JP2000005910A - Device for removing chip from printed circuit board working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple suction force control structure which does not lift the upper surface of work when lifting a pressure foot. SOLUTION: When machining of one hole is finished, a spindle unit 1 rises with a retaining bush 41 held pressed against work W. When the spindle unit 1 becomes higher than a machining starting height position P1, an air inflow port 28 closed by the outer peripheral surface 1a of its end portion opens. Thereafter, when the retaining bush 41 leaves the upper surface of the work W, outside air flows into a space inside a pressure foot from the air inflow port 28 completely opened and decreases the suction force of a dust collector 50, preventing the upper surface (entry board) of the work W from being sucked up together.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip removing device for a printed circuit board processing machine.
The present invention relates to a technique for separating a pressure foot on which a suction force for removing chips is acting.

[0002]

2. Description of the Related Art In a printed circuit board processing machine, a spindle is surrounded by a pressure foot, a spindle is lowered while a work is held down by the pressure foot, and processing is performed by a tool at a tip, and chips generated during the processing are removed. In addition, a suction force is applied to the inside of the pressure foot by a dust collector to remove by suction. The work to be processed by the printed circuit board processing machine is composed of several printed circuit boards stacked on top of each other with a thin entry board, and the lower side sandwiched with a backup board. When the spindle and the pressure foot are lifted to move to the next processing position and the lower surface of the pressure foot is separated from the upper surface of the work, the suction board of the dust collector sucks up the entry board on the upper surface of the work together. . When the spindle is moved to the next processing position in this suction state, the entry board is scratched,
Next, when the tool is lowered for machining, the tip of the tool is guided according to the scratch, and there is a problem that the accuracy of the machining hole position is reduced.

Japanese Patent Application Laid-Open No. 4-354608 discloses a device for controlling the suction force of such a dust collector. According to this, the L-shaped bracket is attached to the pressure foot such that one end has a predetermined distance from the lower surface of the pressure foot, and the slide is slidable in the axial direction and the horizontal direction between the L-shaped bracket and the lower surface of the pressure foot. A work holding member projecting downward from the L-shaped bracket is provided integrally on the lower surface of the slide plate. When processing is completed and the pressure foot is lifted by a predetermined amount together with the spindle, the work is held on the work by its own weight. A gap is formed between the upper surface of the slide plate having the remaining pressing member and the pressure foot, and the outside air is introduced from the gap to reduce the suction force inside the pressure foot.

[0004]

In the above-mentioned conventional apparatus,
The slide plate is moved up and down below the pressure foot to create a gap between the pressure foot and the slide plate, so the slide plate is required separately from the pressure foot, and the number of parts increases. A structure for supporting up and down movement is required, and the structure is complicated. The object of the present invention is to
An object of the present invention is to reduce the suction force acting on the inside of the pressure foot when moving to the next hole processing with a simple configuration, thereby alleviating the suction state on the upper surface of the work.

[0005]

A pressure foot is fitted to the end of the spindle unit so as to be movable in the axial direction, and the spindle unit is further lowered with respect to the pressure foot in a state where the pressure foot presses the printed circuit board and stops descending. Then, in a chip removing device of a printed circuit board processing machine for processing a printed circuit board by a tool at a spindle tip and sucking and removing chips generated at the time from the inside of the pressure foot, the tip of the spindle unit is fitted by raising and lowering the spindle unit. An air inlet, which is opened and closed by the mounting part, is provided on the pressure foot, the air inlet is closed during processing by a tool, and the air inlet is open when the pressure foot is separated from the work. It is characterized by the following (claim 1). Further, in the present application, a pressure foot is fitted to the tip of the spindle unit so as to be movable in the axial direction, and the spindle unit is further lowered with respect to the pressure foot while the pressure foot presses the printed circuit board and stops descending. In a chip removing device of a printed circuit board processing machine for processing a printed circuit board by using the above-mentioned tool and removing chips generated at that time from the inside of the pressure foot, when a spindle unit is in a processing height range, an outer peripheral surface of a tip portion thereof. An air inlet, which is closed by the pressure foot and is opened when it is located at a position higher than the processing height range, is provided on the side wall of the pressure foot (claim 2). Instead of the air inlet, an air inflow groove of a predetermined length may be formed below the upper surface of the pressure foot on the inner surface of the side wall of the pressure foot (claim 3), or a predetermined length from the upper surface of the pressure foot. May be formed in the side wall of the pressure foot (claim 4).

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A spindle unit 1 is a lifting base.
It is sandwiched between upper and lower walls 3 and 4 of the blade 2 and the fastener 5 and is integrally fixed to the elevating base 2. The lifting base 2 moves up and down, left and right by a vertical feed screw mechanism and a horizontal feed screw mechanism (not shown). A spindle 6 is rotatably supported on the spindle unit 1. A spindle unit 1 is provided between the walls 3 and 4.
A pair of guide rods 7, 7 are movably inserted in both sides of the upper surface 3, and an upper end of the guide rod 7 protrudes above a guide bush 8 fixed to the upper wall 3, and a hook 9 Is provided. The lower end of the guide rod 7 protrudes below the lower wall 4, and is connected to the right and left mounting portions 20 a of the pressure foot 20. An engaging portion 10 is integrally provided at an intermediate portion between the guide rods 7, 7, and a compression spring 11 is interposed between the engaging portion 10 and the upper wall 3. The hook portion 9 is urged by the spring force of the spring 11 in the direction in which the hook portion 9 comes into contact with the upper surface of the guide bush 8, and in the contact state, the downward movement of the guide rod 7 with respect to the elevating base 2 is regulated.

The pressure foot 20 has a spindle accommodating chamber 21 which is fitted movably in the axial direction (vertical direction) with respect to an outer peripheral surface (tip fitting portion) 1a of the distal end portion of the spindle unit 1; And a suction chamber 22 provided adjacent to the suction chamber. The spindle accommodating chamber 21 and the suction chamber 22 communicate with each other through a communication hole 25 provided on the lower wall 24 of the pressure foot 20 on the cylindrical side wall 23 forming the spindle accommodating chamber 21. On the upper wall 26 of the suction chamber 22,
A duct connection hole 30 that opens downward into the suction chamber 22 is formed in parallel with the spindle axis. A suction pipe 32 constituting a part of the duct 31 is welded to the duct connection hole 30 with its axial direction parallel to the spindle axis. A suction pipe 33 extending upward along the spindle axis is connected to the upper end of the suction pipe 32 to form a duct 31 together with the suction pipe 32. The position of the duct connection hole 30 is set so that the duct 31 can extend straight upward along the spindle axis. The suction pipe 32 projects a predetermined amount toward the inside of the suction chamber 22. The amount of protrusion is such that the chips to be sucked are formed at the inlet edge 32a of the suction tube 32.
This part is worn by colliding with, so that the wear allowance L is considered so that the wear period is sufficiently long (about 3 to 5 years). Here, it protrudes to a height position reaching the upper edge of the communication hole 25. A dust collector 50 is connected to the suction pipe 33, and swarf generated in the pressure foot 20 at the time of processing is removed by suction of air from the dust collector 50. A holding bush 41 is fixed to the lower wall 24 of the pressure foot 20 by a backup board (lower side) and an entry board (upper side) to contact the upper surface of the work W sandwiching the upper and lower sides of the stacked printed circuit boards. On the contact surface (lower surface) with the upper surface of the work W,
A plurality of grooves 42 for introducing air radially from the center are formed so as to reach the tool insertion hole 43 at the center of the bush 41.

The cylindrical side wall 23 forming the spindle accommodating chamber 21 is provided with a plurality of air inlets 28 (three in this case). The air inlet 28 is formed as a slit having a relatively small width in the vertical direction penetrating the side wall 23 so as to communicate the space inside the spindle housing chamber 21 and the space outside the pressure foot 20. In this embodiment formed as a slit as described above, since the cylindrical guide surface slidably guided by the spindle unit tip 1a is formed above and below the slit, the vertical sliding guide of the pressure foot 20 is good. Done in The air inlet 28 is slightly opened below the height position (opening height position P0) of the spindle unit tip surface 1b in a state where the hook portion 9 is in contact with the upper surface of the guide bush 8 (FIGS. 1 and 3). , The spindle unit 1 moves relative to the pressure foot 2 while the pressure foot 20 holds down the workpiece W.
0, the tool T at the leading end is lowered from the open height position P0 (FIG. 3) to start cutting into the upper surface of the work W from the processing start height position P1 to the most cut position P2 as shown in FIG. In the intermediate processing height range ST, it is formed so as to be directly closed by the outer peripheral surface 1a of the tip end of the spindle unit 1.

The dust collector 50 constantly generates a suction force inside the pressure foot 20 irrespective of whether it is being processed or not. When the spindle unit 1 is positioned coaxially with a predetermined drilling position, the pressure foot 20 and the spindle unit 1 are moved in a state where the hook 9 of the guide rod 7 is in contact with the guide bush 8 by the spring force of the spring 11. Are lowered while the relative vertical direction of FIG. 1 is maintained by the lowering of the lifting base 2, and the pressure foot 20 abuts on the upper surface of the work W on the table 40 via the bush 41 (FIG. 3). . When the elevating base 2 is further lowered, the spindle unit 1 is relatively lowered with respect to the pressure foot 20 while bending the spring 11 of the guide rod 7, and the machining start height position at which the tool T starts to cut into the upper surface of the work W At P1, the outer peripheral surface 1a of the tip end of the spindle head 1 blocks the air inlet 28. Further, the spindle head 1 descends, and the tool T pierces the work W through the tool insertion hole 43 (FIG. 4).

During the machining by the tool T, the work W is pressed by the pressing bush 41 near the edge of the machining hole.
The lifting of the work caused by the lead of the tool T (drill) during machining can be suppressed, and inconvenience such as occurrence of return can be avoided. The air inlet 28 is closed by the outer peripheral surface 1a of the distal end portion of the spindle head 1, and no outside air enters from the air inlet 28, so that the suction airflow from the dust collector 50 reduces the pressure. The inner space of the pressure foot 20 does not act on the inner space of the pressure foot 20 through the tool insertion hole 43 from the air inflow passage formed between the groove 42 of the bush 41 and the upper surface of the work W. Air flows into the air. Chips generated in the vicinity of the tool T by the drilling of the tool T are sucked up by the suction airflow, and the communication hole 2 is removed from the inside of the spindle accommodating chamber 21.
After passing through 5, it enters the adjacent suction chamber 22, is sucked through the suction port 32 b of the suction pipe 32, passes through the suction pipe 33, and is conveyed to the dust collector 50.

When one boring operation is completed, the lifting head 2 rises, whereby the spindle unit 1 first rises while the pressing bush 41 below the pressure foot 20 is pressed against the work W by the spring force of the spring 11. Then, when the tool T exceeds the machining start height position P1 at which the tool T separates from the work, the air inlet 28 opens, and outside air flows into the pressure foot 20 internal space from the air inlet 28. Furthermore, when the spindle unit 1 is raised with respect to the pressure foot 20 by the lifting of the lifting head 2, and the guide bush 8 reaches the height position P0 where the hook 9 is hooked, the air inlet 28 is completely opened (FIG. 3). ). Further, the lifting head 2
Rises, spindle unit 1 and pressure foot 2
0 is slightly (about 1 mm) away from the upper surface of the workpiece W while maintaining the positional relationship shown in FIG. 3, and moves to the next processing hole position while maintaining its height state (FIG. 1). When the presser bush 41 below the pressure foot 20 separates from the upper surface of the work, the outside air flows from the air inlet 28 into the pressure foot 2.
Since the suction force by the dust collector 50 is reduced by flowing into the internal space of No. 0 and the suction force acting on the upper surface of the work W is reduced, it is possible to prevent the upper surface of the work W (entry board) from being sucked together. As in the related art, it is possible to avoid a problem in which the entry board is rubbed and scratched by moving while sucking the upper surface of the work W, and the tool tip is aligned with the scratch to lower the processing position accuracy.

FIG. 5 shows another example. here,
Instead of the air inlet 28, an air inflow groove 28A is formed at a predetermined groove depth in the radial direction from the inner surface of the side wall 23 of the pressure foot 20 and a predetermined length downward from the upper surface of the pressure foot 20. I have. This air inflow groove 2
8A, the inner space of the pressure foot 20 communicates with the outside air when the spindle unit 1 becomes higher than the machining start height position P1, similarly to the above-described embodiment.
Is set to be lower than the machining start height position P1 so as to cut off the communication.

Further, in FIG. 6, an air inflow cutout 28B having a predetermined length from the upper surface of the pressure foot 20 is formed in the side wall 23 of the pressure foot 20 instead of the air inflow port 28. This air inflow notch 2
8B, similarly to the above embodiment, when the spindle unit 1 is higher than the processing start height position P1, the internal space of the pressure foot 20 communicates with the outside air, and when the spindle unit 1 is at a position lower than the processing start height position P1. The length below is set so as to block the communication.

[0014]

As described above, according to the present invention, the suction force of the dust collector is reduced because the air inlet (the air inlet groove, the air inlet notch) of the pressure foot is closed during the processing by the tool. It works on the inner space of the pressure foot without any trouble and can smoothly collect the chips during processing. Further, when the pressure foot is separated from the work, the air inlet (air inflow groove, air inflow notch) is opened, so that the external pressure flowing through the air inflow port (air inflow groove, air inflow notch) causes the pressure foot to open. The suction force of the dust collector acting on the inside is reduced, and as a result, the suction force sucking up the top surface of the work is reduced, and when moving to the next processing position, the top surface of the work is moved while sucking up and the surface of the work is damaged. It is possible to prevent such a problem that the tool is imitated by the flaw, thereby lowering the processing position accuracy. In addition, the present application directly opens and closes the air inlets (air inlet grooves, air inlet notches) provided in the pressure foot on the outer peripheral surface of the distal end portion of the spindle unit.
It is only necessary to form an air inlet (air inlet groove, air inlet notch) at a predetermined height position of the pressure foot, and an extremely simple configuration can be achieved without increasing the number of parts.

[Brief description of the drawings]

FIG. 1 is a front view of a printed board processing machine.

FIG. 2 is a II view of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;
This shows a state in which the lower surface of the bush is in contact with the upper surface of the work.

FIG. 4 is a view showing a state during processing in FIG. 3;

5A and 5B are diagrams showing another embodiment, in which FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along line Vb-Vb of FIG.

6A and 6B are diagrams showing still another embodiment, in which FIG. 6A is a plan view, and FIG. 6B is a sectional view taken along the line VIb-VIb of FIG.

[Explanation of symbols]

 Reference Signs List 1 spindle unit 1a outer peripheral surface of spindle unit tip end part 6 spindle 20 pressure foot 21 spindle accommodation room 23 side wall 28 air inlet 50 dust collector T tool ST machining height range

Claims (4)

[Claims] 1. A spindle unit is further lowered with respect to the pressure foot while a pressure foot is fitted to the tip of the spindle unit so as to be movable in the axial direction, and the pressure foot presses a printed circuit board and stops descending. In the chip removing device of the printed circuit board processing machine, which processes the printed circuit board with the tool at the tip and removes the chips generated at that time from the inside of the pressure foot, it is opened and closed by the tip fitting part of the spindle unit by raising and lowering the spindle unit The air inlet is provided in the pressure foot, the air inlet is closed during machining by a tool, and the air inlet is open when the pressure foot is separated from the work. Chip removal equipment for printed circuit board processing machines. 2. A spindle unit is further movably fitted to the tip of the spindle unit so as to be movable in the axial direction. The spindle unit is further lowered with respect to the pressure foot in a state where the pressure foot presses the printed circuit board and stops descending. In a chip removal device of a printed circuit board machine that processes a printed circuit board with a tool at the tip and removes chips generated at that time from the inside of the pressure foot, when the spindle unit is within the processing height range, the outer periphery of the tip A chip removing device for a printed circuit board processing machine, characterized in that an air inlet which is closed by a surface and is opened when it is located at a position higher than a processing height range is provided on a side wall of a pressure foot. 3. A chip removing device for a printed circuit board processing machine according to claim 1, wherein an air inflow groove having a predetermined length is formed below the upper surface of the pressure foot on the inner surface of the side wall of the pressure foot instead of the air inflow port. apparatus. 4. The chip removing device for a printed circuit board processing machine according to claim 1, wherein an air inflow notch having a predetermined length from an upper surface of the pressure foot is formed in a side wall of the pressure foot instead of the air inflow port.