Wireless charging device used in vehicle

Abstract

A wireless charging device for a vehicle is provided, comprising: a housing formed of a first plate having a cooling channel formed therein and a second plate having a coil mounting portion installed therein; a ferrite unit installed between the first plate and the second plate to generate a magnetic field; and a coil portion seated on the coil mounting portion to convert the magnetic field into power; wherein the ferrite unit comprises a ferrite guide having a ferrite receiving portion formed therein; and a ferrite seated on the ferrite receiving portion; and wherein a pattern including a concave portion is formed on the surface of the ferrite that contacts the ferrite receiving portion. Accordingly, there is an advantage that the rate of change of inductance can be minimized even while reducing the weight of the ferrite.

Description

Technology Field

[0001] The present invention relates to a wireless charging device, and more specifically, to a wireless charging device for a vehicle that is installed on the underside of a vehicle and can receive power wirelessly from an external source. Background Technology

[0002] Unless otherwise indicated in this specification, the contents described in this identification item are not prior art for the claims of this application, and are not recognized as prior art simply because they are described in this identification item.

[0003] Eco-friendly vehicles powered by electricity, such as electric vehicles and hybrids, are equipped with rechargeable batteries capable of repeated charging to supply power. As these batteries gradually discharge while the vehicle is in operation, they are recharged using a separate charging device. However, since connecting a separate charging device presents the inconvenience of requiring the user to manually connect the vehicle to the device, active research is currently being conducted on charging vehicles using wireless charging systems.

[0004] In this case, the wireless charging system consists of a transmitter that converts external AC power into an RF signal and a wireless charging device installed in the vehicle that receives the RF signal wirelessly using electromagnetic induction and converts it into power to charge the vehicle battery, thereby enabling the driver to wirelessly charge the rechargeable battery inside the vehicle in a simple and convenient manner. Specifically, the wireless charging device is formed by a ferrite unit that receives the RF signal from the transmitter and generates a magnetic field, a coil unit that converts the magnetic field into power, and a housing in which the ferrite unit and the coil unit are installed internally and which is equipped with a cooling channel.

[0005] These wireless charging devices are considerably heavy, and there is an urgent need for weight reduction to increase vehicle operating efficiency. Prior art literature

[0006] 1. Korean Patent Publication No. 10-2023-0020458 (February 10, 2023) The problem to be solved

[0007] The embodiment of the present invention is devised to solve the above-mentioned problems and aims to provide a wireless charging device for vehicles that minimizes the reduction in wireless charging efficiency while reducing weight. means of solving the problem

[0008] An embodiment of the present invention provides a wireless charging device for a vehicle, comprising: a housing formed of a first plate having a cooling channel formed therein and a second plate having a coil mounting portion installed therein, to solve the above-mentioned problem; a ferrite unit installed between the first plate and the second plate to generate a magnetic field; and a coil portion seated on the coil mounting portion to convert the magnetic field into power; wherein the ferrite unit comprises a ferrite guide having a ferrite receiving portion formed therein; and a ferrite seated on the ferrite receiving portion; and wherein a pattern including a concave portion is formed on the surface of the ferrite that contacts the ferrite receiving portion.

[0009] It is preferable that the above-mentioned concave portion is formed in a shape where multiple straight lines intersect each other, so that the pattern is formed in a grid shape.

[0010] The ferrite is formed in a rectangular shape, and it is effective for the concave portion to be formed as a straight line inclined to the corner of the ferrite.

[0011] It is preferable that the above-mentioned concave portion be formed at a 45-degree angle to the edge of the ferrite.

[0012] It is effective for the weight reduction rate reduced by the above-mentioned concave portion to be 15.0% to 20.9%. Effects of the invention

[0013] According to the means for solving the problem of the present invention as described above, various effects including the following can be expected. However, the present invention is not required to exhibit all of the following effects to be valid.

[0014] One embodiment of the present invention has the advantage of being able to minimize the rate of change of inductance while reducing the weight of the ferrite of a conventional vehicle wireless charging device.

[0015] In addition, by providing a concave portion, the bonding area between the ferrite and the ferrite guide can be increased, thereby increasing structural stability. Brief explanation of the drawing

[0016] FIG. 1 is a perspective view of a wireless charging device according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of FIG. 1. FIG. 3 is a perspective view of FIG. 2 from a different direction. FIG. 4 is an exploded view of the ferrite unit of FIG. 3. FIG. 5 is a bottom view of FIG. 4 FIG. 6 is a cross-sectional view along the cutting line VI-VI of FIG. 5. FIG. 7 is a partial enlarged plan view of the ferrite of FIG. 5. FIG. 8 is a cross-sectional view along the cutting line VIII-VIII of FIG. 7. Specific details for implementing the invention

[0017] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

[0018] FIG. 1 is a perspective view of a wireless charging device according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, FIG. 3 is a perspective view of FIG. 2 in a different direction, FIG. 4 is an exploded perspective view of the ferrite unit of FIG. 3, FIG. 5 is a bottom view of FIG. 4, FIG. 6 is a cross-sectional view along the cutting line VI-VI of FIG. 5, FIG. 7 is a partially enlarged plan view of the ferrite of FIG. 5, and FIG. 8 is a cross-sectional view along the cutting line VIII-VIII of FIG. 7.

[0019] Referring to FIGS. 1 to 8, a wireless charging device (10) of an embodiment of the present invention comprises a housing (100) formed by a first plate (110) having a cooling channel (1111) formed therein and a second plate (130) having a coil mounting portion (132) installed therein, a ferrite unit (200) formed between the first plate (110) and the second plate (130) to generate a magnetic field, and a coil portion (not shown) seated on the coil mounting portion (132) to convert the magnetic field into power. The ferrite unit (200) comprises a ferrite guide (210) having a ferrite receiving portion (211) formed therein and a ferrite (240) seated on the ferrite receiving portion (211), a first circuit portion (220) coupled and fixed to one side of the ferrite guide (210) to receive and rectify power from the coil portion, and the other side of the ferrite guide (210). It includes a second circuit unit (230) that is coupled and fixed to the side and detects the position of the magnetic part.

[0020] A wireless charging device (10) refers to a device installed in an electric vehicle that receives power to wirelessly charge the battery of the electric vehicle through interaction with an external charging device.

[0021] The housing (100) is connected in a state facing each other with a first plate (110) having a cooling channel (1111) formed therein and a second plate (130) having a coil mounting part (132) installed therein, and accommodates a ferrite unit (200) and a coil part (300) related to wireless charging inside.

[0022] The first plate (110) is formed with a flow path (111) that discharges heat generated from the coil and ferrite unit (200) during vehicle charging into the coolant, and a coupling part (112) that guides the assembly position by combining with a second guide projection (13212) protruding from the second plate (130). At this time, since a configuration that generates a magnetic field and power is accommodated on the inner side of the housing (100), the flow path (111) is formed with a cooling passage (1111) formed as a recess on the inner side of the first plate (110), that is, on the surface not facing the second plate (130), and a flow path cover (1112) that covers and seals the outer side of the cooling passage (1111).

[0023] The coupling portion (112) is formed corresponding to the position of the second guide projection (13212). At this time, a coupling hole (1121) is formed so that the second guide projection (13212) can be visually identified from the outside of the first plate (110) to facilitate easy coupling between the second guide projection (13212) and the coupling hole (1121) by the operator. Additionally, a coupling cover (1122) is installed on the outside of the coupling hole (1121) to prevent foreign substances, such as moisture, from entering through the coupling hole (1121).

[0024] The second plate (130) is formed with a plate body (131) connected to the first plate (110) to form a housing (100), and a coil mounting part (132) installed on one side of the plate body (131), so that the coil is stably installed at a pre-designed location. At this time, to improve the workability of the operator, an installation hole (1311) is formed in the plate body (131) at the location where the coil mounting part (132) is installed, and the coil mounting part (132) is installed in the installation hole (1311) and then firmly fixed by a fastening member. Accordingly, the coil mounting part (132) is formed in various ways depending on the capacity of the vehicle battery or the charging method, etc., thereby providing various wireless charging devices (10) according to the design, reducing product research costs and improving the versatility of the product.

[0025] The coil mounting portion (132) is formed with an installation portion (1321) having first and second guide protrusions, a winding rib (1322) on which the coil portion is wound, and an extension portion (1323) formed by extending outward from the winding rib (1322), thereby stably fixing the coil portion (300) and maintaining a constant relative position between the coil portion (300) and the ferrite unit (200). The installation portion (1321) is formed to have a certain flat cross-section in the central part of the coil mounting portion (132), and is formed with a first guide protrusion (13211) that protrudes and is inserted and fixed into a part of the guide hole of the second circuit portion (230), and a second guide protrusion (13212) that is inserted and fixed into the coupling hole (1121).

[0026] The winding rib (1322) rotates outward from one side of the installation part (1311) and extends outward to form a vortex-like shape, allowing the coil portion to be wound between adjacent winding ribs (1322) and stably fixed. At this time, it is preferable that the winding rib (1322) not protrude outward when the coil portion is wound, and has the same height as the installation part (1321) so that the ferrite unit (200) is stably supported on the upper side of the winding rib (1322).

[0027] The extension section (1323) is configured such that a plurality of extension ribs (13231) are arranged at regular intervals on the outside of the winding ribs (1322) to form a void section (13233) between adjacent extension ribs (13231), thereby securing a space for installing cables, etc., while allowing heat generated in the coil section to be smoothly discharged through the extension ribs (13231).

[0028] At this time, the extension rib (13231) is formed to be longer than the installation part (1311) and the winding rib (1322), and a connecting rib (13232) that connects multiple extension ribs (13231) from the inside is further formed to wrap around the outside while the ferrite unit (200) is seated on the coil mounting part (132), thereby improving the fixing force and stability of the ferrite unit (200) and increasing the effect of improving the durability and reliability of the product.

[0029] The ferrite guide (210) is formed with a plurality of rectangular ferrite receiving portions (211) on its upper surface, and guide ribs (212) are formed protruding from the outer surface of each ferrite receiving portion (211) to surround the side of the ferrite (240).

[0030] The ferrite (240) is formed in a rectangular shape to be fitted into the ferrite receiving portion (211), and a pattern (242) including a concave portion (241) is formed on the surface of the ferrite (240) that faces the ferrite receiving portion (211). Preferably, the concave portion (241) and the pattern (242) are formed on both the upper and lower surfaces of the ferrite (240). The concave portion (241) is formed in a shape where a plurality of straight lines intersect each other, so that the pattern (242) is formed in a grid shape, and the concave portion (241) is formed as a straight line inclined at the corner of the ferrite (240). More preferably, the concave portion (241) is formed at a 45-degree angle to the corner of the ferrite (240). An adhesive (221) is filled between the ferrite guide (210) and the ferrite (240).

[0031] As a plurality of concave portions (241) are formed in the ferrite (240), as shown in FIG. 8, the adhesive (221) is filled into the concave portions (241), thereby increasing the bonding area of ​​the adhesive and increasing the adhesive strength.

[0032] Typically, there is a trade-off relationship between the weight of the ferrite (240) and the inductance value of the wireless charging device, and it is necessary to minimize the change in the inductance value (less than 1% of the conventional value) even while reducing the weight of the ferrite. That is, if the inductance value changes in the conventional wireless power transmission system, the existing matching circuit does not match, and the charging performance changes significantly. Therefore, it is necessary to minimize the change in the charging performance of the conventional wireless power transmission system by minimizing the rate of change in inductance to within 1.0% compared to the conventional structure while reducing weight.

[0033] First, it was confirmed that the weight reduction effect is maximized when the same pattern is used at a 45-degree inclination of the concave portion (241) at the corner of the ferrite (240). In addition, the inductance change rate according to the width (w), depth (d), and separation distance (b) of the concave portion (241) shown in FIGS. 7 and FIGS. 8, and the thickness (t) of the ferrite (240) was measured, and the result was as shown in [Table 1] below.

[0034] Ferrite thickness (t) [mm] 5 5 5 5 5 5 Separation distance (b) [mm] 12 12 12 12 10 17 Depth of indentation (d) [mm] 1.5 1.5 1.5 1.5 1.5 1.5 Concave width (w) [mm] 1.6 1.8 2 2.3 1.6 2.3 d*w / (t*b) 0.04 0.05 0.05 0.06 0.05 0.04 Inductance [μH] 104.06 103.98 103.97 103.75 103.8 104 Inductance change rate[%] 0.7 0.8 0.9 1 1 0.8 Weight reduction rate[%] 15 16.7 17.6 20.9 17.7 15.1

[0035] Looking at the results in [Table 1], it can be confirmed that the rate of change of inductance is within 1%. That is, the rate of change of inductance can be minimized within the range of 15.0% to 20.9% of the weight reduction rate by the concave portion (241), and the rate of change of inductance can also be minimized within the range satisfying [Equation 1] below.

[0036] [Mathematical Formula 1]

[0037] 0.04≤d*w / (t*b)≤0.06

[0038] As described above, one embodiment of the present invention has the advantage of being able to minimize the rate of change of inductance while reducing the weight of the ferrite of a conventional vehicle wireless charging device.

[0039] In addition, by providing a concave portion, the bonding area between the ferrite and the ferrite guide can be increased, thereby increasing structural stability.

[0040] Although preferred embodiments of the present invention have been described illustratively above, the scope of the present invention is not limited to such specific embodiments and can be appropriately modified within the scope described in the claims. Explanation of the symbols

[0041] 110: 1st Plate 130: 2nd Plate 132: Coil mounting section 200: Ferrite unit 211: Ferrite receiving section 240: Ferrite 241: Concave area 242: Pattern

Claims

Claim 1 A housing (100) formed by a first plate (110) having a cooling channel formed therein and a second plate (130) having a coil mounting portion (132) installed therein; a ferrite unit (200) installed between the first plate (110) and the second plate (130) to generate a magnetic field; and a coil portion seated on the coil mounting portion (132) to convert the magnetic field into power; wherein the ferrite unit (200) comprises a ferrite guide (210) having a ferrite receiving portion (211) formed therein; A wireless charging device for a vehicle, comprising: a ferrite (240) seated in the ferrite receiving portion (211); wherein a pattern (242) including a concave portion (241) is formed on the surface of the ferrite (240) facing the ferrite receiving portion (211); and wherein an adhesive (221) is filled between the ferrite guide (210) and the ferrite (240), and the adhesive (221) is filled into the concave portion (241) to form a bonding area of ​​the adhesive. Claim 2 A wireless charging device for a vehicle according to claim 1, characterized in that the concave portion (241) is formed in a shape where a plurality of straight lines intersect each other, and the pattern (242) is formed in a grid shape. Claim 3 A wireless charging device for a vehicle according to claim 2, wherein the ferrite (240) is formed in a rectangular shape and the concave portion (241) is formed as a straight line inclined at the corner of the ferrite (240). Claim 4 A wireless charging device for a vehicle according to claim 3, characterized in that the concave portion (241) is formed to be inclined at a 45-degree angle to the edge of the ferrite (240). Claim 5 A wireless charging device for a vehicle, characterized in that, in any one of claims 1 to 4, the weight reduction rate reduced by the concave portion (241) is 15.0% to 20.9%. Claim 6 A wireless charging device for a vehicle according to any one of claims 1 to 4, characterized in that the width (w), depth (d), and separation distance (b) of the concave portion (241) and the thickness (t) of the ferrite (240) satisfy the range [Equation 1] below. [Equation 1] 0.04 ≤ d*w / (t*b) ≤ 0.06

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