GB2107882A

GB2107882A - Generator for measured values

Info

Publication number: GB2107882A
Application number: GB08228695A
Authority: GB
Inventors: Ernst Kastler
Original assignee: Kienzle Apparate GmbH
Current assignee: Digital Kienzle Computersysteme GmbH and Co KG
Priority date: 1981-10-17
Filing date: 1982-10-07
Publication date: 1983-05-05
Also published as: DE8130414U1; FR2514931A1; JPH0241755Y2; JPS5881699U

Abstract

A protective bushing 2 having axially parallel guide recesses 3, 4 retains a circuit plate 5 carrying the electrical components 23 of the generator in the generator's housing 1. The circuit plate is secured within the bushing 2 by a casting compound 12. Only the contacting plugs 6, 7 connected to the circuit plate 5 and serving to transmit the measured value project from the casting compound 12. The generator may comprise a pulse generator including an oscillator coil 9 arranged in a core 8 attached to a part 10 connected to plate 5. By means of screw threads 19 and 20 the housing 1 may be attached to a vehicle's gearbox and to a cable respectively. <IMAGE>

Description

SPECIFICATION Generator for measured values The invention relates to a generator for measured values having a bush shaped housing for screw connection, and having a device for supporting the electrical parts of a circuit plate supported in the housing of the generator for the measured values.

When in a generator for the measured values the formation of this value is effected by detuning an oscillator, preferably to one element of the oscillator, that means to the measured value sensor-as this is generally known-the other electrical components of the oscillator and possibly also other signal shaping circuit parts are immediately attributed thereto in order to keep damping and noise at a relatively low level.

Apart from the fact that for many applications in this manner the electrical components forming the measured value are exposed to a lot of vibrations, aggressive substances and also to an essential thermal load, especially in an extreme surrounding, the architecture of such generators for measured values must also take care of handling difficulties when such sensors are mounted at their place of use. This means that the volume of the device must be as small as possible, especially a narrow design is to be achieved. This demand, however, is contrary to the demand to house also the electrical components forming the measured values together with the sensor, certain limitations being given with respect to the distances of the electrical components of each other because of their warming up.Also for such generators for measured values, the conditions of a production in big series have to be taken into consideration, as well as of a possible mechanical mounting and also the demands of a cost minimized adaptability to varying vehicle mounting conditions, as well as sufficient checking possibilities for the function in the mounting state, in which an exchange of parts is possible with the least expenditure.

Already known designs of such generators for measured values at the most fulfill one or the other of the above mentioned conditions. In many cases they are for example very expensive, due to the fact that screw connections are used, or they are expensive to mount, as during the insertion of the electrical components into the generator housing soldering work is required.

It was therefore the object of the invention to design an architecture for a measured value generator of the above kind, which under consideration of the above named conditions of use of such a generator allow for a consequent optimizing of the production and mounting expenses, the possibilities of checking and adapting with respect to the in place mounting conditions.

According to the invention, there is provided an essentially cup shaped protective bushing to be introduced into the housing of the measured value generator and firmly connected to such bushing ax parallel guide recesses, attributed to the circuit plate within the bushing, the circuit plate being secured axially within the protective bushing by means of a casting compound.

Also a preferred embodiment of the invention is characterized, in that the measured values sensor is arranged at a front side of the circuit plate, in that plugging projections serving to transmit the measured values are immediately contacted to the circuit plate and are partially embedded in the casting compound at the front face of the measured value sensor, and that within the housing there is ring shaped shoulder, the protective bushing being provided with a ring shaped flange surface attributed to the ring shaped shoulder, and in that for retaining the protective bushing in its position defined by the ring shaped shoulder and the flange surface within the housing at the front face there is a rim to be flanged off.

It is an essential advantage of the device according to the invention that, despite of the possible narrow construction of the generator housing which allows for the application of a spanner, there is sufficient space for the arrangement of the electrical components. Due to the arrangement of all electrical components on a circuit plate, a module is created which is easy to handle and which may also easily be checked with respect to its function. It is decisive however, that the whole electrical module may be inserted into the protective bushing and may be connected with the latter in a specially simple manner by filling it up respectively casting it with a suitable casting compound. By securing the circuit plate in the protective cover in the chosen manner, there is no danger that the circuit plate is distorted which might easily happen for instance when screwing it in.Also when using the casting compound to fill up the protective bushing, the electrical components are safe against vibration and against the influence of gases.

Also by this mounting method the electrical components of the measured value generator are protected, not only against damages by later mounting procedures but there is also created a module to be stored and sent, such module being universally usable, that means it may be combined with housings of different shape.

Depending on its application, the housings which have generally to be made in a cutting production process and may be made in a completely separate procedure and apart from the electrical parts of the measure value generator. For instance, the housings may be provided with screw or bayonet connecting means for the cable to be attached thereto and may also have different screw windings with respect to fastening the measured value generator. Apart from that, also housings can be applied which are specially designed for a high thermal radiation or which are made from a special material when for instance a high susceptibility against corrosion is required.

It is another advantage that the architecture of the measured value generator according to the invention allows also for an embodiment which may be mounted without using tools, that means that in these cases the demand of parts is largely reduced.

In the following the invention shall be explained in detail, with reference to the drawings. They show: In Fig. 1 a longitudinal section of a preferred embodiment of the measured value generator according to the invention, Fig. 2 is a cross section of the measured value generator according to Fig. 1, Fig. 3 is a section showing the catching means between the protective bushing and the housing, Fig. 4 is a section of another plugging contact arrangement deviating from the preferred embodiment.

From Fig. 1 it may be seen that within the housing 1 proper of the actual measured value generator, which may be for instance a rotational values representing pulse generator attributed to the gearing of a motor vehicle and having an essentially cup shaped protective bushing 2 so to say as a "lining". Within the protective bushing 2 which in the example chosen projects from the housing 1 on the side of its sensor, a circuit plate 5 is retained between guiding recesses 3 and 4 parallely arranged within the protecting housing 2.The bushing carries all electrical components of the measured value generator, that means at this plate there are mounted the electrical components of the oscillator and of the recognising, pulse shaping and amplifying circuit parts switches in series thereto, and marked by the reference No. 23 in their entirety, as well as several contact plugs of which two--6 and 7have been shown as well as also at the front face thereof an oscillator coil 9 arranged in a pot shaped core 8 and serving as a measured value sensor-the two connecting wires of the oscillator coil 9 being provided with the reference No. 26.

To this end there is a part 10 connected to the circuit plate 5, at which there is provided a bolt 11 to take up the cup 8. Naturally the measured value sensor must only be connected to the circuit plate 5 which may be effected also by other means, for instance by sticking, since the circuit plate 5 after it has been checked as to its function, is kept in position within the protective bushing 2 by means of a suitable casting compound 12 shown to be translucent in Fig. 1, and forming the front face of the measured value gdnerator. One may also think of arranging the circuit plate 5 in the middle of the protective bushing 2 mounting the necessary electrical components 23 on both sides thereof, the cup core 8 being immediately taken up by a projection of the circuit plate 5.

The drawing makes clear that the design as chosen gives sufficient space for the arrangement of the electrical components 6, 7, 8, 9 and 23. In this embodiment according to Fig. 1 the fastening of the electrical parts of the measured value generator which have been made as a unit separate of the housing and to be checked as to its function in the housing 1 is effected by flanging off a rim 1 3 provided therefore at the front face of the housing 1. The protective bushing 2 rests by means of a flange shaped projection 14, that means by a flange surface 1 5 arranged at the projection 14 on a ring-shaped shoulder 16 of the housing 1. A tightening means 1 7 between the housing 1 and the protective bushing 2 shall be a bar against gearing oil penetrating therefrom.As a stop for the protective bushing 2 in the housing 1, also the ring-shaped shoulder 1 8 itself can be used, since both parts are designed with the corresponding stepped projections. This means that the housing 1 and the protective bushing 2 can be of straight configuration at its pluggin in front face.

For being complete it should still be mentioned, that the housing 1 in the form of a bushing for screw connection is provided with a first screw thread 19, which serves to fasten the measured value generator in the housing of the vehicle gearbox, and a second screw thread 20 which is attributed to the connecting element of the cable. For applying a mounting tool there is a hexagon part 21 while reference No. 22 is a ringshaped stop surface between the generator and the gearbox housing.

The section according to Fig. 3 shows that the protective bushing 2 can be connected to the housing 1 by means of a catching connection, in that within the housing 1 there is an undercut portion 24, and at the protective bushing 2 a catching rim 25 inclined in such direction, the casting compound 5 being elastic to such an extent by correspondingly dimensioning the hardening component therein.

The plugging-in connection as shown in Fig. 4 is less consequent as regards the desired optimum for production. This, however, can be acceptable when for instance a round contacting plug, one of which has been shown in Fig. 4 with the reference No. 28, can be used. The front facing end of the measured value generator in this case is a flanged-off insulating plate 29, fastened in the housing 1 in which the plugging pins 28 are hollow. The electrical connection between the plugging pins 28 and the circuit plate 5 may be effected by relatively stiff wire elements 27, contacted to the circuit plate 5, and soldered at the other end of the plugging pins 28.

Claims

1. Measured value generator with a bush shaped housing, provided for screw connection and with an electrical circuit plate carrying the electrical components of the measure value generator in the housing, characterized in that a cup shaped protective bushing (2) is provided for being introduced into the housing (1) of the measured value generator to be firmly connected thereto, and in that within the protective bushing (2) there are parailel guide recesses (3, 4) for the circuit plate (5) and in that the circuit plate (5) is secured within the protective bushing (2) by means of a casting compound (12).

2. Measured value generator according to Claim 1, characterized in that within the housing (1) there is a ring-shaped shoulder (16) in that the protective bushing (2) is provided with a ringshaped flanging surface (15) attributed to the ring-shaped shoulder (1 6), and in that for supporting the protective bushing (2) in its position defined by the ring-shaped shoulder (16) and the flanging surface (15) in the housing at the front face of the housing (1) there is provided a flanging off rim.

3. Measured value generator according to Claims 1 and 2, characterized in that between the housing (1) and the protecting bushing (2) there is a catching connection (24, 25).

4. Measured value generator according to Claims 1 to 3, characterized in that contacting projections (6 and 7), serving to transmit the measure value are contacted immediately on the circuit plate (5) and are partialy embedded within the casting compound (12) thereby forming the front facing end of the measured value generator.

5. Measured value generator according to Claims 1 to 4, characterized in that the measured value sensor (9) is arranged at one front face of the circuit plate (5).

6. Measured value generator substantially as described herein with reference to the accompanying drawings.