JPH0716849B2 - High speed drilling method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-speed drilling method using a machine tool controlled by a numerical controller.

Conventional technology When making a large number of holes using an NC machine tool, it is common when positioning is completed on the XY plane, when drilling is completed by lowering the Z-axis, and when returning to the positioning plane (retract) is completed by raising the Z-axis. The in-position width of
At the end of each operation, by detecting that the position of the tool has entered the common in-position width, execution of the next block, that is, pulse distribution is performed.

Problems to be Solved by the Invention According to the above-mentioned conventional technique, it is determined that the movement path of the tool has reached the in-position width from the tool start point S to the initial point P1 as shown by the dashed line in FIG. Then, the pulse distribution of the next block is executed to lower the Z axis and start drilling. Next, when it is determined that the tool has reached the bottom of the hole and has entered the in-position width, pulse distribution for the next block is executed to raise the Z-axis to start retract, and the tool returns to the initial point P1 and When it is confirmed that the position width has been entered, the pulse distribution of the next block is executed and the movement to the next initial point is started. As described above, according to the conventional technique, the next movement is executed after confirming the end of the movement of the tool to the command position for each block. Moreover, since the in-position width is the same in all strokes, positioning accuracy is unified to the in-position width of the stroke that requires high accuracy, and as a result, this positioning takes time and the drilling time becomes long. is doing.

Therefore, an object of the present invention is to provide a high-speed drilling method that shortens the positioning time according to the required positioning accuracy and enables high-speed drilling.

Means for Solving Problems A first invention of this application is a hole bottom in-position width for detecting that a tool has reached a commanded hole bottom position during a drilling cycle, and a tool mounting shaft at a commanded hole drilling position. The positioning in-position width for detecting that positioning has been performed and the retracting in-position width for detecting that the tool mounting axis has reached the command position at the time of retracting are respectively provided. At least one of the in-position width is set larger than the above-mentioned hole bottom in-position width, and when identifying the execution block data of each block of the NC program, the data for identifying each block for the positioning block, drilling cycle block and retract block. Is added to the execution format data, and when the pulse distribution based on the execution format data is completed, By determining whether the tool has reached each in-position width based on the data that identifies positioning, drilling, and retract, and by starting the execution of the next block by reaching each in-position width, The above problems were solved.

Further, in the second invention, after the positioning to the position and the pulse distribution of the retract are completed in the first invention, each timer is provided for measuring a set predetermined time, and before the tool reaches the set in-position width, When the timer times out, execution of the next block is started to solve the above problems and enable high-speed drilling.

Operation As shown in FIG. 1, after being positioned at the drilling position, that is, at the initial point P1, the tool axis (the tool axis, that is, the direction of the hole is the Z axis, and the surface of the workpiece W is the XY plane). Machining start point R for moving the workpiece W to start machining
It takes time for the tool axis to reach, and there is nothing to interfere with the tool during this time. Therefore, the tool moves on the XY plane from the initial point P1 until the tool reaches the machining start point R, and the initial point P1 is moved to the X-
This means that it is sufficient to reach the Y coordinate position, and therefore, the in-position width of the positioning to the drilling position (initial point P1) may be large. or,
Similarly at the time of retract as well, at the tool return position during retract (initial point P1 in the example of FIG. 1), a large in-position width is set according to the machining start point R and the tool return position during retract. You can That is, as shown by the solid line in FIG. 1 for the movement trajectory of the tool, the in-position width for positioning to the machining position and positioning at the time of retracting is increased to accelerate the start of the drilling operation (Z-axis movement), and By accelerating the start of the positioning operation from the retract to the next drilling position and taking the tool movement locus as shown by the solid line in FIG. 1, the positioning time is shortened and high-speed drilling is possible. Therefore, the first aspect of the present invention enables high-speed drilling by setting the positioning in-position width at the drilling position and the in-position width at the time of retract to be larger than the in-position width for hole bottom, which requires high positioning accuracy. .

Further, in the second invention, the positioning position of the positioning cycle (position P1 in FIG. 1), the command position during retract (position P1 in the example of FIG. 1) and the machining start position (position R in FIG. 1) Since the work and the tool do not interfere even if the X, Y, and Z axes move during the interval, depending on the distance in the Z axis direction (l in Fig. 1) during this interval, after pulse distribution to the positioning position of the positioning cycle is completed, The drilling cycle start time that the tool and work do not interfere even if the Z axis movement starts,
And after the end of pulse distribution at the time of retract, the tool and the work do not interfere even if the positioning for the next hole machining is started.The positioning start time is set to the timer after the end of each pulse distribution, and when the timer reaches the set time Even if the tool does not reach the in-position width, pulse distribution of the next block (drilling cycle or positioning cycle) is started. This enables high-speed drilling.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. The numerical control device and the machine tool controlled by the numerical control device are the same as the conventional ones, and the configuration thereof is omitted.

In drilling, as shown in FIG. 1, a positioning cycle from the start point S to the initial point P1 at the drilling position, a drilling cycle for drilling a workpiece from the position P1 to the hole bottom P2, and from the hole bottom P2 The tool comprises a retract cycle for returning to the command position (in this embodiment, it is supposed to return to the initial point P1). In this embodiment, the plane of the work W is the XY plane and the hole axis direction is the Z axis.

As shown in FIG. 1, this drilling command is issued from the start point S to the initial point P1, the hole bottom position P2, the initial point P1,
And when continuing to the next drilling position, that is, in FIG.
The locus shown by the dotted chain line is the relative locus of the tool (drill) with respect to the work W, but the work W is between the initial point (or command position during retract) P1 and the machining start position R.
And the tools have nothing to interfere with. Therefore, work W
There is no problem even if the Z axis is driven before the tool reaches the initial point P1 as shown by the solid line in FIG. That is, when the tool reaches the Z coordinate position R with respect to the work W, the XY coordinate position of the tool has only to reach the XY coordinate position of the initial point P1. Therefore, the positioning to the initial point P1 is performed. This means that the in-position width during the cycle and the in-position width during the retract cycle may be larger than the in-position width at the positioning position (hole bottom) in the drilling cycle. The position width is set according to the distance 1 between the initial point P1 (and the command position at the time of retract) and the machining start position R. In this embodiment, the in-position widths of the positioning cycle and the retract cycle are the same.

Further, in the present embodiment, after the end of pulse distribution in the positioning cycle and after the end of pulse distribution in the retract cycle,
Before the detection of reaching the in-position width of the command position of each cycle, when the timer for measuring each of the above predetermined times expires, immediately the processing of the next block, that is, the drilling cycle processing, to the next drilling position The positioning cycle process is performed.

FIG. 2 is an explanatory diagram for obtaining the above-mentioned predetermined time, which is X-
1 is a diagram showing a relationship between a speed command regarding a tool feed on the Y plane and an actual tool movement speed and a relationship between a speed command regarding a tool feed on a Z axis and an actual tool movement speed, with a time axis as a parameter, and a one-dot chain line In the speed command, the solid line shows the actual tool moving speed. When pulse distribution for positioning is started at T0 in Fig. 2, the tool moves on the XY plane at the speed indicated by f1 in the figure by the time constant Tcx of the X-axis and Y-axis servo system, and the rapid feed rate. After reaching Fx and terminating the pulse distribution at T1, the movement continues at the speed indicated by f1 'in the figure, and at T3, the speed becomes 0 and the movement in the XY plane ends. At this time, the tool moves from the start point S on the work W shown in FIG. 1 to the initial point P1 in the XY plane. When the pulse distribution is started at T2 in Fig. 2, the tool moves in the Z-axis direction at the speed indicated by f2 in the drawing by the time constant Tcz of the Z-axis servo system to reach the cutting feed speed Fzc,
After the pulse distribution is completed at 4 o'clock, cutting is continued at the speed indicated by f2 'in the figure, and at T6, the speed becomes 0 and the movement in the Z-axis direction is completed. At this time, the tool moves from the initial point P1 shown in FIG. 1 to the hole bottom position P2 in the Z-axis direction for drilling. Tool movement and Z in the XY plane described above
In the relation of tool movement in the axial direction, the tool is XY
The movement that moves in the plane and in the Z-axis direction is the first
It is shown by ab of the actual tool movement trajectory shown in the figure. Therefore, in order to prevent the tool from interfering with the work W from the start point S to the machining start point R, in comparison with the vertical distance 1 from the upper surface of the work W to the start point S, the tool is X
It is sufficient if the distance S1 of movement in the Z-axis direction is small while moving in the -Y plane.

S1 <l (1) Further, in FIG. 2, the time for the tool to move in the XY plane and in the Z-axis direction is the section from T2 o'clock to T3 o'clock. However, in the vicinity of T3 when the tool movement in the XY plane ends, the tool movement speed in the XY plane is extremely slow, so there is a time zone in which the movement distance can be ignored. On the time axis, if the time when this time zone starts is TS time, the moving distance S0 from TS time to T3 time is XY
Using the tool movement speed f1 'in the plane, Can be obtained by The tool movement speed f1 'in the XY plane is a function of the rapid feed rate Fx in the XY plane, the time constant Tcx of the servo system for the XY plane, and the time t. Is represented as Therefore, with reference to T1 when the panel distribution ends, the time from T1 to the start of the ignorable time zone is T0 ', and the time from T1 to the end of tool movement in the XY plane is T3'. Then, as is apparent from FIG. 2, from the relationship between the equations (2) and (3), Therefore, by defining the negligible movement distance S0, the time T0 ′ from the time T1 when the pulse distribution ends to the time when the negligible time zone starts can be obtained.

Therefore, in FIG. 2, the time during which the tool moves in the XY plane and moves in the Z-axis direction can be regarded as the section from T2 o'clock to TS o'clock. The distance that the tool moves in the Z-axis direction within this time is the distance S1 that moves in the Z-axis direction while moving in the XY plane. Therefore, the tool is X
-Distance S1 to move in the Z-axis direction while moving in the Y plane
Is the tool movement speed f2 in the Z-axis direction, TS time when the tool can be regarded as ending movement in the XY plane, and T2 time when the tool starts movement in the Z-axis direction. Can be obtained by The tool moving speed f2 in the Z-axis direction is a function of the cutting feed speed Fzc, the time constant Tcz of the Z-axis servo system, and the time t. Is displayed as. Therefore, assuming that the time until the tool starts moving in the Z-axis direction is T2 'with reference to the time T1 when the pulse distribution of the servo motor for the XY plane ends, the formula (5) and the formula (6) are given. From the relationship of the formula, Becomes From the formula (1), since S1 <l, The formula is established. In formula (8), cutting feed rate Fz
The time constant Tcz of the c · Z-axis servo system is known, and the time T0 ′ from the time T1 when the pulse distribution of the XY plane servo motor ends to the time when the negligible time starts is expressed by the formula (4) ′. Therefore, if the vertical distance l from the upper surface of the work W to the tool start point S is known, from the time T1 when the pulse distribution of the servo motor for the XY plane ends until the tool starts to move in the Z-axis direction. The waiting time T2 ′ of T can be determined. That is, even if the pulse distribution in the Z-axis direction is executed after the waiting time T2 'which is the smallest value that satisfies the expression (8) after the pulse distribution of the servo motor for the XY plane is completed, the tool is The machining start point R can be reached without interfering with the work W.

Next, when the pulse enters the in-position width of the Z-axis command position of the drilling cycle, "at 5 o'clock, pulse distribution of the next block, that is, the retract cycle is executed to perform the retract operation at the high moving speed FZR.

Further, S2 in FIG. 2 is the distance of the retract operation performed while the tool is moving in the XY plane.
Corresponds to S2. In this case, using the Z-axis high-speed moving speed FZR during retract operation and the time constant Tcz of the Z-axis servo system, as in the case of S1, From the equation, the waiting time T7 from the end of the pulse distribution of the retract operation to the execution of the pulse distribution of the servo motor for the XY plane can be obtained.

Therefore, the vertical distance l from the upper surface of the workpiece W to the start point S, the negligible movement distance S0, and the in-position width of the positioning cycle and the retract cycle (in this embodiment, the position width of the positioning cycle and the retract cycle are the same) are set. When the boring process is started after setting by the manual data input device of the numerical control device, the waiting time T2 ', T7 is automatically calculated by the numerical control device to perform the high-speed drilling process. Since the in-position width for the hole bottom is the same as the conventional one, it is not necessary to set it with the manual data input device.

FIGS. 3 (a) to 3 (c) are information processing flowcharts performed by the numerical movement device according to the present embodiment. When a machining command is input, the microprocessor (hereinafter referred to as CPU) of the numerical control device is FIG. 3A is a task process for creating execution format data for block read pulse distribution, in addition to the conventional execution format data creation processing.
Process. That is, it is determined whether the read block is a drilling cycle, a retract cycle, or a positioning cycle (steps S1 to S3).
The flag F3 is set to "1" for F2, the flag F3 if it is a retract cycle, and the flag F1 is set to "1" if it is not a positioning cycle (steps S6, S5, S4), and it is added to the execution format data of the block. If it is not the drilling cycle, the retract cycle, or the positioning cycle, this flag processing is not performed and the execution format data creation processing ends.

Next, in the execution of the block based on this execution format data, that is, in the task of pulse distribution processing, it is first determined whether or not the block processing flag F4 is reset (step S100), and the flag F4 is reset. If so, the axis movement has ended in the previous distribution cycle, so distribution processing is started (step 101) and the block processing flag F4 is set to "1" to indicate that block processing is in progress (step S102). ). When the block processing flag F4 is not set to "0" in step S100,
Since the processing of the previous block has not been completed in the previous distribution cycle, the process proceeds to step S103.

Next, it is determined whether or not the pulse distribution end signal is input, and it is confirmed whether or not the pulse distribution is completed (step S10
3) If the pulse distribution is not completed, the pulse distribution process is executed (step 104), and it is further determined whether or not the pulse distribution process is completed (step S105), and the pulse distribution process is completed. If it is possible, the processing in this cycle is ended. Thus, steps S100, S103,
Process 104 and S105. When the pulse distribution is ended and the end of the pulse distribution is detected in step S105, it is determined whether either the positioning cycle flag F1 or the retract cycle flag F3 is set (step S10).
6, S107), if neither is set, the processing in this cycle is ended, and if either the positioning cycle flag F1 or the retract cycle flag F3 is set in steps S106 and S107, the next cycle At step S108, the previous period distribution end flag F5 is set to initialize the timer, and the process in this period is ended. Then, in the next distribution cycle, the process proceeds from step S103 to step S109, and it is determined whether or not the pulse distribution that has just been executed relates to the drilling axis based on the axis number included in the execution format data (step S109). ), If it is a drilling axis, it is further determined whether or not the drilling cycle flag F2 is set (step S110), and if it is a drilling cycle, the tool is within the preset hole bottom in-position width. It is determined whether or not the amount obtained by adding the remaining amount of the command pulse and the error amount is smaller than the in-position width (step S111), and if it is within the in-position width,
Since the axis movement has ended, the block processing flag F4 is reset (step 300), the processing in this distribution cycle is ended, and the distribution processing of the next block is started in the next distribution cycle. Also, if it is not within the in-position width,
Since the axis is moving, the block processing flag F4 is not reset and the processing in this distribution cycle is ended.

If the drilling cycle flag F2 is not set in step S110, it is determined whether or not the retract cycle flag F3 is set (step S112). If it is set, the tool is set in advance for retract retract position. It is determined whether or not it is within the width (step S11
3) If the position is within the in-position width, the axis movement has ended, so the block processing flag F4 is set (step S300), and the processing in this distribution cycle ends.

If it is not within the in-position width in step S113, the process proceeds to step S205, it is determined whether or not the previous cycle distribution end flag F5 is set, and the previous cycle distribution end flag is determined.
If F5 is set, the distribution has ended in the previous cycle, so the positioning timer Ti2 is reset and started (step 206), the previous cycle distribution end flag F5 is reset (step 207), and the timer The time for one cycle between distribution cycles is added to the value of Ti2 (step 208). Next, the value of the timer Ti2 is compared with the time T7 'derived from the predetermined formula (9), and the timer Ti2 determines that the set time T7'.
It is determined whether or not (step 209), and if not, the processing of this distribution cycle is ended. Timer Ti2 is time T
If it exceeds 7 ', the block processing flag F4 is reset (step S300), and the next block processing is started in the next cycle.

Further, if the retract cycle flag F3 is not set in step S112, it is not a retract cycle, so the process proceeds to step S116, it is judged whether or not the general in-position width is entered, and if it is not entered, the processing of this cycle is performed. When it is finished and the width is within the in-position width, the flag F4 is reset, and the distribution process of the next block is performed in the next distribution cycle.

If it is not the drilling axis in step S109, step S114
Shift to, determine whether flag F1 is set,
If it is set, then it is determined whether or not it is within the positioning in-position width. If it is, the process proceeds to step S300, and if not, the process proceeds to step S200 and the same processing as steps S205 to S208. (Steps S200 to S20
3). However, this time, the timer is the positioning timer Ti1,
In step S203, it is determined whether or not the positioning timer Ti1 is derived by the equation (8) and exceeds a preset time T2 '. If it does not exceed, the processing of the distribution cycle is ended, and the time is repeated. Repeat the same process. And timer Ti
When the value of 1 exceeds the time T2 ', the block processing flag F4 is reset (step S300), and the distribution processing of the next block is started in the next distribution cycle.

Therefore, a series of operations from positioning to a drilling cycle and a retract cycle will be described in order. When the distribution process of the previous block is completed and the distribution process of the positioning block for drilling is started, steps S100, S101, S102, S103, S1 are performed.
04, S105, if the distribution is not finished, the process of this distribution cycle is finished, and in the next distribution cycle, steps S100, S103,
When the process of S104 and S105 is repeated and the distribution is completed in a certain distribution cycle (step S105), the flag F1 indicating the positioning cycle is set to "1" in the execution format data of the positioning cycle (step S4). , Step
The process moves from S106 to S108, sets the flag F5, and in the next distribution cycle, moves to steps S100, S103, S109, and step S1.
In 09, it becomes NO during the positioning cycle.
In step S114, it is determined whether or not the flag F1 is set to "1". In this case, since the flag F1 is set to "1", it is determined whether or not the tool has entered the in-position width ( If there is no tool in the in-position width, it is determined whether or not the previous cycle distribution end flag F5 is set (step S200), and if the previous cycle distribution end flag F5 is set, the previous cycle distribution end flag F5 is set. Since the distribution has been completed in a cycle, the positioning timer Ti1 is reset and started (step 201), and the previous cycle distribution end flag F
5 is reset (step 202), and the time for one cycle between the distribution cycles is added to the value of Ti1 of the timer (step 203).
Next, the value of the timer Ti1 is compared with the time T2 'derived from the predetermined formula (8), and it is judged whether or not the timer Ti1 exceeds the set time T2' (step 204). If it does not exceed, the processing of this distribution cycle is ended. From the next distribution cycle, steps S100, S103, S109, S114, S115, S200, S2
If 03, S204 are repeated and the tool enters the in-position width in step S115, or if the timer Ti1 exceeds the time T2 'in step S204, the block processing flag F4 is reset (step 300), and the next cycle Then, the next block process is started.

Since the next distribution cycle is a drilling cycle, pulse distribution of this cycle is started. That is, since the flag F4 is reset and is "0", the steps S100 to S1
The process moves to 01, and the processes of steps S102, S103, S104, and S105 are performed for each distribution cycle. As a result, as shown in FIGS. 1 and 2, the tool moves in the X, Y, and Z axes relative to the work W, resulting in a tool locus as shown by the solid line in FIG. On the other hand, when the distribution processing of the drilling cycle is completed during the drilling cycle (step S105), the flags F1 and F3 are not set to "1", the flag F5 is not set, and the processing of this cycle is finished, and the next In the distribution cycle, steps S100 and S103
To step S109, S110. Since the flag F2 is set as "1" in the execution format data of the drilling cycle, the process proceeds to step S111, and it is judged whether or not the hole bottom in-position width is entered. Steps S100, S103, S109, S110, every distribution cycle until the bottom in-position width is reached.
When the processing of S111 is repeated to enter the hole bottom in-position width, the block processing flag F4 is reset (step
S300).

As a result, in the next distribution cycle, the next block, that is, the pulse distribution of the retract cycle is started, and the same processing as described above is performed, but when the pulse distribution of this retract cycle ends (step S105), the execution format data of the block Since the flag F3 has been set to "1", the flow shifts from step S107 to step S108 to set the flag F5. Then, in the next distribution cycle, steps S100, S103, S1
09, S110, S112, S113, S205, S206, S207, S208, S209 are performed, and in the next cycle, similarly, in steps S100, S103, S10
The processing of 9, S110, S112, S113, S205, S208, S209 is performed. Then, during this processing, in step S113 or step S209, if the in-position width is entered or the retract timer Ti2 exceeds the set time T7, the flag F4 during block execution is executed.
Is reset and the processing of the next block, that is, the positioning block for the next drilling process is started. As a result, the Z-axis moves in response to the retract command, and the Y-axis also moves in response to the move command to the next machining position, and the tool moves relative to the work W as shown by the solid line in FIG. Will be done.

In the above embodiment, the in-position widths for positioning and retract were set, but they may be set to be the same.

In addition, the time T2 ′ from the end of positioning distribution to the start of the drilling cycle and the time T7 from the end of retract distribution to the start of the next positioning cycle are to move the machine.
By modifying 2 ', T7 and setting a more optimal time, the processing speed can be further increased.

EFFECTS OF THE INVENTION According to the high-speed drilling method of the present invention, the next pulse distribution can be executed without waiting for the end of the tool movement in each axis direction, so that the waiting time for starting the pulse distribution can be shortened. , The drilling work can be speeded up.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the movement trajectory of a high speed drilling tool of the present invention, and FIG. 2 is a diagram for explaining the relationship between the pulse distribution and the tool moving speed of the high speed drilling method of the present invention. (a)-(c) is a process flowchart of the Example of the high speed drilling system of the same invention. T2: Drilling start standby time, T7: Positioning start standby time, S: Tool start point, P1 ... Initial point, R ...
… Machining start point, P2… Hole bottom position, W… Work.

Claims (5)

[Claims] 1. A drilling method for drilling a large number of holes in a workpiece using a machine tool controlled by a numerical controller,
Hole bottom in-position width that detects when the tool has reached the commanded hole bottom position during the drilling cycle, positioning in-position width that detects that the tool mounting axis is positioned at the commanded hole drilling position, and tool mounting axis The retract in-position width that detects when the retracted command position has been reached is provided, and at least one of the positioning in-position width and retract in-position width is set larger than the hole-bottom in-position width. When creating the execution format data for each block of the NC program, the data for identifying each block is added to the execution format data for the positioning block, drilling cycle block, and retract block, and pulse distribution based on the execution format data is completed. Sometimes based on the data identifying the above positioning, drilling and retract Fast drilling method have been tool to determine reaches the applicable in-position width, and by reaching the respective in-position width to begin execution of the next block. 2. The high speed drilling method according to claim 1, wherein the positioning in-position width and the retract in-position width are set to be the same width. 3. A hole bottom in-position for detecting that a tool has reached a commanded hole bottom position during a hole making cycle in a hole making method for making a large number of holes in a work using a machine tool controlled by a numerical controller. The width, the positioning in-position width that detects that the tool mounting axis has been positioned at the command drilling position, and the retract in-position width that detects that the tool mounting axis has reached the command value at the time of retract to return. The above-mentioned positioning in-position width,
At least one of the retract in-position width is set larger than the hole bottom in-position width, and each block is identified to the positioning block, drilling cycle block, and retract block when creating the execution format data of each block of the NC program. Data is added to the execution format data, and at the end of pulse distribution based on the execution format data, it is determined whether or not the tool has reached each in-position width based on the data that identifies the positioning, drilling, and retract, and the positioning is performed. And a high-speed drilling method in which a timer for counting a predetermined time after completion of the pulse distribution of the retract is provided, and when the above timer expires before the tool reaches the in-position width, execution of the next block is started. 4. The set time of each timer is set according to a distance between a positioning position or a command position during retract and a machining start position on a work, a servo system time constant, and a moving speed during positioning and retract. Claims Claimed 3rd
High-speed drilling method described in section. 5. The high-speed drilling method according to claim 4, wherein the set time of each timer is determined by making an experiment and correcting it based on the movement of the machine.