Bicycle rim

Abstract

The invention relates to a bicycle rim (4) having an annular rim profile (9) for receiving a tyre casing (8) on the outside, wherein the rim profile (9), together with the tyre casing (8), forms an annular cavity (80) for providing an overpressure region (10), which is provided for filling with a gas (G), and wherein a measuring device (12), provided with a housing (70) and having at least one pressure measuring sensor (13) for determining the pressure (p) in the overpressure region (10), is arranged on the rim profile (9). According to the invention, the housing (70) lies flat with a contact surface (73) adapted to the curvature of the rim profile (9) against the outer contour of the rim profile (9) facing the overpressure region (10).

Description

[0001] bicycle rim

[0002] The invention relates to a bicycle rim with an annular rim profile for the external reception of a tyre casing,

[0003] - wherein the rim profile together with the tyre casing forms an annular cavity for providing an overpressure area which is intended for filling with a gas, and

[0004] - wherein a measuring device provided with a housing and having at least one pressure measuring sensor for determining the pressure in the overpressure range is arranged on the rim profile.

[0005] Pressure sensor systems are currently available for monitoring bicycle tire pressure. These are mounted directly on the tire valve. This directly measures the fluid pressure in the valve area. These systems are retrofit solutions. Due to their valve-mounted design, they are susceptible to mechanical stress, impact, and dirt. The air or media channel, from the valve to the pressure sensor, requires complex sealing. Three seals are required for this alone, which are susceptible to particles and dirt. The correspondingly complex system design therefore results in high costs. Due to the acting pressure of up to 10 bar, additional metallic reinforcements are necessary (metal piston or metal ring including the retaining structure in the plastic housing, etc.).In addition, these are not integrated into the direct mechanics of the wheel, which makes them unsuitable for initial factory equipment or for integration into holistic control systems (tire pressure control) or safety-relevant systems such as ABS.

[0006] Against this background, the invention is based on the object of specifying a bicycle rim with the features described above, which enables a structurally simpler measurement of the tire pressure while riding. According to the invention, this object is achieved in that the housing rests flatly against the outer contour of the rim profile facing the overpressure area with a contact surface adapted to the curvature of the rim profile. According to the invention, the tire pressure measurement is structurally decoupled from the tire valve, thereby enabling a design of the tire pressure measuring system that is completely independent of the valve. Instead, the tire pressure measurement is deliberately integrated into the structural design of the bicycle rim. This allows the tire pressure measuring system to be factory-integrated into the bicycle rim, so that it can, for example, be easily embedded into an electronic assistance system of the bicycle.By adapting the housing to the contour of the rim profile according to the invention, the measuring device can be positioned precisely, enabling very exact recording of the pressure in the overpressure range. For this purpose, the housing expediently has a contour in the area of ​​the support surface that is adapted to the curved outer contour of the rim profile. However, it is also within the scope of the invention in particular that an elastic element is arranged between the housing and the support surface, which ensures that the housing rests flat against the outer contour of the rim profile. This elastic element can be self-adhesive, in particular double-sided self-adhesive. It is also within the scope of the invention in principle for the elastic element to be a component of the housing.

[0007] The bicycle rim can be used on a classic, purely pedal-driven bicycle without motor assistance. However, the bicycle in question can also be a pedelec or an e-bike. The bicycle rim can also be used on pedal-driven three- and four-wheelers (with or without motor assistance), especially those with spokes.

[0008] It is of course within the scope of the invention that a rim strip is arranged on the outer side of the rim profile. This rim strip can advantageously be used to precisely position the housing and thus also the pressure measuring sensor, and thus to improve the quality of the measurement. For example, the housing and / or the elastic element can enclose the rim strip at least partially, or even completely if necessary. In particular, it is within the scope of the invention for the rim strip to be inserted into a first housing part of the housing and then enclosed by the second housing part. However, it is also possible for the rim strip to be pushed into a slot-shaped recess in the housing. Overall, the aforementioned measures ensure an intimate connection between the housing and the rim strip.The connection of the housing to the rim tape can in principle be realized independently of the previously described support surface of the housing, which is adapted to the curvature of the rim profile.

[0009] In particular, it may be expedient for the housing to be attached to the rim strip and / or the rim profile 9, and preferably for at least one attachment projection to be provided for this purpose. The attachment projection can be arranged on the housing or on the elastic element. For this purpose, the attachment projection can extend through an opening in the rim profile and / or the rim strip. The attachment projection expediently has at least one undercut that can engage with the corresponding opening, thereby ensuring attachment.

[0010] There are two main variants for the design of the overpressure zone: tubeless or with a tube. In the tubeless design, the outer side of the rim profile and the inner side of the tire casing jointly delimit the overpressure zone. Accordingly, in this case the pressure measuring sensor is located within the overpressure zone. In the alternative design, a tube delimiting the overpressure zone is arranged within the cavity. In this case, the pressure measuring sensor is expediently located outside the overpressure zone, but rests on the outer side of the tube and can thus indirectly measure the pressure in the overpressure zone. According to a preferred embodiment of the invention, the outward-facing region of the housing is adapted to the curvature of the tube and, for this purpose, has corresponding curves and / or beveled end faces.This allows for a harmonious molding of the outer contour of the housing to the tube, which positively influences the accuracy of the pressure measurement and simultaneously reduces the risk of damage to the tube caused by the housing. In this context, it is also fundamentally within the scope of the invention for the housing to have outwardly curved edges and / or bevels, as seen in the tire cross-section. The pressure sensor is expediently aligned radially to the rim profile.

[0011] The pressure sensor, usually electronic, is a pressure measuring device that converts the directly or indirectly measured physical quantity of pressure (= force per area) into a, preferably electronic, output quantity as a measure of the pressure. The pressure sensor can be designed as an embedded, microelectromechanical sensor using silicon technology, preferably resistive, piezoresistive, or capacitive, or as a film-like strain sensor, force sensor, resistive, piezoresistive, or capacitive sensor, for example, with at least two structures (pixels).

[0012] According to a preferred embodiment of the invention, the measuring device has at least one control and / or communication unit, preferably for wireless transmission of the electronic measurement signal of the pressure measuring sensor and / or for transmission of data pre-processed by the control and / or communication unit to a remote receiving unit, e.g., to a bicycle on-board computer. This sensor-related data processing is relevant with regard to the energy consumption of the measuring device. This is because it enables only comparatively small amounts of data to be transmitted from the measuring device to the outside, e.g., to the bicycle on-board computer, since a significant portion of the data transport takes place within the measuring device itself between the pressure measuring sensor and the control and / or communication unit. The control and / or communication unit is particularly designed to receive sensor signal data, e.g.,analog or digital raw sensor data, buffer storage and, for example, pre-processing and reducing it using sensor data fusion, data filtering, feature extraction, feature selection, and classification. The pre-processed data, with its reduced data volume, can then be made available to the external receiving unit. This protects the power supply unit of the measuring device, in particular, extending its energy service life and also reducing the susceptibility to errors during signal transmission from the pressure sensor to the remote receiving unit. It is also within the scope of the invention for the bicycle on-board computer to use the measurement signals from the pressure sensor to control an ABS system on the bicycle. It is also within the scope of the invention for the measuring device to have an electronic data memory, for example for storing the measurement data from the pressure sensor.

[0013] The measuring device expediently has a replaceable power supply unit (e.g., a battery, e.g., a button cell) for supplying electrical power to the measuring device. It is further within the scope of the invention that the power supply unit contains at least one primary battery, in particular a replaceable one, and / or a secondary battery and / or an energy harvester and / or an energy generator based on the vibration or rotational movement of the bicycle rim and / or structures for wireless energy transmission, in particular for inductive energy transmission or electromagnetic energy transmission, and / or structures for passive pressure detection, in particular by detuning an electromagnetic wave.

[0014] The housing may have an opening area that allows for the replacement of the power supply unit. A removable cover or a sliding housing holder may be provided in this opening area.

[0015] In particular, in addition to the pressure measuring sensor, the measuring device can additionally have a, expediently electronic, control or regulating unit for adapting the pressure in the overpressure range to a target value (e.g. 2.5 bar g) or target value range on the basis of the measurement signal from the pressure sensor. It is also within the scope of the invention for this control or regulating unit to be designed as a component of the at least one control and / or communication unit. The corresponding control or regulating signal can be transmitted, for example, to a bicycle on-board computer or directly to a co-rotating compressed gas container (e.g. mounted on the wheel hub), which can process electronic signals. In this case, the measurement signal from the pressure measuring sensor is transmitted via a transmitter wirelessly or, preferably, directly by wire to the nearby, in particular immediately adjacent, control or regulating unit.The measured signal is transmitted to a control unit, which uses this measurement signal as an input for the control or regulation. The pressure sensor can be foil-shaped.

[0016] The measuring device can also in principle contain further components, e.g. at least one further pressure sensor and / or at least one temperature sensor and / or at least one acceleration sensor and / or at least one yaw rate sensor and / or at least one wheel speed sensor and / or at least one vibration sensor and / or at least one microphone and / or at least one Hall sensor and / or at least one magnetic field sensor.

[0017] The rim profile itself can be designed as a hollow chamber profile or as a box rim profile. In a hollow chamber profile, the rim profile has a circular hollow chamber with a hub-side and a shell-side wall.

[0018] The invention is explained in detail below with reference to a drawing that merely represents an exemplary embodiment. The drawing schematically shows: Fig. 1: a bicycle with a bicycle rim according to the invention;

[0019] Fig. 2: section a in Fig. 1;

[0020] Fig. 3: the section A - A in Fig. 2,

[0021] Fig. 3a: view X in Fig. 3;

[0022] Fig. 4,5: further embodiments of the invention in a representation corresponding to Fig. 3a and

[0023] Fig. 6-8: further embodiments of the invention in a representation corresponding to Fig. 3 (sections)

[0024] Fig. 1 shows a bicycle 1 with a bicycle frame 2 and two wheels 3 as well as a saddle 25 and handlebars 30, wherein the wheels 3 each have a tire 5 mounted on a bicycle rim 4 and filled with compressed gas G. The illustrated bicycle 1 is designed as a pedal-driven pedelec and is accordingly equipped with rider assistance in the form of an electric motor 6, which is powered by a battery 7.The wheels 3 each have a wheel hub 40, which enables a rotational movement of the corresponding wheel 3 around the two wheel axes of the bicycle 1, and spokes 50 (indicated only in the case of the front wheel 3), which are arranged between the bicycle rim 4 and the wheel hub 40 and each connect the bicycle rim 4 to the wheel hub 40. Figure 1 further shows that the bicycle 1 has an on-board bicycle computer 55 mounted on the handlebar 30 with a display (not shown in detail) which shows, for example, the speed of the bicycle 1, the range of the battery 7, etc. Figure 2 shows an enlarged section of the front wheel 3 with the bicycle rim 4 and a tire 8.

[0025] As can be seen from the cross-sectional view according to Fig. 3 in conjunction with Figs. 1, 2, the bicycle rim 4 has a closed annular rim profile 9 for receiving the tire casing 8 on the outside. The rim profile 9, together with the tire casing 8, forms an annular cavity 80 for providing a closed annular overpressure region 10 filled with the compressed gas G. The rim profile 9 also has a conventional opening (not shown in detail) aligned radially to the rim profile 9 for receiving a valve 11 (Fig. 1) for filling the overpressure region 10 of the tire 5 with the compressed gas G.

[0026] As can be seen from the figures, an electronic measuring device 12 with an electronic pressure measuring sensor 13 for determining the pressure p in the overpressure region 10 resulting from the filling of the tire 5 with the compressed gas G is arranged on the rim profile 9. The measuring device 12 is equipped with a housing 70. The housing 70 serves to accommodate the components of the measuring device 12 and is therefore useful both for mechanical reasons (protection of the components against damage) and for optical reasons. In the embodiment according to Fig. 3, the rim profile 13 is designed as a hollow chamber profile. In this case, the rim profile 9 accordingly has an annular hollow chamber 15 with a hub-side wall 16 and a shell-side wall 17. The pressure measuring sensor 13 is aligned radially to the rim profile 9 and arranged in the outer region of the rim profile 9 facing the overpressure region 10.In the exemplary embodiment, the outer edge of the rim profile 9, referred to as the rim flange 18, protrudes radially from the outer edge of the pressure measuring sensor 13, wherein this radial distance s is at least 0.1 mm and preferably in the range 0.1 mm to 8 mm. As can be seen from Fig. 3a, the measuring device 12 has an electronic control and communication unit 19 for the wireless transmission of the measurement signal of the pressure measuring sensor 13 and the data pre-processed by the control and communication unit 19 to the bicycle on-board computer 55 and a power supply unit 20 in the form of an electric battery (e.g. in the form of a button cell) for the wireless (or alternatively also wired) electrical power supply of the pressure measuring sensor 13 and the control and communication unit 19. The housing 70 of the measuring device 12 is designed in several parts.It has an opening area 71 that allows for replacement of the power supply unit 20. In this embodiment, a removable cover 72 is provided in this opening area 71, which is first disassembled and then reassembled after replacement.

[0027] Alternatively, a sliding holder, for example, can be provided for this purpose. Fig. 3a also shows that the housing 70 rests flatly with a support surface 73 adapted to the circular curvature of the rim profile 9 against the outer contour of the rim profile 9 facing the overpressure region 10 - in this case the shell-side wall 17. For this purpose, the housing 70 has, in the region of the support surface 73, a contour adapted to the circularly curved outer contour of the rim profile 9 with the radius of curvature r. Furthermore, an elastic element 74 is arranged between the housing 70 and the support surface 73, which also ensures that the housing 70 rests flatly against the outer contour of the rim profile 9. The elastic element 74 consists, for example, of a rubber material and is adhesive on both sides, so that the housing 70 is attached to the rim profile 9.

[0028] The control and communication unit 19 is designed in such a way that it can temporarily store sensor signal data, in particular analog or digital raw sensor data, and pre-process and reduce it, for example by means of sensor data fusion, data filtering, feature extraction, feature selection, and classification. This pre-processed data, with its reduced data volume, can then be transmitted wirelessly to the bicycle on-board computer 55. The measurement signal from the pressure sensor 13 is transmitted via a line (not shown) to the nearby control and communication unit 19, which uses this measurement signal as an input variable. Measurement signals recorded within a specific time interval can be summed and used as a time-averaged measurement signal for control. This sensor-related data processing is relevant in this regard.the energy consumption of the electronic components of the measuring device 12, i.e. of the pressure measuring sensor 13 and the control and communication unit 19. The unit 19 then sends a data signal on the basis of the measured data at comparatively long intervals, for example to the bicycle on-board computer 55, or also directly control signals to an electronically controllable compressed gas container with compressed gas G (not shown), which can be arranged, for example, in the co-rotating hub 40 and, for example, fills the overpressure area 10 with compressed gas G in accordance with the control signal in order to compensate for a pressure drop in the tire 5 determined by the pressure measuring sensor 13. The communication unit 19 also has an electronic data memory in which, for example, the measured data determined by the pressure measuring sensor 13 can be saved.

[0029] It can also be seen from Fig. 3 that a hose 21 delimiting the overpressure region 10 is arranged within the cavity 80. Accordingly, the pressure measuring sensor 13 is located outside the overpressure region 10, but rests on the outside of the hose 21 and can thereby indirectly measure the pressure p in the overpressure region 10. Fig. 3a shows that the outwardly directed region of the housing 70 is adapted to the annular curvature of the hose 21 and has rounded corners 70' for this purpose. In the embodiment according to Fig. 4, a fastening projection 75 is provided for fastening the housing 70 to the rim profile 9, which fastening projection is arranged on the elastic element 74. This fastening projection 75 has an undercut 76 so that it can engage with an opening 77 in the rim profile 9. Alternatively, the fastening projection 75 can also be arranged on the housing 70 itself.

[0030] In the embodiment according to Fig. 5, end-side bevels 70" are provided for the external geometric adaptation of the housing 70 to the annular curvature of the tube 21, ie, bevels extending along the wheel circumference. These bevels enclose the angle a with the local tangent T of the circumferential rim profile 9, which angle can be in the range of 30° to 60°, for example.

[0031] 6 to 8 show the measuring device 12 in a representation corresponding to Fig. 3 in isolation. In all of these embodiments, a rim band 22 is arranged on the outer side of the rim profile 9, wherein the housing 70 of the measuring device 12 or the elastic element 74 encloses the rim band 22 at least in part. In Figs. 6 to 8 (as well as in Fig. 3), the housing 70 has lateral rounded portions 85 as seen in the tire cross-section. In the embodiment according to Fig. 6, the elastic element 74 has a lateral recess 78, for example in the form of a slot, into which the corresponding section of the rim band 22 has been inserted laterally. The rim band 22 can be clamped in the recess 78 or can also be connected in this recess 78 in a material-locking manner (e.g. with an adhesive) to the elastic element 74.

[0032] 7 and 8, the elastic element 74 is a component of the housing 70, with which the housing 70 rests on the rim profile 9 (not shown here). According to Fig. 7, the elastic element 74 forms a lower housing half which, together with a corresponding upper half of the housing 70, completely encloses the rim strip 22 in the region of the housing 70. As a result, the housing 70 can be clamped firmly to the rim strip 22, although here too a material connection, e.g. by means of an adhesive (not shown in detail), lies within the scope of the invention. The upper half of the housing 70 is connected via a snap-in connection 79 to the elastic element 74 forming the underside of the housing 70. Fig. 8, the rim strip 22 is also completely enclosed by the housing 70 in the region of the housing 70 and at the same time is positively connected to the housing 70.For this purpose, the rim band 22 has an opening 22' through which a fastening projection 75' arranged on the upper half of the housing 70 passes. The fastening projection 75' then engages with the elastic element 74 forming the underside of the housing.

[0033] The bicycle rim according to the invention can be used on a classic, purely pedal-driven bicycle without motor assistance. However, the bicycle in question can also be a pedelec or an e-bike. The bicycle rim can also be used on pedal-driven three- and four-wheelers (with or without motor assistance), especially those with spokes.

[0034] Protection claims

Claims

Patent claims 1. Bicycle rim (4) with an annular rim profile (9) for the external reception of a tyre casing (8), - wherein the rim profile (9) together with the tyre casing (8) forms an annular cavity (80) for providing an overpressure area (10) which is intended for filling with a gas (G), and - wherein a measuring device (12) provided with a housing (70) and having at least one pressure measuring sensor (13) for determining the pressure (p) in the overpressure region (10) is arranged on the rim profile (9), characterized in that the housing (70) rests flatly with a support surface (73) adapted to the curvature of the rim profile (9) on the outer contour of the rim profile (9) facing the overpressure region (10).

2. Bicycle rim (4) according to claim 1, characterized in that the housing (70) in the region of the support surface (73) has a contour adapted to the curved outer contour of the rim profile (9).

3. Bicycle rim (4) according to claim 1 or 2, characterized in that an elastic element (74) is arranged between the housing (70) and the support surface, which ensures the flat contact of the housing with the outer contour of the rim profile (9).

4. Bicycle rim (4) according to one of claims 1 to 3, characterized in that a rim band (22) is arranged on the outer side of the rim profile (9).

5. Bicycle rim (4) according to claim 4, characterized in that the housing (70) and / or the elastic element (74) completely encloses the rim band (22) at least in some areas, for example in the area of ​​the housing (70).

6. Bicycle rim according to one of claims 1 to 5, characterized in that the housing (70) is fastened to the rim band (22) and / or to the rim profile (9) and preferably at least one fastening projection (75, 75') is provided for this purpose.

7. Bicycle rim (4) according to one of claims 1 to 6, characterized in that the outer side of the rim profile (9) and the inner side of the tire casing (8) together delimit the overpressure area (10).

8. Bicycle rim (4) according to one of claims 1 to 7, characterized in that a hose (21) delimiting the overpressure region (10) is arranged within the cavity (80).

9. Bicycle rim (4) according to claim 8, characterized in that the outwardly directed region of the housing (70) is adapted to the curvature of the tube (21), in particular has radii and / or beveled end faces.

10. Bicycle rim (4) according to one of claims 1 to 9, characterized in that the measuring device (12) has at least one control and / or communication unit (19), preferably for the wireless transmission of the measuring signal of the pressure measuring sensor (13) and / or for the transmission of data pre-processed by the control and / or communication unit (19) to a remote receiving unit (55), and / or an exchangeable energy supply unit (20) for the particular electrical energy supply of the measuring device (12).

11. Bicycle rim according to claim 10, characterized in that the housing (70) has an opening area which enables replacement of the power supply unit (20).

12. Bicycle rim (4) according to one of claims 1 to 11, characterized in that the measuring device (12) in addition to the pressure measuring sensor (13) additionally has a control or regulating unit for adapting the pressure (p) in the overpressure range (10) based on the measurement signal of the pressure measuring sensor (13) to a desired value or desired value range or this control or regulating unit is designed as a component of the at least one control and / or communication unit (19).

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