DE8815681U1 - Speed sensor - Google Patents

Description

K. 22236
25.11.1988 Sf/Pi

BOBEST BOSCH GMBH, 7000 Stuttgart 10 Speed sensor State of the art

The invention is based on a speed sensor according to the type of the main claim. In known speed sensors that work according to the inductive principle, the measuring sensor can be rotated in order to adapt the alignment of the connecting cable to the installation conditions. This is possible because the pole pin in the measuring sensor can be aligned independently of the electrical connection to the gear wheel whose speed is to be determined. The decisive factor here is the size and accuracy of the air gap during the rotational movement. On the other hand, if the speed sensors work with an element that is sensitive to magnetic fields, i.e. with a sensor element that is to be supplied electrically, such as a field plate or a Hall element, the element must always have a certain position in relation to the gear wheel. This means that the connection direction of the speed sensor itself and the connecting cable is fixed. If the speed sensor is to be installed in different objects, different housings are required. The possible uses of the speed sensor are therefore limited, or universal use is associated with high costs.

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I Advantages of the invention

; The speed sensor according to the invention with the characterizing features of the main claim has the advantage that it can be used in a uni-&iacgr; stranded manner. Both measuring sensors operating according to the inductive principle and magnetic field sensitive sensors can be installed in its housing. Even with magnetic field sensitive

t lent sensors, the speed sensor can always be in the optimal position for

·· rotating element, with the connecting cable connecting the respective

I V-J can be adapted to the respective installation conditions. A modular system can be constructed to meet the installation requirements of different

!' which can meet the needs of its customers.

I The measures listed in the subclaims provide

.- partial improvements and improvements of the main claim

; specified characteristics are possible.

drawing

An embodiment of the invention is shown in the drawing and explained in more detail in the following description. It

&bull; f\ Figure 1 shows a partial section through a speed sensor and ' Figure 2 shows a plan view of the speed sensor in direction A.

Description of the embodiment

In Figure 1, 10 denotes a speed sensor for measuring the speed of a wheel (not shown) of a motor vehicle. The speed sensor 10 is part of an anti-blocking system of the motor vehicle and interacts with a rotating gear ring 11 attached to the wheel, of which only a section with a few teeth 12 is shown. The speed sensor 10, shown in a partial longitudinal section, has a housing 13 made of plastic or metal.

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It has a fastening flange 14 with which it can be fastened to the motor vehicle. A magnetic field-sensitive element 15, such as a field plate or a Hall element, is arranged on the side facing the gear rim. The other end of the housing 13 has an opening 16 into which a wire part 17 is inserted. With the aid of the flange 14 formed on the inner wall of the housing 13, the wire part 17 can be fixed in any position in the housing 13. It is also possible, however, to fix the rotating part , in the housing 13 by ultrasonic welding (see below). The rotating part

17 has an elongated section 21 running perpendicular to the axis of the rotary sensor 10, in which a connecting cable 22 for the rotary sensor 10 is cast in plastic. The various wires 23 of the connecting cable 22 are connected by means of busbars

24 is connected to the magnetic field sensitive element 15. For this purpose, the ends of the busbars 24 facing the connecting cable 22 are designed as rings 25, which are shown in more detail in Figure 2. The rings 25 are arranged in planes parallel to the wires 23 of the connecting cable 22 and perpendicular to the busbars 24. Furthermore, the rings 25 have a different radius, whereby the radius of the busbar 24 closest to the inner wall of the housing 13 is the largest. This makes it possible for the respective

C further away from the inner wall busbars 24 through the ring

25 of the preceding busbar or busbars. The innermost busbar 24a does not need to have a ring, but it is sufficient to fold the end over to a plate 25a. Of course it is also possible to form the rings 25 or the plate 25a in a form other than the vertical arrangement.

The mounting flange 14 and the section 21 for the connecting cable 22 determine the installation of the speed sensor 10 on the motor vehicle. However, these installation options vary from motor vehicle to motor vehicle. Furthermore, the magnetic field-sensitive element 15 must always be installed with its sensitive side

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in the direction of the magnetic field. This design cannot be changed. With the help of the rotating part 17 and the rings 25 on the current rails 24, the alignment of the magnetic field-sensitive element 15 to the ring gear 11 can be optimally adjusted without having to change the existing mounting options. During assembly, the rotary sensor 10 is first attached to the motor vehicle using the fastening flange 14. The magnetic field-sensitive element 15 is then aligned with respect to the ring gear 11. With the help of the rotating part 17, the connecting cable 22 can now be aligned and installed in the remaining installation space. The rotating part 17 is clipped into the socket 18 in the housing 13 or ultrasonically welded. The wires 23 of the connecting cable 22 are soldered to the rings 25 of the current rails 24. Finally, the interior of the housing 13 is completely filled with plastic. Of course, this assembly can already be carried out in the factory and the finished rotary sensor can only be attached to the vehicle using the mounting flange 14.

The housing 13 can also be used particularly advantageously for a rotary sensor which works with the aid of a measuring sensor operating according to the inductive principle. As is known, the measuring sensor then consists of a coil body with an electrical winding attached to it, a pole piece arranged thereon and a permanent magnet, whereby the pole pin and the permanent magnet are in operative connection with the gear ring 11. In this case, no specific alignment of the pole pin relative to the teeth of the gear ring 11 is necessary if the pole pin is cylindrical. If it has a cutting edge, this must again be aligned perpendicular to the direction of travel of the gear ring.

The functionality of a speed sensor is conventionally known, so that it does not need to be discussed in more detail here.

Claims (9)

; &lgr;&iacgr; ' \ .' * &iacgr;&iacgr;&iacgr; ! III*«·« ti < · R. 22236 25.11.1988 Sf/Pi &Igr;&Ogr;&Bgr;&Egr;&Kgr;&Tgr; BOSCH GMBH/ 7000 Stuttgart 10 &bull; ' Claims 1. Rotary sensor (10) with a sensor opening on at least one side Housing (13), a measuring element (15), busbars (24) and a connecting cable (22), characterized in that the connecting cable (22) is fastened in a rotatable part (17) that can be replaced in the housing (13). 2. Rotary sensor according to claim 1, characterized in that the current rails (24) connecting the measuring element (15) to the connecting cable (22) are designed as rings (25) at their end facing the connecting cable (22). j 3. Rotary sensor according to claim 2, characterized in that the j Busbars (24) end at different levels. j 4. Rotary sensor according to one of claims 1 to 3, characterized in that &bull; characterized in that the rotatable part (17) is connected to the housing (13) by means of - is attached by ultrasonic welding. 5. Speed sensor according to one of claims 1 to 3, characterized in that the part (17) is fastened in the housing (13) by means of lugs (18). - 2 - B. 22236 6. Speed sensor according to one of claims 1 to 5, characterized in that the measuring element is a magnetic field sensitive element (15). 7. Speed sensor according to claim 6, characterized in that the element (15) is a Hall sensor. 8. Speed sensor according to one of claims 1 to 5, characterized in that the measuring element (15) consists of a coil body with an electrical winding attached thereto, a pole pin arranged therein and a permanent magnet and that the pole pin and the permanent magnet face a rotating body (11). 9. Speed sensor according to one of claims 1 to 8, characterized in that the housing (13) is filled with plastic. it *i I Has «II
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