DE29819037U1 - Plate brake tester - Google Patents

Description

BOEHMERT & BOEHMERT

LAW FIRM

Boehmeit &. Boehmert · POB. IO 71 27 · D-28071 Bremen

German Patent Office Zweibrückenstr. 12

80297 Munich

DR-ING. KARLBOEHMERT,PA(1S99-I973) DIPL-ING. ALBERTBOEHMERT,PA(19O2.IW3) WILHELM J. H. STAHLBERG, RA. Bremen DR.-ING. WALTER HOORMANN. PA·. Branen DIPL-PHYS. DR. HEINZGODDAR.PA·.Manchen DR-ING. ROLAND LIESEGANG.PA·.Mönchen WOLF-DIETER KUNTZE RA. Bremen. Alicante D1PL.-PHYS. ROBERT MUNZHUBER, PA (1933-1992) DR. LUDWIG KOUKER. RA. Bremen DR. (CHEM.) ANDREAS WINKLER. PA·. Branai MICHAELA HUTH-DIERIG, RA. Mnnthen DIPL-PHYS. DR. MARION TONHARDT, PA·, Do**klorf DR. ANDREAS EBERT-WEIDENFELLER. RA, Bremen DIPL-ING. EVA LIESEGANG,PA·.Briin

PA - Patent Attorney

RA - Rechlsinusall/Altoniey Bl Lew

* · European Patent Attnnvy

All agreed to defend the EU measures. Alicante

Pro-leaional representation at the EV-Tradonark Otlke. Alicante

PROF. DR. WILHELM NORDEMANN, BA. B DR. AXEL NORDEMANN, RA. Potston DR. IAN BERND NORDEMANN, LLM, RA. Bertin DIPL.-PHYS. EDUARD BAUMANN, PA·. Hahnkiichen DR.-ING. GERALD KLOPSCH PA·. Düsseldorf DR. (CHEM.) HELGA KUTZENBERGER, PA·. Düsseldorf DIPL-ING. HANS W. GROENING,PA·.Month™ DR. ANKE SCHIERHOLZ, Attorney Potsdam DIPL-ING. DR. JAN TONNIES, PA. RA. Kiel DIPL.-PHYS. CHRISTIAN BIEHL, PA·. Kid DIPL.-PHYS. DR. DOROTHIE WEBER-BRULS. PA·. Fmrlfurt DR-ING. MATTHIAS PHILIPP,PA·.Bremen DIPL.-PHYS. DR. STEFAN SCHOHE. PA·. Munich MARTIN WIRTZ, LAWYER, Bremen DR. DETMAR SCHÄFER. Attorney at Law Bremen

DIPL.-CHEM. DR. ROLAND WEI3. Pa. Düsseldorf DIPL.-PHYS. DR.-ING. UWE MANASSE, PA, Bremen DR. CHRISTIAN CZYCHOWSKI, RA. Bertin CARL-RICHARD HAARMANN. RA. Munich

In Ziiwirranemrbcit tnnTtn ctwpendkm wnh

DIPL.-CHEM. DR. HANS ULRICH NUY. PA·. Munich

Your reference Your ref.

Your letter Your letter of

New registration (Gbm)

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Our ref.

A2986

Bremen,

23 October 1998

AHS-Prüftechnik AuH Schneider GmbH & Co. KG, Richtstrasse 32, 27753 Delmenhorst
Plate width test bench

The invention relates to a plate brake test stand for testing the brake(s) and/or the track and/or the chassis (in particular its vibration damper) of a motor vehicle, with at least two (brake) plates which are to be arranged essentially horizontally, parallel to one another and at a distance from one another (at right angles to the intended direction of travel), and which, in the fully assembled state, are to be driven over by the motor vehicle to be tested, are generally essentially rectangular, each of which is supported on a (possibly common) stationary abutment in the direction of travel (test direction) so that it can move horizontally (in general "floating") relative to the abutment and is supported either above ground (i.e. resting on the ground) or below ground, with their upper side in the latter case generally being essentially flush with the ground forming the driving plane, and with a force measuring device being arranged between each plate and the abutment, by means of which each

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Hollerallee .32 · D-28209 Bremen ■ P.O.B. IO 71 27 · D-28071 Bremen · Telephone+49-421-34090 · Fax+49-421-3491768

MUNICH - BREMEN - BERLIN - FRANKFURT - DÜSSELDORF - POTSDAM - BRANDENBURG - HÖHENKIRCHEN - KIEL - ALICANTE

e-mail: postmaster@boehmert.boehmert.de

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BOEHMEBL. & B*0EHMERT
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Forces (preferably electrical) applied to the plate in the direction of fall are to be measured and displayed using a Bremslcraft display device and/or recorded using a recording device and/or evaluated for further examinations of the motor vehicle in an appropriately programmed computer to which the corresponding signals are fed from the force measuring device.

Although nowadays, especially for carrying out brake tests in accordance with §§ 29, 41 StVZO, roller brake test benches are predominantly used, on which, with appropriate training, other vehicle tests such as a performance test can also be carried out, plate brake test benches of the type described above are still used - recently again to an increasing extent - for such vehicle tests on motor vehicles, since they offer considerable advantages over roller brake test benches due to structural measures, and the required electrical connection value and the energy costs to be expended also speak in favor of a plate brake test bench from an economic point of view with regard to the necessary investment expenditure and the operating costs.

Regardless of whether the (brake) plates are installed above or below the floor, the vehicle test is carried out in such a way that the vehicle is driven onto the (brake) plates at a predetermined speed, which is generally in the range of increased walking speed (approx. 5-10 km/h), and is braked by operating the brake pedal or the handbrake as soon as the wheels (or more precisely their tires) have safely reached the (brake) plate assigned to them (and have not yet left it again).

In a so-called two-plate brake test bench, the two wheels of one axle (e.g. the front axle) are tested first. Then, in a second braking process, the rear wheels are driven onto the two plates and braked.

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With a four-plate brake tester, all four wheels of a motor vehicle can be tested simultaneously, with the plates being designed and arranged in such a way that they each support one wheel of the motor vehicle when driving on the plate brake tester.

Since the wheelbase (i.e. the mutual distance between the two wheels on an axle), the wheel or tire width and also the axle distance between the front and rear axles as well as the wheel or tire diameter can vary from vehicle to vehicle, the dimensioning of the (brake) plates and their arrangement must take this into account, which is easily possible.

However, it is more difficult to test a motor vehicle in the intended manner. This is because this requires, first of all, that the vehicle is driven along the brake plate test stand in a substantially central position, i.e. straight (and not at an angle) and not significantly offset from the longitudinal center axis, but above all that the brake to be tested is actually and fairly precisely applied at the intended brake actuation point or in an adjacent (relatively short area), and all of this at a driving speed that is within the specified (relatively small) speed range of, for example, 5-10 km/h.

However, it has been shown that such a procedure, provided the above conditions are complied with, can be mastered after some practice by appropriate experts who are professionally involved in such vehicle inspections, i.e. employees of vehicle inspection centers (e.g. TÜV or DEKRA), or by vehicle mechanics in vehicle workshops who carry out such examinations during vehicle inspections.

Nevertheless, it would be extremely desirable and useful if laypeople who own a motor vehicle could also have a brake test carried out outside of the legally prescribed

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carry out the prescribed inspection in order to detect any defects and, if necessary, commission the necessary repair measures.

This applies in particular to relatively old vehicles, whose owners often do not have their vehicles inspected regularly and are reluctant to have their brakes checked at least from time to time for cost reasons. If such vehicles are driven over longer distances within the prescribed inspection intervals of two or three years, resulting in defects in the braking system, this is often the cause of accidents and therefore also represents a significant risk for third parties.

It would therefore be highly desirable if vehicle owners had the opportunity to carry out brake tests on their vehicles in self-service mode, as is now the norm when refuelling and washing vehicles, i.e. if - whether in the open air of vehicle repair shops or petrol stations, but also as part of an additional service offered by supermarkets or similar, or possibly completely separately - they could test their vehicle themselves on a suitable test bench, whereby the operational readiness could be brought about using the available payment devices, such as those used in multi-storey car parks or in paid parking lots. This idea has not been considered so far because it has been assumed that the known brake test benches cannot be used properly by laypeople.

The use of roller brake testers was ruled out from the outset because, among other things, they are quite complex and a vehicle test on a roller brake tester is even more complicated for laymen than on plate brake testers, but a brake test that is at least largely correct on a plate brake tester was also ruled out because it was assumed that the above-mentioned requirements

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for a proper brake test, which cannot be fulfilled by laypersons. In particular, such use has been ruled out from the outset because it is not particularly easy even for experts to apply the brakes precisely when the wheels to be tested have just reached the initial brake application point or have not yet left the permissible brake application area that follows it, and this while driving essentially in the middle of a straight line at a speed that is within a relatively small driving speed range and in such a way that the vehicle still comes to a standstill on the brake plates.

It was found, among other things, that even experts initially found significant differences in the braking forces determined during series of tests (e.g. around 20 measurements each) with the same vehicle, and that it was only after a certain period of familiarization for the expert driver that sufficiently accurate measurements (or more precisely, maximum values) for the braking forces were obtained. Since it was assumed that a layperson would need considerably more test measurements to achieve a reliable measurement - with the appropriate guidance from an operating manual - and this would be completely unacceptable from both an economic and other point of view, the idea of a significantly expanded use of brake test stands mentioned above has not yet been taken seriously, or has been immediately rejected.

The applicant for the present property right was not satisfied with this in itself unsatisfactory result and, as part of extensive series tests, first determined which of the above-mentioned requirements for a proper vehicle brake test on a plate brake test bench caused particular difficulties for laypeople, or whether this was the case with essentially the same frequency and intensity for all requirements.

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Surprisingly, it turned out that significantly more than 90% of all test subjects had no difficulty in driving a car essentially in the middle of a plate brake test stand and also driving along it essentially parallel to the intended direction of travel (test direction), whereby the percentage was even significantly higher when the driver was provided with suitable aids for driving straight and in the middle of the test track, for example an extension of the generally rectangular and longitudinally laid brake plate, painted or otherwise applied, at least on the driver's side of the vehicle, which acts as an auxiliary line or, in the truest sense of the word, as a guideline when driving along the brake test stand.

It also emerged that the majority of the test subjects had no great difficulty driving the test track (up to the start of the braking process) at a speed within the specified driving speed range (e.g. 5-10 km/h), as the drivers were able to orient themselves using the speedometer of the vehicle being tested, although the statistical proportion of those who had certain difficulties in doing so was significantly higher.

Finally, it was found that the average driver of a motor vehicle generally only managed, more or less by chance, to apply the brakes at the correct time (or more precisely, at the correct place or in the correct area) to ensure that the vehicle came to a stop while still on the brake pads.

The present invention is based on the task of improving the plate brake tester of the type described above while avoiding the disadvantages mentioned and others, in particular so that it can generally be used properly by laymen without great difficulty, so that they can use it after a short introduction by a qualified

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posted operating instructions, as is the case with car washes in petrol stations, for example, can generally carry out a proper brake test in accordance with the relevant regulations mentioned above on the first braking attempt, so that a plate brake tester can also be set up outside of vehicle testing stations, repair shops, etc. and can be used properly by laypeople, whereby the user fee can be relatively small, since a brake test does not have to be preceded by various test attempts.

The solution to this problem is characterized by an indicator device by means of which the driver of the vehicle to be tested is shown when driving onto the test bench that the wheels of the vehicle to be tested have reached the point (initial brake actuation point) or area in which the braking process must be initiated so that the vehicle comes to a standstill while still on the brake plates.

Such an indicator device can, for example, be a strip of a certain length formed on the route as an extension of at least one brake plate in the direction of travel, created by coloring, paving or the like, which initially gives the driver an orientation and driving aid to drive essentially straight ahead, namely in a relative position of his vehicle to the plate brake test stand that is central to the latter. If such a strip or the like has a finite length that is dimensioned such that the "strip" or the like on the ground is completely covered by the radiator of the vehicle so that it "disappears under the vehicle" for the driver, when the wheels to be tested have reached the specified initial brake confirmation point, then compliance with this operation can be largely guaranteed in this simple way.

However, such an indicator device is not yet optimal, since the viewing heights of drivers of different heights are different, and since it has been found that different people also adopt different sitting positions, and not

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only in terms of the relative position of the seat to the steering wheel, the position of which is now also often adjustable), but also in terms of the inclination of the upper body. This results in clearly different fields of vision, even if the operating instructions state that the driver must move the driver's seat to a certain position and lean back against the backrest when carrying out the brake test. Even then, there are still not insignificant differences in terms of the seating area, and an additional factor is that an unusual seating position that may be adopted leads to a stressful situation for many people or an increase in the stress that is already present, which often has an adverse effect on the entire brake test.

According to a preferred embodiment of the present invention, it is therefore provided that the indicator device is designed as a sensor device with at least one sensor, which is designed and arranged in such a way that it automatically triggers an activation signal when the wheels of the motor vehicle to be tested have reached the initial brake actuation point, whereby the activation signal can be used in different ways to trigger a timely (but also not too early) brake actuation.

For example, the sensor device intended as an indicator device can be connected to an alarm or indicator device (and possibly to the computer) which, upon receipt of the activation signal from the sensor, triggers an acoustic signal that can be perceived by the driver of the motor vehicle, so that the driver is prompted to immediately actuate the brake to be tested.

Alternatively or additionally, the sensor(s) of the sensor device can also trigger an optical signal, e.g. a light signal, or an initially green light signal is switched to a red signal after receiving an activation signal (or vice versa).

&Bgr;&Ogr;&Egr;&EEgr;&Mgr;&Egr;&&Tgr;·& BOEHMERT ""
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It has been shown that laymen carry out a brake test on a plate brake tester according to the invention correctly if they are aware from the outset - after studying the operating instructions displayed - that the time (or more precisely: the place) at which braking is to be initiated is automatically displayed to them, so that they initially only have to concentrate on driving the vehicle to be tested straight and essentially in the middle at a speed within the prescribed speed range into or onto the plate brake tester.

It has proven particularly useful and therefore preferable to design the sensor as a contact sensor, namely in the form of a contact threshold or similar, which is arranged at the initial brake actuation point of at least one plate, so that when the contact sensor (i.e. a contact threshold, for example) is passed over, the sensor automatically triggers an activation signal, for example for an acoustic or/and optical alarm or indicator.

According to another highly practical embodiment of the present invention, the sensor can also be designed as a contactless signal transmitter in the form of a light barrier or the like, which is arranged in such a way that it generates an activation signal when the wheels of the vehicle to be tested have reached the initial brake actuation point. A light barrier or the like can also be arranged in the area of the plate(s), namely, for example, slightly above the top of the plate at the initial brake actuation point, but possibly also considerably higher, namely, for example, so that the light barrier is penetrated by, for example, the bumper or another defined front section of the vehicle to be tested. Since the distance of, for example, the bumper or another front part of a vehicle to the wheels is different for different vehicle types, the sensor can be adjustable in terms of its height above the ground and/or in the direction of travel (test direction).

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Such an adjustment can be made manually (for example according to a table posted) with reference to appropriately specified adjustment points. However, in a further embodiment of the present invention, such a sensor can also be attached to a holding device that can be adjusted horizontally and/or vertically by means of a controllable adjustment device, whereby the control device of the adjustment device is connected to a computer that, after entering the type of vehicle (which can be done, for example, via a touch-screen panel), gives it the necessary control commands in order to adjust the sensor horizontally and/or vertically before the start of the brake test so that it generates an initial brake actuation signal when the wheels of the vehicle axle to be tested just reach the initial brake actuation point.

In particular for users who, even when an indicator device provided according to the invention is present, do not trust themselves (possibly rightly) to apply the brake in time and/or to not comply with the prescribed driving speed when entering the plate brake test stand, in a further embodiment of the present invention the brake(s) to be tested can be provided with a brake actuation device that can be actuated by a control device and that is to be actuated by means of an actuation signal supplied to the control device, whereby the sensor can also be expediently connected to the control device of the brake actuation device, and whereby a generated activation signal forms the actuation signal for the control device of the brake actuation device and thus ultimately an automatic actuation of the brake. As long as motor vehicles are not equipped with automatically actuated brake actuation devices, such a brake actuation device can be assigned to the plate brake test bench according to the invention as a mobile device, which can be detachably connected in a suitable, simple manner either to the brake pedal or the handbrake lever or the foot pedal for actuating the auxiliary brake (handbrake) so that automatic braking takes place when a corresponding signal is received. In this case, the driver only needs to drive at the prescribed speed essentially straight and in the middle of the

drive into the brake test station and do not even have to operate the brake, as this is done automatically when the initial brake actuation point is reached.

In order to ensure in any case that the brake test is not carried out at too low or too high a speed, a further embodiment of the plate brake tester according to the invention is characterized by a device for measuring the speed of the motor vehicle, which is connected to a/the computer and which generates an electrical signal reflecting the instantaneous speed of the motor vehicle, the arrangement being such that if the minimum or maximum speed required/prescribed for a proper brake test is exceeded or not met, no brake test is to be carried out, i.e. no activation signal is triggered by the sensor(s), and the display device, by means of which the braking result is immediately displayed during proper test operation, does not display, but preferably indicates that the driver has entered the brake tester at too high or too low a speed and must therefore repeat the brake test again, the circuit then of course being sensibly designed so that no fee is to be paid for this again, although the number of failed attempts can be limited so that a driver does not block the brake tester for a longer period of time due to proven incompetence. In such cases, it is expedient that a corresponding signal is sent to the installer or to a person appointed by him who is next to the brake tester (for example, if a plate brake tester according to the invention is installed in front of a petrol station, this would be to a petrol station attendant), so that in such cases an experienced specialist can carry out the brake test.

It is preferably provided that the device for measuring the motor vehicle speed is assigned a preferably adjustable setpoint generator which specifies the minimum motor vehicle speed and/or, if applicable, the maximum motor vehicle speed; that

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Furthermore, a difference generator connected to the setpoint generator is provided, which continuously compares the actual speed of the motor vehicle with the target speed and sends a difference signal to a/the computer, whereby the computer only sends an activation signal to the braking force display device if the actual speed is in the target range.

The force measuring device between a support plate and its stationary abutment can be designed in a variety of ways, for example in a conventional manner using strain gauges (DMS), by means of which the forces exerted by the plate(s) on the abutment are to be measured and preferably converted by the computer into braking forces, which are to be displayed by the braking force display device.

Preferably, the design is such that the braking forces of both wheels of a motor vehicle axle are added to form a total axle braking force, which can be displayed and/or recorded separately if necessary, whereby - in addition to a braking force display for the individual wheels - a registration or storage is preferably carried out and when the braking forces of the other two wheels are tested, their sum is preferably added to the sum of the braking forces of the two wheels tested first. Determining and comparing the sum of the braking forces with target values specified for the type has proven to be extremely useful in the course of development work, because the braking force differences between the front and rear axles are different for plate brake testers than for roller brake testers due to the dynamic axle load shift, so that a summation is required to determine the total braking force of a brake in accordance with the relevant regulations, which is obviously not disadvantageous in any way.

In order to accelerate the overall brake test even further, a plate-brake test bench according to the invention can be provided in a manner known per se with four (brake) plates each assigned to a wheel, which are each assigned in pairs to the wheels of a motor vehicle axle.

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of a motor vehicle to be tested, whereby the braking forces of all four wheels can then logically be added together to form a total braking force in a single test and - if necessary automatically using a corresponding computer program - compared with the prescribed values.

It should also be added that a simple type of indicator device can be a bead-like formation incorporated into a plate(s) at a right angle to the direction of travel (test direction), directed upwards or downwards above the plane of travel, which is arranged or formed shortly before the respective initial brake actuation point, as is known in a similar way from car washes, where a trough or a bead-like threshold indicates to the driver that he has reached the correct washing position.

Furthermore, when laying the plates above ground, it has proven to be extremely useful if ramp-shaped sections or parts are arranged at their front and/or rear end sections in order to enable effortless entry into the brake test stand.

Furthermore, it should be noted that the plates, which are preferably supported in and against the direction of travel via a force measuring device on the abutment assigned to them, are mounted by roller bearings, preferably in an encapsulated design, so that a correspondingly designed brake test stand is largely maintenance-free, especially if the force measuring devices are formed, for example, by strain gauges, which are known to work completely wear-free and whose operation is in no way impaired by exposure to precipitation water, snow, even salt water and oil.

Finally, it should be noted that by integrating devices for checking the shock absorbers or by integrating track testers into the plate brake tester according to the invention, an all-round check can be carried out to a large extent, whereby the results obtained can of course also be shown on a display if necessary and recorded in a test report, which is created by the computer after the test has been carried out and printed out by a printer. A brake test, particularly with a four-plate brake tester, usually only takes about 50 seconds, so that if necessary - for example in front of a supermarket - around 50-60 vehicles can be tested, and the user fee can therefore be kept correspondingly low.

The invention is explained in more detail below using an exemplary embodiment with reference to a schematic drawing in which, for the sake of simplicity, several different embodiments of the present invention are shown (schematically), even if these are generally not intended cumulatively but alternatively.

The drawing shows a plate brake test bench, designated as a whole with 1, for testing the brake(s), the track and the chassis of a motor vehicle (not shown for the sake of clarity).

The brake test bench 1 has four rectangular (brake) plates 2-2 laid horizontally in pairs parallel to each other and with a mutual distance a, of which the front pair of plates 2, 3 is assigned to the two wheels of the front axle of a motor vehicle to be tested, and the pair of plates 4, 5 to the two rear wheels. If the motor vehicle to be tested is driven onto the test bench in the direction of travel (= test direction) 6 and the front wheels are on the front pair of plates 2, 3, the rear wheels are also on the rear pair of plates 4, 5. The total length of the plates is therefore approx. 5 m with a plate width c of 55 cm.

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The plates 2-5 are laid below ground, but could also be arranged above ground. In this case, the rear sections 4' and 5 ^Λ of the plates 4 and 5 respectively would each be designed in the shape of a ramp, so that the wheels of the vehicle to be tested can be driven onto the plate arrangement without difficulty, without having to overcome a step in height.

In the present embodiment, the plates 2-5 are surrounded by a frame 7, which is set into the concrete floor 8 of a test room 9 flush with its top, which is attached to the building 10 of a petrol station. It should be noted, however, that the test bench 1 does not necessarily need to be housed in a closed housing (or even a roof), but can also be arranged outdoors if necessary, although at least a roof, as is usual for petrol pumps at petrol stations, is generally recommended because this protects the installed devices etc., which are described in more detail below, from the effects of the weather.

The width d of test room 9 is 3.7 m, while its length e is approximately 7 m.

A circumferential water channel 11 is formed between the frame 7, which is flush with the floor 8 of the test chamber 9, and the plates 2-5, which collects any water that may run off the plates 2-5 (or from the floor 8) and drains it into the sewer system via a water drain 12, so that the upper sides of the brake plates 2-5 that come into contact with the tires of the wheels of the motor vehicle to be tested are largely dry even when a vehicle exposed to precipitation drives into the test chamber 9 and rainwater or snow gets onto the floor or the brake plates 2-5. For this reason, the water channel 11 is laid with a gradient of 2% towards the water drain 12.

BOEHMERr&'BÖEHMERT*

The horizontally laid plates 2-5 are each mounted in a manner not shown in detail with encapsulated ball bearings, essentially "floating" and are each supported on their front side in the direction of travel 6 on the inlet frame 7 by means of a force measuring device 13, by means of which forces impressed on each plate 2-5 in the direction of travel 6 (or against the direction of travel 6) (in the present case by means of strain gauges) are to be electrically measured and displayed by means of a braking force display device 14, which is integrated in a desk 15 and arranged in such a way that it can be viewed from the motor vehicle to be tested. In addition, they are to be registered by means of a recording device 16 also integrated in the desk 15, both in the memory of a computer 17 also integrated in the desk 15 and on a recording chart which is ejected by the recording device 16 after the measurement has been completed.

The plate brake test bench 1 also has an indicator device consisting of two contact thresholds 19, a light display 20 and an acoustic alarm device 21, by means of which the driver of the motor vehicle to be tested is to be shown when driving onto the test bench 1 that the wheels of the motor vehicle to be tested have reached the initial brake actuation point 22 or the limited brake actuation range 23 beginning with this, in which the braking process is to be initiated by the driver so that the motor vehicle comes to a standstill on the plates 2-5 when braking. In the previously mentioned embodiment, the indicator device 18 is therefore designed as a sensor device that can be activated by touch with two sensors formed by the two contact thresholds 19, 19, which are arranged at the beginning of the two rear brake plates 2, 3, so that when the motor vehicle enters the test room 9 and thus when it drives onto the test bench 1, an activation signal is automatically triggered when the front wheels of the motor vehicle to be tested have reached the initial brake actuation point 22. The contact thresholds 19 are therefore electrically connected to the control and display panel 15, which, when the contact thresholds 19 are activated, on the one hand displays a light display in the high-mounted light display device 20 and on the other hand displays an acoustic signal.

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Alarm device 21 triggers an acoustic signal, whereupon the driver must operate the brake to be tested in order to carry out the brake test.

Instead of at least one contact threshold 19 or the like, the sensor could also be designed as a contactless signal generator in the form of a light barrier 24 or the like, which is arranged in such a way that it generates an activation signal when the wheels of the motor vehicle to be tested have reached the initial brake actuation point 22 or 23. The light barrier 24, shown as a thick dash-dotted line, can in principle also be arranged in the area of the plate plane, e.g. slightly above the top of the plate at the initial brake actuation point 22, but in the example additionally shown in the drawing, which is used as an alternative to touch sensors 19, it is arranged considerably higher at the upper end of one of two columns 24', the other column 24' having a reflector for the light barrier 24 in a manner known per se, at such a height that the bumper (or another part of the motor vehicle to be tested) passes through the light barrier when it enters the brake test stand 1, and when the light barrier 24 is broken, brake actuation signals are then triggered by the light display device 20 and alarm device 21.

Since both the bumper and other parts located at the front of a motor vehicle are designed differently from vehicle type to vehicle type and can have a different distance from the wheels, which in turn can also be designed differently from vehicle to vehicle, the light barrier 24 is arranged so that it can be adjusted in terms of its height above the ground 8 and in the direction of the vehicle 6, namely (like the reflector on the other column 24') it is attached to the one column 24' which acts as a holding device, which is arranged on the relevant column 24' so that it can be adjusted vertically and horizontally by means of a controllable adjustment device (not shown in detail), whereby the control device of the adjustment device is connected to the computer 17, which gives it the necessary control commands after entering the relevant motor vehicle type in order to

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on the one hand, the light barrier 24 and, on the other hand, the sensor assigned to it are to be set vertically and/or horizontally if necessary before the start of the brake test so that it generates an initial brake actuation signal when the front wheels have reached the initial brake actuation point 22.

Since the brake test is to be carried out at a vehicle speed of 5-10 km/h, and it is to be ensured that the driver notices if he has entered the test stand 1 too slowly or too quickly, a device for measuring the vehicle speed 25 connected to the computer 17 is also provided, which measures the instantaneous speed of the vehicle and generates an electrical signal corresponding to the instantaneous speed, which is transmitted from it to the computer 17 via a line 26, whereby the arrangement is such that if the minimum or maximum vehicle speed prescribed for the brake test is exceeded, no brake test is to be carried out or displayed, i.e. no activation signal is triggered by the sensors 19, 19 or 24.

The motor vehicle speed measuring device 25 is assigned an adjustable setpoint sensor which specifies the minimum and maximum speed of the motor vehicle at which a proper brake test can be carried out. This adjustable setpoint sensor is connected to the computer 17. In addition, a difference generator connected to the setpoint sensor - also not shown in detail in the drawing - is provided, which continuously compares the actual speed of the motor vehicle with the target speed and sends a difference signal to the computer 17, whereby the computer 17 only sends an activation signal to the indicator device 18 and the braking force display device 14 when the actual speed of the motor vehicle is in the target range.

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During a proper brake test, the control and display panel 15 displays the braking forces of all four wheels individually. In addition, the computer 17 adds together and displays the braking forces measured on each axle. Finally, the computer 17 also adds together and displays the braking forces measured on all four wheels separately, for reasons already mentioned above.

In a particularly simple and therefore inexpensive design of the brake test bench 1, its indicator device 18 - without an initial brake activation signal being automatically triggered - can be implemented in such a way that an indicator line or the like is formed in/on the route of the motor vehicle to be tested in its direction of travel 6, the length of which is so great that this indicator line disappears from the field of vision of the driver just when the wheels reach the initial brake activation area 23. Such a design is indicated in the drawing by a cross-hatched indicator strip 27 on the floor 8 of the test room 9, the width c of which is equal to the plate width, and which adjoins the brake plate 3 in the direction of travel 6. The indicator strip 27 is therefore in front of the driver in the line of sight when entering the brake test station 1 and also serves as a driving aid to ensure that the entry is straight and not offset to the side. The driver has learned from the operating instructions that he must operate the brake to be tested - at a vehicle speed within the specified speed range - when the indicator strip 27 disappears from his field of vision (until the vehicle comes to a standstill). Such a simple design is less reliable than an automatically operating indicator device because the driver's heights and seating positions are different, but it is often sufficient to ensure a proper brake test because the brake can still be operated within the initial brake operation range 23, so that certain tolerances can be compensated for. Such an indicator strip 27 can be implemented, for example, by coloring the floor 8 accordingly, tiling or the like.

BOEHMEKT& Bt)EHMERf
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A simple variant of the indicator device 18 with a similar result can be implemented in a bead-like or groove-like shape of the route immediately before the initial brake actuation area 23, which - similar to car washes - is designed in such a way that the driver can clearly perceive it as an unevenness in the ground, whereby the driver in this case receives the information from the operating instructions that he should/must actuate the brake to be tested immediately until the vehicle comes to a standstill, as soon as this (intentional) unevenness in the ground has been overcome.

It is readily apparent to the person skilled in the art that numerous further configurations for the plate brake test bench according to the invention are possible without departing from the scope of the invention and thus the scope of protection of the present property right.

In particular, it is readily apparent not only to experts, but also to laypeople that the plate brake tester according to the invention has created an opportunity to have brake tests carried out by vehicle owners who are generally not familiar with motor vehicles, whereby brake testers according to the invention can be set up and operated more or less anywhere, for example next to petrol stations, official vehicle testing stations, etc., but also in front of supermarkets, hotels, in or near public garages, etc., or even completely detached from neighboring establishments, sales outlets, etc., whereby authorization to use is granted in a similarly known manner by inserting coins or banknotes, whereby a receipt can also be issued, and particularly with training with relatively comfortable technical equipment, a brake test can be carried out by practically anyone without any effort and generally without any failed attempts.

Finally, it should be noted that in addition to a brake test, a track test can also be carried out on track test plates 28, and in particular a chassis test on the brake plates 2, 3, as well as using a light test device 29

BOEHMERTT&^ " " "

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if necessary, a light test. If a tracking test is required, a second indicator device 18 ^Λ can be provided, which ensures that the tracking test is carried out when the wheels in question are resting on the tracking test plates 28, but an adjustable indicator device 14, 24' can also be used for this, or the tracking test can be carried out automatically without a separate indicator device when the motor vehicle passes the tracking test plates 28.

a Plate spacing

b Total plate length

c Plate width

d Room width (of 9)

e Length (of 9)

• *

LIST OF REFERENCE SYMBOLS

1 Plate brake tester 2 (Brenns) plate 3 (Brake) plate 4 (Brenns) plate 5 (Brake) plate 6 Direction of travel (= test direction) 7 Frame (intake) 8th (Concrete) floor 9 Test room 10 Petrol station building 11 water channel 12 Water drainage 13 Force measuring device 14 Brake force indicator 15 Console (control and display) 16 Registration device 17 calculator 18, 18' Indicator device (=19-20) 19 Contact thresholds 20 Light indicator device 21 Alarm device

22 Initial brake application point 23 Brake operating range 24 Photoelectric barrier 25 Vehicle speed measuring device 26 Line 27 Indicator strips 28 Track test plates 29 Light test device

Claims (19)

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(Gbm) A2986 bdt with/in cooperation wilh DIPL-CHEM. DR. HANS ULRICH MAY.PA-.Munich Bremen, 23 October 1998 AHS-Prüftechnik AuH Schneider GmbH & Co. KG, Richtstrasse 32, 27753 Delmenhorst
Plate brake tester Expectations 1. Plate test bench (1) for testing the brake(s) and/or the track and/or the chassis of a motor vehicle, with at least two (brake) plates (2, 3; 4, 5) which are arranged essentially horizontally, parallel to one another and at a distance (a) from one another and are generally essentially rectangular, each of which is supported on a stationary abutment (7) - horizontally movable relative to it in the direction of travel (6), with a force measuring device (13) arranged between each plate (2 - 5) and the abutment (7), by means of which forces (preferably electrically) impressed on each plate (2 - 5) in the direction of travel (6) are to be measured and displayed by means of a braking force display device (14) and/or recorded by means of a recording device (16) and/or evaluated for further examinations of the motor vehicle in an appropriately programmed computer (17) are, the -5.61- Hollerallee 32 · D-28209 Bremen ■ P.O.B. 10 71 27 · D-28071 Bremen · Telephone+49-421-34090 · Fax+49-421-3491768 MUNICH - BREMEN - BERLIN - FRANKFURT - DÜSSELDORF - POTSDAM - BRANDENBURG - HÖHENKIRCHEN - KIEL - BIELEFELD - ALICANTE e-mail: postmaster@boehmert.boehmert.de BOEHMERT&'BOEHMERT ■ r -2- corresponding signals are fed from the force measuring device (13), characterized by an indicator device (18) by means of which the driver of the motor vehicle to be tested is shown when driving onto the test bench (1) that the wheels of the motor vehicle to be tested have reached the initial brake actuation point (22) or the brake actuation area (23) in which the braking process is to be initiated by the driver. 2. Brake test bench according to claim 1, characterized in that the indicator device (18) is designed as a sensor device with at least one sensor (19) which is designed and arranged in such a way that it automatically triggers an activation signal when the wheels of the motor vehicle to be tested have reached the initial brake actuation point (22). 3. Brake test bench according to claim 2, characterized in that the sensor (19) is connected to an indicator or alarm device (20, 21) and a/the computer (17) which, upon receipt of an activation signal from the sensor (19), triggers an acoustic signal which can be perceived by the driver of the motor vehicle. 4. Brake test bench according to claim 2 or 3, characterized in that the sensor (19) is connected to an indicator or alarm device (20, 21) and a/the computer (17) which on receipt of an activation signal from the sensor (19) triggers an optical signal perceivable by the driver of the motor vehicle. 5. Brake test bench according to one or more of claims 2 to 4, characterized in that the sensor is designed as a contact sensor in the form of at least one contact threshold (19) or the like, which is arranged at the initial brake actuation point (22) of at least one plate (2, 3). 6. Brake test bench according to one or more of claims 2 to 4, characterized in that the sensor is designed as a contactless signal transmitter in the form of a light barrier (24) or the like, which is arranged in such a way that it generates an activation signal when the wheels of the motor vehicle to be tested have reached the initial brake actuation point (22, 23). BOEHMERT&BOEHMER*f
-3- 7. Brake test bench according to claim 6, characterized in that the sensor (24) is adjustable with respect to its height above the ground (8) and/or in the direction of travel (6). 8. Brake test stand according to claim 7, characterized in that the sensor (24) is attached to a holding device (24') which can be adjusted or set horizontally and/or vertically by means of a controllable adjustment device, the control device of the adjustment device being connected to a/the computer (17) which - after input of the motor vehicle type - issues the necessary control commands to it in order to adjust the sensor (24) horizontally and/or vertically before the start of the brake test so that it generates an initial brake actuation signal when the wheels have reached the initial brake actuation point (22). 9. Brake test bench according to one or more of claims 2 to 4, characterized in that the brake(s) to be tested is (are) provided with a brake actuation device that can be actuated by a control device and that is to be actuated by means of an actuation signal supplied to the control device; and that the sensor (e.g. 19) is connected to the control device of the brake actuation device, an activation signal generated by it forming the actuation signal for the control device of the brake actuation device. 10. Brake test bench according to one or more of the preceding claims, characterized by a device (25) connected to a/the computer (17) for measuring the motor vehicle speed, which generates an electrical signal reflecting the instantaneous speed of the motor vehicle, the arrangement being such that if the minimum or maximum motor vehicle speed required/prescribed for the brake test is exceeded or not reached, no brake test is to be carried out, i.e. if necessary, no activation signal is triggered by the sensor(s) (e.g. 19). 11. Brake test bench according to claim 10, characterized in that the device (25) for measuring the motor vehicle speed is provided with a preferably adjustable setpoint generator BOEHMERT & BOEHMERt' " -4- is assigned, which specifies the minimum speed of the motor vehicle and/or, if applicable, the maximum speed of the motor vehicle; that a difference generator connected to the setpoint generator is provided, which continuously compares the actual speed of the motor vehicle with the setpoint speed and sends a difference signal to the computer (17), whereby the computer (17) only sends an activation signal to the indicator device (18) or the braking force display device (14) when the actual speed is in the setpoint range. 12. Brake test bench according to one or more of the preceding claims, characterized in that the force measuring device (13) has strain gauges as force meters, by means of which the forces exerted by the plate(s) (2 - 4) on the abutment (7) are to be measured and converted by the computer (17) into braking forces which are to be displayed by the braking force display device (14). 13. Brake test bench according to one or more of the preceding claims, characterized in that the braking forces of both wheels of a motor vehicle axle are added to form a total axle force which is optionally separately displayed and/or recorded. 14. Brake test bench with four plates, each assigned to a wheel of a motor vehicle to be tested, which are each assigned in pairs to the wheels of a motor vehicle axle, characterized in that the braking forces of all four wheels are added to form a total braking force which is optionally displayed and/or recorded separately. 15. Brake test bench according to claim 14, characterized in that the contact sensor(s) (19) is (are) arranged in the region of the front plates (2, 3). 16. Brake test bench according to claim 1, characterized in that the indicator device is designed as a bead-like formation perpendicular to the direction of travel (6) in at least one plate shortly before the respective initial brake actuation point (22 or 23), directed or projecting upwards or downwards over the roadway. -5- 17. Brake test stand according to one or more of the preceding claims, characterized in that the plates (2 - 5) are designed to be ramp-shaped at their front and/or rear end sections when laid above ground, or that a ramp-shaped section is arranged upstream or downstream of them. 18. Brake test stand according to one or more of the preceding claims, characterized in that the plates (2 - 5) are supported on the abutment (7) in and/or against the direction of travel (6) via the force measuring device (13). 19. Brake test bench according to one or more of the preceding claims, characterized in that the plates (2 - 5) are supported by or mounted in rolling bearings.