JPH091499A - Boring device for printed wiring board - Google Patents

Abstract

PURPOSE: To previously find a defect in a collet chuck or deterioration in cutting efficiency of a drill so as to prevent generation of a fault of boring quality due to these defects in a printed wiring board. CONSTITUTION: A temperature sensor 1 is arranged in a clearance part 5 on the back face side of a collet chuck 11 so as to always monitor a heat ray temperature radiated from the collet chuck 11 and a drill 13, and a defect in the collet chuck 11 and the drill 13 is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punching device for a printed wiring board, which has a large number of through holes scattered on the printed wiring board.

[0002]

2. Description of the Related Art Conventionally, a printed wiring board has a large number of through holes for forming contacts. Since this through hole has a small diameter and the number of scattered spots and positions vary depending on the product type, it has versatility and high positioning accuracy.
A C-controlled drilling device was used. Also, this NC
In the controlled drilling device, the number of rotations of the drill, the relative position of the drill and the printed wiring board, and the like were set in advance in a program, and the drilling was performed automatically by this program.

FIG. 2 is a sectional view of a drill head showing an example of a conventional drilling device for printed wiring boards. As shown in FIG. 2, the drill is attached to the drill head of the drilling device by tightening with the claws of the collet chuck 11 in the rotor 10 rotating in the spindle 9. That is, the collet chuck 11 is pulled into the rotor 10 by pulling the draw bar 8 upward, and the outer tapered portion of the collet chuck 11 is pushed by the inner tapered portion of the rotor 10 to form a plurality of slits. Claw 11a closed and grabbed and held drill 13.

Then, the spindle 9 to which the drill 13 is attached is lowered, the printed wiring board is pressed by the pressure foot 12 so that the drill 13 and the printed wiring board are vertical, and a hole is formed in the printed wiring board by the drill 13. The spindle 9 is raised and the printed wiring board and the spindle 9 are moved relative to each other, the positions of the drill 13 and the holes to be drilled are determined and processed, and a large number of through holes are drilled in the printed wiring board.

[0005]

SUMMARY OF THE INVENTION In the above-mentioned conventional punching device, a load in the opposite direction to the rotation is applied during the processing of some printed wiring boards due to wear of the claws of the collet chuck or deterioration of the sharpness of the cutting edge. It often happens that the clamping force of the pawl is exceeded, slipping between the pawl and the drill and eventually the drill idling in the collet chuck.

The idling of the drill in the collet chuck weakens the transmission of the rotational force applied to the drill and causes a vertical pressing force to be applied to the drill due to the lowering of the spindle despite the insufficient cutting force. This not only causes serious defects in the quality of the drilling, such as bending of the hole and roughening of the inner wall, but also causes the problem of breaking the drill.

Further, although an NC control device having a function of routine control such as rotation and positioning of a drill or ascending / descending of a spindle is provided, it does not have a function of monitoring such a phenomenon leading to an accident. Unexpectedly, processing defects of the printed wiring board will occur.
In order to prevent such accidents in advance, at present, there is no choice but to regularly stop the device and investigate the condition of the claws of the collet chuck and the condition of the blade surface of the drill. Was there.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a punching device for a printed wiring board, which can prevent the deterioration of the sharpness of the drill and the quality accident of the printed wiring board due to the idling of the drill in the collet chuck. .

[0009]

The features of the present invention are: a collet chuck mounted on a rotor in a spindle for inserting a drill; and a collet chuck arranged in a space on the back side of the collet chuck for inserting the drill. Printing provided with a temperature sensor for detecting the temperature of heat rays emitted from the chuck and the drill, and means for stopping the rotation of the drill and issuing an alarm when the temperature by the temperature sensor exceeds a predetermined value and shows an abnormal value This is a hole punching device for wiring boards.

[0010]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a drill head showing an embodiment of a drilling device for a printed wiring board according to the present invention. The present invention is directed to the collet chuck 1 by means of frictional heat caused by idling of the drill 13 in the collet chuck 11 and heat rays emitted by a rise in temperature of the drill due to deterioration of cutting force of the drill.
This is made based on the knowledge that the temperature of the closed back side space 5 of No. 1 abnormally rises.

That is, as shown in FIG. 1, the punching device for a printed wiring board according to the present invention is arranged in the space 5 of the collet chuck 11 for tightening and mounting the drill 13 by the operation of the draw bar 8 in the spindle 9. When the temperature measurement value of the measuring unit 2 measured by the temperature sensor 1 exceeds a predetermined value and indicates an abnormal temperature, the rotation of the drill 13 is stopped by the command of the control unit 3 and the alarm unit 6 is also provided. Is to raise an alarm.

Although not shown in the drawing, the table is mounted on a printed wiring board and is moved in the X direction, and a gate type frame having a drive mechanism for moving the spindle in the Y direction and straddling the table and the control section 3 are incorporated. NC controller is
It is equipped as in the past.

As the temperature sensor 1, for example, a thermocouple such as chromel or alumel is used, and it is suspended from above by a wiring cable 4. Further, even if the rotor 10 rotates, the wiring cable 4 and the temperature sensor 1 do not come into contact with the inner wall of the draw bar 8. In this case, drawbar 8
When the hole is sufficiently large and if it is small, the wiring cable 4 is put in a metal tube, and a rotary bearing is provided between the metal tube and the spindle 9 so that the rotation of the rotor 10 does not twist the wiring cable 4. To In any case, this means that the temperature sensor 1 and the measuring unit 2 are directly connected to each other in order to increase the S / N ratio.

Next, the operation of this punching device will be described.
Normally, during processing with the drill 13, the temperature of the temperature sensor 1 is higher than room temperature by at most about 10 degrees. Here, assuming that the wear of the claws of the collet chuck 11 and the presence of foreign matter such as dirt and chips between the collet chuck 11 and the drill 13 reduce the drill chuck force of the collet chuck 11 and cause idling, the collet chuck 11 and The frictional heat of the drill 13 increases, and the temperature of the space 5 of the collet chuck 11 rises by about 50 ° C. to 100 ° C. more than usual.

At this time, the temperature is measured by the temperature measuring section 2 by the electromotive force generated in the thermocouple section of the temperature sensor 1, compared with the reference temperature, and it is judged that the level is large, and a signal for activating the power transistor is sent to the control section 3. Transfer to. Control unit 3
Supplies the output of the power transistor to the alarm unit 6 to generate an alarm and stops the rotation of the drill 13. Then, after confirming that the blade surface of the drill 13 is not worn, the collet chuck 11 is replaced.

Even though the collet chuck 11 is replaced, the temperature sensor 1 is exposed to the heat radiated into the space 5.
When the temperature is higher than usual, this temperature is regarded as an abnormal temperature and an alarm is issued to stop the device.
After checking that there is no abnormality, replace the drill 13.

As described above, by providing the temperature detecting mechanism for measuring the heat radiated by the drill and the collet chuck and constantly monitoring the temperature, deterioration of the sharpness of the drill and a defect of the collet chuck can be found in advance and, if necessary, Exchange.

[0019]

As described above, according to the present invention, the temperature sensor for measuring the heat released from the collet chuck or the drill is provided in the space of the collet chuck, and the temperature that rises abnormally is detected. It is possible to detect wear of the drill and defects of the holding force of the collet chuck at an early stage, and to prevent the quality accident of the printed wiring board caused by the defects of the collet chuck in advance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a drill head showing an embodiment of a drilling device for a printed wiring board according to the present invention.

FIG. 2 is a cross-sectional view of a drill head showing an example of a conventional drilling device.

[Explanation of symbols]

 1 Temperature Sensor 2 Measurer 3 Control 4 Wiring Cable 5 Space 6 Alarm 8 Drawbar 9 Spindle 10 Rotor 11 Collet Chuck 11a Claw 12 Pressure Foot 13 Drill

Claims (1)

[Claims] 1. A collet chuck which is attached to a rotor in a spindle and into which a drill is inserted, and a collet chuck which is arranged in a space on the back side of the collet chuck in which the drill is inserted and which is emitted from the collet chuck and the drill. A drilling device for a printed wiring board, comprising: a temperature sensor for detecting a temperature; and a means for stopping the rotation of the drill and issuing an alarm when the temperature by the temperature sensor exceeds a predetermined value and shows an abnormal value. .