DE102019115902A1 - Method for detecting a torque acting on a wheel of a motor vehicle, torque detection device and test bench - Google Patents

Abstract

The invention relates to a method for detecting a torque acting on a wheel (10) of a motor vehicle (12) by means of a torque detection device (14), in which the torque detection device (14) is arranged on the wheel (10) and when the wheel ( 10) the torque acting on the wheel (10) is detected, a torque measuring flange (16) being arranged as a detection element of the torque detecting device (14) on a wheel hub (20) of a wheel suspension for the motor vehicle (12) and the wheel (10) on the torque measuring flange (16) is arranged. The invention also relates to a torque detection device (14) and a test stand (32).

Description

The invention relates to a method for detecting a torque acting on a wheel of a motor vehicle by means of a torque detection device, in which the torque detection device is arranged on the wheel and the torque acting on the wheel is detected when the wheel moves. The invention also relates to a torque detection device and a test stand.

It is known from the prior art that torque measuring rims, which are arranged on a motor vehicle that is to be measured, are used to determine drive train losses. In this variant, the tire to be measured is first mounted on the measuring rim. The original rim-tire combination of the motor vehicle can therefore not be used. The data transmission is usually done with a slip ring or with a telemetry system. Another variant for measuring the torque is to attach strain gauges to the drive shafts. This variant, too, requires additional expenditure when upgrading the motor vehicle with the measurement technology.

Furthermore, the WO 2017/013173 A1 a test device for a test stand for motor vehicles having a load device for applying a drive torque and / or a load torque to a hub of a motor vehicle to be tested, an adapter device which, in a test position, couples the hub of the motor vehicle to the load device, in particular to the shaft, and a support device for the adapter device, wherein the support device and the load device have a common movable base.

Furthermore, the DE 196 50 477 C1 a measuring device for measuring the braking torque in a motor vehicle with disc brakes. The device includes a dimension hub mounted on a wheel axle and connected to a wheel rim, which - viewed in the radial direction - is divided into an inner component section close to the axis and an outer component section which forms the edge area of the dimension hub and concentrically surrounds the inner component section. Both sections are connected to one another by radially extending webs on which sensors are applied, by means of which the bending stress acting on the webs due to the introduction of a torque can be measured. In order to be able to determine braking torques acting specifically on the disc brake with respect to other moments acting on the motor vehicle without superimposition, it is proposed that a brake disc of a braking device of the motor vehicle be concentrically surround the outer component of the dimension hub and fasten it to it alone.

The object of the present invention is to create a method, a torque detection device and a test stand by means of which a detection of the torque of a wheel for a motor vehicle can be detected in a simplified manner.

This object is achieved by a method, a torque detection device and a test stand according to the independent patent claims. Advantageous embodiments are specified in the subclaims.

One aspect of the invention relates to a method for detecting a torque acting on a wheel of a motor vehicle by means of a torque detection device, in which the torque detection device is arranged on the wheel and the torque acting on the wheel is detected when the wheel moves.

It is provided that a torque measuring flange is arranged as a detection element of the torque detecting device on a wheel hub of a wheel suspension for the motor vehicle and the wheel is arranged on the torque measuring flange.

This enables a simplified detection of the torque. This is made possible in particular because, for example, no additional measuring rims have to be arranged on the motor vehicle. The original rims with the original tire set can thus be arranged on the motor vehicle and a corresponding torque detection can nevertheless be carried out. This makes it possible, in particular, that the original configuration can be used for the motor vehicle, as a result of which the corresponding torques can be recorded for the original configuration of the motor vehicle.

In particular, the torque measuring flange is a specially made measuring flange that is integrated between the wheel hub and the rim.

According to an advantageous embodiment, the torque is recorded by means of a strain gauge of the torque measuring flange. This makes it possible in a simple manner to provide the torque measuring flange accordingly. Corresponding changes in electrical resistance of the strain gauge under load can then, for example by means of an electronic computing device of the torque detection device, the corresponding torque can be evaluated on the basis of the values of the strain gauge. In particular, the torque measuring flange can have a large number of strain gauges, in particular a strain gauge (DMS) bridge. As a result, an already established method for measuring the torque or for detecting the torque can also be used. This allows the torque to be recorded with high precision and with a low probability of failure.

Furthermore, it has proven to be advantageous if the torque is detected as a movement of the wheel when it is coasting and / or as the movement of the wheel when it is driven. In particular, this makes it possible for different losses, in particular drive train and wheel losses of the motor vehicle, to be recorded by means of the torque recording device. In particular, the different resistance forces of the motor vehicle on the drive train and on the wheel can thereby be determined on the basis of the detected torque when coasting and / or when driving the wheel. The wheel can be driven in particular by a corresponding motor in the motor vehicle or on the test bench, in particular an electric motor and / or an internal combustion engine.

Furthermore, it has proven to be advantageous if, when rolling out and / or driving the wheel through a test stand or when rolling out the wheel, a drive train resistance is determined on the basis of the detected torque by means of an electronic computing device of the torque detection device and / or when the wheel is driven by the motor vehicle On the basis of the recorded torque, a rolling resistance is determined by means of the electronic computing device in the test bench. In particular, this makes it possible for the different resistance forces of the motor vehicle, in particular on the drive and wheel, to be reliably determined. This enables detailed component development, especially for tires, wheel bearings, gears or brakes. In particular, however, the separation between the drive train resistance and the rolling resistance is necessary for the detailed component development, which is realized according to the invention.

In a further advantageous embodiment, a residual braking torque and a wheel hub loss are determined by means of the electronic computing device on the basis of the determined drive train resistance. In particular, the force at the wheel contact point can be determined precisely by measuring the dynamic wheel radius.
Furthermore, the slip on the tire can be determined via the speed detection of the torque detection device and the speed detection from the test bench.

It is also advantageous if the torque is detected by means of a telemetry device of the torque detection device, a rotor antenna being arranged on the torque measuring flange and a stator antenna being arranged on a holding element of the telemetry device arranged in a non-rotatable manner opposite the torque measuring flange. For example, it can be provided that the data is transmitted in real time by means of the telemetry device. The rotor antenna is arranged, in particular, on the torque measuring flange, while the stator antenna is fixed behind the brake disc, in particular in a rotationally secure manner, by means of the holding element via the brake caliper screws, for example. The torque can thus advantageously be detected by means of the torque detection device.

It has also proven to be advantageous if the torque is transmitted from the rotor antenna to the stator antenna by means of induction. As a result, data can in particular be transmitted in real time. This enables an improved detection of the torque.

Für eine detaillierte Komponentenentwicklung, beispielsweise für Reifen, Radlager, Getriebe, Bremse ist jedoch eine Trennung des Antriebsstrangwiderstands vom Rollwiderstand notwendig.It is also advantageous if the motor vehicle is arranged in a test stand in order to detect the torque. In particular, the test stand can be designed as a flat track test stand. The motor vehicle can then be arranged with its wheels on a belt unit in the flat track test stand and is fixed to the test stand at the front and rear using the towing hooks of the motor vehicle. Each belt unit consists of two running drums, which are connected with a coated steel belt. The front drum in the direction of travel is in particular provided with a drive unit. The rear drum is used in particular for belt tension and belt stabilization. There is a pneumatic air bearing under each wheel, which ensures that the tire contact point and the rolling behavior of the tire are similar to those on the road. The entire belt unit is also supported without friction by additional air bearings, so that the resistance forces, in particular the rolling and drive train losses, can be determined for each wheel (F _{x, wheel} ) at the force transducers: $${\mathrm{F.}}_{x,\mathrm{R.}ad}={\mathrm{F.}}_{\mathrm{R.}Ollwiderstand,\mathrm{R.}ad}+{\mathrm{F.}}_{\mathrm{A.}ntriebsstranGwiderstand,\mathrm{R.}ad}$$

For a detailed development of components, e.g. for tires, wheel bearings, gears, brakes, it is necessary to separate the drive train resistance from the rolling resistance.

Durch Subtraktion dieser Messwerte F_Dreh,Rad vom Flachbahnergebnis F_x,Rad kann gleichzeitig auch der Rollwiderstand des Rads spezifisch bestimmt werden: $$F_{Rollwiderstand,Rad}=F_{x,Rad}-F_{Dreh,Rad}$$

Darüber hinaus bildet diese Konstruktion die Radlast und die Achsgeometrie wie in der Originaleinbaulage im Kraftfahrzeug ab. Treibt das Kraftfahrzeug die Räder im Prüfstand an, wird über die Drehmomentmesstechnik direkt der radspezifische Rollwiderstand gemessen.For this purpose, a specially made torque flange is pushed onto the wheel hub of the motor vehicle and fixed by means of wheel bolts. The original wheel of the motor vehicle to be measured, consisting of the rim and tire, can then be mounted on the torque measuring flange with wheel bolts. If the motor vehicle is driven by the test bench, the drive train losses, including residual braking torques and wheel hub losses, can be determined for each wheel via the torque measuring flanges. With the wheel diameter r _wheel , the measured torque M _{turn, wheel} can be converted into the _wheel- specific force F _{turn, wheel} : $${\mathrm{F.}}_{\mathrm{D.}reH,\mathrm{R.}ad}=\frac{{\mathrm{M.}}_{\mathrm{D.}reH,\mathrm{R.}ad}}{r_{\mathrm{R.}ad}}$$

By subtracting these measured values F _{rotation, wheel} from the flat track result F _{x, wheel} , the rolling resistance of the wheel can also be specifically determined at the same time: $${\mathrm{F.}}_{\mathrm{R.}Ollwiderstand,\mathrm{R.}ad}={\mathrm{F.}}_{x,\mathrm{R.}ad}-{\mathrm{F.}}_{\mathrm{D.}reH,\mathrm{R.}ad}$$

In addition, this construction depicts the wheel load and the axle geometry as in the original installation position in the vehicle. If the vehicle drives the wheels in the test bench, the wheel-specific rolling resistance is measured directly using the torque measurement technology.

Another aspect of the invention relates to a torque detection device with a torque measuring flange, which is arranged between a wheel of a motor vehicle and a wheel hub of a wheel suspension for a motor vehicle, the torque detection device being designed to carry out a method. In particular, the method is carried out by means of the torque detection device.

Yet another aspect of the invention relates to a test stand with at least one wheel of a motor vehicle and with a torque detection device arranged on the wheel according to the preceding aspect. The motor vehicle is designed in particular as a passenger vehicle.

Advantageous embodiments of the method are to be regarded as advantageous embodiments of the torque detection device and the test stand. For this purpose, the torque detection device and the test stand have objective features which enable the method or an advantageous embodiment thereof to be carried out.

Further features of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination, but also in other combinations or on their own.

• 1 eine schematische Querschnittsansicht eines Rads mit einer Ausführungsform einer Drehmomenterfassungsvorrichtung; und
• 2 eine schematische Seitenansicht einer Ausführungsform eines Prüfstands.

The invention will now be explained in more detail using a preferred exemplary embodiment and with reference to the drawings. Show it:

• 1 a schematic cross-sectional view of a wheel with an embodiment of a torque detection device; and
• 2 a schematic side view of an embodiment of a test stand.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

1 shows an embodiment of a wheel in a schematic sectional view 10 of a motor vehicle 12 ( 2 ) with a torque detection device 14th . The torque detection device 14th has a torque measuring flange 16 on which one between the wheel 10 , especially between a rim 18th of the wheel 10 , and a wheel hub 20th a wheel suspension for the motor vehicle 12 is arranged. By means of the torque detection device 14th is in particular a detection of an on the wheel 10 of the motor vehicle 12 Acting torque allows.

In the process of detecting the on the wheel 10 of the motor vehicle 12 acting torque by means of the torque detection device 14th becomes the torque detecting device 14th on the wheel 10 arranged and it is with a movement of the wheel 10 that on the wheel 10 effective torque detected.

It is intended that the torque measuring flange 16 as a detection element of the torque detection device 14th on the wheel hub 20th is arranged and the wheel 10 , especially the rim 18th , on the torque measuring flange 16 is arranged.

Furthermore, it is particularly provided that by means of at least one strain gauge 22nd of the torque measuring flange 16 the torque is recorded.

Furthermore, it is particularly provided that by means of a telemetry device 24 the Torque detection device 14th the torque is detected using a rotor antenna 26th on the torque measuring flange 16 is arranged and a stator antenna 28 on one opposite the torque measuring flange 16 anti-twist arranged retaining element 30th the telemetry device 24 is arranged. In particular, it can be provided that the torque from the rotor antenna 26th to the stator antenna 28 is transmitted.

Furthermore, the wheel 10 a tire 52 on.

2 shows an embodiment of a test stand in a schematic side view 32 by motor vehicle 12 , which in the present embodiment has four wheels 10 having only two wheels 10 are shown in the side view. A respective wheel 10 is a respective torque detecting device 14th assigned.

In particular, it is provided that the torque during a coasting as a movement of the wheel 10 and / or when driving as a movement of the wheel 10 is captured. In particular, this can be done when rolling out the wheel 10 and / or when driving the wheel 10 through a test bench 32 a drive train resistance based on the detected torque by means of an electronic computing device 34 the torque measuring device 14th be determined, in the present embodiment the electronic computing device outside of the torque detection device 14th is arranged, and / or when driving the wheel 10 by the motor vehicle 12 a rolling resistance based on the detected torque by means of the electronic computing device 34 in the test bench 32 is determined.

In particular, on the basis of the determined drive train resistance, a residual braking torque and a wheel hub loss can be determined by means of the electronic computing device 34 to be determined.

In particular, the 2 that by means of the torque measuring flange 16 the torque can be recorded using the torque measuring flange 16 between the wheel hub 20th and the rim 18th is integrated. The data transmission takes place in particular via the telemetry device 24 , which by induction the data from the rotor antenna 26th on the stator antenna 28 transmits. The data is then stored in the electronic computing device 34 further processed. Will the wheels 10 through the test bench 32 are driven via the torque measuring flanges 16 the drive train losses, including residual braking torque and wheel hub losses, per wheel 10 determined. By subtracting these measured values from the measured values of the flat track test bench, the drive train resistance can be separated from the rolling resistance. Drives the motor vehicle 12 the wheels 10 with the torque measuring flanges 16 the rolling resistance of the individual wheels in the test bench 32 measured.

Für eine detaillierte Komponentenentwicklung, zum Beispiel für Reifen 52, Radlager, Getriebe und Bremsen ist eine Trennung des Antriebsstrangwiderstands vom Rollwiderstand notwendig.In particular, it is provided according to the invention that the motor vehicle 12 in the flat belt test bench, which is the test bench 32 corresponds, with its wheels 10 each on a tape unit 36 is arranged and over the tow hook 38 of the motor vehicle 12 at the front and rear of the test bench 32 is fixed. Any tape unit 36 has running drums 40 on which with a coated steel band 42 are connected. The one in the direction of travel 44 front drum 40 is provided with a drive unit. The rear drum 40 serves for belt tension and belt stabilization. Under every wheel 10 there is a pneumatic air bearing 46 , which ensures that the tire contact point and the rolling behavior of the tire 52 similar to how they are on the street. The entire tape unit 36 is additionally through further air bearings 48 mounted friction-free, so that each on force transducers 50 the drag forces F _{x, wheel} , consisting of roll and drive train losses, per wheel 10 can be determined: $${\mathrm{F.}}_{x,\mathrm{R.}ad}={\mathrm{F.}}_{\mathrm{R.}Ollwiderstand,\mathrm{R.}ad}+{\mathrm{F.}}_{\mathrm{A.}ntriebsstranGwiderstand,\mathrm{R.}ad}$$

For detailed component development, for example for tires 52 , Wheel bearings, gears and brakes, it is necessary to separate the drive train resistance from the rolling resistance.

Durch Subtraktion dieser Messwerte F_Dreh,Rad vom Flachbahnergebnis F_x,Rad kann gleichzeitig auch der Rollwiderstand radspezifisch bestimmt werden: $$F_{Rollwiderstand,Rad}=F_{x,Rad}-F_{Dreh,Rad}$$

Darüber hinaus bildet diese Konstruktion die Radlast und die Achsgeometrie wie in der Originaleinbaulage im Kraftfahrzeug 12 ab.The torque measuring flange is used for this 16 on the wheel hub 20th of the motor vehicle 12 pushed and fixed with wheel bolts. The original wheel of the motor vehicle to be measured is then used 12 , which in particular on the rim 18th and the tire 52 can be designed with wheel bolts on the torque measuring flange 16 assembled. Will the motor vehicle 12 through the test bench 32 can be driven via the torque measuring flanges 16 the drive train losses including residual braking torques and wheel hub losses can be determined for each wheel. With the wheel diameter r _wheel , the torque M _{turn, wheel} can be converted into the _wheel- specific force F _{turn, wheel} : $${\mathrm{F.}}_{\mathrm{D.}reH,\mathrm{R.}ad}=\frac{{\mathrm{M.}}_{\mathrm{D.}reG,\mathrm{R.}ad}}{r_{\mathrm{R.}ad}}$$

By subtracting these measured values F _{rotation, wheel} from the flat track result F _{x, wheel} , the rolling resistance can also be determined for each _wheel at the same time: $${\mathrm{F.}}_{\mathrm{R.}Ollwiderstand,\mathrm{R.}ad}={\mathrm{F.}}_{x,\mathrm{R.}ad}-{\mathrm{F.}}_{\mathrm{D.}reH,\mathrm{R.}ad}$$

In addition, this construction forms the wheel load and the axle geometry as in the original installation position in the motor vehicle 12 from.

The data is transmitted in real time, in particular by means of the telemetry device 24 which the data by induction from the rotor antenna 26th , which on the torque measurement flange 16 attached to the stator antenna 28 transmits. The stator antenna 28 is secured against rotation by means of the holding element 30th via the brake caliper screws behind a brake disc 54 ( 1 ) of the wheel 10 fixed. The positioning of the torque measuring flange 16 directly behind the wheel hub 20th leads to a track widening by the thickness of the torque measuring flange 16 .

Drives the motor vehicle 12 the wheels, the wheel-specific rolling resistance is directly measured in the test bench via the torque measurement technology 32 measured.

This enables the motor vehicle 12 can be measured with the original rim and tire set. The torque measuring flange 16 can be used regardless of the tire / rim dimension to be measured. Therefore only one torque measuring flange set is necessary. Furthermore, the torque measurement technology can be quickly installed on a lift without special tools. The torque measurement technology, in other words the method according to the invention, can be used on the test bench 32 , which can be designed as a flat track and roller test stand, as well as on a test track, on which the drive train losses can be recorded. By subtracting the results obtained from the torque measurement technology from the flat track result, the drive train and rolling resistance of the original wheel set can be separated. The camber and wheel load are identical to the original installation position of the wheel 10 on the motor vehicle 12 . In addition, the rolling resistance can be measured on a flat road surface on the flat belt test bench. This means that the rolling behavior and the wheel contact point are similar to those on the road.

This makes it possible overall that the method can be used to provide a torque measurement technology which makes it possible to measure the rolling and drive train resistance of a motor vehicle 12 when the bike is installed 10 to depict and examine more realistically.

List of reference symbols

10

wheel

12

Motor vehicle

14th

Torque detection device

16

Torque measuring flange

18th

rim

20th

wheel hub

22nd

Strain gauges

24

Telemetry device

26th

Rotor antenna

28

Stator antenna

30th

Retaining element

32

test bench

34

electronic computing device

36

Tape unit

38

Tow hook

40

Running drum

42

Steel belt

44

Direction of travel

46

Air bearings

48

another air bearing

50

Force transducers

52

tires

54

Brake disc

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2017/013173 A1 [0003]
• DE 19650477 C1 [0004]

Claims (10)

A method for detecting a torque acting on a wheel (10) of a motor vehicle (12) by means of a torque detection device (14), in which the torque detection device (14) is arranged on the wheel (10) and when the wheel (10) moves the torque acting on the wheel (10) is detected, characterized in that a torque measuring flange (16) is arranged as a detection element of the torque detection device (14) on a wheel hub (20) of a wheel suspension for the motor vehicle (12) and the wheel (10) on the torque measuring flange (16) is arranged. Procedure according to Claim 1 , characterized in that the torque is detected by means of at least one strain gauge (22) of the torque measuring flange (16). Procedure according to Claim 1 , characterized in that the torque is detected as a movement of the wheel (10) when it is coasting and / or as a movement of the wheel (10) when it is driven. Procedure according to Claim 3 , characterized in that when the wheel (10) is coasting and / or when the wheel (10) is driven by a test stand (32), a drive train resistance is determined on the basis of the detected torque by means of an electronic computing device (34) of the torque detection device (14) and / or when driving the wheel (10) by the motor vehicle (12) on the basis of the detected torque, a rolling resistance is determined by means of the electronic computing device (34) in the test stand (32). Procedure according to Claim 4 , characterized in that a residual braking torque and a wheel hub loss are determined by means of the electronic computing device (34) on the basis of the determined drive train resistance. Method according to one of the preceding claims, characterized in that the torque is detected by means of a telemetry device (24) of the torque detection device (14), a rotor antenna (26) being arranged on the torque measuring flange (16) and a stator antenna (28) on one opposite the holding element (30) of the telemetry device (24) arranged in a non-rotatable manner on the torque measuring flange (16). Method according to one of the preceding claims, characterized in that the torque is transmitted from the rotor antenna (26) to the stator antenna (28) by means of induction. Method according to one of the preceding claims, characterized in that the motor vehicle (12) is arranged in a test stand (32) or on a road in order to detect the torque. Torque detection device (14) with a torque measuring flange (16), which is arranged between a wheel (10) of a motor vehicle (12) and a wheel hub (20) of a wheel suspension for the motor vehicle (12), the torque detection device (14) for performing a method after one of the Claims 1 to 8th is trained. Test stand (32) with at least one wheel (10) of a motor vehicle (12) and with a torque detection device (14) arranged on the wheel (10) Claim 9 .

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