Device and method for measuring drag torque of electronic mechanical brake caliper assembly

Abstract

The present invention discloses a device and method for measuring the drag torque of an electronic mechanical brake caliper assembly, which belongs to the technical field of automobile brake system testing. The device includes a first support seat, an active rotating shaft, a brake disc and a driven rotating shaft assembly with a torque sensor, and the precise positioning of the caliper support is achieved through the cooperation of a rotating clamp and a guide pin. During the test, the caliper first clamps the brake disc to output the clamping force and then relieves the pressure. After the motor drives the brake disc to rotate one circle to eliminate the inertia torque, the torque sensor dynamically collects the drag torque. A modular brake disc fixing seat is used to adapt to products of different specifications, the coupling compensates for the shaft system offset, the fixed block locking mechanism ensures the safety of the non-measurement state, and the dynamic and static friction separation measurement method is combined to eliminate the inertia error. This solution solves the problems of positioning deviation, mechanical interference and friction interference in traditional testing, and significantly improves the measurement accuracy and efficiency of the brake caliper drag torque.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile brake system testing, and in particular to a device and method for measuring the drag torque of an electronic mechanical brake caliper assembly. Background Art

[0002] With the accelerating evolution of vehicle electrification and intelligent technology, traditional electronic parking brake (EPB) systems struggle to meet the stringent braking system response speed, energy efficiency, and control precision requirements of advanced autonomous driving. EPB systems rely on hydraulic lines to transmit braking force, resulting in significant response delays and the risk of brake fluid leakage, making them difficult to integrate with drive-by-wire chassis. After EPB release, elastic deformation of the seal and residual mechanical return clearance often result in drag torque exceeding 3.5 N·m, causing energy loss and brake disc overheating. The separate design of the hydraulic unit and electronic control module increases weight by 30%-40%, limiting the range of new energy vehicles. With the advancement of automotive electronics, electromechanical braking (EMB) systems are becoming an industry trend due to their advantages of fast response and high control precision. Brake drag, a key indicator of brake system performance, is directly related to abnormal brake pad wear, increased vehicle energy consumption, and brake system lifespan. Traditional mechanical braking systems release the brakes by releasing pressure through hydraulic lines, while electromechanical brake calipers drive the actuator via electronic control signals. This presents new technical challenges in measuring the drag torque after the brakes are released.

[0003] The current industrialization of EMB calipers faces the dual challenges of testing standards and process verification systems. Traditional hydraulic brake test benches rely on closed-loop hydraulic pressure control, while EMB calipers receive digital commands via the CAN bus. There are generational differences in the signal interface protocols between the two. The lag in the development of industry standards also urgently needs to be addressed. In October 2024, China Automotive Research Institute and Fige Technology jointly issued the country's first group standard, "Performance Requirements and Bench Test Methods for Passenger Vehicle Electronic Mechanical Brake Caliper Assemblies." The automotive industry is now in urgent need of research on the drag torque device and test methods for electronic mechanical brake caliper assemblies. Summary of the Invention

[0004] The purpose of the present invention is to provide a device and method for accurately measuring the drag torque of an electronic mechanical brake caliper, so as to solve the measurement deviation problem caused by factors such as positioning error and inertial interference in traditional testing.

[0005] An electronic mechanical brake caliper assembly drag torque measurement device includes a first support base and a first support frame. A driving shaft is positioned within the first support base, connected to a brake disc. A caliper is positioned around the outer periphery of the brake disc. The caliper is mounted on a caliper support, which can be secured to a driven shaft assembly. The driven shaft assembly is connected to a torque sensor. The caliper support has a support notch at its center, into which a rotating clamp extends. The rotating clamp is driven by a cylinder and secures the caliper support to a reference fixing plate. A guide pin is positioned within a hole in the reference fixing plate and can be driven by a drive device. Brake drag refers to the phenomenon in which a vehicle's brakes fail to release immediately or completely after the driver fully releases the brake pedal, resulting in a considerable amount of drag torque remaining. This test device is used to test brake disc drag torque. Initially, the caliper clamps the brake disc. After a period of time, the caliper releases pressure, and the active shaft begins to rotate, driving the brake disc. This creates a certain drag torque on the caliper, which ultimately transmits force to the caliper support assembly. The caliper support, in turn, transmits force to the driven shaft assembly. A torque sensor reads the torque on the driven shaft assembly, thereby determining the drag torque generated by the brake disc over a specific period of time. The first support bracket houses the active shaft, while the second support bracket stabilizes the torque sensor. The caliper is connected to the caliper support bracket via a transition sleeve, allowing the caliper bracket to be easily moved and grasped by a handling mechanism to a desired location. The rotating clamp is driven by a pneumatic cylinder, which is supported by three cylinder brackets. The cylinder drives the rotating clamp, which rotates to position the caliper support bracket against a reference plate. The reference plate and guide pins precisely locate the caliper support bracket, ensuring the caliper is positioned for testing. A drive mechanism moves the guide pins horizontally.

[0006] The drag torque measuring device for an electronic mechanical brake caliper assembly comprises a driven shaft assembly, which is mounted within a second support seat. One end of the driven shaft is coaxially connected to the torque sensor, and the other end is secured with three pneumatic cylinder brackets, two of which are further connected to a reference fixing plate at their other ends. A drive unit is mounted on the side of the second support seat and comprises a pneumatic push rod and a pull plate. The pneumatic push rod's extension and contraction direction is parallel to the guide pin axis. The edge of the pull plate is provided with a notch that mates with the guide pin, and a return spring is provided within the guide pin. A drive unit is located on each side of the second support seat. When the caliper support is to be moved to a specified position, the pneumatic push rod drives the pull plate to move horizontally toward the sensor, which in turn drives the pin baffle to move horizontally toward the sensor to prevent interference and collision with the caliper support during movement. After the caliper support moves to the specified position, the pneumatic push rod pushes the pull plate to drive the pin baffle to move horizontally toward the side of the brake disc. The guide pin will pass through the hole at the corresponding position of the reference fixing plate due to the action of the reset spring, and finally extend into the support positioning hole of the caliper support, thereby accurately positioning the caliper support. The guide pins on both sides of the second support seat prevent the caliper support from shifting, making it convenient to fix the position of the caliper support with the rotating clamp later.

[0007] The drag torque measuring device of the electronic mechanical brake caliper assembly has a support positioning hole on the caliper support, and the guide pin can be extended axially into the support positioning hole. The rotating clamp is shown in the figure, which is in a loose state when placed vertically and in a locked state when placed horizontally. When the caliper support is attached to the reference fixing plate by the transport device, the rotating clamp is in a loose state and passes through the support gap. The guide pins on both sides of the second support are extended into the support positioning holes under the action of the internal return spring to position the caliper support. The rotating clamp is then rotated to lock the caliper support to the reference fixing plate. The guide pins are then pulled out of the support positioning holes, and the transport device unloads the force. The caliper will be subjected to drag torque during the test, and the drag torque will be transmitted to the caliper support. The guide pins are pulled out of the support positioning holes to avoid affecting the measurement of the drag torque.

[0008] The drag torque measurement device for an electronic mechanical brake caliper assembly connects the drive shaft to the brake disc holder via a transition sleeve. A keyway is provided between the transition sleeve and the disc holder to maintain coaxiality. The test device is designed to accommodate brake discs of varying sizes, each corresponding to a disc holder of varying sizes. The disc holder is easily removable and reinstallable from the transition sleeve. The transition sleeve acts as an intermediary component, bridging the diameter difference between the drive shaft and the disc holder, ensuring a reliable connection.

[0009] The drag torque measuring device of the electronic mechanical brake caliper assembly has a fixed block threadedly connected to the end of the active shaft, a sliding groove is provided in the middle of the fixed block, a sliding block is embedded in the sliding groove, the sliding block slides with the side wall of the first support seat, and the sliding block is locked by a knob; the fixed block is used to fix the active shaft in the non-measuring state to prevent the active shaft from being offset due to gravity or vibration, resulting in deviation from the initial position of the brake disc and the caliper. In the non-working state, the sliding block is inserted into the notch of the fixed block and is locked by the knob to ensure that the active shaft does not rotate in the non-working state, ensuring the safety of the operator in the non-working state. Other personnel can observe the status of the knob to determine whether the device is in the pre-working state, which is convenient for personnel to manage and check the equipment.

[0010] The drag torque measurement device for an electronic mechanical brake caliper assembly features a motor mounted on the first support frame. The motor has an output shaft, which is connected to the drive shaft via a coupling. The coupling smoothly transmits power from the motor output shaft to the drive shaft, ensuring proper operation of the entire device. Due to manufacturing and installation errors, as well as factors such as thermal expansion and vibration during operation, axial, radial, or angular misalignment may occur between the two shafts. The coupling compensates for these misalignments, ensuring proper connection and power transmission between the two shafts.

[0011] The drag torque measuring device of the electronic mechanical brake caliper assembly has a power port on the caliper, which is used to receive an external control signal to drive the clamping or releasing action of the caliper. When the caliper releases the brake disc, the brake disc can rotate freely under the drive of the active shaft, and the drag torque of the caliper is measured by the torque sensor.

[0012] The drag torque measurement device for an electronic mechanical brake caliper assembly has a movable plate connected to the threaded bottom of the first support base and the first support frame. The movable plate has positioning holes, which connect it to the base plate through the positioning holes. The base plate has corresponding connecting holes. The base plate's connecting holes are designed and calculated. By connecting the positioning holes and the base plate's connecting holes with screws according to their positions, the position of the first support base and the first support frame can be adjusted, ultimately aligning the central axes of the driving and driven shafts, ensuring the experimental accuracy of the test device.

[0013] The method for measuring the drag torque of an electromechanical brake caliper assembly involves: first, activating the drive mechanism to move the guide pin out of the reference plate, allowing the caliper mount to engage the reference plate. Releasing the drive mechanism allows the guide pin to return to its original position and extend into the caliper mount. Second, the rotating clamp is controlled to rotate and lock the caliper mount to the reference plate. Third, the caliper assembly is controlled to apply clamping force, which is then released to zero pressure after 5 seconds of clamping. Fourth, the motor is activated to drive the active shaft to rotate the brake disc. Fifth, after the brake disc begins stable rotation, the maximum drag torque during the first and tenth revolutions is measured and recorded using a torque sensor. The torque sensor data recorded during the first revolution actually records the static torque of the brake disc during vehicle start-up. EMB calipers rely on an external motor to drive the friction pads to clamp or release the brake disc. The drag torque during the first revolution directly reflects the efficiency of the external motor's reverse return. If the external motor's control signal is delayed or there is backlash in the mechanical transmission, the friction pads may not fully disengage from the brake disc, resulting in significantly exceeded torque during the first revolution. EMB calipers rely on a mechanical drive (such as a ball screw or rack-and-pinion mechanism) to return the piston, rather than the elastic rebound of the seals in a hydraulic system. The first rotation data verifies that the screw's reverse motion is in place and that the initial clearance between the friction pad and the brake disc is maintained. The torque sensor data recorded during the 10th rotation test verifies the stability of the caliper system after repeated cycles. The caliper's friction pads may gradually lose contact due to vibration or centrifugal force generated by the rotation of the brake disc. The 10th rotation data verifies the effectiveness of this self-adjusting capability. Continuous rotation of the brake disc may slightly increase the temperature, causing thermal expansion or plastic deformation of metal components. Excessive drag torque during the 10th rotation can indicate such a problem. EMB calipers typically feature automatic compensation for friction pad wear. Ten consecutive rotations verify whether the compensation mechanism is overadjusting under dynamic conditions (e.g., the compensation screw accidentally locking), resulting in insufficient clearance between the friction pad and the brake disc. This can be detected by observing the test data. A drag torque value below 2 N·m is generally normal.

[0014] The advantages of the present invention are: through the coordinated positioning mechanism of the rotating clamp and the guide pin, combined with the reference fixing plate and the drive device, the precise positioning and rapid locking of the caliper support are achieved, avoiding measurement errors caused by positioning deviation during the test process. At the same time, the removable design of the guide pin effectively eliminates its interference with torque transmission, ensuring the accuracy of data collection. The modular structural design, such as the transition sleeve and keyway matching, and the replaceable brake disc fixing seat, significantly improves the device's compatibility with brake discs of different sizes and enhances the versatility of testing. The test method collects dynamic friction state data after one rotation, effectively avoiding the interference of static friction and inertia torque. Combined with the coaxial connection between the torque sensor and the driven shaft, it further optimizes measurement accuracy. The overall device has a compact structure and flexible adjustment. The adjustable support seat position design ensures the centration of the active and driven shafts, and the automatically controlled pneumatic drive and caliper power port achieve efficient coordination of the test process. While improving test efficiency, it provides a high-precision solution for the standardized evaluation of brake system drag torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0016] Figure 1 Schematic diagram of the overall device of the measuring device of the present invention.

[0017] Figure 2 It is a side view of the measuring device of the present invention.

[0018] Figure 3 It is a schematic diagram of the caliper and caliper support of the present invention.

[0019] Figure 4 It is a schematic diagram of the driven shaft assembly and guide pin of the present invention.

[0020] Figure 5 This is a schematic diagram of the guide pin of the present invention extending into the positioning hole of the support, and the reference fixing plate is not shown in the figure.

[0021] Figure 6 This is a schematic diagram of the caliper support of the present invention being installed on the driven shaft assembly.

[0022] Figure 7 This is a partially enlarged schematic diagram of the connection between the active rotating shaft and the brake disc of the present invention.

[0023] Description of the drawings: 1-first support seat, 2-first support frame, 3-brake disc, 4-driven rotating shaft assembly, 5-caliper support, 6-second support frame, 7-second support seat, 8-driving device, 9-guide pin, 11-driving rotating shaft, 12-transition connecting sleeve, 13-brake disc fixing seat, 14-fixed block, 15-sliding block, 16-knob, 21-motor, 22-coupling, 23-movable plate, 24-base plate, 41-driven rotating shaft, 42-cylinder, 421-rotating clamp, 422-cylinder fixing bracket, 43-reference fixing plate, 51-support notch, 52-support positioning hole, 53-caliper, 54-power port, 55-transition sleeve, 61-torque sensor, 81-pneumatic push rod, 82-pull plate, 91-pin baffle, 211-motor output shaft, 231-positioning hole. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1:

[0026] Refer to the attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 , Attachment Figure 4 , Attachment Figure 6 As shown, the electronic mechanical brake caliper assembly drag torque measuring device includes a first support seat 1 and a first support frame 2. A driving shaft 11 is placed in the first support seat 1, and the driving shaft 11 is connected to the brake disc 3. A caliper 53 is provided on the periphery of the brake disc 3. The caliper 53 is mounted on the caliper support 5. The caliper support 5 can be fixed on the driven shaft assembly 4. The driven shaft assembly 4 is connected to the torque sensor 61. A support notch 51 is provided in the center of the caliper support 5. The support notch 51 can be extended into the rotating clamp 421. The rotating clamp 421 is driven by the cylinder 42 and fixes the caliper support 5 on the reference fixing plate 43. A guide pin 9 is provided in the hole of the reference fixing plate 43, and the guide pin 9 can be driven by the driving device 8.

[0027] Refer to the attached Figure 1 , Attachment Figure 2 , Attachment Figure 4 , Attachment Figure 5 , Attachment Figure 6As shown, this testing device is used to test the drag torque of the brake disc 3. In the initial stage, the caliper 53 clamps the brake disc 3. After a period of time, the caliper 53 releases pressure, and the driving shaft 11 begins to rotate, driving the brake disc 3. The caliper 53 receives a certain amount of drag torque, which is ultimately transmitted to the caliper support 5. The caliper support 5 then transmits the force to the driven shaft assembly 4. The torque sensor 61 is used to read the torque value on the driven shaft assembly 4, thereby obtaining the drag torque data generated by the brake disc 3 over a certain period of time. The first support 1 is used to place the driving shaft 11, and the second support 6 is used to stabilize the torque sensor 61. The caliper 53 is connected to the caliper support 5 via a transition sleeve 55, which facilitates the caliper support 5 to be transported and grasped to a designated location by a handling mechanism. The rotating clamp 421 is driven by the cylinder 42 and can rotate to position the caliper support 5 on the reference fixing plate 43. The reference fixing plate 43 and the guide pin 9 are used to accurately locate the position of the caliper support 5 to ensure that the caliper 53 is installed in the specified position for testing. The driving device 8 is used to move the guide pin 9 in the horizontal direction.

[0028] Refer to the attached Figure 2 , Attachment Figure 3 , Attachment Figure 4 , Attachment Figure 6 As shown, the drag torque measurement device for an electronic mechanical brake caliper assembly comprises a driven shaft assembly 41 mounted within a second support base 7. One end of the driven shaft 41 is coaxially connected to the torque sensor 61, while the other end is secured with three pneumatic cylinder brackets 422, which are in turn connected to a reference fixing plate 43. A drive device 8 is mounted on the side of the second support base 7 and comprises a pneumatic push rod 81 and a pull plate 82. The pneumatic push rod 81 extends and retracts parallel to the axis of the guide pin 9. The edge of the pull plate 82 is provided with a notch that mates with the guide pin 9, and a return spring is incorporated into the guide pin 9. There is a drive device 8 on each side of the second support base 7. When the caliper support 5 is to be moved to a desired position, the pneumatic push rod 81 drives the pull plate 82 to move horizontally toward the torque sensor 61. The pull plate 82 then drives the pin stopper 91 to move horizontally toward the torque sensor 61, preventing interference or collision with the caliper support 5 during movement. After the caliper support 5 moves to the specified position, the pneumatic push rod 81 pushes the pull plate 82 to drive the pin baffle 91 to move horizontally toward the side of the brake disc 3. The guide pin 9 will extend into the support positioning hole 52 of the caliper support 5 due to the action of the reset spring, thereby accurately positioning the caliper support 5. The guide pins 9 on both sides of the second support seat 7 prevent the caliper support 5 from shifting, making it convenient to rotate the clamp 421 to fix the position of the caliper support 5.

[0029] Refer to the attached Figure 3 , Attachment Figure 4 , Attachment Figure 6As shown in FIG. 1 , the drag torque measuring device of the electronic mechanical brake caliper assembly is provided with a support positioning hole 52 on the caliper support 5, and the guide pin 9 can be extended into the support positioning hole 52 along the axial direction. Figure 6 As shown, vertical orientation indicates a loosened state, while horizontal orientation indicates a locked state. When the caliper support 5 is placed against the reference fixing plate 43 using a handling device, the rotating clamp 421 is loosened and passes through the support notch 51. The guide pins 9 on both sides of the second support 7, under the action of internal return springs, extend into the support positioning holes 52 to position the caliper support 5. The rotating clamp 421 then rotates to lock the caliper support 5 to the reference fixing plate 43. The guide pins 9 are then withdrawn from the support positioning holes 52 under the action of the drive device 8, and the handling device unloads the force. During testing, the caliper 53 will be subjected to a drag torque, which will be transmitted to the caliper support 5. The guide pins 9 are withdrawn from the support positioning holes 52 to avoid affecting the measurement of the drag torque.

[0030] Refer to the attached Figure 1 , Attachment Figure 7 As shown, the drag torque measurement device for an electronic mechanical brake caliper assembly has a driving shaft 11 connected to a brake disc holder 13 via a transition sleeve 12. A keyway is provided between the transition sleeve 12 and the brake disc holder 13 to maintain coaxiality. During testing, the test device needs to test brake discs 3 of different sizes, corresponding to brake disc holders 13 of different sizes. The brake disc holder 13 is easily removable and reinstallable from the transition sleeve 12. The transition sleeve 12 acts as an intermediary component, bridging the diameter difference between the driving shaft 11 and the brake disc holder 13, achieving a reliable connection.

[0031] Refer to the attached Figure 7 As shown, the drag torque measuring device of the electronic mechanical brake caliper assembly has a fixed block 14 threadedly connected to the end of the active shaft 11, a sliding groove is provided in the middle of the fixed block 14, a sliding block 15 is embedded in the sliding groove, the sliding block 15 slides with the side wall of the first support seat 1, and the sliding block 15 is locked by the knob 16; the fixed block 14 is used to fix the active shaft 11 in the non-measuring state to prevent the active shaft 11 from being offset due to gravity or vibration, resulting in the initial position deviation of the brake disc 3 and the caliper 53. In the non-working state, the sliding block 15 is inserted into the notch of the fixed block 14 and is locked by the knob 16 to ensure that the active shaft 11 will not rotate in the non-working state, thereby ensuring the safety of the operator in the non-working state. Other personnel can observe the state of the knob 16 to determine whether the device is in the pre-working state, which is convenient for personnel to manage and check the equipment.

[0032] Refer to the attached Figure 1As shown, the drag torque measurement device for an electronic mechanical brake caliper assembly has a motor 21 fixed to the first support frame 2. Motor 21 has a motor output shaft 211. Motor output shaft 211 and driving shaft 11 are connected together by a coupling 22. Coupling 22 smoothly transmits power from motor output shaft 211 to driving shaft 11, ensuring the normal operation of the entire device. Due to manufacturing and installation errors or factors such as thermal expansion and vibration during operation, axial, radial, or angular offsets may occur between the two shafts. Coupling 22 can compensate for these offsets, ensuring proper connection and power transmission between the two shafts.

[0033] Refer to the attached Figure 2 As shown, the drag torque measuring device of the electronic mechanical brake caliper assembly, the caliper 53 is provided with a power port 54, the power port 54 is used to receive an external control signal to drive the clamping or loosening action of the caliper 53, the clamping and loosening principle of the caliper 53 can refer to the disclosed technology CN119412450A; when the caliper 53 releases the brake disc 3, the brake disc 3 can rotate freely under the drive of the active shaft 11, and the drag torque of the caliper 53 will be transmitted to the torque sensor 61 for measurement.

[0034] Refer to the attached Figure 1 As shown, in the drag torque measurement device for an electronic mechanical brake caliper assembly, the first support seat 1 and the first support frame 2 are threadedly connected to a movable plate 23 at their bottom ends. The movable plate 23 is provided with positioning holes 231, which connect the movable plate 23 to the base plate 24 through the positioning holes. The base plate 24 has connecting holes corresponding to the positioning holes 231. The connecting holes in the base plate 24 are designed through calculation. By sequentially connecting the positioning holes 231 and the base plate connecting holes with screws according to their positions, the positions of the first support seat 1 and the first support frame 2 can be adjusted, ultimately aligning the central axes of the driving shaft 11 and the driven shaft 41, thereby ensuring the experimental accuracy of the test device.

[0035] Example 2:

[0036] Refer to the attached Figure 1 , Attachment Figure 2 , Attachment Figure 3 , Attachment Figure 4 , Attachment Figure 6 As shown, the drag torque measurement method of the electronic mechanical brake caliper assembly based on the device of Example 1 refers to the automotive industry standard QC / T592 Passenger Car Brake Caliper Assembly Performance Requirements and Bench Test Methods.

[0037] First, start the pull plate 82 of the driving device 8 to drive the guide pin 9 to move out of the reference fixing plate 43, and the external transport device moves the caliper support 5 to fit the reference fixing plate 43, and release the pull plate 82 of the driving device 8, so that the guide pin 9 can be reset by its internal spring and extend into the caliper support 5 for positioning; second, start the cylinder 42 to control the rotation of the rotating clamp 421 and lock the caliper support 5 to the reference fixing plate 43; third, control the caliper assembly to output the clamping force, and release the pressure to zero after clamping for 5s; fourth, start the motor 21 to drive the active rotating shaft 11 to drive the brake disc 3 to rotate; fifth, after the brake disc 3 starts to rotate, measure and record the data of the torque sensor 61 during the first and tenth rotations through the torque sensor 61. The clamping and loosening principles of the caliper 53 can be found in the published technology CN119412450A. During testing, the caliper 53 is affected by drag torque, which is transmitted from the caliper 53 to the caliper support 5 and the driven shaft 41, and ultimately read by the torque sensor 61. From the initial stationary state to the start of rotation, the static friction between the brake disc 3 and the friction pad of the caliper 53 is relatively high. Once the brake disc 3 stabilizes, the system enters a stable dynamic friction state, where the measured torque is closer to the dynamic friction torque experienced during actual vehicle operation.

[0038] The data from torque sensor 61 during the first test cycle actually records the static torque of brake disc 3 during vehicle startup. The EMB caliper 53 relies on an external motor to drive the friction pads to clamp or release the brake disc 3. The drag torque during the first cycle directly reflects the efficiency of the external motor's reverse return. If the external motor's control signal is delayed or there's backlash in the mechanical transmission, the friction pads may not fully disengage from the brake disc 3, significantly exceeding the specified torque during the first cycle. The piston return of the EMB caliper 53 relies on a mechanical drive (such as a ball screw or rack-and-pinion mechanism) rather than the elastic rebound of the seals in a hydraulic system. The data from the first cycle can verify that the reverse motion of the screw is in place and that the initial separation gap between the friction pads and the brake disc meets the specified value. The purpose of recording the torque sensor 61 data at the 10th rotation test is to verify the stability of the caliper 53 system after repeated operation. The friction pads of the caliper 53 may gradually lose contact due to vibration or centrifugal force generated by the rotation of the brake disc 3. The 10th rotation data verifies the effectiveness of this self-adjusting capability. Continuous rotation of the brake disc 3 may slightly increase the temperature, causing thermal expansion or plastic deformation of metal components. If the drag torque exceeds the specified value at the 10th rotation, this problem may be reflected. EMB calipers 53 typically have automatic compensation for friction pad wear. 10 consecutive rotations verify whether the compensation mechanism is over-adjusted under dynamic conditions (such as accidental locking of the compensation screw), resulting in insufficient clearance between the friction pad and the brake disc. This can be verified by observing the test data. Generally, a drag torque below 2 N·m is normal.

[0039] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and do not impose any form of limitation on the implementation methods of the technology of the present invention. Any person skilled in the art may make slight changes to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0040] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. An electronic mechanical brake caliper assembly drag torque measuring device, comprising a first support seat (1) and a first support frame (2), wherein a driving shaft (11) is placed in the first support seat (1), the driving shaft (11) is connected to a brake disc (3), a caliper (53) is provided on the periphery of the brake disc (3), the caliper (53) is mounted on a caliper support (5), the caliper support (5) is used to be fixed on a driven shaft assembly (4), and the driven shaft assembly (4) is connected to a torque sensor (61), characterized in that: The center of the caliper support (5) is provided with a support notch (51), and the caliper support (5) is provided with a support positioning hole (52). The support notch (51) is used to extend into a rotating clamp (421), and the rotating clamp (421) is used to fix the caliper support (5) on the reference fixing plate (43). The reference fixing plate (43) is provided with a hole for passing a guide pin (9), and the guide pin (9) can be axially extended into the support positioning hole (52). After the rotating clamp (421) fixes the caliper support (5) on the reference fixing plate (43), the guide pin (9) is driven by the driving device (8) to be pulled out from the support positioning hole (52).

2. The device for measuring the drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The driven rotating shaft assembly (4) comprises a driven rotating shaft (41), the driven rotating shaft (41) is placed in a second supporting seat (7), and one end of the driven rotating shaft (41) is coaxially connected to a torque sensor (61).

3. The device for measuring the drag torque of an electromechanical brake caliper assembly according to claim 2, characterized in that: The driving device (8) is installed on the side of the second support seat (7), and the driving device (8) includes a pneumatic push rod (81) and a pull plate (82). The telescopic direction of the pneumatic push rod (81) is parallel to the axial direction of the guide pin (9). The edge of the pull plate (82) is provided with a notch that cooperates with the guide pin (9), and a return spring is provided in the guide pin (9).

4. The device for measuring the drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The end of the guide pin (9) is connected to a pin baffle (91).

5. The device for measuring the drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The active rotating shaft (11) is connected to the brake disc fixing seat (13) via a transition connecting sleeve (12), and a keyway structure is provided between the transition connecting sleeve (12) and the brake disc fixing seat (13) to maintain coaxiality.

6. The device for measuring drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The end of the active rotating shaft (11) is threadedly connected to a fixed block (14), a sliding groove is provided in the middle of the fixed block (14), a sliding block (15) is embedded in the sliding groove, the sliding block (15) is slidably engaged with the side wall of the first support seat (1), and the sliding block (15) is locked by a knob (16).

7. The device for measuring drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The first support frame (2) is fixedly provided with a motor (21), the motor (21) having a motor output shaft (211), and the motor output shaft (211) and the driving rotating shaft (11) are jointly connected to a coupling (22).

8. The device for measuring drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The caliper (53) is provided with a power port (54), and the power port (54) is used to receive an external control signal to drive the clamping or loosening action of the caliper (53); when the caliper (53) releases the brake disc (3), the brake disc (3) can rotate freely under the drive of the active shaft (11), and the drag torque of the caliper (53) is measured by the torque sensor (61).

9. The device for measuring drag torque of an electromechanical brake caliper assembly according to claim 1, characterized in that: The first support seat (1) and the first support frame (2) are threadedly connected to a movable plate (23); the movable plate (23) is provided with a positioning hole (231); and the movable plate (23) is connected to the bottom plate (24) via the positioning hole.

10. A method for measuring the drag torque of an electromechanical brake caliper assembly based on the device of claim 7, characterized in that: S1: Start the driving device (8) to move the guide pin (9) out of the reference fixing plate (43), and the caliper support (5) is attached to the reference fixing plate (43), and release the driving device (8) to allow the guide pin (9) to return to its original position and extend into the caliper support (5) for positioning; S2: Control the rotating clamp (421) to rotate and lock the caliper support (5) so that it is fixed to the reference fixing plate (43); S3: Control the clamping force output by the caliper (53) assembly, and release the pressure to zero after clamping for 5 seconds; S4: Starting the motor (21) to drive the active shaft (11) to rotate the brake disc (3); S5: After the brake disc (3) starts to rotate, the drag torque during the first and tenth rotations is measured and recorded by the torque sensor (61).

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