• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: An electric hob having a low voltage range is provided to guarantee that electric leads are not overheated. CONSTITUTION: An electric hob having a low voltage range comprises a hob plate (1) materialized by a strong ceramic and a heating conductor(2) widely connected to the lower part of the hob plate. Each case, at least one lead element(12,13) having a resistance voltage between resistance voltages of the heating conductor and the related electric lead is interposed between the heating conductor and the electric lead.
    公开号:KR20000047736A
    申请号:KR1019990052954
    申请日:1999-11-26
    公开日:2000-07-25
    发明作者:알베르트 케르버
    申请人:추후제출；시세람 게엠베하；
    IPC主号:
    专利说明:

    Electric Hob
    The present invention relates to a low voltage range electric hob having a hob plate made of a strong ceramic and a heating conductor in contact with the lower side of the hob plate and a wide area.
    Hobs for typical household voltages of 110 V to 220 V are known from DE 297 02 813 U1. In particular, silicon nitrite or silicon carbite is called a strong ceramic for hob plates. At low temperatures in the range of 250 ° C., other electrically insulating ceramics such as aluminum oxide may also be used. Such strong ceramics are particularly suitable for use as hob plates because of their thermal conductivity, coefficient of thermal expansion, permissible surface deformation and electrical resistivity. The thermal conductivity of these materials is in the middle range between 5W / mK and 40W / mK. With these intermediate thermal conductivity values, it has been found that both thermal insulation to the housing and thermal conductivity to the heating elements can be compromised and effectively achieved. At the same time, the coefficient of thermal expansion of such strong ceramics is considerably low in the range of 10 −6 1 / K, thereby reducing the deformation and warping of the hob plates caused by different heating. The power set per unit area of the strong ceramic herein may be within the range of other strong hob plates between 4 W / cm 2 and 16 W / cm 2. Since the electrical resistivity of some strong ceramics is considerably high in the range of 10 13 ohms / cm, the corresponding electrical heating conductor can be attached directly to the bottom of the hob plate.
    When such electric hobs are designed for the low voltage range, special problems arise in the power supply when significant high current is required to obtain the same heating power therein. When the hob is designed for a 12V car battery, for example, about 80A of current flows in the lead, while only a few amps of current are generated inside. High current can heat the power leads in an undesirable manner. On the other hand, if the resistance of the power leads is kept particularly low, they also generally have good thermal conductivity and there is a risk of heat passing from the hob plate to the power leads in turn in an undesired manner.
    Therefore, it is an object of the present invention to provide an electric hob for the low voltage range which ensures that the power leads are not overheated.
    This object is solved by the features of claim 1. In the solution according to the invention, at least one lead element is inserted between the heating conductor and the power lead which in each case has a resistance value between the resistance values of the power lead associated with the heating conductor.
    Here, the present invention is based on the fact that another lead element between the heating conductor and the associated power lead can be inserted so that both heat conduction from the heating conductor and heating of the associated lead element can be possible. If the power lead is directly connected to the heating conductor, the risk of heating the power lead due to the high current is eliminated. However, heating of the heating conductor occurs due to the high thermal conductivity of the power leads. In contrast, when the lead element is located between the heating conductor and the associated power lead in accordance with the invention, this lead element has a resistance value between the resistance value of the heating conductor and the associated power lead, and therefore, to the heating conductor due to the high current. Both heat conduction through the lead element and heating of the lead element can be limited.
    According to a preferred embodiment, the lead element is composed of a heating conductor portion which is farther from the lower surface of the hob plate and has a larger cross section than the heating conductor which contacts the hob plate in a wide area. In this way, it is ensured that no additional contact resistance occurs between the lead element and the heating conductor. At the same time, particularly low cost design of the lead element is possible when the lead element can be formed from the material of the heating conductor already available. Here, it has been known that excessive heating of the lead element can already be avoided when the cross section of the lead element is four times the cross section of the heating conductor in contact with the hob plate in a large area.
    Another problem is the connection of lead elements to the associated power leads, and the contact resistance between the lead elements and the power leads must be prevented from rising in such a way that they are heated to considerably high temperatures due to the high current at the point of contact. According to a preferred embodiment, in the almost resistanceless connection between at least one lead element and the power lead, a copper block is provided on an associated lead end located over the area. A large area in contact with the lead element or associated power lead can be made from the side surface of the copper block, so that contact resistance from the lead element to the copper block or from the power lead to the copper block can be reduced to a minimum. In addition, the volume resistivity of the copper block is also quite low so that any heating due to the connection between the lead element and the power line can be excluded.
    According to another preferred embodiment, the hob plate is made of silicon nightlight, silicon carbide or aluminum nightlight. These ceramics have the advantages of the above-mentioned strong ceramics.
    Various designs regarding heating conductor formation can be considered. The invention according to the invention with an inserted lead element is particularly simple since the heating conductor consists of a metal foil compressed on the lower surface of the hob plate by an insulating film. Here, the curved shape of the heating conductor can be formed by heating the conductor cut off from the metal foil using a suitable cutting device, such as a laser cutting device. The corresponding lead element for supplying power to the heating conductor can be cut here in one and the same process.
    Another possibility of heating conductor formation is to apply a resistive film to the lower surface of the hob plate by thick film technology or thin film technology. In addition, a flame spraying process may also be used that can be applied with an interlayer of a material that acts as an adhesive and / or an electrical insulator. For example, aluminum oxide can be sprayed as an electrical insulator, which is essential, especially when electrically conductive strong ceramics such as silicon carbide are used.
    Another possibility is to attach the heating conductor to the lower surface of the hob plate in the form of a resist paste. Here, it is called PTC characteristic, and especially the resistance paste or heating resistance which has the positive temperature characteristic of resistance is suitable. The PTC characteristic causes the resistance of the associated heating resistor to suddenly increase when a certain temperature is reached, so that the temperature or power implemented within the heating resistor in this range is constant. Preferably, the corresponding jump temperature of the heating resistor is set here to the maximum temperature of the hob plate.
    According to another preferred embodiment, an insulating film is provided which is compressed against the bottom surface of the hob plate by the compression plate. In this way, the insulating film does not need to have any self metal stability, so various insulating materials can be used. In order to move the lead element to the heating conductor located on the lower surface of the hob plate, a path corresponding to the insulating film and the compression plate is provided.
    According to another preferred embodiment, the temperature sensor can be installed in the form of a resistance thermometer in direct contact with the ceramic plate to regulate the temperature on the ceramic plate. In this way, effective overheat protection can additionally be provided.
    1 is a cross-sectional view of an electric hob for a low voltage range according to the present invention.
    Further advantages and details of the invention are explained in more detail by the embodiments shown in the drawings. The figure constructed in one form shows a cross section of an electric hob for the low voltage range according to the invention. The hob plate 1 of the hob is composed of a round silicon nitrite disc. On the outer edge, the silicon nitrite disc has a chamber 10 compressed against the corresponding edge 11 of the housing wall 7. The hob plate 1 is here held by a compression surface 4 supported on the housing floor 8 by screws 9. The insulating layer 3 is located between the compression plate 4 and the hob plate 1. In order to heat the hob plate, a curved heating conductor in the form of a metal foil is introduced between the insulating film and the hob plate. Paths 14 and 15 for the power source are provided, respectively, passing through the insulating plate 3 and the compression plate 4 at the middle and the edge of the hob plate through which the lead ends 12 and 13 of the heating conductor pass. . Here, the ends 12, 13 have a cross sectional area four times the cross sectional area of the heating conductor 2. On the free end of the leads 12, 13, copper blocks 5, 6 are formed which form contact connections between the leads 12, 13 and the power leads. In order to better show the positions of the compression plate 4, the insulating film 3 and the heating conductor 2, the components in question are respectively shown to be spaced apart from each other at corresponding intervals, while in operation the individual elements are separated from each other. It is firmly in contact with a large area.
    The illustrated electric hob is preferably operated with a DC voltage of 12V and a current of 80A. The copper blocks 5, 6 can ensure that the contact resistance between the power leads and the free ends of the leads 12, 13 can be neglected so that unwanted heating at this point does not occur. Since the leads 12 and 13 are four times the area of the cross section of the actual heating conductor path 2, only 4/1 of the power is applied across the same length of the heating conductor portion with respect to the same lead length of the lead. In this way, it is ensured that the leads 12, 13 are not heated in an undesirable way. At the same time, however, the leads 12, 13 still have sufficiently high thermal resistance, so that any overheating of the copper block 5, 6 or the power line by the heating conductor is prevented.
    An electric hob for a low voltage range in which the power lead is not excessively heated, wherein at least one lead element having a resistance between the heating conductor and the resistance of the power lead associated with the heating conductor is inserted between the heating conductor and the power lead so that the power lead in the hob plate To prevent thermal conduction of the furnace.
    权利要求:
    Claims (11)
    [1" claim-type="Currently amended] An electric hob for a low voltage range having a hob plate made of a strong ceramic and a heating conductor in contact with the lower surface of the hob plate in a wide area,
    In each case between the heating conductor and the power lead an electrical hob having at least one lead element having a resistance value between the resistance of the heating conductor and the associated power lead.
    [2" claim-type="Currently amended] 2. The electric hob of claim 1, wherein said lead element is comprised of a portion of a heating conductor spaced apart from a lower surface of the hob plate and having a wider cross section than a heating conductor in contact with the hob plate in a wide area.
    [3" claim-type="Currently amended] 3. The electric hob according to claim 2, wherein the cross section of the lead element is four times the cross section of the heating conductor in contact with the hob plate in a large area.
    [4" claim-type="Currently amended] 4. A copper block according to any one of claims 1 to 3, wherein a copper block is installed on the associated lead end attached over the area for a nearly resistanceless connection between the at least one lead element and the power lead. Electric hob made.
    [5" claim-type="Currently amended] 5. The electric hob of claim 1, wherein the hob plate is comprised of silicon nitrite, silicon carbide or aluminum nitrite. 6.
    [6" claim-type="Currently amended] The electric hob according to any one of claims 1 to 5, wherein the heating conductor is composed of a metal film deposited on the lower surface of the hob plate.
    [7" claim-type="Currently amended] 6. The electric hob of any one of claims 1 to 5, wherein the heating conductor is composed of a metal foil compressed by an insulating film onto the lower surface of the hob plate.
    [8" claim-type="Currently amended] The electric hob according to any one of claims 1 to 5, wherein the heating conductor is composed of a resistance paste attached directly to a lower surface of the hob plate or using an adhesive.
    [9" claim-type="Currently amended] The electric hob according to any one of claims 1 to 8, wherein an insulating film compressed by a compression plate is provided with respect to the lower surface of the hob plate.
    [10" claim-type="Currently amended] 10. The electric hob of claim 9, wherein a path is provided in the insulating plate and the compression plate through which the lead end of the heating conductor passes.
    [11" claim-type="Currently amended] The hob plate according to any one of claims 1 to 10, wherein a temperature sensor is provided in direct contact with the ceramic plate connected to the regulating device for temperature control of the ceramic plate.
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    同族专利:
    公开号 | 公开日
    EP1006755A3|2002-01-23|
    AU5961999A|2001-06-21|
    DE19855481A1|2000-06-08|
    CA2291381A1|2000-06-01|
    JP2000188174A|2000-07-04|
    EP1006755A2|2000-06-07|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1998-12-01|Priority to DE1998155481
    1998-12-01|Priority to DE19855481.8
    1999-11-26|Application filed by 추후제출, 시세람 게엠베하
    2000-07-25|Publication of KR20000047736A
    优先权:
    申请号 | 申请日 | 专利标题
    DE1998155481|DE19855481A1|1998-12-01|1998-12-01|Electric cooktop|
    DE19855481.8|1998-12-01|
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