WO2009050053A1

WO2009050053A1 - Torque measurement flange

Info

Publication number: WO2009050053A1
Application number: PCT/EP2008/063341
Authority: WO
Inventors: Helmut Schneiderbeck
Original assignee: Avl List Gmbh
Priority date: 2007-10-11
Filing date: 2008-10-06
Publication date: 2009-04-23
Also published as: DE112008002696B4; AT9782U2; AT9782U3; DE112008002696A5

Abstract

In order to be able to perform highly dynamic tests using high alternating loads on test fixtures for vehicles or vehicle components, a torsionally stiff, compact shaft-hub connection transmitting high torques is required between the dynamometer and the test object, said connection further integrating a torque measurement. The present invention proposes such a torque measurement flange (4), wherein the connection hub (10) is designed as a tapering recess (16) having a non-circular cross section, such as a convex polygon.

Description

Torque flange

The subject invention relates to a torque flange having a connection flange at a first axial end of the torque-measuring flange and an axially adjoining connection hub at the opposite second axial end of the torque-measuring flange and with an axially extending torque-measuring section therebetween in which a torque-measuring device is arranged, and the use of such a torque-measuring flange in a drive or loading machine and in a test stand for vehicles or vehicle components. On dynamic test stands for specimens such as e.g. Engines, drivetrains, transmissions, or vehicles, the primary objective is to give the device under test those load conditions which, in real use, e.g. when operating a vehicle with a motor or powertrain on the road, occur. The load of the test specimen is usually done with a Eintriebs- or loading machine (power brakes or dynamometer) in the form of electric motors. For this purpose, it is becoming increasingly important to be able to replicate transient or highly dynamic processes reproducibly. With conventional asynchronous electric motors as a dynamometer, one quickly came up against technological limits. With the introduction of powerful permanent magnet synchronous motors with highest power densities and compact dimensions in combination with modern frequency converters and suitable control technology, it is now possible to provide highly dynamic dynamometers, thus enabling high dynamics of the entire test bench. This now makes possible highly dynamic operating states and a high proportion of highly dynamic alternating load, such as, for example, the speed variations or the speed surges in the combustion of an internal combustion engine or the simulation of rotational irregularities or torsional vibrations of a drive train, close to reality.

The connection between the dynamometer and the test object is carried out with special shaft connections, which allow not only the non-rotatable connection but also a torque measurement. The torque sensors, as disclosed, for example, in EP 1 074 826 A2, are arranged between two connecting flanges, which are connected on the one hand to the test specimen and, on the other hand, to the dynamometer. Such a test rig arrangement can be found, for example, in WO 2006/099641 A1. The separate torque sensor but extends the shaft train and it is introduced into the shaft train another mass at some distance from the bearings of the shaft train. But this reduces the bending-critical frequency of the shaft train and it can lead to increased bending vibrations. In addition, the additional mass in the shaft train reduces the maximum permissible speed of the shaft train. Further, by the finite Rigidity of the long shaft and the flexible connecting elements a reliable dynamic torque measurement, especially as this is required for the implementation of dynamic testing tasks, not always possible.

Likewise, compact torque measuring flanges are known, which not only produce the non-rotatable connection between the test specimen and the performance brake, but also have a torque sensor integrated. Such a torque measuring flange is e.g. known from DE 101 06 625 A1. This has a connection flange, with which the torque measuring flange is fastened to the test object, and a connection hub, for connecting the measuring flange to the dynamometer. The connecting hub is pushed without further connecting flange directly to the output shaft of the dynamometer and clamped from the outside by means of special clamping elements on the output shaft, thus achieving a compact shaft strand and the mass of the shaft strand is reduced. For conventional applications, such a frictional clamping connection has been sufficient. For highly dynamic application with high torques and high-frequency alternating loads, however, such a clamp connection is completely unsuitable, since at high load undesirable slippage, non-uniform joint pressure by the clamping and thus wear and deformation of the torque measuring flange, along with an axial Displacement of the connection flange can come. Furthermore, such a clamping connection does not have sufficient torsional rigidity, so that a play and slip-free introduction of high alternating torques is not possible. In addition, the hub braced during clamping no longer reproducible, so the shaft strand is always subject to slightly different conditions after each disassembly and re-assembly. All this means that a torque measurement on the torque measuring flange becomes unreliable or even unusable, especially for highly dynamic applications with high torques and high-frequency alternating loads. In addition, the assembly or disassembly and thus a change of the power brake in such a clamp connection is a very complicated and therefore lengthy process, e.g. because of exactly to be observed assembly process, necessary operating balancing, etc.

It is therefore an object of the subject invention to provide a torque flange, which does not have the above disadvantages and in particular a quick and easy change of the torque measuring flange or the input or loading machine, a slip and play-free introduction of highly dynamic and high Allows torques and ensures high rigidity of the shaft-hub connection.

This object is achieved in that a connection hub as an outgoing from the second axial end of the torque measuring flange and in Direction to the first axial end tapered axial recess is made, wherein the cross section of the recess is non-circular. By such a positive connection by means of non-circular profiles, it is possible even very high torques and especially high-frequency alternating loads play and slip-free transfer. Furthermore, the compact size also achieves a particularly rigid shaft connection with a short overall length and, associated therewith, also an increase in the dynamics of the test bench operation. The integrated torque measurement eliminates the need for a separate test bench component to measure torque, which can increase the critical shaft frequency and maximum possible speed. This results in an accurate and highly dynamic torque measurement. Another particular advantage lies in the simple and rapid change hub, since only the connection hub must be pushed onto the tapered connecting pin, which simultaneously takes place a self-centering of the torque measuring flange. Although positive connections by means of polygonal profiles are basically known from spindle drives of machine tools, see eg EP 294 348 A1 or WO 2004/067213 A1, they are only used there for comparatively low powers. On test benches for highly dynamic testing of vehicles or vehicle components, however, large outputs of more than 100 kW and correspondingly high (alternating) torques are required. For test bench applications, there was previously no suitable, form-fitting and sufficiently torsionally rigid shaft-hub connection with integrated torque measurement. This may be because there was no need for it so far. The highly dynamic testing of vehicles and vehicle components came only with the availability of highly dynamic electric motors and the associated new requirements for the test equipment, such as combustion shock simulation, simulation of the open clutch, tire slip simulation, etc., in recent years. Before that, conventional clamp connections were sufficient. Furthermore, such profiles, in particular polygonal profiles, require a very complex production, which is still acceptable for machine tools where extreme accuracy is required, but has not yet been considered for test bench applications which are also subject to considerable cost pressure.

Quite particularly advantageous, the cross-section of the recess is designed as a convex polygon, since such a profile on the one hand allows a particularly simple and quick release of the shaft-hub connection and on the other hand a particularly rigid and slip-poor connection. If the connection flange is arranged axially spaced from the connection hub by the torque measuring section, the torque measuring section can be the special one Requirements of the mounted thereon torque measuring device can be adjusted without affecting the two connection area. This allows accurate and safer torque measurements. In particular, parasitic effects and influences of the connections on the measurement can be excluded or at least reduced.

The torque measuring section preferably has a smaller outer diameter by a recess on the outer circumferential surface in order to create a defined measuring body for measuring the torques.

For easy and safe protection of the torque measuring section, and arranged thereon torque measuring devices against damage, dirt, etc., this is preferably covered with a cover.

The cover can also be easily used to arrange electronics for the evaluation of the measuring signal of the sensors, thus an extremely compact design is possible. In order to be able to transmit the measurement signals wirelessly, an antenna for transmitting the measurement signals to an evaluation unit can also be arranged in the region of the torque measurement section.

The assembly and disassembly can be carried out particularly easily if an axial recess is provided at the flange-side end of the torque-measuring flange, in which a concentric central screw is arranged. With this central screw, the connecting hub can be very easily connected to the connecting pin of the dynamometer shaft and released again. A further simplification results when a threaded sleeve is arranged on the central screw and a radial shoulder is provided on the threaded sleeve, which rests in a position of the threaded sleeve on the torque measuring flange. By turning the central screw, the connection hub can thus be easily pushed off the connecting pin.

With a radial, projecting into the recess stop pin, which preferably engages in an axial groove on the connecting pin, it can be ensured that the connecting hub, and thus the torque measuring flange, is always pushed in the same position on the connecting pin, whereby an elaborate Betriebswuchtung The Wei- len hub connection can be avoided after re-assembly.

A torque measuring flange according to the invention is particularly advantageously used in conjunction with a drive-in or loading machine for a test stand for vehicles or vehicle components or for a test stand for vehicles or vehicle components. The torque flange is about suitable counterparallel elements connected to the test specimen (or the Prüflingswelle) or on Eintriebs- or loading machine (or the dynamometer shaft).

The subject invention is described below with reference to the schematic, exemplary and non-limiting and advantageous embodiments showing Figures 1 to 3. It shows

1 shows a detail of an engine test bench,

2 shows a cross section through the torque measuring flange according to the invention with connecting pin and

3 shows a three-dimensional representation of the torque measuring flange with connecting pins.

In Fig. 1 is a detail of a test stand 1 for a specimen 2, here e.g. an internal combustion engine, shown. The specimen 2 has a Prüflingswelle 5 with an adjoining Prüflingsanschlussflansch 7, with which the internal combustion engine in reality, e.g. can be connected to the drive train of a vehicle. As the test specimen 2 but also other vehicle components, such. a transmission, powertrain or suspension, etc., or an entire vehicle in question. The test object 2 is subjected to certain operating conditions by means of a drive-in or loading machine 3. The input or loading machine 3 is usually an electric motor, for highly dynamic tests advantageous a permanent magnet synchronous motor. Depending on the type of the test piece 2, the input or loading machine 3 is used as a drive machine, e.g. for transmission or powertrain tests, or loading machine, e.g. for testing engines or vehicles. The dynamometer shaft 6 of the drive or loading machine 3 is rotatably connected to the Prüflingswelle 5, so that on the resulting shaft train torque can be transmitted. The connection between the test piece 2 and drive or loading machine 3 via a torque measuring flange 4 according to the invention, which is rotatably connected via a connecting flange 8 with the Prüflingsanschlussflansch 7 and thus with the Prüflingswelle 5 and a connecting hub 10 with the connecting pin 17 of the dynamometer shaft 6 is connected. The shaft-hub connection according to the invention will be described in detail with reference to Figures 2 and 3.

The torque-measuring flange 4 has at one axial end a connecting flange 8, on which in a known manner distributed over the circumference bores for the passage of connecting screws for connection to the Prüflingsanschlussflansch 7 can be arranged. At the opposite axial end of the torque measuring flange 4, a connection hub 10 is arranged. The connecting hub 10 is essentially formed by a recess 16 extending in the axial direction. This recess 16 tapers from the axial end of the torque-measuring flange 4 in the direction of the connecting flange 8. The depth of the recess 16 and thus also the axial length of the connecting hub 10 is determined essentially by the length of the connecting pin 17 of the dynamometer shaft 6. The cross section of the recess 16 is not circular, but here polygonal with a number of contact surfaces 23, here three contact surfaces 23. Geometrically correct, the cross section shown here is a simple, convex polygon, such as any n-corner (eg a triangle, Square, hexagon, etc.). The corners or axial edges of the polygon can also be rounded or released in the connection. The connecting pin 17 of the dynamometer shaft 6 is made equal to it. The connecting pin 17 is thus designed to taper to the axial end and the cross section of the connecting pin 17 is also executed polygonal with a number of contact surfaces 24. If the connection hub 10 is plugged onto the connecting pin 17, a positive connection results through the contiguous abutment surfaces 23, 24, which is thereby able to play even high alternating moments play and slip-free.

In principle, in addition to convex polygons, other non-circular cross-sectional profiles, and thus other positive connections, in question, such as an oval or elliptical cross section or a serrated profile. In principle, all cross-sections in question, which allow a rotationally fixed, positive connection, in particular non-circular cross-sections with at least one contact surface against rotation. Between connecting flange 8 and connecting hub 10, an axially extending torque-measuring section 20 is provided, through which the connecting flange 8 and the connecting hub 10 are axially spaced. In the exemplary embodiment shown, the torque measuring section 20 is a cylindrical section which is formed by a recess in the outer jacket of the torque measuring flange 4. Arranged on this torque measuring section 20 is a torque measuring device 11, which in this example consists of strain gauges which are arranged on the outer circumferential surface of the torque measuring section 20, preferably distributed regularly over the circumference. The torque measuring section 20 and the torque measuring device 11 are covered by a cover 12. The cover 12 can also contain necessary sensor electronics, eg for conditioning, processing, filtering, amplification, digitization of the sensor signal, etc. In addition, an antenna 13 is provided in the torque measuring section 10 in order to transmit the measuring signals from the rotating measuring section 10. the torque measuring flange 4 wirelessly to a suitable evaluation unit 25, such as a computer or a test bench control to transfer. Of course, however, any other suitable torque-measuring device 1 1 may be provided within the scope of the invention. The material structure on which the torque-measuring device 11 is applied should be as homogeneous as possible. This is easily possible in the region between the connecting hub 10 and the connecting flange 8, for which reason the torque measuring section 20 is preferably arranged between the hub and the flange. In principle, however, it would be with restrictions, such as the inclusion of parasitic, possibly the measurement of disturbing effects, but also possible to arrange the torque measuring device 11 in the region of the connecting hub 10 or the connecting flange 8 - in this case, the connecting hub 10 and the Connecting flange 8 also serve as a torque measuring section 20.

In order to facilitate the assembly and disassembly of the torque-measuring flange 4, a central screw 14 may be provided, which is screwed into a concentric threaded bore 21 in the connecting pin 17. The central screw 14 is arranged in an axial recess 19 at the flange-side end of the torque-measuring flange 4 and held by a threaded sleeve 18 which is screwed into an internal thread on the recess 19 of the torque-measuring flange 4. By turning the central screw 14 clockwise (in a conventional right-hand thread), the central screw 14 is supported on the threaded sleeve 18 and the torque measuring flange 4 is pulled onto the connecting pin 17. By the tapered recess 16 and the tapered connecting pin 17 while an automatic centering of the torque measuring flange 4 takes place on the connecting pin 17. If the central screw 14 is rotated in the opposite direction, then moves the central screw 14, to this the recess 19 of the torque measuring flange 4 is present. If now rotated further, then the torque measuring flange 4 is pushed by the connecting pin 17. This allows a particularly simple and rapid assembly and disassembly of the torque measuring flange 4th

Furthermore, a stop pin 15 may be provided which is inserted radially in the connection hub 10 and projects radially into the recess 16. On the connecting pin 17 in this case in the outer peripheral surface of a corresponding axial end of the outgoing axial groove 22 is incorporated, in which the stop pin 15 engages. This ensures that the torque-measuring flange 4 is always pushed in the same position on the connecting pin 17, whereby a complex operating balancing can be omitted.

Claims

claims

A torque measuring flange having a connecting flange (8) at a first axial end of the torque measuring flange (4) and a connecting hub (10) at the opposite second axial end of the torque measuring flange (4) and arranged therebetween, a axially extending torque-measuring portion (20) on which a torque-measuring device (11) is arranged, characterized in that the connecting hub (10) as a starting from the second axial end and tapering towards the first axial end axial recess ( 16) is executed, wherein the cross section of the recess (16) is designed to form a positive connection non-circular.

2. torque measuring flange according to claim 1, characterized in that the

Cross-section of the recess (16) is designed as a convex polygon.

3. torque measuring flange according to claim 1 or 2, characterized in that the connecting flange (8) through the torque-measuring portion (20) axially spaced from the connecting hub (10) is arranged.

4. torque measuring flange according to claim 3, characterized in that the

Torque measuring section (20) has a smaller outer diameter than the connecting hub (10).

5. torque measuring flange according to one of claims 1 to 4, characterized in that on the outer peripheral surface of the torque-measuring section (20) sensors for measuring the torque, preferably strain gauges are arranged.

6. torque measuring flange according to one of claims 1 to 5, characterized in that the torque-measuring section (20) with a cover (12) is covered.

7. torque measuring flange according to claim 6, characterized in that in the cover (12) electronics for evaluating the measuring signal is arranged.

8. torque measuring flange according to one of claims 1 to 7, characterized marked, that in the region of the torque-measuring section (20) an antenna (13) for transmitting the measuring signals to an evaluation unit (25) is arranged.

9. torque measuring flange according to one of claims 1 to 8, characterized in that at the flange end of the torque measuring flange (4) an axial recess (19) is provided, in which a concentric central screw (14) is arranged.

10. torque measuring flange according to claim 9, characterized in that a threaded sleeve (18) is provided, which is screwed for holding the central screw (14) in an internal thread on the recess (19) of the torque-measuring flange (4).

1 1. torque measuring flange according to one of claims 1 to 10, characterized in that the torque-measuring flange (4) a radial stop pin (15) is provided, which projects radially into the recess (16).

12. Eintriebs- or loading machine for a test stand (1) for vehicles or vehicle components with a dynamometer shaft (6) and a torque measuring flange (4) according to one of claims 1 to 1 1, wherein the dynamometer shaft (6) at an axial End having a connecting pin (17) whose cross-section is non-circular to the cross-section of the recess (16) of the connecting hub (10) of the torque measuring flange (4) and is tapered and the connecting hub (10) form-fitting manner on the connecting pin (17 ) is attached.

13. Eintriebs- or loading machine according to claim 12, characterized in that on the connecting pin (17) has a concentric axial threaded bore (21) for receiving the central screw (14) is provided.

14. Eintriebs- or loading machine according to claim 12 or 13, characterized in that on the connecting pin (17) has an axial groove (22) is provided, into which the stop pin (15) engages.

15. Test bench for vehicles or vehicle components, comprising a test specimen (2) with a test specimen shaft (5) with a specimen connection flange (7) and with a driving or loading machine (3) with a dynamometer shaft (6) and a torque Measuring flange (4) according to one of claims 1 to 1 1, wherein the connecting flange (8) of the torque measuring flange (4) with the Prüflingsanschlussflansch (7) is connected and the dynamometer shaft (6) at one axial end a connecting pin (17) whose cross-section is non-circular in cross section to the cross-section of the recess (16) of the connecting hub (10) of the torque-measuring flange (4) and is tapered and the connecting hub (10) is positively mounted on the connecting pin (17).