JP4449671B2 - Engine thermoelectric element mounting structure - Google Patents

Description

  The present invention relates to a structure for attaching a thermoelectric element to an exhaust system portion of an engine.

  A technique in which thermoelectric elements are respectively attached to an upstream portion and a downstream portion of an exhaust pipe in an engine and power is generated by the thermoelectric elements is known from Patent Document 1 below.

JP-A-11-257064

  However, in this case, a thermoelectric element on the high temperature side is mounted along the exhaust pipe surface far away from the exhaust port of the engine, and this thermoelectric element cannot always receive heat efficiently from the exhaust pipe. There was a problem that it was difficult to increase the power generation efficiency of the element.

  An object of the present invention is to easily increase the power generation efficiency when a thermoelectric element is attached to an exhaust system portion of an engine to generate power.

For this reason, the engine thermoelectric element mounting structure according to the first aspect of the present invention is such that a thermoelectric element that generates electric power due to a temperature difference between both sides is supported by the gasket through the through hole of the gasket, and protrude from both end surfaces, with one surface of the thermoelectric element is pressure against the outlet end face of the exhaust port in the engine body, each exhaust on the other side is attached to the outlet end face the exhaust port of the thermoelectric element road is in contact pressure to the inlet flange of the exhaust manifold communicating with, the thermoelectric element is sandwiched between the outlet end face and the inlet flange. In the engine thermoelectric element mounting structure according to the second aspect of the present invention, the inlet flange portion of the exhaust manifold is attached to the outlet end surface portion of the exhaust port in the engine body so that the exhaust passages communicate with each other. A thermoelectric element that generates electricity due to a temperature difference is fitted into a recess formed on the outlet end surface side surface of the inlet flange portion, and the inlet flange portion side surface of the engine body and the outlet end surface side surface of the exhaust manifold. The liquid packing applied between the surface on the inlet flange portion side of the engine body and the surface on the outlet end surface portion side of the exhaust manifold is cured.

That is, while the engine body is generally constantly cooled by engine cooling water, the exhaust manifold is constantly heated by the high-temperature exhaust gas and kept at a high temperature, so the outlet end face of the exhaust port that is relatively cold Between the outlet end face and the inlet flange, the thermoelectric element that is sandwiched between the inlet flange of the exhaust manifold, which is relatively hot, and securely in contact with each other is stable and efficient. It is possible to generate electricity.

In the following, each embodiment of the present invention shown in the drawings will be described with the same reference numerals given to the equivalent parts.
1 and 2, an outlet end surface portion 3 of each exhaust port 2 is formed in a cylinder head 1 of an in-vehicle four-cylinder engine, and an inlet flange portion 5 of the exhaust manifold 4 is not shown on the outlet end surface portion 3 with a gasket 6 interposed therebetween. By being attached with bolts, each exhaust port 2 and each exhaust passage 7 of the exhaust manifold 4 communicate with each other through a through hole 8 formed in the gasket 6.

  Further, a shallow concave portion 10 having a substantially rectangular shape is formed between the exhaust ports 2 on the exhaust manifold 4 side surface of the outlet end surface portion 3, and each exhaust gas is formed on the cylinder head 1 side surface of the inlet flange portion 5. A substantially rectangular shallow recess 11 is formed between the passages 4, and a substantially rectangular through hole 12 is provided between each through hole 7 of the gasket 6.

  Each thermoelectric element 13 is inserted into the through hole 12 of the gasket 6 and supported by the gasket 6, and one surface 14 is fitted in the recess 10 and the other surface 15 is fitted in the recess 11. Thus, when the inlet flange portion 5 is attached to the outlet end surface portion 3 with the gasket 6 interposed therebetween, one surface 14 is pressed against the outlet end surface portion 3 and at the same time, the other surface 15 is pressed against the inlet flange portion 5. ing.

On the other hand, the cylinder head 1 is usually cooled as a whole by engine cooling water. In the above-described apparatus, a cooling water channel 20 is formed in the cylinder head 1 particularly in the vicinity of the concave portion 10 of the outlet end face portion 3. The vicinity of the recess 10 is constantly cooled by the engine coolant flowing in the cooling water channel 20 and is kept at a relatively low temperature, but the exhaust manifold 4 is always heated by the high-temperature exhaust gas and the whole is kept at a relatively high temperature. Has been.
A conducting wire (not shown) connected to the thermoelectric element 13 is guided to the outside through an appropriate hole formed in the inlet flange portion 5.

In the above-described apparatus, each thermoelectric element 13 is in contact with the outlet end surface portion 3 whose one surface 14 is at a relatively low temperature, and is in contact with the inlet flange portion 5 whose other surface 15 is at a relatively high temperature. Since the inlet flange portion 5 is bolted to the outlet end surface portion 3 and an appropriate pressing force can be easily applied to each thermoelectric element 13, each thermoelectric element 13, the outlet end surface portion 3 and the inlet flange portion As a result, the thermoelectric element 13 can generate power stably and efficiently due to a large temperature difference generated between the outlet end face portion 3 and the inlet flange portion 5. There is a great advantage in that the heat energy in the exhaust gas in the manifold 4 can be effectively recovered and charging of the vehicle-mounted battery can be easily supported.
Note that, when the inlet flange portion 5 is bolted, if a predetermined tightening pressure is applied to the gasket 6, a pressing force is generated due to thermal expansion of the thermoelectric element 13 itself when the thermoelectric element 13 generates power. Sufficient heat transfer can be obtained with a normal tightening pressure.

  Each thermoelectric element 13 is inserted through the through hole 12 of the gasket 6 and supported by the gasket 6, and one surface 14 is fitted in the recess 10, and the other surface 15 is inserted in the recess 11. The thermoelectric elements 13 can be securely supported while being fitted, and a special structure for holding the thermoelectric elements 13 is not required, so that the cost required for mounting the thermoelectric elements 13 can be easily achieved. It becomes possible to reduce.

  Moreover, if each thermoelectric element 13 is supported by the gasket 6, the gasket 6 generally has a heat insulating property, so that a relatively large temperature difference between both surfaces 14 and 15 of each thermoelectric element 13 can be easily maintained. Thus, the power generation performance of each thermoelectric element 13 can be kept high.

  In the embodiment shown in FIG. 3, recesses 30 are formed between the exhaust passages 7 on the cylinder head 1 side surface of the inlet flange portion 5 in the exhaust manifold 4, and each thermoelectric element 13 fitted in the recess 30. Slightly protrudes from the cylinder head 1 side surface and directly contacts the exhaust manifold 4 side surface of the outlet end surface portion 3 of the cylinder head 1, and the exhaust manifold 4 side surface of the outlet end surface portion 3 and the cylinder head of the inlet flange portion 5. The liquid packing 31 is applied between the one side surface and hardened, and the same effects as the above-described embodiment can be exhibited.

  Moreover, since the exit end face part 3 and the inlet flange part 5 are generally flat, it is easy to form the recesses 10, 11 and 30 into which the thermoelectric element 13 is fitted, and special processing such as warping the thermoelectric element 13 is performed. It can be easily installed without having to.

  Furthermore, if the thermoelectric element itself has a function as a gasket, the thermoelectric element can be disposed over almost the entire surface of the outlet end face portion 3 and the inlet flange portion 5, and more power generation functions can be obtained.

  In each of the above-described embodiments, the outlet end surface portion 3 and the inlet flange portion 5 that are connected to each other are connected to the vehicle rear side of the engine body (vehicle rear side bank in the case of a V-type engine), that is, to the engine body. If it is provided at a position downstream of the engine cooling air, the influence of the engine cooling air on the exhaust manifold 4 is mitigated, the inlet flange portion 5 is likely to become higher temperature, and the power generation capability by the thermoelectric element 13 is further improved. Needless to say, you can.

The schematic perspective exploded view in the Example of this invention. II-II longitudinal cross-sectional enlarged view of FIG. The longitudinal cross-sectional view equivalent to FIG. 2 in the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder head 3 Outlet end surface part 4 Exhaust manifold 5 Inlet flange part 6 Gasket 10,11 Concave part 12 Through-hole 13 Thermoelectric element 20 Cooling water channel 30 Concave part 31 Liquid packing

Claims (4)

A thermoelectric element that generates electricity due to a temperature difference between the two surfaces is inserted through the through hole of the gasket and supported by the gasket and protrudes from both end faces of the gasket, and one surface of the thermoelectric element is an outlet end face portion of the exhaust port in the engine body in addition to pressure contact, the other surface is in contact with pressure to the inlet flange of the exhaust manifold the exhaust passage respectively attached to the outlet end face to the exhaust port are communicated, the thermoelectric elements the outlet end face of the thermoelectric element And a thermoelectric element mounting structure of an engine sandwiched between the inlet flange portion and the inlet flange portion. An exhaust flange inlet flange portion is attached to the exhaust port outlet end surface of the engine body so that the exhaust passages communicate with each other, and a thermoelectric element is formed on the outlet flange end surface of the inlet flange portion due to a temperature difference between both surfaces. Is fitted into the recessed portion and directly contacts the inlet flange side surface of the engine body and the outlet end surface side surface of the exhaust manifold, and the inlet flange side surface of the engine body and the exhaust manifold side surface. The engine thermoelectric element mounting structure in which the liquid packing applied between the outlet end surface and the surface is hardened . 3. The thermoelectric element mounting structure for an engine according to claim 1, wherein a cooling water passage is formed in the engine body in the vicinity of the outlet end face portion . 4. The thermoelectric element mounting structure according to claim 1, wherein the outlet end face portion and the inlet flange portion are provided at a position downstream of the engine cooling air with respect to the engine body.

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