Grinding machine and method for dressing a grinding wheel

Abstract

The application relates to the technical field of grinding machines, in particular to a grinding machine and a grinding wheel dressing method, which comprise a grinding machine body and a grinding wheel detection device; the grinding machine body comprises a grinding wheel spindle and a grinding wheel dressing mechanism; the grinding wheel is installed on the grinding wheel spindle and can move along three axes, so that the grinding wheel can be moved to a workpiece for processing or matched to the grinding wheel dressing mechanism for grinding wheel dressing; the grinding wheel detection device comprises a light source mechanism and a detection mechanism; the detection mechanism comprises a projection screen and a profile analysis unit; the profile analysis unit is arranged behind the projection screen; the light source mechanism and the projection screen are arranged on the two sides of the grinding wheel spindle, so that the profile of the grinding wheel is projected on the projection screen when the light source mechanism is irradiated; the profile analysis unit collects the profile projection of the grinding wheel and calculates the profile size of the grinding wheel. The equipment can complete real-time detection of the profile of the grinding wheel in situ, real-time feedback the grinding wheel dressing state, provide data support for dynamic adjustment of the grinding wheel dressing parameters, and improve the grinding wheel dressing precision and the overall machining efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of grinding machines, and more specifically, to a grinding machine and a method for dressing grinding wheels. Background Technology

[0002] Five-axis grinding machines are widely used in the grinding of aerospace turbine blades and precision complex curved surface parts. The profile accuracy and dimensional consistency of the grinding wheel directly determine the final machining accuracy and surface quality of the workpiece. During long-term grinding, grinding wheels will experience problems such as abrasive wear, profile collapse, edge blunting, and outer diameter reduction. Therefore, it is necessary to dress the grinding wheel regularly to restore its theoretical shape and machining performance.

[0003] Currently, the industry mainly uses methods such as forming roller extrusion dressing, fixed diamond roller dressing, and CBN wheel shaping dressing for grinding wheel dressing. Among them, traditional forming rollers, diamond rollers, and CBN shaped grinding wheels are all dedicated shaping structures. For products with different profiles and angles, it is necessary to customize special rollers or shaped grinding wheels separately. This has the problems of high customization costs, long production cycles, and poor versatility. It is especially unsuitable for the processing of blade-type parts with multiple varieties, small batches, and frequent profile iterations.

[0004] In existing technologies, grinding wheel dressing generally adopts an "offline inspection, open-loop dressing" mode, which lacks real-time, in-situ dimensional and contour feedback during the dressing process. The conventional dressing process is as follows: the grinding wheel is dressed by setting fixed feed parameters based on experience, and then the grinding wheel is disassembled or the machine is stopped for sampling inspection using manual measuring tools and coordinate measuring machines. This process suffers from problems such as detection lag and inability to dynamically adjust dressing parameters. If the initial dressing results in under-dressing or contour deviation, repeated machine stops for re-measurement and secondary dressing are required, severely impacting processing efficiency. If the dressing parameters are too large, it can easily cause over-cutting and scrapping of the grinding wheel, resulting in high consumable costs.

[0005] In summary, existing grinding wheel dressing technologies suffer from numerous drawbacks, including poor tooling versatility, lack of closed-loop feedback during dressing, mismatch between coarse and fine dressing processes, low online detection accuracy, weak anti-interference capability, excessive manual intervention, and poor dressing consistency. These shortcomings make it difficult to meet the production needs of five-axis grinding machines for high-precision, high-efficiency, flexible, and low-cost grinding wheel dressing. Summary of the Invention

[0006] The purpose of this invention is to provide a grinding machine and a grinding wheel dressing method, which can conveniently monitor the external dimensions of the grinding wheel and facilitate grinding wheel dressing.

[0007] The embodiments of the present invention are achieved through the following technical solutions: A grinding machine includes a grinding machine body and a grinding wheel detection device. The grinding machine body includes a grinding wheel spindle and a grinding wheel dressing mechanism. The grinding wheel is mounted on the grinding wheel spindle and is movable along three axes, so that the grinding wheel can be moved to a workpiece for machining or cooperate with the grinding wheel dressing mechanism for grinding wheel dressing. The grinding wheel detection device includes a light source mechanism and a detection mechanism. The detection mechanism includes a projection screen and a contour analysis unit. The contour analysis unit is located behind the projection screen. The light source mechanism and the projection screen are located on both sides of the grinding wheel spindle, so that the outer contour of the grinding wheel is projected onto the projection screen when illuminated by the light source mechanism. The contour analysis unit acquires the contour projection of the grinding wheel and calculates the contour dimensions of the grinding wheel.

[0008] Furthermore, the grinding wheel spindle is provided with a protective cover; the grinding wheel is located inside the protective cover; an opening is provided at the bottom of the protective cover so that the lower part of the grinding wheel is located outside the protective cover; the light source mechanism and the detection mechanism are respectively provided on both sides of the protective cover.

[0009] Furthermore, both sides of the protective cover are provided with through holes; each through hole is provided with a protective cover; the protective cover is hinged to the protective cover; the protective cover is also provided with a torsion spring so that the protective cover can fit against the protective cover and close the through holes of the protective cover; both the light source mechanism and the detection mechanism are provided with a pushing mechanism so that the light source mechanism and the detection mechanism can extend into the interior of the protective cover or retract to the exterior of the protective cover through the through holes.

[0010] Furthermore, the rotating shaft of the trimming mechanism is equipped with a trimming wheel and two disc wheels.

[0011] A grinding wheel dressing method includes the following steps: S1, Station Switching: Controls the grinding wheel spindle of the five-axis grinding machine to move the grinding wheel to be dressed to the dressing mechanism built into the grinding machine. S2. Rough dressing of grinding wheel: Align the grinding wheel to be dressed with the dressing wheel, and use the dressing wheel to quickly rough grind the excess material on the outer diameter of the grinding wheel to remove the excess material that is larger than the preset reference size, until the outer diameter of the grinding wheel is dressed to the preset reference size; the preset reference size is 155mm. S3, Grinding wheel fine dressing station switching: After rough dressing is completed, the grinding wheel spindle drives the grinding wheel to disengage from the dressing wheel and move to the disc wheel fine dressing station corresponding to the working condition; S4. Precision dressing of disc wheel: By adjusting the relative depth of cut and feed rate between the grinding wheel and the disc wheel, the profile and dimensions of the grinding wheel are precisely dressed using a cutting dressing method. S5. Online cleaning of grinding wheel: After a single precision dressing is completed, control the grinding wheel to detach from the disc wheel, keep the grinding wheel rotating at high speed, turn on the machine tool coolant to continuously flush the entire grinding wheel, and remove the grinding debris and dust attached to the surface of the grinding wheel; after flushing, turn off the coolant, and the grinding wheel continues to rotate at high speed to use centrifugal force to remove the residual coolant on the surface. S6. Tangent Projection Contour Online Inspection: After the cleaning process is completed, the control light source mechanism and the inspection mechanism are moved to the inspection station; the light source is adjusted to emit a parallel beam along the tangent direction of the outer edge of the grinding wheel, so that the edge of the grinding wheel blocks the light and forms a clear silhouette contour on the projection screen; the silhouette image is acquired by the contour analysis unit arranged on the back of the projection screen, and the edge contour of the grinding wheel is extracted by the image analysis software. It is compared with the theoretical standard contour and standard size parameters of the grinding wheel to calculate the shape, contour and size deviation values ​​of the grinding wheel. S7. Closed-loop dressing control: Dynamically adjust the dressing parameters of the disc wheel dressing depth and feed rate based on the detected deviation value, repeat steps S4-S6, and perform iterative precision dressing and online detection of the grinding wheel until the grinding wheel profile accuracy and external dimensions meet the process qualification standards. S8. Reset and Finishing: After the grinding wheel is dressed to the required standard, the control light source mechanism and the detection mechanism are removed from the detection station, and the grinding wheel spindle drives the dressed grinding wheel back to the grinding station to complete the overall grinding wheel dressing process.

[0012] Furthermore, in step S6, in the non-detection state, the light source mechanism and the detection mechanism are completely removed from the grinding wheel dressing area to avoid interfering with the rough dressing, fine dressing and machine tool processing actions of the grinding wheel; in the detection state, the light source mechanism and the detection mechanism are synchronously aligned and arranged on both sides of the grinding wheel to ensure that the parallel beam is strictly incident along the tangential direction of the grinding wheel.

[0013] Furthermore, in step S5, the grinding wheel is kept rotating at high speed throughout the washing and water-spraying process, and the dressing, cleaning, and testing processes are equipped with PLC electrical interlocks. The testing mechanism can only start the moving alignment action when the coolant is turned off, the water-spraying time of the grinding wheel reaches the preset threshold, and the grinding wheel is completely separated from the dressing wheel.

[0014] Furthermore, in step S6, a global shutter industrial camera is used to acquire a silhouette image of the projection screen. By shortening the exposure time, motion blur caused by the high-speed rotation of the grinding wheel is suppressed. At the same time, an image sub-pixel edge extraction algorithm is configured to accurately identify the actual contour edge of the grinding wheel.

[0015] Furthermore, in step S2, a dimensional pre-inspection mechanism is set up for the rough finishing process. After the rough finishing is completed, the outer diameter of the grinding wheel can be checked by the projection inspection mechanism to see if it reaches the reference size of 155mm. Only after confirming that it meets the standard can the process be switched to the disc wheel fine finishing station.

[0016] Furthermore, the coolant nozzle is also connected to a high-pressure air source; in S5, after the grinding wheel removes the residual coolant from its surface, the coolant nozzle cuts off the coolant and sprays high-pressure air to clean the surface of the grinding wheel, removing water mist and dust, and ensuring the clarity of the silhouette image and the accuracy of the detection.

[0017] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects: This invention, based on a conventional five-axis grinding machine, adds an online silhouette detection device for the grinding wheel, consisting of a light source mechanism, a projection screen, and a back-side contour analysis unit. The light source and projection screen are positioned on opposite sides of the grinding wheel spindle, respectively. Tangential parallel light is projected to form the silhouette of the grinding wheel contour, and the wheel contour dimensions are obtained in real time through image acquisition and contour calculation. Relying on this integrated structure, the equipment can perform real-time detection of the grinding wheel contour in situ, replacing the traditional open-loop mode of offline sampling and manual measurement. This eliminates detection lag and provides real-time feedback on the grinding wheel dressing status, offering reliable data support for dynamic adjustment of grinding wheel dressing parameters and closed-loop precision dressing, effectively improving grinding wheel dressing accuracy and overall processing efficiency.

[0018] This invention utilizes a grinding wheel protective cover with a bottom opening on a five-axis grinding machine, and arranges the detection component on the upper part of the protective cover corresponding to the non-working area of ​​the grinding wheel. This forms a partitioned operation structure with online detection at the top and grinding and dressing at the bottom. Without interfering with the normal working conditions of workpiece grinding and grinding wheel dressing, it effectively isolates the detection area from interference by machine tool coolant and grinding dust, significantly improving the stability and imaging clarity of contour detection under complex working conditions. By setting through holes with torsion spring return protective covers on both sides of the protective cover, and using an electric push rod type jacking mechanism to drive the detection component to extend and retract, adaptive switching between the working extension and standby retraction of the detection component is achieved. Under normal conditions, the protective through holes can be closed to protect the detection device. During operation, precise alignment is achieved for detection, avoiding the problems of easy damage and interference with equipment operation of fixed detection structures, while ensuring the alignment accuracy and repeatability of each detection.

[0019] This invention integrates a roughing and finishing dressing module with a roughing dressing wheel and a dual-differentiated precision disc wheel in the dressing mechanism. First, the dressing wheel quickly removes the excess outer diameter of the oversized grinding wheel, uniformly adjusting the grinding wheel to the reference size. Then, the programmable disc wheel completes the precision contour dressing in a cutting-type forming method. This invention abandons the structural limitations of traditional one-to-one dedicated forming rollers and diamond rollers. Relying on a programmable and flexible dressing mode, it adapts to the processing scenarios of multiple varieties, small batches, and frequent profile iterations of blades, significantly reducing the cost and cycle of custom-made special tooling. At the same time, it enables the recycling and reuse of waste grinding wheels, reducing material consumption.

[0020] This invention features a fully automated closed-loop dressing process. After each wheel dressing operation, it sequentially performs coolant rinsing, high-speed centrifugal water removal, and high-pressure air blowing to thoroughly remove adhering substances and water mist from the grinding wheel surface, ensuring high-quality silhouette imaging. The grinding wheel contour is precisely extracted using tangential projection imaging combined with sub-pixel edge recognition technology. Based on measured dimensional deviations, the wheel feed depth and feed rate are dynamically fine-tuned, iteratively completing adaptive dressing and precision calibration. Simultaneously, the equipment incorporates a full-process PLC electrical interlock and rough dressing pre-inspection mechanism to standardize process sequences, prevent equipment interference, avoid under-dressing rework and over-cutting scrap, and eliminate the need for manual intervention for retesting and parameter adjustment. This significantly improves the automation level, dimensional consistency, and finished product qualification rate of grinding wheel dressing, adapting to the flexible production needs of five-axis grinding machines requiring high precision, high efficiency, and low cost. Attached Figure Description

[0021] Figure 1 This is a perspective view of the machine tool of the present invention.

[0022] Figure 2 This is a perspective view of the machine tool of the present invention from another angle.

[0023] Figure 3 Front view of the machine tool.

[0024] Figure 4 A schematic diagram showing the light source mechanism and the detection mechanism housed within the protective cover.

[0025] Figure 5 for Figure 4 Enlarged view of point a in the middle.

[0026] Figure 6 This is a schematic diagram showing the light source mechanism and the detection mechanism extending into the protective cover.

[0027] Figure 7 This is a schematic diagram of a disc wheel cutting a workpiece.

[0028] Reference numerals: 1-Grinding wheel spindle, 2-Grinding wheel dressing mechanism, 3-Grinding wheel, 4-Light source mechanism, 5-Detection mechanism, 6-Projection screen, 7-Light source, 8-Industrial camera, 9-Protective cover, 10-Protective cap, 11-Pushing mechanism, 12-Disc wheel, 13-Dressing wheel, 14-Stage, 15-Coolant nozzle, 16-Workpiece. Detailed Implementation

[0029] like Figures 1-7As shown, this embodiment discloses a five-axis grinding machine with an online profile detection function and a precision dressing method for a grinding wheel 3, which aims to solve the technical defects of the existing five-axis grinding machine grinding wheel 3 dressing process that it relies on special shaping rollers, has poor tooling universality, the dressing process is an open-loop unfeedback mode, detection lags, requires much manual intervention, and it is difficult to guarantee dressing accuracy and consistency. The present invention can adapt to the grinding processing scenarios of precision parts such as aero-engine turbine blades which are characterized by multiple varieties, small batches and frequent profile iteration, greatly reduce the dressing cost of the grinding wheel 3, and improve the automation degree of dressing and forming accuracy. The main body of the grinding machine follows the basic architecture of the existing five-axis grinding machine, and the core innovation lies in the integration of an adaptive position-avoiding tangential projection detection device for the grinding wheel 3, which optimizes the traditional grinding wheel 3 dressing system from both the dimensions of hardware structure and processing technology.

[0030] The overall grinding machine includes a grinding machine body and a grinding wheel 3 detection device. The core of the grinding machine body comprises a grinding wheel spindle 1 and a grinding wheel dressing mechanism 2. The grinding wheel 3 is detachably and fixedly mounted on the grinding wheel spindle 1, and the grinding wheel spindle 1 has a three-axis movement capability, which can drive the grinding wheel 3 to switch stations flexibly. It can not only move to the processing area of the workpiece 16 to complete the part grinding operation, but also achieve precise positioning and cooperate with the grinding wheel dressing mechanism 2 to realize the in-situ dressing operation of the worn grinding wheel 3, without disassembling the grinding wheel 3 for off-line processing, which avoids the problems of cumbersome disassembly and assembly and large positioning accuracy deviation in traditional off-line dressing. The grinding machine body also includes a stage 14 capable of rotating in two directions, which is used for placing the workpiece 16 and adjusting the angle of the workpiece 16 to meet the processing requirements.

[0031] The grinding wheel 3 detection device equipped with the grinding machine integrates an independent light source mechanism 4 and a detection mechanism 5. The detection mechanism 5 is composed of a projection screen 6 and a profile analysis unit, and the profile analysis unit is correspondingly arranged at the back side of the projection screen 6 to form a back-shot imaging detection structure. The light source mechanism 4 and the projection screen 6 are symmetrically arranged on both sides of the grinding wheel spindle 1. After the stations are aligned, the light beam output by the light source mechanism 4 can be irradiated along the tangential direction of the outer edge of the grinding wheel 3. The solid grinding wheel 3 blocks the light beam to form a complete and undistorted silhouette profile of the outer edge of the grinding wheel 3 on the projection screen 6. The profile analysis unit collects the profile image on the projection screen 6 in real time, completes profile edge extraction, size fitting and deviation calculation through built-in control software, and obtains the actual profile size data of the grinding wheel 3 in real time. This structure adopts the industrially mature silhouette measurement principle, which is different from the traditional manual measuring tool detection and coordinate measuring machine off-line sampling inspection methods, and can realize in-situ real-time detection of the grinding wheel 3 dressing process, completely solving the defects of detection lag and inability to dynamically adjust process parameters in the traditional open-loop dressing mode, and providing accurate data support for real-time closed-loop regulation of grinding wheel 3 dressing. Meanwhile, the light source mechanism 4 has a built-in optical lens structure, which can convert the point light source 7 into a uniform parallel light beam, effectively avoiding the problems of profile ghosting and edge blurring caused by scattered light, and ensuring the accuracy and stability of profile detection from the perspective of optical structure.

[0032] The grinding wheel spindle 1 is externally fitted with a protective cover 9, and the grinding wheel 3 is completely housed inside the protective cover 9. The bottom of the protective cover 9 has an open structure, allowing the lower part of the grinding wheel 3 to be exposed, while the upper part is within the protection range of the protective cover 9. Grinding and dressing operations of the grinding wheel 3 are both completed through the exposed lower part of the grinding wheel 3, which can normally meet the requirements of grinding the workpiece 16 and dressing it in contact with the dressing wheel 13. The protective cover 9 can completely shield the coolant, grinding debris, and dust splashed during the high-speed rotation of the grinding wheel 3, preventing contaminants from spreading into the machine tool. This solves the problems of traditional detection devices being easily affected by the working environment and having poor detection stability. The light source mechanism 4 and the detection mechanism 5 are symmetrically arranged on the left and right sides of the upper part of the protective cover 9, so that the two sets of detection components correspond to the non-working area on the upper part of the grinding wheel 3, realizing the zoned collaborative working mode of detection on the upper part of the grinding wheel 3 and operation on the lower part. The operation and detection stations do not interfere with each other. Under the premise of not affecting normal grinding and dressing operations, the normal online detection of the profile of the grinding wheel 3 is realized, effectively improving the integration of equipment and the continuity of operation.

[0033] Both sides of the protective cover 9 have through holes connecting the inside and outside corresponding to the installation positions of the light source mechanism 4 and the detection mechanism 5. Each through hole is hinged with a protective cover 10. A torsion spring elastic reset structure is installed between the protective cover 10 and the protective cover 9. Under normal conditions, the torsion spring drives the protective cover 10 to fit tightly against the end face of the through hole, realizing the complete sealing of the through hole and isolating the coolant water mist, metal scraps and abrasive dust inside the protective cover 9. This provides all-weather protection for the external light source mechanism 4 and detection mechanism 5, avoiding problems such as blurred imaging, structural damage and drift in detection accuracy caused by long-term contamination of components under working conditions. Both the light source mechanism 4 and the detection mechanism 5 are equipped with a push mechanism 11 on their outer sides. The push mechanism 11 can be an electric push rod, capable of outputting linear telescopic power to drive the light source mechanism 4 and the detection mechanism 5 through the through hole of the protective cover 9 into the internal detection station to complete the detection operation. During the process, the protective cover 10 is pushed open. After the detection is completed, the push mechanism 11 retracts in the opposite direction, driving both sets of components to completely retract outside the protective cover 9. At the same time, the push limit on the protective cover 10 is released, and the protective cover 10 automatically resets and closes the through hole under the action of the torsion spring. This telescopic avoidance structure realizes the adaptive switching of the detection components extending during operation and retracting during standby. It not only ensures the alignment accuracy during detection, but also completely solves the problem that the traditional fixed detection mechanism 5 is easily damaged by working conditions and interferes with the machine tool operation, greatly improving the service life and operational stability of the device.

[0034] The rotating shaft of the grinding wheel dressing mechanism 2 is integrated with a set of coarse dressing wheels 13 and two precision disc wheels 12 with different functions, forming an integrated coarse and fine dressing module. This is different from the layout defects of traditional grinding wheel dressing equipment with a single dressing structure and a single dressing mode. Among them, the dressing wheel 13 is mainly responsible for the coarse dressing of waste grinding wheels 3 and grinding wheels with large allowance wear 3. For large-sized grinding wheels 3 with an outer diameter of over 155mm, it can quickly remove the excess material on the outer circle of the grinding wheel 3, efficiently complete the dimensional correction, and significantly reduce the cutting load of the precision disc wheels 12. This avoids the problems of long dressing time, rapid wear of disc wheels 12, and low processing efficiency that occur when directly using disc wheels 12 to fine dress grinding wheels with large allowance wear 3. The two disc wheels 12 feature a universal flexible dressing structure, abandoning the traditional one-to-one dedicated structure of forming rollers, diamond rollers, and CBN grinding wheels 3. This eliminates the need for custom-designed tooling for grinding wheels 3 with different profiles and angles; simply adjusting the feed path and dressing parameters via CNC programming allows for precision forming and dressing of grinding wheels 3 with different contours and working conditions. For example... Figure 7 As shown, its dressing principle is similar to the cutting process of a machining center, which achieves the dressing of the shape of the grinding wheel 3 by cutting away the excess part. Figure 7 The shaded area represents the material to be removed. This design perfectly adapts to the multi-variety, small-batch, and frequently iterative blade processing scenarios, effectively solving the industry pain points of high cost, long production cycle, and poor versatility associated with traditional custom tooling. It significantly improves the flexibility and economy of grinding wheel dressing. Simultaneously, this structure enables the recycling and reuse of discarded grinding wheels. By roughly adjusting the dimensions and finely restoring the original contour, the processing performance of the discarded grinding wheel is restored, reducing the cost of replacing grinding wheel consumables.

[0035] The grinding wheel 3 dressing method disclosed in this embodiment achieves fully automated closed-loop dressing based on the aforementioned integrated grinding machine structure. The overall process is tightly connected and highly automated, requiring no manual intervention for retesting and parameter adjustment, effectively overcoming the shortcomings of traditional dressing processes, such as high reliance on manual labor and poor dressing consistency. In actual operation, the workstation is first switched by the three-axis movement of the grinding wheel spindle 1, which precisely moves the grinding wheel 3 to be dressed to the dressing mechanism station built into the grinding machine, completing the initial alignment preparation for the dressing operation. Then, the rough dressing process begins, where the out-of-tolerance grinding wheel 3 is precisely aligned with the dressing wheel 13. Utilizing the high-efficiency grinding characteristics of the dressing wheel 13, excess material on the outer diameter of the grinding wheel 3 is quickly removed, continuously reducing the outer diameter of the grinding wheel 3 until it is adjusted to the reference size of 155mm, completing the large-mass rough machining and laying the foundation for subsequent precision forming dressing. Through the rough and fine process separation mode, both the efficiency of large-mass dressing and the precision of precision dressing are taken into account.

[0036] After the rough dressing dimensions of grinding wheel 3 are met, the grinding wheel spindle 1 drives grinding wheel 3 to smoothly disengage from the rough dressing wheel 13. Based on the contour type and machining conditions of the grinding wheel 3 to be dressed, it is precisely moved to the corresponding precision dressing station of disc wheel 12, completing the fine dressing station switch. Subsequently, the relative depth of cut and feed rate of grinding wheel 3 and disc wheel 12 are precisely controlled by the CNC system. A precision cutting dressing mode is used to finely dress the wheel surface contour, edge shape, and overall dimensions of grinding wheel 3. Relying on the programmable flexible dressing characteristics of disc wheel 12, the theoretical forming contour of grinding wheel 3 is accurately restored, replacing the dressing method of traditional dedicated shaping rollers and greatly improving the dressing versatility.

[0037] After a single precision dressing of disc wheel 12 is completed, the system automatically enters the online cleaning process. Grinding wheel 3, maintaining high-speed rotation, detaches from the dressing area of ​​disc wheel 12. The machine tool activates coolant to continuously flush the entire surface of grinding wheel 3, thoroughly removing the grinding debris, detached abrasive grains, and impurities adhering during the dressing process. This prevents surface deposits from obscuring the contours of grinding wheel 3 and affecting subsequent inspection accuracy. After the coolant flushing is complete, the coolant circuit is shut off. Grinding wheel 3 continues to rotate at high speed, relying on centrifugal force to remove residual coolant droplets from the surface, thus initially completing the drying and cleaning of the grinding wheel 3 surface and minimizing imaging interference caused by water mist and droplets. The entire cleaning process is fully automated, requiring no manual wiping or cleaning, and is suitable for continuous machine tool operation.

[0038] After the cleaning process meets the standards, the equipment's push mechanism 11 moves synchronously, driving the light source mechanism 4 and the detection mechanism 5 to extend and precisely align, ensuring that the parallel light beam is incident strictly along the tangent direction of the outer edge of the grinding wheel 3. The grinding wheel 3, by physically blocking the light beam, forms a clear, distortion-free silhouette outline on the projection screen 6. The contour analysis unit acquires the projected image through a high-frame-rate global shutter industrial camera 8, and, in conjunction with a sub-pixel edge extraction algorithm, accurately captures the true contour edge of the grinding wheel 3, effectively suppressing motion blur caused by the high-speed rotation of the grinding wheel 3 and improving contour recognition accuracy. The system automatically compares the measured contour dimensions with preset theoretical standard contour parameters, accurately calculating the contour deviation and dimensional deviation data of the grinding wheel 3, providing precise data support for process parameter adjustment, and completely solving the drawbacks of traditional open-loop dressing that lacks real-time data feedback and relies solely on experience for parameter adjustment.

[0039] The system implements closed-loop adaptive control based on the detected deviation data. For cases where grinding wheel 3 is under-dressed or its contour deviation exceeds the standard, it automatically fine-tunes the depth of cut and feed parameters of disc wheel 12 for minor repair. For conditions where the dimensions are close to the acceptable threshold, it automatically reduces the dressing feed speed to achieve flexible precision dressing, effectively avoiding the problems of under-dressing rework and over-cutting that are common in traditional dressing processes. The equipment iteratively executes precision dressing, online cleaning, and contour detection processes, continuously correcting the contour dimensions of grinding wheel 3 until its contour accuracy and external dimensions fully meet the process standards. This closed-loop iterative mode significantly improves the consistency and pass rate of grinding wheel 3 dressing.

[0040] In the overall operation process, the equipment uses a PLC program to set electrical interlock logic for all processes, strictly limiting the execution sequence of each process. Only when the coolant is completely shut off, the water-spraying time of the grinding wheel 3 reaches the preset standard, and the grinding wheel 3 is completely detached from the dressing wheel 13 structure, will the extension and alignment action of the detection mechanism 5 be triggered. This effectively avoids equipment failures such as mechanism interference and collisions, ensuring the safety and stability of the process operation. At the same time, a pre-inspection mechanism is added to the rough dressing process. After the rough dressing of the grinding wheel 3 is completed, the outer diameter dimension can be verified by the online projection detection mechanism 5. Only after confirming that the accurate 155mm reference dimension is reached can it enter the fine dressing process. This avoids problems such as disc wheel 12 wear and dressing accuracy deviation caused by the dimensional non-compliance entering the fine dressing station from the source.

[0041] To further optimize cleaning performance and ensure imaging accuracy, the coolant nozzle 15 integrates a high-pressure air supply path. After the grinding wheel 3 has finished centrifugally ejecting water, the coolant supply can be cut off and the high-pressure air jet mode can be switched to perform all-round air blowing cleaning of the outer edge of the grinding wheel 3 and the detection area, thoroughly removing residual water mist, fine dust, and adhering substances. This solves the problem of interference in detection imaging under complex machine tool conditions, and continuously ensures the clarity of the silhouette outline and the accuracy of the detection data. After the grinding wheel 3 has been fully dressed, the push mechanism 11 drives the light source mechanism 4 and the detection mechanism 5 to retract outside the protective cover 9. The protective cover 10 automatically resets and closes the through hole. The grinding wheel spindle 1 drives the dressed grinding wheel 3 back to the workpiece 16 machining station, completing the entire grinding wheel 3 dressing process. This achieves a fully automated closed-loop operation of grinding wheel 3 dressing, detection, parameter adjustment, and reset, effectively adapting to the high-precision, high-efficiency, flexible, and low-cost production needs of five-axis grinding machines.

Claims

1. A grinding machine, characterized in that: The system includes a grinding machine body and a grinding wheel detection device. The grinding machine body includes a grinding wheel spindle and a grinding wheel dressing mechanism. The grinding wheel is mounted on the grinding wheel spindle and can move along three axes to move it to the workpiece or to cooperate with the grinding wheel dressing mechanism for grinding wheel dressing. The grinding wheel detection device includes a light source mechanism and a detection mechanism. The detection mechanism includes a projection screen and a contour analysis unit. The contour analysis unit is located behind the projection screen. The light source mechanism and the projection screen are located on both sides of the grinding wheel spindle so that the outer contour of the grinding wheel is projected onto the projection screen when illuminated by the light source mechanism. The contour analysis unit collects the contour projection of the grinding wheel and calculates the contour dimensions of the grinding wheel.

2. The grinding machine according to claim 1, characterized in that: The grinding wheel spindle is equipped with a protective cover; the grinding wheel is located inside the protective cover; an opening is provided at the bottom of the protective cover so that the lower part of the grinding wheel is located outside the protective cover; the light source mechanism and the detection mechanism are respectively provided on both sides of the protective cover.

3. The grinding machine according to claim 2, characterized in that: Both sides of the protective cover are provided with through holes; each through hole is provided with a protective cover; the protective cover is hinged to the protective cover; the protective cover is also provided with a torsion spring so that the protective cover can fit against the protective cover and close the through holes of the protective cover; both the light source mechanism and the detection mechanism are provided with a pushing mechanism so that the light source mechanism and the detection mechanism can extend into the interior of the protective cover or retract to the exterior of the protective cover through the through holes.

4. The grinding machine according to claim 3, characterized in that: The dressing mechanism has a dressing wheel and two disc wheels on its rotating shaft.

5. A method for dressing a grinding wheel, characterized in that, Includes the following steps: S1, Station Switching: Controls the grinding wheel spindle of the five-axis grinding machine to move the grinding wheel to be dressed to the dressing mechanism built into the grinding machine. S2. Rough dressing of grinding wheel: Align the grinding wheel to be dressed with the dressing wheel, and use the dressing wheel to quickly rough grind the excess material on the outer diameter of the grinding wheel to remove the excess material that is larger than the preset reference size, until the outer diameter of the grinding wheel is dressed to the preset reference size; the preset reference size is 155mm. S3, Grinding wheel fine dressing station switching: After rough dressing is completed, the grinding wheel spindle drives the grinding wheel to disengage from the dressing wheel and move to the disc wheel fine dressing station corresponding to the working condition; S4. Precision dressing of disc wheel: By adjusting the relative depth of cut and feed rate between the grinding wheel and the disc wheel, the profile and dimensions of the grinding wheel are precisely dressed using a cutting dressing method. S5. Online cleaning of grinding wheel: After a single precision dressing is completed, control the grinding wheel to detach from the disc wheel, keep the grinding wheel rotating at high speed, turn on the machine tool coolant to continuously flush the entire grinding wheel, and remove the grinding debris and dust attached to the surface of the grinding wheel; after flushing, turn off the coolant, and the grinding wheel continues to rotate at high speed to use centrifugal force to remove the residual coolant on the surface. S6. Tangent Projection Contour Online Inspection: After the cleaning process is completed, the control light source mechanism and the inspection mechanism are moved to the inspection station; the light source is adjusted to emit a parallel beam along the tangent direction of the outer edge of the grinding wheel, so that the edge of the grinding wheel blocks the light and forms a clear silhouette contour on the projection screen; the silhouette image is acquired by the contour analysis unit arranged on the back of the projection screen, and the edge contour of the grinding wheel is extracted by the image analysis software. It is compared with the theoretical standard contour and standard size parameters of the grinding wheel to calculate the shape, contour and size deviation values ​​of the grinding wheel. S7. Closed-loop dressing control: Dynamically adjust the dressing parameters of the disc wheel dressing depth and feed rate based on the detected deviation value, repeat steps S4-S6, and perform iterative precision dressing and online detection of the grinding wheel until the grinding wheel profile accuracy and external dimensions meet the process qualification standards. S8. Reset and Finishing: After the grinding wheel is dressed to the required standard, the control light source mechanism and the detection mechanism are removed from the detection station, and the grinding wheel spindle drives the dressed grinding wheel back to the grinding station to complete the overall grinding wheel dressing process.

6. The grinding wheel dressing method according to claim 5, characterized in that: In step S6, in the non-detection state, the light source mechanism and the detection mechanism are completely removed from the grinding wheel dressing area to avoid interfering with the rough dressing, fine dressing and machine tool processing actions of the grinding wheel; in the detection state, the light source mechanism and the detection mechanism are synchronously aligned and arranged on both sides of the grinding wheel to ensure that the parallel beam is strictly incident along the tangential direction of the grinding wheel.

7. The grinding wheel dressing method according to claim 5, characterized in that: In step S5, the grinding wheel is kept rotating at high speed throughout the washing and water-spraying process. The dressing, cleaning and testing processes are equipped with PLC electrical interlocks. The testing mechanism can only start the moving alignment action when the coolant is turned off, the water-spraying time of the grinding wheel reaches the preset threshold, and the grinding wheel is completely separated from the dressing wheel.

8. The grinding wheel dressing method according to claim 5, characterized in that: In step S6, a global shutter industrial camera is used to capture the silhouette image of the projection screen. By shortening the exposure time, motion blur caused by the high-speed rotation of the grinding wheel is suppressed. At the same time, an image sub-pixel edge extraction algorithm is configured to accurately identify the actual contour edge of the grinding wheel.

9. The grinding wheel dressing method according to claim 5, characterized in that: Step S2, the rough finishing process, sets up a dimensional pre-inspection mechanism. After the rough finishing is completed, the outer diameter of the grinding wheel can be checked by the projection inspection mechanism to see if it reaches the 155mm reference size. Only after confirming that it meets the standard can it be switched to the disc wheel fine finishing station.

10. The grinding wheel dressing method according to claim 5, characterized in that: The coolant nozzle is also connected to a high-pressure air source; in S5, after the grinding wheel removes the residual coolant from its surface, the coolant nozzle cuts off the coolant and sprays high-pressure air to clean the surface of the grinding wheel, removing water mist and dust, and ensuring the clarity of the silhouette image and the accuracy of the detection.

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