Electrical circuit.

p0001The invention relates to an electrical circuit arrangement, in particular for use in the region of the drive train of a motor vehicle, and a driveline of a motor vehicle.

p0002It is known to construct electrical circuits in such a way that on a support member, for example, Pertinax or epoxy glass material, conductor tracks can be applied in copper by means of an additive or subtractive.

p0003Circuitry constructed in this way can also be used from about 125 ° C up to a maximum temperature. While at higher temperatures, most electrical components, in particular passive components, their function can not meet satisfactorily, there is a risk that the mechanical structure of the circuit is damaged and consequently adversely affect the electrical connections.

p0004In particular in the field of automotive sensors, such as the engine or transmission circuitry are needed that not only can withstand higher temperatures, but also at high temperatures will be fully functional.

p0005It is therefore the object of the present invention to provide a circuit arrangement that can also be used at higher temperatures.

p0006This object is achieved by an electric circuit arrangement having a made of a temperature-resistant plastic support element, an associated conductor path arrangement and electrical components, wherein the strip conductor arrangement is constructed as a shaped sheet metal part and the terminals of the electrical components is welded to the sheet metal part is.

p0007This electrical circuitry may be used due to the higher temperature resistance of its parts and the high temperature resistance of the applied connection technology between parts in high temperature ranges. The support member of a temperature-resistant plastic, for example, consist in particular glass fiber reinforced polyamide or polyester imide and may be made by injection molding. Such a support element is still operational even in temperature ranges which are above 125 ° C. Even the material forming the interconnect arrangement sheet metal part is also heat-resistant and fully functional at high temperatures. The same is true for the electrical components. The welds between components and sheet metal part also withstand higher temperatures.

p0008It has proven advantageous that the sheet metal part is designed as Blechstanz- and / or punched sheet metal part. The manufacturing method of punching and subsequent bending of the punched sheet-metal molded parts is economical and technically precise perform. Furthermore, this production method is great variability and a great adaptability in the production of various interconnect arrangements.

p0009It has proven that the sheet molding part lies flat on the support element at least. Through this area contact the sheet metal part on the support element, the circuit arrangement against vibrations in the field of automotive sensors require particular special attention, insensitive.

p0010Of particular advantage is that the support element has projections which engage through openings in the sheet metal part and are heißverstemmt with the sheet metal part. In the preparation of the support member by injection molding, the projections on the support member in the same operation are formed with. The corresponding to these projections openings in the sheet metal part to be punched during the stamping operation in the sheet metal part, so that no additional labor is required for the production of the openings. By caused by the Heißverstemmung positive engagement between the carrier element and formed sheet metal part, a reliable connection between the carrier element and formed sheet metal part is ensured.

p0011In an alternative embodiment, it has been proven that the sheet metal part is injected. Here, the sheet metal part is placed in an injection mold and then partially surrounded with plastic material. This technique is particularly appropriate if, for example, the width of the conductor tracks is low and punched openings for stability reasons are not advisable.

p0012It has proved, furthermore, that the connections of the electrical components are laser-welded to the sheet metal part. This joining technique has the advantage that a high strength at high temperatures is achieved without flux. The components are spot-welded to the sheet metal part, without causing a costly and cumbersome to be placed welding electrode must be used.

p0013Of particular utility is when a component is designed as a sensor. Thus, the circuit of the invention can be used in areas where variable measured quantities must be detected at high temperatures.

p0014It is advantageous in this case if the sensor is a motion sensor. Due to this design of the circuit arrangement, it is possible that changing movement sequences can be detected by engineering components that take in operation high temperatures.

p0015It has proven itself that at least one of the electrical components is designed as a Hall sensor. Especially in automotive sensor technology, where the moving parts are usually formed from metal, stretching movements can be easily and without contact detect.

p0016It is highly advantageous to equip the working train of a motor vehicle, having a sensor which is arranged in an inventive circuit arrangement and the rotational speed of a part of the drive train generated corresponding signal, wherein the circuit arrangement is arranged in a region of high temperature. Thus, the circuit of the invention for measuring the speed of a portion of the working strand can be used regardless of the measurement point on the prevailing temperature conditions. Thus, to better monitor the changes in the speed of part of the strand possible and at the point at which were not previously possible due to extreme temperatures measurements. The temperature-resistant construction of the electrical circuit of the invention is a susceptibility to interference is not to be feared.

p0017It has proven particularly useful here that the circuit arrangement is arranged in an engine. By direct arrangement of the circuit arrangement at the motor directly measurements of the speed can be carried out there. This can be avoided by long transmission paths measurement errors. The quality of the measurements is thereby considerably increased.

p0018This is particularly true when the engine is an internal combustion engine. At an engine prevail especially extreme temperature conditions. The implementation of speed measurements on an internal combustion engine is particularly favored by the use of the circuit arrangement according to the invention.

p0019It has proved, moreover, that the circuit arrangement is disposed in a transmission. Here, in addition to the temperature resistance of the circuit arrangement also their resistance has proven to vibration due to the flat pad of the conductor arrangement on the support member.

p0020It has been found that the temperature at the work string can be greater than 125 ° C. Even at these high temperatures, the circuit of the invention operates without interference, and generates the speed of the engine of a motor vehicle corresponding signals.

p0021The invention is described below with reference to a preferred embodiment in conjunction with the drawing. Therein:<dl id="dl0001"><dt>Fig. 1</dt><dd>an embodiment of a sheet metal part of the invention (in plan view) and</dd><dt>FIG. 2</dt><dd>a representation of a finished electrical circuitry.</dd></dl>

p0022The sheet metal part 1 is a punched sheet metal part and has three terminals 2, 3, 4, which are connected to webs 5, 6, 7th each L-shaped branches from 8, 9, the ends of the webs 5, 7 branches with their longer legs 10, 11 in height of a bending line 12th From the web 6 branch off approximately at the height of the branches 8, 9 on both sides of L-shaped branches 13, 14 in opposite directions. The branches 8, 9 and 13, 14 on its end integrally formed on both sides in each case brackets, which serve the assembly of the circuit arrangement for holding connections of components and are bent for this purpose. The regions 21, 22 are punched in the sheet metal part shown in FIG. 1. The web 6, which separates the regions 21, 22 from each other, carries at its end a rectangular detent 23, which also serves in the assembly for mounting of component leads.

p0023Offset relative to the webs 5, 7 and further to the free punched areas 21, 22 extend parallel to the web 6 the webs 24, 25 which are angled at its end. On her, facing to the terminals 2 to 4 ends carry L-shaped, outwardly extending legs 26, 27 with brackets 28, 29 at their ends. In the area of ​​these supports 28, 29 parallel to the bending line 12, another bend line runs 30. The bending lines 12 and 30 divide the sheet metal part 1 in the three regions I, II and III.

p0024During assembly of the circuitry of the region I of the plane upward and the area III bent back until they come to lie in a perpendicular (range I) or parallel (region III) extending to the plane level. The web 6 carries apertures 32 which engage in the projections of a carrier element. The support element and the sheet metal part 1 can then be heißverstemmt each other, ie, the metal part is placed on the support element, after which the openings 34 through cross projections are pressed together under heat. This forms a rivet-like connection.

p0025In FIG. 2, the finished circuitry is shown. The altered by bending portions of the sheet metal part 1 are marked with a superscript bar.

p0026With a support member 31, the sheet metal part shown in FIG. 1 1 ', which has been bent prior to the assembly along the bending lines 12, 30 is heißverstemmt. The terminals 2 ', 3', 4 'are connected to three wires 36, 37, 38 of a cable 39 which is locked by means of a carrying 40th Between the legs 10 of the web 5 and the leg 26 of the bridge 24, a resistor R₁ is arranged in Fig. 1 as an electrical component. It lies with its connections 41, 42 on the legs 10, 26 and is ', 28' fixed with the aid of the brackets 17th In the stamped-out areas 21, 22 are also components, namely capacitors C₂ and C₃, respectively. The component C₂, with its terminals 43, 44 on the branch 13 of the web 6 and on the leg 26 and is held by the holders 18 ', 32'. The component C₃ is located with its connections 45, 46 on the fork 14 and the leg 27 and is ', 33' retained on the brackets 19th Terminals 47, 48 of a further component R₄ are in Fig. 2 on the legs 11 of the web 7 and the leg 27 of the web 25th Holders 20 ', 29' provide the necessary fixation.

p0027As a further component, a Hall sensor 49 is disposed in the circuit arrangement of Fig. 2, which is locked on the detent 23 'and in the angled ends of the webs 24, 25. All connections of the components of the circuit arrangement are laser welded to their respective holders.