DE202015106332U1 - Electromagnetic ignition system for an internal combustion engine, as well as combustion engine with ignition system - Google Patents

Abstract

An ignition system for an internal combustion engine having at least one cylinder (10), a reciprocating piston (20) which can be moved back and forth in the cylinder (10) and has a piston head (21) and a combustion chamber (33) adjacent to the piston head (21) Ignition system is designed as an electromagnetic ignition system for ignition of a fuel-air mixture in the combustion chamber (33), characterized by a primary winding (40) in the cylinder (10) and at least one secondary winding (50) in the cylinder (10) and / or in the reciprocating piston (20), wherein the at least one secondary winding (50) is connected to at least two ignition electrodes (51, 52) with which a spark can be generated in the combustion chamber (33).

Description

The invention relates to an ignition system according to the preamble of claim 1 for an internal combustion engine having at least one cylinder, a reciprocating in the cylinder reciprocating piston and a combustion chamber, wherein the ignition system as an electromagnetic ignition system for igniting a fuel-air mixture in the combustion chamber is trained.

Such an ignition system typically includes a spark plug protruding into the cylinder to create a spark in the combustion chamber there. For example, the US 2005/0061294 A1 an engine with such spark plugs. Also the US 7,559,319 B2 describes an ignition system with spark plugs.

In internal combustion engines, however, there is often the need to size them smaller in order to accommodate them as smaller supplementary drives in hybrid vehicles, for example. In particular, the required installation space above the cylinder head can be problematic if both multiple injectors and a plurality of spark plugs must be arranged in a direct injection. In this case, for example, a reduction in dimensions of these components or another arrangement does not offer sufficient potential to substantially reduce the installation space. One approach may therefore be to fundamentally change the mode of operation of the internal combustion engine, wherein the prior art may provide suggestions for alternative modes of operation of internal combustion engines.

For example, this describes US 7,793,634 B2 the ability to move the reciprocating piston of an internal combustion engine not only by the combustion of a fuel-air mixture in the combustion chamber, but to drive the reciprocating electromagnetically. This electromagnetic operation can be used alone or in combination with the combustion operation. For this purpose, there is a reciprocating piston of a magnetic material and the cylinders have coils through which the reciprocating move through. By appropriate current flow in the coils, the reciprocating piston can be moved back and forth. This can reduce fuel consumption, but this does not lead to a reduction in the installation space of the engine.

Also from the US 8,991,356 B2 is an electromagnetic support of an internal combustion engine is known in which, for example, reciprocating piston with permanent magnets and cylinders are provided with electromagnets. By appropriate power supply to the electromagnets, an alternating magnetic field can be generated, with which between the permanent magnet of the reciprocating piston and the electromagnet alternately an attraction and a repulsion can be generated. This attraction and repulsion supports the reciprocating motion of the reciprocating pistons. From the US 2011/0221208 A1 a similar arrangement is known in which, conversely, the kinetic energy of the reciprocating piston is converted in their reciprocation into electrical energy.

With all these systems, however, the required space for an internal combustion engine can not be reduced. On the other hand, for example, the US 6,883,507 B2 an internal combustion engine without spark plugs, in which a fuel-air mixture in the combustion chamber is ignited by a corona discharge. In this case, the fuel-air mixture is ionized for ignition.

The invention has for its object to provide an alternative ignition system with which in particular the space above a cylinder-reciprocating unit can be reduced.

According to the invention the object is achieved by an ignition system with the features of claim 1 and an associated internal combustion engine according to claim 8.

It should be noted that the features listed in the following description as well as measures in any technically meaningful way can be combined with each other and show other embodiments of the invention. The description additionally characterizes and specifies the invention, in particular in connection with the figures.

The ignition system according to the invention is suitable for use in an internal combustion engine having at least one cylinder, a reciprocating piston which can be moved back and forth in the cylinder and has a piston head and a combustion chamber adjacent to the piston head. In this case, the ignition system is designed as an electromagnetic ignition system for igniting a fuel-air mixture in the combustion chamber and has a primary winding in the cylinder and at least one secondary winding also in the cylinder or in the reciprocating piston. The secondary winding is connected to at least two ignition electrodes. Between these ignition electrodes, a spark can be generated with which a fuel-air mixture can be ignited in the combustion chamber.

The ignition of the fuel-air mixture is thus not carried out by a conventional spark plug, which protrudes with ignition electrodes in the combustion chamber. Rather, the ignition system is integrated into a cylinder-reciprocating unit, which no spark plug more is required. This leads to a saving of components and reduces in particular the space in the head area of an engine. There is no more space for the introduction of a spark plug required, so that the engine can be made smaller overall. This is particularly advantageous when the internal combustion engine is a supplementary engine to an electric drive in a motor vehicle with hybrid drive. The term of the spark plug is intended to include both a spark plug of a gasoline engine and a glow plug of a diesel engine synonymously, and by no means limitative. In this respect, spark plugs / glow plugs can be dispensed with with the invention.

If no spark plug has to be integrated, this also leads to a higher degree of design freedom in the design and arrangement of other components in the head region of the internal combustion engine. For example, intake and exhaust valves can be made larger and / or arranged more advantageously. Also in the choice of position for a spark ignition system of the invention provides a higher design freedom. For example, sparks can be generated by appropriately positioned ignition electrodes at different positions. The position of the elements for generating the spark can be better adapted to the requirements of the engine.

Different positions for the generation of a spark can be realized in particular by a corresponding arrangement of the secondary winding. For example, the secondary winding may be provided in the cylinder like the primary winding, wherein the secondary winding is connected to at least two ignition electrodes in the region of the cylinder inner wall. Both windings are then located as outer and inner winding in the cylinder jacket. This embodiment has the advantage that the position of the spark on the cylinder inner wall can be selected relatively freely, so that an optimum combustion process can be triggered in the combustion chamber.

In an alternative embodiment of the invention, the at least one secondary winding is arranged in the reciprocating piston, wherein the secondary winding is connected to at least two ignition electrodes in the region of the piston crown. In this embodiment, sparks can be generated on the piston crown, which adjoins the combustion chamber. In a preferred embodiment of this variant, the primary winding is formed spirally in the cylinder jacket of the cylinder, while the at least one secondary winding is formed spirally in the piston skirt or piston skirt of the reciprocating piston, wherein the primary winding and the secondary winding extend coaxially.

The operation of the electromagnetic ignition system is based essentially on the principle of an ignition coil. The secondary winding is within the primary winding in the cylinder, wherein the reciprocating piston serves as a common core, which is magnetizable. The reciprocating piston is therefore expediently at least in the region of the secondary winding of a magnetizable metal. Furthermore, the low-resistance primary winding preferably has fewer turns than the high-resistance secondary winding.

In the primary winding, a current is generated, which in turn generates a magnetic field. This magnetic field also contains the secondary winding. If the current flow in the primary winding is interrupted, the magnetic field collapses, whereby a high-voltage pulse is generated in the secondary winding by induction, with which a spark can be generated at the ignition electrodes. This process can be repeated at short intervals, so that during operation of the internal combustion engine at a selected time z. B. can generate a spark shortly before the top dead center of the reciprocating piston in the combustion chamber.

In the electromagnetic ignition system according to the invention, the primary winding is thus defined by the fact that current flows through it and a magnetic field is generated. The secondary winding is defined by inducing a high voltage pulse in it when this magnetic field collapses. In order to control the current flow in the primary winding for this purpose, the primary winding is preferably in connection with a control device which is designed accordingly for such a control. In particular, the control unit is designed to control the current flow in the primary winding such that a spark is generated at the ignition electrodes of the at least one secondary winding at a predetermined time. This timing for generating the spark is preferably defined as a function of the position of the reciprocating piston within the cylinder.

As with previous ignition systems, the spark must be generated at a specific time, which depends on the position of the piston inside the cylinder. If the secondary winding is arranged in the reciprocating piston, the movement of the secondary winding together with the reciprocating piston has to be considered, so that in this embodiment the secondary winding must be arranged on the reciprocating piston in such a way that it is in a position relative to the primary winding at the relevant time. in which the required high-voltage pulse in the secondary winding can be generated when the current flow in the primary winding is interrupted.

Also included in the invention is an internal combustion engine having at least one cylinder, a reciprocating piston reciprocable in the cylinder and having a piston head and a combustion chamber adjacent to the piston head. The internal combustion engine has an electromagnetic ignition system for igniting the fuel-air mixture in the combustion chamber, which is formed according to one or more of the described embodiments. In this case, the internal combustion engine usually has a plurality of cylinders with an associated reciprocating piston and a respective electromagnetic ignition system, wherein the current flow in the primary windings of the respective ignition system is controllable via a central control unit. The central control unit thus controls all ignition systems and synchronizes them.

Further advantageous embodiments of the invention are disclosed in the subclaims and the following description of the figures. It shows the only one

1 a schematic representation of a cylinder-reciprocating-piston unit of an internal combustion engine with an embodiment of an ignition system according to the invention.

However, the illustration is to be understood only as an example and the ignition system according to the invention can also be used for other engine types.

In 1 schematically a cylinder-reciprocating unit of an internal combustion engine is shown, wherein the unit is a cylinder 10 in which a reciprocating piston 20 is reciprocable. The reciprocating piston 20 is connected in a known manner via a connecting rod with a crankshaft whose rotation is represented by a rotation arrow. Above a piston crown 21 of the reciprocating piston 20 a combustion chamber forms 33 in the air and fuel are introduced to be burned there. The supply and mixing of air and fuel can be carried out in a known manner, in particular with a valve control. This controls valves and thus also the charge exchange by opening and closing air inlet and exhaust gas outlet channels of the internal combustion engine.

In the embodiment of the 1 is in the upper part of the cylinder 10 an inlet valve 31 for supplying air into the combustion chamber 33 intended. The internal combustion engine is exemplified with a direct injection, allowing fuel to the combustion chamber 33 directly via an injection nozzle shown only schematically 30 is supplied. After combustion, exhaust gas is exhausted through the exhaust valve 32 from the combustion chamber 33 led out. The valves 31 . 32 are moved over camshafts whose rotation in 1 also shown with rotation arrows, while the upward movement of the reciprocating piston 20 is shown with a corresponding arrow upwards.

For igniting the fuel-air mixture, an ignition system is provided. That in the embodiment of the 1 used ignition system has an outer primary winding 40 up in the cylinder 10 is arranged. For example, she is in the cylinder jacket 11 integrated. The primary winding 40 has several windings that spiral in the cylinder jacket 11 are arranged so that the primary winding 40 coaxial with the reciprocating piston 20 extends. The terminal ends of the primary winding 40 are out of the cylinder 10 led out and with a control unit 60 connected. At the control unit 60 it is in particular an engine control unit (ECU - Electronic Control Unit).

A secondary winding can be inside the primary winding 40 in the cylinder jacket 11 be arranged.

In the embodiment of the 1 is the secondary winding 50 but in the reciprocating piston 20 , In particular, it is in the piston skirt 22 or piston skirt 22 integrated, located below the piston crown 21 located. The secondary winding 50 moves during operation of the internal combustion engine thus with the reciprocating piston 20 back and forth.

The secondary winding 50 is with two ignition electrodes 51 and 52 connected to the piston crown 21 are formed. This connection is in 1 represented by dashed lines, but this is only an exemplary connection show. The course of the connection can be suitably chosen. Further, the secondary winding 50 in 1 shown with fewer windings than the primary winding 40 This is preferably reversed, with the secondary winding 50 has more windings than the primary winding 40 , The illustration thus serves only to clarify the basic principle of the invention.

For example, there are the ignition electrodes 51 . 52 in the edge region of the piston crown 21 as it is in the embodiment of the 1 the case is. The ignition electrodes 51 . 52 however, can also be found elsewhere on the piston crown 21 to be ordered. Furthermore, more than two ignition electrodes can be provided.

The internal combustion engine has a plurality of these cylinder-reciprocating units, wherein the control unit 60 in connection with the respective ignition system of each unit. So can through the control unit 60 Synchronized sparks are generated in all cylinders.

Moves the piston 20 , as in 1 indicated by an arrow, towards its top dead center, the control unit interrupts 60 the current flow in the primary winding 40 such that the previously generated magnetic field collapses. This occurs at a time chosen to be offset by the high voltage pulse in the secondary winding 50 generated sparks on the ignition electrodes 51 . 52 the right moment is generated to the compressed fuel-air mixture in the combustion chamber 33 to ignite. The primary winding 40 and the secondary winding 50 are therefore arranged so that the secondary winding 50 just before the top dead center of the reciprocating piston 20 correspondingly within the primary winding 40 lies.

LIST OF REFERENCE NUMBERS

10

 cylinder

11

 cylinder surface

20

reciprocating

21

 piston crown

22

 piston shaft

30

 injection

31

 intake valve

32

 outlet valve

33

 combustion chamber

40

 primary

50

 secondary winding

51, 52

 electrode

60

 Control unit, ECU

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

• US 2005/0061294 A1 [0002]
• US 7559319 B2 [0002]
• US 7793634 B2 [0004]
• US 8991356 B2 [0005]
• US 2011/0221208 A1 [0005]
• US 6883507 B2 [0006]

Claims (9)

Ignition system for an internal combustion engine with at least one cylinder ( 10 ), one in the cylinder ( 10 ) reciprocating reciprocating pistons ( 20 ) with a piston bottom ( 21 ) and a combustion chamber ( 33 ) adjacent to the piston head ( 21 ), wherein the ignition system as an electromagnetic ignition system for ignition of a fuel-air mixture in the combustion chamber ( 33 ), characterized by a primary winding ( 40 ) in the cylinder ( 10 ) and at least one secondary winding ( 50 ) in the cylinder ( 10 ) and / or in the reciprocating piston ( 20 ), wherein the at least one secondary winding ( 50 ) with at least two ignition electrodes ( 51 ; 52 ), with which in the combustion chamber ( 33 ) a spark is generated. Ignition system according to claim 1, characterized in that at least one secondary winding ( 50 ) in the cylinder ( 20 ), wherein the secondary winding ( 50 ) with at least two ignition electrodes ( 51 ; 52 ) is connected in the region of the cylinder inner wall. Ignition system according to claim 1, characterized in that at least one secondary winding ( 50 ) in the reciprocating piston ( 20 ), wherein the secondary winding ( 50 ) with at least two ignition electrodes ( 51 ; 52 ) in the region of the piston crown ( 21 ) connected is. Ignition system according to one of the preceding claims 1 to 3, characterized in that the primary winding ( 40 ) in conjunction with a control unit ( 60 ), which is used to control a current flow in the primary winding ( 40 ) is trained. Ignition system according to claim 4, characterized in that the control unit ( 60 ) is adapted to the current flow in the primary winding ( 40 ) so that at the ignition electrodes ( 51 ; 52 ) of the at least one secondary winding ( 50 ) a spark is generated at a given time. Ignition system according to claim 5, characterized in that the time for generating the spark as a function of the position of the reciprocating piston ( 20 ) within the cylinder ( 10 ) is defined. Ignition system according to one of the preceding claims 3 to 6, characterized in that the primary winding ( 40 ) spirally in the cylinder jacket ( 11 ) of the cylinder ( 10 ), while the at least one secondary winding ( 50 ) spirally in the piston skirt ( 22 ) of the reciprocating piston ( 20 ), wherein the primary winding ( 40 ) and the secondary winding ( 50 ) extend coaxially. Internal combustion engine with at least one cylinder ( 10 ), one in the cylinder ( 10 ) reciprocating reciprocating pistons ( 20 ) with a piston bottom ( 21 ) and a combustion chamber ( 33 ) adjacent to the piston head ( 21 ), characterized by an electromagnetic ignition system for igniting the fuel-air mixture in the combustion chamber ( 33 ), which is designed in particular according to one or more of claims 1 to 7. Internal combustion engine according to claim 8, characterized by a plurality of cylinders ( 10 ) with an associated reciprocating piston ( 20 ) and a respective electromagnetic ignition system, wherein the current flow in the primary windings ( 40 ) of the respective ignition system via a central control unit ( 60 ) is controllable.

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