JP5718128B2 - Drilling machine - Google Patents

Description

  The present invention relates to a drilling machine.

A conventional printed circuit board drilling machine, which is a drilling machine, will be described.
FIG. 8 is an overall perspective view of a first conventional printed circuit board drilling machine for punching a printed circuit board.
The table 2 is movably supported by guide means 3 disposed on the bed 1 and driven on the bed 1 in the X direction by a screw feed mechanism (not shown). On the upper surface of the table 2, a processing area 2a for placing a printed circuit board and a tool supply area 2b for supplying a drill used for processing are set.
The column 4 is fixed to the bed 1 so as to straddle the table 2. The cross slide 5 is movably supported by guide means 6 disposed on the column 4 and is driven on the column 4 in the Y direction by a screw feed mechanism (not shown) using a motor 7 as a drive source. The pair of saddles 8 is movably supported by guide means 9 disposed on the cross slide 5, and is driven in the Z direction by a screw feed mechanism (not shown) using a motor 10 as a drive source.
A pair of spindle units 11 is fixed to each saddle 8. The spindle unit 11 is formed of a housing fixed to the saddle 8 and supporting the spindle motor, and the spindle motor. A drill 12 is rotatably supported at the tip of the spindle motor.
The NC device 28 controls the motor of each axis.
Then, the printed circuit board is fixed to the processing area 2a of the table 2, the table 2 and the cross slide 5 are relatively moved in the X and Y directions to position the printed circuit board and the drill 12, and the saddle 8 is moved in the Z direction. Then, the printed circuit board is punched (Patent Document 1).

Next, the second prior art will be described.
When the moving speed of the drill 12 is increased, the machining efficiency can be improved. Therefore, instead of moving the saddle 8, there is a technique for improving the moving speed of the drill, that is, the machining speed by supporting the spindle motor movably in the Z direction by the housing and moving only the spindle motor. .
FIG. 9 is a partial front sectional view of a drill driving unit (hereinafter referred to as “main shaft”) in a conventional printed circuit board drilling machine in which only the spindle motor is moved during processing. Components having the same function are denoted by the same reference numerals and description thereof is omitted.
The housing 4 is fixed to the saddle 8. The cylindrical spindle motor 20 is positioned in the XY direction with respect to the housing 4 so that the axis O is in the Z direction, and can be moved in the axis O direction by the bearings 24.
The rotor shaft 21 of the spindle motor 20 is supported in the radial direction by a plurality of bearings 25 and is positioned in the axis O direction. A rotor (rotor) (not shown) is disposed on the rotor shaft 21 and is rotatable by a coil (stator) (not shown).
An air cylinder 30 is disposed above the spindle motor 20. The operation direction of the piston rod 31 is coaxial with the axis O. As will be described later, the tip of the piston rod 31 of the air cylinder 30 in the standby position faces the rear end 22b of the collet chuck 22 with a gap therebetween.
One end of a connecting rod 35 is fixed to the upper portion of the air cylinder 30 with a bolt 36. The other end of the connecting rod 35 is connected to the output shaft end of the linear motor 40. The linear motor 40 moves the connecting rod 35 in the Z direction. The linear motor 40 is fixed to the saddle 8.
Since it is the above structure, the spindle motor 20, ie, the drill 12, can be moved in the Z direction by operating the linear motor 40.

Next, a procedure for holding the drill 12 will be described.
FIG. 10 is a cross-sectional view of the tip portion of the spindle motor 20.
A collet chuck 22 and a spring 23 that urges the collet chuck 22 upward in the drawing are disposed at the tip of the rotor shaft 21. A plurality of slits (not shown) are formed on the drill 12 side of the collet chuck 22 in the direction of the rotation axis O, and the diameter can be reduced in the radial direction.
The drill 12 is held by a radial force generated when the tapered surface 22 a formed on the outer periphery of the collet chuck 22 by the spring 23 is urged by the tapered surface 21 a formed on the inner surface of the rotor shaft 21. ing.

Next, a procedure for attaching and detaching the drill 12 will be described.
When exchanging the drill 12, the cylinder 30 is operated. Then, the piston rod 31 descends, and the collet chuck 22 is moved downward in the figure against the spring 23. The collet chuck 22 opens when the tapered surface 22a of the collet chuck 22 is separated from the tapered surface 21a of the rotor shaft 21, and the holding force of the drill 12 on the collet chuck 22 is lost. Therefore, the drill 12 can be removed from the collet chuck 22. Then, after inserting a new drill 12 into the collet chuck 22 in this state, when the piston rod 31 is lifted, the collet chuck 22 is lifted by the spring 23 and the collet chuck 22 is closed. Can be retained. The shank diameter of the drill 12 used in the printed circuit board drilling machine is the same diameter regardless of the nominal diameter of the drill.

By the way, due to the processing, the temperature of each part of the printed circuit board drilling machine rises, and the axis O of the drill 12 deviates from the design value, so that the processing accuracy decreases.
Therefore, prior to making a hole in a work placed on a table movable in the X direction, a plurality of pieces placed on a cross slide arranged above the table and movable in the Y direction perpendicular to the X direction. Deviations in the X and Y directions with respect to the design axis of the spindle of the plurality of tool axes supported at the respective tips of the spindle are detected in each direction, and an average value of the detected deviations in each direction is calculated. There is a printed circuit board drilling machine in which the coordinates of the axes of a plurality of spindles 12 are corrected by an average value in each direction with respect to the center coordinates of the hole to be machined to make holes in the workpiece (patent) Reference 2).

Japanese Patent Laid-Open No. 11-347865 Japanese Patent Laid-Open No. 2007-988

  According to the technique of Patent Document 2, when holes are drilled in the same number of printed circuit boards as a plurality of drills, the positional deviation of holes formed in the printed circuit board can be reduced. However, since the size of the positional deviation itself could not be reduced, the machining accuracy could not be improved.

  An object of the present invention is to provide a drilling machine that can always position the axis O of a drill at a preset position and improve machining accuracy.

In order to solve the above problems, the first means of the present invention is to move in the Y direction with respect to a bed, a table supported to be movable in the X direction with respect to the bed, and a column fixed to the bed. A cross slide supported freely, a saddle supported movably in the Z direction on the cross slide, a collet chuck for holding a tool, a spindle motor for rotating the tool, and the spindle motor A housing that is movably supported in the axial direction of the rotation of the tool and fixed to the saddle, a moving means for moving the spindle motor in the axial direction of the rotation of the tool, and an opening / closing means for opening and closing the collet chuck In a drilling machine that moves the spindle motor relative to the housing, instead of the housing, A sleeve for supporting the spindle motor movably in the axial direction of the tool rotation, a sleeve holder having a space in which the sleeve can be moved in two directions perpendicular to the axial direction of the tool rotation, and the sleeve Fixing means for fixing the sleeve holder in the three axial directions of XYZ , and providing a reference pin on the table, positioning the spindle motor on the reference pin, and releasing the fixing means, The collet chuck is opened and the spindle motor is lowered so that the axial direction of the rotation of the tool is aligned with the axis of the reference pin, and then fixed by the fixing means .

  In this case, the spindle motor is supported so as to be movable in two directions perpendicular to the axial direction of the rotation of the tool between the spindle motor and a moving means for moving the spindle motor in the axial direction of the rotation of the tool. It is more effective to provide a joint and fixing means for fixing the spindle motor to the joint in the three-axis directions of XYZ.

Since the axis O can always be positioned at a preset position, the machining accuracy is improved.
In addition, since it is not necessary to detect in advance a deviation of the drill axis O from a preset position, the axis O can be positioned efficiently.

It is a front partial sectional view of a drill drive part in a printed circuit board drilling machine concerning the present invention. It is a figure which shows the moving range of the main axis | shaft in the printed circuit board drilling machine which concerns on this invention. It is a top view of the table in the printed circuit board drilling machine which concerns on this invention. It is a flowchart explaining the positioning procedure of the main spindle in this invention. It is a figure explaining the specific operation | movement in procedure S150 of FIG. It is a figure explaining the specific operation | movement in procedure S160 of FIG. It is a figure which shows the 2nd Example of this invention. It is explanatory drawing of a prior art. It is explanatory drawing of a prior art. 2 is a cross-sectional view of a tip portion of a spindle motor 20. FIG.

  The present invention will be described below with reference to the drawings.

FIG. 1 is a partial front sectional view of a drill driving unit in a printed circuit board drilling machine according to the present invention, and corresponds to FIG. 9 in the prior art. In addition, the same thing as FIG. 8, FIG. 9 or the thing of the same function attaches | subjects the same code | symbol, and abbreviate | omits the overlapping description. In this embodiment, a pair of drill driving units having the same configuration is provided.
The sleeve 50 having a cylindrical shape and a flange portion 50a at one end fixes the cylindrical spindle motor 20 in the X and Y directions by the bearing 24 and supports the spindle motor 20 so as to be movable in the axis O direction. doing. The lower surface of the flange portion 50 a is in contact with the upper surface of the sleeve holder 51. Two through holes 50c are formed in the flange portion 50a. The lower surface of the flange portion 50a and the upper surface of the sleeve holder 51 are finished to a smooth surface.
A through hole 51 a (space) is formed in the center portion of the sleeve holder 51 in the direction of the axis O. When the diameter of the shank of the drill is d, the diameter of the through hole 51a is D1, and the outer diameter of the cylindrical portion 50b of the sleeve 50 is D2, the diameter D1 is formed such that D1 ≦ D2 + d.
Cylinders 52 are arranged on both sides of the sleeve holder 51 in the Y direction. The inter-axis distance of the piston rod 52a of the cylinder 52 is equal to the inter-axis distance of the through hole 50c.
The diameter of the through hole 50c is larger than the diameter of the piston rod 52a by (D2 + d−D1) or more. A square presser plate 53 is fixed to the tip of the piston rod 52a. The short side of the pressing plate 53 is larger than the diameter of the through hole 50c.
Except for the case where it is determined in advance, the cylinder 52 urges the sleeve 50 downward in the figure and fixes the sleeve 50 to the sleeve holder 51. Hereinafter, the urging of the sleeve 50 by the cylinder 52 downward in the figure is referred to as “fixing the sleeve 50”. The case where the cylinder 52 stops urging the sleeve 50 downward in the drawing is referred to as “opening the sleeve 50”.

A cavity 40b having a circular cross section is formed at the end of the output shaft 40a of the linear motor 40. At the other end of the connecting rod 35, a flange 35f having a circular cross section is formed. The gap g (difference between the height of the cavity 40b in the Z direction and the thickness of the flange 35f) is g = 0.1 to 0.5 mm. The diameter of the cavity 40b is larger than the diameter of the flange 35f by (D2 + d−D1) or more. A joint is formed by the cavity 40b of the output shaft 40a and the flange 35f. The lower surface of the flange 35f and the bottom surface of the cavity 40b (surface on which the lower surface of the flange 35f abuts) are finished to be smooth surfaces.
Two cylinders 54 are arranged at the end of the output shaft 40a. Except for a predetermined time, the cylinder 54 urges the flange 35f upward in the figure and fixes the flange 35f to the output shaft 40a. Hereinafter, urging the flange 54f upward in the figure by the cylinder 54 is referred to as “fixing the connecting rod 35”. The case where the cylinder 54 stops urging the flange 35f upward in the drawing is referred to as “opening the connecting rod 35”.

  Positioning reference pins 60 are arranged in the tool supply area 2 b of the table 2. The diameter of the positioning reference pin 60 is the same as the shank diameter of the drill 12, and the tip is formed in a spherical surface having a radius d / 2. Moreover, the length of the linear part of the positioning reference pin 60 is 15-20 mm. On a circle having a diameter Ds centered on the axis P of the positioning reference pin 60, four holes 61 for distance sensors (here, air sensors) (not shown) are arranged at intervals of 90 degrees in the circumferential direction. . The diameter Ds of the circle in which the hole 61 is disposed is Ds <dk−ds, where dk is the outer diameter of the collet chuck 22 and ds is the diameter of the hole 61. The position of the positioning reference pin 60 in the Y direction will be described later.

FIG. 2 is a view showing the movement range of the spindle S, and FIG. 3 is a plan view of the table 2. In the following description, when the left spindle S is the spindle S1, the right spindle S is the spindle S2, and components such as the cylinder 54 need to be distinguished for each spindle S, the suffix i (where i is (For example, the cylinder 541 is the cylinder 54 for the main shaft S1, and the cylinder 542 is the cylinder 54 for the main shaft S2).
Assuming that the center of the table 2 in the Y direction is Y0, the axis O1 of the drill driving unit S1 moves between the Y coordinate -Y1 and the + Y coordinate y1, as shown in FIG. Further, the axis O2 of the drill driving unit S2 moves from the Y coordinate -y1 to the Y coordinate + Y1. Here, y1 is about 10 to 20 mm.

  As shown in FIG. 3, the tool supply region 2 b includes a drill holder 70 that holds a replacement drill 12, a drill holder 71 that receives the drill 12 held on the main shaft S, and a drill that holds a number of drills. A holder 73 is provided for each of the S2 spindles S1 and S2. The positioning reference pin 60 is positioned at the same position as the drill holders 70 and 71 with the Y coordinate Y0 (that is, the center of the table 2) and the X coordinate.

Next, the procedure for positioning the spindle S will be described.
FIG. 4 is a flowchart for explaining the positioning procedure of the spindle S. The spindle Si is positioned at a predetermined height (standby position) where the tip of the collet chuck 22 i is higher than the positioning reference pin 60 from the table 2.
When positioning of the spindle S is instructed, i = 1 is set (procedure S100), and the axis Oi of the spindle Si (here, the spindle S1) is positioned on the axis P of the reference pin 60 (procedure S110). Next, after setting the number of trials n to n = 1 (procedure S120), the sleeve 50i and the connecting rod 35i are opened (procedures S130 and S140). Next, the collet chuck 22i is opened (step S140), the linear motor 40 is operated, and the tip of the collet chuck 22i is lowered from the surface of the table 2 to a height of (0.5 + g) mm (step S150). When the connecting rod 35i is opened, the tip of the collet chuck 22i drops by g due to gravity, so that the tip of the collet chuck 22i is 0.5 mm above the surface of the table 2 when step S150 is completed. Next, it is checked whether or not all four distance sensors are on (step S160). If all four distance sensors are on, the process of step S170 is performed, and otherwise, step S300 is performed. Perform the process. In step S170, the collet chuck 22i is closed, and then the sleeve 50i and the connecting rod 35i are fixed (steps S180 and S190). Next, the collet chuck 22i is opened (procedure S200), and the tip of the collet chuck 22i is raised to the standby position (procedure S210). Next, it is confirmed whether i = 2 (step S220). If i is 2, the collet chuck 22i is closed (step S230), and the process is terminated. If i is not 2 in step S220, i = i + 1 is set (step S240), and the process of step S110 is performed.

In step S300, it is confirmed whether or not the number of trials n is greater than 3. If n is less than 3, the process of step S310 is performed. If n is greater than 3, an alarm is displayed and the apparatus is stopped. In step S310, the number of trials n is set to n = n + 1, and the sleeve 50i and the connecting rod 35i are fixed (steps S320 and S330). Next, after raising the tip of the collet chuck 22i to the standby position (step S340), the processing of step S130 is performed.
Note that the processing after step S240 is the operation of the spindle S2.

Next, a specific operation in the above procedure will be described.
FIG. 5 is a diagram for explaining a specific operation in step S150.
When the axis Oi of the collet chuck 22 i is deviated from the axis P of the reference pin 60, the collet chuck 22 i comes into contact with the spherical surface portion of the positioning reference pin 60. Assuming that the pressing force of the linear motor 40 against the positioning reference pin 60 is F and the opening angle of the collet chuck 22i is 2θ, a vertical effect of N = Fsinθ acts on the portion of the collet chuck 22i that is in contact with the spherical surface portion. Since a horizontal force of = N cos θ = F sin θ cos θ is applied, the collet chuck 22i, that is, the sleeve 50i moves horizontally toward the axis P. Then, by the procedure S170, the axis Oi and the axis P become coaxial. Therefore, when the procedure 230 is finished, the axis O1 of the main axis S1 and the axis O2 of the main axis S2 have the same X coordinate and are positioned at a distance Y1 in the Y direction.

FIG. 6 is a diagram for explaining a specific operation in step S160.
Normally, the sleeve 50i moves horizontally toward the axis P by the step S150, but the axis Oi may be inclined with respect to the axis P for some reason as shown in FIG. In such a case, the distance sensor on the side away from the surface of the table 2 of the collet chuck 22i is turned off, so that the case where the axis Oi is inclined can be prevented.
In this embodiment, even if the axis Oi is slanted for some reason, it is possible to prevent the apparatus from stopping because the retry is performed up to three times. Normally, the axis Oi can be matched with the axis P by the second step S150.

FIG. 7 is a diagram showing a second embodiment of the present invention. Components having the same or the same functions as those in FIG.
In this embodiment, the cavity 40b is not formed at the end of the output shaft 40a of the linear motor 40, and the connecting rod 35 is fixed to the output shaft 40a.
When the deviation of the axis Oi from the axis P is small (50 μm or less), the axis Oi can be made to coincide with the axis P by bending the connecting bar 35 using the elasticity of the connecting bar 35.
Since the positioning procedure of the spindle Si can be easily understood from the positioning procedure of the first embodiment, the description thereof is omitted.

  As described above, according to the present invention, the main shaft S1 and the main shaft S2 can be accurately positioned at the designed positions, so that highly accurate machining can be performed. In addition, when processing a printed board for each of the main spindle S1 and the main spindle S2, as well as when processing a single printed board using both the main spindle S1 and the main spindle S2, one main spindle in the entire processing area of the printed board. It is possible to obtain the same processing accuracy as when processing with.

  Even when there is only one spindle, it is not necessary to measure the displacement of the spindle in advance by applying the present invention, so that the machining efficiency can be improved.

  The range in which the sleeve 50 can move relative to the sleeve holder 51 is less than ± d / 2 (for example, when the drill shank diameter is 3.175 mm, the maximum is about ± 1.5 mm). In this case, the deviation of the axis O from the design value at the time of manufacture is ± 10 μm or less, and the deformation due to heat is ± 100 μm at the maximum. There is no.

2 Table 12 Drill 20 Spindle motor 22 Collet chuck 30 Cylinder 50 Sleeve 51 Sleeve holder 51a Through hole 52 Cylinder 60 Positioning reference pin O Axis

Claims (2)

Bed and
A table supported to be movable in the X direction with respect to the bed;
A cross slide supported so as to be movable in the Y direction with respect to the column fixed to the bed;
A saddle supported by the cross slide so as to be movable in the Z direction;
A spindle motor having a collet chuck for holding a tool, and rotating the tool;
A housing that supports the spindle motor movably in the axial direction of rotation of the tool and is fixed to the saddle ;
Moving means for moving the spindle motor in the axial direction of rotation of the tool;
Opening and closing means for opening and closing the collet chuck,
In the drilling machine that moves the spindle motor relative to the housing,
Instead of the housing,
A sleeve that movably supports the spindle motor in the axial direction of rotation of the tool;
A sleeve holder having a space in which the sleeve can move in two directions perpendicular to the axial direction of rotation of the tool;
Fixing means for fixing the sleeve to the sleeve holder in three axial directions of XYZ ;
And a reference pin is provided on the table,
Positioning the spindle motor on the reference pin;
Opening the fixing means;
Opening the collet chuck and lowering the spindle motor to adjust the axial direction of rotation of the tool to the axis of the reference pin, and then fixing with the fixing means ,
Drilling machine characterized by that. A joint for movably supporting the spindle motor in two directions perpendicular to the axial direction of rotation of the tool, between the spindle motor and a moving means for moving the spindle motor in the axial direction of rotation of the tool; Fixing means for fixing the spindle motor to the joint in three axial directions of XYZ;
The drilling machine according to claim 1, wherein:

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