Abstract
A chassis dynamometer for motorcycles with a combustion engine, having a mounting unit, at least one fastening unit, an operating unit, a control unit and a roller for recording the peripheral speed of a motorcycle rear wheel is disclosed. The chassis dynamometer has a flow unit a drive unit, a diffuser and an outflow unit arranged downstream of the diffuser in the direction of flow where the diffuser and outflow unit form a flow channel carrying gas in the operating state, wherein the diffuser can be driven by the drive unit, where the control unit controls the drive unit as a function of the peripheral speed of the roller in such a way that a speed of the gas emerging from the outflow unit in the operating state is substantially equal to the peripheral speed at least from a peripheral speed of 150 km/h.
Claims
1. A chassis dynamometer (1) for motorcycles with a combustion engine, having a mounting unit (2), at least one fastening unit (3), an operating unit (4), a control unit (5) and a roller (6) for recording the peripheral speed of a motorcycle rear wheel, wherein the chassis dynamometer (1) has a flow unit (7), which in turn has a drive unit (8), a diffuser (9) and an outflow unit (10) arranged downstream of the diffuser (9) in the direction of flow, wherein the diffuser (9) and outflow unit (10) form a flow channel carrying gas in the operating state, wherein the diffuser (9) can be driven by the drive unit (8), wherein the control unit (5) controls the drive unit (8) as a function of the peripheral speed of the roller (6) in such a way that a speed of the gas emerging from the outflow unit (10) in the operating state is substantially equal to the peripheral speed at least from a peripheral speed of 150 km/h.
2. The chassis dynamometer (1) according to claim 1, characterized in that the flow unit (7) has a filter unit (11) arranged upstream of the diffuser (9) in the direction of flow, wherein the filter unit (11) and/or the outflow unit (10) can be releasably connected to the diffuser (9).
3. The chassis dynamometer (1) according to claim 1, characterized in that the outflow unit (10) has a circular cross section and a length of at least 0.3 m, preferably at least 0.5 m.
4. The chassis dynamometer (1) according to claim 1, characterized in that the outflow unit (10) has a laminar filter (12), wherein the laminar filter (12) is arranged at an end (13) of the outflow unit (10) away from the diffuser (9), wherein the laminar filter (12) or the outflow unit (10) has a curved surface (15) at a gas outlet end (14).
5. The chassis dynamometer (1) according to claim 1, characterized in that at least one seal unit (16) is arranged between the filter unit (11) and diffuser (9) and between the diffuser (9) and outflow unit (10).
6. The chassis dynamometer (1) according to claim 1, characterized in that the control unit (5) has a frequency converter, wherein the frequency converter is calibrated in a range of peripheral speed from 150 km/h to 350 km/h, advantageously from 200 km/h to 300 km/h, particularly advantageously to 250 km/h.
7. The chassis dynamometer (1) according to claim 1, characterized in that the filter unit (11) is formed as a pleated element filter, in particular as a cartridge filter.
8. The chassis dynamometer (1) according to claim 1, characterized in that the flow unit (7) has a positioning unit (17), wherein the positioning unit (17) has a height unit (18) for adjusting the height and a depth unit (19) for adjusting a distance between the flow unit (17) and a motorcycle on the chassis dynamometer in the operating state.
9. A method for the inflow of gas towards a motorcycle with a combustion engine on a chassis dynamometer (1), having the steps: stationary acceleration of a motorcycle on a chassis dynamometer (1) and measurement of the peripheral speed of the rear wheel of the motorcycle; generating a flow of gas towards the motorcycle, wherein the gas is accelerated and compressed such that its speed corresponds to the peripheral speed of the rear wheel.
10. The method according to claim 9, having at least one of the following steps: generating a laminar flow of the inflow gas after the gas has been accelerated and compressed: filtering the gas before the gas is accelerated and compressed; generating control signals for a device for accelerating and compressing the gas and controlling a drive unit (8) for accelerating and compressing a gas as a function of the peripheral speed of the rear wheel; positioning the gas flow in relation to the motorcycle on the chassis dynamometer.
Description
[0024] The invention is outlined in more detail below by means of the figures based on an exemplary embodiment, wherein
[0025] FIG. 1 shows a perspective view of the chassis dynamometer,
[0026] FIG. 2 shows a perspective detail view of the flow unit,
[0027] FIG. 3 shows a sectional view of the diffuser and outflow unit.
[0028] FIG. 1 shows a perspective view of the chassis dynamometer 1, wherein the chassis dynamometer 1 has a mounting unit 2, on which a motorcycle is arranged in a fixed position in the operating state. In order to fix the motorcycle in place, the mounting unit 2 has a fastening unit 3 for holding a front wheel of the motorcycle. Furthermore, the chassis dynamometer 1 has fastening units 3 in the form of fastening rings 20 arranged on the mounting unit 2 and fastening straps 21 arranged thereon, by means of which the motorcycle can be firmly tensioned on the mounting unit 2 in the operating state. Fastening straps 21 are advantageous as these enable any motorcycle to be fixed in place, regardless of its shape or size. The fastening straps 21 can be tensioned between the motorcycle and the mounting unit 2. The mounting unit 2 further has feet 22 for stability, wherein the feet 22 can advantageously be adjusted in height in order to compensate for unevenness on a floor (not illustrated) and thus guarantee stability. The mounting unit 2 is advantageously made of a sheet metal construction, which creates high strength and rigidity, but significantly reduces the weight compared to a solid metal unit. In an operating state, the rear wheel of the motorcycle is on a roller 6, which partly protrudes beyond the mounting unit 2 and the axis of rotation of which is accommodated within the mounting unit 2 in order to simplify the height difference between the front wheel and rear wheel of the motorcycle and the mounting of the motorcycle on the mounting unit 2. An operating unit 4 is also arranged on the mounting unit 2 via an articulated operating arm 23, wherein the operating unit 4 has a plurality of buttons, switches and a display. Independent of the mounting unit 2, two control units 2 and a flow unit 7 are arranged, wherein the flow unit 7 has, in addition to a platform 24, a positioning unit 17, as well as a filter unit 11, a non-visible drive unit 8, a diffuser 9 and an outflow unit 10, wherein the outflow unit 10 is directed at one front of the motorcycle on the chassis dynamometer 1 in the operating state. The diameter of the outflow unit 10 is at least as large as an opening of an airbox of a motorcycle on the chassis dynamometer in the operating state. The flow unit 7 can be adapted to the mounting unit 2 as required and can be used individually due to its independent stand.
[0029] FIG. 2 shows a perspective detail view of the flow unit 7, wherein the platform 24 raises the flow unit 7 to an appropriate base height and the positioning unit 17 has a height unit 18 and a non-visible depth unit 19, wherein the height unit 18 is formed via an X-shaped joint 25 and the angle between the legs of the X-shaped joint 25 and thus the height of the flow unit 7 is adjustable by means of a threaded rod 26. The depth unit 19 is advantageously formed by a non-visible sliding unit, wherein the distance between the flow unit 7 and the motorcycle on the chassis dynamometer 1 in the operating state can thereby be adjusted. On an upper base 27 of the positioning unit 17, the flow unit 7 has the drive unit 8 in the form of an electric motor as well as a rotationally connected and concentrically arranged diffuser 9, on which a filter unit 11 in the form of a cartridge filter is concentrically arranged. Substantially orthogonal to the filter unit 11, an outflow unit 10 is arranged circumferentially on the diffuser 9, wherein the outflow unit 10 has a circular cross section and is arranged on the diffuser 9 via a flange 28. The outflow unit 10 advantageously has a straight length without curves in order to keep the flow loss within the outflow unit 10 as low as possible and minimize turbulent flows. A laminar filter 12 is arranged at one end 13 of the outflow unit 10, wherein said filter 12 has a plurality of passage openings 32 with honeycomb cross sections. At least one non-visible seal unit 16 is respectively arranged between the filter unit 11 and diffuser 9 and between the diffuser 9 and outflow unit 10.
[0030] FIG. 3 shows a sectional view of the diffuser 9 and outflow unit 10, wherein the diffuser 9 has a diffuser housing 29 and a diffuser wheel 30, which has an outwardly increasing cross section between its vanes 31. The distance between the vanes 31 and the diffuser housing 29 should advantageously be selected to be as small as possible in order not to allow dead spaces with regard to the gas flow. After the gas enters centrally via the filter unit 11 (not shown) onto the diffuser wheel 30, it is conveyed outwards by its rotation and finally into the outflow unit 10. The outward expansion of the cross section between the diffuser wheels 30 reduces the gas speed and increases the gas pressure. The outflow unit 10 accommodates the laminar filter 12 at is end 13, wherein said filter 12 has a plurality of passage openings running in the direction of flow of the gas and a curved surface 15 at a housing outlet end 14 to minimize turbulent flows when a gas flow exits the outflow unit 10. The outflow unit 10 is further arranged on the diffuser 9 via a flange 28. Two seal units 16 in the form of sealing rings are respectively arranged between the flange 28 and diffuser 9 as well as between the flange 28 and outflow unit 10. The outflow unit 10 is formed as a metal or plastic pipe and has a circular cross section.
TABLE-US-00001 REFERENCE LIST 1 Chassis dynamometer 2 Mounting unit 3 Fastening unit 4 Operating unit 5 Control unit 6 Roller 7 Flow unit 8 Drive unit 9 Diffuser 10 Outflow unit 11 Filter unit 12 Laminar filter 13 End 14 Housing outlet end 15 Curved surface 16 Seal unit 17 Positioning unit 18 Height unit 19 Depth unit 20 Fastening rings 21 Fastening straps 22 Feet 23 Operating arm 24 Platform 25 Joint 26 Threaded rod 27 Upper base 28 Flange 29 Diffuser housing 30 Diffuser wheel 31 Vane 32 Passage opening
