JP2010158608A - Bit cleaning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bit cleaning device capable of efficiently removing dust with high precision. <P>SOLUTION: A void 41 forms the shape of a tip of a driver bit 18. The void 41 is covered with a cloth sheet 32. Accordingly, when the tip is received into the void 41 along the axial center, the cloth sheet 32 is held between the outer wall surface of the tip and the inner wall surface of the void 41. In accordance with the movement of the driver bit 18 along the axial center, the tip is pushed against the cloth sheet 32 in the void 41. The cloth sheet 32 is crushed. The cloth sheet 32 rubs off the fine dust from the outer wall surface of the tip. Thus, the cloth sheet 32 can efficiently remove the dust with high precision from the outer wall surface of the tip. A cleaning operation is efficiently performed. As the result, the attachment of the dust to the tip of the driver bit 18 is avoided. The movement of the dust from the tip to, for example, the screw head of a screw is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bit cleaning device that cleans the tip of a driver bit used for screw tightening.

  For example, in a hard disk drive (HDD), a magnetic disk is mounted on a hub of a spindle motor. The clamp is fixed to the hub with screws. When fastening the screw, the tip of the driver bit is pressed against the recess of the screw head. The screw shaft is screwed into the hub based on the rotation of the driver bit. The tip of the driver bit is withdrawn from the recess. Thereafter, the tip of the driver bit is cleaned. Minute dust such as metal abrasion powder adhering to the tip of the driver bit is removed. Such cleaning is performed every time the screw is tightened. Dropping of garbage in the HDD is avoided.

Japanese Patent Laid-Open No. 10-337512 JP-A-4-367242 Japanese Patent No. 2984601 JP 2004-134603 A

  In conventional cleaning, for example, an adhesive surface of an adhesive tape is pressed against the tip of a driver bit. However, the adhesive tape may not be able to contact the groove of the driver bit, for example. Garbage remains in the groove. On the other hand, for cleaning, for example, a brush is rubbed against the driver bit. However, the brush may only move small debris along the surface of the driver bit. Dust remains on the surface of the driver bit. Thus, if dust remaining in the HDD adheres to the surface of the magnetic disk, for example, a head crash occurs.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a bit cleaning device capable of efficiently removing dust with high accuracy.

  In order to achieve the above object, one form of the disclosed bit cleaning device includes a driving mechanism that movably holds the driver bit along an axis of the driver bit that defines a tip portion of a predetermined shape, and the tip. A female die that defines a gap that can receive the tip portion along the axis while imitating the shape of the portion, and a cloth sheet that is disposed on the female die and covers the gap.

  According to such a bit cleaning device, the gap is shaped like the tip of the driver bit. A cloth sheet covers the gap. Therefore, when the tip portion is received in the gap along the axis, the cloth sheet is sandwiched between the outer wall surface of the tip portion and the inner wall surface of the gap. Based on the movement of the driver bit along the axis, the tip is pressed against the fabric sheet in the gap. The cloth sheet is crushed. The cloth sheet scrapes minute dust from the outer wall surface at the tip. Thus, the cloth sheet can efficiently remove dust from the outer wall surface of the tip portion with high accuracy. Cleaning work is carried out efficiently. As a result, dust is prevented from adhering to the tip of the driver bit. The movement of dust from the tip portion to, for example, the screw head of the screw is prevented.

  As described above, according to the disclosed bit cleaning device, dust can be efficiently removed with high accuracy.

It is a perspective view which shows roughly the external appearance of the screw fastening apparatus which concerns on one specific example. It is a perspective view showing roughly the appearance of the bit cleaning device concerning a 1st embodiment of the present invention. It is a disassembled perspective view which shows roughly the internal structure of the bit cleaning apparatus which concerns on 1st Embodiment of this invention. It is a partial see-through | perspective perspective view which shows the structure of a female type | mold schematically. It is a side view which shows roughly the structure of the driver bit which concerns on one specific example. It is a front view which shows roughly the structure of the driver bit which concerns on one specific example. It is a top view which shows roughly the structure of the space | gap which concerns on one specific example. It is sectional drawing which shows roughly the structure of the space | gap which concerns on one specific example. It is a block diagram which shows the control system of a screw fastening apparatus. It is a perspective view which shows arrangement | positioning at the time of screw fastening operation | work. It is a perspective view which shows arrangement | positioning at the time of a cleaning operation | work. It is sectional drawing which shows a mode that a space | gap is positioned on the axial center of a driver bit roughly. It is sectional drawing which shows a mode that the front-end | tip part of a driver bit is pushed into a space | gap along an axial center. It is sectional drawing which shows a mode that the front-end | tip part of a driver bit is pressed in a space | gap. FIG. 15 is a cross-sectional view taken along line 15-15 of FIG. FIG. 16 is a cross-sectional view schematically showing a state in which the driver bit rotates about the axis corresponding to FIG. 15. FIG. 16 is a cross-sectional view schematically showing a state in which the driver bit rotates about the axis corresponding to FIG. 15. It is sectional drawing which shows schematically the structure of the bit cleaning apparatus which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows a mode that a washing | cleaning liquid is supplied in a space | gap. It is sectional drawing which shows a mode that the front-end | tip part of a driver bit is pressed in a space | gap. It is sectional drawing which shows a mode that a washing | cleaning liquid is discharged | emitted from the space | gap. It is sectional drawing which shows a mode that the front-end | tip part of a driver bit is pulled out from the space | gap. It is a side view which shows roughly the structure of the driver bit which concerns on another specific example. It is a front view which shows roughly the structure of the driver bit which concerns on another specific example. It is a top view which shows roughly the structure of the space | gap which concerns on another specific example. It is sectional drawing which shows roughly the structure of the space | gap which concerns on another specific example.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a screw fastening device 11 according to a specific example. The screw fastening device 11 includes a stage 12. The stage 12 is defined with a support surface 13 extending along an arbitrary horizontal plane. A driving mechanism, that is, a robot 14 is fixed to the stage 12. The robot 14 includes a support column 15 that stands upright from the support surface 13 of the stage 12 in the vertical direction. An electric driver 16 is attached to the column 15. The electric driver 16 includes a support body 17. The support 17 is held by the support column 15 so as to be movable in the vertical direction, that is, the z-axis direction. A driver bit 18 is detachably attached to the lower end of the support 17. The axis of the driver bit 18 is defined in the z-axis direction. The support 17 holds the driver bit 18 so as to be rotatable around the axis of the driver bit 18.

  A bit cleaning device 21 is combined with the robot 14. The bit cleaning device 21 includes a housing 22. The housing 22 can move in the y-axis direction parallel to the support surface 13. The y axis is orthogonal to the z axis in a vertical plane orthogonal to the horizontal plane. An opening 23 is formed on the upper surface of the housing 22 parallel to the support surface 13. In FIG. 1, the housing 22 is positioned at the retracted position. In the retracted position, the housing 22 is disposed outside the moving path of the driver bit 18 defined in the z-axis direction. As will be described later, when the housing 22 moves in the y-axis direction, the housing 22 is positioned at the operating position. The housing 22 is disposed between the driver bit 18 and the support surface 13. At this time, the opening 23 of the housing 22 is arranged on the moving path of the driver bit 18. Thus, the casing 22 can move between the retracted position and the operating position. For such movement, the casing 22 is connected to a casing moving mechanism described later.

  FIG. 2 schematically shows the appearance of the bit cleaning device 21 according to the first embodiment of the present invention. The housing 22 includes a cover 24. The aforementioned opening 23 is formed on the upper surface of the cover 24. An outflow port 25 is formed on the rear surface of the housing 22, for example. The outlet 25 is connected to a vacuum pump (not shown) described later. Air is sucked out of the housing space of the housing 22 toward the outlet 25 by the action of the vacuum pump. As a result, a negative pressure is always generated in the housing space of the housing 22. Referring also to FIG. 3, the housing 22 includes a base 26 that is fitted to the cover 24. The base 26 extends along a vertical plane. The cover 24 covers the base 26. A housing space for the housing 22 is defined between the cover 24 and the base 26.

  A tape transport mechanism 27 is incorporated in the accommodation space. The tape transport mechanism 27 includes a delivery reel 28 and a take-up reel 29 that are rotatably attached to the side surface of the base 26. A plurality of rollers 31 are arranged between the delivery reel 28 and the take-up reel 29. The rotation axes of the delivery reel 28, the take-up reel 29 and the roller 31 are defined in the x-axis direction. The x axis is orthogonal to the y axis in the horizontal plane. A tape-like cloth sheet 32 is supported on the roller 31 between the delivery reel 28 and the take-up reel 29. An electric motor 33 is connected to the take-up reel 29. The cloth sheet 32 is conveyed from the delivery reel 28 to the take-up reel 29 based on the drive of the electric motor 33. For the cloth sheet 32, for example, a woven or non-woven fabric of resin fiber such as polyester fiber is used. The resin fiber is formed to be extremely fine, for example, about 2 μm in diameter.

  A remaining amount detection sensor 34 is associated with the delivery reel 28. The remaining amount detection sensor 34 includes a lever 36 that is rotatably supported at a base end by a support shaft 35 extending in the x-axis direction. The support shaft 35 is disposed above the delivery reel 28. Thus, the tip of the lever 36 is received at a predetermined rotation angle by the cloth sheet 32 wound around the delivery reel 28. As a result, the rotation angle of the lever 36 changes around the support shaft 35 according to the amount of the cloth sheet 32 wound around the delivery reel 28, that is, the remaining amount. The change in the rotation angle corresponds to the remaining amount of the cloth sheet 32. Thus, the remaining amount of the cloth sheet 32 is detected. On the other hand, a pulse detection sensor 37 is connected to the roller 31 adjacent to the delivery reel 28. The pulse detection sensor 37 detects a pulse according to the rotation angle of the roller 31. The feed pitch of the cloth sheet 32 is specified according to the number of pulses. Here, since the number of pulses is always set to be constant, the feed pitch of the cloth sheet 32 is always set to be constant.

  A receiving base 38 fixed to the base 26 is accommodated in the accommodating space. The cradle 38 faces the opening 23 of the cover 24. The cradle 38 is disposed between a pair of rollers 31 and 31 disposed along a horizontal plane. As a result, the cloth sheet 32 is disposed on the cradle 38. The cloth sheet 32 spreads along the horizontal plane on the cradle 38. Referring also to FIG. 4, a female die 39 is fixed on the cradle 38. Here, the female die 39 is formed in a cylindrical shape that defines the central axis in the z-axis direction. The rotation of the female die 39 is restricted around the central axis. The top surface of the female die 39 extends along a horizontal plane. The female die 39 receives the cloth sheet 32 at the top surface. A predetermined gap, that is, a recess 41 is formed on the top surface of the female die 39. The recess 41 is formed along the central axis of the female die 39. The recess 41 represents the shape of the tip of the driver bit 18 described above. When the cloth sheet 32 is sent out based on the drive of the electric motor 33, the cloth sheet 32 is conveyed along the top surface of the female mold 39.

  As shown in FIG. 5, in the present embodiment, the tip end portion of the driver bit 18 is formed in, for example, a plus groove shape. Here, the diameter of the driver bit 18 is set to about 3 mm to 4 mm, for example. The tip portion tapers along the axis toward the tip. Referring also to FIG. 6, the tip portion includes four grooves 18a. A protruding wall 18b is formed between the grooves 18a adjacent to each other. The groove 18a and the protruding wall 18b extend to the tip along the axis. On the other hand, as shown in FIG. 7, the recess 41 of the female die 39 is shaped like a plus groove at the tip of the driver bit 18. The recess 41 is formed with four grooves 41 a for receiving the protruding wall 18 b of the driver bit 18. Referring also to FIG. 8, the recess 41 tapers toward the bottom. The dimension of the recess 41 is, for example, larger than the dimension of the tip. Thus, the recess 41 can receive the tip.

  As shown in FIG. 9, a robot controller 45 is connected to the robot 14. The robot controller 45 controls the operation of the robot 14 based on the supply of the control signal. As a result, the robot 14 moves the support body 17, that is, the electric driver 16, in the z-axis direction. Similarly, an electric driver controller 46 is connected to the electric driver 16. The electric driver controller 46 controls the operation of the electric driver 16 based on the supply of the control signal. As a result, the electric driver 16 rotates the driver bit 18 around the axis of the driver bit 18. A predetermined rotational torque is set when the driver bit 18 rotates.

  The bit cleaning device 21 includes a housing moving mechanism 47, an electric motor 33, and a vacuum pump 48. A cleaning device controller 49 is connected to the housing moving mechanism 47, the electric motor 33, and the vacuum pump 48. The cleaning device controller 49 controls operations of the housing moving mechanism 47, the electric motor 33, and the vacuum pump 48 based on the supply of the control signal. In response to receiving the control signal, the housing moving mechanism 47 moves the housing 22 in the y-axis direction between the retracted position and the operating position. In response to receiving the control signal, the electric motor 33 rotates the take-up reel 29 at a predetermined rotation angle. Similarly, the vacuum pump 48 sucks air out of the housing 22 in response to reception of the control signal.

  The cleaning device controller 49 is connected to the remaining amount detection sensor 34 and the pulse detection sensor 37 described above. The remaining amount detection sensor 34 outputs the rotation angle of the lever 36 to the cleaning device controller 49. The cleaning device controller 49 detects the remaining amount of the cloth sheet 32 in accordance with the output rotation angle. On the other hand, the pulse detection sensor 37 outputs the rotation angle of the roller 31 to the cleaning device controller 49. The cleaning device controller 49 detects the feed pitch of the cloth sheet 32 in accordance with the output rotation angle. The rotation angle of the electric motor 33 is determined according to the feed pitch thus detected. As a result, the cloth sheet 32 is fed from the delivery reel 28 toward the take-up reel 29 at a predetermined feed pitch.

  For example, a programmable logic controller (PLC) 51 is connected to the robot controller 45, the electric driver controller 46 and the cleaning device controller 49. The PLC 51 controls the operations of the robot controller 45, the electric driver controller 46, and the cleaning device controller 49 in accordance with a predetermined software program. Thus, the operation of the screw fastening device 11 is controlled. The software program may be stored in a non-volatile memory such as a flash memory (not shown) that is similarly incorporated in the screw tightening device 11.

  Now, assume that the screw tightening device 11 operates. As shown in FIG. 10, a base 55 for a hard disk drive (HDD) is disposed at a predetermined position on the support surface 13 of the stage 12. For example, a plurality of magnetic disks 56 are mounted on the spindle motor in the base 55. A clamp 57 is disposed on the magnetic disk 56. The bit cleaning device 21 is positioned at the retracted position. The electric driver 16 is positioned at the reference position. The reference position is specified by a position retracted outside the movement path of the housing 22. A screw (not shown) is supplied to the tip of the driver bit 18. Based on the control of the PLC 51, the electric driver 16 descends toward the support surface 13 along its axis. The screw is received in a screw hole formed in the hub of the spindle motor. The screw is screwed into the screw hole based on the rotation of the driver bit 18 around the axis. After screwing, the driver bit 18 is raised to the reference position along the axis.

  As shown in FIG. 11, the bit cleaning device 21 moves from the retracted position to the operating position based on the control of the PLC 51. The housing 22 is disposed between the driver bit 18 and the base 55. As shown in FIG. 12, the axis of the driver bit 18 coincides with the central axis of the female die 39. A predetermined tension is maintained on the cloth sheet 32 on the female die 39. The electric driver 16, that is, the driver bit 18, moves down along the axis. As shown in FIG. 13, the driver bit 18 pushes the cloth sheet 32 toward the recess 41 at the tip. The cloth sheet 32 bends into the recess 41. When the driver bit 18 is further lowered, the tip of the driver bit 18 is completely received in the recess 41 as shown in FIG. As shown in FIG. 15, the cloth sheet 32 is sandwiched between gaps formed between the outer wall surface of the tip and the inner wall surface of the recess 41. The cloth sheet 32 is in close contact with the outer wall surface of the tip.

  At this time, the driver bit 18 repeats ascending and descending reciprocation at a slight distance along the axis. Thus, the tip is pressed against the cloth sheet 32 in the recess 41 a plurality of times. Each time the driver bit 18 is pressed between the outer wall surface of the tip and the inner wall surface of the recess 41, the cloth sheet 32 is crushed. In this way, the cloth sheet 32 scrapes off minute dust such as wear powder from the outer wall surface of the tip. At the same time, when pressed into the recess 41, the driver bit 18 rotates clockwise and counterclockwise about the axial center by the gap between the outer wall surface of the tip and the inner wall surface of the recess 41. As a result, as shown in FIGS. 16 and 17, the cloth sheet 32 is pressed between the outer wall surface of the tip and the inner wall surface of the recess 41 every time it rotates. In this way, the fine dust adhering to the groove 18a at the tip is surely scraped off by the cloth sheet 32. Fine dust is held on the cloth sheet 32.

  The driver bit 18 rises to the reference position along the axis. Thereafter, the cloth sheet 32 is wound around the take-up reel 29 at a predetermined feed pitch based on the drive of the electric motor 33. On the female die 39, the cloth sheet 32 is fed at a predetermined feed pitch. Thus, a clean cloth sheet 32 is always arranged on the female mold 39. Since negative pressure is always generated in the housing 22, even if minute dust attached to the cloth sheet 32 falls into the housing 22, the dust is reliably discharged from the outlet 25. Thereafter, based on the control of the PLC 51, the bit cleaning device 21 is retracted from the operating position to the retracted position. Subsequently, the driver bit 18 descends from the reference position along the axis. As described above, the driver bit 18 is screwed based on the rotation around the axis. After the screwing operation is completed, the above-described cleaning operation is performed. Thus, the screw tightening operation and the cleaning operation are alternately repeated. When all screwing operations are completed, the base 55 is removed from the support surface 13.

  In the screw tightening device 11 as described above, the recess 41 is shaped like the tip of the driver bit 18. When the distal end is received by the recess 41 along the axis, the cloth sheet 32 is sandwiched between the outer wall surface of the distal end and the inner wall surface of the recess 41. The tip is pressed against the cloth sheet 32 in the recess 41 based on the movement of the driver bit 18 along the axis. Similarly, the tip portion is pressed against the cloth sheet 32 in the recess 41 based on the rotation of the driver bit 18 around the axis. Thus, the cloth sheet 32 is crushed. The cloth sheet 32 scrapes off dust from the outer wall surface at the tip. The cloth sheet 32 can efficiently remove dust from the outer wall surface of the tip portion with high accuracy. Cleaning work is carried out efficiently. As a result, the adhesion of dust to the tip of the driver bit 18 is avoided. The movement of dust from the tip to the screw head is prevented. Remaining garbage in the HDD is avoided.

  FIG. 18 schematically shows the structure of a bit cleaning device 21a according to the second embodiment of the present invention. A cleaning liquid supply mechanism 61 is incorporated in the bit cleaning device 21a. The cleaning liquid supply mechanism 61 is opposed to the surface of the cloth sheet 32 in the housing 22 between, for example, the delivery reel 28 and the female mold 39. That is, it is desirable that the cleaning liquid supply mechanism 61 is disposed as close as possible to the recess 41 on the upstream side of the cloth sheet 32 from the recess 41. The operation of the cleaning liquid supply mechanism 61 is controlled based on a cleaning device controller 49. The cleaning liquid supply mechanism 61 supplies a cleaning liquid 62 such as alcohol to the cloth sheet 32. The supply of the cleaning liquid 62 is performed every time the above-described cleaning operation is performed. In addition, the same reference numerals are assigned to the same configurations and structures as those of the bit cleaning device 21 described above.

  In such a bit cleaning device 21 a, the cleaning liquid supply mechanism 61 applies the cleaning liquid 62 toward the cloth sheet 32 when the housing 22 is disposed at the operating position. In this way, the cloth sheet 32 is immersed in alcohol. The cloth sheet 32 is fed at a predetermined feed pitch based on the drive of the electric motor 33. As a result, the cloth sheet 32 is disposed on the recess 41 in the region including the cleaning liquid 62. At this time, the tip of the driver bit 18 is pushed into the recess 41. The cloth sheet 32 is crushed. At this time, the cleaning liquid 62 contained in the cloth sheet 32 cleans the outer wall surface of the tip portion of the driver bit 18. The supply of the cleaning liquid 62 of the cleaning liquid supply mechanism 61 may be performed immediately before the cloth sheet 32 is fed.

  As shown in FIG. 19, the cleaning liquid supply mechanism 61 may be connected to the recess 41. In the female die 39, a supply path 63 for supplying the cleaning liquid 62 into the recess 41 and a discharge path 64 for discharging the cleaning liquid 62 accumulated in the recess 41 from the recess 41 are formed. The cleaning liquid supply mechanism 61 is connected to the supply path 63. The cleaning liquid supply mechanism 61 supplies the cleaning liquid 62 from the supply path 63 into the recess 41. The supply path 63 is connected to the inner wall surface of the recess 41, for example. The discharge path 64 is connected to the bottom surface of the recess 41, for example. When the cleaning liquid 62 is supplied from the supply path 63 into the recess 41, a stopper (not shown) may be disposed in the discharge path 64. In this way, a certain amount of cleaning liquid 62 is stored in the recess 41 for each cleaning operation. Similarly, the cleaning liquid 62 is discharged at every cleaning operation.

  As shown in FIG. 20, when the tip of the driver bit 18 is pressed into the recess 41, the cleaning liquid 62 penetrates into the cloth sheet 32 in the recess 41. At this time, the driver bit 18 operates in the same manner as described above. As a result, the cloth sheet 32 can reliably remove dust from the outer wall surface of the tip. Thereafter, as shown in FIG. 21, the stopper of the discharge path 64 is removed in a state where the tip end portion is received in the recess 41. As a result, the used cleaning liquid 62 is discharged from the recess 41 through the discharge path 64. The cleaning liquid 62 may be sucked from the recess 41 when discharging. When the cleaning liquid 62 is completely discharged from the discharge path 64, the driver bit 18 rises along the axis as shown in FIG. Thus, the driver bit 18 is positioned at the reference position. At the same time, the cloth sheet 32 is conveyed at a predetermined feed pitch. Thus, a clean cloth sheet 32 is always disposed on the recess 41. Since the cleaning liquid 62 is supplied every cleaning operation, the cleaning liquid 62 is always stored in the recess 41.

  As shown in FIG. 23, the driver bit 18 may be a Torx (TORX) groove-shaped driver bit, for example. The tip of the driver bit 18 is defined to have a uniform diameter from the base end to the tip. Referring also to FIG. 24, each driver bit 18 has six grooves 18a and protruding walls 18b. On the other hand, as shown in FIG. 25, the recess 41 has the shape of a Torx groove at the tip of the driver bit 18. Therefore, the recess 41 is formed with six grooves 41a for receiving the protruding wall 18b of the driver bit 18. Referring also to FIG. 26, the dimension of the recess 41 is formed, for example, slightly larger than the dimension of the tip. Thus, the recess 41 can receive the tip.

  14 Drive mechanism (robot), 18 Driver bit, 21, 21a Bit cleaning device, 27 Conveyance mechanism, 32 Cloth sheet, 39 Female mold, 41 Air gap (recess), 61 Supply mechanism, 62 Cleaning liquid, 63 Supply path, 64 Discharge path .

Claims (5)

A drive mechanism for holding the driver bit movably along the axis of the driver bit defining a tip of a predetermined shape;
A female mold that defines a gap capable of receiving the tip portion along the axis while imitating the shape of the tip portion;
A bit cleaning device comprising: a cloth sheet disposed on the female mold and covering the gap.   The bit cleaning device according to claim 1, wherein the driving mechanism holds the driver bit rotatably around the axis.   The bit cleaning device according to claim 1, further comprising a transport mechanism that transports the cloth sheet in a predetermined direction along the surface of the female mold.   The bit cleaning device according to any one of claims 1 to 3, further comprising a supply mechanism that supplies a cleaning liquid for cleaning the driver bit to the cloth sheet. The bit cleaning device according to claim 4,
A supply path for supplying a predetermined amount of cleaning liquid into the gap of the female mold;
A bit cleaning device comprising: a discharge path for discharging the cleaning liquid from the gap.

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