DE102011078648B4 - Internal combustion engine with crank mechanism - Google Patents

Abstract

Internal combustion engine with a crank mechanism, with at least one cylinder (1) and a reciprocating piston (2) therein, wherein the piston (2) via a first connecting rod (3) hinged first connecting rod (P1) with a about a pivot lever axis (6) pivotable pivot lever (5) at a first point (4) is pivotally connected, wherein a at a crankshaft (7) in a second pivot point (9) of a crank pin (10) hinged second connecting rod (P2) pivotally connected to the pivot lever ( 5) at a second engagement point (11) is connected, characterized in that the cylinder (1) with respect to the pivot lever (5) is arranged so that at the top dead center piston (2) has a first pivot point (3) with the , connecting first imaginary point (4) imaginary first line (L1) with the first (4) with the second point (11) connecting imaginary second line (L2) forms a first angle α between 0 and 90 °, and that the movements of the piston (2) and the crankshaft are offset by about 180 °, so that located at top dead center piston (2) is the crankshaft journal (10) of the crankshaft (7) in the motion train of the crank gear in a position away from the piston (2).

Description

The invention relates to an internal combustion engine with crank mechanism according to the preamble of claim 1.

Such an internal combustion engine is from the DE 10 2005 061 282 B4 known. In the known internal combustion engine, the piston side forces and the piston deceleration and acceleration at the top and bottom dead center are relatively large. This causes unwanted vibrations, limits the maximum speed of the internal combustion engine and reduces their durability.

The object of the present invention is to eliminate the disadvantages of the prior art. In particular, it is intended to specify an internal combustion engine which is as simple as possible to produce and which is improved with regard to the piston travel path, the torque curve, the piston speed, the piston acceleration and the piston side forces.

This object is solved by the features of claim 1. Advantageous embodiments of the invention will become apparent from the features of claims 2 to 8.

According to the invention it is proposed that the cylinder is arranged with respect to the pivot lever so that at the top dead center piston connecting the first point of articulation with the first point imaginary first line with the first connecting to the second point imaginary second line a first Angle α forms between 0 and 90 °.

For the purposes of the present invention, the terms "articulation point", "point of application", "pivoting lever pivot point" and "crankshaft pivot point" mean intersections which form the corresponding pivoting or rotating axes with a plane perpendicular thereto, for example the plane of the paper. The term "line" is understood to mean a straight line or a straight line.

With the proposed internal combustion engine, the following advantages are achieved compared to conventional internal combustion engines:
The piston accelerates faster from bottom dead center to top dead center. as a result, compression pressure and compression temperature increase, which in turn allows combustion with reduced ignition delay. The piston moves with a greatly delayed but uninterrupted movement through top dead center. This improves the degree of equalization and combustion efficiency. As a result, the energy recovered from combustion can be better converted into mechanical energy. It is possible to operate the internal combustion engine according to the invention at high speed. Vibrations and material loads remain relatively low.

In particular, piston side forces can be kept extremely low over almost all crankshaft rotation angles. This allows a reduction of wear and friction losses. Overall, the internal combustion engine according to the invention has improved durability and improved efficiency.

In terms of design, there is sufficient space available for the required bearings and for ensuring the lubricating oil supply of the bearings.

The advantages of the invention are achieved in particular by the fact that the movement of the piston and the crankshaft are offset by about 180 ° compared to the prior art. Ie. the piston is according to the invention at top dead center, when the corresponding crankshaft journal of the crankshaft is in the motion train of the crank gear in a position remote from the piston.

According to an advantageous embodiment forms at the top dead center piston, the second line with a connecting the second point with the second pivot point imaginary third line a second angle β of 90 to 270 °, preferably 150 ° to 205 °. Furthermore, it has proven expedient that a first distance a1 between the first articulation point and the first application point is greater than a second distance a2 between the second engagement point and the second articulation point. Ie. the first connecting rod is designed to be longer than the second connecting rod. For the relationship between the first a1 and the second distance a2, the following relationship expediently applies: a1> 2 · a2.

Conveniently, the first distance a1 is 3 to 4 times the second distance a2.

A third angle γ between the first line and a piston axis of the piston is at most ± 5 ° with a movement of the piston. Advantageously, the first point of application in the upper and / or lower pressure point is approximately on the piston axis. Ie. the first connecting rod according to the invention is reciprocated approximately along the piston axis. This can be minimized unwanted piston side forces.

According to a further advantageous embodiment of the invention it is provided that a crankshaft pivot, the second pivot point and the second point of attack in the top and / or bottom dead center are approximately on an imaginary straight line.

Finally, it is considered advantageous that the pivot lever axis to the crankshaft axis stationary, preferably movable, adjustable is formed.

With the invention, an internal combustion engine is provided, the speeds - especially as a small-volume diesel engine - can achieve that would not allow efficient combustion in conventional internal combustion engines with one-piece connecting rod more.

The crank mechanism according to the invention is suitable for all four-stroke engines with spark ignition and auto-ignition and all two-stroke engines with spark ignition and auto-ignition.

Advantageous embodiments of the invention will be explained below in connection with an embodiment with reference to the drawings. Show it:

1 a schematic side view of an internal combustion engine,

2 a sectional view through articulated connections according to 1 .

3 a further side view of the internal combustion engine according to 1 with the piston at bottom dead center,

4a -D the internal combustion engine according to 1 at different piston positions,

5 the Kolbenwegverlauf over the crankshaft rotation angle.

According to 1 and 2 the internal combustion engine according to the invention comprises a crank mechanism with at least one cylinder 1 and a reciprocating piston 2 on. A first connecting rod P1 is at a first point of articulation 3 in the piston 2 and at a second point of articulation 4 on a pivot lever 5 hinged. The swivel lever 5 is about a pivot axis 6 pivotable. It has a substantially triangular shape and is advantageously designed without forming a fork. With the reference number 7 is called a crankshaft which is rotatable about a crankshaft axis 8th is stored. A second connecting rod P2 is at a second point of articulation 9 on a crankshaft journal 10 hinged. The second connecting rod P2 is also at a second point of application 11 on the pivot lever 5 hinged. A first line between the first point of articulation 3 and the first point of attack 4 is denoted by the reference L1, a second line L2 connects the first point of application 4 with the second point of attack 11 , A third line L3 connects the second point of attack 11 with the second point of articulation 9 , The first L1 and the second line L2 include a first angle α, the second line L2 and the third line L3 include a second angle β.

According to another design feature, a fourth line L4, extending from the pivot lever axis, terminates 6 to the first point of attack 4 extends, and the first line L1 a fourth angle ε a. The fourth angle ε is less than 180 °, preferably less than 160 °; it is preferably in the range of 150 to 50 °.

As in particular from 2 can be seen, the second connecting rod P2, for example by means of a first sliding bearing 9a pivoted on the crankshaft journal 10 be held. The second connecting rod P2 is expediently bifurcated. With the reference number 12 a first bolt is designated, which the second connecting rod P2 and one on the pivot lever 5 provided second sliding bearing 11a be upheld.

The first connecting rod P1 is also forked. A second bolt 13 passes through the first connecting rod P1 and a third slide bearing 4a on the pivot lever 5 ,

As in particular from 1 can be seen, passes through a third bolt 14 the piston 2 as well as the first connecting rod P1. With the reference number 3a is a fourth sliding bearing, which is between the piston 2 and the third bolt 14 is formed. The reference number 6a finally designates a fifth slide bearing, with which the pivot lever 5 is pivotally mounted.

The fifth plain bearing 6a can be fixed by means of a mechanism not shown here in different positions. For this purpose, the pivot lever axis 6 for example, be adjustable along a rail or radially on an eccentric shaft. This allows parameters such as the torque curve, the piston travel, the compression, the piston side force and the like to change.

Of course, other bearings, for. B. needle roller bearings, ball bearings, bearings and the like., Can be used.

As in particular from 1 As can be seen, the first line L1 and the second line L2 close an acute first angle α, which is expediently 30 to 70 °, preferably 40 to 60 °. The second line L2 and the third line L3 include a second angle β. The second angle β is an obtuse or obtuse angle and is expediently 150 to 205 °, preferably 170 to 200 °. The proposed crank mechanism is characterized in its kinematics by the fact that at a stress of the second connecting rod P2 on pressure of the first connecting rod P1 claimed to train and thus the piston 2 is moved in the direction of bottom dead center.

3 illustrates further structural embodiments of the proposed internal combustion engine. The reference KM denotes a piston axis or piston center line. A distance a1 between the first articulation point 3 and the first point of attack 4 is three to four times larger than a second distance a2 between the second point of attack 11 and the second link point 9 , At the in 3 shown position of the piston 2 at the bottom dead center are also the crankshaft rotation axis 8th , the second pivot point 9 and the second point of attack 11 on an imaginary straight line. A third distance a3 between the crankshaft axis of rotation 8th and the second link point 9 is smaller than the second distance a2.

Conveniently, the second distance a2 is greater than 1 to 3 times the third distance a3.

An imaginary straight line G passes through the second articulation point 9 and the second point of attack 11 , The straight line G forms at the bottom dead center with the piston axis KM a fifth angle ρ. The fifth angle ρ corresponds to about a sixth angle σ, that of the fourth line L4 and one of the pivot lever axis 6 with the second point of attack 11 connecting fifth line L5 is included. The fifth angle ρ and the sixth angle σ differ by a maximum of 10 °. The fifth angle ρ and the sixth angle σ are in the range of 20 to 90 °, preferably 22 to 50 °.

The 4a to 4d show schematically the movement sequence from top dead center ( 4a ) each in 90 crankshaft rotation degree steps. In 4a is the piston 2 at top dead center. The first point of articulation 3 lies on the piston axis KM, the first point of attack 4 lies in this case approximately on the piston axis KM. The second point of articulation 9 and the second point of attack 11 and the crankshaft rotation axis 8th lie approximately on the line G.

At the in 4b shown second rotational position is the crankshaft 7 turned counterclockwise by 90 °. By means of the second connecting rod P2, the pivot lever 5 around the swivel lever axis 6 pivoted upwards. As a result, the first connecting rod P1 pulls the piston 2 back from top dead center.

4c shows the internal combustion engine in a third position. Here is the crankshaft 7 rotated 180 ° from the first position. The piston 2 is located at bottom dead center. The crankshaft axis 8th , the second pivot point 9 as well as the second point of attack 11 lie approximately on the line G. The first point of articulation 3 lies on the piston axis KM, the first point of attack 4 lies in this case approximately on the piston axis KM.

At the in 4d shown fourth position, the crankshaft is rotated by a further 90 ° counterclockwise. The second connecting rod P2 now applies to the pivoting lever 5 a tensile force, whereby this around the pivot lever axis 6 is pivoted down. As a result, the first connecting rod P1 pushes the piston 2 in the direction of top dead center. The first line L1 can only slightly swing back and forth by the third angle γ during a complete crankshaft revolution. As a result of the small third angle γ piston side forces are reduced to a minimum with the internal combustion engine according to the invention.

The third angle γ is during a whole crankshaft revolution at most ± 10 °, preferably ± 3 to ± 8 °, more preferably at most ± 1 ° to either side of the piston axis KM.

The achievable with the proposed internal combustion engine advantages are in particular from 5 seen. Therein, the piston travel over the crankshaft rotation angle of a conventional internal combustion engine (broken line) in comparison to the internal combustion engine according to the invention (solid line) is shown. How out 5 clearly visible, the piston accelerates 2 in the internal combustion engine according to the invention faster to top dead center. It moves with high retarded but uninterrupted motion through top dead center, then accelerates faster to bottom dead center. In comparison with a conventional internal combustion engine, the internal combustion engine according to the invention achieves a faster compression, a higher compression pressure, a higher compression temperature and thus better starting conditions for the combustion. The combustion is characterized in particular by low ignition delay. Overall, more energy can be converted in the region of top dead center. Furthermore, the internal combustion engine according to the invention is characterized in that piston delays before the dead centers and piston accelerations after the dead centers are lower than in conventional internal combustion engines with Gelenkpleuelkonstruktion. This allows operation of the internal combustion engine according to the invention at higher speeds. Because of the inventive design of the crankshaft gearbox, the internal combustion engine is characterized by extremely low piston side forces. This increases their durability and reduces vibrations.

LIST OF REFERENCE NUMBERS

1

cylinder

2

piston

3

first point of articulation

3a

fourth sliding bearing

4

first point of attack

4a

third plain bearing

5

pivoting lever

6

Pivoting lever axis

6a

fifth plain bearing

7

crankshaft

8th

Crankshaft rotation axis or crankshaft rotation point

9

second articulation point

9a

first sliding bearing

10

crankshaft journal

11

second point of attack

11a

second sliding bearing

12

first bolt

13

second bolt

14

third bolt

a1

first distance

a2

second distance

a3

third distance

G

Just

KM

piston axis

L1

first line

L2

second line

L3

third line

L4

fourth line

L5

fifth line

P1

first connecting rod

P2

second connecting rod

α

first angle

β

second angle

γ

third angle

ε

fourth angle

ρ

fifth angle

σ

sixth angle

Claims (8)

Internal combustion engine with crank mechanism, with at least one cylinder ( 1 ) and a piston reciprocable therein ( 2 ), the piston ( 2 ) about it in a first point of articulation ( 3 ) hinged first connecting rod (P1) with one about a pivot lever axis ( 6 ) pivoting swivel lever ( 5 ) at a first point of attack ( 4 ) is pivotally connected, one on a crankshaft ( 7 ) in a second articulation point ( 9 ) of a crankshaft journal ( 10 ) hinged second connecting rod (P2) pivotally connected to the pivot lever (P2) 5 ) at a second point of attack ( 11 ), characterized in that the cylinder ( 1 ) with respect to the pivoting lever ( 5 ) is arranged so that when located at top dead center piston ( 2 ) one the first pivot point ( 3 ) with the. first point of attack ( 4 connecting imaginary first line (L1) with a first ( 4 ) with the second point of attack ( 11 ) connecting imaginary second line (L2) forms a first angle α between 0 and 90 °, and that the movements of the piston ( 2 ) and the crankshaft are offset by about 180 °, so that located at top dead center piston ( 2 ) the crankshaft journal ( 10 ) of the crankshaft ( 7 ) in the motion train of the crank mechanism in one of the piston ( 2 ) most distant position. Internal combustion engine according to claim 1, wherein at piston located at top dead center ( 2 ) the second line (L2) with a second point of attack ( 11 ) with the second point of articulation ( 9 ) connecting the imaginary third line (L3) forms a second angle β of 90 to 270 °, preferably 150 to 205 °. Internal combustion engine according to one of the preceding claims, wherein a first distance a1 between the first pivot point ( 3 ) and the first point of attack ( 4 ) is greater than a second distance a2 between the second point ( 11 ) and the second pivot point ( 9 ). Internal combustion engine according to one of the preceding claims, wherein the relationship between the first a1 and the second distance a2 is as follows: a1> 2 *, a2. Internal combustion engine according to one of the preceding claims, wherein a third angle γ between the first line (L1) and a piston axis (KM) of the piston ( 2 ) during a movement of the piston ( 2 ) is at most ± 5 °. Internal combustion engine according to one of the preceding claims, wherein the first point of application ( 4 ) in the upper and / or lower dead center is approximately on the piston axis (KM). Internal combustion engine according to one of the preceding claims, wherein a crankshaft rotation point ( 8th ), the second pivot point ( 9 ) and the second point of attack ( 11 ) lie in the upper and / or lower dead center approximately on an imaginary line (G). Internal combustion engine according to one of the preceding claims, wherein the pivot lever axis ( 6 ) to the crankshaft axis ( 8th ) stationary, preferably adjustable in position, is formed.

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