JPH0525815Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hand-held polishing device equipped with a cup-shaped polishing tool for polishing the surfaces of protrusions such as bolt heads and nuts.

[Prior art]

Generally, structures with exposed construction materials, such as bridges, need to be repainted at regular intervals to prevent corrosion, but in that case, surface rust and previous paint must be removed in advance. Must.
Traditionally, wire brushes and hand grinders have been used to remove rust and paint from protrusions such as the heads of high-tensile bolts and nuts in structures, but wire brushes are inefficient and Work with a hand grinder often risks damaging or deforming the substrate.

[Problem that the invention attempts to solve]

The present invention is based on the idea that conventional methods of polishing using wire brushing or hand grinders to remove rust and paint from the surfaces of protrusions such as bolt heads and nuts are inefficient and can easily damage the underlying surface. This problem is solved by providing a hand-held polishing device equipped with a cup-shaped polishing tool capable of polishing the surface of a protrusion efficiently and with a good finish.

[Means for solving problems]

The present invention, as a means to solve the above-mentioned problems, polishes the surface of a hexagonal workpiece having a predetermined thickness on a protruding part of a spindle that is protruded from a grasping part and driven to reciprocate. The cup-shaped polishing tool has one end fixedly fixed therein. The abrasive grains containing a magnetic substance are magnetically attracted, and the hexagonal shape is A structure is adopted that is set between the diagonal portion of the workpiece and the inner surface of the recess.

[Effect]

When the recess of the cup-shaped polishing tool is placed over a protrusion such as a bolt head or nut, the abrasive grains magnetically attracted to the inside of the recess fill the space between the recess and the protrusion. come into contact with a wide range of areas. In this state, by giving the polishing tool a reciprocating rotational motion and causing it to vibrate, the abrasive grains polish the surface of the protrusion while repeating minute relative movements within the recess.

〔Example〕

The hand-held polishing device of this embodiment includes a cup-shaped polishing tool 30 as shown in FIG.
0 is attached to a reciprocatingly rotatable spindle 6 protruding from the grip 2 and used for polishing protrusions 36 of bolt heads, nuts, etc.

First, a spindle 6 is rotatably supported perpendicularly to the motor shaft 3 via ball bearings 4 and 5 in the gripping portion 2 which incorporates the motor 1 as a drive source. By converting the rotation of 3 into a rocking motion and transmitting it, the spindle 6 can be rotated reciprocally through a relatively small predetermined angle.

That is, an arm 7 is provided in the middle of the spindle 6.
One end of the arm 7 is fixed by spline fitting, and the other end of the arm 7 is provided with a support ring 9 having a cylindrical surface 8 whose axis is parallel to the spindle 6 on the inner surface.
is formed by cutting out a part of the outer periphery located at the longitudinal end of the arm 7. A slider 10 is fitted into the support ring 9 so as to be able to rotate relative to the cylindrical surface 8 while slidingly contacting the same.
Incidentally, the displacement of the slider 10 in the axial direction with respect to the support ring 9 is restricted by a stopper such as a snap spring (not shown). On the other hand, an eccentric shaft 11 whose tip end is eccentric with respect to the coaxial shaft 3 is fixed to the motor shaft 3, and on the eccentric tip end of the eccentric shaft 11,
A ball bearing 12 having a relatively small external shape and functioning as a guide roller is rotatably positioned and supported by a pair of stop rings 13. The slider 10 has a spindle 6 that can slide on the outer circumferential surface of the ball bearing 12 and has a length that is at least twice the eccentricity E of the eccentric shaft 11, as shown in FIG.
A long hole 14 extending in the axial direction (vertical direction) is formed through the ball bearing 12, and the outer peripheral portion of the ball bearing 12 is loosely fitted into the long hole 14. When the eccentric shaft 11 is driven to rotate, the ball bearing 12, which rotates eccentrically in response, moves up and down relatively inside the elongated hole 14, so that the displacement component of the ball bearing 12 in the left and right direction is substantially reduced. is transmitted to the slider 10, and the arm 7 swings together with the spindle 6 about the axis of the spindle 6.

The spindle 6 protrudes from the lower end of the gripping part 2, and the protruding part is provided with a plurality of vertical divisions radially with respect to the center hole 15 concentric with the spindle 6, similar to a so-called drill chuck, so that the protruding part is provided with a plurality of vertical divisions radially with respect to the center hole 15 concentric with the spindle 6. A tightening operation ring 19 is formed with a plurality of supporting pieces 16 that can be bent in a cantilevered manner, and has an upwardly tapered surface 18 on the inner peripheral surface of the distal end that engages with a downwardly tapered surface 17 formed on the outer periphery of the distal end of the supporting piece 16. , a chuck portion 2 screwed into the outer periphery of the support piece 16;
form 0. The chuck portion 20 has its center hole 1
The rod 31 of the cup-shaped polishing tool 30 inserted into the
By rotating the tightening operation ring 19 in the tightening direction, the cup-shaped polishing tool 30 is clamped and fixed by the plurality of support pieces 16.
Detachably attaches and fixes to.

The cup-shaped polishing tool 30 is made by fixing a permanent magnet 33 such as an alnico magnet or a ferrite magnet to the inner surface of a cylinder 32 made of metal or highly rigid resin, which has an opening at one end and a closed end at the other end. A recess 34 having an adsorption force is formed, and abrasive grains 35, which are made of a granular magnetic material coated with an abrasive and have a relatively small particle size, are magnetically attracted to the surface of the recess 34, and the cylindrical body 3
A rod 31 is erected at the center of the outer end surface of the closed end of the rod 2.

The internal dimensions of the recess 34 are such that when the cup-shaped polishing tool 30 is placed over a protrusion 36 that is a hexagonal workpiece having a predetermined thickness such as a bolt head or a nut to be polished, the recess 34 is Permanent magnet 33
The protrusion 36 is arranged so that the abrasive grains 35 magnetically attracted to the surface of the protrusion 36 fill the space between the surface and the protrusion 36.
It may be set so that it can come into contact with a wide range of the surface. Therefore, the internal dimensions of the recess 34 are determined by the outer diameter of the protrusion 36 to be polished by the cup-shaped polishing tool 30 and the magnetic adsorption force of the permanent magnet 33, which is determined by the abrasive grains 35. Various settings will be made according to the maximum magnetic adsorption layer thickness dimension.
Since the heads of hexagonal bolts and hexagonal nuts are to be polished, the shape is circular so that they can be covered with plenty of room.

Next, the operation of the hand-held polishing apparatus of this embodiment will be explained.

When the motor 1 is started with the cup-shaped polishing tool 30 attached and fixed to the chuck portion 20, the eccentric shaft 11 rotates integrally with the motor shaft 3, and the ball bearing 12, which rotates eccentrically in response, rotates in the elongated hole. By relatively moving up and down inside the ball bearing 14, the displacement of the left-right component of the ball bearing 12 is substantially transmitted to the slider 10. That is,
If the eccentricity of the eccentric shaft 11 with respect to the motor shaft 3 is E, then the displacement of the ball bearing 12 with respect to the axial center of the motor shaft 3 will take the maximum distance E in the vertical and horizontal directions, but the ball bearing 1
2 moves up and down relatively inside the elongated hole 14, which has a length more than twice the eccentricity E in the up-down direction.
The slider 10 is not substantially subjected to the displacement of the vertical component of the ball bearing 12;
It is displaced left and right following the displacement of the left and right component of. Therefore, when the slider 10 is repeatedly displaced in the left-right direction, the support ring 9 into which the slider 10 is fitted rotates relatively slightly around the slider 10 in response to the displacement. , the arm 7 swings around the spindle 6, causing the spindle 6 to
It is driven to rotate reciprocatingly at a small rotation angle of 10 to 10 degrees.

Due to such reciprocating rotational driving of the spindle 6, the cup-shaped polishing tool 30 mounted and fixed on the chuck portion 20 is given a reciprocating rotational movement so as to vibrate integrally with the spindle 6 and concentrically therewith. In this state, when the cup-shaped polishing tool 30 is placed over a protrusion 36 such as a bolt head or a nut, the polishing stone held on the inner surface of the recess 34 is magnetically attracted to the entire surface of the permanent magnet 33 in a relatively thin manner. The grains 35 come into contact with a wide range of the surface of the protrusion 36 so as to fill the space between the surface and the protrusion 36, and the cup-shaped polishing tool 30 vibrates and reciprocates,
The abrasive grains 35 repeatedly make minute relative movements within the recess while contacting and polishing the entire surface of a protrusion 36 such as a bolt head, thereby efficiently removing rust, paint, etc. from the surface. When removing rust, paint, etc., the abrasive grains 35 are applied to the cup-shaped polishing tool 3.
Due to the vibration-like reciprocating rotational movement of the bolt, the entire surface of the protrusion 36 is contacted while repeating minute relative movements within the recess. Achieve a good surface finish without significant damage to the surface.

In particular, since the spindle 6 on which the cup-shaped polishing tool 36 is mounted is not rotated at high speed in one direction but is driven to reciprocate in a vibrating manner, there are no corners on the outer circumferential surface of the spindle 6, such as a hexagonal bolt or a hexagonal nut. When polishing a certain surface, there is no risk that the gripping part 2 will be swung around by the rotational torque of the spindle 6 during the work, and the state in which the gripping part 2 is supported by the operator is extremely stable.
This improves the safety of polishing work in work environments with poor footing, such as bridges. Furthermore, in such polishing work, the corners of the outer circumferential surface of hexagonal bolts are not significantly scraped off and rounded, making it difficult to retighten the hexagonal bolts after the polishing work. do not have.

Although the cup-shaped polishing tool of the present invention has been described above in detail based on the embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist thereof.

For example, in the above embodiment, the recess with magnetic attraction force was constructed by fixing a permanent magnet to the inner surface of a cylinder made of metal or highly rigid resin, which had an opening at one end and a closed end at the other end. The invention is not limited to this, and the recesses may be formed directly on the permanent magnet, and the abrasive grains are not limited to those coated with an abrasive on the surface of a magnetic material with a small particle size, but may be simply magnetic. It may also be body particles.

[Effect of idea]

The cup-shaped abrasive tool is mainly made of a material with magnetic attraction and has a concave portion on one side, and is configured by adsorbing abrasive grains containing a magnetic substance to the concave portion. When placed over a protruding part such as a bolt head or nut, the abrasive grains held on the recessed surface by magnetic attraction spread over a wide area of the protruding surface so as to fill the space between the recessed surface and the protruding part. By applying vibration to the concave part through reciprocating rotational motion in this state, the abrasive grains repeat minute relative movements within the concave part and polish the protrusion surface, thereby polishing the bolt head etc. Rust, paint, etc. can be efficiently removed from the surface of the protrusion without damaging the underlying surface of the protrusion, thereby increasing the efficiency of polishing the protrusion surface and achieving a good finished state.

Furthermore, the spindle on which the cup-shaped polishing tool is attached is driven to reciprocate and rotate in a vibrating manner, so when polishing surfaces with corners on the outer circumference, such as hexagonal bolts and hexagonal nuts, the There is no risk of the gripping part being swung around by the rotating torque of the spindle, and the gripping part can be supported by the operator in an extremely stable manner, making it possible to improve the safety of polishing work in a work environment with poor footing.

In addition, since the inner surface of the recess is circular, the corners of the outer circumferential surface of hexagonal bolts, etc., will not be significantly scraped off and become rounded, and this will prevent the situation where it becomes difficult to retighten the hexagonal bolt after polishing work. .

[Brief explanation of the drawing]

The drawings show one embodiment of a hand-held polishing device according to the present invention, and FIG. 3 is a sectional view taken along the line AA in the figure, FIG. 3 is a sectional view taken along the line BB in FIG. 2, and FIG. 4 is a bottom view of the cup-shaped polishing tool. 3...Motor shaft, 6...Spindle, 7...Arm, 8...Cylindrical surface, 9...Support ring, 10...
... Slider, 11 ... Eccentric shaft, 12 ... Ball bearing, 14 ... Long hole, 30 ... Cup-shaped polishing tool, 31 ... Rod, 32 ... Cylindrical body, 33 ... Permanent magnet, 34 ... ...Concavity, 35...Abrasive grain, 36
……protrusion.

Claims (1)

[Claims for Utility Model Registration] A cup-shaped polishing tool for polishing the surface of a hexagonal workpiece having a predetermined thickness is attached to a protrusion of a spindle that is driven to reciprocate and rotate protruding from a grasping part. The cup-shaped polishing tool has one end fixedly fixed, and the cup-shaped polishing tool is mainly made of a material having magnetic attraction, and a recess with a circular cross section is formed in the other end, and the inner surface of the recess has a polishing abrasive containing a magnetic material. The period during which the grains are magnetically attracted and the abrasive grains placed on the surface of the hexagonal workpiece flow due to the reciprocating rotation of the spindle is the diagonal portion of the hexagonal workpiece. and the inner surface of the recess.