A high precision torque sensor for a steering system

Abstract

The utility model discloses a high accuracy torque sensor for steering system, including stator casing, the inside integrated fixed mounting of stator casing has the circuit board, the wire harness assembly is commonly installed between the circuit board and stator casing, the inside of stator casing is filled with epoxy resin, and the epoxy resin is located the top of circuit board. In the utility model, through adopting the unique C type semicircle structure stator casing design, first, the installation convenience of client and process degree of freedom have been greatly promoted, and the sensor need no longer from the shaft end and install, can assemble from the lateral at any time, second, this structure effectively reduces the overall size of casing and internal circuit board, makes the sensor structure more compact, improves the detachability and maintainability of product significantly, can change fast when damage occurs, thereby greatly reduces the detection and maintenance cost of later period.

Description

Technical Field

[0001] This utility model relates to the field of torque sensor technology, and in particular to a high-precision torque sensor for steering systems. Background Technology

[0002] Current mainstream steering system sensors are all integrated TAS, which are used to simultaneously measure the torque and steering angle of the steering wheel, providing key input signals for electric power steering (EPS), electronic stability program (ESP) and advanced driver assistance systems (ADAS).

[0003] Disadvantages / deficiencies of existing technology:

[0004] 1. The TAS structure is complex. Currently, all TAS on the market are circular designs, which require through-shaft installation and then welding to fix them. If the sensor is damaged, the entire system must be replaced because the welding process at the back end is not removable, resulting in high after-sales maintenance costs.

[0005] 2. Integrated sensor TAS has a complex design, resulting in high development and BOM costs;

[0006] To address this, we propose a high-precision torque sensor for steering systems. Utility Model Content

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-precision torque sensor for steering systems.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a high-precision torque sensor for a steering system, comprising a stator housing, wherein a circuit board is integrated and fixedly installed inside the stator housing, and a wiring harness assembly is installed between the circuit board and the stator housing;

[0009] The stator housing is filled with epoxy resin, and the epoxy resin is located above the circuit board.

[0010] Target wheel blade A and target wheel blade B are respectively disposed above and below the stator housing;

[0011] The stator housing adopts a C-shaped semi-circular structure design.

[0012] Furthermore, the circuit board is fixed to the stator housing by four-point hot riveting, and the surface of the circuit board is covered with eddy current coils and processing chips. This fixing method is firm and reliable, and can effectively resist vibration and impact during vehicle operation.

[0013] Furthermore, the top of the stator housing is provided with an assembly slot for mounting the wire harness assembly. The assembly slot structure provides the wire harness with a dedicated and reliable mounting path and positioning reference.

[0014] Furthermore, the wire harness assembly includes a wire harness bracket, which is fitted into the assembly slot with an interference fit. The inner side of the wire harness bracket is fixedly connected to the wire harness body, and one end of the wire harness body is fixedly connected to the circuit board. The interference fit ensures that the wire harness bracket does not loosen in the assembly slot.

[0015] Furthermore, the stator housing is made by plastic injection molding. The plastic injection molding process can achieve one-time molding of complex shapes, which greatly reduces manufacturing costs.

[0016] Furthermore, both the target wheel blade A and the target wheel blade B are manufactured by stamping. The stamping process is efficient and low-cost, and can mass-produce toothed blades with consistent shape and high precision.

[0017] Furthermore, the stator housing, target wheel blade A, and target wheel blade B are aligned, and their axes are strictly aligned to ensure the uniformity and symmetry of the air gap between the target wheel blade and the coil inside the stator housing.

[0018] The beneficial effects of this utility model are:

[0019] In use, this utility model, through its unique C-shaped semi-circular stator housing design, firstly greatly improves the ease of installation and process flexibility for the client, eliminating the need for the sensor to be fitted from the shaft end and allowing for assembly from the side at any time; secondly, this structure effectively reduces the overall size of the housing and internal circuit board, making the sensor structure more compact, while significantly improving the product's disassembly and maintainability, enabling rapid replacement in case of damage, thereby greatly reducing subsequent testing and maintenance costs. Attached Figure Description

[0020] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the exploded structure of this utility model;

[0022] Figure 2 This is a three-dimensional structural diagram of the present invention.

[0023] The attached figures are labeled as follows:

[0024] 1. Target wheel blade B; 2. Stator housing; 3. Circuit board; 4. Wire harness bracket; 5. Wire harness body; 6. Epoxy resin; 7. Target wheel blade A. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0026] like Figures 1-2 As shown, a high-precision torque sensor for a steering system is disclosed, including a stator housing 2, which is made of plastic injection molding. The stator housing 2 adopts a C-shaped semi-circular structure design. This design not only significantly reduces the overall weight and manufacturing cost of the sensor, but its C-shaped opening also eliminates the need for the sensor to be inserted from the shaft end, greatly improving the ease of installation in the confined engine compartment and the removability during maintenance.

[0027] The stator housing 2 has a circuit board 3 integrated and fixedly installed inside. The circuit board 3 is fixed to the stator housing 2 by four-point hot riveting. The surface of the circuit board 3 is covered with eddy current coils and processing chips. The four-point hot riveting provides uniform and firm mechanical fixation, which can effectively resist strong vibrations during vehicle operation.

[0028] A wire harness assembly is installed between the circuit board 3 and the stator housing 2. The top of the stator housing 2 has an assembly slot for installing the wire harness assembly. The wire harness assembly includes a wire harness bracket 4, which is fitted into the assembly slot with an interference fit. The inner side of the wire harness bracket 4 is fixedly connected to the wire harness body 5, and one end of the wire harness body 5 is fixedly connected to the circuit board 3. The modular design of the wire harness assembly simplifies the assembly process, improves production efficiency, and facilitates subsequent maintenance and replacement.

[0029] The stator housing 2 is filled with epoxy resin 6, and the epoxy resin 6 is located above the circuit board 3. After the epoxy resin 6 is cured, it forms a solid protective layer that can effectively prevent moisture, dust and corrosion, and greatly improve the weather resistance and long service life of the sensor in harsh automotive environments.

[0030] The stator housing 2 is provided with target wheel blade A7 and target wheel blade B1 at the top and bottom respectively. Target wheel blade A7 and target wheel blade B1 are both made by stamping. The stator housing 2, target wheel blade A7 and target wheel blade B1 are aligned.

[0031] Working principle: The stator housing 2 is a stationary component and is fixedly installed. The target wheel blade A7 and the target wheel blade B1 are fixedly installed at both ends of the torsion bar of the steering system by interference fit, and their axes are aligned with the axis of the stator housing 2.

[0032] When the sensor is powered on, the transmitting coil on the circuit board 3 generates a high-frequency alternating magnetic field. Due to the unique C-shaped opening design of the stator housing 2, this magnetic field is effectively radiated outward and acts on the target wheel blades A7 and B1 located within its opening area.

[0033] Target blades A7 and B1 act as eddy current inductors. Under the influence of an alternating magnetic field, vortex-shaped closed currents, or "eddy currents," are induced on their surfaces. According to Lenz's law, these eddy currents generate a secondary magnetic field that is opposite in direction to the original transmitting magnetic field, thereby weakening the original magnetic field.

[0034] The special tooth profile design of target wheel blades A7 and B1 causes the relative coverage area between them and the stator housing 2 to change regularly with the rotation of the steering shaft and torsion bar. As the blades rotate, their tooth tips and grooves alternately align with the sensor's sensing area, causing periodic changes in the intensity of the eddy currents, thus altering the degree of weakening of the transmitted magnetic field. This changing magnetic field is captured by the sine and cosine receiving coils arranged on the circuit board 3.

[0035] The receiving coil converts the induced magnetic field strength changes into corresponding electrical signals with sine and cosine characteristics. These weak analog signals are transmitted to the processing chip for amplification, conditioning, and calculation, and are finally converted into a set of voltage signals that can accurately reflect the absolute angular position of the target wheel blades, and are output in real time through the wiring harness body 5.

[0036] Since target wheel blades A7 and B1 are fixed at both ends of the torsion bar, when the driver applies torque by turning the steering wheel, the torsion bar undergoes a slight elastic twist. At this time, a small relative angular displacement occurs between the two target wheel blades. The electronic control unit (ECU) receives two angular signals from the sensors and calculates the phase difference or angle difference between these two signals, thus accurately calculating the real-time torque value based on the torsion bar's stiffness coefficient. This torque value is the core input parameter for realizing the electric power steering (EPS) function.

[0037] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A high-precision torque sensor for a steering system, characterized in that: Includes a stator housing (2), inside which a circuit board (3) is integrated and fixedly installed, and a wire harness assembly is installed between the circuit board (3) and the stator housing (2); The interior of the stator housing (2) is filled with epoxy resin (6), and the epoxy resin (6) is located above the circuit board (3); The target wheel blade A (7) and the target wheel blade B (1) are respectively provided above and below the stator housing (2); The stator housing (2) adopts a C-shaped semi-circular structure design.

2. A high-precision torque sensor for a steering system according to claim 1, characterized in that: The circuit board (3) is fixed to the stator housing (2) by four-point hot riveting, and the surface of the circuit board (3) is covered with an eddy current coil and a processing chip.

3. A high-precision torque sensor for a steering system according to claim 1, characterized in that: The top of the stator housing (2) is provided with an assembly slot for installing wire harness assemblies.

4. A high-precision torque sensor for a steering system according to claim 3, characterized in that: The wire harness assembly includes a wire harness bracket (4), which is fitted into the assembly slot with an interference fit. The inner side of the wire harness bracket (4) is fixedly connected to the wire harness body (5), and one end of the wire harness body (5) is fixedly connected to the circuit board (3).

5. A high-precision torque sensor for a steering system according to claim 1, characterized in that: The stator housing (2) is made by plastic injection molding.

6. A high-precision torque sensor for a steering system according to claim 1, characterized in that: Both the target wheel blade A (7) and the target wheel blade B (1) are manufactured by stamping.

7. A high-precision torque sensor for a steering system according to claim 1, characterized in that: The stator housing (2), target wheel blade A (7) and target wheel blade B (1) are aligned.

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