JP5822906B2 - Polishing head - Google Patents

Description

  The present invention relates to a polishing head, and more particularly to a polishing head for holding a workpiece such as a mold by holding it with a spindle chuck of a machining center or a milling machine.

  For molds, such as molds for molding lenses and mirrors, molds for molding plastic parts, etc., to large molds for manufacturing automobile parts, the surface is smoothed to a mirror surface. There are many things that need to be done. And most of them are not simply flat shapes but complex shapes that change three-dimensionally. In such a case, in the prior art, after processing into a predetermined shape by cutting or grinding, it is usually polished carefully by hand, and the surface is polished to the required surface roughness to obtain a mirror surface. Was done.

  Furthermore, in a mold that requires high wear resistance, such as a mold that presses metal, the mold material is a hardened and hardened steel material that is carefully polished until it becomes a mirror surface manually. Therefore, it was very laborious and time consuming.

  The present applicant has filed as Japanese Patent Application No. 2013-008218 (Patent Document 1) a grinding apparatus and a grinding method for polishing such a mold that requires high wear resistance. However, this grinding apparatus and grinding method are suitable for polishing the bottom surface of a relatively flat mold, but when polishing a mold side wall having a deep concave surface and the side wall of which is nearly vertical. Found that is not necessarily optimal. For this reason, the polishing head of the present invention has been developed as a polishing head for polishing a side wall of a mold having a new deep concave surface and the side wall of which is nearly vertical.

Japanese Patent Application No. 2013-008218 JP 60-131106 A (refer to page 2-4, FIG. 2 and FIG. 4) Japanese Utility Model Publication No. 60-61112 (see page 6-8, FIG. 3 to FIG. 5) JP-A-6-31626 (refer to page 3-4, FIG. 2)

  The conventional grinding apparatus and grinding method described in Patent Document 1 is a polishing head for holding a workpiece such as a mold by holding it with a spindle chuck of a machining center or a milling machine. Although it is possible to grind the workpiece to a mirror surface efficiently and fully automatically, it is not always necessary to polish the side wall of a mold having a deep concave surface and the side wall of which is nearly vertical following the irregularities of the side wall. It was not optimal.

  That is, when polishing a side wall of a mold having a deep concave surface and the side wall of which is nearly vertical, it is necessary to effectively use the side surface of the grindstone to be polished. It is desirable that the center axis of the grindstone shaft that is gripped and rotated swings to cope with changes in the irregularities of the side walls, and is polished with an appropriate pressure to support excessive swinging.

  In the present invention, in order to polish the side wall of the mold having such a deep concave surface and the side wall of which is nearly vertical, following the unevenness of the side wall, a polishing head held by the spindle chuck and rotated is provided as an outer cylinder. And an inner shaft that is disposed at the center of the outer cylinder and grips the grindstone. The inner shaft is swingable with respect to the outer cylinder, and the swinging inner shaft is laterally moved with an appropriate pressure. It is configured to support, and the inner surface of the outer cylinder and the outer surface of the inner shaft are polygonal, and this polygon transmits rotation from the outer cylinder to the inner shaft and serves as a fulcrum for swinging the inner shaft. It was.

  Patent Document 2 includes a prime mover 1, a support metal 4 as a fulcrum for swinging the prime mover 1, and a plurality of elastic bodies 2 (spring mechanism in FIG. 2) or 27 (first The arrangement with the fluid pressure cylinder 28) of FIG. 4 is described. All of the mechanisms included in these configurations are mechanisms having appropriate elements, which must be large and expensive, and are very difficult to be incorporated directly into the polishing head. .

  As described above, a large number of motors having a prime mover have been filed as being suitable for a deburring device by a robot apparatus. However, polishing that is gripped and rotated by a spindle chuck of a machining center or a milling machine can be performed only by providing a prime mover. The head is too expensive to be adopted.

  Further, in Patent Document 3, as shown in FIGS. 3 to 5, an example in which rotation is transmitted from the drive shaft to the floating shaft and the floating shaft can be swung without having a prime mover. Is described. That is, in FIG. 3 and FIG. 4, between the ball groove 21 of the drive side rotation transmission plate 20 or the drive shaft 1 and the ball groove 28 of the driven side rotation transmission plate 27 or the spherical ball groove 34 of the spherical sliding bearing 24. A configuration is described in which the rotation of the drive shaft 1 is transmitted to the floating shaft 5 through a ball 30 and the floating shaft 5 that is a shaft for holding the grindstone by the spherical plain bearing 24 can be swung. Further, in FIG. 5, a ball 30 is incorporated between the ball groove 21 on the drive shaft 1 side and the spherical ball shaft 34 of the spherical plain bearing 24 fixed to the floating shaft 5 to swing the floating shaft 5. In addition, a configuration for transmitting rotation is described.

  However, this configuration has a fairly complicated structure, is inevitably large and expensive, and is difficult to incorporate into a polishing head. And since patent document 3 does not describe what stops rocking of the floating shaft with an appropriate pressure, also in this respect, the side wall of the mold having a deep concave surface and the side wall of which is nearly vertical, This is not suitable for the polishing head of the present invention which is intended to polish along the unevenness of the side wall.

  On the other hand, in Patent Document 4, the square shaft 2 is fixed to the output shaft 1a of the rotary drive source 1, the square tube 3 is fitted to the square shaft 2, and the square shaft 2 has a regular hexagonal cross-sectional shape. It is described that the inner shape of the cylinder 3 is a cross-sectional shape in which regular hexagons shifted by 30 degrees are overlapped. However, this configuration shows only the use of a hexagonal shaft and cylinder as a rotation transmission means, the shaft holding the grindstone cannot be swung, has a deep concave surface, It is not suitable for polishing the side wall of the mold whose side wall is almost vertical following the unevenness of the side wall.

  In the above description, polishing including the entire polishing of the mold has been described as polishing. However, the polishing operation is often described as polishing or grinding, and there is no clear distinction between polishing and polishing or grinding. Further, polishing with loose abrasive grains is called polishing or polishing, and polishing with a grindstone is sometimes called grinding, but this is also not fixed. Therefore, in this specification, the entire polishing of the mold (including polishing or grinding) is referred to as polishing.

(Object of invention)
The present invention solves the above-mentioned problems, and can polish the side wall of a mold having a deep concave surface and the side wall of which is nearly vertical, following the unevenness of the side wall, and is held by a spindle chuck of a machining center or a milling machine. It is another object of the present invention to provide an inexpensive polishing head that is capable of grinding to a mirror surface efficiently and fully automatically and that has a simple structure.

In order to achieve the above object, a polishing head according to the present invention is a polishing head that is gripped by a spindle chuck of a machining center or a milling machine and performs polishing processing, and an outer cylinder that is gripped by the spindle chuck and rotates, and the outer cylinder. An inner shaft disposed at the center of the cylinder and attachable to a polishing tool at the tip, the outer cylinder and the inner shaft formed in a polygonal hole formed in the outer cylinder and the inner shaft Connected by a polygonal shaft of the same size, the inner shaft is swingable in an arbitrary direction with respect to the center line of the polishing head, and is connected non-rotatably to each other. Between the inner shaft, an elastic ring that supports the inner shaft in the vicinity of the tip of the outer cylinder, and an inner shaft so as to stop the swinging of the inner shaft at an appropriate pressure and an excessive swing. Energize downward Wherein the Ne are disposed.

  Further, the polygonal shaft formed on the inner shaft has a surface formed in an arc shape having a large curvature radius along the center line of the polishing head.

  Furthermore, the polygonal hole and the polygonal axis are both regular hexagonal holes and axes.

  Since the polishing head of the present invention is configured as described above, the side wall of the mold having a deep concave surface and the side wall of which is nearly vertical can be polished in accordance with the unevenness of the side wall. It is possible to provide an inexpensive polishing head with a simple structure that can be held by the main spindle chuck and can be fully automated and ground to a mirror surface efficiently.

  At this time, if the polishing state of the concave bottom surface is not satisfactory, the polishing head described in Japanese Patent Application No. 2013-008218 (Patent Document 1) is replaced, and the polishing of the concave bottom surface is performed again. By doing so, the desired surface condition can be obtained.

  Since the inner shaft swings with respect to the outer cylinder, the inner shaft (grinding stone) tilts with respect to the spindle chuck of the machining center or milling machine, but the swinging angle is very small and the length of the grinding wheel is also long. Since it is short, it becomes almost negligible. If an elastic grindstone such as a rubber grindstone is used as the grindstone, the error can be completely ignored.

It is sectional drawing which shows one embodiment of the polishing head of this invention. It is A sectional drawing of FIG. It is B sectional drawing of FIG.

  Embodiments of the present invention will be described below with reference to the drawings showing examples. FIG. 1 is a cross-sectional view showing an embodiment of the polishing head of the present invention. 2 is a cross-sectional view of FIG. 1A, showing that the inner shaft and the outer cylinder are connected by a polygonal (hexagonal) shaft and a hole, and FIG. FIG. 3 is a cross-sectional view of FIG. 2 showing that the hexagonal shaft portion of the inner shaft is formed into an arc with a large curvature radius along the center line of the polishing head.

  A polishing head 1 according to the present invention is attached to a machining center or a spindle chuck (not shown) of a milling machine and performs polishing. As shown in FIG. 1, main members are an outer cylinder 2 and an outer cylinder 2. The inner shaft 3 is inserted into the central hollow portion, and a collet chuck portion 5 to which a polishing tool 4 such as a grindstone is attached is disposed at the tip of the inner shaft 3.

  The outer shape of the outer cylinder 2 is divided into an upper small-diameter portion 2a and a lower large-diameter portion 2b. The upper small-diameter portion 2a is gripped and rotated by a chuck (not shown) of a spindle of a machining center or a milling machine, Polishing is performed.

  A bolt 7 is fixed to the upper end of the inner shaft 3 via a washer 6 and is in contact with a step 2c of the outer cylinder 2 via a sleeve 8, and the inner shaft 3 is pulled out by a biasing force of a coil spring 13 described later. It has been prevented. At the position of the lower section A, as shown in FIG. 2, the inner surface 2d of the outer cylinder 2 and the outer surface 3a of the inner shaft 3 are both regular polygons (regular hexagons in FIG. 2) having the same dimensions. It is formed in the hole and shaft.

  In the cross section B perpendicular to the regular polygonal inner surface 2d and outer surface 3a and along the vertical direction in FIG. 1, the polygonal outer surface 3a of the inner shaft 3 has a middle height as shown in FIG. A circular arc having a large radius of curvature is formed along the center line of the polishing head 1. The inner surface 2d of the outer cylinder 2 and the central portion of the outer shape 3a of the inner shaft 3 are in contact with each other.

  Since the hole and shaft of the regular polygon (regular hexagon in FIG. 2) are configured in this way, the hole inside the regular cylinder (regular hexagon in FIG. 2) of the outer cylinder 2 (inner surface 2d) Since the outer surface 3a of the inner shaft 3 of the regular polygon (regular hexagon in FIG. 2) formed in the state is inserted, the outer cylinder 2 and the inner shaft 3 are mutually non-rotatable and the outer shaft 3 In the cylinder 2, the inner shaft 3 can swing around the middle portion of the outer shape 3 a as a fulcrum.

  The shape of the regular polygon is most preferably a regular hexagon as shown in FIG. 2 from the viewpoint of ease of processing, but it may be a regular pentagon or a regular square. In this embodiment, the polygonal surface 3a of the inner shaft 3 has a medium height, but the inner shaft 3 can also be provided by providing a slightly larger gap between the inner surface 2d of the outer tube 2 and the outer shape 3a of the inner shaft 3. Therefore, it is possible to oscillate even if the surface 3a does not necessarily have a medium height.

  Since the inner surface 2d of the outer tube 2 and the outer surface 3a of the inner shaft 3 are configured in this way, the outer tube 2 and the inner shaft 3 are not rotatable relative to each other and are movable in the axial direction, and The center portion can be swung around a point where the inner surface 2d of the outer cylinder 2 and the outer shape 3a of the inner shaft 3 are in contact with each other.

  An elastic ring 12 sandwiched between a sleeve 9 and a spacer 10 and fixed to the outer cylinder 2 by a stop ring 11 is disposed at a substantially central portion of the outer cylinder 2. The elastic ring 12 supports the swinging of the inner shaft at an appropriate pressure so as to stop excessive swinging. By forming it in a ring shape, it is possible to always support the inner shaft 3 with a constant pressure regardless of which direction the inner shaft 3 swings during polishing. The elastic ring 12 only needs to generate a predetermined pressure. For example, a known product such as an O-ring can be used. Incidentally, in the embodiment of the present invention, a seal provided with a plastic cover 12b on the outer periphery of a metal coil spring 12a is used.

  It is desirable that the sleeve 9 and the spacer 10 have a slight gap inside or outside so as not to prevent the elastic ring 12 from being deformed by the swinging of the central shaft 2 and moving in the lateral direction. A slight gap is provided between the outer diameter of the sleeve 9 and the inner diameter of the outer cylinder 2 and between the inner diameter of the spacer 10 and the outer diameter of the inner shaft 3.

  For the same reason, it is desirable that the sleeve 9, the spacer 10 and the elastic ring 12 have little friction with each other. For this reason, it is desirable that the sleeve 9 and the spacer 10 be made of a material having a low friction coefficient such as Teflon (registered trademark), or the cover of the elastic ring 12 is made of Teflon (registered trademark), and the sleeve 9 and the spacer 10 are formed. Is preferably a metal ring.

  A coil spring 13 that urges the inner shaft 3 downward is provided below the elastic ring 12. The coil spring 13 is used to press the polishing tool 4 at the tip against a workpiece such as a die with a predetermined pressure, and the force for biasing the inner shaft 3 downward is applied to the upper end of the polishing head 1. It is received by the provided sleeve 8.

  The coil spring 13 is supported by a step 2e of the outer cylinder 2 via a spring receiver 14, and a gap between the lower end of the spring receiver 14 and the step 3b of the inner shaft 3 causes the polishing tool 4 to be processed such as a mold. When processing is performed by pressing against an object, the amount of relief becomes such that the inner shaft 3 is pushed upward when an excessive force is applied.

  An elastic ring 15 is provided again at the tip of the outer cylinder 2. The elastic ring 15 is different in diameter from the elastic ring 12 described above, and is used for the same purpose and has the same function and effect. Therefore, detailed description is omitted here.

  Here, the provision of the two elastic rings 12 and 15 has no particular meaning. When only the supporting force of the elastic ring 15 on the front end side is sufficient, the central elastic ring 12 can be omitted. However, omitting the elastic ring 15 on the distal end side is not preferable from the viewpoint of dust prevention.

  A dust cap 16 is disposed at the upper end of the outer cylinder 2. The dust cap 16 is sufficient to be used for ordinary dust protection, and a dust cap made of rubber or soft plastic is preferable.

  A collet chuck portion 5 is provided on the inner shaft 3 at the tip of the polishing head 1. As described above, the collet chuck portion 5 holds the polishing tool 4 and includes a collet chuck 17 and a cap nut 18, and the shank 4 a and the collet chuck 17 of the polishing tool 4 bite and come off. In order to prevent disappearance, a protrusion 17 a is provided at the tip of the collet chuck 17.

  Since the polishing head 1 of the present invention is configured as described above, the polishing head 1 has a deep concave surface in a polishing apparatus which is held by a spindle chuck of a machining center or a milling machine and is ground to a mirror surface efficiently and fully automatically. The side wall of the mold whose side wall is nearly vertical can be polished following the irregularities of the side wall. At this time, if the polishing state of the relatively flat portion of the concave surface is not satisfactory, the polishing head described in Japanese Patent Application No. 2013-008218 (Patent Document 1) is replaced with a relatively flat concave surface. Polishing may be performed.

1: Polishing head 2: Outer cylinder 2a: Small diameter portion 2b: Large diameter portion 2c: Step 2d: Inner surface 2e: Step 3: Inner shaft 3a: Outer surface 3b: Step 4: Polishing tool 4a: Shank 5: Collet chuck portion 6: Washer 7: Bolt 8: Sleeve 9: Sleeve 10: Spacer 11: Stop ring 12: Elastic ring 12a: Coil spring 12b: Cover 13: Coil spring 14: Spring support 15: Elastic ring 16: Dust-proof cap 17: Collet chuck 18: Cap nut

Claims (3)

A polishing head that is gripped by a spindle chuck of a machining center or a milling machine and polished.
An outer cylinder gripped and rotated by the spindle chuck ;
An inner shaft disposed at the center of the outer cylinder and capable of attaching a polishing tool to the tip ;
The outer cylinder and the inner shaft are connected by a polygonal hole formed in the outer cylinder and a polygonal shaft of the same dimension formed in the inner shaft, and the center line of the polishing head is The inner shafts can swing in any direction and are connected so as not to rotate with each other .
Between the outer cylinder and the inner shaft, an elastic ring that supports the inner shaft in the vicinity of the distal end of the outer cylinder so as to stop the excessive oscillation of the inner shaft with an appropriate pressure. And a spring for urging the inner shaft downward. The axis of polygon formed in said shaft, that surface, polishing head according to claim 1, characterized in that formed on the large radius of curvature of the circular arc shape along the center line of the polishing head.   3. The polishing head according to claim 1, wherein each of the polygonal hole and the polygonal axis is a regular hexagonal hole and axis.

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