JPH03117617A - Cooling structure of internal combustion engine - Google Patents

Abstract

PURPOSE:To effectively cool a high temperature portion without a cooling medium in a simple structure by operating a thermal electric power generating element installed on the high temperature portion of an internal combustion engine according to a control signal from a control device. CONSTITUTION:A ring-shaped thermal electric power generating element 18 for cooling an intake pipe 11 is installed on the outer periphery on the intake port 7 side of the intake pipe 11. The outer periphery of a cylinder 2 is covered with a cylindrical thermal electric power generating element 20 formed by the same material as the thermal generating element 18. In this arrangement, when the thermal electric power generating element 18 is operated by a control device 16 at the time of long time low speed running at high outside air temperature, heat energy absorbed from the intake pipe 11 is converted into electric energy, whereby the intake pipe 11 is positively cooled. Cooling for the cylinder 2 is performed by operating the thermal electric power generating element 20 by a control device 16. Accordingly, an internal combustion engine E can be cooled without a cooling medium such as cooling water, cooling air or the like.

Description

Detailed Description of the Invention A8 Purpose of the Invention (1) Industrial Application Field The present invention is a method for cooling cylinders and intake pipes that are heated to high temperatures by the operation of an internal combustion engine without using cooling water or cooling air. This invention relates to a cooling structure for an internal combustion engine.

(2) Conventional technology Conventional cooling systems for internal combustion engines are broadly divided into water-cooling and air-cooling. In the case of water-cooling, a water pump supplies cooling water to a water jacket formed in the cylinder block or cylinder head. Cooling water, whose temperature has risen, is cooled by a radiator and a radiator fan. In the case of an air-cooled type, cooling is performed by applying cooling air introduced through a shroud or the like to fins formed in the high temperature section.

(3) Problems to be Solved by the Invention However, with either the water-cooling type or the air-cooling type described above, water jackets, water pumps, radiators, radiator fans, shrouds, fins, etc. are required, which increases weight and This is a factor that increases costs and makes maintenance difficult. Furthermore, even if the intake pipe connecting the carburetor and the intake boat is installed via an insulator, it may become overheated under extreme conditions. For this reason, there is an inconvenience that percolation and the like occur.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to effectively cool a high-temperature section of an internal combustion engine with a simple structure without using a refrigerant such as water or air.

B1 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a thermoelectric power generating element, which is installed in a high-temperature section of an internal combustion engine and converts thermal energy taken from the high-temperature section into electrical energy. The first feature is that the thermoelectric power generating element is cooled by attaching the thermoelectric generator and operating the thermoelectric generating element based on a control signal from a control device.

In addition to the first feature, the present invention has a second feature that the thermoelectric power generation element is connected to a battery, and the battery is charged with the electric power generated by the thermoelectric power generation element.

Furthermore, in addition to the first feature, the present invention provides that the thermoelectric generating element includes an n-type semiconductor formed by adding manganese to iron silicide;
The third feature is that it is composed of a stack of n-type semiconductors made by adding cobalt to iron silicide.

(2) Effect According to the above-described first feature of the present invention, when the thermoelectric generating element installed in the high temperature section of the internal combustion engine is activated by a control signal from the control device, the thermal energy of the high temperature section is transferred by the thermoelectric generating element. It is converted into electrical energy, resulting in cooling of the hot part.

According to the second feature of the present invention, thermal energy taken from the high temperature section is converted into electrical energy by the thermoelectric generating element, and this electrical energy is used to charge the battery. This makes it possible to omit or downsize the generator.

Furthermore, according to the third feature of the present invention, by using a semiconductor in which cobalt or manganese is added to iron silicide, a high-performance, easy-to-manufacture thermoelectric power generation element can be obtained at low cost.

(3) Examples Hereinafter, the present invention will be explained in detail based on the drawings.

The drawing shows a four-stroke internal combustion engine mounted on a motorcycle, and this engine E includes a cylinder 2 extending from a crankcase 1 and a cylinder head 3 attached to the top of the cylinder 2.

A crankshaft 4 supported by a crankcase 1 and a piston 5 slidably fitted into a cylinder 2 are connected via a connecting rod 6.
An intake valve 9 and an exhaust valve 10 are attached to the intake port 7 and the exhaust port 8, respectively, which are formed in the intake port 7 and the exhaust port 8, respectively.

A well-known carburetor 12 equipped with a throttle valve is installed at the upstream end of an intake pipe 11 that extends upward from the intake port 7 and curves horizontally in the middle. The air is mixed with air supplied from the air cleaner, atomized, and supplied to the combustion chamber of the cylinder head 3 through the intake pipe 11 and the intake port 7.

A heating element 13a is disposed on the inner wall of the intake pipe 11 on the carburetor reflex 12 side so as to cover the entire circumference of the inner wall.

13b. This heating element 13a, 1
3b is installed in two parts so as to be located on the outside and inside in the bending direction of the intake pipe 11, and is installed to detect the throttle opening degree detector 14 that detects the throttle opening degree and the temperature of a predetermined part of the engine E. Power is supplied from a battery 17 via a control device 16 to which a detection signal from a temperature sensor 15 is input.

The heating elements 13a and 13b are made by mixing carbon powder with epoxy resin or urethane resin to form a thin film with a thickness of 0.2 mm to 0.3 mm with high electrical resistance, and sandwiching this between heat-resistant resin to form a film. It is attached to the inner surface of the intake pipe 11 using an adhesive. Since the heating elements 13a and 13b are made of carbon and resin, they can be molded into any shape and can be manufactured at low cost.

On the outer periphery of the intake pipe 11 on the intake port 7 side, the intake pipe 11
A ring-shaped thermoelectric generating element 18 for cooling is attached. The thermoelectric generating element 18 is a type of semiconductor, as will be described in detail later, and has the function of being activated by a control signal from the control device 16 to take away thermal energy from the intake pipe 11 and convert it into electrical energy. . The thermoelectric generator 18 is connected to the battery 17 via a regulator 19, and the electric power generated by the thermoelectric generator 18 is used to charge the battery 17.

The thermoelectric power generating element 18 is mainly composed of iron silicide, which is obtained by mixing and sintering silicon and iron powder, and contains about 3 manganese atoms.
．． A thickness of 0.3 μm or more consisting of a p-type semiconductor doped with 3% and an n-type semiconductor doped with approximately 1.7% cobalt in atoms.
It is composed of 0.8 cylinder elements, and has a structure in which pixel elements are stacked and connected in series, and the gaps between them are filled with enamel material that has excellent heat conductivity. Then, the thermoelectric generating element 18
Since it is formed by sintering, the shape can be arbitrary, and since it uses inexpensive materials such as iron and silicon, it can be manufactured at low cost.

The outer periphery of the cylinder 2 is covered with a cylindrical thermoelectric generator 20 made of the same material as the thermoelectric generator 18, and this thermoelectric generator 20 also cools the cylinder 2 (throttle opening detector 14). It is connected to and controlled by a control device 16 to which the detection signal from the temperature sensor 15 is input, and is also connected to a battery 17 via a regulator 19 to utilize the electrical energy generated by its operation.

Next, the operation of the embodiment of the present invention having the above-described configuration will be explained.

When starting the engine E when the engine temperature Te detected by the temperature detector 15 is below a predetermined value, the control device 16 controls the heating element 13a from the battery 17.

Electric power is supplied to the heating elements 13b, and the temperature of the heating elements 13a and 13b quickly rises. The fuel supplied from the carburetor 12 to the intake pipe 11 at low temperatures is not sufficiently atomized, and when relatively large fuel particles collide with the heating element 13a attached to the outside of the bent intake pipe 11, the fuel particles It is heated by the heating element 13a and evaporates quickly. On the other hand, the heating element 13 attached to the inside of the bent part of the intake pipe 11
The fuel that adheres to b and flows down due to the action of gravity is also heated by this heating element 13b and quickly evaporates. In this way, fuel is effectively evaporated during a cold start when the temperature of the engine E is low, improving startability.

Even after the engine E has started, if the engine temperature Te is 100°C or less and the throttle opening Th is 50% or less, the heating element 13a
, 13b is continued to smoothly warm up the engine E, and when the engine temperature Te reaches 100° C., it is assumed that the warm-up operation has ended and the power supply to the heating elements 13a and 13b is stopped.

However, even if the engine temperature Te is 100°C or less, if the throttle opening Th is 50% or more, high output of the engine E is required, and in this case, the heating element 13
Power is not supplied to a and 13b.

Heating of the intake pipe 11 by the heat generating elements 13a and 13b is performed not only at the time of the above-mentioned cold start, but also when the intake pipe 11 is likely to cause icing due to overcooling, for example, in cold weather.

On the other hand, if the vehicle is driven at low speed for a long time when the outside temperature is high, the flow rate of fuel supplied from the carburetor 12 to the intake pipe 11 decreases, and cooling of the intake pipe 11 by the fuel cannot be expected. In such a case, the thermoelectric generating element 18 is activated by the control device 16 to convert the thermal energy absorbed from the intake pipe 11 into electrical energy.
Actively cool down. In this way, the heating element 13a
.

By selectively operating the thermoelectric generator 13b and the thermoelectric generator 18, the temperature of the intake pipe 11 can be maintained at an appropriate temperature. Furthermore, immediately after the engine E stops, cooling by fuel is not performed at all, and the temperature of the intake pipe 11 rises rapidly due to heat transfer from the high-temperature cylinder head 3. Overheating of the intake pipe 11 is prevented by operating the thermoelectric generating element 18 for, for example, 15 minutes after the engine stops.

Electric power generated by the thermoelectric generating element 18 as the intake pipe 11 is cooled is supplied to the battery 17 via the regulator 19 and used for charging. This allows the conventional battery charging generator to be abolished or downsized.

In addition, the cooling of the cylinder 2, which was conventionally performed by cooling fins, is also performed by the thermoelectric generating element 20 attached to the outer periphery of the cylinder 2, and the electric power generated by cooling is used to charge the battery 17 as described above. .

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various small design changes can be made without departing from the scope of the invention described in the claims. Is possible.

For example, the heating element 13a shown in the embodiment.

The conditions and numerical values for operating the thermoelectric generators 13b and 18, 20 are merely examples, and can be changed as necessary. Furthermore, it is not necessarily necessary to attach the thermoelectric generating element 1820 to both the intake pipe 11 and the cylinder 2.
Of course, it can be attached to only one side,
It is also possible to attach a thermoelectric generating element to the cylinder head 3, which becomes hot during operation of the engine E.

Effects of the C0 Invention As described above, according to the first feature of the present invention, the engine can be cooled without using a refrigerant such as cooling water or cooling air. , radiator, radiator fan, shroud, fins, etc. are no longer required. As a result, it is possible not only to reduce costs by reducing the number of parts, but also to improve drivability and fuel efficiency by reducing weight, and to improve warm-up performance by reducing heat mass.

Furthermore, according to the second feature of the present invention, the electrical energy generated by the thermoelectric generating element when cooling the high temperature section is used to charge the battery, so that the generator can be omitted or miniaturized.

Furthermore, according to the third feature of the present invention, by using a semiconductor in which cobalt or manganese is added to iron silicide, a high-performance, easy-to-manufacture thermoelectric power generation element can be obtained at low cost.

[Brief explanation of drawings]

The drawing shows an embodiment of the present invention, and is a partial sectional view of an internal combustion engine employing the cooling structure. 2... Cylinder (high temperature part), 11... Intake pipe (high temperature part), 16... Control device, 17... Battery, 18
...Thermoelectric power generation element, 20...Thermoelectric power generation element E...Internal combustion engine

Claims (3)

[Claims] (1) A thermoelectric generating element (18, 20) that converts the thermal energy taken from the high-temperature part (2, 11) into electrical energy is attached to the high-temperature part (2, 11) of the internal combustion engine (E), and control is performed. A cooling structure for an internal combustion engine, characterized in that the thermoelectric generating element (18, 20) is operated based on a control signal from a device (16) to cool the high temperature section (2, 11). (2) The thermoelectric generating elements (18, 20) are connected to the battery (17).
), and this battery (17) is connected to the thermoelectric generating element (
The cooling structure for an internal combustion engine according to claim 1, wherein the cooling structure for an internal combustion engine is charged with the electric power generated by the parts 18 and 20). (3) The thermoelectric generating element (18, 20) is composed of a laminate of a p-type semiconductor made by adding manganese to iron silicide and an n-type semiconductor made by adding cobalt to iron silicide. A cooling structure for an internal combustion engine according to claim (1).