IGNITION DEVICE

Abstract

An ignition device for an internal combustion engine, having a housing in which a crankshaft sensor is accommodated for detecting the rotational speed and/or the position of a crankshaft, which is in particular provided with a toothed position sensor and in which at least one ignition transformer with a primary winding is accommodated, and a secondary winding for generating a spark for the internal combustion engine is accommodated, wherein a number of input ports, in particular for the connection of an electrical energy source for supplying the or each ignition transformer and/or for supplying sensor and/or control signals, and in which a plurality of output ports, in particular for connecting at least one spark plug and/or for emitting control signals, are provided.

Claims

1. An ignition device for an internal combustion engine, the ignition device comprising: a housing; a crankshaft sensor for detecting a rotational speed and/or a position of a crankshaft provided with a toothed position sensor; at least one ignition transformer having a primary winding and having a secondary winding for generating an ignition spark for the internal combustion engine; at least one input port for connecting an electrical power source for supplying the ignition transformer and/or for supplying a sensor and/or control signal; and at least one output port for connecting at least one spark plug and/or for emitting a control signal.

2. The ignition device according to claim 1, wherein the crankshaft sensor is a Hall sensor.

3. The ignition device according to claim 1, wherein an interface to the crankshaft sensor is accommodated in the housing, the interface being routed inside the housing to the at least one input port.

4. The ignition device according to claim 1, further comprising an electromagnetic shield of the crankshaft sensor being integrated in the housing.

5. The ignition device according to claim 1, wherein a single ignition transformer, which on a primary side is connected to a housing-internal actuator, in particular an H-bridge, and on a secondary side to the at least one output port.

6. The ignition device according to claim 5, wherein, in the housing, a control unit is integrated, which on an input side is routed to the at least one input port, and is routed housing internally to the interface, and on an outlet side, is routed to a housing-internal actuator for a primary winding of the ignition transformer.

7. The ignition device according to claim 5, further comprising a current path connected in parallel to the secondary winding of the ignition transformer, having two diodes interconnected in a forward direction of which a center tap is routed to a further output port for grounding.

8. The ignition device according to claim 1, wherein two ignition transformers are accommodated in the housing, of which the primary windings are routed to an energy source via input ports and to a respective input port for an external control unit, and of which the secondary windings are routed to output ports for the each spark plug.

9. The ignition device according to claim 1, wherein the ignition transformer comprises a high voltage diode with a forward direction from the corresponding secondary winding to the corresponding primary winding, wherein the high voltage diode is routed on a cathode side to the input port leading to the power source.

10. The ignition device according to claim 1, wherein the crankshaft sensor is accommodated in a housing pocket with a pocket bottom located on the crankshaft side.

11. The ignition device according to claim 1, wherein the housing comprises intakes for a mount for mounting on existing attachment points of a cylinder of an internal combustion engine or on a respective attachment point of two cylinders of a V-type internal combustion engine.

12. The ignition device according to claim 1, wherein the housing with at least the crankshaft sensor and ignition transformer disposed therein is cast with a potting compound.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0039] FIG. 1 is a schematic representation of the ignition device, having a housing, in which at least one crankshaft sensor and an ignition transformer arrangement are accommodated, wherein the crankshaft sensor is arranged in a housing pocket,

[0040] FIG. 2 is a block diagram of an ignition device according to FIG. 1, wherein the ignition transformer arrangement comprises an ignition transformer which is connected to a housing-internal actuator, and wherein a control unit is accommodated in the housing,

[0041] FIG. 3 is a perspective view of the ignition device, wherein ports are routed out of the housing by means of a flat conductor cable,

[0042] FIG. 4 is a block diagram of the ignition device according to FIG. 1, wherein an interface to the crankshaft sensor is accommodated, and wherein the ignition transformer arrangement has two ignition transformers,

[0043] FIG. 5 is a plan view of the ignition device, wherein transformer longitudinal axes of the two ignition transformers extend in parallel and are spaced apart and oriented perpendicular to the housing side having the housing pocket,

[0044] FIG. 6 is a perspective view of the ignition device, wherein the two ignition transformers have a shared transformer longitudinal axis which is oriented parallel to the housing side having the housing pocket,

[0045] FIG. 7 illustrates the ignition device in the assembled state on a cylinder of an internal combustion engine, and

[0046] FIG. 8 illustrates the ignition device in the assembled state, wherein the ignition device is attached to two cylinders of the internal combustion engine.

DETAILED DESCRIPTION

[0047] FIG. 1 shows a schematic representation of an ignition device 2. This comprises a housing 4, in which a crankshaft sensor 6 and an ignition transformer arrangement 8 are accommodated. The crankshaft sensor 6 is designed as a Hall sensor. Further, said sensor is arranged in a housing pocket 10, which faces a crankshaft 14 in the assembled state of the ignition device 2 on an internal combustion engine 12 (FIG. 7). In summary, a pocket bottom 10a of the housing pocket 10 is arranged on the crankshaft side. In this case, a position sensor 16 with teeth 18 is coupled to the crankshaft 14 so that the teeth are adjusted during a rotation of the crankshaft 14 by a sensitive region of the crankshaft sensor 6. This adjustment movement produces a voltage signal of the Hall sensor, which is recorded as a measured value(s). By means of the measured values, the rotational speed and/or position of the crankshaft 14 is detected. In this case, at least one tooth 18 is omitted for reference purposes.

[0048] The ignition transformer arrangement 8 includes at least one ignition transformer 8a. The or each ignition transformer 8a in turn has a primary winding 8b and a secondary winding 8c, and a (iron) core 8d for generating a spark F on the internal combustion engine 14.

[0049] FIGS. 2 to 7 show two variants of the ignition device 2. According to these variants, further components are accommodated in the housing 4. In FIG. 1, these components are shown in dashed lines. These components are an interface 20 to the crankshaft sensor 6, a control unit 22, and an actuator 24, which is preferably designed as an H-bridge. In addition, an electromagnetic shield 26, which comprises the crankshaft sensor 6 on the inside of the housing, is integrated in the housing 4. By means of this shield 26, the crankshaft sensor 6 is thus in particular shielded from an interference field originating from the ignition transformer arrangement 8.

[0050] Further, three input ports 28 are provided, two of which are used for connecting an electrical power source 30 (FIGS. 2 and 4), which is formed in all embodiments as a battery, and for supplying the or each ignition transformer 8a of the ignition transformer arrangement 8. The other input port 28 is for supplying sensor or control signals from a housing-external sensor or control unit. Furthermore, three output ports 32 are provided. One of the output ports 32 serves to derive a control signal from the interface 20 (FIG. 4, second variant of the ignition device 2) or from the control unit 22 (FIG. 2, first variant of the ignition device 2). The two other output ports 32 are provided for connecting two spark plugs 34.

[0051] According to the embodiments as per the variants shown in FIGS. 2 to 7, these input ports 28 and output ports 32 are shared. In the respective variants, however, additionally corresponding input ports 28 and/or output ports 32 are provided.

[0052] For the purposes of improved high voltage strength, the housing 4, including the components accommodated therein as per the respective embodiment of the ignition device 2, is cast with a potting compound 36.

[0053] FIG. 2 shows a block diagram of the first variant of the ignition device 2. Here, the interface 20 to the crankshaft sensor 6 is accommodated in the housing 4. Said interface is on the one hand routed to the electric power source 30 via the input ports 28. On the other hand, the crankshaft sensor 6 is connected to the interface 20.

[0054] Furthermore, in this embodiment, the ignition transformer arrangement 8 has only one ignition transformer 8a. On the primary side, the latter is connected by the housing-internal actuator 24, and on the secondary side, by the two winding ends of the secondary winding 8c, to in each case one output port 32. A spark plug 34 of a cylinder 38 of the internal combustion engine 12 is connected to each of these two output ports 32. The spark plugs 34 are routed to ground GND.

[0055] In addition, the control unit 22 is accommodated in the housing 4. In this case, the control unit 22 is connected on the input side to the input port 28 for supplying sensor or control signals, and to the energy source 30 via an input port 28. Furthermore, the control unit 28 is connected inside the housing to the interface 20, in particular for supplying measured values detected by the crankshaft sensor 6 or measurement data determined therefrom. Further, the control unit 22 is connected to the actuator 24 for the primary winding 8b of the ignition transformer 8a, in particular for the corresponding control of the actuator 24.

[0056] Further, a current path 40 is connected between the two output ports 32, to which the two spark plugs 34 are connected. Said path is also connected in parallel to the secondary winding 8c of the ignition transformer 8a. In the current path 40, two diodes 42 are connected in series, with their forward direction facing each other. Between these diodes 42, a center tap 44 is connected, which is connected to a further output port 32, which in turn is routed to ground GND.

[0057] The coil end of the secondary winding 8c, to which a positive induced high voltage pulse, illustrated by means of a plus symbol, is applied, leads to ground GND via the output port 32 by virtue of the diode 42 connected in the forward direction. This is represented by an arrow. As a result, no wasted spark is generated by means of the spark plug 34 connected to this coil end.

[0058] FIG. 3 shows a perspective view of an embodiment of the first variant. Here, for the purpose of improved visibility, the potting compound 36 is not shown and the housing 4 is shown transparent. Here, the spark plugs 34 are connected in particular in each case by means of a spark plug cable 46 routed out of the housing 4 to the corresponding output port 32. The input ports 28 and the output ports 32, to which the spark plugs 34 are not connected, lead out of the housing 4 as flat conductor cables 48.

[0059] Furthermore, on the housing side of the housing 4 on which the housing pocket 10 is arranged, a retaining tab 50 is also disposed, in particular integrally formed. This has slot-like recesses 52 acting as intakes for a mount, in which screw elements are received on the combustion engine 12 during mounting of the ignition device 2.

[0060] FIG. 4 shows a block diagram of the second variant of the ignition device 2. In this case, the ignition transformer arrangement 8 has two ignition transformers 8a. Their primary windings 8a are routed to one of the input ports 38 to the power source 30 as well as in each case, to one of the input ports 28 of a rudimentarily shown external control unit 31. Furthermore, their secondary windings each lead to an output port 32 to which a spark plug is connected, which is connected to ground 34.

[0061] Further, the interface 20 accommodated in the housing 4 leads to the output port 32 for emitting a control signal.

[0062] In addition, both ignition transformers 8a each have a high voltage diode 54 to avoid a switch-on spark. For this purpose, in each case the primary winding 8b and the secondary winding 8c of the corresponding ignition transformer 8a are connected by means of the high voltage diode, with the forward direction from the secondary winding 8c to the primary winding 8a. In this case, the high voltage diode 54 is connected to the end of the primary winding 8b, which is connected to the power source 30, and is connected to that end of the secondary winding 8c which does not lead to the corresponding output port 32.

[0063] FIGS. 5 and 6 show the two embodiments of the second variant of the ignition device 2. Analogous to the embodiment of FIG. 3, in this case the potting compound 36 is not shown for improved visibility and the housing 4 is shown transparent. Also analogous to the embodiment according to FIG. 3, two spark plug cables 46 as well as the input ports 38 and the output ports 32, to which the spark plugs 34 are not connected, lead out of the housing as flat conductor cables 48. In addition, the housings 4 of the embodiments of FIGS. 5 and 6 in each case comprise the retaining tab 50 with the recesses 52 for mounting the housing 4 on the internal combustion engine 12.

[0064] According to FIG. 5, the (winding axis) transformer longitudinal axes L of the two ignition transformers 8a are arranged in parallel and at a distance from one another. These further extend perpendicular to the housing side of the housing 4 at which the housing pocket 10 is arranged. In contrast, the transformers 8a of the embodiment of FIG. 6 share a common transformer longitudinal axis L which runs parallel to the housing side, which comprises the housing pocket 10. A magnetic field, which is caused when a current flows through the windings 8c and 8b of one or both ignition transformers, comprises in the embodiment of FIG. 6, in particular in comparison to the embodiment of FIG. 5, a comparatively small magnetic field strength in the region of the crankshaft sensor 6, so that a measuring operation of the crankshaft sensor 6 is less disturbed by this magnetic field.

[0065] In the embodiments of FIGS. 3, 5 and 6, for example, a circuit board 56 is received in the housing 4, by means of which the components in the housing, i.e., at least the crankshaft sensor and the at least one ignition transformer, are interconnected. Further, in these figures, the coupling of the spark plug cables 46 with the appropriate ignition transformers 8a is not further shown.

[0066] FIG. 7 shows the ignition device 2 in the assembled state, on the cylinder 38 of the internal combustion engine 12 shown in sections. The housing 4 is mounted such that the crankshaft sensor 6 accommodated in the housing pocket 10 faces the crankshaft 14 and is able to detect the (metal) teeth 18 of the outlined position sensor 16. Here, the ignition device 2 is in particular attached to existing attachment points 58, which are provided for mounting an (old, non-inventive) ignition device.

[0067] FIG. 8 shows the ignition device 2 in the assembled state on a V-type combustion engine 12. This has two cylinders 38, which are inclined at a (bank) angle to each other with respect to the crankshaft 14. The two cylinders 38 each have two existing attachment points 58, for example, for mounting an (old, not inventive) ignition device. The attachment points 58 are arranged in a shared plane which runs perpendicular to the crankshaft 14.

[0068] The housing 4 of the ignition device 2 is attached to both cylinders 38. For this purpose, an existing attachment point 58 of each cylinder is used in each case. The intakes for the mount formed as recesses 52 are disposed in the retaining tab 50 of the housing 4 in accordance with the positioning of the existing attachment points 58.

[0069] The ignition device 2 is arranged circumferentially of the position sensor 16 in the region of the two cylinders 38.

[0070] The invention is not limited to the embodiments described above. On the contrary, other variants of the invention can be derived by those skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments can also be combined with one another in other ways without departing from the subject matter of the invention.

[0071] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.