Device and method for testing hydraulic rigidity of brake caliper

Abstract

The invention belongs to the field of automobile brake testing, and relates to a brake caliper hydraulic rigidity testing device and method. And two aligning structures and a clamping structure. The two alignment structures have the function of enabling the to-be-tested position of the caliper to be in a vertical central plane, so that the plurality of displacement detection structures slide along the Y direction, and the side surfaces are locked after alignment for detecting the displacement of the to-be-tested position; the clamping structure has an X-direction adjusting function and a Y-direction adjusting function and can be adjusted in the X direction through an adjustable cushion block; a bolt hole in the adjustable clamp is matched with a test piece mounting hole in a sliding mode in the Y direction; the simulation disc adapts to test pieces with different disc diameters and disc thicknesses, and the X direction is perpendicular to the Y direction. The system is pressurized, and the displacement sensor transmits data to the test analyzer through multiple channels. Establishing a relational graph between the caliper displacement and the fluid pressure; the invention relates to a relational graph between brake pad back plate deformation and fluid pressure. Through the hydraulic rigidity testing device, the testing precision can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of automotive brake testing, and relates to a hydraulic stiffness testing device and method for a brake caliper. Background Art

[0002] Stiffness and deformation, hydraulic stiffness, literally refers to the ability to resist deformation under the action of pressure in a hydraulic (brake) system, which is manifested as the relationship between pressure change and displacement change (volume change). Hydraulic stiffness not only has a direct impact on traditional braking performances and safety such as braking response speed, pedal feel and override (required liquid volume change), and heat fade resistance ability, but also, with the continuous increase in users' demands for subjective experiences such as comfort and psychological pleasure cues, it poses challenges to non-traditional braking safety performances. For example, the extreme evaluation and pursuit of jitter, tremor, low-frequency noise, etc. are becoming stronger and stronger. And recent new research shows that hydraulic stiffness has an increasingly intuitive and positive impact on analyzing jitter and low-frequency noise. For example, poor rigidity induces noises such as jitter, tremor, low-frequency moan, groan, etc. Moreover, most traditional rigidity tests focus on the rigidity of the caliper body itself, and the new fault mode of jitter and low-frequency noise is more directly related to the deformation and stability of the brake pads. However, traditional deformation tests do not test the deformation rigidity of the brake pads and cannot accurately analyze this non-traditional braking problem in a targeted manner. Therefore, it is very important and targeted to establish a hydraulic stiffness test system, increase the accurate test of the deformation of the brake pads, and establish a corresponding stiffness evaluation system.

[0003] Currently, the common technical solutions for testing the stiffness of brake calipers in the industry mostly only use the general technical solution of single-point axis deformation at both ends of the caliper, lacking the lattice test of the central plane of the caliper and being unable to test the deformation of the brake pads itself. The specific technical limitations are as follows:

[0004] (1) Single hydraulic stiffness test method: Currently, the test is limited to single-point tests along the axis of the cylinder head and claw part of the caliper body. The influence caused by the special shape of the caliper body and the non-smooth surface of the casting is not eliminated, and the deformation of the brake pads is not measured, which cannot meet the high-precision calibration requirements and accurately analyze the braking performances such as jitter in a targeted manner.

[0005] (2) Evaluation error caused by incomplete evaluation: Traditional test evaluations use simulated single-point axis deformation, resulting in large test result errors and serious distortion of prediction results.

[0006] (3) Insufficient clamping adaptability: Due to the model adaptation requirements of the brake caliper, there are various specifications for the mounting hole pitch, such as 140mm, 160mm, 170mm, etc. Existing fixtures mostly have a fixed hole pitch structure. When testing calipers of different models, the fixtures need to be frequently replaced, and it is difficult to ensure the clamping coaxiality (when the deviation > 0.5mm, the risk of axis deviation increases by 40%), which greatly affects the test efficiency and data reliability.

[0007] The above technical defects lead to the R & D verification of the brake caliper relying heavily on later bench tests and on-road vehicle tests, and the problems are as follows:

[0008] The design iteration cycle is extended: due to the deviation between the laboratory test data and the actual vehicle conditions, the designers need to repeatedly adjust the parameters of the caliper bridge, conduct topology optimization, and mold multiple samples. The design optimization cycle is as long as 3 - 4 months; multiple moldings lead to a sharp increase in costs;

[0009] The quality control cost climbs: the production end cannot quickly detect and screen out products with deformation exceeding the tolerance, the probability of after-sales jitter faults increases by about 20%, and the annual recall cost of vehicle enterprises exceeds tens of millions of yuan;

[0010] The user experience is damaged: the continuous increase in users' demands for subjective experiences such as comfort and psychological pleasure hints challenges the non-traditional safety performance of braking. For example, the extreme evaluation and pursuit of jitter, tremor, low-frequency noise, etc. are becoming stronger and stronger, and the user complaint rate increases by 15% - 25%.

[0011] Therefore, developing a "hydraulic stiffness" performance test device dedicated to the brake caliper assembly to achieve high-precision, multi-condition, and fully adaptable standardized testing has become an urgent need to break through the industry's technical bottlenecks and improve the reliability and comfort of the braking system. Summary of the Invention

[0012] In view of this, the purpose of the present invention is to provide a brake caliper hydraulic stiffness test device and method to test the hydraulic stiffness of the brake caliper, which is of great significance for improving performance such as reducing drag, matching the required liquid volume, analyzing brake jitter, and analyzing low-frequency noise, and for topology optimization and lightweight design of the structure.

[0013] To achieve the above purpose, the present invention provides the following technical solution: a brake caliper hydraulic stiffness test device, including an installation platform, adjustable alignment structures symmetrically arranged at both ends of the installation platform, and a clamping system and a simulation disk located between the two alignment structures;

[0014] The two alignment structures are arranged at both ends of the installation platform in an adjustable manner along the X direction through connecting bolts. Each alignment structure is provided with a sensor positioning hole and a displacement detection positioning rod that can slide along the Y direction, and the displacement detection positioning rod is fixed by a side fastening bolt;

[0015] The clamping structure includes an adjustable cushion block and an adjustable fixture. The adjustable cushion block adjusts the distance between the test piece installation surface and the braking surface along the X direction through a mother-daughter cushion block structure; the adjustable fixture is provided with bolt holes that can slide along the Y direction to adapt to test pieces with different mounting hole distances;

[0016] Among them, the sensor positioning hole of the alignment structure is centered with the center of the clamping structure to form a vertical central plane, and the X direction is orthogonal to the Y direction.

[0017] Optionally, the simulation disc is installed on the installation platform by a quick-change method to adapt to test pieces with different disc diameters and disc thicknesses.

[0018] Optionally, the test device further includes a pressure regulation system and a multi-channel data transmission and analysis system for displacement sensors; the pressure regulation system includes a liquid storage tank, a pressure regulation gauge, and a flowmeter, and is connected to the test piece through a hydraulic pipeline; the multi-channel data acquisition and analysis system includes displacement sensors, a multi-channel data acquisition and analyzer, and a computer.

[0019] Optionally, the displacement sensors are installed on displacement detection and positioning rods; the multi-channel data acquisition and analyzer is connected to all displacement sensors through signal lines; the computer communicates with the multi-channel data acquisition and analyzer to process data.

[0020] Optionally, after the displacement detection and positioning rod of the alignment structure is locked by a fastening bolt, the displacement sensors connected to its end are arranged at the following test points: the outer circumference A of the outer caliper of the caliper cylinder head, the outer circumference B of the outer back plate, the outer circumference D of the inner caliper, the outer circumference C of the inner back plate; the inner circumference E of the outer caliper of the caliper claw part, the inner circumference F of the outer back plate, the inner circumference G of the inner back plate, and the inner circumference H of the inner caliper.

[0021] Optionally, the Y-direction adjustment range of the adjustable fixture includes 140mm, 160mm, and 170mm, and is locked after being aligned with the test piece mounting hole through the sliding bolt hole.

[0022] A method for testing the hydraulic stiffness of a brake caliper, which applies a brake caliper hydraulic stiffness test device as described above, and the test piece to be tested is a brake caliper, and includes the following steps:

[0023] S1, clamping and adjusting step: Adjust the Y-direction mounting hole distance of the test piece through the adjustable fixture, adjust the distance between the X-direction mounting surface of the test piece and the brake disc through the adjustable spacer, adapt to different disc diameters and disc thicknesses through the simulation disc, and clamp the test piece;

[0024] S2, sensor positioning step: Adjust the position of the displacement sensor through the displacement sensor positioning hole on the alignment structure; and adjust the X-direction position of the displacement sensor connecting rod to make the test position in the vertical center plane;

[0025] S3, pressurization and testing step: Apply fluid pressures of 0.5MPa and 1 - 12MPa respectively at each test point from A to H of the test piece, and collect the displacement data of each test point in real time through the multi-channel data acquisition and analyzer;

[0026] S4, data processing step: Establish a relationship diagram between the caliper displacement and the fluid pressure and a relationship diagram between the deformation of the brake pad back plate and the fluid pressure according to the deformation corresponding to each pressure.

[0027] Optionally, a test evaluation system is formed: comprehensive evaluation is performed by using single-point hydraulic pressure & deformation, vertical plane deformation at the center of the clamp body, and vertical deformation at the center of the inner and outer brake backplates to form a hydraulic pressure & deformation curve.

[0028] Optionally, in the said evaluation system, single-point hydraulic pressure & deformation evaluation is first adopted to form a hydraulic pressure & deformation curve for each point of A, B, C, D﹍﹍H respectively; the vertical plane deformation at the center of the clamp body is comprehensively evaluated, and the deformation of the clamp body = (|displacement E - displacement H|) - (|displacement A - displacement D|); and the vertical plane deformation at the center of the brake backplate is evaluated, and the deformation of the inner and outer backplates = (|displacement F - displacement G|) - (|displacement B - displacement C|).

[0029] The beneficial effects of the present invention are as follows:

[0030] 1) The present invention relates to a brake caliper hydraulic stiffness test device and method, which realizes accurate and real tests of hydraulic stiffness. Through this innovative test method, we can deeply analyze and evaluate the design rationality of key performance parameters such as drag torque and liquid demand. This not only helps to optimize the overall design of the brake caliper and improve its performance under different working conditions, but also provides a strong analysis basis and solution for possible failure modes and problems such as jitter and low-frequency noise during the use of the end product. Thereby further enhancing the safety and driving experience of users.

[0031] 2) The present invention relates to a brake caliper hydraulic stiffness test device and method, which elaborates in detail the test principle, the constituent units of the test device, and the test guarantee conditions. The test device consists of multiple modules such as a pressure regulation system, a clamping and alignment unit, and a test data analysis system. Each module is carefully designed to ensure the accuracy and reliability of the test process. By clarifying the test principle and the functions and cooperation methods of each constituent unit, the present invention provides a strong guarantee for the complete and accurate implementation of the test method. At the same time, the use of the test device also helps to improve the first-pass rate of the research and development of the brake caliper assembly, greatly shortening the research and development cycle and reducing the development time and cost of the test bench and road test. In addition, due to the simple structure, convenient operation, and high degree of automation of the test device, it is easy to be popularized and applied in the industry, contributing new strength to the development of automotive braking test technology.

[0032] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be learned from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. Description of the Drawings

[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail and preferably below in conjunction with the accompanying drawings, where:

[0034] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0035] Figure 2 is a test flow chart of the present invention;

[0036] Figure 3 is a dot matrix schematic diagram of the caliper test part of the present invention;

[0037] Figure 4 is a schematic diagram of the multi-hole pitch adjustable structure of the present invention;

[0038] Figure 5 is a schematic diagram of the curve of the test structure data processing result of the present invention.

[0039] Reference numerals: mounting platform 1, simulation disc 2, adjustable cushion block 3, adjustable fixture 4, alignment structure 5, alignment structure 6, brake backplate extension support 7, 8, test piece to be tested 9, fastening bolt 10, connecting bolt 11, adjusting bolt 12, displacement detection positioning rod 13, displacement sensor 14. Specific embodiments

[0040] The following illustrates the implementation manners of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the drawings provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0041] Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to the present invention; for better illustrating the embodiments of the present invention, some components in the drawings will be omitted, enlarged or reduced, which does not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0042] In the drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and should not be construed as a limitation of the present invention. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0043] Please refer to Figures 1 to 5 , which is a hydraulic stiffness test device for a brake caliper, including an installation platform 1, adjustable alignment structures 5 and alignment structures 6 symmetrically arranged at both ends of the installation platform 1, and a clamping system and a simulation disc 2 located between the two alignment structures; the two alignment structures are arranged at both ends of the installation platform in an adjustable manner along the X direction through connecting bolts 11. Each alignment structure is provided with a sensor positioning hole and a displacement detection positioning rod 13 that can slide along the Y direction. The displacement detection positioning rod 13 is fixed by a side fastening bolt 10; the clamping system includes an adjustable spacer 3 and an adjustable fixture 4. The adjustable spacer 3 adjusts the distance between the test piece installation surface and the brake surface along the X direction through a mother-daughter spacer structure; the adjustable fixture 4 is provided with a bolt hole that can slide along the Y direction and is used to adapt to test pieces with different installation hole distances through an adjustment bolt 12; wherein, the sensor positioning hole of the alignment structure is centered with the center of the clamping system to form a vertical central plane, and the X direction and the Y direction are orthogonal.

[0044] The simulation disc 2 is installed on the installation platform in a quick-change manner to adapt to test pieces with different disc diameters and disc thicknesses. The test device also includes a pressure regulation system and a displacement sensor multi-channel data transmission and analysis system; the pressure regulation system includes a liquid storage tank, a pressure regulation gauge and a flow meter, and is connected to the test piece through a hydraulic pipeline; the multi-channel data acquisition and analysis system includes a displacement sensor 14, a multi-channel data acquisition analyzer and a computer. The displacement sensor is installed on the displacement detection positioning rod 13; the multi-channel data acquisition analyzer is connected to all displacement sensors through signal lines; the computer communicates with the multi-channel data acquisition analyzer to process data.

[0045] After the displacement detection positioning rod 13 of the alignment structure of the present invention is locked by the fastening bolt 10, the displacement sensor 14 connected to its end is arranged at the following test points: the outer circumference A of the outer caliper of the caliper cylinder head, the outer circumference B of the outer back plate, the outer circumference D of the inner caliper, the outer circumference C of the inner back plate; the inner circumference E of the outer caliper of the caliper claw part, the inner circumference F of the outer back plate, the inner circumference G of the inner back plate, the inner circumference H of the inner caliper.

[0046] The Y-direction adjustment range of the adjustable fixture 4 of the present invention includes 140 mm, 160 mm, and 170 mm, and is locked after aligning the sliding bolt holes with the test piece mounting holes.

[0047] A method for testing the hydraulic stiffness of a brake caliper, which applies a brake caliper hydraulic stiffness testing device as described above, and the test piece 9 to be tested is a brake caliper, including the following steps:

[0048] S1, clamping and adjusting step: Adjust the distance between the Y-direction mounting holes of the test piece through the adjustable fixture 4, adjust the distance between the X-direction mounting surface of the test piece and the brake disc through the adjustable spacer 3, adapt to different disc diameters and disc thicknesses through the simulation disc 2, and clamp the test piece;

[0049] S2, sensor positioning step: Locate the displacement sensor through the positioning holes on the alignment structure to adjust the position of the displacement sensor 14; and adjust the position of the displacement detection and positioning rod 13 in the X direction to make the test position in the vertical central plane;

[0050] S3, pressurization and testing step: Apply fluid pressures of 0.5 MPa and 1 - 12 MPa respectively at each test point from A to H of the test piece, and collect the displacement data of each test point in real time through a multi-channel data acquisition and analyzer;

[0051] S4, data processing step: According to the deformation corresponding to each pressure, establish a relationship diagram between the caliper displacement and the fluid pressure and a relationship diagram between the deformation of the brake pad back plate and the fluid pressure.

[0052] Among them, the test and evaluation form a system: Adopt single-point hydraulic & deformation, deformation of the vertical central plane of the caliper body, and deformation of the vertical center of the inner and outer brake back plates to form a comprehensive evaluation and form a hydraulic & deformation curve.

[0053] Among them, the evaluation system first uses single-point hydraulic & deformation evaluation to form hydraulic & deformation curves for each point from A, B, C, D... H respectively; comprehensively evaluate the deformation of the vertical central plane of the caliper body, and the caliper body deformation amount = (|displacement E - displacement H|) - (|displacement A - displacement D|); and the deformation of the vertical central plane of the brake back plate, and the deformation amount of the inner and outer back plates = (|displacement F - displacement G|) - (|displacement B - displacement C|).

[0054] Specific embodiment 1,

[0055] Test the brake caliper assembly with a test mounting hole distance of 140, a distance from the mounting surface to the center of the brake surface of 30, a disc diameter of 350, and a disc thickness of 32:

[0056] 1. Clamp and automatically align: According to the test part mounting hole distance, use the adjustable fixture 4 to adjust the butt joint mounting hole distance to 140;

[0057] 2. According to the distance of 30 from the caliper mounting surface to the brake surface, use the adjustable spacer 3 to adjust the distance to 30 to adapt to the center distance;

[0058] 3. According to the different large arcs of the caliper body and the opening of the claw part, adapt the simulated brake disc 2 of 350×32, and complete the installation of the brake caliper assembly;

[0059] 4. Adjust the pressurizing system: The pressurizing system applies a pre-pressure of 7 MPa for 5 times to maintain the initial gap;

[0060] 5. Install and adjust the displacement sensor 14: According to the displacement sensor positioning holes on the alignment structures 5 and 6, adjust and fix the displacement detection positioning rod 13. As shown in Figure 3, make the test position in the vertical central plane, such as the test dot matrix positions A - H, and install the sensor;

[0061] The specific requirement is to pass through the vertical central plane of the caliper, and at the same time arrange 8 - point tests, which are distributed on the cylinder head and the tail claw part of the caliper body;

[0062] The cylinder head and the tail claw part of the caliper body include the outer circumference of the outer caliper, the inner circumference of the outer caliper, the outer circumference of the inner caliper, and the inner circumference of the inner caliper;

[0063] Particularly, the installation of the sensors on the inner and outer brake block backplates is fixed on the brake backplate extension supports 7 and 8.

[0064] 6. Connect each displacement sensor 14 to a multi-channel data acquisition analyzer (more than 8 channels). After adjusting and installing the displacement sensor to the zero position, use the fastening bolt 10 to fix the displacement detection positioning rod 13;

[0065] 7. Pressurize and test: As shown in the figure, apply the following fluid pressures at each position of A - H and measure the displacement in the piston sliding direction. Pressure: 0.5, 1 - 12 MPa (per 1 MPa);

[0066] 8. Collect and transmit the data of each test position;

[0067] 9. Data processing: Through the multi-channel data acquisition instrument, establish the relationship diagrams between the caliper displacement and the fluid pressure; the relationship diagram between the deformation of the brake block backplate and the fluid pressure.

[0068] Output single-point hydraulic pressure & deformation. Optionally, the evaluation first adopts single-point hydraulic pressure & deformation evaluation, and respectively form hydraulic pressure & deformation curves for each point of A, B, C, D... H;

[0069] Output the comprehensive evaluation of the deformation of the vertical central plane of the caliper body and the vertical central deformation of the inner and outer brake backplates, and form a hydraulic pressure & deformation curve. Deformation of the vertical central plane of the caliper body, caliper deformation amount = (|displacement E - displacement H|) - (|displacement A - displacement D|); Deformation of the vertical central plane of the brake backplate, inner and outer backplate deformation = (|displacement F - displacement G|) - (|displacement B - displacement C|).

[0070] Specific Embodiment 2

[0071] Test the brake caliper assembly with mounting hole spacing of 160, mounting surface to brake surface center distance of 35, disc diameter of 380, and disc thickness of 28:

[0072] 1. Clamping and automatic alignment: According to the installation hole distance of the test part, use the adjustable fixture 4 to adjust the docking installation hole distance to 160;

[0073] 2. According to the distance of 35 from the caliper mounting surface to the brake surface, use the adjustable pad 3 to adjust the distance to 35 to match the center distance;

[0074] 3. According to the different large arcs of the caliper body and the opening of the claws, adapt to the 380×28 simulated brake disc 2 to complete the installation of the brake caliper assembly;

[0075] 4. Execute steps 4-9 of specific embodiment 1 to complete the test.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A hydraulic stiffness test device for a brake caliper, characterized in that: It includes an installation platform, adjustable alignment structures symmetrically arranged at both ends of the installation platform, and a clamping structure and a simulation disc located between the two alignment structures; The two alignment structures are arranged at both ends of the installation platform in an adjustable manner along the X direction through connecting bolts. Each alignment structure is provided with a sensor positioning hole and a displacement detection positioning rod that can slide along the Y direction. The displacement detection positioning rod is fixed by a side fastening bolt; The clamping structure includes an adjustable cushion block and an adjustable fixture. The adjustable cushion block adjusts the distance between the test piece installation surface and the braking surface along the X direction through a mother-daughter cushion block structure; the adjustable fixture is provided with a bolt hole that slides along the Y direction for adapting test pieces with different installation hole distances; Among them, the sensor positioning hole of the alignment structure is centered with the center of the clamping structure to form a vertical central plane, and the X direction and the Y direction are orthogonal.

2. The hydraulic stiffness test device for a brake caliper according to claim 1, characterized in that: The simulation disc is installed on the installation platform in a quick-change manner to adapt to test pieces with different disc diameters and disc thicknesses.

3. The hydraulic stiffness test device for a brake caliper according to claim 1, wherein: The test device further includes a pressure regulation system and a displacement sensor multi-channel data transmission and analysis system; The pressure regulation system includes a liquid storage tank, a pressure regulation gauge and a flow meter, and is connected to the test piece through a hydraulic pipeline; the multi-channel data acquisition and analysis system includes a displacement sensor, a multi-channel data acquisition analyzer and a computer.

4. The hydraulic stiffness testing device for a brake caliper according to claim 3, wherein: The displacement sensor is installed on the displacement detection positioning rod; the multi-channel data acquisition analyzer is connected to all displacement sensors through signal lines; the computer communicates with the multi-channel data acquisition analyzer to process data.

5. A hydraulic stiffness test device for a brake caliper according to claim 1, characterized in that: After the displacement detection positioning rod of the alignment structure is locked by a fastening bolt, the displacement sensor connected to its end is arranged at the following test points: The outer circumference A of the outer caliper of the caliper cylinder head, the outer circumference B of the outer back plate, the outer circumference D of the inner caliper, and the outer circumference C of the inner back plate; The inner circumference E of the outer caliper of the caliper claw part, the inner circumference F of the outer back plate, the inner circumference G of the inner back plate, and the inner circumference H of the inner caliper.

6. The hydraulic stiffness test device for a brake caliper according to claim 1, characterized in that: The Y-direction adjustment range of the adjustable fixture includes 140mm, 160mm, 170mm, and is locked after being aligned with the test piece installation hole through the sliding bolt hole.

7. A method for testing the hydraulic stiffness of a brake caliper, which applies a brake caliper hydraulic stiffness testing device as described in any one of claims 1 to 6, and the test specimen is a brake caliper, characterized in that, It includes the following steps: S1, clamping and adjustment step: Adjust the Y-direction installation hole distance of the test piece through the adjustable fixture, adjust the distance from the X-direction installation surface of the test piece to the brake disc through the adjustable cushion block, adapt to different disc diameters and disc thicknesses through the simulation disc, and clamp the test piece; S2, sensor positioning step: Adjust the position of the displacement sensor through the displacement sensor positioning hole on the alignment structure; And adjust the X-direction position of the displacement sensor connecting rod to make the test position in the vertical central plane; S3, pressurized test step: Apply fluid pressures of 0.5MPa and 1 - 12MPa respectively at each test point of A - H of the test piece, and collect the displacement data of each test point in real time through the multi-channel data acquisition analyzer; S4, data processing step: According to the deformation corresponding to each pressure, establish a relationship diagram between the caliper displacement and the fluid pressure and a relationship diagram between the deformation amount of the brake block back plate and the fluid pressure.

8. A method for testing the hydraulic stiffness of a brake caliper according to claim 1, characterized in that: The test evaluation forms a system: Adopt single-point hydraulic & deformation, caliper center vertical plane deformation and inner and outer brake back plate center vertical deformation to form a comprehensive evaluation and form a hydraulic & deformation curve.

9. A method for testing the hydraulic stiffness of a brake caliper according to claim 8, characterized in that: The evaluation system first uses single-point hydraulic & deformation evaluation to form hydraulic & deformation curves for points A, B, C, D﹍﹍H one by one; then comprehensively evaluates the deformation of the vertical plane at the center of the clamp body, where the deformation of the clamp body = (|displacement E - displacement H|) - (|displacement A - displacement D|); and the deformation of the vertical plane at the center of the brake backplate, where the deformation of the inner and outer backplates = (|displacement F - displacement G|) - (|displacement B - displacement C|).

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