Induction HOB with a cooling arrangement having an angled fan connection

Abstract

The invention relates to an induction hob comprising a housing (10) having a flat bottom plate (13); a circuit board (20) provided on the bottom plate (13) having a high-temperature region (22) where electronic components are disposed; and a first axial fan (30) provided on the bottom plate (13) adjacent to the circuit board (20). In the induction hob, the first axial fan (30) is mounted such that it provides an inclination angle (a) relative to the bottom plate (13) in the direction of the circuit board (20).

Description

[0001] SPECIFICATION

[0002] INDUCTION HOB WITH A COOLING ARRANGEMENT HAVING AN ANGLED FAN CONNECTION

[0003] TECHNICAL FIELD

[0004] The present invention relates to an induction hob with a cooling arrangement, and more particularly to an induction hob equipped with a fan for cooling the coil.

[0005] BACKGROUND ART

[0006] In induction hobs that employ induction heating, the electronic board — which includes the induction coil and electronic components such as IGBTs — heats up during operation. In such cases, radial fans are used to cool the electronic board. Although a radial fan provides the desired efficiency for localized cooling, it may be insufficient for cooling all components in hobs having multiple heaters.

[0007] WO2021112776A1 discloses an induction hob with a cooling device comprising a casing; an induction element connected to an electronic device disposed on a lower sheet of the casing; a magnetic permeable planar top plate covers top of the casing such that confine an air duct with a predetermined channel height under a magnetic field distance providing a cooking operation with the induction element. The cooling device is having an axial fan arranged on the lower sheet of the casing such that rotational speed create an air flow path inside the air duct directly hit the top plate from the lower sheet in order to manipulate the air through the induction element when the axial fan is energized.

[0008] BRIEF SUMMARY OF THE INVENTION

[0009] The object of the invention is to increase the cooling efficiency in an induction hob having a cooling arrangement with an axial fan.

[0010] In order to achieve this object, the invention relates to an induction hob comprising: a housing having a flat bottom plate; a circuit board provided on the bottom plate and having a high-temperature region where electronic components are disposed; and a first axial fan provided on the bottom plate adjacent to the circuit board. In the induction hob, the first axial fan is mounted so as to provide an inclined angle relative to the bottom plate in the direction of the circuit board. In this way, the cooling air generated by the axial fan forms a flow profile with a vector directed toward the circuit board, thereby increasing the cooling efficiency. Moreover, since the axial fan produces less noise than a radial fan, a quieter cooking operation is achieved.

[0011] Preferably, a second axial fan is arranged opposite to the first axial fan and adjacent to the circuit board. The second axial fan increases the cooling air current generated by the first axial fan and further improves the cooling efficiency.

[0012] In a preferred embodiment, the second axial fan is arranged in mirror symmetry with respect to the circuit board axis relative to the first axial fan. Thus, the second axial fan also produces a cooling air flow with a vector directed toward the circuit board, and the two axial fans work together to provide efficient cooling.

[0013] Preferably, the first and second axial fans are aligned adjacent to the corresponding lower corners of the circuit board and a fixed heatsink extending along the full length is provided between them. The fixed heatsink passively cools the circuit board while also being cooled via heat transfer through the cooling air vectors directed toward the circuit board from the two axial fans.

[0014] Preferably, the fixed heatsink further includes a front wall erected on the bottom plate that forms, respectively, a first inlet and a second inlet at its opposite ends. These inlets partially direct the cooling air coming from the first and second axial fans. The front wall partially prevents the dispersion of the cooling air by channeling it along the wall toward the fixed heatsink, thereby increasing the cooling efficiency of the heatsink.

[0015] Preferably, the first and second axial fans are arranged on the same axis and include an identically structured rear axial fan pair arranged with an axial spacing between them. In this way, the circuit board is actively cooled from all four corners.

[0016] Preferably, each axial fan is provided with an induction coil mounted directly above it so that the cooling air generated by the corresponding axial fan passes directly through the coil. In this configuration, a single axial fan can simultaneously cool both the circuit board and the induction coil.

[0017] Preferably, the inclination angle is selected in the range of 1-45° such that when the cooling air from the first axial fan directly strikes the top plate, the reflected air is at least partially directed toward the high-temperature region. At these angles, the portion of the cooling air that impacts the top plate is deflected toward the circuit board. Consequently, a greater portion of the air produced by the axial fan reaches the circuit board — both directly and indirectly — thus increasing the cooling efficiency.

[0018] Preferably, the high-temperature region is provided at the center of the circuit board. In a dual-fan configuration where each axial fan is located on one side of the circuit board, the interference region of the cooling air produced by the two fans is formed at the center of the circuit board, thereby enhancing the cooling efficiency.

[0019] Preferably, an air inlet is provided in the bottom plate beneath the first axial fan. In this way, the axial fan draws ambient air largely directly from the air inlet on the bottom plate and directs it to the coil.

[0020] Preferably, an exhaust opening is provided in the lateral wall surrounding the bottom plate. The air flow generated by the axial fans is expelled from inside the housing to the outside through the lateral wall. Thus, for example, an integrated induction hob is provided with an air flow.

[0021] Preferably, an peripheral barrier encloses the first axial fan while leaving the portion facing the circuit board open. In this way, by preventing air from escaping laterally, an increase in the axial flow vector is achieved.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a perspective view of an induction hob with a fan-equipped cooling arrangement, with the top plate and coil removed.

[0024] Figure 2 is a perspective view of the induction hob of Figure 1 with the induction coil mounted.

[0025] Figure 3 is a transverse cross-sectional view of the induction hob with the fan-equipped cooling arrangement in operation.

[0026] Figure 4 is an enlarged transverse cross-sectional view of a single cooling fan as shown in Figure 3. DETAILED DESCRIPTION OF THE INVENTION

[0027] In the following detailed description, the present invention is explained by way of examples solely for the purpose of illustrating the subject matter and not to impose any limitations.

[0028] In Figure 1 , an integrated induction hob is shown in perspective with its tempered glass top plate removed. A metal housing (10) has a flat, flat bottom plate (13) and a tray-like structure formed by flat lateral walls (11) rising from its peripheral edges. On one of these lateral walls, a grill-type exhaust opening (12) is provided. Additionally, an air inlet (14) in the form of a perforation is provided on the bottom plate (13).

[0029] A circuit board (20) in the form of a PCB is centrally aligned on the bottom plate (13) and includes a high-temperature region (22) where an IGBT circuit is located. In correspondence with each corner of the circuit board (20), a first axial fan (30) and a second axial fan (40) are arranged in the front corners, and a rear axial fan pair (60) is arranged in the rear corners. The axial fans (30, 40, 60) are of identical structure.

[0030] The first and second axial fans (30, 40) each comprise a propeller (34, 44) provided with a predetermined spacing over the air inlet (14) on the bottom plate (13) and a fan base (33 and 43, respectively) onto which they are mounted. A strip-shaped peripheral barrier (32, 42) is erected on the bottom plate (13) so that the portions of the fans (30, 40, 60) facing the circuit board (20) remain uncovered. The peripheral barriers (32, 42) of the first (30) and second (40) axial fans face each other with an opening, and their radial width is set to be less than 90° (for example, 45°). The outlets of the barriers (32, 42) open into a fixed heatsink (50) via a corresponding first inlet (52) and second inlet (58).

[0031] The fixed heatsink (50) comprises an aluminum cooling block (54) with laterally extending fins, which provides passive cooling. The cooling block (54) extends along the front edge of the circuit board (20). The laterally extending, spaced fin-like portions of the cooling block (54) form sequential air passage corridors between the first (52) and second (58) inlets. A front wall (56) is integrally formed at the ends with the peripheral barriers (32, 42). Each fan base (33, 43) is fixed such that one end rests on the upper edge of the corresponding peripheral barrier (32, 42). The motors of the axial fans (30, 40, 60) are arranged to extend at the center of the respective fan bases. As shown in Figure 2, an induction coil (70) having a grill-like structure is mounted on each of the axial fans (30, 40, 60). The induction coil (70) extends parallel to the bottom plate (13). In Figure 3, a transverse cross-sectional view of the induction hob is shown. As seen here, the top plate (80) and its inner wall (82) are planar and are spaced apart from and parallel to the bottom plate (13). The first and second fans (30, 40) are arranged in an inclined orientation toward each other. Similarly, the rear axial fan pair (60) is also inclined toward each other. To achieve this, the fan bases (33, 43) of the first and second axial fans (30, 40) are mounted on the peripheral barriers (32, 42) with an inclination toward each other.

[0032] Thus, when the induction coil (70) heats up, the cooling arrangement is activated, and the axial fans (30, 40, 60) are driven so that the inclined first and second axial fans (30, 40) (or the rear fan pair (60)) produce a cooling air flow that forms an interference pattern. This interference pattern is generated when the cooling air, blown in the axial direction by the inclined fans, first strikes the inner wall (82) at an angle, is partially reflected, and is then focused onto the high-temperature region (22) located at the center of the circuit board (20). In the high-temperature region (22), the cooling air reflected from the inner wall (82) interferes, resulting in a denser air flow compared to other regions. In this manner, a high air flow rate is achieved in the high-temperature region (22), while lower air flow rates occur in other areas of the circuit board (20). Surprisingly, it has been found that the turbulence created by this interference pattern significantly increases the cooling efficiency in the high- temperature region (22).

[0033] The peripheral barriers (32, 42) of the first and second fans (30, 40) are designed so that their outer edges are higher than their inner edges. Moreover, the lower edges of the peripheral barriers (32, 42) are shaped with an inclination corresponding to that of the fan propellers (34, 44). In this way, the surface area of the air inlet openings of the first and second axial fans (30, 40) is increased.

[0034] As shown in Figure 4, the inclination angle (a) of the first axial fan (30) is selected as 20°. It has been observed that even at this angle, during normal operating speeds, the rotation of the propeller (34) of the first axial fan (30) generates a cooling air flow that passes through the adjacent first inlet (52) and sufficiently cools the cooling block (54). In order to reduce the area and increase the flow velocity, a step (35) is provided on the portion of the peripheral barrier (32) facing the first inlet (52), and the remainder of the area behind the front wall (56) is raised. The same applies in mirror symmetry for the second axial fan (40), and as mentioned, the rear axial fan pair (60) is also of a similar structure to the first and second axial fan pair (30, 40). Thus, within the cooling chamber between the housing (10) and the top plate (80), the first axial fan (30) alone is capable of providing a cooling air flow rate profile sufficient to cool the coil (70) mounted above it, to direct and reflect air at an inclined angle onto the inner wall (82) thereby targeting the high-temperature region (22), and simultaneously to cool the fixed heatsink (50).

[0035] REFERENCE NUMERALS

[0036] 10 Housing

[0037] 11 Lateral wall

[0038] 12 Exhaust opening

[0039] 13 Bottom plate

[0040] 14 Air inlet

[0041] 20 Circuit board

[0042] 22 High-temperature regions

[0043] 30 First axial fan

[0044] 32 Peripheral barrier

[0045] 33 Fan base

[0046] 34 Propeller

[0047] 35 Step

[0048] 40 Second axial fan

[0049] 42 Peripheral barrier

[0050] 43 Fan base

[0051] 44 Propeller

[0052] 50 Fixed heatsink

[0053] 52 First inlet

[0054] 54 Cooling block

[0055] 56 Front wall

[0056] 58 Second inlet

[0057] 60 Rear axial fan pair

[0058] 70 Coil

[0059] 80 Top plate a Inclination angle 82 Inner wall

Claims

CLAIMS1. An induction hob comprising, a housing (10) having a flat bottom plate (13); a circuit board (20) provided on the bottom plate (13), the circuit board having a high-temperature region (22) where electronic components are disposed; and a first axial fan (30) provided on the bottom plate (13) adjacent to the circuit board (20) characterized in that the first axial fan (30) is mounted to provide an inclination angle (a) relative to the bottom plate (13) in the direction of the circuit board (20).

2. An induction hob according to Claim 1 , wherein a second axial fan (40) is arranged in a direction opposite to the first axial fan (30) and adjacent to the circuit board (20).

3. An induction hob according to Claim 2, wherein the second axial fan (40) is arranged in mirror symmetry with respect to the circuit board (20) axis relative to the first axial fan (30).

4. An induction hob according to any one of Claims 2-3, wherein the first and second axial fans (30, 40) are aligned adjacent to the corresponding lower corners of the circuit board (20) and a fixed heatsink (50) extending along the entire length is provided between them.

5. An induction hob according to Claim 4, wherein the fixed heatsink (50) comprises a front wall (56) erected on the bottom plate (13) and configured to form, respectively, a first inlet (52) and a second inlet (58) which partially direct the cooling air coming from the first and second axial fans (30, 40).

6. An induction hob according to any one of Claims 2-5, wherein the first and second axial fans (30, 40) are arranged on the same axis and a rear axial fan pair (60) of identical structure with an axial spacing between them is provided.

7. An induction hob according to Claim 6, wherein each axial fan (30, 40, 60) is provided with an induction coil (70) mounted directly above it, through which the cooling air generated by the corresponding axial fan (30, 40, 60) passes directly.

8. An induction hob according to any one of the preceding claims, wherein the inclination angle (a) is selected in the range of 1-45° such that when the cooling air blown by the first axial fan (30) directly strikes the top plate (80), the reflected air is at least partially directed to the high-temperature region (22).

9. An induction hob according to any one of the preceding claims, wherein the high- temperature region (22) is provided at the center of the circuit board (20).

10. An induction hob according to any one of the preceding claims, wherein the bottom plate (13) includes an air inlet (14) provided beneath the first axial fan (30).

11. An induction hob according to Claim 10, wherein an exhaust opening (12) is provided on the lateral wall (11 ) that surrounds the bottom plate (13).

12. An induction hob according to any one of the preceding claims, wherein it includes an peripheral barrier (32) which encloses the first axial fan (30) while leaving the portion facing the circuit board (20) open.

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