DE102014215851A1 - Reciprocating internal combustion engine - Google Patents

Abstract

Reciprocating internal combustion engine having at least a first and a second cylinder, wherein in the first cylinder, a first piston via a first crank mechanism with a first connecting rod and a first crankshaft and in the second cylinder, a second piston via a second crank mechanism with a second connecting rod and a second crankshaft is driven to lift, the first and the second crankshaft in a first and a second engine housing of the reciprocating internal combustion engine are arranged parallel to each other and are driven in opposite directions, wherein the first and the second crankshaft are not in operative connection with each other and that for a Synchronization of the crank mechanisms for the first crank mechanism, a first electric machine and for the second crank mechanism, a second electric machine is provided.
Due to the configuration of the invention, a NVH (Noise, Vibration, Harshness, German: noise, vibration, roughness) optimal Range Extender can be displayed in a simple manner.

Description

The invention relates to a reciprocating internal combustion engine having the features of the preamble of patent claim 1.

A generic reciprocating internal combustion engine, from which the present invention proceeds, for example, from the international patent application with the publication number WO 2012/056275 A1 known. From the WO 2012/056275 A1 is a two-cylinder reciprocating internal combustion engine is known, which can be used as a so-called. Range Extender (REX, German: range extender for electric vehicles). In this known reciprocating internal combustion engine, a partial compensation of the dynamic moments is achieved via the arrangement of the crankshaft and the generator. The range extender has two separate crankshafts, which are arranged parallel to the axis and connected by gears. The generator is driven by a 2: 1 ratio in opposite directions to a cylinder. As a result, the start and Abstellmoment the reciprocating internal combustion engine and the inertial forces of the first order are partially compensated.

A disadvantage of this known arrangement is that the mass forces are not completely balanced, especially the second order. In addition, the compound of the known range extender of the two counter-rotating crankshafts with two gears for friction and acoustic reasons is unfavorable. Next, the generator runs counter to only one crankshaft, whereby the start and Abstellmoment can not be fully compensated.

In this embodiment, it is disadvantageous that no complete mass balance is performed and thus unwanted residual vibrations remain.

Another generic reciprocating internal combustion engine is for example from the German patent application DE 10 2010 025 002 A1 known. In this publication, an energy conversion system is described which comprises an internal combustion engine and a generator driven by the internal combustion engine. Furthermore, the energy conversion system has a rotational connection, which couples a first shaft of the internal combustion engine with at least one second shaft of the energy conversion system, wherein the second shaft rotates in opposite directions to the first shaft and the first shaft is arranged parallel to the second shaft. Here are the products of moments of inertia and respective associated speed ratios of each other rotatably coupled by means of the rotational connection, rotating components at least approximately cancel each other.

Also in this embodiment, it is disadvantageous that a complete mass balance is virtually impossible.

Further generic reciprocating internal combustion engines with two cylinders are also known for example from the US patent application US 2002/0023599 A1 , the Japanese Patent Application JP 63-97829 and Japanese Patent Publication JP 60-45727 known.

The object of the present invention is to avoid the disadvantages of the generic reciprocating internal combustion engines mentioned above.

This object is solved by the features in the characterizing part of patent claim 1.

In summary, it can be said that a reciprocating internal combustion engine having at least two cylinders, it may also be four or six or even more cylinders is proposed, with two paraxial crankshafts, which, as known from the prior art, rotate in opposite directions. In contrast to the prior art, however, the crankshafts are not in operative connection with each other, but each crankshaft is a separate electric machine, such. B. a generator driven in opposite directions. To achieve mass balancing of second order, a ratio of 2: 1 is selected between crankshaft and electric machine or generator.

Due to the separate arrangement, each cylinder (in the case of a two-cylinder reciprocating internal combustion engine) can be operated independently of the other. This makes a so-called "split engine" feasible, d. H. a cylinder can be turned off. The common mode of the two cylinders is ensured by the control of the electric machine. In principle, each crankshaft position or ignition sequence can be set in an advantageous manner. Optionally, in single-cylinder operation, an independent first-order balance shaft can be electrically operated or mechanically switched on and off via an engagement clutch. Also, this balancing shaft must be exactly controlled in terms of position and speed driven.

Thus, with this two-cylinder reciprocating internal combustion engine according to the invention a perfect balance of first order and second order possible. In addition, the starting and Abstellmomente be compensated in an ideal way. Due to the independent operation of the two cylinders, a split operation of the cylinders is possible, ie, a cylinder can be turned off. This significantly reduces fuel consumption at low loads.

Advantageous developments of the invention are described in the subclaims.

With the embodiment according to claim 2, depending on the translation, a mass balance on the electric machines first or second order possible.

The drive options according to claims 3 to 5 are three particularly preferred embodiments for a phase-correct drive.

By the drive options according to claims 6 and 7 both a fired and a towed operation of the reciprocating internal combustion engine is possible, whereby this is perfectly suitable for a range extender operation.

With the embodiment according to claim 8, a mass balance of the first order can be displayed.

With the embodiment according to claim 9, a mass balance second order can be displayed.

With the embodiment according to claim 10, a single-cylinder operation of the reciprocating internal combustion engine is possible with perfectly balanced masses.

With the embodiment according to claim 11 can still last remaining forces or moments, z. B. when connecting or disconnecting a cylinder, are completely attenuated between the two cylinders.

The invention is explained in more detail below with reference to four exemplary embodiments in five figures.

1 schematically shows a first embodiment of a reciprocating internal combustion engine according to the invention.

2 schematically shows a second embodiment of the reciprocating internal combustion engine according to the invention.

3 schematically shows a third embodiment of the reciprocating internal combustion engine according to the invention.

4 schematically shows a fourth embodiment of the reciprocating internal combustion engine according to the invention.

5 shows in tabular form for each of the four embodiments, the possibility of connecting a generator, the respective translation for the generator, a respective possibility of angular momentum compensation and a possibility of mass balancing first and second order.

• – Kurbelwelle 4 oder 4',
• – Pleuel 5 oder 5',
• – Kolben 3 oder 3'.

1 schematically shows a first embodiment of a reciprocating internal combustion engine according to the invention 1 with a first and a second cylinder 2 . 2 ' , In the first cylinder 2 is a first piston 3 via a first crank mechanism 4 with a first connecting rod 5 and a first crankshaft 6 Hubbeweglich drivable. In the second cylinder 2 ' is a second piston 3 ' over a second crank 14 ' with a second connecting rod 5 ' and a second crankshaft 6 Hubbeweglich drivable. A single crank mechanism thus consists of the components

• - Crankshaft 4 or 4 ' .
• - connecting rod 5 or 5 ' .
• - Piston 3 or 3 ' ,

The first crankshaft 6 is in a first machine housing 7 and the second crankshaft 6 ' is in a second machine housing 7 ' in the reciprocating internal combustion engine 1 arranged, wherein the first crankshaft 6 and the second crankshaft 6 ' can be driven parallel to each other and in opposite directions. One direction of rotation of the crank mechanisms 4 . 4 ' is shown schematically by a round arrow.

According to the invention, the first and the second crankshaft 6 . 6 ' not coupled to each other, ie they are not in operative connection with each other and for a synchronization of the crank mechanisms 4 . 4 ' is for the first crank mechanism 4 a first electric machine 8th and for the second crank mechanism 4 ' a second electric machine 8th' intended.

Next have the electric machines 8th . 8th' via an imbalance mass, which is schematically represented by a black circle segment. At the electric machine 8th . 8th' For example, it may be a generator that either drives the crank 4 . 4 ' drives or from the crank mechanism 4 . 4 ' is driven and thereby generates electrical energy. Due to the unnumbered imbalances on the electrical machines 8th . 8th' can the electrical machines 8th . 8th' be provided for a mass balance. In this first embodiment, the electrical machines 8th . 8th' each via gears 9 . 10 with the corresponding crankshaft 6 . 6 ' in active connection. The speed of electric machines 8th . 8th' can be identical to the speed of the corresponding crankshaft 6 . 6 ' be. In this case is a Mass balancing first order possible. In another embodiment, the speed of the electric machines 8th . 8th' twice as large as the speed of the corresponding crankshaft 6 . 6 ' , As a result, a balancing second order can be realized.

Furthermore, in the first embodiment for the second crank mechanism 4 ' a switchable balance shaft 12 intended. This can for example be mechanically switched on and off via a clutch or electrically engaged and disengaged.

Next, in a first embodiment, the first machine housing 7 against the second machine housing 7 ' in the reciprocating internal combustion engine 1 supported by a passive bearing. By doing so, remaining vibrations can be effectively eliminated. In another embodiment, instead of the passive bearing 13 also an active camp 13 be provided.

In the 2 to 4 are only from 1 deviating components quantified to preserve a better overview.

2 schematically shows a second embodiment of the reciprocating internal combustion engine according to the invention 1 , The basic structure of the reciprocating internal combustion engine according to the invention 1 is similar to that 1 but they are the generators 8th . 8th' on the crankshaft axes of the crankshafts 6 . 6 ' arranged. The generators 8th . 8th' and the corresponding crankshafts 6 . 6 ' thus have the same axis of rotation, wherein an unnumbered rotor of the electric machines 8th . 8th' each to the corresponding crankshaft 6 . 6 ' is coupled.

In addition, for every crank mechanism 4 . 4 ' an endless traction mechanism 11 , For example, a toothed belt or a chain, provided for driving each not quantified balance shaft. Preferably, the balance shafts are driven at twice the crankshaft speed, for a second-order mass balance. The electrical machines 8th . 8th' thus do not serve in the second embodiment for a mass balance.

3 schematically shows a third embodiment of the reciprocating internal combustion engine according to the invention 1 , 3 again shows the reciprocating internal combustion engine according to the invention 1 out 2 but without separate mass balance shafts. An angular momentum compensation can be done via the electrical machines 8th . 8th' respectively.

4 schematically shows a fourth embodiment of the reciprocating internal combustion engine according to the invention 1 , 4 again shows a similar embodiment as the 1 to 3 however, in these embodiments, the generators are 8th . 8th' each via a traction mechanism 11 , such as a tooth rib or a chain of the crank mechanism 4 . 4 ' driven. Also in this embodiment, the generators 8th . 8th' preferably driven at twice the crankshaft speed, for second order mass balancing.

5 shows in tabular form for each of the four embodiments (column 1 , from top to bottom embodiment 1 to 4) the possibility of connecting a generator 8th . 8th' (Column 2 ), the respective translation for the generator 8th . 8th' (Column 3 ), the respective possibility of angular momentum compensation (Column 4 ) and the possibility of mass balancing first (Column 5 ) and second order (column 6 ).

It is thus inventively a reciprocating internal combustion engine 1 with at least two cylinders 2 . 2 ' It may also be four or six or even more cylinders, proposed with two paraxial crankshafts 6 . 6 ' that turn in opposite directions. In contrast to the prior art, the crankshafts 6 . 6 ' but not in operative connection, for example via gears, but of each crankshaft 6 . 6 ' becomes its own electric machine 8th . 8th' ^, such as B. a generator also driven in opposite directions. In order to achieve a mass balance of second order, is between crankshaft 6 . 6 ' and electric machine 8th . 8th' or generator selected a translation of 2: 1.

Due to the separate arrangement, each cylinder 2 . 2 ' (In the case of a two-cylinder reciprocating internal combustion engine) are operated independently of the other. As a result, a so-called "split engine" can be implemented, ie a cylinder 2 . 2 ' can be turned off. The common mode of the two cylinders 2 . 2 ' is via the control of the electric machine 8th . 8th' ensured. In principle, each crankshaft position or ignition sequence can be set in an advantageous manner. Optionally, in single-cylinder operation, an independent first-order balance shaft can be electrically operated or mechanically switched on and off via an engagement clutch. Also, this balancing shaft must be exactly controlled in terms of position and speed driven.

Thus, with this two-cylinder reciprocating internal combustion engine according to the invention a perfect balance of first order and second order possible. In addition, the starting and Abstellmomente be compensated in an ideal way. Due to the independent operation of the two cylinders 2 . 2 ' is a split operation of the cylinders 2 . 2 ' possible, ie, a cylinder can be turned off become. This significantly reduces fuel consumption at low loads.

LIST OF REFERENCE NUMBERS

1

Reciprocating internal combustion engine

2

first cylinder

2 '

second cylinder

3

first piston

3 '

second piston

4

first crank mechanism

4 '

second crank mechanism

5

first connecting rod

5 '

second connecting rod

6

first crankshaft

6 '

second crankshaft

7

first machine housing

7 '

second machine housing

8th

first electric machine

8th'

second electric machine

9

gear

10

gear

11

Endloszugmittelgetriebe

12

balancer shaft

13

camp

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012/056275 A1 [0002, 0002]
• DE 102010025002 A1 [0005]
• US 2002/0023599 A1 [0007]
• JP 63-97829 [0007]
• JP 60-45727 [0007]

Claims (11)

Reciprocating internal combustion engine ( 1 ) with at least a first ( 2 ) and a second cylinder ( 2 ' ), wherein in the first cylinder ( 2 ) a first piston ( 3 ) via a first crank mechanism ( 4 ) with a first connecting rod ( 5 ) and a first crankshaft ( 6 ) and in the second cylinder ( 2 ' ) a second piston ( 3 ' ) via a second crank mechanism ( 4 ' ) with a second connecting rod ( 5 ' ) and a second crankshaft ( 6 ' ) is reciprocally driven, wherein the first and the second crankshaft ( 6 . 6 ' ) in a first ( 7 ) and a second machine housing ( 7 ' ) of the reciprocating internal combustion engine ( 1 ) are arranged parallel to each other and are driven in opposite directions, characterized in that the first and the second crankshaft ( 6 . 6 ' ) are not in operative connection with each other and that for a synchronization of the crank mechanisms ( 4 . 4 ' ) for the first crank mechanism ( 4 ) a first electric machine ( 8th ) and for the second crank mechanism ( 4 ' ) a second electric machine ( 8th' ) is provided. Reciprocating internal combustion engine according to claim 1, characterized in that the electrical machines ( 8th . 8th' ) are provided for a mass balance. Reciprocating internal combustion engine according to claim 1 or 2, characterized in that the electrical machines ( 8th . 8th' ) each have two gears ( 9 . 10 ) with the corresponding crankshaft ( 6 . 6 ' ) are in operative connection. Reciprocating internal combustion engine according to claim 1 or 2, characterized in that the electrical machines ( 8th . 8th' ) each via a endless traction mechanism ( 11 . 11 ' ) with the corresponding crankshaft ( 6 . 6 ' ) are in operative connection. Reciprocating internal combustion engine according to claim 1 or 2, characterized in that an electrical machine ( 8th . 8th' ) and the corresponding crankshaft ( 6 . 6 ' ) have the same axis of rotation and a rotor of the electric machine ( 8th . 8th' ) to the corresponding crankshaft ( 6 . 6 ' ) is coupled. Reciprocating internal combustion engine according to one of the claims 1 to 5, characterized in that a crankshaft ( 6 . 6 ' ) of a corresponding electrical machine ( 8th . 8th' ) is drivable. Reciprocating internal combustion engine according to one of the claims 1 to 5 , characterized in that an electric machine ( 8th . 8th' ) of a corresponding crankshaft ( 6 . 6 ' ) is drivable. Reciprocating internal combustion engine according to one of the claims 1 to 7, characterized in that a rotational speed of the electric machine ( 8th . 8th' ) is equal to a speed of the corresponding crankshaft ( 6 . 6 ' ). Reciprocating internal combustion engine according to one of the claims 1 to 7, characterized in that a rotational speed of the electric machine ( 8th . 8th' ) is twice as large as a speed of the corresponding crankshaft ( 6 . 6 ' ). Reciprocating internal combustion engine according to one of the claims 1 to 9, characterized in that for a crank drive ( 4 . 4 ' ) a switchable balance shaft ( 12 ) is provided. Reciprocating internal combustion engine according to one of the claims 1 to 10, characterized in that the first machine housing ( 7 ) against the second machine housing ( 7 ' ) in the reciprocating internal combustion engine ( 1 ) via a passive or an active camp ( 13 ) is supported.

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