JP2013202734A - Power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent increase in operation resistance of a base, and to extend the maintenance cycle of posts.SOLUTION: A first recess and protrusion engagement portion 50 and a second recess and protrusion engagement portion 60 are provided between a fan guide 23 and one end portion 40a of a leg 40 and between a base plate 31 and the other end portion 40b of the leg 40, respectively, make the fan guide 23 and one end portion 40a swingably abut on each other and make the base plate 31 and the other end portion 40b swingably abut on each other, respectively, and restrict a deviation of the leg 40 relative to the fan guide 23 and the base plate 31 in a horizontal direction while allowing swinging of the leg 40 relative to the fan guide 23 and the base plate 31. The leg 40 can swing with almost no resistance without involving any elastic deformation during orbital motion of the base 30, and stress to cause elastic deformation is not applied to the leg 40 unlike the conventional art. Therefore, the increase in the operation resistance of the base 30 can be prevented, and the life of the leg 40 can be prolonged to extend the maintenance cycle.

Description

  The present invention includes a main body having a driving source, a rotating shaft provided in the driving source, and a base that moves in a horizontal direction with respect to the main body as the rotating shaft rotates, and is held by the base The present invention relates to a power tool that performs a grinding operation using a polished sheet.

  Conventionally, a power tool has been used to efficiently grind and smooth the surface of wood or the like. The power tool includes a main body having a drive source, a rotary shaft provided in the drive source, and rotation of the rotary shaft. Accordingly, there is a so-called orbital sander having a base that moves in a horizontal direction (performs orbital movement) with respect to the main body. The base holds abrasive paper (abrasive sheet), which allows the user to grip the grip of the main body and rotate the drive source to push the abrasive paper against the surface of wood or the like. By hitting, the base orbitally moves with respect to the main body, and as a result, the surface of wood or the like can be ground and smoothed efficiently.

  As such an orbital sander (power tool), for example, an electric tool described in Patent Document 1 is known. The electric tool (power tool) described in Patent Document 1 houses a motor (driving source) in a housing (main body portion), and a shaft of the motor shaft is disposed on the tip side of the motor shaft (rotating shaft) of the motor. A ball bearing is provided to be eccentric with respect to the center. In addition, a base having a pad for holding abrasive paper is fixed to the ball bearing, and a plurality of flexible legs (posts) are provided between the housing and the base and around the ball bearing. ing. These legs allow the base to swing relative to the housing around the ball bearing while restricting relative rotation of the base with respect to the housing. As a result, the base ( Abrasive paper) is orbital.

Japanese Patent Laid-Open No. 2008-100302 (FIG. 1)

  However, according to the power tool described in Patent Document 1 described above, one end of each column is fixed to the main body, and the other end of each column is fixed to the base. Each time the base performs an orbital motion, that is, each time a power tool is used, each strut repeatedly expands and contracts, and elastic deformation is repeated. Therefore, when each support column deteriorates due to long-term use of the power tool, in some cases, each support column is cracked, and as a result, maintenance such as replacement is required. In particular, when the ambient temperature is low, there are many uses in the field. Not only is the maintenance cycle shortened by accelerating the deterioration of each support column, but the operation of the base is also difficult because each support column is hardened and difficult to elastically deform. Problems such as an increase in resistance and a reduction in grinding ability may occur.

  An object of the present invention is to provide a power tool capable of preventing an increase in operating resistance of a base and extending a maintenance cycle of a support.

  The power tool of the present invention includes a main body having a drive source, a rotation shaft provided in the drive source, and a base that moves in a horizontal direction with respect to the main body as the rotation shaft rotates. A power tool for performing a grinding operation with an abrasive sheet held on the base, a support provided between the main body and the base, a space between the main body and one end of the support, and the base And the other end portion of the support column, the main body portion, the one end portion, the base and the other end portion are slidably brought into contact with each other, and the support column is attached to the main body portion and the base. An uneven engagement portion that restricts a horizontal shift of the support column with respect to the base portion and the base while allowing swinging.

  In the power tool of the present invention, the concave / convex engaging portion includes a spherical convex portion or a spherical concave portion provided in the main body portion and the base, and a spherical concave portion or a spherical convex portion provided in the one end portion and the other end portion, respectively. It is formed by these.

  The power tool of the present invention is characterized in that the radial dimension of the spherical convex part is set to a radial dimension smaller than the radial dimension of the spherical concave part.

  According to the power tool of the present invention, the main body and the one end and the base and the other end are swingably moved between the main body and the one end of the support and between the base and the other end of the support. The protrusions are elastic in the orbital motion of the base because they are provided with concave and convex engaging parts that restrict the horizontal displacement of the pillars relative to the main body part and the base while allowing the pillars to swing with respect to the main body part and the base. It is oscillated with almost no resistance without deformation. Therefore, the strut is not subjected to the stress (load) that is elastically deformed as before, so that the operating resistance of the base can be prevented from being increased, and the life of the strut can be extended and its maintenance cycle can be extended. . In this case, the struts are formed by forming the concave and convex engaging portions by spherical convex portions or spherical concave portions provided in the main body portion and the base, respectively, and spherical concave portions or spherical convex portions provided in the one end portion and the other end portion, respectively. It can be swung more smoothly. In addition, by setting the radial dimension of the spherical convex part to be smaller than the radial dimension of the spherical concave part, the main body part, the column, the base, and the column can be brought into point contact with each other, and as a result, the column can be shaken more smoothly. Can be moved.

It is a perspective view which shows the orbital sander which concerns on 1st Embodiment of this invention. It is the fragmentary sectional view which followed the longitudinal direction of the orbital sander seen from the arrow A direction of FIG. It is a fragmentary sectional view which expands and shows the broken-line circle B part of FIG. (A), (b) is operation | movement explanatory drawing explaining the operation state of a leg. It is a fragmentary sectional view corresponding to FIG. 3 which shows the leg which concerns on 2nd Embodiment, and its peripheral structure. It is the fragmentary sectional view corresponding to FIG. 3 which shows the leg which concerns on 3rd Embodiment, and its peripheral structure. It is the fragmentary sectional view corresponding to FIG. 3 which shows the leg which concerns on 4th Embodiment, and its peripheral structure.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

  1 is a perspective view showing the orbital sander according to the first embodiment of the present invention, FIG. 2 is a partial sectional view along the longitudinal direction of the orbital sander viewed from the direction of arrow A in FIG. 1, and FIG. FIG. 4A and FIG. 4B are operation explanatory views for explaining the operation state of the legs, respectively.

  As shown in FIGS. 1 and 2, the orbital sander 10 as a power tool includes a sander body 20 and a base 30. The sander body 20 includes a housing 21 that can be divided on the left and right sides (the back side and the near side in FIG. 1) along the longitudinal direction of the orbital sander 10, and the housing 21 is formed in a hollow shape by a resin material such as plastic. ing.

  The housing 21 includes a motor accommodating portion 21a and a grip portion 21b. A motor 22 as a drive source is accommodated in the motor accommodating portion 21a in a vertically placed state, and the orbital sander 10 is accommodated in the grip portion 21b. An operation switch 11 for turning on and off is provided. A stopper button 12 (see FIG. 1) is provided near the operation switch 11 in the grip portion 21b. Then, by pressing the stopper button 12 while the operation switch 11 is turned on, the operation switch 11 enters a continuous operation state where the operation switch 11 is not turned off.

  Here, in FIG. 2, in order to make the internal structure of the housing 21 easier to understand, electrical wiring for electrically connecting the operation switch 11 and the motor 22, a power cord 13, polishing paper 14, and a clip 15 (see FIG. 1). ) Etc. are omitted.

  A fan guide 23 formed in a predetermined shape by a resin material such as plastic is provided in the housing 21 near the base 30. The fan guide 23 is fixed inside the housing 21, and a rotating shaft 22 a extending in a direction directly below the motor 22 passes through a substantially central portion of the fan guide 23. The rotating shaft 22a of the motor 22 is rotatably supported by a first radial bearing B1 mounted on the fan guide 23, and the cooling shaft 22a is disposed on the tip side of the first radial bearing B1 along the axial direction of the rotating shaft 22a. The fan 24 is fixed so as to be integrally rotatable. Here, the sander main body 20 is formed by a housing 21 and a fan guide 23, and these housing 21 and fan guide 23 constitute a main body in the present invention.

  The cooling fan 24 is rotatably accommodated inside the fan guide 23 via a dust guide 25. The cooling fan 24 has a cooling function for cooling the motor 22 and grinding dust ( (Not shown). A plurality of cooling fins 24 a are provided on the motor 22 side of the cooling fan 24, and a plurality of dust collection fins 24 b are provided on the base 30 side of the cooling fan 24 so as to face the discharge port 25 a of the dust guide 25. It has been. Thereby, outside air can be sent to the motor 22 along with the rotation of the cooling fan 24, and grinding waste can be sent to the inside of the dust bag 26 (see FIG. 1) via the discharge port 25a. Here, the dust collection bag 26 is formed of a cloth or the like having a degree of mesh that allows air to pass but does not allow grinding dust to pass.

  An eccentric piece 27 is fixed via a fastening screw S further to the front end side than the cooling fan 24 along the axial direction of the rotating shaft 22a. The eccentric piece 27 performs an orbital motion (eccentric circular motion) about the shaft center C2 at a position offset (offset) by about 1.0 mm with respect to the shaft center C1 of the rotating shaft 22a. An inner side of the second radial bearing B <b> 2 is attached to the piece body 27 a that forms the piece 27. Further, a cylindrical portion 31d provided integrally with a base plate 31 forming the base 30 is fixed to the outside of the second radial bearing B2, so that the orbital motion of the eccentric piece 27 accompanying the rotation of the rotary shaft 22a. Accordingly, the base 30 also performs an orbital motion via the second radial bearing B2. That is, the base 30 moves in a horizontal direction with respect to the housing 21 and the fan guide 23 by the operation of the eccentric piece 27.

  A weight 27b is partially provided integrally around the frame body 27a, thereby canceling (cancelling) horizontal vibrations associated with the orbital motion of the base 30. Specifically, for example, as shown in FIG. 2, when the base 30 moves to the right side in the figure, the weight 27b moves to the left side in the figure. Thus, by canceling the vibration in the horizontal direction during the operation of the orbital sander 10, the grip portion 21b gripped by the operator is prevented from moving in the horizontal direction.

  The base 30 is composed of a base plate 31 made of an aluminum material and a sponge-like pad 32 made of a rubber material. The pad 32 is provided with polishing paper 14 (see FIG. 1) as an abrasive sheet. In order to attach the polishing paper 14 to the pad 32, both end portions of the polishing paper 14 along the longitudinal direction of the orbital sander 10 are folded back to the base plate 31 side and pressed by the clips 15 attached to the base plate 31. . Here, a hole is also made in the polishing paper 14 in accordance with a dust collection hole (not shown) formed in the base plate 31 and the pad 32. Thereby, the grinding waste generated during the grinding operation is collected in the dust collection bag 26 through the hole provided in the polishing paper 14, the dust collection hole, and the dust guide 25 (discharge port 25a).

  A total of four legs (supports) 40 are provided between the fan guide 23 that forms the sander body 20 and the base plate 31 that forms the base 30. Although only two are shown in FIG. 2, each leg 40 is formed in a substantially cylindrical shape by an elastic material such as rubber, and extends along the horizontal direction of the fan guide 23 and the base plate 31 with the rotation shaft 22 a of the motor 22 interposed therebetween. It is arrange | positioned by the predetermined space | interval in front and rear, right and left. Here, since each leg 40 and these peripheral structures are all the same, hereinafter, one leg 40 and its peripheral structure will be described in detail with reference to FIG.

  As shown in FIG. 3, a first uneven engagement portion (uneven engagement portion) 50 is provided between the base side surface 23 a of the fan guide 23 and one end portion 40 a (upper side in the drawing) of the leg 40. Yes. The first concavo-convex engaging portion 50 includes a columnar member 51 that is integrally provided so as to extend in the axial direction of the rotation shaft 22a from the base side surface 23a toward the base plate 31, and the other end portion from the one end portion 40a of the leg 40 It is formed from the spherical recessed part 52 formed so that it may become depressed toward 40b. A spherical convex portion 51 a is integrally provided on the distal end side of the cylindrical member 51, and the spherical convex portion 51 a comes into contact with the spherical concave portion 52. Thereby, the swing of the leg 40 with respect to the fan guide 23 is allowed, and the axial shift of the leg 40 with respect to the fan guide 23, that is, the relative movement (shift) of the leg 40 with respect to the fan guide 23 in the horizontal direction is restricted.

  The radial dimension R1 of the spherical convex portion 51a is set to be slightly smaller than the radial dimension R2 of the spherical concave portion 52 (R1 <R2). Thus, the tip of the spherical convex portion 51a and the bottom of the spherical concave portion 52 are brought into point contact. In this manner, the spherical protrusion 51a and the spherical recess 52 are brought into point contact so that the leg 40 can smoothly swing without substantial resistance during the orbital movement of the base 30. Here, the height dimension of the columnar member 51 including the spherical convex portion 51 a is set to be larger than the depth dimension of the spherical concave portion 52. This prevents the contact between the one end 40a of the leg 40 and the base side surface 23a during the swinging motion of the leg 40 relative to the fan guide 23, so that the base 30 can smoothly perform an orbital motion.

  An annular first surrounding wall 23 b is integrally provided around the cylindrical member 51 of the fan guide 23 so as to surround the cylindrical member 51. Inside the first enclosure wall 23b, one end 40a side along the longitudinal direction of the leg 40 is accommodated in a non-contact state, and the height dimension of the first enclosure wall 23b from the base side surface 23a is h1. Yes. Thus, by setting the height dimension of the first surrounding wall 23b to h1, substantially 1/3 along the longitudinal direction of the leg 40 is covered, so that the leg 40 is greatly elastically deformed for some reason. Even if there is a case, the first enclosure wall 23b is prevented from jumping out.

  A tapered surface 23c is formed on the radially inner side of the first surrounding wall 23b so that the first surrounding wall 23b gradually becomes thinner toward the tip side (the lower side in the figure). The inclination angle of the tapered surface 23c is α °, and this inclination angle α ° is set to be the maximum inclination angle of the leg 40 when the leg 40 swings. Thereby, at the time of the assembly of the orbital sander 10, the one end portion 40a side of the leg 40 is easily accommodated in the first surrounding wall 23b. Further, during the swinging motion of the leg 40, the leg 40 and the first surrounding wall 23b are prevented from coming into contact with each other, so that the base 30 can smoothly perform an orbital motion (see FIG. 4).

  Between the fan guide side surface 31a of the base plate 31 and the other end portion 40b (lower side in the drawing) of the leg 40, a second uneven engagement portion (uneven engagement portion) 60 is provided. The second concavo-convex engaging portion 60 includes a columnar member 61 that is integrally provided so as to extend in the axial direction of the rotation shaft 22a from the fan guide side surface 31a toward the fan guide 23, and one end from the other end portion 40b of the leg 40. It is formed from the spherical recessed part 62 formed so that it might become depressed toward the part 40a. A spherical convex portion 61 a is integrally provided on the distal end side of the cylindrical member 61, and the spherical convex portion 61 a comes into contact with the spherical concave portion 62. Thereby, the swing of the leg 40 with respect to the base plate 31 is allowed, and the axial displacement of the leg 40 with respect to the base plate 31, that is, the relative movement (displacement) of the leg 40 with respect to the base plate 31 in the horizontal direction is restricted.

  The radial dimension R1 of the spherical convex portion 61a is set to be slightly smaller than the radial dimension R2 of the spherical concave portion 62 (R1 <R2). Thereby, the tip of the spherical convex portion 61a and the bottom of the spherical concave portion 62 are brought into point contact. In this manner, the spherical protrusion 61a and the spherical recess 62 are brought into point contact so that the leg 40 can swing smoothly without substantial resistance during the orbital movement of the base 30. Here, the height dimension of the cylindrical member 61 including the spherical convex portion 61 a is set to be larger than the depth dimension of the spherical concave portion 62. This prevents the contact between the other end portion 40b of the leg 40 and the fan guide side surface 31a during the swinging motion of the leg 40 with respect to the base plate 31, so that the base 30 can smoothly perform an orbital motion. .

  An annular second surrounding wall 31 b is integrally provided around the columnar member 61 of the base plate 31 so as to surround the columnar member 61. The other end 40b side along the longitudinal direction of the leg 40 is accommodated in a non-contact state inside the second enclosure wall 31b, and the height dimension of the second enclosure wall 31b from the fan guide side surface 31a is h2. (H2 <h1). In this way, by setting the height dimension of the second surrounding wall 31b to h2, approximately 1/4 along the longitudinal direction of the leg 40 is covered, so that the leg 40 is greatly elastically deformed for some reason. Even if there is a case, it does not jump out of the second surrounding wall 31b.

  Here, the height dimension h1 of the first surrounding wall 23b and the height dimension h2 of the second surrounding wall 31b can be arbitrarily set, for example, set so that the magnitude relationship is opposite to the above. May be. However, in the setting of the height dimensions h1 and h2, when the orbital sander 10 is operated, the space between the first enclosure wall 23b and the second enclosure wall 31b is able to absorb some blurring of the base 30 with respect to the fan guide 23. It is desirable to form a predetermined gap (substantially 1/4 dimension along the longitudinal direction of the leg 40).

  A tapered surface 31c is formed on the radially inner side of the second surrounding wall 31b so that the second surrounding wall 31b gradually becomes thinner toward the distal end side (the upper side in the figure). The inclination angle of the taper surface 31c is α °, and this inclination angle α ° is set to be the maximum inclination angle of the leg 40 when the leg 40 swings. Thereby, when the orbital sander 10 is assembled, the other end portion 40b side of the leg 40 is easily accommodated in the second surrounding wall 31b. Further, during the swinging motion of the leg 40, the leg 40 and the second surrounding wall 31b are prevented from coming into contact with each other, so that the base 30 can smoothly perform an orbital motion (see FIG. 4).

  Next, the operation of the orbital sander 10 formed as described above, particularly the swinging operation of the leg 40 during the orbital movement of the base 30, will be described in detail with reference to the drawings.

  First, as shown in FIG. 2, when the operator holds the grip portion 21 b of the orbital sander 10 and turns on the operation switch 11 under this state, a drive current is supplied to the motor 22. Then, the rotating shaft 22a rotates around the axis center C1, and accordingly, the eccentric piece 27 performs an orbital motion around the axis center C2. Thereby, the base 30 (base plate 31) also performs orbital movement via the second radial bearing B2, and the polishing paper 14 (see FIG. 1) attached to the pad 32 also performs orbital movement. Thereafter, by pressing the abrasive paper 14 against the surface of wood or the like, the portion can be efficiently ground and smoothed.

  At this time, as indicated by arrows SW1 and SW2 in FIGS. 4 (a) and 4 (b), the base 30 performs an orbital motion with respect to the fan guide 23. Accordingly, the leg 40 has a maximum inclination angle α ° (FIG. In the range of 3), swinging motion is performed so as to turn with respect to the cylindrical members 51 and 61. Here, since it is a plan view in FIG. 4, only the swinging motion of the leg 40 in the left-right direction (arrows SW1 and SW2) in the drawing is shown, but the leg 40 actually swings in the depth direction in the drawing. It comes to move.

  In the swinging motion of the leg 40, the leg 40 is made of rubber, and further, the leg 40 is brought into early contact with the plastic cylindrical member 51 and the aluminum cylindrical member 61 without elastic deformation. Therefore, the operating resistance of the orbital sander 10 is not increased. Therefore, the life of the leg 40 is extended as compared with the conventional case, and the maintenance of the orbital sander 10 is only required to periodically grease up (lubricate) the first uneven engagement portion 50 and the second uneven engagement portion 60. . Furthermore, since the leg 40 is made of rubber, the operating noise of the orbital sander 10 can be reduced while absorbing the dimensional error of the parts forming the orbital sander 10. However, if the part can be molded with such an accuracy that hardly causes a dimensional error, the leg 40 is not made of rubber, but can be formed of, for example, hard plastic or aluminum (high hardness member).

  As described above in detail, according to the orbital sander 10 according to the first embodiment, between the fan guide 23 and one end 40a of the leg 40 and between the base plate 31 and the other end 40b of the leg 40. The fan guide 23 and the one end 40a and the base plate 31 and the other end 40b are brought into contact with each other so as to be swingable, and the fan guide 23 and the base are allowed to swing while allowing the leg 40 to swing relative to the fan guide 23 and the base plate 31. A first concavo-convex engaging portion 50 and a second concavo-convex engaging portion 60 for restricting the horizontal displacement of the leg 40 with respect to the plate 31 were provided. As a result, during the orbital movement of the base 30, the leg 40 can swing without substantial resistance without being elastically deformed. Accordingly, the leg 40 is not subjected to a stress (load) that is elastically deformed as before, so that the operating resistance of the base 30 can be prevented from being increased, and the life of the leg 40 is extended to extend its maintenance cycle. be able to.

  In addition, according to the orbital sander 10 according to the first embodiment, the first concavo-convex engaging portion 50 and the second concavo-convex engaging portion 60 are provided with spherical convex portions 51a and 61a provided on the fan guide 23 and the base plate 31, respectively. And spherical recesses 52 and 62 provided in the one end 40a and the other end 40b, respectively. Further, the radial dimension R1 of the spherical convex portions 51a and 61a is set to a radius dimension (R1 <R2) smaller than the radial dimension R2 of the spherical concave portions 52 and 62. Therefore, the fan guide 23 and the leg 40 and the base plate 31 and the leg 40 can be brought into point contact with each other, and the leg 40 can be smoothly swung.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the part which has the same function as 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted. FIG. 5 is a partial cross-sectional view corresponding to FIG. 3 showing the leg and the peripheral structure according to the second embodiment.

  As shown in FIG. 5, the orbital sander (power tool) 70 according to the second embodiment is different in the leg and its peripheral structure from the first embodiment. Specifically, the first concave-convex engaging portion (concave-concave engaging portion) 80 of the orbital sander 70 includes a steel ball 81 having a radius R3 and a spherical ball having a radius R3 provided at one end 100a of the leg (post) 100. The recess 82 is formed. Further, the second uneven engagement portion (uneven engagement portion) 90 of the orbital sander 70 is formed from a steel ball 91 having a radius R3 and a spherical recess 92 having a radius R3 provided on the other end 100b of the leg 100. Has been.

  Here, each steel ball 81,91 comprises the spherical convex part in this invention, and each steel ball 81,91 is the engagement recessed part 71b formed in the base side surface 71a of the fan guide (main-body part) 71, respectively. The base plate 72 is mounted on an engagement recess 72b formed on the fan guide side surface 72a.

  Approximately half of each steel ball 81, 91 protrudes toward the leg 100, and enters each spherical recess 82, 92 of the leg 100 so as to be in sliding contact therewith. In addition, the depth dimension of each spherical recessed part 82 and 92 is set to the dimension smaller than the radial dimension R3 of each steel ball 81,91. This prevents the one end portion 100a from contacting the base side surface 71a and the other end portion 100b from the fan guide side surface 72a during the swinging motion of the leg 100.

  Unlike the first embodiment, the first concavo-convex engaging portion 80 and the second concavo-convex engaging portion 90 are abutted (slidably contacted) with each other on a spherical surface having the same radius R3 so as to be swingable. Therefore, as compared with the first embodiment, the play of the leg 100 can be further suppressed. However, in order to prevent wear of the leg 100 and realize a smooth orbital motion of the base 30, it is desirable to apply sufficient grease to the sliding contact portion.

  The orbital sander 70 according to the second embodiment includes an annular first surrounding wall 71c that protrudes from the base side surface 71a of the fan guide 71 with a height dimension h3, and further has a height from the fan guide side surface 72a of the base plate 72. An annular second surrounding wall 72c protruding with a dimension h4 is provided (h4 <h3). However, the height dimensions h3 and h4 of the first enclosure wall 71c and the second enclosure wall 72c can be arbitrarily set as in the first embodiment (see FIG. 3).

  An annular gap G1 larger than that of the first embodiment is formed between the first enclosure wall 71c and the second enclosure wall 72c and the leg 100. Thereby, even if the leg 100 swings and reaches the maximum inclination angle α °, the first enclosure wall 71c and the second enclosure wall 72c do not come into contact with the leg 100. Therefore, the taper surfaces on the radially inner side of the first enclosure wall and the second enclosure wall provided in the first embodiment are omitted.

  As described above in detail, the orbital sander 70 according to the second embodiment also has the same effects as those of the first embodiment except for the effects of “point contact” in the first embodiment described above. be able to. In addition, in the second embodiment, since each steel ball 81, 91 is used for the first uneven engagement portion 80 and the second uneven engagement portion 90, each steel ball 81, 91 is JIS standard or the like. Thus, the cost reduction of the orbital sander 70 can be realized.

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the part which has the same function as 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted. FIG. 6 is a partial cross-sectional view corresponding to FIG. 3 showing the leg and the peripheral structure according to the third embodiment.

  As shown in FIG. 6, the orbital sander (power tool) 110 according to the third embodiment differs from the first embodiment in the leg and the peripheral structure. Specifically, the concavo-convex relationship between the first concavo-convex engaging portion (concavo-convex engaging portion) 120 and the second concavo-convex engaging portion (concavo-convex engaging portion) 130 is opposite to that in the first embodiment. It has become. That is, the spherical protrusions 121 and 131 having a radius R4 are integrally formed on the one end 140a and the other end 140b of the leg (support) 140 so as to protrude toward the fan guide (main body) 111 and the base plate 112, respectively. Is provided. Here, in the third embodiment, the leg 140 is made of aluminum.

  The base side surface 111a of the fan guide 111 is provided with a spherical concave portion 122 having a radius R4 in which the spherical convex portion 121 enters and is in sliding contact. Here, the first concavo-convex engaging portion 120 is formed by the spherical convex portion 121 and the spherical concave portion 122. On the other hand, a flexible rubber pedestal 113 is placed on the fan guide side surface 112a of the base plate 112, and the spherical guide 131 enters and slides into the fan guide side surface 113a of the rubber pedestal 113 with a radial dimension R4. A spherical recess 132 is provided. Here, the second concavo-convex engaging portion 130 is formed by the spherical convex portion 131 and the spherical concave portion 132. If the part can be molded with an accuracy that hardly causes a dimensional error, the rubber pedestal 113 is omitted, a spherical concave portion is formed in the base plate 112, and the spherical convex portion 131 is inserted into the spherical concave portion for sliding. You may make it contact.

  Here, the one end portion 140a and the base side surface 111a of the leg 140, and the other end portion 140b of the leg 140 and the fan guide side surface 113a of the rubber pedestal 113 are not in contact with each other during the swinging motion of the leg 140. In the first concavo-convex engaging portion 120 and the second concavo-convex engaging portion 130, the spherical surfaces having the same radius R4 are in contact with each other in a swingable manner (sliding contact), so as in the second embodiment, The backlash of the leg 140 can be further suppressed. However, in order to prevent wear of the rubber pedestal 113 and the fan guide 111 and realize a smooth orbital movement of the base 30, it is desirable to apply sufficient grease to the sliding contact portion.

  The orbital sander 110 according to the third embodiment includes an annular first surrounding wall 111b protruding from the base side surface 111a of the fan guide 111 with a height dimension h5. The base plate 112 of the orbital sander 110 is provided with an annular second surrounding wall 112b that protrudes from the fan guide side surface 113a of the rubber pedestal 113 with a height dimension h6 (h6 <h5). However, the height dimensions h5 and h6 of the first enclosure wall 111b and the second enclosure wall 112b can be arbitrarily set as in the first embodiment (see FIG. 3).

  As in the second embodiment, an annular gap G2 larger than that in the first embodiment is formed between the first enclosure wall 111b and the second enclosure wall 112b and the leg 140. Thereby, even if the leg 140 swings and reaches the maximum inclination angle α °, the first enclosure wall 111b and the second enclosure wall 112b do not come into contact with the leg 140. Therefore, also in the third embodiment, as in the second embodiment, the radially inner tapered surfaces of the first enclosure wall and the second enclosure wall are omitted.

  As described above in detail, the orbital sander 110 according to the third embodiment also has the same effects as those of the first embodiment except for the effects of “point contact” in the first embodiment described above. be able to.

  Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the part which has the same function as 1st Embodiment mentioned above, and the detailed description is abbreviate | omitted. FIG. 7 is a partial cross-sectional view corresponding to FIG. 3 showing the leg and the peripheral structure thereof according to the fourth embodiment.

  As shown in FIG. 7, the orbital sander (power tool) 150 according to the fourth embodiment is different in the leg and its peripheral structure from the first embodiment. Specifically, the first uneven engagement portion (uneven engagement portion) 160 of the orbital sander 150 includes a conical protrusion 161 having an angle of β ° provided on the fan guide (main body portion) 151 and a leg (support). It is formed from a conical recess 162 having an angle γ ° (γ °> β °) provided at one end 170a of 170. Further, the second uneven engagement portion (uneven engagement portion) 180 of the orbital sander 150 is provided at the conical convex portion 181 having an angle of β ° provided on the base plate 152 and the other end portion 170 b of the leg 170. A conical recess 182 having an angle of γ ° is formed.

  The height dimension of the conical convex portion 161 from the base side surface 151 a of the fan guide 151 is set to be larger than the depth dimension of the conical concave portion 162 from the one end portion 170 a of the leg 170. In addition, the height dimension of the conical protrusion 181 from the fan guide side surface 152 a of the base plate 152 is set to be larger than the depth dimension of the conical recess 182 from the other end 170 b of the leg 170. This prevents the one end 170a and the base side surface 151a from coming into contact with the other end 170b and the fan guide side surface 152a during the swinging motion of the leg 170.

  However, the leg 170 is not limited to rubber, and may be made of hard plastic or aluminum having higher hardness than rubber. In this case, a rubber pedestal may be arranged on the base plate 152 in the same manner as the orbital sander 110 (see FIG. 6) of the third embodiment in order to reduce the operating noise associated with the swinging motion of the leg 170. good. In this case, the conical convex portion may be provided integrally with the rubber pedestal, or the conical convex portion made of aluminum or the like may be placed on the rubber pedestal.

  As described above in detail, also in the orbital sander 150 according to the fourth embodiment, the tip portions of the conical convex portions 161 and 181 and the bottom portions of the conical concave portions 162 and 182 are substantially point-contacted. The same effects as those of the first embodiment can be achieved.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. In each of the above-described embodiments, the fan guides 23, 71, 111, 151 are provided with the first surrounding walls 23b, 71c, 111b, and the base plates 31, 72, 112, 152 are provided with the second surrounding walls 31b, 72c, 112b. Although what was provided was shown, this invention is not limited to this. For example, if the hardness of the leg can be increased, the leg does not elastically deform and jump out of the surrounding walls, and the surrounding walls can be omitted. In this case, it becomes possible to simplify the structure of the fan guide and the base plate, thereby further reducing the manufacturing cost of the orbital sander.

DESCRIPTION OF SYMBOLS 10 ... Orbital sander (power tool), 11 ... Operation switch, 12 ... Stopper button, 13 ... Power cord, 14 ... Polishing paper (polishing sheet), 15 ... Clip, 20 ... Sander main body, 21 ... Housing (main body part), 21a: Motor housing portion, 21b: Grip portion, 22: Motor (drive source), 22a ... Rotating shaft, 23 ... Fan guide (main body portion), 23a ... Base side surface, 23b ... First enclosure wall, 23c ... Tapered surface, 24 ... Cooling fan, 24a ... Cooling fin, 24b ... Dust collection fin, 25 ... Dust guide, 25a ... Discharge port, 26 ... Dust collection bag, 27 ... Eccentric piece, 27a ... Frame body, 27b ... Weight, 30 ... Base, 31 ... Base plate (base), 31a ... Side surface of fan guide, 31b ... Second enclosure wall, 31c ... Tapered surface, 31d ... Cylindrical portion, 32 ... Pad (base), 40 ... L (Post), 40a ... one end, 40b ... the other end, 50 ... first concave / convex engaging portion (concave / concave engaging portion), 51 ... cylindrical member, 51a ... spherical convex, 52 ... spherical concave, 60 ... second. Uneven engaging portion (uneven engaging portion), 61 ... cylindrical member, 61a ... spherical convex portion, 62 ... spherical concave portion, 70 ... orbital sander (power tool), 71 ... fan guide (main body portion), 71a ... side surface of base, 71b ... engagement recess, 71c ... first enclosure wall, 72 ... base plate (base), 72a ... fan guide side surface, 72b ... engagement depression, 72c ... second enclosure wall, 80 ... first uneven engagement part (unevenness) Engagement part), 81 ... steel ball (spherical convex part), 82 ... spherical concave part, 90 ... second concave / convex engaging part (concave convex part), 91 ... steel ball (spherical convex part), 92 ... spherical concave part, DESCRIPTION OF SYMBOLS 100 ... Leg (pillar), 100a ... One end part, 100b ... Other end part, 110 ... Orbital sander Power tool), 111 ... Fan guide (main body), 111a ... Base side surface, 111b ... First enclosure wall, 112 ... Base plate (base), 112a ... Fan guide side surface, 112b ... Second enclosure wall, 113 ... Rubber base , 113a... Fan guide side surface, 120... First uneven engagement portion (uneven engagement portion), 121 .. spherical protrusion, 122 .. spherical recess, 130 .. second uneven engagement portion (uneven engagement portion), 131. Spherical convex part, 132 ... spherical concave part, 140 ... leg (support), 140a ... one end part, 140b ... other end part, 150 ... orbital sander (power tool), 151 ... fan guide (main body part), 151a ... side surface of base, 152 ... Base plate (base), 152a ... Fan guide side surface, 161 ... Conical convex part, 162 ... Conical concave part, 170 ... Leg (post), 170a ... One end part, 170b ... Other end part, 1 81 ... Conical convex portion, 182 ... Conical concave portion, B1 ... First radial bearing, B2 ... Second radial bearing, G1, G2 ... Annular gap, S ... Fastening screw

Claims (3)

A main body having a drive source, a rotation shaft provided in the drive source, and a base that moves in a horizontal direction with respect to the main body in accordance with the rotation of the rotation shaft, and is held by the base In power tools that perform grinding work with the polished abrasive sheet,
A support provided between the main body and the base;
Provided between the main body and one end of the support and between the base and the other end of the support, respectively, and the main body, the one end, and the base and the other end are swingable with respect to each other. A concavo-convex engaging portion that regulates a horizontal displacement of the column with respect to the main body and the base, while allowing the column to swing with respect to the main body and the base,
A power tool characterized by comprising:   The concave-convex engaging portion is formed by a spherical convex portion or a spherical concave portion provided in the main body portion and the base, respectively, and a spherical concave portion or a spherical convex portion provided in the one end portion and the other end portion, respectively. The power tool according to claim 1, wherein   The power tool according to claim 2, wherein a radial dimension of the spherical convex portion is set to be smaller than a radial dimension of the spherical concave portion.

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