Variable cross-section complex inner surface magnetic force lapping device with adaptive magnetic gap and method thereof

Abstract

The application discloses a variable cross-section complex inner surface magnetic force grinding device with an adaptive magnetic gap and a method thereof, and has the characteristics that the device comprises a servo motor power part, a two-axis positioning device part, an adaptive magnetic gap control part and a variable cross-section complex inner surface workpiece clamping part; the application combines electromagnetic field theory and magnetic force grinding technology, and invents the adaptive magnetic gap control device to solve the problem of the non-constant excitation gap in the magnetic force grinding process of the variable cross-section complex inner surface workpiece; in addition, the two-axis positioning device is designed to realize accurate feeding in the magnetic force grinding process; the four-jaw chuck clamps a flange on one side of the workpiece to be processed, and a telescopic ejector pin is used to tightly press the other side, so that the grinding processing stability is improved; and the device has the advantages of low manufacturing cost, simple and convenient operation, novel structure and good reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic force polishing, in particular to a variable cross-section complex inner surface magnetic force polishing device with adaptive magnetic gap and a method thereof. BACKGROUND

[0002] With the rapid development of science and technology, many industries have higher requirements for the finishing effect of the surface of complex-shaped parts. Waveguide is used to transmit ultrahigh frequency electromagnetic waves, and through it, pulse signals can be transmitted to the destination with minimal loss. Its inner wall must be very smooth to reduce the loss in the process of electromagnetic wave transmission. During the metal 3D printing forming process, defects such as spheroidization and porosity are prone to occur, and after the forming is completed, the residual stress in the part will cause the part to deform and crack during cooling. The surface quality that can be achieved by metal 3D printing technology cannot fully meet the use requirements of industrial applications.

[0003] Magnetic force polishing technology has good flexibility, self-sharpening and controllability, and can be used for external cylindrical surface, internal cylindrical surface, plane, small pipeline, complex curved surface and other situations. At present, the magnetic force polishing technology in the polishing of the inner surface of the part is mainly aimed at simple shape and large diameter pipe fittings, and cannot effectively complete the finishing machining of the variable cross-section complex inner surface pipe fitting. SUMMARY

[0004] The purpose of the present application is to solve the problem of inconvenient grinding of the inner surface of the variable cross-section complex inner surface pipe fitting. A variable cross-section complex inner surface magnetic force polishing device with adaptive magnetic gap is designed, and a corresponding grinding method is invented. By automatically adjusting the current intensity to change the magnetic field strength generated by the electromagnet, the telescopic rod and the outer surface of the pipe fitting are kept in a tight state, and the adaptive control of the excitation gap during the grinding process is realized. The grinding efficiency of the magnetic abrasive particles is improved. Under the combined action of pipe rotation, abrasive particle gravity and permanent magnet reciprocating motion, the magnetic abrasive particles reciprocate in the horizontal and vertical directions, making the grinding more uniform and efficient.

[0005] One of the technical solutions of the present application is:

[0006] A variable cross-section complex inner surface magnetic force polishing device with adaptive magnetic gap, characterized in that it comprises: a servo motor power part, a two-axis positioning device part, an adaptive magnetic gap control part, and a variable cross-section complex inner surface workpiece clamping part.

[0007] The servo motor power part is used to provide power for the X-axis ball screw sliding table 2 and the Y-axis ball screw sliding table 6 and realize precise feeding. The servo motor power part comprises an X-axis servo motor, a Y-axis servo motor, an encoder, a controller and a driver. The position and feeding speed of the telescopic rod 18 can be accurately controlled;

[0008] The two-axis positioning device part comprises a device base plate 1, an X-axis ball screw sliding table 2, an X-axis sliding block 3, a Y-axis L-shaped support plate 4, a Y-axis ball screw sliding table 6 and a Y-axis sliding block 7. The adaptive magnetic gap control part completes accurate tool setting before magnetic force grinding and precise feeding during the process;

[0009] The adaptive magnetic gap control part comprises a Z-axis sliding block 9, a Z-axis linear guide rail 8, a sliding variable resistor 11, a telescopic rod clamp 12, a telescopic rod 18, an electromagnet 14, an electromagnet mounting platform 13, a spring 19, a U-shaped block 17, a permanent magnet 20, a hook spring 10, a spring washer 22, a pad 15 and a support plate 16. The electromagnet 14 is fixed on the electromagnet mounting platform 13 by screws; the pad 15 is connected with the electromagnet mounting platform 13 by the hook spring 10, so as to prevent the adaptive magnetic gap control part from being displaced greatly in the Z-axis direction and causing a processing accident; the pad is fixed on the Z-axis sliding block 9 by bolts, so as to realize the stable displacement of the adaptive magnetic gap control part in the Z-axis direction; the U-shaped block 17 and the support plate 16 are fixed on the pad by bolts, so as to prevent the adaptive magnetic gap control part from interfering with the top of the Z-axis guide rail; the spring 19 is sleeved on one side of the telescopic rod 18, the telescopic rod 18 is installed in the groove of the U-shaped block 17 through a linear bearing sleeve, the tail end of the telescopic rod 18 is connected with the sliding variable resistor 11 through the telescopic rod clamp 12, and the sliding variable resistor is fixed on the support plate 16; the permanent magnet 20 is fixed between the two telescopic rods through a linear bearing sleeve, and a gap is kept between the permanent magnet and the electromagnet. The two telescopic rods and the permanent magnet are connected by the spring washer 22, so as to realize the synchronous movement in the Z-axis direction;

[0010] The variable cross-section complex inner surface workpiece clamping part comprises a motor, a four-jaw chuck, a baffle and a telescopic ejector pin. The four-jaw chuck clamps the flange on one side of the workpiece to be processed 21, and the baffle is installed on the other side and is tightly pressed by the telescopic ejector pin. In the processing process, high rotating speed can be achieved, and the workpiece can be prevented from moving during rotation, so that the stability of the grinding process is improved.

[0011] The Y-axis sliding block drives the whole device to move along the axial direction of the workpiece, and the X-axis sliding block drives the whole processing device to move forward and backward, so that the tool setting function is realized. The Z-axis sliding block drives the whole processing device to move upward to ensure that the permanent magnet keeps in contact with the workpiece.

[0012] The second technical scheme of the present application is:

[0013] A variable cross-section complex inner surface magnetic force grinding device and method with adaptive magnetic gap, comprising the following steps:

[0014] 1) A proper amount of magnetic abrasive and grinding liquid is filled in the variable cross-section complex inner surface pipe, and the variable cross-section complex inner surface pipe is clamped on the workpiece clamping part.

[0015] 2) Adjust the servo motor 5 of the two-axis positioning device, so that the magnetic pole head of the permanent magnet 20 on the adaptive magnetic gap control part reaches the appropriate machining position;

[0016] 3) Adjust the magnetic field strength of the electromagnet 14 by adjusting the current intensity, so that the magnetic pole head of the permanent magnet 20 and the workpiece 21 with a complex inner surface of variable cross-section have a suitable machining gap;

[0017] 4) First, start and adjust the X-axis servo motor, so that the telescopic rod tightly presses the outer surface of the pipe, completing the tool setting; then adjust the Y-axis servo motor, so that the adaptive magnetic gap control part moves horizontally within a suitable range; finally, start the DC motor of the clamp part, so that the pipe rotates at a high speed;

[0018] 5) Under the action of the compound motion, the magnetic abrasive continuously rolls, collides and scratches, achieving grinding processing of the inner surface of the workpiece; as the permanent magnet 20 feeds in the Y-axis direction, the excitation gap between the permanent magnet and the workpiece tends to increase due to the decreasing cross-section of the workpiece 21, the telescopic rod 18 is displaced downward, the resistance of the sliding rheostat 11 is reduced through the telescopic rod tail sleeve, the current intensity of the electromagnet 14 is increased, thereby generating a stronger magnetic field force acting on the permanent magnet, so that the telescopic rod and the workpiece are kept in a tightly pressed state, realizing the self-adaptive control of the excitation gap during the magnetic force grinding processing of the pipe with a complex inner surface of variable cross-section;

[0019] 6 After the processing is completed, the power supply of the cutting device is turned off, the pipe is removed and post-processing is performed.

[0020] The beneficial effects of the present application are:

[0021] The present application has the advantages of low manufacturing cost, simple and convenient operation, novel structure and good reliability.

[0022] The present application changes the magnetic field strength generated by the electromagnet by automatically adjusting the current intensity, so that the telescopic rod and the outer surface of the pipe are kept in a tightly pressed state, realizing the self-adaptive control of the excitation gap during the grinding process. The grinding efficiency of the magnetic abrasive is improved. Under the combined action of the pipe rotation, the gravity of the abrasive itself and the reciprocating motion of the permanent magnet, the magnetic abrasive reciprocates in the horizontal and vertical directions, making the grinding more uniform and efficient.

[0023] The present application greatly improves the grinding efficiency of the abrasive, and the combination of the two reciprocating motions makes the grinding more efficient and uniform. Through the polishing of the present magnetic force grinding device, the inner surface roughness of the pipe with a complex inner surface of variable cross-section can be efficiently reduced from Ra10 or above to Ra2 or below. The device has the advantages of simple structure, convenient operation, easy control and good reliability. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1It is a schematic diagram of the overall structure of the present application.

[0025] Figure 2 It is a side view of the overall device of the present application.

[0026] In the figure: 1, device base plate; 2, X-axis direction ball screw slide; 3, X-axis slide block; 4, Y-axis L-shaped support plate; 5, servo motor; 6, Y-axis direction ball screw slide; 7, Y-axis slide block; 8, Z-axis linear guide rail; 9, Z-axis slide block; 10, hook spring; 11, sliding rheostat; 12, telescopic rod clamp; 13, electromagnet mounting platform; 14, electromagnet; 15, cushion block; 16, support plate; 17, U-shaped block; 18, telescopic rod; 19, spring; 20, permanent magnet; 21, workpiece; 22, spring washer. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with the accompanying drawings and examples, but the present application is not limited only to the disclosed content of the examples. EXAMPLE

[0028] As Figure 1 shown:

[0029] A variable cross-section complex inner surface magnetic force lapping device with adaptive magnetic gap, which comprises a servo motor power part composed of an X-axis servo motor, a Y-axis servo motor, an encoder, a controller and a driver, which provides power for the X-axis direction ball screw slide and the Y-axis direction ball screw slide and realizes precise feeding, and a two-axis positioning device part composed of a device base plate, an X-axis direction ball screw slide, an X-axis slide block, a Y-axis L-shaped support plate, a Y-axis direction ball screw slide, a Y-axis slide block, a Z-axis linear guide rail, a Z-axis slide block, a hook spring, a sliding rheostat, a telescopic rod clamp, an electromagnet mounting platform, an electromagnet, a cushion block, a support plate, a U-shaped block, a telescopic rod, a spring and a permanent magnet. Figure 1 The X-axis direction ball screw slide is designed from back to front, the X-axis slide block is purchased conveniently, the Y-axis direction ball screw slide is purchased conveniently, and the Y-axis slide block is purchased conveniently. Figure 1The L-shaped support plate is self-processed, the Y-axis direction ball screw sliding table and the Y-axis sliding block are composed. The adaptive magnetic gap control part is composed of the Z-axis sliding block, the Z-axis linear guide rail, the sliding rheostat, and the telescopic rod clamp. It is convenient to purchase and easy to install. The telescopic rod is self-designed and processed. The electromagnet and the spring are convenient to purchase. The electromagnet installation platform is installed on the upper end of the Z-axis linear guide rail. The U-shaped block is a detachable structure. After one side of the telescopic rod is installed and fixed, the other end is fixed. The permanent magnet and the hook spring are directly purchased. The cushion block and the support plate are self-designed according to the actual processing condition. The electromagnet 14 is fixed on the electromagnet installation platform 13 through a screw. The cushion block 15 is connected with the electromagnet installation platform 13 through the hook spring 10, so that the adaptive magnetic gap control part is prevented from being displaced in the Z-axis direction to cause a processing accident. The cushion block 15 is fixed on the Z-axis sliding block 9 through a bolt, so that the adaptive magnetic gap control part is stably displaced in the Z-axis direction. The U-shaped block 17 and the support plate 16 are fixed on the cushion block through a bolt, so that the adaptive magnetic gap control part is prevented from interfering with the top of the Z-axis linear guide rail 8. The spring 19 is sleeved on one side of the telescopic rod 18. The telescopic rod is installed in the U-shaped block groove through a linear bearing sleeve. The telescopic rod tail is connected with the sliding rheostat 11 through the telescopic rod clamp 12. The sliding rheostat is fixed on the support plate. The permanent magnet 20 is fixed between the two telescopic rods through a linear bearing sleeve, and a gap is kept between the permanent magnet and the electromagnet. The two telescopic rods and the permanent magnet are connected through the spring washer 22, so that the synchronous movement in the Z-axis direction is realized.

[0030] The variable cross-section complex inner surface workpiece 21 is clamped on one side flange through a four-jaw chuck, and the other side is installed with a baffle and a telescopic pin (not shown in the figure, which is a conventional clamping fixture). The workpiece is a certain type of waveguide tube. The cross-section gradually increases along the axial direction (Y direction). The workpiece can rotate (rotate around the Y axis) under the drive of the motor in the clamping part. The adaptive magnetic gap control part is installed on the Z-axis (up-down moving shaft) sliding block through the cushion block. The telescopic rod can move up and down along the Z-axis with the change of the cross-section of the workpiece. The Z-axis guide rail is installed on the Y-axis sliding block. Under the drive of the servo motor, the adaptive magnetic gap control part can move left and right in the Y-axis direction, so as to realize precise feeding. The Y-axis direction ball screw is connected with the X-axis sliding block 3 through the Y-axis L-shaped support plate 4, so as to realize accurate tool setting during processing. The magnetic abrasive is shaped and covered on the complex inner surface of the workpiece under the action of the magnetic field. Under the action of the up-down reciprocating motion of the adaptive magnetic gap control part and the rotation of the workpiece, the uniform grinding of the complex inner surface of the workpiece is realized. EMBODIMENT

[0031] A variable cross-section complex inner surface magnetic force grinding device with adaptive magnetic gap and a method thereof, comprising the following steps:

[0032] 1) A proper amount of magnetic abrasive and grinding liquid are filled in the variable cross-section complex inner surface workpiece 21. The workpiece clamping part is clamped with the variable cross-section complex inner surface pipe.

[0033] 2) Adjust the servo motor 5 of the two-axis positioning device, so that the magnetic pole head of the permanent magnet 20 on the adaptive magnetic gap control part reaches the appropriate machining position;

[0034] 3) Adjust the magnetic field strength of the electromagnet 14 by adjusting the current intensity, so that the magnetic pole head of the permanent magnet 20 and the pipe with a complex inner surface with variable cross-section have a suitable machining gap;

[0035] 4) First, start and adjust the X-axis servo motor, so that the telescopic rod tightly presses the outer surface of the pipe, and the tool is completed; then adjust the Y-axis servo motor, so that the adaptive magnetic gap control part moves horizontally within the appropriate range; finally, start the DC motor of the clamp part, so that the pipe rotates at a high speed;

[0036] 5) Under the action of the combined motion, the magnetic abrasive continuously rolls, collides and scratches, achieving the grinding of the inner surface of the workpiece; as the permanent magnet feeds in the Y-axis direction, the cross-section of the workpiece 21 becomes smaller, the excitation gap between the permanent magnet 20 and the workpiece becomes larger, the telescopic rod 18 moves downward, the resistance of the sliding rheostat 11 is reduced through the telescopic rod tail sleeve, the current intensity of the electromagnet 14 is increased, thereby generating a stronger magnetic field force acting on the permanent magnet, so that the telescopic rod and the workpiece are kept in a tightly pressed state, and the adaptive control of the excitation gap during the magnetic force grinding of the pipe with a complex inner surface with variable cross-section is realized;

[0037] 6) After the machining is completed, the power of the cutting device is turned off, the pipe is removed and post-processing is performed.

[0038] The present application adjusts the current intensity to change the magnetic field strength generated by the electromagnet, so that the telescopic rod and the outer surface of the pipe are kept in a tightly pressed state, and the adaptive control of the excitation gap during the grinding process is realized. The grinding efficiency of the magnetic abrasive particles is improved. Under the combined action of the rotation of the pipe, the gravity of the abrasive particles and the reciprocating motion of the permanent magnet, the magnetic abrasive particles move reciprocatingly in the horizontal and vertical directions, making the grinding more uniform and efficient.

[0039] The grinding efficiency of the abrasive particles is improved, and the use of two reciprocating motions makes the grinding more efficient and uniform. Through the polishing of the present magnetic force grinding device, the inner surface roughness of the pipe with a complex inner surface with variable cross-section can be efficiently reduced from Ra10 or more to Ra2 or less.

[0040] The parts not involved in the present application are the same as or can be realized by the existing technology.

Claims

1. A variable cross-section complex inner surface magnetic abrasive finishing device with self-adapting magnetic gap, characterized in that, It comprises: a servo motor power part; the servo motor power part can accurately control the position and feeding speed of the telescopic rod (18); a two-axis positioning device part; the two-axis positioning device part enables the adaptive magnetic gap control part to complete accurate tool setting before magnetic force grinding and precise feeding during the process; an adaptive magnetic gap control part; the adaptive magnetic gap control part comprises a Z-axis sliding block (9), a Z-axis linear guide rail (8), a sliding rheostat (11), a telescopic rod clamp (12), a telescopic rod (18), an electromagnet (14), an electromagnet mounting platform (13), a spring (19), a U-shaped block (17), a permanent magnet (20), a hook spring (10), a spring washer (22), a pad (15) and a support plate (16); the electromagnet (14) is fixed on the electromagnet mounting platform (13) by screws; the pad (15) is connected with the electromagnet mounting platform (13) by the hook spring (10), preventing the adaptive magnetic gap control part from being displaced greatly in the Z-axis direction and causing processing accidents; the pad is fixed on the Z-axis sliding block (9) by bolt connection, realizing smooth displacement of the adaptive magnetic gap control part in the Z-axis direction; the U-shaped block (17) and the support plate (16) are fixed on the pad by bolt connection, preventing interference between the adaptive magnetic gap control part and the top of the Z-axis guide rail; the spring (19) is sleeved on the telescopic rod (18) and the permanent magnet (20) on one side, the telescopic rod (18) is installed in the U-shaped block (17) slot through a linear bearing sleeve, the tail end is connected with the sliding rheostat (11) through the telescopic rod clamp (12), and the sliding rheostat is fixed on the support plate (16); the permanent magnet (20) is fixed between the two telescopic rods through a linear bearing sleeve, maintaining a certain gap with the electromagnet; the spring washer (22) is connected between the two telescopic rods (18) and the permanent magnet (20), realizing synchronous movement in the Z-axis direction; a variable cross-section complex inner surface workpiece clamping part; the variable cross-section complex inner surface workpiece clamping part can achieve high rotating speed and prevent the workpiece from moving during rotation, improving the stability of the grinding process.

2. The polishing apparatus according to claim 1, wherein: The servo motor power part is used to provide power for the X-axis ball screw sliding table (2) and the Y-axis ball screw sliding table (6) and realize precise feeding; the servo motor power part comprises an X-axis servo motor, a Y-axis servo motor, an encoder, a controller and a driver.

3. The abrading device of claim 1, wherein: The two-axis positioning device part comprises a device bottom plate (1), an X-axis ball screw sliding table (2), an X-axis sliding block (3), a Y-axis L-shaped support plate (4), a Y-axis ball screw sliding table (6) and a Y-axis sliding block (7).

4. The abrading device of claim 1, wherein: The variable cross-section complex inner surface workpiece clamping part comprises a motor, a four-jaw chuck, a baffle and a retractable ejector pin; the four-jaw chuck clamps the flange of the workpiece to be processed on one side, and the baffle is installed on the other side and is tightly pressed by the retractable ejector pin.

5. A magnetic abrasive finishing method of the adaptive magnetic gap variable cross-section complex inner surface magnetic abrasive finishing device according to any one of claims 1 to 4, characterized by: It comprises the following steps: 1) a proper amount of magnetic abrasive and grinding liquid is loaded in the variable cross-section complex inner surface pipe, and the variable cross-section complex inner surface pipe is clamped in the workpiece clamping part; 2) Adjust the servo motor (5) of two-axis positioning device, so that the magnetic pole head of permanent magnet (20) on adaptive magnetic gap control part reaches the appropriate processing position; 3) Adjust the magnetic field intensity of electromagnet (14) by adjusting the current intensity, so that the magnetic pole head of permanent magnet (20) and the workpiece with complex inner surface of variable cross-section have appropriate processing gap; 4) First, start and adjust the X-axis servo motor, so that the telescopic rod tightly presses the outer surface of the pipe, and the tool setting is completed. Then adjust the Y-axis servo motor, so that the adaptive magnetic gap control part moves horizontally within the appropriate range. Finally, start the DC motor of the clamp part, so that the pipe rotates at a high speed; 5) Under the action of compound motion, the magnetic abrasive rolls, collides and scratches constantly, realizing the grinding processing of the inner surface of the workpiece. With the Y-axis direction feed of permanent magnet (20), as the cross-section of the workpiece becomes smaller, the excitation gap between the permanent magnet and the workpiece tends to increase, the telescopic rod (18) displaces downward, the resistance of the sliding rheostat (11) is reduced through the telescopic rod tail clamping sleeve, the current intensity of electromagnet (14) increases, thereby generating stronger magnetic field force acting on the permanent magnet, so that the telescopic rod and the workpiece are kept in the state of tight pressing, realizing the self-adaptive control of excitation gap in the process of magnetic force grinding processing of the pipe with complex inner surface of variable cross-section; 6) After processing, cut off the power supply, take down the pipe and carry out post-processing.

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