JPH05283876A - Changeover/control machine for electrical machine, especially automobile - Google Patents

Abstract

PURPOSE: To provide an electrical machine which can have a simple structure, save constituent member costs and prevent improper insulation of a printed circuit board by contacting flanged edges of a casing cover and casing bottom with the printed circuit board in a range of an outer edge of the printed circuit board. CONSTITUTION: An electronic circuit is formed on an upper surface 1 of a printed circuit board 10 and is covered with a pan-shaped casing cover 18. A sidwall 21 has a continuous flanged edge 22, which is contacted with an outer end of the board 10. For this reason, the outer edge part of the board 10 has no circuit configuration member and no conductive path. Since a lower face 24 of a bent green section 23 is in the same plane as a lower face 25 of the board 10, the board is said to be embedded. A lower face 25 of the board 10 is surrounded by a pan-shaped casing bottom 26, so that a flanged edge 28 comes into contact with the outer end of the lower face 25 of the board 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric machine of the type described in the superordinate concept of claim 1.

[0002]

2. Description of the Related Art In an electric machine of this type known from U.S. Pat. No. 4,811,165, printed wiring boards are used as cooling and reinforcing elements, especially when the printed wiring boards are constructed as conductor sheets. It is provided on the substrate.

In this case, the printed wiring board has a base surface smaller than that of the board, and the free edge area of the board is brought into contact with the casing bottom or the annular edge of the casing cover.

By using such a substrate,
Significant insulation problems arise when the circuit elements are arranged on the printed wiring board in a wiring configuration.

In the case of printed wiring boards of the two-layer technology as well, considerable costs are required for insulation.

Moreover, the use of such a substrate already results in a significant increase in material and manufacturing costs.

Furthermore, it is known to connect a printed wiring board to a casing bottom or a casing cover, in which case the printed wiring board is fixed to the casing component at a distance from the casing component.

For this purpose, a suitable housing component has a spacer, which is in contact with the printed wiring board and which is provided with a fixing element.

The spacers and fixing members are also used as additional components cooperating with suitable fixing devices of suitable casing components.

This type of fastening, in the form of a rack, on and / or on the casing component is complicated and requires considerable component costs.

[0011]

The object of the present invention is to avoid the above-mentioned drawbacks.

[0012]

According to the invention, the above-mentioned problems are solved by an electric machine according to the invention having the features defined in the characterizing part of claim 1.

[0013]

The advantages of the electric machine according to the invention are that the structure is simple, the component costs are reduced and the insulation problem of the printed wiring board is avoided.

The electric machine according to the invention is particularly inexpensive to manufacture, since the component costs are significantly reduced.

Advantageous configurations of the invention are described in the other claims.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An electrical switching or control machine comprises a printed wiring board 10 on the upper surface 11 of which an electronic circuit is provided, of which some electronic components 12, 14 is shown.

These components may be configured as conventional wiring components 12 in which connecting wires 13 project through suitable soldering openings in the printed wiring board, or as SMD / components (surface mounting members) 14. it can.

Further, on the upper surface 11 of the printed wiring board 10, a front end surface 15 of the printed wiring board is provided with an insertion strip 16 known per se, and the connecting piece 17 of the insertion strip 16 is a printed wiring board. 10 to the electronic circuit.

The upper surface 11 of the printed wiring board 10 is covered with a pan-shaped casing cover 18, and a notch 20 surrounding the insertion strip 16 is provided in the front end wall 19 of the casing cover.

The other side wall 21 has a continuous brim-shaped edge 22 which is in contact with the outer area of the printed wiring board 10. For this purpose, the printed wiring board 10
No circuit components and conductor tracks are provided in the outer edge region of the.

The continuous edge 22 has a bent edge section 23 which extends parallel to the respective side wall 21 and which surrounds the end face of the printed wiring board 10.

The lower surface 24 of this bent edge section 23
Is coplanar with the lower surface 25 of the printed wiring board 10, the printed wiring board 10 is, so to speak, embedded.

The lower surface 25 of the printed wiring board 10 is likewise surrounded by a pan-shaped casing bottom 26,
The side wall 27 at the bottom of the casing has a continuous brim-shaped edge portion 28, and the edge portion 28 is provided on the printed wiring board 10.
Is in contact with the outer area of the lower surface 25 of the.

Since the edge 28 projects from the printed wiring board 10, the edge 28 contacts the edge section 23 of the casing cover 18 and surrounds the printed wiring board 10.

The edges of the casing cover 18 and the casing bottom portion 26 have a large number of aligned holes 29 that also penetrate the printed wiring board 10, and the casing cover 18, printed wiring board 10 and A screw 30 is inserted which immovably connects the casing bottom 26 to each other.

Casing cover 18, printed wiring board 1
Space 3 surrounded by 0 and insert strips 16
2 is connected to a space 33 formed by the casing bottom portion 26 and the printed wiring board 10 through a hole 32 in the printed wiring board 10 for pressure compensation.

Casing cover 18 and printed wiring board 1
0 and the casing bottom portion 26 are screwed to each other, and the casing cover 18, the printed wiring board 10 and the casing bottom portion 26 are bonded, soldered, flanged, or riveted by using a locking member or another coupling technique. Can be fixedly connected to each other.

Each of the annular edges and the printed wiring board 1
The bonded body can be sealed by applying an adhesive in a ring shape between 0 and 0.

The casing cover 18 and the casing bottom 26 are preferably made of a material with good thermal conductivity, for example metal, a blister with a metallic coating or the like.

Due to the fact that the edge 28 of the casing bottom 26 and the edge section 23 of the casing cover 18 overlap one another, temperature compensation can be carried out between the casing bottom 26 and the casing cover. At the same time, the printed wiring board 10 is covered so as to be surrounded.

In order to guarantee a satisfactory heat transfer between the casing and the printed wiring board, the printed wiring board 10
Can be provided with a heat-conducting layer, for example a copper coating, a tin layer or a heat-conducting paste, in the edge region or in the bearing region of the casing cover and the casing bottom.

In the case of a shielding effect (improvement of electromagnetic compatibility) by the casing, the casing cover and the casing bottom are preferably electrically conductive and electrically conductively connected to one another.

If the electronic circuit on the printed wiring board 10 has an output component that produces a significant amount of heat, this output component is preferably located near the outer edge of the printed wiring board and the heat For ejection, it is connected to the casing cover or the casing bottom through the aforementioned layers of the printed wiring board.

The electronic circuit is, for example, a type TO220, TO
When having 218 output components, the output components are arranged on the printed wiring board such that the back surface is in surface contact and the cooling strips face the edges of the printed wiring board. And is advantageous.

In this case, the output component is arranged outside towards the edge of the printed wiring board so that the cooling strip is clamped between the printed wiring board and the contacting brim edge of the casing cover 18. It

This allows direct heat transfer to the respective casing component.

A spring of U-shaped cross section can be externally applied to the casing edge in order to make the housing component and the assembly consisting of the cooling piece of the output component and the printed wiring board in close contact.

The edge sections which immovably clamp the output component can be electrically insulated, for example by means of films, rack coatings, alumite layers or ceramic layers.

If the annular edge is enlarged at a defined point, this enlarged section can be designed as a fixed tongue, by means of which the electric machine can be fixed at the installation point.

In the case of an electric machine, unlike the above-mentioned embodiments, the printed wiring board can be constructed in the two-layer technique or as a conductor sheet.

In the case of being embodied as a conductor sheet, the casing cover is preferably glued to the conductor sheet after the conductor sheet has been installed, so that the conductor sheet is rigidly connected to the casing cover on all sides and thus mechanically stabilized.

The conductor sheet is immovably fixed because the combination is closed by the adhesion of the casing bottom. For this purpose, the casing cover is appropriately configured, that is to say the annular edge section 23 is appropriately adapted, i.e. formed short, or the casing cover is constructed without the appropriate annular edge section.

The electrical machine's sandwich-like structure provides a mechanically stable structure which can be manufactured simply and inexpensively with a minimal number of components.

The embodiment shown in FIG. 2 differs from the above-mentioned embodiments in the structure of the printed wiring board and the type of connection between the casing bottom and the casing cover.

The printed wiring board 10A comprises a support plate 35 having conductor paths on the upper surface 11A and the lower surface 25A. The support plate 35 is a ceramic substrate known per se in which the conductor tracks are provided, for example, by screen printing.

On the upper surface 11A and the lower surface 25A, SMD
An electronic component 14A is provided which is designed as a component or chip component and is connected to the conductor track in a manner known per se.

Some electronic components are output components that are significantly heated during operation. This output component 36 is preferably arranged in the edge region of the printed wiring board 10A, so that the heat generated is guided in a short path through the ceramic substrate (support plate 35) to the casing bottom or casing cover.

The casing cover 18A and the casing bottom portion 26A are constructed in substantially the same manner as in the above-described embodiment, but are different only in the fixing or coupling type.

In the casing cover 18A and the casing bottom 26A, the holes 28 and suitable screws are omitted, and instead the edges 22A, 28A are provided with spring members 37.
Surrounded by.

The spring members 37 have a substantially U-shaped cross section and preferably extend over substantially the entire length of the casing side. However, it is also possible to provide a large number of individual spring elements on the side of the casing.

The support plate 35 or the ceramic substrate is fixed at the edges by means of the described construction of the casing bottom and the casing cover and is suitably bearing stable against vibration.

At the same time, heat can be conducted from the support plate to the casing. For this purpose, the heat-dissipating output component, which is preferably (as already mentioned), is provided in the edge region of the ceramic substrate (support plate 35).

By using a ceramic substrate, the insulating means can be dispensed with if the surface is appropriately shaped, if output components are used in which the cooling strips have different voltages.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a first embodiment of an electric machine according to the present invention.

FIG. 2 is a schematic cross-sectional view of a second embodiment of an electric machine according to the present invention.

[Explanation of symbols]

 10, 10A Printed wiring board 11, 11A Upper surface 12, 14, 14A Constituent element 13 Connection wire 15 End face 16 Insertion strip 17 Connection piece 18, 18A Casing cover 19 End wall 20 Notch 21, 27 Side wall 22, 22A, 28, 28A Edge 23 Edge division 24,25,25A Lower surface 26,26A Casing bottom 29,32 Hole 30 Screw 31,33 Space 35 Support plate 36 Output component 37 Spring member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Thomas Zutter Germany Federal Republic of Oberleik Singen Selsheimer Strasse 4 (72) Inventor Dieter Husman Germany Steinheim Richter Wagner Strasse 33 (72) Inventor Dieter Kal Germany Federal Republic Tiefenbronn Melikestraße 10 (72) Inventor Daniela Zavatsky Germany Bad Liebenzel Stuttgarter Strasse 40 (72) Inventor Karlshup Germany Pforzheim Auf der Rotplatte 29 (72) Inventor Halalt Kuntz Germany Republic Crailsheim Base-Gepha Door and Bahnhofstrasse 4

Claims (10)

[Claims] 1. A switching or control machine for electric machines, in particular motor vehicles, in which at least one printed wiring board (10, 10A) carrying electronic circuits is arranged in a casing, which casing comprises at least one. It has one hood-shaped casing cover (18, 18A) and a hood-shaped casing bottom (26, 26A), and has a casing cover (18, 18A) and a casing bottom (2
6, 26A) each has one brim-shaped edge area (2
2, 22A; 28, 28A), the casing cover (18, 18A) and the casing bottom (26, 26A) having a brim-like edge area (22,
22A; 28, 28A) is a printed wiring board (10, 10)
An electric machine, which is in contact with a printed wiring board in the outer edge region of A). 2. The electric machine according to claim 1, wherein the printed wiring board is configured as a conductor sheet. 3. The printed wiring board (10, 10A) has an edge area (22, 22A) of at least a casing cover (18, 18A) and a casing bottom (26, 26A).
28, 28A), the electric machine according to claim 1 or 2, having a layer of a material with good thermal conductivity. 4. The electric machine according to claim 1, wherein the casing cover (18, 18A) and the casing bottom (26, 26A) are connected so as to transfer heat to each other. 5. A casing cover (18, 18A) and a casing bottom (26, 26A) having edge areas (23, 24, 28) in contact with one another. The described electric machine. 6. The electronic circuit has an output component which dissipates heat, the cooling piece of which is clamped between the printed wiring board and the contacting edge region of the casing cover or bottom of the casing. The electric machine according to any one of claims 1 to 5, wherein: 7. An edge portion (22, 22A) of a casing cover (18, 18A) and a casing bottom portion (26, 26).
7. The electric machine according to claim 1, wherein the edge (28, 28A) of A) is surrounded by at least one spring. 8. The printed wiring board (10A) is a support plate (3).
An electric machine according to any one of claims 1 to 7, which has a ceramic substrate as 5). 9. An electric machine according to claim 8, wherein conductor tracks are printed on the ceramic substrate. 10. Electric according to any one of claims 1 to 9, characterized in that the heated output component (36) of the electronic circuit is arranged in the edge region of the printed wiring board (10, 10A). machine.