EP1552262A1

EP1552262A1 - Test stand for motor vehicles

Info

Publication number: EP1552262A1
Application number: EP03776799A
Authority: EP
Inventors: Hermann Wimmer
Original assignee: Femboeck Automotive GmbH
Current assignee: Femboeck Automotive GmbH
Priority date: 2002-10-18
Filing date: 2003-10-16
Publication date: 2005-07-13
Also published as: US7392693B2; AU2003286096A1; WO2004038355A1; JP4616769B2; JP2006503311A; DE20320215U1; US20060123896A1

Abstract

The invention relates to a test stand for motor vehicles, said test stand comprising a rolling device (1) which has a bearing surface (3) and is used to roll the wheels (2). Said bearing surface (3) is rotatably driven and can preferably be blocked and/or braked and/or released. Said test stand is designed and developed, in terms of an especially significant functional test, such that the rolling device (1) is mounted in such a way that it can be at least slightly displaced with at least two degrees of freedom, and in order to determine the force generated by the motor vehicle during driving and/or braking movements of the motor vehicle, the force acting between the rolling device (1) and a pre-determinable fixed point (10), and/or the displacement path and/or angle of rotation created between the rolling device (1) and a pre-determinable fixed point (10) during driving and/or braking movements of the motor vehicle, can be measured.

Description

"Test bench for motor vehicles"

The present invention relates to a test bench for motor vehicles, with a rolling device having a tread for rolling the wheels, the tread being driven in rotation and preferably being lockable and / or braked and / or unlockable.

Test benches of the generic type have long been known in practice. They are used in motor vehicle repair workshops and also at the TÜV as part of the periodic suitability test of motor vehicles. The functionality or effectiveness of the brakes is usually checked there.

In the prior art known from practice, there are basically three different methods for testing motor vehicle brakes. So far, testing has been carried out with very special equipment, namely with test plates, test rolls or using a decelerator. When testing using test plates and using a decelerator, one speaks of a dynamic test. When using test rolls, one speaks of a static test. The difference between the dynamic test and the static test is that when testing with test plates or with a decelerator, the vehicle must be moved. The test plates and the decelerator are fixed. On the other hand, when testing using test rollers, the vehicle stands still and the test rollers rotate. The preceding explanations make the main difference between the two basic test methods clear.

In the case of a plate brake test stand, a partial section of a road is simulated with the test plate, the test plate being mounted on rollers. The vehicle travels over the test plate, which is connected to the environment in the direction of travel via a measuring element, for example with a drive-on plate. If the vehicle is braked on the test plate, the braking forces that occur during braking are recorded via the measuring element. The measuring process only takes as long how the vehicle is on the limited test plate. In practice, the measurement time is between 0.5 and 1 second.

The faster the test plate is driven onto, the greater the braking forces absorbed. However, a maximum braking force that can be absorbed cannot be higher than the friction between the tire and the test plate, since otherwise the slip limit is exceeded. In any case, it is disadvantageous with the plate brake test bench that the measurement result is dependent on the approach speed. In addition, the measurement can only be carried out over a very small time segment, since the length of the brake plate is limited. Ultimately, the plate brake tester is not very practical, since it is not only extremely difficult for a layperson to be precise, i.e. exactly when driving on the test plate to start the braking maneuver.

Due to its design, the roller brake tester is nothing more than an infinitely long road, which is simulated by rotating rollers. The braking process can thus be tested over any period of time.

The operation of the roller brake tester results from its design. The vehicle slowly moves into the roller set - usually two rollers - via a test stand frame until it comes to a standstill on the test rollers. The test rolls are driven by an electric motor, usually via chains. The electric motor is usually oscillating. If the wheel is braked, the electric motor has to use more force to turn the wheel. This force is absorbed by a sensor, which is usually designed as a torque arm.

The roller brake tester known from practice is a static system in which the vehicle is stationary. The rollers can be rotated for any length of time so that the vehicle's braking system can be tested in almost any condition. In contrast to the plate test bench, the test is by no means limited in time and each driving state - depending on the drive of the test rollers - can be repeated as often as required. However, the brake can - similar to the Plate brake test bench - do not test beyond the adhesion value of the roller surface, as the slip limit will be exceeded.

With a conventional roller brake tester, however, it is disadvantageous that the tires run directly on two rollers and are pressed or rolled by the rollers. This falsifies the test result due to different static friction of the respective situations, namely depending on the weight, so that the roller brake tester appears disadvantageous in this respect.

It is also known from practice to determine the checking of the braking effect of a vehicle using braking deceleration measuring devices. Ultimately, a decelerator works with an accelerated mass or weight, which is mounted on rollers and connected to a frame via a spring. When measuring, the measuring device lies horizontally in the direction of movement. When braking, the weight - here the motor vehicle - is deflected in the direction of travel. The path is measured and converted into a delay. An acceleration sensor that works on the same basic principle can also be used for this purpose. If braking deceleration occurs, the same forces act as the weight of the test specimen itself.

The deceleration measuring device is problematic in practice, since it can only determine the total deceleration of the vehicle, but not the braking force distribution on the individual wheels. As a result, this type of test is only used in exceptional cases, namely only regularly if, due to technical circumstances, a vehicle cannot be tested according to the two methods above.

Ultimately, in test stands known from the prior art, the functional tests of vehicle components are carried out with a test device suitable for the respective test. Rotary drives or brakes are preferably used to record braking force and power. Either track test plates or wheel aligners are used to record track values. Shock absorbers are tested with shock absorber testers and joint play is tested via pneumatically or hydraulically driven test plates. Checking the Individual parameters are carried out sequentially by moving the vehicle from test device to test device or by moving the test device to the vehicle as required. In only a few exceptions, a combination device is offered, which, however, is coupled to the wheel via test rollers. This is not in conformity with the road and significantly falsifies the actual wheel standing forces that occur on the road.

A test stand is also known, for example, from US Pat. No. 1,957,455, the wheel for testing being in a type of “shell”. This increases the wheel contact area, which no longer corresponds to the state on the road.

The present invention is based on the object of specifying a test bench of the type mentioned at the beginning, in which a particularly meaningful functional test can be implemented using structurally simple means.

According to the invention, the above object is achieved by a test bench with the features of patent claim 1. According to this, the test stand of the type mentioned at the outset is designed and developed in such a way that the rolling device is at least slightly movable with at least two degrees of freedom and that in order to determine the force generated by the motor vehicle during driving and / or braking movements of the motor vehicle, the force between the rolling device and a force that can be predetermined and / or the displacement path and / or angle of rotation that occurs during driving and / or braking movements of the motor vehicle between the rolling device and a predetermined fixed point can be measured.

According to the invention, it has been recognized that it is entirely possible to implement a single test bench in which several different parameters can be detected in the course of a single measurement process. For this purpose, the rolling device is at least slightly movable with at least two degrees of freedom. Thus, for example, not only forces occurring in the direction of travel - for example during brake tests - but also, for example, transverse forces - lateral forces - can be detected and documented. More precisely, to determine the force generated by the motor vehicle during driving and / or braking movements of the motor vehicle, the force between the rolling device and force acting at a predeterminable fixed point can be measured. As an alternative or in addition to this, the displacement path and / or angle of rotation that occurs during driving and / or braking movements of the motor vehicle can also be measured between the rolling device and a predeterminable fixed point. In other words, forces acting in different directions and / or displacement paths and / or occurring angles of rotation can be measured between the rolling device and a predeterminable fixed point.

Ultimately, this makes it possible to record all the forces generated by the vehicle at the same time or with a time delay in a three-dimensional profile, this being possible when the vehicle is arranged on a single test bench. The requirement is taken into account that each vehicle has a different construction of the chassis, brakes, drive and tires. Since the wheel above the tire represents the last point on the vehicle towards the road, the sum of all forces that arise when rolling off occur at this point. This can be compared to the actual situation on the street. The road is simulated or simulated by the endless running surface.

The test stand according to the invention is a test stand with a rotationally driven tread and thus a test stand that works statically, in which the motor vehicle is stationary and the running surface of the rolling device is a quasi endless road. The rolling device is in itself a compact unit that is at least slightly movable with at least two degrees of freedom. Any force transducer can be used to determine the force generated by the motor vehicle during driving and / or braking movements of the motor vehicle. The rolling device therefore functions similarly to a roller test bench, on which the wheels of the vehicle are positioned. The disadvantages of the conventional roller test bench are eliminated insofar as the functionality of the plate test bench is realized in that the unwinding device is designed as a specially mounted unit, namely similar to the test plate on the plate test bench. This is because the unwinding device can be moved at least slightly overall with at least two degrees of freedom. A measuring device acts between the rolling device and the predeterminable fixed point Force determination and / or determination of the displacement path and / or angle of rotation that occurs.

Consequently, the test stand for motor vehicles according to the invention realizes a test stand in which a particularly meaningful and versatile functional test is carried out using structurally simple means.

In a specific configuration of the test bench, a degree of freedom could correspond to a movement transverse or perpendicular to the direction of travel in a horizontal direction, in particular along an X axis. A lateral force can be detected. The inclination of the wheel to the direction of travel - the lane - is shown in this direction. Depending on the setting - with toe-in or toe-out - a force that is negative or positive to the direction of travel is exerted. Here, the tread and / or the rolling device is shifted accordingly in the X direction. A track measurement could now be carried out in such a way that a displacement path and / or the force is measured until the tread and / or the rolling device has shifted to such an extent that the measured force is 0. As an alternative to this, the tread and / or the rolling device for tracking measurement could be shifted until no more force acts on the tread and / or the rolling device. In other words, the force is then 0. When the displacement path is measured in this direction, a lateral drift of the vehicle can be determined.

Another degree of freedom could correspond to a movement along the direction of travel, in particular along a Y axis. The force in or against the direction of travel can be measured in this direction. The force in the direction of travel corresponds to a braking force, the force against the direction of travel corresponds to the acceleration.

A further degree of freedom could correspond to a movement transverse or perpendicular to the direction of travel in a vertical direction, in particular along a Z axis. The weight of the wheel or the motor vehicle could be measured and a shock absorber test could be carried out. A further advantageous degree of freedom could correspond to a rotation about a preferably vertical axis, in particular a Z axis. A measurement of the angle of rotation could provide an indication of the vehicle's lane setting.

In a particularly advantageous embodiment, the entire test stand could be rotatable about a preferably vertical axis, in particular a Z axis. This could simulate cornering, for example. Any angular position to the direction of travel could be set or controlled. With such a function, a joint play tester and / or a wheel bearing tester could be implemented.

The compactly implementable rolling device could be stored in a lifting platform in a particularly practical and simple manner. With regard to the highest possible mobility, the rolling device could also be stored in a vehicle. This would allow the unwinding device to be brought to any location.

In a further advantageous embodiment, the rolling device could be mounted in a vibrating or vibrating device. This could simulate bumps in a road and possibly perform a shock absorber test.

As an alternative or in addition to the fact that the entire test stand can be rotated about any axis, the rolling device itself could be mounted in a rotating device and thus be rotatable, in order to carry out joint play or wheel bearing tests if necessary.

In the context of a particularly advantageous embodiment, in particular with regard to any retrofitting of workshops, TÜV test facilities or the like, the rolling device could be mounted in a frame which can be fixed on or in the floor or on a wall, so that the rolling device can be handled together with the frame is. Such a rolling device with a permanently assigned frame could be positioned as desired on the floor of a workshop and could be positioned and fixed against a fixed point - against the floor or against a wall - with the interposition of a suitable measuring device. So lets the test stand according to the invention can be used variably, for example with a height of 50 mm, it only being necessary to ensure that it can be supported on the floor, against a wall or the like. With a small design, it is also easily possible to provide a corresponding recess in the floor and to integrate part or all of the frame in the floor.

Furthermore, it is also possible to store the entire test stand or the unrolling device with the frame within a floor recess, namely to place it on a roller bearing, for example, and to arrange a corresponding measuring device between the frame and the wall of the floor recess for recording measured values. Complete integration into the floor is guaranteed with the best possible storage and displacement of the entire frame.

If the unrolling device or the test stand is articulated on a wall, the articulation could be carried out by means of a coupling element, preferably by means of a metal part. The coupling element could be integrally formed with the frame in a particularly simple manner.

The coupling element and / or the frame could or could have at least one weakening at at least one predeterminable point, so that bends and / or torsions can be detected, preferably via at least one sensor assigned to the coupling element.

The weakening or weakenings could or could be formed by recesses and / or millings in a structurally particularly simple manner. At least one force transducer and / or at least one sensor for bends and / or torsions could be arranged in the weakening or weakenings in a particularly simple manner in terms of measurement technology. Strain gauges could be used as force transducers or sensors. Any force transducers or sensors could move through the recesses, millings or receptacles under load. For example, horizontal and vertical braking forces can be measured. In the case of particularly meaningful measurements, a separate rolling device could be provided for each wheel of an axle. Each of the two rolling devices could be assigned to a separate frame. Thus, two separate rolling devices with corresponding frames could be provided for both wheels of an axle, wherein these two rolling devices can be arranged together with their frames on the floor or in the floor. A variable use is given. As an alternative embodiment, both unrolling devices could be assigned to a common frame. Such a configuration is particularly useful for stationary test benches. In the case of mobile test stands, the separate handling of two frames with unrolling devices arranged therein is cheaper.

In the context of a very particularly advantageous embodiment, in particular to avoid deformation or rolling of the wheel during the actual test, the unrolling device could comprise at least two rollers or rollers, wherein a treadmill designed as an endless belt and forming the tread could run around the rollers or rollers. With the help of such a treadmill, a road can be imitated ideally, so that the behavior of the motor vehicle can be tested over an endless road. To simulate a more or less smooth road surface, it is of further advantage if the unrolling device comprises three or more rollers or rollers, so that unevenness is essentially avoided.

It has already been mentioned before that the rollers or rollers are preferably arranged in a frame. In a further advantageous manner, the rollers or rollers are mounted laterally in the frame and are arranged in such a way that they run floor-free within the frame. It is also possible to mount the entire arrangement of the rolling device with its frame again on rollers or rollers in order to ensure its safe displacement, for example within a floor recess - against a measuring device. For this purpose, the rollers or rollers - on the side in the frame - can be guided in roller bearings. The implementation of a sliding guide is also conceivable and particularly simple in terms of construction. In order to provide a particularly flat running surface, the rolling device could be assigned a sliding device, preferably a sliding plate. A treadmill forming the tread could slide on the sliding device. As an alternative to a sliding device, a roller or roller arrangement could be provided, on which a treadmill forming the tread could run. A roller or roller arrangement is particularly suitable at higher running speeds, since there is a risk of excessive heat being generated when using a sliding device. The sliding device could also be formed by individual slats below the tread.

The tread could have a lateral force absorption for intercepting or absorbing the laterally acting forces or lateral forces. Such a lateral force absorption could preferably be formed by a belt or a flexible rib which is assigned to the tread. Alternatively or in addition to this, a roller or roller and / or a sliding device or a roller or roller arrangement for absorbing lateral forces could have a guide device. Such a guide device could be formed by a groove in the last-mentioned components. With regard to a particularly safe interception of the lateral forces, the lateral force absorption of the tread and the lateral force absorption of the roller or roller and / or sliding device or roller or roller arrangement could be complementary to one another. In other words, a belt or a flexible rib of the tread could be guided in a corresponding groove in the roller, roller, sliding device or roller or roller arrangement.

With regard to a structurally particularly simple configuration, the rolling device could be guided in the sense of an XY slide or XYZ slide. Such a tour could take place in a framework. The rolling device could form an independent functional module. In this sense, a drive module could be an independent functional module and can preferably be placed on the unrolling device in different ways or can be coupled to the unrolling device.

The test bench according to the invention works in a similar way to the conventional roller test bench. As a result, the vehicle is required to use the each wheel to be tested runs on the unrolling device, after which it is driven. Although the motor vehicle stops on the spot, the wheels are rotated, thereby simulating an acceleration of the vehicle. For safety reasons, in particular so that the wheel is not pushed or pushed backwards by the unwinding device when braking, in the context of a very particularly advantageous embodiment, viewed in the direction of travel, a free-running is in front of the first roller or roller, i.e. behind the wheel on the unrolling device Support roller arranged against which the wheel can be supported when braking. This ensures safe positioning of the wheel on the test bench.

As an alternative or in addition to this, a free-running support roller, against which the wheel is supported when accelerating, could be arranged behind the last roller or roller, that is to say in front of the wheel on the unrolling device. This could ensure safe positioning of the wheel on the test bench during acceleration.

In concrete terms, the support roller could be held elastically and / or spring-loaded in the support position via side support arms. The support roller could be held in the support position via the side support arms in such a way that it can be lowered from the tire in the direction of travel while overcoming the elastic force or spring force and can be erected automatically into the support position after being run over. The support roller or the support arms are locked against the direction of travel and cannot be pressed down from the support position. Since the support roller is rotatably mounted, it offers a suitable abutment for the rotating wheel when braking or accelerating.

It is also conceivable that the support roller can be driven over in a lowered state. As soon as the wheel is positioned on the unrolling device, the support roller could be actuated so that it moves up into the support position and is preferably locked there. In general, the support roller could be movable into the support position when the wheel is positioned on the unrolling device. The support roller and the support arms carrying the support roller could have a very special mechanism, preferably a worm drive, with which the support roller can be removed from the lowered position can be brought into the support position. However, other mechanical designs and drives are also conceivable.

It has already been stated beforehand that the force acting, for example, during braking between the rolling device and a predeterminable fixed point can be measured. If the roll-off device is arranged within a frame and if the frame limits the roll-off device or the test stand as a whole, the force absorption and / or the measurement of the displacement path and / or the angle of rotation between the rolls or rollers and the Frame. For this it is necessary that the rollers or rollers are arranged to be at least slightly movable within the frame with the interposition of a measuring device. In any case, the force absorption and / or the measurement of the displacement path and / or the angle of rotation can be carried out at any point between the rollers or rollers and the frame, wherein the rollers must be able to be displaced and / or rotated within the frame.

In a particularly compact embodiment, the force absorption and / or the measurement of the displacement path and / or the angle of rotation could take place in or on the bearings and / or within the rollers or rollers.

With regard to a safe drive of the unrolling device, at least one roller or roller could be designed as a non-positive drive roller or roller. In other words, the roller would be driven in rotation. The other roller or roller or rollers or rollers could or could be designed as a non-positive deflection roller or roller. This would result in a rotary drive via the tread or the treadmill. The roller or roller could be freely rotatable.

To drive at least one of the rollers or rollers, at least one motor, preferably an electric motor, could be provided, which engages the one or more rollers or rollers by means of a chain, drive belt or the like. Gasoline or gas engines are also suitable as engines. Ultimately, any engine is conceivable. Even a magnetic drive could be implemented. Any motor could be decoupled to drive the belt or the tread, so that an idle is possible.

The motor could be arranged in a particularly compact manner in the area between the rollers or rollers. Depending on the requirements, the motor could also be arranged in the area under the rollers or rollers. Even an arrangement of the motor in one of the driven rollers or rollers or in the driven rollers or rollers is possible for realizing a compact configuration of the test bench. The motor could be an integral part of the roller or roller.

In particular in the context of a particularly flat configuration of the test bench, the motor could be arranged in one of the driven rollers or rollers. In this respect, the roller or roller as part of the engine could be driven directly and without further losses as a direct drive without a gear.

To avoid icing of the tread, the rolling device could be assigned a heating device for the tread. This enables the test bench to be used at low temperatures.

With regard to a safe running of the tread, the rolling device could have a tensioning device for tensioning the tread. Such a tensioning device could have at least one spring acting between two rollers or rollers. In this case, one roller or roller or a plurality of rollers or rollers could be provided, which are displaceable for tensioning, so that the running surface or the belt can be tensioned over the rollers or rollers. A tensioning device could work automatically so that the running surface or the belt is always suitably pre-tensioned.

The tread or the treadmill could be removable from at least one side of the rolling device. This enables the replacement of worn tape and / or the use of differently designed treads or tapes for different conditions of use. In particular, the surface of the tread could have a grain size with a predeterminable grain size. In this way, different road surfaces can be simulated Emery belt can be used as a tread, which is known from belt grinders.

In a further embodiment, the surface of the tread could have a rubber covering of a predeterminable thickness. For example, wheels that have tires with spikes could be tested. The rubber pad could prevent the tread from being destroyed quickly.

With regard to commercial use, the surface of the tread could have preferably printed image and / or text information. This could result in advertising.

With regard to a particularly stable tread, the tread could be designed as a treadmill, preferably as a fabric belt. This ensures permanent operation of the test bench.

In a further advantageous embodiment, the rolling device could be assigned a receiver for sound waves, preferably a microphone. In this case, rolling noises could be detected in order to carry out a tire test with regard to smooth running. For example, you can determine whether tire treads are flaking. This allows the track or the setting of the track to be checked. Unbalances can also be determined via the rolling noise, such unbalances being able to be determined based on detectable weight fluctuations.

A V-belt could be assigned to the tread or treadmill, which is preferably glued to the tread or treadmill. Such a V-belt could run in a groove in the drive, which would ensure a safe drive.

In a further advantageous manner, the rolling device could have several, preferably cascaded, running surfaces. This would result in a particularly large running surface. In a further embodiment, the test stand could have a brake, so that braking of the rolling device is made possible. An eddy current brake could be used here. This would allow the test bench to be designed as a dynamometer.

The test stand according to the invention could advantageously be used as a road simulator, and a wide variety of road configurations can be implemented.

In practice, it has been shown that the motor vehicle to be examined and in particular the front wheels in some cases do not remain arranged or positioned stably on the rolling device or the tread when a test or measurement is carried out. More specifically, the motor vehicle can sometimes slip off the test bench or the unrolling device. In this regard, the roll-off device could have a device for setting a negative track, which virtually enables centering or predeterminable positioning of the motor vehicle on the roll-off device or the tread. This achieves a particularly high degree of positioning stability with respect to the motor vehicle on the test bench or the unrolling device.

The test bench according to the invention can be used in particular for wheel alignment. Furthermore, the resulting static and dynamic weight force can be measured due to the vertically movable bearing for determining the weight gain or weight loss when standing and turning the wheel.

Ultimately, the invention comprises the arrangement of additional systems under the unrolling device, which allow the unwinding device as a whole to oscillate and / or to rotate the unwinding device as a whole or to pivot it vertically. Ultimately, the running surface is mounted in such a way that the forces or the path along each movement axis can be measured using appropriate measuring devices. The rollers of the unrolling device could move sideways or the entire frame could move sideways. This enables the track or an axis camber to be determined.

With the test stand according to the invention, a large number of functional elements relating to the chassis and drive of a motor vehicle can be tested. The engine, the gearbox, the wheel suspension, wheels, tires, brakes, shock absorbers, track, joints, steering and much more are mentioned as examples. In addition, the many universal installation options of the test bench are convincing, both above floor, under floor, in lifting platforms and even on vehicles. The special design of the test bench allows individual functional tests, as they are known from current test devices. In addition, all tests can be activated essentially at the same time, so that there is still a universal test option that is still unknown.

With the test bench it is possible, for example, to measure the rolling resistance without external influences, for example by bearings or gear friction in the drive and brake branches.

To simulate cornering and for special measurement programs, the entire test bench can be placed on a rotating device which can be controlled by a motor drive in any angular position to the direction of travel.

The test stand according to the invention can be easily retrofitted in all existing pits in a workshop. This makes it possible to implement a test lane with, for example, a track test, brake test and shock absorber test. Wheel alignment and weight measurement can be carried out in a simple manner.

There are now various possibilities for advantageously designing and developing the teaching of the present invention. For this purpose, on the one hand, reference is made to the claims subordinate to claim 1 and, on the other hand, to the following explanation of exemplary embodiments of the invention with reference to the drawing. In connection with the explanation of the preferred embodiments of the invention with reference to the drawing, in general preferred refinements and developments of teaching explained. Show in the drawing

1 is a schematic side view of an embodiment of a test stand according to the invention with the wheel in the test position,

Fig. 2 in a schematic plan view of the possible degrees of freedom of

Test bench with an exemplary force transducer and / or sensor arrangement,

3 is a schematic detailed view of the rolling device of the test bench with a slide plate insert,

4 is a schematic top view of the rolling device from FIG. 3,

Fig. 5 in a schematic side view of the rolling device with a

Castor Insert,

6 is a schematic plan view of the rolling device from FIG. 5,

7 shows a schematic front view of the test bench from FIG. 1 in an underfloor installation,

8 shows a schematic front view of a further exemplary embodiment of the test bench according to the invention with an above-ground arrangement,

Fig. 9 is a schematic plan view and front view of the rolling device with an embodiment as an XY slide with ball bearings and

Fig. 10 is a schematic side view of the rolling device with an extended support roller. 1 shows a schematic side view of a test bench for motor vehicles which, as an essential component, comprises a rolling device 1 for rolling the wheels 2. The rolling device 1 forms a running surface 3 for the wheel 2. The running surface 3 is driven in rotation and preferably can be blocked and / or braked and / or activated. The preferred direction of rotation of the rolling device 1 and more precisely its tread 3 is indicated by an arrow 4. The preferred direction of rotation of the wheel 2 is indicated by an arrow 5. The direction of travel of the motor vehicle is indicated by arrow 6, the driving of the motor vehicle being simulated by rotating the rolling device 1.

With regard to a particularly meaningful and comprehensive functional test, the rolling device 1 is at least slightly movable with at least two degrees of freedom. To determine the force generated by the motor vehicle during driving and / or braking movements of the motor vehicle, the force acting between the rolling device 1 and a predefinable fixed point 10 and / or the displacement path and / or angle of rotation occurring during driving and / or braking movements of the motor vehicle is measurable between the rolling device 1 and the predeterminable fixed point 10. The fixed point 10 is designed here as a mounting frame or mounting frame.

At this point it should be noted that the two wheels 2 of an axle should always be checked at the same time. As a result, in practice two test benches and more specifically two unrolling devices 1 are usually required to test both wheels 2 at the same time.

The rolling device 1 is suspended in a freely movable manner in all directions in all directions via a bearing 7 relative to the mounting frame or fixed point 10 and is preferably guided over an XYZ slide.

For measuring the occurring forces and / or distances, force measuring devices and / or measuring sensors 8 are provided, 8X representing a measurement transverse to the direction of travel, 8Y a measurement in the direction of travel 6 and 8Z a measurement in the vertical direction, for example for measuring the weight. The rolling device 1 is arranged in a frame 9 which is coupled to the rolling device 1. The entire frame 9 is movably supported relative to the fixed point 10.

The frame 9 in FIG. 1 is inserted into a floor recess into which the mounting frame 10 is inserted. In principle, it would also be conceivable for the force measuring device and / or displacement measuring device 8 to act within the frame 9 between the rollers 12, 15 provided there and the frame 9.

FIG. 2 shows a schematic top view of the test bench from FIG. 1 with its degrees of freedom indicated by arrows. The rotation about the Z axis in the direction of rotation 27 is also represented by arrows. A corresponding bearing 28 enables the rotation.

FIG. 3 shows a schematic side view of the rolling device 1 with a sliding device 16 acting under the tread 3. The sliding device 16 is designed as a sliding plate. The tread 3 is designed as a treadmill 14 which runs on the sliding device 16. A roller 12 serves as a drive roller which is driven by the rotary drive or motor 21. The rolling device 1 is additionally arranged in a special mounting frame 11, which is optionally coupled to the frame 9. The roller 15 is designed as a freely rotatable deflection roller. The treadmill 14 is pretensioned via a tensioning device 13 by moving the deflection roller 15 in such a way that it has a non-positive connection with the drive roller 12. Grooves 18 are provided in the sliding device 16 or in the sliding plate for the lateral force absorption.

The grooves 18 are particularly well visible in FIG. 4, which shows the rolling device 1 in a schematic plan view. The roller 12 is coupled to a belt wheel 19 which is coupled to a drive motor 21. The treadmill 14 has belts 14a formed as guide elements which run in the groove 18 and in grooves 17 which are formed in the rollers 12 and 15. This results in a safe absorption of lateral forces when the treadmill 14 is rotated. The treadmill 14 is not shown in FIG. 4 for the sake of simplicity. 5 and 6 show a further exemplary embodiment of a rolling device 1, a roller or roller arrangement 16a being provided here instead of a sliding device 16. Otherwise, FIGS. 5 and 6 correspond to FIGS. 3 and 4, with the mobility in the direction of travel 6 being represented by a double arrow 20 in FIGS. 4 and 6 to clarify the mobility of the rolling device 1. The rolling device 1 can optionally have a sliding device 16 or a roller or roller arrangement 16a.

Fig. 7 shows the test stand in a schematic front view in an underfloor installation. The motor 21 is arranged below the rolling device 1. The motor 21 is coupled to the rolling device 1 via a belt wheel 22 and a belt 23 and the belt wheel 19. The frame 11 of the tread 3 corresponds to the frame 9 of the entire rolling device 1.

Fig. 8 shows a schematic front view of a test bench in above-ground installation. The motor 21 is arranged laterally on the rolling device 1. Both from FIG. 7 and from FIG. 8 it can be seen that the motor 21 is always assigned to the unrolling device 1 and thus moves together with the unrolling device 1 against the selected fixed point 10 during measurement processes.

FIG. 9 shows the rolling device 1 in an embodiment with an XY slide bearing. FIG. 9 shows both a top view and a front view of the rolling device 1, which is mounted with its frame 9 in an installation frame and against a fixed point 10. Reference number 24 shows an XYZ frame with a ball guide and load cells. This frame 24 is movable relative to the fixed point 10. As a result, the rolling device 1 is freely movable in all directions.

10 shows the rolling device 1 in a schematic side view with an extended support roller 25 against which the wheel 2 can be supported.

With regard to further advantageous refinements of the test bench according to the invention, reference is made to the general part of the description and to the appended claims in order to avoid repetition. Finally, it should be expressly pointed out that the exemplary embodiments described above only serve to discuss the claimed teaching, but do not restrict it to the exemplary embodiments.

Claims

Patent claims

1. Test bench for motor vehicles, with a rolling device (1) having a rolling surface (1) for rolling the wheels (2), the running surface (3) being driven in rotation and preferably being lockable and / or braked and / or unlockable, characterized in that the Rolling device (1) with at least two degrees of freedom is at least slightly movable and that to determine the force generated by the motor vehicle during driving and / or braking movements of the motor vehicle, the force acting between the rolling device (1) and a predeterminable fixed point (10) and / or the displacement path and / or angle of rotation occurring during driving and / or braking movements of the motor vehicle between the rolling device (1) and a predeterminable fixed point (10) can be measured.

2. Test stand according to claim 1, characterized in that a degree of freedom corresponds to a movement transverse or perpendicular to the direction of travel (6) in a horizontal direction, in particular along an X axis.

3. Test stand according to claim 1 or 2, characterized in that a degree of freedom corresponds to a movement along the direction of travel (6), in particular along a Y axis.

4. Test stand according to one of claims 1 to 3, characterized in that a degree of freedom corresponds to a movement transverse or perpendicular to the direction of travel (6) in a vertical direction, in particular along a Z axis.

5. Test stand according to one of claims 1 to 4, characterized in that a degree of freedom corresponds to a rotation about a preferably vertical axis, in particular a Z axis.

6. Test stand according to one of claims 1 to 5, characterized in that the entire test stand is rotatable about a preferably vertical axis, in particular a Z axis.

7. Test stand according to one of claims 1 to 6, characterized in that the rolling device (1) is mounted in a lifting platform.

8. Test stand according to one of claims 1 to 6, characterized in that the rolling device (1) is mounted in a vehicle.

9. Test stand according to one of claims 1 to 8, characterized in that the rolling device (1) is mounted in a vibrating or vibrating device.

10. Test stand according to one of claims 1 to 9, characterized in that the rolling device (1) is mounted in a rotating device.

11. Test stand according to one of claims 1 to 10, characterized in that the rolling device (1) is mounted in a frame (9) which can be fixed on or in the floor or on a wall.

12. Test stand according to one of claims 1 to 11, characterized in that the rolling device (1), preferably via the frame (9), is articulated on a wall.

13. Test stand according to claim 12, characterized in that the articulation is carried out by means of a coupling element, preferably by means of a metal part.

14. Test stand according to claim 13, characterized in that the coupling element is integrally formed with the frame (9).

15. Test stand according to one of claims 11 to 14, characterized in that the coupling element and / or the frame (9) has at least one weakening at least one predeterminable point, so that bends and / or torsions, preferably via at least one associated with the coupling element Sensor (8) are detectable.

16. Test stand according to claim 15, characterized in that the weakening or weakenings are formed by recesses and / or millings.

17. Test stand according to claim 15 or 16, characterized in that at least one force transducer (8) and / or at least one sensor (8) for bends and / or torsions are or is arranged in the weakening or weakenings.

18. Test stand according to one of claims 1 to 17, characterized in that a separate rolling device (1) is provided for each wheel (2) of an axle.

19. Test stand according to claim 18, characterized in that each of the two rolling devices (1) is assigned to a separate frame (9).

20. Test stand according to claim 18, characterized in that both rolling devices (1) are assigned to a common frame (9).

21. Test stand according to one of claims 1 to 20, that the unrolling device (1) comprises at least two rollers (12, 15) or rollers and that around the rollers (12, 15) or rollers is designed as an endless belt, the tread (3) forming treadmill (14) runs.

22. Test stand according to one of claims 1 to 21, characterized in that the rolling device (1) comprises three or more rollers (12, 15) or rollers.

23. Test stand according to claim 21 or 22, characterized in that the rollers (12, 15) or rollers are mounted laterally in the frame (9) and run without a floor.

24. Test stand according to one of claims 21 to 23, characterized in that the rollers (12, 15) or rollers are guided laterally in roller bearings.

25. Test stand according to one of claims 21 to 23, characterized in that the rollers (12, 15) or rollers are guided laterally in sliding guides.

26. Test stand according to one of claims 1 to 25, characterized in that the rolling device (1) can be assigned a sliding device (16), preferably a sliding plate, or a roller or roller arrangement (16a).

27. Test stand according to one of claims 1 to 26, characterized in that the running surface (3) for absorbing the lateral forces has a lateral force absorption, preferably a belt (14a) or a flexible rib.

28. Test stand according to one of claims 1 to 27, characterized in that a roller (12, 15) or roller and / or a sliding device (16) or a roller or roller arrangement (16a) for absorbing lateral forces, a guide device, preferably a groove (17, 18), have or has.

29. Test stand according to one of claims 1 to 28, characterized in that the rolling device (1) is guided in the sense of an XY slide or XYZ slide.

30. Test stand according to one of claims 1 to 29, characterized in that the rolling device (1) is an independent functional module.

31. Test stand according to one of claims 1 to 30, characterized in that a drive module is an independent functional module and can preferably be placed on the unrolling device (1) in different ways or can be coupled to the unrolling device (1).

32. Test stand according to one of claims 21 to 31, characterized in that seen in the running direction in front of the first roller (12, 15) or roller, that is to say behind the wheel (2) located on the rolling device (1), a freely running support roller ( 25) is arranged, against which the wheel (2) is supported when braking.

33. Test stand according to one of claims 21 to 32, characterized in that, seen in the direction of travel behind the last roller or roller, that is to say in front of the wheel (2) located on the unwinding device (1), a freely running support roller is arranged against which supports the wheel (2) when accelerating.

34. Test stand according to claim 32 or 33, characterized in that the support roller (25) via lateral support arms (26) is held elastically and / or spring-loaded in the support position.

35. test stand according to claim 34, characterized in that the support roller (18) via the lateral support arms (26) is held in the support position such that it can be lowered from the tire (2) in the direction of travel while overcoming the elastic force or spring force and after Driving over is automatically erectable in the support position.

36. Test stand according to one of claims 32 to 35, characterized in that the support roller (25) can be driven over in a lowered state and, after driving over, preferably with the wheel (2) positioned on the rolling device (1), moved up and preferably into the support position can be locked there.

37. Test stand according to one of claims 32 to 36, characterized in that the support roller (25) can be moved into the support position when the wheel (2) is positioned on the unrolling device (1).

38. Test stand according to one of claims 32 to 37, characterized in that the support roller (25) can be moved from the lowered position into the support position via a mechanism, preferably via a worm drive.

39. Test stand according to one of claims 21 to 38, characterized in that the force absorption and / or the measurement of the displacement path and / or the angle of rotation between the rollers (12, 15) or rollers and the frame (9).

40. Test stand according to one of claims 21 to 39, characterized in that the force absorption and / or the measurement of the displacement path and / or the angle of rotation takes place within the rollers (12, 15) or rollers.

41. Test stand according to one of claims 21 to 40, characterized in that the force absorption and / or the measurement of the displacement path and / or the angle of rotation takes place in or on the bearings of the rollers (12, 15) or rollers.

42. Test stand according to one of claims 21 to 41, characterized in that at least one roller (12) or roller is designed as a non-positive drive roller or roller.

43. Test stand according to one of claims 21 to 42, characterized in that at least one roller (15) or roller is designed as a non-positive deflection roller or roller.

44. Test stand according to one of claims 21 to 43, characterized in that at least one motor (21), preferably an electric motor, is provided for driving at least one of the rollers (12) or rollers.

45. Test stand according to claim 44, characterized in that the motor (21) is arranged in the region between the rollers (12, 15) or rollers.

46. Test stand according to claim 44, characterized in that the motor (21) is arranged in the area under the rollers (12, 15) or rollers.

47. Test stand according to claim 44, characterized in that the motor (21) is arranged in one of the driven rollers (12, 15) or rollers or in the driven rollers (12) or rollers.

48. Test stand according to claim 44 or 47, characterized in that the motor (21) is an integral part of the roller (12, 15) or roller.

49. Test stand according to one of claims 1 to 48, characterized in that the rolling device (1) is assigned a heating device for the tread (3).

50. Test stand according to one of claims 1 to 49, characterized in that the rolling device (1) has a tensioning device (13) for tensioning the tread (3).

51. Test stand according to claim 50, characterized in that the tensioning device (13) has at least one spring acting between two rollers (12, 15) or rollers.

52. Test stand according to one of claims 1 to 51, characterized in that the surface of the tread (3) has a grain size with a predetermined grain size.

53. Test stand according to one of claims 1 to 51, characterized in that the surface of the tread (3) has a rubber pad of a predetermined thickness.

54. Test stand according to one of claims 1 to 53, characterized in that the surface of the tread (3) has a preferably printed image and / or text information.

55. Test stand according to one of claims 1 to 54, characterized in that the tread (3) is designed as a treadmill (14), preferably as a fabric belt.

56. Test stand according to one of claims 1 to 55, characterized in that the rolling device (1) is assigned a receiver for sound waves, preferably a microphone.

57. Test stand according to one of claims 1 to 56, characterized in that the rolling device (1) has a plurality of, preferably cascaded, running surfaces (3).

58. Test stand according to one of claims 1 to 57, characterized in that the test stand can be used as a road simulator.

59. Test stand according to one of claims 1 to 58, characterized in that the rolling device (1) has a device for setting a negative track.