JP5682842B2 - Polishing equipment - Google Patents

Description

  The present invention relates to a polishing apparatus for performing EEM processing.

  Conventionally, it has been sufficient to obtain submicron-order accuracy in polishing processes that require finished surface roughness accuracy. However, recently, the accuracy of surface roughness on the order of several tens of nanometers or less, particularly atomic order. Until now comes to be required. As a processing method capable of obtaining a surface roughness of several tens of nm or less (or atomic order), for example, there is an EEM processing (Elastic Emission Machining) method. In this EEM processing method, a liquid containing abrasive grains is caused to flow between an object to be polished disposed in the liquid and a polishing member, and the abrasive grains collide with the surface (surface to be polished) of the object to be polished. This is a method of polishing the surface (surface to be polished) of the object to be polished with high accuracy (see, for example, Patent Document 1).

Japanese Patent Publication No. 2-25745

  However, in such a polishing method, since the polishing member does not come into contact with the object to be polished, damage due to polishing is extremely small, but the polishing rate becomes low, so there is a measure for increasing the polishing rate. It was sought after.

  The present invention has been made in view of such problems, and an object thereof is to provide a polishing apparatus having an increased polishing rate.

In order to achieve such an object, a polishing apparatus according to the present invention contains a polishing object having a surface to be polished, and stores a liquid containing abrasive grains for polishing the surface to be polished; The polishing member is rotated with the polishing member disposed in the liquid spaced apart from the surface to be polished of the object to be polished and the polishing member and the surface to be polished being spaced from each other. and a rotation mechanism for the abrasive member, a base portion outer peripheral surface is rotatably coupled to the said rotary mechanism about its rotational symmetry axis and is formed in a cylindrical shape, the outer peripheral surface of the base portion A plurality of screw tooth-shaped convex portions formed at intervals along the circumferential direction, and formed into a screw gear shape, and the screw tooth-shaped convex portions are rotated by the rotating mechanism to form the screw tooth-shaped convex portions. The abrasive grains are given a flow by scraping the liquid. Wherein being configured to abut on the polished surface, together with the protrusions, respectively, to protrude radially outward of the base portion to the outer peripheral surface, the axis of rotational symmetry in the outer circumferential plane It has a spiral shape formed in a linear shape which Ru extending in a direction inclined with respect.
In the polishing apparatus, preferably, the spiral shape of the convex portion of the polishing member is such that the polishing pressure applied to the surface to be ground is equal over the outer peripheral surface.
More preferably, the spiral shape of the convex portion of the polishing member is such that the tip region of the convex portion is equal over the outer peripheral surface in a cross section of the outer peripheral surface along the radial direction of the rotational symmetry axis. It has a shape like this.

  According to the present invention, the polishing rate can be increased.

1 is a schematic view of a polishing apparatus according to the present invention. It is an enlarged view which shows the vicinity of the polishing member. It is sectional drawing of an abrasive member. It is sectional drawing which shows the 1st modification of an abrasive member. It is a side view which shows the 2nd modification of an abrasive member.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. A schematic configuration of a polishing apparatus 1 to which the present invention is applied is shown in FIG. The polishing apparatus 1 includes an XY stage 20, a container 21 supported by the XY stage 20, a holding member 26 that is accommodated in the container 21 and holds an object to be polished (for example, a glass plate or a lens) 10, and XY A rotation holding mechanism 30 provided to face the stage 20, a polishing tool 40 rotatably held by the rotation holding mechanism 30, a lifting mechanism 50 that moves the polishing tool 40 up and down together with the rotation holding mechanism 30, and a polishing apparatus 1 mainly includes a control unit 60 that controls the operation of 1 and a housing unit 65 to which the XY stage 20, the lifting mechanism 50, the control unit 60, and the like are attached.

  The XY stage 20 supports the container 21 so as to be movable in a substantially horizontal plane (that is, in the front-rear and left-right directions) using a servo motor, a ball screw, or the like (not shown). Thereby, the to-be-polished object 10 accommodated in the container 21 together with the holding member 26 can be moved relative to the polishing tool 40 in a substantially horizontal plane (that is, in the front-rear and left-right directions).

  The container 21 is formed in a box shape having an opening at the top, and a polishing liquid 22 is stored therein. This polishing liquid 22 is a suspension in which fine polishing abrasive grains 23 (see FIG. 2) for polishing the workpiece 10 are mixed in water, and is a diaphragm connected to the container 21 via a conduit 24. The polishing liquid 22 is circulated across the container 21 and the pipe line 24 by the pump 25. The polishing liquid 22 stored in the container 21 is maintained at a predetermined temperature by a heat retention device (not shown). The holding member 26 is installed at the bottom of the container 21 in which the polishing liquid 22 is stored, and holds the object 10 to be polished while being positioned in the polishing liquid 22. That is, the workpiece 10 is accommodated in the container 21 in which the polishing liquid 22 is stored together with the holding member 26.

  The rotation holding mechanism 30 includes a head main body 31 and a rotary head portion 32 that is rotatably attached to the head main body 31. The head body 31 incorporates a bearing mechanism (not shown) and the like, and a rotary head portion 32 is rotatably attached. The rotary head unit 32 holds the polishing tool 40 in a detachable manner, whereby the polishing tool 40 is rotatably held by the rotation holding mechanism 30. In addition, a servo motor 33 is attached to the head main body 31, and the servo motor 33 rotationally drives the polishing tool 40 held by the rotary head portion 32 together with the rotary head portion 32.

  The polishing tool 40 includes a rod-shaped member 41 and a polishing member 45. The rod-shaped member 41 is formed so as to extend in a rod shape, and the polishing member 45 is attached to the distal end portion, and the proximal end side is connected and held to the rotary head portion 32. Therefore, the polishing tool 40 is held by the rotation holding mechanism 30 so as to be rotatable about the central axis extending in the longitudinal direction of the rod-shaped member 41, and the object to be polished 10 is rotated by the polishing member 45 that rotates at the tip portion of the rod-shaped member 41. Polishing is performed.

  The polishing member 45 is formed into a gear type (spur gear type) using, for example, a hard material such as stainless steel, ceramics, glass, or hard resin, and is attached to the distal end portion of the rod-like member 41 by adhesion or the like. That is, as shown in FIGS. 2 and 3, the polishing member 45 includes a base 46 formed in a disk shape and a plurality of tooth-shaped protrusions 47 (for example, heights) formed on the outer periphery of the base 46. Is 0.1 mm to 1 mm). The center of the base 46 is coupled to the tip of the rod-shaped member 41, and the rotation holding mechanism 30 is coupled to the rod-shaped member 41 so that the base 46 can rotate around the disk-shaped rotation target axis. Composed. As shown in FIG. 2, the plurality of convex portions 47 formed on the outer peripheral portion of the base portion 46 rotate together with the base portion 46 and scrape the polishing liquid 22, thereby polishing the polishing member 45 and the surface to be polished of the workpiece 10. A flow is given to the polishing liquid 22 located between the two.

  Further, as shown in FIG. 3, the tip of the convex portion 47 is formed in a circular arc shape (as viewed from the outer peripheral tangent direction of the base portion 46) so that a narrow range on the surface 11 to be polished can be polished. Yes. As shown in FIG. 4, a convex portion 147 having a flat cross-section at the tip may be formed on the outer peripheral portion of the base portion 146 of the polishing member 145 formed in a gear shape. Further, as the material of the polishing member 45, a material obtained by applying a wear-resistant coating made of a resin (for example, Vespel) to a stainless material may be used.

  The lifting mechanism 50 shown in FIG. 1 mainly includes a slide plate 51, a guide shaft 52 to which the slide plate 51 is attached, and a pneumatic cylinder 53 that drives the slide plate 51. The slide plate 51 is disposed above the XY stage 20 in the housing 65 and is attached so that the rotation holding mechanism 30 faces the XY stage 20. The slide plate 51 to which the rotation holding mechanism 30 is attached is attached to the left and right guide shafts 52, 52 fixed to the housing portion 65 so as to be slidable in the vertical direction, and rotates together with the slide plate 51. The holding mechanism 30 is slidable in the vertical direction (that is, can be moved up and down). The left and right guide shafts 52, 52 are each formed in a bar shape extending vertically, and are fixedly attached to the housing portion 65 so as to be parallel to each other.

  The slide plate 51 to which the rotation holding mechanism 30 is attached is gravity compensated by a balance weight (not shown) and left and right wires 54 and 54. That is, one end side of each wire 54 is connected to the slide plate 51, and the other end side is wound around the guide roller 55 and connected to a balance weight (not shown) on the back side. The guide roller 55 is rotatably attached to a bracket 66 fixed to the upper part of the housing portion 65.

  The rod portion of the pneumatic cylinder 53 is connected to the slide plate 51, and the slide plate 51 is moved up and down (sliding up and down) using air pressure. Accordingly, the polishing member 45 of the polishing tool 40 can be moved up and down by the pneumatic cylinder 53 via the slide plate 51 and the rotation holding mechanism 30.

  In order to polish the workpiece 10 by the EEM processing (Elastic Emission Machining) method using the polishing apparatus 1 configured as described above, first, the polishing liquid 22 is removed from the workpiece 10 by a transport device (not shown). The object to be polished 10 is transported into the stored container 21 and held in the polishing liquid 22 by the holding member 26. When the object to be polished 10 is conveyed into the container 21, the XY stage 20 is operated by the operation control of the control unit 60 to position the object to be polished 10 (container 21) at a predetermined polishing position. When the object to be polished 10 is positioned at the polishing position, the polishing member 45 of the polishing tool 40 is lowered from the predetermined retraction position into the container 21 by the pneumatic cylinder 53 by the operation control of the control unit 60. At this time, the operation of the pneumatic cylinder 53 is controlled so that the polishing member 45 is held in the polishing liquid 22 at a position close to the surface to be polished 11 of the object to be polished 10.

  When the polishing member 45 is lowered into the container 21, the polishing tool 40 is rotated at a predetermined rotation speed (for example, several hundred to several thousand rpm) by the servo motor 33 by the operation control of the control unit 60. The surface 11 to be polished is polished. At this time, as shown in FIG. 2, the convex portion 47 of the polishing member 45 rotates to scrape the polishing liquid 22, thereby causing a flow in the polishing liquid 22 positioned between the polishing member 45 and the surface 11 to be polished. The flow of the polishing liquid 22 comes into contact with the surface 11 to be polished. When the polishing liquid 22 comes into contact with the surface 11 to be polished, the abrasive grains 23 contained in the polishing liquid 22 collide with the surface 11 to be polished, whereby the surface 11 to be polished is polished.

  Thus, according to the polishing apparatus 1 of the present embodiment, the polishing liquid positioned between the polishing member 45 and the surface 11 to be polished is obtained by rotating the convex portion 47 of the polishing member 45 and scraping the polishing liquid 22. Since the flow is generated in 22, the flow rate of the polishing liquid 22 is improved and the number of polishing abrasive grains 23 that collide with the surface 11 to be polished is increased, so that the polishing rate (polishing amount per unit time) can be increased. become.

  Further, by forming the polishing member 45 in a gear shape, it is possible to form the convex portion 47 that scrapes the polishing liquid 22 with a simple configuration.

  In the above-described embodiment, the polishing member 45 is formed in a spur gear type, but is not limited thereto. For example, as shown in FIG. 5, the polishing member 245 has a screw gear (having a base portion 246 formed in a columnar shape and a plurality of tooth-shaped convex portions 247 formed in a spiral shape on the outer peripheral portion of the base portion 246. It may be formed in a screw gear) mold. Further, the shape of the polishing member is not limited to a gear type (disk shape or columnar shape), and for example, a tooth-shaped convex portion may be formed on a spherical base portion. A net-like convex portion may be formed.

DESCRIPTION OF SYMBOLS 1 Polishing apparatus 10 To-be-polished object 11 To-be-polished surface 21 Container 22 Polishing liquid 23 Polishing abrasive grain 26 Holding member 30 Rotation holding mechanism 32 Rotating head part 40 Polishing tool 41 Rod-shaped member 45 Polishing member 46 Base 47 Convex part 145 Polishing member (1st 1)
146 Base part 147 Convex part 245 Polishing member (2nd modification)
246 Base 247 Convex

Claims (3)

A container for storing an object to be polished having a surface to be polished, and storing a liquid containing abrasive grains for polishing the surface to be polished;
A polishing member disposed in the liquid at an interval from the surface to be polished of the object to be polished;
A rotation mechanism for rotating the polishing member with a gap between the polishing member and the surface to be polished;
The abrasive member, contact a base portion outer peripheral surface is rotatably coupled to the said rotary mechanism about its rotational symmetry axis and is formed into a cylindrical shape, the intervals along the circumferential direction on the outer peripheral surface of the base portion A plurality of screw-tooth-shaped protrusions formed into a screw gear shape and rotated by the rotating mechanism so that the screw-tooth-shaped protrusions scrape the liquid into the liquid. It is configured to apply a flow to bring the abrasive grains into contact with the surface to be polished.
The convex portions, respectively, with protruding radially outward of the base portion to the outer circumferential surface, formed in a linear shape Ru extending in a direction inclined with respect to the axis of rotational symmetry in the outer circumferential plane Polishing apparatus characterized by having a spiral shape .   2. The polishing apparatus according to claim 1, wherein the spiral shape of the convex portion of the polishing member is such that a polishing pressure applied to the surface to be polished is equal over the outer peripheral surface. .   The spiral shape of the convex portion of the polishing member is such that the region of the tip of the convex portion is equal across the outer peripheral surface in the cross section of the outer peripheral surface along the radial direction of the rotational symmetry axis. The polishing apparatus according to claim 1, wherein the polishing apparatus is configured.

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