Grinding abrasive belt grinding equipment and grinding control method

Abstract

The invention discloses grinding abrasive belt grinding equipment. The equipment comprises a rack; the polishing device comprises two polishing mechanisms arranged in the vertical direction, each polishing mechanism comprises a torque motor, a force output mechanism, a posture adjusting mechanism and a contact wheel mechanism, the torque motors and the force output mechanisms are arranged on the rack, the torque motors are provided with encoders, rotating shafts of the torque motors are connected with the posture adjusting mechanisms, and the contact wheel mechanisms are connected with the force output mechanisms. The force output mechanism comprises an air cylinder, a displacement sensor arranged on the air cylinder and a force sensor connected with a piston rod of the air cylinder, the force sensor is hinged to the posture adjusting mechanism, the posture adjusting mechanism is connected with the contact wheel mechanism, and abrasive belts are wound on the posture adjusting mechanism and the contact wheel mechanism; and the driving mechanism is used for driving the abrasive belt to move. The invention further discloses a grinding method of the grinding abrasive belt. Under the condition that the grinding force continuously changes, timely and quick response can be achieved, the grinding amount with small changes and large changes can be effectively controlled, and the grinding precision is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of grinding machining automation, and particularly relates to a grinding belt polishing device and a polishing control method. Background Art

[0002] With the continuous advancement of the industrial automation process, in the traditional polishing field, robotic automation devices are increasingly used to replace manual grinding machining. However, in actual grinding machining, the following defects exist: 1) In most automated grinding devices, the contact wheel part is not gravity-balanced. As a result, during the grinding process, on the one hand, the output force of the cylinder needs to overcome a large gravity, and at the same time, it needs to output an appropriate grinding machining force. Since the cylinder outputs force through gas compression, this brings a certain hysteresis and cannot respond promptly and quickly to the change in the required force of the grinding control target; 2) During the grinding process of the grinding belt, a large amount of grinding heat is easily generated, and the heat dissipation range per unit cross-section of the grinding belt is small. Therefore, the grinding belt with a shorter circumference often has a shorter service life; 3) For a single grinding belt grinding end device, its end contact wheel part easily absorbs a large amount of heat during the grinding process. Especially for some difficult-to-machine materials, it is more likely to cause the shortening of the service life of the contact wheel part; 4) For conjoined workpieces or workpieces with more curvature changes, for a single grinding belt grinding device, it is necessary to continuously change the position and posture between the complex workpiece and the contact wheel during the polishing process to adapt to the changes in the convex and concave planes, which not only affects the efficiency but also some postures cannot be achieved by the robot, easily affecting its machining accuracy. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a grinding belt polishing device and a polishing control method.

[0004] To achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0005] A grinding belt polishing device, comprising:

[0006] A frame;

[0007] A polishing device, including two polishing mechanisms arranged in the vertical direction. Each of the polishing mechanisms includes a torque motor, a force output mechanism, an attitude adjustment mechanism, and a contact wheel mechanism. The torque motor and the force output mechanism are both arranged on the frame. The torque motor is configured with an encoder, and the rotating shaft of the torque motor is connected to the attitude adjustment mechanism. The force output mechanism includes a cylinder, a displacement sensor arranged on the cylinder, and a force sensor connected to the piston rod of the cylinder. The force sensor is hinged to the attitude adjustment mechanism, and the attitude adjustment mechanism is connected to the contact wheel mechanism. Sand belts are wound around both the attitude adjustment mechanism and the contact wheel mechanism;

[0008] A driving mechanism for driving the movement of the abrasive belt.

[0009] As a further improvement of the present invention, two support plates are relatively arranged on one side of the attitude adjustment mechanism in the front - rear direction, at least part of the force sensor is located between the two support plates, and a pin shaft is connected between the force sensor and the support plates.

[0010] As a further improvement of the present invention, the contact wheel mechanism includes a side plate, a contact wheel arranged at one end of the side plate, and two adjusting wheels relatively arranged on the side plate in the up - down direction, and the other end of the side plate is connected to the other side of the attitude adjustment mechanism.

[0011] As a further improvement of the present invention, the attitude adjustment mechanism includes a connecting rod extending in the up - down direction, two first tensioning wheel assemblies respectively connected to both ends of the connecting rod, the rotating shaft is connected to the middle of the connecting rod, and the first tensioning wheel assembly located above is connected to the side plate.

[0012] As a further improvement of the present invention, the cylinder is a non - damping cylinder.

[0013] As a further improvement of the present invention, each grinding mechanism further includes an abrasive belt tensioning mechanism, and the abrasive belt tensioning mechanism includes a tensioning cylinder member and a second tensioning wheel connected to the output rod of the tensioning cylinder member.

[0014] As a further improvement of the present invention, a deviation rectifying mechanism is further arranged on the frame.

[0015] As a further improvement of the present invention, it further includes a data acquisition and operation control function module, a terminal board, a human - machine interaction system and a control system. The displacement sensor and the control system are both connected to the data acquisition and operation control function module. The force sensor and the torque motor are both connected to the data acquisition and operation control function module through the terminal board, and the data acquisition and operation control function module is connected to the human - machine interaction system.

[0016] A grinding abrasive belt grinding control method using the grinding equipment, comprising the following steps:

[0017] (1) Real - time balance the gravity of the attitude adjustment mechanism and the contact wheel mechanism through the torque motor to ensure that under the thrust of the cylinder, after driving the contact wheel mechanism to any position, it can maintain the attitude of that position unchanged;

[0018] (2) Given the grinding force at the contact point when the complex - curved surface workpiece to be processed contacts the abrasive belt;

[0019] (3) The actual output force of the cylinder is fed back through the force sensor, while the contact position of the current contact point is fed back through the encoder of the torque motor, and the telescopic position value of the current cylinder is fed back through the displacement sensor;

[0020] (4) The equivalent force conversion and force response transfer function are fed back through the force sensor, the encoder of the torque motor, and the displacement sensor, and the output force required for the cylinder to output the contact wheel mechanism is calculated.

[0021] As a further improvement of the present invention, the equivalent force conversion and force response transfer function fed back by the force sensor, the encoder of the torque motor, and the displacement sensor are:

[0022]

[0023] Among them, F 张 is the tension force of the abrasive belt, F 气 is the output force of the cylinder, F is the resultant force received by the contact wheel, F t is the grinding tangential force, F n is the grinding normal force, M 电机 is the output balance torque of the torque motor, l1 to l7 are the force arms of each axis, α is the feedback rotation angle of the encoder, d 触 is the diameter of the contact wheel, mg is the combined gravity of the attitude adjustment mechanism and the contact wheel mechanism, F 气 ' is the actual output force of the cylinder fed back by the force sensor, K v is the amplifier gain coefficient, c0 is the adjustment coefficient, s is the transfer function variable, and d0, d1, d2 are the coefficients of each order.

[0024] The beneficial effects of the present invention are:

[0025] (1) The present invention solves the problem of rapid force response under the condition of continuously changing grinding force. The torque motor is used to balance the gravity, and the cylinder only needs to output a small thrust for grinding and responds quickly and timely. It can effectively control the grinding amount with large micro-changes, improve the grinding accuracy of the grinding contact point, and can effectively adapt to the real-time change of the target required force in the grinding control process, greatly improving the self-adaptability of the grinding processing of complex curved surface workpieces.

[0026] (2) The present invention adopts double-contact wheel grinding and a large-circumference abrasive belt, which can effectively dissipate heat, extend the service life of the abrasive belt and the contact wheel during the grinding process of complex curved surface workpieces, and improve the processing efficiency.

[0027] (3) The present invention has the advantages of high integration, compact structure and reliable performance, and can be effectively applied to small and medium-sized complex curved surfaces and components with high grinding accuracy requirements. Description of the Drawings

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 A perspective view of a preferred embodiment of the present invention;

[0030] Figure 2 A perspective view of another angle of a preferred embodiment of the present invention;

[0031] Figure 3 A sectional side view of a preferred embodiment of the present invention;

[0032] Figure 4 A sectional top view of a preferred embodiment of the present invention;

[0033] Figure 5 A software and hardware connection diagram of a preferred embodiment of the present invention;

[0034] Figure 6 A force diagram of a single attitude adjustment mechanism and a contact wheel mechanism of a preferred embodiment of the present invention;

[0035] In the figure: 1. Frame, 2. Grinding mechanism, 21. Torque motor, 211. Rotating shaft, 22. Force output mechanism, 221. Cylinder, 222. Displacement sensor, 224. Force sensor, 23. Attitude adjustment mechanism, 231. Support plate, 232. Pin shaft, 233. Link rod, 234. Sleeve, 235. Bearing, 236. Support shaft, 237. First tensioning wheel, 24. Contact wheel mechanism, 241. Side plate, 242. Contact wheel, 243. Adjusting wheel, 25. Sand belt tensioning mechanism, 251. Tensioning cylinder, 252. Second tensioning wheel, 3. Sand belt, 4. Driving mechanism, 5. Deviation rectifying mechanism, 51. Deviation rectifying cylinder, 52. Rotating wheel, 6. Data acquisition and operation control function module, 62. Terminal board, 63. Human-computer interaction system, 64. Control system. Detailed implementation manners

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Please refer toFigures 1-4 , an embodiment of the present application discloses a grinding belt polishing device, including:

[0038] A frame 1;

[0039] A polishing device, including two polishing mechanisms 2 arranged in the up and down direction. Each polishing mechanism 2 includes a torque motor 21, a force output mechanism 22, an attitude adjustment mechanism 23, and a contact wheel mechanism 24. The torque motor 21 and the force output mechanism 22 are both arranged on the frame 1. The torque motor 21 is configured with an encoder. The rotating shaft 211 of the torque motor 21 is connected to the attitude adjustment mechanism 23. The force output mechanism 22 includes a cylinder 221, a displacement sensor 222 arranged on the cylinder 221, and a force sensor 224 connected to the piston rod of the cylinder 221. The force sensor 224 is hinged to the attitude adjustment mechanism 23. The attitude adjustment mechanism 23 is connected to the contact wheel mechanism 24. Sand belts 3 are wound around both the attitude adjustment mechanism 23 and the contact wheel mechanism 24;

[0040] A driving mechanism 4 for driving the movement of the sand belt 3.

[0041] In the present invention, by setting the torque motor 21 to balance the gravity of the attitude adjustment mechanism 23 and the contact wheel mechanism 24, during the grinding process, a smaller thrust is output by the cylinder 221 for grinding, which can effectively adapt to the real-time change of the target required force in the grinding control process and respond quickly and timely. When accurately controlling the output force of the cylinder 221, the grinding amount with large small changes can be effectively controlled, the grinding accuracy at the grinding contact point can be improved, and the response duration can be shortened. The present invention is provided with two polishing mechanisms 2, which extends the perimeter of the sand belt 3, can effectively dissipate heat, extends the service life of the sand belt 3, can grind two workpieces to be processed simultaneously, and improves the processing efficiency.

[0042] In this embodiment, please refer to Figure 1 , Figure 4 . On one side of the attitude adjustment mechanism 23, two support plates 231 are oppositely arranged in the front and back direction. At least part of the force sensor 224 is located between the two support plates 231. The force sensor 224 and the support plate 231 are connected by a pin shaft 232.

[0043] Please refer to Figure 1 . The contact wheel mechanism 24 includes a side plate 241, a contact wheel 242 arranged at one end of the side plate 241, and two adjusting wheels 243 oppositely arranged in the up and down direction on the side plate 241. The other end of the side plate 241 is connected to the other side of the attitude adjustment mechanism 23.

[0044] Preferably, the attitude adjustment mechanism 23 includes a connecting rod 233 extending in the vertical direction, and two first tension wheel assemblies respectively connected to both ends of the connecting rod 233. The rotating shaft 211 is connected to the middle of the connecting rod 233, and the first tension wheel assembly located above is connected to the side plate 241. The attitude adjustment mechanism 23 and the contact wheel mechanism 24 are connected as a whole, and the attitude adjustment mechanism 23 and the contact wheel mechanism 24 rotate around the axis of the rotating shaft 211 to realize the change of the overall position and attitude of the attitude adjustment mechanism 23 and the contact wheel mechanism 24. Preferably, the first tension wheel assembly includes a sleeve 234, a bearing 235 arranged in the sleeve 234, and a first tension wheel 237 connected to the bearing 235 through a support shaft 236.

[0045] Preferably, the air cylinder 221 is a damped air cylinder, which improves the stability of the output force and the timeliness of the response.

[0046] Preferably, each grinding mechanism 2 further includes a sand belt tensioning mechanism 25. The sand belt tensioning mechanism 25 includes a tensioning air cylinder 251 and a second tension wheel 252 connected to the output rod of the tensioning air cylinder 251. The tensioning force of the sand belt 3 is adjusted by driving the second tension wheel 252 to move through the tensioning air cylinder 251.

[0047] In order to avoid the deviation of the sand belt 3, preferably, a deviation rectifying mechanism 5 is further provided on the frame 1. The deviation rectifying mechanism 5 may be provided with a deviation rectifying cylinder 51 and a rotating wheel 52 rotating relative to the deviation rectifying cylinder 51. If the axial direction of the deviation rectifying cylinder 51 is set as the Y direction, and the direction perpendicular to the axial direction is set as the X direction, then the sand belt 3 can be restored to its original position by adjusting the deviation rectifying cylinder 51 so that the deviation rectifying cylinder 51 rotates around the X direction.

[0048] Preferably, the encoder is an angle encoder. The angle encoder can be arranged on the rotating shaft 211.

[0049] Please refer to Figure 5 , and further includes a data acquisition and operation control function module 61, a terminal board 62, a human-machine interaction system 63, and a control system 64. The displacement sensor 222 and the control system 64 are both connected to the data acquisition and operation control function module 61. The force sensor 224 and the torque motor 21 are both connected to the data acquisition and operation control function module 61 through the terminal board 62. The data acquisition and operation control function module 61 is connected to the human-machine interaction system 63.

[0050] First, the gravity of the attitude adjustment mechanism 23 and the contact wheel mechanism 24 is balanced by the torque motor 21. When the complex curved surface workpiece to be machined contacts the abrasive belt 3, the grinding force at the contact point is given through the human-machine interaction system 63. At the same time, the data of the force sensor 224, the angle encoder, and the displacement sensor 222 are respectively collected through the data acquisition and operation control function module 61, and calculations are performed to obtain the output force of the air cylinder 221. The control system 64 controls the proportional solenoid valve and the directional solenoid valve through the magnitude of this output force, so that the air cylinder 221 provides a thrust for the contact wheel mechanism 24 to change the position and attitude between the contact wheel 242 and the complex curved surface workpiece to adapt to the changes in the concave and convex surfaces of the complex curved surface workpiece, effectively controlling the large grinding amount with small changes and improving the grinding accuracy at the grinding contact point.

[0051] The embodiment of the present application also discloses a grinding abrasive belt grinding control method, using the above-mentioned grinding equipment, including the following steps:

[0052] (1) The gravity of the attitude adjustment mechanism 23 and the contact wheel mechanism 24 is balanced in real time through the torque motor 21 to ensure that, under the thrust of the air cylinder 221, the contact wheel mechanism 24 can maintain the attitude of this position unchanged at any position;

[0053] (2) When the complex curved surface workpiece to be machined contacts the abrasive belt 3, the output grinding force at the contact point is given;

[0054] (3) The actual output force of the current air cylinder 221 is fed back through the force sensor 224, the contact position of the current contact point is fed back through the encoder of the torque motor 21, and the telescopic position value of the current air cylinder 221 is fed back through the displacement sensor 222;

[0055] (4) The output force required for the air cylinder 221 to output the contact wheel mechanism 24 is calculated through the equivalent force conversion and force response transfer function fed back by the force sensor 224, the encoder of the torque motor 21, and the displacement sensor 222.

[0056] Preferably, the encoder is an angle encoder.

[0057] Please refer to Figure 6 , the equivalent force conversion and force response transfer function fed back by the force sensor 224, the encoder of the torque motor 21, and the displacement sensor 222 is:

[0058]

[0059] Among them, F 张 is the tension of the abrasive belt 3, F 气 is the output force of the air cylinder 221, F is the resultant force received by the contact wheel 242, F t is the grinding tangential force, F n is the grinding normal force, M 电机To output a balanced torque by the torque motor 2, l1 to l7 are the arm lengths of each axis, α is the rotation angle feedback by the encoder, and d 触 is the diameter of the contact wheel 242, mg is the combined gravity of the attitude adjustment mechanism 23 and the contact wheel mechanism 24, and F 气 ' is the actual output force of the feedback cylinder 221 of the force sensor 224, and K v is the amplifier gain coefficient, c0 is the adjustment coefficient, s is the transfer function variable, and d0, d1, and d2 are the coefficients of each order.

[0060] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0061] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A grinding abrasive belt polishing device, characterized in that, Comprising: A frame; A grinding device, including two grinding mechanisms arranged in the up-and-down direction. Each of the grinding mechanisms includes a torque motor, a force output mechanism, an attitude adjustment mechanism, and a contact wheel mechanism. The torque motor and the force output mechanism are both arranged on the frame. The torque motor is equipped with an encoder. The rotating shaft of the torque motor is connected to the attitude adjustment mechanism. The force output mechanism includes a cylinder, a displacement sensor arranged on the cylinder, and a force sensor connected to the piston rod of the cylinder. The force sensor is hinged to the attitude adjustment mechanism. The attitude adjustment mechanism is connected to the contact wheel mechanism. Sand belts are wound around both the attitude adjustment mechanism and the contact wheel mechanism; A driving mechanism for driving the movement of the sand belt.

2. The abrasive belt grinding equipment according to claim 1, characterized in that On one side of the attitude adjustment mechanism, two support plates are arranged opposite to each other in the front-back direction. At least part of the force sensor is located between the two support plates. The force sensor and the support plates are connected by a pin shaft.

3. The abrasive belt grinding device according to claim 1, characterized in that, The contact wheel mechanism includes a side plate, a contact wheel arranged at one end of the side plate, and two adjustment wheels arranged opposite to each other in the up-and-down direction on the side plate. The other end of the side plate is connected to the other side of the attitude adjustment mechanism.

4. The abrasive belt grinding equipment according to claim 3, characterized in that, The attitude adjustment mechanism includes a connecting rod extending in the up-and-down direction and two first tension wheel assemblies respectively connected to both ends of the connecting rod. The rotating shaft is connected to the middle of the connecting rod. The upper first tension wheel assembly is connected to the side plate.

5. The abrasive belt grinding equipment according to claim 1, characterized in that, The cylinder is a damped cylinder.

6. The abrasive belt grinding equipment according to claim 1, characterized in that, Each of the grinding mechanisms further includes a sand belt tensioning mechanism. The sand belt tensioning mechanism includes a tensioning cylinder part and a second tension wheel connected to the output rod of the tensioning cylinder part.

7. The abrasive belt grinding equipment according to claim 1, characterized in that, A deviation rectifying mechanism is further arranged on the frame.

8. The abrasive belt grinding device according to claim 1, characterized in that, It further includes a data acquisition and operation control function module, a terminal board, a human-machine interaction system, and a control system. The displacement sensor and the control system are both connected to the data acquisition and operation control function module. The force sensor and the torque motor are both connected to the data acquisition and operation control function module through the terminal board. The data acquisition and operation control function module is connected to the human-machine interaction system.

9. A grinding belt grinding control method, characterized in that, Using the grinding sand belt grinding equipment according to any one of claims 1-8, including the following steps: (1) Real-time balance the gravity of the attitude adjustment mechanism and the contact wheel mechanism through the torque motor to ensure that under the thrust of the cylinder, after driving the contact wheel mechanism to any position, it can maintain the attitude of that position unchanged; (2) Given the output grinding force at the contact point in the case where the complex curved surface workpiece to be processed is in contact with the sand belt; (3) Feedback the actual output force of the current cylinder through the force sensor, feedback the current contact position of the contact point through the encoder of the torque motor, and feedback the current telescopic position value of the cylinder through the displacement sensor; (4) Calculate the output force required for the cylinder to output the contact wheel mechanism through the equivalent force conversion and force response transfer function feedback of the force sensor, the encoder of the torque motor, and the displacement sensor.

10. The grinding belt grinding control method according to claim 9, characterized in that, The feedback of the force sensor, the encoder of the torque motor, and the displacement sensor, etc., for the equivalent force conversion and the force response transfer function is as follows: Among them, F 张 is the tension force of the abrasive belt, F 气 is the output force of the cylinder, F is the resultant force received by the contact wheel, F t is the grinding tangential force, F n is the grinding normal force, M 电机 is the output balance torque of the torque motor, l1 to l7 are the force arms of each axis, α is the encoder feedback rotation angle, d 触 is the diameter of the contact wheel, mg is the combined gravity of the attitude adjustment mechanism and the contact wheel mechanism, F 气 ' is the actual output force of the force sensor feedback cylinder, K v is the amplifier gain coefficient, c0 is the adjustment coefficient, s is the transfer function variable, d0, d1, d2 are the coefficients of each order.

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