JP4136784B2 - Processing method and processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention detects a current position of a controlled object every time a predetermined time elapses, and uses a speed obtained by multiplying a deviation between the command position and the current position by a coefficient as a command speed to reciprocate the controlled object in a uniaxial direction. And a processing apparatus.
[0002]
[Prior art]
FIG. 4 is a front view of a conventional printed circuit board processing machine, and FIG. 5 is a plan view.
[0003]
In FIG. 4, the table 2 of the printed circuit board processing machine 1 is movable on the base 3 in the front-rear (X-axis) direction perpendicular to the paper surface. The cross guide 4 is movable on the column 5 fixed to the base 3 in the left-right (Y-axis) direction in the figure. A spindle 7 that rotatably supports the drill 6 is movable on the cross guide 4 in the vertical (Z-axis) direction in the figure. The illustrated printed circuit board processing machine 1 includes six spindles 7. The printed circuit board 8 is placed on the table 2.
[0004]
Then, by moving the table 2 and the cross guide 4 respectively, the axis of the drill 6 is positioned at the processing position, and the drill 6 is lowered to process a hole in the printed circuit board 8. When the drill 6 is moved to the next processing position, the so-called air cut time is shortened by positioning the drill 6 at the standby position (the tip is about 2 mm above the surface of the printed circuit board 8). Yes.
[0005]
FIG. 6 is a control block diagram of the conventional spindle 7 (that is, the drill 6), in which the drill 6 is driven by position feedback control.
[0006]
In the figure, the input side of the subtracter 20 outputs a coordinate of a target position (hereinafter referred to as “target value”) and outputs a command unit (not shown) and a position detector 25 of the spindle 7 (not shown). The output side is connected to the output side, and the output side is connected to the input side of the multiplier 21. The output side of the multiplier 21 is connected to the input side of the amplifier 22. The output side of the amplifier 22 is connected to the motor 23. The controlled object 24 is connected to the motor 23.
[0007]
Then, a deviation j between the commanded target value p and the output g of the position detector 25, that is, the current coordinate is obtained, and the deviation j is multiplied by a coefficient (position loop gain) k to obtain a command speed vp. Then, the motor 23 is driven. As a result, the control object 24 moves at a speed according to the deviation j.
[0008]
If the movement of the drill 6 is controlled using the position feedback control, the position of the tip of the drill 6 can be accurately positioned. Therefore, for example, when processing a through hole in the printed circuit board 8, the depth of the hole to be processed is minimized. Can be length.
[0009]
However, as is well known, in position feedback control, the moving speed decreases in the vicinity of the target value, so there is a limit to shortening the machining time, and the machining efficiency cannot be improved.
[0010]
By the way, when drilling a printed circuit board 8, there are many through holes, and many holes are processed with a single drill 6. That is, the moving stroke in which the drill 6 moves hardly changes, and the deviation between the response position of the drill 6 when the tip reaches the machining depth and the target value at that time (the deviation at this time is called j0). Are almost the same.
[0011]
Therefore, in the printed circuit board processing machine 1, the position obtained by adding the deviation j0 to the designed processing depth is set as the processing depth on the program, and the target value matches the processing depth on the program regardless of the current coordinates of the drill 6. Immediately, the drill 6 is pulled out from the printed circuit board 8.
[0012]
FIG. 7 is a diagram showing the relationship between the target value p and the response position g when such position feedback control is performed. The dotted line indicates a large value of the coefficient k, and the alternate long and short dashed line indicates a small value of the coefficient k. It is. As is clear from the figure, when the value of the coefficient k is large, the tracking efficiency of the response position g with respect to the target value p is superior to that when the coefficient k is small, so that the machining efficiency can be improved and the reliability of the machining accuracy is improved. Can be improved. Therefore, conventionally, the coefficient k is set to a large value.
[0013]
[Problems to be solved by the invention]
In recent years, the mounting density of electronic components has increased, and accordingly, the interval between holes to be processed is reduced, and the time for the drill 6 to remain in the standby position is shortened.
[0014]
FIG. 8 is a diagram showing the vibration of the table 2 accompanying the movement of the conventional drill 6.
[0015]
As shown in FIG. 5, when the direction of the target value p changes, that is, when the drill 6 is returned from the machining end to the standby position, and when the drill 6 starts machining from the standby position, the arrow M in FIG. As shown, since a rotational motion is generated in the base 1, the table 2 vibrates with respect to the command position (machining position).
[0016]
Here, if the value of the coefficient k is increased (the moving speed is increased), the acceleration increases, and therefore the vibration generated in the table 2 increases.
[0017]
When the vibration of the table 2 generated when the drill 6 is moved from the standby position is not attenuated, the position of the tip of the drill 6 with respect to the printed circuit board 8 is changed, so that it is difficult to maintain the processing accuracy.
[0018]
An object of the present invention is to provide a processing method and a processing apparatus capable of improving the processing accuracy without substantially reducing the processing speed.
[0019]
[Means for Solving the Problems]
To solve the above problems, first means of the present invention, whenever the elapsed time set in advance, and detects the position of the drill at that time as a response position, the deviation between the command position and the latest response position In the machining method in which the drill is reciprocated in one axis direction by the command speed by multiplying the coefficient, the coefficient is a first coefficient used when the drill is moved in a predetermined direction, and the above. A second coefficient having a value smaller than the first coefficient used when moving in the direction of, the first coefficient when moving the drill in a predetermined direction, and the second coefficient in other cases. the second factor to calculate the command speed, the moving direction of the drill of applying the second coefficient includes the standby position of the drill direction, and the movement range get out of the processing target And wherein the door.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiments.
[0022]
FIG. 1 is a control block diagram of a drill 6 according to the present invention, and those having the same or the same functions as those in FIG.
[0023]
In the figure, a determiner 30 is connected in parallel with the subtracter 20 and controls a switch 31. The terminal c of the switch 31 is connected to the output side of the subtracter 20, the terminal a is connected to the input side of the multiplier 21, and the terminal b is connected to the input side of the multiplier 32. The value of the coefficient k1 of the multiplier 21 is larger than the value of the coefficient k2 of the multiplier 32. The output sides of the multiplier 21 and the multiplier 32 are respectively connected to the input side of the amplifier 22. Note that the processing position of the Z coordinate is 0 and the upper side is the + side.
[0024]
Next, the operation of the present invention will be described.
[0025]
FIG. 2 is a flowchart showing the operation of the determiner 30. The determiner 30 stores the value of the commanded target value p for each predetermined period, compares the current target value pn with the previous target value pn-1 (step S10), and (pn− If the value of pn-1) is positive or 0, the process of step S20 is performed, and otherwise, the process of step S30 is performed.
[0026]
In step S20, since the direction of the target value pn is the direction in which the drill 6 is lowered, the terminal c and the terminal a are connected. On the other hand, in step S30, since the direction of the target value pn is the direction in which the drill 6 is raised, the terminal c and the terminal b are connected.
[0027]
FIG. 3 is a diagram showing an actual position with respect to the command position of the table 2 accompanying the movement of the drill 6 in the present invention.
[0028]
As shown in the figure, since the change in the acceleration when the drill 6 changes its direction at the standby position can be reduced, the vibration of the table 2 generated when the drill 6 changes its direction at the standby position causes the drill 6 to vibrate. Since the tip of the wire is attenuated until it reaches the surface of the printed circuit board, the position accuracy of the hole can be improved. Further, since the value of the coefficient k when lowering the drill is increased , the depth accuracy of the hole can be improved.
[0029]
Note that vibration occurs in the table 2 when the drill changes its direction at the descending end (pn), but this does not cause a problem because the machining is completed. Further, as a result of reducing the coefficient k when raising the drill 6, the follow-up accuracy with respect to the target value is lowered, but since the lowered accuracy is about several μm, it becomes a practical problem (that is, the tip of the drill 6 is It does not interfere with the surface of the printed circuit board 8).
[0030]
【The invention's effect】
As described above, according to the present invention, the change in acceleration when the drill changes its direction at the standby position is reduced, and the vibration of the table caused by the change of direction of the drill at the standby position is Since it attenuates before reaching the surface of the printed circuit board, the hole position accuracy can be improved. Further, since the value of the coefficient k when lowering the drill is increased, the depth accuracy of the hole can be improved.
[Brief description of the drawings]
FIG. 1 is a control block diagram of a drill 6 according to the present invention.
FIG. 2 is a flowchart showing the operation of the determiner 30;
FIG. 3 is a diagram showing vibration of the table 2 accompanying the movement of the drill 6 in the present invention.
FIG. 4 is a front view of a conventional printed circuit board processing machine.
FIG. 5 is a plan view of a conventional printed circuit board processing machine.
6 is a control block diagram of a conventional drill 6. FIG.
FIG. 7 is a diagram showing a relationship between a target value p and a response position g.
FIG. 8 is a diagram showing vibration of the table 2 that accompanies the movement of the conventional drill 6;
[Explanation of symbols]
21 Multiplier 24 Control object 30 Judgment device 31 Switching device 32 Multiplier

Claims (1)

Every time a preset time has elapsed, and detects the position of the drill at that time as a response position, and the command speed is multiplied by the coefficient on the deviation between the command position and the latest response position, uniaxial drill This command speed In the processing method of reciprocating in the direction,
The coefficient includes a first coefficient used when the drill is moved in a predetermined direction and a second coefficient having a value smaller than the first coefficient used when the drill is moved in a direction other than the above. ,
When the drill is moved in a predetermined direction, the command speed is calculated by the first coefficient, and in the other case, the second coefficient is calculated .
The processing method according to claim 1, wherein the moving direction of the drill to which the second coefficient is applied exits from the processing target, and the standby position of the drill is included in the moving range .

Images