CONTROLLABLE MAGNETIC FIELD-ASSISTED FINISHING APPARATUS FOR INNER SURFACE AND METHOD

Abstract

A controllable magnetic field-assisted finishing apparatus for an inner surface and a finishing method are provided. The apparatus includes a housing, ball screw mechanisms, a workpiece, a centering clamp, a connecting plate, a magnetic field generating device, a chuck clamp, a precise displacement platform and a base. The magnetic field generating device includes electromagnetic coils, coil connecting plates, a magnetic yoke, nuts, springs and bolts. The magnetic field generating device dynamically adjusts a distance from the magnetic yoke to the outer surface of the workpiece through the springs. The movement tracks of the magnetic finishing medium are controlled by the formed rotation of the magnetic field, the finishing action force dynamic-adjustment, the optimization of the machining form of the magnetic finishing medium in collaboration with the rotation of the chuck clamp and the feed movement of the precise displacement platform.

Claims

1. A finishing method, the method being carried out by a controllable magnetic field-assisted finishing apparatus for an inner surface, the apparatus comprising: a housing; ball screw mechanisms; a workpiece; a centering clamp; a connecting plate; a magnetic field generating device; a chuck clamp; a precise displacement platform; and a base; wherein the magnetic field generating device comprises: electromagnetic coils; coil connecting plates; a magnetic yoke; nuts; springs and bolts; wherein: the magnetic field generating device is fixed through the connecting plate on one of the ball screw mechanisms that is located on a top of the housing; the magnetic yoke with a minute structure is fixedly connected to an end of each of the electromagnetic coils; the electromagnetic coils are fixedly connected to the coil connecting plates in one-to-one correspondence through corresponding ones of the bolts that are each mounted with the springs and the nuts; an end of the workpiece is fixed through the centering clamp; another end of the workpiece is clamped on the chuck clamp; and the centering clamp and the chuck clamp are fixedly connected to the precise displacement platform; wherein the method comprises: placing a magnetic finishing medium in a region, which is to be processed, of the inner surface of the workpiece; fixing the workpiece through the centering clamp and the chuck clamp, to complete localization and clamping; and tightly attaching the magnetic field generating device to an outer surface of the workpiece through the springs; driving the magnetic field generating device by the one of the ball screw mechanisms to move to the region where the magnetic finishing medium is placed; operating the electromagnetic coils at a predetermined sequence, a predetermined current value and a predetermined frequency value, to generate a rotating magnetic field; and applying a finishing action force formed by the rotating magnetic field to the magnetic finishing medium; applying a drive signal to the chuck clamp and the precise displacement platform; performing a workpiece rotation; and making the precise displacement platform to perform a feed movement; implementing a relative movement between the magnetic finishing medium and the inner surface of the workpiece by cooperating the rotating magnetic field generated by the electromagnetic coils with the workpiece rotation and the feed movement of the precise displacement platform; changing in real time an energizing sequence as well as the predetermined current value and the predetermined frequency value of the electromagnetic coils based on a machining quality requirement on the inner surface of the workpiece and a roughness change during machining, to form another rotating magnetic field; dynamically adjusting another finishing action force applied to the magnetic finishing medium and optimizing a machining form of the magnetic finishing medium, in cooperation with a movement of the chuck clamp and a movement of the precise displacement platform, to make the magnetic finishing medium to form a plurality of movement tracks; and powering off the electromagnetic coils; and removing the magnetic finishing medium attached to the inner surface of the workpiece.

2. A controllable magnetic field-assisted finishing apparatus for an inner surface, wherein the apparatus comprises: a housing; ball screw mechanisms; a workpiece; a centering clamp; a connecting plate; a magnetic field generating device; a chuck clamp; a precise displacement platform; and a base; wherein the magnetic field generating device comprises: electromagnetic coils; coil connecting plates; a magnetic yoke; nuts, springs and bolts; wherein: the magnetic field generating device is fixed through the connecting plate on one of the ball screw mechanisms that is located on a top of the housing; the magnetic yoke with a minute structure is fixedly connected to an end of each of the electromagnetic coils; the electromagnetic coils are fixedly connected to the coil connecting plates in one-to-one correspondence through corresponding ones of the bolts that are each mounted with the springs and the nuts; an end of the workpiece is fixed through the centering clamp; another end of the workpiece is clamped on the chuck clamp; and the centering clamp and the chuck clamp are fixedly connected to the precise displacement platform.

3. The controllable magnetic field-assisted finishing apparatus for the inner surface according to claim 2, wherein the magnetic field generating device dynamically adjusts a distance from the magnetic yoke to an outer surface of the workpiece through the springs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a schematic view showing an overall structure of a controllable magnetic field-assisted finishing apparatus for an inner surface according to an embodiment of the present disclosure.

[0009] FIG. 2 is a schematic structural view of a magnetic field generating device of a controllable magnetic field-assisted finishing apparatus for an inner surface—according to an embodiment of the present disclosure.

[0010] FIGS. 3(a)-3(d) are schematic views of a rotating magnetic field generated by energizing electromagnetic coils at different sequences, where the electromagnetic coils are included in a controllable magnetic field-assisted finishing apparatus for an inner surface-according to an embodiment of the present disclosure.

[0011] FIG. 4 is a schematic view of movement tracks of a magnetic finishing medium of a controllable magnetic field-assisted finishing apparatus for an inner surface—according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Example 1

[0012] The apparatus is described in combination with FIG. 1 and FIG. 2, which includes a housing 1-1, ball screw mechanisms 1-2, a workpiece 1-3, a centering clamp 1-4, a connecting plate 1-5, a magnetic field generating device 1-6, a chuck clamp 1-7, a precise displacement platform 1-8 and a base 1-9. The magnetic field generating device includes electromagnetic coils 2-1, coil connecting plates 2-2, a magnetic yoke 2-3, nuts 2-4, springs 2-5 and bolts 2-6. The magnetic field generating device 1-6 is fixed, through the connecting plate 1-5, on the ball screw mechanism 1-2 placed on a top of the housing 1-1. The magnetic yoke 2-3 having a minute-structural feature is fixedly connected to an end of each of the electromagnetic coils 2-1. The electromagnetic coil 2-1 is fixedly connected to the coil connecting plate 2-2 through corresponding ones of the bolts 2-6 that are each provided with the springs 2-5 and the nuts 2-4. An end of the workpiece 1-3 is fixed through the centering clamp 1-4 and an other end of the workpiece is clamped on the chuck clamp 1-7. And the centering clamp 1-4 and the chuck clamp 1-7 are fixedly connected to the precise displacement platform 1-8.

Example 2

[0013] As shown in FIG. 1 and FIG. 2, the centering clamp 1-4 and the chuck clamp 1-7 are cooperatively used together with the magnetic field generating device 1-6, and thus workpieces 1-3 of different shapes may be clamped. The magnetic field generating device 1-6 dynamically adjusts a distance from the magnetic yoke 2-3 to the outer surface of the workpiece 1-3 through the springs 2-5, thereby shortening a distance that the magnetic flux intensity is transferred to the inner surface of the workpiece 1-3, reducing the loss of the magnetic flux intensity to the finishing region, and enhancing the finishing action force. Others are the same as Example 1.

Example 3

[0014] As shown in FIGS. 3(a)-3(d), different rotating magnetic fields are formed by changing an energizing sequence of the electromagnetic coils 2-1, thereby driving the magnetic finishing medium to rotate along the inner surface of the workpiece 1-3, and further performing the localized finishing on different machining regions. When the machining region is the whole inner surface of the workpiece 1-1, the energizing sequence may be AB-BC-CD-DĒ-EF-FĀ or ABC-BCD-CDE-DĒF-EFA-FĀB, where AB represents that a positive current is charged to electromagnetic coil A to form an N pole and a negative current is charged to electromagnetic coil B to form an S pole; and the energizing of other electromagnetic coils is similar to the electromagnetic coils A and B. Rotating magnetic fields that are generated are respectively as shown in FIG. 3(a) and FIG. 3(b). When the machining region is a local part of the inner surface of the workpiece 1-1, the energizing sequence may be AB-BĀ or ABC-ĀBC, where AB represents that a positive current is charged to electromagnetic coil A to form an N pole and a negative current is charged to the electromagnetic coil B to form an S pole; and the energizing of other electromagnetic coils is similar to the electromagnetic coils A and B. The rotating magnetic fields that are generated are respectively as shown in FIG. 3(c) and FIG. 3(d). Current values and frequency values are changed in real time based on a machining quality requirement on the inner surface of the workpiece 1-3 and a roughness change during machining, to dynamically adjust a finishing action force and optimize a machining form of the magnetic finishing medium, thereby achieving the finishing that is the high quality, the high efficiency and the intelligent. Others are the same as Example 1 or Example 2.

Example 4

[0015] As shown in FIG. 1, FIG. 2, FIGS. 3(a)-3(d), and FIG. 4, after a drive signal is applied to the chuck clamp 1-7 and the precise displacement platform 1-8, the workpiece 1-3 rotates and the relative magnetic field generating device 1-6 performs a feed movement, in cooperation with the rotating magnetic field generated by the electromagnetic coils 2-1, the magnetic finishing medium forms multiple movement tracks for the selective localized finishing. After the drive signal is applied to the chuck clamp 1-7 and the precise displacement platform 1-8, the energizing sequence of the electromagnetic coils 2-1 is AB-BC-CD-DĒ-EF-FĀ or ABC-BCD-CDE-DĒF-EFA-FĀB, and movement tracks 4-1, 4-2 formed by the magnetic finishing medium cover the whole inner surface of the workpiece 1-3, so as to implement the finishing on the whole inner surface of the workpiece 1-3. After the drive signal is applied to the precise displacement platform 1-8, the energizing sequence of the electromagnetic coils 2-1 is AB-BĀ or ABC-ĀBC, and movement tracks 4-3, 4-4 formed by the magnetic finishing medium cover the local part of the inner surface of the workpiece 1-3, so as to implement the localized finishing on the inner surface of the workpiece 1-3. Others are the same as Example 1, 2 or 3.

Example 5

[0016] As shown in FIG. 1, FIG. 2, FIGS. 3(a)-3(d), and FIG. 4, the electromagnetic coils 2-1 are powered off upon the completion of the finishing, so that the magnetic flux density in the finishing region and the finishing action force on the inner surface disappear at the same time, and the magnetic finishing medium attached to the inner surface of the workpiece 1-3 is easily removed or replaced. Others are the same as Example 1, 2, 3 or 4.

Example 6

[0017] As shown in FIG. 1, FIG. 2, FIG. 3 and FIG. 4, the finishing steps that are carried out by the apparatus described in any one of Example 1, 2, 3, 4 or 5 are as follows.

[0018] In step (1), a magnetic finishing medium is placed in a region, which is to be processed, of an inner surface of the workpiece 1-3.

[0019] In step (2), the workpiece 1-3 is fixed through the centering clamp 1-4 and the chuck clamp 1-7 to complete localization and clamping; and the magnetic field generating device 1-6 is tightly attached to an outer surface of the workpiece 1-3 through the springs 2-5.

[0020] In step (3), the magnetic field generating device 1-6 is driven by the ball screw mechanism (1-2) to move to the region where the magnetic finishing medium is placed.

[0021] In step (4), the electromagnetic coils 2-1 are operated at a predetermined sequence, a predetermined current value and a predetermined frequency value to generate a rotating magnetic field; and a finishing action force formed by the rotating magnetic field is applied to the magnetic finishing medium.

[0022] In step (5), a drive signal is applied to the chuck clamp 1-7 and the precise displacement platform 1-8; a rotation of the workpiece 1-3 is started; and the precise displacement platform 1-8 is made to perform a feed movement.

[0023] In step (6), a relative movement is implemented between the magnetic finishing medium and the inner surface of the workpiece 1-3 by cooperating the rotating magnetic field generated by the electromagnetic coils 2-1 with the rotation of the workpiece 1-3 and the feed movement of the precise displacement platform 1-8, for a high-efficiency and high-quality finishing.

[0024] In step (7), the energizing sequence as well as the predetermined current value and the predetermined frequency value of the electromagnetic coils 2-1 are changed in real time based on a machining quality requirement on the inner surface of the workpiece 1-3 and a roughness change during machining, to form another rotating magnetic field; another finishing action force applied to the magnetic finishing medium is dynamically adjusted and a machining form of the magnetic finishing medium is optimized, in cooperation with a movement of the chuck clamp 1-7 and a movement of the precise displacement platform 1-8 to make the magnetic finishing medium to form a plurality of movement tracks, so as to implement a localized and intelligent finishing on the inner surface of the workpiece 1-3.

[0025] In step (8), the electromagnetic coil 2-1 is powered off upon completing the finishing, so that a magnetic flux density in a finishing region and the finishing action force on the inner surface disappear at the same time; and the magnetic finishing medium attached to the inner surface of the workpiece 1-3 is removed.