JP2010113803A - Heating method using conductive ceramic layer and engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating method for an engine and the like capable of easily starting an engine by heating a cylinder liner and an oil pan mechanism. <P>SOLUTION: A first ceramic layer C1 formed of an electric insulating ceramic layer and a second ceramic layer C2 formed of a conductive ceramic layer on an upper surface of the first ceramic layer C1 are provided by plasma spraying on a metallic article. Further, at both ends of the second ceramic layer C2, power-feeding wires 4 are arranged, and the second ceramic layer C2 is made to be a heat generating body by supplying power between both power-feeding wires 4 wherein the first ceramic layer C1 is used as a heat induction layer. Then, the cylinder liner 2 and the oil pan mechanism 3 can be heated with the ceramic layer as an heat generating body in the heating method. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides an ultra-thin heating element by forming a multilayer ceramic layer having a two-layer structure of an electrically insulating ceramic layer and a conductive ceramic layer on the surface of an object to be heated of a metal article. The present invention relates to a heating method in which a ceramic layer is energized to generate heat and an engine using the same.

  In a general engine, a plurality of cylinder liners are fitted and fixed in the longitudinal direction of a cylinder block, and cooling water is supplied to a jacket provided surrounding the cylinder liner, so that the amount of heat received from combustion gas during engine operation is reduced. The engine oil (lubricating oil) is smoothly supplied to moving members such as pistons by removing the parts through cooling water, and the oil film is appropriately formed on the sliding parts of the moving members to reduce the frictional force of these members. I am trying.

  The engine oil that has lubricated each part of the engine is led and stored in an oil pan provided in an opening at the bottom of the cylinder block, and this is pressurized by an oil pump so that the sliding surface between the cylinder liner and the piston An oil circulation path is formed to supply the friction surface of the other movable member.

  As the engine oil, oil having a characteristic of having an appropriate viscosity at a predetermined temperature (for example, 80 to 95 ° C.) according to the output of the engine is used. However, when used in a low temperature, particularly in a cold region below 0 ° C., the viscosity becomes high and the viscosity becomes unsuitable as engine oil. As the engine is operated and the temperature rises, the viscosity gradually decreases, and has a characteristic of maintaining an appropriate viscosity at the predetermined temperature.

  Therefore, when the engine is stopped and in a cooled state, the engine oil film present in the friction part of this engine component is not formed and the viscosity is high. Since a large frictional force acts at the start of the engine, the starter is rotated for a long time or repeatedly operated. Further, even if the engine is operated, it is necessary to take a sufficient time for warm-up operation until the engine speed is stabilized and stabilized.

  Although this warm-up operation differs depending on the driver, it is usually performed for about 30 minutes, during which fuel is wasted, and at that time, a large amount of exhaust gas is released from the engine to improve fuel efficiency. Getting worse.

  As mentioned above, when the engine becomes cold, the viscosity of the engine oil increases and it is difficult to stabilize the engine in a normal state within a short period of time. A device has been proposed in which a circulation path for heated cooling water is provided in addition to a normal circulation path for cooling water so that engine oil can be indirectly heated by circulating water (radiator water) (Patent Document 1). ). Moreover, this patent document 1 also shows an apparatus for providing a hot water pipe line on the lower surface of the oil pan and supplying the heated cooling water thereto for heating.

  In general, the fuel supplied to the engine is about 20 to 30% used for traveling, and the remaining 80 to 70% is wasteful heat. That is, it is said that the total heat radiated from the radiator, the heat radiated from the oil pan, etc. is 35 to 45%, the mechanical loss is about 10%, and the rest is discarded by the exhaust gas.

  That is, the amount of heat generated by the combustion in the cylinder is released into the air by the radiator via the cooling water, and the exhaust gas having a high amount of heat is released into the air without being used as it is. Furthermore, although not discussed much, the oil pan occupies a considerable proportion of the surface area of the engine. Moreover, the oil pan is in a bare state that directly touches the outside air, and the inside thereof has a temperature of about 80 ° C. Since oil is accumulated, this oil pan also acts as a kind of heat radiator.

Although the temperature in the combustion chamber of the engine is related to the operating state, it is said to be a high temperature of 700 ° C. to 1000 ° C., and the exhaust gas is said to be about 600 ° C. However, the engine main body is maintained at about 80 ° C. by cooling water, and in this sense, the engine needs to operate as “a kind of heat retaining member”. Therefore, especially in the winter, it is inevitable that an oil pan that directly touches cold air forms a heat radiator that releases more heat than necessary, so there is no doubt that this is a considerable problem in improving fuel consumption.
JP-A-9-79020

  The invention described in Patent Document 1 supplies an oil cooler to an oil cooler in a state where the cooling water temperature is increased by switching the cooling water pipe when the temperature of the engine is low during cold weather. It is intended to reduce the viscosity by warming the passing engine oil.

  However, when the engine is started, the cooling water is not yet heated to become hot water, and the engine oil cannot be heated until the engine is driven for a while until the temperature becomes appropriate. Warm-up operation is required, and the time required for this operation and the fuel consumed during the operation are required, which does not save fuel costs.

  As described above, when the engine is stopped in winter or in a cold region, the cylinder and piston are in a cooled state and the viscosity of the engine oil is high. Therefore, if the cylinder and the oil pan can be heated when the engine is started, the engine can be easily started and the time required for the warm-up operation can be shortened.

  In addition, when an automobile travels, the oil pan is cooled more than necessary by the air. At such time, the oil pan becomes insulative and reduces heat dissipation. There is no doubt that it would be preferable to improve the fuel consumption if it was possible to drive in a state where the heat was stored.

  On the other hand, there is no space between the cylinder liner and the cylinder body in which an electrothermal heating device or the like can be installed, and it has not been proposed to provide a heating device on an oil pan or a layer made of a heat insulating material. Furthermore, even if a heater is actually provided in a cylinder liner or the like, there is no space for installing the heater, and an ultra-thin durable heater of 1 mm or less has not been proposed.

  The present inventor has been based on (1) ceramic layer and thermal conductivity, and (2) heat conductivity in the case where two or three different ceramic layers are laminated to form a laminated structure, depending on the type of ceramic to be laminated. It has been confirmed from numerous experiments that differences occur in heat transfer.

  The present invention was obtained as a result of studying application of this experimental result as a surface treatment material for engine members.

  That is, when a laminated ceramic layer composed of two types of ceramic layers is applied to the metal surface, the lower ceramic layer directly formed on the metal surface is used as the electrically insulating layer (first ceramic layer), and the conductive layer is formed thereon. An object of the present invention is to provide a heating method by thermally spraying a ceramic layer (second ceramic layer) and energizing and generating heat using the second ceramic layer as an electric resistance heating element.

  In addition, the present invention can form a very thin heating element by laminating two types of ceramic layers on the metal surface and energizing / heating the upper ceramic layer as a resistance heating element. And an electrothermal heating element that is resistant to vibration and impact.

  Furthermore, the present invention provides means for preventing unnecessary heat dissipation from an oil pan or the like by utilizing the special property of the ceramic layer having a laminated structure, that is, heat insulation or heat insulation.

  The heating method according to the present invention and the apparatus using the same for achieving the above object are configured as follows.

  1) Thermal spraying and laminating a first ceramic layer made of an electrically insulating ceramic layer on the surface of a metal article by plasma spraying, and a second ceramic layer made of a conductive ceramic layer on the upper surface of the first ceramic layer; Feeding wires are arranged at both ends of the second ceramic layer, and the metal article is heated by energizing between the electrode wires, using the second ceramic layer as a resistance heating element, and using the first ceramic layer as a heat induction layer. It is characterized by doing.

  2) In the second heating method, the first ceramic layer and the second ceramic layer are drawn in the relationship of “spectral radiant energy density / wavelength emitted from the ceramic layer” when heated to the same temperature. In the characteristic curves, compare the wavelengths at the peak values indicated by these curves, spray the long wavelength ceramic layer directly on the metal surface as the first ceramic layer, and use the short wavelength ceramic layer as the second ceramic layer. It is characterized by being thermally sprayed and laminated on the first ceramic layer.

  3) In the third heating method, the first ceramic layer is composed of aluminum oxide or a ceramic layer mainly composed of aluminum oxide, and the second ceramic layer is composed of titanium oxide or a ceramic layer mainly composed of titanium oxide. It is characterized by.

  4) According to a fourth aspect of the present invention, there is provided an electrically insulating first ceramic layer on one or both of a cylinder liner supported by a cylinder block of an engine and an oil pan disposed under the cylinder block. In addition, a conductive second ceramic layer is thermally spray-laminated on the surface of the first ceramic layer, and the cylinder liner and / or the oil pan are required at the initial stage of engine startup. The engine is configured to heat one or both of the cylinder liner and the oil pan by energizing and generating heat to the second ceramic layer for a short time.

  5) An engine according to a fifth invention is characterized in that the first ceramic layer is a ceramic layer mainly composed of aluminum oxide, and the second ceramic layer is titanium oxide.

  6) The engine heat dissipation preventive device according to the sixth aspect of the present invention is that a ceramic layer having a two-layer structure of an aluminum oxide layer and a titanium oxide layer is provided on the outer surface of an oil pan provided below the cylinder block of the engine. It is a feature.

  Regarding the order of stacking the two ceramic layers, the curve of “spectral radiant energy density (vertical axis) and radiation wavelength (horizontal axis)”, that is, the magnitude of radiant energy from the ceramic layer is This is based on the ceramic characteristics indicated by the “spectral radiation divergence curve” obtained from the “Planck radiation equation” determined only by “temperature” and “wavelength” or “wave number”.

  For example, when a bilayer ceramic layer is stacked on the surface of a metal article and the surface of the ceramic layer is exposed to a heat source, titanium oxide is stacked on the high temperature side and aluminum oxide is stacked on the metal article side. It means to give direction to the heat flow.

  Further, when heat is transferred from the inner surface to the outer surface side of the metal article, the ceramic layers laminated in the above order have a characteristic of exhibiting a “heat insulating effect or heat shielding effect”. While the titanium oxide layer on the heat source side (upper layer) and the aluminum oxide layer on the metal article side (lower layer) have the effect of positively receiving heat energy, It resists heat dissipation from the metal article side and has a function of exhibiting heat insulation or heat insulation.

  The present invention comprises laminating a first ceramic layer made of an electrically insulating ceramic layer by plasma spraying on the surface of a metal article, and a second ceramic layer made of a conductive ceramic layer on the upper surface of the first ceramic layer, A power supply is arranged at both ends of the second ceramic layer, energized between both power supply lines, and the metal article is heated using the second ceramic layer as a heating element and the first ceramic layer as a heat induction layer. It is characterized by that.

  As the electrically insulating ceramic layer that is the first ceramic layer according to the present invention, aluminum oxide or a ceramic layer mainly composed of aluminum oxide is used. Then, a ceramic layer having a two-layer structure using titanium oxide or a ceramic layer mainly composed of titanium oxide is applied as the conductive ceramic layer as the second ceramic layer, and the second ceramic layer is used as an electric resistance heating element, or By acting as a conductive material, it is possible to provide a heating device integrated with a metal article, preferably having a thickness of 1 mm or less.

  In particular, by applying the present invention as a metal article to a cylinder liner or an oil pan of an automobile engine, the temperature of the engine oil can be increased by heating them simultaneously or separately with the start of the engine. . Accordingly, it is possible to shorten the warm-up operation of the engine even in cold weather, eliminate fuel waste when starting the engine, and reduce exhaust gas emission.

  Further, the ceramic layer having the two-layer structure has an effect as a “heat shielding material or heat insulating material”, and the ceramic layer having the two-layer structure is applied to an oil pan which is an easily cooled member of the engine. Thus, it is possible to improve fuel efficiency by preventing unnecessary heat radiation from the engine.

(Basic experiment on ceramic layers)
The purpose of this basic experiment is to show two types of ceramic layers, such as an aluminum oxide layer, that have different peak values when heated at the same temperature in a graph showing the relationship between “spectral radiant energy density / radiation wavelength”. And a titanium oxide layer or the like are formed in a laminated structure.

  Confirm the presence or absence of the ceramic layer when the object to be heated is heated with this ceramic layer side as the heat receiving surface, and the magnitude of heat transfer (heat transfer amount or heat output from the heat receiving surface to the heat radiating surface side) by the combination of ceramic layers Is to do.

In addition, it is for confirming the heat shielding property or heat retention property of the two-layer ceramic layer.
A) A hot plate (30 × 40 cm, 5 mm thick aluminum plate, hereinafter referred to as “tray”) for cooking grilled buckwheat or stir-fried vegetables was prepared as an object to be heated.
B) The following four types of samples were prepared as ceramic layers provided on the lower surface of the tray, that is, on the heat source side.

[Sample 1] Ceramic layer (A): A ceramic layer having a thickness of about 100 μm was formed by plasma spraying aluminum oxide (Al ₂ O ₃ ) on the back surface (heat receiving surface) of the tray.

  “Sample 2” ceramic layer (B): A titanium oxide (Ti O2) plasma sprayed on the back surface of the tray to form a ceramic layer having a thickness of about 100 μm.

“Sample 3” ceramic layer (C): aluminum oxide (Al ₂ O ₃ ) is formed on the back surface of the tray to a thickness of about 100 μm, and titanium oxide (Ti O ₂ ) is further plasma-sprayed on the top surface to form a thickness of about 100 μm. Thus, a ceramic layer having a two-layer structure was obtained.

“Sample 4” ceramic layer (D): plasma sprayed titanium oxide (Ti O ₂ ) on the back surface of the tray to form a thickness of about 100 μm, and aluminum oxide (Al ₂ O ₃ ) on the top surface of about 100 μm. Thus, a ceramic layer having a two-layer structure was obtained. The ceramic layer of the sample 4 is formed in reverse of the sample 3 and the ceramic layer.

“Sample 5” “blank” with no ceramic layer on the back of the tray.
C) Experimental method Heat output of each tray described in “Samples 1 to 5” described above in a state of being heated to about 260 ° C. to 390 ° C. by adjusting the heat of the gas burner so that it burns stably and stably. In order to confirm the characteristics, the following measurements were performed. At this time, the gas supply amount was made constant so that the strength of the gas burner was as constant as possible.
-For the temperature measurement of the upper surface of the tray, the temperature of the same point is measured and compared for the trays of Samples 1 to 5 using a non-contact radiation thermometer (Yokogawa, PM series).
-The tray is supported at a position 15 cm above the gas burner that has reached a certain temperature, and the surface temperature is measured using the thermometer.

  Details of this experiment are shown in Table 1.

      From the results in Table 1, the following was found.

A) The order of evaporation: 3>2>4> 1 >> 5
B) Highest surface temperature order: 3>2>4> 1 >> 5
[Evaluation of experimental results]
1) As for the surface temperature of the tray, it can be seen that “sample 2” (titanium oxide layer) is clearly superior to “sample 1” (aluminum oxide layer) in this temperature range.
2) In the above temperature range, when the ceramic layer is a single layer, “Sample 2” (titanium oxide) is superior to “Sample 1” (aluminum oxide).
3) “Sample 3” [aluminum oxide (lower side) / titanium oxide (upper side) rather than “sample 4” [titanium oxide (lower side) / aluminum oxide (upper side)] ] Is the best.

Further, when the heat receiving surface is a metal surface (tray 5), the surface temperature is “310 ° C.”, whereas “Sample 3” is “393 ° C.”, and between them, “80 ° C.” is large. It was found that a temperature difference was formed.
4) Compared with the “sample 5” having no ceramic layer at all, the single layer of aluminum oxide or titanium oxide is a composite layer such as “sample 3” or “sample 4”. It was also found that the tray with the ceramic layer was 30 to 40% faster in heat transfer (for example, comparing the evaporation rate of water in a beaker).
5) The heat-treated surface of the metal article to-be-heated object) has a lower efficiency of receiving heat from the heat source than the thermal sprayed aluminum oxide or titanium oxide ceramic layer, that is, the heat output of the tray upper surface.

  As the kind of the ceramic layer, aluminum oxide is effective at a low temperature, but titanium oxide is effective at a high temperature.

  In addition, the order in which the ceramic layer is provided on the surface of the metal object to be heated is a combination in which the aluminum oxide layer is disposed in the lower layer and the titanium oxide layer (conductive material) is disposed in the upper layer in the reverse order. The heat receiving efficiency (transferability of the received heat) is superior to the formed one.

Although details are not described, the ceramic layer is preferably a plasma sprayed type of one, and when it becomes a mixture, the heat transfer property tends to be inferior.
(Experiment for heat insulation and heat insulation effect)
Two aluminum pans having a diameter of 200 mm, a depth of 60 mm, and a thickness of 3 mm were used. One is a plasma sprayed laminated ceramic layer of “aluminum oxide layer / titanium oxide layer” similar to “Sample 3” on its bottom and side surfaces (treatment pan), and a blank one that is not treated (nothing). Processing pan) was prepared.

  And the water put into the said 2 pots was heated to 90 degreeC, and the heat | fever was interrupted | blocked immediately after that and both natural cooling time was compared. As a result, it was found that the temperature of the hot water was slower in the laminated ceramic-treated pan than in the untreated pan. This indicates the heat insulating property or heat shielding property of the ceramic layer having a laminated structure.

It has been found that a remarkable phenomenon in this experiment has the property of actively taking in heat depending on the type of ceramic and the order of lamination. Further, the property of actively taking in this heat is to have a “heat shielding effect or heat insulating effect” that prevents the heat from being released. By using the conductive ceramic layer, the laminated ceramic layer can be effectively used as an ultra-thin ceramic heater (for example, 1 mm or less).
(Example)
FIG. 1 is a perspective view showing a main part in which a resistance heating element using a ceramic layer according to the present invention is formed on the surfaces of a cylinder liner 2 and an oil pan 3 of an automobile engine 1. FIG. 2 is a side view of the oil pan, and FIG. 3 is a sectional view showing a ceramic layer formed by plasma spraying on the surface of the cylinder liner 2 and a front view showing the ceramic layer in an exploded manner.

  The first ceramic layer C1 (insulating base layer: aluminum oxide) is formed by spraying electrically insulating ceramics on the surface of the cylinder liner 2, and then electric conductivity (electricity) is formed on the first ceramic layer C1. Resistor ceramic is sprayed to form a second ceramic layer C2 (titanium oxide) to form a multilayer ceramic layer C3 having a two-layer structure.

  Next, the feeder lines 4 are arranged at the edge portions of the second ceramic layer C2. The feeder 4 can be electrically connected to the surface of the second ceramic tank C2 using a conductive paste made of tungsten, for example. Also, a metal band such as a copper plate of about 10 mm can be used.

  The outer peripheral surface of the composite ceramic layer C3 is covered with a heat resistant resin (for example, polyimide or silicon resin) to provide water resistance and insulation.

  The power supply line 4 is connected to a power supply device (inverter) that is connected to wirings 5 and 5 and uses a battery (not shown) as a power source. Through this power supply device, the direct current is converted into AC 100V to supply power. The second ceramic layer C2 generates heat by energization from the power feeding device. As a result, the composite ceramic layer C3 generates heat and the cylinder liner 2 is heated from the outer peripheral surface.

  As shown in FIG. 2, the composite ceramic layer C3 having the above-described configuration is formed in a covering shape in a U shape in a side view over the three sides of the oil pan 3 in the longitudinal direction and the bottom surface. Then, the power supply line 4 is arranged on both edges of the composite ceramic layer C3 as described above, the wiring 5 is connected to the power supply line, and power is supplied from the power supply device through the wiring 5, whereby the oil pan 3 is removed from the outer peripheral surface. The engine is heated for a short time (within about 10 to 20 minutes) after starting the engine. The electrical resistance value between the electrode wires 4 to 4 in FIGS. 1 and 2 is about 100Ω.

  Although not shown in detail, the surface of the composite ceramic layer C3 is thermally and electrically insulated by a heat resistant resin or the like as in FIG. 3 and further protected from damage. Further, if necessary, the entire outer surface of the ceramic layer C3 can be covered with a metal cover to give strength to withstand external impacts.

FIG. 4 is a front view showing a state of the feeder line 4 connected to the second ceramic layer C2 forming the composite ceramic layer C3 provided on the outer peripheral surface of the cylinder liner 2 and the outer peripheral surface of the oil pan 3. The state shown in FIG. 1 is in this state.
(Ceramic layer deformation pattern)
The first ceramic layer C1, the second ceramic layer C2 and the composite ceramic layer C3 are most preferably provided so as to cover the outer peripheral surface of the cylinder liner 2 as shown in FIGS. Accordingly, various patterns such as parallel vertical stripes, diagonal stripes, and stripes crossed in two diagonal directions may be employed on the outer peripheral surface of the cylinder liner 2.

  FIG. 5 shows alumina (Al 2 O 3) used as the first electrically insulating ceramic layer C 1 and titanium oxide (Ti 2) used as the second ceramic layer C 2 that has electrical conductivity and functions as a heat-generating electrical resistor. 3 is a graph showing a schematic relationship between “spectral energy density” (vertical axis) and “wavelength” (horizontal axis) when a ceramic made of O2 is heated to a constant temperature.

  The second ceramic layer C2 (heat generation layer) has a peak value at point X, the first ceramic layer C1 has a peak value at line Y, and the second ceramic layer C2 has a higher frequency than the first ceramic layer C1. It has the peak value of the distribution curve in a short place.

  The distance between the wavelengths a and b at the positions X and Y of the two peak values is related to the property of directing the direction of movement of heat energy. (Heat transferability) seems to be good.

  According to the present invention, the composite ceramic layer C3 composed of the first ceramic layer C1 and the second ceramic layer C2 is formed directly on the surface (outer surface) of the heated object such as the cylinder liner 2 and the oil pan 3 by plasma spraying. To do. The second ceramic layer C2 is used as an electric resistance heating element, and the cylinder liner 2 and the like can be directly heated by energizing the second ceramic layer C2.

  In addition, since the cylinder liner 2 and the oil pan 3 can be heated by energizing the second ceramic layer C2 formed by plasma spraying as an electric resistance heating element (conductive material) from the power feeding device, Even when the engine is cooled on the ground, the cylinder liner and other members are heated as the starter starts. As a result, the member in contact with the engine oil is heated to indirectly heat the engine oil, so that the time required for the warm-up operation can be shortened as compared with a normal engine. As a result, fuel costs required for warm-up operation can be reduced, and wasteful exhaust emission can be suppressed.

  In the present invention, a laminated ceramic layer C3 is formed by laminating an electrically insulating first ceramic layer C1 on a surface of a metal article (heated object) such as an oil pan and a conductive ceramic layer C2 thereon. Therefore, the laminated ceramic layer C3 itself can be used as a heating element, and an extremely thin electric heating device is added.

  Therefore, it has both the effects of the laminated ceramic layer C3 such as “heat receiving property, thermal conductivity, or property of guiding heat in one direction” and the property as an electric heating heater, and has excellent thermal efficiency. An electrothermal heating apparatus can be provided.

  Furthermore, since the metal article (object to be heated) and the heating element are integrated, a compact heating device (heater) can be obtained, for example, the startability in the winter of automobile engines is greatly improved. can do.

  In the present invention, it is best to use aluminum oxide for the first ceramic layer C1 constituting the laminated ceramic layer C3 and titanium oxide for the second ceramic layer C2, but other ceramics have similar characteristics. If it is a thing, this can be used.

  In addition, the present invention can be applied not only to an automobile engine but also to a cooking apparatus such as a grill cooker.

It is the schematic which shows the main members of the engine to which this invention is applied. 3 is a side view of an oil pan to which the present invention is applied. 1 is a cross-sectional view of a part of a cylinder liner to which the present invention is applied, and a part of the cylinder liner. It is a conceptual diagram which shows the whole composite ceramic layer. It is a graph which shows the relationship between the spectral energy density and the wavelength in the state which heated the ceramic layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder liner 3 Oil pan 4 Feeding line 5 Wiring C1 1st ceramic layer (electrical insulation layer)
C2 Second ceramic layer (conductive layer)
C3 composite ceramic layer (acts as a heater or heat shield layer)

Claims (6)

  A first ceramic layer made of an electrically insulating ceramic layer and a second ceramic layer made of a conductive ceramic layer are formed on the upper surface of the first ceramic layer by plasma spraying on the surface of the metal article, and the second ceramic layer is further formed. A feed line is arranged at both ends of the layer, and the metal article is heated using the second ceramic layer as a heating element and the first ceramic layer as a heat induction layer by energizing between both feed lines. A heating method using the ceramic layer as a heating element.   When the first ceramic layer and the second ceramic layer are heated to the same temperature, in the characteristic curve drawn in the relationship of spectral radiant energy density / wavelength radiated from the ceramic layer, the peak values indicated by these curves The long wavelength ceramic layer was directly sprayed on the metal surface as the first ceramic layer, and the short wavelength ceramic layer was laminated on the first ceramic layer as the second ceramic layer. A heating method using the ceramic layer according to claim 1.   The first ceramic layer is a ceramic layer mainly composed of aluminum oxide or aluminum oxide, and the second ceramic layer is a ceramic layer mainly composed of titanium oxide or titanium oxide. Heating method using a ceramic layer.   A first ceramic layer made of an electrically insulating ceramic layer is thermally sprayed on one or both of a cylinder liner supported by a cylinder block of an engine and an oil pan disposed at a lower portion of the cylinder block, and A second ceramic layer made of a conductive ceramic layer is sprayed and laminated on the surface of the first ceramic layer, and the second ceramic layer is formed on one or both of the cylinder liner and the oil pan at the start of the engine. An engine configured to generate heat by energization and to heat one or both of the cylinder liner and the oil pan to reduce the viscosity of the engine oil.   The engine according to claim 4, wherein the first ceramic layer is a ceramic layer mainly composed of aluminum oxide, and the second ceramic layer is titanium oxide.   The engine heat dissipation is characterized in that a ceramic layer with a two-layer structure of an aluminum oxide layer and a titanium oxide layer is provided on the outer surface of an oil pan provided under the cylinder block of the engine, and this ceramic layer is used as a heat shield layer. Prevention device.

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