US3566851A

US3566851A - Magneto for multicylinder engines of automotive vehicles

Info

Publication number: US3566851A
Application number: US800997A
Authority: US
Inventors: Gustav Pfrommer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1968-03-07
Filing date: 1969-02-20
Publication date: 1971-03-02
Anticipated expiration: 1988-03-02
Also published as: DE1663168C3; FR1597827A; DE1663168A1; SE339143B; GB1258616A; DE1663168B2

Abstract

A rotating magnet-type magnetos for use with multicylinder engines of automotive vehicles wherein a rotor with several equidistant radially magnetized permanent magnets carries a breaker cam which opens one of two sets of breaker contacts when the other set is closed and vice versa. Each set of breaker contacts is connected with one end of a winding in one of two armatures which are mounted on a stationary plate adjacent to the path of movement of permanent magnets. The armatures overlie each other and are magnetically connected in parallel with each other. The other end of each winding is connected with the ignition coil. The plate carries an auxiliary armature which can supply current to the lighting system of the vehicle.

Description

United States Patent 72 Inventor Gustav Phommer 2,569,461 10/1951 Dingman 310/153 Stuttgart-Oberturkheim, Germany 2,761,996 9/1956 Dingman.... l23/148AC [21] AppLNo. 800,997 2,790,914 4/1957 Dingman.... 123/148AC [22] Filed Feb. 20, 1969 2,930,826 3/1960 Dingman 123/149 [45] Patented Mar. 2, 1971 3,034,005 5/1962 Carr 310/153 [73] Asslgnee 5 2: i z Gmbn Primary ExaminerD. F. Duggan 32] Priority g g Assistant Examiner-R. Skudy 3 3 1 Germany AttorneyM1 chael S. Striker P 16 63 168.8

[5 4] MAGNETO FOR MULTICYLINDER ENGINES 0F 1 70.1, 68, 74, 72,153,156, 67, 171; 315/218; 322/91; 123/149, 148 (AC), 149 (D) [56] References Cited UNITED STATES PATENTS 1,507,307 9/1924 Chryst 310/70 ABSTRACT: A rotating magnet-type magnetos for use with multicylinder engines of automotive vehicles wherein a rotor with several equidistant radially magnetized permanent magnets carries a breaker cam which opens one of two sets of breaker contacts when the other set is closed and vice versa. Each set of breaker contacts is connected with one end of a winding in one of two armatures which are mounted on a stationary plate adjacent to the path of movement of permanent magnets. The annatures overlie each other and are magnetically connected in parallel with each other. The other end of each winding is connected with the ignition coil. The plate carries an auxiliary armature which can supply current to the lighting system of the vehicle.

Pmmmm 2m 3566.851

INVENTOR Gustav PFROMMEF? BY his AT TORNEY BACKGROUND OF THE INVENTION The present invention relates to magnetos in general, and more particularly to improvements in rotating magnet-type magnetos. Still more particularly, the invention relates to improvements in rotating magnet-type magnetos for use in connection with multicylinder internal combustion engines of automotive vehicles or the like.

In presently known rotary magnet-type magnetos wherein the rotor constitutes a flywheel and rotates with reference to stationary armatures for generation of ignition energy, the armatures are mounted on a stationary supporting plate in such a way that they are located diametrically opposite each other. Auxiliary armatures for the generation of current which is needed by the lighting system or by other consumers of electrical energy are mounted above the ignition armatures. In other words, the auxiliary armatures are magnetically in parallel with the ignition armatures which is undesirable because, depending on the load on auxiliary armature s, they reduce the ignition voltage to a greater or lesser extent.

SUMMARY OF THE INVENTION An object of my invention is to provide a rotary magnettype magneto wherein the auxiliary armature or armatures are magnetically uncoupled from the ignition armatures.

Another object of the invention is to provide a magneto of the just described type wherein the ignition voltage is not influenced by the load on auxiliary armature or armatures.

A further object of the invention is to provide a magneto, particularly a rotary magnet-type magneto for use with multicylinder internal combustion engines, wherein the ignition armatures and the auxiliary armatures (if needed) are mounted in a novel and improved way so that one ignition armature can exert beneficial influence on the other ignition armature or vice versa and that the generation of ignition current is not affected by the load upon the auxiliary armature or armatures.

The improved magneto is particularly suited for use in connection with multicylinder internal combustion engines (for example, 2-stroke cycle 2-cylinder engines or 4-cylinder engines). It comprises stationary support means (preferably a plate or the like which can be mounted on the crankcase of the internal combustion engine), rotor means including permanent magnet means (for example, four equidistant radially magnetized permanent magnets), a pair of ignition armatures mounted on the support means adjacent to the path of movement of the permanent magnet means and magnetically connected in parallel with each other, a pair of breaker means provided on the support means and each connected with one of the armatures, each of the breaker means having an open and a closed position, and rotary cam means (preferably integral with or rigidly connected to the rotor means) for opening one of the breaker means when the other breaker means is closed, and vice versa. It is preferred to mount the ignition armatures on the support means one over the other at one side of the cam means, and to mount an auxiliary armature for generation of current for the lighting system or two additional overlapping ignition armatures on the same support means substantially diametrically opposite the first-mentioned ignition armatures. If the support means carries only one pair of ignition armatures, it can support one or more auxiliary annatures each of which can furnish electrical energy to a separate consumer.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved magneto itself, however, both as to its constructionand its mode of operation, together with additional'features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a magneto for use in connection with a 2-cylinder 2-stroke cycle internal combustion engine; and

FIG. 2 is a fragmentary sectional view as seen in the direction of arrows from the line lI-II of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawing in detail, there is shown a rotary magnet-type magneto which comprises a rotor 10 with four equidistant radially magnetized permanent magnets 11 and a supporting plate 12 for ignition armatures 13 (FIG. 2) which supply ignition current. The plate 12 further supports a third or auxiliary armature 14 which delivers current for the lighting system, two breaker means each including a lever 15, and two capacitors 16 each in parallel with one of the breaker means. The plate 12 is screwed or otherwise affixed to the crankcase (not shown) of a 2-stroke cycle 2-cylinder internal combustion engine which includes a crankshaft 17 having one of its ends connected to the hub 18 of the rotor 10. This rotor constitutes a flywheel and its hub 17 constitutes a breaker cam which pivots the breaker levers 15 in response to rotation of the shaft 17 and has a closing angle of 230. The breaker levers 15 are mounted on the plate 12 diametrically opposite each other with reference to the axis of the shaft 17.

Each of the armatures 13 comprises a laminated core 19 which is surrounded by a winding 20. One end of each winding 20 is connected with the primary winding of an ignition coil (not shown) by a first conductor cable 21 and the other end of each winding 20 is connected with the corresponding breaker means and with the associated capacitor 16 by a conductor 22. As stated before, the capacitors 16 are connected in parallel with the corresponding breaker means. When the rotor 10 is driven by the shaft 17, an alternating magnetic flux develops in the cores of the

armatures

13 and 14 to thereby induce an alternating current voltage in the windings 20 and in the winding 24 of the auxiliary armature 14.

FIG. 2 shows that the armatures 13 are mounted on the plate 12 in such a way that one thereof overlaps or overlies the other. In other words, they are magnetically connected in parallel with each other. Since the breaker levers 15 are located diametrically opposite each other, and due to the particular shape of breaker cam 18, one of the breaker means is closed when the other breaker means is open, and vice versa. When one of the breaker means is open at the moment of ignition, the magnetic flux escapes from the armature 13 which is associated with the closed breaker means into the armature 13 which is associated with the open breaker means. This contributes to an increase in ignition energy which is supplied to the aforementioned ignition coil.

The auxiliary armature 14 is mounted on the plate 12 diametrically opposite the ignition armatures 13. In this way, the armature 14 is magnetically uncoupled from the armatures 13. It comprises a laminated iron core 23 and the aforementioned winding 24 having two terminals 25 for connection to the lighting system and/or to other consumers of electrical energy. 1

In accordance with a slight modification of the embodiment shown in FIGS. 1 and 2, the aforementioned nonillustrated ignition coil can be omitted if the armatures 13 are provided with primary and secondary windings. Also, the magneto can be modified for use in connection with 4-cylinder internal combustion engines. The armature 14 is then replaced by two additional superimposed ignition armatures 13 which are magnetically in parallel with each other. Such modified magnetos normally do not employ any auxiliary armatures.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art.

Iclaim:

I. In a magneto, particularly in a magneto formulticylinder internal combustion engines, a combination comprising stationary support means; rotor means including permanent magnet means; a pair of ignition armatures mounted on said support means adjacent to the path of movement of said magnet means and magnetically connected in parallel with each other, each of said armatures comprising a winding; a pair of breaker means each connected with the winding of one of said armatures and each having an open and a closed position; and rotary cam means for opening one of said breaker means when the other breaker means is closed, and vice versa. 7

2. A combination as defined in claim 1, wherein said ignition armatures overlie each other.

3. A combination as defined in claim 2, further comprising auxiliary armature means provided on said support means and located opposite said overlying armatures with reference to the axis of said rotor means.

4. A combination as defined in claim 1, wherein said cam means is rigid with said rotor means.

5. A combination as defined in claim 4, wherein said breaker means are located diametrically opposite each other with reference to the axis of said rotor means.

6. A combination as defined in claim 1, wherein each of said ignition armatures further comprises a core mounted on said support means and wherein each of said windings surrounds the respective core, each of said windings having two ends one of which is connected to one of said breaker means and a second end, and further comprising a pair of capacitor means each connected with the one end of one of said windings in parallel with the respective breaker means.

7. A combination as defined in claim 1, wherein said permanent magnet means comprises a plurality of equidistant radially magnetized permanent magnets.

8 A combination as defined in claim 7, wherein each of said armatures further comprises a laminated core surrounded by the respective winding and inwardly adjacent to the path of movement of said permanent magnets.

9. A combination as defined in claim 1, wherein said cam means constitute the hub of said rotor means.

10. A combination as defined in claim 1, wherein said rotor means constitutes a flywheel.

Claims

1. In a magneto, particularly in a magneto for multicylinder internal combustion engines, a combination comprising stationary support means; rotor means including permanent magnet means; a pair of ignition armatures mounted on said support means adjacent to the path of movement of said magnet means and magnetically connected in parallel with each other, each of said armatures comprising a winding; a pair of breaker means each connected with the winding of one of said armatures and each having an open and a closed position; and rotary cam means for opening one of said breaker means when the other breaker means is closed, and vice versa.

8. A combination as defined in claim 7, wherein each of said armatures further comprises a laminated core surrounded by the respective winding and inwardly adjacent to the path of movement of said permanent magnets.