A double-end-face synchronous grinding device for brake discs

Abstract

The application relates to the field of grinding processing equipment, in particular to a brake disc double-end face synchronous grinding processing equipment which comprises a rough grinding mechanism, a fine grinding mechanism, a rough grinding analysis mechanism, a fine grinding analysis mechanism, a stage control mechanism, a resonance suppression mechanism, a run-out compensation mechanism and a processing determination mechanism; the rough grinding analysis mechanism adjusts the synchronism and force balance based on the feed amount deviation and the unbalance value, the stage control mechanism switches stages based on the rough grinding residual amount and the acoustic emission root mean square value, the fine grinding analysis mechanism corrects parallelism based on the grinding dynamic ratio and the parallelism deviation, the resonance suppression mechanism suppresses coupled flutter, the run-out compensation mechanism realizes end face run-out follow-up compensation, and the processing determination mechanism ends processing based on the fine grinding residual amount and the end face run-out peak-to-peak value. Through multi-parameter real-time monitoring and dynamic regulation, the application balances the double-end face force, suppresses flutter and compensates for the end face run-out, and significantly improves the brake disc processing precision, end face parallelism and processing consistency.

Description

Technical Field

[0001] This invention relates to the field of grinding equipment, and more particularly to a synchronous grinding equipment for double-end faces of brake discs. Background Technology

[0002] As a critical safety component in automotive braking systems, the machining quality of the two friction surfaces of the brake disc directly determines braking smoothness and service life. Currently, simultaneous grinding of both ends is the mainstream process to ensure the parallelism and thickness consistency of the two ends of the brake disc. However, brake discs are typical thin-walled disc-shaped parts, characterized by large diameter, small thickness, and low rigidity. During simultaneous grinding of both ends, factors such as unbalanced grinding forces between the upper and lower grinding wheels, uneven wear of the grinding wheels, and initial runout of the workpiece end face can all lead to excessive parallelism of the two ends, thickness fluctuations, and deterioration of surface roughness, seriously affecting braking performance and driving safety.

[0003] Chinese Patent Application Publication No. CN118513864A discloses a brake disc precision turning and grinding machine. This equipment includes a bed, a turning module, and a grinding module. A robotic arm is installed on the bed for gripping the workpiece. The turning module includes a turning spindle, a rear electric spindle, a tool base, a tool holder, a double-slot upper tool holder, and a double-slot upper tool holder motor. The grinding module includes a grinding upper spindle, an upper grinding wheel motor, an upper grinding wheel, a grinding lower spindle, a lower grinding wheel motor, and a lower grinding wheel. In this invention, the turning and grinding modules are integrated into the bed. The grinding module performs synchronous grinding from top to bottom, ensuring uniform force distribution, maintaining workpiece deformation-free operation, and guaranteeing grinding precision with symmetrical and uniform patterns on both sides. The turning spindle of the turning module uses a rear-mounted direct-drive electric spindle, which effectively reduces belt wear. The double precision turning uses a separate, high-rigidity tool holder and transmission structure, resulting in higher rigidity.

[0004] However, this equipment relies solely on preset fixed parameters, lacking real-time monitoring and dynamic adjustment of the processing process. It cannot accurately switch grinding stages or effectively balance the forces on both end faces. When chatter or end face runout occurs, it cannot suppress or compensate in time, resulting in poor processing consistency. Furthermore, it is highly dependent on the initial accuracy of the equipment and the operator's experience. Therefore, there is an urgent need for a brake disc dual-end face synchronous grinding equipment that can monitor processing parameters in real time, accurately switch grinding stages based on these parameters, balance the forces on both end faces, and promptly suppress and compensate for chatter or end face runout, thereby improving the processing accuracy, end face parallelism, and surface quality consistency of the brake disc. Summary of the Invention

[0005] To address these issues, the present invention provides a brake disc dual-end face synchronous grinding equipment to overcome the problems in the prior art, such as the inability to accurately switch grinding stages according to real-time processing parameters, difficulty in balancing the forces on both ends, and inability to suppress chatter or compensate for end face runout in a timely manner, which lead to poor processing accuracy, excessive parallelism, and inconsistent surface quality of the brake disc dual-end faces.

[0006] To achieve the above objectives, the present invention provides a brake disc double-end face synchronous grinding processing equipment, comprising: The rough grinding mechanism is used to drive the upper and lower grinding wheels to grind the two end faces of the brake disc to be processed at the initial rough grinding speed and the initial rough grinding feed speed. The rough grinding analysis mechanism is used to determine whether to adjust the initial speed and feed rate of rough grinding based on the feed deviation, and to adjust the initial speed and feed rate of rough grinding corresponding to the upper or lower grinding wheel based on the imbalance value. The feed deviation is the absolute value of the feed position deviation between the upper and lower grinding wheels. The stage control mechanism is used to determine whether to enter the pre-fine grinding stage based on the amount of coarse grinding residue, and to determine whether to enter the fine grinding stage based on the root mean square value of the acoustic emission signal. The fine grinding mechanism is used to drive the upper and lower grinding wheels to grind the two end faces of the brake disc to be processed at the fine grinding initial rotation speed and the fine grinding initial feed speed; The precision grinding analysis mechanism is used to determine whether to adjust the initial precision grinding speed and initial precision grinding feed rate based on the grinding dynamic ratio, and to adjust the corresponding initial precision grinding speed and initial precision grinding feed rate of the upper or lower grinding wheel based on the parallelism deviation of the double end faces. The grinding dynamic ratio is the ratio of the normal grinding force deviation of the upper and lower grinding wheels to the torque of the drive shaft. The resonance suppression mechanism is used to determine the dual-spindle resonance coupling coefficient based on the grinding wheel spindle vibration signals obtained in the rough grinding stage and the fine grinding stage, and to determine whether resonance suppression should be performed in the corresponding grinding stage based on the dual-spindle resonance coupling coefficient. The processing determination mechanism is used to determine the end time of the finishing stage based on the remaining amount of finishing grinding and the peak value of the end face runout.

[0007] Furthermore, the stage control mechanism is also used to determine whether to enter the pre-fine grinding stage based on the fact that the amount of coarse grinding residue is less than the preset amount of coarse grinding residue. The stage control mechanism also determines to enter the fine grinding stage based on the fact that the root mean square value of the acoustic emission signal is less than the preset root mean square value of the acoustic emission signal.

[0008] Furthermore, the coarse grinding analysis mechanism is also used to determine the adjustment of the initial rotational speed and the initial feed rate of the coarse grinding based on the fact that the feed deviation is greater than the preset feed deviation.

[0009] Furthermore, the rough grinding analysis mechanism is also used to determine, based on the imbalance value being greater than a preset imbalance value, the initial rough grinding feed speeds of the upper and lower grinding wheels are adjusted simultaneously, wherein... The imbalance value is the absolute value of the difference between the axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face; Based on the comparison between the axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face, the initial roughing feed speeds of the upper and lower grinding wheels are adjusted in reverse, and the sum of the feed speed adjustments on both sides is zero.

[0010] Furthermore, the fine grinding analysis mechanism is also used to determine the adjustment of the initial fine grinding rotation speed and the initial fine grinding feed speed based on the fact that the grinding dynamic ratio is greater than the preset grinding dynamic ratio.

[0011] Furthermore, the fine grinding analysis mechanism is also used to confirm, based on the fact that the parallelism deviation value of the two end faces is greater than the preset parallelism deviation of the two end faces, that the initial feed speed of the upper grinding wheel and the lower grinding wheel is adjusted simultaneously. The parallelism deviation value of the two end faces is the absolute value of the difference between the axial position values ​​of the upper end face and the axial position values ​​of the lower end face. Based on the comparison between the axial position values ​​of the upper end face and the lower end face, the initial feed speeds of the upper and lower grinding wheels are adjusted in reverse, and the sum of the feed speed adjustments on both sides is zero.

[0012] Furthermore, the resonance suppression mechanism is also used to determine resonance suppression based on the fact that the dual-principal-axis resonance coupling coefficient is less than a preset dual-principal-axis resonance coupling coefficient, wherein, Based on the spindle vibration signals of the upper and lower grinding wheels respectively, the corresponding upper end face chatter characteristic frequencies and lower end face chatter characteristic frequencies are determined. The dual-principal-axis resonant coupling coefficient is determined based on the flutter characteristic frequencies of the upper and lower ends. Based on the comparison between the upper end face flutter characteristic frequency and the lower end face flutter characteristic frequency and the corresponding fundamental frequency, the current fine grinding speed and feed rate are adjusted.

[0013] Furthermore, the processing determination mechanism is also used to determine the end time of starting the fine grinding stage based on the fact that the fine grinding remaining amount belongs to a preset fine grinding remaining amount range and the fact that the end face runout peak value belongs to a preset end face runout peak value range. The processing determination mechanism further determines to end the fine grinding stage based on the fact that the remaining fine grinding amount is less than the lower limit of the preset fine grinding remaining amount range, or based on the fact that the peak value of the end face runout is less than the lower limit of the preset end face runout peak value range.

[0014] Furthermore, it also includes a runout compensation mechanism, which determines to perform runout compensation based on the fact that the arithmetic mean deviation of the end face runout is greater than the preset arithmetic mean deviation of the end face runout.

[0015] Furthermore, the runout compensation mechanism is also used to determine the initial feed amount of the upper or lower grinding wheel based on the fact that the instantaneous end face runout is less than the lower limit of the preset instantaneous end face runout range. The increase in the initial feed amount is positively correlated with the runout offset value. The runout compensation mechanism also determines to reduce the initial feed amount of the upper or lower grinding wheel based on the fact that the instantaneous end face runout is greater than the upper limit of the preset instantaneous end face runout range. The reduction in the initial feed amount is positively correlated with the runout difference.

[0016] Compared with the prior art, the beneficial effect of the present invention is that the processing parameters generated by the rough grinding mechanism and the fine grinding mechanism during the grinding process are transmitted in real time to the corresponding rough grinding analysis mechanism, fine grinding analysis mechanism, stage control mechanism, resonance suppression mechanism, runout compensation mechanism, and processing judgment mechanism. Each analysis mechanism determines whether to adjust the grinding parameters of the corresponding mechanism based on the analysis of the processing parameters. The rough grinding analysis mechanism adjusts the initial rotational speed and feed rate of the upper or lower grinding wheel based on the feed deviation and imbalance value, ensuring the synchronicity of feed on both sides and the balance of force on the end face during the rough grinding stage. The fine grinding analysis mechanism adjusts the initial rotational speed and feed rate of the upper or lower grinding wheel based on the grinding dynamic ratio and parallelism deviation, ensuring uniform force and parallelism during the fine grinding stage. The stage control mechanism determines the switching time from rough grinding to fine grinding based on the remaining amount of rough grinding and the root mean square value of the acoustic emission signal, avoiding processing defects caused by switching too early or too late. The resonance suppression mechanism determines whether resonance suppression should be performed in the corresponding grinding stage based on the dual-spindle resonance coupling coefficient, suppressing coupled resonance in time and ensuring the surface quality of the end face. The runout compensation mechanism performs follow-up compensation based on the arithmetic mean deviation of the end face runout and the instantaneous runout amount, significantly improving the flatness of the finished product. The processing judgment mechanism determines the end time based on the remaining amount of fine grinding and the peak value of the end face runout, realizing the safe and accurate termination of the fine grinding stage.

[0017] Furthermore, in this invention, the rough grinding analysis mechanism determines the adjustment of the initial rotational speed and initial feed rate of the rough grinding based on the feed deviation being greater than a preset feed deviation. Simultaneously, based on the imbalance value being less than or equal to a preset imbalance value, it determines that the initial feed rates of the upper and lower grinding wheels will not be adjusted simultaneously, but unilateral adjustment can still be made according to the feed deviation. Based on the imbalance value being greater than a preset imbalance value, it determines that the initial feed rates of the upper and lower grinding wheels will be adjusted simultaneously. When the imbalance value is within the limit, only the side with the faster feed is decelerated according to the feed deviation to maintain feed synchronization. When the imbalance value exceeds the limit, the feed rates on both sides are adjusted in the opposite direction simultaneously to quickly correct the force imbalance on the two end faces and prevent warping and deformation of the thin-walled brake disc.

[0018] Furthermore, in this invention, the precision grinding analysis mechanism determines the adjustment of the initial rotational speed and initial feed rate of precision grinding based on the grinding dynamic ratio being greater than a preset grinding dynamic ratio. Simultaneously, based on the parallelism deviation value of the two end faces being less than or equal to a preset parallelism deviation value, it determines that the initial feed rates of the upper and lower grinding wheels will not be adjusted simultaneously, but can still be adjusted unilaterally according to the grinding dynamic ratio. Based on the parallelism deviation value of the two end faces being greater than a preset parallelism deviation value, it determines that the initial feed rates of the upper and lower grinding wheels will be adjusted simultaneously. When the parallelism deviation value does not exceed the standard, only the side with greater force is decelerated and adjusted unilaterally according to the grinding dynamic ratio to maintain force balance. When the parallelism deviation value exceeds the standard, the feed rates on both sides are adjusted in the opposite direction simultaneously to quickly correct the parallelism deviation of the two end faces, ensuring that the parallelism of both end faces meets the standard after precision grinding.

[0019] Furthermore, in this invention, the resonance suppression mechanism determines that resonance suppression is needed when the dual-spindle resonance coupling coefficient is less than or equal to a preset dual-spindle resonance coupling coefficient. For each grinding wheel, based on the relationship between the chatter characteristic frequency and the fundamental frequency of the current grinding wheel speed (current speed divided by 60), the speed of that side is independently adjusted, and the feed rate is adjusted proportionally. This allows the suppression mechanism to be triggered promptly when the dual-spindle chatter frequencies are close and there is a risk of coupled resonance, preventing severe chatter marks or abnormal grinding wheel wear on the machined surface due to the superposition of vibration energy from both sides, significantly improving the surface quality and grinding stability of the brake disc end face.

[0020] Furthermore, in this invention, the runout compensation mechanism determines that runout compensation needs to be performed based on the fact that the arithmetic mean deviation of the end face runout is greater than a preset arithmetic mean deviation. During the compensation process, based on the comparison between the instantaneous end face runout and the preset instantaneous end face runout range, the initial feed rate is reduced when the instantaneous end face runout is greater than the upper limit value, and the initial feed rate is increased when the instantaneous end face runout is less than the lower limit value, with the adjustment range being proportional to the degree of deviation. This follow-up compensation mechanism enables the grinding wheel feed rate to follow the end face contour changes in real time, effectively suppressing the influence of brake disc end face runout on grinding accuracy and significantly improving the flatness of the finished end face and braking stability.

[0021] Furthermore, in this invention, the processing determination mechanism initiates a grinding end confirmation process when the remaining grinding amount falls within a preset remaining grinding amount range and the peak value of the end face runout falls within a preset peak value range, thus preventing premature termination due to instantaneous fluctuations. Processing continues while maintaining compensation adjustment when the remaining grinding amount exceeds the upper limit of the preset remaining grinding amount range or the peak value of the end face runout exceeds the upper limit of the preset peak value range. Grinding is immediately terminated when the remaining grinding amount falls below the lower limit of the preset remaining grinding amount range or the peak value of the end face runout falls below the lower limit of the preset peak value range, preventing over-grinding and workpiece scrap. While ensuring that both thickness and end face runout meet standards, this mechanism maximizes the protection of product dimensions and geometric tolerances, achieving precise and safe control of the grinding end time. Attached Figure Description

[0022] Figure 1 This is a block diagram of the mechanism for synchronous grinding of brake discs on both ends in an embodiment of the present invention. Figure 2 This is a flowchart illustrating the process of using the brake disc double-end face synchronous grinding equipment in an embodiment of the present invention; Figure 3 This is a logic decision diagram for adjusting the initial rotational speed and initial feed rate of the coarse grinding in an embodiment of the present invention; Figure 4 This is a logic decision diagram for adjusting the initial rotation speed and initial feed speed of fine grinding in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0024] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0025] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0026] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Please see Figure 1 As shown, it is a block diagram of the mechanism of the brake disc double-end face synchronous grinding equipment in an embodiment of the present invention.

[0028] This embodiment includes a rough grinding mechanism, a rough grinding analysis mechanism, a stage control mechanism, a fine grinding mechanism, a fine grinding analysis mechanism, a resonance suppression mechanism, and a processing judgment mechanism.

[0029] The rough grinding mechanism includes an upper spindle assembly consisting of an upper grinding wheel drive motor, an upper grinding wheel spindle, and an upper grinding wheel; a lower spindle assembly consisting of a lower grinding wheel drive motor, a lower grinding wheel spindle, and a lower grinding wheel; and an upper feed servo system and a lower feed servo system that drive the upper and lower grinding wheels respectively. After rough grinding starts, the workpiece rotation motor drives the brake disc to rotate, and the upper and lower grinding wheels rotate at a preset initial rough grinding speed and move synchronously towards both ends of the brake disc at the initial rough grinding feed speed to begin grinding. For example, the initial rough grinding speed of the upper grinding wheel is set to 2400 rpm, the initial rough grinding speed of the lower grinding wheel is set to 2400 rpm, the initial rough grinding feed speed of the upper grinding wheel is set to 120 mm / min, and the initial rough grinding feed speed of the lower grinding wheel is set to 120 mm / min.

[0030] The rough grinding mechanism integrates a data acquisition unit, including displacement sensors mounted on the upper and lower grinding wheel spindle bearing seats for real-time detection of the upper and lower grinding wheel feed positions; an accelerometer mounted on the spindle housing for acquiring spindle vibration signals; and an encoder built into the feed servo motor for feedback of feed speed and position. Additionally, a laser displacement sensor is located near the workpiece clamping device to measure the axial displacement deviation of the upper and lower end faces. The axial displacement deviation refers to the difference in axial distance between the actual spatial position of the upper and lower end faces along the grinding wheel spindle axis and the theoretical standard reference position when the workpiece is clamped and positioned in the rough grinding process. It also includes the combined positional offset formed by the workpiece's own end face runout, clamping offset, micro-deformation under force, and axial movement caused by the grinding force. This parameter characterizes the axial positioning accuracy of the workpiece end face, clamping stability, and grinding axial deformation error. The data collected by the aforementioned sensors, such as feed position, axial displacement deviation, and vibration signals, are directly transmitted to the rough grinding analysis mechanism and resonance suppression mechanism for feed deviation calculation, imbalance value determination, and chatter characteristic frequency extraction.

[0031] The rough grinding analysis mechanism is connected to the rough grinding mechanism and includes a feed deviation calculation module, an imbalance value calculation module, and an adjustment command generation module. After the rough grinding starts, the rough grinding analysis mechanism receives real-time data from the rough grinding mechanism, including the upper grinding wheel feed position, lower grinding wheel feed position, upper end face axial displacement deviation, and lower end face axial displacement deviation. The feed deviation calculation module calculates the feed deviation, which is the absolute value of the difference between the upper and lower grinding wheel feed positions, and compares it with the preset feed deviation. When the feed deviation is greater than the preset feed deviation, it determines to adjust the initial speed and initial feed rate of the rough grinding. The imbalance value calculation module calculates the imbalance value... The balance value is the absolute value of the difference between the axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face. It is compared with the preset imbalance value. When the imbalance value is less than or equal to the preset imbalance value, it is determined that the initial feed speed of the upper and lower grinding wheels will not be adjusted simultaneously, but it can still be adjusted on one side according to the feed deviation. When the imbalance value is greater than the preset imbalance value, it is determined that the initial feed speed of the upper and lower grinding wheels will be adjusted simultaneously. The adjustment command generation module calculates the feed speed adjustment amount and the speed adjustment amount proportionally according to the judgment result and the deviation size, and sends the adjustment command to the upper and lower feed servo systems and spindle drive motor of the rough grinding mechanism.

[0032] The stage control mechanism is connected to both the rough grinding mechanism and the fine grinding mechanism. It includes a pre-fine grinding judgment module, an acoustic emission monitoring module, and a fine grinding switching command module. During rough grinding, the stage control mechanism directly receives the remaining amount of rough grinding (i.e., the amount not yet removed during the rough grinding stage) measured by an online thickness measuring device installed at the grinding machine's discharge port, as well as the raw acoustic emission waveform signal collected by acoustic emission sensors installed in the hydrostatic bearings or dynamic balancing head of the upper and lower grinding wheels. This raw signal is first amplified by a preamplifier (exemplarily set to a gain of 40dB), then filtered to remove low-frequency interference, and then converted into a digital signal by an analog-to-digital converter. Finally, the signal processing system performs square, sum, average, and square root operations on the digital signal within a fixed time window, performing real-time calculations. The acoustic emission signal root mean square (RMS) value is generated. The pre-fine grinding judgment module compares the remaining amount of coarse grinding with the preset remaining amount of coarse grinding. When the remaining amount of coarse grinding is less than the preset remaining amount of coarse grinding, it determines that it has entered the pre-fine grinding stage. At this time, the coarse grinding mechanism is still working, but the RMS value of the acoustic emission signal is monitored at a higher frequency. The acoustic emission monitoring module compares the real-time calculated RMS value of the acoustic emission signal with the preset RMS value of the acoustic emission signal. When the RMS value of the acoustic emission signal is less than the preset RMS value of the acoustic emission signal and remains stable, it determines that the fine grinding switching condition is met. The fine grinding switching command module sends a stop feed command to the coarse grinding mechanism and a start command to the fine grinding mechanism accordingly. At the same time, it loads the initial fine grinding speed and the initial fine grinding feed speed parameters into the fine grinding mechanism to realize the stage switching from coarse grinding to fine grinding.

[0033] The precision grinding mechanism includes an upper spindle assembly consisting of an upper grinding wheel drive motor, an upper grinding wheel spindle, and an upper grinding wheel; a lower spindle assembly consisting of a lower grinding wheel drive motor, a lower grinding wheel spindle, and a lower grinding wheel; and an upper feed servo system and a lower feed servo system that drive the upper and lower grinding wheels respectively. After precision grinding starts, the workpiece rotation motor continues to drive the brake disc to rotate. The upper and lower grinding wheels move synchronously towards both ends of the brake disc at preset initial precision grinding speeds (lower than rough grinding speeds) and initial precision grinding feed speeds (lower than rough grinding feed speeds) to begin precision grinding. For example, the initial precision grinding speeds of the upper and lower grinding wheels are set to 1200 rpm and 60 mm / min respectively.

[0034] The precision grinding mechanism integrates its own data acquisition components, including displacement sensors mounted on the upper and lower grinding wheel spindle bearing seats to detect the feed positions of the upper and lower grinding wheels in real time; an acceleration sensor mounted on the spindle housing to collect spindle vibration signals; and an encoder built into the feed servo motor to provide feedback on feed speed and position. In addition, a high-precision laser displacement sensor is installed near the workpiece clamping device to measure the axial position values ​​of the upper and lower end faces. The axial position values ​​of the upper and lower end faces refer to the actual coordinate values ​​of the upper and lower end faces of the brake disc workpiece along the axial direction of the grinding wheel spindle, which are collected in real time with reference to the unified axial reference plane of the precision grinding equipment. This comprehensively reflects the clamping reference position of the upper and lower end faces of the workpiece, the grinding force deformation, the dynamic micro-movement and axial offset parameters. Force sensors are installed between the upper and lower grinding wheel spindles and the workpiece to collect the normal grinding force of the upper grinding wheel, the normal grinding force of the lower grinding wheel and the drive shaft torque. Several displacement sensors are arranged circumferentially on one side of the brake disc end face to collect the instantaneous value of the end face runout and the arithmetic mean deviation. The data collected by the aforementioned sensors, including feed position, axial position, normal grinding force, drive shaft torque, vibration signal, and end face runout, are directly transmitted to the fine grinding analysis mechanism, resonance suppression mechanism, runout compensation mechanism, and machining judgment mechanism. These are used for grinding dynamic ratio calculation, double end face parallelism deviation adjustment, resonance suppression, runout compensation, and determination of the end time of fine grinding.

[0035] The fine grinding analysis mechanism is connected to the fine grinding mechanism and includes a grinding dynamic ratio calculation module, a parallelism deviation calculation module, and an adjustment command generation module. After fine grinding starts, the fine grinding analysis mechanism receives real-time data from the fine grinding mechanism, including the normal grinding force of the upper grinding wheel, the normal grinding force of the lower grinding wheel, the drive shaft torque, and the axial position values ​​of the upper and lower end faces. The grinding dynamic ratio calculation module calculates the grinding dynamic ratio, which is the absolute value of the deviation of the normal grinding forces between the upper and lower grinding wheels divided by the drive shaft torque, and compares it with a preset grinding dynamic ratio value. When the grinding dynamic ratio is greater than the preset grinding dynamic ratio, the initial speed and feed rate of fine grinding are adjusted. The parallelism deviation calculation module calculates the parallelism of the two end faces. The parallelism deviation value is the absolute value of the difference between the axial position values ​​of the upper end face and the lower end face, and it is compared with the preset parallelism deviation value of the two end faces. When the parallelism deviation value is less than or equal to the preset parallelism deviation value of the two end faces, it is determined that the initial feed speed of the upper and lower grinding wheels will not be adjusted simultaneously, but it can still be adjusted on one side according to the grinding dynamic ratio. When the parallelism deviation value is greater than the preset parallelism deviation value of the two end faces, it is determined that the initial feed speed of the upper and lower grinding wheels will be adjusted simultaneously. The adjustment command generation module calculates the feed speed adjustment amount and the speed adjustment amount proportionally according to the judgment result and the deviation size, and sends the adjustment command to the upper and lower feed servo systems and spindle drive motor of the fine grinding mechanism.

[0036] The resonance suppression mechanism is connected to both the rough grinding mechanism and the fine grinding mechanism. It includes a dual-spindle resonance coupling coefficient calculation module, a chatter frequency comparison module, and a resonance suppression command generation module. During the rough grinding and fine grinding stages, the resonance suppression mechanism receives vibration signals from the upper and lower grinding wheel spindles, respectively, collected by accelerometers mounted on the upper and lower grinding wheel spindle bearing seats. The dual-spindle resonance coupling coefficient calculation module performs a fast Fourier transform on the vibration signals, extracting the frequency components with the largest amplitudes as the upper and lower grinding wheel chatter characteristic frequencies, and calculates the dual-spindle resonance coupling coefficient, which is the absolute value of the difference between the upper and lower grinding wheel chatter characteristic frequencies. The chatter frequency comparison module compares the dual-spindle resonance coupling coefficient with a preset dual-spindle resonance coupling coefficient value. When the dual-spindle resonance coupling coefficient... When the value is less than or equal to the preset dual-spindle resonance coupling coefficient, resonance suppression is determined to be required. When suppression is determined to be required, for each grinding wheel, the chatter frequency comparison module further compares the chatter characteristic frequency of that side with the fundamental frequency of the current grinding wheel speed (i.e., the current speed divided by 60). If the chatter characteristic frequency is less than the fundamental frequency, it is determined to increase the speed of that side and increase the feed rate proportionally. If the chatter characteristic frequency is greater than or equal to the fundamental frequency, it is determined to decrease the speed of that side and decrease the feed rate proportionally. The resonance suppression command generation module calculates the speed adjustment amount and feed rate adjustment amount proportionally according to the above determination results and the frequency deviation, and sends the adjustment command to the upper and lower feed servo systems and spindle drive motors of the grinding mechanism corresponding to the current grinding stage (i.e., sent to the rough grinding mechanism in the rough grinding stage and sent to the fine grinding mechanism in the fine grinding stage) to achieve resonance suppression.

[0037] The runout compensation mechanism is connected to the fine grinding mechanism and includes an end face runout evaluation module, an instantaneous runout monitoring module, and a runout compensation command generation module. During the fine grinding stage, the runout compensation mechanism receives end face runout data collected in real time from several displacement sensors circumferentially arranged on one side of the brake disc end face. The end face runout evaluation module calculates the arithmetic mean deviation of the end face runout, that is, the average value of the absolute value of the runout at each phase within one revolution, and compares it with the preset arithmetic mean deviation value of the end face runout. When the arithmetic mean deviation of the end face runout is greater than the preset arithmetic mean deviation value, it is determined that runout compensation needs to be performed. The instantaneous runout monitoring module monitors the brake disc during rotation using circumferentially arranged displacement sensors (such as laser displacement sensors, etc.). An eddy current sensor continuously acquires the instantaneous end face runout at the current phase and compares it with a preset instantaneous end face runout value. When the instantaneous end face runout is less than or equal to the preset instantaneous end face runout value, the initial feed rate is increased, with the increase proportional to the runout offset value. When the instantaneous end face runout is greater than the preset instantaneous end face runout value, the initial feed rate is decreased, with the decrease proportional to the runout difference. The runout compensation command generation module calculates the instantaneous feed rate adjustment proportionally based on the comparison results and the magnitude of the deviation, and sends the adjustment command to the upper and lower feed servo systems of the current fine grinding mechanism with a millisecond-level response speed, so that the grinding wheel feed rate follows the end face contour change in real time, realizing the follow-up compensation of end face runout.

[0038] The processing judgment mechanism is connected to the rough grinding mechanism and the fine grinding mechanism. It includes a fine grinding residual amount judgment module, an end face runout peak value judgment module, and an end command generation module. During the fine grinding stage, the processing judgment mechanism receives in real time the fine grinding residual amount measured by the online thickness measuring device installed at the grinding machine outlet, which is the residual amount that has not been removed during the fine grinding stage, and the end face runout data collected by the displacement sensor arranged circumferentially on one side of the brake disc end face and calculates the end face runout peak value, which is the difference between the maximum and minimum values ​​of the end face axial displacement within one revolution. The fine grinding residual amount judgment module compares the fine grinding residual amount with a preset fine grinding residual amount range, and the end face runout peak value judgment module compares the end face runout peak value with a preset end face runout peak value range. When the fine grinding residual amount... When the remaining amount of fine grinding falls within the preset fine grinding range and the peak value of the end face runout falls within the preset end face runout peak value range, the end time determination for the fine grinding stage is initiated. When the remaining amount of fine grinding exceeds the upper limit of the preset fine grinding range or the peak value of the end face runout exceeds the upper limit of the preset end face runout peak value range, it is determined that the fine grinding is not yet complete, and processing continues. When the remaining amount of fine grinding is less than the lower limit of the preset fine grinding range or the peak value of the end face runout is less than the lower limit of the preset end face runout peak value range, it is determined that the fine grinding stage ends immediately. Based on the determination result, the end command generation module sends "continue processing", "prepare to end", or "end immediately" commands to the fine grinding mechanism. The "end immediately" command triggers operations such as stopping the feed and rapid tool retraction to complete the grinding of a single brake disc.

[0039] Please see Figure 2 As shown, it is a flowchart illustrating the process of using the brake disc double-end face synchronous grinding equipment in an embodiment of the present invention.

[0040] S1: The rough grinding mechanism drives the upper and lower grinding wheels to grind the two end faces of the brake disc to be processed at the initial rough grinding speed and the initial rough grinding feed speed; Specifically, after receiving the start command, the rough grinding mechanism sets the initial rotational speed of the upper grinding wheel, the initial rotational speed of the lower grinding wheel, and the initial feed rate of both the upper and lower grinding wheels. The upper and lower grinding wheels are driven by independent spindle motors, rotating at the set speeds and simultaneously moving towards both ends of the brake disc at the set feed rates, thus initiating the rough grinding process. During this process, the sensors integrated into the rough grinding mechanism collect relevant processing parameters in real time and transmit these parameters to the rough grinding analysis mechanism and the stage control mechanism.

[0041] S2: The rough grinding analysis mechanism calculates the feed position deviation between the upper and lower grinding wheels as the feed amount deviation, and determines whether to adjust the initial speed and feed rate of rough grinding based on the feed amount deviation, and adjusts the initial speed and feed rate of rough grinding corresponding to the upper or lower grinding wheel based on the imbalance value. Specifically, the rough grinding analysis mechanism receives real-time data from the rough grinding mechanism regarding the feed positions of the upper and lower grinding wheels, as well as the axial displacement deviations of the upper and lower end faces. It calculates the feed deviation and imbalance value, comparing each with its respective preset threshold. If the feed deviation exceeds the preset threshold, a unilateral speed reduction adjustment is applied to the side with the larger deviation between the upper and lower grinding wheel feed positions. If the imbalance value exceeds the preset imbalance value, the initial rough grinding feed speeds of both the upper and lower grinding wheels are simultaneously adjusted in the opposite direction. Finally, the feed speed adjustment and rotational speed adjustment are calculated proportionally and sent to the upper and lower feed servo systems and the spindle drive motor of the rough grinding mechanism.

[0042] Please see Figure 3 As shown, it is a logic decision diagram for adjusting the initial rotation speed and initial feed speed of rough grinding in an embodiment of the present invention.

[0043] In a specific embodiment, to accurately determine whether to adjust the initial rotational speed and initial feed rate of the rough grinding, a preset feed deviation A0 corresponding to a feed deviation A is set. The preset feed deviation A0 is determined based on the synchronization benchmark of the upper and lower grinding wheel feed positions under ideal stable conditions in the rough grinding process under standard operating conditions. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters, and other process conditions remain stable, standard batch processing samples that have been rigorously inspected and confirmed to be free from any process disturbances or equipment abnormalities are collected. The feed positions of the upper and lower grinding wheels during the rough grinding process are detected by a displacement sensor at a fixed sampling frequency. The difference in feed positions is calculated, and the absolute value is used to form a standard feed deviation sample set. The mean and standard deviation of this sample set are calculated as the basic threshold, and A0 is set to 0.01 mm for example. The comparison process based on A and A0 is as follows: If A is less than or equal to A0, it indicates that the current upper and lower grinding wheel feed synchronization is good and the feed position deviation is within the allowable range. Therefore, it is determined not to adjust the initial speed and feed rate of rough grinding.

[0044] If A is greater than A0, it indicates that the current synchronicity of the upper and lower grinding wheels is insufficient and the feed position deviation is too large. Adjust the initial speed and feed rate of rough grinding to effectively maintain the synchronicity of the feed positions of the upper and lower grinding wheels, avoid uneven grinding allowance on both ends of the brake disc due to excessively fast or slow feed on one side, and thus prevent warping and deformation of thin-walled disc-shaped workpieces.

[0045] Meanwhile, the rough grinding analysis mechanism obtains the axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face transmitted by the rough grinding mechanism, and calculates the unbalance value.

[0046] In a specific embodiment, to accurately determine the adjustment process of the initial rough grinding speed and initial rough grinding feed rate corresponding to the upper or lower grinding wheel, a preset imbalance value B0 corresponding to an imbalance value B is set. The preset imbalance value B0 is determined based on the balance benchmark of the axial displacement deviation of the upper and lower end faces under the ideal stable state of the rough grinding process under standard working conditions. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters and other process conditions remain stable, standard batch processing samples that have been strictly inspected and confirmed to be free from any process disturbances or equipment abnormalities are collected. The axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face (relative to the ideal reference plane) during the rough grinding process are detected at a fixed sampling frequency using a laser displacement sensor or an eddy current sensor. The imbalance value is calculated to form a standard imbalance value sample set. The mean and standard deviation of this sample set are calculated as the basic threshold, and B0 is set to 0.008 mm for example. The process of comparing B and B0 is as follows: If B is less than or equal to B0, it indicates that the forces on both end faces are basically balanced and the axial displacement deviation of the end faces is within the allowable range. It is determined that the initial feed speed of the upper and lower grinding wheels should not be adjusted at the same time, but unilateral adjustment can still be made according to the feed deviation. Under the premise that the forces on the end faces are basically balanced, the feed position deviation caused by excessively fast or slow feed on one side can be quickly corrected, avoiding uneven grinding allowance. At the same time, it prevents unnecessary double-sided reverse adjustment from interfering with the already qualified end face balance state, ensuring the stability and efficiency of the rough grinding process.

[0047] In this embodiment, the following parameters are exemplarily set: axial displacement deviation of the upper end face = +0.012mm, axial displacement deviation of the lower end face = +0.005mm, upper grinding wheel feed position = 10.022mm, lower grinding wheel feed position = 10.010mm, current initial feed speed of upper grinding wheel for rough grinding = 120mm / min, initial feed speed of lower grinding wheel for rough grinding = 120mm / min, initial rotation speed of upper grinding wheel for rough grinding = 2400rpm, initial rotation speed of lower grinding wheel for rough grinding = 2400rpm, preset feed deviation A0 = 0.01mm, and preset imbalance value B0 = 0.008mm.

[0048] The imbalance value B = |0.012-0.005| = 0.007 mm. Since the imbalance value B is less than the preset imbalance value B0, it is determined that the initial feed speed of the upper and lower grinding wheels for rough grinding should not be adjusted at the same time.

[0049] The feed deviation A = |10.022−10.010| = 0.012 mm. Since the feed deviation A is greater than the preset feed deviation A0, and the feed position of the upper grinding wheel is greater than that of the lower grinding wheel, it indicates that the feed position of the upper grinding wheel is too large. Therefore, the feed speed of the upper grinding wheel should be reduced to make the feed positions of both sides more synchronized.

[0050] The adjustment range is set to be positively correlated with the amount by which the feed deviation exceeds the threshold. For example, the adjustment ratio is set to 500 mm / min per millimeter deviation; the excess amount = A − A0 = 0.012 − 0.01 = 0.002 mm; the total adjustment amount = 500 × 0.002 = 1 mm / min.

[0051] After adjustment, the new feed speed for rough grinding of the upper grinding wheel is 120−1=119mm / min, while the feed speed for rough grinding of the lower grinding wheel remains unchanged.

[0052] To maintain a constant feed per revolution while adjusting the rotation speed proportionally, the new rotation speed for rough grinding on the upper grinding wheel after adjustment is 2400 × (119 / 120) = 2380 rpm, while the rotation speed for rough grinding on the lower grinding wheel remains unchanged.

[0053] If B is greater than B0, it indicates that the current forces on both ends are unbalanced and the axial displacement deviation of the ends exceeds the allowable range. It is necessary to simultaneously adjust the initial feed speed of the upper and lower grinding wheels for rough grinding, so as to quickly correct the imbalance of forces on both sides caused by the unevenness of the initial end face of the brake disc or uneven wear of the grinding wheels, and avoid unidirectional bending or warping deformation of the thin-walled brake disc during rough grinding.

[0054] Specifically, when both the feed deviation A and the imbalance value B exceed the preset imbalance value B0, a bilateral reverse adjustment based on the imbalance value B is prioritized, with the primary goal of correcting the end-face force imbalance. This is because end-face force imbalance directly leads to warping and deformation of the thin-walled brake disc, and its harm is greater than that of feed synchronization deviation. During the bilateral reverse adjustment process, the change in bilateral feed speed already includes feed synchronization correction, eliminating the need for additional unilateral adjustment.

[0055] In this embodiment, the axial displacement deviation of the upper end face is exemplarily set to +0.015mm, the axial displacement deviation of the lower end face is -0.005mm, the initial feed speed of the upper grinding wheel for rough grinding is 120mm / min, the initial feed speed of the lower grinding wheel for rough grinding is 120mm / min, the initial rotation speed of the upper grinding wheel for rough grinding is 2400rpm, the initial rotation speed of the lower grinding wheel for rough grinding is 2400rpm, and the preset imbalance value B0 is 0.008mm. The imbalance value B = |0.015 - (-0.005) | = 0.020 mm. Since the imbalance value B is greater than the preset imbalance value B0, the initial feed speed of the upper and lower grinding wheels for rough grinding is adjusted simultaneously.

[0056] Since the axial displacement deviation of the upper end face is greater than that of the lower end face, it indicates that the upper end face is too high and the lower end face is too low. The feed speed of the upper grinding wheel should be reduced while the feed speed of the lower grinding wheel is increased to make the two end faces more balanced.

[0057] The adjustment range is set to be positively correlated with the amount by which the imbalance value exceeds the threshold. For example, the adjustment ratio coefficient is set to 500 mm / (min·mm); the excess amount = B−B0 = 0.020−0.008 = 0.012 mm; the total adjustment amount = 500×0.012 = 6 mm / min.

[0058] Since the sum of the changes in the feed rates on both sides is zero, that is, the amount by which the upper grinding wheel decreases is equal to the amount by which the lower grinding wheel increases; therefore, after adjustment, the new feed rate of the upper grinding wheel for rough grinding is 120−6=114mm / min, and the new feed rate of the lower grinding wheel for rough grinding is 120+6=126mm / min.

[0059] To maintain a constant feed per revolution and adjust the rotation speed proportionally, the new rotation speed for rough grinding of the upper grinding wheel after adjustment is 2400×(114 / 120)=2280rpm, and the new rotation speed for rough grinding of the lower grinding wheel is 2400×(126 / 120)=2520rpm.

[0060] S3: The stage control mechanism determines whether to enter the pre-fine grinding stage based on the amount remaining in the coarse grinding, and determines the timing of entering the fine grinding stage based on the acoustic emission signal; Specifically, the stage control mechanism receives the remaining amount of rough grinding (i.e., the amount not yet removed during the rough grinding stage) and the root mean square (RMS) value of the acoustic emission signal in real time. When the remaining amount of rough grinding is less than the preset remaining amount, it is determined that the process enters the preparatory fine grinding stage, and the acoustic emission monitoring frequency is increased. Then, the RMS value of the acoustic emission signal is compared with the preset RMS value. When the RMS value of the acoustic emission signal is less than the preset RMS value and remains stable, it is determined that the fine grinding switching condition is met. A stop feed command is sent to the rough grinding mechanism, and a start command is sent to the fine grinding mechanism. At the same time, the initial speed and feed rate parameters of fine grinding are loaded into the fine grinding mechanism to realize the stage switching from rough grinding to fine grinding.

[0061] In a specific embodiment, to accurately determine the moment of entering the pre-fine grinding stage, a preset rough grinding remaining amount C0 is set corresponding to a rough grinding remaining amount C. The preset rough grinding remaining amount C0 is determined based on the brake disc thickness allowance benchmark under ideal stable conditions of the rough grinding process. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters, and other process conditions remain stable, standard batch processing samples, which have been rigorously inspected and confirmed to be free from any process disturbances or equipment malfunctions, are collected. At the end of the rough grinding stage (i.e., before switching to fine grinding), the actual thickness of the brake disc is detected at a fixed sampling frequency using an online thickness measurement device. The difference between this thickness and the target finished product thickness (i.e., the remaining allowance) is calculated, forming a standard rough grinding remaining amount sample set. The mean and standard deviation of this sample set are calculated as the basic threshold, and C0 is set to 0.10 mm for example. The process of comparing C and C0 is as follows: If C is less than C0, it indicates that the current remaining amount of coarse grinding is close to the requirements of fine grinding. This determines the time to enter the pre-fine grinding stage, thereby avoiding excessive fine grinding allowance due to switching too early or insufficient fine grinding allowance due to switching too late, and ensuring a smooth transition between coarse grinding and fine grinding.

[0062] If C is greater than or equal to C0, it indicates that the remaining amount of coarse grinding is still relatively large, and coarse grinding needs to continue. The time to determine when not to enter the preparatory fine grinding stage should be determined.

[0063] In a specific embodiment, to accurately determine the moment of entering the fine grinding stage, a preset root mean square (RMS) value D0 corresponding to the RMS value D of the acoustic emission signal is set. The preset RMS value D0 is determined based on the acoustic emission characteristics of the rough grinding process under standard operating conditions in an ideal stable state, suitable for switching to fine grinding. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters, and other process conditions remain stable, standard batch samples that have been rigorously inspected and confirmed to be free of any process disturbances or equipment malfunctions and have completed rough grinding and are about to enter the fine grinding stage are collected. During the pre-fine grinding stage, acoustic emission signals from the grinding zone are collected using an acoustic emission sensor at a fixed sampling frequency, and their RMS values ​​are calculated to form a standard acoustic emission sample set. The mean and standard deviation of this sample set are used as the basic threshold, exemplarily set to D0 = 0.15 V. The process of comparing D and D0 is as follows: If D is less than D0, it indicates that the current grinding process is stable and the grinding wheel is sharp. This determines the time to enter the fine grinding stage, ensuring that the process is stable and the grinding wheel is sharp. This avoids defects such as burns and chatter marks on the fine grinding surface caused by grinding wheel dulling, chattering, or insufficient cooling.

[0064] If D is greater than or equal to D0, it indicates that the current grinding process is unstable, and the moment to stop entering the fine grinding stage is determined.

[0065] S4: The fine grinding mechanism drives the upper and lower grinding wheels to grind the two end faces of the brake disc to be processed at the initial fine grinding speed and the initial fine grinding feed speed; Specifically, after receiving the fine grinding switching command from the stage control mechanism, the fine grinding mechanism sets the initial fine grinding speed of the upper grinding wheel, the initial fine grinding speed of the lower grinding wheel, and the initial fine grinding feed speed of both the upper and lower grinding wheels. The initial fine grinding speed is lower than the rough grinding speed, and the initial fine grinding feed speed is significantly lower than the rough grinding feed speed. The upper and lower grinding wheels are driven by independent spindle motors, rotating at the set speeds and simultaneously moving towards both ends of the brake disc at the set feed speeds, thus initiating precision grinding. During this process, the sensors integrated into the fine grinding mechanism collect relevant processing parameters in real time and transmit these parameters to the fine grinding analysis mechanism, resonance suppression mechanism, runout compensation mechanism, and processing judgment mechanism.

[0066] S5: The precision grinding analysis mechanism calculates the ratio of the normal grinding force deviation between the upper and lower grinding wheels to the drive shaft torque as the grinding dynamic ratio. Based on the grinding dynamic ratio, it determines whether to adjust the initial speed and feed rate of precision grinding, and adjusts the initial speed and feed rate of precision grinding corresponding to the upper or lower grinding wheel based on the parallelism deviation of the double end faces. Specifically, the precision grinding analysis mechanism receives real-time data from the precision grinding mechanism, including the normal grinding force of the upper grinding wheel, the normal grinding force of the lower grinding wheel, the drive shaft torque, and the axial position data of the upper and lower end faces. It calculates the grinding dynamic ratio and the parallelism deviation value of the two end faces, comparing each with its preset threshold. If the grinding dynamic ratio is greater than the preset value, a unilateral deceleration adjustment is applied to the side with the greater force between the upper and lower grinding wheels. If the parallelism deviation value of the two end faces is greater than the preset value, the initial feed speed of both the upper and lower grinding wheels is simultaneously adjusted in the opposite direction. Finally, the feed speed adjustment and rotational speed adjustment are calculated proportionally and sent to the upper and lower feed servo systems and the spindle drive motor of the precision grinding mechanism.

[0067] Please see Figure 4 As shown, it is a logic decision diagram for adjusting the initial rotation speed and initial feed speed of fine grinding in an embodiment of the present invention.

[0068] In a specific embodiment, to accurately determine whether to adjust the initial grinding speed and feed rate, a preset grinding dynamic ratio E0 corresponding to a grinding dynamic ratio E is set. The preset grinding dynamic ratio E0 is determined based on the double-end-face force balance benchmark of the grinding process under ideal stable conditions under standard operating conditions. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters, and other process conditions remain stable, standard batch processing samples that have been rigorously inspected and confirmed to be free of any process disturbances or equipment malfunctions and whose grinding quality is qualified are collected. During the grinding process, force sensors and torque sensors detect the normal grinding force of the upper grinding wheel, the normal grinding force of the lower grinding wheel, and the drive shaft torque at a fixed sampling frequency, calculate the grinding dynamic ratio, and construct a standard grinding dynamic ratio sample set. The mean and standard deviation of this sample set are calculated as confidence coefficients, and E0 is exemplarily set to 5.0m. −1 The process of comparing E and E0 is as follows: If E is less than or equal to E0, it indicates that the current force balance of the two end faces is good and the deviation of the normal grinding force is within the allowable range. Therefore, it is determined not to adjust the initial speed and feed rate of the fine grinding.

[0069] If E is greater than E0, it indicates that the current double end face is unbalanced and the deviation of the normal grinding force exceeds the allowable range. It is necessary to determine and adjust the initial rotation speed and initial feed speed of fine grinding, so as to evaluate the force balance state of the double end face grinding process in real time based on the grinding dynamic ratio, avoid warping and deformation of thin-walled brake disc due to uneven force, and ensure that the material removal of both end faces is uniform and the parallelism meets the finished product requirements during the fine grinding stage.

[0070] In a specific embodiment, to accurately determine the adjustment process of the initial grinding speed and initial feed rate corresponding to the upper or lower grinding wheel, a preset double-end-face parallelism deviation value F0 is set. The preset double-end-face parallelism deviation value F0 is determined based on the consistency benchmark of the axial positions of the two end faces under ideal stable conditions during the fine grinding process. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters, and other process conditions remain stable, standard batch processing samples that have been rigorously inspected and confirmed to be free from any process disturbances or equipment abnormalities and whose parallelism is qualified after fine grinding are collected. During the fine grinding process, the axial position values ​​of the upper and lower end faces are detected at a fixed sampling frequency using a high-precision displacement sensor, and the parallelism deviation value is calculated to form a standard parallelism deviation sample set. The mean and standard deviation of this sample set are calculated as the basic threshold, and F0 is set to 0.006mm for example. The comparison process based on F and F0 is as follows: If F is less than or equal to F0, it indicates that the current parallelism of the two end faces is qualified and the deviation is within the allowable range. It is determined that the initial feed speed of the upper and lower grinding wheels should not be adjusted at the same time, but unilateral adjustment can still be made according to the grinding dynamic ratio. This can quickly correct the uneven force on one side caused by grinding wheel wear or feed speed mismatch while ensuring that the parallelism of both end faces is qualified, avoid warping and deformation of thin-walled brake discs, and prevent unnecessary double-sided reverse adjustment from disturbing the already qualified parallelism.

[0071] In this embodiment, the following parameters are exemplarily set: axial position value of the upper end face = +0.005mm, axial position value of the lower end face = +0.002mm, normal grinding force of the upper grinding wheel = 320N, normal grinding force of the lower grinding wheel = 280N, drive shaft torque = 8N·m, current initial feed speed of the upper grinding wheel for fine grinding = 60mm / min, initial feed speed of the lower grinding wheel for fine grinding = 60mm / min, initial rotation speed of the upper grinding wheel for fine grinding = 1200rpm, initial rotation speed of the lower grinding wheel for fine grinding = 1200rpm, preset parallelism deviation value of the double end faces F0 = 0.006mm, and preset grinding dynamic ratio E0 = 4.5.

[0072] The parallelism deviation value of the two end faces is F = |0.005-0.002| = 0.003mm. Since the parallelism deviation value of the two end faces F is less than the preset parallelism deviation value of the two end faces F0, it is determined that the initial feed speed of the upper grinding wheel and the lower grinding wheel should not be adjusted at the same time.

[0073] The grinding dynamic ratio E = |320-280| / 8 = 5.0. Since the grinding dynamic ratio E is greater than the preset grinding dynamic ratio E0, and the normal grinding force of the upper grinding wheel is greater than the normal grinding force of the lower grinding wheel, it indicates that the upper grinding wheel is subjected to too much force. Therefore, the initial feed speed of the upper grinding wheel for fine grinding is reduced, while the initial feed speed of the lower grinding wheel for fine grinding remains unchanged.

[0074] The adjustment range is set to be positively correlated with the amount by which the grinding dynamic ratio exceeds the threshold. For example, the adjustment ratio is set to 10 mm / min per unit deviation; the excess amount = E − E0 = 5.0 − 4.5 = 0.5; the total adjustment amount = 10 × 0.5 = 5 mm / min.

[0075] After adjustment, the new feed speed for the upper grinding wheel in fine grinding is 60-5=55mm / min, while the feed speed for the lower grinding wheel in fine grinding remains unchanged at 60mm / min.

[0076] To maintain a constant feed per revolution, and to adjust the upper grinding wheel speed proportionally, the new fine grinding speed of the upper grinding wheel after adjustment is 1200×(55 / 60)=1100rpm, while the fine grinding speed of the lower grinding wheel remains unchanged.

[0077] If F is greater than F0, it indicates that the current parallelism deviation of the two end faces is out of tolerance and exceeds the allowable range. It is determined to adjust the initial feed speed of the upper and lower grinding wheels simultaneously to make the adjustment process more precise and smooth, and avoid damaging the surface quality that has been formed due to large adjustments.

[0078] Specifically, when both the grinding dynamic ratio E and the double-end face parallelism deviation F are greater than the preset double-end face parallelism deviation F0, the bilateral reverse adjustment based on the double-end face parallelism deviation F is prioritized, with the primary goal of correcting the parallelism of both end faces. This is because double-end face parallelism is a core quality indicator in the fine grinding stage, directly affecting the braking performance and assembly accuracy of the finished brake disc; its importance surpasses that of force balance. During the bilateral reverse adjustment, the differentiated adjustment of the feed speeds on both sides can simultaneously correct the parallelism deviation and indirectly improve the force balance, thus eliminating the need for additional unilateral adjustment based on the grinding dynamic ratio E.

[0079] In this embodiment, the axial position value of the upper end face is set to +0.012mm, the axial position value of the lower end face is set to -0.003mm, and the preset parallelism deviation value of the two end faces is F0 = 0.006mm. Then the parallelism deviation value of the two end faces is F = |0.012 - (-0.003)| = 0.015mm. Since the parallelism deviation value of the two end faces is greater than the preset parallelism deviation value of the two end faces F0, the initial feed speed of the fine grinding of the upper grinding wheel and the lower grinding wheel is adjusted simultaneously.

[0080] For example, the initial feed speed of the upper grinding wheel for fine grinding is set to 60 mm / min, and the initial feed speed of the lower grinding wheel for fine grinding is set to 60 mm / min. Since the axial position value of the upper end face is greater than that of the lower end face, it indicates that the upper end face is too high and the lower end face is too low. Therefore, the feed speed of the upper grinding wheel should be reduced, while the feed speed of the lower grinding wheel should be increased to make the two end faces more balanced.

[0081] The adjustment range is set to be positively correlated with the amount by which the parallelism deviation of the two end faces exceeds the threshold. For example, the proportional coefficient is set to 400 mm / (min·mm); the excess amount = F−F0 = 0.015−0.006 = 0.009 mm; the total adjustment amount = 400×0.009 = 3.6 mm / min.

[0082] Since the sum of the changes in the feed rates on both sides is zero, that is, the amount by which the upper grinding wheel decreases is equal to the amount by which the lower grinding wheel increases; therefore, after adjustment, the new feed rate for the upper grinding wheel in fine grinding = 60 − 3.6 = 56.4 mm / min, and the new feed rate for the lower grinding wheel in fine grinding = 60 + 3.6 = 63.6 mm / min.

[0083] To maintain a constant feed per revolution and adjust the rotation speed proportionally, for example, the initial rotation speed of the upper grinding wheel for fine grinding is set to 1200 rpm and the initial rotation speed of the lower grinding wheel for fine grinding is set to 1200 rpm. Then, after adjustment, the new rotation speed of the upper grinding wheel for fine grinding is 1200 × (56.4 / 60) = 1128 rpm and the new rotation speed of the lower grinding wheel for fine grinding is 1200 × (63.6 / 60) = 1272 rpm.

[0084] S6: The resonance suppression mechanism determines the dual-spindle resonance coupling coefficient based on the grinding wheel spindle vibration signals obtained in the rough grinding stage and the fine grinding stage respectively, and determines whether resonance suppression should be performed in the corresponding grinding stage based on the dual-spindle resonance coupling coefficient. Specifically, the resonance suppression mechanism collects the vibration signals of the upper grinding wheel spindle and the lower grinding wheel spindle during the rough grinding and fine grinding stages, respectively, calculates the dual-spindle resonance coupling coefficient, and compares it with the preset dual-spindle resonance coupling coefficient value. If the dual-spindle resonance coupling coefficient is less than or equal to the preset dual-spindle resonance coupling coefficient value, then according to the relationship between the chatter characteristic frequency of each side and the fundamental frequency of the current grinding wheel speed, the grinding wheel speed on that side is adjusted independently and the feed speed on that side is adjusted proportionally, thereby achieving resonance suppression.

[0085] In a specific embodiment, to accurately determine whether resonance suppression is performed in the corresponding grinding stage, a preset dual-spindle resonance coupling coefficient G0 is set, corresponding to a dual-spindle resonance coupling coefficient G. The preset dual-spindle resonance coupling coefficient G0 is determined based on the consistency benchmark of the dual-spindle vibration frequencies under ideal stable conditions during rough or fine grinding processes. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters, and other process conditions remain stable, standard batch processing samples that have been rigorously inspected and confirmed to be free of any process disturbances or equipment abnormalities and have no chatter marks on the processed surface are collected. During the rough or fine grinding stages, vibration signals of the upper and lower grinding wheel spindles are collected at a fixed sampling frequency using an accelerometer, and their respective chatter characteristic frequencies are extracted. The dual-spindle resonance coupling coefficient is calculated to form a standard resonance coupling coefficient sample set. The mean and standard deviation of this sample set are calculated as confidence coefficients, and G0 is set to 2Hz for example. The comparison process between G and G0 is as follows: If G is less than or equal to G0, it indicates that the current dual-spindle chatter characteristic frequencies are relatively close, and there is a risk of coupled resonance. It is determined to perform resonance suppression, so that the suppression mechanism can be triggered in time when the dual-spindle chatter frequencies are close and there is a risk of coupled resonance, so as to avoid serious chatter marks or abnormal wear of the grinding wheel on the machining surface due to the superposition of vibration energy on both sides.

[0086] If G is greater than G0, it indicates that the current dual-spindle chatter characteristic frequency difference is large, the risk of coupled resonance is low, and resonance suppression is not performed.

[0087] In this embodiment, during the rough grinding stage, the initial feed speed of both the upper and lower grinding wheels is 120 mm / min, and the initial rotation speed of both wheels is 2400 rpm. The fundamental frequency is 2400 / 60 = 40 Hz. Through vibration signal spectrum analysis, the characteristic frequency of chattering of the upper grinding wheel is 39 Hz, and the characteristic frequency of chattering of the lower grinding wheel is 41 Hz. The dual-spindle resonance coupling coefficient G = |39−41| = 2 Hz. The preset dual-spindle resonance coupling coefficient G0 = 2 Hz. Since the dual-spindle resonance coupling coefficient G is less than or equal to the preset dual-spindle resonance coupling coefficient G0, resonance suppression is determined.

[0088] The chatter characteristic frequency of the upper grinding wheel is less than the fundamental frequency, so the rotational speed is increased. Assuming the adjustment ratio coefficient is 50 rpm / Hz, the increase in rotational speed is 50 × (40 − 39) = 50 rpm. The new rotational speed of the upper grinding wheel is 2400 + 50 = 2450 rpm. To maintain a constant feed per revolution, the feed rate is increased synchronously: the new feed rate of the upper grinding wheel is 120 × (2450 / 2400) = 122.5 mm / min.

[0089] The characteristic frequency of the lower grinding wheel chatter is greater than the fundamental frequency, so the rotational speed is reduced. Assuming the adjustment ratio coefficient is 50 rpm / Hz, the reduction in rotational speed is 50 × (41 - 40) = 50 rpm. The new rotational speed of the lower grinding wheel is 2400 - 50 = 2350 rpm. To maintain a constant feed per revolution, the feed rate is reduced synchronously: the new feed rate of the lower grinding wheel is 120 × (2350 / 2400) = 117.5 mm / min.

[0090] S7: The runout compensation mechanism determines to perform runout compensation based on the fact that the arithmetic mean deviation of the end face runout is greater than the preset arithmetic mean deviation of the end face runout. Specifically, during the fine grinding stage, the runout compensation mechanism continuously receives end face runout data, calculates the arithmetic mean deviation of the end face runout, and compares it with a preset arithmetic mean deviation value. If the arithmetic mean deviation is greater than the preset value, runout compensation is required. During compensation, the instantaneous end face runout is acquired in real time and compared with the lower and upper limits of a preset instantaneous runout range. If the instantaneous runout is less than the lower limit, the instantaneous feed rate is increased proportionally to the runout offset. If the instantaneous runout is greater than the upper limit, the instantaneous feed rate is decreased proportionally to the runout difference. Finally, the instantaneous feed rate adjustment is calculated proportionally and sent to the upper and lower feed servo systems of the fine grinding mechanism with a millisecond-level response speed, achieving dynamic compensation of the end face runout.

[0091] In a specific embodiment, to accurately determine whether to perform runout compensation, a preset arithmetic mean deviation H0 corresponding to the arithmetic mean deviation H of the end face runout is set. The preset arithmetic mean deviation H0 of the end face runout is determined based on the end face flatness benchmark under ideal and stable conditions of the fine grinding process under standard working conditions. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters and other process conditions remain stable, standard batch processing samples that have been strictly inspected and confirmed to be free from any process disturbances or equipment abnormalities and have qualified end face runout after fine grinding are collected. During the fine grinding process, end face runout data is collected at a fixed sampling frequency using a displacement sensor, and the arithmetic mean deviation is calculated to form a standard arithmetic mean deviation sample set. The mean and standard deviation of this sample set are used as the basic threshold, and H0 is set to 0.005mm for example. The process of comparing H and H0 is as follows: If H is less than or equal to H0, it indicates that the current end face flatness is good and the runout is within the allowable range, so it is determined that runout compensation will not be performed.

[0092] If H is greater than H0, it indicates that the current end face flatness is out of tolerance and the runout exceeds the allowable range. Runout compensation is then performed to identify the end face flatness out of tolerance in real time and trigger the initial feed amount to adjust with the phase in a timely manner, effectively suppressing the impact of brake disc end face runout on grinding accuracy.

[0093] During the fine grinding stage, the runout compensation mechanism receives the instantaneous end face runout transmitted from the fine grinding mechanism in real time.

[0094] In a specific embodiment, to accurately determine the adjustment of the feed rate, a preset instantaneous end-face runout interval [I1, I2] corresponding to an instantaneous end-face runout amount I is set. The preset instantaneous end-face runout interval [I1, I2] is determined based on the instantaneous end-face runout value benchmark of the fine grinding process under ideal stable conditions under standard working conditions. Specifically, under the premise that the initial brake disc material properties, grinding wheel condition, cooling conditions, grinding parameters and other process conditions remain stable, standard batch processing samples that have been strictly inspected and confirmed to be free from any process disturbances or equipment abnormalities and have qualified end-face runout after fine grinding are collected. During the fine grinding process, the instantaneous end-face runout amount at each phase of the brake disc rotation is collected at a fixed sampling frequency using circumferentially arranged displacement sensors, forming a standard instantaneous end-face runout sample set. The mean and standard deviation of this sample set are calculated as the basic threshold, and I1 is set to 0.003mm and I2 to 0.008mm, for example. The process of comparing I with the interval [I1, I2] is as follows: If I is less than I1, it indicates that the end face is deeply concave at the current phase, below the normal range. Therefore, it is determined to increase the initial feed amount to compensate for the concave area of ​​the end face, increase the amount of material removed at this phase, gradually raise the low point to flatness, and effectively reduce the end face runout amplitude.

[0095] In this embodiment, the difference between the lower limit I1 of the preset instantaneous end face runout range and the instantaneous end face runout I is calculated to obtain the runout offset value J. A preset runout offset value J0 is set and compared with the runout offset value J to determine the increase in feed rate.

[0096] The larger the runout offset value J, the smaller the corresponding instantaneous end-face runout I, indicating a deeper end-face depression at the current phase. This necessitates a greater increase in feed rate to avoid insufficient material removal in this area, which could lead to residual local high points or poor end-face flatness. Therefore, the increase in feed rate is positively correlated with the specific runout offset value J.

[0097] In one specific embodiment, to more accurately determine the increase in feed rate, the preset runout offset value J0 is divided into a first preset runout offset value J1 and a second preset runout offset value J2, exemplarily set as J1 = 0.001 mm and J2 = 0.002 mm. The comparison process between J and J1 and J2 is as follows: If J is less than or equal to J1, the feed rate is increased by 5% based on the generated first feed rate increase adjustment command; where the initial feed rate is 60 mm / min, the increased feed rate is 63 mm / min. If J is greater than J1 and less than or equal to J2, the feed rate is increased by 10% based on the generated second feed rate increase adjustment command. If J is greater than J2, the feed rate is increased by 15% based on the generated third feed rate increase adjustment command.

[0098] If I belongs to [I1, I2], it indicates that the end face runout at the current phase is within the allowable range and the flatness is good, so the feed rate should not be changed.

[0099] If I is greater than I2, it indicates that the end face protrusion at the current phase is too high and exceeds the allowable range. Therefore, the initial feed amount should be reduced to suppress the end face protrusion area, reduce the amount of material removed at this phase, and gradually flatten the high point to ensure that the end face flatness meets the requirements.

[0100] In this embodiment, the runout offset value K is obtained by calculating the difference between the instantaneous end face runout I and the lower limit I2 of the preset instantaneous end face runout range. A preset runout difference value K0 is set and compared with the runout difference value K to determine the increase in feed rate.

[0101] The larger the runout difference K, the larger the corresponding instantaneous end-face runout I, indicating that the end-face protrusion is higher at the current phase. This necessitates a greater reduction in the feed rate to avoid excessive material removal in this area, which could lead to localized depressions or poor end-face flatness. Therefore, the reduction in feed rate is positively correlated with the runout difference K.

[0102] In one specific embodiment, to more accurately determine the reduction in feed rate, the preset runout difference K0 is divided into a first preset runout difference K1 and a second preset runout difference K2, exemplarily set to K1 = 0.002 mm and K2 = 0.003 mm. The comparison process between K and K1 and K2 is as follows: If K is less than or equal to K1, the feed rate is reduced by 5% based on the generated first feed rate reduction adjustment command; where the initial feed rate is 60 mm / min, the reduced feed rate is 57 mm / min. If K is greater than K1 and less than or equal to K2, the feed rate is reduced by 10% based on the generated second feed rate reduction adjustment command. If K is greater than K2, the feed rate is reduced by 15% based on the generated third feed rate reduction adjustment command.

[0103] S8: The processing judgment mechanism determines the end time of the fine grinding stage based on the remaining amount of fine grinding and the peak value of the end face runout.

[0104] Specifically, during the fine grinding stage, the processing determination mechanism continuously receives the remaining amount of fine grinding (i.e., the amount of material not yet removed during the fine grinding stage) and the peak value of end face runout from the fine grinding mechanism. The remaining amount of fine grinding is compared with a preset range of remaining amount of fine grinding, and the peak value of end face runout is compared with a preset range of peak value of end face runout to determine the end of the fine grinding stage.

[0105] In a specific embodiment, in order to accurately determine the end time of the fine grinding stage, a preset fine grinding remaining amount interval [L1, L2] corresponding to a fine grinding remaining amount L is set, and a preset end face runout peak value interval [M1, M2] corresponding to an end face runout peak value M is set. The preset fine grinding remaining amount interval [L1, L2] is determined based on the thickness tolerance requirements of the finished brake disc, and is exemplarily set as L1=0.001mm and L2=0.005mm.

[0106] The preset peak-to-peak runout range [M1, M2] is determined based on standards or customer requirements for end-face runout. For example, M1 = 0.001mm and M2 = 0.010mm are set. The process of comparing L with the range [L1, L2] and M with the range [M1, M2] is as follows: If L is greater than L2 or M is greater than M2, it indicates that the current remaining amount of fine grinding is too large or the peak value of end face runout exceeds the standard, and the finished product qualification standard has not been met. The end time of the fine grinding stage is determined not to start, so that fine grinding can continue and runout compensation, resonance suppression and other adjustments are maintained to avoid misjudging the end due to the size or runout not meeting the standard, and to ensure the processing accuracy.

[0107] If L belongs to [L1,L2] and M belongs to [M1,M2], it indicates that the current remaining amount of fine grinding and the peak value of end face runout are both within the preset qualified range. The end time of starting the fine grinding stage is determined, and the end confirmation process is entered. Multiple sampling verifications or delayed stability confirmations are performed. The process only ends after the confirmed parameters are stable and meet the standards, which prevents premature end due to instantaneous fluctuations and improves the reliability of the judgment.

[0108] If L is less than L1 or M is less than M1, it indicates that the current fine grinding remaining amount is below the lower limit, and there is a risk of over-grinding. Alternatively, if the peak value of the end face runout is below the lower limit, it may indicate abnormal signal or over-correction. At this point, the fine grinding stage is terminated, thereby immediately stopping the grinding process to avoid scrapping the workpiece due to over-grinding or excessive runout correction, and to maximize the protection of the product's dimensional and geometric tolerance limits.

[0109] All technologies not mentioned in the above embodiments are existing technologies. It is understood that no specific limitation is made to any preset parameter or critical parameter in the embodiments of the present invention, and the above values ​​are not limited thereto. Those skilled in the art can adjust the preset parameters or critical parameters accordingly based on actual needs, analysis of historical data, or equipment usage.

[0110] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A brake disc double-end face synchronous grinding equipment, characterized in that, include: The rough grinding mechanism is used to drive the upper and lower grinding wheels to grind the two end faces of the brake disc to be processed at the initial rough grinding speed and the initial rough grinding feed speed. The rough grinding analysis mechanism is used to determine whether to adjust the initial speed and feed rate of rough grinding based on the feed deviation, and to adjust the initial speed and feed rate of rough grinding corresponding to the upper or lower grinding wheel based on the imbalance value. The feed deviation is the absolute value of the feed position deviation between the upper and lower grinding wheels. The stage control mechanism is used to determine whether to enter the pre-fine grinding stage based on the amount of coarse grinding residue, and to determine whether to enter the fine grinding stage based on the root mean square value of the acoustic emission signal. The precision grinding mechanism is used to drive the upper and lower grinding wheels to grind the two end faces of the brake disc to be processed at the initial precision grinding speed and the initial precision grinding feed speed. The precision grinding analysis mechanism is used to determine whether to adjust the initial precision grinding speed and initial precision grinding feed rate based on the grinding dynamic ratio, and to adjust the corresponding initial precision grinding speed and initial precision grinding feed rate of the upper or lower grinding wheel based on the parallelism deviation of the double end faces. The grinding dynamic ratio is the ratio of the normal grinding force deviation of the upper and lower grinding wheels to the torque of the drive shaft. The resonance suppression mechanism is used to determine the dual-spindle resonance coupling coefficient based on the grinding wheel spindle vibration signals obtained in the rough grinding stage and the fine grinding stage, and to determine whether resonance suppression should be performed in the corresponding grinding stage based on the dual-spindle resonance coupling coefficient. The processing determination mechanism is used to determine the end time of the finishing stage based on the remaining amount of finishing grinding and the peak value of the end face runout.

2. The brake disc double-end face synchronous grinding equipment according to claim 1, characterized in that, The stage control mechanism is also used to determine whether to enter the pre-fine grinding stage based on the fact that the coarse grinding residue is less than the preset coarse grinding residue. The stage control mechanism also determines to enter the fine grinding stage based on the fact that the root mean square value of the acoustic emission signal is less than the preset root mean square value of the acoustic emission signal.

3. The brake disc double-end face synchronous grinding equipment according to claim 1, characterized in that, The coarse grinding analysis mechanism is also used to determine the adjustment of the initial rotational speed and the initial feed rate of the coarse grinding based on the fact that the feed deviation is greater than the preset feed deviation.

4. The brake disc double-end face synchronous grinding equipment according to claim 3, characterized in that, The rough grinding analysis mechanism is also used to determine, based on the imbalance value being greater than a preset imbalance value, the initial rough grinding feed speeds of the upper and lower grinding wheels are adjusted simultaneously. The imbalance value is the absolute value of the difference between the axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face; Based on the comparison between the axial displacement deviation of the upper end face and the axial displacement deviation of the lower end face, the initial roughing feed speeds of the upper and lower grinding wheels are adjusted in reverse, and the sum of the feed speed adjustments on both sides is zero.

5. The brake disc double-end face synchronous grinding equipment according to claim 1, characterized in that, The fine grinding analysis mechanism is also used to determine the adjustment of the initial fine grinding speed and the initial fine grinding feed speed based on the fact that the grinding dynamic ratio is greater than the preset grinding dynamic ratio.

6. The brake disc double-end face synchronous grinding equipment according to claim 5, characterized in that, The fine grinding analysis mechanism is also used to determine, based on the fact that the parallelism deviation value of the two end faces is greater than a preset parallelism deviation, the initial fine grinding feed speed of the upper and lower grinding wheels is adjusted simultaneously. The parallelism deviation value of the two end faces is the absolute value of the difference between the axial position values ​​of the upper end face and the axial position values ​​of the lower end face. Based on the comparison between the axial position values ​​of the upper end face and the lower end face, the initial feed speeds of the upper and lower grinding wheels are adjusted in reverse, and the sum of the feed speed adjustments on both sides is zero.

7. The brake disc double-end face synchronous grinding equipment according to claim 1, characterized in that, The resonance suppression mechanism is further used to determine resonance suppression based on the fact that the dual-principal-axis resonance coupling coefficient is less than a preset dual-principal-axis resonance coupling coefficient, wherein... Based on the spindle vibration signals of the upper and lower grinding wheels respectively, the corresponding upper end face chatter characteristic frequencies and lower end face chatter characteristic frequencies are determined. The dual-principal-axis resonant coupling coefficient is determined based on the flutter characteristic frequencies of the upper and lower ends. Based on the comparison between the upper end face flutter characteristic frequency and the lower end face flutter characteristic frequency and the corresponding fundamental frequency, the current fine grinding speed and feed rate are adjusted.

8. The brake disc double-end face synchronous grinding equipment according to claim 1, characterized in that, The processing determination mechanism is also used to determine the end time of starting the fine grinding stage based on the fact that the fine grinding remaining amount belongs to a preset fine grinding remaining amount range and the fact that the end face runout peak value belongs to a preset end face runout peak value range. The processing determination mechanism further determines to end the fine grinding stage based on the fact that the remaining fine grinding amount is less than the lower limit of the preset fine grinding remaining amount range, or based on the fact that the peak value of the end face runout is less than the lower limit of the preset end face runout peak value range.

9. The brake disc double-end face synchronous grinding equipment according to claim 1, characterized in that, It also includes a runout compensation mechanism, which determines to perform runout compensation based on the fact that the arithmetic mean deviation of the end face runout is greater than the preset arithmetic mean deviation of the end face runout.

10. The brake disc double-end face synchronous grinding equipment according to claim 9, characterized in that, The runout compensation mechanism is also used to determine the initial feed amount of the upper or lower grinding wheel based on the fact that the instantaneous end face runout is less than the lower limit of the preset instantaneous end face runout range. The increase in the initial feed amount is positively correlated with the runout offset value. The runout compensation mechanism also determines to reduce the initial feed amount of the upper or lower grinding wheel based on the fact that the instantaneous end face runout is greater than the upper limit of the preset instantaneous end face runout range. The reduction in the initial feed amount is positively correlated with the runout difference.

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