JP4017895B2 - Printed circuit board processing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printed circuit board processing machine that processes a workpiece placed on a table while pressing it with a pressure foot.
[0002]
[Prior art]
FIG. 4 is a front view of a main shaft portion in a conventional printed circuit board processing machine.
[0003]
The main shaft 1 is fixed to a housing 3 that is movable in the height direction (Z-axis direction), and a drill (tool) 13 is rotatably held at the tip. The pressure foot 2 is fitted to the front end portion of the main shaft 1 and is formed of resin or metal at the lower end, and an annular bush 4 is fixed. A pair of guide rods 5 are fixed on both sides of the pressure foot 2. The other ends of the guide rods 5 are respectively connected to piston rods of an air cylinder 6 fixed to the housing 3 via flexible joints 7.
[0004]
The pressure foot 2 is urged downward in FIG. 4 by the compressed air supplied to the air cylinder 6, and in the standby state shown in the same figure, the lower end of the bush 4 is 1-2 mm from the tip of the drill 13. It is positioned below.
[0005]
One end of the pipe 8 communicates with the inside of the pressure foot 2, and the other end is connected to a dust collector (not shown).
[0006]
Positioning members 14 and 15 for positioning the printed board W in the horizontal direction are arranged on the surface of the table 9 on which the printed board W as a workpiece is placed.
[0007]
When the drill 13 is positioned in the horizontal direction and the housing 3 is lowered, the lower end of the bush 4 first comes into contact with the surface of the printed board W to press the printed board W against the table 9. In this state, the housing 3 is further lowered, for example, by an incision amount based on the NC command value, and a drill 13 having a predetermined depth is drilled into the printed board W by the drill 13. Chips generated by this processing are discharged to the outside through the pipe 8.
[0008]
[Problems to be solved by the invention]
By the way, according to the above-described conventional example, the positioning members 14 and 15 are arranged so that the respective surfaces thereof are flush with the surface of the table 9, but a step may be generated.
[0009]
FIG. 5 is a front sectional view showing the appearance when the printed circuit board W is pressed by the conventional pressure foot 2 in a state in which a step is generated.
[0010]
As illustrated, for example, when the printed circuit board W is fixed in a state where the surface 14a of the positioning member 14 is higher than the surface 15a of the positioning member 15 and a step is formed between the both surfaces 14a, 15a, the printed circuit board W becomes a bush. 4 is fixed between the front surface 14a and a so-called one-sided state, and a gap is formed between the printed board W and the front surface 15a.
[0011]
When drilling is performed with the drill 13 in such a state, a portion of the printed board W that is not pressed by the pressure foot 2 moves unnecessarily up and down, and the drilling position shifts and the machining accuracy decreases. To do. Moreover, when the printed circuit board W moves up and down, the drill 13 may be broken, and the processing efficiency decreases. Furthermore, scratches may occur on the surface of the printed circuit board W due to contact with each other.
[0012]
Even when the surfaces 14a and 15a of the positioning members 14 and 15 are arranged on the same plane as the surface of the table 9, the printed circuit board W itself may vary in plate thickness due to the manufacturing process. Such piece contact occurs, and as in the case described above, processing accuracy and processing efficiency are reduced, and the printed circuit board W is scratched.
[0013]
Accordingly, an object of the present invention is to provide a printed circuit board processing machine that solves the above-described problems, improves processing accuracy and processing efficiency, and prevents damage to the workpiece surface.
[0014]
[Means for Solving the Problems]
The invention according to claim 1 is provided with a main shaft having a tool attached to a tip end thereof, and a pressure foot movable along the axial direction of the main shaft, and a workpiece placed on a table is moved by the pressure foot. In the printed circuit board processing machine that processes with the tool while pressing against the table, the pressure foot is arranged so as to be movable in the axial direction and has a plurality of cylinder parts, and a base end side of the cylinder part by the cylinder parts. A plurality of piston members that are held so as to be movable in the axial direction and have a pressing portion that can be moved toward and away from the workpiece on the tip side, and each cylinder portion and the back side of each piston member are configured. A plurality of back pressure chambers, a communication channel for communicating the plurality of back pressure chambers, the plurality of back pressure chambers and the communication channel, And a fluid filled in a sealed state, is characterized by.
[0015]
According to a second aspect of the present invention, in the printed circuit board processing machine according to the first aspect, the plurality of cylinder portions are arranged at positions that equally divide the holder in the circumferential direction around the tool. And
[0016]
[Action]
The plurality of piston members can be individually moved in the axial direction by supplying and discharging fluid to the respective back pressure chambers. Therefore, the pressing portion of each piston member can be moved individually in the contact / separation direction (axial direction) with respect to the workpiece. Furthermore, since the plurality of back pressure chambers are communicated with each other through the communication flow path, even when there is a height difference on the surface of the workpiece, each pressing portion does not generate a gap with the workpiece surface. The workpiece surface can be reliably contacted at an appropriate height position corresponding to the height difference, and the workpiece can be pressed with the same applied pressure.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, what attached | subjected the same code | symbol has the same structure or effect | action, The duplication description about these shall be abbreviate | omitted suitably.
[0018]
<Embodiment 1>
1, 2, and 3 show an example of characteristic portions of the printed circuit board processing machine according to the present invention. Among these, FIG. 1 shows a front longitudinal section in the vicinity of the tip of the main spindle of the printed circuit board processing machine, and FIG. 2 is a view of the pressing portion of the pressure foot as viewed from below, and FIG. (B) is an expanded view explaining operation | movement of a pressure foot.
[0019]
The printed circuit board processing machine according to the present invention includes a main shaft 1 and a pressure foot 2 as shown in FIG.
[0020]
The main shaft 1 has an axis C oriented in the up-and-down direction in FIG. 1, and is rotatable about the axis C and can be moved along the axis C in the up-and-down direction in FIG. Further, it is supported by a processing machine main body (not shown). In the present embodiment, a drill 13 as a tool is attached to the tip of the main shaft 1. In addition to this, for example, a reamer or an end mill is also used as the tool. In this embodiment, the tool is mounted on the positioning members 14 and 15 on the table 9 (see FIG. 4) by the drill 13. A case where a drilling process is performed on the printed circuit board W as the placed work will be described as an example.
[0021]
The pressure foot 2 includes a base member (guide member) 10 fitted from below to the tip of the main shaft 1, a holder 20 attached to the base member 10, and a direction along the axis C (hereinafter referred to as the axis 20). And a plurality of piston members 30 held so as to be movable in the “axial direction” as appropriate.
[0022]
Of these, the base member 10 is formed in a cup shape and is supported in the same manner as the conventional example shown in FIG.
[0023]
That is, as shown in FIG. 4, a pair of guide rods 5 are fixed on both sides of the pressure foot 2. The other ends of the guide rods 5 are respectively connected to piston rods of an air cylinder 6 fixed to the housing 3 via flexible joints 7. The pressure foot 2 is urged downward in FIG. 4 by the compressed air supplied to the air cylinder 6.
[0024]
Returning to FIG. The base member 10 configured as described above can be moved in the axial direction (vertical direction in FIG. 1) separately from the main shaft 1. In the center of the bottom of the base member 10, a through hole 11 for attaching a holder 20 described below is formed.
[0025]
The holder 20 is formed in an annular shape as a whole, and a cylinder portion 21 is formed at each position equally dividing the circumferential direction. In the present embodiment, a total of four cylinder portions 21 are formed, one for each position that divides the circumferential direction into four equal parts. Each cylinder portion 21 is formed in a cylindrical shape so that its axis is parallel to the axis C of the main shaft 1 described above, and a small-diameter through hole 22 is drilled in the lower portion on the tip side. . On the other hand, each cylinder part 21 is sealed in the upper part which becomes a base end side, and the adjacent horizontal cross-sectional shape formed in the upper end is communicated by the annular communication channel 23. That is, the four cylinder parts 21 are all connected by this communication flow path. A through hole 24 through which the above-described drill 13 can pass (penetrate) is formed in the center portion of the holder 20 in the vertical direction.
[0026]
The plurality of piston members 30 are respectively held by the cylinder portion 21 of the holder 20 so as to be movable in the axial direction. Each piston member 30 has a piston part 31, a shaft part 32, and a pressing part 33 in order from above.
[0027]
Among these, the piston part 31 is formed in a columnar shape, and is fitted inside the cylinder part 20. An O-ring (seal member) 34 is attached to the intermediate portion of the piston portion 31 in the vertical direction. The O-ring 34 forms a back pressure chamber 35 having oil tightness between the inner surface of each cylinder portion 21 and the back side of the piston portion 31 of each piston member 30. The four back pressure chambers 35 configured in this way are communicated with each other by the communication channel described above.
[0028]
The shaft portion 32 of each piston member 30 is fitted to the small-diameter through-hole 22 of the above-described cylinder portion 20 so as to be movable up and down, and the above-described piston portion 31 is fixed to the upper end on the base end side, A pressing portion 33 described below is fixed to the lower end on the front end side.
[0029]
Each pressing portion 33 is formed in a fan shape as shown in FIG. Each pressing portion 33 is formed in a sector shape with a central angle of 90 degrees, and an arc-shaped cutout portion 33a is formed on the center side. As shown in FIG. 2, the four pressing portions 33 form an annular shape as a whole, and the cutout portions 33 a are combined to form a circular through hole 36. The pressing portions 33 adjacent to each other have guide surfaces 33b and 33b in contact with each other, and the guide surface 33b of one pressing portion 33 moves in the axial direction of the other pressing portion 33 adjacent thereto. (Up and down movement) is guided. Furthermore, the thickness of each pressing portion 33 is such that the mutual guide surfaces 33b and 33b are not separated even when each piston member 30 is moved in the axial direction and disposed at an arbitrary position. Is set. That is, even when the piston member 30 is disposed at the uppermost position (hereinafter referred to as “rising limit”) shown in the left half of FIG. Even in the case of being arranged at the “lower limit”), the guide surfaces 33b and 33b of the adjacent piston member 30 are always in contact with each other so that the other can be guided. In other words, the thickness t of the pressing portion 33 is configured to be thicker than the stroke that is the difference between the ascending limit and the descending limit of the piston member 30.
[0030]
As described above, the four back pressure chambers 35 formed on the upper portions of the four cylinder portions 21 of the holder 20 are communicated with each other by the communication flow path 23. That is, the four back pressure chambers 35 are integrally configured as a whole together with the communication flow path 23 for communicating these. In the present embodiment, the four back pressure chambers 35 and the communication flow path 23 are filled with oil 40 as a fluid in a sealed state. Note that the amount of oil 40 to be filled at this time is, for example, the four back pressure chambers 35 and the communication flow path when all of the four piston members 30 are positioned between the above-described rising limit and falling limit. What is necessary is just to make it the quantity with which 23 is filled. By doing so, a large stroke amount of the four piston members 30 can be secured.
[0031]
In the present embodiment, the tip position of the drill 13 attached to the tip portion of the main shaft 1 is 1 to 3 mm from the position of the bottom surface 33c of the pressing portion 33 when the piston member 30 is located at the ascending limit. It is assumed that it is set so as to be positioned approximately upward.
[0032]
Next, with reference to FIGS. 3A and 3B, the operation of the printed circuit board processing machine having the above-described configuration will be described focusing on the operation of the pressure foot 2. FIG. 3A and 3B are schematic views in which the above-described holder 20 is developed in the circumferential direction. That is, it is a schematic diagram in which the four cylinder portions 21 arranged in a position equally divided into four in the circumferential direction of the holder 20 are actually rearranged linearly. Further, for convenience of explanation, the four piston members 30 are sequentially designated as piston members 30A, 30B, 30C, and 30D from the left side, and the respective pressing portions 33 are referred to as pressing portions 33A, 33B, 33C, and 33D in this order.
[0033]
In the following description, for example, as shown in FIG. 1, since the surface 14 a of the positioning member 14 is higher than the surface 15 a of the positioning member 15, as shown in FIGS. An example in which the surface of the surface is stepped like the surfaces W1, W2, and W3 will be described.
[0034]
When the housing 3 (see FIG. 4) is lowered and the pressing portion 33A of the piston member 30A comes into contact with the surface W1 of the printed circuit board W, the pressing portions 33B, 33C, and 33D of the other piston members 30B, 30C, and 30D are printed. It is assumed that it is not in contact with the substrate W. In this case, the pressing portion 33 </ b> A is pushed upward by the surface W <b> 1 of the printed circuit board W and rises relative to the holder 20. As a result, the oil 40 in the back pressure chamber 35 of the cylinder 21 holding the piston member 30A moves to the other back pressure chamber 35 via the communication channel 23, and as shown in FIG. The piston members 30B, 30C, and 30D are lowered relative to the holder 20.
[0035]
Further, the housing 3 is lowered, and when the pressing part 33B of the piston member 30B comes into contact with the surface W2 of the printed board W in addition to the pressing part 33A of the piston member 30A, the pressing parts 33C and 33D come into contact with the printed board W. Suppose that it was not. In this case, the piston members 30 </ b> A and 30 </ b> B are raised, whereby the hydraulic pressure 40 of these back pressure chambers 35 and 35 moves to the back pressure chambers 35 and 35 of the piston members 30 </ b> C and 30 </ b> D via the communication channel 23. As a result, the piston members 30C and 30D are lowered and the pressing portions 33C and 30D are brought into contact with the surface W3. Thus, finally, the pressing portions 33A, 33B, 33C, and 33D of the piston members 30A, 30B, 30C, and 30D press the surfaces W1, W2, and W3 of the printed circuit board W, respectively.
[0036]
As a result of the pressing portions 33A, 33B, 33C, and 33D pressing the periphery of the processing portion on the printed circuit board W by the drill 13 in an annular shape, the tip of the drill 13 comes into contact with the processing portion of the printed circuit board W and drilling is started. Even so, the printed circuit board W does not move up and down unnecessarily. Therefore, the machining position is not shifted, the machining accuracy is not lowered, and the drill 13 is not broken and the machining efficiency is not lowered due to the replacement.
[0037]
In addition, since the four cylinder portions 21 formed in the holder 20 are communicated by the communication flow path 23, the pressure applied when the pressing portions 33A, 33B, 33C, 33D press the surface of the printed circuit board W is increased. It is possible to solve the conventional problem that the surface of the printed circuit board W is damaged by a pressing portion having a particularly large pressing force.
[0038]
Moreover, in this Embodiment, since the piston part 31 of the piston member 30 fitted to each cylinder part 21 is formed larger diameter than the small diameter through-hole 22 of the cylinder part 21, each piston member 30 does not fall off from the cylinder part 21.
[0039]
In the above-described embodiment, the oil 40 is used as the fluid that fills the back pressure chamber 35 and the communication flow path 23, but water, air, or the like may be used instead.
[0040]
Alternatively, the piston portion 31 and the shaft portion 32 of the piston member 30 may be formed to have the same diameter, and the cylinder portion 21 and the through hole 22 may be formed to have the same diameter.
[0041]
Further, a cylinder portion may be formed directly on the base member 10 of the pressure foot 2, and the piston member may be directly held by the cylinder portion.
[0042]
Moreover, the shape of the press part 33 is not restricted to a fan shape, For example, you may form in disk shape. And the number of cylinder parts 21 and piston members 30 is not limited to four, and may be other numbers as long as it is plural.
[0043]
【The invention's effect】
As described above, according to the present invention, the plurality of piston members can be individually moved in the axial direction by supplying and discharging fluid to the respective back pressure chambers. The parts can individually move in the contact / separation direction (axial direction) with respect to the workpiece. Furthermore, since the plurality of back pressure chambers are communicated with each other through the communication flow path, even when there is a height difference on the surface of the workpiece, each pressing portion does not generate a gap with the workpiece surface. Since the workpiece surface can be reliably contacted at an appropriate height position corresponding to the height difference and the workpiece can be pressed with the same applied pressure to prevent the occurrence of per one piece, the machining accuracy and machining efficiency are improved. Further, it is possible to effectively prevent the work from being damaged.
[Brief description of the drawings]
FIG. 1 is a front sectional view of the vicinity of a spindle tip portion in a printed circuit board processing machine according to the present invention.
FIG. 2 is a view of a pressing portion of a pressure foot of a printed circuit board processing machine according to the present invention as viewed from below.
FIGS. 3A and 3B are operation explanatory views of the printed circuit board processing machine according to the present invention. FIGS.
FIG. 4 is a partially broken front view in the vicinity of a main shaft portion in a conventional printed circuit board processing machine.
FIG. 5 is an operation explanatory diagram of a conventional printed circuit board processing machine.
[Explanation of symbols]
1 Spindle 2 Pressure foot 9 Table 10 Guide member (base member)
13 Tool (Drill)
20 Holder 21 Cylinder portion 23 Communication channel 24 Through hole 30 through which tool can penetrate Piston member 33 Pressing portion 33a Notch portion 35 Back pressure chamber 40 Fluid (oil)
C Spindle axial direction W Workpiece (printed circuit board)

Claims (2)

The tool includes a spindle having a tool attached to the tip, and a pressure foot movable along the axial direction of the spindle, and pressing the workpiece placed on the table against the table by the pressure foot In printed circuit board processing machines that process by
The pressure foot is
A holder having a plurality of cylinder portions arranged so as to be movable in the axial direction;
A plurality of piston members each having a pressing portion that is proximally held by each of the cylinder portions so as to be movable in the axial direction and can be moved toward and away from the workpiece on the distal end side;
A plurality of back pressure chambers configured between each of the cylinder portions and the back side of each of the piston members;
A communication channel for communicating the plurality of back pressure chambers;
A fluid filled in a sealed state in the plurality of back pressure chambers and the communication channel;
A printed circuit board processing machine. The plurality of cylinder portions are arranged at positions that equally divide the holder in the circumferential direction around the tool.
The printed circuit board processing machine according to claim 1.

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