JP4882103B2 - Drill thinning apparatus and thinning forming method - Google Patents

Description

  The present invention relates to thinning applied to a drill tip in order to improve the performance of the drill.

  In recent years, there has been a rapid increase in the demand for fine drilling in high-density printed circuit boards, diesel engine fuel injection nozzles, chemical fiber spinning nozzles, bare chip solder ball jigs, and the like. In addition, in these micro-drilling applications, there are some which require a very high aspect ratio drilling, for example, a depth of 4 mm for a diameter of 0.2 mm. In these micro deep hole machining, the machining point of the tip to be cut at the time of cutting stays long in the material that is the work material intermittently, and there is no escape space for the heat generated from the tip. Since the temperature at the point of contact between the drill tip and the member to be drilled becomes very high, twist drills made of a cemented carbide that is difficult to soften even at high temperatures are mainly used.

  However, since cemented carbide has low toughness, there is a drawback that chipping is likely to occur at a fine diameter. Recently, attempts have been made to improve toughness and hardness by refining crystal grains of WC (tungsten carbide), but it is still insufficient in terms of practicality.

  Furthermore, in such a deep hole drilling with a fine diameter, it is difficult to discharge chips, and the temperature of the processing point is high, so that there is a problem that chip welding is likely to occur. When a weld deposit adheres to the tip of the drill, the drilling function inherent to the drill is significantly reduced. However, in the case of a fine-diameter drill, the extremely small size of the weld deposit has a relatively large effect on the overall drill size. Therefore, the adverse effect of this weld is not the ratio of a normal drill.

  From such a viewpoint, the inventors have paid attention to so-called thinning. Thinning is to form a notch with a specific shape at the tip of a drill. In drilling with a drill, the so-called “chisel” at the tip of the drill is pressed against the material in the axial direction, and the material is removed by plastic deformation. Is preferred. In this respect, since a thick drill has sufficient strength, a large axial pressing force can be obtained, but in a fine drill, a large axial pressing force causes a seat refraction loss. Therefore, it is desirable to reduce the size of the “chisel” itself by thinning so that the drill has a smaller diameter so that the pressing force of the chisel portion can be earned even with an axial pressing force that does not cause the refraction loss of the drill itself. . In order to achieve that purpose, the chisel portion is made smaller by thinning, and as a result, the temperature at the machining point is reduced, and the discharge of chips generated during cutting is improved, so that the chips are welded to the drill. Reduce. This thinning process itself is a known technique.

  This technique is required to be processed with rotational symmetry and accuracy more accurately as the diameter of the drill becomes smaller, and in particular, there are very few commercially available products that are thinned with a drill having a diameter of 3 mm or less. .

  Conventionally, as an apparatus for performing a thinning process on the tip of a drill, Patent Document 1 discloses an automatic drill polishing machine, and Patent Document 2 discloses a drill grinding apparatus.

  An automatic drill polishing machine described in Patent Document 1 includes a rotating grindstone, a grindstone moving means, a chuck, a chuck rotating means, a chuck tilting means, a chuck moving means, and a drill edge detection sensor, and the control Based on a control signal from the means, a servo mechanism for operating the grindstone moving means, chuck rotating means, chuck tilting means and chuck moving means is controlled.

  On the other hand, the drill grinding apparatus described in Patent Document 2 is arranged in parallel with the X-axis table, the Y-axis table, the Z-axis table arranged on the Y-axis table, and the Z-axis table parallel to the X-axis direction. An indexing spindle having a function of chucking a drill, a grindstone shaft table disposed on the X-axis table and horizontally rotatable from a position orthogonal to the drill to a predetermined angle position, and a grindstone disposed on the grindstone shaft table A shaft motor, and an outer peripheral surface and a base end outer peripheral surface connected to the outer peripheral surface have a shape corresponding to the tip angle of the drill and the tip angle of the pilot, and a rotating grindstone fixed to the rotating shaft of the grindstone shaft motor. The drill is moved and rotated while controlling each table, indexing spindle and grinding wheel spindle motor, while the rotating grinding wheel is rotated and brought into contact with the drill cutting edge and pilot cutting edge to attach the pilot. By pivoting around a part, it is to simultaneously grind the cutting edge and the pilot cutting edge and a flank of the drill.

  Both devices are said to be capable of thinning the tip of the drill with a rotating grindstone.

Japanese Patent Laid-Open No. 10-217073 JP 2004-142057 A

  In the case of a fine-diameter drill, since the drill diameter is small, the drill main body part has the property of being easily broken. For example, if a drill breaks during processing of a printed circuit board that requires countless micro-hole processing on a single substrate, the breakage also adversely affects the substrate itself, such as incomplete hole processing and circuit pattern damage. Therefore, it is necessary to discard the substrate itself. In particular, if such a situation occurs at the final stage of innumerable hole processing, not only the substrate itself, but also the time required for the processing up to that time is wasted, and the yield of manufacturing the substrate is greatly deteriorated.

  As described above, by forming the thinning at the tip of the drill, the cutting performance of the drill can be improved and the durability can be improved. However, in the apparatus as described in Patent Document 1 and Patent Document 2, the drill has a high aspect ratio, particularly for drilling fine holes (for example, a drill having a drill diameter of 0.5 mm or less). The thinning process could not be performed sufficiently with a high yield. In addition, even if thinning can be performed satisfactorily, it is used for the grinding stone in the thinning part (thinning surface) in the case of machining that simply contacts the rotary grindstone and drill for thinning formation. There was a problem that the unevenness (working edge) due to the grain size of the abrasive grains remained as it was.

  The finer the drill itself, the larger the abrasive grain of the grindstone that drills, relative to the shape of the tip of the drill, and the unevenness of the edge of the cutting edge caused by the abrasive grain induces chipping. Easy situation. The shape of the tip of the drill is complicated, and various tips and recesses are combined to form the tip, which also affects the fact that the possibility of chipping is particularly high compared to other materials to be cut. It seems that there is.

  Further, when the rotating grindstone and the drill are merely brought into contact with each other for thinning formation, burrs generated by cutting are formed at the boundary portion between the thinning surface and other portions (hereinafter referred to as “thinning edge”). Will remain. This burr can increase the drilling resistance of the drill and can also promote the welding of chips, but also in this regard, the smaller the diameter of the burr, the more easily a small burr has a greater effect on breakage.

  As described above, a fine diameter drill is required to have a fine hole drilling, and at the same time, the durability of the drill itself is strongly demanded. However, as the diameter of the drill is made finer, the problems of chipping and thinning edge become more serious. There was a circumstance that

  The present invention has been made to solve these problems, and it is an object of the present invention to particularly improve the durability performance of a fine drill.

The present invention relates to a chuck unit capable of holding a drill to be thinned, a grindstone unit having a rotating grindstone, and a thinning portion of the drill with respect to a cutting surface of the grindstone in the thinning state of the drill A rotating mechanism for rotating the chuck unit along a curved surface centered on a predetermined position so as to swing, and the rotary grindstone has an arcuate cross-sectional end that passes through its rotation center. The predetermined position is the center of the circular arc, and the drill is thinned by the outer peripheral end surface of the rotary grindstone to constitute the drill thinning device, thereby solving the above-mentioned problem.

Further, the present invention is a method for forming a thinning for a drill, wherein the thinning portion of the drill is swung with respect to the cutting surface of the rotating whetstone while the thinning is formed on the drill with a rotating whetstone. A step of rotating the chuck unit holding the drill along a curved surface centered on a predetermined position, and the rotary grindstone has a circular end at a cross-section passing through its rotation center, and the predetermined position is The above-mentioned problem is similarly solved by forming a thinning by performing a thinning process on the drill with the outer peripheral end surface of the rotating grindstone at the center of the arc .

  If the edge of the cutting edge existing around the thinning surface, that is, the degree of unevenness of the thinning edge is large, chipping is likely to occur due to external force applied during drilling with a drill. In other words, if the thinning surface and the peripheral edge of the cutting edge, that is, the thinning edge can be finished as smooth as possible (if the surface roughness can be improved), the cause of chipping can be eliminated. Further, the smoothing of the thinning surface has an effect of reducing chip welding.

In the present invention, by adopting the above-described configuration, in particular, the “swing” configuration, the drill tip is formed while maintaining the effect of accurately forming the intended shape (not too large) thinning. It is possible to improve the surface roughness of the thinning surface, and to remove burrs at the thinning edge caused by the thinning formation. Moreover, in this invention, the cross-sectional edge part which passes through the rotation center of the said rotating grindstone is made into a circular arc, and the said predetermined position is comprised as a center of the said circular arc. As a result, it is possible to improve the surface roughness of the thinning surface while minimizing the excessive thickness of the thinning surface due to swinging (the thinning surface is formed beyond the originally intended thinning surface). Yes.

  Moreover, you may comprise the said drill (the thinning formation state) with a fine diameter drill whose diameter is 0.5 mm or less.

  Thereby, accurate thinning can be easily performed without relying on a skilled worker and without requiring a special technique.

  The rotation mechanism may be configured to rotate the chuck unit while fixing at least the position of the drill in the axial direction.

  As a result, the swing operation can be realized without requiring a complicated movement of the chuck unit, and a reduction in machining accuracy due to an error can be prevented.

  By applying the present invention, it is possible to manufacture a durable drill by preventing a temperature rise at a processing point, welding of chips, and the like, particularly in a fine diameter drill, by applying the present invention.

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

<Thinning device configuration>
FIG. 1 is a perspective view of a thinning apparatus according to the present invention. FIG. 2 is a front view of the thinning apparatus according to the present invention.

  The thinning apparatus 1 includes a grindstone unit 10 having a rotating grindstone 11 installed and fixed at a specific position on a base 2 serving as a base, and a chuck unit 20 capable of holding a drill 3 to be thinned. A stage unit 30 capable of moving and positioning the chuck unit 20 relative to the grindstone unit 10 in at least the Y-axis direction which is the axial direction of the drill 3 and the X-axis direction which is a direction perpendicular to the axial direction in the horizontal plane. And a positioning unit 40 that can position the drill 3 at a predetermined position other than the thinning position of the drill 3.

  The grindstone unit 10 rotates a motor 16 disposed and fixed on a substantially L-shaped motor base 17, a coupling 15 that transmits the rotation of the motor 16, and the rotation of the motor 16 transmitted by the coupling 15. A grindstone drive shaft 12 that transmits to the grindstone 11, a housing 14 that rotatably holds the grindstone drive shaft 12, and a rotating grindstone 11 that is rotatably provided on the grindstone drive shaft 12 in the housing 14. It is configured. The power supply ON / OFF of the motor 16 and the rotation speed of the motor 16 can be freely controlled by the motor control unit 18. The rotary grindstone 11 is a disk-type rotary grindstone whose cross section passing through its rotation center is an arc (details will be described later).

  The stage unit 30 includes a Y stage 32 capable of moving and positioning the chuck unit (details will be described later) 20 in the axial direction of the drill 3 (hereinafter simply referred to as “Y-axis direction”), and the Y-axis direction. A manual adjustment knob 32A that can be manually fine-tuned, an X stage 31 that can move and position the chuck unit 20 in a direction perpendicular to the Y-axis direction (hereinafter simply referred to as "X-axis direction"), and The stage control unit 33 is configured to control the X stage 31 and the Y stage 32. These stages 31 and 32 have a built-in scale for detecting position information, and since a commercially available product with a sufficiently high position reproducibility of 2 to 3 μm can be used, the lightweight chuck unit 20 is moved. Combined with this, it can sufficiently cope with the thinning of the fine-diameter drill 3. Although not employed in the present embodiment, the chuck unit 20 can be moved and fixed in a direction perpendicular to the XY plane, that is, in the vertical direction (hereinafter simply referred to as “Z-axis direction”). It is good also as a structure which provides Z stage. With such a configuration, it is possible to deal with grindstones having different diameters and to improve the degree of freedom of thinning formation. That is, it becomes possible to form a three-dimensional arbitrary thinning shape.

  The positioning unit 40 includes a plate-like gauge portion 41 having a thickness in the Y-axis direction, and a gauge support portion 42 that supports the gauge portion 41, and observes the “predetermined position” from the Y-axis direction. Therefore, the mounted pedestal (support base) can be adjusted, and the Z-axis direction can be adjusted so as to facilitate the observation and measurement of FIGS. A first camera unit 43 and a monitor 44 capable of projecting an image taken by the first camera unit 43 are provided. A groove 41A is formed on the surface (upper surface) of the gauge portion 41 so as to penetrate in the Y-axis direction (see FIG. 8, details will be described later). Note that the positioning unit in the present embodiment includes the monitor 44, but the monitor itself can use a general purpose, and in that case, it can be omitted. The first camera unit 43 is disposed so that the groove 41A provided in the gauge portion 41 can be observed from the Y-axis direction, and an objective lens 47 is disposed at the tip of the CCD camera 45 via a lens barrel 46. ing. With such a configuration, the shape of the drill tip can be observed from the axial direction of the drill, and by comparing the shape of the groove 41A provided in the gauge portion 41 with the shape (position) of the drill (this point Details will be described later), and the position of the drill in the X-axis direction and the position in the Z-axis direction can be specified. In addition, it is possible to clearly determine whether or not the thinning state is formed in the intended size and depth so that the thinning applied to two or more places on one drill is rotationally symmetric. It becomes. A ring illumination 48 is provided around the objective lens 47 to clearly show the shape of the drill tip placed at the observation position. The video imaged by the first camera unit 43 can be monitored by the monitor 44. Although not shown, the thinning device 1 photographs the gauge portion 41 from a direction perpendicular to the Y axis, for example, the X axis direction or the Z axis direction, separately from the first camera unit 43 described above. A second camera unit is provided that can. With such a configuration, the position of the drill in the Y-axis direction can be specified based on the video from the second camera unit. Since the positioning unit 40 is arranged at a position away from the processing position R, a relatively large size such as a jig (gauge) or a camera is used in this way using a wide space where the grindstone unit 10 or the like does not exist. A precision sensor means is provided as a component thereof. The configuration of the positioning unit is not limited to that described above, and various configurations can be employed as long as the drill can be positioned.

  Next, the chuck unit 20 will be described in detail with reference to FIGS. 3 and 4. 3A is a perspective view of the drill chuck unit 20, FIG. 3B is the same plan view, FIG. 3C is the front view (drill mounting side view), FIG. 3D is the right side view, and FIG. ) Is a rear view (side surface where a drill is not mounted), and FIG. 4 is a partially exploded configuration diagram of the drill chuck unit.

  In the chuck unit 20, a chuck 21B that directly holds the drill 3 and a cylindrical chuck body 21A provided with the chuck 21B are rotatably held with respect to the rotating body 23A. The chuck body 21 </ b> A communicates with the rotating disk 24 </ b> A so as to penetrate the rotating body 23 </ b> A. The chuck main body 21A and the rotating disk 24A are fixed by a rotating disk fixing bolt 24E that is screwed into a bolt hole 24A ′ formed in the rotating disk 24A. Further, in the chuck body 21A disposed through the rotating body 23A, a ring-shaped chuck body axially fixed first plate 25A is disposed on the front side of the rotating body 23A, and a ring shape is also formed on the back side. The chuck body axially fixed second plate 25B is disposed. These two plates are fixed to the chuck main body 21A by bolts 23M screwed into bolt holes 25A 'and 25B' respectively formed in the plates, and the position of the chuck main body 21A in the axial direction can be regulated. . At this time, an appropriate gap is secured in the axial direction between the rotating body 23A, the chuck body axially fixed first plate 25A, and the second plate 25B so that the chuck body 21A can rotate around the axis. . A knock pin 25C is formed on the chuck body axially fixed second plate 25B described above. Furthermore, a rotation base 24B having the same diameter as the rotation disk 24A is provided so as to wrap the chuck body axially fixed second plate 25B. A rotation restricting groove 24D is formed in the rotation base 24B in the circumferential direction of 180 °, and the knock pin 25C is disposed so as to fit into the groove 24D. Further, the rotation base 24B is fixed to the rotation main body 23A (convex portion thereof) by a rotation base fixing bolt 24C screwed into a bolt hole 24B ′ formed in the rotation base 24B. That is, the knock pin 25C is contacted and regulated by the groove end portions (groove end A portion 24D1 and groove end B portion 24D2) of the rotation restricting groove 24D, so that the drill 3 can be rotated 180 ° easily and accurately. . A chuck body fixing bolt 23E that passes through itself and can contact the chuck body 21A (rotating disc 24A) is mounted on the upper surface of the rotating body 23A, and the bolt 23E is loosened or tightened. Thus, the rotating disk 24A, that is, the chuck body 21A and further the drill 3 can be freely rotated or fixed with respect to the rotating body 23A.

  Below the rotating body 23A, there is provided a fan-shaped rotating block 23A 'that draws an arc centered on a predetermined center of rotation (details will be described later). A rotation base 23B is arranged so as to correspond to the rotation block 23A ′. That is, the curved surface r ′ formed on the rotation block 23A ′ and the curved surface r provided on the rotation base 23B have an arc shape having the same center point.

  A first support plate 23F is disposed on the front side of the rotation base 23B, and regulates the position of the front side of the rotation main body 23A (rotation block 23A ′). The first support plate 23F is fixed to the rotation base 23B with bolts 23H. Similarly, a second support plate 23G is disposed on the back side of the rotation base 23B, and regulates the position on the back side of the rotation body 23A. The second support plate 23G is also fixed to the rotation base 23B by a bolt 23H. Further, the rotation block 23A ′ is formed with a guide groove 23K along the curved surface r ′ so as to penetrate from the front side to the back side, and the follower bearing 23L fitted into the guide groove 23K has a first structure. It is fixed to the support plate 23F and the second support plate 23G. The rotation base 23B includes a first rotation bolt support plate 23I that supports the first rotation bolt 23C, and a second rotation bolt support plate 23J that supports the second rotation bolt 23D. These support plates 23I and 23J are threaded through and the respective rotation bolts 23C and 23D are in contact with the side surface of the rotation block 23A ′ in the rotation body 23A. That is, the drill 3 held by the chuck body 21B can be rotated (oscillated with respect to the rotating grindstone) by adjusting the tightening amounts of the respective rotating bolts 23C and 23D. As described above, the rotation mechanism in the present embodiment is configured such that the chuck unit (rotation main body) rotates while fixing at least the position of the drill in the axial direction. As a result, the swing operation can be realized without requiring a complicated movement of the chuck unit, and the processing accuracy is prevented from being lowered due to an error.

  The rotating disk 24A, the rotating base 24B, the rotating base fixing bolt 24C, the rotation restricting groove 24D, the rotating disk fixing bolt 24E, and the knock pin 25C constitute the rotating mechanism 24.

  Further, the rotation main body 23A (rotation block 23A ′), the rotation base 23B, the first rotation bolt 23C, the second rotation bolt 23D, the chuck body fixing bolt 23E, the first support plate 23F, and the second support plate. 23G, the bolt 23H, the first rotation bolt support plate 23I, the second rotation bolt support plate 23J, the guide groove 23K, and the follower bearing 23L constitute the rotation mechanism unit 23.

<Thinning formation procedure>
Next, a procedure for forming a thinning using the thinning apparatus 1 will be described with reference to FIGS. FIG. 5 is a flowchart showing the thinning process, FIG. 6 is a plan view of the thinning apparatus, showing the relationship between the thinning position and the observation position, and FIG. 7 shows the rotation at the processing position. It is a related figure of a grindstone and a drill tip.

  First, the power of each part of the thinning apparatus 1 is turned on (S1). Specifically, the power source of the stage control unit 33, the power source of the video signal processing device (not shown), the power source of the monitor 44, the power source of the motor control unit 18, the power source of the ring illumination 48, etc. are turned on.

  Next, the chuck unit 20 is moved to a position where the drill 3 to be processed is easily attached (for example, between the processing position and the observation position in FIG. 6), and then the drill 3 is attached (S2). More specifically, the chuck 3 is attached to the chuck body 21 </ b> A after the chuck fastening bolts 22 existing on the back surface of the chuck portion 21 are loosened. After that, by tightening the chuck tightening bolt 22, the installation of the drill 3 is completed.

  Next, various data for forming the thinning, for example, information on the width, depth and shape of the thinning to be formed, and the diameter of the drill are input in advance (S3). Note that when the type of drill, the shape of the thinning, etc. are always constant, this step can be omitted by storing the data in the apparatus in advance. In addition, it is not an indispensable component of this invention that the said thinning apparatus 1 itself memorize | stores these data.

  Next, the chuck unit 20 to which the drill 3 has been attached is moved to an observation position (a predetermined position to be positioned) (S4). Specifically, by operating the stage control unit 33, the stage control unit 33 is moved to the position of the groove 41 </ b> A in the gauge unit 41 provided in the positioning unit 40.

  Next, the drill 3 that has moved to the observation position is adjusted so as to be positioned at the preset origin in the positioning unit 40 (S5).

  Next, it is confirmed whether or not it is correctly located at the origin (S6). If it is not at the origin, the process returns to step S5 to readjust, and if it is at the origin, the process proceeds to step S7.

  Next, it adjusts so that the rotation attitude | position of the drill 3 hold | maintained at the drill chuck | zipper 22B may become appropriate (S7).

  Next, it is determined whether or not the posture is appropriate (S8). If the posture is not appropriate, the process returns to step S7 to readjust, and if the posture is appropriate, the process proceeds to step S9. Specific methods of these steps S5 to S8 will be described later separately.

  Next, the chuck unit 20 is moved to the machining position (S9). The movement to the machining position at this time is performed by driving (feeding forward) the stage unit 30 based on the data of the origin adjusted earlier.

  Next, a thinning process is performed (S10). The processing is realized by driving and controlling the stage unit 30 based on the data input in step S3 and the origin data. As shown in FIG. 7, this processing is performed by an angle formed by a line L1 connecting the processing position of the drill 3 and the rotation center M of the grindstone 11 and a line L2 parallel to the Y axis passing through the rotation center M of the grindstone 11. α is a position where 40 ° ± 10 °. In the case of an angle smaller than this, it becomes unsuitable when the swing operation described later is to be performed. Of course, if it is assumed that no oscillation is performed, a smaller angle is not a problem. If the angle is larger than this, the thinning process itself cannot be performed properly. The positional relationship shown in FIG. 7 indicates the basic position of the present apparatus, and the Y-axis direction position and the Z-axis direction position can be changed in order to obtain a desired thinning shape according to the thickness of the drill. it can.

  Subsequently, rocking is performed (S11). Specifically, the thinning process of the drill 3 with respect to the cutting surface of the rotating grindstone 11 is performed by rotating the rotating main body 23A by sequentially tightening the first rotating bolt 23C and the second rotating bolt 23D. The surface is rocked. As a procedure, for example, by first tightening the first rotation bolt 23C, the drill held by the chuck unit 20 is rotated rightward toward the drill tip side. Next, the drill held by the chuck unit 20 is rotated leftward toward the drill tip side of the drill 3 by tightening the second rotating bolt 23D while loosening the first rotating bolt 23C. Move. Thereafter, the same operation may be repeated. The detailed movement and action of the swing (rotation) will be described later. In the present embodiment, manual adjustment using the first and second rotating bolts 23C and 23D is performed. However, the present invention is not limited to this. For example, the rotating operation is performed in conjunction with a motor or the like. You may comprise so that it may control automatically.

  Next, the chuck unit 20 is moved again to the observation position (origin) (S12).

  Next, the thinning state is confirmed by the image projected on the monitor 44 through the first camera unit 43 (S13).

  At this time, it is determined whether or not the thinning state is good (S14). When the thinning state is good, that is, when the thinning process of the part is completed, the process proceeds to step S18, and the thinning state is good. If not, i.e., if the thinning process has not yet been completed, the process proceeds to step S15.

  If the process proceeds to step S15, it is determined whether or not there is room for further rework. At this time, if the amount of cutting at the time of thinning formation is excessive or defective, the machining of the drill is stopped (S16).

  On the other hand, if there is room for rework, the process returns to step S5 (or step S9), and thinning is reworked (S17).

  Next, when the state of the thinning performed is good, it is determined whether two thinning processes have been performed on the drill 3 (S18). If the two-point thinning has already been performed, the process proceeds to step S19, and the thinning for the drill ends.

  On the other hand, if the thinning has not been completed in two places, the process proceeds to step S20.

  Next, the drill is rotated 180 ° (S20). Specifically, the adjustment is performed by loosening the chuck body fixing bolt 23E and rotating the rotating disk 24A. At this time, since the thinning process is performed in a state in which the knock pin 25C is adjusted to come into contact with one groove end (groove end A portion 24D1 or groove end B portion 24D2) of the rotation restricting groove 24D formed in the rotation base 24B in advance. Then, by loosening the chuck body fixing bolt 23E and rotating it to the limit of rotation of the rotating disk 24A, the knock pin 25C comes into contact with the other groove end, and a simple and accurate rotation of 180 ° can be realized. Finally, if the chuck body fixing bolt 23E is tightened, the rotation operation is completed. Here, the control of the rotational posture of the drill 3 is also performed manually, but it may be configured to be performed automatically using a motor or the like.

  Next, the process returns to step S5 (or step S9), and the second thinning process is performed (S21).

  Thus, in the thinning formation in the apparatus, the heavy grindstone unit is fixed and does not move. As a result, the position variation element of the grindstone can be removed, and the positional accuracy during processing is improved. In addition, since thinning is performed by driving the stage unit from the origin, it is always possible to easily form thinning of the same quality without being a skilled worker.

<Origin positioning using positioning unit 40>
Next, positioning to the origin using the positioning unit 40 will be described with reference to FIGS. FIG. 8 is a diagram showing the relationship between the tip of the drill 3 and the positioning unit 40 as viewed from the first camera unit 43, and FIG. 9 is a diagram showing a positioning panel 56 prepared on the screen of the monitor 44. 10A is a view of the state of FIG. 8 as viewed from the upper side (Z-axis side), and FIG. 10B is an enlarged view of the R portion of FIG. In each drawing, the scale is exaggerated for easy understanding.

  As shown in FIG. 8, the alignment of the drill 3 in the X-axis direction and the alignment in the Z-axis direction with respect to the position of the origin O is the shape of the groove 41A provided in the gauge portion 41 and the drill to be processed. This is done by comparing the three shapes.

  A semicircular groove 41A is formed on the surface of the gauge portion 41 so as to penetrate in the Y-axis direction. The portion is displayed as an image on the monitor 44 by the first camera unit 43 (see FIG. 8). On the other hand, as shown in FIG. 9, a positioning panel 56 showing the position of the origin O in the X-axis direction and the Z-axis direction with respect to the shape of the groove 41 </ b> A in the gauge portion 41 is prepared. The positioning panel 56 has the position of the origin O in advance on the basis of the image of the groove 41A projected on the monitor (the image of the first camera unit 43 appropriately enlarged by 50 to 500 times according to the thickness of the drill). It is a panel described. The position of the origin O itself is previously determined on the monitor screen using a pin gauge (not shown) which is a high-precision solid axis. Using this positioning panel 56, the lines of the left and right surfaces (A surface and E surface) of the groove 41 on the surface of the gauge portion 40 and the line (B surface) corresponding to the chisel edge of the drill 3 are on the same line. By adjusting, the tip of the drill 3 can be adjusted to the coordinate of the origin O in the Z-axis direction. Furthermore, the rotation posture of the drill 3 can be adjusted. Here, as a method of adjusting the rotation posture of the drill 3, after loosening the chuck body fixing bolt 23E, the rotation disk 24A is used to rotate the drill 3 (chuck body 21A) on the screen of the monitor 44. The chuck body fixing bolt 23E is tightened at an appropriate position in accordance with a predetermined rotational posture. Further, the drill 3 can be adjusted to the coordinate of the origin O in the X-axis direction by adjusting the positions of the left and right gaps (C and D) generated between the drill and the groove 41A to be equal. Actually, since a circle corresponding to the size of the drill is drawn on the panel surface, it is sufficient to adjust the position so that the circle is located. Since the positioning panel 56 is made of a transparent acrylic plate or the like, it is possible to indicate the origin of the drill 3 by overlapping it on the screen of the monitor 44 (overlapping so that the shape of the groove 41A matches). . The user can easily specify the position in the X-axis direction and the Z-axis direction by simply moving the drill to the indicated position (circle) while checking the monitor 44. Further, in order to increase the ease of position adjustment, a commercially available cursor or pattern projection device may be used in combination, and the cursor or pattern may be appropriately superimposed on the image by the camera unit 43 on the screen of the monitor 44.

  Thus, the function of the positioning unit 40 allows the drill 3 to be accurately positioned while keeping the drill 3 in a non-contact state with any sensor means, and there is no risk of breakage due to contact during positioning. In addition, the said panel may prepare several sheets according to the diameter of a drill, and may show the position (circle) corresponding to each diameter on the panel surface of 1 sheet. Further, in order to increase the ease of position adjustment, a commercially available cursor or pattern projection device may be used in combination, and the cursor or pattern may be appropriately superimposed on the image by the camera unit 43 on the screen of the monitor 44. Alternatively, an image corresponding to the positioning panel 56 may be directly displayed on the screen of the monitor 44 as a layer. Since the image displayed on the monitor 44 is an image enlarged appropriately by 50 to 500 times according to the thickness of the drill, even with such simple adjustment, the positional accuracy in micron units is ensured. ing.

  On the other hand, the coordinate of the origin in the Y-axis direction is determined using an image of a second camera unit (not shown) that can shoot the gauge unit 41 from the X-axis direction or the Z-axis direction. 10, adjustment is performed so that the tip of the drill 3 is positioned on the reference surface 41 </ b> B of the gauge portion 41. By this adjustment, the Y-axis direction alignment with the origin O of the drill 3 is performed.

<Oscillating (turning) operation and action>
The swinging (turning) operation and its action in step S11 will be described with reference to FIGS. FIG. 11 is a view showing the turning center of the chuck unit 20, FIG. 12 is a view showing a turning state of the drill that swings with respect to the rotating grindstone, and FIG. 13 is a swing (turning). FIG. 6A is a diagram schematically illustrating the effect of FIG. 5A, and FIG. 5B is a diagram illustrating a case where the rocking (turning) is not performed, and FIG.

  The rotation main body 23A of the chuck unit 20 is configured to rotate about the rotation center O1. That is, the curved surface r ′ formed on the rotation block 23A ′ and the curved surface r provided on the rotation base 23B are formed by an arc having a radius R with the rotation center O1 as the center. In the present embodiment, the rotation center O1 is set to be the arc center of the rotating grindstone as shown in FIG. That is, the cross section passing through the rotation center of the rotary grindstone 11 in this embodiment is an arc S, and the arc S of the grindstone cross section and the curved surfaces r and r ′ are concentric circles. In addition, if it demonstrates just in case, in this embodiment, the axial center of the drill 3 hold | maintained at chuck | zipper 22B and the rotation center O1 do not correspond.

With this configuration, when the rotation mechanism unit 23 is operated, the thinning surface of the drill 3 swings along the cutting surface (arc S) of the grindstone (see FIG. 12). That is, while suppressing an excessive increase of thinned face by swinging the (that thinning surface is formed beyond the original thinned face that is planned) to a minimum, that has become possible to improve the surface roughness of the thinned face .

  The effect | action that this surface roughness improves is demonstrated using FIG. Since the abrasive surface of the grindstone is composed of densely packed abrasive grains, when it is simply cut with a rotating grindstone (when it does not rock), the diameter of the abrasive grains is approximately along the rotation direction of the grindstone. A certain degree of unevenness (processed edge) occurs. This arises from the limitation of the physical size of the abrasive grains and cannot be solved except by changing the diameter of the abrasive grains to a finer one. However, the size of the machining edge is reduced by moving the grindstone and the cutting member (drill) relative to each other in a direction substantially perpendicular to the rotation direction of the rotating grindstone by swinging while the grindstone is rotated. In addition, in FIG. 13, for the sake of convenience of explanation, it is shown as a view in which the grindstone side swings. Specifically, when the average height roughness of the thinning surface (processed surface) is Ra and the maximum height roughness is Rz, Ra = 0.0164 μm, Rz = What was 0.0914 μm is Ra = 0.115 μm and Rz = 0.0459 μm under the same conditions when rocking is performed (the numerical values are measured twice by a non-contact three-dimensional measuring machine). Average value of measurement). That is, it is possible to improve the surface roughness of the thinning surface by swinging the thinning surface of the drill with respect to the cutting surface of the rotating grindstone.

  Further, by swinging, there is an effect of removing burrs (thinning edge burrs) that may be caused by thinning formation.

  By improving the surface roughness and removing burrs, the temperature rise at the drilling point is further suppressed compared to drills that are simply thinned (without rocking), and chip discharge is improved. Welding can be prevented. As a result, it is possible to manufacture a drill having excellent durability.

  In this embodiment, the rotation mechanism for swinging is provided on the chuck unit 20 side. However, for example, the same effect can be obtained by providing the rotation mechanism on the rotating grindstone unit 10 side. Is possible.

  Further, in this specification, it is described as an apparatus that forms only thinning, but the present invention is not limited to this. For example, the apparatus may be incorporated in a drill manufacturing apparatus that manufactures a drill itself. .

  Further, in the description of the embodiment, the description is made on the assumption that the drill is a fine diameter, but the thinning apparatus and the thinning forming method according to the present invention are not limited to the fine diameter drill, and the diameter is larger. Even when applied to a drill having a diameter, it is useful because it can improve the accuracy of thinning formation.

  The fine-diameter drill thinned using the thinning apparatus according to the present invention includes, for example, drilling for fuel injection nozzles for diesel engines including high-density printed circuit boards, drilling for chemical fiber spinning nozzles, and treatment for solder balls of megachips. Very suitable for drilling holes in tools.

The perspective view of the thinning apparatus which concerns on this invention Front view of the thinning apparatus according to the present invention (A) is a perspective view of the drill chuck unit, (B) is a plan view thereof, (C) is a front view thereof, (D) is a right side view thereof, and (E) is a rear view thereof. Partially exploded configuration diagram of the drill chuck unit Flow chart showing the thinning process A plan view of the thinning device, showing the relationship between the thinning processing position and the observation position Relationship diagram between rotating wheel and drill tip at machining position Relationship between drill tip and positioning unit as seen from the first camera Positioning panel prepared on the monitor side (A) is the figure which looked at the state of FIG. 8 from the upper side (X-axis side), (B) is the R section detailed enlarged view of (A). Diagram showing the center of rotation of the chuck unit The figure which shows the rotation state of the drill which rocks with respect to a rotating grindstone It is a figure which shows the effect of rocking | fluctuation (rotation) typically, (A) is the figure which showed the case where rocking | fluctuation (rotation) is not carried out, (B) was rocking | fluctuating (rotation). Illustration showing the case

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Thinning apparatus 2 ... Base 3 ... Drill 10 ... Grinding wheel unit 11 ... Rotary grindstone 12 ... Grinding wheel drive shaft 14 ... Housing 15 ... Coupling 16 ... Motor 17 ... Motor base 18 ... Motor control part 20 ... Chuck unit 21 ... Chuck Part 21A ... Chuck body 21B ... Chuck 22 ... Chuck tightening bolt 23 ... Turning mechanism part 23A ... Turning body 23A '... Turning block 23B ... Turning base 23C ... First turning bolt 23D ... Second turning bolt 23E ... Bolt for fixing the chuck body 23F ... First support plate 23G ... Second support plate 23H ... Bolt 23I ... First rotation bolt support plate 23J ... Second rotation bolt support plate 23K ... Guide groove 23L ... Follower bearing 23M ... Chuck Main body axial fixing bolt 24 ... Rotation mechanism 24A ... Rotary disc 24B ... Time Base 24C ... Rotating base fixing bolt 24D ... Rotation restricting groove 24D1 ... Groove end A part 24D2 ... Groove end B part 24E ... Rotating disc fixing bolt 25 ... Chuck body axial fixing part 25A ... Chuck body axial fixing first plate 25B ... Chuck body axially fixed second plate 25C ... Knock pin 30 ... Stage unit 31 ... X stage 32 ... Y stage 32A ... Manual adjustment knob (Y stage)
33 ... Stage control unit 40 ... Positioning unit 41 ... Gauge unit 41A ... Groove 41B ... Reference plane 42 ... Gauge support unit 43 ... First camera unit 44 ... Monitor 45 ... CCD camera 46 ... Lens barrel 47 ... Objective lens 48 ... Ring illumination 56 ... Positioning panel M ... Wheel rotation center O ... Drill axis O1 ... Rotation center

Claims (6)

A chuck unit capable of holding a drill to be thinned,
A grinding wheel unit having a rotating grinding wheel;
A rotating mechanism that rotates the chuck unit along a curved surface centering on a predetermined position so that a thinning portion of the drill swings with respect to a cutting surface of the grindstone in the thinning state of the drill When,
Equipped with a,
The rotating grindstone has a circular arc at the end of the cross section passing through its rotation center,
The predetermined position is a center of the arc;
A thinning device for a drill, wherein the drill is thinned by an outer peripheral end face of the rotating grindstone . In claim 1,
The drill is a thin drill having a diameter of 0.5 mm or less. In claim 1 or 2,
The drill thinning apparatus, wherein the rotation mechanism rotates the chuck unit while fixing at least the axial position of the drill. A thinning forming method for a drill,
The chuck unit that holds the drill is centered on a predetermined position so that the thinning portion of the drill is swung with respect to the cutting surface of the rotary whetstone while the thinning is formed on the drill with the rotary whetstone. viewing including the step of rotating along the curved surface,
The rotating grindstone has a circular arc at the end of the cross section passing through its rotation center,
The predetermined position is a center of the arc;
A thinning forming method for a drill, comprising: thinning the drill with an outer peripheral end surface of the rotating grindstone . In claim 4 ,
The said drill is a fine diameter drill whose diameter is 0.5 mm or less. The thinning formation method of the drill characterized by the above-mentioned. In claim 4 or 5 ,
The drill thinning formation method, wherein the rotation is performed by rotating the chuck unit while fixing at least the axial position of the drill.

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