DE102008005226A1 - Internal combustion engine e.g. diesel engine, for motor vehicle, has crankshaft and bearing plates whose positions are changeable in degrees of freedom using adjusting device for changing compression ratios of engine - Google Patents

Abstract

The engine has a main shaft (1) and a crankshaft (2) that are supported by two bearing plates (4). The shafts are engaged with each other over transmission units (1'-3') e.g. gear wheels or duplex chains, that are provided at the shafts. The crankshaft is connected with a cylinder head unit (8) by defining compression ratios. Positions of the crankshaft and the bearing plates are changeable in degrees of freedom using an adjusting device (10) to change compression ratios of the engine and to influence the compression ratios by changing the position of the crankshaft and the bearing plates.

Description

The The invention relates to an internal combustion engine according to claim 1.

combustion engines are in a variety of different embodiments from the prior Technique known.

at an internal combustion engine (for example diesel or gasoline engine) becomes a fuel-air mixture in a cylinder / combustion chamber inflamed and burned. The by the development and temperature-related thermal expansion the combustion gases resulting pressure acts on a piston, the is moved by it.

At the Diesel combustion process, however, is unlike the gasoline engine no flammable air-fuel mixture supplied but exclusively Air. This air will be first highly compressed in the cylinder, whereby it heats up to about 700 to 900 ° C. In front the top dead center begins the injection and finest distribution of the fuel in the hot Air in the combustion chamber. The high temperature is sufficient to fuel starting from the surface to evaporate and ignite.

At the Otto combustion process, the fuel passes through a carburetor or over a (today usually electronically controlled) gasoline injection nozzle in the Combustion chamber of the engine. With the help of a spark plug, a short electric Flashover, the spark, generates the fuel-air mixture formed in the combustion chamber time exactly brings to the explosion. The combustion is generated in the relatively small combustion chamber a hot gas with high pressure (over 100 bar), which moves the piston in a straight line in the direction of the crankshaft drives. about The connecting rod, also called the connecting rod, will this movement in the implemented rotating motion of the crankshaft.

at an engine of the type of a piston internal combustion engine is so a piston during a work cycle shifted axially. This changes the volume in the cylinder. There are thus two extreme positions of the piston. These will designated upper and lower dead center. Do you put those on this If existing volumes in relation to each other so you get the compression ratio or in short, the compression of the engine.

In the context of combustion engines, the compression ratio is the ratio of the total cylinder space before compression to the remaining space after compression (see formula):

The compression ratio a gasoline engine, which is designed for example for regular gasoline, For example, it is 9.2: 1 or 14: 1. For diesel engines However, the compression is inherently higher, a typical value at Direct injection diesel is for example 19.5: 1.

adversely in the known from the prior art internal combustion engines however, that the compression ratio in internal combustion engines while of the engine operation can not be varied or regulated and the respective engine types thus to a certain type of fuel are fixed.

outgoing It is therefore an object of the present invention to propose an internal combustion engine, which avoids the disadvantages known from the prior art and for example optionally with diesel fuel, gasoline or a mixing ratio can be operated from fuels.

These Task is according to the invention with the Characteristics of claim 1 solved.

advantageous Further developments of the invention are part of the dependent claims.

According to the invention it is proposed to provide an internal combustion engine, in particular a series engine, for a motor vehicle, with at least a first shaft (main shaft) and a second shaft (crankshaft), wherein the shafts are mounted to each other via at least two bearing plates, and wherein the waves on the Waves provided transmission means are engaged, and wherein the second shaft (crankshaft) via suitable means with at least one cylinder head unit, under definition of a compression ratio in operative connection, and wherein the position of the second shaft (crankshaft) or the at least two bearing plates in at least one degree of freedom can be changed by means of an adjusting device, such that the compression ratio of the internal combustion engine can be changed or influenced by means of the change in position of the second shaft (crankshaft) or the at least two bearing plates. A change or influence on the compression ratio would have the advantage that, for example, a gasoline engine with conventional fuels could be operated as a diesel. Furthermore, the regulation of the compression and thus of the combustion pressure, the exhaust gas performance of the engine in question can be significantly improved. Gasoline engines could, for example, as a diesel with Ver consumption characteristics of diesel engines with improved exhaust gas properties.

A embodiment the invention provides that the adjustment medium or is directly in operative connection with at least one end shield, wherein an adjustment of the adjusting device is an adjustment causes the bearing plates. Preferably, several bearing plates be provided, which ensures the corresponding waves in the engine compartment to store. So can for example, for each Shaft three bearing plates should be provided, which are the shaft respectively at the beginning and Support end point and center. By adjusting the adjustment so also takes place an adjustment of the corresponding bearing plates or the second Shaft (crankshaft) to the main shaft.

A embodiment provides that the adjusting device of at least two against each other slidably mounted adjustment modules can be formed. Conceivable would be here For example, spindle, lifting or eccentric drives.

A another embodiment provides that the adjustment modules in the manner of a ramp construction can be trained wherein at least radially to the first shaft (main shaft), an adjustment slight horizontal and the other adjustment module, due to the horizontal Displacement of the one adjusting module, at least slightly vertical can be displaced. The design as a ramp construction would have that Advantage that a very accurate position change of the second shaft (crankshaft) could be done. The individual designed as a ramp adjustment modules could z. B. be formed by a horizontal displacement a first ramp part a vertical displacement, for example raise or lower, the second ramp part takes place. Such vertical displacement of the at least one adjustment module would have a direct effect on the compression ratio of the internal combustion engine, because by the shift the position of the second shaft (crankshaft) and thus the connecting rod or the working piston, more precisely of top dead center, within the cylinder head unit would. A such change the volumes within the cylinder head unit are effected simultaneously a change the compression ratio.

Conceivable is that the adjustment of the adjustment or the adjustment and thus the at least one bearing plate hydraulically, pneumatically or electromagnetically. For example, a connection would be conceivable for an existing hydraulic system in a motor vehicle, so that that at least one bearing plate of the second shaft (crankshaft) via, for example, oil pressure controlled Adjustment modules (for example, ramps) substantially radially to first wave (main shaft) varies vertically up or down which could be the end position of the piston to the combustion chamber in the cylinder head (as already explained above) changes.

The first wave (main wave) may be preferred, but by no means mandatory, be designed as a straight wave.

A sees further advantageous embodiment before that a third wave (intermediate wave) can be provided, the third wave (intermediate wave) between the first wave and second wave is arranged and over on the third Wel le (intermediate wave) provided transmission means, with the transmission means the first shaft (main shaft) and the second shaft (crankshaft) can be engaged. The use of a third wave (intermediate shaft) could, for example to realize a certain gear ratio be required or enough Distance to the main shaft to achieve, for example, a favorable position or Connection to the cylinder bank.

at the transmission means, For example, they can be gears. It is, however conceivable to resort to the use of chains, in particular duplex chains.

at a further embodiment of the invention can be provided that the at least two bearing plates relative to the first shaft (Main shaft) fixed and relative to the second shaft (crankshaft) or third shaft (intermediate shaft) adjustable, in particular vertically adjustable, are formed, wherein the fulcrum of at least two bearing plates through the longitudinal axis the first wave (main shaft) runs. It would be conceivable, for example each shaft end in a common, at the axial end of the waves arranged to store bearing plate, with the bearing plate, in a vertical position change, around the preferably fixed bearing point of the first shaft (main shaft) would move. While the vertical position of the first shaft (main shaft) would be fixed so would the second and each additional wave around the fulcrum of the fixed first Swivel the shaft (main shaft) around and adjust it in height leave as soon as the adjustment on at least one of the bearing plates would work.

in the The invention is based on only one embodiment illustrative drawings closer explained.

It shows:

1 the schematic functional diagram for achieving a variable compression in one Internal combustion engine in a first position;

2 the schematic functional diagram for achieving a variable compression in an internal combustion engine in a second position;

3 the schematic arrangement of the individual waves to each other.

1 shows the schematic functional diagram for achieving a variable compression in an internal combustion engine in a side view. The functional principle described here and simplified comprises a first shaft (main shaft) 1 , a second shaft (crankshaft) 2 and a third wave (intermediate shaft) arranged therebetween 3 , The respective shaft ends are in a bearing plate 4 (more bearing plates may be present, but are not shown) stored. About a bracket 5 is the first wave (main wave) 1 in the crankcase (not shown) stored. The pivot point D of the end shield 4 lies on the longitudinal axis of the first shaft (main shaft) 1 , The individual waves 1 . 2 and 3 are about transmission means 1' . 2 ' and 3 ' (here gears) engaged with each other.

The transmission medium 2 ' which on the second shaft (crankshaft) 2 is arranged, is about a connecting rod 6 with the piston 7 a cylinder head unit 8th in active connection. The area extending between the dashed line L and the upper piston surface 9 is defined as the compression ratio and describes in connection with internal combustion engines, the ratio of the entire cylinder space before compression to the remaining space after compression.

An adjusting device 10 acts directly with the end shield 4 together and is hereby designed in the manner of a ramp construction. A first adjustment module 11 is directly with the end shield 4 connected. A second adjustment module 12 engages under the first adjustment module 11 at least slightly at its front lower end. Visible through the contact area K. Both the first adjustment module 11 on the bearing plate 4 , as well as the adjustment modules 11 and 12 with each other are constrained with tools, such as dovetail fits or the like. It is understood that when using a plurality of bearing plates, a common adjusting device may be provided which causes an adjustment of all bearing plates. However, it is also conceivable to associate each bearing plate with a separate adjusting device.

The adjusting device 10 For example, it can be acted upon or actuated via the existing hydraulic system of a motor vehicle by means of oil pressure. As shown by the arrow P, the second adjustment module 12 a substantially horizontal (positively driven) exercise exercise, whereby the first adjustment module 11 a shift in the vertical direction takes place.

Such a position shift is in the 2 shown. As shown by the arrow P ', the first adjustment module has 11 due to a horizontal displacement of the second adjustment module 12 , moved vertically upwards. Visible by the now enlarged contact area K. By the vertical displacement of the first adjustment module 11 , became the bearing shield 4 or the second and third wave 2 . 3 , pivoting about the pivot point D, moves upwards. With this position change of the end shield 4 and the second shaft (crankshaft) 2 is over the connecting rod 6 also a displacement of the piston 7 and thus a change or influence on the compression ratio (see reduced distance between dashed line L and upper piston surface 9 ) realized. It is understood that after the adjustment, the position of the adjusting device, and thus all the elements associated with the adjustment, can be fixed.

3 shows a schematic representation, in plan view, the arrangement A of the first wave (main shaft) 1 , the second shaft (crankshaft) 2 as well as the third wave (intermediate wave) 3 , to each other. The waves 1 . 2 and 3 stand over the transmission means 1' . 2 ' and 3 ' in operative connection with each other. At its one axial end are the waves 1 . 2 and 3 in the bearing plate 4 stored. In addition, the waves are 1 . 2 and 3 over a second bearing plate 4 ' intercepted. A third (not shown) end shield can at the other axial end of the shafts 1 . 2 and 3 to be available.

The illustrated embodiment reveals only one possible solution and does not claim to be complete. Of course, there are other embodiments conceivable, as far as the functional principle of variable compression is maintained.

1

first Wave (main shaft)

1'

transmission means

2

second Shaft (crankshaft)

2 '

transmission means

3

third Shaft (intermediate shaft)

3 '

transmission means

4

end shield

4 '

end shield

5

bracket

6

connecting rod

7

piston

8th

Cylinder head unit

9

upper piston area

10

adjustment

11

first adjustment module

12

second adjustment module

A

arrangement

D

pivot point

K

contact area

L

line

P

arrow (horizontal adjustment direction)

P '

arrow (vertical adjustment direction)

Claims (10)

Internal combustion engine, in particular a series engine, for a motor vehicle, having at least one first shaft (main shaft) ( 1 ) and a second shaft (crankshaft) ( 2 ), where the waves ( 1 . 2 ) via at least two bearing plates ( 4 ) and the waves ( 1 . 2 ) over on the waves ( 1 . 2 ) transmission means ( 1' . 2 ' . 3 ' ), and wherein the second shaft (crankshaft) ( 2 ) via suitable means with at least one cylinder head unit ( 8th ), under definition of a compression ratio, is in operative connection, and wherein the position of the second shaft (crankshaft) ( 2 ) or the at least two bearing plates ( 4 ), in at least one degree of freedom, by means of an adjusting device ( 10 ) is variable, such that by means of the position change of the second shaft (crankshaft) ( 2 ) or the at least two bearing plates ( 4 ) the compression ratio of the internal combustion engine can be changed or influenced. Internal combustion engine, according to claim 1, characterized in that the adjusting device ( 10 ) directly or indirectly with the at least one end shield ( 4 . 4 ' ) is in operative connection, such that an adjustment of the adjusting device ( 10 ) an adjustment of the at least one end shield ( 4 . 4 ' ) causes. Internal combustion engine according to one of claims 1 or 2, characterized in that the adjusting device ( 10 ) is formed from at least two mutually displaceably mounted adjustment modules. Internal combustion engine according to claim 3, characterized in that the adjustment modules form a kind of ramp construction, wherein radially to the first shaft (main shaft) ( 1 ), a first adjustment module ( 11 ) at least slightly horizontally and the second adjustment module ( 12 ), due to the horizontal displacement of the first adjustment module ( 11 ), at least slightly vertically displaceable. Internal combustion engine according to one of claims 1 to 4, characterized in that the adjustment of the adjusting device ( 10 ) or the adjustment modules ( 10 . 11 ) and thus the at least one end shield ( 4 . 4 ' ) hydraulically, pneumatically or electromagnetically. Internal combustion engine according to one of claims 1 to 5, characterized in that the first shaft (main shaft) ( 1 ) is preferably designed as a straight shaft. Internal combustion engine according to one of claims 1 to 6, characterized in that a third shaft (intermediate shaft) ( 3 ), the third wave (intermediate wave) ( 3 ) between first wave ( 1 ) and second wave ( 2 ) and over on the third wave (intermediate wave) ( 3 ) transmission means ( 3 ' ), with the transmission means ( 1' . 2 ' ) of the first shaft (main shaft) ( 1 ) and the second shaft (crankshaft) ( 2 ) is engaged. Internal combustion engine according to one of claims 1 to 7, characterized in that it is in the transmission means ( 1' . 2 ' . 3 ' ) is about gears. Internal combustion engine according to one of claims 1 to 8, characterized in that the transmission means are chains, especially duplex chains. Internal combustion engine according to one of claims 1 to 9, characterized in that the at least two bearing plates ( 4 . 4 ' ) relative to the first shaft (main shaft) ( 1 ) and related to the second shaft (crankshaft) ( 2 ) or third wave (intermediate wave) ( 3 ) is adjustable, in particular vertically adjustable or pivotable, is formed, wherein the pivot point (D) of the at least two bearing plates ( 4 . 4 ' ) through the longitudinal axis of the first shaft (main shaft) ( 1 ) runs.