JP2011148012A - Drilling and tapping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drilling and tapping device capable of reliably drilling and tapping by preventing tools such as a drill and a tap from being broken. <P>SOLUTION: This drilling and tapping device includes a first beam 7 rotatable on a horizontal plane, a second beam 9 which is connected to the first beam so as to rotate on a horizontal plane and structured in the form of a parallel link rotatable on a vertical plane, and a tool unit supported on the second beam 9. The second beam 9 is configured so as to be biased upward with a tension spring 15a and to be biased downward with a tension spring 15b. These tension springs 15a, 15b are connected to a spring connection member 14. By moving upward or downward and fixing the spring connection member 14, the biasing direction and the biasing force of the second beam 9 provided by the springs 15a, 15b can be changed and adjusted. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a drill / tapping device for drilling or internally threading a workpiece.

  Conventionally, when drilling or threading a workpiece, breakage of a drill or a tap that is a tool has been a problem. For such a problem, a hole drilling method and apparatus shown in Patent Document 1 have been proposed. Yes.

  In the drilling method and apparatus of Patent Document 1, a spindle motor that rotates a drill is supported by a restoring element such as an electromagnet and a damping element such as an actuator, and the spindle motor is in an X, Y, Z orthogonal coordinate system ( It is configured such that it can be displaced in a three-dimensional space. At the stage where the drill comes into contact with the workpiece surface, the support force by the restoring element and the damping element is weakened, and the reaction force when the drill comes into contact with the workpiece is absorbed by the displacement of the spindle motor, while suppressing the vibration of the spindle motor. To prevent breakage. Thereafter, when the contact pressure increases to such an extent that the drill can cut the workpiece, the support force of the spindle motor is instantaneously increased to prevent the shaft from swinging.

  Further, in the hole drilling device of Patent Document 1, in addition to allowing the spindle motor or the drill to be displaced by the reaction force received by the drill as described above, by controlling the drive of the feed motor that sends the drill in the axial direction, Thrust load exceeding the reference value does not act on the drill.

JP-A-6-71509

  According to the drilling method and apparatus shown in Patent Document 1, breakage of the drill during drilling occurs although drill breakage at the stage where the drill contacts the workpiece can be prevented. That is, during drilling, various factors such as the bite of chips, the shape of the drill, and the composition of the workpiece are intertwined, and the rotational load torque acting on the drill fluctuates in a complicated manner. These are combined stresses, and not only a simple rotational load but also a force in a direction that moves the shaft in a complex manner acts on the drill. However, in Patent Document 1, the support force of the spindle motor is enhanced at the drilling stage. Therefore, the force acting on the drill cannot be absorbed, resulting in a breakage of the drill. Patent Document 1 also shows an embodiment in which a spindle motor is supported by a spring and a damper so as to be movable in the XY plane. However, even in this case, the complicated movement of the drill due to the combined stress is completely prevented by the spring and the damper. It is impossible to attenuate and absorb, and again the drill will be broken. Rather, the vibration of the spring is amplified by the influence of a complicated force, which may promote breakage of the drill. In addition, the reaction force of the rotational load torque acting on the drill causes a rotational displacement around the Z axis of the spindle motor, and this and the elasticity of the spring causes rotational vibration of the spindle motor itself, which promotes breakage of the drill, Problems such as damage to the spindle motor support system also occur.

  Further, the thrust load to be applied to the drill or the tap (the axial load acting on the drill or the tap) is different between the case of drilling and the case of performing female threading. In drilling, the thrust load due to the weight of the tool unit from the spindle motor to the drill can be tolerated. However, in the internal thread cutting process, the thrust load must be set to a low value. There are many cases where it is necessary. On the other hand, in the hole drilling method and apparatus of Patent Document 1, since the thrust load at the time of drilling is controlled by controlling the feed motor, a feed motor control program is used when female threading is performed. There are problems such as the need for changes. In addition, when it is necessary to reduce the thrust load due to the weight of the tool unit, there is a problem that drive control of the feed motor is extremely difficult.

  The present invention was created in view of the above problems, and an object of the present invention is to provide a drill / tapping device that can prevent breakage of tools such as drills and taps and can reliably perform drilling and internal thread cutting. . In order to achieve this object, the present invention comprises a first beam that can swivel in a horizontal plane, and a parallel link that is pivotally connected to the first beam in a horizontal plane and that can swivel in a vertical plane. A drill unit for drilling or internally threading a workpiece with the tool unit, and a tool unit having a tool that is supported by the second beam and that rotates by receiving a drive from a rotational drive source. A tapping device, which is provided with a spring connecting member that can move in the vertical direction and can be fixed at a desired position, and is supported at one end of the spring connecting member so as to be able to bias the second beam upward. A first spring and a second spring supported on the other end of the spring coupling member so as to be able to be biased so as to pivot the second beam downward are provided.

  The first beam and the second beam are preferably arranged at an angle of about 90 ° at all times, and the second beam is preferably provided so as to extend parallel to the horizontal plane. Further, the spring connecting member is always clamped and fixed between a stopper plate and an adjusting plate provided adjacent to the second beam, and is configured to be position-adjustable by loosening a screw that holds the adjusting plate on the stopper plate. In this case, it is desirable that the screw for fixing the adjustment plate to the stopper plate is a butterfly bolt.

  Since the tool unit is supported on the balance arm that can be swiveled to perform drilling or female threading, the balance arm can be subtly swiveled against complex forces acting on the tool during drilling or female threading. This makes it possible to automatically align the tool to the optimum position. In addition, by adjusting the fixing position of the spring connecting member, the biasing direction of the second beam and the force for biasing the second beam can be easily changed and adjusted, which is optimal for each of hole machining and female threading. It becomes possible to set the thrust load. Further, since the first beam and the second beam are arranged at an angle of about 90 °, the rotation reaction force of the tool unit can be received at a pressure angle of about 0 °, and the position of the tool unit by the rotation reaction force can be received. Deviation can be prevented. As a result, breakage of the drill or tap during processing can be prevented, and reliable drilling or internal thread cutting can be performed. In particular, small-diameter drills and taps tend to break during machining, but this drill / tapping machine can prevent such small-diameter drills or taps from breaking, making accurate drilling and internal threading accurate. There is also an advantage that it can be performed reliably. In addition, the spring connecting member is always clamped and fixed between the stopper plate and the adjustment plate, and is configured so that the position can be adjusted by loosening a screw that holds the adjustment plate to the stopper plate. The force for energizing the two beams can be easily changed and adjusted. This effect becomes prominent by using a butterfly bolt as a screw for fixing the adjustment plate to the stopper plate.

It is a perspective explanatory view of a drill and tap processing device according to the present invention. 1 is a perspective view of a drill / tapping apparatus according to the present invention. 1 is a front view of a drill / tapping apparatus according to the present invention. 1 is a plan view of a drill / tapping apparatus according to the present invention. FIG. 4 is an enlarged partially cutaway cross-sectional view taken along line B-B in FIG. 3, showing a state in which the second beam has turned downward to the bottom dead center. FIG. 5 is an enlarged partially cutaway cross-sectional view taken along line B-B in FIG. 3, showing a state in which the second beam is pushed up by the lift and pivoted upward. FIG. 3 is an enlarged partially cutaway cross-sectional view taken along line AA in FIG. 2. It is a principal part expansion partial notch sectional view which shows the state of the spring connection member at the time of hole processing. It is a principal part expansion partial notch sectional view which shows the state of the spring connection member at the time of female thread cutting.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
In FIG. 1 to FIG. 9, reference numeral 1 denotes a drill / tapping device, which comprises a balance arm 2 and a tool unit 3 connected to the balance arm 2. The balance arm 2 has a support column 4 that is erected and fixed on a sufficiently strong base, frame or the like (not shown), and a beam holder 5 is fixed to the support column 4. The beam holder 5 is configured to be position-adjustable along the column 4. A rotating shaft 6 extends vertically and is rotatably attached to the beam holder 5, and a first beam 7 extending horizontally is integrally connected to the rotating shaft 6. Thus, the first beam 7 is configured to be rotatable in the direction of the arrow Y1 in FIG. 4, that is, in the horizontal plane. Further, a second beam 9 is connected to the tip of the first beam 7 via a rotation shaft 8 extending vertically upward, and this second beam 9 has the rotation shaft 8 as a fulcrum in the direction of arrow Y2 in FIG. That is, it is configured to be rotatable in a horizontal plane.

  The second beam 9 includes an elbow 9a fitted and supported on the rotary shaft 8, and two links 9b and 9c that are pivotally supported by the elbow 9a so as to be rotatable in a vertical plane, and are arranged in parallel. Each of the links 9b and 9c is composed of a tool holder 9d that pivotally supports the ends of the links 9b and 9c in a vertical plane. With this structure, the second beam 9 forms a parallel link. As shown in FIGS. 5 and 6, the link 9b and the link 9c are relatively relative to each other, and the tool holder 9d is parallel to the elbow 9a. It is configured to be able to turn in a vertical plane while maintaining.

  A plate-like stopper plate 10 is fixed to the elbow 9a so as to extend in parallel with the links 9b and 9c. A stopper block 11 is attached to the lower end of the stopper plate 10, and a stopper bolt 12 is screwed to the stopper block 11 below the tool holder 9d. As shown in FIG. 5, the second beam 9 can be swung downward until it abuts against the stopper bolt 12, and the second beam 9 is adjusted by turning the stopper bolt 12 to adjust its protruding amount. Nine bottom dead centers can be set arbitrarily. Further, the stopper bolt 12 has a hollow hole 12a formed through the axis thereof, and a lift 13 is press-fitted and fixed therein. The lift 13 is a release device for a camera, and the tip pin 13a can be protruded by operating a dedicated controller (not shown). As shown in FIG. 6, the second beam 9 can be lifted by the protruding operation of the pin 13 a of the lift 13. Although FIG. 6 shows a state in which the second beam 9 is pushed up by the lift 13, the second beam 9 can be swung further upward if the tool unit 3 is held and operated.

  The stopper plate 10 is provided with a spring connecting member 14 extending in the vertical direction, and tension springs 15a and 15b are connected to both ends of the spring connecting member 14, respectively. The tension springs 15a and 15b are connected to the links 9b and 9c, respectively. The tension spring 15a can be urged to turn the second beam 9 upward by the tension force, and the tension spring 15B is The pulling force can bias the second beam 9 to turn downward. The spring connecting member 14 is disposed so as to be fitted in a groove 16 a of the adjustment plate 16 fixed to the stopper plate 10, and is always fixed between the stopper plate 10 and the adjustment plate 16. One of the screws for fixing the adjusting plate 16 to the stopper plate 10 is a butterfly bolt 17. By loosening the butterfly bolt 17, the spring connecting member 14 can move in the vertical direction along the groove 16a. It is configured. Accordingly, the spring connecting member 14 is positioned and fixed at an arbitrary position in the vertical direction, and the tensile force applied to the second beam 9 by the tension springs 15a and 15b can be adjusted.

  The tension spring 15a obtains a thrust load (axial load acting on the tool 25) to be applied to the tool 25, which will be described later, when female threading is performed with the spring connecting member 14 moved to the upper limit position and fixed. The performance that can be obtained is adopted. In the internal thread cutting process, the tap as the tool 25 bites the workpiece and advances while cutting the internal thread, and it is necessary to reverse the tap about once every 2 to 3 rotations in the internal thread cutting direction. Therefore, the thrust load applied to the tool 25 may be small. Otherwise, especially when reversing the tap, the tap does not return along the screw so that it can be cut by then, and it may bite into the workpiece. Accordingly, the tension spring 15a is configured to appropriately reduce the thrust load due to the weight of the tool unit 3 at the upper limit position of the spring coupling member 14. Further, the tension spring 15b has a performance capable of obtaining a thrust load to be applied to the tool 25 described later when drilling in a state where the spring connecting member 14 is moved to the lower limit position and fixed. . In drilling, unless the drill serving as the tool 25 is pressed against the workpiece with a corresponding thrust load, the drill escapes from the drilling position in the initial stage or easily breaks due to the impact of cutting resistance during drilling. Accordingly, the tension spring 15b is configured so that an appropriate thrust load can be added to the thrust load due to the weight of the tool unit 3 at the lower limit position of the spring connecting member 14.

  On the other hand, the tool unit 3 has a motor mount 18 attached integrally with the tool holder 9d. As shown in FIG. 7, the motor mount 18 has an AC servo motor 19 (hereinafter referred to as an example of a rotational drive source). The motor 19 is simply fixed. A hollow shaft-shaped tool holder 21 is rotatably connected to the drive shaft 19a of the motor 19 via a coupling 20, and a collet holder 22 is integrally rotatable to the tool holder 21. Is retained. The collet holder 22 is always secured by a steel ball 23 provided in the lower part of the tool holder 21, but the collar 24 holding the steel ball 23 is released upward to enable the steel ball 23 to operate. Thus, it is configured to be removable from the tool holder 21. At the tip of the collet holder 22, a tool 25 such as a drill for drilling holes or a tap for internal thread cutting is rotatably held integrally. The motor 19 is provided with an encoder 19b. The encoder 19b is configured to generate a signal corresponding to the number of rotations of the drive shaft 19a of the motor 19. The encoder 19b is connected to a controller (not shown) for motor drive control. These motors 19 to 25 are arranged on a coaxial line, and are configured to be always kept in a posture perpendicular to the axis by the action of the parallel link of the second beam 9.

  The tool unit 3 is coupled to the tool holder 9d in a posture perpendicular to the axis, that is, a posture in which the axis of the tool 25 is in the vertical direction. For this reason, the combination of the horizontal turning of the first and second beams 7 and 9 of the balance arm 2 and the vertical turning of the second beam 9 allows the vertical movement of the balance arm 2 while maintaining the vertical axis. It is configured.

  The drill / tapping device 1 performs a vertical hole drilling or female threading on a workpiece as can be seen from the posture of the tool unit 3 held by the balance arm 2. As a first working example, an example of drilling is shown below.

  When drilling the workpiece W, a drill is held as the tool 25 in the tool holder 21, and the spring connecting member 14 is slid and fixed to the lower limit position as shown in FIG. As a result, the lower tension spring 15b is urged so as to pull down the link 9c. At the time of machining, in addition to the thrust load due to the weight of the tool unit 3 or the like, a thrust load due to the force of the tension spring 15b is applied to the tool 25. 25 can be pressed against the workpiece W. In this state, the tool unit 3 is operated to place the tip of the tool 25 at the hole machining position of the workpiece W. At this time, the first beam 7 and the second beam 9 are set in a horizontal turning state in which the angle θ in plan view is about 90 °, and the links 9b and 9c of the second beam 9 extend substantially in the horizontal direction. Is set as follows.

  Thus, when the start switch (not shown) of the tool unit 3 is turned on and the motor 19 is driven, the tool holder 21 to the tool 25 (drill) rotate via the coupling 20. At this time, since a thrust load is applied to the tool 25 by its own weight such as the tool unit 3 and the force of the tension spring 15b, the tool 25 perforates the workpiece W by rotation. During the drilling, the tool unit 3 and the balance arm 2 are placed in a free state. That is, the operator does not grip the tool unit 3 or restrict the movement of the balance arm 2.

  During drilling, a complex drag acts on the tool 25 due to intertwining of various factors such as the biting of chips, the shape of the tool 25 itself, the composition of the workpiece W, and the torque ripple inherent to the motor 19. When such a drag force acts, the balance arm 2 receives this and performs a fine turning operation in the horizontal and vertical directions to finely adjust the position of the tool unit 3. As a result, the tool 25 is always automatically aligned to an optimum state without resisting the drag and punches the workpiece W. Further, the second beam is set to be almost horizontal with respect to the lowering of the tool unit 3 as the tool 25 drills into the workpiece W and the fine movement in the axial direction of the tool unit 3 due to the above-described drag. The tool 25 can be aligned by horizontally turning the first beam 7 and the second beam 9 with a slight force.

  Further, the ratio of the rotational load in the drag acting on the tool 25 is large, and the fluctuation during machining is fine and complicated. This rotational load is transmitted to the balance arm 2 as a rotational reaction force of the tool unit 3. At this time, since the balance arm 2 is set so that the first beam 7 and the second beam 9 form about 90 ° in plan view, this rotational reaction force is received by the first beam 7 at a pressure angle of 0 °. It becomes possible. As a result, the rotational movement of the first and second beams 7 and 9 due to the rotational reaction force, that is, the rotational load acting on the tool 25 does not occur, and the displacement of the tool unit 3 is prevented.

  In order to receive the rotational reaction force at a pressure angle of 0 °, the angle θ in plan view formed by the first beam 7 and the second beam 9 is optimally 90 °. Therefore, even if the angle θ is not strictly 90 °, the first and second beams 7 and 9 do not turn due to the rotational reaction force. In actual work, as described above, the balance arm 2 slightly turns in the horizontal direction in accordance with the drag and drilling received by the tool 25. However, the tool unit 3 is displaced due to the rotational reaction force at this level. There is no. If the balance arm 2 is sufficiently strong against the drag received by the tool 25, the angle θ in plan view formed by the first beam 7 and the second beam 9 is set within a range of 90 ± 5 °. There is no practical problem.

  When drilling is performed to a desired depth by the tool 25, the drive of the motor 19 is stopped and the controller of the lift 13 is operated to project the pin 13a. Accordingly, the second beam 9 is lifted upward, and the tool 25 can be extracted from the workpiece W.

Next, an example in which female threading is performed on a workpiece will be shown as a second work example.
When female threading is performed on the workpiece W, first, a pilot hole is formed in the workpiece W using a drill as the tool 25 as described above. Thereafter, the tool 25 is replaced with a tap, and the spring connecting member 14 is slid and fixed to the upper limit position as shown in FIG. As a result, the upper tension spring 15a urges the link 9b to be pulled up, and the thrust load applied to the tool 25 (tap) (load due to the weight of the tool unit 3 or the like) during processing is moderately reduced.

  Subsequently, the tool unit 3 is operated to position the tip of the tool 25 at the pilot hole entrance of the workpiece W. At this time, for the same reason as described above, the balance arm 2 and the second arm 7 are arranged so that the first and second beams 7 and 9 form about 90 ° in a plan view and the links 9b and 9c of the second beam 9 are substantially horizontal. Set the position / height relationship with the workpiece W. When the motor 19 is driven to rotate forward to rotate the tool 25 in the threading direction, the tool 25 forms a female thread along the pilot hole.

  In the process of female thread cutting, the controller 19 reads the output pulse of the encoder 19b, and when it is detected that the motor 19 has been normally rotated a predetermined number of times, the motor 19 is switched to reverse rotation. Thus, after the motor 19 is reversely driven by the number of rotations smaller than the number of rotations during normal rotation driving, the motor is returned to normal rotation driving again. This is repeated and threading with the tool 25 is performed to a desired depth. As a result, the tool 25 is unscrewed by a smaller amount of rotation each time a predetermined rotational threading is performed, so that the biting of the chips can be prevented and the screw can be molded for stability. Further, since the thrust load on the tool 25 due to the weight of the tool unit 3 and the like is appropriately reduced by the action of the tension spring 15a, the tool 25 is already formed in each of the threading and unscrewing of the tool 25. Can be rotated along. Therefore, it is possible to prevent the occurrence of a problem that the tool 25 is already formed and bites into the screw to cut another female screw.

  Also in this female threading process, from the beginning of biting into the pilot hole of the tool 25 to the end of female thread cutting, the self-aligning effect by the balance arm 2 and the tool unit 3 by the rotational reaction force are the same as in the above-described hole machining. The effect of preventing the positional deviation is obtained. For this reason, it is possible to prevent breakage of the tap and to reliably cut the female thread.

  As described above, the present drill / tapping device 1 prevents the pivoting of the balance arm 2 (position displacement of the tool unit 3) due to a pure rotational load acting on the tool 25 during drilling, and acts on the other tools 25. For example, a slight turning motion in the horizontal plane and the vertical plane of the balance arm 2 is allowed for a force to be moved, for example, a force to translate the tool 25, a bending moment, etc., and the tool unit 3 can be adjusted to an optimum position. It can be done. For this reason, it is possible to prevent the tool 25 from being broken by a complicated force acting during drilling, and to perform the hole machining reliably. In particular, when drilling holes and female screws with a diameter of φ2 mm or less by drilling and M2 or less by female threading, the breakage rate of drills and taps is increased. It is possible to prevent breakage of the tool 25 having a small diameter.

  In addition, as said tool 25, the drill tap which integrated the drill and the tap on the same axis | shaft can also be used, and a pilot hole processing and female threading processing may be continuously performed by one tool by this. . In the present embodiment, the tension springs 15a and 15b are exemplified as the first and second springs, but other springs such as a compression spring and a fluid spring can be adopted as the spring member used here. By connecting these springs to both ends of the spring connecting member 14 so as to urge the second beam from the up and down directions, the second position of the spring connecting member can be adjusted in the same manner as in the case of the tension springs 15a and 15b. The urging direction and urging force of the beam 9 can be adjusted.

DESCRIPTION OF SYMBOLS 1 Drill and tap processing apparatus 2 Balance arm 3 Tool unit 4 Support column 5 Beam holder 6 Rotating shaft 7 1st beam 8 Rotating shaft 9 2nd beam 9a Elbow 9b Link 9c Link 9d Tool holder 10 Stopper plate 11 Stopper block 12 Stopper bolt 13 Lift 14 Spring connecting member 15a Tensile spring 15b Tensile spring 16 Adjustment plate 17 Butterfly bolt 18 Motor mount 19 AC servo motor 20 Coupling 21 Tool holder 22 Collet holder 23 Steel ball 24 Color 25 Tool W Workpiece

Claims (5)

A first beam that can swivel in a horizontal plane, a second beam that is connected to the first beam so as to swivel in a horizontal plane and that can swivel in a vertical plane, and the second beam A drill unit that includes a tool unit provided with a tool that is supported by a rotation drive source and rotates, and drills or internally threads a workpiece with the tool unit,
A spring coupling member provided so as to be movable in the vertical direction and capable of being fixed at a desired position; a first spring supported at one end of the spring coupling member so as to be able to bias the second beam upward; A drill / tapping apparatus comprising: a second spring provided at the other end of the spring connecting member so as to be able to bias the second beam so as to pivot downward.   The drill / tapping apparatus according to claim 1, wherein the first beam and the second beam are always arranged at an angle of about 90 °.   The drill / tapping apparatus according to claim 1, wherein the second beam is provided so as to extend parallel to a horizontal plane.   The spring connecting member is always clamped and fixed between a stopper plate and an adjusting plate provided adjacent to the second beam, and is configured to be position-adjustable by loosening a screw that holds the adjusting plate on the stopper plate. The drill / tapping apparatus according to any one of claims 1 to 3.   The drill / tapping device according to claim 4, wherein the screw for fixing the adjustment plate to the stopper plate is a butterfly bolt.

Images