Drill bit machining apparatus

Abstract

The present application provides a drill machining device capable of detecting a decrease in holding force of temporarily holding a drill and preventing a decrease in efficiency of hole machining. The drill machining device includes a rotation shaft configured to rotate a drill held by a first holding portion; a tool post having a second holding portion configured to temporarily hold the drill when the drill held by the first holding portion is replaced; a driving mechanism configured to move the rotation shaft between a holding position at which the first holding portion can hold the drill temporarily held by the second holding portion and a position away from the drill; a detection unit configured to detect a driving current for driving the driving mechanism during movement of the first holding portion holding the drill temporarily held by the second holding portion and movement of the rotation shaft from the holding position to the position away from the drill; and a determination unit configured to determine a holding force of the temporary holding by the tool post based on the driving current detected by the detection unit.

Description

Technical Field

[0001] This invention relates to a drill bit processing apparatus for hole drilling using a drill bit. Background Technology

[0002] Drill bit processing apparatuses that utilize drill bits to perform hole drilling on printed circuit boards and the like are known in the past. For example, as described in Patent Document 1, the drill bit processing apparatus includes a tool post that temporarily holds (hereinafter referred to as "temporarily holds") the old drill bit and the new drill bit when changing drill bits.

[0003] [Existing technical documents] [Patent Literature] [Patent Document 1] Japanese Patent Application Publication No. 2016-43432. Summary of the Invention

[0004] [The problem the invention aims to solve] However, if the tool post used to temporarily hold the drill bit is repeatedly removed and installed, its holding force will decrease due to deterioration over the years. When changing drill bits in a drill bit processing device, the new drill bit is installed on the spindle in a state where it is temporarily held by the tool post. If the holding force of the tool post decreases at this time, the new drill bit will be unstable and cannot be installed on the spindle. As a result, the drill bit change operation cannot be performed, the drilling process is interrupted, and thus the efficiency of drilling operations using the drill bit processing device is reduced.

[0005] The purpose of this invention is to provide a drill bit processing device that can detect a decrease in the holding force of a temporarily held drill bit and prevent a decrease in the efficiency of hole drilling.

[0006] [Problem-solving methods] To achieve the above objectives, the drill bit processing apparatus of the present invention is characterized by comprising: a rotating shaft having a first holding portion for holding a drill bit, thereby rotating the drill bit held by the first holding portion; a tool post coaxial with the rotating shaft and having a second holding portion for temporarily holding the drill bit when the drill bit held by the first holding portion is replaced; and a drive mechanism that enables the rotating shaft to move along the axial direction of the rotating shaft between a holding position in which the first holding portion holds the drill bit temporarily held by the second holding portion and a divergent position opposite to the holding position; the drill bit processing apparatus further comprises: a detection unit that detects the drive current driving the drive mechanism during the process of the first holding portion holding the drill bit temporarily held by the second holding portion and the rotating shaft being moved from the holding position to the divergent position by the drive mechanism; and a determination unit that determines the holding force of the tool post based on the drive current detected by the detection unit.

[0007] [The effects of the invention] According to the present invention, it is possible to detect a decrease in the holding force of the temporarily held drill bit, thereby preventing a decrease in the efficiency of hole drilling. Attached Figure Description

[0008] [ Figure 1 [Illustration of the drill bit processing apparatus in this embodiment]

[0009] [ Figure 2 This is a longitudinal cross-sectional view of the main parts of the spindle and tool post, showing that the drill bit is temporarily held by the tool post while the spindle is in a reverse position. Figure 2 (A) and maintaining position ( Figure 2 A cross-sectional view of the main part of the state of (B).

[0010] [ Figure 3 [] is a block diagram representing the electrical configuration of a drill bit processing device.

[0011] [ Figure 4 This is a longitudinal sectional view of the main parts of the shaft and tool post, showing the state of the shaft holding the drill bit in the holding position. Figure 4 (A) and the state in which the rotating shaft moves from the holding position to the diverging position. Figure 4 (B) Main section view.

[0012] [ Figure 5 [ ] is a timing diagram representing the vertical drive current of the shaft, showing the appropriate holding force of the tool post ( ). Figure 5 (A) and the state of insufficient retention ( Figure 5 The timing diagram of (B).

[0013] [Explanation of Labels in the Attached Image] 1: Drill bit processing device 10:Printed substrate 11: Device base 12: Processing table 13: Gantry-type column 15: Cross slider 16: Shaft 17: Drill bit 17A: Outer Peripheral Surface 18: Secondary clamp 19: Supply tool column 20: Discharge tool column 21: Drill bit box 22: Drill Bit Inspection Tool 25: Control device 26: Display Section 27: Memory Department 30: Ring 31: Rotor shaft 31A: First conical surface 31B: Top surface 32: Collet chuck (first holding part) 32A: Second cone surface 32B: Slit 32C: Inner circumferential surface 33: Spring 34: Guide sleeve 35: Piston rod 36: Pressing mechanism 41: Vertical drive control unit for rotating shaft 42: Shaft Control Unit 43: XY Direction Drive Control Unit 44: Judgment Department 45: Vertical drive mechanism of rotating shaft 46: XY Direction Drive Mechanism 47: Position Detection Sensor 51: Sleeve 51a: Small diameter portion 52: Holder 53: Spring 56a: Small diameter portion 56b: Large diameter part 57a: Small diameter portion 57b: Large diameter part 57c: Fitting Hole 57d: Storage Hole 57e: Slit IS: Vertical drive current of the shaft. Detailed Implementation

[0014] [Composition of Drill Bit Processing Equipment] like Figure 1 As shown, the drill bit processing apparatus 1 of the present invention includes an apparatus base 11, a processing table 12, and a gantry column 13. The processing table 12 is driven on the apparatus base 11 by an XY direction drive mechanism 46 (see reference). Figure 3 Driven along the X direction. Multiple printed circuit boards 10, which become the workpiece, are placed on the processing table 12 (two in this embodiment).

[0015] A gantry column 13 is mounted on the device base 11. The gantry column 13 is configured to span the machining table 12, and a cross slide 15 driven along the Y direction by an XY direction drive mechanism 46 is mounted on one of the vertical surfaces of the gantry column 13. Multiple rotating shafts 16 are provided on the cross slide 15.

[0016] The rotating shafts 16 correspond to the printed circuit boards 10 placed on the processing table 12 and are mounted in a manner that allows them to slide relative to the gantry column 13. The multiple rotating shafts 16 are connected by a rotating shaft vertical drive mechanism 45 (see reference 12). Figure 3 They are driven synchronously along the vertical direction (Z direction).

[0017] A drill bit 17 is held on a pivot 16. The drill bit 17 is used to drill holes in the printed circuit board 10. A secondary chuck 18 is mounted on the pivot 16. The secondary chuck 18 moves together with the pivot 16 in the Z direction. Furthermore, a feed tool post 19, a discharge tool post 20, a drill bit holder 21, and a drill bit inspector 22 are respectively provided on the processing table 12. The drill bit holder 21 stores new and old drill bits separately. The drill bit inspector 22 has the function of detecting the diameter or tip position of the drill bit 17 held on the pivot 16, and is activated by inserting the drill bit 17 from above. One feed tool post 19, one discharge tool post 20, one drill bit holder 21, and one drill bit inspector 22 are each provided near the printed circuit board 10 to be processed, corresponding to the pivot 16.

[0018] Each part of the drill bit processing apparatus 1 is controlled by a control device 25. The control device 25 is implemented, for example, by a programmable processor. A display unit 26 is connected to the control device 25. The display unit 26 displays various information to be transmitted to the operator.

[0019] The control device 25 includes a memory unit 27. The memory unit 27 stores programs, display data, and predetermined thresholds, for example, non-volatile memory. The control device 25 detects the drive current of the vertical drive mechanism 45 of the shaft 16 when it is pulled from the feed tool post 19 to the drill bit 17, and determines the holding force of the feed tool post 19 on the drill bit 17 based on the detected drive current. The control performed by the control device 25 will be described below.

[0020] [Composition of pivot 16] like Figure 2 (A) and Figure 2 As shown in (B), the rotating shaft 16 includes a rotor shaft 31, a collet 32 ​​(first holding part), a spring 33, a guide sleeve 34, and a piston rod 35. The rotating shaft 16 is controlled by the control device 25 and is integrated with the motor (not shown). The rotor shaft 31 is supported by bearings (not shown) in a rotatable manner. The rotor shaft 31 is coupled to a rotor (not shown). The rotor can rotate relative to the stator coils (not shown). If power is supplied to the stator coils under the control of the control device 25, the rotor and rotor shaft 31 rotate as a single unit. Thus, the rotor shaft 31 transmits rotation from the motor.

[0021] The rotor shaft 31 has a first conical surface 31A formed on its inner circumferential surface. The first conical surface 31A is a conical surface whose inner diameter expands toward the lower end of the rotor shaft 31 (the side where the drill bit 17 is located). The collet chuck 32 is disposed at the lower end of the rotor shaft 31, specifically at the position surrounded by the inner circumferential surface of the rotor shaft 31. The spring 33 is disposed inside the rotor shaft 31.

[0022] The collet chuck 32 is engaged with the piston rod 35 via a guide sleeve 34. The guide sleeve 34 is fitted in a manner that allows sliding relative to the axial direction (Z direction) of the rotor shaft 31. Therefore, the radial movement of the piston rod 35 is restricted. Furthermore, the rotor shaft 31, the collet chuck 32, and the drill bit 17 are arranged coaxially. Also, when the collet chuck 32 holds a new drill bit 17, the supply tool post 19 is arranged coaxially with the rotor shaft 31 and the collet chuck 32. Therefore, hereinafter, the axial direction of the rotor shaft 31, the collet chuck 32, the drill bit 17, and the supply tool post 19 will be simply referred to as the "axial direction". Furthermore, hereinafter, the side of the axial direction from the rotor shaft 31 toward the drill bit 17 mounted on the collet chuck 32 will be defined as "below", and the opposite side will be defined as "above".

[0023] Spring 33 is disposed inside rotor shaft 31. Specifically, spring 33 is disposed between the top contact surface 31B, which is located on the inner circumference side of rotor shaft 31 and near the lower end, and guide sleeve 34. Thus, spring 33 pushes collet 32 ​​toward the closed state described below, i.e., the upper end side in the axial direction (opposite to drill bit 17), via guide sleeve 34.

[0024] The piston rod 35 is coupled to a pressing mechanism (not shown). The pressing mechanism, for example, is a cylinder that, against the push of the spring 33, presses the piston rod 35 towards the open state, i.e., the lower end in the axial direction, as described below. When the pressing mechanism presses the piston rod 35, the collet chuck 32 moves towards the lower end in the axial direction. Furthermore, when the pressing mechanism releases the pressure on the piston rod 35, the collet chuck 32 moves towards the upper end in the axial direction due to the push of the spring 33.

[0025] [Composition of collet chuck 32] The collet chuck 32 has a second conical surface 32A, a plurality of slits 32B arranged parallel to the axial direction, and an inner circumferential surface 32C that mates with the outer circumferential surface of the drill bit 17. The second conical surface 32A is formed on the outer circumferential surface of the collet chuck 32 and extends toward the lower end of the collet chuck 32. The second conical surface 32A is in contact with the first conical surface 31A of the rotor shaft 31.

[0026] When the collet chuck 32 is pressed downwards by the pressing mechanism via the piston rod 35, it protrudes from the lower end of the rotor shaft 31 against the spring push of the spring 33. The second conical surface 32A of the collet chuck 32, protruding from the lower end of the rotor shaft 31, is opposite to the first conical surface 31A, and its radial dimension is enlarged, thus entering an open state. Figure 2 (as shown in (A)). The collet 32 ​​expands through the inner diameter of the inner circumferential surface 32C and moves away from the outer circumferential surface of the drill bit 17, thus releasing the hold of the drill bit 17.

[0027] On the other hand, when the collet 32 ​​is released from the pressing mechanism via the piston rod 35, as described above, it is pushed back from the upper end of the spring 33 in the axial direction. Therefore, the collet 32 ​​is inserted into the rotor shaft 31, whereby the second conical surface 32A is pressed against the first conical surface 31A, reducing its radial dimension and entering a closed state. Figure 4 (A) and Figure 4 (as shown in (B)). The collet 32 ​​narrows through the inner diameter of the inner circumferential surface 32C and comes into close contact with the outer circumferential surface of the drill bit 17, holding the drill bit 17 downward. "Downward" means that the front end of the drill bit 17, in which the drill bit is formed, is located below, and the base end held by the collet 32 ​​is located above.

[0028] By holding the drill bit 17 in the collet chuck 32, rotation is transmitted from the motor of the spindle 16 to the drill bit 17 via the rotor shaft 31 and the collet chuck 32. In the drill bit processing apparatus 1, when replacing the drill bit 17 held by the collet chuck 32 with a new drill bit, the supply tool post 19 temporarily holds the drill bit 17. "Temporarily held" refers to the temporary holding during the drill bit replacement operation in the drill bit processing apparatus 1.

[0029] [Composition of Drill Bit 17] In this embodiment, the drill bit 17 is fitted with a ring 30 on its outer peripheral surface. The ring 30 is positioned between the front end of the drill bit 17 where the drill bit is formed and the base end held by the collet 32. The ring 30 is, for example, formed of a hard synthetic resin.

[0030] [Composition of Supply Tool Column 19] like Figure 2 (A) and Figure 2 As shown in (B), the supply tool post 19 is composed of a sleeve 51, a retainer 52, and a spring 53. The supply tool post 19 is located below the rotating shaft 16. Furthermore, the discharge tool post 20 has the same structure as the supply tool post 19, and its description is omitted.

[0031] A small-diameter portion 56a and a large-diameter portion 56b are formed on the inner circumferential surface of the sleeve 51. The small-diameter portion 56a is an opening located at the upper end of the sleeve 51 in the axial direction. The large-diameter portion 56b is coaxially connected to the end of the small-diameter portion 51a, and its inner diameter is larger than that of the small-diameter portion 51a.

[0032] A retainer 52 is disposed inside the sleeve 51. A small-diameter portion 57a ​​and a large-diameter portion 57b are formed on the outer peripheral surface of the retainer 52. The outer diameter of the large-diameter portion 57b is slightly smaller than that of the large-diameter portion 56b of the sleeve 51, and its axial length is shorter than that of the large-diameter portion 56b of the sleeve 51. The small-diameter portion 57a ​​is coaxially connected to the end of the large-diameter portion 57b. The outer diameter of the small-diameter portion 57a ​​is slightly smaller than that of the small-diameter portion 56a of the sleeve 51, and its axial length is longer than that of the small-diameter portion 56a of the sleeve 51. The small-diameter portion 57a ​​protrudes from the upper end of the sleeve 51.

[0033] A fitting hole 57c (second holding portion) and a receiving hole 57d are formed inside the retainer 52. The fitting hole 57c is an opening located at the upper end of the retainer 52 in the axial direction. The receiving hole 57d is coaxially connected to the fitting hole 57c and has an inner diameter smaller than the fitting hole 57c. Furthermore, a plurality of slits 57e are formed in the small-diameter portion 57a ​​of the retainer 52, which extend radially through a portion of the fitting hole 57c and the receiving hole 57d (see reference). Figure 4 (B)

[0034] The engagement hole 57c engages with the ring 30 of the drill bit 17. Thus, the retainer 52 temporarily holds the drill bit 17. In other words, the engagement force between the engagement hole 57c and the ring 30 is the holding force of the tool post 19 on the drill bit 17. If the retainer 52 deteriorates over time, for example, due to wear or other wear on the surface of the engagement hole 57c, the holding force of the drill bit 17 decreases. The front end of the drill bit 17 is received in the receiving hole 57d. Furthermore, the orientation in which the retainer 52 temporarily holds the drill bit 17 is "downward," the same orientation in which the collet 32 ​​holds the drill bit 17.

[0035] Spring 53 is disposed inside sleeve 51 and between retainer 52 and processing table 12. Spring 53 pushes retainer 52 upward. By being pushed by spring 53, the upper end of the large diameter portion 57b of retainer 52 abuts against the upper end of the large diameter portion 56b of sleeve 51.

[0036] When the retainer 52 is pressed from above, the retainer 52 descends against the spring force of the spring 53. In other words, the small diameter portion 57a ​​of the retainer 52 is pressed into the interior of the sleeve 51. When the retainer 52 is pressed from above, the spring 53 is compressed, pushing the retainer 52 upward.

[0037] [Electrical configuration of control device 25] Then, use Figure 3 The electrical configuration of the control device 25 will be explained. For example...Figure 3 As shown, the control device 25 controls each part of the drill bit processing device 1 by reading and executing the control program pre-memorized in the memory unit 27. The control device 25 includes a vertical drive control unit 41 (detection unit), a spindle control unit 42, an XY direction drive control unit 43, and a determination unit 44 (determination unit).

[0038] The shaft control unit 42 controls the motor and pressing mechanism of the shaft 16. In other words, the shaft control unit 42 controls the rotation of the rotor shaft 31 and the opening and closing of the collet chuck 32.

[0039] The XY direction drive control unit 43 controls the drive of the XY direction drive mechanism 46. As described above, the XY direction drive mechanism 46 drives the machining table 12 along the X direction and drives the cross slide 15, on which the rotating shaft 16 is provided, along the Y direction. In other words, the XY direction drive mechanism 46 changes the relative position of the rotating shaft 16 and the machining table 12 in the X and Y directions.

[0040] The vertical drive control unit 41 controls the drive of the vertical drive mechanism 45. The vertical drive mechanism 45 is a mechanism that moves the shaft 16 along the axial direction, and may be, for example, a pneumatic cylinder. The vertical drive mechanism 45 can move the shaft 16 between the holding position described below and a diverging position opposite to the holding position.

[0041] When changing the drill bit 17 held by the collet 32, the spindle vertical drive control unit 41 operates the spindle vertical drive mechanism 45. More specifically, when the collet 32 ​​holds the drill bit 17 temporarily held by the supply tool post 19, the spindle vertical drive control unit 41 performs feedback control on the drive current (hereinafter referred to as the spindle vertical drive current) that drives the spindle vertical drive mechanism 45, causing the spindle 16 to move in the direction (upward) from which the drill bit 17 is pulled from the supply tool post 19.

[0042] The vertical drive control unit 41 calculates the amount of movement of the shaft 16 per unit time based on the position of the shaft 16 in the axial direction detected by the position detection sensor 47. The position detection sensor 47 is, for example, a magnetic sensor. Furthermore, not limited to this, when the vertical drive mechanism 45 is an electric cylinder, the amount of movement of the shaft 16 per unit time can also be calculated from the rotation angle of the rotating body constituting the electric cylinder. In this case, a rotation angle sensor is provided to detect the rotation angle of the rotating body. The rotation angle sensor is, for example, a rotary encoder.

[0043] The vertical drive control unit 41 performs feedback control on the vertical drive mechanism 45, for example, by ensuring that the movement of the shaft 16 per unit time approaches the target movement. More specifically, the vertical drive control unit 41, as feedback control, monitors, for example, the movement of the shaft 16 per unit time. When the movement per unit time is less than the target movement, it increases the vertical drive current; when the movement per unit time is greater than the target movement, it decreases the vertical drive current. The target movement is pre-memorized in the memory unit 27.

[0044] The vertical drive control unit 41 also functions as a detection unit for detecting the vertical drive current of the shaft. More specifically, the vertical drive control unit 41 detects the vertical drive current of the shaft 16 when it moves the shaft 16 toward the vertical drive mechanism 45 in the direction from the supply tool post 19 to pull the drill bit 17. The vertical drive current detected by the vertical drive control unit 41 is then output to the determination unit 44.

[0045] The determination unit 44 determines the holding force of the temporary holding mechanism using the supply tool post 19 based on the vertical drive current of the shaft detected by the vertical drive control unit 41. Furthermore, the determination of the holding force by the determination unit 44 will be explained below.

[0046] [Drill bit replacement operation in drill bit processing unit 1] Reference Figure 2 , Figure 4 and Figure 5 The drill bit replacement operation in drill bit processing device 1 is described.

[0047] When performing drill bit replacement operations on the drill bit processing apparatus 1, the first step is to discharge the used old drill bit 17 into the discharge tool post 20. In this discharge step, the control device 25 drives the XY direction drive mechanism 46 under the control of the XY direction drive control unit 43, causing the processing table 12 to move along the X direction and the rotating shaft 16 to move along the Y direction, thereby aligning the discharge tool post 20 with the position of the rotating shaft 16.

[0048] Subsequently, the control device 25, under the control of the vertical drive control unit 41, drives the vertical drive mechanism 45 of the shaft, causing the shaft 16 to descend to the position where the ring 30 of the old drill bit 17 is engaged in the engagement hole of the discharge tool post 20. After the ring 30 is engaged in the engagement hole of the discharge tool post 20, the control device 25, under the control of the shaft control unit 42, changes the collet chuck 32 from the closed state to the open state. Thus, the collet chuck 32 releases the old drill bit 17 from its holding position.

[0049] After the collet chuck 32 releases the old drill bit 17, the control device 25 drives the vertical drive mechanism 45 of the spindle via the control of the vertical drive control unit 41, causing the spindle 16 to move away from the discharge tool post 20. By releasing the collet chuck 32 from the drill bit 17, the old drill bit 17 is held by the discharge tool post 20. Thus, the discharge of the old drill bit 17 is completed. After the drill bit replacement operation, the old drill bit 17 held by the discharge tool post 20 is discarded.

[0050] Following the discharge step, an assembly step is performed to hold the new drill bit 17 in the collet 32. During the assembly step, the operator engages the ring 30 of the new drill bit 17 with the engagement hole 57c of the supply tool post 19. In other words, the supply tool post 19 temporarily holds the new drill bit 17 downwards. Then, the control device 25 drives the XY direction drive mechanism 46 via the control of the XY direction drive control unit 43, causing the machining table 12 to move along the X direction, the spindle 16 to move along the Y direction, and aligning the supply tool post 19 with the coaxial position of the spindle 16. Figure 2 (as shown in position (A)). Furthermore, at this time, the control device 25, under the control of the shaft control unit 42, changes the collet chuck 32 from a closed state to an open state.

[0051] Subsequently, the control device 25 drives the vertical drive mechanism 45 of the shaft through the control of the vertical drive control unit 41, so that the shaft 16 is lowered to the position where the collet chuck 32 can hold the new drill bit 17 temporarily held by the supply tool post 19. Figure 2 (as shown in position (B)). After the shaft 16 descends to the holding position, the small diameter portion 57a ​​of the retainer 52 is pressed into the interior of the sleeve 51. As the retainer 52 is pressed, the spring 53 is compressed, which in turn pushes the retainer 52 upward.

[0052] After the spindle 16 is lowered to the holding position, the control device 25, through the control of the spindle control unit 42, changes the collet chuck 32 from the open state to the closed state. This reduces the radial dimension of the collet chuck 32, thus holding the new drill bit 17 ( Figure 4 (as shown in position (A)). At this time, since the collet 32 ​​is inserted into the rotor shaft 31, the pressure from the rotating shaft 16 to the retainer 52 is released. As a result, the retainer 52 returns to its initial position by the push of the spring 53.

[0053] After the collet chuck 32 is in the closed state and holds the new drill bit 17, the control device 25 drives the vertical drive mechanism 45 of the spindle through the control of the vertical drive control unit 41, so that the spindle 16 moves from the holding position to the departing position. Figure 4(as shown in position (B)). In other words, the vertical drive mechanism 45 pulls out the new drill bit 17 temporarily held by the fitting hole 57c by moving the shaft 16 upward. Thus, the new drill bit 17 is held by the drill bit processing device 1, completing the replacement operation.

[0054] When the spindle 16 moves from the holding position to the departing position, the control device 25 detects the spindle vertical drive current via the spindle vertical drive control unit 41. Then, the determination unit 44 determines the holding force of the temporary holding position using the supply tool post 19 based on the spindle vertical drive current detected by the spindle vertical drive control unit 41. More specifically, the determination unit 44 determines that the holding force of the supply tool post 19 is appropriate when the peak value of the spindle vertical drive current exceeds a predetermined threshold, and determines that the holding force of the supply tool post 19 is insufficient when the spindle vertical drive current is below the predetermined threshold. The predetermined threshold is, for example, set as the lower limit value of the spindle vertical drive current detected by the spindle vertical drive control unit 41 when the position of the drill bit 17 temporarily held by the supply tool post 19 is stable.

[0055] Figure 5 (A) is a timing diagram of the drive current when the holding force of the supply tool post 19 is appropriate. The determination unit 44 monitors the vertical drive current IS of the shaft from the moment t0 when the shaft 16 begins to move from the holding position to the departing position. In order to pull out the new drill bit 17 temporarily held by the supply tool post 19, as described above, the vertical drive control unit 41 increases the vertical drive current IS of the shaft.

[0056] The vertical drive mechanism 45 moves the shaft 16 against the holding force (fitting force) of the supply tool post 19 (fitting hole 57c). Therefore, when the holding force of the supply tool post 19 is strong, or in other words, when the resistance is high when pulling in the new drill bit 17, the movement of the shaft 16 per unit time is less. Consequently, through feedback control of the vertical drive control unit 41, the vertical drive current IS increases. From the moment t0 when the shaft 16 begins to move, the holding force of the supply tool post 19 takes effect, and the vertical drive current IS rises to its peak value P1.

[0057] After the vertical drive current IS of the spindle rises to its peak value P1, the holding force of the tool post 19 gradually weakens. In other words, the resistance when pulling out the new drill bit 17 gradually decreases, and the amount of movement of the spindle 16 per unit time gradually increases. As a result, through the feedback control of the vertical drive control unit 41, the vertical drive current IS of the spindle decreases from its peak value P1.

[0058] like Figure 5As shown in (A), when the peak value P1 of the vertical drive current IS of the rotating shaft exceeds a predetermined threshold, the determination unit 44 determines that the holding force of the supply tool post 19 is appropriate (determined to be normal). When the condition is determined to be normal, the control device 25 starts drilling the printed circuit board 10 through the drill processing device 1.

[0059] Figure 5 (B) is a timing diagram of the drive current when the holding force of the supply tool post 19 is insufficient. The determination unit 44 monitors the vertical drive current IS of the shaft from the moment t0 when the shaft 16 begins to move from the holding position to the departing position. In order to move the shaft 16 against the holding force (fitting force) of the supply tool post 19 (fitting hole 57c), the vertical drive current IS rises to a peak value P2. In this case, the holding force of the supply tool post 19 is weaker than in the proper case. In other words, compared with the case where the holding force of the supply tool post 19 is appropriate, the resistance when pulling out the new drill bit 17 is smaller, and the amount of movement of the shaft 16 per unit time is greater. As a result, the peak value P2 of the vertical drive current IS of the shaft also decreases.

[0060] like Figure 5 As shown in (B), when the peak value P2 of the vertical drive current IS of the shaft is below a predetermined threshold, the determination unit 44 determines that the holding force of the supply tool post 19 is insufficient (error determination). In the case of an error determination by the determination unit 44, the control device 25 issues a warning, such as issuing an error sound or displaying an error on the display unit 26, and stops the operation of the drill bit processing device 1. The operator recognizes the reduced holding force of the supply tool post 19 through the stop of the drill bit processing device 1 (device stop) and the error determination warning. After the operator replaces the supply tool post 19, the stop of the drill bit processing device 1 by the control device 25 is lifted, allowing it to operate again.

[0061] [Effects and Effects of the Examples] According to the above embodiment, during the process of moving the shaft 16 from the holding position to the departing position, the vertical drive current of the shaft is detected, and based on the detected vertical drive current, the determination unit 44 determines the holding force of the supply tool post 19, thus allowing the user to recognize that the holding force of the supply tool post 19 on the drill bit 17 has decreased. The user who recognizes the decrease in the holding force of the supply tool post 19 performs maintenance such as replacing the supply tool post 19. If maintenance is not performed and the supply tool post 19 with decreased holding force is continued to be used, the drill bit 17 cannot be replaced, and the efficiency of drilling using the drill bit processing apparatus 1 decreases. In contrast, with the drill bit processing apparatus 1, the user can perform maintenance before the drill bit 17 cannot be replaced. Therefore, the decrease in the efficiency of drilling using the drill bit processing apparatus 1 can be prevented.

[0062] Furthermore, in the drill bit processing apparatus 1, the control device 25 issues a warning and stops the drill bit processing apparatus 1 when the peak value of the vertical drive current of the spindle exceeds a predetermined threshold. Therefore, the user can reliably identify the reduction in the holding force of the supply tool post 19 on the drill bit 17. As a result, the use of the supply tool post 19 with reduced holding force on the drill bit 17 can be prevented, thus preventing a decrease in the efficiency of hole drilling performed using the drill bit processing apparatus 1.

[0063] Furthermore, in the above embodiment, the configuration of the supply tool post 19 that temporarily holds the ring 30 of the drill bit 17 is shown, but it is not limited to this. It is also possible to use a drill bit 17 without the ring 30 and temporarily hold it by fitting it into the outer peripheral surface of the drill bit 17. Also, the configuration of the vertical drive mechanism for the rotating shaft is not limited to the above-described electric cylinder. It can be any actuator (e.g., a solenoid) that can drive the rotating shaft in the vertical direction and detect the drive current.

[0064] Furthermore, in this embodiment, when the peak value of the vertical drive current of the rotating shaft is below a predetermined threshold, the control device 25 issues both a warning and stops the device. However, the present invention is not limited to this, and at least one of these actions is sufficient.

[0065] The above embodiments are illustrative of the present invention and are not intended to limit the scope of the invention to these embodiments. Those skilled in the art can make appropriate modifications without departing from the spirit of the invention.

Claims

1. A drill bit processing device, characterized in that... have: A rotating shaft having a first holding portion for holding a drill bit, thereby rotating the drill bit held by the first holding portion; A tool post, coaxial with the pivot, has a second retaining portion for temporarily holding the drill bit when the drill bit held by the first retaining portion is replaced; and A drive mechanism that enables the rotating shaft to move along the axial direction of the rotating shaft between a holding position where the drill bit is temporarily held by the second holding portion and a diverging position opposite to the holding position; The drill bit processing device also includes: The detection unit detects the drive current driving the drive mechanism during the process of the first holding part holding the drill bit temporarily held by the second holding part, and the drive mechanism moving the rotating shaft from the holding position to the diverging position. and The determination unit determines the holding force of the tool post based on the driving current detected by the detection unit.

2. The drill bit processing apparatus as described in claim 1, wherein... When the peak value of the drive current is below a predetermined threshold, the determination unit shall issue a warning or stop the device at least once.

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