Measuring unit for brake pedal travel, brake system and vehicle

Abstract

The disclosure provides a measuring unit for brake pedal stroke, a brake system and a vehicle. The measuring unit (100) is used for brake pedal stroke, wherein the measuring unit (100) comprises a connector module (1) and a brake pedal module (2), the brake pedal module (2) comprises a connecting piece (21) used for connecting with a brake pedal rod, the connector module (1) comprises a first sensor element (11), a second sensor element (211) is configured on the outer peripheral surface of the connecting piece (21), the first sensor element (11) and the second sensor element (211) constitute a grid displacement sensor, and the first sensor element (11) is used for sensing the displacement of the second sensor element (211). The disclosure senses the brake pedal stroke in a cost-effective, high-resolution and reliable manner.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle braking, and more specifically, to a measuring unit for brake pedal travel, a braking system, and a vehicle. Background Technology

[0002] This section aims to provide background information relevant to understanding the various techniques described herein. As the title of this section implies, this is a discussion of related techniques that should in no way imply that they are necessarily prior art. Therefore, it should be understood that any statement in this section should be read in this context, rather than as an admission of any prior art.

[0003] According to the requirements of GB 12676 and GB / T 13594, vehicle braking systems, such as electronic braking systems (EBS), are widely used in commercial vehicles (CVs). The pedal travel sensor (PTS) is an essential sensor in the brake pedal module of the braking system. The main function of the pedal travel sensor is, for example, to convert pedal displacement into a pulse width modulation (PWM) position signal and send it to the brake control unit (BCU) of the braking system.

[0004] In some technical solutions, the components of the device used for brake pedal travel sensing are relatively complex (involving many moving parts and using various materials), which means that the design, verification, and manufacturing costs of the device are high. Utility Model Content

[0005] Depending on the specifics, the purpose of this disclosure is to sense brake pedal travel in a cost-effective, high-resolution, and reliable manner.

[0006] Furthermore, the purpose of this disclosure is to solve or at least alleviate one or more problems existing in the prior art.

[0007] This disclosure addresses the aforementioned problems by providing a measuring unit for brake pedal travel, a braking system, and a vehicle. Specifically, according to one aspect of this disclosure, the following is provided:

[0008] A measuring unit for brake pedal travel, wherein the measuring unit includes a connector module and a brake pedal module, the brake pedal module includes a connector for connecting to a brake pedal lever, the connector module includes a first sensor element, and a second sensor element is formed on the outer peripheral surface of the connector, the first sensor element and the second sensor element constitute a grid-type displacement sensor, and the first sensor element is used to sense the displacement of the second sensor element.

[0009] Optionally, according to one embodiment of this disclosure, the grid-type displacement sensor is a capacitive grating sensor, wherein the first sensor element is a moving grating and the second sensor element is a fixed grating.

[0010] Optionally, according to one embodiment of this disclosure, the first sensor element and the second sensor element are made of stainless steel, copper or magnetic rubber.

[0011] Optionally, according to one embodiment of the present disclosure, the connector module includes a first housing and a circuit board disposed within the first housing, the first sensor element being disposed on the circuit board, the brake pedal module includes a second housing, and the connector is linearly movably disposed at least partially within the second housing.

[0012] Optionally, according to one embodiment of the present disclosure, the connector module includes a sealing ring, the end face of the first housing is formed with a groove, the sealing ring is disposed in the groove and abuts against the second housing.

[0013] Optionally, according to one embodiment of this disclosure, the circuit board is thermally riveted to the first housing.

[0014] Alternatively, according to one embodiment of this disclosure, the second sensor element is coated, injection molded, or glued to the outer peripheral surface of the connector.

[0015] Optionally, according to one embodiment of the present disclosure, the brake pedal module includes a bracket, the outer peripheral surface of the connector has a recess, the bracket is disposed in the recess, and the outer peripheral surface of the bracket is flush with the outer peripheral surface of the connector, and the second sensor element is constructed on the bracket.

[0016] According to another aspect of this disclosure, a braking system is provided, wherein the braking system includes any of the above-described measuring units and a brake pedal lever, the brake pedal lever being connected to the connector.

[0017] According to another aspect of this disclosure, this disclosure provides a vehicle, wherein the vehicle includes the above-described braking system. Attached Figure Description

[0018] Referring to the accompanying drawings, the above and other features of this disclosure will become apparent, wherein,

[0019] Figure 1 A perspective view of a measuring unit according to the present disclosure is shown;

[0020] Figure 2 A cross-sectional view of a measuring unit according to this disclosure is shown from one angle;

[0021] Figure 3 A cross-sectional view of a measuring unit according to this disclosure is shown from another angle; and

[0022] Figure 4 A plan view of a connector module according to the present disclosure facing the interior of a first housing is shown. Detailed Implementation

[0023] It is readily understood that, based on the technical solutions of this disclosure, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of this disclosure. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solutions of this disclosure and should not be considered as the entirety of this disclosure or as limitations or restrictions on the technical solutions of this disclosure.

[0024] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive. Furthermore, the terms "first," "second," "third," and similar expressions are used for descriptive and distinguishing purposes only and should not be construed as indicating or implying the relative importance of the corresponding components.

[0025] Figure 1 A perspective view of a measuring unit according to the present disclosure is shown; Figure 2 A cross-sectional view of a measuring unit according to this disclosure is shown from one angle; and Figure 3 A cross-sectional view of a measuring unit according to this disclosure is shown from another angle.

[0026] This disclosure relates to a measuring unit 100 for brake pedal travel, wherein the measuring unit 100 includes a connector module 1 and a brake pedal module 2, the brake pedal module 2 includes a connector 21 for connecting to a brake pedal lever, the connector module 1 includes a first sensor element 11, and a second sensor element 211 is formed on the outer peripheral surface of the connector 21 (directly or indirectly), the first sensor element 11 and the second sensor element 211 constitute a grid-type displacement sensor, and the first sensor element 11 is used (directly or indirectly) to sense the displacement of the second sensor element 211.

[0027] It should be noted that brake pedal travel can also be understood as the position of the brake pedal or the travel or position of the brake pedal lever, both of which can be measured using this measuring unit. According to this technical solution, when the driver presses the brake, the pedal drives the brake pedal lever to perform a corresponding braking movement. The pedal lever then directly or indirectly drives the connecting component (also referred to as the valve body) and the second sensor element thereon to perform corresponding movements. For example, from the perspective shown in the figure, this movement is a lifting or vertical movement. This movement is sensed by the first sensor element, which then outputs a response signal. Based on this response signal, those skilled in the art can directly or indirectly obtain the pedal travel.

[0028] This disclosure employs a grid-type displacement sensor to sense the brake pedal travel. It should be understood that the grid-type sensor can accurately capture minute displacements, meeting the measurement requirements for the brake pedal's free travel and effective travel, and avoiding braking lag or false triggering due to measurement errors. The grid-type measurement method ensures consistency across multiple measurements, resulting in high reliability. Furthermore, this sensing method is a non-contact measurement, avoiding the accuracy degradation or wear on related components caused by friction in traditional mechanical sensors. In addition, the sensor offers fast signal processing speed, fast response, low power consumption, and strong environmental adaptability.

[0029] For the specific construction of a grid-type displacement sensor, an exemplary embodiment is a magnetic grating sensor. It should be understood that the magnetic grating sensor includes a magnetic head and a magnetic grating, wherein the magnetic head, as a first sensor element, is a component of the connector module, and the magnetic grating, as a second sensor element. In this regard, the magnetic grating can be composed of alternately magnetized N / S poles, forming a periodic magnetic signal. When the magnetic head and the magnetic grating undergo relative displacement, the magnetic head coil cuts the magnetic lines of force, and according to Faraday's law of electromagnetic induction, an alternating induced electromotive force is generated in the magnetic head. By detecting the phase and frequency changes of the induced signal, the displacement amount and direction can be determined. After processing by electronic circuitry, a high-resolution displacement measurement value can be obtained from the output signal. Therefore, the connector module may include processing circuitry for processing the magnetic head output signal.

[0030] The characteristics of magnetic grating sensors include high precision, no wear, no frictional resistance, strong environmental resistance, large measuring range, low maintenance cost, and fast response.

[0031] In another embodiment, the grid-type displacement sensor is a capacitive grid sensor, wherein the first sensor element 11 is a moving grid and the second sensor element 211 is a fixed grid.

[0032] It should be noted that the naming of the moving grid and the fixed grid is merely illustrative; moving and fixed are relative terms and can be interchanged depending on the reference. In applications involving brake pedal travel sensing, the fixed grid moves up and down with the connector, while the moving grid is fixedly installed within the connector module.

[0033] Those skilled in the art should be familiar with the basic principles of capacitive grating sensors. For example, a capacitive grating sensor is a novel type of digital displacement sensor, a type of capacitive sensor based on the variable area working principle. Its core principle lies in measuring displacement or motion by changing the capacitance value between electrodes. Because its electrodes are arranged like a grid, this type of sensor is called a capacitive grating sensor. Capacitive grating sensors are small in size, low in cost, low in power consumption, and highly adaptable to various environments.

[0034] Structurally, the capacitive grating sensor consists of a moving grating and a fixed grating, with a very small gap between them. The moving grating has multiple transmitting electrodes and a long strip receiving electrode, while the fixed grating has multiple mutually insulated reflecting electrodes and a shielding electrode for grounding. A set of transmitting electrodes has a length of one pitch, and one reflecting electrode corresponds to a set of transmitting electrodes. The reflecting electrode, transmitting electrode, and receiving electrode form a parallel-plate capacitor, respectively. If there are 48 transmitting electrodes, divided into 6 groups, each group has 8 transmitting electrodes. Every 8 electrodes are connected together to form an excitation phase. An excitation signal with the same amplitude, frequency, and phase is applied to the transmitting electrodes of the same number in each group, with a phase difference of 45° (360 / 8°) between excitation signals on adjacent electrodes. If an excitation signal with a phase of 0° is applied to the emitter electrode number 1 in the first group, the phase of the excitation signal on the emitter electrode number 2 will be 45°, and so on. Then the phase of the excitation signal on the emitter electrode number 8 will be 315°. The phase of the excitation signal on the emitter electrode number 9 in the second group is the same as the phase of the emitter electrode number 1 in the first group, which is also 0°, and so on, until the sixth group number 48.

[0035] An electric field exists between the transmitting and reflecting electrodes, and between the reflecting and receiving electrodes. Due to the capacitive coupling and charge transfer of the reflecting electrode, the output signal on the receiving electrode changes with the positions of the transmitting and reflecting electrodes. When one of the moving or fixed gratings moves linearly a certain distance, the relative area between the transmitting and reflecting electrodes changes, the amount of charge on the reflecting electrode changes, and this charge is induced onto the receiving electrode. The charge accumulated on the receiving electrode is proportional to the displacement. If necessary, the moving grating can also be equipped with corresponding processing circuitry to analyze and process the output signal of the moving grating.

[0036] Specifically, as the fixed grating and the moving grating move relative to each other, the amplitude of the induced signal at the receiving electrode does not change significantly, while the phase θ has the following functional relationship with the displacement:

[0037] θ(x)=arctan[(1-2x / w) / (1+√2)]

[0038] Where x represents the displacement and w represents the width of the transmitting electrode. When the displacement changes by a width of w, the receiving electrode experiences a phase difference of 360° / n. The phase is proportional to the displacement. Thus, the capacitive grating sensor can convert mechanical displacement into a phase change in an electrical signal, which is then sent to the measurement circuit for data processing. Therefore, this type of sensor is insensitive to changes in the amplitude of the input signal and has good anti-interference capabilities.

[0039] In terms of materials, the first sensor element 11 and the second sensor element 211 are made of stainless steel, copper, or magnetic rubber. Stainless steel is characterized by its corrosion resistance, high mechanical strength, and stability, while copper is characterized by its good electrical conductivity, thermal stability, ease of processing, and low cost.

[0040] Regarding magnetic rubber materials, the applicant recognizes that in recent years, with the development of materials science, novel materials such as magnetic compound fluid (MCF) rubber have been introduced into sensor design to improve their performance and applicability. In summary, magnetic rubber combines flexibility and magnetism, allowing it to conform to the curved surfaces of connectors and reduce installation stress; it can absorb vibration and shock, preventing sensor failure due to mechanical stress and improving environmental adaptability; its low density reduces sensor weight, and the damping properties of rubber can reduce system noise.

[0041] Specifically, in some embodiments, MCF rubber is a composite material formed by mixing metal particles (such as copper and nickel) with magnetic materials (such as magnetite Fe3O4) within a rubber matrix. Its high sensitivity and good conductivity make it a potential candidate for applications in capacitive grating sensors.

[0042] In addition, metallic materials (such as copper, nickel, nickel-chromium alloys, aluminum alloys, permalloy, and carbon steel), ceramics, or composite materials (such as carbon fiber or glass fiber reinforcement) can also be considered. In practical applications, those skilled in the art can select materials based on specific needs (such as accuracy level, environmental conditions, and cost budget) to achieve the best balance between performance and economy.

[0043] In terms of shape, the second sensor element (e.g., a fixed grid) can be annular (segment), rectangular, or block. Among these, the annular or annular segment structure can better match the shape of the connector (which is usually constructed as a rotating body or cylinder); the straight lines of the rectangular grid are easy to standardize and produce through processes such as photolithography and etching, reducing manufacturing costs; and the block structure has higher strength and stability.

[0044] In some embodiments of this disclosure, the connector module 1 includes a first housing 12 and a circuit board 13 disposed within the first housing 12, the first sensor element 11 being disposed on the circuit board 13, and the brake pedal module 2 includes a second housing 22, the connector 21 being linearly movably disposed at least partially within the second housing 22.

[0045] The first sensor element is arranged on the circuit board, realizing the integration of signal acquisition and processing. The processing circuit for processing the output signal of the first sensor element can also be arranged on the circuit board, thereby outputting a response signal. The first housing provides physical protection for its internal components, such as the circuit board and the first sensor element. At the same time, the housing can serve as a mounting reference, allowing for quick docking with the brake pedal module and improving assembly efficiency. The effect of the second housing can be interpreted similarly.

[0046] This disclosure does not specifically limit the specific structure and connection method between the first and second housings. For example, the end face of the second housing facing the first housing is flat, thereby allowing the first and second housings to be detachably connected via threaded fasteners. Furthermore, an interface 15 is formed on the side of the first housing opposite to the second housing, through which the circuit board, or the entire circuit board assembly, receives power and outputs response signals. The connector module may also include terminals, one end of which is electrically connected to the circuit board, and the connector can mate with the terminals within the first housing to provide power and support signal transmission; that is, the connector powers the circuit board, and the sensing chip on the circuit board can output signals via the connector. The shape, size, and number of the terminals and interfaces can be determined according to the requirements of the connector to be connected. For example, the interface may be constructed in a rounded rectangular shape with a certain accommodating space to facilitate the placement of a portion of the terminal and the connector; moreover, the shapes of the terminals may not necessarily be identical.

[0047] Alternatively, the connector module 1 may include a sealing ring 14, and the end face of the first housing 12 may have a groove 121, with the sealing ring 14 disposed in the groove 121 and abutting against the second housing 22.

[0048] It should be understood that sealing rings are used to prevent leakage of air, water, dust, etc., to achieve a seal. Specifically, the sealing ring is positioned between the first and second housings to achieve a seal at their connection point. The specific placement of the sealing ring can be determined based on the assembly relationship and shape of the two housings. In this example, the second housing is generally a hollow cylinder, but it has a flat flange surface facing the first housing. Therefore, the first housing has a corresponding abutment surface facing the second housing, and the sealing ring is further installed in a groove so that it can abut against the circumference of the second housing, or even against both housings simultaneously, to complete the seal. Furthermore, the ring shape, or closed structure, ensures a complete seal. It is also known that, in addition to sealing rings, sealing can also be achieved through methods such as ring welding.

[0049] Figure 4 A plan view of a connector module according to the present disclosure facing the interior of a first housing is shown.

[0050] The circuit board 13 is thermally riveted to the first housing 12. For this purpose, the bottom surface of the first housing can be provided with a protrusion 122, and the circuit board has corresponding through holes for the protrusion to pass through. The advantages of thermal riveting include high efficiency, enhanced connection strength, wide material applicability, and advantages in the processing (no vibration, no noise). Therefore, the first housing can be made of plastic to well support the thermal riveting process. It is also understood that other connection methods between the circuit board and the first housing, such as mounting, threaded connection, snap-fit, welding, adhesive bonding, and locking, are also applicable.

[0051] In addition, to improve installation convenience and pre-positioning, the bottom surface of the first housing can also be equipped with a positioning pin 123 and an assembly pin 124. During assembly, the circuit board and the assembly pin first form a snap-fit ​​engagement to complete the initial positioning. Then, the circuit board engages with the positioning pin and finally achieves thermal riveting with the protrusion to complete the fixation. Subsequently, the assembly formed by the first housing and the circuit board assembly is then assembled with the sealing ring to form a connector module.

[0052] In terms of manufacturing process, the second sensor element 211 is coated, injection molded, or glued to the outer peripheral surface of the connector 21. Coating reduces the impact of ambient humidity on capacitive coupling, prevents signal drift, improves measurement accuracy, and has a lower implementation cost. Injection molding integrates the second sensor element with the outer peripheral surface of the connector, eliminating assembly gaps, improving impact resistance, and offering good dimensional accuracy and a short manufacturing cycle. Glue bonding is highly adaptable, requires no complex or precision equipment, has low energy consumption, and high material utilization. Those skilled in the art can also choose other process methods based on cost and performance requirements, such as vapor deposition, photolithography, electroplating, laser melting, and photopolymerization.

[0053] Combination Figure 3 It is also evident that the brake pedal module 2 includes a bracket 23, the outer peripheral surface of the connector 21 has a recess 212, the bracket 23 is disposed in the recess 212, and the outer peripheral surface of the bracket 23 is flush with the outer peripheral surface of the connector 21, and the second sensor element 211 is constructed on the bracket 23.

[0054] This technical solution reveals that the bracket, through its recessed embedded design, reduces the radial dimension of the brake pedal module, adapting to compact installation spaces. The recess also provides a precise mounting reference for the bracket, reducing assembly and adjustment time. The flush outer surface design optimizes NVH (noise, vibration, and harshness) performance. Thus, the bracket can be designed as a universal component, or it can pre-integrate the second sensor element, assembling it as an independent sub-module, simplifying the overall assembly process. It can also be well-applied to different types or specifications of connectors, improving assembly efficiency. Furthermore, in the event of a second sensor element failure, only the bracket module needs to be replaced, reducing repair costs and improving maintenance efficiency.

[0055] This disclosure also relates to a braking system, wherein the braking system includes any of the above-described measuring units 100 and a brake pedal lever, the brake pedal lever being connected to the connector 21; and a vehicle, wherein the vehicle includes the above-described braking system.

[0056] Therefore, the braking system and vehicle disclosed herein inherit various implementation methods and technical effects of the measuring unit, which will not be described in detail here.

[0057] It should be understood that all the above preferred embodiments are exemplary and not restrictive, and various modifications or variations made by those skilled in the art to the specific embodiments described above under the concept of this disclosure should be within the legal protection scope of this disclosure.

Claims

1. A measuring unit (100) for brake pedal travel, characterized in that, The measuring unit (100) includes a connector module (1) and a brake pedal module (2). The brake pedal module (2) includes a connector (21) for connecting to the brake pedal lever. The connector module (1) includes a first sensor element (11). A second sensor element (211) is constructed on the outer peripheral surface of the connector (21). The first sensor element (11) and the second sensor element (211) constitute a grid-type displacement sensor. The first sensor element (11) is used to sense the displacement of the second sensor element (211).

2. The measuring unit (100) according to claim 1, characterized in that, The grid-type displacement sensor is a capacitive grid sensor, wherein the first sensor element (11) is a moving grid and the second sensor element (211) is a fixed grid.

3. The measuring unit (100) according to claim 2, characterized in that, The first sensor element (11) and the second sensor element (211) are made of stainless steel, copper or magnetic rubber.

4. The measuring unit (100) according to claim 1, characterized in that, The connector module (1) includes a first housing (12) and a circuit board (13) disposed within the first housing (12), the first sensor element (11) being disposed on the circuit board (13), the brake pedal module (2) includes a second housing (22), and the connector (21) is linearly movable and at least partially disposed within the second housing (22).

5. The measuring unit (100) according to claim 4, characterized in that, The connector module (1) includes a sealing ring (14), and the end face of the first housing (12) is provided with a groove (121). The sealing ring (14) is disposed in the groove (121) and abuts against the second housing (22).

6. The measuring unit (100) according to claim 4, characterized in that, The circuit board (13) is thermally riveted to the first housing (12).

7. The measuring unit (100) according to claim 1, characterized in that, The second sensor element (211) is coated, injection molded or glued to the outer peripheral surface of the connector (21).

8. The measuring unit (100) according to claim 1, characterized in that, The brake pedal module (2) includes a bracket (23), the outer peripheral surface of the connector (21) has a recess (212), the bracket (23) is disposed in the recess (212), and the outer peripheral surface of the bracket (23) is flush with the outer peripheral surface of the connector (21), and the second sensor element (211) is constructed on the bracket (23).

9. A braking system, characterized in that, The braking system includes a measuring unit (100) according to any one of claims 1 to 8 and a brake pedal lever, the brake pedal lever being connected to the connector (21).

10. A vehicle, characterized in that, The vehicle includes the braking system according to claim 9.

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