Hydraulic braking system for a bicycle

Abstract

The invention relates to a hydraulic brake system of a bicycle, in particular of an electric bicycle, comprising a hydraulic assembly configured for modulating a hydraulic brake pressure, a control unit configured for controlled operation of the hydraulic assembly, a brake caliper, and a first brake line hydraulically connecting the hydraulic assembly and the brake caliper with each other, wherein the hydraulic assembly is configured pumpless, and wherein the brake system is configured for providing a predetermined minimum hydraulic stiffness between the hydraulic assembly and the brake caliper.

Description

Technical Field

[0001] This invention relates to a hydraulic braking system for bicycles, particularly electric bicycles, and an electric bicycle. Background Technology

[0002] Hydraulic braking systems, including anti-lock braking systems (ABS), are known for use in bicycles such as e-bikes. These systems typically include a hydraulic assembly configured to modulate the braking pressure on the brake calipers to provide anti-lock functionality. Especially in bicycles, simple braking systems are often used to keep complexity, weight, and cost low. However, this often results in limitations in performance and user comfort. Summary of the Invention

[0003] The hydraulic braking system according to claim 1 is characterized by providing optimal braking performance and high user comfort while maintaining a particularly simple and inexpensive construction design. This is achieved according to the invention via a hydraulic braking system for a bicycle, preferably an electric bicycle, comprising a hydraulic assembly, a control unit, a brake caliper, and a first brake line. The hydraulic assembly is configured to modulate the hydraulic braking pressure. The control unit is configured to perform controlled operation of the hydraulic assembly, particularly in response to one or more sensor signals, such as at least one wheel speed sensor. The first brake line hydraulically connects the hydraulic assembly and the brake caliper to each other, particularly directly. Here, the hydraulic assembly is pump-free. That is, the hydraulic assembly does not have a pump, which is particularly configured to return hydraulic fluid from the first brake line, for example, in the direction of the brake piston. The braking system is here configured to provide a predetermined minimum hydraulic stiffness between the hydraulic assembly and the brake caliper.

[0004] In particular, the relationship between the expansion of the first braking line and the change in force, especially acting on the hydraulic fluid within the first braking line, is considered the hydraulic stiffness. Preferably, this hydraulic stiffness defines a linear relationship between the expansion and the change in applied force. That is, the hydraulic stiffness is preferably a constant, which is particularly related to the material properties and / or geometric properties of the hydraulic braking system.

[0005] For example, hydraulic stiffness can be considered similar to a spring constant according to Hooke's law.

[0006] In other words, the provided hydraulic braking system has a pump-free hydraulic assembly and a predetermined high hydraulic stiffness between the hydraulic assembly and the brake caliper.

[0007] Hydraulic braking systems offer the following advantages: they enable particularly direct modulation of the hydraulic braking pressure in the performance-related region of the hydraulic braking system, namely the brake caliper, via the hydraulic assembly. Specifically, especially when modulating the hydraulic braking pressure via the hydraulic assembly, the braking pressure on the brake caliper is briefly and periodically reduced to provide anti-lock braking (ABS). Since the hydraulic assembly is pump-less, each time the braking pressure is reduced, a portion of the brake fluid between the hydraulic assembly and the brake caliper is drawn from that region and supplied, for example, to an accumulator. This results in the brake lever continuously moving towards the handlebars during multiple pressure reductions via the hydraulic assembly during braking. The high hydraulic stiffness in the region between the hydraulic assembly and the brake caliper keeps the volume of brake fluid passing through the hydraulic assembly required for a specific pressure reduction particularly small. This allows for particularly direct brake pressure transmission between the hydraulic assembly and the brake caliper. Consequently, for example, the adjustment frequency of the hydraulic assembly for improved ABS can be increased, thereby enabling a faster response to changes in the road surface friction coefficient. In addition, longer adjustment durations can be provided, for example, for longer downhill driving.

[0008] The dependent claims illustrate preferred extensions of the invention.

[0009] Preferably, the minimum hydraulic stiffness is at least 1.0 mm. 3 / bar, especially at least 1.5 mm 3 / bar. This enables the provision of high hydraulic stiffness with exceptional reliability, allowing for optimal, direct, and efficient implementation of pressure modulation via the hydraulic assembly.

[0010] Particularly preferably, the hydraulic braking system further includes a second brake line that hydraulically connects the hydraulic assembly to the brake piston (which is preferably also part of the braking system). The hydraulic braking system is configured to provide a predetermined maximum total hydraulic stiffness. Preferably, the maximum total hydraulic stiffness is a maximum of 5.0 mm. 3 / bar, preferably a maximum of 4.5 mm 3 / bar. This allows for optimal braking deceleration, particularly for bicycles of various common sizes and weights, such as touring or mountain bikes. Preferably, the maximum total hydraulic stiffness is 2.5 mm. 3 / bar. This allows for particularly advantageous and efficient braking performance, for example, for bicycles in higher weight categories, such as freight bicycles. Preferably, in order to provide maximum total hydraulic stiffness while ensuring the high stiffness of the first brake line, a second brake line with lower hydraulic stiffness can be used. This enables optimal brake lever feel when manually operated by the rider, thus also providing high user comfort.

[0011] Preferably, the predetermined minimum hydraulic stiffness is provided by connecting the hydraulic assembly to the brake caliper via a correspondingly short first brake line. In other words, high stiffness is provided, in particular, by providing a first brake line with a shorter hydraulic line length. Since there is less material that can expand when the braking pressure changes with a short brake line, high hydraulic stiffness can be provided in a particularly simple and cost-effective manner.

[0012] Preferably, the length of the first brake line is a maximum of 0.2 m, and particularly preferably a maximum of 0.1 m. This allows for the direct and relatively direct transmission of pressure modulation from the hydraulic assembly to the brake caliper, while using less material and thus having a simpler structure and lower cost.

[0013] More preferably, the predetermined minimum hydraulic stiffness is provided by the high stiffness of the first brake line. That is, a predetermined minimum hydraulic stiffness is achieved between the hydraulic assembly and the brake caliper through appropriate construction and design of the first brake line. In particular, the first brake line here constitutes only a direct hydraulic connection between the hydraulic assembly and the brake caliper. This allows for a direct, hydraulically optimal connection to be achieved in a particularly simple manner.

[0014] Preferably, the high stiffness of the first braking line is provided by a reinforcing braid, which preferably has Kevlar fiber braid and / or steel wire braid. This allows for simple and reliable assurance of minimal expansion of the first braking line and thus ensures its high stiffness while maintaining a light weight and high flexibility.

[0015] Particularly preferably, the hydraulic assembly and control unit are constructed together as a single braking unit, especially an integrated braking unit. That is, the hydraulic assembly and control unit together form a single, operable component. This provides a particularly simple, low-cost, and compact design for the braking system, and also allows for easy assembly. Preferably, the braking unit can be located near the brake caliper, for example, on the bicycle's front fork or rear frame.

[0016] Furthermore, the hydraulic braking system also includes at least one sensor, preferably an inertial sensor. This sensor is specifically configured to determine the wheel speed. Preferably, the braking unit includes at least one sensor. This further simplifies the structural design and installation space of the braking system. Moreover, it enables optimal detection of desired parameters, such as acceleration and / or rotational speed, to provide particularly precise operation of the anti-lock braking system. For example, this allows for particularly efficient and effective dynamic adjustment of anti-lock braking operation.

[0017] More preferably, the hydraulic braking system includes two brake calipers and a separate hydraulic assembly for each caliper. The braking system also includes exactly one common control unit for the two hydraulic assemblies. That is, the common control unit is configured to control the operation of each of the two hydraulic assemblies. Preferably, in this case, the control unit is arranged in a single braking unit along with one of the two hydraulic assemblies. Alternatively, the braking system includes a separate control unit for each hydraulic assembly. Preferably, in this case, each hydraulic assembly is configured as a single braking unit with its corresponding control unit. Such a hydraulic braking system with two separate braking units can also be called a dual-channel system. Preferably, one braking unit may be associated with the front wheel, and the other with the rear wheel. Alternatively, the respective control units of each hydraulic assembly or the common control unit of the two hydraulic assemblies may be configured separately. Such a control unit, independent of one or more hydraulic assemblies, may be installed, for example, in another component of the bicycle, especially an electric bicycle. The control unit may be arranged, for example, in the drive unit or energy storage device of the electric bicycle. The control unit of the hydraulic braking system may also be arranged in the control unit of the bicycle, especially an electric bicycle's drive system. Here, the control device of the drive system can be constructed independently of one of the components of the drive system, wherein the components of the drive system include, in particular, the hydraulic braking system, the drive unit and the energy storage device.

[0018] The hydraulic braking system also includes signal and / or voltage lines that connect the control unit and the hydraulic assembly to each other using signal and / or voltage technology. These signal and / or voltage lines are configured to transmit electrical signals for controlling the hydraulic assembly and / or to provide voltage for supplying power to the hydraulic assembly. In particular, the control unit is here able to communicate with the hydraulic assembly to provide optimal riding operation for the bicycle.

[0019] Preferably, the hydraulic braking system is constructed and arranged such that signal and / or voltage lines and / or braking lines branch off on opposite sides of the hydraulic assembly and / or control unit. That is, the piping arrangement at the hydraulic assembly and / or control unit is such that pipes guiding in opposite directions are arranged on opposite sides of the hydraulic assembly or control unit. This minimizes the piping length and provides a particularly simple, compact, and low-cost structure for the electric bicycle.

[0020] Furthermore, the present invention relates to a drive system for bicycles, particularly electric bicycles, comprising the previously described hydraulic braking system and a drive unit. The drive unit for bicycles, particularly electric bicycles, includes an electric motor for providing motor torque, which is provided as a supplement and / or replacement for the rider's torque. In one embodiment of such a drive system, a control unit is arranged within the drive unit.

[0021] Furthermore, the present invention also relates to a bicycle, particularly an electric bicycle, which includes the described hydraulic braking system or the described drive system. Attached Figure Description

[0022] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings: Figure 1 A simplified schematic diagram of an electric bicycle with a hydraulic braking system according to a first embodiment of the present invention. Figure 2 : Figure 1 A simplified schematic diagram of a hydraulic braking system. Figure 3 A simplified schematic diagram of an electric bicycle with a hydraulic braking system according to a second embodiment of the present invention. Figure 4 A simplified schematic diagram of an electric bicycle with a hydraulic braking system according to a third embodiment of the present invention, and Figure 5 A simplified schematic diagram of an electric bicycle with a hydraulic braking system according to a fourth embodiment of the present invention.

[0023] Preferably, all identical components, elements, and / or units are given the same reference numerals in all figures. Detailed Implementation

[0024] Figure 1 A simplified schematic diagram of an electric bicycle 100 according to a preferred embodiment of the present invention is shown. The electric bicycle 100 includes a drive unit 50 configured to assist the pedaling force of the rider of the electric bicycle 100 by means of motor force.

[0025] The drive unit 50 is powered by the electric energy storage device 109 of the electric bicycle 100.

[0026] The electric bicycle 100 includes a hydraulic braking system 10, by means of which a brake 8 on the front or rear wheel of the electric bicycle 100 can be operated accordingly, the brake 8 being constructed in particular as a brake disc.

[0027] Figure 2 Show Figure 1A simplified schematic diagram of the hydraulic braking system 10.

[0028] The hydraulic braking system 10 includes a brake lever 71, a brake piston 7, a brake caliper 4, a hydraulic assembly 2, a control unit 3, a first brake line 5, and a second brake line 6 for each brake 8.

[0029] The first brake line 5 hydraulically connects the hydraulic assembly 2 and the brake caliper 4 to each other, and the second brake line 6 connects the brake piston 7 and the hydraulic assembly 2 to each other.

[0030] Here, the hydraulic assembly 2 is pumpless and configured to modulate the hydraulic braking pressure during anti-lock braking operation of the hydraulic braking system 10. Therefore, in the event of wheel lock-up (which can preferably be determined by means of sensor 9, which is configured as a wheel speed sensor), the rider can be hydraulically disconnected from the brake caliper 4 via the hydraulic assembly 2. In this state, the hydraulic assembly 2 can reduce the braking pressure on the brake caliper 4, particularly by storing brake fluid located between the hydraulic assembly 2 and the brake 8, i.e., in the first brake line 5 and on the brake caliper 4, in an accumulator of the hydraulic assembly 2. The operation of the hydraulic assembly 2 is controlled by the control unit 3.

[0031] The hydraulic braking system 10 according to the present invention is configured such that a predetermined high hydraulic stiffness exists between the hydraulic assembly 2 and the brake caliper 4. In particular, this hydraulic stiffness is at least 1.5 mm. 3 / bar.

[0032] Hydraulic stiffness plays a decisive role in the rider's brake lever feel and is also related to the optimal execution of anti-lock braking system (ABS).

[0033] The high rigidity between the hydraulic assembly 2 and the brake caliper 4 ensures that during anti-lock braking operation, only a small volume of brake fluid needs to be stored in the accumulator to achieve the reduced braking pressure set on the brake caliper 4. This eliminates the need to replenish the brake fluid volume lost to maintain braking performance from the brake piston 7, which would otherwise cause the brake lever 71 to gradually move closer to the handlebar 72. Besides improving the rider's comfort on the electric bicycle 100, this also provides the advantage of particularly direct and effective brake pressure regulation via the hydraulic assembly 2. Furthermore, it enables anti-lock braking operation for extended periods, thus providing anti-lock braking for prolonged braking maneuvers, such as long downhill rides.

[0034] High stiffness is provided here by having a shorter first brake line 5. That is, the hydraulic assembly 2 is arranged particularly close to the brake caliper 4 by means of a shorter first brake line 5. Alternatively or additionally, the first brake line 5 may have a reinforcing braid, such as Kevlar fiber braid and / or steel wire braid, to provide increased stiffness.

[0035] like Figure 1 As shown, a separate hydraulic assembly 2 is provided for each brake 8. These two hydraulic assemblies 2 are respectively arranged close to their respective brakes 8. Figure 1 In the first embodiment, the hydraulic braking system 10 includes a common control unit 3 for two hydraulic assemblies 2. The common control unit 3 is configured to perform controlled operation on the two hydraulic assemblies 2.

[0036] The common control unit 3 can be located on or near the handlebars 72 of the electric bicycle 100.

[0037] Figure 3 A simplified schematic diagram of an electric bicycle 100 having a hydraulic braking system 10 according to a second embodiment of the present invention is shown. The second embodiment and... Figure 1 and Figure 2 The first embodiment is essentially the same, except that a separate control unit 3 is provided for each hydraulic assembly 2. Each of the two control units 3 is associated with the corresponding hydraulic assembly 2 and is arranged directly adjacent to the hydraulic assembly 2. The hydraulic assembly 2 and the control unit 3 together constitute a braking unit 15, which is specifically constructed as an integral unit.

[0038] This provides a distributed dual-channel braking system 10. Preferably, each braking unit 15 may also additionally include a sensor 9, such as an inertial sensor. Thus, for example, it is possible to detect acceleration and motion particularly directly at the wheels of the electric bicycle 100, in order to provide optimal adjustment for anti-lock braking operation.

[0039] Figure 4 A simplified schematic diagram of an electric bicycle 100 having a hydraulic braking system 10 according to a third embodiment of the present invention is shown. Figure 1 and Figure 2 The first embodiment is basically the same, except that the control unit 3 has an alternative arrangement and an alternative wiring method.

[0040] Specifically, in the third embodiment, the control unit 3 is integrated into the drive unit 50. A signal and / or voltage line 55 is routed from the control unit 3 to each hydraulic assembly 2 to transmit electrical signals for controlling the hydraulic assembly 2 and / or voltages for supplying power to the hydraulic assembly 2.

[0041] Signal and / or voltage lines 55 branch off from opposite sides of the control unit 3. Furthermore, the signal and / or voltage lines 55 and the corresponding first brake lines 5 are connected to opposite sides of each hydraulic assembly 2. This provides a particularly efficient wiring and line guidance method for the hydraulic braking system 10. In particular, it minimizes the length of the conduits, thereby enabling a particularly simple, low-cost, and compact arrangement of the hydraulic braking system 10.

[0042] Figure 5 A simplified schematic diagram of an electric bicycle 100 having a hydraulic braking system 10 according to a fourth embodiment of the present invention is shown. Fourth Embodiment and Figure 4 The third embodiment is basically the same, except for the alternative braking operation method for the rear wheels.

[0043] exist Figure 5 In the fourth embodiment, the hydraulic assembly 2 of the front wheel is connected to the brake caliper 4 of the rear wheel via a first brake line 5. Therefore, the hydraulic assembly 2 on the front wheel is specifically configured to modulate the braking pressure on both wheels of the electric bicycle 100. A modified hydraulic assembly 2' can be provided at the rear wheel, which, for example, can be configured solely for detecting sensor parameters for anti-lock braking operation. The signal and / or voltage lines 55 are arranged in a manner corresponding to... Figure 4 The illustrated implementation of the signal and / or voltage line 55.

Claims

1. A hydraulic braking system for a bicycle (100), particularly an electric bicycle, comprising: - Hydraulic assembly (2), the hydraulic assembly being configured to modulate the hydraulic braking pressure. - Control unit (3), the control unit is configured to perform controlled operation of the hydraulic assembly (2), - Brake calipers (4), and - First brake line (5), which hydraulically connects the hydraulic assembly (2) and the brake caliper (4) to each other. - Wherein, the hydraulic assembly (2) is constructed without a pump, and - Wherein, the braking system (10) is configured to provide a predetermined minimum hydraulic stiffness between the hydraulic assembly (2) and the brake caliper (4).

2. The hydraulic braking system according to claim 1, wherein, The minimum hydraulic stiffness is at least 1.0 mm. 3 / bar, preferably at least 1.5 mm 3 / bar.

3. The hydraulic braking system according to any one of the preceding claims further includes a second brake line (6), the second brake line hydraulically connecting the hydraulic assembly (2) and the brake piston (7) to each other, wherein, The braking system (10) is configured to provide a predetermined maximum total hydraulic stiffness, wherein the maximum total hydraulic stiffness is a maximum of 5.0 mm. 3 / bar, advantageously up to 4.5 mm 3 / bar, preferably a maximum of 2.5 mm 3 / bar.

4. The hydraulic braking system according to any one of the preceding claims, wherein, The predetermined minimum hydraulic stiffness is provided by connecting the hydraulic assembly (2) to the brake caliper (4) via a correspondingly short first brake line (5).

5. The hydraulic braking system according to claim 4, wherein, The length of the first braking line (5) is a maximum of 0.2 m, preferably a maximum of 0.1 m.

6. The hydraulic braking system according to any one of the preceding claims, wherein, The predetermined minimum hydraulic stiffness is provided by the high stiffness of the first brake line (5).

7. The hydraulic braking system according to claim 6, wherein, The high rigidity of the first braking line (5) is provided by reinforced braids, especially Kevlar fiber braids and / or steel wire braids.

8. The hydraulic braking system according to any one of the preceding claims, wherein, The hydraulic assembly (4) and the control unit (5) together constitute a braking unit (15).

9. The hydraulic braking system according to claim 8, wherein, The braking unit (15) also includes at least one sensor (9), particularly an inertial sensor.

10. The hydraulic braking system according to any one of the preceding claims includes two brake calipers (4) and a hydraulic assembly (2) respectively provided for each brake caliper (4), and further includes exactly one common control unit (3) for the two hydraulic assemblies (2).

11. The hydraulic braking system according to any one of claims 1 to 9, comprising two brake calipers (4) and a hydraulic assembly (2) respectively provided for each brake caliper (4), and further comprising a separate control unit (3) respectively provided for each hydraulic assembly (2).

12. The hydraulic braking system according to claim 10 or 11, comprising signal and / or voltage lines (55) connecting the control unit (3) to the hydraulic assembly (2).

13. The hydraulic braking system according to claim 12, wherein, Signal and / or voltage lines (55) and / or brake lines (5, 6) branch off on opposite sides of the hydraulic assembly (2) and / or the control unit (3).

14. A drive system for a bicycle, particularly an electric bicycle, comprising a hydraulic braking system (10) according to any one of the preceding claims and a drive unit (50).

15. The drive system according to claim 14, wherein, The control unit (3) is arranged in the drive unit (50).

16. A bicycle, particularly an electric bicycle, comprising the drive system according to claim 14 or 15.

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