JP2014039975A - Orbital sander - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an orbital sander arranged so as to mutually negate an unbalance by eccentricity.SOLUTION: A grinding pad is divided into the outside (13) and the inside (14) of a concentric circle around an output shaft 3 provided downward in a body housing 2, and eccentric parts (8 and 10) having the symmetric eccentric direction to the axial center, are provided by two on the output shaft 3 by being dislocated in the axial direction of the output shaft, and the unbalance by the eccentricity is mutually negated by respectively supporting the grinding pad by the respective eccentric parts. Dust is sucked by providing a suction port 18 for sucking the dust generated by grinding in a clearance 26 existing between an outside pad 13 and an inside pad 12.

Description

  The present invention relates to an orbital sander including a grinding pad that projects an output shaft of a motor below a main body housing and moves eccentrically below the motor output shaft.

  The orbital sander projects the motor output shaft (rotary shaft) below the main body housing, and connects the grinding pad orthogonally to the output shaft at a position eccentric from the axis of the output shaft. The workpiece can be ground by making the grinding pad eccentric (orbital). Such an orbital sander generates vibration with the orbital motion of the grinding pad.Therefore, a counterweight is provided on the opposite side to the eccentric side in order to reduce the vibration, and the counterweight is reversely decentered. We are trying to make adjustments. In Patent Document 1, at least one pair of spindles is supported in parallel with the output shaft at symmetrical positions around the output shaft of the motor, and a pair of pads are orthogonal to the lower ends of both spindles and the spindle shaft. A sander provided to be eccentric to the opposite sides of the heart is disclosed.

JP 2002-233941 A

  In the eccentric structure disclosed in Patent Document 1, a pair of spindles that support the grinding pad including the drive output gear in addition to the motor output shaft leads to an increase in cost. In the random orbital sander that also rotates, there is a problem that the area cannot be made sufficiently large with respect to the tool because two circular grinding pads that rotate automatically lie side by side.

  The present invention has been made in view of the above background, and its purpose is to reduce the cost by arranging the two pads in the direction of canceling vibrations with the spindle as the motor output shaft only, and the grinding pad can be used only for the eccentric motion. In addition, a random sander that rotates in a rotating manner can be efficiently arranged without side-by-side grinding pads.

  The orbital sander according to the present invention has an eccentric portion having an eccentric direction symmetrical to the output shaft centered on the output shaft by dividing the grinding pad into an outer side and an inner side of a concentric circle around an output shaft provided downward in the main body housing. Are arranged so as to be offset in the axial direction of the output shaft, and the respective eccentric parts support the grinding pad so as to cancel the unbalance due to the eccentricity.

  According to the first aspect of the present invention, the grinding pad is divided into the outer side and the inner side of the concentric circle around the output shaft provided downward in the main body housing, and the eccentric direction is symmetrical with respect to the output shaft. Two eccentric parts with slabs are shifted in the axial direction of the output shaft, and each eccentric part supports each pad so that the unbalance caused by the eccentricity is canceled out. Therefore, only one spindle for pad support is provided. In addition, in a random orbital sander where the grinding pad not only performs eccentric motion but also rotates due to the grinding pad divided into the concentric circle outside and inside, the grinding pad area is reduced because it is not necessary to arrange the grinding pads side by side. Can be large enough for the tool.

  According to the invention described in claim 2, since the outer pad is substantially annular and the inner pad is substantially circular, a grinding pad that is easy to manufacture and has a high rigidity feeling can be realized.

  According to the third aspect of the present invention, when the grinding pad is divided into the outer side and the inner side of the concentric circle, there is a gap between the outer pad and the inner pad, so that the gap is provided in the main body from the surface of the grinding pad. It can be used as a flow path for conveying dust generated by grinding to a dust collecting fan, and the gap on the surface of the grinding pad can be used as a suction port for dust generated by grinding.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

It is a longitudinal cross-sectional view of the orbital sander concerning the Example of this invention. It is a bottom view of the orbital sander concerning the example of the present invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the present specification, description will be made assuming that the front-rear and up-down directions are the directions shown in the drawing. FIG. 1 is a longitudinal sectional view of an orbital sander according to an embodiment of the present invention.

  The orbital sander is a tool for grinding a material to be ground while moving the grinding pad in a non-circular locus, for example, in an orbital shape, through an eccentric portion connected to the output shaft 3 of the motor 4. Inside the main body housing 2 formed of a polymer resin such as plastic, a motor 4 is disposed so that the output shaft 3 extends in the vertical direction when the grinding surface is in the horizontal direction. A grip portion 6 is formed in the upper portion of the main body housing 2, and the motor 4 is driven to rotate by turning on a switch 5 provided near the front of the grip portion 6. An anti-rotation cut is provided below the output shaft 3, and a motor cooling and dust suction fan 7 is fitted therein to be fixed to the output shaft 3. A first eccentric portion 8 is provided on the lower surface side of the fan 7, and a pad holder 16 is rotatably attached thereto via a ball bearing 9. Further, the second eccentric portion 10 is fitted and fixed to the output shaft 3 so that the second eccentric portion 10 is engaged with a rotation preventing cut portion provided on the output shaft 3 so as to restrain the lower surface side of the inner ring of the ball bearing 11. There, a pad holder 12 is rotatably mounted via a ball bearing 11.

  The pad holder 16 on the outer peripheral side is fixed by a substantially cylindrical grinding pad 13 screw 15a, and an abrasive is fixed to the lower surface of the grinding pad 13. A grinding pad 14 is fixed to the inner peripheral pad holder 12 by 15b, and an abrasive is fixed to the lower surface of the grinding pad 14. The first eccentric portion 8 provided on the lower surface side of the fan 7 and the second eccentric portion 10 provided below the first eccentric portion 8 are 180 ° out of phase with respect to the rotation center of the output shaft 3 and cancel each other out of imbalance. Arranged to match.

  In the present embodiment, a dust collection mechanism for sucking dust generated by grinding is provided, and the suction port 18 is disposed so as to open in a gap portion between the outer grinding pad 13 and the inner grinding pad 14. The Since a gap 26 is formed between the grinding pads 13 and 14 and the pad holders 16 and 12, dust generated by grinding the work material with the abrasive of the grinding pads 13 and 14 is used as a flow path. As indicated by the arrows in the figure, the air is sucked by the suction force of the fan 7 and discharged to the dust collecting bag 17 connected to the rear side of the main body housing 2.

  FIG. 2 is a bottom view of the orbital sander according to the embodiment of the present invention. The outer grinding pad 13 has an annular shape with a circular inner edge and a circular outer edge, and is fixed to the pad holder 16 (see FIG. 1) by three screws 15a at equal intervals in the circumferential direction. Similarly, the inner grinding pad 14 is circular, and is fixed to the pad holder 12 (see FIG. 1) by three screws 15b at equal intervals in the circumferential direction. The orbital sander 1 of the present embodiment is called a random orbital sander because the grinding pads 13 and 14 rotate not only eccentrically but also rotate due to the rotation of the motor 4. In addition, if the grinding pads 13 and 14 that rotate are connected to the main body housing 2 by some method and the rotation is restricted, a general orbital sander is obtained. Here, as can be understood from FIG. 2, the center of the grinding pad 13 and the center of the grinding pad 14 are offset with respect to the rotation axis of the motor, and are symmetrical with respect to the center of the output shaft (rotation axis). It is configured so as to be in an eccentric direction.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, in the above-described embodiment, the grinding pads 13 and 14 are constituted by a circular pad and an annular pad. However, the present invention is not limited to these configurations. These pads and an arbitrarily shaped pad disposed on the inner periphery of the outer peripheral pad may be used.

DESCRIPTION OF SYMBOLS 1 Orbital sander 2 Main body housing 3 Output shaft 4 Motor 5 Switch 6 Grip part 7 Fan 8 1st eccentric part 9 Ball bearing 10 2nd eccentric part 11 Ball bearing 12 Pad holder 13 Grinding pad 14 Grinding pad 15a, 15b Screw 16 Pad holder 17 Dust collection bag 18 Suction port 26 Clearance

Claims (3)

A motor disposed so that an output shaft extends in a direction perpendicular to the polishing surface; a housing that houses the motor; an eccentric portion that is connected to the output shaft and converts rotational motion of the output shaft into eccentric motion; and An orbital sander having a grinding pad held on an eccentric part,
The grinding pad is composed of two pads that are divided into an outer side and an inner side of a concentric circle,
An orbital characterized in that two eccentric parts are provided by shifting in the axial direction so as to have an eccentric direction symmetric with respect to the axial center of the output shaft, and each of the eccentric parts supports an outer pad and an inner pad. Sanda.   The orbital sander according to claim 1, wherein the outer pad is substantially circular and the inner pad is substantially circular.   The orbital sander according to claim 1 or 2, wherein a suction port for sucking dust generated by grinding is provided in a gap portion between the outer pad and the inner pad.

Images