Test measuring system for detecting and identifying play on vehicles

Abstract

The present invention relates to a device (1) for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles, comprising a rotatable support plate (2) provided for supporting a wheel (3) of a vehicle, and drive means provided to rotate the support plate (2) clockwise and / or anti¬ clockwise about a rotation point, wherein said rotation point is a virtual rotation point, and wherein said drive means comprise a first (4) and second (5) linearly displaceable carriage which are each linearly displaceable back and forth, wherein the support plate (2) is rotatably fastened to the first linearly displaceable carriage (4) about a second axis of rotation and is rotatably coupled to the second linearly displaceable carriage (5) about a third axis of rotation, such that the position of the virtual rotation point is settable by displacement of said carriages (4; 5).

Description

[0001] TEST MEASURING SYSTEM FOR DETECTING AND IDENTIFYING PLAY ON VEHICLES

[0002] The present invention relates to a device for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles, comprising a rotatable support plate provided for supporting a wheel of a vehicle, and drive means provided to rotate the support plate clockwise and / or anti -clockwise about a rotation point. The present invention furthermore relates to a method for detecting and identifying play with the aid of such a device.

[0003] The present invention relates in particular to a device suitable for detecting (recording) and identifying play of components which are susceptible to wear in a more reasonable and high-quality manner. Examples of connection-technical components are: wheel bearings, steering joints and suspension joints and vibration dampers (silent blocks) of two-axle or multi-axle vehicles. It relates more specifically to a device which makes it possible to check play -prone components which are directly or indirectly connected to a wheel and which negatively affect the steering and driving stability and thus have an impact on safety.

[0004] The term "play" is interpreted from an automotive technical viewpoint by garages and specialist test centres as the relative play of a component, with a distinction being made between original and non-original play by visual assessment.

[0005] Steering and suspension components of vehicles, which are mechanically coupled to a wheel, may cause various kinds of play on the wheel due to wear, which types of play can be located in a three-dimensional space and be defined in the following way:

[0006] - play in the longitudinal direction (longitudinally) (X): this direction corresponds to the driving direction of a vehicle;

[0007] - play in the transverse direction (transversely) (Y): this direction is perpendicular to the longitudinal direction;

[0008] - play in an upward and downward movement (Z) of a wheel;

[0009] - play in a differentiated direction using a combination of X, Y and Z as reference. There is a causal connection between the play on a wheel and the play of these components. A deviation from the normal geometrical position of a wheel is proportional to the magnitude of the play of these components.

[0010] The decision to reject or replace a component on the basis of visible play has until now often depended on the subjective perception of the technician, and also the visual limitations for covered components. Use may be made of a play detector in this case. Apparatuses of this type, the operational principle of which is based on movable plates onto which the wheels of a vehicle to be checked are placed and which are movable back and forth in a direction corresponding to the transverse direction or longitudinal direction of the vehicle, are known and are described, inter alia, in Belgian patent BE 772697 and European patent EP 1 327 117 in the name of the inventor stated for the present patent application.

[0011] Everyday practice shows that this generation of apparatuses is no longer adequate for investigating play in steering and suspension components since the steering system and stability of vehicles has to meet increasingly higher requirements because of the road safety, inter alia, of automatic driver assistance systems. The reason for this is that the mechanical connection between the wheel and the chassis in the higher-priced vehicle segment has evolved to a more complex geometrical and multi-link suspensions, and rear-wheel steering. Furthermore, it is found that, both at national and international level, the authorized test centres for vehicles, the car service branch, and the official authorities are demanding more uniformity and standardization in the field of investigating play.

[0012] A number of years ago, the patentee was granted a European patent EP 2488 823 (WO 2011 / 045664) for a play detector in the form of a 3D wheel manipulator. This play detector comprises support means which can generate a movement in three directions (X, Y, Z) exerted on a wheel. The respective support means comprise a transmission member (transmission) in the form of a carriage which is movable in a first longitudinal direction (X) parallel to the axis of symmetry of a vehicle and which is provided with wheel-clamping means which move, according to a superposition, in a second direction (Y) directed to a wheel of the carriage and move in a third direction (Z) which lifts a wheel of the carriage. The lifting activation is thus proportional to a function of the transverse activation. Such a device can exert different (three- dimensional) forces on a wheel of a vehicle. However, the respective play detector has the drawback that it cannot be used to check vehicles having a different track width, i.e. the distance between two wheels on the same axle, for measurement purposes. It has been found that it is difficult to incorporate a suitable measuring system which is able to record the play.

[0013] European patent publication EP 0 011 100 describes a device which is used to determine the play between parts of the wheel suspension and the steering in a motor vehicle, in which only one single support plate is used to drive a wheel which has been arranged thereon in opposite directions, while the other wheel on the vehicle axle is supported in a fixed manner.

[0014] American patent publication US 4,966,376 and the International patent publication WO 96 / 07884 also describe a device for inspecting the play of wheel, steering and suspension components of a vehicle.

[0015] Furthermore, the International patent publication WO 2022 / 049553 describes a device for detecting and identifying play of vehicles, comprising a linearly displaceable carriage and a rotatable support plate provided for supporting a wheel of a vehicle, wherein said carriage is displaceable with respect to the support plate in a direction corresponding to the transverse direction of the vehicle, wherein the displaceable carriage is equipped with a rotatable structure provided for rotating the support plate about an axis of rotation. The device described in WO 2022 / 049553 has the advantage that movement cycles are compatible with the measurement identification of play, but in practice it has been found that the device in question makes it very difficult to check, inter alia, vibration dampers (silent blocks) of vehicles in a high-quality manner, which in itself is a significant shortcoming since there are several vibration dampers of this kind on heavier electrically powered vehicles. Since the proportion of electric vehicles will only increase in the future, a device which allows the user thereof to check vehicles for play in a clear and high-quality manner is of critical importance.

[0016] It is therefore an object of the invention to provide a device for detecting and identifying play, by means of which it is possible to detect the play in a high-quality manner, irrespective of the track width, the wheel diameter and / or the tyre width of the vehicle to be checked. An additional object of the present invention is to create a device which can be used to record the play, preferably by positioning directly with two wheels of the same axle on the device, and in particular without needing to use any additional connection of tools.

[0017] The object of the invention is achieved by providing a device for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles, comprising a rotatable support plate provided for supporting a wheel of a vehicle, and drive means provided to rotate the support plate clockwise and / or anti-clockwise about a rotation point, wherein said rotation point is a virtual rotation point, and wherein said drive means comprise a first and second linearly displaceable carriage which are each linearly displaceable back and forth, wherein the support plate is rotatably fastened to the first linearly displaceable carriage about a second axis of rotation and is rotatably coupled to the second linearly displaceable carriage about a third axis of rotation, such that the position of the virtual rotation point is settable by displacement of said carriages. The device according to the present invention will for example detect and identify play, and is at the same time capable of interpreting the result of the play detected. In particular, the position of the virtual rotation point is settable on the basis of the displacement distance and the displacement speed of the two linearly displaceable carriages. The displacement distance and the displacement speed is for example settable separately for each carriage, and this displacement distance and / or displacement speed can be the same for both carriages but may also differ. In this way, what is obtained, as it were, is a multifunctional settable virtual rotation point. The drive means may also be set in such a way that they are able to linearly displace the support plate back and forth, for example in the driving direction.

[0018] The virtual rotation point will be positioned virtually on the support plate. Extending through this virtual rotation point is a first virtual axis of rotation about which the support plate will rotate. This first virtual axis of rotation extends perpendicularly to the support plate. Therefore, said virtual rotation point can be considered to be the projection of the virtual rotation axis line Z onto the XY plane. The virtual rotation point is an imaginary rotation centre within a system, which gives the impression that a component, i.e. the support plate, rotates about a fixed axis, whereas this fixed axis is in fact not present.

[0019] In use, the support plate will rotate about the virtual rotation point. The movement may be centric or eccentric.

[0020] In a possible embodiment, the position of said virtual rotation point may be set as desired, for example as a function of the contact surface (pressure point) of the tyre of the vehicle to be checked. In the remainder of the present patent text, the term "pressure point" or "wheel pressure point" will be used for this. This pressure point should be considered to be the reference point for the device and is dependent on the vehicle to be checked. In practice, the respective reference point will be computed mathematically by a processing unit, which forms part of the device, on the basis of the distribution of the acting forces (at the centre of gravity of the tyre) in the movement directions (in the XY plane) of the support plate.

[0021] The respective rotation point is preferably located between the minimum and maximum track width of the vehicles to be checked. In an alternative embodiment, this rotation point is located in a zone outside the minimum and maximum track width of the vehicles to be checked. In another possible embodiment, the position of the virtual rotation point may form part of a preprogrammed, automatically set positioning of the virtual rotation point in a test cycle for specifically locating play on connection- technical components: wheel bearings, steering joints and suspension joints and vibration dampers (silent blocks), etc. Once positioned, the support plate can be rotated according to a specific rotation angle in order to detect (any) play. The play angle is derivable from the set rotation angle. The position of the virtual rotation point is for example settable in the X or Y direction, the X direction being the direction in the driving direction and the Y direction extending transversely to the X direction. The track width of a vehicle to be checked is also determined in the Y direction.

[0022] By using a (settable) virtual rotation point, the position of which is programmable, it is possible to, in the case of the device according to the invention, allow the support plate to exert a large number of movements (but also activate forces) in the support surface of the wheel supported on this support plate, including: concentric rotation (to check the steering components), eccentric rotation (to check the suspension components) and linear displacement (to check the vibration dampers), in order to in this way check the desired wheel, steering or suspension component of the vehicle for play.

[0023] The device according to the invention makes it possible to preprogramme a number of different movement cycles (test cycles) for the support plate in order to in this way check one or more connection-technical components of a vehicle for play by specifically desired investigation of play. In the detailed description of the present patent text, a number of possible test cycles will be described in more detail.

[0024] Due to the fact that the support plate is rotatably coupled both about a second axis of rotation, which is associated with the first carriage, and about a third axis of rotation, which is associated with the second carriage, the support plate can be rotated about a virtual rotation point, the position of which is settable as a function of the displacement and the displacement speed of the respective carriages. In practice, the position of the virtual rotation point is set as a function of the positioning of a wheel of the vehicle to be checked on the support plate and more particularly with respect to the pressure point of the respective wheel. The angular rotation of the support plate will always be carried out with respect to the (maximum) pressure point of the wheel on the support plate, such that it is necessary to ensure that the respective pressure point is considered to be the reference with respect to the virtual rotation point when carrying out the play detection. According to an advantageous embodiment of the device according to the invention, in use, the location of the virtual rotation point coincides with the pressure point of a wheel on the support surface of the support plate, or, in use, the virtual rotation point is located at a distance from the pressure point of a wheel on the support surface of the support plate, in order to rotate the support plate centrically or eccentrically, respectively. For example, the position of the pressure point corresponds to the centre of the projection of a wheel mass onto the support surface of the support plate.

[0025] In this way, the rotating movement of the support plate will be effected in the X-Y plane, it being possible for the support plate to generate forces in one of the four quadrants of the X-Y coordinate system (here X is the driving direction and Y the transverse direction). This makes it possible for either linear, centric or eccentric forces to be generated with respect to the pressure point.

[0026] For carrying out a specific investigation on a vehicle, the respective pressure point will first be determined. As soon as the position of the pressure point is known, the predetermined movement cycles for the support plate will be carried out successively, the position of the virtual rotation point being set as a function of the specific investigation of wheel or steering components.

[0027] The support plate is preferably manufactured from metal. Metal offers the advantage that it is strong enough to support a vehicle. The support plate has an upper and lower surface, the upper surface forming the support surface for a wheel of a vehicle to be checked. The support surface is preferably provided with a suitable material surface having a high friction coefficient. In order to pursue optimal positioning of a wheel, the support plate has a V-shaped cross section in a possible embodiment. The V-shaped cross section offers the advantage that wheels, irrespective of their diameter, can be centred on the support plate. In an alternative embodiment, the support plate may comprise a hollow, such as a bowl-like hollow, capable of creating an optimal contact surface for a wheel of a vehicle. The support plate may also have a cross section different from a V-shaped one. For instance, it is possible for the support plate to be flat and be provided with a sufficiently rough material surface.

[0028] In a possible embodiment of the invention according to the invention, the first and second linearly displaceable carriage are each linearly displaceable back and forth in a direction corresponding to the driving direction of the vehicle.

[0029] Depending on the mass of the vehicles to be checked, it is important for the support plate to be sufficiently supported. To this end, in a particular embodiment, the first linearly displaceable carriage comprises a slewing ring bearing for supporting the rotatable support plate. This slewing ring bearing will absorb the axial and radial forces induced.

[0030] In a more particular embodiment of the device according to the invention, the drive means further comprise a first and second drivable spindle for driving the first and second linearly movable carriage, respectively. The spindles are preferably each driven by a specific actuator.

[0031] In order to check the wheels of a vehicle for play, there are preferably two devices, specifically a left-hand and right-hand device, according to the invention, which are placed at a distance from each other, preferably symmetrically, in order to in this way check the front or rear wheels of a vehicle. Two devices of this kind form a system for detecting and identifying play. In order to automatically determine the position of a wheel placed on the support plate, in a possible embodiment the device according to the invention comprises one or more measuring means, preferably in the form of sensors (measuring cells), preferably force sensors. In an alternative embodiment, the position of a wheel placed on the support plate may be determined with the aid of measuring means in the form of an optical camera or distance sensors. Said force sensors are preferably suitable for automatically determining the (maximum) pressure point of the wheel supported on the respective support plate of the device.

[0032] In the case of the device according to the invention, the second linearly movable carriage comprises a movable slotted piece having a slot-like opening, which opening extends in a direction transverse to the driving direction of the vehicle, and in which the third axis of rotation is displaceably positioned. The slot-like opening ensures that the eccentric movement of the third axis of rotation, which can occur when the support plate rotates, is accommodated by virtue of the movable slotted piece.

[0033] The device according to the invention makes it possible to also measure and record the play, and to this end, in a particular embodiment, the device comprises first measuring means in order to determine the displacement of the support plate, and second measuring means in order to measure the displacement force generated, and the device is provided in order to indicate play on the basis of the signals generated by the measuring means. Preferably, for this the device comprises a suitable processing unit which can convert the generated signals and can be visualized on a read-out unit in the form of a diagram in which the generated force is plotted as a function of the displacement. This makes it possible to produce an objective indication system which can specifically determine play. The end result of a measurement is preferably coupled to a SMART -formulated evaluation and a risk analysis in order to determine whether the vehicle is "safely permissible for road traffic" (SMART is an acronym for Specific, Measurable, Achievable, Realistic and Time-bound). It is used as a set of criteria for clearly and efficiently defining goals and test results. It helps to set goals which are well defined and effective to achieve and evaluate. Devices of this kind may specifically be placed in automotive test centres and garages, such that when play is determined, targeted maintenance of steering and suspension components can be carried out. For example, the first measuring means are provided to determine the rotational or linear displacement of the support plate and the second measuring means are provided to measure the rotational or linear force generated.

[0034] The present invention also relates to the use of the device as described in the claims in order to detect and / or indicate the play of one or more wheel, steering and suspension components of one or more wheels of a vehicle and / or aircraft.

[0035] The present invention also relates to the use of the device as described in the claims in order to check the brake system of a vehicle and / or aircraft, more particularly the device can be used to check whether the brakes of a vehicle and / or aircraft meet the safety requirements. The device according to the invention as described for this, in the attached claims or in the detailed description, can thus be used as a brake test bench. The device according to the invention specifically allows the braking forces to be measured. By carrying out a wheel-by-wheel measurement, it is possible to verify whether there is a braking imbalance between the wheels of the same axle. The device according to the invention makes it possible to accurately determine the braking imbalance between the wheels of the same axle by comparing the measured braking forces with each other in percentage terms. If desired, the device is provided with a display unit in order to graphically display the measured results as a forcedisplacement curve, the braking force in Newtons being plotted against the translation of the activation. If the device is employed for testing brake systems, the support plate is considered to be a brake plate. The respective brake plate will for example have a V-shaped cross section or be provided with a hollow. In an alternative embodiment, the brake plate is provided with a support surface having a sufficiently high friction coefficient. The present invention further relates to a system for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles, comprising a first and a second device, the device as described in the claims, wherein the support plate of the first device is provided for supporting a left-hand wheel of a vehicle, and wherein the support plate of the second device is provided for supporting a right-hand wheel of a vehicle.

[0036] Another object of the present invention relates to a method for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles with the aid of the system according to the present invention and as described in the relevant independent claim, wherein the method comprises the following steps:

[0037] - placing a vehicle on said system in such a way that the left-hand front or rear wheel rests on the support plate of the first device and the right-hand front or rear wheel rests on the support plate of the second device;

[0038] - with the wheels in the braked state, simultaneously moving the first and second carriage of each device forwards in order to determine the wheel pressure point for each support plate about which the support plate is rotatable clockwise and / or anti-clockwise, preferably simultaneously moving the first and second carriage of each device forwards and backwards in order to determine the pressure point and in order to determine the position of a virtual rotation point for each support plate about which the support plate is rotatable clockwise and / or anti-clockwise;

[0039] - determining the position, movement direction and movement speed of each carriage in order to allow the support plate coupled to the carriages to rotate about its respective virtual rotation point that was determined;

[0040] - rotating said support plates, such that play can be detected.

[0041] In an alternative embodiment of the method in question according to the invention, said support plates can also be simultaneously moved forwards and backwards instead of rotating, such that the condition of wear of vibration dampers can be checked. Vibration dampers of this kind are provided on heavier (> 2000 kg) electrically powered vehicles. In order to set the rotation of the support plate, the virtual rotation point is located for example on the virtual axis line corresponding to the axis line of the track width of the vehicle. When adjusting the rotation of the support plate, the virtual rotation point lies for example on a virtual axis line extending in the direction of the track width of the vehicle. Furthermore, the angular rotation of the support plate is preferably set by defining the virtual axis line and allowing the support plate to rotate about a virtual rotation point.

[0042] In order to further illustrate the properties of the present invention and to indicate additional advantages and particular features thereof, a more detailed description of the device and method according to the invention will now be given. It will be clear that nothing in the following description may be interpreted as a limitation of the protection as laid down in the claims.

[0043] In the present description, reference numerals are used to refer to the attached drawings, in which:

[0044] - Figure 1 is a perspective illustration of a system for detecting and identifying play, constructed from two devices according to the invention placed symmetrically with respect to each other;

[0045] - Figure 2 shows a perspective illustration of the device according to the invention;

[0046] - Figure 3 shows a perspective illustration of the device according to the invention which illustrates that both vehicles provided with wheels of a smaller diameter and vehicles provided with wheels of a larger diameter can be checked using the device according to the invention;

[0047] - Figure 4 is an illustration of the device according to the invention in which the support plate is decoupled from the first and second linearly displaceable carriage;

[0048] - Figure 5 is a perspective illustration of part of the device according to the invention, specifically the first and second linearly displaceable carriage;

[0049] - Figure 6 shows the lower side of the rotatable support plate;

[0050] - Figure 7 shows the fixedly mounted guide system via which the first and second linearly displaceable carriage are displaced;

[0051] - Figure 8 is an illustrating figure of the spindle axes and force sensors; - Figure 9 illustrates where the force sensors (measuring cells) of the device are located, and also the slewing ring bearing and the slotted piece;

[0052] - Figure 10 is an illustrative example of the rotation of the support plates;

[0053] - Figure 11 shows the devices depicted in Figure 10, but without the support plate, such that the positions of the first and second movable carriages are visible;

[0054] - Figure 12 illustrates the determination of the wheel pressure point;

[0055] - Figure 13 illustrates the determination of the virtual rotation point;

[0056] - Figures 14 to 21 show a number of examples of the position that the first and second carriage can assume during a specific investigation of play;

[0057] - Figure 22 shows a graphical illustration of an investigation of play carried out on steering components with play;

[0058] - Figure 23 shows a graphical illustration of an investigation of play carried out on steering components without play.

[0059] The device (1) according to the present invention is a measuring apparatus used to detect and measure play in steering and wheel mechanisms of a vehicle. This is done by activating forces on a wheel (3) of a vehicle, more specifically the device is used to generate forces in the support surface (pressure point) of a wheel of the vehicle. With the aid of the device (1) according to the invention, it is possible to optimize the diagnostic process for the investigation of play by capturing measurement data and graphically recording the relationship between moving components of a steering and / or wheel suspension.

[0060] Using the device (1) according to the invention, it is possible to record measurement data; movements occurring under the influence of activating forces, exerted in the support surface of a wheel on different components of the suspension, can be charted. The device can be used to quantify and analyse various variables, such as force, play, slip angle, rotation angle and displacement.

[0061] In addition, the device (1) in question is also equipped to make it possible to use telemetry, by means of which measurement data can be remotely sent to a receiving station for further analysis. Transduction is used to visualize this measurement data, as a result of which they can be easily interpreted. Another option in the case of the device (1) according to the invention is the possibility of labelling, in which unique identification means are assigned to particular components of the steering and wheel suspension system. This makes it possible to follow, trace and identify wear processes, for example in vibration dampers, bearings, steering rods and joints.

[0062] Furthermore, the device (1) allows the use of telemonitoring in order to in this way capture the data and measurement results. A database can be constructed per checked vehicle, such that the measured data can be compared with each other periodically, for example during an annual (mandatory) inspection. In this way, it is possible for an (evolving) wear process to be charted, previously measured values to be compared, and specifically targeted test investigation to be performed in the event of a potential re-inspection. Diagnostic measurement data are analysed in terms of safety standards on the basis of slip-play curves in order to detect possible wear problems in the steering and wheel mechanism.

[0063] In order to then be able to check the wheels of vehicles of different track width (track width in a car is the distance between two wheels of the same axle, thus over the width of the vehicle, and is always measured on the ground from the centre of each tyre) for play, the present invention provides a system (11) suitable for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles.

[0064] A system (11) of this kind is presented in Figure 1 and is constructed from two similar devices (1) which also form subject matter of the present invention. The one device (1.1) is used to check the left-hand wheel (3) for play, whereas the other device (1.2) is used to check the right-hand wheel (3) for play. In the description that follows, the device (1) used is discussed in detail.

[0065] The device (1) according to the invention, which inter alia is presented in Figures 2 and 4, comprises a movable, for example a rotatable, support plate (2) provided for supporting a wheel (3) of a vehicle, and drive means provided to rotate the support plate clockwise and / or anti-clockwise about a rotation point. It is a particular feature of the device (1) according to the invention that this rotation point, about which the support plate (2) will rotate when carrying out the play detection, is a virtual rotation point, the position of which is pre-settable (programmable). The position of this virtual rotation point is in practice dependent on the investigation to be carried out. It is located in a virtual manner on the support plate and, when the device is used, will assume a position with respect to the known pressure point of the wheel of the vehicle to be checked which is in itself dependent on the track width of the vehicle to be checked. During the use of the device (1), this virtual rotation point will either coincide with the pressure point or be located at a distance from the pressure point of a wheel (3) on the support surface of the support plate (2), this being dependent on whether it is desired to rotate the support plate centrically or eccentrically. The support plate will rotate centrically if the virtual rotation point coincides with the pressure point of the wheel of the vehicle to be checked. The support plate will rotate eccentrically if the virtual rotation point is located at a distance from the pressure point of the wheel of the vehicle to be checked.

[0066] By using a (settable) virtual rotation point, it is possible to, in the case of the device (1) according to the invention, allow the support plate (2) to exert a large number of movements on the wheel (3) supported on this support plate (2), including: concentric rotation (to check the steering components), eccentric rotation (to check the suspension components) and linear displacement (to check the vibration dampers), in order to in this way check the desired wheel, steering or suspension component of the vehicle for play. The support plate can specifically carry out the following movement cycles with respect to a computed pressure point of a wheel support surface:

[0067] 1. Concentric rotation cycle activated in the wheel support surface;

[0068] 2. Eccentric rotation cycle in the wheel support surface; a. by displacing the virtual axis along the x and / or y axis line; b. X = axis line of the driving direction; c. Y = axis line of the track width - perpendicular to the driving direction;

[0069] 3. Linear movement cycle in the wheel support surface: a. force activation in the driving direction on a braked wheel; b. force activation in the backward driving direction on a braked wheel. The support plate (2) is movable with respect to said rotation point with the aid of drive means. To this end, the drive means comprise a first (4) and second (5) linearly displaceable carriage, wherein each carriage is linearly displaceable back and forth in a direction corresponding to the driving direction of the vehicle, with the aid of a first (7) and second (8) drivable spindle, respectively. Each spindle (7; 8) is driven by its own actuator, preferably in the form of a servo motor. The support plate (2) is fastened to the first linearly displaceable carriage (4) in such a way that the support plate can rotate about a second axis of rotation and the support plate is rotatably coupled to the second linearly displaceable carriage (5), as a result of which this support plate is also rotatable about a third axis of rotation, such that displacement of said carriages, each at a specific speed and over a specific distance, makes it possible to set the position of the virtual rotation point with respect to which (about which) the support plate (2) will move, for example rotate.

[0070] In order to linearly displace the first (4) and second (5) carriage, the device (1) comprises, as is inter alia visible in Figure 7, first and second guide means, respectively, which are provided on a base plate (14), for example manufactured from aluminium. In the case of the device depicted, the first guide means comprise two parallel straight guide rails (13.1) which extend in a direction corresponding to the driving direction (X direction) of the vehicle which is intended to be checked for play. The second guide means are the same as the first and comprise two parallel straight guide rails (13.2) which extend in a direction corresponding to the driving direction of the vehicle which is intended to be checked for play. Said carriages (4; 5) are movable back and forth in their respective guide means by means of the spindle (7 or 8) coupled thereto which is driven by a servo motor. The control of the two spindles (7; 8) will be effected by a dedicated encoder, a first encoder for the control of the first spindle (7) and a second encoder for the control of the second spindle (8).

[0071] The upper surface of the support plate (2) forms the support surface for the wheel (3) to be checked. In order to obtain good wheel positioning, a V-shaped wheel hole (15) (wheel bowl) is mounted on the support plate (2). The two sides of the wheel bowl (15) may be provided with gripping strips. It goes without saying that instead of mounting a wheel bowl on the support plate (2), the support plate (2) may have such a shape that a wheel bowl forms an integral part of the support plate (2). The support plate (2) is manufactured from metal, preferably stainless steel. The dimensions of the support plate (2) are dependent on the type of vehicle (for example passenger car or lorry) that it is desired to check. For instance, the support plate (2) may have the following dimensions for a passenger car: 750 mm x 400 mm x 10 mm (L x B x thickness).

[0072] For carrying out an investigation of play using the system (11) according to the invention, it is in the first place always important to determine where the wheels (3) of the vehicle to be checked are located in order to subsequently determine the coordinates of the virtual rotation point about which the support plate (2) of the device will rotate. The computed pressure point corresponds to the support point of the wheel mass, and more specifically the point where the maximum wheel loading is exerted by the vehicle in the support surface of the tyre. Within the context of this patent text, it is assumed that the position of the centre of gravity of the wheel mass lies, with respect to the theoretical centre, in the wheel support surface. In the remainder of this patent text, this point will be described as the pressure point (16). As will be apparent from the patent text below, the position of this pressure point (16) can be computed on the basis of the position of a wheel on the support plate (2).

[0073] In order to determine the position of the wheel (3) on the support plate (2), each device (1) is provided with one or more sensors (measuring cells), preferably in the form of force sensors (12). To this end, as illustrated in Figure 8, a force sensor (12) is located at the level of each spindle (7; 8). In practice, the system will have four force sensors, two for the first device (1.1) provided for supporting a left-hand wheel of a vehicle, and two for the second device (1.2) provided for supporting a right-hand wheel of a vehicle.

[0074] Instead of specific measuring cells or force sensors for automatically determining the position of the wheel on the support plate of a specific device, there are also other possibilities, such as using distance sensors, or via an optical camera, or via a laser, etc. Once it is known where the pressure point (16) of the wheel supported on the support surface (3) of the respective device (1.1; 1.2) is located, it is known where the virtual rotation point can be programmed as a function of the test cycles of the investigation of play. Subsequently, a processing unit can be used to compute what the position, movement direction and speed of the two carriages (4; 5) of the device must be in order to thus ensure that the support plate of the device will rotate about this virtual rotation point.

[0075] The check for play is effected by rotating the support plate (2) of each device (1.1; 1.2). In order to be able to rotate the support plate (2), the first linearly movable carriage (4) of the respective device (1.1; 1.2) comprises, as inter alia shown in Figures 4 and 5, a slewing ring bearing (6) which is provided to rotate the support plate (2) about a second axis of rotation, and the second linearly movable carriage (5) comprises a movable slotted piece (9) having a slot-like opening (10), which opening (10) extends in a direction transverse to the driving direction (X) of the vehicle, and in which the third axis of rotation is displaceably positioned.

[0076] As previously described, which components of the vehicle are checked for play is determined by the movement cycle for the support plate. Thus, for example the wheel bearings and steering mechanism will be able to be checked by rotating the support plate (2) concentrically, whereas the suspension components and also the ball joints will be able to be checked when the support plate (2) is rotated eccentrically.

[0077] Once the wheel (3) of a vehicle to be checked has been positioned on the support plate (2), it will, as previously indicated, be determined where the wheels are located in order to thus determine the maximum pressure point (16). Once this pressure point (16) has been determined, the investigation of play can be carried out by moving, often rotating, the support plate. Depending on the investigation to be carried out, the support plate will rotate centrically or eccentrically about a virtual rotation point. In the case of a centric rotation, the virtual rotation point will coincide with the pressure point, indicated by reference numeral " 16", whereas in the case of an eccentric rotation, the virtual rotation point will be located at a distance from the pressure point. With reference to Figure 12, where a first (1.1) and second (1.2) device are schematically depicted, wherein the support plate (2), the so-called left-hand support plate, of the first device (1.1) will support a left-hand wheel of a vehicle and the support plate (2), the so-called right-hand support plate, of the second device (1.2) will support a right-hand wheel of a vehicle, the following step-by-step plan can be followed in order to find the pressure point (16) and the virtual rotation point about which the lefthand and right-hand support plate will rotate:

[0078] - the support plate on which the wheel has been positioned with the wheel braked is moved forwards, in the driving direction of the vehicle, by simultaneously displacing the two carriages (4; 5) forwards with the aid of the first (7) and second (8) spindle;

[0079] - the braking force F is measured per support plate by two measuring cells (load sensor) in the form of two force sensors (12), where F= Fl + F2. The mutual distance 1 between the measurement points is equal to the distance between the force sensors and corresponds to the known data from the installation. on the basis of these 2 equal or differing measured forces, the position of the pressure point (16) for both the left-hand and right-hand wheel can be computed according to the track width (Y), with the aid of the following computation: where Dy = the track width of the vehicle to be checked; FL,1 is the measured force of the force sensor (12) connected to the first carriage (4) of the first device; FL, 2 is the measured force of the force sensor (12) connected to the second carriage (5) of the first device (1.1); FR,1 is the measured force of the force sensor (12) connected to the first carriage (4) of the second device (1.2); FR,2 is the measured force of the force sensor (12) connected to the second carriage (5) of the second device (1.2); DL,y: reference for the virtual distance positioning of the pressure point on the left; DR,y: reference for the virtual distance positioning of the pressure point on the right. In the ideal situation, the vehicle is placed perfectly symmetrically on the system according to the invention; in other words, when driving the vehicle onto the respective devices, the left-hand and right-hand wheel, depending on the track width, are positioned symmetrically at an equal distance from the centre. This is in the ideal case, but usually a driver will position their vehicle more to the left or more to the right - in other words the wheels will be more to the left or more to the right on one of the devices. Therefore, a + or - sign is used in the Y direction in order to determine the exact location of maximum loading of a tyre (pressure point) on the support plate. It is desired to determine the location of the 2 pressure points on the support plates on the left and on the right exactly in the Y direction (track width). So it is attempted to determine the origin (reference for the virtual distance positioning of the pressure point on the left dLy and reference for the virtual distance positioning of the pressure point on the right dRy for the two wheels on the system) for the left-hand and right-hand device. This makes it possible to determine where the vehicle is on the support plates.

[0080] There follows below an illustrative example in which the pressure point of the front wheels of a vehicle, more specifically the front axle of a BMW, was computed by means of the previously described approach.

[0081] At the pressure point (16) computed, a coordinate system according to the driving direction (X axis) and track width (Y axis) can be introduced in order to establish the exact coordinates of the virtual rotation point. The virtual rotation point (concentric or eccentric with respect to the pressure point) can be programmed in the various quadrants of the X-Y coordinate system.

[0082] Once it is known where the maximum pressure point (16) of a wheel is located, the position and the speed of the two displaceable carriages (4, 5) can be determined in order to thus allow the support plate to rotate about a virtual rotation point. This will be effected on the basis of the following formulae:

[0083] Formulae: Position of spindles:

[0084] On the basis of the values from the illustrative example, the next position of the spindles, which is also illustrated in Figure 13, is then obtained and the speed at which the two spindles will move can also be computed.

[0085] Once the pressure point (16) of a wheel on the support plate has been determined, a virtual axis line (D) can be set. The virtual axis line is the line drawn through the centre of the bearing block of the slewing ring bearing, the slotted piece and the axis line of the spindles. The pressure point (16) of the wheel is at a concentric or eccentric distance from this virtual axis line (D).

[0086] Below, a number of possible settable movement cycles for carrying out an investigation of play will be briefly described with reference to Figures 14 to 21.

[0087] 1. The first (4) and second (5) carriage move, under the influence of their first (7) and second (8) spindle, simultaneously (in the same direction) over the same distance (vl = v2), as a result of which the support plate (2) moves in the driving direction (Figure 14.1) or in the opposite direction (Figure 14.2) (X direction).

[0088] 2. The first (4) and second (5) carriage move, under the influence of their first (7) and second (8) spindle, simultaneously (in opposite directions) over the same distance (vl = v2), as a result of which the wheel support plate performs an angular rotation (through a set angle) clockwise (Figure 15.2) or anti -clockwise (Figure 15.1).

[0089] 3. The first carriage (4) moves in the driving direction forwards, as indicated in Figure 16.1, or backwards, as indicated in Figure 16.2, while the second carriage is positioned in the centre position.

[0090] 4. The second carriage (5) moves in the driving direction forwards, as indicated in Figure 17.1, or backwards, as indicated in Figure 17.2, while the first carriage (4) is positioned in the centre position.

[0091] 5. The first (4) and second (5) carriage move, under the influence of their first (7) and second (8) spindle, simultaneously (in opposite directions) over a different distance (vl v2), as a result of which the support plate performs an angular rotation clockwise (see Figure 18.2) or anti-clockwise (see Figure 18.1).

[0092] 6. The first (4) and second (5) carriage move, under the influence of their first (7) and second (8) spindle, simultaneously (in the same direction) over a different distance (vl v2), as a result of which the support plate performs an angular rotation clockwise (see Figure 19.1) or anti-clockwise (see Figure 19.2).

[0093] In the preceding examples (points 1 to 6), the pressure point was located exactly between the two carriages. In practice, depending on a vehicle with a minimum or maximum track width, pressure points may also be located beyond the movable carriages as illustrated in Figures 20 and 21, and not in the zone between the movable carriages, where: 7. The location of the pressure point (16) of the left-hand wheel (Figure 20.1) and the right-hand wheel (Figure 20.2) of a vehicle with a small track width is illustrated.

[0094] 8. The location of the pressure point (16) of the left-hand wheel (Figure 21.1) and the right-hand wheel (Figure 21.2) of a vehicle with a large track width is illustrated.

[0095] In summary, it can be stated that the device according to the invention and as described above offers all kinds of possibilities, including:

[0096] 1. Identifying play of covered (non-visible) vital components of steeringconnecting and wheel-connecting components;

[0097] 2. Checking rear steering (inter alia of heavier (> 2000 kg) electric vehicles);

[0098] 3. Higher-quality checking of the vibration dampers by carrying out a durability test:

[0099] 4. Automatic determination of the wheel position, wherein multifunctional orientations (programming of the position of the virtual axis) associated with the specific investigation of play can be programmed (various movement cycles - specifically focused investigation of play on steering and suspension components of a wheel);

[0100] 5. Higher-quality checking for play with regard to automatic driver assistance systems;

[0101] 6. Carrying out brake tests by wheel-by-wheel measurement of the braking forces.

[0102] In a test phase, an investigation of play was carried out using the device according to the invention, with steering components of a vehicle being checked for play by rotating the support plate centrically in the wheel support surface. Here, at the steering rod mounted on the left-hand side of the vehicle, play of 3.50 mm was established. On the steering rod mounted on the right-hand side of the vehicle, no play was established. The results of the investigation are displayed on the graphs shown in Figures 22 and 23, the displayed curves showing the relationship between the angular rotation and the applied torque (Nm). During the check, both the left-hand and right-hand wheel were tested, the play present on both sides being visualized and quantified. Analysis of the resulting (hysteresis) curve in comparison with a reference curve shows that there is a deviating play zone on the left-hand wheel (see Figure 22), while no deviation was observed on the right-hand side (see Figure 23). Internal tests by the patent proprietor have also shown that the device according to the invention can be used to still reliably detect a minimum play of 0.175 mm, with a rotation deviation of ±01° and a coupling arm length of 100 mm.

[0103] Furthermore, mechanical components, such as vibration dampers and ball joints, of a vehicle that are mounted between the wheel and the vehicle frame were checked for play by rotating the support plate eccentrically in the wheel support surface. An eccentric rotation cycle provides a play movement on components in the direction of the wear process as a result of braking and acceleration loading in terms of the driving direction. Play was also able to be derived from these tests. Elastic deformation of vibration dampers was also able to be determined by displacing the support plate 50 mm in the forward or backward driving direction.

Claims

AMENDED CLAIMS received by the International Bureau on January 19, 2026 (19.01.2026)CLAIMS1. Device (1) for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles, comprising a rotatable support plate (2) provided for supporting a wheel (3) of a vehicle, and drive means provided to rotate the support plate (2) clockwise and / or anti -clockwise about a rotation point, characterized in that said rotation point is a virtual rotation point, and in that said drive means comprise a first (4) and second (5) linearly displaceable carriage which are each linearly displaceable back and forth, wherein the support plate (2) is rotatably fastened to the first linearly displaceable carriage (4) about a second axis of rotation and is rotatably coupled to the second linearly displaceable carriage (5) about a third axis of rotation, such that the position of the virtual rotation point is settable by displacement of said carriages (4; 5), wherein the second linearly displaceable carriage (5) comprises a movable slotted piece (9) having a slot-like opening (10), which opening (10) extends in a direction transverse to the driving direction of the vehicle, and in which the third axis of rotation is displaceably positioned.

2. Device (1) according to Claim 1, characterized in that the first (4) and second (5) linearly displaceable carriage are each linearly displaceable back and forth in a direction corresponding to the driving direction of the vehicle.

3. Device (1) according to Claim 1 or 2, characterized in that, in use, the location of the virtual rotation point coincides with the pressure point of a wheel (3) on the support surface of the support plate (2), or in that, in use, the virtual rotation point is located at a distance from the pressure point of a wheel (3) on the support surface of the support plate (2), in order to rotate the support plate centrically or eccentrically, respectively.

4. Device (1) according to any of the preceding claims, characterized in that the first linearly displaceable carriage (4) comprises a slewing ring bearing (6) for supporting the rotatable support plate (2).

5. Device (1) according to any of the preceding claims, characterized in that the drive means further comprise a first (7) and second (8) drivable spindle for driving the first (4) and second (5) linearly movable carriage, respectively.

6. Device (1) according to any of the preceding claims, characterized in that the device (1) comprises one or more sensors, preferably force sensors in order to determine the position of a wheel (3) on the support plate (2).

7. Device according to any of the preceding claims, characterized in that the device (1) comprises first measuring means in order to determine the displacement of the support plate (2), and second measuring means in order to measure the displacement force generated, and in that the device (1) is provided in order to indicate play on the basis of the signals generated by the measuring means.

8. System (11) for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles, comprising a first (1.1) and a second (1.2) device according to any of Claims 1 to 7, wherein the support plate (2) of the first device (1.1) is provided for supporting a left-hand wheel of a vehicle, and wherein the support plate (2) of the second device (1.2) is provided for supporting a right-hand wheel of a vehicle.

9. Method for detecting and identifying play and checking the fastening of wheel, steering and suspension components of vehicles with the aid of the system (11) according to Claim 8, characterized in that the method comprises the following steps: placing a vehicle on said system (11) in such a way that the left-hand front or rear wheel rests on the support plate (2) of the first device (1.1) and the right-hand front or rear wheel rests on the support plate (2) of the second device (1.2); with the wheels in the braked state, simultaneously moving the first (4) and second (5) carriage of each device (1) forwards in order to determine the wheel pressure point for each support plate (2) about which the support plate (2) is rotatable clockwise and / or anti-clockwise; determining the position, movement direction and movement speed of each carriage (4; 5) in order to allow the support plate (2) coupled to the carriages to rotate about a virtual rotation point;rotating said support plates (2), such that play can be detected.

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