DE8114854U1 - INDUCTIVE PULSE - Google Patents

Description

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description

The innovation relates to an inductive pulse generator according to the preamble of the main claim, as it is in the German utility model 78 06 069 is described.

Such pulse generators have metal cores made of metallic and ferritic core materials for induction coils.

The disadvantage of ferritic cores is the fact that they break more easily; this risk of breakage therefore requires a correspondingly gentle manufacturing process, you want to avoid rejects. In addition, arise when using ferritic cores, especially in inductive pulse generators, unsafe and low voltage output j | prey. With the previously used metallic cores S

If the signal delay is too great and thus an impermissibly large dynamic angle error occurs: are simultaneously they are characterized by insufficient corrosion resistance under the operating conditions. These properties are known to have a disadvantageous effect, particularly in the case of inductive pulse generators.

Avoiding the disadvantages shown in the known inductive pulse generators with conventional metal cores were, the object of the invention is to provide inductive pulse generators in which for the metal cores there is no risk of breakage, and in which in a simple and robust manufacturing process the cores can be produced in which safe and high signal voltage yield with justifiable dynamic Angular error can be achieved, and in which the cores simultaneously under normal operating conditions have excellent corrosion resistance.

According to the invention, these tasks are achieved by the inductive Pulse generator according to claims 1 to 9 solved.

The inductive pulse generators according to the invention have a surprising combination of advantageous properties on. By using the stainless steel core are

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the electrical values of the inductive according to the invention Pulse generator much better than the previously known ones. · They ensure reliable and high signal voltage yields achievable with an acceptable dynamic angle error. Their cores are unbreakable and at the same time exhibit excellent Corrosion resistance.

The cores used in the present invention are procedural to be produced in a simple manner by cold forming. In this case, the alloy used according to the invention is used in a manner known per se, a rod-shaped material with a smaller cross-section and greater length than the finished dimensions of the metal core to be produced. By knocking off and cold heading corresponding sections This rod-shaped material is used to create the metal core according to the invention in the desired dimensions. Annealing is used to improve the magnetic properties impaired by cold working in particular at temperatures between 900 ° to 1300 ° C., preferably annealing under protective gas to prevent it the surface oxidation takes place. Despite this surprisingly simple and economical production method products are obtained with the outstanding combination of properties shown.

The invention is explained in more detail with reference to the following figures. Show it:

Fig. 1 shows an inductive pulse generator in section with connecting cable,

Fig. 2 is a plan view of this pulse generator without connecting cable,

Fig. 3 shows the fastening tab.
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An inductive pulse generator 1O consists essentially from a coil carrier 12, a connection unit 14 and a magnetically conductive, preferably metallic fastening strap 16. The coil body 12 has an induction coil 18, which in turn is controlled by a magnetic return element 20 is surrounded. A stainless steel core 22 is inserted into the concentric bore of the bobbin 12, which abuts a central web 24 (see FIG. 3) of the fastening strap 16 with its end face 22a.

The coil carrier 12 with its induction coil 18 and the return path element 20 are made of a plastic 26 enveloped. It is advantageous if the plastic casing 26 overlaps the end face 22b of the stainless steel core 22 Tenth of a millimeter (0.1-0.9 mm) covered. As a result, the stainless steel core 22 is securely held in the concentric bore, without the magnetic field between the stainless steel core 22 and yoke element 20 being significantly weakened. In addition, due to the smooth surface, no impurities can accumulate at this point, which the Might change the strength and direction of the magnetic field.

The edge 12a of the bobbin 12 protrudes over the return element 20 and thus enables a moisture-proof connection with the casing 26. Around the magnetic field In order not to let it scatter too much in the work area, it is expedient to place the return element 20 over the edge 12b of the bobbin 12 also to extend.

The connection unit 14 consists essentially of a half-shell 28 into which a connection cable 30 is placed is. The wires 30a, b of the connecting cable 30 are in recesses 32a, b of the half-shell 28. There they are with the wire ends 18a, b of the induction coil 18 are soldered, which pass through slots 34 in the connection area.

The connection unit 14 and the line 30 inserted therein are made of a shrink tube (not shown)

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held together and encapsulated with plastic (Fig. 1 drawn dashed lines).

During the manufacture of the inductive pulse generator, the fastening tab 16 is placed in an injection mold and overmolded with plastic. It form the coil carrier 12 and the connection unit 14, which via the openings 16a, b formed by the central web 24 with one another are connected.

The induction generator works as follows:

If a voltage is applied to the induction coil 18 via the connecting line 30 is applied, a magnetic field is formed, the field lines of which over a stainless steel core 22, central web 24 and return element 30 are closed. Between the end faces 22b and the return element 30 are the Field lines in the open air, and a guide pin rotating past that z. B. attached to the flywheel of an engine changes the magnetic field, which creates a high voltage pulse in the induction coil. This The voltage pulse is evaluated via line 30 in downstream electronics, depending on the requirements.

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Claims (8)

1. Inductive pulse generator with a fastening strap, ir.it one in the area of the fastening strap with a connection unit connected coil body, which has an induction coil surrounded by a return path element and in which a metal core is concentrically embedded, the fastening tab having a central web (24), and wherein the metal core (22) with its one end face (22a) abuts the central web (24) or at least is in the immediate vicinity Located near the central web (24), characterized in that the metal core is made of Stainless steel consists of 1 to 4% silicon and more than 8% chromium and / or nickel. Beru factory .... , G 1218 2. Inductive pulse generator according to claim 1, characterized characterized in that the coil carrier (12) and the connection unit (14) have openings (16a; 16b) the fastening tab (16) are connected to one another. 3. Inductive pulse generator according to at least one of the preceding claims, characterized in that the plastic casing (26) the The end face (22b) of the stainless steel core (22) is covered with a thin layer. 4. Inductive pulse generator according to one or more of the preceding claims, characterized in that the edge (12a) of the bobbin (12) protrudes beyond the return element (20). Ϊ 5. Inductive pulse generator after one or more ! of the preceding claims, characterized in that g e k e η η - ; records that the return element (20) over • si 20 the edge (12b) of the bobbin (12) is also extended is. 6. Inductive pulse generator according to at least one of the preceding claims, characterized in that net that the core (22) made of an alloy from 1 to 2% silicon, more than 20% chromium and / or nickel, 1% or less manganese, 0.12% or less carbon and otherwise consists of iron. 7. Inductive pulse generator according to at least one of the preceding claims, characterized in that net that the chromium content is 2δ to 31%. 35 Beru factory ... G 1218 -3- 8. Inductive pulse generator according to at least one of the preceding claims, characterized in that that the metal core (22) by knocking off the rod-shaped material of the specified composition with a smaller cross-section and greater length than the corresponding dimensions of the metal core, followed by cold heading to the desired core dimensions and subsequent annealing at preferably temperatures of 900 to 1300 ° C Protective gas is produced.