JP2009190132A - Grinding tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve usability of a random orbital sander by preventing a dust box from improperly turning around in the handheld random orbital sander, since dust collection fan and a dust collection skirt are arranged above a grinding pad to collect generated dust in the dust box, and the dust collection skirt is conventionally turned to an optional position so as to prevent the dust box from causing an obstruction to work, but there lies a problem of the dust box improperly turning around with rotation of the dust collection skirt due to vibration or the like. <P>SOLUTION: The dust collection skirt 21 is formed in a halved structure, and split pieces 21L, 21R are brought into butt contact with each other and mounted to a tool body 2. Thus a noncircular restricting part 30 of the tool body 2 is pinched between rotation locking parts 24, 24, and the rotation of the dust collection skirt 21 around an axis J1 is restricted to hold a direction of the dust box 26. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a hand-held grinding tool used by a user and is attached to a grinding tool such as sandpaper, and for example, an orbital motion (combined motion of rotational motion and eccentric motion) is attached thereto. The present invention relates to a grinding tool such as a so-called random orbital sander that feeds and grinds a workpiece.

For example, the following patent document discloses a technique related to this type of grinding tool. This grinding tool includes a dust collection skirt for collecting dust and the like generated by grinding. According to this prior art, a dish-shaped dust collection skirt is provided in the main body case so as to cover the periphery of the grinding tool or grinding pad, and a dust box (dust collection bag) is connected to the side of the dust collection skirt. The dust collecting skirt is rotated to an arbitrary position (orientation) according to (working posture) so that the dust box does not interfere with the work.
US Pat. No. 5,518,442

However, in the conventional grinding tool, the dust collecting skirt is supported on the main body case in a state of being rotatable around the rotation axis of the grinding pad, and by giving an appropriate rotational resistance (friction resistance) to the support portion, The dust collection skirt is rotated to an arbitrary position so that the direction of the dust box can be changed, and the rotation position of the dust collection skirt and thus the direction of the dust box is maintained. For this reason, during work, the dust box is inadvertently changed as a result of large vibrations or impacts on the dust collection skirt or dust box, or the user's hand touching them, and it is necessary to improve the usability in this respect. there were.
According to the present invention, the direction of the dust box can be arbitrarily changed according to the mode of operation, and the dust collection skirt is securely held at the position once changed without causing the direction of the dust collection skirt to be inadvertently shifted due to vibration or the like as in the prior art. The purpose is to do so.

For this reason, the present invention is a grinding tool having a configuration described in each of the claims.
According to the grinding tool of the first aspect, the dust collecting skirt is divided into a plurality of divided pieces in the direction around the axis of the output shaft. For this reason, the divided pieces are separated from each other by separating them on the radially outer side of the output shaft, thereby removing the dust collecting skirt from the tool body with the dust collecting fan and the grinding pad attached to the output shaft. be able to. If the divided pieces are brought close to the radial center of the output shaft and joined to each other with the dust collection skirt removed, the dust collection skirt is changed to a different position around the axis of the output shaft. It can be attached to the tool body, thereby changing the orientation of the dust box.
Moreover, in this attached state, since at least one divided piece is prevented from rotating with respect to the tool body, as a result, the dust collecting skirt is attached in a state of being prevented from rotating relative to the tool body as a whole. From the above, according to the grinding tool according to claim 1, the dust box can be arbitrarily changed by removing the dust collecting skirt, changing the dust collecting skirt, and then attaching the dust collecting skirt to the tool body again. Can be securely held by the rotation preventing portion, and the inconvenience that the position of the dust box is inadvertently shifted as in the prior art can be eliminated.

According to the grinding tool of the second aspect, the direction of the connection port can be changed by dividing the dust collecting skirts and changing the positions around the axis of the output shaft to different positions. The dust box can be arbitrarily changed to a position that does not interfere with the work, and the position can be securely held by the rotation preventing portion.
Compared to the configuration that can be divided into three or more divided pieces by dividing the annular dust collection skirt that covers the entire circumference of the dust collecting fan into two divided pieces. Therefore, it is possible to minimize the time required for separating and joining the divided pieces.
According to the grinding tool of claim 3, when the two divided pieces are brought close to each other and attached to the tool main body, the non-circular restricting portion of the tool main body is sandwiched from both radial directions by the two divided pieces. The position of the dust skirt around the axis of the output shaft with respect to the tool main body is regulated, so that the changed position of the dust collecting skirt can be reliably held.
The non-circular restricting portion has an elliptical shape, a triangular shape, a rectangular shape, a polygonal shape, a star shape, or a serrated shape as viewed from the axial direction of the output shaft, and has a shape (engagement portion) that is at least deviated from the same circle on the peripheral surface. Can be provided. As the number of engaging portions on the peripheral surface of the non-circular restricting portion around the axis of the output shaft increases, the selection range of the changeable position of the dust collection skirt (the direction of the dust box) increases, and the usability becomes higher in this respect.
According to the grinding tool of the fourth aspect, the direction of the dust collecting skirt can be changed by selecting an arbitrary position from eight positions around the axis of the output shaft, and the changed position of the dust collecting skirt is It is securely held by the detents provided on the divided pieces, and does not move carelessly due to vibration or the like as in the prior art.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 show the entire grinding tool 1 according to the present embodiment. The grinding tool 1 is a hand-held grinding tool that is used by a user and is a so-called random orbital sander. The basic structure of the tool body 2 of the grinding tool 1 is the same as that of the prior art, and no particular change is required in this embodiment. The tool body 2 includes a body case 3 having a so-called half structure. On the upper part of the main body case 3, a grip portion 4 that is held by a user with one hand is provided. A power cord 5 is connected to the side of the grip 4.
A drive motor 6 for the grinding tool 1 is built in the main body case 3. The drive motor 6 is activated using the AC power supplied from the power cord 5 as a power source. The drive motor 6 is started and stopped by an on / off operation of a switch (not shown).
An output shaft 6 a of the drive motor 6 protrudes downward from the lower part of the main body case 3. The lower part of the main body case 3 is formed in a mortar shape that opens downward as illustrated. A disc-shaped support plate 7 is attached to the lower surface of the main body case 3 whose lower portion is opened in a mortar shape. The support plate 7 is attached so as to close the opening of the main body case 3 that is opened in a mortar shape, and is fixed by fixing screws 8 to 8.

A bearing 9 is attached to the inner periphery of the support plate 7. The output shaft 6 a is rotatably supported by the bearing 9. A dust collecting fan 10 is attached to the output shaft 6 a protruding downward from the support plate 7. The dust collecting fan 10 rotates integrally with the output shaft 6a. The dust collecting fan 10 includes an eccentric boss portion 10a. The eccentric boss portion 10a is eccentric with respect to the axis J1 of the output shaft 6a of the drive motor 6. In the drawing, the reference J2 is attached to the central axis of the eccentric boss 10a. A bearing 11 is attached to the outer peripheral side of the eccentric boss portion 10a. The pad base 12 is supported via the bearing 11 so as to be rotatable about the axis J2 of the eccentric boss portion 10a. A grinding pad 13 is attached to the pad base 12. The grinding pad 13 is fixed to the pad base 12 with fixing screws 14 to 14. For this reason, the grinding pad 13 rotates integrally with the pad base 12. A grinding tool 15 is attached to the lower surface of the grinding pad 13. As the grinding tool 15, for example, a grinding paper called a sanding disk is used.
When the drive motor 6 is activated and the output shaft 6a rotates, the dust collecting fan 10 rotates as a unit. Therefore, the eccentric boss portion 10a revolves around the axis line J1, whereby the grinding pad 13 revolves around the axis line J1 (orbital). The grinding pad 13 rotates around the axis J2. In this way, the workpiece W is ground by the grinding tool 15 by rotating around the axis J2 while the grinding pad 13 orbitally moves around the axis J1.
The grinding pad 13 is provided with a plurality of dust collection holes 13a to 13a for releasing dust generated by grinding. Each dust collection hole 13 a is provided in a state of penetrating in the thickness direction of the grinding pad 13. Dust is collected (absorbed) upward by the rotation of the dust collection fan 10 through the dust collection holes 13a to 13a.

An annular dust collecting skirt 21 is supported around the dust collecting fan 10 and below the tool body 2. The dust collection skirt 21 is attached along the lower part of the tool body 2. The dust collecting skirt 21 covers the periphery of the dust collecting fan 10.
The dust collection skirt 21 in the present embodiment has a so-called halved structure, and can be divided into two divided pieces 21L and 21R in the radial direction with respect to the axis J1 of the output shaft 6a. The dust collecting skirt 21 can be removed from the tool body 2 by separating the two divided pieces 21L and 21R each having a semicircular arc shape from each other.
The removed dust collection skirt 21 is shown alone in FIG. The two divided pieces 21L and 21R are formed bilaterally symmetric (unusual). When viewed from the user, the left divided piece is denoted by reference numeral 21L, and the right divided piece is denoted by reference numeral 21R. A user is located on the right side of the grinding tool 1 in FIGS. 1 and 2 and holds the grinding tool 1.
Coupling portions 21a and 21b are provided at both ends in the circumferential direction of the right split piece 21R indicated by the solid line in FIG. Correspondingly, coupling portions 21c and 21d are provided at both ends in the circumferential direction of the left split piece 21L indicated by a two-dot chain line in FIG. Between the left and right divided pieces 21L and 21R, the front side (left side in FIG. 5) coupling parts 21a and 21c and the rear side (right side in FIG. 5) coupling parts 21b and 21d are screw-coupled to each other. The divided pieces 21L and 21R are connected to each other to form an annular dust collecting skirt 21 and attached to the tool body 2 in this state.

Semi-cylindrical connection port pieces 22a and 22b are integrally provided at rear ends of the left and right divided pieces 21L and 21R so as to protrude rearward. When the left and right divided pieces 21L and 21R are fixed to each other, the connection port pieces 22a and 22b are abutted with each other to form one connection port 22 having a cylindrical shape. A dust box 26 is connected to the connection port 22.
Engagement groove portions 23 that open toward the inner peripheral side are provided over the entire circumference of the upper portions of the left and right divided pieces 21L and 21R. When the dust collecting skirt 21 is attached to the tool body 2 by abutting the left and right divided pieces 21L and 21R to form an annular shape, the left and right divided pieces 21L and 21R are arranged along the left and right engaging groove portions 23 and 23 as shown in FIG. The peripheral edge 7a of the support plate 7 is fitted. Thereby, the positional deviation of the left and right divided pieces 21L and 21R and the dust collecting skirt 21 in the direction of the axis J1 is restricted.
A plurality of engaging recesses 24a cut into a triangular shape (V-shape) from the inner peripheral side are provided at equal intervals in the circumferential direction on the lower inner peripheral edge 24b forming the engaging groove 23. When the annular divided dust collecting skirt 21 is formed by abutting the left and right divided pieces 21L and 21R, a total of eight engaging recesses 24a to 24a are formed on the inner peripheral edges 24b and 24b over the entire circumference. The eight engaging recesses 24 a to 24 a and inner peripheral edges 24 b and 24 b provided with the engaging recesses 24 a to 24 a on the inner peripheral side constitute a detent portion 24. The rotation stopper 24 corresponds to an example of a rotation stopper described in the claims.

On the other hand, a non-circular restricting portion 30 is provided on the lower surface of the support plate 7 so as to protrude one step in the thickness direction. As shown in FIGS. 3 and 4, the non-circular restricting portion 30 of the present embodiment has eight triangular engaging convex portions protruding outward in the radial direction when viewed from the direction of the axis J1 (downward) of the output shaft 6a. 30a-30a, 30b-30b is provided with the shape arrange | positioned at the circumferential direction equal intervals. Each engagement convex part 30a-30a, 30b-30b is formed in the magnitude | size which can enter into each engagement recessed part 24a of the dust collection skirt 21 without gap. However, as shown in FIG.3 and FIG.4, about the engagement convex part 30b-30b of every other 4 places among the eight engagement convex parts 30a-30a, 30b-30b, the said support plate 7 is used. An insertion hole 7b for inserting a fixing screw 8 to be fixed to the tool body 2 is formed, and the tip side is allowed to escape in a semicircular shape in order to avoid interference with the head of the fixing screw 8 inserted through the insertion hole 7b. Has been.
In order to attach the dust collecting skirt 21 to the tool body 2, when the left and right divided pieces 21 </ b> L and 21 </ b> R are butted against each other in an annular shape, the peripheral edge of the support plate 7 along the left and right engagement grooves 23 and 23. 7a is fitted in the direction of the axis J1 with almost no gap, and the non-circular restricting portion 30 of the support plate 7 is sandwiched between the lower inner peripheral edges 24b, 24b from both sides in the radial direction.

As shown in FIG. 3, when the non-circular restricting portion 30 is sandwiched between the inner peripheral edges 24b, 24b of the left and right split pieces 21L, 21R, the non-circular restricts are placed in the engagement recesses 24a-24a on the split pieces 21L, 21R side. The engaging projections 30a and 30b on the side of the portion 30 are fitted and engaged with each other in the circumferential direction. Further, in this state, the same triangular engagement convex portion formed between the two adjacent engagement concave portions 24a and 24a on the dust collection skirt 21 side is also adjacent two engagement on the non-circular restriction portion 30 side. It is in a state where it has entered the same triangular engagement recess formed between the protrusions 30a and 30b without any gap.
Thus, the engagement concave portions 24a to 24a (circumferential concave and convex portions) on the dust collection skirt 21 side and the engagement convex portions 30a to 30a and 30b to 30b (circumferential concave and convex portions) on the non-circular restricting portion 30 side are circumferential directions. , The rotation of the dust collection skirt 21 around the axis J1 with respect to the tool body 2 is regulated. In this restricted state, the dust collecting skirt 21 is connected between the coupling portions 21a and 21c on the front side (left side in FIG. 3) and the coupling portions 21b and 21d on the rear side (right side in FIG. 3) with fixing screws. Is fixed to the tool body 2 so that it cannot rotate about the axis J1 and cannot be displaced in the direction of the axis J1.
Since the dust collecting skirt 21 meshes with the non-circular restricting portion 30 on the tool body 2 side and is mounted so as not to rotate around the axis J1, the direction of the dust box 26 (position around the axis J1) is securely held, Thus, the position is not inadvertently displaced due to vibration or the like.
The opening on the lower side of the dust collection skirt 21 is closed by the auxiliary plate 25. However, the auxiliary plate 25 is provided with a large number of dust collection holes 25a penetrating in the thickness direction so that the dust collection efficiency by the dust collection fan 10 is not impaired.

When removing the attached dust collecting skirt 21 from the tool body 2, the fixing screws between the front coupling portions 21a and 21c and between the rear coupling portions 21b and 21d are removed, and the dust box 26 is once removed from the connection port 22. In this state, the left and right divided pieces 21L and 21R may be separated from each other by separating them from the axis J1 radially outward (to the left and right).
In the removed state, the connection port pieces 22a and 22b are changed to an arbitrary direction, and the two split pieces 21L and 21R are again brought close to each other toward the center of the radial direction with respect to the axis J1, thereby making contact with each other. The dust collecting skirt 21 can be attached to the front, whereby the direction of the connection port 22 can be arbitrarily changed.
The direction of the changed connection port 22 is ensured by the inner peripheral edges 24b, 24b meshing with the non-circular restricting portion 30 in the circumferential direction as described above and the rotation is restricted around the axis J1 of the dust collecting skirt 21. Retained.
According to the present embodiment, as described above, a total of eight engaging recesses 24a to 24a are provided on the dust collecting skirt 21 side at equal intervals in the circumferential direction (accordingly, 45 ° intervals), and the non-circular shape on the tool body 2 side. The regulating portion 30 is also provided with a total of eight engaging convex portions 30a to 30a and 30b to 30b at equal intervals (accordingly, 45 ° intervals) in the circumferential direction. Therefore, the dust collection skirt 21 can be positioned and attached at any position selected from eight locations with respect to the position around the axis J1 (the direction of the dust box 26).

According to the grinding tool 1 of the present embodiment configured as described above, the dust collecting skirt 21 has a halved structure that can be separated into the left and right divided pieces 21L and 21R around the axis J1 of the output shaft 6a. Therefore, it can be easily removed from the tool body 2 and attached in reverse without performing a troublesome operation such as removing the grinding pad 13.
In addition, with the dust collecting skirt 21 removed from the tool body 2, the left and right divided pieces 21L and 21R are changed to different positions (arbitrary positions among the eight positions) around the axis J1 of the output shaft 6a. By attaching to the main body, the dust collecting skirt 21 can be attached by changing the position around the axis line J1, and by extension, the direction of the connection port 22 and thus the dust box 26 can be attached.
Moreover, in this attached state, the non-circular restricting portion 30 on the tool body 2 side is sandwiched between the rotation preventing portions 24, 24 provided on the left and right divided pieces 21L, 21R from both sides in the radial direction (both left and right sides). Since the engagement concave portions 24a to 24a on the dust skirt 21 side and the engagement convex portions 30a to 30a and 30b to 30b on the non-circular restriction portion 30 side are engaged with each other in the circumferential direction, the attached dust collection skirt 21 The rotation around the axis line J1 is restricted, and this prevents the direction of the dust box 26 from being inadvertently changed by vibration or the like.
Therefore, the user can attach the dust collection skirt 21 by changing the dust box 26 to a position that does not interfere with the work according to the work form (work posture), and this position is securely held. Therefore, grinding work can be performed efficiently.

The embodiment described above can be implemented with various modifications. For example, although the configuration in which the left and right divided pieces 21L and 21R are separated is illustrated, it may be divided into three or more divided pieces.
In addition, a total of eight engaging recesses 24a to 24a are provided as the anti-rotation portion 24 on the dust collection skirt 21 side, and the eight engaging protrusions 30a to 30a and 30b to 30b of the non-circular portion 30 are correspondingly provided. However, the rotation of the dust collecting skirt 21 around the axis J1 can be restricted by providing at least two engaging concave portions and engaging convex portions that mesh with each other. From this, the non-circular restricting portion in the present invention is other than a circle centered on the axis J1 such as an ellipse, a triangle, a rectangle, a polygon, a star, or a serration when viewed from the direction of the axis J1 of the output shaft 6a. The shape can be a shape having a portion that is displaced from the same circle centered on the axis J1 to the radially outer peripheral side or the inner peripheral side as an engaging portion. Similar effects can be obtained by providing an appropriate number of engaging portions.
One non-circular restricting portion on the tool body 2 side is provided, and a plurality of engaging portions are provided on the anti-rotation portion on the dust collecting skirt side, or vice versa. A plurality of engaging portions may be provided, and one engaging portion may be provided on the anti-rotation portion on the dust collecting skirt side. With these configurations, the positions around the axis J1 of the dust collecting skirt are determined at a plurality of locations. Accordingly, the direction of the dust box can be held at an arbitrary position selected in accordance with the work form, and it is possible to prevent the dust box from being inadvertently moved due to vibration during work or the like.

1 is an overall side view of a hand-held grinding tool according to an embodiment of the present invention. It is a partially broken side view of a hand-held grinding tool. This figure is the lower part of the grinding tool, and the dust collecting skirt and its periphery are shown in a longitudinal sectional view. FIG. 3 is a view taken in the direction of arrows (3)-(3) in FIG. It is a perspective view of a single support plate. This figure has shown the state which looked at the support plate from diagonally downward. It is a perspective view of the dust collection skirt simple substance concerning this embodiment. This figure has shown the state which looked at the state which isolate | separated the dust collection skirt into right and left from diagonally upward. The right divided piece is indicated by a solid line, and the left divided piece is indicated by a two-dot chain line.

Explanation of symbols

1 ... Grinding tool (hand-held orbital sander)
DESCRIPTION OF SYMBOLS 2 ... Tool body 3 ... Main body case 4 ... Grip part 6 ... Drive motor, 6a ... Output shaft J1 ... Axis 7 of output shaft 6a ... Support plate, 7a ... Peripheral part, 7b ... Insertion hole 10 ... Dust collecting fan, 10a ... Eccentric boss J2 ... axis 12 of eccentric boss 10a ... pad base 13 ... grinding pad, 13a ... dust collection hole 21 ... dust collection skirt, 21a to 21d ... coupling part 21L ... split piece (left side), 21R ... split piece ( Right)
22 ... Connection port, 22a ... Connection port piece (right side), 22b ... Connection port piece (left side)
23 ... Engaging groove 24 ... Anti-rotation part, 24a ... Engaging recess 26 ... Dust box 30 ... Non-circular restriction part, 30a, 30b ... Engaging convex part

Claims (4)

A grinding tool that supports a grinding pad for attaching a grinding tool to an output shaft of a tool body,
A dust collection skirt that is supported by the tool body in a state of covering the periphery of a dust collection fan attached to the output shaft and has a connection port for connecting a dust box on a side part,
The dust collection skirt is divided into a plurality of divided pieces about the axis of the output shaft, each divided piece is separated from the tool body in the radial direction of the output shaft, It can be attached to the tool body close to the radial direction,
A grinding tool having at least one divided piece of the plurality of divided pieces, the rotation preventing portion for restricting a position around the axis of the output shaft with respect to the tool body. 2. The grinding tool according to claim 1, wherein the dust collecting skirt is divided into two divided pieces around the axis of the output shaft, and the anti-rotation portion is provided on at least one of the divided pieces. 3. . 3. The grinding tool according to claim 2, wherein a non-circular non-circular restricting portion is provided on the tool body around the axis of the output shaft, and the non-circular restricting portion is radiated by the anti-rotation portions of the two split pieces. A grinding tool configured to restrict the position of the dust collection skirt around the axis of the output shaft by sandwiching from both sides in the direction. 4. The grinding tool according to claim 3, wherein the non-circular restriction portion includes eight engaging portions at equal intervals around the axis of the output shaft.

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