to reduce electromagnetic disturbances. Shielding unit 14 includes a shielding element 18. For the function of shielding element 18, it is important that shielding element 18 be situated in induction charging device 10 between coil unit 12 and exterior housing 28, in particular, between coil unit 12 and second housing shell 32. In this configuration, one side of shielding element 18 faces second housing shell 32, whereas the other opposite side of shielding element 18 faces coil unit 12. Thus, during a charging operation of an induction rechargeable battery 26 with induction charging device 10, shielding element 18 is situated between coil unit 12 and second housing shell 32. During the charging operation, second housing shell 32 forms a standing surface for induction charging device 10, for example, a table surface. Shielding element 18 is situated between coil housing element 56 and second housing shell 32. In an alternative specific embodiment not depicted, shielding element 18 may also form an element of coil unit 12. In this case, shielding element 18 may be situated in coil housing element 56. In this case, shielding element 18 may be situated, in particular, between coil housing element 56 and core elements 46.

[0035] In the depicted specific embodiment, shielding element 18 is detachably fastened in induction charging device 10 with the aid of fastening elements in the form of screws. The fastening elements interact with the retaining elements of upper housing shell 30. In this way, shielding element 18 is detachably fastened to upper housing shell 30. One of the fastening elements also assumes the function of establishing an electrically conductive connection between shielding element 18 and an electric line in the form of a cable. Shielding element 18 is connected via the electric line to a ground. Shielding element 18 is formed from an electrically conductive material. It is advantageously formed from a metallic material. Shielding element 18 is made of aluminum. Shielding element 18 is configured to shield coil unit 12 from metallic objects located on a standing surface for induction charging device 10, for example, on a table surface. A standing surface made of a metallic material or metallic particles on the standing surface influence the function of coil unit 12 in a disadvantageous manner. Shielding element 18 has an essentially ring-shaped design. Shielding element 18 is formed by an aluminum ring. In one alternative specific embodiment not depicted, shielding element 18 may also have a disk-shaped design. Shielding element 18 in this case may have, in particular, a full-surface design. To achieve a sufficient mechanical stability, shielding element 18 has a thickness, for example, of approximately 1 mm, however, shielding element 18 may also have a significantly smaller thickness.

[0036] It is advantageous for the function of shielding element 18 if shielding element 18 has what may be a large surface expansion relative to the surface encompassed by induction coil 48.

[0037] Shielding element 18 has a surface expansion, which corresponds at least essentially to the surface formed by induction coil 48. The essentially circular shielding element 18 has an outer diameter, which is at least as large as the outer diameter of induction coil 48. In one alternative specific embodiment, in which induction coil 48 is not ring-shaped, but rather is, for example, oval, rectangular or square, the geometric basic shape of shielding element 18 is advantageously adapted to the basic shape of induction coil 48. In this case, a projection surface of shielding element 18 formed in a projection of shielding element 18 along the axial direction is at least approximately as large as the projection surface of induction coil 48, which in a projection of induction coil 48 is formed along the axial direction.

[0038] Shielding element 18 includes a radial slot 20. Slot 20 extends perpendicular to a center axis 62 of shielding element 18. A direction of extension of slot 20 intersects center axis 62. Center axis 62 in this case is formed by a surface normal of a main extension plane of shielding element 18, which extends through a geometric center point of shielding element 18. In principle, however, another extension of slot 20, which appears meaningful to those skilled in the art, would also be conceivable. Slot 20 interrupts shielding element 18 in at least one operating state. Slot 20 forms a gap in shielding element 18, in which there is a void in the material of shielding element 18.

[0039] Shielding unit 14 further includes an additional shielding element 64. Additional shielding element 64 is situated in induction charging device 10 between coil unit 12 and holding area 38. In this configuration, one side of additional shielding element 64 faces holding area 38, whereas the other opposite side of additional shielding unit 64 faces induction coil 48. Thus, during a charging operation of induction rechargeable battery 26 with induction charging device 10, additional shielding element 64 is situated between induction coil 48 and induction rechargeable battery 26 or between induction coil 48 and an induction coil 48 of induction rechargeable battery 26. Additional shielding element 64 is configured to form a bypass capacitor with induction coil 48 of induction charging device 10. Induction coil 48 in this case forms a first electrode of the bypass capacitor and additional shielding element 64 forms a second electrode of the bypass capacitor.

[0040] Induction charging device 10 further includes a switch element 22. With switch element 22, it is possible to electrically close and/or open radial slot 20 of shielding element 18. Radial slot 20 may be electrically bridged by switch element 22. Switch element 22 has two states, whereby one state of switch element 22 may be altered with the aid of an external control signal. For this purpose, switch element 22 includes a control contact not otherwise visible, via which it may be switched. Switch element 22 is provided to establish and/or disconnect an electrically conductive connection between two sides of slot 20 of shielding element 18. Switch element 22 is formed by an electrical switch. In principle, however, it would also be conceivable that switch element 22 is formed by a mechanical switch element. In this case, it would be conceivable, in particular, that switch element 22 includes an element made of a conductive material, in particular, aluminum, the size of which corresponds at least essentially to a size of slot 20, and which may be moved via a mechanism into or out of slot 20. In this way, slot 20 could be, in particular, temporarily closed or opened.

[0041] Thus, a bridging could be achieved both by a mechanical closing of slot 20 as well as via a purely electronic bridging of slot 20.

[0042] In addition, induction charging device 10 includes an adjustment unit 16. A shielding parameter of shielding unit 14 is changeable with the aid of adjustment unit 16. Adjustment unit 16 is connected to electronics unit 34 of induction charging device 10. Adjustment unit 16 forms a part of electronics unit 34. Adjustment unit 16 is provided to open or to close radial slot 20 as a function of an operating state in order to change the shielding parameter. For this purpose, adjustment unit 16 is connected to switch element 22. Adjustment unit 16 is provided to activate switch 22. A shielding parameter of shielding unit 14 may be changed by an opening or closing of slot 20. For this purpose, adjustment unit 16 is provided to switch shielding unit 14 between a short-circuit mode and an idle mode for changing the shielding parameter.

[0043] Adjustment unit 16 is provided for switching between a short-circuit mode and an idle mode in order to activate switch element 22. In a short-circuit mode, radial slot 20 of shielding element 18 is closed or bridged. In an idle mode, radial slot 20 of shielding element 18 is opened. In the short-circuit mode of shielding unit 14, shielding element 18 functions as a short-circuit ring. Shielding element 18 provides an advantageous shielding in the short-circuit mode. In the short circuit mode, the current induced into shielding element 18 generates an electromagnetic force, which is phase-shifted as compared to that of coil unit 12. A magnetic field of shielding element 18 formed in this way partially cancels out an effect of the magnetic field of coil unit 12 in the direction in which shielding element 18 is situated. Thus, a magnetic field of coil unit 12 is bent away from the bottom of induction charging device 10 during the short-circuit mode. This reduces the influence of various materials as a support for induction charging device 10. The bending of the magnetic field of coil unit 12 is associated with an increase of the magnetic resistance. This results in a reduced inductance of coil unit 12 and an increased resonance frequency of a primary oscillator circuit. In the idle mode, on the other hand, a shielding effect of shielding element 18 is significantly reduced. Because of slot 20 in shielding element 18, an induced current generates only isolated eddy currents. A magnetic field of shielding element 18 formed in this way is too weak to significantly reduce an effect of the magnetic field of coil unit 12 in the direction in which the shielding element 18 is situated. The reduced shielding is associated with a reduced magnetic resistance as compared to the short-circuit mode. This results in a higher inductance of coil unit 12 and a reduced resonance frequency of the primary oscillator circuit.

[0044] Adjustment unit 16 is provided to change a resonance frequency of an oscillator circuit of coil unit 12 by changing the shielding parameter of shielding unit 14. By switching between the short-circuit mode and the idle mode, it is possible to adapt the resonance frequency of the primary oscillator circuit of coil unit 12. In this way, the resonance frequency may be regulated by adjustment unit 16 to an optimal value. Adjustment unit 16 is activated for this purpose via electronics unit 34 of induction charging device 10.

[0045] Induction charging device 10 further includes a control unit 24. With the aid of control unit 24, it is possible to manually switch between a short-circuit mode and an idle mode. With the aid of control unit 24, an operator may manually switch between a short-circuit mode and an idle mode. For this purpose, control unit 24 is connected to adjustment unit 16. This could, for example, enable an operator to indicate manually whether induction charging device 10 is standing on a non-magnetic base on a ferromagnetic base and/or on a diamagnetic or paramagnetic base, in order to enable an advantageously efficient charging operation. Control unit 24 is formed by a slide switch. Control unit 24 has three positions. A first position of control unit 24 defines a short-circuit mode, a second position of control unit 24 defines an idle mode and a third position of control unit 24 defines an automatic mode. In the automatic mode, a switching by adjustment unit 16 takes place automatically between the short-circuit mode and the idle mode.

[0046] FIG. 5 schematically shows a flow chart of a method for operating induction charging device 10. In the method, adjustment unit 16 opens radial slot 10 of shielding element 18 in order to lower a resonance frequency of an oscillator circuit of coil unit 12, or closes radial slot 20 of shielding element 18 in order to increase a shielding of coil unit 12. During the operation of induction charging device 10, a position of control unit 24 is checked after a start 66 in a first branch 68. If control unit 24 is in a first position, radial slot 20 of shielding element 18 is closed or remains closed in a further method step 70. If control element 24 is in a second position, radial slot 20 of shielding element 18 is opened or remains open in a further method step 72. If control unit 24 is in a third position, a magnetism of a base of induction charging device 10 is sensed in a further method step 74. This may occur, for example, via a separate sensor such as, for example, a magnetic sensor. In principle, however, it would also be conceivable to sense the magnetism by monitoring the oscillator circuit of coil unit 12 during a switch between the short-circuit mode and the idle mode. The sensed values are subsequently evaluated in a branch 76. If the base is made of a non-magnetic material such as, for example, wood or plastic, radial slot 20 of shielding element 18 is opened or remains open in a further method step 72. If the base is made of a ferromagnetic material or diamagnetic material such as, for example, iron, nickel, copper or aluminum, radial slot 20 of shielding element 18 is closed or remains closed in a further method step 70. After method steps 70 and 72, the method is then repeated at branch 68 until induction charging device 10 is deactivated.