WO2014037145A1

WO2014037145A1 - Internal combustion engine with a crankcase

Info

Publication number: WO2014037145A1
Application number: PCT/EP2013/065521
Authority: WO
Inventors: Matthias Greiner
Original assignee: Robert Bosch Gmbh
Priority date: 2012-09-06
Filing date: 2013-07-23
Publication date: 2014-03-13
Also published as: DE102012215778A1

Abstract

The invention relates to an internal combustion engine comprising a crankcase (43) in which a crankshaft (49) is rotatably mounted, to which crankshaft at least one connecting rod, which bears a piston that is displaceable in a cylinder bore, is attached, a conveyor device being provided for conveying, in particular, fuel, and the conveyor device being fitted to the internal combustion engine and being driven by a shaft of the internal combustion engine. An internal combustion engine is provided which has a conveyor device, in particular, for fuel, which conveyor device can be fitted to the internal combustion engine cost-effectively with little space or weight requirements. This is achieved because the shaft is a balance shaft (3, 4, 44) that compensates for forces of inertia and moments of inertia caused by the operation of the internal combustion engine.

Description

description

title

The invention relates to an internal combustion engine with a crankcase, in which a crankshaft is rotatably mounted on which at least one piston which can be moved in a cylinder bore connecting rod is articulated, wherein a conveyor for conveying in particular fuel is provided, and wherein the Conveyor is attached to the internal combustion engine and driven by a shaft of the internal combustion engine.

State of the art

Such an internal combustion engine is known from DE 10 2008 008 259 A1. This internal combustion engine is designed as an air-cooled internal combustion engine and has been converted to a common-rail injection system with slight changes from a diesel internal combustion engine with a conventional injection system. For this purpose, designed as a high-pressure pump conveyor for fuel is arranged on the front side of the internal combustion engine. This high-pressure pump has a housing bearing a roller tappet, which is fastened to the crankcase, and wherein the roller tappet of the high-pressure pump cooperates with at least one additional conveyor cam on a gas exchange camshaft of the internal combustion engine. Another internal combustion engine is known from DE 10 2006 007 421 A1.

This internal combustion engine has an oil pan support frame, which is mountable between the crankcase and an oil pan. The oil pan support frame serves on the one hand for stiffening the crankcase, for example when installing the internal combustion engine in agricultural machines and on the other hand, it is possible to install a mass balancing gear in the oil pan support frame. This mass balancing transmission makes it possible, depending on the design of the internal combustion engine with respect to the number of cylinders and the arrangement of the cylinder to compensate for the occurring free forces and free moments of each first order and second order. The invention has for its object to provide an internal combustion engine, which has a conveyor, in particular for fuel, which can be inexpensively installed on the internal combustion engine in a small footprint and system weight. Disclosure of the invention

Advantages of the invention

This object is achieved in that the shaft is a balancing shaft for balancing caused by the operation of the internal combustion engine mass forces and / or mass moments. At least one balancer shaft is standard today in particular four-cylinder series internal combustion engines, which are used for driving motor vehicles, agricultural machinery and / or construction machinery. The storage of such a balance shaft is dimensioned sufficiently that it can absorb the forces and moments caused by the conveyor without changes. As a result, need not be used for the drive of the conveyor own drive shaft, in particular in the form of a camshaft. As a result, the space required for the conveyor over conventional solutions is reduced and in addition can by eliminating a separate

Shaft to drive the conveyor system weight of the corresponding internal combustion engine can be lowered. In addition, such a trained internal combustion engine can be produced more cheaply alone by the elimination of an additional wave.

In a further development of the invention, the conveyor is a high-pressure pump. In a further embodiment, this high-pressure pump is part of a common-rail injection system of an internal combustion engine in which the high-pressure pump fills a high-pressure accumulator with fuel and the fuel is taken from the high-pressure accumulator by fuel injectors for injection in associated combustion chambers of the internal combustion engine. In a further embodiment of the invention, the balance shaft is part of a mass balance shaft turn. Such a mass balance shaft plane generally has two counter-rotating shafts, which are driven by the crankshaft of the internal combustion engine, in particular via gears. In this case, the first balancer shaft is normally driven directly by the crankshaft at half the crankshaft speed, while the second balancer shaft is driven by an intermediate gear to reverse the direction of rotation of the crankshaft or directly from the first balancer shaft.

In a further development of the invention, the balance shaft and / or the mass balance shaft plane are attached to the crankcase. The balancer shaft is often arranged laterally on the crankcase, so that it is easily accessible from the conveyor together with optionally an adaptation housing and also easy to install.

In a further development of the invention, the balancer shaft and / or the mass balance shaft plane is integrated into an oil sump of the internal combustion engine or installed in a self-described Ausgleichshel- lengehäuse described in more detail below, which in turn can protrude into the oil sump. In this case, the mass balance shaft plane can be designed, for example, as a so-called Lanchester mass balance shaft gear, wherein two balancing shafts are installed in such a mass balance shaft plane. Such a balancer shaft and / or such a mass balance shaft transmission already has a sufficiently robust bearing, so that an additionally occurring peak torque, which is in the range of about 70 Newton meters from the conveyor in the form of a high-pressure pump, can be easily absorbed. Incidentally, the mass balancing shaft set thus formed can also be mounted outside the oil sump, for example laterally on the internal combustion engine.

In a further embodiment of the invention, the balance shaft and / or the mass balance shaft plane are installed in a balance shaft housing. Again, in an advantageous embodiment, the balance shaft housing is made of aluminum. This embodiment is inexpensive and can be implemented with a low system weight. In a further embodiment of the invention, a vacuum pump is arranged in the area next to the conveyor. A vacuum pump is needed in particular when using the internal combustion engine in vehicles to enable, for example, a vacuum generation for a brake booster.

In a further development of the invention, a low-pressure fuel pump is arranged in the area next to the conveyor. A low-pressure fuel pump is used for supplying fuel to the high-pressure pump, wherein the low-pressure fuel pump promotes the fuel from a tank optionally via a filter device to the high-pressure fuel pump.

In a further embodiment of the invention, the conveyor on an electrically operated suction valve. In principle, the suction valve can also be designed as an automatically opening and closing (mechanical) suction valve, but the electrical control of the electrically actuated suction valve by the direct integration of the conveyor to the internal combustion engine via the correspondingly supplemented electronic engine control unit is easily possible.

Further advantageous embodiments of the invention are described in the drawings, are described in more detail in the embodiments illustrated in the figures of the invention.

Brief description of the drawings In the drawings:

FIG. 1 is a sectional view of a balance shaft gearbox installed in an oil sump of an internal combustion engine, to which an additional conveying device is attached;

Figure 2 is a sectional view of a balancer shaft which is mounted laterally on a crankcase of an internal combustion engine and wherein a conveyor is driven by the balancing shaft and FIG. 3 shows a further sectional view of a balance shaft according to FIG. 2 in the direction of a crankcase of an internal combustion engine.

Embodiment of the invention

Figure 1 shows an oil pan 1 of an internal combustion engine, wherein in the oil pan 1, a mass balancing gear 2 is installed to compensate for the caused by the operation of the internal combustion engine mass forces and / or mass moments. The mass balance shaft gearbox 2 has a first balancing shaft 3 and a second balancing shaft 4. The first balance shaft

3 is driven by an intermediate gear from the crankshaft of the internal combustion engine by means of a drive gear 5. The first balance shaft 3 has an output gear 6 arranged approximately centrally on the first balance shaft 3, which meshes with a shaft drive gear 7 arranged at the same point on the second balance shaft 4. The transmission ratio between the first balance shaft 3 and the second balance shaft 4 is normally 1: 1. The intermediate gear, via which the first balancer shaft 3 is driven by the crankshaft, is provided in order to bridge a height offset of the mass balancing shaft gear 2 to the crankshaft and can therefore also be omitted. In principle, the drive of the balance shafts 3, 4 individually or in combination can also take place via a chain drive or a toothed belt drive.

Of the two balance shafts 3, 4, a balancer shaft rotates in the direction of rotation of the crankshaft and the second balancer shaft in the opposite direction to the crankshaft. Such mass balance with two balance shafts is known under the technical term Lanchester compensation and installed, for example, in four-cylinder internal combustion engines. The mass balance shaft gear 2 is installed in a balance shaft housing 8, which projects into the oil pan 1 or else is integrated directly into the oil pan 1. The balance shaft housing 8 is preferably made of cast aluminum and in turn preferably bolted to the crankcase of the internal combustion engine. This results in the possibility of installing the mass balance shaft gear 2 optionally on an internal combustion engine. The first balance shaft 3 and the second balance shaft 4 each have two bearing points 9a, 9b, which comprise oil-lubricated plain bearing shells 10a, 10b. The plain bearing shells 10a, 10b have oil guide holes 1 1 a, 1 1 b, with in the

Balanced shaft housing 8 recessed oil supply channels 12a, 12b are connected. In the area next to the output gear 6 and the shaft drive gear 7, the first balance shaft 3 and the second balance shaft 4 each have a balance weight 13a, 13b, preferably as a one-sided cast on the respective balance shaft 3, 4 material accumulation of a metallic material, in particular a cast material , manufactured balancing shaft 3, 4 consists. In the exemplary embodiment, the second balance shaft 4 in the area adjacent to the bearing 9a and the shaft drive gear 7, a cam 14 which may be formed as a single or multiple cam. On this cam 14 rolls a roller 15 of a roller tappet 16 of a designed as a high-pressure pump 17 conveying device for fuel. The high pressure pump 17 is part of a common rail injection system that delivers diesel fuel to a high pressure accumulator. In principle, however, the high-pressure pump 17 can also be part of an injection system that promotes gasoline fuel.

A housing part 19 accommodating the roller tappet 16 is integrated into the compensating shaft housing 8 and, in the exemplary embodiment, is flush with an opening 20 in the oil sump 1. The opening 20 is sealed off from the housing part 19 by a seal 21.

In the housing part 19 lubricating oil channels 22a, 22b are recessed. The lubricating oil passage 22a is connected to the oil supply passage 12a and an external port

23, which is connected via a further line with an oil filter, which is mounted on the internal combustion engine, connected. Lubricating oil is supplied to this oil filter, which is conveyed by an oil pump 24 which is arranged on the end side next to the high-pressure pump 17 and is likewise driven by the second balancing shaft 4. For this purpose, a suction channel 25 is inserted into the balance shaft housing 8, which opens into the oil pan 1 or connected to a further channel in the oil pan 1, which in turn opens onto the oil pan bottom. The pumped by the oil pump 24 lubricating oil is passed via a pressure line 26 in an external connection line to the oil filter. In this line, an oil cooler can also be installed in front of or behind the oil filter. These are

Lines, provided they are connected to the oil filter or oil cooler. are, led out in a suitable manner from the balance shaft housing 8 and the oil pan 1 and brought in again.

The roller tappet 16 has a roller shoe 27 carrying the roller shoe 27 in which an oil passage 28 for lubricating oil supply to be lubricated points of

Roller tappet 16 is inserted. The roller tappet 16 cooperates with a pump plunger 29, which is moved up and down in a plunger bore of a pump cylinder 30 during a rotational movement of the second balancer shaft 4 and which delimits a pump working space 31. The pump working space 31 has a lateral high-pressure port 32 with a built-in non-return valve, the high-pressure port 32 being connected to the high-pressure accumulator via a high-pressure line.

In extension of the pump plunger 29, a suction valve 34 is inserted in a screw-in stopper 33, which is screwed sealingly to the pump cylinder 30. The suction valve 34 has a suction connection 35 arranged above the high-pressure connection 32, via which fuel is supplied to the suction valve 34. The suction valve 34 has an electrically actuated valve pin 36, via the controlled fuel in the pump chamber 31 can be supplied. But the valve pin 36 may also be spring-loaded and thus be formed mechanically automatically opening and closing. The suction connection 35 is connected via a fuel line (not shown) to a fuel connection 37 of a low-pressure fuel pump 38, which can be attached as an external pump or to the oil sump 1 or an end cover 39 and can be designed, for example, as an electrically operated gear pump.

In addition to the oil pump 24, a vacuum pump 40 is mounted on the balance shaft housing 8 or the oil pan 1, which is also actuated by the second balancing shaft 4. The vacuum pump 40 has a connection 41 which is connected, for example, to an externally installed brake booster of a vehicle in which the internal combustion engine is installed.

As an alternative to the installation of the high-pressure pump 17 on the second compensating shaft 4, this can also be done on the opposite side on the first compensating shaft 4. be arranged equal shaft 3, which is represented by the dashed block 18.

In the embodiment according to FIGS. 2 and 3, the high-pressure pump 17 is installed in an adaptation housing 42, wherein the adaptation housing 42 is attached laterally to a crankcase 43. The adaptation housing 42 simultaneously constitutes an outer housing cover of a balance shaft 44, wherein the balance shaft 44 has the same structure as the second balance shaft 4 according to the embodiment of FIG. In this case, however, the shaft drive gear 7 of the balance shaft 44 is optionally driven by an intermediate gear from the crankshaft or other shaft of the internal combustion engine.

The high-pressure pump 17 has a structure largely corresponding to the structure of the high-pressure pump 17 known from FIG. 1, so that only essential distinguishing features are described here.

In the adaptation housing 42, an oil supply passage 45 is inserted, the oil supply channels 46 a, 46 b supplied with oil. The oil guide channels 46a, 46b are suitably connected to the oil guide holes 1 1 a, 1 1 b of the bearings 9 a, 9 b of the balance shaft 44 and the recessed in the roller shoe 27 oil passage 28. In this high-pressure pump 17, the suction port 35 and the high-pressure port 32 are arranged on opposite sides of the pump cylinder 30, while again the suction valve 34 in a

Screwed plug 33 is inserted. In contrast to the exemplary embodiment according to FIG. 1, here the suction valve 34 is designed as an automatically acting mechanical suction valve, in which the valve pin 36 is held in the closed position by a spring 47 when the high-pressure pump 17 is at rest.

FIG. 3 shows a plan view of the crankcase 43 of the internal combustion engine in the region of the adaptation housing 42 to be mounted. The balance shaft 44 is arranged in the region of the parting line between the crankcase 43 and the adaptation housing 42. In the area next to the bearings 9a, 9b of the balance shaft 44 threaded holes 48 are embedded in the crankcase 43, in the mounting screws for mounting the adapter housing 42nd can be screwed to the crankcase 43. In the parting plane between the adaptation housing and the crankcase 43, a seal can be inserted. Parallel to the balance shaft 44, a crankshaft 49 of the internal combustion engine is mounted in the crankcase 43, which may have balancing weights 50. The balance weights 50 are to compensate for mass forces of the first

Order determined.

A balancing shaft 44 may be arranged on only one longitudinal side of the crankcase 43 of the internal combustion engine or else preferably on both opposite longitudinal sides of the crankcase 43 of the internal combustion engine, so that a Lanchester compensation is also realized in this embodiment.

Furthermore, the high-pressure pump 17 may be aligned at an angle to the engine cylinder axis, whereby further space advantages can be achieved.

Claims

claims

1 . Internal combustion engine with a crankcase (43) in which a crankshaft (49) is rotatably mounted on which at least one piston rod movable in a cylinder bore connecting rod is articulated, wherein a conveyor for conveying in particular fuel is provided, and wherein the conveyor the internal combustion engine is mounted and driven by a shaft of the internal combustion engine,

characterized in that the shaft is a balancing shaft (3, 4, 44) to compensate for caused by the operation of the internal combustion engine forces and / or mass moments.

2. Internal combustion engine according to claim 1,

characterized in that the conveyor is a high-pressure pump (17).

3. Internal combustion engine according to claim 2,

characterized in that the high pressure pump (17) is part of a common rail injection system.

4. Internal combustion engine according to one of the preceding claims,

characterized in that the balance shaft (3, 4, 44) is part of a mass balance shaft gear (2).

5. Internal combustion engine according to one of the preceding claims,

characterized in that the balance shaft (3, 4, 44) and / or the mass balance shaft gearbox (2) is attached to the crankcase (43).

6. Internal combustion engine according to one of the preceding claims,

characterized in that the balance shaft (3, 4, 44) and / or the mass balance shaft gear (2) is integrated in an oil pan (1) of the internal combustion engine.

7. Internal combustion engine according to one of the preceding claims,

characterized in that the balance shaft (3, 4, 44) and / or the mass balance shaft gear (2) in a balance shaft housing (8) is installed.

8. Internal combustion engine according to claim 7,

characterized in that the balance shaft housing (8) is made of aluminum.

9. Internal combustion engine according to one of the preceding claims,

characterized in that in the area next to the conveyor a vacuum pump (40) is arranged.

10. Internal combustion engine according to one of the preceding claims,

characterized in that in the area next to the conveyor a low-pressure fuel pump (38) is arranged.

1 1. Internal combustion engine according to one of the preceding claims,

characterized in that the conveyor has an electrically operated suction valve (34).