Online laser cleaning equipment for mold

Abstract

The invention discloses mold online laser cleaning equipment and relates to the field of laser cleaning, a laser cleaning head, a mechanical arm and a visual system of the equipment are all connected with a master control system, an image acquisition device is connected with the visual system, the laser cleaning head is arranged at the tail end of the mechanical arm, and the image acquisition device is arranged on the side face of the laser cleaning head; the image acquisition device is used for acquiring an image of a positioning object arranged on the mold machine table and sending the image of the positioning object to the visual system, and the visual system is used for processing the image of the positioning object by adopting a visual positioning algorithm to obtain offset and sending the offset to the master control system; and the master control system is used for controlling the motion trail of the mechanical arm according to the offset and the preset trail so as to clean the mold arranged on the mold machine table. According to the mold cleaning device, the mold can be cleaned under the condition that the mold is not disassembled, so that the working hours consumed for disassembling the mold are saved, the production efficiency is improved, the manufacturing cost is saved, and equipment transformation is not needed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser cleaning, in particular to an online laser cleaning equipment for a mold. BACKGROUND

[0002] Mold is widely used in the fields of automobile, household appliance, electronics, communication, medical equipment, etc., and plays an important role in improving production efficiency, ensuring product quality, and reducing production cost, etc.

[0003] During the processing of the mold, residues (such as plastic coking, oil stains, sulfides, etc.) will be left in the parting surface, cavity, and flow channel of the mold, which will directly adhere to the surface of the newly produced product, resulting in problems such as scratches, material defects, surface defects (such as black spots, streaks), etc. on the finished product, and in severe cases, the product will be directly scrapped. For example, the residues left in the plastic mold will cause black spots on the surface of the subsequent injection molded parts that cannot be removed. The residues of aluminum slag in the die casting mold will scratch the surface of the cavity when the mold is closed, and the sulfides of the rubber mold will corrode the mold steel, which will shorten the maintenance cycle and overall service life of the mold, and increase the cost of replacing the mold. If the residues block the flow channel or the sprue of the mold, it will cause the raw material to fail to fill the cavity normally, forcing the production line to stop for cleaning, causing production delay. In addition, residues may decompose at high temperatures to produce harmful gases, or cause local overheating in the mold, posing equipment failure and even safety hazards. In addition, residues on the surface of the mold will change the actual size of the cavity (such as thickening of the residue layer, resulting in oversize products), or affect the flow speed and cooling efficiency of the raw material, causing size deviation and inconsistent weight of the same batch of products, which cannot meet the stability requirements of production.

[0004] The existing mold cleaning methods include manual cleaning: using a brush, a copper spatula, and sandpaper in combination with a cleaning agent to wipe. Chemical cleaning: using the dissolving or emulsifying action of solvents (such as neutral cleaning agents and scale removers) to remove oil stains. High-pressure water cleaning: using high-pressure water flow (50-150 MPa) to impact residues. Ultrasonic cleaning: high-frequency sound waves generate micro-bubbles that burst to peel off dirt. Dry ice cleaning: dry ice particles impact the mold at high speed, using low-temperature to embrittle the dirt and instant sublimation.

[0005] Traditional cleaning methods mainly include manual wiping, chemical soaking, and high-pressure water washing. If the mold is not disassembled, residues (such as plastic coking and oil stains) in critical areas such as the inside of the cavity, the parting surface gap, and the flow channel corner cannot be contacted by cleaning tools or cleaning agents, and cannot be completely removed, so the mold must be disassembled. Because the mold processing machine has a complex structure, is heavy in weight, and requires high precision, disassembly and assembly consume a lot of time, delay production time, and affect production efficiency.

[0006] In recent years, the emerging ultrasonic cleaning or dry ice cleaning also has many drawbacks. Online ultrasonic cleaning needs to integrate ultrasonic transducers into the fixed structure of the mold or equipment, which cannot be added arbitrarily later, and can only be designed in advance when new molds or equipment are modified, which has poor flexibility. During online cleaning, the cleaning liquid needs to be continuously circulated. If the cleaning liquid is not properly selected (such as strong corrosion and poor defoaming), it will not only affect the cleaning effect, but also may adhere to the mold surface, resulting in oil stains or defects in subsequent products; and the cleaning liquid needs to be replaced regularly, increasing the cost of consumables and waste liquid treatment.

[0007] The core shortcomings of dry ice cleaning are: high equipment and operation cost: the initial purchase price of a dry ice cleaning machine is usually tens of thousands to hundreds of thousands of yuan, and dry ice consumables need to be purchased continuously, and the long-term cost is much higher than that of traditional manual or chemical cleaning. In addition, dry ice cleaning has limitations: for thick layer, high temperature solidified stubborn residues (such as aluminum slag crust of die casting mold, heavy degree of coking of plastic mold), the impact force of dry ice particles is not enough, and it is difficult to completely remove them at one time, and multiple cleaning may be required. Environmental restrictions: a large amount of white mist is generated during the dry ice cleaning process, which may affect the operator's vision; and the sublimation of dry ice will absorb heat, causing the temperature of the mold surface to drop sharply, which may cause fine cracks if the mold material has poor thermal conductivity and the temperature difference is too large.

[0008] In summary, there is a need for a mold online laser cleaning device that can clean the mold without disassembling the mold to save the time consumed by disassembling the mold, improve production efficiency, save manufacturing costs, and does not require equipment modification. SUMMARY

[0009] The purpose of the present application is to provide a mold online laser cleaning device that can clean the mold without disassembling the mold to save the time consumed by disassembling the mold, improve production efficiency, save manufacturing costs, and does not require equipment modification.

[0010] To achieve the above-mentioned purpose, the present application provides a mold online laser cleaning device, which comprises: a general control system, a mechanical arm, a vision system, an image acquisition device and a laser cleaning head; the laser cleaning head, the mechanical arm and the vision system are connected with the general control system, the image acquisition device is connected with the vision system, the laser cleaning head is arranged at the end of the mechanical arm, and the image acquisition device is arranged on the side of the laser cleaning head; the image acquisition device is used for acquiring the image of a positioning object arranged on a mold machine table, and sending the image of the positioning object to the vision system; the vision system is used for processing the image of the positioning object by using a visual positioning algorithm to obtain an offset, and sending the offset to the general control system; and the general control system is used for controlling the movement trajectory of the mechanical arm according to the offset and a preset trajectory to clean the mold arranged on the mold machine table.

[0011] According to the specific embodiments provided in the application, the application has the following technical effects: the application provides a mold online laser cleaning equipment, a laser cleaning head is arranged, laser cleaning is adopted, the mold can be cleaned without disassembly to save the working hours consumed by mold disassembly and improve the production efficiency. Green cleaning is realized without cleaning liquid and manufacturing cost is saved. The cleaning head is driven by the mechanical arm to complete the cleaning, and equipment modification is not required. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0013] Figure 1 The front view of the mold online laser cleaning equipment provided by an embodiment of the application.

[0014] Figure 2 The structural diagram of the mold online laser cleaning equipment provided by an embodiment of the application.

[0015] Figure 3 The connection relationship diagram of the mold online laser cleaning equipment provided by an embodiment of the application.

[0016] Figure 4 The operation flowchart of the mold online laser cleaning equipment provided by an embodiment of the application.

[0017] The drawings show that: 1 is a general control system, 2 is a mechanical arm, 3 is an image acquisition device, 4 is a laser cleaning head, 5 is a push rod, 6 is an operation screen, 7 is a robot control box, and 8 is a battery box. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be described clearly and completely in the embodiments of the application in combination with the drawings. Obviously, the described embodiments only constitute some of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0019] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application will be further described in detail in combination with the drawings and specific embodiments.

[0020] Laser cleaning is a new technology based on laser and material interaction. Through the action of ultra-high peak, short pulse laser on the workpiece, the surface dirt, rust or coating absorbs laser and evaporates or peels off instantaneously, while the substrate hardly absorbs laser, so as to achieve the effect of removing surface dirt without damaging the substrate. Mold is a kind of mold and tool used in industrial production to obtain the required product by injection molding, blow molding, extrusion, die casting or forging forming, smelting, stamping and other methods. It realizes the processing of the shape of the article mainly through the change of the physical state of the formed material. It generally includes movable mold and fixed mold (or male mold and female mold). When they are separated, the workpiece is taken out, and when they are closed, the blank is injected into the mold cavity for forming. Mold cleaning is a key process to ensure product quality and prolong the service life of the mold. The core is to remove the residues (such as plastic coking, oil stains, sulfides, etc.) in the parting surface, cavity and runner, while avoiding damage to the surface of the mold.

[0021] In one exemplary embodiment, a mold online laser cleaning device is provided, as shown in Figures 1 to 3 including: a general control system 1, a mechanical arm 2, a vision system, an image acquisition device 3 and a laser cleaning head 4; the laser cleaning head 4, the mechanical arm 2 and the vision system are connected with the general control system 1, the image acquisition device 3 is connected with the vision system, the laser cleaning head 4 is arranged at the end of the mechanical arm 2, and the image acquisition device 3 is arranged at the side of the laser cleaning head 4; the image acquisition device 3 is used to acquire the image of the positioning object arranged on the mold machine table, and send the image of the positioning object to the vision system; the vision system is used to process the image of the positioning object by using a visual positioning algorithm, obtain an offset, and send the offset to the general control system 1; the general control system 1 is used to control the motion trail of the mechanical arm 2 according to the offset and a preset trail to clean the mold arranged on the mold machine table. The laser cleaning head 4 is used to guide the laser to clean the surface of the mold.

[0022] In actual application, the image acquisition device 3 is arranged at the tail end side of the laser cleaning head 4, which is used to shoot the work station two-dimensional code to determine the cleaning position deviation. After calculation by the general control system 1, the position of the mechanical arm is corrected to realize the positioning error of the hand, and the accurate positioning of the mold cleaning is realized.

[0023] In another exemplary embodiment of the present application, the mold online laser cleaning device further comprises a robot controller; the general control system 1 is connected with the mechanical arm 2 through the robot controller. The robot controller is controlled by the general control system 1 and is used for the motion control of the mechanical arm 2. The mechanical arm 2 is controlled by the robot control box 7 and is used for carrying the laser cleaning head 4 to the mold position for cleaning operation. The robot controller executes corresponding actions after receiving the instruction of the general control system 1, and completes the motion of different positions and postures of the mechanical arm 2 during cleaning.

[0024] In another example embodiment of the present application, the mold on-line laser cleaning device further comprises: a laser cleaning machine; the total control system 1 is connected with the laser cleaning head 4 through the laser cleaning machine.

[0025] In another example embodiment of the present application, the mold on-line laser cleaning device further comprises: a battery, which is connected with the total control system 1, the robot controller and the laser cleaning machine respectively, and is used for powering the whole system.

[0026] In another example embodiment of the present application, the mold on-line laser cleaning device further comprises: a push rod 5, a main box body and wheels; the push rod 5 is arranged on the main box body, and the wheels are arranged at the bottom of the main box body; the robot controller, the battery and the total control system 1 are arranged inside the main box body, and the first end of the mechanical arm 2 is arranged at the top end of the main box body. Specifically, the first end of the mechanical arm 2 is arranged at the middle part of the top end of the main box body.

[0027] In another example embodiment of the present application, the mold on-line laser cleaning device further comprises: an operation screen 6 arranged on the main box body, which is connected with the total control system 1. The total control system 1 is the control center of the whole cleaning system, which is used for coordinating the work of each component of the device, data acquisition, motion control, battery management, man-machine interface, providing alarm and operation log, etc. The operation screen 6 communicates with the total control system 1, which is used for device debugging, parameter setting, alarm and operation log query, etc.

[0028] In another example embodiment of the present application, the vision system comprises: a parameter acquisition module, which is used for acquiring the intrinsic matrix and distortion coefficient of the image acquisition device 3 after calibration, the four non-distortion pixel coordinates of the four vertices of the image of the positioning object, and the world coordinates of the four vertices of the image of the positioning object.

[0029] An external parameter determination module is configured to obtain the external parameter of the image acquisition device 3 according to the intrinsic matrix and distortion coefficient of the image acquisition device 3 after calibration, the four non-distortion pixel coordinates of the four vertices of the image of the positioning object, and the world coordinates of the four vertices of the image of the positioning object.

[0030] An offset determination module is configured to obtain the offset according to the external parameter of the image acquisition device 3.

[0031] In another example embodiment of the present application, the positioning object is a two-dimensional code.

[0032] In practical applications, each mold machine will make a basic positioning template, which is related to the positioning reference position and the relationship between the cleaning track. If the subsequent positioning deviates, the deviation value can be calculated by vision and compensated in the track. The vision system compares the deviation between the current position picture and the standard picture, calculates the positioning offset and angle offset. In two-dimensional code vision positioning, X and Y direction offset is the horizontal offset of the camera (or two-dimensional code carrier) in the two-dimensional code plane (world coordinate system XY plane, Z=0), and the angle offset is the rotation angle (Yaw angle) around the two-dimensional code plane normal (Z axis), which is derived through the PnP solution of the external parameter (translation vector t and rotation matrix R). The specific process is as follows: assuming that the camera calibration obtains the internal parameter matrix K and the distortion coefficient (the distortion is small, and the subsequent is simplified as "no distortion" to focus on the core calculation).

[0033] According to the internal parameter matrix K, the camera internal parameter is obtained, assuming that the focal length is 6.5mm, the pixel is 1280*720, and the principal point is (640, 360).

[0034] The two-dimensional code parameters are: the physical side length s=100mm, and the center is the world coordinate system origin , the world coordinates of the four vertices of the two-dimensional code are obtained according to the center and the physical side length of the two-dimensional code.

[0035] The four vertices of the two-dimensional code without distortion pixel coordinates are (790, 260), (490, 260), (490, 460), and (790, 460).

[0036] The camera internal parameter, distortion coefficient, world coordinates of the four vertices of the two-dimensional code, and the four vertices of the two-dimensional code without distortion pixel coordinates are substituted into the PnP algorithm (known public algorithm) to calculate the external parameter, which includes the translation vector and the rotation matrix.

[0037] The translation vector is: .

[0038] The rotation matrix is: .

[0039] X, Y direction offset calculation: the offset of the two-dimensional code relative to the camera is often used in engineering, and the component of the translation vector t is directly taken, X offset (left and right): △X=t x =15.2mm (the two-dimensional code is 15.2mm to the right of the camera).

[0040] Y offset (up and down): △Y=t y =-8.7mm (the two-dimensional code is 8.7mm below the camera).

[0041] Under small angle, Yaw angle (rotation around Z axis) is directly calculated by the first column of the rotation matrix: , and the calculation is substituted , indicates a two-dimensional code counterclockwise rotation 1.14°.

[0042] The final result is shown in Table 1.

[0043] Table 1 Offset Summary After the total control system 1 receives the offset calculated by the vision system, the data is given to the robot, and when the robot performs the cleaning task, the coordinates of each point on the originally set path are added to the offset, which is the actual walking track.

[0044] In another exemplary embodiment of the present application, the image acquisition device 3 is a camera.

[0045] In another exemplary embodiment of the present application, the mold on-line laser cleaning equipment further comprises a foot brake.

[0046] In actual application, the mold on-line laser cleaning equipment further comprises a robot control box 7 and a battery box 8; the robot controller is arranged in the robot control box 7, and the battery is arranged in the battery box 8; the robot control box 7 and the battery box 8 are both arranged in the main box body, the battery box 8 is arranged below the robot control box 7, and the total control system 1 is located above the battery box 8 and beside the robot control box 7.

[0047] In actual application, the mold on-line laser cleaning equipment further comprises a battery management system arranged in the battery box 8, which is controlled by the total control system 1 and is used for battery state monitoring.

[0048] As shown in Figure 1 , the mold on-line laser cleaning equipment provided by the present application is in the form of a closed portable trolley, the system main body is a rectangular closed box body, the bottom has wheels, and the rear side has a push rod 5. The box body bottom is provided with a robot control box 7, a battery box 8, and a total control system 1. The box body top is provided with a mechanical arm 2, the mechanical arm 2 end is provided with a laser cleaning head 4, and the laser cleaning head 4 side wall is provided with a vision system. The box body front end is provided with an operation screen 6 panel. The operation process of the mold on-line laser cleaning equipment provided by the present application is as shown in Figure 4 , and specifically includes the following steps.

[0049] Step 1: When the mold on-line laser cleaning equipment is idle, it is parked at a charging point for charging. When it is needed to clean the mold, the device is manually pushed to a position near the mold machine.

[0050] Step 2: The machine work point has a parking mark, which does not need to be too accurate (the vision system will take pictures to identify and correct the parking offset), after stopping roughly near the mark, the foot brake is pressed to stop the equipment. Then the power switch of the equipment is turned on to start the equipment.

[0051] Step 3: After the device is started, select the current machine at the front-end operation screen, confirm that the parameters are correct, and start the device with one key.

[0052] Step 4: After the device is started, the mechanical arm automatically moves to the vision shooting point of the machine, and then sends a command to notify the vision system that it has arrived at the shooting point.

[0053] Step 5: The vision system turns on the light source and starts shooting and sampling (a two-dimensional code picture is attached at the shooting point), and analyzes the photo image. After shooting is completed, the light source is turned off.

[0054] Step 6: The vision system compares the current picture with the standard picture deviation, calculates the offset (positioning offset and angle offset), and sends the data to the total control system. (Each machine will have a basic positioning template, which is related to the positioning reference position and the cleaning track. If there is a deviation in subsequent positioning, the deviation value can be calculated through vision and compensated in the track.)

[0055] Step 7: The total control system starts the cleaning process according to the machine number selected by the operator, sends the task number to the robot controller, and writes the offset into the register in the robot controller.

[0056] Step 8: The robot controller has pre-set all machine operation tracks. Each machine cleaning track corresponds to a task number. When receiving the task number sent by the total control system, the current task track action is executed, and the offset sent by the total control system is integrated into the track to correct the pre-set track, so that the track is synchronized with the actual parking position.

[0057] Step 9: When the mechanical arm reaches the starting point of the cleaning track, it sends a corresponding cleaning start signal to the total control system. After receiving the signal, the total control system controls the laser cleaning machine to turn on the laser.

[0058] Step 10: The mechanical arm continues to move forward according to the cleaning track. During this process, the laser cleans the surface of the mold. When the mechanical arm reaches the end of the cleaning track, it sends a signal to the total control system, which controls the laser to turn off and stop cleaning.

[0059] Step 11: The mechanical arm completes the cleaning track operation, the robot controller retracts the arm, returns to the safe standby position, and completes the operation. It also sends a signal to the total control system that it has returned to the safe position.

[0060] Step 12: The total control system prompts the completion of the operation through voice.

[0061] Step 13: After hearing the voice, the operator clicks the confirmation button on the operation panel, and the voice stops. Then release the trolley brake and push the trolley to the next machine operation position.

[0062] Step 14: Repeat the above steps until all the machines complete the cleaning operation.

[0063] Step 15: The operator disconnects the system power switch and pushes the trolley to the charging point.

[0064] Step 16: The device is automatically charged, and when the power is fully charged, it is automatically powered off. End.

[0065] The technical features of the above embodiments can be combined in any manner. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist, they should be considered as the scope of the present application.

[0066] The principles and implementation modes of the present application are described by applying specific examples herein, and the above embodiment descriptions are only used to help understand the method and its core idea of the present application; meanwhile, for those skilled in the art, the specific implementation modes and application ranges will be changed according to the idea of the present application. In conclusion, the content of the present application should not be understood as a limitation.

Claims

1. An online laser cleaning device for molds, characterized in that, The online laser cleaning equipment for molds includes: The system includes a central control system, a robotic arm, a vision system, an image acquisition device, and a laser cleaning head. The laser cleaning head, robotic arm, and vision system are all connected to the central control system. The image acquisition device is connected to the vision system. The laser cleaning head is located at the end of the robotic arm, and the image acquisition device is located on the side of the laser cleaning head. The image acquisition device is used to acquire images of the positioning objects set on the mold machine table and send the images of the positioning objects to the vision system. The vision system is used to process the images of the positioning objects using a visual positioning algorithm to obtain the offset, and then sends the offset to the central control system. The central control system is used to control the movement trajectory of the robotic arm according to the offset and the preset trajectory to clean the mold set on the mold machine table.

2. The online laser cleaning equipment for molds according to claim 1, characterized in that, The online laser cleaning equipment for molds also includes: a robot controller; the central control system is connected to the robotic arm through the robot controller.

3. The online laser cleaning equipment for molds according to claim 2, characterized in that, The online laser cleaning equipment for molds also includes: a laser cleaning machine; the central control system is connected to the laser cleaning head through the laser cleaning machine.

4. The online laser cleaning equipment for molds according to claim 3, characterized in that, The online laser cleaning equipment for molds also includes a battery, which is connected to the central control system, the robot controller, and the laser cleaning machine.

5. The online laser cleaning equipment for molds according to claim 4, characterized in that, The online laser cleaning equipment for molds also includes: a push rod, a main housing, and wheels; the push rod is located on the main housing, and the wheels are located at the bottom of the main housing; the robot controller, battery, and overall control system are all located inside the main housing, and the robotic arm is located at the top of the main housing.

6. The online laser cleaning equipment for molds according to claim 5, characterized in that, The online laser cleaning equipment for molds also includes an operation screen mounted on the main housing, which is connected to the central control system.

7. The online laser cleaning equipment for molds according to claim 1, characterized in that, The vision system includes: The parameter acquisition module is used to acquire the intrinsic parameter matrix and distortion coefficients of the image acquisition device after calibration, the distortion-free pixel coordinates of the four vertices of the image of the positioning object, and the world coordinates of the four vertices of the image of the positioning object. The extrinsic parameter determination module is used to obtain the extrinsic parameters of the image acquisition device based on the intrinsic parameter matrix and distortion coefficients after the image acquisition device is calibrated, the distortion-free pixel coordinates of the four vertices of the image of the positioning object, and the world coordinates of the four vertices of the image of the positioning object. The offset determination module is used to obtain the offset based on the external parameters of the image acquisition device.

8. The online laser cleaning equipment for molds according to claim 1, characterized in that, The location is indicated by a QR code.

9. The online laser cleaning equipment for molds according to claim 1, characterized in that, The image acquisition device is a camera.

10. The online laser cleaning equipment for molds according to claim 5, characterized in that, The online laser cleaning equipment for molds also includes a foot brake.

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