JP2002307220A - Method of machining workpiece, and printed circuit board boring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed circuit board boring machine that can improve machining quality and machining efficiency while preventing machining by a defective drill. SOLUTION: A tool diameter detector provided with a sensor 31 is disposed on a table. Prior to machining, the tip side diameter D1 of a cutting edge part 1c of a drill 1, and the base end side diameter D2 spaced by a predetermined distance from the tip, are measured, and machining is performed only when both diameters almost coincide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work processing method for processing a work such as a printed circuit board using a tool such as a drill or an end mill held on a spindle, and a printed circuit board processing machine.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view of a drill cassette 3 used in a printed circuit board drilling machine. A resin-made drill ring 2 is arranged on the shank 1a of the drill 1 so as not to move easily. The drill ring 2 is positioned on the shank 1a such that the distance L1 from the upper surface 2a to the tip 1b of the drill 1 is the same regardless of the diameter of the tool. The drill cassette 3 has a counterbore 3a into which the drill ring 2 fits, and a shank 1a.
A storage hole 3b into which the blade portion 1c is loosely fitted is provided.
The drill 1 is positioned in the horizontal and vertical directions by positioning the drill ring 2 in the storage hole 3a.

When the shank 1a is held while the lower end 22a of the spindle 22 shown by the two-dot chain line is in contact with the upper surface 2a of the drill ring 2, the length from the lower end of the spindle 22 to the tip 1b of the drill 1 is reduced. Since the length of the drill 1 is always the same, it is not necessary to measure the length of the drill 1 when the drill 1 is replaced, so that the processing efficiency can be improved.

[0004] Japanese Patent Application Laid-Open No. 1-306156 discloses a technique of a printed circuit board processing machine provided with a drill detecting device. According to this technique, the tip position of the tool, the diameter and the amount of eccentricity of the tool can be reliably confirmed.

[0005]

However, in the case of using the above-mentioned drill ring 2, the drill ring 2
Is attached to the drill 1 by an automatic machine or manually, but in any case, it may be mistakenly attached to a drill having a short blade portion or a drill having a broken tip (hereinafter, referred to as “defective drill”). Then, when processing is performed with such a defective drill, a hole having a desired depth cannot be processed. In addition, there is a problem that the drill 1 is broken or the work or the spindle 22 is damaged due to the lower portion of the shank portion 1a having no blade being cut into the work.

[0006] On the other hand, in Japanese Unexamined Patent Publication No. Hei 1-306156, as described above, the tip position of the tool, the diameter and the eccentricity of the tool can be surely confirmed, but the depth of the hole to be machined is determined. The relationship between the length of the drill and the length of the cutting edge of the drill is not seen, so that there is a problem that, similarly to the above, machining is performed by mistake with a drill having a short cutting edge.

[0007] The above problems and problems occur not only when a drill is used as a tool but also when, for example, an end mill is used.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a work processing method and a printed circuit board processing machine capable of improving the processing efficiency, preventing the processing by a defective tool and improving the processing quality. It is assumed that.

[0009]

According to a first aspect of the present invention, there is provided a method of processing a workpiece, comprising arranging a positioning ring at a predetermined position from a tip of a tool and determining a processing depth based on the ring. In the method, prior to machining, the length of the blade portion of the tool is measured, and after confirming that the length of the blade portion is longer than a predetermined depth of a hole to be machined, machining is performed. .

According to a second aspect of the present invention, in the method for processing a workpiece according to the first aspect, the tool has a blade portion having a diameter substantially equal at an arbitrary position along an axial direction, and A tool having a large-diameter shank portion, and a diameter of a portion of the tool inserted into the hole at the time of machining a hole of a predetermined depth at an arbitrary position in the axial direction is substantially equal to a diameter of the blade portion. After confirming that they match, processing is performed.

According to a third aspect of the present invention, in the method for processing a workpiece according to the first aspect, the tool has a blade portion having substantially the same diameter at an arbitrary position along the axial direction, and A tool having a large-diameter shank portion, wherein the diameter of two portions of the tool, which are inserted into the hole at the time of machining a hole of a predetermined depth, on the distal end side and the proximal end side, are substantially the same. The processing is performed after confirming the fact.

According to a fourth aspect of the present invention, there is provided a blade having substantially the same diameter at an arbitrary position in the axial direction, and a shank formed on the base end side of the blade and having a diameter larger than that of the blade. In a printed circuit board processing machine that performs processing using a tool, a tool diameter detection device for measuring the diameter of the tool is provided, and prior to processing, the tool diameter detection device uses the first tool on the tip side of the blade portion. Measuring a diameter at a position and a diameter of the tool at a second position proximally spaced a predetermined distance from the first position;
Processing is performed after confirming that the diameters at the second position are substantially the same.

[Operation] The length of the blade portion is measured before machining, and the length of the blade portion is longer than the depth of a hole to be machined. Therefore, the spindle and the work are not damaged, and the processing quality and the processing efficiency can be improved. Moreover, the device configuration is simple.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. It is to be noted that components denoted by the same reference numerals in the drawings have the same configuration or operation, and redundant description thereof will be omitted as appropriate.

FIG. 1 is a perspective view of a printed circuit board drilling machine 4 as an example of a printed circuit board processing machine according to the present invention, and FIG. 2 is a longitudinal sectional view of a tool diameter checking device 8.

In FIG. 1, a table 6 provided on a printed board drilling machine 4 can be positioned on a bed 5 in a X direction (a front-back direction toward the printed board drilling machine 4) by a driving means (not shown). It is. On the table 6, a plurality of (three in the figure) drill cassettes 3, a tool post 7, a tool diameter checking device 8, and a printed circuit board 9 as a workpiece are provided for each spindle 22. Fixed.

The drill cassette 3 holds a large number of drills 1. Further, similarly to the drill cassette 3, the tool post 7 has a counterbore for fitting the drill ring 2 (see FIG. 5) and a housing for storing the shank portion and the blade portion of the drill 1 coaxially with the counterbore. Two drill holding portions 7a and 7b each including a hole are provided, and the drill 1 can be positioned and held.

The housing 21 is driven by driving means (not shown) to move the front surface of the cross rail 20 fixed to the bed 5 in the Y direction transverse to the X direction and in the vertical direction with respect to the Y direction. Positioning is possible in the perpendicular Z direction. The spindle 22 has its outer periphery held by the housing 21 and holds the drill 1 at its lower end. NC controller 23
Is for controlling the operation of each part of the printed board drilling machine 4.

As shown in FIG. 2, the tool diameter checking device 8 includes:
A holder 30 and a distance sensor 31 are provided. The holder 30 is provided with a hole 32 having a circular cross section and an axis C extending in the Z direction from above. The distance sensor 31 is fixed to the holder 30 so as to face the axis C, and outputs the measured value to N
Output to the C controller 23. The distance from the measurement reference position of the distance sensor 31 to the axis C is La.

Next, the operation of the present invention will be described.

FIG. 3 is a flowchart showing a procedure for confirming the drill shape. Note that among the tools (the drills 1 in this case) held in the drill cassette 3 by a tool changing device (not shown) in advance,
Beforehand, one drill holding part 7a of the tool post 7
To be kept.

First, the spindle 22 is connected to the drill holder 7b.
Drill 1 positioned and held in the axis (Z direction) of
Is placed on the drill holder 7b, and then the drill 1 supported by the drill holder 7a is held (S1). Next, the axis of the spindle 22 is made to coincide with the axis C of the tool diameter checking device 8 (S2).

Next, as shown in FIG. 4 (a), the spindle 22 is lowered, and a position J is located from the tip 1b of the drill 1 (first position: a position slightly higher than the outer corner 1d of the drill 1). Is positioned at the measurement position of the sensor 31. Then, in this state, the spindle 22 is rotated at least once at a very small speed, and the minimum distance Lb among the measurement signals output from the distance sensor 31 and the distance La known in advance are calculated by the following equation (1). Then, the diameter D1 of the drill 1 is determined (S3).

D1 = (La−Lb) × 2 (1)

Then, a difference (d-d1) between the nominal diameter d and the diameter D1 of the drill 1 is obtained, and this difference and an allowable value α (where
α is a positive value, for example, 0.1 mm. ) Is compared with (S4). If -α ≦ (d−D1) ≦ α, the processing of S5 is performed. In other cases, that is, (d−D1)
1) If | α |, the process of S8 is performed.

In step S5, as shown in FIG.
The spindle 22 is lowered by a distance M set in advance, and a position on the base end side (second position) in the same manner as described above.
The diameter D2 of the drill 1 at is obtained. Where the distance M
Where K is the depth of the hole to be machined, ΔT is the tolerance of the thickness of the printed circuit board, θ is the apex angle of the drill 1, d is the nominal diameter of the drill, and Q is the margin allowance. expressed.

M = K + ΔT− {J− (d / 2) · tan (π−2−θ / 2)} + Q (2)

The thickness tolerance .DELTA.T and the apex angle .theta. Are input in advance into a machining program. In addition, room Q
Is, for example, 0.5 m when the nominal diameter d is 1 mm or more.
m and 0.2 mm when the nominal diameter d is less than 1 mm.
In addition, when the above-mentioned plate thickness tolerance ΔT and allowance Q are not provided, as shown in FIG.
Is equivalent to the distance from the outer corner 1d of the drill 1 to the portion 1e of the blade 1c, that is, the length of the portion of the blade 1c that substantially contributes to cutting.

Next, the difference between the diameter D1 and the diameter D2 is determined (S6). If (D1−D2) ≧ 0, the process of S7 is performed. In other cases, that is, (D1−D2) <0 In this case, the process of S8 is performed. Generally, in the drill 1, the diameter D of the blade portion 1c is equal to the tip excluding the top, that is, FIG.
The outer peripheral corner 1b in (a) and (b) is the largest,
The diameter becomes smaller toward the base end side (the upper end side in the figure) or is set to be the same. Further, a portion other than the blade portion 1c of the drill 1, for example, a shank portion 1a is a blade portion 1c.
It is formed so that the diameter is larger than that. Therefore, satisfying the above expression, (D1−D2) ≧ 0, means that the portion where D2 is measured is a part of the blade portion 1c. That is, when a hole having a predetermined depth K is formed by the drill 1, there is no possibility that a portion other than the blade portion 1c, for example, the shank portion 1a will bite into the hole being processed.

In step S7, the difference between the diameter D1 and the diameter D2 and an allowable value β (where β is a positive value, for example, 0.0
5 mm. ), And if (D1−D2) ≦ β, the processing is terminated and drilling is executed; otherwise, that is, if D1−D2)> β, the processing of S8 is performed.

In step S8, it is checked whether or not a usable drill 1 having the same diameter is prepared among the drills 1 prepared in the drill cassette 3. If there is a drill 1 having the same diameter, the processing in S1 is performed. On the other hand, in other cases, an alarm is displayed (S9), and the processing is stopped.

In this embodiment, before measuring the diameter D2, the nominal diameter d of the drill 1 is compared with the diameter D1, so that the tip of the drill 1 is bent or
When the axis of the drill 1 is held eccentrically with respect to the axis C of the spindle 22 (the apparent diameter D1 becomes large), machining is not performed, so machining accuracy (dimensional accuracy).
In addition, the shape accuracy of the hole can be improved.

The processing in step S7 is performed to further enhance the processing accuracy and the shape accuracy of the hole, and may be omitted if not particularly necessary.

In the above description, the case where one distance sensor 31 is provided has been described. However, if a plurality of distance sensors 31 are provided and are arranged radially at equal intervals on the same plane, the measurement accuracy of the drill diameter can be further improved. Can be improved.

Further, the present invention is not limited to a printed circuit board drilling machine mainly for processing a printed circuit board by using the drill 1, but also a print machine for processing an outer shape of a printed circuit board and an inner peripheral surface of a drill hole using an end mill. The present invention can also be applied to other devices such as a substrate contour processing machine.

[0036]

As described above, according to the present invention,
After confirming that the length of the blade portion is longer than the depth of the hole to be machined, machining is performed, so that machining quality and machining efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a printed board drilling machine (printed board processing machine) according to the present invention.

FIG. 2 is a longitudinal sectional view of a tool diameter checking device.

FIG. 3 is a flowchart showing a procedure for confirming a drill shape.

FIG. 4 is a diagram illustrating a measurement position of a drill.

FIG. 5 is a sectional view of a drill cassette used in a printed circuit board drilling machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool (drill) 1a Shank part 1b Tip 1c Blade part 1d Outer corner 2 Ring 8 Tool diameter detecting device D1 Diameter at first position D2 Diameter at second position

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Katsuhiro Nagasawa 2100 Kamiimaizumi, Ebina-shi, Kanagawa F-term in Hitachi Via Mechanics Co., Ltd. (Reference) 3C029 AA21 DD04 3C036 AA01 LL08 3C060 AA11 BA05 BD01 BE07 BG13 BH01

Claims (4)

[Claims] 1. A method for machining a workpiece, comprising: arranging a positioning ring at a predetermined position from the tip of a tool and determining a machining depth based on the ring; Measuring the length of the blade portion, and confirming that the length of the blade portion is longer than a predetermined depth of the hole to be processed, and then performing the processing. 2. The tool according to claim 1, wherein the tool has a blade portion having a diameter substantially equal to an arbitrary position along an axial direction, and a shank portion having a larger diameter than the blade portion. When machining a hole having a depth, the machining is performed after confirming that the diameter at an arbitrary position in the axial direction of a portion inserted into the hole substantially matches the diameter of the blade portion. 2. The method for processing a workpiece according to 1. 3. The tool has a blade portion having a diameter substantially equal to an arbitrary position along an axial direction, and a shank portion having a larger diameter than the blade portion. The method according to claim 1, wherein when processing a hole having a depth, the processing is performed after confirming that the diameters at two positions on a distal end side and a base end side of a portion to be inserted into the hole substantially match. Processing method of the described work. 4. Processing is performed using a tool having a blade portion having substantially the same diameter at an arbitrary position in the axial direction and a shank portion formed on the base end side of the blade portion and having a larger diameter than the blade portion. In a printed circuit board processing machine, a tool diameter detecting device for measuring the diameter of the tool is provided, and prior to processing, the diameter at a first position on the tip side of the blade portion by the tool diameter detecting device; Measure the diameter of the tool at a second position separated from the position 1 by a predetermined distance to the base end side, and confirm that the diameters at the first and second positions are substantially the same. A printed circuit board processing machine.