EP1079080A2 - Oil cooled internal combustion engine - Google Patents

Abstract

The engine has an engine block with a cylinder housing and cylinder head and a cooling sleeve carrying an oil flow and contg. an annular chamber (10) enclosing a piston working chamber and a head chamber (11) almost fully covering the working chamber at the end, whereby the head chamber and annular chamber are directly connected. The oil flow passes from the cooling sleeve via an outlet opening (13) in the head chamber into a return chamber (14) enclosing at least one cylinder (6) including the annular chamber.

Description

The invention relates to an internal combustion engine with an engine block, the one Cylinder housing and a cylinder head covering the cylinder housing and has a cooling jacket through which oil flows, the cooling jacket, an axially at least partially surrounding the working space of a piston Annulus and the work area almost completely on the front covering head space, the head space and the annular space in are in direct contact with each other.

motorfremde" Wasser mit sich bringt. Außerdem ist die Betriebstemperatur wassergekühlter Motoren wegen der physikalischen Eigenschaften des Kühlmittels auf etwa 95°C begrenzt, was den Grad der Energieumsetzung und der Schadstoffreduzierung limitiert.Oil-cooled internal combustion engines of this type are known in particular among diesel engines. In the known engines, the cylinder block in the immediate vicinity of the cylinders is provided with cooling rooms through which a stream of oil flows to remove the heat of combustion. The main advantage of using oil as a coolant is that there is no need for cooling water. Dispensing with cooling water goes hand in hand with solving many of the problems that actually exist

This means that the operating temperature of water-cooled engines is limited to around 95 ° C due to the physical properties of the coolant, which limits the degree of energy conversion and the reduction in pollutants.

A disadvantage of the previously known oil-cooled engines is that the cooling can be controlled relatively poorly. In the known engines, the individual parts may heat up differently and thus tension and even cracks in the engine block. At the same time, it can occur because of locally occurring hot spots "lead to partial coking and thus contamination of the cooling oil, which leads to an impairment of the cooling performance.

The object of the present invention is an oil-cooled internal combustion engine to create that operate even at comparatively high temperatures leaves. It is also an object of the invention to provide an internal combustion engine from simple construction and high reliability to create a good Heat regulation made possible by controlling the cooling oil flow and thus an optimization of the energy conversion allowed.

These tasks are by the internal combustion engines according to claim 1 and Claim 7 solved.

A central idea of the invention is that the invention Engine with its multi-chamber system for oil guidance surrounding the cylinders and oil absorption a precise control of the temperature by controlled Oil flow and good heat dissipation. This peculiarity of the engine allows comparatively high operating temperatures of up to 140 ° C or allow about it. For such high operating temperatures, however Use of a metal gasket as a cylinder head gasket is essential.

For the implementation of controlled cooling, it is first important to Working space (displacement) of the cylinder as completely as possible with one To envelop the cooling jacket. For this purpose, the cooling jacket on the one hand has a Displacement of the cylinders coaxially at least partially surrounding the annular space, the headspace that covers the combustion chamber on the front continues. The head space is designed so that it the respective Cylinder head and the combustion chamber arranged in it almost completely covered. The headspace is only of the necessary bushings for the injector or the valves are broken. According to the invention occurs Oil flow from the through an opening made in the head space Cooling jacket out in a return space, the return space the Fully surrounds the cylinder including the annulus. So is one optimal control of heat dissipation possible. Also wear the envelope Cooling jacket and the return space to reduce noise.

In a particularly simple embodiment, the annular space and the Head space at the location of the cylinder head gasket directly into each other and form a closed cooling jacket of approximately constant width. So becomes a homogeneous flow of the oil without strong pressure fluctuations reached due to bottlenecks. The return space is advantageous Arranged parallel to the piston and forms the lowest point Oil sump. The oil runs down its vertical walls and cools before going to a collection room at the lowest point due to gravity, especially in the oil sump. In a hydrodynamically special inexpensive and easy to implement embodiment are all cylinders of the Motors surrounded by a common return space. In the return space At the same time, gases from compression losses flow up into the Valve cover and can be removed from there.

In a particularly advantageous embodiment, the oil is from a promoted in particular electrically operated pump. The oil flow occurs from below via a provided near the bottom of the annulus Entry opening into the cooling jacket and is countered by gravity promoted the headspace, where it over the highest possible Exit opening leaves. A special one can be used for the cooling oil Circulation can be provided so that oil with special properties for Cooling can be used. However, it is particularly simple and therefore advantageous, the engine oil provided for lubrication of the engine also for To use cooling.

Another essential idea of the invention is that in one common collecting space oil collected in a in the engine block to transport the integrated storage container. This is according to the invention Storage container designed as a chamber in the engine block and not as known as a separately arranged container, for example as an oil pan, outside of Engine block arranged. It is advantageous if the pantry is all Surrounds cylinders as a continuous space. A pantry for Cooling oil and / or another storage chamber for lubricating oil can be provided. If the lubricating oil is used as cooling oil, a common one is sufficient Pantry off. Advantageously, the pantry sits in the Cylinder head, in the valve cover and in the crankcase and thus surrounds the Cylinder completely.

The storage chamber integrated in the engine block and surrounding the cylinders can also be used with conventional motors with water cooling. In general, such a pantry offers several advantages. First of all Construction space saved by the arrangement according to the invention. Another The advantage is that the coolant jacket surrounding the return chamber, which the Pantry forms, contributes to damping and thus the running noise and Vibrations of the engine can be reduced. In this way, the Noise level from diesel engines to the level of gasoline engines be reduced.

In addition, such a pantry ensures that even with strong Lateral accelerations, such as those found in extreme cornering occur, there is always sufficient coolant at the intake opening. This eliminates the risk of dry running. Even at times inclined vehicles such as construction machinery and sailing boats Storage chamber according to the invention has considerable advantages. The serve External surfaces of the storage chamber for cooling the oil contained therein.

To operate this engine at high temperatures is another central idea of the invention, the cylinder head gasket made of metal manufacture. The metal seal is also independent of the exact one Formation of the cooling jacket is a special part of the invention the metal gasket according to the invention ensures that the engine also Temperatures above 100 ° C, at which the cylinder head gaskets are made burn conventional material or burn up, can be operated. An oil-cooled engine sealed with the metal gasket that also is equipped with the completely surrounding cooling jacket, can be Operate temperatures of 150 ° C. At these operating temperatures a reduction in fuel consumption of up to 25% with a achieve correspondingly lower exhaust emissions. The one because of the higher ones Temperatures of more complete combustion cause less Particle emission especially in diesel engines. Finally, on the one hand the high temperature of over 140 ° C the combustion process significantly improved and on the other hand the lower temperature difference means i.e. the lower energy dissipation, better use of energy.

The metal seal is advantageously formed by individual metal rings, which are formed from wire and in a corresponding groove around the opening of the Cylinders are placed. In this way, each cylinder is separately against the Sealed cylinder head. The metal rings can be easily and Manufacture and assemble inexpensively by machine. When screwing on the Cylinder head they are pressed together and deformed. If the Cylinder head is made of aluminum, the comparatively harder press Metal rings in the material

The metal seal is advantageously cooled. This cooling can be Realize particularly easily with the sealing rings by using a special in particular wedge-shaped cooling chamber is provided, via which the Oil flow can be brought up to the sealing ring. It is particularly easy if the Sealing rings are dimensioned so that a certain distance between the Cylinder housing and the cylinder head remains so that the oil in the Clearance can flow around the sealing ring. In this embodiment the cooling chamber from the mutually facing end faces of the Cylinder head and the cylinder block above and below and from the sealing ring limited laterally.

In summary, the invention and its advantages can be summarized as follows represent: The engine consists essentially of four parts, namely the Cylinder crankcase, the crankcase lower part, the cylinder head and the Cylinder head cover. It differs from conventional motors in that that the four components were enclosed on all sides by two additional chambers are. The first inner chamber, the cooling jacket of the cylinder and the Encloses cylinder head, forms the return space for that in the cylinder head escaping hot cooling oil. This chamber opens into the oil sump. Another The function of this chamber is to vent the crankcase from penetrating combustion gases that rise up in this chamber and in the area of the cylinder head cover in the calm state to the outside be directed. Due to the large area of the chamber, there are few Flow velocities that cause turbulence and mixing of the Prevent gases with the engine oil. That on the inside and outside Cooling oil that runs off the chamber wall releases part of the heat it carries along, before it is sucked off in the lower part of the crankcase. The return space according to the invention completely encloses the area of the engine in which the mechanically generated noises as well as the combustion noises arise, and thus causes an acoustic separation to the outside.

The return chamber is an inner chamber on all sides from an outer chamber enclosed. This outer chamber serves as a pantry. That about the Oil flowing back into the collecting space is sucked out from there and over the cylinder head cover, which contains an air separation labyrinth, into the Pantry returned. The oil is transferred from the pantry to the known way by means of a pump to the bearings and in the cooling jacket pumped. Since the pantry encloses all noise-emitting parts, further vibration and sound absorption is achieved.

The entire outer surface of the engine is used for cooling and radiation Engine heat, which is a small size of the external radiator enables. Through the chambers enclosing the engine with their inner and outer walls, will have great stability and rigidity throughout Engine design achieved. All components can be made with thinner walls be constructed without affecting the torsional rigidity. The outer supply chamber becomes the lubrication and Cooling required fresh oil via a pump to the supply points promoted. Because of the outer chambers surrounding the motor as a whole, the engine can also be operated in extreme inclined positions without the Oil supply is affected.

A major advantage of this engine is the high temperature operation that is achieved the waiver of water as a cooling medium becomes possible. By oil cooling came an average operating temperature of about 150 ° C to be approved. Around to be able to operate the engine at this operating temperature is limited to Classic cylinder head gasket dispensed with and only one in a groove inserted metal ring seal used. This metal ring is also through a circumferential gap oil-cooled and therefore mechanically and thermally resilient. The ring seals the upper edge of the cylinder against the cylinder head from. Other seals are only for the four main housing parts and the Crankshaft required and correspond to known silicone or Shaft seals.

The high-temperature operation favors the thermal budget of the engine and leads to better combustion processes, as well as to a more effective one Use of fuel and, consequently, lower pollutant emissions. In connection with the multi-chamber system, a diesel engine reaches Noise and vibration values that come close to an Otto engine. Through the described construction, which has a significant improvement in rigidity compared to the classic engine design, will also be a higher one Lifetime of the moving parts achieved. Also the oil tightness after Outside is influenced favorably.

Figur 1

einen vertikalen Schnitt durch einen ölgekühlten Motorblock,

Figur 2

einen horizontalen Schnitt durch einen Zylinderkopf und

Figur 3

eine Zylinderkopfdichtung.

An embodiment of the motor according to the invention is described in more detail below with reference to FIGS. 1 to 3. Show it:

Figure 1

a vertical section through an oil-cooled engine block,

Figure 2

a horizontal section through a cylinder head and

Figure 3

a cylinder head gasket.

The engine block shown in Figure 1 is known to consist of four Components together. So it has a central cylinder housing 1 and a cylinder head 2 covering the cylinder housing. Under the Cylinder housing 1, a crankcase 3 is arranged and on the A valve cover 4 is placed on cylinder head 2. A piston 5 runs within the Cylinder housing 1 in a cylinder liner 6 and is is known to be sealed by piston rings against the liner 6. The Liner 6 thus encloses the displacement of the piston 5. Also shown are the valves 7 known from conventional engines and the connecting rod 8, which engages the crankshaft 9.

According to the invention, the liner 6 and thus the displacement of the piston 5 surrounded by a coaxial annulus 10 which is from an oil flow to For cooling purposes. The annular space 10 settles in one Head space 11 continues, which is introduced into the cylinder head 2 and which Combustion chamber covered on the face. Form head space 11 and annular space 10 one the cylinder up to the bushings of the valves 7 and not shown injector completely comprehensive cooling jacket, being by a cylinder head gasket 12 designed as a combustion chamber gasket (see FIG. 3) made of metal is avoided that oil from the cooling jacket in the Combustion chamber enters. The oil used for cooling will later become too descriptively from a reservoir to the bottom of the annulus 10 fed through an inlet opening, rises in the annular space 10 with removal of the Heat generated in the cylinder to the cylinder head 2 and occurs in the Headspace 11 a. As can be seen from FIG. 2, the annular spaces 10 in FIG in this case, three cylinders connected to each other.

An outlet opening 13 is made in the dome of the head space 11, through which the oil escapes into the valve cover 4 along arrow A. From the Valve cover 4 runs the oil from gravity into a return chamber 14, the completely surrounds the cylinder including the annular space 10. To the Walls of this return space 14 runs down the oil, cools and collects on the floor in a provided in the crankcase 3 Collecting space 15. The collecting space 15 also collects the oil that emerges from the piston cooling nozzles and the plain bearings. The return space 14 is composed of merging chambers, which in the Cylinder head 2, the cylinder housing 1 and the crankcase 3 introduced are. It therefore completely surrounds the cylinder and the piston drive. How from As can be seen in FIG. 2, the return spaces 14 of the cylinders are located one below the other Connection and form a return chamber 14 surrounding the three cylinders.

From the collection space 15, the oil is electrically or mechanically operated pump 16 via a return line 17 into a storage chamber 18th pumped, it first freed of residues in a filter 19 and is additionally cooled by an oil cooler 20. The pantry 18 stands with the annular space 10 via a line, not shown, in connection, so that the oil by the pressure built up by the pump 16 from the Storage chamber 18 is pressed into the annular space 10. The pantry 18 is also housed in the engine block and in turn surrounds the complete Return space 14. It is made up of individual compartments both in the Crankcase 3, in the cylinder housing 1, in the cylinder head 2 and in the valve cover 4 continues. The oil collected in the storage chamber 18 is used for both Lubrication as well as used for cooling. The pantry 18 is via seals 23, which are made of rubber in this case, opposite sealed the outside space. Otherwise there are annular space 10, return space 14 and pantry 18 at the joints between the components of the Engine block in a connection caused by the gap.

Via a bypass line 21, which from the return line 17 directly into the Annulus 10 leads and switched on by means of a three-way valve 22 is, the processed oil can be directly from the collecting space 15 in the annular space 10 pumps. This reduced oil volume heats up faster, so that the Engine quickly reaches its operating temperature. The temperature of the engine is in a known manner from temperature sensors, not shown supervised. Due to the delivery rate of the pump 16 and the use of Bypass line 21 can then control the temperature of the motor well. The return line 17 continued behind the three-way valve 22 opens into an inlet 26 in the cylinder head. From the outside, the oil is above the system an inlet 27 can be supplied.

The operating temperature can be so in the engine according to the invention adjust so that it goes well above 100 ° C and can reach about 150 °. This is possible through the use of metal seals for the sealing between cylinder head and cylinder. In this case the metal seal is on Sealing ring 12 (Figure 3), which in a corresponding the cylinder bore surrounding annular groove 24 is inserted in the abutting surface of the cylinder housing 1. The sealing ring is squeezed directly by the screwed-on cylinder head 2 acted upon and thereby deformed. In the case of a cylinder head Aluminum is pressed in at the appropriate point. To the seal 12 to cool, the cooling jacket forms a cooling chamber 25 through which the Oil flow can be brought up to the sealing ring 12. The cooling chamber 25 is in this case of widening the gap between the Cylinder housing 1 and the cylinder head 2 are formed.

Claims (13)

Internal combustion engine with an engine block, which has a cylinder housing and a cylinder head covering the cylinder housing and which has a cooling jacket through which oil flows, the cooling jacket, an annular space (10) which at least partially surrounds the working space of a piston (5) axially and an almost the front of the working space has a completely covering head space (11), the head space (11) and the annular space (10) being in direct connection with one another,
characterized,
the oil flow enters the return chamber (14) via an outlet opening (13) introduced into the head space (11) and completely surrounds at least one cylinder (6) including the annular space (10). Internal combustion engine according to claim 1,
characterized in that the return chamber (14) opens into a collecting chamber (15) arranged in the lower crankcase part (3), the oil flow running into the collecting chamber (15) driven by gravity. Internal combustion engine according to one of claims 2 or 3,
characterized in that several return spaces (14) surrounding the individual cylinders (6) are connected to one another and form a common return space. Internal combustion engine according to one of the preceding claims,
characterized in that a storage chamber (18) is provided in the engine block, which holds a supply of fresh oil and completely surrounds at least one cylinder (6) and in particular all cylinders. Internal combustion engine according to one of the preceding claims,
characterized in that the pump (16) pumps the oil from the collecting space (15) into the storage chamber (18) via a return line (17). Internal combustion engine according to one of the preceding claims,
characterized in that the oil can be conveyed via a bypass line (21) from the return line (17) directly into the annular space (10). Internal combustion engine according to one of the preceding claims,
characterized in that the oil used for cooling is also used to lubricate the moving parts. Internal combustion engine with an engine block, which has a cylinder housing and a cylinder head covering the cylinder housing and which has a cooling jacket through which oil flows, the cooling jacket, an annular space (10) which at least partially surrounds the working space of a piston (5) axially and an almost the front of the working space has a completely covering head space (11), the head space (11) and the annular space (10) being in direct connection with one another,
characterized in that
that the cylinder head is sealed from the cylinder housing via a metal seal. Internal combustion engine according to claim 8,
characterized in that the metal seal is a sealing ring (12), in particular an O-ring, which lies in a groove (24) made in the front edge of the cylinder housing (1). Internal combustion engine according to claim 8 or 9,
characterized in that the cooling jacket has a cooling chamber (25) via which the oil flow can be brought to the sealing ring (12). Internal combustion engine according to claim 10,
characterized in that the cooling chamber (25) is delimited by the mutually facing end faces of the cylinder head (2) and the cylinder housing (1) and by the sealing ring (12). Internal combustion engine according to one of claims 8 to 11,
characterized in that the annular space (10) and the head space (11) merge into one another at the location of the combustion chamber seal and the cylinder head gasket (12) and form a closed cooling jacket enclosing the working space of the cylinder. Internal combustion engine according to one of claims 8 to 12,
characterized in that the oil flow enters the cooling jacket via an inlet opening provided at the bottom of the annular space (10) and leaves it via an outlet opening (13) made in the head space (11).

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