Device for mounting a distance sensor on a motor vehicle

A device for mounting a distance sensor, in particular a proximity radar device, on a motor vehicle, the distance sensor being accommodated in a closed housing, the housing being moveably attached to a support and the support being attachable in an immoveable manner to the motor vehicle. The device is characterized in that the housing is attachable to the support by at least three screws arranged in an L-shape relative to each other, that the screws, in the installed state of the distance sensor, are able to be screwed from its front side, and that a screw-out protection is provided for at least two of the screws.

FIELD OF THE INVENTION
 The present invention relates to a device for mounting a distance sensor,
 in particular a proximity radar device, on a motor vehicle The device
 simultaneously permits simple shifting of the alignment (adjustment) of
 the distance sensor, for example, in relation to the longitudinal axis of
 the vehicle, free from operator error.
 BACKGROUND INFORMATION
 A device of this type is known from German Patent No. 42 01 214. This
 patent describes a device for adjusting a directional antenna of an
 anti-collision radar device of a motor vehicle, in which the alignment of
 the directional antenna is adjustable with the aid of an adjustment
 headlight. At the same time, a device is disclosed here for mounting the
 anti-collision radar device on the motor vehicle. In this device, the
 directional antenna of the anti-collision radar device is connected via a
 rotary axle to a vehicle-mounted housing. This design only permits
 adjustment of the directional antenna in the direction of height. The
 adjustment can be carried out with the assistance of an adjusting plate,
 both using adjusting screws and using a positioning motor. According to
 the patent, it is left to the discretion of one skilled in the art to
 provide a mounting support which would permit adjustability in two or even
 in all three directions. However, the patent gives no teaching of the kind
 which must be taken into consideration in such a mounting support with
 regard to cost-effective, large-scale production, easy applicability on
 other motor vehicles, as well as fast mounting and adjustment, free from
 operator error. Accordingly, the patent also gives no information about
 how a mounting support could look, in view of these additional
 requirements.
 From German Patent No. 196 42 810.6-53, which is not pre-published, it is
 known that the type of mounting support for a radar system, or at least of
 its directional antenna, can be adapted from the known suspension mount or
 support of a motor-vehicle headlight. In this context, the radar system or
 its directional antenna is fixed in position at three points, preferably
 in an L-shape relative to each other, in one plane vertical to the main
 beam direction. Thus, the two outer suspension mounts are displaced in two
 directions relative to each other. They are composed in each case of a
 threaded rod which is provided at one end with a ball pivot and is
 moveably supported by this in a mounting support. The middle, third
 suspension point is likewise moveably supported by a ball pivot, however,
 it generally has no adjustment possibility in the form of a threaded rod
 or something similar. The patent points out the problem that in each case,
 the adjustment device must be re-adapted to different installation
 surroundings. To that end, it suggests a radar system in which, to adjust
 the main beam direction, the position of the transmitter/receiver elements
 of the radar system is variable relative to a focusing means. However,
 such a radar system requires a design already basically suited to that,
 permitting, for example, adjustability of the transmitter/receiver
 elements within a housing of the distance sensor. The teaching of this
 patent cannot easily be transferred to a radar system already constructed
 per se, that does not include such adjustability. Furthermore, German
 Patent No. 196 42 810.6-35 does not disclose a device for mounting the
 distance sensor on the motor vehicle itself.
 Object, Achievement and Advantages of the Invention
 SUMMARY OF THE INVENTION
 The object of the present invention is to specify an alternative device for
 mounting a distance sensor on a motor vehicle.
 The advantage of the present invention compared to a radar system according
 to German Patent No. 196 42 810.6-35 is that the basic design of a
 distance sensor can remain unchanged within its housing. In this respect,
 the present invention requires no basic redesign of already existing
 distance sensors. Because the distance sensor is mounted on a motor
 vehicle by way of a separate holder, only a change of this holder is
 necessary for applying the distance sensor on other motor vehicles. The
 distance sensor itself can be used substantially unchanged for different
 types of motor vehicles. Thus, the combination of all the features of the
 invention ensure a simple adjustment and a simple application of the
 distance sensor on a motor vehicle. Compared to German Patent No. 42 01
 214, the mounting device according to the invention alone already has the
 advantage of permitting the distance sensor to be adjusted in the
 horizontal and in the vertical direction.
 The features that, in the installed state of the distance sensor, the
 screws are able to be screwed from its front side, and that screw-out
 protection is provided for at least two of the screws, permit adjustment
 which is easy and reliable, above all even with respect to operator
 errors. For example, without screw-out protection, it is impossible to
 rule out in a fail-safe manner that the distance sensor will not fall off
 from the motor vehicle during an adjustment operation because the screws
 have been unscrewed too far.

DETAILED DESCRIPTION
 FIG. 1, in a perspective representation, and FIGS. 2 through 4, in various
 side views, show a distance sensor 1 with a device according to the
 present invention for mounting on a motor vehicle. Distance sensor 1 is
 accommodated in a compact housing 3, which here is composed of a lower
 housing part 3b and an upper housing part 3a. The two housing parts 3a and
 3b are joined to each other by clip connections 6. Provided in upper
 housing part 3a is a lens 5 for focusing the utilized measuring beams of
 the distance sensor. (This described construction of distance sensor 1,
 especially the bipartition of the housing shown, is, however, independent
 of the present invention and can also be designed differently.
 Housing 3 of distance sensor 1 is secured to a support 2 by screws 9, 10,
 11. On its side facing away from distance sensor 1, support 2 has catching
 or locking elements 7 with which it snaps into correspondingly shaped
 accommodations on the body of a motor vehicle. In this exemplary
 embodiment, these catching elements 7 are provided on one longitudinal
 side and one transverse side of support 2. On its second transverse side,
 support 2 has a protuberance 8 which is provided with a bore hole 23 (FIG.
 4). As FIG. 2 shows, protuberance 8 forms a limit stop 12, with which
 protuberance 8 abuts against a corresponding body part of the motor
 vehicle.
 In addition to catch hooks 7, support 2 can be screwed to the body of the
 motor vehicle through bore hole 23 of protuberance 8. When applying the
 mounting device to different motor vehicles, catch hooks 7 and
 protuberance 8 can be redesigned, if applicable. They form, as it were, an
 adapter for various types of motor vehicles. Preferably, support 2 is
 always designed in the same manner on its side facing distance sensor 1.
 On this side, distance sensor 1 is screwed on using screws 9, 10, 11.
 Screws 9, 10, 11 engage in screw-in areas 13 of support 2. This is shown
 in FIG. 2, using screw 1I1 as an example, and ensures simple and fast
 assembly during large-scale production.
 As can also be seen from FIG. 2, screw 11, as well as the other screws 9,
 10, has a spherical screw head 14, which is supported in a correspondingly
 shaped accommodation 15 of housing 3. Accommodation 15 can also be
 produced as an independent accommodation element which is clipped into the
 housing of the distance sensor. Because of spherical screw head 14 and
 correspondingly shaped accommodation 15, housing 3 is moveable with
 respect to each of screws 9, 10, 11, and thus with respect to the entire
 support 2. As FIG. 4 shows, because of their L-shaped arrangement, screws
 9, 10, 1I form a three-point bearing arrangement. Screws 10 and 11 form
 two moveable bearings, and screw 9 forms a fixed bearing.
 For example, screwing screw 11 deeper into corresponding screw-in area 13
 causes the distance sensor to tilt with respect to support 2 about an axis
 which is formed through the suspension points of the distance sensor at
 screws 9 and 10. To permit this movement of housing 3, the screw heads
 have the spherical construction 14 already indicated. Unscrewing screw 11
 causes the distance sensor to tilt about the same axis in the reverse
 direction. Screwing screw 10 in and out causes distance sensor 1 to tilt
 with respect to support 2 in the orthogonal direction about an axis which
 runs through suspension points 9 and 11. Thus, the mounting device of the
 present invention offers the possibility of adjusting distance sensor 1 or
 its housing 3 in two directions that are vertical relative to each other.
 Nevertheless, distance sensor 1 is always securely connected to a body
 part of the motor vehicle via support 2.
 As an alternative to the exemplary embodiment described here, in which
 screw heads 14 are spherical, the screw ends could instead be supported
 spherically and moveably in a corresponding accommodation. In this case,
 the respective screw head must be securely joined to housing 3. On the
 other hand, however, the embodiment described here has the advantage that
 during an adjustment of the distance sensor, the screws themselves are not
 tilted at the same time, and therefore a moment of force or rotation, and
 thus also the effect of wear in the accommodation is less. In addition,
 the screw-out protection can thus be implemented in a simple manner at the
 screw end.
 Screws 9, 10, 11, are advantageously provided with self-cutting threads. In
 contrast, screw-in areas 13 are nearly or completely threadless before a
 screw is screwed in for the first time. This ensures that screwed-in
 screws 9, 10, 11, and thus distance sensor 1, are always joined to support
 2, free from play, even given large-scale production.
 Furthermore, the movement path of the distance sensor with respect to
 support 2 is restricted. For example, in the exemplary embodiment
 presented here, distance sensor 1 can be tilted in each direction by
 .+-.3.degree.. When screws 10 or 11 are screwed in, i.e. when housing 3 is
 tilted in the direction of support 2, the movement path is restricted by
 limit-stop locations 22 provided in the surface area of support 2. Thus,
 the adjustment possibility of distance sensor 1 relative to support 2 is
 also restricted in this direction.
 To prevent the distance sensor from falling off because screws 9,10, 11 are
 unscrewed too far, according to the present invention, provision is made
 for screw-out protections 4 for at least two of screws 9,10,11, in
 particular for screws 10 and 11. These screw-out protections 4 prevent
 screws 10, 11 from being able to be completely unscrewed from screw-in
 area 13 of support 2.
 FIG. 5 shows a preferred exemplary embodiment of screws 10 and 11.
 Spherical head 14 is visible. At the opposite end, the screw has a groove
 16 which has a hard limit stop 17.2 on the side facing the screw end, and
 on the side facing the screw head, has a gentle, i.e. less steep limit
 stop 17.1. FIGS. 6a and 6b show exemplary embodiments of possible
 screw-out protections 4. FIGS. 6a and 6b show a screw-out protection 18
 which has a cylindrical penetration, at whose end are arranged three
 catching elements 19 in the form of catch hooks. The screw according to
 FIG. 5 is guided through the cylindrical penetration of screw-out
 protection 18, until catch hooks 19 engage in groove 16. Due to hard limit
 stop 17.2 at the end of the screw, non-destructive unscrewing from
 screw-out protection 18 is no longer possible. However, because of gentle
 limit stop 17.1, it is possible to screw the screw in further at any time.
 In so doing, catch hooks 19 are spread in such a way that the screw passes
 through. Catch hooks 19, as well as the entire screw-out protection, is
 preferably manufactured as a plastic injection molded part, the elasticity
 of the plastic being so selected that catch hooks 19 are not broken off or
 bent over when screwing in a screw according to FIG. 5.
 FIG. 7 shows an alternative exemplary embodiment of screw-out protection
 20. Instead of axially arranged catching elements 19, it has two springs
 21 arranged radially with respect to the screwed-in screw. The functioning
 method of the springs corresponds to that in the specific embodiment
 according to FIGS. 6a and 6b.
 As an alternative to groove 16 described above, the screws can also be
 flattened in the shape of a plate at their end. This can be achieved, for
 example, by beating the screw ends flat with a stamper, so that they have
 a bulge-like enlargement at their end. Another possibility is in each case
 to clip a spring washer into the screw ends after they are screwed in. In
 both cases, the screw ends thus have an abruptly enlarged diameter which
 prevents the screw from completely screwing out of screw-in areas 13. An
 advantage of this alternative is that in this case, even catch hooks 19
 can be eliminated.
 It is particularly advantageous if support 2 is completely formed from
 plastic. On the one hand, this permits support 2 to be completely produced
 as a cost-effective, injection-molded part, and on the other hand, ensures
 that no corrosion problems can occur. Screw-out protections 4 shown are
 advantageously injection-molded at the same time with support 2.
 Another advantage of the exemplary embodiment shown here is that screws
 9,10, 11 are accessible and can be screwed from the front side of the
 distance sensor.