SI22306A - Exhaust manifold of internal combustion engine with divided segments enclosed in hermetically closed, cooled and isolated exhaust manifold housing - Google Patents

Abstract

Subject of the submitted invention is an exhaust collector of internal combustion engines. In order to increase the output power of internal combustion engines the exhaust gases can be used to make them drive a turbine charger which compresses the air prior entering the engine thus increasing the content of oxygen required for combustion. The exhaust collector is preferably made from a welded construction from stainless steel which consists of at least two elements (5), preferably made from fireproof steel with low oxidation levels, for example EN 1.4435 or EN 1.4841 stainless steel, which are connected in- between with longitudinally freely moving links (35) and are by the input part of the collector attached to the sealing panel (1) on the engine side. With the output part of the collector it is attached to the sealing panel (28) of the exhaust outlet, where the specified internal exhaust pipe is enclosed hermetically in a jacket (13, 1, 7) of the exhaust collector filled with exhaust gases (46) under pressure, with the insulated external surface (9) of the exhaust collector and external surface (12, 14, 1, 28) of the exhaust collector being cooled by the engine coolant (17).

Description

Internal combustion engine exhaust manifold with separate segments, enclosed in a hermetically sealed, cooled and insulated exhaust manifold housing

BACKGROUND OF THE INVENTION

The object of the present invention is an internal combustion engine exhaust manifold with separate segments enclosed in a hermetically sealed, cooled and insulated exhaust manifold housing. To maximize the power output of internal combustion engines, we utilize the exhaust gases by blowing a turbocharger that compresses the air before entering the engine, thereby increasing the oxygen content required for combustion. Increasing the exhaust gas temperature results in higher turbocharger power and higher air pressure in front of the engine intake valve. However, very high exhaust temperatures also increase the exhaust manifold temperature and, consequently, the exhaust manifold. A high exhaust manifold temperature results in a high external exhaust manifold surface temperature. For many purposes with enclosed engine compartments, e.g. in boats, this is dangerous and illicit. For some other purposes, such as hpr. electric generators, this is not recommended because it heats the engine surroundings and raises the ambient air temperature. Higher ambient temperature, however, raises the intake air temperature, thereby reducing the intake air density. With reduced air density and increased intake air temperature, engine power decreases and N0 _x emissions increase. For vehicles with enclosed and soundproofed engine compartments, the high temperature of the outer faces of the exhaust manifold is a disadvantage. Over the last 50 years, many different systems for isolating exhaust manifolds have emerged. Isolated exhaust manifolds result in even higher temperatures: the outer faces and the manifold, which further increases the thermal expansion of the exhaust pipes. Excessive expansion of the exhaust manifold causes the exhaust manifold pipes to crack or damage the manifold gasket seals. There are many solutions where the exhaust manifold consists of several segments interconnected by longitudinally moving joints or fuzzy oversized joints. Although such solutions compensate, they do not prevent the exhaust manifold and thermal expansion, overheating of the outer surfaces of the engine compartment overheating. Especially for boat engines, there are many known solutions with directly or indirectly liquid-cooled exhaust manifolds. Such solutions prevent excessive expansion of the exhaust manifold pipes and ensure that the outer faces of the exhaust manifold are sufficiently cool. For intake gasoline engines, this is a good solution, but sometimes over-weights the engine. For pressure-fed engines, especially those with high power gains, the exhaust manifold's exhaust pipe cools the exhaust gas temperature at the inlet of the turbocharger, reducing the power of the turbocharger and, consequently, the turbocharger's filling pressure. All of these factors result in higher fuel consumption and lower engine power. At the same time, the ventilation of the combustion chamber with fresh air is reduced due to the relatively: lower charge pressure behind the turbine charger during valve overlap, resulting in a higher thermal load on the piston and the cylinder head compartments a.

Accordingly, the object and purpose of the present invention is to provide a light, airtight, compact design with an integrated engine coolant cooler. The outer surfaces of the exhaust manifold are cooled while the inner exhaust pipe is insulated. It consists of modular pipe segments interconnected by sliding joints, which allow thermal expansion and prevent thermal deformation and damage due to high temperatures. This saves a large part of the exhaust energy required to drive the turbine engine charger and increase engine power. It is also an object of the present invention to reduce the cost of production.

Summary of the Invention

The exhaust manifold of the present invention is a welded stainless steel structure consisting of individual exhaust pipes 4, 5, 26, preferably made of low-oxidation refractory steel, e.g. made of EN 1.4435 or EN 1.4841 stainless steel, and interconnected with longitudinally movable joints 35 and connected at the inlet side of the exhaust manifold to the motor gasket 1 and at the outlet side to the outlet gasket 28. Individual, not absolutely airtight, exhaust pipes 4, 5 and 26 are embedded in an airtight enclosure of the exhaust manifold 13, 1, 7 filled with pressurized exhaust gas

46, and fused with slightly leaky joints 35. This construction also prevents toxic components of the exhaust from leaking into the surroundings. The whole structure is covered by the insulated outer surfaces of the exhaust manifold 9 and partly by the liquid engine coolant 17 cooled outside the exhaust manifolds 12, 14, 1 and 28. The engine coolant is cooled in the integrated engine coolant cooler (Figure 1).

Aim and purpose of the invention

The invention is designed so that individual exhaust pipes are not directly cooled. The resulting higher exhaust pipe temperature has only a minor negative effect on the exhaust pipe life. The pipes are only enclosed in a hermetically sealed, cooled and insulated exhaust manifold with a very low cooling effect. Uncooled exhaust gases provide higher turbocharger power, higher engine power, and higher filling pressure, which makes the combustion chamber ventilation better during valve overlap and the thermal load on the piston and cylinder head compartments is reduced. The design with individual tubes joined by sliding elements permits thermal expansion of the exhaust pipes without heat stresses. At the same time, low-oxidation refractory steel is used, e.g. stainless steel EN 1.4435 or EN 1.4841, provides a long service life. The seals between the manifold are durable, significantly reducing the thermal deformation forces that would otherwise destroy the seal, significantly reducing the engine and exhaust. The partially sealed joints between the exhaust pipes allow the gases to escape into a hermetically sealed, cooled and insulated exhaust manifold until sufficient back pressure is reached to prevent further leakage. The partially cooled and partially insulated structure of the exhaust manifold has a low outside temperature, which prevents excessive air temperature in the engine compartment. Due to the lower intake air temperature, the turbocharger gives the engine even more air, which adds further benefits in terms of power and fuel consumption.

Description of the pictures

Figure 1: A-A cross-section of an internal combustion engine cooled and insulated exhaust manifold.

Figure 2: Thicker sealing plate replaced by thinner sealing plate.

Figure 3: Longitudinal section B-B of the exhaust manifold shown in Figure 2.

Figure 4: Exhaust manifold pipe inserted through sliding element into adjacent pipe.

Figure 5: Exhaust manifold pipe inserted into a larger diameter pipe element.

Figure 6: Exhaust manifold pipe inserted into double slide element.

Figure 7: Solution without integrated engine cooler.

integrated (Figure 1).

Figure 1 is a cross-sectional view of a Ά-Ά cooled and insulated exhaust manifold of the internal combustion engine shown in Figure 3 with a engine coolant cooler

The integrated exhaust manifold includes a stronger sealing plate 1 whose free surface faces the internal combustion engine. Stronger sealing plate 1 can still be machined after welding to provide the flat surface required for sealing. Preferably, by means of an automatic welding process, on the other side of the sealing plate 1 is a welded motor coolant tank consisting of thinner plates 12, 13 and 14. The plates 1, 12, 13 and 14, welded together with welds 8, constitute the coolant vessel fluid 17. At the top of the engine coolant container, a pipe 15 with an internal thread 18 and a sealing surface 16 is welded to the plate 12 on the plate 12, thereby enabling the insertion of the engine coolant closure 17 (not shown in the figures). ). A heat exchanger 21 is installed between the natural environment water and the engine coolant in the upper portion of the coolant tank. Details of the heat exchanger are shown in Figure 3. Exhaust manifold elbows 4 are inserted into the exhaust holes of sealing plate 1 or 2 and welded to sealing plate 1 or 47 by welds 3. At the opposite end, elbows 4 are welded to the exhaust pipe 5 and connected by further exhaust pipes 5 and 26, as shown in Figures 3 and 7. On the other hand, the exhaust pipe (4, 5 and 26) is located in the high pressure exhaust chamber 46, protected by a tightly fitting plate 7, welded to plate 13 by welds 8. A little farther outward, a panel 9 aligned with plate 14 and welded to plate 13 by welds 8. A narrow space between plates 7 and 9 is filled with gaseous, solid or liquid insulating material, thus improving the exhaust manifold pipe insulation. The tubes 6 are inserted into the holes in the thicker sealing plate 1 and into the holes in plates 7 and 9. The tubes 6 are welded to the thicker sealing plate 1 and plate 7 and 9 by welds 8, with the screws 11 located in the tubes 6, and, by means of suitable nuts 10, the complete exhaust manifold together with the integrated engine coolant cooler is secured to the cylinder heads. Welded longitudinal plates 48 and 49 improve cooling efficiency by directing the flow of refrigerant through the pipes of the engine coolant cooler.

In Figure 2, the thicker sealing plate 1 is replaced by a thinner sealing plate 47, while the light cast 2 is cast and machined on the sealing surface. This solution preserves the necessary rigidity of the sealing surface without the hassle of welding thicker and thinner plates together.

Figure 3 shows a longitudinal section of the B-B exhaust manifold of Figure 2 according to the invention. The exhaust pipe 5 welded to the elbows 4 is connected to the adjacent exhaust pipe 5, which is also welded to the elbows 4 according to the designs of Figures 4, 5 and 6 by means of a partially sealing flexible joint 35 (or 41 and 42). with joint 35 (41 or 42) and further connected to the exhaust manifold assembly pipe 26. Pipe 26 is tightly welded to the pipe 27 by welds 8, and to the exhaust gasket 28. All exhaust manifold components 4, 5 and 26 allow by means of flexible joints 35 (as well as 41 and 42 respectively) free thermal expansion of the exhaust manifold components; despite the high exhaust temperature. Such a design results in low thermal stresses and deformation of the exhaust manifold components. A modest proportion of exhaust gas escaping through partially sealed joints 35 (as well as 41 and 42 respectively) is trapped in the sealing space 46 by the cooled and insulated outer jacket of the exhaust manifold surrounded by panels 1 (Figure 1), 13 and 7 (Figure 1). However, even this minimum gas leakage is almost completely interrupted when the higher pressure in the sealed, cooled and insulated chamber is established 46. The internal combustion engine coolant enters the exhaust manifold through the inlet 34 of the pipe 24 welded to the plate 12 by weld 8. The refrigerant circulates around the plate 13, being further directed by plates 39 and 45, which are welded to the plate 13 by welds 8 and affect the direction of flow of the refrigerant. On the side of the knee 4 and the pipes 5 of each exhaust outlet, the pipes 6 between the plates 7, 14 and 1 (as shown in Figure 1) are welded to protect the screws 11, tightened by the nuts 10, from excessive heat (both shown in Figure 1). , but also contribute to the rigidity of the entire structure. This design allows for the use of long screws 11 that allow for suitable elongation, thereby enabling secure tightening of the exhaust manifold gasket not shown in the figures. The outer plate 12 is welded to the thicker exhaust gasket 28, to the heat exchanger rings 30 and 21 and to the coolant outlet pipe 23 to the coolant outlet 33. The heat exchanger pipes 19 are secured to the heat exchanger plates 20 and 29 and sealed with the ring seals 38 to the heat exchanger rings 21 and 30. Natural water from the environment enters the heat exchanger pipes through the heat exchanger covers 22, tightly attached to the heat exchanger rings 21 and 30. The retaining screws for the heat exchanger cover 22 'are not shown. Pipe 27 is welded to both the exhaust gasket 28 and the plate 13.

Figure 4 shows an exhaust manifold pipe 5 inserted through the sliding element 35 into the next-adjacent pipe 5. This partially sealed joint allows the exhaust gases to flow freely through the pipes 5, compensating for thermal expansion by its free axial motility. both pipes. Exhaust gases generate backpressure in chamber 46 as shown in Figures 3 and 7. When counterpressure is established, the leakage is neutralized and reduced to a negligible level.

Figure 5 shows an exhaust manifold pipe 5 inserted through a sliding pipe element of a wider diameter 41. An adjacent pipe 5 enters the pipe 41 through a tapered end 35 of the pipe 41. These partially sealed joints allow the exhaust gas to flow freely through the pipes 5, however, they compensate for the thermal expansion of both pipes. Exhaust gases generate backpressure in chamber 46 as shown in Figures 3 and 7. When counterpressure is established, the leakage is neutralized and reduced to a negligible level.

Figure 6 shows an exhaust manifold pipe 5 inserted into a double slide element 35 of the pipe 42. The pipe 42 is welded to the adjacent pipe 5 by welds 8. This partially sealed joint allows the exhaust gases to flow indefinitely through the pipes 5 while compensating for heat elongation of both tubes. Reduced leakage of exhaust gases creates backpressure in chamber 46, as shown in Figures 3 and 7. When backpressure is established, the leakage to chamber 46 is neutralized and reduced to a negligible level.

Figure 7 shows a similar solution, but without an integrated engine coolant cooler. Natural water or engine coolant 34 enters cooling zone 17 (Figures 1 and 2) through inlet pipe 24. Natural water or engine coolant circulates above plate 13 and below it to outlet 43 through pipe 44. In the case of natural water cooling, said outlet installed near the sealing plate 28 of the turbine charger. Outstanding natural water can be used to cool the turbine charger or enter directly into the exhaust knee. Neither is shown in Figure 7. In the case of engine coolant exhaust cooling, said coolant exits the exhaust manifold 43 via pipe 44. On both sides of each exhaust knee 4 of the exhaust pipes 5, there are welded pipes 6 between the exhaust gases 46. plates 7, 14 and 1 (as shown in Figure 1) that protect against excessive heat the screws 11, tightened by nuts 10 (both can be seen in Figure 1), while contributing to the rigidity of the overall structure. This design allows for the use of long screws 11 that allow for suitable elongation, thereby enabling secure tightening of the exhaust manifold gasket not shown in the figures. The outer plate 12 is welded to the thicker exhaust gasket 28. Threaded coolant drain pipe 48 with a drain plug not shown in Figure 7 can be opened to allow the coolant to drain.

Claims (7)

Patent claims Exhaust manifold for an internal combustion engine for both intake and pressure-filled internal combustion engines, which collects exhaust gases from the cylinder heads and discharges them into the exhaust pipe, the exhaust knee or the exhaust driven turbine charger, characterized in that The exhaust manifold is preferably made of stainless steel welded construction and consists of segments of an internal exhaust pipe consisting of at least two elerrients' (5), preferably made of I \ Refractory low-oxidation steels, preferably stainless steel EN 1.4435 or EN 1.4841, interconnected by longitudinally movable joints (35) and fixed to the engine side sealing plate (1) by an inlet end, with an outlet part and the reservoir to the exhaust outlet sealing plate 28, said inner exhaust pipe being hermetically sealed in a pressurized exhaust manifold (13, 1, 7) filled with exhaust gas (46) with an insulated outer surface (9). exhaust manifold and engine coolant (17) cooled> outer surfaces (12, 14, 1, 28) of the exhaust manifold. Exhaust manifold according to claim 1, characterized in that the engine coolant cooler is integrated into the structure, preferably between the plates (12 and 13). Exhaust manifold according to claims 1 and 2, characterized in that the engine coolant cooler is not integrated in the structure of the exhaust manifold. Exhaust manifold according to claims 2 and 3, characterized in that natural water from the environment or engine coolant is used to cool the parts of the exhaust manifold structure. Exhaust manifold according to claims 1 to 4, characterized in that fusible joints are used instead of partially sealed joints (35). Exhaust manifold according to claims 1 to 5, characterized in that the pipes 6 are used for thermal protection of the screws (11). Exhaust manifold according to claims 1 to 6, characterized in! that the length of the screws (11) exceeds the width of the exhaust manifold structure. Exhaust manifold according to claim 1, characterized in that the plate (2) is cast from light cast iron onto the panel (47) of the exhaust manifold structure with a thickness of at least 3 mm.