Air spring, preferably for cargo bikes

Abstract

The invention relates to an air spring (2), preferably for cargo bikes (1), having a piston (20), a cover (22) or a flanged plate (22), and a bellows (21) which is situated between the piston (20) and the cover (22) or the flanged plate (22) and is designed to be filled with compressed air; at least one permanent magnet (24) which is secured to the piston (20) within the bellows (21); and at least one sensor (25) which is mounted, opposite the permanent magnet (24), so as to be movable together with the cover (22) or the flanged plate (22). The air spring (2) is characterized in that the sensor (25) is situated outside of the bellows (21).

Description

[0001] 202405748 1

[0002] Description

[0003] Air spring, preferably for cargo bikes

[0004] The present invention relates to an air spring, preferably for cargo bikes.

[0005] Bicycles have long been used worldwide for transporting people and goods. They are typically two-wheeled and propelled by the rider's muscle power. Bicycles powered by an electric motor are also available; these are known as e-bikes.

[0006] To transport larger quantities of goods, such as mail, packages, and the like, or at least one additional person who isn't contributing to the movement, larger bicycles are known as cargo bikes or freight bikes. Terms like transport bike or cargo bike are also common. Cargo bikes with electric drive are called electric cargo bikes. This refers to a bicycle or a vehicle equivalent to a bicycle, designed for transporting goods or people. Depending on their purpose and intended use, they are equipped with various attachments and superstructures.

[0007] DE 102021 116 326 B3 describes a cargo bike with a base-mounted stiffening frame. The stiffening frame has a cross member and a central beam, the latter being located at the front of the cargo bike. Two wheel carriers of the stiffening frame run parallel to the central beam. Each of the two wheel carriers has its own hub motor arranged between the side walls of a wheel carrier. This makes the stiffening frame more torsionally rigid. The hub motor forms a connection between the side walls. If such a cargo bike with a base-mounted stiffening frame is to be manufactured, the relative torsional rigidity of two wheel carriers of the frame to each other is achieved through inherent stiffness provided by a drive motor, e.g., a hub motor, arranged in one of the wheel carriers.

[0008] DE 102017005699 B3 describes a cargo bicycle with a frame and at least three wheels, wherein at least two wheels are designed as side wheels spaced apart from each other in one direction transversely to a direction of travel of the cargo bicycle, wherein the cargo bicycle has a loading area. The cargo bicycle has two side supports spaced apart from each other transversely to the direction of travel, which laterally define a loading area with an opening for insertion of a transport box, and which form the loading area between them with an opening for insertion of a transport box, as well as a transport system comprising the cargo bicycle and a transport box that can be inserted into the loading area.

[0009] DE 102019 121 141 A1 describes a cargo bicycle that can be propelled by muscle power and / or by an electric drive, with at least one receiving area in or on which at least one interchangeable container and / or an additional load can be arranged or is arranged, and with at least one rider area that is arranged in front of the receiving area with respect to the direction of travel of the cargo bicycle and that comprises at least one seat unit, one pedal unit, one steering unit, a roof element that at least partially covers the rider area and a floor element of a floor unit that at least partially delimits the rider area towards the road surface, wherein the floor element and the roof element have a distance from each other at least partially that is at least the height of an operator. 202405748 3

[0010] In any case, such cargo bikes have so far either been equipped with steel spring hydraulic dampers or have no suspension at all.

[0011] In comparatively larger vehicles, such as trucks or buses, suspension systems are used to dampen vibrations. These include air suspensions, which utilize the compressibility of gases, and especially air.

[0012] A common type of air suspension is the constant-volume air spring in its standard position. In this case, the air is typically enclosed in a rolling diaphragm, which is airtightly connected to other fittings, such as a cover or flanged plate and a rolling piston in road vehicles. The piston is connected to the lower end of the rolling diaphragm and, usually, to an axle in road vehicles or to the chassis in rail vehicles. The upper end of the rolling diaphragm is connected to a cover or flanged plate, which is attached to the vehicle body or chassis. In rail vehicles, the diaphragm is positioned between a sliding plate at the top and the piston at the bottom.

[0013] The rolling diaphragm is fitted over the piston and rolls along it under pressure. The air spring can be supplied with compressed air by a compressor, so that air can be pumped in or out depending on the load in order to keep the filling volume and thus the level of the vehicle constant.

[0014] Such air springs are used in various types of vehicles, especially road vehicles such as trucks, trailers and buses, as well as rail vehicles.

[0015] The operation of air springs requires the ability to control the compressed air mass within the springs. During load changes, this compressed air must either be added to or released from the air springs to maintain the spring's height. 202405748 4

[0016] For this purpose, it is necessary to sensorily detect the height inside the piston of the air suspension or air spring so that the air volume inside the piston can be controlled as a manipulated variable based on this information as the control variable in the control loop. This allows for the implementation of a control loop for automatic height control of the air suspension, which can be used, for example, in a commercial cargo bike.

[0017] To sensorially detect the height inside the piston of the air suspension or the air spring, it is known to use an array of Hall effect sensors in addition to fixed permanent magnets, both of which are located inside the piston of the air spring.

[0018] JP S 62 232501 A describes how, for example, in an air suspension system, a permanent magnet is fixedly attached to the cylinder of a shock absorber inside the bellows, and a sensor opposite the permanent magnet is also attached inside the bellows to the cylindrical part of an outer shell and is movable with the outer shell. Several Hall elements with the same gain are embedded in or glued and attached to an element holder, which extends at equal intervals in the upward and downward directions and is sequentially connected to a maximum value detection circuit and comparator circuits. A comparator circuit assesses whether the output voltage of each Hall element is greater than the reference voltage when the magnet is moved relative to the upward or downward direction, and only generates a height assessment signal if this output voltage is greater than the reference voltage.This method allows for the maintenance of high measurement accuracy over a long period without contamination from oxidation. 202405748 5.

[0019] The operation of the automatic height control is already described in KR 10-0418616 B1, which relates to an electronic control device for an air spring for a motor vehicle and, in particular, to a vehicle suspension system that supplies air filled in an air tank to the airbags of each air spring installed on the front, rear, left, and right wheel side in response to an increase or decrease in a loaded cargo or passengers, so that the vehicle height is kept constant, wherein solenoid valves for supplying and releasing air are each installed on a pipe connecting the air tank and the airbags of the front, rear, left, and right air springs, and a displacement sensor, which detects a tiny amount of displacement as voltage, is installed in each airbag, and a control unit,which compares the output signal of the displacement sensor with a standard value of the air spring and generates an on or off signal for the corresponding air supply and release solenoid valves according to the result, is installed between the displacement sensor and the air supply and release solenoid valve, so that not only can driving comfort and stability be significantly improved, but also the reliability of the vehicle's suspension system itself can be significantly improved.

[0020] Among the disadvantages of state-of-the-art solutions is the potential for leakage of Hall-effect sensors inside the bellows or piston of the air spring due to their mounting and wiring. Furthermore, the installation and removal of these sensors is difficult for this reason. This also applies to sensor replacement in case of malfunction, damage, or failure. Additionally, a single magnet can cause malfunctions if it is not aligned with the sensors due to rotation or slippage during operation.

[0021] One object of the present invention is to improve the sensory detection of the height of the piston of an air suspension or of the air spring itself. 202405748 6

[0022] This should be achieved in particular through automatic height control of the air suspension, preferably for use in a commercial cargo bike. Ideally, this should be as simple, cost-effective, space-saving, weight-saving, and / or flexible as possible. At the very least, an alternative to existing solutions should be provided.

[0023] The problem is solved according to the invention by an air spring and a cargo wheel with the features of the independent claims. Advantageous embodiments are described in the dependent claims.

[0024] The present invention thus relates to an air spring, preferably for cargo bikes, comprising a piston, a cap or flange plate, and a bellows which is arranged between the piston and the cap or flange plate and is designed to be filled with compressed air, with at least one permanent magnet which is fixedly arranged on the piston within the bellows, and with at least one sensor which is movably arranged opposite the permanent magnet with the cap or flange plate. Such an air spring is known, for example, from JP S 62232501 A.

[0025] The air spring according to the invention is characterized in that the sensor is arranged outside the bellows.

[0026] This makes the sensor more easily accessible, which can facilitate installation, repair, or replacement. In other words, an externally mounted sensor is significantly easier to access, or even accessible at all, after installation, and this design can improve accessibility during installation. 202405748 7

[0027] It is also advantageous that the sealing of the bellows can be improved or facilitated as a result, since a passage into the interior of the bellows for the purpose of wiring a sensor located there can be dispensed with.

[0028] Furthermore, it is advantageous that implementing a misalignment protection between the permanent magnet and the sensor can ensure the magnetic coupling between them.

[0029] According to one aspect of the invention, the lid or the crimp plate is fixedly connected to a housing, wherein the housing together with the bellows is designed to be supplied with compressed air, and the sensor is arranged on the outside of the housing.

[0030] This could represent a concrete implementation option. In particular, the sensor can be attached to a rigid body as a housing in this way, which can improve or ensure the desired alignment of the sensor with the permanent magnet.

[0031] According to a further aspect of the invention, the housing has a paramagnetic or non-magnetic material, preferably aluminium, at least where the sensor is arranged, preferably consists of a paramagnetic or non-magnetic material, preferably aluminium.

[0032] This can ensure or promote the presence of a magnetic flux from the permanent magnet to the sensor, and especially to Hall effect sensors, in order to detect the permanent magnet.

[0033] According to a further aspect of the invention, the permanent magnet (24) is ring-shaped. The ring shape lies in the plane that is aligned parallel to the piston and the cover or crimp plate. 202405748 8

[0034] This has the advantage that the sensor works with any rotation of the piston, i.e. the sensor can always detect a section of the ring-shaped permanent magnet, regardless of the orientation of the piston relative to the sensor around the longitudinal axis of the air spring.

[0035] According to a further aspect of the invention, the air spring further comprises a cylinder which is fixedly arranged on the piston and extends through the bellows and the cover or the flange plate, wherein the permanent magnet is fixedly arranged on the cylinder.

[0036] This could represent a concrete possibility for implementation.

[0037] According to another aspect of the invention, exactly one permanent magnet is arranged in a fixed position inside the bellows, preferably on the cylinder.

[0038] This can enable implementation as described above while simultaneously minimizing effort, costs, installation space and / or weight.

[0039] According to another aspect of the invention, the sensor is a sensor array which extends along a direction of relative movement between the piston and the cover or crimp plate.

[0040] This can facilitate the detection of the permanent magnet or improve the accuracy of the detection or determination of the height.

[0041] According to another aspect of the invention, the sensor array is a Hall effect sensor array.

[0042] This could represent a concrete implementation option. 202405748 9

[0043] According to a further aspect of the invention, the sensor, preferably a sensor array, is arranged on a printed circuit board, wherein the printed circuit board is arranged to move together with the cover or with the crimp plate, preferably with a housing.

[0044] This can represent a concrete implementation possibility. The geometry of the printed circuit board and the cover or crimp plate or its housing can ensure the correct alignment of the system.

[0045] The circuit board can be electrically connected to a control unit of the air spring, which reads the height data in order to use it for adjusting the height of the air spring by a higher control unit, for example a cargo bike, according to the user-defined setting.

[0046] According to a further aspect of the invention, the air spring also has a control unit which is configured to operate the sensor, to determine the height of the air spring along a direction of the relative movement between piston and cover or flange plate on the basis of the detected sensor values ​​and to output the determined height.

[0047] This could represent a concrete way of implementing the air spring height as sensor-acquired information and, for example, make it available for height control of the air spring.

[0048] The present invention also relates to a cargo bike with a chassis having at least two wheels and a frame which are resiliently connected to one another by means of at least one air spring as described above, with an air supply unit which is designed and configured to supply the air spring with compressed air, and with a control unit which is designed to regulate the air spring to a predetermined height based on its sensor-detected height. 202405748 10

[0049] Thus, a height of the air spring determined according to the invention can be used by a control unit of the load wheel to regulate the height of the air spring. The compressed air supply can be provided by means of a compressor and / or by means of a compressed air reservoir to supply and operate the at least one air spring.

[0050] According to one aspect of the invention, the chassis has at least three wheels, and the chassis and the frame are flexibly connected to each other by at least two air springs. This can enable the application of the invention to such a cargo bike.

[0051] In any case, the cargo bike can have a system of compressor and valves designed to control the air mass in the air spring by inflating and deflating it. The system can be designed to be powered by electrical energy from the cargo bike and connected to the pneumatic lines for the air springs.

[0052] Air suspension on cargo bikes offers fundamental advantages over conventional steel spring hydraulic damping. For example, a constant ride height or adjustable spring height can be achieved by lowering or raising the bike. Comfort can be increased due to the load-adaptive suspension and damping characteristics. At the same time, friction can be minimized, resulting in improved NVH (Noise, Vibration, Harshness) characteristics in terms of responsiveness and frequency-selective damping.

[0053] This results in several advantages for the application. For example, the significantly improved comfort level allows for a reduction in peak loads on the vehicle structure, cargo, and driver. The resulting comfort benefits also allow for the use of tires with less comfort and therefore better resistance characteristics (e.g., 202405748 11). In some cases, the vehicle structure can be designed to be less robust, and therefore lighter or more cost-effective.

[0054] The adjustable suspension height with lowering and lifting function eliminates the need for carrying loading ramps for container handling, or allows for the use of shorter ramps. This saves costs, weight, and installation space while simultaneously simplifying container handling.

[0055] An exemplary embodiment and further advantages of the invention are explained below in connection with the following figures. These show:

[0056] Fig. 1 shows a perspective schematic representation of a cargo bike according to the invention;

[0057] Fig. 2 is a perspective schematic representation of an air spring according to the invention of the cargo wheel according to the invention of Fig. 1;

[0058] Fig. 3 shows a perspective schematic representation of two air springs according to the invention of the cargo bike according to the invention of Fig. 1; and

[0059] Fig. 4 shows a schematic sectional view of an air spring according to the invention as a longitudinal section.

[0060] Fig. 1 shows a perspective schematic representation of a cargo bike 1 according to the invention. Fig. 2 shows a perspective schematic representation of an air spring 2 according to the invention of the cargo bike 1 according to the invention of Fig. 1. Fig. 3 shows a perspective schematic representation of two air springs 2 according to the invention of the cargo bike 1 according to the invention of Fig. 1.

[0061] The cargo bike 1 according to the invention can also be referred to as a cargo bicycle 1. The cargo bike 1 has a chassis 10 with four wheels 11. The cargo bike 1 further has a chassis 12, which can also be referred to as a body 202405748 12

[0062] The chassis 12 can be referred to as the frame 12 or the chassis 12. The chassis 12 is flexibly mounted on the chassis 10 by means of two air springs 2.

[0063] The air springs 2 are each connected to an air supply unit (not shown) by means of an air supply 13 in the form of an air line 13 in order to be supplied with compressed air by means of the air supply unit.

[0064] Fig. 4 shows a schematic sectional view of an air spring 2 according to the invention as a longitudinal section.

[0065] The air spring 2 according to the invention has a piston 20 as a rolling piston 20, which is connected to the wheels 11 of the cargo wheel 1. The air spring 2 according to the invention also has a flanged plate 22, which is connected to the chassis 10 of the cargo wheel 1. A bellows 21 as a rolling bellows 21 is arranged between them, which, together with the piston 20, the flanged plate 22 and a housing 23, forms a closed volume that can be filled with compressed air via the corresponding air duct 13. Compressed air can also be drawn from the volume of the air spring 2 via the air duct 13. The housing 23 is made of aluminum as a paramagnetic material.

[0066] Within the air spring 2, a cylinder 27 is also fixedly arranged on the piston 20, which extends through the bellows 21 and the flange plate 22 and serves to guide the lowering or raising relative movement between piston 20 and flange plate 22.

[0067] For sensory detection of the height of the air spring 2 along direction A of the relative movement between piston 20 and flange plate 22, exactly one ring-shaped permanent magnet 24 is fixedly arranged inside the bellows 21 on the cylinder 27. Also, exactly one sensor 25 is positioned along the 202405748 13

[0068] A Hall-effect sensor array 25, extending in direction A of the relative movement between piston 20 and crimp plate 22, is arranged opposite the permanent magnet 24 and is movable together with the crimp plate 22. The Hall-effect sensor array 25 is arranged on a printed circuit board outside the bellows 21, the printed circuit board being movable together with the housing 23.

[0069] The air spring 2 according to the invention further comprises a control unit 26, which is configured to operate the Hall-effect sensor array 25, to determine the height of the air spring 2 along a direction A of the relative movement between piston 20 and flange plate 22 based on the detected sensor values, and to output the determined height. The determined height of the air spring 2 can then be used by a control unit (not shown) of the load wheel 1 to regulate the air spring 2 to a predetermined height based on its sensor-detected height.

[0070] 202405748 14

[0071] Reference symbol list (part of the description)

[0072] A Direction of the relative movement between piston 20 and cover 22 or flange plate 22

[0073] 1 cargo bike; cargo bicycle

[0074] 10 chassis

[0075] 11 wheels

[0076] 12 Chassis; body; frame; chassis

[0077] 13 Air supply; air duct

[0078] 2 air springs

[0079] 20 pistons or rolling pistons of the air spring 2

[0080] 21 Bellows or rolling bellows of the air spring 2

[0081] 22 Cover or crimp plate of the air spring 2

[0082] 23 Housing of the air spring 2

[0083] 24 Permanent magnet of the air spring 2

[0084] 25 Sensor or Hall effect sensor array of the air spring 2

[0085] 26 Control unit of the air spring 2

[0086] 27 cylinders of the air spring 2

Claims

202405748 15 Patent claims 1. Air spring (2), preferably for cargo bikes (1), with a piston (20), a cover (22) or a flange plate (22) and a bellows (21) which is located between the piston (20) and the cover (22) or The crimp plate (22) is arranged and designed to be filled with compressed air, with at least one permanent magnet (24) which is fixedly arranged on the piston (20) inside the bellows (21), and with at least one sensor (25) which is arranged opposite the permanent magnet (24) so ​​as to move together with the cover (22) or with the crimp plate (22), characterized in that the sensor (25) is arranged outside the bellows (21).

2. Air spring (2) according to claim 1, wherein the cover (22) or the crimp plate (22) is fixedly connected to a housing (23), wherein the housing (23) together with the bellows (21) is designed to be filled with compressed air, wherein the sensor (25) is arranged on the outside of the housing (23).

3. Air spring (2) according to claim 2, wherein the housing (23) has a paramagnetic or non-magnetic material, preferably aluminium, at least where the sensor (25) is arranged, preferably consists of a paramagnetic or non-magnetic material, preferably aluminium.

4. Air spring (2) according to one of the preceding claims, wherein the permanent magnet (24) is ring-shaped. 202405748 16 5. Air spring (2) according to one of the preceding claims, further comprising a cylinder (27) which is fixedly arranged on the piston (20) and extends through the bellows (21) and the cover (22) or the flange plate (22), wherein the permanent magnet (24) is fixedly arranged on the cylinder (27).

6. Air spring (2) according to one of the preceding claims, wherein exactly one permanent magnet (24) is fixedly located inside the bellows (21), preferably on the cylinder (27).

7. Air spring (2) according to one of the preceding claims, wherein the sensor (25) is a sensor array (25) which extends along a direction (A) of a relative movement between piston (20) and cover (22) or flange plate (22).

8. Air spring (2) according to claim 7, wherein the sensor array (25) is a Hall effect sensor array (25).

9. Air spring (2) according to one of the preceding claims, wherein the sensor (25), preferably a sensor array (25), is arranged on a printed circuit board, wherein the printed circuit board is connected to the cover (22) or to the crimp plate. (22), preferably with a housing (23), is arranged to move with it.

10. Air spring (2) according to one of the preceding claims, further comprising a control unit (26) configured to operate the sensor (25) based on the detected sensor values, the height of the air spring (2) along a direction (A) of the relative movement between piston (20) 202405748 17 and lid (22) or flange plate (22) to determine and output the determined height.

11. Cargo bike (1) with a chassis (10) with at least two wheels (11) and with a chassis (12) which are resiliently connected to each other by means of at least one air spring (2) according to one of the preceding claims, with an air supply unit (2) which is designed and configured to supply the air spring (2) with compressed air, and with a control unit which is designed to control the air spring (2) to a predetermined height based on its sensor-detected height.

12. Cargo bike (1 ) according to claim 11, wherein the chassis (10) has at least three wheels (11 ) and wherein the chassis (10) and the frame (12) are resiliently connected to each other by at least two air springs (13).

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