DE102009058090A1 - Reciprocating internal combustion engine i.e. 1-cylinder reciprocating internal combustion engine, has balancing shafts driven with same speed, where phase position of imbalance mass is determined from absolute position of shafts - Google Patents

Abstract

The engine has a crankshaft (2) with rotation axes, and two balancing shafts (3, 4), which are driven with same speed. The rotation axes of the crankshaft and rotation axes of the balancing shafts are aligned parallel together. A spatial position of the two balancing shafts is selected in a free manner. A phase position of a contra-rotating imbalance mass (3') is determined from a crank drive (1). A phase position of a co-rotating imbalance mass (4') is determined from mass of the former imbalance mass, the phase position of the former imbalance mass and an absolute position of the shafts.

Description

The invention relates to a reciprocating internal combustion engine with a compensation for free inertial forces and moments with the features of the preamble of claim 1.

Mass balance systems for reciprocating internal combustion engines generally consist of one or more (often two) balance shafts to compensate for free mass effects (free mass forces or free mass moments) of first or higher order.

If several (often two) balance shafts with the same direction of rotation are used to compensate for the free mass effects, the individual balance shafts are designed to be symmetrical with respect to their free mass effects, ie. H. the individual balance shafts generate identical mass force effects. They are usually positioned symmetrically to the crankshaft to generate no additional free moment about the crankshaft axis of rotation.

To compensate for circumferential mass forces and moments (for example, in 1-cylinder reciprocating internal combustion engines, in 2-cylinder in-line reciprocating internal combustion engines with 360 ° Kröpfungsversatz (ignition intervals 360 ° and 360 ° crank angle), in 2-cylinder inline reciprocating Internal combustion engines with 90 ° offset (ignition intervals 450 ° and 270 ° crank angle, etc.) often use two corotating shafts, both generating a rotating force of the same magnitude (same amount and phase relation with respect to the crankshaft) Balancer shafts take place in these engine designs to receive no undesirable mass torque with respect to the crankshaft axis.

For example, in the o. G. Reciprocating internal combustion engine designs, the two balance shafts often arranged symmetrically to the plane of the cylinder axes in order not to produce undesirable mass moment about the axis of rotation of the crankshaft. If, on the other hand, a specific mass momentum is to be generated, this takes place via a variation of the geometric arrangement of the balance shafts, such as height offset, lateral offset, etc.

This severely restricts the available, constructive solution options for mass balance and the internal combustion engine package. The achievable degree of mass balance can thus also be limited.

The present invention is therefore based on the object o. G. To avoid disadvantages.

This object is achieved by the feature in the characterizing part of patent claim 1.

The inventive design of the balance shaft system with a crankshaft in opposite directions and one with the crankshaft in the same direction rotating balance shaft allows greater freedom in terms of structural design and the engine package. According to the subclaims, the geometric arrangement of the balance shafts no longer has to be symmetrical with respect to the crankshaft rotational axis or the plane of the cylinder axes, but can be chosen freely (within certain limits given by design and functional boundary conditions).

For example, a counter to the direction of rotation of the crankshaft rotating balancing shaft to compensate for the resulting by the moving masses of the crank mechanism free forces in the direction of Brennkraftmaschinenquer- and engine high axis and moments around the engine cross and engine high axis are freely positioned within constructive and functional constraints. Another rotating with the direction of rotation of the crankshaft second balance shaft can then be freely positioned (in terms of their function of the compensation of the free moment about the axis of rotation of the crankshaft) to compensate for the resulting by the first balance shaft free moment about the axis of rotation of the crankshaft or to influence. The free mass effects of the second balancer shaft (the balancer shaft which rotates in the direction of rotation of the crankshaft) can be compensated completely or to an arbitrary degree via an adaptation of the mass distribution on the crankshaft.

A crank drive restriction can be implemented more easily in these reciprocating piston engine variants, since the geometric arrangement of the balance shafts - to compensate for the mass moment about the crankshaft axis - does not have to be symmetrical to the plane of the cylinder axes. A restriction of the crank mechanism means that the axis of the crankshaft does not intersect a cylinder axis.

The dependent claims form advantageous developments of the inventive design of the reciprocating internal combustion engine with a balance for free inertial forces and moments.

In the following the invention is explained in more detail with reference to two schematic representations in two figures.

1 schematically shows an inventive compensation for free inertial forces and moments, for example, for a 1-cylinder reciprocating internal combustion engine

2 symbolically shows the procedure in the interpretation of an inventive compensation for free inertial forces and moments.

1 schematically shows a mass balance for a crank mechanism 1 by way of example for a 1-cylinder internal combustion engine with a setting, wherein in the exemplary embodiment only oscillating masses of piston and connecting rod and their compensation are shown. The crank mechanism consists essentially of a crankshaft 2 a connecting rod 5 and a piston 6 , The compensation for free mass forces and moments of 1st order consists of a first, opposite to the crankshaft 2 rotating and a second, in the same direction with the crankshaft 2 rotating balance shaft 3 . 4 (AGW), each with a resulting imbalance mass 3 ' . 4 ' ,

According to the invention, the positions of the first balance shaft 3 and the second balance shaft 4 within the design limits freely selectable, with a phase angle of the opposing imbalance mass 3 ' from the crank mechanism 1 and a phase angle of the synchronous unbalanced mass 4 ' from a phase angle of the imbalance mass 3 ' and the absolute position of the first and the second balance shaft 3 . 4 with respect to the crank mechanism 1 is determined. Of course, the mass balance for free mass forces and moments 1st order also works for multi-cylinder inline reciprocating internal combustion engines. The mass action required on the crankshaft for balancing 2 can with the same effect on different cheeks of the crankshaft 2 be distributed.

Schränkung a:

Schränkungsmaß a.

d1:

Abstand Drehachse der ersten Ausgleichswelle 3 von der Drehachse des Kurbeltriebs 1.

d2:

Abstand Drehachse der zweiten Ausgleichswelle 4 von der Drehachse des Kurbeltriebs 1.

α1:

Laufwinkel der ersten Ausgleichswelle 3.

α2:

Laufwinkel der zweiten Ausgleichswelle 4.

α3:

Laufwinkel der Kurbelwelle 2

F_{AGWgegenläufig}:

Massenkraft der ersten Ausgleichswelle 3 aufgrund ihrer resultierenden Unwuchtmasse 3'.

F_{AGWgleichläufig}:

Massenkraft der zweiten Ausgleichswelle 4 aufgrund ihrer resultierenden Unwuchtmasse 4'.

F_OSZ:

Maximale oszillierende Massenkraft des Kurbeltriebs 1.

In 1 apply to the labels:

Setting a:

Setting dimension a.

d1:

Distance of rotation axis of the first balance shaft 3 from the axis of rotation of the crank mechanism 1 ,

d2:

Distance of rotation axis of the second balance shaft 4 from the axis of rotation of the crank mechanism 1 ,

α1:

Running angle of the first balance shaft 3 ,

α2:

Running angle of the second balance shaft 4 ,

α3:

Angle of the crankshaft 2

F _{AGW counter} :

Mass force of the first balance shaft 3 due to their resulting imbalance mass 3 ' ,

F _{AGWgleichgleich} :

Mass force of the second balance shaft 4 due to their resulting imbalance mass 4 ' ,

F _OSZ :

Maximum oscillating mass force of the crank mechanism 1 ,

The directions of rotation of the two balance shafts 3 . 4 and the crankshaft 2 and the running angles α1, α2, α3 of the two balance shafts 3 . 4 and the crankshaft 2 are symbolically represented by thin semi-circular arrows each about the axes of rotation.

The design of the balancer shaft 1 such that the total mass force effects in the direction of Brennkraftmaschinenquer- and the engine high axis and the mass moment effects around the engine cross and the engine high axis by the interaction of the inertial forces of the connecting rod 5 , Piston 6 , Crankshaft 2 and the first balance shaft 3 initially set to a desired level. This design is well known in mechanical engineering.

The design of the second balance shaft 4 occurs such that the mass moment about the axis of rotation of the crankshaft 2 is set to a desired level. For the unbalance force and the phase position of the resulting imbalance mass of the second balance shaft 4 set such that the following applies for the remaining moment: F _OSZ · a - F _{AGW Opposite} · sin (α1) · d1 + F _AGWsimilar · sin (α2) · d2 = desired value, with complete compensation z. B. zero

The through the second balance shaft 4 in the system (reciprocating internal combustion engine) introduced forces in the direction of Brennkraftmaschinenquer- and engine high axis or the resulting moments around the engine cross and engine high axis must be compensated in addition. In the engine longitudinal axis, the cylinders are arranged. Because the crankshaft 2 and the second balance shaft 4 have the same direction of rotation, an introduction of another balance shaft in the system is not necessary. This compensation can be done via a mass adjustment on the crankshaft 2 respectively.

Summary of the embodiment:

To compensate for an existing free mass moment or to generate a certain free mass moment around the crankshaft axis of rotation with the help of two balance shafts 3 . 4 with mutually different directions of rotation and with crankshaft speed, a balance shaft system described below is therefore proposed according to the invention:
The first balance shaft 3 (Direction of rotation opposite to the crankshaft rotation direction) can be freely positioned within the framework of constructive and functional constraints and serves primarily to compensate for the caused by the crank gear against the crankshaft rotation circumferential free mass moments around the engine cross and engine high axis and to compensate for opposing the crankshaft rotation rotating mass forces. The existing or through the first balance shaft 3 additionally resulting free mass moments around the axis of rotation of the crankshaft 2 be by the, from the perspective of the mass balance freely positionable second balancer shaft 4 (Direction of rotation equal to crankshaft rotation direction) (eg: balanced). Ie. the second balance shaft 4 Primarily used to compensate for the mass moment around the axis of rotation of the crankshaft 2 , The description of the primary balancing functions of the two balance shafts 3 . 4 are exemplary and are not intended to be limiting of the invention. Of course, if functionally possible, also the first balance shaft 3 to compensate for the mass moment about the axis of rotation of the crankshaft 2 contribute as well as the second balance shaft 4 to compensate for the free mass forces in the direction of Brennkraftmaschinenquer- and engine high axis and the free mass moments around the engine transverse and engine high axis can contribute. An essential feature is that to compensate for the second balance shaft 4 additionally introduced into the system forces no further balance shaft is necessary. This compensation function takes over the crankshaft 2 , whose masses can be adjusted to meet the desired mass balance accordingly.

The mass balance can be displayed for crank mechanisms with a pitch or for crank mechanisms without a pitch. Of course, the mass balance for free mass forces and moments 1st order also works for multi-cylinder inline reciprocating internal combustion engines.

In summary, the following advantages result from the embodiment according to the invention:
Introduction of crankshaft 2 in the same direction revolving second balance shaft 4 allows greater freedom with respect to the structural design and the engine package. The geometric arrangement of the first balance shaft 3 and the second balance shaft 4 no longer has to be symmetrical to the crankshaft axis or to the plane of the cylinder axes, but can (within certain limits) be chosen freely.

A crank drive restriction can be implemented more easily in these engine variants, since the geometric arrangement of the two balance shafts 3 . 4 - to compensate for a mass moment about the crankshaft axis - does not have to be symmetrical to the plane of the cylinder axes ( 1 ).

In the 1 1-cylinder reciprocating internal combustion engine crank mechanism without dislocation shown is only an exemplary embodiment and does not limit the application of the invention. Rather, it is possible, according to the invention to influence or compensate for the remaining moment 1st order to the crankshaft rotation axis also for crank mechanisms with desalination and or without restriction.

2 shows symbolically the procedure in the interpretation of an inventive compensation for free mass forces and moments in three steps, shown for four crank angle φ of the crankshaft 2 :
at 0 °, 90 °, 180 ° and 270 °.

Step 1 corresponds to the design of the counterbalancing balance shaft 3 , Considering the crank angle from top to bottom.

Step 2 corresponds to the interpretation of the corotating balance shaft 4 , Considering the crank angle from top to bottom.

Step 3 (dashed lines, with associated black arrows) corresponds to the adjustment of the unbalance of the crankshaft 2 due to the circumferential force created in step 2 due to the corotating balance shaft 4 , Considering the crank angle from top to bottom.

LIST OF REFERENCE NUMBERS

1

crankshaft

2

crankshaft

3

first balance shaft

3 '

Imbalance mass first balance shaft

4

second balance shaft

4 '

Unbalance mass second balance shaft

5

pleuel

6

piston

Claims (4)

Reciprocating internal combustion engine with compensation for free mass forces and moments, consisting of a crank mechanism ( 1 ) and a first, from the crank mechanism ( 1 ) in the opposite direction to a crankshaft ( 2 ) of the crank mechanism ( 1 ) with the same speed driven balancer shaft ( 3 ) and a second one from the crank drive ( 1 ) in the same direction as the crankshaft ( 2 ) of the crank mechanism ( 1 ) with the same speed driven balancer shaft ( 4 ) each having at least one imbalance mass ( 3 ' . 4 ' ), where axes of rotation of crankshaft ( 2 ), first and second balancing shafts ( 3 . 4 ) are aligned parallel to each other, characterized in that the spatial position (engine vertical axis and transverse axis) of the first and the second balancer shaft ( 3 . 4 ) is freely selectable, wherein a phase angle of the opposing imbalance mass ( 3 ' ) from the crank mechanism ( 1 ) is determined and a phase angle of the synchronous unbalanced mass ( 4 ' ) of a mass of imbalance mass ( 3 ' ) and their phase position and the absolute position of the first and the second balance shaft ( 3 . 4 ) is determined. Reciprocating internal combustion engine according to claim 1, characterized in that one about the axis of rotation of the crankshaft ( 2 ) of the crank mechanism ( 1 ) existing first order mass moment by the second balance shaft ( 4 ) compensable or can be influenced to any degree. Reciprocating internal combustion engine according to one of the claims 1 or 2, characterized in that a sum of the circulating mass force effect of the first and the second balance shaft ( 3 . 4 ) is the same or unequal size as the circulating free mass force of the crank mechanism ( 1 ). Reciprocating internal combustion engine according to one of the claims 1 to 3, characterized in that a sum of the circulating mass moment effect of the first and the second balance shaft ( 3 . 4 ) is the same or unequal size as the circulating free mass moment of the crank mechanism ( 1 ).

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